JP4269277B2 - Test method and test apparatus for heat-resistant tubular member - Google Patents

Description

  The present invention relates to a test method and a test apparatus for a heat-resistant tubular member, particularly a heat-resistant tubular member suitable for evaluating and testing the heat resistance, durability and the like of an exhaust system device used in an internal combustion engine of an automobile.

  Conventionally, when developing a new engine for an internal combustion engine of an automobile, exhaust system equipment used for the development is also evaluated. For example, heat resistance such as an exhaust manifold, a turbine housing, a catalyst case, an exhaust pipe, and a muffler. Evaluation tests such as oxidation resistance, heat crack resistance, and heat deformation resistance, which are indicators of heat resistance and durability of the tubular member, have been performed by attaching to a completed engine. Therefore, the evaluation test of the heat-resistant tubular member can be performed only after the engine is completed, and the development period of the engine tends to be significantly prolonged.

  Therefore, the present applicants, without waiting for the completion of the engine, only for the heat-resistant tubular member, so that the heat-resistant tubular member is exposed to the exhaust gas in substantially the same state as when attached to the actual engine, By adjusting the temperature and pressure of the combustion gas coming out of the combustion chamber, we have developed a test device that can evaluate the heat cracking resistance and heat distortion resistance, which are indicators of heat resistance and heat insulation of the heat resistant tubular member. The test apparatus includes a combustion chamber connected to a tubular portion of a heat-resistant tubular member having at least one tubular portion, a chamber communicating with the upstream side of the combustion chamber, a burner inserted into the chamber, This is a test apparatus for a heat-resistant tubular member having an air passage and a fuel supply passage connected to a burner, and an exhaust pressure-increasing air passage opening in the inner wall of the chamber (see, for example, Patent Document 1).

Japanese Patent No. 2533885

  Generally, in actual engines, the components and temperature of exhaust gas exhausted differ depending on the type of engine such as diesel engine or gasoline engine, and these differences are significant in the heat resistance, durability, heat insulation, etc. of heat resistant tubular members. It has an influence.

  For example, in a diesel engine, air is sucked into a cylinder, and when the piston reaches top dead center, the air is compressed to 1 / 15-1 / 23 of the original volume to 500-700 ° C. Light oil is sprayed in the form of a mist to self-ignite and explode to obtain motive power, but the exhaust gas that is not combusted remains in the exhaust gas, and the exhaust gas has an oxygen content. Becomes an oxidizing gas having a volume ratio of 5% or more. For this reason, in the heat-resistant tubular member used for a diesel engine, the inner wall that becomes the passage of the exhaust gas is exposed to an oxidizing atmosphere by a high-temperature oxidizing gas, so that the inner wall is easily oxidized.

  FIG. 10 is a schematic cross-sectional view from the formation of an oxide film on the tubular portion 11 of the heat-resistant tubular member to the occurrence of a through crack. In FIG. 10, when the atmosphere A in the tubular portion 11 is an oxidizing atmosphere, (a) an oxide film 12 is formed on the surface 11 a (inner wall surface) of the tubular portion 11, and (b) a crack is formed in the oxide film 12. 13 is generated, (c) the crack 13 propagates from the surface 11a into the material of the tubular portion 11, (d) the crack 13 grows further, and the back surface 11b of the tubular portion 11 (surface in contact with the outside air) It becomes a through crack 14 that reaches the point, and the function as a heat-resistant tubular member is impaired due to leakage of exhaust gas or the like.

  As described above, in the heat-resistant tubular member used for the diesel engine, the oxide film formed on the inner wall surface (corresponding to the surface 11a in FIG. 10) on the inner wall serving as the exhaust gas passage is caused by the oxidizing atmosphere. A crack is generated and this progresses and tends to be a through crack from the inner wall to the back surface (corresponding to the back surface 11b in FIG. 10). The oxidation of the inner wall has a great influence on the oxidation resistance, heat cracking resistance and the like, which are indicators of the heat resistance and durability of the heat resistant tubular member.

  On the other hand, in a gasoline engine, the air sucked into a cylinder and gasoline are mixed, compressed, and sparked from a spark plug to explode to obtain power. In a gasoline engine, gasoline is almost completely combusted at the time of explosion, so there is little or very little oxygen remaining in the exhaust gas discharged, and the exhaust gas becomes a non-oxidizing gas. For this reason, in the heat-resistant tubular member used in a gasoline engine, the inner wall serving as an exhaust gas passage is exposed to a non-oxidizing atmosphere, so that the influence of the oxidation of the inner wall on the crack is minimal.

  Rather, gasoline engines are increasingly demanded for lower fuel consumption and lower exhaust gas due to the recent increase in environmental problems, and the development of engines with exhaust gas temperatures exceeding 1000 ° C. is progressing accordingly. It is empirically known that heat-resistant materials generally exhibit a rapid oxidation tendency when exposed to temperatures exceeding about 1000 ° C. For this reason, in a heat-resistant tubular member for a gasoline engine, when the heat-resistant tubular member is heated by being exposed to a high-temperature exhaust gas from about 1000 ° C. or higher, not on its inner wall but on the surface exposed to the outside air. It has been regarded as a problem that oxidation is caused by oxygen components in the air, and cracks are generated in the oxide film generated by the oxidation, and the cracks propagate to cracks.

  The mechanism from the formation of an oxide film to a through crack in a heat resistant tubular member for a gasoline engine is as follows. In FIG. 10 described above, the surface 11a is the surface in contact with the outside air of the tubular portion 11, and the back surface 11b is the surface of the inner wall of the tubular portion 11. In other words, it is similar to the mechanism of a diesel engine, except that the starting point of oxidation and crack is different between the front and back sides. As described above, in the heat resistant tubular member used in the gasoline engine, the oxidation from the surface exposed to the outside air in the heated state exposed to the exhaust gas of about 1000 ° C. or higher is heated. It has a great influence on oxidation resistance, heat cracking resistance and the like, which are indicators of heat resistance and durability.

  In the evaluation test of the heat-resistant tubular member, an evaluation considering the influence on the heat resistance, durability, heat insulating property, etc. of the heat-resistant tubular member due to the difference in exhaust gas component, temperature, etc. depending on the type of engine such as the diesel engine and gasoline engine described above. A test is required. In an on-board durability evaluation test (commonly called an engine dynamo test or an engine bench test) using a completed actual engine, which is one of evaluation tests for heat-resistant tubular members, an actual internal combustion engine is used by using the actual engine. Since the evaluation test that directly reproduces the combustion of the engine can be performed, the influence of the type of engine on the evaluation test result is small. However, in the engine dynamo test, as described above, it is necessary to wait for the completion of the engine, and it is impossible to solve the prolonged development period of the engine.

  On the other hand, although the heat resistance tubular member testing apparatus disclosed in Patent Document 1 can evaluate its heat resistance and heat insulation properties without waiting for completion of the engine, the following is different for each engine type when compared with an actual engine. There was a problem like this.

1) Problems in Evaluation Test of Heat-Resistant Tubular Member for Diesel Engine In the test apparatus disclosed in Patent Document 1, an opening is made in the inner wall of the chamber in addition to the primary air passage for supplying fuel combustion air. The increased pressure air is supplied from the exhaust pressure increasing air passage. For this reason, in the combustion gas (equivalent to exhaust gas in an actual engine), in addition to oxygen consumed for combustion, excess oxygen components in the air are supplied, and the oxidizing combustion gas causes the heat-resistant tubular member to Since the atmosphere in the tubular portion (hereinafter referred to as a test atmosphere) is an oxidizing atmosphere, it is considered appropriate at first glance as an evaluation test of a heat-resistant tubular member for a diesel engine. However, in this test apparatus, the pressure of the combustion gas is adjusted to correspond to the actual engine exhaust pressure so that the temperature of the heat-resistant tubular member becomes equal to the actual temperature by adjusting the air flow in the exhaust pressure-increasing air passage. Thus, the pressure-increased air is merely supplied from the exhaust pressure-increasing air passage for the purpose of evaluating and testing the pressure and temperature in a state substantially equal to the exhaust gas of the actual engine. For this reason, although oxidizing combustion gas is generated, the oxygen content in the test atmosphere cannot be controlled, and the oxygen content in the test atmosphere is not stable because the flow rate of the pressurized air varies depending on the combustion conditions. For example, there was a problem that the evaluation test conditions in an actual diesel engine could not be reproduced for the test atmosphere.

  In recent years, environmental regulations for diesel engines have become stricter, and the development of engines to achieve high output and low fuel consumption with lean fuel has been promoted. As a result, the exhaust gas has increased its temperature and oxygen content. As a result, the gas is more oxidizable and more oxidizable, and the influence of oxidation on the heat-resistant tubular member is increasing. For this reason, the case where the evaluation test result in an actual diesel engine differs from the evaluation test result in the test apparatus disclosed in Patent Document 1 is increasing.

2) Problems in evaluation test of heat-resistant tubular member for gasoline engine As described above, in an actual gasoline engine, the inner wall of the heat-resistant tubular member serving as an exhaust gas passage is exposed to a non-oxidizing atmosphere. The effect of oxidation on the crack is minor. This is because, when comparing the evaluation test result with an actual gasoline engine and the evaluation test result with the test apparatus disclosed in Patent Document 1, the cracks appear to be in the same position although the positions of the generated cracks are in good agreement. In contrast, it was also confirmed from the fact that the degree of occurrence of cracks appears larger (bad) in the test apparatus of Patent Document 1. In particular, the difference between the two was prominent in the test results under conditions where the exhaust gas was heated from around 1000 ° C. to a higher temperature. This is because the exhaust gas is non-oxidizing in an actual gasoline engine, whereas in the test device, the pressure and temperature of the combustion gas are set to be almost equal to the exhaust gas of the actual engine in order to remove excess air. Since the fuel gas is delivered, the combustion gas becomes oxidizable due to the residual unburned oxygen component. Due to the difference in the gas components emitted from the two, the test device is more severe and harsh than the actual gasoline engine. It was thought that the test result was produced.

  As described above, the test apparatus disclosed in Patent Document 1 is an invention whose main purpose is to evaluate and test the pressure and temperature of the combustion gas as being substantially equal to the exhaust gas of the actual engine. However, if the exhaust gas components differ depending on the type of engine, such as diesel engine or gasoline engine, and the exhaust gas temperature becomes high, the influence of the test atmosphere There has been a problem in the reproducibility of cracks in heat-resistant tubular members, and as it is, as a test for evaluating the heat resistance and durability of heat-resistant tubular members, an appropriate result equivalent to an evaluation test in an actual engine is obtained. It was becoming difficult.

  The present invention has been made in view of the above problems, and accurately evaluates heat resistance, durability, etc. of a heat-resistant tubular member used in a diesel engine or a gasoline engine regardless of the type of the engine without waiting for completion of the engine. It is to obtain a test method and a test apparatus that can be tested.

  The inventors of the present invention describe differences in exhaust gas components and temperatures depending on the type of engine such as actual diesel engines and gasoline engines, as well as oxidation resistance and heat cracking, which are indicators of heat resistance and durability of heat resistant tubular members. The research on the relationship with properties such as heat resistance and heat distortion resistance. As a result, in order to reproduce the evaluation test results in various actual engines with the heat resistant tubular member testing apparatus disclosed in Patent Document 1, the atmosphere in which the heat resistant tubular member is exposed in the actual engine is the test atmosphere of the test apparatus. In order to achieve this, it is necessary to set the oxygen content in the test atmosphere to any desired content corresponding to various engines, and to maintain it stably. In addition to the necessary air, the inventors have obtained the knowledge that excess air, oxygen gas, and inert gas may be directly mixed into the combustion gas, and have arrived at the present invention.

That is, the test method for a heat-resistant tubular member of the present invention is a test method for heating the heat-resistant tubular member by flowing a high-temperature combustion gas by burning fuel with oxygen in the tubular portion of the heat-resistant tubular member. At least one combustion chamber connected to the tubular portion of the tubular member, a chamber portion communicating with the upstream side of the combustion chamber, a burner inserted into the chamber portion, a fuel supply path and combustion air connected to the burner A supply path, a gas supply path connected to the chamber, an excess air supply path provided with a flow rate adjusting means connected to the gas supply path, and further connected to at least one of the gas supply path or the chamber Using a test apparatus having at least one of an oxygen gas supply path and an inert gas supply path provided with a flow rate adjusting means, the pipe is fed from the fuel supply path in a state where the tubular portion is connected to the combustion chamber. The fuel Burned with air fed from burnt air supply passage, is introduced and the resulting combustion gases into the combustion chamber, at least than one said combustion chamber of the gas supply channel or the chamber, at least oxygen gas, Any one or more of inert gases are fed, and at that time , the excess air and the oxygen gas so that the atmosphere (test atmosphere) in the tubular portion of the heat-resistant tubular member becomes an atmosphere exposed to the actual exhaust gas. The gas flow rate of any one or more of the inert gases is adjusted by the flow rate adjusting means.

Examples of the heat-resistant tubular member targeted by the present invention include an exhaust manifold, a turbine housing, a catalyst case, an exhaust pipe, a muffler, a turbine housing integrated exhaust manifold, a catalyst case integrated exhaust manifold, and the like, and at least one tubular in which exhaust gas flows Part. In this tubular part, a fuel is burned with oxygen, and it flows as high temperature combustion gas, and heat-resistant tubular member is heated. Furthermore, in addition to the oxygen required for fuel combustion, at least one of oxygen gas and inert gas is fed at a regulated flow rate , so that the oxygen content in the test atmosphere can be supplied to various engines. This can be stably maintained by setting the corresponding desired value (content). As a result, the test atmosphere in the tubular portion of the heat-resistant tubular member can be freely controlled from an oxidizing atmosphere to a non-oxidizing atmosphere, and is in a state equal to the atmosphere exposed to the actual exhaust gas. It is possible to accurately evaluate and test the heat resistance and durability of the member. Excess air and oxygen gas make the test atmosphere oxidizing and make it almost equal to the exhaust gas atmosphere of the actual engine (especially diesel engine), and inert gas non-oxidize the test atmosphere. In order to make the exhaust gas of an actual engine (especially a gasoline engine) almost equal to the exhaust gas, it is fed. The excess air supply path, the oxygen gas supply path, and the inert gas supply path provided with the flow rate adjusting means in the present invention are the supply paths other than the supply path in which the flow rate adjusting means is arranged on each gas supply path. It includes a supply path provided with a flow rate adjusting means at each gas supply source serving as a starting point of the path, or a supply path provided with a flow rate adjusting means for directly adjusting a gas supply amount to the supply source.

  In the test method for a heat-resistant tubular member of the present invention, in addition to air necessary for combustion, at least one of excess air, oxygen gas, and inert gas is fed into the combustion chamber, and the combustion gas It is preferable to increase the pressure at or above atmospheric pressure. By increasing the pressure of the combustion gas, the fuel can be burned stably, it is possible to correspond to the actual exhaust pressure of the engine, and the temperature of the heat-resistant tubular member is adjusted to be equal to the actual temperature it can. As a result, in addition to the atmosphere, an evaluation test can be performed in a state where the pressure and temperature are substantially equal to the actual engine exhaust gas. It is desirable that the pressure of the combustion gas be increased to a pressure 1.1 times or higher than the atmospheric pressure.

  In the test method for a heat-resistant tubular member of the present invention, the oxygen sensor disposed in the tubular portion of the heat-resistant tubular member, a control unit, the excess air supply path, the oxygen gas supply path, and the inert gas supply A flow rate adjusting means disposed in any one or more of the paths, and a detection signal of the oxygen content measured by the oxygen sensor is input to the control unit, and the target oxygen content is measured by the control unit. Comparing the oxygen content and calculating the adjustment amount of the flow rate adjustment means necessary to correct the excess or deficiency of the oxygen content, outputting a control signal of the adjustment amount to the flow rate adjustment means, the flow rate adjustment means It is preferable that the oxygen content in the atmosphere (test atmosphere) in the tubular portion of the heat-resistant tubular member is adjusted so as to be a predetermined volume ratio by operating. According to the test method in the above configuration, the flow rate adjusting means can be adjusted based on the measurement result of the oxygen content in the tubular portion of the heat-resistant tubular member to adjust the supply amount of excess air, oxygen gas, and inert gas. Therefore, feedback control of the oxygen content in the test atmosphere is possible, and the oxygen content can be maintained more accurately and stably so that the oxygen content becomes a predetermined capacity ratio. At the same time, the pressure of the combustion gas can be controlled by adjusting the supply amount of excess air, oxygen gas, and inert gas.

  Furthermore, in the heat resistant tubular member testing method of the present invention, the oxygen content in the atmosphere (test atmosphere) in the tubular portion of the heat resistant tubular member is set to an arbitrary value of 0.01% or more and less than 21% by volume ratio. It is good. By setting the oxygen content in the test atmosphere to a desired value of 0.01% or more and less than 21% by volume ratio, exhaust gas components that are compatible with most engines, regardless of diesel engine or gasoline engine Can be reproduced. For example, in a diesel engine, the oxygen content in the exhaust gas is an oxidizing gas having a volume ratio of 5% or more. Therefore, in the test method of the present invention, the oxygen content in the test atmosphere is determined by the volume ratio. 5% or more, preferably 10% or more, more preferably 10% or more and less than 21%, and even more preferably 10% or more and 19% or less, and heat resistance as an oxidizing atmosphere equivalent to the exhaust gas of an actual diesel engine Tubular members can be evaluated. On the other hand, when reproducing a gasoline engine, the oxygen content in the test atmosphere is set to less than 5%, desirably 3% or less, more desirably 1% or less, which is equivalent to the exhaust gas of an actual gasoline engine. The heat resistant tubular member can be evaluated and tested as a non-oxidizing atmosphere.

Next, a test apparatus for a heat-resistant tubular member according to the present invention is a test apparatus that heats the heat-resistant tubular member by flowing a high-temperature combustion gas by burning fuel with oxygen into a tubular portion of the heat-resistant tubular member. At least one combustion chamber connected to the tubular portion of the heat-resistant tubular member, a chamber portion communicating with the upstream side of the combustion chamber, a burner inserted into the chamber portion, a fuel supply path connected to the burner, and combustion Connected to at least one of the air supply path, the gas supply path connected to the chamber, the excess air supply path provided with the flow rate adjusting means connected to the gas supply path, and the gas supply path or the chamber And at least one of an oxygen gas supply path and an inert gas supply path provided with a flow rate adjusting means .

  The fuel supply path is the starting point for a gas source such as liquefied petroleum gas (hereinafter referred to as LPG) as fuel, and the combustion air supply path and the excess air supply path are the air compression means for supplying air to the starting point. The oxygen gas supply path has its start point connected to an oxygen supply source for supplying oxygen gas, and the inert gas supply path has its start point connected to an inert gas supply source for supplying inert gas. As the burner, various types such as a premixed or premixed gas burner or an oil burner can be used. In addition to valves and valves disposed on the piping of the excess air supply path, oxygen gas supply path, and inert gas supply path that are the supply paths for each gas, the flow rate adjusting means is a supply source for each gas. Rotation of air compression means, oxygen supply source, valves and valves provided in an inert gas supply source, or an engine that discharges gas to each gas supply source such as a blower, compressor, pump, etc. Any means may be used as long as the gas flow rate can be adjusted, such as a mechanism for directly adjusting the gas supply amount by adjusting the number or the like. When a valve or a valve is used, an electromagnetic valve or a mass flow controller is preferable. When adjusting the engine that discharges gas, an inverter or the like may be connected to adjust the engine speed or the like.

  Adjustment of the supply amount of excess air, oxygen gas, and inert gas can be performed by manually operating a valve or valve that is a flow rate adjusting means, or an engine that discharges gas, or by mechanically or electrically operating it. This can be done by adjusting the valve, the opening of the valve, or the rotational speed of the engine that discharges the gas. Further, the adjustment amount of the flow rate adjusting means in the feedback control of the oxygen content in the test atmosphere refers to an adjustment amount such as the opening of a valve or valve that is the flow rate adjusting means, or the rotational speed of the engine that discharges gas. . With the test apparatus having the above-described configuration, the test atmosphere can be freely controlled, and the heat-resistant tubular member test method of the present invention described above can be achieved.

  And an air compression means for supplying the increased pressure air to the start point of the excess air supply path, an oxygen supply source for supplying the increased pressure oxygen gas to the start point of the oxygen gas supply path, and / or the inertness. It is preferable to provide an inert gas supply source that feeds the increased inert gas to the starting point of the gas supply path. If an air compression means for supplying the increased pressure air and an oxygen supply source for supplying the increased pressure oxygen gas are provided, the test atmosphere is changed to an oxidizing atmosphere and the exhaust pressure is increased to increase the actual pressure. The engine exhaust gas can be almost equal to the exhaust gas. For this purpose, those capable of supplying a large amount of excess air and / or oxygen gas are preferable. As the air compression means, a blower or a compressor capable of supplying pressurized air having a discharge pressure of 0.15 MPa or more is desirable, and oxygen supply The source is preferably one that can supply oxygen gas having a purity of 95% or more, and is preferably equipped with an oxygen gas cylinder.

When the fuel is LPG whose main component is propane, the combustion reaction formula of propane is represented by C ₃ H ₈ + 5O ₂ → 4CO ₂ + 5H ₂ O. Therefore, the oxygen capacity required for complete combustion is 5 moles per 1 mole of LPG. In addition to supplying oxygen necessary for complete combustion from the combustion air supply path, excess air increased in pressure from the air compression means via the excess air supply path and / or from the oxygen supply source to the oxygen gas supply path The oxygen gas in the test atmosphere is set to a predetermined volume ratio to make the test atmosphere an oxidizing atmosphere and the exhaust pressure is increased to increase the actual engine The exhaust gas can be almost equal to the exhaust gas. When it is necessary to control the oxygen content in the test atmosphere particularly accurately, it is preferable to provide an oxygen supply source using an oxygen gas cylinder rather than an air compression means in order to easily adjust the flow rate. It is desirable to provide an oxygen source and a combination of air compression means alone or in combination.

  In addition, if an inert gas supply source for supplying the increased inert gas is provided, the test atmosphere is made non-oxidizing atmosphere, and the exhaust pressure is increased to substantially equal the actual engine exhaust gas. State. As the inert gas supply source, those capable of supplying nitrogen gas or argon gas having a purity of 95% or more are preferable, and a nitrogen gas cylinder or an argon gas cylinder is preferably provided. As an inert gas supply source, it is preferable to use a relatively inexpensive nitrogen gas cylinder. Even if oxygen necessary for combustion is supplied from the combustion air supply path, if an inert gas such as nitrogen gas with increased pressure is supplied, the oxygen content in the test atmosphere is set to a predetermined volume ratio, and the test is performed. The exhaust pressure can be further increased by making the atmosphere a non-oxidizing atmosphere.

  Further, in the heat resistant tubular member testing apparatus of the present invention, an oxygen sensor disposed in the tubular portion of the heat resistant tubular member, a control unit, the excess air supply path, the oxygen gas supply path, and the inert gas supply. It is preferable to provide a flow rate adjusting means disposed in any one or more of the paths. By adopting the above-described configuration of the test apparatus of the present invention, feedback control of the oxygen content in the test atmosphere is possible, and the oxygen content in the test atmosphere is more accurately stabilized so as to have a predetermined volume ratio. It is possible to achieve the test method of the present invention that is maintained.

  According to the present invention, an evaluation test in an oxidizing exhaust gas atmosphere to which a heat resistant tubular member for a diesel engine is exposed, or a non-oxidizing exhaust gas atmosphere to which a heat resistant tubular member for a gasoline engine is exposed. The heat resistance and durability of heat-resistant tubular members used in diesel engines and gasoline engines are considered only for heat-resistant tubular members, regardless of the type of engine, without waiting for the completion of the actual engine. It is possible to obtain a test method and a test apparatus capable of accurately evaluating and testing the properties.

  By using the heat resistant tubular member test method and test apparatus of the present invention, an evaluation test can be performed in advance prior to completion of the engine. It is easy to obtain a heat-resistant tubular member with excellent heat resistance and durability by using the evaluation test results for appropriate selection and design of the material, shape, dimensions, etc. of the heat-resistant tubular member. .

Next, embodiments of the invention will be described in detail.
(Embodiment 1)
FIG. 1 shows a test apparatus in the case where the heat-resistant tubular member in Embodiment 1 is an exhaust manifold 10. FIG. 1A is a plan view, and FIG. 1B is a schematic cross-sectional view of a main part. 2 shows a fuel supply path 31, a combustion air supply path 32, an oxygen gas / inert gas supply path 33, etc. for each of a plurality of (three as an example in FIG. 2) combustion chambers in the test apparatus of FIG. The circuit diagram of is shown.

  1 and 2, the test apparatus for the exhaust manifold 10 includes a combustion chamber 22 connected to each other via a combustion gas passage 21a of a cooling block 21 connected to a combustion gas inlet 41 of the tubular portion 11 of the exhaust manifold 10, and combustion. A chamber portion 23 communicating with the upstream side of the chamber 22, an original mixing burner 24 inserted into the chamber portion 23 to generate combustion gas, a fuel supply path 31 and a combustion air supply path 32 connected to the burner 24; , A gas supply path 35 connected to the chamber 23, an excess air supply path 35a connected to the gas supply path 35 for supplying excess air, and oxygen gas / for supplying an inert gas / And an inert gas supply path 33.

  Further, the combustion air supply path 32 and the excess air supply path 35a merge at the upstream side thereof, and a blower 36 is connected to the start point as air compression means capable of supplying pressurized air having a discharge pressure of 0.15 MPa or more. . Further, the oxygen gas / inert gas supply path 33 is branched into an oxygen gas supply path 33a and an inert gas supply path 33b on the upstream side thereof, and oxygen gas having a purity of 95% or more can be supplied to each starting point. An oxygen gas cylinder 34a is connected as an oxygen supply source, and a nitrogen gas cylinder 34b that can supply, for example, nitrogen gas is connected as an inert gas supply source capable of supplying an inert gas having a purity of 95% or more. Further, the fuel supply path 31 is connected to the LPG 31a with its starting point as a gas source for fuel.

  Further, the oxygen gas / inert gas supply path 33, the excess air supply path 35a, the fuel supply path 31 and the combustion air supply path 32 include flow rate adjusting valves 44a, 44b, 42a, which are flow rate adjusting means, on each supply path. And 42b, respectively, so that the flow rates of oxygen gas, inert gas, excess air, LPG 31a, and combustion air can be adjusted by the respective flow rate adjustment valves.

  Further, a gap 23b is provided between the inner wall 23a of the chamber 23 and the burner 24, and excess air or oxygen gas and / or inert gas is supplied from the gas supply path 35 and the oxygen gas / inert gas supply path 33. Can flow into the combustion chamber 22. With this configuration, excess air, oxygen gas, and inert gas enter the combustion chamber 22 through the gap 23b around the burner 24 and mix with the combustion gas there, so that the combustion conditions are not affected.

  Further, a cooling water inlet 21b and a discharge port 21c are formed in the cooling block 21, and the cooling water 21d is circulated to cool and protect the combustion gas passage 21a. The combustion chamber 22 and the chamber portion 23 are each formed of a fire-resistant ceramic tube 22a, a combustion chamber protection tube 22b, and a heat insulating portion 22c made of an air layer.

  In addition, an oxygen sensor (oxygen concentration meter) 43 that measures the oxygen content in the test atmosphere disposed in the tubular portion 11 of the exhaust manifold 10 by a volume ratio, a programmable temperature controller (not shown), and a computer ( The oxygen sensor 43, the control unit 46, and the flow rate adjusting valves 44a and 44b are connected so that control signals can be input and output.

  Using the test apparatus configured as described above, the heat resistance and durability of the exhaust manifold 10 are tested as follows. In the first embodiment, a test method in the case of an exhaust manifold for a diesel engine will be described using the test apparatus shown in FIGS. Exhaust manifolds for diesel engines are exposed to exhaust gases in an oxidizing atmosphere.

  First, the inlet 41 of the tubular portion 11 of the exhaust manifold 10 is attached so as to coincide with the combustion gas path 21a of the cooling block 21, and the LPG 31a is burned from the fuel supply path 31 and the air (atmosphere) is burned from the combustion air supply path 32, respectively. It is burned in the combustion chamber 22 by being fed to 24 and ignited. As a result, the flame emitted from the burner 24 is jetted into the combustion chamber 22, and the high-temperature combustion gas accompanying the flame flows through the combustion gas passage 21 a of the cooling block 21 to the tubular portion 11 of the exhaust manifold 10. At this time, the test atmosphere flowing through the tubular portion 11 is an oxidizing atmosphere having an oxygen content of 5% or more by volume ratio. In order to increase the pressure of the combustion gas, excess air is supplied to the combustion chamber 22 via the gap 23b through the gas supply path 35 via the excess air supply path 35a connected to the blower 36. By supplying this excess air, the test atmosphere is an oxidizing atmosphere having an oxygen content of about 10% by volume.

  At that time, the oxygen content in the test atmosphere is measured by the oxygen sensor 43, and if the oxygen content does not reach the desired target value, the valve of the oxygen gas cylinder 34a is adjusted and the excess air supply passage 35a is adjusted. While adjusting the pressure of the combustion gas with the flow rate adjusting valve 44b provided in the oxygen gas / inert gas supply path 33 and the flow rate adjusting valve 44a provided in the oxygen gas / inert gas supply path 33, excess air and oxygen gas / inert gas are passed through the excess air supply path 35a. If oxygen gas is supplied through the active gas supply path 33 and the oxygen content exceeds the target value, the valve of the nitrogen gas cylinder 34b is adjusted, and the flow rate adjustment valve 44b provided in the excess air supply path 35a and the oxygen gas / Nitrogen gas is fed through the oxygen gas / inert gas supply path 33 while adjusting the pressure of the combustion gas by the flow rate adjusting valve 44a provided in the inert gas supply path 33. Accordingly, by setting an arbitrary value to the desired oxygen content in the test atmosphere, which can be stably maintained. As described above, the test atmosphere can be controlled to be a predetermined oxidizing atmosphere by adjusting the flow rate adjusting valves 44a and 44b.

  In order to adjust the oxygen content in the test atmosphere more accurately, in addition to adjusting the flow rate adjusting valves 44a and 44b, the flow rate adjusting valve 42a on the fuel supply path 31 can be used to adjust the amount of LPG 31a to be fed and / or Alternatively, it is preferable to adjust the amount of combustion air supplied by the flow rate adjustment valve 42 b on the combustion air supply path 32.

  The above-described test method is based on the measurement result of the oxygen content of the oxygen sensor 43, and the actual evaluation test includes adjusting the valves of the oxygen gas cylinder 34a and the nitrogen gas cylinder 34b and adjusting the flow rate adjusting valves 44a and 44b. However, the flow rate adjusting valves 44a and 44b are operated using feedback control to control the supply amount of excess air, oxygen gas, and nitrogen gas. It can also be adjusted.

  In the feedback control, the oxygen gas cylinder 34a and the nitrogen gas cylinder 34b are opened, and a detection signal of the oxygen content measured by the oxygen sensor 43 is input to the control unit 46, and the target oxygen content is detected by the control unit 46. Is compared with the actually measured oxygen content, for example, an opening degree that is an adjustment amount of the flow rate adjustment valve necessary to correct the excess or deficiency of the oxygen content is calculated, and the opening degree of the valve is added to the flow rate adjustment valves 44a and 44b. A control signal for adjusting the flow rate is output, and the flow rate adjusting valves 44a and 44b are mechanically and electrically operated to adjust the supply amounts of excess air, oxygen gas, and nitrogen gas. As a result, feedback control is performed so that the oxygen content in the test atmosphere becomes a desired value, so that the oxygen content can be maintained more accurately and stably. Can be controlled.

  In order to adjust the oxygen content in the test atmosphere more accurately, in addition to adjusting the flow rate adjusting valves 44a and 44b by feedback control, a control signal based on the calculation result is sent from the control unit 46 to the flow rate adjusting valves 42a and 42b. Is also preferable to adjust the supply amount of LPG 31a and / or combustion air, respectively, because the oxygen content in the test atmosphere can be more accurately and stably maintained.

  Further, a temperature sensor 41a that measures the temperature of the test atmosphere at the combustion gas inlet 41 of the tubular portion 11 of the exhaust manifold 10 and a plurality of surfaces that measure the temperature distribution of the surface of the exhaust manifold 10 on the surface 11a that contacts the outside air of the tubular portion 11 are provided. Temperature sensor 41b, and the detection signal of the temperature of the test atmosphere and the surface temperature of the exhaust manifold 10 measured by the temperature sensors 41a and 41b are input to the control unit 46, and the target temperature and the actually measured temperature are obtained by the control unit 46. For example, an opening degree that is an adjustment amount of the flow rate adjustment valve necessary for correcting the excess or deficiency of the temperature is calculated, and a control signal for adjusting the opening degree of the valve is output to the flow rate adjustment valves 42a, 42b, 44b, If the flow rate regulating valves 42a, 42b, 44b are operated to adjust the amount of fuel, air necessary for combustion, and excess air, the temperature of the test atmosphere The enabling raised to a high temperature of at least 1000 ° C., it can be controlled to be substantially equal state exhaust gas temperature of the test atmosphere actual diesel engine. Thermocouples can be used as the temperature sensors 41a and 41b.

  In order to confirm the effect of the test method and test apparatus of the first embodiment, the target value of the oxygen content in the test atmosphere is set to 16% by volume ratio, and the test is performed for about 10 minutes from the start of the test (burner 24 ignition). The oxygen content in the atmosphere was measured. As a result, the oxygen content actually measured by the oxygen sensor 43 was 15.5 to 16.7% when manually adjusted, and 15.9 to 16.3% when feedback control was performed. When adjusted manually, the variation from the target value is slightly larger than when feedback control is performed. However, the actual measured oxygen content is almost the same as the target value, and the test atmosphere is used as a predetermined oxidizing atmosphere for diesel engines. This was confirmed to be appropriate for conducting an exhaust manifold evaluation test. In addition, it is confirmed that oxygen can be contained in the test atmosphere up to about 100% by adjusting the supply amounts of excess air and oxygen gas by the flow rate adjusting valves 44a and 44b. It was confirmed that it has sufficient functions to reproduce the gas.

  As described above, after adjusting the test apparatus to a predetermined oxidizing atmosphere, the burner 24 is ignited to burn the LPG 31a, and the temperature of the test atmosphere is raised from, for example, near room temperature to a high temperature of about 1000 ° C. After holding for a predetermined time, the supply of the LPG 31a is reduced or stopped and returned to near room temperature again, so that a heating / cooling thermal cycle is applied to the exhaust manifold 10 in the same manner as in an actual diesel engine. At the time of cooling, the temperature of the test atmosphere is low and the influence of oxidation is slight, so the supply may be stopped to save oxygen gas and nitrogen gas.

  7 is a micrograph of the tubular portion 11 of the exhaust manifold 10 after the thermal cycle test using the test method and test apparatus of the first embodiment. As shown in FIG. 7, many cracks 13 are generated from the oxide film 12 on the surface 11 a of the inner wall of the tubular portion 11, which grows and propagates inside the material of the tubular portion 11 to become a surface in contact with the outside air. It is a penetration crack 14 up to the back surface 11b.

  If the test method and test apparatus of the first embodiment are used, the heat resistance of the exhaust manifold in an oxidizing atmosphere equivalent to the exhaust gas of an actual diesel engine is intended only for the exhaust manifold prior to completion of the diesel engine. Therefore, it is possible to accurately evaluate the durability, etc., so that the development period of the exhaust manifold can be shortened and the cost of the evaluation test with a diesel engine can be reduced, and the evaluation test results can be reduced, for example, by forming less oxide film. It becomes easy to obtain an exhaust manifold excellent in heat resistance, durability, etc. by making use of appropriate selection and design of the material, shape, dimensions, etc. of the exhaust manifold so as to reduce the occurrence of cracks and penetration cracks.

(Embodiment 2)
The second embodiment is a test method in the case of an exhaust manifold for a gasoline engine. Exhaust manifolds for gasoline engines are exposed to exhaust gases in a non-oxidizing atmosphere. Since the test apparatus having the same configuration as that of the first embodiment shown in FIGS. 1 and 2 can be used, the description thereof is omitted.

  First, the inlet 41 of the tubular portion 11 of the exhaust manifold 10 is attached so as to coincide with the combustion gas path 21a of the cooling block 21, and the LPG 31a is burned from the fuel supply path 31 and the air (atmosphere) is burned from the combustion air supply path 32, respectively. It is burned in the combustion chamber 22 by being fed to 24 and ignited. As a result, the flame emitted from the burner is jetted into the combustion chamber 22, and the high-temperature combustion gas accompanying the flame flows through the combustion gas passage 21 a of the cooling block 21 to the tubular portion 11 of the exhaust manifold 10. At this time, the test atmosphere flowing through the tubular portion 11 is an oxidizing atmosphere having an oxygen content of 5% or more by volume ratio.

  Next, nitrogen gas is used to increase the pressure of the combustion gas instead of excess air that promotes oxidation. Specifically, the valve of the oxygen gas cylinder 34a and the flow rate adjustment valve 44b provided in the excess air supply path 35a Are closed, the valve of the nitrogen gas cylinder 34b is opened, the flow rate adjusting valve 44a is adjusted, and nitrogen gas having a purity of 95% or more is passed through the oxygen gas / inert gas supply passage 33 to the combustion chamber 22 through the gap 23b. The oxygen content in the test atmosphere is reduced while adjusting the pressure of the combustion gas with the pressure of nitrogen gas, and a predetermined non-oxidizing atmosphere is obtained.

  Since the exhaust gas of a general gasoline engine contains a little oxygen of less than 5%, in order to reproduce this, the valve of the nitrogen gas cylinder 34b is opened and the flow rate of the excess air supply passage 35a is adjusted. While the valve 44b or the oxygen gas cylinder 34a is opened and the oxygen content in the test atmosphere is measured by the oxygen sensor 43, the flow rate adjusting valves 44a and 44b, which are flow rate adjusting means, are adjusted to supply nitrogen gas. In addition to the above, by adjusting the supply amount of excess air or oxygen gas, the oxygen content in the test atmosphere can be set to any desired value, and this can be stably maintained to maintain the test atmosphere in a predetermined non-oxidized state. Try to have a sex atmosphere. In the second embodiment, similarly to the first embodiment, the adjustment of the flow rate adjustment valves 44a and 44b may be set by manually operating in advance, or the oxygen sensor 43, the control unit 46, and the flow rate adjustment. It may be performed by feedback control of the test atmosphere in conjunction with the valves 44a and 44b.

  In order to more accurately adjust the oxygen content in the test atmosphere, the flow rate adjusting valve 42a on the fuel supply path 31 and the LPG 31a feed rate and / or the flow rate adjusting valve 42b on the combustion air supply path 32 burns. It is preferable to adjust the supply amount of the working air.

  In order to confirm the effect of the test method and test apparatus of the second embodiment, the target value of the oxygen content in the test atmosphere is set to 0% by volume ratio, and the test is performed for about 10 minutes from the start of the test (burner 24 ignition). The oxygen content in the atmosphere was measured. At this time, both the flow rate adjustment valve 44b of the excess air supply passage 35a and the valve of the oxygen gas cylinder 34a are closed, the excess air and oxygen gas are not supplied, the valve of the nitrogen gas cylinder 34b is opened, and the oxygen gas / The flow rate adjustment valve 44a of the inert gas supply path 33 was manually set to adjust the nitrogen gas supply amount to a target value.

  FIG. 8 shows the measurement results of the oxygen content in the test atmosphere in the second embodiment. For comparison, the measurement result (broken line) of the oxygen content in the conventional test apparatus disclosed in Patent Document 1 is also shown. From FIG. 8, the oxygen content in the test atmosphere in the conventional test equipment that does not control the test atmosphere has been around 9.2 to 10.7%, which is about 10%, which is compared with the actual gasoline engine. It is clear that oxygen is an excessive oxidizing atmosphere. On the other hand, according to the test method and the test apparatus of the second embodiment, the oxygen content becomes almost 0% within about 30 seconds after the start of the test, and thereafter changes from 0 to 1.0% until the end of the test. It was confirmed that a non-oxidizing atmosphere in which the oxygen content can be maintained and the oxygen content in the test atmosphere is approximately 0% can be obtained.

  Similarly, when the oxygen content was measured using feedback control, the oxygen content was almost 0% within about 30 seconds after the start of the test, and then 0 to 0.4 until the end of the test. It was confirmed that the oxygen content can be maintained more accurately and stably than in the case of manual adjustment.

  In both cases of manual adjustment and feedback control, a very small amount of oxygen may be detected with respect to the target oxygen content of 0%, and this is distributed from the combustion air supply path 32. Among the oxygen components in the air, the trace amount of oxygen that was not consumed during the combustion of the fuel and the trace amount of oxygen as impurities contained in the nitrogen gas cylinder 34b exist in the test atmosphere. It is estimated that it varies due to fluctuations in salary. However, this level of error is considered to have occurred even in an actual gasoline engine, and it is judged that there is almost no influence on the evaluation test of the heat-resistant tubular member. In both cases of manual adjustment and feedback control, the temperature of the test atmosphere exceeded 1000 ° C within about 30 seconds after the start of the test, and it was possible to reproduce a state almost equal to the exhaust gas of an actual gasoline engine. It was.

  According to the test method and the test apparatus of the second embodiment, the target value of the oxygen content in the test atmosphere and the actual measurement value substantially coincide, and the exhaust gas of the gasoline engine is reproduced with the test atmosphere as a predetermined non-oxidizing atmosphere. Therefore, it has been confirmed that it has sufficient functions and is suitable for performing an exhaust manifold evaluation test.

  As described above, after adjusting the test apparatus to a predetermined non-oxidizing atmosphere, the burner 24 is ignited to burn the LPG 31a, and the temperature of the test atmosphere is increased from, for example, near room temperature to a high temperature of about 1000 ° C. Is held for a predetermined time, and the LPG 31a feed is reduced or stopped and returned to near room temperature again, so that a heating / cooling thermal cycle is applied to the exhaust manifold 10 in the same manner as in an actual gasoline engine. At the time of cooling, the temperature of the test atmosphere is low and the influence of oxidation is slight, so the supply may be stopped to save oxygen gas and nitrogen gas.

  If the test method and test apparatus of the second embodiment are used, the heat resistance of the exhaust manifold in a non-oxidizing atmosphere equivalent to the exhaust gas of an actual gasoline engine is intended only for the exhaust manifold prior to completion of the gasoline engine. As a result, the development period of the exhaust manifold can be shortened and the cost of the evaluation test on the actual gasoline engine can be reduced, and the evaluation test results can be reduced, for example, by forming less oxide film. Appropriate selection and design of the exhaust manifold material, shape, dimensions, etc. to reduce the occurrence of cracks and through cracks, etc. makes it easy to obtain an exhaust manifold with excellent heat resistance and durability. .

(Embodiment 3)
FIG. 3 is a schematic cross-sectional view of the heat-resistant tubular member testing apparatus according to the third embodiment. The test apparatus of the third embodiment is the same as that of the first embodiment shown in FIGS. 1 and 2 except that the oxygen gas / inert gas supply path 33 is directly connected to the chamber 23 separately from the gas supply path 35. The configuration is almost the same.
In the test apparatus according to the third embodiment, the oxygen gas / inert gas supply path 33 and the gas supply path 35 are individually connected to the chamber 23, and therefore the oxygen gas / inert gas supply path 33 is fed from the oxygen gas / inert gas supply path 33. Supply amount of each gas to be supplied without interference between oxygen gas and / or nitrogen gas to be supplied and excess air supplied from the gas supply path 35 via the excess air supply path 35a Is more stable, so that the oxygen content in the test atmosphere can be more stably maintained.

  Also in the third embodiment, as in the first or second embodiment, the test atmosphere is changed to the oxygen gas from the oxygen gas / inert gas supply path 33 to the combustion chamber 22 by opening the valve of the oxygen gas cylinder 34a. The nitrogen gas is sent from the oxygen gas / inert gas supply path 33 to the combustion chamber 22 by adjusting the flow rate adjusting valves 44a and 44b to make the oxidizing atmosphere or opening the nitrogen gas cylinder 34b. By adjusting the flow rate adjusting valves 44a and 44b, the test atmosphere can be freely controlled from an oxidizing atmosphere to a non-oxidizing atmosphere, and heat resistance can be achieved without waiting for the completion of the engine. It is possible to accurately evaluate and test the heat resistance and durability of the heat-resistant tubular member in an atmosphere equivalent to the exhaust gas of an actual engine only for the tubular member.

(Embodiment 4)
FIG. 4 is a schematic cross-sectional view of a heat resistant tubular member testing apparatus according to the fourth embodiment. The test apparatus of the fourth embodiment does not include the oxygen gas cylinder 34a and the nitrogen gas cylinder 34b, connects the oxygen gas / inert gas supply path 33 and the gas supply path 35 to the chamber 23, and connects the oxygen gas / The configuration is almost the same as that of the first embodiment shown in FIGS. 1 and 2 except that the flow rate adjustment valve 44a of the inert gas supply path 33 and the flow rate adjustment valve 44b of the gas supply path 35 are made one.

  The test apparatus according to the fourth embodiment does not require the oxygen gas cylinder 34a and the nitrogen gas cylinder 34b, and the oxygen gas / inert gas supply path 33 and the flow rate adjusting valve 44a disposed in the oxygen gas cylinder 34a can be omitted. In addition, since the configuration is simple, the maintenance of the test apparatus is easy, and the cost for the evaluation test can be reduced because expensive oxygen gas and nitrogen gas are not used.

  Also in the fourth embodiment, as in the first or third embodiment, excess air is supplied from the gas supply path 35 to the combustion chamber 22 via the excess air supply path 35a connected to the blower 36. By adjusting the flow rate adjusting valve 44b, the pressure of the combustion gas can be increased and the oxygen content in the test atmosphere can be increased to make an oxidizing atmosphere, which is used exclusively as a test apparatus for heat-resistant tubular members for diesel engines. It is possible to accurately evaluate and test the heat resistance, durability, etc. of heat-resistant tubular members in an oxidizing atmosphere equivalent to the exhaust gas of actual diesel engines only for heat-resistant tubular members, without waiting for the completion of the diesel engine .

(Embodiment 5)
FIG. 5 is a schematic cross-sectional view of the heat-resistant tubular member testing apparatus according to the fifth embodiment. The test apparatus of the fifth embodiment separates the oxygen gas supply path 33a and the inert gas supply path 33b, which are merged on the upstream side of the oxygen gas / inert gas supply path 33 in the first embodiment, The inert gas supply path 33b is directly connected to the chamber 23 separately from the gas supply path 35, and the downstream side circuit of the gas supply path 33a is left as it is, and the oxygen gas supply path 33a and the inert gas supply path 33b are respectively connected. The configuration is almost the same as that of the first embodiment shown in FIGS. 1 and 2 except that the flow rate adjusting valves 45a and 45b are provided.

  In the test apparatus of the fifth embodiment, the oxygen gas supply path 33a and the inert gas supply path 33b are separated, and the inert gas supply path 33b and the gas supply path 35 are individually connected to the chamber 23. Therefore, the supply amount of each gas supplied without interference between the nitrogen gas supplied from the inert gas supply path 33b and the oxygen gas supplied from the oxygen gas supply path 33a is more stable. In addition, since the oxygen gas supply passage 33a and the inert gas supply passage 33b are provided with flow rate adjusting valves 45a and 45b, respectively, the oxygen gas and nitrogen gas supply amounts can be controlled more accurately, so that oxygen in the test atmosphere can be controlled. The content can be maintained more accurately and stably.

  Also in the fifth embodiment, as in the first or second embodiment, the test atmosphere is opened from the gas supply path 35 via the oxygen gas supply path 33a by opening the valve of the oxygen gas cylinder 34a. 22 is supplied with oxygen gas, and the flow rate adjusting valves 45a and 44b are adjusted to create an oxidizing atmosphere, or the nitrogen gas cylinder 34b is opened to supply nitrogen gas from the inert gas supply passage 33b to the combustion chamber 22. It is possible to freely control the test atmosphere from an oxidizing atmosphere to a non-oxidizing atmosphere as a non-oxidizing atmosphere by adjusting the flow rate adjusting valves 45b and 44b, and without waiting for the completion of the engine, It is possible to accurately evaluate and test the heat resistance and durability of the heat resistant tubular member only in the heat resistant tubular member in an atmosphere equivalent to the exhaust gas of an actual engine.

(Embodiment 6)
FIG. 6 is a schematic cross-sectional view of a heat-resistant tubular member test apparatus according to the sixth embodiment. The test apparatus according to the sixth embodiment separates the oxygen gas supply path 33a and the excess air supply path 35a that merge together on the upstream side of the gas supply path 35 according to the fifth embodiment, and downstream of the excess air supply path 35a. The circuit on the side is the same as that in the fifth embodiment shown in FIG. 5 except that the oxygen gas supply path 33a is directly connected to the chamber 23 separately from the gas supply path 35.

  In the test apparatus according to the sixth embodiment, the oxygen gas supply path 33a, the inert gas supply path 33b, and the gas supply path 35 are individually connected to the chamber 23, so that the gas is supplied from the oxygen gas supply path 33a. The oxygen gas supplied, the nitrogen gas supplied from the inert gas supply path 33b, and the excess air supplied from the gas supply path 35 via the excess air supply path 35a are sent without interference. The supply amount of each gas to be supplied is further stabilized, and the flow rate adjusting valves 45a, 45b, and 44b provided in the oxygen gas supply path 33a, the inert gas supply path 33b, and the excess air supply path 35a, respectively. Since the oxygen gas, the nitrogen gas and the excess air can be individually and accurately controlled, the oxygen content in the test atmosphere can be maintained more accurately and stably.

  Also in the sixth embodiment, as in the first or second embodiment, the test atmosphere is set to open the valve of the oxygen gas cylinder 34a, and oxygen gas is supplied from the oxygen gas supply path 33a to the combustion chamber 22. By adjusting the flow rate adjusting valves 45a and 44b, an oxidizing atmosphere is created or the valve of the nitrogen gas cylinder 34b is opened, and nitrogen gas is supplied from the inert gas supply passage 33b to the combustion chamber 22, and the flow rate adjusting valve 45b. By adjusting 44b, the test atmosphere can be freely controlled from the oxidizing atmosphere to the non-oxidizing atmosphere as a non-oxidizing atmosphere, and only the heat-resistant tubular member is actually targeted without waiting for the completion of the engine. The heat resistance, durability, etc. of the heat resistant tubular member can be accurately evaluated and tested in an atmosphere equivalent to the engine exhaust gas.

(Embodiment 7)
Next, an embodiment in which a heat cycle of heating / cooling is applied to the heat-resistant tubular member using the heat-resistant tubular member testing method and test apparatus of the present invention will be described. FIG. 9 is a time-temperature diagram of a thermal cycle when the heat-resistant tubular member is subjected to an evaluation test. (A) is a diagram assuming start, operation, and stop of the automobile, and (b) is start and operation of the automobile. In addition to the stop, a diagram that assumes an autobahn traveling, which will be described later, is shown. In FIG. 9, 71 is a time-temperature diagram of the test atmosphere at the inlet of the tubular portion of the heat-resistant tubular member, and 72 is a time-temperature diagram of the surface in contact with the outside air of the tubular portion of the heat-resistant tubular member.

  First, FIG. 9 (a) is an example of a thermal cycle that assumes start, operation, and stop of an automobile. The temperature of the test atmosphere at the entrance of the tubular portion of the heat-resistant tubular member is increased to a predetermined heating temperature t1. Thereafter, a heating step H for heating the heat-resistant tubular member by holding the temperature t1 for a predetermined time, and then a cooling step C for cooling the heat-resistant tubular member by lowering the temperature of the test atmosphere to near normal temperature are sequentially repeated. In this test method, a heat cycle R1 in a test atmosphere is created and a heat cycle of heating and cooling is applied to the heat-resistant tubular member. In FIG. 9 (a), as test conditions, the heating temperature t1 of the test atmosphere is 1000 ° C., the holding time of t1 is about 8 minutes, the heating process H10 minutes, and the cooling process C1 / 10 cycle is 20 minutes. The case where the cycle R1 is 500 cycles (not shown) is illustrated. Under the test conditions, the heating temperature t2 of the surface of the tubular portion of the heat-resistant tubular member in contact with the outside air was about 800. As shown in the diagram of FIG. 9A, the evaluation test of the heat-resistant tubular member is usually performed by imitating the actual operating state of the engine assuming the actual start, operation, and stop of the automobile. By applying a heat cycle by raising and lowering the temperature, the heat resistant tubular member is subjected to a heating / cooling heat cycle.

  Moreover, if the heat resistant tubular member test method and test apparatus of the present invention are used, a special heating / cooling heat cycle can be applied to the heat resistant tubular member. For example, in European autobahns, when driving a car at a high speed of 100 km / h or higher and 200 km / h or higher, the accelerator is fully opened and the vehicle is accelerated instantaneously to overtake the preceding car. There are cases where the vehicle travels repeatedly by decelerating and returning to the speed before passing. In the case of traveling that accelerates by further depressing the accelerator during high-speed traveling, compared to simply traveling at high speed at a constant speed, a higher thermal and mechanical load is applied to the heat-resistant tubular member. This is considered to affect the heat resistance and durability of the member. Therefore, in addition to starting, driving, and stopping the automobile, an example of a heat cycle in an evaluation test of a heat-resistant tubular member assuming that the vehicle further decelerates after depressing the accelerator during high-speed traveling such as autobahn traveling is shown in the figure. It is a time-temperature diagram of the thermal cycle of 9 (b).

  FIG. 9B shows a heating step H in which the temperature of the test atmosphere is raised to the predetermined heating temperature t1 and the temperature of the test atmosphere is lowered to near room temperature, as in FIG. 9A. The cooling process C for cooling the heat-resistant tubular member is sequentially repeated to create a heat cycle R1 of the test atmosphere, and the heat-resistant tubular member is subjected to heating / cooling heat cycle, assuming start-up, operation, and stop in an actual vehicle. Simulates the actual operating state of the engine. Further, in FIG. 9B, after the temperature of the test atmosphere is raised to the heating temperature t1 in the heating step H, the temperature of the test atmosphere is increased and lowered from the heating temperature t1 by a predetermined temperature width t3 a plurality of times. Is given. Thereby, during the heating process H, a special heat cycle in which the heat-resistant tubular member is repeatedly heated and cooled a plurality of times is added. In FIG. 9B, as test conditions, the heating temperature t1 of the test atmosphere is 1000 ° C., the number of repetitions in which the temperature range t3 of the rise and fall in the thermal cycle R2 is 50 ° C. or more is 7 times, the heating step H10 minutes, the cooling step The case where the cycle of C1 / 10 was 20 minutes and the thermal cycle R1 of the test atmosphere was 500 cycles (not shown) was illustrated. It has been confirmed that the heating temperature t2 of the surface of the tubular portion of the heat-resistant tubular member in contact with the outside air under the test conditions is repeatedly increased and decreased several times corresponding to the thermal cycle R2 of the test atmosphere in the range of about 800 to 810 ° C. It was done.

  In order to create the heat cycle R2 of the test atmosphere, after the heating temperature t1 of the test atmosphere is reached in the heating step H, the fuel supply amount is slightly increased from the supply amount holding the heating temperature t1, and then the heating temperature t1. It is sufficient to repeat the return to the feeding amount that holds the number of times. As shown in the diagram of FIG. 9B, after the temperature of the test atmosphere is raised to a predetermined heating temperature t1, the heat cycle R2 is repeated a plurality of times from the heating temperature t1 at a predetermined temperature width t3. In addition to starting, driving, and stopping the actual vehicle, the heat-resistant tubular member simulates the actual operating state of the engine, assuming that the vehicle decelerates after accelerating by further depressing the accelerator during high-speed driving such as outburning. A special heat cycle of heating / cooling can be added.

  In addition, the temperature of the test atmosphere is controlled in addition to the test atmosphere heating in FIG. 9 (a), (b) up to the heating temperature t1, the rise / fall in the temperature range t3, the drop to near room temperature, etc. In order to provide the thermal cycles R1 and R2 of the atmosphere, as described in the first embodiment, the temperature of the test atmosphere measured by the temperature sensors 41a and 41b provided in the tubular portion of the heat resistant tubular member, and the surface of the heat resistant tubular member A temperature detection signal is input to the control unit 46, and the control unit 46 compares the target temperature with the actually measured temperature, and corrects the excess or deficiency of the temperature. And outputs a control signal for adjusting the opening degree of the valve to the flow rate adjusting valves 42a, 42b, 44b, and operates the flow rate adjusting valves 42a, 42b, 44b to send fuel, air necessary for combustion, and excess air. Salary As a result, the heating temperature t1, the temperature width t3, the temperature drop in the cooling process C, and the like can be controlled, and the heating temperature t1 and the temperature width t3 can be controlled by a programmable temperature controller and a computer built in the control unit 46. Before the evaluation test, the target temperature such as the temperature drop in the cooling process C, the holding time thereof, the number of repetitions of the rise and fall of the test atmosphere temperature, etc. are programmed in advance prior to the evaluation test. Thermal cycles R1, R2 can be provided.

  Further, the heating temperature t1 and the temperature range t3 in the test atmosphere need to correspond to the exhaust gas temperature exhausted from the actual engine, but the type, design / specification of the engine for each car manufacturer, the actual traveling speed, etc. Therefore, it is appropriately determined according to the demand of the supply destination of the heat-resistant tubular member. Generally, exhaust gas exhausted from the engine at a speed of 100 km / h or higher reaches 800 ° C. or higher, and when the accelerator is fully opened and momentarily accelerated to overtake the preceding car during high speed driving, the exhaust gas is further 30 ° C. It is said that hot exhaust gas is exhausted. Therefore, the heating temperature t1 is preferably 800 ° C. or higher, and the temperature width t3 is preferably 30 ° C. or higher.

  Using the heat-resistant tubular member test method and test apparatus of the present invention, in addition to a thermal cycle that assumes the start, operation, and stop of an automobile, a special thermal cycle that assumes an autobahn run, etc. It is possible to perform an evaluation test of the heat-resistant tubular member by reproducing the operating state of the engine. Although the two types of heating / cooling thermal cycle patterns shown in FIGS. 9A and 9B are shown in the seventh embodiment, this is merely an example, and the test method and test for the heat-resistant tubular member of the present invention. Needless to say, the apparatus can reproduce a heating / cooling thermal cycle pattern based on the exhaust gas temperature assuming various driving conditions of the automobile. For example, the heat resistance of heat-resistant tubular members can be reproduced by reproducing the driving pattern defined by the standards for each car manufacturer for engine performance evaluation, the standards of the automobile industry, or the standards of the laws and regulations of each country regarding exhaust gas and fuel consumption. It is also possible to evaluate durability and the like. Moreover, according to the present invention, the oxygen content in the test atmosphere is arbitrarily adjusted to reproduce the atmosphere of the exhaust gas from oxidizing to non-oxidizing, and only the heat-resistant tubular member is obtained without waiting for the completion of the actual engine. As a target, regardless of the type of engine, it is possible to accurately evaluate and test the heat resistance, durability, and the like of a heat-resistant tubular member used in a diesel engine or a gasoline engine.

  The above-mentioned “adjustment” of the flow regulating valve in the first to seventh embodiments specifically refers to, for example, changing the valve opening ratio from 0% (closed) to 100% (fully opened). In addition, the term “open” of the oxygen gas cylinder and nitrogen gas cylinder valves and the respective flow rate regulating valves specifically means that, for example, the valve or the opening ratio of the valve does not include 0% (closed), but 0%. It means exceeding (in a state where gas slightly flows) and changing to 100% (fully open).

  As mentioned above, although the test method and test apparatus of the heat-resistant tubular member of the present invention have been described according to the embodiments of the present invention, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the technical idea of the present invention. It goes without saying that variations are possible and are within the scope of the present invention.

  For example, a plurality of flow regulating valves are arranged on each gas supply path, a pressure booster, a rectifier, a surge tank, etc. are arranged on each gas supply path, or a mixer is installed at the confluence of each gas on the supply path. If a means usually used for adjusting the flow rate and pressure of gas, such as disposing, is added, the test atmosphere can be adjusted and controlled more precisely and finely.

  In addition, the air compression means, oxygen supply source, and inert gas supply source are not dedicated to the test apparatus, but are supplied from any one of compressor air, oxygen gas, and inert gas commonly used in the office. If there is, it may be connected to the pipe. The cooling block 21 is a member such as a cylinder head of an engine, for example. However, depending on the type of the heat-resistant tubular member, there may be a case where the cooling block 21 is not provided. Further, the cooling water 21d is circulated in the cooling block 21, and the heat insulating portion 22c of the combustor 20 is an air layer. However, in the cooling block 21 and the heat insulating portion 22c, bricks, asbestos, Various ceramic materials may be inserted.

  The heat-resistant tubular member test method and test apparatus of the present invention are not limited to automobile internal combustion engines, but are used in various internal combustion engines such as railway locomotives, construction machinery, ships, industrial and power generation diesel engines. It goes without saying that it can also be used for evaluation tests of exhaust system equipment and the like.

1 is a test apparatus for an exhaust manifold 10 according to Embodiment 1, wherein (a) is a plan view and (b) is a schematic cross-sectional view of a main part. FIG. 2 is a circuit diagram of a fuel supply path, a combustion air supply path, an oxygen gas / inert gas supply path, and the like for each of a plurality of combustion chambers in the test apparatus of FIG. 1. 6 is a schematic cross-sectional view of a heat-resistant tubular member testing apparatus according to Embodiment 3. FIG. FIG. 6 is a schematic cross-sectional view of a heat-resistant tubular member testing apparatus in a fourth embodiment. FIG. 10 is a schematic cross-sectional view of a heat-resistant tubular member testing apparatus in a fifth embodiment. FIG. 10 is a schematic cross-sectional view of a heat resistant tubular member testing apparatus in a sixth embodiment. It is a microscope picture of the tubular part 11 of exhaust manifold 10 after a heat cycle test. FIG. 6 is a diagram showing a measurement result of oxygen content in a test atmosphere in the second embodiment. It is the time-temperature diagram of the heat cycle which evaluates and tests a heat-resistant tubular member, (a) is a diagram which assumed start of a car, operation, and a stop, (b) is a diagram that assumed autobahn driving of a car, etc. is there. It is a schematic cross section from the formation of an oxide film to the tubular portion 11 of the heat-resistant tubular member to the occurrence of a through crack.

Explanation of symbols

10: Exhaust manifold (heat resistant tubular member)
11: Tubular part 11a: Front surface 11b: Back surface 12: Oxide film 13: Crack 14: Through crack A: Atmosphere 20: Combustor 21: Cooling block 21a: Combustion gas path 21b: Inlet 21c: Outlet 21d: Cooling Water 22: Combustion chamber 22a: Ceramic tube 22b: Combustion chamber protection tube 22c: Heat insulation portion 23: Chamber portion 23a: Inner wall 23b: Gap 24: Burner 31: Fuel supply path 31a: LPG (liquefied petroleum gas)
32: Combustion air supply path 33: Oxygen gas / inert gas supply path 33a: Oxygen gas supply path 33b: Inert gas supply path 34a: Oxygen gas cylinder 34b: Nitrogen gas cylinder 35: Gas supply path 35a: Excess air supply path 36: Blower 41: Combustion gas inlet 41a, 41b: Temperature sensor 42a, 42b: Flow rate adjusting valve 43: Oxygen sensor (oxygen concentration meter)
44a, 44b, 45a, 45b: Flow rate adjusting valve 46: Control unit 71: Time-temperature diagram of test atmosphere 72: Time-temperature diagram of heat-resistant tubular member H: Heating step C: Cooling step R1, R2: Test atmosphere T1: Heating temperature of test atmosphere t2: Heating temperature of heat-resistant tubular member surface t3: Temperature range

Claims (8)

A test method in which fuel is burned with oxygen in a tubular portion of a heat-resistant tubular member and a high-temperature combustion gas is flowed to heat the heat-resistant tubular member, and at least one combustion chamber connected to the tubular portion of the heat-resistant tubular member A chamber communicating with the upstream side of the combustion chamber, a burner inserted into the chamber, a fuel supply path and a combustion air supply path connected to the burner, and a gas supply path connected to the chamber And an excess air supply path having a flow rate adjusting means connected to the gas supply path, and an oxygen gas supply path further having a flow rate adjusting means connected to at least one of the gas supply path or the chamber, inert Using a test apparatus having any one or more of gas supply paths, fuel supplied from the fuel supply path in a state where the tubular portion is connected to a combustion chamber is supplied from the combustion air supply path. Burn with air, With introducing was combustion gas into the combustion chamber, at least than one said combustion chamber of the gas supply channel or the chamber, feeding at least oxygen gas, one or more or inert gas feeds, the At this time, the flow rate of one or more of the excess air, the oxygen gas, and the inert gas is set so that the atmosphere (test atmosphere) in the tubular portion of the heat-resistant tubular member becomes an atmosphere exposed to the actual exhaust gas. A method for testing a heat-resistant tubular member, wherein the flow rate adjusting means adjusts the heat-resistant tubular member.   In addition to air necessary for combustion, at least one of excess air, oxygen gas, and inert gas is supplied into the combustion chamber, and the pressure of the combustion gas is increased to atmospheric pressure or higher. The test method of the heat-resistant tubular member according to claim 1.   An oxygen sensor disposed in a tubular portion of the heat-resistant tubular member, a control unit, and a flow rate adjusting means disposed in any one or more of the excess air supply path, the oxygen gas supply path, and the inert gas supply path. The detection signal of the oxygen content measured by the oxygen sensor is input to the control unit, and the target oxygen content measured by the control unit is compared with the actually measured oxygen content. The amount of adjustment of the flow rate adjusting means necessary for correcting the flow rate is calculated, a control signal of the amount of adjustment is output to the flow rate adjusting means, and the flow rate adjusting means is operated to operate the atmosphere in the tubular portion of the heat resistant tubular member (test The method for testing a heat-resistant tubular member according to claim 1 or 2, wherein the oxygen content in the atmosphere) is adjusted to a predetermined volume ratio.   The oxygen content in the atmosphere (test atmosphere) in the tubular portion of the heat-resistant tubular member is set to an arbitrary value of 0.01% or more and less than 21% by volume ratio. A test method for a heat-resistant tubular member according to claim 1. At least one combustion chamber connected to the tubular portion of the heat-resistant tubular member, which is a test apparatus that heats the heat-resistant tubular member by flowing a high-temperature combustion gas by burning fuel with oxygen into the tubular portion of the heat-resistant tubular member. A chamber communicating with the upstream side of the combustion chamber, a burner inserted into the chamber, a fuel supply path and a combustion air supply path connected to the burner, and a gas supply path connected to the chamber And an excess air supply path having a flow rate adjusting means connected to the gas supply path, and an oxygen gas supply path further having a flow rate adjusting means connected to at least one of the gas supply path or the chamber, inert A test apparatus for a heat-resistant tubular member, comprising any one or more of gas supply paths .   6. The heat-resistant tubular member testing device according to claim 5, further comprising air compression means for supplying the pressurized air to a starting point of the excess air supply path.   Oxygen gas cylinder for supplying increased oxygen gas to the start point of the oxygen gas supply path and / or argon for supplying nitrogen gas cylinder or argon gas for supplying increased nitrogen gas to the start point of the inert gas supply path The heat-resistant tubular member testing apparatus according to claim 5 or 6, further comprising a gas cylinder.   The test apparatus is disposed in any one or more of an oxygen sensor, a control unit, the excess air supply path, the oxygen gas supply path, and the inert gas supply path disposed in the tubular portion of the heat-resistant tubular member. 8. The heat-resistant tubular member testing apparatus according to claim 5, further comprising a flow rate adjusting means provided.