JP2004340920A - Mechanical characteristic test apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mechanical characteristic test apparatus provided with a secure high-pressure vessel structure and conveniently replacing a holder such as a test piece and a support for attaching the test piece. <P>SOLUTION: The high-pressure vessel 2 comprises a cylindrical body 4 having an opening at one end and a lid 6 for openably and closably occluding the opening. A press frame 7 engages with and detaches from the high-pressure vessel from the outside and supports axial force applied to the lid 6 when a high-pressure gas is introduced into the high-pressure vessel. The quantity of deformation of the test piece 8 can be measured by an actuator 10 for applying a load to the test piece 8 fixed to the lid 6 through a rod 9 for penetrating the lid 6. The test piece 8 can be mounted and removed by detaching the press frame 7 and releasing the lid 6. The mechanical characteristic test apparatus can safely, easily and accurately measure a mechanical characteristic of a material such as a metal, a resin and a ceramic under a high-pressure gas ambience, and is useful for a test for grasping a mechanical characteristic change of the material under a high-pressure hydrogen gas ambience recently important to a fuel cell powered vehicle. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a mechanical property test apparatus for measuring mechanical properties such as tensile strength, compressive strength, bending strength, and tensile fatigue strength of materials such as metals, ceramics, and resins in a high-pressure gas atmosphere. In particular, the present invention relates to a mechanical property test apparatus which is excellent in safety and can easily exchange test pieces, jigs and the like.

  It is known that the strength characteristics of materials such as metals, ceramics, and resins change in a high-pressure gas atmosphere (environment). It is known that the ductility of a metal increases under a high pressure of several hundred MPa, and under a specific gas atmosphere, for example, under a high-pressure hydrogen gas atmosphere, a steel-based material may absorb hydrogen and become brittle. Are known.

  In particular, in recent years, the research and development of fuel cells using hydrogen as fuel has been activated, and the application to automobiles has been evolving from prototype vehicles to practical vehicles. In terms of practical use, hydrogen compressed to 35 MPa or 70 MPa has been used as fuel. Compressed hydrogen type which is used by filling in a cylinder. Hydrogen supplied from a high-pressure hydrogen cylinder mounted on an automobile is decompressed and used by a valve from a high-pressure state of 35 MPa or 70 MPa. However, since the material related to this valve is a steel-based material, a machine using high-pressure hydrogen is used. Changes in mechanical properties are very important from the viewpoint of ensuring safety, and accumulating experimental data on strength properties is urgently needed.

  On the other hand, in a high-pressure hydrogen gas atmosphere such as several tens to several hundreds of MPa, the test apparatus itself for measuring characteristics such as tensile strength is also exposed to such an atmosphere, so that not only the constituent materials but also the structural aspects are sufficient. There is no fact.

  In order to measure the mechanical properties of a material such as tensile strength, it is necessary to apply a load to a test piece having a specific size and shape and measure the amount of deformation at the same time. When this measurement is performed in a high-pressure gas atmosphere, a test piece is arranged inside a high-pressure vessel forming a high-pressure atmosphere, and a load applied to the test piece from outside the high-pressure vessel is separately applied.

  The technical problems in this case are (1) a structure in which a member (pull rod) for applying a load to the test piece is introduced into the high-pressure container without causing a gas leak while suppressing the frictional force and the like. (2) To reduce the influence of the error of the load value due to the pressure of the high-pressure gas acting on the pull rod and the frictional force of the seal ring.

  Japanese Patent Publication No. 54-10875 (Patent Document 1) proposes an atmosphere container for material testing by solving the above-mentioned problems. In this proposal, the latter problem (2) is particularly improved. As shown in FIG. 15, a structure 73 combining a piston 71 and a cylinder 72 is provided between a pull rod and a driving unit (actuator). The same pressure as the gas inside the high-pressure vessel 74 is introduced into the cylinder 72 by communicating with the structure portion 73 and the inside of the high-pressure vessel 74 to balance the load caused by the gas pressure, and the gas pressure introduced into the high-pressure vessel acts on the actuator. Not configured.

  Further, as a further problem, when the pressure becomes higher than 50 MPa, the structure of the high-pressure container also becomes a problem. That is, in a pressure range up to about 10 MPa, as a high-pressure container, a flange is formed at both ends of a metal cylinder, and a disk-shaped end plate is clamped with a gas seal ring and tightened with a plurality of bolts. Although a structure capable of containing the pressure is employed, if the same structure is used in a pressure range exceeding 50 MPa, the thickness of the cylindrical portion is increased, and the number of bolts for tightening the end plate becomes extremely large. For example, as shown in FIG. 1 of FIG. 16 of a publicly-known academic journal document (Rev. Sci. Instrum., Vol. 49, No. 1, January 1978) shown in FIG. The device is this example. Although no flange is formed in the cylindrical portion, the lid that fits into the opening of the thick cylindrical portion is formed so as to be fixed by the embedded bolt 75. Therefore, every time the high-pressure vessel is opened and closed in order to mount the test piece, it is necessary to loosen and remove all of the bolts 75, which complicates the work. It is necessary to consider how to make it. Further, in a screw structure such as the bolt 75, basically, a large stress concentration occurs in the screw portion, so that there is a fear of breakage, and there are many problems from the viewpoint of safety.

JP-B-54-10875 (page 2-3, FIG. 3) Rev. Sci. Instrum., Vol. 49, No. 1, January 1978 (Fig. 1)

  The present invention has been made in order to solve the above-mentioned problems of the related art, and a first object of the present invention is to provide a safer high-pressure vessel structure, a test piece, a support member for attaching the test piece, and the like. It is intended to provide a mechanical property testing device which can easily exchange jigs and the like. Even if such a high-pressure mechanical property test becomes possible, it is impossible to accurately measure the deformation amount of the test piece or the load acting on the test piece due to the high pressure affecting the sliding portion. It is concerned. Therefore, a second object is to provide a mechanical property test apparatus that has solved such a concern.

  In order to achieve the first object, a mechanical property test apparatus according to the present invention (claim 1) arranges a test piece in a high-pressure vessel into which a high-pressure gas is introduced, and applies a load to the test piece. In the mechanical characteristics test apparatus for measuring the deformation amount of the test piece, the high-pressure container is constituted by a cylindrical main body having an opening at at least one end, and a lid for opening and closing the opening. When the high-pressure gas is introduced into the high-pressure container, the axial force applied to the lid is supported by the press frame that is detachably attached to the high-pressure container from the outside, and the test piece is fixed to the lid. On the other hand, the amount of deformation of the test piece can be measured by an actuator that applies a load through a rod (pull rod) penetrating the lid, and the test piece is released by releasing the press frame and opening the lid. Wearing It is obtained by freely extraction.

  The mechanical characteristic test apparatus according to the present invention (claim 2) is the mechanical characteristic test apparatus according to claim 1, wherein the fluid pressure balance mechanism for reducing or eliminating the pressure applied to the rod by high-pressure gas is provided. It is provided on the rod.

  Further, a mechanical characteristic test apparatus according to the present invention (claim 3) is the mechanical characteristic test apparatus according to claim 1, which is movable integrally with the rod and has substantially the same cross-sectional area as the rod. A balance rod having an area is slidably penetrated in a portion of the main body facing the lid.

  Further, in order to achieve the second object, the mechanical property test apparatus according to the present invention (claim 4) is the mechanical property test apparatus according to any one of claims 1 to 3, wherein Four electric resistance wire type strain gauges constituting a Wheatstone bridge are affixed to a test piece fixing member for fixing a test piece to a lid portion in a located rod or a high pressure vessel.

  Further, the mechanical property test apparatus according to the present invention (Claim 5) is the mechanical property test apparatus according to any one of Claims 1 to 3, wherein a test piece is placed in a rod or a high pressure vessel located in a high pressure vessel. A load cell to which four electric resistance wire type strain gauges constituting a Wheatstone bridge are attached is arranged between a test piece fixing member fixed to the lid and the test piece.

  The mechanical characteristic test apparatus according to the present invention (claim 6) is the mechanical characteristic test apparatus according to claim 4 or 5, wherein the mechanical resistance test apparatus is a relative one of four electric resistance wire strain gauges constituting a Wheatstone bridge. One set of two strain gauges is attached in parallel with the direction in which the load acts, and the other set is attached in a direction perpendicular to the direction in which the load acts.

  The mechanical characteristic test apparatus according to the present invention (claim 7) is the mechanical characteristic test apparatus according to claim 6, wherein four electric resistance wire type strain gauges constituting a Wheatstone bridge are attached. Are formed in a columnar or cylindrical shape.

  According to the mechanical property test apparatus according to the present invention, under a high-pressure gas atmosphere, it becomes possible to perform the measurement of the mechanical properties of materials such as metals, resins, and ceramics safely, easily, and while maintaining high accuracy, Particularly, in recent years, it is extremely important to contribute to the progress of tests for grasping changes in mechanical properties of these materials under a high-pressure hydrogen gas atmosphere, which is becoming important in relation to fuel cell vehicles. Furthermore, the amount of deformation of the test piece and the load acting on the test piece can be accurately measured under high pressure.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of a mechanical property test apparatus according to the present invention, and FIG. 2 is a cross-sectional view of FIG. 1 when the high-pressure container is opened.

  The mechanical characteristic test apparatus 1 in this example includes a high-pressure container section 2 and a tester frame 3. The high-pressure container part 2 includes an inverted cup-shaped high-pressure container cylinder 4, a high-pressure container lower lid 6 fitted to the high-pressure container cylinder 4 via a seal ring 5 so as to be slidable in the axial direction, and these two members. 4 and 6, and a press frame 7 for supporting an axial load generated by the pressure inside. The high-pressure vessel lower lid 6 is connected and fixed to the tester frame 3, and has a structure in which a pull rod 9 for applying a test load to the test piece 8 penetrates a central portion thereof. An actuator 10 for generating a load applied to the pull rod 9 is fixed to the test machine frame 3, and a reaction force is supported by the test machine frame 3. In the present example, the actuator 10 that generates a load is constituted by a piston 11 and a cylinder 12, and is driven by a hydraulic pressure supplied from a hydraulic pressure source 13. The gas pressure during the test is supplied from a gas pressure source such as a compressor through a gas introduction hole A.

  The press frame 7 is composed of two groove-shaped frames that are symmetrical with respect to the central axis of the high-pressure vessel cylinder 4, and is used for removing and attaching the test piece 8 and fixing the test piece 8 inside the high-pressure vessel. When the tool 14 (support members 15, 16 and the like) is replaced, as shown in FIG. 2, it may be structured to be moved backward in parallel with the horizontal direction, or to have a double-sided opening structure (not shown). At this time, the high-pressure container cylinder 4 can be lifted up by an elevating actuator (not shown).

  As a result, the high-pressure vessel cylinder 4 and the high-pressure vessel lower lid 6 are fitted only through the seal ring 5, so that the high-pressure vessel cylinder 4 has a slight frictional force at the seal ring 4, It is not necessary to loosen bolts one by one as in the prior art shown in Patent Literature 1. After the press frame 7 is moved in parallel, the high-pressure vessel cylinder 4 can be easily lifted upward, and the test piece 8 In addition, since the support members 15 and 16 that fix the test piece 8 are exposed, the test piece 8 can be removed and attached very easily. In this example, the support member 15 is formed of a rectangular short-square pipe, and is connected to and fixed to the pull rod 9. The support member 16 is made of a U-shaped short material with a flange, and the flange side is connected to and fixed to the high-pressure vessel lower lid 6. The support member 15 and the support member 16 are arranged and fixed so as to intersect at right angles when viewed from above.

  Further, in this example, a gas pressure balance mechanism 17 is provided inside the high-pressure vessel lower lid 6. The gas pressure for gas pressure balance is supplied from a gas introduction hole B for balance, and the gas introduction hole B is supplied by piping so as to have the same pressure as the gas introduction hole A. This gas pressure balance mechanism 17 has substantially the same structure as that shown in the prior arts of Patent Document 1 and Non-Patent Document 1, and has a cylinder chamber 18 provided inside the high-pressure vessel lower lid 6, A piston 19 is provided in the middle of the pull rod 9, and seal rings 22, 23, 24 are provided between the piston 19 and the cylinder chamber 18 and between the pull rods 20, 21 on both sides of the piston 19 and the high-pressure vessel lower lid 2, respectively. However, if the high-pressure container structure according to the present invention has a structure in which high-pressure gas pressure acts on the pull rod 9, a screw structure in which stress concentration is likely to occur is used. Since it is not included, there is an advantage that the safety is excellent and the work of replacing the test piece 8 is easy. Also, when the gas used is hydrogen, there is a concern that the strength of the members in contact with the high-pressure hydrogen may be deteriorated or embrittled. However, in the high-pressure vessel structure according to the present invention, stress concentration such as screws that are sensitive to embrittlement may occur. Since there is no part and the axial load is supported by the press frame 7 which is not in contact with hydrogen, it goes without saying that it has the advantage of being extremely safe.

  FIG. 3 is an explanatory cross-sectional view of another embodiment of the mechanical property test device according to the present invention. The mechanical property test apparatus 25 in this example arranges an inverted cup-shaped heat insulating structure 26 along the inner peripheral surface of the inverted cup-shaped high-pressure container cylinder 4 and heats the heat insulating structure 26 inside the heat insulating structure 26. A test apparatus having substantially the same configuration as the mechanical property test apparatus 1 shown in FIGS. Although not shown, a lead wire for supplying electricity to the heating heater 27 may be introduced through a plug penetrating the inverted bottom of the high-pressure container cylinder 4.

  Conventionally, in order to perform a test under high temperature, a so-called external heating type heating method of heating the entire high pressure vessel from the outside of the high pressure vessel has been adopted (see Non-Patent Document 1). There is a temperature limit on the strength of the high-pressure vessel material, and large heating power is required to heat the entire high-pressure vessel, and the temperature must be raised to a predetermined temperature or cooled for a long time after the test. There were problems such as cost. According to the mechanical property test apparatus 25 of the present invention, only the test piece 8 and the jigs 14 inside the high-pressure container cylinder 4 need to be heated, so that even at a high temperature of 500 ° C. or higher, uniform heating and efficient heating are performed. It is possible.

  A heater 27 and a heat insulating structure 26 are arranged so as to cover the support member 15 inside the high-pressure vessel cylinder 4 from above, and both the heaters 26 and 27 are integrally fixed to the high-pressure vessel cylinder 4. With this structure, when the high-pressure container cylinder 4 is lifted upward when the test piece 8 or the jig 14 is attached or detached or replaced, the heater 27 and the heat insulating structure 26 are simultaneously pulled upward. The jig 14 can be easily exposed. Such an inverted cup-shaped heat insulating structure 26 is very excellent in heating under a high-pressure gas atmosphere in terms of securing uniform heat and suppressing heat radiation, and is very good in terms of control of test temperature. is there. In the case of this example, as a matter of course, when the high-pressure container cylinder 4 is pulled upward when the test piece 8 is mounted or removed, the heat insulating structure 26 and the heater 27 also rise together. There is no need to perform work such as disconnecting wires.

  In the mechanical property test apparatuses 1 and 25 described above, when the pressure is in the pressure range of 50 to 200 MPa, the high-pressure container cylinder 4 is not formed into an inverted cup shape but is closed by a simple cylinder and a seal ring member. It is recommended to use a combination structure with the container lid. By adopting such a structure, it is possible to avoid concentration of stress that occurs at the joint between the cylindrical portion and the bottom portion, which occurs when the high-pressure container cylinder 4 is a cylinder with a bottom. This is advantageous from the viewpoint of sex. An example will be described below.

  FIG. 4 is a front view showing a partial cross section of another embodiment of the mechanical property test apparatus according to the present invention, FIG. 5 is a side view showing a partial cross section of FIG. 4, and FIG. It is explanatory drawing which shows the state at the time of replacement. The examples of the mechanical characteristic test apparatus shown in FIGS. 4 to 6 are those in which the present invention is applied to a fatigue test apparatus having a drive mechanism of an electrohydraulic servo system in the test apparatus.

  The tester frame in this example is composed of a tester base 30 having two actuators 29 for generating a load applied to the pull rod 28, two columns 31 and a crosshead 32, and is fixed to the tester base 30 or the columns 31. A high-pressure vessel lower lid 34 is fixed to the stay 33. A pull rod 28 is arranged so as to penetrate the high-pressure container lower lid 34, and the lower end thereof is connected to an actuator 29 via a load cell 35 for measuring a load. A gas pressure balance mechanism 17 similar to that shown in the above example is built in the inside of the high-pressure vessel lower lid 34, and the upper end of the pull rod 28 is attached to a jig 14 for fixing a test piece inside the high-pressure vessel cylinder 36. Are combined.

  The high-pressure container section filled with the high-pressure gas includes a high-pressure container cylinder 36, a high-pressure container lower cover 34, a high-pressure container upper cover 37, and two window frame-type press frames 39 which open and close by moving right and left on the linear way 38. It consists of. The high-pressure vessel cylinder 36 and the high-pressure vessel upper lid 37 are connected by bolts or the like (not shown), and are usually configured to be integrally movable.

  In the state where the test is performed in a high-pressure gas atmosphere, as shown in FIG. 4, the window frame type press frame 39 is at a position supporting the gas pressure acting on the upper and lower lids 34 and 37. On the other hand, as shown in FIG. 6, when the test piece 8 and the jig 14 are attached and detached and replaced, the window frame type press frame 39 is moved right and left over the linear way 38 so that the high-pressure container cylinder 36 and the high-pressure container upper lid 37 are moved. Is pulled up using the crosshead 32 of the test apparatus. Reference numeral 40 denotes a cylinder that moves the crosshead 32 up and down.

  Thus, the fatigue test in a high-pressure gas atmosphere can be performed safely and easily by only slightly modifying a commercially available fatigue test apparatus.

  In the above-described embodiment in which the high-pressure vessel cylinder 36 is provided with the high-pressure vessel upper lid 37, the structure in which the test piece 8 is fixed to the high-pressure vessel lower lid 34 has been described as an example. It is good also as a structure hung from the upper lid 37 side. Although the press frame is a window frame-shaped press frame 39 in the above embodiment, it may be a press frame having a U-shaped partially open portion.

  By the way, the gas pressure balance mechanism 17 in the mechanical property test apparatus (1, 25, etc.) in the above-described embodiment has substantially the same structure as that shown in the prior art of Patent Document 1 and Non-Patent Document 1. Thus, while the cylinder chamber 18 is provided inside the high-pressure vessel lower cover 6 (34), the piston 19 is provided in the middle of the pull rod 9, and the pull rods 20, 21 between the piston 19 and the cylinder chamber 18 and on both sides of the piston 19 are provided. The configuration in which the seal rings 22, 23, and 24 and three seals are provided between the pressure vessel and the high-pressure vessel lower lid 2 has been described as an example. Normally, when the pull rod is directly pulled out of the high-pressure vessel into the atmosphere, the load due to gas pressure is applied as a load to the pull rod.However, in terms of structure, only one seal portion is required. When the seal structure includes a portion having a large diameter, the area of the sliding portion becomes three times or more, and the resistance force due to the frictional force increases accordingly. Further, as the pressure in the high-pressure container increases, the frictional force generated in this portion increases, and gas leakage easily occurs.

Therefore, as for the frictional force, it is preferable to use a sealing material such as PTFE (polytetrafluoroethylene: trade name of Dupont, Teflon) having a small coefficient of friction. When the pull rod is moved at a pressure of 100 MPa, if the diameter of the pull rod is 25 mm and the diameter of the piston is 35 mm, even if the width of the ring-shaped sliding portion of the seal ring is 3 mm, the three sliding portions have The area becomes about 8 cm ² and the frictional force becomes about 0.8 ton. Therefore, when the test is performed with a low load, the movement of the pull rod is of course not smooth due to the error, and even if a load is applied with a sine wave, for example, the load must be applied like a rectangular wave.

  In addition, if such a gas pressure balance mechanism 17 is incorporated into the upper lid or lower lid of a high-pressure container, the ease of replacement of these seal rings becomes a problem, and the lid on which the gas pressure balance mechanism 17 is mounted is , Resulting in a rather complicated structure. Further, in order to generate this balance force, it is necessary to provide a pipe or the like for applying the same gas pressure to the cylinder chamber 18 as in the high-pressure container.

  Hereinafter, an embodiment of a mechanical property testing device having a configuration in which the problem of the above-described gas pressure balance mechanism 17 is improved will be described.

  FIG. 7 is a cross-sectional view of another embodiment of the mechanical property test device according to the present invention. The mechanical property test device 41 shown in FIG. 7 has the gas pressure balance mechanism 17 inside the high-pressure vessel lower lid 6 while the mechanical property test device 1 shown in FIG. A through hole 43 is formed at the point and in the center of the inverted bottom portion 42 of the high-pressure container cylinder 4, and a balance rod 44 is provided on the upper surface of the support member 15. The balance rod 44 is attached to the through hole 43 by a seal ring 45. It has substantially the same configuration as the mechanical property test apparatus 1 shown in FIG. 1 except that the apparatus is slidably provided. Here, the cross-sectional area of the pull rod 9 and the cross-sectional area of the balance rod 44 are the same, that is, are constituted by rods having the same diameter.

  In the mechanical property test device 41 having the above-described configuration, a load that pushes the pull rod 9 downward is generated by the gas pressure inside the high-pressure container cylinder 4, and this load is applied to the balancing rod 44 having the same cross-sectional area. It is configured to act and balance the load that is to be pushed upward. That is, the support member 15 supports the load for pushing the pull rod 9 downward and the load for pushing the balance rod 44 upward, and the load due to the gas pressure is not transmitted to the actuator 10 below the pull rod 9.

  Therefore, according to the mechanical characteristic test apparatus 41 having the above-described configuration, the sealing member for the high-pressure gas related to the pull rod 9 includes the seal ring 23 that seals the pull rod 9 at a portion penetrating through the high-pressure container lower cover 6 and the balancing rod 44. There are only two seal rings 45 that are sealed by the through holes 43 in the inverted bottom portion 42 of the high-pressure container cylinder 4, and the diameter at the sealed portion can be accommodated so as to be twice the outer diameter of the pull rod.

  Incidentally, the frictional force generated at these seal portions is about 0.5 ton when the pressure is 100 MPa and the pull rods have the same diameter using the same seal material as in the above calculation example. Since the smaller the frictional force, the better, the frictional force is improved by about 40% as compared with the structure having the gas pressure balance mechanism 17 described above.

  Further, a further advantage of the mechanical property test apparatus 41 having the above-described configuration is that the probability of gas leakage is similarly reduced by reducing the number of seal portions, and further, the replacement of the seal ring is relatively easy. Can be raised. Also, needless to say, the mechanical property test apparatus of FIG. 1 has an advantage that the gas introduction hole B for balance is unnecessary, the number of high-pressure gas pipes is reduced, and the apparatus can be simplified. are doing.

  8 is a front view of another embodiment of the mechanical property test device according to the present invention, FIG. 9 is a side view of FIG. 8, and FIG. 10 is a cross-sectional view of FIG. The mechanical property test device 46 shown in FIGS. 8 to 10 has the gas pressure balance mechanism 17 in the mechanical property test device shown in FIGS. 17 and a high-pressure container upper lid 37, a through hole 47 is formed, and a balance rod 48 is provided on the upper surface of the support member 15. The balance rod 48 is slid into the through hole 47 via a seal ring 49. Except that it is movably provided, it has substantially the same configuration as the mechanical property test apparatus shown in FIGS. Here, the cross-sectional area of the pull rod 28 and the cross-sectional area of the balancing rod 48 are the same, that is, are constituted by rods having the same diameter.

  The pull rod 28 penetrates through the lower lid 34 of the high-pressure container, and the seal ring 23 is attached thereto. A balance rod 48 having the same diameter as the pull rod 28 penetrates the center of the high-pressure container upper lid 37, and is kept airtight by a seal ring 49 as in the case of the pull rod 28. Therefore, even with the mechanical property test apparatus having this configuration, the sealing member for the high-pressure gas related to the pull rod 28 includes the seal ring 23 for sealing the pull rod 28 at a portion penetrating the high-pressure container lower cover 34 and the balancing rod 48 for the high-pressure container. There are only two seal rings 49 to be sealed by the through holes 47 of the upper lid 37, and the diameter at the seal portion can be accommodated so as to be twice the outer diameter of the pull rod. Further, similarly to the mechanical property test device 41 having the above-described configuration, the load due to the gas pressure in the high-pressure container due to the number of sealing sites when measuring the mechanical properties of a material such as a metal, a resin, or a ceramic under a high-pressure gas atmosphere is measured. , 40% improvement, and the effect of reducing the number and area of sealing parts is expected to reduce the probability of occurrence of leakage and facilitate the replacement of seal rings. Measurement of characteristics becomes possible.

  In the mechanical characteristic test apparatus having the above-described configuration, when the high-pressure vessel is filled with the high-pressure gas, the high-pressure vessel lower lid 34 is fixed to the stay 33, so that the high-pressure vessel cylinder 36 and the high-pressure vessel upper lid 37 are connected to the press frame. This load is within the range of the load transmitted by the frictional force of the seal ring 49, and has no effect once the pressure at which the test is performed is reached.

  When the test piece 8 is detached or the jigs 14 are replaced, only the high-pressure vessel cylinder 36 and the high-pressure vessel upper lid 37 move upward, and the balance rod 48 is moved together with the support member 15 onto the high-pressure vessel lower lid 34. It is the shape left in. After the test piece 8 is mounted, the high-pressure vessel cylinder 36 and the high-pressure vessel upper lid 37 are lowered, so that the balance rod 48 is securely fitted into the through hole 47 in the central portion of the high-pressure vessel upper lid 37, and In order to prevent the seal ring 49 from being damaged, it is preferable that the upper end of the balance rod 48 be tapered.

  FIG. 11 is an explanatory cross-sectional view of another embodiment of the mechanical property test device according to the present invention. The mechanical property test apparatus 50 shown in FIG. 11 has a structure in which the test piece 8 inside the high-pressure vessel cylinder 4 and the high-pressure vessel lower cover 6 of the mechanical property test apparatus 1 shown in FIG. Other than the above-described configuration, the structure is changed to a structure including an embedded bolt 51 embedded in the high-pressure vessel lower lid 6, and a stay 54 of a test piece fixing jig 53 fixed by the embedded bolt 51 and a nut 52. This is a test apparatus having substantially the same configuration as the mechanical property test apparatus 1 shown in FIGS. 1 and 2. In this embodiment, furthermore, an electric resistance is provided on the outer peripheral surface of the pull rod 9 inside the high-pressure vessel cylinder 4 and the high-pressure vessel lower lid 6. A total of four linear strain gauges 55 to 58, two in each direction, are attached so as to form a Wheatstone bridge as shown in FIG. 12, and the load acting on the test piece 8 by detecting the amount of deformation of the pull rod 9 is detected. Measure It is configured to.

  In the mechanical characteristic test apparatus 50 having the above configuration, as shown in FIG. 12, two of the active gauges 55 and 56 out of the four electric resistance wire strain gauges 55 to 58 have the remaining two dummy gauges 57 in the load application direction. , 58 are attached at right angles to this to form a Wheatstone bridge. That is, since the pull rod 9 has a columnar shape, two sheets are attached to the surface of the pull rod 9 at positions opposite to each other by 180 degrees in the axial direction, and two sheets are attached in the circumferential direction at right angles thereto. Thereby, the strain uniformly generated in the four electric resistance wire strain gauges 55 to 58, that is, the influence of the temperature change, the effect of the hydrostatic pressure, and the material change that changes the electric characteristics of the resistance wire of the strain gauge. It is possible to cancel the influence (the influence due to hydrogen or the like) so that the output voltage is not affected. It is needless to say that when bending loads are generated on the pull rod 9 by attaching the axially active gauges 55 and 56 to the surface on the opposite side by 180 degrees, the influence of this bending can be canceled. In FIG. 12, reference numeral 59 denotes a voltage application power supply, and 60 denotes a voltmeter.

  Therefore, according to the mechanical property test apparatus 50 having the above configuration, the concerns and problems described below are eliminated, and the load acting on the test piece 8 can be accurately measured under high pressure.

  That is, in an actual testing machine, for example, a load of 10 to 100 kN is applied to the test piece 8. However, when the diameter of the pull rod 9 is 30 mm and the fluid pressure is 100 MPa, the load applied to the pull rod 9 by the fluid pressure is 70 kN. As a result, a situation where the load becomes larger than the test load occurs, and there is a concern that significant measurement becomes difficult. In such a case, the gas pressure balance mechanism 17 described above is very useful as a structure for canceling the load due to the fluid pressure. However, it is necessary that the pull rod 9 be provided with a structure such that the high-pressure fluid does not leak by the seal rings 23, 22, and 24. The same pressure as the high-pressure fluid pressure acts on these seal rings 22 to 24. Due to this pressure, a frictional force is generated between the surfaces of the seal rings 22 to 24 and the pull rod 9 according to the friction coefficient and the contact area on the surfaces, and the friction is generated only by the gas pressure balance mechanism 17. It is feared that the effects of force cannot be avoided. The effect of this frictional force is as follows when the contact width between the seal rings 22 to 24 and the pull rod 9 is 5 mm with the pull rod 9 having the above-mentioned dimensions (diameter: 30 mm). Even when a material is used, the fluid pressure becomes about 19 kN when the fluid pressure becomes 100 MPa. To perform the test, the actuator needs to have an ability to generate an extra load corresponding to the friction load. In addition to a size that cannot be ignored, a test using a load control method, for example, a fatigue test may not be performed in practice. However, according to the mechanical property test apparatus 50 having the above configuration, the load acting on the test piece 8 can be accurately measured under high pressure while avoiding these concerns and problems. This also makes it possible to perform accurate load control using the load signal acting on the test piece 8.

  In the embodiment shown in FIG. 11, the case where the electric resistance wire strain gauges 55 to 58 are attached so as to form a Wheatstone bridge on the outer peripheral surface of the pull rod 9 has been described, but the present invention is not limited to this embodiment. Instead, for example, as shown in FIG. 13, a load cell (test piece fixture) 61 having a structure for fixing the test piece 8 and having electric resistance wire strain gauges 55 to 58 adhered to the outer surface so as to form a Wheatstone bridge. May be provided between the test piece 8 and the stay 54 (or between the test piece 8 and the pull rod 9). With the mechanical characteristic test device 62 configured as described above, the same operation and effect as those of the mechanical characteristic test device 50 configured as described above can be obtained. Note that the shape of the load cell 61 is preferably a columnar shape, but is not necessarily limited to a columnar shape. In order to improve the response of the load cell to a load, the load cell 61 may be formed in a cylindrical shape so as to reduce the cross-sectional area. Is also included.

  FIG. 14 is an explanatory cross-sectional view of another embodiment of the mechanical property test device according to the present invention. The mechanical property test apparatus 63 shown in FIG. 14 has a structure for fixing the test piece 8 inside the high-pressure vessel cylinder 36, the high-pressure vessel lower lid 34, and the high-pressure vessel upper lid 37 of the mechanical property test apparatus 46 shown in FIG. The structure is changed to a structure comprising an embedded bolt 64 embedded in the high-pressure container lower lid 34, a test piece fixing jig-integrated stay 66 fixed by the embedded bolt 64 and a set bolt 65, and further a high-pressure container 8 except that the support member 67 provided at the tip of the balancing rod 48 of the upper lid 37 is provided with a load cell 68 also serving as a test piece fixing jig. The test apparatus has substantially the same configuration. In the present embodiment, a Wheatstone bridge as shown in FIG. The load acting on the test piece 8 attached between the stay 66 attached to the test piece fixing jig and the load cell 68 also serving as the test piece fixing jig is measured. Is configured. The load cell 68 which also serves as a test piece fixing jig is an example of the above-mentioned cylindrical load cell.

  According to the mechanical characteristic test device 63 having the above configuration, the same operation and effect as the mechanical characteristic test device 50, that is, the frictional force between the balance rod 48 and the seal ring 49 and the pull rod 28 and the seal ring By avoiding the influence of the frictional force between the test piece 23 and the test piece 8, the amount of deformation of the test piece 8 and the load acting on the test piece 8 can be accurately measured under high pressure.

It is a sectional view of a mechanical property test device concerning the present invention. FIG. 2 is a sectional view when the high-pressure container in FIG. 1 is opened. It is sectional explanatory drawing of another embodiment of the mechanical-characteristic test apparatus which concerns on this invention. It is a front view showing a partial section of another embodiment of a mechanical property test device concerning the present invention. FIG. 5 is a side view showing a partial cross section of FIG. 4. FIG. 5 is an explanatory diagram illustrating a state when a test piece is replaced in the mechanical property test device in FIG. 4. It is sectional drawing of another embodiment of the mechanical-characteristic test apparatus which concerns on this invention. It is a front view of another embodiment of the mechanical property test device concerning the present invention. FIG. 9 is a side view of FIG. 8. It is XX sectional drawing of FIG. It is sectional explanatory drawing of another embodiment of the mechanical-characteristic test apparatus which concerns on this invention. It is an explanatory view of a Wheatstone bridge according to the present invention. It is sectional explanatory drawing of another embodiment of the mechanical-characteristic test apparatus which concerns on this invention. It is sectional explanatory drawing of another embodiment of the mechanical-characteristic test apparatus which concerns on this invention. It is sectional drawing of the atmosphere container for material tests in the conventional mechanical property test apparatus. It is sectional drawing of the atmosphere container for material tests in the conventional mechanical property test apparatus.

Explanation of reference numerals

1: Mechanical property testing device 2: High pressure vessel part 3: Testing machine frame 4: High pressure vessel cylinder 5: Seal ring 6: High pressure vessel lower lid 7: Press frame 8: Test piece 9: Pull rod 10: Actuator 11: Piston 12: Cylinder 13: Hydraulic source 14: Jig 15, 16: Support member 17: Gas pressure balance mechanism 18: Cylinder chamber 19: Piston 20, 21: Pull rod 22, 23, 24: Seal ring 25: Mechanical property test device 26: Heat insulation Structure 27: Heater for heating 28: Pull rod 29: Actuator 30: Testing machine base 31: Column 32: Cross head 33: Stay 34: High pressure vessel lower lid 35: Load cell 36: High pressure vessel cylinder 37: High pressure vessel upper lid 38: Linear Way 39: Window frame type press frame 40: Cylinder 41: Mechanical property test device 42: Bottom 43: Through hole 44: Balancing rod 45: Seal ring 46: Mechanical characteristic test device 47: Through hole 48: Balancing rod 49: Seal ring 50: Mechanical characteristic test device 51: Embedded bolt 52: Nut 53: Test piece fixing Jig 54: Stay 55-58: Electric resistance wire strain gauge 59: Voltage applying power supply 60: Voltmeter 61: Load cell 62: Mechanical property test device 63: Mechanical property test device 64: Embedded bolt 65: Set bolt 66: Test piece Fixing jig integrated stay 67: Support member 68: Load cell that also serves as a test piece fixing jig A, B: Gas introduction holes

Claims (7)

  In a mechanical property test apparatus for arranging a test piece in a high-pressure vessel into which a high-pressure gas has been introduced and applying a load to the test piece to measure an amount of deformation of the test piece, the high-pressure vessel has an opening at least at one end. And a lid for closing the opening so as to be openable and closable. When a high-pressure gas is introduced into the high-pressure container, an axial force applied to the lid is applied to the high-pressure container. The deformation amount of the test piece can be measured by an actuator portion that is supported by a press frame that is detachable from one side and applies a load to a test piece fixed to the lid portion through a rod that penetrates the lid portion. A mechanical property test apparatus characterized in that a test piece can be mounted and removed by detaching the press frame and opening the lid.   The mechanical characteristic testing device according to claim 1, wherein a fluid pressure balance mechanism that reduces or eliminates the pressure applied to the rod by high-pressure gas is provided on the rod.   A balance rod which is movable integrally with the rod and has substantially the same area as a cross-sectional area of the rod is slidably penetrated in a portion of the main body facing the lid. The mechanical characteristic test apparatus according to claim 1, wherein   The mechanical property test apparatus according to any one of claims 1 to 3, wherein a Wheatstone bridge is formed on a rod positioned in the high-pressure vessel or on a test piece fixing member for fixing the test piece to the lid in the high-pressure vessel. A mechanical property testing device, wherein an electric resistance wire type strain gauge is attached.   The mechanical property test apparatus according to any one of claims 1 to 3, wherein a Wheatstone is provided between the test piece and a rod located in the high-pressure vessel or a test piece fixing member for fixing the test piece to the lid in the high-pressure vessel. A mechanical characteristic test apparatus, comprising: a load cell to which four electric resistance wire type strain gauges constituting a bridge are attached.   Of the four electric resistance wire strain gauges constituting the Wheatstone bridge, one set of two opposing strain gauges is parallel to the direction in which the load acts, and the other set is perpendicular to the direction in which the load acts. The mechanical property test device according to claim 4, wherein the device is attached in a direction. 7. The mechanical property test apparatus according to claim 6, wherein a portion of the Wheatstone bridge to which the four resistance wire strain gauges are attached is formed in a columnar or cylindrical shape.

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