JP7295655B2 - Oil quenching equipment and heat treatment equipment - Google Patents

Description

TECHNICAL FIELD The present invention relates to an oil quenching device for oil quenching a workpiece and a heat treatment facility equipped with the oil quenching device.

Quenching treatment is known as heat treatment for increasing the hardness of workpieces such as automobile parts and other machine parts. As one of such quenching treatment methods, there is oil quenching in which a workpiece heated to a high temperature is immersed in quenching oil to be rapidly cooled. When performing oil quenching, it is desirable not to reduce the cooling rate of the work during quenching in order to suppress distortion of the work after quenching. As a countermeasure for suppressing the decrease in the cooling rate, a method of stirring the quenching oil as described in Patent Document 1 is known.

Oil quenching using an oil quenching apparatus is generally performed by moving a workpiece to a space above quenching oil stored in an oil tank, and then lowering the workpiece and immersing it in the quenching oil. Patent Literature 2 discloses an oil quenching apparatus that conveys a workpiece to a lifting table attached to an oil tank. In an oil quenching apparatus such as that disclosed in Patent Document 2, it is common to immerse in quenching oil together with a work piece a conveying mechanism such as a guide roller attached to a lifting table when performing oil quenching.

JP 2012-207239 A JP-A-9-217114

When performing oil quenching, it is desirable to suppress variation in cooling rate for each part of the workpiece. In addition, when quenching a plurality of workpieces at the same time, in addition to suppressing variations in the cooling rate for each part of each workpiece, it is desirable to suppress variations in the cooling rate due to differences in the placement of each workpiece. .

When stirring the quenching oil, the greater the stirring force and the faster the flow rate of the quenching oil, the greater the variation in the flow rate in the oil bath, and the greater the variation in the cooling rate of the workpiece. In particular, as in Patent Document 2, in the case of a device structure in which the conveying mechanism such as guide rollers is immersed in the quenching oil together with the workpiece during quenching, there are many parts that obstruct the flow of the quenching oil, and the quenching oil hitting the workpiece increases. It is easy to cause fluctuations in the flow velocity of the water.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to suppress variations in the flow rate of quenching oil during quenching of a workpiece.

One aspect of the present invention for solving the above problems is an oil quenching apparatus comprising an oil tank, a work holder that holds a work in the oil tank, an elevating mechanism that lifts and lowers the work holder, and an outside of the oil tank. and an arm movement mechanism for moving the transfer arm, the work holder has a work placement section on which the work is placed, and the arm movement mechanism includes: the transfer arm between a standby position of the transfer arm positioned outside the oil tank and a delivery position positioned inside the oil tank at which the work is transferred between the transfer arm and the work holder; The transfer arm and the work placement section have shapes that do not overlap each other in plan view at the transfer position , and the work holder includes a transfer mechanism for transferring the work. It is characterized in that it is not provided .

According to another aspect of the present invention, there is provided a heat treatment facility comprising the oil quenching apparatus described above.

According to the present invention, it is possible to suppress variations in the flow rate of the quenching oil during quenching of the workpiece.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows schematic structure of the carburizing hardening equipment which concerns on one Embodiment of this invention. It is a figure which shows schematic structure of an oil quenching apparatus. FIG. 3 is a diagram showing a cross section taken along line AA in FIG. 2; FIG. 3 is a schematic diagram showing a BB cross section in FIG. 2; It is a figure which shows the state by which the workpiece|work was carried in to the oil tank. It is a figure which shows the state which the workpiece|work was immersed in quenching oil. FIG. 10 is a diagram showing a state in which the transfer arm has moved forward; It is the figure which looked at the state of FIG. 7 from the top. FIG. 10 is a diagram showing a state in which the work holder is lowered after the transfer arm advances; It is a figure which shows the state which a workpiece|work is carried out from an oil tank. It is a figure which shows an example of the oil draining method. FIG. 10 is a diagram showing a state in which the work holder is lowered after the transfer arm advances, according to another embodiment; 4A and 4B are diagrams showing examples of the shape of a transport arm; FIG. Figure 14 shows the transport arm of Figure 13 viewed from the front side of the transport arm; It is a figure which shows the flow velocity measurement position of the quenching oil in the flow velocity measurement test. It is a graph which shows the flow velocity of the quenching oil in a comparative example. 4 is a graph showing the flow rate of quenching oil in Examples.

An embodiment of the present invention will be described below with reference to the drawings. In the present specification and drawings, elements having substantially the same functional configuration are denoted by the same reference numerals, thereby omitting redundant description.

FIG. 1 is a diagram showing a schematic configuration of carburizing and quenching equipment 1, which is an example of heat treatment equipment. FIG. 1 shows only the surroundings of the carburizing device 10 and the oil quenching device 20 provided in the carburizing and quenching equipment 1 . The carburizing and quenching equipment 1 of the present embodiment is a so-called continuous treatment type heat treatment equipment, and the carburizing and quenching treatment is continuously performed on workpieces W to be heat-treated which are successively introduced. The carburizing and quenching equipment 1 of the present embodiment includes an entry side belt conveyor 2 as a transport mechanism for transporting the work W to the carburizing device 10, the carburizing device 10, the oil quenching device 20, and the work W that has been oil quenched. An output side belt conveyor 3 is arranged in order as a transport mechanism for transporting to the process. The carburizing device 10 includes a carburizing chamber 11 in which the work W is carburized, and a lifting table 12 on which the work W is placed. is provided. Further, the carburizing and quenching equipment 1 is provided with a pusher 5 penetrating through the side wall of the carburizing chamber 11 . The pusher 5 has a horizontally extendable structure so that the work W in the carburizing chamber 11 can be pushed into the oil quenching device 20 .

When the carburizing and quenching treatment is performed in the carburizing and quenching equipment 1, first, the work W conveyed by the entry-side belt conveyor 2 is placed on the lifting table 12 of the carburizing device 10 in a lowered state, and then , the platform 12 is lifted. The elevator table 12 also has a function of covering an opening (not shown) in the bottom wall of the carburizing chamber 11. As the elevator table 12 rises, the carburizing gas is supplied into the sealed carburizing chamber 11, thereby is carburized. After that, the door 4 is opened, and the work W is pushed out from the carburizing chamber 11 by the pusher 5 , thereby conveying the work W to the oil quenching device 20 . After the work W is quenched in oil, the work W is unloaded from the oil quenching device 20 and conveyed to the post-process by the exit-side belt conveyor 3 .

Although the carburizing and quenching equipment 1 of the present embodiment has a configuration in which the carburizing device 10 and the oil quenching device 20 are adjacent to each other through the door 4, the configuration of the carburizing and quenching equipment 1 is the same as that described in the present embodiment. Not limited. For example, the work W that has been carburized may be unloaded from the carburizing device 10 and transported to the oil quenching device 20 that is spaced apart from the carburizing device 10 . In addition, the carburizing and quenching equipment 1 of the present embodiment is equipment that assumes so-called gas carburizing, but the carburizing and quenching equipment 1 may be equipment in which other carburizing methods are performed. Furthermore, the carburizing and quenching equipment 1 is an example of a heat treatment equipment, and the heat treatment equipment is not particularly limited as long as it performs heat treatment that requires oil quenching.

The oil quenching device 20 of this embodiment will be described below.

As shown in FIGS. 2 to 4, the oil quenching apparatus 20 of this embodiment includes an oil tank 30 in which quenching oil is stored, a work holder 40 that holds a work W in the oil tank 30, and a work holder 40. A lift mechanism 50 for lifting, a transfer arm 60 arranged outside the oil tank 30 , and an arm movement mechanism 70 for moving the transfer arm 60 are provided.

As shown in FIG. 2, in the oil tank 30 of the present embodiment, the region in which the quenching oil is stored and the space above the quenching oil are not partitioned by a door or the like, and form one processing chamber. . A side wall of the oil tank 30 in the space above the quenching oil is formed with a work transfer port 30a, which is an opening for carrying out the work W. As shown in FIG. An opening/closing door 31 is provided outside the side wall of the oil tank 30 to cover the work transfer port 30a. As shown in FIG. 3, the oil tank 30 is equipped with a stirrer 80 that is driven by a drive source such as a motor. 32 are provided. The duct 32 covers the periphery of the stirring blades 81 of the stirrer 80 and extends along the inner surface of the oil tank 30 to a position where the work W is immersed in the quenching oil.

The work holder 40 of this embodiment includes an arm portion 41 configured to hold the work W from the side, and a pair of work pieces formed at the tip of the arm portion 41 and corresponding to a portion on which the work W is placed. and a mounting portion 42 . In this embodiment, one work W is placed on the work placement section 42, but a plurality of works W may be placed thereon. When there are a plurality of works W, for example, a plurality of works W are placed on a jig having a shape such as a tray or a basket, and the jig is placed on the work placement part 42, thereby indirectly A state in which the workpiece W is placed on 42 is reached.

As shown in FIG. 4, the work placement section 42 has a shape extending in the longitudinal direction of the transfer arm 60 (X direction in this embodiment). The pair of work mounting portions 42 are arranged in the Y direction of the work W (plan view) so as not to interfere with the transfer arm 60 when the transfer arm 60 moves forward and so as not to hinder the flow of quenching oil hitting the work W as much as possible. ) in the direction perpendicular to the longitudinal direction of the transfer arm 60 . In addition, the position where the work placement part 42 is provided is, for example, the shape of the oil tank 30, the shape of the arm part 41 of the work holder 40, the shape of the work W, the shape of the jig, and the position where the transfer arm 60 is arranged. It is changed accordingly.

The work holder 40 is configured to be elevated by an elevation mechanism 50 . The lifting mechanism 50 of the present embodiment employs a so-called elevator rack type mechanism. A hook 52 for fixing a chain 51 of the lifting mechanism 50 is attached to the work holder 40 . The work holder 40 is moved up and down by a driving source such as a motor of the lifting mechanism 50 by winding up or dispensing the chain 51 . In addition, the lifting mechanism 50 is not particularly limited as long as it is configured to lift and lower the work holder 40 .

As shown in FIGS. 2 and 4, the transport arm 60 of the present embodiment has a shape extending linearly, and is attached to the arm moving mechanism 70 with the upper surface of the transport arm 60 being horizontal. ing. It is preferable that the forward end portion of the transfer arm 60 is provided with a protrusion 61 protruding upward as in the present embodiment. By providing such a projecting portion 61, the projecting portion 61 can be hooked on the work W when the work W is carried out from the oil tank 30 by the transfer arm 60, and the work W can be easily carried out. can be done. The transfer arm 60 and the protrusion 61 may be separate parts, or may be integrally formed. Further, the position of the protrusion 61 in the longitudinal direction of the transfer arm 60 is not particularly limited, but it is preferably provided at the tip of the transfer arm 60 from the viewpoint of downsizing the oil tank 30 .

The arm moving mechanism 70 moves the transfer arm 60 between a waiting position P ₁ of the transfer arm 60 located outside the oil tank 30 and a transfer position P ₂ of the work W positioned inside the oil tank 30 . is configured to 2 and 4 show the transfer arm 60 at the standby position _P1 . The “transfer position” is a position where transfer of the work W between the transfer arm 60 and the work holder 40 is performed. The standby position _P1 of the transfer arm 60 can be changed as appropriate according to the shape of the oil tank 30, the shape of the transfer arm 60, the configuration of the arm moving mechanism 70, and the like. A position that does not interfere with the operation is appropriately selected in the area outside the oil tank 30 so that the arm 60 does not exist. The transfer position _P2 of the workpiece W can be appropriately changed according to the shape of the oil tank 30, the configuration of the workpiece holder 40, the configuration of the transfer arm 60, the configuration of the arm moving mechanism 70, and the like. A position within the inner region of the oil tank 30 that does not hinder the operation when moving forward to transfer W is appropriately selected.

The arm moving mechanism 70 of this embodiment employs a slide mechanism, and is configured to be able to move the slider 71 by a driving source such as a motor. The transport arm 60 is fixed to a slider 71 and advances or retreats along the longitudinal direction (the X direction in this embodiment) of the transport arm 60 as the slider 71 moves. Note that the arm moving mechanism 70 is not particularly limited as long as it has a configuration capable of moving the transport arm 60 .

As shown in FIG. 4, in the carburizing and quenching equipment 1 of the present embodiment, a pair of outlet belt conveyors 3 are provided on the outlet side of the oil tank 30, and the transfer arm 60 is connected to the pair of outlet belt conveyors 3. is placed between. Although one transport arm 60 is provided between the pair of output side belt conveyors 3 in this embodiment, a plurality of transport arms 60 may be provided. The conveying means for the work W after being carried out from the oil tank 30 is not limited to a belt-type conveyor, and any conveying means capable of conveying the work W placed on the conveying arm 60 to a post-process can be used. good.

Next, an oil quenching method using the oil quenching device 20 will be described.

First, as shown in FIG. 5, the work W is carried from the carburizing chamber 11 (FIG. 1) into the oil tank 30, and placed on the work holder 40 which is stopped in the space above the quenching oil. Subsequently, as shown in FIG. 6, the work holder 40 descends and the work W is immersed in the quenching oil. Oil quenching of the workpiece W is performed here. During oil quenching, the transfer arm 60 is stopped at the standby position _P1 .

Next, as shown in FIGS. 7 and 8, the work holder 40 is raised and the door 4 of the oil tank 30 is opened. After that, the transfer arm 60 moves forward from the waiting position _P1 to the transfer position _P2 so as to pass under the work W. As shown in FIG. At this time, as shown in FIG. 8, the transfer arm 60 and the work placement section 42 do not interfere with each other because the transfer arm 60 and the work placement section 42 do not overlap each other in plan view. When the transfer arm 60 is provided with the projecting portion 61 as in the present embodiment, the projecting portion 61 and the work W do not interfere with each other when the transfer arm 60 moves forward. It is necessary that the work holder 40 is elevated to a position higher than the upper end of the portion 61 .

Next, as shown in FIG. 9, the work holder 40 descends to a position where the bottom surface of the work W is lower than the upper ends of the projections 61. Then, as shown in FIG. In this embodiment, the height of the transfer arm 60 is lower than the height of the work placement section 42 , and the work W is placed on the work placement section 42 .

Next, as shown in FIG. 10, the transfer arm 60 is retracted from the transfer position _P2 to the standby position _P1 . At this time, the projecting portion 61 provided on the transfer arm 60 is caught by the work W, so that the work W passes through the work transfer port 30a while moving on the work placement portion 42. As shown in FIG. After that, the work W is transferred from the work holder 40 to the delivery side belt conveyor 3 by further retracting the transport arm 60 .

As described above, in the oil quenching apparatus 20 of the present embodiment, the work W can be carried out from the oil tank 30 by the transfer arm 60 arranged outside the oil tank 30 . The workpiece W is held in the oil tank 30 by placing the workpiece W on the workpiece mounting portion 42 extending in the longitudinal direction of the transfer arm 60 . Therefore, during hardening of the work W, the transfer arm 60 is in a state of being withdrawn from the oil tank 30 , and the work W is held only by the work holder 40 . Therefore, in the oil quenching apparatus 20 of the present embodiment, the number of parts obstructing the flow of the quenching oil is reduced compared to an apparatus having a structure in which the conveying mechanism such as guide rollers together with the work W are immersed in the quenching oil. As a result, it becomes easier to suppress the decrease in the flow velocity of the quenching oil, and the variation in the flow velocity can also be reduced.

Although one embodiment of the present invention has been described above, the present invention is not limited to such an example. It is obvious that a person skilled in the art can conceive various modifications or modifications within the scope of the technical idea described in the claims, and these are also within the technical scope of the present invention. be understood to belong to

For example, as shown in FIG. 11, when the workpiece W is placed on a grid-shaped jig J, when the workpiece W is unloaded from the oil tank 30, the projecting portion 61 provided on the transfer arm 60 is moved to the jig J. The carrier arm 60 may be repeatedly moved forward or backward by hooking the carrier arm 60 on the gap. As a result, the work W pulled up from the quenching oil can be drained of oil, and the amount of oil adhering to devices arranged outside the oil tank 30 can be reduced.

Further, in the above-described embodiment, when the work W was unloaded from the oil tank 30 as shown in FIG. Alternatively, the work holder 40 may be lowered so that the upper surface of the work placement section 42 is lower than the upper surface of the transfer arm 60 . When the work holder 40 is lowered in this manner, the work W is transferred from the work placement section 42 to the transfer arm 60, and the work W is placed on the transfer arm 60 instead of the work placement section 42. state. If the transfer arm 60 is retracted in this state, the bottom surface of the work W will not move while being in contact with the work placement section 42, so that the wear of the top surface of the work placement section 42 can be suppressed. Further, according to the method for transporting the work W as described above, the work W can be transported out of the oil tank 30 even if the transport arm 60 is not provided with the projecting portion 61 . Further, as shown in FIG. 12, by operating the transfer arm 60 and the work holder 40 in the reverse order of the procedure for transferring the work W from the work holder 40 to the transfer arm 60, the transfer arm 60 is transferred to the work holder. It is also possible to transfer the workpiece W to 40 . According to this transfer method, an untreated work W can also be carried into the oil tank 30 .

13 and 14, a groove 60a extending along the longitudinal direction of the transport arm 60 may be formed in the upper surface of the transport arm 60. As shown in FIGS. In the example of FIGS. 13 and 14, the groove 60a reaches the tip of the transfer arm 60, and the transfer arm 60 seen from the front side of the transfer arm 60 has a U shape with an opening on the upper surface. there is The depth of the groove 60 a increases as it approaches the tip of the transfer arm 60 , and the bottom surface of the groove 60 a slopes downward toward the tip of the transfer arm 60 . Further, when the projection 61 is provided at the tip of the transfer arm 60, the projection 61 is formed on the upper surface of the transfer arm 60 so that the groove 60a of the transfer arm 60 is not covered with the projection 61 as shown in FIG. placed nearby. In the transfer arm 60 in which the groove 60a is formed, when the workpiece W after quenching is placed on the transfer arm 60, the oil remaining in the work W flows into the groove 60a of the transfer arm 60 and flows along the inclined groove 60a. , flows to the tip of the transfer arm 60 . Then, the oil is discharged from the tip of the transfer arm 60 . That is, according to the transfer arm 60 having the groove 60a, it is possible to discharge the oil accumulated on the transfer arm 60. FIG.

As an example of the present invention, an oil quenching apparatus having a structure as shown in FIGS. 2 to 4 was used to conduct a quenching oil flow rate measurement test. As a comparative example, a similar flow velocity measurement test was performed using an oil quenching apparatus having a structure in which a conveying mechanism such as guide rollers together with the workpiece is immersed in the quenching oil. The flow velocity measurement test was carried out by changing the rotation speed of the stirrer stepwise and measuring the flow velocity at a plurality of measurement positions at each rotation speed. In this test, the flow velocity is measured by immersing a grid-shaped jig as shown in FIG. 15 in the quenching oil. This jig has a lower stage, a middle stage, and an upper stage where the workpieces are placed, and a plurality of workpieces are placed on each stage during quenching in actual operation. In this test, no workpiece was placed on the jig, and only the flow velocity was measured at the numbered locations in FIG.

As test results, Table 1 (comparative examples) and Table 2 (examples) below show the flow velocity measured at each measurement position, the average flow velocity, and the flow velocity variation (the difference between the maximum flow velocity and the minimum flow velocity). The graph corresponding to Table 1 is shown in FIG. 16, and the graph corresponding to Table 2 is shown in FIG.

According to the results of this test, when the rotation speed of the stirrer is the same, the average flow velocity of the quenching oil is higher in the example than in the comparative example. The reason for such a result is that in the oil quenching apparatus of the embodiment, since there is no conveying mechanism such as a guide roller under the jig, the quenching oil given a flow velocity easily hits the jig. It is thought that this is because Since there is a correlation between the flow rate of the quenching oil and the cooling rate of the workpiece, the oil quenching apparatus of the example can obtain a greater cooling capacity than the oil quenching apparatus of the comparative example. Therefore, it is possible to easily suppress a decrease in the cooling rate of the workpiece during quenching. Further, according to the results of this test, the flow velocity variation at each measurement position is smaller in the example. Therefore, according to the oil quenching apparatus of the embodiment, even when a plurality of works are placed on the jig, the variation in the cooling rate of each work can be reduced, and the quality variation of the works in the same lot can be reduced. can be suppressed.

INDUSTRIAL APPLICABILITY The present invention can be used for oil quenching of workpieces.

1 Carburizing and quenching equipment 2 Entrance belt conveyor 3 Exit belt conveyor 4 Door 5 Pusher 10 Carburizing device 11 Carburizing chamber 12 Elevating table 20 Oil quenching device 30 Oil tank 30a Work transfer port 31 Door 32 Duct 40 Work holder 41 Arm 42 Work Mounting unit 50 Lifting mechanism 51 Chain 52 Hook 60 Transfer arm 60a Groove 61 Protrusion 70 Arm moving mechanism 71 Slider 80 Stirrer 81 Stirring blade J Jig _P1 Standby position _P2 Work transfer position W Work

Claims (4)

an oil tank;
a work holder that holds a work in the oil tank;
a lifting mechanism for lifting and lowering the work holder;
a transfer arm arranged outside the oil tank;
an arm moving mechanism for moving the transport arm,
The work holder has a work placement section on which the work is placed,
The arm moving mechanism includes a standby position of the transfer arm located outside the oil tank, and a transfer position positioned inside the oil tank at which the transfer arm and the work holder transfer the work. having a structure for moving the transfer arm between
the transfer arm and the work placement section have shapes that do not overlap each other in a plan view at the delivery position ;
The oil quenching apparatus , wherein the work holder is not provided with a transport mechanism for transporting the work . 2. The oil quenching apparatus according to claim 1, wherein said transfer arm is provided with a protrusion extending upward. 3. The method according to claim 1, wherein a groove extending along the longitudinal direction of the transfer arm is formed in the upper surface of the transfer arm, and the depth of the groove increases toward the tip of the transfer arm. oil quenching equipment. A heat treatment facility for heat-treating a workpiece, comprising the oil quenching apparatus according to any one of claims 1 to 3.

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