JP2010274284A - Device and method for evaluating durability of shearing press - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device capable of easily and correctly reproducing the actual shearing of a shearing press, and highly precisely and appropriately evaluating its durability, and to provide a method thereof. <P>SOLUTION: The device is for previously comprehending the frequency of shearing, at which the sliding part in a shearing press exceeds a wear limit or cracking or deforming occurs, and for correctly and easily reproducing the shearing in a repeated manner in order to evaluate the durability thereof. The device is provided with: a cylinder 1 reproducing the direction and size of the force generated in the shearing press when the object to be worked is subjected to shearing; a switching valve 2 switching the direction and size of the force reproduced by the cylinder 1; and an operating means 3 performing control in such a manner that the operating position of the switching valve 2 is controlled in accordance with the stroke of the shearing press. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a durability evaluation apparatus for a shear press and a durability evaluation method thereof. More specifically, for example, an apparatus for evaluating the durability of a shear press by repeatedly reproducing punching with a shear die such as a punch and a die. And its method.

  In a shearing press, when a workpiece is sheared, it is large for each shot at the moment when the shearing die contacts the workpiece and passes through the workpiece (that is, when the workpiece is sheared). Repeated reaction force. And if such reaction force is repeatedly received, the durability of the sliding part of the shear press will be worn or cracked, resulting in a decrease in durability. Processing cannot be continued. Therefore, the durability of the shear press is evaluated in advance, and maintenance time such as replacement of the sliding part is set.

  As a conventional technique for preliminarily evaluating the durability of such a shear press, as shown in FIG. 8, an elastic body 1 ′ made of a spring, urethane, a gas cylinder, or the like is attached to the shear press, and the shear force is reduced. The force was simulated by an elastic body. As a shearing press, a punching press provided with a cam unit 4 for punching in a direction different from the press direction is generally known (see, for example, Patent Document 1). In FIG. It is shown. The cam unit 4 shown in FIG. 8 includes a machining cam 40 provided on the lower die plate 6 and a cam driver 41 provided on the upper die plate 7. One shear die such as a punch is provided on the machining cam 40. And attach the other shearing die such as a die on the lower die plate 6 so as to correspond to the punch. The processing cam 40 is supported by the slide mechanism 5 provided on the lower mold plate 6. Slide plates 41 a and 40 a are provided on the sliding surfaces of the cam driver 41 and the machining cam 40, respectively. The slide mechanism 5 includes a support plate 50 that slidably supports the machining cam 40, a guide bar 52 that is inserted into the guide hole 45 of the machining cam 40 and guides its forward and backward movement, and an addition by the cam driver 41. A return means 53 made of an elastic body for returning the machining cam 40 when the pressure is released is provided. In the cam unit 4 configured in this way, the machining cam 40 is moved forward in the left direction in FIG. 8 when pressed by the cam driver 41, and is returned by the return means 53 when the pressure applied by the cam driver 41 is released. It is moved backward to the right in FIG.

  When the processing cam 40 moves forward and backward, the cam driver 41 and the slide plates 41a and 40a of the processing cam 40, the surface where the support plate 50 of the slide mechanism 5 contacts the processing cam 40, the guide bar 52 of the slide mechanism 5 and the processing. The guide holes 45 of the cam 40 slide with each other. If these sliding parts exceed the wear limit as the number of shearing processes (the number of shots) progresses, the shearing process cannot be performed with high accuracy. When the processing cam 40 is pressurized by the cam driver 41, an impact load is applied to the slide plates 41a and 40a, or the cam driver 41 and the processing cam 40, the support plate 50 of the slide mechanism 5, the guide bar 52, and the like. Even when these portions receive impact loads and cracks and deformations occur with the progress of the number of shearing operations, the shearing processing cannot be performed with high accuracy. Therefore, it is necessary to reproduce the shearing process accurately and easily, to grasp the number of times the sliding part exceeds the wear limit, cracking or deformation in advance and evaluate the durability of the shear press. Is done.

  In addition, as a technique for evaluating the durability of the shear press in advance, it is conceivable to evaluate the durability by actually repeatedly shearing the workpiece or its sample piece with the shear press.

Japanese Patent Laid-Open No. 10-235437

  As shown in FIG. 8, when the elastic body 1 ′ is attached to the shear press, the elastic body 1 ′ simply reproduces only the reaction force during shearing in a pseudo manner. Here, as shown in FIG. 8, particularly when punching is performed with the cam unit 4, the force generated in the shear press causes the punching die such as a punch to punch (shear) the workpiece. ) In addition to the momentary reaction force, the punching die is hardly subjected to the reaction force when it is moved toward the bottom dead center after punching the workpiece. There is a return resistance or the like generated by sliding with the workpiece when being pulled out from the workpiece, and by sliding the processing cam 40 on the support plate 50. That is, during the shearing process, in addition to the reaction force generated at the moment of shearing, another force having a magnitude different from the reaction force is generated, and the direction in which the force is generated is different. However, in the conventional technique shown in FIG. 8, only the reaction force at the moment when the shearing die shears the workpiece is merely reproduced. Therefore, in the prior art shown in FIG. 8, it was impossible to accurately reproduce the actual shearing process and accurately evaluate its durability. Further, as shown in FIG. 8, the elastic body 1 ′ attached to the shear press can only reproduce a constant reaction force at the time of shearing, and varies depending on shear conditions such as the thickness and material of the workpiece. Since the force cannot be reproduced, it is necessary to prepare and replace the elastic body 1 ′ in accordance with the shearing conditions, which causes problems such as cost and labor for replacement.

  Moreover, when evaluating by actually repeatedly punching a workpiece or its sample piece with a shear press as described above, there was a problem that the workpiece or its sample piece was expensive and expensive. . In general, a workpiece or a sample piece thereof is formed into a continuous band and wound in a coil shape, and the workpiece or the sample piece wound in this coil shape is sequentially pulled out and actually punched. To do. Therefore, especially when the punching press is provided with a cam unit as shown in the figure, the punching direction is different from the pressing direction. It is difficult to pull out sequentially and actually perform punching. Therefore, it was impossible to reproduce the actual shearing process and evaluate its durability.

  The present invention has been made in view of the above-described problems, and provides an apparatus and method that can easily and accurately reproduce actual shearing and accurately evaluate its durability accurately. Objective.

The invention relating to the durability evaluation apparatus for a shear press according to claim 1 is an apparatus for evaluating the durability of the shear press in order to achieve the above object, and is a shear press for shearing a workpiece. Reproduction means capable of reproducing the direction and magnitude of the generated force, switching means for switching the direction and magnitude of the force reproduced by the reproduction means, and control means for controlling the switching means according to the stroke of the shear press; It is characterized by having.
The invention relating to the durability evaluation method for a shear press according to claim 2 is a method for evaluating the durability of the shear press in order to achieve the above object, and is a shear press for shearing a workpiece. A reproducible means capable of reproducing the direction and magnitude of the generated force is attached, and the direction and magnitude of the force generated in the shearing press when the workpiece is sheared according to the stroke of the shearing press according to the stroke of the shearing press. It is characterized by being reproduced while switching.

According to the first aspect of the present invention, when the reproducing means, the switching means, and the control means are attached to the shear press, and the molds facing each other are driven relatively close by driving the shear press, the control means switches according to the stroke. The means are switched, and the reproducing means reproduces the direction and magnitude of the force generated in the shear press when shearing the workpiece. Therefore, it is possible to provide an apparatus that can easily and accurately reproduce an actual shearing process and accurately evaluate the durability accurately.
According to the invention of claim 2, the reproducing means is attached to the shear press, and the direction and magnitude of the force generated in the shear press when the workpiece is sheared by the reproducing means according to the stroke of the shear press is switched. However, by reproducing the actual shearing process, it is possible to provide a method capable of reproducing the actual shearing process easily and accurately and appropriately evaluating the durability accurately.

(Aspect of the Invention)
In the following, the invention that is claimed to be claimable in the present application (hereinafter sometimes referred to as “claimable invention”. The claimable invention is at least the “present invention” to the invention described in the claims. Some aspects of the present invention, including subordinate concept inventions of the present invention, superordinate concepts of the present invention, and inventions of other concepts) will be exemplified and described. As with the claims, each aspect is divided into sections, each section is numbered, and is described in a form that cites the numbers of other sections as necessary. This is for the purpose of facilitating the understanding of the claimable invention, and is not intended to limit the combinations of the constituent elements constituting the claimable invention to those described in the following sections. In other words, the claimable invention should be construed in consideration of the description accompanying each section, the description of the embodiments, etc., and as long as the interpretation is followed, another aspect is added to the form of each section. In addition, an aspect in which constituent elements are deleted from the aspect of each item can be an aspect of the claimable invention. In each of the following items, item (1) corresponds to claim 1, and item (4) corresponds to claim 2.

(1) An apparatus for evaluating the durability of a shear press,
Reproduction means capable of reproducing the direction and magnitude of the force generated in the shear press when the workpiece is sheared;
Switching means for switching the direction and magnitude of the force reproduced by the reproduction means;
And a control means for controlling the switching means according to the stroke of the shear press.

  In the invention of (1), when the reproduction means, the switching means and the control means are attached to the shear press and the shearing press is driven to bring the molds facing each other relatively close together, the switching means is controlled by the control means according to the stroke. And the reproduction means reproduces the direction and magnitude of the force actually generated in the shearing press when the workpiece is sheared. Therefore, the actual shearing process can be reproduced easily and accurately, and its durability can be evaluated appropriately with high accuracy.

(2) The reproduction means comprises a cylinder,
The switching means comprises a switching valve for supplying or discharging a working fluid of a predetermined pressure to the cylinder chamber of the cylinder;
The apparatus for evaluating durability of a shear press according to item (1), wherein the control means comprises operation means for operating an operating position of the switching valve in accordance with a stroke of the shear press.

  In the invention of the item (2), in the invention described in the item (1), when the shearing press is driven to bring the dies facing each other relatively close to each other, the operating means changes the operating position of the switching valve according to the stroke. The direction of the force actually generated in the shearing press when the workpiece is sheared by supplying a working fluid at a predetermined pressure to the cylinder chamber of the cylinder or discharging the working fluid from the cylinder chamber according to the switching operation. Reproducing the size is realized.

(3) In the case where the shear press includes a cam unit having a cam driver and a processing cam that moves in a direction different from the press direction by being pressed by the cam driver,
The piston rod of the cylinder is coupled to the machining cam of the cam unit;
The apparatus for evaluating durability of a shear press according to item (2), characterized in that compressed gas is supplied to a cylinder chamber for driving the piston rod of the cylinder to retract.

  In the invention of (3), in the invention of (2), the shear press has a cam driver and a machining cam that moves in a direction different from the press direction when pressed by the cam driver. In the case where the unit is provided, the piston rod of the cylinder is coupled to the machining cam of the cam unit, and compressed gas is supplied to the cylinder chamber for driving the piston rod of the cylinder to retract. Thus, it is possible to reproduce the return resistance generated in the machining cam when the molds facing each other from the bottom dead center are relatively separated from each other, and therefore, actually occur in the shear press when the workpiece is sheared. It is realized to reproduce the direction and magnitude of force more accurately.

(4) A method for evaluating the durability of a shear press,
Attach a reproduction means that can reproduce the direction and magnitude of the force generated in the shear press when shearing the workpiece,
A method for evaluating the durability of a shear press, wherein the direction is reproduced while switching the direction and magnitude of the force generated in the shear press when the workpiece is sheared by the reproducing means according to the stroke of the shear press.

  In the invention of the item (4), the reproduction means is attached to the shear press, and the direction and the magnitude of the force generated in the shear press when shearing the workpiece by the reproduction means according to the stroke of the shear press is changed. By reproducing, the actual shearing process can be reproduced easily and accurately, and the durability can be evaluated appropriately with high accuracy.

It is the conceptual diagram shown in order to demonstrate one Embodiment of the durability evaluation apparatus of the shear press of this invention. It is the conceptual diagram shown in order to demonstrate the structure of the switching mechanism which supplies or discharges a working fluid to the double acting cylinder shown in FIG. 1, and the cam mechanism which operates the operating position of this switching valve. A graph showing the direction and magnitude of the force generated in the shear press when the workpiece is actually sheared, and the force generated in the shear press according to the stroke of the shear press is controlled by the control means by the switching means. It is explanatory drawing which shows the state reproduced by the reproduction means, and is explanatory drawing of the state before a shear type | mold contacts the workpiece, and the state before a control means contacts a switching means. FIG. 4 is a graph showing the magnitude and direction of the force generated at the moment when the shearing die abuts on the workpiece and performs shearing from the state of FIG. 3, and an explanatory diagram of the state in which the control means is in contact with the switching means. . FIG. 5 is a graph showing the magnitude and direction of the force when the shearing die penetrates the workpiece from the state of FIG. 4, and an explanatory diagram of the state where the control means penetrates the switching means. FIG. 6 is a graph showing the magnitude and direction of the force generated when the shearing die is pulled out of the workpiece past the bottom dead center from the state of FIG. 5 and an explanatory diagram of the state before the control means leaves the switching means. is there. FIG. 7 is a graph showing the magnitude and direction of the force when the shearing mold is separated from the workpiece from the state of FIG. 6, and an explanatory diagram of the state where the control means is completely separated from the switching means. It is the conceptual diagram shown in order to demonstrate the prior art which attaches an elastic body and reproduces | regenerates the reaction force at the time of shearing in the case where a shear press is provided with the cam unit.

First, one embodiment of the durability evaluation of the shear press of the present invention will be described in detail based on FIG. 1 and FIG. In the drawings, the same reference numerals denote the same or corresponding parts.
The apparatus of the present invention is generally for evaluating the durability of a shear press, and is a cylinder 1 that reproduces the direction and magnitude of a force generated in the shear press when shearing a workpiece, A switching valve 2 that switches the direction and magnitude of the force reproduced by the cylinder 1 and an operating means 3 that operates to control the operating position of the switching valve 2 according to the stroke of the shear press are provided.

  The shear press in the embodiment shown in FIG. 1 includes a lower mold plate 6 and an upper mold plate 7 that moves up and down with respect to the lower mold plate 6. The cam unit 4 is provided for moving the shearing die in a direction different from the pressing direction. The cam unit 4 includes a cam driver 41 fixed to the upper mold plate 7 and a machining cam 40 that is movably provided on the lower mold plate 6. When normal shearing is actually performed, one shearing die such as a punch is attached to the processing cam 40, and the other shearing die such as a die is attached to the lower die plate 6 so as to correspond to the punch. The processing cam 40 is supported by the slide mechanism 5 provided on the lower mold plate 6. Slide plates 41 a and 40 a are provided on the sliding surfaces of the cam driver 41 and the machining cam 40, respectively.

  The slide mechanism 5 includes a support plate 50 that slidably supports the processing cam 40, brackets 51, 51 provided at both end edges of the support plate 50, and a processing cam 40 that is installed between the brackets 51, 51. And a guide bar 52 that is inserted into the guide hole 45 and guides its forward movement and backward movement. Further, the slide mechanism 5 moves the machining cam 40 moved forward (moved to the left in FIG. 1) by the contact of the cam driver 41, when the cam driver 41 releases the pressure (FIG. 1). , A return means 53 made of an elastic body such as a spring or urethane is provided.

  In the shear press configured as described above, when the cam driver 41 pressurizes the machining cam 40 by the downward movement of the upper mold plate 7, the machining cam 40 is moved forward to the left in FIG. When the press of the machining cam 40 by the cam driver 41 is released by the movement, the machining cam 40 is moved backward to the right in FIG.

  The slide plate 41a, 40a of the cam driver 41 and the machining cam 40, the surface where the support plate 50 of the slide mechanism 5 contacts the machining cam 40, the guide bar 52 of the slide mechanism 5 and the guide hole 45 of the machining cam 40 slide relative to each other. If the sliding parts are worn and the sliding parts exceed the wear limit as the number of shearing processes (the number of shots) increases, the shearing process cannot be performed accurately. Also, the cam driver 41 and the slide plates 41a and 40a of the processing cam 40, or the cam driver 41 and the processing cam 40, the support plate 50 and the guide bar 52 of the slide mechanism 5 are cracked or broken as the number of shearing operations increases. Even when deformation occurs, it becomes impossible to perform shearing with high accuracy. In the present invention, the shearing process is repeated accurately and easily, and the durability of the shear press is evaluated by grasping in advance the number of shearing processes where the sliding part exceeds the wear limit or cracks or deformation occurs. is there.

  The cylinder 1 is attached to the lower die plate 6 in place of the other shearing die such as a die for actually performing normal shearing. A portion of the processing cam 40 to which one shearing die, such as a punch for actually performing normal shearing processing, is fastened to the tip of the piston rod 10 of the cylinder 1 by a fastening portion 46. A pipe 11 for supplying / discharging a working fluid such as oil is connected to the cylinder chamber 1 </ b> A on the anti-piston rod side of the cylinder 1. Also, the piston rod side cylinder chamber 1B of the cylinder 1 is connected to a supply means 13 such as an air compressor for supplying a gas compressed to a predetermined pressure, such as air, through a pipe line 12. The gas supplied to the piston rod side cylinder chamber 1B is not limited to compressed air, and for example, an inert gas such as nitrogen gas can be employed.

  As shown in FIG. 2, the switching valve 2 is connected to the pipe line 11 of the cylinder chamber 1 </ b> A on the anti-piston rod side of the cylinder 1. In the case of this embodiment, the switching valve 2 is supported by a column 6 a provided on the lower mold plate 6. The switching valve 2 in the embodiment shown in FIG. 2 includes a sleeve 20 and a valve main body 21 that is fitted into the sleeve 20. The sleeve 20 has a lead-out inlet 20 a for connecting the pipe line 11, an inlet 20 b to which a pipe line 15 of a pump 14 for supplying the working fluid at a predetermined pressure is connected, and the working fluid is discharged to the reservoir tank 16. The outlet 20c to which the pipe line 17 is connected is formed. Further, the valve body 21 is formed with a supply path 21a that connects the inlet 20b and the outlet inlet 20a at a predetermined operating position, and a discharge path 21b that connects the outlet 20c and the outlet inlet 20a at other operating positions. Has been. The working fluid supplied to the anti-piston rod side cylinder chamber 1A is sealed between the supply passage 21a and the discharge passage 21b without connecting the outlet 20a to either the inlet 20b or the outlet 20c. The sealing part 21c which can be formed is formed. A relief valve and a check valve are provided in the pipe line 15 between the pump 14 and the inlet 20b. When the supply passage 21a of the valve body 21 is in a position where the inlet 20b and the outlet 20a communicate with each other, the working fluid is supplied to the anti-piston rod side cylinder chamber 1A by the pump 14 at a predetermined pressure, and the valve body 21 is discharged. When the passage 21b is at a position where the outlet 20c and the outlet 20a communicate with each other, the working fluid supplied to the anti-piston rod side cylinder chamber 1A is allowed to be discharged.

  The compressed gas supplied to the piston rod side cylinder chamber 1B of the cylinder 1 is received when, for example, a punch punches a workpiece and reaches a bottom dead center when a normal shearing process is actually performed. A pressure corresponding to the sliding resistance is set. Since the pressure of the working fluid supplied to the anti-piston rod side cylinder chamber 1A is considerably higher than the pressure of the gas supplied to the piston rod side cylinder chamber 1B of the cylinder 1, gas is supplied to the piston rod side cylinder chamber 1B of the cylinder 1. Even in a state where is supplied, it is possible to move the piston rod 10 in the extending direction.

  An operation member 22 for moving to a predetermined operating position within the sleeve 20 is provided at one end of the valve main body 21, and an operation member is projected from the sleeve 20 at the other end to allow the valve main body 21 to move. A spring 23 is provided to urge the supply passage 21a to coincide with the inlet 20b and the outlet 20a of the sleeve 20. Furthermore, in this embodiment, a roller 24 is rotatably provided at the tip of the operation member 22.

  A plate 30 is provided as the operation means 3 at a position corresponding to the roller 24 at the tip of the operation member 22 in a state protruding from the sleeve 20 of the upper mold plate 7. A cam surface 30 a is formed at the lower end of the plate 30. The cam surface 30a is set so as to come into contact with the roller 24 at a position where the punch comes into contact with the workpiece when the upper die plate 7 is moved downward in the actual punching process. The cam surface 30a abuts on the roller 24 to move the position of the valve body 21 relative to the outlet 20a of the sleeve 20 from the supply path 21a toward the discharge path 21b via the sealing portion 21c. When the actual punching process is performed, the position where the punch comes into contact with the roller 24 moves to the side surface 30b of the plate 30 so that the discharge passage 21b of the valve body 21 becomes the outlet of the sleeve 20. 20a is set to be kept in a state consistent with 20a.

Next, the method of the present invention will be described based on FIGS. 3 to 7 together with its operation depending on the case of using the apparatus constructed as described above.
The method of the present invention is generally for evaluating the durability of a shear press, and is equipped with a cylinder 1 that reproduces the direction and magnitude of the force generated in the shear press when the workpiece is sheared. Thus, the direction and magnitude of the force generated in the shear press when the workpiece reproduced by the cylinder 1 is sheared are switched according to the stroke of the shear press.

  As described above, the shear press in this embodiment is provided with the cam unit 4, and the number of times of shearing processing (the number of shots) in which wear of the sliding portion of the cam unit 4 of the shear press, cracking / deformation, etc. occurs. ) In advance and the durability is evaluated, and the shearing process is repeated accurately and easily.

  In evaluating the durability of the shear press, the cylinder 1 is attached to the lower mold plate 6 in advance instead of the shear mold such as a die. Then, when reproducing the shearing process, the upper mold plate 7 is positioned at the top dead center raised with respect to the lower mold plate 6, so that the cam surface 30 a of the plate 30 is the roller 24 of the switching valve 2. It is said that it is not in contact with. Therefore, the switching valve 2 is located at a position where the supply passage 21a of the valve body 21 communicates with the inlet 20b of the sleeve 20 and the outlet 20a due to the bias of the spring 23. The working fluid is supplied to the chamber 1A at a predetermined pressure.

  From this state, the upper mold plate 7 is moved downward from the top dead center and brought close to the lower mold plate 6. At this time, in an actual shearing process, no reaction force is received until the shearing die comes into contact with the workpiece (see range A in the graph of FIG. 3). Therefore, in order to reproduce this state, in the present invention, the cam surface 30a of the plate 30 of the upper mold plate 7 does not come into contact with the roller 24 of the switching valve 2, so that the valve body 21 of the switching valve 2 is supplied. The passage 21a is located at a position where the inlet 20b of the sleeve 20 and the outlet 20a communicate with each other. At this time, the working fluid is supplied to the anti-piston rod side cylinder chamber 1A by the pump 14 at a predetermined pressure.

  When the upper mold plate 7 is further moved downward and brought close to the lower mold plate 6, the cam driver 41 is moved forward by being pressed against the machining cam 40, and as shown in FIG. Then, when the shearing die comes into contact with the workpiece and starts shearing, the reaction force rapidly increases (see the range B shown on the + side of the graph of FIG. 4). Therefore, in order to accurately reproduce this state, in the present invention, the cam surface 30a of the plate 30 of the upper mold plate 7 is in contact with the roller 24 of the switching valve 2, so that the valve body 21 of the switching valve 2 is a sealed portion. 21c is moved so as to correspond to the inlet 20b of the sleeve 20 and the outlet 20a. As a result, the working fluid is sealed in the anti-piston rod side cylinder chamber 1A and the pressure only rises, and the piston rod 10 is inhibited from moving so as to reduce the volume of the anti-piston rod side cylinder chamber 1A. The Therefore, a force corresponding to the reaction force at the moment of punching is applied to the piston rod 10 of the cylinder 1 fastened with the processing cam 40, and the reaction force received by the processing cam 40 at the time of punching can be accurately reproduced. .

  When the upper mold plate 7 is further lowered and brought closer to the lower mold plate 6, the cam driver 41 pressurizes the machining cam 40 and further moves forward, and as shown in FIG. Passes through the work piece, and the reaction force having a predetermined value is almost eliminated (see the range C in which the force in the graph of FIG. 5 drops). Therefore, in order to reproduce this state, in the present invention, the roller 24 of the switching valve 2 is in contact with the side surface 30b of the plate 30 of the upper mold plate 7, and therefore the valve main body 21 of the switching valve 2 has the discharge passage 21b of the sleeve 20. Are moved so as to correspond to the outlet 20c and the outlet 20a, the working fluid in the anti-piston rod side cylinder chamber 1A can be discharged, and the pressure of the working fluid in the anti-piston rod side cylinder chamber 1A is released. The piston rod 10 of the cylinder 1 is allowed to move so as to reduce the volume of the anti-piston rod side cylinder chamber 1A with almost no resistance accompanying the processing cam 40 that moves forward by the pressurization of the cam driver 41. As a result, it is possible to accurately reproduce the state in which the machining cam 40 is further advanced with almost no resistance force when punching and penetrating the shearing type workpiece.

  When the upper mold plate 7 moves upward after reaching the bottom dead center and starts to move away from the lower mold plate 6, the press of the cam driver 41 against the machining cam 40 is released accordingly, and the return cam 53 releases the machining cam 40. Moves backwards. At this time, in the actual shearing process, the shearing die is pulled out while sliding on the workpiece, and the processing cam 40 slides with respect to the support plate 50. As described above, a resistance force smaller than the reaction force is generated in the opposite direction (from the + side to the − side) with respect to the previous reaction force. Therefore, in order to reproduce this state, in the present invention, as the plate 30 of the upper mold plate 7 moves upward, the contact position of the roller 24 of the switching valve 2 moves relative to the cam surface 30a from the side surface 30b of the plate 30. Therefore, the valve body 21 of the switching valve 2 moves so that the sealing portion 21c corresponds to the outlet 20a of the sleeve 20 from the discharge passage 21b of the valve body 21. At this time, the piston rod side cylinder chamber 1B of the cylinder 1 has a sliding resistance that is received when, for example, a punch punches out a workpiece and reaches a bottom dead center when a normal shearing process is actually performed. A gas such as compressed air is supplied at a predetermined pressure at a corresponding pressure, and a force that resists the backward movement of the machining cam 40 is applied. As a result, it is possible to accurately reproduce a relatively small force (see the minus side in the graph of FIG. 6) generated in the opposite direction to the previous reaction force (see the plus side in the graph of FIG. 4). As described above, since the pressure of the working fluid supplied to the anti-piston rod side cylinder chamber 1A is considerably higher than the pressure of the gas supplied to the piston rod side cylinder chamber 1B of the cylinder 1, the piston rod of the cylinder 1 is used. Even in a state where gas is always supplied to the side cylinder chamber 1B, the piston rod 10 can be moved in the extending direction. It is also possible to configure such that a gas such as compressed air is supplied to the piston rod side cylinder chamber 1B at a predetermined timing by opening the on-off valve only when it is in the range of D in the graph of FIG. it can.

  Subsequently, when the upper mold plate 7 further moves upward and leaves the lower mold plate 6, the cam driver 41 is separated from the machining cam 40 and the machining cam 40 stops at the retreat limit. At this time, in the actual shearing process, the shearing mold is completely pulled out from the workpiece. At this time, as indicated by the range E in the graph of FIG. 7, the machining cam 40 receives neither reaction force nor resistance force in the opposite direction. Therefore, in order to accurately reproduce this state, in the present invention, the plate 30 of the upper mold plate 7 is separated from the roller 24 of the switching valve 2, so that the valve body 21 of the switching valve 2 has the supply passage 21 a of the sleeve 20. At a position where the inlet 20b and the outlet 20a communicate with each other, the working fluid is returned to the anti-piston rod side cylinder chamber 1A at a predetermined pressure.

  In order to evaluate the durability of the shear press using the present invention, the series of operations described above are repeated as one shot reproduction in an actual shearing process, and the slide plates 41a, 40a of the cam driver 41 and the processing cam 40 are The amount of wear in the sliding portion such as the surface where the support plate 50 of the slide mechanism 5 and the processing cam 40 are in contact, the guide bar 52 of the slide mechanism 5 and the guide hole 45 of the processing cam 40, or the cam driver 41 and the processing cam 40 Cracks and deformation of the slide plates 41a and 40a, the cam driver 41 and the processing cam 40, the support plate 50 of the slide mechanism 5, the guide bar 52, etc. are confirmed every predetermined number of times. Based on this evaluation, the number of shots that can be accurately sheared is set.

  In the embodiment described above, the case of the punching press having the cam unit 4 has been described. However, the present invention is not limited to this embodiment, and may be applied to a shear press other than the punching process. The present invention can also be applied to a case where the workpiece is sheared by moving the shearing die parallel to the press direction without providing the cam unit 4. In the case where the shearing die is moved in parallel with the pressing direction, the cylinder 1 is disposed so that the axis of the piston rod 10 is parallel to the pressing direction. When the force that becomes resistance when the shearing die returns can be ignored, such as when the shearing die is moved directly close / retracted by a strong driving means such as a ram, it is compressed into the piston rod side cylinder chamber 1B of the cylinder 1 It is not necessary to supply a gas such as air. Further, in the present invention, a servo valve is employed as the switching valve 2 to detect the position of the upper mold plate 7 relative to the lower mold plate 6 instead of the plate 30 having the cam surface 30a and the roller 24 of the switching valve 2 in contact therewith. It is also possible to provide a sensor that controls the servo valve based on the detection result of the sensor.

  1: Cylinder (reproduction means) 2: Switching valve (switching means) 3: Operation means (control means) 4: Cam unit

Claims (2)

An apparatus for evaluating the durability of a shear press,
Reproduction means capable of reproducing the direction and magnitude of the force generated in the shear press when the workpiece is sheared;
Switching means for switching the direction and magnitude of the force reproduced by the reproduction means;
And a control means for controlling the switching means according to the stroke of the shear press. A method for evaluating the durability of a shear press,
Attach a reproduction means that can reproduce the direction and magnitude of the force generated in the shear press when shearing the workpiece,
A method for evaluating the durability of a shear press, wherein the direction is reproduced while switching the direction and magnitude of the force generated in the shear press when the workpiece is sheared by the reproducing means according to the stroke of the shear press.

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