JP2020182962A - Spring back prevention jig - Google Patents

Abstract

To provide a spring back prevention jig that enables inexpensive mold release without breaking a molded article, while using an existing press machine.SOLUTION: A spring back prevention jig 1 is attached to a press machine X when a molded article obtained by press-molding powder by the press machine X is released from a mold 3. The spring back prevention jig comprises: a body part 10 that has a plurality of legs 10a abutting on the mold 3, and a coupling part 10b for coupling the plurality of legs 10a at a side of an upper punch 8 with respect to the mold 3; and an urging mechanism S for urging the upper punch 8 toward the molded article. A pusher 7 pushes the coupling part 10b so as to release the molded article from the mold 3.SELECTED DRAWING: Figure 4

Description

The present invention relates to a springback prevention jig that is attached to a press machine when a molded product molded by the press machine is released from the mold.

Conventionally, there is known a press machine provided with a mold filled with powder and a pusher driven by a drive source, and the pusher presses an upper punch toward the powder to press-form the powder. For example, see Patent Documents 1 and 2).

In the press machine described in Patent Document 1, the pusher is composed of a piston driven by a hydraulic cylinder, and an upper punch is provided at the tip of the piston. The press machine described in Patent Document 1 cuts off the pressure supply from the hydraulic cylinder by a solenoid valve and airs the upper punch when the molded product formed by being pressed by the upper punch is separated from the die. The air cylinder that supplies pressure sandwiches the molded product between the upper punch and the lower punch to lower the mold. As a result, cracking, warping, etc. of the molded product due to springback are prevented.

In the press machine described in Patent Document 2, the pusher is composed of an upper ram connected to a drive device, and the upper ram is configured to move the upper punch in the vertical direction. In the press machine described in Patent Document 2, when the molded product pressed by the upper punch is released from the die, the pressure applied to the molded product does not decrease too much while slowly raising the upper punch. I'm lowering the mold. As a result, the pressure applied to the molded product is secured at a certain level or higher until the molded product is completely ejected, and peeling and cracking of the molded product due to springback is prevented.

Japanese Unexamined Patent Publication No. 9-168899 Japanese Unexamined Patent Publication No. 2001-300790

However, in the press machine described in Patent Document 1, it is necessary to separately provide a solenoid valve and an air cylinder in order to prevent springback, which complicates the device configuration and causes an increase in device cost. Further, in the press machine described in Patent Document 2, it is complicated to control the ascending speed of the upper punch and the lowering timing of the die, and it is necessary to separately provide a mechanism for lowering the die, which increases the device cost. I invite you.

Therefore, there is a demand for a springback prevention jig that can release a molded product at low cost without damaging the molded product while using an existing press machine.

The characteristic configuration of the springback prevention jig according to the present invention is that the powder is pressed by a press machine provided with a die filled with the powder, a pusher driven by a drive source, and an upper punch with which the pusher abuts. A springback prevention jig that is attached to the press machine when the molded product is released from the die, and has a plurality of legs that come into contact with the die and the die. A main body having a connecting portion for connecting a plurality of the legs on the side of the upper punch, and an urging mechanism for urging the upper punch toward the molded product, and the pusher is the connecting portion. It is a point configured to separate the molded product from the mold by pressing.

In this configuration, the connecting portion of the main body is pressed by the pusher equipped in the existing press machine to release the molded product from the mold. At this time, since the urging mechanism for urging the upper punch toward the molded product is provided, the molded product can be released from the mold while a desired pressure is applied to the molded product. As a result, the molded product to be released does not undergo a sudden pressure decrease, and damage due to springback can be prevented.

Moreover, in this configuration, a springback prevention jig equipped with a main body that contacts the die and an urging mechanism that urges the upper punch only needs to be attached to an existing press machine, and is inexpensively configured. Can be done. As described above, it has been possible to provide a springback prevention jig capable of inexpensively releasing a molded product without damaging the molded product while using an existing press machine.

Another characteristic configuration is that the urging mechanism connects a base portion fixed to the connecting portion, a plurality of support legs having one end supported by the base, and the other ends of the support legs. It has a contact member including a connecting portion that contacts the punch, and a plurality of spring members arranged on the outer peripheral side of the plurality of support legs.

In the springback prevention jig of this configuration, the urging mechanism is composed of a contact member including a base fixed to the connecting portion of the main body and a spring member arranged on the outer peripheral side of the support leg supported by the base. Since it is configured, the main body and the urging member are unitized. Therefore, it becomes easy to attach the springback prevention jig to the existing press machine. Further, since the urging mechanism is in contact with the upper punch at the connecting portion connecting the plurality of support legs in a state where the plurality of spring members are arranged on the outer peripheral side of the plurality of support legs, the upper punch is provided. It is possible to stably secure the urging force acting on the. Therefore, damage due to springback in the molded product can be reliably prevented.

Another characteristic configuration is that the urging mechanism is screwed into the support leg portion and further has an adjusting screw for adjusting the urging force of the spring member.

If an adjusting screw for adjusting the urging force of the spring member is provided as in this configuration, the urging force acting on the molded product via the upper punch should be optimized according to the shape and characteristics of the molded product. Can be done. Moreover, since the adjusting screw is screwed into the support leg, it is possible to adjust the urging force of the spring member after attaching the springback prevention jig to the existing press machine, which is highly convenient.

Another characteristic configuration is that the urging mechanism is arranged between an erection portion erected over a plurality of the legs between the connecting portion and the upper punch, and between the erection portion and the upper punch. The point is that the spring member is included, and the seat portion that supports the end portion of the spring member is included, and the screw member that is screwed into the erection portion is provided.

As in this configuration, a part of the urging mechanism is composed of an erection portion erected over the legs of the main body portion, and the erection portion is provided with a screw member including a seat portion that supports the end portion of the spring member. Since it has a simple structure such as screwing, a springback prevention jig can be manufactured at low cost. In addition, since the erection part, screw member, and spring member are provided between the connecting part and the upper punch, the urging mechanism does not interfere with the pusher that presses the connecting part, and the existing press machine is spring-backed. It is easy to attach the prevention jig. Moreover, by adjusting the amount of screwing of the screwing member with respect to the erection portion, the urging force of the spring member supported by the seat portion of the screwing member can be adjusted, so that the upper punch can be adjusted according to the shape and characteristics of the molded product. The urging force acting on the molded product via the above can be optimized.

Another characteristic configuration is that the urging mechanism includes a spring member arranged between the connecting portion and the upper punch, a seat portion supporting the end portion of the spring member, and a screw in which the seat portion is screwed. It is a point that includes a portion and has a support portion fixed to the connecting portion.

Since the support portion is fixed to the connecting portion and the end portion of the spring member is supported by the seat portion of the support portion as in this configuration, the springback prevention jig can be manufactured at low cost. it can. Moreover, since the urging force of the spring member supported by the seat can be adjusted by adjusting the screwing amount of the seat with respect to the screw portion, the molded product can be made into a molded product via an upper punch according to the shape and characteristics of the molded product. The acting urging force can be optimized.

Another characteristic configuration is that the urging mechanism includes a plate member arranged between the connecting portion and the upper punch, an abutting screw screwed into the plate member and abutting on the upper punch, and the above. A tension spring whose one end is supported by a plate member and urges the abutting screw toward the upper punch, a restrained state which supports the other end of the tension spring and exerts the urging force of the tension spring, and the tension spring. It has a switching member that can be switched to a released state for releasing the urging force of the above.

Since the springback prevention jig of this configuration is configured by supporting the tension spring by the plate member to which the contact screw is screwed and the switching member, the contact screw can be used according to the shape and characteristics of the molded product. By changing the screwing amount, the urging force of the tension spring acting on the molded product via the abutting screw and the upper punch can be optimized. Moreover, if a switching member is provided as in this configuration, when the molded product is released from the mold, damage due to springback is prevented by applying a desired pressure to the molded product by the urging force of the tension spring, and the molded product is prevented from being damaged. After the mold is released, the urging force of the tension spring is released, so that the molded product can be easily taken out.

It is an overall side view of a press machine. It is the schematic explaining the press molding. It is a perspective view of the springback prevention jig which concerns on 1st Embodiment. It is an overall side view of the press machine in the state which attached the springback prevention jig which concerns on 1st Embodiment. It is an overall side view explaining the mold release using the springback prevention jig which concerns on 1st Embodiment. It is an overall side view explaining the mold release using the springback prevention jig which concerns on 1st Embodiment. It is a side view of the springback prevention jig which concerns on 2nd Embodiment. It is a side view of the springback prevention jig which concerns on 3rd Embodiment. It is a perspective view of the springback prevention jig which concerns on 4th Embodiment. It is an overall side view explaining the mold release using the springback prevention jig which concerns on 4th Embodiment. It is a perspective view of the springback prevention jig which concerns on 5th Embodiment. It is an overall side view explaining the mold release using the springback prevention jig which concerns on 5th Embodiment.

Hereinafter, embodiments of the springback prevention jig according to the present invention will be described with reference to the drawings. In the present embodiment, as an example of the springback prevention jig, the springback prevention jig 1 mounted on the movable frame type press machine X (hereinafter, referred to as “press machine”) will be described. However, the present invention is not limited to the following embodiments, and various modifications can be made without departing from the gist thereof.

FIG. 1 shows a manual press X using the third law of Newtonian mechanics, "the law of action and reaction". The press machine X according to the present embodiment includes a movable frame 2, a die 3, a spacer 4, a fixed frame 5, a cylinder 6, a movable rod 7 (an example of a pusher), an upper punch 8, a lower punch 9, and a drive source K. I have. In the following description, the direction of gravity will be described as the bottom, and the direction opposite to the direction of gravity as the top.

The movable frame 2 is formed in a rectangular shape, and has a lower base 21, an upper base 22, a plurality of (two in the present embodiment) columnar columns 23 fixed over the lower base 21 and the upper base 22, and the lower base 21. It has a lower punch support base 24 which is fixed to and supports the lower punch 9. A through hole 22a is formed in the center of the upper table 22 into which the movable rod 7 is inserted so as to be relatively movable. A lubricating material or the like is used for the sliding surface between the through hole portion 22a and the movable rod 7, and the sliding resistance is reduced.

The mold 3 has a cylindrical shape in which an insertion hole 31 into which the upper punch 8 and the lower punch 9 are inserted from the vertical direction without gaps is formed through the center, and is formed in the fixed frame 5 via the spacer 4. It is supported. The insertion hole 31 is filled with powder such as chemicals or ceramic with the lower punch 9 inserted without a gap.

The fixed frame 5 includes a flat plate-shaped mounting plate 51, a plurality of (four in the present embodiment) support legs 52 fixed to the four corners of the mounting plate 51 to support the mounting plate 51, and the mounting plate 51. It has a plurality of bearings 53 (two in this embodiment) that are fixed to the side of the column and slidably support the columnar column 23. The plurality of support legs 52 are fixed to a table T that is stably placed on the ground. The bearing 53 reduces the frictional resistance generated between the movable frame 2 and the columnar column 23 when the movable frame 2 moves relative to the fixed frame 5, and is composed of, for example, a slide bearing or a ball bearing. , Lubricating material or the like is used for the sliding surface.

The movable rod 7 has a piston 71 having a pressure receiving surface 71a and a pressing portion 72 for pressing the upper punch 8. When air, oil, or the like is supplied from the drive source K to the inside of the cylinder 6, pressure acts on the pressure receiving surface 71a to move the movable rod 7 downward, and a predetermined pressing force is applied to the upper punch 8. .. In the drive source K in the present embodiment, a fluid such as air or oil sucked by rotating the manual lever Kb is supplied to the inside of the cylinder 6, and the fluid pressure in the cylinder 6 serves as a pointer of the load meter Ka. It is configured to act on the upper punch 8 via the movable rod 7 as a corresponding load. The drive source K is not limited to the manual pump type, and may be an electric type using an electric pump or the like, or may have a structure in which the movable rod 7 is moved up and down by operating the handle.

The upper punch 8 has a plan-view circular upper bottom plate 81 to which the pressing portion 72 of the movable rod 7 abuts, and an upper pressing portion 82 that presses the powder filled inside the mold 3 from above. ing. The lower punch 9 includes a bottom plate 91 having a circular shape in a plan view with which the lower punch support base 24 of the movable frame 2 abuts, and a lower press portion 92 that presses the powder filled inside the mold 3 from below. have.

FIG. 2 shows an explanatory schematic view for press-molding powder using the press machine X in the present embodiment. As shown in FIG. 2A, the lower punch 9 supported by the lower punch support base 24 of the movable frame 2 is inserted into the mold 3, and the mold 3 is inserted into the fixed frame 5 via the spacer 4. To support. Then, the inside of the mold 3 is filled with powder, and the upper punch 8 is placed on the powder.

Next, as shown in FIG. 2B, by supplying air or oil from the drive source K to the cylinder 6, pressure acts on the pressure receiving surface 71a of the movable rod 7, and the pressing portion 72 of the movable rod 7 is pressed. It comes into contact with the upper punch 8 and presses the upper punch 8 toward the powder inside the mold 3. As a result, compression molding of the powder is started, and when the powder begins to solidify, frictional resistance is generated between the powder and the side wall inside the mold 3, and the upper punch load is not 100% transmitted to the lower punch 9. Then, when the upper punch load becomes larger than the lower punch load and the load difference becomes larger than the sum of the own weight of the movable frame 2 and the sliding resistance between the movable frame 2 and the bearing 53 and the movable rod 7. The movable frame 2 begins to rise due to the action and reaction of the contact surface between the pressing portion 72 of the movable rod 7 and the upper bottom plate 81 of the upper punch 8 as a fulcrum.

Then, as shown in FIG. 2C, the movable frame 2 rises to increase the lower punch load, and the powder is compressed from above and below until the compression load becomes uniform. After that, the load difference between the upper and lower punches is only the own weight of the movable frame 2 and a slight sliding resistance, and powder compression is continued uniformly up and down until an arbitrary set load is reached. Compared with this design load, the weight of the movable frame 2 and the slight sliding resistance are negligibly small values, and it is possible to realize uniform biaxial molding of powder. As described above, the press machine X in the present embodiment does not require precise load control and has an extremely simple device configuration as compared with the case where the lower punch 9 is driven in addition to the upper punch 8 to press-mold from both shafts. It has become something like that.

After the powder is press-molded, the molded product is released from the mold 3. At this time, since a compressive force from the side wall inside the mold 3 acts on the molded product, when the molded product is exposed from the mold 3 and the compressive force is released, the volume of the molded product increases. An expanding springback occurs. As a result, local strain may occur inside the molded product, which may cause cracks.

[Springback prevention jig of the first embodiment]
Therefore, in the present embodiment, when the press-molded molded product is released from the mold 3, the springback prevention jig 1 shown in FIGS. 3 to 4 is attached to the press machine X. The springback prevention jig 1 connects a plurality of (two in this embodiment) leg portions 10a that come into contact with the mold 3 and a plurality of leg portions 10a on the side of the punch 8 above the mold 3. A main body portion 10 having a portion 10b, and an urging mechanism S for urging the upper punch 8 toward the molded product are provided. The main body 10 is integrally formed with the legs 10a and the connecting portions 10b, and is formed in a U-shape in a side view.

The urging mechanism S in the present embodiment includes a base 11 fixed to the connecting portion 10b, a plurality of support legs 12a having one end supported by the base 11, and a plurality of support legs 12a. A contact member 12 including a connecting portion 12b that connects the other ends of the above and abuts on the upper punch 8, and a plurality of (two in the present embodiment) spring members 13 arranged on the outer peripheral side of the plurality of support leg portions 12a. And have. The contact member 12 is formed by integrally forming the support leg portion 12a and the connecting portion 12b, and is composed of a rod-shaped member having a U-shape in a side view. One end of the spring member 13 is supported by the base portion 11, and the other end is supported by the adjusting screw 14 screwed into the support leg portion 12a. The adjusting screw 14 can adjust the urging force of the spring member 13.

The plurality of leg portions 10a of the main body portion 10 are each formed in a plate shape, and a long hole portion 10a1 which is a long hole in the vertical direction is formed. The connecting portion 12b of the contact member 12 is inserted into the elongated hole portion 10a1, and the upper punch 8 moves in the vertical direction so that the connecting portion 12b in contact with the upper punch 8 is formed together with the supporting leg portion 12a. The length of the hole is such that it can be moved in the vertical direction.

The base portion 11 is integrally formed with a U-shaped portion 11a screwed to the connecting portion 10b and a pair of flange portions 11b extending outward from the U-shaped portion 11a. A support hole 11b1 for supporting the support leg portion 12a is formed in the pair of flange portions 11b by inserting one end of each support leg portion 12a, and the pair of support leg portions 12a is formed with respect to the base portion 11. It is supported so that it can move in the vertical direction.

A locking member 12a1 composed of a washer, a nut, or the like is attached to an end (one end) of the support leg 12a on the side penetrating the support hole 11b1, and the locking member 12a1 is a flange portion of the base 11. By abutting on 11b, the downward movement of the support leg portion 12a is restricted. Further, the other ends of the pair of support legs 12a are connected to the connecting portions 12b, and male screw portions 12a2 into which the adjusting screws 14 are screwed are formed on the other ends of the pair of support legs 12a. There is. The spring member 13 is composed of a compression coil spring whose urging force increases as it is compressed.

When assembling the springback prevention jig 1, the adjusting screw 14 and the spring member 13 are inserted into the support leg portion 12a of the abutting member 12 with the connecting portion 12b of the abutting member 12 inserted into the elongated hole portion 10a1 of the main body portion 10. Is attached in this order, and one end of the support leg portion 12a is inserted into the support hole 11b1 of the base portion 11 to fix the locking member 12a1. Then, if the main body portion 10 and the base portion 11 are screwed and fixed, the springback prevention jig 1 can be handled as an integrated unit.

The procedure for mounting the springback prevention jig 1 on the press machine X and releasing the molded product from the mold 3 will be described with reference to FIGS. 4 to 6. When mounting the springback prevention jig 1, the movable rod 7 is raised while releasing the pressure inside the cylinder 6 from the state shown in FIG. 2C.

Then, as shown in FIG. 4, with the leg portion 10a of the main body portion 10 in contact with the upper surface of the mold 3, the adjusting screw 14 is operated to push the connecting portion 12b of the contact member 12 to the upper punch 8. It is brought into contact with the upper bottom plate 81. Then, by supplying air or oil from the drive source K to the cylinder 6, pressure acts on the pressure receiving surface 71a of the movable rod 7 to lower the movable rod 7, and the pressing portion 72 of the movable rod 7 is pressed by the U of the base 11. It is brought into contact with the character portion 11a. Then, the adjusting screw 14 is operated to adjust the urging force of the spring member 13, and the mounting of the springback prevention jig 1 on the press machine X is completed.

Next, as shown in FIG. 5, by further supplying air or oil from the drive source K to the cylinder 6, pressure acts on the pressure receiving surface 71a of the movable rod 7, and the pressing portion 72 of the movable rod 7 presses the base 11. Although it is pressed downward, the base portion 11 is fixed to the main body portion 10, and the main body portion 10 is restricted from moving downward by the fixing frame 5 via the mold 3 and the spacer 4. As a result, the pressing force of the movable rod 7 does not act on the upper punch 8. On the other hand, a load for lifting the movable frame 2 upward is applied by the air or oil supplied to the cylinder 6, and this load is the friction between the movable frame 2 and the movable frame 2 and the bearing 53 and the movable rod 7. When it becomes larger than the sum of the dynamic resistance, the frictional resistance between the side wall inside the mold 3 and the molded product, and the urging force of the spring member 13, the movable frame 2 starts to rise. Then, the lower punch 9 rises together with the movable frame 2, the molded product starts to be exposed from the mold 3, and finally the whole is exposed and the mold is released.

At this time, as shown in FIG. 6, since one end of the spring member 13 is supported by the base portion 11 which is pressed by the movable rod 7 and whose movement is restricted, the urging force of the spring member 13 is applied to the contact member 12. Acts on the upper punch 8 via the upper punch 8, and the upper punch 8 presses the molded product downward. That is, the urging force of the spring member 13 acts on the molded product exposed from the mold 3 while being sandwiched between the upper punch 8 and the lower punch 9, and the molded product has the side wall inside the mold 3. There is no frictional resistance with the molded product and a compressive force is applied from above and below. As a result, it becomes possible to apply a compressive force substantially evenly from the vertical direction to the molded product exposed from the mold 3, and springback can be reliably prevented. Moreover, the greater the amount of exposure of the molded product from the mold 3, the greater the compressive force acting on the molded product. Therefore, it is possible to apply a desired compressive force to the molded product against the expansion force of the molded product, which increases in proportion to the exposure amount of the molded product, and springback can be reliably prevented. it can. As a result, it is possible to prevent inconveniences such as local strain occurring inside the molded product and cracks.

[Springback prevention jig of the second embodiment]
Instead of the springback prevention jig 1 according to the first embodiment, the springback prevention jig 1A as shown in FIG. 7 may be mounted on the press machine X.

The springback prevention jig 1A in the present embodiment has a plurality of (two in the present embodiment) leg portions 10Aa that come into contact with the mold 3 and a plurality of leg portions 10Aa on the side of the punch 8 above the mold 3. It includes a main body portion 10A having a connecting portion 10Ab to be connected, and an urging mechanism SA for urging the upper punch 8 toward the molded product. The main body portion 10A is formed by integrally forming the leg portion 10Aa and the connecting portion 10Ab, and is formed in a U-shape in a side view.

The urging mechanism SA includes an erection portion 15 erected between the connecting portion 10Ab and the upper punch 8 over a plurality of leg portions 10Aa, and a spring member 13A arranged between the erection portion 15 and the upper punch 8. , A seat portion 16a that supports an end portion of the spring member 13A, and a screwing member 16 that is screwed into the erection portion 15. The spring member 13A is composed of a compression coil spring whose urging force increases as it is compressed.

The plurality of leg portions 10Aa of the main body portion 10A are each formed in a plate shape. The erection portion 15 is integrally formed with a plurality of leg portions 10Aa, and is composed of a plate-shaped member having a female screw hole 15a in the central portion. The erection portion 15 may be formed of a plurality of leg portions 10Aa and separate members and fixed with screws or the like.

The screwing member 16 includes a seat portion 16a that supports the end portion of the spring member 13A, and a rod-shaped male screw rod 16b having one end connected to the seat portion 16a and having a male screw screwed into the female screw hole 15a formed on the outer circumference. The other end of the male screw rod 16b is connected, and has a grip portion 16c for the operator to grip and rotate.

The seat portion 16a is integrally formed with a convex portion 16a1 to which one end of the spring member 13A fits externally and a regulating plate 16a2 that comes into contact with one end of the spring member 13A to regulate the movement of the spring member 13A. The seat portion 16a is fixed to the male screw rod 16b by screwing, press fitting, or the like. By rotating the grip portion 16c, the male screw rod 16b and the seat portion 16a rotate integrally, and the initial position and urging force of the spring member 13A can be adjusted.

When assembling the springback prevention jig 1A, the male screw rod 16b in which the grip portion 16c is integrated is screwed into the female screw hole 15a of the erection portion 15, and the seat portion 16a is fixed to one end of the male screw rod 16b. One end of the spring member 13A is fitted onto the convex portion 16a1 of 16a. As a result, the springback prevention jig 1A can be handled as an integrated unit.

Then, with the leg portion 10Aa of the main body portion 10A in contact with the upper surface of the mold 3, the grip portion 16c is rotated to bring the other end of the spring member 13A into contact with the upper bottom plate 81 of the upper punch 8. .. Then, the grip portion 16c is rotated to adjust the urging force of the spring member 13A. Next, as in the first embodiment, by supplying air or oil from the drive source K to the cylinder 6, pressure acts on the pressure receiving surface 71a of the movable rod 7 to lower the movable rod 7, and the movable rod 7 The pressing portion 72 is brought into contact with the connecting portion 10Ab of the main body portion 10A. As a result, the attachment of the springback prevention jig 1A to the press machine X is completed. Hereinafter, the operation method and the operation and effect of the press machine X for releasing the molded product from the mold 3 are the same as those in the first embodiment described above, and thus the description thereof will be omitted.

[Springback prevention jig of the third embodiment]
Instead of the springback prevention jigs 1 and 1A according to the first to second embodiments, the springback prevention jig 1B as shown in FIG. 8 may be mounted on the press machine X.

The springback prevention jig 1B in the present embodiment has a plurality of (two in the present embodiment) leg portions 10Ba that abut on the mold 3 and a plurality of leg portions 10Ba on the side of the punch 8 above the mold 3. It is provided with a main body portion 10B having a connecting portion 10Bb to be connected, and an urging mechanism SB for urging the upper punch 8 toward the molded product. In the main body portion 10B, the leg portion 10Ba and the connecting portion 10Bb are integrally formed, and the main body portion 10B is formed in a U-shape in a side view.

The urging mechanism SB is a male screw rod 18a (screw) in which a spring member 13B arranged between the connecting portion 10Bb and the upper punch 8 and a seat portion 17 and a seat portion 17 supporting the end portion of the spring member 13B are screwed together. It has a support portion 18 fixed to the connecting portion 10Bb, including an example of the portion). The spring member 13B is composed of a compression coil spring whose urging force increases as it is compressed.

The connecting portion 10Bb of the main body portion 10B is composed of a plate-shaped member having a female screw hole 10Bb1 in the central portion. The support portion 18 is fixed to a rod-shaped male screw rod 18a having a male screw screwed into the female screw hole 10Bb1 formed on the outer circumference, a seat portion 17 screwed to one end of the male screw rod 18a, and the other end of the male screw rod 18a. It has a grip portion 18b for the operator to grip and rotate. The seat portion 17 is regulated to restrict the movement of the spring member 13B by contacting one end of the spring member 13B with the convex portion 17a including the female screw screwed into the male screw rod 18a on the inner surface and the one end of the spring member 13B. The plate 17b is integrally formed. Further, the other end of the spring member 13B is fitted on the support tool 19 mounted on the upper punch 8. The support tool 19 has a convex portion 19a on which the other end of the spring member 13B fits externally, and a contact plate 19b that abuts on the upper punch 8. The support 19 may be omitted.

When assembling the springback prevention jig 1B, the male screw rod 18a is screwed into the female screw hole 10Bb1 of the connecting portion 10Bb by rotating the grip portion 18b, and the seat portion 17 is screwed into one end of the male screw rod 18a to form the seat portion. One end of the spring member 13A is fitted onto the convex portion 17a of 17, and the other end of the spring member 13A is fitted onto the convex portion 19a of the support tool 19. As a result, the springback prevention jig 1B can be handled as an integrated unit.

Then, with the leg portion 10Ba of the main body portion 10B in contact with the upper surface of the mold 3, the regulation plate 17b is rotated to push the support tool 19 to which the other end of the spring member 13B is fitted externally into the upper punch 8. It is brought into contact with the upper bottom plate 81. Then, the restricting plate 17b is rotated to adjust the urging force of the spring member 13B. Then, as in the first embodiment and the second embodiment, by supplying air or oil from the drive source K to the cylinder 6, pressure acts on the pressure receiving surface 71a of the movable rod 7 to lower the movable rod 7. , The pressing portion 72 of the movable rod 7 is brought into contact with the grip portion 18b of the supporting portion 18. As a result, the attachment of the springback prevention jig 1B to the press machine X is completed. Hereinafter, the operation method and the operation and effect of the press machine X for releasing the molded product from the mold 3 are the same as those in the first embodiment described above, and thus the description thereof will be omitted.

[Springback prevention jig of the fourth embodiment]
Instead of the springback prevention jigs 1, 1A and 1B according to the first to third embodiments, the springback prevention jig 1C as shown in FIG. 9 may be mounted on the press machine Xa. In the press machine Xa of the present embodiment, the fixed frame 5 in the above-mentioned press machine X is omitted, the shapes of the movable frame 2 and the spacer 4 are different, and the other configurations are the same, so detailed description thereof will be omitted.

As shown in FIG. 10, the press machine Xa used in the present embodiment is driven by a movable frame 2A, a die 3, a spacer 4A, a cylinder 6, a movable rod 7 (an example of a pusher), an upper punch 8 and a lower punch 9. It includes a source K and a movable member 20.

The movable frame 2A is formed in a rectangular shape, and has a lower base 21A, an upper base 22A, and a plurality of (two in the present embodiment) rod-shaped columns 23A fixed over the lower base 21A and the upper base 22A. ing. A through hole 22Aa into which the movable rod 7 is inserted so as to be relatively movable is formed in the center of the upper base 22A. A lubricating material or the like is used for the sliding surface between the through hole portion 22Aa and the movable rod 7, and the sliding resistance is reduced. Further, a female screw portion 23Aa into which the position fixing screw 25 described later is screwed is formed on the outer periphery of the rod-shaped support 23A above the mold 3.

The lower base 21A is composed of a plate-shaped member that supports the lower punch 9. The spacer 4A is formed with a notch 4Aa in which the lower base 21A can move up and down (see FIG. 9). The movable member 20 is composed of a plate-shaped member inserted so as to be vertically movable over a pair of rod-shaped columns 23A, and is arranged at a position capable of contacting the upper bottom plate 81 of the upper punch 8.

As shown in FIG. 9, the springback prevention jig 1C in the present embodiment has a plurality of (four in this embodiment) leg portions 10Ca that abut on the mold 3 and a side of the punch 8 above the mold 3. It is provided with a main body portion 10C having a connecting portion 10Cb for connecting a plurality of leg portions 10Ca, and an urging mechanism SC for urging the upper punch 8 toward the molded product. The main body portion 10C is formed by integrally forming the leg portion 10Ca and the connecting portion 10Cb, and is formed in a U-shape in a side view.

The urging mechanism SC fixes the relative position (interval) between the movable member 20 inserted so as to be vertically movable over the pair of rod-shaped columns 23A of the press machine Xa, the lower base 21A of the movable frame 2A, and the movable member 20. It has a position fixing screw 25. That is, the upper punch 8 is attached to the molded product by the movable member 20 and the position fixing screw 25 so that the lower punch 9 supported by the lower base 21A and the upper punch 8 in contact with the movable member 20 compress the molded product. It is gaining momentum. The movable member 20 is configured to be movable in the vertical direction between the pair of legs 10Ca.

FIG. 10 shows an explanatory schematic view of a procedure for releasing a molded product in which powder is press-molded from the mold 3 using the press machine Xa in the present embodiment. As shown in FIG. 10A, the lower punch 9 supported by the lower base 21A of the movable frame 2A is inserted into the mold 3, and the mold 3 is supported by the table T via the spacer 4A. Then, the inside of the mold 3 is filled with powder, the upper punch 8 is placed on the powder, and the movable member 20 is brought into contact with the upper bottom plate 81 of the upper punch 8.

Next, as shown in FIG. 10B, by supplying air or oil from the drive source K to the cylinder 6, pressure acts on the pressure receiving surface 71a of the movable rod 7, and the pressing portion 72 of the movable rod 7 is pressed. It comes into contact with the movable member 20 and presses the upper punch 8 toward the powder inside the mold 3 via the movable member 20. As a result, compression molding of the powder is started, and when the powder begins to solidify, pressure is generated on the side wall inside the mold 3, and the upper punch load is not 100% transmitted to the lower punch 9. Then, when the upper punch load becomes larger than the lower punch load and the load difference becomes larger than the total of the own weight of the movable frame 2A and the sliding resistance between the movable frame 2A and the movable rod 7, the movable rod 7 The movable frame 2A begins to rise due to the action and reaction with the contact surface between the pressing portion 72 and the movable member 20 as a fulcrum. Then, the movable frame 2 rises to increase the lower punch load, and the powder is compressed from above and below until the compression load becomes uniform, and the molded product is completed.

Next, as shown in FIG. 10 (c), the position fixing screw 25 is tightened, and the upper punch 8 is urged toward the molded product via the movable member 20. Then, the movable rod 7 is raised while releasing the pressure inside the cylinder 6.

Next, as shown in FIG. 10D, the main body portion 10C is mounted between the mold 3 and the movable rod 7, and the leg portion 10Ca of the main body portion 10C is brought into contact with the upper surface of the mold 3. Then, pressure acts on the pressure receiving surface 71a of the movable rod 7 by supplying air or oil from the drive source K to the cylinder 6 in a state where the legs 10Ca of the main body 10C are in contact with the upper surface of the mold 3. Then, the movable rod 7 is lowered, and the pressing portion 72 of the movable rod 7 is brought into contact with the connecting portion 10Cb of the main body portion 10C.

Next, as shown in FIG. 10 (e), by continuously supplying air or oil from the drive source K to the cylinder 6, pressure acts on the pressure receiving surface 71a of the movable rod 7, and the pressing portion 72 of the movable rod 7 is applied. Presses the main body 10C downward, but the main body 10C is restricted from moving downward by the table T via the mold 3 and the spacer 4A. As a result, the pressing force of the movable rod 7 does not act on the upper punch 8. On the other hand, a load that lifts the movable frame 2A upward by the air or oil supplied to the cylinder 6 acts, and this load is the weight of the movable frame 2A and the sliding resistance between the movable frame 2A and the movable rod 7. When it becomes larger than the sum of the frictional resistance between the side wall inside the mold 3 and the molded product, the movable frame 2A starts to rise. Then, the lower punch 9 rises together with the movable frame 2A, the molded product starts to be exposed from the mold 3, and finally the whole is exposed and the mold is released.

At this time, the upper punch 8 is directed toward the molded product by the movable member 20 and the position fixing screw 25 so that the lower punch 9 supported by the lower base 21A and the upper punch 8 in contact with the movable member 20 compress the molded product. Since it is urged, a compressive force that is almost evenly applied from the vertical direction acts on the molded product. As a result, it becomes possible to apply a compressive force to the molded product exposed from the mold 3 from the vertical direction, and springback can be reliably prevented.

[Springback prevention jig of the fifth embodiment]
Instead of the springback prevention jigs 1, 1A, 1B, and 1C according to the first to fourth embodiments, the springback prevention jig 1D as shown in FIG. 11 is used in the first to third embodiments. It may be attached to the press machine X according to the above.

The springback prevention jig 1D in the present embodiment has a plurality of (two in the present embodiment) leg portions 10Da that abut on the mold 3 and a plurality of leg portions 10Da on the side of the punch 8 above the mold 3. It includes a main body portion 10D having a connecting portion 10Db to be connected, and an urging mechanism SD for urging the upper punch 8 toward the molded product. The main body 10D is formed by integrally forming the leg portion 10Da and the connecting portion 10Db, and is formed in a U-shape in a side view.

The urging mechanism SD includes a plate member 26 arranged between the connecting portion 10Db and the upper punch 8, a contact screw 27 screwed into the plate member 26 and having a tip portion abutting on the center of the upper punch 8. One end is supported by both ends of the plate member 26, and a pair of tension springs 13D that urge the contact screw 27 toward the upper punch 8 and the other end of the pair of tension springs 13D are supported, and the tension spring 13D is attached. It has a pair of switching members 28 that can be switched between a restraining state for exerting a force and a releasing state for releasing the urging force of the tension spring 13D. The tension spring 13D is composed of a tension coil spring whose urging force increases as it is pulled. A flat plate member may be fixed to the tip of the contact screw 27, and the flat plate member may be stably brought into contact with the upper punch 8.

The plurality of leg portions 10Da of the main body portion 10D are each formed in a plate shape, and a long hole portion 10Da1 which is a long hole in the vertical direction is formed. Both ends of the plate member 26 are inserted into the elongated hole portion 10Da1, and the upper punch 8 moves in the vertical direction so that the abutting screw 27 in contact with the upper punch 8 moves in the vertical direction together with the plate member 26. It is the length of the hole that can be moved to. Further, a pair of projecting portions 10Da2 projecting outward are formed at the ends of the plurality of leg portions 10Da.

A contact screw 27 is screwed into the central portion of the plate member 26, and a semicircular first locking portion 26a having a round hole in which one end of the tension spring 13D is locked is provided at both ends. It is formed. The pair of first locking portions 26a are respectively arranged outside the leg portions 10Da.

The switching member 28 is a U-shaped rotating portion 28a rotatably supported by a pair of protruding portions 10Da2, and an end portion of the rotating portion 28a opposite to the protruding portion 10Da2, in addition to the tension spring 13D. A second locking portion 28b that locks the ends is integrally formed. When the pair of switching members 28 are in a posture along the vertical direction (see FIG. 12A), the tension spring 13D is in a restrained state in which the urging force is exerted, and the pair of switching members 28 are in an open posture. When (see FIG. 12C) is the release state in which the urging force of the tension spring 13D is released.

When assembling the springback prevention jig 1D, the switching member 28 is attached to the pair of protruding portions 10Da2 of the leg portion 10Da, and the first locking portion 26a of the plate member 26 into which the contact screw 27 is screwed is attached to the leg portion 10Da. Is inserted into the elongated hole portion 10Da1 of the above, and the other end of the tension spring 13D is locked to the second locking portion 28b of the switching member 28 while locking one end of the tension spring 13D to the first locking portion 26a. As a result, the springback prevention jig 1D can be handled as an integrated unit.

FIG. 12 shows an explanatory schematic view of a procedure for releasing a molded product in which powder is press-molded from the mold 3 using the press machine X in the present embodiment. When mounting the springback prevention jig 1D, the movable rod 7 is raised while releasing the pressure inside the cylinder 6 from the state shown in FIG. 2C.

Then, as shown in FIG. 12A, the leg portion 10Da of the main body portion 10D is brought into contact with the upper surface of the mold 3 and is movable by supplying air or oil from the drive source K to the cylinder 6. The pressing portion 72 of the rod 7 is brought into contact with the connecting portion 10Db. Then, the urging force of the tension spring 13D is adjusted by operating the contact screw 27 that abuts on the upper punch 8, and the attachment of the springback prevention jig 1D to the press machine X is completed.

Next, as shown in FIG. 12B, a load for lifting the movable frame 2 upward is applied by the air or oil supplied to the cylinder 6, the lower punch 9 rises together with the movable frame 2, and the molded product is made of gold. It starts to be exposed from the mold 3, and finally the whole is exposed and the mold is released. At this time, since the other end of the tension spring 13D is supported by the switching member 28 supported by the protruding portion 10Da2 of the main body portion 10D which is pressed by the movable rod 7 and whose movement is restricted, one end of the tension spring 13D is supported. The urging force of the tension spring 13D is transmitted to the abutting screw 27 via the supported plate member 26, and the urging force of the tension spring 13D acts on the upper punch 8 that abuts on the abutting screw 27. Press the molded product downward. That is, the urging force of the tension spring 13D acts on the molded product exposed from the mold 3 while being sandwiched between the upper punch 8 and the lower punch 9, and the molded product has the side wall inside the mold 3. There is no frictional resistance with the molded product and a compressive force is applied from above and below. As a result, it becomes possible to apply a compressive force substantially evenly from the vertical direction to the molded product exposed from the mold 3, and springback can be reliably prevented. Moreover, the greater the amount of exposure of the molded product from the mold 3, the greater the compressive force acting on the molded product. Therefore, it is possible to apply a desired compressive force to the molded product against the expansion force of the molded product, which increases in proportion to the exposure amount of the molded product, and springback can be reliably prevented. it can.

Next, as shown in FIG. 12 (c), after the molded product is completely exposed from the mold 3 and released from the mold, the switching member 28 is rotated to an open posture and the tension spring 13D is contracted. The urging force of the tension spring 13D is released. As a result, the contact of the contact screw 27 with the upper punch 8 is released, and the urging force of the tension spring 13D acting on the upper punch 8 is released, so that the molded product can be easily taken out.

[Other Embodiments]
(1) The press machine X in the above-described embodiment has been described as a double-screw molding machine that raises the movable frame 2 by pressing the upper punch 8, but raises the die 3 by pressing the lower punch 9. It may be a double-screw molding machine. Even in this case, the springback prevention jigs 1, 1A, 1B, and 1D according to the above-described embodiment can be used when the molded product is released from the mold 3.
(2) The spring members 13, 13A and 13B are not limited to the compression coil spring, and may be other elastic members such as rubber. Further, the tension spring 13D is not limited to the tension coil spring, and may be another elastic member such as rubber.
(3) The initial urging force of the spring members 13, 13A, 13B may be kept constant by omitting the mechanism (adjusting screw 14, etc.) for adjusting the urging force of the spring members 13, 13A, 13B.
(4) The shapes of the main bodies 10, 10A, 10B, 10C, and 10D are not limited to the U-shaped side view integrated parts, and may be composed of two or more parts, or may be composed of two or more side view T-shaped parts. It may be, and is not particularly limited.

INDUSTRIAL APPLICABILITY The present invention can be used as a springback prevention jig attached to a press machine when a molded product molded by the press machine is released from the mold.

1,1A, 1B, 1C, 1D: Springback prevention jig 3: Mold 7: Movable rod (pusher)
8: Upper punch 10, 10A, 10B, 10C, 10D: Main body 10a, 10Aa, 10Ba, 10Ca, 10Da: Leg 10b, 10Ab, 10Bb, 10Cb, 10Db: Connecting part 11: Base 12: Contact member 12a: Support leg 12b: Connection 13, 13A, 13B: Spring member 13D: Tension spring 14: Adjusting screw 15: Elevation 16: Screwing member 16a: Seat 17: Seat 18: Support 18a: Male screw rod (screw) Department)
26: Plate member 27: Contact screw 28: Switching member S, SA, SB, SC, SD: Biasing mechanism X, Xa: Press machine

Claims (6)

A molded product in which the powder is press-molded by a press machine provided with a mold filled with powder, a pusher driven by a drive source, and an upper punch with which the pusher abuts is released from the mold. A springback prevention jig that is sometimes attached to the press machine.
A main body having a plurality of legs that come into contact with the mold and a connecting portion that connects the plurality of legs on the upper punch side of the mold.
A urging mechanism that urges the upper punch toward the molded product is provided.
A springback prevention jig configured so that the pusher presses the connecting portion to release the molded product from the mold. The urging mechanism is a connecting portion that connects a base portion fixed to the connecting portion, a plurality of support legs having one end supported by the base, and the other ends of the support legs, and abuts on the upper punch. The springback prevention jig according to claim 1, further comprising a contact member including, and a plurality of spring members arranged on the outer peripheral side of the plurality of support legs. The springback prevention jig according to claim 2, wherein the urging mechanism is screwed into the support leg and further has an adjusting screw for adjusting the urging force of the spring member. The urging mechanism includes an erection portion erected over a plurality of the legs between the connecting portion and the upper punch, a spring member arranged between the erection portion and the upper punch, and the spring member. The springback prevention jig according to claim 1, further comprising a seat portion that supports an end portion of the spring member, and a screwing member screwed into the erection portion. The urging mechanism includes a spring member arranged between the connecting portion and the upper punch, a seat portion that supports an end portion of the spring member, and a screw portion into which the seat portion is screwed. The springback prevention jig according to claim 1, further comprising a support portion fixed to a connecting portion. The urging mechanism includes a plate member arranged between the connecting portion and the upper punch, an abutting screw screwed into the plate member and abutting against the upper punch, and one end supported by the plate member. A tension spring that urges the abutting screw toward the upper punch, a restraint state that supports the other end of the tension spring to exert the urging force of the tension spring, and a release state that releases the urging force. The springback prevention jig according to claim 1, further comprising a switching member capable of switching to.

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