JP2011189367A - Mold for ejecting forged pin and method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To further improve the quality of an ejected article in ejecting a pin. <P>SOLUTION: The mold includes: a die plate 24 which includes a second lower-mold through-hole 24a; a punch 14 which pushes a metal plate 2 arranged on the plate 24 from the above downward into the through-hole 24a; a knockout 28 which is arranged in the through-hole 24a and faces the punch 14, wherein the knockout is pressed by the punch 14 pushing the plate 2 down into the through-hole 24a and applies backpressure upwardly to the plate 2 while descending in the through-hole 24a to form a hollow pin P; and a mechanism for reducing stress, which makes the stress by backpressure applied from the knockout 28 to the bottom of the pin P during ejecting the pin P from the inside of the through-hole 24a smaller than the stress by backpressure applied from the knockout 28 to the bottom of the pin P during forming the pin P. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a die for forging pinning process and a forging pinning process for performing pinning processing for forming a hollow shaft protruding from the metal plate (hereinafter referred to as “hollow pin”) on the metal plate. Regarding the method.

Conventionally, as a technique for forming a hollow pin protruding from a metal plate on a metal plate, a technique for forming a hollow pin by forging press processing the metal plate is known.
An example of such a technique is disclosed in Patent Document 1.
The technique disclosed in Patent Document 1 is a die plate in which a through hole having the same inner diameter as the outer diameter of the hollow pin is formed, and a metal plate to be processed is disposed above the through hole, A punch having the same outer shape as the inner diameter of the hollow pin is lowered. Thereby, the metal plate arranged above the through hole is pushed into the through hole to form a hollow pin in the metal plate.

  At this time, the knockout that rolls the metal plate pushed by the tip of the punch onto the side surface of the hollow pin applies back pressure to the metal plate while moving to the back of the through hole in a state of facing the tip of the punch. In addition to this, the stripper plate provided around the punch holds the metal plate supported in the region where the through hole is not formed in the die plate so as not to float from the die plate.

  Then, the punch is lifted with the metal plate held by the stripper plate, and the punch is extracted from the hollow portion formed in the metal plate, and then the stripper plate is lifted to hold the metal plate by the stripper plate and the die plate. To release.

JP 2006-212703 A

However, in the technique described in Patent Document 1, when the punch is extracted from the hollow portion formed in the metal plate while the metal plate is held by the stripper plate and the die plate, the portion in which the hollow pin is formed in the metal plate In addition, back pressure from the knockout is applied.
When back pressure from the knockout is applied to the hollow pin, the formed hollow pin may be sandwiched between the stripper plate and the knockout, and may be deformed.

As described above, in the conventional technique, it is difficult to sufficiently suppress deterioration in quality of a processed product when performing pinning processing for forming a hollow pin on a metal plate.
An object of the present invention is to further improve the quality of a processed product in pinning processing.

In order to solve the above problems, a die for forging pinning processing according to an aspect of the present invention is:
A die plate (for example, the die plate 24 of FIG. 1) having a through-hole penetrating in the vertical direction (for example, the second lower mold insertion hole 24a of FIG. 1), and a metal plate (for example, FIG. A punch (for example, punch 14 in FIG. 1) that pushes the metal plate 2) into the through hole of the die plate from above, and the die plate disposed in the through hole of the die plate so as to face the punch. A hollow pin protruding from the metal plate (for example, by applying a back pressure upward to the metal plate while being pressed down by the punch for pushing the metal plate into the through hole of the die plate and descending through the through hole of the die plate , When forming the knockout (for example, the knockout 28 of FIG. 1) forming the hollow pin P) in FIG. A stress reduction mechanism for reducing stress due to back pressure applied from the knockout to the bottom surface of the hollow pin, compared to stress due to back pressure applied from the knockout to the bottom surface of the hollow pin during the formation of the hollow pin, To do.

With such a configuration, the stress due to the back pressure applied from the knockout to the bottom surface of the hollow pin when the formed hollow pin is pulled out is reduced than the stress due to the back pressure applied from the knockout to the bottom surface of the hollow pin when the hollow pin is formed. It becomes possible.
Therefore, when the formed hollow pin is extracted, it is possible to suppress the deformation generated in the formed hollow pin, and it is possible to further improve the quality of the processed product.

Moreover, the die for forging pinning processing according to one aspect of the present invention is
A stripper plate (for example, the stripper plate 12 in FIG. 1) having a through-hole penetrating in the vertical direction (for example, the second punch insertion hole 12a in FIG. 1) and sandwiching the metal plate between the die plate is provided. The punch is inserted into a through hole of the stripper plate, and the stress reduction mechanism is configured to push the metal plate disposed on the die plate into the through hole of the die plate. And a strip lock plate (for example, the plate lock mechanism 30 in FIG. 1).

With such a configuration, the stress caused by the back pressure applied from the knockout to the bottom surface of the hollow pin when the formed hollow pin is pulled out by being pushed into the through hole of the die plate and arranged in the inner space of the formed hollow pin. It is possible to generate a reaction force against
Therefore, when the formed hollow pin is extracted, it is possible to suppress the deformation generated in the formed hollow pin, and it is possible to further improve the quality of the processed product.

Moreover, the die for forging pinning processing according to one aspect of the present invention is
The stress reducing mechanism applies back pressure applied from the knockout to the bottom surface of the hollow pin when the hollow pin is extracted from the through hole of the die plate, and the bottom surface of the hollow pin from the knockout when the hollow pin is formed. It has the back pressure reduction mechanism which reduces rather than the back pressure added to a.

With this configuration, it is possible to reduce the back pressure applied from the knockout to the bottom surface of the hollow pin when the formed hollow pin is withdrawn from the back pressure applied from the knockout to the bottom surface of the hollow pin when forming the hollow pin. Become.
Therefore, when the formed hollow pin is extracted, it is possible to suppress the deformation generated in the formed hollow pin, and it is possible to further improve the quality of the processed product.

Further, the forging pin out processing method according to one aspect of the present invention,
Knockout disposed opposite to the punch in the through hole of the die plate by punching the metal plate arranged on the die plate having the through hole penetrating in the vertical direction into the through hole of the die plate from above. A hollow pin forming step of forming a hollow pin protruding from the metal plate by applying a back pressure upward to the metal plate while the pressed knockout descends the through hole of the die plate In addition, stress due to back pressure applied from the knockout to the bottom surface of the hollow pin when the hollow pin is extracted from the through hole of the die plate is applied from the knockout to the bottom surface of the hollow pin when the hollow pin is formed. And a stress reduction process for reducing the stress due to the back pressure.

With such a configuration, the stress due to the back pressure applied from the knockout to the bottom surface of the hollow pin when the formed hollow pin is pulled out is reduced than the stress due to the back pressure applied from the knockout to the bottom surface of the hollow pin when the hollow pin is formed. It becomes possible.
Therefore, when the formed hollow pin is extracted, it is possible to suppress the deformation generated in the formed hollow pin, and it is possible to further improve the quality of the processed product.

Further, the forging pin out processing method according to one aspect of the present invention,
In the hollow pin forming step, the die plate is sandwiched between the stripper plate having a through hole penetrating in the vertical direction and the die plate by the punch inserted through the through hole of the stripper plate. In the stress reducing step, the punch and the stripper plate are both moved upward while the metal plate disposed on the die plate is pushed into the through hole of the die plate. It is made to move to.

With such a configuration, the stress caused by the back pressure applied from the knockout to the bottom surface of the hollow pin when the formed hollow pin is pulled out by being pushed into the through hole of the die plate and arranged in the inner space of the formed hollow pin. It is possible to generate a reaction force against
Therefore, when the formed hollow pin is extracted, it is possible to suppress the deformation generated in the formed hollow pin, and it is possible to further improve the quality of the processed product.

Further, the forging pin out processing method according to one aspect of the present invention,
In the stress reduction step, the back pressure applied from the knockout to the bottom surface of the hollow pin when the hollow pin is extracted from the through hole of the die plate is applied to the bottom surface of the hollow pin from the knockout when the hollow pin is formed. It is characterized by being reduced more than the back pressure applied to.

With this configuration, it is possible to reduce the back pressure applied from the knockout to the bottom surface of the hollow pin when the formed hollow pin is withdrawn from the back pressure applied from the knockout to the bottom surface of the hollow pin when forming the hollow pin. Become.
Therefore, when the formed hollow pin is extracted, it is possible to suppress the deformation generated in the formed hollow pin, and it is possible to further improve the quality of the processed product.

It is a figure which shows schematic structure of the metal mold | die for a forge pin taking-out process. It is the enlarged view of the range enclosed with the circle | round | yen II in FIG. 1, and its periphery. FIG. 3 is a view taken along line III in FIG. 2. FIG. 4 is a view taken along line IV in FIG. 3. It is a figure which shows the state of the metal mold | die for a forge pin taking-out process, and a metal plate in a material holding process. FIG. 6 is a view taken along line VI in FIG. 5. It is a figure which shows the state of the metal mold | die for a forge pin taking-out process, and a metal plate in a hollow pin formation process. It is a VIII line arrow directional view of FIG. It is a figure which shows the state of the metal mold | die for a forge pin taking-out process, and a metal plate in a stress reduction process. FIG. 10 is an X-ray arrow view of FIG. 9. It is a figure which shows the state of the metal mold | die for a forge pin taking-out process, and a metal plate in a material removal process. FIG. 12 is a view taken along line XII in FIG. 11.

  Hereinafter, an embodiment (embodiment) of a die for forging pinning process and a forging pin unloading method according to the present invention will be described with reference to the drawings. In the following embodiments, the forging pin unloading die and the forging pin unloading method according to the present invention will be described as an example when applied to a progressive (forward) die. However, the forging pin unloading die and the forging pin unloading method according to the present invention are not limited to the progressive die, and may be applied to a single die, for example.

(First embodiment)
(Constitution)
(Overall configuration of die for forging pins)
First, with reference to FIGS. 1 to 4, an overall configuration of a forging pin unloading die in the first embodiment will be described.

FIG. 1 is a view showing a schematic configuration of a die 1 for forging pin unloading processing.
In FIG. 1, a die 1 for forging pins is formed by forming a hollow pin protruding from a metal plate 2 on a metal plate 2 supported and conveyed by a stock line pin (not shown) described later. It is configured to perform a certain pinning process. In the first embodiment, as an example, a case where the conveyance direction of the metal plate 2 is changed from left to right in FIG. 1 will be described.

  As shown in FIG. 1, the forging pin unloading die 1 includes an upper die set 4, an upper die backing plate 6, a punch plate 8, a stripper backing plate 10, a stripper plate 12, A punch 14 is provided. In addition, the forged pin unloading die 1 includes a pin support spring 16, a support pin 18, a lower die set 20, a lower die backing plate 22, a die plate 24, a knockout spring 26, and a knockout. 28 and a plate lock mechanism 30.

  The upper die set 4 is connected to a driving mechanism (not shown) and is formed to be movable in the vertical direction (vertical direction in FIG. 1) using a driving force generated by the driving mechanism. The drive mechanism includes, for example, a mechanical type using a rotational motion of a motor and a hydraulic type that applies pressure to a liquid such as oil. The vertical direction is the same direction as the thickness direction of the metal plate 2, and this is the same in the following description.

The upper die set 4 has an upper die recess 4a therein. The upper mold recess 4 a is a recess that opens on the lower surface of the upper mold set 4.
The upper mold backing plate 6 is attached to the lower surface of the upper mold set 4 and has a first upper mold insertion hole 6a. The first upper mold insertion hole 6a is a through-hole penetrating the upper mold backing plate 6 in the vertical direction, and is formed in the upper mold backing plate 6 at a position matching the upper mold recess 4a.

The punch plate 8 is attached to the lower surface of the upper mold backing plate 6 and has a second upper mold insertion hole 8 a and a punch arrangement hole 32.
The second upper mold insertion hole 8a is a through hole penetrating the punch plate 8 in the vertical direction, and is formed in the punch plate 8 at a position that matches the first upper mold insertion hole 6a.
The punch arrangement hole 32 is a through-hole penetrating the vicinity of the center of the punch plate 8 in the vertical direction, and has a large diameter arrangement portion 32a and a small diameter insertion hole 32b.

The large-diameter arrangement portion 32 a is a recess that opens to the upper surface of the punch plate 8. The small diameter insertion hole 32 b is a through hole that has a smaller diameter than the large diameter arrangement portion 32 a and penetrates the bottom surface of the large diameter arrangement portion 32 a and the lower surface of the punch plate 8.
The stripper backing plate 10 is disposed below the punch plate 8 and is attached to the upper surface of the stripper plate 12 using a bolt or the like (not shown).

The stripper backing plate 10 has a third upper mold insertion hole 10a and a first punch insertion hole 10b.
The third upper mold insertion hole 10a is a through-hole penetrating the stripper backing plate 10 in the vertical direction, and is formed in the stripper backing plate 10 at a position that matches the second upper mold insertion hole 8a.

The first punch insertion hole 10b is a through hole that penetrates the vicinity of the center of the stripper backing plate 10 in the vertical direction.
The stripper plate 12 is disposed below the stripper backing plate 10 and is attached to the punch plate 8 using a stripper bolt or the like (not shown). The stripper plate 12 is attached to the punch plate 8 with a stripper bolt and a coil spring (not shown) whose direction of expansion and contraction is directed upward and downward, so the distance between the stripper plate 12 and the punch plate 8 is It can change.

The stripper plate 12 has a second punch insertion hole 12a.
The second punch insertion hole 12a is a through-hole penetrating the vicinity of the center of the stripper plate 12 in the vertical direction, and is formed in the stripper plate 12 at a position matching the first punch insertion hole 10b.
The lower surface of the stripper plate 12 faces the upper surface of the metal plate 2.

The punch 14 is formed in a columnar shape having a plurality of steps having different outer diameters, and includes a large-diameter punch portion 14a and a small-diameter punch portion 14b.
The large-diameter punch portion 14a is disposed in the large-diameter arrangement portion 32a, and the upper surface thereof is in contact with the lower surface of the upper mold backing plate 6, and the lower surface thereof is opposed to the bottom surface of the large-diameter arrangement portion 32a. .

The small diameter punch portion 14b is formed with a smaller diameter than the large diameter punch portion 14a, and extends downward from the lower surface of the large diameter punch portion 14a. Further, the small diameter punch portion 14b is inserted from the top to the bottom in the order of the small diameter insertion hole 32b, the first punch insertion hole 10b, and the second punch insertion hole 12a. Furthermore, the lower surface of the small-diameter punch portion 14 b faces the upper surface of the metal plate 2.
The length and thickness of the small-diameter punch portion 14 b are set to values corresponding to the shape of the hollow pin formed on the metal plate 2.

As described above, the punch 14 is inserted into the second punch insertion hole 12a of the stripper plate 12 so as to be movable in the vertical direction.
The pin support spring 16 is disposed in the upper mold recess 4a, and its expansion / contraction direction is directed in the vertical direction. Further, the upper end portion of the pin support spring 16 is seated on the bottom surface of the upper mold recess 4a. In the first embodiment, a case where the pin support spring 16 is formed of a coil spring will be described as an example.

The support pin 18 is formed in a columnar shape having a plurality of steps having different outer diameters, and includes a large-diameter pin portion 18a and a small-diameter pin portion 18b.
The large-diameter pin portion 18a is disposed in the upper mold recess 4a, and the lower end portion of the pin support spring 16 is seated on the upper surface thereof.
The small diameter pin portion 18b is formed to have a smaller diameter than the large diameter pin portion 18a, and extends downward from the lower surface of the large diameter pin portion 18a. The small-diameter pin portion 18b is inserted from the top to the bottom in the order of the first upper mold insertion hole 6a, the second upper mold insertion hole 8a, and the third upper mold insertion hole 10a. Further, the lower end surface of the small diameter pin portion 18 b faces the upper surface of the stripper plate 12.

The lower die set 20 is fixed to a base or the like not shown, and has a lower die recess 20a therein. The lower mold recess 20 a is a recess that opens on the upper surface of the lower die set 20.
The lower mold backing plate 22 is attached to the upper surface of the lower mold set 20 and has a first lower mold insertion hole 22a. The first lower mold insertion hole 22a is a through hole that penetrates the lower mold backing plate 22 in the vertical direction, and is formed in the lower mold backing plate 22 at a position that matches the lower mold recess 20a.

The die plate 24 is attached to the upper surface of the lower mold backing plate 22 and has a second lower mold insertion hole 24a. The second lower mold insertion hole 24a is a through-hole penetrating the die plate 24 in the vertical direction. Among the die plate 24, the second punch insertion hole 12a and the first lower mold insertion hole 22a are vertically centered. It is formed at a position that matches when viewed from the direction.
The inner diameter of the second lower mold insertion hole 24a is smaller than that of the large-diameter knockout portion 28a of the knockout 28 and larger than that of the small-diameter punch portion 14b. In addition, the description regarding the large diameter knockout part 28a is mentioned later.

Here, the inner diameter of the second lower mold insertion hole 24a is set according to the plate thickness of the portion constituting the side surface of the hollow pin. That is, the plate thickness of the portion constituting the side surface of the hollow pin is determined by the gap formed between the second lower mold insertion hole 24a and the small diameter punch portion 14b.
Further, the upper surface of the die plate 24 faces the lower surface of the metal plate 2. That is, the die plate 24 is disposed below the stripper plate 12 and faces the stripper plate 12 with the metal plate 2 interposed therebetween.

  The knockout spring 26 is disposed in the lower mold recess 20a and the first lower mold insertion hole 22a, and the expansion / contraction direction thereof is directed in the vertical direction. In the first embodiment, as an example, the case where the knockout spring 26 is formed of a gas spring using high-pressure gas will be described. However, the knockout spring 26 may be formed of a coil spring, for example.

Similarly to the support pin 18, the knockout 28 is formed in a cylindrical shape having a plurality of steps having different outer diameters, and includes a large-diameter knockout portion 28a and a small-diameter knockout portion 28b.
The large-diameter knockout portion 28a is disposed in the first lower mold insertion hole 22a and seals the gas constituting the knockout spring 26 in the lower mold recess 20a and the first lower mold insertion hole 22a. That is, the large-diameter knockout part 28a has a sealing performance in the lower mold recess 20a and the first lower mold insertion hole 22a.

The small-diameter knockout portion 28b is formed with a smaller diameter than the large-diameter knockout portion 28a, and extends upward from the upper surface of the large-diameter knockout portion 28a. The small-diameter knockout portion 28 b is inserted into the second lower mold insertion hole 24 a and is disposed in the first lower mold insertion hole 22 a according to the expansion and contraction of the knockout spring 26.
The length of the small-diameter knockout portion 28b is such that the upper end surface of the small-diameter knockout portion 28b is flush with the upper surface of the die plate 24 when the knockout spring 26 is extended and the large-diameter knockout portion 28a is in contact with the lower surface of the die plate 24. Is set to a length.

  As described above, the knockout 28 is disposed in the second lower mold insertion hole 24a of the die plate 24 so as to face the punch 14, and moves in the second lower mold insertion hole 24a in the vertical direction.

(Detailed configuration of plate lock mechanism)
Hereinafter, the detailed configuration of the plate lock mechanism 30 will be described with reference to FIG. 1 and FIGS. 2 to 4.
FIG. 2 is an enlarged view of the area surrounded by a circle II in FIG. 1 and its surroundings, and shows a detailed configuration of the plate lock mechanism 30. 3 is a view taken along the line III in FIG. 2, and FIG. 4 is a view taken along the line IV in FIG. In FIGS. 2 to 4, a part is broken for the sake of explanation.

As shown in FIGS. 2 to 4, the plate lock mechanism 30 includes an upper die cam driver 34, a lower die cam driver 36, a cam slider 38, and a cam guide block 40.
The upper mold cam driver 34 is formed of an upper mold cam main body 34a and a downward extending portion 34b.

  The upper die cam body 34a is positioned by the upper die cam driver positioning knock pin 42, and the side surface of the punch plate 8 (the left and right sides in FIG. 1) using the upper die cam driver fixing screw 44. Is attached. Thus, the upper die cam driver 34 is arranged so as to move in the vertical direction as the upper die set 4 moves in the vertical direction (vertical direction in FIG. 1).

The downward extension 34b extends below the punch plate 8 from the upper cam body 34a.
Further, an upper cam driver projecting portion 46 projecting from this surface toward the cam slider 38 is provided on the surface of the downwardly extending portion 34 b facing the cam slider 38. The detailed configuration of the upper cam driver protrusion 46 will be described later.

The lower mold cam driver 36 is formed of a lower mold cam main body 36a and an upper extension 36b.
The lower die cam body 36a is positioned by the lower die cam driver positioning knock pin 48, and the side surface of the die plate 24 (the left and right sides in FIG. 1) using the lower die cam driver fixing screw 50. Is attached.

The upper extending portion 36b extends below the die plate 24 from the lower mold cam main body 36a.
Further, a lower cam driver protruding portion 52 that protrudes from this surface toward the cam slider 38 is provided on the surface of the upper extending portion 36 b that faces the cam slider 38.
The lower mold cam driver protrusion 52 is formed so that the protrusion amount is the same as the protrusion amount of the upper cam driver protrusion 46.

The detailed configuration of the lower cam driver protrusion 52 will be described later.
Further, the upper extension portion 36b is disposed at a position farther from the stripper plate 12 than the lower extension portion 34b.
The cam slider 38 is held by the cam guide block 40 and is disposed on the side surface (left and right surfaces in FIG. 1) of the stripper plate 12 via the cam guide block 40.

Thereby, the cam slider 38 is arranged so as to move in the vertical direction as the upper die set 4 moves in the vertical direction. Note that the holding of the cam slider 38 by the cam guide block 40 will be described later.
Further, as will be described later, the cam slider 38 is disposed at a position where it engages with the upper die cam driver 34 or the lower die cam driver 36 in accordance with the rising and lowering of the upper die set 4.

The cam slider 38 is provided with a cam slider protruding portion 54 and a cam slider operating pin 56.
The cam slider protrusion 54 is provided on a surface of the cam slider 38 facing the upper mold main body 34a and the lower mold main body 36a. From this surface, the upper mold main body 34a and the lower cam main body 34a are provided. Projecting toward the portion 36a.

Further, the cam slider protruding portion 54 is formed so that the protruding amount thereof is the same as the protruding amounts of the lower die cam driver protruding portion 52 and the upper die cam driver protruding portion 46.
The detailed configuration of the cam slider protrusion 54 will be described later.
The cam slider actuating pin 56 projects from the surface opposite to the cam slider projecting portion 54 in the direction opposite to the cam slider projecting portion 54, and a pedestal portion 56 a having a larger diameter than other portions between the end portions. have.

The cam guide block 40 is attached to the side surface (left and right surfaces in FIG. 1) of the stripper plate 12 using the cam guide block fixing screw 60 in a state where the cam guide block 40 is positioned by the cam guide block positioning knock pin 58. Yes.
The cam guide block 40 has an opening that penetrates the cam guide block 40 in the vertical direction. The upper mold body 34a and the lower mold body 36a are inserted into the opening so as to be movable in the vertical direction, and the cam slider 38 is disposed so as to be movable along the side surface of the stripper plate 12. Has been.

(Cam slider holding structure with cam guide block)
Next, the holding structure of the cam slider 38 by the cam guide block 40 will be described.
When the cam slider 38 is held, the cam slider 38 is disposed in the opening of the cam guide block 40, and the portions of the opening that overlap the cam slider 38 as viewed from above and below are respectively cam sliders. The guide plate 62 is closed. At this time, the cam slider guide plate 62 is attached to the cam guide block 40 using a cam slider guide plate fixing screw 64.

In addition, in the cam guide block 40, the cam slider operating spring 66 is provided at a portion of the cam slider operating pin 56 on the tip end side (opposite to the protruding direction of the cam slider protruding portion 54) of the base portion 56 a. Place. Specifically, this arrangement is performed by seating one end of the cam slider operating spring 66 on the pedestal 56a.
Then, the end of the cam slider operating spring 66 opposite to the end seated on the pedestal 56 a is compressed by the spring pressing plate 68. Further, a spring pressing plate 68 compressing the cam slider operating spring 66 is attached to the cam guide block 40 by using a spring pressing plate fixing screw 70.

  As a result, the cam slider 38 is held by the cam guide block 40 in a state of being pressed and urged toward the upper cam driver protrusion 46 and the lower cam driver protrusion 52 along the side surface of the stripper plate 12. The

(Detailed configuration of upper cam driver protrusion, lower cam driver protrusion, cam slider protrusion)
Next, the detailed configuration of the upper mold cam driver protrusion 46, the lower cam driver protrusion 52, and the cam slider protrusion 54 will be described.

The upper die cam driver protrusion 46 has an upper die cam inclined surface 46a and an upper die cam horizontal surface 46b.
The upper die cam inclined surface 46a is continuous with the lower end surface of the lower extending portion 34b, and the cam slider 38 increases from the lower side (in the direction of the lower die set 20) toward the upper side (in the direction of the upper die set 4). It is formed to be inclined in a direction approaching.

The upper die horizontal surface 46b is formed above the upper die cam inclined surface 46a, and is formed horizontally along the moving direction of the cam slider 38. An upper cam chamfer 46c is provided between the upper cam inclined surface 46a and the upper cam horizontal surface 46b, and the upper cam inclined surface 46a and the upper cam horizontal surface 46b are connected to each other. It continues through the part 46c.
The lower die cam driver protrusion 52 has a lower die cam first inclined surface 52a and a lower die cam second inclined surface 52b.

The lower die cam first inclined surface 52a is continuous with the upper end surface of the upper extending portion 36b, and the cam extends from the upper side (in the direction of the upper die set 4) toward the lower side (in the direction of the lower die set 20). It is formed to be inclined in a direction approaching the slider 38.
The lower die cam second inclined surface 52b is formed below the lower die cam first inclined surface 52a, and goes from above (in the direction of the upper die set 4) to below (in the direction of the lower die set 20). In this case, it is formed to be inclined in a direction away from the cam slider 38. A lower mold cam chamfer 52c is provided between the lower cam first inclined surface 52a and the lower cam second inclined surface 52b, and the lower cam first inclined surface 52a and the lower cam first The two inclined surfaces 52b are continuous via the lower mold cam chamfered portion 52c.

The cam slider protrusion 54 has a slider inclined surface 54a and a slider horizontal surface 54b.
The slider inclined surface 54a approaches the upper die cam driver protrusion 46 and the lower die cam driver protrusion 52 from the upper side (the direction of the upper die set 4) toward the lower side (the direction of the lower die set 20). It is formed to be inclined. The direction approaching the upper cam driver 34 and the lower cam driver 36 is the right direction in FIG.

Further, the inclination angle of the slider inclined surface 54a is set to an angle that allows surface contact with the upper die cam inclined surface 46a and the lower die cam second inclined surface 52b.
The slider horizontal surface 54b is formed below the slider inclined surface 54a, and is formed horizontally along the moving direction of the cam slider 38. That is, the slider horizontal plane 54b is a plane parallel to the upper cam horizontal plane 46b. A slider chamfer 54c is provided between the slider inclined surface 54a and the slider horizontal surface 54b, and the slider inclined surface 54a and the slider horizontal surface 54b are continuous via the slider chamfered portion 54c.

(Composition of stock line pin)
A stock line pin 72 shown in FIG. 3 is a member that holds the metal plate 2 and protrudes from the upper surface of the die plate 24.
Specifically, the stock line pin 72 is disposed in a space formed in the lower mold backing plate 22, which has a small diameter portion inserted through the through hole of the die plate 24 and a larger diameter than the small diameter portion. It has a large diameter part.
The small diameter portion is formed with a material holding groove 72a that is continuous with the outer peripheral surface. The material holding groove 72a is formed with a depth and a vertical width that can hold the end of the metal plate 2 in the width direction. Yes.

  The large-diameter portion is formed continuously with the lower end surface of the small-diameter portion, and is pressed upward by a coil spring that expands and contracts in the vertical direction in the space formed in the lower mold backing plate 22 and Is arranged in. Thereby, the stock line pin 72 protrudes from the upper surface of the die plate 24 in a state in which the stock line pin 72 is movable in the vertical direction. Although not particularly illustrated, a recess that can accommodate the upper end side of the stock line pin 72 (portion protruding from the upper surface of the die plate 24) is opened on the lower surface of the stripper plate 12.

(Operation)
Next, the operation of the forging pin unloading mold 1 will be described with reference to FIGS. 1 to 4 and FIGS. 5 to 12.
The pinning process performed using the die 1 for forging pinning process having the above-described configuration includes a material holding process, a hollow pin forming process that is a subsequent process of the material holding process, and a stress that is a subsequent process of the hollow pin forming process. And a material removal step which is a subsequent step of the reduction step and the stress reduction step.

(Operation in material holding process)
Hereinafter, the operation of the forging pin unloading mold 1 in the material holding step will be described.
The material holding process is a process of holding the conveyed metal plate 2 between the stripper plate 12 and the die plate 24. The material holding step is performed from a state in which the upper die set 4 is raised and a gap is left between the stripper plate 12 and the die plate 24 (see FIG. 1). In addition to this, the material holding step is performed from a state in which the pin support spring 16 is extended and a gap is left between the punch plate 8 and the stripper backing plate 10 (see FIG. 1).

FIG. 5 is a view showing a state of the forging pin unloading die 1 and the metal plate 2 in the material holding step. In FIG. 5, the detailed configuration of the plate lock mechanism 30 is omitted as in FIG. FIG. 6 is a view taken along the line VI in FIG. 5 and shows a detailed operation of the plate lock mechanism 30.
As shown in FIGS. 5 and 6, in the material holding step, the upper die set 4 is lowered, and the conveyed metal plate 2 is pressed from above by the stripper plate 12, and the stripper plate 12 and the die plate 24 are pressed. Thus, the metal plate 2 is held while being sandwiched from above and below. Thereby, it is possible to improve the positioning accuracy in the pinning process by suppressing the displacement of the position where the hollow pin is formed with respect to the metal plate 2.

At this time, the amount by which the upper die set 4 is lowered is an amount that is maintained in a state where the pin support spring 16 is extended. As a result, the punch 14 does not protrude from the lower surface of the stripper plate 12.
Therefore, in the material holding step, neither the punch 14 nor the knockout 28 applies a force for deforming the metal plate 2 to the metal plate 2. In the material holding step, the upper cam inclined surface 46a and the slider inclined surface 54a are in surface contact with each other.

  When the metal plate 2 is sandwiched and held between the stripper plate 12 and the die plate 24 from the vertical direction, the pinning process performed using the die 1 for forging pinning process shifts from the material holding process to the hollow pin forming process.

(Operation in the hollow pin forming process)
Hereinafter, operation | movement of the metal mold | die 1 for a forge pin extraction process in a hollow pin formation process is demonstrated.
The hollow pin forming step is a step of forming a hollow pin on the metal plate 2 held between the stripper plate 12 and the die plate 24 in the material holding step. In addition, the hollow pin forming step is a step of connecting the punch 14 and the stripper plate 12 so as to move upward together.

  FIG. 7 is a view showing a state of the forging pin unloading die 1 and the metal plate 2 in the hollow pin forming step. In FIG. 7, the detailed configuration of the plate lock mechanism 30 is omitted as in FIG. FIG. 8 is a view taken along the line VIII in FIG. 7 and shows a detailed operation of the plate lock mechanism 30.

As shown in FIGS. 7 and 8, in the hollow pin forming step, the upper die set 4 is further lowered from the position lowered in the material holding step. As a result, the extending pin support spring 16 and the coil spring used to attach the stripper plate 12 are contracted to bring the punch plate 8 into contact with the stripper backing plate 10.
When the upper die set 4 is lowered, the pin support spring 16 contracts, and the small-diameter punch portion 14 b protrudes downward from the second punch insertion hole 12 a and protrudes from the lower surface of the stripper plate 12. When the small-diameter punch portion 14 b protrudes from the lower surface of the stripper plate 12, the punch 14 applies a pressing force to the upper surface of the metal plate 2 disposed on the die plate 24.

At this time, the punch 14 that applies a pressing force to the upper surface of the metal plate 2 pushes the metal plate 2 disposed on the die plate 24 into the second lower mold insertion hole 24a from above.
Further, the knockout 28 facing the metal plate 2 with the metal plate 2 in between is pressed downward together with the metal plate 2 by the pressing force applied by the punch 14 to the upper surface of the metal plate 2, and the second lower mold insertion hole While descending the inside of 24a, the knockout spring 26 is compressed from above.

At this time, since the compressed knockout spring 26 contracts (shrinks) in a state of having an elastic force, the knockout 28 descends in the second lower mold insertion hole 24a, and the back of the metal plate 2 is raised upward. Apply pressure.
Therefore, when the upper die set 4 is further lowered from the lowered position in the material holding step, the metal plate 2 sandwiched between the lowered punch 14 and the knockout 28 protrudes downward from the lower surface of the metal plate 2. A hollow pin P is formed.

  Further, when the upper die set 4 is lowered so that the punch plate 8 contacts the stripper backing plate 10, the distance between the stripper plate 12 and the punch plate 8 decreases. As a result, the upper die cam driver 34 descends and the upper die cam inclined surface 46a presses the slider inclined surface 54a.

  Here, when the upper mold cam inclined surface 46a presses the slider inclined surface 54a, the pressing force by the upper mold cam driver 34 is applied to the cam slider 38, and the cam slider operating spring 66 contracts. When the cam slider operating spring 66 contracts, the cam slider 38 pressed by the upper cam driver 34 moves in a direction away from the upper cam driver 34 (leftward in FIG. 8).

  When the upper cam driver 34 descends and the cam slider 38 moves away from the upper cam driver 34, the upper cam inclined surface 46a and the upper cam chamfer 46c move downward relative to the slider inclined surface 54a. To do. Thereby, the upper mold cam inclined surface 46a and the upper mold cam chamfered portion 46c move downward in the order of the slider chamfered portion 54c and the slider horizontal surface 54b below the slider chamfered portion 54c and the slider horizontal surface 54b.

When the upper mold cam inclined surface 46a and the upper mold cam chamfered portion 46c move below the slider horizontal plane 54b, the pressing force applied to the cam slider 38 by the upper mold cam driver 34 disappears. Then, the contracted cam slider operating spring 66 extends to the original length.
When the cam slider operating spring 66 extends to the original length, the cam slider 38 moves in a direction approaching the upper cam driver 34 (rightward in FIG. 8), and the cam slider protruding portion 54 is moved to the upper mold. It moves above the cam driver protrusion 46.

  When the cam slider protrusion 54 moves above the upper cam driver protrusion 46, as shown in FIG. 8, the slider horizontal surface 54b and the upper cam horizontal surface 46b face each other in the vertical direction. 34 and the cam slider 38 are engaged with each other. The state in which the slider horizontal plane 54b and the upper mold horizontal plane 46b face each other in the vertical direction and the upper mold cam driver 34 and the cam slider 38 are engaged with each other is separated even if the slider horizontal plane 54b and the upper mold horizontal plane 46b are in contact with each other. You may do it.

When the slider horizontal surface 54b and the upper die cam horizontal surface 46b are opposed to each other in the vertical direction and the upper die cam driver 34 and the cam slider 38 are engaged with each other, the punch plate 8 and the stripper plate 12 are connected so as to move upward. Is done. Thereby, both the punch 14 and the stripper plate 12 are connected so as to move upward.
As described above, the plate lock mechanism 30 connects the punch 14 and the stripper plate 12 together so as to move upward. This connection is performed in a state where the small-diameter punch portion 14b protruded downward from the second punch insertion hole 12a pushes the metal plate 2 disposed on the die plate 24 into the second lower mold insertion hole 24a.

  When the punch 14 and the stripper plate 12 are both connected so as to move upward, the pinning process performed using the die 1 for forging pinning process shifts from the hollow pin forming process to the stress reducing process.

(Operation in the stress reduction process)
Hereinafter, the operation of the die 1 for forging pinning process in the stress reduction process will be described.
In the stress reduction step, the upper die set 4 is raised to raise the members integrated with the upper die set 4 in the vertical direction, and the metal plate 2 on which the hollow pin P is formed is raised. It is a process. Here, the members integrated with the upper die set 4 in the vertical direction are the stripper backing plate 10, the stripper plate 12, the punch 14, the upper die cam driver 34, and the cam slider 38.

FIG. 9 is a diagram showing a state of the forging pin unloading die 1 and the metal plate 2 in the stress reduction process. In FIG. 9, the configuration of the plate lock mechanism 30 is omitted as in FIG. FIG. 10 is a view taken in the direction of the X-ray in FIG. 9 and shows a detailed operation of the plate lock mechanism 30.
As shown in FIGS. 9 and 10, in the stress reduction step, the upper die backing plate 6 and the punch plate 8 are raised by raising the upper die set 4.

At this time, since the punch 14 and the stripper plate 12 are connected together so as to move upward by the plate lock mechanism 30 in the hollow pin forming step which is the previous step, the stripper is moved as the punch plate 8 rises. The plate 12 rises.
Specifically, since the slider horizontal plane 54b and the upper mold horizontal plane 46b face each other in the vertical direction, when the punch plate 8 rises and the upper mold cam driver 34 rises, the upper mold cam is moved with respect to the slider horizontal plane 54b. An upward pressing force is applied from the horizontal plane 46b.

When an upward pressing force is applied to the slider horizontal surface 54b, the cam slider 38 is lifted by the pressing force, and the stripper plate 12 is lifted.
Further, the lower surface of the large diameter punch portion 14a faces the bottom surface of the large diameter arrangement portion 32a. For this reason, when the punch plate 8 rises, the punch 14 rises together with the punch plate 8 and the stripper plate 12 while being held by the punch plate 8.

  Here, in the outer peripheral surface of the punch 14 that is pushing the metal plate 2 into the second lower mold insertion hole 24a, the metal plate 2 is hollow due to the deformation of the metal plate 2 that occurs when the hollow pin P is formed. Stress toward the central axis side of the punch 14 is applied from the portion where the pin P is formed. The stock line pin 72 holding the metal plate 2 is pressed and urged upward by a stock line pin spring (not shown) that can be expanded and contracted in the vertical direction.

For this reason, when the punch 14 is lifted together with the punch plate 8 and the stripper plate 12, the metal plate 2 is also inserted into the hollow portion of the hollow pin P formed in the hollow pin forming step with the rise. To rise.
That is, when both the punch plate 8 and the stripper plate 12 are raised, the punch 14 that pushes the metal plate 2 into the second lower mold insertion hole 24a is also raised.

When the metal plate 2 rises with the punch 14 inserted into the hollow portion of the hollow pin P, the contracted knockout spring 26 expands (extends) with the rise of the punch 14 and returns to the original volume. Knockout 28 rises.
Since the knockout 28 is raised while the punch 14 is inserted into the hollow portion of the hollow pin P, the punch 14 inserted into the hollow portion of the hollow pin P is moved from the rising knockout 28 to the bottom surface of the hollow pin P. A reaction force against the stress due to the applied back pressure is generated. As a result, the formed hollow pin P is reduced in a state where stress due to back pressure applied from the knockout 28 to the bottom surface of the formed hollow pin P is reduced by the punch 14 pushed into the second lower mold insertion hole 24a. It can be extracted from the lower mold insertion hole 24a.

Therefore, even if the knockout 28 applies stress due to the back pressure to the metal plate 2, the hollow portion of the hollow pin P is not sandwiched between the stripper plate 12 and the knockout 28, and the hollow pin P is crushed. It becomes possible to prevent the deformation of.
As described above, in the stress reduction step, both the punch 14 and the stripper plate 12 are moved upward. This movement is performed in a state in which the small-diameter punch portion 14b protruding downward from the second punch insertion hole 12a pushes the metal plate 2 disposed on the die plate 24 into the second lower mold insertion hole 24a.

As a result, in the stress reduction step, stress due to back pressure applied from the knockout 28 to the bottom surface of the hollow pin P when the formed hollow pin P is extracted is applied from the knockout 28 to the bottom surface of the hollow pin P when the hollow pin P is formed. Reduce than stress due to back pressure.
Further, as described above, the plate lock mechanism 30 includes the punch 14 and the stripper plate 12 in a state where the small diameter punch portion 14b pushes the metal plate 2 disposed on the die plate 24 into the second lower mold insertion hole 24a. Are connected together so as to move upward.

  For this reason, the forging pin die 1 is formed by applying stress due to back pressure applied from the knockout 28 to the bottom surface of the hollow pin P when the formed hollow pin P is extracted, and from the knockout 28 to the hollow pin when forming the hollow pin P. A stress reduction mechanism that reduces the stress due to the back pressure applied to the bottom surface of P is provided. That is, the plate lock mechanism 30 forms part of the stress reduction mechanism together with other components such as the stripper plate 12 and the punch 14.

  When the upper die set 4 is raised and the formed hollow pin P is extracted from the second lower die insertion hole 24a, the pinning process performed using the forging pin unloading mold 1 is performed by removing the material from the stress reduction process. Move to the process. In this state, the upper cam driver 34 and the cam slider 38 are engaged with each other.

(Operation in material removal process)
Hereinafter, the operation of the forging pin unloading mold 1 in the material removing process will be described.
In the material removal step, the upper die set 4 is further raised from the position where it is raised in the stress reduction step, and the punch 14 is extracted from the hollow portion of the hollow pin P, and the metal plate 2 on which the hollow pin P is formed is removed. This is a step of removing from the stripper plate 12.

  FIG. 11 is a view showing a state of the forging pin unloading die 1 and the metal plate 2 in the material removing step. In FIG. 11, the configuration of the plate lock mechanism 30 is omitted as in FIG. 12 is a view taken in the direction of arrow XII in FIG. 11 and shows a detailed operation of the plate lock mechanism 30. FIG.

As shown in FIGS. 11 and 12, in the material removal step, the upper die set 4 is further raised from the position raised in the stress reduction step, so that the upper die cam driver 34 and the cam slider 38 are moved. Release the mesh.
Specifically, the upper die set 4 is raised to raise the upper die cam driver 34 and the cam slider 38, and the cam slider protrusion 54 is brought into contact with the lower die cam driver protrusion 52 from below.

When the cam slider protrusion 54 is brought into contact with the lower cam driver protrusion 52 from below, the slider inclined surface 54a comes into surface contact with the lower cam second inclined surface 52b. Then, the cam slider protrusion 54 rises while the slider inclined surface 54a is pressed against the lower mold second cam inclined surface 52b.
Here, when the slider inclined surface 54a is pressed against the lower cam second inclined surface 52b, the pressing force by the lower cam driver 36 is applied to the cam slider 38, and the cam slider operating spring 66 contracts. When the cam slider operating spring 66 contracts, the cam slider 38 pressed by the lower mold driver 36 moves in a direction away from the lower mold driver 36 (leftward in FIG. 12).

When the upper mold cam driver 34 moves upward and the cam slider 38 moves away from the lower mold cam driver 36, the slider inclined surface 54a that is in contact with the lower mold cam second inclined surface 52b becomes the lower mold cam first. It moves upward toward the inclined surface 52a.
When the slider inclined surface 54a moving upward toward the lower mold cam first inclined surface 52a comes into contact with the lower mold cam chamfered portion 52c, the slider horizontal plane 54b and the upper mold cam horizontal plane 46b facing each other in the vertical direction are separated from each other. . As a result, the engagement between the upper die cam driver 34 and the cam slider 38 is released, so that the upper die cam driver 34 rises independently from the cam slider 38.

In a state where the upper die driver 34 is lifted independently from the cam slider 38, when the upper die set 4 is raised, the coil spring used to attach the stripper plate 12 is extended. For this reason, only the punch plate 8 of the punch plate 8 and the stripper plate 12 rises.
Then, when the upper die set 4 continues to rise and the punch plate 8 rises, the punch 14 rises in the second punch insertion hole 12a and is extracted upward from the hollow portion of the hollow pin P. In this state, the cam slider 38 is disposed above the lower die cam driver 36, and the cam slider 38 and the lower die cam driver 36 are not in contact with each other.

  When the punch 14 is extracted upward from the hollow portion of the hollow pin P, the metal plate 2 on which the hollow pin P is formed is easily peeled off from the lower surface of the stripper plate 12, and can be easily removed from the stripper plate 12. Become. Then, when the punch 14 is extracted upward from the hollow portion of the hollow pin P and the metal plate 2 on which the hollow pin P is formed is removed from the lower surface of the stripper plate 12, the material removal step is completed.

(Transition from material removal process to material holding process)
When shifting from the state where the material removal process is completed to the material holding process, the cam slider protrusion 54 is positioned below the lower cam driver protrusion 52.
Specifically, first, the upper die set 4 is lowered in a state where the pin support spring 16 extends and a gap is left between the punch plate 8 and the stripper backing plate 10.
When the upper die set 4 is lowered while the pin support spring 16 is extended, and the stripper plate 12 is lowered, the cam slider 38 is lowered, and the cam slider protrusion 54 becomes the lower cam driver protrusion 52. Contact from above.

  When the cam slider protrusion 54 contacts the lower cam driver protrusion 52 from above, the slider chamfer 54c contacts the lower cam first inclined surface 52a. Then, the cam slider 38 is lowered while the slider chamfer 54c is pressed against the lower cam first inclined surface 52a.

  Here, when the slider chamfer 54c is pressed against the lower cam first inclined surface 52a, the pressing force by the lower cam driver 36 is applied to the cam slider 38, and the cam slider operating spring 66 contracts. When the cam slider operating spring 66 contracts, the cam slider 38 pressed by the lower mold driver 36 moves in a direction away from the lower mold driver 36 (leftward in FIG. 12).

When the cam slider 38 moves down and moves away from the lower cam driver 36, the slider chamfered portion 54c in contact with the lower cam first inclined surface 52a contacts the lower cam chamfered portion 52c.
When the cam slider 38 is further lowered from the state in which the slider chamfered portion 54c is in contact with the lower mold cam chamfered portion 52c, the cam slider 38 is lowered while the slider inclined surface 54a is in contact with the lower mold cam second inclined surface 52b. .

When the cam slider 38 continues to descend, the slider inclined surface 54a moves below the lower mold cam second inclined surface 52b, and the cam slider protruding portion 54 moves below the lower mold cam driver protruding portion 52. Moving.
As described above, the die 1 for forging pin machining according to the first embodiment applies stress due to the back pressure applied from the knockout 28 to the bottom surface of the hollow pin P when the formed hollow pin P is extracted by the stress reduction mechanism. When the hollow pin P is formed, the stress due to the back pressure applied from the knockout 28 to the bottom surface of the hollow pin P is reduced.

Therefore, in this invention, it becomes possible to suppress the deformation | transformation which arises in the formed hollow pin P by the back pressure from the knockout 28 added to the hollow pin P, and it becomes possible to improve the quality of a workpiece further. In addition, a processed product is the metal plate 2 in which the hollow pin P was formed, for example.
Further, in the present invention, since it becomes possible to suppress the deformation that occurs in the formed hollow pin P, it is possible to suppress damage such as crushing caused by the deformation of the hollow pin P, the shape of the formed hollow pin P, It becomes possible to hold without changing, and the quality of the processed product can be further improved.

Further, the forged pin unloading die 1 according to the first embodiment is configured such that the metal plate 2 having the punch 14 disposed on the die plate 24 is inserted into the second lower die insertion hole 24a by the plate lock mechanism 30 included in the stress reduction mechanism. The punch 14 and the stripper plate 12 are connected while being pushed in.
Therefore, in the present invention, the punch 14 disposed in the inner space of the formed hollow pin P generates a reaction force against the stress due to the back pressure applied from the knockout 28 to the bottom surface of the hollow pin P when the formed hollow pin P is extracted. It becomes possible to make it.

  Thereby, in this invention, it becomes possible to suppress the deformation | transformation which arises in the formed hollow pin P by the back pressure from the knockout 28 added to the hollow pin P, without requiring the structure of an independent actuator etc., and processed goods It becomes possible to further improve the quality of the.

(Second embodiment)
In the first embodiment, the punch 14 and the stripper plate 12 are connected with the stress reduction mechanism in a state where the punch 14 pushes the metal plate 2 disposed on the die plate 24 into the second lower mold insertion hole 24a. The plate lock mechanism 30 is provided.
On the other hand, for example, when the formed hollow pin P is extracted, the back pressure applied to the hollow pin P by the knockout 28 may be reduced by controlling the pressure of the knockout spring 26.

  That is, when the hollow pin P is extracted from the second lower mold insertion hole 24a, the back pressure applied from the knockout 28 to the bottom surface of the hollow pin P is applied to the stress reducing mechanism. It is good also as a structure which has a back pressure reduction mechanism to reduce rather than the back pressure added to the bottom face of P. This is because, as in the first embodiment, the knockout spring 26 is formed of a gas spring using a fluid (gas) such as high-pressure gas, or an elastic member whose elastic force can be changed by electric power, magnetic force, or the like. Applicable.

Note that the back pressure reduction mechanism as described above has a configuration (air tank, pressure control valve, pressure control computer, etc.) capable of controlling the pressure (gas pressure) of the knockout spring 26, for example. In addition to this, a flow path is formed in the lower die set 20 to connect the lower die recess 20a and the pressure control valve.
When the stress reduction mechanism is configured to have a back pressure reduction mechanism, in the stress reduction process, the hollow pin P is applied from the knockout 28 to the bottom surface of the hollow pin P when the hollow pin P is extracted from the second lower mold insertion hole 24a. The back pressure is reduced more than the back pressure applied to the bottom surface of the hollow pin P from the knockout 28 when the hollow pin P is formed.

However, in this way, the configuration for controlling the pressure of the knockout spring 26 needs to greatly change the configuration of the forging pin unloading die 1 and causes a complicated control.
For this reason, as in the first embodiment, it is advantageous in terms of cost and the like that the stress reduction mechanism has the plate lock mechanism 30 as compared with the configuration in which the pressure of the knockout spring 26 is controlled.

  The stress reduction mechanism may include a plate lock mechanism 30 and a configuration that controls the pressure of the knockout spring 26.

DESCRIPTION OF SYMBOLS 1 Die for forging pin processing, 2 Metal plate, 4 Upper die set, 4a Upper die recessed part, 6 Upper die backing plate, 6a 1st upper die insertion hole, 8 Punch plate, 8a 2nd upper die insertion hole, 10 stripper backing plate, 10a third upper mold insertion hole, 10b first punch insertion hole, 12 stripper plate, 12a second punch insertion hole, 14 punch, 14a large diameter punch section, 14b small diameter punch section, 16 pin support spring, 18 Support pin, 18a Large-diameter pin portion, 18b Small-diameter pin portion, 20 Lower die set, 20a Lower die recess, 22 Lower die backing plate, 22a First lower die insertion hole, 24 Die plate, 24a Second lower die insertion Hole, 26 Knockout Spring, 28 Knockout, 28a Large Diameter Knockout, 28b Small Diameter Knockout , 30 Plate lock mechanism, 32 Punch arrangement hole, 32a Large diameter arrangement part, 32b Small diameter insertion hole, 34 Upper cam driver, 34a Upper cam body part, 34b Lower extension part, 36 Lower cam driver, 36a Lower mold Cam body, 36b upward extension, 38 cam slider, 40 cam guide block, 42 upper cam driver positioning knock pin, 44 upper cam driver fixing screw, 46 upper cam driver protrusion, 46a upper cam inclined surface, 46b Upper cam horizontal surface, 46c Upper cam chamfer, 48 Lower cam driver positioning knock pin, 50 Lower cam driver fixing screw, 52 Lower cam driver protrusion, 52a Lower cam first inclined surface, 52b Lower cam Second inclined surface, 52c Lower mold cam chamfer, 54 Cam slider protrusion, 5 4a Slider inclined surface, 54b Slider horizontal surface, 54c Slider chamfer, 56 Cam slider operation pin, 56a Base, 58 Cam guide block positioning knock pin, 60 Cam guide block fixing screw, 62 Cam slider guide plate, 64 Cam slider guide plate Fixing screw, 66 Cam slider spring, 68 Spring holding plate, 70 Spring holding plate fixing screw, 72 Stock line pin, 72a Material holding groove, P Hollow pin

Claims (6)

A die plate having a through-hole penetrating in the vertical direction;
A punch that pushes the metal plate disposed on the die plate into the through-hole of the die plate from above,
The metal plate is disposed in the through hole of the die plate so as to face the punch and is pressed by the punch that pushes the metal plate into the through hole of the die plate and descends through the through hole of the die plate. A knockout that applies a back pressure upward to form a hollow pin protruding from the metal plate;
The stress due to the back pressure applied from the knockout to the bottom surface of the hollow pin when the hollow pin is extracted from the through hole of the die plate, and the back pressure applied from the knockout to the bottom surface of the hollow pin when the hollow pin is formed. A die for forging pin machining, comprising: a stress reduction mechanism that reduces the stress due to stress. A stripper plate having a through-hole penetrating in the vertical direction and sandwiching the metal plate with the die plate;
The punch is inserted into a through hole of the stripper plate,
The stress reduction mechanism includes a plate lock mechanism that connects the punch and the stripper plate in a state where the punch pushes a metal plate disposed on the die plate into a through hole of the die plate. A die for forging pinning processing according to claim 1.   The stress reducing mechanism applies back pressure applied from the knockout to the bottom surface of the hollow pin when the hollow pin is extracted from the through hole of the die plate, and the bottom surface of the hollow pin from the knockout when the hollow pin is formed. 3. A die for forging pinning processing according to claim 1 or 2, further comprising a back pressure reducing mechanism for reducing the back pressure applied to the forging pin. Knockout disposed opposite to the punch in the through hole of the die plate by punching the metal plate arranged on the die plate having the through hole penetrating in the vertical direction into the through hole of the die plate from above. A hollow pin forming step of forming a hollow pin protruding from the metal plate by applying a back pressure upward to the metal plate while the pressed knockout descends the through hole of the die plate When,
The stress due to the back pressure applied from the knockout to the bottom surface of the hollow pin when the hollow pin is extracted from the through hole of the die plate, and the back pressure applied from the knockout to the bottom surface of the hollow pin when the hollow pin is formed. A forging pinning method comprising: a stress reduction step for reducing the stress due to stress. In the hollow pin forming step, the die plate is sandwiched between the stripper plate having a through hole penetrating in the vertical direction and the die plate by the punch inserted through the through hole of the stripper plate. Push into the through-hole
In the stress reduction step, the punch and the stripper plate are both moved upward in a state where the metal plate disposed on the die plate is pushed into a through hole of the die plate. A forging pin unloading method according to claim 4.   In the stress reduction step, the back pressure applied from the knockout to the bottom surface of the hollow pin when the hollow pin is extracted from the through hole of the die plate is applied to the bottom surface of the hollow pin from the knockout when the hollow pin is formed. The forging pin unloading method according to claim 4 or 5, wherein the forging pin unloading method according to claim 4 or 5 is reduced more than the back pressure applied to the surface.

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