JPH0354015B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a press die for drilling and burring a plate material, and in particular, a die assembly is disposed above and a punch assembly is disposed below. Regarding press dies for drilling and burring.

Conventional Technology Conventionally, when punching a hole using a press mold for making holes in which the die assembly is placed above and the punch assembly is placed below, the blanks punched from the plate material are placed on the plate material. In order to prevent the scraps from being scattered, the scraps were allowed to fall downward.

Problems to be Solved by the Invention However, in order to cause the scraps to fall downward as described above, the die assembly is first lowered to punch a pilot hole in the plate material, and then the die assembly is raised once. It was necessary to drop the punched blanks downward, and then lower the die assembly again to squeeze out the peripheral portion of the prepared hole in the plate material to form the hole flange. Therefore, both the punching of the prepared hole and the pressing out of the hole flange cannot be achieved by one downward movement of the die assembly, resulting in a significant decrease in work efficiency.

Therefore, in Utility Application No. 59-107867 and No. 59-107868, the present applicant has previously disclosed that by discharging the punched scraps upward to the die assembly side, there is no need for the punched scraps to fall downward, and the die - We have proposed a press die for drilling and burring that can accomplish both punching of the pilot hole and pressing out of the hole flange in one descending stroke of the assembly.

This press mold is provided with an ejector member (punch ejector) that moves up and down along a punch that is fixed at a fixed position, and an ejector spring that biases the ejector member upward. When the die assembly is lowered, it is pushed downward by the die assembly through the plate material, so that it descends together with the plate material against the ejector spring, causing the tip side of the punch to protrude from the ejector member. and,
After punching and burring a pilot hole in the plate material by the punch and die assembly, when the die assembly is raised again, the ejector member returns upward due to the spring force of the ejector spring, The plank was pushed back upwards.

However, in such a configuration, if the force of the ejector spring is weakened, even if the die assembly is raised after punching and burring the pilot hole in the plate material, the plate material remains stuck to the punch and does not separate. There was a problem in that the ejector spring was sometimes unable to raise the ejector member.

On the other hand, if the force of the ejector spring is increased, the die assembly must be lowered with a large force, resulting in the problem that impressions are created in the plate material when punching pilot holes. Furthermore, if a strong spring is attempted to be obtained by using a metal coil spring, there is a problem in that the spring becomes larger and, by extension, the punch assembly also becomes larger.
Furthermore, in order to avoid increasing the size of the ejector spring,
When a spring made of urethane rubber is used, the stroke of the ejector member is relatively large and the urethane rubber is greatly deformed, so there is a problem that the urethane rubber may crack.

Purpose of the Invention The present invention has been made to solve the above-mentioned conventional problems, and the die assembly is arranged above and the punch assembly is arranged below. Therefore, in a press die for drilling and burring that both punches a pilot hole in a plate material and presses out a hole flange, after punching a pilot hole in the plate material and burring it,
To provide a press die for drilling and burring that does not cause inconveniences such as a plate material remaining stuck to the punch and not being separated from the plate material even when the die assembly is raised, or indentations being formed on the plate material. purpose.

Means for Solving the Problems The press mold for drilling and burring according to the present invention includes a die body that is moved up and down by a press machine, a die hole provided in the die body, and a die assembly that is moved up and down by a press machine. A die chip that can be raised and lowered relative to the main body and whose lower end enters the die hole; a die chip hole provided at the lower end of the die chip; The punch assembly includes a punch fixed in a fixed position with the tip facing upward, and a diameter of the die tip hole formed at the tip of the punch. and a hole formed in the punch below the prepared hole forming part and having a diameter corresponding to the diameter of the die hole and the thickness of the plate material to be drilled and burred. a flange forming portion, an ejector member that is movable up and down, and provided on the ejector member, the tip side of the punch protrudes upward from the ejector member when the ejector member is pushed down by the die body through the plate material. a punch protruding hole that causes the die to be lowered to the vicinity of the bottom dead center; a first spring that biases the ejector member upward before the die body is lowered to the vicinity of the bottom dead center of the die body; and a second spring made of an elastomer such as urethane rubber having a stronger spring force than the first spring, which starts to be compressed by the ejector member and biases the ejector member upward. be.

Effect In the present invention, when the die body is lowered and the lower end surface of the die body comes into contact with the plate while the plate is placed on the upper part of the ejector member, the plate and the ejector member resist the first spring. and begins to descend. Then, since the punch is fixed and cannot be lowered, the pilot hole forming part of the punch first enters the die chip hole of the die, and the pilot hole is punched into the plate material.

When the die body further descends, the plate material and the ejector member further descend against the first spring,
The hole flange forming portion of the punch enters the die hole, and the peripheral portion of the pilot hole of the plate material is squeezed out to form a hole flange.

As the burring process progresses in this way, and when the die body reaches a predetermined position near its bottom dead center, the lower surface of the ejector member comes into contact with the upper surface of the second spring, compressing the second spring. Begin to.

When the die body reaches the bottom dead center, the hole flange portion is completely formed in the plate material, and the burring process is completed. Then, when the die body is raised, the ejector member is first pushed up by the strong spring force of the second spring, so even if the plate is biting into the punch, the plate is pulled away from the punch and rises. .

Embodiments Hereinafter, the present invention will be described based on embodiments shown in the drawings.

1 to 7 show one embodiment of the present invention. In this embodiment, die assembly 1 is constructed as follows.

A die head 4 is fixed to the upper end of the die guide 2 by a set screw 3. Furthermore, a die main body 5 is fixed to the lower end of the die guide 2 by bolts 30. A die chip 7 is housed in a space 6 formed inside the die guide 2 and the die body 5, and this die chip 7 is connected to a die collar 8 and a die collar 8 fixed inside the die body 5. It is fitted into the inner surface of the die body 5 so as to be movable up and down. A die hole 9 is provided at the lower end of the die body 5. Further, a protrusion 7a having an outer diameter corresponding to the die hole 9 is provided at the lower end of the die chip 7, and a die tip hole 10 passes through the protrusion 7a. The die tip hole 10 is a tapered hole whose diameter increases upwardly.

Inside the die tip 7, a punched waste storage portion 11 is provided continuously at the upper end of the die tip hole 10. Further, the die chip 7,
A die spring 12 made of a compression coil spring is interposed between the die collar 8 and the die spring 12, and this die spring 12 urges the die chip 7 downward.

Die assembly 1 configured as above
is punched and punched using a press machine (not shown) such as a numerically controlled turret punch press.
It is adapted to be raised and lowered above the assembly 13.

Next, the configuration of the punch assembly 13 will be explained. The bottom material 14, the intermediate member 15 and the holding member 16 are assembled together by means of a tightening bolt 17 to form a punch block 18. A tightening bolt 19 is attached to the intermediate member 15.
As a result, the punch 20 is fixed with its tip facing upward. The bottom member 14, intermediate member 15, presser member 16 and punch 20 are
It is designed to be fixed to the turret of a numerically controlled turret, punch press, etc. An ejector hole 21 is provided in the center of the presser member 16.

The punch 20 has, in order from its tip side to its lower end side, a prepared hole forming part 20a, a hole flange forming part 20b having a larger diameter than the prepared hole forming part 20a, a tapered part 20c, and a hole flange forming part larger than the hole flange forming part 20b. A large diameter portion 20d and a bottom portion 20e having a larger diameter than the large diameter portion 20d are formed. Further, a stepped portion is formed between the prepared hole forming portion 20a and the hole flange forming portion 20b. The pilot hole forming portion 20a has a diameter corresponding to the diameter of the lower end of the die tip hole 10, and the hole flange forming portion 20b has a diameter corresponding to the diameter of the lower end of the die tip hole 10.
Therefore, the diameter is smaller by a certain dimension corresponding to the thickness of the plate material 22 to be processed.

Reference numeral 23 denotes an ejector member that can be raised and lowered relative to the presser member 16. The upper end 23a of the ejector member 23 is tapered and can protrude above the presser member 16 from the ejector hole 21. The vertical intermediate portion 23b of the ejector member 23 has a cylindrical shape with a slightly smaller diameter than the ejector hole 21.
3, the ejector hole 21
It is becoming more and more guided by. Further, an ejector hole 21 is provided at the lower end of the ejector member 23.
A flange portion 23c with a larger diameter is formed,
This flange portion 23c is always accommodated in a space 24 formed between the holding member 16 and the intermediate member 15, and is adapted to prevent the ejector member 23 from coming off from the holding member 16. Further, a punch protruding hole 2 is provided in the ceiling of the ejector member 23.
5 is provided, and this punch protruding hole 25 has a diameter corresponding to the hole flange forming portion 20b of the punch 20, and the hole flange forming portion 20 of the punch 20 is formed during a part of the ejector member 23's lifting/lowering stroke.
It is designed to guide b.

As shown in FIGS. 3 and 5, the intermediate member 15 has four spring housing holes 26, and the bottom member 14 has four blind hole-like spring housings that are continuous with each spring housing hole 26. A hole 27 is provided. A first spring 28 made of a compression coil spring made of metal is interposed between the bottom of the spring housing hole 27 and the lower surface of the ejector member 23 so as to pass through the spring housing hole 26. The spring 28 urges the ejector member 23 upward. The intermediate member 1
A plate-shaped second spring 29 made of urethane rubber is placed on the upper surface of the spring 5 . This second spring 2
As shown in FIG. 3, 9 has a roughly cross-shaped shape that avoids the installation position of the first spring 28 so as not to interfere with the first spring 28. Further, the punch 20 passes through the center of the second spring 29.

The second spring 29 is stronger than the first spring 28. And ejector member 2
3 is the upper limit position (the flange part 23c is the presser member 16
A gap of a predetermined size is formed between the lower surface of the ejector member 23 and the second spring 29, so that the ejector member 23 When the die body 5 descends to a predetermined position (as described later, when the die body 5 descends to the vicinity of its bottom dead center), the ejector member 23
is lowered to this predetermined position), the lower surface of the ejector member 23 comes into contact with the upper surface of the second spring 29 for the first time.

Next, the operation of this embodiment will be explained.

In the initial state shown in FIG. 1, the ejector member 23 is biased to the upper limit position by the force of the first spring 28, and at this time, the punch 20
The upper end surface is located slightly below the upper end surface of the ejector member 23. Further, the die tip 7 is biased to the lower limit position with respect to the die guide 2 and the die body 5 by the force of the die spring 12, and at this time, the protrusion 7a of the die tip 7 is placed in the die hole 9.
The lower end surface of the protrusion 7a and the lower end surface of the die body 5 are at the same height.

Next, with the plate material 22 placed on the upper part of the ejector member 23, the die body 5 is lowered together with the die guide 2, and when the lower end surface of the die body 5 comes into contact with the plate material 22, the plate material 22 and the ejector member 23 begins to descend against the first spring 28. Then, since the punch 20 is fixed and cannot be lowered, the prepared hole forming part 20a of the punch 20 first enters the die tip hole 10 of the die tip 7, as shown in FIG. A hole is punched out, and the punched scrap 31 is punched out from this pilot hole.
Also enters the die tip hole 10.

When the die body 5 further descends, the plate material 22 and the ejector member 23 further descend against the first spring 28, as shown in FIG. The hole flange 22bb is formed by pressing out the peripheral portion of the prepared hole of the plate material 22.
In addition, at this time, the die chip 7 is attached to the punch 20.
Since the lowering is prevented by the step between the prepared hole forming part 20a and the hole flange forming part 20b, as the die main body 5 descends, it rises relative to the die main body 5 and the die main body 5, The die spring 12 is compressed.

As the burring process progresses in this manner and the die body 5 reaches a predetermined position slightly before its bottom dead center, as shown in FIG. 29 and begins to compress the second spring 29.

When the die body 5 reaches the bottom dead center, the plate material 2
2, the hole flange portion 22a is completely formed, and the burring process is completed. Then, when the die body 5 is lifted up, the punch assembly 1
The ejector member 23 of No. 3 is first connected to the second spring 29
is pushed up by the strong spring force (of course,
At this time, the first spring 28 also
), the plate material 22 is pushed up by the punch 20
Even if the plate material 22 is bitten by the punch 20, the plate material 22 is separated from the punch 20 and rises. On the other hand, the die tip 7 is moved between the die body 5 and the die tip by the force of the die spring 12.
It descends relative to the guide 2. This returns the punch assembly 13 and die assembly to the initial state shown in FIG. In addition, even if the mold returns to its initial state in this way, the punched scraps 31
will not fall downward from the die tip hole 10.

From then on, each time the plate material 22 is moved horizontally and positioned at a predetermined position, the above-mentioned operation is repeated, holes are punched one after another at the predetermined positions of the plate material 22, and burring is performed. Further, the punched scraps 31 are stored in the punched scrap accommodating portion 11 through the die tip hole 10.

Furthermore, after the second spring 29 has been restored to its original shape, only the first spring 28 pushes up the ejector member 23;
When only the ejector member 8 pushes up the ejector member 23, the plate material 22 has already stopped biting against the punch 20, so there is no shortage of spring force.

Furthermore, in this press mold, when punching a pilot hole, the strong force of the second spring 29 does not act, and only the relatively weak force of the first spring 28 acts, so that an impression is created on the plate material 22. Never.

Further, since urethane rubber is used as the second spring 29, a spring strong enough to eliminate the sticking of the plate material 22 to the punch 20 can be obtained without increasing the size of the spring 29.
Therefore, it is possible to avoid increasing the size of the punch assembly 13.

Furthermore, since the second spring 29 is only pressed against the ejector member 23 when the die body 5 has descended to the vicinity of its bottom dead center, the amount of deformation thereof may be small, so that it does not cause cracks. Not at all.

In addition, in the present invention, as the second spring 29, instead of the urethane rubber in the above embodiment,
Other elastomers with spring properties may also be used.

Effects of the Invention As described above, the press die for drilling and burring according to the present invention has the following features: (a) Even if the die assembly rises after punching and burring a pilot hole into a plate, the punch does not bite the plate. There is no way that it will stick to you and never leave.

(b) There will be no impressions on the plate material.

(c) Since an elastomer such as urethane rubber is used as the second spring, it is possible to avoid increasing the size of the punch assembly.

(d) The amount of deformation of the second spring may be small, so there is no chance of cracking.

This provides an excellent effect.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of a press mold for drilling and burring according to the present invention (the position of the cross section corresponds to the - line in FIG. 3), and FIG. 3 is a sectional view taken along the - line in FIG. 1; FIG. 4 is a bottom view showing the punch assembly in the embodiment; FIG. 5 is a sectional view taken along the - line in FIG. 3; FIGS. 6 and 7 are cross-sectional views showing the press working process according to the embodiment. 1...Die assembly, 5...Die body,
7...Die tip, 7a...Protrusion, 9...Die hole, 10...Die tip hole, 12...Die spring, 13...Punch assembly, 14...Bottom member, 15...Intermediate Member, 16...presser member,
18...Fixing member, 20...Punch, 20a...
Prepared hole forming part, 20b... Hole flange forming part, 22
... Plate material, 23 ... Ejector member, 25 ... Punch protrusion hole, 28 ... First spring, 29 ... Second spring.

Claims (1)

[Scope of Claims] 1. A press mold for drilling and burring, in which a die assembly is disposed above and a punch assembly cooperating with the die assembly is disposed below, wherein the die assembly comprises: A die body that is raised and lowered by a press machine, a die hole provided in the die body, a die chip that can be raised and lowered relative to the die body and whose lower end enters the die hole, and a lower end of the die chip. The punch assembly has a die tip hole provided in the section, and a die spring that biases the die tip downward with respect to the die body, and the punch assembly is held at a certain position with the tip facing upward. a punch fixed to the punch, a prepared hole forming part formed at the tip of the punch and having a diameter corresponding to the diameter of the die tip hole, and a prepared hole forming part formed on the punch below the prepared hole forming part. , a hole flange forming portion having a diameter corresponding to the diameter of the die hole and the thickness of the plate material to be processed, an ejector member that can be raised and lowered, and the ejector member is provided with the A punch protrusion hole that causes the tip end of the punch to protrude upward from the ejector member when pushed down by the die body; a first spring that biases the die; and a spring force exerted by the first spring that begins to be compressed by the ejector member and biases the ejector member upward only when the die is lowered near the bottom dead center. and a second spring made of a strong elastomer.