JPH0242357Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a knockout device for a press machine. More specifically, the present invention relates to a knockout device that enables cold forging processing using a general-purpose press machine equipped with only an ordinary pressure cushion device.

[Background technology and its problems]

Until now, cold forging was considered difficult without a special press machine equipped with a mechanical knockout device. In other words, cold forging is difficult with a general-purpose press machine equipped with a normal pressure cushioning device.

In the case of only a normal pressure cushioning device, it is necessary to raise the top surface of the counter punch to the top surface of the die in order to discharge the product, but as shown in FIG. This is because if the upper surface is raised to the upper surface of the die 3 by the knockout pin 4 received by the atmospheric pressure cushioning device, the next slug 1A cannot be accurately set at the center of the die 3, that is, the center of the counter punch 2. be.

In order to compensate for this, as shown in FIG. 8, the upper limit of the counter punch 2 is lowered one level from the upper surface of the die 3, and a taper 6 or a step is formed on the upper surface of the die 3 around the punch hole 5 into which the counter punch 2 is inserted. A method has also been proposed in which a contact portion is formed and the product 1B is ejected by air, while the next slug 1A is set at the center of the die 3 while being guided by the taper 6.

However, in this method, the ejection of the product 1B is limited to air ejection or three-dimensional feeding when automated, so the product shape and feeding device are limited and instability remains.

[Purpose of the invention] The purpose of the invention is to provide a knock-out device for a press machine that can reliably discharge the product even if it is a cold-forged product, and can also accurately set the slag in a predetermined position. It's about doing.

[Means and actions for solving problems]

Therefore, in this invention, the upper limit of the counter punch by the atmospheric pressure cushioning device is lowered one level from the upper surface of the lower die, and when the product is knocked out, the counter punch is raised to the upper surface of the die using air, thereby ensuring the ejection of the product. On the other hand, when inserting the slug, air is discharged and the counter punch is lowered one step, thereby making it possible to accurately set the slug at the center of the lower die.

Specifically, in a press machine equipped with a normal pressure cushion device in the bed, the lower end of a knockout pin provided vertically slidably in the lower die is brought into contact with the normal pressure cushion device. , a killer pin is protrudingly provided, and a push pin is protrusively provided on the upper die having the punch to push down the atmospheric pressure cushion device via the killer pin before the punch comes into contact with the slug set in the lower die; A counter punch is provided coaxially with the knockout pin in the lower mold so as to be slidable in the vertical direction when the knockout pin is at the upper limit position and the upper end surface is lower than the upper surface of the lower mold; It is characterized by providing means for raising the counter punch by air pressure.

〔Example〕

FIG. 1 shows the main parts of the knockout device of this embodiment. In the figure, a normal pressure cushion device 12 made of, for example, bellows is provided in a bed 11 of the press machine, and a lower die set 21 constituting a lower die 20 is installed on the upper surface of the bed 11. It is provided. A killer pin 13 is provided on the upper surface of the normal pressure cushioning device 12 at right angles and projects through the bed 11 and the lower die set 21 and upwardly of the lower die set 21.

Further, a die holder 22 is provided on the upper surface of the lower die set 21. An anvil 23 is housed in the center of the die holder 22, and a die 25 is attached to the upper surface of the die holder 22 via a ring 24. In the center of the anvil 23, a central hole 26 with a slightly concave upper part is formed so as to penetrate to the upper and lower surfaces. Inside the center hole 26 is an upper end head of a knockout pin 27 which is slidably provided in the vertical direction through the lower die set 21 and the bed 11 and whose lower end is in contact with the upper surface of the atmospheric pressure cushioning device 12. is the normal pressure cushion device 1
It is possible to enter according to the displacement of 2.
In addition, an escape hole 28 is formed in the upper surface of the lower die set 21, into which the head of the knockout pin 27 fits when the knockout pin 27 is lowered as the normal pressure cushion 12 is lowered. Thereby, when the knockout pin 27 is lowered and its head fits into the relief hole 28, the upper surface of the head of the knockout pin 27 is at the same height as the upper surface of the lower die set 21.

Further, a punch hole 29 is formed in the center of the die 25 so as to pass through the upper and lower surfaces thereof, and a die cover 30 is attached to the upper surface.
A punch guide hole 31 is formed in the center of the die cover 30. In addition, the punch hole 29 has
An escape hole 32 having an inner diameter slightly larger than the inner diameter of the punch hole 29 is formed at the periphery of the upper end opening thereof, and the upper part of the counter punch 33 whose lower part is slidably fitted into the center hole 26 is slidable. It is inserted freely. Here, when the normal pressure cushion device 12 reaches the upper limit position, the upper surface of the counter punch hole 33 pushed up by the knockout pin 27 is positioned at the bottom of the escape hole 32, and from this position. When the counter punch 33 is raised to the maximum, the top surface of the counter punch 33 is at the same height as the top surface of the die 25.
The length of the counter punch 33 is set in advance. Note that a sealed or semi-closed air chamber 34 partitioned by the lower end of the counter punch 33 is formed in the lower part of the center hole 26 .

Further, a punch 43 is attached at right angles to an upper die set 41 constituting an upper mold 40 attached to a slide (not shown) via a punch attachment holder 42 at a position facing the counter punch 33, and the killer pin A push pin 44 is mounted at a right angle to the position opposite to 13. Here, in the process of the slide descending, the lower end of the punch 43 touches the counter punch 33.
The length of the push pin 44 or the killer pin 13 is set in advance so that the lower end of the push pin 44 contacts the upper end of the killer pin 13 before contacting the slug 45A set at the upper end.

Further, an air chamber 3 formed in the center hole 26
4 is selectively supplied with compressed air from an air source 52 such as a compressor via a three-way electromagnetic switching valve 51. Here, as shown in FIG. 2, when the punch 43 moves a predetermined amount away from the product 45B in the process of the slide rising after the slide reaches the bottom dead center, compressed air is supplied for a certain period of time through the three-way electromagnetic switching valve 51. center hole 26
The air is supplied to an air chamber 34 inside.
As a result, only the counter punch 33 rises upward, and the product 45B rises to the same height as the upper surface of the die 25.

Next, the operation of this embodiment will be explained with reference to FIGS. 2 to 6. Now, after the slug 45A is set on the upper surface of the counter punch 33, when the slide is lowered, the push pin 4
The lower end of 4 contacts the upper end of killer pin 13. At this time, the lower end of the punch 43 is not in contact with the slug 45A.

When the slide is further lowered, push pin 4
4, the normal pressure cushion device 12 is pushed down via the killer pin 13. In this process, when the lower end of the punch 43 comes into contact with the slug 45A, the counter punch 33 supported by the normal pressure cushioning device 12 via the knockout pin 27 can also be displaced downward as the normal pressure cushioning device 12 is pushed down. Because it is in the state, slag 45A
is pushed into the punch hole 29 of the die 25.

Eventually, when the lower end of the counter punch 33 comes into contact with the upper surface of the lower die set 21, the counter punch 33
is in a state where it cannot be lowered any further, but the normal pressure cushion device 12 is further pushed down by the push pin 4 via the killer pin 13. As a result, as shown in FIG.
Since the upper surface is separated from the lower end of the knockout pin 27, no upward biasing force acts on the counter punch 33 at all.

When the slide further descends from this state, the counter punch 33 is in a state where it cannot descend any further, so the slug 45A is cold forged into a predetermined shape by the punch 43, as shown in FIG. In addition, in Fig. 5, CS is the normal pressure cushion 12.
ES is the effective stroke of the knockout pin 27, and KS is the stroke by which the normal pressure cushion device 12 is further pressed down after it is separated from the knockout pin 27.

After this molding, when the slide rises, the upper surface of the normal pressure cushioning device 12 comes into contact with the lower end of the knockout pin 27, and when it rises further from this state, the restoring force of the normal pressure cushioning device 12 causes the counter to pass through the knockout pin 27. The punch 33 is raised to the initial position.

Eventually, when the lower end of the push pin 44 separates from the killer pin 13, compressed air from the air source 52 is supplied to the air chamber 34 in the center hole 26 by switching the three-way electromagnetic switching valve 51, as shown in FIG. . As a result, the counter punch 33 is further raised above the head of the knockout pin 27 to a position where its upper surface is approximately at the same height as the upper surface of the die 25. In this state, since the product 45B is located at the same height as the upper surface of the die 25, the product 45B can be reliably taken out. In FIG. 6, AS is the air stroke in which the counter punch 33 is raised by air, KOS is the knockout pin 27 which is raised by the normal pressure cushion device 12 of the counter punch 33,
This is the knockout stroke of the counter punch 33 due to the compressed air supplied to the air chamber 34.

After taking out the product 45B, the compressed air supplied to the air chamber 34 in the center hole 26 is discharged to the outside by switching the three-way electromagnetic switching valve 51, and the counter punch 33 is lowered to the state shown in FIG. Here, the slug 45A is set at the center of the counter punch 33 using the escape hole 32 as a guide. In this state, the upper surface of the counter punch 3 is attached to the die 25.
Since the slug 45A is lowered by the height of the escape hole 32 from the upper surface of the counter punch 33, the slug 45A can be set correctly at the center of the counter punch 33.

Therefore, according to this embodiment, the upper limit of the counter punch 33 by the atmospheric pressure cushioning device 12 is set to the die 2.
Lower the height of the escape hole 32 from the top surface of 5, product 45
When B is knocked out, the air chamber 34 in the center hole 26
Since the counter punch 33 is raised to the upper surface of the die 25 by supplying compressed air to the upper surface of the die 25, in other words, the product 45B is raised to the upper surface of the die 25, so that the discharge of the product 45B can be ensured.
On the other hand, when inserting the slug 45A, compressed air is discharged from the air chamber 34 of the center hole 26 and the counter punch 3
3 is lowered from the upper surface of the die 25 by the height of the relief hole 32, so that the next slug 45A can be set correctly at the center of the die 25.

This has the advantage that cold forging can be performed even with a general-purpose press machine equipped with a normal pressure cushioning device, since the same operation as a mechanical knockout using a cam drive can be performed.

In addition, since the counter punch 33 is raised and lowered by air, the counter punch 33 can be raised and lowered at any timing, and can be stably held in the raised position.
Therefore, there is an advantage that the product delivery device or product supply device is not limited.

[Effect of idea]

As described above, according to the present invention, it is possible to reliably supply slag and knock out products, so it is possible to provide a knock out device for a press machine that is capable of cold forging, which has been difficult in the past.

[Brief explanation of the drawing]

Figures 1 to 6 show an embodiment of the present invention, in which Figure 1 is a sectional view showing the main parts of the knockout device, Figure 2 is a diagram showing the stroke of the slide and counter punch with respect to the crank angle, FIG. 3 to FIG. 6 are operation explanatory diagrams. FIG. 7 and FIG. 8 are diagrams for explaining the conventional problems, respectively. 11...Bed, 12...Normal pressure cushion device, 20...Lower die, 25...Die, 27...Knockout pin, 29...Punch hole, 33...Counter punch, 34...Air chamber, 40 ...upper mold, 4
3...Punch, 44...Pushpin, 45A...
...Slag, 45B...Product, 51...Three-way electromagnetic switching valve, 52...Air source.

Claims (1)

[Scope of utility model registration request] In a press machine equipped with a normal pressure cushion device in the bed, the lower end of a knockout pin provided vertically slidably in the lower die is brought into contact with the normal pressure cushion device, and the lower end of the knockout pin is brought into contact with the normal pressure cushion device. A killer pin is protruded from the upper die having the punch, and a push pin is protruded from the upper die having the punch to push down the atmospheric pressure cushioning device via the killer pin before the punch comes into contact with the slug set in the lower die. A counter punch is provided in the lower mold so as to be slidable in the vertical direction, and the upper end surface reaches the bottom of the relief part lower than the upper surface of the lower mold at the upper limit position of the knockout pin, and further below the counter punch is the knockout pin. A knockout device for a press machine, characterized in that an air chamber is provided in which the counter punch is raised at the upper limit position by compressed air supplied through a switching valve.