JPH06246367A - Method for detecting strip failure and punching die to be used for this method - Google Patents

Abstract

PURPOSE:To surely detect the generation of a strip failure even if such a phenomenon is caused as a punch is raised under the state of contact between the punch and a ram to raise a metallic sheet. CONSTITUTION:A punch press is so structured that, when a ram 19 is lowered from the top dead center and positioned at a height lower than a prescribed height position, the lower end of a punch 17 comes into contact with a metallic sheet W, and the ram 19 and the metallic sheet W are electrically connected with each other, and that, when the ram 19 is raised from the bottom dead center and positioned higher than at the prescribed height position, the punch 17 is relatively stripped against the metallic sheet W, and the ram 19 and the metallic sheet W are electrically disconnected. Then, even when the ram 19 with the contact with the punch 17 maintained is raised to be positioned higher than at the prescribed height position, by detecting the continuation of the electrically connected state between the ram 19 and the metallic sheet W, the generation of a strip failure is detected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a strip miss detecting method for detecting whether or not a punch does not strip relative to a metal plate (hereinafter referred to as "strip miss" as appropriate), and this strip miss. The present invention relates to a punch die used for a detection method.

[0002]

2. Description of the Related Art As a prior art of a strip error detection method, there is one disclosed in Japanese Patent Publication No. 57-39850.
This prior art will be briefly described below.

In this prior art, by detecting that the ram separates from the punch and the electrical connection between the ram and the metal plate is cut off in the process of the ram rising from the bottom dead center to a predetermined height position. , Detecting strip mistakes. That is, when the punch strips relative to the metal plate, while the ram rises from the bottom dead center to the predetermined height position, the punch is moved to the ram by the upward biasing force of the lifter spring and the stripper spring. Ascends under contact. On the other hand, when the punch does not strip on the metal plate (when a strip error occurs)
In the above, while the ram rises from the bottom dead center to a predetermined height position, the metal plate prevents the punch from rising, and the ram separates from the punch. Therefore, by detecting that the electrical connection between the ram and the metal plate is interrupted before the ram rises from the bottom dead center to the predetermined height position, the ram is separated from the punch and a strip error occurs. Can be detected.

[0004]

By the way, when a strip error occurs in a relatively thin metal plate, a relatively light metal plate, or the like, while the ram rises from the bottom dead center to a predetermined height position, A phenomenon may occur in which the punch is lifted and lifts the metal plate under the state where the punch and the ram are in contact with each other without the lift of the punch being hindered by the metal plate. When the above phenomenon occurs, there is a problem that the strip miss cannot be detected despite the strip miss.

Therefore, an object of the present invention is to provide a strip mistake detection method capable of appropriately detecting a strip mistake even when the above phenomenon occurs, and a punch die used in this method. And

[0006]

In order to solve the above-mentioned conventional problems, in the present invention, as a first means, a punch and a die are vertically opposed to each other, and the punch is provided above the punch. A ram that raises and lowers the body integrally is provided.When the ram descends from the top dead center and is located at a height position below a predetermined height position, the lower end of the punch contacts the metal plate and the ram and the metal plate are electrically connected. When the ram rises from the bottom dead center and becomes higher than a predetermined height position, the punch strips relative to the metal plate to electrically connect the ram and the metal plate. A punch press configured to cut off the state, wherein the ram and the metal plate are electrically connected to each other even if the ram rises from the bottom dead center and is higher than the predetermined height position while maintaining contact with the punch. Check that the static connection status continues. By detects that the strip miss has occurred.

As a second means, in the punch die used in the strip miss detecting method according to the first means, the punch is installed in a cylindrical punch guide provided in a mounting hole in a punch holding frame so as to be vertically movable. A lifter spring that can be moved up and down and that biases the punch guide upward with respect to the punch holding frame and a stripper spring that can bias the punch upward with respect to the punch guide are provided. In addition, the biasing force of the stripper spring is configured to be larger than the biasing force of the lifter spring, and an insulating plate retainer made of an insulating material is provided at the lower end portion of the punch guide.

[0008]

In the above structure, after the metal plate is positioned between the punch and the die, the ram is lowered from the top dead center to the bottom dead center, whereby the punch is lowered and the metal is supported by the punch and the die. The plate is punched.

When the lower end of the ram contacts the upper end of the punch while the ram descends from the top dead center to the bottom dead center as described above, it resists the urging force of the lifter spring,
The punch and punch guide descend together with the ram. As a result, the insulating plate retainer comes into contact with the metal plate, and the metal plate can be pushed from above.

After the insulating plate retainer comes into contact with the metal plate,
The punch further descends integrally with the ram while resisting the biasing force of the stripper spring. At this time, when the ram is located at a height position equal to or lower than the predetermined height position, the lower end of the punch contacts the metal plate to electrically connect the ram and the metal plate. On the other hand, even if the ram is located at a height below the predetermined height,
If it is not detected that the ram and the metal plate are electrically connected, it can be seen that the lower end of the punch is broken, or the metal plate is not located between the punch and the die.

After the ram is lowered to the bottom dead center as described above, the ram is raised from the bottom dead center to the top dead center.

In the process of raising the ram, the punch rises integrally with the ram due to the biasing force of the stripper spring. Then, when the ram is higher than the predetermined height position, the punch strips relative to the metal plate,
It is detected that the electrical connection between the ram and the metal plate is cut off. Here, the insulating plate retainer presses the metal plate from above by the action of the urging force of the lifter spring, and the punch can easily strip the metal plate. After the punch strips against the metal plate, the urging force of the lifter spring is also combined to raise the punch and the punch guide integrally with the ram. On the other hand, if it is detected that the electrical connection state between the ram and the metal plate continues even if the ram is higher than the predetermined height position, it can be seen that a strip error has occurred.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to this embodiment will be described below with reference to the drawings.

Referring to FIG. 1, the turret punch press 1 is provided with a main body frame 7 composed of an upper frame 3 and a lower frame 5 which are vertically opposed to each other. The upper frame 3 is provided with an upper turret 11 on which a large number of punch dies 9 are detachably attached, and the lower frame 15 is provided with a lower turret 15 on which a large number of dies 13 are detachably attached. It is provided opposite to. Then, the upper turret 11 and the lower turret 15 rotate in the same direction in synchronization with each other by driving a turret servomotor (not shown).

Above the upper turret 11 of the upper frame 3, a ram 19 for pressing a punch 17 forming a part of the punch die 9 is provided so as to be vertically movable. In order to raise and lower the ram 19, the base of the ram 19 is pivotally connected to an eccentric part 23 of a crankshaft 21 rotatably provided on the upper frame 3, and the crankshaft 21 is a flywheel (not shown). , Is connected to a ram motor (not shown) via a clutch brake. A hydraulic cylinder may be used as a structure for moving the ram 19 up and down instead of using the crankshaft 19, the ram motor, or the like.

A work table 25 for supporting the metal plate W is provided on the front side (right side in FIG. 1) of the lower turret 15 in the upper frame 5, and the work table 25 is not shown in detail, but is not shown in the lower part. It is composed of a fixed table integrally provided on the frame 5, and a pair of movable tables provided movably in the front-rear direction on both left and right sides (front and back in FIG. 1) of the fixed table.

The work table 25 is provided with a clamp device 27 for holding the metal plate W. The clamp device 27 moves in the front-rear direction integrally with the movable table of the work table 25, and moves to the left and right of the movable table. It moves in the direction.

The details of the punch die 9 will be described with reference to FIG. 2. The mounting hole 2 in the upper turret 11 is described below.
A cylindrical insulating sleeve 31 made of an insulating material is provided in the insulating member 9, and a wear-resistant guide bush 33 is integrally provided in the insulating sleeve 31. If the insulating sleeve 31 has abrasion resistance, the guide bush 33 does not necessarily have to be provided independently. A cylindrical punch guide 35 is provided on the guide bush 33 so as to be vertically movable, and the punch 17 is vertically movable inside the punch guide 35. A ring-shaped insulating plate holder 37 made of an insulating material is provided at the lower end of the punch guide 35.

The punch guide 35 is provided between the flange portion of the guide bush 33 and the flange portion of the punch guide 35.
Is provided with a lifter spring 39 capable of urging the punch 17 in the upward direction, and a stripper spring 41 capable of urging the punch 17 in the upward direction is provided between the flange portion of the punch guide 35 and the flange portion of the punch 17. Here, the biasing force of the stripper spring 41 is larger than the biasing force of the lifter spring 39.

Referring again to the ram raising / lowering cycle diagrams in FIGS. 1 and 3, the turret punch press 1 of this embodiment is shown.
In the above, when the ram 19 descends from the top dead center P and is located at a height position below a predetermined height position, the lower end of the punch 17 contacts the metal plate W and the ram 19 and the metal plate W are electrically connected. When the ram 19 rises from the bottom dead center Q and becomes higher than a predetermined height position, the punch 1 is configured to be connected.
7 is stripped relative to the metal plate W to form the ram 19
And the metal plate W are electrically disconnected from each other. In other words, the ram 19 and the metal plate W are electrically connected to each other in a region below the predetermined height position in the elevating region of the ram 19, and the predetermined height in the elevating region of the ram 19 is electrically connected. In the region above the position, the electrical connection between the ram 19 and the metal plate W is cut off.

In order to detect whether or not the ram 19 and the metal plate W are electrically connected, one end of an electric circuit 45 having a power source 43 is connected to the lower end of the ram 19, and
The other end of the electric circuit 45 is connected to the clamp device 27. In the middle of the electric circuit 45, for example, Japanese Patent Publication No.
An electrical connection detector 47 such as the relay shown in Japanese Patent No. 39850 is provided. The lower end of the ram 19 is shown in FIG.
As shown in FIG. 5, an insulating member 49 is appropriately provided, and the other end of the electric circuit 45 may be connected to the lower turret 15 or the die 13 instead of being connected to the clamp device 27.

As shown in FIG. 6, arc-shaped first and second dogs 51 having appropriate lengths are provided at appropriate positions of the crankshaft 21.
a and 51b are provided, and a limit switch 53 which is operated by abutting the first and second dogs 51a and 51b is provided at an appropriate position on the upper frame 3. When the limit switch 53 is in the ON state due to the abutment of the first dog 51a, in the elevating region of the ram 19, a position slightly lower than the predetermined height position above the bottom dead center is exceeded. It can be seen that the ram 19 is located in a region up to an appropriate height position (a height position near the bottom dead center). Further, the limit switch 53 is contacted by the contact of the second dog 51b.
Is in the ON state, in the ascending / descending region of the ram 19, the height is slightly above the predetermined height position and slightly above the predetermined height position above the appropriate height position. It can be seen that the ram 19 is located in the area up to the position.

The outline of the present embodiment will be described including the operation based on the above-mentioned configuration.

After the metal plate W is supported on the work table 25, the metal plate W is gripped by the clamp device 27, and the clamp device 27 is moved in the front-rear direction and the left-right direction to move the metal plate W to the upper turret 11. It is placed in a predetermined position between the lower turrets 15. Further, the servo motor for the turret is drive-controlled to rotate the upper turret 11 and the lower turret 15 by a predetermined angle, and the predetermined punch die 9 and die 13 are positioned vertically below the ram 19. Then, the crankshaft 21 is rotationally driven to lower the ram 19 from the top dead center P to the bottom dead center Q, so that the punch 17 in the predetermined punch die 9 and the predetermined die 13 cooperate with each other to form the metal plate W. On the other hand, desired punching is performed.

In the process in which the ram 19 descends from the top dead center P to the bottom dead center Q as described above, when the lower end of the ram 19 first contacts the upper end of the punch 17, the punch 17 and the punch guide 35 cause the lifter spring to move. While resisting the urging force of 39, it descends integrally with the ram 19. by this,
The insulating plate retainer 37 contacts the metal plate W and presses the metal plate W from above.

After the insulating plate retainer 37 comes into contact with the metal plate W, the punch 17 is further lowered integrally with the ram 19 while resisting the biasing force of the stripper spring 39. At this time, when the ram 19 is located at the predetermined height position as shown in FIG. 3, the lower end of the punch 17 contacts the metal plate W, the electrical connection detector 47 is switched to the ON state, and the ram 1
It is detected that 9 and the metal plate W are electrically connected. When the ram 19 further descends and is located at a height position slightly lower than the predetermined height position, the limit switch 53 is switched to the ON state as shown in FIG. 3 by the contact of the first dog 51a. On the other hand, even if the limit switch 53 is switched to the ON state by the contact of the first dog 51a,
It can be seen that when the electrical connection detector 47 is kept in the OFF state, the lower end of the punch 17 is broken, or the metal plate W is not located between the punch 17 and the die 13.

After the ram 19 is lowered to the bottom dead center as described above, the ram 19 is raised from the bottom dead center Q to the top dead center P.

In the process of raising the ram 19, the punch 17 rises integrally with the ram 19 due to the urging force of the stripper spring 41. When the height position of the ram 19 exceeds the appropriate height position (the height position near the bottom dead center), the contact state between the first dog 51a and the limit switch 53 is released and the limit switch 53 is turned off. Switch to. On the other hand, as shown in FIG.
If the electrical connection detector 47 is switched to the OFF state before the switch 3 is switched to the OFF state, this means that the punch 17 causes the metal plate W to move.
This means that only the ram 19 has risen and stopped while still eating the strip, which is detected as a strip miss.

When the ram 19 further rises and the height position of the ram 19 becomes higher than the predetermined height position, the electric connection detector 47 is switched to the OFF state as shown in FIG.
The punch 17 strips relative to the metal plate W, and it is detected that the ram 19 and the metal plate W are electrically disconnected. Here, the insulating plate retainer 31 presses the metal plate W from above by the action of the urging force of the stripper spring 41, so that the punch 17 can easily strip the metal plate W. After the punch 17 has stripped the metal plate W, the lifter spring 39
Punch 17 and punch guide 35
Rises together with the ram 19.

At this time, as shown in FIG. 3, when the ram 19 is located at a height position slightly lower than the predetermined height position, the limit switch 53 is abutted by the second dog 51b.
Is switched to the ON state and the ram 19 is located at a height position slightly above the predetermined height position, the second dog 51b
Then, the contact state of the limit switch 53 is released, and the limit switch 53 is switched to the OFF state. On the other hand, as shown in FIG. 4, even if the contact state with the second dog 51b is released and the limit switch 53 is switched to the OFF state, if the electrical connection detector 47 is kept in the ON state, the punch 17 may be a metal. It can be seen that the punch 17 lifts the metal plate W while still biting the plate W, so that the electrical connection between the ram 19 and the metal plate W is continued and a strip error occurs.

According to the present embodiment as described above, in the case where a strip error occurs and the punch 17 is lifted under the condition that the punch 17 and the ram 19 are in contact with each other, the metal plate W is lifted. Even if there is, it is possible to reliably detect the occurrence of the strip mistake, and it is possible to improve the punching work efficiency.

The present invention is not limited to the above description of the embodiments, but can be implemented in various other modes by making appropriate changes.

[0033]

As can be understood from the above description of the embodiments, according to the present invention, the strip rises and the punch is lifted under the condition where the punch and the ram are in contact with each other, and the metal plate is held. Even if the phenomenon of raising is caused, it is possible to reliably detect the occurrence of the above-mentioned strip mistake, and it is possible to improve the punching work efficiency.

[Brief description of drawings]

FIG. 1 is a schematic view showing a part of a side surface of a turret punch press of this embodiment.

FIG. 2 is an enlarged view of a punch die.

FIG. 3 is an operation explanatory view.

FIG. 4 is an operation explanatory view.

FIG. 5 is an operation explanatory view.

FIG. 6 is a diagram showing a dog and a limit switch used in this embodiment.

[Explanation of symbols]

 1 Turret Punch Press 9 Punch Die 13 Die 17 Punch 19 Ram 45 Electric Circuit 47 Electric Connection Detector

Claims (2)

[Claims] 1. A punch and a die are vertically opposed to each other, and a ram for integrally raising and lowering the punch is provided at a position above the punch, and the ram descends from a top dead center and has a height equal to or lower than a predetermined height position. When the punch is positioned at the upper position, the lower end of the punch comes into contact with the metal plate to electrically connect the ram and the metal plate, and the ram rises from the bottom dead center to be higher than the predetermined height position. In such a punch press, the punch strips relative to the metal plate to interrupt the electrical connection between the ram and the metal plate, and the ram moves downward while maintaining contact with the punch. Even if it rises from the dead point and becomes higher than the predetermined height position, it is possible to detect that a strip mistake has occurred by detecting that the electrical connection state of the ram and the metal plate continues. Strip miss detection method . 2. The punch die used in the strip error detection method according to claim 1, wherein the punch is provided so as to be able to move up and down in a cylindrical punch guide provided in a mounting hole in a punch holding frame so as to be able to move up and down. And a lifter spring capable of urging the punch guide upward with respect to the punch holding frame, and a stripper spring capable of urging the punch upward with respect to the punch guide. The urging force of the spring is configured to be larger than the urging force of the lifter spring, and an insulating plate retainer made of an insulating material is provided at the lower end of the punch guide.