JPH0231611B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a mis-punch prevention device that prevents punching from being performed when a punching material is fed into a punching machine at an inappropriate position. It is.

[Prior Art] If punching is performed in a state where the punching material is not fed into the punching machine at the correct position, not only will the material be wasted, but there is also a risk that the die will be galled or damaged.

In order to prevent such mis-punching, the die of the punching machine is equipped with a pilot pin that works together with the punch. Before punching, the pilot pin hits the material surface and is pushed up, and this movement is detected by a limit switch or the like to stop the punching operation.

However, as the punching machine becomes faster, the stroke of the punch becomes shorter, and even if a stop command is issued through the above-mentioned detection, the inertia of the ram prevents it from stopping quickly, which may result in a miss-punch. As shown in Japanese Patent Publication No. 54-48674, the die is equipped with a means to detect a feed error in the punching material, and the detection signal operates a solenoid to project a pin between the upper and lower dies, thereby removing the upper die. The penetrated knockout pin hits the protruding pin and is pushed up during punching, and this action shortens the expandable and retractable shank, thereby reducing the punching stroke.

It should be noted that it is possible to pull the punch of the press mold into the punch holder as needed so that the punch is not processed, as described in JP-A-53
- Shown in Publication No. 16351.

[Problems to be Solved by the Invention] However, shortening the shank using a detection signal for misfeeding as described above is difficult because the detection device and stroke adjustment device are configured separately from the mold. Not only does the structure of the punch become complicated, but it also has drawbacks such as the possibility that the punch may punch out if the punch holder descends due to inertia at high speed.

In addition, in the case where the punch is adjusted to be pulled into the punch holder before the punching operation, there is no mechanism to pull the punch in response to incorrect feeding of the punching material, so it is not possible to prevent incorrect punching during processing. Nakatsuta.

[Means for Solving the Problems] In view of these points, the present invention provides a pilot pin supported by a punch holder so as to be movable up and down, a punch supported by a punch holder so as to be slidable in the punching direction, Equipped with a slider that slides inside the horizontal hole of the punch holder, and an engaging convex part and an engaging concave part are provided on the sliding surfaces of the punch and slider, respectively, and when the pilot pin rises, incorrect feeding is detected and the slider is moved. The punch is pulled into the punch holder by fitting the engagement protrusion of the punch into the engagement recess of the slider.

[Function] Therefore, in proper operation, the engaging convex portion of the punch engages with the convex portion of the slider to cause the punch to protrude from the punch holder, but if the punched material is incorrectly fed, the tip of the pilot pin detects an incorrect feed when the punch hits the punching material surface, and quickly slides the slider before the punch descends to the punching material surface.
The engagement protrusion of the punch is fitted into the engagement recess of the slider to automatically draw the punch into the punch holder. Therefore, even if the upper die is lowered, punching is not performed with the punch, and no punching errors occur.

[Example] An example illustrating this will be described.

In the figure, 1 is a punch holder attached to a ram, 2 is a punch that is inserted and held in the punch holder 1 so that it can move up and down, and is punched by a holding spring 5 via a flange 4 at the tip by a punch holding rod 3 attached to the top surface. It is pushed up into the holder. Reference numeral 6 indicates an engaging convex portion provided on the upper surface of the punch, and 7 indicates a rectangular horizontal hole extending from the side surface of the punch holder 1 to the upper portion of the punch. A slider 8 is inserted into this horizontal hole so as to be in contact with the upper surface of the punch 2. There is. Reference numeral 9 denotes a cover of the horizontal hole, and reference numeral 10 denotes an engagement recess formed on the sliding surface of the slider 8 against the upper surface of the punch, which is adapted to fit into the engagement protrusion 6 of the punch by sliding of the slider.

Reference numeral 11 denotes an elongated hole provided in the slider, which is elongated in the sliding direction to allow the punch holding rod 3 to be inserted therethrough, with a margin greater than the engagement length a between the punch and the slider in the sliding direction. Reference numeral 12 indicates a pilot pin insertion hole provided in the slider, and reference numeral 13 indicates a bolt fixed to the slider 8, which passes through the cover 9 and inserts a spring 15 between the head 14 and the cover 9. It is biased to slide in the direction (rightward in the figure). A pilot pin 16 is vertically movably supported by a spring 17 on the punch holder 1, and is provided with a large diameter portion 18 having a radius difference greater than the engagement length a between the punch and the slider. It is fitted into the pilot pin insertion hole 12, and the depth of this fitting is smaller than the dimension b in which the tip of the pilot pin protrudes from the tip surface of the punch. 19 is a die, 20 is a punching material, 2
1 is a pilot hole in the punched material.

When punching, the slider 8 presses the spring 15 and is pushed into the horizontal hole 7 as shown in the figure.
The large diameter portion 18 of the pilot pin 16 is fitted into the pilot pin insertion hole 12 of the slider 8 by a spring 17 to lock the sliding movement of the slider 8, and in this state, the engagement convex portion 6 of the punch 2 is inserted into the slider 8. The punch 2 is held in contact with the surface of the punch 8 which is disengaged from the engagement recess 10, and the punch 2 is projected from the punch holder 1 by an amount necessary for punching.

Therefore, the ram operates and the punch holder 1
When the punching material 20 is moved downward, if the feed position of the punching material 20 is appropriate, the pilot pin 16 is inserted through the pilot hole 21 of the punching material 20 and inserted into the die 19, and the punch 2 moves the slider 8 from the punch holder 1. It descends in a protruding state through the hole and performs the necessary punching.

However, if the punched material 20 is sent to an incorrect position and the pilot hole 21 is misaligned, the pilot pin 16 will hit the surface of the punched material, and the lowering of the punch holder 1 will press the spring 17 and cause the punch to fall into the mold. be pushed up. Therefore, the large diameter portion 18 comes out of the pilot pin insertion hole 12 and disengages from the slider 8, and the spring 1 is inserted through the bolt 13.
5 to slide the slider 8 in the horizontal hole 7 in the right direction. When it slides by the engagement length a with the punch,
Since the engagement recess 10 faces the engagement protrusion 6 of the punch 2, the punch 2 causes the engagement protrusion 6 to fit into the engagement recess 10 by the spring 5 of the punch holding rod 3, and the punch 6 Pull it into holder 1. Therefore, if this lifting amount is made larger than the cutting amount c of the punch 2 into the die 19, even if the ram does not stop and the punch holder 2 descends to the punching position, the punch 2 will continue punching. Since the material 20 is not reached, no punching is performed.

If the feed position of the punched material 20 is to be corrected and the next punch is to be performed, the punch 2 may be pulled down and the slider 8 pushed in to engage the large diameter portion 18 with the pilot pin insertion hole 12.

In addition, as shown in FIG.
If the engagement side surface of the slider 8 with the engagement recess 10 is made into an inclined surface 22 in the sliding direction, the slider 8
There is no need to pull down the punch 2 when returning the slider, and the punch can be pushed down along the inclined surface and the slider can be returned by simply pushing in the head 14 of the bolt 13.

Further, in the above embodiment, the pilot pin 16
The engagement with the slider 8 is released due to the rise of the
Although the slider 8 is slid by a spring 15, it is also possible to detect the rise of the pilot pin by a limit switch and move the slider by an electromagnetic device.

[Effects of the Invention] As described above, the present invention has a pilot pin which is supported by a punch holder in a vertically movable manner and whose tip rises when it hits the surface of the punched material at an incorrect position, and a pilot pin which is disposed within the punch holder in the punching direction. A punch held so as to be slidable, and a slider that slides in a horizontal hole of a punch holder and comes into contact with the upper surface of the punch, and the sliding surfaces of the punch and the slider are respectively engaged with engaging protrusions. Since a recess is provided, the slider is moved as the pilot pin rises, and the engaging protrusion is fitted into the engaging recess to draw the punch into the punch holder, the overall structure is simplified. In addition to being compact, the punch retraction action is quick and the punch is automatically retracted into the punch holder, making it possible to stop rams and punch holders with large inertia.
There is no need to adjust the amount of descent, and even when the punch holder descends to the punching position, the punch does not come into contact with the punched material, which reliably prevents mis-punch and eliminates wasted material and damage to the mold. be.

In addition, by providing a large diameter part on the pilot pin and engaging it with the slider, when the pilot pin detects an incorrect position, it is lifted and directly disengaged from the slider, making it possible to operate quickly and reliably. Providing inclined surfaces on the engagement protrusion and the engagement recess of the punch and the slider has the effect that the slider can be returned easily and smoothly.

[Brief explanation of drawings]

FIG. 1 is a side sectional view showing an embodiment of the present invention, and FIG.
The figure is a sectional view showing a part of another embodiment. 1 is a punch holder, 2 is a punch, 3 is a punch holding rod, 6 is an engagement convex portion, 8 is a slider, 10 is an engagement recess, 16 is a pilot pin, 18 is a large diameter portion, 19 is a die, 20 is a punch The punched material, 21, is a pilot hole.

Claims (1)

[Scope of Claims] 1. A pilot pin that is vertically movably supported by a punch holder and whose tip rises when it hits a punched material in an incorrect position, and a pilot pin that is held in the punch holder so as to be able to slide in the punching direction. the punch, and a slider that slides in the horizontal hole of the punch holder and comes into contact with the upper surface of the punch, and an engagement protrusion and an engagement recess are provided on the sliding surfaces of the punch and the slider, respectively, and the pilot A mis-punch prevention device for a punching machine, characterized in that a slider is moved in accordance with the rise of a pin, the engaging convex portion is fitted into an engaging concave portion, and the punch is drawn into a punch holder. 2. Claim 1, wherein the pilot pin has a large diameter portion that engages with the pilot pin insertion hole of the slider, and when the pilot pin rises, the engagement with the slider is released and the slider can move. A mis-punch prevention device for a punching machine as described in Section 1. 3. The mis-punch prevention device for a punching machine according to claim 1, wherein the engaging side surface between the engaging convex portion of the punch and the engaging concave portion of the slider is an inclined surface inclined in the sliding direction of the slider.