JPH0340418Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) This invention changes the punchable state and non-punching state depending on the workpiece by changing the length of the punch protruding from the retainer. The present invention relates to a press mold that allows the selection of the following.

(Prior Art) For example, in the case of sheet metals for automobile bodies, even if they are for the same car model, depending on the grade, punching may or may not be required in certain parts. In other words, even if the car model is the same, a high-end car has more parts to be installed than a low-end car, so sheet metal for a high-end car needs to have more punched parts than a sheet metal for a low-end car. arise.

From this point of view, by providing a movable bucking plate movable to the retainer on the proximal end surface of the punch and changing the displacement position of the movable bucking plate, the protrusion length of the punch from the retainer can be increased. There has been proposed a device that can selectively take a punchable position where the protrusion length is shortened and a punchable position where the protrusion length is shortened. That is,
Japanese Utility Model Publication No. 48-39740 discloses a type in which the movable bucking plate is stroked in a direction perpendicular to the axis of the punch; A rotary bucking plate is shown. JP-A-59-101239 discloses a device in which the movable bucking plate is driven by an air cylinder.

In this way, if a movable bucking plate is used to switch the punch between the punching enabled position and the punching disabled position, a return spring is always provided to bias the punch toward the punching disabled position. It will be done.

(Problems to be Solved by the Invention) By the way, when the tip of a punch is damaged due to use, it is necessary to immediately replace it with a new punch, and such replacement work is performed quite frequently.

However, as mentioned above, in the case where the punch can be selectively switched between the punching enabled position and the punching disabled position using the movable bucking plate and the return spring, the work of replacing the punch is required. This creates the problem of being extremely troublesome.

To explain this point in detail, when replacing a punch, first remove the retainer from the mold holder, then pull the punch out of the retainer from its base end, and then insert a new punch into the retainer (from its distal end). punch guide hole), and finally,
The retainer replaced with a new punch is fixed to the mold holder. However, if there is a return spring that biases the punch toward its base end, when fixing the retainer to the mold holder, this fixing work must be done while resisting the large biasing force of the return spring. It will not happen.

(Purpose of the invention) The present invention was made in consideration of the above-mentioned circumstances, and it is possible to easily replace the punch in a device in which the punch can be switched between a punching enabled position and a punching disabled position. The purpose of the present invention is to provide a press mold that allows

(Structure of the invention) In order to achieve the above object, the invention has the following structure. That is, the die is held slidably in the axial direction by a retainer attached to the mold holder, and the punching possible position where the length of the protrusion from the retainer is increased according to the sliding displacement and the protrusion from the retainer. a punch that can take a shortened length and a non-punching position; a storage recess formed in the retainer so as to surround the proximal end of the punch; and a recess on the proximal end surface of the punch. a movable bucking plate that is movably held by the retainer and changes the punching possible position and punching disabled position of the punch by changing its displacement position; A first stopper that is slidably fitted on the outer periphery of the punch and provided on the proximal end side of the punch prevents the punch from coming off from the proximal end side, and also allows the punch to come off from the distal end side. a spring seat washer arranged in the storage recess, one end of which is in contact with the spring seat washer, and a return spring for biasing the punch toward the non-punching position; a second stopper that is fixedly held on the retainer at a position that does not interfere with the punch and that prevents the spring washer from being displaced beyond a predetermined amount toward the proximal end of the punch with respect to the retainer; It is configured as follows.

In the present invention configured as described above, when the punch is pulled out from the retainer to replace the punch, the return spring brings the washer for the spring seat into contact with the second stopper, and this state is retained. Accordingly, when a new punch is installed in the retainer, it is only necessary to insert the new punch into the guide hole of the retainer after passing through the washer for the spring seat. Further, when fixing the retainer to the mold holder, it can be done while the second stopper receives the biasing force of the return spring, so this fixing work can be easily performed.

(Effect of the invention) As described above, in the present invention, the punching possible position and the non-punching position of the punch can be selectively changed by using the movable bucking plate and the return spring. At the same time, the punch can be replaced easily.

(Example) An example of the present invention will be described below based on the attached drawings.

In FIG. 1, 1 is an upper mold holder, 2 is a lower mold holder, and the upper mold holder 1 is a guide post 3.
It is designed to be moved up and down with respect to the lower mold holder 2 using as a guide.

Punches 6, 6', 7 are attached to the upper mold holder 1 via retainers 4, 4' or 5, and corresponding punches 6, 6', 7 are attached to the lower mold holder 2. dies 8, 8', and 9 are provided.
Among these punches 6, 6', and 7, the punches 6, 6' punch out all kinds of workpieces, and the punch 7 does not punch out some kinds of workpieces. .

One embodiment of the mounting structure of the punch 7 will be explained with reference to FIGS.
0, and is positioned on the upper mold holder 1 by a dowel pin (not shown) inserted into the dowel pin insertion hole 5a. It is fixed to the mold holder 1.

The retainer 5 has a punch mounting hole 11 into which the punch 7 is fitted without rattling, and a storage recess 12 formed above the punch mounting hole 11 and connected to the punch mounting hole 11 and having a larger diameter than the punch mounting hole 11. There is. The punch 7 has a large-diameter head 7a, a medium-diameter head 7b, and a small-diameter head 7c, which also function as a first stopper, in order from the side of the fixed bucking plate 10 downward, and the side of the large-diameter head 7a. The end surface is a tapered surface 7d. The length of the large diameter portion 7a in the axial direction is smaller than the length of the storage recess 12, so that the punch 7 can freely slide in the axial direction with respect to the retainer 5, and the return spring described below 13
is urged toward the fixed bucking plate 10 side, that is, toward the upper mold holder 1 side.

A holding hole 14 is formed in the retainer 5 in cooperation with the fixed bucking plate 10 and connected to the upper part of the storage recess 12, and the holding hole 14 extends in a direction perpendicular to the axis of the punch 7. A movable backing plate 15 is slidably inserted here.
The distal end surface of the movable bucking plate 15 is tapered 15a as a cam surface corresponding to the tapered surface 7d of the punch 7, and an intermediate member 17 is fixed to the lower surface of the proximal end with screws 16, so that the entire It is configured in a roughly L-shape.

Further, an air cylinder 19 is fixed to the retainer 5 via a bracket 18. That is,
The bracket 18 is fixed to the retainer 5 by screws 26, and the cylinder 19a of the air cylinder 19 is fixed to the bracket 18 by screws 27. The air cylinder 19 has its axis, that is, the piston rod 19b, extending in a direction perpendicular to the punch 7.
The intermediate member 17 of the movable bucking plate 15 is fixed to the tip of the movable backing plate 15 using a nut 20.

With the above-described configuration, when the moving bucking plate 15 is moved leftward in FIG. 4 by the air cylinder 19, the punch 7 is moved downward against the return spring 13 by the action of both tapered surfaces 7d and 15a. It is pressed and finally advances and is interposed between the large-diameter head 7a of the punch 7 and the fixed backing plate 10 (see FIG. 5). This results in
The punch 7 has a thickness greater than that of the movable backing plate 15 than the state shown in FIG. 4 (corresponding to FIG. 1).
In this state, the workpiece can be punched out by the punch 7. In this state, the punch 7 protrudes from the retainer 5 by the length of the retainer 5 (the length of the protrusion from the retainer 5 is shown in FIG. 5, _l1 ).

Conversely, when the movable bucking plate 15 is moved to the right in FIG. 5 by the air cylinder 19, the movable bucking plate 15 is in the state shown in FIG. 4, and the large diameter head 7a of the punch 7 is fixed. Since the punch 7 is directly seated on the bucking plate 10, the protrusion length of the punch 7 from the retainer 5 is shortened by the amount l described above. This makes it impossible for the punch 7 to punch out the workpiece (the punch 7 does not reach the die 8 (workpiece) even if the upper mold holder 1 is at the end of its downward stroke).

Here, the return spring 13 portion will be described in detail with reference to FIGS. 2 and 3. A spring seat washer 21 is fitted into the middle diameter portion 7b of the punch 7. The spring seat washer 21 has a hole diameter smaller than the large diameter head 7a of the punch 7, so that the spring seat washer 21 has a hole diameter smaller than the large diameter head 7a of the punch 7.
It is locked by the stepped portion 7e of the medium diameter portion 7b, and is prevented from coming off from the large diameter head 7a side. In addition, the retainer 5 has a pair of spring receiving recesses 22 at a radially symmetrical position of the punch mounting hole 11, that is, the punch 7 in a portion corresponding to the bottom surface of the storage recess 12.
is formed. And this spring receiving recess 2
The lower end portions of the return springs 13 each made of a small diameter coil spring are housed in the spring 2, and the upper end portions of the return springs 13 are seated on the spring washer 21. As a result, the punch 7 is urged toward the upper mold holder 1 by the return spring 13 as described above.

Furthermore, two escape spaces 23 are formed in the retainer 5 so as to be continuous with the storage recess 12 and at radially symmetrical positions of the punch attachment hole 11 , that is, the punch 7 . On the bottom of this escape space 23,
As shown in FIG. 2, each screw hole 5c is formed, and a second stopper 24 seated on the bottom surface is fixed to the retainer 5 by a long screw 25 that is screwed into the screw hole 5c. . The pair of second stoppers 24 has a locking arm portion 24a that faces toward the center in the radial direction of the punch 7, and this locking arm portion 24a is located at a position where the punch 7 cannot punch (the third
The washer 21 for the spring seat when it is in Fig. 4)
It is arranged to exist directly above the .

With such a configuration, the return spring 13 made of a coil spring has a small diameter, so that the storage space for the return spring 13 is small, and
Because the diameter is small, the spring force is stronger than a coil spring with a larger diameter for the same wire diameter. Therefore, the biasing force against the punch 7 can be sufficiently increased while minimizing the return spring storage space. Further, the spring receiving recess 22 formed on the retainer 5 side of the return spring 13 can be easily formed by drilling. This means that when a large-diameter coil spring that surrounds the punch 7 is used, the storage recess formed on the retainer 5 side must be formed as an annular one that surrounds the punch 7 (punch attachment hole 11). Taking this into consideration, the advantage of ease of processing can be understood.

Further, by providing the second stopper 24 as described above, when the retainer 5 is removed from the upper mold holder 1 and another punch 7 is replaced, the spring washer 21 and the return spring 13 are each held in the retainer 5. Because it remains as it is,
When attaching a new punch 7 to the retainer 5, insert the new punch 7 into the third position from the tip side.
It is only necessary to insert the spring washer 21 from above in the figure and fit it into the punch attachment hole 11. Moreover,
The subsequent work of fixing the retainer 5 to the mold holder 1 can be performed while all or most of the urging force of the return spring 13 is received by the second stopper 24. In this way, the punch 7 can be easily replaced as a whole.

Next, the configuration of the portion that controls the operation of the air cylinder 19 will be explained with reference to FIG. 6.

By the piston 19c of the air cylinder 19,
Inside the cylinder 19a are two chambers 19d and 19e.
One chamber 19d is connected via piping 28, and the other chamber 19e is connected via piping 29 to two outlet ports of a four-port three-position electromagnetic switching valve 30. There is. One of the two inlet ports of this switching valve 30 is
It is connected to an air tank 32 via piping 31, and the other inlet port is open to the atmosphere.

The switching valve 30 as described above includes two solenoids 30a and 30b, one of which is the solenoid 30a.
When the solenoid 30b is energized (the other solenoid 30b is deenergized), it becomes the first position A and the chamber 19
e is communicated with the air tank 32, while the chamber 19d
is opened to the atmosphere and the piston rod 19b is extended, thereby bringing the punch 7 to the punching position. Conversely, when the other solenoid 30b is energized (one solenoid 30a is demagnetized), the second position is established, and the chamber 19d is communicated with the air tank 32, while the chamber 19e is opened to the atmosphere and the piston rod 19b is in the second position. is retracted, and thereby the punch 7 is placed in the non-punching position. When both solenoids 30a and 30b are demagnetized, the third position C is established as shown in the figure, and both chambers 19d and 19e are sealed, and the piston rod 19b is held in the extended or retracted position. (This extended or contracted position can also be maintained by opening one of the chambers 19d or 19e to the atmosphere.) Note that an air pump 33 is connected to the air tank 32,
When the pressure in the air tank 32 becomes less than a predetermined value, the air pump 33 is automatically operated, so that air at a predetermined pressure or higher is always stored in the air tank 32.

The control circuit 34 selects the mode of energization of the solenoids 30a and 30b. That is, the control circuit 34 is configured to receive a signal from the control switch 35. For example, when the command switch 35a of the control switch 35 is pressed, the control circuit 34 moves the switching valve 30 to the first position. After setting A, punch 7 as 3rd position C.
to switch and hold the state in which punching is possible. Further, when the command switch 35b of the control switch 35 is pressed, the control circuit 34
0 as the second position B, then the third position C
As a result, punching by the punch 7 is disabled. In this way, the air cylinder 19 is remotely controlled, but the above-mentioned switching valve 30 is installed at a position remote from the air cylinder 19. Further, the control switch 35 is installed in a safe position away from the movable parts of the press, such as near the operation panel of the press.

Although the embodiments have been described above, the present invention is not limited thereto, and includes, for example, the following cases.

By eliminating the control switch 35 and managing the flow order of the workpieces by a computer, and controlling the switching valve 30 by the computer, it is possible to automatically punch a predetermined punch or not punch it depending on the workpiece. (In this case, the control circuit may be built into the computer.)

One press mold may have two or more punches that can be switched between a punching enabled position and a punching disabled position.

As the air for the air cylinder 19, air in air piping installed in the factory may be used. In this case, the air tank 32,
There is no need to separately provide the air pump 33.

The air cylinder 19 is not the retainer 5,
The retainer 5 may be fixedly fixed to a mold holder to which it is attached. However, if the air cylinder 19 is fixed to the retainer 5 as in the embodiment, alignment between the air cylinder 19 and the movable bucking plate 15 will be easier, and the mold holder will have a separate bolt hole etc. for mounting the air cylinder 19. Furthermore, after the retainer 5 and the air cylinder 19 have been made into one set in advance, this one set can be attached to the mold holder, which improves the ease of assembly. However, it has advantages such as being preferable. In addition, as in the embodiment, if the air cylinder 19 is located below the retainer 5 mounting surface of the mold holder, interference between the air cylinder 19 and the mold holder can be avoided. In other words, by providing this air cylinder 19, it becomes unnecessary to separately form a relief part for preventing interference with the mold holder.

The movable bucking plate 15 may be integrally molded into a generally L-shaped piece (there is no need to separately provide the intermediate member 17).

Base end surface of punch 7 (top surface of large diameter head 7a)
An intermediate member may be interposed between the movable backing plate 15 and the movable backing plate 15.

A manual switching valve may be used in place of the electromagnetic switching valve 30 shown in FIG.

As the return spring 13, an appropriate spring such as a cylindrical ureta rubber spring or a large diameter coil spring fitted around the outer periphery of the punch 7 can be used.

[Brief explanation of the drawing]

FIG. 1 is an overall schematic side view showing one embodiment of the present invention. FIG. 2 is a plan view showing the retainer together with the air cylinder. FIG. 3 shows a retaining spring portion, and is a sectional view taken along the line taken along the line in FIG. 2. FIG. 4 shows the state when the punch is in a non-punching position, and is a sectional view taken along the line shown in FIG. 2. FIG. 5 is a cross-sectional view of a portion corresponding to FIG. 4, showing the state when the punch is in a punching possible position. FIG. 6 is a diagram showing an example of an air cylinder control system. 1... Upper mold holder, 5... Retainer, 7...
Punch, 7a...Large diameter head (first stopper), 1
1...Punch mounting hole, 12...Storage recess, 13...
... Return spring, 15 ... Moving bucking plate, 21 ... Washer for spring seat, 24 ...
Second stoppa.

Claims (1)

[Claims for Utility Model Registration] A punchable position that is held slidably in the axial direction by a retainer attached to a mold holder, and the length of the projection from the retainer is increased in accordance with the sliding displacement. and a punch that can assume a non-punching position with a shortened protruding length from the retainer; a storage recess formed in the retainer so as to surround the proximal end of the punch; a movable backing plate that is movably held by the retainer on the proximal end surface side of the punch, and is configured to change the punching possible position and the non-punching position of the punch by changing the displacement position; A first stopper is slidably fitted to the outer periphery of the punch in the recess, and a first stopper provided on the proximal end side of the punch prevents the punch from coming off from the proximal end side. a washer for a spring seat that can be removed from the spring seat; and a washer for a spring seat disposed in the storage recess, one end of which is in contact with the washer for a spring seat to bias the punch toward the non-punching position. a return spring fixedly held on the retainer at a position where it does not interfere with the punch, and restricting the spring washer from being displaced beyond a predetermined amount toward the proximal end of the punch with respect to the retainer; A press mold comprising: a second stopper; and a second stopper.