JPH04190931A - Drawing die with locking mechanism - Google Patents

Abstract

PURPOSE:To prevent the generation of the difference for the working timing by composing with the slave cam member which controls the elevation of the cushion of lower die, the master cam member which controls the advancement of above and the cam driver which drives them matching to the elevating and lowering of the upper die. CONSTITUTION:On the press working time, a master cam member 19 is driven with a cam driver 18 matching to the elevation of an upper die 13, and a slave cam member 21 is driven with this master cam member 19. And when this upper die 13 reaches to the bottom dead center the slave cam component 21 being at the advancing position controls the elavation of the cushion 14 of lower die being in max. pressed down state. And when the cushion 14 of lower die is elavated to the height separating from the lower die 12, the master cam member 19 is driven with the cam driver 18, and the slave cam member 21 is moved backward with this master cam member 19, the engagement with the cushion 14 of lower die is released, and the elevation of the cushion 14 of lower die is allowed. On the result, the formings can be removed from the die without deforming with the cushion 14 of lower die.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a drawing die.

In deep drawing forming using a conventional press, the drawing step may be divided into two steps and performed in two steps. The press mold used in this second drawing process requires a cushion for each of the upper and lower molds, and the lower cushion must have a locking mechanism to temporarily restrict the rise of the cushion. .

The reason why this locking mechanism is necessary is that without this mechanism, when the upper mold reaches the bottom dead center and the upper mold rises after molding is completed, the cushion of the lower mold that was pushed down would be affected by the upper mold. This is because the pressure is released and the molded product rises at the same time, pushing up and deforming the molded product whose periphery is held between the cushion of the upper mold and the lower mold.

Therefore, some types of drawing dies, such as the drawing die shown in FIG. 5, are conventionally equipped with a locking mechanism.

The drawing die 1 has a lower die main body 2 and an upper die main body 3, and the lower die main body 2 is provided with a lower die cushion 4 approximately in the center thereof so as to be driven upward by a hydraulic cylinder 5. Further, the upper mold body 3 has an annular upper mold pad 6 on its outer circumferential side.
It is provided so as to be elastically biased downward by a gas cylinder 7 filled with nitrogen gas. In addition, the lower mold body 2
The hydraulic cylinder 5 provided in the mold is connected to a relief valve 9 and the like through a hydraulic hose 8, and is further connected to a hydraulic pump 10 outside the mold.

The drawing die 1 performs press forming with the lower mold cushion 4 raised by supplying pressure oil to the hydraulic cylinder 5H. At this time, the upper mold pad 6 provided on the upper mold main body 3 is elastically biased by the gas cylinder 7 and protrudes downward from the upper mold main body 3. Then, when the upper mold body 3 is lowered, the annular upper mold pad 6 that protrudes downward first sandwiches the outer periphery of the panel material W on the lower mold body 2 between it and the lower mold body 2, and The center part of the material W is held between the lower mold cushion 4 and the material W is lowered while compressing the hydraulic cylinder 5 in this state. The hydraulic cylinder 5 to be compressed is
The hydraulic oil is gradually discharged from the relief valve 9 and the like, and the lower die cushion 4 is gradually lowered to form a deep drawing shape. Then, the upper mold body 3 reaches the bottom dead center and the molding is completed.

When the upper die main body 3 reaches the bottom dead center, the hydraulic oil is discharged from the hydraulic cylinder 5 and the internal pressure decreases, so that the force pushing up the lower die cushion 4 is lost.

In this state, the supply of pressure oil to the hydraulic cylinder 5 is stopped until the upper mold body 3 rises to a predetermined height, and the lower mold cushion 4 is locked.

Therefore, even if the upper mold body 3 rises, the lower mold cushion 4
remains at the pressed down position without rising, and the upper die main body 3 rises by a predetermined amount, that is, the same amount as the maximum stroke amount of the scrap cylinder 7 that pushes the upper die pad 6 downward by one inch, When the upper mold pad 6 separates from the lower mold main body 2, the lower mold cushion 4 is unlocked and pressure oil is supplied to the hydraulic cylinder 5 to raise the lower mold cushion 4 and push up the molded product. ing.

Problem to be Solved by the Invention However, in the conventional drawing die 1 described above, the hydraulic pump 10 that supplies hydraulic pressure to the hydraulic cylinder 5 that drives the lower die cushion 4 up and down and the hydraulic oil in the hydraulic cylinder 5 to be compressed are gradually removed. A pressure regulating means such as a relief valve is required to discharge water to the press machine, and the hydraulic circuit extends both inside the mold and outside the mold, and equipment outside the mold such as the hydraulic pump 10 is installed on the press machine, so it is difficult to connect. In addition, it is difficult to set the operating timing of the hydraulic cylinder 5, and there is also a problem that the operating timing is shifted due to oil leakage.

Furthermore, since equipment such as the relief valve 9, the hydraulic pump 10, and the hydraulic hose 8 is required, there is a problem in that the cost is high.

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a drawing die equipped with a locking mechanism that is unlikely to cause a shift in operating timing.

Means for Solving the Problems As a means for solving the above-mentioned problems, the present invention provides a lower mold cushion that descends while clamping a workpiece together with an upper mold main body, an elastic member that presses the lower mold cushion upwardly, A drawing die equipped with a locking mechanism for temporarily blocking a lowered lower mold cushion from rising, wherein the locking mechanism is provided so as to be movable back and forth in a direction intersecting a vertical movement direction of the lower mold cushion. and a cam driver that presses the parent cam member away from the lower mold cushion after the first elastic member that presses the parent cam member toward the lower mold cushion rises by a predetermined distance from its lower limit position together with the upper mold body. and a child cam member that engages with the lower mold cushion in the forward position to prevent the lower mold cushion from rising, and a child cam member that is arranged between the parent cam member and the child cam member to press the child cam member toward the lower mold cushion. and a second elastic member arranged therein.

A child cam member that engages with the lower mold cushion when the locking mechanism of the diaphragm type moves forward to restrict the raising of the lower mold cushion, and a parent cam member that drives the child cam member forward and backward. This parent cam member is composed of a cam driver that drives in accordance with the lifting and lowering of the upper mold, so during press processing,
A cam driver drives a parent cam member as the upper mold moves up and down, and this parent cam member drives a child cam member. and,
When the upper mold reaches the bottom dead center, the child cam member in the forward position engages with the lower mold cushion in the most depressed state,
The rise of this lower mold cushion is regulated. When the upper mold cushion rises to a height where it separates from the lower mold, the cam driver drives the parent cam member, and this parent cam member retreats the child cam member to release the engagement with the lower mold cushion, and the lower mold Cushion rise is allowed. As a result, the lower mold cushion pushes up and removes the molded product without deforming it.

Embodiment Hereinafter, an embodiment of the present invention will be explained based on FIGS. 1 to 4.

The drawing die 11 with a locking mechanism consists of a lower die main body 12 and an upper die main body 13. A lower die cushion 14 is located approximately in the center of the lower die main body 12 and is constantly elastically pushed upward by a gas cylinder 15 filled with nitrogen gas. It is biased and provided. Further, an annular upper mold pad 16 is provided on the lower surface of the peripheral edge of the upper mold main body 13 and is always elastically biased downward by a gas cylinder 17 filled with nitrogen gas.

The locking mechanism includes a cam driver 18 disposed on the upper mold body 13, and a parent cam member 19 and a child cam member 21 disposed on the lower mold body 12 side. A cam portion 18a is provided perpendicularly outside of the upper mold pad 16 of 13, and at its lower end, the cam portion 18a has two surfaces with opposite inclination directions arranged above and below and protrudes outward with a trapezoidal cross section. 18b. Further, the parent cam member 19 is vertically installed below the cam driver 18 in a horizontally slidable state on the outer horizontal part of the lower die main body 12, and has an upper end with an inclination direction opposite to that of the parent cam member 19. Arrange the two sides above and below,
A cam portion 19a that has a trapezoidal cross section and protrudes inward and has the same height as the cam portion 18a of the cam driver 18;
It is provided with a smooth surface 19b that continues perpendicularly to the lower part of a. Further, the parent cam member 19 is connected to the rising portion 1 of the outer edge of the lower die main body 12.
The reaction force receiver 2a is always elastically biased inward by a gas cylinder 19c containing nitrogen gas attached as a part.

Further, on the parent cam member 19, a child cam member 21 is provided.
It is provided so as to be able to slide in the horizontal direction, and is constantly elastically biased inward by a nitrogen gas-containing gas cylinder 21a attached to the vertical portion of the parent cam member 19 as a reaction force receiver. The tip of the child cam member 21 (
The left end in FIG. 1) has an inclined surface 21b formed on the lower side.

The child cam member 21 is biased by the gas cylinder 21a, and the lower mold cam member 14 is pushed down.
When the parent cam member 19 is pushed outward by the cam driver 18, the lower cushion 1 is engaged with the engagement recess 14a formed on the side surface of the lower cushion 1.
The engagement with 4 is released. Further, the engagement recess 14a of the lower mold cushion 14 is formed with an inclined surface 14b on the lower side at an angle that abuts against the inclined surface 21b of the child cam member 21 that engages with the engagement recess 14a, The force that pushes the lower mold cushion 14 upward is converted into a horizontal force that pushes the child cam member 21 in the backward direction.

Further, the gas cylinder 1 elastically urges the parent cam member 19 and the child cam member 21 horizontally inward, respectively.
The force relationship between the gas cylinder 9a and the gas cylinder 21a at the bottom dead center is set such that the gas cylinder 19a for the parent cam member is stronger than the gas cylinder 21a for the child cam member. Further, the gas cylinder 21a for the child cam member is the gas cylinder 15.
The horizontal force is set to be stronger than the horizontal force applied to the child cam member 21 via the inclined surface 14b of the lower mold cushion 14, which is urged upward by the force.

[Registered Trademark J The reference numeral 22 in the figure is a slide notebook made of a material with a low friction coefficient and excellent wear resistance, such as a Teflon resin plate, which ensures smooth sliding of each sliding contact part. It has become so.

Next, the operation of this embodiment configured as described above will be explained. Figure 1 shows the state at bottom dead center, Figure 2 shows the state just before bottom dead center, Figure 3 shows the state just after bottom dead center, and Figure 4 shows the state when demolding. are shown respectively.

When the upper die body 13 descends from the top dead center and the upper die pad 16 comes into contact with the panel material W placed on the lower die body ]2, the downwardly protruding center of the upper die body ]3 The part also comes into contact with the panel material W on the lower mold tongue 14 7 and is clamped therebetween. In this state, the lower mold cushion 14 can be lowered over the entire stroke.In addition, in the locking mechanism, the parent cam member 19 is connected to the gas cylinder 1.
The child cam member 21 on the parent cam member 19 also moves forward, and is further elastically urged in the forward direction by the gas cylinder 21a (the state shown in FIG. 2).
.

Next, with the center portion of the upper mold main body 13 projecting downwardly holding the panel material W between it and the lower mold shoe/jin 14,
This lower mold cushion 14 is pushed down against the elastic urging force of the gas cylinder 15. Then, when the lower mold cushion 14 descends by the stroke amount L1, the upper mold main body 13 reaches the bottom dead center and deep drawing is completed.

At this bottom dead center, the cam portion 18a of the cam driver 18
The distance L2 between the cam portion 19a of the parent cam member 19 is set to be the same as or slightly larger than the stroke amount L1 of the lower mold cushion 14 and the upper mold pad 16.

Then, when the upper mold body 13 reaches the bottom dead center and the lower mold cushion 14 is pushed down to the lowest position, the engagement recess 14a formed on the side surface of the lower mold cushion 14 engages with the tip of the child cam member 21. will be the same height. Then,
The slave cam member 21, which is biased by the gas cylinder 21a, moves forward in the horizontal direction and engages its tip with the engagement recess 14a. At this time, on the inclined surface 14b of the engagement recess 14a,
Since the inclined surface 21b of the child cam member 21 slides, it engages smoothly and prevents the lower mold cushion 14 from rising (the state shown in FIG. 1).

Therefore, the molding of the panel material W is completed, and the upper mold body 1
3 starts rising from the bottom dead center, the lower mold cushion 14
Only the upper die main body 13 rises in a state where the upper mold body 13 is fixed. At this time, the upper mold pad 16 clamps the peripheral edge of the panel material W between the upper surface of the lower mold main body 12 by the elastic urging force of the gas cylinder 17, but the lower mold cushion 14 is prevented from rising. Therefore, the lower mold tension 14 does not deform the panel material W (see FIG. 3).

Then, when the upper mold body 13 rises by the stroke amount L1 of the upper mold pad 16, the upper mold pad 16, which is elastically biased downward, rises to the point where it separates from the lower mold main body 12,
Further, the cam portion 18a at the lower end of the cam driver 18 provided on the upper die main body 13 is connected to the cam portion 18a at the upper end of the parent cam member 19.
9a to retract the parent cam member 19.

When the parent cam member 19 retreats, the gas cylinder 21a that elastically biases the child cam member 21 inward moves back together with the parent cam member 19, so the child cam member 21 is driven backward, and the gas cylinder The elastic biasing force of 21a decreases. Then, when the biasing force of the gas cylinder 21a decreases below a certain level, the lifting force of the lower die cushion 14, which has been converted into a horizontal direction by the inclined surface 14b, becomes dominant, and this lower die cushion 14 pushes the child cam member 21 in the backward direction. The lower mold cushion 14 is unlocked by rising while moving.

The lower mold cushion 14 is then raised by the elastic biasing force of the gas cylinder 15, pushing up the panel material W and removing it from the mold (see FIG. 4).

As described above, according to the drawing die 11 of this embodiment, the locking mechanism is mechanically operated by converting the downward force of the upper die body 13 into horizontal force using the cam member. This eliminates the need for actuators for locking mechanisms such as hydraulic equipment, resulting in significant cost reductions and has advantages such as ease of maintenance. Further, there are advantages in that it is easy to set the operating timing of the locking mechanism, and the timing is less likely to be out of order.

Effects of the Invention As described above, the present invention includes a locking mechanism for a drawing die that includes a cam driver, a parent cam member, and a child cam member, and mechanically locks the lower die cushion to delay the timing of its rise. Compared to the case where the raising and lowering of the lower die cushion is controlled by hydraulic pressure, it is possible to prevent the timing of the rise of the lower die cushion from being out of order, prevent deformation of the workpiece, and also improve the structure of the locking mechanism. It can be simplified.

[Brief explanation of drawings]

Figures 1 to 4 show one embodiment of the present invention.
The figure is a cross-sectional side view showing the state at bottom dead center, Figure 2 is a cross-sectional side view showing the state just before bottom dead center, Figure 3 is a cross-sectional side view showing the state immediately after bottom dead center, and Figure 4 is FIG. 5 is a cross-sectional side view showing a state during demolding, and FIG. 5 is a cross-sectional side view showing a conventional drawing die. 11... Drawing die, 12... Lower mold body, 13...
Upper mold body, 14...Lower mold cushion, 14a.
...Engagement recess, 14b...Slanted surface, 16...
Upper bat, 18...cam driver, 19...
・Main cam member, 19a... Gas cylinder, 21...
・Sub cam member, 21a...gas cylinder, 21b・
...Slope surface, W...Panel material. Applicant Toyota Motor Corporation Representative Patent Attorney Takeshi Watanabe Figure 5

Claims (1)

[Claims] A lower mold cushion that descends together with the upper mold main body while holding the workpiece; an elastic member that presses the lower mold cushion upward;
A drawing die equipped with a locking mechanism that temporarily prevents the lower cushion from rising, wherein the locking mechanism is a parent cam member provided so as to be movable back and forth in a direction intersecting the vertical movement direction of the lower cushion. and,
The first part presses the parent cam member toward the lower mold cushion.
a cam driver that presses the parent cam member away from the lower mold cushion after the elastic member has risen by a predetermined distance from its lower limit position together with the upper mold body; It is characterized by comprising a child cam member that prevents the child cam from rising, and a second elastic member that is disposed between the parent cam member and the child cam member so as to press the child cam member toward the lower mold section. A drawing die with a locking mechanism.