JPH0744337Y2 - Opposing hydraulic forming device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to an opposed hydraulic forming apparatus, and more particularly to an opposed hydraulic forming apparatus suitable for draw forming of stepped containers.

[Conventional technology and its technical problem]

As a method of processing a container-shaped product from a flat plate, the pressure dome is filled with a liquid such as oil, and a punch having a profile of the product shape is pushed into the pressure dome to directly create an opposing hydraulic pressure. A method of winding a blank around a punch and drawing the same is conventionally known.

In such a counter-hydraulic molding, good drawing can be performed when the product has a simple straight tube shape, but, for example, a stepped container represented by an oil pan of an automobile, that is, a fourth container.
As shown in the figure, a product having a shallow container part c with a large step difference b from the tip container part a could not be drawn with good shape and dimensional accuracy. Conventionally, for such a product, a method has been adopted in which the front end container portion a is once formed by counter-hydraulic molding or conventional die drawing, and the shallow container portion c is formed in the next step. For this reason, the pressing process has to be performed in two steps, and the mold is required for two steps, which causes a problem of high productivity and high manufacturing cost.

Regarding the opposed hydraulic forming apparatus, there is JP-B-59-22887, which is proposed by the applicant. In this prior art, the slider is slidably attached to the lower surface of the blank holder, and the slider is advanced at the initial stage of molding to contact the tapered surface of the punch to prevent the blank from overhanging or bulging. While counter-hydraulic forming of shaped products is convenient, it is clear that drawing of stepped products as described above cannot be done in one stroke.

The present invention was devised to solve the above-mentioned problems, and its purpose is to provide a shallow container part at a large step with a tip container part represented by an oil pan of an automobile. It is an object of the present invention to provide a device having a simple structure capable of accurately performing counter-hydraulic pressure molding in one stroke with a single mold for a product having one of sides or diagonal lines.

[Means for Solving the Problems]

To achieve the above object, the present invention provides a punch tip in an apparatus including a pressure dome having a punch, a hydraulic chamber into which the punch is pushed, and a blank holder for holding a blank between the upper surface of the pressure dome. While providing the profile part and the step profile part following this, at least one groove hole whose tip communicates with the hydraulic chamber is formed in the pressure dome of the part corresponding to the step profile part. A movable die having a die portion and a side wall portion for the hydraulic chamber subsequent to the die portion is arranged so as to be movable in the horizontal direction. Behind the movable die, as a first step, the hydraulic chamber is located at the tip profile portion of the punch. A movable die for advancing the movable die so as to have a conforming shape, and as a second step, for retracting the movable die so that the hydraulic chamber extends to the step profile portion of the punch. It is obtained by a configuration in which the forward and backward means.

The present invention includes the case where the slot, the movable die, and the movable die advancing / retracting means are provided in two or more directions.

Also, the step profile portion of the punch may be immovable,
It may be movable in the vertical direction. As a result, wrinkle pressing force is applied to the blank portion on the upper surface of the movable die at the initial stage of molding, so that the occurrence of wrinkles is effectively prevented.

〔Example〕

 An embodiment of the present invention will be described below with reference to the accompanying drawings.

FIGS. 1 to 3 show an embodiment of an opposed hydraulic forming apparatus for obtaining the stepped container-shaped product shown in FIG.

Reference numeral 1 is a pressure dome, and 2 is a hydraulic chamber filled with the liquid F.
A normal pressure dome has a cylindrical hole with a bottom or a bottom as a hydraulic chamber, and therefore the volume and shape of the hydraulic chamber are fixed. However, in the present invention, the volume and shape of the hydraulic chamber 2 are fixed. Can be changed according to the punch profile.

More specifically, first, as shown in FIGS. 2 and 3, the pressure dome 1 has a linear slot 3 extending toward one side. This slot 3 opens at least on the upper surface of the pressure dome. Since the pressure dome is bottomless in this example,
The lower surface side of the slot 3 is also opened and is closed by the bottom plate 1a together with the pressure dome. The deep end of the slot 3 stops at the thick portion of the pressure / pressure dome 1, thereby forming a side wall portion 30 forming a part of the surrounding wall of the hydraulic chamber 2.

A movable die 4 is slidably fitted in the slot 3. As shown in FIG. 1, the movable die 4 has a side wall portion 40 that rises in a relationship facing the side wall portion 30 at the rear end of the slot and a plate-shaped die portion 41 that extends backward from the upper end of the side wall portion 40. A seal member 42, which is in sliding contact with the bottom plate 1a, is attached to the lower portion of the side wall portion 40.

Reference numeral 5 is a means for moving the movable die 4 forward and backward. In this embodiment, a hydraulic cylinder is used and the slot 3
It is firmly installed inside. The hydraulic cylinder 5 has a rectangular outer shape that matches the slot 3, and also serves as a sliding guide for the die portion 41. A rear end of the hydraulic cylinder 5 is sealed by a plug 50, while a piston 51 is arranged inside, and a tip of a rod thereof is connected to a back surface of a side wall portion 40 of the movable die 4. And the piston chamber 52
Is connected to a movable die control circuit 53 having a hydraulic pump 530, a three-position switching valve 531 and a relief valve 532 as shown in FIG. 1, whereby the movable die 4 is retracted, and a drawing force is exerted at the time of forming the tip shape. The holding force is set so that the movable die 4 does not retract due to the opposing hydraulic pressure.

Reference numeral 6 denotes a punch, which is provided with a tip profile portion 6a having a required length and a step profile portion 6b following the tip profile portion 6a. The rear portion of the punch is fixed to the inner slide 60 via brackets so as to move up and down with a predetermined stroke length. It has become. Naturally, the groove 3 has a groove width equal to or larger than that of the step profile portion 6b.

7 is a blank holder that surrounds the outer periphery of the punch 6,
It is fixed to the outer slide 70 via brackets and moves up and down independently of the inner slide, and a blank W is formed between the die face, that is, the upper surface of the pressure / pressure dome including the upper surface of the die portion 41 of the movable die 4 in this embodiment. It is designed to go in. It goes without saying that the die face includes the case where a face plate having a required thickness is attached to the upper surface of the pressure dome and the upper surface of the die portion of the movable die.

5 and 6 show another embodiment of the present invention. This embodiment is for forming a shallow container part c having the same width W as that of the deep tip container part a as shown in FIGS. The pressure dome 1 is formed with slots 3 open at both left and right ends.
The movable dies 4a and 4b are slidably fitted in the inside of the inside, and means (hydraulic cylinders in this example) 5a and 5b for moving the movable dies 4a and 4b back and forth are installed in the back. .

Movable dies 4a and 4b, as in the previous embodiment, the side wall portion 40
And a die part 41, and the pair of side wall parts 40 and the slot 3
The fluid pressure chamber 2 having a variable volume is formed by the width-direction opposite walls 31, 31. In this case, the punch 6 is provided with a tip profile portion 6a at the center and two step profile portions 6b, 6b behind the punch 6 as shown by the phantom line in FIG. The other parts are the same as those in the previous embodiment, and therefore, the same reference numerals are given.

8 and 9 show another embodiment of the present invention. In this embodiment, as shown in FIGS. 10 (a) and 10 (b), a product shape having a deep container part a at the center and two shallow container parts c and c'extending in the X and Y directions is obtained. It is for.

In this embodiment, the pressure dome 1 is provided with slots 3 in the X direction.
And the slot 3'in the Y direction are formed in an intersecting shape, and a pair of movable dies 4a, 4b, 4c, 4d are slidably fitted into the respective slots 3, 3 ', and these movable dies 4a, 4b are slidably fitted. , 4c, 4d are moved by hydraulic cylinders 5a, 5b, 5c, 5d as means for advancing and retreating, so that a hydraulic chamber 2 having a variable volume is formed. Although not shown, the punch has the same contour as the product shape.

In the above embodiment, the stepped profile portion 6b of the punch 6 is used.
Is immovable, but it may be movable in the vertical direction.
Figures 11 and 11a and 12 show an embodiment thereof. FIGS. 11 and 11a are for obtaining the product shape of FIG. 4, in which the cylinder 10 is built in the portion corresponding to the step profile portion of the punch 6, and the piston rod 100 is formed as a separate block shape. The step profile member 6b 'is connected.

Further, FIG. 12 is for obtaining the product shape shown in FIG. 7, and cylinders 10a, 10b are built in the portions corresponding to the left and right step profile portions of the punch 6, and those cylinders 10a, 1
0b piston rods 100a, 100b are connected to separate profile members 6b ', 6b'.

In the case of a product shape in which the shallow container part is in the corner part of the tip container part, the slot is formed in the diagonal direction of the pressure dome,
A movable die having two side wall portions may be used, and this is also included in the present invention. Of course, the present invention is not limited to forming a stepped container having a rectangular cross section or the like.

As another structure for moving the movable die, if necessary, a straight groove or a dovetail groove for guiding is formed on both upper sides of the groove hole 3, and correspondingly, ridges are formed on both sides of the die portion of the movable die 4. You may provide a part and a part. In addition, the movable die 4
The means 5 for moving back and forth is not limited to a hydraulic cylinder, and a motor driven screw shaft mechanism or the like may be used.

[Operation of Example]

 Next, the usage and operation of the device of the present invention will be described.

In molding the stepped container shown in FIG. 4, the three-position switching valve 531 of the movable die control circuit 53 is operated to send the hydraulic pressure to the piston side. As a result, the piston rod is moved, so that the movable die 4 slides in the groove 3 while being guided by the widthwise wall of the groove 3 and the hydraulic cylinder casing, and reaches the forward end as shown in FIG. As a result, as shown in FIG. 2, the pressure dome 1 forms the hydraulic chamber 2 having a shape and volume corresponding to the tip profile portion 6a of the punch.

In this state, the hydraulic chamber 2 is filled with the liquid F, the blank W is placed on the upper surface of the pressure dome, the blank holder 7 is lowered to sandwich the blank W between the blank W and the dome upper surface, and the punch 6 is lowered. In this way, the tip end profile portion 6a of the punch 6 is in contact with the blank W, and the hydraulic chamber 2 formed as described above is continued.
And the counter hydraulic pressure is generated in the hydraulic chamber 2 (in the case of the forced pressure increasing method, the pre-pressurized hydraulic pressure is increased), and the counter hydraulic pressure causes the blank to be brought into close contact with the tip profile portion 6a. As shown in FIG. 1, the front end container portion a is formed by drawing. In this stroke, the hydraulic cylinder 530 and the three-position switching valve 531 apply a component force of the force drawn into the blank W and a pressure exceeding the opposing hydraulic pressure to the hydraulic cylinder 5, so that the movable die 4 retracts. There is no.

After forming the tip shape in this way, the inner slide temporarily stops the downward movement, and the punch 6 is held at the stroke position. In this state, the three-position switching valve 531 is next switched, whereby the movable die 4 retracts along the slot 3. As a result, as shown in FIG. 3, the hydraulic chamber 2 expands and changes into a shape and volume corresponding to the stepped profile portion 6b of the punch 6. At the same time, hydraulic pressure is supplied to the hydraulic chamber 2.

Then, if the descending stroke of the punch 6 is started again,
Since the step portion profile portion 6b is pushed into the enlarged hydraulic chamber 2 and the counter hydraulic pressure acts on the tip end profile portion 6a and the step portion profile portion 6b, the step b and the shallow container portion c are generated in this process (Fig. 1a). And are drawn.

After that, the blank holder 7 is raised, the punch 6 is raised, the liquid is discharged from the enlarged hydraulic chamber 2 to the outside, and the hydraulic cylinder 5 is operated again to the forward side, whereby the next molding cycle can be started.

In the embodiment shown in FIGS. 5 and 6, if the pair of movable dies 4a and 4b facing each other are moved to the forward ends and lowered by the punch in this state, the front end container portion a is subjected to the counter hydraulic drawing. Then, the lowering of the punch is temporarily stopped and the pair of movable dies 4
When a and 4b are retreated at the same time, liquid is replenished and the punch is lowered again, the movable chambers 4a and 4b retreat and the hydraulic chamber 2 has a shape and volume corresponding to the step profile.
The steps and the shallow container parts c, c on the left and right are effectively formed, and the product shape shown in FIG. 7 is obtained in one stroke. In this embodiment, if the punch shown in FIG. 1 is used and only one side of the pair of movable dies 4a and 4b is moved forward and backward as described above, the product shape shown in FIG. 4 can be formed. You can

In the embodiment of FIGS. 8 and 9, if the pair of movable dies 4a, 4b, 4c, 4d in the X direction or the Y direction are simultaneously held at the forward end and the punch is lowered, the tip container part a will be formed. After being formed, the punch is temporarily stopped, and all movable dies 4a, 4b,
If 4c and 4d are retracted and the punch is lowered, four shallow container parts c,
c ′ is molded, and the product shape as shown in FIG. 10 is obtained.
In this embodiment, if a punch is selected and only one movable die corresponding to the punch is moved forward and backward, the product shape shown in FIG. 4 is obtained, and only a pair of movable dies are moved forward and backward at the same time. Then, the product shapes shown in FIG. 7 can be obtained. Needless to say, in any of the embodiments, a cylindrical or cup-shaped product can be drawn by drawing a normal punch while holding the movable die at the forward end.

In the embodiment shown in FIG. 11, the movable die 4 is located at the forward end, the hydraulic chamber 2 is filled with the liquid, the blank W is sandwiched by the blank holders 7, and the cylinder 10 is operated to operate the step profile member 6b '. And punch 6 in this state.
Is carried out, and molding is performed by the tip profile portion 6a of the punch 6. By doing so, the blank portion located on the upper surface of the movable die 4 between the inner edge of the blank holder 7 and the tip profile portion 6a of the punch 6 is stepped. Since the partial profile member 6b 'is pressed and the piston rod 100 is retracted along with the punch stroke, the front end container part a is formed in a state where the blank is pressed against the entire surface.

Then, as the movable die 4 retreats, the hydraulic chamber 2 expands,
When molding a shallow container portion, the step profile member 6b 'can be integrated with the punch 6 to perform its original function as shown in FIG. 11a.

[Effect of device]

According to the present invention described above, in an apparatus including a punch 6, a pressure dome 1 having a hydraulic chamber into which the punch 6 is pushed, and a blank holder 7 for pushing a blank W between the upper surface of the pressure dome 1. While the punch 6 is provided with a tip profile portion 6a and a step profile portion 6b following the tip profile portion 6b, the pressure dome 1 at a portion corresponding to the step profile portion 6b has at least a groove hole 3 through which the tip communicates with the hydraulic chamber 2. One movable die 4 having a die portion 41 at the upper portion and a side wall portion 40 for the hydraulic chamber subsequent to the die portion 41 is formed in the groove 3 so as to be horizontally movable, and the movable die 4 is provided at the back of the movable die 4. Is the first
As a step, the hydraulic chamber 2 is moved to the tip profile portion 6a of the punch 6.
Move the movable die 4 forward so that the shape matches
In the second stage, the hydraulic chamber 2 is a step profile part of the punch.
Since the movable die advancing / retracting means 5 for retracting the movable die 4 is provided so as to have a shape that extends to 6b, the pressure dome 1 corresponds to the punch tip profile portion 6a according to the operation of the movable die advancing / retracting means 5. A fluid pressure chamber 2 having a shape and a volume and a fluid pressure chamber 2 having a shape and a volume corresponding to the step profile portion 6b are freely formed, and the punch 6 is given a stroke of the first stage and the second stage to thereby form a tip container. A shallow container part c having a part a and a step b can be easily formed in one stroke, and even when a plurality of groove holes, movable dies, and movable die advancing / retreating means are provided, they can be individually moved. Since it can be moved by changing, the product having one shallow container part above the tip container part a, the product having a plurality of shallow container parts, and the product in which each shallow container part has a different size is rich in variety. Own product It can be molded into. Even if four shallow containers are to be obtained, the structure is simple because it requires only four movable dies and four movable dies moving forward and backward means. The excellent effect of being able to do is obtained.

According to claim 4 of the utility model registration, the step profile part is connected to the piston of the cylinder 10 built in the punch 6 and cooperates with the die part 41 of the movable die 4 to serve as a blank holder. Since it is composed of the section profile member 6b ', the step section profile member 6b' directly sandwiches the blank W with the movable die 4 and presses them with rigid bodies when the tip container section a is formed by the tip profile section 6a. Since the blank is subjected to the wrinkle pressing force, the front end container portion a is formed in a state where the blank is pressed against the entire surface, and an excellent effect that a good stepped container without flange wrinkles can be formed is obtained.

[Brief description of drawings]

1 and 1a are cross-sectional views showing an embodiment of an opposed hydraulic forming apparatus according to the present invention at each forming step, and FIG. 2 is a partially cutaway plan view showing a pressure dome at the step shown in FIG. 3 is a plan view of the pressure dome at the stage of FIG. 1a, FIG. 4 (a) is a sectional view of the product shape, and FIG. 4 (b) is the same plan view.
FIG. 5 shows a first embodiment of the pressure dome according to the present invention.
The partially cutaway plan view shown in the staged state, and FIG.
FIG. 7 (a) is a sectional view of the product shape, FIG. 7 (b) is a plan view of the same, FIG.
The drawing is a plan view showing another embodiment of the pressure dome in the present invention in the first stage state, FIG. 9 is a plan view showing the same in the second stage state, and FIG. 10 (a) is a sectional view of the product shape. FIG. 10 (b) is a plan view of the same, FIG. 11 and FIG. 11a are sectional views showing another embodiment of the present invention at each molding step, and FIG. 12 is another embodiment of the present invention. It is sectional drawing shown in the shaping | molding step which differs for every part. 1 ... Pressure dome, 2 ... Hydraulic chamber, 3 ... Groove hole, 4, 4a, 4b, 4c, 4
d ... Movable die, 5, 5a, 5b, 5c, 5d ... Hydraulic cylinder, 6 ... Punch, 6a ... Tip profile part, 6b ... Step profile part, 6b '... Step profile member, 7 ... Blank holder, 10 ... Cylinder, 30 ... Side wall part, 40 ... Side wall part, 41 ... Die part

Claims (4)

[Scope of utility model registration request] 1. An apparatus comprising a pressure dome 1 having a punch 6 and a hydraulic chamber into which the punch 6 is pushed, and a blank holder 7 for holding a blank W between the upper surface of the pressure dome 1, wherein the punch 6 is provided. While the tip profile portion 6a and the stepped portion profile portion 6b are provided at the end, the pressure dome 1 at the portion corresponding to the stepped portion profile portion 6b is formed with at least one slot 3 through which the tip communicates with the hydraulic chamber 2. Then, at the upper part of this groove hole 3, there is a die part 41 and subsequently to the side wall part for the hydraulic chamber.
A movable die 4 having 40 is arranged so as to be movable in the horizontal direction. Behind the movable die 4, as a first step, the hydraulic chamber 2 is moved so as to have a shape matching the tip profile portion 6a of the punch 6. The die 4 is moved forward, and the hydraulic chamber 2 is moved as the second stage.
2. An opposed hydraulic forming apparatus comprising movable die advancing / retreating means 5 for retracting the movable die 4 so as to have a shape that extends to the stepped profile portion 6b of the punch. 2. The counter hydraulic forming apparatus according to claim 1, wherein the groove, the movable die, and the movable die advancing / retracting means are provided in only one direction. 3. The counter hydraulic forming apparatus according to claim 1, wherein the groove, the movable die, and the movable die advancing / retracting means are provided in two or more directions. 4. The step profile portion is composed of a step profile member 6b 'which is connected to the piston of the cylinder 10 built in the punch 6 and cooperates with the die portion 41 of the movable die 4 and also serves as a blank holder. The counter-hydraulic molding device according to any one of claims 1 to 3, wherein the utility model is registered.