JP3022139B2 - Opposing hydraulic forming equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a single-acting opposed hydraulic forming apparatus capable of deep drawing press working of a complicated shape in a small number of steps.

[0002]

2. Description of the Related Art Conventionally, an opposing hydraulic forming apparatus has the following problems: (1) The forming limit of a product is improved, and deep drawing, which requires a plurality of steps in conventional drawing without using opposing hydraulic pressure, is performed in one step. (2) Since the blank material is pressed against the pressing punch by the opposing hydraulic pressure, the shape accuracy of the product is good.
(3) Even a product having a complicated shape can be molded with only one of a male type and a female type, and has features such as cost reduction.

[0003]

However, in the above-mentioned opposed hydraulic forming apparatus, the punch load of the press punch increases due to the pressure generated in the hydraulic chamber in comparison with the conventional drawing, so that a large punch can be formed. There is a problem that a driving force is required. SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems and to provide an opposing hydraulic forming apparatus capable of forming with a small driving force of a pressing punch.

[0004]

In order to solve the above-mentioned problems, a first means of the present invention is to provide a cylinder cylinder forming a hydraulic chamber at one end of a frame, and to provide a cylinder cylinder with an opening in the cylinder cylinder. the die is arranged, the other end of the frame, bra pressing and holding the periphery of the blank which is disposed on the die
A single-acting opposing hydraulic forming device provided with a press cylinder device that provides a press holder device and drives a press punch to a die side through a press shaft to project a blank material into a hydraulic chamber and forms the blank material. A hydraulic pressure adjusting device including a hydraulic pressure adjusting piston slidably fitted in a cylinder hole communicating with the hydraulic pressure chamber and a hydraulic pressure adjusting cylinder for driving the hydraulic pressure adjusting piston is provided on the press shaft. A cylinder device for additional pressure having a large-diameter piston shaft portion and a cylinder case slidably fitted on the piston shaft portion is provided, and the press shaft is acted on in the molding direction by acting on the piston shaft portion in the cylinder case. an additional hydraulic lines that connect the additional pressure chamber for driving the said hydraulic chamber is provided, the connected branch hydraulic lines to the compression chamber of the press cylinder unit, supplemental fluid pressure chamber of the additional hydraulic lines <br/> The additional pressure control valve for connection to the provided, the
The additional hydraulic pipe is provided with a liquid discharging means.

The second means is provided at one end of the frame.
In addition to providing a cylinder that forms the hydraulic chamber,
Place the die in the opening of the cylinder and open the other end of the frame.
To hold the blank material placed on the die by pressing around
DoBlank holder deviceAnd press shaft
The press punch is driven to the die side via the
A press cylinder device for projecting
Communicates with the hydraulic chamber in a single-gage counteracting hydraulic forming machine
Secondary pressure that slidably fits into the secondary pressure cylinder hole
Drive the piston and this secondary pressurized pistonSecondary pressurization
CylinderA secondary pressurizing device comprising:
Communicated withHydraulic tube for primary pressurizationA cylinder for press
Connected to the compression chamber sideHydraulic tube for pressToFor primary pressurization
Switching valveThrough the hydraulic pressure chamber sideHydraulic pressure for primary pressurization
tubeConnected via a discharge switching valve on the wayHydraulic discharge pipe
Equipped with a pressure control valve capable of controlling the hydraulic pressure in the hydraulic chamber
It is.

Further, a third means is to provide a cylinder cylinder for forming a hydraulic chamber at one end of the frame, arrange a die at the opening of the cylinder cylinder, and arrange the die at the other end of the frame on the die. A blank holder device for pressing and holding the periphery of the blank material was provided, and a press cylinder device for driving the press punch toward the die side via the press shaft to project the blank material into the hydraulic chamber and provided a press cylinder device. In a single-acting opposed hydraulic forming apparatus, a press shaft is separated into a drive press shaft on a press cylinder device side and a passive press shaft on a press punch side, and a drive piston portion provided at an end of the drive press shaft. When additional pressure silica having a passive piston section provided at an end portion of the passive press axis, and a cylinder case that fitted slidably on these drive piston unit and the passive piston portion Da device provided, connecting the pressure chamber and the additional hydraulic chamber for driving a passive press axis in the molding direction acts on the passive piston within the cylinder case additional
A hydraulic pipe is provided, and a switching valve for additional pressure is provided for connecting a branch hydraulic pipe connected to the compression chamber of the press cylinder device to the additional hydraulic chamber side of the additional hydraulic pipe . A pressure control valve capable of controlling the hydraulic pressure of a hydraulic chamber is provided in a discharge hydraulic pipe connected via a switching valve.

Furthermore, the fourth means is held in addition to the third means, the blank holder device, the hold cylinder provided on the other end side of the frame, is driven by the hold cylinder to press the blank And a holding switching valve (55) through a holding hydraulic pipe (51A) connected to the pressurized oil chamber (9d) of the hold cylinder (9a).
Via the hold switching valve (55)
Additional hydraulic pipe (12) connected to the chamber (42b) side and holding oil
The pressure pipe (51A) is configured to be connectable .

[0008]

In the first configuration, the hydraulic pressure supplied to the compression chamber of the press cylinder device is supplied via the branch hydraulic pipe to the additional hydraulic chamber of the additional cylinder device until the press punch abuts on the blank material. To supply. Then, when the press molding is started, the generated hydraulic pressure is applied to the piston shaft by supplying the hydraulic pressure of the hydraulic chamber pressurized by the press punch to the additional cylinder device via the additional hydraulic pipe. This reduces the load on the press shaft. When raising the opposing hydraulic pressure in the hydraulic chamber, the opposing hydraulic pressure can be raised by driving the hydraulic pressure adjusting piston by the hydraulic pressure adjusting cylinder . Therefore, the pressing force of the pressing punch can be greatly reduced.

Further, according to the second configuration, the press cylinder device is driven until the press punch contacts the blank, and the press punch contacts the blank.
By operating the switching valve for primary pressurization, only the hydraulic pressure of the hydraulic pressure chamber pressurized by the punch for press is introduced into the compression chamber of the cylinder device for press through the hydraulic pipe for primary pressurization , and the adjusting piston <br / By applying the hydraulic pressure of the hydraulic chamber, which is pressurized, to the piston of the press cylinder device, the press shaft is driven by the press sectional area of the press punch and the area difference of the piston to drive the press punch further. Indentation drawing can be performed. Therefore, it is possible to hydraulic pressure in the hydraulic pressure chamber by being introduced to the press cylinder unit <br/>, lower the customary drawing comparable to pressure of the press punch by the press cylinder unit.

According to the third configuration, the hydraulic pressure supplied to the compression chamber of the press cylinder device is supplied via the branch hydraulic pipe to the additional liquid of the additional cylinder device until the press punch abuts on the blank material. Supply to pressure chamber. When the pressure forming is started, the switching valve for additional pressure is operated, and the hydraulic pressure of the hydraulic chamber pressurized by the press punch flows into the additional pressure cylinder device via the additional hydraulic pipe, and the generated liquid The pressure is applied to the passive piston to reduce the load on the press shaft.
By driving the driving piston unit by the press cylinder device to pressurize the liquid in the additional hydraulic chamber, the press shaft is driven to push the press punch by the difference between the press sectional area of the press punch and the area of the piston. Can be molded. Therefore, the hydraulic pressure of the hydraulic pressure chamber is introduced into the additional pressure cylinder device, so that the pressing force of the press punch by the press cylinder device can be reduced as in the conventional drawing process, which is necessary for the first configuration. The need for a simple hydraulic adjustment cylinder is eliminated.

Further, according to the fourth configuration, by switching the hold switching valve during drawing, the hydraulic pressure of the lower hydraulic chamber is supplied to the pressurized oil chamber of the hold cylinder, and the pressure of the hold cylinder is reduced by the hydraulic pressure. In conjunction with the hydraulic pressure of the chamber, the pressing force of the holding member can be changed along a curve approximating the throttle resistance F _R.

[0012]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
An embodiment will be described with reference to FIG. In this embodiment, in a single-acting (die fixed type) opposed hydraulic forming apparatus, drawing is performed with a small pressing force by applying the opposed hydraulic pressure generated in a hydraulic chamber as a pressing force of a punch. It is.

That is, a cylinder tube 3 forming a hydraulic chamber 2 is fixed upright on the bed portion 1a of the frame 1,
A die 4 is arranged on the cylinder tube 3. In order to avoid mixing of metal chips and the like generated at the time of press working, the hydraulic chamber 2 faces the die 4 by the separation piston 5, and an upper hydraulic chamber 2a in which liquid such as water is stored, and oil in the lower part. It is separated from the lower hydraulic chamber 2b. At the bottom of the hydraulic chamber 2, there is provided a hydraulic pressure adjusting device 6 which is an example of a hydraulic pressure adjusting means. The hydraulic pressure adjusting device 6 is provided with a hydraulic pressure adjusting cylinder hole 6a communicating with the lower hydraulic pressure chamber 2b. And a hydraulic pressure adjusting piston 6 slidably fitted in the hydraulic pressure adjusting cylinder hole 6a.
and a hydraulic pressure adjusting cylinder 6d fixed to the bed 1a and driving a hydraulic pressure adjusting piston 6b via a piston rod 6c. The hydraulic pressure is supplied to and discharged from the hydraulic pressure adjusting cylinder 6d through an adjusting hydraulic pipe 23 interposed with an adjusting switching valve 22 from an adjusting hydraulic pump 21.

On the crown 1b of the frame 1, a press cylinder device 8 for supporting the press punch 7 so as to be able to move up and down is arranged, and the peripheral edge of the blank material W is pressed by a hold cylinder 9a via a holding member 9b. A blank holder device 9 for holding is provided. And
The press shaft 10 of the press punch 7 has an attachment according to the present invention .
A pressurizing cylinder device 11 is provided.

In this additional pressure cylinder device 11, a large-diameter piston shaft portion 10a is formed at an intermediate portion of the press shaft 10, and a slide shaft portion 10b is formed at an upper portion of the piston shaft portion 10a. Slide shaft 10
b is the crown portion 1b
It is fixed to. Slide holes 11b and 11c formed in the upper end surface and the lower end surface of the cylinder case 11a.
Respectively, the piston shaft portion 10a and the slide shaft portion 10
b is slidably fitted therein and has an additional hydraulic chamber 11d therein.
Are formed.

On the other hand, an additional hydraulic pipe 12 connected to the lower hydraulic chamber 2b is connected to an additional pressure
Connected to the additional hydraulic chamber 11 d of the cylinder device 11. Therefore, when the hydraulic pressure of the lower hydraulic pressure chamber 2b is supplied to the additional hydraulic pressure chamber 11d via the additional hydraulic pressure pipe 12, this hydraulic pressure is applied to the pressure receiving surface of the piston shaft 10a (the cross-sectional area of the piston shaft 10a).
(The cross-sectional area of the slide shaft portion 10b).
Can be urged in the pressing direction.

Reference numerals 14A and 14B denote a pair of press hydraulic tubes for supplying the press hydraulic pressure to the press cylinder device 8 via the press switching valve 16 with the hydraulic pressure generated by the press drive hydraulic pump 15; A branch hydraulic pipe 14a branched on the way from the press hydraulic pipe 14A connected to the compression chamber 8a of the device 8 is connected to the switching valve 13 for additional pressure and
The hydraulic line for press 14 is connected via an additional hydraulic line 12
A and an additional hydraulic chamber 11 d via the additional pressure switching valve 13.
The hydraulic pressure can be supplied to the hydraulic pressurizing chamber 2, and the hydraulic pressure for lowering the press punch 7 when the hydraulic chamber 2 is not compressed can be supplied. Further, a discharge hydraulic pipe 17 is connected to the additional hydraulic pipe 12 via a discharge switching valve (liquid discharging means) 18, and the additional hydraulic pressure chamber 11 when the press punch 7 returns (rises).
It is configured to discharge excess oil in d.

The molding procedure in the above configuration will be described. (1) The blank material W is set on the die 4. (2) Hold cylinder 9a of blank holder device 9
And the periphery of the blank material W is pressed by the holding member 9 b and held on the die 4. (3) The press switching valve 16 is switched from the position B to the position A to supply the hydraulic pressure of the press drive hydraulic pump 15 to the compression chamber 8a of the press cylinder device 8, and to switch the additional pressure switch valve 13 from the branch hydraulic pipe 14a. Hydraulic pressure is supplied to the additional hydraulic chamber 11d of the additional pressure cylinder device 11 via the additional pressurizing device, and the press punch 7 is lowered to contact the blank material W.

(4) The switching valve 13 for additional pressure is moved from the position B to the position A
The press punch 7 is further driven to start forming the blank material W by further driving, and the press punch 7 is pushed into the upper hydraulic chamber 2a together with the blank material W. As a result, the compressed hydraulic pressure of the lower hydraulic chamber 2b is reduced by the additional hydraulic pipe 12
The hydraulic pressure is introduced into the additional hydraulic chamber 11d through the pressure chamber, and the hydraulic pressure is applied to the pressure receiving surface of the piston shaft 10a to add the generated hydraulic pressure generated in the hydraulic chamber 2 to the press punch 7.

(5) At this time, if the cross-sectional area of the pressing of the blank material W into the hydraulic chamber 2 by the pressing punch 7 and the pressure receiving area of the piston shaft 10a are set to be the same, the upper and lower hydraulic chambers are set. Since the sum of the volumes of 2a and 2b and the additional hydraulic chamber 11d does not change, the opposing hydraulic pressure generated in the hydraulic chamber 2 is zero or extremely small. Therefore, the adjustment pressure switching valve 22 is switched from the position B to the position A to supply the hydraulic pressure to the compression chamber of the hydraulic pressure adjustment cylinder 6d, and raise the hydraulic pressure adjustment piston 6b to generate the opposing hydraulic pressure necessary for molding. Although the cross-sectional area of the press at the press position changes depending on the product shape, it is not necessary to set the cross-sectional area of the press by the press punch 7 and the pressure receiving area of the piston shaft portion 10a to be the same. If the area changes and changes largely from a state smaller than the pressure receiving area of the piston shaft portion 10a, the hydraulic pressure chamber 2
Is changed from a reduced pressure state to a pressurized state. By operating the hydraulic pressure adjusting device 6, the hydraulic pressure of the hydraulic pressure chamber 2 can be controlled to an appropriate hydraulic pressure.

At this time, when a product having a deep and complicated shape as shown in FIG. 6, for example, an oil pan W 'is drawn, if a high opposing hydraulic pressure is applied from the beginning, a reverse overhang phenomenon occurs. Since the excess thickness occurs and wrinkles occur in the steps, it is necessary to reduce the opposing hydraulic pressure at the time of initial molding in order to prevent this. At this time, by controlling the position of the hydraulic pressure adjustment piston 6b, the generated hydraulic pressure can be absorbed and the opposing hydraulic pressure can be easily controlled.

(6) When the molding is completed, first, the adjustment switching valve 22 is switched from the position A to the position B, the adjustment hydraulic pump 21 is in a no-load state, and the hydraulic pressure in the hydraulic chamber 2 is set to zero. Then, the holding member 9b is lifted by contracting the hold cylinder 9a, and the blank material W is released. Then, the switching valve 16 for the press is switched from the position A to the position C to supply the hydraulic pressure to the contraction chamber 8b of the cylinder device 8 for the press, and the piston shaft 10a is raised together with the punch 7 for the press. 11 d of oil is caused to flow into the lower hydraulic chamber 2 b via the additional hydraulic pipe 12. At this time, the blank W is pushed up, but the protruding portion of the blank W whose liquid amount does not return to the original amount is absorbed by the lowering of the hydraulic pressure adjusting piston 6b. The separation piston 5 rises, and the liquid amount in the hydraulic chamber 2 returns to the original amount . When reaching the blank material W contact position of the press punch 7, the discharge switching valve 18 is switched from the position B to the position A, and the oil in the additional hydraulic chamber 11d is discharged from the discharge hydraulic pipe 17.

(7) When the ascending is completed, the press switching valve 16 is switched from the C position to the B position to switch the press punch 7
To stop. Then, after taking out the blank material W, the hydraulic pressure adjustment piston 6b is raised to return to the original position, and the liquid level of the upper hydraulic pressure chamber 2a is returned to the original position. In the above-mentioned configuration, the force acting on the press punch 7: the drawing resistance (drawing load) F _R・ Same as above: the additional load due to the fluid pressure F _P・ the force applied to the press punch 7: the pressing force F by the press cylinder device 8 _O・ Same as above: Assuming the additional force F _A by the additional pressure cylinder device 11, Here, ・ Pushing cross-sectional area of press punch 7: A _P (cross-sectional area of press punch 7 + plate thickness of blank material W) ・ Pressure receiving area of piston shaft portion 10a of additional pressure cylinder device 11: A _A・ liquid When the hydraulic pressure generated in the pressure chamber 2 is P, and F _P = A _P · P A _P ≒ A _A is set, F _A = A _A · P ≒ A _P · P When this is substituted into the equation, F _O ≒ F _R , and the pressing force F _O ≒ F by the press cylinder device 8
_R : Drawing resistance, which is almost the same as conventional drawing (normal pressing other than the opposing hydraulic press).

When A _P ≒ A _A is set as described above, the upper hydraulic chamber 2a, the lower hydraulic chamber 2b, and the additional hydraulic chamber 11d form a closed circuit via the additional hydraulic pipe 12, so that the liquid volume is Does not change, and merely pressing the press punch 7 into the hydraulic chamber 2 does not generate hydraulic pressure in the hydraulic chamber 2. Therefore, the hydraulic pressure in the hydraulic pressure chamber 2 can be increased by operating the hydraulic pressure adjusting piston 6b of the hydraulic pressure adjusting device 6.

The amount of movement of the press punch 7: δ _{P The} amount of movement of the hydraulic pressure adjusting piston 6b: δ _C The cross-sectional area of the hydraulic pressure adjusting piston 6b: A _{C The} amount of liquid compression (generates hydraulic pressure) compression volume required to: When _{ΔV, ΔV = a P · δ} P + a C · δ C -A a · δ P ∴A C · δ C = ΔV + (a a -A P) · δ P therefore, When A _P ≒ A _A , A _C · δ _C ≒ ΔV, and it is sufficient to compress only the facing hydraulic pressure necessary for drawing, and the cross-sectional area A _C and the moving amount δ of the hydraulic pressure adjustment piston 6b
_C may be small.

According to the above-described embodiment, the pressurizing punch 7 is pushed into the upper hydraulic chamber 2a together with the blank material W and the increased hydraulic pressure is transmitted to the lower hydraulic chamber 2b via the separation piston 5. The hydraulic pressure of the lower hydraulic pressure chamber 2b is caused to flow into the additional hydraulic pressure chamber 11d through the additional hydraulic pressure pipe 12 to reduce the hydraulic pressure to the piston shaft 10a.
Can be applied to the pressure receiving surface of the press punch 7, and the pressing force of the press punch 7 by the press cylinder device 8 can be made substantially the same as in the conventional drawing.
Can be greatly reduced.

FIG. 2 shows that the function of the additional pressure cylinder device 11 in the first embodiment is also used for the press cylinder device 8, and the pressing force of the press punch 7 by the press cylinder device 8 is applied to the hydraulic pressure adjustment device 6 ( In the present embodiment, a second embodiment performed by the secondary pressurizing device 36 is shown. The same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

At the bottom of the hydraulic pressure chamber 2, a secondary pressurizing device 36 (an example of a secondary pressurizing means) (the hydraulic pressure adjusting device 6 of the first embodiment) is provided.
And the secondary pressurizing device 36.
Is a secondary pressurizing cylinder hole 36a communicating with the lower hydraulic chamber 2b.
And a secondary pressurizing piston 36b slidably fitted in the secondary pressurizing cylinder hole 36a, and a secondary pressurizing device fixed to the bed 1a and driving the secondary pressurizing piston 36b via a piston rod 36c. And a pressure cylinder 36d. The hydraulic pressure is supplied to and discharged from the secondary pressurizing cylinder 36d from a secondary pressurizing hydraulic pump 37 via a secondary pressurizing hydraulic pipe 39 having a secondary pressurizing switching valve 38 interposed therebetween.

In the first embodiment, a press cylinder device 8 is used in place of the additional pressure cylinder device provided on the press shaft 10. That is, the primary pressurization switching valve 31 between the press switch valve 16 of the press hydraulic pipe 14A connected to the compression chamber 8a of the press cylinder unit 8 compression chamber 8a is interposed, the primary pressurization switching
A primary pressurizing hydraulic tube 32 connected to the lower hydraulic chamber 2b is connected to the switching valve 31. A discharge switching valve 33 is interposed in the primary pressurizing hydraulic pipe 32, and a hydraulic discharge pipe 34 connected to the discharge switching valve 33 is provided with a pressure capable of adjusting the hydraulic pressure in the hydraulic chamber 2. A control valve 35 is interposed and connected to the other hydraulic pipe for press 14B.

The molding procedure in the above configuration will be described. (1) The blank material W is set on the die 4. (2) Hold cylinder 9a of blank holder device 9
And the periphery of the blank material W is pressed by the holding member 9 b and held on the die 4. (3) The switching valve 16 for the press is switched from the position B to the position A, and the switching valve 31 for the primary pressurization is set to the position B to supply the hydraulic pressure of the press drive hydraulic pump 15 to the compression chamber 8a of the cylinder device 8 for the press. The punch 7 is lowered to contact the blank material W.

(4) When the blank material W is pressed and formed into the upper hydraulic chamber 2a by the press punch 7, an opposing hydraulic pressure is generated. At this time, if it is desired to set the opposing hydraulic pressure at the time of initial molding to be low, the discharge switching valve 33 is held at the position A and the pressure control valve 35 is operated to lower the opposing hydraulic pressure of the hydraulic chamber 2. Can be held. (5) Upon reaching the predetermined position, the discharge switching valve 33 is switched from the position A to the position B, and at the same time, the primary pressurizing switching valve 3 is switched.
1 is switched from the B position to the A position, the switching valve 16 for press is switched from the A position to the neutral B position, and the press drive hydraulic pump 15 is put in a no-load state.
As a result, the lower hydraulic chamber 2b and the compression chamber 8a of the press cylinder device 8 are communicated via the primary pressurizing hydraulic tube 32. Then, the secondary pressurizing switching valve 38 is switched from the position B to the position A, and the piston rod of the secondary pressurizing cylinder 36d is switched.
The lower hydraulic chamber 2b is pressurized by raising the secondary pressurizing piston 36b by causing the secondary pressurizing piston 36b to elevate, thereby increasing the opposing hydraulic pressure. Here, since the relationship between the pressing cross-sectional area of the press punch 7: A _P and the pressure receiving area of the piston of the press cylinder device 8: A ₀ is set to A _P <A ₀ , the press punch 7 is It can be driven toward the hydraulic chamber 2 to continue drawing.

(6) When the molding is completed, the secondary pressurizing switching valve 38 is switched from the position A to the neutral position B to put the secondary pressurizing pump 37 in a no-load state, and the opposing hydraulic pressure of the hydraulic pressure chamber 2 is reduced. Set to 0. Then, the hold cylinder 9a is contracted to lift the holding member 9b. Next, the switching valve for press 16
Is switched to the C position to supply hydraulic pressure to the contraction chamber 8b of the press cylinder unit 8 from B position, increasing the press punch 7, the oil primary pressurizing hydraulic pipes in the compression chamber 8a 32
Through the lower hydraulic pressure chamber 2b, the separation piston 5 is pushed up by this pressure, and the secondary pressurizing piston 36b is pushed down.

(7) When the separation piston 5 and the secondary pressurizing piston 36b return to their original positions, the primary pressurizing switching valve 3
1 is switched from the position A to the position B, and the oil in the compression chamber 8a is discharged through the switching valve 16 for press. In the above structure, - throttle resistance (throttle load): F _R-hydraulic by adding load: F _P · by the press cylinder unit 8 pressure: pressure-receiving area of the F _O-press cylinder unit 8: A for _O-Press Assuming that the press-in cross-sectional area of the punch 7 is A _P and the hydraulic pressure generated in the hydraulic chamber 2 is P, F _O = F _R + F _P , A _O・ P = F _R + A _P・ P, and P = F _R / (A _O -A _P ) ..., the hydraulic pressure P is the throttle resistance F
_It is proportional to _R.・ Pressing force of the secondary pressurizing piston 6b: F _C・ Cross-sectional area of the secondary pressurizing piston 6b: A _C , substituting the formula into F _C = A _C・ P, F _C = F _R・ A _C / (A _O −A _P )..., And the pressing force F _C of the secondary pressurizing piston 36b is also proportional to the throttle resistance F _R.

Furthermore, and transfer of the press punch 7 when the amount of movement of the [delta] _P-secondary pressure piston 36b: cross-sectional area of the [delta] _C-secondary pressure piston 36b: compression of the A _C-Liquid : When _{ΔV, ΔV = a P · δ} P + a C · δ C -A O · δ P = a C · δ C - (a O -A P) δ P _{becomes, ∴A C · δ C = ΔV} + ( A _O -A _P ) δ _P , δ _C = ΔV / A _C + δ _P · (A _O -A _P ) / A _C ΔV is extremely small, so δ _C ≒ δ _P · (A _O -A _P ) / a _C ... where, a _O -A set to _P ≒ a _C, from the expression, F _C ≒ F _R Thus, pressure F _O by pressing cylinder device 8
It can be understood that the pressing force of the press punch 7 which is almost the same as that of the conventional drawing process is sufficient.

By setting A _O -A _P <A _C , the opposing hydraulic pressure of the hydraulic chamber 2 can be increased, and the movement amount δ _C of the secondary pressurizing piston 36b can be small. According to the above-described embodiment, the pressurizing punch 7 is pushed into the upper hydraulic chamber 2a together with the blank material W, and the increased hydraulic pressure is applied to the separation piston 5
To the lower hydraulic chamber 2b via the
Cylinder for press 8 via hydraulic tube 32 for primary pressurization
And the hydraulic pressure in the hydraulic pressure chamber 2 pressurized by the secondary pressurizing piston 36b is applied to the pressure receiving surface of the piston shaft portion 10a to drive the press punch 7. The pressing force of the press punch 7 by the press cylinder device 8 can be reduced as low as the conventional drawing process.

FIG. 3 shows a pressure control valve 41 provided on the additional hydraulic pipe 12 instead of the fluid pressure adjusting device 6 of the first embodiment, and a fluid pressure adjusting cylinder device is eliminated, thereby replacing the fluid pressure adjusting cylinder device. In order to use the additional pressure cylinder device as the fluid pressure adjusting means, the press shaft 10 is separated and connected so as to be interlocked via the oil in the additional pressure cylinder device 42. The same members as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

That is, the discharge hydraulic pipe 17 is provided with a pressure control valve 41 for controlling the hydraulic pressure of the hydraulic chamber 2 to be low at the initial stage of the pressure molding. The press shaft is separated into an upper press shaft (drive press shaft) 10A driven by the press cylinder device 8, and a lower press shaft (passive press shaft) 10B to which the press punch 7 is attached.
They are linked and connected by an additional pressure cylinder device 42 provided at the separation portion. That is, the cylinder case 4 of the additional pressure cylinder device 42 is provided at the lower end of the upper press shaft 10A.
A drive piston 43 is formed in the inside of the lower press shaft 10B, and a passive piston 44 is slidably fitted in the cylinder case 42a. Therefore, the upper press shaft 10A and the lower press shaft 10B are interlocked and connected via the oil in the additional hydraulic chamber 42b, and the press piston 7 can be driven via the passive piston portion 44 by the protrusion of the drive piston portion 43. it can. Reference numeral 45 denotes an additional pressure discharge pipe connected from the pressure reducing chamber 42c of the additional pressure cylinder device 42 to the press hydraulic pipe 14B on the contraction chamber side.

The molding method in the above configuration will be described. (1) The blank material W is set on the die 4. (2) Hold cylinder 9a of blank holder device 9
And the periphery of the blank material W is pressed by the holding member 9 b and held on the die 4. (3) By switching the press switching valve 16 from the position B to the position A and supplying the hydraulic pressure of the press drive hydraulic pump 15 to the compression chamber 8a of the press cylinder device 8 and driving the upper press shaft 10A, the additional hydraulic pressure is increased. The chamber 42b is pressurized, the lower press shaft 10B is driven via the passive piston portion 44, and the press punch 7 is lowered to abut the blank material W.

(4) The press punch 7 is further driven to start forming the blank material W, and by switching the additional pressure switching valve 13 from the position B to the position A, the hydraulic pressure of the lower hydraulic chamber 2b is added. The pressure is sent to the additional hydraulic chamber 42b through the hydraulic pipe 12, and the pressure of the press cylinder device 8 acts on the additional hydraulic chamber 42b, so that the press punch 7 is pushed into the upper hydraulic chamber 2a together with the blank material W. . This allows
The compressed hydraulic pressure of the lower hydraulic chamber 2b is caused to flow into the additional hydraulic chamber 42b via the additional hydraulic pipe 12, and the hydraulic pressure is applied to the passive piston portion 44 to reduce the pressure generated in the hydraulic chamber 2 It is added to the punch 7 for press.

When the opposing hydraulic pressure during the initial molding is to be kept low, the discharge switching valve 18 is set to the position B and the additional hydraulic line 1 is set.
2 is connected to the discharge hydraulic pipe 17 and the pressure control valve 41
, The opposing hydraulic pressure in the hydraulic chamber 2 can be kept low. Then, when the draw forming reaches a predetermined amount, the discharge switching valve 18 is switched from the position B to the position A, and the lower hydraulic chamber 2b and the additional hydraulic chamber 42b are communicated with each other. Increase the opposing hydraulic pressure.

(5) When the molding is completed, the hold cylinder 9a is contracted to lift the holding member 9b, and the blank material W is released. Further, the switching valve 16 for the press is switched from the position A to the position C to supply the hydraulic pressure to the contraction chamber 8b of the cylinder device 8 for the press and to the pressure reducing chamber 42c of the cylinder device 42 for the additional pressure via the additional pressure discharge pipe 45. By supplying hydraulic pressure and raising the lower press shaft 10B together with the press punch 7, the oil in the additional hydraulic chamber 42b flows into the lower hydraulic chamber 2b via the additional hydraulic pipe 12. At this time, the blank material W is pushed up to secure a liquid amount. When the press punch 7 reaches the original contact position of the blank material W, the switching valve 13 for additional pressure is switched from the position A to the position B, and the oil in the additional hydraulic chamber 42b is discharged from the branch hydraulic pipe 14a.

Here, the lower hydraulic chamber 2b and the additional hydraulic chamber 42b
Is a closed circuit, the pressure receiving area of the passive piston portion 44: A _C is set to be larger than the pressing cross-sectional area of the pressing punch 7: A _P (A _C > A _P ), so that the driving piston portion 43 adds By slightly pressing the hydraulic chamber 42b, the lower press shaft 10B can be driven in the forming direction to continue drawing. The pressure receiving area A of the drive piston 43
_By setting _B > A _C -A _P , the drawing speed can be increased by increasing the driving speed of the lower press shaft 10B from the driving speed of the upper press shaft 10A.

Further, the driving piston 43 is brought into contact with the passive piston 44 so as to reduce the pushing force of the upper press shaft 10A: F _O and the throttle resistance: F _R , as in the first embodiment.
It can be formed with an indentation force comparable to that of conventional draw forming of a slightly larger degree. According to the above embodiment, the press punch 7 is pushed into the upper hydraulic chamber 2a together with the blank material W, and the increased hydraulic pressure is applied to the lower hydraulic chamber 2 via the separation piston 5.
transmitted to b, and introduced into the additional hydraulic chamber 42b of the additional pressure cylinder 42 through the hydraulic additional hydraulic lines 12 of the lower liquid chamber 2b, further through the drive piston 43 by pressing cylinder unit 8 adds By pressurizing the hydraulic chamber 42b, the press punch 7 can be driven to perform drawing, and the pressing force of the press punch 7 by the press cylinder device 8 can be reduced as low as the conventional drawing. .

FIG. 4 shows a fourth embodiment obtained by modifying the third embodiment. In a hydraulic forming apparatus, a blank holder device 9
The holding pressure of the blank material W by the hold cylinder 9a is desirably controlled along a curve approximating the drawing resistance F _R in consideration of slippage of the blank material W. on the other hand,
As shown in FIG. 5, the hydraulic pressure P of the hydraulic pressure chamber 2 generated during the draw forming shows a variation course substantially similar to the change of the throttle resistance F _R , so that the hydraulic pressure of the hydraulic pressure chamber 2 is introduced to the hold cylinder 9a. By doing so, the holding pressure by the hold cylinder 9a is controlled to an appropriate pressure. The same members as those in the third embodiment are denoted by the same reference numerals, and description thereof will be omitted.

The hold cylinder 9a is connected to the hold hydraulic pipes 51A and 51B, and is connected to the hold drive switching valve 52.
Hydraulic pump for hold (other hydraulic source is acceptable) 5
3 is supplied with hydraulic pressure. A hold switching valve 55 is interposed in the holding hydraulic pipe 51A connected to the pressurized oil chamber 9d of the hold cylinder 9a, and branches off from the additional hydraulic pipe 12 between the additional pressure switching valve 13 and the additional hydraulic chamber 42b. The branched additional hydraulic pipe 54 is connected to the hold switching valve 55.

In the above construction, the hydraulic pressure of the lower hydraulic chamber 2b is supplied to the pressurized oil chamber 9d of the hold cylinder 9a by switching the hold switching valve 55 from the position B to the position A during drawing. The pressing force of the holding member 9b can be changed along a curve approximating the throttle resistance F _R by linking the pressing force of the holding member 9b with the oil pressure of the lower hydraulic chamber 2b.

[0047]

As described above, according to the first configuration of the present invention, the hydraulic pressure supplied to the compression chamber of the press cylinder device is transferred to the branch hydraulic pipe until the press punch abuts against the blank material. To the additional hydraulic chamber of the additional cylinder device. Then, when the press molding is started, the generated hydraulic pressure is applied to the piston shaft by supplying the hydraulic pressure of the hydraulic chamber pressurized by the press punch to the additional cylinder device via the additional hydraulic pipe. This reduces the load on the press shaft. To increase the opposing hydraulic pressure in the hydraulic chamber, adjust the hydraulic pressure
The opposing hydraulic pressure can be increased by driving the hydraulic pressure adjusting piston by the cylinder . Therefore, the pressing force of the pressing punch can be greatly reduced.

Further, according to the second configuration, the press cylinder device is driven until the press punch abuts on the blank material until the press punch abuts on the blank material.
By operating the switching valve for primary pressurization, only the hydraulic pressure of the hydraulic pressure chamber pressurized by the punch for press is introduced into the compression chamber of the cylinder device for press through the hydraulic pipe for primary pressurization , and the adjusting piston <br / By applying the hydraulic pressure of the hydraulic chamber, which is pressurized, to the piston of the press cylinder device, the lower press shaft is driven and the press punch is driven by the difference between the pressing cross-sectional area of the press punch and the area of the piston. Further, indentation drawing can be performed. Thus, the press cylinder instrumentation fluid pressure of the hydraulic chamber
The pressure applied to the press punch by the press cylinder device can be reduced as much as the conventional drawing process.

According to the third configuration, the hydraulic pressure supplied to the compression chamber of the press cylinder device is supplied via the branch hydraulic pipe to the additional liquid of the additional cylinder device until the press punch abuts on the blank material. Supply to pressure chamber. When the pressure forming is started, the switching valve for additional pressure is operated, and the hydraulic pressure of the hydraulic chamber pressurized by the press punch flows into the additional pressure cylinder device via the additional hydraulic pipe, and the generated liquid The pressure is applied to the passive piston to reduce the load on the press shaft.
By driving the driving piston unit by the press cylinder device to pressurize the liquid in the additional hydraulic chamber, the press shaft is driven to push the press punch by the difference between the press sectional area of the press punch and the area of the piston. Can be molded. Therefore, the hydraulic pressure of the hydraulic pressure chamber is introduced into the additional pressure cylinder device, so that the pressing force of the press punch by the press cylinder device can be reduced as in the conventional drawing process, which is necessary for the first configuration. The need for a simple fluid pressure adjusting device is eliminated.

Further, according to the fourth configuration, the hydraulic pressure of the lower hydraulic chamber is supplied to the pressurized oil chamber of the hold cylinder by switching the hold switching valve during drawing, and the pressing force of the hold cylinder is reduced by the hydraulic pressure. In conjunction with the hydraulic pressure of the chamber, the pressing force of the holding member can be changed along a curve approximating the throttle resistance F _R.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a first embodiment of an opposing hydraulic forming apparatus according to the present invention.

FIG. 2 is a configuration diagram showing a second embodiment of the opposed hydraulic forming apparatus according to the present invention.

FIG. 3 is a configuration diagram showing a third embodiment of the opposed hydraulic forming apparatus according to the present invention.

FIG. 4 is a configuration diagram showing a fourth embodiment of the opposed hydraulic forming apparatus according to the present invention.

FIG. 5 is a graph showing a relationship between a drawing load and a punch forming amount described in a fourth embodiment.

6 (a) and 6 (b) are a plan view and a side view of an oil pan showing an example of a product by the opposed hydraulic forming apparatus.

[Explanation of symbols]

W Blank material 1 Frame 1a Bed 1b Crown 2 Hydraulic chamber 2a Upper hydraulic chamber 2b Lower hydraulic chamber 3 Cylinder cylinder 4 Die 5 Separation piston 6 Hydraulic pressure adjusting device 6a Hydraulic pressure adjusting cylinder hole 6b Hydraulic pressure adjusting piston 6d Hydraulic pressure adjusting cylinder 7 Press punch 8 Press cylinder device 8a Compression chamber 9 Blank holder device 9a Hold cylinder 9b Holding member 9d Pressurized oil chamber 10 Press shaft 10A Upper press shaft 10B Lower press shaft 10a Piston shaft portion 10b Slide shaft portion Reference Signs List 11 Cylinder device for additional pressure 11a Cylinder case 11d Additional hydraulic chamber 12 Additional hydraulic tube 13 Switching valve for additional pressure 14A, 14B Hydraulic tube for press 14a Branch hydraulic tube 15 Press-driven hydraulic pump 16 Press switching valve 17 Discharge hydraulic tube 18 Discharge Switching valve 21 adjustment hydraulic pump 22 Sei switching valve 31 primary pressurizing switching valve 32 primary pressurizing hydraulic pipes 33 discharge switching valve 34 the hydraulic pressure exhaust pipe 35 pressure control valve 36 a secondary pressure device 36a secondary pressure cylinder bore 36b secondary pressure piston 36d two Next pressurizing cylinder 41 Pressure control valve 42 Cylinder device for additional pressure 42a Cylinder case 42b Additional hydraulic chamber 43 Drive piston unit 44 Passive piston unit 51A Hydraulic pipe for hold 51B Hydraulic pipe for hold 52 Switching valve for hold drive 53 Hydraulic pump for hold 54 additional hydraulic line for branching 55 switching valve for hold

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-53-128566 (JP, A) JP-A-7-256353 (JP, A) JP-A 7-256354 (JP, A) (58) Survey Field (Int.Cl. ⁷ , DB name) B21D 22/20 B21D 24/08 B30B 15/22

Claims (4)

(57) [Claims] A cylinder (3) forming a hydraulic chamber (2) is provided at one end of a frame (1).
Place the die (4) in the opening of the frame, on the other end of the frame (1),
In addition to providing a blank holder device (9) for pressing and holding the periphery of the blank material (W) arranged on the die (4), the punch (7) for pressing is pressed via the press shaft (10) to the die (4) In a single-acting opposing hydraulic forming device equipped with a press cylinder device (8) for driving the blank material (W) into the hydraulic pressure chamber (2) by projecting it into the hydraulic pressure chamber (2), A hydraulic pressure adjustment piston (6b) slidably fitted into the communicating cylinder hole (6a); and a hydraulic pressure adjustment piston (6
A hydraulic pressure adjusting device (6) including a hydraulic pressure adjusting cylinder (6d) for driving b) is provided, and a large-diameter piston shaft portion (10a) formed on the press shaft (10).
And a cylinder case for additional pressure having a cylinder case (11a) slidably fitted to the piston shaft (10a).
(11), and an additional hydraulic chamber (11) that acts on the piston shaft (10a) in the cylinder case (11a) to drive the press shaft (10) in the forming direction.
d) said liquid chamber (2) for connecting the additional hydraulic pipe (12) is provided, connected to the compression chamber of the press cylinder unit (8) (8a) min
The hydraulic line (14a) is connected to the additional hydraulic chamber (11 ) of the additional hydraulic line (12).
An opposing hydraulic forming apparatus, characterized in that an additional pressure switching valve (13) connected to the d) side is provided, and a liquid discharging means (18) is provided in the additional hydraulic pipe (12) . 2. A cylinder cylinder (3) forming a hydraulic chamber (2) is provided at one end of a frame (1).
Place the die (4) in the opening of the frame, on the other end of the frame (1),
In addition to providing a blank holder device (9) for pressing and holding the periphery of the blank material (W) arranged on the die (4), the punch (7) for pressing is pressed via the press shaft (10) to the die (4) In a single-acting opposing hydraulic forming device equipped with a press cylinder device (8) for driving the blank material (W) into the hydraulic pressure chamber (2) by projecting it into the hydraulic pressure chamber (2), A secondary pressurizing piston (36b) slidably fitted into the communicating secondary pressurizing cylinder hole (36a), and a secondary pressurizing cylinder (36d) for driving the secondary pressurizing piston (36b). A secondary pressurizing device (36) provided with : A primary pressurizing hydraulic pipe (32) communicated with the hydraulic chamber (2),
Connected to the compression chamber (8a) side of the press cylinder device (8)
It is connected to a pressurizing hydraulic pipe (14A) via a primary pressurizing switching valve (31) , and a discharge switching valve (33) in the middle of the primary pressurizing hydraulic pipe (32) on the hydraulic pressure chamber (2) side. A hydraulic pressure discharge pipe (34) connected with a pressure control valve (35) capable of controlling the hydraulic pressure of the hydraulic pressure chamber (2). 3. A hydraulic chamber (2) is formed at one end of the frame (1).
Cylinder cylinder (3)
Place the die (4) in the opening of the frame, on the other end of the frame (1),
Press around the blank (W) placed on the die (4) to keep it
HaveBlank holder device (9)Along with the
Press the punch (7) toward the die (4) through the less shaft (10).
Move the blank (W) into the hydraulic chamber (2) to form it.
Single-acting counter-hydraulic forming with a cylinder device (8)
In the device, the press shaft is connected to the press cylinder device (8) side.Drive press shaft
(10A) and press punch sidePassive press shaftSeparated into (10B)
And thisDrive press shaft(10A)
Ston part (43),Passive press shaft(10B)
The dynamic piston (44), these drive pistons (43) and
Cylinder case slidably fitted to the passive piston (44)
And an additional pressure cylinder device (42) equipped with a passive piston (44) in the cylinder case (42a).
Liquid to drive the passive press shaft (10B) in the forming direction
Connecting the pressure chamber (42b) and the hydraulic chamber (2)Additional hydraulic pipe (12)
And was connected to the compression chamber (8a) of the press cylinder device (8).Minute
Ki Oil Pipe (14a)Into the additional hydraulic chamber (42) of the additional hydraulic pipe (12).
b) an additional pressure switching valve (13) connected to the side is provided,Additional hydraulic pipe (12)Via the discharge switching valve (18)
ConnectedDischarge hydraulic pressure Tube (17)The hydraulic pressure in the hydraulic chamber (2)
Opposed, characterized by providing a controllable pressure control valve (41)
Hydraulic molding equipment. 4. A blank holder device (9) comprising: a holding cylinder (9a) provided at the other end of the frame; and a holding member ( 9) driven by the holding cylinder (9a ) to press the blank material (W). 9b) and a hose connected to the pressurized oil chamber (9d) of the hold cylinder (9a).
The hold switching valve (55) is interposed in the hydraulic
Through the hold switching valve (55) and the additional hydraulic chamber (4
2b) Additional hydraulic line (12) connected to the side and hydraulic line for hold
The opposing hydraulic forming apparatus according to claim 3, wherein the apparatus is configured to be connectable to the (51A) .