JP2001300780A - Press forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize an efficient driving by making use of the power of such driving source as a hydraulic cylinder for operating a pair of forming dies in opening and closing motions or the like in a way to optimize an output or a stroke at any moment of press forming. SOLUTION: In the press forming device, a pair of forming dies (an upper die 26 and a lower die 28) are independently movable in terms of the direction of closing and opening of the dies and each forming die is independently provided with a driving source. One of the driving sources (a first hydraulic cylinder 14) is so set that the preference is given to pressing force corresponding to the main pressing force which is necessary only for the moment of press forming and the other driving source (a second hydraulic cylinder 20) is so set that the preference is given to the stroke corresponding to the stroke which is necessary for securing a predetermined distance between the forming dies at an opening state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a press forming apparatus for performing processing such as bending, drilling, and drawing on a work such as a metal plate.

[0002]

2. Description of the Related Art A press forming apparatus includes at least a pair of forming dies (an upper die and a lower die), and generally has a structure in which a lower die is fixed and an upper die moves vertically. A hydraulic cylinder is used as a drive source for the motor. As a procedure of press molding by this apparatus, a predetermined work is set on a lower mold in a mold open state in which the upper mold is raised, then the upper mold is lowered to perform press molding, and the upper mold is raised again to raise the work ( Remove the molded article).

At the moment when a work is pressed, the main pressing force based on the output of the hydraulic cylinder is important, and if this force is insufficient, proper press forming cannot be performed. Also, when setting or removing a work in the mold open state as described above, it is difficult to perform the work unless a predetermined distance is secured between the upper mold and the lower mold. A drive stroke sufficient to secure the distance is required. Therefore, a hydraulic cylinder having a high output (large diameter) capable of outputting the main pressure and a long stroke (normally 30 cm or more) is used.

[0004]

However, as for the capacity of the hydraulic cylinder, a long stroke is unnecessary only at the moment of pressing, and a large output is unnecessary only for opening the mold. That is, in press molding, only at a certain moment, a hydraulic cylinder having a higher output or a longer stroke than necessary is used. In order to reduce the cycle time of press molding, it is necessary to move the upper die at high speed except for the moment of pressing, and as a result, the hydraulic cylinder must have the capability of high speed, high output, and long stroke. Is done. Further, as for the driving speed of the hydraulic cylinder, fine control is required according to the position of the upper die.

An object of the present invention is to solve the above-mentioned problems, and an object of the present invention is to reduce the ability of a drive source such as a hydraulic cylinder for performing a mold clamping / opening operation of a pair of molds at any moment of press molding. In view of this, it is necessary to always provide an appropriate output or stroke so that the drive can be performed without waste. Another object of the present invention is to simplify the speed control of the driving source in reducing the cycle time of press molding,
This is to eliminate the need for speed control according to the position of the mold.

[0006]

According to the present invention, there is provided a press forming apparatus, wherein a pair of forming dies are provided with respect to a mold clamping direction and a mold opening direction, respectively. It is movable and has an individual drive source. And one drive source is set to the pressing force priority capability that can correspond to the main pressing force necessary only at the moment of press molding,
The other drive source is set to a stroke-priority capability capable of coping with a stroke necessary to secure a predetermined distance between the molds in the mold open state. Since the two driving sources share the capability required for press molding in this way, the molding die can always be driven with an appropriate output or stroke at any moment of press molding without waste.

According to a second aspect of the present invention, there is provided the press forming apparatus according to the first aspect, wherein the molding die driven by the stroke-priority driving source is driven by the pressing force-priority driving source at the mold clamping position. A lock for receiving the main pressing force is possible. Therefore,
The drive source with the highest priority does not need an output to receive the main pressing force, and requires only the minimum capacity necessary to move the mold.

According to a third aspect of the present invention, there is provided the press forming apparatus according to the first aspect, wherein the stroke-priority driving source is set to be capable of driving at a higher speed than the pressing force-priority driving source. In this case, the cycle time of press molding can be reduced by moving the molding die driven by the driving source giving priority to the stroke at high speed. Further, the control of the driving speed is simple, and there is no need to finely control according to the position of the mold.

According to a fourth aspect of the present invention, there is provided the press forming apparatus according to the first aspect, wherein a high-output short-stroke hydraulic cylinder is used as a driving source for giving priority to the pressing force, and a low-pressure hydraulic cylinder is used as a driving source for giving priority to the stroke. A long stroke hydraulic cylinder is used at the output. This makes it possible to simplify the fluid pressure cylinder and the fluid pressure circuit, which are the driving sources of the molding die, and to make the whole apparatus compact.

[0010]

Embodiments of the present invention will be described below. 1 to 4 are front views each showing an outline of a press forming apparatus. As shown in these drawings, a bolster 18 and a first hydraulic cylinder 14, which is a driving source thereof, are arranged on the side of the base 12 in the press forming apparatus. A ram 24 and a second hydraulic cylinder 20, which is a driving source for the ram 24, are disposed on the side of the upper frame 13 supported by the column 10 and located above the base 12.

Therefore, the bolster 18 moves up and down together with the lower mold 28 through the movement of the cylinder rod 16 by the drive control of the first hydraulic cylinder 14, and the ram 24 rises through the movement of the cylinder rod 22 by the drive control of the second hydraulic cylinder 20. It moves up and down together with the mold 26. That is, in this press molding apparatus, the number of drive sources, which was one until now, is intentionally increased to two, and the bolster 18 and the ram 24 are individually raised and lowered. The first hydraulic cylinder 14 has a high output (large diameter) and short stroke, and the second hydraulic cylinder 20 has a low output (small diameter) and long stroke.

In the press forming apparatus, it is necessary to secure a main pressing force required for press forming a predetermined work (not shown) by the upper and lower dies 26 and 28 as the forming dies. On the other hand, in the mold opening state shown in FIG. 1, the work between the upper mold 26 and the lower mold 28 is performed in order to facilitate the work of setting the work on the lower mold 28 and taking out the formed work. Also, it is necessary to secure a predetermined distance.

Therefore, the first hydraulic cylinder 14, which is the driving source of the lower mold 28, is set to a high output capable of coping with the main pressing force and a pressing force priority capability such as a short stroke. On the other hand, the second hydraulic cylinder 20, which is a drive source of the upper die 26, has a stroke that is long enough to move the upper die 26 and secures a low output in order to secure the distance in the mold open state. Is set to the ability with the highest priority. Incidentally, in the present embodiment, the pressing force by the first hydraulic cylinder 14 is approximately 200 tons,
The stroke is about 70 mm, while the pressing force of the second hydraulic cylinder 20 is about 5 tons, and the stroke is about 215 mm.

The ram 24 on which the upper die 26 is provided
Is lockable to the column 10 in order to receive the pressing force applied from the bolster 18 based on the high output of the first hydraulic cylinder 14. In this structure for locking, the lock member 32 is switched between a standby position (FIGS. 1 and 2) and a lock position (FIGS. 3 and 4) by drive control of a lock cylinder 30 mounted on the column 10. It is supposed to be. The lock member 32 at the lock position is capable of contacting the upper surface of the ram 24 when the upper mold 26 is completely lowered to the mold clamping position.

Next, press molding will be described. First, a predetermined work is set on the lower mold 28 in the mold open state of FIG. 1 in which the distance is secured between the upper mold 26 and the lower mold 28. The lock member 3 at this time
2 is held at the standby position.

By operating a start switch for press forming, the ram 24 (upper die 26) is lowered by a long stroke to the position shown in FIG. 2 by driving the second hydraulic cylinder 20. When the ram 24 is completely lowered, the lock member 32 is switched to the lock position shown in FIG. Thereafter, although the bolster 18 (the lower mold 28) has a short stroke due to the driving of the first hydraulic cylinder 14, the bolster 18 is raised by the large force, and the mold is closed as shown in FIG. The large force that the ram 24 receives from the bolster 18 during this mold clamping is
2, the second hydraulic cylinder 20
The upper mold 26 and the lower mold 28 are pressed with a large pressing force even if the output is low, and the work is pressed.

When the press is completed, the first hydraulic cylinder 14 is driven to drive the bolster 18 (lower die 2).
8) is lowered as shown in FIG. 3, and the lock member 32 is switched from the lock position to the standby position.
Thereafter, the ram 24 (upper die 26) is raised by the driving of the second hydraulic cylinder 20, as shown in FIG. Then, the work after pressing is taken out and one cycle of press forming is completed.

As described above, the second hydraulic cylinder 20 has a long stroke and has a low output and is preferred to a stroke.
One that can be driven at a speed higher than 4 is used. In this embodiment, the speed of the second hydraulic cylinder 20 is set to approximately 280 m.
m / sec, and the speed of the first hydraulic cylinder 14 is 15 mm / sec. This shortens the time required for the ram 24 (upper die 26) to move between FIGS. 1 and 2, thereby shortening the cycle time of press molding.

As described above, the first hydraulic cylinder 14 and the second hydraulic cylinder 20 share the capacity required for press forming, so that each cylinder can be set to the minimum necessary capacity, and the bolster 18 and the ram 2
4 can always be driven with appropriate output, speed or stroke without waste. Further, it is not necessary to control the output and speed of both the hydraulic cylinders 14 and 20 during the operation thereof, so that individual control can be simplified.

While the preferred embodiment of the present invention has been described with reference to the drawings, this embodiment can be easily modified or modified without departing from the spirit of the present invention. For example, contrary to the above, bolster 18
The first hydraulic cylinder 14, which is the drive source of the (lower die 28), is set to the stroke priority capability, and the second hydraulic cylinder 20, which is the drive source of the ram 24 (the upper die 26), is set to the pressing force priority capability. Can also be set. Of course, these hydraulic cylinders 14 and 20 can be replaced with other hydraulic cylinders.

Further, a press forming apparatus of a type in which a plurality of pairs of forming dies are arranged in series (for example,
It is also possible to apply the technology of the present invention to US Pat. In this type of press forming apparatus, the stroke for clamping and opening the mold is larger than that of a normal press forming apparatus. Therefore, as described above, the press source is driven by the pressing force priority drive and the stroke priority driving source. It would be very advantageous to share the functions for molding.

[Brief description of the drawings]

FIG. 1 is a front view showing an open state of a press molding apparatus.

FIG. 2 is a front view showing a state where the ram of the press forming apparatus is lowered.

FIG. 3 is a front view showing a ram lock state of the press molding apparatus.

FIG. 4 is a front view showing a clamped state of the press molding apparatus.

[Explanation of symbols]

 14, 20 Hydraulic cylinder (drive source) 26 Upper die (molding die) 28 Lower die (molding die)

Claims (4)

[Claims] 1. A pair of molding dies are respectively movable in a mold clamping and mold opening direction, and each of them has a driving source, and one of the driving sources has a main pressing force required only at the moment of press molding. The driving force is set to a capacity that can be applied with priority, and the other drive source is set to a capacity that has priority to a stroke that can cope with a stroke necessary to secure a predetermined distance between the molds in the mold open state. Has press forming equipment. 2. The press forming apparatus according to claim 1, wherein the forming die driven by a stroke-priority driving source receives the main pressing force by the pressing-force priority driving source at the mold clamping position. Press equipment that can be locked for use. 3. The press forming apparatus according to claim 1, wherein the stroke-priority drive source is set to be capable of driving at a higher speed than the pressing force-priority drive source. 4. The press forming apparatus according to claim 1, wherein a high-output short-stroke fluid pressure cylinder is used as a driving source that gives priority to the pressing force, and a low-output long-stroke fluid is used as the driving source that gives priority to the stroke. Press forming equipment using pressure cylinders.