JPH0340679B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention is applicable to powder molding presses, synthetic resin mold presses and injection molding machines, metal plate molding presses, cutting machines and punching machines for metal plates, etc. This invention relates to a platform opening/closing device for a processing machine in which molds and cutters are attached to the upper and lower or front and rear platforms and processing is performed by moving one or both of the platforms.

[Conventional technology]

FIG. 4 shows an example of a conventional press machine.

In this figure, 1 is a frame, 2 is a fixed base plate at the bottom of the frame 1, and 3 is a movable base plate.

The movable base plate 3 is moved up and down by a large-diameter main cylinder 4 fixed at the center of the upper part of the frame 1 and small-diameter auxiliary cylinders 5 provided on the left and right sides of the main cylinder 4.
It is connected to the top of the.

In this press machine, when the movable base plate 3 is in the raised position shown in the figure, the working fluid is first sent to the upper chamber of the auxiliary cylinder 5 at high speed, and the movable base plate 3 is lowered at high speed by the auxiliary cylinder 5. When it comes into contact with the workpiece 8 on the fixed base plate 2, the sequence valve in the piping to the main cylinder 4 acts, applying high hydraulic pressure to the main cylinder 4, and further lowering the movable base plate 3 with a large force. Then, the workpiece 8 on the base plate 2 is processed using a mold or the like.

In this case, since the volume of the main cylinder 4 is large,
When the base plate 3 is lowered, a large amount of liquid in the head tank 6 is sucked into the main cylinder 4, and after machining, the movable base plate 3
Even when the main cylinder 4 rises, a large amount of liquid in the main cylinder 4 must be returned to the head tank 6.

[Problem that the invention seeks to solve]

In the case of a press machine using a conventional hydraulic cylinder as described above, the large diameter main cylinder also has the same long stroke as the auxiliary cylinder.

In general, large-diameter cylinders have longer strokes and significantly higher manufacturing costs, which hinders efforts to reduce weight and cost.

Since the volume of the main cylinder is large, the compressibility of the working fluid has a large effect, and it takes time to increase the pressure in the pressurization process, and it takes time to release the pressure even during the depressurization process, so the loss time is large overall.

A head tank 6 and a large-capacity pump for high-speed feeding are required to move a large amount of liquid into and out of the main cylinder, which has a large diameter and a long stroke. For this reason, it has become larger,
The weight is also large, and since there is a large flow passage section, there is a large energy loss due to pressure loss such as flow resistance.

To alleviate the shock of sudden pressure drop when discharging high-pressure fluid in a large-capacity main cylinder,
A complex operation is required, in which the pressure relief circuit is first activated to drain a small amount of fluid, gradually reducing the pressure in the main cylinder, and then to start draining the main cylinder, and the hydraulic circuit and the control circuit becomes complicated.

Since the movable platform is held only by hydraulic pressure, there have been problems such as difficulty in holding the position for a long time due to internal leakage from each valve in the hydraulic circuit.

[Means for solving problems]

In order to solve the above problems, the present invention connects the piston rod of a hydraulically operated auxiliary cylinder with a small diameter and long stroke to one base plate of a press machine, etc., and the outer periphery of this piston rod has its own elastic Hydraulic mechanical locking consisting of a sleeve made of an elastically deformable material that tightens and locks the rod, and a hydraulic circuit that applies hydraulic pressure between the rod and sleeve to expand the sleeve and release the lock, if necessary. A piston rod of a hydraulically operated main cylinder having a large diameter and short stroke is connected to the other base plate.

[Effect]

This invention has the above-mentioned configuration. Initially, with the hydraulic mechanical locking device loosened, an auxiliary cylinder with a small diameter and long stroke is operated to move one of the base plates at high speed, and the workpiece on this base plate is moved at high speed. Immediately before contacting the other base and starting pressing or cutting, the mechanical locking device acts to fix one of the bases by fixing the rod that moves together with the auxiliary cylinder. Then, hydraulic pressure is applied to the main cylinder, and the other base moves to perform processing such as pressing and cutting.

〔Example〕

In the embodiment shown in FIGS. 1 and 2, 11 is an auxiliary cylinder with a small diameter and long stroke fixed to the lower part of the frame 13, 12 is a main cylinder with a large diameter and short stroke fixed to the upper part of the frame 13, and 14, 15
are upper and lower base plates driven by respective cylinders 11 and 12.

Rods 16 are fixed to the lower portions of both sides of the lower base plate 14, and hydraulic mechanical locking devices A are provided on the outside thereof.

In the device A, both ends of a sleeve 18 made of an elastically deformable material such as rubber are fixed between upper and lower bushes 17 fixed to a frame 13.
The rod 16 is slidably fitted into the sleeve 18, and when no hydraulic pressure is applied within the sleeve 18, the sleeve 18 pushes the rod 16 with its own elasticity.
Tighten to fix the rod 16 so that it does not move,
When hydraulic pressure such as oil is applied to the inside of the sleeve 18, the sleeve 18 expands and a liquid film is formed between the sleeve 18 and the rod 16, allowing the rod 16 to slide freely.

In FIG. 2, reference numeral 21 denotes a hydraulic pressure source such as a hydraulic pump. This hydraulic pressure source 21 communicates with the locking device A via an electromagnetic switching valve 22, and the hydraulic pressure source 21 passes through electromagnetic switching valves 23 and 24. It communicates with both ends of the auxiliary cylinder 11 and the main cylinder 12.

Further, a flow rate control valve 25 consisting of a throttle valve and a check valve to prevent backflow of liquid from the auxiliary cylinder 11 to the switching valve 23 is provided in the middle of the flow path connecting the switching valve 23 and both ends of the auxiliary cylinder 11. to control the raising and lowering speed of the platform 14.

Further, a pressure relief valve 26 consisting of a throttle valve and a check valve that prevents liquid from flowing back in the direction of the switching valve is provided in the flow path connecting the upper chamber of the main cylinder 12 and the switching valve 24.
In FIG. 2, 27 is a liquid tank, and 28 is a workpiece fixed on the base plate 14.

In the case of the above embodiment, the switching valve 2 in the state shown in FIG.
When the solenoid on the left side of the switching valve 23 is energized by energizing the solenoid 2 to apply hydraulic pressure inside the sleeve 18 of the locking device A to release the lock, the solenoid on the left side of the switching valve 23 is energized, and the hydraulic pressure is applied to the lower chamber of the auxiliary cylinder 11 and The liquid returns to the tank 27 through the regulating valve 25, and the platform 14 rises at high speed.

As described above, when the workpiece 28 on the platform 14 that has risen at high speed touches or is about to contact the upper platform 15, a signal from a detector (not shown) is input to the control circuit and the switching valve is activated. The solenoid 22 is demagnetized and returns to the position shown in FIG. 14 is fixed.

As described above, the solenoid of the switching valve 24 is energized at the same time that the base plate 14 is fixed, and liquid pressure is applied to the upper chamber of the main cylinder 12, and the liquid in the lower chamber is returned to the tank. descends to a predetermined position and performs work such as pressurizing or cutting the workpiece 28.

When the work is finished, the solenoid of the switching valve 24 is demagnetized by the signal from the detector that detects this, hydraulic pressure is applied to the lower chamber of the main cylinder 12, and the liquid in the upper chamber is returned to the tank 27, so that the base plate 15 is Rise.

Next, at the same time as the solenoid of the switching valve 22 is energized, the solenoid on the right side of the switching valve 23 is energized, so that hydraulic pressure is applied inside the sleeve 18 and the locking device is released, and at the same time the auxiliary cylinder 1
Liquid pressure is applied to the upper chamber of 1, and the liquid in the lower chamber is transferred to tank 27.
The base plate 14 returns to its original position, and under this condition, the solenoids of the switching valves 22 and 23 are demagnetized, thus completing one process.

The embodiments shown in FIGS. 1 and 2 above show cases in which there are two rods 16 on the left and right, or a total of four rods 16 on the right and left, front and rear.

Moreover, in the case of FIG. 3, the rod 16 is also used as the piston rod of the auxiliary cylinder 11,
A locking device A is provided above the auxiliary cylinder 11, but the construction and operation of the hydraulic circuit and its control circuit are the same as in the embodiments shown in FIGS. 1 and 2.

〔effect〕

As described above, in this invention, one of the opposing base plates is supported by an auxiliary cylinder with a small diameter and long stroke, and the other base plate is supported by a main cylinder with a large diameter and short stroke. Since this system uses only the auxiliary cylinder to move one bed plate close to the other bed plate at high speed, there is no need to use the main cylinder in the first stage process as in the conventional method, and the main cylinder The stroke is based on actual pressure only.

In addition, in the first stage process, strokes corresponding to various thicknesses of the workpiece can be set arbitrarily by changing the detection position of the position detector and by detecting changes in the hydraulic load pressure. This is also a major feature not found in other toggle mechanisms.

In the second stage process after both base plates are brought close, the rod of one base plate driven by the auxiliary cylinder is locked by a hydraulic mechanical locking device and does not move, so only the main cylinder is operated. The other bed plate is brought close to perform the specified machining, but since the stroke during this machining is extremely short, the main cylinder only needs to be as short as possible, and the amount of liquid flowing into this main cylinder is Very few.

Therefore, the conventional head tank and large diameter pipe for sucking liquid into the main cylinder are unnecessary, the manufacturing cost of the main cylinder is reduced, and the entire machine becomes smaller and lighter.

Since the amount of hydraulic fluid flowing in and out of the main cylinder is small, the effect of compression of the hydraulic fluid is extremely small, and the shock that occurs when switching the switching valve is also reduced, and there is no longer a process where a large flow rate flows, so the resulting flow loss is reduced. This saves energy.

The base plate, which is moved by an auxiliary cylinder, uses a hydraulic mechanical locking device, and when it is locked, the hydraulic pressure is released, so there is no effect of internal leaks in the switching valves of the hydraulic circuit, and the base plate can be used for long periods of time. This has the effect of making it easier to maintain the position of the board.

[Brief explanation of drawings]

Fig. 1 is a partially longitudinal front view showing one embodiment of the device of the present invention, Fig. 2 is a circuit diagram of the same as above, Fig. 3 is a partially longitudinal front view showing another embodiment, and Fig. 4 is a conventional FIG. 2 is a partially longitudinal front view showing an example of the device. 11...Auxiliary cylinder, 12...Main cylinder, 1
4, 15... Base plate, A... Hydraulic mechanical locking device.

Claims (1)

[Claims] 1. In an opening/closing device such as a base plate that performs various molding or cutting by opening and closing a mold fixed to both base plates by moving both of the base plates with a fluid cylinder, one of the base plates can be moved by a fluid cylinder. A piston rod of a hydraulically operated auxiliary cylinder having a small diameter and long stroke is connected to the base plate, and a sleeve made of an elastically deformable material that tightens and locks the rod with its own elasticity is attached to the outer periphery of the piston rod.
If necessary, a hydraulic mechanical locking device consisting of a hydraulic circuit that releases the lock by applying hydraulic pressure between the rod and sleeve and expanding the sleeve is installed, and the other base plate is equipped with a large diameter and short stroke. An opening/closing device such as a base plate that connects the piston rod of a hydraulically operated main cylinder.