JPH0530560B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a mold mounting device for a press machine,
More specifically, the present invention relates to a mold mounting device that utilizes an overload safety device for a press machine.

(Prior Art) In press machines, it is necessary to accurately adjust die height. However, in a press machine, the frame elongates due to the working load, so the die height during press operation often takes a negative value compared to the static die height when the mold is installed.

Therefore, for example, if the previously produced semi-finished product is left between the upper mold and the lower mold even though the production die height has been resolved, the die height can be adjusted using the slide adjustment device, or the upper mold There is a problem in that it is not possible to move to production quickly because it requires troublesome adjustment work, such as the need to reverse the motor to return the slide to its normal position after clamping the slide.

(Problem to be Solved by the Invention) The problem to be solved by the present invention is to provide a mold mounting device for a press machine that can improve the workability of mold mounting by using an overload safety device. It is to provide.

(Means for solving the problem) Means for solving the problem in the present invention are as follows:
A connecting rod connected to the eccentric portion of the press drive shaft and driven up and down by the rotation of the press drive shaft, a slide attached to the connecting rod, and a hydraulic chamber formed inside the slide arranged so as to be movable up and down. , and a pressure receiving member that comes into contact with the connecting rod and receives press pressure, and the press pressure of the pressure receiving member is transmitted to the slide via pressurized oil of a predetermined pressure that is supplied to the hydraulic chamber, whereby the set pressure is set. In a press machine equipped with an overload safety device configured to prevent higher press pressure from being transmitted to the slide,
An oil tank provided adjacent to the hydraulic chamber, an air-driven pressurizing means connected to an oil pipe connecting the hydraulic chamber and the oil tank, and an air chamber of the pressurizing means connecting an air supply source. a normally open first on-off valve connected to an air pipe that sets the inside of the air chamber to a predetermined pressure; a normally closed second on-off valve connected to an oil pipe that connects the pump chamber of the pressurizing means and the oil tank; The present invention is characterized by comprising operating means for operating the first on-off valve and the second on-off valve in synchronization.

(Function) When performing normal press operation, the first on-off valve 8 is opened, the second on-off valve 12 is closed, and the pressurizing means 6 is operated to supply pressurized oil to the hydraulic chamber 4. Since the pressure oil is stopped by the check of the second on-off valve 12, it does not enter the oil tank 5.

When installing the mold, close the first on-off valve 8,
The second on-off valve 12 is opened. The pressurizing means 6 does not act, and therefore, the supply of pressure oil to the hydraulic chamber 4 stops, and at the same time, the second on-off valve 12 opens, so the hydraulic chamber 4 and the oil tank 5 have the same pressure. In this state, the mold is installed and the slide adjustment is performed.

The die height is larger when the mold is installed than when the press is running. This large die height corresponds to the thickness of the material remaining between the molds, so when the pressurizing means 6 is operated again after the mold is installed, the die height becomes small, and as a result, the dynamic die height (press load die height when applied)
is the regular die height of the mold.

(Embodiment) Fig. 1 is a configuration diagram showing an embodiment of the mold mounting device according to the present invention, in which a connecting rod is driven up and down by a press drive shaft (crankshaft) not shown. By attaching a slide 2 to the lower end of the press drive shaft 1, the slide 2 is moved up and down via the connecting rod 1 as the press drive shaft rotates. An upper mold (not shown) is fixed to the lower surface of the slide 2, and a lower mold (not shown) is also fixed to the upper surface of the bolster to press the plate material.

Although two slides are shown in the drawings, this embodiment is a two-point crankless press in which the press drive shaft is provided with two crank parts, and there is actually one slide.

Further, the lower surface of the connecting rod 1 is held in contact with the upper surface of a pressure receiving member 3 that receives press pressure transmitted from the drive shaft via the connecting rod 1, and the hydraulic pressure formed inside the slide 2 The pressure receiving member 3 is housed in the chamber 4 so as to be vertically movable. The hydraulic chamber 4 and an oil tank 5 provided adjacent to the hydraulic chamber 4
By connecting these through an air-driven pressurizing means 6, the pressure in the hydraulic chamber 4 is changed in accordance with the air pressure supplied to the air chamber 6a of the pressurizing means 6. This constitutes an overload safety device that prevents a press pressure greater than the pressure of the pressure oil from being transmitted to the slide 2.

6b is a piston housed in the air chamber 6a of the pressurizing means 6, 6c is a pump chamber, and 6d is an air switching valve.

Here, in the present invention, a normally open first on-off valve 8 that functions as a means for stopping the air supply source is provided in the middle of the air piping that sets the inside of the air chamber 6a to a predetermined pressure from the air supply source via the regulator valve 7. are connected. Furthermore, by connecting a manual on-off valve 9 to the air piping connecting the oil tank 5 and the air supply source, the internal pressure of the oil tank 5 (for example, 5
Kg/cm ² ) is kept constant. 10 is a pressure gauge. The manual on-off valve 9 is used to bleed air from the oil tank 5 during maintenance and inspection, and is intended for work safety.

Furthermore, a normally closed second on-off valve 12, which functions as means for lowering the set pressure of the hydraulic chamber 4, is connected between the oil pipe 11 leading from the pressurizing means 6 to the hydraulic chamber 4 and the oil tank 5. ing. By connecting the second on-off valve 12 and the first on-off valve 8 to the same operating means, for example, a switch, the pressurizing means 6 is stopped by the switch operation, and at the same time the oil pipe 11 is turned off. It is configured to be released into a tank 5. Note that 13 is a pressure gauge.

In the above configuration, in the illustrated state, the switch is not operated, so the first on-off valve 8 is open and the air pressure from the air supply source is pressurized at a predetermined pressure set by the regulator valve 7. The pressurizing means 6 supplies and maintains pressurized oil to the hydraulic chamber 4. However, since the second on-off valve 12 is closed, the oil pipe 11 is separated from the oil tank 5, and the pressure of the oil tank 5 is maintained at the set pressure. Therefore, in this state, the hydraulic chamber 4 shrinks and deforms only when a press pressure higher than the set pressure of the hydraulic chamber 4 is applied to prevent overload.

Next, when mounting a mold, the press is stopped at the top dead center, and a switch is operated to simultaneously operate the first on-off valve 8 and the second on-off valve 12.

Then, the supply of air pressure to the pressurizing means 6 is stopped and the pressurizing action by the pressurizing means 6 is stopped, and at the same time, the second on-off valve 12 is opened and the pressure oil in the oil pipe 11 is stopped. Since the oil is released into the oil tank 5, the pressure in the hydraulic chamber 4 decreases to the same pressure as the pressure in the oil tank 5, and as a result, the set pressure of the overload safety device decreases.

In this way, the die set is carried onto the bolster with the set pressure of the overload safety device reduced, and the slide is adjusted to a predetermined die height at the top dead center of the press. Then, the slide 2 is lowered to the bottom dead center by slow speed operation, etc., but the slide 2 comes into close contact with the upper mold from a stage before the bottom dead center by an amount corresponding to the difference between the static die height and the dynamic die height. Therefore, when the slide reaches the bottom dead center, the hydraulic chamber 4 is contracted and deformed, and the slide 2 is held in pressure contact with the upper mold by the reaction force.

Therefore, the upper mold can be clamped in this state, and the mold setting can be completed by continuing the operation to the top dead center. After that, the first on-off valve 8
When the second on-off valve 12 is reset by the operating means, the pressure in the hydraulic chamber 4 immediately rises to the set pressure value, so that production can be resumed.

(Effects of the Invention) The present invention is characterized in that the set pressure of pressure oil that transmits press pressure from the pressure-receiving member to the slide (the set pressure of the overload safety device) is the high pressure that responds during normal work and the low pressure that is used when installing the mold. Due to the structure that can be easily switched between the upper and lower dies, special die height adjustment is required even when previously produced semi-finished products or elastic spacers are sandwiched between the upper and lower dies. Therefore, after the mold is installed, production can proceed from the next stroke.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention. 1... Connecting rod, 2... Slide, 3... Pressure receiving member, 4... Hydraulic chamber, 5... Oil tank, 6... Pressurizing means, 8... First on-off valve, 9... Manual on-off valve ,1
2...Second on-off valve.

Claims (1)

[Scope of Claims] 1. A connecting rod connected to an eccentric portion of a press drive shaft and driven up and down by rotation of the press drive shaft, a slide attached to the connecting rod, and a hydraulic chamber formed inside the slide. a pressure-receiving member that is arranged to be movable up and down and receives press pressure by contacting the connecting rod, and press pressure of the pressure-receiving member is applied to the slide through pressurized oil at a predetermined pressure supplied to the hydraulic chamber; In a press machine equipped with an overload safety device configured to prevent press pressure higher than a set pressure from being transmitted to the slide by transmitting the pressure, the oil tank provided adjacent to the hydraulic chamber, the hydraulic chamber and the oil tank an air-driven pressurizing means connected to an oil pipe connecting the pressurizing means, and a normally open first air pipe connecting the air chamber of the pressurizing means to the air supply source and setting the inside of the air chamber to a predetermined pressure. an on-off valve, a normally closed second on-off valve connected to an oil pipe connecting the pump chamber of the pressurizing means and the oil tank, and an operation of synchronously operating the first on-off valve and the second on-off valve. A mold mounting device for a press machine, characterized by comprising means.