JPS5930498A - Hydraulically operated high speed continuous working press by pneumatic driving - Google Patents

Abstract

PURPOSE:To provide a titled working press having high versatility, by making use of the instantaneous force of compressed air and actuating the plunger piston of a booster at a high speed to apply inertia force, converting the inertia energy to pressure energy and using the same as the working pressure source for a hydraulic press. CONSTITUTION:An electromagnetic selector valve 26 is changed over to a descending side to evacuate quickly the air in the lower side of a piston 2 with an instantaneous evacuation valve 29, thereby moving the piston 2, a plunger 3, etc. at a high speed. Therefore the oil in a hydraulic cylinder 10 is forced out to flow into a press cylinder 11, by which a press ram 12 is lowered. The descending speed of the arm 12 is lower than the speed of the plunger 3 owing to a difference in the area between the plunger 3 and the cylinder 11, but the capacity is multiplied. Even if the capacity of an air cylinder 1 is small, the inertia force of the piston 2, etc. acts; therefore, inertia energy is converted to pressure energy in the cylinder 10 by a water hammer effect and the pressure waves is transmitted from the cylinder 10 to the cylinder 11, whereby the large capacity is generated in the ram 12.

Description

[Detailed Description of the Invention] The present invention uses compressed air as an operating source, and provides a hydraulic press with high-speed continuous operation performance similar to a mechanical press, while still having the characteristics of continuous control and stroke adjustment inherent in a hydraulic press. did,
This relates to a pneumatically driven hydraulic press that has the characteristics of both a mechanical press and a hydraulic press.

Conventionally, hydraulic presses have been devised to increase the working speed by increasing the low-pressure no-load speed using high-low pressure circuits, etc. to increase the overall work performance, but the net machining time is Since the pump capacity is determined by

Therefore, compared to mechanical presses that use the flywheel's inertial energy to reduce and store power,
Hydraulic presses require more power and require a higher cost for attached equipment such as pump units, making them less economical.

Conventionally, air hammers and air presses use compressed air to operate a hammer, etc. at high speed in an air cylinder, and use the inertia to perform impact processing.Air hammers and air presses use relatively low power (low air consumption) to produce large impact forces. Although it is a well-known technology that air cylinders are difficult to operate such as speed control, stroke adjustment, and positioning, it is very difficult to stop at a fixed position mid-stroke during press work, and it is difficult to operate the air cylinder in the middle of a stroke. Also, since the ram speed is very high, there is also the danger of impact loads.

The present invention has been made to eliminate these drawbacks.

The pneumatic/hydraulic booster method uses compressed air as the operating source to generate hydraulic pressure, and uses the instantaneous force of the compressed air to operate the booster's plunger and piston at high speed to provide inertial force and use this inertial energy. This is converted into pressure energy and used as the operating pressure source for a hydraulic press.

In Fig. 1, if the pushbuttons (53') and (53) are pressed, the solenoid (26) of the electromagnetic switching valve (26) and (27)
') and (27') are activated.

The electromagnetic switching valve (27) is connected to the booster hydraulic cylinder (
10) and the press cylinder (11) are connected.

The electromagnetic switching valve (26) switches to the downward side and the piston (26)
) is rapidly exhausted by the instantaneous exhaust valve (29), and the piston (2), plunger (3), etc. perform processing at high speed.

The oil in the hydraulic cylinder (10) is transferred to the plunger (3)
is pushed out and flows into the press cylinder (11),
Lower the press ram (12).

Due to the difference in area between the plunger (3) and the press cylinder (11), the descending speed of the press ram (12) is slower than that of the plunger (3), but the amount of force is increased, so the air cylinder (1) Although the force of the cylinder (
The pressure is converted into pressure energy within the cylinder (10) and propagated from the cylinder (10) to the press cylinder (11), making it possible to generate a large force in the press ram (12).

The piston (2) descends and the limit switch (50)
When the piston (
2) has inertia, so it continues to descend and pushes down the cushion ram (7).

The pressure oil in the cushion cylinder (8) is pumped through the throttle valve (4).
1), it is discharged to the pressure booster tank (22), and the inertial energy is absorbed by the cushioning effect of the hydraulic pressure.

When the piston (2) starts to rise, the pressure booster tank (22)
of pressure oil flows into the cushion cylinder (8) through the check valve (42) and the pressure oil flows into the cushion ram (7).
is pushed up to its original position in preparation for the next cushioning action.

As the plunger (3) rises, the pressure inside the press cylinder (11) is removed, so the press ram (
12) is also lifted up by the directly connected air cylinder (14) and returned.

The piston (2) rises and the upper limit switch (4)
9) is kicked, the electromagnetic switching valve (26) switches to the downward side.

The rising inertia of the piston (2) is the cushion ram (5
) and absorb it.

When the inertia disappears, the piston (2) descends again.

When the piston (2) descends, the upper cushion ram (5)
is returned to its original position by pressure oil from the pressure booster tank (22).

In this way, the press can continue its continuous operation of lowering and raising.

When finishing the press work, press the upper limit switch (49
) from the solenoid (26').
If the switching valve (26) is not activated, the switching valve (26) remains on the upward side, and the piston (2) stops with the upper cushion ram (5) pushed in.

Therefore, the press ram (12) also stops at the top of its stroke, ending the press cycle.

In order to prevent other dangers such as misfeeding of materials during press work, an electromagnetic switching valve (27) is provided for the purpose of stopping the descent of the press ram (12) midway.

During press operation, the solenoid (27') is normally
Although it is energized, while the press ram (12) is descending,
When the two-hand operation push buttons (53) (53') are released, the solenoid (26') (27') is de-energized and the solenoid switching valve (
27) closes both ports of the press cylinder (11), fixing the movement of the press ram (12) and releasing the pressure in the hydraulic cylinder (19) to bypass to the tank (25).

The electromagnetic switching valve (26) switches to the upward side, and the piston (2)
strokes independently of the movement of the press ram (12) and returns upward.

If the solenoid (27') is energized, the press ram (12
) will return to its upward position from the stop position.

In addition, the operation of the electromagnetic switching valves (26) and (27) is linked with the detection parts (51 and 52) of the optical safety device to operate as a press safety device.

The press stroke length is determined by the amount of oil fed to the booster, but the die height can be adjusted by changing the position of the upper limit stopper (21), so the stroke position can be changed freely.

Note that the stroke length can be adjusted by operating the electromagnetic switching valve (27) using the limit switches (47) and (48) to change the upper and lower limit positions of the press stroke.

To change the lower limit of the press stroke, the ram head (13) is lowered and the lower limit switch (48)
When kicked, the solenoid (27') is de-energized and the press ram (12) is stopped.

The booster side continues to operate, the piston (2) begins to rise, and when you kick the limit switch (50),
Energize solenoid (27') and press ram (12)
from that position.

Adjustment of the upper limit position of the press stroke is also possible using the upper limit.
The switch (47) de-energizes the solenoid (27') and fixes the press ram (12) while it is rising.

The booster side continues to rise, but when descending again, the piston (2) begins to descend and the limit switch (4)
9), the solenoid (27') is energized and the press ram (12) is lowered from its rest position.

Operate the air cylinder (14) using the electromagnetic switching valve (54) to raise the press ram (12) beyond the upper limit of the normal press stroke to obtain a press stroke that exceeds the discharge capacity of the booster. I can do things.

When the press ram (12) rises and kicks the upper limit switch (47), the solenoid (27') remains energized and the air cylinder (14)
Pull up the ram (12) until it hits the upper limit stopper (21).

When descending, press down the press ram (12) with the air cylinder (14) and press the upper limit switch (4).
7) When kicked, the solenoid (26') is energized,
Activate the booster and proceed to the normal press stroke.

When the press ram (12) descends and kicks the lower limit switch (48), the solenoids (26') (27'
) (54') is turned off, and the ascending process begins.

However, the press ram (12) is fixed in the lowered position by the solenoid switching valve (27), and the limit switch (
59) confirms that the booster side has risen, energizes the solenoid (27') and raises the press ram (12).

In this way, the length of the press stroke can be changed freely, so depending on the shape of the workpiece or the size of the mold, etc.
Machining that was difficult with conventional press machines with a fixed stroke length can now be performed with an appropriate working stroke.

During mold matching work, use solenoids (55') (27') (5
4'), the press ram (12) is pushed down by the air cylinder (14), and the descending speed is adjusted to be reduced by the throttle valve (56) to perform a very slow descent.

Inching lowering is performed by turning on and off the energization of the solenoid (27').

In addition, in the case of overload, which is inherent to hydraulic systems, the hydraulic pressure can be released from the relief valve (34), so since it does not necessarily work with a constant stroke, it can be used with friction presses, hammers, etc. As shown in the figure, press forming can be performed using free strokes, and forging work can also be performed using continuous blows.

When making continuous blows with a free stroke, use the cylinder (1
1) The pressure generated inside is detected by the pressure switch (44), the solenoid (26') is de-energized, and the switch is made to rise.

Excess pressure generated due to the inertial force is discharged from the relief valve (34) to the tank (25) to absorb the inertial force.

When the inertia disappears, the piston (2) rises and therefore the press ram (12) also rises.

When the piston (2) rises, the upper limit switch (49) energizes the solenoid (26'),
The piston (2) descends again and repeats the continuous impact processing.

During continuous impact processing, when the solenoid (9') is activated, the hydraulic pressure of the booster cylinder (10) is supplied to the press cylinder (11) through the check valve (38), so that the plunger Even if (3) returns,
The press ram (12) is fixed in that position and again
The plunger (3) is lowered, the hydraulic pressure increases, and the press ram (12) remains stationary until it presses.

Therefore, since the ram head (13) presses the workpiece intermittently while pressing the workpiece, the workpiece and the mold can be machined without being misaligned.

When the lower limit switch (48) is kicked, the solenoids (9') (26') are de-energized and the press ram (12) returns to its upward position.

The booster air cylinder (1) has a piston (2
) etc., since it only gives inertial energy to
Since a cylinder with a small amount of force is required, air consumption is extremely small, and it is economical with a small amount of power.

The device of the present invention combines the characteristics of a mechanical press with a hydraulic press by using the instantaneous force of compressed air through the configuration and operation described in detail above, and its mechanical characteristics are close to those of a friction press, with free stroke and stroke adjustment. In addition, it is possible to perform a constant continuous stroke, which is difficult to do with a friction press, and it can also be stopped instantaneously in the middle of a stroke, and has high work safety such as an overload prevention device with a safety valve, making it suitable for modern presses. In a friction press, the inertial energy of the flywheel does not match the working energy, and when the inertial energy is excessive, the machine itself may be damaged by threading off the boss of the flywheel, etc., or the mold may be damaged. This often results in damage to tools, etc., and operation requires intuition and skill, but with the press of the present invention, even if the inertial energy of the air booster and the working energy do not match, the cushion ram (5) and (7) Excess inertial energy is absorbed by the movement, and the relief valve (34) and pressure switch (44) can eliminate excess pressure and automatically operate the switching valve, so the inertial energy of the press is converted into working energy. Since it can be driven independently, it does not require any skill and can be easily operated.

It goes without saying that the press cylinder (11) can be driven by a hydraulic pump, but it is also possible to drive the press cylinder (11) by using a booster and a pump, or another large-capacity booster in place of the pump, as the hydraulic power source. The versatility has been increased, and a single press machine can perform operations such as crank press-like punching and cutting, friction press-like operations such as pressure forming, continuous blowing, shallow drawing, and hydraulic press-like operations. It can perform operations such as extrusion and deep drawing.

[Brief explanation of drawings]

FIG. 1 is an operating system diagram showing the configuration of the operating mechanism of the present invention. (1): Air cylinder, (2): Piston, (3)
(4): Plunger, (5) (7) Cushion ram, (11): Press cylinder, (12): Press
Ram, (13): Ram head, (14): Air cylinder for lifting, (19) (21): Stroke stopper, (22): Boosting tank (25) Oil tank,
(18): Auxiliary tank, (17): Bed, (9) (2
6) (27) (54) (55): Solenoid switching valve, (9')
(26') (27') (54') (55'): Solenoid, (28) (29): Instantaneous exhaust valve (30) (31) (
40) (41) (46) (56) (57) (59): Throttle valve, (47) (47') (48) (49) (50):
Limit switch, (36) (38) (39) (42)
(43) (58) (60): Check valve, (44): Pressure switch, (45): Pressure gauge, (51) (52): Optical safety device detection section, (53) (53'): Two-handed pushbutton (3
2) (33) (37): Pressure reducing valve, (34) (35): Relief valve ■

Claims (3)

[Claims] 1. The pneumatic/hydraulic booster system uses the instantaneous force of compressed air to cause the booster piston (2) to reciprocate at high speed, converting the resulting inertial energy into pressure energy and pumping the pressure oil into the booster cylinder. A hydraulic high-speed continuous operation press driven by pneumatic pressure that sends and discharges air from (10) to a press cylinder (11) to reciprocate a press ram (13). 2. At both ends of the booster air cylinder (1),
A pneumatically driven hydraulic high-speed continuous working press as claimed in claim 1, wherein hydraulic cushion rams (5) and (7) are provided to absorb inertial energy at both ends of the stroke. 3. An electromagnetic switching valve (27) is provided in the circuit from the booster cylinder (10) to the press cylinder (11) to stop the press ram (12) mid-stroke or adjust the stroke length. , a pneumatically driven hydraulic high-speed continuous operation press according to claim 1.