JPS632312Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention is designed to control the hydraulic pressure of a hydraulic tool such as a compressor used for operations such as inserting an electric wire into a metal sleeve and compressing it together with the sleeve to connect the electric wire. This relates to a device that automatically releases when pressure is established.

Conventionally, as shown in FIG. 5, a hydraulic pump P that can send oil to a hydraulic tool T via a hydraulic hose 1 and the air pressure of an air balloon B control the rotation of an engine E for driving the hydraulic pump via an air tube 2. a hydraulic piston 5 which is retracted in the cylinder by a predetermined hydraulic pressure;
It is known that an automatic hydraulic release device is attached, which comprises an air valve 6 disposed coaxially with the rear of the hydraulic piston 5 and pushed by the hydraulic piston 5 to release the air pressure inside the air tube 2. ing. This system automatically releases the air pressure when the predetermined pressure required for the work is obtained, thereby decelerating the rotation of the engine E, disengaging the clutch 4, stopping the pump P, and releasing the hydraulic pressure. be. However, in this type, the hydraulic piston 5 and the air valve 6 are installed continuously on the same axis, so it is difficult to adjust the specified pressure, and the air valve 6 is directly connected to the hydraulic piston 5. Since the pressure is interlocked with each other, the release operation of the air pressure becomes gradual, resulting in variations in the operating pressure, which has drawbacks such as it is very difficult to set a specified pressure.

The present invention was devised to eliminate the above-mentioned drawbacks of automatic hydraulic release devices in conventional hydraulic tools, and includes a curved leaf spring interposed between a hydraulic piston and an air valve. The air valve is characterized by making the operation of the air valve instantaneous by utilizing the change in the pressing direction caused by the change in the rotation position, ensuring reliable operation at the specified pressure, and making it easy to adjust the specified pressure. .

An example of implementing the present invention will be described with reference to FIGS. 1 to 4. This hydraulic tool, like the conventional hydraulic tool shown in FIG. 5, applies air pressure to the control device 3 through the air tube 2 using the air balloon B, and operates the diaphragm to open the throttle of the engine E and operate the centrifugal clutch 4. The pump P is rotated to apply hydraulic pressure to the tool T via the hydraulic hose 1.

In the present invention, the hydraulic cylinder 7 containing the hydraulic piston 5 is connected to the hydraulic hose 1 at one end side.
The piston rod 5a of the piston 5 freely slides through the same end wall and projects to the outside. The piston 5 is normally urged in the piston rod protruding direction by an attached spring 8, and is configured to retreat in the pushing direction when the hydraulic pressure exceeds the elastic force of the spring 8. The specified oil pressure at which the piston 5 retreats can be appropriately selected by adjusting the adjustment valve 9 forward or backward.

The air cylinder 10 is disposed opposite to the hydraulic cylinder 7 at a distance in the direction in which the piston rod 5a of the hydraulic piston 5 projects. One end of this air cylinder 10 communicates with the air tube 2, and the side portion thereof is opened to the outside via the air valve 6. A valve stem 6a of the air valve 6 freely slides through an end wall facing the hydraulic cylinder 7 and projects to the outside. This valve rod 6a has a different axis from that of the hydraulic piston rod 5a, and there is a gap between both ends. The air valve 6 normally closes the air passage to the outside by an attached spring 11, and is pressed in a direction in which the valve stem 6a protrudes.

A U-shaped plate spring 12 is disposed between the ends of the piston rod 5a and the valve stem 6a, with both ends supported by support plates 13 and 14, respectively, so as to be rotatable. Both support plates 13 and 14 swing and support the valve stem 6.
a, the tip, and the tip of the piston rod 5a, extending from their sides in a direction perpendicular to them and in parallel with each other so as to be in contact with the tip of the piston rod 5a. One support plate 14 is always pushed into the piston rod 5a and is urged to follow the movement thereof, and extends longer than the other support plate 13, with its tip bent in the direction of the other support plate 13. are doing. As shown in FIG. 1, this bent tip is normally positioned closer to the air cylinder 10 than the extension line A of the support plate 13. In this state, the tip of the support plate 13 is slightly curved inward, that is, in the direction of the support plate 14, due to the restoring force of the leaf spring 12.

When operating the hydraulic tool configured as described above, the air balloon B is repeatedly deflated to apply pressure to the control device 3, thereby increasing the rotation of the engine E, and the hydraulic pump P is operated via the hydraulic hose 1. Apply hydraulic pressure to tool T. When the tool T performs a compression operation and the oil pressure is increased, the oil pressure causes the piston 5 to gradually retreat against the spring 8, and the support plate 14 follows the piston rod 5a. gradually curves, the leaf spring 12 also pivots, and the tips of the other support plates 13 gradually return to their straight state. The oil pressure is further increased and when it reaches around the specified oil pressure required for the work, the third
As shown in the figure, the support plate 13 is almost linear, the tip of the support plate 14 is on the extension line A of the support plate 13, and the distance between the tips of both the support plates 13 and 14 is the shortest, and the leaf spring 12 is in the most compressed state with an expanding force not in either direction of the piston rod 5a or valve stem 6a, but in the direction of opposing ends of both support plates. This point is what is called a consideration point for the leaf spring 12. Therefore, when the piston rod 5a retreats and the outside of the leaf spring 12 is slightly tilted toward the piston rod 5a from this point, the end of the leaf spring 12 on the support plate 13 side presses the support plate 13 toward the valve stem 6a. Then, the valve rod 6a is pushed into the cylinder 10 against the spring 11. Then, the valve 6 opens, the air tube 2 communicates with the outside air, and the air pressure is released, so the throttle of the engine E returns and the spring E becomes idling, the centrifugal clutch 4 is disengaged, the oil pressure decreases, and the tool returns to its original position. During this time, the hydraulic piston 5 is also restored, and when it is completely restored, the leaf spring 12 crosses the point and releases the air valve, instantly closing the air passage.

Although the support plates 13 and 14 are made separate from the piston rod 5a and the valve rod 6a here, the plate spring 12 can be connected directly to the piston rod 5a and the valve rod 6a by modifying them. . In short, the leaf spring 12 may be substantially connected to the piston rod 5a and the valve rod 6a.

As described above, the present invention does not directly connect the hydraulic piston 5 and the air valve 6, but instead interposes a curved leaf spring between them, and rotates this leaf spring as the hydraulic piston moves back and forth, thereby adjusting its inclination angle. Because the change causes a so-called snap action, which opens and closes the air valve, it is easy to adjust the specified oil pressure, and the air valve opens and closes more accurately with the specified oil pressure.
Reliable instantaneous operation. Furthermore, even if the hydraulic pressure reaches a specified value and this release device operates, the hydraulic pressure decreases, and the hydraulic piston 5 begins to move forward, the air valve 6 is not directly connected, so it does not close immediately and the hydraulic piston Since the circuit is closed when the air pressure is completely restored, it is possible to prevent accidents caused by incomplete release of air pressure.

[Brief explanation of drawings]

1 to 4 are front views showing an example of the implementation of the present invention according to the order of operation, and FIG. 5 is a front view showing a conventional example. 1...Hydraulic hose, 2...Air tube, 3...
...Control device, 4...Centrifugal clutch, 5...Hydraulic piston, 5a...Piston rod, 6...Pneumatic valve, 6
a...Valve stem, 7...Hydraulic cylinder, 8...Spring,
9...adjustment valve, 10...air cylinder, 11...
Spring, 12... leaf spring, 13, 14... support plate,
A... Extension line, B... Air balloon, E... Engine, P... Hydraulic pump, T... Tool.

Claims (1)

[Scope of utility model registration request] A hydraulic pump that operates tools using hydraulic pressure, an engine that drives this hydraulic pump, a control device that controls the rotation of the hydraulic pump drive engine using air pressure from an air pressure generator, and a control device that senses a predetermined oil pressure from the hydraulic pump to operate. A hydraulic tool comprising a hydraulic piston and a hydraulic release device constituted by an air valve that releases air pressure in response to the hydraulic piston, wherein the hydraulic piston and the air valve are arranged to face each other, and the hydraulic piston and the air valve are arranged opposite to each other. The leaf springs are connected to each end of a curved leaf spring, and the leaf springs store energy in conjunction with the operation of the hydraulic piston, and instantaneously release the force in the opposite direction at the trial point, making it possible to open and close the air valve. A hydraulic release device for a hydraulic tool, characterized in that: