JPH09168915A - Hydraulic actuation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To miniaturize a jaw part to lighten weight. SOLUTION: A cylinder chamber 10, wherein both ends in an axis direction are sealed by vertical and front end walls 11 and 16, is provided in a casing main body 4. A piston 14 is slidably fitted in the cylinder chamber 10. The tip of a piston rod 15 is made to penetrate a front end wall 16, to be protruded outside, to fit a knife 17 to the tip. A receiving metal fitting 29 is fitted, opposite to the knife 17, to the tip of a jaw part 28 extending forward from the front end wall 16. A hydraulic pump device 9 and an oil tank 5 are provided on the rear of the vertical wall 11. A rubber-made bag-like oil leveller 6 is fitted in the oil tank 5. The oil 8 of the whole stroke part of a piston 14 is housed in the oil leveller 6. A return spring 21 is arranged between the front end wall 16 and the piston 14. Air holes 22 and 5a, for releasing air, are provided on the front end wall 16 and the oil tank 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic operating device in which a tool such as a cutter is mounted on the tip of a piston rod to perform cutting work by hydraulic drive, and in particular, the device structure on the tool side is downsized to reduce the weight. The present invention relates to a hydraulic actuator that can achieve the above.

[0002]

2. Description of the Related Art Conventionally, as a hydraulic actuator for operating a piston rod by hydraulic drive, for example, Japanese Utility Model Application No.
As shown in Japanese Patent No. 133697, a piston and a rod are disposed reciprocally in a cylinder chamber, a return spring is disposed in a cylinder chamber on the front end wall side via the piston, and a rear end is disposed via a piston. There is known a wall-side cylinder chamber in which oil in an oil tank is pressurized and supplied by a hydraulic pump device.

In such a hydraulic operating device, a tool such as a cutter, a punch, a bending arm, or the like is mounted on the tip of the piston rod according to the purpose of the work. By supplying high-pressure oil from the device into the cylinder chamber on the rear end wall side, the piston rod moves forward to perform cutting work, drilling, bending, etc., and then stop the hydraulic pump device, The piston rod is retracted by the return spring.

[0004]

By the way, in the conventional hydraulic actuator described above, a fixed tool is arranged on the tip side of the tool mounted on the tip of the piston rod, and the fixed tool is attached from the lower end of the cylinder chamber to the tip. It is supported by a jaw extending to the side. In addition, the oil in the cylinder chamber on the front end wall side is introduced into the pressure regulation chamber formed in the jaw,
The air bag arranged in the pressure adjusting chamber is inflated and contracted in accordance with the oil pressure in the pressure adjusting chamber to adjust the pressure.

In such a structure in which the pressure regulating chamber is formed in the tip side jaw, the oil in the cylinder chamber on the front end wall side may leak to the outside from the sealed portion of the pressure regulating chamber when the piston reciprocates. Further, since the pressure adjusting chamber is formed in the heaviest jaw, the jaw becomes large, and it is difficult to reduce the size and weight of the hydraulic actuator.

The present invention has been made in view of the above points, and an object of the present invention is to provide a hydraulic actuating device which is free from the risk of oil leakage and which can reduce the weight of the device.

[0007]

In order to achieve the above object, the present invention is directed to a cylinder chamber, a piston reciprocally disposed in the cylinder chamber, a front end wall of the cylinder chamber, and a tool at the tip. Is mounted, a return spring disposed in the cylinder chamber on the front end wall side, and a return spring disposed on the side opposite to the cylinder chamber via the rear end wall of the cylinder chamber to pressurize the oil in the oil tank. A hydraulic actuating device comprising a hydraulic pump device for supplying into the cylinder chamber on the end wall side, wherein a flexible oil leveler accommodating oil for the entire stroke of the piston is arranged in the oil tank. To do. Thus, it is not necessary to provide a pressure adjusting chamber in the heaviest jaw, and the jaw can be downsized for weight reduction. Also, since there is no oil in the cylinder chamber on the front end wall side,
There is no risk of oil leakage.

[0008]

Embodiments of the present invention will be described below with reference to the drawings.

1 to 3 show an example of a hydraulic actuating device according to the present invention. In the drawings, reference numeral 1 is an electric motor assembled to a pistol-type handle 2. Is attached to the rear end of the casing body 4 with the motor shaft 3 inserted in the casing body 4.

Inside the casing body 4, as shown in FIGS. 1 and 2, an oil tank 5 having an air hole 5a for opening to the atmosphere is provided. A bag-shaped oil leveler 6 made of a flexible material is provided, and the oil leveler 6 is fixed to an opening edge of the oil tank 5 via a stop ring 7. Then, the oil 8 for the entire stroke of the piston 14 described later is accommodated in the oil leveler 6.

A hydraulic pump device 9 is provided at the rear of the inside of the casing body 4, and a cylinder chamber 10 is formed substantially in the center of the casing body 4. The cylinder chamber 10 and the oil tank 5 are separated from each other. It is partitioned by the vertical wall 11. A hydraulic chamber 12 is provided on the vertical wall 11 side of the cylinder chamber 10, and pressure oil generated by the hydraulic pump device 9 passes through an oil discharge hole 13 provided through the vertical wall 11. And is sent to the hydraulic chamber 12.

A piston 14 is arranged in the cylinder chamber 10 so as to be slidable in the axial direction.
A piston rod 15 is integrally provided at the center of the tip surface of the. The piston rod 15 penetrates the front end wall 16 of the casing body 4 that seals the cylinder chamber 10 and projects to the outside of the casing body 4.
A knife 17 for the cutter is detachably attached.

A hole 18 is formed in the center of the piston rod 15, and a return valve 19 is provided in the hole 18 so as to reciprocate. When the piston 14 is moved forward by a predetermined distance, it abuts on the valve plate 20 attached to the piston 14 and the return valve 19 floats up, and the pressure oil passes through the central through hole of the vertical wall 11 and the oil tank 5 It is supposed to be transferred to the side.

A return spring 21 is interposed between the front end surface of the piston 14 and the front end wall 16. The return spring 2
The urging force of 1 causes the piston to move backward. The inside of the cylinder chamber 10 on the side of the front end wall 16 via the piston 14 is opened to the atmosphere via the air hole 22 so that negative pressure is not generated when the piston 14 moves backward.

On the other hand, the hydraulic pump device 9 is provided with a plurality of pump cylinders 24 (only one is shown in the drawing) arranged at equal intervals in the circumferential direction on the outer peripheral portion of the cam portion 23 at the tip of the motor shaft 3. A piston 25 that reciprocates due to the rotational movement of the cam portion 23 is inserted in the pump cylinder 24. An oil suction groove 26 for supplying the oil 8 to the pump cylinder 24 is provided at the end of the pump cylinder 24.
Is provided, and an oil discharge hole 13 for discharging pressure oil is provided at the other end. An opening / closing valve 27 that opens / closes the oil discharge hole 13 is provided at the discharge side end of the pump cylinder 24.

A jaw portion 28 extending parallel to the piston rod 15 is provided at the lower end of the front end wall 16, and a receiving metal fitting 29 for cutting a material (not shown) in cooperation with the knife 17 is provided at the tip thereof. However, detachable and replaceable knife 1
7 are arranged opposite to each other.

Next, the operation of this embodiment will be described.

When the electric motor 1 is started from the initial state shown in FIG. 2, the cam portion 23 at the tip of the motor shaft 3 rotates, which causes the piston 25 to reciprocate. Then, the oil 8 in the oil leveler 6 moves from the oil suction groove 26 to the pump cylinder 2
4 is sucked into the inside of the hydraulic pressure chamber 4 and pressurized there, and then is supplied into the hydraulic chamber 12 through the oil discharge hole 13. As a result, the piston 14 and the piston rod 15 advance, and the material is cut between the knife 17 and the receiving fitting 29.

FIG. 1 shows the state at the time of this cutting.
Most of the oil 8 in the oil leveler 6 is supplied into the hydraulic chamber 12, and the oil leveler 6 is in a contracted state.

By the way, when the oil leveler 6 contracts,
Although the voids in the oil tank 5 increase, the inside of the oil tank 5 is open to the atmosphere through the air holes 5a, so that there is no problem that the inside of the oil tank 5 becomes a negative pressure and hinders the contraction of the oil leveler 6.

When the piston rod 15 advances and the material is cut, the return valve 19 abuts on the valve plate 20 attached to the piston 14 and floats up, and the pressure oil in the hydraulic chamber 12 becomes an oil leveler in the oil tank 5. 6 is returned to the initial state shown in FIG.

At this time, the volume inside the cylinder chamber 10 on the side of the front end wall 16 through the piston 14 is
However, since this portion is open to the atmosphere through the air hole 22, there is no problem that negative pressure is generated and the backward movement of the piston 14 is obstructed.

In this way, the oil tank 5 is provided behind the cylinder chamber 10.
Since the oil leveler 6 that accommodates the oil 8 for the entire stroke of the piston 14 is disposed in the oil tank 5, the jaw portion 28 can be made compact and lightweight.

Further, since oil is not injected into the interior of the cylinder chamber 10 on the side of the front end wall 16 via the piston 14,
When the piston 14 operates, there is no risk of oil leaking to the outside through the piston rod 15.

In the above embodiment, the case where the knife 17 is attached to the tip of the piston rod 15 and used as a material cutting device has been described. However, a punch is attached to the tip of the piston rod 15 to form a hole punching device. It can be used, or can be used as a material vendor by attaching a pressing die to the tip of the piston rod 15.

[0026]

As described above, according to the present invention, the flexible oil leveler is arranged in the oil tank, and the inside of the oil tank and the cylinder chamber on the front end wall side are opened to the atmosphere. It is possible to reduce the weight of the heavy jaw by downsizing it. Further, since the cylinder chamber on the front end wall side is not filled with oil, there is no problem that oil leaks to the outside through the piston rod during piston operation.

[Brief description of the drawings]

FIG. 1 is a cross-sectional configuration diagram of essential parts of a hydraulic operating device according to an embodiment of the present invention.

FIG. 2 is a view corresponding to FIG. 1 showing a state in which a piston is retracted.

3 is an overall configuration diagram of the hydraulic actuator of FIG.

[Explanation of symbols]

 1 Electric Motor 3 Motor Shaft 4 Casing Main Body 5 Oil Tank 5a, 22 Air Hole 6 Oil Leveler 8 Oil 9 Hydraulic Pump Device 10 Cylinder Chamber 11 Vertical Wall 12 Hydraulic Chamber 14 Piston 15 Piston Rod 16 Front End Wall 17 Knife 19 Return Valve 21 Return Spring 23 Cam part 28 Chin part 29 Receiving bracket

Claims (3)

[Claims] 1. A cylinder chamber, a piston reciprocally arranged in the cylinder chamber, a piston rod which penetrates a front end wall of the cylinder chamber and has a tool attached to a tip thereof, and a cylinder on the front end wall side. A return spring arranged inside the chamber and a hydraulic pump device arranged on the side opposite to the cylinder chamber through the rear end wall of the cylinder chamber to pressurize the oil in the oil tank and supply the oil into the cylinder chamber on the rear end wall side. A hydraulic operating device provided with a flexible oil leveler for accommodating the oil for the entire stroke of the piston in the oil tank. 2. The hydraulically actuated device according to claim 1, wherein the cylinder chamber on the front end wall side is open to the atmosphere. 3. The hydraulically actuated device according to claim 1, wherein the oil leveler outer wall side in the oil tank is open to the atmosphere.