JP2598068Y2 - Piston rapid feed mechanism for manual hydraulic tools - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a manual hydraulic tool used for cutting and connecting electric wires in overhead wiring work and the like, and more particularly to a rapid feed mechanism for an output piston in the manual hydraulic tool.

[0002]

2. Description of the Related Art In a manual hydraulic tool used for cutting an electric wire and connecting using a terminal or a sleeve, a handle is manually swung, and hydraulic pressure by a pump action is applied to an output piston. Cutting and crimping work are performed between the mounted movable die and the fixed die mounted on the tool head, but minimize the no-load time until the electric wires etc. are clamped between both dies, and use light force. In order to increase the workability and reduce the labor by allowing high-pressure oil to be injected, a mechanism provided with a mechanism for rapidly feeding an output piston has been used.

As a manual hydraulic tool having such a rapid feed mechanism for a piston, there is, for example, a tool in which a pump plunger on an oil feed side is formed in two stages as shown in FIG. The piston rapid-forward mechanism of the manual hydraulic tool B includes a concentric two-stage plunger 42 fitted in a two-stage plunger chamber 41 formed of a large-diameter chamber and a small-diameter chamber formed in the tool body 40. By swinging the pressurizing handle 43, the operating oil is sucked from the attached oil tank 44 and supplied to the cylinder 45, and the output piston 46 housed in the cylinder 45 is moved. That is,
The large-diameter plunger portion 42a feeds a large amount of low-pressure oil to rapidly feed the output piston 46, and when a load is applied to the output piston 46, a high-pressure oil is applied by the small-diameter plunger portion 42b to perform high pressure and other operations such as crimping. It was made.

[0004]

However, in the hydraulic circuit provided in the tool body 40 of the manual hydraulic tool B, the hydraulic circuit is provided in parallel with the two-stage plunger 42.
A return valve 47 for forcibly returning the hydraulic oil in the cylinder 45 to the oil tank 44 after the operation, a push mechanism 48 thereof, and a high-pressure regulating valve 49 for returning high-pressure oil having a predetermined pressure or more to the oil tank 44 are provided. Further, a low-pressure regulating valve for returning low-pressure oil to the oil tank 44, some other suction valves and discharge valves are provided, and many cavities are drilled in the tool body 40 including the oil passage. That is, in order to secure the strength, it is necessary to sufficiently secure the thickness of the tool body 40. In order to reduce the size and weight of the hand-held tool, expensive materials such as titanium are not considered. And other problems.

In view of the above problems, an object of the present invention is to provide a hand-operated hydraulic tool that can be further reduced in size and weight without considering a special material or using a special material. Is what you do.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides an oil tank, a cylinder for accommodating an output piston at the tip of a tool body, and a swing of a pressure handle. In a manual hydraulic tool with a pump mechanism that sucks hydraulic oil by operation and pumps it to a cylinder,
The pump mechanism includes a plunger fitted in the large-diameter plunger chamber and formed concentrically with a small-diameter plunger chamber opening to the distal end side, and a pump mechanism fitted in the small-diameter plunger chamber and penetrating an oil passage through the shaft core. The tip is fixed to the tool body while communicating with the hydraulic circuit, and the tip has the same diameter from the tip to the base.
A piston of a hand-operated hydraulic tool, which comprises an inner piston formed , rapidly feeds the output piston with low-pressure hydraulic oil from the large-diameter plunger chamber, and pressurizes the output piston with high-pressure hydraulic oil from the small-diameter plunger chamber. This is a fast-forward mechanism.

[0007]

[Function] When the plunger moves upward, hydraulic oil from the oil tank is introduced into the large-diameter plunger chamber and the small-diameter plunger chamber, and when the plunger moves downward, the hydraulic oil in the large-diameter plunger chamber and the small-diameter plunger chamber is pushed out and the cylinder is pushed out. To feed the output piston rapidly. When fast-feeding is completed and load is applied to the output piston by multiple swinging operations of the pressurizing handle, a large amount of hydraulic oil from the large-diameter plunger chamber is returned to the oil tank through the low-pressure regulating valve, and the small-diameter plunger is returned. A small amount of hydraulic oil from the chamber is increased in pressure and becomes high pressure oil to press the output piston to perform work. The small-diameter plunger chamber is formed in a large-diameter plunger, and the inner piston fitted in the small-diameter plunger chamber is fixed, so that a large amount of low-pressure oil and a small amount of high-pressure oil can be obtained only by vertical movement of the plunger. The pump can be operated with good workability with a light force, and the volume occupied by the pump mechanism in the tool body can be reduced. Also, the degree of freedom for the arrangement of the high-pressure regulating valve can be increased, and the tool body can be downsized. Is possible.

[0008]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a manual hydraulic tool according to the present invention. 1 is a side sectional view of a main part of the manual hydraulic tool of the present invention, FIG. 2 is a plan cross-sectional view of a main part of the tool of FIG.
3A and 3B are front cross-sectional views of a main part of the tool in FIG. 1, wherein FIG. 3A shows a plunger in a down state, and FIG. 3B shows a plunger in an up state.

As shown in FIG. 1, a fixed handle 3 serving also as a storage section for an oil tank 2 is provided at the base end of the tool body 1.
A large-diameter plunger chamber 4 is formed on the upper part, and a plunger 5 is fitted therein. A concentric small-diameter plunger chamber 6 is formed inside the plunger 5 and a distal end to a proximal end are formed.
The inner piston 7 formed to have the same diameter up to the portion is fitted. The inner piston 7 has an oil passage 8 penetrating the shaft core, a lower end fixed to the tool body 1 by screwing, and the oil passage 8 is provided inside the tool body 1 as described later. It is connected to the circuit. The upper part of the plunger 5 is locked by a locking shaft 11 of a pressure handle 10 pivotally supported by a pivot 9 of an upper column 1a of the tool body 1. By the swing operation of the pressure handle 10, The plunger 5
The pump mechanism can be repeatedly moved up and down.

Further, a return mechanism for returning hydraulic oil in the hydraulic circuit to the oil tank 2 is arranged in parallel with the plunger 5. That is, the release pin 13 urged upward by the spring 12 is turned down by rotating the pressurizing handle 10, whereby the return valve 15 urged by the spring 14 is pressed.
Is pushed open so that the hydraulic circuit can communicate with the oil tank 2. A cylinder 16 is formed at the tip of the tool body 1, and a spring 17 is provided inside the cylinder 16.
The piston 18 urged toward the base end side is accommodated in the housing 18, and a movable die 19 is detachably attached to the distal end of the piston 18.

A hydraulic circuit provided inside the tool body 1 will be described with reference to FIGS. An oil strainer 20 is attached to a suction port from the oil tank 2, a suction oil passage 21 following the oil strainer 20 branches, and one branch passage communicates with a low-pressure oil passage 23 via a suction valve 22. The low-pressure oil passage 23 communicates with the large-diameter plunger chamber 4 via the low-pressure oil passage 23a. The low-pressure oil passage 23 is opened to the bottom of the cylinder 16 via a discharge valve 24 and communicates with the oil tank 2 via a low-pressure regulating valve 25. It can be returned to 2.

Another branch from the suction oil passage 21 communicates with a high-pressure oil passage 27 via a suction valve 26, and also via an oil passage 8 in the inner piston 7 at an upper portion of the inner piston 7. It communicates with the small diameter plunger chamber 6. The high-pressure oil passage 27 is connected to the cylinder 1 via a check valve 28.
6 Opened at the bottom. Further, a high pressure regulating valve 2 is provided below the plunger 5 so as to be orthogonal to the front-rear direction of the tool body 1.
9 and a high-pressure oil passage 30 communicating with the bottom of the cylinder 16
To return high-pressure oil of a predetermined pressure or more to the oil tank 2 via the return oil passage 31. Further, a high-pressure oil passage 32 is provided between the bottom of the cylinder 16 and the return valve 15 of the return mechanism, and the hydraulic oil in the hydraulic circuit is returned to the oil tank via the return oil passage 33 (FIG. 1). It can be forcibly returned to 2.

In the manual hydraulic tool A according to the present invention thus configured, the plunger 5 moves up and down by swinging the pressurizing handle 10 while holding the fixed handle 3. That is, the plunger 5 in the state of FIG.
When the plunger 5 is moved upward, the large-diameter plunger chamber 4 formed below the plunger 5 and the small-diameter plunger chamber 6 formed above the inner piston 7 have a negative pressure, and one suction valve 22 is opened. Then, the hydraulic oil is sucked from the oil tank 2 into the large-diameter plunger chamber 4 via the oil strainer 20, the suction oil passage 21, and the low-pressure oil passage 23, and the other suction valve 26 is opened to open the high-pressure oil passage 27. The working oil is sucked into the small-diameter plunger chamber 6 via the small-diameter plunger chamber 6.

Then, when the plunger 5 moves downward, the pressure of the sucked hydraulic oil is increased, and the discharge valve 24 and the discharge valve 28 are pushed open to be fed into the cylinder 16 respectively. Since a large amount of hydraulic oil in the large-diameter plunger chamber 4 is fed, the piston 18 in the cylinder 16 is rapidly fed. When the movable die 19 comes into contact with the workpiece to apply a load, the hydraulic oil in the hydraulic circuit communicating with the cylinder 16 is increased in pressure, and when a predetermined low pressure is reached, a large amount of hydraulic oil from the large diameter plunger chamber 4 is released. The hydraulic oil is returned to the oil tank 2 by opening the low pressure regulating valve 25. On the other hand, the hydraulic oil from the small-diameter plunger chamber 6 continues to increase in pressure and pushes the piston 18 to reach a predetermined high pressure.
9 and open the oil tank 2 via the return oil passage 31.
The hydraulic pressure in the hydraulic circuit on the cylinder 16 side is kept constant, and when the operation of pressing the movable die 19 to perform work such as crimping is completed, the pressing handle 10
When the release pin 13 of the return valve mechanism is pushed down, the return valve 15 is opened, and the hydraulic oil on the cylinder 16 side flows from the return oil passage 33 through the high pressure passage 32 and the return valve 15 to the oil. Returned to tank 2.

In this embodiment, a small-diameter plunger chamber 6 is formed inside a plunger 5, and an inner piston 7 having one end fixed to the tool body 1 is accommodated therein.
Like the step plunger, the plunger 5 moves up and down to generate a large amount of low-pressure oil to rapidly feed the piston 18, and to easily push the piston 18 with a small amount of high-pressure oil by a light force. Therefore, in this pump mechanism, the volume of the plunger 5 occupied in the tool body 1, that is, the volume of the large-diameter plunger chamber 4, is about the volume of the large-diameter portion of the conventional two-stage plunger. The high-pressure regulating valve 29 that has been disposed in parallel with the plunger and the return valve mechanism can be disposed below the plunger 5,
The front-rear dimension of the tool body 1 can be reduced, the extension dimension of the hydraulic circuit can be reduced, and the hand-held hydraulic tool can be reduced in size and weight and workability can be improved.

[0016]

As is apparent from the above description, according to the present invention, a small-diameter plunger chamber is provided in a plunger which moves up and down by engaging with a pressure handle so that an inner piston is fitted. The volume occupied by the pump mechanism in the tool body is greatly reduced as compared with the conventional pump mechanism. For example, the degree of freedom in the arrangement of the regulating valve, for example, the high-pressure regulating valve can be arranged below the pump mechanism, increases the tool body. This makes it possible to reduce the size and weight of the device and to improve the workability by shortening the hydraulic circuit.

[Brief description of the drawings]

FIG. 1 is a side sectional view of a main part of the manual hydraulic tool according to the present invention.

FIG. 2 is a plan sectional view of a main part of the manual hydraulic tool shown in FIG. 1;

FIG. 3 is a front sectional view of a main part of the manual hydraulic tool of FIG. 1;
(A) is a figure which shows the downward movement state of a plunger, (b) is a figure which shows the plunger upward movement state.

FIG. 4 is a side sectional view of a main part of a conventional manual hydraulic tool.

[Explanation of symbols]

 A Hand-operated hydraulic tool 1 Tool body 2 Oil tank 3 Fixed handle 4 Large-diameter plunger chamber 5 Plunger 6 Small-diameter plunger chamber 7 Inner piston 8 Oil passage 10 Pressurizing handle 13 Release pin 15 Return valve 16 Cylinder 17 Spring 18 Piston 21 Suction oil Routes 22, 26, suction valve 23 low-pressure oil passage 24, 28 discharge valve 25 low-pressure regulating valve 27, 30, 32 high-pressure oil passage 29 high-pressure regulating valve

Claims (1)

(57) [Scope of request for utility model registration] An oil tank is provided, a cylinder for accommodating an output piston is formed at the tip of a tool body, and a pump mechanism for sucking hydraulic oil by a swing operation of a pressurizing handle and for pumping the hydraulic oil to the cylinder is provided. In the manual hydraulic tool provided,
The pump mechanism includes a plunger fitted in the large-diameter plunger chamber and formed concentrically with a small-diameter plunger chamber opening to the distal end side, and a pump mechanism fitted in the small-diameter plunger chamber and penetrating an oil passage through the shaft core. The tip is fixed to the tool body while communicating with the hydraulic circuit, and the tip has the same diameter from the tip to the base.
A manual hydraulic system, comprising: an inner piston formed; rapidly feeding the output piston with low-pressure hydraulic oil from the large-diameter plunger chamber; and pressurizing the output piston with high-pressure hydraulic oil from the small-diameter plunger chamber. Rapid traverse mechanism for piston type tools.