JPH0646876U - Piston rapid feed mechanism for manual hydraulic tools - Google Patents

Abstract

(57) [Abstract] [Purpose] An oil tank is attached to the base end of the tool body that has a hydraulic circuit equipped with a low pressure control valve and a high pressure control valve.
A cylinder for accommodating an output piston is formed at the tip of the tool body, and a manual hydraulic pressure provided with a pump mechanism for sucking the working oil in the oil tank by the swinging operation of the pressurizing handle and pumping it to the cylinder. Aim to reduce the size and weight of the tool. [Structure] The pump mechanism is fitted into a large-diameter plunger chamber formed in the tool body, and a tip portion is fixed to the tool body while being fitted in a small-diameter plunger chamber formed inside the plunger. This small-diameter plunger has an oil passage extending through the shaft core to communicate with the hydraulic circuit.The large-diameter plunger chamber uses a large amount of low-pressure hydraulic oil to rapidly feed the output piston, and the small-diameter plunger. The output piston can be pressurized by the high pressure hydraulic oil in the chamber.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a manual hydraulic tool used for cutting and connecting processing of electric wires in overhead wire construction, etc., and more particularly to a rapid feed mechanism for an output piston in the manual hydraulic tool.

[0002]

[Prior art]

 In the case of a manual hydraulic tool that is used for cutting electric wires and connecting with terminals and sleeves, etc., the handle is oscillated manually, and the movable die attached to the output piston is operated by the hydraulic pressure of the pump action. This is for cutting and crimping work with a fixed die attached to the tool head, but it minimizes the no-load time until an electric wire is clamped between both dies, and it also uses high pressure oil with a light force. In order to enable press-fitting and improve workability and reduce labor, one that has a mechanism for fast-forwarding the output piston is being used.

As a manual hydraulic tool having such a rapid feed mechanism for a piston, there is, for example, one in which a pump plunger on the oil feed side is formed in two stages as shown in FIG. The piston rapid feed mechanism of the manual hydraulic tool B is provided with 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 attached pressure handle 43, the working 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, a large amount of low pressure oil is sent by the large diameter plunger part 42a to fast-forward the output piston 46, and when a load is generated on the output piston 46, high pressure is applied by the high pressure oil by the small diameter plunger part 42b to perform work such as pressing. It is made possible to do.

[0004]

[Problems to be solved by the device]

 However, in the hydraulic circuit provided in the tool body 40 of the manual hydraulic tool B, the hydraulic oil in the cylinder 45 is forced to the oil tank 44 after the work in parallel with the two-stage plunger 42. Is provided with a return valve 47 for returning it to the oil tank 44, a high pressure regulating valve 49 for returning high pressure oil of a predetermined pressure or higher to the oil tank 44, and a low pressure regulating valve for returning low pressure oil to the oil tank 44. , Several other intake valves and discharge valves are provided, and many cavity parts are to be bored in the tool body 40 including the oil passage, and in order to secure the strength, It is necessary to secure a sufficient wall thickness in the tool body 40, and in order to reduce the size and weight required for a hand-held tool, there was a problem that expensive materials such as titanium had to be considered.

In view of the above problems, the present invention provides a manual hydraulic tool that does not consider a special material, or uses a special material, and can further reduce the size and weight. The purpose is.

[0006]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention provides an oil tank at the base end of a tool body in which a hydraulic circuit equipped with a low pressure control valve and a high pressure control valve is installed, and an output piston is provided at the tip of this tool body. In a manual hydraulic tool that has a pump mechanism that is equipped with a cylinder to be housed and that sucks the hydraulic oil in the oil tank by rocking the pressure handle and pumps it to the cylinder, the pump mechanism is the tool body. A small diameter plunger chamber that is fitted to a large diameter plunger chamber that is open to the tip side, and that is fitted to the small diameter plunger chamber and that has an oil passage that penetrates the shaft core. And an inner piston that is fixed to the tool body with its tip connected to the hydraulic circuit.The low pressure hydraulic oil from the large diameter plunger chamber fast-forwards the output piston. It proposes a piston fast forward mechanism of the manual hydraulic tool pressurizing the output piston by high pressure hydraulic fluid from the small-diameter plunger chamber.

[0007]

[Action]

 When the plunger moves up, hydraulic oil from the oil tank is introduced into the large diameter plunger chamber and small diameter plunger chamber, and when the plunger moves down, the hydraulic oil in the large diameter plunger chamber and small diameter plunger chamber is pushed out and supplied to the cylinder. Sent to fast forward the output piston. When the rapid movement is completed and the output piston is loaded by the multiple swing operations of the pressure handle, a large amount of hydraulic oil from the large diameter plunger chamber is returned to the oil tank via the low pressure regulating valve, A small amount of hydraulic oil from the small diameter plunger chamber is boosted into high pressure oil that pressurizes the output piston to do its work. The small-diameter plunger chamber is formed inside the large-diameter plunger chamber, and the inner piston fitted in this small-diameter plunger chamber is fixed, and a large amount of low-pressure oil and a small amount of high-pressure oil can be obtained only by the vertical movement of the plunger. The pump can be operated easily with a light force, the volume occupied by the pump mechanism in the tool body is small, and the degree of freedom in arranging the high-pressure regulating valve is increased, which enables downsizing of the tool body. Weight reduction is possible.

[0008]

【Example】

 Hereinafter, the manual hydraulic tool of the present invention will be described with reference to the drawings. 1 is a side sectional view of an essential part of a manual hydraulic tool according to the present invention, FIG. 2 is a plan sectional view of an essential part of the tool of FIG. 1, and FIG. 3 is a front sectional view of an essential part of the tool of FIG. FIG. 7B is a diagram showing a downward movement state of the plunger, and FIG. 8B is a diagram showing an upward movement state of the plunger.

As shown in FIG. 1, a fixed handle 3 which also serves as a storage portion for an oil tank 2 is attached to a base end portion of a tool body 1, and a large diameter plunger chamber 4 is formed on an upper portion thereof. Then, the plunger 5 is fitted, and a small diameter plunger chamber 6 having a concentric shape is formed inside the plunger 5 and an inner piston 7 is fitted therein. The inner piston 7 has an oil passage 8 penetrating the shaft center, and a lower end portion thereof is fixed to the tool body 1 by screwing. The oil passage 8 is internally provided in the tool body 1 as described later. It is in communication with. Further, the upper part of the plunger 5 is locked by a locking shaft 11 of a pressure handle 10 which is pivotally supported by a pivot 9 of the upper support column 1a of the tool body 1. It is configured as a pump mechanism that can repeatedly move the plunger 5 up and down.

Further, a return mechanism for returning the 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 biased upward by the spring 12 is pushed down by rotating the pressurizing handle 10 to push the return valve 15 biased by the spring 14 open, and the hydraulic circuit is closed. It is designed so that it can communicate with the tank 2. Further, a cylinder 16 is formed at the tip of the tool body 1, and a piston 18 biased to the base end side by a spring 17 is housed inside the cylinder 16 and the tip of the piston 18 is provided at the tip. A movable die 19 is detachably attached.

The hydraulic circuit provided in the tool body 1 will be described with reference to FIGS. 2 and 3. An oil strainer 20 is attached to the suction port from the oil tank 2, and a suction oil passage 21 following the oil strainer 20 is branched, and one of the branch passages communicates with a low pressure oil passage 23 via a suction valve 22. Further, the low pressure oil passage 23 is communicated 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 communicated with the oil tank 2 via a low-pressure regulating valve 25, so that low-pressure hydraulic oil of a predetermined oil pressure or higher is supplied to the oil tank. It can be returned to 2.

The other branch passage from the intake oil passage 21 communicates with the high-pressure oil passage 27 via the intake valve 26, and the upper portion of the inner piston 7 via the oil passage 8 in the inner piston 7. The small-diameter plunger chamber 6 is communicated with. The high pressure oil passage 27 is opened at the bottom of the cylinder 16 via a check valve 28. Further, a high-pressure regulating valve 29 is arranged below the plunger 5 in a form orthogonal to the front-rear direction of the tool body 1, and is connected to a high-pressure oil passage 30 communicating with the bottom of the cylinder 16 to return high-pressure oil of a predetermined pressure or higher to the return oil. It can be returned to the oil tank 2 via the path 31. Furthermore, 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 working oil in the hydraulic circuit is returned to the oil via the return oil passage 33 (FIG. 1). It can be returned to tank 2 forcibly.

In the manual hydraulic tool A of the present invention thus configured, the plunger 5 is moved up and down by holding the fixed handle 3 and swinging the pressure handle 10. That is, when the plunger 5 in the state of FIG. 3 (a) is moved up to the state of FIG. 3 (b), the large-diameter plunger chamber 4 and the inner piston 7 formed below the plunger 5 are moved upward. The formed small-diameter plunger chamber 6 becomes negative pressure, and one suction valve 22 is opened to operate to the large-diameter plunger chamber 4 from the oil tank 2 via the oil strainer 20, the suction oil passage 21, and the low-pressure oil passage 23. While the oil is sucked, the other suction valve 26 is opened and the hydraulic oil is sucked into the small diameter plunger chamber 6 via the high pressure oil passage 27.

Next, when the plunger 5 moves downward, the suctioned hydraulic oil is pressurized, and the discharge valve 24 and the discharge valve 28 are pushed open to be fed into the cylinder 16. Since a large amount of hydraulic oil in the large-diameter plunger chamber 4 is fed, the piston 18 in the cylinder 16 is fast-forwarded. When the movable die 19 comes into contact with the work piece and receives a load, the hydraulic oil in the hydraulic circuit communicating with the cylinder 16 is increased in pressure, and when a low pressure of a predetermined pressure is reached, a large amount of oil from the large diameter plunger chamber 4 is released. The hydraulic oil of 1 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, pushes the piston 18, and when it reaches a predetermined high pressure, the hydraulic oil pushes the high pressure regulating valve 29 open via the high pressure oil passage 30, It is returned to the oil tank 2 via the return oil passage 31 to keep the oil pressure in the hydraulic circuit on the cylinder 16 side constant, and to push the movable die 19 to perform work such as crimping. When the operation is completed, the pressurizing handle 10 is rotated to move downward and the release pin 13 of the return valve mechanism is pushed to open the return valve 15, and the hydraulic oil on the cylinder 16 side causes the high pressure passage 32 and the return valve 15 to move. It is returned to the oil tank 2 via the return oil passage 33.

In the present embodiment, a small diameter plunger chamber 6 is formed inside the plunger 5, and an inner piston 7 having one end fixed to the tool body 1 is housed therein. Similarly, by vertically moving the plunger 5, a large amount of low pressure oil is generated to fast-forward the piston 18, and the piston 18 can be easily pushed by a small amount of high pressure oil with a light force. Therefore, in this pump mechanism, the volume of the plunger 5 occupying 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, which was arranged in parallel with the stepped plunger and the return valve mechanism, can be arranged below the plunger 5, and the dimension of the tool body 1 in the front-rear direction can be shortened and the extension dimension of the hydraulic circuit can be reduced. It was possible to shorten the length, and to reduce the size and weight of the manual hydraulic tool and improve workability.

[0016]

[Effect of device]

 As is apparent from the above description, according to the present invention, the inner piston is fitted by providing the small diameter plunger chamber in the plunger that moves up and down by engaging with the pressure handle. The volume occupied by the pump mechanism is significantly reduced compared to the conventional pump mechanism, and the degree of freedom in arranging the regulator valve is increased, for example, the high-pressure regulator valve can be placed in the lower part of the pump mechanism, and the tool body is small and lightweight. It is possible to improve the workability by shortening the hydraulic circuit.

[Brief description of drawings]

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

FIG. 2 is a plan sectional view of an essential part of the manual hydraulic tool of FIG.

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

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

[Explanation of symbols]

 A Manual 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 Intake oil Line 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)

[Scope of utility model registration request] 1. An oil tank is attached to a base end of a tool body having a hydraulic circuit including a low pressure control valve and a high pressure control valve, and a cylinder for accommodating an output piston is formed at a tip end of the tool body. In the manual hydraulic tool including a pump mechanism that sucks the hydraulic oil in the oil tank by the swinging operation of the pressure handle and pressure-feeds it to the cylinder, the pump mechanism is a large-diameter plunger chamber formed in the tool body. A plunger having a small-diameter plunger chamber concentrically formed and opening to the tip side, and a small-diameter plunger chamber fitted to the small-diameter plunger chamber and having an oil passage penetrating the shaft core to communicate with the hydraulic circuit. In this state, the tip part is fixed to the tool body, and the output piston is fast forwarded by the low pressure hydraulic oil from the large diameter plunger chamber, and the high pressure from the small diameter plunger chamber is increased. A piston rapid feed mechanism for a manual hydraulic tool, characterized in that the output piston is pressurized by pressure hydraulic oil.