JPH0329105Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to the improvement of a hydraulic tool used for terminal processing of power cables, etc., and in particular, the inner diameter of the end of the cylinder integrally formed with the fixed head is reduced to a smaller diameter. The present invention relates to a double-acting hydraulic tool structure having a stepped portion.

[Conventional technology]

In general, tools used for so-called terminal processing work such as cutting and compressing power cables, etc.
The movable head, which is hydraulically operated in the direction of the fixed head, grips and holds the material to be terminated.

However, during this work, the movable head sometimes digs into the cable or the like that is the material to be terminated, and even if an attempt is made to separate it, there is a problem in that it cannot be easily returned with the restoring force of the spring bias. Therefore, the applicant of the present application previously disclosed in Japanese Patent Application No. 60-013912 a hydraulic tool device in which a movable head is forcibly movable in both directions by hydraulic pressure. That is, as shown in FIG. 3, the structure is such that a hollow cylindrical ram piston 33 is slidably inserted into a cylinder 32 that is integrally formed with a fixed head 31.
A movable head 34 is connected to the fixed head 31 at its head.
It is set opposite to. A fixed piston 35 is inserted through the axial center of the hollow ram piston 33, and a cap 36 is attached to the end of the ram piston 33 located on the opposite side of the movable head 34. Further, below this cap 36, that is, at the end where the cylinder 32 has a slightly larger diameter, an end cap 37 forming a two-system oil passage for returning pressure oil is screwed. A first oil chamber 38 for hydraulically driving the ram piston 33 is formed in a gap with the cap 36.

On the other hand, it is movable in a space partitioned by a gap between the outer peripheral surface of a fixed piston 35 located inside the ram piston 33 and the inner peripheral surface of the ram piston 33, and a cap 36 attached to the end of the ram piston 33. Second oil chamber 3 for forcibly returning the head 34
9 is formed.

[Problem that the invention attempts to solve]

However, in the above conventional hydraulic tools, the end cap is screwed into the cylinder at the end of the fixed head, so pressure oil is supplied to the first oil chamber at the base of the ram piston, and the end cap is screwed into the cylinder at the end of the fixed head. When the hydraulic pressure increases due to the lift, the hydraulic reaction force acts on the threaded portion, and the threaded portion receives this force. Therefore, in order to stabilize the strength of the screw joint, it was necessary to increase the thickness of the cylinder and the like accordingly. There is also the problem that extra length must be provided on the cylinder side of the fixed head to accommodate the threading of the end cap, which makes it impossible to reduce the weight and size of the entire tool, resulting in high costs and resource savings. It was also contrary. Furthermore, the rotation angle of the fixed head and movable head with respect to the ram piston and end cap was limited, and could only be rotated by a maximum of 180 degrees, making workability somewhat difficult.

[Means for solving problems]

This idea was created in view of the above problems.
The aim is to provide a hydraulic tool that is lighter and more compact and has improved workability by further improving the above-mentioned hydraulic tool.Specifically, the tool includes a fixed head integrally formed with the cylinder and a movable head. A hydraulic tool in which the movable head is operated by a piston in the cylinder, wherein a stepped portion smaller than the inner diameter of the cylinder is formed at the end of the cylinder, and a locking portion is provided between the piston and the small diameter stepped portion. A pressure receiving cap with an integrally formed flange is inserted and brought into contact with the stepped portion, an oil chamber is provided between the pressure receiving cap and the piston, and an end cap that contacts the pressure receiving cap is rotated at the end of the cylinder. A double-acting hydraulic tool structure characterized by being freely installed.
It was configured as

[Effect]

According to the hydraulic tool structure having the above configuration, the hydraulic reaction force when pressure oil is supplied between the piston and the pressure cap is applied to the pressure cap fitted into the cylinder, and the locking flange of the pressure cap is It is received by contacting the small diameter stepped portion at the end of the cylinder.

Furthermore, the end cap is provided outside the tool body and can rotate 360° relative to the tool body.

〔Example〕

An embodiment of the present invention will be described below based on the drawings.

FIG. 1 is a sectional view of a main part of a double-acting hydraulic tool, and in this embodiment, a compression tool head is shown as an example.

In the figure, a hydraulic tool body 1 includes a fixed head 2 and a cylinder 3 that are integrally formed, and the inner peripheral surface of the cylinder 3 is honed. The inner diameter of the cylinder 3 is reduced only at the right end to form a stepped portion 3A, and this portion is processed using a special machine by a method called backbore processing. A ram piston 4 having a hollow cylindrical shape with a small inner diameter at the right base is slidably inserted into the cylinder 3, and a movable head 5 is attached to the left head of the ram piston 4 into the hollow hole of the ram piston 4. It is pivoted by fitting its end. Therefore, the movable head 5
The ram piston 4 slides in the direction of the fixed head 2 integrally with the ram piston 4.

A concave groove 4A is formed on the right side circumferential surface of the ram piston 4, and an O-ring 6 for preventing leakage of pressure oil and a back-up for preventing the O-ring 6 from being bent are formed in the groove 4A. A ring 7 is fitted on the outside. An elongated fixed piston 8 is inserted into the ram piston 4, and only its left head portion has a large diameter and is in sliding contact with the inner circumferential surface of the ram piston 4. The other side of the fixed piston 8 is in sliding contact with the small diameter portion of the ram piston 4, and is inserted through the center of the pressure receiving cap 9 to protrude outside the tool body 1.
An end cap 22, which will be described later, can now be attached.

The pressure receiving cap 9 is fitted from the inside into a small diameter stepped portion 3A formed at the end of the cylinder 3, and a flange portion (large diameter portion) 9A integrally formed on the pressure receiving cap 9 is connected to the stepped portion 3A. They are designed to come into contact and be locked. Further, the left end surface of the pressure receiving cap 9 is in contact with the base of the ram piston 4, and a first
An oil chamber 10 is formed. Incidentally, an O-ring 11 and a back-up spring 12 are fitted onto the circumferential surface of the pressure-receiving cap 9, which is in sliding contact with the small-diameter portion 3A of the cylinder 3, to prevent leakage of pressure oil. Furthermore, sealing O-rings 13, 14, 15 and back-up springs 16, 17, 18 are fitted inside the ram piston 4 and the pressure receiving cap 9, with which the fixed piston 8 slides on the outer peripheral surface.

By the way, the gap between the inner peripheral surface of the ram piston 4 and the outer peripheral surface of the fixed piston 8, and the gap between the inner peripheral surface of the ram piston 4 and the outer peripheral surface of the fixed piston 8
A second oil chamber 19 is formed in a space partitioned by the large diameter portion 8A of the ram piston 4 and the small diameter base portion of the ram piston 4.
This oil chamber 19 and an oil passage 20 formed at the axis of the fixed piston 8 are electrically connected through a communication hole 21 .

At the end of the right cylinder 3 of the tool body 1, an end cap 22 is screwed onto the shaft of the fixed piston 8 in close contact with the pressure receiving cap 9. A gap S is formed on the circumference. By providing this gap S, in the unlikely event that the O-ring 11 and the
Even if pressure oil leaks due to damage to the rings 24B, 26B, the force of the leakage can be reduced, and danger can be prevented.

The end cap 22 is capable of rotating 360 degrees with respect to the tool body 1, that is, the fixed head 2.

The end cap 22 has a 2
Two ports 23A and 23B are provided, the first port 23A is connected to the first oil chamber 10 through communication between the oil passage 24 and the oil passage 25 formed in the pressure receiving cap 9, and the second port 23B is connected to the first oil chamber 10. The oil passage 26 and the oil passage 27 provided at an angle in the pressure receiving cap 9 are connected to the oil passage 20 formed at the axis of the fixed piston 8, thereby opening the second oil chamber 19.
It is connected to.

Note that sleeves 24 are provided in the oil passages 24 and 26, respectively.
A, 26A is inserted, and this sleeve 24
O-rings 24B and 26B are fitted onto A and 26A. By providing the sleeves 24A, 26A, the O-rings 24B, 26B are prevented from being drawn into the oil passage by the flow of hydraulic oil.

In addition, a relief valve 28 is connected to the second port 23B as shown in FIG. 2, and high oil pressure exceeding the set pressure acts on the hydraulic circuit of the second port 23B including the second oil chamber 19. If this occurs, the oil is released to the first oil chamber 10 to reduce the pressure. 29 and 30 are couplers for connecting hydraulic hoses (not shown).

The above two ports 23A and 23B function so that when one is a pressure port, the other becomes a return port, and the switching operation of this hydraulic circuit was previously disclosed in Japanese Patent Application No. 60-013912 by the applicant.
Since this is done using the rotary valve disclosed in the above issue, detailed explanation will be omitted here.

Next, the operation of this embodiment will be explained.

First, when compressing a material to be processed, the first port 23A is used as a pressure port P, and the second port 23B is used as a return port R. That is, when pressure oil is supplied to the pressure port 23A by switching a rotary valve (not shown), the pressure oil flows into the first oil chamber 10 through the oil passage 24 and the oil passage 25 of the pressure receiving cap 9. As a result, the base surface of the ram piston 4 is pressurized, and the ram piston 4 comes to slide to the left (upward) in the figure within the cylinder 3. As a result, ram piston 4
A movable head 5, which is provided integrally with the terminal, slides toward the left fixed head 2 to grip and hold the material to be terminated, thereby allowing desired termination work to be performed. During this work, a reaction force due to hydraulic pressure comes to act on the pressure cap 9, but this reaction force is caused by the contact between the small diameter stepped portion 3A of the cylinder 3 and the flange (large diameter portion) of the pressure cap 9. can be received by Also,
As the ram piston 4 slides, the oil in the second oil chamber 19 is removed by the fixed piston 8 from the end cap 22.
Since the fixed piston 8 is in a fixed state, it is compressed by the large diameter head portion 8A of the fixed piston 8, and the oil passage 2 is compressed from the communication hole 21.
0, the oil passes through the oil passage 27 and the oil passage 26, and is discharged through the second port 23B as the return port R.

On the other hand, in order to move the movable head 5 away from the material to be processed in the return direction, the rotary valve (not shown) is switched and the second port 23 is moved away from the movable head 5.
B is the pressure port P, and the first port 23
This is done with A as the return port R. When pressure oil is supplied to the second port 23B, the oil flows into the second oil chamber 19 following a path opposite to that at the time of discharge. Then, the right inner end surface of the ram piston 4 is pressurized and pushed down to the right (downward) in the figure.

Accordingly, the movable head 5 fixed to the ram piston 4 can be separated from the material to be terminated and returned to its current state. Also, at this time, the first oil chamber 1
When the ram piston 4 moves downward, the oil in the ram piston 4 is discharged through the oil passage 25 and the oil passage 24 using the first port 23A as a return port R.

In this return operation, if it is difficult to return the movable head 5 because, for example, a power cable or the like gets caught in the head part, the hydraulic circuit of the second port 23B including the second oil chamber 19 will increase the pressure. When the pressure exceeds the pressure, the relief valve 28 opens to reduce the pressure, and the movable head 5 is prevented from returning any further by force, thereby preventing damage to various parts.

As described above, this embodiment has been described as an example equipped with a compression head, but it is of course applicable to the head of other cutters, etc., and the same effect as described above can be obtained.

[Effect of idea]

As is clear from the above explanation, the present invention provides the following practical effects.

(1) It is possible to reduce the weight by approximately 20% compared to the conventional model, making it lighter and more compact. This also leads to lower manufacturing costs and resource conservation. Furthermore, the lighter weight also improves operability.

(2) There is no screw connection between the tool body and end cap, resulting in stable strength.

(3) The tool body can now rotate 360°, greatly improving work efficiency.

[Brief explanation of drawings]

Fig. 1 is a vertical cross-sectional view of the main part of the double-acting hydraulic tool of the present invention, Fig. 2 is a cross-sectional view taken along the line X-X in Fig. 1, and Fig. 3 is the main part of the double-acting hydraulic tool of the conventional example. FIG. 1... Tool body, 2... Fixed head, 3... Cylinder, 4... Ram piston, 5... Movable head, 8... Fixed piston, 9... Pressure receiving cap,
10...First oil chamber, 19...Second oil chamber, 22
...End cap, 23A...First port,
23B...Second port, 28...Relief valve.

Claims (1)

[Scope of utility model registration request] A hydraulic tool comprising a fixed head integrally formed with a cylinder and a movable head, the movable head being operated by a piston in the cylinder,
A stepped portion having a diameter smaller than the inner diameter of the cylinder is formed at the end of the cylinder, and a pressure receiving cap integrally formed with a locking flange is inserted between the piston and the small diameter stepped portion to abut against the stepped portion. A double acting hydraulic tool structure, characterized in that an oil chamber is provided between the pressure receiving cap and the piston, and a rotatable end cap that abuts the pressure receiving cap is provided at the end of the cylinder.