JPH0417295Y2 - - Google Patents

Description

[Detailed description of the invention] "Prior art" The present invention relates to a tool for cutting, punching, crimping, caulking, bending, etc. metal materials such as metal pipes, reinforcing bars, and iron plates using hydraulic pressure, and is particularly concerned with tools for cutting, punching, crimping, caulking, bending, etc. The present invention relates to a hydraulically operated tool characterized by a valve mechanism disposed in the valve mechanism.

"Prior Art and its Problems" Various cutters, for example, have been developed that use hydraulic power and are portable and easy to handle, in order to cut reinforcing bars, metal pipes, etc. at construction sites and the like. For example, this type of cutter is equipped with a pump mechanism in the casing body of a cutter equipped with an oil tank that pumps the oil in the oil tank into a cylinder, and the hydraulic pressure from this pump mechanism is slidably arranged in the cylinder. By sliding the piston head connected to the piston head forward and moving the piston rod connected to the piston head in a straight line, the cutting blade attached to the tip of the piston rod cuts the object to be cut, such as reinforcing bars or metal pipes. A valve mechanism has been proposed in which a valve mechanism is installed in order to release the pressure oil fed into the cylinder to the outside of the cylinder and cause the piston head and piston rod to retreat again.

However, in this conventional hydraulically operated cutter, the valve mechanism must be internally installed concentrically with the piston head, so although the cylinder space for housing the valve mechanism has been reduced, this valve mechanism requires a This requires a guide bar that projects in the axial direction, and the valve body is attached to the guide bar and inserted into the piston rod, which complicates the structure of the valve mechanism itself. Furthermore, in order to be able to handle large-diameter objects to be cut, it is necessary to increase the stroke of the piston rod, which requires the length of the guide bar. However, increasing the length of the guide bar requires high processing accuracy and is difficult to form. Further, in the conventional piston, the guide bar, the inner diameter of the cylinder, the piston rod, and the piston head must all be in concentric positions to function properly. These concentricities also require high accuracy. Therefore, more advanced molding technology is required to satisfy all of these conditions.

``Purpose of the invention'' This invention solves the above problems all at once.It has an extremely simple structure, does not require high processing precision, is easy to process, and has an accurate opening/closing operation for the oil release passage. It is an object of the present invention to provide a hydraulically operated tool having a valve mechanism.

"Summary of the invention" The hydraulically operated tool of the invention greatly simplifies the structure of the valve mechanism.

That is, in the present invention, the oil release passage is provided at an eccentric position with respect to the axis of the piston rod, and the valve mechanism is constituted by a columnar sliding valve that is slidable in the axial direction within the piston rod. The tip has an elastic valve part that closes the opening of the oil release passage at the peripheral edge by elastic deformation, and when oil is released, the elastic valve part holds the columnar sliding valve in the open position with respect to the oil release passage with its elastic recovery force. It is characterized by

"Embodiment of the invention" Below, a cutter will be described as an example of a hydraulically operated tool according to the invention.

1 to 3 are sectional views showing a first embodiment of the present invention. In the figure, reference numeral 1 denotes a motor, which is attached to the casing body 3 with a motor shaft 2 directly connected to the motor 1 and inserted into the casing body 3. A cylinder 4 is connected to the casing body 3, and the cylinder body 3
An oil tank 5 for storing oil is formed inside. Further, the casing body 3 is provided with a pump mechanism for pumping oil from the oil tank 5 into the cylinder. The pump mechanism 6 includes a cam portion 7 formed on the motor shaft 2, a piston 9 that reciprocates with the cam portion 7 via a needle bearing 8, and is connected to the piston 9 via a spring 10.
It consists of an on-off valve 12 arranged in an oil passage 11. The oil passage 11 and the oil passage 14 are formed in communication with the cylinder 4, and the on-off valve 12 normally blocks communication between the oil passage 11 and the oil passage 14 by the elastic force of the spring 13. .

A piston head 15 is disposed within the cylinder 4 so as to be slidable in the axial direction concentrically with the axis of the cylinder 4, and a piston rod 16 is connected to the piston head 15 in the axial direction. In the figure, the piston rod 16 moves forward in the right direction and moves backward in the left direction. This piston rod 16 is
Although it is preferable to form it at the axial center of the piston head 15, it is also permissible to form it eccentrically with respect to the axial center of the piston head 15. An oil release passage 17 is provided in the center of the cylinder 4, which communicates the inside of the cylinder 4a with an oil tank 5 outside the cylinder. This oil release passage 17 is located at an eccentric position with respect to the axis of the piston rod 16.

An insertion hole 1 is provided at the axis of the piston rod 16 for inserting the valve mechanism 18 from the inner wall side of the cylinder 4.
9 is formed. A cylindrical guide portion 20 is fitted into the insertion hole 19 and fixed to the piston head 15 with a fixing screw. Therefore, the guide portion 20 moves together with the piston rod 16. This guide portion 20 is provided with an oil passage 21 that communicates the inside of the cylinder 4a with the insertion hole 19. This oil passage 21 functions to introduce the pressure oil in the cylinder 4a into the insertion hole 19 and cause it to be applied to the valve mechanism 18.

The valve mechanism 18 opens and closes the opening of the oil release passage 17 located eccentrically from the axis of the piston rod 16, and includes a slide valve 38 formed in a columnar shape. The columnar sliding valve 38 is inserted into the insertion hole 19 and is slidable in the axial direction while slidingly contacting the inner surface of the guide portion 20 . A mounting hole 39 is formed at the tip of the columnar sliding valve 38, and an elastic valve portion 40 is fitted into the mounting hole 39. Elastic valve part 4
0 is elastically deformed by being pressed toward the oil release passage 17, and its outer peripheral closing portion 40a sits on the opening of the oil release passage 17 and closes it. Therefore, the elastic valve portion 40 is molded from a material with excellent elastic recovery force, such as rubber or soft synthetic resin. In the free state, the elastic valve part 40 has a central part of its valve surface in a concave shape as shown in FIG.
Alternatively, it can be formed into a convex shape as shown in FIG. Further, when oil is released, the elastic valve portion 40 functions to maintain the oil release passage 17 in an open state due to its elastic recovery force. It acts as a float spring to release the ball. The length of the columnar sliding valve 38 having the elastic valve portion 40 can be changed as appropriate depending on the stroke of the piston rod 16.

On the outer periphery of the columnar sliding valve 38, a screw flange 4 is provided.
1 is formed. This hard flange 41
When the piston rod 16 reaches its most advanced position, it comes into contact with the inner end of the guide portion 20 and functions to separate the columnar slide valve 38 from the opening of the oil release passage 17.

Also, the piston head 15 and the jaw-shaped casing 2
A spring 28 is interposed between the spring 28 and the spring 7. This spring 28 is connected to the piston head 15.
The bullet is biased in the direction of retreating (toward the left in the figure). In addition, 29 is a cutting blade attached to the tip of the piston rod 16, 30 is an object to be cut by this cutting blade 29, and 31 is an air bag for adjusting the change in the volume of the inside of the cylinder 4a.

Next, the operation of the hydraulically operated cutter having the above configuration will be explained.

As shown in FIG. 1, the piston head 15 is
When the motor 1 is driven with the motor 1 positioned at the rearward end within the cylinder 4, the cam portion 7 rotates in synchronization with the rotation of the motor shaft 2, and the piston 9 reciprocates via the needle bearing 8. The reciprocating movement of the piston 9 forces the oil in the oil tank 5 toward the oil passage 14. The pressure oil generated by the pump mechanism 6 is applied to the on-off valve 12 against the elastic force of the spring 13.
4a inside the cylinder through the oil passage 14.
will be pumped to. The pressure oil forced into the cylinder 4a acts on the flange surface of the piston head 15,
The piston head 15 is moved in the forward direction against the elastic force of the spring 28. As a result, the piston rod 16 also moves forward, and the piston rod 16
The cutting blade 29 at the tip cuts the object 30.
The pressure oil in the cylinder 4a also fills the insertion hole 19 through the oil passage 21 formed in the guide portion 20, and presses the columnar sliding valve 38 in the seating direction. Therefore, due to the elastic deformation of the elastic valve portion 40 of the columnar sliding valve 38, the outer peripheral closing portion 40a is seated at the opening of the oil release passage 17, thereby closing the passage 17.

While the piston head 15 is moving forward, the resilient valve portion 40 of the columnar sliding valve 38 remains seated at the opening of the oil release passage 17, and the oil release passage 17 is closed by the columnar sliding valve 38. It is kept in a closed state.

When the piston head 15 reaches its most advanced position, the inner end of the guide portion 20 comes into contact with the kick flange 41 and presses it. Then, the outer circumferential closing portion 40a of the elastic valve portion 40 instantly separates from the oil release passage 17, and maintains the open state with respect to the oil release passage 17 due to its elastic recovery force. This results in
The pressure oil in the cylinder 4a flows from the oil release passage 17 toward the oil tank 5, the pressure difference on both sides of the flange surface of the piston head 15 is eliminated, the movement of the piston head 15 in the forward direction is stopped, and the cutting blade 2
The cutting operation of the object 30 by 9 is completed.

When the piston head 15 stops, the spring 28, which has been compressed by the piston head 15, pushes the piston head 15 back in the backward direction (toward the left in the figure) by its elastic force. During this time, due to the elastic recovery force of the elastic valve portion 40, the columnar sliding valve 38 closes its outer circumferential closing portion 40a to the oil release passage 17.
The seat is maintained apart from the opening. Since the oil release passage 17 is open, the piston head 15 quickly slides in the backward direction along the columnar slide valve 38 via the guide portion 20. Then, the bottom of the insertion hole 19 of the piston rod 16 collides with the head surface of the columnar slide valve 38 to move the columnar slide valve 38 in the seating direction, thereby causing the elastic valve portion 40 to release its elasticity. Oil release passage 17 due to deformation
The outer peripheral closing portion 40a hermetically closes the oil release passage 17. At this time, the backward movement of the piston head 15 is stopped, and one step of the cutting operation is completed.

The above is an explanation about the cutter, but instead of the cutting blade 29, another tool, such as a punching tool,
It is also possible to use it by attaching a bending tool or the like.

"Effects of the Invention" As explained above, according to the hydraulically operated tool of the present invention, the oil release passage is opened and closed only by the columnar sliding valve that slides within the piston rod according to the movement of the piston head. The structure of the valve mechanism is extremely simple, easy to process, and does not require high processing accuracy. Further, at the time of oil release, the elastic recovery force of the elastic valve body maintains the unseated state of the columnar sliding valve with respect to the oil release passage, so that reseating at the time of oil release can be prevented. Furthermore, it is possible to accommodate a piston rod with a large stroke by changing the length of the columnar sliding valve.

[Brief explanation of the drawing]

1 to 3 show a first embodiment of a hydraulically operated cutter according to the present invention, FIG. 1 is an overall sectional view of the cutter, and FIG. FIG. 3 is a cross-sectional view showing the essential parts of FIG. 2 together with the seated state, and FIGS. 4 and 5 show a second embodiment of the present invention. FIG. 4 is a diagram of the columnar sliding valve in a seated state, and FIG. 5 is a diagram of the same in a unseated state. 4...Cylinder, 6...Pump mechanism, 11,1
4, 21...Oil passage, 15...Piston head,
16... Piston rod, 17... Oil release passage, 18... Valve mechanism, 19... Insertion hole, 20...
Guide part, 38... Column sliding valve, 39... Mounting hole, 40... Elastic valve part, 40a... Outer periphery closing part,
41...Kitsuku flange.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A casing body provided with an oil tank, a cylinder connected to this casing body, a piston head slidably disposed within this cylinder, and a piston head connected to this piston head. a piston rod provided with a tool attached to the tip thereof, a pump mechanism for pumping oil in the oil tank into the cylinder to advance the piston head and piston rod in the axial direction, and communicating between the inside and outside of the cylinder,
an oil release passage that releases pressure oil to the outside of the cylinder;
In a hydraulically operated tool, the oil release passage is equipped with a valve mechanism that opens and closes the opening of the oil release passage according to the movement of the piston head and piston rod, and the piston rod is provided concentrically or eccentrically with respect to the axis of the piston head. The passage is provided at an eccentric position with respect to the axis of the piston rod, and the valve mechanism is composed of a columnar sliding valve that is slidable in the axial direction within the piston rod, and the columnar sliding valve has an opening for an oil release passage at its tip. The elastic valve part has an elastic valve part that closes at the peripheral edge by elastic deformation, and when oil is released, the elastic valve part
A hydraulically operated tool characterized in that its elastic recovery force holds a columnar sliding valve in an open position relative to an oil release passage. (2) The hydraulically operated tool according to claim 1, wherein the elastic valve portion has a central portion of the valve surface facing the oil release passage formed in a concave or convex shape.