JPH01316178A - Blank shot preventing device for percussion tool - Google Patents

Abstract

PURPOSE:To facilitate the assembling and disassembling of a gripping member and prolong its life by forming the gripping member with a cylindrical steel member and an elastic body formed en bloc in the steel member, and installing the gripping member in a cylinder which holds the member at the position of engagement as a percussion piece advances. CONSTITUTION:A cylindrical gripping member 4 is incorporated in a black shot preventing device for a percussion tool 3, which takes hold of a percussion piece 2 moving in the direction toward the tool after the tool 3 moved over a specified distance in its axial direction when hit with the percussion piece 2 at the detachment of the tool 3 from a work piece. The griping member 4 is formed with a cylindrical steel member 4a and an elastic body 4b formed en bloc in the steel member, and installed in a cylinder 5 which holds the gripping member 4 at the position of engagement as the percussion piece 2 advances. The gripping member 4, therefore, can be pressure-installed and fixed in the bore part of the cylinder 5 from one side and removed from the other side by pushing it up. That is, the gripping member 4 can be easily assembled and disassembled and its life can be prolonged.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a dry striking prevention device for a striking tool.

[Conventional technology]

Conventionally, in order to prevent dry firing, when the striker moves forward, an elastic body such as an O-ring is provided in the groove of the inner diameter of the cylinder as a holding member in front, and a stepped structure is provided at the end of the striker. After passing through the O-ring, it was locked, fixing the striking element.

[Problem to be solved by the invention]

In the above-mentioned prior art, since an O-ring groove is provided in the inner diameter portion of the elongated pipe-like cylinder that holds members such as a tool, a second hammer, a striker, and a piston, it is difficult to process the groove for attaching the O-ring. Furthermore, it is difficult to remove the O-ring attached to this groove. Furthermore, installation
It is necessary to greatly deform the O-ring, and the shape and hardness of the O-ring are limited, making it impossible to extend the life of the O-ring.
That is, there were many problems such as a short life span of the dry firing prevention device.

The present invention has been made in view of the above points, and it is an object of the present invention to provide a dry striking prevention device for a striking tool, which allows easy assembly and disassembly of a gripping member and extends the life of the tool.

[Means to solve the problem]

The above purpose is to form a gripping member from a cylindrical steel material and an elastic body integrally provided inside the steel material, and to form a cylinder that holds the gripping member in a position where it engages when the striker moves forward. This can be achieved by wearing it.

[Effect]

The gripping member is formed of a cylindrical steel material and an elastic body integrally provided inside the steel material, and is attached to the cylinder holding the gripping member at a position where it engages when the striker moves forward. The gripping member can be press-fitted into the inner diameter of the pipe-shaped cylinder from one side and removed by pushing it up from the other side, making assembly and disassembly of the gripping member easier and extending its life. .

〔Example〕

The present invention will be explained below based on the illustrated embodiments. An embodiment of the present invention is shown in FIGS. 1-5.

As shown in the figure, when the tool 3 is separated from the workpiece of a striking tool that drives the striking element 2 through the air by the reciprocating motion of the piston 1 and strikes the tool 3, the striking element 2, the tool 3 is moved a predetermined distance in the axial direction, and the impact tool has a cylindrical gripping member 4 that grips the impactor 2 that has moved in the direction of the tool. In this embodiment, the gripping member 4 is formed of a cylindrical steel material 4a and an elastic body 4b integrally provided inside the steel material 4a, and the gripping member 4 is provided at a position where it engages when the striker 2 moves forward. It was attached to the cylinder 5 that holds the member 4. By doing this, the gripping member 4 can be press-fitted into the inner diameter of the pipe-shaped cylinder 5 from one side and removed by pushing it up from the other side, making assembly and disassembly of the gripping member 4 easy and long-lasting. Accordingly, it is possible to obtain a dry striking prevention device for a striking tool that makes it possible to

That is, in FIG. 1, motor rotation is transmitted to the intermediate shaft 8 via the output shaft pinion 6 and the first gear 7. A reciprocating bearing 9 press-fitted into the intermediate shaft 8 rotates together with the intermediate shaft 8, and drives the piston 1 reciprocally through the piston pin 10.

The tool 3, which hit the workpiece and retreated, has a second
An air chamber 12 provided between the piston 1 and the striker 2 via the hammer 11 causes the striker 2 to reciprocate due to the force of the air spring generated by the reciprocation of the piston 1, and the end face of the second hammer 11 is The impact force generated by the impact is transmitted. When the tool 3 is released from the workpiece, the second hammer 11 struck by the striker 2 and the tool 3 move forward as shown in FIG. It stops. The striker 2 also follows this and jumps forward, once expanding the elastic body 4b on the inner diameter part of the gripping member 4, and the stepped portion 2a at the end of the striker 2 stops after passing. The diameter D2 of the stepped portion 2a at the end of the striker 2 is 1
Assuming that the inner diameter of the gripping member 4 is D□, Dz>Dx is maintained.

An appropriate value for this difference is selected depending on the ability of the impact tool. When the striking element 2 moves to this position, it no longer follows the reciprocating motion of the piston 1, so that dry striking stops. Next, when restoring the impact, the tool 3 is pressed against the workpiece. The second hammer 11 retreats, pushes up the end of the striker 2, releases the engagement between the gripping member 4 and the striker 2, and operates again. The gripping member 4 can be assembled by press-fitting it from the inner diameter portion of the piston side of the cylinder 5, and conversely, can be disassembled by pushing it up together with the second hammer 11 from the tool side with the tool 3 removed. Note that 13 in FIG. 1 is a needle roller.

As described above, according to this embodiment, the structure of the gripping member is formed by two types of members, namely, an elastic body such as rubber on the inner diameter part and a ring-shaped steel material on the outer diameter part, and this gripping member is press-fitted into the cylinder. Since it is fixed, it is easy to process the inner diameter of the cylinder, and it is also easy to disassemble and assemble.

By appropriately selecting the material and hardness, it is possible to obtain a dry firing prevention device that is easy to assemble and disassemble and has a long life.

The steel material constituting the gripping member may not only be formed into a ring shape as in this embodiment, but may also be formed into a C-shaped ring with a cut-off point.

〔Effect of the invention〕

As described above, the present invention makes it possible to obtain a dry striking prevention device for a striking tool in which the gripping member is easy to assemble and disassemble and has a long life, and the gripping member is easy to assemble and disassemble and has a long life. .

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional side view of an embodiment of the dry striking prevention device for a striking tool of the present invention, and FIG. 2 is a longitudinal sectional side view showing a state in which the tool of the embodiment moves forward and the dry striking prevention device is activated. FIG. 3 is a longitudinal side view of a gripping member according to an embodiment, FIG. 4 is a front view of a gripping member according to an embodiment, and FIG. 5 is a front view of a striker according to an embodiment. 1 is a piston, 2 is a striker, 2a is a stepped portion at the end of the striker, 3 is a tool, 4 is a gripping member, 4a is a steel material, 4b is an elastic body, and 5 is a cylinder. ChilI2] 2′- and the pipe φ- and the poem \゛? 4-and! Left hand side 5 11 7
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Claims (1)

[Claims] 1. Drive the striking element through air by reciprocating movement of the piston,
When the tool of a striking tool that strikes a tool is separated from the workpiece, the tool struck by the striker moves a predetermined distance in the axial direction, and follows this and moves in the tool direction. In a dry striking prevention device for a striking tool having a cylindrical gripping member that grips a striking element, the grasping member is formed of a cylindrical steel material and an elastic body integrally provided inside the steel material, and the striking A dry striking prevention device for a striking tool, characterized in that the device is mounted on a cylinder holding the gripping member at a position where it engages when the child moves forward. 2. The dry striking prevention device for a striking tool according to claim 1, wherein the gripping member has an inner diameter smaller than a diameter of a stepped portion at an end of the striking element. 3. The dry striking prevention device for a striking tool according to claim 1, wherein the steel material of the gripping member is formed of a C-shaped ring cut at one place.