JPH07266256A - Hammer tool - Google Patents

Abstract

(57) [Abstract] [Purpose] The present invention is to easily inform a user of an abnormality caused by damage to a seal member of a striking tool and to reduce repair cost of an airframe. [Structure] A piston 9 is provided with an air chamber 11 and a vent hole 12 communicating with the atmospheric pressure, and the vent hole 12 is sealed by an elastic body 6. A projecting portion 5 smaller than the minimum approach distance between the piston 9 and the striker 3 is formed on the air chamber end surface of the striker 3. When a metal collision between the piston 9 and the striker 3 occurs due to wear of the seal members 4 and 7, the projecting portion 5 of the striker pushes the elastic body 6 provided on the piston 9 in the axial direction, and the vent hole of the piston 9 is formed. Since 12 is opened to atmospheric pressure, the compression by the piston 9 is obstructed and the movement of the striker 3 is stopped.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention, like an electric hammer,
The present invention relates to an improvement of a device for striking a tool having a striking element driven by reciprocating movement of a piston and air pressure.

[0002]

2. Description of the Related Art A conventional striking device of this type is reciprocally fitted in a shaft cylinder portion into which a tool is loosely inserted, and a striking member for directly striking the tool and a reciprocating densely striking member. Is composed of a piston for reciprocating, and the striking element and the piston are for reciprocating the piston and compressing the internal air, thereby advancing the striking element to collide with a tool. Therefore, with regard to the airtightness of the air chamber, various problems are caused due to this, so that great care has been taken to hermetically seal the outer circumferences of the piston and the striker.

[0003]

In the conventional striking device, when the seal member or the like is worn for a long period of time or with poor lubrication, a metal collision between the piston and the striking element occurs and the device is damaged. there were. The object of the present invention is to avoid damage to the device caused by the above-mentioned poor sealing,
It is to inform the user of the repair time.

[0004]

The above object is to provide a piston with a vent hole for communicating an air chamber composed of a striker and the piston with the atmosphere, and seal the vent hole with an elastic body. This is achieved by causing the elastic body mounted on the piston to protrude by a certain amount so as to press. It is also achieved by causing the elastic body to project from the end face of the piston on the side of the striker by a certain amount.

[0005]

In the striking device configured as described above, when the seal material is worn, the piston and the striking element collide with each other, the elastic body blocking the ventilation hole of the piston moves to the piston side, and the ventilation hole is opened. It operates so that the air chamber composed of the striker and the piston communicates with the atmosphere.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described with reference to FIGS. FIG. 1 is a vertical cross-sectional view of a striking device of an electric hammer that strikes a tip tool 1 to crush a workpiece.
FIG. 2 is a partially enlarged view in which the vent hole 12 of the piston 9 is sealed with the elastic body 6. FIG. 3 is an enlarged view when the air chamber 11 composed of the piston 9 and the striker 3 collides with the piston 9 and the striker 3 due to the wear of the seal members 4 and 7.
The elastic body 6 and the vent hole 12 of the piston 9 are sealed by taper fitting, and axial movement is fixed by a flange portion. The vent hole 12 of the piston 9 is formed to open when the elastic body 6 moves in the axial direction on the piston pin 8 side at an arbitrary distance. At the center of the striker 3 on the piston 9 side, a protrusion 5 is formed that is smaller than the maximum approach distance between the piston 9 and the striker 3. In the above configuration, when the piston 9 and the hitting element 3 collide with each other due to wear of the seal members 4 and 7, the elastic body 6 is pressed by the projecting portion 5 of the hitting element 3 and moves to the piston pin 8 side, The vent hole 12 of the piston 9 is opened, the air chamber becomes atmospheric pressure, the compression of the air by the piston 9 is obstructed, and the movement of the striker is stopped. Even if the projecting portion 5 is not provided on the striker 3, even if the elastic body 6 is projected from the end surface of the piston 9, the motion of the striker is similarly stopped.

[0007]

According to the present invention, since the piston is provided with the vent hole communicating with the air chamber and the atmospheric pressure, and the vent hole is sealed with the elastic body, the phenomenon of metal collision between the piston and the impactor due to the wear of the seal material is prevented. Since the user can easily detect the abnormality, the device can be repaired only by replacing the sealing material without damaging the device.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of a striking device for a striking tool according to the present invention.

FIG. 2 is an enlarged vertical sectional view of a hitting device according to the present invention.

FIG. 3 is an operation diagram of the striking device according to the present invention.

[Explanation of symbols]

1 is a tip tool, 2 is a cylinder, 3 is a striker, 4 and 7 are seal members, 5 is a protrusion, 6 is an elastic body, 9 is a piston, 1
Reference numeral 1 is an air chamber, and 12 is a ventilation hole.

Claims (3)

[Claims] 1. A striking tool comprising a cylinder, a piston that reciprocates in the cylinder, and a striking element that is striked by the piston via air in the air chamber, wherein the piston has the air chamber and atmospheric pressure. The ventilation hole which leads to
A striking tool characterized in that the vent hole is sealed with an elastic member. 2. The impact tool according to claim 1, wherein the elastic body is made to protrude from the end surface of the piston on the air chamber side by a predetermined amount. 3. The striking tool according to claim 1, wherein a projecting portion projecting by a certain amount is formed on the end surface of the striking member on the air chamber side.