JP2549587Y2 - Impact tool - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a striking tool for transmitting the compression of air, such as a hammer and a hammer drill, to a tip tool through a striker having a sealing elastic body.

[0002]

2. Description of the Related Art A conventional impact tool has a structure in which an outer diameter of a striker and an outer diameter of a collar of the striker are made equal to each other in a striker provided with a sealing elastic body, and sealing is performed by interference of the elastic body. ,
There is a structure in which a small-diameter hole is provided in the striker tool rib between the elastic body and the air chamber, and the pressure of the air chamber is applied to the side surface of the elastic body.

[0003]

The conventional structure in which the sealing is performed only by the interference of the elastic body impairs the sealing performance when the elastic body wears, and significantly shortens the service life. Selection was difficult. Further, in the case of a structure in which a small diameter hole is provided in the rib of the striker, the strength of the hole is reduced and the rib is damaged. Alternatively, the pressure of the air chamber is biased to the vicinity of the hole, and it is difficult to apply the pressure to the entire elastic body.

An object of the present invention is to provide a striking tool capable of extending the sealing life of an elastic body attached to a striking element.

[0005]

In order to achieve the above-mentioned object, a striking tool according to the present invention comprises a reciprocating piston, a cylindrical cylinder for guiding the piston, and an air chamber inside the cylindrical cylinder. A hammer that is reciprocally driven by the piston and a ring-shaped sealing elastic body that seals air on the piston side of the hammer, wherein a gap between the sealing elastic body and the air chamber is provided. Wherein the outer diameter of the collar of the striker is smaller than the inner diameter of the piston.

[0006]

The striking tool according to the present invention is provided with a sealing elastic body for sealing air on the air chamber side of the striking element, and the outer diameter D2 of the striking element between the sealing elastic body and the air chamber is determined by a piston. Is smaller than the inner diameter D1, the compressed air from the gap (D1-D2) has a gap between the width of the mounting groove of the sealing elastic body provided on the striker and the thickness of the sealing elastic body. ,
Also, it acts on the gap between the bottom surface of the groove for assembling the striker and the inner diameter of the sealing elastic body, and the force for pushing the sealing elastic body toward the intermediate striker and the force for pushing and expanding the inner circumferential direction of the piston act. The sealing performance of the air chamber is improved. For this reason, even if abrasion occurs in the sealing elastic body, the sealing property is maintained and the life can be extended.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is a sectional view of an embodiment of the sealing mechanism of the impact tool according to the present invention, and FIG. 2 is a sectional view showing the relationship between the mounting groove for the sealing elastic body and the sealing elastic body of FIG. It is sectional drawing. In FIG. 1, 1 is an output shaft pinion, 2 is a first gear, 3 is an intermediate shaft, 4 is a reciprocating bearing, 5 is a piston pin, 6 is a piston, 7 is a cylinder, 8 is an air chamber, 9 is a striker, and 10 is a striker. Intermediate striker, 11 is a tool, 12
Is a sealing elastic body, 13 is an assembling groove, and 14 is a collar of the striker. The rotation of the motor is transmitted to the intermediate shaft 3 via the output shaft pinion 1 and the first gear 2. Intermediate shaft 3
The reciprocating bearing 4 press-fitted into the shaft rotates integrally with the intermediate shaft 3, and reciprocates the piston 6 via the piston pin 5. An air chamber 8 provided between the piston 6 and the striker 9 via a structure is provided to the tool 11 which is abutted against the work material and retreats.
Gives the thrust to the striker 9 by the action of the air spring generated by the reciprocation of the piston 6, and the striking force generated by striking the end face of the intermediate striker 10 is transmitted.

In the structure shown in FIG. 2, when the piston 6 and the striker 9 come closest to each other, the pressure in the air chamber 8 formed by the inner periphery of the piston 6, the rear end of the striker 9 and the sealing elastic body 12 becomes high. Further, this pressure is generated by providing a relationship of D1> D2 between the inner diameter D1 of the piston 6 and the outer diameter D2 of the collar of the striker 9, and the air compressed from the gap having the dimension of (D1-D2) is generated. A gap between the width of the groove 13 for assembling the elastic body 12 for sealing provided on the striker 9 and the thickness of the elastic body 12 for sealing;
Further, a force acting on the gap between the bottom surface of the mounting groove 13 of the striker 9 and the inner diameter of the sealing elastic body 12 to press the sealing elastic body 12 toward the intermediate striker 10 and the inner circumferential direction of the piston 6 The force for spreading acts to improve the sealing performance of the air chamber 8. For this reason, the interference of the sealing elastic body 12 can be reduced, and even if the sealing elastic body 12 is worn, the sealing property is maintained and the life can be extended.

In the above, an example in which the air chamber 8 is constituted by the interior of the piston 6 and the striker 9 has been described as an embodiment. The present invention is also applicable to a striking tool having a structure in which the air chamber 8 is constituted by the striking element 9.

[0011]

According to the present invention, since the outer diameter of the flange of the striker between the sealing elastic body and the air chamber is smaller than the inner diameter of the piston, the compressed air in the air chamber is compressed by the sealing elastic body. A force that presses the body and presses it in the direction of the intermediate striker and a force that spreads it in the inner circumferential direction of the piston act, thereby extending the life of the sealing elastic body.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an embodiment of a sealing mechanism of a hitting tool according to the present invention.

FIG. 2 is a partial cross-sectional view showing a relationship between a sealing elastic body assembling groove and a sealing elastic body of FIG. 1;

[Explanation of symbols]

6 ... piston, 8 ... air chamber, 9 ... hitting element, 12 ... sealing elastic body, 13 ... mounting groove, 14 ... hitting element flange.

Claims (1)

(57) [Scope of request for utility model registration] A piston that reciprocates, a cylindrical cylinder that guides the piston, a striker reciprocally driven by the piston through an air chamber inside the cylindrical cylinder, and the piston of the striker A striking tool including a ring-shaped sealing elastic body that seals air on its side, wherein an outer diameter of a collar of the striker between the sealing elastic body and the air chamber is smaller than an inner diameter of the piston. A striking tool characterized in that: