JPH071260Y2 - Hammer tool - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Use of the Invention] The present invention relates to an impact tool having an intermediate impactor such as a hammer and a hammer drill.

[Background of the Invention] Generally, a hammer drill having a grease lubrication hermetic structure hits a tip tool 6 via an intermediate hitting element 5 as shown in FIG. When the main body is separated from the object to be crushed (Fig. 3), the striker 4, the intermediate striker 5, and the tip tool 6 move forward, but the outer diameter d ₁ of the striker housing chamber 7 is outside the intermediate striker 8. Since the diameter is larger than the diameter d ₂ , the pressure of the striking element storage chamber 7 and the intermediate striking element 8 after movement is positive due to the compression action. Here, the hitting element storage chamber 7 refers to a space (room) formed in front of the hitting element 4 in the range in which the hitting element 4 moves in the cylinder 10, and the intermediate hitting element storage chamber 8 is It is a range in which the intermediate striker 5 moves within the cylinder 10 and is a space (room) surrounded by the intermediate striker 5 and the inner surface of the cylinder 10 in front of the striker housing chamber 7. Therefore, there is a drawback that the hitting element 4 is repelled, and the hitting is continued even under a no-load condition (hereinafter referred to as idle hitting), leading to a reduction in the life of the machine body.

[Purpose of device]

An object of the present invention is to eliminate the above-mentioned drawbacks of the prior art and to prevent a blank hit to prevent damage to the airframe.

[Outline of device]

According to the present invention, the outer diameter d ₁ of the striker housing chamber 7 and the intermediate striker are adjusted so that the pressure in the striker housing chamber 7 and the intermediate striker housing chamber 8 after the forward movement of the striker 4 becomes negative pressure or atmospheric pressure. Outer diameter of child storage room 8 d ₂
It is a device that devises the relationship between.

[Example of device]

 An embodiment of the present invention will be described below.

The power of the electric motor is converted into a linear reciprocating motion of the piston 3 in the cylinder 10 by the crankshaft 1 and the connecting rod 2. The reciprocating motion of the piston 3 is transmitted to the striker 4 by an air spring between the piston 3 and the striker 4, and the striker 4 strikes the tip tool 6 via the intermediate striker 5 and crushes concrete or the like. The outer diameter d ₂ of the intermediate striker storage chamber 8 is larger than the outer diameter d ₁ of the striker storage chamber 7. Naturally, the striker storage chamber 7 and the intermediate striker storage chamber 8
In order to allow the movement of air between them, the striker storage chamber 7 and the intermediate striker storage chamber 8 communicate with each other.

When the machine body is separated from the object to be crushed such as concrete, the tip tool 6 advances until it hits the stop lever 9, and similarly the intermediate hitting element 6 and the hitting element 4 also move forward. At this time, since the outer diameter d ₂ of the intermediate striker storage chamber 8 is larger than the outer diameter d ₁ of the striker storage chamber 7,
The total volume of both spaces (chambers) after movement increases, and the internal pressure becomes negative pressure. For this reason, the rebound of the hitting element 4 is sucked up, and idle hitting is prevented.

[Effect of device]

According to the present invention, since the hitting element is prevented from rebounding and the idle hitting is prevented, the life of the machine body can be improved.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view of an essential part showing an embodiment of a striking tool according to the present invention. FIG. 2 is a vertical cross-sectional side view of an essential part showing a conventional load. FIG. 3 is a vertical cross-sectional side view of an essential part showing a conventional non-loaded state. In the figure, 4 is a striker, 5 is an intermediate striker, 6 is a tip tool, 7 is a first air chamber, 8 is a second air chamber, and 10 is a cylinder.

Claims (1)

[Scope of utility model registration request] 1. A striking element that is moved in the axial direction of the tip tool by the reciprocating motion of a piston, an intermediate striking element that is striking by the striking element and transmits a striking force to the tip tool, the striking element and the intermediate striking element. A striking tool having a built-in cylinder, wherein a striking element storage chamber for accommodating the impacting element and an intermediate impacting element accommodating chamber for accommodating the intermediate impacting element are formed in communication with each other. A percussion tool having an outer diameter of the striker housing chamber equal to or larger than an outer diameter of the striker housing chamber.