JP4259082B2 - Impact tool - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention converts the rotational motion of the commutator motor to a reciprocating motion of the piston sliding in the cylinder, like an electric hammer, and uses an air spring to follow the impactor and transmit continuous impact to the tip tool. The present invention relates to a device for preventing a hitting operation in a hitting tool.
[0002]
[Prior art]
For hammering tools such as electric hammers that perform crushing and crushing operations such as concrete, the tip tool is pressed against the work material from the state where the commutator motor is rotating without load and the piston is reciprocating. Even if it moves to the striking position, if the striking element amplitude or rebound speed is small when the piston vibration is transmitted through the air spring, the striking element's vibration energy is not amplified, so that the striking action does not shift to the striking action. There is a defect. In order to prevent hitting failure of conventional hitting tools, generally hitting such as shortening the hitting position, extending the crank eccentricity, reducing the weight of the hitting element, reducing sliding resistance, changing the end face shape of the mesonment, etc. Change the specifications, change the motor specifications such as reducing the no-load speed, add a constant speed control circuit that forcibly cuts the no-load speed, and stop the trigger switch that allows continuous operation without constantly holding the trigger. There are no operations such as switching on / off.
[0003]
In addition, there is one that starts and stops an electric motor by a switch or a clutch mechanism (for example, see Patent Document 1).
[Patent Document 1]
Shokai 59-69871
[Problems to be solved by the invention]
In the above-mentioned countermeasures for preventing hitting malfunction of conventional hitting tools, changes in hitting specifications and motor specifications forced the structural structure of the hitting mechanism and deceleration part to change significantly, and hitting malfunctions were prevented. There has been a problem that the performance of the main body and the operability are lowered due to the reduction in the life of the impact tool main body due to the occurrence of an unsatisfactory strike, which is contrary to the malfunction, and the reduction in impact energy and the increase in reaction. In addition, the expansion of the constant speed control circuit can surely prevent the blow operation failure, but there is a problem that the expansion space is secured and the cost is greatly increased. Furthermore, in order to turn on / off the trigger switch at the start of striking, it is necessary to constantly hold the trigger during the operation, resulting in a problem that the operability is deteriorated.
An object of the present invention is to eliminate the above-mentioned drawbacks of the prior art, to prevent a hitting operation failure of this type of hitting tool, and to further improve the main body performance, operability, and durability.
[0004]
[Means for Solving the Problems]
The above purpose is to convert the rotational motion of the commutator motor into the reciprocating motion of the piston sliding in the cylinder, use the air spring to follow the impactor, and transmit the continuous impact to the tip tool via the intermediate. In the impact tool, the switch is turned on by pressing the tip tool against the work material, the commutator motor is started and the impact is started, and the switch is turned off by moving the tip tool away from the work material. A switch that opens and closes a large breathing hole provided in an air chamber so that the commutator motor stops and stops hitting, and a switch that turns ON and OFF by the movement of the sleeve to start and stop the commutator motor To prevent the striker from following the reciprocating motion of the piston when the commutator motor is started, thereby preventing a bad strike operation. Blood phenomenon forcibly prevention is accomplished by setting the optimum blow specifications motor specification.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described below with reference to FIGS. Housing the tip tool 1 transmits the continuous strike through intermediate member 5 slidable in the tool axis direction while being guided by the retainer sleeve 4 to fitting engagement with the front cover 3 fixed to the cylinder case 2 to tip tool 1 An air chamber 10 is formed between an impactor 7 that can slide in the cylinder 6 and a piston 9 that reciprocates in the cylinder 6 by the rotational movement of the commutator motor 8. The cylinder 6, the supported one side tool bit in the cylinder case 2 and the cylinder holder 11 to be fitted to the front cover 3 is supported to the piston 9 side at the cylinder casing within 2. The intermediate member 5 and the hammer holder 12 to be engaged is fitted to the cylinder holder 11, and is slidably engaged with an inner diameter portion of the cylinder case 2.
The cylinder 6 is provided with a large breathing hole 13 communicating with the air chamber 10, and the hammer holder 12 is moved to the cylinder holder 11 via the intermediate element 5 and the hammer holder 12 by pressing the tip tool 1 against the work material. Until it abuts on the cylinder 6, it moves against the bias of the spring 14 provided on the outer periphery of the cylinder 6, seals the large breathing hole 13 provided in the air chamber 10, and separates the tip tool 1 from the work material. Thus, the sleeve 15 that is moved by the biasing of the spring 14 and opens the large breathing hole 13 is slidably fitted in the axial direction of the cylinder 6 and biased toward the axial tip tool 1 by the spring 14. Has been. A sensor 16 for detecting the movement of the sleeve 15 in the axial direction of the cylinder 6 is disposed in the cylinder case 2 and is turned on and off by a signal from the sensor 16 to start and stop the commutator motor 8. 17 is embedded in the handle 18.
When the tip tool 1 is pressed against the work material, the striking element 7 moves to the striking position via the intermediate element 5, and until the sleeve 15 abuts against the cylinder holder 11 via the intermediate element 5 and the hammer holder 12. It moves against the bias of the spring 14, seals the large breathing hole 13 provided in the air chamber 10, detects that the sleeve 15 has moved by the sensor 16, turns on the switch 17, and the commutator motor 8 Starts. As a result, the piston 9 starts to reciprocate, and the striking element 7 follows the reciprocating movement of the piston 9 by the air spring, and transmits continuous striking to the tip tool 1 via the intermediate element 5.
When the impact tool main body is lifted and the tip tool 1 is separated from the work material, the sleeve 15, the hammer holder 12 and the intermediate element 5 are moved forward in the tool axis direction by the bias of the spring 14, and the large breathing hole 13 provided in the air chamber 10. , The sensor 16 no longer senses the sleeve 15, so the switch 17 is turned off and the commutator motor 8 stops. Along with the above, the striking stops.
[0006]
【The invention's effect】
According to the present invention, since the commutator motor is started when the impact tool body is pressed and the impact is started, and when the impact tool body is lifted, the commutator motor is stopped and the impact can be stopped. It is possible to prevent the occurrence of bad hits such as bad hitting behavior and blank shot phenomenon, widening the range of hitting specifications and motor specifications, and the handle part can be easily gripped because there is no switch trigger. An impact tool with further improved performance, operability, and durability can be provided.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view at the start of hitting showing an embodiment of the present invention.
FIG. 2 is a longitudinal sectional view at the time of stopping hitting showing an embodiment of the present invention.
[Explanation of symbols]
1 is a tip tool, 2 is a cylinder case, 3 is a front cover, 4 is a retainer sleeve, 5 is an intermediate, 6 is a cylinder, 7 is an impactor, 8 is a commutator motor, 9 is a piston, 10 is an air chamber, 11 is A cylinder holder, 12 is a hammer holder, 13 is a large breathing hole, 14 is a spring, 15 is a sleeve, 16 is a sensor, 17 is a switch, and 18 is a handle.

Claims (1)

Stroke that transforms the rotational motion of the commutator motor into reciprocating motion of the piston that slides in the cylinder, uses the air spring in the air chamber to follow the impactor, and transmits continuous impact to the tip tool via the intermediate In the tool, a cylinder provided with a large breathing hole communicating with the air chamber, a slidably fitted in the cylinder axial direction, and urged in one axial direction by a spring to press the tip tool against the work material And move against the bias of the spring through the meson, seal the large breathing hole provided in the air chamber, and move by the bias of the spring by separating the tip tool from the work material. A sleeve that opens a large breathing hole and a switch that is turned on and off by the movement of the sleeve in the cylinder axial direction to start and stop the commutator motor are provided, and the tip tool is pressed against the work material. Pickpocket And the switch is turned ON, the commutator motor is started to start striking, and the tip tool is moved away from the work material to close the large breathing hole provided in the air chamber. A striking tool characterized in that a sleeve moves to open a large breathing hole provided in the air chamber and the switch is turned off to stop the commutator motor and stop striking.

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