CN-114952737-B - Impact tool

CN114952737BCN 114952737 BCN114952737 BCN 114952737BCN-114952737-B

Abstract

The invention provides an impact tool. The movable support body supports the final output shaft and the drive mechanism at least partially, and is integrally movable with respect to the housing in the axial direction of the drive axis. The urging member urges the movable support toward the front side in the axial direction. The 1 st guide shaft extends in the axial direction and slidably guides the movable support to move in the axial direction. At least 1 intermediate shaft is configured to rotate with rotation of the motor shaft and transmit power of the motor to the driving mechanism. At least 1 bearing supports the front end portion in the axial direction in the 1 st intermediate shaft. The single metal support body is configured not to move relative to the housing and supports at least 1 bearing. The single metal support body has a1 st hole, and the 1 st guide shaft is partially inserted into the 1 st hole. Accordingly, both high power and low vibration can be achieved.

Inventors

Yoshikane Yoshinobu
MACHIDA YOSHITAKA
KUNO TARO
NAKAGAWA KAZUTOSHI

Assignees

株式会社牧田

Dates

Publication Date: 20260508
Application Date: 20220215
Priority Date: 20210222

Claims (11)

1. An impact tool, characterized in that, Comprising a final output shaft, a motor, a drive mechanism, a housing, a movable support, a force application member, a1 st guide shaft, at least 1 intermediate shaft, at least 1 bearing, and a single metal support, The final output shaft is configured to removably retain a tip tool and define a drive axis of the tip tool; The motor has a motor shaft; The driving mechanism is configured to perform at least a hammering motion for driving the tip tool in a straight line along the driving axis by a power of the motor; The housing accommodates the motor and the driving mechanism; the movable support body at least partially supports the final output shaft and the drive mechanism, and is configured to be integrally movable with respect to the housing in an axial direction of the drive axis; When a side of the axis direction on which the final output shaft is disposed is defined as a front side and a side of the axis direction on which the motor is disposed is defined as a rear side, the urging member urges the movable support toward the front side in the axis direction; The 1 st guide shaft is configured to extend in the driving direction and slidably guide the movable support to move in the axial direction; The at least 1 intermediate shaft extends in the axial direction, and the at least 1 intermediate shaft is configured to rotate with rotation of the motor shaft to transmit power of the motor to the driving mechanism; The at least 1 bearing supports an end portion of the at least 1 intermediate shaft on the front side in the axial direction; The single metal support body is configured not to move with respect to the housing and supports the at least 1 bearing, and has a1 st hole in which the 1 st guide shaft is partially inserted.
2. The impact tool of claim 1, wherein the impact tool comprises a plurality of blades, The housing is made of resin and is made of a material such as a plastic, The metal support is fixed to the housing.
3. The impact tool of claim 1, wherein the impact tool comprises a plurality of blades, The metal support body has a1 st positioning portion on the front side, the 1 st positioning portion is disposed so as to circumferentially surround the final output shaft, The housing has a 2 nd positioning portion arranged so as to circumferentially surround the final output shaft, The 1 st positioning portion and the 2 nd positioning portion are shaped to match each other in a fitting manner in the axis direction.
4. The impact tool of claim 2, wherein the impact tool comprises a plurality of blades, The metal support body has a1 st positioning portion on the front side, the 1 st positioning portion is disposed so as to circumferentially surround the final output shaft, The housing has a 2 nd positioning portion arranged so as to circumferentially surround the final output shaft, The 1 st positioning portion and the 2 nd positioning portion are shaped to match each other in a fitting manner in the axis direction.
5. An impact tool as claimed in claim 3, wherein, The metal support body has a mounting surface on a front side, the mounting surface is spread on a single plane at a position radially outside the 1 st positioning portion, The mounting surface abuts the housing in the axis direction.
6. The impact tool of claim 1, wherein the impact tool comprises a plurality of blades, The 1 st guide shaft is disposed at least partially on the front side of the movable support, The impact tool further includes a2 nd guide shaft, and the 2 nd guide shaft is disposed coaxially with the 1 st guide shaft so as to be positioned at least partially on the rear side of the movable support.
7. The impact tool of claim 6, wherein the impact tool comprises a plurality of blades, The 1 st guide shaft extends forward from the movable support body and is configured to be movable integrally with the movable support body in the axial direction.
8. The impact tool of claim 7, wherein the impact tool comprises a plurality of blades, The metal support body is provided with a1 st sleeve formed by iron-based metal in the 1 st hole, The 1 st guide shaft is configured to slide on an inner peripheral surface of the 1 st sleeve along with the movement of the movable support body along the axial direction, The metal support is formed of an aluminum-based metal except for the 1 st sleeve.
9. The impact tool of claim 6, wherein the impact tool comprises a plurality of blades, The movable support body has a2 nd hole and a2 nd sleeve, wherein the 2 nd guide shaft is partially inserted in the 2 nd hole, the 2 nd sleeve is disposed in the 2 nd hole, The 2 nd guide shaft is configured to be immovable relative to the housing, The inner peripheral surface of the 2 nd sleeve is configured to slide on the 2 nd guide shaft along with the movement of the movable supporting body along the axial direction, The urging member is disposed around the 2 nd guide shaft at a position on the rear side in the axial direction from the movable support, and is configured to urge the movable support including the 2 nd sleeve integrally to the front side.
10. The impact tool as claimed in any one of claims 1 to 9, wherein, The driving mechanism is further configured to perform a drilling operation for rotationally driving the tip tool about the driving axis by power of the motor, The at least 1 intermediate shaft has a1 st intermediate shaft configured to transmit power for the hammer action to the drive mechanism and a2 nd intermediate shaft configured to transmit power for the drilling action to the drive mechanism, The at least 1 bearing has a1 st bearing supporting the 1 st intermediate shaft and a2 nd bearing supporting the 2 nd intermediate shaft, The 1 st intermediate shaft is configured to transmit the hammer motion but not transmit the drilling motion, The 2 nd intermediate shaft is configured to transmit the drilling motion but not the hammering motion.
11. The impact tool of claim 10, wherein the impact tool comprises a plurality of blades, The 1 st bearing and the 2 nd bearing are disposed at positions offset from each other in the axial direction.

Description

Impact tool Technical Field The present invention relates to an impact tool configured to linearly drive a tip tool. Background The hammer drill is configured to be capable of performing a hammering operation for driving a distal tool attached to the tool holder in a straight line along a drive axis, and a drilling operation for rotationally driving the distal tool attached to the tool holder about the drive axis. In general, a motion conversion mechanism for converting rotational motion of an intermediate shaft into linear motion is used for performing hammering operation, and a rotation transmission mechanism for transmitting rotation through an intermediate axial tool holder is used for performing drilling operation. In this hammer drill, a reaction force against an impact force of a tip tool is received from a workpiece when performing a hammering operation. The reaction force mainly generates vibration in a direction along which the drive axis extends (hereinafter also referred to as an axis direction). The vibrations will be transmitted to the housing of the hammer drill and even to the user. Japanese patent laid-open publication No. 6325360 discloses a structure for absorbing such vibrations. Specifically, the holding member that holds the driving mechanism for performing the hammering operation is configured to be slidable along the guide shaft with respect to the housing. The holding member is biased forward (i.e., in the direction in which the urging member urges the workpiece). When the tip tool receives a reaction force in response to the hammering operation, the drive mechanism and the holding member move backward relative to the housing together with the tip tool. At this time, the biasing member is elastically deformed, and a part of the reaction force is buffered. By this damping action, the vibration transmitted to the housing due to the reaction force is reduced. In general, a hammer drill is made of a resin material as much as possible for the purpose of weight reduction, not limited to japanese patent application laid-open No. 6325360. For example, a casing defining the outer contour of a hammer drill is generally made of resin. In addition, the member for supporting the bearing for supporting the intermediate shaft is also generally made of resin. Disclosure of Invention There is room for improvement in the hammer drill of japanese patent laid-open publication No. 6325360. For example, when the hammer drill is made to have a large power, the reaction force increases and the generated vibration also increases, so that when the peripheral portion of the bearing for supporting the intermediate shaft is made of resin, sufficient strength may not be obtained to secure the position accuracy required for the intermediate shaft. In addition, when the hammer drill is increased in power, heat generated by sliding of the holding member holding the driving mechanism and the guide shaft is also increased. Therefore, in the case where the member for supporting the bearing for supporting the intermediate shaft is made of resin, there is a possibility that the position accuracy required for the intermediate shaft is no longer obtained due to thermal expansion of the resin with an increase in the amount of heat generated. In the case where the guide shaft is supported by a resin member, thermal expansion of the resin occurs with an increase in the amount of heat generated, and as a result, sliding properties between the holding member and the guide shaft are impaired, and as a result, vibration isolation may be impaired. Such a problem is not limited to hammer drills, but is present in various impact tools in which a holding member holding a driving mechanism for performing a hammering action is configured to be capable of sliding movement along a guide shaft with respect to a housing. In view of the above, an object of the present invention is to provide an impact tool capable of achieving both high power and low vibration. The present specification discloses an impact tool. The impact tool may have a final output shaft, a motor, a drive mechanism, a housing, a movable support, a biasing member, a1 st guide shaft, at least 1 intermediate shaft, at least 1 bearing, and a single metal support. The final output shaft may be configured to removably retain the tip tool. In addition, the final output shaft may define a drive axis of the tip tool. The motor may have a motor shaft. The driving mechanism may be configured to perform at least a hammering motion for driving the tip tool linearly along the driving axis by the power of the motor. The housing may house the motor and the drive mechanism. The movable support may at least partially support the final output shaft and the drive mechanism. The movable support may be configured to be integrally movable with respect to the housing in the axial direction of the drive axis. When the side of the axis direction on which the final output shaft is disposed is def