Impact tool

Patent metadata

Field	Value
Publication number	US-11845169-B2
Application number	US-202217846307-A
Country	US
Kind code	B2
Filing date	Jun 22, 2022
Priority date	Jun 11, 2019
Publication date	Dec 19, 2023
Grant date	Dec 19, 2023

Abstract

An impact tool includes a motor, a driving mechanism, a tool body, an elastically-connected part elastically connected to the tool body to be movable at least in a front-rear direction relative to the tool body, a detecting mechanism configured to detect pressing of a tool accessory against a workpiece, and a control part configured to control driving of the motor based on a detection result of the detecting mechanism. The detecting mechanism includes a movable member that is provided in one of the tool body and the elastically-connected part and configured to be moved by relative movement of the other of the tool body and the elastically-connected part in the front-rear direction, and a detector that is provided in the one of the tool body and the elastically-connected part and configured to detect rearward pressing of the tool accessory by detecting movement of the movable member.

First claim

What is claimed is:

1. An impact tool, comprising:
a motor;
a driving mechanism configured to linearly drive a tool accessory along a driving axis by power of the motor, the driving axis defining a front-rear direction of the impact tool;
a housing that houses the motor and the driving mechanism; and
at least one dynamic vibration reducer, each of the at least one dynamic vibration reducer including a weight, a front spring in front of the weight, a rear spring behind the weight and a housing part, the weight being linearly movable in the front-rear direction, the weight, the front spring and the rear spring being housed in the housing part, wherein:
the driving mechanism includes:
a crank shaft configured to rotate by power of the motor;
a cylinder extending along the driving axis in the front-rear direction; and
a piston configured to reciprocate along the driving axis within the cylinder in response to rotation of the crank shaft;

the housing includes:
a motor housing that houses the motor;
a crank housing that houses the crank shaft; and
a barrel part that (i) is in front of the crank housing and (2) houses the cylinder;

a first part of the barrel part that is integral with a remainder of the barrel part is a portion of the housing part;
a first part of the crank housing that is integral with a remainder of the crank housing is another portion of the housing part;
the housing part includes a cylindrical member that extends in the front-rear direction and that houses at least a portion of the weight;
the first part of the barrel part and the first part of the crank housing are spaced in the front-rear direction and support the cylindrical member;
the cylindrical member is held by the housing by a biasing force of at least one of the front spring and the rear spring;
the first part of the barrel part (i) has a cylindrical shape with a closed end and (ii) receives an end of the front spring such that the closed end receives a biasing force of the front spring.

2. The impact tool as defined in claim 1 , wherein:
the motor includes a motor shaft rotatable around a rotation axis;
the rotation axis is orthogonal to the driving axis and defines an up-down direction of the impact tool;
the motor housing is on a lower side of the crank housing; and
the crank housing and the motor housing are fixedly connected by screws, between the first part of the barrel part and the first part of the crank housing in the front-rear direction.

3. The impact tool as defined in claim 1 , wherein either one of the first part of the barrel part and the first part of the crank housing is configured as a spring-receiving part configured to receive a biasing force of the at least one of the front spring and the rear spring.

4. The impact tool as defined in claim 1 , wherein the at least one dynamic vibration reducer includes two dynamic vibration reducers that are symmetrical relative to a plane that contains the driving axis.

5. The impact tool as defined in claim 1 , wherein:
an internal space of the housing part includes a first space in front of the weight and a second space behind the weight;
the first part of the barrel part has a first air passage providing communication between an internal space of the barrel part and the first space; and
the first part of the crank housing has a second air passage providing communication between an internal space of the crank housing and the second space.

6. The impact tool as defined in claim 1 , wherein:
the first part of the crank housing has a cylindrical shape; and
the cylindrical member is inside the first part of the crank housing and supported by the first part of the crank housing.

7. The impact tool as defined in claim 6 , wherein the cylindrical member is biased rearward relative to the first part of the barrel part by the at least one of the front spring and the rear spring and held in abutment with a stopper in the housing.

8. The impact tool as defined in claim 7 , wherein:
an internal space of the housing part includes a first space in front of the weight and a second space behind the weight;
the first part of the barrel part has a first air passage providing communication between an internal space of the barrel part and the first space; and
the first part of the crank housing has a second air passage providing communication between an internal space of the crank housing and the second space.

9. The impact tool as defined in claim 8 , wherein:
the stopper is configured to position the cylindrical member in the circumferential direction relative to the first part of the barrel part and the first part of the crank housing by engaging with a portion of the cylindrical member.

10. The impact tool as defined in claim 6 , wherein the first part of the barrel part, the first part of the crank housing and the cylindrical member are co-axial.

11. The impact tool as defined in claim 1 , wherein the first part of the barrel part is co-axial with the cylindrical member and the front spring.

12. An impact tool, comprising:
a motor;
a driving mechanism configured to linearly drive a tool accessory along a driving axis by power of the motor, the driving axis defining a front-rear direction of the impact tool;
a housing that houses the motor and the driving mechanism; and
at least one dynamic vibration reducer, each of the at least one dynamic vibration reducer including a weight, at least one spring and a housing part, the weight being linearly movable in the front-rear direction, the at least one spring being at least either in front of or behind the weight, the weight and the at least one spring being housed in the housing part, wherein:
the driving mechanism includes:
a crank shaft configured to rotate by power of the motor;
a cylinder extending along the driving axis in the front-rear direction; and
a piston configured to reciprocate along the driving axis within the cylinder in response to rotation of the crank shaft;

the housing includes:
a motor housing that houses the motor;
a crank housing that houses the crank shaft; and
a barrel part that (i) is in front of the crank housing and (2) houses the cylinder;

a first part of the barrel part that is integral with a remainder of the barrel part is a portion of the housing part;
a first part of the crank housing that is integral with a remainder of the crank housing is another portion of the housing part;
the housing part includes a cylindrical member that extends in the front-rear direction and that houses at least a portion of the weight;
the first part of the barrel part and the first part of the crank housing are spaced in the front-rear direction and support the cylindrical member;
the cylindrical member is a cylinder having an open front end and a closed rear end;
the first part of the barrel part has a recess that opens rearwards;
the first part of the crank housing (i) has a cylindrical shape and (ii) is rearward of the first part of the barrel part; and
the cylindrical member is supported such that a front end portion of the cylindrical member is in the recess of the first part of the barrel part and another portion of the cylindrical member that is rearward of the front end portion is in the first part of the crank housing.

13. The impact tool as defined in claim 12 , wherein:
the at least one spring includes a front spring in front of the weight and a rear spring behind the weight;
a front end of the front spring is received by a bottom of the recess of the first part of the barrel part; and
a rear end of the rear spring is received by the closed rear end of the cylindrical member.

Assignees

• Makita Corp

Inventors

• Furusawa Masanori
• Hirono Kanako
• Watanabe Kei

Classifications

• B25D17/043 Primary

  Handles resiliently mounted relative to the hammer housing (B25D17/046 takes precedence) · CPC title

• B25D11/12

  comprising a crank mechanism · CPC title

• B25D17/24

  Damping the reaction force {(resiliently mounted handles B25D17/043; dampers in connections of hammers to backhoes E02F3/966)} · CPC title

• B25D17/20

  Devices for cleaning or cooling tool or work · CPC title

• B25D2211/068

  Crank-actuated impulse-driving mechanisms · CPC title