Clockwise and counterclockwise rotation switching device for power tool

A technology of electric tools and switching devices, which is applied in the direction of electromechanical devices, portable motorized devices, manufacturing tools, etc., can solve the problems of contact pressure reduction, achieve the effects of improving contact life, suppressing vibration and welding, and avoiding cost increases

Inactive Publication Date: 2011-09-14
MAKITA CORP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, if it is used near the upper limit of the elastic range in order to increase the abutment pressure, the elastic end 4a will be plastically deformed due to the influence of heat and vibration, resulting in a decrease in the abutment pressure, causing chattering (chattering) of the elastic end 4a. ) or deposited

Method used

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  • Clockwise and counterclockwise rotation switching device for power tool
  • Clockwise and counterclockwise rotation switching device for power tool
  • Clockwise and counterclockwise rotation switching device for power tool

Examples

Experimental program
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Effect test

no. 1 approach

[0024] Figure 1A and Figure 1B It is an explanatory diagram of the component base (the state in which the fixed contact is not attached) 2a used in the forward and reverse switching device of the present invention, Figure 1A represents a stereogram, Figure 1B Indicates a partial enlarged view. Figure 2A and Figure 2B It is an explanatory diagram of the member base 2a in the state where the fixed contact is attached, Figure 2A for a top view, Figure 2B Enlarged image of Part A. In this member base 2a, a pair of fixed contacts 4 and 4 having a point-symmetric plane arc-shaped main structure and the Image 6 , Figure 7 , Figure 8A and Figure 8B The member base 2 described in the above is the same, but on the bottom plate 13 of the member base 2a of the present invention, an L-shaped restriction portion in plan view is integrally protruded on the outer peripheral side of each elastic end 4a of the fixed contact 4 The limiting protrusion 14. When the movable co...

no. 2 approach

[0028] Figure 3A and Figure 3B It is also an explanatory diagram of the member base 2b in a state where the fixed contact is not attached, Figure 3A represents a stereogram, Figure 3BIndicates a partial enlarged view. In this member base 2b, a through hole 15 is provided at the front end position of the restricting projection 14 on the bottom plate 13, and the front end of the restricting projection 14 is provided with elasticity.

[0029] Therefore, by the forward / reverse switching device, the brush base 3 is rotated to the forward rotation position, the movable contact 11 is brought into contact with the elastic end 4a of the fixed contact 4, and the elastic end 4a is flexibly deformed to the outer peripheral side to contact the restricting protrusion 14 abutment, at this time, as Figure 4 As shown, the lower end of the restricting protrusion 14 is flexibly deformed to the outer peripheral side due to its elasticity, and pushes the elastic end 4a toward the movable ...

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PUM

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Abstract

The invention provides a clockwise and counterclockwise rotation switching device of a power tool capable of effectively suppressing chattering or fusing of an elastic end to improve contact durability. An end part of a fixed contact 4 is formed to be an elastic end 14 deformed by contacting to a movable contact 11. A unit base 2a includes a regulation projection 14 which is abutted with the elastic end 4a, which is deformed in contact with the movable contact 11, so as to regulate the deformation quantity.

Description

technical field [0001] The present invention relates to a forward-reverse switching device provided in a motor-driven electric power tool for switching the rotation direction of the motor. Background technique [0002] The forward and reverse switching device of the electric tool includes a component base and an annular brush base, the component base is fixed on the stator of the motor in the housing, and has a pair of fixed contacts electrically connected with the stator coil respectively, so The brush base is rotatably mounted on the component base, and holds a pair of carbon brushes opposed to the commutator and in sliding contact. moving contact. By rotating the brush base, the contact state of the two movable contacts to the fixed contact is switched, whereby forward rotation and reverse rotation of the motor can be selected (for example, refer to Patent Document 1). [0003] Image 6 is an exploded perspective view showing a specific example of the forward-reverse sw...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): B25F5/00H01H1/50H01H3/16
CPCH02K5/148H02K23/18H02K23/66H01H9/063
Inventor 吉川修二
Owner MAKITA CORP
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