JPS6348373Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to the structure of a power tool that allows convenient attachment and detachment of the tool.

Some power tools, such as disk grinders and polishers, are configured to be attached to and detached from the output shaft of an electric motor that has been decelerated.

In this case, the tool is screwed onto the output shaft, or the parts that fix the tool to the output shaft are configured to be attached and detached using screwing means, and in most cases, the output shaft must be fixed so that it does not rotate in order to attach or detach the tool. No.

Conventionally, the main body and the tool have been constructed so that another tool such as a spanner can be inserted thereinto, and the rotation of the output shaft has been locked using the spanner or the like to attach and detach the tool.

However, with this method, the output shaft must be machined so that a spanner can be applied to it, and the need to create a gap between the tool and the main body tends to make the power tool larger. It was necessary to support the main body, the wrench, and the tool in three places, and in fact, the structure did not allow for easy tool replacement.

In addition, attempts have been made to provide a through-hole in the rotating part and insert a pin, etc. into the through-hole to restrict rotation and attach/detach the tool, but the fitting position of the through-hole and the pin is difficult. This also had the disadvantage of being troublesome in practical terms.

It is an object of the present invention to provide a power tool in which the output shaft can be restrained very conveniently when the tool is attached to and removed from the output shaft, and the work can be easily performed.

The present invention will be explained below based on an embodiment shown in the drawings. Fig. 1 is a longitudinal cross-sectional view of the main part showing an embodiment of the power tool according to the invention, and Fig. 2 is a main part thereof. FIG. 3 is a longitudinal sectional view of the main part showing the state of its operation.

In FIG. 1, the power tool includes a motor 1 equipped with a speed reducer 4 made up of gears 2 and 3, an output shaft 5 extending from the speed reducer 4 having a step 6 formed therein, and a nut for clamping a tool 7. 8 and 9 are installed.

A case 10 that accommodates the gears 2 and 3 is provided with a protrusion 11 having the same module as the gear 3 in the radial direction of the gear 3 so as to be movable up and down.
is provided.

In FIG. 2, the protrusion 11 is the protrusion portion 13
is formed to mesh with the gear 3, and is formed to be long so as to support the protruding portion 13, and both ends are supported by the case 10.

The protrusion 11 is made of a spring plate made of resin or steel, and due to its elasticity, the protrusion 11 does not mesh with the gear 3 but is separated from the gear 3.

In FIG. 3, the protrusion 11 is configured such that when a button 12 is strongly pressed from outside the case 10, the gear 3 and the protrusion 13 are fitted and engaged against elasticity.

In such a configuration, the gear 3 and the protrusion 11 do not come into contact with each other unless the button 12 is pressed, and the rotation of the electric motor 1 is transmitted to the output shaft 6 via the gears 2 and 3. 7 is rotated.

When the tool 7 is to be attached or detached for replacement or the like, the button 12 is pressed to engage the protrusion 11 and the gear 3.

In this case, both ends of the protrusion 11 are supported by the case 10, and the protrusion 11 does not move even if it meshes with the gear 3, so that rotation of the gear 3 is restricted.

Therefore, if the rotation of the gear 3 is restrained by pressing the button 12 in this way, the output shaft 6 will not rotate, and the nuts 8 and 9 screwed onto the output shaft 6 will not rotate.
can be easily attached and detached, making it easy to replace tools.

Moreover, the meshing is from the radial direction of gear 3,
By pressing the button 12, the gear 3 and the protrusion 11 will fit into each other at an arbitrary position, which is extremely convenient.

In addition, if the button 12 is exposed to the outside of the case 10, it is possible to press the button 12 while pressing the case 10.
Since the tool 7 can be gripped easily, tasks such as replacing the tool 7 can be easily performed.

Furthermore, when this button 12 is provided at a desired position in terms of design, the gear 3 can be provided at any position on the radially outer circumferential side of the button 12 except for the part that becomes an obstacle to the gear 2, and can be used in various power tools. It is possible to configure a functional power tool by taking into account the convenience of work and the convenience of other gears and functional parts. In addition, unlike conventional pins, the protrusions 11 come into contact with the teeth of the gear 3 at several points facing each other in the rotational direction at the same time, which reduces the generation of radial reaction force exerted by torque. A different effect can be obtained than when restraining with a single pin. moreover,
Since it has the same module as the gear, damage to the gear 3 is reduced, and an effect such as an increase in noise due to damage to the gear 3 can be prevented.

The protrusion 11 does not necessarily need to be formed integrally with the protrusion portion 13 and the support portion;
It is also possible to form the spring separately from a steel material and attach it to a plate-shaped spring or resin.

Further, if the case 10 is formed as in the embodiment shown in FIG. 2, it is easy to remove the case 10 from the mold, and the structure is simple.

As explained above, according to the present invention, since the rotation of the gear is restricted by pushing it with a protrusion from the radial direction, it is possible to easily restrict the rotation of the output shaft and replace the tool, which has great practical value. be.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view of a main part of a power tool showing an embodiment of the present invention. FIGS. 2 and 3 are longitudinal sectional views of the main parts thereof. 2, 3...gear, 7...tool, 10...case, 11...protrusion, 12...button.

Claims (1)

[Scope of utility model registration request] In an electric tool that is provided with a gear in an electric motor to reduce the speed and to attach a tool, a plurality of protrusions formed on the same module as the gear are configured to fit from the radial direction of the gear, and the protrusions are elastically separated. A power tool characterized in that the power tool is configured to be fitted into the gear and to be fitted into the gear by an external force.