JPH1133934A - Housing for electric tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the cooling efficiency by forming a first air window in which ribs and slits are alternately appeared in a wall of a housing, and integrally forming a second air window in which ribs and slits are alternately appeared so as to be separately moved from the movement of the ribs and the slits of the first air window, inside the housing. SOLUTION: Slits 11 of a first air window are formed in parallel with a rear end wall 3a of a housing 3. Square-bar-like ribs 10, which respectively have the nearly same vertical width with a vertical width of the slit 11, are extended. A second air window is provided with a space from the first air window at the nearly same degree of dimension with thickness of the housing 3. Structure of ribs 12 and slits 13 of the second air window is formed into the nearly similar structure with the first air window, and integrally formed with the housing 3 at the time of forming the housing 3. The ribs 10 and the slits 11 of the first air window and the ribs 12 and the slits 13 of the second air window are arranged each other. With this structure, since the ribs 10, 12 are arranged each other, cooling air can be flowed into the housing 3 without receiving a large resistance.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a cooling air intake of a housing of a power tool.

[0002]

2. Description of the Related Art A housing for a power tool is provided with a cooling air intake for cooling an electric motor inside the housing.

[0003] The housing of the electric power tool disclosed in Japanese Utility Model Laid-Open Publication No. 40258/1988 has a housing body having a number of slits formed thereon, and a cover having the same slits formed thereon with a small gap from these slits. The cover is fixed to the housing body with screws. The rib between the slits of the cover covers the slit of the housing main body from above so that the inside of the housing main body cannot be seen through the slit.

The housing of the power tool disclosed in Japanese Utility Model Laid-Open No. 1-79581 also covers a number of slits in the housing body with a cover having slits formed therein. The slit on the cover side is formed in a tunnel shape bent in the penetrating direction so that the inside of the housing cannot be seen from outside the cover.

[0005] A cooling air intake 1 as shown in FIG. 5 is also conventionally used. The cooling air inlet 1 is formed in a door shape in which a number of armor plates 2 are arranged side by side.

[0006]

[Problems to be Solved by the Invention]
The cooling air intake of the Japanese Patent No. -40258 and Japanese Utility Model Laid-Open No. 1-79581 is constituted by fixing a cover made separately from the housing main body to the housing main body with fixing screws. There is a problem that increases. Further, the fixing screw may be loosened due to the vibration generated in the power tool, and the cover may fall off the housing.

The cooling air intake of the housing shown in Japanese Utility Model Laid-Open Publication No. 64-40258 and Japanese Utility Model Application Laid-Open No. 1-79581, and FIG. Since it is narrow and bent, there is a problem that the flow rate of the cooling air is small and the cooling efficiency is reduced.

[0008]

In order to solve the above-mentioned problems, the present invention provides a power tool having a rib on a wall of a housing.
A first wind window in which 0 and slit 11 appear alternately is formed, and ribs 12 and slits 13 are alternately arranged inside the housing 3 so as to be slightly separated from the first wind window and to be offset from the ribs 10 and slits 11. The appearing second wind window employs the housing of the power tool integrally formed with the housing 3.

The ribs 10, 12 of the first and second wind windows are provided with curved chamfers 10a, 12a as required. By the curved chamfers 10a and 12a, the cooling air flows more smoothly, and the cooling efficiency is increased.

[0010] The first and second wind windows are provided, for example, in the housing 3.
At the rear end wall 3a, the side wall, the upper wall, the lower wall, and the like.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, the electric power tool includes an electric motor 4 in a housing 3 and a fan 5 that rotates integrally with a rotor of the electric motor 4. When the electric motor 4 is started, the fan 5 rotates, and the fan 5 generates cooling air. The cooling air cools the electric motor 4 while flowing around the electric motor 4, and flows out again into the atmosphere.

In this electric power tool, the electric motor 4 is connected to the housing 3
And has an output shaft 6 at the front of the housing 3,
Since the grip 7 is provided below the housing 3, the cooling air intake 8 is connected to the rear end wall 3 a of the housing 3.
Have. Further, the housing 3 has an exhaust port 9 near the fan 5 at the front. The exhaust port 9 can have the same configuration as the cooling air intake port 8. When the fan 5 rotates at the same time as the rotation of the motor 4, the cooling air is taken into the housing 3 in the direction of arrow A from the cooling air intake 8 of the rear end wall 3 a of the housing, contacts the motor 4 and the like, and then flows out of the exhaust 9. It is discharged out of the housing 3 in the direction of arrow B.

The cooling air intake 8 is configured as shown in FIGS. 2, 3 and 4. That is, a first wind window in which ribs 10 and slits 11 alternately appear is formed in a rear end wall 3a of the housing 3 of the power tool.
A second wind window, which is slightly separated from the first wind window and in which ribs 12 and slits 13 alternately intersect with the ribs 10 and slits 11, is integrally formed with the housing 3.

A plurality of slits 11 of the first wind window are formed in the rear end wall 3a of the housing 3 in parallel in the left-right direction. Further, the ribs 10 between the slits 11 extend in the left-right direction in the shape of a rectangular bar with a vertical width substantially equal to the vertical width of the slit 11.

The second wind window is provided with a gap of the same size as the thickness of the housing 3 from the first wind window. The configuration of the rib 12 and the slit 13 of the second wind window is substantially the same as the configuration of the rib 10 and the slit 11 of the first wind window, and is integrally formed together with the first wind window when the housing 3 is formed. The housing 3 is made by injection molding using, for example, a metal or a synthetic resin as a raw material, and the cooling air intake 8 is formed simultaneously with the injection molding.

The ribs 10 and slits 11 of the first wind window and the ribs 12 and slits 13 of the second wind window have substantially the same size and shape as shown in FIG. They are staggered. For this reason, it is difficult for the second wind window to obstruct the inside of the housing 3 from the first wind window. Further, since the ribs 10 and 12 are arranged in a zigzag manner along the inflow direction of the cooling air, the cooling air flows into the housing 3 without receiving much resistance.

The ribs 10 and 1 of the first and second wind windows are provided.
2, a curved chamfer 10 as shown in FIG.
a and 12a are given. This reduces the resistance of the cooling air received by the ribs 10 and 12.

[0019]

According to the present invention, a first wind window in which ribs and slits alternately appear is formed on a wall of a housing of a power tool, and the ribs and slits are slightly separated from the first wind window inside the housing. Since the second wind window, in which ribs and slits alternately appear to be staggered, is integrally formed with the housing, the number of parts, assembly steps, weight, etc. are reduced as compared with the conventional case where the cover wind window is superimposed on the housing wind window. Also, there is no possibility that the cover will fall off due to vibration. Further, since the ribs of the second wind window face the slits of the first wind window and the slits of the second wind window face the ribs of the first wind window, the cooling air does not receive a large resistance. The motor is smoothly taken into the housing, and therefore, the cooling efficiency of the electric motor is improved.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a power tool having a cooling air intake according to the present invention.

FIG. 2 is a rear view showing a location of a cooling air intake;

FIG. 3 is a sectional view taken along line III-III in FIG. 2;

FIG. 4 is a sectional view taken along line IV-IV in FIG. 3;

FIG. 5 is a sectional view similar to FIG. 3, showing a conventional cooling air intake;

[Explanation of symbols]

 3 ... Housing 10 ... Rib 11 ... Slit 12 ... Rib 13 ... Slit

Claims (1)

[Claims] 1. A first air window in which ribs and slits alternately appear on a wall of a housing of a power tool. The first air window is slightly separated from the first air window inside the housing so as to be offset from the ribs and slits. A second wind window in which ribs and slits alternately appear on the housing and are integrally formed with the housing.