WO2020175006A1

WO2020175006A1 - Electric work machine and method for forming housing thereof

Info

Publication number: WO2020175006A1
Application number: PCT/JP2020/003662
Authority: WO
Inventors: 康平脇田
Original assignee: 工機ホールディングス株式会社
Priority date: 2019-02-26
Filing date: 2020-01-31
Publication date: 2020-09-03

Abstract

The present invention prevents entry of foreign matter into a housing while keeping durability around a vent provided in the housing. An electric work machine is provided with a housing (10) that has an integral cylindrical shape and stores a motor inside the housing; a vent (11) that is provided in a predetermined outer surface of the housing and communicates the inside and outside of the housing; and a plurality of ribs provided in the vent (11). The plurality of ribs include an outer rib (12) and an inner rib (13) at different locations in a penetration direction penetrating the inside and outside of the housing. The outer rib (12) and the inner rib (13) are arranged not to overlap with each other in the penetration direction when viewed from the predetermined outer surface.

Description

\¥0 2020/175006 1 卩 (: 17 2020 /003662 Clarification

Title of invention: Electric working machine and method for molding housing thereof

Technical field

The present invention relates to an electric working machine in which a motor is built in a housing and a method for molding the housing.

Background technology

[0002] Generally, in an electric tool or the like in which a motor is built in a housing as shown in Patent Document 1 below, the housing is provided with a vent hole serving as a wind window for cooling the motor. It was desired to prevent foreign matter such as dust and water droplets from entering through the mouth.

[0003] In the case where the housing of the electric working machine has a structure in which the housing is divided into two parts on the left and right sides, the direction of extraction of the cavity part of the divided molding die and the core part fitted therein is opposite to each other. Therefore, in the case of providing a rib on the vent hole in consideration of dustproofness, by arranging the rib almost perpendicular to the extraction direction of the core part, the distance restricted by the draft angle is short and the desired vent shape Was possible.

[0004] However, when molding a housing having a tubular shape in which the withdrawal direction differs by 90 degrees between the cavity portion and the core portion, if the rib of the vent hole is arranged perpendicularly to the withdrawal direction of the cavity portion, the core portion Since it is parallel to the pulling direction, the distance subject to the draft angle becomes longer, the rib becomes too thin, or the opening on the outer surface of the vent becomes wider, and the dustproof property is impaired. This is illustrated in the comparative example in Figure 14 below.

[0005] Fig. 14 (8) to (M) show the ventilation holes 2 of the housing 200 to enhance the dustproof property.

This is a schematic comparative example of a method of forming an electric working machine having a labyrinth structure by providing an outer rib 20 2 and an inner rib 20 3 on 0 1 and a method of molding the housing 20 0, where (8) is the housing 20 0 and a plan sectional view showing the molding die, the housing is an 8-8 sectional view of (Mitsumi)}, and (Mimi) is a ventilation port provided on the side surface of the housing 2 when viewed from the outside of the housing 200 Side view from the radial view of 0 1, (○) 〇 2020/175006 2 卩 (：171? 2020 /003662

Ha (eight)

A side cross-sectional view, (0) is a cross-sectional view taken along line XX of (8), and (M) is an explanatory view showing the appearance of the housing 200. In this comparative example, the ventilation hole 20 1 is provided on the side surface of the housing 200 0 that has a cylindrical shape and houses the motor, but the outer ribs 20 2 provided on the ventilation hole 20 1 The inner ribs 203 are formed in parallel with the axial direction of the tubular portion 203 of the housing 200. When molding such a housing 200, the first and second cavity parts 3 01 and 30 2 which can be contacted and separated from each other and the first and second cavity parts 3 0 1 and 3 in the joined state are formed. Using a molding die 300 having a core portion 300 that can be fitted into the outer casing 202, and an outer rib 202 provided in the ventilation hole 201 of the housing 200 and an arrangement that does not overlap the outer rib 202. It is considered to mold the inner ribs 203 of the at one time.

[0006] In this case, the first cavity portion 301 and the second cavity portion 302 are reciprocally movable in the vertical direction, and the core portion 303 is reciprocally movable in the X direction orthogonal to the vertical direction, and the three members are joined. In this state, the molding space of the housing 200 is filled with resin for molding (eg injection molding). As shown in Fig. 14 (0), the outer ribs 20 2 provided on the air vents 20 1 have the first and second cavity portions 3 0 1, on both sides of the outer rib 20 2 on the side surface of the housing. 3 0 2 convex part

It is performed by forming slit-shaped openings 205 by means of 302. The inner side ribs 203 provided in the ventilation hole 201 are formed by providing the core portion 303 with a recessed portion 303 which becomes the inner rib 203 inside the side surface of the housing 200. ..

[0007] The die-cutting of the housing 200 of the molded product in which the resin is solidified is performed using the first cavity portion 3

0 1 and the second cavity portion 30 2 are separated from each other by moving the core portion 30 3 in the pull-out direction of the X direction orthogonal to the vertical direction.

[0008] Regarding the outer ribs 202, the first cavity portion 301 and the second cavity portion are

The die is moved by moving 3 02 in the direction of the bird's eye so that they are separated from each other. In order to smoothly perform die cutting, as shown in Fig. 14 (0), the width dimension of the outer rib 202 that is orthogonal to the X direction and the vertical direction is determined by the draft angle so that the outer diameter of the tubular shape of the housing 200 is outside the radial direction. It is getting smaller toward the side.

[0009] On the other hand, regarding the inner ribs 203, the core portion 303 is arranged in the longitudinal direction of the inner ribs 203. 〇 2020/175006 3 卩 (：171? 2020 /003662

Move in the X direction, which is the direction, and perform die cutting. In order to facilitate the die-cutting, as shown in Fig. 14 (○), the widthwise dimension of the inner ribs 203 that are orthogonal to the X-direction and the hull-direction is due to the draft angle. In the (X direction), there is no choice but to decrease in the pulling direction of the core portion 303 (it becomes a tapered shape). Therefore, each slit-shaped opening 205 that is the outer opening of the ventilation hole 201 corresponds to the width of the inner rib 203, as shown in Fig. 14 (º). The opening width is large, and the opening width becomes smaller in the pulling direction of the core portion 303. In this way, since it is necessary to provide a draft along the longitudinal direction of the inner rib 203, the width change of the inner rib 203 due to the draft cannot be ignored, and as shown in Fig. 14 (Mimi). This results in a vent 2 01 with a tapered inner rib 203 and a slit-like opening 205.

Prior art documents

Patent literature

[0010] Patent Document 1: Japanese Patent Laid-Open No. 2 0 1 8 _ 1 8 7 7 0 1

Summary of the invention

Problems to be Solved by the Invention

[001 1] As described above, in the case of the comparative example in which the arrangement of the outer ribs and the inner ribs provided in the ventilation hole that serves as the wind window is not devised, each rib is viewed in the side view of the housing having the tubular shape of the electric working machine. Becomes a slender trapezoidal shape, the width dimension of the slit-shaped opening on the outer surface of the housing becomes large and it becomes impossible to suppress the intrusion of foreign matter, or if the width dimension of the slit-shaped opening is reduced, There was a risk that the ribs would become thin and the strength would decrease.

[0012] The present invention has been made in view of such a situation, and an object thereof is an electric motor capable of suppressing the intrusion of foreign matter into the housing while maintaining the durability around the ventilation port provided in the housing. Another object of the present invention is to provide a method for forming a working machine and its housing.

Means for solving the problem 〇 2020/175006 4 boxes (：171? 2020/003662

A first aspect of the present invention is an electric working machine. The electric working machine has a motor and a single tubular shape, and a housing for housing the motor therein, a ventilation hole provided on a predetermined outer surface of the housing for communicating the inside and outside of the housing, and the ventilation. A plurality of ribs provided in the mouth, wherein the plurality of ribs include a first rib and a second rib that are different in position in a penetrating direction penetrating the inside and the outside of the housing, and the first rib and The second rib is integrally molded so as to have a portion that does not overlap with the predetermined outer surface when viewed in the penetrating direction.

The ventilation port is provided on a side surface of the housing, communicates with the inside and outside of the housing along a radial direction of the tubular shape as the penetration direction, and the first rib and the second rib. It is preferable that the ribs have different positions in the radial direction and do not overlap in the radial direction.

[0015] The longitudinal direction of the second rib may be non-parallel to the axial direction and the radial direction of the tubular shape.

The position of the second rib in the penetrating direction is arranged inside the first rib, and the width of the second rib in the penetrating direction viewed on the predetermined outer surface is the penetrating direction. It is said that the side surface along the longitudinal direction of the second rib is formed so as to be inclined with respect to the penetrating direction so as to become smaller toward the inside.

[0017] It is preferable that the second rib has a widthwise dimension of the predetermined outer surface as viewed in the penetrating direction that is substantially constant in the longitudinal direction.

[0018] A plurality of the first ribs and a plurality of the second ribs are preferably provided.

A second aspect of the present invention is a method for molding a housing of an electric working machine. The method of molding the housing of the electric working machine is such that the first and second cavities that can be brought into contact with and separated from each other and the core that can be fitted into the first and second cavities in the joined state are electrically driven. In the case of forming the molding space of the housing of the working machine, the housing formed by filling the molding space with resin has an integral cylindrical shape and is provided on a predetermined outer surface to communicate the inside and outside of the housing. A vent and a plurality of ribs provided on the vent, wherein the plurality of ribs are 〇 2020/175006 5 卩(: 171-1? 2020/003662

It includes a first rib and a second rib that penetrate the inside and outside of the housing at different positions in the penetrating direction, and the first rib and the second rib do not overlap with each other in the penetrating direction on the predetermined outer surface. The second rib is arranged at a position in the penetrating direction on the inner side of the /ribs from the first rib, and the longitudinal direction of the second rib is the first rib. It is not parallel to the contacting/separating direction of the first and second cavity portions and the fitting direction of the core portion.

[0020] It should be noted that any combination of the above constituent elements and one obtained by converting the expression of the present invention between methods and systems are also effective as an aspect of the present invention.

Effect of the invention

[0021] According to the present invention, it is possible to maintain the durability around the vent hole provided in the housing of the electric working machine, effectively suppress the intrusion of foreign matter into the housing, and improve the dustproof property. You can

Brief description of the drawings

[0022] [Fig. 1] Fig. 1 is a schematic first embodiment of a method for molding an electric working machine and a housing thereof according to the present invention, wherein (8) is a plane cross section showing a housing and a molding die having an integral tubular shape. Figure, The housing is a cross-sectional view of (Mimi) 8_8}, (Mimi) is a side view of the ventilation port provided in the housing as seen from the outside of the housing, and (○) is ( 8) No. 1 _ No. 1 side cross-section, (0) No. (8) No. 2 _ No. 2 side cross-section, (No.) is (8) No. 10 cross-section, () is the appearance of the housing Explanatory drawing to show.

FIG. 2 is a side sectional view of a hammer drill as an electric working machine according to the second embodiment of the present invention.

[FIG. 3] An enlarged side view of a main part having a ventilation hole of a housing in the second embodiment.

[FIG. 4] A main part of the second embodiment, wherein (8) is a half cross-sectional view of FIG. 3 and is a half cross-sectional view showing a molding die together.

[FIG. 5] A main part of the second embodiment, wherein (8) is a 8 2 — 8 2 half cross-sectional view of FIG. 3, and (M) is a 2 — 2 half cross-sectional view showing a molding die together. 〇 2020/175006 6 卩(：171? 2020/003662

Perspective view.

[FIG. 7] A main part of the second embodiment, in which (8) is a sectional view taken along the side of 1-Minami 1 of FIG. 4 (8), and (Mi) is a drawing of FIG. 1 _ Sumi 1 side sectional view.

[FIG. 8] A main part of the second embodiment, in which (8) is a sectional view taken along the line 2-2 in FIG. 4(8), and (()) is also shown in FIG. 2 _ Sumi 2 side sectional view.

[FIG. 9] A main part of the second embodiment, wherein (8) is a cross section taken along the line 10 (10) in FIG. 3, and (M) is a cross section taken along line (3 — 0) in FIG.

FIG. 10 is a left side view showing a third embodiment of the present invention, in which a portion including a handle portion of a housing having an integral tubular shape is divided into two parts.

[Fig. 11] Fig. 11 is an exploded perspective view from the left showing a configuration in which the portion including the handle portion of the cylindrical housing is divided into two.

FIG. 12 is a right side view of the third embodiment, showing a configuration in which a portion including a handle portion of a cylindrical housing is divided into two.

[FIG. 13] An exploded perspective view from the right showing a structure in which a portion including a handle portion of a housing having the same tubular shape is divided into two.

[FIG. 14] A schematic comparative example of a method for molding an electric working machine and its housing, wherein (8) is a horizontal cross-sectional view showing the housing and the molding die, and the housing is a (8)-8 cross-sectional view of (Mimi). }, (M) is a side view of the ventilation port provided in the cylindrical housing as seen from the outside of the housing as viewed from the radial direction, (○) is a cross-sectional view of the (M) side of (8), and (0) is ( (8) Cross-sectional view along line XX, and (M) is an explanatory view showing the appearance of the housing.

MODE FOR CARRYING OUT THE INVENTION

[0023] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. The same or equivalent components, members, treatments, etc. shown in the drawings are denoted by the same reference numerals, and the duplicated description will be omitted as appropriate. Further, the embodiment is not a limitation of the invention but an example, and all the features and combinations thereof described in the embodiment are not necessarily essential to the invention.

[0024] Figs. 1 () to () are molding of an electric working machine and a housing thereof according to the present invention. 〇 2020/175006 7 卩(：171? 2020/003662

1 shows a schematic first embodiment of the method. In the first embodiment, the dust-proof is provided on the side surface of the housing 10 of the electric operating machine that has the cylindrical portion 103 that has the shape of a cylindrical body and that houses the motor inside the cylindrical portion 103. In order to improve the property, an outer rib 12 as a first rib and an inner rib 13 as a second rib are provided to provide a ventilation port 11 having a so-called laplin structure. The vent 11 communicates with the inside and outside of the housing, and functions as a wind window for intake or exhaust of air that cools the motor inside the tubular portion 103.

[0025] As shown in Fig. 1 (eight), the outer ribs 12 and the inner ribs 13 provided in the vent hole 11 have a penetrating direction that penetrates the inside and the outside of the housing 10 (specifically, the cylindrical portion 10). (3 radial direction), the inner rib 13 is arranged inside the outer rib 12 so that the outer rib 1 2 and the inner rib 1 3 do not overlap each other when viewed in the radial direction. .. The outer ribs 12 and the inner ribs 13 are inclined with respect to the axial direction of the tubular portion 103 of the housing 10 (parallel to the X direction which is the moving direction of the core portion 10 3 described later). Are formed (non-parallel).

[0026] When molding such a housing 10, the first and second cavity parts 10 1, 10 2 which can be contacted and separated from each other, and the first and second cavity parts 10 1, which are in a joined state. By using the molding die 100 having the core portion 10 3 which can be fitted into the concave portion formed by 10 2, the outer ribs 12 and the tubular portion 10 provided in the vent hole 11 of the housing 10 are used. The inner rib 13 which is arranged so as not to overlap the outer rib 12 when viewed in the penetration direction of 3 (specifically, in the radial direction) is molded at one time.

[0027] Here, the first cavity portion 10 1 and the second cavity portion 10 2 are capable of reciprocating movement in the vertical direction, the core portion 10 3 is capable of reciprocating in the X direction orthogonal to the vertical direction, and the three members are joined. In this state, fill the molding space of the housing 10 with resin and mold (for example, injection molding). The outer ribs 12 provided on the ventilation holes 11 are, as shown in Fig. 1 (Mimi), located on the sides of the housing on both sides of the outer ribs 1 2 on both sides of the first and second cavity portions 1 0 1, 1 0 2 Convex part of

This is done by forming a rectangular slit-shaped opening 15 shown in Figs. 1 (M) and () by 10 2 3. The inner ribs 13 provided on the vent 11 are located inside the side surface of the housing 10 (cylindrical portion). 〇 2020/175006 8 卩(：171? 2020/003662

(Diameter inside of 103)), the core 1033 is provided with a recess 1033 that will become the inner rib 13. As shown in FIG. 1 (Mimi), the outer ribs 12 and the inner ribs 13 are arranged so that they do not necessarily overlap with each other when viewed in the radial direction of the tubular portion 103. Also inside ribs

It is tilted with respect to the direction, and is not parallel to the contacting/separating direction of the first and second cavity parts 1 0 1 and 1 0 2 (falling direction) and the fitting direction of the core part 10 3 (X direction). It

[0028] The die-molding of the housing 10 of the molded product in which the resin is solidified is performed using the first cavity portion 10

This is done by moving the first and second cavity parts 102 in a direction in which they are separated from each other in the vertical direction, and by moving the core socket 1030 in the removal direction in the X direction orthogonal to the vertical direction.

With respect to the outer ribs 12, the first and second cavity parts 10 1 and 10 2 are moved in a direction in which they are separated from each other in the upward direction, and die-cutting is performed. In order to facilitate the die cutting, as shown in Fig. 1 (Min), the width dimension of the outer ribs 12 that are orthogonal to the X direction and the ridge direction is set so as to face the outer radial direction of the cylindrical shape of the housing 10 due to the draft. It has become smaller (substantially the same as the comparative example in Fig. 14).

On the other hand, with respect to the inner ribs 13, the core portion 103 is moved in the cutting direction in the X direction inclined with respect to the longitudinal direction of the inner ribs 13 to perform die cutting. In this case, the inner rib 13 is provided with a draft for smooth die cutting, but the reference surface 1 3 3 for drafting is the surface exposed to the outside of the housing of the inner rib 13 and the reference surface With 1 3 ₃ as the starting point of the draft, apply the required draft to the side surface 1 3 of the inner rib 1 3 along the longitudinal direction of the reference plane 1 3 ₃ . In other words, since the longitudinal direction of the inner rib 13 is not parallel to the longitudinal direction of the core part 103, the longitudinal direction of the inner rib 13 is as shown in Fig. 1 (○) and (0). As shown in Fig. 1 (Mimi), the width dimension of the inner rib 13 perpendicular to the X and direction is smaller toward the inner side in the radial direction of the tubular shape. As a result, the side surface 1 3 along the longitudinal direction of the reference surface 1 3 3 of the inner rib 13 is formed as an inclined surface. Therefore, when the inner rib 13 is viewed from the radial direction of the cylinder, it is shown in Fig. 1 (○), 〇 2020/175006 9 卩(：171? 2020/003662

As shown in (○), the widthwise dimension of the outer surface (reference surface 1 3 3) of the inner rib 13 which is orthogonal to the X direction and the vertical direction is constant (or substantially constant) along the longitudinal direction of the inner rib 13. It is possible to In other words, the width of the inner rib 13 seen from each slit-shaped opening 15 that is the outer opening of the ventilation hole 11 can be made constant (or approximately constant), as shown in Fig. 1 (Mitsumi) and (). In addition, each slit-shaped opening 15 can be made into an elongated rectangle in consideration of dust resistance.

[0031] According to the present embodiment, the following effects can be obtained.

[0032] (1) A housing 10 having a tubular portion 103, in which a motor is housed, a vent 11 provided on a predetermined outer surface of the housing 10 for communicating the inside and outside of the housing, and a vent. When a plurality of ribs provided in the mouth 11 are provided, the plurality of ribs include an outer rib 12 and an inner rib 13 which penetrate the inside and the outside of the housing and have different positions in the penetration direction, and the outer rib 1 2 The inner rib 13 and the inner rib 13 have a labyrinth structure integrally formed so that they do not overlap with each other on the predetermined outer surface when viewed in the penetration direction. As a result, it is possible to prevent foreign matter such as dust and water droplets from entering through the vent 11 to improve the dustproof property, and to form the outer rib 1 2 and the inner rib 13 separately from each other. The strength can be improved compared with. Since the inner ribs 12 and the outer ribs 13 are arranged so as not to overlap with each other when viewed in the penetrating direction, as shown in Fig. 1 (Mimi), the first or second cavity portion 1 0 1, 1 0 2 and the core portion The outer ribs 12 and the inner ribs 13 can be integrally formed by alternately projecting 10 3 and 10 3 in the penetrating direction.

(2) Since the longitudinal direction of the inner rib 13 is non-parallel to the axial direction and the radial direction of the tubular portion 103, the width of the inner rib 13 on the predetermined outer surface when viewed in the penetrating direction. Is reduced inward in the penetrating direction, and the side surface along the longitudinal direction of the inner rib 13 is an inclined surface, so that it is not necessary to provide a draft at the time of molding in the longitudinal direction of the inner rib 13. As a result, the width of the inner rib 13 as viewed in the radial direction (X, the width dimension in the direction orthogonal to the vertical direction) can be made substantially constant. Therefore, it is possible to secure a sufficient width dimension over the entire length of the inner rib 13 in the longitudinal direction and obtain a required strength. In addition, the slit-shaped openings 15 on both sides of the outer ribs 12 should be 〇 2020/175006 10 卩(：171? 2020/003662

A rectangle with a width slightly larger than the width can be used to improve dust resistance.

(3) The molding die 100 for molding the housing 10 is composed of the first and second cavity parts 1 0 1 and 10 2 and the first and second cavity parts 1 0 in the joined state. This is a structure having a core portion 10 3 which can be fitted into 1 and 10 2, and does not require a special structure. Also, by setting the longitudinal direction of the inner rib 13 to be non-parallel to the contact and separation direction of the first and second cavity parts 10 1 and 10 2 and the fitting direction of the core part 10 3, It is no longer necessary to provide a draft in the longitudinal direction of the inner rib 13. As a result, the width of the inner rib 13 in the radial direction can be made substantially constant.

A second embodiment in which the present invention is applied to a hammer drill as an electric working machine will be described with reference to FIGS. 2 to 9. The hammer drill 1 applies a rotating force and a striking force to a tip tool (not shown) held by the tool holding unit 3 to perform scraping work, drilling work, and scraping work on work materials such as concrete and stone. Crushing work can be performed. The outer shell of the hammer drill 1 is composed of a housing 10 and a gear case 30. The housing 10 is a resin molded body. The gear case 30 is made of metal such as aluminum. A side handle 3 1 is provided on the gear case 30.

[0036] The housing 10 has a tubular portion 103 having an integral tubular shape that serves as a motor housing portion for housing the motor 2 and the like, and a handle portion 10 for gripping by an operator. A trigger switch 5 is provided on the upper end of the handle 10 to allow the operator to instruct the motor 2 to drive or stop. The gear case 30 accommodates a power transmission mechanism 4 that transmits the rotation of the motor 2 and drives (rotates and strikes) the tip tool held by the tool holder 3. Since the structure of the power transmission mechanism 4 is well known, its details are omitted.

[0037] The tubular portion 1 that forms an integral tubular shape in the housing 10

The portion shown in FIG. 3 having the ventilation holes 11 will be described in detail. FIG. 3 is a main part of the second embodiment. As shown in this figure, the vent 11 is a cylinder that is a part for housing the motor 2. 〇 2020/175006 1 1 卩(：171? 2020/003662

A plurality of slit-shaped openings 15 each having a substantially rectangular shape (having a substantially constant width), which are arranged closer to the handle portion 1013 than the shape portion 103, the outer ribs 12 formed between them, and the tube. The shape portion 103 has an inner rib 13 located inside the outer rib 12 in the radial direction. Further, the outer ribs 12 and the inner ribs 13 do not overlap each other when viewed in the radial direction, and the inner ribs 13 are visible from the slit-shaped openings 15. As a result, the vent 11 has a labyrinth structure.

[0038] Fig. 4 (eight) is a 8 1 -8 1 half cross-sectional view of Fig. 3, (m) is an 8 1 _ 8 1 half cross-sectional view showing the molding die together, and Fig. 5 (eight) is the eight 1- 2-8 2 and a half sectional view, (M) shows 8 2 _ 8 2 and a half sectional view together with the molding die

It is a perspective view. As you can see from these figures, the inner ribs

Direction (parallel to the extraction direction (X direction) of the core portion 103) and the moving direction of the first cavity portion 10 1 (and the second cavity portion: not shown in the second embodiment) It is also non-parallel to a certain direction. In addition, a gap 16 is formed between the outer rib 12 and the inner rib 13 located radially inward of the outer rib 12 as an air passage communicating with the slit-shaped opening 15.

[0039] Fig. 7 (eight) is a sectional view taken along the line 1-Min 1 of Fig. 4 (eight), and (Min) is a sectional view showing the forming die together, and is shown in Fig. 4 (8). Fig. 8 (eight) is a sectional view taken along the side of Min 2__Min 2 in Fig. 4(8), and (Min) is a sectional view showing the forming mold together with Fig. 4()

It is a half cross-sectional view, and each inner rib 13 is formed with a draft in a drawing direction of a core part 103 which is parallel to an axial direction of the tubular part 103. That is, since the longitudinal direction of the inner rib 13 is inclined with respect to the axial direction of the tubular portion 103, it is not necessary to form the draft so as to match the longitudinal direction of the inner rib 13. As shown in Fig. 7 (8), (Mimi) and Fig. 8 (8), (Mimi), it is possible to make the width dimension of the inner rib of the cylindrical portion 103 as viewed in the radial direction substantially constant. .. In addition, in FIGS. 9 (8) and (M), which is a cross-sectional view taken along line XX of FIG. 3, the width of the inner rib 13 in the radial direction is the same as that of the radial direction due to the draft. The side surface along the longitudinal direction of the inner rib 13 becomes smaller toward the inner side and is formed as an inclined surface. 〇 2020/175006 12 卩(：171? 2020/003662

The operation and effect of the second embodiment is similar to that of the schematic first embodiment, and is a housing 10 having a tubular portion 10 3 forming an integral tubular shape like a hammer drill 1. The labyrinth structure vent 11 with excellent dust resistance can be manufactured without using a special mold.

[0041] Figs. 10 to 13 show Embodiment 3 in which the present invention is applied to a hammer drill as an electric working machine, in which the outer shell portion of the hammer drill 1 is a tubular portion that forms an integral tubular shape. Although it has a housing 10 having a 10 3 and a gear case 30, the housing 10 has a structure in which a portion including the handle portion 10 is divided into two parts. Fig. 10 is a left side view showing a structure in which the part of the housing 10 including the handle portion 10 is divided into two parts. Fig. 11 is an exploded perspective view of the same from the left side. Fig. 12 is a right side view of the same. Similarly, 13 is an exploded perspective view seen from the right side.

[0042] As shown in these figures, the housing 10 has a tubular portion that forms an integral tubular shape.

A combined structure of a housing part 20 having an integral part of 10 3 and a half of the handle part 10 13 and a housing part 2 1 having a part including the other half of the handle part 10 13 (for example, screwing It is a structure that is integrated with. The outer ribs 12, inner ribs 13, slit-shaped openings 15 and the like provided in the vent hole 11 on one side (right side) of the housing 20 have the same configuration as in the second embodiment described above. It is molded at the same time with the same mold.

The other (left) vent 11 is formed on the side of the housing 20 and the outer rib 12 and the slit-shaped opening 15 formed on the housing 21 which is another molded body. It has a labyrinth structure in combination with the inner ribs 13.

[0044] In the case of the third embodiment, since one housing portion 20 integrally has a tubular portion 1033 for accommodating a motor and half of the handle portion 10 s, the strength of the handle 10 s Can be increased.

Although the present invention has been described with reference to the exemplary embodiments, it will be understood by those skilled in the art that various modifications can be made to each constituent element and each processing process of the exemplary embodiments within the scope of the claims. Is understood by. The modified examples will be described below.

[0046] In the second and third embodiments of the present invention, the hammer drill is exemplified as the electric working machine. 〇 2020/175006 13 卩(：171? 2020/003662

It can be applied to housings that have an integral tubular shape, such as grinders, dust collectors, and mowers.

Explanation of symbols

[0047] 1 electric working machine, 2 motor, 3 tool holder, 4 power transmission mechanism, 10,

200 Housing, 1 03, 2003 Cylindrical part, 101^" Handle, 1 1, 201 Vent, 1 2, 202 Outer rib, 1 3, 203 Inner rib, 1 5, 205 Slit-like opening, 1 01, 301 1st section, 1 02, 302 2nd section 1 1 03, 303 Core section 6

Claims

\¥0 2020/175006 14 ?01/^2020/003662 Claims

[Claim 1] A motor,

A housing having an integral tubular shape and containing the motor therein; and a vent hole provided on a predetermined outer surface of the housing for communicating the inside and outside of the housing,

A plurality of ribs provided in the vent,

The plurality of ribs include a first rib and a second rib that penetrate the inside and the outside of the housing and have different positions in the penetrating direction, and the first rib and the second rib are formed on the predetermined outer surface. An electric working machine integrally molded so as to have non-overlapping portions when viewed in the penetration direction.

[Claim 2] The ventilation port is provided on a side surface of the housing, and communicates the inside/outside of the casing along the radial direction of the tubular shape as the penetration direction, and the first rib and the first rib. The electric working machine according to claim 1, wherein the second ribs are arranged at different positions in the radial direction and do not overlap each other when viewed in the radial direction.

3. The electric working machine according to claim 1, wherein a longitudinal direction of the second rib is nonparallel to the axial direction and the radial direction of the tubular shape.

4. The second rib is arranged at a position in the penetrating direction inside the first rib, and the width of the second rib in the penetrating direction on the predetermined outer surface is 4. The side surface along the longitudinal direction of the second rib is formed to be inclined with respect to the penetrating direction so as to become smaller toward the inner side in the penetrating direction. Electric operation machine described.

5. The electric operating machine according to claim 4, wherein the second rib has a dimension in the width direction in the penetration direction on the predetermined outer surface that is substantially constant in the longitudinal direction.

[Claim 6] The plurality of first ribs and the plurality of second ribs are respectively provided. 〇 2020/175006 15 卩(：171? 2020/003662

The electric working machine according to any one of claims 1 to 5.

[Claim 7] A molding space for a housing of an electric working machine, comprising: first and second cavity portions that can be brought into and out of contact with each other; and a core portion that can be fitted into the first and second cavity portions in a joined state. A method of molding a housing of an electric working machine, which comprises:

The housing, which is formed by filling the molding space with resin, has an integral tubular shape, and has a ventilation port provided on a predetermined outer surface for communicating the inside and outside of the housing, and a plurality of ribs provided on the ventilation port. Has, \

The plurality of ribs include a first rib and a second rib that penetrate the inside and the outside of the housing and have different positions in the penetrating direction, and the first rib and the second rib are formed on the predetermined outer surface. The arrangement has non-overlapping parts when viewed in the penetration direction,

The position of the second rib in the penetrating direction is arranged inside the housing with respect to the first rib, and the longitudinal direction of the second rib is the contacting/separating direction of the first and second cavities. And a method of molding a housing of an electric working machine, which is non-parallel to the fitting direction of the core portion.