Work machine

Abstract

To provide a work machine that can exert high cooling performance.SOLUTION: A shielding part 40 provided in a rear-side insulator 26 of a motor 20 functions as a fan guide part that suppresses air passing through a fan 34 from flowing into a space between an outer periphery part of a stator and an inner periphery part of a motor storage part 11. The shielding part 40 is positioned closer to outside than a stator coil 24 in a radial direction, in the rear-side insulator 26, which protrudes from a portion positioned between a stator core 23 and the fan 34 to the outside in the radial direction, and extends in a circumferential direction of the motor 20. The shielding part 40 constitutes a single member together with the rear-side insulator 26 and can be separated from the rear-side insulator 26.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a work machine. [Background technology]

[0002] Patent Document 1 discloses a work machine having a fan for cooling a motor and a board. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-000959 A Summary of the Invention [Problem to be solved by the invention]

[0004] If the airflow discharged by the fan does not flow to the exhaust port but flows back into the intake side of the fan, the fan's air-blowing efficiency deteriorates and cooling performance drops.

[0005] An object of the present invention is to provide a work machine with high cooling performance. [Means for solving the problem]

[0006] One aspect of the present invention is a work machine. a motor including a rotor, a stator including a stator core wound with a coil around an outer periphery of the rotor, and an insulator insulating the stator core from the coil; a fan located on one side of the insulator in the axial direction of the motor and rotating integrally with the rotor; a housing that houses the motor and the fan, the housing having an air intake and an exhaust port located on an outer periphery side of the fan; A work machine comprising: an air flow passage is formed from the intake port through the inside of the stator and the fan to the exhaust port; The present invention is characterized in that a shielding portion that prevents the air that has passed through the fan from entering the space between the outer periphery of the stator and the inner periphery of the housing is a single member together with the insulator.

[0007] Another aspect of the present invention is a work machine. a motor including an output shaft, a rotor core that rotates integrally with the output shaft, a stator core that faces the rotor core and has a coil wound therearound, and an insulator that is connected to the stator core and insulates the stator core from the coil; A fan that rotates integrally with the output shaft; a housing having the motor and the fan; A work machine comprising: The present invention is characterized in that a shielding portion of the insulator that is located radially outward from the coil in the motor direction and between the stator core and the fan, protrudes radially outward from the coil, and extends circumferentially of the motor, forms a single member with the insulator.

[0008] The present invention may be expressed as an "electric operating machine", "electric tool", "electrical equipment", etc., and such expressions are also valid as aspects of the present invention. Effect of the Invention

[0009] According to the present invention, a work machine with high cooling properties can be provided. [Brief description of the drawings]

[0010] [Figure 1] 1 is a perspective view of a working machine 1 according to a first embodiment of the present invention. [Diagram 2] FIG. [Diagram 3] FIG. [Figure 4] FIG. 4 is an enlarged view of the main part of FIG. [Diagram 5] FIG. 5 is an enlarged view of a main part of FIG. 4, also showing the flow of air currents. [Figure 6]FIG. [Figure 7] 2 is a perspective view of the work machine 1 from the rear with the tail cover 14 and the fan 34 removed. FIG. [Figure 8] FIG. 2 is a rear view of the work machine 1 with the tail cover 14 and the fan 34 removed. [Figure 9] FIG. 2 is a perspective view of the stator assembly of the working machine 1 as viewed from the rear. [Figure 10] FIG. 4 is an enlarged cross-sectional view of a main portion of a work machine according to a comparative example. [Figure 11] FIG. 11 is a perspective view of a working machine according to a second embodiment of the present invention, seen from the rear with a tail cover removed. [Figure 12] FIG. 12 is a rear view of the working machine in the same state as in FIG. 11 . [Figure 13] FIG. 7 is a cross-sectional view of a main portion of a work machine according to a third embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] (Embodiment 1) 1 to 9 relate to a work machine 1 according to a first embodiment of the present invention. The work machine 1 is an impact driver. FIGS. 1 to 3 and 6 define the mutually orthogonal front-rear, up-down, and left-right directions of the work machine 1. FIG. 1 shows the work machine 1 in a state where a battery pack 17 is attached, and FIGS. 2 and 3 show the work machine 1 in a state where the battery pack 17 is not attached.

[0012] The working machine 1 has a housing 10. The housing 10 is, for example, a resin molded body having a structure divided into left and right parts. The housing 10 includes a motor accommodating section 11, a handle section 12, and a battery pack mounting section 13.

[0013] The motor housing 11 is a cylindrical part whose central axis is approximately parallel to the front-rear direction. The upper end of the handle part 12 is connected to a middle part of the motor housing part 11 in the front-rear direction and extends downward from the middle part. The battery pack attachment part 13 is provided at the lower end of the handle part 12, and a battery pack 17 can be detachably attached thereto. The work machine 1 operates using power from the battery pack 17.

[0014] The work machine 1 has a tail cover 14 that is connected to an opening on the rear side of the motor housing part 11 and covers the opening. The tail cover 14 is fixed to the motor housing part 11 by a screw (not shown). Note that the work machine 1 may be of a type that does not have the tail cover 14.

[0015] The work machine 1 has a hammer case 18 connected to the front part of the motor accommodating portion 11. The hammer case 18 is made of, for example, metal, and is held in the motor accommodating portion 11 and extends forward from the motor accommodating portion 11.

[0016] The work machine 1 has a trigger switch 15 at the upper end of the handle portion 12, which allows the user to switch between driving and stopping the motor 20. The work machine 1 has a forward / reverse switch 16, which allows the user to switch between forward and reverse rotation of the motor 20, near the boundary between the motor housing portion 11 and the handle portion 12. The work machine 1 has a first control board 35 inside the battery pack attachment portion 13. The first control board 35 is equipped with a control unit such as a microcomputer that controls the driving of the motor 20.

[0017] The work machine 1 has a motor 20, a reduction mechanism 28, a spindle 29, a rotary impact mechanism 30, and a fan 34 inside the motor housing portion 11 and the hammer case 18.

[0018] The motor 20 is an inner rotor type brushless motor, and includes a motor shaft 21 as an output shaft, a rotor 22, a stator core 23, a stator coil 24, a front insulator 25, and a rear insulator .

[0019] The motor shaft 21 is parallel to the front-rear direction. That is, the axial direction of the motor 20 (hereinafter "axial direction") is parallel to the front-rear direction. The radial direction of the motor 20 (hereinafter "radial direction") is the radial direction centered on the motor shaft 21. The circumferential direction of the motor 20 (hereinafter "circumferential direction") is the direction around the axis centered on the motor shaft 21.

[0020] The rotor 22 is provided around the motor shaft 21 and rotates integrally with the motor shaft 21. As shown in Figures 7 and 8, the rotor 22 includes a rotor core 22a and a rotor magnet 22b. The stator core 23, the stator coil 24, the front insulator 25, and the rear insulator 26 form a stator of the work machine 1. The stator set shown in Figure 9 is a stator plus a second control board 36 described below.

[0021] The stator core 23 is provided on the outer periphery of the rotor 22 and faces the rotor 22. The stator coil 24 is provided (wound) on the stator core 23. The front insulator 25 is provided (connected) to the front part of the stator core 23. The rear insulator 26 is provided (connected) to the rear part of the stator core 23. The front insulator 25 and the rear insulator 26 are, for example, resin molded bodies, and are interposed between the stator core 23 and the stator coil 24 to insulate the stator core 23 and the stator coil 24 from each other.

[0022] A second control board 36 is attached to the front of the front insulator 25. The second control board 36 is equipped with a magnetic sensor such as a Hall IC for detecting the rotational position of the motor 20, and a switching element (inverter circuit) for supplying a drive current to the stator coil 24.

[0023] The speed reducing mechanism 28 reduces the rotation of the motor 20 and transmits the rotation to the spindle 29. The spindle 29 drives the rotary impact mechanism 30. The rotary impact mechanism 30 is an output part of the work machine 1 and is driven by the motor 20.

[0024] The rotary impact mechanism 30 includes a spring 31, a hammer 32, and an anvil 33. A tool tip such as a bit (not shown) is held in a tool tip attachment hole 39 provided at the tip of the anvil 33. The hammer 32 is cam-engaged with the spindle 29, and is urged forward by the spring 31. The hammer 32 driven by the spindle 29 rotary-impacts the anvil 33. The configuration and operation of the rotary impact mechanism 30 are well known, so further detailed description will be omitted.

[0025] The fan 34 is attached to the motor shaft 21 behind the rotor 22 and behind the rear insulator 26, rotates integrally with the motor shaft 21 and rotor 22, and generates cooling air for cooling the motor 20 and the like. The fan 34 is a centrifugal fan that generates airflow in a centrifugal direction. The motor housing 11 has an air intake 37 for taking in the airflow (hereinafter referred to as "cooling air") generated by the fan 34. The tail cover 14 has an exhaust port 38 for exhausting the cooling air. The exhaust port 38 is located on the outer periphery of the fan 34.

[0026] The fan 34 forms airflow passages from the intake port 37 through the inside of the stator and the fan 34 to the exhaust port 38, for example, airflow passages W1, W3, and W4 in Fig. 5, and airflow passages W2, W3, and W4 in Fig. 5. The arrow W1 in Fig. 5 indicates the air flow that flows radially inward in front of the second control board 36 and heads toward the inside of the stator from the central through-hole of the second control board 36. The arrow W2 indicates the air flow that flows radially inward behind the second control board 36 and heads toward the inside of the stator.

[0027] The work machine 1 is characterized in that the rear insulator 26 also functions as a fan guide.

[0028] The rear insulator 26 has a shielding portion 40 (fan guide portion) that prevents the air that has passed through the fan 34 from going into the space between the outer periphery of the stator and the inner periphery of the housing 10 (the inner periphery of the motor accommodating portion 11), i.e., prevents the generation of an air flow as shown by W5 in FIG. 5.

[0029] The shielding portion 40 forms a single member (single molded body) together with the rear insulator 26. That is, the shielding portion 40 forms a part of the single member (single molded body) that constitutes the rear insulator 26. The shielding portion 40 is provided inseparably with the rear insulator 26.

[0030] The shielding portion 40 protrudes radially outward from a portion of the rear insulator 26 that is located radially outside the stator coil 24 and between the stator core 23 and the fan 34, and extends in the circumferential direction of the motor 20. The shielding portion 40 is a flat portion that is approximately perpendicular to the front-to-rear direction, and faces the front of the fan 34 in the front-to-rear direction. The shielding portion 40 is located forward of the exhaust port 38.

[0031] As shown in Figs. 7 to 9, the shielding portions 40 are provided intermittently in the circumferential direction. The portions between the shielding portions 40 adjacent to each other in the circumferential direction are notches, which serve as passages through which the crossover wires 41 pass in the radial direction. The motor accommodating portion 11 has a rib 42 that protrudes inward from the inner periphery of the motor accommodating portion 11 and extends in the circumferential direction. The rib 42 is a flat portion that is approximately perpendicular to the front-rear direction and faces the front part of the fan 34 in the front-rear direction. The range in which the rib 42 exists and the range in which the shielding portions 40 exist in the axial direction at least partially overlap. Preferably, the rear surface of the rib 42 and the rear surface of the shielding portions 40 are on the same plane.

[0032] 5, in the axial direction, the rear end of the shielding portion 40 is at the same position as the rear end of the stator coil 24. In the axial direction, the rear end of the shielding portion 40 may be located closer to the stator core 23 than the rear end of the stator coil 24. In the radial direction, the shielding portion 40 extends to the outside beyond the fan 34.

[0033] The rear insulator 26 guides the crossover wires 41 of the stator coils 24 in the circumferential direction between the stator core 23 and the shielding portion 40. In the radial direction, the shielding portion 40 extends to an outer side than the crossover wires 41. The crossover wires 41 connect the multiple stator coils 24 together.

[0034] This embodiment provides the following advantageous effects.

[0035] (1) The shielding portion 40 provided on the rear insulator 26 functions as a fan guide portion (baffle plate) that prevents the air that has passed through the fan 34 from entering the space between the outer periphery of the stator and the inner periphery of the motor housing portion 11, i.e., prevents the generation of an air flow as shown by W5 in Fig. 5. This suppresses vortexes in the cooling air generated by the fan 34, improving the air blowing efficiency of the fan 34 and thereby improving the cooling performance of the motor 20 and the second control board 36.

[0036] (2) The shielding portion 40 protrudes radially outward from a portion of the rear insulator 26 that is located radially outside the stator coil 24 and between the stator core 23 and the fan 34, and extends in the circumferential direction of the motor 20. This makes it possible to effectively prevent the air that has passed through the fan 34 from entering the space between the outer periphery of the stator and the inner periphery of the motor accommodating portion 11 over a wide circumferential range.

[0037] (3) The shielding portion 40 and the rear insulator 26 form a single member (single molded body) and cannot be separated from the rear insulator 26. Therefore, compared with a configuration in which a member having the function of a fan guide portion is provided separately from the rear insulator 26 (hereinafter referred to as a "separate fan guide configuration"), the number of assembly steps and parts of the stator is reduced, the stator is easy to assemble, and costs are reduced. In addition, in the separate fan guide configuration, there is a risk that the separate fan guide may come into contact with the jumper wire 41 during assembly of the stator, damaging the jumper wire 41 and causing a short circuit between the stator coils 24. However, by providing the shielding portion 40 on the rear insulator 26, such a risk is also reduced. Furthermore, in the separate fan guide configuration, a clearance to avoid contact between the separate fan guide and the jumper wire 41 increases the axial length of the stator, but by providing the shielding portion 40 on the rear insulator 26, unnecessary clearance is eliminated, and an increase in the axial length of the stator can be suppressed. Furthermore, unlike a separate fan guide, the shielding portion 40 integrated with the rear insulator 26 also functions as a guide to prevent the jumper wire 41 from falling off rearward, which is advantageous for mass production. If the risk of the jumper wire 41 falling off is low, the winding tension of the stator coil 24 can be increased to increase the occupancy rate of the stator coil 24 in the winding slots.

[0038] (4) Since the shielding portion 40 extends radially outward beyond the crossover wire 41, the risk of iron powder or other dust particles being carried by the airflow generated by the fan 34 and blowing against the crossover wire 41 or flying directly from the fan 34 and hitting the crossover wire 41, damaging the crossover wire 41 and causing a short circuit between the stator coils 24, is reduced.

[0039] (5) The shielding portions 40 are provided intermittently in the circumferential direction of the motor 20, and the ribs 42 protruding inward from the inner periphery of the motor accommodating portion 11 are located or extend between the shielding portions 40 adjacent to each other in the circumferential direction. This allows the air that has passed through the fan 34 to effectively be prevented from entering the space between the outer periphery of the stator and the inner periphery of the motor accommodating portion 11 while ensuring a passage for the jumper wire 41 to pass in the radial direction. Here, in a configuration in which the ribs 42 are provided all around without providing the shielding portions 40, there is a risk that the ribs 42 may come into contact with the jumper wire 41 during assembly of the housing 10, damaging the jumper wire 41 and causing a short circuit between the stator coils 24. In addition, there is a risk that dust such as iron powder may be blown onto the jumper wire 41 by the airflow generated by the fan 34 through the gap between the ribs 42 and the rear insulator 26, or may fly directly from the fan 34 and hit the jumper wire 41, damaging the jumper wire 41 and causing a short circuit between the stator coils 24. Such a risk can be suitably reduced by providing the shielding portion 40 on the rear insulator 26. Furthermore, unlike the rib 42, the shielding portion 40 integral with the rear insulator 26 also functions as a guide that prevents the jumper wire 41 from falling off rearward, which is advantageous for mass production.

[0040] (6) The range in the axial direction of the ribs 42 and the range in the shielding portion 40 at least partially overlap. Therefore, compared to a case in which the ribs 42 and the shielding portion 40 are spaced apart in the axial direction, the effect of preventing the air that has passed through the fan 34 from entering the space between the outer periphery of the stator and the inner periphery of the motor accommodating portion 11 is enhanced.

[0041] (7) In the axial direction, the rear end of the shielding portion 40 is located at the same position as the rear end of the stator coil 24. Therefore, compared to a case in which the rear end of the shielding portion 40 is located rearward of the rear end of the stator coil 24, an increase in the axial length of the stator due to the provision of the shielding portion 40 can be suppressed.

[0042] (Comparative Example) FIG. 10 is an enlarged cross-sectional view of a main part of a working machine according to a comparative example. In the working machine of the comparative example, the rear insulator 26 of the working machine 1 of the first embodiment is replaced with a rear insulator 826 that does not have a shielding portion 40. In the working machine of the comparative example, since there is no shielding portion 40, the air that has passed through the fan 34 is not prevented from going to the space between the outer periphery of the stator and the inner periphery of the motor housing portion 11, and a vortex is generated near the outer periphery of the fan 34, reducing the air blowing efficiency of the fan 34. In addition, dust such as iron powder carried by the vortex is not prevented from hitting the crossover wire 41, and dust such as iron powder directly flying from the fan 34 is not prevented from hitting the crossover wire 41, so that the crossover wire 41 is damaged, and there is a risk of a short circuit between the stator coils 24. The above-mentioned first embodiment is intended to suitably solve such problems in the comparative example.

[0043] (Embodiment 2) 11 and 12 show the working machine according to the second embodiment as viewed from the rear with the tail cover removed. The shielding portion 40A in the working machine of this embodiment extends longer in the circumferential direction than the shielding portion 40 of the first embodiment. Correspondingly, the rib 42A is shorter in the circumferential direction than the rib 42 of the first embodiment. Other points of this embodiment are the same as those of the first embodiment. This embodiment also achieves the same effects as the first embodiment.

[0044] (Embodiment 3) FIG. 13 is a cross-sectional view of a main part of a working machine according to a third embodiment. In FIG. 13, the crossover wire is omitted. The working machine of this embodiment is a circular saw. The insulator 26B of the motor 20B has a shielding portion 40B at the end on the fan 43B side. The shielding portion 40B extends radially outward of the motor 20B until it approaches the inner periphery of the housing 11B or the fan guide portion 42B of the housing 11B. The shielding portion 40B has the same effect as the shielding portion 40 of the first embodiment.

[0045] Although the present invention has been described above using the embodiment as an example, the present invention is not limited to the embodiment. Various modifications are possible to each of the items specifically described in the embodiment within the scope of the claims. The present invention is not limited to the impact driver and circular saw exemplified in the embodiment, but can be applied to any type of work machine having a motor and a fan. [Explanation of symbols]

[0046] 1...working machine, 10...housing, 11...motor accommodating section, 12...handle section, 13...battery pack mounting section, 14...tail cover, 15...trigger switch, 16...forward / reverse switch, 17...battery pack, 18...hammer case, 19...operation panel, 20...motor, 21...motor shaft (output shaft), 22...rotor, 22a...rotor core, 22b...rotor magnet, 23...stator core, 24...stator coil, 25...front insulator, 26...rear insulator, 28...reduction mechanism, 29...spindle, 30...rotary impact mechanism (impact mechanism), 31...spring, 32...hammer, 33...anvil, 34...fan, 35...first control board, 36...second control board, 37...air intake, 38...air exhaust, 39...tip tool mounting hole, 40...shielding section (fan guide section), 41...crossover, 42...rib.

Claims

1. a motor including a rotor, a stator including a stator core wound with a coil around an outer periphery of the rotor, and an insulator insulating the stator core from the coil; a fan located on one side of the insulator in the axial direction of the motor and rotating integrally with the rotor; a housing that houses the motor and the fan, the housing having an air intake and an exhaust port located on an outer periphery side of the fan; A work machine equipped with an air flow passage is formed from the intake port through the inside of the stator and the fan to the exhaust port; a shielding portion that prevents the air that has passed through the fan from entering a space between an outer periphery of the stator and an inner periphery of the housing, the shielding portion being formed as a single member together with the insulator; A work machine characterized by:

2. The work machine according to claim 1, the shielding portion extends radially outward from a portion of the insulator that is positioned outer than the coil in a radial direction of the motor, and also extends in a circumferential direction of the motor. A work machine characterized by:

3. a motor including an output shaft, a rotor core that rotates integrally with the output shaft, a stator core that faces the rotor core and has a coil wound therearound, and an insulator that is connected to the stator core and insulates the stator core from the coil; A fan that rotates integrally with the output shaft; a housing having the motor and the fan; A work machine equipped with a shielding portion that protrudes radially outward from a portion of the insulator that is located outside the coil in a radial direction of the motor and between the stator core and the fan and extends in a circumferential direction of the motor, and forms a single member with the insulator; A work machine characterized by:

4. A work machine according to any one of claims 1 to 3, The shielding portion is provided discontinuously in a circumferential direction of the motor. A work machine characterized by:

5. The working machine according to claim 4, The housing has a rib that protrudes inward from an inner periphery of the housing and extends in the circumferential direction, The rib is located or extends between adjacent shielding portions in the circumferential direction. A work machine characterized by:

6. The work machine according to claim 5, an area in the axial direction of the motor where the rib is present and an area in the axial direction of the motor where the shielding portion is present at least partially overlap each other; A work machine characterized by:

7. A work machine according to any one of claims 1 to 3, In the axial direction of the motor, the fan side end of the shielding portion is located at the same position as the fan side end of the coil or is located closer to the stator core than the fan side end of the coil. A work machine characterized by:

8. A work machine according to any one of claims 1 to 3, In a radial direction of the motor, the shielding portion extends to an outer side than the fan. A work machine characterized by:

9. A work machine according to any one of claims 1 to 3, the insulator guides a jumper wire of the coil between the stator core and the shielding portion, In a radial direction of the motor, the shielding portion extends to an outer side than the crossover wire. A work machine characterized by:

10. A work machine according to any one of claims 1 to 3, The shielding portion is inseparable from the insulator. A work machine characterized by:

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