JP2024043274A - Electric device - Google Patents

Abstract

To provide an electric device which can inhibit wear of a housing or displacement between the housing and a motor.SOLUTION: A rear insulator 26 of a motor 20 has a left protruding part 41 and a right protruding part 42. Screws 45, 46 penetrate through a tail cover 14 and the left protruding part 41 and the right protruding part 42 to be engaged with a motor housing part 11 threadedly. In the structure, the tail cover 14 is fixed covering a rear opening of the motor housing part 11 and the left protruding part 41 and the right protruding part 42 of the rear insulator 26 are sandwiched between the tail cover 14 and the motor housing part 11 in an anteroposterior direction.SELECTED DRAWING: Figure 7

Description

The present invention relates to electrical equipment.

BACKGROUND OF THE INVENTION Electrical equipment, such as power tools, typically contain a motor in a housing. Patent Document 1 discloses a configuration in which a motor is supported within a housing by fitting a protrusion provided on the outer periphery of the motor into a recess provided on the inner surface of the housing.

Japanese Patent Application Publication No. 2008-296289

In the configuration disclosed in Patent Document 1, vibrations generated during operation of the electrical device may generate friction at the fitting portion of the housing and the motor, causing the housing to wear out or the positions of the two to shift.

The object of the present invention is to provide an electrical device that can suppress housing wear or misalignment between the housing and the motor.

An embodiment of the present invention is an electrical device. This electrical equipment is
A motor having a rotor and a stator provided on the radially outer side of the rotor;
a housing that accommodates the motor and is open on one side in the axial direction of the motor;
a cover connected to the opening of the housing;
An electrical device equipped with
The stator has a protrusion on an outer circumference that protrudes radially outward,
The protruding portion is sandwiched between the housing and the cover in the axial direction.

Another aspect of the invention is an electrical device. This electrical equipment is
A motor having a rotor and a stator provided on the radially outer side of the rotor;
a housing that accommodates the motor;
An electrical device equipped with
The stator has a protrusion on an outer circumference that protrudes radially outward,
A screw is provided for tightening the protrusion to the housing in the axial direction.

The present invention may be expressed as a "work machine", "power tool", etc., and such expressions are also effective as aspects of the present invention.

The present invention provides an electrical device that can suppress housing wear or misalignment between the housing and the motor.

FIG. 1 is a right side view of electrical equipment 1 according to Embodiment 1 of the present invention. FIG. 2 is a right side sectional view of the electrical device 1. FIG. FIG. 4 is a diagram with the tail cover 14 removed in FIG. 3. V-V sectional view of FIG. 2. FIG. 3 is a right side view of the left part of the housing 10 and the main parts of the tail cover 14; VII-VII sectional view in Figure 1. FIG. 2 is an exploded perspective view of the housing 10 and its internal configuration. (A) is an exploded perspective view of a stator set in the electrical device 1. (B) is a perspective view of the stator assembly. FIG. 2 is a sectional view of a main part of an electric device according to a second embodiment of the present invention. FIG. 11 is a cross-sectional view of a main portion of an electrical device according to a third embodiment of the present invention.

(Embodiment 1)
1 to 9 relate to an electric device 1 according to a first embodiment of the present invention. The electric device 1 is a work machine, specifically an impact driver. Figures 1 to 7 define front-rear, up-down, and left-right directions that are mutually perpendicular in the electric device 1. The front-rear direction is a direction parallel to the motor shaft 21 (motor axial direction).

Electrical equipment 1 has a housing 10 . The housing 10 is, for example, a resin molded body having a left-right and left-right split structure. The housing 10 includes a motor housing section 11 , a handle section 12 , and a battery pack mounting section 13 .

The motor accommodating portion 11 is a cylindrical portion whose central axis is substantially parallel to the front-rear direction. The handle portion 12 has an upper end connected to an intermediate portion of the motor accommodating portion 11 in the front-rear direction, and extends downward from the intermediate portion. The battery pack mounting part 13 is provided at the lower end of the handle part 12, and the battery pack 17 can be detachably mounted thereon. The electric device 1 operates using power from the battery pack 17.

The electrical device 1 includes a tail cover 14 connected to the rear opening of the motor housing portion 11 and covering the opening. The tail cover 14 is fixed to the motor accommodating part 11 with screws 45 and 46. As shown in FIG. 8, the tail cover 14 has through holes 55, 56 on the left and right sides for passing screws 45, 46 therethrough.

The electric device 1 has a hammer case 18 connected to the front part of the motor accommodating part 11. The hammer case 18 is made of metal, for example, and is held in the motor housing part 11 and extends forward from the motor housing part 11 .

The electric device 1 has a trigger switch 15 at the upper end of the handle portion 12, which is used by a user to switch between driving and stopping the motor 20. The electrical device 1 includes a forward/reverse switch 16 near the boundary between the motor accommodating portion 11 and the handle portion 12, which allows the user to switch between forward and reverse rotation of the motor 20. The electrical device 1 includes a first control board 35 inside the battery pack mounting section 13 . The first control board 35 is equipped with a control section such as a microcomputer that controls the drive of the motor 20.

The work machine 1 includes a motor 20 , a speed reduction mechanism 28 , a spindle 29 , a rotary impact mechanism 30 , and a fan 34 inside the motor accommodating portion 11 and the hammer case 18 .

The motor 20 is an inner rotor type brushless motor, and has a motor shaft 21 parallel to the front-rear direction. Motor 20 includes a rotor 22, a stator core 23, a stator coil 24, a front insulator 25, and a rear insulator 26. In FIGS. 5, 8, and 9, illustration of the stator coil 24 is omitted.

The rotor 22 is provided around the motor shaft 21 and rotates together with the motor shaft 21. The stator core 23, the stator coil 24, the front insulator 25, and the rear insulator 26 constitute a stator of the electrical device 1. In addition, in FIG. 9, a stator set is defined as a stator plus a second control board 36, which will be described later.

The stator core 23 is provided radially outside the rotor 22. The stator coil 24 is provided on the stator core 23. The front insulator 25 is provided in the front part of the stator core 23. The rear insulator 26 is provided in the rear part of the stator core 23. The front insulator 25 and the rear insulator 26 are, for example, resin molded bodies, and provide insulation between the stator core 23 and the stator coil 24.

A second control board 36 is attached to the front part 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 .

The deceleration mechanism 28 decelerates the rotation of the motor 20 and transmits it to the spindle 29. The spindle 29 drives a rotary striking mechanism 30. The rotary impact mechanism 30 is an output section of the electric device 1 and is driven by the motor 20.

The rotary impact mechanism 30 includes a spring 31, a hammer 32, and an anvil 33. The anvil 33 holds a tip tool such as a bit (not shown). The hammer 32 cams into engagement with the spindle 29 and is biased forward by a spring 31 . A hammer 32 driven by a spindle 29 rotationally strikes an anvil 33 . Since the configuration and operation of the rotary impact mechanism 30 are well known, further detailed explanation will be omitted.

The fan 34 is attached to the motor shaft 21 behind the rotor 22, rotates together with the motor shaft 21, and generates cooling air to cool the motor 20 and the like.

The electric device 1 is characterized by the holding structure of the motor 20.

As shown in FIGS. 4, 5, 7, and 8, the rear insulator 26 has a left protrusion 41 and a right protrusion 42 that protrude radially outward with respect to the outer circumference of the stator. The left protrusion 41 is an example of a first protrusion, and the right protrusion 42 is an example of a second protrusion.

8 and 9, the rear insulator 26 has an extension 57 extending rearward from the left rear portion of the outer circumferential surface, and a left protrusion 41 at the rear end of the extension 57. The left protrusion 41 protrudes radially outward, i.e., to the left, from the rear end of the extension 57. The rear insulator 26 also has an extension 58 extending rearward from the right rear portion of the outer circumferential surface, and a right protrusion 42 at the rear end of the extension 58. The right protrusion 42 protrudes radially outward, i.e., to the right, from the rear end of the extension 58. The left protrusion 41 and the right protrusion 42 are plate-shaped portions perpendicular to the front-rear direction, and have through holes 43, 44 for passing screws 45, 46, respectively.

As shown in FIG. 8, the housing 10 is made by combining a left housing 51 as a first housing and a right housing 52 as a second housing into one body by screwing or the like. The stator core 23 is sandwiched between the two. The left housing 51 has a left insertion portion 47 into which the left protrusion 41 is inserted. The right housing 52 has a right insertion portion 48 into which the right protrusion 42 is inserted. The left insertion portion 47 and the right insertion portion 48 are configured as recesses that are recessed forward at the rear end portion of the motor accommodating portion 11 . Screw holes 53 and 54 into which screws 45 and 46 are screwed are opened in the left insertion portion 47 and the right insertion portion 48, respectively.

The screws 45 and 46 pass through the through holes 55 and 56 of the tail cover 14 and the through holes 43 and 44 of the left protruding part 41 and the right protruding part 42 of the rear insulator 26, and pass through the screws of the left housing 51 and the right housing 52. Screw into holes 53 and 54. As a result, as shown in FIG. 7, the tail cover 14 is fixed in a state covering the rear opening of the motor accommodating portion 11, and the left protrusion 41 and the right protrusion 42 of the rear insulator 26 are attached to the tail cover in the front-rear direction. 14 and the motor accommodating part 11, and is tightened to the motor accommodating part 11.

As shown in FIG. 8, the stator core 23 has a convex portion 59 on the outer circumference that protrudes radially outward. In the illustrated example, four convex portions 59 are provided at approximately 90 degree intervals in the circumferential direction. The housing 10 has fitting portions 60 (recesses) on the inner surface into which each of the protrusions 59 fits. The number of protrusions 59 can be changed arbitrarily.

This embodiment has the following effects.

(1) The rear insulator 26 has a left protrusion 41 and a right protrusion 42, and the left protrusion 41 and the right protrusion 42 are sandwiched between the tail cover 14 and the motor accommodating part 11 in the front-rear direction. Therefore, the support (fixation) of the stator to the housing 10 becomes stronger compared to the case where the stator is only supported by the fitting between the convex portion 59 of the stator core 23 and the fitting portion 60 of the housing 10. Therefore, wear of the fitting portion 60 of the housing 10 and misalignment of the motor 20 with respect to the housing 10 due to vibrations during work can be suppressed. Misalignment of the motor 20 in the front-back direction with respect to the housing 10 and misalignment of the motor 20 in the circumferential direction can be suppressed.

(2) The left protruding part 41 and the right protruding part 42 are held between the tail cover 14 and the motor accommodating part 11 in the front-rear direction by the fastening force of the screws 45 and 46 passing through them. Therefore, the stator is strongly supported (fixed) to the housing 10, and the effect of suppressing the wear of the fitting portion 60 of the housing 10 and the displacement of the motor 20 with respect to the housing 10 described above is enhanced. The effect of suppressing displacement of the motor 20 in the longitudinal direction with respect to the housing 10 and displacement of the motor 20 in the circumferential direction is enhanced.

(3) Since the screws 45 and 46 are screws that fix the tail cover 14 to the housing 10, an increase in the number of parts required to generate a clamping force for the left protrusion 41 and the right protrusion 42 can be suppressed.

(4) By inserting the left protrusion 41 and right protrusion 42 of the rear insulator 26 into the left insertion part 47 and right insertion part 48 of the housing 10, the convex part 59 of the stator core 23 and the fitting part 60 of the housing 10 are inserted. Easy to assemble as it can be aligned with the In addition, by inserting the protruding portion into the insertion portion, the motor 20 can be fixed to the housing 10 in the radial direction, and displacement in the front-rear direction with respect to the housing 10 and displacement in the circumferential direction of the motor 20 can be suppressed.

(Embodiment 2)
FIG. 10 is a sectional view of essential parts of an electrical device according to Embodiment 2 of the present invention. Hereinafter, differences from Embodiment 1 will be mainly explained in comparison with FIG. 7. In this embodiment, the rear insulator 126 corresponding to the rear insulator 26 of Embodiment 1 has the left protrusion 41 and the right protrusion 42 of the rear insulator 26, but has through holes 43 and 44. do not have. The left protrusion 41 and the right protrusion 42 have a smaller protrusion amount radially outward from the outer periphery of the motor 20 (stator core 23) than those in the first embodiment. The amount of protrusion extends to the outside in the radial direction from the inner diameter portion of the motor housing portion 11 . The motor accommodating portion 11 is provided with an insertion portion into which the left protrusion 41 and the right protrusion 42 are respectively inserted. As a result, in the motor 20, the left protruding part 41 and the right protruding part 42 are sandwiched between the tail cover 14 and the motor accommodating part 11 in the front-rear direction. On the other hand, the front insulator 125 corresponding to the front insulator 25 of Embodiment 1 has a left protrusion 141 and a right protrusion 142 that correspond to the left protrusion 41 and the right protrusion 42. The left protrusion 141 and the right protrusion 142 have through holes through which screws 45 and 46 are passed. The motor accommodating part 111 corresponding to the motor accommodating part 11 has a left insertion part 147 and a right insertion part 148 into which the left protrusion 141 and the right protrusion 142 are inserted. The motor accommodating portion 111 has screw holes 53 and 54 (see FIG. 8) into which screws 45 and 46 are screwed, as in the first embodiment. This embodiment also has the same effects as the first embodiment. In this embodiment, the through holes for passing the screws 45 and 46 of the left protrusion 141 and the right protrusion 142 are screw holes, and the holes for passing the screws 45 and 46 provided in the motor housing part 111 do not need to be provided with screws. (may be a through hole), or may be a screw hole into which the screws 45 and 46 are screwed only in the portion located forward of the left protrusion 141 and the right protrusion 142.

(Embodiment 3)
FIG. 11 is a sectional view of essential parts of an electrical device according to Embodiment 3 of the present invention. Hereinafter, differences from Embodiment 1 will be mainly explained in comparison with FIG. 7. In this embodiment, the rear insulator 126 corresponding to the rear insulator 26 of Embodiment 1 has the left protrusion 41 and the right protrusion 42 of the rear insulator 26, but has through holes 43 and 44. do not have. The left protruding portion 41, the right protruding portion 42, and the insertion portion of the motor accommodating portion 11 are configured in the same manner as in the second embodiment. On the other hand, the stator core 123 corresponding to the stator core 23 of Embodiment 1 has a left protrusion 241 and a right protrusion 242 that correspond to the left protrusion 41 and the right protrusion 42. The motor accommodating part 111 corresponding to the motor accommodating part 11 has a left insertion part 147 and a right insertion part 148 into which the left protrusion 241 and the right protrusion 242 are inserted. The motor accommodating portion 111 has screw holes 53 and 54 (see FIG. 8) into which screws 45 and 46 are screwed, as in the first embodiment. The left protrusion 241 and the right protrusion 242 have through holes through which screws 45 and 46 are passed. This embodiment also has the same effects as the first embodiment. In this embodiment, the through holes for passing the screws 45 and 46 of the left protruding part 241 and the right protruding part 242 are screw holes, and the holes for passing the screws 45 and 46 provided in the motor housing part 111 do not need to be provided with screws. (may be a through hole), or may be a screw hole into which the screws 45 and 46 are screwed only in the portion located forward of the left protrusion 241 and the right protrusion 242.

The present invention has been described above using the embodiments as examples, but the present invention is not limited to the embodiments. Various modifications are possible to each of the matters specifically described in the embodiments within the scope of the claims.

In the embodiment, the case where there are two protrusions is illustrated, but the number of protrusions may be one or three or more. Having two protrusions on the left and right makes it possible to support (fix) the stator in a well-balanced and strong manner, but even if there is only one protrusion, the fitting part 60 of the housing 10 may wear out or the motor 20 may become misaligned with respect to the housing 10. A certain effect can be obtained in suppressing the Alternatively, the protrusion may be provided all around the stator. In addition, although the case where the protrusion is provided in any one of the front insulator, the rear insulator, and the stator core is illustrated, the protrusion may be provided in two or more of the front insulator, the rear insulator, and the stator core by combining these parts. good.

The electrical equipment of the present invention may be of a type that does not have a cover corresponding to the tail cover 14. Even in this case, by screwing the protrusion to the housing from the front and back directions, the support (fixation) of the stator to the housing is strengthened, and this prevents wear of the fitting part 60 of the housing 10 and misalignment of the motor 20 with respect to the housing 10. can be suppressed.

The electrical device of the present invention is not limited to impact drivers, but may be other types such as impact wrenches and vibration drill drivers. The present invention is particularly effective for electrical devices that generate large vibrations during use, but is not limited to them and can be applied to all electrical devices that have motors.

DESCRIPTION OF SYMBOLS 1...Electrical equipment, 10...Housing, 11...Motor accommodating part, 12...Handle part, 13...Battery pack attachment part, 14...Tail cover, 15...Trigger switch, 16...Forward/reverse changeover switch, 17...Battery pack, 18 ...Hammer case, 20...Motor, 21...Motor shaft, 22...Rotor, 23...Stator core, 24...Stator coil, 25...Front insulator, 26...Rear insulator, 28...Deceleration mechanism, 29...Spindle, 30...Rotary impact Mechanism, 31...Spring, 32...Hammer, 33...Anvil, 34...Fan, 35...First control board, 36...Second control board, 41...Left protrusion (first protrusion), 42...Right protrusion ( 43, 44...Through hole, 45, 46...Screw, 47...Left insertion part, 48...Right insertion part, 51...Left housing (first housing), 52...Right housing (second housing) , 53, 54...screw hole, 55, 56...through hole, 57, 58...extension part, 59...convex part, 60...fitting part, 111...motor housing part, 123...stator core, 125...front insulator, 126... Rear side insulator, 141...Left protrusion (first protrusion), 142...Right protrusion (second protrusion), 147...Left insertion part, 148...Right insertion part, 241...Left protrusion (first protrusion) ), 242...Right protrusion (second protrusion).

Claims (11)

A motor having a rotor and a stator provided on the radially outer side of the rotor;
a housing that accommodates the motor and is open on one side in the axial direction of the motor;
a cover connected to the opening of the housing;
An electrical device equipped with
The stator has a protrusion on an outer circumference that protrudes radially outward,
the protrusion is sandwiched between the housing and the cover in the axial direction;
An electrical device characterized by: 2. The electrical device according to claim 1 ,
The housing has a first and a second housing that are separable from each other, and the stator is sandwiched between the first and second housings.
1. An electrical device comprising: The electrical device according to claim 1 or 2,
a screw for tightening the protrusion in the axial direction with respect to the housing;
An electrical device characterized by: 4. The electrical device according to claim 3,
The screw fastens the cover to the housing.
1. An electrical device comprising: 3. The electrical device according to claim 1,
The housing has an insertion portion into which the protrusion is inserted.
1. An electrical device comprising: 3. The electrical device according to claim 1,
the stator includes a stator core and an insulator,
The protrusion is provided on the insulator.
1. An electrical device comprising: The electrical device according to claim 6,
The insulator includes a one-side insulator located on one side of the stator core in the axial direction, and a second insulator located on the other side of the stator core in the axial direction,
The protruding portion is provided on at least one of the one side insulator and the other side insulator,
An electrical device characterized by: The electrical device according to claim 1 or 2,
The stator has a stator core,
The protrusion is provided on the stator core,
An electrical device characterized by: The electrical device according to claim 2,
The protrusion includes a first protrusion facing the first housing and a second protrusion facing the second housing.
An electrical device characterized by: The electrical device according to claim 6,
The stator core has a convex portion protruding radially outward on an outer peripheral portion,
A fitting part into which the convex part fits is provided on the inner surface of the housing.
An electrical device characterized by: A motor having a rotor and a stator provided on the radially outer side of the rotor;
a housing that accommodates the motor;
An electrical device equipped with
The stator has a protrusion on an outer circumference that protrudes radially outward,
a screw for tightening the protrusion in the axial direction with respect to the housing;
An electrical device characterized by:

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