Motor units and power tools

Abstract

To provide a motor unit which can be used in power tools having various forms.SOLUTION: A motor unit includes a motor and a motor case which houses the motor. In the motor case, a grip fixing part to which a grip member is fixed and an adapter fixing part to which a grip adapter is fixed are disposed. The motor unit allows the grip member and the grip adapter to be attached thereto selectively. When the grip member is directly attached to the motor unit, the grip member is arranged so as to extend in a direction of a rotation axis of the motor. When the grip adapter is attached to the motor unit, the grip member attached to the grip fixing part of the grip adapter is arranged to extend in a direction orthogonal to the rotation axis.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a motor unit for use in various forms of power tools, and to a power tool provided with such a motor unit.

Background Art

[0002] There are various types of power tools that use a motor as a drive source. Examples of such power tools include a belt-type grinding tool (Patent Document 1) configured to perform grinding work by rotationally driving an endless grinding belt, a grinder (Patent Document 2) configured to perform grinding work by rotationally driving a disc-shaped grinding wheel, and a drilling machine (Patent Document 3) configured to perform drilling work by rotationally driving a drill. In addition, a power tool may be attached to a robot arm to perform various machining operations under automatic control by the robot.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] The various forms of power tools described above typically have housings specifically designed to accommodate and hold the motor and other components, optimized for their respective tasks. More specifically, the motor case that holds the motor is usually integrated with the grip portion held by the operator, or, even if it is a separate component, it is designed to connect only to a specific grip portion. For example, in a handheld belt-type grinding tool, the direction in which the endless grinding belt extends and the direction in which the grip extends are usually the same, but depending on the task, it may be desirable for the grip to be perpendicular to the direction of the belt. To realize these different configurations, the housing that makes up the grip is specifically designed for each configuration. Furthermore, the configuration of the motor case in a handheld power tool and the motor case in a stationary drilling machine are usually different. Thus, the motor unit in a power tool, consisting of the motor and the motor case that houses it, is specifically designed for each form of power tool and is usually not interchangeable.

[0005] Therefore, the present invention aims to provide a motor unit that can be used in various forms of power tools, and a power tool equipped with such a motor unit. [Means for solving the problem]

[0006] In other words, the present invention is A motor unit used in various types of power tools, Motor and, A motor case housing the aforementioned motor, A first fixing portion is provided on the motor case, and a first attachment member, which constitutes part of a certain type of power tool, is fixed to it. A second fixing portion is provided on the motor case, and a second attachment member, which constitutes part of another form of power tool, is fixed to it. Equipped with, The present invention provides a motor unit in which the first attachment member and the second attachment member can be selectively attached to the motor case.

[0007] Since the motor unit is designed to allow the selective attachment of multiple attachment members that constitute parts of different types of power tools, it can be used in common with various types of power tools.

[0008] Also, The first attachment member is a first grip member that constitutes a grip portion, and is configured to extend from the motor case in a predetermined first direction when fixed to the first fixing portion. The second attachment member may be a grip adapter having a grip fixing portion for fixing a second grip member that constitutes the grip portion, and such that when fixed to the second fixing portion, the second grip member fixed to the grip fixing portion extends in a second direction that intersects the first direction.

[0009] Furthermore, the first grip member and the second grip member can be the same.

[0010] Furthermore, the first direction may be the direction of the rotation axis of the motor housed in the motor case, and the second direction may be the direction perpendicular to the rotation axis of the motor.

[0011] This configuration makes it possible to attach and use a single grip component in different directions.

[0012] At least one of the first attachment member and the second attachment member may be an adapter having a mounting portion for attaching the motor unit to another device.

[0013] Furthermore, at least one of the first attachment member and the second attachment member may be a cover that covers at least a part of the motor unit.

[0014] In addition, The motor case includes a motor housing having an accommodation recess for accommodating the motor, and a bracket attached to the motor housing on the opening side of the accommodation recess, The first fixing portion may be provided on the motor housing, and the second fixing portion may be provided on the bracket.

[0015] Furthermore, the motor housing may be formed as an integrally formed cup-shaped member made of resin.

[0016] While this type of housing member in power tools is often formed by two divided members, since the motor housing of the present invention is formed as an integral member, it can have higher strength than a divided one, and the position of the accommodated motor can be determined more accurately.

[0017] The present invention also provides, The motor unit described above, and One attachment member selected from the first attachment member attached to the first fixing portion of the motor unit and the second attachment member attached to the second fixing portion, A power tool comprising the same.

[0018] Furthermore, the present invention provides, A motor, A motor case that accommodates and holds the motor, the motor case having a first fixing portion and a second fixing portion, A grip member constituting a grip portion, which can be fixed to the motor case at the first fixing portion, and extends from the motor case in a predetermined first direction when fixed to the first fixing portion, a grip adapter that has a grip fixing portion which can be fixed to the motor case at the second fixing portion and can fix the grip member, and is configured such that the grip member fixed to the grip fixing portion when fixed to the second fixing portion extends in a second direction intersecting the first direction; comprising, the grip member and the grip adapter are configured to be selectively attachable to the motor case, the motor case includes a motor housing having an accommodation recess for accommodating the motor, and a bracket attached to the motor housing on the opening side of the accommodation recess, the motor housing is formed as a cup-shaped integral member made of resin, the grip member has a first split member and a second split member formed as separate bodies, and is configured to be attachable to the motor case such that the first fixing portion is sandwiched between the first split member and the second split member, and is configured to be attachable to the grip adapter such that the grip fixing portion is sandwiched between the first split member and the second split member. A power tool is provided.

[0019] Hereinafter, embodiments of the motor unit and the power tool according to the present invention will be described with reference to the accompanying drawings. [Brief Description of the Drawings]

[0020] [Figure 1] It is a perspective view of the power tool (belt-type grinding tool) according to the first embodiment of the present invention. [Figure 2] It is an exploded perspective view of the belt-type grinding tool of Fig. 1. [Figure 3] It is a top cross-sectional view of the belt-type grinding tool of Fig. 1. [Figure 4] It is a front perspective view of the motor unit included in the belt-type grinding tool of Fig. 1. [Figure 5] It is a rear perspective view of the motor unit of Fig. 4. [Figure 6] It is a side cross-sectional view of the motor unit of Fig. 4. [Figure 7]This is a perspective view of a belt-type grinding tool in which the grip component is directly attached to the motor case. [Figure 8] This is a perspective view of a power tool (belt-type grinding tool) according to a second embodiment of the present invention, in which a grip member for an AC power supply is directly attached to the motor case. [Figure 9] This is a perspective view of a power tool (belt-type grinding tool) according to a third embodiment of the present invention, in which an adapter for an automated machine for mounting on a robot arm is attached to the motor unit. [Figure 10] Figure 9 is a side view of the belt-type grinding tool. [Figure 11] This is an exploded perspective view of a power tool (drilling machine) according to a fourth embodiment of the present invention. [Figure 12] This is a perspective view of a power tool (grinder) according to a fifth embodiment of the present invention. [Modes for carrying out the invention]

[0021] The power tool 100 according to the first embodiment of the present invention is a battery-powered belt-type grinding tool 100 that performs grinding work by rotating an endless grinding belt, as shown in Figures 1 to 3.

[0022] The belt-type grinding tool 100 comprises a motor unit 102 containing a motor 110, a drive unit 104 attached to the motor unit 102, a grip member 106 constituting a grip portion 112 for the operator to hold, and a grip adapter 108 attached between the motor unit 102 and the grip member 106.

[0023] As shown in detail in Figures 4 to 6, the motor unit 102 mainly comprises a motor 110 and a motor case 114 housing the motor 110. The motor 110 is a brushless motor and has a stator core 116 fixed to the motor case 114, a stator coil 118 wound around the stator core 116, a rotor 120 positioned inside the stator core 116 and rotatable around a rotation axis R relative to the stator core 116, and a rotating shaft 122 fixed to the rotor 120. The motor 110 further has an insulating insulator 124 positioned between the stator coil 118 and the stator core 116. The insulator 124 is a resin component integrally molded with the stator core 116. The motor case 114 consists of a motor housing 128 having a housing recess 126 that accommodates the stator core 116 and rotor 120 of the motor 110, and a bracket 132 attached to the motor housing 128 on the side of the opening 130 of the housing recess 126. The bracket 132 is fixed to the motor housing 128 by four screws 134 (Figure 4) and holds the motor 110 in the housing recess 126. The rotating shaft 122 is rotatably held by two bearings 136 such that its end protrudes from the bracket 132, and is also fixed to the rotor 120 and rotated together with the rotor 120. The motor unit 102 further includes a fan 138 fixed to the rotating shaft 122 within the motor case 114, and an airflow guide member 140 for directing the radially outward airflow generated by the fan 138 towards the bracket 132. The motor housing 128 is formed as a cup-shaped, one-piece component made of resin. Typically, this type of housing component is formed from two separate components, but the motor housing 128 of the present invention is formed as a single integrated component, resulting in higher strength compared to a segmented design, and also enabling more precise alignment of the rotor 120 and stator core 116.

[0024] As shown in Figure 3, the drive unit 104 comprises a base member 142 fixed to a bracket 132 of the motor unit 102, a tension bar 144 mounted on the base member 142 so as to be displaceable in the longitudinal direction, an idler pulley 146 rotatably mounted on the tip of the tension bar 144, and a drive pulley 148 fixed to the rotation shaft 122 of the motor unit 102. The tension bar 144 is biased forward (to the left in Figure 3) by a spring 150. An endless grinding belt 152 is wrapped around the idler pulley 146 and the drive pulley 148. The endless grinding belt 152 is mounted between the idler pulley 146 and the drive pulley 148 with tension applied by the biasing force of the spring 150. An openable and closable cover 154 is attached to the base member 142 so as to cover the drive pulley 148 on its side.

[0025] As shown in Figure 2, the grip adapter 108 has a housing portion 156 that accommodates the motor case 114 and an extension portion 158 that extends rearward from the housing portion 156. The extension portion 158 is provided with a grip fixing portion 160 for attaching the grip member 106. The grip fixing portion 160 consists of a boss 160-1 that protrudes rearward from the extension portion 158 and an annular locking groove 160-2 formed on the outer circumferential surface of the extension portion 158. The grip adapter 108 is fixed to the adapter fixing portion 164 of the bracket 132 with four screws 166 at the end face 162 of the housing portion 156. A switch 168 for turning the operation of the belt-type grinding tool 100 ON / OFF is also attached to the grip adapter 108.

[0026] The grip member 106 consists of a first divided member 170 and a second divided member 172, which are formed separately. The front end portions of the first divided member 170 and the second divided member 172 have fixing portions 174 formed thereon so as to be attached to the grip fixing portion 160 of the grip adapter 108. The fixing portion 174 consists of a projection 174-1 that protrudes laterally inside the first divided member 170 and the second divided member 172, and an annular projection 174-2 that protrudes radially inward at the front ends of the first divided member 170 and the second divided member 172. The grip member 106 is fixed to the grip adapter 108 by fixing the first and second divided members 170 and 172 to each other with five screws 176, with the boss 160-1 sandwiched from the side by the protrusions 174-1 of the first and second divided members 172, and the annular locking groove 160-2 locked by the annular projection 174-2. Two of the five screws 176 are tightened through the protrusions 174-1 of the first and second divided members 170 and 172 and the boss 160-1 of the grip member 106. A battery mounting portion 178 for mounting the battery B is formed at the rear end of the grip member 106. A control circuit 180 for controlling the belt-type grinding tool 100 is built into the vicinity of the battery mounting portion 178.

[0027] As can be clearly seen in Figures 4 and 5, the rear end portion of the motor case 114 has a grip fixing portion 182 having a boss 182-1 and an annular locking groove 182-2, which are similar in shape to the grip fixing portion 160 of the grip adapter 108. Therefore, the grip adapter 108 in the configuration shown in Figure 1 can be removed from the motor case 114, and the grip member 106 can be directly attached to the motor case 114 as shown in Figure 7. In other words, in this belt-type grinding tool 100, the motor case 114 of the motor unit 102 has a grip fixing portion 182 (first fixing portion) for fixing the grip member 106 (first attachment member) and an adapter fixing portion 164 (second fixing portion) for fixing the grip adapter 108 (second attachment member), and the grip member 106 and the grip adapter 108 can be selectively attached to the motor case 114. As a result, it is possible to realize two configurations using the same motor case 114: one in which the grip member 106 is directly attached to the motor case 114, as shown in Figure 7, and the grip member 106 extends in the direction of the rotation axis R of the motor 110 (first direction); and another in which the grip member 106 is attached to the motor case 114 via a grip adapter 108, and the grip member 106 extends in the direction of an axis L perpendicular to the rotation axis R of the motor 110 (second direction), as shown in Figure 1. Note that the switch 168, which was attached to the grip adapter 108 in the configuration of Figure 1, is attached to the motor case 114 in the configuration of Figure 7.

[0028] In the power tool (belt-type grinding tool) 200 according to the second embodiment of the present invention shown in Figure 8, the grip member 206 (another attachment member) is for AC power. This grip member 206 incorporates a circuit board on which electrical components for commercial power are mounted, and also has a power cord (not shown) for connecting to commercial power. This grip member 206 can also be directly attached to the motor case 114 of the motor unit 102, similar to the configuration shown in Figure 7. Note that the grip adapter 108 and the grip member attached to the motor unit 102 are not limited to these, and other arbitrary forms such as a pistol shape or one with a built-in rechargeable battery can also be used.

[0029] In the power tool (belt-type grinding tool) 300 according to the third embodiment of the present invention shown in Figures 9 and 10, an automatic machine adapter (another attachment member) 308 is attached to the motor unit 102 instead of the grip adapter 108. This automatic machine adapter 308 has a mounting portion 385 for attaching the motor unit 102 to other devices such as the robot arm of an automatic machine. The automatic machine adapter 308 is fixed not to the adapter fixing portion 164 of the bracket 132, but to another fixing portion 184 (Figure 5) consisting of two screw holes formed at the rear end of the motor housing 128 by two screws 386. The shape of the automatic machine adapter 308 can be appropriately changed to suit the automatic machine to which it is attached.

[0030] In the power tool (punching machine) 400 according to the fourth embodiment of the present invention shown in Figure 11, a cover case 408 (another attachment member) is attached to the motor unit 102 instead of the grip adapter 108. This cover case 408 is fixed to a fixing part 184 (Figure 5) formed at the rear end of the motor housing 128 by two screws 484, similar to the adapter 308 for automatic machines. The motor unit 102 to which the cover case 408 is attached is attached to the punching machine body 488 by screws using the holes in the adapter fixing part 164 that were used to fix the grip adapter 108 in the power tool 100 according to the first embodiment. This allows the motor unit 102 to rotate the annular cutter 486 of the punching machine 400.

[0031] In the power tool (grinder) 500 according to the fifth embodiment of the present invention shown in Figure 12, the motor case 114 of the motor unit 502 is the same as the motor case 114 in the above-described embodiment, but the bracket 532 has a gear case portion 590 that incorporates a gear structure. A bevel gear is arranged inside the gear case portion 590. The rotation axis of the gear structure rotates around the vertical rotation axis as seen in the figure, and a grinding wheel 586 is attached to its end. In this grinder 500 as well, other attachment members (for example, an automatic machine adapter 308) can be selectively attached to the motor case 114 instead of the grip member 106.

[0032] As described above, the motor units 102 and 502 according to the above embodiment are equipped with multiple fixing parts (grip fixing part 182, adapter fixing part 164 of bracket 132, fixing part 184 of motor housing 128) for various attachment members (grip member 106, grip adapter 108, grip member 206, automatic machine adapter 308, cover case 408, etc.), and multiple attachment members that constitute part of various power tools 100, 200, 300, 400, and 500 can be selectively attached. Therefore, it is possible to configure various forms of power tools 100, 200, 300, 400, and 500 using a common motor unit 102 and 502. This makes it possible to use the motor unit (especially the motor case) as a common part when manufacturing multiple types of power tools, for example, simplifying parts management and reducing manufacturing costs.

[0033] Although embodiments of the present invention have been described above, the present invention is not limited to these embodiments. For example, the motor case of the above embodiment has three fixing parts (grip fixing part, bracket fixing part, and motor housing fixing part) for fixing various attachment members, but it may have only two of these fixing parts, or it may have yet another fixing part. Also, the direction in which the grip adapter holds the grip member is not perpendicular to the rotation axis of the motor, but can be in another direction or position intersecting the rotation axis, such as a direction inclined at 45 or 60 degrees to the rotation axis. The shape of the grip fixing part of the grip adapter does not necessarily have to be the same shape as the grip fixing part of the motor unit, and it may be configured so that a grip member different from the grip member attached to the motor unit is attached. The power tool is not limited to the above, and may be other forms of power tools such as chamfering machines or electric screwdrivers. [Explanation of Symbols]

[0034] 100 Power tools, belt-driven grinding tools 102 Motor Unit 104 Drive Unit 106 Grip component (attachment component) 108. Grip adapter (attachment component) 110 Motor 112 Grip section 114 Motor Case 116 Stator Core 118 Stator Coil 120 rotors 122 Rotation axis 124 Insulators 126 Receiving recess 128 Motor Housing 130 opening 132 brackets 134 screws 136 Bearings 138 Fans 140 Airflow guide member 142 Base member 144 Tension Bar 146 Idler Pulley 148 Drive Pulley 150 Spring 152 Endless grinding belt 154 Cover 156 Housing section 158 Extension 160 Grip fixing part 160-1 Boss 160-2 Annular locking groove 162 End face 164 Adapter fixing part (second fixing part) 166 screws 168 switches 170 First divided member 172 Second divided member 174 Fixed part 174-1 Protrusion 174-2 Annular projection 176 screws 178 Battery mounting section 180 Control circuits 182 Grip fixing part (first fixing part) 182-1 Boss 182-2 Annular locking groove 184 Fixed part 200 Power Tools, Belt-Type Grinding Tools 206 Grip component (attachment component) 300 Power Tools, Belt-Type Grinding Tools 308 Adapter (attachment component) for automated machinery 385 Mounting part 386 screws 400 drilling machine 400 Power tools, drilling machines 408 Cover case (attachment component) 484 screws 486 Annular Cutter 488 Drilling machine body 500 Power Tools, Grinders 502 Motor Unit 532 Bracket 586 Sharpening Stone 590 Gear case section B Battery R rotation axis L is an orthogonal axis.

Claims

1. A motor unit used in various types of power tools, Motor and, A motor case housing the aforementioned motor, A first fixing portion is provided on the motor case, and a first attachment member, which constitutes part of a certain type of power tool, is fixed to it. A second fixing portion is provided on the motor case, and a second attachment member, which constitutes part of another type of power tool, is fixed to it. Equipped with, The first attachment member and the second attachment member can be selectively attached to the motor case. The first attachment member is a first grip member that constitutes a grip portion, which extends from the motor case in a predetermined first direction when fixed to the first fixing portion. The second attachment member has a grip fixing portion for fixing a second grip member that constitutes the grip portion, and is a grip adapter such that when fixed to the second fixing portion, the second grip member fixed to the grip fixing portion extends in a second direction that intersects the first direction. A motor unit in which the first direction is the direction of the rotation axis of the motor, and the second direction is the direction perpendicular to the rotation axis.

2. The motor unit according to claim 1, wherein the first grip member and the second grip member are the same.

3. A motor unit used in various forms of power tools, Motor and, A motor case housing the aforementioned motor, A first fixing portion is provided on the motor case, and a first attachment member, which constitutes part of a certain type of power tool, is fixed to it. A second fixing portion is provided on the motor case, and a second attachment member, which constitutes part of another type of power tool, is fixed to it. Equipped with, The first attachment member and the second attachment member can be selectively attached to the motor case. A motor unit in which at least one of the first attachment member and the second attachment member is an adapter for an automated machine having a mounting portion for attaching the motor unit to an automated machine.

4. A motor unit used in various forms of power tools, Motor and, A motor case housing the aforementioned motor, A first fixing portion is provided on the motor case, and a first attachment member, which constitutes part of a certain type of power tool, is fixed to it. A second fixing portion is provided on the motor case, and a second attachment member, which constitutes part of another type of power tool, is fixed to it. Equipped with, The first attachment member and the second attachment member can be selectively attached to the motor case. A motor unit in which at least one of the first attachment member and the second attachment member is a cover that covers at least a part of the motor unit.

5. The motor case comprises a motor housing having a housing recess for housing the motor, and a bracket attached to the motor housing on the side of the opening of the housing recess. The motor unit according to claim 1, wherein the first fixing portion is provided on the motor housing and the second fixing portion is provided on the bracket.

6. The motor unit according to claim 5, wherein the motor housing is formed as a cup-shaped integral member made of resin.

7. A motor unit according to any one of claims 1 to 6, One of the attachment members, which is attached to the first fixed portion of the motor unit and the second fixed portion, A power tool equipped with the following features.

8. Motor and, A motor case for housing and holding the motor, comprising a motor case having a first fixing portion and a second fixing portion, A grip member constituting a grip portion is provided, which is fixed to the motor case at the first fixing portion and extends from the motor case in a predetermined first direction when fixed to the first fixing portion, The grip adapter has a grip fixing portion which can be fixed to the motor case and to which the grip member can be fixed, and when fixed to the second fixing portion, the grip member fixed to the grip fixing portion extends in a second direction that intersects the first direction, Equipped with, The grip member and the grip adapter can be selectively attached to the motor case. The motor case comprises a motor housing having a housing recess for housing the motor, and a bracket attached to the motor housing on the side of the opening of the housing recess. The motor housing is formed as a cup-shaped, one-piece component made of resin. The grip member comprises a first divided member and a second divided member formed separately, and is attachable to the motor case by sandwiching the first fixing portion between the first divided member and the second divided member, and is attachable to the grip adapter by sandwiching the grip fixing portion between the first divided member and the second divided member, in a power tool.

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