Power tool

Abstract

A power tool capable of replacing a member for suppressing a battery from shaking and a filter together is provided. A power tool (belt grinding tool) (100) is driven by a battery (B) detachably attached. The power tool has a housing (192) having a battery attachment portion (178) and an air intake port (188), and a filter member (190) detachably attached to the housing. The filter member has a filter (196) covering the air intake port, and a filter fixing portion (198) holding the filter and fixed to the housing. The filter fixing portion has a frame portion (200) surrounding a periphery of the filter, and first to third attachment leg portions (202-1 to 202-3) extending from the frame portion. The first and second attachment leg portions (202-1, 202-2) partially project into the battery attachment portion (178). The first and second attachment leg portions abut against the battery to suppress the battery from shaking with respect to the housing.

Description

Technical Field

[0001] This invention relates to battery-powered power tools. Background Technology

[0002] In power tools such as belt grinders or polishing machines, power tools powered by removable batteries have been developed. These power tools generate vibration during operation, thus requiring vibration countermeasures for each component. In particular, the removable battery is fitted with a slight clearance relative to the battery mounting section of the power tool, making it prone to vibration relative to the battery mounting section. This causes friction and wear between the power tool and the battery connection terminals, easily leading to poor contact. Furthermore, due to repeated contact and separation between the power tool and battery connection terminals, sparks sometimes occur between the terminals, melting the resin portion holding the metal terminals and causing a change in terminal position, further resulting in poor contact.

[0003] To prevent such battery vibration or shaking, for example in Patent Document 1, an elastic absorbing member is embedded in the slide rail for assembling the battery, so that the battery is elastically supported by the elastic absorbing member to absorb vibration.

[0004] Furthermore, in power tools, it is sometimes necessary to cool the electric motor that generates heat during operation. For example, in Patent Document 2, a fan is mounted on the rotating shaft of the motor, which is housed within a housing. The fan, rotating via the motor, draws outside air into the housing, passes it around the motor, and exhausts it outside, thereby cooling the motor. A filter is provided at the air inlet to prevent dust and dirt from entering the housing.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent No. 6661328

[0008] Patent Document 2: Japanese Patent No. 6252778 Summary of the Invention

[0009] The problem that the invention aims to solve

[0010] The elastic damping components used to suppress battery vibration gradually wear down during repeated battery installation and removal, and deteriorate over time. Therefore, they need to be replaced periodically. Similarly, the air intake filter gradually becomes dirty with use and also needs to be replaced periodically. However, the elastic damping components and filters are installed in different locations as separate components, so they need to be replaced separately. Therefore, there is a possibility that replacement work becomes cumbersome, or that elastic damping components, especially those located in hard-to-notice locations, may become ineffective due to forgetting to be replaced.

[0011] Therefore, the object of the present invention is to provide a power tool that can replace both the components and the filter used to suppress battery sway at the same time.

[0012] Solution for solving the problem

[0013] That is, the present invention provides a power tool driven by a detachably mounted storage battery, wherein,

[0014] The power tool has the following features:

[0015] The housing has a battery assembly and an air inlet; and

[0016] A filter component, detachably mounted to the housing, has a filter covering the air inlet and a filter fixing portion for holding the filter and fixing it to the housing, the filter fixing portion being partially exposed to the battery assembly.

[0017] When the battery is assembled in the battery assembly part, the filter fixing part abuts against the battery to suppress the shaking of the battery relative to the housing.

[0018] In this power tool, the filter mounting part of the filter assembly functions as a component that contacts the battery to suppress battery sloshing. Therefore, by replacing the filter assembly, both the filter covering the air intake and the component used to suppress battery sloshing can be replaced at the same time.

[0019] Alternatively, it could be,

[0020] The battery assembly is configured to mount the battery by sliding it in a predetermined sliding direction. The air inlet has a first air inlet and a second air inlet formed on opposite sides of a direction orthogonal to the sliding direction.

[0021] The filter components are respectively installed at the first air inlet and the second air inlet, and the filter components installed at the first air inlet and the second air inlet have the same shape.

[0022] Alternatively, it could be,

[0023] The filter fixing part has: a frame portion surrounding and holding the filter, and a first mounting leg, a second mounting leg, and a third mounting leg protruding from the frame portion in the same direction, the first mounting leg, the second mounting leg, and the third mounting leg being arranged in an isosceles triangle, the isosceles triangle having the first mounting leg as the vertex and the second mounting leg and the third mounting leg as the vertices of the two base angles, and one of the first mounting leg, the second mounting leg, and the third mounting leg protruding from the battery assembly portion and abutting against the battery.

[0024] In addition, it could be,

[0025] The second mounting leg and the third mounting leg have flat surfaces that are chamfered in a direction orthogonal to the base of the isosceles triangle, facing the outer side of the isosceles triangle. When the battery is assembled into the battery assembly, the flat surface of one of the second mounting leg and the third mounting leg engages with the battery.

[0026] Alternatively, it could be,

[0027] The battery assembly is configured to mount the battery by sliding it in a predetermined sliding direction. The first mounting leg has a cylindrical shape, and when the battery is assembled in the battery assembly, the first mounting leg is pressed by the battery in the sliding direction.

[0028] Alternatively, it could be,

[0029] The power tool also features:

[0030] A motor, which is disposed within the housing; and

[0031] A fan, which is mounted on the rotating shaft of the motor.

[0032] As the fan rotates due to the motor, external air is drawn into the housing through the air inlet via the filter, passes around the motor, and is discharged from the housing. Attached Figure Description

[0033] Figure 1 This is a perspective view of a power tool (belt grinding tool) according to one embodiment of the present invention.

[0034] Figure 2 yes Figure 1 An exploded perspective view of a belt grinding tool.

[0035] Figure 3 yes Figure 1 A top-section view of a belt grinding tool.

[0036] Figure 4 yes Figure 1 A frontal perspective view of the motor unit of a belt grinding tool.

[0037] Figure 5 yes Figure 4 A rear 3D view of the motor unit.

[0038] Figure 6 yes Figure 4 A side sectional view of the motor unit.

[0039] Figure 7 yes Figure 1 A three-dimensional view of a belt grinding tool with a filter assembly, taken from the rear.

[0040] Figure 8 yes Figure 1 A three-dimensional view of a belt grinding tool with the filter component removed, taken from the rear.

[0041] Figure 9 This is a top view of the back side of the filter.

[0042] Figure 10 This is a partial sectional view of the area surrounding the battery assembly section when the battery is not installed.

[0043] Figure 11 This is a partial sectional view of the area surrounding the battery assembly section, with the battery installed in the assembly section.

[0044] Explanation of reference numerals in the attached figures

[0045] 100 Power tools, belt grinding tools; 102 Motor unit; 104 Drive unit; 106 Grip member; 108 Grip adapter; 110 Motor; 112 Grip part; 114 Motor housing; 116 Stator core; 118 Stator coil; 120 Rotor; 122 Rotating shaft; 124 Insulator; 126 Receiving recess; 128 Motor housing; 130 Opening; 132 Bracket; 134 Screw; 136 Bearing; 1 38 Fan; 140 Airflow guide component; 142 Base component; 144 Tie rod; 146 Idle pulley; 148 Drive pulley; 150 Spring; 152 Annular grinding belt; 154 Cover; 156 Housing part; 158 Extension part; 160 Grip fixing part; 160-1 Protrusion; 160-2 Annular locking groove; 162 End face; 164 Adapter fixing part; 166 Screw; 168 Switch; 170 First dividing component; 1 72 Second dividing member; 174 Fixing part; 174-1 Protrusion; 174-2 Annular protrusion; 176 Screw; 178 Battery assembly part; 180 Control circuit; 182 Grip fixing part; 182-1 Protrusion; 182-2 Annular locking groove; 184 Sliding groove; 186 Connecting terminal; 188 Air inlet (first and second air inlets); 190 Filter component; 192 Housing; 194 Exhaust port; 196 Filter; 198 Filter fixing part; 200 Frame part; 202-1 First mounting leg; 202-2 Second mounting leg; 202-3 Third mounting leg; 204 Flat surface; 204-1 First mounting part; 204-2 Second mounting part; 204-3 Third mounting part; 206 Inclined surface; 208 Vertical surface; B Battery; P1 First vertex; P2 Second vertex; P3 Third vertex; R Rotation axis; L Orthogonal axis. Detailed Implementation

[0046] Hereinafter, embodiments of the power tool of the present invention will be described with reference to the accompanying drawings.

[0047] like Figures 1 to 3 As shown, in one embodiment of the present invention, the power tool 100 is a battery-powered belt grinding tool 100 that drives an annular grinding belt to rotate for grinding operations.

[0048] The belt grinding tool 100 includes: a motor unit 102 with a built-in motor 110, a drive unit 104 mounted on the motor unit 102, a gripping member 106 forming a gripping part 112 for the operator to hold, and a gripping adapter 108 mounted between the motor unit 102 and the gripping member 106.

[0049] like Figures 4 to 6As shown in detail, the motor unit 102 mainly includes a motor 110 and a motor housing 114 that houses the motor 110. The motor 110 is a brushless motor and has a stator core 116 fixed to the motor housing 114, a stator coil 118 wound around the stator core 116, a rotor 120 disposed inside the stator core 116 and rotatable relative to the stator core 116 about a rotation axis R, and a rotation shaft 122 fixed to the rotor 120. The motor 110 also has an insulating member 124 disposed between the stator coil 118 and the stator core 116. The insulating member 124 is a resin component integrally molded with the stator core 116. The motor housing 114 consists of a motor housing 128 and a bracket 132. The motor housing 128 has a receiving recess 126 for accommodating the stator core 116 or rotor 120 of the motor 110. The bracket 132 is mounted on the motor housing 128 at the opening 130 side of the receiving recess 126. The bracket 132 is secured by four screws 134. Figure 4 The motor unit 102 is fixed to the motor housing 128, holding the motor 110 within the receiving recess 126. The rotating shaft 122, with its end protruding from the bracket 132, is held rotatably by two bearings 136 and fixed to the rotor 120, rotating together with it. The motor unit 102 also includes a fan 138 fixed to the rotating shaft 122 within the motor housing 114, and an airflow guide member 140 for directing the radially outward airflow generated by the fan 138 toward the bracket 132. The motor housing 128 is formed as a single, cup-shaped component made of resin. Typically, such housing components are formed from two separate components, but because the motor housing 128 of this invention is formed as a single component, it has higher strength compared to separate housing components and allows for more accurate centering of the rotor 120 and stator core 116.

[0050] like Figure 3 As shown, the drive unit 104 includes: a base member 142 fixed to the bracket 132 of the motor unit 102; a pull rod 144 mounted relative to the base member 142 in a manner capable of displacement in the longitudinal direction; a freewheeling pulley 146 rotatably mounted to the front end of the pull rod 144; and a drive pulley 148 fixed to the rotating shaft 122 of the motor unit 102. The pull rod 144 is directed forward by a spring 150 (in... Figure 3 (When observing from the left) Force is applied. Additionally, an annular grinding belt 152 is wound around the idle pulley 146 and the drive pulley 148. The annular grinding belt 152 is installed between the idle pulley 146 and the drive pulley 148 under tension due to the force of the spring 150. An openable and closable cover 154 is installed on the side of the base member 142 to cover the drive pulley 148.

[0051] like Figure 2As shown, the grip adapter 108 has a housing portion 156 that houses the motor housing 114, and an extension portion 158 extending rearward from the housing portion 156. A grip fixing portion 160 for mounting the gripping member 106 is provided in the extension portion 158. The grip fixing portion 160 is composed of a protrusion 160-1 protruding rearward from the extension portion 158 and an annular locking groove 160-2 formed on the outer peripheral surface of the extension portion 158. The grip adapter 108 is fixed to the adapter fixing portion 164 of the bracket 132 at the end face 162 of the housing portion 156 by four screws 166. Additionally, a switch 168 for starting / stopping the operation of the belt grinding tool 100 is installed in the grip adapter 108.

[0052] The gripping member 106 is composed of a first segmented member 170 and a second segmented member 172 formed separately. A fixing portion 174 is formed at the front end of the first segmented member 170 and the second segmented member 172, which is then mounted on the gripping fixing portion 160 of the gripping adapter 108. The fixing portion 174 is composed of a protrusion 174-1 and an annular protrusion 174-2. The protrusion 174-1 protrudes laterally inside the first segmented member 170 and the second segmented member 172, and the annular protrusion 174-2 protrudes radially inward from the front end of the first segmented member 170 and the second segmented member 172. With the protrusions 174-1 of the first dividing member 170 and the second dividing member 172 laterally clamping the protrusion 160-1 and the annular locking groove 160-2 locked by the annular protrusion 174-2, the first dividing member 170 and the second dividing member 172 are fixed to each other by five screws 176, thereby fixing the gripping member 106 to the gripping adapter 108. Two of the five screws 176 pass through the protrusions 174-1 of the first dividing member 170 and the second dividing member 172 and the protrusion 160-1 of the gripping member 106 and are tightened. A battery mounting portion 178 for mounting the battery B is formed at the rear end of the gripping member 106. In addition, a control circuit 180 for controlling the belt grinding tool 100 is built into the vicinity of the battery mounting portion 178.

[0053] Depend on Figure 4 as well as Figure 5 It can be seen that a gripping and fixing part 182, which has the same shape as the gripping and fixing part 160 of the gripping adapter 108, is formed at the rear end of the motor housing 114, and has a protrusion 182-1 and an annular locking groove 182-2. Therefore, it is possible to... Figure 1 In the illustrated scheme, the grip adapter 108 is removed from the motor housing 114, and the grip member 106 is directly installed on the motor housing 114.

[0054] like Figure 7As shown, the battery assembly 178 has a sliding groove 184 extending in the vertical direction and a connection terminal 186 for electrical connection with the battery B. The battery B is assembled into the battery assembly 178 and electrically connected to the connection terminal 186 by sliding downward along the sliding groove 184. Figure 3 as well as Figure 8 As shown, air inlets (first and second air inlets) 188 are formed on the left and right sides of the portion of the gripping member 106 that constitutes the battery assembly portion 178. In addition, filter members 190 are installed on each side to cover the air inlets 188.

[0055] In this belt grinding tool 100, the tool housing 192 is formed by the motor housing 114 of the motor unit 102, the grip adapter 108, and the grip member 106. When the fan 138 rotates due to the motor 110, external air is drawn into the housing 192 through the air inlet 188 of the housing 192 via the filter member 190. The drawn air flows within the housing 192 and around the motor 110, exiting through the exhaust port 194. Figure 3 , Figure 6 The airflow then dissipates the air. In this way, motor 110 is cooled by the airflow.

[0056] like Figure 8 as well as Figure 9 As shown, the filter component 190 has a filter 196 formed of a mesh member and a filter fixing portion 198 for fixing the filter 196 relative to the gripping member 106 constituting the housing 192. The filter fixing portion 198 has a frame portion 200 surrounding the filter 196 and maintaining the filter 196 in an isosceles triangular shape, and first to third mounting legs 202-1, 202-2, 202-3 extending from the vertices P1, P2, P3 of the frame portion 200 in a manner projecting in the same direction. The first mounting leg 202-1 is disposed at the first vertex P1 constituting the apex of the isosceles triangle, and the second and third mounting legs 202-2, 202-3 are disposed at the second vertex P2 and the third vertex P3 constituting the two base angles, respectively. The first mounting leg 202-1 has a cylindrical shape with a circular cross-section. The second and third mounting legs 202-2 and 202-3 have flat surfaces 204 that are chamfered in the vertical direction (orthogonal to the base of the isosceles triangle) facing the outer side of the isosceles triangle, and the cross-section is D-shaped. The two filter members 190 together are of the same shape, symmetrical from left to right. The frame portion 200 of the filter member 190 and the first to third mounting legs 202-1, 202-2, and 202-3 are formed, for example, of an elastic material such as rubber or resin.

[0057] like Figure 8As shown, a first mounting portion 204-1 for receiving a first mounting leg 202-1 of the filter component 190, a second mounting portion 204-2 for receiving a second mounting leg 202-2, and a third mounting portion 204-3 for receiving a third mounting leg 202-3 are provided around the air inlet 188 formed in the housing 192. The first mounting portion 204-1 and the second mounting portion 204-2 are formed as arc-shaped grooves extending laterally in the battery assembly portion 178. The third mounting portion 204-3 is formed as a circular hole extending laterally. The filter component 190 is detachably mounted to the grip member 106 by inserting the first to third mounting legs 202-1, 202-2, and 202-3 into the first to third mounting portions 204-1, 204-2, and 204-3, respectively. When the filter component 190 is mounted to the grip member 106, as shown... Figure 7 As shown, the first and second mounting legs 202-1 and 202-2 are partially exposed to the battery assembly 178. It should be noted that... Figure 7 as well as Figure 8 In this filter assembly 190, first to third mounting portions 204-1, 204-2, and 204-3 are also formed on the inner side. However, on this side, the second mounting leg 202-2 of the filter member 190 is inserted into the third mounting portion 204-3, which is a circular hole, and the third mounting leg 202-3 is inserted into the second mounting portion 204-2, which is an arc-shaped groove. Therefore, for the filter member 190 mounted on the inner side, the first and third mounting legs 202-1 and 202-3 are partially exposed to the battery assembly 178. In addition, the portion of the first mounting leg 202-1 exposed to the battery assembly 178 is different on the left and right sides of the filter member 190.

[0058] like Figure 10 As shown, for the first mounting leg 202-1 of the filter component 190, a portion of it protrudes from the inclined surface 206 of the battery assembly 178. Additionally, for the second mounting leg 202-2 (or the third mounting leg 202-3), a portion of its flat surface 204 slightly protrudes from the vertical surface 208 of the battery assembly 178. When the battery B is slid in the sliding direction (downward in the figure) and mounted on the battery assembly 178, the locking portion (not shown) of the battery B engages with the battery assembly 178, and the battery B is fixed to the battery assembly 178. At this time, as... Figure 11As shown, the first mounting leg 202-1 of the filter component 190 abuts against the battery B and is pressed flat by the battery B in the sliding direction. Furthermore, when the battery B is assembled into the battery assembly part 178, the second mounting leg 202-2 (or the third mounting leg 202-3) slides flattened on its flat surface 204, pressed against the battery B, thus maintaining engagement between the flat surface 204 and the battery B even when the battery B is assembled. In this way, the battery B, in the assembled state, contacts the first mounting leg 202-1 and the second mounting leg 202-2 (or the third mounting leg 202-3) of the filter component 190 in a pressed state. Therefore, vibrations or shaking of the battery B relative to the housing 192 are absorbed and suppressed by the first mounting leg 202-1 and the second mounting leg 202-2 (or the third mounting leg 202-3). That is, the first to third mounting legs 202-1, 202-2, and 202-3 of the filter member 190 formed by the elastic member function as elastic absorption members and can suppress the vibration or shaking of the battery B.

[0059] In this belt grinding tool 100, the mounting legs of the filter member 190 also function as elastic absorbing members to suppress vibration or swaying of the battery B. Therefore, by replacing the filter member 190, both the filter 196 and the elastic absorbing member for the battery B can be replaced simultaneously. This reduces the time required for replacement work and reduces the number of parts for easier part management. It should be noted that in the above embodiment, filter members 190 of the same shape are installed on both sides, allowing a filter member 190 installed on one side to be installed on the other side. For example, for the filter member 190 installed near the front side as seen in the figure, the second mounting leg 202-2 protrudes into the battery assembly 178, but if the filter member 190 is installed on the inside side, the third mounting leg 202-3 protrudes into the battery assembly 178. Similarly, the same applies to the first mounting leg 202-1; the portion hidden within the first mounting portion 204-1 when mounted near the front protrudes into the battery assembly portion 178 when mounted on the inner side. That is, even for the same filter member 190, the portion protruding into the battery assembly portion 178 differs depending on which side it is mounted on. Therefore, even if wear progresses on the exposed portions of the first to third mounting legs 202-1, 202-2, and 202-3, but the filter 196 remains usable, the filter member 190 can be mounted on the opposite side, allowing different portions of the first to third mounting legs 202-1, 202-2, and 202-3 to function as elastic absorption members to restore the sway suppression function, thereby enabling continued use of the filter member.

[0060] The embodiments of the present invention have been described above, but the present invention is not limited to these embodiments. For example, the shape of the filter member or the number and shape of the mounting legs can be appropriately changed. In addition, it is not necessary for two filter members mounted on opposite sides to be of the same shape. Furthermore, in the above embodiments, a belt grinding tool is shown as an example of a power tool, but the present invention can also be applied to other power tools such as grinding machines or chamfering machines.

Claims

1. A power tool driven by a detachably mounted storage battery, wherein, The power tool has the following features: The housing has a battery assembly and an air inlet; and A filter component, detachably mounted to the housing, has a filter covering the air inlet and a filter fixing portion for holding the filter and fixing it to the housing, the filter fixing portion being partially exposed to the battery assembly. When the battery is assembled in the battery assembly part, the filter fixing part functions as an elastic absorption member that elastically abuts against the battery to suppress the swaying of the battery relative to the housing.

2. The power tool according to claim 1, wherein, The battery assembly is configured to mount the battery by sliding it in a predetermined sliding direction. The air inlet has a first air inlet and a second air inlet formed on opposite sides of a direction orthogonal to the sliding direction. The filter components are respectively installed at the first air inlet and the second air inlet, and the filter components installed at the first air inlet and the second air inlet have the same shape.

3. The power tool according to claim 1, wherein, The filter fixing part has: a frame portion surrounding and holding the filter, and a first mounting leg, a second mounting leg, and a third mounting leg protruding from the frame portion in the same direction, the first mounting leg, the second mounting leg, and the third mounting leg being arranged in an isosceles triangle, the isosceles triangle having the first mounting leg as the vertex and the second mounting leg and the third mounting leg as the vertices of the two base angles, and one of the first mounting leg, the second mounting leg, and the third mounting leg protruding from the battery assembly portion and abutting against the battery.

4. The power tool according to claim 3, wherein, The second mounting leg and the third mounting leg have flat surfaces that are chamfered in a direction orthogonal to the base of the isosceles triangle, facing the outer side of the isosceles triangle. When the battery is assembled into the battery assembly, the flat surface of one of the second mounting leg and the third mounting leg engages with the battery.

5. The power tool according to claim 3, wherein, The battery assembly is configured to mount the battery by sliding it in a predetermined sliding direction. The first mounting leg has a cylindrical shape, and when the battery is assembled in the battery assembly, the first mounting leg is pressed by the battery in the sliding direction.

6. The power tool according to claim 1, wherein, The power tool also features: A motor, which is disposed within the housing; and A fan, which is mounted on the rotating shaft of the motor. As the fan rotates due to the motor, external air is drawn into the housing through the air inlet via the filter, passes around the motor, and is discharged from the housing.

Images