Power tools

Abstract

To provide a power tool which enables a member for inhibiting backlash of a battery and a filter to be replaced collectively.SOLUTION: A power tool (a belt type grinding tool) 100 is driven by a battery B detachably attached. The power tool includes: a housing 192 having a battery attachment part 178 and an intake port 188; and a filter member 190 detachably attached to the housing. The filter member has: a filter 196 configured to cover the intake port; and a filter fixing part 198 which holds the filter and is fixed to the housing. The filter fixing part has: a frame part 200 surrounding the filter; and first to third attachment leg parts 202-1 to 202-3 extending from the frame part. The first and second attachment leg parts 202-1, 202-2 partially protrude into the battery attachment part 178. The first and second attachment leg parts 202-1, 202-2 contact with the battery B to inhibit backlash of the battery against the housing 192.SELECTED DRAWING: Figure 8

Description

Technical Field

[0001] The present invention relates to a power tool driven by a battery.

Background Art

[0002] Power tools such as belt grinders and grinders that are driven using a detachable battery as a power source have been developed. Since such power tools generate vibration during operation, vibration countermeasures as required are applied to each part. In particular, since the detachably mounted battery is mounted with a certain amount of clearance relative to the battery mounting portion of the power tool, it is prone to vibrating relative to the battery mounting portion. As a result, the connection terminals of the power tool and the battery rub against each other and wear, making poor contact likely to occur. In addition, repeated separation and contact between the connection terminals of the power tool and the battery generates sparks between the terminals, which melts the resin part holding the metal terminals and shifts the position of the terminals, potentially leading to poor contact.

[0003] To prevent such vibration and rattling of the battery, for example, in Patent Document 1, an elastic absorbing member is fitted into the slide rail portion for mounting the battery, so that the battery is elastically supported by this elastic absorbing member to absorb vibration.

[0004] Further, in power tools, it may be necessary to cool the electric motor that generates heat during operation. For example, in Patent Document 2, a fan is attached to the rotating shaft of the motor disposed inside the housing, and the fan rotated by the motor draws external air into the housing, passes it around the motor, and exhausts it out of the housing, thereby cooling the motor. A filter for preventing dust and debris from entering the housing is disposed at the air intake port.

Prior Art Documents

Patent Documents

[0005] [Patent Document 1] Patent No. 6661328 [Patent Document 2] Patent No. 6252778 [Overview of the project] [Problems that the invention aims to solve]

[0006] The elastic vibration-absorbing material used to suppress battery vibrations gradually wears down with repeated battery removal and installation, and also deteriorates over time. Therefore, it needs to be replaced periodically. Similarly, the filter installed in the air intake gradually becomes dirty with use, and therefore also needs to be replaced periodically. However, since the elastic vibration-absorbing material and the filter are separate components installed in different locations, they must be replaced separately. This can make the replacement process complicated, and there is a risk that the elastic vibration-absorbing material, especially in an inconspicuous location, may be forgotten during replacement, resulting in a state where it cannot perform its necessary function.

[0007] Therefore, the present invention aims to provide a power tool that allows for the simultaneous replacement of a component for suppressing battery rattling and a filter. [Means for solving the problem]

[0008] In other words, the present invention is A power tool driven by a detachably mounted battery, A housing having a battery mounting section and an air intake, A filter member detachably attached to the housing, comprising a filter covering the air intake port and a filter fixing portion that holds the filter and fixes it to the housing, wherein the filter fixing portion is partially exposed to the battery mounting portion, Equipped with, The present invention provides a power tool in which, when the battery is mounted in the battery mounting section, the filter fixing section abuts against the battery to suppress rattling of the battery relative to the housing.

[0009] In this power tool, the filter fixing portion of the filter component contacts the battery and functions as a component to suppress battery rattle. Therefore, by replacing the filter component, it is possible to replace both the filter covering the air intake and the component that suppresses battery rattle at the same time.

[0010] Also, The battery mounting portion is configured such that the battery is mounted by sliding the battery in a predetermined sliding direction, and the air intake has a first air intake and a second air intake, which are formed on mutually opposite surfaces in a direction perpendicular to the sliding direction. The filter members are attached to the first air intake port and the second air intake port, respectively, and the filter members attached to the first air intake port and the second air intake port can be of the same shape.

[0011] Also, The filter fixing portion comprises a frame portion that surrounds the filter and holds the filter, and first to third mounting legs that protrude from the frame portion in the same direction, and the first to third mounting legs are arranged to form an isosceles triangle with the first mounting leg as the vertex of the apex angle and the second and third mounting legs as the vertices of the two base angles, so that the first mounting leg and one of the second and third mounting legs are exposed to the battery mounting portion and come into contact with the battery.

[0012] moreover, The second and third mounting legs have flat surfaces that are chamfered in a direction perpendicular to the base of the isosceles triangle so as to face the outside of the isosceles triangle, and when the battery is mounted in the battery mounting section, the flat surface of one of the second and third mounting legs can engage with the battery.

[0013] Also, The battery mounting portion is configured such that the battery is attached by sliding the battery in a predetermined sliding direction, the first mounting leg portion has a cylindrical shape, and when the battery is mounted on the battery mounting portion, the first mounting leg portion can be pressed by the battery in the sliding direction.

[0014] Furthermore, a motor disposed within the housing, a fan attached to a rotating shaft of the motor, is further included, when the fan is rotated by the motor, outside air can be drawn through the filter from the air intake port into the housing, pass around the motor, and be exhausted from the housing.

[0015] Hereinafter, an embodiment of the power tool according to the present invention will be described based on the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] [Figure 1] 1 is a perspective view of a power tool (belt-type grinding tool) according to an embodiment of the present invention. [Figure 2] 2 is an exploded perspective view of the belt-type grinding tool of FIG. 1. [Figure 3] 3 is a cross-sectional top view of the belt-type grinding tool of FIG. 1. [Figure 4] 4 is a front perspective view of a motor unit included in the belt-type grinding tool of FIG. 1. [Figure 5] 5 is a rear perspective view of the motor unit of FIG. 4. [Figure 6] 6 is a side cross-sectional view of the motor unit of FIG. 4. [Figure 7] 7 is a perspective view of the belt-type grinding tool of FIG. 1 as viewed from the rear in a state where a filter member is mounted. [Figure 8] 8 is a perspective view of the belt-type grinding tool of FIG. 1 as viewed from the rear in a state where the filter member is removed. [Figure 9]This is a plan view of the back side of the filter. [Figure 10] This is a partial cross-sectional view of the area surrounding the battery compartment when the battery is not installed in the battery compartment. [Figure 11] This is a partial cross-sectional view of the area surrounding the battery mounting section with the battery installed in the battery mounting section. [Modes for carrying out the invention]

[0017] As shown in Figures 1 to 3, the power tool 100 according to one embodiment of the present invention is a battery-powered belt-type grinding tool 100 that performs grinding work by rotating an endless grinding belt.

[0018] 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 that constitutes a grip portion 112 held by the operator, and a grip adapter 108 attached between the motor unit 102 and the grip member 106.

[0019] 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.

[0020] 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.

[0021] 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.

[0022] 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.

[0023] 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 which has a boss 182-1 and an annular locking groove 182-2, 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.

[0024] As shown in Figure 7, the battery mounting section 178 includes a sliding groove 184 extending in the vertical direction and a connection terminal 186 for electrically connecting to the battery B. The battery B is mounted in the battery mounting section 178 and electrically connected to the connection terminal 186 by sliding it downward along the sliding groove 184. As shown in Figures 3 and 8, air intake ports (first and second air intake ports) 188 are formed on the left and right sides of the portion of the grip member 106 that constitutes the battery mounting section 178. In addition, a filter member 190 is attached to each side so as to cover the air intake ports 188.

[0025] In the belt-type grinding tool 100, the tool housing 192 is composed of the motor case 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, outside air is drawn into the housing 192 through the filter member 190 and the intake port 188 of the housing 192. The drawn-in air flows inside the housing 192, passes around the motor 110, and is exhausted from the exhaust port 194 (Figures 3 and 4). In this way, the motor 110 is cooled by the airflow.

[0026] As shown in Figures 8 and 9, the filter member 190 has a filter 196 formed of a mesh-like member and a filter fixing part 198 for fixing the filter 196 to a grip member 106 that constitutes the housing 192. The filter fixing part 198 has an isosceles triangular frame part 200 that surrounds the filter 196 and holds the filter 196, and first to third mounting legs 202-1, 202-2, and 202-3 that extend in the same direction from each vertex P1, P2, and P3 of the frame part 200. The first mounting leg part 202-1 is positioned at the first vertex P1 which constitutes the vertex angle of the isosceles triangle, and the second and third mounting legs 202-2 and 202-3 are positioned at the second vertex P2 and the third vertex P3 which constitute the two base angles, respectively. The first mounting leg part 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 vertically (in a direction perpendicular to the base of the isosceles triangle) so as to face the outside of the isosceles triangle, and their cross-section is D-shaped. The two filter members 190 are both symmetrical and identical in shape. The frame portion 200 and the first to third mounting legs 202-1, 202-2, and 202-3 of the filter member 190 are formed from an elastic material such as rubber or resin.

[0027] As shown in Figure 8, around the intake port 188 formed in the housing 192, there are a first mounting portion 204-1 for receiving the first mounting leg portion 202-1 of the filter member 190, a second mounting portion 204-2 for receiving the second mounting leg portion 202-2, and a third mounting portion 204-3 for receiving the third mounting leg portion 202-3. The first mounting portion 204-1 and the second mounting portion 204-2 are formed as arc-shaped grooves that open into the battery mounting portion 178 and extend laterally. The third mounting portion 204-3 is formed as a circular hole that extends laterally. The filter member 190 is detachably attached 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 member 190 is attached to the grip member 106, as shown in Figure 7, the first and second mounting legs 202-1 and 202-2 are partially exposed to the battery mounting portion 178. In Figures 7 and 8, the first to third mounting portions 204-1, 204-2 and 204-3 are also formed on the rear side, but on that side, the second mounting leg 202-2 of the filter member 190 is inserted into the circular hole of the third mounting portion 204-3, and the third mounting leg 202-3 is inserted into the arc-shaped groove of the second mounting portion 204-2. Therefore, when the filter member 190 is attached to the rear side, the first and third mounting legs 202-1 and 202-3 are partially exposed to the battery mounting portion 178. Furthermore, the portion of the first mounting leg 202-1 that is exposed to the battery mounting portion 178 is different from the portion of the left and right filter members 190.

[0028] As shown in Figure 10, a portion of the first mounting leg 202-1 of the filter member 190 protrudes from the inclined surface 206 of the battery mounting portion 178. Also, the flat surface 204 of the second mounting leg 202-2 (or third mounting leg 202-3) protrudes slightly from the vertical surface 208 of the battery mounting portion 178. When the battery B is slid in the sliding direction (downward in the figure) and mounted on the battery mounting portion 178, the battery B's locking portion (not shown) engages with the battery mounting portion 178 and is fixed to the battery mounting portion 178. At this time, as shown in Figure 11, the first mounting leg 202-1 of the filter member 190 comes into contact with the battery B and is pressed and crushed by the battery B in the sliding direction. Furthermore, when the battery B is mounted in the battery mounting section 178, the second mounting leg 202-2 (or the third mounting leg 202-3) slides while being pressed and compressed by the battery B on its flat surface 204, and the flat surface 204 remains engaged with the battery B even when the battery B is mounted. In this way, when the battery B is mounted, it is in contact with the first mounting leg 202-1 and the second mounting leg 202-2 (or the third mounting leg 202-3) of the filter member 190 while being pressed against it, so that vibrations and rattles 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). In other words, the first to third mounting legs 202-1, 202-2, and 202-3 of the filter member 190, which is made of an elastic material, function as elastic absorbers, making it possible to suppress vibrations and rattles of the battery B.

[0029] In the belt-type grinding tool 100, the mounting legs of the filter member 190 also function as elastic absorbers to suppress vibration and rattle of the battery B. Therefore, by replacing the filter member 190, it is possible to replace both the filter 196 and the elastic absorbers for the battery B at the same time. This reduces the effort required for replacement work and simplifies parts management by reducing the number of parts. In the above embodiment, the same shaped filter member 190 can be attached to either the left or right side, and the filter member 190 that was attached to one side can be attached to the other side. For example, in the diagram, the filter member 190 that was attached to the front side had the second mounting leg 202-2 protruding into the battery mounting section 178, but if the filter member 190 is attached to the back side, then the third mounting leg 202-3 will protrude into the battery mounting section 178. Furthermore, when the first mounting leg 202-1 is mounted on the front side, the portion that is hidden within the first mounting portion 204-1 protrudes into the battery mounting portion 178 when mounted on the rear side. In other words, even with the same filter member 190, the portion that protrudes into the battery mounting portion 178 will differ depending on whether it is mounted on the left or right side. Therefore, if the exposed portions of the first to third mounting legs 202-1, 202-2, and 202-3 are worn but the filter 196 is still usable, the filter member 190 can be mounted on the opposite side, thereby restoring its rattle suppression function by utilizing the different portions of the first to third mounting legs 202-1, 202-2, and 202-3 as elastic absorbers, and the filter member can be used further.

[0030] Although embodiments of the present invention have been described above, the present invention is not limited to these embodiments. For example, the shape of the filter member and the number and shape of the mounting legs can be changed as appropriate. Also, the two filter members attached to opposite sides do not necessarily have to be the same shape. Furthermore, although a belt-type grinding tool is shown as an example of a power tool in the above embodiments, the present invention can also be applied to other types of power tools such as grinders and chamfering machines. [Explanation of symbols]

[0031] 100 Power tools, belt-driven grinding tools 102 Motor Unit 104 Drive Unit 106 Grip component 108 Grip Adapter 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 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 182-1 Boss 182-2 Annular locking groove 184 Slide groove 186 Connection terminals 188 Air intake ports (first and second air intake ports) 190 Filter component 192 Housing 194 Exhaust vent 196 filters 198 Filter fixing part 200 Frame section 202-1 First mounting leg 202-2 Second mounting leg 202-3 Third mounting leg 204 Flat surface 204-1 First mounting section 204-2 Second mounting section 204-3 Third mounting section 206 Slope 208 Vertical plane B Battery P1 First vertex P2, second vertex P3 Third Vertex R rotation axis L is an orthogonal axis.

Claims

1. A power tool driven by a detachably mounted battery, A housing having a battery mounting section and an air intake, A filter member detachably attached to the housing, comprising a filter covering the air intake port and a filter fixing portion that holds the filter and fixes it to the housing, wherein the filter fixing portion is partially exposed to the battery mounting portion, Equipped with, A power tool wherein the filter fixing portion is formed of an elastic material, a part of the filter fixing portion protrudes from the surface of the battery mounting portion, and when the battery is mounted in the battery mounting portion, the part of the filter fixing portion comes into contact with the battery and is pressed and crushed by the battery, thereby suppressing rattling of the battery relative to the housing.

2. The battery mounting portion is configured such that the battery is mounted by sliding the battery in a predetermined sliding direction, and the air intake has a first air intake and a second air intake, which are formed on mutually opposite surfaces in a direction perpendicular to the sliding direction. The power tool according to claim 1, wherein the filter members are attached to the first air intake port and the second air intake port, and the filter members attached to the first air intake port and the second air intake port are of the same shape.

3. The power tool according to claim 1, wherein the filter fixing portion comprises a frame portion that surrounds the filter and holds the filter, and first to third mounting legs that protrude from the frame portion in the same direction, and the first to third mounting legs are arranged to form an isosceles triangle with the first mounting leg as the vertex of the apex angle and the second and third mounting legs as the vertices of the two base angles, and the first mounting leg and one of the second and third mounting legs are exposed to the battery mounting portion and in contact with the battery.

4. The power tool according to claim 3, wherein the second and third mounting legs have flat surfaces that are chamfered in a direction perpendicular to the base of the isosceles triangle so as to face the outside of the isosceles triangle, and when the battery is mounted in the battery mounting portion, the flat surface of one of the second and third mounting legs engages with the battery.

5. The power tool according to claim 3, wherein the battery mounting portion is configured such that the battery is mounted by sliding the battery in a predetermined sliding direction, the first mounting leg portion has a cylindrical shape, and when the battery is mounted in the battery mounting portion, the first mounting leg portion is pressed in the sliding direction by the battery.

6. A motor arranged inside the housing, A fan attached to the rotating shaft of the motor, Furthermore, The power tool according to claim 1, wherein when the fan is rotated by the motor, external air is drawn into the housing through the filter and the intake port, and exhausted from the housing through the area around the motor.

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