Work machine
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- MAKITA CORP
- Filing Date
- 2023-08-25
- Publication Date
- 2026-08-05
Smart Images
Figure 00000000_0000_ABST
Abstract
Description
[Technical field]
[0001] The technology disclosed in this specification relates to a work machine. [Background technology]
[0002] Patent Document 1 discloses a work machine including an electric motor, a working mechanism driven by the electric motor, a base supporting the working mechanism, a rear housing rotatably attached to the rear of the base around a predetermined rotation axis and whose position relative to the base can be changed between a normal position and a rotational position rotated from the normal position around the rotation axis, a front handle that a user can hold with one hand, and a rear handle provided on the rear housing and that the user can hold with the other hand. [Prior art documents] [Patent documents]
[0003] [Patent Document 1] U.S. Patent Application Publication No. 2021 / 0107129 Summary of the Invention [Problem to be solved by the invention]
[0004] In the working machine of Patent Document 1, a battery pack for supplying power to the electric motor may be attached to the rear housing. However, if the battery pack is attached to the rear housing at a position offset from the rotation axis, the moment of inertia of the battery pack around the rotation axis may become excessively large. As a result, when a user changes the position of the rear housing relative to the base, a large force is required to rotate the rear housing together with the battery pack. As a result, the usability of the working machine may deteriorate. This specification provides a technology capable of improving the usability of the working machine. [Means for solving the problem]
[0005] The working machine disclosed in this specification includes an electric motor, a working mechanism driven by the electric motor, a base supporting the working mechanism, a rear housing rotatably attached to a rear part of the base about a predetermined rotation axis and whose position relative to the base can be changed between a normal position and a rotation position rotated from the normal position about the rotation axis, a front handle attached to the base and capable of being held by a user with one hand, a rear handle attached to the rear housing and capable of being held by the user with the other hand, and a battery attachment part attached to the rear housing and to which a battery pack for supplying power to the electric motor is detachably attached. When the battery pack is attached to the battery attachment part, the battery pack is disposed on the rotation axis.
[0006] According to the above configuration, the battery pack is attached to the rear housing so as to be disposed on the rotation axis. Therefore, the moment of inertia of the battery pack around the rotation axis is relatively small. This allows the user to rotate the rear housing together with the battery pack with a relatively small force. Therefore, the usability of the work machine can be improved. [Brief description of the drawings]
[0007] [Figure 1] FIG. 2 is a view of the hedge trimmer 2 according to the embodiment with the rear housing 12 in a normal position, as viewed from the upper front right. [Diagram 2] 2 is a view showing the internal structure of the hedge trimmer 2 according to the embodiment as viewed from the right. [Diagram 3] 2 is a diagram showing the internal structure of a rear housing 12 of a hedge trimmer 2 according to an embodiment, as viewed from the upper rear left side. FIG. [Figure 4] 2 is a diagram showing the internal structure of a rear housing 12 of a hedge trimmer 2 according to an embodiment, as viewed from the upper rear left side. FIG. [Diagram 5] FIG. 2 is a view of the hedge trimmer 2 according to the embodiment, with the rear housing 12 in a rotated position, as viewed from the upper front right. [Figure 6]FIG. 2 is an exploded view of a front portion of the hedge trimmer 2 according to the embodiment. [Figure 7] 2 is a perspective view of vibration-isolating members 90a, 90b, and 90c according to an embodiment. FIG. [Figure 8] 3A to 3C are side views of vibration-isolating members 90a, 90b, and 90c according to the embodiment. [Figure 9] 2 is a perspective view of vibration-isolating members 90a, 90b, and 90c according to an embodiment. FIG. [Figure 10] 3 is a perspective cross-sectional view of vibration-isolating members 90a, 90b, and 90c according to an embodiment. FIG. [Figure 11] 1 shows an example of a vibration isolation member 90a, a first mounting element 128, a second mounting element 134, and a third mounting element 140. FIG. [Figure 12] 1 is a diagram showing a state in which a vibration-isolating member 90a according to the embodiment is attached to a first mounting element 128, a second mounting element 134, and a third mounting element 140. FIG. [Figure 13] 13 shows an example vibration isolation member 90b, a first mounting element 146, a second mounting element 152, and a third mounting element 158. FIG. [Figure 14] 13 is a diagram showing an example of a vibration isolation member 90c, a first mounting element 164, a second mounting element 168, and a third mounting element 174. FIG. [Figure 15] 13 is a diagram showing a state in which a vibration-isolating member 90c according to the embodiment is attached to a first mounting element 164, a second mounting element 168, and a third mounting element 174. FIG. [Figure 16a] 9 is a diagram showing anti-vibration members 90a, 90b, and 90c according to the embodiment when viewed along cross section AA in FIG. 8. [Figure 16b] 9 is a diagram showing anti-vibration members 90a, 90b, and 90c according to the embodiment when viewed at cross section BB in FIG. 8. [Figure 16c] 9 is a diagram showing vibration-isolating members 90a, 90b, and 90c according to the embodiment when viewed at cross section CC in FIG. 8. [Figure 16d] 9 is a diagram showing anti-vibration members 90a, 90b, and 90c according to the embodiment when viewed along cross section DD in FIG. 8. [Figure 16e]9 is a diagram showing vibration-isolating members 90a, 90b, and 90c according to the embodiment when viewed along cross section EE in FIG. [Fig. 16f] 9 is a diagram showing anti-vibration members 90a, 90b, and 90c according to the embodiment when viewed along the cross section FF in FIG. 8. [Figure 17] 2 is a diagram showing a state in which a motor housing 22 of the hedge trimmer 2 according to the embodiment is disassembled. FIG. [Figure 18] 3 is an enlarged cross-sectional view showing a cooling air flow path F of the hedge trimmer 2 according to the embodiment. FIG. [Figure 19] 11 is a diagram showing the positional relationship between an air intake port 188 of a motor housing 22 and an exhaust port 196 of a rear housing 12 inside a passage portion 192 of a hedge trimmer 2 according to the embodiment. FIG. [Figure 20] 1 is a view of the rear housing 12 according to the embodiment and the battery pack B attached to a battery attachment portion 38 of the rear housing 12, as viewed in the axial direction of a rotation axis RA. [Figure 21] 11A to 11C are perspective views of vibration-isolating members 90a, 90b, and 90c according to modified examples. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0008] Representative and non-limiting examples of the present invention are described in detail below with reference to the drawings. This detailed description is intended simply to provide those skilled in the art with details for implementing the preferred embodiments of the present invention, and is not intended to limit the scope of the present invention. Additionally, the additional features and inventions disclosed can be used separately or together with other features and inventions to provide further improved working machines.
[0009] In addition, the combinations of features and steps disclosed in the following detailed description are not essential for implementing the present invention in the broadest sense, but are specifically described only to illustrate representative embodiments of the present invention. Furthermore, the various features of the following representative embodiments and the various features described in the claims do not have to be combined in the exact manner of the embodiments described herein or in the order listed in order to provide additional and useful embodiments of the present invention.
[0010] All features described in the specification and / or claims are intended to be disclosed individually and independently of one another as limitations to the specific features described in the original disclosure and claims, apart from the configuration of features described in the examples and / or claims. Furthermore, all numerical ranges and group or aggregate descriptions are intended to disclose intermediate configurations thereof as limitations to the specific features described in the original disclosure and claims.
[0011] In one or more embodiments, when the rear housing is in the normal position, the battery mounting portion may be provided at a rear portion of the rear housing.
[0012] When the user is holding the front and rear handles, if the center of gravity of the working machine is close to the user's body, the user can easily handle the working machine. However, the center of gravity of the working machine tends to be closer to the base side (i.e., the front side) that supports the working mechanism when viewed from the user's body holding the front and rear handles. According to the above configuration, since the battery pack is attached to the rear part of the rear housing, the weight of the battery pack can move the center of gravity of the working machine closer to the rear housing side (i.e., the rear side). This allows the center of gravity of the working machine to be closer to the body of the user holding the front and rear handles. Therefore, the user can easily handle the working machine.
[0013] In one or more embodiments, when the rear housing is in the normal position and the battery pack is attached to the battery mounting portion, the center of gravity of the battery pack may be located rearward of the rear end of the rear handle.
[0014] According to the above configuration, regardless of which part of the rear handle the user grips, the center of gravity of the battery pack is located behind the user's hand gripping the rear handle. In other words, the center of gravity of the battery pack is located behind the user's body. This makes it possible to more reliably bring the center of gravity of the work machine closer to the user's body.
[0015] In one or more embodiments, when the rear housing is in the normal position, the rear handle may be provided on an upper portion of the rear housing and extend along a front-to-rear direction. When the rear housing is in the normal position, the battery pack may be attached to the battery mounting portion by sliding the battery pack in a sliding direction from an upper rear portion to a lower front portion relative to the battery mounting portion.
[0016] The upper part of the rear housing where the rear handle is provided is the part that the user grips, and therefore needs to have a certain length in the front-rear direction. However, the lower part of the rear housing where the rear handle is not provided may be shorter in length in the front-rear direction. According to the above configuration, the battery mounting part provided at the rear of the rear housing has a shape that is inclined from the rear to the front as it goes from top to bottom. Therefore, the length of the upper part of the rear housing can be made relatively long in the front-rear direction, while the length of the lower part of the rear housing can be made relatively short.
[0017] In one or more embodiments, when the rear housing is in the normal position and the battery pack is attached to the battery mounting portion, the center of gravity of the work machine may be located rearward of the rear end of the front handle and forward of the front end of the rear handle.
[0018] If the center of gravity of the work machine is located between the front handle and the rear handle, the center of gravity of the work machine is closer to the body of a user who holds the front handle and the rear handle, which makes it easier for the user to handle the work machine.
[0019] In one or more embodiments, when the rear housing and the battery pack attached to the battery mounting portion are viewed along the axial direction of the rotation axis, the rear housing and the battery pack may be located within an imaginary circle having a radius of 13 cm centered on the rotation axis.
[0020] According to the above configuration, the moment of inertia around the rotation axis of the rear housing and the battery pack is small. This allows the user to rotate the rear housing together with the battery pack with little force, thereby improving the usability of the work machine.
[0021] In one or more embodiments, the base may include a front support part that supports the working mechanism, a rear support part that supports the working mechanism rearward of the front support part, and an arm part that passes along the side of the working mechanism to connect between the front support part and the rear support part.
[0022] According to the above configuration, the size of the base is compact, so that the base is less likely to interfere with the user's body or obstacles when the user uses the work machine, thereby improving the usability of the work machine.
[0023] In one or more embodiments, the arm portion may include a left arm portion that passes to the left of the working mechanism to connect between the front support portion and the rear support portion, and a right arm portion that passes to the right of the working mechanism to connect between the front support portion and the rear support portion.
[0024] If the front support part and the rear support part are connected by a single arm part, a large stress may act on the arm part while the user is using the work machine. If a large stress acts on the arm part, the arm part may deteriorate. According to the above configuration, the front support part and the rear support part are connected by the left arm part and the right arm part, so that the stress can be distributed between the left arm part and the right arm part. This makes it possible to prevent the left arm part and the right arm part from being subjected to a large stress, and therefore to prevent the left arm part and the right arm part from being deteriorated.
[0025] In one or more embodiments, the working mechanism may include a pair of blades extending along a front-rear direction. The pair of blades may be driven by the electric motor to reciprocate relatively in the front-rear direction.
[0026] According to the above configuration, the pair of blades may be disposed so as to extend forward as viewed from the front handle. In this case, the center of gravity of the work machine tends to be shifted toward the base (i.e., the front side). According to the above configuration, since the battery pack is attached to the rear part of the rear housing, the weight of the battery pack can shift the center of gravity of the work machine toward the rear housing (i.e., the rear side). This allows the center of gravity of the work machine to be closer to the body of the user who holds the front handle and the rear handle. This makes it easier for the user to handle the work machine.
[0027] (Example) As shown in Fig. 1, the working machine of this embodiment is a hedge trimmer 2. The hedge trimmer 2 is a gardening tool mainly used for pruning hedges and plants. The hedge trimmer 2 includes a working unit 4, a base 6 that supports the working unit 4, a front handle 8 provided on the base 6, a hand guard 10 that protects the hands of a user holding the front handle 8, a rear housing 12 attached to the rear of the base 6, and a rear handle 14 provided on the rear housing 12.
[0028] The work unit 4 includes a pair of shear blades 16. The pair of shear blades 16 extends linearly and has a plurality of cutting edges 18 along its longitudinal direction. The pair of shear blades 16 reciprocate with each other to prune hedges and plants with the plurality of cutting edges 18. In this embodiment, the longitudinal direction of the pair of shear blades 16, that is, the direction from the base 6 toward the pair of shear blades 16, is the forward direction, and the direction from the pair of shear blades 16 toward the base 6 is the rearward direction. In addition, the direction perpendicular to the front-rear direction and parallel to the plane in which the plurality of cutting edges 18 of the pair of shear blades 16 extend is the left-right direction. The direction perpendicular to the front-rear direction and the left-right direction, that is, the direction from the pair of shear blades 16 toward the hand guard 10 is the upward direction, and the direction from the hand guard 10 toward the pair of shear blades 16 is the downward direction.
[0029] The front handle 8 is provided at the front of the base 6, and has a generally U-shape that is open downward. The front handle 8 extends to the left, upper, and right of the base 6. The outer surface of the front handle 8 has a generally cylindrical shape. The rear handle 14 is provided at the top of the rear housing 12, and extends linearly in the front-to-rear direction. The outer surface of the rear housing 12 has a generally cylindrical shape. A user can carry the hedge trimmer 2 by holding the front handle 8 with one hand and the rear handle 14 with the other hand.
[0030] As shown in FIG. 2, the working unit 4 further includes an electric motor 20, a motor housing 22, a power transmission mechanism 24, and a mechanism housing 26. The electric motor 20 is, for example, an inner rotor type brushless motor including a stator 28, a rotor 30 disposed inside the stator 28, and an output shaft 32 fixed to the rotor 30. The electric motor 20 is accommodated in the motor housing 22. The motor housing 22 is fixed to the upper part of the mechanism housing 26. The output shaft 32 of the electric motor 20 is rotatably held in the motor housing 22 via a bearing 34, and is rotatably held in the mechanism housing 26 via a bearing 36. The output shaft 32 extends in the vertical direction and straddles between the motor housing 22 and the mechanism housing 26. The mechanism housing 26 accommodates the power transmission mechanism 24 and supports a pair of shear blades 16. The output shaft 32 of the electric motor 20 is connected to the pair of shear blades 16 via the power transmission mechanism 24. The power transmission mechanism 24 is, for example, a crank cam, and converts the rotational motion of the output shaft 32 into the reciprocating motion of each of the pair of shear blades 16. The reciprocating directions of the pair of shear blades 16 are aligned along the front-rear direction.
[0031] A battery mounting portion 38 for detachably mounting a battery pack B is provided at the rear of the rear housing 12. The battery pack B is mounted on the battery mounting portion 38 by sliding it in a sliding direction SD from the upper rear to the lower front relative to the battery mounting portion 38. The inclination angle θ1 of the sliding direction SD with respect to the front-rear direction is in the range of 45 degrees to 90 degrees, for example, when the clockwise direction as viewed from the right is taken as positive, and is 60 degrees in this embodiment.
[0032] A control device 40 that controls each part of the hedge trimmer 2 is accommodated in the lower part of the rear housing 12. The control device 40 includes a control board 42 and a controller case 44 that accommodates the control board 42. The control board 42 is equipped with, for example, a microcomputer composed of a CPU, a ROM, and a RAM, and an inverter circuit composed of a plurality of switching elements (for example, FETs). The control device 40 can convert DC power supplied from the battery pack B into three-phase AC power and supply it to the electric motor 20. The control device 40 has a generally flat plate shape that extends in the left-right direction. The control device 40 is arranged so that its longitudinal direction is along the front-rear direction.
[0033] The rear housing 12 includes a shaft portion 46 having a substantially cylindrical shape. The shaft portion 46 is provided at the front of the rear housing 12. The base 6 includes a shaft holding portion 48 that holds the shaft portion 46 rotatably about a rotation axis RA. The shaft holding portion 48 is provided at the rear of the base 6. The rotation axis RA is on a plane perpendicular to the left-right direction, and is inclined from top to bottom as it moves from rear to front. The inclination angle θ2 of the rotation axis RA with respect to the front-rear direction is, for example, within a range of 0 degrees to 30 degrees, and is 10 degrees in this embodiment, when the clockwise direction is positive as viewed from the right. The rotation axis RA extends so as to pass through the battery pack B attached to the battery mounting portion 38. That is, the battery pack B attached to the battery mounting portion 38 is disposed on the rotation axis RA.
[0034] As shown in FIG. 3, the shaft holding portion 48 includes a cylindrical surface 50 that rotatably holds the outer circumferential surface of the shaft portion 46, and a plurality of engagement grooves 52 (some of which are not shown) that are formed by recessing the cylindrical surface 50 toward the radially outward direction of the rotation axis RA (see FIG. 2). In this embodiment, five engagement grooves 52 are provided. Each of the engagement grooves 52 extends along the rotation axis RA. The engagement grooves 52 are arranged at predetermined intervals (for example, intervals of 1 / 8 of a circumference) in the circumferential direction of the rotation axis RA. In addition, the rear housing 12 is provided with a rotation lock member 54 that locks the rotation of the shaft portion 46 relative to the base 6 (i.e., the rotation of the rear housing 12 relative to the base 6). The rotation lock member 54 includes a lock piece 56 that extends along the rotation axis RA. The shaft portion 46 includes an accommodation groove 58 that is recessed radially inward from the outer circumferential surface of the shaft portion 46 and can accommodate the lock piece 56. The accommodation groove 58 extends along the rotation axis RA. In a state where the accommodation groove 58 and the engagement groove 52 face each other in the radial direction of the rotation axis RA, the rotation lock member 54 is slidable between a locked position where the lock piece 56 enters the engagement groove 52 as shown in FIG. 3 and an unlocked position where the lock piece 56 enters the accommodation groove 58 as shown in FIG. 4. An operating unit 60 is fixed to the rotation lock member 54. As shown in FIGS. 1 and 5, the operating unit 60 is exposed on the left and right outer surfaces of the rear housing 12 and is slidable along the outer surface of the rear housing 12. A user can slide the rotation lock member 54 by operating the operating unit 60. As shown in FIGS. 3 and 4, a coil spring 62 is attached to the rotation lock member 54. The lower end of the coil spring 62 abuts against a support protrusion 63 (see FIG. 2) formed on the inner wall of the rear housing 12. The coil spring 62 urges the rotation lock member 54 upward against the support protrusion 63. 3 by the biasing force of the coil spring 62. When the rotation lock member 54 is in the locked position, the rear housing 12 is mechanically locked with respect to the base 6, and rotation of the rear housing 12 with respect to the base 6 is prohibited.From this state, when the user presses down the operation unit 60 against the biasing force of the coil spring 62, the rotation lock member 54 moves to the unlocked position shown in Fig. 4. When the rotation lock member 54 is in the unlocked position, the rear housing 12 is unlocked from the base 6, and rotation of the rear housing 12 with respect to the base 6 is permitted.
[0035] The user can change the position of the rear housing 12 with respect to the base 6 by rotating the rear housing 12 with the rotation lock member 54 moved to the unlocked position and engaging the lock piece 56 with another engagement groove 52. This allows the position of the rear housing 12 to be changed from the normal position shown in Fig. 1 to, for example, a rotated position as shown in Fig. 5. In the following, unless otherwise specified, it is assumed that the rear housing 12 is in the normal position shown in Fig. 1.
[0036] As shown in FIG. 3, the rear housing 12 is provided with an operation button 64, a trigger lever 66, and a lock-off lever 68. The operation button 64 is disposed on the upper surface of the rear handle 14. By operating the operation button 64, a user can switch the main power supply of the hedge trimmer 2 on and off, change the rotation speed of the electric motor 20, drive the electric motor 20 in reverse rotation, and the like. The trigger lever 66 is disposed at the lower part of the rear handle 14 at a position where it can be operated by the index finger of the hand holding the rear handle 14. The lock-off lever 68 is disposed at the upper part of the rear handle 14 at a position where it can be operated by the palm of the hand holding the rear handle 14. The trigger lever 66 is usually mechanically locked by the lock-off lever 68. When the lock-off lever 68 is pressed in, the lock of the trigger lever 66 is released, and the trigger lever 66 is allowed to be pulled up. When the trigger lever 66 is pulled up, a microswitch 70 housed inside the rear housing 12 is pressed down. When the microswitch 70 is pressed while the main power supply of the hedge trimmer 2 is on, the control device 40 operates the electric motor 20 to drive the pair of shear blades 16. When the pulling up operation of the trigger lever 66 is released from this state, the microswitch 70 is no longer pressed. When the microswitch 70 is no longer pressed, the control device 40 stops the electric motor 20 and stops the pair of shear blades 16. Therefore, with the main power supply of the hedge trimmer 2 on, the user can press in the lock-off lever 68 and pull up the trigger lever 66 to drive the pair of shear blades 16.
[0037] A slider 540 that is held by the rear housing 12 to be slidable in the front-rear direction is connected to the rotation lock member 54. The rotation lock member 54 and the slider 540 are connected by inserting a pin 542 formed in the rotation lock member 54 into an elongated hole 544 formed in the slider 540. When the rotation lock member 54 slides, the pin 542 moves along the elongated hole 544, and the slider 540 slides. The slider 540 also has a notched groove 546 formed by cutting out the rear part of the slider 540. The trigger lever 66 has a protrusion 548 that can enter the notched groove 546. As shown in FIG. 3, when the rotation lock member 54 is in the locked position, the slider 540 is in a position that does not mechanically interfere with the trigger lever 66. 4, when the rotation lock member 54 moves to the unlocked position, the slider 540 moves rearward and the protrusion 548 formed on the trigger lever 66 enters the notched groove 546. This mechanically locks the trigger lever 66. As a result, when the user changes the position of the rear housing 12 relative to the base 6, the trigger lever 66 becomes inoperable and the pair of shear blades 16 is prohibited from being driven.
[0038] As shown in FIG. 6, the base 6 is composed of a base body 72, a handle member 74, a semi-cylinder member 76, and a plate member 78. The base body 72, the handle member 74, the semi-cylinder member 76, and the plate member 78 are fixed to each other by screws (not shown). The handle member 74 is a member that defines the front handle 8 and the hand guard 10. The base 6 also includes a left support part 80 that supports the left part of the mechanism housing 26 via a vibration-isolating member 90a, a right support part 82 that supports the right part of the mechanism housing 26 via a vibration-isolating member 90b, a rear support part 84 that supports the rear part of the mechanism housing 26 via a vibration-isolating member 90c, a left arm part 86 that passes through the left side of the mechanism housing 26 to connect between the left support part 80 and the rear support part 84, and a right arm part 88 that passes through the right side of the mechanism housing 26 to connect between the right support part 82 and the rear support part 84.
[0039] (Vibration-proof members 90a, 90b, 90c) As shown in FIG. 7, the vibration-proof members 90a, 90b, and 90c have a substantially rectangular parallelepiped shape. The vibration-proof members 90a, 90b, and 90c are made of a rubber material (e.g., silicone rubber). The vibration-proof members 90a, 90b, and 90c are manufactured by, for example, injection molding. In this embodiment, the length direction, width direction, and height direction of the vibration-proof members 90a, 90b, and 90c are defined as the X direction, Y direction, and Z direction. The dimension of the vibration-proof members 90a, 90b, and 90c in the X direction is, for example, within a range of 20 mm to 70 mm, and is 50 mm in this embodiment. The dimension of the vibration-proof members 90a, 90b, and 90c in the Y direction is, for example, within a range of 10 mm to 30 mm, and is 15 mm in this embodiment. The dimension of the vibration-proof members 90a, 90b, and 90c in the Z direction is, for example, within a range of 10 mm to 40 mm, and is 25 mm in this embodiment. The vibration-isolating members 90a, 90b, and 90c are symmetrical with respect to the X and Z directions. Therefore, the following description of the vibration-isolating members 90a, 90b, and 90c will still be valid if the positive and negative signs in the X and Z directions are reversed.
[0040] The vibration-isolating members 90a, 90b, and 90c have common components, and therefore, in the following description, the components of the vibration-isolating members 90a, 90b, and 90c will be denoted by common reference numerals.
[0041] As shown in Fig. 8, the vibration-proof members 90a, 90b, and 90c include a first attachment portion 92, a second attachment portion 94 offset in the negative Z direction from the first attachment portion 92, a third attachment portion 96 offset in the negative Z direction from the second attachment portion 94, a first connection portion 98 connecting the first attachment portion 92 and the second attachment portion 94, and a second connection portion 100 connecting the first attachment portion 92 and the third attachment portion 96. A first groove 102 is formed in the outer surface of the vibration-proof members 90a, 90b, and 90c at a location corresponding to the outer surface of the first connection portion 98. A second groove 104 is formed in the outer surface of the vibration-proof members 90a, 90b, and 90c at a location corresponding to the outer surface of the second connection portion 100. The first groove 102 and the second groove 104 extend over the entire circumference of the vibration-proof members 90a, 90b, and 90c in the XY plane, respectively.
[0042] 7, the first mounting portion 92 has a plate shape extending along the XY plane. The first mounting portion 92 has a mounting surface 106 facing the positive Z direction, and a plurality of mounting holes 108 formed by recessing the mounting surface 106 in the negative Z direction. Each of the plurality of mounting holes 108 is an elongated hole having a longitudinal direction in the X direction.
[0043] The second mounting portion 94 has a substantially rectangular parallelepiped shape with the length direction being the X direction, the width direction being the Y direction, and the height direction being the Z direction. The second mounting portion 94 includes an end surface 110 facing the positive Y direction, a mounting recess 112 formed by recessing the end surface 110 in the negative Y direction, a plurality of mounting holes 114 formed by recessing the wall surface of the mounting recess 112 in the negative Z direction, a plurality of mounting holes 116 (see FIG. 9) formed by recessing the wall surface of the mounting recess 112 in the positive Z direction, and a plurality of lightening holes 118 formed by penetrating the bottom surface of the mounting recess 112 in the negative Y direction. As shown in FIG. 10, the plurality of mounting holes 116 are connected to the plurality of mounting holes 108 of the first mounting portion 92 via hollow spaces 120 formed inside the first connecting portion 98. In this embodiment, the wall surface defining the multiple mounting holes 116, the wall surface defining the hollow space 120, and the wall surface defining the multiple mounting holes 108 are smoothly connected to each other.
[0044] As shown in FIG. 9, the third mounting portion 96 has a plate shape extending along the XY plane, similar to the first mounting portion 92. The third mounting portion 96 has a mounting surface 122 facing the negative Z direction and a plurality of mounting holes 124 formed by recessing the mounting surface 122 in the positive Z direction. Each of the plurality of mounting holes 124 is an elongated hole having a longitudinal direction in the X direction. As shown in FIG. 10, the plurality of mounting holes 124 are connected to the plurality of mounting holes 114 of the second mounting portion 94 through a hollow space 126 formed inside the second connection portion 100. In this embodiment, the wall surface defining the plurality of mounting holes 124, the wall surface defining the hollow space 126, and the wall surface defining the plurality of mounting holes 114 are smoothly connected.
[0045] As shown in FIG. 11, the vibration-proof member 90a is disposed so that the positive X direction corresponds to the forward direction, the positive Y direction corresponds to the rightward direction, and the positive Z direction corresponds to the upward direction. The first mounting portion 92 is attached to a first mounting element 128 provided on the left part of the handle member 74. The first mounting element 128 has a support surface 130 facing downward (negative Z direction) and a plurality of mounting protrusions 132 protruding downward (negative Z direction) from the support surface 130. The plurality of mounting protrusions 132 each have a shape that can be fitted into the plurality of mounting holes 108. As shown in FIG. 12, the first mounting portion 92 is attached to the first mounting element 128 by fitting the plurality of mounting protrusions 132 into the plurality of mounting holes 108 and abutting the mounting surface 106 against the support surface 130. The second mounting portion 94 shown in FIG. 11 is attached to a second mounting element 134 provided on the left part of the mechanism housing 26 (see FIG. 6). The second mounting element 134 includes a mounting frame 136 protruding leftward (negative Y direction) from the outer surface of the mechanism housing 26, and a plurality of mounting projections 138 protruding upward (positive Z direction) from the upper surface of the mounting frame 136. The mounting frame 136 has a shape that can be fitted into the mounting recess 112. The plurality of mounting projections 138 each have a shape that can be fitted into the plurality of mounting holes 116 (see FIG. 9). As shown in FIG. 12, the second mounting portion 94 is attached to the second mounting element 134 by fitting the mounting frame 136 into the mounting recess 112 and fitting the plurality of mounting projections 138 into the plurality of mounting holes 116. The third mounting portion 96 shown in FIG. 11 is attached to a third mounting element 140 provided on the left arm portion 86. The third mounting element 140 has a support surface 142 facing upward (positive direction in the Z direction) and a plurality of mounting protrusions 144 protruding upward (positive direction in the Z direction) from the support surface 142. The plurality of mounting protrusions 144 each have a shape that can be fitted into a plurality of mounting holes 124 (see FIG. 9). As shown in FIG. 12, the third mounting part 96 is attached to the third mounting element 140 by fitting the plurality of mounting protrusions 144 into the plurality of mounting holes 124 and abutting the mounting surface 122 against the support surface 142. The vibration-proof member 90a is usually sandwiched between the base main body 72 and the handle member 74 and compressed in the vertical direction (Z direction).
[0046] As shown in FIG. 13, the vibration-proof member 90b is disposed so that the positive X-direction is the rearward direction, the positive Y-direction is the leftward direction, and the positive Z-direction is the upward direction. The first mounting portion 92 is attached to a first mounting element 146 provided on the right portion of the handle member 74. The first mounting element 146 has a support surface 148 and a plurality of mounting protrusions 150. The second mounting portion 94 is attached to a second mounting element 152 provided on the right portion of the mechanism housing 26 (see FIG. 6). The second mounting element 152 has a mounting frame 154 and a plurality of mounting protrusions 156. The third mounting portion 96 is attached to a third mounting element 158 provided on the right arm portion 88. The third mounting element 158 has a support surface 160 and a plurality of mounting protrusions 162. The first mounting element 146, the second mounting element 152, and the third mounting element 158 have substantially the same shapes as the above-described first mounting element 128, the second mounting element 134, and the third mounting element 140. Therefore, detailed description of the first mounting element 146, the second mounting element 152, and the third mounting element 158 will be omitted. The vibration-proof member 90b is usually sandwiched between the base main body 72 and the handle member 74, and compressed in the up-down direction (Z direction).
[0047] As shown in FIG. 14, the vibration-proof member 90c is disposed so that the positive X-direction is the leftward direction, the positive Y-direction is the forward direction, and the positive Z-direction is the upward direction. The first mounting portion 92 is attached to a first mounting element 164 provided on the plate member 78. The first mounting element 164 has a support surface 166 (i.e., the lower surface of the plate member 78). Unlike the above-mentioned first mounting elements 128 and 146, the first mounting element 164 does not have protrusions that enter the multiple mounting holes 108 of the first mounting portion 92. As shown in FIG. 15, the first mounting portion 92 is attached to the first mounting element 164 by abutting the mounting surface 106 against the support surface 166. The second mounting portion 94 is attached to a second mounting element 168 provided at the rear of the mechanism housing 26 (see FIG. 6). The second mounting element 168 has a mounting frame 170 and multiple mounting protrusions 172. The third mounting portion 96 is attached to a third mounting element 174 provided at the rear of the base main body 72. The third mounting element 174 has a support surface 176 and a plurality of mounting projections 178. The second mounting element 168 and the third mounting element 174 have substantially the same shapes as the second mounting elements 134, 152 and the third mounting elements 140, 158 described above. For this reason, detailed description of the second mounting element 168 and the third mounting element 174 will be omitted. The vibration-proof member 90c is usually sandwiched between the base main body 72 and the plate member 78 and compressed in the up-down direction (Z direction).
[0048] 8 is an area located on the negative side in the Z direction from the mounting surface 106 and on the positive side in the Z direction from the wall surface on the positive side in the Z direction of the mounting recess 112. Vibrations of one of the first mounting elements 128, 146, 164 (see FIG. 6) and the second mounting elements 134, 152, 168 (see FIG. 6) are transmitted mainly via the first vibration isolation area A1 to the other of the first mounting elements 128, 146, 164 and the second mounting elements 134, 152, 168. The second vibration isolation area A2 is an area located on the positive side in the Z direction from the mounting surface 122 and on the negative side in the Z direction from the wall surface on the negative side in the Z direction of the mounting recess 112. Vibrations of one of the second mounting elements 134, 152, 168 and the third mounting elements 140, 158, 174 (see FIG. 6) are transmitted to the other of the second mounting elements 134, 152, 168 and the third mounting elements 140, 158, 174 mainly via the second vibration isolation area A2.
[0049] The cross section AA shown in FIG. 16a is a cross section perpendicular to the Z direction of a portion of the first vibration isolation region A1 that corresponds to the first mounting portion 92. The cross section BB shown in FIG. 16b is a cross section perpendicular to the Z direction of a portion of the first vibration isolation region A1 that corresponds to the first connecting portion 98. The cross section CC shown in FIG. 16c is a cross section perpendicular to the Z direction of a portion of the first vibration isolation region A1 that corresponds to the second mounting portion 94. The cross section DD shown in FIG. 16d is a cross section perpendicular to the Z direction of a portion of the second vibration isolation region A2 that corresponds to the second mounting portion 94. The cross section EE shown in FIG. 16e is a cross section perpendicular to the Z direction of a portion of the second vibration isolation region A2 that corresponds to the second connecting portion 100. The cross section FF shown in FIG. 16f is a cross section perpendicular to the Z direction of a portion of the second vibration isolation region A2 that corresponds to the third mounting portion 96. If the cross-sectional area of the cross section AA is Sa, the cross-sectional area of the cross section BB is Sb, the cross-sectional area of the cross section CC is Sc, the cross-sectional area of the cross section DD is Sd, the cross-sectional area of the cross section EE is Se, and the cross-sectional area of the cross section FF is Sf, then in this embodiment, the relationship of magnitude Sa=Sc=Sd=Sf>Sb=Se is established. This relationship of magnitude can also be regarded as the relationship of magnitude of the shear stiffness in each cross section. Therefore, in the first vibration isolation region A1, the first connection portion 98 is more susceptible to shear deformation in the X direction and the Y direction than the first attachment portion 92 and the second attachment portion 94. In the second vibration isolation region A2, the second connection portion 100 is more susceptible to shear deformation in the X direction and the Y direction than the second attachment portion 94 and the third attachment portion 96.
[0050] When the pair of shear blades 16 shown in Fig. 6 are driven, the working unit 4 vibrates in the front-rear direction (X direction as viewed from the vibration-isolating members 90a, 90b, Y direction as viewed from the vibration-isolating member 90c) in accordance with the reciprocating motion of each of the pair of shear blades 16. In this case, the vibration of the working unit 4 is transmitted to the base 6 via the second mounting elements 134, 152, 168, the first vibration-isolating area A1 (see Fig. 8) of the vibration-isolating members 90a, 90b, 90c, and the first mounting elements 128, 146, 164 in this order. The vibration of the working unit 4 is also transmitted to the base 6 via the second mounting elements 134, 152, 168, the second vibration-isolating area A2 (see Fig. 8) of the vibration-isolating members 90a, 90b, 90c, and the third mounting elements 140, 158, 174 in this order. However, the vibration transmitted to the base 6 is reduced by the first connection portion 98 being largely sheared in the front-rear direction in the first vibration isolation region A1 of the vibration isolation members 90a, 90b, 90c, and the second connection portion 100 being largely sheared in the front-rear direction in the second vibration isolation region A2 of the vibration isolation members 90a, 90b, 90c. Note that there is no constraint by the recess and the protrusion between the vibration isolation member 90c and the first mounting element 164, and the force (i.e., vibration) is transmitted only by the friction between the mounting surface 106 and the support surface 166. For this reason, it can be considered that the vibration is substantially insulated between the vibration isolation member 90c and the first mounting element 164.
[0051] (Hedge trimmer 2 cooling structure) As shown in FIG. 17 , the motor housing 22 is composed of a left housing member 180 and a right housing member 182. The left housing member 180 and the right housing member 182 are fixed to each other by screws (not shown). A motor support frame 184 is formed on the inner wall of the motor housing 22. The motor support frame 184 supports the electric motor 20 by abutting against the outer surface of the stator 28. The motor support frame 184 is divided into a portion formed in the left housing member 180 and a portion (not shown) formed in the right housing member 182. When the motor housing 22 is removed, the outer surface of the stator 28 is exposed to the outside of the hedge trimmer 2.
[0052] As shown in Fig. 18, the motor housing 22 includes a duct portion 186 extending rearward when viewed from the electric motor 20, an air intake port 188 formed at the rear end of the duct portion 186, an exhaust port 190L formed on the left side of the motor housing 22, and an exhaust port 190R (see Fig. 17) formed on the right side of the motor housing 22. The air intake port 188 opens into a passage portion 192 provided in the base 6. The exhaust ports 190R, 190L each open to the outside of the hedge trimmer 2.
[0053] The rear housing 12 is provided with a through hole 194 that passes through the inside of the shaft portion 46 to connect the inside and outside of the rear housing 12, an exhaust port 196 that corresponds to the front opening of the through hole 194, an air intake port 198L formed in the left surface of the rear housing 12, and an air intake port 198R (see FIG. 1) formed in the right surface of the rear housing 12. The exhaust port 196 opens into the inside of a passage portion 192 provided in the base 6. The air intake ports 198L and 198R each open to the outside of the hedge trimmer 2.
[0054] The passage 192 is provided in front of the shaft holding part 48. The passage 192 and the shaft holding part 48 are formed across the base body 72 and the semi-cylindrical member 76. An opening 200 is provided at the front end of the passage 192, into which the duct part 186 of the motor housing 22 is inserted. A gap 202 is provided between the outer surface of the duct part 186 and the periphery of the opening 200. If the gap 202 was not provided, the motor housing 22 would abut against the semi-cylindrical member 76, and the vibration of the working unit 4 would be directly transmitted to the base 6. By providing the gap 202, the motor housing 22 is prevented from abutting against the semi-cylindrical member 76, and the vibration of the working unit 4 is suppressed from being directly transmitted to the base 6. However, a dustproof member (not shown) that closes the gap 202 is provided in the gap 202. A member (e.g., a sponge) that has a property of not easily transmitting vibrations is used as the dustproof member. This prevents dust and other debris from entering the inside of the hedge trimmer 2 through the gap 202.
[0055] The hedge trimmer 2 includes a cooling air flow path F that extends from the outside of the hedge trimmer 2 through the air intakes 198L and 198R of the rear housing 12, the inside of the rear housing 12, the exhaust port 196 of the rear housing 12, the inside of the passage portion 192, the air intake 188 of the motor housing 22, the inside of the motor housing 22, and the exhaust ports 190R and 190L of the motor housing 22 to the outside of the hedge trimmer 2. In this embodiment, a fan 204 that generates an air flow (also simply called cooling air) along the cooling air flow path F is fixed to the output shaft 32. The fan 204 is disposed below the rotor 30 at a position overlapping the exhaust ports 190R and 190L when viewed in the left-right direction. When the electric motor 20 operates, the fan 204 rotates together with the output shaft 32, and cooling air is generated in the cooling air flow path F.
[0056] The cooling air flow path F includes a first flow path portion F1 through which air flows from the air intake ports 198L, 198R toward the front lower portion of the rear housing 12, a second flow path portion F2 through which air flows from the front lower portion of the rear housing 12 through the through hole 194 toward the exhaust port 196, a third flow path portion F3 through which air flows from the exhaust port 196 through the inside of the passage portion 192 toward the air intake port 188, a fourth flow path portion F4 through which air flows from the air intake port 188 through the inside of the duct portion 186 toward the front, a fifth flow path portion F5 through which air flows along the rear surface of the motor support frame 184 toward the upper portion of the motor housing 22, and a sixth flow path portion F6 through which air flows from the upper portion of the motor housing 22 through between the stator 28 and the rotor 30 of the electric motor 20 toward the exhaust ports 190R, 190L.
[0057] The control device 40 is disposed in the first flow path portion F1. The first flow path portion F1 extends along the longitudinal direction (i.e., the front-rear direction) of the control device 40. The air intake ports 198L, 198R of the rear housing 12 are disposed rearward of the rear end of the control device 40. Therefore, the control device 40 can be cooled from the rear end to the front end by the cooling air flowing through the first flow path portion F1.
[0058] 19, when the inside of the passage portion 192 is viewed in the front-rear direction, the air intake port 188 of the motor housing 22 and the exhaust port 196 of the rear housing 12 overlap each other. This allows the cooling air to flow smoothly in the third flow path portion F3.
[0059] Although not shown, electrical wiring is arranged in the cooling air flow path F to connect between the electrical components housed in the rear housing 12 and the electrical components housed in the motor housing 22. For example, electrical wiring is arranged in the cooling air flow path F to electrically connect between the control device 40 housed in the rear housing 12 and the electric motor 20 housed in the motor housing 22.
[0060] 20 shows the rear housing 12, the battery pack B attached to the battery attachment portion 38 of the rear housing 12, and an imaginary circle VC centered on the rotation axis RA. The radius of the imaginary circle VC is within a range of 5 cm to 15 cm, for example, and is 13 cm in this embodiment. When viewed from the axial direction of the rotation axis RA, the rear housing 12 and the battery pack B are located inside the imaginary circle VC.
[0061] As shown in FIG. 2, the center of gravity BG of the battery pack B attached to the battery mounting portion 38 is disposed rearward of the rear end 14r of the rear handle 14. The center of gravity HG of the hedge trimmer 2 is disposed rearward of the rear end 8r of the front handle 8 and forward of the front end 14f of the rear handle 14. The center of gravity HG of the hedge trimmer 2 is disposed inside the motor housing 22. Note that the center of gravity HG indicates the center of gravity of the hedge trimmer 2 in a state in which the battery pack B is attached to the battery mounting portion 38 and in a state in which the rear housing 12 is in a normal position. Although not shown, the center of gravity of the hedge trimmer 2 in a state in which the battery pack B is attached to the battery mounting portion 38 is disposed rearward of the rear end 8r of the front handle 8 and forward of the front end 14f of the rear handle 14 even if the rear housing 12 is in a rotated position.
[0062] (Modification) The working machine may be a working machine (for example, a reciprocating saw, a chain saw, or a brush cutter) other than the hedge trimmer 2. In this case, the working unit 4 may be provided with another working mechanism (for example, a saw blade, a saw chain, or a rotary blade) instead of the pair of shear blades 16.
[0063] The hedge trimmer 2 may be configured so that only one of the pair of shear blades 16 is reciprocated, rather than each of the pair of shear blades 16 being reciprocated.
[0064] The prime mover may be a prime mover other than the electric motor 20 (for example, an engine equipped with an internal combustion engine).
[0065] The rear housing 12 may be provided with a power cord for connection to an external power source (for example, a commercial power source or a backpack power source) instead of the battery mounting portion 38. In this configuration, the hedge trimmer 2 may be operated by power supplied from the external power source via the power cord.
[0066] The electric motor 20 may be a motor other than an inner rotor type brushless motor (for example, an outer rotor type brushless motor, a motor with brushes, etc.).
[0067] The base 6 may be configured to house the motor housing 22 and the mechanism housing 26. This allows the motor housing 22 and the mechanism housing 26 to be hidden when viewed from the outside of the hedge trimmer 2.
[0068] (See FIG. 6) The base 6 may not have the left support portion 80 and the left arm portion 86. In this case, the base 6 may be configured to support the working unit 4 by the right support portion 82 via the vibration-isolating member 90b, and to support the working unit 4 by the rear support portion 84 via the vibration-isolating member 90c. Alternatively, the base 6 may not have the right support portion 82 and the right arm portion 88. In this case, the base 6 may be configured to support the working unit 4 by the left support portion 80 via the vibration-isolating member 90a, and to support the working unit 4 by the rear support portion 84 via the vibration-isolating member 90c.
[0069] (See FIG. 18) The control device 40 does not have to be disposed in the first flow path portion F1. For example, the control device 40 may be disposed in the second flow path portion F2. In this case, the longitudinal direction of the control device 40 may be disposed along the up-down direction. Alternatively, the control device 40 does not have to be disposed in the cooling air flow path F. For example, the control device 40 may be disposed in a position facing the battery mounting portion 38, in front of the battery mounting portion 38.
[0070] (See FIG. 3) The rear housing 12 may be attached to the base 6 so as to be non-rotatable. In this case, the hedge trimmer 2 may not include components such as the rotation lock member 54, the multiple engagement grooves 52, and the receiving groove 58.
[0071] (See FIG. 17) A member for covering the electric motor 20 (for example, a cylindrical cover extending along the outer surface of the stator 28) may be provided between the motor housing 22 and the electric motor 20. This may result in a configuration in which the outer surface of the stator 28 is not exposed to the outside of the hedge trimmer 2 even if the motor housing 22 is removed.
[0072] (See FIG. 2) The shape of the rear part of the rear housing 12 and the arrangement and shape of the battery mounting portion 38 may be changed. As a result, the sliding direction SD of the battery pack B may be a direction different from the direction described in the embodiment. For example, the sliding direction SD may be a direction from below to above, from left to right, or from rear to front.
[0073] (See FIG. 20) When viewed in the axial direction of the rotation axis RA, at least a portion of the rear housing 12 and the battery pack B may be located outside the imaginary circle VC.
[0074] (See FIG. 2) The center of gravity BG of the battery pack B attached to the battery attachment portion 38 may be located forward of the rear end 14r of the rear handle 14.
[0075] (See FIG. 2) The center of gravity HG of the hedge trimmer 2 may be disposed forward of the rear end 8r of the front handle 8. Alternatively, the center of gravity HG of the hedge trimmer 2 may be disposed rearward of the front end 14f of the rear handle 14.
[0076] (See FIG. 6) Due to the symmetry of vibration-proof members 90a, 90b, 90c in the Z direction, the first mounting portion 92 may be attached to the third mounting elements 140, 158, 174, and the third mounting portion 96 may be attached to the first mounting elements 128, 146, 164. In this case, the second mounting portion 94 may be attached to the second mounting element 134 by fitting multiple mounting projections 138 into multiple mounting holes 114.
[0077] As shown in FIG. 21, the vibration-proof members 90a, 90b, 90c may not include the third attachment portion 96 and the second connection portion 100. Even in this case, the working unit 4 can be held on the base 6 by attaching the first attachment portion 92 to the third attachment elements 140, 158, 174 and attaching the second attachment portion 94 to the second attachment elements 134, 152, 168. When the working unit 4 vibrates, the first connection portion 98 undergoes relatively large shear deformation, thereby reducing the vibration transmitted from the second attachment portion 94 to the first attachment portion 92 via the first connection portion 98. This reduces the vibration transmitted from the working unit 4 to the front handle 8 provided on the base 6.
[0078] (See FIG. 7) The shape of the vibration-proof members 90a, 90b, and 90c is not limited to a rectangular parallelepiped shape. The vibration-proof members 90a, 90b, and 90c may have, for example, a substantially cylindrical shape with the height direction being the Z direction.
[0079] (See FIG. 10) The hollow space 120 does not have to be formed inside the first connection part 98. That is, the first connection part 98 may be solid. Moreover, the hollow space 126 does not have to be formed inside the second connection part 100. That is, the second connection part 100 may be solid.
[0080] (See FIG. 7) The second attachment portion 94 does not necessarily have to include the multiple lightening holes 118.
[0081] (See FIG. 7) The shape of the first mounting portion 92 (third mounting portion 96) may be changed. For example, the first mounting portion 92 (third mounting portion 96) may have a protrusion protruding from the mounting surface 106 (mounting surface 122) in the positive Z direction (negative Z direction) instead of the multiple mounting holes 108 (multiple mounting holes 124). The shape of the first mounting elements 128, 146, 164 (third mounting elements 140, 158, 174) may also be changed to match the shape of the first mounting portion 92 (third mounting portion 96). For example, when the first mounting portion 92 (third mounting portion 96) has a protrusion, the first mounting elements 128, 146, 164 (third mounting elements 140, 158, 174) may have a hole or recess that receives the protrusion.
[0082] (See FIG. 7.) The shape of the second mounting portion 94 may be changed. For example, the second mounting portion 94 may not include the multiple mounting holes 114, 116. Also, the second mounting elements 134, 152, 168 may not include the multiple mounting protrusions 138, 156, 172.
[0083] (See FIG. 10) There does not have to be a spatial connection between the multiple mounting holes 108 and the hollow space 120, between the hollow space 120 and the multiple mounting holes 116, between the multiple mounting holes 124 and the hollow space 126, or between the hollow space 126 and the multiple mounting holes 114.
[0084] (Features of the embodiment) As described above, in one or more embodiments, the hedge trimmer 2 (an example of a working machine) includes the electric motor 20, a pair of shear blades 16 (an example of a working mechanism) driven by the electric motor 20, the base 6 supporting the pair of shear blades 16, the rear housing 12 rotatably attached to the rear of the base 6 around a predetermined rotation axis RA and capable of changing its position relative to the base 6 between a normal position and a rotation position rotated from the normal position around the rotation axis RA, the front handle 8 provided on the base 6 and capable of being held by a user with one hand, the rear handle 14 provided on the rear housing 12 and capable of being held by a user with the other hand, and the battery mounting portion 38 provided on the rear housing 12 and to which the battery pack B for supplying power to the electric motor 20 is detachably attached. When the battery pack B is attached to the battery mounting portion 38, the battery pack B is disposed on the rotation axis RA.
[0085] According to the above configuration, the battery pack B is attached to the rear housing 12 so as to be disposed on the rotation axis RA. Therefore, the moment of inertia of the battery pack B about the rotation axis RA becomes relatively small. This allows the user to rotate the rear housing 12 together with the battery pack B with a relatively small force. Therefore, the usability of the hedge trimmer 2 can be improved.
[0086] In one or more embodiments, the battery mounting portion 38 is located at the rear of the rear housing 12 when the rear housing 12 is in a normal position.
[0087] When the user is holding the front handle 8 and the rear handle 14, if the center of gravity HG of the hedge trimmer 2 is close to the user's body, the user can easily handle the hedge trimmer 2. However, the center of gravity HG of the hedge trimmer 2 tends to be closer to the base 6 side (i.e., the front side) that supports the pair of shear blades 16 when viewed from the user's body holding the front handle 8 and the rear handle 14. According to the above configuration, since the battery pack B is attached to the rear part of the rear housing 12, the center of gravity HG of the hedge trimmer 2 can be moved closer to the rear housing 12 side (i.e., the rear side) by the weight of the battery pack B. This allows the center of gravity HG of the hedge trimmer 2 to be closer to the body of the user holding the front handle 8 and the rear handle 14. Therefore, the user can easily handle the hedge trimmer 2.
[0088] In one or more embodiments, when the rear housing 12 is in the normal position and the battery pack B is attached to the battery mounting portion 38, the center of gravity BG of the battery pack B is located rearward of the rear end 14r of the rear handle 14.
[0089] According to the above configuration, no matter what part of the rear handle 14 the user grips, the center of gravity BG of the battery pack B is disposed behind the hand of the user gripping the rear handle 14. In other words, the center of gravity BG of the battery pack B is disposed behind the body of the user. This makes it possible to more reliably bring the center of gravity HG of the hedge trimmer 2 closer to the body of the user.
[0090] In one or more embodiments, when the rear housing 12 is in the normal position, the rear handle 14 is provided on an upper portion of the rear housing 12 and extends along the front-to-rear direction. When the rear housing 12 is in the normal position, the battery pack B is attached to the battery mounting portion 38 by sliding the battery pack B in a sliding direction SD from the upper rear to the lower front relative to the battery mounting portion 38.
[0091] The upper part of the rear housing 12 where the rear handle 14 is provided is the part that the user grips, and therefore needs to have a certain length in the front-rear direction. However, the lower part of the rear housing 12 where the rear handle 14 is not provided may have a shorter length in the front-rear direction. With the above configuration, the battery mounting portion 38 provided at the rear of the rear housing 12 has a shape that is inclined from the rear to the front as it goes from top to bottom. Therefore, the length of the upper part of the rear housing 12 in the front-rear direction can be made relatively short while the length of the lower part of the rear housing 12 can be made relatively long.
[0092] In one or more embodiments, when the rear housing 12 is in the normal position and the battery pack B is attached to the battery mounting portion 38, the center of gravity HG of the hedge trimmer 2 is located rearward of the rear end 8r of the front handle 8 and forward of the front end 14f of the rear handle 14.
[0093] When the center of gravity HG of the hedge trimmer 2 is located between the front handle 8 and the rear handle 14, the center of gravity HG of the hedge trimmer 2 is closer to the body of a user who holds the front handle 8 and the rear handle 14. This makes it easier for the user to handle the hedge trimmer 2.
[0094] In one or more embodiments, when the rear housing 12 and the battery pack B attached to the battery mounting portion 38 are viewed along the axial direction of the rotation axis RA, the rear housing 12 and the battery pack B are located within an imaginary circle VC having a radius of 13 cm and centered on the rotation axis RA.
[0095] According to the above configuration, the moment of inertia around the rotation axis RA of the rear housing 12 and the battery pack B is reduced. This allows the user to rotate the rear housing 12 together with the battery pack B with a small force. This improves the usability of the hedge trimmer 2.
[0096] In one or more embodiments, the base 6 includes a left support portion 80 and / or a right support portion 82 (examples of front support portions) that support the pair of shear blades 16, a rear support portion 84 that supports the pair of shear blades 16 rearward of the left support portion 80 and / or the right support portion 82, and a left arm portion 86 and / or a right arm portion 88 (examples of arm portions) that pass laterally of the pair of shear blades 16 and connect between the left support portion 80 and / or the right support portion 82 and the rear support portion 84.
[0097] According to the above configuration, the size of the base 6 is compact, so that the base 6 is less likely to interfere with the user's body or obstacles when the user uses the hedge trimmer 2. This can improve the usability of the hedge trimmer 2.
[0098] In one or more embodiments, the arm portion includes a left arm portion 86 that passes to the left of the pair of shear blades 16 to connect between the left support portion 80 and the rear support portion 84, and a right arm portion 88 that passes to the right of the pair of shear blades 16 to connect between the right support portion 82 and the rear support portion 84.
[0099] If the left support part 80 and / or the right support part 82 and the rear support part 84 are connected by one arm part, a large stress may act on the arm part while the user is using the hedge trimmer 2. If a large stress acts on the arm part, the arm part may deteriorate. According to the above configuration, the left support part 80 and / or the right support part 82 and the rear support part 84 are connected by the left arm part 86 and the right arm part 88, so that the stress can be dispersed between the left arm part 86 and the right arm part 88. This can prevent a large stress from acting on each of the left arm part 86 and the right arm part 88, so that the deterioration of each of the left arm part 86 and the right arm part 88 can be prevented.
[0100] In one or more embodiments, the working mechanism includes a pair of shear blades 16 (an example of a pair of blades) extending along the front-rear direction. The pair of shear blades 16 are driven by an electric motor 20 to relatively reciprocate in the front-rear direction.
[0101] According to the above configuration, the pair of shear blades 16 may be disposed so as to extend forward as viewed from the front handle 8. In this case, the tendency for the center of gravity HG of the hedge trimmer 2 to be closer to the base 6 (i.e., the front side) becomes significant. According to the above configuration, since the battery pack B is attached to the rear part of the rear housing 12, the center of gravity HG of the hedge trimmer 2 can be moved closer to the rear housing 12 (i.e., the rear side) by the weight of the battery pack B. This allows the center of gravity HG of the hedge trimmer 2 to be closer to the body of the user holding the front handle 8 and the rear handle 14. Therefore, the user can easily handle the hedge trimmer 2. [Explanation of symbols]
[0102] 2: hedge trimmer, 4: working unit, 6: base, 8: front handle, 8r: rear end of front handle, 10: hand guard, 12: rear housing, 14: rear handle, 14f: front end of rear handle, 14r: rear end of rear handle, 16: pair of shear blades, 18: cutting edge, 20: electric motor, 22: motor housing, 24: power transmission mechanism, 26: mechanism housing, 28: stator, 30: rotor, 32: output shaft, 34: bearing, 36: bearing, 38: battery mounting portion, 40: control device, 42: control board, 44: controller case base, 46: shaft portion, 48: shaft holding portion, 50: cylindrical surface, 52: engagement groove, 54: rotation lock member, 56: lock piece, 58: accommodation groove, 60: operation portion, 62: coil spring, 63: support protrusion, 64: operation button, 66: trigger lever, 68: lock-off lever, 70: microswitch, 72: base body, 74: handle member, 76: semi-cylindrical member, 78: plate member, 80: left side support portion, 82: right side support portion, 84: rear side support portion, 86: left side arm portion, 88: right side arm portion, 90a: vibration-proof member, 90b: vibration-proof member, 90c: vibration-proof member, 92: first mounting portion, 94: second mounting portion, 96: third mounting portion, 98: first connection portion, 100: second connection portion, 102: first groove, 104: second groove, 106: mounting surface, 108: mounting hole, 110: end face, 112: mounting recess, 114: mounting hole, 116: mounting hole, 118: lightening hole, 120: hollow space, 122: mounting surface, 124: mounting hole, 126: hollow space, 128: first mounting element, 130: support surface, 132: mounting protrusion, 134: second mounting element, 136: mounting frame, 138: mounting protrusion, 140: third mounting element, 142: support surface, 144: mounting protrusion, 146: first mounting element, 148 : Support surface, 150: mounting projection, 152: second mounting element, 154: mounting frame, 156: mounting projection, 158: third mounting element, 160: support surface, 162: mounting projection, 164: first mounting element, 166: support surface, 168: second mounting element, 170: mounting frame, 172: mounting projection, 174: third mounting element, 176: support surface, 178: mounting projection, 180: left housing member, 182: right housing member, 184: motor support frame, 186: duct portion, 188: air intake port, 190L: exhaust port, 190R: exhaust port, 192: passage portion, 194: through hole, 196: exhaust port,198L: air intake port, 198R: air intake port, 200: opening, 202: gap, 204: fan, 540: slider, 542: pin, 544: long hole, 546: notch groove, 548: protrusion, A1: first vibration-proof area, A2: second vibration-proof area, B: battery pack, BG: center of gravity, F: cooling air flow path, F1: first flow path part, F2: second flow path part, F3: third flow path part, F4: fourth flow path part, F5: fifth flow path part, F6: sixth flow path part,
Claims
1. Electric motor and, The work mechanism driven by the aforementioned electric motor, A base supporting the aforementioned working mechanism, A rear housing is mounted to the rear of the base so as to be rotatable about a predetermined axis of rotation, and its position relative to the base can be changed between a normal position and a rotated position obtained by rotating from the normal position about the axis of rotation, The base is provided with a front handle that can be grasped by the user with one hand, A rear handle is provided on the rear housing and can be grasped by the user with the other hand, The rear housing is provided with a battery mounting section to which a battery pack for supplying power to the electric motor is detachably attached, A work machine in which, when the battery pack is attached to the battery mounting portion, the battery pack is positioned on the rotating shaft.
2. The work machine according to claim 1, wherein when the rear housing is in the normal position, the battery mounting portion is provided at the rear of the rear housing.
3. The work machine according to claim 2, wherein, when the rear housing is in the normal position and the battery pack is attached to the battery mounting portion, the center of gravity of the battery pack is positioned behind the rear end of the rear handle.
4. When the rear housing is in the normal position, The aforementioned rear handle is provided on the upper part of the rear housing and extends along the front-to-back direction. The work machine according to claim 1, wherein the battery pack is attached to the battery mounting portion by sliding it in a sliding direction from rear-upward to front-downward relative to the battery mounting portion.
5. The work implement according to claim 1, wherein, when the rear housing is in the normal position and the battery pack is attached to the battery mounting portion, the center of gravity of the work implement is positioned behind the rear end of the front handle and in front of the front end of the rear handle.
6. The work machine according to claim 1, wherein when the rear housing and the battery pack attached to the battery mounting portion are viewed along the axial direction of the rotation axis, the rear housing and the battery pack are located inside a virtual circle with a radius of 13 cm centered on the rotation axis.
7. The aforementioned base is A front support portion that supports the aforementioned working mechanism, A rear support portion supporting the work mechanism is located behind the front support portion, The work machine according to claim 1, further comprising an arm portion that passes to the side of the work mechanism and connects the front support portion and the rear support portion.
8. The aforementioned arm portion is A left arm portion that passes to the left of the aforementioned working mechanism and connects the front support portion and the rear support portion, The work machine according to claim 7, further comprising a right-side arm portion that passes to the right of the work mechanism and connects the front support portion and the rear support portion.
9. The aforementioned working mechanism is equipped with a pair of blades extending along the front-rear direction, The work machine according to claim 1, wherein the pair of blades are driven by the electric motor to reciprocate relative to each other in the front-rear direction.