Work machine

Abstract

To provide a work machine in which a high degree of freedom is realized in arrangement of positions of a circuit board and the likes.SOLUTION: A working machine according to the invention includes: a motor (11); a circuit board (12) for controlling the motor; a housing (13) for housing the motor and the circuit board; and a battery pack (14) electrically connectable to the motor; and a third flow path (15) including a first flow path (151) in which air flows in a first direction and a second flow path (152) in which air flows in a second direction different from the first direction.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present disclosure relates to a work machine. [Background technology]

[0002] Patent Document 1 discloses a brush cutter equipped with a rotary blade. The brush cutter includes a rod-shaped support rod having a front end and a rear end, a cutter unit including a rotary blade for cutting grass and disposed at the front end of the support rod, a rear end unit disposed at the rear end of the support rod, and a handle disposed on the support rod for an operator to hold during use. The housing of the rear end unit is provided with an intake hole for taking in outside air. Air sucked in through the intake hole flows through the tube of the support rod to the cutter unit disposed at the front end, cooling the motor and reduction gear. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2014-117264 A Summary of the Invention [Problem to be solved by the invention]

[0004] One aspect of the present disclosure realizes a work machine with a high degree of freedom in terms of the arrangement position of a circuit board, etc. [Means for solving the problem]

[0005] A work machine according to one embodiment of the present disclosure includes a motor, a circuit board that controls the motor, a housing that accommodates the motor and the circuit board, a battery pack that can be electrically connected to the motor, and a third flow path that includes a first flow path through which air flows in a first direction and a second flow path through which the air flows in a second direction that is different from the first direction, and the circuit board and the motor are cooled by air flowing through the third flow path. Effect of the Invention

[0006] According to one aspect of the present disclosure, a work machine having a high degree of freedom in terms of the placement position of a circuit board, etc. can be realized. [Brief description of the drawings]

[0007] [Figure 1] 1 is a perspective view showing an entire working machine according to a first embodiment. [Diagram 2] 1 is a perspective view showing a configuration of a motor unit provided in a work machine according to a first embodiment. [Diagram 3] 3 is a perspective view showing the configuration of a motor unit provided in the work machine according to the first embodiment, seen from a different direction than FIG. 2. [Figure 4] FIG. 2 shows the battery pack removed from the housing. [Diagram 5] FIG. 2 shows the housing with the battery pack removed. [Figure 6] 3 is a perspective view showing an air flow in the work machine according to the first embodiment. FIG. [Figure 7] 4 is a cross-sectional view of the housing taken along a plane including the surface of the circuit board. FIG. [Figure 8] FIG. 11 is a perspective view showing the configuration of a motor unit according to a second embodiment. [Figure 9] FIG. 11 is a perspective view showing the entirety of a work machine according to a third embodiment. [Figure 10] FIG. 11 is a perspective view showing the configuration of an operating unit provided in a work machine according to a third embodiment. [Figure 11] FIG. 2 is a diagram illustrating an example of a control board. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] [Embodiment 1] Hereinafter, one embodiment of the present disclosure will be described in detail.

[0009] (Overall configuration of the work machine) Fig. 1 is a perspective view showing an entire working machine 1 according to embodiment 1. In the example shown in Fig. 1, the working machine 1 is a brush cutter. As shown in Fig. 1, the working machine 1 includes a motor unit 10, an operating shaft 20, a cutting blade 30, and a handle 40.

[0010] The cutting blade 30 is a disk-shaped blade. The cutting blade 30 is an example of a rotating mechanism used in work by the work machine 1, and performs a rotational motion to mow down an object. The motor unit 10 rotates the cutting blade 30. A specific configuration of the motor unit 10 will be described later.

[0011] The operating shaft 20 connects the motor unit 10 and the cutting blade 30. The operating shaft 20 is a rotating shaft housing that accommodates a drive shaft 21, which will be described later, therein.

[0012] The handle 40 is a part that is gripped by a user who performs work using the work machine 1. The handle 40 is attached to the center of the operating main shaft 20, closer to the motor unit 10. The handle 40 has a U-shape that opens above the operating main shaft 20 when the work machine 1 is in use. An operating unit 45 that accepts operations by the user is attached to the handle 40.

[0013] (Motor unit) Fig. 2 is a perspective view showing the configuration of the motor unit 10 provided in the work machine 1. Fig. 3 is a perspective view from a different direction than Fig. 2 showing the configuration of the motor unit 10 provided in the work machine 1. As shown in Figs. 2 and 3, the motor unit 10 includes a motor 11, a circuit board 12, a housing 13, and a battery pack 14. For simplicity, the battery pack 14 is omitted in Fig. 3.

[0014] The motor 11 is a motor connected to a drive shaft 21 in the operating shaft 20. The motor 11 has a structure that allows air to flow through the inside. The drive shaft 21 transmits the rotation of the motor 11 to the cutting blade 30. The circuit board 12 controls the motor 11. The circuit board 12 may be equipped with, for example, a control circuit that controls the power supplied to the motor 11 from a battery pack 14. The housing 13 accommodates the motor 11 and the circuit board 12.

[0015] The battery pack 14 supplies power to the motor 11. The battery pack 14 can be electrically connected to the motor 11. Specifically, the housing 13 includes an attachment mechanism (not shown) for attaching the battery pack 14, and wiring (not shown) for electrically connecting the battery pack 14 and the motor 11 when the battery pack 14 is attached to the attachment mechanism. The attachment mechanism may be one that attaches the battery pack 14 to the housing 13 by sliding the battery pack 14 along an attachment direction described below, but is not limited to this.

[0016] (intake and exhaust) Fig. 4 is a diagram showing the battery pack 14 in a state removed from the housing 13. In Fig. 4, reference numerals 401 and 402 indicate perspective views of the battery pack 14 viewed from two different directions. As shown in Figs. 2 and 4, the battery pack 14 has a first intake port 14a and a first exhaust port 14b. The first intake port 14a is an opening that takes in air from the outside of the battery pack 14. The first exhaust port 14b is an opening that exhausts the air taken in from the first intake port 14a to the outside of the battery pack 14.

[0017] Fig. 5 is a perspective view showing the housing 13 with the battery pack 14 removed. Specifically, Fig. 5 is a perspective view of the housing 13 with the battery pack 14 removed, viewed from the opposite side to the operating shaft 20 and from a direction in which the position where the battery pack 14 is attached to the housing 13 is below the operating shaft 20.

[0018] As shown in Figs. 2, 3 and 5, the housing 13 has a second intake port 13a and a second exhaust port 13b. The second intake port 13a is an opening that takes in air from the outside of the housing 13. The second intake port 13a is located near the position where the battery pack 14 is attached. The second exhaust port 13b is an opening that exhausts the air taken in from the second intake port 13a to the outside of the housing 13. The second exhaust port 13b is provided only on one side surface of the housing 13. When using the work machine 1, the user is positioned on the side of the housing 13 opposite to the side where the second exhaust port 13b is provided.

[0019] In the work machine 1, the housing 13 has two second intake ports 13a, one above and one below. Both the air exhausted from the first exhaust port 14b and the air from outside the work machine 1 are taken into the housing 13 through both the upper and lower second intake ports 13a.

[0020] However, the upper second air intake port 13a faces the first exhaust port 14b when the battery pack 14 is attached to the housing 13. Therefore, the upper second air intake port 13a takes in a large proportion of the air exhausted from the first exhaust port 14b into the housing 13. The lower second air intake port 13a is shifted from a position facing the first exhaust port 14b. Therefore, the lower second air intake port 13a takes in a large proportion of the air from outside the work machine 1 into the housing 13 through the gap between the housing 13 and the battery pack 14.

[0021] (Third flow path) 6 is a perspective view showing the air flow in the work machine 1. In the work machine 1, the motor 11 drives not only the cutting blade 30 but also a fan (not shown) provided in the housing 13. The fan exhausts the air inside the housing 13 to the outside through the second exhaust port 13b. Therefore, in the work machine 1, an air flow is generated that flows from the first intake port 14a through the first exhaust port 14b and the second intake port 13a toward the second exhaust port 13b.

[0022] The flow path through which air flows from the first intake port 14a to the second exhaust port 13b is referred to as a third flow path 15. The third flow path 15 may be formed by the housing 13 itself. Specifically, the section from the upper side of the circuit board 12 to the rear of the motor 11 may be formed by a rib 13d (see FIG. 2) formed inside the housing 13. The other sections within the housing 13 may be formed by the outer wall of the housing 13. The motor 11 and the circuit board 12 are cooled by the air flowing through the third flow path 15.

[0023] The air flows in the third flow path 15 as follows. The air that flows into the battery pack 14 from the first intake port 14a flows through the battery pack 14 to the first exhaust port 14b. The air that comes out from the first exhaust port 14b flows into the housing 13 from the second intake port 13a, hits the circuit board 12 and cools it. The air that hits the circuit board 12 flows around to the opposite side of the circuit board 12, then flows upward and turns back, and flows through the space defined by the rib 13d to the rear of the motor 11. The rear here means the opposite side of the motor 11 from the operating shaft 20. The air then flows upward again and turns back, flows through the motor 11, and is discharged to the outside of the working machine 1 from the second exhaust port 13b.

[0024] Fig. 7 is a cross-sectional view of housing 13 in a plane including the surface of circuit board 12. As shown in Fig. 7, third flow path 15 may be provided so as to flow between the peripheral edge of circuit board 12 and housing 13. As a result, air that hits the surface of circuit board 12 passes between the peripheral edge of circuit board 12 and housing 13, turns around to the opposite side to second intake port 13a, and flows further downstream.

[0025] The third flow path 15 includes a first flow path 151 and a second flow path 152. The first flow path 151 is a section of the third flow path 15 in which air flows in a first direction indicated by an arrow 601. The second flow path 152 is a section of the third flow path 15 in which air flows in a second direction indicated by an arrow 602. The second direction is a direction different from the first direction. In FIG. 6, the first direction and the second direction are opposite to each other. However, in the work machine 1, the first direction and the second direction only need to be different from each other, and do not necessarily have to be opposite to each other.

[0026] Specifically, the first flow path 151 is a section in which the air flows from the first intake port 14a to the first exhaust port 14b, and further flows from the second intake port 13a to the opposite side of the circuit board 12. The second flow path 152 is a section in which the air flows upward on the opposite side of the circuit board 12, turns back, and then flows through a space defined by the rib 13d to the rear of the motor 11.

[0027] In the work machine 1, at least a portion of the first flow path 151 may be located inside the battery pack 14. Therefore, the battery pack 14 can also be cooled by the air flowing through the first flow path 151. However, a portion of the first flow path 151 does not necessarily have to be located inside the battery pack 14, and both the first flow path 151 and the second flow path 152 may be located only inside the housing 13.

[0028] In the work machine 1, air may also flow in the first direction inside the motor 11. That is, at least a portion of the first flow path 151 may be located inside the motor 11. As described above, the motor 11 has a configuration that allows air to flow therethrough. In this case, the motor 11 is cooled by the air flowing through the third flow path 15.

[0029] In this way, since the third flow path 15 has the first flow path 151 and the second flow path 152, the length of the third flow path 15 is longer than when air flows in only one direction inside the work machine 1. Therefore, in the work machine 1, when elements to be cooled, such as the circuit board 12, are arranged on the third flow path 15, the degree of freedom in the arrangement position is higher than in conventional work machines.

[0030] 5, the first flow path 151 is located in the battery pack 14 and in the motor 11. In other words, the air flows in the same direction in the battery pack 14 and in the motor 11. However, in the work machine 1, the air does not have to flow in the same direction in the battery pack 14 and in the motor 11. For example, the air flows in the motor 11 in a direction different from both the first direction and the second direction.

[0031] 4 indicate the mounting direction in which the battery pack 14 is mounted to the housing 13. The mounting direction may be parallel to the first direction. Therefore, even if a small deviation occurs in the position of the battery pack 14 in the mounting direction, the possibility that the third flow path 15 is interrupted between the battery pack 14 and the housing 13 can be reduced. Therefore, the accuracy required for mounting the battery pack 14 is reduced. However, the mounting direction does not necessarily have to be parallel to the first direction, and may be, for example, perpendicular to the first direction.

[0032] Also, as shown in FIG. 5, the position of the circuit board 12 in the first direction may be offset from the position of the motor 11 in the first direction. For example, the position of the circuit board 12 in the first direction may be downstream of the position of the motor 11 in the first direction in the flow of air in the first direction. This prevents the circuit board 12 and the motor 11 from being arranged side by side in a direction perpendicular to the first direction. Therefore, even if the surface of the circuit board 12 on which the heat-generating components are arranged is arranged perpendicular to the first direction, the increase in size of the housing 13 can be reduced. However, in the working machine according to the present disclosure, the position of the circuit board 12 in the first direction does not necessarily have to be offset from the position of the motor 11 in the first direction.

[0033] (4th flow path) 4, the housing 13 may have a third intake port 13c separate from the second intake port 13a. The third intake port 13c may be located on the left and right side surfaces of the housing 13 when the direction in which the operating shaft 20 extends from the motor unit 10 is defined as the forward direction. In this case, air is also taken into the work machine 1 through the third intake port 13c.

[0034] The flow path through which the air taken into the working machine 1 from the third intake port 13c flows is referred to as the fourth flow path 16. The fourth flow path 16 may be formed by the outer wall of the housing 13. The fourth flow path 16 is a flow path that merges with the third flow path 15. Specifically, the third flow path 15 includes a junction 153 where the fourth flow path 16 merges. The air taken into the working machine 1 from the third intake port 13c flows through the fourth flow path 16 to the junction 153 as shown by an arrow 603 in FIG. 6. After reaching the junction 153, the air taken into the working machine 1 from the third intake port 13c flows through the third flow path 15 to the second exhaust port 13b in the same direction as the arrow 601, and is finally exhausted to the outside of the working machine 1 from the second exhaust port 13b.

[0035] The junction 153 may be located upstream of the motor 11 in the air flow. Therefore, the air taken into the work machine 1 from the third air intake port 13c also flows through the fourth flow path 16 to the junction 153, and then flows through the first flow path 151 located inside the motor 11 as shown in FIG. 6. This increases the amount of air cooling the motor 11, improving the cooling performance of the motor 11. However, the work machine 1 does not necessarily have to be provided with the fourth flow path 16.

[0036] As described above, the work machine 1 is provided with a fan driven by the motor 11. The fan generates air flows in the third flow path 15 and the fourth flow path 16. However, the work machine 1 may generate the above-mentioned air flows by a mechanism other than the fan driven by the motor 11. For example, the work machine 1 may be provided with a fan driven by a motor other than the motor 11.

[0037] The working machine 1 according to the present disclosure is not limited to a brush cutter, as long as it has a rotation mechanism driven by a motor. Other examples of the working machine 1 include a chain saw, a blower, and a circular saw.

[0038] [Embodiment 2] Other embodiments of the present disclosure will be described below. For convenience of explanation, the same reference numerals will be given to components having the same functions as those described in the above embodiment, and the description thereof will not be repeated.

[0039] 8 is a perspective view showing the configuration of a motor unit 10A according to embodiment 2. Motor unit 10 differs from motor unit 10 in the position of circuit board 12. Specifically, in motor unit 10A, circuit board 12 is located at junction 153 where third flow path 15 and fourth flow path 16 join.

[0040] Therefore, in the motor unit 10A, not only the motor 11 but also the circuit board 12 is cooled by air from both the third flow path 15 and the fourth flow path 16. Therefore, in a work machine including the motor unit 10A, the cooling performance of the circuit board 12 is improved compared to the work machine 1.

[0041] [Embodiment 3] Further embodiments of the present disclosure are described below.

[0042] Fig. 9 is a perspective view showing the entirety of a work machine 3 according to embodiment 3. As shown in Fig. 9, the work machine 3 differs from the work machine 1 in that it includes a handle 50 instead of the handle 40 and an operation unit 60 instead of the operation unit 45.

[0043] The handle 50 differs from the handle 40 in that it has an annular shape. The term "annular" used here means a shape whose start point and end point are connected to the operating shaft 20, and does not necessarily mean a circular ring shape.

[0044] 10 is a perspective view showing the configuration of an operating unit 60 provided in the work machine 3. The operating unit 60 is a mechanism for receiving operations by a user. It is difficult to provide the operating unit 60 on the handle 50 having the above-mentioned annular shape. For this reason, in the work machine 3, the operating unit 60 is provided on the operating main shaft 20. As shown in FIG. 10, the operating unit 60 includes a trigger 61, a control board 62, and a gear shift lever 63.

[0045] The trigger 61 accepts operations by the user to start and stop the work machine 3. The control board 62 is attached to the operating shaft 20, and is a volume board that varies the ratio of the rotational speed of the cutting blade 30 to the rotational speed of the motor 11 (see FIG. 2). The speed change lever 63 is attached to the control board 62, and accepts operations by the user to determine the ratio of the rotational speed of the cutting blade 30 to the rotational speed of the motor 11. The control board 62 detects the amount of operation of the speed change lever 63 by the user, and outputs a signal corresponding to the amount of operation to the circuit board 12.

[0046] Fig. 11 is a diagram showing an example of the control board 62. In Fig. 11, reference numeral 1101 is a perspective view showing the control board 62 with the shift lever 63 attached. Reference numerals 1102 and 1103 are perspective views showing the control board 62 with the shift lever 63 removed. Reference numeral 1102 also shows the shift lever 63 removed from the control board 62. Reference numeral 1104 is a front view showing the control board 62 with the shift lever 63 removed.

[0047] 11, the control board 62 has a rotating shaft 62a and a sensor 62b. The gearshift lever 63 is attached to the rotating shaft 62a. The rotating shaft 62a rotates in response to the amount of operation of the gearshift lever 63 by the user. The sensor 62b outputs a signal corresponding to the amount of rotation of the rotating shaft 62a, i.e., the amount of operation of the gearshift lever 63 by the user.

[0048] The sensor 62b continuously detects the amount of operation of the gear shift lever 63 by the user. However, the sensor 62b does not necessarily have to continuously detect the amount of operation of the gear shift lever 63 by the user, and may detect, for example, which of a plurality of preset steps the amount of operation is.

[0049] When the work machine 3 is in use, the control board 62 is located above the main operating shaft 20. Therefore, the distance between the handle 50 and the end of the gear shift lever 63 connected to the control board 62 is closer than when the control board 62 is located below the main operating shaft 20 when the work machine 3 is in use. Therefore, the gear shift lever 63 can be made smaller.

[0050] 〔summary〕 A work machine according to a first aspect of the present disclosure comprises a motor, a circuit board that controls the motor, a housing that accommodates the motor and the circuit board, a battery pack electrically connectable to the motor, and a third flow path including a first flow path through which air flows in a first direction and a second flow path through which the air flows in a second direction that is different from the first direction, and the circuit board and the motor are cooled by air flowing through the third flow path.

[0051] A work machine according to a second aspect of the present disclosure is the work machine of the first aspect, wherein at least a portion of the first flow path is located inside the battery pack.

[0052] A work machine according to a third aspect of the present disclosure is in accordance with the second aspect, wherein the direction in which the battery pack is attached to the housing is parallel to the first direction.

[0053] A work machine according to a fourth aspect of the present disclosure is any one of the first to third aspects, in which the position of the circuit board in the first direction is offset from the position of the motor in the first direction.

[0054] A working machine according to aspect 5 of the present disclosure is any one of aspects 1 to 4, further comprising a fourth flow path that merges with the third flow path, the third flow path having a junction where the fourth flow path merges, the junction being located upstream of the motor in the air flow.

[0055] A sixth aspect of the present disclosure relates to a work machine according to the fifth aspect, wherein the circuit board is located at the junction.

[0056] The working machine according to aspect 7 of the present disclosure, in any of aspects 1 to 6, further comprises a rotating shaft that transmits rotation of the motor, a rotating shaft housing that accommodates the rotating shaft, a rotating mechanism that rotates by the rotation of the motor transmitted by the rotating shaft, a control board attached to the rotating shaft housing and changing the ratio of the rotational speed of the rotating mechanism to the rotational speed of the motor, a shift lever attached to the control board and accepting operations to determine the ratio, and a ring-shaped handle that is located above the rotating shaft housing when the working machine is in use and is held by a user using the working machine, and the control board is located above the rotating shaft housing when the working machine is in use.

[0057] The present disclosure is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present disclosure. [Explanation of symbols]

[0058] 1, 3 Work equipment 11 Motor 12 Circuit Board 13. Housing 14 Battery Pack 15 Third Stream 151 First Channel 152 Second Channel 153 Confluence 16 4th Stream

Claims

1. A motor; A circuit board for controlling the motor; a housing that accommodates the motor and the circuit board; a battery pack electrically connectable to the motor; a third flow path including a first flow path in which air flows in a first direction and a second flow path in which the air flows in a second direction different from the first direction; The circuit board and the motor are cooled by air flowing through the third flow path.

2. The work machine according to claim 1 , wherein at least a portion of the first flow path is located within the battery pack.

3. The work machine according to claim 2 , wherein a direction in which the battery pack is attached to the housing is parallel to the first direction.

4. The work machine according to claim 1 , wherein a position of the circuit board in the first direction is offset from a position of the motor in the first direction.

5. Further comprising a fourth flow path joining the third flow path, the third flow path has a junction where the fourth flow path joins, The work machine according to claim 1 , wherein the junction is located upstream of the motor in the air flow.

6. The work machine according to claim 5 , wherein the circuit board is located at the junction.

7. a rotating shaft that transmits rotation of the motor; a rotating shaft housing that accommodates the rotating shaft; a rotation mechanism that rotates by the rotation of the motor transmitted by the rotation shaft; a control board attached to the rotating shaft housing and configured to vary a ratio of a rotation speed of the rotating mechanism to a rotation speed of the motor; a gear shift lever attached to the control board and adapted to receive an operation for determining the ratio; a ring-shaped handle that is located above the rotary shaft housing and is gripped by a user who uses the working machine when the working machine is in use, The work machine according to claim 1 , wherein the control board is located above the rotating shaft housing when the work machine is in use.

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