Working machine

Abstract

To provide a working machine which can surely protect a noise reduction component from an external impact and vibration, does not increase the number of components, and is easy to assemble and remove.SOLUTION: According to an aspect of the present invention, there is provided a working machine including a working unit and a main body connected to the working unit, wherein the main body includes a housing, and a control board, a cover member, and a noise reduction component that are disposed in the housing, the control board is configured to control an operation of the working unit, the cover member is disposed to cover the control board, and the noise reduction component is attached to the cover member.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] Ferrite cores have conventionally been used to reduce noise generated in power tools (see Patent Documents 1 and 2). The power tools disclosed in Patent Documents 1 and 2 are lightweight and compact, with a low-weight battery located below the handle, and the operator grips the handle while working. These power tools, including the battery, are small and light enough to be held in one hand. If the power tool were to fall, the battery, which is a heavy component, would fall first. However, the ferrite core is located on the opposite side of the battery in the vertical direction, at the end closest to the operator, and is therefore protected from external impacts. Furthermore, because the housing itself is small, it can be stably fixed by being sandwiched between the split surfaces of the left and right housings. In Patent Document 1, to make the power tool less susceptible to external impacts, a ferrite core is placed on the split surface of the housing and fixed with a retaining rib. This configuration protects the ferrite core from damage when dropped and vibration during use.

[0003] However, if this structure is applied as is to a portable brush cutter, chain saw, or other work machine that is larger and has higher output than handheld power tools, it will not be possible to mitigate the effects of shock and vibration on the ferrite core. To explain this in more detail using the brush cutter shown in Figure 7 as an example, a large battery is located at the rear end of the brush cutter, and a working unit with a rotary blade is located at the front end. This brush cutter weighs 3 to 4 kg or more overall. The operator grasps the handle located in the middle of the brush cutter's length and moves the entire brush cutter left and right to perform brush cutting. In such a portable brush cutter, if the operator lets go of the handle and the brush cutter falls, an impact will be applied to the housing surrounding the heavy battery. In such a brush cutter, if the ferrite core is fixed to the inner wall of the housing, there is a risk of it becoming dislocated or being damaged by an external impact. Furthermore, since the width of the housing (the distance between the inner walls of the housing) is larger than that of a handheld power tool, the dividing surface alone cannot accommodate the longitudinal length of the ferrite core as in Patent Document 1, and a separate fixing part is required.

[0004] In addition, in Patent Document 2, the ferrite core is fixed to the electric circuit board to which the electric wire is electrically connected while the electric wire is running through it. This allows the ferrite core to be stably fixed even when subjected to external shocks or vibrations, but on the other hand, it is difficult to assemble and remove. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-143499 [Patent Document 2] Japanese Patent Application Laid-Open No. 2016-193475 Summary of the Invention [Problem to be solved by the invention]

[0006] In view of the above circumstances, the present invention aims to provide a work machine that can reliably protect noise reduction parts from external shocks and vibrations, does not increase the number of parts, and is easy to assemble and disassemble. [Means for solving the problem]

[0007] According to one aspect of the present invention, there is provided a work machine comprising a working unit and a main body connected to the working unit, the main body having a housing and a control board, a cover member and a noise reduction component arranged within the housing, the control board being configured to control the operation of the working unit, the cover member being arranged to cover the control board, and the noise reduction component being attached to the cover member.

[0008] According to this aspect, the noise reduction components can be disposed at a position separate from the housing, without increasing the number of components, while using components separate from the housing, thereby protecting the noise reduction components from external impacts. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a perspective view of a brush cutter as an example of a working machine. [Figure 2] FIG. 2 is a vertical cross-sectional view of the main body portion as viewed obliquely from the upper left side. [Figure 3] FIG. 2 is a view of the internal structure of the main body as seen from the right rear side. [Figure 4] FIG. 2 is a view of a vertical cross section of the main body portion as seen from the right rear side. [Figure 5] FIG. 4 is a diagram in which the air guide is omitted from the state of FIG. 3. [Figure 6] 1A and 1B are perspective views of the support body ((a) is a view from the right rear side, and (b) is a view from the right front side). [Figure 7] FIG. 1 is a perspective view of a typical brush cutter. DETAILED DESCRIPTION OF THE INVENTION

[0010] The present embodiment will be described below with reference to the drawings. Various features shown in the following embodiment can be combined with each other. Fig. 1 is a perspective view of a brush cutter, which is an example of a work machine. Fig. 2 is a vertical cross-sectional view of the main body, seen from the diagonally upper left side. Fig. 3 is a view of the internal structure of the main body, seen from the right rear side. Fig. 4 is a vertical cross-sectional view of the main body, seen from the right rear side. Fig. 5 is a view of Fig. 3, with the air guide omitted. Fig. 6 is a perspective view of the support ((a) view from the right rear side, (b) view from the right front side). The directions of the components of the brush cutter are defined based on the "up and down," "left and right," and "front and back" shown in the drawings.

[0011] The brush cutter 1 shown in Figure 1 is a portable work machine that is larger than a power tool. The brush cutter 1 includes a working unit 2 and a main body 3 connected to the rear (base end) of the working unit 2 via a connecting unit 4. In this embodiment, a brush cutter 1 is used as an example, but other portable work machines used outdoors, such as a chainsaw or power blower, may also be used. In the brush cutter 1, the connecting unit 4 is provided between the main body 3 and the working unit 2, and the main body 3 and the working unit 2 are spaced apart. However, a direct connection between the main body and the working unit, such as in a chainsaw, is also within the technical scope of the present application. The main body 3 may be separated from the connection part 4, and the battery part, which is a heavy object, may be carried on the worker's back.

[0012] The working unit 2 has a rotary blade 21, a rotary shaft 22 that is the center of rotation of the rotary blade 21, and a fan-shaped cover 23 that is provided to cover the rotary blade 21. The cover 23 can prevent pieces of cut grass, trees, and other objects from flying directly towards the worker. The main body 3 has a casing (housing) 31 and an electric motor (prime mover) 32 housed in the casing 31. The casing 31 can be made of, for example, a metal material, a resin material, or the like. In this embodiment, a battery B for supplying electricity to the electric motor 32 is attached to the rear end of the main body 3.

[0013] The connecting part 4 has a grip 41 whose rear end is connected to the casing 31 of the main body 3, and an operating rod 42 inserted into the inside of the grip 41. The grip 41 and the operating rod 42 are each made of a tubular metal member or a tubular resin member, and a drive transmission shaft 43 is inserted into the inside of the operating rod 42. The front end of the drive transmission shaft 43 is connected to the rotary shaft 22 of the rotary blade 21. The rear end of the drive transmission shaft 43 is connected to the output shaft 322 of the electric motor 32 (see FIG. 2). The rotary blade 21 is configured to rotate when the rotational drive force of the output shaft 322 of the electric motor 32 is transmitted to the rotary shaft 22 via the drive transmission shaft 43. The cover 23 is fixed to the front end of the operating rod 42.

[0014] The operating rod 42 is provided with a safety bar 51, a handle 52, and an operating part 53 in this order from the front to the rear. The safety bar 51 is provided so as to protrude to the left (side) from the operating rod 42. In the unlikely event that the working unit 2 moves toward the operator, the safety bar 51 will come into contact with the operator and stop the working unit 2, preventing the rotary blade 21 from approaching the operator. In this way, the safety of the operator is ensured by the presence of the safety bar 51. The handle 52 is made of a curved pipe-shaped member that forms a ring, and is fixed to the operating rod 42.

[0015] The operation unit 53 is provided with operation buttons for turning on / off and changing the speed of the electric motor (drive mechanism) 32. By holding the grip 41, the operation unit 53 can be easily and safely operated. With this brush cutter 1, an operator holds the grip 41 with one hand and the handle 52 with the other hand, and moves the working unit 2 left and right to cut vegetation.

[0016] As shown in FIG. 2, the electric motor 32 has a stator 321 fixed to the casing 31, and an output shaft 322 rotatably supported by the stator 321 via bearings 323 and 324. The rear end of the drive transmission shaft 43 is connected to and fixed to the front end of the output shaft 322. The fan 33 is also fixed to the rear end of the output shaft 322. With this configuration, when the output shaft 322 rotates, the drive transmission shaft 43 and the fan 33 rotate accordingly. The airflow generated by the rotation of the fan 33 is configured to flow from the rear end side of the main body 3 to the front end side.

[0017] A control board 6 is disposed on the rear end side of the fan 33 inside the casing 31, and controls the operation of the working unit 2 via an electric motor 32, for example. 3, an air guide (cover member) 7 and a noise reduction component 8 are disposed within the casing 31. The air guide 7 is box-shaped and disposed so as to cover the control board 6. The noise reduction component 8 is attached to the air guide 7. That is, the fan 33, electric motor 32, control board 6, and air guide 7 are arranged side by side in the center of the casing 31, and the casing 31 houses them. With this arrangement, external impacts are less likely to be applied not only to the noise reduction component 8 but also to the air guide 7, to which the noise reduction component 8 is attached. Therefore, in addition to impacts on the noise reduction component 8 itself, damage to the attachment target and attachment structure is also protected, and the noise reduction component 8 is more stably fixed. Furthermore, with the above arrangement, the wiring cables 9 extending from the control board 6 and connected to the electric motor 32 and the battery B can also be concentrated in the center of the casing 31. This allows the wiring cables 9 to be shortened, making them easier to handle.

[0018] When the fan 33 rotates, as shown by the thick arrow in FIG. 4, air is drawn into the casing 31 from below the battery B, passes forward through the lower side of the casing 31, rises inside the air guide 7, and then passes forward through the upper side of the casing. That is, the air guide (cover member) 7 has the function of defining the flow path of air that comes into contact with the control board 6. The air passing through the air guide 7 effectively cools the control board 6 provided therein, preventing the temperature of the control board 6 from rising. Note that the cover member may be configured to simply cover the control board 6 without having the function of defining the flow path of air (function as an air guide). The cover member may also have other functions in addition to its function as an air guide. As shown in Fig. 5, the control board 6 has a board body 61 on which electronic components are mounted, and fins 62 joined to the board body 61. The fins 62 include a plurality of flat plates, each of which is arranged along the air flow direction (vertical direction). Air flows through the gaps between the flat plates, thereby efficiently cooling the electronic components on the board body 61. The fins 62 can be made of, for example, a metal material, a ceramic material, or the like.

[0019] A noise reduction component 8 is attached to the air guide 7. By providing a support portion (mounting portion) 72 for the noise reduction component 8 on the air guide 7 that covers the control board 6, the noise reduction component 8 can be placed close to the control board 6, which is a likely source of noise. This is expected to improve the noise reduction effect. Furthermore, because the noise reduction component 8 is not fixed to the casing 31, which comes into contact with the ground when the brush cutter 1 is dropped, even if the casing 31 experiences a large impact or vibration, the noise reduction component 8 is less likely to be affected by these shocks or vibrations, and is effectively prevented from shifting position, falling off, or being damaged. Furthermore, because the noise reduction component 8 is detachably attached to the support portion 72 provided on the air guide 7, the noise reduction component 8 can be removed when necessary. This makes it easy to adapt specifications to include or exclude the noise reduction component 8. Furthermore, in the unlikely event that an abnormality or malfunction occurs in the noise reduction component 8, only the noise reduction component 8 can be removed and replaced, providing excellent maintainability during the production process and repair stage.

[0020] As shown in FIGS. 3 and 5, the noise reduction component 8 includes a core member 81 made of a magnetic material. The constituent material (magnetic material) of the core member 81 is not particularly limited, but examples thereof include Fe, Co, Ni, Fe-based alloys, and ferrite, with ferrite being preferred because it is relatively inexpensive and has a high noise reduction effect. Examples of ferrite include NiZn ferrite, MnZn ferrite, MgZn ferrite, CuZn ferrite, MnMg ferrite, and MgMnSr ferrite. The core member 81 may be in the shape of a flat plate, but in this embodiment, it is preferable that it is in the shape of an annulus, as shown in Fig. 3 etc. The core member 81 is not limited to a circular annular shape, and may also be in the shape of a polygonal annulus.

[0021] The main body 3 further includes a plurality of wiring cables 9 electrically connected to the control board 6. Of the plurality of wiring cables 9, wiring cables 91 and 92 are inserted into the annular core member 81. 3, the movement of the annular core member 81 may be restricted by the air guide (cover member) 7 and the wiring cables 91, 92. This makes it possible to more reliably maintain the attachment state of the core member 81 to the air guide 7 without providing a movement restricting member to the casing 31 or preparing a separate part. In this embodiment, the annular core member 81 is inserted through the positive and negative wiring cables 91, 92 connected to the connection terminals of the battery B, but any wiring cable 9 with the highest noise reduction effect can be selected from the multiple wiring cables 9. This is an advantage of the core member 81 being fixed close to the control board 6. For example, even after actually operating the brush cutter 1 and confirming the noise reduction effect, the wiring cable 9 with the highest noise reduction effect can be selected without changing the shape of the casing 31 or the fixing position of the core member 81 or adding any other parts.

[0022] 3, the air guide (cover member) 7 further includes a support portion 72 that supports a core member 81 (noise reduction component 8) on its right side wall 71. Specifically, the support portion 72 has a pair of supports 721, 722 that protrude on the side opposite to the control board 6. One support member 721 is in the form of a narrow plate, and the other support member 722 is in the form of an arc corresponding to the inner shape of the annular core member 81. The pair of supports 721, 722 are configured to support the core member 81 (noise reduction component 8) between them. This configuration allows the core member 81 to be easily attached to and detached from the air guide 7. It also makes it possible to effectively utilize dead space within the casing 31 and to easily protect the core member 81 from external impacts. At least one of the pair of supports 721, 722 preferably has a protrusion that protrudes toward the noise reduction component 8 (in this embodiment, the peripheral surface of the core member 81). In this embodiment, as shown in FIG. 6(b), the support 721 has a pair of ridges 721a that protrude forward and extend in the left-right direction. Also, as shown in FIG. 6(a), the support 722 has a pair of ridges 722a that protrude rearward and extend in the left-right direction. This makes it difficult for the core member 81 to move or rotate, and the core member 81 is fixed more stably.

[0023] Furthermore, it is preferable that the noise reduction component 8 further includes a soft body (not shown) that covers the core member 81. This soft body comes into contact with the ridges 721a and 722a of the supports 721 and 722, making it difficult for the noise reduction component 8 to come off the pair of supports 721 and 722, i.e., the air guide 7. The soft body can be made of, for example, a fiber base material, a sponge (foam material), a rubber material, etc., but is preferably made of a fiber base material. In this case, the noise reduction component 8 is more likely to catch on the supports 721, 722 (sliding resistance), which can prevent the noise reduction component 8 from falling off the air guide 7. Examples of the fiber substrate include glass fiber substrate, resin fiber substrate, carbon fiber substrate, and metal fiber substrate.

[0024] Instead of being inserted into the annular core member 81, the distribution cables 91, 92 may be wound around the annular core member 81 or may be arranged alongside the flat core member 81. Furthermore, it may be provided in the following aspects.

[0025] (1) A work machine comprising a working unit and a main body connected to the working unit, the main body having a housing and a control board, a cover member and a noise reduction component disposed within the housing, the control board configured to control the operation of the working unit, the cover member disposed to cover the control board, and the noise reduction component attached to the cover member.

[0026] (2) The work machine described in (1) above, wherein the noise reduction component is detachably attached to the cover member.

[0027] (3) The work machine according to (1) or (2) above, wherein the noise reduction component includes a core member made of a magnetic material.

[0028] (4) The working machine described in (3) above, wherein the core member is annular.

[0029] (5) In the work machine described in (4) above, the main body further has a wiring cable that is electrically connected to the control board and is inserted into the annular core member.

[0030] (6) In the work machine described in (5) above, the movement of the annular core member is restricted by the cover member and the distribution cable.

[0031] (7) The work machine according to any one of (3) to (6) above, wherein the noise reduction component further includes a soft body that covers the core member.

[0032] (8) The work machine described in (7) above, wherein the soft body is made of a fiber base material.

[0033] (9) The work machine according to any one of (1) to (8) above, wherein the cover member further includes a support portion that supports the noise reduction component.

[0034] (10) In the work machine described in (9) above, the support portion has a pair of supports arranged to protrude on the opposite side to the control board, and the pair of supports are configured to support the noise reduction component between them.

[0035] (11) In the work machine described in (10) above, at least one of the pair of supports has a protrusion that protrudes toward the noise reduction component.

[0036] (12) In the work machine described in any one of (1) to (11) above, the cover member has a function of defining a flow path of air that contacts the control board. Of course, this is not the case.

[0037] As described above, various embodiments of the present invention have been described, but these are presented as examples and do not limit the scope of the invention in any way. The novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. Such embodiments and their modifications are intended to be included within the scope and spirit of the invention, as well as within the scope of the inventions and their equivalents as set forth in the claims. [Explanation of symbols]

[0038] 1: Brush cutter 2: Working section 21: Rotary blade 22: Rotation axis 23: Cover 3: Main body 31: Casing 32: Electric motor 321: Stator 322: Output shaft 323: Bearing 324: Bearing 33: Fan 4: Connection part 41: Grip 42: Operation stick 43: Drive transmission shaft 51: Safety bar 52: Handle 53: Operation section 6: Control board 61: Board body 62: Finn 7: Air guide 71: Right side wall 72: Support part 721 :Support 721a: Convex stripe 722 :Support 722a: Convex stripe 8: Noise reduction parts 81: Core member 9: Wiring cable 91: Wiring cable 92: Wiring cable B: Battery

Claims

1. A work machine, a working unit and a main body connected to the working unit; the main body has a housing, a control board, a cover member, and a noise reduction component disposed within the housing, the control board is configured to control the operation of the working unit; the cover member is disposed to cover the control board, The noise reduction component is attached to the cover member.

2. The work machine according to claim 1, The noise reduction component is detachably attached to the cover member.

3. The work machine according to claim 1, The noise reduction component includes a core member made of a magnetic material.

4. The work machine according to claim 3, The core member is annular.

5. The work machine according to claim 4, The main body further includes a wiring cable electrically connected to the control board and inserted through the annular core member.

6. The work machine according to claim 5, The movement of the annular core member is restricted by the cover member and the wiring cable.

7. The work machine according to claim 3, The noise reduction component further includes a soft body that covers the core member.

8. The work machine according to claim 7, The soft body is made of a fiber base material.

9. The work machine according to claim 1, The cover member further includes a support portion that supports the noise reduction component.

10. The work machine according to claim 9, the support portion has a pair of supports provided so as to protrude on the side opposite to the control board, The pair of supports are configured to support the noise reduction component therebetween.

11. The work machine according to claim 10, At least one of the pair of supports has a protrusion that protrudes toward the noise reduction component.

12. The work machine according to claim 1, The cover member has a function of defining a flow path for air that comes into contact with the control board.

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