Breather structure for work equipment

Abstract

To shorten a length of a breather tube, and to suppress the clogging of the breather tube caused by freezing.SOLUTION: A working machine (1) comprises a machine body 3, working parts (6, 7) arranged at the machine body 3, traveling parts (4) arranged at left and right sides of the machine body 3, and drive sources (10, 18) arranged at the machine body 3 so as to drive the working parts and the traveling parts. At least one gear case 41 for defining a gear chamber 42 which accommodates a gear 43 for connecting the drive sources to the traveling parts so as to be transmittable in power is arranged at the machine body 3. The drive sources include an engine 10 which is mounted to an upper part of the machine body 3. The other end 70b of the breather tube 70 having one end 70a communicating with the gear chamber 42 and the other end 70b opened to the outside is arranged in a space 50 which is formed between the machine body 3 and the engine 10.SELECTED DRAWING: Figure 3

Description

[Technical Field]

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

[0002] Generally, a gear case that houses a vehicle gearbox (transmission, etc.) is provided with a breather device that releases air to the outside through a breather chamber to prevent the air inside from becoming high pressure at high temperatures. Also, in electric vehicles, a motor case that houses an electric motor is provided with a separate breather device to prevent the air inside from becoming high pressure at high temperatures (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-161363 Summary of the Invention [Problem to be solved by the invention]

[0004] In electric vehicles, the gearbox and motor case are located in areas covered by the vehicle body. In recent years, hybrid-type work machines have been developed that have a motor as a propulsion source in addition to an engine as a drive source for the working section. Such work machines may not have a vehicle body that covers the propulsion source from above, as in electric vehicles. In such cases, the waterproof and dustproof properties of the breather tube are reduced. Therefore, in the past, the breather tube was extended from the gear case to, for example, an operation panel (input device) or a control device near the operation panel, and was positioned so that the other end was open inside the control panel.

[0005] However, from the viewpoint of reducing material consumption and facilitating handling, it is preferable to make the breather tube as short as possible. Also, when the work machine is used in cold regions, there is a risk of the tube becoming clogged due to frozen water. Therefore, it is preferable to position the breather tube in a location where it is least likely to freeze.

[0006] In view of the above background, an object of the present invention is to provide a breather structure for a work machine that can shorten the breather tube and prevent the breather tube from becoming clogged due to freezing. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems, one aspect of the present invention is a breather structure for a working machine (1), comprising a machine body (3), working units (6, 7) provided on the machine body for performing a predetermined task, running units (4) provided on the left and right sides of the machine body for traveling the machine, and a driving unit (6) for driving the working units and the running units. Drive The vehicle comprises a power source (10, 18), at least one gear case (41) provided on the vehicle body and defining a gear chamber (42) that houses a gear (43) that connects the power source to the traveling part so as to be able to transmit power, and a breather tube (70) having one end (70a) that communicates with the gear chamber and the other end (70b) that is open to the outside, the power source including an engine (10) mounted on the upper part of the vehicle body, and the other end of the breather tube being disposed in a space (50) formed between the vehicle body and the engine.

[0008] According to this aspect, one end of the breather tube communicates with a gear chamber of a gear case provided in the aircraft body, and the other end of the breather tube is disposed in a space formed between the aircraft body and the engine. Therefore, unlike conventional systems, it is not necessary to extend the breather tube from the gear case to, for example, an input device, and the breather tube can be short. Furthermore, because the other end of the breather tube is disposed in the space formed between the aircraft body and the engine, the breather tube is easily heated by the engine. Therefore, clogging of the breather tube due to freezing is suppressed.

[0009] In the above aspect, the upper part of the fuselage is provided with a pair of engine supports (46) that protrude upward to support the engine, and the space is defined on the upper surface of the fuselage from the left and right by the engine supports.

[0010] According to this aspect, the space is defined between a pair of engine supports provided on the upper part of the aircraft body and is covered by the engine supports from the left and right, thereby improving the waterproof and dustproof properties of the space.

[0011] In the above aspect, one of the engine support parts includes a support wall (47) having a through hole (47a) formed therein, and the breather tube is disposed to pass through the through hole.

[0012] According to this aspect, there is no need to provide a breather tube that bypasses the support wall of the engine support portion, and therefore the breather tube can be short.

[0013] In the above aspect, the space is defined by the front and rear walls (48) from one side in the fore-and-aft direction (rear) between the engine support parts, and is open to the other side in the fore-and-aft direction (front) between the engine support parts, and the other end of the breather tube faces the front and rear walls at a distance.

[0014] According to this aspect, the space is defined by the front and rear walls from one side in the front-rear direction, which further improves the waterproof and dustproof properties of the space. Also, since the space is open to the other side in the front-rear direction, even if water enters the space, it can be drained from the open portion.

[0015] In the above aspect, a tube holding plate (60) made of a plate extending from the upper part of the aircraft body is provided in the space, and the other end of the breather tube is fixed to the tube holding plate.

[0016] According to this aspect, the other end of the breather tube can be firmly fixed by the tube holding plate.

[0017] In the above aspect, the front and rear walls are inclined rearward, and the tube holding plate is inclined substantially parallel to the front and rear walls.

[0018] According to this aspect, since the tube holding plate is inclined substantially parallel to the front and rear walls, the holding angle of the other end of the breather tube can be inclined in accordance with the inclination of the front and rear walls.

[0019] In the above aspect, the other end of the breather tube is open to the space on the side of the lower surface of the tube holding plate.

[0020] According to this aspect, the other end of the breather tube is open at a position where it is covered from above by the tube holding plate, thereby preventing moisture and dust from entering the breather tube from the other end.

[0021] In the above embodiment, an upwardly opening access port (65) is formed between the front and rear walls and the tube holding plate, and the other end of the breather tube is fixed to the tube holding plate by a fixing member (76) arranged below the tube holding plate.

[0022] According to this aspect, an operator can insert his / her hand through the access opening below the tube holding plate and place the fixing member in a predetermined position below the tube holding plate, thereby facilitating assembly work.

[0023] In the above aspect, the driving source provided on the aircraft The space further includes at least one motor (18), and the bottom surface of the space has a bottom curved portion (61) that curves upward convexly along the at least one motor, and the other end of the breather tube is positioned higher than the upper end of the bottom curved portion.

[0024] According to this aspect, even if water accumulates in the space, the water flows downward over the upper end of the curved bottom portion. Since the other end of the breather tube is positioned higher than the upper end of the curved bottom portion, water is prevented from entering the breather tube.

[0025] In the above embodiment, the tube holding plate has a base (63) attached to the upper surface of the airframe, and the base has an opening (62) formed therein that aligns with a hole (55) provided on the upper surface of the airframe, a wire harness (54) connected to the motor passes through the hole and the opening, and a seal member (57) that holds the wire harness is attached to the opening.

[0026] According to this aspect, the plate for attaching the seal member also serves as the tube holding plate, eliminating the need for a dedicated tube holding plate for fixing the other end of the breather tube, thereby reducing the number of parts.

[0027] In the above embodiment, the breather tube has a loop-shaped portion (70c) that is curved convexly upward.

[0028] According to this aspect, even if oil in the gear case flows out from one end of the breather tube into the breather tube, the loop-shaped portion prevents the oil from flowing out. Also, even if water in the space flows into the breather tube, the loop-shaped portion prevents the water from flowing into the gear case.

[0029] In the above aspect, at least one of the gear cases includes a left gear case (41L) and a right gear case (41R) arranged widthwise between the left and right running portions with a gap therebetween, and the breather tube includes a left tube (71) connected to the left gear case, a right tube (72) connected to the right gear case, and a common tube (74) connected to the left tube and the right tube via teeth (73), and the common tube has the loop-shaped portion.

[0030] According to this aspect, the number of loop-shaped portions can be reduced, and the number of tubes whose other ends are fixed to the tube holding plate can also be reduced.

[0031] In the above aspect, the breather structure further includes a guard member (80) attached to the airframe and covering the one end of the breather tube from the outside.

[0032] According to this aspect, it is possible to prevent damage to the one end of the breather tube, water from entering through the one end of the breather tube, and the like.

[0033] In the above aspect, the engine further includes a motor breather tube (53) having one end (53a) communicating with the internal space of at least one of the motors and the other end (53b) open to the outside, and the other end of the motor breather tube is positioned in the space formed between the aircraft body and the engine.

[0034] According to this aspect, one end of the motor breather tube communicates with the internal space of the motor provided in the aircraft body, and the other end of the motor breather tube is disposed in the space formed between the aircraft body and the engine. Therefore, there is no need to extend the motor breather tube from the motor to, for example, an input device, and the motor breather tube can be short. Furthermore, because the other end of the motor breather tube is disposed in the space formed between the aircraft body and the engine, the motor breather tube is easily heated by the engine. Therefore, clogging of the motor breather tube due to freezing is suppressed.

[0035] In the above aspect, the other end of the motor breather tube is fixed to the tube holding plate.

[0036] According to this aspect, the other end of the motor breather tube can be firmly fixed by the tube holding plate. Also, by fixing the other end of both the motor breather tube and the other end of the breather tube to the tube holding plate, the other ends of both tubes can be arranged close to each other and the number of tube holding plates can be reduced.

[0037] In the above aspect, the motor breather tube is curved upwardly convexly.

[0038] According to this aspect, even if water in the space flows into the motor breather tube, the upwardly convex curved portion prevents the water from flowing into the motor.

[0039] In the above aspect, at least one of the motors includes a motor case (36) having a harness insertion hole (55) on its upper surface, and the motor breather tube is curved upwardly convexly above the harness insertion hole of the motor case.

[0040] According to this aspect, the space below the motor breather tube is utilized to arrange the wire harness, thereby enabling effective use of the space. [Effects of the Invention]

[0041] According to the above aspect, it is possible to provide a breather structure for a work machine that can shorten the breather tube and suppress clogging of the breather tube due to freezing. [Brief explanation of the drawings]

[0042] [Figure 1] Side view of a snow blower according to an embodiment [Figure 2] Side view of the main part of the snow blower shown in Figure 1 [Figure 3] Plan view of the aircraft shown in Figure 2 [Figure 4] A cross-sectional view of the aircraft taken along the line IV-IV in Figure 3. [Figure 5] Perspective view of the upper fuselage from the rear left [Figure 6] A partially cutaway perspective view of the upper fuselage from the rear left [Figure 7] Perspective view of the left side of the aircraft from the rear left DETAILED DESCRIPTION OF THE INVENTION

[0043] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In the following embodiment, the present invention is applied to a snow blower 1. Hereinafter, terms indicating directions such as front / rear, left / right, and up / down are used based on the direction as seen by the operator operating the snow blower 1. In the drawings, an arrow indicated by "Fr" points forward, and in Figures 3 and 4, an arrow indicated by "L" points left, and an arrow indicated by "R" points right.

[0044] 1 is a side view of a snow blower 1 according to an embodiment. First, the overall configuration of the snow blower 1 will be described with reference to FIG.

[0045] As shown in Figure 1, snow blower 1 is a walk-behind snow blower in which an operator walks behind to remove snow. Snow blower 1 has a body 3 that forms the framework of the snow blower, a pair of traveling devices 4 mounted on both the left and right sides of body 3, a handle device 5 mounted at the rear of body 3, a blower device 6 mounted at the front of body 3, and an auger device 7 mounted in front of blower device 6. Only the traveling device 4 mounted on the left side of body 3 is shown in Figure 1. The blower device 6 and auger device 7 form the working section of snow blower 1 that performs snow removal work.

[0046] An internal combustion engine (hereinafter referred to as "engine 10") serving as a drive source is supported on the upper part of the vehicle body 3. The engine 10 has a crankshaft 11 (only the front end of which is shown in FIG. 1) that can rotate about an axis that extends in the front-to-rear direction. Note that in other embodiments, the crankshaft 11 may be rotatable about an axis that extends in the up-down direction.

[0047] A transmission shaft 12 that can rotate around an axis extending in the front-rear direction is provided at the lower front of the machine body 3. The transmission shaft 12 is positioned lower than the crankshaft 11 and is connected to the crankshaft 11 via a reduction mechanism 13. The reduction mechanism 13 has a small-diameter drive pulley 13a connected to the crankshaft 11, a large-diameter driven pulley 13b connected to the transmission shaft 12, a belt 13c wound around both pulleys, and a tensioner (not shown).

[0048] Each traveling device 4 is an endless track having a driving wheel 15, a driven wheel 16 provided behind the driving wheel 15, and a crawler belt 17 wound around the driving wheel 15 and the driven wheel 16. Note that in other embodiments, the driven wheel 16 may be provided in front of the driving wheel 15, and the traveling device 4 does not have to be an endless track. Each traveling device 4 constitutes a traveling section of the snow blower 1 that propels the machine body 3. The machine body 3 is located between a pair of traveling devices 4. A traveling motor 18 is connected as a drive source to the driving wheels 15 of both traveling devices 4 via a drive shaft 19 that transmits driving force. At least one traveling motor 18 is required, and in this embodiment, two traveling motors 18 are provided, one on the left and one on the right (only the left traveling motor 18 is shown in FIG. 1).

[0049] The handle device 5 has left and right arms 20 (only the left arm 20 is shown in FIG. 1 ) that extend rearward and upward from the bottom of the machine body 3, and input devices 21 attached to the upper ends of the left and right arms 20. A grip 20a that is held by the operator is provided at the upper end of each arm 20. The input device 21 is a device that accepts input operations by the operator. The input device 21 has, for example, a travel lever 22 that accepts operations to travel the snow blower 1, a snow removal switch 23 that accepts operations to operate the blower device 6 and the auger device 7, and a deadman's clutch 24 located close to the grip 20a.

[0050] The blower device 6 has a blower housing 26 fixed to the front of the fuselage 3, a blower 27 housed in the blower housing 26, and a chute 28 extending upward from the upper end of the blower housing 26. The blower 27 is fixed to the rear of the transmission shaft 12.

[0051] The auger device 7 has an auger housing 31 fixed to the front of the blower housing 26, an auger shaft 33 rotatably supported on the auger housing 31 and connected to the transmission shaft 12 via a transmission 32, and an auger claw 34 fixed to the auger shaft 33.

[0052] Next, the overall operation of the snow blower 1 will be described.

[0053] When the operator operates the travel lever 22 of the input device 21 to drive the snow blower 1, the travel motor 18 of each travel device 4 rotates. The rotation of the travel motor 18 is transmitted to the drive wheels 15 via the drive shaft 19. This causes the crawler belts 17 to rotate, causing the snow blower 1 to travel.

[0054] Furthermore, when the operator operates the snow removal switch 23 of the input device 21 to operate the blower device 6 and the auger device 7, the crankshaft 11 of the engine 10 rotates. The rotation of the crankshaft 11 is transmitted to the transmission shaft 12 via the reduction gear mechanism 13, causing the transmission shaft 12 and the blower 27 to rotate together. The rotation of the transmission shaft 12 is transmitted to the auger shaft 33 via the transmission 32, causing the auger shaft 33 and the auger claws 34 to rotate together. As the auger claws 34 rotate, snow in front of the snow blower 1 is crushed by the auger claws 34 and collected in the center of the auger housing 31 in the left-right direction. The collected snow is introduced into the blower housing 26 and thrown in the desired direction by the blower 27 via the chute 28.

[0055] Next, the configuration of the breather structure of the snow blower 1 will be described in detail.

[0056] Fig. 2 is a side view of a main portion of the snow blower 1 shown in Fig. 1. As shown in Fig. 2, an electromagnetic clutch 37 is provided on the crankshaft 11 between the engine 10 and the drive pulley 13a of the reduction mechanism 13. Fig. 3 is a plan view of the machine body 3 shown in Fig. 2, and Fig. 4 is a cross-sectional view of the machine body 3 taken along the IV-IV cross-sectional line in Fig. 3. As shown in Figs. 2 to 4, the machine body 3 has a front portion that receives the lower portion (driven pulley 13b) of the reduction mechanism 13, a lower portion that constitutes the motor case 36 of the travel motor 18, and an upper portion that constitutes an engine bed on which the engine 10 is mounted.

[0057] As shown in Figure 4, in this embodiment, the two traction motors 18 are arranged coaxially and side by side. The motor cases 36 of the two traction motors 18 are integrally formed by the vehicle body 3. The internal spaces of both motor cases 36 are connected to each other. Each traction motor 18 has a stator 38 with an electromagnet housed in the motor case 36, and a rotor 39 with a permanent magnet rotatably arranged inside the stator 38.

[0058] A pair of gear cases 41 (left gear case 41L, right gear case 41R) are provided on both sides of the lower part of the machine body 3. Each gear case 41 cooperates with the lower part of the machine body 3 (motor case 36) to define a gear chamber 42 between the machine body 3. Each gear chamber 42 houses a gear 43 that connects the corresponding travel motor 18 to the corresponding travel device 4 so that power can be transmitted.

[0059] As shown in Figures 3 and 4, the engine bed for mounting the engine 10 is composed of a pair of engine support portions 46 that protrude upward from both sides of the motor case 36 to support the engine 10. Each engine support portion 46 includes a support wall 47 that extends in the front-to-rear and up-down directions. The rear portions of the support walls 47 are connected to each other by a rear wall 48. In other words, a space 50 is formed between the engine 10 and the upper part of the fuselage 3, more specifically, on the upper surface of the motor case 36 provided in the lower part of the fuselage 3, that is, between the fuselage 3 and the engine 10. The space 50 is defined by the support walls 47 from the left and right and by the rear wall 48 from the rear.

[0060] The front part of the fuselage 3 that receives the driven pulley 13b forms a pulley receiving space 51 that is deeper in front of the space 50, and the pulley receiving space 51 is open toward the front. In other words, the space 50 formed between the fuselage 3 and the engine 10 is open toward the front via the pulley receiving space 51 (FIG. 3).

[0061] Figure 5 is a perspective view of the upper body of the aircraft as seen from the rear left. Figure 6 is a partially cutaway perspective view of the upper body of the aircraft as seen from the rear left. As shown in Figures 3 to 6, a motor breather tube 53 is connected to the upper wall of the motor case 36 to allow air inside the motor case 36 that has become hot due to the operation of the travel motor 18 to escape to the outside. One end 53a of the motor breather tube 53 communicates with the internal space of the motor case 36, and the other end 53b of the motor breather tube 53 is open to the space 50 between the aircraft body 3 and the engine 10.

[0062] As shown in Figures 5 and 6, harness insertion holes 55 (Figure 6) are provided on the top surfaces of the two motor cases 36, i.e., on the bottom surfaces of the spaces 50, through which wire harnesses 54 for supplying electrodes to the electromagnets of the corresponding travel motors 18 are inserted. The two harness insertion holes 55 are located at positions spaced apart on the left and right. The entrances of the harness insertion holes 55 are positioned higher than the surrounding area by cylindrical portions 56 (Figure 6) that protrude from the top surface of the motor case 36. Plate members 60 for mounting seal members 57 (Figure 5) that keep the wire harnesses 54 liquid-tight are fastened to the top surface of each cylindrical portion 56 with bolts.

[0063] As shown in FIG. 6, the bottom surface of the space 50 has a curved bottom portion 61 at the rear that is curved upward convexly along the travel motor 18. The curved bottom portion 61 has an arc shape centered on the rotation axis of the travel motor 18. The rear wall 48 is inclined rearward from the rear end of the curved bottom portion 61 (i.e., tilted backward). The harness insertion hole 55 and the tubular portion 56 are located near the highest point of the curved bottom portion 61. Therefore, both plate members 60 are located at a position higher than the upper end of the curved bottom portion 61.

[0064] The plate member 60 located on the left has a flat shape with an opening 62 formed therein that aligns with the harness insertion hole 55, and extends generally horizontally on the tubular portion 56. The plate member 60 located on the right has a flat shape with an opening 62 formed therein that aligns with the harness insertion hole 55, and includes a base portion 63 that extends generally horizontally on the tubular portion 56, and an extension portion 64 that extends upward and diagonally rearward from the rear end of the base portion 63. This extension portion 64 extends from the tubular portion 56 provided on the upper part of the aircraft body 3 and supports the other end 53b of the motor breather tube 53. In other words, the other side of the plate member 60 functions as a tube holding plate. The extension portion 64 is inclined rearward generally parallel to the rear wall 48, and forms an access opening 65 that is open upward at its upper end between the extension portion 64 and the rear wall 48.

[0065] One end 53a of the motor breather tube 53 is located in front of the right harness insertion hole 55. The motor breather tube 53 extends upward from the one end 53a, curves convexly upward toward the rear, passes above the right harness insertion hole 55, and reaches the rear of the harness insertion hole 55. The other end 53b of the motor breather tube 53 abuts against the upper surface of the extension portion 64 of the right plate member 60 and is fixed to the extension portion 64 by a tubular first fixing member 66 inserted from the underside of the extension portion 64. As a result, the other end 53b of the motor breather tube 53 faces the rear wall 48 at a distance and is open to the space 50 on the underside of the plate member 60 via the first fixing member 66. The operation of fixing the other end 53b of the motor breather tube 53 using the first fixing member 66 can be performed through the access opening 65.

[0066] As shown in Fig. 4, a breather tube 70 is connected to the upper wall of each gear case 41 (41L, 41R) to release air to the outside via a breather chamber so that the air in the gear chamber 42 does not become high pressure at high temperatures. The breather tube 70 is bifurcated, with two ends 70a of the breather tube 70 communicating with the pair of gear chambers 42 and one end 70b of the breather tube 70 opening into the space 50 between the aircraft body 3 and the engine 10. The specific configuration of the breather tube 70 will be described below.

[0067] The breather tube 70 is configured in a bifurcated shape by including a left tube 71 connected to the left gear case 41L, a right tube 72 connected to the right gear case 41R, and a common tube 74 connected to the left tube 71 and the right tube 72 via teeth 73.

[0068] As shown in FIGS. 5 and 6, the left and right support walls 47 are provided with through-holes 47a penetrating in the thickness direction. Only the right-side through-hole 47a is shown in FIGS. 5 and 6. A grommet 75 made of an elastic material is attached to each through-hole 47a. In FIGS. 5 and 6, the lead wires of the through-holes 47a are attached to the holes of the grommets 75. As also shown in FIG. 4, the right tube 72 passes through the through-hole 47a of the grommet 75 attached to the right support wall 47 from one end 70a connected to the right gear case 41R and enters the space 50. The left tube 71 passes through the through-hole 47a of the grommet 75 attached to the left support wall 47 from one end 70a connected to the left gear case 41L and enters the space 50.

[0069] The teeth 73 linearly connect the left tube 71 and the right tube 72 below the extending portion 64 of the right plate member 60. The third connecting pipe portion of the teeth 73 is inserted from below into a hole formed in the extending portion 64. The common tube 74 is fixed to the extending portion 64 by inserting the third connecting pipe portion of the teeth 73 into the end that abuts against the extending portion 64 of the plate member 60 from the upper surface side. The other end of the common tube 74 forms the other end 70b of the breather tube 70.

[0070] The common tube 74 extends obliquely upward and forward from the end on the tooth 73 side, curves convexly upward toward the left, and has its other end 70b abutting against the upper surface of the extension portion 64 of the plate member 60. That is, the common tube 74 forms the loop-shaped portion 70c of the breather tube 70, which curves convexly upward. The other end 70b of the common tube 74 is fixed to the extension portion 64 by a tubular second fixing member 76 inserted from the underside of the extension portion 64. As a result, the other end 70b of the breather tube 70 faces the rear wall 48 at a distance and is open to the space 50 on the underside of the plate member 60 via the second fixing member 76. The operation of fixing the other end 70b of the breather tube 70 using the second fixing member 76 can also be performed through the access opening 65. The operation of fixing the left tube 71, the right tube 72, and the common tube 74 using the teeth 73 can also be performed through the access opening 65.

[0071] 7 is a perspective view of the left side of the aircraft body 3 as seen from the left rear. As shown in Figures 3 and 7, a pair of guard members 80 are attached to the aircraft body 3 so as to cover one end 70a of the left tube 71 and one end 70a of the right tube 72 from the outside. This prevents damage to the one end 70a of the breather tube 70 and prevents water from entering through the one end 70a of the breather tube 70.

[0072] The breather structure of the snow blower 1 is configured as described above. Next, the effects of the breather structure configured in this manner will be described.

[0073] As shown in FIGS. 3 to 6, one end 70a of the breather tube 70 communicates with the gear chamber 42, and the other end 70b of the breather tube 70 is disposed in the space 50 formed between the airframe 3 and the engine 10. This eliminates the need to extend the breather tube 70 from the gear case 41 to, for example, the input device 21, as in the conventional case, and allows the breather tube 70 to be short. Furthermore, because the other end 70b of the breather tube 70 is disposed in the space 50 formed between the airframe 3 and the engine 10, the breather tube 70 is more likely to receive heat from the engine 10. This prevents the breather tube 70 from becoming clogged due to freezing.

[0074] 3 and 4, the upper part of the fuselage 3 is provided with a pair of engine support parts 46 that protrude upward to support the engine 10, and a space 50 is defined on the upper surface of the fuselage 3 from the left and right by the engine support parts 46. As a result, the space 50 is defined between the pair of engine support parts 46 provided on the upper part of the fuselage 3 and is covered by the engine support parts 46 from the left and right. This improves the waterproof and dustproof properties of the space 50.

[0075] 5 and 6, the engine support portion 46 includes a support wall 47 having a through-hole 47a formed therein, and the breather tube 70 is disposed so as to pass through the through-hole 47a. This eliminates the need to provide the breather tube 70 so as to bypass the support wall 47 of the engine support portion 46. This allows the breather tube 70 to be short.

[0076] As shown in FIGS. 3 and 4 , the space 50 is defined by the rear wall 48 between the engine support portions 46 from the rear, i.e., from one side in the front-to-rear direction, and is open to the other side in the front-to-rear direction, i.e., from the front, between the engine support portions 46. Also, as shown in FIGS. 5 and 6 , the other end 70 b of the breather tube 70 faces the rear wall 48 at a distance. This defines the space 50 from the rear by the rear wall 48, further improving the waterproof and dustproof properties of the space 50. Furthermore, because the space 50 is open to the front, even if water enters the space 50, the water can be discharged from the open portion. In another embodiment, instead of providing the rear wall 48, the space 50 may be defined by the front and rear walls between the engine support portions 46 from the front and open to the rear.

[0077] A plate member 60 that extends from the upper part of the body 3 and constitutes a tube holding plate is provided in the space 50, and the other end 70b of the breather tube 70 is fixed to the plate member 60. As a result, the other end 70b of the breather tube 70 is firmly fixed by the plate member 60.

[0078] The rear wall 48 is tilted rearward, and the plate member 60 is tilted approximately parallel to the rear wall 48. As a result, the plate member 60 is tilted approximately parallel to the rear wall 48, so that the holding angle of the other end 70b of the breather tube 70 can be tilted in accordance with the tilt of the rear wall 48.

[0079] The other end 70b of the breather tube 70 is open to the space 50 on the underside of the plate member 60. As a result, the other end 70b of the breather tube 70 is open at a position covered by the plate member 60 from above. This prevents moisture and dust from entering the breather tube 70 from the other end 70b of the breather tube 70.

[0080] An access opening 65 that opens upward is formed between the rear wall 48 and the plate member 60, and the other end 70b of the breather tube 70 is fixed to the plate member 60 by a second fixing member 76 that is arranged below the plate member 60. This allows an operator to insert their hand below the plate member 60 through the access opening 65 and place the second fixing member 76 in a predetermined position below the plate member 60. This makes the assembly work easy.

[0081] The bottom surface of the space 50 has a curved bottom portion 61 that curves convexly upward along the travel motor 18, and the other end 70b of the breather tube 70 is positioned higher than the upper end of the curved bottom portion 61. As a result, even if water accumulates in the space 50, the water will flow downward over the upper end of the curved bottom portion 61. Because the other end 70b of the breather tube 70 is positioned higher than the upper end of the curved bottom portion 61, water is prevented from entering the breather tube 70.

[0082] The plate member 60 has a base 63 attached to the upper surface of the vehicle body 3, and the base 63 has an opening 62 formed therein that aligns with a harness insertion hole 55 provided on the upper surface of the vehicle body 3. A wire harness 54 connected to the travel motor 18 passes through the harness insertion hole 55 and the opening 62, and a seal member 57 that holds the wire harness 54 is attached to the opening 62. As a result, the plate member 60 for attaching the seal member 57 also serves as a tube holding plate. Therefore, there is no need to prepare a dedicated plate member 60 for fixing the other end 70b of the breather tube 70, reducing the number of parts.

[0083] The breather tube 70 has a loop-shaped portion 70c that is curved upwardly. As a result, even if oil in the gear case 41 flows out from one end 70a of the breather tube 70 into the breather tube 70, the loop-shaped portion 70c prevents the oil from flowing out. Furthermore, even if water in the space 50 flows into the breather tube 70, the loop-shaped portion 70c prevents the water from flowing into the gear case 41.

[0084] The gear case 41 includes a left gear case 41L and a right gear case 41R that are spaced apart in the width direction between the left and right traveling devices 4. The breather tube 70 includes a left tube 71 connected to the left gear case 41L, a right tube 72 connected to the right gear case 41R, and a common tube 74 connected to the left tube 71 and the right tube 72 via teeth 73. The common tube 74 has a loop-shaped portion 70c. This allows the number of loop-shaped portions 70c to be reduced. Also, the number of tubes whose other ends 70b are fixed to the plate member 60 can be reduced.

[0085] As shown in FIGS. 3 to 6, one end 53a of motor breather tube 53 communicates with the internal space of travel motor 18, and the other end 53b of motor breather tube 53 is disposed in space 50 formed between vehicle body 3 and engine 10. This eliminates the need to extend motor breather tube 53 to, for example, input device 21, allowing motor breather tube 53 to be short. Furthermore, because the other end 53b of motor breather tube 53 is disposed in space 50 formed between vehicle body 3 and engine 10, motor breather tube 53 is more likely to receive heat from engine 10. This prevents motor breather tube 53 from becoming clogged due to freezing.

[0086] 5 and 6, the other end 53b of the motor breather tube 53 is fixed to the plate member 60. This allows the other end 53b of the motor breather tube 53 to be firmly fixed by the plate member 60. Furthermore, by fixing both the other end 53b of the motor breather tube 53 and the other end 70b of the breather tube 70 to the plate member 60, these other ends 53b, 70b can be arranged close to each other, and the number of plate members 60 can be reduced.

[0087] The motor breather tube 53 is curved in an upward convex shape. As a result, even if water in the space 50 flows into the motor breather tube 53, the upward convex curve prevents the water from flowing into the travel motor 18.

[0088] The driving motor 18 includes a motor case 36 with a harness insertion hole 55 provided on the upper surface, and the motor breather tube 53 is curved upwardly convexly above the harness insertion hole 55 of the motor case 36. This allows the wire harness 54 to be placed in the space 50 below the motor breather tube 53, thereby making it possible to make effective use of the space.

[0089] Although the description of the specific embodiment has been completed above, the present invention is not limited to the above embodiment and its modifications, and can be implemented in a wide variety of modifications. For example, in the above embodiment, the present invention is applied to a snow blower 1, but the present invention may also be applied to working machines other than snow blowers, such as tillers, lawn mowers, and brush cutters. When the present invention is applied to a tiller, a tiller device suitable for tilling may be provided as the working unit instead of the blower device 6 and auger device 7 that constitute the snow removal working unit. When the present invention is applied to a lawn mower or brush cutter, a lawn mower or brush cutter equipped with a blade may be provided as the working unit under the machine body 3 instead of the snow removal working unit. [Explanation of symbols]

[0090] 1: Snow blower (an example of a work machine) 3: Aircraft 4: Running device (running part) 6: Blower device (working part) 7: Auger device (working part) 10: Engine 18:Traction motor 36: Motor case 41: Gear case 41L: Left gear case 41R: Right gear case 42: Gear room 43: Gear 46: Engine support 47 :Supporting wall 47a: Through hole 48: Rear wall (front and rear walls) 50: Space 53: Motor breather tube 53a: one end 53b: other end 54: Wire harness 55: Harness insertion hole 57: Sealing material 60: Plate member (tube holding plate) 61: Bottom curved part 62 :Aperture 63: Base 65: Access gate 70: Breather tube 70a: one end 70b: other end 70c: Loop-shaped section 71: Left tube 72: Right tube 73: Teeth 74: Common tube 76: Second fixing member 80: Guard material

Claims

1. A breather structure for a work machine, The aircraft and a working unit provided on the aircraft body for performing a predetermined task; running units provided on the left and right sides of the machine body for running the machine body; a drive source for driving the working unit and the traveling unit; at least one gear case provided on the vehicle body and defining a gear chamber that accommodates a gear that connects the drive source to the traveling unit in a power-transmittable manner; a breather tube having one end communicating with the gear chamber and the other end open to the outside, the drive source includes an engine mounted on an upper portion of the airframe and at least one motor provided on the airframe; the other end of the breather tube is disposed in a space formed between the airframe and the engine, A breather structure for a work machine, wherein the upper part of the machine body is provided with a pair of engine support portions that protrude upward to support the engine, and the space is defined on the upper surface of the machine body from the left and right by the engine support portions.

2. 2. The breather structure for a work machine according to claim 1, wherein one of the engine support portions includes a support wall having a through hole formed therein, and the breather tube is disposed so as to pass through the through hole.

3. 3. A breather structure for a work machine as described in claim 1 or 2, wherein the space is defined by a front-rear wall from one side in the front-rear direction between the engine support parts, and is open to the other side in the front-rear direction between the engine support parts, and the other end of the breather tube faces the front-rear wall at a distance.

4. 4. The breather structure for a work machine according to claim 3, wherein a tube holding plate made of a plate extending from the upper part of the machine body is provided in the space, and the other end of the breather tube is fixed to the tube holding plate.

5. 5. The breather structure for a work machine according to claim 4, wherein the front and rear walls are inclined rearward, and the tube holding plate is inclined substantially parallel to the front and rear walls.

6. 6. A breather structure for a work machine according to claim 5, wherein the other end of the breather tube is open to the space on the side of the lower surface of the tube holding plate.

7. 7. A breather structure for a work machine as described in claim 6, wherein an access opening that opens upward is formed between the front and rear walls and the tube holding plate, and the other end of the breather tube is fixed to the tube holding plate by a fixing member arranged below the tube holding plate.

8. A breather structure for a work machine described in any one of claims 4 to 7, wherein the bottom surface of the space has a bottom curved portion that curves convexly upward along at least one of the motors, and the other end of the breather tube is positioned at a higher position than the upper end of the bottom curved portion.

9. The breather structure for a work machine according to any one of claims 4 to 8, wherein the tube holding plate has a base attached to the upper surface of the machine body, the base has an opening formed therein that matches a hole provided on the upper surface of the machine body, a wire harness connected to the motor passes through the hole and the opening, and a seal member that holds the wire harness is attached to the opening.

10. 10. The breather structure for a work machine according to claim 1, wherein the breather tube has a loop-shaped portion that is curved convexly upward.

11. At least one of the gear cases includes a left gear case and a right gear case that are arranged between the left and right running portions and spaced apart in the width direction, 11. The breather structure of a work machine according to claim 10, wherein the breather tube includes a left tube connected to the left gear case, a right tube connected to the right gear case, and a common tube connected to the left tube and the right tube via teeth, and the common tube has the loop-shaped portion.

12. The breather structure for a work machine according to any one of claims 1 to 11, further comprising a guard member attached to the machine body and covering the one end of the breather tube from the outside.

13. A breather structure for a work machine according to any one of claims 4 to 9, further comprising a motor breather tube having one end communicating with the internal space of at least one of the motors and the other end open to the outside, the other end of the motor breather tube being positioned in the space formed between the machine body and the engine.

14. The breather structure for a work machine according to claim 13, wherein the other end of the motor breather tube is fixed to the tube holding plate.

15. 15. The breather structure for a work machine according to claim 13 or 14, wherein the motor breather tube is curved upwardly convexly.

16. A breather structure for a work machine described in any one of claims 13 to 15, wherein at least one of the motors includes a motor case having a harness insertion hole formed in the upper wall, and the motor breather tube is curved upwardly convexly above the harness insertion hole of the motor case.

17. A breather structure for a work machine, The aircraft and a working unit provided on the aircraft body for performing a predetermined task; running units provided on the left and right sides of the machine body for running the machine body; a drive source for driving the working unit and the traveling unit; at least one gear case provided on the vehicle body and defining a gear chamber that accommodates a gear that connects the drive source to the traveling unit in a power-transmittable manner; a breather tube having one end communicating with the gear chamber and the other end open to the outside, the drive source includes an engine mounted on an upper portion of the airframe and at least one motor provided on the airframe; the other end of the breather tube is disposed in a space formed between the airframe and the engine, The breather tube has a loop-shaped portion that is curved convexly upward, At least one of the gear cases includes a left gear case and a right gear case that are arranged between the left and right running portions and spaced apart in the width direction, A breather structure for a work machine, wherein the breather tube includes a left tube connected to the left gear case, a right tube connected to the right gear case, and a common tube connected to the left tube and the right tube via teeth, and the common tube has the loop-shaped portion.

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