Work equipment

Abstract

To provide a working machine which can blow out air-conditioned air, in which cool air and warm air generated by an air conditioner main body are sufficiently mixed, from a blowout port of a duct.SOLUTION: A working machine includes a machine body, a cabin mounted on the machine body, a driver seat arranged in the cabin, an air conditioner main body which generates air-conditioned air supplied in the cabin, and a duct structure which guides the air-conditioned air supplied from the air conditioner main body. The air conditioner main body generates the air-conditioned air for cooling or heating by mixing cool air and warm air. The duct structure includes: a first duct which distributes the air-conditioned air for cooling; a second duct which distributes the air-conditioned air for heating; a switching box which is connected to the first duct and second duct, and can switch between a first state for distributing the air-conditioned air supplied from the air conditioner main body to the first duct and a second state for distributing the same to the second duct; and a relay duct which connects the air conditioner main body and the switching box, and guides the air-conditioned air generated by the air conditioner main body to the switching box.SELECTED DRAWING: Figure 8

Description

[Technical field]

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

[0002] 2. Description of the Related Art A working machine disclosed in Patent Document 1 is known in the art. The work machine disclosed in Patent Document 1 is equipped with a duct that guides conditioned air from an air conditioner main body and sends it out into the cabin. This duct is configured by connecting multiple ducts and has multiple air outlets inside the cabin. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-116176 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned working machine, an air-mix type air conditioner main unit may be used, which generates conditioned air by mixing cold air and hot air. In this case, conditioned air in which cold air and hot air are not sufficiently mixed may be taken out of the air conditioner main unit, pass through a duct, and be blown out from an outlet. Therefore, there is a risk that conditioned air of different temperatures may be blown out from multiple outlets.

[0005] The present invention has been made in consideration of the above-mentioned problems, and its object is to provide a work machine that can blow out conditioned air at an appropriate temperature, which is a sufficient mixture of cold air and warm air generated by the air conditioner main body, from the duct outlet. [Means for solving the problem]

[0006] A work machine according to one aspect of the present invention includes a body, a cabin mounted on the body, a driver's seat disposed inside the cabin, an air conditioner main body that generates conditioned air to be supplied to the inside of the cabin, and a duct structure that guides the conditioned air supplied from the air conditioner main body. A control device disposed on the side of the driver's seat; the air conditioner main body mixes cold air and hot air to generate conditioned air for cooling or heating, the duct structure having a first duct for circulating conditioned air for cooling, a second duct for circulating conditioned air for heating, a switching box connected to the first duct and the second duct and having a switching unit capable of switching between a first state in which the conditioned air supplied from the air conditioner main body is circulated through the first duct and a second state in which the conditioned air is circulated through the second duct, and a relay duct connecting the air conditioner main body and the switching box and guiding the conditioned air generated by the air conditioner main body to the switching box. The first duct has a flat portion whose length in the fuselage width direction is shorter than its length in the front-rear direction, and the flat portion is disposed between the control device and an inner wall surface of the cabin on the side where the control device is disposed. The flat portion has a front outlet at its front portion that opens to the side of the driver's seat and above the control device, and a rear outlet at its rear portion that opens behind the driver's seat. . Effect of the Invention

[0007] According to the above configuration, when the conditioned air generated by the air conditioner main body is taken out in a state in which the cold air and the hot air are not sufficiently mixed, the cold air and the hot air can be sufficiently mixed in the relay duct before being guided to the switching box. Therefore, the switching box can be switched in a state in which the cold air and the hot air are sufficiently mixed. As a result, conditioned air for cooling or heating at an appropriate temperature in which the cold air and the hot air are sufficiently mixed can be guided from the switching box to the first duct or the second duct and blown out. [Brief description of the drawings]

[0008] [Figure 1] 1 is a schematic side view showing an overall configuration of a working machine. [Diagram 2] FIG. [Diagram 3] FIG. 2 is a schematic plan view showing the interior of the cabin. [Figure 4] FIG. 2 is a schematic side view showing the interior of the cabin. [Diagram 5] This is an oblique view of the cabin and the aircraft body as seen from the rear right. [Figure 6] This is an oblique view of the cabin and the aircraft body as seen from the rear left. [Figure 7] FIG. 2 is a rear view of the cabin and fuselage. [Figure 8] This is a plan cross-sectional view of the air conditioner body and duct structure. [Figure 9] FIG. 2 is a partial cross-sectional side view of the outside air duct, the inside / outside air switching device, and the air conditioner main body. [Figure 10] This is a plan view of the driver's seat, duct structure, air conditioner main body, outside air duct, inside / outside air switching device, etc. [Figure 11] This is an oblique view of the right steering device, duct structure, etc., seen from the left front. [Figure 12] FIG. [Figure 13] FIG. [Figure 14] 4 is a plan cross-sectional view showing the connection portion between the switching box and the relay duct, the first duct, and the second duct. FIG. [Figure 15] This is an oblique view of the right flight control device, the inner wall of the cabin, the first duct, etc., seen from the front left. [Figure 16] FIG. 4 is a perspective view showing the right steering device, the duct structure, and the cover member. [Figure 17] FIG. 2 is a perspective view of the rear surface of the cabin and the outside air duct as viewed from the left rear. [Figure 18] FIG. 2 is a perspective view showing a state in which the rear cover has been removed from the rear surface of the cabin. [Figure 19] FIG. 2 is a perspective view of the outside air duct, the first filter, the second filter, and the frame. [Figure 20] FIG. 2 is a front perspective view of the rear cover. [Figure 21] FIG. 4 is a rear view showing the state where the lid body is removed from the rear cover. [Figure 22] FIG. [Diagram 23] 11 is a perspective view showing a state in which a net body is housed in a case attached to a lid body. FIG. [Figure 24]11 is a perspective view showing a state in which a net body is being removed from a case attached to a lid body. FIG. [Diagram 25] FIG. [Figure 26] FIG. 4 is a vertical cross-sectional view of the rear cover, the lid body, the mesh body, and the case. [Figure 27] FIG. 4 is a plan view showing the state in which the lid is closed. [Figure 28] FIG. 4 is a plan view showing a state in which the lid is open. [Figure 29] FIG. 2 is a perspective view showing a first connection portion of one duct (first duct) and a second connection portion of the other duct (third duct). [Diagram 30] FIG. 4 is a cross-sectional view showing a state in which one duct (first duct) and the other duct (third duct) are connected. [Diagram 31] 11A to 11C are cross-sectional views illustrating a manufacturing method of the other duct. [Diagram 32] FIG. 4 is a cross-sectional view showing a state in which one duct (second duct) and the other duct (fourth duct) are connected. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a schematic side view showing the overall configuration of a working machine 1 according to this embodiment. Fig. 2 is a schematic plan view of the working machine 1. In this embodiment, a backhoe, which is a rotating working machine, is exemplified as the working machine 1. As shown in Figures 1 and 2, the working machine 1 includes a machine body (swivel base) 2, a traveling device 3, and a working device 4. Note that the working device 4 is omitted in Figure 2.

[0010] A cabin 5 is mounted on the machine body 2. A driver's seat 6 where an operator (driver) sits is provided inside (inside) the cabin 5. In other words, the driver's seat 6 is surrounded by the cabin 5. The driver's seat 6 has a seat portion 6A where the operator sits, and a backrest portion 6B where the operator's back is supported. In this embodiment, the direction toward the front of an operator seated in the driver's seat 6 of the work machine 1 (the direction of arrow A1 in Figs. 1 and 2) will be described as the forward direction, the direction toward the rear of the operator (the direction of arrow A2 in Figs. 1 and 2) as the rear direction, and the direction of arrow K1 in Figs. 1 and 2 as the fore-aft direction. Additionally, the direction toward the left side of the operator (the near side in Fig. 1, the direction of arrow B1 in Fig. 2) will be described as the leftward direction, and the direction toward the right side of the operator (the far side in Fig. 1, the direction of arrow B2 in Fig. 2) will be described as the rightward direction. Additionally, the horizontal direction perpendicular to the fore-aft direction K1 will be described as the machine body width direction K2 (see Fig. 2).

[0011] As shown in Figs. 1 and 2, the traveling device 3 is a crawler type traveling device that supports the machine body 2 so that it can travel. The traveling device 3 has a traveling frame 3A, a first traveling device 3L provided on the left side of the traveling frame 3A, and a second traveling device 3R provided on the right side of the traveling frame 3A. The first traveling device 3L and the second traveling device 3R are driven by a traveling motor M1 configured by a hydraulic motor (hydraulic actuator). In this embodiment, a crawler type traveling device 3 is used, but this is not limited to this, and a wheel type traveling device or the like may be used. A dozer device 7 is attached to the front of the traveling device 3 (see Fig. 1).

[0012] As shown in Fig. 1, the machine body 2 is supported on the traveling device 3 so as to be rotatable about a rotation axis X1, which is an axis extending in the vertical direction, via a rotation bearing 8. As shown in Fig. 2, a cabin 5 is mounted on the machine body 2 toward the left and front. As shown in Fig. 1, the machine body 2 has, at its front, a support bracket 9 and a swing bracket 10 that support the working device 4. The support bracket 9 is provided so as to protrude forward from the machine body 2. The swing bracket 10 is attached to the front of the support bracket 9 so as to be swingable around a vertical axis (an axis extending in the up-down direction).

[0013] As shown in Fig. 1, the working device 4 has a boom 11, an arm 12, and a bucket 13. The base of the boom 11 is pivotally attached to an upper portion of the swing bracket 10 so as to be rotatable about a horizontal axis (an axis extending in the machine body width direction K2). The arm 12 is pivotally attached to the tip side of the boom 11 so as to be rotatable about the horizontal axis. The bucket 13 is provided on the tip side of the arm 12 so as to be capable of scooping and dumping operations.

[0014] The work machine 1 can be equipped with other working tools (hydraulic attachments) that can be driven by a hydraulic actuator, instead of or in addition to the bucket 13. Examples of other working tools include a hydraulic breaker, a hydraulic crusher, an angle broom, an earth auger, a pallet fork, a sweeper, a mower, and a snow blower. The swing bracket 10 is capable of swinging by the extension and retraction of a swing cylinder C1. The boom 11 is capable of swinging by the extension and retraction of a boom cylinder C2. The arm 12 is capable of swinging by the extension and retraction of an arm cylinder C3. The bucket 13 is capable of scooping and dumping by the extension and retraction of a bucket cylinder C4. The swing cylinder C1, boom cylinder C2, arm cylinder C3, and bucket cylinder C4 are configured by hydraulic cylinders (hydraulic actuators).

[0015] Next, with reference to FIG. 2 etc., the layout and configuration of the main devices mounted on the work machine 1 will be roughly described. As shown in Figs. 1 and 2, a prime mover E1 is mounted on the rear of the aircraft body 2. The prime mover E1 is a diesel engine. The prime mover E1 may be a gasoline engine or an electric motor, or may be a hybrid type having an engine and an electric motor. A cooling fan 14 is attached to the right of the prime mover E1. The cooling fan 14 is driven by the prime mover E1 and generates cooling air that flows from right to left, that is, from the outside of the aircraft body 2 toward the prime mover E1.

[0016] A radiator 15, an oil cooler 16, and a fuel cooler 17 are arranged to the right of the cooling fan 14. The radiator 15 is a cooler that cools the coolant that cools the prime mover E1. The oil cooler 16 is a cooler that cools the return hydraulic oil from hydraulic actuators such as hydraulic cylinders and hydraulic motors. The fuel cooler 17 is a cooler that cools the fuel. These coolers are cooled by the cooling air sucked in by the cooling fan 14.

[0017] A compressor 18 driven by the prime mover E1 is disposed in front of the right part of the prime mover E1. The compressor 18 is a device constituting part of an air conditioning system (air conditioner) equipped to the work machine 1, and compresses a refrigerant (air conditioning gas) into a semi-liquid state. A fuel tank 19 is disposed in front of the compressor 18, the radiator 15, and the oil cooler 16. The fuel tank 19 is a tank that stores fuel for the prime mover E1. A battery 22 is disposed in front of the fuel tank 19. The battery 22 is a storage battery that supplies power to electrical equipment equipped in the work machine 1.

[0018] A condenser 23 and a receiver 24, which constitute part of the air conditioning system, are disposed in front of the battery 22. The condenser 23 is a device that dissipates heat from the refrigerant from the compressor 18 to liquefy it. More specifically, it is a cooler that cools the refrigerant that has been semi-liquidized by the compressor 18 to promote liquefaction. In this embodiment, the condenser 23 is an electric condenser that is cooled by an electric fan. The receiver 24 is a device that stores the refrigerant liquefied by the condenser 23, separates the refrigerant that could not be liquefied by the condenser 23 from the liquefied refrigerant, and removes moisture and impurities.

[0019] A hydraulic pump 25 is attached to one side (left side) of the prime mover E1. The hydraulic pump 25 is driven by the power of the prime mover E1. The hydraulic pump 25 discharges hydraulic oil (pressurized oil) and the like that drives hydraulic actuators such as hydraulic motors and hydraulic cylinders equipped in the work machine 1. A hydraulic oil tank 28 is disposed to the left of the prime mover E1. The hydraulic oil tank 28 is a tank that stores hydraulic oil. The hydraulic oil tank 28 is disposed below the driver's seat 6. Hydraulic oil is delivered from the hydraulic oil tank 28 to the hydraulic pump 25.

[0020] A control valve V1 is disposed in front of the hydraulic oil tank 28. The control valve V1 controls the flow rate of hydraulic oil supplied from the hydraulic pump 25 to hydraulic actuators that are provided in the work machine 1 and driven by the hydraulic oil. More specifically, the control valve V1 is a valve unit that aggregates each control valve that controls the flow rate of hydraulic oil supplied to each hydraulic actuator provided in the work machine 1.

[0021] 2 and 3, a left steering device 20 and a right steering device 21 are disposed on either side of the driver's seat 6. The left steering device 20 is disposed to the left of the driver's seat 6. The right steering device 21 is disposed to the right of the driver's seat 6. The right operation device 21 has a right operation lever 26 and a dozer operation lever 27. By operating the right operation lever 26, it is possible to control the control valves for the boom cylinder C2 and the bucket cylinder C4. By operating the dozer operation lever 27, it is possible to control the control valves for the dozer cylinder.

[0022] The right steering device 21 is a steering device that outputs an electric signal in response to the operation of the right operation lever 26 or the dozer operation lever 27. The right operation lever 26 is a joystick-type lever that can be swung forward and backward and left and right. The dozer operation lever 27 is a lever that can be swung forward and backward. The right steering device 21 is provided with a first detection device 32 (see FIG. 11) that detects the operation amount and operation direction of the right operation lever 26, and a second detection device (not shown) that detects the operation amount and operation direction of the dozer operation lever 27. The first detection device 32 outputs an electric signal that controls the control valves (solenoid valves) for the boom cylinder C2 and the bucket cylinder C4 in response to the operation amount and operation direction of the right operation lever 26. The second detection device outputs an electric signal that controls the control valves (solenoid valves) for the dozer cylinder in response to the operation amount and operation direction of the dozer operation lever 27.

[0023] The left steering device 20 has a left operation lever 30 and an unload lever 31. A control valve for operating the swing arm can be controlled by operating the left operation lever 30. A hydraulic actuator of the work machine 1 can be switched between an operable state and an inoperable state by operating the unload lever 31. As shown in Figs. 3 and 4, a display device 33 is provided to the right front of the driver's seat 6. The display device 33 has a panel (meter panel) such as a liquid crystal panel. The panel displays items such as an image of the surroundings of the work machine, the driving status, mode changes, various settings, and warnings. The panel also displays information necessary for machine settings such as remaining fuel, time (clock), height control settings, AI (auto idle) control settings, and arm limit settings as information related to the work machine. However, the display items displayed on the display device 33 described above are merely examples and are not limiting.

[0024] As shown in Figs. 2, 5 and 6, the machine body 2 has a cover device 43. The cover device 43 covers devices, parts, members, etc. mounted on a rotating base disposed under the machine body 2. The cover device 43 is configured to have a plurality of covers. The plurality of covers include a first cover 43A to an eighth cover 43H. Each cover is removable or openable / closable. The first cover 43A is disposed at the front right part of the fuselage 2 and covers the condenser 23 and the receiver 24. The second cover 43B is disposed behind the first cover 43A and covers the upper parts of the fuel tank 19 and the battery 22. The third cover 43C covers the right side of the fuel tank 19 and the battery 22. The fourth cover 43D covers the upper parts of the radiator 15, the oil cooler 16, and the fuel cooler 17 and the parts extending from the right side to the rear. The fourth cover 43D has an opening 44 for taking in outside air by driving the cooling fan 14.

[0025] The fifth cover 43E covers the cooling fan 14 and the radiator 15 from above. The sixth cover 43F covers the rear of the prime mover E1. A weight 35 is provided below the sixth cover 43F. The seventh cover 43G covers the left side of the upper part of the hydraulic oil tank 28. The eighth cover 43H is disposed below the seventh cover 43G and covers the left side of the lower part of the hydraulic oil tank 28.

[0026] As shown in Figures 1 and 2, an air conditioner main body 29 is disposed above the prime mover E1 and the hydraulic pump 25. As shown in Figure 1, the air conditioner main body 29 is disposed above the prime mover room (engine room) E2 that houses the prime mover E1. The air conditioner main body 29 is also disposed behind the driver's seat 6. By disposing the air conditioner main body 29, which was conventionally installed below the driver's seat 6, above the prime mover room E2 and behind the driver's seat 6, it is possible to increase the space under the operator's feet.

[0027] The air conditioner main body 29 is a device that constitutes the main body of the air conditioning system. The air conditioner main body 29 generates conditioned air (temperature-adjusted air) to be supplied to the inside of the cabin 5. 5, 6 and 7, an outside air inlet 34 is provided on the rear side of the cabin 5 to take in outside air to be introduced into the air conditioner main body 29. The air conditioner main body 29 takes in air (outside air) introduced from the outside air inlet 34 or air (inside air) inside the cabin 5, and generates temperature-adjusted air (conditioned air) from the taken-in air.

[0028] As shown in Fig. 8, air conditioner main body 29 has housing 29A, and evaporator 29B, heater core 29C, blower fan 29D, etc., which are arranged inside housing 29A. Housing 29A is provided with intake port 29A1 and exhaust port 29A2. Intake port 29A1 is provided in the upper part of housing 29A (above blower fan 29D) (see Fig. 9). Exhaust port 29A2 is provided in the right part of housing 29A. Wind generated by driving blower fan 29D is taken into housing 29A from intake port 29A1 and taken out of housing 29A from exhaust port 29A2.

[0029] In the air conditioning system including the air conditioner main body 29, the refrigerant from the receiver 24 is injected from the expansion valve into the evaporator 29B and vaporized, the evaporator 29B is cooled by the vaporized refrigerant, and cold air is generated by passing the wind of the blower fan 29D through the evaporator 29B. The refrigerant leaving the evaporator 29B returns to the compressor 18. The heating system of the air conditioning system uses the heat of the prime mover E1. Specifically, high-temperature water heated by the heat of the prime mover E1 is used as a heat medium to warm the heater core 29C, and hot air is generated by passing the wind of the blower fan 29D through the heater core 29C.

[0030] The air conditioner main body 29 uses an air mix type that mixes cold air and hot air to generate conditioned air for cooling or heating. A first air mix door 29E and a second air mix door 29F are provided in a housing 29A of the air conditioner main body 29. The first air mix door 29E can swing around a first swing shaft 29G. The second air mix door 29F can swing around a second swing shaft 29H.

[0031] When the first air mix door 29E and the second air mix door 29F are both in the position shown by the solid line (first state), the flow of air from the blower fan 29D becomes a first flow F1 that passes through the evaporator 29B but does not pass through the heater core 29C. The first flow F1 passes through the evaporator 29B and is cooled, but does not pass through the heater core 29C, so it becomes cold air.

[0032] When the first air mix door 29E and the second air mix door 29F are both in the position shown by the imaginary line (second state), the air flow of the blower fan 29D becomes a second flow F2 that passes through the evaporator 29B and the heater core 29C. After passing through the evaporator 29B, the second flow F2 passes through the heater core 29C and is heated, becoming hot air. When the first air mix door 29E is in the position shown by the solid line and the second air mix door 29F is in the position shown by the imaginary line (third state), the wind of the blower fan 29D becomes both the first flow F1 and the second flow F2. As described above, the first flow F1 is cool air and the second flow F2 is warm air.

[0033] The air conditioner main body 29 generates conditioned air for cooling or heating by using cold air (first flow) generated by passing through the evaporator 29B and hot air (second flow) generated by passing through the evaporator 29B and the heater core 29C. The temperature of the conditioned air generated by the air conditioner main body 29 can be adjusted in the third state by adjusting the angle of the air mix door (first air mix door 29E, second air mix door 29F) to change the ratio between the amount of air in the first flow F1 and the amount of air in the second flow F2. When the amount of air in the first flow F1 is increased and the amount of air in the second flow F2 is decreased, the temperature of the conditioned air generated by the air conditioner main body 29 decreases. When the amount of air in the first flow F1 is decreased and the amount of air in the second flow F2 is increased, the temperature of the conditioned air generated by the air conditioner main body 29 increases. This allows the air conditioner main body 29 to generate conditioned air for cooling (air whose temperature is adjusted for cooling) and conditioned air for heating (air whose temperature is adjusted for heating). Hereinafter, air whose temperature is adjusted for cooling is referred to as "conditioned cold air" and air whose temperature is adjusted for heating is referred to as "conditioned warm air".

[0034] As shown in FIG. 8, a first flow F1 of air (cold air generated by passing through the evaporator 29B) and a second flow F2 of air (hot air generated by passing through the evaporator 29B and the heater core 29C) are taken out from the exhaust port 29A2 of the housing 29A. The exhaust port 29A2 opens facing one side (right side) in the width direction of the body. The air of the first flow F1 (cold air generated by passing through the evaporator 29B) is taken out from the rear of the exhaust port 29A2. The air of the second flow F2 (hot air generated by passing through the evaporator 29B and the heater core 29C) is taken out from the front of the exhaust port 29A2. In other words, the cold air and hot air taken out from the exhaust port 29A2 are taken out from different positions (positions shifted in the front-rear direction) in the exhaust port 29A2. Therefore, the conditioned air taken out from the air conditioner main body 29 is in a state in which the cold air and the hot air are not sufficiently mixed together at the time of taking out.

[0035] As shown in Figures 8, 10, etc., a duct structure 50 is connected to the air conditioner main body 29. The duct structure 50 guides the conditioned air supplied from the air conditioner main body 29. The duct structure 50 is connected to an exhaust port 29A2 of a housing 29A of the air conditioner main body 29. The internal space of the duct structure 50 communicates with the exhaust port 29A2. The duct structure 50 forms a passage that guides the conditioned air generated by the air conditioner main body 29 into the cabin 5.

[0036] 3 and 10, the duct structure 50 passes to the side (right side) of the driver's seat 6 and extends from behind the driver's seat 6 to in front of the driver's seat 6. Also, as shown in Figures 4, 11, etc., the duct structure 50 passes below (near the bottom of) the right steering device 21 and extends in the front-to-rear direction. The right steering device 21 is equipped with operating members such as a right operation lever 26 and a dozer operation lever 27, detection devices (first detection device 32, second detection device, etc.) that detect the operation of the operating members and output electric signals, and a mounting plate 36 to which the operating members and detection devices are attached. The duct structure 50 passes below the operating members, detection devices, mounting plate 36, etc. that constitute the right steering device 21 and extends in the front-rear direction.

[0037] As described above, the right steering device 21 is an electrically controlled steering device that outputs an electric signal in response to the operation of the right operation lever 26 or the dozer operation lever 27. Therefore, a hose (pilot hose) for circulating hydraulic oil (pilot oil) used for control by the operation of the right operation lever 26 is not connected to the right steering device 21. For this reason, no pilot hose is arranged below the right steering device 21. Therefore, a space is formed below the right steering device 21 due to the omission of the pilot hose, and the duct structure 50 can be arranged in this space.

[0038] As shown in FIGS. 8, 10, 12 and 13, the duct structure 50 has a relay duct 51, a switching box 52, a first duct 53, a second duct 54, a third duct 55 and a fourth duct 56. The relay duct 51 connects the air conditioner main body 29 and the switching box 52. As shown in Fig. 8, one end 51d of the relay duct 51 is connected to the exhaust port 29A2 of the air conditioner main body 29. The other end 51e of the relay duct 51 is connected to the switching box 52.

[0039] 3 and 10, the relay duct 51 is disposed rearward of the seat portion 6A of the driver's seat 6. One end of the relay duct 51 is located rearward of the driver's seat 6 in the front-rear direction. The other end of the relay duct 51 overlaps with the driver's seat 6 in the front-rear direction. More specifically, the other end of the relay duct 51 overlaps with the backrest portion 6B of the driver's seat 6 in the front-rear direction.

[0040] The relay duct 51 mixes the cold air and the hot air taken out from the exhaust port 29A2 of the air conditioner main body 29 and guides them to the switching box 52. In other words, the relay duct 51 has a length sufficient for mixing the cold air and the hot air taken out from the exhaust port 29A2 of the air conditioner main body 29 (a length capable of mixing them). As a result, as shown in FIG. 8, the flow F1 of the cold air and the flow F2 of the hot air become a flow F3 that is sufficiently mixed while passing through the relay duct 51. Therefore, the air introduced into the switching box 52 through the relay duct 51 becomes conditioned air in which the cold air and the hot air are sufficiently mixed. In other words, the space inside the relay duct 51 functions as an approach space for sufficiently mixing the cold air and the hot air from the air conditioner main body 29 to the switching box 52.

[0041] As shown in Figures 8 and 10, relay duct 51 curves and extends forward from the portion connected to exhaust port 29A2 of air-conditioner main body 29. As shown in Figures 4 and 12, relay duct 51 is inclined so as to transition downward as it extends forward. In this manner, relay duct 51 is curved and inclined, so that cool air and hot air are easily mixed.

[0042] 8, relay duct 51 has an expanded flow passage section 51f in which the flow passage cross-sectional area expands from the air conditioner main body 29 side toward the switching box 52 side. In other words, the flow passage cross-sectional area of ​​the other end of relay duct 51 is wider than the flow passage cross-sectional area of ​​exhaust port 29A2 of air conditioner main body 29. This causes the flow speed of air flowing through relay duct 51 to decrease toward switching box 52. This makes it possible to more reliably mix cool air and warm air.

[0043] As shown in FIG. 4, FIG. 10, FIG. 12, etc., relay duct 51 is provided with upper extension portion 51a extending upward. Upper extension portion 51a is provided at the rear of relay duct 51 (near exhaust port 29A2). Lid 51b is provided at the upper end of upper extension portion 51a. First through hole 51c is formed in lid 51b. Above lid 51b of upper extension portion 51a, cup holder 57 (see FIG. 3) capable of holding a beverage container or the like is provided. The bottom surface of cup holder 57 is disposed above lid 51b. Second through hole 57a is formed in the bottom surface of cup holder 57. A part of the conditioned air taken out from exhaust port 29A2 of air conditioner main body 29 is guided to upper extension portion 51a, and is discharged into cup holder 57 through first through hole 51c and second through hole 57a. This allows the beverage container held in cup holder 57 to be cooled or heated.

[0044] As shown in Figs. 8, 10 and 12, the switching box 52 is connected to the relay duct 51, the first duct 53 and the second duct 54. As shown in Fig. 13, the switching box 52 has a rear connection port 52a, a front connection port 52b and a side connection port 52c. The rear connection port 52a opens toward the rear. The front connection port 52b opens toward the front. The side connection port 52c opens toward the left front. The rear connection port 52a is connected to the relay duct 51. The front connection port 52b is connected to the first duct 53. The side connection port 52c is connected to the second duct 54.

[0045] 3 and 10, the switching box 52 is disposed to the side (right side) of the driver's seat 6. As shown in Fig. 4, a part or the whole of the switching box 52 is located in a position overlapping with the driver's seat 6 in a side view. In addition, the switching box 52 is disposed below the right steering device 21. 8 and 14, the switching box 52 has a switching unit 52d that can switch between a first state in which the switching box 52 communicates with the first duct 53 and a second state in which the switching box 52 communicates with the second duct 54. The first state in which the switching box 52 communicates with the first duct 53 is a state in which the conditioned air supplied from the air-conditioner main body 29 is allowed to flow through the first duct 53. The second state in which the switching box 52 communicates with the second duct 54 is a state in which the conditioned air supplied from the air-conditioner main body 29 is allowed to flow through the second duct 54.

[0046] The switching portion 52d has a swing plate 52f that can swing around the support shaft 52e. The swing plate 52f is configured to be swingable between a first position (position shown by a solid line) where the side connection port 52c is closed and the front connection port 52b is open, and a second position (position shown by a virtual line) where the front connection port 52b is closed and the side connection port 52c is open. When the rocking plate 52f is in the first position, the switching box 52 is in a first state in which it communicates with the first duct 53. When the rocking plate 52f is in the second position, the switching box 52 is in a second state in which it communicates with the second duct 54. When conditioned cool air flows through the relay duct 51, the switching box 52 is in the first state, and the conditioned cool air flows from the front connection port 52b to the first duct 53. When conditioned warm air flows through the relay duct 51, the switching box 52 is in the second state, and the conditioned warm air flows from the side connection port 52c to the second duct 54.

[0047] The rocking plate 52f is rocked by an electric drive mechanism such as an electric motor. The drive mechanism is driven by an operator operating an operation switch (not shown) disposed near the driver's seat 6. The operation switch is, for example, a switch for switching between a cooling mode and a heating mode. When the operator switches the operation switch to the cooling mode, the rocking plate 52f is set to the first position, and cool air for cooling flows from the switching box 52 to the first duct 53. At this time, conditioned cool air is generated in the air conditioner main body 29, and this conditioned cool air is supplied to the switching box 52 via the relay duct 51.

[0048] When the operator switches the operation switch to the heating mode, the rocking plate 52f is set to the second position, and warm air for heating flows from the switching box 52 to the second duct 54. At this time, conditioned warm air is generated in the air conditioner main body 29, and this conditioned warm air is supplied to the switching box 52 via the relay duct 51. The first duct 53 circulates the conditioned cool air taken out from the switching box 52. The first duct 53 connects the switching box 52 and the third duct 55. As shown in Fig. 12, the first duct 53 is arranged alongside the relay duct 51, the switching box 52, and the second duct 54 in the width direction of the aircraft body.

[0049] 12 and 13, the first duct 53 has a first portion 53a, a second portion 53b, and a third portion 53c. The first portion 53a, the second portion 53b, and the third portion 53c are configured as an integral body, and their internal spaces are in communication with each other. The first portion 53a is formed in a rectangular tube shape and extends long in the front-rear direction. The rear end of the first portion 53a is connected to the switching box 52, and the front end is connected to the third duct 55. In other words, the first portion 53a is a connection portion that connects the switching box 52 and the third duct 55 disposed in front of the first duct 53. The first portion 53a is inclined so as to transition downward toward the front.

[0050] The second portion 53b is a portion that connects the first portion 53a and the third portion 53c. The second portion 53b extends laterally (to the right) from the side surface (right side surface) of the rear portion of the first portion 53a, and then curves and extends upward. The third portion 53c extends upward from the upper end of the second portion 53b. The third portion 53c is a flat portion whose length in the width direction of the aircraft is shorter than its length in the front-rear direction. As shown in FIG. 15, the third portion 53c is disposed between the right pilot 21 and the inner wall surface 5a of the cabin 5. The third portion 53c extends in the up-down direction between the right pilot 21 and the inner wall surface (right wall surface) 5a of the cabin 5 on the side where the right pilot 21 is disposed. In other words, the third portion (flat portion) 53c rises upward from the first portion (main body portion) 53a along the inner wall surface 5a of the cabin 4. The length of the third portion (flat portion) 53c in the width direction of the aircraft is shorter than the length of the first portion (main body portion) 53a in the width direction of the aircraft.

[0051] A cutout portion 36a is formed in the right portion (the inner wall surface 5a side) of the mounting plate 36 of the right steering device 21 toward the left (the driver's seat 6 side), and the third portion 53c fits into the cutout portion 36a. As shown in Figs. 12 and 13, the third portion 53c extends rearward beyond the first portion 53a. As shown in Fig. 10, the third portion 53c extends rearward beyond the driver's seat 6.

[0052] As shown in Figures 3, 4, 10, 13, 15, etc., the first duct 53 has a first outlet 53d. The first outlet 53d is an outlet that blows out conditioned cool air. The first outlet 53d includes a front outlet 53d1 and a rear outlet 53d2. The front outlet 53d1 is provided in the front upper part of the third part 53c. The rear outlet 53d2 is provided in the rear upper part of the third part 53c.

[0053] As shown in FIG. 3 and FIG. 10, the front air outlet 53d1 is disposed to the side (right side) of the driver's seat 6. Also, as shown in FIG. 4, the front air outlet 53d1 is disposed above the right steering device 21. The front-rear position of the front air outlet 53d1 overlaps with the seat part 6A of the driver's seat 6. More specifically, the front end of the front air outlet 53d1 is behind the front end of the seat part 6A, and the rear end of the front air outlet 53d1 is forward of the rear end of the seat part 6A. The up-down position (height) of the front air outlet 53d1 overlaps with the backrest part 6B of the driver's seat 6. As shown in FIG. 12, the front air outlet 53d1 opens toward the upper left.

[0054] The front air outlet 53d1 provided on the right side of the seat portion 5A of the driver's seat 6 blows out cool air toward the upper left (upward toward the driver's seat 6) (see arrow Y1 in Figs. 3, 4, and 10). As a result, the cool air is blown out toward the face (front of the face) of the operator OP sitting in the driver's seat 6. By blowing out the cool air toward the face of the operator OP in this way, the operator OP can feel a strong sense of coolness.

[0055] As shown in Figs. 3 and 4, the rear air outlet 53d2 is disposed rearward of the driver's seat 6. As shown in Fig. 3, the rear air outlet 53d2 is disposed to the right of the driver's seat 6. In other words, the rear air outlet 53d2 is disposed to the right rear of the driver's seat 6. Also, as shown in Fig. 4, the rear air outlet 53d2 is disposed above the right steering device 21. The vertical position (height) of the rear air outlet 53d2 overlaps with the backrest 6B of the driver's seat 6. The rear air outlet 53d2 opens upward. An air outlet tube 58 is attached to the rear air outlet 53d2. The air outlet tube 58 opens forward and upward.

[0056] The conditioned cool air is blown out toward the upper front from the rear air outlet 53d2 provided at the right rear of the seat 5A of the driver's seat 6 through the air outlet tube 58 (see arrow Y2 in Figs. 3, 4, and 10). As a result, the conditioned cool air is blown out toward the back of the head of the operator OP sitting in the driver's seat 6. The second duct 54 is a duct that circulates the conditioned warm air taken out from the switching box 52. The rear end of the second duct 54 is connected to the side connection port 52c of the switching box 52. The front end of the second duct 54 is connected to the fourth duct 56. As shown in FIG. 4, the second duct 54 is inclined so as to transition downward toward the front. In addition, the second duct 54 is disposed below the right pilot 21. As shown in FIGS. 8, 10, and 12, the second duct 54 is disposed side by side with the first portion 53a of the first duct 53 in the fuselage width direction.

[0057] The third duct 55 is a duct that guides the conditioned cool air that has flowed through the first duct 53 further forward. As shown in Figs. 3, 4, 10, and 12, the third duct 55 extends forward from the front end of the first duct 53, then bends and extends upward (upward and forward). The third duct 55 has a second outlet 55a. The second outlet 55a is an outlet that blows out the conditioned cool air. The second outlet 55a is disposed in front of the driver's seat 6. As shown in Fig. 4, the vertical position (height) of the second outlet 55a overlaps with the seat portion 6A of the driver's seat 6, and is at a height near the seat surface of the seat portion 6A. The second outlet 55a opens toward the left (or rear left) at the right front of the driver's seat 6. The second air outlet 55a blows out conditioned cool air toward the front of the legs (near the knees) of an operator OP sitting in the driver's seat 6 (see arrow Y12 in FIGS. 3, 4 and 10).

[0058] The fourth duct 56 is a duct that guides the conditioned warm air that has flowed through the second duct 54 further forward. As shown in Figs. 3, 4, 10, and 12, the fourth duct 56 extends forward from the front end of the second duct 54, then bends and extends upward. The fourth duct 56 has a third outlet 56a. The third outlet 56a is an outlet that blows out the conditioned warm air. The third outlet 56a is disposed in front of the driver's seat 6. The third outlet 56a includes a lower outlet 56a1, a side outlet 56a2, and an upper outlet 56a3.

[0059] As shown in Fig. 4, the position of the lower air outlet 56a1 in the up-down direction is lower than the seat portion 6A of the driver's seat 6. The lower air outlet 56a1 opens facing downward (lower left). The conditioned warm air blown out from the lower air outlet 56a1 flows toward the feet of the operator sitting in the driver's seat 6 (see arrow Y13 in Fig. 4). As shown in FIG. 4 and other figures, the side air outlet 56a2 is disposed forward of the second air outlet 55a and the lower air outlet 56a1. The vertical position of the side air outlet 56a2 is lower than the seat surface of the seat portion 5A of the driver's seat 6. The side air outlet 56a2 opens toward the left front. The side air outlet 56a2 is an air outlet for a defroster. Warm air conditioned air is blown out from the side air outlet 56a2 toward the left front (see arrow Y14 in FIG. 4). This can eliminate fogging of the front window of the cabin 5.

[0060] As shown in FIG. 4 and other figures, the upper air outlet 56a3 is disposed forward of the second air outlet 55a and the lower air outlet 56a1. The upper air outlet 56a3 is located above the second air outlet 55a in the vertical direction. The upper air outlet 56a3 opens toward the left front. The upper air outlet 56a3 is an air outlet for a defroster. The upper air outlet 56a3 blows out conditioned warm air toward the left front (see arrow Y15 in FIG. 3, FIG. 4, and FIG. 10). This can eliminate fogging of the front window of the cabin 5.

[0061] As shown in Figures 3, 4, 11 and 15, the work machine 1 is provided with a cover member 60 that covers the duct structure 50. As shown in Figure 16, the cover member 60 includes a first cover member 61, a second cover member 62, a third cover member 63 and a fourth cover member 64. Note that Figure 4 shows only the third cover member 63, and Figure 15 shows only the second cover member 62.

[0062] The first cover member 61 covers the front part of the duct structure 50. The first cover member 61 covers the periphery of the third duct 55 and the fourth duct 56. As shown in FIG. 11, the first cover member 61 has a first ventilation hole 61a, a second ventilation hole 61b, a third ventilation hole 61c, and a fourth ventilation hole 61d. The first ventilation hole 61a is provided at a position corresponding to the lower outlet 56a1. The second ventilation hole 61b is provided at the side outlet 56a2. The third ventilation hole 61c is provided at a position corresponding to the upper outlet 56a3. The fourth ventilation hole 61d is provided at a position corresponding to the second outlet 55a. The display device 33 is attached to the upper end of the first cover member 61 via a bracket 37 (see FIG. 11, etc.).

[0063] The second cover member 62 covers the left side of the first portion 53a of the first duct 53, the left side of the second duct 54, the left side of the switching box 52, and the left side of the front part of the relay duct 51. The second cover member 62 covers the left side of the portion of the duct structure 50 that is disposed below the right steering device 21. The third cover member 63 covers the left and upper sides of the second portion 53b of the first duct 53. The third cover member 63 covers a portion of the second portion 53b that is exposed above the right operating device 21. The third cover member 63 has a fourth ventilation port 63a at a position corresponding to the front outlet 53d1.

[0064] The fourth cover member 64 covers the left and upper part of the rear part of the relay duct 51 and the upper part of the rear part of the first duct 53. The fourth cover member 64 is disposed behind the right operating device 21. The fourth cover member 64 has a first opening 64a at a position corresponding to the blowing tube 58, and a second opening 64b at a position corresponding to the cup holder 57. Covering the duct structure 50 with the cover member 60 can prevent damage and deformation of the duct structure 50. Also, temperature changes of the conditioned air flowing through the duct structure 50 can be suppressed.

[0065] As shown in Figures 9 and 10, the air conditioner main body 29 is connected to an inside / outside air switching device 65. The inside / outside air switching device 65 is connected to an air intake 29A1 of a housing 29A of the air conditioner main body 29. The inside / outside air switching device 65 is disposed above a blower fan 29D of the air conditioner main body 29. The inside / outside air switching device 65 is disposed behind the driver's seat 6. The inside / outside air switching device 65 switches between a state in which outside air is introduced into the air conditioner main body 29 and a state in which inside air is introduced.

[0066] As shown in FIG. 9, the inside / outside air switching device 65 has a housing 65a and a switching damper 65b arranged inside the housing 65a. The housing 65a has an inside air intake 65c and an outside air intake 65d. The inside air intake 65c opens facing upward. The outside air intake 65d opens facing rearward. The switching damper 65b can be swung around the support shaft 52e as shown by the arrow Y3. The switching damper 65b can be swung between a first position (position shown by a solid line) where the inside air intake 65c is opened and the outside air intake 65d is closed, and a second position (position shown by a virtual line) where the outside air intake 65d is opened and the inside air intake 65c is closed. The operation of switching (swinging) the switching damper 65b between the first position and the second position can be performed by a changeover switch (not shown) provided near the driver's seat 6.

[0067] When the switching damper 65b is in the first position, air inside the cabin 5 (inside air) is taken into the housing 65a through the inside air intake 65c and supplied to the air conditioner main body 29. When the switching damper 65b is in the second position, air outside the cabin 5 (outside air) is taken into the housing 65a through the outside air intake 65d and supplied to the air conditioner main body 29. The air taken in through the outside air intake 65d is air taken in through the outside air inlet 34 (outside air).

[0068] As shown in Figures 9 and 10, an outside air duct 66 is connected to the outside air intake 65d of the inside / outside air switching device 65. The outside air duct 66 is a duct for guiding outside air to the outside air intake 65d. The outside air duct 66 extends in the front-rear direction, and its front part is connected to the outside air intake 65d. The outside air duct 66 extends rearward from the outside air intake 65d, and its width (length in the fuselage width direction) increases toward the rear.

[0069] As shown in FIG. 17, the outside air duct 66 is attached to an opening 5c ​​provided on the rear surface 5b of the cabin 5. A bulging portion 5d is provided on the rear surface 5b of the cabin 5, bulging toward the rear so as to expand the internal space at the rear of the cabin 5, and an opening 5c ​​is formed in the bulging portion 5d. The opening 5c ​​is connected to the internal space of the cabin 5. The outside air duct 66 has a flange 66a. The bulging portion 5d and the flange 66a are fixed to each other with a fastener such as a bolt, so that the outside air duct 66 is fixed to the bulging portion 5d (see FIG. 18). With the outside air duct 66 fixed to the bulging portion 5d, the front portion of the outside air duct 66 is inserted into the cabin 5 through the opening 5c ​​(see FIG. 9).

[0070] 10 and 19, a first filter 71 and a second filter 72 are attached to the outside air duct 66. The first filter 71 and the second filter 72 are attached to the rear part of the outside air duct 66. 19, the first filter 71 has a filter body 71A and a holding portion 71B that holds the filter body 71A. The filter body 71A is disposed at a position overlapping the second filter 72 in a rear view. The holding portion 71B has an outer peripheral portion 71B1 provided around the filter body 71A and a rear extension portion 71B2 that extends rearward from the outer peripheral portion 71B1. The rear extension portion 71B2 is formed in a rectangular tube shape and is fitted into an opening 66b at the rear of the outside air duct 66.

[0071] The first filter 71 and the second filter 72 are fixed to the rear of the outside air duct 66 by the frame body 73. In other words, the frame body 73 fixes the second filter 72 and the first filter 71 to the outside air duct 66. The frame body 73 fixes the second filter 72 to the outside air duct 66 by overlapping it with the first filter 71. As shown in FIG. 18 , the second filter 72 is exposed from an opening of the frame body 73 while being fixed by the frame body 73.

[0072] 19, frame body 73 has a locking portion 73a and a fixing portion 73b. Locking portion 73a is provided on the right portion of frame body 73. Locking portion 73a is a portion that is locked to outside air duct 66. A locking hole 66c is provided on the right rear portion of outside air duct 66. By inserting locking portion 73a into locking hole 66c, locking portion 73a is locked to locking hole 66c.

[0073] The fixing portion 73b is provided on the left side of the frame 73. The fixing portion 73b is a portion that is fixed to the outside air duct 66. A through hole 73c is provided in the fixing portion 73b. A fixed portion 66d is provided on the left rear portion of the outside air duct 66. A screw hole 66e is provided in the fixed portion 66d. The fixing portion 73b is fixed to the fixed portion 66d by overlapping the through hole 73c with the screw hole 66e and inserting the knob bolt 74 through the through hole 73c and screwing it into the screw hole 66e.

[0074] With the first filter 71 and the second filter 72 overlapped in the front-to-rear direction, the locking portion 73a of the frame body 73 is locked into the locking hole 66c of the outside air duct 66, and the knob bolt 74 is tightened to fix the fixing portion 73b of the frame body 73 to the fixed portion 66d of the outside air duct 66, thereby fixing the frame body 73 together with the first filter 71 and the second filter 72 to the outside air duct 66. When the knob bolt 74 is removed to release the fixing of the fixing portion 73b to the fixed portion 66d, the frame body 73 can be removed from the outside air duct 66, and the first filter 71 and the second filter 72 can be removed.

[0075] As shown in Fig. 10 and other figures, the first filter 71 and the second filter 72 are arranged side by side in the front-rear direction. The first filter 71 and the second filter 72 are arranged in a position overlapping with the outside air inlet 34 (see Fig. 7 and other figures) in rear view. As shown in Figs. 10 and 19, the first filter 71 is attached to the rear of the outside air duct 66. The second filter 72 is arranged between the outside air inlet 34 and the first filter 71 in the front-rear direction. In other words, the second filter 72 is arranged in a position closer to the outside air inlet 34 than the first filter 71.

[0076] The first filter 71 and the second filter 72 remove foreign matter contained in the outside air taken in through the outside air inlet 34. Specifically, the second filter 72 first removes foreign matter contained in the outside air taken in through the outside air inlet 34, and then the first filter 71 removes foreign matter contained in the outside air that has passed through the second filter 72. The second filter 72 is a filter with coarser mesh than the first filter 71. In other words, the first filter 71 is a filter with finer mesh than the second filter 72. That is, the first filter 71 is a high-precision filter that can remove finer foreign matter than the second filter 72. By disposing the second filter 72 in a position closer to the outside air inlet 34 than the first filter 71, clogging of the first filter 71, which has finer mesh, is less likely to occur, and the life of the first filter 71 can be extended.

[0077] As shown by arrow Y4 in Figure 10, the outside air taken in through the outside air inlet 34 and passing through the first filter 71 and the second filter 72 is taken into the outside air intake 65d of the inside / outside air switching device 65 by the outside air duct 66 and is guided to the air conditioner main body 29. As shown in Figures 1, 2, 5, 6, and 7, a rear cover 77 is attached to the rear surface 5b of the cabin 5, protruding rearward from the rear surface 5b. The outside air inlet 34 is provided in the rear cover 77. The rear cover 77 is located at a lower part of the rear surface 5b of the cabin 5 (below the rear window 5e). The rear cover 77 is detachably attached to the rear surface 5b of the cabin 5.

[0078] As shown in FIG. 20, the rear cover 77 has a first mounting portion 77a, a second mounting portion 77b, and a third mounting portion 77c. The first mounting portion 77a is provided with a first mounting hole 77d. The second mounting portion 77b is provided with a second mounting hole 77e. The third mounting portion 77c is provided with a third mounting hole 77f. As shown in FIG. 18, a first bracket 78, a second bracket 79, and a third bracket 80 are attached to the lower part of the rear surface 5b of the cabin 5. The first bracket 78 is provided with a first mounting hole 78a. The second bracket 79 is provided with a second mounting hole 79a. The third bracket 80 is provided with a third mounting hole 80a. The rear cover 77 is attached to the rear surface 5b of the cabin 5 by overlapping the first mounting hole 77d with the first mounting hole 78a, the second mounting hole 77e with the second mounting hole 79a, and the third mounting hole 77f with the third mounting hole 80a, respectively, and fastening them with bolts and nuts.

[0079] As shown in FIG. 1, FIG. 5, FIG. 6, FIG. 7, etc., the rear cover 77 is disposed above the sixth cover 43F. As shown in FIG. 1, the position of the rear cover 77 in the vertical direction overlaps with the driver's seat 6. The upper end of the rear cover 77 is located lower than the upper end of the driver's seat 6. The lower end of the rear cover 77 is located higher than the lower end of the driver's seat 6. As shown in FIG. 2, the position of the rear cover 77 in the vehicle width direction overlaps with the driver's seat 6. The right end of the rear cover 77 is located to the left of the right end of the driver's seat 6. The left end of the rear cover 77 is located to the left of the left end of the driver's seat 6 or at approximately the same position as the left end of the driver's seat 6. The width (length in the vehicle width direction) of the rear cover 77 is longer than the width (length in the vehicle width direction) of the driver's seat 6.

[0080] The rear cover 77 covers the rear of the air conditioner main body 29 inside the cabin 5. The front of the air conditioner main body 29 is disposed inside the cabin 5. The rear of the air conditioner main body 29 is disposed protruding rearward from the cabin 5. The rear cover 77 covers the rear of the air conditioner main body 29 protruding rearward from the cabin 5. However, the rear of the air conditioner main body 29 does not have to protrude rearward from the cabin 5. In other words, the entire air conditioner main body 29 may be disposed inside the cabin 5 (in front of the rear cover 77). At least the first filter 71, the second filter 72, and the outside air duct 66 are disposed inside the rear cover 77 (see FIG. 10). As shown in Figs. 1, 2, 5, 6, 7, and 10, the rear cover 77 has a lid body 81. The lid body 81 has a rectangular shape in which the length in the width direction of the machine body is longer than the length in the up-down direction when viewed from the rear. As shown in Figs. 20 and 21, a rear opening 77g is formed in the rear cover 77, and the lid body 81 is attached so as to cover the rear opening 77g. The lid body 81 can be opened and closed with respect to the rear cover 77 (see arrow Y5 in Fig. 2). When the lid body 81 is opened, the second filter 72 and the frame body 73 are exposed from the rear opening 77g (see Fig. 21). This allows the frame body 73 to be removed from the outside air duct 66 to perform replacement of the first filter 71 and the second filter 72, etc.

[0081] As shown in Fig. 23, a hinge 82 is attached to the right end of the lid 81. This hinge 82 is attached to the right edge of the rear opening 77g of the rear cover 77 (see Figs. 20 and 21). This allows the lid 81 to be opened toward the right rear with the hinge 82 as a fulcrum (see arrow Y5 in Fig. 2). A keyhole 81b is provided on the left side of the lid 81. By inserting a key into the keyhole 81b and turning it (locking), the lid 81 can be made unopenable.

[0082] As shown in Fig. 21, the rear cover 77 is provided with a cushion member 83 near the left edge of the rear opening 77g. The cushion member 83 is made of an elastic material such as rubber. The cushion member 83 is disposed in a position facing the rear opening 77g. When the lid body 81 is closed, the cushion member 83 comes into contact with the front surface of the lid body 81 and elastically deforms. This makes it possible to prevent the lid body 81 from rattling when closed.

[0083] As shown in Figures 5, 6, 7, 22, etc., the cover 81 is provided with an outside air inlet 34. The outside air inlet 34 is an opening for taking in air outside the cabin 5 (outside air) into the cabin 5. The outside air is taken in from the outside air inlet 34 by driving the blower fan 29D of the air conditioner main body 29. A plurality of outside air inlets 34 (ten in the illustrated example) are provided. In the present embodiment, the outside air inlets 34 are elongated holes whose length in the width direction of the body is longer than their length in the up-down direction. As shown in FIG. 22, an area 81R is provided in the upper part of the lid body 81 where no outside air inlets 34 are provided. In other words, no outside air inlets 34 are provided in the area 81R in the upper part of the lid body 81.

[0084] 22, a first rib 84A and a second rib 84B are provided on the front surface of the lid body 81. The first rib 84A is provided on the right side of the front surface of the lid body 81. The second rib 84B is provided on the left side of the front surface of the lid body 81. The first rib 84A and the second rib 84B extend parallel to each other in the vertical direction. As shown in Fig. 23, a case 85 is attached to the front portion (front face) of the cover 81. As shown in Fig. 24, a net body 86 is housed in the case 85. The net body 86 is an insect catching net body for capturing insects and the like that enter through the outside air inlet 34. The net body 86 has coarser mesh than the second filter 72.

[0085] As shown in FIG. 25 and other figures, the case 85 has a front plate 85a and a peripheral wall 85b. The front plate 85a has a rectangular shape in which the length in the width direction of the body is longer than the length in the up-down direction when viewed from the rear. As shown in FIG. 23, FIG. 24, FIG. 25 and other figures, the front plate 85a has an opening 85c. A plurality of openings 85c (16 in the illustrated example) are provided. In the case of this embodiment, the openings 85c are elongated holes whose length in the up-down direction is longer than the length in the width direction of the body. The openings 85c allow the passage of outside air taken in from the outside air inlet 34. A region 85R in which the openings 85c are not provided is provided in the lower part of the front plate 85a. In other words, the openings 85c are not provided in the region 85R in the lower part of the front plate 85a.

[0086] 22, the front plate 85a is disposed so as to face the outside air inlet 34. A mesh body 86 is disposed behind the front plate 85a. The peripheral wall 85b extends rearward from the outer edge of the front plate 85a. The peripheral wall 85b is provided with an attachment portion 85d. A bolt BL1 is inserted into the attachment portion 85d and screwed into an attachment portion 81a provided on the front surface of the lid body 81, whereby the case 85 is attached to the front portion of the lid body 81.

[0087] As shown in Fig. 26, when the case 85 is attached to the front of the lid 81, a space SP1 is formed between the front plate 85a and the lid 81. A mesh body 86 can be housed in this space SP1. When housed in the space SP1, the mesh body 86 is disposed between the first rib 84A and the second rib 84B (see Fig. 23). 26, the net body 86 is disposed in the vicinity of the lid body 81 so as to face the outside air inlet 34 of the lid body 81. Therefore, the net body 86 is located closer to the outside air inlet 34 than the second filter 72 (see FIG. 10), which is disposed at a position away from the lid body 81. In other words, the net body 86 is disposed between the outside air inlet 34 and the second filter 72 while being accommodated in the space SP1. This allows insects and the like that have entered through the outside air inlet 34 to be captured by the net body 86 before they reach the second filter 72.

[0088] As shown in FIG. 26, in a state where the case 85 is attached to the front of the lid 81, the opening 85c is provided at a position higher than the outside air inlet 34. That is, the height H1 of the lower end of the opening 85c is higher than the height H2 of the upper end of the outside air inlet 34. In other words, the outside air inlet 34 is disposed opposite the area 85R where the opening 85c is not provided. Also, the opening 85c is disposed opposite the area 81R where the outside air inlet 34 is not provided. As a result, when the working machine 1 is washed with water, the washing water that has entered from the outside air inlet 34 hits the area 85R and flows down, so that it is possible to prevent the water from entering the opening 85c (see the arrow Y6 in FIG. 26). The washing water that hits the area 85R and flows down passes through the gap GP2 between the front plate 85a and the net body 86 and the gap GP3 between the lid 81 and the rear cover 77 to the outside of the machine body 2. On the other hand, the outside air taken in through the outside air inlet 34 can rise and enter the opening 85c (see arrow Y7 in FIG. 26).

[0089] As shown in FIG. 25, the peripheral wall 85b of the case 85 extends rearward from the lower edge, left edge, and right edge of the outer edge of the front plate 85a. In other words, the peripheral wall 85b is not provided on the upper edge of the front plate 85a. As a result, when the case 85 is attached to the front part of the lid body 81, a wide gap GP1 is formed between the case 85 and the lid body 81 at the upper part of the case 85 (see FIGS. 24 and 26). Therefore, the net body 86 can be accommodated in the case 85 from above the case 85 through this gap GP1 (see arrow Y8 in FIG. 24). In addition, the net body 86 can be taken out of the case 85 from above the case 85 through this gap GP1. When the net body 86 is put in or taken out of the case 85, the first rib 84A and the second rib 84B function as guides to guide the movement of the net body 86.

[0090] As shown in Figures 22 and 24, a holding frame 87 that holds the net body 86 is provided around the net body 86. The holding frame 87 is formed in a square ring shape. A fixing portion 87a is provided at the upper part of the holding frame 87 to fix the holding frame 87 together with the net body 86 to the case 85. The fixing portion 87a extends forward from the upper part of the holding frame 87 and then bends and extends downward. A through hole 87b is formed in the fixing portion 87a.

[0091] As shown in FIG. 22 and FIG. 24, a fixed portion 85e is provided on the front surface of the front plate 85a of the case 85. The fixed portion 85e is a portion to which the fixing portion 87a is fixed. The fixed portion 85e protrudes forward from the upper portion of the front plate 85a. A screw hole 85f is formed in the fixed portion 85e. With the mesh body 86 housed in the case 85, the holding frame 87 can be fixed to the case 85 by inserting a wing bolt 88 into the through hole 87b of the fixing portion 87a and screwing the wing bolt 88 into the screw hole 85f of the fixing portion 85e. This positions and fixes the mesh body 86 to the case 85. Also, by removing the wing bolt 88 from the screw hole 85f, the holding frame 87 is released from the fixing of the case 85. This makes it possible to take out the holding frame 87 together with the mesh body 86 from the case 85.

[0092] As shown in Fig. 25, the case 85 has a protruding portion 85g protruding rearward (toward the outside air inlet 34) from the front plate 85a. The protruding portion 85g includes a first protruding portion 85g1 provided on the left side of the front plate 85a and a second protruding portion 85g2 provided on the right side of the front plate 85a. The first protruding portion 85g1 and the second protruding portion 85g2 extend parallel to each other in the vertical direction. The protruding length of the protruding portion 85g increases from the top to the bottom.

[0093] 26, when the case 85 is attached to the front of the lid 81, the protrusion 85g comes into contact with the front surface of the mesh body 86. As a result, the mesh body 86 is pushed toward the lid 81 by the protrusion 85g and comes into contact with or close to the outside air inlet 34. Here, since the protrusion length of the protrusion 85g increases from the top to the bottom, the protrusion 85g can be reliably brought into contact with the front surface of the mesh body 86. In addition, since the protrusion length of the protrusion 85g is short at the top, the task of housing the mesh body 86 in the case 85 from above can be easily performed.

[0094] The work machine 1 is provided with a holding section 90 for holding the lid body 81 in an open state. The holding section 90 is composed of a holding member 91 (see Figures 20, 21, and 26) provided on the rear cover 77 and a holding mechanism 92 (see Figures 22, 23, 26, etc.) provided on the case 85. As shown in Figs. 20 and 21, the holding member 91 is provided on the periphery of the rear opening 77g of the rear cover 77. Specifically, the holding member 91 is provided so as to protrude from the right part of the periphery of the rear opening 77g of the rear cover 77 to the left (the rear opening 77g side). The holding member 91 is provided between two hinges 82 arranged side by side in the vertical direction. The holding member 91 is flat, with one surface facing upward and the other surface facing downward. The holding member 91 has a through hole 91a formed therein, which passes through the holding member 91 in the vertical direction.

[0095] As shown in FIG. 22 and FIG. 23, the holding mechanism 92 is provided on the front surface of the front plate 85a of the case 85. The holding mechanism 92 has a support portion 93, a stay 94, and an engagement portion 95. The support portion 93 protrudes forward from the front surface of the front plate 85a. The support portion 93 has a through hole 93a extending in the vertical direction. The support portion 93 supports the stay 94 rotatably around the axis Z1 in the vertical direction. The stay 94 has a first portion 94a, a second portion 94b, and a third portion 94c. The first portion 94a extends in the vertical direction and is inserted from above into the through hole 93a formed in the support portion 93. The second portion 94b is bent from the upper end of the first portion 94a and extends in the horizontal direction. The third portion 94c is bent from the second portion 94b and extends downward. The third portion 94c is. The first portion 94a is disposed parallel to the first portion 94a with a gap therebetween.

[0096] The engaging portion 95 is provided on the front surface of the front plate 85a, and can engage with the second portion 94b of the stay 94. The engaging portion 95 is formed by bending a metal plate having spring properties. The engaging portion 95 can detachably hold the second portion 94b by the spring properties of the metal plate. The second portion 94b is sandwiched and held by the metal plates from above and below. The second portion 94b can be engaged with the engaging portion 95 by rotating the stay 94 in one direction (arrow Y9 direction in FIG. 23) about the axis Z1. The second portion 94b can be disengaged from the engaging portion 95 by rotating the stay 94 in the other direction (arrow Y10 direction in FIG. 23) about the axis Z1. When the second portion 94b is disengaged from the engaging portion 95, the stay 94 can be moved within a predetermined range in the vertical direction along the through hole 93a.

[0097] When the lid body 81 is closed, the second part 94b of the stay 94 is engaged with the engagement part 95 (see Figs. 23 and 27). When it is desired to hold the lid body 81 in the open state after opening it, the stay 94 is rotated in the other direction (the direction of the arrow Y10 in Fig. 23, the direction of the arrow Y11 in Fig. 28) around the axis Z1 to disengage the second part 94b from the engagement part 95, and the third part 94c is inserted into the through hole 91a of the holding member 91 from above (see Fig. 28). As a result, the movement of the lid body 81 is restricted by the stay 94, so that the lid body 81 cannot be closed and the open state of the lid body 81 is maintained. As a result, when maintenance (such as replacing a filter) is being performed with the lid body 81 in the open state, it is possible to prevent the lid body 81 from closing unintentionally, improving maintainability.

[0098] As described above, the work machine 1 has a filter structure including the mesh body 86, the first filter 71, and the second filter 72 in order to remove foreign matter from the outside air introduced from the outside air inlet 34. The outside air introduced into the rear cover 77 from the outside air inlet 34 passes through the mesh body 86, the second filter 72, and the first filter 71 in this order. This removes foreign matter from the outside air. The outside air from which the foreign matter has been removed is supplied to the air conditioner main body 29 from the inside / outside air switching device 65. The air conditioner main body 29 generates conditioned air, and the generated conditioned air is blown out into the duct structure 50 described above.

[0099] Next, the connection structure of the duct structure 50 will be described. As described above, the duct structure 50 is made up of the relay duct 51, the switching box 52, the first duct 53, the second duct 54, the third duct 55, and the fourth duct 56 (see FIGS. 12 and 13). In other words, the duct structure 50 is configured by connecting a plurality of ducts (including the switching boxes 52). Therefore, the duct structure 50 includes one duct and the other duct that are connected to each other.

[0100] Specifically, the duct structure 50 includes a relay duct (one duct) 51 and a switching box (the other duct) 52 that are connected to each other. The duct structure 50 also includes a switching box (one duct) 52 and a first duct (the other duct) 53 that are connected to each other. The duct structure 50 also includes a switching box (one duct) 52 and a second duct (the other duct) 54 that are connected to each other. The duct structure 50 also includes a first duct (one duct) 53 and a third duct (the other duct) 55 that are connected to each other. The duct structure 50 also includes a second duct (one duct) 54 and a fourth duct (the other duct) 56 that are connected to each other.

[0101] 29 and 30 show a case where one duct 50A is the first duct 53 and the other duct 50B is the third duct 55. One duct 50A (first duct 53) has a first connection part 96 that is inserted into and connected to the other duct 50B (third duct 55). The other duct 50B (third duct 55) has a second connection part 97 that is inserted into and connected to the one duct 50A (first duct 53).

[0102] The first connection portion 96 has a first end surface 96a perpendicular to the insertion direction D1 of the one duct 50A (the first duct 53). The first connection portion 96 also has a cylindrical portion 96c extending from an inner end portion 96b of the first end surface 96a toward the other duct 50B (the third duct 55). The first end surface 96a is a surface extending inward (toward the central axis of the duct 50A) from an outer peripheral surface 96d of the one duct 50A (the first duct 53). The first end surface 96a is a flat surface having an annular (quadrangleous) shape. The first end surface 96a is provided so as to surround the outer periphery of the cylindrical portion 96c.

[0103] A protrusion 96e is formed on the outer surface of the cylindrical portion 96c. The protrusion 96e protrudes outward (away from the central axis of the duct 50A) from an outer surface 96f of the cylindrical portion 96c. The protrusion 96e extends long in a direction perpendicular to the insertion direction D1. In other words, the protrusion 96e is a protrusion extending in the circumferential direction of the cylindrical portion 96c. The protrusion 96e may be formed over the entire circumference of the cylindrical portion 96c, or may be formed only on a part of the entire circumference of the cylindrical portion 96c. In the case of this embodiment, the protrusion 96e is formed on each of the four outer surfaces 96f constituting the rectangular cylindrical portion 96c. The protrusion 96e protrudes in an arc shape from the outer surface 96f of the cylindrical portion 96c. A recess 96h recessed toward the outer surface side is formed on the inner surface 96g of the cylindrical portion 96c at a position corresponding to the protrusion 96e.

[0104] As shown in Fig. 30, the second connection portion 97 has a second end face 97a facing the first end face 96a. The second end face 97a is also a surface perpendicular to the insertion direction D1. The second end face 97a is a surface parallel to the first end face 96a. As shown in Figs. 29 and 30, the second end face 97a is a surface extending inward (toward the central axis of the duct 50B) from the outer peripheral surface 97b of the other duct 50B (the third duct 55). The second end face 97a is a ring-shaped (quadrangle-shaped) flat surface.

[0105] The second connection portion 97 has a folded portion 97d folded back from an inner end portion 97c of the second end surface 97a toward the opposite side to the first end surface 96a side (the opposite side to the insertion direction D1). The folded portion 97d may be formed around the entire circumference of the inner end portion 97c of the second end surface 97a, or may be formed around only a part of the entire circumference of the inner end portion 97c of the second end surface 97a. In this embodiment, the folded portion 97d is formed around the entire circumference of the inner end portion 97c of the second end surface 97a.

[0106] In a state where one duct 50A (first duct 53) is inserted into the other duct 50B (third duct 55) and connected, the cylindrical portion 96c of the first connection portion 96 is inserted into the inside of the other duct 50B (third duct 55) (see FIG. 30). In this state, the inner surface 97e of the folded portion 97d is located inside (closer to the center of the cylindrical portion 96c) than the apex (the outermost part) of the protrusion 96e. In addition, the end portion 97f of the folded portion 97d on the front side in the insertion direction D1 is located behind the protrusion 96e in the insertion direction D1. As a result, the folded portion 97d is engaged with the cylindrical portion 96c, and the other duct 50B (third duct 55) is less likely to fall off from the one duct 50A (first duct 53). In other words, the one duct 50A and the other duct 50B are connected to each other.

[0107] The first duct 50A and the second duct 50B can be made of a flexible synthetic resin. As a result, when the first duct 50A and the second duct 50B are attached to or detached from each other, the folded-back portion 97d is pushed by the protrusion 96e and bends outward (elastically deforms). Therefore, the first duct and the second duct can be easily attached to or detached from each other. When one duct 50A (first duct 53) is inserted into the other duct 50B (third duct 55) and connected, the folded-back portion 97d comes into contact with or is close to an outer surface 96f of the cylindrical portion 96c (more specifically, a portion of the outer surface 96f that is further rearward in the insertion direction D1 than the protrusion 96e) (see FIG. 30). This makes it possible to eliminate or reduce rattling at the connection portion between the one duct 50A and the other duct 50B.

[0108] As described above, since the second connection portion 97 of the other duct 50B has the folded portion 97d, when the other duct 50B is manufactured by blow molding, the inner peripheral surface of the second connection portion 97 (the inner surface 97e of the folded portion 97d) can be manufactured with high precision. This point will be described below with reference to FIG. As shown in Fig. 31, when the other duct 50B is manufactured by blow molding, first, resin heated by an extruder is made into a container shape called a parison and inflated in a mold N1 to fit the shape of the mold (see the left diagram in Fig. 31). After that, unnecessary parts are cut off with a cutter (the cut parts are shown by arrows CT in Fig. 31), and the other duct equipped with a second connection part 97 having a folded part 97d is completed. The second connection part 97 of the other duct 50B manufactured in this way has an inner peripheral surface (an inner surface 97e of the folded part 97d) molded by the surface of the mold N1, so that the dimensional accuracy of the inner peripheral surface is very high. Therefore, no rattling occurs when it is connected to one of the ducts.

[0109] If the other duct is manufactured by blow molding in a shape that does not have the folded-back portion 97d as in the conventional case, the inner peripheral surface of the connecting portion is formed by a cut surface (a surface cut manually), which results in low dimensional accuracy of the inner peripheral surface of the connecting portion, causing rattling when connected to the other duct. 30, a cushioning material 99 is interposed between the first end surface 96a and the second end surface 97a. The cushioning material 99 is made of an elastic body such as rubber. For example, the cushioning material 99 may be made of EPDM (ethylene propylene diene rubber) as a base material.

[0110] The cushion material 99 is adhered to the first end surface 96a or the second end surface 97a. In the present embodiment, the cushion material 99 is adhered to the first end surface 96a. However, the cushion material 99 may be adhered to the second end surface 97a. As shown in FIG. 29, the cushion material 99 is an annular (quadratic annular) member. The cushion material 99 is disposed so as to surround the outer periphery of the tubular portion 96c.

[0111] In a state where one duct 50A (first duct 53) is inserted into the other duct 50B (third duct 55) and connected, the cushion material 99 is sandwiched and disposed between the first end face 96a and the second end face 97a. In this state, the cushion material 99 abuts against the first end face 96a and the second end face 97a. In this state, the cushion material 99 may abut against the first end face 96a, the second end face 97a, and the outer surface of the cylindrical portion 96c.

[0112] According to the above-mentioned duct connection structure, the cushioning material 99 is interposed between the first end face 96a perpendicular to the insertion direction D1 and the second end face 97a opposite to the first end face 96a, so that when one duct 50A and the other duct 50B are attached or detached, the inner surface of the duct does not rub against the outer surface of the cushioning material 99. This makes it possible to prevent the cushioning material 99 from peeling off when one duct 50A and the other duct 50B are attached or detached.

[0113] In the case of a conventional duct connection structure (for example, the connection structure disclosed in the above-mentioned Patent Document 1), when one duct is attached to the other duct, the inner surface of the duct rubs against the outer surface of the cushion material 99. Therefore, if a cushion material 99 made of a highly adhesive material (for example, EPDM) is used, the cushion material 99 will stick to the duct and peel off when one duct is attached to the other duct. Therefore, it is necessary to use a cushion material made of a material with low adhesiveness, and there is a risk that sufficient sealing properties cannot be obtained at the connection portion. However, according to the above-mentioned duct connection structure, when the ducts are attached to each other, the inner surface of the duct does not rub against the outer surface of the cushion material 99, so that a cushion material made of a highly adhesive material (for example, EPDM) can be used, and the sealing properties of the connection portion can be improved.

[0114] The above-mentioned duct connection structure (the connection structure between one duct 50A and the other duct 50B) can also be applied to the case where one duct 50A is a relay duct 51 and the other duct 50B is a switching box 52. That is, as shown in Fig. 14, it can also be applied to the connection structure between a relay duct 51 and a switching box 52. The above-described duct connection structure can also be applied to the case where one duct 50A is a switching box 52 and the other duct 50B is a first duct 53. That is, as shown in Fig. 14, it can also be applied to the connection structure between the switching box 52 and the first duct 53.

[0115] The above-mentioned duct connection structure can also be applied to the case where one duct 50A is a switching box 52 and the other duct 50B is a second duct 54. That is, as shown in Fig. 14, it can also be applied to the connection structure between the switching box 52 and the second duct 54. The above-mentioned duct connection structure can also be applied to the case where one duct 50A is the second duct 54 and the other duct 50B is the fourth duct 56. That is, as shown in Fig. 32, it can also be applied to the connection structure between the second duct 54 and the fourth duct 56.

[0116] The above-mentioned work machine 1 comprises a body 2, a cabin 5 mounted on the body 2, a driver's seat 6 arranged inside the cabin 5, and an air conditioner main body 29 that generates conditioned air to be supplied inside the cabin 5, and an outside air inlet 34 is provided on the rear surface 5b side of the cabin 5 to take in outside air to be introduced into the air conditioner main body 29. According to this configuration, the outside air inlet 34 is provided on the back side of the cabin 5 where a larger space can be secured compared to the side sides of the cabin 5. Therefore, it is possible to enlarge the filter for removing foreign matter in the air taken in from the outside air inlet 34. This makes it possible to arrange a high-performance filter (for example, Category 2 of the EN standard, MARV-16 of the OSHA standard, etc.) (first filter 71) as the filter. It is also possible to arrange another filter (second filter 72, net body 86, etc.) in addition to the first filter 71. Furthermore, since the filter can be enlarged, it is possible to increase the amount of introduced outside air passing through the filter.

[0117] In addition, the air conditioner main body 29 is disposed behind the driver's seat 6. According to this configuration, it is possible to shorten the duct (duct structure 50) that guides the outside air introduced from the outside air inlet 34 to the air conditioner main body 29. As a result, the outside air introduced from the outside air inlet 34 can be supplied to the air conditioner main body 29 over a short distance. Therefore, it is possible to reduce the installation space inside the cabin 5 for the duct that guides the outside air introduced from the outside air inlet 34 to the air conditioner main body 29. In addition, since the duct can be shortened, it is possible to reliably draw in the outside air from the outside air inlet 34.

[0118] Further, a rear cover 77 is attached to the rear surface 5b of the cabin 5, protruding rearward from the rear surface 5b, and the outside air inlet 34 is provided in the rear cover 77. According to this configuration, the rear cover 77 can ensure a large space behind the driver's seat 6 in which the air conditioner main body 29 and the like can be installed. Therefore, a space behind the driver's seat 6 in which the air conditioner main body 29 and the like can be installed can be ensured without increasing the size of the cabin 5 itself.

[0119] Further, the rear cover 77 has a lid body 81 that can be opened and closed, and the outside air inlet 34 is provided in the lid body 81 . According to this configuration, by opening the cover 81, maintenance such as replacement of the filter through which the outside air introduced from the outside air inlet 34 passes can be easily performed. The work machine 1 also includes a first filter 71 that removes foreign matter contained in the outside air taken in through the outside air inlet 34, and an outside air duct 66 that guides the outside air that has passed through the first filter 71 toward the air conditioner main body 29, and the first filter 71 is attached to the outside air duct 66.

[0120] According to this configuration, when the outside air taken in through the outside air inlet 34 is guided through the outside air duct 66 to the air conditioner main body 29, foreign matter contained in the outside air can be reliably removed by the first filter 71. The work machine 1 also includes a second filter 72 which has a coarser mesh than the first filter 71 and is positioned between the outside air inlet 34 and the first filter 71, and a frame 73 which fixes the second filter 72 and the first filter 71 to the outside air duct 66.

[0121] According to this configuration, the outside air taken in through the outside air inlet 34 can be passed through the second filter 72 and then supplied to the first filter 71, making it difficult for the first filter 71 to become clogged and extending the life of the first filter 71. In addition, the first filter 71 and the second filter 72 can be released from their fixed position by removing the frame 73, making it easy to replace the first filter 71 and the second filter 72.

[0122] The work machine 1 also includes a net 86 for catching insects, which is disposed between the outside air inlet 34 and the second filter 72. According to this configuration, insects and the like that have invaded through the outside air inlet 34 can be captured by the net body 86. Therefore, it is possible to prevent the second filter 72 from becoming clogged with insects and the like that have invaded through the outside air inlet 34, and it is possible to extend the life of the second filter 72.

[0123] A case 85 for accommodating a mesh body 86 in a removable manner is attached to the front of the lid body 81. According to this configuration, the net body 86 can be easily attached, and the trapped insects and the like can be removed by removing the net body 86 from the case 85. This makes it possible to prevent the net body 86 from becoming clogged.

[0124] In addition, the case 85 has a front plate 85a arranged in front of the mesh body 86 facing the outside air inlet 34, and the front plate 85a has an opening 85c that allows the passage of outside air taken in from the outside air inlet 34, and the opening 85c is located at a higher position than the outside air inlet 34. According to this configuration, when the work machine 1 is washed with water, washing water that has entered through the outside air inlet 34 can be prevented from entering the opening 85c.

[0125] Furthermore, the case 85 has a protruding portion 85g that protrudes from the front plate 85a towards the outside air inlet 34 and abuts against the front surface of the mesh body 86, and the protruding length of the protruding portion 85g increases from the top to the bottom. According to this configuration, when the case 85 is attached to the front of the lid 81, the protruding portion 85g can press the mesh body 86 toward the lid 81. This allows the mesh body 86 to be disposed in contact with or close to the outside air inlet 34. Furthermore, since the protruding length of the protruding portion 85g increases from the top to the bottom, at least the lower portion of the protruding portion 85g can be reliably brought into contact with the mesh body 86. Furthermore, since the protruding length of the protruding portion 85g is short at the top, the task of housing the mesh body 86 in the case 85 from above can be easily performed.

[0126] The work machine 1 also includes a body 2, a cabin 5 mounted on the body 2, a driver's seat 6 arranged inside the cabin 5, an air conditioner main body 29 that generates conditioned air to be supplied to the inside of the cabin 5, and a duct structure 50 that guides the conditioned air supplied from the air conditioner main body 29. The air conditioner main body 29 generates conditioned air for cooling or heating by mixing cold air and hot air. The duct structure 50 includes a first duct 53 that circulates the conditioned air for cooling, a second duct 54 that circulates the conditioned air for heating, a switching box 52 that is connected to the first duct 53 and the second duct 54 and has a switching unit 52d that can switch between a first state in which the conditioned air supplied from the air conditioner main body 29 is circulated through the first duct 53 and a second state in which the conditioned air is circulated through the second duct 54, and a relay duct 51 that connects the air conditioner main body 29 and the switching box 52 and guides the conditioned air generated by the air conditioner main body 29 to the switching box 52.

[0127] According to this configuration, when the conditioned air generated by the air conditioner main body 29 is taken out in a state in which the cold air and the hot air are not sufficiently mixed, the cold air and the hot air can be sufficiently mixed in the relay duct 51 before being guided to the switching box 52. Therefore, the switching box 52 can be switched in a state in which the cold air and the hot air are sufficiently mixed. As a result, conditioned air for cooling or heating at an appropriate temperature in which the cold air and the hot air are sufficiently mixed can be guided from the switching box 52 to the first duct 53 or the second duct 54.

[0128] Further, the air conditioner main body 29 is disposed behind the driver's seat 6, and the duct structure 50 passes beside the driver's seat 6 and extends from behind the driver's seat 6 to in front of the driver's seat 6. According to this configuration, since the air conditioner main body 29 is disposed behind the driver's seat 6, the length from the air conditioner main body 29 to the switching box 52 can be increased. Therefore, the cold air and the hot air can be sufficiently mixed in the relay duct 51 before being guided to the switching box 52. Also, compared to the case where the air conditioner main body 29 and the duct structure 50 are disposed below the driver's seat 6, a larger space can be secured around the feet of the operator sitting in the driver's seat 6.

[0129] In addition, the work machine 1 is equipped with a steering device (right steering device 21) arranged to the side of the driver's seat 6, and the first duct 53 is arranged passing between the inner wall surface 5a of the cabin 5 on the side where the steering device (right steering device 21) is located and the steering device (right steering device 21). According to this configuration, the first duct 53 can be disposed in the front-rear direction passing near the side of the operator sitting in the driver's seat 6. Therefore, it becomes possible to blow out conditioned air for cooling from the first duct 53 near the operator sitting in the driver's seat 6 (for example, near the operator's face).

[0130] Further, the first duct 53 has a first outlet 53d, and the first outlet 53d includes a front outlet 53d1 that opens to the side of the driver's seat 6 and above the control device (right control device 21). According to this configuration, conditioned air for cooling can be blown out from the front outlet 53d1 near the face of the operator sitting in the driver's seat 6. Therefore, the operator can feel a strong sense of freshness. Conventionally, the first outlet 53d was provided near the display device 33 in front of the driver's seat 6, making it difficult to increase the size of the display device 33. However, by arranging the first outlet 53d at a position away from the display device 33, it is possible to increase the size of the display device 33.

[0131] The first air outlet 53d further includes a rear air outlet 53d2 that opens rearward of the driver's seat 6. According to this configuration, conditioned air for cooling can be blown out from the rear outlet 53d2 near the back of the head of the operator sitting in the driver's seat 6. Therefore, a strong feeling of coolness can be given to the operator.

[0132] In addition, the switching box 52 is disposed to the side of the driver's seat 6. According to this configuration, it is possible to blow out conditioned air of an appropriate temperature inside the switching box 52, in which cold air and hot air are sufficiently mixed, near the driver's seat 6. Furthermore, when the air conditioner main body 29 is disposed behind the driver's seat 6, the length from the air conditioner main body 29 to the switching box 52 can be increased. Therefore, the cold air and hot air can be sufficiently mixed in the relay duct 51 before being guided to the switching box 52.

[0133] Further, the duct structure 50 passes below the control device (right control device 21) and extends in the front-rear direction. According to this configuration, the duct structure 50 can be extended long in the front-rear direction at a position that does not interfere with the operator sitting in the driver's seat 6. In addition, the first duct 53 has a flat portion (third portion 53c) whose length in the aircraft width direction is shorter than its length in the front-to-rear direction, and the flat portion is arranged between the control device (right control device 21) and the inner wall surface 5a of the cabin 5.

[0134] According to this configuration, the flat portion (third portion 53c) of the first duct 53 can be disposed in the vicinity of the operator sitting in the driver's seat 6. Therefore, conditioned air for cooling (cold conditioned air) can be blown out near the face of the operator sitting in the driver's seat 6. In addition, by blowing out the cold conditioned air near the operator's face, the wind speed of the cold conditioned air hitting the vicinity of the operator's face can be increased.

[0135] Further, the flat portion (third portion 53c) has a front outlet 53d1 at its front portion and a rear outlet 53d2 at its rear portion. According to this configuration, conditioned air for cooling can be blown out from the front air outlet 53d1 near the face of the operator sitting in the driver's seat 6, and conditioned air for cooling can be blown out from the rear air outlet 53d2 near the back of the operator's head.

[0136] In addition, the first duct 53 has a main body portion (first portion 53a) that connects the switching box 52 and the third duct 55 arranged in front of the first duct 53, and a flat portion (third portion 53c) that rises upward from the main body portion along the inner wall surface 5a of the cabin 5, and the length of the flat portion in the width direction of the aircraft is shorter than the length of the main body portion in the width direction of the aircraft. According to this configuration, the conditioned air can be guided from the switching box 52 to the third duct 55 by one duct (the first duct 53), and the conditioned air can also be guided upward along the inner wall surface 5a of the cabin 5.

[0137] In addition, relay duct 51 is provided with flow passage expansion section 51f in which the flow passage cross-sectional area expands from the air conditioner main body 29 side toward the switching box 52 side. According to this configuration, the flow speed of the air flowing through relay duct 51 decreases as it moves from the air conditioner main body 29 side to the switching box 52 side, so that cool air and hot air can be reliably mixed within relay duct 51.

[0138] The work machine 1 also includes a body 2, a cabin 5 mounted on the body 2, an air conditioner main body 29 that generates conditioned air to be supplied to the inside of the cabin 5, and a duct structure 50 that guides the conditioned air supplied from the air conditioner main body 29, the duct structure 50 including one duct 50A and another duct 50B that are connected to each other, the one duct 50A having a first connection portion 96 that is inserted into and connected to the other duct 50B, the other duct 50B having a second connection portion 97 into which the one duct 50A is inserted and connected, the first connection portion 96 having a first end face 96a perpendicular to the insertion direction, the second connection portion 97 having a second end face 97a opposite to the first end face 96a, and a cushioning material 99 being interposed between the first end face 96a and the second end face 97a.

[0139] According to this configuration, the cushioning material 99 is interposed between the first end surface 96a perpendicular to the insertion direction and the second end surface 97a opposing the first end surface 96a, so that when one duct 50A and the other duct 50B are attached or detached, the ducts do not rub against the cushioning material 99. Therefore, it is possible to prevent the cushioning material 99 from peeling off when one duct 50A and the other duct 50B are attached or detached.

[0140] In addition, the first end face 96a is an annular surface extending inward from the outer peripheral surface of one duct 50A, the second end face 97a is an annular surface extending inward from the outer peripheral surface of the other duct 50B, and the cushion material 99 is an annular member abutting the first end face 96a and the second end face 97a. According to this configuration, the cushioning material 99 can be interposed between the first end surface 96a and the second end surface 97a around the entire circumference of the connection portion between the one duct 50A and the other duct 50B, resulting in excellent sealing properties of the connection portion.

[0141] The second connection portion 97 also has a folded-back portion 97d folded back from an inner end portion 97c of the second end face 97a toward the opposite side to the first end face 96a. According to this configuration, since the second connection portion 97 of the other duct 50B has the folded portion 97d, when the other duct 50B is manufactured by blow molding, the inner peripheral surface of the second connection portion 97 (the inner surface 97e of the folded portion 97d) can be manufactured with high dimensional accuracy. Therefore, the other duct 50B having the second connection portion 97 with high dimensional accuracy can be manufactured at low cost. In addition, the adhesion of the connection portion between the one duct 50A and the other duct 50B is improved.

[0142] In addition, the first connection portion 96 has a cylindrical portion 96c extending from an inner end portion 96b of the first end face 96a toward the other duct 50B, and a protrusion 96e is formed on the outer surface of the cylindrical portion 96c to engage with the folded portion 97d. According to this configuration, the folded portion 97d is formed on the projection 96e, so that the duct 50B on one side is less likely to fall off from the duct 50A on the other side.

[0143] Furthermore, the folded-back portion 97d comes into contact with the outer surface of the cylindrical portion 96c when the duct 50A on one side and the duct 50B on the other side are connected. According to this configuration, when one duct 50A and the other duct 50B are connected, the other duct 50B is less likely to fall off from the one duct 50A. Furthermore, the cushion material 99 comes into contact with the first end face 96a, the second end face 97a and the outer surface of the cylindrical portion 96c when the duct 50A on one side and the duct 50B on the other side are connected.

[0144] According to this configuration, when the duct 50A on one side and the duct 50B on the other side are connected, it is possible to improve the sealing performance of the connection portion between the duct 50A on one side and the duct 50B on the other side. The cushioning material 99 is adhered to the first end surface 96a or the second end surface 97a. According to this configuration, it is possible to more reliably prevent the cushion material 99 from falling off.

[0145] Although one embodiment of the present invention has been described above, the embodiment disclosed herein should be considered as illustrative and not restrictive in all respects. The scope of the present invention is indicated by the claims, not the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0146] 1 Work equipment 2. Aircraft 5 Cabin 5a Cabin inner wall 6 Driver's seat 21 Steering system (right steering system) 29 Air conditioner unit 50 Duct structure 52d Switching part 52 Switching Box 51 Relay duct 51f Enlarged flow passage 53 First Duct 53a Main body part (1st part) 53c Flat site (3rd site) 53d First air outlet 53d1 Front air outlet 53d2 Rear air outlet 54 Second Duct

Claims

1. The aircraft and A cabin mounted on the aircraft; A driver's seat disposed inside the cabin; an air conditioner main body that generates conditioned air to be supplied to the inside of the cabin; A duct structure for guiding conditioned air supplied from the air conditioner main body; A control device disposed on the side of the driver's seat; Equipped with The air conditioner main body mixes cold air and hot air to generate conditioned air for cooling or heating, The duct structure includes: A first duct for circulating conditioned air for cooling; A second duct for circulating conditioned air for heating; a switching box having a switching unit connected to the first duct and the second duct and capable of switching between a first state in which the conditioned air supplied from the air conditioner main body is caused to flow through the first duct and a second state in which the conditioned air is caused to flow through the second duct; A relay duct that connects the air conditioner main body and the switching box and guides the conditioned air generated by the air conditioner main body to the switching box; having The first duct has a flat portion whose length in a width direction of the aircraft body is shorter than its length in a front-rear direction, The flat portion is disposed between the control device and an inner wall surface of the cabin on a side where the control device is disposed, The flat portion is a work machine having a front outlet at a front portion that opens to the side of the driver's seat and above the control device, and a rear outlet at a rear portion that opens rearward of the driver's seat.

2. The air conditioner body is disposed behind the driver's seat, The work machine according to claim 1 , wherein the duct structure passes to the side of the driver's seat and extends from behind the driver's seat to ahead of the driver's seat.

3. A work machine as described in claim 1, wherein the switching box is arranged to the side of the driver's seat.

4. A work machine described in any one of claims 1 to 3, wherein the duct structure extends in the fore-and-aft direction passing beneath the control device.

5. The first duct comprises a main body portion arranged alongside the second duct in the fuselage width direction and connecting the switching box to a third duct arranged in front of the first duct, and the flat portion rising upward from the main body portion along the inner wall surface of the cabin, The work machine according to any one of claims 1 to 4, wherein the length of the flat portion in the width direction of the machine body is shorter than the length of the main body portion in the width direction of the machine body.

6. A work machine described in any one of claims 1 to 5, wherein the relay duct is provided with an expanded flow path section in which the flow path cross-sectional area expands as it moves from the air conditioner main body side to the switching box side.

7. The control device includes a mounting plate to which an operating member is attached, A cutout portion cut toward the driver's seat side is formed on the inner wall surface side of the mounting plate, The work machine according to any one of claims 1 to 6, wherein the flat portion is fitted into the cutout portion.

8. The relay duct is provided with a cup holder capable of holding a beverage container, A through hole is formed in the bottom surface of the cup holder, The work machine according to any one of claims 1 to 7, wherein a portion of the conditioned air taken out from an exhaust port of the air conditioner main body is discharged into the cup holder through the through hole.

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