Work Machine

Abstract

To provide a working machine that can minimize the frequency of tension adjustment for a transmission belt which drives a compressor.SOLUTION: The working machine includes a driving section 5 provided inside a cabin 40; an air conditioner unit that air-conditions the inside of the cabin 40; an engine room 6 provided below the driving section 5 and housing an engine 61; a compressor 45 for air conditioning provided in a location away from the engine 61 in the engine room 6; a transmission belt 70 wound around an output pulley 61b on the engine 61 and an input pulley 45b on the compressor 45; and a tension mechanism 7 for elastically tensioning the transmission belt.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a work machine that includes a cabin in which a driver sits and an air conditioning unit that conditions the interior of the cabin. [Background technology]

[0002] As an example of such a working machine, a combine harvester is already known, as described in Patent Document 1. In the combine harvester described in Patent Document 1, an air conditioning unit is installed in the roof of the cabin, and an air conditioning compressor is installed together with the engine in an engine room located below the cabin. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2015-123789 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the above conventional combine harvester, a transmission belt is wound around an output pulley provided on the output shaft of the engine and an input pulley of the air conditioning compressor, so that the engine power can be used to drive the compressor. A member supporting the air conditioning compressor in the engine room is attached to a base stay that is attached integrally to the engine. In this structure, when the transmission belt becomes loose and the tension needs to be adjusted, the distance between the output pulley and the input pulley is changed. Although tension adjustment is not required very often, the engine and compressor are located deep inside the engine compartment, and outside of them are the fan shroud, as well as accessories such as the radiator and oil cooler, various pipes, and even a dust cover attached to the outside. In other words, to adjust the tension of the transmission belt, it is necessary to disassemble and remove the various devices that are intertwined in the small space outside the engine and compressor, and this disassembly and reassembly requires a great deal of effort, which is troublesome. In a structure like this, in which the compressor is attached to the base stay and receives vibrations in sync with the engine, misalignment of the vibration direction between the output pulley and the input pulley is unlikely to occur, and the belt is relatively unlikely to become loose. However, for example, if the compressor is supported on the machine frame at a position separate from the engine, the vibration patterns of the output pulley and the input pulley differ, and the belt tends to become loose more frequently.

[0005] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide a working machine which minimizes the need to adjust the tension of a transmission belt for driving a compressor. [Means for solving the problem]

[0006] The features of the working machine of the present invention are as follows: The cabin and A driving section provided inside the cabin; An air conditioning unit that cools the inside of the cabin, an engine room provided below the driving section and housing an engine; an air conditioning compressor is provided in the engine room at a location away from the engine; A transmission belt is wound around an output pulley of the engine and an input pulley of the compressor, A tension mechanism is provided to elastically apply tension to the transmission belt. and the tension mechanism includes a tension roller that acts on the transmission belt, a tension arm that supports the tension roller, a spring that elastically biases the tension arm toward the tension side of the transmission belt, and an adjustment mechanism that adjusts the biasing force of the spring, a lower part of the operation unit is provided with an inspection port communicating with the engine room and a lid body capable of opening and closing the inspection port, the adjustment mechanism is arranged at a position operable from the operation unit side through the inspection port, the tension arm includes a first arm portion extending in the front-rear direction and a second arm portion extending in the vertical direction, and is formed in a bell crank shape that is swingably configured such that the first arm portion operates in the vertical direction as the second arm portion operates in the front-rear direction, the spring applies an elastic biasing force forward to the second arm portion, the adjustment mechanism is provided at a position forward of the spring so as to be adjustable, The point is...

[0007] According to this characteristic configuration, a tension mechanism is provided that elastically applies tension to the transmission belt wound around the output pulley of the engine and the input pulley of the compressor, so that even if the transmission belt stretches or slackens, tension can be applied by the elastic biasing force of the tension mechanism. This eliminates the need to remove and replace various devices and pipes around the engine to adjust the tension, and reduces the labor required for tension adjustment. Furthermore, by mounting the air conditioning compressor on the aircraft frame at a location away from the engine, rather than supporting it as if it were integrated with the engine, there is the advantage that it can be mounted in any location without being restricted by the engine's mounting position, thereby increasing design freedom. In this case, the engine and the compressor may be subjected to vibrations with different vibration periods and directions. In addition, due to the interruption of power in a power transmission system to another device linked to another pulley equipped on the engine, an external force is generated in a direction twisting the entire engine mounted with anti-vibration rubber or the like around the vertical axis, which may cause a change in the distance between the output pulley and the input pulley, causing repeated slack and tension, which may lead to elongation of the transmission belt. For these reasons, it has been common practice to support air conditioning compressors integrally with the engine, but by adopting the above-mentioned tension mechanism, it is easy to increase the degree of freedom in design so that the compressor can be located at any location away from the engine.

[0008]

[0009] alsoThe tension mechanism is equipped with a spring that elastically biases the tension arm supporting the tension roller toward the tension side of the transmission belt, and an adjustment mechanism that adjusts the spring's biasing force.The adjustment mechanism can be operated through an inspection hatch located in a position that can be operated from the driver's unit, so that the spring's biasing force can be easily adjusted from the driver's unit through the inspection hatch. moreover, the tension roller is supported by a first arm portion extending in the front-rear direction so as to operate in the vertical direction as the second arm portion extending in the vertical direction operates in the front-rear direction. And it is possible to adjust the elastic biasing force by the adjustment mechanism at a position forward of the spring that applies the elastic biasing force forward to the second arm portion. The adjustment operation by the adjustment mechanism can be performed at a position closer to the upper side and the front side by effectively using the arrangement configuration of the tension mechanism itself, making it easier to perform the operation from the operation unit.

[0010] Further, in the present invention, The output pulley is provided at a lower portion of the engine compartment, The input pulley is provided forward of the output pulley, The tension roller is provided at a position where it acts on the inner peripheral surface of the transmission belt. are It is preferable that:

[0011] According to this characteristic configuration if The tension roller acting on the inner peripheral surface of the transmission belt moves vertically in accordance with the front-rear movement of the second arm portion extending vertically. is Although the pulley is located at the bottom of the engine compartment, the adjustment mechanism allows for easy adjustment. is easy to perform from the operation unit.

[0012] Further, in the present invention, The driver's seat is provided in the driver's section, The engine compartment is provided below the driver's seat, An inspection hatch is provided in a seat frame supporting the driver's seat or in a floor part of the driver's section, The inspection hatch is provided at a location where the rear portion of the floor can be opened, The adjustment mechanism is preferably provided below the rear of the floor portion.

[0013] According to this characteristic configuration, the inspection hatch provided in the driver's section can be opened to operate the adjustment mechanism provided below the rear of the floor section.

[0014] Further, in the present invention, The adjustment mechanism is preferably attached to a frame body that supports a floor portion of the driver's section.

[0015] According to this characteristic configuration, no special support member is required for disposing the adjustment mechanism below the driver's section, and the frame body that supports the floor section can be effectively used to simplify the support structure.

[0016] Further, in the present invention, The engine room is of the operation unit The vehicle is divided into a front chamber located below the floor and a rear chamber located behind the floor, the engine and the compressor are provided in the rear chamber, A heat shield is provided between the front chamber and the rear chamber to limit heat conduction, The adjustment mechanism is preferably provided in the front chamber through the heat shield.

[0017] According to this characteristic configuration, the engine room is divided into a rear room in which the engine and compressor are located, and a front room located below the floor, and a heat shield is provided between the front room and the rear room, making it possible to create a structure in which the thermal effects of the high temperature gas in the rear room are less likely to be transmitted to the operating section. Furthermore, since the adjustment mechanism is provided in the front chamber through the heat shield, there is no need to remove or attach the heat shield, and the biasing force of the spring provided by the adjustment mechanism can be easily adjusted. [Brief description of the drawings]

[0018]

Figure 1

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[0019] Hereinafter, an example of an embodiment of the present invention will be described with reference to the drawings. In addition, the front-rear direction and the left-right direction in the description of this embodiment are described as follows unless otherwise specified. That is, in a normal combine harvester to which the present invention is applied, the forward traveling direction (see arrow F in Figs. 1 and 2) when the traveling body is traveling for work is "forward", the backward traveling direction (see arrow B in Figs. 1 and 2) is "rear", the direction corresponding to the right side based on the forward posture in the front-rear direction (see arrow R in Fig. 2) is "right", and similarly the direction corresponding to the left side (see arrow L in Fig. 2) is "left".

[0020] Hereinafter, an embodiment of the present invention will be described with reference to the drawings, in which the embodiment is applied to a normal combine harvester, which is an example of a working machine.

[0021] [Overall configuration of the combine] 1 to 3 show a normal type combine harvester. This combine harvester has a machine frame 1 supported by a pair of left and right crawler traveling devices 2, and a pre-reap processing section 3 is disposed in front of the machine frame 1. A threshing device 10 and a grain storage tank 12 are provided on the machine frame 1 in a side-by-side arrangement on the left and right sides. A feeder 11 for transporting harvested cereals is connected to the front of the threshing apparatus 10. The front end of the feeder 11 is connected to the rear of the pre-harvesting treatment section 3, and the rear end is supported so as to be able to swing up and down about a horizontal axis (not shown) provided near the front of the threshing apparatus 10. In other words, the front end of the feeder 11 is supported so as to be able to move up and down together with the pre-harvesting treatment section 3 as the lifting hydraulic cylinder 14 provided at the bottom of the feeder 11 expands and contracts.

[0022] The pre-harvesting processing section 3 is equipped with a pair of left and right grass dividing frames 3A with a cutting width approximately equivalent to the width of the machine body, and is structured such that a clipper-type cutting device 3B and an auger 3C that feeds the harvested crops laterally to the middle of the cutting width are installed across the pair of left and right grass dividing frames 3A. A raking reel 3D that rakes in the planted culms backward and pulls them up is installed at the upper front part of the pre-harvesting processing section 3. The raking reel 3D rakes in the tips of the culms planted in the field backward while the cutting device 3B cuts them, and the harvested crops are collected in the center in the left-right direction by the auger 3C. The collected crops are handed over to a feeder 11 and sent to a whole-culm-input threshing device 10 at the rear.

[0023] The threshing machine 10 is equipped with a threshing drum 10A that threshes the crops fed from a feeder 11, a oscillating sorting device 10B that sorts the threshered crops, and a winnower 10C that supplies sorting air for winnowing to the oscillating sorting device 10B. A winnower protection plate 15 is provided on the machine frame 1 below the area where the winnower 10C is located to prevent stones and the like from the field from flying into the peripheral wall of the winnower 10C, or from coming into contact with other objects and causing deformation (see FIG. 3).

[0024] Of the threshed crops, impurities such as stalks and weeds are shredded and discharged outside the machine, and the grains that have been sorted to remove the impurities are sent to a grain storage tank 12. A grain discharge device 13 that discharges the grains in the grain storage tank 12 to the outside is provided at the rear of the grain storage tank 12. The grain storage tank 12 can be opened and closed by swinging about an axis Z1 that extends in the vertical direction between a work position and a maintenance position.

[0025] [Control section] A control section 4 is provided on the right side of the front part of the aircraft frame 1. The control section 4 is equipped with a driver's section 5 where a driver can sit and operate the vehicle, and a cabin 40 that covers the driver's section 5. An engine room 6 is provided below the driver's section 5.

[0026] 3 to 7, the cabin 40 is provided with a roof portion 41, a windshield 42, and an entry / exit door 43. An air conditioning unit 44 that conditions the interior of the cabin 40 is installed inside the roof portion 41. An air conditioning compressor 45 that supplies refrigerant to the air conditioning unit 44 is provided in the engine room 6, which will be described later.

[0027] As shown in Figures 3 to 6, the driver's section 5 is equipped with a driver's seat 51 and a driving operation device 50 for steering the aircraft and operating the work equipment. A floor 52 serving as a boarding deck is provided below and in front of the driver's seat 51, and boarding and disembarking doors 43 of the cabin 40 can be opened and closed to enable boarding and disembarking from outside the aircraft. The driver's seat 51 and the driving operation device 50 are arranged so that the driver can operate the aircraft while seated in the driver's seat 51 and with his / her feet on the floor 52.

[0028] [Engine Room] As shown in FIG. 1, the engine room 6 located below the driver's station 5 is a space partitioned into a front room 6F located at a position corresponding to below the floor 52, and a rear room 6R located rearward of the floor 52 and below the location where the driver's seat 51 is located.

[0029] 4 to 7, the front compartment 6F is a space surrounded by a cabin support base 16 (corresponding to a frame body) that supports the cabin 40 at a position below the lower end of the cabin 40. Inside this space, as shown in FIG. 4, electrical components such as a battery 17 are disposed. The cabin support base 16 includes a pair of left and right front support pillars 16F, 16F and a pair of left and right rear support pillars 16R, 16R that support a floor portion 52, and fixes the floor portion 52 of the cabin 40 to the aircraft frame 1. As shown in Figures 1 and 5 and 6, a ladder member 18 is attached to the outer right side of the cabin support base 16 to make it easier for passengers to get on and off the aircraft by putting their feet on it from outside the aircraft.

[0030] As shown in Figs. 5 to 7, of the left and right rear support pillars 16R, 16R, two diagonal bracing members 16A, 16B are connected to the left rear support pillar 16R located inside the aircraft in the left-right direction. The two brace members 16A, 16B are a first brace member 16A connecting the left rear support 16R to the right rear support 16R, and a second brace member 16B connecting the left rear support 16R to the aircraft frame 1 located laterally to the left. The two brace members 16A, 16B are both provided at an angle so that the height of the end connected to the left rear support 16R is higher than the height of the connection point with the right rear support 16R, which is the counterpart, and the height of the connection point with the aircraft frame 1 located laterally to the left. This is because the two brace members 16A, 16B are provided at an angle so that they can effectively function as braces for the left rear support 16R, and effectively increase the strength of the entire cabin support base 16 against lateral shaking in the left and right directions.

[0031] The rear chamber 6R is provided behind the front chamber 6F. The rear compartment 6R is provided with a bonnet 60 whose upper end is located higher than the upper end of the front compartment 6F. The bonnet 60 is located at the back of the cabin 40, which is located higher than the upper end of the front compartment 6F, and serves as a part of the back wall of the cabin 40 and also as a mounting base (corresponding to a seat frame) for the driver's seat 51.

[0032] In the rear compartment 6R, within a bonnet 60, an engine 61 is provided in a state where it is rubber mounted to the vehicle frame 1 via vibration isolators 62. The bonnet 60, although not shown in the drawings, has its rear wall located near the front of the grain storage tank 12 and no dedicated partition walls on its left and right lateral sides. That is, at the location corresponding to the right lateral side of the bonnet 60, as shown in FIGS. 5 and 1, the fan shroud 63, the oil cooler 64, the radiator 65, etc. are erected in a state of being located on the right lateral outer side of the engine 61, and further, a dust cover 66 is attached to the outside in an openable and closable manner. Thus, on the right lateral side of the bonnet 60, although the right lateral side of the bonnet 60 is blocked in appearance by the related devices that are intricately located on the right lateral side of the engine 61, it is configured to allow ventilation from the right lateral side to the center side of the machine body through the dust cover 66. And the left lateral side of the bonnet 60 is open, although not shown in the drawings. At this part, the discharge direction of the cooling exhaust air from the cooling fan 61c is configured to face the left side where the feeder 11 is located.

[0033] 〔Drive Structure of Air Conditioning Compressor〕 As shown in FIGS. 4 to 7, in the rear chamber 6R, at a location in front of the engine 61, an air conditioning compressor 45 for supplying and discharging the refrigerant of the air conditioner unit 44 is provided. This air conditioning compressor 45 is not supported by the engine 61 in the rear chamber 6R, but is fixed to a mounting bracket 46 attached to the machine body frame 1.

[0034] Power transmission from the engine 61 to the air conditioning compressor 45 is performed using a transmission belt 70. The transmission belt 70 is stretched between an output pulley 61b provided on the output shaft 61a of the engine 61 and an input pulley 45b provided on the input shaft 45a of the air conditioning compressor 45. For this transmission belt 70, a tension mechanism 7 that elastically applies tension is used to apply tension to the tension side.

[0035] The tension mechanism 7 includes a tension roller 71 that abuts against and presses the inner surface of the transmission belt 70, a tension arm 72 that supports the tension roller 71, a spring 73 that elastically biases the tension arm 72 toward the tension side of the transmission belt 70, and an adjustment mechanism 74 that adjusts the biasing force of the spring 73. The tension arm 72 is bent into a bell crank shape and includes a first arm portion 72a extending in the front-rear direction, a second arm portion 72b extending in the up-down direction, and a boss portion 72c provided at the bent portion. The tension arm 72 is configured to be swingable so that the first arm portion 72a moves up and down in accordance with the movement of the second arm portion 72b in the front-rear direction.

[0036] The output pulley 61 b ​​is provided on the output shaft 61 a of the engine 61 and is therefore located at a lower position within the engine compartment 6 . The input pulley 45b is located in the engine compartment 6 and forwardly away from the output pulley 61b. The tension arm 72 is supported by a mounting bracket 46 fixed to the machine frame 1. In other words, a boss portion 72c provided at a bent portion of the tension arm 72 is fitted onto a support shaft 46b provided on a rising frame 46a of the mounting bracket 46. As a result, the tension arm 72 is pivotally supported so as to be rotatable about an axis concentric with the support shaft 46b.

[0037] 4 to 7, a spring 73 that elastically biases the tension arm 72 toward the tension side of the transmission belt 70 is connected to the second arm portion 72b of the tension arm 72. One end of this spring 73 is engaged with the free end of the second arm portion 72b, and the other end is engaged with an adjustment mechanism 74. The adjustment mechanism 74 is configured to be able to adjust the elastic biasing force at a position forward of the spring 73.

[0038] The adjustment mechanism 74 includes an adjustment rod 74a having one end engaged with the spring 73 and equipped with a threaded shaft portion, and a pair of adjustment nuts 74b, 74b that screw into the threaded shaft portion of the adjustment rod 74a. With the other end of the adjustment rod 74a inserted into the adjustment bracket 16C, the positions of the adjustment nuts 74b, 74b provided at the front and rear of the adjustment rod 74a are adjusted to change the elastic biasing force of the spring 73. The adjustment bracket 16C is an L-shaped bracket in a plan view that is erected on the upper surface of the first diagonal brace member 16A that connects the left rear support column 16R and the right rear support column 16R, and has a hole 16Ca through which the adjustment rod 74a can be inserted and removed.

[0039] A heat shield 67 is provided at the boundary between the rear chamber 6R and the front chamber 6F to limit heat conduction between the front chamber 6F and the rear chamber 6R. An opening 67a is provided in a part of the heat shield 67 so that the adjustment rod 74a can be inserted and removed without difficulty. Therefore, the adjustment mechanism 74 of the tension mechanism 7 is extended beyond the location of the heat shield 67 from the rear chamber 6R side to the front chamber 6F side so that adjustment can be performed on the front chamber 6F side.

[0040] [Inspection hatch] As shown in Figures 4 to 7, the floor 52 of the driver's section 5 is provided with an inspection hatch 53 communicating with the engine room 6, a lid 54 that can open and close the inspection hatch 53, and a connecting bolt 55 that can tighten and secure the lid 54. 7, the inspection hatch 53 is an opening cut into a rectangle including the rear end edge 52a of the floor 52, and is provided in a location directly above the location of the threaded shaft portion of the adjustment rod 74a and the adjustment nuts 74b, 74b in the adjustment mechanism 74. The size of the opening is set so that an operator can easily operate the threaded shaft portion of the adjustment rod 74a and the adjustment nuts 74b, 74b from the floor 52.

[0041] [Lifting hydraulic cylinder] The lifting hydraulic cylinder 14 provided at the bottom of the feeder 11 is constructed as follows. As shown in FIG. 8, the lifting hydraulic cylinder 14 is made up of a cylinder tube 14A and a piston rod 14B, and a pressure oil supply / discharge port 14Aa is formed on the swing fulcrum side of the cylinder tube 14A (the side connected to the machine frame 1). On the inner circumferential surface side of the cylinder 14A, near the end opposite the swing fulcrum side, there is provided an external support collar 19a made of resin that fits onto the outer circumferential surface of the shaft portion 14Bb of the piston rod 14B to slidably support the piston rod 14B.

[0042] The piston rod 14B has a shaft portion 14Ba on the opposite side to the tip side (the side connected to the feeder 11) inserted into the cylinder 14A, and flange-shaped piston portions 14C, 14C having a diameter slightly larger than that of the shaft portion 14Ba are provided near the shaft end on the inserted side. These flange-shaped piston portions 14C, 14C have a diameter slightly larger than that of the shaft portion 14Ba, and are formed at two locations spaced a predetermined distance apart in the direction of extension and contraction of the piston rod 14B. At the end of the cylinder 14A further inside than the flange-shaped piston portions 14C, 14C, a small diameter shaft portion 14Bb having a smaller diameter than the shaft portion 14Ba further toward the tip side than the flange-shaped piston portions 14C, 14C is formed so as to be positioned opposite the pressure oil supply and discharge port 14Aa. A resin internal support collar 19b is attached in the space between the flange-shaped piston portions 14C, 14C to slide the piston rod 14B while supporting it on the inner peripheral surface of the cylinder 14A. Although not shown, the internal support collar 19 has a slit formed therein that allows the passage of lubricating oil in the axial direction to drain the oil from the shaft portion 14Bb of the piston rod 14B.

[0043] By forming two locations (or three or more locations) spaced apart by a distance in the extension / retraction direction of the piston rod 14B, such as the location where the external support collar 19a and the location where the internal support collar 19b are located, where the piston rod 14B can be fitted relatively tightly into the cylinder tube 14A to maintain a stable sliding posture, it is easier to maintain a stable extension posture of the lifting hydraulic cylinder 14. As a result, even when the lifting hydraulic cylinder 14 is greatly extended, the piston rod 14B is stably supported over a wide range equivalent to multiple points in the longitudinal direction, and the support between the cylinder tube 14A and the piston rod 14B in the extended state is easily maintained stably with little wobble.

[0044] [Kara-wine protection board] A winnowing machine protection plate 15 for protecting the peripheral wall portion of the winnowing machine 10C is provided on the machine frame 1 below the portion where the winnowing machine 10C is located. 8, this winnower protection plate 15 has three sides 15a, 15b, and 15c that contact the machine frame 1, of which adjacent two sides 15a and 15b are fixed to the machine frame 1 by welding. The remaining side 15c is connected to a connecting bracket 1a provided on the machine frame 1 by a bolt 1b. In other words, if the opposing ends of the winnowing basket protective plate 15 were welded to the machine frame 1, the distance between the opposing ends would change slightly due to vibration or twisting of the machine, and this repeated action would tend to increase the likelihood of the welded points deteriorating, so the welds are located at adjacent points, and one of the opposing ends is connected with a bolt, thereby reducing the effects of subtle changes in distance.

[0045] [Another embodiment] Other embodiments will be described below. The following embodiments may be combined with each other and applied to the above embodiment as long as no contradiction occurs. Note that the scope of the present invention is not limited to the contents of these embodiments.

[0046] (1) In the above-described embodiment, an example of the inspection hatch 53 is an opening cut into a rectangle that includes the rear edge 52a of the floor 52 and is open on the side of the rear edge 52a, but the inspection hatch 53 is not necessarily limited to this structure. For example, the inspection hatch 53 may be provided at a location slightly forward, away from the rear edge 52a of the floor portion 52, to form a rectangular opening that forms a closed loop, or may be an opening of a shape other than rectangular, such as a circle. Also, instead of providing an opening in a part of the floor portion 52, the entire floor portion 52 may be made detachable, and the removed part of the floor portion 52 may be used as the inspection hatch 53. The other configurations may be the same as those of the above-described embodiment.

[0047] (2) In the above-described embodiment, an example was given of a structure in which the inspection hatch 53 is formed in the floor portion 52, but this is not limited thereto. The inspection hatch 53 may also be formed in the front wall portion of the bonnet 60, which serves as a mounting base for the driver's seat 51, although this is not shown in the figures. In addition, the inspection hatch 53 formed in the front wall portion of the bonnet 60 may be extended to the floor portion 52, or the inspection hatch 53 may be formed in both the front wall portion of the bonnet 60 and the floor portion 52. The other configurations may be the same as those of the above-described embodiment.

[0048] (3) In the above embodiment, the heat shield 67 is provided at the partition between the front compartment 6F and the rear compartment 6R of the engine compartment 6, but this heat shield 67 may be omitted. The other configurations may be the same as those of the above-described embodiment.

[0049] (4) In the above-described embodiment, the adjustment mechanism 74 is exemplified as a structure in which the elastic force of the spring 73 is adjusted by screwing together the adjustment rod 74a engaged with the spring 73 and the adjustment nuts 74b, 74b. However, the adjustment mechanism 74 is not limited to this structure and any other appropriate structure for adjusting the elastic force of the spring 73 can be adopted. The other configurations may be the same as those of the above-described embodiment. [Industrial Applicability]

[0050] The present invention can be used not only in normal type combine harvesters, but also in head-feeding type combine harvesters and other working machines. [Explanation of symbols]

[0051] 5. Driving section 6. Engine Room 6F front room 6R rear compartment 7 Tension mechanism 8 Cabin 16A Frame body 40 Cabin 44 Air Conditioning Unit 45 Air conditioning compressor 45b Input pulley 51 Driver's seat 52 Floor 53 Inspection hatch 54 Lid 61 Engine 61b Output pulley 67 Heat shield 70 Transmission Belt 71 Tension roller 72 Tension Arm 72a First arm 72b Second arm part 73 Spring 74 Adjustment mechanism

Claims

1. The cabin and A driving section provided inside the cabin; An air conditioning unit that cools the inside of the cabin, an engine room provided below the driving section and housing an engine; an air conditioning compressor is provided in the engine room at a location away from the engine; A transmission belt is wound around an output pulley of the engine and an input pulley of the compressor, A tension mechanism is provided to elastically apply tension to the transmission belt, The tension mechanism includes a tension roller that acts on the transmission belt. A tension arm supporting the tension roller; a spring that elastically biases the tension arm toward the tension side of the power transmission belt; and an adjustment mechanism for adjusting the biasing force of the spring. A lower portion of the driving section is provided with an inspection hatch communicating with the engine room and a lid body capable of opening and closing the inspection hatch, The adjustment mechanism is disposed at a location operable from the driver's side through the inspection hatch, the tension arm is formed in a bell crank shape including a first arm portion extending in a front-rear direction and a second arm portion extending in a vertical direction, and is configured to be swingable so that the first arm portion moves in the vertical direction in response to the front-rear movement of the second arm portion, The spring applies a forward elastic force to the second arm portion, The adjustment mechanism is provided so as to be adjustable at a position forward of the spring.

2. The output pulley is provided at a lower part of the engine room, The input pulley is provided forward of the output pulley, 2. The work machine according to claim 1, wherein the tension roller is disposed at a position where it acts on an inner peripheral surface of the transmission belt.

3. The driver's seat is provided in the driver's section, The engine compartment is provided below the driver's seat, An inspection hatch is provided in a seat frame supporting the driver's seat or in a floor part of the driver's section, The inspection hatch is provided at a location where the rear portion of the floor can be opened, 2. The work machine according to claim 1, wherein the adjustment mechanism is provided below a rear portion of the floor portion.

4. 2. The work machine according to claim 1, wherein the adjustment mechanism is attached to a frame body that supports a floor portion of the driver's section.

5. The engine room is divided into a front room located below a floor of the driver's section and a rear room located behind the floor, the engine and the compressor are provided in the rear chamber, A heat shield is provided between the front chamber and the rear chamber to limit heat conduction, 5. The work machine according to claim 1, wherein the adjustment mechanism is provided in the front chamber, passing through the heat shield.

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