WO2012035981A1

WO2012035981A1 - Work vehicle

Info

Publication number: WO2012035981A1
Application number: PCT/JP2011/069750
Authority: WO
Inventors: 進野口; 松本　邦彦; 赤嶋　晋; 小松　正和
Original assignee: ヤンマー株式会社
Priority date: 2010-09-14
Filing date: 2011-08-31
Publication date: 2012-03-22
Also published as: CN102892612A; CN102892612B

Abstract

It is possible to stably and compactly position a large-volume fuel tank in a work vehicle such as a tractor. A traveling body (1) has a seat bracket (16) supported by a transmission case (11) and a rear housing (217). A steering seat (12) is mounted to the seat bracket (16). When seen in planar view, a fuel tank (26) appears substantially L-shaped and wraps around the rear and right side of the steering seat (12). The fuel tank (26) is supported by the seat bracket (16). The fuel tank (26) is positioned so as to make use of the dead space around the steering seat (12); therefore, even in the case that the fuel tank (26) is a large-volume tank, the traveling body (1) can be compactly made. The seat bracket (16) for supporting the steering seat (12) is also used to support the fuel tank (26); therefore, it is possible to prevent complication of structure.

Description

Work vehicle

The present invention relates to a work vehicle such as a tractor for agricultural work or a wheel loader for civil engineering work.

A work vehicle driven by an engine generally has a control seat, and an operator sits on the control seat and controls the work vehicle. In many cases, the pilot seat can be adjusted in the front-rear position so as to correspond to the physique and preferences of the operator. Therefore, the pilot seat is often attached to the seat bracket so as to be movable back and forth.

Also, the traveling aircraft is equipped with a fuel tank that supplies fuel to the engine. In the case of a tractor, it is almost the case that the engine is arranged at the front part of the traveling body. For example, Patent Document 1 discloses that the fuel tank is arranged behind the control seat. If the engine and the fuel tank are arranged separately at the front and rear of the control seat, the fuel in the fuel tank is sent to the engine by the fuel feed pump, and a fuel filter is placed upstream of the fuel feed pump. ing.

The fuel tank must be held in a stable state on the vehicle body. Conventionally, as a means for holding the fuel tank, a flange is formed on the outer periphery of the fuel tank and this flange is fixed to the machine frame of the vehicle body with bolts. Or tied the fuel tank to the frame of the traveling aircraft with a band.

In a work vehicle, a steering handle for steering the traveling aircraft and a plurality of lever members for setting and adjusting the traveling state of the traveling aircraft are arranged around the steering seat in consideration of operability. Has been. For example, a farm tractor has a main transmission lever, a sub-transmission lever, a forward / reverse switching lever, a drive switching lever, a PTO transmission lever, and the like as a plurality of lever members (see Patent Document 2, etc.).

The main transmission lever is used to change the vehicle speed of the traveling machine body, and the auxiliary transmission lever is used to set and hold the transmission output of the transmission within a predetermined range. The forward / reverse switching lever switches the traveling direction of the traveling machine body between forward and backward, and the drive switching lever switches the driving system of the traveling machine body between 2WD and 4WD. The PTO shift lever is used to shift the output (PTO driving force) to the work machine.

JP 2007-302049 A JP 2005-297710 A

Now, as a method of fixing the fuel tank, forming a flange and fixing it to the machine frame with a bolt has a high holding function, but the structure is complicated because a receiving part of the fuel tank must be provided on the machine frame, etc. May cause problems. On the other hand, fixing with a band is simple and relatively easy to work, but has a problem of poor stability. In particular, when the fuel tank is enlarged, there is a high possibility that the reliability is lacking.

On the other hand, the fuel is often sent to the engine via the fuel filter and the fuel feed pump, but conventionally, the fuel filter and the fuel feed pump are often separately attached to the machine frame, etc. There is a problem that it takes time and effort.

By the way, each of the conventional levers can be pivoted about each pivotal support shaft by supporting the base end side of the lever on a transmission, a traveling machine body or the like with a separate pivot shaft. It is configured. In this case, since the number of rotating support shafts corresponding to the number of levers is attached to the transmission, the traveling machine body, etc., there is a problem that the number of parts increases and the number of assembly steps in the production line increases, resulting in an increase in cost. is there.

The present invention has a technical problem to provide a work vehicle that solves the above problems.

The invention according to claim 1 is a work vehicle in which an operating seat on which an operator sits and a fuel tank that supplies fuel to the engine are disposed on a traveling body on which the engine is mounted, and the engine is located in front of the operating seat. The pilot seat is supported by a seat bracket, and the fuel tank is arranged behind the pilot seat, at a side, or both, and is supported by the seat bracket. It is what has been done.

According to a second aspect of the present invention, in the work vehicle according to the first aspect, the fuel tank is positioned at least on the rear side of the control seat, and has a side portion positioned on either the left or right side of the control seat. Is or does not have.

According to a third aspect of the present invention, in the work vehicle according to the second aspect, the control seat, the fuel tank, and the seat bracket have a unit structure.

According to a fourth aspect of the present invention, in the work vehicle according to the third aspect, the fuel filter and the fuel feed pump are attached to the auxiliary bracket, and the auxiliary bracket is attached to the fuel tank or the seat bracket. .

According to a fifth aspect of the present invention, in the work vehicle according to the fourth aspect, the fuel filter and the fuel feed pump are surrounded by the fuel tank, the auxiliary bracket, and the lops frame in a substantially plan view. is there.

According to a sixth aspect of the present invention, in the work vehicle according to the second aspect of the present invention, the work vehicle further includes a transmission case to which power is transmitted from the engine, and at least two lever members that are manually operated. The group is pivotally supported on a common pivot shaft so as to be pivotable.

According to a seventh aspect of the present invention, in the work vehicle according to the sixth aspect, the lever member group is formed of a common part, and a boss portion provided on each base end side is covered on the rotating support shaft. By fitting, the lever member groups are arranged side by side.

According to an eighth aspect of the present invention, in the work vehicle according to the seventh aspect, the rotating support shaft is detachably bolted to a side surface of a support bracket that supports the control seat from below.

According to a ninth aspect of the present invention, in the work vehicle according to the sixth aspect, the lever member group includes a PTO speed change lever for performing a speed change operation on an output to the work machine mounted on the travel machine body, and the travel machine body. Is a drive switching lever for switching the drive system between 2WD and 4WD, and both levers are arranged in a posture protruding forward below the control seat and on the left and right outside of the control seat. That's it.

In the invention of claim 1, since the fuel tank is supported using the seat bracket that supports the control seat, the fuel tank can be supported stably. Further, since the seat bracket is also used for supporting the fuel tank, it is possible to contribute to simplification of the structure.

Also, since the fuel tank is arranged not in the vicinity of the control seat but in the surrounding area, the height of the control seat does not increase due to the arrangement of the fuel tank. Therefore, the present invention can be applied to a work vehicle having no dead space below the control seat (if the control seat can be adjusted in the front-rear position, the front-rear slide function of the control seat is not impaired).

Furthermore, in the present invention, since the fuel tank is located in the region around the control seat, the center of gravity of the work vehicle can be shifted as far back as possible to improve the front-rear weight balance of the traveling machine body. In particular, when the fuel tank is positioned at least on the rear side of the control seat as in claim 2, it is possible to more reliably shift the center of gravity of the traveling aircraft to the rear. For example, a dozer is attached to the front end of the traveling aircraft. When performing earth pushing work, the rotating fulcrum of the dozer can be shifted backward to reduce the reaction force of the blade, which can prevent the front wheels from floating without providing a balancer, for example. become.

Now, a work vehicle is usually provided with an operation lever, and in this case, a lever group is often arranged in one of the left and right sides of the seat, and the other part is a dead space. It may be. And if the structure of Claim 2 is employ | adopted, since a fuel tank can be arrange | positioned using the dead space of the left side or the right side of a seat, the enlargement of a fuel tank can be promoted, making a traveling body compact. It is also possible to provide a side part in the fuel tank and to use the side part also as an elbow rest support part.

If the structure of Claim 3 is employ | adopted, since a fuel tank can be previously integrated in a control seat and a seat bracket, the assembly work of a work vehicle can be performed efficiently. Moreover, the trouble of disassembling the work vehicle can be saved.

If the configuration of claim 4 is adopted, the assembly efficiency can be improved by unitizing the fuel filter and the fuel feed pump. In addition, since the auxiliary bracket is attached to the fuel tank, the fuel filter and the fuel feed pump are unitized, so that the assembly of the work vehicle can be further improved.

The fuel filter and the fuel feed pump are preferably guarded against hitting from the side or the pebbles that have jumped up, but when the structure of claim 5 is adopted, the fuel tank, the auxiliary bracket, and the lops frame are Since it functions as a guard member for the fuel filter and the fuel feed pump, the safety of the fuel tank and the auxiliary bracket is ensured without incurring a complicated structure.

According to the invention of claim 6, the lever member group that is manually operated is pivotally supported by a common pivot shaft so as to be capable of being pivoted. This can be done with a pivot shaft. Therefore, there is an effect that the number of parts can be reduced and the number of assembly steps can be reduced.

According to the invention of claim 7, the lever member group is constituted by a common part, and the lever member group is formed by fitting a boss portion provided on each base end side to the rotating support shaft. Are arranged side by side, the lever member group can be shared, and the effect of contributing to cost reduction is achieved. The work of assembling work when manufacturing the work vehicle can also be reduced. In addition, there is an advantage that each lever member can be easily set and retrofitted.

According to the eighth aspect of the present invention, since the pivot support shaft is detachably bolted to the side surface of the support bracket that supports the control seat from below, the pivot support shaft can be easily removed. For this reason, for example, it is possible to easily perform grease replacement or replacement (good maintenance workability).

According to a ninth aspect of the present invention, the lever member group is a PTO speed change lever and a drive switching lever, and the both levers are arranged in a posture projecting forward below the control seat and on the left and right outside of the control seat. Thus, for example, the two levers that are operated less frequently than those directly related to traveling, such as the main shift lever, are placed as close to the pilot seat as possible but not so much in the way. Therefore, it is effective in view of the operation efficiency of the operator. It is also possible to operate both levers with feet when the operator cannot release the hand.

It is the whole tractor side view. It is a whole top view of a tractor. It is a skeleton figure which shows the power transmission system of a tractor in 1st Embodiment. It is a side view which shows the attachment structure of a drive switching lever and a PTO speed change lever. It is a top view which shows the attachment structure of a drive switching lever and a PTO speed change lever. It is a perspective view which shows the attachment structure of a drive switching lever and a PTO speed change lever. It is a separation perspective view which shows the attachment structure of a drive switching lever and a PTO speed change lever. It is a perspective view of the figure of the traveling body which omitted the first half part. It is a separate perspective view of the principal part. (A) is the perspective view which looked at the fuel tank from the lower part, (B) is the perspective view which shows a seat bracket. (A) is a perspective view in the state which turned over the principal part, (B) is a bottom view which shows an oil feeding unit. (A) is the perspective view which looked at the principal part from diagonally downward, (B) is the perspective view which looked from diagonally back downward. (A) is the perspective view which looked at the fuel tank from back, (B) is the perspective view of an oil feeding unit. It is typical explanatory drawing at the time of providing a dozer. It is a perspective view which shows the framework of a tractor. It is a detailed explanatory view of a power transmission system. (A) is the isolation | separation side view of the principal part, (B) is a perspective view which shows a power transmission system. (A) is a separated side view of the main part, (B) is a perspective view of the rear end portion of the transmission case, and (C) is a separated front view of the transmission case and the front bearing body. It is a separate perspective view of the principal part. It is a sectional side view of the principal part. It is a perspective view of a clutch operation mechanism. FIGS. 2A and 2B are diagrams showing a rear wheel support structure, in which FIG. 1A is an overall plan view, FIG. 1B is a partial plan view, and FIGS. (A) is a perspective view of a tractor in a state in which a part is omitted, (B) is a perspective view of a part centered on a radiator, and (C) is a perspective view of a part centered on the radiator viewed from the front. . (A) is a perspective view of the principal part, (B) is a separated perspective view of the principal part. (A) is a diagram showing a first alternative example, (B) is a cross-sectional view taken along line BB of (A), (C) is a rear view showing a second alternative example, and (D) is a third alternative example. FIG.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

First, a schematic structure of a tractor 1 that is an example of a work vehicle will be described with reference to FIGS. 1 and 2. As shown in FIGS. 1 and 2, the traveling machine body 2 of the tractor 1 is supported by a pair of left and right front wheels 3 and a pair of left and right rear wheels 4. The tractor 1 is configured to travel forward and backward by driving the rear wheels 4 and the front wheels 3 with the engine 5 mounted on the front portion of the traveling machine body 2. The traveling machine body 2 includes an engine frame 8 having a front bumper 6 and a front axle case 7, a clutch housing 10 incorporating a main clutch 9 (see FIG. 3) that interrupts power from the engine 5, and power from the engine 5. Is suitably constituted by a transmission case 11 for transmitting to the both rear wheels 4 and both front wheels 3 and a pair of left and right step frames 13 projecting outward from the outer surface of the clutch housing 10. The rear end side of the engine frame 8 is connected to the left and right outer surfaces of the engine 5. The front side of the clutch housing 10 is connected to the rear side of the engine 5. The front side of the transmission case 11 is connected to the rear side of the clutch housing 10.

The engine 5 is covered with a bonnet 14. A steering column 15 is erected on the upper surface of the clutch housing 10. A steering handle 16 for changing the steering angle (steering angle) of the left and right front wheels 3 is disposed on the upper surface side of the steering column 15. A control seat 17 is arranged on the upper surface of the mission case 11. On the upper surface of the left and right step frames 13, a flat step floor plate 18 is disposed so as to straddle them. The front wheel 3 is attached to the engine frame 8 via a front axle case 7. The rear wheel 4 is attached via a rear axle case 19 projecting outward from the outer surface of the mission case 11. The upper surface side of the left and right rear wheels 4 is covered with a pair of left and right rear cowls 20. Behind the control seat 17 are provided a fuel tank 21 for storing fuel supplied to the engine 5 and a lops frame 22 for protecting the operator when the traveling machine body 2 falls.

On the rear upper surface of the mission case 11, a hydraulic work machine lifting mechanism 23 that lifts and lowers a work machine (not shown) connected to the rear part of the traveling machine body 2 is detachably attached. In this case, the work implement is connected to the rear portion of the mission case 11 via a three-point link mechanism 24 including a pair of left and right lower links 25 and a top link 26. The left and right lift arms 27 in the work implement lifting mechanism 23 are connected to the left and right lower links 25 via lift links 28. The work implement is moved up and down by the vertical rotation of the left and right lift arms 27 by the work implement lifting mechanism 23. On the rear side surface of the transmission case 11, a PTO shaft 29 for transmitting a PTO driving force to the work machine is provided so as to project rearward.

Next, an arrangement structure of various operation members around the control seat 17 will be described with reference to FIGS. As shown in FIGS. 1 and 2, a steering column 15 is disposed in front of the steering seat 17, and a steering handle 16 for steering operation is disposed on the upper surface side of the steering column 15. An operation display panel 31 is provided on the upper surface side of the steering column 15. On one side of the control column 15, a forward / reverse switching lever 32 for switching the traveling direction of the traveling machine body 2 between forward and reverse, and a clutch pedal 33 for disengaging the main clutch 9 are arranged. ing. On the other side of the steering column 15, an accelerator lever 34 that adjusts the rotational speed of the engine 5 and a pair of left and right brake pedals 35 that perform a braking operation on the traveling machine body 2 are provided. An accelerator pedal 36 is disposed on the outer side of the brake pedal 35 when viewed from the steering column 15 side. The accelerator pedal 36 increases and decreases the rotational speed in a range beyond this, with the rotational speed of the engine 5 set by the accelerator lever 34 as a lower limit. Although not shown, a parking brake lever that holds the brake pedal 33 in the depressed position is provided on the back side of the steering column 15.

A side column 37 is provided at the left and right front portions of the control seat 17. On one side column 37, the sub-transmission lever 38 that sets and holds the shift output of the sub-transmission mechanism 53 (see FIG. 3) in the mission case 11 within a predetermined range, and the drive system of the traveling machine body 2 are driven in two ways. A drive switching lever 39 for switching between the four-wheel drive and a PTO shift lever 40 for shifting the PTO drive force to the work machine are arranged. As is clear from FIG. 2, the drive switching lever 39 and the PTO speed change lever 40 are arranged in a posture protruding forward below the control seat 17 and on the left and right outside of the control seat 17. In the embodiment, the drive switching lever 39 and the PTO speed change lever 40 constitute a lever member.

On the other side column 37, a main transmission lever 41 for changing the vehicle speed of the traveling machine body 2, a position lever 42 for manually changing and adjusting the height position of the work implement, and on / off switching of the work implement lifting control. And a draft lever 43 for setting control sensitivity. A plurality of sub-control valve levers 44 for switching a sub-control valve (not shown) provided on the rear upper surface of the transmission case 17 are arranged on the rear cowl 20 near the other side column 37. Here, the sub-control valve is for controlling supply of hydraulic oil to another work machine such as a front loader that is retrofitted to the tractor 1. A differential lock pedal 45 for turning on / off differential driving of the left and right rear wheels 4 is disposed in front of the other side column 37. Note that the left and right side columns 37 of the embodiment are integrally formed with the corresponding rear cowl 20.

Next, the power transmission system of the tractor 1 will be described with reference to FIG. As described above, the main clutch 9 for power disconnection is built in the clutch housing 10. In the transmission case 11, a forward / reverse switching mechanism 51 that switches the power of the engine 5 in the forward or reverse direction, and a mechanical main transmission mechanism 52 and a sub-transmission mechanism 53 that change the rotational power via the forward / reverse switching mechanism 51. A PTO transmission mechanism 54 for appropriately shifting the power of the engine 5 and transmitting it to the PTO shaft 29, and a differential gear mechanism 55 for transmitting the rotational power via the auxiliary transmission mechanism 53 to the left and right rear wheels 4. ing. In the cover case 56 provided on the lower surface side of the mission case 11, a two-wheel drive and four-wheel drive switching mechanism 57 for switching the drive system of the traveling machine body 2 between the two-wheel drive and the four-wheel drive is disposed.

The flywheel 59 is attached to the engine output shaft 58 that protrudes backward from the engine 5. The flywheel 59 and the main driving shaft 60 extending rearward from the flywheel 59 are connected via a main clutch 9 in the clutch housing 10. Similarly, the flywheel 59 and the input cylinder shaft 61 that is rotatably fitted to the main driving shaft 60 are also connected via the main clutch 9.

The power of the engine 5 is branched and transmitted from the engine output shaft 58 to the two systems of the PTO drive system via the main drive shaft 60 and the traveling system from the engine output shaft 58 via the input cylinder shaft 61. The rotational power transmitted to the main shaft 60 is transmitted to the PTO transmission mechanism 54, and the PTO driving force that is appropriately changed by the PTO transmission mechanism 54 is transmitted to the PTO shaft 29. Further, the rotational power transmitted to the input cylinder shaft 61 passes through the forward / reverse switching mechanism 51 and is appropriately shifted by the main transmission mechanism 52 and the auxiliary transmission mechanism 53. The transmission power is transmitted to the left and right rear wheels 4 via the differential gear mechanism 55. Shift power by the main transmission mechanism 52 and the subtransmission mechanism 53 is also transmitted to the left and right front wheels 3 via the two-wheel drive / four-wheel drive switching mechanism 57 and the differential gear mechanism 62 in the front axle case 7.

By operating the forward / reverse switching lever 32 to slide the forward / reverse switching clutch 63 along the input cylinder shaft 61, the rotational power from the engine 5 toward the main transmission mechanism 52 is transmitted in the forward direction or in the reverse direction. Whether to transmit is selected. The main speed change mechanism 52 is configured to change over a plurality of speeds (four speeds in the embodiment) by operating the main speed change lever 41. The sub-transmission mechanism 53 is configured to change gears in two steps of high and low by operating the sub-transmission lever 38. By operating the drive switching lever 39, the drive switching clutch 65 is slid along the front wheel propulsion shaft 64 that constitutes the two-wheel-drive / four-wheel-drive switching mechanism 57, so that the rotational power passing through the auxiliary transmission mechanism 53 is transferred to the front wheels 3. Whether or not to transmit to is selected. Further, by operating the PTO speed change lever 40, the PTO speed change clutch 66 is slid along the PTO shaft 29, whereby the PTO driving force is switched between two levels.

Next, the mounting structure of the drive switching lever 39 and the PTO speed change lever 40, which are examples of lever members, will be described with reference to FIGS. As shown in FIGS. 4 to 7, a support bracket 71 that supports the control seat from below is bolted to the upper surface of the mission case 11. On the front side of one side plate 71a of the support bracket 71, a rotation support shaft 72 that rotatably supports the drive switching lever 39 and the PTO speed change lever 40 is attached in a posture (sideways) projecting leftward and rightward. It has been. A substantially L-shaped fixing piece 73 is integrally provided on one end side of the rotation support shaft 72. The rotation support shaft 71 can be attached to and detached from the support bracket 71 by superimposing the flat plate portion 73a intersecting with the rotation support shaft 71 of the fixed piece 73 on one side plate 71a of the support bracket 71 and fastening with bolts. It is configured.

In addition, a through hole 74 for passing a harness is formed in a standing plate portion 73b extending in parallel with the rotation support shaft 71 in the fixed piece 73. By supporting the through hole 74 through the harness, interference between the drive switching lever 39 and the PTO speed change lever 40 and the harness existing in the vicinity thereof is avoided.

The drive switching lever 39 and the PTO speed change lever 40 are composed of common parts. By fitting the

bosses

79 and 80 welded and fixed to the respective base ends to the rotation support shaft 72, the drive switching lever 39 and the PTO speed change lever 40 are rotated up and down around the common rotation support shaft 72. They are arranged side by side in a movable state. A retaining ring 75 for retaining is detachably fitted to the outermost projecting end portion that penetrates both the

boss portions

79 and 80 of the rotating support shaft 72. Both

boss portions

79 and 80 are configured so as not to be detachable in the direction of the rotation support shaft 72.

Connection arms

81 and 82 pivotally attached to one end sides of the

corresponding relay rods

86 and 96 are fixed to the

boss portions

79 and 80, respectively.

As shown in FIGS. 4 to 6, from one side surface of the cover case 56, a drive switching shaft 83 that slides the drive switching clutch 65 in conjunction with the rotation projects outwardly. The drive switching shaft 83 and the rotation support shaft 72 extend in the same direction and in parallel. A drive switching boss body 84 that rotates integrally with the drive switching shaft 83 is fitted on the drive switching shaft 83 so that it cannot pass through. A switching arm 85 is fixed to the drive switching boss body 84. The connecting arm 81 on the drive switching lever 39 side and the switching arm 85 of the drive switching boss body 84 are interlocked and connected via a drive switching relay rod 86. A connecting arm 81 is rotatably connected to one end of the drive switching relay rod 86 via a pivot pin shaft 87. The other end side of the drive switching relay rod 86 is rotatably connected to the switching arm 85 via a pivot pin shaft 88.

When the drive switching lever 39 is rotated up and down around the rotation support shaft 72, the drive switching shaft 83 is rotated via the drive switching relay rod 86 and the drive switching boss body 84, and the drive switching clutch in the cover case 56. 65 is slid along the front wheel propulsion shaft 64. As a result, the rotational power passing through the auxiliary transmission mechanism 53 is transmitted to the front wheel 3 or cut off, so that the driving system of the traveling machine body 2 is switched between the 2WD and the 4WD.

From the rear side of one side of the mission case 11, a shift switching shaft 93 that slides the PTO shift clutch 66 in conjunction with the rotation projects outwardly. The shift switching shaft 93 also extends in the same direction and in parallel with the drive switching shaft 83 and the rotation support shaft 72. A shift switching boss body 94 that rotates integrally with the shift switching shaft 93 is fitted on the shift switching shaft 93 so that it cannot pass through. A switching arm 95 is fixed to the shift switching boss body 94. The connecting arm 82 on the PTO speed change lever 40 side and the switching arm 95 of the speed change switching boss body 94 are interlocked and connected via a PTO speed change relay rod 96. A connecting arm 82 is rotatably connected to one end of the PTO speed change relay rod 96 via a pivot pin shaft 97. The other end of the PTO speed change relay rod 96 is rotatably connected to a switching arm 95 via a pivot pin shaft 98.

When the PTO speed change lever 40 is turned up and down around the rotation support shaft 72, the speed change switching shaft 93 is turned via the PTO speed change relay rod 96 and the speed change change boss body 94, and the PTO speed change on the rear side of the transmission case 11 is performed. The clutch 66 is slid along the PTO shaft 29. As a result, the PTO driving force is switched to a high / low two-stage.

According to the above configuration, the engine 5 mounted on the traveling machine body 2, the transmission case 11 to which power is transmitted from the engine 5, and at least two

lever members

39 and 40 that are manually operated are provided. In the work vehicle 1, the group of

lever members

39, 40 are pivotally supported on a common pivot support shaft 72 so that the

lever members

39, 40 can be rotated. The rotation support shaft 72 can be used. Therefore, there is an effect that the number of parts can be reduced and the number of assembly steps can be reduced.

The

lever members

39 and 40 are formed of common parts, and the

lever members

79 and 80 are fitted on the pivot shaft 72 by fitting the

boss portions

79 and 80 provided on the base end sides of the

lever members

39 and 40, respectively. Since the 39 and 40 groups are arranged side by side, the

lever members

39 and 40 can be shared, and the effect of contributing to cost reduction can be achieved. It is possible to reduce the labor of assembling work when manufacturing the work vehicle 1. In addition, there is an advantage that the

lever members

39 and 40 can be easily set and retrofitted.

Furthermore, since the rotation support shaft 72 is detachably bolted to the side surface 71a of the support bracket 71 that supports the control seat 17 from below, the rotation support shaft 72 can be easily removed. For this reason, for example, it is possible to easily perform grease replacement or replacement (good maintenance workability).

In particular, in the embodiment, the lever member group is configured to change the drive system of the PTO shift lever 40 for shifting the output to the work machine mounted on the traveling machine body 2 and the traveling machine body 2 to the four-wheel drive and the four-wheel drive. And the

levers

39 and 40 are arranged in a posture projecting forward below the control seat 17 and on the left and right outside of the control seat 17. The two

levers

39 and 40, which are less frequently operated than those directly related to traveling, such as the main transmission lever 41, are placed as close to the control seat 17 as possible but not so much in the way. Therefore, it is effective in view of the operation efficiency of the operator. It is also possible to operate the

levers

39 and 40 with feet when the operator cannot release the hand.

Next, the support structure of the control seat 17 will be described with reference to FIGS. As shown in FIG. 9, the control seat 17 is supported by an adjusting device 114 composed of a plurality of members, and the adjusting device 114 is attached to a seat rail 115 that is longitudinally open and has an upwardly open groove shape so as to be movable back and forth. Therefore, the front and rear positions of the control seat 17 can be adjusted. It is also possible for the adjusting device 114 to have a height adjusting function.

The seat rail 115 constitutes a part of the seat bracket 116. For example, as can be easily understood from FIG. 10B, the seat bracket 116 includes left and right main supports 117 in the longitudinal direction in addition to the seat rail 115. The main support 117 includes a vertically oriented board 117a, left and right outwardly facing upper horizontal plates 117b provided at its upper end, and inward and outwardly facing lower horizontal parts 117c formed at the lower end of the board 117a. The lower horizontal portion 117c is fixed to the upper surfaces of the transmission case 11 and the rear housing 217 with bolts.

The rear end portions of the upper horizontal plate 117b in the left and right main supports 117 are connected by a channel-shaped rear stay 117d that opens upward. In addition, a tank receiving portion 117e is provided so as to protrude upward at the rear end portion of the upper horizontal plate 117b in the left and right main supports 117. It is also possible to provide a buffering function by attaching a soft material such as rubber to the tank receiving portion 117e. The rear stay 117d is positioned in front of the rear end of the main support 117. Therefore, the tank receiving portion 117e is generally overhanging behind the rear stay 117d.

The upper surfaces of the left and right main supports 117 are connected by two upper and lower upper stays 119, and the seat rail 115 is fixed to the upper surface of the upper stay 119. Moreover, the board | substrate 117a of the right-and-left main support 117 is connected with the middle stage stay 120 made from a round pipe. The middle stay 120 penetrates the main support 117 and the left and right ends protrude outside the main support 117. The left and right ends of the middle stay 120 are provided with reinforcing bars 122 that are tilted backward as viewed from the side via joint members 121. The upper portion of the reinforcing bar 122 is fixed to the lops frame 22 via

auxiliary frame members

123 and 124.

A lower stay 125 protruding to the left of the main support 117 is fixed to a portion of the left main support 117 below the middle stay 120. The lower stay 125 has a U-shaped shape with a downward opening, but a round pipe or a square pipe may be used. In the present embodiment, the main bracket 117, the seat rail 115, and the

stays

19, 20, and 25 at each stage mainly constitute the seat bracket 116. Of course, various forms such as adding another member as the seat bracket 116 or changing the connecting structure of the left and right main supports 117 can be adopted.

For example, as can be understood from FIGS. 8 and 9, the fuel tank 21 is disposed so as to surround the rear surface and the left side surface of the control seat 17. That is, the fuel tank 21 has a back portion 126a located on the rear side of the seat 12 and a side portion 126b located on the left side of the control seat 17, and is formed in a substantially L shape in plan view, and the left end portion of the back portion 36a. Is provided with an inlet that can be opened and closed by a lid 127. Further, the side portion 126 b in the fuel tank 21 is in a state of being stepped down from the upper surface of the back portion 126 a in the control seat 17.

The traveling body 2 is provided with a vehicle body cover 128 having an operation floor 128a on which an operator is placed. A mat 129 is stretched on the upper surface of the control floor 128a. In FIG. 8, the mat 129 is drawn below the control floor 128a, but actually, the mat 129 is placed on the upper surface of the control floor 128a.

As shown in FIG. 8, the vehicle body cover 128 is made of resin, and has a left side portion 128b and a right side portion 128c located on the left and right outer sides of the control seat 17. Therefore, the vehicle body cover 128 has a generally U-shaped form. The sub-control valve lever 44 is exposed upward from the right side portion 128c of the vehicle body cover 128, and the front and rear concave portions 131 are provided in the left side portion 128b. A plastic bottle and accessories can be stored in the recess 131. The side portion 126b of the fuel tank 21 is covered from above with the left side portion 128b of the vehicle body cover 128 (the left side portion 128b of the vehicle body cover 128 is supported by the side portion 126b of the fuel tank 21).

Next, details (particularly the mounting structure) of the fuel tank 21 will be described. The fuel tank 21 is manufactured by blow molding using resin as a raw material. As described with reference to FIG. 10B, left and right tank receiving portions 117e are formed at the rear end portions of the left and right main supports 117 constituting the seat bracket 116, for example, as shown in FIG. As described above, the left and right tank receivers 117e support the back portion 126a of the fuel tank 21 from below.

In this case, as can be easily understood from FIG. 12A, a downward stopper portion 34 located between the left and right main supports 117 is formed at the lower end of the back portion 126a of the fuel tank 21, and the downward stopper portion 34 is By fitting between the left and right tank receiving portions 117e, the fuel tank 21 is held so as not to be displaced in the left-right direction.

As shown in FIG. 11A, the side portion 126b of the fuel tank 21 protrudes downward from the back portion 126a. 12A, the front end portion of the side portion 126b in the fuel tank 21 is supported by the lower stay 125 that constitutes the seat bracket 116. Therefore, the fuel tank 21 is supported in a three-point support state, and the stability is very high. For this reason, although the fuel tank 21 is a large blow molded product, stress concentration can be prevented and high durability can be ensured.

As shown in FIG. 12A, at the front end of the side portion 126b constituting the fuel tank 21, as an example of a positioning stopper means, a step portion 132 with which the middle stay 120 can abut from above is formed. When the middle stay 120 hits the step 132, the front portion of the fuel tank 21 is prevented from moving upward and moving forward. In other words, the middle stay 120 is used as both the upward movement prevention stopper and the forward movement prevention stopper of the fuel tank 21. Forward movement is also prevented at the lower end surface of the side portion 126b of the fuel tank 21 by a rib (flange) 133 adjacent to the rear surface of the lower stay 125.

On the other hand, as can be understood from FIG. 11 (A), the stopper portion 34 provided at the lower end of the back portion 126a in the fuel tank 21 is in contact with or close to the rear stay 117d from behind, and this also causes the fuel tank 21 to face forward. Movement is blocked. That is, the fuel tank 21 is prevented from shifting left and right and moving forward by the stopper portion 34 provided at the lower end of the back portion 126a.

As shown in FIG. 12B, a back frame 135 extending along the back surface of the fuel tank 21 is fixed to the rear end of the right main support 117 via a bracket plate 136. The back surface of the fuel tank 21 is bent in a rearward convex shape in a side view, and the back frame 135 is bent in a dogleg shape in a side view. The fuel tank 21 is held by the back frame 135 so as not to move backward.

A pressing plate 137 is fixed to the upper end of the back frame 135 so as to overlap the back portion 126a of the fuel tank 21 from above, whereby the rear portion of the fuel tank 21 is held immovably upward. Further, a rearward stopper portion 138 that protrudes rearward on the left side of the back frame 135 is formed on the back surface of the fuel tank 21, and the fuel tank 21 is brought into contact with or close to the right side surface of the rearward stopper portion 138. Prevents rightward movement.

As shown in FIG. 12B, a stopper plate 139 is fixed to the rear end of the left main support 117 so as to overlap the back surface of the fuel tank 21. The stopper plate 139 is in a rearward inclined posture in a side view so as to overlap the back surface of the fuel tank 21 and has an upper end bent upward. A recess 140 into which the upper end portion of the stopper plate 139 enters is formed on the back surface of the fuel tank 21. The presence of the stopper plate 139 prevents the fuel tank 21 from moving backwards more accurately.

As described above, the fuel tank 21 is supported in a three-point support state by the main support 117 and the lower stay 125 constituting the seat bracket 116, and thus high stability is ensured. Further, since the seat bracket 116, the control seat 17 and the fuel tank 21 are configured as one unit, when assembling the traveling aircraft body 2, the seat bracket 116 is fixed to the transmission case 11 and the rear housing 217 for control. Assembling of the seat 17 and the fuel tank 21 is also performed, so that the assembly workability is excellent.

The assembly of the fuel tank 21 to the seat bracket 116 is performed according to the following procedure. That is, first, the fuel tank 21 is placed on the seat bracket 116 while being slightly shifted from the predetermined position, and then the fuel tank 21 is pushed forward to define the forward position. In this state, the middle stay 120 is fitted into the step 132 of the side portion 126b of the fuel tank 21, and the downward stopper 34 is inserted between the left and right tank receiving portions 117e. Thus, the fuel tank 21 is positioned so as to prevent forward movement and left-right movement, and the front stage is also prevented from being lifted by the middle stay 120.

Next, the back frame 135 is attached to the right main support 117 and the stopper plate 139 is attached to the left main support 117. As a result, the fuel tank 21 is prevented from moving backward and the rear part is prevented from floating. Therefore, the fuel tank 21 is held stably and non-displaceable by the seat bracket 116 without being fixed by fasteners such as bolts or bands. It is possible to form a flange in the fuel tank 21 and fix the flange to an appropriate member of the seat bracket 116 with a bolt or the like. It will be even more certain.

The oil supply unit 146 will be described with reference to FIG. For example, as shown in FIG. 13, the outlet port 142 of the fuel tank 21 is provided at the lower left end of the side portion 126b. In the vicinity of the outlet port 142, an oil supply unit 146 formed by attaching the fuel filter 143 and the fuel feed pump 144 to the auxiliary bracket 145 is disposed. The auxiliary bracket 145 is fixed to a rib 147 provided on the side portion 126b of the fuel tank 21 with bolts and nuts. Reference numeral 148 indicates a fuel pipe.

Since the oil feeding unit 146 is integrally attached to the fuel tank 21 in this way, the fuel filter 143 and the fuel feed pump 144 are also integrated with the fuel tank 21. Therefore, the traveling machine body 2 is assembled. Improves.

As shown in FIG. 11 (B), the auxiliary bracket 145 extends backward in a bottom view (or a plan view), and the fuel filter 143 and the fuel feed pump 144 are located between the auxiliary bracket 145 and the lops frame 22. is doing. The auxiliary bracket 145 is formed with a back surface portion 145a that covers the fuel filter 143 and the fuel feed pump 144 from behind.

The fuel filter 143 and the fuel feed pump 144 are surrounded by the fuel tank 21, the auxiliary bracket 145, and the lops frame 22. Therefore, it is possible to prevent the object from hitting from the side and to improve safety. It can be improved. The member denoted by reference numeral 118 in FIG. 11B is an upper gear box fixed to the upper surface of the rear housing 217 shown in FIG. 8 and the like, and the upper gear box 118 is a left and right member constituting the seat bracket 116. The main support 117 is disposed.

Further, as can be understood from FIG. 12B, the oil feeding unit 146 is also protected by the main support 117 constituting the seat bracket 116, and the mission case 11 exists under the main support 117. For example, the mission case 11 prevents the pebbles from jumping up and hitting the oil feeding unit 146. The lops frame 22 is formed in a hollow square shape.

Now, conventionally, for example, as schematically shown in FIG. 14, the fuel tank 21 ′ has been arranged below the control floor. On the other hand, a dozer 151 may be attached to the traveling machine body 2 by an arm 152 so as to be rotatable up and down. A pivot fulcrum of the arm 152 includes a pin 153. Then, in the earth pushing work by the dozer 151, the traveling machine body 2 receives a reaction force such that the front part thereof is raised upward. For this reason, conventionally, a balance weight is provided at the front end of the traveling machine body 2 to maintain the weight balance.

On the other hand, in the present embodiment, since the fuel tank 21 is arranged at the rear part of the traveling machine body 2, the center of gravity of the traveling machine body 2 moves rearward than before, so the pivot fulcrum 53 of the arm 152 moves rearward than before. By doing so, it is possible to prevent the front wheel 3 from floating while ensuring the grounding resistance of the rear wheel 4.

That is, in order to prevent the front wheel 3 from floating, it is effective to shift the pivot fulcrum of the arm 152 as far back as possible. However, in the arrangement structure of the conventional fuel tank 126 ′, the pivot center of the arm 152 is rearward. If it is shifted, the grounding resistance of the rear wheel 4 becomes small and the rear wheel may be idle. On the other hand, in the present embodiment, the center of gravity of the traveling machine body 2 is shifted backward by increasing the capacity of the fuel tank 21 as far as possible, so that the front wheel 3 floats while preventing the rear wheel 4 from idling. Can be prevented.

The traveling machine body 2 has a long-cylindrical transmission case 11 (base) as a structural material (strength member). The engine body of the engine 5 is connected to the front end surface of the transmission case 11 via a clutch housing 10. (Cylinder block) 211 is fixed. Engine frames 8 are fixed to the left and right side surfaces of the engine body 211. A front wheel drive unit 213 is fixed to the lower surface of the engine frame 8, and the front axle case 7 is fixed to the left and right ends of the front wheel drive unit 213. A clutch housing 8 is fixed to the front end surface of the transmission case 11, and a rear housing 217 is fixed to the rear end surface of the transmission case 11. A square rear axle case 19 is fixed to the left and right side surfaces of the rear housing 217.

The power generated by the engine 5 enters the transmission case 11 and is shifted, and the shifted power is transmitted to the front wheels 3 and the rear wheels so that the traveling machine body 2 travels. A part of the power of the engine 5 is transmitted to the work machine via the PTO shaft. This power flow will be described with reference to FIG.

The main clutch 9 for power disconnection is built in the clutch housing 8, and the movable clutch body constituting the main clutch 9 is attached to the output shaft of the engine 5. Inside the mission case 11, a forward / reverse switching mechanism 51 that switches the power of the engine 5 in the forward or reverse direction, a mechanical main transmission mechanism 52 that changes the rotational power via the forward / backward switching mechanism 51, and a sub-shift. A mechanism 53 is arranged.

The rear housing 217 includes a PTO transmission mechanism 54 that appropriately changes the power of the engine 5 and transmits it to the PTO shaft 29, and a differential gear mechanism 55 that transmits the rotational power via the auxiliary transmission mechanism 53 to the left and right rear wheels 4. And are arranged. In a cover case 56 (see FIG. 17) provided on the lower surface side of the mission case 11, a two-wheel drive / four-wheel drive switching mechanism 57 for switching the driving method of the traveling machine body 2 between two-wheel drive and four-wheel drive is disposed. .

A flywheel 59 is fixed to the engine output shaft 58 of the engine 5, and the flywheel 59 and a main driving shaft 60 extending rearward from the flywheel 59 are motively connected via a main clutch 9. A cylindrical input shaft 61 is rotatably fitted to the main driving shaft 60, and the cylindrical input shaft 61 and the flywheel 59 are also connected via the main clutch 9.

The power of the engine 5 is a PTO shaft drive system that reaches the PTO shaft via the main driving shaft 60 and the driven shaft 60 ', and a traveling system that reaches the

wheels

3 and 4 via the input cylinder shaft 32 and the output cylinder shaft 61'. It is branched and transmitted to two systems. The rotational power transmitted to the main shaft 60 is transmitted to the work drive shaft 224 ′ via the work clutch 224 ″, and then transmitted to the PTO transmission mechanism 54 and transmitted to the PTO shaft 29.

In addition, the rotational power transmitted to the cylindrical input shaft 61 passes through the forward / reverse switching mechanism 51, is then appropriately shifted by the main transmission mechanism 52 and the auxiliary transmission mechanism 53, and is transmitted to the cylindrical output shaft 32 '. The power of the cylindrical output shaft 32 ′ is transmitted to the left and right rear wheels 4 via the differential gear mechanism 55. Shift power by the main transmission mechanism 52 and the sub transmission mechanism 53 is also transmitted to the left and right front wheels 3 via the two-wheel drive / four-wheel drive switching mechanism 57 and the differential gear mechanism 62 in the front axle case 7.

By operating the forward / reverse switching lever 32 to slide the forward / reverse switching clutch 63 along the input cylinder shaft 32, the rotational power from the engine 5 toward the main transmission mechanism 52 is transmitted in the forward direction or in the reverse direction. Whether to transmit is selected. The main transmission mechanism 52 is switched to a plurality of stages (four stages in the embodiment) by operating the main transmission lever 41 (see FIGS. 2 and 17).

The sub-transmission mechanism 53 is switched between two steps of high and low by operating the sub-transmission lever 38. By operating the drive switching lever 39, the drive switching clutch 65 is slid along the front wheel propulsion shaft 64 that constitutes the two-wheel-drive / four-wheel-drive switching mechanism 57, whereby rotational power via the auxiliary transmission mechanism 34 is transferred to the front wheels 3. Whether or not to transmit is selected. Further, by operating the PTO speed change lever 40, the PTO speed change clutch 66 is slid along the PTO shaft 29, whereby the PTO driving force is switched between two levels.

The forward / reverse switching mechanism 51 and the main speed change mechanism 52 have a first power transmission shaft 240 that extends in parallel with the main drive shaft 60 and the cylindrical input shaft 61. The cylindrical input shaft 61 is provided with first to seventh gears 241 to 247 in order from a portion close to the engine 5, while the first power transmission shaft 240 is in order from the portion close to the engine 5. The eighth to thirteenth gears 248 to 253 are attached. Although details are omitted, the tenth to thirteenth gears 250 to 253 are slidable, and the main gear shift is performed by sliding them.

The auxiliary transmission mechanism 53 has a second power transmission shaft 254, and the 14th to 16th gears 255 to 257 are attached to the second power transmission shaft 254. Power is transmitted from the second power transmission shaft 254 to the two-wheel drive / four-wheel drive switching mechanism 57 via the seventeenth gear 258 and the eighteenth gear 259.

And in this embodiment, the 1st power transmission shaft 240 which comprises a part of forward / reverse switching mechanism 51 and the main transmission mechanism 52 is comprised with the compound transmission shaft. A specific structure centering on this point will be described.

For example, as shown in FIG. 19, the first power transmission shaft 240 includes a front unit shaft 260 to which the eighth gear 248 and the ninth gear 249 are fixed, and a rear side to which the tenth to thirteenth gears 250 to 253 are attached. The unit shaft 261 is composed of two unit axes. A small-diameter engaging portion 262 is formed at the rear end of the front unit shaft 260, while an engagement hole 263 is formed in the front end surface of the rear unit shaft 261 so that the small-diameter engaging portion 262 can be relatively rotated. For this reason, the front unit shaft 260 and the rear unit shaft 261 rotate together. As means for holding both

unit shafts

60 and 61 so as not to rotate relative to each other, the small-diameter engaging portion 262 and the engaging hole 263 are formed in a non-circular shape such as a square hole, or engaged by a key and a key groove. Various means can be employed, such as fixing with screws penetrating both, or spline fitting them together.

The front end of the front unit shaft 260 is pivotally supported by the front bearing body 265 via a front bearing 264, and the front end of the rear unit shaft 261 is supported by an intermediate bearing 267 of the transmission case 11 via an intermediate bearing 266. Further, the rear end portion of the rear unit shaft 261 is rotatably supported on the rear bearing body 269 via the rear bearing 268. The front bearing body 265 is fastened with a bolt to a step portion 270 provided inside the mission case 11 (see also FIG. 18C), and the rear bearing body 269 is fastened to the rear surface of the mission case 11 with a bolt. (See also FIG. 18B).

The front unit shaft 260 is formed with a rear flange 271 that prevents the ninth gear 249 from moving forward, and a front flange 272 that prevents the eighth gear 248 from moving backward. The reverse movement of the ninth gear 249 is blocked by the intermediate bearing 266, and the forward movement of the eighth gear 248 is blocked by the front bearing 264. Therefore, the eighth gear 248 and the ninth gear 249 are held so as not to move back and forth without requiring a stopper such as a snap ring.

Further, although the first power transmission shaft 240 is long in the front-rear direction, the midway portion in the front-rear direction is pivotally supported by the intermediate bearing portion 267 of the mission case 11 and thus has excellent support strength. Furthermore, since the front unit shaft 260 and the rear unit shaft 261 are unitized independently, assembly and removal can be performed separately, and therefore, the labor of assembly and maintenance can be saved. The cylindrical input shaft 61 is also supported by the front bearing body 265, the intermediate bearing portion 267, and the rear bearing body 269, and the second power transmission shaft 254 is supported by the intermediate bearing portion 66 and the rear bearing body 269. Has been.

FIG. 21 shows the operation mechanism of the drive switching clutch 65. The movable clutch body constituting the drive switching clutch 65 is rotatably attached to the rear end of the sleeve 273 fitted on the cylindrical input shaft 61, and the drive switching clutch 65 is disconnected by sliding the sleeve 273. To do. The sleeve 273 slides but does not rotate. Therefore, the sleeve 273 is fitted to the cylindrical input shaft 61 so as to be relatively rotatable and slidable. In addition, the movable clutch body is fitted to the cylindrical input shaft 61 so as to be slidable and relatively non-rotatable, whereby the cylindrical input shaft 61 is powered off.

Further, a U-shaped yoke (operating body) 274 with a downward opening in front view is fitted onto the sleeve 273 from above, and the tip of the arm portion 274a of the yoke 274 is between the front and rear protrusions 275 formed on the side surface of the sleeve 273. It fits in. The yoke 274 has a cylindrical portion 274b extending in a direction perpendicular to the axis of the sleeve 273. The operating shaft 276 is fixed to the cylindrical portion 274b, and the operating arm 277 is fixed to the tip of the operating shaft 276. . As shown in FIG. 17, the operation shaft 276 protrudes outward from the side surface of the mission case 11, and the operation arm 277 is fixed to the operation shaft 276 outside the mission case 11. The operation arm 277 is interlocked with a lever that is operated manually.

When the yoke 274 is rotated, the sleeve 273 slides and the drive switching clutch 65 is engaged, but the lower end portion of the arm portion 274a in the yoke 274 is circular in a side view, so that the protrusion 75 of the sleeve 273 is formed. It touches smoothly. In this embodiment, since the lower end of the yoke 274 is located between the front and rear protrusions 65, the sleeve 273 slides even if the yoke 274 is rotated in any direction. For this reason, a return spring is not required, and the structure is simplified accordingly. It is also possible to attach a roller (roller) to the tip of the arm part 274a in the yoke 274 and interpose the roller between the front and rear protrusions 275. In this case, the movement becomes smoother.

In this embodiment, the rear wheel support structure is also devised. This point will be described with reference to FIG. As described above, the rear axle case 19 is fixed to the left and right side surfaces of the rear housing 217. A rear axle 278 is rotatably supported inside the rear axle case 19 via a bearing 279. A disk 280 is fixed to the tip of the rear axle 278, and the rear wheel 4 is fixed to the disk via a rim.

The rear axle 278 enters the rear axle case 19 with the outer diameter being reduced from the portion exposed to the outside of the rear axle case 19, and thus has a step 281. In this embodiment, a fillet is attached to the stepped portion 281 to form a round shape, thereby preventing stress concentration, and a spacer (spacer, collar) 82 is interposed in the stepped portion 281 to provide a fillet. The bearing 279 is fitted without being obstructed. A cover plate 283 is fixed to the end surface of the rear wheel support case 218, and an oil seal 284 is disposed inside the cover plate 283.

In the example shown in FIG. 22C, the spacer 282 has a cross-sectional shape in close contact with the fillet, and in the example shown in FIG. 22D, it has an L-shaped cross-sectional shape with a space between the fillet, In the example shown in FIG. 22 (E), the step portion 281 is formed in two steps to form small rounds (fillets) at the corner portions, and the spacer 282 is formed in a flat plate shape. Further, in the example shown in FIG. 22F, a spacer portion 284a is formed in the oil seal 284.

As mentioned above, although embodiment of this invention was described, this invention can be embodied variously. For example, the mission case does not necessarily have to constitute the chassis of the traveling aircraft. The composite transmission shaft may be composed of three or more unit shafts. Furthermore, not only the first power transmission shaft but also other power transmission shafts can be configured as composite transmission shafts.

Next, the detailed structure inside the bonnet 14 will be described with reference to FIGS. As can be understood from FIG. 23 (A), the engine 5 is disposed in the rear half of the engine room, and a resin fan shroud 317 is disposed in front of the engine 5. The fan shroud 317 has a substantially square shape when viewed from the front, and a radiator 318 is fitted into the fan shroud 317 from the front side. The fan shroud 317 has a ventilation hole 321 into which the cooling fan 319 is loosely fitted. A radiator hose 318a passes through an upper portion and a lower portion of the fan shroud 317. Needless to say, the fan 319 is driven by the engine 5.

Hereinafter, the details of the part centering on the fan shroud 317 will be described. As can be understood from FIGS. 23A and 23B, the fan shroud 317 is fixed to the front floor plate 313 of the engine room. The fan shroud 317 is roughly sized to divide the engine room back and forth, and an edge member 322 is fixed to the outer peripheral surface. The bonnet 14 can be supported by the edge member 322. An air cleaner 323 is attached to the upper end of the front portion of the fan shroud 317. The fan shroud 317 has a cutout hole 323 ′ in which the suction hose is fitted at the upper left corner.

The fan shroud 317 has a substrate 324 having a partitioning function and a peripheral wall 325 that is integrally continuous with the upper end surface and the left and right end surfaces thereof. The peripheral wall 325 protrudes from both the front and rear sides of the substrate 324, and the radiator 318 is stored inside the peripheral wall 325. The radiator 318 has the same structure as that of the prior art, and includes an upper tank 326 and a lower tank 327 and a large number of thin tubes (not shown) connecting the two, as can be understood from FIG. The capillary tube group is covered with a filter 328.

As shown in FIG. 24 (A), the substrate 324 of the fan shroud 317 has a trapezoidal shape that bulges backward and has a large number of reinforcing ribs. A reservoir tank 329 is attached to a portion of the back surface of the substrate 324 near the upper left corner (below the cutout hole 323 ′ into which the intake hose is fitted). An inlet 330 is provided at the upper end of the reservoir tank 329, and an outlet 331 is provided at the lower end of the reservoir tank 329. A cap 332 is attached to the injection port 330 (the cap 332 has an air bleeding function). The discharge port 331 is connected to the upper tank 326 of the radiator 318 by a pipe.

As shown in FIG. 24 (B), a male engagement portion 333 having a reverse trapezoidal shape when viewed from the front is provided on the front surface of the reservoir tank 329, while a male engagement portion 333 is provided on the fan shroud 317. A female engagement part (rib) 334 sandwiched from both the left and right sides, and a presser claw 335 that contacts the upper surface of the male engagement part 333 are provided. The presser claw 335 is bent and deformed in the front-rear direction by making a notch 336 in the substrate 324.

Accordingly, when the male engagement portion 333 is pushed between the left and right female engagement portions 334 against the elasticity of the presser claws 335, the male engagement portion 333 has an inverted trapezoidal shape and cannot move downward. In this state, it is held so that it cannot be moved upward by being pushed by the holding claw 335. When removing, the presser claw 335 is pushed against the elasticity to release the press of the reservoir tank 329, and then the reservoir tank 329 is moved upward and then pulled backward. The male engagement portion 333 and the female engagement portion 334 may adopt a dovetail groove method that only fits and detaches by a relative movement in the vertical direction and does not move in the front-rear direction.

Alternatively, the upper and lower longitudinal engaging grooves or ribs may be formed on the left and right side surfaces of the reservoir tank 329, while the substrate 324 may be formed with ribs or ribs that fit into the engaging grooves from behind. In any case, an upward movement preventing means such as the presser claw 335 is necessary. Further, the substrate 324 is provided with a claw for grasping the reservoir tank 329 from both the left and right sides, a stopper for preventing the drop, and a holding claw for preventing the upward movement, so that the reservoir tank 329 is not specially processed. Is also possible.

The reservoir tank 329 can be attached to any part of the fan shroud 317 as long as space permits. However, if the reservoir tank 329 is provided on the rear surface of the fan shroud 317 and in the vicinity of the upper corner portion as in this embodiment, a sufficient mounting space is secured. In addition, there is an advantage that water can be smoothly passed to the radiator 318.

In another example shown in FIG. 25, a hollow reservoir tank portion 329 ′ is formed in the fan shroud 317. The fan shroud 317 is manufactured by blow molding using a resin as a material. In (A) and (B), the left and right sides of the fan shroud 317 form a reservoir tank portion 329 ′, and the other side forms a fuel cooling portion 340. Only the upper part of the left or right side of the fan shroud 317 can be formed as the reservoir tank portion 329 ′. In addition, the reservoir tank portion 329 ′ and the fuel cooling portion 340 may have any shape such as a simple straight shape.

In the second alternative example shown in FIG. 25 (C), an annular fuel cooling part 340 is formed around the ventilation hole 321 and the outer part is used as a reservoir tank part 329 '. Needless to say, the fan shroud 317 may be formed with only the reservoir tank portion 329 ′ without forming the fuel cooling portion 340.

In the third alternative example shown in FIG. 25D, the reservoir tank 329 is provided with a cooling air rectification function, and the cooling air is guided by the reservoir tank 329. If comprised in this way, the engine 5 can be cooled efficiently. 25A to 25C and the configuration of FIG. 25D can be combined to provide a wind direction guide function to the reservoir tank portion 329 ′ formed integrally with the reservoir tank 329.

The present invention can be embodied in various ways other than the above-described embodiment. For example, the configuration and support structure of the control seat, the specific structure of the seat bracket, and the like can be arbitrarily designed as necessary. It is also possible to configure the seat bracket with a single part. The composite transmission shaft may be composed of three or more unit shafts. Furthermore, not only the first power transmission shaft but also other power transmission shafts can be configured as composite transmission shafts. For example, since the number of reservoir tanks is not necessarily one, a plurality of reservoir tanks can be attached to the fan shroud. The present invention can be applied not only to tractors but also to other work vehicles. Not only the traveling means and wheels of the traveling machine body but also a crawler system or a combined system of wheels and crawlers can be adopted. The configuration of each other part is not limited to the illustrated embodiment, and various modifications can be made without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 Tractor 2 Traveling machine body 3 Front wheel 4 Rear wheel 5 Engine 11 Mission case 17 Control seat 21 Fuel tank 22 Lops frame 114 Control seat adjustment device 115 Seat rail 116 Seat bracket 117 Main support 120 Middle stay 125 Lower stay 128 Body cover 128a Control floor 132 Stepped portion 134 Downward stopper portion 135 Back frame 137 Holding plate 138 Backward stopper portion 143 Fuel filter 144 Fuel feed pump 145 Auxiliary bracket

Claims

A work vehicle in which an operating seat on which an operator sits and a fuel tank that supplies fuel to the engine are arranged on a traveling machine body equipped with an engine,
The engine is arranged in front of the cockpit, while the cockpit is supported by a seat bracket, and the fuel tank is arranged behind the cockpit, laterally, or both. And is supported by the seat bracket,
Work vehicle.
The fuel tank is in a form located at least on the rear side of the control seat, and has or does not have a side portion located on either the left or right side of the control seat.
The work vehicle according to claim 1.
The pilot seat, fuel tank, and seat bracket have a unit structure,
The work vehicle according to claim 2.
A fuel filter and a fuel feed pump are attached to the auxiliary bracket, and the auxiliary bracket is attached to the fuel tank or the seat bracket.
The work vehicle according to claim 3.
The fuel filter and the fuel feed pump are surrounded by the fuel tank, the auxiliary bracket, and a lops frame in a substantially plan view.
The work vehicle according to claim 4.
A transmission case that transmits power from the engine, and at least two lever members that are manually operated;
The lever member group is pivotally supported on a common pivot shaft so as to be rotatable.
The work vehicle according to claim 2.
The lever member group is composed of common parts, and the lever member group is arranged side by side by fitting a boss portion provided on each base end side to the rotation support shaft.
The work vehicle according to claim 6.
The rotating support shaft is detachably bolted to the side surface of the support bracket that supports the control seat from below.
The work vehicle according to claim 7.
The lever member group includes a PTO speed change lever for shifting the output to the work machine mounted on the traveling machine body, and a drive for switching the driving system of the traveling machine body between the 2WD and the 4WD. It is a switching lever, and both levers are arranged in a posture protruding forward, below the control seat and on the left and right outside of the control seat.
The work vehicle according to claim 6.