JP2018062236A - Work vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a fuel tank structure which inhibits air entrainment while having a form in which fuel tanks are provided at left and right sides of a machine body, such as a transmission case, and a fuel supply pipe is connected to a lower part of one of the fuel tanks.SOLUTION: A work vehicle includes a first fuel tank 80L at one of left and right sides of a machine body and includes a second fuel tank 80R at the other side. A connection pipe 87 connecting the first fuel tank 80L with the second fuel tank 80R is formed at a bypass connection pipe route R having connection pipe parts 87a, 87b connected to a side surface of the first fuel tank 80L and arranged in a lateral direction and a connection pipe part 87c connected to a front surface of the second fuel tank 80R and arranged along a longitudinal direction. A lowest bottom part of the first fuel tank 80L is provided lower than a lower bottom part of the second fuel tank 80R. A first fuel tank 80L side first opening 88 is provided lower than a second fuel tank 80R side second opening 89 by a predetermined height L.SELECTED DRAWING: Figure 11

Description

  The present invention relates to a work vehicle such as an agricultural tractor, and more particularly to a fuel tank disposed on the left and right of a mission case.

  An agricultural tractor as an example of a work vehicle is provided on the left and right sides of a mission case as an airframe in order to increase the capacity of a fuel tank. By the way, there is a configuration in which the left and right fuel tanks are connected, the connection pipe is provided lower than the left and right fuel tank bottoms, and the supply pipe is connected by providing a supply port to the engine near the large-capacity fuel tank (Patent Document) 1).

Japanese Patent No. 5726540

  By the way, the structure of the fuel tank of Patent Document 1 has an effect of facilitating the fuel biased toward the fuel tank having a large capacity to reach the supply port by improving the position of the supply port in the communication pipe. It is possible to suppress the occurrence of so-called air biting in the fuel supply pipe caused by flowing into the large capacity side fuel tank.

  However, since the fuel supply pipe is composed of left and right connecting pipes, the liquid level condition of the communication pipe is more likely to fluctuate than the fuel tank liquid level on the tilted bottom side when tilting left and right, so that air biting cannot be avoided and improvements have been made. Cost.

  The present invention seeks to obtain a fuel tank configuration that eliminates the above-mentioned drawbacks and that has a configuration in which a fuel supply pipe is connected to the lower portion of one of the fuel tanks and that has less air biting.

  In order to solve the above problems, the present invention has taken the following technical means.

  The invention according to claim 1 includes a first fuel tank 80L on one of the left and right sides of the fuselage and a second fuel tank 80R on the other, and a connecting pipe that connects the first fuel tank 80L and the second fuel tank 80R. In the work vehicle including 87, the connecting pipe 87 is connected to the side face of the first fuel tank 80L and connected to the front face of the second fuel tank 80R and connected to the front face of the second fuel tank 80R. A bypass connecting pipe path R having a pipe part 87c was formed.

  According to a second aspect of the present invention, in the first aspect of the invention, the bottom portion of the first fuel tank 80L is provided lower than the bottom portion of the second fuel tank 80R, and the connecting pipe portion extends in the left-right direction. The first fuel tank 80L side first opening 88 connecting 87a is provided at a predetermined height L lower than the second fuel tank 80R side second opening 89 connecting the connecting pipe portion 87c along the front-rear direction.

  The invention according to claim 3 is the invention according to claim 1 or 2, wherein a fuel supply pipe 90 to the engine 4 is connected to the first fuel tank 80L.

  According to the first aspect of the present invention, the connecting pipe 87 that connects the first fuel tank 80L and the second fuel tank 80R so that the fuel can flow is connected to the connecting pipe portions 87a and 87b that face in the left-right direction and the front-rear direction. The second fuel tank 80R has the connecting pipe portion 87c and forms the bypass connecting pipe path R instead of arranging the left and right first fuel tanks 80L and the second fuel tank 80R directly side by side and connecting them to the shortest right and left. When the side is tilted downward, the presence of the bypass connection pipe path R causes the fuel flow from the first fuel tank 80L to the second fuel tank 80R to be stagnant in the bypass connection pipe path R. Inflow into 80R is suppressed.

  According to the second aspect of the present invention, in addition to the effect of the first aspect, the detour connection path R is formed even if the second fuel tank 80R side is lowered and the front side of the fuselage is raised, and the connection pipe is particularly oriented in the front-rear direction. Due to the presence of the portion 87c, it takes time for the fuel to flow into the second fuel tank 80R side, so that even if the instantaneous rise of the front side of the aircraft occurs, the flow of fuel into the second fuel tank 87R side can be reduced.

  According to the invention described in claim 3, in addition to the effects described in claims 1 and 2, it is difficult to engage with air when fuel is supplied to the engine 4.

It is a side view of a tractor. It is a diagram which shows the transmission mechanism of the transmission of a tractor. (A) is sectional drawing which shows especially the traveling system transmission mechanism of the transmission of a tractor, (B) is sectional drawing which shows especially the PTO system transmission mechanism of the transmission of a tractor. It is the partial side view which looked at the mission case of the tractor from the vehicle width direction left side. It is the partial side view which looked at the front mission case of the tractor from the vehicle width direction right side. It is the partial side view which looked at the front mission case of the tractor from the vehicle width direction left side. (A), (B), and (C) are the side view, rear view, and top view of the spacer case of a tractor. It is the partial side view which looked at the mission case and fuel tank of the tractor from the vehicle width direction left side. It is the fragmentary top view which looked at the transmission case, fuel tank, and battery of the tractor from the upper part. It is the partial bottom view which looked at the mission case, fuel tank, and battery of the tractor from the lower part. It is the partial bottom view which looked at the fuel tank and the connecting pipe from the lower part. It is the partial front view which looked at the mission case and fuel tank of the tractor from the front. It is the fragmentary perspective view which looked at the mission case and fuel tank of the tractor from diagonally left front. It is sectional drawing of a fuel tank.

  Embodiments according to the present invention will be described below in detail with reference to the drawings.

  A tractor 1 as a work vehicle according to the present embodiment shown in FIGS. 1 to 3 is a work vehicle such as an agricultural tractor that performs work on a farm field or the like while self-propelled by power generated by a power source. The tractor 1 includes a front wheel 2, a rear wheel 3, an engine 4 as a power source, and a transmission (transmission) 5. Among these, the front wheel 2 is mainly provided as a steering wheel, that is, a steering wheel. The rear wheel 3 is mainly provided as a driving wheel, that is, a driving wheel. Rotational power generated by the engine 4 mounted in the bonnet 6 at the front of the machine body can be transmitted to the rear wheel 3 by appropriately decelerating it with a transmission 5 (transmission). A driving force is generated by the rotational power. In addition, the transmission 5 can transmit the rotational power generated by the engine 4 to the front wheels 2 as necessary. In this case, the four wheels of the front wheels 2 and the rear wheels 3 serve as driving wheels. Generate driving force. That is, the transmission 5 can switch between two-wheel drive and four-wheel drive, and can reduce the rotational power of the engine 4 and transmit the reduced rotational power to the front wheels 2 and the rear wheels 3. Further, the tractor 1 is provided with a connecting device 7 to which a working machine such as a rotary (not shown) can be mounted at the rear of the machine body.

  The tractor 1 has a steering handle 11 erected from a dashboard 10 on the front side of the cockpit 8 and various operation pedals such as a clutch pedal, a brake pedal, and an accelerator pedal, a forward / reverse lever, a shift lever, etc. Various operation levers are arranged.

  FIG. 2 is a diagram showing the transmission mechanism 13 in the transmission case 12 of the transmission 5. The transmission 5 includes a transmission case 12 (see FIGS. 3 and 4) and a transmission mechanism 13 that is disposed in the transmission case 12 and transmits rotational power from the engine 4 to the rear wheels 3 and the like. The transmission mechanism 13 transmits the rotational power from the engine 4 to the front wheels 2, the rear wheels 3, and the work equipment attached to the machine body, and drives them with the rotational power from the engine 4.

  Specifically, the transmission mechanism 13 includes an input shaft 14, a forward / reverse switching mechanism 15, a Hi-Lo transmission mechanism 16, a main transmission mechanism 17, an auxiliary transmission mechanism 18, a 2WD / 4WD switching mechanism 19, and a PTO. (Power take-off) It is comprised including the drive mechanism 20 grade | etc.,. The transmission mechanism 13 transmits the rotational power generated by the engine 4 to the rear wheel 3 through the input shaft 14, the forward / reverse switching mechanism 15, the Hi-Lo transmission mechanism 16, the main transmission mechanism 17, and the auxiliary transmission mechanism 18 in order. be able to. In addition, the transmission mechanism 13 transmits the rotational power generated by the engine 4 to the input shaft 14, the forward / reverse switching mechanism 15, the Hi-Lo transmission mechanism 16, the main transmission mechanism 17, the auxiliary transmission mechanism 18, and the 2WD / 4WD switching mechanism 19. It can be transmitted to the front wheel 2 via the order. Further, the transmission mechanism 13 can transmit the rotational power generated by the engine 4 to the work machine via the input shaft 14 and the PTO drive mechanism 20 in this order.

  The input shaft 14 is coupled to the output shaft of the engine 4 and receives rotational power from the engine 4.

  The forward / reverse switching mechanism 15 can switch the rotational power transmitted from the engine 4 to forward rotation or backward rotation. The forward / reverse switching mechanism 15 includes a forward gear stage 15a, a reverse gear stage 15b, a reverse counter gear 15c, a forward hydraulic multi-plate clutch C1 in the form of a hydraulic multi-plate clutch, and a reverse hydraulic multi-plate clutch C2. The forward / reverse hydraulic multi-plate clutches C1, C2 can switch the power transmission path in the forward / reverse switching mechanism 15 by switching the engaged / released state. The forward / reverse switching mechanism 15 transmits the rotational power transmitted to the input shaft 14 according to the engaged / released state of the forward / reverse hydraulic multi-plate clutches C1 and C2 to the counter shaft 21 by changing the transmission path.

  When the forward hydraulic multi-plate clutch C1 is in the engaged state and the reverse hydraulic multi-plate clutch C2 is in the released state, the forward / reverse switching mechanism 15 converts the rotational power transmitted to the input shaft 14 to the forward gear 15a, forward It is transmitted to the countershaft 21 by forward rotation through the hydraulic multi-plate clutch C1. When the forward hydraulic multi-plate clutch C1 is in the released state and the reverse hydraulic multi-plate clutch C2 is in the engaged state, the forward / reverse switching mechanism 15 transmits the rotational power transmitted to the input shaft 14 to the reverse side gear stage 15b and the reverse gear. 15c, transmitted to the countershaft 21 by reverse rotation through the reverse hydraulic multi-plate clutch C2. Thereby, the forward / reverse switching mechanism 15 can switch the forward / backward movement of the tractor 1.

  The forward / reverse switching mechanism 15 also functions as a main clutch. When both the forward / reverse hydraulic multi-plate clutches C1 and C2 are released, a neutral state is established, and power is transmitted to the front wheels 2 and the rear wheels 3 side. Can be cut off. The forward / reverse switching mechanism 15 can switch between forward, reverse, and neutral by hydraulic control by operating an unillustrated forward / reverse switching lever by an operator, for example. Further, by depressing the clutch pedal, both the forward and reverse hydraulic multi-plate clutches C1 and C2 can be released.

  The Hi-Lo speed change mechanism 16 can change the rotational power transmitted from the engine 4 at a high speed stage or a low speed stage. The Hi-Lo transmission mechanism 16 includes a Hi (high speed) side gear stage 16a, a Lo (low speed) side gear stage 16b, a hydraulic multi-plate clutch (Hi (high speed) side clutch) C3, and a hydraulic multi-plate clutch (Lo (low speed) side). Clutch) C4. The hydraulic multi-plate clutches C3 and C4 can switch the power transmission path in the Hi-Lo transmission mechanism 16 by switching the engaged / released state. The Hi-Lo transmission mechanism 16 transmits the rotational power transmitted to the counter shaft 21 to the transmission shaft 22 by changing the transmission path in accordance with the engaged / released state of the hydraulic multi-plate clutches C3 and C4. When the hydraulic multi-plate clutch C3 is in the engaged state and the hydraulic multi-plate clutch C4 is in the released state, the Hi-Lo transmission mechanism 16 transmits the rotational power transmitted to the counter shaft 21 to the hydraulic multi-plate clutch C3, Hi side. The speed is changed via the gear stage 16a and transmitted to the transmission shaft 22.

  The Hi-Lo transmission mechanism 16 transmits the rotational power transmitted to the counter shaft 21 to the hydraulic multi-plate clutch C4, Lo side when the hydraulic multi-plate clutch C3 is in the released state and the hydraulic multi-plate clutch C4 is in the engaged state. The speed is changed via the gear stage 16 b and transmitted to the transmission shaft 22. As a result, the Hi-Lo transmission mechanism 16 can change the rotational power from the engine 4 at the transmission ratio of the Hi side gear stage 16a or the transmission ratio of the Lo (low speed) side gear stage 16b and transmit it to the subsequent stage. it can. The Hi-Lo speed change mechanism 16 switches between the Hi (high speed) side and the Lo (low speed) side by hydraulic control when an unillustrated Hi-Lo changeover switch (high / low speed change operation switch) is turned on / off by an operator, for example. The speed can be changed in one of two stages of high speed and low speed. Further, the Hi-Lo speed change mechanism 16 can change speed while the tractor 1 is traveling due to the above-described configuration.

  The main speed change mechanism 17 can change the rotational power transmitted from the engine 4 at any one of a plurality of shift speeds. The main speed change mechanism 17 is a synchromesh type speed change mechanism, and here, the rotational power transmitted from the engine 4 via the forward / reverse switching mechanism 15 and the Hi-Lo speed change mechanism 16 can be changed. The main speed change mechanism 17 includes a first speed gear stage 17a, a second speed gear stage 17b, a third speed gear stage 17c, a fourth speed gear stage 17d, a fifth speed gear stage 17e, and a sixth speed gear as a plurality of speed stages. A stage 17f is included. The main transmission mechanism 17 transmits the rotational power transmitted to the transmission shaft 22 according to the coupling state of the first speed gear stage 17a to the sixth speed gear stage 17f with the transmission shaft 22 from the first speed gear stage 17a to the first speed gear stage 17a. The speed is changed via one of the sixth speed gears 17f and transmitted to the transmission shaft 23. Thus, the main transmission mechanism 17 can shift the rotational power from the engine 4 at any gear ratio of the first speed gear stage 17a to the sixth speed gear stage 17f and transmit it to the subsequent stage. The main transmission mechanism 17 can select and switch one of a plurality of shift stages by operating a main shift operation lever (not shown) by an operator, for example. The speed can be changed at any one of the six speeds of the sixth speed gear stage 17f. Further, the main transmission mechanism 17 can change gears while the tractor 1 is traveling due to the above-described configuration.

  The auxiliary transmission mechanism 18 can change the rotational power transmitted from the engine 4 through the forward / reverse switching mechanism 15, the Hi-Lo transmission mechanism 16, and the main transmission mechanism 17 in order. The sub-transmission mechanism 18 includes a first sub-transmission 24, a second sub-transmission 25, and the like, and the rotational power transmitted to the transmission shaft 23 is transmitted to the first sub-transmission 24 and the second sub-transmission 25. And the like, and then transmitted to the transmission shaft 26. The first sub-transmission 24 can transmit the rotational power transmitted from the engine 4 and shifted by the main transmission mechanism 17 or the like at the high speed stage or the low speed stage and transmit it to the rear wheel 3 side that is the driving wheel. The second sub-transmission 25 shifts the rotational power transmitted from the engine 4 and shifted by the main transmission mechanism 17 or the like at an ultra-low speed lower than that of the first sub-transmission 24, and the rear wheel 3 is a driving wheel. Can be transmitted to the side. The second auxiliary transmission 25 is omitted when simplification of specifications is required.

  The first sub transmission 24 of the sub transmission mechanism 18 includes a first gear 24a, a second gear 24b, a third gear 24c, a fourth gear 24d, and a shifter 24e. The first gear 24a is coupled to the transmission shaft 23 so as to be integrally rotatable, and rotational power from the transmission shaft 23 is transmitted (input). The second gear 24b meshes with the first gear 24a. The third gear 24c is coupled to the second gear 24b so as to be integrally rotatable. The fourth gear 24d meshes with the third gear 24c. The shifter 24e switches the coupling state of the first gear 24a, the fourth gear 24d, and the transmission shaft 26. That is, a clutch pawl 26a provided integrally with the transmission shaft 26, a clutch pawl 24ac integral with the first gear 24a, and a clutch pawl 24dc integral with the fourth gear 24d are formed with the same diameter and the same number of teeth in an adjacent state. Power is transmitted from the first gear 2a to the transmission shaft 26 when the clutch pawl 26a and the clutch pawl 24ac are simultaneously engaged, and when the clutch pawl 26a and the clutch pawl 24dc are simultaneously engaged, In this configuration, power is transmitted to the transmission shaft 26. Each clutch pawl is arranged and configured to be shiftable to a position where the shifter 24e does not engage with either the clutch pawl 24ac or the clutch pawl 24dc.

  The shifter 24e has a Hi (high speed) side position where the first gear 24a and the transmission shaft 26 are coupled so as to be integrally rotatable, a Lo (low speed) side position where the fourth gear 24d and the transmission shaft 26 are coupled so as to be integrally rotatable, Neither the first gear 24a nor the fourth gear 24d is coupled to the transmission shaft 26 and can move to the neutral position (neutral position) to be released. The first sub-transmission 24 transmits the rotational power transmitted to the transmission shaft 23 to the transmission shaft 26 by switching the transmission path according to the position of the shifter 24e.

  The second subtransmission 25 of the subtransmission mechanism 18 includes a first gear 25a, a second gear 25b, a third gear 25c, a fourth gear 25d, and a shifter 25e. The first gear 25a is coupled to the fourth gear 24d of the first auxiliary transmission 24 so as to be integrally rotatable. The second gear 25b meshes with the first gear 25a. The third gear 25c is coupled to the second gear 25b so as to be integrally rotatable. The fourth gear 25d meshes with the third gear 25c. The shifter 25e switches the coupling state between the fourth gear 25d and the transmission shaft 26. That is, a clutch pawl 26b provided integrally with the transmission shaft 26 and a clutch pawl 25dc integral with the fourth gear 25d are formed in the same diameter and the same number of teeth and are arranged adjacent to each other, and the shifter 25e is disposed adjacent to the clutch pawl 26b. When the clutch pawls 25dc are simultaneously engaged, power is transmitted from the fourth gear 25d to the transmission shaft 26.

  The shifter 25e has an ultra-low (ultra-low speed) side position where the fourth gear 25d and the transmission shaft 26 are coupled so as to be integrally rotatable, and a neutral position (neutral position) where the fourth gear 25d and the transmission shaft 26 are not coupled and released. Position). In this case, the rotation of the transmission shaft 26 is governed by the position of the shifter 24 e of the first auxiliary transmission 24. The second sub-transmission 25 transmits the rotational power transmitted to the transmission shaft 23 to the transmission shaft 26 by switching the transmission path according to the position of the shifter 25e. When the first sub-transmission 24 is in the neutral state and the shifter 25e is in the super-Lo position, the second sub-transmission 25 uses the rotational power transmitted to the transmission shaft 23 as the first sub-transmission 24. From the first gear 24a, the second gear 24b, the third gear 24c, the fourth gear 24d, the first gear 25a, the second gear 25b, the third gear 25c, the fourth gear 25d, and the shifter 25e of the second auxiliary transmission 25 are connected. Are sequentially decelerated through and transmitted to the transmission shaft 26. As a result, the second auxiliary transmission 25 converts the rotational power from the engine 4 into the second gear 24b, the third gear 24c, the fourth gear 24d, the first gear 25a, the second gear 25b, the third gear 25c, The speed can be changed at a speed ratio on the super-Lo (super-low speed) side via the four gears 25d and transmitted to the subsequent stage. Further, when the shifter 25e is in the neutral position, the second auxiliary transmission 25 is in a state where the fourth gear 25d is idling with respect to the transmission shaft 26, that is, in a neutral state.

  Therefore, the subtransmission mechanism 18 combines the rotational power transmitted to the transmission shaft 23 with the first subtransmission 24 and the second subtransmission 25, so that of the three stages of high speed, low speed, and ultra-low speed. Either can be changed and transmitted to the transmission shaft 26.

  The transmission mechanism 13 of the transmission 5 transmits the rotational power transmitted to the transmission shaft 26 to the rear wheel 3 via the rear wheel differential 27, the rear axle 28, the planetary gear reduction mechanism 29 for deceleration, and the like. As a result, in the tractor 1, the rear wheel 3 is rotationally driven as a drive wheel by the rotational power from the engine 4.

  The 2WD / 4WD switching mechanism 19 includes hydraulic multi-plate clutches C6 and C7, and also functions as a front wheel speed increasing mechanism. The 2WD / 4WD switching mechanism 19 includes a transmission shaft 19a, a Hi (high speed) side gear stage 19b, a Lo (low speed) side gear stage 19c, a hydraulic multi-plate clutch (Lo (low speed) side clutch) C6, a hydraulic multi-plate clutch (Hi). (High speed) side clutch) C7 and transmission shaft 19d are included. The hydraulic multi-plate clutches C6 and C7 can switch the power transmission path in the 2WD / 4WD switching mechanism 19 by switching the engaged / released state. The 2WD / 4WD switching mechanism 19 transmits the rotational power transmitted to the transmission shaft 19a to the transmission shaft 19d by changing the transmission path according to the engaged / released state of the hydraulic multi-plate clutches C6 and C7. When the hydraulic multi-plate clutch C6 is in the engaged state and the hydraulic multi-plate clutch C7 is in the released state, the 2WD / 4WD switching mechanism 19 transmits the rotational power transmitted to the transmission shaft 19a to the Lo-side gear stage 19c, The speed is changed via the plate clutch C6 and transmitted to the transmission shaft 19d.

  The 2WD / 4WD switching mechanism 19 switches whether or not the rotational power transmitted to the transmission shaft 26 is transmitted to the front wheel 2 side. The 2WD / 4WD switching mechanism 19 includes a transmission shaft 19a, a Hi-side gear stage 19b, a Lo-side gear stage 19c, and a transmission shaft 19d. The transmission shaft 19a transmits (inputs) the rotational power from the transmission shaft 26 via the gear 30, the gear 31, the transmission shaft 32, the coupling 33, and the like. The transmission gear 19a is inserted into the first gear 19b, and the first gear 19b is assembled so as to be rotatable relative to the transmission shaft 19a.

  The transmission mechanism 13 of the transmission 5 includes a front wheel differential input shaft 19e, a front wheel differential 34, a front axle 35, a vertical axis 36, a planetary gear reduction mechanism 37, and the like that extend the rotational power transmitted to the transmission shaft 19d in the front-rear direction. Is transmitted to the front wheel 2 via. As a result, the tractor 1 can be driven by four-wheel drive, with the front wheels 2 and the rear wheels 3 being rotationally driven as drive wheels by the rotational power from the engine 4. In the 2WD / 4WD switching mechanism 19, the transmission of the rotational power transmitted to the transmission shaft 19a to the transmission shaft 19d side is interrupted by the hydraulic multi-plate clutches C6 and C7 being both released. As a result, the tractor 1 can travel by two-wheel drive.

  The PTO drive mechanism 20 drives the work machine with the power from the engine 4 by shifting the rotational power transmitted from the engine 4 and outputting it to the work machine from the PTO shaft 40 (see FIG. 2) at the rear of the machine body. It is. The PTO drive mechanism 20 includes a PTO clutch mechanism 38, a PTO transmission mechanism 39, a PTO shaft 40, and the like.

  The PTO clutch mechanism 38 switches between transmission and interruption of power to the PTO shaft 40 side. The PTO clutch mechanism 38 includes a gear 38a, a hydraulic multi-plate clutch C5, and a transmission shaft 38b. The gear 38a meshes with a gear 41 that is coupled to the input shaft 14 so as to be integrally rotatable. The hydraulic multi-plate clutch C5 switches the power transmission state between the gear 38a and the transmission shaft 38b by switching the engaged / released state. The PTO clutch mechanism 38 enters a PTO drive state in which power is transmitted to the PTO shaft 40 side when the hydraulic multi-plate clutch C5 is engaged, and the rotational power transmitted from the input shaft 14 to the gear 38a via the gear 41. Is transmitted to the transmission shaft 38b via the hydraulic multi-plate clutch C5. When the hydraulic multi-plate clutch C5 is released, the PTO clutch mechanism 38 is in a PTO non-driven state (neutral state) in which transmission of power to the PTO shaft 40 side is interrupted, and the rotational power transmitted to the gear 38a is reduced. Transmission to the transmission shaft 38b side is interrupted.

  The tractor 1 is provided with a gear pump 70 through a gear 70a meshing with the gear 38a, a gear 70b meshing with the gear 70a, and the like. The gear pump 70 applies hydraulic pressure to a hydraulic system such as the transmission mechanism 13.

  The PTO speed change mechanism 39 changes speed when power is transmitted to the PTO shaft 40 side. The PTO transmission mechanism 39 includes a Hi (high speed) side gear stage 39a, a Lo (low speed) side gear stage 39b, a transmission shaft 39c, and a shifter 39d. The PTO transmission mechanism 39 changes the rotational power transmitted to the transmission shaft 38b via the Hi side gear stage 39a or the Lo side gear stage 39b according to the position of the shifter 39d, and transmits it to the transmission shaft 39c. To do.

  The PTO shaft 40 is coupled to a work machine side input shaft (not shown) via a universal joint shaft (not shown), and transmits rotational power from the engine 4 to the work machine. Since the transmission shaft 39c is offset from the center of the machine body, the PTO shaft 40 is disposed at the center of the machine body so that it can be transmitted via the first gear 44, the second gear 45, and the like.

  The mission case 12 of the present embodiment is divided into a front mission case 12F on the front side in the front-rear direction and a rear mission case 12R on the rear side in the front-rear direction, as shown in FIGS. As shown in FIGS. 5 and 6, the front mission case 12 </ b> F of the present embodiment includes a clutch valve 55 for controlling the hydraulic multi-plate clutches C <b> 1 and C <b> 2 of the forward / reverse switching mechanism 15, and the Hi-Lo transmission mechanism 16. For controlling the clutch valve 56 for controlling the hydraulic multi-plate clutches C3 and C4, the clutch valve 57 for controlling the hydraulic multi-plate clutch C5 of the PTO clutch mechanism 38, and for controlling the hydraulic multi-plate clutches C6 and C7 of the 2WD / 4WD switching mechanism 19 The clutch valve 64, the gear pump 70, and the like are arranged separately on the left and right surfaces. Here, as shown in FIG. 5, the front mission case 12 </ b> F has a clutch valve 55, a clutch valve 56, and a clutch valve 64 disposed on the right side surface in the vehicle width direction. On the other hand, as shown in FIG. 6, the front mission case 12F is provided with a clutch valve 57 and a gear pump 70 on the left side in the vehicle width direction. As a result, the tractor 1 can efficiently arrange the clutch valves 55, 56, 57, 64, the gear pump 70, and the like on the outer surface of the front mission case 12F.

  Two case configurations of the front mission case 12R and the rear mission case 12R may be used, but in this embodiment, a spacer-like spacer case 12S is further sandwiched between these cases 12F and 12R (FIG. 3). 4). That is, the spacer case 12S is provided between the front mission case 12F and the rear mission case 12R of the transmission case 12 (FIG. 7), and the transmission shaft 22 and the transmission shaft 23 of the main transmission mechanism 17 are connected to the 2WD / 4WD switching mechanism 19. A metal portion 12Sa that supports the transmission shaft 32 is formed. With this configuration, the transmission shafts 22 and 23 and the transmission shaft 32 are supported by the metal portion 12Sa of the spacer case 12S between the front mission case 12F and the rear mission case 12R, so that the metal configuration on the front side of the rear mission case 12R is achieved. Can be omitted. The front transmission case 12F and the spacer case 12S are assembled so as to be connected, but the transmission shafts 22 and 23 and the transmission shaft 32 extending rearward in the front mission case 12F are handled relatively in terms of weight and size. These shafts can be pivotally supported on the metal part 12Sa while skillfully adjusting and aligning the easy spacer case 12S, and at the same time can be joined to the rear surface of the front transmission case 12F. As a result, the spacer case 12Sa is joined together with the assembly of the internal gear and shaft. Make it easy.

  In addition, the spacer case 12S is formed in a flange portion that is slightly wider than the left and right width of the front mission case 12F, and forms a dead space on the left and right side surfaces of the front mission case 12F. The control clutch valves 55, 56, 57 and 64 can be provided.

  Next, the gear pump 70 as the hydraulic pump and its peripheral configuration will be described. The gear pump 70 sucks up the hydraulic oil stored in the transmission case 12 by driving, and distributes and supplies the hydraulic oil to the hydraulic circuit for lifting and lowering the work implement and the hydraulic circuit for steering control. The front mission case 12F) is disposed on one side surface (left side in the illustrated example).

  Two suction filters 71, 71 are detachably provided on one side of the rear mission case 12 </ b> R on the same side (left side in the example) as the gear pump 70. Appropriate output sides of the filters 71 and 71 communicate with the gear pump 70 via a hose 76 and a pipe 77.

  As shown in FIGS. 9 to 14, the fuel tank 80 is made of resin and is manufactured by blow molding and arranged on the left and right sides of the mission case 12. The tank capacity of the left and right first fuel tank 80L is made larger than the capacity of the left and right second fuel tank 80R. Of these, the first tank support plate 81L that receives the bottom of the first fuel tank 80L is bolted and supported by the mounting plate 78S so that the rear side thereof is detachably attached to the transmission case 12, and the front side thereof is the belt plate 83. Thus, the floor panel portion of the safety frame structure and the floor panel portion of the cabin structure are suspended and supported by a vibration isolation support frame 82 that supports the transmission case 12 in an antivibration manner. The anti-vibration support frame 82 is detachably fixed to the side surface of the transmission case 12 (front transmission case 12F in the illustrated example) with a bolt.

  The front side support structure of the first fuel tank 80L will be described in detail. The belt plate 83 is simultaneously wound around the fuel tank 80L and the first tank support plate 81L and is suspended from the anti-vibration support frame 82. Is divided into a first belt plate 83a and a second belt plate 83b. One end of the first belt plate 83a is connected to the vibration-proof support plate 82, bypasses the tank support plate 81 from the outside of the first fuel tank 80L, The other end is connected to the second belt plate 83b and is supported by being suspended by these first and second belt plates 83a and 83b. Further, the first fuel tank 80L and the tank support plate 81L are fixed by the rear side band plate 85 immediately before the mounting plate 78S. The rear side belt plate 85 is connected to the mission case 12.

  Note that the first fuel tank 80L is formed by resin blow molding, the front side is the oil supply part 80a, the middle part is the wide left and right part, the rear part is a slanted part that is higher in the rear as viewed from the side, and slightly narrower part. And the shape of the first fuel tank 80L approaching the transmission case 12 side is molded so as not to interfere with each other when the gear pump 70 and the PTO control clutch valve 57 are attached to the transmission case 12, Therefore, the first fuel tank 80L surrounds the side of the PTO control clutch valve 57 and the gear pump 70, and protects them from collision with other objects. Further, the upper surfaces of the suction filters 71, 71 are surrounded and protected by the rear side 80b of the fuel tank 80.

  Next, a second tank support plate 81R that receives the bottom of the other second fuel tank 80R is supported on the transmission case 12 by a mounting plate 78S common to the first fuel tank 80L on the rear side, and the front portion Is supported by the transmission case 12 with a dedicated mounting plate 78F, and the second fuel tank 80R and the second tank support plate 81R are simultaneously wound and fixed to the transmission case 12 by the belt plate 86 immediately before the mounting plate 78S. doing.

  The arrangement relationship between the first fuel tank 80L and the second fuel tank 80R is such that at the front end of each tank, the first fuel tank 80L having a larger capacity exists in the front and the second fuel tank 80R having a smaller capacity exists in the rear. Each rear end portion has a relationship in which the rear end of the first fuel tank 80L is substantially in the same position as the rear end of the second fuel tank 80R.

  As described above, since the fuel filler port 80a is provided on the first fuel tank 80L side, the first fuel tank 80L and the second fuel tank 80R are connected by the resin connecting pipe 87. In other words, the connecting pipe 87 having one end connected to the front lower portion of the first fuel tank 80L is bent in the middle, and is provided so that the other end is connected to the front lower end of the second fuel tank 80R. It is formed in an L shape. More specifically, the connecting pipe 87 includes first to third connecting pipe portions 87a, 87b, 87c, and is formed in an L shape between the straight first connecting pipe portion 87a and the third connecting pipe portion 87c. The second connecting pipe 87b is fitted and connected to form an L shape in a plan view, and the end of the first connecting pipe portion 87a is formed with respect to the first opening 88 formed at the lower end inside the front portion of the first fuel tank 80L. The first connecting pipe portion 87a is connected so as to face in the left-right direction, and the third connecting pipe portion 87c is connected to the second opening 89 formed at the lower end of the front end of the second fuel tank 80R. It connects so that 87c may face front and back. At this time, the first opening 88 opens near the bottom of the first fuel tank 80L, and the second opening 89 opens near the bottom of the second fuel tank 80R. The bottom of the tank 80L and the bottom of the second fuel tank 80R are made different in height, and the first opening 88 of the first fuel tank 80L is located with respect to the second opening 89 of the second fuel tank 80R. It is provided lower by a predetermined height L. Further, the second connecting pipe portion 87b is bent toward an inclined portion gradually inclined from a fitting connecting portion with the first connecting pipe portion 87a and a connecting fitting portion with the third connecting pipe portion 87c. Forming part. The slope L earns the height L. The range of the inclined portion of the second connecting pipe portion 87b is inclined so as to bypass the lower portion of the front wheel differential input shaft 19e. This inclined portion facilitates the fuel movement to the first fuel tank 87L. it can.

  Next, with respect to the fuel supply pipe 90 to the engine 4, a supply opening 91 is formed at a rear position of the connecting pipe 87 connecting portion of the first fuel tank 80 </ b> L, and one end of the fuel supply pipe 90 is connected to the supply opening 91. Connected. The connection structure is a known structure in which an end of the fuel supply pipe 90 is fitted to a connection pipe 91a formed to protrude outward from the supply opening 91, and the outer periphery of the overlapping portion is fastened and fixed with a band. In the example shown in the figure, it extends toward the inside of the machine body, then bends forward and is further extended upward and connected to a feed pump (not shown). As shown in the cross-sectional view of FIG. 14, the supply opening 91 is formed at the lowest height position that can be formed so that the fuel at the bottom of the first fuel tank 80 </ b> L can be supplied with substantially no remaining amount.

  A return pipe 92 from the engine 4 is provided in the vicinity of the fuel supply pipe 90, and an end thereof is disposed on the front side of the connecting pipe 87. A return opening 93 of the return pipe 92 to the first fuel tank 80L is formed at a relatively low position of the first fuel tank 80L. Therefore, it is possible to prevent foaming that tends to occur due to reflux from a high place. Further, breather pipes 94L and 94R are connected to the upper surfaces of the rear portions of the first fuel tank 80L and the second fuel tank 80R, and are extended upward to be connected to the main body as appropriate.

  Based on FIG. 13, the fixing means for the first to third connecting pipe portions 87a, 87b, 87c of the connecting pipe 87 will be described. A bracket 96 for mounting the battery 95 is formed in the front space of the second fuel tank 80R, and a lower surface cover 97 is provided between the bracket 96 and the first tank support plate 81L of the first fuel tank 80L. The lower surface cover 97 corresponds to the first connection tube portion 87a and the second connection tube 87b of the connection tube 87, and the lower surface cover 97 is configured to hold the connection tube portion.

  The bracket 96 of the battery 95 includes a receiving plate 96a for receiving the battery 95, a support plate 96b for connecting the receiving plate 96a to the transmission case 12. A space portion is formed between the battery 95 and the mission case 12 side, and the third connecting pipe portion 87c is arranged and supported at this position.

  As described above, the connecting pipe 87 that connects the first fuel tank 80L on the left side and the second fuel tank 80R on the right side so that fuel can flow is provided in the left-right direction of the first connecting pipe part 87a and the second connecting pipe part 87b. And a portion facing in the front-rear direction extending from a part of the second connecting pipe portion 87b to the third connecting pipe portion 87c, and the left and right first fuel tanks 80L and the second fuel tank 80R are directly aligned and connected to the left and right shortest. Instead, the L-shaped bypass connecting pipe path R is formed in a plan view. Therefore, when the aircraft tilts counterclockwise when viewed from the front, the presence of the bypass connecting pipe path R causes the first fuel tank to The fuel flow from 80L to the second fuel tank 80R becomes stagnant in the detour connection pipe path R, and the inflow into the second fuel tank 80R is suppressed, and the subsequent reverse inclination (clockwise in front view) 1st fuel tank Flowing moved to click 80L side. As described above, since the first opening 88 of the first fuel tank 80L is lower than the second opening 89 of the second fuel tank 80R by the height L, the connecting portion is connected. The fuel in the pipe 87 will easily flow into the first fuel tank 87L. This is effective when the fuel supply pipe 90 and the return pipe 92 are connected to the first fuel tank 80L side.

  If the structure of the connecting pipe 87 is used, the detour connection path R is formed even if the right side of the fuselage is lowered and the front side of the fuselage is raised. In particular, the presence of the third connecting pipe portion 87c facing in the front-rear direction causes the second fuel Since it takes time for the fuel to flow into the tank 80R, it is possible to reduce the flow of fuel into the second fuel tank 87R even if an instantaneous rise of the aircraft front side occurs.

  A lower front portion of the first fuel tank 80L includes a bumper-like protective cover 98 supported by the mission case 12F.

4 Engine 80L 1st fuel tank 80R 2nd fuel tank 87 Connection pipe 87a 1st connection pipe part (connection pipe part)
87b Second connecting pipe part (connecting pipe part)
87c 3rd connecting pipe part (connecting pipe part)
88 First opening 89 Second opening 90 Fuel supply pipe L Height R Detour connection pipe path

Claims (3)

  A first fuel tank (80L) is provided on one of the left and right sides of the fuselage, and a second fuel tank (80R) is provided on the other side, and a connecting pipe (80L) is connected to the first fuel tank (80L) and the second fuel tank (80R). 87), the connecting pipe (87) is connected to the side surface of the first fuel tank (80L) and is connected to the side faces of the connecting pipe portions (87a, 87b) and the front side of the second fuel tank (80R). A work vehicle characterized in that it is formed in a detour connection pipe path (R) having a connection pipe part (87c) that is connected to the front and rear direction.   The bottom of the first fuel tank (80L) is lower than the bottom of the second fuel tank (80R), and the first fuel tank (80L) side connecting the connecting pipe portion (87a) along the left-right direction. The first opening (88) is provided at a predetermined height (L) lower than the second opening (89) on the second fuel tank (80R) side connecting the connecting pipe portion (87c) along the front-rear direction. The work vehicle according to 1.   The work vehicle according to claim 1 or 2, wherein a fuel supply pipe (90) to the engine (4) is connected to the first fuel tank (80L).

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