Work vehicle

Abstract

To suppress the occurrence of cavitation in a work vehicle when hydraulic oil in a reservoir is sucked into a hydraulic pump and supplied to a work device from the hydraulic pump.SOLUTION: A work vehicle is provided with a plurality of work devices, a first reservoir 11 capable of storing hydraulic oil, a second reservoir 12 capable of storing hydraulic oil, and a hydraulic pump that supplies hydraulic oil to the work devices. The second reservoir 12 is provided at a position higher than an upper end of the first reservoir 11. A connecting oil passage 16 is provided that connects the first reservoir 11 and the second reservoir 12 and allows hydraulic oil to communicate between them.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a configuration for supplying hydraulic oil to a work device installed in a work vehicle. [Background technology]

[0002] A sugarcane harvester, which is an example of a work vehicle, is disclosed in Patent Document 1. In Patent Document 1, the vehicle is equipped with multiple work devices such as a reaping unit and a transport device, and is configured so that hydraulic oil in a reservoir is drawn into a hydraulic pump and supplied from the hydraulic pump to the work devices, thereby operating the work devices. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2022-101186 A (see FIG. 6) Summary of the Invention [Problem to be solved by the invention]

[0004] In a configuration in which hydraulic oil in a reservoir is drawn into a hydraulic pump and supplied from the hydraulic pump to a working device, there is a concern that cavitation may occur. When the hydraulic pump draws hydraulic oil from the reservoir, the pressure of the hydraulic oil temporarily drops, causing air bubbles to form in the hydraulic oil. When the hydraulic pump increases the pressure of the hydraulic oil, the air bubbles burst, causing cavitation.

[0005] The present invention aims to suppress the occurrence of cavitation when hydraulic oil in a reservoir is drawn into a hydraulic pump in a work vehicle and supplied to a working device from the hydraulic pump. [Means for solving the problem]

[0006] The work vehicle of the present invention is provided with a plurality of working devices, a first storage section capable of storing hydraulic oil, a second storage section capable of storing hydraulic oil, and a hydraulic pump that supplies hydraulic oil to the working devices, and the second storage section is provided at a position higher than the upper end of the first storage section, and is provided with a connecting oil passage that connects the first storage section and the second storage section and allows hydraulic oil to communicate.

[0007] According to the present invention, a first reservoir and a second reservoir are provided, the second reservoir is provided at a higher position than the first reservoir, and a connecting oil passage is connected between the first reservoir and the second reservoir. When hydraulic oil is poured into the first and second reservoirs until the liquid level of the hydraulic oil is located in the second reservoir, the pressure of the hydraulic oil in the first reservoir is increased because the second reservoir is located at a higher position than the first reservoir.

[0008] According to the present invention, when the hydraulic oil in the first reservoir is sucked into the hydraulic pump in the above-mentioned state, the pressure of the hydraulic oil in the first reservoir is increased in advance, so even if the pressure of the hydraulic oil temporarily drops due to suction by the hydraulic pump, the pressure of the hydraulic oil is unlikely to drop to a pressure at which bubbles are generated. By reducing the chance of the hydraulic oil pressure dropping to a level where bubbles are generated, the generation of bubbles is suppressed and the occurrence of cavitation is suppressed, thereby improving the durability of the hydraulic pump that draws hydraulic oil from the first reservoir.

[0009] In the present invention, it is preferable that the connecting oil passage connects an upper portion of the first storage portion to a lower portion of the second storage portion.

[0010] According to the present invention, the connecting oil passage is connected across the upper part of the first storage section and the lower part of the second storage section, so that the connecting oil passage is not longer than necessary, thereby simplifying the structure.

[0011] According to the present invention, by connecting the connecting oil passage to the lower part of the second storage section, the hydraulic oil in the second storage section can easily enter the connecting oil passage, and the amount of hydraulic oil remaining in the second storage section can be reduced, thereby reducing the amount of contaminants remaining in the second storage section. As a result, when the hydraulic oil in the second reservoir is sucked into the hydraulic pump, less contaminants flow into the hydraulic pump, thereby improving the durability of the hydraulic pump that sucks the hydraulic oil from the second reservoir.

[0012] In the present invention, it is preferable that the second storage section has a wall member that divides the interior of the second storage section into an upper region and a lower region, and a communication passage that connects the upper region and the lower region, and that the connecting oil passage is connected to the lower region.

[0013] According to the present invention, the interior of the second reservoir is divided into an upper region and a lower region by a wall member, so that even if contaminants move from the upper region of the second reservoir to the lower region through the connecting passage, the contaminants are unlikely to move from the lower region of the second reservoir to the upper region through the connecting passage. By connecting the connecting oil passage to the lower region of the second reservoir, contaminants can easily enter the connecting oil passage, which is advantageous in terms of reducing the amount of contaminants remaining in the second reservoir and in terms of improving the durability of the hydraulic pump that draws hydraulic oil from the second reservoir.

[0014] In the present invention, it is preferable that the communicating passage is provided near one of two sets of wall portions that face each other in the second storage section, and the portion of the connecting oil passage that is connected to the lower region is provided near the other of the two sets of wall portions that face each other in the second storage section.

[0015] According to the present invention, the connecting oil passage and the communicating passage are provided near one wall portion and the other wall portion of the second reservoir, and are spaced apart from each other. Therefore, when contaminants move from the upper region of the second reservoir through the communicating passage to the lower region and move near the connecting oil passage, the contaminants are unlikely to move from the lower region of the second reservoir through the communicating passage to the upper region. This is advantageous in that it reduces the amount of contaminants remaining in the second reservoir, and is advantageous in that it improves the durability of the hydraulic pump that draws the hydraulic oil from the second reservoir.

[0016] In the present invention, it is preferable that the second reservoir be provided with an oil supply section capable of replenishing hydraulic oil.

[0017] As described above, the second reservoir is located higher than the first reservoir, so the pressure of the hydraulic oil in the first reservoir is increased, or in other words, the pressure of the hydraulic oil in the second reservoir is lower than the pressure of the hydraulic oil in the first reservoir.

[0018] According to the present invention, the second storage section is provided with an oil supply section that can replenish hydraulic oil, so when hydraulic oil is replenished from the oil supply section to the second storage section, the pressure of the hydraulic oil in the second storage section does not become a resistance, and the hydraulic oil is replenished from the oil supply section to the second storage section without any difficulty.

[0019] In the present invention, it is preferable that a first oil supply passage be provided to supply the hydraulic oil in the first reservoir to some of the plurality of working devices, and a second oil supply passage be provided to supply the hydraulic oil in the second reservoir to some of the plurality of working devices.

[0020] According to the present invention, in a work vehicle which is often provided with a plurality of working devices in various sections, the first storage section and the second storage section are provided separately. The hydraulic oil in the first reservoir is supplied via the first oil supply passage to the working device to which the hydraulic oil in the first reservoir is preferably supplied due to its positional relationship with the first reservoir, and the hydraulic oil in the second reservoir is supplied via the second oil supply passage to the working device to which the hydraulic oil in the second reservoir is preferably supplied due to its positional relationship with the second reservoir.

[0021] This allows for a configuration in which hydraulic oil is efficiently supplied to the working devices in each part of a work vehicle, which often has multiple working devices installed in each part, thereby simplifying the hydraulic oil supply system to the working devices.

[0022] In the present invention, it is preferable that the second storage section has a wall member that divides the interior of the second storage section into an upper region and a lower region, and a communication passage that connects the upper region and the lower region, and that the second supply oil passage is connected to the upper region.

[0023] According to the present invention, the interior of the second reservoir is divided into an upper region and a lower region by a wall member, so that even if contaminants move from the upper region of the second reservoir to the lower region through the connecting passage, the contaminants are unlikely to move from the lower region of the second reservoir to the upper region through the connecting passage.

[0024] As a result, by connecting the second supply oil passage to the upper region of the second reservoir, when the hydraulic oil in the upper region of the second reservoir is sucked into the hydraulic pump, less contaminants flow into the hydraulic pump, thereby improving the durability of the hydraulic pump that sucks the hydraulic oil from the upper region of the second reservoir.

[0025] In the present invention, it is preferable that a first return oil passage be provided for returning hydraulic oil from some of the plurality of working devices to the first reservoir, and a second return oil passage be provided for returning hydraulic oil from some of the plurality of working devices to the second reservoir.

[0026] According to the present invention, in a work vehicle which is often provided with a plurality of working devices in various sections, the first storage section and the second storage section are provided separately. Due to the positional relationship with the first reservoir, hydraulic oil from the working device that is preferably returned to the first reservoir is returned to the first reservoir via the first return oil passage. Due to the positional relationship with the second reservoir, hydraulic oil from the working device that is preferably returned to the second reservoir is returned to the second reservoir via the second return oil passage.

[0027] This allows the hydraulic oil from each working device in a work vehicle, which often has multiple working devices installed in different parts, to be efficiently returned, thereby simplifying the return system for the hydraulic oil of the working devices.

[0028] In the present invention, it is preferable that the system includes a first supply oil passage that supplies the hydraulic oil in the first reservoir to some of the working devices among the plurality of working devices, a second supply oil passage that supplies the hydraulic oil in the second reservoir to some of the working devices among the plurality of working devices, a first return oil passage that returns the hydraulic oil coming out of some of the working devices among the plurality of working devices to the first reservoir, and a second return oil passage that returns the hydraulic oil coming out of some of the working devices among the plurality of working devices to the second reservoir, and includes the working device to which the hydraulic oil is supplied from the first supply oil passage and which outputs the hydraulic oil to the first return oil passage, and the working device to which the hydraulic oil is supplied from the second supply oil passage and which outputs the hydraulic oil to the second return oil passage.

[0029] According to the present invention, in a work vehicle which is often provided with a plurality of working devices in various sections, the first storage section and the second storage section are provided separately. The hydraulic oil in the first reservoir is supplied via the first oil supply passage to the working device to which the hydraulic oil in the first reservoir is preferably supplied due to its positional relationship with the first reservoir, and the hydraulic oil in the second reservoir is supplied via the second oil supply passage to the working device to which the hydraulic oil in the second reservoir is preferably supplied due to its positional relationship with the second reservoir. Due to the positional relationship with the first reservoir, hydraulic oil from the working device that is preferably returned to the first reservoir is returned to the first reservoir via the first return oil passage. Due to the positional relationship with the second reservoir, hydraulic oil from the working device that is preferably returned to the second reservoir is returned to the second reservoir via the second return oil passage.

[0030] In a working device to which hydraulic oil from the first reservoir is preferably supplied due to its positional relationship with the first reservoir, it may be preferable that hydraulic oil from the working device be returned to the first reservoir. According to the present invention, hydraulic oil in the first reservoir is supplied to the working device as described above via the first supply oil passage, and hydraulic oil leaving the working device is returned to the first reservoir via the first return oil passage.

[0031] In a working device to which hydraulic oil from the second reservoir is preferably supplied due to its positional relationship with the second reservoir, it may be preferable that hydraulic oil discharged from the working device be returned to the second reservoir. According to the present invention, hydraulic oil in the second reservoir is supplied to the above-described working device via the second supply oil passage, and hydraulic oil discharged from the working device is returned to the second reservoir via the second return oil passage.

[0032] This allows for a configuration in which hydraulic oil is efficiently supplied to the working devices of each part of a work vehicle, which often has multiple working devices installed in each part, and allows for a configuration in which the hydraulic oil coming out of the working devices of each part is efficiently returned, thereby simplifying the supply and return systems for the hydraulic oil of the working devices.

[0033] In the present invention, it is preferable that the first storage section has a partition member that divides the interior of the first storage section into a first region and a second region, and a strainer through which hydraulic oil from the second region can enter the first region, and that the first supply oil passage is connected to the first region, and the connecting oil passage and the first return oil passage are connected to the second region.

[0034] According to the present invention, the interior of the first storage portion is divided into a first area and a second area by the partition member, and the first area and the second area are connected by the strainer. The hydraulic oil and contaminants in the second reservoir enter the second region of the first reservoir through a connecting oil passage. The hydraulic oil and contaminants for the working device enter the second region of the first reservoir through a first return oil passage. The hydraulic oil in the second region of the first reservoir enters the first region through a strainer and is supplied from the first region to the working device through a first supply oil passage.

[0035] This allows the strainer to reduce the amount of contaminants entering the first supply oil passage, so when the hydraulic oil in the first reservoir is sucked into the hydraulic pump, less contaminants flow into the hydraulic pump, which is advantageous in terms of improving the durability of the hydraulic pump that sucks the hydraulic oil from the first reservoir.

[0036] According to the present invention, when multiple first supply oil passages are provided, the first region of the first reservoir is configured to have an appropriate volume, so that the multiple first supply oil passages can be easily connected to the first region of the first reservoir. According to the present invention, the hydraulic oil that enters the first area from the second area of ​​the first storage section through the strainer is distributed to multiple first supply oil passages in the first area of ​​the first storage section, so that a small number of strainers can be used for multiple first supply oil passages, and there is no need to provide a strainer for each of the multiple first supply oil passages.

[0037] This simplifies the structure of the first storage section by allowing multiple first supply oil passages to be easily connected to the first region of the first storage section and by allowing multiple first supply oil passages to be accommodated with a small number of strainers.

[0038] In the present invention, it is preferable that the first area is provided at the upper part of the interior of the first storage section, and the strainer is connected to the lower part of the first area and extends downward from the lower part of the first area.

[0039] According to the present invention, the first region of the first storage section and the strainer are compactly housed side by side in the vertical direction inside the first storage section, which is advantageous in terms of simplifying the structure of the first storage section.

[0040] In the present invention, it is preferable that the first region is provided in one of the left-right directions or one of the front-to-rear directions at the upper part of the interior of the first storage section, and that the connecting oil passage is connected to a portion of the second region adjacent to the first region.

[0041] According to the present invention, the connecting oil passage and the first region of the first storage section are compactly accommodated side by side along the left-right or front-to-back direction inside the first storage section, which is advantageous in terms of simplifying the structure of the first storage section.

[0042] In the present invention, it is preferable that the working device is supplied with hydraulic oil from the first supply oil passage and outputs the hydraulic oil to the second return oil passage.

[0043] In a work vehicle, due to the positional relationship between the first and second storage sections, in a work device where it is preferable to supply hydraulic oil from the first storage section, it may be preferable for the hydraulic oil leaving the work device to be returned to the second storage section. According to the present invention, hydraulic oil from the first reservoir is supplied to the working device via the first supply oil passage, and hydraulic oil leaving the working device is returned to the second reservoir via the second return oil passage, which is advantageous in terms of simplifying the hydraulic oil supply system and return system of the working device.

[0044] In the present invention, it is preferable that the working device is supplied with hydraulic oil from the second supply oil passage and outputs the hydraulic oil to the first return oil passage.

[0045] In a work vehicle, due to the positional relationship between the first and second storage sections, in a work device where it is preferable to supply hydraulic oil from the second storage section, it may be preferable for the hydraulic oil leaving the work device to be returned to the first storage section. According to the present invention, hydraulic oil from the second reservoir is supplied to the working device via the second supply oil passage, and hydraulic oil leaving the working device is returned to the first reservoir via the first return oil passage, which is advantageous in terms of simplifying the hydraulic oil supply system and return system of the working device.

[0046] In the present invention, it is preferable that the second storage section has a wall member that divides the interior of the second storage section into an upper region and a lower region, a communication passage that connects the upper region and the lower region, and includes the second return oil passage that is connected to the lower region.

[0047] According to the present invention, the interior of the second reservoir is divided into an upper region and a lower region by a wall member, so that even if contaminants move from the upper region of the second reservoir to the lower region through the connecting passage, the contaminants are unlikely to move from the lower region of the second reservoir to the upper region through the connecting passage.

[0048] When hydraulic oil leaving the working device is returned to the second reservoir via the second return oil passage, the inclusion of a second return oil passage connected to the lower region of the second reservoir reduces the amount of contaminants generated in the working device entering the upper region of the second reservoir. As a result, when hydraulic oil in the upper region of the second reservoir is sucked into the hydraulic pump, less contaminants flow into the hydraulic pump, thereby improving the durability of the hydraulic pump that sucks hydraulic oil from the upper region of the second reservoir.

[0049] In the present invention, it is preferable that upper and lower pipe members are provided that connect the upper portion of the second storage section and the lower portion, passing through the upper portion, and that the second return oil passage connected to the lower portion is connected to the upper and lower pipe members.

[0050] Depending on the positional relationship between the second reservoir and the second return oil passage, it may be difficult for the second return oil passage to be directly connected to the lower region of the second reservoir. According to the present invention, the upper and lower pipe members penetrate the upper region of the second storage portion and connect the upper and lower regions of the second storage portion. By connecting the second return oil passage to the upper and lower pipe members, when it is difficult to directly connect the second return oil passage to the lower region of the second storage portion, the second return oil passage can be smoothly connected to the lower region of the second storage portion via the upper and lower pipe members.

[0051] This allows the hydraulic oil from the working devices to be efficiently returned to the lower area of ​​the second reservoir in work vehicles, which often have multiple working devices installed in various sections, which is advantageous in terms of simplifying the return system for the working device hydraulic oil.

[0052] In the present invention, it is preferable that the communicating passage is provided near one of two sets of wall portions facing each other in the second storage section, a horizontal pipe member is provided extending from one of the two sets of wall portions facing each other in the second storage section across the communicating passage to the lower region, and the second return oil passage connected to the lower region is connected to the horizontal pipe member.

[0053] Depending on the positional relationship between the second reservoir and the second return oil passage, it may be difficult for the second return oil passage to be directly connected to the lower region of the second reservoir. According to the present invention, the horizontal pipe member extends from the wall portion of the second reservoir on the side of the communicating passage, over the communicating passage, to the lower region of the second reservoir. By connecting the second return oil passage to the horizontal pipe member, the second return oil passage can be smoothly connected to the lower region of the second reservoir via the horizontal pipe member in cases where it is difficult to directly connect the second return oil passage to the lower region of the second reservoir.

[0054] This allows the hydraulic oil from the working devices to be efficiently returned to the lower area of ​​the second reservoir in work vehicles, which often have multiple working devices installed in various sections, which is advantageous in terms of simplifying the return system for the working device hydraulic oil.

[0055] According to the present invention, the horizontal pipe member crosses the connecting passage of the second storage section, so that when contaminants move from the upper region of the second storage section through the connecting passage to the lower region as described above, the horizontal pipe member further prevents the contaminants from moving from the lower region of the second storage section through the connecting passage to the upper region.

[0056] This reduces the amount of contaminants flowing into the hydraulic pump when hydraulic oil from the upper region of the second reservoir is sucked into the hydraulic pump, which is advantageous in terms of improving the durability of the hydraulic pump that sucks hydraulic oil from the upper region of the second reservoir.

[0057] In the present invention, the second storage section preferably has a wall member that divides the interior of the second storage section into an upper region and a lower region, a communication passage that connects the upper region and the lower region, includes the second return oil passage that is connected to the upper region, and is provided with a filter that allows the hydraulic oil in the second return oil passage that is connected to the upper region to pass through and be returned to the upper region.

[0058] According to the present invention, the interior of the second reservoir is divided into an upper region and a lower region by a wall member, so that even if contaminants move from the upper region of the second reservoir to the lower region through the connecting passage, the contaminants are unlikely to move from the lower region of the second reservoir to the upper region through the connecting passage.

[0059] According to the present invention, when a second return oil passage is provided to return hydraulic oil from the working device to the second reservoir, the second return oil passage is included which is connected to the upper region of the second tank, and the hydraulic oil in this second return oil passage is returned to the upper region of the second reservoir through a filter. This allows the filter to reduce the amount of contaminants entering the upper region of the second reservoir, so when the hydraulic oil from the second reservoir is sucked into the hydraulic pump, less contaminants flow into the hydraulic pump, improving the durability of the hydraulic pump that sucks the hydraulic oil from the second reservoir.

[0060] In the present invention, it is preferable that the working device includes a hydrostatic continuously variable transmission that drives the traveling device.

[0061] According to the present invention, a configuration suitable for a work vehicle having a hydrostatic continuously variable transmission that drives a traveling device as a work device can be obtained.

[0062] In the present invention, it is preferable that the working device includes a conveying device that conveys and discharges the processed material to the outside.

[0063] According to the present invention, a configuration suitable for a work vehicle having a transport device as a work device for transporting and discharging materials to the outside can be obtained. [Brief explanation of the drawings]

[0064] [Figure 1] FIG. 2 is a left side view of the sugarcane harvester. [Figure 2] FIG. 2 is a schematic diagram showing the entire hydraulic circuit. [Figure 3] FIG. 2 is a longitudinal sectional front view of the first tank and the second tank. [Figure 4] FIG. 2 is a longitudinal sectional left side view of the first tank and the second tank. DETAILED DESCRIPTION OF THE INVENTION

[0065] Figures 1 to 4 show a sugarcane harvester, which is an example of a work vehicle, and in Figures 1 to 4, F indicates the forward direction, B indicates the backward direction, U indicates the upward direction, D indicates the downward direction, R indicates the right direction, and L indicates the left direction.

[0066] (Overall configuration of sugarcane harvester) As shown in Figure 1, the cutting unit 3 (corresponding to a working device) and the first conveying device 4 (corresponding to a working device) are connected to form the machine body 13, and the first conveying device 4 extends diagonally upward and rearward from the rear of the cutting unit 3.

[0067] Right and left front wheels 1 are attached to the right and left parts of the reaping unit 3. An upper cutting device 7 (corresponding to a working device) is provided on the top of the reaping unit 3 and is positioned above and in front of the reaping unit 3. Right and left rear wheels 2 (corresponding to a traveling device) are provided on the lower part of the rear part of the first conveying device 4, and the front wheels 1 and rear wheels 2 support the machine body 13.

[0068] A sorting device 5 (corresponding to a working device) is provided at the rear of the first conveying device 4 along the vertical direction, and a second conveying device 6 (corresponding to a conveying device) (corresponding to a working device) extends diagonally upward from the bottom of the sorting device 5. A driving unit 9 is provided at the top of the reaping unit 3, and an engine 10 is provided at the top of the front part of the first conveying device 4.

[0069] (Sugarcane harvester in operation) As shown in Figure 1, as the machine body 13 moves forward, the upper leaves of the crops in the field are cut by the upper cutting device 7, and the crops in the field are introduced into the reaping unit 3. The crops introduced into the reaping unit 3 are leaned forward, the bases of the plants are cut, and the crops are supplied from the bases to the first conveying device 4. The crops supplied to the first conveying device 4 are transported diagonally upward and rearward along the first conveying device 4, cut to a predetermined length at the rear end of the first conveying device 4, and supplied to the top of the sorting device 5.

[0070] The crops supplied to the top of the sorting device 5 fall into the front part of the second conveying device 6. A sorting fan 5a (see Figure 2) is provided at the top of the sorting device 5, and sorting wind from the sorting fan 5a is generated in an upward direction inside the sorting device 5. Inside the sorting device 5, the crops fall into the front part of the second conveying device 6 below, and impurities are separated from the crops by the sorting wind and discharged from the top of the sorting device 5.

[0071] The crops that fall onto the front of the second conveying device 6 are transported diagonally upward by the second conveying device 6. A transport vehicle (not shown) accompanies the sugarcane harvester, and the crops are dumped from the rear of the second conveying device 6 onto the loading platform of the transport vehicle.

[0072] (Overview of hydraulic systems in sugarcane harvesters) As shown in FIG. 2, hydraulic pumps 23, 24, 25, 26, 27, 28, and 29 are provided which are driven by the engine 10 (see FIG. 1).

[0073] A steering device 17 (corresponding to a working device) is provided to steer the front wheels 1. When a control handle (not shown) provided on the driver's section 9 is operated, the front wheels 1 are steered by the steering device 17.

[0074] The vehicle is provided with a hydrostatic continuously variable transmission 8 (corresponding to a working device), and the hydrostatic continuously variable transmission 8 drives the rear wheels 2 (see FIG. 1), causing the vehicle body 13 to move forward and backward. The hydrostatic continuously variable transmission 8 has a hydraulic pump 8a, a hydraulic motor 8b, and a charge pump 8c (corresponding to a hydraulic pump), and the hydraulic pump 8a and charge pump 8c of the hydrostatic continuously variable transmission 8 are driven by an engine 10 (see FIG. 1).

[0075] There are provided hydraulic cylinders (not shown) for raising and lowering the second conveying device 6 and changing its direction, hydraulic cylinders (not shown) for raising and lowering the front wheels 1, and hydraulic cylinders (not shown) for raising and lowering the upper cutting device 7, and a control valve unit 18 (corresponding to a working device) for supplying and discharging hydraulic oil to these hydraulic cylinders.

[0076] 1 and 2, a radiator 30 and three oil coolers 20, 21, and 22 are provided in the upper rear part of the first transfer device 4. A blower fan 19 (corresponding to a working device) that supplies cooling air to the radiator 30 and the oil coolers 20, 21, and 22 is provided in the upper rear part of the first transfer device 4.

[0077] The harvesting section 3, first conveying device 4, sorting device 5 (sorting fan 5a), second conveying device 6, upper cutting device 7, hydrostatic continuously variable transmission 8, steering device 17, control valve unit 18, blower fan 19, etc. are configured as a hydraulically operated type that operates when hydraulic oil from the first tank 11 (corresponding to the first storage section) and the second tank 12 (corresponding to the second storage section) described below is supplied by hydraulic pumps 23 to 29 and the charge pump 8c of the hydrostatic continuously variable transmission 8.

[0078] (Configuration of first tank 11) As shown in Figure 1, the first tank 11 is provided on the left side of the front part of the first conveying device 4 (rear part of the reaping unit 3), between the left front wheel 1 and the left rear wheel 2, and hydraulic oil is stored in the first tank 11.

[0079] As shown in FIGS. 3 and 4, the first tank 11 is configured in a box shape having a ceiling portion 11a, a right wall portion 11b, a left wall portion 11c, a front wall portion 11d, a rear wall portion 11e, and a bottom portion 11f. Inside the first tank 11, a flat partition member 11g is attached across the ceiling portion 11a, the left wall portion 11c, and the rear wall portion 11e, and a first area 11h and a second area 11j are provided, separated by the partition member 11g.

[0080] The first region 11h is provided in the upper left part of the interior of the first tank 11. Two strainers 14 are attached to the lower part of the partition member 11g side by side in the front-to-rear direction, and extend from the lower part of the partition member 11g downward toward the bottom part 11f.

[0081] (Configuration of second tank 12) As shown in Fig. 1, the second tank 12 is provided on the left side of the rear (upper) part of the first conveying device 4, and hydraulic oil is stored in the second tank 12. The second tank 12 is configured to have a smaller volume than the first tank 11. The second tank 12 is provided at a position higher than the ceiling part 11a of the first tank 11, and is provided behind the first tank 11.

[0082] As shown in Figures 3 and 4, the second tank 12 is configured in a box shape having a ceiling portion 12a, a right wall portion 12b (corresponding to a wall portion), a left wall portion 12c (corresponding to a wall portion), a front wall portion 12d, a rear wall portion 12e, and a bottom portion 12f.

[0083] Inside the second tank 12, a wall member 12g is attached across the left wall portion 12c, the front wall portion 12d, and the rear wall portion 12e, providing an upper region 12h and a lower region 12j separated by the wall member 12g. A communication passage 12k is provided between the right wall portion 12b and the right end of the wall member 12g, and the upper region 12h and the lower region 12j communicate with each other via the communication passage 12k.

[0084] A filter 15 is disposed in an upper region 12h of the second tank 12 and attached to the ceiling portion 12a of the second tank 12. An oil supply portion 12m of the second tank 12 is provided on the upper left side of the rear wall portion 12e, and hydraulic oil is supplied from the oil supply portion 12m of the second tank 12 to the upper region 12h.

[0085] The upper and lower pipe members 31 are attached across the ceiling portion 12a and wall member 12g of the second tank 12, penetrating the upper region 12h of the second tank 12, and the lower portions of the upper and lower pipe members 31 are connected to the lower region 12j of the second tank 12.

[0086] The horizontal pipe member 32 is attached to the right wall portion 12b of the second tank 12, passes through the communication passage 12k from the right wall portion 12b of the second tank 12, and enters the inside of the lower region 12j. An end of the horizontal pipe member 32 is located near the center of the left and right of the lower region 12j of the second tank 12.

[0087] (Configuration of connecting oil passage 16) As shown in FIGS. 3 and 4, a connecting oil passage 16 through which hydraulic oil can be communicated connects the first tank 11 and the second tank 12.

[0088] An upper portion 16a of the connecting oil passage 16 is attached to the left portion of the bottom portion 12f of the second tank 12, and is connected to the lower region 12j of the second tank 12 near the left wall portion 12c. A lower portion 16b of the connecting oil passage 16 is attached to the right portion of the upper portion of the rear wall portion 11e of the first tank 11, and is connected to the second region 11j of the first tank 11. The lower portion 16b of the connecting oil passage 16 is connected to a portion of the upper portion of the second region 11j of the first tank 11 that is adjacent to the first region 11h, and the first region 11h of the first tank 11 and the lower portion 16b of the connecting oil passage 16 are arranged side by side in the left-right direction.

[0089] The hydraulic oil in the upper region 12h of the second tank 12 passes from the upper region 12h of the second tank 12 through the communicating passage 12k and the lower region 12j to enter the connecting oil passage 16, and can then pass through the connecting oil passage 16 to enter the second region 11j of the first tank 11. Under normal conditions, the hydraulic oil is poured into the second tank 12 until the liquid level of the hydraulic oil is located near the ceiling portion 12a of the second tank 12, and the first tank 11 is full of hydraulic oil.

[0090] (Configuration of hydraulic circuit of reaping unit 3) As shown in Figures 2, 3, and 4, oil passage 33 (corresponding to the first supply oil passage) is connected to the ceiling portion 11a of the first tank 11 and connected to the first region 11h, and is connected from the first tank 11 to the hydraulic pump 23, and from the hydraulic pump 23 to the cutting unit 3.

[0091] An oil passage 43 (corresponding to the second return oil passage) is connected to the cutting section 3, from the cutting section 3 to the oil cooler 20, from the oil cooler 20 to the filter 15 of the second tank 12, and to the upper region 12h of the second tank 12.

[0092] The hydraulic oil in the second region 11j of the first tank 11 passes through the strainer 14 into the first region 11h of the first tank 11, is sucked into the hydraulic pump 23 through the oil passage 33, and the hydraulic oil in the hydraulic pump 23 is supplied to the cutting unit 3 through the oil passage 33, causing the cutting unit 3 to operate.

[0093] The hydraulic oil that operates the cutting unit 3 leaves the cutting unit 3, passes through the oil passage 43, and is supplied to the oil cooler 20. From the oil cooler 20, it passes through the oil passage 43 and the filter 15 and returns to the upper region 12h of the second tank 12.

[0094] (Configuration of hydraulic circuit of first transfer device 4) As shown in Figures 2, 3, and 4, an oil passage 34 (corresponding to the first supply oil passage) is connected to the ceiling portion 11a of the first tank 11 and connected to the first region 11h, and is connected from the first tank 11 to the hydraulic pump 24, and from the hydraulic pump 24 to the first conveying device 4.

[0095] An oil passage 44 (corresponding to the second return oil passage) is connected to the first conveying device 4, from the first conveying device 4 to the oil cooler 21, from the oil cooler 21 to the filter 15 of the second tank 12, and to the upper region 12h of the second tank 12.

[0096] An oil passage 50 (corresponding to the second return oil passage) is connected to the first conveying device 4, and is connected from the first conveying device 4 to the horizontal pipe member 32 of the second tank 12, and is connected to the lower region 12j of the second tank 12.

[0097] The hydraulic oil in the second region 11j of the first tank 11 passes through the strainer 14 into the first region 11h of the first tank 11, is sucked into the hydraulic pump 24 through the oil passage 34, and the hydraulic oil in the hydraulic pump 24 is supplied to the first conveying device 4 through the oil passage 34, causing the first conveying device 4 to operate.

[0098] The hydraulic oil that operates the first conveying device 4 leaves the first conveying device 4 and is supplied to the oil cooler 21 through the oil passage 44, and then returns from the oil cooler 21 to the upper region 12h of the second tank 12 through the oil passage 44 and the filter 15. The hydraulic oil leaked during operation of the first transfer device 4 passes through the oil passage 50 and returns from the horizontal pipe member 32 to the lower region 12j of the second tank 12.

[0099] (Configuration of hydraulic circuit of sorting device 5) As shown in Figures 2, 3, and 4, an oil passage 35 (corresponding to the first supply oil passage) is connected to the ceiling portion 11a of the first tank 11 and connected to the first region 11h, and is connected from the first tank 11 to the hydraulic pump 25, and from the hydraulic pump 25 to the sorting device 5 (sorting fan 5a).

[0100] An oil passage 45 (corresponding to the second return oil passage) is connected to the sorting device 5 (sorting fan 5a), from the sorting device 5 (sorting fan 5a) to the oil cooler 22, from the oil cooler 22 to the filter 15 of the second tank 12, and to the upper region 12h of the second tank 12.

[0101] The hydraulic oil in the second area 11j of the first tank 11 passes through the strainer 14 into the first area 11h of the first tank 11, is sucked into the hydraulic pump 25 through the oil passage 35, and the hydraulic oil in the hydraulic pump 25 is supplied to the sorting device 5 through the oil passage 35, and the sorting fan 5a of the sorting device 5 operates.

[0102] The hydraulic oil that operates the sorting fan 5a of the sorting device 5 leaves the sorting device 5 and is supplied to the oil cooler 22 through the oil passage 45, and then returns from the oil cooler 22 through the oil passage 45 and the filter 15 to the upper region 12h of the second tank 12.

[0103] (Configuration of hydraulic circuits of upper cutting device 7 and steering device 17) As shown in Figures 2, 3, and 4, an oil passage 37 (corresponding to the first supply oil passage) is connected to the ceiling portion 11a of the first tank 11 and connected to the first region 11h, and is connected from the first tank 11 to the hydraulic pump 27, from the hydraulic pump 27 to the steering device 17, and from the steering device 17 to the upper cutting device 7.

[0104] An oil passage 47 (corresponding to the first return oil passage) is connected to the upper cutting device 7 and the steering device 17, and the two oil passages 47 merge and connect to the upper part of the right wall portion 11b of the first tank 11, and are connected to the second region 11j of the first tank 11.

[0105] The hydraulic oil in the second region 11j of the first tank 11 passes through the strainer 14 into the first region 11h of the first tank 11, is sucked into the hydraulic pump 27 through the oil passage 37, and the hydraulic oil in the hydraulic pump 27 is supplied to the upper cutting device 7 and the steering device 17 through the oil passage 37, thereby operating the upper cutting device 7 and the steering device 17.

[0106] The hydraulic oil that has operated the upper cutting device 7 and the steering device 17 leaves the upper cutting device 7 and the steering device 17 and passes through the oil passage 47 to return to the second region 11 j of the first tank 11 .

[0107] (Configuration of hydraulic circuit of blower fan 19) As shown in Figures 2, 3, and 4, an oil passage 39 (corresponding to the first supply oil passage) is connected to the ceiling portion 11a of the first tank 11 and connected to the first region 11h, and is connected from the first tank 11 to the hydraulic pump 29, and from the hydraulic pump 29 to the blower fan 19.

[0108] An oil passage 49 (corresponding to a second return oil passage) is connected to the blower fan 19, and is connected from the blower fan 19 to the upper and lower pipe members 31 of the second tank 12, and is connected to the lower region 12j of the second tank 12.

[0109] The hydraulic oil in the second region 11j of the first tank 11 passes through the strainer 14 and enters the first region 11h of the first tank 11, and is sucked into the hydraulic pump 29 through the oil passage 39. The hydraulic oil in the hydraulic pump 29 is supplied to the blower fan 19 through the oil passage 39, and the blower fan 19 operates. The hydraulic oil that has operated the blower fan 19 leaves the blower fan 19 and passes through the oil passage 49 and the upper and lower pipe members 31 of the second tank 12, and returns to the lower region 12j of the second tank 12.

[0110] (Configuration of Hydraulic Circuit of Second Conveyor Device 6) As shown in Figures 2, 3, and 4, an oil passage 36 (corresponding to a second supply oil passage) is connected to the front wall portion 12d of the second tank 12 and connected to the upper region 12h, and is connected from the second tank 12 to the hydraulic pump 26, and from the hydraulic pump 26 to the second conveying device 6.

[0111] An oil passage 46 (corresponding to a second return oil passage) is connected to the second conveying device 6, and is connected from the second conveying device 6 to the upper and lower pipe members 31 of the second tank 12, and is connected to the lower region 12j of the second tank 12.

[0112] The hydraulic oil in the upper region 12h of the second tank 12 is sucked into the hydraulic pump 26 through the oil passage 36, and the hydraulic oil in the hydraulic pump 26 is supplied to the second conveying device 6 through the oil passage 36, causing the second conveying device 6 to operate. The hydraulic oil that has operated the second transfer device 6 leaves the second transfer device 6 and passes through the oil passage 46 and the upper and lower pipe members 31 of the second tank 12, and returns to the lower region 12j of the second tank 12.

[0113] (Configuration of hydraulic circuit of control valve unit 18) As shown in Figures 2, 3, and 4, an oil passage 38 (corresponding to a second supply oil passage) is connected to the front wall portion 12d of the second tank 12 and connected to the upper region 12h, and is connected from the second tank 12 to the hydraulic pump 28, and from the hydraulic pump 28 to the control valve unit 18.

[0114] An oil passage 48 (corresponding to the first return oil passage) is connected to the control valve unit 18, and is connected from the control valve unit 18 to the upper part of the rear wall portion 11e of the first tank 11, and is connected to the second region 11j of the first tank 11.

[0115] The hydraulic oil in the upper region 12h of the second tank 12 is sucked into the hydraulic pump 28 through the oil passage 38, and the hydraulic oil in the hydraulic pump 28 is supplied to the control valve unit 18 through the oil passage 38, causing the control valve unit 18 to operate. The hydraulic oil that has actuated the control valve unit 18 leaves the control valve unit 18 and passes through the oil passage 48 to return to the second region 11 j of the first tank 11 .

[0116] (Configuration of hydraulic circuit of hydrostatic continuously variable transmission 8) As shown in Figures 2, 3, and 4, an oil passage 40 (corresponding to a second supply oil passage) is connected to the front wall portion 12d of the second tank 12 and connected to the upper region 12h, and is connected from the second tank 12 to the charge pump 8c of the hydrostatic continuously variable transmission 8.

[0117] An oil passage 51 (corresponding to the second return oil passage) is connected to the hydraulic pump 8a of the hydrostatic continuously variable transmission 8, and is connected from the hydraulic pump 8a of the hydrostatic continuously variable transmission 8 to the front wall portion 12d of the second tank 12, and is connected to the lower region 12j of the second tank 12.

[0118] An oil passage 52 (corresponding to the second return oil passage) is connected to the hydraulic motor 8b of the hydrostatic continuously variable transmission 8, and is connected from the hydraulic motor 8b of the hydrostatic continuously variable transmission 8 to the rear wall portion 12e of the second tank 12, and is connected to the lower region 12j of the second tank 12.

[0119] The hydraulic oil in the upper region 12h of the second tank 12 passes through the oil passage 40 and is sucked into the charge pump 8c of the hydrostatic continuously variable transmission 8, and is supplied from the charge pump 8c of the hydrostatic continuously variable transmission 8 to the hydraulic pump 8a and hydraulic motor 8b of the hydrostatic continuously variable transmission 8.

[0120] When the hydrostatic continuously variable transmission 8 is in operation, hydraulic oil leaking from the hydraulic pump 8a and hydraulic motor 8b of the hydrostatic continuously variable transmission 8 passes through the oil passages 51 and 52 and returns to the lower region 12j of the second tank 12.

[0121] (First Alternative Embodiment of the Invention) A plurality of second tanks 12, such as two or three, may be provided. According to this configuration, the connecting oil passages 16 may be configured to extend from each of the plurality of second tanks 12 and connect to the first tank 11. When a plurality of second tanks 12 are provided, the second tanks 12 do not all have to be provided at the same height, and the heights of the plurality of second tanks 12 may be configured to be different from one another.

[0122] (Second Alternative Embodiment of the Invention) A plurality of first tanks 11, such as two or three, may be provided. According to this configuration, it is preferable that an oil passage (not shown) is connected across adjacent first tanks 11, so that all of the first tanks 11 communicate with each other. When a plurality of first tanks 11 are provided, all of the first tanks 11 do not have to be provided at the same height, and the heights of the plurality of first tanks 11 may be configured to be different from each other.

[0123] (Third Alternative Embodiment of the Invention) A plurality of connecting oil passages 16 may be configured to extend from one second tank 12 and connect to one first tank 11. A plurality of connecting oil passages 16 may be configured to extend from one second tank 12 and connect to each of the plurality of first tanks 11.

[0124] (Fourth Alternative Embodiment of the Invention) Inside the second tank 12, a wall member 12g may be attached across the right wall portion 12b, the front wall portion 12d, and the rear wall portion 12e, and a communication passage 12k may be provided between the left wall portion 12c and the left end portion of the wall member 12g. According to this configuration, the horizontal pipe member 32 is preferably configured to pass from the left wall portion 12c of the second tank 12 through the communication passage 12k and enter the inside of the lower region 12j.

[0125] (Fifth Alternative Embodiment of the Invention) Inside the second tank 12, a plurality of communication passages 12k may be provided. According to this configuration, one of the plurality of communication paths 12k may be provided in the center of the wall member 12g.

[0126] (Sixth Alternative Embodiment of the Invention) When the first region 11h of the first tank 11 is provided in the upper left part of the interior of the first tank 11, the lower part 16b of the connecting oil passage 16 may be attached to the right part of the ceiling part 11a of the first tank 11, or to the upper part of the right wall part 11b of the first tank 11, or to the upper part of the right part of the front wall part 11d of the first tank 11.

[0127] (Seventh Alternative Embodiment of the Invention) The first region 11h of the first tank 11 may be provided in the right part of the upper part of the interior of the first tank 11 along the front-rear direction. According to this configuration, the lower part 16b of the connecting oil passage 16 may be attached to the left part of the ceiling part 11a of the first tank 11, or to the upper part of the left wall part 11c of the first tank 11, or to the upper part of the left part of the front wall part 11d of the first tank 11.

[0128] (Eighth Alternative Embodiment of the Invention) The first region 11h of the first tank 11 may be provided at the rear of the upper part of the interior of the first tank 11 along the left-right direction. According to this configuration, the lower part 16b of the connecting oil passage 16 may be attached to the front part of the ceiling part 11a of the first tank 11, or to the front part of the upper part of the right wall part 11b of the first tank 11, or to the front part of the upper part of the left wall part 11c of the first tank 11.

[0129] (Ninth Alternative Embodiment of the Invention) The first region 11h of the first tank 11 may be provided in the front part of the upper part of the interior of the first tank 11 along the left-right direction. According to this configuration, the lower part 16b of the connecting oil passage 16 may be attached to the rear part of the ceiling part 11a of the first tank 11, or to the rear part of the upper part of the right wall part 11b of the first tank 11, or to the rear part of the upper part of the left wall part 11c of the first tank 11.

[0130] (Tenth Alternative Embodiment of the Invention) The sugarcane harvester is equipped with a cutting section 3, a first conveying device 4, a sorting device 5 (sorting fan 5a), a second conveying device 6, an upper cutting device 7, a hydrostatic continuously variable transmission 8, a steering device 17, a control valve unit 18, a blower fan 19, etc. as working devices.

[0131] In this case, which working device is to be connected to the first supply oil passage and the first return oil passage can be set and changed arbitrarily, and the working device to which the first supply oil passage and the first return oil passage are connected may be eliminated.

[0132] Which working device is to be connected to the second supply oil passage and the second return oil passage can be set and changed arbitrarily, and the working device to which the second supply oil passage and the second return oil passage are connected may be eliminated.

[0133] Which working device is to be connected to the first supply oil passage and the second return oil passage can be set and changed arbitrarily, and the working device to which the first supply oil passage and the second return oil passage are connected may be eliminated.

[0134] Which working device is to be connected to the second supply oil passage and the first return oil passage can be set and changed arbitrarily, and the working device to which the second supply oil passage and the first return oil passage are connected may be eliminated.

[0135] (Correspondence to claims)-1 It is equipped with multiple working devices (cutting section 3, first conveying device 4, sorting device 5 (sorting fan 5a), second conveying device 6, upper cutting device 7, hydrostatic continuously variable transmission 8, steering device 17, control valve unit 18, and blower fan 19).

[0136] The hydraulic system is provided with a first reservoir (first tank 11) capable of storing hydraulic oil, and a second reservoir (second tank 12) capable of storing hydraulic oil. Hydraulic pumps 23, 24, 25, 26, 27, 28, and 29 (charge pump 8c) are provided to supply hydraulic oil to the working device.

[0137] The second storage section (second tank 12) is provided at a position higher than the upper end of the first storage section (first tank 11). A connecting oil passage 16 is provided which connects the first storage section (first tank 11) and the second storage section (second tank 12) and allows hydraulic oil to communicate therebetween. A connecting oil passage 16 connects the upper part of the first storage part (first tank 11) and the lower part of the second storage part (second tank 12).

[0138] (Correspondence to claims)-2 A first supply oil passage (oil passages 33, 34, 35, 37, 39) is provided to supply hydraulic oil from the first storage section (first tank 11) to some of the multiple work devices (cutting section 3, first conveying device 4, sorting device 5 (sorting fan 5a), upper cutting device 7, steering device 17, blower fan 19).

[0139] A second oil supply passage (oil passages 36, 38, 40) is provided to supply hydraulic oil from the second reservoir (second tank 12) to some of the multiple working devices (second conveying device 6, hydrostatic continuously variable transmission device 8, control valve unit 18).

[0140] A first return oil passage (oil passages 47, 48) is provided to return hydraulic oil coming out of some of the multiple working devices (upper cutting device 7, steering device 17, control valve unit 18) to the first storage section (first tank 11).

[0141] A second return oil passage (oil passages 43, 44, 45, 46, 49, 50, 51, 52) is provided to return hydraulic oil coming out of some of the multiple working devices (cutting unit 3, first conveying device 4, sorting device 5 (sorting fan 5a), second conveying device 6, hydrostatic continuously variable transmission 8, blower fan 19) to the second storage unit (second tank 12).

[0142] (Correspondence to claims) - 3 The system includes working devices (upper cutting device 7, steering device 17) that receive hydraulic oil from a first supply oil passage (oil passage 37) and send the hydraulic oil out to a first return oil passage (oil passage 47). The hydraulic oil is supplied from the second supply oil passage (oil passages 36, 40) and includes a working device (second conveying device 6, hydrostatic continuously variable transmission 8) that outputs the hydraulic oil to the second return oil passage (oil passages 46, 51, 52).

[0143] The system includes working devices (cutting section 3, first conveying device 4, sorting device 5 (sorting fan 5a), blower fan 19) that receive hydraulic oil from a first supply oil passage (oil passages 33, 34, 35, 39) and discharge the hydraulic oil to a second return oil passage (oil passages 43, 44, 45, 49). The hydraulic oil is supplied from the second supply oil passage (oil passage 38), and includes a working device (control valve unit 18) that outputs the hydraulic oil to the first return oil passage (oil passage 48).

[0144] The working device includes a hydrostatic continuously variable transmission 8 that drives the traveling device (rear wheels 2). The work devices include a conveying device (second conveying device 6) that conveys and discharges the processed material (crops) to the outside.

[0145] (Correspondence to claims)-4 The first storage section (first tank 11) has a partition member 11g that separates the interior of the first storage section (first tank 11) into a first region 11h and a second region 11j, and a strainer 14 through which hydraulic oil from the second region 11j can pass and enter the first region 11h. The first supply oil passages (oil passages 33, 34, 35, 37, 39) are connected to the first region 11h. The connecting oil passage 16 and the first return oil passages (oil passages 47, 48) are connected to the second region 11j.

[0146] The first region 11h is provided in the upper part of the interior of the first storage section (first tank 11). A strainer 14 is connected to the lower part of the first region 11h and extends downward from the lower part of the first region 11h.

[0147] The first region 11h is provided on one side in the left-right direction or one side in the front-rear direction at the upper part of the interior of the first storage portion (first tank 11). A connecting oil passage 16 is connected to a portion of the second region 11j adjacent to the first region 11h.

[0148] (Correspondence to claims) - 5 The second storage section (second tank 12) has a wall member 12g that divides the interior of the second storage section (second tank 12) into an upper region 12h and a lower region 12j, and a communication passage 12k that connects the upper region 12h and the lower region 12j. A connecting oil passage 16 is connected to the lower region 12j.

[0149] The communication passage 12k is provided near one wall (right wall 12b) of two pairs of walls (right wall 12b, left wall 12c) facing each other in the second storage section (second tank 12). The portion of the connecting oil passage 16 connected to the lower region 12j is provided near the other wall portion (left wall portion 12c) of the two pairs of walls (right wall portion 12b and left wall portion 12c) facing each other in the second storage portion (second tank 12). An oil supply portion 12m is provided that can replenish hydraulic oil in the second storage portion (second tank 12).

[0150] The second oil supply passages (oil passages 36, 38, 40) are connected to the upper region 12h. It includes second return oil passages (oil passages 46, 49, 50, 51, 52) connected to the lower region 12j.

[0151] An upper and lower pipe member 31 is provided across the upper and lower regions 12j of the second storage section (second tank 12) and connects them by passing through the upper region 12h. The second return oil passages (oil passages 46, 49) connected to the lower region 12j are connected to the upper and lower pipe members 31.

[0152] A horizontal pipe member 32 is provided which extends from one of two pairs of opposing walls (right wall 12b, left wall 12c) in the second storage section (second tank 12) across the connecting passage 12k to the lower region 12j. A second return oil passage (oil passage 50) connected to the lower region 12j is connected to the horizontal pipe member 32.

[0153] A second return oil passage (oil passages 43, 44, 45) connected to the upper region 12h is included. A filter 15 is provided to allow the hydraulic oil in the second return oil passage (oil passages 43, 44, 45) connected to the upper region 12h to pass and be returned to the upper region 12h. [Industrial Applicability]

[0154] The present invention can be applied not only to sugarcane harvesters, but also to other agricultural work vehicles such as head-feeding combines and conventional combines, and construction work vehicles such as backhoes and front loaders, and can also be applied to work vehicles equipped with crawler-type running gear (not shown) instead of the rear wheels 2. [Explanation of symbols]

[0155] 2 Rear wheels (running gear) 3 Reaping section (work device) 4. First transport device (working device) 5. Sorting equipment (work equipment) 6 Second transport device (working device) (transport device) 8 Hydrostatic continuously variable transmission (work equipment) 8c Charge pump (hydraulic pump) 11 First tank (first storage section) 11g Partition material 11h 1st area 11j 2nd area 12 Second tank (second storage section) 12b Right wall (wall) 12c Left wall (wall) 12g wall material 12h upper area 12j lower area 12k communication path 12m fuel station 14 Strainer 15 filters 16 Connecting oil passage 17 Steering device (working device) 18 Control valve unit (working device) 19 Blower fan (working equipment) 23 Hydraulic pump 24 Hydraulic pump 25 Hydraulic pump 26 Hydraulic pump 27 Hydraulic pump 28 Hydraulic Pump 29 Hydraulic Pump 31 Upper and lower pipe members 32 Horizontal pipe member 33 Oil passage (first supply oil passage) 34 Oil passage (first supply oil passage) 35 Oil passage (first supply oil passage) 36 Oil passage (second supply oil passage) 37 Oil passage (first supply oil passage) 38 Oil passage (second supply oil passage) 39 Oil passage (first supply oil passage) 40 Oil passage (second supply oil passage) 43 Oil passage (second return oil passage) 44 Oil passage (second return oil passage) 45 Oil passage (second return oil passage) 46 Oil passage (second return oil passage) 47 Oil passage (first return oil passage) 48 Oil passage (first return oil passage) 49 Oil passage (second return oil passage) 50 Oil passage (second return oil passage) 51 Oil passage (second return oil passage) 52 Oil passage (second return oil passage)

Claims

1. The hydraulic power plant is provided with a plurality of working devices, a first reservoir capable of storing hydraulic oil, a second reservoir capable of storing hydraulic oil, and a hydraulic pump that supplies hydraulic oil to the working devices, The second storage section is provided at a position higher than an upper end of the first storage section, The work vehicle is provided with a connecting oil passage that connects the first storage section and the second storage section and allows hydraulic oil to communicate.

2. 2. The work vehicle according to claim 1, wherein the connecting oil passage connects an upper portion of the first reservoir section to a lower portion of the second reservoir section.

3. the second storage section has a wall member that divides the interior of the second storage section into an upper region and a lower region, and a communication passage that connects the upper region and the lower region, The work vehicle according to claim 2 , wherein the connecting oil passage is connected to the lower region.

4. the communication passage is provided near one of two pairs of wall portions facing each other in the second storage section, 4. A work vehicle according to claim 3, wherein the portion of the connecting oil passage connected to the lower region is provided near the other of the two pairs of wall portions facing each other in the second storage section.

5. 2. The work vehicle according to claim 1, further comprising an oil supply section that can supply hydraulic oil to the second reservoir section.

6. a first oil supply passage that supplies the hydraulic oil in the first reservoir to some of the working devices; The work vehicle according to claim 1 , further comprising a second oil supply passage that supplies hydraulic oil from the second reservoir to some of the plurality of work devices.

7. the second storage section has a wall member that divides the interior of the second storage section into an upper region and a lower region, and a communication passage that connects the upper region and the lower region, The work vehicle according to claim 6, wherein the second oil supply passage is connected to the upper region.

8. a first return oil passage that returns hydraulic oil discharged from some of the working devices among the plurality of working devices to the first reservoir; The work vehicle according to claim 1 , further comprising a second return oil passage for returning hydraulic oil discharged from some of the plurality of work devices to the second reservoir.

9. a first oil supply passage that supplies the hydraulic oil in the first reservoir to some of the working devices; a second oil supply passage that supplies the hydraulic oil in the second reservoir to some of the working devices; a first return oil passage that returns hydraulic oil discharged from some of the working devices among the plurality of working devices to the first reservoir; a second return oil passage that returns hydraulic oil discharged from some of the working devices among the plurality of working devices to the second reservoir; 2. The work vehicle according to claim 1, further comprising: a work device that receives hydraulic oil from the first supply oil passage and outputs the hydraulic oil to the first return oil passage; and a work device that receives hydraulic oil from the second supply oil passage and outputs the hydraulic oil to the second return oil passage.

10. The first storage section has a partition member that divides the inside of the first storage section into a first region and a second region, and a strainer through which the hydraulic oil in the second region can pass and enter the first region, the first oil supply passage is connected to the first region, The work vehicle according to claim 9, wherein the connecting oil passage and the first return oil passage are connected to the second area.

11. The first region is provided at an upper portion inside the first storage portion, The work vehicle according to claim 10, wherein the strainer is connected to a lower portion of the first area and extends downward from the lower portion of the first area.

12. The first region is provided on one side in the left-right direction or one side in the front-rear direction at an upper portion inside the first storage portion, The work vehicle according to claim 10, wherein the connecting oil passage is connected to a portion of the second region adjacent to the first region.

13. 10. The work vehicle according to claim 9, further comprising the work device that receives hydraulic oil from the first oil supply passage and outputs hydraulic oil to the second oil return passage.

14. 10. The work vehicle according to claim 9, further comprising the work device that receives hydraulic oil from the second oil supply passage and outputs hydraulic oil to the first oil return passage.

15. the second storage section has a wall member that divides the interior of the second storage section into an upper region and a lower region, and a communication passage that connects the upper region and the lower region, The work vehicle according to any one of claims 8 to 14, further comprising the second return oil passage connected to the lower region.

16. An upper and lower pipe member is provided across the upper portion of the second storage portion and the lower portion, the upper pipe member passing through the upper portion and connecting the upper portion and the lower portion, The work vehicle according to claim 15, wherein the second return oil passage connected to the lower region is connected to the upper and lower pipe members.

17. the communication passage is provided near one of two pairs of wall portions facing each other in the second storage section, a horizontal pipe member extending from one of the two pairs of wall portions facing each other in the second storage section across the communication passage to the lower region; The work vehicle according to claim 15, wherein the second return oil passage connected to the lower region is connected to the horizontal pipe member.

18. the second storage section has a wall member that divides the interior of the second storage section into an upper region and a lower region, and a communication passage that connects the upper region and the lower region, the second return oil passage connected to the upper region is included; A work vehicle as described in any one of claims 8 to 14, further comprising a filter that allows hydraulic oil in the second return oil passage connected to the upper region to be passed through and returned to the upper region.

19. 2. The work vehicle according to claim 1, wherein the work device includes a hydrostatic continuously variable transmission that drives the traveling device.

20. 2. The work vehicle according to claim 1, wherein the work device includes a transport device for transporting and discharging the material to be processed to the outside.

Images