Sugar cane harvester

Abstract

To provide a sugar cane harvester which can simplify the structure of a supply system for work fluid related to a hydraulic steering device.SOLUTION: A sugar cane harvester includes: a hydraulic steering device 20 for steering a front wheel; and a steering manipulator 30 for manipulating a hydraulic steering device 20. An upper cutting device provided above a harvesting part for cutting an upper part of crop in a field, and a cutting hydraulic motor 27 for driving the upper cutting device are provided. The sugar cane harvester also includes: a supply oil path 85 in which work fluid in the hydraulic pump 49 is supplied; a steering supply oil path 40 branched from the supply oil path 85 and supplying work fluid to the hydraulic steering device 20; and a cutting drive supply oil path 37 branched from the supply oil path 85 and supplying work fluid to the cutting hydraulic motor 27.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a front wheel steering arrangement for a sugarcane harvester. [Background technology]

[0002] As disclosed in Patent Document 1, a sugarcane harvester is provided with a hydraulic steering device for steering the front wheels, and hydraulic oil from a hydraulic pump is supplied to the hydraulic steering device as a power source. A control handle (equivalent to a steering tool) is provided for operating the hydraulic steering device, and when an operator on board the aircraft operates the control handle, the hydraulic steering device is activated and the front wheels are steered by the hydraulic steering device. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2022-101177 A (see Figures 14 and 15) Summary of the Invention [Problem to be solved by the invention]

[0004] In addition to the hydraulic steering device, a sugarcane harvester is provided with a number of hydraulically operated working devices and hydraulic pumps, so there is room for improvement in terms of simplifying the structure of the hydraulic oil supply system.

[0005] An object of the present invention is to simplify the structure of a hydraulic oil supply system associated with a hydraulic steering device in a sugarcane harvester. [Means for solving the problem]

[0006] The sugarcane harvester of the present invention is equipped with a body having right and left front wheels and a cutting unit that cuts crops in a field, a hydraulic steering device that steers the front wheels, a steering operating tool that is manually operated to operate the hydraulic steering device, an upper cutting device that is provided above the cutting unit and cuts the upper parts of crops in the field, and a cutting hydraulic motor that drives the upper cutting device, a hydraulic pump, a supply oil passage to which hydraulic oil for the hydraulic pump is supplied, a steering supply oil passage that branches off from the supply oil passage and supplies hydraulic oil to the hydraulic steering device, and a cutting drive supply oil passage that branches off from the supply oil passage and supplies hydraulic oil to the cutting hydraulic motor.

[0007] In a sugarcane harvester, an upper cutting device is provided above the cutting unit, and the upper part of the crop (such as the upper leaves) is cut by the upper cutting device in parallel with the cutting of the crop by the cutting unit. The upper cutting device is driven by a cutting hydraulic motor.

[0008] According to the present invention, hydraulic oil from the hydraulic pump is supplied from the supply oil passage through the steering supply oil passage to the hydraulic steering device, and the hydraulic steering device is operated by operating the steering tool. Hydraulic oil from the hydraulic pump is supplied from the supply oil passage through the cutting drive supply oil passage to the cutting hydraulic motor, and the cutting hydraulic motor (upper cutting device) is operated. As a result, the hydraulic pump is shared as the power source for both the hydraulic steering device and the cutting hydraulic motor (upper cutting device), which makes it possible to reduce the number of hydraulic pumps and simplify the structure of the hydraulic oil supply system related to the hydraulic steering device.

[0009] In the present invention, it is preferable that a flow priority valve is provided in the supply oil passage, the steering supply oil passage and the cutting drive supply oil passage are connected to the flow priority valve, the control flow of the flow priority valve is supplied to the steering supply oil passage, and the excess flow of the flow priority valve is supplied to the cutting drive supply oil passage.

[0010] In sugarcane harvesters, the flow rate of hydraulic oil required to operate the hydraulic steering device is not very high. Since the hydraulic steering device requires high operational accuracy, it is preferable to supply a constant flow rate of hydraulic oil to the hydraulic steering device in order to ensure the operational accuracy of the hydraulic steering device.

[0011] Since the upper cutting device cuts the upper parts of crops in the field (upper leaves, etc.), it is sufficient that a flow rate of hydraulic oil sufficient to drive the upper cutting device is supplied to the cutting hydraulic motor; even if a flow rate of hydraulic oil greater than this is supplied to the cutting hydraulic motor, the cutting hydraulic motor will drive the upper cutting device without any problems.

[0012] According to the present invention, hydraulic oil for a hydraulic pump is supplied from a supply oil passage to a flow priority valve, a control flow of the flow priority valve is supplied to a steering supply oil passage, and an excess flow of the flow priority valve is supplied to a cutting drive supply oil passage. Even if the flow rate of hydraulic oil from the hydraulic pump changes depending on the driving state of the hydraulic pump, the control flow of the flow priority valve is supplied to the steering supply oil passage, so a constant flow rate of hydraulic oil is supplied to the hydraulic steering device, ensuring the operating accuracy of the hydraulic steering device.

[0013] If the flow rate of hydraulic oil from the hydraulic pump changes, the flow rate of the excess flow from the flow priority valve also changes. In this case, as long as a flow rate of hydraulic oil sufficient to drive the upper cutting device is supplied to the cutting hydraulic motor, even if the flow rate of the excess flow from the flow priority valve changes, the operating speed of the cutting hydraulic motor only changes, and the upper cutting device can be driven by the cutting hydraulic motor without any problems.

[0014] As a result, the flow priority valve is provided in accordance with the characteristics of the hydraulic steering device and the characteristics of the upper cutting device, so that the hydraulic steering device and the upper cutting device can be operated smoothly.

[0015] In the present invention, it is preferable that a cutting drive control valve be provided in the cutting drive supply oil passage, and have a forward rotation position in which the hydraulic oil in the cutting drive supply oil passage is supplied in the forward direction to operate the cutting hydraulic motor in the forward direction, a reverse rotation position in which the hydraulic oil in the cutting drive supply oil passage is supplied in the reverse direction to operate the cutting hydraulic motor in the reverse direction, and a neutral position in which the hydraulic oil in the cutting drive supply oil passage is discharged to stop the upper cutting device.

[0016] According to the present invention, in normal operation, the cutting drive control valve is operated to the normal rotation position, so that the cutting hydraulic motor operates in the normal rotation direction, and the upper part of the crop in the field is cut by the upper cutting device. When maintenance work on the upper cutting device is performed, the cutting drive control valve is operated to the neutral position, which stops the cutting hydraulic motor (upper cutting device), allowing maintenance work on the upper cutting device to be performed without any problems. If the upper cutting device becomes clogged with cutting material, the cutting drive control valve is operated to the reverse position, causing the cutting hydraulic motor (upper cutting device) to operate in reverse, making it easier to clear the clog in the upper cutting device. This allows for maintenance work on the upper cutting device and clearing blockages in the cut material, thereby improving the operability of the sugarcane harvester.

[0017] In the present invention, it is preferable to provide a cutting lifting cylinder that raises and lowers the upper cutting device, a hydraulic pump separate from the hydraulic pump, and a cutting lifting control valve that supplies and discharges hydraulic oil from the separate hydraulic pump to the cutting lifting cylinder, thereby extending and contracting the cutting lifting cylinder.

[0018] In sugarcane harvesters, the top cutting device must be set to an appropriate height depending on the height of the crop in the field. According to the present invention, a cutting lift cylinder for lifting and lowering the upper cutting device and a cutting lift control valve are provided, and hydraulic oil from a hydraulic pump separate from the hydraulic motor that supplies hydraulic oil to the hydraulic steering device and the cutting hydraulic motor is supplied to the cutting lift control valve.

[0019] As a result, the hydraulic steering device, the cutting hydraulic motor, and the cutting lifting cylinder operate independently of each other, so that the hydraulic steering device, the cutting hydraulic motor, and the cutting lifting cylinder can operate appropriately with little influence on each other. [Brief explanation of the drawings]

[0020] [Figure 1] FIG. 2 is a left side view of the sugarcane harvester. [Figure 2] FIG. [Figure 3] FIG. [Figure 4] FIG. 2 is a schematic diagram showing the entire hydraulic circuit. [Figure 5] FIG. 2 is a diagram illustrating the vicinity of a switching valve and an unloading valve in a hydraulic circuit. [Figure 6] 10A and 10B are diagrams illustrating an outline of the lifting and lowering operations of the right and left front wheels. DETAILED DESCRIPTION OF THE INVENTION

[0021] Figures 1 to 6 show a sugarcane harvester, and in Figures 1 to 6, F indicates the forward direction, B indicates the backward direction, U indicates the upward direction, D indicates the downward direction, R indicates the rightward direction, and L indicates the leftward direction.

[0022] (Overall configuration of sugarcane harvester) As shown in Figure 1, the reaping unit 3 and the first conveying device 4 are connected to form the machine body 10, and the first conveying device 4 extends diagonally upward and rearward from the rear of the reaping unit 3.

[0023] A right front wheel 1 and a left front wheel 2 are provided on the right and left parts of the reaping unit 3. An upper cutting device 7 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 8 are provided on the lower part of the rear part of the first conveying device 4, and the machine body 10 is supported by the front wheels 1, 2 and the rear wheels 8.

[0024] The sorting device 5 is provided in the vertical direction at the rear of the first conveying device 4, and the second conveying device 6 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 19 is provided at the top of the front part of the first conveying device 4.

[0025] (Configuration of reaping unit 3) As shown in FIGS. 1 and 2, the reaping unit 3 has right and left cutters 11, 12, right dividers 13, 14, left dividers 15, 16, a tipping roller 17, and right and left side wall units 18.

[0026] Right and left side wall portions 18 are provided along the front-to-rear direction, and the rear portions of the side wall portions 18 are connected to the front portion of the first conveying device 4. A right front wheel 1 is provided on the right side wall portion 18, and a left front wheel 2 is provided on the left side wall portion 18.

[0027] The right and left cutters 11, 12 are arranged side by side in the left-right direction at the bottom of the rear part between the right and left side wall parts 18. The laying roller 17 is arranged at the top of the front part between the right and left side wall parts 18, and is driven to rotate by a hydraulic motor 28 around an axis P7 that extends in the left-right direction.

[0028] The right dividers 13, 14 are provided in front of the right lateral wall portion 18. The right dividers 13, 14 are driven to rotate by a hydraulic motor 24 around axes P3, P4 along the longitudinal direction of the dividers 13, 14.

[0029] The left dividers 15, 16 are provided in front of the left lateral wall portion 18. The left dividers 15, 16 are driven to rotate by a hydraulic motor 24 around axes P5, P6 along the longitudinal direction of the dividers 15, 16.

[0030] (Configuration of right and left cutters 11, 12) As shown in FIGS. 2 and 3, the right and left cutters 11 and 12 have shaft portions 11a and 12a, disk portions 11b and 12b, and cutting blades 11c and 12c.

[0031] A transmission case 29 is connected across the right and left side wall portions 18. Shaft portions 11a, 12a are attached to the transmission case 29 and extend downward so as to be rotatable around axes P1, P2 that extend in the up-down direction. Disc portions 11b, 12b are attached to the lower portions of the shaft portions 11a, 12a, and multiple cutting blades 11c, 12c are attached to the outer peripheries of the disc portions 11b, 12b.

[0032] A hydraulic motor 34 is attached to the transmission case 29, and the power of the hydraulic motor 34 is transmitted to the shafts 11a and 12a via a transmission gear (not shown) inside the transmission case 29. The hydraulic motor 34 rotates the cutter 11 counterclockwise in FIG. 2, and the cutter 12 clockwise in FIG. 2.

[0033] (Sugarcane harvester in operation) As shown in Figures 1 and 2, as the machine body 10 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 separated into crops to be harvested and other crops by the right dividers 13, 14 and the left dividers 15, 16, and the crops to be harvested are guided between the right and left dividers 13, 15.

[0034] The crops guided between the right and left dividers 13, 15 are guided between the right and left side walls 18 while being tilted forward by the tilting rollers 17, and the bases of the crops are cut by the cutters 11, 12.

[0035] The crops with their bases cut are supplied from the base to the first conveying device 4, 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 then supplied to the top of the sorting device 5.

[0036] 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 (not shown) is provided at the top of the sorting device 5, and the sorting fan generates sorting wind directed upward 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.

[0037] 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.

[0038] (Overview of hydraulic systems in sugarcane harvesters) As shown in Figure 4, the drive case 38 is attached to the engine 19, and the hydraulic pumps 39, 44, 48, 49, 51, 52, 53, and 58 are provided in the drive case 38. The power of the engine 19 is transmitted to the hydraulic pumps 39, 44, 48, 49, 51, 52, 53, and 58 via a gear transmission system inside the drive case 38, thereby driving the hydraulic pumps 39, 44, 48, 49, 51, 52, 53, and 58.

[0039] Hydraulic oil from the hydraulic pump 39 is supplied to the reaping unit 3 and then to the hydraulic motors 24, 28, and 34, which rotate and drive the cutters 11 and 12, the right and left dividers 13-16, and the tipping roller 17. Hydraulic oil from the hydraulic pump 44 is supplied to the first conveying device 4, which operates the first conveying device 4. Hydraulic oil from the hydraulic pump 48 is supplied to the sorting device 5, which operates the sorting fan of the sorting device 5.

[0040] As will be described later, a hydraulic steering device 20 is provided to steer the front wheels 1, 2. Hydraulic oil from a hydraulic pump 49 is supplied to the upper cutting device 7 and the hydraulic steering device 20, causing the upper cutting device 7 and the hydraulic steering device 20 to operate.

[0041] A blower fan (not shown) is provided to supply cooling air to a radiator (not shown) and an oil cooler (not shown). Hydraulic oil from a hydraulic pump 51 is supplied to the blower fan, causing the blower fan to operate.

[0042] As will be described later, a control valve unit 59 is provided, and hydraulic oil from the hydraulic pump 52 is supplied to the control valve unit 59. Hydraulic oil from the hydraulic pump 53 is supplied to the second transfer device 6, causing the second transfer device 6 to operate.

[0043] A hydrostatic continuously variable transmission (not shown) is provided. The continuously variable transmission has a travel pump 54, a travel motor (not shown), and a charge pump 55. The travel pump 54 and the charge pump 55 are provided in the drive case 38 and are driven by the power of the engine 19.

[0044] A travel motor is provided in a transmission case (not shown) on which rear wheels 8 (see FIG. 1) are mounted. Hydraulic oil from a travel pump 54 is supplied to the travel motor, which operates to drive the rear wheels 8. A hydraulic pump 58 circulates lubricating oil in the drive case 38 and the transmission case through an oil cooler (not shown), which cools the lubricating oil in the drive case 38 and the transmission case.

[0045] (Configuration of control valve unit 59) - 1 4 and 5, the control valve unit 59 has a control valve 46, a control valve 76, a control valve 41, a control valve 42, a control valve 43, a control valve 45, a control valve 77, a switching valve 68, an unloading valve 69, etc. An oil passage 71 extends from the hydraulic pump 52 and is connected to the control valve unit 59 and is also connected to the switching valve 68.

[0046] In the control valve unit 59, the oil passage 36 extends from the switching valve 68 and is connected to the control valve 46. The oil passage 72 extends from the switching valve 68. The oil passage 66 branches off from the oil passage 72 and is connected to the control valve 76. An oil passage 31 branches off from the oil passage 72 and is connected to the control valve 41. An oil passage 32 branches off from the oil passage 72 and is connected to the control valve . An oil passage 33 branches off from the oil passage 72 and is connected to the control valve 43. An oil passage 35 branches off from the oil passage 72 and is connected to the control valve 45. An oil passage 67 branches off from the oil passage 72 and is connected to a control valve 77 .

[0047] As a result, the hydraulic oil from the hydraulic pump 52 is supplied in parallel from the oil passage 71 to the control valves 46, 76, 41, 42, 43, 45, and 77 through the switching valve 68, the oil passage 72, and the oil passages 36, 66, 31, 32, 33, 35, and 67.

[0048] (Configuration of control valve unit 59)-2 As shown in Fig. 4, a hydraulic cylinder 26 is provided to raise and lower the second transfer device 6 (see Fig. 1) with the front part of the second transfer device 6 as a fulcrum. Hydraulic oil in an oil passage 36 is supplied to and discharged from a control valve 46 to the hydraulic cylinder 26, causing the hydraulic cylinder 26 to expand and contract, thereby raising and lowering the second transfer device 6.

[0049] A hydraulic cylinder 56 is provided that uses the front part of the second transfer device 6 (see FIG. 1) as a fulcrum to change the direction of the second transfer device 6 to the right or left. Hydraulic oil in an oil passage 66 is supplied to or discharged from a control valve 76 to the hydraulic cylinder 56, causing the hydraulic cylinder 56 to expand or contract, changing the direction of the second transfer device 6 to the right or left.

[0050] A hydraulic cylinder 21 is provided to raise and lower the right front wheel 1 (see FIGS. 1, 2, and 3) relative to the machine body 10 (cutting unit 3). Hydraulic oil in an oil passage 31 is supplied to and discharged from a control valve 41 to the hydraulic cylinder 21, causing the hydraulic cylinder 21 to expand and contract, thereby raising and lowering the right front wheel 1.

[0051] A hydraulic cylinder 22 is provided to raise and lower the left front wheel 2 (see FIGS. 1, 2, and 3) relative to the machine body 10 (cutting unit 3). Hydraulic oil in an oil passage 32 is supplied to and discharged from a control valve 42 to the hydraulic cylinder 22, causing the hydraulic cylinder 22 to expand and contract, thereby raising and lowering the left front wheel 2.

[0052] The right dividers 13, 14 (see Figures 1 and 2) are attached to the front of the right side wall portion 18 so that they can be raised and lowered, and are provided with a hydraulic cylinder 23 that raises and lowers the right dividers 13, 14. Hydraulic oil in an oil passage 33 is supplied to and discharged from a control valve 43 to the hydraulic cylinder 23, causing the hydraulic cylinder 23 to expand and contract, thereby raising and lowering the right dividers 13, 14.

[0053] The left dividers 15, 16 (see Figures 1 and 2) are attached to the front of the left lateral wall portion 18 so that they can be raised and lowered, and are provided with a hydraulic cylinder 25 that raises and lowers the left dividers 15, 16. Hydraulic oil in an oil passage 35 is supplied to and discharged from a control valve 45 to the hydraulic cylinder 25, causing the hydraulic cylinder 25 to expand and contract, thereby raising and lowering the left dividers 15, 16.

[0054] The upper cutting device 7 (see FIG. 1) is attached to the reaping unit 3 so that it can be raised and lowered, and is provided with a hydraulic cylinder 57 that raises and lowers the upper cutting device 7. Hydraulic oil in an oil passage 67 is supplied to and discharged from a control valve 77 to the hydraulic cylinder 57, causing the hydraulic cylinder 57 to expand and contract, thereby raising and lowering the upper cutting device 7.

[0055] (Configuration of the switching valve 68) 5, the switching valve 68 is configured as a pilot-operated type, having a first position 68a, a second position 68b, and a spring 68c, and is biased to the second position 68b by the spring 68c. A pilot oil passage 73 is connected between the oil passage 36 and the first position 68a of the switching valve 68.

[0056] The control valve 46 has an up position 46a, a down position 46b, and a neutral position 46c. An oil passage 74 is connected between the control valve 46 and the hydraulic cylinder 26, and a pilot-operated check valve 75 is provided in the oil passage 74.

[0057] A pilot oil passage 78 is connected between the control valve 46 and the check valve 75. A pilot oil passage 79 branching from the pilot oil passage 78 and a pilot oil passage 80 branching from the oil passage 74 are connected to the check valve 82. A pilot oil passage 81 is connected between the second position 68b of the switching valve 68 and the check valve 82.

[0058] (Operation state of the switching valve 68) 5 shows a state in which the control valve 46 is operated to the neutral position 46c, and the oil passage 36 is blocked by the neutral position 46c of the control valve 46. In this state, the hydraulic oil from the hydraulic cylinder 26 is stopped by the check valve 75, and the hydraulic cylinder 26 is stopped.

[0059] With the control valve 46 operated to the neutral position 46c, the pilot hydraulic oil in the pilot oil passages 78 to 81 is discharged to the hydraulic oil tank 83 through the neutral position 46c of the control valve 46. The pilot hydraulic oil in the oil passage 36 is supplied to the first position 68a of the switching valve 68 through the pilot oil passage 73, and the switching valve 68 is operated to the first position 68a against the spring 68c.

[0060] As shown in Figures 4 and 5, when the switching valve 68 is operated to the first position 68a, the hydraulic oil in the oil passage 71 is supplied to the oil passage 72 through the switching valve 68 (first position 68a), and then supplied from the oil passage 72 to the oil passages 66, 31, 32, 33, 35, and 67 (control valves 76, 41, 42, 43, 45, and 77).

[0061] When the control valve 46 is operated to the raised position 46a, the pilot hydraulic oil in the oil passage 36 is supplied to the first position 68a of the switching valve 68 through the pilot oil passage 73, and the pilot hydraulic oil in the oil passage 36 is supplied to the second position 68b of the switching valve 68 through the control valve 46 (raised position 46a) and the pilot oil passages 80 and 81.

[0062] When the control valve 46 is operated to the lowered position 46b, the pilot hydraulic oil in the oil passage 36 is supplied to the first position 68a of the switching valve 68 through the pilot oil passage 73, and the pilot hydraulic oil in the oil passage 36 is supplied to the second position 68b of the switching valve 68 through the control valve 46 (lowered position 46b) and the pilot oil passages 78, 79, and 81.

[0063] When the control valve 46 is operated to the raised position 46a and the lowered position 46b, the pilot hydraulic oil supplied to the first position 68a of the switching valve 68 and the pilot hydraulic oil supplied to the second position 68b of the switching valve 68 are balanced, but the switching valve 68 is operated to the second position 68b by the spring 68c that biases the switching valve 68 to the second position 68b.

[0064] When the control valve 46 is operated to the raised position 46a and the switching valve 68 is operated to the second position 68b, the hydraulic oil in the oil passage 71 is supplied to the oil passage 36 through the switching valve 68 (second position 68b), and then supplied to the hydraulic cylinder 26 through the control valve 46 (raised position 46a), the oil passage 74 and the check valve 75, and the second conveying device 6 is raised by the hydraulic cylinder 26. The hydraulic oil in the oil passage 71 is not supplied to the oil passage 72, and is not supplied to the oil passages 66, 31, 32, 33, 35, and 67 (control valves 76, 41, 42, 43, 45, and 77).

[0065] When the control valve 46 is operated to the lowered position 46b and the switching valve 68 is operated to the second position 68b, the hydraulic oil in the oil passage 71 is supplied to the oil passage 36 through the switching valve 68 (second position 68b), and is supplied to the check valve 75 through the control valve 46 (lowered position 46b) and the pilot oil passage 78, causing the check valve 75 to be opened.

[0066] With the control valve 46 operated to the lowered position 46b and the switching valve 68 operated to the second position 68b, the hydraulic oil in the hydraulic cylinder 26 is discharged through the oil passage 74, the check valve 75, and the control valve 46 (lowered position 46b) to the hydraulic oil tank 83, and the second conveying device 6 is lowered by the hydraulic cylinder 26. The hydraulic oil in the oil passage 71 is not supplied to the oil passage 72, and is not supplied to the oil passages 66, 31, 32, 33, 35, and 67 (control valves 76, 41, 42, 43, 45, and 77).

[0067] (Configuration of unloading valve 69) 5, an unloading valve 69 is connected to a portion of the oil passage 72 between the switching valve 68 and the oil passage 66. The unloading valve 69 has a shutoff position 69a and an unloading position 69b, and is manually operated.

[0068] 5 shows a state in which the unloading valve 69 is operated to the shutoff position 69a. In this state, when the switching valve 68 is operated to the first position 68a, the hydraulic oil in the oil passage 71 is supplied from the switching valve 68 (first position 68a) to the oil passage 72 and the oil passages 66, 31, 32, 33, 35, and 67 (control valves 76, 41, 42, 43, 45, and 77).

[0069] When the unloading valve 69 is operated to the unloading position 69b, even if the switching valve 68 is operated to the first position 68a, the hydraulic oil in the oil passage 72 is discharged to the hydraulic oil tank 83 and is not supplied to the oil passages 66, 31, 32, 33, 35, 67 (control valves 76, 41, 42, 43, 45, 77).

[0070] When the unloading valve 69 is operated to the unloading position 69b, the control valve 46 is operated to the raised position 46a and the lowered position 46b, thereby raising and lowering the second conveying device 6 and performing maintenance work on the second conveying device 6.

[0071] (Overview of the hydraulic system of the upper cutting device 7 and the hydraulic steering device 20) As shown in Fig. 4, there is provided a hydraulic steering device 20 that steers the front wheels 1 and 2. The upper cutting device 7 is configured to be provided with two sets of disc cutters (not shown) similar to the cutters 11 and 12, and is provided with a hydraulic motor 27 that rotates the disc cutters of the upper cutting device 7, and a control valve 47 that supplies and discharges hydraulic oil to and from the hydraulic motor 27.

[0072] A flow priority valve 84 is provided, and an oil passage 85 extends from the hydraulic pump 49 and is connected to the flow priority valve 84. An oil passage 40 extends from the flow priority valve 84 and is connected to the hydraulic steering device 20, and an oil passage 37 extends from the flow priority valve 84 and is connected to the control valve 47.

[0073] When hydraulic oil from the hydraulic pump 49 is supplied to the flow priority valve 84 through the oil passage 85, the controlled flow of the flow priority valve 84 is supplied to the oil passage 40 and then to the hydraulic steering device 20. The surplus flow of the flow priority valve 84 is supplied to the oil passage 37 and then to the upper cutting device 7 (the control valve 47 and the hydraulic motor 27).

[0074] The control valve 47 has a forward rotation position 47a, a reverse rotation position 47b, and a neutral position 47c. When the control valve 47 is operated to the forward rotation position 47a, the hydraulic oil in the oil passage 37 is supplied in the forward direction from the control valve 47 (forward rotation position 47a) to the hydraulic motor 27, and the hydraulic motor 27 operates in the forward direction to drive the upper cutting device 7 in the forward direction.

[0075] When the control valve 47 is operated to the reverse position 47b, the hydraulic oil in the oil passage 37 is supplied in the reverse direction from the control valve 47 (reverse position 47b) to the hydraulic motor 27, causing the hydraulic motor 27 to operate in the reverse direction and drive the upper cutting device 7 in the reverse direction.

[0076] When the control valve 47 is operated to the neutral position 47c, the hydraulic oil in the oil passage 37 is discharged from the control valve 47 (neutral position 47c) to the hydraulic oil tank 83, and the hydraulic motor 27 and the upper cutting device 7 stop.

[0077] If crops become stuck in the upper cutting device 7, the control valve 47 is operated to the reverse position 47b, and the upper cutting device 7 is driven in reverse to clear the jam. The control valve 47 is operated to the neutral position 47c, and the hydraulic motor 27 and the upper cutting device 7 are stopped, allowing maintenance work on the upper cutting device 7 to be performed.

[0078] (Configuration of lifting and lowering operation of front wheels 1 and 2 by hydraulic cylinders 21 and 22) 2 and 3, right and left support arms 61 are provided on the lower parts of the right and left side wall portions 18 so as to be able to swing up and down about an axis P8 along the front-to-rear direction. Right and left brackets 62 are provided on the upper parts of the right and left side wall portions 18.

[0079] The hydraulic cylinders 21, 22 (see FIG. 4) have main bodies 21a, 22a and pistons 21b, 22b, and are configured as double-acting cylinders, with knuckle arms 21c, 22c attached to the upper parts of the main bodies 21a, 22a.

[0080] The lower parts of the main bodies 21a, 21a of the hydraulic cylinders 21, 22 are rotatably attached to a support part 61a at the end of a support arm 61 around vertical axes P21, P22. The upper parts of the pistons 21b, 22b of the hydraulic cylinders 21, 22 are attached to a bracket 62. The front wheels 1, 2 are rotatably attached to an axle part 63 connected to the main bodies 21a, 22a of the hydraulic cylinders 21, 22.

[0081] The right front wheel 1 is raised and lowered relative to the machine body 10 (the reaping unit 3) as the hydraulic cylinder 21 extends and retracts. The left front wheel 2 is raised and lowered relative to the machine body 10 (the reaping unit 3) as the hydraulic cylinder 22 extends and retracts.

[0082] When the front wheels 1, 2 and rear wheels 8 are in contact with the field, the hydraulic cylinders 21, 22 are extended and retracted, causing the machine body 10 (cutting unit 3) to be raised and lowered relative to the front wheels 1, 2, with the rear wheels 8 as the fulcrum, thereby changing the height of the cutters 11, 12 relative to the field (front wheels 1, 2).

[0083] (Configuration of hydraulic steering device 20) 3 and 4, the hydraulic steering device 20 has a control valve 50 and double-acting right and left hydraulic cylinders 60, 70. An oil passage 40 is connected to the control valve 50, and an oil passage 65 is connected to the oil chambers on the main body sides of the hydraulic cylinders 60, 70.

[0084] A support frame 64 is connected across the right and left side wall portions 18, and right and left brackets 64a are provided on the support frame 64. The right hydraulic cylinder 60 is attached to the right bracket 64a of the support frame 64 so as to be able to swing up and down, and is connected to the knuckle arm 21c of the right hydraulic cylinder 21. The left hydraulic cylinder 70 is attached to the left bracket 64a of the support frame 64 so as to be able to swing up and down, and is connected to the knuckle arm 22c of the left hydraulic cylinder 22.

[0085] A steering handle 30 is provided on the driving section 9 (see FIG. 1), and an operator of the driving section 9 manually operates the steering handle 30 to operate the control valve 50. By operating the control valve 50, hydraulic oil in the oil passage 40 is supplied to or discharged from the control valve 50 to the hydraulic cylinders 60, 70, and the front wheels 1, 2 are steered as described below.

[0086] When hydraulic oil from the control valve 50 is supplied to the oil chamber on the piston side of the right hydraulic cylinder 60, the right hydraulic cylinder 60 contracts. Accordingly, hydraulic oil from the oil chamber on the main body side of the right hydraulic cylinder 60 is supplied to the oil chamber on the main body side of the left hydraulic cylinder 70 through the oil passage 65, causing the left hydraulic cylinder 70 to extend.

[0087] As a result, the main bodies 21a, 22a of the hydraulic cylinders 21, 22 are rotated clockwise in plan view about the axes P21, P22 relative to the pistons 21b, 22b of the hydraulic cylinders 21, 22, and the front wheels 1, 2 are steered to the right.

[0088] When hydraulic oil from the control valve 50 is supplied to the oil chamber on the piston side of the left hydraulic cylinder 70, the left hydraulic cylinder 70 contracts. Accordingly, hydraulic oil from the oil chamber on the main body side of the left hydraulic cylinder 70 is supplied to the oil chamber on the main body side of the right hydraulic cylinder 60 through the oil passage 65, causing the right hydraulic cylinder 60 to extend.

[0089] As a result, the main bodies 21a, 22a of the hydraulic cylinders 21, 22 are rotated counterclockwise in plan view about the axes P21, P22 relative to the pistons 21b, 22b of the hydraulic cylinders 21, 22, and the front wheels 1, 2 are steered to the left.

[0090] (Configuration related to lift control and tilt control of front wheels 1 and 2) 6, a load sensor 87 is provided in an oil passage 86 that supplies hydraulic oil to the hydraulic motor 34 that rotates and drives the cutters 11, 12, and the detection value of the load sensor 87 is input to the control device 100. The load sensor 87 detects the pressure of the hydraulic oil in the oil passage 86 as the load applied to the hydraulic motor 34 and the cutters 11, 12.

[0091] Right and left height sensors 88 are provided to detect the vertical angle of the support arm 61 relative to the right and left side wall portions 18, and the detection values ​​of the right and left height sensors 88 are input to the control device 100.

[0092] The height sensor 88 detects the vertical angle of the support arm 61 relative to the side wall portion 18, thereby detecting the vertical positions of the front wheels 1, 2 relative to the machine body 10 (cutting unit 3), and thereby detecting the height of the cutters 11, 12 relative to the field. The control device 100 detects the average value of the detection values ​​of the right and left height sensors 88 as the height of the cutters 11, 12 relative to the field.

[0093] A dial-operated height setting unit 89 is provided in the driving unit 9 (see FIG. 1), and a signal from the height setting unit 89 is input to the control device 100. The height setting unit 89 sets a reference height, which will be described later, and the reference height can be changed arbitrarily by the operator manually operating the height setting unit 89.

[0094] An inclination sensor 90 that detects the inclination angle of the machine body 10 (cutting unit 3) in the left-right direction relative to the horizontal plane is provided on the cutter unit 3, and the detected value of the inclination sensor 90 is input to the control device 100.

[0095] A dial-operated tilt setting unit 91 is provided in the driving unit 9 (see FIG. 1), and a signal from the tilt setting unit 91 is input to the control device 100. The tilt setting unit 91 sets a set tilt angle, which will be described later, and the set tilt angle can be changed arbitrarily by an operator manually operating the tilt setting unit 91.

[0096] (Tilt control of front wheels 1 and 2) - 1 As shown in Fig. 6, the tilt control unit 102 is provided as software in the control device 100. Based on the tilt angle set by the tilt setting unit 91 and the detected value of the tilt sensor 90, the tilt control unit 102 operates the control valves 41, 42 (see Fig. 4) independently of each other, and operates the right and left hydraulic cylinders 21, 22 to extend and retract independently of each other, as described below.

[0097] When the machine body 10 moves forward on a horizontal field, the operator simply operates the inclination setting unit 91 to set the set inclination angle to horizontal. This causes the control valves 41, 42 to be operated independently, and the right and left hydraulic cylinders 21, 22 are extended or retracted, setting the right and left hydraulic cylinders 21, 22 to the same length.

[0098] When the machine body 10 is moving forward on a horizontal field, if the machine body 10 (cutting unit 3) tilts to the right or left due to unevenness in the field, the control valves 41, 42 are operated, the right and left hydraulic cylinders 21, 22 are extended and retracted, the right and left front wheels 1, 2 are raised and lowered, and the detection value of the tilt sensor 90 is maintained at the set tilt angle (horizontal).

[0099] (Tilt control of front wheels 1 and 2) - 2 As shown in Figure 6, when the field is tilted downward to the right (downward to the left) relative to the forward direction of the machine body 10, if the right and left hydraulic cylinders 21, 22 are the same length, the machine body 10 will assume a posture parallel to the field and a posture downward to the right (downward to the left) relative to the horizontal plane. However, the machine body 10 is likely to tilt further to the right (left) downwards due to its own weight, and the cutters 11, 12 may no longer be parallel to the field.

[0100] If the field is inclined downward to the right relative to the forward direction of the machine body 10, the operator simply operates the inclination setting unit 91 to set the set inclination angle to a value that slopes downward to the right relative to the horizontal plane (an inclination angle parallel to the field).

[0101] When the field is tilted downward to the right relative to the forward direction of the machine body 10, the right and left hydraulic cylinders 21, 22 are set to the same length, and when the machine body 10 (cutting unit 3) maintains a posture parallel to the field, the right and left hydraulic cylinders 21, 22 are maintained to be the same length.

[0102] In the above-described state, if the machine body 10 tilts further downward to the right, the control valve 41 extends the right hydraulic cylinder 21, lowering the right front wheel 1, and the control valve 42 contracts the left hydraulic cylinder 22, raising the left front wheel 2. This maintains the detection value of the tilt sensor 90 at the set tilt angle (a tilt angle parallel to the field).

[0103] If the field is inclined downward to the left relative to the forward direction of the machine body 10, the operator simply operates the inclination setting unit 91 to set the set inclination angle to a value that is downward to the left relative to the horizontal plane (an inclination angle parallel to the field).

[0104] When the field is tilted downward to the left relative to the forward direction of the machine body 10, the right and left hydraulic cylinders 21, 22 are set to the same length, and when the machine body 10 (cutting unit 3) maintains a posture parallel to the field, the right and left hydraulic cylinders 21, 22 are maintained to be the same length.

[0105] In the above-described state, if the machine body 10 further tilts downward to the left, the control valve 41 contracts the right hydraulic cylinder 21, raising the right front wheel 1, and the control valve 42 extends the left hydraulic cylinder 22, lowering the left front wheel 2. This maintains the detection value of the tilt sensor 90 at the set tilt angle (a tilt angle parallel to the field). As described above, the detection value of the tilt sensor 90 is maintained at the set tilt angle, and the cutters 11, 12 are maintained in a position parallel to the field.

[0106] (Tilt control of front wheels 1 and 2) - 3 6, there are extension and retraction limits for the right and left hydraulic cylinders 21, 22. The right and left height sensors 88 detect the lengths of the right and left hydraulic cylinders 21, 22 in addition to detecting the up-down positions of the front wheels 1, 2 relative to the machine body 10 (the reaping unit 3).Therefore, it can be determined from the detection values ​​of the right and left height sensors 88 whether the right and left hydraulic cylinders 21, 22 have reached their extension and retraction limits.

[0107] When the field is tilted downward to the right (downward to the left) relative to the forward direction of the machine body 10, the right and left hydraulic cylinders 21, 22 reach their extension and contraction limits, and the detection value of the tilt sensor 90 cannot be maintained at the set tilt angle (a tilt angle parallel to the field), creating the possibility that the cutters 11, 12 may come into contact with the field.

[0108] In this case, the control device 100 displays on the operation panel (not shown) of the driving unit 9 that the detected value of the tilt sensor 90 cannot be maintained at the set tilt angle (a tilt angle parallel to the field). When the operator checks the display on the operation panel of the driving unit 9, as will be described later, he or she can operate the height setting unit 89 to change the reference height to a slightly higher value to avoid contact between the cutters 11, 12 and the field. In this case, the configuration may be such that the reference height is automatically changed to a slightly higher value.

[0109] (Front wheel 1 and 2 lift control) 6, a lift control unit 101 is provided as software in the control device 100. The lift control unit 101 operates the control valves 41, 42 and extends or retracts the right and left hydraulic cylinders 21, 22 based on the reference height of the height setting unit 89, the detection values ​​of the right and left height sensors 88, and the detection value of the load sensor 87, as described below.

[0110] The average of the detection values ​​of the right and left height sensors 88 is detected as the height of the cutters 11, 12 relative to the field. The control valves 41, 42 are operated to extend and retract the right and left hydraulic cylinders 21, 22, and raise and lower the right and left front wheels 1, 2, so that the height of the cutters 11, 12 relative to the field is maintained at the reference height of the height setting unit 89. This allows the operator to operate the height setting unit 89 to arbitrarily change the height of the cutters 11, 12 relative to the field.

[0111] An upper set value and a lower set value that is lower than the upper set value are set in advance in the control device 100 with respect to the detected value of the load sensor 87 . When the detected value of the load sensor 87 is between the upper set value and the lower set value, as described above, the control valves 41, 42 are operated, the right and left hydraulic cylinders 21, 22 are extended or retracted, and the height of the cutters 11, 12 relative to the field is maintained at the reference height of the height setting unit 89.

[0112] When the detected value of the load sensor 87 becomes higher than the upper set value, it is determined that the cutters 11, 12 have come into contact with the field and the load on the hydraulic motor 34 and the cutters 11, 12 has increased.

[0113] When the above-mentioned state is reached, the control valves 41, 42 are operated, the right and left hydraulic cylinders 21, 22 are extended, the machine body 10 (cutting unit 3) is raised, and the cutters 11, 12 are raised from the reference height of the height setting unit 89.

[0114] After this, when the detected value of the load sensor 87 becomes lower than the upper set value, it is determined that the cutters 11, 12 have finished contacting the field, and the control valves 41, 42 are operated to stop the right and left hydraulic cylinders 21, 22. This keeps the cutters 11, 12 at a position higher than the reference height of the height setting unit 89.

[0115] Next, when the detected value of the load sensor 87 becomes lower than the lowering set value, it is determined that the load on the hydraulic motor 34 and the cutters 11, 12 has decreased. When this state is reached, the control valves 41, 42 are operated, the right and left hydraulic cylinders 21, 22 are contracted, and the cutters 11, 12 are lowered from a position higher than the reference height of the height setting unit 89.

[0116] When the detected value of the load sensor 87 falls between the upper set value and the lower set value, it is determined that the load on the hydraulic motor 34 and the cutters 11, 12 has returned to an appropriate value. As a result, the control valves 41, 42 are operated so that the height of the cutters 11, 12 relative to the field is maintained at the reference height of the height setting unit 89, and the right and left hydraulic cylinders 21, 22 return to a state in which they are extended and retracted.

[0117] (First Alternative Embodiment of the Invention) Instead of the flow priority valve 84, a flow dividing valve (not shown) that divides the hydraulic oil in the oil passage 85 equally and supplies it to the oil passages 37 and 40 may be provided.

[0118] (Second Alternative Embodiment of the Invention) The hydraulic cylinders 60, 70 may be eliminated, and the hydraulic steering device 20 may be configured as described below. The hydraulic steering device 20 is configured such that one steering cylinder (not shown) is connected across the knuckle arms 21c, 22c of the hydraulic cylinders 21, 22, and the steering cylinder extends and retracts when the steering handle 30 is operated, thereby steering the front wheels 1, 2.

[0119] (Third Alternative Embodiment of the Invention) The hydraulic cylinders 60, 70 may be eliminated, and the hydraulic steering device 20 may be configured as described below. A rack gear (not shown) is connected across the knuckle arms 21c, 22c of the hydraulic cylinders 21, 22, and a pinion gear (not shown) is engaged with the rack gear to slide the rack gear, and a rack-and-pinion steering mechanism (not shown) is provided in which the pinion gear is rotationally driven by a steering shaft (not shown) extending from the steering handle 30. The hydraulic steering device 20 is configured to operate as a power steering device that assists the operation of the steering wheel 30 .

[0120] (Fourth Alternative Embodiment of the Invention) A crawler type traveling device may be provided in place of the rear wheels 8, and the machine body 10 may be configured to be supported by the front wheels 1, 2 and the crawler type traveling device. The upper cutting device 7 may be configured as a clipper type instead of having a disc cutter.

[0121] (Correspondence to claims)-1 The steering handle 30 corresponds to the steering operation tool. The hydraulic motor 27 corresponds to the cutting hydraulic motor. The oil passage 85 corresponds to the oil supply passage. The oil passage 40 corresponds to the steering oil supply passage. The oil passage 37 corresponds to the cutting drive supply oil passage. The control valve 47 corresponds to the cutoff drive control valve. The hydraulic cylinder 57 corresponds to the cutting lifting cylinder. The control valve 77 corresponds to the cutting lift control valve.

[0122] (Correspondence to claims)-2 The machine is provided with a body 10 having right and left front wheels 1, 2 and a reaping unit 3 for reaping crops in a field. The vehicle is provided with a hydraulic steering device 20 for steering the front wheels 1, 2. A steering operation tool (steering wheel 30) is provided for manually operating the hydraulic steering device 20. An upper cutting device 7 is provided above the reaping unit 3 and cuts the upper portions of crops in the field. A cutting hydraulic motor (hydraulic motor 27) that drives the upper cutting device 7 is provided. A hydraulic pump 49 is provided.

[0123] An oil supply passage (oil passage 85) through which hydraulic oil for the hydraulic pump 49 is supplied is provided. A steering oil supply passage (oil passage 40) that branches off from the supply oil passage (oil passage 85) and supplies hydraulic oil to the hydraulic steering device 20 is provided. A cutting drive supply oil passage (oil passage 37) is provided, branching from the supply oil passage (oil passage 85) and supplying hydraulic oil to the cutting hydraulic motor (hydraulic motor 27).

[0124] (Correspondence to claims) - 3 A flow priority valve 84 is provided in the supply oil passage (oil passage 85). The steering supply oil passage (oil passage 40) and the cutting drive supply oil passage (oil passage 37) are connected to a flow priority valve 84. The control flow of the flow priority valve 84 is supplied to the steering supply oil passage (oil passage 40), and the surplus flow of the flow priority valve 84 is supplied to the cutting drive supply oil passage (oil passage 37).

[0125] (Correspondence to claims)-4 A cutting drive control valve (control valve 47) is provided in the cutting drive supply oil passage (oil passage 37), and has a forward rotation position 47a where the hydraulic oil in the cutting drive supply oil passage (oil passage 37) is supplied in the forward direction to operate the cutting hydraulic motor (hydraulic motor 27) in the forward direction, a reverse rotation position 47b where the hydraulic oil in the cutting drive supply oil passage (oil passage 37) is supplied in the reverse direction to operate the cutting hydraulic motor (hydraulic motor 27) in the reverse direction, and a neutral position 47c where the hydraulic oil in the cutting drive supply oil passage (oil passage 37) is discharged to stop the upper cutting device 7.

[0126] (Correspondence to claims) - 5 A cutting lifting cylinder (hydraulic cylinder 57) is provided to lift and lower the upper cutting device 7. A hydraulic pump 52 separate from the hydraulic pump 49 is provided. A cutting lift control valve (control valve 77) is provided which supplies and discharges hydraulic oil from another hydraulic pump 52 to the cutting lift cylinder (hydraulic cylinder 57) and causes the cutting lift cylinder (hydraulic cylinder 57) to extend and retract. [Industrial Applicability]

[0127] The present invention is applicable to sugarcane harvesters. [Explanation of symbols]

[0128] 1 front wheel 2 front wheels 3 Reaping part 7 Upper cutting device 10 aircraft 20 Hydraulic steering device 27 Hydraulic motor (cutting hydraulic motor) 30 Steering wheel (steering device) 37 Oil passage (cutting drive supply oil passage) 40 Oil passage (steering supply oil passage) 47 Control valve (cut-off drive control valve) 47a Forward rotation position 47b Reversed position 47c neutral position 49 Hydraulic Pump 52 Hydraulic pump 57 Hydraulic cylinder (cutting lifting cylinder) 77 Control valve (cutting lift control valve) 84 Flow Priority Valve 85 Oil passage (oil supply passage)

Claims

1. A machine body having right and left front wheels and a reaping unit that reaps crops in a field; a hydraulic steering device that steers the front wheels; a steering operation tool that is manually operated to operate the hydraulic steering device; An upper cutting device provided above the reaping unit that cuts the upper part of the crop in the field; a cutting hydraulic motor for driving the upper cutting device; A hydraulic pump; a supply oil passage through which hydraulic oil is supplied to the hydraulic pump; a steering oil supply passage branching from the oil supply passage and supplying hydraulic oil to the hydraulic steering device; a cutting drive supply oil passage branching from the supply oil passage and supplying hydraulic oil to the cutting hydraulic motor.

2. a flow priority valve provided in the supply oil passage; the steering oil supply passage and the cutting drive oil supply passage are connected to the flow priority valve; 2. The sugarcane harvester according to claim 1, wherein a control flow of the flow priority valve is supplied to the steering supply oil line, and an excess flow of the flow priority valve is supplied to the cutting drive supply oil line.

3. 2. The sugarcane harvester according to claim 1, further comprising a cutting drive control valve provided in the cutting drive supply oil passage, the cutting drive control valve having a forward rotation position for supplying hydraulic oil from the cutting drive supply oil passage in a forward direction to operate the cutting hydraulic motor in a forward direction, a reverse rotation position for supplying hydraulic oil from the cutting drive supply oil passage in a reverse direction to operate the cutting hydraulic motor in a reverse direction, and a neutral position for discharging hydraulic oil from the cutting drive supply oil passage to stop the upper cutting device.

4. a cutting lifting cylinder for lifting and lowering the upper cutting device; a hydraulic pump separate from the hydraulic pump; 2. The sugarcane harvester according to claim 1, further comprising a cutting lift control valve for supplying and discharging hydraulic oil from the hydraulic pump to the cutting lift cylinder to extend and retract the cutting lift cylinder.

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