WORKING EQUIPMENT USED FOR MOWING LAWN

Abstract

The invention relates to a working device for mowing grass equipped with moving wheels (2, 3) and a working device (4) for mowing grass, provided that the first electric motor (30) drives the working device (4), the second electric motor (40) drives the moving wheels (2, 3), the battery pack (50) stores the electrical energy to be supplied to the first electric motor (30) and the second electric motor (40), the monitoring device (72) monitors the charging status of the battery pack (50), which is located above the first electric motor (30) and the second electric motor (40), and the grass container (7) holds the mowed grass, which is located above the first electric motor (30) and the second electric motor (40), and the monitoring device (72). By placing the monitoring device (72) below the battery pack (50) and in front of the battery pack (50), the increase in the installation position of the grass container is limited, thanks to This provides the optimal working conditions with stable movement.

Description

Work vehicles

[0001] The present invention relates to a work vehicle for cutting grass.

[0002] A known work vehicle has a battery that stores electricity to supply to an electric motor that drives a grass-cutting implement and an electric motor that drives the rear wheels, and is located below and behind the steering unit, and a monitoring unit that monitors the battery's state of charge, etc., is provided above the battery (see Patent Document 1).

[0003] JP 2011-188789 A

[0004] However, in the method of Patent Document 1, the monitoring unit is installed above the battery, so if the grass collection container is installed higher, it needs to be moved upward to prevent contact with the monitoring unit, which raises the center of gravity and could cause lateral shaking during driving, reducing driving stability.

[0005] Therefore, the main problem to be solved by the present invention is to provide a work vehicle that has excellent running stability by suppressing the rise in the position where the grass collection container is attached.

[0006] The present invention, which has solved the above-mentioned problems, is as follows: That is, the present invention is a work vehicle provided with traveling wheels (2, 3) and a work device (4) for cutting grass, characterized in that it is provided with a first electric motor (30) that drives the work device (4) and a second electric motor (40) that drives the traveling wheels (2, 3), a battery (50) that stores power to be supplied to the first electric motor (30) and the second electric motor (40), a monitoring unit (72) that monitors the charge state of the battery (50) above the first electric motor (30) and the second electric motor (40), a grass collection container (7) that collects cut grass above the first electric motor (30) and the second electric motor (40) and the monitoring unit (72), and the monitoring unit (72) is provided below the battery (50) and in front of the battery (50).

[0007] According to the present invention, by suppressing the elevation of the position where the grass collection container is attached, it is possible to suppress lateral shaking during travel and maintain high travel stability of the work vehicle.

[0008] 1 is a perspective view of a work vehicle as viewed from the front left side; 2 is a perspective view of the front part of the electric motor compartment as viewed from the rear left side; 3 is a perspective view of the rear part of the electric motor compartment as viewed from the rear left side; 4 is a plan view of the electric motor; 5 is a perspective view of the electric motor as viewed from the rear left side; 6 is a plan view of the electric motor; 7 is a rear view of the electric motor; 8 is a perspective view of the battery as viewed from the rear left side; 9 is a plan view of the electric motor compartment with the battery mounted thereon; 10 is a plan view of the electric motor and an inverter device; 11 is a left side view of the electric motor and an inverter device; 12 is a transmission diagram of the output rotation of the electric motor; 13 is a left side view of the electric motor compartment; 14 is a perspective view of the electric motor compartment as viewed from the rear right side; 15 is an explanatory diagram of the flow path of water circulating through the electrical unit, etc.

[0009] As shown in FIG. 1 , the work vehicle has a pair of left and right front wheels 2 provided at the front lower portion of a body frame 1 , and a pair of left and right rear wheels 3 provided at the rear lower portion of the body frame 1 .

[0010] A working device 4 for cutting grass growing in the field is provided at the front of the body frame 1, a control unit 5 on which the operator sits is provided at the rear of the working device 4, a safety frame (ROPS) 6 for protecting the operator is provided at the rear of the control unit 5, a grass collection container 7 for storing the cut grass is provided at the rear of the safety frame 6, and an electric motor room 8 is provided below the grass collection container 7 in which a second electric motor 40 for driving the rear wheels 3, a battery 50, etc. are placed.

[0011] A steering column 10 that supports a steering wheel is provided in front of the driver's seat of the control section 5. A monitor that displays the output rotation speed of the second electric motor 40 and the like is provided at the top of the steering column 10, and the bottom is fixed to the front part of the floor.

[0012] A brake pedal 11 for reducing the rotation speed of the front wheels 2 is provided on the left side of the steering column 10 on the floor, and a speed change pedal 12 for increasing or decreasing the output rotation speed of the second electric motor 40 is provided on the right side.

[0013] The upper part of the front wheel 2 is covered with a fender 13, and the fender 13 located on the right side of the driver's seat is provided with a gear change lever 14 for operating a second inverter device 45 that increases or decreases the output rotation of the second electric motor 40.

[0014] The rear of the working device 4 and the front of the grass collection container 7 are connected by a chute 16 extending in the front-to-rear direction, and a blower 17 for exhausting air into the chute 16 is provided in the middle of the front-to-rear direction of the chute 16.

[0015] A pair of left and right link arms 18 are provided at the front of the left and right walls of the grass collection container 7. The front parts of the link arms 18 are fixed to the left and right parts of the safety frame 6 so as to be able to swing freely, and the safety frame 6 and the link arms 18 are connected by lifting parts 19 such as hydraulic cylinders, and the rear part of the bottom wall of the grass collection container 7 rests on a horizontal frame 21A of a support frame 21, which will be described later. This allows the grass collection container 7 to be raised and lowered by driving the lifting parts 19.

[0016] As shown in Figures 2 and 3, the front electric chamber 8A of the electric chamber 8 is provided with a first electric motor 30 for working that drives the working device 4 and a second electric motor 40 for driving that drives the front wheels 2, and the rear electric chamber 8B is provided with a battery 50 that stores electricity to be supplied to the first electric motor 30 etc.

[0017] In a plan view, the first electric motor 30 is provided to the left of the center line in the left-right direction of the vehicle frame 1, and the second electric motor 40 is provided to the right of the center line in the left-right direction of the vehicle frame 1. This reduces the weight difference between the weight applied to the left of the center line in the left-right direction of the vehicle frame 1 and the weight applied to the right of the center line in the left-right direction of the vehicle frame 1, thereby improving steering performance.

[0018] When viewed from the side, a support frame 20 extending upward from the body frame 1 is provided in the partition between the front electric chamber 8A and the rear electric chamber 8B, and a support frame 21 extending upward from the body frame 1 is provided at the rear end of the rear electric chamber 8B.

[0019] The support frame 20 is formed of a left vertical frame 20L extending upward from the middle of the left side of the body frame 1, a right vertical frame 20R extending upward from the middle of the right side of the body frame 1, and a horizontal frame 20A extending in the left-right direction connecting the upper parts of the left vertical frame 20L and the right vertical frame 20R.

[0020] The support frame 21 is formed of a left vertical frame 21L extending upward from the rear end of the left side of the body frame 1, a right vertical frame 21R extending upward from the rear end of the right side of the body frame 1, a horizontal frame 21A extending in the left-right direction connecting the upper parts of the left vertical frame 21L and the right vertical frame 21R, and a horizontal frame 21B extending in the left-right direction connecting the middle parts of the left vertical frame 21L and the right vertical frame 21R. The left part of the horizontal frame 21B extends further left than the left vertical frame 21L, and the right part extends further right than the right vertical frame 21R.

[0021] The middle portion of the left vertical frame 20L and the left end portion of the horizontal frame 21B are connected by a left front-rear frame 22L extending in the front-rear direction, and the middle portion of the right vertical frame 20R and the right end portion of the horizontal frame 21B are connected by a right front-rear frame 22R also extending in the front-rear direction. This allows the rear portion of the battery 50 to be located above the drive shaft 46 of the rear wheel 3, preventing the vehicle frame 1 from being significantly deformed.

[0022] The upper part of the left vertical frame 20L and the middle part of the left vertical frame 23L provided at the rear of the control unit 5 are connected by a left front-rear frame 24L extending in the fore-and-aft direction, and the upper part of the right vertical frame 20R of the support frame 20 and the middle part of the right vertical frame 23R provided at the rear of the control unit 5 are connected by a right front-rear frame 24R extending in the fore-and-aft direction.

[0023] 4, the longitudinal direction of the first electric motor 30 is aligned along the front-rear direction. The second electric motor 40 is aligned adjacent to the left side of the first electric motor 30, and the longitudinal direction of the second electric motor 40 is aligned along the front-rear direction.

[0024] A radiator 60 that cools the water that cools the first electric motor 30 and other components is provided on the outside of the left wall of the electric motor chamber 8, and a fan 61 that blows outside air toward the electric motor chamber 8 is provided between the radiator 60 and the first electric motor 30. A circular opening (not shown) is formed in the left wall of the electric motor chamber 8 at a location facing the fan 61. This makes it possible to suppress a temperature rise in the first electric motor 30 and other components, thereby preventing malfunctions of the first electric motor 30 and other components. The fan 61 can also be provided on the left side of the radiator 60.

[0025] An auxiliary battery 65 that stores power to be supplied to the monitor of the control unit 5 is provided on the outside of the part of the right wall of the electric motor compartment 8 that faces the radiator 60. This makes it possible to reduce the weight difference between the left and right parts of the work vehicle.

[0026] 5 to 7, the output shaft 30A of the first electric motor 30 is connected to a first reducer 31 provided below the first electric motor 30. The first output shaft 31A of the first reducer 31 extends forward and is connected to a work clutch 32 provided between the first reducer 31 and the transmission path of the work device 4.

[0027] An output shaft 40A of the second electric motor 40 is connected to a second reduction gear 41 provided in front of the second electric motor 40. A second output shaft 41A of the second reduction gear 41 extends forward, and an output shaft 41B extends rearward and is connected to a 4WD clutch 43 provided between the second reduction gear 41 and the transmission path of the rear wheels 3, which switches between front-wheel drive and four-wheel drive.

[0028] In rear view, the first electric motor 30 and the second electric motor 40 are disposed at the same height in the vertical direction. This allows the first electric motor 30 and the second electric motor 40 to be disposed in the lower part of the front electric motor chamber 8A, and ensures space above the first electric motor 30 and the second electric motor 40 for disposing a monitoring unit 72 that monitors the state of the battery 50.

[0029] 5 to 7 and the like show the first electric motor 30 and the second electric motor 40 of the same size, but the first electric motor 30 can be changed to an electric motor larger than the second electric motor 40. This allows the working device 4, which is constantly driven and subjected to a large load, to be driven smoothly.

[0030] As shown in Figure 8, the battery 50 is formed from four battery modules 50A. The upper parts of the four battery modules 50A are connected by a pair of left and right angle-shaped mounting frames 51 that are spaced a predetermined distance apart in the left-right direction and extend in the front-rear direction, and the lower parts are connected by a pair of left and right square pipe-shaped mounting frames 52 that are spaced a predetermined distance apart in the left-right direction and extend in the front-rear direction.

[0031] The front portion of the mounting frame 51 extends forward of the battery 50, and the rear portion extends rearward of the battery 50. The mounting frame 52 extends from the front end to the rear end of the battery 50.

[0032] As shown in Figures 3 and 9, the front part of the mounting frame 51 is removably fixed to the horizontal frame 20A of the support frame 20 by fastening members such as bolts, and the rear part is removably fixed to the horizontal frame 21A of the support frame 21 by fastening members such as bolts.

[0033] The left mounting frame 52 is placed on the left front-rear frame 22L, and the right mounting frame 52 is placed on the right front-rear frame 22R.

[0034] Openings 51A are formed in the front and rear of the mounting frame 51 to allow insertion of hanging hooks when replacing the battery 50. This allows the battery 50 to be easily attached to and detached from the support frames 20 and 21, making it easy to replace the battery 50.

[0035] 10 and 11 , a first inverter device 35 for driving the first electric motor 30 is provided at a predetermined distance in the front-rear direction behind the first electric motor 30, and a second inverter device 45 for driving the second electric motor 40 is provided at a predetermined distance in the front-rear direction behind the second electric motor 40. The first inverter device 35 and the second inverter device 45 are also provided at a predetermined distance in the front-rear direction in front of the battery 50. This facilitates the routing of the first electric motor 30, the second electric motor 40, and the first inverter device 35 and the second inverter device 45. Furthermore, air blown by the fan 61 passes through the gaps between the first electric motor 30, the second electric motor 40, and the first inverter device 35 and the second inverter device 45, thereby efficiently cooling the first electric motor 30, the second electric motor 40, and the first inverter device 35 and the second inverter device 45.

[0036] As shown in FIG. 12 , the output rotation of the output shaft 30A of the first electric motor 30 is reduced in speed by the first reducer 31 and then output from the first output shaft 31A and output shaft 31B of the first reducer 31.

[0037] The output rotation of the first output shaft 31A is transmitted to a work PTO 33 via a work clutch 32 to drive the work device 4. In addition, the output rotation of the output shaft 31B is transmitted to a hydraulic pump 34 that pressurizes and feeds oil to be supplied to the lifting component 19 and the like.

[0038] The output rotation of the output shaft 30A of the first electric motor 30 is transmitted to a blower PTO 37 via a blower clutch 36 to drive the blower 17.

[0039] The output rotation of the output shaft 40A of the second electric motor 40 is reduced in speed by the second reducer 41 and then output from the second output shaft 41A of the first reducer 31.

[0040] The output rotation of the second output shaft 41A is transmitted to a differential gear 42 for the front wheels to drive the front wheels 2, and is also transmitted to a differential gear 44 for the rear wheels via a 4WD clutch 43, and the output rotation of the differential gear 44 is transmitted to a drive shaft 46 to drive the rear wheels 3.

[0041] As shown in FIGS. 13 and 14, a power receiving port 70 for receiving power from a household power source is provided on the upper rear side of the radiator 60.

[0042] An electrical equipment unit 71 is provided below the battery 50. The electrical equipment unit 71 includes a charger 71A that converts the power supplied to the power receiving port 70 from AC to DC and supplies the power to the battery 50, and a converter 71B that reduces the DC voltage supplied via a power distribution unit 73 or the like to the rated voltage of the auxiliary battery 65. The electrical equipment unit 71 is detachably fixed to the lower sides of the left front and rear frames 22L and right front and rear frames 22R.

[0043] A monitoring unit 72 incorporating a monitoring device for monitoring the temperature and voltage of the battery 50 is provided in front of the battery 50. The monitoring unit 72 is detachably fixed to the upper sides of the left front and rear frames 24L and right front and rear frames 24R.

[0044] In a side view, it is preferable that the upper wall of the monitoring unit 72 is positioned lower than the mounting frame 51. This prevents the monitoring unit 72 from protruding above the mounting frame 51 and allows the vertical height of the motor chamber 8 to be made low, so that the center of gravity of the grass collection container 7 located above the motor chamber 8 can be set at a low position, allowing the work vehicle to travel stably.

[0045] A power distribution unit 73 having a built-in terminal block that distributes the power supplied from the monitoring unit 72 to the first inverter device 35, the second inverter device 45, the converter 71B of the electrical unit 71, etc. is provided below the monitoring unit 72. The power distribution unit 73 is detachably fixed to the lower sides of the left front-rear frame 24L and the right front-rear frame 24R.

[0046] A pressure valve 60A is provided at the top of the radiator 60, a cooling pump 63 that pressurizes the water cooled by the radiator 60 is provided at the lower rear side of the radiator 60, and a reserve tank 64 that stores the reserve water circulating through the radiator 60 is provided at the rear side of the radiator 60.

[0047] 15 , water pumped from the cooling pump 63 flows into a flow path 66A that circulates through the cooling member attached to the first electric motor 30 and the cooling member attached to the first inverter device 35 and returns to the radiator 60, and a flow path 66B that circulates through the cooling member attached to the electrical unit 71, the cooling member attached to the second electric motor 40, and the cooling member attached to the second inverter device 45 and returns to the radiator 60. This allows for efficient cooling of the first electric motor 30, which generates more heat and rotates with a higher torque to drive the working device 4 than the second electric motor 40.

[0048] The cooling element attached to the electrical unit 71 is located above the cooling pump 63. In a side view, the liquid levels of the cooling elements attached to the electrical unit 71, the first inverter device 35, the second inverter device 45, and the first electric motor 30 and the second electric motor 40 are located in this order from bottom to top, with the liquid levels of the cooling elements attached to the first electric motor 30 and the second electric motor 40 being located at the highest positions. In addition, in a side view, the pressure valve 60A of the radiator 60 is located at a position higher than the liquid levels of the cooling elements attached to the first electric motor 30 and the second electric motor 40. As a result, air from the cooling pump 63 is exhausted to the outside via the cooling elements attached to the electrical unit 71 and the like, thereby suppressing air entrapment in the cooling pump 63 and preventing breakdown of the cooling pump 63. The liquid surface in this specification refers to the top surface of the water that flows into the cooling member attached to the electrical unit 71 when the work vehicle is stopped in a horizontal position in a side view.

Claims

1. A work vehicle provided with running wheels (2, 3) and a working device (4) for cutting grass, comprising: a first electric motor (30) for driving the working device (4), and a second electric motor (40) for driving the running wheels (2, 3); a battery (50) for storing electricity to be supplied to the first electric motor (30) and the second electric motor (40); a monitoring unit (72) for monitoring the charging state of the battery (50) is provided above the first electric motor (30) and the second electric motor (40); a grass collection container (7) for collecting cut grass is provided above the first electric motor (30) and the second electric motor (40) and the monitoring unit (72); and the monitoring unit (72) is provided below the battery (50) and in front of the battery (50).

2. A work vehicle as described in claim 1, wherein the battery (50) is formed from a plurality of battery modules (50A) and a mounting frame (51) that connects the upper parts of the plurality of battery modules (50A), and the upper wall of the monitoring unit (72) is located lower than the mounting frame (51).

3. A work vehicle as described in claim 2, further comprising a power receiving port (70) for connecting an external power source, and a charger (71A) for converting the power supplied to the power receiving port (70) from AC to DC and supplying the converted power to the battery (50) when viewed from the side and provided below the battery (50).

4. A work vehicle as described in claim 3, further comprising: a first inverter device (35) for driving the first electric motor (30); a second inverter device (45) for driving the second electric motor (40); and a power distribution unit (73) for distributing power supplied from the battery (50) to the first inverter device (35) and the second inverter device (45) between the first electric motor (30), the second electric motor (40) and the monitoring unit (72).

5. A work vehicle as set forth in claim 4, further comprising: a radiator (60) for cooling water circulating through an electrical unit (71) provided on the left and right outer sides of an electric compartment (8) housing the first electric motor (30) and the second electric motor (40); and a cooling pump (63) for pumping water discharged from the radiator (60) provided below the electrical unit (71) in a side view.

6. A work vehicle as described in claim 1, wherein, in a plan view, the longitudinal direction of the first electric motor (30) is arranged along the fore-and-aft direction on one left or right side of the left-right center of the body frame (1), and the longitudinal direction of the second electric motor (40) is arranged along the fore-and-aft direction on the other left or right side.

7. A work vehicle according to claim 6, wherein the vertical center of said first electric motor (30) and the vertical center of said second electric motor (40) are located at the same height when viewed from behind.

8. A work vehicle according to claim 6 or 7, wherein the first electric motor (30) is an electric motor capable of outputting a higher torque than the second electric motor (40).

9. A work vehicle as claimed in claim 6 or 7, further comprising a fan (61) disposed between the radiator (60) and the first electric motor (30) for blowing outside air into the motor chamber (8) housing the first electric motor (30) and the second electric motor (40).

10. A work vehicle as set forth in claim 6 or 7, wherein the battery (50) is provided so as to overlap the upper side of the drive shaft (46) extending in the left-right direction of the rear wheels (3) in a plan view.

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