Work vehicle

Abstract

Provided is a work vehicle comprising wheels (2, 3), a work device (4), a first electric motor (30) for driving the work device (4), and a second electric motor (40) for driving the wheels (2, 3), wherein the first electric motor (30) is used to drive a hydraulic pump (51) for feeding oil to hydraulic equipment mounted in the vehicle. Thus, it is possible to drive the hydraulic pump (51) using an electric motor for work without separately providing an electric motor for driving the hydraulic pump (51).

Description

Work vehicles

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

[0002] Conventionally, there is known a work vehicle that includes a work motor that drives a work device for cutting grass that is mounted on the front side of the vehicle frame, and a propulsion motor that drives the front wheels, etc. (Patent Document 1)

[0003] Japanese Patent Application Laid-Open No. 2023-27497

[0004] However, the work vehicle of Patent Document 1 is not equipped with a hydraulic pump, and therefore cannot operate hydraulic equipment such as a hydraulic clutch. Furthermore, in the case of an electric vehicle, the rotation speed of the electric motor fluctuates depending on changes in the driving condition, so there is a problem in stably driving the hydraulic pump compared to an internal combustion engine that rotates at idle.

[0005] SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a work vehicle that is driven by an electric motor and that is capable of stably driving a hydraulic pump.

[0006] The present invention solves the above-mentioned problems as follows: That is, the invention described in claim 1 is characterized in that, in a work vehicle having wheels (2, 3) and a working device (4), a first electric motor (30) that drives the working device (4), and a second electric motor (40) that drives the wheels (2, 3), a hydraulic pump (51) that feeds oil to hydraulic equipment mounted on the vehicle is driven by the first electric motor (30).

[0007] According to the invention described in claim 1, even when the second electric motor (40) is stopped and the work vehicle is stopped, the hydraulic pump (51) can be driven stably, so that hydraulic equipment connected to the hydraulic pump (51) can be operated.

[0008] 1 is a perspective view of a work vehicle as viewed from the front left side; FIG. 2 is a perspective view of the front part of the electric chamber as viewed from the rear left side; FIG. 3 is a perspective view of the rear part of the electric chamber as viewed from the rear left side; FIG. 4 is a perspective view of the electric motor and gear case as viewed from the front left side; FIG. 5 is a perspective view of the electric motor and gear case as viewed from the rear left side; FIG. 6 is a rear view of the electric motor and gear case; FIG. 7 is a cross-sectional view with the left part of the gear case cut away; FIG. 8 is an explanatory diagram of an oil seal into which the input shaft of the gear case is fitted; FIG. 9 is a transmission diagram of the output rotation of the electric motor.

[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 mounted at the front of the machine frame 1, and a control section 5 on which an operator rides is mounted behind the working device 4. A safety frame (ROPS) 6 for protecting the operator is mounted behind the control section 5, and a grass collection container 7 for storing cut grass is mounted behind the safety frame 6, and an electric motor room 8 is mounted below the grass collection container 7, in which a first electric motor 30 for driving the working device 4, a battery 60, etc. are mounted.

[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 first electric motor 30 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 slowing down the rotation speed of the front wheels 2 is provided on the left side of the steering column 10 on the floor, and an accelerator pedal 12 for increasing or decreasing the output rotation speed of the second electric motor 40 for driving the front wheels 2 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 speed change lever 14 for operating an inverter device 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 motor chamber 8A of the motor chamber 8 is provided with a first motor 30 and a second motor 40, and the rear motor chamber 8B is provided with a battery 60 that stores electricity to be supplied to the first 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 makes it possible to reduce 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 60 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 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 and 5 , the first electric motor 30 and the second electric motor 40 are connected to a gear case 50 provided in front of the first electric motor 30 and the second electric motor 40. The output rotation of the first electric motor 30 is increased or decreased in the gear case 50 and then transmitted to a first output shaft 31 to which the work device 4 and the like are connected, an output shaft 32 to which the blower 17 and the like are connected, and a second output shaft 33 to which the hydraulic pump 51 and the like are connected. In addition, the output rotation of the second electric motor 40 is increased or decreased in the gear case 50 and then transmitted to an output shaft 41 to which the front wheels 2 and the like are connected, and an output shaft 42 to which an auxiliary work device and the like are connected. Note that in this technical field, the output shaft is often referred to as a PTO.

[0024] The first output shaft 31 extends forward from the left central portion of the gear case 50 in the front-to-rear direction, and the front portion of the first output shaft 31 is connected to the working device 4. The output shaft 32 extends forward from the front portion of the gear case 50, and the front portion of the output shaft 32 is connected to the blower 17. The second output shaft 33 extends rearward from the rear portion of the gear case 50, and the rear portion of the second output shaft 33 is connected to a hydraulic pump 51. In addition, a valve 52 is provided on the upper portion of the gear case 50.

[0025] The output shaft 41 and the output shaft 42 extend in the front-rear direction on the right side of the gear case 50. The output rotation of the output shaft 41 is transmitted to the drive shaft 43 via a differential gear 54 provided inside the gear case 50. An insertion hole 50A extending in the left-right direction, through which the drive shaft 43 is inserted, is provided in the middle of the gear case 50 in the front-rear direction. The output shaft 42 extends rearward from the rear of the gear case 50.

[0026] The length of the first electric motor 30 in the front-rear direction is longer than the length of the second electric motor 40 in the front-rear direction. This allows the working device 4, which is constantly driven and subjected to a large load, to be driven smoothly.

[0027] As shown in Figure 6, the hydraulic pump 51 is provided below the first electric motor 30 and the second electric motor 40. This prevents air from entering the hydraulic pump 51, thereby suppressing air entrapment. Furthermore, a flexible pipe 53A connecting the hydraulic pump 51 and the valve 52 is routed between the first electric motor 30 and the second electric motor 40. This allows the space formed between the first electric motor 30 and the second electric motor 40 to be used effectively.

[0028] 7, oil sent to the valve 52 is sent via the valve 52 to a clutch 55 provided upstream of the power transmission path of the first output shaft 31 in the gear case 50, and to a clutch 56 provided upstream of the power transmission path of the output shaft 32. This allows the valve 52 to be operated to engage and disengage the clutch 55 and the clutch 56.

[0029] The oil sent from the clutch 55 or the clutch 56 to the valve 52 is returned to the gear case 50 from a circulation port 50B formed in the upper part of the gear case 50 via a flexible pipe 53B. This makes it possible to maintain a predetermined amount of oil in the gear case 50.

[0030] 8, an oil seal 50C is provided on the outer periphery of the input shaft 57A of the gear case 50 connected to the first electric motor 30. This prevents the oil filled in the gear case 50 from flowing along the outer periphery of the input shaft 57A and being discharged to the outside.

[0031] As shown in FIG. 9, the output rotation of the first electric motor 30 is transmitted to the input shaft 57A of the gear case 50, and the output rotation of the input shaft 57A is accelerated or decelerated before being transmitted to the rotary shaft 58A.

[0032] The output rotation of the rotary shaft 58A is accelerated or decelerated and then transmitted to the second output shaft 33, and the output rotation of the second output shaft 33 is transmitted to the hydraulic pump 51. In this way, the first electric motor 30 is driven, and the hydraulic pump 51 is driven.

[0033] The output rotation of the rotary shaft 58A is accelerated or decelerated before being transmitted to the rotary shaft 58B, and the output rotation of the rotary shaft 58B is transmitted to the first output shaft 31 via the clutch 55. The output rotation of the first output shaft 31 is transmitted to the working device 4. This drives the first electric motor 30, thereby driving the working device 4.

[0034] The output rotation of the rotary shaft 58A is accelerated or decelerated before being transmitted to the rotary shaft 58C, and the output rotation of the rotary shaft 58C is transmitted to the output shaft 32 via the clutch 56. The output rotation of the output shaft 32 is transmitted to the blower 17. This drives the first electric motor 30, thereby driving the blower 17.

[0035] The output rotation of the second electric motor 40 is transmitted to the input shaft 57B of the gear case 50, and the output rotation of the input shaft 57B is transmitted to the output shaft 41 and the output shaft 42 after being accelerated or decelerated.

[0036] The output rotation of the output shaft 41 is transmitted to the drive shaft 43 for the front wheels via the differential gear 54, and the output rotation of the drive shaft 43 is transmitted to the front wheels 2. This drives the second electric motor 40 to rotate the front wheels 2. The output rotation of the output shaft 42 can also be transmitted to the rear wheels 3 via a clutch, an auxiliary implement, a differential gear, etc.

Claims

1. A work vehicle equipped with wheels (2, 3) and a working device (4), a first electric motor (30) that drives the working device (4), and a second electric motor (40) that drives the wheels (2, 3), characterized in that a hydraulic pump (51) that supplies oil to hydraulic equipment mounted on the vehicle is driven by the first electric motor (30).

2. A work vehicle as described in claim 1, wherein a second output shaft (33) is provided upstream of a first output shaft (31) that transmits power to the working device (4) in the transmission path, the hydraulic pump (51) is connected to the second output shaft (33), and a clutch (55) that connects and disconnects the transmission path is provided between the transmission path of the first output shaft (31) and the second output shaft (33).

3. A work vehicle according to claim 2, wherein the first output shaft (31) extends forward from the gear case (50), and the second output shaft (33) extends rearward from the gear case (50).

4. A work vehicle according to claim 3, wherein the hydraulic pump (51) is disposed below the first electric motor (30) and the second electric motor (40).

5. A work vehicle as described in claim 4, wherein a valve (52) for controlling the clutch (55) is provided on the upper part of the gear case (50), the hydraulic pump (51) and the valve (52) are connected by a pipe (53A), and the pipe (53A) is laid between the first electric motor (30) and the second electric motor (40).

6. A work vehicle as described in claim 5, wherein a circulation port (50B) is formed in the upper part of the gear case (50), the valve (52) and the circulation port (50B) are connected by a pipe (53B), and oil sent from the clutch (55) to the valve (52) is sent to the gear case (50) via the pipe (53B).

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