JP2025068013A - Work vehicle - Google Patents

Abstract

To provide a work vehicle capable of turning appropriately by driving rear wheels, etc. with high energy efficiency.SOLUTION: A work vehicle is provided with: a right and left pair of front wheels 2 in the front part of a travelling vehicle body 1; a right and left pair of rear wheels 3 in the rear part of the travelling vehicle body 1; a bonnet part 5 formed with a prescribed space on the front side on the top face of the travelling vehicle body 1; and an operation part 6 that an operator gets on, on the rear side of the bonnet part 5. An electric motor 30 is provided for driving the rear wheels 3. A battery 50 for storing electric power to be supplied to the electric motor 30 is provided in the bonnet part 5. A travelling vehicle body main body 10 for supporting the front wheels 2 includes a left front-back frame 10L and a right front-back frame 10R extending in the front-back direction. The battery 50 is connected to the travelling vehicle body main body 10 through a left support member 12L erected in the front part of the left front--back frame 10L and a right support member 12R erected in the front part of the right front-back frame 10R.SELECTED DRAWING: Figure 8

Description

The present invention relates to a work vehicle .

Conventionally, a known working vehicle has an engine mounted in a bonnet section, and the output rotation of the engine is transmitted to rear wheels or a working machine such as a mower deck supported on the bottom of the working vehicle so as to be freely raised and lowered to drive the machine (see Patent Document 1).
Also, a known working vehicle has a battery mounted at the rear of the vehicle, and power from the battery is supplied to an electric motor, and the output rotation of the electric motor is transmitted to the rear wheels or a working machine such as a mower deck supported at the front of the vehicle so that it can be raised and lowered to drive the vehicle (Patent Document 2).

JP 2003-158907 A JP 2020-156340 A

However, the solution described in Patent Document 1 had the risk of low energy efficiency due to the complex configuration of the transmission equipment that transmits the engine's output rotation to the rear wheels and the work equipment, and the large number of parts.

Furthermore, with the solution disclosed in Patent Document 2, the weight balance is biased towards the rear, which may make it difficult to turn when steering the front wheels .

SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide a work vehicle that can drive the rear wheels etc. with high energy efficiency and can turn smoothly .

The present invention, which solves the above problems, is as follows:

That is, the invention described in claim 1 is a work vehicle having a pair of left and right front wheels (2) at the front of a running body (1), a pair of left and right rear wheels (3) at the rear of the running body (1), a bonnet section (5) with a predetermined space formed on the front side of the upper surface of the running body (1), and a control section (6) on which a driver sits at the rear of the bonnet section (5), characterized in that an electric motor (30) is provided to drive the rear wheels (3), and a battery (50) is provided in the bonnet section (5) for storing electricity to be supplied to the electric motor (30) , the running body main body (10) has left front and rear frames (10L) and right front and rear frames (10R) extending in the fore-and-aft direction, and the battery (50) is connected to the running body main body (10) via a left support member (12L) erected at the front of the left front and rear frame (10L) and a right support member (12R) erected at the front of the right front and rear frame (10R) .

According to a second aspect of the present invention, a battery bracket (52) having a left front-rear frame (52L) and a right front-rear frame (52R) extending in the front-rear direction is fixed to the battery (50), a left support member (12L) provided on the left part of the traveling body (1) and the left front-rear frame (52L) are connected via a left vibration-isolating member (53L), and a right support member (12R) provided on the right part of the traveling body (1) and the right front-rear frame (52R) are connected via a right vibration-isolating member (53R), and When viewed from the front, the connecting portion of the left support member (12L) and the connecting portion of the left front and rear frame (52L) is formed with an upward slope to the left, and the connecting portion of the right support member (12R) and the right front and rear frame (52R) is formed with an upward slope to the right.This is a work vehicle as described in claim 1, in which, when viewed from the front, the connecting portion of the left support member (12L) and the left front and rear frame (52L) is formed with an upward slope to the left, and the connecting portion of the right support member (12R) and the right front and rear frame (52R) is formed with an upward slope to the right.

The invention described in claim 3 is the work vehicle described in claim 2, in which, in a front view, the connecting portion of the left support member (12L) and the connecting portion of the left front and rear frame (52L) are formed perpendicular to a left imaginary line (55L) connecting the center of the left vibration-proof member (53L) and the center of the left front wheel (2L) of the front wheels (2), and the connecting portion of the right support member (12R) and the connecting portion of the right front and rear frame (52R) are formed perpendicular to a right imaginary line (55R) passing through the center of the right vibration-proof member (53R) and the center of the right front wheel (2R) of the front wheels (2).

In the invention described in claim 4, when viewed from the side, the traveling vehicle body (1) is formed of a traveling vehicle body main body (10) extending in the front-rear direction and a steering post (11) extending in the up-down direction and supporting a steering shaft (63) of the operation unit (6),
A buffer member (15) is provided at a predetermined interval in the left-right direction on the lower part of the front surface of the steering post (11),
The work vehicle according to any one of claims 1 to 3, wherein a tip end of the buffer member (15) is pressed against a rear surface of the battery (50).

According to the invention described in claim 1, the vehicle can drive the rear wheels (3) with high energy efficiency, and by connecting the battery (50) via the left and right support members (12L, 12R) erected at the front of the left and right front and rear frames (10L, 10R) of the traveling vehicle body (10) that support the front wheels (2), the weight balance is shifted forward, allowing for good turning. In addition, the space formed in the bonnet (5) can be effectively utilized to prevent rainwater from getting on the battery (50).

According to the invention described in claim 2, in addition to the effect of the invention described in claim 1, it is possible to further prevent the battery (50) from being damaged by large lateral vibrations that occur in the traveling vehicle body (1) during traveling.

According to the invention described in claim 3, in addition to the effect of the invention described in claim 2, large vibrations caused by unevenness of the driving surface can be suppressed via the left front wheel (2L) and the right front wheel (2R), and damage to the battery 50 can be further suppressed.

According to the invention described in claim 4, in addition to the effects of the invention described in any one of claims 1 to 3, it is possible to prevent the battery (50) from moving backward when the work vehicle starts, thereby suppressing the battery (50) from colliding with surrounding components and being damaged.

FIG. FIG. 2 is a left side view of the work vehicle with the bonnet cover in an open position. 1 is a perspective view of a main portion of a work vehicle with a part cut away. FIG. FIG. 2 is a plan view of the rear wheels and essential parts of the working machine. FIG. 4 is a left side view of the rear wheel and essential parts of the work machine. FIG. 2 is a left side view of the electric motor for the rear wheels and the electric motor for the work machine. FIG. FIG. FIG. 2 is a perspective view of a battery and a battery bracket. FIG. FIG. 2 is a front view of the front wheel, the battery, and the battery bracket. FIG. 2 is a plan view of a main portion of the work vehicle with a part cut away. FIG. FIG. 2 is a perspective view of a housing of the inverter device. FIG. 2 is a perspective view of a housing of the battery monitoring device. FIG. 2 is a left side view of the brake pedal, the electric cylinder, and the drum brake. FIG. 2 is a plan view of the brake pedal, the electric cylinder, and the drum brake.

As shown in FIG. 1, a work vehicle such as a riding lawnmower has a running body 1, a pair of left and right front wheels 2 at the front of the running body 1, a pair of left and right rear wheels 3 at the rear of the running body 1, and a working machine 4 for cutting grass and the like is provided between the front wheels 2 and the rear wheels 3 on the underside of the running body 1. In addition, a bonnet section 5 is provided at the front of the upper side of the running body 1, a control section 6 on which a driver sits is provided behind the bonnet section 5, and a grass collection container 7 for storing grass and the like cut by the control section 4 is provided behind the control section 6.

As shown in Figures 2 and 3, the bonnet section 5 is provided with a battery 50 that stores electricity to be supplied to the electric motor 30 that drives the rear wheels 3, and the battery 50 is covered with a bonnet cover 51. The bonnet cover 51 is supported by a support shaft (not shown) that extends in the left-right direction and is provided at the front of the traveling body 1. This makes it possible to effectively utilize the space formed in the bonnet section 5 and also to suppress differences in the weight balance in the fore-and-aft direction of the work vehicle.

Electrical components 61 are provided below the cockpit 60 of the control section 6. This allows the space below the cockpit 60 to be used effectively.

4 to 7, an electric motor 30, such as a synchronous motor or an induction motor, which is operated with a three-phase AC voltage waveform to drive the rear wheels 3, is provided below the electrical components 61. An output shaft 30A formed to extend in the left-right direction of the electric motor 30 is connected to an upper portion of a gear box 31 which reduces the speed of the output rotation transmitted from the output shaft 30A to increase the output torque or reverse the direction of rotation. The electric motor 30 is provided at a position offset to the left of the center in the left-right direction .
The output rotation accelerated or decelerated by the gear box 31 is transmitted to a drive shaft 33 extending in the left-right direction via a differential gear 32 formed by a differential gear or the like and provided at the bottom of the gear box 31. The output rotation transmitted to the drive shaft 33 is transmitted to the rear wheels 3 supported at both ends of the drive shaft 33 .
An electric motor 40, such as a synchronous motor or an induction motor, is provided below the electric motor 30 and is operated with a three-phase AC voltage waveform to drive the working machine 4. An output shaft 40A extending in the front-rear direction of the electric motor 40 is connected to the rear of a universal joint 41 extending in the front-rear direction. The output shaft 40A is provided above the drive shaft 33 and perpendicular to the drive shaft 33. This allows the space formed below the electric motor 30 to be effectively utilized. In addition, the transmission path between the electric motor 40 and the working machine 4 can be shortened, so that the output rotation of the electric motor 40 can be efficiently transmitted to the working machine 4. The electric motor 40 is provided at a position offset to the left of the center in the left-right direction.

The front part of the universal joint 41 is connected to a gear box 42 that reduces the speed of the output rotation transmitted from the universal joint 41 to increase the output torque. The output rotation transmitted to the gear box 42 is transmitted to a left cutting blade (not shown) provided in the left discharge passage 45L of the work machine 4 via an output shaft formed by extending in the vertical direction of the gear box 42.

A connecting member 43 extending in the left-right direction is connected to the left part of the gearbox 42, and the right part of the connecting member 43 is connected to the gearbox 44. The output rotation transmitted to the gearbox 44 is transmitted to a right cutting blade (not shown) provided in the right discharge passage 45R of the work machine 4 via an output shaft formed by extending in the vertical direction of the gearbox 44. The output rotation speeds of the output shafts of the gearbox 42 and the gearbox 44 are the same, but the rotation directions are opposite; that is, in a plan view, the output shaft of the gearbox 42 rotates clockwise, and the output shaft of the gearbox 44 rotates counterclockwise.

The discharge outlets of the left discharge passage 45L and the right discharge passage 45R are connected to the inlet of the chute 46, which transports the cut grass and other materials to the grass collection container 7. The discharge outlet of the chute 46 is connected to the inlet of the grass collection container 7.

In plan view, the front of the chute 46 is provided to the right of the universal joint 41, the rear of the chute 46 is provided to the right of the gear box 31, and in rear view, the chute 46 and grass collection container 7 are provided between the gear box 31 and the right rear wheel 3. This allows a large chute 46 to be provided in the space formed to the right of the universal joint 41 and the gear box 31, and grass and other materials cut by the work machine 4 can be efficiently transported to the grass collection container 7.

When viewed from the side, the upper wall of the chute 46 is formed with an upward incline toward the rear, and the rear of the chute 46 extends downward below the electrical components 61. This makes the rear of the chute 46 larger, preventing grass and other debris from clogging the inside of the chute 46.

As shown in Figures 8 and 9, the vehicle body 1 is formed of a vehicle body main body 10 that supports the front wheels 2 and rear wheels 3, and a steering post 11 that supports the steering shaft 63.

The vehicle body 10 is formed with a left front-rear frame 10L and a right front-rear frame 10R that extend in the fore-aft direction, and the lower part of the steering post 11 is formed with a left connecting part 11L and a right connecting part 11R that extend forward.

The left connecting part 11L is fixed to the left front and rear frame 10L by a fastening means such as a bolt, and the right connecting part 11R is fixed to the right front and rear frame 10R by a fastening means such as a bolt, and they are integrated to form the traveling vehicle body 1.

A left support member 12L is provided at the front of the left front-rear frame 10L, and the connecting portion of the left support member 12L is formed with an upward incline to the left. A right support member 12R is provided at the front of the right front-rear frame 10R, and the connecting portion of the right support member 12R is formed with an upward incline to the right. The left support member 12L and the right support member 12R are made of channel steel.

A left support member 13L is provided in front of the left connecting part 11L, and the connecting part of the left support member 13L is formed with an upward incline to the left. A right support member 13R is provided in front of the right connecting part 11R, and the connecting part of the right support member 12R is formed with an upward incline to the right. The left support member 13L and the right support member 13R are made of channel steel.

The lower part of the steering post 11 is formed with protrusions 14 that protrude forward at a predetermined distance in the left-right direction, and a buffer member 15 made of a rubber material or the like is provided at the tip of the protrusions 14.

As shown in FIG. 10, the lower part of the battery 50 provided inside the bonnet section 5 is fitted inside the inner circumference of the battery bracket 52. The battery 50 is formed by connecting multiple high-energy-density lithium-ion batteries in series and parallel. This allows the space formed in the bonnet section 5 to be used effectively. In addition, because the lithium-ion battery has a high energy density, the work vehicle can travel long distances on a single full charge.

As shown in FIG. 11, the battery bracket 52 is formed of a left front-rear frame 52L and a right front-rear frame 52R extending in the front-rear direction, a front left-right frame 52A connecting the front parts of the left front-rear frame 52L and the right front-rear frame 52R, and a rear left-right frame 52B connecting the rear parts of the left front-rear frame 52L and the right front-rear frame 52R. The left front-rear frame 52L and the right front-rear frame 52R are formed from angle steel, and the front left-right frame 52A and the rear left-right frame 52B are formed from channel steel.

The connecting portion of the left front-rear frame 52L is inclined upward to the left, and the connecting portion of the right front-rear frame 52R is inclined upward to the left. In rear view, the connecting portion of the left support member 13L, the connecting portion of the left support member 12L, and the connecting portion of the left front-rear frame 52L are inclined upward to the left at the same inclination angle, and the connecting portion of the right support member 12R, the connecting portion of the right support member 12R, and the connecting portion of the right front-rear frame 52R are inclined upward to the right at the same inclination angle.

A circular left vibration isolating member 53L is provided at a predetermined distance in the front-to-rear direction on the underside of the connecting part of the left front-to-rear frame 52L, and a circular right vibration isolating member 53R is provided at a predetermined distance in the front-to-rear direction on the underside of the connecting part of the right front-to-rear frame 52R.

The left front and rear frame 52L is connected to the left support member 12L of the left front and rear frame 10L and the left support member 13L of the left connecting part 11L via the left vibration isolator 53L, and the right front and rear frame 52R is connected to the right support member 12R of the right front and rear frame 10R and the right support member 13R of the right connecting part 11R via the right vibration isolator 53R. This makes it possible to prevent the vibration of the traveling vehicle body 10 that occurs when the work vehicle is traveling from being transmitted to the battery 50, thereby preventing damage to the battery 50.

As shown in FIG. 12, the connecting portion of the left front and rear frame 52L is provided perpendicular to the left imaginary line 55L that connects the center of the left vibration isolator 53L and the center of the left front wheel 2L on the left side. The connecting portion of the right front and rear frame 52R is provided perpendicular to the right imaginary line 55R that connects the center of the right vibration isolator 53R and the center of the right front wheel 2R on the right side. This makes it possible to suppress large vibrations caused by unevenness of the running surface via the front wheels 2 and rear wheels 3, and to prevent damage to the battery 50. Reference numeral 57 denotes a front wheel support frame that supports the left and right front wheels 2, and reference numeral 56 denotes a connecting portion between the front wheel support frame and the running vehicle body 10, and indicates the swing axis of the front wheel support frame.

The tip of the buffer member 15 of the steering post 11 is pressed against the rear surface of the left and right rear frames 52B of the battery bracket 52. This prevents the battery 50 from moving backward when the work vehicle starts, and prevents damage to the battery 50.

As shown in Figures 2 and 3, a steering wheel 62 is provided in front of the cockpit 60 of the control section 6, and the steering wheel 62 is supported on the upper part of a steering shaft 63 that extends in the vertical direction.

A cleaner lever 65 is provided on the left fender 64L on the left side of the operator's seat 60 to transport grass clippings remaining inside the chute 46 to the grass collection container 7 at the rear, while an operating lever 66 is provided on the right fender 64R of the operator's seat 60 to raise and lower the work machine 4. A brake pedal 68 is provided on the left front part of the floor 67 on which the operator places his or her feet when operating the vehicle, and a forward accelerator pedal 75 and a reverse accelerator pedal 76 are provided side by side on the right front part.

As shown in Figures 13 and 14, the electrical components 61 installed under the cockpit 60 are composed of an inverter device 80 that converts the DC voltage supplied from the battery 50 to AC voltage and generates a three-phase AC voltage waveform to operate the electric motor 30, a battery monitoring device 81 that monitors the temperature, charging state, voltage protection, and short-circuit state of each cell of the battery 50, an auxiliary battery 82 such as a lead storage battery that stores electricity to be supplied to a meter panel (not shown) that displays the driving speed, etc., installed in front of the cockpit 60, and a converter device 83 that converts the DC voltage supplied from the battery 50 to a DC voltage that is supplied to a sensor that detects the operating position of the cleaner lever 65, etc.

The inverter device 80 is composed of an inverter device 84 that operates the electric motor 30 and an inverter device 85 that operates the electric motor 40. In addition, when regenerative braking is activated, that is, when the forward accelerator pedal 75 or the reverse accelerator pedal 76 is released and the output shaft 30A rotates due to the inertial force of the traveling vehicle body 1 and the electric motor 30 operates as a generator, the inverter device 84 also functions as a charging device that charges the battery 50 with the power supplied from the electric motor 30 to the inverter device 80.

In a plan view, an inverter device 80 is provided at the front below the driver's seat 60, and a battery monitoring device 81 is provided behind the inverter device 80. An auxiliary battery 82 is provided to the left of the inverter device 80, and a converter device 83 is provided to the left of the battery monitoring device 81 and behind the auxiliary battery 82. This allows the space formed below the driver's seat 60 to be effectively utilized. Also, by providing the heavy battery monitoring device 81 at the rear, the difference in weight applied to the front and rear of the traveling vehicle body 10 can be reduced, improving traveling stability.

As shown in FIG. 15, circular grommets 86 are provided on the inner surface of the left and right walls of the housing 80A of the inverter device 80 at a predetermined interval in the front-rear direction. The housing 80A is also connected to the left and right frames 16 extending in the left-right direction provided at the rear of the traveling vehicle body 10 via the grommets 86. This makes it possible to suppress the transmission of vibrations of the traveling vehicle body 10 generated when the work vehicle is traveling to the inverter device 80, thereby preventing damage to the inverter device 80. In addition, electric wires connecting the inverter device 80 and the electric motor 30 can be inserted into the hollow portion formed in the grommet 86 to easily arrange the electric wires.

As shown in FIG. 16, round grommets 87 are provided at a predetermined interval in the front-rear and left-right directions on the bottom wall of the housing 81A of the battery monitoring device 81. The housing 81A is also connected to a support frame 18 connected to the left and right frames 17 provided on the rear side of the left and right frames 16 via the grommets 87. This makes it possible to suppress the vibrations of the traveling vehicle body 10 that occur when the work vehicle is traveling from being transmitted to the battery monitoring device 81, thereby preventing damage to the battery monitoring device 81. In addition, the electric wires connecting the battery monitoring device 81 and the battery 50 can be inserted into the hollow portion formed in the grommet 87 to easily arrange the electric wires.

As shown in Figures 17 and 18, the electric cylinder 70 and the brake 71 provided on the rear wheel 3 are connected by a rod 72 extending in the front-rear direction. The rod tip of the electric cylinder 70 and the rod 72 are connected by a connecting member 73.

When a brake switch (not shown) provided on the steering unit 6 is turned ON, the rod of the electric cylinder 70 contracts, moving the rod 72 forward and activating the brake 71 to stop the drive of the rear wheels 3. This allows the brake switch to be turned ON in an emergency to drive the electric cylinder 70 and bring the work vehicle to an emergency stop.

When the brake switch is turned OFF, the rod of the electric cylinder 70 extends, moving the rod 72 rearward to stop the operation of the brake 71 and drive the rear wheel 3.

The front part of the rod 72 is connected to the rear part of the brake pedal 68. When the brake pedal 68 is depressed, the brake pedal 68 rotates counterclockwise around a support shaft 68A extending in the left-right direction, and the rod 72 can be moved forward. This allows the brake pedal 68 to be depressed to activate the brake 71 even if the electric cylinder 70 malfunctions, thereby improving safety.

When the brake pedal 68 is released, a spring or other traction means 69 is provided at the bottom of the brake pedal 68, causing the brake pedal 68 to rotate clockwise around the pivot 68A, moving the rod 72 rearward and deactivating the brake 71, allowing the rear wheel 3 to be driven.

Reference Signs List 1 Traveling vehicle body 2 Front wheel 2L Left front wheel 2R Right front wheel 3 Rear wheel 4 Work machine 5 Bonnet section 6 Control section 10 Traveling vehicle body main body 11 Steering post 12L Left support member 12R Right support member 13L Left support member 13R Right support member 15 Cushioning member 30 Electric motor (first electric motor)
40 Electric motor (second electric motor)
50 Battery 52 Battery bracket (bracket)
53L Left vibration-isolating member 53R Right vibration-isolating member 55L Left virtual line 55R Right virtual line

Claims (4)

A pair of left and right front wheels (2) are provided at the front of a traveling body (1), and a pair of left and right rear wheels (3) are provided at the rear of the traveling body (1);
A work vehicle having a bonnet section (5) in which a predetermined space is formed on the front side of the upper surface of the traveling body (1), and a control section (6) in which a driver rides is provided on the rear side of the bonnet section (5),
An electric motor (30) is provided to drive the rear wheel (3);
a battery (50) for storing power to be supplied to the electric motor (30) is provided in the bonnet portion (5);
A vehicle body (10) supporting the front wheels (2) has a left front-rear frame (10L) and a right front-rear frame (10R) extending in the front-rear direction,
The battery (50) is connected to the traveling vehicle body (10) via a left support member (12L) erected on the front of the left front/rear frame (10L) and a right support member (12R) erected on the front of the right front/rear frame (10R) . A battery bracket (52) having a left front-rear frame (52L) and a right front-rear frame (52R) extending in the front-rear direction is fixed to the battery (50);
a left support member (12L) provided on the left part of the traveling vehicle body (1) and the left front and rear frame (52L) are connected via a left vibration isolating member (53L);
a right support member (12R) provided on the right part of the traveling vehicle body (1) and the right front and rear frame (52R) are connected via a right vibration isolating member (53R);
2. A work vehicle as described in claim 1, wherein, when viewed from the front, the connecting portion of the left support member (12L) and the connecting portion of the left front and rear frame (52L) are formed with an upward incline toward the left, and the connecting portion of the right support member (12R) and the connecting portion of the right front and rear frame (52R) are formed with an upward incline toward the right. A work vehicle according to claim 2, in which, in a front view, the connecting portion of the left support member (12L) and the connecting portion of the left front and rear frames (52L) are formed perpendicular to a left imaginary line (55L) connecting the center of the left vibration-proof member (53L) and the center of the left front wheel (2L) of the front wheels (2), and the connecting portion of the right support member (12R) and the connecting portion of the right front and rear frames (52R) are formed perpendicular to a right imaginary line (55R) passing through the center of the right vibration-proof member (53R) and the center of the right front wheel (2R) of the front wheels (2). When viewed from the side, the traveling vehicle body (1) is formed of a traveling vehicle body main body (10) extending in the front-rear direction and a steering post (11) extending in the up-down direction and supporting a steering shaft (63) of the operation unit (6);
A buffer member (15) is provided at a predetermined interval in the left-right direction on the lower part of the front surface of the steering post (11),
The work vehicle according to any one of claims 1 to 3, wherein a tip end of the buffer member (15) is pressed against a rear surface of the battery (50).