electric work vehicle

Abstract

To enable a driver of a work vehicle to easily physically recognize a travelling state and a working state of the work vehicle, even when the work vehicle is of a battery driven type.SOLUTION: An electric work vehicle comprises: a support base 7 fixed to a vehicle body frame 2; an electric motor 5 fixed to the support base 7; a battery 4 that supplies the electric motor 5 with electric power; travelling devices 10 and 11 that are driven by the electric motor 5; a hydraulic pump 6 fixed to the support base 7; hydraulic equipment to which pressurized oil is supplied from the hydraulic pump 6; and a panel structure 8 arranged in front of a driver's seat and is connected to at least either of the vehicle body frame 2 and the support base 7.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a battery-driven type of electric work vehicle that is provided with traveling power by a motor driven by electric power supplied from a battery.

Background Art

[0002] Patent Document 1 discloses a battery-driven type of electric work vehicle including a working device, a battery, a motor driven by electric power supplied from the battery, a traveling device driven by the motor, and a hydraulic pump driven by the motor.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a battery-driven type of work vehicle, compared with a conventional engine-driven type of work vehicle, since the motor sound is quieter than the engine sound, the driver may not notice whether the motor is driving properly or at what rotational speed the motor is driving. The quietness of the motor sound is an advantage of the battery-driven type of work vehicle. However, since drivers accustomed to riding in engine-driven type of work vehicles utilize the engine rotation sound to grasp the traveling state and working state of the work vehicle, the quiet motor sound makes it difficult to grasp the traveling state and working state.

[0005] Therefore, there is a demand for an electric work vehicle of the battery-driven type in which the driver can easily grasp the traveling state and working state of the work vehicle in a tactile manner.

Means for Solving the Problems

[0006] The electric work vehicle according to the present invention comprises a machine frame, a support base fixed to the machine frame, an electric motor fixed to the support base, a battery that supplies power to the electric motor, a travel device driven by the electric motor, a hydraulic pump fixed to the support base, hydraulic equipment supplied with pressurized oil from the hydraulic pump, a driver's seat, and a panel structure positioned in front of the driver's seat, wherein the lower part of the panel structure is connected to at least one of the machine frame and the support base, and the upper part of the panel structure is connected to the upper part of the battery. The structure comprises a cover member that covers the battery and a support portion connected across the upper part of the panel structure and the upper part of the battery, wherein the cover member is attached to the support portion so as to be able to open and close around an opening and closing axis along the left-right direction.

[0007] The present invention is based on the inventor's observation that the operating noise (rotational noise) of a hydraulic pump is louder than the rotational noise of a motor, and that the operating noise of the hydraulic pump helps the operator understand the driving and working conditions of the work vehicle. In the configuration of the present invention, the electric motor and the hydraulic pump are fixed to the same support base which is fixed to the machine frame, and furthermore, a panel structure connected to at least one of the machine frame and the support base is positioned in front of the driver's seat. With this configuration, the operating noise of the hydraulic pump is transmitted as solid-conducted sound from the support base through the machine frame, or directly from the support base to the panel structure, and then directly from the panel structure to the operator's ears as air-conducted sound. Since the electric motor and the hydraulic pump are fixed to the support base, the operating noise of the hydraulic pump and the rotational noise of the electric motor are heard as almost the same sound source by the operator. Through this sound, the operator can intuitively understand the driving and working conditions of the work vehicle. In one preferred embodiment of the present invention, the lower part of the panel structure is connected to the aircraft frame via the support base. Yes, they are.

[0008] In one preferred embodiment of the present invention, the panel structure comprises a panel assembly to which a notification device for informing the driver of information is attached, and a panel support assembly that supports the panel assembly. In this configuration, a notification device (meter or display) for informing the driver of various information is attached to the panel assembly that emits the driving sound of the hydraulic pump. As a result, the driver can grasp the driving status and working status of the work vehicle by combining information from the notification device and the driving sound of the hydraulic pump transmitted from the panel assembly.

[0009] In one preferred embodiment of the present invention, the support base is a plate member, and the electric motor and the hydraulic pump are fixed to the same surface of the plate member. With this configuration, the rotational noise of the electric motor and the driving noise of the hydraulic pump are transmitted and integrated through the support base, which is made of a plate member with excellent conductivity for solid-borne sound, and are finally emitted from the panel assembly. As a result, even drivers accustomed to conventional engine-driven work vehicles can understand the driving and working conditions of the work vehicle through the driving noise of the hydraulic pump, just as in conventional vehicles.

[0010] In one preferred embodiment of the present invention, the electric motor and the hydraulic pump are cantilevered to the support base. This allows the rotational noise of the electric motor and the operating noise of the hydraulic pump to be well integrated and transmitted to the panel assembly as solid-conducted noise.

[0011] Overload on an electric motor may not be detectable solely by the rotational sound of the electric motor and the operating sound of the hydraulic pump. Therefore, in one preferred embodiment of the present invention, a motor load detection unit is provided that detects the overload on the electric motor and emits an overload detection signal. In response to the overload detection signal, at least one of a notification command to notify the driver of the occurrence of the overload and a load reduction command to reduce the overload are issued. In this configuration, if an overload occurs on the electric motor, the driver is notified of the occurrence of the overload by a buzzer, lamp, auditory message, visual message, etc., so that the driver can take appropriate action against the overload on the electric motor. Furthermore, when a load reduction command to reduce the overload is output, overload reduction processing is performed, such as motor control to increase the torque of the electric motor or reducing the gear ratio in the transmission, so that the overload on the electric motor is taken appropriate action. [Brief explanation of the drawing]

[0012] [Figure 1] This is a left side view of the tractor. [Figure 2] This is a left side view showing the arrangement of the tractor's powertrain. [Figure 3] This is a plan view showing the arrangement and mounting structure of the motor and hydraulic pump. [Figure 4] This is an exploded perspective view showing the arrangement and mounting structure of the motor and hydraulic pump. [Figure 5] This is a right side view showing the arrangement and mounting structure of the motor, hydraulic pump, and panel structure. [Figure 6] This is a front view showing the arrangement and mounting structure of the battery, motor, hydraulic pump, and cover components. [Figure 7] This is a perspective view showing the arrangement and mounting structure of the panel structure. [Figure 8] This is a functional block diagram showing the configuration of the control system. [Modes for carrying out the invention]

[0013] A mode for implementing the present invention will be described based on the drawings. In the following description, unless otherwise specified, the direction of arrow F in the drawing is defined as "front", the direction of arrow B as "rear", the direction of arrow L as "left", and the direction of arrow R as "right". Also, the direction of arrow U in the drawing is defined as "up", and the direction of arrow D as "down".

[0014] 〔Overall Configuration of Tractor〕 As an example of an electric work vehicle, a tractor will be described as one of the embodiments. As shown in FIG. 1, the tractor includes left and right front wheels 10, left and right rear wheels 11, and a cover member 12.

[0015] The tractor also includes a body frame 2 and a driver's cab 3. The body frame 2 is supported by the left and right front wheels 10 and the left and right rear wheels 11 as a traveling device.

[0016] The cover member 12 is disposed at the front of the body. And the driver's cab 3 is provided behind the cover member 12. In other words, the cover member 12 is disposed in front of the driver's cab 3.

[0017] The driver's cab 3 has a protection frame 30, a driver's seat 31, and a steering wheel 32. The driver can be seated on the driver's seat 31. Thereby, the driver can board the driver's cab 3. By operating the steering wheel 32, the left and right front wheels 10 are steered. The driver can perform various driving operations in the driver's cab 3.

[0018] The tractor includes a battery 4 which is a traveling battery. Also, the cover member 12 is configured to be swingable around an opening and closing axis Q along the left - right direction of the body. Thereby, the cover member 12 is configured to be openable and closable. When the cover member 12 is in the closed state, the battery 4 is covered by the cover member 12.

[0019] As shown in Fig. 2, the tractor includes an inverter 14 and an electric motor (hereinafter simply referred to as a motor) 5. The battery 4 supplies power to the inverter 14. The inverter 14 converts the DC power from the battery 4 into AC power and supplies it to the motor 5. Then, the motor 5 is driven by the AC power supplied from the inverter 14.

[0020] As shown in Fig. 2, the tractor is provided with a transmission 16 having a power transmission mechanism including a hydrostatic continuously variable transmission 15. The hydrostatic continuously variable transmission 15, also called HST, has an HST pump 15a and an HST motor 15b. The HST pump 15a is driven by the rotational power from the motor 5. When the HST pump 15a is driven, rotational power is output from the HST motor 15b. The hydrostatic continuously variable transmission 15 is configured such that the rotational power can be reversely rotated and continuously variable between the HST pump 15a and the HST motor 15b.

[0021] The rotational power output from the HST motor 15b is transmitted to the transmission 16. The rotational power transmitted to the transmission 16 is distributed to the left and right rear wheels 11 via the rear-wheel differential gear mechanism. Since this tractor is of the four-wheel drive type, the rotational power from the transmission 16 is distributed to the left and right front wheels 10 via the front-wheel drive shaft 9 and the front-wheel differential gear mechanism. Thereby, the left and right front wheels 10 and the left and right rear wheels 11 are driven.

[0022] Also, as shown in Fig. 2, the tractor is provided with a mid PTO shaft 17 and a rear PTO shaft 18. The rotational power output from the motor 5 is distributed to the HST pump 15a, the mid PTO shaft 17, and the rear PTO shaft 18 in the transmission 16. Thereby, the mid PTO shaft 17 and the rear PTO shaft 18 rotate.

[0023] The rotational power of the mid-PTO shaft 17 or the rear PTO shaft 18 drives the work device connected to the mid-PTO shaft 17 or the rear PTO shaft 18. For example, in this embodiment, as shown in Figure 2, a grass cutting device 19 is connected to the mid-PTO shaft 17, and the rotational power of the mid-PTO shaft 17 drives the grass cutting device 19.

[0024] As shown in Figure 3, the tractor is equipped with a hydraulic pump 6 alongside the motor 5. The hydraulic pump 6 is driven by the motor 5. The hydraulic pump 6 also supplies pressurized oil to hydraulic actuators (a type of hydraulic equipment) installed on the tractor and hydraulic actuators installed on work devices attached to the tractor.

[0025] As shown in Figure 4, the motor output shaft 51 of the motor 5 and the pump input shaft 61 of the hydraulic pump 6 extend in the longitudinal direction of the machine body. A support base 7, which is a plate member, is fixed to the machine frame 2, and the motor 5 and hydraulic pump 6 are fixed to the front surface of the support base 7. Specifically, the motor bracket 50 attached to the motor 5 and the front surface of the support base 7 are in surface contact and bolted together, and the pump bracket 60 attached to the hydraulic pump 6 and the front surface of the support base 7 are in surface contact and bolted together. In other words, the motor 5 and hydraulic pump 6 are cantilevered and supported on the same surface of the support base 7.

[0026] Furthermore, a gear transmission mechanism 70 that transmits power from the motor 5 to the hydraulic pump 6 is located on the rear surface of the support base 7. The gear transmission mechanism 70 consists of an output gear 71 attached to the motor output shaft 51 of the motor 5, an input gear 72 attached to the pump input shaft 61 of the hydraulic pump 6, and a gear train 73 that interlocks the output gear 71 and the input gear 72. The support base 7 has a base cover 7a that covers its rear surface, and the base cover 7a is bolted to the support base 7. The gear transmission mechanism 70 is housed in the space created by the support base 7 and the base cover 7a.

[0027] With the above configuration, power from the motor 5 is transmitted to the hydraulic pump 6 via the gear transmission mechanism 70, and when the motor 5 is driven, the hydraulic pump 6 is also driven.

[0028] As shown in Figure 5, a plate-shaped inverter support section 41 for supporting the inverter 14 is fixed to the aircraft frame 2. Furthermore, a plate-shaped battery support section 40 for supporting the battery 4 is fixed by a plurality of front supports 42 provided on the inverter support section 41 and a rear support 43 provided on the support base 7. The rear support 43 is a box-shaped structure made up of a plurality of plates.

[0029] As shown in Figure 5, a panel structure 8 covering the handle post 33 is positioned behind the cover member 12. The cover member 12 is supported by a first support portion 81 and a second support portion 82. The panel structure 8 consists of a panel assembly 8A and a panel support assembly 8B that supports the panel assembly 8A. The panel assembly 8A includes a main panel 85 and an upper panel 86. The panel support assembly 8B includes a vertical support frame 83 and a stay unit 84 consisting of a plurality of stay members.

[0030] As shown in Figure 6, the cover member 12 has a gate-shaped frame portion 12f and a connecting portion 12g when viewed from the front. The frame portion 12f is provided on the inner wall side of the cover member 12. The connecting portion 12g protrudes downward from the lower surface of the upper end of the frame portion 12f. The second support portion 82 is configured in a gate shape that straddles the upper end surface 4a of the battery 4, and the lower end of the second support portion 82 is fixed to the battery 4.

[0031] As shown in Figure 6, the first support portion 81 is a projection extending upward from the upper surface of the upper end of the second support portion 82. The first support portion 81 and the connecting portion 12g are connected by a pin, thereby allowing the cover member 12 to swing up and down around the opening / closing axis Q.

[0032] Furthermore, left and right side covers 13 are provided below the left and right side walls of the cover member 12. The side covers 13 have a grille 13a (see Figure 1) through which air can pass.

[0033] As shown in Figure 5, the front of the driver's unit 3 is provided with a main panel 85 and a display unit 80 (corresponding to the "notification device" according to the present invention). The display unit 80 is mounted on the top panel portion 85a of the main panel 85. The display unit 80 can notify the driver of various types of information.

[0034] As shown in Figures 5 and 7, a vertical support frame 83 is provided between the driver unit 3 and the battery 4. The vertical support frame 83 is supported by the aircraft frame 2 via a rear support 43 and a support base 7, etc. The vertical support frame 83 is configured in a gantry shape and extends in the vertical direction of the aircraft.

[0035] A stay unit 84 is connected to the upper surface of the vertical support frame 83. The upper and lower parts of the top panel portion 85a of the main panel 85 are attached to the stay unit 84. The main panel 85 is supported by the vertical support frame 83 via the stay unit 84. In addition, the second support portion 82 and the vertical support frame 83 are connected via the stay unit 84.

[0036] Multiple horizontal plates 83a, which function as crossbeams of the vertical support frame 83, are fitted with an electronic control unit (ECU) that controls the tractor. The electronic control unit (ECU) is located between the top panel portion 85a of the main panel 85 and the vertical support frame 83.

[0037] As shown in Figure 8, this tractor is equipped with an electronic control unit (ECU) containing a control unit 100 that controls the behavior of the motor 5 and changes in the transmission state of the transmission 16. The transmission 16 includes a hydrostatic continuously variable transmission 15, a gear shifting mechanism 16A, and a PTO mechanism 16C. The control unit 100 includes a motor control unit 101, a travel control unit 102, and a work control unit 103. The motor control unit 101 controls the output rotational speed of the motor 5 by controlling the inverter 14. The travel control unit 102 provides control signals to the actuators of the hydrostatic continuously variable transmission 15 and the gear shift mechanism 16A to change the shifting state, such as the gear ratio. The work control unit 103 provides control signals to the actuator of the PTO mechanism 16C to change the power transmission state to the work equipment.

[0038] The motor control unit 101 is equipped with a motor load detection unit 1011 that detects excessive load on the motor 5 and emits an excessive load detection signal. The control unit 100 generates a notification command to notify the motor 5 of the occurrence of excessive load in response to the excessive load detection signal output from the motor load detection unit 1011, and provides an excessive load warning through the display unit 80 and other notification devices such as buzzers and lights. The control unit 100 also generates a load reduction command in response to the excessive load detection signal to reduce the excessive load on the motor 5. In response to this load reduction command, the motor control unit 101 controls the motor 5 to increase its torque, or the driving control unit 102 changes the power transmission state of the hydrostatic continuously variable transmission 15, gear shifting mechanism 16A, and PTO mechanism 16C to reduce the load on the motor 5. Of course, both load reduction measures may be performed.

[0039] [Another embodiment] (1) In the embodiment described above, the motor 5 and the hydraulic pump 6 were fixed to the same surface of the support base 7, but they may be fixed to different surfaces.

[0040] (2) In the above-described embodiment, the motor 5 and the hydraulic pump 6 were fixed to the support base 7, but the support base 7 may be divided and each part fixed to a separate divided support base.

[0041] (3) In the above-described embodiment, the sound (vibration) generated by the motor 5 and the hydraulic pump 6 is transmitted as solid-conducted sound originating from the support base 7 and emitted by the panel structure 8. Alternatively, a waveguide or the like may be used in at least part of the transmission path of the sound generated by the motor 5 and the hydraulic pump 6.

[0042] (4) Depending on the work environment, quietness may be required. To prepare for such cases, it is desirable that sound (vibration) absorbing material be selectively inserted into the path of solid-borne sound in order to reduce the noise of the motor 5 and hydraulic pump 6 as much as possible. In this case, it would be convenient if the attachment and detachment of the sound (vibration) absorbing material to and from the propagation path could be done by lever operation or the like.

[0043] Furthermore, the configurations disclosed in the above embodiments (including other embodiments, the same applies hereinafter) can be applied in combination with configurations disclosed in other embodiments, as long as no inconsistencies arise. Moreover, the embodiments disclosed herein are illustrative, and the embodiments of the present invention are not limited thereto, and can be modified as appropriate without departing from the object of the present invention. [Industrial applicability]

[0044] This invention can be used not only for tractors, but also for various electric work vehicles such as combine harvesters, rice transplanters, construction machinery, and off-road vehicles. [Explanation of Symbols]

[0045] 2: Aircraft Frame 3: Driver's Unit 4: Battery 5: Motor (electric motor) 6: Hydraulic pump 7: Support base 8: Panel structure 8A: Panel Assembly 8B: Panel support assembly 12: Cover component 17: Mid-PTO axis 18: Rear PTO shaft 31: Driver's seat 32: Steering wheel 33: Handlebar post 80: Display Unit 81: 1st support part (support part) 82:Second support part (support part) 83: Vertical support frame 85: Main Panel

Claims

1. The aircraft frame and A support base fixed to the aforementioned aircraft frame, An electric motor fixed to the aforementioned support base, A battery that supplies power to the electric motor, A traveling device driven by the aforementioned electric motor, A hydraulic pump fixed to the aforementioned support base, A hydraulic device supplied with pressurized oil from the aforementioned hydraulic pump, The driver's seat and The system comprises a panel structure positioned in front of the driver's seat, The lower part of the panel structure is connected to at least one of the aircraft frame and the support base, and the upper part of the panel structure is connected to the upper part of the battery. The cover member that covers the battery, It comprises a support portion connected across the upper part of the panel structure and the upper part of the battery, An electric work vehicle in which the cover member is attached to the support portion so as to be able to open and close around an opening and closing axis that is aligned in the left-right direction.

2. The electric work vehicle according to claim 1, wherein the lower part of the panel structure is connected to the machine frame via the support base.

3. The electric work vehicle according to claim 1, wherein the panel structure comprises a panel assembly to which a notification device for notifying the driver of information is attached and a panel support assembly that supports the panel assembly.

4. The electric work vehicle according to claim 1, wherein the support base is a plate member, and the electric motor and the hydraulic pump are fixed to the same surface of the plate member.

5. The electric work vehicle according to claim 1, wherein the electric motor and the hydraulic pump are cantilevered to the support base.

6. An electric work vehicle according to any one of claims 1 to 5, further comprising a motor load detection unit that detects an excessive load on the electric motor and emits an excessive load detection signal, wherein in response to the excessive load detection signal, at least one of a notification command to notify the occurrence of the excessive load and a load reduction command to reduce the excessive load is emitted.

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