JP5826037B2 - Electric tractor - Google Patents

Description

  The present invention includes an electric traveling motor capable of driving a traveling device for a vehicle body, a PTO shaft for transmitting a driving force to a working device coupled to the vehicle body, and an electric working motor capable of rotationally driving the PTO shaft. The present invention relates to an electric tractor including a control unit capable of driving and controlling the traveling motor and the working motor.

  Conventionally, as this type of electric tractor, the traveling motor is provided exclusively to drive the traveling device of the vehicle body, while the working motor is provided exclusively to rotationally drive the PTO shaft, The control means is configured to drive and control the driving motor for driving the vehicle body, and to drive and control the working motor for driving the working device connected to the vehicle body (for example, Patent Documents). 1).

Japanese Patent Laid-Open No. 7-300022 (FIGS. 1 and 2)

According to the conventional electric tractor described above, when traveling straight on a flat part such as a farm field, the load acting on the traveling motor is a relatively small value, for example, when turning to change the course And when going up a slope to escape from the field, a large load acts.
Therefore, when selecting the motor for traveling, it is necessary to mount a motor having a large output in accordance with the maximum load so as to be able to cope with such a large load as described above.
On the other hand, when selecting a work motor, it was necessary to mount a work motor with a large output so as to cope with a large load caused by farm work.
As a result, both the traveling motor and the working motor are increased in size, so that the installation space on the vehicle body becomes wide, making it difficult to make the vehicle body compact and increasing the cost.

  Accordingly, an object of the present invention is to provide an electric tractor that solves the above-mentioned problems and that can reduce the size of the motor while ensuring the necessary driving force, and that can achieve cost reduction.

A first characteristic configuration of the present invention is an electric traveling motor capable of driving a traveling device for a vehicle body, a PTO shaft for transmitting a driving force to a working device connected to the vehicle body, and a rotational drive for the PTO shaft. An electric tractor comprising an electric work motor, and a control means capable of driving and controlling the travel motor and the work motor, wherein the drive transmission transmits the driving force of the work motor to the travel device. The drive transmission means includes a switching gear that is integrally rotatable with the drive shaft of the working motor and is movably fitted along the drive shaft; A PTO drive state in which the switching gear meshes only with the transmission gear on the PTO shaft side, and only the transmission gear with which the switching gear is provided on the driving shaft of the traveling motor. Mesh with Yes and configured to be capable of switching to the running drive state, the control means, with the operation that leads to a stop of the PTO shaft, wherein the drive as before Symbol driving force of the working motor is transmitted to the running device transmission means in time and switches to the running drive state.

According to the first characteristic configuration of the present invention, as the operation leading to the stop of the PTO shaft is performed, the drive transmission unit is operated by the control unit so that the driving force of the work motor is transmitted to the traveling device. It can be driven and controlled.
Accordingly, by operating the drive transmission means, the driving device is driven by the driving force of the working motor, or the driving device is driven by adding the driving force of the working motor to the driving force of the driving motor. Will be able to.

Since the operation of the drive transmission means is performed in a state where the operation of stopping the PTO shaft that transmits the driving force to the work device is performed, the output of the work motor originally used for driving the work device is Even if it is all turned to the traveling device, the working device is not hindered, and the driving force of the working motor can be utilized for traveling the vehicle body without waste.
Examples of stopping the PTO shaft include, for example, turning the electric tractor, raising the slope to escape from the field, etc. In these situations, the load on the traveling motor is particularly high. Since it acts greatly, it is possible to generate a sufficient driving force by turning the driving force of the working motor to the traveling device.

  Therefore, even if the traveling motor is configured with a small output corresponding to a small load during linear traveling in a normal state, the driving force of the working motor is applied to the traveling device during each traveling described above that requires a large output. As a result, it becomes possible to drive with a large output, and as a result, while driving with a small load or driving with a large load, the necessary driving force is ensured, respectively. It is possible to achieve both downsizing, space saving associated therewith, and cost reduction.

  Incidentally, the “operation leading to the stop of the PTO shaft”, which is a condition for the control means to operate the drive transmission means, is a direct operation such as “clutch disconnection operation” between the work motor and the PTO shaft. Or includes an indirect operation in which the PTO axis stops in conjunction with an operation on another device.

  As an example of the “indirect operation”, in an electric tractor provided with interlocking means for stopping the PTO shaft in conjunction with the operation, for example, an elevating mechanism provided in the vehicle body with a work device connected to the vehicle body Means "lifting operation" to float from the ground by means of, or "steering operation" that largely turns the steering wheel as the vehicle turns, and the interlocking means stops the PTO shaft in conjunction with these operations become.

  According to a second feature of the present invention, there is provided an elevating mechanism for elevating and driving the work device connected to the vehicle body, and interlocking means for stopping the PTO shaft in conjunction with an operation for elevating the elevating mechanism. It is in place.

  According to the second characteristic configuration of the present invention, the interlocking means can stop the PTO shaft as the working device is raised by the lifting mechanism, and as a result, the drive transmission means is operated by the control means. Thus, the driving force of the work motor can be transmitted to the traveling device.

Therefore, the driver of the electric tractor can transmit the driving force of the work motor to the traveling device only by raising the lifting mechanism without driving the plurality of devices, for example, Sufficient driving force can be generated even when the electric tractor that is heavily loaded with the traveling motor is turned, or when the slope is raised to escape from the field.
As a result, the turning of the electric tractor and the traveling on the slope can be performed speedily.

Right side view of electric tractor Top view of electric tractor Block diagram showing the main configuration of the electric tractor Schematic diagram showing the transmission mechanism Schematic diagram showing the operation of the switching clutch The block diagram which shows the main structures of the electric tractor of another embodiment

  Hereinafter, an embodiment of an electric tractor according to the present invention will be described with reference to the drawings.

  As shown in FIGS. 1 and 2, the electric tractor exemplified in this embodiment includes left and right front wheels (corresponding to the traveling device R) 1 as steering wheels and left and right rear wheels (corresponding to the traveling device R) as driving wheels. ) 2 and a pair of left and right lift arms (corresponding to a lifting mechanism) 3 that swings up and down by the operation of a hydraulic lift cylinder (not shown) and the outside of the working power. It is equipped with a PTO shaft 4 and the like that make it possible to take out. As a result, this electric tractor can be connected to a working device (not shown) such as a rotary tiller or plow so that it can be driven up and down and supplied to a drive-type working device such as a rotary tiller. It is configured so that the power to be taken out can be taken out.

  A boarding operation unit 5 is formed in the rear half of the vehicle body T. The boarding operation unit 5 includes a key-operated main switch 6, a steering wheel 7 for front wheel steering, an accelerator pedal 8 that automatically returns to the depression release position, a position-retaining vehicle speed setting lever 9, and a position-retaining forward / reverse switching. Various operating tools such as a lever 10, a pair of left and right brake pedals 11 that automatically return to the depression release position, a position-retaining parking brake lever 12, a position-retaining lift lever 13, and a position-retaining PTO lever 14 And a driver's seat 15. The driver's seat 15 is configured to be able to change the position between a use position where the seating can be performed and a non-use position where the seating is prevented by a swinging operation using the left and right support shaft 16 provided at the front thereof as a fulcrum. .

As shown in FIGS. 2 and 3, the left and right rear wheels 2 are driven by a traveling motor 17.
Various hydraulic actuators such as a lift cylinder are provided with an electro-hydraulic control unit 20 including various hydraulic devices such as an electromagnetic control valve (not shown) that controls the flow rate of oil from a hydraulic pump 19 driven by a pump motor 18. It drives properly by controlling through the
The PTO shaft 4 is driven by a work motor 21.
AC motors are employed for the traveling motor 17, the pump motor 18, and the work motor 21.
The traveling motor 17 has an output setting corresponding to the load associated with the straight traveling in the field, while the working motor 21 is not only loaded during the field work but also during the turning operation. The output is set so as to correspond to a large load that acts when escaping from the field, and the work motor 21 uses a higher output than the travel motor 17.

This electric tractor is equipped with a control device (control means) 100 composed of a plurality of electronic control units equipped with a microcomputer or the like.
The control device 100 is activated by the electric power from the charge / discharge battery 22 or the auxiliary battery 23 obtained by operating the main switch 6 to the “ON” position or “CHARGE” position. Further, when the power from the battery 22 or the auxiliary battery 23 is cut off by the operation of the main switch 6 to the “off” position, a power supply state is maintained for a predetermined time by a self-holding circuit (not shown) provided therein. Are stored in the EEPROM at the stage when the main switch 6 is operated to the “OFF” position, and then the power supply by the self-holding circuit is stopped and the operation is stopped with a lapse of a predetermined time.

Electric power from the battery 22 or the auxiliary battery 23 is supplied to the motors 17, 18, and 21 through the drive control unit 24 of the control device 100. The drive control unit 24 controls the amount of power supplied to each of the motors 17, 18, and 21 based on a control command from the operation control unit 25 of the control device 100 that controls the operation of the electrohydraulic control unit 20 and the like. Each motor 17, 18, 21 is driven appropriately. Based on information from the information management unit 26 of the control device 100 that manages output information from information output means such as various switches and sensors, the operation control unit 25 sends a control command suitable for the information to the electrohydraulic control unit. 20 and the drive control unit 24.
The interlocking means 54 of the control device 100 is configured to disconnect the PTO clutch 55 and stop the PTO shaft 4 in conjunction with the raising operation of the lifting mechanism 3 by the lifting lever 13 based on information from the information management unit 26. ing. Specifically, it is assumed that the lifting lever 13 has been lifted by detecting that the lifting lever 13 is in the lifting operation position by the lifting sensor 33. Therefore, in this embodiment, the raising operation of the elevating lever 13 is a form of “an operation that leads to the stop of the PTO shaft 4”.

  The drive control unit 24, the operation control unit 25, the information management unit 26, the interlocking unit 54, and the like are connected so as to be capable of mutual communication and power supply via an in-vehicle LAN or an in-vehicle power line.

  The information managed by the information management unit 26 includes the operation position of the main switch 6, the depression amount of the accelerator pedal 8 detected by the accelerator sensor 27, the operation position of the vehicle speed setting lever 9 detected by the vehicle speed setting sensor 28, and the forward / reverse sensor The operation position of the forward / reverse switching lever 10 detected by 29, the operation angle from the straight position of the pitman arm 31 detected by the steering angle sensor 30 as the steering angle of the front wheel 1 inside the turn, and the parking brake lever detected by the parking brake switch 32 12, the operation position of the elevating lever 13 detected by the elevating sensor 33, the operation position of the PTO lever 14 detected by the PTO sensor 34, the presence / absence of seating on the driver seat 15 detected by the seating sensor 35, and the seat switch 36 The operation position of the driver's seat 15 detected by.

  From the above configuration, the control device 100 controls the rotational speed of the traveling motor 17 based on the depression amount of the accelerator pedal 8 and the operation position of the vehicle speed setting lever 9 and the operation position of the forward / reverse switching lever 10. Based on the above, the forward / backward switching control for switching the rotation direction of the traveling motor 17, the up / down control for moving the lift arm up / down based on the operation position of the up / down lever 13, the operation position of the PTO lever 14 and the up / down lever 13 The PTO drive control for switching the PTO shaft 4 between the operating state and the stopped state by operating the PTO clutch 55 (see FIG. 4) based on the operation position of the PTO shaft 4 and the stop operation of the PTO shaft 4 will be described later. For example, clutch switching control for switching the switching clutch 53 to the traveling device R side can be performed.

  The drive control unit 24 includes a power supply switching unit 37, a power supply switching unit 38, a pump inverter 39, a travel inverter 40, and a work inverter 41. Based on the power supply switching command from the operation control unit 25, the power supply switching unit 37 switches between a state where the power source is the battery 22, a state where the auxiliary battery 23 is used, and a state where both are used. The power supply switching unit 38 is configured to supply power to the pump inverter 39 based on the power supply switching command from the operation control unit 25, to supply power to the pump inverter 39 and the traveling inverter 40, and to the pump inverter 39. And it switches to the state supplied to the inverter 41 for work, and the state supplied to each inverter 39-41. The pump inverter 39 supplies power to the pump motor 18 to drive the hydraulic pump 19 appropriately. The traveling inverter 40 controls the drive control current (for example, PWM signal) supplied to the traveling motor 17 based on the speed command from the operation control unit 25 to appropriately change the rotational speed of the traveling motor 17. The work inverter 41 controls the current supplied to the work motor 21 to appropriately drive the rotation speed of the work motor 21.

  FIG. 4 shows how the driving force is transmitted to each driving object using the traveling motor 17 and the work motor 21 as driving sources.

The output of the traveling motor 17 is output from a gear-type transmission 50 functioning as a sub-transmission configured to be able to switch between three stages of high, middle and low, a front wheel differential 51 or a rear wheel differential 52, etc. Via the left and right front wheels 1 and the left and right rear wheels 2.
The output of the work motor 21 can be switched and transmitted to the PTO shaft 4 side or the traveling device R side by a switching clutch (an example of drive transmission means) 53.

  As shown in FIG. 5, an example of the structure of the switching clutch 53 is provided with a switching gear 53 a that is spline-fitted to the drive shaft 21 a of the working motor 21, and the input shaft 55 a of the PTO clutch 55 and the traveling motor 17. The drive shaft 17a is provided with transmission gears 53b and 53c, which are screwable with the switching gear 53a, in a state of being displaced in the axial direction of the drive shaft 21a. The switching gear 53a is moved along the spline and screwed into one of the two transmission gears 53b and 53c, so that the driving force of the work motor 21 can be adjusted to the PTO shaft 4 side, the traveling device R side, You can switch to

As described above, the switching clutch 53 is switched based on on / off operation position information of the PTO lever 14 by the PTO sensor 34 of the information management unit 26 and operation position information of the lifting lever 13 by the lifting sensor 33. This is implemented by clutch switching control by the device 100.
During normal work for driving the work device, the switching clutch 53 is switched so that the driving force is transmitted to the PTO shaft 4 side (see FIG. 5A). On the other hand, for example, in the case of turning the tractor or trying to escape from the field, the lift arm 3 is raised. In conjunction with this operation, the PTO clutch 55 is turned off and the PTO shaft 4 is stopped. The switching clutch 53 is switched so that the driving force is transmitted to the traveling device R side (see FIG. 5B).
Accordingly, as the PTO shaft 4 is stopped, the driving force is transmitted from both the traveling motor 17 and the working motor 21 to the traveling device R side so that it can appropriately cope with traveling with a heavy load. Become.
When the lift arm 3 is lowered while the PTO lever 14 is on, the PTO clutch 55 is engaged and the switching clutch 53 is switched so that the driving force is transmitted to the PTO shaft 4 side.

  According to the electric tractor of the present embodiment, even when the traveling motor 17 is configured with a small output corresponding to a small load during straight running in a normal state, when a large output is required (for example, during turning) Or when escaping from the field), the driving force of the work motor 21 can be applied to the traveling device R to drive the vehicle with a large output. It is possible to achieve a reduction in the size of the traveling motor 17, a space saving associated therewith, and a cost reduction while securing the necessary driving force during traveling in which the vehicle operates.

[Another embodiment]
Other embodiments will be described below.

<1> The PTO shaft 4 is not limited to the rotary tiller or plow described in the previous embodiment as a working device to be connected and driven, but may be another driving type working device.
<2> The “operation leading to the stop of the PTO shaft 4” when executing the operation of the drive transmission means 53 by the control means 100 is limited to the raising operation of the lifting mechanism 3 by the lifting lever 13 described in the previous embodiment. For example, as shown in FIG. 6, when adopting a configuration in which the interlocking unit 54 is omitted, the PTO lever 14 is turned off as “an operation that leads to the stop of the PTO shaft 4”.
As another example, when the steering angle detected by the rudder angle sensor 30 exceeds a set value as the steering wheel 7 is operated, it is assumed that a turning operation has been performed and the lifting mechanism 3 is automatically operated. And the PTO shaft 4 may be configured to stop. In this case, the operation of turning the steering wheel 7 by turning the steering wheel 7 greatly becomes “the operation that leads to the stop of the PTO shaft 4”. Then, the switching clutch 53 is switched to the traveling device R side, and the driving force of the work motor 21 can be transmitted to the traveling device R side.
As another example, the switching clutch 53 may be an operation itself for directly switching from the PTO shaft 4 side to the traveling device R side by a manual operation.
<3> The traveling motor 17, the work motor 21, and the pump motor 18 are not limited to the AC motors described in the previous embodiment, and for example, a DC motor may be employed.
<4> The traveling device R is not limited to the configuration of the front wheel 1 and the rear wheel 2 described in the previous embodiment, and may be configured of, for example, a crawler traveling device. In this case, it may be a series of crawler travel devices before and after, or the rear wheel 2 may be changed to a crawler travel device.

  In addition, as mentioned above, although the code | symbol was written in order to make contrast with drawing convenient, this invention is not limited to the structure of an accompanying drawing by this entry. In addition, it goes without saying that the present invention can be carried out in various modes without departing from the gist of the present invention.

  The electric tractor can be used by connecting various drive-type work devices.

3 Lift arm (equivalent to lifting mechanism)
4 PTO shaft 17 traveling motor 21 working motor 53 switching clutch (an example of drive transmission means)
54 Interlocking means 100 Control device (control means)
R traveling device T car body

Claims (2)

An electric traveling motor capable of driving the traveling device of the vehicle body;
A PTO shaft for transmitting a driving force to a working device connected to the vehicle body;
An electric work motor capable of rotationally driving the PTO shaft;
An electric tractor comprising a control means capable of driving and controlling the traveling motor and the working motor,
Drive transmission means for transmitting the driving force of the working motor to the traveling device;
The drive transmission means includes a switching gear that is integrally rotatable with the driving shaft of the working motor and is movably fitted along the driving shaft, and the switching gear is used to drive the working motor. By moving along the shaft, the PTO driving state where the switching gear meshes only with the transmission gear on the PTO shaft side, and the traveling where the switching gear meshes only with the transmission gear provided on the driving shaft of the traveling motor. It can be switched to the driving state,
It said control means, said with the operation leading to the stopping of the PTO shaft, said drive transmitting means the dynamic tractor conductive switching to the running drive state as before Symbol driving force of the working motor is transmitted to the traveling device. An elevating mechanism for elevating and driving the working device connected to the vehicle body;
The electric tractor according to claim 1, further comprising interlocking means for stopping the PTO shaft in conjunction with an operation of raising the lifting mechanism.

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