JPH07300022A - Motor-driven type tractor - Google Patents

Abstract

PURPOSE:To provide an agricultural tractor decreasing an influence by load fluctuation further with small vibration and noise, relating to the tractor capable running and PTO driving utilizing an AC motor. CONSTITUTION:A running system AC motor 4 and a PTO system AC motor 12 are separately provided respectively in front/rear parts of a machine body, and a tractor is constituted so as to perform a running system and PTO system speed change by adjusting rotational speed of these motors, also to arrange a plurality of batteries 16 in the periphery of the motor.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor driven agricultural tractor.

[0002]

2. Description of the Related Art Conventionally, most agricultural tractors have been
A diesel engine is mounted on the front of the machine, and a radiator, muffler, battery, etc. are arranged around this engine, and a transmission is installed in the mission case at the rear of the machine to change gears. It was configured to transmit the rotational power appropriately decelerated by the device to the front wheels and the rear wheels.

[0003]

By the way, in the above-mentioned conventional apparatus, many expensive parts such as a radiator and a muffler are required, and the drawbacks such as a high manufacturing cost as a whole and vibration are caused. There was a drawback that the work environment was deteriorated due to the loud noise. In addition, small tractors sometimes go into the house for management work.
In such a work, there is a problem that exhaust gas is trapped in the house and the work cannot be performed for a long time.

[0004]

The present invention has been proposed in view of the above problems, and the following technical means have been taken. That is, it is a tractor having front wheels 2 and rear wheels 3 at the front and rear of the machine body, and is provided with the traveling system motor 4 and the PTO system motor 12 mounted on the machine body to provide the traveling system of the tractor. The speed change and the speed change of the PTO system are performed by adjusting the rotational speeds of the motors 4 and 12, and a plurality of batteries 16 are arranged around the motors 4 and 12. This is a motor-driven tractor.

[0005]

Embodiments of the present invention will be described below based on the embodiments shown in the drawings. First, the structure will be explained as follows.
Is a tractor having front wheels 2 and rear wheels 3 at the front and rear parts of the machine body, a traveling system AC motor 4 is mounted at the front part of the machine body, and a traveling system reduction gear box 5 is mounted at the rear part thereof. .
It is configured to transmit the rotational power that has been appropriately reduced in the traveling system reduction gear box 5 to the front wheels 2 and the rear wheels 3.

A hydraulic pump 8 and a hydraulic tank 9 are provided at the upper rear portion of the reduction gear box 5 for vertically moving the lift mechanism 6 at the rear portion of the machine body. Then, the hydraulic oil in the hydraulic tank 9 is transferred to the rear transmission case by the hydraulic pump 8.
It is sent to a hydraulic cylinder (not shown) provided in the space 10, and the lift mechanism 6 is rotated up and down. Below the seat 11, a PTO AC motor 12 is mounted, and its output shaft is connected to the rear mission case 10. Rear
A PTO projectingly mounted on the rear end of the mission case 10
The shaft 15 is rotationally driven via a PTO reduction gear mechanism (not shown) incorporated in the rear mission case 10.

In FIGS. 1 and 2, reference numeral 16 is a battery
The batteries 16 are arranged symmetrically on the body frame 18 so that the balance in the left-right direction is maintained well. Reference numeral 20 is a control controller for controlling the rotation of the two AC motors 4 and 12. An upper part of the control controller 20 and the traveling system AC motor 4 is covered with a bonnet 22, and a solar cell 24 is attached to an upper surface part of the hood 22 and a fender 23 covering the upper part of the rear wheel 3. There is. The solar cell 24 is installed for the purpose of supplying the battery-16 with electric power stored in the daytime.

In FIG. 3, reference numerals 25 and 26 are left and right brake pedals, 27 is a traveling speed adjusting pedal, 28 is a speedometer, and 2 is a speedometer.
Reference numeral 9 is a PTO tachometer, and 30 is an indicator showing the battery capacity. On the lateral side of the seat 11, there are provided a forward / reverse switching lever 33 for switching the forward / backward movement of the body, a rotation speed setting dial 35 for setting the PTO rotation speed, a lift operation lever 36 for vertically operating the working machine, and the like. Has been. The traveling speed adjusting pedal 27 is configured so that the rotational speed of the traveling system AC motor 4 changes according to the amount of depression thereof, and the PTO system rotational speed setting dial 35 is rotated by an operator. Then, the rotation speed of the PTO shaft 15 is set.

The rotation speed adjustment in this embodiment adopts a method of changing the frequency, and the traveling system
Both the PTO system have a configuration in which the rotation speed can be adjusted steplessly, but the rotation speed may be adjusted stepwise. FIG. 4 is a block diagram for achieving the rotational speed control. To briefly explain the configuration, the amount of depression of the traveling speed adjusting pedal 27 is provided on the input side of the microcomputer unit 40 that constitutes the control controller 20. The detection sensor 41, the brake pedal depression amount detection sensors 42, 43, the operation detection SW 44 of the forward / reverse switching lever 33, the PTO setting dial 35, the PTO rotation sensor 46, the vehicle speed sensor 47,
A battery-16, a solar cell 24, etc. are connected.

On the other hand, on the output side of the microcomputer unit 40, a battery-indicator 30, a PTO tachometer 29,
Along with the speedometer 28, AC motors 4 and 12 for the traveling system and the PTO system are connected. In the figure, battery-1
6 and the AC motors 4 and 12 between the forward and reverse units 50 and 51 for changing the rotating direction of the AC motors 4 and 12.
And DC / AC converters 53, 54 for converting direct current to alternating current
Also, the counter electromotive force from the AC motors 4 and 12 is supplied to the battery-
AC / DC converter 5 for power recovery for recovery to 16
6, 57 are provided.

Then, according to the control flow shown in FIG.
The rotation speed of the AC motor 4 for the traveling system and the rotation speed of the PTO AC motor 12 are controlled. The rotation speed control of the traveling system AC motor will be described with reference to the flowchart of FIG. When working or traveling on the road, the frequency of the AC motor 4 is set according to the depression amount of the traveling speed adjusting pedal 27 (step S1). When both the left and right brake pedals 25 and 26 are not stepped on and the brake flag is not set, the frequency becomes the initial setting value of the traveling AC motor 4 and the forward / reverse switching lever is set. The aircraft is moved forward and backward according to the state of 33. That is, if the forward / reverse switching lever 33 is tilted forward, the forward / reverse unit 50 is switched to the forward rotation side (step S7). Conversely, if the forward / reverse switching lever 33 is tilted backward, the forward / reverse unit 50 is moved to the reverse rotation side. Switching (step S8), DC / AC converter 53
The set frequency is output to drive the AC motor 4 at the set rotation speed (step S9).

Left and right brake pedals 2 to stop the aircraft
When 5 and 26 are connected and stepped on at the same time, the frequency is changed to reduce the vehicle speed. In this case, the frequency for decelerating the running AC motor 4 is reset according to the depression amount of the brake pedals 25 and 26 (step S3), and the brake flag is set at the same time. Is stored (step S4). Then, as in the case described above, the vehicle body stops, moves forward, or moves backward in accordance with the position of the forward / reverse switching lever 33.

Even if the brake pedals 25 and 26 are released, the decelerated speed is prioritized. Therefore, in order to cancel the speed, the operator once depresses the traveling speed adjusting pedal 27 to the deceleration side, A so-called safety operation is required to match the speed (frequency) setting by the travel speed adjusting pedal 27 and the speed (frequency) in the deceleration state set by depressing the brake pedals 25 and 26 (step S10). , S11).

By performing this matching operation, the brake flag is returned to the reset state (step S12), and thereafter, the operation by the traveling speed adjusting pedal 27 is prioritized.
The vehicle speed is maintained at the speed set by the pedal 27 (step S13). By incorporating the safety mechanism in this way, it is possible to prevent sudden acceleration of the machine body when the brake operation is interrupted and to improve safety.

In this embodiment, the brake pedal 2
The brake device (not shown) is configured to operate when 5 and 26 are stepped on at the same time, and the drive frequency itself of the AC motor 4 is controlled to reduce the vehicle speed.
The machine can be stopped quickly and the phenomenon of image sticking of the brake can be prevented. Also, one-sided blur
The key operation does not produce a deceleration effect, and both brake pedals 25,
Since the vehicle speed is decelerated only when 26 is operated, there is no problem that the vehicle speed is extremely reduced during turning by the one-side brake operation and the workability is deteriorated.

Finally, the flow chart of FIG. 7 relates to PTO control. First, the PTO system rotation speed setting dial 35 is rotated to set the rotation speed of the PTO shaft 15 (step # 1). Then, the actual rotation speed detected by the PTO rotation sensor 46 is compared with the rotation speed set by the dial 35 (step # 2), and the drive frequency is adjusted according to the difference (step # 3). At this time, the AC motor 12 is normally or reversely rotated depending on the deviation and its direction (steps # 4, # 6, #).
7) For example, when increasing the rotation speed of the PTO shaft 15 to keep it at a predetermined value, the forward / reverse unit 51 is switched to the forward rotation side, and the DC / AC converter 54 is provided with a frequency necessary to maintain the rotation. In the case of setting (steps # 6 and # 8) and decelerating in the opposite direction, the forward / reverse unit 51 is switched to the reverse rotation side, and the DC / AC converter 54 is set to a frequency necessary for maintaining a predetermined rotation ( Step # 7, #
8).

[0017]

Since the present invention is constructed as described above, it has the following technical effects. That is, in a tractor having front wheels and rear wheels at the front and rear parts of the machine body, since the traveling system motor and the PTO system motor are independently provided in the vehicle body, load fluctuations occur in the traveling system and motors are generated. Even if slippage occurs in the PTO
The system is not affected by it, and conversely, even if a load change occurs in the PTO system, the running system is not affected at all.

Since all of these motors are AC motors, they are more durable than DC motors because they do not have brushes and can withstand long-term use. In the conventional device, many expensive parts such as a radiator and a muffler are required, and there is a drawback that the manufacturing cost becomes high as a whole. Since there is no equipment, the cost can be reduced significantly. In addition, it has the feature of being comfortable in work with less vibration and noise.

[Brief description of drawings]

FIG. 1 is a side view of a tractor.

FIG. 2 is a plan view of a tractor.

FIG. 3 is a plan view of a main part of a tractor.

FIG. 4 is a control block diagram.

FIG. 5 is a flowchart of the entire control.

FIG. 6 is a control flow chart of a traveling system.

FIG. 7 is a control flow chart of a PTO system.

[Explanation of symbols]

 1 tractor 2 front wheel 3 rear wheel 4 AC motor (running system) 6 lift mechanism 12 AC motor (PTO system) 15 PTO shaft 16 battery 20 control controller

Claims (1)

[Claims] 1. A tractor having front and rear wheels at the front and rear of the machine body, the travel system motor and the PTO system motor being mounted on the machine body, the tractor being provided with a speed change gear. And PTO
The motor drive is characterized in that the speed change of the system is performed by adjusting the rotational speeds of these motors, and a plurality of batteries are arranged around the motor. Type tractor.