JP2003172379A - Tractor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tractor capable of operating both of a traveling brake 22 and a main clutch 18 by operating a single brake pedal 9, easily performing a half-clutch state, capable of surely stopping a machine body by disconnecting the main clutch 18 only by operating the brake pedal 9 without operating a main clutch pedal 10 simultaneously, and capable of improving operability. <P>SOLUTION: This tractor having a hydraulic clutch as the main clutch 18 of a traveling and driving system 17 is provided with a brake force sensor 27 for detecting operation force of the traveling brake 22, and controls operation pressure of the main clutch 18 based on the operation force of the traveling brake 22. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tractor using a hydraulic clutch as a main clutch for connecting and disconnecting an output from an engine.

[0002]

Conventionally, the clutch pedal and the brake pedal are separately installed, and when the machine is stopped while the vehicle is running, there is an operational inconvenience that the brake pedal is operated and the clutch pedal is operated at the same time. .

[0003]

SUMMARY OF THE INVENTION However, according to the present invention, in a tractor using a hydraulic clutch as a main clutch of a traveling drive system, a braking force sensor for detecting the operating force of the traveling brake is provided to detect the operating force of the traveling brake. Based on this, the operating pressure of the main clutch is controlled to operate both the traveling brake and the main clutch by operating a single brake pedal, making it possible to easily achieve a half-clutch state and operating the main clutch pedal at the same time. Without using the brake pedal, the vehicle can be stopped reliably by disengaging the main clutch, and the structure can be simplified and the operability can be improved.

Further, the operating pressure of the main clutch is controlled on the basis of the operating force of the traveling brake and the vehicle speed, and at the time of the braking operation of the brake pedal, the operating oil pressure corresponding to the vehicle speed during the work is supplied to the main clutch. The clutch is operated with an appropriate hydraulic pressure according to the vehicle speed to improve stability.

Further, when the traveling brake is suddenly braked, the main clutch is automatically turned off. For example, when the aircraft is suddenly stopped, the main clutch is immediately turned off to protect the main clutch and work in an emergency. It improves the reliability of.

Further, the operating pressure of the main clutch can be controlled only when the left and right traveling brakes are integrally connected, and the control of the main clutch in the one-brake state in which only one of the left and right traveling brakes is operated is prevented, so that the vehicle turns. It is intended to improve workability when working.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a side view of the whole, and FIG. 2 is a plan view of the same. In the figure, 1 is a tractor, and left and right front wheels 4 and 4 are installed on both sides of a hood 3 in which an engine 2 is installed.
A round steering handle 5 is provided at the rear of the bonnet 3, a driver's seat 6 is installed behind the handle 5, and left and right rear wheels 7 and 7 are provided outside both sides of the driver's seat 6. The left and right brake pedals 9 and 9 and the main clutch pedal 10 are arranged in step 8 so that an operator can sit on the driver's seat 6 to move the vehicle, and at the rear of the tractor body, the three-point link mechanism 1
The cultivating rotary working machine 12 is installed so as to be able to move up and down through the tractor 1 to perform the cultivating work.

Further, the main traveling speed change lever 13 and the working machine 1
An elevating lever 14 for raising and lowering 2 is disposed on the right side of the driver's seat 6, and a traveling auxiliary shift lever 15 and a PTO shift lever 16 for shifting the output of the working machine 12 are disposed on the left side of the driver's seat 6. There is.

As shown in FIG. 3, the traveling drive system 17 of the tractor 1 has a main clutch 18 for connecting and disconnecting the output of the engine 2.
A main transmission unit 19 and an auxiliary transmission unit 20 that change the power rotational speed from the engine 2 according to the working state, and the left and right rear wheels 7.
7 is provided with a rear differential mechanism 21 that causes a rotation difference (differential) and left and right traveling brakes 22 and 23 that independently brake the left and right rear wheels 7 and 7, respectively, so that the output of the engine 2 can be connected to the left and right freely. It is configured to be transmitted to the rear wheels 7 to run and stop the airframe.

Further, as shown in FIG. 4, the left and right traveling brakes 2
The load cell 27 is provided between the brake rods 26 connecting the brake arm 24 for braking the second and the second brake pedals 23 and the pedal arm 25 of the left and right brake pedals 9. It is configured to detect at 27. Further, a brake connector 28 that integrally connects or disconnects the left and right brake pedals 9 and 9 is provided, and a left and right brake connection sensor 29 that detects the integrated connection of the left and right brake pedals 9 and 9 by the connector 28 is provided to provide the left and right traveling brakes 2.
The sensor 29 is configured to detect the right and left simultaneous braking of 2 and 23.

Further, as shown in FIG. 5, the actual vehicle speed is detected based on the number of revolutions of the electromagnetic hydraulic operation valve 31 for supplying the hydraulic oil from the hydraulic pump 30 to the hydraulic main clutch 18 and the rear wheel 7 axle 32. Vehicle speed sensor 33 and the main shift lever 1
3 and a traveling gear shift position sensor 34 for detecting a high speed, a medium speed, and a low call position, and connecting the load cell 27 and the sensors 29, 33, and 34 to a controller 35 and connecting the controller 35 to the hydraulic operation valve 31. By connecting the outputs, the operating pressure of the main clutch 18 is controlled based on the operating force of the left and right brake pedals 9.

As shown in FIG. 6, when a high speed / medium speed / low speed state of the vehicle speed is detected by either the vehicle speed sensor 33 or the traveling shift position sensor 34 during traveling work, as shown in FIG. , A relationship diagram between the brake pedal force corresponding to high speed / medium speed / low speed states and the clutch operating pressure is selected, and when the left / right brake pedals 9/9 are depressed, based on the pedal force detected at that time by the load cell 27. The target working pressure of the main clutch 18 is selected from the relational diagram, and the working oil of the target working pressure is supplied to the main clutch 18. Such control is performed by integrally connecting the left and right brake pedals 9 and 9. This is done only occasionally to prevent operating pressure control of the main clutch 18 by a single pedal 9 operation.

Further, when the pedal 9 is rapidly controlled, the main clutch 18 is automatically turned off to improve the reliability of the work.

As described above, in the tractor using the hydraulic clutch as the main clutch 18 of the traveling drive system 17, the brake force sensor 27 for detecting the operating force of the traveling brake 22.
Is provided and the operating pressure of the main clutch 18 is controlled based on the operating force of the traveling brake 22, so that the traveling brake 22 and the main clutch 18 can be operated by operating a single brake pedal 9.
It is possible to easily perform a half-clutch state by performing both operations of the above. Also, it is possible to perform a reliable machine stop with the main clutch disengaged by operating the left and right brake pedals 9 without simultaneously operating the main clutch pedal 10. The operating pressure of the main clutch 18 is controlled on the basis of the operating force of the traveling brake 22 and the vehicle speed, so that the braking pedal 19 can be operated according to the vehicle speed during work. Supply the working hydraulic pressure to the main clutch 18,
The stability can be improved by operating the main clutch 18 at an appropriate hydraulic pressure according to the vehicle speed.

Further, by automatically turning off the main clutch 18 during the sudden braking of the traveling brake 22,
For example, when the aircraft suddenly stops, the main clutch 18 is immediately turned off to protect the main clutch 18 to improve the reliability of the work in an emergency and only when the left and right traveling brakes 22 are integrally connected. By making the operating pressure controllable, it is possible to prevent the main clutch 8 from being controlled in a one-brake state in which only one of the left and right traveling brakes 22 is operated, and improve workability during turning work and the like. it can.

[0016]

As is apparent from the above-described embodiments, the present invention is a tractor using a hydraulic clutch as the main clutch 18 of the traveling drive system 17 and is provided with a braking force sensor 27 for detecting the operating force of the traveling brake 22. Traveling brake 2
Since the operating pressure of the main clutch 18 is controlled based on the operating force of 2, the operation of both the traveling brake 22 and the main clutch 18 is performed by operating a single brake pedal 9.
A half-clutch state can be easily achieved, and the main clutch 18 can be disengaged without operating the main clutch pedal 10 at the same time, and the vehicle can be reliably stopped to improve the operability. It is possible.

Further, since the operating pressure of the main clutch 18 is controlled on the basis of the operating force of the traveling brake 22 and the vehicle speed, when the braking operation of the brake pedal 19 is carried out, the operating oil pressure corresponding to the vehicle speed being worked is applied to the main clutch. 18 to supply the main clutch 18 with an appropriate hydraulic pressure according to the vehicle speed to improve stability.

Further, since the main clutch 18 is automatically turned off when the traveling brake 22 is suddenly braked, the main clutch 18 is immediately turned off to protect the main clutch 18 when the airframe is suddenly stopped, for example. The reliability of work in an emergency can be improved.

Further, since the operating pressure of the main clutch 18 can be controlled only when the left and right traveling brakes 22 are integrally connected, the main clutch 8 in the one-brake state in which only one of the left and right traveling brakes 22 is operated. To prevent the control of
It is possible to improve workability in turning work.

[Brief description of drawings]

FIG. 1 is an overall side view of a tractor.

FIG. 2 is an overall plan view of a tractor.

FIG. 3 is an explanatory diagram of a traveling drive system.

FIG. 4 is an explanatory diagram of a brake pedal section.

FIG. 5 is a control circuit diagram of a main clutch.

FIG. 6 is a flowchart.

FIG. 7 is a relationship diagram of a brake pedal force and a clutch operating pressure.

[Explanation of symbols]

17 Travel drive system 18 main clutch 22 Running brake 27 load cell

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Claims (4)

[Claims] 1. In a tractor using a hydraulic clutch as a main clutch of a traveling drive system, a brake force sensor for detecting an operating force of a traveling brake is provided, and an operating pressure of the main clutch is controlled based on the operating force of the traveling brake. A tractor characterized by being provided as described above. 2. The tractor according to claim 1, wherein the tractor is provided so as to control the operating pressure of the main clutch based on the operating force of the traveling brake and the vehicle speed. 3. The tractor according to claim 1, wherein the main clutch is automatically turned off when the traveling brake is suddenly braked. 4. The tractor according to claim 1, wherein the operating pressure of the main clutch can be controlled only when the left and right traveling brakes are integrally connected.