JPH02106458A - Speed change device for traveling vehicle - Google Patents

Abstract

PURPOSE:To improve the stability during the traveling on a slope by allowing the car speed to be held within a range from the speed on the start of the speed change operation to zero by controlling the brake operation which acts so as to stop a vehicle, when the car speed during the speed change increases over the car speed before speed change or the traveling direction is reversed. CONSTITUTION:In a power transmission system for a tractor, the turning moment of an engine 1 is transmitted to a driven side through a clutch 2, and said power is decelerated by the main and sub transmission devices 4 and 5, and drives the driving wheels 6 and 6. The clutch 2 is operated by a clutch pedal 10 or cylinder C5, and also a brake device 7 is operated by a brake pedal 11 or the right and left brake operating cylinders C6 and C7. In this case, in a control box 19, for example, when speed change is carried out on a descent slope, etc. and the car speed is accelerated because of the turning off of the clutch 2 or when the vehicle tends to travel backward on an ascent slope, etc., control is carried out so that the brake device 7 is operated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an automatic transmission device provided in a traveling vehicle such as a tractor.

[Prior Art] Electronically controlled transmission devices are used in traveling vehicles such as tractors, which automatically perform clutch on/off operations and gear change operations when a gear shift is set using a setting device. .

[Problems to be Solved by the Invention] The above-mentioned transmission device is very convenient because it can reduce the burden on the operator when changing gears, but the conventional one is difficult to change gears when changing gears on slopes or other slopes. It required attention.

That is, when going downhill, disengaging the clutch may increase the speed, and when going uphill, disengaging the clutch may cause the vehicle to travel in reverse, so the operator had to use the brakes to control the vehicle speed while driving. however.

Since it is not necessary to operate the brakes when shifting gears on a normal level ground, it is easy to cause an accident due to carelessness caused by neglecting to operate the brakes when shifting gears on a slope.

[Means for Solving the Problems] In order to solve the above problems, the present invention has the following configuration.

That is, the transmission device according to the present invention is a transmission device for a traveling vehicle that automatically performs clutch engagement/disengagement operations and gear change operations, and whether the vehicle speed during the shift operation is faster than the vehicle speed before shifting. .

Alternatively, the vehicle is characterized by being provided with a control device that operates a brake device that acts to stop the vehicle when the traveling direction is reversed.

[Effect] The vehicle speed during gear shifting operation becomes faster than the vehicle speed before shifting,
When the direction of travel is reversed, the brake is activated to stop the vehicle, so the vehicle speed is always maintained within the range from the speed at the start of the gear change operation to zero.

[Embodiment] Fig. 1 is a power transmission system diagram of a tractor according to an embodiment of the present invention, in which the rotational power of an engine 1 is transmitted to the driven side via a clutch 2, and is transmitted to the main, sub-transmission devices 4, 5 to drive the drive wheels 6.6. A brake device 7 is provided on the drive wheel 6.6.

The main and auxiliary transmissions 4 and 5 are each capable of shifting into four stages, and the main transmission 4 uses cylinder CI as a shift conversion means.
, C2 and valves Vl, V2, and the sub-transmission device 3 includes cylinders C3, C4 and valves 3, V4. Stroke sensors S1 to S4 are attached to each cylinder to detect its contraction state. The clutch 2 has an operating fork connected to a clutch pedal 10 and a cylinder C5 whose pressure is controlled by a valve v5, and the clutch can be operated by either the pedal or the cylinder. A stroke sensor S5 is attached to the cylinder C5 to detect its contraction state. The brake device 7 can also be operated by either the brake pedal 11 or the left or right brake operation cylinders C6 and C7. Stroke sensors S6 and S7 are also attached to this brake operation cylinder. Further, rotation speed sensors R1, R2, and R3 are provided on the drive side and driven side of the clutch 2 and on the load side of the auxiliary transmission 5, respectively, for detecting the rotation speed of the shaft. These clutch 2, main and auxiliary transmission devices 4 and 5, and brake device 7 are controlled by a speed change control device 20 within a control box 19.

FIG. 2 is a block diagram of the speed change control device, in which the detection results of each stroke sensor S1 to S7 are input to the CPU 22 via the A/D converter 21, and the detection results of each rotation speed sensor R1 to R3 are directly input to the CPU 22. It has been entered. When a shift is set by the operation switch 24 of the main and auxiliary transmissions, an output is output to solenoid valve 5 to disengage clutch 2, and an output is output to solenoid valves v1 to v4 to change gears to achieve the set shift. When the gear change is completed, clutch 2 is engaged. During automatic control, press the clutch pedal lO and press the clutch operation switch 25.
When input, the command from the pedal side takes priority and automatic control is stopped.

Further, the valve V8. Output to V7, brake operation cylinder C
6, C7 allows a brake to be applied to the drive wheel 6.6. Figure 3 is the flowchart.
The brakes will be applied when the vehicle speed during the gear shift operation reaches or exceeds the speed at the start of the gear shift operation, or when the vehicle stops.For example, when shifting gears on a downhill slope, etc., if the vehicle speed is about to increase by disengaging clutch 2. This is regulated, and if a vehicle is about to go the wrong way on an uphill slope, it will be stopped.

The brake operating force gradually weakens as clutch 2 is engaged, and stops when the clutch is fully engaged, so sudden braking is not applied on gentle slopes, and the vehicle runs smoothly. .

Incidentally, data indicating the states of the clutch 2, the main and sub-transmission devices 4.5, and the brake device 7 are also sent to the engine control unit 28.

[Effects of the Invention] As is clear from the above description, the transmission system for a traveling vehicle according to the present invention automatically performs brake control during gear shifting, so even when shifting on a slope, etc., the vehicle speed is reduced. The car no longer speeds up or runs in reverse, allowing safe and smooth driving.

[Brief explanation of the drawing]

FIG. 1 is a power transmission system diagram of a tractor as an example of the present invention, FIG. 2 is a block diagram of a speed change control device, and FIG. 3 is a flowchart showing its control. DESCRIPTION OF SYMBOLS 1... Engine, 2... Clutch, 4... Main transmission, 5... Sub-transmission, 6... Driving wheel, 7...
- Brake device, 20...speed change control device.

Claims (1)

[Claims] (1) A transmission device for a running vehicle that automatically engages/disengages a clutch and changes gears, and the vehicle speed during the shift operation is faster than the vehicle speed before shifting, or the direction of travel is in the opposite direction. The transmission is characterized in that it is provided with a control device that operates a brake device that acts to stop the vehicle.