JPH01172030A - Transmission controller for tractor - Google Patents

Abstract

PURPOSE:To enable speedy and simple operation by constructing the controller in the caption in such a way that a forward speed setter and backward speed setter are independently provided capable of freely operating and a transmitted running is accomplished by a command speed at a switched and selected side by means of a forward/backward lever. CONSTITUTION:A forward/backward lever 7 capable of freely rotational operation in a longitudinal direction is provided at one side of the operation seat 2 of a tractor and the vehicle body is moved forward/backward according to the operating position of the lever. A forward speed setter 19 and backward speed setter 20 are independently provided movably along the long hole of an operating panel in a longitudinal direction, at the side of the forward/ backward lever 7 and the speed changing position of a transmission is selected by each setter 19, 20 to indicate a working speed, a running speed and the like. Namely, based on a speed change command indicated by each setter 19, 20, the main and sub speed change clutches of a transmission are engaged with/disengaged from to change speed according to a flow system set in a program. The indicated forward speed and backward speed are digital-displayed on a speed indicator provided on the operating panel.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a speed change control device for a tractor.

BACKGROUND ART AND PROBLEMS TO BE SOLVED BY THE INVENTION Agricultural tractors are used for work in a field with a working device attached to them, so it is desirable for the vehicle speed to be variable in multiple stages. However, with multi-speed shifting using a main shift and a sub-shift, the shift operation is complicated, and when traveling at working speed in the field, the forward and reverse vehicle speeds must be repeatedly adjusted depending on the conditions of the field. The vehicle is driven a lot and there are many erroneous operations.

Means for Solving the Problems This invention provides an independent forward speed setting device (one forward speed setting device for specifying the forward speed of the vehicle body (1) and automatically changing the speed) and a reverse speed setting device (one) for specifying the reverse speed of the vehicle body (1) and automatically changing the speed. The tractor speed change control device is configured such that the tractor is operable to drive the vehicle at a designated vehicle speed selected by a forward/reverse lever (7) for switching between forward and reverse.

Functions and Effects of the Invention The forward speed setting device (19) selects and specifies a target vehicle speed such as a working speed. In addition, when reversing the vehicle repeatedly, the reverse speed setter 12G selects and specifies a reverse vehicle speed suitable for the task. After specifying each forward speed and reverse speed, the vehicle starts by switching the forward/reverse lever (7). Move the forward/backward lever (7) from the neutral position (N) to the forward position (
When the vehicle is operated to F), the control device automatically changes the speed to the designated forward speed and the vehicle travels forward. Further, when the forward/reverse lever (7) is returned to the neutral position (N) and then operated to the reverse position (R), the speed is automatically changed to the designated reverse speed and the vehicle travels backward.

In this way, if the desired forward speed is specified as the reverse speed using each of the forward and reverse speed setters (19) C70, shifting and forward/reverse movement will be automatically performed by simply switching the forward/reverse lever (7). This makes operation significantly faster and easier. Also, when the gear shifting conditions change, each setting device (! or +
Since all you have to do is change the designation of 21, you will no longer have to force yourself to start or drive.

Embodiment In addition, when the tractor body (1) is rotated, the driver's seat (
2) Steering Il' to steer the front wheels 03 forward
D.

There is an engine (G) etc. that transmits power to the rear axle 0e, and the floor part has a brake pedal (3), a clutch pedal (4),
Steering 04J with accelerator pedal (5) etc.
A throttle lever (6) is provided on the side of the.

On the - side of the cockpit (2), there is a forward/backward lever (7) that rotates in the front/rear direction, and this forward/backward lever (7) is operated from the neutral position (N) to the forward forward position (F). Then, the vehicle body (1) moves forward, and when operated from the neutral position (N) to the reverse position (R), the vehicle body (1) moves backward. There is a switch cam flE on the rotation shaft of the forward/backward lever (7), including a neutral switch (13), a forward switch (141),
and the reverse switch (this is the neutral position (N), forward position (F), and reverse position (R) of this forward/reverse lever (7))
Detect.

The forward/reverse lever (7) is provided with a lever case (1)) that rotates in the same direction as this lever, and these forward/reverse levers (7)
7) and the lever case (1)), a front operation switch (9) and a rear operation switch (1ω) are provided with a free movement gap in the front and back direction, and the pin of this lever case (1)) is provided. , an arm (1η
The control rod (L) connected to By controlling and positioning, the rotation operation of the forward/reverse lever (7) toward the reverse position (R) side or the forward position (F) side is restricted. By rotating the forward/backward lever (7) in the opposite direction, the front operation switch (9) or the rear operation switch (
10 is turned on, the steering brake gloss 01 is controlled and interlocked to brake.

On the side of the forward/reverse lever (7), there is a forward speed setting device (191) and a reverse speed setting device f along the long hole in the longitudinal direction of the operation panel.
f1Q is provided movably, and each of these setting devices 091 G!
According to I), the shift position of the transmission device is selected and the working speed, traveling speed, etc. are specified.

Further, on the minus side of the cockpit (2), an operation panel is provided with a position lever (to), a work mode switch (a), a vehicle speed indicator cap, etc. Of these, the position lever (
(to) specifies and controls the vertical position of the lift arm at the rear of the tractor body (1). The work mode switch (g) switches the control form of the work machine depending on the type of work machine connected to the vehicle body (1). The vehicle speed indicator 01) digitally displays the forward speed and reverse speed separately when specified by the forward speed setting device (19) and the reverse speed setting device (19).

The transmission device between the engine HQ, the rear axle 09, the power take-off shaft, etc. is interlocked with the clutch pedal (4) via the shifter (21) between the crankshaft of the engine 0[9 and the input shaft. A main clutch (2i5 is provided, and the forward/reverse lever (7) is used to operate the neutral switch (1■) and the forward switch (
141, and a reverse switch (a forward/reverse clutch 2+1 that is turned on and off by turning one ON/OFF), a main transmission clutch (2 gear clutches (21), an auxiliary transmission clutch (C) 00, etc.), and The axle of the rear axle H'9 is a transmission configuration. 00 is a vehicle speed sensor that detects the rotation speed or vehicle speed of the transmission system that transmits the rear axle (49), and the left and right steering brakes 03 are a differential transmission device. It is located in the middle of the transmission system that transmits power to the rear axles 09 and is configured to brake the rotation of each rear axle 09. (B) is a power take-off clutch that turns on and off the transmission of the power take-off device to the work machine. be.

In the hydraulic circuit, a hydraulic cylinder +241 is provided which is operated by a pressure control valve Q9 that controls the pressure in the solenoid valve, and the main clutch (2δ) can also be operated on and off electromagnetically.The power take-off clutch (b) is It is turned on and off by a pressure control valve (to) using a solenoid valve.

Main shift clutch (υ stain, and sub shift clutch C291
C3ω, etc. are each provided with a shift control valve I2e using a solenoid valve, and can be controlled by operating a shift control valve QO designated by a forward speed setter (one) or a reverse speed setter (21). .4 main gears (Ml to M4) in rotation
and four sub-shifts (Sl-S4), allowing for forward and reverse gear changes in a combination of 16 stages.

In addition, the steering brake gloss 03 is connected to each left and right hydraulic cylinder (
(b)), and is configured to brake either the left or right steering brake (to) or 03 by switching with the hydraulic switching valve 09, which is a solenoid valve, and this hydraulic switching valve C3"l is set to the neutral position. The pressure control valve e3G, which electromagnetically controls the pressure, allows both left and right steering brakes (to) and zero
3 and 3 simultaneously.

A control unit (CPU) with a microcomputer is
Forward speed setter (19) or reverse speed setter C! O changeover switch, forward/backward operation switch (91 (Iω, neutral switch (13), forward switch (1 turn reverse switch (
19. Brake pedal switch 62), which is turned on when braking by pressing 3) on the brake pedal, and vehicle speed sensor 01)
In response to inputs from the main clutch (pressure control valve G!9 of 2), pressure control valve (to) of the power take-off clutch (equipment), etc.
Each speed control valve (2e to 0 [I), steering brake (to) C
It is configured to control the hydraulic switching valve 09, pressure control valve OQ, and control motor (10, etc.) of 31.

Shift operation is performed by shifting the main shift clutch (271) according to a programmed flow based on a shift command specified by the forward speed setting device (19) or the reverse speed setting device (21).
C1 and auxiliary transmission clutch (29+C1■ are turned on and off,
The gear will be changed. Among these gears, the low speed range of the forward position (F) is set as the working speed (a), and the high speed range is set as the running speed (b). When starting, if the forward speed setting device (19) is specified in this working speed (A) range, the forward/reverse lever (
7) is operated from the neutral position (N) to the forward position (F), the transmission starts at the specified working speed (A). However, when driving on the road, etc., when starting with the forward speed setting device (19) set to the travel speed (B) range, the gear shifting operation is performed at the starting position (C) in the constant working speed (A) range. Then, start in the deceleration state at this starting position (c),
A start control device is provided so that when the vehicle has traveled for a certain period of time or distance, the vehicle is automatically shifted to a travel position (d) in a specified travel speed range (a) and then travels.

In automatic gear shifting by such a control device (CPU), the main gear clutch (υshi1 or Sub-shift clutch (291C3G)
etc., to switch the meshing transmission path of the transmission gear, and after this switching, the main clutch (2) is turned on again.

If you step on the brake pedal (3) to stop suddenly and then take your foot off the brake pedal (3), it will be unsafe to start automatically, so if you step on the brake pedal (3) and the vehicle speed is low enough, , the main clutch (2δ) is disengaged, and the forward/reverse lever (7) is controlled to return to the neutral position (N) when the speed becomes lower.In other words, the pair of left and right brake pedals (3) are simultaneously activated while driving. When stepped on, the brake pedal switch IZ is turned ON, and the steering brake (B) is braked by the pressure control valve OO, reducing the vehicle speed.

This condition is detected by the vehicle speed sensor 0υ, and when the engine brake is below the limit, the main clutch (2♂ is disconnected), and when the vehicle speed decreases further and approaches a stop, the output is sent to the control motor (163) and the forward/reverse lever (7) is activated. is returned to the neutral position (N). In this state, it will not restart even if you take your foot off the brake pedal (3). Note that when only the main clutch (2) is disengaged, the brake pedal (3) ), the pressure is gradually increased by the pressure control valve 12Sj, and the main clutch (2δ) is gently engaged.

Additionally, if the forward speed setting device (19) is operated to change the vehicle speed designation while driving, the main clutch (2δ) is turned off and the main transmission clutch (υC!υ or auxiliary transmission clutch C!90ω is switched and controlled according to the vehicle speed designation. Then, turn on the main clutch (2δ) again. Also, when the forward/reverse lever (7) is set to the reverse position (R), the main clutch (221) is disengaged and the main clutch (27) (21, or sub-shift clutch G!91 +3
[[1 is switched and controlled according to the reverse speed specified by the reverse speed setter (21), and is driven backward by the engagement of the main clutch (2a).

If you attempt to switch the forward/reverse lever (7) from the forward position (F) beyond the neutral position to the reverse position (R), or in the opposite direction, the control motor (10)
An operating position regulating device is provided in which the control rod (l [1) is controlled by the control motor (1
When the arm (1η) by 61 is in the neutral position, the forward/reverse lever (7) can be operated to either the forward/reverse position (F) (R), but the forward/reverse lever (7) is in the forward position (F). When the forward switch (141) is turned ON, the arm (1η) is rotated forward by the control motor (16), and the forward/reverse lever (7) is connected to the pin of the lever case (1) and the control rod (1). [Due to the relationship with the long hole 3, it is locked when returned to the neutral position (N), and then moved to the reverse position (R).
It cannot be rotated (Figure 7). Conversely, when the forward/reverse lever (7) is in the reverse position (R), it cannot be operated beyond the neutral position (N) to the forward position (F) (Fig. 8). During such forward or reverse travel, the forward or reverse travel is decelerated or braked 021
Once stopped by t33 etc., the vehicle speed sensor 0υ detects this stop, and the arm (1η) by the control motor (10) is rotated in the same direction as this forward/reverse lever (7). (7) Neutral position (N)
It becomes possible to operate beyond the limit. When the work equipment is lowered and in the working position, this signal input prevents the control motor (16) from moving beyond the neutral position (N) to the reverse position (R) (Fig. 7). It's good to control. This makes it impossible to move backwards in the working position.

As mentioned above, the forward/reverse lever (7) cannot be operated from the forward position (F) or reverse position (R) to the opposite side beyond the neutral position (N).
) from the neutral position (N) in a direction beyond this neutral position (N), the front and rear operation switches (9) and (10) between the lever case (1)) are turned on. Then, the brake 021 (33) is braked and the vehicle stops traveling, and the vehicle speed sensor 0υ detects this, and the control rod (I
Release the position restriction of 8. In addition, by releasing the position restriction of the forward/reverse lever (7), it is possible to operate beyond the neutral position (N), and since the control is performed by the control motor (16), the forward/rear operating switch (9) , (10) is ○
FF, and the braking of the brake (support) 03 is also released.

[Brief explanation of the drawing]

The figures show an embodiment of the present invention, in which Fig. 1 is a partial perspective view, Fig. 2 is a graph showing the gear ratio, Fig. 3 is a plan view, Fig. 4 is a side view, and Fig. 5 is a side view. Figure 6 is a partial side view, Figure 7 is a partial side view, Figure 8 is a functional side view showing its function, Figure 9 is a transmission mechanism diagram, Figure 10 is a hydraulic circuit diagram,
Figure 1) is a block circuit diagram, and Figure 12 is a partial plan view. In the figure, code (7) is the forward/reverse lever, (91 is the front operation switch, +lff1 is the rear operation switch, (1cO is the forward speed setting device, SI1 is the reverse speed setting device, KO is the pressure control valve, and Qe is the gear shift Control valve, (27) (21 is main transmission clutch, G!!
1) 00 is the sub-shift clutch, OD is the vehicle speed sensor, (a)
03 indicates a steering brake, and (CPU) indicates a control device.

Claims (1)

[Claims] A forward speed setting device (19) for specifying the forward vehicle speed of the vehicle body (1) to automatically change gears and a reverse speed setting device (20) for automatically changing the speed by specifying the reverse vehicle speed of the vehicle body (1) are provided independently and freely operable. A transmission control device for a tractor, characterized in that the vehicle travels under transmission at a designated vehicle speed selected by a forward/reverse lever (7) that switches between the two modes.