JPH01172031A - Transmission controller for tractor - Google Patents

Abstract

PURPOSE:To make it possible to usually obtain safety steering operation by providing an operating position restricting device, on a forward/backward lever, which allows the switching operation of the lever toward opposite direction beyond a neutral position only in a running speed reduction or after stoppage. CONSTITUTION:A forward/backward lever 7 capable of freely rotating operation in a longitudinal direction is provided at one side of the operator's seat of a tractor and the body is moved according to the operation of the lever. One of forward/backward operating switches 9, 10 provided in a lever case 11 is turned on by the rotating operation of the forward lever 7 so that a control motor 16 is controlled in normal/reverse rotation according to the output signal of each switch 9,10. Accordingly, a control rod 18 is positioned at a forward/ backward position via an arm 17 and the rotating operation of the forward/ backward lever 7 toward a forward position side is restricted by the end of its long hole. A forward speed setter 19 and backward speed setter 20 are independently provided movably along a long hole in the longitudinal direction of an operating panel at the side of the forward/backward lever 7.

Description

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

Problems to be Solved by the Prior Art and the Invention When working on a tractor in a field with a working device attached, the vehicle body often moves forward and backward repeatedly. For this reason, there is a known operation mode in which a single operating lever is switched from a neutral position to a forward forward position on the front side or a reverse position on the rear side. Assuming that it can be operated from the neutral position to the reverse position in one go,
It is dangerous when the traveling axle is rotating due to the inertia of the vehicle body in the neutral position, and damage to the working equipment is likely to occur when the vehicle is in the working position.

Means for Solving the Problems This invention provides a single forward/reverse lever (7) for switching from a neutral position (N) to a forward position (F) or a reverse position (R).
A tractor speed change control device is provided with an operation position regulating device that allows the forward/reverse lever (7) to shift beyond the neutral position (N) in the opposite direction only after the vehicle has decelerated or stopped. composition.

Effects and Effects of the Invention When the vehicle speed position for gear shifting is specified and the forward/reverse lever (7) is placed in the neutral position (N), no running occurs, but the forward/reverse lever (7) is placed in the neutral position (N). ) to the forward position (F), the vehicle will run at the specified forward speed. Furthermore, when the vehicle is operated from the neutral position (N) to the reverse position (R), the vehicle travels at the specified reverse speed. The forward/reverse lever (7) in the forward position (F)
) is returned to the neutral position (N), forward travel will be stopped, but
At this time, if the vehicle speed is above a certain level due to the inertia of the vehicle's forward travel, even if you try to switch the forward/reverse lever (7) to the reverse position (R) on the opposite side, the operation position restriction device will prevent the reverse movement. Operation to position (R) is stopped. At this time, if the vehicle speed stops or decreases below a certain level after operating the forward/reverse lever (7) to the neutral position (N), the forward/reverse lever (7) is moved by the operating position regulating device.
Release the operation restriction to the reverse position (R) side. Therefore, the vehicle can travel at the designated reverse speed by operating the forward/reverse lever (7) to the reverse position (R).

The same applies when switching the forward/reverse lever (7) from the reverse position (R) to the forward position (F).

In this way, when switching the forward/reverse lever (7) from the neutral position (N) to the forward position (F) and the reverse position M (R) to switch between forward and reverse travel, the operation position is restricted. In order for the device to work, when the forward/reverse lever (7) is operated to the neutral position (N), it cannot be switched to the opposite position unless the vehicle speed has stopped or decelerated. There is no sudden change to the direction and the driver is not shaken, and safe driving can be maintained.
Do not strain the power transmission.

Example In addition, in the rotation figures 1 to 12, the tractor body (
1) is a steering wheel 041. which steers the front axle C3 in front of the driver's seat (2). Engine (4) that transmits power to the rear axle C9
0, etc., and the brake pedal (3), clutch pedal (4), accelerator pedal (5), etc. are arranged on the floor.
A throttle lever (6) is provided on the side of the steering wheel.

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 0 on the rotation shaft of this forward/reverse lever (7), a neutral switch (1 yong), a forward switch (sliding door), and a reverse switch (one is the forward/reverse lever (7)). Each neutral position (N), forward position (F), and reverse position (R) are detected.

The forward/reverse lever (7) is provided with a lever case (Ill) that rotates in the same direction as this lever.
7) and the lever case (11), a front-operation switch (9) and a rear-operation switch (1) are provided by forming a free movement gap in the front-rear direction, and the pin of the lever case (11) is An arm (1) rotated by a control motor (Ili)
The control rod connected to η (fits into the long hole of Ill,
By controlling and positioning the control rod flEI by this control motor (IG) to the forward position (Fig. 7) or the reverse position (Fig. 8), the forward/reverse lever (7) is moved to the reverse position (R). It restricts the rotation operation toward the side or the forward position (F) side. The lever case (11) in these regulation positions
), turn the front operation switch (9) or the rear operation switch (1) on by rotating the forward/reverse lever (7) in the direction opposite to Control is linked.

On the side of the forward/reverse lever (7), a forward speed setting device (+91. and a reverse speed setting device 1
2G is provided movably, and each of these setting devices (1910!l
This is a configuration in which the shift position of the transmission device is selected and the working speed, traveling speed, etc. are specified.

Further, on the negative side of the cockpit (2), an operation panel is provided with a position lever (to), a work mode switch 6Q, a vehicle speed indicator cap, etc. Among these, the position lever (a) specifies and controls the vertical position of the lift arm at the rear of the tractor body (1). The work mode switch 61 is connected to the vehicle body (
1) The control form of the work machine is switched depending on the type of work machine connected to the above. The vehicle speed indicator (vehicle speed indicator cap) digitally displays the forward speed and reverse speed when specified by the forward speed setter (one) and the reverse speed setter (21, etc.).

The transmission device between the engine HE+, the rear axle C9, the power take-off shaft, etc.
A main clutch (2) is provided which is interlocked via a forward/reverse lever (C), and a neutral switch (13), a forward switch (13), a forward/reverse clutch (2) which is turned on/off by a reverse switch (on/off) is provided by the force of the forward/reverse lever C. 21), a main speed change clutch (υQl, auxiliary speed change clutch +29) C1ω, etc. are provided, and furthermore, the axles of the left and right rear wheels C9 are transmitted from the differential transmission device. The vehicle speed sensor that detects the rotation speed of the transmission system or the vehicle speed, and the left and right steering brakes ■03 are located in the middle of the transmission system that transmits the transmission between the differential transmission and the rear wheels (G), and are used to detect the rotation of each rear axle f4+19. (2) is a power take-off clutch that turns on/off transmission of the power take-off device to the work machine.

In the hydraulic circuit, a hydraulic cylinder (24J) is provided which is operated by a pressure control valve ff1s that controls the pressure on an electromagnetic valve, and the main clutch (24J) can also be operated on and off electromagnetically.A power take-off clutch ( (b) is turned on and off by pressure control (Iken) using a solenoid valve.

Main transmission clutch [υ(2[I, and sub-transmission clutch 09
The countries, etc. can control the speed change by installing a speed change control valve Ce using a solenoid valve and operating the speed change control valve I2Q specified by the forward speed setting device (19) or the reverse speed setting device +2 [). can. When rotating, there are 4 main gears (Ml to M4)
) and 4 auxiliary gears (31 to 34), resulting in 16 combinations of gears.
The gears can be shifted between forward gear and reverse gear.

The steering brake (b) 03 is operated by each left and right hydraulic cylinder (to), and is operated by either the left or right steering brake (2) or C13 is configured to brake, and by setting this hydraulic switching valve Oe to neutral and controlling the pressure electromagnetically, the pressure control valve OQ is used to control both the left and right steering brakes (equipment).
The configuration is such that brakes and 03 are simultaneously braked.

A control unit (CPU) with a microcomputer is
Forward speed setting device (1ω) or reverse speed setting device EL changeover switch, front/rear operation switch (91fl■, neutral switch (1 Shu), forward switch (141), reverse switch (1st), brake by stepping on the brake pedal (3) The pressure control valve C2 of the main clutch (2, 15) receives input from the brake pedal switch @O which turns on at
5), the pressure control valve (to) of the power take-off clutch, each speed change control valve ee -am, the hydraulic switching valve Oe and pressure control valve OQ of the steering brake gloss 01, and the control motor (formerly) be.

The shift operation is based on a shift command specified by the forward speed setter (19) or the reverse speed setter ffl[).
The main transmission clutch ti according to the programmed flow
(2+3 and auxiliary shift clutch 29) C] [++ is turned off and the gear is shifted. Among these gears, the forward position (
The low speed range of F) is set as the working speed (a), and the high speed range is set as the running speed (b). When starting, this working speed (a)
When the forward speed setting device (1) is specified in the range, operating the forward/reverse lever (7) from the neutral position (N) to the forward position (F) will shift to the specified working speed (A). However, when driving on the road, etc., when starting with the forward speed setting device (1 If you are at the starting position (c) in the specified speed range (c) and start in the deceleration state at this starting position (c) and drive for a certain period of time or distance, it will automatically move to the driving position (ni) in the specified speed range (a). ) is equipped with a start control device so that the vehicle can automatically shift gears and travel.

In automatic gear shifting using such a control unit (CPU),
Through the related operations of the pressure control valve 12511 and the speed change control valve Qe, the main speed change clutch (υQυ, or the auxiliary speed change clutch G!91C3) is
ω, etc. are turned on and off to switch the meshing transmission path of the transmission gear, and after this switching, the main clutch (2a) 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, , turn off the main clutch, and when the speed becomes even lower, move the forward/reverse lever (7) to neutral position 11 (N).
The control is configured to return to . That is, when the pair of left and right brake pedals (3) are simultaneously stepped on while driving, each brake pedal switch 21 is turned on and the pressure control valve r3Q is turned on.
As a result, the steering brake (g) 03 is braked and the vehicle speed is reduced. This condition is detected by the vehicle speed sensor 0υ, and when it becomes below the limit of engine braking, the main clutch (2δ) is disengaged, and when the vehicle speed decreases further and approaches a stop, the output is sent to the control motor (10) and the forward/reverse lever (7) is activated. Pull it back to the neutral position (N). In this state, it will not restart even if you take your foot off the brake pedal (3). Please note that when the main clutch is disengaged, the brake pedal (3) When the foot is released, the pressure is gradually increased by the pressure control valve I251, and the main clutch (2) is gently engaged.

Also, if you change the vehicle speed designation by operating the forward speed setting device (I9) while driving, the main clutch (2δ is turned off and the main transmission clutch (7?) R2116 or the sub-transmission clutch +2!II
The switching of cIω is controlled according to the vehicle speed specification, and the main clutch (2δ) is turned on again. Also, when the forward/reverse lever (7) is placed in the reverse position (R), the main clutch (2) is turned off and the main clutch (2δ is turned on). υshe, or auxiliary transmission clutch C!9)
C3 [1 is switched and controlled according to the reverse speed specified by the reverse speed setter (2Q), and the vehicle is moved backward when the main clutch (2) is engaged.

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 (16)
) is controlled by the control rod (11) to disable the movement of the forward/reverse lever (7) beyond the neutral position (N).
When the arm (1η) by the arm (6) is in the neutral position, the forward/reverse lever (7) can be operated to either the forward/reverse position (F) or (R); ), when the forward switch (141) is turned on, the control motor (I) is rotated forward by the arm (I), and the forward/reverse lever (7) is connected to the pin of the lever case (11) and the control rod. (Due to the relationship with the elongated hole in 1
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 motion is decelerated or braked (b).
Once stopped by C (3 etc.), the vehicle speed sensor Oυ detects this stop and the control motor (IGI
The arm (lη) is rotated in the same direction as this forward/backward lever (7), and the neutral position (N
) Crossover 11= operation becomes possible. Note that when the work equipment is lowered and in the working position, the control motor (1) is controlled by this signal input.
6) may be controlled to a state (FIG. 7) that restricts the operation to the reverse position (R) beyond the neutral position (N). This makes it impossible to move backwards in the working position.

As mentioned above, move the forward/backward lever (7) from the forward position (F) or reverse position (R) to the neutral position fi! (N) Although it cannot be operated to the opposite side, move this forward/backward lever (7) further from the neutral position (N) to this neutral position (N).
When rotated in the direction of crossing the lever case (11)
The front and rear operation switches (9) located between the
The brakes are applied, and the vehicle stops traveling.
The vehicle speed sensor el11 detects this and the control rod (I
Release the position restriction for n. Furthermore, by releasing the restriction on the position of the forward/backward lever (7), it is possible to operate beyond the neutral position (N), and since the control is performed by the control motor (10), the front/rear operating switch (9), flO) is 0F
FL, te, brake (g) O hot water braking is also released.

=12- Figures 13 and 14 show that when the forward/reverse lever (7) is operated to the forward position (F), the vehicle runs at the speed specified by the forward speed setting device (Igl), but when traveling in reverse , a reverse speed ratio setting device c!4 is provided to set the reverse speed so that the vehicle travels at a speed that takes into account the reverse speed ratio with respect to the specified forward speed.For example, the forward speed setting device (+'Jl) is set to ( e) When specifying the position, the backward speed is set to 0 for the corresponding equidistant range, -1, -2 for the deceleration range, and +1, +2 for the speed increase range. to), (g), (ch), (su)
Each position is assigned, and the reverse speed ratio setting device c! The actual speed is determined by the setting of The assignment of reverse speed to forward speed is determined mainly by considering practical operation, and is not based on a fixed concept such as a constant ratio.

[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, Figures 7 and 8 are operational side views showing its function, Figure 9 is a transmission mechanism diagram, Figure 10 is a hydraulic circuit diagram, Figure 10 is a hydraulic circuit diagram, 11 is a block circuit diagram, FIG. 12 is a partial plan view, FIG. 13 is a partial perspective view showing another embodiment, and FIG. 14 is a graph showing the gear ratio thereof. In the figure, symbol (7) is the forward/reverse lever, (9) is the front operation switch, (Iω is the rear operation switch, (1 is the forward speed setting device, r2G is the reverse speed setting device, 8251 is the pressure control valve, and C2 is the forward speed setting device.
[9 is the speed change control valve, (υC!υ is the main speed change clutch, Q (
To) OΦ is the sub-shift clutch, 0υ is the vehicle speed sensor, gloss 03
indicates a steering brake, and (CPU) indicates a control device.

Claims (1)

[Claims] From neutral position (N) to forward position (F) or reverse position (R)
An operation that allows the single forward/reverse lever (7) to switch to the opposite direction beyond the neutral position (N) only after deceleration or stop of travel. A tractor speed control device equipped with a position regulating device.