JPH01172037A - Speed change controlling device of tractor - Google Patents

Abstract

PURPOSE:To always enable smooth start by using such a means that, when a working speed is specified, start is made at this speed and that, when a running speed is specified in a range for greater speed than working speed, start is made at the working speed and thereafter the speed is automatically changed to the specified running speed. CONSTITUTION:A front-to-back turnable advance-reverse lever 7 is provided on one side of the operating seat 2 of a tractor, and a vehicle is advanced or reversed by use of the lever. Also, on the side of the advance-reverse lever 7 and along the longitudinal long hole of an operator panel are independently and displaceably provided an advance speed provider 19 and a reverse speed provider 20. A working speed or running speed is specified by selecting the position of a transmission using these speed providers 19 and 20. When the working speed is specified by the advance speed provider 19 taking, out of each speed change step, a lower speed range of an advancing position as the working speed and a higher speed range as the running speed, transmission and starting are made at the speed change position of the specified working speed. On the other hand, when the running speed is specified, starting is made at the working speed and thereafter speed change is made at the speed change position of the specified running speed.

Description

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

Conventional technology and problems to be solved by the invention Agricultural tractors often need to change their vehicle speed significantly between when they are simply traveling on the road and when they are working in the field with a working device attached. Moreover, it is desirable for the work that these vehicle speeds can be changed in multiple stages. However, with multi-speed shifting using a main gear and a sub-shift, the gear shifting operation is complicated, and moreover, when traveling at working speed in the field, if you accidentally start at the traveling speed when traveling on the road, the work equipment may It is difficult to start the vehicle smoothly, as it causes excessive force and the engine tends to stop.

Means for Solving the Problems This invention specifies a working speed in a vehicle speed range suitable for work, starts at this working speed, and specifies a running speed in a vehicle speed range in which work is not performed at a speed higher than this working speed. Accordingly, a tractor speed change control device is provided with a start control device that automatically changes speed to a specified running speed after starting at a working speed.

Functions and Effects of the Invention When the operator specifies a working speed, the transmission automatically changes the working speed within a vehicle speed range suitable for this work, and the vehicle starts at this working speed and performs the predetermined work. Can be done. When you specify a running speed and start, the vehicle speed is automatically reduced to within the vehicle speed range of the working speed, and then the vehicle starts at this working speed and then is automatically increased to the specified running speed. Therefore, not only when the operator starts by specifying a working speed at the time of starting, but also by specifying a traveling speed, the vehicle starts from the working speed at the deceleration position, so smooth running can be achieved.

Example In addition, in the rotation figures 1 to 12, the tractor body (
1) is a steering wheel (441) that steers the front wheels 03 in front of the driver's seat (2), and an engine C that drives the rear axle C9.
A brake pedal (3), a clutch pedal (4), an accelerator pedal (5), etc. are arranged on the floor.
A throttle lever (6) is provided on the side of the steering wheel H.

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 (IZ) on the rotation shaft of this forward/reverse lever (7), and includes a neutral switch (13+), a forward switch (i41.
and reverse switch (one is for each neutral position (N), forward position (F), and reverse position (R) of this forward/reverse lever (7).
) is detected.

The forward and backward movement levers (7) are provided with a lever case (11) 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 (1ω) are provided, and a front-operation switch (9) and a rear-operation switch (1ω) are provided to control the pin of the lever case (11). An arm (Iη) rotated by a motor (16)
The control rod (1G) connected to the control rod (1 By positioning the forward/reverse lever (7) to the reverse position (R) side or the forward position (F) side, the rotation operation of the forward/reverse lever (7) to 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, and the steering brake (G) is controlled and interlocked to brake. There is.

On the side of the forward/reverse lever (7), a forward speed setting device (19) and a reverse speed setting device (
21) are provided movably, and each of these setting devices (1910!
The shift position of the transmission device is selected by l, and the working speed, traveling speed, etc. are specified.

Further, on the negative side of the cockpit (2), a control panel is provided with a position lever (to), a work mode switch [4 (1), and a vehicle speed indicator @I), etc. Among 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) is
The control mode of the working machine is switched depending on the type of working machine connected to the vehicle body (1). The vehicle speed indicator 61) digitally displays the forward speed and reverse speed when specified by the forward speed setter (19) and the reverse speed setter (2Q, etc.).

The transmission device between the engine 0e, the rear axle f4Ill, the power take-off shaft, etc. is connected between the crankshaft of the engine 6Q and the input shaft, and the main clutch is interlocked with the clutch pedal (4) via the clutch pedal (a). (2), a neutral switch (+31), a forward switch (141+, and a reverse switch (forward/reverse clutch G!1 that is turned on and off by ISI ON/OFF) are provided by the forward/reverse lever (7), and the main shift clutch ( 27) (20) An auxiliary transmission clutch 00 is provided, and the axle of the left and right rear wheels HEI is further configured to be transmitted from the differential transmission. 0υ is the rotational speed or vehicle speed of the transmission system that transmits the rear wheel 0. The vehicle speed sensor 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 axle 09, and are configured to brake the rotation of each rear axle 09.0η is This 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 Q4 operated by a pressure control valve (two pressure control valves) is provided in the solenoid valve to control the pressure.
The main clutch (2δ) can also be turned on and off electromagnetically.The power take-off clutch (b) is turned on and off by a pressure control valve (to) that is an electromagnetic valve.

The main speed change clutch (5) I2υ and the auxiliary speed change clutch (c) 0ω are each equipped with a speed change control valve (2G) by a solenoid valve, and a forward speed setter (1g) or a reverse speed setter (21) By operating the control valve (2B), it is possible to control the speed change.
) and 4 auxiliary gears (Sl-S4), 16 combinations of gears
The gears can be shifted between forward gear and reverse gear.

In addition, the steering brake @03 is connected to each left and right hydraulic cylinder (
(b), which is configured so that either the left or right brake is operated by one steering brake (transfer) or 03 by switching with the hydraulic switching valve C3e, which is a solenoid valve, and this hydraulic switching valve 09 is set in the neutral position. The pressure control valve C3Q, which electromagnetically controls the pressure, allows both left and right steering brakes (Company) and 03
It is configured to brake both at the same time.

A control unit (CPU) with a microcomputer is
Step on the changeover switch using the forward speed setter (1ω) or the reverse speed setter 112G, the forward/backward operation switch (9) (10), the neutral switch (13), the forward switch (141), the reverse switch (19), and the brake pedal (3). O when braking with
N brake pedal switch 0 and vehicle speed sensor 0
In response to input from υ, etc., the pressure control valve C9 of the main clutch (2), the pressure control valve 08 of the power take-off clutch (B),
Each transmission control valve ee-am, the hydraulic switching valve C3'l of the steering brake C@01, the pressure control valve OQ, and the control motor (
This configuration controls Ili and the like.

The shift operation is based on the shift command specified by the forward speed setting device (19) or the reverse speed setting device (19), and the main speed change clutch (5) Ql and the auxiliary speed change clutch +29) C1 mountain are shifted according to the flow set by the program. The person is cut and the gear is 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, when the forward speed setting device (Igl) is specified in this working speed (A) range, operating the forward/reverse lever (7) from the neutral position (N) to the forward position (F) will cause the specified speed to change. The transmission starts at the working speed (A) shift position.However, when driving on the road, etc., the forward speed setting device (19
) is specified as the driving speed (B) range, when starting the vehicle,
The gear shifting operation is performed at the starting position (c) in a certain working speed range (a), and when the vehicle starts at this starting position (c) in a decelerated state and travels for a certain period of time or distance, it automatically shifts to the specified driving position. A start control device is provided so that the vehicle is automatically shifted to the traveling position (d) in the speed range (a) and is driven.

In automatic gear shifting using such a control unit (CPU),
Pressure control valve +2Sl and speed control valve c! Due to the related operation by
] ω etc. are turned on and off to switch the engagement 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 When the main clutch (2) is disengaged and the speed becomes even lower, the control structure is such that the forward/reverse lever (7) is returned to the neutral position (N).In other words, the pair of left and right brake pedals (3) are activated while driving. When pressed at the same time, the brake pedal switch (reverse) turns ON and the pressure control valve CJl1
9, the steering brake C@03 is braked and the vehicle speed is reduced. This condition is detected by the vehicle speed sensor 0υ, and when the engine brake is below the limit, the main clutch (23) is disengaged, and when the vehicle speed decreases further and approaches a stop, the control motor (16)
output to return the forward/reverse lever (7) to the neutral position (N). In this state, even if you take your foot off the placket petal (3), it will not start again. In addition, the main clutch (2i
When only 5 is in the off position and you take your foot off the brake pedal (3), the pressure is gradually increased by the pressure control valve +2Sl and the main clutch (2δ is gently engaged).

Also, if you change the vehicle speed specification by operating the forward speed setting device (1) while driving, the main clutch (2) will be disconnected and the main transmission clutch (2) will be disconnected.
Switching of the transmission clutch or the auxiliary transmission clutch CIω is controlled according to the vehicle speed designation, and the main clutch Qa is turned on again.

Also, when the forward/reverse lever (7) is set to the reverse position (R), the main clutch (2δ) is disengaged and the main transmission clutch (υ (to)
, or the auxiliary transmission clutch Q9) 0ω is connected to the reverse speed setting device (2
Switching is controlled according to the reverse speed specified by No. 1, and the vehicle is driven backward when the main clutch (2a) 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)
An operating position regulating device is provided in which the control rod (In) by the control motor (1) is controlled and disables movement of the forward/reverse lever (7) beyond the neutral position (N).
When the arm (i) by 61 is in the neutral position, the forward/reverse lever (7) can be operated to either the forward/reverse position (F) or (R); ), the arm (1η) is rotated forward by the control motor (16) when the forward switch 04 is turned on, and the forward/reverse lever (7) is connected to the pin of the lever case (11) and the control rod (18). Due to its relationship with the elongated hole, it is locked when returned to the neutral position (N) and cannot be rotated further to the reverse position (R) (Fig. 7). Also, conversely, the forward/reverse lever (7) Similarly, when the is in the reverse position (R), it cannot be operated beyond the neutral position (N) to the forward position (F) (Fig. 8). Or, once the reverse movement is stopped due to deceleration or braking, etc., the vehicle speed sensor 0υ detects this stop and the control motor (former arm (I)
The force is rotated in the same direction as the forward/reverse lever (7), allowing the forward/reverse lever (7) to be operated beyond the neutral position (N). 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) located between the lever case (11) are turned on. , the brake (g) 03 is braked and the vehicle stops traveling,
The vehicle speed sensor 0D detects this and releases the position restriction of the control rod (18). Also, by releasing the position restriction of the forward/reverse lever (7), operation beyond the neutral position (N) is possible, and Since the control is performed by the control motor (I6), the front and rear operation switches (9) and (10) are turned OFF.
Then, the brake Li-key@c13(1) is also released.

Figures 13 and 14 show that when the forward/reverse lever (7) is operated to the forward position (F), the vehicle travels at the speed specified by the forward speed setter (1); A reverse speed ratio setter rzti is provided to set the reverse speed so that the vehicle travels at a speed that takes the reverse speed ratio into consideration with respect to the designated forward speed.For example, the forward speed setter (1g) is designated to the (E) position. Then, for the backward speed, the corresponding equidistant range is O, the deceleration range is -1, -2, and the speed increase range is +1.+2. g), (ch), (su)
The actual speed is determined by the setting of the reverse speed ratio setter rz6. 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.

Further, FIGS. 15 and 16 show a configuration in which the vehicle speed is set only in the forward position (F) using the forward speed setting device (1 (2)).

[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, Fig. 11 is a block circuit diagram, Fig. 12 is a partial plan view, Fig. 13 is a partial slope view showing another embodiment, Fig. 14 is a graph showing its gear ratio, and Fig. 15 is another embodiment. FIG. 16 is a graph showing the gear ratio. In the figure, code (7) is the forward/reverse lever, (9) is the front operation switch, (lω is the rear operation switch, (1 mark is the forward speed setting device, (2 [1 is the reverse speed setting device, and Q9 is the pressure control Valve, (2[
9 is a speed change control valve, 17f/I C! l is the main transmission clutch, G! 'IIOω indicates the auxiliary transmission clutch, OD indicates the vehicle speed sensor, gloss 03 indicates the steering brake, and (CPU) indicates the control device.

Claims (1)

[Claims] By specifying a work speed in a vehicle speed range suitable for the work, the vehicle will start at this work speed, and by specifying a travel speed in a vehicle speed range where work is not performed at a higher speed than this work speed, the vehicle will start at the work speed and then run at the specified work speed. A tractor speed change control device that is equipped with a start control device that automatically changes speed.