JPH01193449A - agricultural tractor - Google Patents

Abstract

PURPOSE:To achieve the enhancement in operability by making a speed change operation to be carried out on the basis of a stored value prior to the signal of a vehicle speed setting mechanism when the switch for lifting a ground working device to a prescribed level is turned ON, and by making it to be carried out to a set vehicle speed when the switch is turned OFF. CONSTITUTION:When a switch 27 is turned ON, a ground working device 9 is lifted up to a prescribed level by a forced lifting means D, and at the same time a speed change device A is operated by a priority controlling means C to the speed change stage previously stored in a storing means M prior to the speed change stage having been input by a vehicle speed setting mechanism 29 via a control means 8. Next, when the switch 27 is turned OFF, the ground working device 9 is lowered to the initial level, and the vehicle speed is restored to the speed having been set by the vehicle speed setting mechanism 29. Thus, the enhancement in the operability of a farm tractor can be achieved.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention raises the ground working device to a predetermined level relative to the vehicle body by turning on the switch, and raises the ground working device by turning the switch OFF. This invention relates to an agricultural tractor equipped with forced raising means for lowering it to a previous level.

[Conventional technology]

Conventionally, as an agricultural tractor configured as described above, there is one shown, for example, in Japanese Utility Model Application No. 61-178809, and in this reference, priority is given to control of raising and lowering the ground working device with respect to the vehicle body. A control system is configured that is capable of raising the ground work equipment.

[Problem to be solved by the invention]

Also, when considering plowing work using rotary tillage equipment, etc., in this plowing work, the running speed of the vehicle body relative to the field is determined depending on the type of work, and when the vehicle body reaches the headland and makes a turn, At the same time, the vehicle speed is reduced while raising the working equipment. Also, when the vehicle body reaches the headland, such as in circular plowing work, if the vehicle body needs to be driven on the headland, the vehicle body will be lowered to the headland. Each time it reaches the target, it is necessary to raise the working equipment and at the same time increase the vehicle speed.

In addition, in order to eliminate the trouble of raising the ground work equipment and changing the vehicle speed while operating the steering wheel when the vehicle body reaches the headland, as in the above-mentioned reference, a one-touch switch is installed. A control system has been developed that allows the ground work equipment to be raised and restored to its original level by operation, but when changing vehicle speed, one of the many gears must be selected. The operation remains troublesome and there is room for improvement.

An object of the present invention is to rationally configure a control structure capable of raising a ground working device and obtaining a desired vehicle speed in an unforeseen case, such as when the vehicle body reaches a headland.

[Means to solve the problem]

The features of the present invention include a transmission operated by electrical control, a vehicle speed setting mechanism that selects the traveling speed of the vehicle body through manual operation, and a transmission that changes gears based on a signal from the vehicle speed setting mechanism. and a storage means for storing a preselected traveling speed of the vehicle body; and a speed change based on a value stored in the storage means, giving priority to a signal from the vehicle speed setting mechanism when the switch is turned on. and a priority control means for performing a gear shifting operation based on a signal from the vehicle speed setting mechanism (to restore the vehicle speed by turning off the switch). , and the effects are as follows.

[For production]

When the above characteristics are configured as shown in FIGS. 1 and 2, for example, when the switch (27) is turned on, the headland working device (9) is raised by the forced lifting means (C). At the same time, the priority control means (C) gives priority to the gear position input from the vehicle speed setting mechanism (29).
The transmission (A) is operated to the gear stage stored in advance in the storage means, and when the switch (27) is turned off, the ground work device (9) is lowered to the original level and the vehicle speed is lowered. The speed will be restored to the speed set by the vehicle speed setting mechanism (29).

In other words, the lifting and lowering of the ground work device (9) and the vehicle speed can be controlled by operating one switch (27).
This simplifies the operation for raising and lowering the ground work device, and at the same time simplifies the operation for selecting one of the many gears.

This operation is expressed as in the flowchart in Figure 2,
The forced raising means (D) consists of steps #9, the priority control means (C) consists of steps #10 and #11, and the control means (B) consists of steps #16 to #21.

〔Effect of the invention〕

Therefore, even when many operations are required in a short period of time, such as when the vehicle reaches a headland, the ground work equipment can be raised and lowered at the same time as desired with the extremely simple operation of a single switch. The result is an agricultural tractor with excellent operability that can achieve vehicle speeds of

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

Figure 8 shows the body of an agricultural tractor in working condition.This agricultural tractor is made up of an engine (1), a main clutch housing (2), and a transmission case (3) connected in sequence. Wheels (4) and (5) are arranged, and a lift cylinder (6) is installed at the top of the transmission case (3).
A pair of left and right lift arms (7) are provided which are raised and lowered by the operation of the lift arm (7). A rotary tiller (9) is connected thereto.

Further, a driver's seat (10) is provided above the transmission case (3), and on the upper surface of a rear fender (11) on the right side of the driver's seat (10), there is a lifting/lowering device such as the rotary tiller (9). Control box (
12), and in front of the driver's seat (10) are a meter panel (13) and a steering wheel (14).
is provided.

Further, a transmission (A) that operates under electrical control is housed inside the transmission case (3), and this transmission (A)
As shown in FIGS. 4 and 5, a transmission system and a control system are constructed.

In other words, the transmission system is a gear-type main transmission mechanism (1) in which power from the engine (1) is transmitted via the main clutch (2a).
5), Hydraulic clutch (16), Gear type forward/backward switching mechanism (17), Gear type auxiliary transmission mechanism (18), Rear wheel (5)
A traveling drive system consists of a differential device (5a) for the front wheels (4) to which power from the transmission case (3) is transmitted via the intermediate shaft (19), and a main clutch (2a). ), and a working device drive system consisting of a gear-type transmission mechanism (21) that changes the power transmitted through a four-speed gear and transmits it to an external power output shaft (SIO), and a main transmission mechanism (15). are two shift cylinders (22) and (23), and the forward/reverse switching mechanism (17) and the sub-transmission mechanism (18) are operated by a single shift cylinder (24) and (25), respectively.
, these shift cylinders (22), (23),
(24) and (25) are the corresponding solenoid valves (2
2ν), (23V), <24V), (25
Furthermore, the hydraulic clutch (16) is controlled by an electromagnetic proportional pressure reducing valve (26).

And this transmission bag? The operation sequence of Z (A'') is set such that after the hydraulic clutch (16) is disengaged, a desired shift cylinder is operated, and after this operation, the hydraulic clutch (16) is engaged and operated.

In addition, the control box (12) has a push operation (
Press the switch (2) to raise the ground work equipment to the desired level relative to the vehicle body by pressing the switch (ON operation), and lower the ground work equipment to the original level by pressing it again (OFF operation).
7), and this agricultural tractor has a switch (27).
) control to change the vehicle speed to the desired speed at the same time as the push operation.

system is also provided.

Further, these controls are performed by a control device (28) having a microprocessor (not shown), as shown in FIGS. 1 to 3.
As shown in FIG. 7, signals from a vehicle speed setting mechanism (29) having a large number of push buttons (29a) are inputted to this control device (28) via an encoder (30), and the A signal is input from the switch (27), and a signal is input from the preset input mechanism (31) having a dial (31a) as shown in FIG. is the encoder (3
2), and a preset switch (
33) are respectively inputted, and this control device (2
8) outputs a signal via a decoder (35) to a gear stage display mechanism (34) that uses light emitting diodes to indicate the traveling direction of the vehicle (indicated by F-R) and the gear stage. When a gear shift is performed when the switch (27) is pressed, a signal is output via the decoder (37) to a preset gear display mechanism (36) that indicates the gear gear using a light emitting diode, and the electromagnetic A signal is output to the proportional pressure reducing valve (26) via the D/A converter (38), and the four solenoid valves (22V), (23V), (24V) for speed change are output.
, <25V) outputs a constant signal, and also outputs a constant signal from the lift cylinder (
A signal system is formed to output signals to the electromagnetic valves (6v) for 6), respectively.

The operation of the control device (28) follows the flowchart shown in Fig. 2, and when the control is started, the flag is first set to "O"(#1 step), and the signal from the preset switch (33) is activated. If input and ON status (#2
．． #3 step), input the signal value (F n-P) from the precent input mechanism (31) #4 step), and store this signal value (Fn-P) in the memory (M) (
#5 step). Next, input the signal from the switch (27) (#6 step), and if this switch (27) is pressed (ON operation) (#7 step), after determining the flag (#8 step) , lift arm (7)
to a predetermined level (#9 step), and
After reading the signal value (Fn・P) from the memory (M), a gear shift operation is performed to the gear position corresponding to this value (#10
, #11 step).

Also, the speed changed in this way is stored in another memory (not shown).
(step #12), and the gear position is displayed on the preset gear display mechanism (36) (step #13).
, the flag is set to "1".

This state of raising the lift arm (7) and traveling at the preset speed continues until the switch (27) is pressed again (OFF operation).
, #8 step) and #7 step, when it is determined that the switch (27) has been pressed again, the lift arm (
7) to release the forced rise and return the rotary tiller (9) to the elevation control state before the rise (#15 step), and restore the original vehicle speed by the following steps #16 to #21. It has become.

In other words, the operations in steps #16 to #21 are for performing a single gear shift according to the vehicle speed setting mechanism (29) described above, and in this routine, the signal from the vehicle speed setting mechanism (29) must be input (step #16). , read out the gear position stored in the memory by step #12 described above or step #22 described later (step #17), and if there is a difference in the result of comparing the input signal value and the memory value. (Steps #18 and #19), the input signal value is set as a shift target (Step #20), and a shift operation is performed (Step #21).

Also, after this gear shifting operation, the shifted gear stage is stored in the memory (step #22), and the gear stage display mechanism (34
) to display the gear position (#23 step).

Incidentally, the lifting control according to the setting device represented by step #15 means that when the rotary tilling device (9) is connected to the vehicle body as shown in Fig. 8, the lifting control according to the setting device shown in step #15 means A rotary tiller is used to maintain the swinging posture of the rear cover (9a), which is swingably connected to the rear cover (9a), at a target posture set by a tilling depth setting device (not shown) provided in the control box (12). This refers to control for raising and lowering the device (9), and the form of control differs depending on the type of work device and the purpose of the work.

The basic configuration of the present invention is shown in FIG.
The priority control means (C) consists of steps #10 and #11.
It consists of steps, and the forced rise means (D) consists of #9 steps.

[Another example]

In the present invention, in addition to the embodiments described above, for example, the control means, the priority control means, and the forced increase means may be configured in hardware using logic gates, comparators, etc.

Further, the ground work device may be a plow or a lawnmower.

Incidentally, although reference numerals are written in the claims section for convenient comparison with the drawings, the present invention is not limited to the structure shown in the accompanying drawings.

[Brief explanation of the drawing]

The drawings show an embodiment of the agricultural tractor according to the present invention.
Figure 2 is a complaint correspondence diagram showing the configuration of the speed change control system, Figure 2 is a flowchart showing the operation of the control device, Figure 3 is a block circuit diagram showing the configuration of the speed change control system, and Figure 4 is a diagram of the travel transmission system. , Figure 5 is a hydraulic circuit diagram for variable speed drive, Figure 6 is a front view of the meter panel, Figure 7 is a perspective view of the vehicle speed setting mechanism,
FIG. 8 is an overall side view of the agricultural tractor. (9)...Ground work equipment, (27)...
・Switch, (29)...Vehicle speed setting mechanism, (A
)...Transmission device, (B)...Control means, (C)...Priority control means, (D)...
・Forced rise means, (M)... Memory means.

Claims (1)

[Claims] The ground work device (9) is activated by turning on the switch (27).
) to a predetermined level relative to the vehicle body, and is equipped with a forced lifting means (D) for lowering the ground working device (9) to the level before raising by turning off the switch (27). , a transmission (A) operated by electrical control, a vehicle speed setting mechanism (29) that selects the traveling speed of the vehicle body by human operation, and a transmission (A) based on a signal from this vehicle speed setting mechanism (29). Each of the control means (B) for controlling the speed change operation is provided, as well as a storage means (M) for storing a preselected running speed of the vehicle body, and a storage means (M) for storing the traveling speed of the vehicle body selected in advance, and a control means (B) for controlling the vehicle speed setting mechanism (29) when the switch (27) is turned on. The gear shifting operation is performed based on the value stored in the storage means (M) with priority over the signal, and
The agricultural tractor is provided with a priority control means (C) for performing a speed change operation in order to restore the vehicle speed to the signal based on the signal from the vehicle speed setting mechanism (29) by the OFF operation of 7).