JPH0443130A - Tractor drive control device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a drive control device that controls the drive form of a four-wheel drive tractor.

[Prior Art] Four-wheel drive tractors generally drive all four wheels during normal work, and only drive the rear wheels when traveling on the road or in the field. Conventionally, this switching of the drive mode was performed manually using a switch, lever, or the like.

[Invention tries to solve! [Ili] By the way, when turning, the distance traveled by the front wheels is greater than the distance traveled by the rear wheels, so if you turn with all four wheels driven, the front wheels will act as a brake, making the field rough and making it difficult to turn smoothly. The problem is that it cannot be done. This turning requires a large amount of propulsion in soft fields, so four-wheel drive is required, but in relatively hard fields such as uncultivated fields, rear-wheel drive alone is sufficient for turning. .

Therefore, the present invention aims to selectively switch the drive mode according to field conditions to perform efficient and smooth turning.

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

That is, the tractor drive control device according to the present invention has the following features:
It is a drive control device that controls the drive mode of a four-wheel drive tractor, and has two drive modes that drive only the rear wheels, a four-wheel drive mode that drives all four wheels, and a four-wheel drive mode that drives all four wheels at all times. The vehicle is characterized by the ability to select and switch between an auto mode in which front wheel drive is stopped in response to an operation during a turn.

U action] 2WD mode is selected when traveling on the road or in hard fields, 4WD mode is selected when working in soft fields, and auto mode is selected when working in hard fields.

This makes it possible to obtain good running conditions.

That is, when the auto mode is set, the vehicle runs in four-wheel drive during work, and when the vehicle starts turning, it automatically switches to rear-wheel drive due to the operation. Therefore, the front wheels do not exert any braking action, allowing smooth turning.

[Example] Fig. 1 is a diagram showing an example of a tractor in use. In the figure, a plow 6 is attached to a 3P link device 5 provided at the rear of the aircraft. Note that the 3P link device 5 includes one upper link 8.
and a pair of left and right lower links 9.9, these links 8
, 9. A connecting frame 10 on the plow side is attached to the rear end of the plow. Drive arm 1 driven by hydraulic cylinder 12
The tip end of the drive arm 13.13 and the middle part of the lower link 9.9 are connected by connecting rods 14,14.
By rotating the plow 13 up and down, the plow 6, which is a working part, is raised and lowered.

The tractor 1 is provided with an engine 16 at the front and a mission case 17 at the rear. FIG. 2 is a partially expanded cross-sectional view of the mission case 17. Inside the mission case, there are an input shaft 20, a counter shaft 21. The first to third gear mounting shafts 22, 23, 24, the idle shaft 25, the first. 2nd rear wheel drive shaft 26.27, PT
An O-shaft 28 and a front wheel drive shaft 29 are supported in parallel.

Note that the first and second gear attachment shafts 22.23 are not rotatable with respect to each other, and the second and third gear attachment shafts 23.24 are rotatable with respect to each other. In addition, the first and second rear wheel drive shafts 26.2
7 are rotatable with respect to each other.

A gear 30 on the input shaft and a gear 31 on the counter shaft are in mesh with each other, and the engine output input to the input shaft 20 is transmitted to the counter shaft 21. A gear 32 on the counter shaft and a back idle gear 33 on the idle shaft mesh with each other. The first gear mounting shaft 22 has a front gear 34 and a rear gear 35.
are attached in a non-rotatable but slidable manner, and the shifter 36 slides these gears along the shaft to switch between forward and backward speeds.When the gear 31 and the front gear 34 are engaged, the forward speed is set and the reverse speed is set. Idle gear 33 and rear gear 35
When engaged, it becomes reverse speed.

Further, the gear 31 also meshes with a gear 37 on the PTO shaft, and power is transmitted from the counter shaft 21 to the PTO shaft 28.

The second gear attachment shaft 23 and the first rear wheel drive shaft 26 have main transmission gears 38 (1 to 4) corresponding to each other.

39 (1 to 4) are attached respectively.

By sliding the gears 39 (1 to 4) along the first rear wheel drive shaft 26 with the shifters 40 (a, b) and changing the combination of gears to be engaged, the main speed is shifted from 1st to 4th speed. Do this.

Further, a sub-transmission gear 42 (H
, L), and an auxiliary transmission gear 44 (H.

L) is attached, and a shifter 45 is used to switch between high-speed transmission and low-speed transmission. The rotational power of the first rear transmission wheel 26 is once transmitted to the mantle shaft 43 via the auxiliary transmission mechanism, and from the mantle shaft to the second rear wheel drive shaft 27 via gears 47 and 48. 49 inside is a differential device.

Further, power is transmitted from the mantle shaft 43 to the front wheel drive shaft 29 via gears 53 and 54, and a pole clutch 55 is provided at this portion to switch the transmission on and off. As shown in FIG. 3, the pawl clutch 55 includes a plurality of pawls 57. . . . and a recess 58 into which the inner hemispheres of these poles fit. ..., and has a primary side member 59 fitted to the gear 54 and rotatable with respect to the front wheel drive shaft 29, and a six 60 into which the pawls 57, ... are fitted, and a front wheel drive vehicle 29. and a secondary side member 61 non-rotatably attached to the pole 57, by operating the shifter 62.
... in the recessed portion 58. . . , so as to interrupt the power transmission from the secondary side member 59 to the secondary side member 61. As shown in FIG. 3(a), the shifter 62 is normally pushed to the left in the figure by the force of the spring 64, and the pawls 57, . . .・・・
, the power is transmitted from the negative side member 59 to the secondary side member 60, and the front wheel drive shaft 29 is driven. Also,
As shown in FIG. 3(b), when the shifter 62 is moved to the right in the figure, the pole 57. ... fits into the recess 62a of the shifter, so the recess 58. ..., and the drive of the front wheel drive shaft 29 is stopped.

As shown in FIGS. 4 and 5, the switching device 70 of the pole clutch 55 has a motor 71 provided inside the rear wheel fender 67, and is interlocked with a slider 72 and shifter 62 that are linearly moved by the motor. An arm 74 is connected by a wire 75. As shown in the exploded view of FIG. 6, a worm wheel 78 meshes with a worm gear 77 attached to the output shaft 71a of the motor 71, and a roller 79 eccentrically provided on the end surface of the worm wheel is attached to a groove-shaped roller 79 fixed to the slider 72. It is slidably fitted into the rail 80 of. As the motor 71 rotates, the roller 79
Since the slider 72 makes a circumferential movement on the horizontal plane in the figure, the slider 72, which is engaged with the roller by the rail 80, makes a linear movement in a direction perpendicular to the rail 80.

FIG. 7 is an electric circuit diagram for controlling the motor, in which 82 is a mode changeover switch provided on the goo 2 shuttle board, 83 is an auto switch attached to the motor 71, and 84 is a relay switch. Note that the auto switch 2ch 83 is connected to the power supply 86.
It is equipped with a positive contact plate (positive plate) 87 connected to the V terminal by a V terminal, and a negative contact plate (minus plate) 88 connected to the ground.
8 rotates along a plus plate 87. P elastically contacts the appropriate position of the plus plate 87
1 terminal and P2 terminal are respectively provided. The operation will be described below based on the explanatory diagram of FIG.

FIG. 6A shows a stopped state, in which the P2 side of the relay switch 84 is open and no current is applied, and the slider 72 is stopped at the Pll side autostop NA. When the relay switch 84 is operated to P2 bias, the circuit is closed, current flows to the motor 71, and the motor is started (FIG. 2(b)).

Along with this, the minus plate 88 rotates and the slider 72 moves in a predetermined direction (see Fig.
)) When the negative plate 88 rotates 1800 times, the P2 terminal rides on the negative plate 88, opening the circuit, stopping the motor 71, and
The movement of the slider 72 also stops (FIG. 2(d)), and at this time the slider 72 is located at the P2 side auto-stop position B. In this state, when the relay switch 84 is operated to the P side, the motor 71 starts and the slider 72 starts moving in the opposite direction ((e) and (f) in the same figure).
).

When the minus plate 88 rotates 3,600 times, it enters the initial state, and the motor 71 and the slider 72 stop.

In this way, the motor 71 is activated only at the start of mode switching operation.
The structure is such that current flows through the motor 71 and no current flows through the motor 71 when the motor 71 is stopped.

It is economical with low power consumption, and is safe with little risk of malfunctions due to electrical leakage.

The stroke L of the slider 72 is set in accordance with the operating range of the shifter 62, and the slider 72 is set in accordance with the operating range of the shifter 62.
When moving from position 11A to position 11B, wire 75 is pulled, and shifter 62 is moved from the position shown in FIG. 3(a) to the position shown in FIG. 3(b). Also, the slider 72 moves from B to A.
When the shifter 62 moves to , the tension of the wire 75 is released, and the repulsive force of the spring 64 causes the shifter 62 to return to its original position.

When the mode switch 70 is set to r2WDJ, the pole clutch 55 is disengaged, resulting in a 2WD mode in which only the rear wheels 3.3 are driven. When set to r4WDJ, the pole clutch 2ch 55 becomes a human and becomes a 4WD mode in which all four wheels are driven. Also, ``When set to AUTOJ, all four wheels are normally driven, but the steering
In conjunction with the operation of 9, the drive of the front wheels 2, 2 is stopped, resulting in an auto mode. The vehicle is set to 2WD mode when driving on the road or in the field, and set to 4WD mode when a large amount of propulsion is required, such as when working or climbing steep slopes. Also, when the field is uncultivated, such as when plowing or plowing with a plow or rotary, the automatic mode is set. When set to auto mode, the machine is in 4WD mode while working, but automatically switches to 2WD mode when turning, allowing smooth turns without disturbing the field with the front wheels.

Compared to gear clutches, pawl clutches, etc., the Pole Clair 2,000 requires less operating force for switching, so it has the advantage of being able to perform switching operations smoothly. This makes it possible to perform switching operations using a motor, making electrical control easier. Furthermore, the overall configuration is simpler and cheaper than when a hydraulic clutch is used. Furthermore, by configuring the shifter to be driven via a wire, the installation location of the motor can be set arbitrarily. The inner part of the fender 67 is not affected by vibration or heat, and there is no risk of it being covered with mud or water, so it is a convenient location for installing the motor.

Next, FIG. 9 shows a transmission case of a different tractor. This mission case 17' is basically similar in structure to the mission case 17, so parts with the same function and the same name will be referred to as "'". It is written with . The difference between this mission case 17'' and the mission case 17 described above is that a speed doubler mechanism 90 is installed on the front wheel drive shaft 29'.
The 0x speed mechanism 90 is provided to enable smooth turning even in soft fields, and in order to make this double speed mechanism 90 function, a full turn mode is set separately from the three modes described above. The structure of the speed-doubling mechanism 90 will be explained below.

The front wheel drive shaft 29' is separated into a primary shaft 29a and a secondary shaft 29b, and both shafts 29a and 29b are connected by a pawl clutch 91. 92 is a primary claw holder fitted to the primary shaft 29a, 93 is a secondary claw holder fitted non-rotatably but slidably to the secondary shaft 29b, and 94 is the secondary claw holder 93. This is a spring that urges the primary claw holder 92 side. Further, a hydraulic clutch 97 is provided on a hydraulic clutch shaft 96 parallel to the secondary shaft 29a, and the primary side member 98 of the hydraulic clutch and the secondary pawl holder 92 mesh with each other, and the secondary side member of the hydraulic clutch 99 and the secondary claw holder 93 are engaged with each other.

The hydraulic clutch 97 supplies and discharges pressure oil into the cylinder chamber 102 through a through hole 101 provided inside the hydraulic clutch shaft 96, and turns on/off power transmission from the downstream member 98 to the secondary side member 99. At the same time, in conjunction with this, the pawl clutch 9
1 is turned on/off. That is, when the hydraulic clutch 97 is disengaged, the pawl clutch 91 is activated, and power is transmitted directly from the negative secondary shaft 29a to the secondary shaft 29b. Each gear ratio is set so that the circumferential speed of the front wheels at this time is approximately 1.055 times the circumferential speed of the rear wheels. Conversely, hydraulic clutch 9
When 7 is on, the pawl clutch 91 becomes human, and the - next shaft 29
The rotational power of a is transmitted to the secondary shaft 29 via a hydraulic clutch 97.
The power is transmitted to b. At this time, each member 92, 93, 98.99 is adjusted so that the circumferential speed of the front wheel is approximately twice that of the rear wheel.
The gear ratio is set.

When working with a tractor equipped with this speed doubler 90, it is best to set it to auto mode when turning in hard fields, and to full turn mode when turning in soft fields. The wheels are driven together, providing a powerful propulsive force, and the circumferential speed of the front wheels is approximately twice that of the rear wheels, allowing for quick and smooth turns. Note that during normal turns, if there is no slip, the circumferential speed of the front wheels will be about 1.4 times the circumferential speed of the rear wheels, so it is best to set the circumferential speed ratio of the front and rear wheels to be higher than this. .

[Effects of the Invention] As is clear from the above description, the tractor drive control device according to the present invention operates during one operation separately from the rear-wheel drive 2WD mode and the four-wheel drive 4WD mode. There is an auto mode that drives in four-wheel drive and automatically switches to rear-wheel drive when you start turning.In hard fields such as uncultivated fields, this auto mode can be set to make turning smoother and faster. Now I can do it.

[Brief explanation of the drawing]

Figure 1 is a side view of an example of a tractor, and Figure 2 is a side view of an example of a tractor.
A cross-sectional view of a partially expanded case, No. 3
Figures (a) and (b) are sectional views showing different states of the ball crawler 2,000, Figure 4 is a side view of the main parts of the tractor,
The figure is a front view, Figure 6 is an exploded view of the main parts of the clutch switching device, Figure 7 is an electric circuit diagram, Figures 8 (a) to (f) are explanatory diagrams of operation, and Figure 9 is different. FIG. 2 is a partially exploded cross-sectional view of the transmission case of the tractor. l...Tractor, 2...Front wheel, 3...Rear wheel, 16
...Engine, 17.17"...Mission case, 20...Input shaft, 26.27...Rear wheel drive shaft, 2
8...PTO axis, 29.29"...Front wheel drive shaft 29
．． 55...Pole clutch, 62...Shifter, 7o
...mode cut-off switch, 71...motor, 90.
・Double speed mechanism.

Claims (1)

[Claims] (1) A drive control device that controls the drive mode of a four-wheel drive tractor, including a two-wheel drive mode that drives only the rear wheels;
A drive system characterized by a 4-wheel drive mode in which all wheels are driven, and an auto mode in which all four wheels are normally driven, but the drive of the front wheels is stopped due to an operation during a turn, which can be selectively switched. Control device.