JPH0245278A - Steering controller for trailer pulled by tractor - Google Patents

Abstract

PURPOSE:To enable the direction change of a trailer pulled by a tractor by pivotally supporting a front end side of a pair of tracting members by means of a support lever pivotally mounted on a draw bar on the tractor side, and steering the trailer according to the relative position between the draw bar and the support lever. CONSTITUTION:In a device where a draw bar 2 is e quipped with a traction member 3 through which a trailer 4 is connected, the member 3 is provided with a traction bar 20 and a sub-bar 21 parallel thereto. An end of the bar 20 on the side of the bar 2 is connected to a base body connected to the bar 2 by means of a support shaft 23 on which the central part of an L-shaped support lever 27 is supported. One end of the sub-bar 21 is journaled to the tip end of one of arms 27a of the lever 27 while at the tip end of the other arm 27b a displacement detecting sensor 30 is set to detect the change of the relative position between the bar 2 and the lever 27, controlling a steering mechanism 15 of the trailer 4.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a steering control device for a trailer, for example, for driving an agricultural work vehicle (hereinafter referred to as a trailer) towed by a tractor along a predetermined travel route. Pause.

(Prior Art) As an example of the above-mentioned trailer steering control device, there is, for example, the special patent application No. 1982-289472, which was previously filed by the applicant of the present invention.The outline thereof is shown in FIGS. 5 and 6.

The tractor 100 has a traction rod 101 pivotally supported at the rear thereof so as to be swingable in the left and right directions, and a trailer 102 is connected to the tip thereof. The tow rod 101 consists of a long main rod 103 and a short sub-rod 104, which are connected by a pin 105, and the tip of the main rod 103 is supported by the tractor 100, and the rear end of the sub-rod 104 is supported by the trailer 102. . 1
06 is a cylinder for ridge alignment, and is provided between the trailer 102 and the main rod 103.

The trailer 102 is equipped with wheels 107, 108 on both sides. The wheels 107 and 108 are each attached to one arm of each of L-shaped arms 111 and 112 that are swingably supported on the vehicle body frame 110, and the other arm is connected to the one arm 111 by a connecting rod 113. A hydraulic cylinder 114 is attached to these L-shaped arms 111.
112, a connecting rod 113, and a hydraulic cylinder 114 constitute a steering mechanism 115.

In addition, a hit angle detection sensor 120 is provided on the shaft support of the main rod 103 of the tractor lOO.

Thus, the tractor 100 is caused to travel along the arc C by operating a steering operation mechanism (not shown). As a result, the axis 121 of the tractor 1000 and the main rod 103 form an angle (pitch angle) 122. This angle is detected by the hitch angle detection sensor 120, converted into an electric signal, and then sent to the steering mechanism 115 by an arithmetic circuit (not shown).
, and performs a neck motion of the wheels 107 and 108.
Transition along a predetermined travel path.

[Problem to be solved by the invention]

When the trailer 102 is an agricultural work vehicle, it is necessary to shift the trailer 102 eccentrically from the traveling axis of the tractor 100 in order to align the trailer. For this operation, the hydraulic cylinder 106 for ridge alignment is operated, and the main rod 103 and the sub rod 104 are
An angle α1 is formed between the two. This angle is tractor 10
0, when the trailer 102 moves straight, the hit angle α2
(hereinafter referred to as ridge alignment angle).

Therefore, when the tractor 100 changes direction in this state,
It is necessary to add or subtract from this angle α2 to operate the steering mechanism 115 of the trailer 102.

In this case, the ridge alignment angle is not constant and needs to be changed. Therefore, when changing the direction of the tractor 100, it is necessary to always consider the undulation angle, which makes the operation complicated.

In view of this, an object of the present invention is to move a trailer following the direction change of a tractor without having to consider the ridge alignment angle.

[Means to solve the problem]

To achieve the above object, the present invention provides a trailer towed via a traction member attached to a drawbar of a tractor, in which the traction member includes a traction bar connecting the drawbar and a trailer front frame, an auxiliary bar parallel to the traction bar, The traction member is provided with a support bar that connects both bars on the drawbar side. A displacement detection sensor is installed in the middle of the trailer, and the displacement detection sensor detects a change in the relative position between the drawbar and the support lever due to a change in direction of the tractor, and the trailer steering operation mechanism is operated based on the displacement value. It is.

In this case, it is preferable that the displacement detection sensor uses a length measuring potentiometer that measures a change in the relative position between the draw bar and the support bar in the longitudinal direction.

[For production]

The support lever is always parallel to the trailer front frame even when the trailer is deviated to the tractor travel line for ridge alignment, and its relative position to the drawbar does not change.When the tractor direction changes, the above-mentioned relative position changes. . By detecting this and operating the trailer's steering mechanism, the trailer changes direction to follow the tractor.

〔Example〕

1 to 4 show embodiments of the present invention.

The tractor 1 is equipped with a drawbar 2 at the rear, a traction member 3 is attached to the drawbar, and a trailer 4 is connected via this traction member. The trailer 4 is equipped with wheels 5 and 6 on both sides, similar to the Chichi structure, and the wheels 5 and 6 are each attached to one arm of each of L-shaped arms 8 and 9 that are swingably supported on the vehicle body frame 7. and the other arm is attached to connecting rod 1
Connect by 0. One arm 8 has a hydraulic cylinder 1
1 is attached via a lever 12, and the hydraulic cylinder 11 is connected to a hydraulic electromagnetic directional control valve 13, and these L-shaped arms 8, 9, connecting rod 10, hydraulic cylinder 11, and directional control valve 13 constitute a steering mechanism 15. .

The traction member 3 includes a traction bar 20 and a sub-bar 21 parallel to the traction bar 20. Drawbar 2 has a chevron-shaped base 2
2, one end of the traction bar 20 is pivotally supported on a support shaft 23 attached to the base body 22, and the other end of the traction bar 20 is attached to a mounting bracket 25 attached to the front frame 24 of the trailer 4 near the center. It is fixed so that it can rotate freely. Further, the center of an L-shaped support bar 27 is pivotally supported on the support shaft 23, and the sub-bar 21 has one end attached to the tip of one arm 27a of the lever 27, and the other end attached to the bin 28 of the mounting bracket 25. It is pivotally supported and installed parallel to the traction bar 20. Note that this sub-bar has a turnbuckle structure, and the arm 27a of the support lever 27 is parallel to the pins 26 and 28 of the mounting bracket 25. That is, the traction member 3 includes a traction bar 20, an auxiliary bar 21, and a support lever 27.
It has a pantograph structure with a four-bar parallelogram link with the mounting bracket 25, and regardless of the angle between the traction bar 20 and the mounting bracket 25, the arm 27a and the bins 26 to 28 are always parallel. It is.

At the tip of the other arm 27b of the support lever 27, a displacement detection sensor 30 is swingably supported by a pin. This sensor is constituted by, for example, a potentiometer for measuring length, and the movable piece 30a is connected via a spring 31 to a pin 33 of a mounting piece 32 protruding from the base body 22.

35 is a hydraulic cylinder for ridge alignment, which is provided between the traction bar 20 and the front frame 24 and connected to the electromagnetic directional cutoff valve 36. Reference numeral 37 is a deviation angle detection sensor, which forms an acute angle between the traction bar 20 and the mounting bracket 25 using the hydraulic cylinder 35 for ridge alignment, thereby deviations the traveling route of the trailer with respect to the tractor. , a sensor for angle detection is used.

In the figure, 40 indicates an arithmetic control circuit.

In the above configuration, when it is necessary to deviate the trailer 4 with respect to the tractor 1 for alignment, the traction bar 20 forms an acute angle with the mounting bracket 25 by actuation of the hydraulic cylinder 35. The offset position has a correlation with the acute angle, is detected by the offset angle detection sensor 37, and is regulated by the arithmetic control circuit 40. In this case, the arm 27a of the support lever 27 is attached to the mounting bracket 2 as described above.
5 are always kept parallel and stationary, as shown in FIG. 2, regardless of the angle. Therefore, the displacement detection sensor 30
will never operate.

Next, when the tractor 1 changes direction and moves along the arc C shown in FIG. 3, the drawbar 2 rotates about the support shaft 23 as shown in FIG. 4. Therefore, the pin 33 provided on the mounting piece 32 has a radius R around the support shaft 23.
Move on the arc of 1. The displacement detection sensor 30 swings around the pin 34 at the tip of the arm 27b of the support lever 27. R2 indicates the transition locus of the tip of the fixed portion of the sensor.

The difference P between the radii R1 and R2 is proportional to the rotation angle α3 of the bin 33 in FIG. 4, which is the rotation angle for changing the direction of the tractor I. Therefore, the pull-out distance of the movable piece 30a of the sensor 30 is proportional to the angle α3. This pull-out distance is converted into an electrical signal and applied to the arithmetic and control circuit 40, and the circuit 40 uses the steering mechanism 1 of the trailer 4 based on this.
5 to change the pointing direction of the wheels 5 and 6 so that the trailer 4 moves along a trajectory with a predetermined radius D.

〔Effect of the invention〕

The present invention has the following effects. The traction member that pulls the trailer consists of a traction bar, an auxiliary bar, and a support lever, and has a parallelogram pantograph structure together with the front frame of the trailer, so the angle between the traction bar and trailer is changed to align the traction. Even if the support bar is parallel to the trailer front frame and does not displace, its position relative to the tractor drawbar does not change. Therefore, the drawbar changes its position relative to the support lever only when the tractor changes direction, and by detecting this change, the steering mechanism is actuated to guide the trailer along a predetermined travel path. It is the sum of the angle between the towing rod that pulls the tractor and the tractor travel axis (Hitschi angle), the angle for ridge alignment, and the angle for changing the direction of the tractor. can.

Further, according to the present invention, the relative position between the drawbar and the support lever can be reliably measured by using a length measuring potentiometer.

Furthermore, a hydraulic cylinder for ridge alignment can also be provided between the traction bar and the trailer in the same manner as in the known structure, resulting in a simple structure.

[Brief explanation of the drawing]

Figures 1 to 4 show embodiments of the present invention, with Figure 1 being an overall schematic illustration, Figure 2 being an illustration of the ridge alignment operation, and Figure 3 being an illustration of running when changing the direction of the tractor. , FIG. 4 is an explanatory diagram of the operation of the displacement detection sensor, FIGS. 5 and 6 are illustrations of a conventional example, FIG. 5 is an overall schematic explanatory diagram, and FIG. 6 is an explanatory diagram of the ridge alignment procedure. 1 is a tractor, 2 is a drawbar, 3 is a traction member, 4 is a trailer, 15 is a steering mechanism of the trailer, 20 is a traction bar, 21 is an auxiliary bar, 24 is a trailer front frame, 27 is a support lever 30 is a displacement detection sensor . Summary 1 Figure 1, Torageta

Claims (2)

[Claims] (1) In a trailer that is towed via a traction member attached to the drawbar of a tractor, the traction member connects the traction bar that connects the drawbar and the front frame of the trailer, the auxiliary bar that is parallel to this, and the traction bar that connects both bars on the drawbar side. The traction member includes a support lever having a parallelogram pantograph structure together with the trailer front frame, which always maintains the support lever parallel to the front frame, and a displacement detection sensor is provided between the support lever and the drawbar. , a trailer towed by a tractor is characterized in that a change in the relative position between the drawbar and the support lever due to a change in direction of the tractor is detected by a displacement detection sensor, and a steering operation mechanism of the trailer is operated based on the detected displacement value. Steering control device. (2) The steering control device for a trailer towed by a tractor according to claim 1, wherein the displacement detection sensor is constituted by a length-measuring potentiometer arranged between the drawbar and the support lever.