JPS58191823A - Controller for motor grader - Google Patents

Abstract

PURPOSE:To make the face of a draw bar coincide with a finished face by a method in which the first cylinder is provided at one end of the draw bar, while paired second and third cylinders are provided at the other end, and the lengthwise and crosswise inclination angles of the draw bar are detected and each cylinder is controlled. CONSTITUTION:The rod of the first cylinder 11 is pivotally attached to the frame 17 of the front wheel for a motor grader, one end of the draw bar 12 is pivotally attached through a ball joint 13 to the first cylinder 11, the other end of the draw bar 12 is pivotally attached to the rods of the second and third cylinders 10 and 10', and the second and third cylinders are pivotally attached to a body frame 14. Also, an inclinometer 20 to detect the lengthwise inclination angle of the draw bar and an inclinometer 21 to detect the transverse inclination angle of the draw bar are provided to the draw bar 12. On the basis of the outputs of the first and second inclinometers 20 and 21, the cylinders 10 and 10', 11 are controlled in such a way as to parallel a desired finish face with the face of the draw bar 12.

Description

[Detailed description of the invention] The present invention relates to a control device for a °C-tag radar.

In general, motor graders are
As shown in b), one end of the drawbar 1 is supported by a ball joint on the frame 2, and the other end of the drawbar 1 is suspended from the frame 2 by a pair of cylinders 3.3'. A circle 4 is rotatably disposed at the lower part of the other end, and a blade 5 is integrally supported by the circle 4. In such a motor grader, the inclination angle of the blade 5 is set by raising or lowering one of the pair of cylinders 3, 3'.

By the way, the blade 5 of the motor grader is not only positioned perpendicular to the direction of movement of the grader, but also is used by changing the angle depending on the ground condition and the like.

At that time, for example, as shown in FIG. 2(b), the circle 4
is upward in the direction of movement of the grader (arrow
) at angle θ1. When moving to U, the heights of points A and B on the line m of the blades 5' and 5' at each position become a and b (aqb) as shown in FIG. 2(b). Therefore, in such a case, the inclination angle of the blade must be corrected (circle correction) each time according to the rotation angle of the circle 40. This is the same even when an inclinometer is installed on the blade and the blade is controlled so that the angle of inclination is always constant.

Therefore, in the conventional motor grader, as shown in Fig. A total of 8 cylinders are used, and calculations are performed based on the data obtained from these, and as a result, the cylinder is raised and lowered to control the blade.

Here, the above calculation will be explained with reference to FIG.

Figure 3 shows a slope (θB) in the direction of movement of the grader (X-axis direction).
) is a coordinate system showing the positions and angles of each part when leveling a slope (AHCK) at a finishing angle (θf).

In addition, each symbol in Fig. 3 is respectively θ wisteria, blade inclination angle 0 Hata: inclination angle in the road surface advancing direction (vehicle body longitudinal direction σ) inclination angle) Uc: circle inclination angle (draw) (usurpation oblique angle) 0D : Drawbar inclination angle (draw/(vertical inclination angle) Of=finished surface transverse inclination angle R: Rotate angle (rotation angle of the blade) ABCD Ni-blade rotating surface AHCK: Finished surface IFCD: Drono with θB=o (and JFC/K: Running road surface EFCG: Indicates a horizontal surface.

Therefore, if AC= l, -min de C and plane are
It is expressed by the following equations (1) and (2).

FC-eCOaRCOmuC゛°(1)HF = /a
in#B-7! sinReosODtan6g −
+21 As a result, tanθf becomes as shown in the following equation (3).

Incidentally, in the case of regular ground leveling work, the cutting depth of the blade of a motor grader is approximately 415 cm, which is extremely small compared to the total length 21 of the blade. Therefore, the angle of,
θD is minute. Also, if the slope of the road surface is almost horizontal, it can be approximated as follows. By the way, when formula (4) is substituted into formula (3), elf = θ - θ, 5ainR os R. If we rearrange this formula for θB, we get θl - θ
(@co@R+θ8sinR-(5).

That is, once the finishing angle of is set, the blade inclination angle θB can be calculated by substituting the road surface inclination angle # and the rotation angle R into the above equation (5), and the calculation result and the actual blade can be calculated. Circle correction can be performed by raising and lowering the cylinders 3, 3' so that the inclination angles match.

However, the circle correction as described above 1) makes the arithmetic circuit complicated and increases the number of failure factors.

2) If Of, #D is not sufficiently small, the approximation shown in equation (5) cannot be used. 3) In the case of 2), θB must be calculated using equation M(3), but in this case, There was a problem that the calculation became more complicated.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a control device for a motor grader that does not require circle correction.

According to this invention, in addition to the pair of cylinders that move the other end of the drawbar up and down and tilt it, a cylinder that moves one end of the drawbar up and down is provided, so that the desired finished surface and the drawbar surface are at least parallel. These cylinders are controlled in such a way as to eliminate the need for circle correction.

Hereinafter, the present invention will be explained in detail with reference to the accompanying drawings.1 First, the present invention will be explained in principle. It is clear that when the desired finished surface and the drawbar surface are made parallel, it becomes unnecessary to correct the inclination angle of the blade each time according to the rotation angle of the circle (circle correction). It is also possible to simply make the drawbar surface parallel to the desired finished surface by controlling a conventional pair of cylinders provided at the other end of the drawbar, but in this case, the blade height is controlled. Therefore, the present invention provides a pair of cylinders 10. as shown in FIGS. 4 and 5. In addition to 10', cylinders 11 are provided, and by controlling these cylinders, the desired finished surface and the drawbar surface are made parallel, and the height of the blade can also be controlled.

4 and 5, a drawbar (12) has one end supported by a frame 14 by a ball joint 13, and the other end suspended from the frame 14 by a pair of cylinders 10 and 10'. 1
A circle 15 is rotatably arranged at the bottom of the other end of 2,
A blade 16 is integrally supported by the circle 15.

On the other hand, the cylinder 11 is disposed at the tip of the frame 14, and its cylinder rod l1m is disposed on the frame 17 of the front wheel.

Next, control of the cylinders 10, 10' and 11 will be explained.

First, as shown in FIG. 6(a) and FIG. 6(b), a drawbar longitudinal direction inclinometer 20 detects the inclination angle of the drawbar 12 in the longitudinal direction and the inclination angle of the drawbar 12 in the lateral direction is detected. A drawbar lateral inclinometer 21 for detecting the angle of inclination of the road surface is disposed at the rear of the motor grader. In addition,
The motor glitter moves forward and backward due to the expansion and contraction of the cylinder 11, but the road surface advancing direction inclinometer 22 detects the inclination angle in the forward and backward direction of the road surface regardless of the expansion and contraction of the cylinder 11. It is disposed on a frame 25 or the like that connects 24.

FIGS. 7 and 8 are block diagrams showing one embodiment of a control device according to the present invention. In FIG. 7, the finished surface transverse inclination angle setter 3o is for setting the transverse inclination angle of a desired finished surface, and outputs a signal corresponding to the transverse inclination angle θf to the subtractor 31. A signal corresponding to the drawbar bucket direction inclination angle θC is added to the other input of the subtractor 31 from the drawbar lateral inclinometer 21 disposed on the drawbar 12, and the subtracter 31 calculates the deviation of these two human power signals. This deviation signal is sent to the actuator drive unit 33 via the amplifier 32.
Add to.

The actuator drive section 33 is composed of a solenoid valve and the like that controls the direction of the pressure oil, and operates the cylinder 10. 10'. The lateral inclination angle of the drawbar 12 is controlled by the difference in the length of each rod of the cylinder 10, 10', and the drawbar lateral inclinometer 21 outputs a signal corresponding to the inclination angle θC.

The drawbar 12 is controlled by the feedback control system so that its lateral inclination angle θC coincides with the finished surface transverse inclination angle 0f.

On the other hand, in FIG. 8, the road surface advancing direction inclinometer 22 detects the inclination angle (vertical inclination angle on the finished surface) θ3 in the road surface advancing direction, and outputs a signal corresponding to this inclination angle U8 to the subtracter 34. A signal corresponding to the drawbar longitudinal direction inclination angle θD is applied to the other input of the subtractor 34 from the drawbar longitudinal direction inclination 1ti20 disposed in the drawbar 12,
The subtracter 34 takes the deviation of these two human power signals, and applies this deviation signal to the actuator drive unit 36 via the amplifier 32.The actuator drive unit 36 supplies pressure oil to the cylinder 11 in accordance with the signal from the amplifier 32, The cylinder 11 is driven. The inclination angle of the drawbar 12 in its longitudinal direction is controlled by the length of the cylinder 110, and the drawbar longitudinal direction inclinometer 20 outputs a signal corresponding to the inclination angle θD.

The feedback control system controls the drawbar 12 so that its inclination angle 0D in the longitudinal direction coincides with the inclination angle θ in the road surface traveling direction.

Thus controlling cylinders 10, 10' and 11 - (
By doing so, the drawbar surface can be made parallel to the desired finished surface.

Note that the drawbar surface is cylinder lo, to; tl
By expanding and contracting each by a certain length (however, the direction of expansion and contraction is opposite for cylinder 10°10' and cylinder 11), it is possible to easily move the blade in parallel, and the height of the blade can be changed as appropriate. reactor. Further, in this embodiment, the inclination (J+ angle) in the road surface traveling direction is detected by an inclinometer, but it may be set in advance in the same manner as the finished surface transverse inclination angle.

As explained above, according to the present invention, circle correction is not required, and the finished surface transverse inclination angle can be set only by the drawbar lateral inclination angle, making blade control simple and accurate.

[Brief explanation of the drawing]

Figure 1 (Ml and Figure 1 tb+ are a side view and plan view, respectively, showing the outline of a motor grader, Figure 2 (, ) and Figure 2 (bl, respectively, are for explaining the principle of conventional blade control. Figure 3 shows the coordinate system used to explain the conventional circle correction; Figures 4 and 5 are the front view and perspective view of the uninvented seven-tag radar, respectively. Figures 6(a) and 6(b) show a side view and a plan view of a motor grader according to the present invention, and FIGS. 7 and 8 show an embodiment of a control device according to the present invention. [Blocked 1. 10, 10', 11... Cylinder, 12... Drawbar, 13... Ball joint, 14... Vehicle frame, 15... Circle, 16... Blades, 20, 21, 22... Inclinometer, 30... Finished surface location inclination angle setter, 31, 34... Subtractor, 33
．． 35...Amplifier, 33.36...Act No. 1! l
! II (b) Figure 2 (()) (b)

Claims (2)

[Claims] (1) a first cylinder disposed at one end of the drawbar; a pair of second cylinders disposed at the other end of the drawbar;
a third cylinder, a first inclinometer that detects the longitudinal inclination angle of the drawbar, a second inclinometer that detects the lateral inclination angle of the drawbar, and the first and second inclinometers. A control device for a motor grader, comprising: a control device for controlling the first cylinder, second cylinder, and third cylinder so that a desired finished surface and a drawbar surface are at least in line with each other based on the output of the motor grader. (2) The control device for a motor grader according to claim 11, wherein the first cylinder is disposed between the frame and the front wheel of the motor grader and moves the front part of the motor grader up and down.