JPS63103131A - Control system for attitude of blade of bulldozer - Google Patents

Abstract

PURPOSE:To reduce the weight of working machine as well as simplify the mechanism of the machine by using a system in which the angular velocity of the blade is designated by a tilt lever and an angle lever, and a cylinder 4 is controlled in such a way that the blade is controlled to have a given angle by CPU. CONSTITUTION:The tilting angular velocity and angling angular velocity of a blade 10 are designated by a tilt lever 20 and an angle lever 22. On the basis of input data, in CPU 34, the controlled values of two cylinders 15 and 16 are calculated so that the blade 10 comes to have designated tilting and angling angles. The cylinders 15 and 16 each come to have a given length, and the blade 10 is controlled to a given angle. The occurrence of mechanical interference between the blade 10, C-frame 11, and the cylinders 15 and 16 can thus be completely prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a bulldozer blade attitude control method in which the bulldozer blade is tilted and angled by a cylinder.

[Conventional technology]

1. A conventional structure in which the blade of a bulldozer is tilted and angled by a cylinder connects a bracket 2 on which the center bin of the blade 1 is disposed and a joint 4 of the C frame 3, as shown in FIG. The blade 1 is arranged with respect to the C frame 3 so as to be rotatable around two axes, a center pin and a joint 4, and between the C frame 3 and the blade 1, two angle cylinders 5a, 5b and one angle cylinder are installed. It is constructed by attaching a tilt cylinder 6.

When the blade 1 is angled to the left or to the right, the length of the tilt cylinder 6 is fixed and the length of the left and right angle cylinders 5a is fixed.

When changing the length of the blade 5b or tilting the blade 1 to the left or right, use the left and right angle cylinders 5.
This is done by changing the length of the tilt cylinder 6 while keeping the lengths a and 5b fixed.

In the figure, 7 and 8 are lift cylinders, and 9 is a pitching prevention iron.

[Problems to be Solved by the Invention] However, the conventional blade tilt and angle control device described above has a large number of cylinders, resulting in a complicated mechanism and an increase in work weight. There's a problem.

The present invention was made in view of the above-mentioned circumstances, and the number of cylinders for tilting and angulating the blade is reduced to two.
A bulldozer blade posture that simplifies handshaking, reduces work weight, and can stop blade operation if the tilt angle and angle angle of the blade exceed the limit angle during tilt or angle operation. The purpose is to provide a control method.

[Means and operations for solving the problem] According to the present invention, the blade is connected to the C frame so as to be tiltable and angular, and the blade is connected to the C frame so as to be able to tilt and angle freely, and there is a gap between the blade and the C frame depending on the combination of the lengths of each cylinder. In the first embodiment, the tilt angle and the angle angle of the blade are uniquely determined. A second cylinder is provided, and the first cylinder is controlled based on the tilt angle and angle angle as control targets. In a bulldozer blade attitude control method that performs combined control of a second cylinder, limit angles of the tilt angle and angle angle of the blade are set in advance, and a target angle of at least one of the tilt angle and the angle angle of the blade is set in advance. Instruct a new target angle to be changed, and change the first angle according to the instruction of the target angle. When the tilt angle and the angle angle of the blade are detected during the combined control of the second cylinder, and at least one of the detected tilt angle and the angle angle exceeds the set limit angle, the first... The operation of the second cylinder is stopped.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

FIG. 2 is a perspective view showing an embodiment of a bulldozer blade mechanism to which the present invention is applied. In the figure, a blade 10 is connected to a C frame 11 so as to be tiltable and angular. That is, the bracket 13 on which the center bin 12 of the blade 10 is disposed and the center shaft 14 of the C frame 11 are connected,
The blade 10 can rotate around the axis of the center bin 12 (angle direction) and around the axis of the center shaft 14 (tilt direction).

Two cylinders 5 and 16 are attached between the blade 10 and the frame 11 to angle and tilt the blade 10. The cylinders 5 and 16 are attached asymmetrically with respect to the attachment site of the blade 10 as shown in the figure, and the cylinders 5 and 16 can perform a combined operation to angle and tilt the blade 10. .

Next, a preferred manner of mounting the cylinders 15, 16 will be explained in detail.

That is, the two cylinders are installed so that the tilt angle and angle angle determined by the left cylinder length and the right cylinder length have the relationship shown in the graph shown in FIG.

Note that in the figure, point O indicates the left and right cylinder lengths when both the tilt angle and the angle angle are zero. Further, when the relationship between the left and right cylinder lengths goes in the direction of the arrow, it means a left tilt, when it goes in the direction of the arrow B, it means a right tilt, when it goes in the direction of the arrow C, it means a left angle, and when it goes in the direction of the arrow, it means a right angle.

In addition, the relationship between the blade movement and the expansion and contraction of the left and right cylinders is as follows.
As shown in Table 1, the cylinder stroke changes are completely different for each of the four operations: left angle, right angle, left tilt, and right tilt.

Table 1 FIGS. 5 and 6 show the preferred mounting manner of the left and right cylinders 15, 16, respectively, in top and rear views of FIG. That is, according to this mounting mode,
As shown in Table 1, left cylinder 15 when left angle
is retracted, the right cylinder 16 is extended, and when the angle is right, the left cylinder 15 is extended, the right cylinder 16 is retracted, and (
(See FIG. 7), and when tilting to the left, both the left and right cylinders retract (see FIG. 8).

Next, a device for controlling the cylinder will be explained.

FIG. 1 is a block diagram showing an embodiment of a bulldozer blade attitude control device according to the present invention.

In the same figure, tilt lever 2o and angle lever
22 commands the tilt angular velocity and angle angular velocity of the blade 10, respectively, and the tilt angular velocity signal generator 24 and the angle angular velocity signal generator 26 command the tilt angular velocity according to the lever operation amount of the tilt lever 20 and the angle lever 22, respectively. An analog signal indicating dr and angle angular velocity 731' is output to the A/D converter 28.

The tilt angle sensor 30 and the angle angle sensor 32 detect the tilt angle and angle angle of the blade 10, respectively, and are composed of, for example, potentiometers that detect the rotation angle of the center shaft 14 and center pin 12 of the blade 10 shown in FIG. be done. These tilt angle sensor 30 and angle angle sensor 32 output analog signals indicating the detected tilt angle α and angle angle β, respectively, to the A/D converter 28.

The A/D converter converts each of the four input analog signals into digital signals and sends them to the central processor 3! ! ! Device (CPU)
Output to 34.

The CPU 34 receives input via the A/D converter 28.
'r Calculate each cylinder system 11111ii of the two cylinders 15#16 so that the blade 30 has the specified tilt angle or angle angle based on the four data (α, β, α, β) to be applied. . Note that details of the operation of the CPU 34 will be described later.

The cylinder control wJ value (flow rate command value to each cylinder) calculated by the CPU 34 is applied to the hydraulic pulp 42 via the amplifier 38-40. Hydraulic valves 42 and 44 are supplied with pressure oil from a hydraulic source (not shown), and supply the required flow rate (including the supply direction) of hydraulic oil according to the flow rate command value input via amplifiers 38 and 40. cylinder 15.16
Add to.

As a result, the cylinders 15, 16 each have a predetermined cylinder length, and the blade 10 is controlled to have the specified tilt angle or angle.

Next, before entering into a detailed explanation of the operation of the CPLJ 34, an overview of the control aimed at by the present invention will be explained.

In the blade structure shown in FIG. 2, the stroke ends of the left and right cylinders 15 and 16 cannot serve as stoppers for regulating the limit angles of the tilt angle and angle of the blade. That is, due to mechanical interference including mutual interference among the blade 1, the C frame, and the cylinder, the limit angle of the tilt angle or angle appears before the cylinder reaches the stroke end.

Figure 4 shows an example of the above limit angles. If the tilt angle α when tilting to the left is positive, and the angle β of the left angle is positive, αnax and αmin are the maximum limits of the tilt angle α, respectively. and the minimum bounding angle, βla
X and βnin indicate the maximum limit angle and minimum limit angle of the angle angle β, respectively. That is, the blade can change its attitude within the range of each of the above-mentioned limit angles (within the range shown by diagonal lines in FIG. 4).

In the present invention, if there is a change in the posture of the blade that exceeds the above range during tilt control or angle control, this is prohibited.

Next, the operation of CP (J34) will be explained in detail with reference to the flowchart shown in FIG.

In FIG. 9, first, the current tilt angle α and angle angle β of the blade are input (step 100). next,
It is determined whether the tilt lever and the angle lever are both neutral (step 110). Note that this determination is made when the tilt angular velocity command α1 and the angle angular velocity command jr are 0.
It depends on whether or not.

When the tilt lever and the angle lever are both neutral, the tilt angle α input in step 100 is
and angle angle β are respectively stored as initial values (α 1 , β 2 ) (step 240).

On the other hand, if at least one of the tilt lever and the angle lever is operated, step 120
Proceed to step 1 and now calculate the length of each cylinder, Lll, of the current cylinder 15.16.

In this calculation, as described above, in the present invention, the left and right cylinders are provided so that the combination of the lengths of the left and right cylinders and the blade posture (tilt angle, angle angle) correspond one-to-one. Conversely, the left and right cylinder lengths are determined from the tilt angle and angle angle.

That is, from the relationship between the left and right cylinder lengths and the blade posture shown in FIG. 3 above, a conversion table for determining the left and right cylinder lengths based on the tilt angle and angle angle is prepared in advance in the memory 36 (FIG. 1). The left and right cylinder lengths determined by the tilt angle and angle angle are then read from this conversion table.

Next, the tilt angular velocity command R and angle angular velocity command β1 are input (step 130), and the target tilt angle α1 and target angle angle β1 are derived from the following equation (step 140).

α ←α1+6r ◆Δt ・・・・・・ (1) β ←βr +5 r・Δt As shown in the above formula, each target angle is obtained by adding the angle amplification valve instructed by the lever to each previous target angle. I try to ask for more. Note that Δt indicates the processing time of one cycle shown in this flowchart. Furthermore, when determining the first target angle, the initial values (α, β0) stored in step 240 are used.

Subsequently, it is determined whether the current tilt angle α is within the range of the preset minimum tilt angle αiin and maximum tilt angle αlaX (step 150). If it is within the above range, proceed to step 170;
If it is not within the range, the process advances to step 160.

In step 160, it is determined whether the absolute value 1αr1 of the target tilt angle α1 obtained in step 140 is smaller than the absolute value 1α1 of the current tilt angle α. And 1α'
In the case of +1α1, the process proceeds to step 170, and 1αr1
If ≧1α1, the process proceeds to step 190.

Similarly, regarding the angle angle, in step 170, it is determined whether the current angle angle β is within the range of the preset minimum limit angle βlin and maximum limit angle βlaX, and whether or not the current angle angle β is within the above range. If it is within the range, the process advances to step 200; if it is not within the range, the process advances to step 180.

Step 180 determines whether the absolute value 1βr1 of the target angle β obtained in step 140 is smaller than the absolute value 1β1 of the current angle β. and,
If 1βr1 minus 1β1, the process proceeds to step 200, and 1
If β1≧1β1, the process proceeds to step 190.

Step 190 is the flow rate command values V, V to the left and right cylinders.
, both output command values of 0. This causes the left and right cylinders to stop operating.

That is, in steps 150 to 180, if both the current tilt angle and the angle angle are within the set limit angle, and even if the set limit angle is exceeded, the absolute value of the control target angle is the absolute value of the current angle. (i.e., when the blade attitude is returned to within the range set by the limit angle), the operation of the cylinder is not prohibited and the process proceeds to the next step 200; otherwise, the process proceeds to step 190. , the blade posture is regulated so as not to exceed a predetermined range.

In step 200, the target angle cylinder lengths (L, r, LRr) are determined from each target angle (α, β1) determined in step 140 in the same manner as in step 120 described above.

Next, the target cylinder length appears as Llr, Rr). Deviation from the current cylinder length (L, L) Δ11° [R ΔJIR is expressed by the following formula, ΔJ=L,'-1゜ ・・・・・・(2) Step 210), this deviation Δj2. .

The flow rate command values V, , V□ for the left and right cylinders required to quickly bring ΔlR to zero can be calculated using the following formula: V = AΔJE+B
ΔR+CΣΔ11・Δt[V=AΔIR+BΔjR+CΣΔJtR・Δt・・
(3) Obtain from (step 220). In addition, in the above formula,
A, B, and C are coefficients of proportional, differential, and integral compensation elements.

The flow rate command value ■ and VR obtained in this way are outputted from the CPU 34 as described above (step 2).
30).

Note that the method of giving the target tilt angle and the target angle angle of the blade is not limited to this embodiment, and the target angle and the target angle may be given directly by, for example, a dial or the like. In addition, the actual cylinder length measurement is not limited to this example where the conversion is made from the blade tilt angle and angle angle.
The cylinder length may also be directly measured.

Furthermore, in addition to the method of determining the flow rate command value for the left and right cylinders based on the target cylinder length and actual cylinder length and deviation, it is also possible to The flow rate ratio of the left and right cylinders is prepared in advance in a memory table, and a desired flow rate ratio is read out from the memory table based on the current blade posture and the tilt or angle operation command of the blade, and the flow rate ratio is set to the read flow rate ratio. The flow rate command values for the left and right cylinders may be determined.

[Effects of the Invention] As explained above, according to the present invention, since there are two cylinders for tilting and angulating the blade, the structure can be simplified. In addition, if the tilt angle or angle angle of the blade exceeds the limit angle during tilt or angle operation, the blade operation is stopped, so the blade, C frame,
Mechanical interference between cylinders can be prevented.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an embodiment of a bulldozer blade control device according to the present invention, Fig. 2 is a perspective view showing an embodiment of a bulldozer blade mechanism according to the invention, and Fig. 3 is a block diagram showing an embodiment of a bulldozer blade control device according to the present invention. A graph showing a preferable relationship between combinations and blade postures, FIG. 4 is a graph showing an example of a possible range of blade postures, FIGS. 5 and 6 are respectively a plan view and a back view of FIG. 2, and FIG. 7 and Fig. 8 are diagrams showing the expansion/contraction relationship of the left and right cylinders during angle and tilt, respectively, and Fig. 9 is a diagram showing the CPLI shown in Fig. 1.
Flowchart showing the processing procedure according to the present invention, No. 10
The figure is an exploded perspective view showing an example of a conventional blade am. 1o...Blade, 11...C frame, 12...
・Senta Bin, 14...Senta Shirt i~, 15.1
6...Cylinder, 20...Tilt lever, 22...
・Angle lever 130...Tilt angle sensor, 32・
...Angle angle sensor, 34...Central processing unit (CP
tJ), 36...Memory, 42.44...Hydraulic pulp. Figure 2 8009001000 11001200130014
00 +500 Hill Confucian IJ Jino> Evening (ko 艷 (mm) Figure 4 Figure 6 Figure 9

Claims (2)

[Claims] (1) A mode in which the blade is connected to the C frame so that it can tilt and angle freely, and the tilt angle and angle of the blade are uniquely determined by the combination of the lengths of each cylinder between the blade and the C frame. In a bulldozer blade attitude control method, a bulldozer blade attitude control method includes providing a first cylinder and a second cylinder, and controlling the first and second cylinders in a combined manner based on a tilt angle and an angle angle as control targets. A limit angle of the angle angle is set in advance, and a new target angle for changing the target angle of at least one of the tilt angle and the angle angle of the blade is specified, and the first and second angles are changed according to the instruction of the target angle. detecting the tilt angle and angle angle of the blade during combined control of the cylinder; and when at least one of the detected tilt angle and angle angle exceeds the set limit angle, the first and second
A bulldozer blade attitude control method, characterized in that the operation of a cylinder is stopped. (2) When at least one of the detected tilt angle and angle angle exceeds the set limit angle, and the absolute value of the control target angle of the angle exceeding the limit angle is greater than or equal to the absolute value of the detected angle; 2. A bulldozer blade attitude control method according to claim 1, wherein the first and second cylinders are stopped in operation.