JPH07116718B2 - Interference prevention control method for work attachment in hydraulic excavator - Google Patents

Description

Description: [Object of the Invention] (Field of Industrial Application) The present invention relates to a method for preventing interference of a work attachment applied to a hydraulic excavator having a work attachment.

(Prior Art) FIG. 16 shows a configuration diagram of a hydraulic excavator. In FIG. 16, an upper revolving structure 1 is provided so as to be rotatable with respect to a lower traveling structure 2, and the upper revolving pair 1 further includes a boom 3 and an arm 4.
And a bucket 5 are provided, and the boom 3 is driven by the boom cylinder 6, the arm 4 is driven by the arm cylinder 7, and the bucket 5 is driven by the bucket cylinder 8.
Driven by. The boom 3, the arm 4, the bucket 5, and the cylinders 6, 7, and 8 that drive each of them are collectively referred to as a work attachment.

The hydraulic excavator having the above-described configuration performs work by combining the turning operation of the upper turning pair 1 and the operation of the work attachment attached to the upper turning pair 1.

FIG. 17 is a plan view of the hydraulic excavator, showing the relationship between the operating range of the bucket 5 and the lower traveling body 2. The bucket 5 and the undercarriage 2 interfere with each other at four points indicated by circles in FIG.
Usually, this interference is prevented by the operator's attention.

(Problems to be Solved by the Invention) As described above, in the conventional hydraulic excavator, the interference between the lower traveling body 2 and the bucket 5 is prevented by the attention of the operator. It has become difficult to ensure sufficient security, and it has become difficult to prevent the above interference only with the attention of the operator.

The present invention proposes an interference prevention control method for a work attachment that can prevent a bucket from interfering with a lower traveling body due to an operator's operation error, and an object thereof is to prevent an increase in operator's burden due to an increase in size of a hydraulic excavator. To do.

[Structure of Invention]

(Means for Solving the Problem) The present invention detects an angle (boom angle αa, arm angle βa, and bucket angle γa) of each node of a work attachment of a hydraulic excavator and a swing angle θ of the upper swing body 1, When the upper revolving structure 1 revolves, the bucket 5 and the lower traveling structure 2 may interfere with each other, and even if the upper revolving structure 1 is stopped, the bucket 5 and the lower traveling structure E may interfere with each other. The turning prohibition angles A, B, C, D that do not interfere with the body 2 are set, and the interference between the lower traveling body 2 and the bucket 5 is prevented by the following control calculation.

(A) Work attachment system control calculation When the bucket 5 comes into contact with the interference danger area E if the bucket 5 is not in the swing prohibition angles A, B, C, D even when the upper swing body 1 is swinging or stopped. Boom limit angle α _L , arm limit angle β _L and bucket limit angle γ _L are determined, and when the actual angles αa, βa, γa of each node approach these limit angles α _L , β _L , γ _L The control signal of each actuator 6, 7, 8 of the attachment is reduced to stop the work attachment.

(B) Revolving system control calculation When the upper revolving superstructure 1 is in a stopped state, the bucket 5 has the above-mentioned turning prohibition angle
If it is in A, B, C, D, the work attachment system control is released and the swing actuator 20 is controlled so that the upper swing body 1 cannot swing.

(Operation) (A) The present invention relates to a work attachment system (boom 3,
When controlling the arm 4 and the bucket 5), in the boom control, even when the operation of lowering the boom 3 is performed when the bucket 5 is above the interference danger area E, the bucket 5 is just before entering the interference danger area E. The boom actuator 6 is stopped, and in the arm control, the bucket 5 causes the bucket 5 to interfere with the danger zone E.
Even if the arm 4 is moved to the side of the undercarriage when the height of the bucket 5 is lower than the height of the bucket, the arm actuator 7 is stopped immediately before the bucket 5 enters the danger zone E of interference. When the bucket actuator 8 is in contact with the area E, the bucket 5 and the lower traveling body 2 are prevented from interfering with each other due to the rotation of the bucket 5.

(B) When the turning system is stopped and the bucket 5 is within the turning prohibition angles A, B, C, D, release the control of (A),
Since the bucket 5 can also be put in the interference danger area E, the turning actuator 20 is controlled so as not to be driven in such a case.

(Example) Hereinafter, the present invention will be described in detail with reference to the examples shown in FIGS. 1 to 15.

(I) Configuration of Control Device FIG. 3 shows the configuration of the control device of the hydraulic excavator for realizing the present invention. In FIG. 3, the boom operating device 9a and the arm operating device 9 provided in the cab of the hydraulic excavator are shown.
b, bucket operation device 9c, swing operation device 9d, and travel operation device 9
e is wire-connected to the input terminal of the controller 10.
The other input terminal of this controller 10 is a boom angle detector.
11, an arm angle detector 12, a bucket angle detector 13, and a turning angle detector 14 are connected by wiring. The controller 10
The interference prevention control calculation is performed based on the angle signal, and the control signal is output.

A valve unit 15 driven based on the control signal of the controller 10 is connected to the output terminal of the controller 10 by wiring, and the input port of the valve unit 15 is a variable discharge hydraulic pump 16, 17, 18, 19 are piped. Reference numerals 16a, 17a, 18a, and 19a denote swash plate controllers that control the discharge amount varying swash plates of the hydraulic pumps 16, 17, 18, and 19 according to control signals from the controller 10.

At the output port of the valve unit 15, a boom cylinder 6, an arm cylinder 7 and a bucket cylinder 8 as actuators for a work attachment, a swing hydraulic motor 20 as a swing actuator for swinging the upper swing body 1, and a lower travel. The traveling hydraulic motors 21a and 21b that drive the left and right wrappings of the body 2 are connected by piping.

(II) Control Method FIGS. 1 and 2 are explanatory diagrams showing an interference range between the bucket 5 and the lower traveling body 2. FIG. 1 is a front view of the hydraulic excavator, and FIG. 2 is a plan view of the lower traveling body 2.
In FIG. 1, the inside of the turning radius R _L and the height H _L (hatched portion) is defined as an interference danger area E, and the bucket 5 is prevented from entering the interference danger area E during turning, and FIG. A, B, shown in
Each of the angles C and D is the turning prohibition angle, and the turning prohibition angles A, B, C, D
If there is a bucket 5 in the
Can be inserted, but the upper revolving structure 1 is prevented from revolving. The inner boundary of the hatched portion shown in the turning prohibition angles A, B, C, D in FIG. 2 is determined by the structural limit of the work attachment.

Interference between the bucket 5 and the undercarriage 2 is prevented by the above two controls. The control method will be described below.

FIG. 4 is a control calculation flowchart, FIG. 5 shows a work attachment system control calculation block diagram, and FIG. 6 shows a turning system control calculation block diagram.

In FIG. 4, S ₁ is a data input unit, and the boom angle detector 11, the arm angle detector 12, the bucket angle detector 13 and the turning angle detector 14 are used to detect the boom angle αa and the arm angle shown in FIG. βa, bucket angle γa, and turning angle θ are detected and read. Further, the output signals of the boom, arm, bucket, and turning operation devices 9a, 9b, 9c, 9d are read. S ₂ is a turning angular velocity calculation unit, which obtains the turning angular velocity from the turning angle θ. S ₃ determines whether the operator is a turning operation in the turning operation signal determination unit in and turning operation unit 9d of the output signal level of the. S ₄ is a turning angular velocity determination unit, which determines whether or not the vehicle is turning at the turning angular velocity obtained in S ₂ .
S ₅ is pivoted position determination of the bucket 5, determines the turning prohibition angle A of the bucket 5 is a second view, B, C, whether contained in D.

If the bucket 5 is turning by the determination unit of S ₃ , S ₄ , S ₅ or the turning system is stopped, the bucket 5 has the turning prohibition angles A, B, and B shown in FIG.
If it is not in C or D, the process proceeds to the work attachment control calculation unit S ₆ . Further, when the turning system is stopped and the turning angle of the bucket 5 is within the turning prohibition angles A, B, C, D shown in FIG. 2, the process goes to the turning system control calculation unit S ₇ .

The work attachment system control calculation unit S ₆ and the turning system control calculation unit S ₇ will be described below.

(A) Work attachment system control calculation block S _{6 A} work attachment system control calculation block diagram is shown in FIG. In the Figure _{5, f 1, f 2, f} 3, f 4, f 15 is a subtraction operation _{unit, f 5, f 6, f} 7 is a maximum value selector. f ₈ is an arm limit angle calculator, f ₉ is a boom limit angle calculator, f ₁₀ is a bucket limit angle calculator, f ₁₁ is an arm correction angle calculator, and f
Reference numerals ₁₂ , f ₁₃ , and f ₁₄ are work attachment operation signal limit value calculators.

Fig. 7 shows arm limit angle calculator f ₈ and boom limit angle calculator f ₉
It is explanatory drawing of the calculation of. In FIG. 7, the broken line portion shows the interference danger zone E, and the arm limiting angle β _L is between the arm R and the boom 3 at a point R where the bucket 5 contacts the interference danger zone E in the fully extended state of the bucket cylinder. It is an angle ∠OPR formed between the joint point P and the joint point O between the boom 3 and the upper swing body 1, and the arm limiting angle β _{L with} respect to the boom angle αa is a function shown in FIG. 8, and the arm corresponding to this function is The limiting angle calculator f ₈ can obtain the arm limiting angle β _L by inputting the boom angle αa using the function of FIG. FIG. 9 shows the inverse function of FIG. 8, and the boom limit angle calculator f ₉ corresponding to this inverse function uses the function of FIG. 9 to obtain ∠OPR = βa−Δβ during actual operation. By inputting, the boom limit angle α _L can be obtained. Δβ is an arm correction angle described next.

FIG. 10 is an explanatory diagram of a calculation method of the arm correction angle calculator f ₁₁ and the bucket limit angle calculator f ₁₀ . In FIG. 10, the arm correction angle Δβ is formed by the connection point Q between the bucket 5 and the arm 4, the connection point P between the arm 4 and the boom 3, and the contact point R between the bucket 5 and the interference danger area E. The angle ∠QRP, and when the bucket 5 is rotated around the point Q, the arm correction angle Δβ and the bucket angle γa are represented by the functions shown in FIG. Arm correction angle calculator f corresponding to this function
_{As for 11} , the arm correction angle Δβ can be obtained by inputting the bucket angle γa using the function of FIG.
FIG. 12 shows the inverse function of FIG. 11, and the bucket limit angle calculator f ₁₀ corresponding to this inverse function inputs the difference Δβe between the arm angle βa and the arm limit angle β _L to obtain the bucket limit angle. The angle γ _L can be determined.

FIG. 13 shows the work attachment operation signal limit value calculator f ₁₂ ,
The functions used in f ₁₃ and f ₁₄ are shown below. Letting the boom cylinder 6, the arm cylinder 7, and the bucket cylinder 8 be operation signals in the extension direction and the signals in the contraction direction, if any of the cylinders moves in the extension direction due to the link mechanism of the work attachment, the bucket 5 is out of the danger zone E of interference. Since it moves in the away direction, the bucket 5 can be prevented from entering the interference danger zone E by limiting the operation signal in the contraction direction of each cylinder 6, 7, 8. Therefore, the work attachment operation signal limit value calculators f ₁₂ , f ₁₃ , and f ₁₄ output the operation signal limit value in the cylinder contraction direction based on the difference between the actual operating angle and the limit angle, as shown in FIG. .

The above is the components of the work attachment system control calculation block diagram, and the operation of this work attachment system control calculation unit will be described below.

Boom control calculation In FIG. 5, the bucket angle γa is calculated as an arm correction angle calculator.
Input to f ₁₁ to obtain the arm correction angle Δβ, and add / subtract calculator f ₁
Then, the difference βa ′ from the arm angle βa is obtained. This adder / subtractor
The angle βa ′ obtained in f ₁ is input to the boom limit angle calculator f ₉ to obtain the boom limit angle α _L , and the addition / subtraction calculator f ₄ obtains the difference ε _α from the actual boom angle _αa . The difference ε _α obtained by the adder / subtractor calculator f ₄ is input to the operation signal limit value calculator f ₁₂ , the operation signal limit value Xbm ′ is obtained, and the maximum value selector f ₅ compares it with the boom operator signal Xbm. , Xbm ′ and Xbm, whichever is larger is output as a control signal.

By this boom control calculation, even if the boom 3 is lowered when there is a bucket above the interference danger area E, the bucket 5
The boom 3 can be stopped before the vehicle enters the interference danger zone E.

Arm control calculation In FIG. 5, the arm angle αa is calculated by the arm limit angle calculator f ₈
The arm limit angle β _L can be obtained by inputting into the equation, and the difference ε _β from βa ′ obtained by the addition / subtraction calculator f ₁ is obtained by the addition / subtraction calculator f ₂ . Difference ε obtained by the adder / subtractor f _2
β is input to the operation signal limit value calculator f ₁₃ to obtain the operation signal limit value Xam ′, and the maximum value selector f ₆ is used to input the arm operation unit signal X
Compared with am, the larger value is output as a control signal.

By this arm control calculation, the bucket 5 causes the danger zone E of interference.
When the height is _HL, it is possible to prevent the bucket 5 and the lower traveling body 2 from interfering with each other when the arm cylinder is contracted.

Bucket control calculation In FIG. 5, the difference Δβe between the arm limit angle β _L and the arm angle βa obtained by the arm limit angle calculator f ₈ is calculated by the addition / subtraction calculator f ₃
Ask in. Then, the difference Δβe is calculated as the bucket limit angle calculator f
Input to ₁₀ to obtain the bucket limit angle γ _L , and add / subtract calculator f
_{At 15} , the difference ε _γ from the bucket angle γa is obtained. The difference ε _γ is input to the operation signal limit value calculator f ₁₄ , and the operation signal limit value Xb
seeking k ', the bucket operating device signals at the maximum value selector f ₇ XBk
And the larger value is output as a control signal.

By this bucket control calculation, it is possible to prevent interference between the bucket 5 and the undercarriage 2 caused by contracting the bucket cylinder 8 when the bucket 5 is in contact with the interference danger area E.

By performing the above boom control calculation, arm control calculation, and bucket control calculation at the same time, the boom 3, arm 4
Even if the operation of the bucket 5 is performed in combination, it is possible to prevent interference between the bucket 5 and the lower traveling body 2 during turning.

(B) Swing system control calculation unit S _{7 If} the bucket is in the swivel prohibition angles A, B, C, D shown in Fig. 2 when the swivel system is stopped, the work attachment system control is canceled. Then, the bucket 5 can be put in the interference danger zone E, but if the turning operation is performed at this time, the bucket 5 and the lower traveling body 2 will of course interfere with each other, so the upper revolving body 1 is controlled not to turn. There is a need.

FIG. 6 shows a block diagram of a turning system control calculation. In FIG. 6, the bucket angle γa is input to the arm correction angle calculator f ₁₁ to obtain the arm correction angle Δβ. Next, the arm angle βa
And the arm correction angle Δβ are obtained by the addition / subtraction calculator f ₁₆ . On the other hand, the boom angle αa is input to the arm limit angle calculator f ₈ to obtain the arm limit angle β _L, and β is set by the addition / subtraction calculator f ₁₇ .
Find the difference ε _β ′ between a ′ and β _L. When the output of the addition / subtraction calculator f ₁₇ is, the bucket 5 is outside the interference danger area E,
At the time of, the bucket 5 is in the interference danger area E. Therefore, the turning system operation signal limit value calculator f ₁₈ is
It becomes the function in Figure 4. In the case of a turning system, it is necessary to control both right turning and left turning. If the right turning is the left turning signal, the operation signal limit value in FIG. 14 is an absolute value. As shown in FIG. 14, the output ε _β ′ of the adder / subtractor calculator f ₁₇ is input to the above-mentioned turning system operation signal limit value calculator f ₁₈ to obtain the operation signal limit value Xsw ′, and the minimum absolute value selector f
_{At 19,} the smaller one of the turning operation device signal Xsw and the operation signal limit value Xsw 'is selected and output.

When the bucket 5 enters the turning prohibition angles A, B, C, D shown in FIG. 2 by the above turning system control calculation, the turning system control signal becomes zero and control is performed so as not to turn. You can

FIG. 15 is a control device configuration circuit diagram of a hydraulic excavator in which a part of electric signals of the interference prevention control circuit shown in FIG. 3 is replaced with a hydraulic pilot system. In this figure, 22a
Is a boom remote control valve, 22b is an arm remote control valve, 22c
Is a bucket remote control valve, 22d is a swivel remote control valve, 22e
Is a remote control valve for traveling system, 23a, 23b, 23c, 23d are electromagnetic proportional pressure reducing valves, 24 is a control pressure selecting valve, 25 is a control valve, 26 is a pilot hydraulic power source, and other components are shown in FIG. It is the same as

The controller shown in FIG. 15 performs interference prevention control calculation in the controller 10, operates the electromagnetic proportional pressure reducing valves 23a to 23d by the output control signal, and controls the control pressure of each actuator 6, 7, 8. 0, the boom 3, the arm 4, the bucket 5, and the upper swing body 1 are stopped, and the bucket 5 and the lower traveling body 2 are stopped.
Prevent interference with.

〔The invention's effect〕

According to the present invention, the interference between the undercarriage and the bucket can be automatically avoided, and the above interference due to an operator's operation error can be prevented. Further, the operator can operate without worrying about the interference, and the operation becomes easy. Further, it is possible to prevent the above-mentioned interference in a place where the visibility of the large hydraulic excavator is insufficient.

Furthermore, according to the present invention, while the upper revolving structure is revolving, the work attachment system control detects the posture of the work attachment so that the bucket does not enter the danger zone of interference and determines the work range of each member. Although it is regulated, in the turning system control when the upper revolving structure is stopped and the bucket is within the turning prohibition angle, the work attachment system control is canceled and the bucket is prohibited from turning. Since the swinging operation of the upper swing body is only restricted until it comes out of the corner, it is possible to put the bucket in the interference danger area and perform the work.

Further, according to the present invention, the boom angle, the arm angle and the bucket angle are detected to obtain the boom limit angle, the arm limit angle and the bucket limit angle according to the posture of the work attachment, respectively, and the boom, arm and bucket operation ranges are obtained. The work range of each member of the boom, arm, and bucket can be individually regulated by any operation, so that a highly feasible control method can be obtained.

[Brief description of drawings]

1 to 15 relate to a method for controlling interference prevention of a work attachment in a hydraulic excavator according to the present invention,
1 is a front view of a hydraulic excavator showing an interference danger zone E, FIG. 2 is a plan view of a lower traveling body of the hydraulic excavator showing turning prohibition angles A, B, C, D, and FIG. 3 is for interference prevention control. Device schematics,
FIG. 4 is a flowchart for interference prevention control calculation, FIG. 5 is a work attachment system control calculation block diagram, FIG. 6 is a turning system control calculation block diagram, FIG. 7 is an explanatory diagram of arm limit angle and boom limit angle, FIG. 8 is a function showing the relationship between the boom angle αa and the arm limiting angle β _L , and FIG. 9 is a function showing the relationship between the boom limiting angle α _L and the difference βa ′ between the arm angle βa and the arm correction angle Δβ. Figure 10 shows arm correction angle Δβ
And FIG. 11 is an explanatory view of the bucket limit angle γ _L , FIG. 11 is a function showing the relationship between the bucket angle γa and the arm correction angle Δβ, and FIG. 12 is a bucket with respect to the difference Δβe between the arm angle βa and the arm limit angle β _L. function indicating the relationship between limit angle gamma _L, FIG. 13 is a function indicating an operation signal limit value of the working attachment system, function Fig. 14 showing an operation signal limit value of the swing system, FIG. 15 prevents interference of the invention Circuit diagram showing another configuration example of the control device, 16th
FIG. 17 is a front view of the hydraulic excavator, and FIG. 17 is a plan view for explaining the interference between the lower traveling body and the bucket. 1 ... Upper revolving structure, 2 ... Lower traveling structure, 3 ... Boom,
4 ... Arm, 5 ... Bucket, 6,7,8 ... Boom cylinder as actuator for work attachment, arm cylinder and bucket cylinder, 20 ... Hydraulic motor as swing actuator, .alpha.a ... Boom angle,
βa ... arm angle, γa ... bucket angle, θ ... swing angle, α _L・ ・ ・ boom limit angle, β _L・ ・ ・ arm limit angle, γ
_L: Bucket limit angle, A, B, C, D ... Turning prohibition angle, E ...
… Interference risk area.

Claims (1)

[Claims] 1. A lower traveling unit, an upper revolving unit rotatably mounted on the lower traveling unit, and a work attachment including a boom, an arm, and a bucket rotatably mounted on the upper revolving unit. In the hydraulic excavator, the boom angle, arm angle, and bucket angle at each node of the work attachment and the swing angle of the upper swing body are detected. When the upper swing body swings, the bucket and the lower traveling body may interfere with each other. An interference danger area and a turning prohibition angle at which the bucket and the lower traveling body do not interfere with each other while the upper swing body is stopped even within this interference danger area are set, and the bucket turns while the upper swing body is swinging or stopped. If it is not within the prohibited angle, set the boom limit angle, arm limit angle and bucket limit angle when the bucket contacts the interference danger area, When the angle of the work attachment approaches these limit angles, the work attachment system control that reduces the control signal of each actuator of the work attachment and stops the work attachment prevents the undercarriage from interfering with the bucket, while When the bucket is in the turning prohibition angle while being stopped, the work attachment system control is canceled and the lower traveling body is controlled by the turning system control that controls the turning actuator so that the upper turning body cannot turn. A method for preventing interference with a work attachment in a hydraulic excavator, characterized by preventing interference with a bucket.