JP3466371B2 - Construction machine interference prevention equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an interference prevention device for a construction machine equipped with an articulated front device, and more particularly,
The present invention relates to an interference prevention device that prevents interference between a front device and a cab (driver's cab) in a hydraulic excavator including a front device such as an arm, a boom, a bucket, and an offset.

[0002]

2. Description of the Related Art In a hydraulic excavator, an operator operates a front member such as a boom with respective manual operation levers. However, in order to widen the excavation range, a front device having an offset interferes with the cab depending on the posture. There is a risk of

Therefore, an interference prevention device for preventing such interference is described in Japanese Patent Application Laid-Open No. 3-217523 and Japanese Patent Publication No. 6-104985.

According to the proposal of Japanese Patent Laid-Open No. 3-217523, when the front end of the front device moves to the cab side more than the faces set on the front side, upper side and side face side of the cab, By stopping the operation, interference between the front device and the cab can be prevented.

According to the proposal of Japanese Patent Publication No. 6-104985, the front end of the front device is located on the front side of the cab.
By controlling the actuator so that the front device separates (returns) from the cab when it moves to the cab side from the surface set on the upper side and the side surface side,
Interference between the front device and the cab can be prevented.

[0006]

However, the above-mentioned prior art has the following problems. JP-A-3-2175
In the conventional technique described in Japanese Patent Laid-Open No. 23-23, since all the actuators stop within the setting plane for preventing interference, continuous excavation operations cannot be performed near the cab, resulting in a significant decrease in work efficiency.

Further, in the prior art disclosed in Japanese Examined Patent Publication No. 6-104985, feedback control is performed to detect that the front device has reached the setting surface and control so that the front device returns to the setting surface. Invasion to some extent is inevitable. Therefore, it is necessary to set the setting surface far away from the cab in consideration of the amount of intrusion,
The work range becomes narrow. Further, after the front device returns to the outside of the setting surface, the operation of moving again in the cab direction is repeated, and the movement of the front device becomes jerky.

Further, in the above-mentioned conventional technique, the operation control of the front device is performed without considering the change of the state quantity which affects the operation characteristic of the front device, for example, the change of the boom angle. Therefore, the response to the feedback value deviates from the optimum due to the change in the state quantity,
May cause hunting.

[0009] The first object of the present invention, the front device and luck
It is possible to continuously move the front device while preventing interference with the vehicle body part other than the cab or the driver's cab .
An object of the present invention is to provide an interference prevention device for a construction machine that can secure a wide working range.

A second object of the present invention is to continuously operate the front device while preventing interference between the front device and the cab without causing hunting even if the state quantity affecting the operating characteristics of the front device changes. It is an object of the present invention to provide an interference prevention device for a construction machine that can be moved to the right.

[0011]

Means for Solving the Problems (1) First and Second Above
In order to achieve the object of the present invention, the present invention drives a front device including a plurality of front members including first and second front members that can rotate in the vertical and horizontal directions, and the front members. Multiple hydraulic actuators,
A plurality of operation means for instructing the operation of the plurality of front members, and a plurality of flow rate control valves for controlling the flow rate of the pressure oil supplied to the corresponding hydraulic actuators in accordance with the operation signals of the plurality of operation means. Is installed in a construction machine having the following: calculates the position and orientation of the front device, and based on this position and orientation, the front device operates in the cab or
In an interference prevention device that controls so as not to enter a preset interference prevention area around the vehicle body part other than the room ,
(A) The distance from the front device to the interference prevention area is calculated based on the position and orientation of the front device, and when the distance becomes equal to or less than a preset control start distance, the first
Operation of the first front member to decelerate the front member
Correcting the operation signals work unit, and the corrected operation signal
From the front device to the interference prevention area
First correction means for correcting the operation signal of the operation means of the second front member so as to increase the speed of the second front member in the interference avoidance direction of the interference prevention region according to the distance;
Detection means for detecting a state quantity that affects the operating characteristics of the front device; and (c) control for increasing the speed of the second front member in the first correction means according to the state quantity detected by the detection means. A second correction means for correcting the gain is provided.

As described above, the first correcting means is provided, and when the distance from the front device to the interference prevention area becomes smaller than the preset control start distance, the first front member is decelerated.
To correct the operation signal of the operation means of the first front member
In addition, the command value of this corrected operation signal and the front
By correcting the operation signal of the operating means placed al cormorants by the second front member is increased to interference avoiding direction according to the distance to the interference prevention area second front member, the front device approaches the interference prevention area While gradually decelerating, it moves along the vicinity of the boundary of the interference prevention area, and the front device can be continuously moved while preventing the interference between the front device and the driver's cab or a vehicle body part other than the driver's cab .

Further, the command value of the corrected operation signal and the flow
The second front member is accelerated in the interference avoidance direction of the interference prevention region according to the distance from the front device to the interference prevention region, so that the movement of the front device is predicted from the operation of the first front member and the front device prevents the interference. It is possible to perform an interference avoidance operation in predictive control, in which an interference avoidance operation is performed before entering an area, and thus the amount of entry into the interference prevention area can be set to 0 or minimized, so that the interference prevention area can be narrowed and a wide working range can be achieved. Can be secured.

Further, in a hydraulic construction machine such as a hydraulic excavator, when the state quantity such as the boom angle changes, the operation characteristics of the front device change, and the deceleration ratio of the first front member and the deceleration ratio of the first front member during the deceleration / interference avoidance operation. The accelerating rate of the second front member may not be optimal, and a hunting phenomenon may occur.

According to the present invention, the state quantity which affects the operation characteristics of the front device is detected as described above, and the second correction means determines the acceleration of the second front member in the first correction means according to the state quantity. Correct the control gain. As a result, even if the state quantity such as the boom angle changes, the deceleration rate of the first front member and the acceleration rate of the second front member can always be optimized, and hunting can be prevented.

(2) In the above item (1), for example, the state quantity is an operating angle of the first front member, and the second correcting means is configured to increase the operating angle of the first front member by increasing the first angle. It is corrected so that the control gain for increasing the speed of the second front member in the correction means becomes large.

(3) Further, in the above (1), for example, the state quantity is a load pressure of the hydraulic actuator of the first front member, and the second correcting means sets the first pressure as the load pressure increases. Second in the correction means
Correction is performed so that the control gain for increasing the speed of the front member is reduced.

(4) Further, in the above-mentioned (1), for example, the state quantity is an oil temperature, and the second correction means is the second in the first correction means as the oil temperature becomes lower.
Correction is performed so that the control gain for increasing the speed of the front member is reduced.

(5) Further, in the above (1), for example, the state quantity is a rotation speed of a prime mover for driving the hydraulic pump, and the second correction means makes the first correction as the rotation speed increases. The control gain for increasing the speed of the second front member in the means is corrected to be small.

(6) Further, in the above (1), preferably, the first correcting means (a1) sets a maximum value when the distance from the front device to the interference prevention area is larger than the control start distance. The first limit value of the operation signal of the first front member is calculated, which becomes smaller as the distance becomes smaller than the control start distance and becomes smaller as the distance becomes smaller, and becomes 0 as the distance becomes smaller than a certain negative value. And (a2) the maximum value is maintained when the distance from the front device to the interference prevention area is larger than the control start distance, and when the distance becomes equal to or smaller than the control start distance, the distance decreases as the distance decreases, Second calculating means for calculating a second limit value of the operation signal of the second front member, which becomes 0 when the distance becomes 0 and becomes smaller when the distance becomes a negative value, a3) When the distance from the front device to the interference prevention area is larger than the control start distance, 0 is maintained, and when the distance becomes equal to or shorter than the control start distance, the distance becomes smaller and the distance becomes 0 or smaller. Third calculating means for calculating a control gain for increasing the speed of the second front member so as to have a maximum value, and (a4) correcting the operation signal of the operating means for the first front member so as not to exceed the first limit value. First signal correction means for
5) Based on the correction operation signal corrected by the first signal correction means and the control gain calculated by the third calculation means,
Fourth calculating means for calculating a speed-up command value in the interference avoiding direction with respect to the interference prevention region of the second front member;
6) The operation signal of the operating means of the second front member is corrected using the second limit value calculated by the second calculating means and the acceleration command value in the interference avoidance direction calculated by the fourth calculating means. The second correction means corrects the change rate of the control gain calculated by the third calculation means with respect to the distance according to the state quantity.

The first calculation means calculates the first limit value so that the distance becomes 0 when the distance becomes a negative value or less as described above, and the first signal correction means makes the first limit value not exceed the first limit value. By correcting the operation signal of the operation means of the front member, even if the front device reaches the interference prevention area, the first front member is decelerated without stopping the first front member. The above deceleration / interference avoidance operation can be performed in a state where the boundary is closest to the boundary of the interference prevention area.

The second calculating means calculates the second limit value so that when the distance becomes a negative value as described above, the second limit value becomes smaller according to the negative value, and the second signal correcting means uses the second limit value. By correcting the operation signal of the operating means of the second front member by operating the second front member, the second front member is gradually decelerated as the front device approaches the interference prevention region when the second front member is operated. When the front device intrudes into the interference prevention area, the second front member is controlled to return and the front device is retracted from the interference prevention area, so that the second front member can be safely operated. You can

Based on the correction operation signal corrected by the first signal correcting means by the fourth calculating means and the control gain calculated by the third calculating means, the speed increasing command value in the interference avoiding direction of the second front member is calculated. The operation of the first front member is calculated so that the front device does not enter the interference prevention area by calculating and correcting the operation signal of the operation means of the second front member by using the speed-up command value by the second signal correction means. Accordingly, the second front member speeds up in the interference avoidance direction.

The second correction means corrects the rate of change of the control gain calculated by the third calculation means with respect to the distance according to the state quantity, so that the second front according to the state quantity as described in (1) above. The control gain for increasing the speed of the member is corrected.

(7) In above (6), preferably,
The second correction unit corrects the change rate of the control gain with respect to the distance by changing the maximum value of the control gain calculated by the third calculation unit according to the state quantity.

(8) In the above (6), the second correcting means changes the control gain with respect to the distance by changing the increase start distance of the control gain calculated by the third computing means according to the state quantity. By correcting the ratio and changing the decrease start distance of the first and second limit values calculated by the first and second calculating means to be the same as the increase start distance of the control gain, the first and second limit values are changed. The rate of change of the two limit values with respect to the distance may be corrected.

(9) Further, in the above (6), preferably, the fourth arithmetic means has a correction operation signal corrected by the first signal correcting means and a control gain calculated by the third arithmetic means. Is a means for multiplying, and this multiplication value is used as the acceleration command value in the interference avoidance direction.

(10) Further, in the above (6), preferably, the second signal correction means subtracts the speed-up command value in the interference avoidance direction from the second limit value, and exceeds the subtracted value. The operation signal of the operation means of the second front member is corrected so that it does not exist.

(11) Further, in the above item (6), for example, the plurality of operating means is an electric lever system that outputs an electric signal as the operation signal, and the first signal correcting means is the first front member. Of the operation signal of the operating means and the first limit value, whichever is smaller, is output to the flow rate control valve of the first front member as the command signal, and the second signal correcting means is used for the second signal correcting means. The smaller one of the operation signal of the operating means of the front member and the speed-up command value in the interference avoidance direction is selected, and the selected value is output as a command signal to the flow control valve of the second front member.

(12) In the above (11), preferably, the fourth computing means uses a command signal output to the flow control valve of the first front member as the correction operation signal to increase the interference avoiding direction. Calculate the speed command value.

(13) Further, in the above (6), the plurality of operating means may be a hydraulic pilot system which outputs a pilot pressure as the operating signal. In this case, the first signal correcting means is: A proportional electromagnetic pressure reducing valve that is arranged in a path for guiding the pilot pressure of the operating means of the first front member to the flow control valve of the first front member and that reduces the pilot pressure according to the first limit value; The two-signal correction means outputs the pilot pressure according to the speed-up command value in the interference avoiding direction to the proportional electromagnetic pressure reducing valve and the pilot pressure from the operating means of the second front member to the flow control valve of the second front member. It includes a shuttle valve that is arranged in the leading path and that selects the pilot pressure of the proportional electromagnetic pressure reducing valve or the pilot pressure of the operating means of the second front member, whichever is higher.

(14) In the above item (11), preferably, the device further comprises means for detecting a pilot pressure of the operating means of the first front member, and the fourth computing means includes the detected value of the pilot pressure and the first value. The smaller one of the limit values is selected, and the selected value is used as the correction operation signal to calculate the acceleration command value in the interference avoidance direction.

(15) In the above (1) to (14), for example, the first front member is a boom of a hydraulic excavator, the second front member is an arm of a hydraulic excavator, and the signal correcting means is used. The operation signal of the first front member corrected by is an operation signal in the raising direction of the boom, and the operation signal of the second front member is an operation signal in the dumping direction of the arm.

[0034]

BEST MODE FOR CARRYING OUT THE INVENTION A first embodiment of the present invention will be described below with reference to FIGS. 1, a hydraulic excavator to which the present invention is applied includes a hydraulic pump 2 and a boom cylinder 3 driven by pressure oil from the hydraulic pump 2.
a, an arm cylinder 3b, a bucket cylinder 3c, an offset cylinder 3d, a swing motor 3e, and left and right traveling motors 3f and 3g, and operating levers provided corresponding to the hydraulic actuators 3a to 3g, respectively. Devices 4a to 4g and hydraulic pump 2
Is connected between a plurality of hydraulic actuators 3a to 3g,
The hydraulic drive device includes a plurality of flow rate control valves 5a to 5g that are controlled by the operation signals of the operation lever devices 4a to 4g and that control the flow rate of the pressure oil supplied to the hydraulic actuators 3a to 3g.

The hydraulic excavator, as shown in FIGS. 2 and 3, has a multi-joint type front device 1A consisting of a boom 1a, an arm 1b, a bucket 1c and an offset 1d which rotate in the vertical direction, and an upper swivel device. The vehicle body 1B is composed of a body 1e and a lower traveling body 1f, and the base end of the boom 1a of the front device 1A is supported by the front portion of the upper swing body 1e. Boom 1a, arm 1b, bucket 1
c, offset 1d, upper swing body 1e, and lower traveling body 1
f is a boom cylinder 3a and an arm cylinder 3 respectively
b, bucket cylinder 3c, offset cylinder 3d,
The swing motor 3e and the left and right traveling motors 3f and 3g are respectively driven, and their operations are instructed by the operation lever devices 4a to 4g.

The upper swing body 1e has a cab 3h as a driver's seat operated by an operator.

Returning to FIG. 1, the operation lever devices 4a to 4g are electric lever systems which drive the corresponding flow rate control valves 5a to 5g according to the operation amount, and the operation amounts of the operation levers 4a to 4g respectively operated by the operator. And a current corresponding to the operation direction are supplied to the electromagnetic drive units 20a of the corresponding flow control valves.
26b.

The above-described hydraulic excavator is provided with the interference prevention device according to this embodiment. This interference prevention device is provided at each of the rotation fulcrums of the boom 1a, the arm 1b, and the offset 1d, and angle detectors 6a and 6b that detect the respective rotation angles as state quantities related to the position and orientation of the front device 1A, 6c and angle detectors 6a, 6b,
6c and the control lever device 4a to 4g, and a control unit 7 that outputs an electric signal for performing interference prevention control.

The control function of the control unit 7 is shown in FIG.
The control unit 7 includes a front attitude calculation unit 7a, input limit value calculation units 7b to 7d, maximum / minimum value selection units 7e to 7g for limiting the input, a control gain calculation unit 7h, a multiplication unit 7i, and addition. The unit 7j, the detection line 7m, and the respective calculation units 30a to 36b of the command value to the flow control valve corresponding to the expansion side and the contraction side of each actuator are provided.

In the front attitude calculation unit 7a, the rotation angles of the boom, arm and offset detected by the angle detectors 6a to 6c are input, and based on these rotation angles, coordinate conversion is performed to convert the tip position of the front device 1A ( Monitor point)
And the distance r from the tip position to the interference prevention area
Is calculated. At this time, as shown in FIGS. 5 and 6, the interference prevention area is a safe distance around the cab 3h, for example, 3
It is set at 0 cm. Further, as the tip position of the front device 1A, the rotation fulcrum Ov of the bucket 1c is
The position of the point closest to the boundary of the interference prevention area on the virtual circle X of radius rv to the tip P of the bucket 1c centered at is calculated, and the distance r from this point to the interference prevention area is calculated.

The input limit value calculators 7b to 7d calculate the input limit value u based on the distance r obtained as described above and a preset deceleration control calculation formula.

Here, in the calculation unit 7d with the offset 1d, the limit value u maintains the maximum value when the distance r is larger than the control start distance r0, and when the distance r becomes the control start distance r0 or less, the distance r becomes small. As the limit value u decreases, the relationship between the distance r and the limit value u is set such that the limit value u becomes 0 when the distance r becomes 0 or less. The offset 1d is stopped as 0.

On the other hand, in the calculation unit 7b of the boom 1a, when the distance r is larger than the control start distance r0, the limit value u maintains the maximum value, and when the distance r becomes the control start distance r0 or less,
The limit value u becomes smaller as the distance r becomes smaller, and the relation between the distance r and the limit value u is set so that the limit value u becomes 0 when the distance r becomes a negative value rn or less. The limit value u on the boundary is set to be larger than 0 to enable the boom 1a to operate.

In the calculation unit 7c of the arm 1b, when the distance r is larger than the control start distance r0, the limit value u maintains the maximum value, and when the distance r becomes the control start distance r0 or less,
The limit value u becomes smaller as the distance r becomes smaller, the limit value u becomes 0 when the distance r becomes 0, and the limit value u becomes smaller according to the negative value when the distance r becomes a negative value. A relation between r and the limit value u is set, whereby the limit value u is set to 0 on the boundary of the interference prevention region, and when the arm 1b enters the interference prevention region, the limit value u is set to (−), and the reverse direction is set. It is designed to move in the arm dump direction.

In the calculation units 7b to 7d, the maximum value of the limit value u is set to a value that substantially coincides with the maximum value of the operation signal of the operation lever devices 4a, 4b, 4d.

In the maximum / minimum value selectors 7e-7g, the input signals from the operating lever devices 4a, 4b, 4d are compared with the input limit value u, and the signal is selected so that the input signal does not exceed the limit value u. I do.

In the operation parts 30a to 36b of the command values to the pressure reducing valves corresponding to the expansion side and the contraction side of each actuator, when the input sign is positive, the expansion side electromagnetic drive parts 20a to 2b are used.
In 6a, when the sign of the input is negative, the command value is calculated so as to excite the contraction side electromagnetic drive units 20b to 26b. Here, in the minimum value selection units 7e to 7g, the calculation units 7b to 7g.
When the limit value u calculated in d is selected, the calculation unit 30
The command value calculated by a, 31a, and 33b becomes a deceleration command value.

The control gain calculator 7h calculates the control gain K based on the distance r to the interference prevention area and a preset calculation formula. Here, when the distance r is larger than the control start distance r0, the control unit 7h sets the control gain K to 0.
When the distance r becomes equal to or less than the control start distance r0, the control gain K increases as the distance r decreases, and when the distance r becomes 0 or less, the control gain K becomes the maximum constant value and the control is performed. The relationship with the gain K is set.

Further, the control gain calculator 7h is used as a state quantity that influences the operating characteristics of the front device 1A, particularly the operating characteristics when performing the deceleration / interference avoiding operation (described later) of the front device relating to the control of the present invention. The signal from the angle detector 6a that detects the rotation angle of the boom 1a (hereinafter referred to as the boom angle α) is input, and the control gain K is corrected so as to increase as the boom angle α increases.

FIG. 7 shows details of the control gain calculator 7h. The control gain calculator 7h has the functions of a function generator 70h, a function generator 71h, and a multiplier 72h. The function generator 70h calculates a basic control gain Ko according to the distance r from the front device tip to the interference prevention area. Here, the relationship between the distance r and the basic control gain Ko is that the gain Ko is 0 when the front device tip is away from the interference prevention region and the distance r is large, and the front device tip approaches the interference prevention region r and the distance r is The gain Ko is set to increase as it approaches zero. On the other hand, the function generator 71h calculates the correction coefficient K1 according to the boom angle α. Here, the relationship between the boom angle α and the correction coefficient K1 is set such that the correction coefficient K1 is 1 when the boom angle α is small, and the correction coefficient K1 increases as the boom angle α increases. The multiplier 72h multiplies the basic control gain Ko obtained by the function generator 70h by the correction coefficient K1 obtained by the function generator 71h to obtain the control gain K. As a result, the control gain calculator 7
In h, the control gain K is corrected so that the change rate (gradient of the function) of the control gain K with respect to the distance r increases and the maximum value of the control gain K increases as the boom angle α increases.

In the detection line 7m, the command value calculation unit 30a
The command value on the boom raising side calculated in step 3 is taken out and supplied to the multiplication unit 7i.

The multiplication unit 7i obtains the product of the control gain K and the command value on the boom raising side extracted by the detection line 7m. The value obtained here is a speed increase command value in the interference avoidance direction (interference avoidance target speed) as described later.

The adder 7j calculates the difference between the limit value of the arm input and the product of the control gain K and the command value on the boom raising side.

In the above, the operation lever devices 4a, 4
b, 4c, and 4d constitute a plurality of operating means for instructing the operation of a boom, an arm, a bucket, and an offset, which are a plurality of front members, and when the boom 1a and the arm 1b are the first and second front members, respectively, Angle detector 6a
6c, operation units 7a to 7c, selection units 7e and 7f, operation unit 7h, multiplication unit 7i, addition unit 7j, operation units 30a to 31.
b, the electromagnetic drive units 20a to 21b calculate a distance r from the front device to the interference prevention area based on the position and orientation of the front device 1A, and when the distance r becomes smaller than a preset control start distance r0, The first front member 1a is decelerated and the second front member 1b is accelerated in the interference avoidance direction in response to the operation of the first front member 1a.
And operating means 4a, 4b for the second front members 1a, 1b
Of the operation signal, the angle detector 6a constitutes a detecting means for detecting a state quantity that influences the operating characteristics of the front device 1A, and the control gain computing section 7
The function generator 71 of h and the multiplication unit 72h are second correction means for correcting the control gain K for increasing the speed of the second front member 1b in the first correction means in accordance with the state quantity detected by the detection means. Make up.

The operation of this embodiment configured as described above will be described. As an example of the work, (a) the arm 1b is operated toward the front (rear) so that the front device 1A approaches from the front of the cab 3h, (b) the boom 1a is operated upward, and (c) the boom. When the arm 1b is operated to the front (rear) while operating the 1a upward, (d)
A case where the offset 1d is operated to the left will be described.

(A) First, when the arm 1b is operated to the front (backward, that is, in the arm cloud direction), when the tip of the front device 1A approaches the interference prevention area and the distance r becomes smaller than the control start distance r0, Limit value calculation unit 7c
The arm cylinder 3b according to the limit value u calculated by
The command value on the extension side of is limited, and a deceleration command for the arm 1b is issued. Thereby, the arm 1b is gradually decelerated and stopped at the boundary L of the interference prevention area.

Further, in the unlikely event that the front end of the front device enters the interference prevention area, the limit value u of the limit value calculation unit 7c will be used.
Becomes (-), and the command value on the contraction side of the arm cylinder 3b is forcibly increased, whereby the speed of the arm 1b is increased forward (in the arm dump direction), and the front end of the front device is retracted from the interference prevention area. Therefore, the operator can safely operate the arm 1b without worrying about the interference between the front device 1A and the cab 3h.

(B) When the boom 1a is operated upward, when the tip of the front device 1A approaches the interference prevention region and the distance r becomes smaller than the control start distance r0, the limit value calculation unit 7b calculates it. The command value on the extension side of the boom cylinder 3a is limited according to the limit value u
A deceleration command for "a" is issued, whereby the boom 1a is gradually decelerated. At the same time, a command value in the arm dump direction proportional to the extension side command value of the boom cylinder 3a is calculated as a speed increase command value in the interference avoidance direction by the detection line 7m, the control gain calculation unit 7h, and the multiplication unit 7i. The speed-up command value in the avoidance direction is larger than the limit value u calculated by the limit value calculation unit 7c, and the limit value u is added by the addition unit 7j.
When the value obtained by subtracting the speed increase command value in the interference avoidance direction from (-) becomes (-), the speed increase command value in the interference avoidance direction becomes the arm cylinder 3
The signal is output to the contracted side of b, and the arm 1b is accelerated in the interference avoiding direction to perform the interference avoiding operation on the interference preventing area. Due to such deceleration of the boom 1a and operation of the arm 1b in the interference avoidance direction, the front end of the front device 1A is indicated by an arrow M in FIG.
As shown in, the operation along the boundary L is performed in the vicinity of the boundary L of the interference prevention area. Therefore, the continuous boom 1a can be safely operated without worrying about the interference between the front device 1A and the cab 3h.

(C) When the arm 1b is operated to the front (rear) while the boom 1a is operated upward, when the distance r becomes smaller than the control start distance r0, the boom cylinder 3a is moved as shown in (b) above. The extension side command value is limited, and the boom 1a is gradually decelerated. At the same time, the multiplication unit 7i calculates a command value in the arm dump direction (a speed increase command value in the interference avoidance direction) proportional to the extension side command value of the boom cylinder 3a. On the other hand, when the value obtained by subtracting the speed increase command value in the interference avoidance direction from the limit value u calculated by the limit value calculation unit 7c is (+), the command value on the extension side of the arm cylinder 3b is limited according to the value. When the value becomes (-), the value is output as a command value to the contraction side of the arm cylinder 3b, and the arm 1b is accelerated in the interference avoiding direction,
The arm 1b performs an interference avoiding operation on the interference prevention area. Again, as a result of the composite of such behaviors,
As shown by the arrow M in FIG. 5, the front end of the front device 1A performs an operation along the boundary L in the vicinity of the boundary L of the interference prevention region without worrying about the interference between the front device 1A and the cab 3h. The continuous boom 1a can be safely operated.

(D) When the offset 1d is operated to the left, when the tip of the front device 1A approaches the interference prevention area and the distance r becomes smaller than the control start distance r0, the limit value calculation unit 7d calculates. The command value on the compression side of the offset cylinder 3d is limited according to the limit value u, and the deceleration command for the offset 1d is issued. As a result, the offset 1d is gradually decelerated and stopped at the boundary L of the interference prevention region. Therefore, the offset 1d can be safely operated without worrying about the interference between the front device 1A and the cab 3h.

Here, the operation characteristics of the front device 1A, particularly the operation characteristics when the deceleration / interference avoidance operation (described later) of the front device is performed as described above, vary depending on the boom angle α.

FIG. 8 shows changes in operating characteristics of the front device depending on the boom angle α. In FIG. 8, is the posture of the front device when the boom angle α is small and the front device tip is located near the cab interference prevention region boundary, and is when the boom angle α is large the front device tip is near the cab interference prevention region boundary. The posture of the front device 1A located at. Further, the vectors V1 and V2 are the tip speeds of the front device 1A given by the rotation of the boom 1a in the respective postures. As can be seen from this drawing, even if the magnitudes of the velocity vectors V1 and V2 are the same as the posture, the horizontal component of the velocity vectors V1 and V2, that is, the cab interference prevention region boundary due to the rotation of the boom 1a. The speed at which the front end of the front device enters in the cab direction in the vicinity is different from v1h <v2h. Therefore, when performing the deceleration / interference avoidance operation of the front device in the above (b), it is necessary to move the arm forward at a speed faster than the attitude.

By the way, when the operator operates the boom 1a in the raising direction while the front device 1A is in the posture, the front end of the front device tries to exceed the cab interference prevention region. At this time, in the control of (b) of the present invention, the arm 1b is automatically moved forward (in the dumping direction) so that the tip of the front device does not enter the cab interference prevention region, and the interference avoidance operation is performed. This causes the tip of the arm to rise almost along the boundary of the cab interference prevention region. At this time, it is desirable to balance the boom raising and the forward movement of the arm and smoothly raise the arm tip.

That is, in order to realize the above-mentioned interference avoiding operation, in the control of the present invention, the position of the front end of the front device and the cab are always detected from the signals of the angle detectors 6a-6c attached to the front device 1A as described above. The distance r to the interference prevention area is calculated (FIG. 4, calculation unit 7a). Then, using the distance r as a feedback value, the forward command value of the arm 1b is calculated while reducing the raising speed of the boom 1a (FIG. 3, calculation unit 7b) (FIG. 3, calculation unit 7h, multiplication unit 7).
i, the addition unit 7j) and the arm 1b are automatically moved forward.

From this fact, the degree of deceleration of raising the boom 1a with respect to the feedback value r (the rate of change of the limit value u with respect to the distance r in the calculation unit 7b, that is, the slope (gain) of the function), and the arm 1b with respect to the feedback value r. It is necessary to keep a balance with the forward acceleration rate (change rate of the control gain K in the calculation unit 7h with respect to the distance r, that is, the slope (gain) of the function of).

Therefore, in the posture shown in FIG. 8, the slope (gain) of the function of the calculation unit 7b and the slope (gain) of the function of the calculation unit 7h (in order to balance the degree of deceleration of the boom raising and the forward acceleration of the arm) are balanced. Gain is set. However, in the posture shown in FIG. 8, the speed v2h at which the tip of the front device enters in the cab direction is higher than the speed v1h of the posture as described above, and it is necessary to move the arm forward at a speed faster than the posture. The degree is insufficient, and the acceleration of the arm 1b toward the front is insufficient. Therefore, when the boom 1a is raised, the front end of the front device enters the cab interference prevention area at a speed at which the arm 1 moves.
The forward speed increasing operation of b does not catch up, the front end of the front device crosses the boundary of the interference prevention region, and u = of the calculation unit 7b in FIG.
The boom 1a stops until it reaches 0, and the boom 1a stops at this position. Then, thereafter, the arm 1b gradually moves forward and the front end of the front device returns to the outside of the interference prevention area. Then, the boom 1a starts moving upward again, the front end of the front device enters the interference prevention region, and the boom 1a stops again at the position where u = 0. This may be repeated to cause a hunting phenomenon.

Even when the arm 1b is operated forward (rearward) while operating the boom 1a in the above (c), the boom is stopped and the arm is moved forward as in the case of the above (b). May cause repeated hunting.

Therefore, in the present embodiment, the boom angle α is detected and is corrected so that the rate of change of the control gain K with respect to the distance r (the slope of the function) increases as the boom angle α increases. As a result, the boom 1 of (b) above is
When a is operated upward, the command value for acceleration calculated by the multiplication unit 7i increases as the boom angle α increases, and the forward operation speed of the arm 1b increases.
As a result, the arm can be released forward at an optimum speed according to the boom angle α, and the hunting can be prevented.

The same applies to the above case (c).

As described above, according to this embodiment, when the boom 1a is operated upward, or when the arm 1b is operated forward (rearward) while operating the boom 1a upward, the front device 1A is When the vehicle approaches the interference prevention area, it will gradually decelerate, and when it reaches the interference prevention area, it will move along the boundary of the interference prevention area and continuously move the front equipment while preventing the interference between the front equipment and the cab. You can Therefore, even near the cab 3h, it is possible to continuously lift the sand without stopping.

Further, since the movement of the front device 1A is predicted from the operation of the boom 1a and the interference avoiding operation is performed before the front device enters the interference prevention area, the amount of entry into the interference prevention area can be set to 0 or minimized. Since the interference prevention area can be narrowed, a wide working range can be secured.

When the arm 1b is operated to the front (rear), the arm is gradually decelerated as the front device tip approaches the interference prevention area, and the boundary L of the interference prevention area is increased.
If the front end of the front device enters the interference prevention area, the arm is accelerated forward,
Since the front end is retracted from the interference prevention area, the arm can be operated safely.

Further, when the offset 1d is operated to the left, the offset is gradually decelerated as the front device tip approaches the interference prevention area, and the boundary L of the interference prevention area is increased.
Since it stops at, you can safely operate the offset as well.

Further, according to the present embodiment, the boom angle α
Even when the change occurs, it is possible to prevent the front end of the front device 1A from entering the interference prevention area during the above-described deceleration / interference avoidance operation of the boom and arm, and hunting due to the entry.

The second embodiment of the present invention is shown in FIGS. 9 and 10.
Will be described. The present embodiment is applied to a hydraulic excavator using a hydraulic pilot system as an operating lever device. In the figure, the same members and parts as those shown in the above drawings are designated by the same reference numerals.

In FIG. 9, the hydraulic excavator to which the present embodiment is applied has hydraulic pilot type operation lever devices 9a to 9g instead of the electric type operation lever devices 4a to 4g.
g. The operation lever devices 9a to 9g are respectively operated by the operator based on the pilot pressure generated by the pilot pump 8.
The pilot pressure corresponding to the operation amount and the operation direction of ˜9 g is supplied to the hydraulic drive units 50a to 56b of the corresponding flow control valves via the pilot lines 40a to 46b, and the flow control valves 10a corresponding to the pilot pressures are supplied by the pilot pressures. Drive 10g.

The hydraulic excavator as described above is provided with the interference prevention device according to the present embodiment. This interference prevention device is provided in the pilot line 40a of the boom operation lever device 9a in addition to that provided in the first embodiment, and is a pressure detector that detects pilot pressure as the operation amount of the operation lever 9a. 13, a proportional electromagnetic pressure reducing valve 11a to 11d driven by an electric signal, and a shuttle valve 12 are provided. Proportional electromagnetic pressure reducing valves 11a, 11b, 11
d are pilot lines 40a, 41a, 43b, respectively
Is installed in the hydraulic drive unit 5 of the flow control valves 10a, 10b, 10d by reducing the pilot pressure according to an electric signal.
It outputs to 0a, 51a, 53b. Proportional solenoid pressure reducing valve 11
c is installed in a dedicated pilot line 41c connected to the pilot pump 8, and the shuttle valve 12 is a pilot pressure in the pilot line 41b and a proportional electromagnetic pressure reducing valve 11c.
Select the high pressure side of the control pressure output from the flow control valve 1
0b to the hydraulic drive unit 51b.

Differences in control function from the first embodiment will be described with reference to FIG.

In the original hydraulic pilot type hydraulic excavator without the interference prevention device, the operation lever devices 9a to 9a.
Flow control valve 10 with pilot pressure adjusted at 9 g
Since a to 10 g are directly driven, it is not necessary to use anything other than the arm as a calculation unit of the command value to the pressure reducing valve corresponding to the expansion side and the contraction side.

Further, due to the characteristics of the proportional electromagnetic pressure reducing valves 11a to 11d and the shuttle valve 12, a maximum / minimum value selection unit for limiting the input is not required. Instead, the boom pressure is increased from the pilot pressure in the pilot line 40a. In order to estimate the pilot pressure acting on the (expansion) side hydraulic drive unit 50a, the smaller one of the output of the pressure detector 13 that detects the pilot pressure as the operation amount of the operation lever 9a and the output of the limit value calculation unit 7b is selected. A selecting unit 7k for selecting is added. Although the pressure detector 13 may be provided on the outlet side of the proportional solenoid pressure reducing valve 11a and the detected value may be used directly, it is better to detect on the inlet side of the proportional solenoid pressure reducing valve 11a in terms of responsiveness. There is.

As described above, when the boom 1a and the arm 1b are the first and second front members, respectively, as in the first embodiment, the angle detectors 6a to 6c, the pressure detector 13, the calculation units 7a to 7c, The selecting unit 7k, the calculating unit 7h, the multiplying unit 7i, the adding unit 7j, the calculating units 31a and 31b, and the proportional solenoid valve pressure valves 11a to 11c are based on the position and the posture of the front device 1A and the distance r from the front device to the interference prevention area. Is calculated, and the distance r is set to a preset control start distance r
When it is smaller than 0, the first and second front members 1a, 1b are decelerated and the second front member 1b is accelerated in the interference avoiding direction in accordance with the operation of the first front member. The angle detector 6a constitutes a first correcting means for correcting the operation signals of the operating means 4a and 4b, the angle detector 6a constitutes a detecting means for detecting a state quantity which affects the operation characteristics of the front device 1A, and the control gain computing section 7h. The function generator 71 and the multiplication unit 72h (see FIG. 7) correct the control gain K for increasing the speed of the second front member 1b in the first correction unit according to the state quantity detected by the detection unit. It constitutes a second correction means.

The operation of this embodiment configured as described above will be described.

(A) When the arm 1b is operated to the front (backward, that is, the arm cloud direction), when the tip of the front device 1A approaches the interference prevention area and the distance r becomes smaller than the control start distance r0, the limit value is reached. The proportional electromagnetic pressure reducing valve 11b limits the pilot pressure on the extension side of the arm cylinder 3b according to the limit value u calculated by the calculation unit 7c, and issues a deceleration command for the arm 1b. Thereby, the arm 1b is gradually decelerated and stopped at the boundary L of the interference prevention area.

Further, in the unlikely event that the front end of the front device enters the interference prevention area, the limit value u of the limit value calculation unit 7c will be used.
Becomes (-), the proportional electromagnetic pressure reducing valve 11c operates, and the pilot pressure on the contracting side of the arm cylinder 3b is forcibly increased, whereby the arm 1b is accelerated forward (arm dumping direction), and the front device The tip of 1A is retracted from the interference prevention area. Therefore, the operator is
The arm 1b can be safely operated without worrying about the interference between A and the cab 3h.

(B) Further, when the boom 1a is operated upward, when the tip of the front device 1A approaches the interference prevention area and the distance r becomes smaller than the control start distance r0, the limit value calculation unit 7b calculates it. The pilot pressure on the extension side of the boom cylinder 3a is limited by the proportional electromagnetic pressure reducing valve 11a according to the limit value u, and a deceleration command for the boom 1a is issued, whereby the boom 1a is gradually decelerated. At the same time, the detection line 7m, the control gain calculation unit 7h, and the multiplication unit 7i calculate a speed increasing command value in the interference avoiding direction that is proportional to the expansion side pilot pressure of the boom cylinder 3a. When the value is larger than the limit value u calculated by the limit value calculation unit 7c and the value obtained by subtracting the speed increase command value in the interference avoidance direction from the limit value u in the addition unit 7j becomes (-), the interference avoidance direction Is output to the contraction side of the arm cylinder 3b, and the arm 1b is accelerated in the interference avoidance direction to perform the interference avoidance operation in the interference prevention area. By such deceleration of the boom 1a and operation of the arm 1b in the interference avoidance direction, the tip of the front device 1A is
As shown by an arrow M in FIG. 5, the operation along the boundary L is performed in the vicinity of the boundary L of the interference prevention region. Therefore, the continuous boom 1a can be safely operated without worrying about the interference between the front device 1A and the cab 3h.

(C) When the arm 1b is operated to the front (rear) while the boom 1a is operated upward, if the distance r becomes smaller than the control start distance r0, the proportional electromagnetic pressure reducing valve as shown in (b) above. The pilot pressure on the extension side of the boom cylinder 3a is limited by 11a, and the boom 1a is gradually decelerated. At the same time, the multiplication unit 7i calculates a command value in the arm dump direction (a speed increase command value in the interference avoidance direction) proportional to the extension side command value of the boom cylinder 3a. On the other hand, the value obtained by subtracting the speed increase command value in the interference avoidance direction from the limit value u calculated by the limit value calculation unit 7c is (+).
At that time, the proportional electromagnetic pressure reducing valve 11b limits the command value on the extension side of the arm cylinder 3b according to the value, and when the value becomes (-), the proportional electromagnetic pressure reducing valve 11c operates and the arm cylinder 3b contracts. The pilot pressure on the side is forcibly increased, and the arm 1b is accelerated in the interference avoidance direction to perform the interference avoidance operation in the interference prevention area. As a result of such a combination of operations, in this case as well, the tip of the front device 1A is
As shown by an arrow M in FIG. 5, the operation is performed along the boundary L in the vicinity of the boundary L of the interference prevention region, and the boom 1a can be safely continuous without worrying about the interference between the front device 1A and the cab 3h. Can be operated.

(D) When the offset 1d is operated to the left, when the tip of the front device 1A approaches the interference prevention area and the distance r becomes smaller than the control start distance r0, the limit value calculation unit 7d calculates. The pilot pressure on the compression side of the offset cylinder 3d is limited by the electromagnetic proportional pressure reducing valve 11d according to the limit value u, and a deceleration command for the offset 1d is issued. As a result, the offset 1d is gradually decelerated and stopped at the boundary L of the interference prevention region. Therefore, the offset 1d can be safely operated without worrying about the interference between the front device 1A and the cab 3h.

In the above operation, the angle detector 6
The boom angle α is detected by a, and the control gain calculation unit 7h
The function generator 71 and the multiplication unit 72h (see FIG. 7) correct the control gain K so that it increases as the boom angle α increases. As a result, as described in the first embodiment, in the operations (b) and (c), hunting is prevented even if the boom angle α changes, and stable deceleration / interference avoidance operation can be performed.

As described above, also in this embodiment, the same effect as that of the first embodiment can be obtained in the hydraulic excavator using the hydraulic pilot type operation lever device.

FIG. 11 and FIG. 1 show the third embodiment of the present invention.
2 will be described. In the present embodiment, the boom cylinder 3 is used as a state quantity that affects the operating characteristics of the front device 1A.
The load pressure for raising the boom of a is detected. In the figure,
The same members and functions as those shown in FIGS. 1, 4 and 7 are designated by the same reference numerals.

In FIG. 11, a pressure detector 18 for detecting the load pressure Pa for raising the boom of the boom cylinder 3a is provided in the actuator pipe line connected to the bottom side of the boom cylinder 3a, and the signal of this pressure detector 18 is controlled. It is input to the control gain calculator 7hA of the unit 7 (see FIG. 1).

The control gain calculator 7hA calculates the control gain K on the basis of the distance r to the interference prevention area and a preset calculation formula as in the first embodiment.
The control gain K is corrected so that it decreases as the input boom-raising load pressure Pa increases.

FIG. 12 shows details of the control gain calculator 7hA. The control gain calculator 7hA includes a function generator 70h,
It has the functions of a function generator 73h and a multiplier 72h. The function generator 70h calculates a basic control gain Ko according to the distance r from the front end of the front device to the interference prevention area, as in the first embodiment. Function generator 73
At h, the correction coefficient K is set according to the load pressure Pa for raising the boom.
Calculate 2. Here, the relationship between the boom raising load pressure Pa and the correction coefficient K2 is that the correction coefficient K2 is 1 or more when the boom raising load pressure Pa is small, and the correction coefficient K2 increases as the boom raising load pressure Pa increases. It is set to be a value of 1 or less. The multiplier 72h multiplies the basic control gain Ko obtained by the function generator 70h by the correction coefficient K2 obtained by the function generator 71h to obtain the control gain K. Accordingly, in the control gain calculation unit 7hA,
The control gain K is corrected so that the rate of change of the control gain with respect to the distance r (the slope of the function) becomes smaller and the maximum value of the control gain K becomes smaller as the load pressure Pa for raising the boom increases.

Here, if the load applied to the front device 1A becomes large, the boom becomes difficult to move during the deceleration / interference avoidance operations of the above (b) and (c), and at the same time the arm moves faster than the boom. Become.

That is, in the hydraulic excavator, even if the operation amount of the same operation lever device (the opening degree of the flow control valve) is used, the boom cylinder 3 is affected by the load applied to the front device 1A.
The flow rate balance of the pressure oil to a and the arm cylinder 3b changes, and the pressure oil tends to flow more easily to the arm 1b than to the boom 1a which has to support a large load particularly as the load increases.

By the way, as described in the first embodiment, in the control for performing the deceleration / interference avoidance operations of the above (b) and (c) of the present invention, the distance r from the interference prevention area, the arm and the boom are reduced. If the balance between the movement of the boom, that is, the ratio of the degree of deceleration of the boom to the distance r and the rate of acceleration of the arm toward the front is lost, hunting may occur in which the boom is stopped and the arm moves repeatedly forward. That is, if the load of the front device changes and the balance of the flow rate of the pressure oil to the boom cylinder and the arm cylinder is lost, the above hunting may occur.

Therefore, in the present embodiment, the pressure detector 18
The boom-raising load pressure Pa is detected by the control gain calculating unit 7hA, and the control gain K is corrected by the control-gain calculating unit 7hA so that the rate of change of the control gain with respect to the distance r (the slope of the function) decreases as the boom-raising load pressure Pa increases. To do.
As a result, when the boom 1a of the above (b) is operated upward, when the load pressure Pa for raising the boom becomes high, the calculation gain 7hA becomes smaller than the control gain K with respect to the distance r.
To increase the rate of change in the forward movement speed of the arm 1b. By correcting the rate of change in the forward movement speed of the arm 1b in this manner, the arm 1b is set at an optimum speed with respect to the change in the load of the front device 1A.
Can be released forward, and the above hunting can be prevented.

The same applies to the above case (c).

As described above, according to this embodiment, the same boom and arm deceleration / interference avoidance operations and offset deceleration / stop operations as in the first embodiment can be performed, and the load applied to the front device is changed. However, hunting can be prevented during deceleration / interference avoidance operations of the boom and arm.

A fourth embodiment of the present invention will be described with reference to FIGS.
Will be described. In the present embodiment, the oil temperature of the hydraulic circuit is detected as a state quantity that affects the operating characteristics of the front device 1A. In the figure, members and functions equivalent to those shown in FIGS. 1, 4 and 7 are designated by the same reference numerals.

In FIG. 13, an oil temperature sensor 15 for detecting the oil temperature of the hydraulic circuit is provided, and the signal of this oil temperature sensor 15 is the control gain calculator 7hB of the control unit 7 (see FIG. 1) and the limit value. It is input to the arithmetic units 7bB and 7cB.

The control gain calculator 7hB calculates the control gain K on the basis of the distance r to the interference prevention area and a preset calculation formula as in the first embodiment.
The control gain K is corrected so that it decreases as the input oil temperature To decreases.

Also in the limit value calculation units 7bB and 7cB, the distance r to the interference prevention area is the same as in the first embodiment.
Then, the limit value u is calculated based on a preset calculation formula, and the limit value u is corrected so as to become smaller as the input oil temperature To becomes lower.

FIG. 14 shows the details of the control gain calculator 7hB. The control gain calculator 7hB is a function generator 70h.
B, function generator 74h, multiplier 72h, upper limit limiter 7
It has the functions of 5h, adder 76h, and constant generator 77h. The function generator 70hB calculates the basic control gain Ko according to the distance r from the front end of the front device to the interference prevention area, as in the first embodiment. However,
Here, a function obtained by shifting the control gain K downward by K1 is used so as not to change the maximum value (K1 = KMAX) of the control gain K of the control gain calculator 7hB at the oil temperature To. The function generator 74h calculates the correction coefficient KT according to the oil temperature To. Here, the relationship between the oil temperature To and the correction coefficient KT is that the correction coefficient KT is 1 when the oil temperature To is high, and the correction coefficient KT is when the influence of the oil temperature is lower than the oil temperature TON which appears in the vehicle body characteristics. It is set to gradually decrease from 1. In the multiplication unit 72h, the basic control gain Ko obtained by the function generator 70h is added to the correction coefficient KT obtained by the function generator 74h.
Is multiplied by to obtain the control gain Ko '. Next, the adder 76
The value of K1 shifted by the function generator 70hB at h is input from the constant generator 77h and added to K0 'to determine the control gain K. Further, the upper limit limiter 75h limits the upper limit of the control gain K to a constant value.

As a result, the control gain calculator 7hB
The control gain K is corrected so that the rate of change of the control gain with respect to the distance r (gradient of the function) becomes smaller and the increase start distance of the control gain (control start distance r0) becomes longer as the oil temperature To becomes lower.

FIG. 15 shows the details of the limit value calculator 7bB. The limit value calculator 7bB has the functions of a function generator 70b, a function generator 71b, a multiplier 72b, and an upper limit limiter 73b. The function generator 70b calculates the basic limit value uo according to the distance r from the front end of the front device to the interference prevention area, as in the first embodiment. The function generator 71b calculates the correction coefficient KT according to the oil temperature To. Here, the relationship between the oil temperature To and the correction coefficient KT is similar to that of the function generator 74h when the oil temperature To is high.
Is 1, and when the influence of the oil temperature falls below the oil temperature TON appearing in the vehicle body characteristic, the correction coefficient KT is set to gradually decrease from 1. In the multiplication unit 72b, the function generator 70b
The basic limit value uo obtained in step 1 is multiplied by the correction coefficient KT obtained by the function generator 71b to obtain the limit value u, and the upper limit limiter 73b limits the upper limit value u to a constant value. As a result, in the limit value calculation unit 7bB, as the oil temperature To becomes lower, the rate of change of the limit value u with respect to the distance r (the slope of the function) becomes smaller and the limit value decrease start distance (control start distance r0) increases the control gain. The limit value u is corrected so that it becomes the same as the start distance and becomes longer.

FIG. 16 shows the details of the limit value calculator 7cB. The limit value calculator 7cB has the functions of a function generator 70c, a function generator 71c, a multiplier 72c, and an upper limit limiter 73c. The function generator 70c calculates the basic limit value uo according to the distance r from the front end of the front device to the interference prevention area, as in the first embodiment. The function generator 71c, the multiplier 72c, and the upper limit limiter 73c are the same as those of the above-described limit value calculator 7bB. As a result, even in the limit value calculation unit 7cB, the rate of change of the limit value u with respect to the distance r (gradient of the function) as the oil temperature To decreases.
Is reduced and the limit value u is corrected such that the limit value decrease start distance (control start distance r0) becomes the same value as the control gain increase start distance.

Here, the characteristics of the hydraulic drive system used in hydraulic construction machines such as hydraulic excavators change with changes in the oil temperature. That is, when the oil temperature is low, the viscosity of the pressure oil is high, the response of the hydraulic equipment is delayed, and the response of the entire control system is deteriorated.

In the control for performing the deceleration / interference avoidance operation of the above (b) and (c) of the present invention, the response of the hydraulic equipment is delayed when the oil temperature becomes low, so that the front end of the front device approaches the interference prevention area. According to the distance r according to the boom 1a
There is a delay in moving the arm 1b forward at the same time as decelerating.

That is, when the boom 1a of (b) above is operated upward, even if a deceleration command for the boom 1a is issued for the distance r from the tip of the front device 1A to the interference prevention area, the hydraulic equipment is actually operated. Delays before the vehicle responds by decelerating, and forward (dump direction) with respect to the arm 1b.
Even if a command is issued to move the robot, the hydraulic device actually responds and a delay occurs until the arm 1b moves forward, so that the tip of the front device 1A may enter the interference prevention area. When the tip of the front device 1A enters the interference prevention area in this way, the computing unit 7bB causes the boom 1a to move.
At the same time as the stop command is issued, the forward operation command to the arm 1b by the calculation unit 7cB becomes a large value. Therefore, after the arm 1b responds to the command, it tries to move forward at a high speed. Then, when the front end of the front device 1a returns to the outside of the interference prevention area, it goes too far forward due to the delayed response of the deceleration of the boom 1a and the movement of the arm 1b at that time. Then, this time, the returning speed of the boom 1a increases and the boom 1a enters the interference prevention area again. This may be repeated to cause a hunting phenomenon.

The same applies when the arm 1b is operated forward (rearward) while operating the boom 1a (c) upward.

Therefore, in the present embodiment, the temperature sensor 15
Thus, the oil temperature is detected, and the control gain K and the limit value u are corrected as described above. As a result, the boom 1a of the above (b) is
When the oil temperature is lower than the predetermined temperature when the is operated upward, the limit values u are reduced earlier with respect to the distance r in the calculation units 7bB and 7cB, and a deceleration command for the boom 1a and the arm 1b is issued at the same time. Similarly, in the calculation unit 7hB, the control gain K is raised earlier with respect to the distance r to issue a forward operation command to the arm 1b. In this way, the hunting is prevented by issuing the boom deceleration command and the arm forward motion command from a position where the distance r is long.

The same applies to the case (c).

As described above, according to the present embodiment, the same boom and arm deceleration / interference avoidance operations and offset deceleration / stop operations as in the first embodiment can be performed, and the oil temperature of the hydraulic circuit becomes low. However, the boom and arm deceleration
It is possible to prevent hunting from occurring during the interference avoidance operation.

The fifth embodiment of the present invention will be described with reference to FIG. In this embodiment, the rotational speed of a prime mover that drives a hydraulic pump is detected as a state quantity that affects the operating characteristics of the front device 1A. In the figure, members and functions equivalent to those shown in FIGS. 1 and 4 are designated by the same reference numerals.

In FIG. 17, the hydraulic pump 2 is connected to the engine 16 and is rotationally driven by the engine 16. A rotation speed sensor 17 for detecting the rotation speed of the engine 16 is arranged in the engine 16, and a signal from the rotation speed sensor 17 is used as a control gain calculation unit 7hC and a limit value calculation unit 7bC of the control unit 7 (see FIG. 1). , 7cC.

The control gain calculator 7hC calculates the control gain K on the basis of the distance r to the interference prevention area and a preset calculation formula as in the first embodiment.
The control gain K is corrected so that it decreases as the input engine speed Ne increases.

Also in the limit value calculators 7bC and 7cC, the distance r to the interference prevention area is the same as in the first embodiment.
And the limit value u is calculated based on a preset calculation formula, and the limit value u is corrected so as to decrease as the input engine speed Ne increases.

Details of the correction method by the engine speed in the control gain calculation unit 7hC and the limit value calculation unit 7b
The details of the correction method based on the engine speed at C and 7 cC are substantially the same as the correction method based on the oil temperature of the fourth embodiment. Then, in the control gain calculator 7hC,
The control gain K is corrected and limited so that the rate of change of the control gain with respect to the distance r (gradient of the function) becomes smaller and the increase start distance of the control gain (control start distance r0) becomes longer as the engine speed Ne increases. Value calculator 7b
In C and 7 cC, the rate of change of the limit value u with respect to the distance r (gradient of the function) becomes smaller as the engine speed Ne becomes higher, and the decrease start distance of the limit value (control start distance r
0) The limit value u is corrected so that it becomes the same value as the increase start distance of the control gain and becomes longer.

Here, the characteristics of the hydraulic drive system used for the hydraulic construction machine such as the hydraulic excavator change with the change of the rotation speed of the engine 17. That is, the engine 17
Since the maximum discharge flow rate of the hydraulic pump 2 changes due to the change in the number of rotations of, the maximum flow rate of the pressure oil that can be used changes,
In particular, as the engine speed increases, the flow rate of the pressure oil increases, so that the operating speed of the entire front device increases.

In the control for performing the deceleration / interference avoidance operation of the above (b) and (c) of the present invention, the deceleration command of the boom 1a (the flow control valve 5a according to the distance r to the interference prevention area at the tip of the front device). Command for opening the arm 1b) and a command for moving the arm 1b forward (command for opening the flow control valve 5b). At this time, the deceleration ratio of the boom 1a to the distance r calculated by the calculation unit 7bC (the decrease ratio of the opening command of the flow rate control valve 5a) and the distance r calculated by the calculation unit 7hC, the multiplication unit 7i, and the addition unit 7j. Assuming that the increase rate of the operation speed of the arm 1b toward the front (the increase rate of the opening degree command of the flow control valve 5b) is constant regardless of the increase in the rotation speed of the engine 16, when the rotation speed of the engine 16 increases, the front Since the operating speed of the entire device increases, the actual decrease rate of the boom speed and the increase rate of the arm speed during the above control increase. That is, the degree of deceleration (gain) of the boom and the speed increase (gain) of the arm with respect to the distance r become large. When the gain is increased as described above, the speed change accompanying the control becomes large and becomes unstable, and the entire front device may cause hunting.

Therefore, in the present embodiment, the rotation speed sensor 1
The rotation speed of the engine 16 is detected by 7 and the control gain K and the limit value u are corrected as described above. Accordingly, when the boom 1a of (b) is operated upward, if the engine speed Ne becomes higher than the predetermined speed, the calculation unit 7b.
In C and 7cC, the limit value u is reduced earlier with respect to the distance r, the deceleration rate of the boom 1a with respect to the distance r (the reduction rate of the opening command of the flow control valve 5a) is reduced, and at the same time, the calculation section 7hC performs the distance r. In contrast, the control gain K is raised earlier, and the speed increase rate of the arm 1b (the increase rate of the opening command of the flow rate control valve 5b) with respect to the distance r is reduced so that the speed decreases and the increase rate does not change. to correct. This stabilizes the control and prevents the hunting.

The same applies to the above case (c).

As described above, according to this embodiment, the same boom and arm deceleration / interference avoidance operations and offset deceleration / stop operations as in the first embodiment can be performed, and the rotation of the engine that drives the hydraulic pump can be performed. Even if the number changes, hunting can be prevented during deceleration / interference avoidance operations of the boom and arm.

The interference prevention device of the present invention is not limited to the above embodiment, and various modifications can be made.

[0126] For example, in the embodiment described above, although using the angle meter for detecting the rotational angle as a means for detecting status variables relating to the position and attitude of the full Ronto device 1A, may detect the stroke of the cylinder . Although the case where the front device and the cab are prevented from interfering with each other has been described, the present invention can be similarly applied to the case where the front device and the part other than the cab are prevented from interfering with each other.

In the above embodiment, the present invention is applied to the interference avoiding operation when the first front member is the boom and the second front member is the arm, and the front end of the front device moves from the front of the cab toward the interference prevention area. Is a front member that requires continuous actuator operation to continuously move the front end of the front device near the interference prevention region, and the second front member moves the front end of the front device near the interference prevention region. Other front members may be used as long as they do not require continuous actuator operation to be continuously moved by, for example, the first front member is an offset, the second front member is an arm, and the side surface of the front device is the lateral direction of the cab. The present invention may be applied to the interference avoiding operation when moving from the direction toward the interference prevention area.

Further, in the above-described embodiment, the present invention is applied to the hydraulic excavator having the front device provided with an offset, but it is also applicable to a normal hydraulic excavator having a mono-boom provided to the front device and a hydraulic excavator having a two-piece boom provided to the front device. Similarly, the present invention is applied to obtain the same effect.

Furthermore, in the above embodiment, the oil quantity, the engine speed, and the load pressure for raising the boom are given as examples of the state quantities that affect the operating characteristics of the front device, but the operating characteristics of the front device are affected. The present invention may be applied by detecting any other state quantity as long as it is given.

[0130]

According to the present invention, the front device and the driver's cab
Alternatively, the front device can be continuously moved while preventing interference with the vehicle body part other than the driver's cab, and continuous earth lifting can be performed without stopping even near the interference prevention area, and a wide working range is secured. can do.

Further, according to the present invention, it is possible to prevent hunting from occurring during the deceleration / interference avoidance operation of the first and second front members even if the state quantity affecting the operation characteristics of the front member changes.

[Brief description of drawings]

FIG. 1 is a diagram showing an interference prevention device for a hydraulic excavator according to a first embodiment of the present invention together with its hydraulic circuit.

FIG. 2 is a side view showing the outer appearance of a hydraulic excavator to which the present invention is applied.

FIG. 3 is a view showing the outer appearance of a hydraulic excavator to which the present invention is applied, from above.

FIG. 4 is a functional block diagram showing a control function of a control unit.

FIG. 5 is a diagram showing a region used in the interference prevention control of the present embodiment.

FIG. 6 is a diagram showing a region used in the interference prevention control of the present embodiment.

FIG. 7 is a functional block diagram showing details of a control gain calculator.

FIG. 8 is a diagram showing changes in operating characteristics of the front device due to changes in boom angle.

FIG. 9 is a diagram showing an interference prevention device for a hydraulic excavator according to a second embodiment of the present invention together with its hydraulic circuit.

FIG. 10 is a functional block diagram showing a control function of a control unit according to the second embodiment of the present invention.

FIG. 11 is a functional block diagram showing a control function of a control unit according to the third embodiment of the present invention.

FIG. 12 is a functional block diagram showing details of a control gain calculator.

FIG. 13 is a functional block diagram showing a control function of a control unit according to the fourth embodiment of the present invention.

FIG. 14 is a functional block diagram showing details of a control gain calculator.

FIG. 15 is a functional block diagram showing details of a limit value calculation unit.

FIG. 16 is a functional block diagram showing details of a limit value calculation unit.

FIG. 17 is a functional block diagram showing a control function of the control unit according to the fifth embodiment of the present invention.

[Explanation of symbols]

1A front device 1B car body 1a boom 1b arm 1c bucket 1d offset 1e Upper revolving structure 1f Undercarriage 2,8 pump 3a-3g hydraulic actuator 4a-4g operation lever device (electric type) 5a-5g Flow control valve (electromagnetic drive type) 6a to 6c Angle detector 7 control unit 7n, 7q, 7r Control start distance correction value calculation unit 7p adder 9 Operation lever device (hydraulic type) 10a-10g Flow control valve (hydraulic drive type) 11a to 11d proportional solenoid pressure reducing valve 12 Shuttle valve 13 Pressure detector 15 Temperature sensor 16 engine 17 Speed sensor 18 Pressure detector

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Eiji Egawa, Eiji Egawa, 650 Kandamachi, Tsuchiura City, Ibaraki Prefecture Hitachi Construction Machinery Co., Ltd., Tsuchiura Plant (72) Inventor, Junichi Hosono, 650, Kachidate Town, Tsuchiura City, Ibaraki Hitachi Construction Machinery Co., Ltd. Inside the Tsuchiura Plant (72) Toshiaki Nishida Toshiaki Nishida 650 Jinrachicho, Tsuchiura City, Ibaraki Hitachi Construction Machinery Co., Ltd. Inside the Tsuchiura Plant (56) Reference JP-A-6-146326 (JP, A) JP-A-6-200537 (JP , A) Furukaihei 5-30080 (JP, U) International Publication 95/033100 (WO, A1) (58) Fields investigated (Int.Cl. ⁷ , DB name) E02F 3/43 E02F 9/24

Claims (8)

(57) [Claims] 1. A first and a second rotatable vertically and horizontally.
A front device composed of a plurality of front members including a front member, a plurality of hydraulic actuators for driving the plurality of front members, a plurality of operating means for instructing the operation of the plurality of front members, and a plurality of these operations. A construction machine having a plurality of flow rate control valves for controlling the flow rate of pressure oil supplied to a corresponding hydraulic actuator according to each operation signal of the means, and calculating the position and attitude of the front device, Based on the position and posture, the front device is installed around the driver's cab or the body part other than the cab.
In an interference prevention device for controlling so as not to enter an interference prevention region set in advance in (a), the distance from the front device to the interference prevention region is calculated based on the position and orientation of the front device, and the distance is set in advance. When the control start distance is less than or equal to
Operation of the first front member to decelerate the front member
Correcting the operation signals work unit, and the corrected operation signal
From the front device to the interference prevention area
First correction means for correcting the operation signal of the operation means of the second front member so as to increase the speed of the second front member in the interference avoidance direction of the interference prevention area according to the distance ; and (b) the front device. Detection means for detecting a state quantity that affects the operating characteristic; and (c) correcting the control gain for increasing the speed of the second front member in the first correction means according to the state quantity detected by the detection means. An interference prevention device for a construction machine, comprising: a second correction means. 2. The interference preventing device for a construction machine according to claim 1, wherein the state quantity is an operating angle of the first front member, and the second correcting means increases an operating angle of the first front member. According to the above, the interference preventing device for a construction machine, wherein the control gain for increasing the speed of the second front member in the first correcting means is corrected to be large. 3. The interference preventing device for a construction machine according to claim 1, wherein the state quantity is a load pressure of a hydraulic actuator of the first front member, and the second correcting means is configured to increase the load pressure as the load pressure increases. An interference prevention device for a construction machine, wherein correction is performed so that a control gain for increasing the speed of a second front member in the first correction means is reduced. 4. The interference preventing device for a construction machine according to claim 1, wherein the state quantity is an oil temperature, and the second correcting means has a second front member in the first correcting means as the oil temperature becomes lower. An interference prevention device for a construction machine, characterized in that the control gain for increasing the speed is corrected to be small. 5. The interference preventer for a construction machine according to claim 1, wherein the state quantity is a rotation speed of a prime mover driving the hydraulic pump, and the second correction means is arranged to increase the rotation speed as the rotation speed increases. 1. An interference prevention device for a construction machine, wherein correction is performed such that a control gain for increasing the speed of the second front member in the first correction unit is reduced. 6. The interference preventing device for a construction machine according to claim 1, wherein the first correcting means has a maximum value when (a1) a distance from the front device to an interference preventing area is larger than the control start distance. Keep
When the distance is less than or equal to the control start distance, the distance decreases as the distance decreases, and when the distance becomes less than or equal to a negative value, the first calculation means calculates a first limit value of the operation signal of the first front member. And (a2) keeps the maximum value when the distance from the front device to the interference prevention area is larger than the control start distance,
When the distance becomes equal to or less than the control start distance, it becomes smaller as the distance becomes smaller, becomes 0 when the distance becomes 0, and becomes smaller according to the negative value when the distance becomes a negative value. A second calculating means for calculating a second limit value of the signal; and (a3) 0 when the distance from the front device to the interference prevention area is larger than the control start distance, and the distance becomes equal to or smaller than the control start distance. Then, the third calculation means calculates the control gain for increasing the speed of the second front member so that the distance becomes larger as the distance becomes smaller and becomes the maximum value when the distance becomes 0 or less, and (a4) the first limit value is set. First signal correction means for correcting the operation signal of the operation means of the first front member so as not to exceed (a5) the corrected operation signal corrected by the first signal correction means and calculated by the third calculation means Fourth calculation means for calculating a speed-up command value in the interference avoiding direction of the second front member with respect to the interference prevention area based on the control gain, and (a6) second calculation means. A second signal correction means for correcting the operation signal of the operation means of the second front member using the limit value and the speed-up command value in the interference avoidance direction calculated by the fourth calculation means, 2. The interference preventing device for a construction machine, wherein the second correcting unit corrects a change rate of the control gain calculated by the third calculating unit with respect to the distance according to the state quantity. 7. The construction machine interference prevention device according to claim 6, wherein the second correcting means controls by changing a maximum value of a control gain calculated by the third calculating means in accordance with the state quantity. An interference prevention device for a construction machine, which corrects a change rate of a gain with respect to a distance. 8. The interference preventer for a construction machine according to claim 6, wherein the second correction means changes the increase start distance of the control gain calculated by the third calculation means in accordance with the state quantity. The rate of change of the control gain with respect to the distance is corrected, and the decrease start distance of the first and second limit values calculated by the first and second calculating means is changed to be the same as the increase start distance of the control gain. So these first
And an interference prevention device for a construction machine, which corrects a change rate of the second limit value with respect to a distance.