JPH09256403A - Interference preventing device for construction machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To continuously move a front device under the prevention of the interference thereof with a cab, maintain a wide working area, and ensure the avoidance of the ingress pf the front device into an interference zone, even upon the appearance of a change in thermodynamic function for affecting the operation characteristic of the front device. SOLUTION: An arithmetic operation part 7b computes the limit of a boom instruction value, thereby making a correction for an operation signal for a boom operation lever device 4a. Also, a detection line 7m detects the boom instruction value and, then, a control gain operation part 7h and a multiplication part 7i compute an increasing speed instruction value for an arm along an interference avoidance direction, before the entry of a front device into an interference prevention zone. In addition, a limit value operation part 7c, an adding part 7j and a minimum value selector part 7f correct an operation signal for an arm operation lever device 4b. At the same time, oil temperature is detected and a correction is made to extend the control start distances of the arithmetic operation parts 7b to 7d, and 7h, according to an oil temperature drop.

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 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 prior art, 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 oil temperature of the hydraulic circuit. Therefore, due to the change in the state quantity, the actual stoppage of the operation of the front device is delayed with respect to the operation stop command of the front device, and the front device may enter the interference prevention area beyond the stop position. There is.

A first object of the present invention is to provide an interference prevention device for a construction machine, which can continuously move the front device while preventing interference between the front device and the cab, and can secure a wide working range. That is.

A second object of the present invention is to prevent the interference of the construction equipment with the interference prevention device of the construction machine, even if the state quantity affecting the operation characteristics of the construction equipment changes. Is to provide.

[0011]

[Means for Solving the Problems]

(1) In order to achieve the above-mentioned first and second objects, the present invention provides a front device including a plurality of front members including first and second front members that are rotatable in the vertical and horizontal directions. Supplying 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 corresponding hydraulic actuator according to respective operation signals of the plurality of operating means Which is provided in a construction machine having a plurality of flow rate control valves for controlling the flow rate of pressure oil, calculates the position and orientation of the front device, and based on this position and orientation, prevents the front device from presetting interference. In an interference prevention device for controlling so as not to enter the area, (a) the distance from the front device to the interference prevention area is determined based on the position and orientation of the front device. When the distance becomes equal to or shorter than a preset control start distance, the first front member is decelerated and the second front member is accelerated in the interference avoiding direction according to the operation of the first front member. First correction means for correcting the operation signals of the operation means of the first and second front members, (b) a detection means for detecting a state quantity that affects the operating characteristics of the front device, and (c) this detection means. And a second correction unit that corrects the control start distance of the first correction unit so as to avoid entering the interference prevention area of the front device due to a change in the state amount detected in step S1. To do.

As described above, when the first correction means is provided and 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 and the second front member is avoided. By correcting the operation signals of the operating means of the first and second front members so as to accelerate in the direction, the front device gradually decelerates when approaching the interference prevention area, and moves along the vicinity of the boundary of the interference prevention area. As a result, the front device can be continuously moved while preventing the front device and the cab from interfering with each other.

Further, by increasing the speed of the second front member in the interference avoidance direction in the interference prevention area in response to the operation of the first front member, the movement of the front device is predicted from the operation of the first front member, and the front device is operated. It is possible to perform the interference avoidance operation in predictive control, in which the interference avoidance operation is performed before entering the interference prevention area, and thus the amount of invasion into the interference prevention area can be set to 0 or minimized, so that the interference prevention area can be narrowed and a wide work can be performed. The range can be secured.

Further, in a hydraulic construction machine such as a hydraulic excavator, when the state quantity such as the oil temperature changes, the operation characteristics of the front device change, and the front device decelerates or stops during the deceleration / interference avoidance operation, or It becomes difficult to accelerate, and there is a possibility of entering the interference prevention area.

According to the present invention, the state quantity that affects the operating characteristics of the front device is detected as described above, and the second correction means moves to the interference prevention area of the front device due to the change of the state quantity according to the state quantity. The control start distance of the first correction means is corrected so as to avoid the invasion of. As a result, even if the state quantity such as the oil temperature changes, it is possible to reliably prevent the front device from entering the interference region.

(2) In the above (1), preferably,
The second correction means calculates the correction value of the control start distance according to the state quantity, and subtracts the correction value from the distance from the front device to the interference prevention area calculated by the first correction means. And means.

(3) In the above (1), for example, the state quantity is an oil temperature, and the second correction means has a longer control start distance of the first correction means as the oil temperature becomes lower. To correct.

(4) 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 start distance of the means is corrected to be long.

(5) 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 is configured to change the first pressure as the load pressure increases. Correction is performed so that the control start distance of the correction unit becomes longer.

(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, which has 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. A first signal correction means, (a5)
Based on the correction operation signal corrected by the first signal correction means and the control gain calculated by the third calculation means, an acceleration command value in the interference avoiding direction with respect to the interference prevention area of the second front member is calculated. Fourth calculating means for performing, (a6)
Compensating the operation signal of the operation means of the second front member using the second limit value calculated by the second calculation means and the acceleration command value in the interference avoidance direction calculated by the fourth calculation means. And a two-signal correction means.

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.

(7) In the above (6), preferably,
The fourth calculation means is means for multiplying the correction operation signal corrected by the first signal correction means and the control gain calculated by the third calculation means, and the multiplication value is increased in the interference avoidance direction. (8) Further, in the above (6), preferably, the second signal correction means is the second signal correction means.
The acceleration command value in the interference avoidance direction is subtracted from the limit value, and the operation signal of the operation means of the second front member is corrected so as not to exceed the subtracted value.

(9) Further, in the above (6), for example, the plurality of operating means are of an electric lever type which 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.

(10) In the above (9), 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.

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

(12) In the above item (11), preferably, there is further provided means for detecting the pilot pressure of the operating means of the first front member, and the fourth computing means further comprises a detected value of the pilot pressure and the 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.

(13) In the above (1) to (12), 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.

[0030]

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.

Further, as shown in FIGS. 2 and 3, the hydraulic excavator includes a multi-joint type front device 1A composed of a boom 1a, an arm 1b, a bucket 1c and an offset 1d which rotate in the vertical direction, and an upper swivel. 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 operating lever devices 4a to 4g are electric lever systems which drive the corresponding flow rate control valves 5a to 5g according to the operating amount, and the operating amounts of the operating 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.

Further, the interference prevention device of this embodiment has a state quantity that affects the operating characteristics of the front device, particularly the operating characteristics when the deceleration / interference avoiding operation (described later) of the front device relating to the control of the present invention is performed. The oil temperature sensor 15 detects the oil temperature of the hydraulic circuit, and the signal of the oil temperature sensor 15 is also input to the control unit 7.

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. Section 7j, detection line 7m, operation parts 30a to 36b of command values to the flow control valves corresponding to the expansion side and contraction side of each actuator, operation part 7 of control start distance correction value
It has each function of n and the addition part 7p.

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 set.
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 control start distance correction value calculation unit 7n receives the oil temperature To detected by the oil temperature sensor 15, and corrects the control start distance r0 in the calculation units 7b to 7d and 7h according to the input oil temperature To. Calculate the value rof. At this time, the calculation unit 7
In n, the correction value rof is 0 when the oil temperature is equal to or higher than a predetermined temperature Ta, for example, 50 ° C., and when the oil temperature is equal to or lower than the predetermined temperature Ta, the correction value rof is a constant value as the oil temperature decreases,
For example, it is set to gradually increase toward 20 cm.

In the adding section 7p, the front posture calculating section 7a
The calculation unit 7 of the control start distance correction value from the distance r calculated in
The correction value rof calculated in n is subtracted to calculate the corrected distance r. By correcting the distance r in this way, as shown in FIG. 7, in the calculation units 7b to 7d and 7h,
The control start distance r0 is corrected to increase as the oil temperature To decreases.

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

Here, in the calculation unit 7d of the offset 1d, the limit value u keeps 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 arithmetic units 7b to 7d, the maximum value of the limit value u is set to a value which substantially coincides with the maximum value of the operation signals of the operation lever devices 4a, 4b and 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.
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 smaller 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 reaches the maximum value. The relationship with is set.

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
The temperature sensor 15 constitutes a detecting means for detecting a state quantity which affects the operating characteristics of the front device 1A, and the calculating section 7n and the adding section 7p constitute the detecting means. The second correction means is arranged to correct the control start distance r0 of the first correction means so as to prevent the front device 1A from entering the interference prevention area due to the change of the state quantity detected by the means. .

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, 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 region, the limit value u of the limit value calculation unit 7c is 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) Further, when the boom 1a is operated upward, when the front end of the front device 1A approaches the interference prevention area and the distance r becomes smaller than the control start distance r0, it is calculated by the limit value calculation unit 7b. 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 forward (rearward) while the boom 1a is operated upward, if the distance r becomes smaller than the control start distance r0, the boom cylinder 3a of 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 front end 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 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 characteristics of a hydraulic drive system used in a hydraulic construction machine such as a hydraulic excavator change due to a change in 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 of the present invention, when the oil temperature becomes low, the response of the hydraulic equipment is delayed, so that the front device 1
There is a possibility that the operation characteristics of A change, the front device becomes difficult to decelerate, stop, or accelerate during the deceleration / interference avoidance operation or the deceleration / stop operation, and may enter the interference prevention area.

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 front end of the front device 1A into the interference prevention area, the hydraulic device actually responds and a delay occurs until the arm 1b moves forward.

When the arm 1b of (a) is operated toward the front, the response of the hydraulic equipment delays the delay of the deceleration control by the calculator 7c, and the front end of the front device 1A may enter the interference prevention area. There is a nature.

When the arm 1b is operated to the front (rear) while operating the boom 1a in the above (c) upward, the tip of the front device 1A is located in the interference prevention area as in the case of the above (b). May get in.

Further, when the offset 1d in the above (d) is operated to the left, the deceleration control by the computing unit 7d is delayed due to the response delay of the hydraulic equipment, and the tip of the front device 1A falls within the interference prevention area. May get in.

Therefore, in the present embodiment, the temperature sensor 15
The oil temperature is detected by the control start distance correction value calculation unit 7n and the addition unit 7p, and the control start distance r0 in the calculation units 7b to 7d and 7h as the oil temperature becomes lower than the predetermined temperature Ta.
The distance r is corrected so that becomes longer. As a result, when the boom 1a of (b) above is operated upward, when the oil temperature becomes lower than the predetermined temperature Ta, the limit values u are reduced earlier than the distance r in the calculation units 7b and 7c, and the boom 1a is reduced.
Also, at the same time when the deceleration command for the arm 1b is issued, the control unit K similarly raises the control gain K earlier with respect to the distance r so as to issue a forward operation command for the arm 1b. By issuing the boom and arm deceleration command and the arm forward operation command from a position where the distance r is long, the front end of the front device 1A is prevented from entering the interference prevention area.

The same applies to the case (c).

Further, when the arm 1b of the above (a) is operated toward the front, when the oil temperature becomes lower than the predetermined temperature Ta, the limit value u is decreased earlier than the distance r in the calculation unit 7c, and the arm 1b is reduced. Issue the deceleration command of. This can prevent the front end of the front device 1A from entering the interference prevention area.

Further, even when the offset 1d in the above (d) is operated to the left, if the oil temperature becomes lower than the predetermined temperature Ta, the calculation unit 7d will advance the limit value u to the distance r.
Is made smaller and a deceleration command for offset 1d is issued. This can prevent the front end of the front device 1A from entering the interference prevention area.

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 invasion into the interference prevention area can be set to 0 or minimum. Since the interference prevention area can be narrowed, a wide working range can be secured.

When the arm 1b is operated to the front (back), the arm is gradually decelerated as the front end of the front device 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 reduced.
Since it stops at, you can safely operate the offset as well.

Further, according to the present embodiment, even when the oil temperature is low due to the work in winter or in a cold region, the front device 1A is operated during deceleration / interference avoidance operation of the boom and arm and during deceleration / stop operation of offset. Can be prevented from entering the interference prevention area.

A second embodiment of the present invention will be described with reference to FIGS. The present embodiment is applied to a hydraulic shovel using a hydraulic pilot system as an operation 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. 8, a 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 above-described hydraulic excavator 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, the maximum / minimum value selecting section for limiting the input is not required, and instead, the boom is raised 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 respectively used as the first and second front members, as in the first embodiment, the angle detectors 6a to 6c, the pressure detector 13, the arithmetic 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 temperature sensor 15 constitutes a first correcting means for correcting the operation signals of the operating means 4a, 4b, the temperature sensor 15 constitutes a detecting means for detecting a state quantity which affects the operating characteristics of the front device 1A, and the calculating section 7n and the adding section. 7p is
Second correction means for correcting the control start distance r0 of the first correction means according to the state quantity detected by the detection means so as to prevent the front device 1a from entering the interference prevention area due to the change of the state quantity. Configure.

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, 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, 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 calculating section 7c is reduced.
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, when 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 front end of the front device 1A approaches the interference prevention area and the distance r becomes smaller than the control start distance r0, it is calculated by the limit value calculator 7d. 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.

During the above operation, the temperature sensor 1
5, the oil temperature is detected, and the control start distance correction value calculation unit 7n
And the addition unit 7p, the calculation unit 7b-
The distance r is corrected so that the control start distance r0 in 7c and 7h becomes longer. As a result, as described in the first embodiment, even if the oil temperature changes during the deceleration / interference avoidance operation of the boom and arm or the deceleration / stop operation of the offset in the above (a) to (d), the front device It is possible to prevent the tip of 1A from entering the interference prevention area.

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 operation lever device of the hydraulic pilot system.

The third embodiment of the present invention is shown in FIGS.
1 will be described. In the above embodiment, the front device 1
Although the oil temperature is detected as the state quantity that affects the operation characteristics of A, this embodiment detects the rotation speed of the prime mover that drives the hydraulic pump. In the figure, members and functions equivalent to those shown in FIGS. 1 and 4 are designated by the same reference numerals.

In FIG. 10, the hydraulic pump 2 is connected to the engine 16 and is rotationally driven by the engine 16. A rotation speed sensor 17 that detects the rotation speed of the engine 16 is arranged in the engine 16, and a signal of the rotation speed sensor 17 is input to a control start distance correction value calculation unit 7q of the control unit 7 (see FIG. 1). . The calculation unit 7q calculates the correction value rof of the control start distance r0 in the calculation units 7b to 7d and 7h according to the input engine speed Ne. At this time, in the calculation unit 7q, if the engine speed Ne is a low speed predetermined speed Ni, for example, an idle speed 700 rpm or less, the correction value rof is 0, and the engine speed Ne is
Is equal to or higher than a predetermined rotation speed Ni, the correction value rof gradually increases toward a constant value, for example, 20 cm as the engine rotation speed Ne increases, and the engine rotation speed Ne reaches a high-speed predetermined rotation speed Np, for example, 2000 rpm. Then, above that, the correction value rof is set to maintain the constant value.

In the adding unit 7p, the front posture calculating unit 7a
The calculation unit 7 of the control start distance correction value from the distance r calculated in
The correction value rof calculated in q is subtracted to calculate the corrected distance r. By correcting the distance r in this way, as in the case of the first embodiment shown in FIG.
At 7d and 7h, the control start distance r0 is corrected to become longer as the engine speed Ne becomes higher.

Here, the characteristics of the hydraulic drive system used in the hydraulic construction machine such as the hydraulic excavator change according to the change in 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 revolutions of the
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. When the operating speed of the front device is increased in this way, it becomes difficult for the front device to decelerate, stop, or accelerate during the deceleration / interference avoidance operation or the deceleration / stop operation of the above (a) to (d), and the oil temperature increases. Similar to the case where the height increases, the tip of the front device 1A may enter the interference prevention area.

Therefore, in the present embodiment, the rotation speed sensor 1
The rotation speed of the engine 16 is detected by 7 and the control start distance correction value calculation unit 7q and the addition unit 7p calculate the control start distance r0 in the calculation units 7b to 7d and 7h as the engine rotation speed becomes higher than the predetermined rotation speed Ni. The distance r is corrected so that it becomes longer. As a result, when the boom 1a of the above (b) is operated upward, when the engine speed Ne becomes higher than the predetermined speed Ni, the limit values u are reduced earlier than the distance r in the calculation units 7b and 7c. , The boom 1a and the arm 1b are decelerated, and at the same time, the calculation unit 7
At h, the control gain K is raised earlier than the distance r, and a forward operation command of the arm 1b is issued. By issuing the boom and arm deceleration command and the arm forward operation command from a position where the distance r is long, it is possible to prevent the front end of the front device 1A from entering the interference prevention area.

The same applies to the above case (c).

Even when the arm 1b of (a) is operated toward the front, when the engine speed Ne becomes higher than the predetermined speed Ni, the limit value u is reduced earlier in the calculation unit 7c with respect to the distance r. , A deceleration command for the arm 1b is issued. This can prevent the front end of the front device 1A from entering the interference prevention area.

Further, even when the offset 1d in (c) above is operated to the left, the engine speed Ne is equal to the predetermined speed Ni.
When it becomes higher, the limit value u is reduced earlier with respect to the distance r in the calculation unit 7d, and the deceleration command for the offset 1d is issued. This can prevent the front end of the front device 1A from entering the interference prevention area.

In the calculating unit 7q shown in FIG. 10, the engine speed Ne is replaced by the engine speed Ne as shown in FIG.
May be set to the correction value rof. That is, in FIG. 11, the engine speed Ne is a low predetermined speed Ni,
For example, when the idling speed is 700 rpm or less, the correction value rof is a negative constant value, for example, −20 cm, and when the engine speed Ne becomes equal to or higher than the predetermined rotation speed Ni, the correction value rof increases as the engine speed Ne increases. When the engine speed Ne gradually increases toward 0 and reaches a high-speed predetermined speed Np, for example, 2000 rpm, the correction value rof is set to maintain 0 above that. On the other hand, at this time, the initial value r0 of the control start distance in the calculation units 7b to 7d and 7h is set to be longer than that in the above embodiment, for example, 50 cm, in accordance with the characteristics when the engine speed is high. In this way, the calculation unit 7q and the calculation units 7b to 7d and 7
Even if h is set, the correction result of the deceleration start distance is the same as that shown in FIG. 10, and the same effect can be obtained.

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, it is possible to prevent the front end of the front device 1A from entering the interference prevention area during deceleration / interference avoidance operation of the boom and arm or during deceleration / stop operation of offset.

A fourth embodiment of the present invention will be described with reference to FIG. In the present embodiment, the load pressure for raising the boom of the boom cylinder 3a 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. 12, a pressure detector 18 for detecting the load pressure Pa for raising the boom of the boom cylinder 3a is provided in an actuator pipe line connected to the bottom side of the boom cylinder 3a, and the signal of this pressure detector 18 is controlled. Calculation unit 7 of control start distance correction value of unit 7 (see FIG. 1)
Input to r. The calculation unit 7r calculates the correction value rof of the control start distance r0 in the calculation units 7b to 7d and 7h according to the input boom raising load pressure Pa. At this time,
In the calculation unit 7r, the correction value rof is 0 when the boom raising load pressure Pa is less than or equal to the low predetermined pressure Po, and when the boom raising load pressure Pa is greater than or equal to the predetermined pressure Po, the load pressure Pa increases. Accordingly, the correction value rof gradually increases toward a constant value, for example, 20 cm, and when the load pressure Pa reaches a predetermined high pressure Pp, the correction value rof is further exceeded.
Is set so as to maintain the constant value.

In the adding section 7p, the front posture calculating section 7a
The calculation unit 7 of the control start distance correction value from the distance r calculated in
The correction value rof calculated in r is subtracted, and the corrected distance r is output to the arithmetic units 7b to 7d and 7h. Thus the distance r
As described in the first embodiment shown in FIG. 7, the control start distance r0 in the calculation units 7b to 7d and 7h increases as the boom raising load pressure Pa increases.
Is corrected to be longer.

Here, when the load applied to the front device 1A is increased, the inertia of the front device is increased, and the front device is decelerated or stopped or accelerated during the deceleration / interference avoidance operation of the above (a) to (d). It becomes difficult, and the tip of the front device 1A may enter the interference prevention area.

On the other hand, when the load applied to the front device 1A increases, the load pressure on the boom raising side of the boom cylinder 3a increases, so that the load applied to the front device 1A can be detected by detecting the load pressure Pa for raising the boom.

Therefore, in the present embodiment, the pressure detector 18
The load pressure Pa for raising the boom is detected by the control start distance correction value calculating unit 7q and the adding unit 7p, and as the load pressure Pa for raising the boom becomes higher than the predetermined pressure Po, the calculating unit 7b.
The distance r is corrected so that the control start distance r0 at 7d and 7h becomes longer. As a result, when the boom 1a of (b) above is operated upward, when the load pressure Pa for raising the boom becomes higher than the predetermined pressure Po, the limit values u are reduced earlier than the distance r in the calculation units 7b and 7c. Then, at the same time when the deceleration command for the boom 1a and the arm 1b is issued, the control gain K is similarly raised earlier with respect to the distance r in the calculation unit 7h, and the operation command to the front of the arm 1b is issued. By issuing the boom and arm deceleration command and the arm forward operation command from a position where the distance r is long, it is possible to prevent the front end of the front device 1A from entering the interference prevention area.

The same applies to the above case (c).

Also, when the arm 1b of (a) above is operated toward you, the load pressure Pa for raising the boom is not greater than the predetermined pressure Po.
When it becomes higher, the limit value u is reduced earlier in the calculation unit 7c with respect to the distance r, and a deceleration command for the arm 1b is issued. This can prevent the front end of the front device 1A from entering the interference prevention area.

Further, even when the offset 1d in the above (c) is operated to the left, when the boom raising load pressure Pa becomes higher than the predetermined pressure Po, the limit value u is set earlier than the distance r in the calculation unit 7d. It is made small and the deceleration command of offset 1d is issued. As a result, the front device 1A
Can be prevented from entering the interference prevention area.

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 changes. Even when the boom and the arm are decelerated and the interference is avoided, the front end of the front device 1A can be prevented from entering the interference prevention area.

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

For example, in the above embodiment, the operation signal given to the flow control valve of the boom is detected to predict the movement of the front device, but the detection value of the angle detector for detecting the rotation angle of the boom is detected. This value may be used by differentiating to obtain the angular velocity. Further, although the goniometer for detecting the rotation angle is used as the means for detecting the state quantity related to the position and posture of the front device 1A, the stroke of the cylinder may be detected. 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 the present invention is also applied to a normal hydraulic excavator having a mono boom in the front device and a hydraulic excavator having a two-piece boom in the front device. Similarly, the present invention is applied to obtain the same effect.

Further, in the above embodiment, the oil temperature, the engine speed, and the front load (load pressure for raising the boom) are considered as the state quantities that affect the operating characteristics of the front device. The present invention may be applied by detecting any other state quantity that has an influence.

[0113]

According to the present invention, the front device can be continuously moved while preventing the front device and the cab from interfering with each other, so that continuous lifting of earth and sand can be performed without stopping even in the vicinity of the interference prevention area. It is possible to secure a wide working range.

Further, according to the present invention, even when the state quantity that affects the operation characteristics of the front member changes, the front end of the front device is in the interference prevention region during the deceleration / interference avoidance operation of the first and second front members. It can be prevented from entering.

[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 illustrating 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 diagram showing a change in a control start distance by correcting the distance.

FIG. 8 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. 9 is a functional block diagram showing a control function of a control unit according to the second embodiment of the present invention.

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

FIG. 11 is a diagram illustrating a modified example of a control start distance correction value calculation unit according to the third embodiment.

FIG. 12 is a functional block diagram showing a control function of a control unit according to a fourth embodiment of the present invention.

[Explanation of symbols]

 1A Front device 1B Vehicle body 1a Boom 1b Arm 1c Bucket 1d Offset 1e Upper revolving structure 1f Lower traveling structure 2,8 Pump 3a-3g Hydraulic actuator 4a-4g Operation lever device (electric type) 5a-5g Flow control valve (electromagnetic drive type) ) 6a-6c Angle detector 7 Control unit 7n, 7q, 7r Control start distance correction value calculation part 7p Addition part 9 Operation lever device (hydraulic type) 10a-10g Flow control valve (hydraulic drive type) 11a-11d Proportional electromagnetic pressure reduction Valve 12 Shuttle valve 13 Pressure detector 15 Temperature sensor 16 Engine 17 Rotation speed sensor 18 Pressure detector

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Eiji Egawa Eiji Egawa Kuchidachi-cho 650, Tsuchiura-shi, Ibaraki Hitachi Construction Machinery Co., Ltd. Tsuchiura factory (72) Inventor Toshiaki Nishida 650 Jinrachi-cho, Tsuchiura-shi, Ibaraki Hitachi Construction Machinery Co., Ltd.

Claims (13)

[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, An interference prevention device for controlling the front device so as not to enter a preset interference prevention region based on a position and a posture, including: (a) a distance from the front device to the interference prevention region based on a position and a posture of the front device. When the distance is calculated and the distance becomes equal to or smaller than a preset control start distance, the first
A first correction for decelerating the front member and correcting the operation signals of the operating means of the first and second front members so as to accelerate the second front member in the interference avoiding direction in response to the operation of the first front member. And (b) detection means for detecting a state quantity that affects the operating characteristics of the front device, and (c) a state quantity of the front device due to a change in the state quantity according to the state quantity detected by the detection means. An interference prevention device for a construction machine, comprising: a second correction unit that corrects a control start distance of the first correction unit so as to avoid entering the interference prevention region. 2. A construction machine interference prevention device according to claim 1, wherein the second correction means calculates the correction value of the control start distance according to the state quantity, and the first correction means calculates the correction value. And a means for subtracting the correction value from the distance from the front device to the interference prevention area. 3. The interference preventer for a construction machine according to claim 1, wherein the state quantity is an oil temperature, and the second correction means sets a control start distance of the first correction means as the oil temperature becomes lower. An interference prevention device for a construction machine, which is characterized in that it is corrected to be long. 4. The interference preventing device 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 increases the rotation speed as the rotation speed increases. (1) An interference prevention device for a construction machine, which corrects the control start distance of the correction means to be long. 5. 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 preventing device for a construction machine, wherein the control start distance of the first correction means is corrected to be long. 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 a control gain for increasing the speed of the second front member, which increases as the distance becomes smaller and becomes maximum when the distance becomes 0 or less, and (a4) exceeds the first limit value. A first signal correcting means for correcting the operation signal of the operating means of the first front member so as not to exist (a5) corrected operation signal corrected by the first signal correcting means and calculated by the third computing means Fourth calculation means for calculating a speed increase command value in the interference avoidance direction of the second front member with respect to the interference prevention area based on the control gain; and (a6) second limit value calculated by the second calculation means. And a second signal correction means for correcting the operation signal of the operation means of the second front member using the speed increase command value in the interference avoidance direction calculated by the fourth calculation means. Machine interference prevention device. 7. The interference preventing device for a construction machine according to claim 6, wherein the fourth calculating means corrects the operation signal corrected by the first signal correcting means and the control gain calculated by the third calculating means. And an interference prevention device for a construction machine, wherein the multiplication value is a speed increase command value in the interference avoidance direction. 8. The interference preventing device for a construction machine according to claim 6, wherein the second signal correcting means subtracts a speed increasing command value in the interference avoiding direction from the second limit value, and the subtracted value is used. An interference prevention device for a construction machine, characterized in that an operation signal of the operation means of the second front member is corrected so as not to exceed. 9. The interference preventing device for a construction machine according to claim 6, wherein the plurality of operating means are of an electric lever type which outputs an electric signal as the operation signal, and the first signal correcting means is the first signal correcting means. A smaller one of the operation signal of the operating means of the front member and the first limit value is selected, and the selected value is output to the flow control valve of the first front member as a command signal, and the second signal correcting means is used for the second signal correcting means. A smaller one of the operation signal of the operating means of the second front member and the speed-up command value in the interference avoiding direction is selected, and the selected value is output as a command signal to the flow control valve of the second front member. A featured interference prevention device for construction machinery. 10. The interference preventing device for a construction machine according to claim 9, wherein the fourth computing means uses a command signal output to a flow control valve of the first front member as the correction operation signal to avoid the interference. An interference prevention device for a construction machine, which calculates a speed-up command value in a direction. 11. A construction machine interference prevention device according to claim 6, wherein the plurality of operating means are hydraulic pilot systems that output pilot pressure as the operating signals, and the first signal correcting means includes the first signal correcting means. The pilot pressure of the operating means of the front member is arranged in a path leading to the flow control valve of the first front member, and includes a proportional electromagnetic pressure reducing valve that reduces the pilot pressure according to the first limit value. The means is a proportional electromagnetic pressure reducing valve that outputs a pilot pressure according to the speed-up command value in the interference avoiding direction, and a path that guides the pilot pressure of the operating means of the second front member to the flow control valve of the second front member. A construction that is arranged and includes a shuttle valve that selects a higher pilot pressure of the proportional electromagnetic pressure reducing valve and a pilot pressure of the operating means of the second front member. Interference prevention device of 械. 12. The interference preventing device for a construction machine according to claim 11, further comprising means for detecting a pilot pressure of an operating means of the first front member, wherein the fourth computing means is a detected value of the pilot pressure. And a smaller one of the first limit values, and the selected value is used as the correction operation signal to calculate a speed-up command value in the interference avoidance direction. 13. The interference preventing device for a construction machine according to claim 1, wherein the first front member is a boom of a hydraulic excavator, the second front member is an arm of the hydraulic excavator, and the signal correcting means. The operation signal of the first front member corrected by the operation signal 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. Prevention device.