JP2793953B2 - Hydraulic excavator front controller - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a front control device for a hydraulic shovel, and more particularly, to automatically stop the operation of each front member when a bucket, which is a part of the front, approaches a driver's cab, thereby colliding the two. The present invention relates to a front control device of a hydraulic shovel provided with an interference prevention device for avoiding the problem.

[0002]

2. Description of the Related Art FIG. 3 is a side view of a conventional hydraulic shovel provided with an interference preventing device, FIG. 4 is a plan view of the hydraulic shovel, and FIG.

In these figures, reference numeral 1 denotes a traveling body, and 2 denotes a revolving body having an operator's cab 2a and disposed above the traveling body 1. The traveling body 1 and the revolving body 2 constitute a working machine body. doing. Reference numeral 3 denotes a first boom rotatably connected to the revolving unit 2, 4 denotes a second boom rotatably connected to a tip of the first boom 3, and 5 denotes a rotatable connection to a tip of the second boom. The arm 6 is a bucket rotatably connected to the tip of the arm 5, and the booms 3, 4, the arm 5 and the bucket 6 constitute a front 7. 8 is a boom cylinder for driving the first boom 3, 9 is an offset cylinder for driving the second boom 4, 10 is an arm cylinder for driving the arm 5, and 11 is a bucket cylinder for driving the bucket 6, which is shown in FIG. As described above, the second boom 4 translates the arm 5 and the bucket 6 in the lateral direction with respect to the first boom 3 by the offset cylinder 9. Each of these cylinders 8, 9, 10, and 11 is operated by an operation lever (not shown) arranged in the cab 2a. When an operator operates the operation lever as appropriate, the cylinders 8, 9, 10, and 11 are operated based on an instruction signal corresponding to the operation amount. The amount of pressure oil supplied to each of the cylinders 8, 9, 10, 11 is controlled.

[0004] Reference numeral 12 denotes a boom angle sensor provided near the connection between the revolving unit 2 and the first boom 3, and detects a relative angle between the revolving unit 2 and the first boom 3. 13 is the first
This is an offset angle sensor provided near the connection between the boom 3 and the second boom 4, the first boom 3 and the second boom 4
The relative angle between them, that is, the offset angle is detected. Further, an arm angle sensor 14 is provided near the connection between the second boom 4 and the arm 5, and detects a relative angle between the second boom 4 and the arm 5. These sensors 12, 1
Each angle signal detected by each of the cylinders 3 and 14 is input to a controller (not shown), and the controller calculates the coordinate position of the bucket 6 based on each angle signal. , 9,10,11
A stop signal for stopping the driving of the front 7 is output, and the operation of each part of the front 7 is automatically stopped.

That is, when the raising operation of the first boom 3 is performed in a state where the arm 5 is pulled to the maximum, the tip of the bucket 6 draws a locus indicated by the symbol T in FIG. An interference region where the bucket 6 and the cab 2a contact each other (the hatched portion in the figure) occurs. Therefore, a first interference risk zone Z1 indicated by a two-dot chain line is set in front of the cab 2a, and when the tip of the bucket 6 enters the first interference risk zone Z1, each cylinder is automatically stopped by a stop signal from the controller. Then, the tip of the bucket 6 is stopped in the first interference risk zone Z1 in front of the cab 2a. Further, when the bucket 6 is operated to perform a left offset operation so as to approach the cab 2a, an interference region that comes into contact with the bucket 6 is generated on the right side of the cab 2a, so that the two-dot chain line in FIG. Is set, and when the tip of the bucket 6 enters the second interference risk area Z2, each cylinder is automatically stopped by a stop signal from the controller.

Therefore, in the above-described conventional hydraulic excavator, when the bucket 6 approaches the first interference risk area Z1 in front of the cab 2a and the second interference risk area Z2 on the side,
Since the operation of each part of the front 7 is automatically stopped, and the contact between the bucket 6 and the cab 2a is avoided, damage to the machine can be prevented and the safety of the operator can be secured.

[0007]

By the way, in the above-mentioned conventional hydraulic excavator, the moving bucket 6 is in the cab 2.
Since the interference area contacting the driver's cab 2a exists in both the upper part and the lower part of the cab 2a, as shown in FIG. 3, the first interference risk area Z1 is set over a wide range from the upper part to the lower part in front of the cab 2a. There is a need to. Therefore, the safety of the operator is ensured, but the bucket 6 is
Becomes more invasive into the first interference risk zone Z1, and especially when the raising operation of the first boom 3 is performed, the bucket 6
Rises along the first interference risk area Z1, so that the bucket 6 is frequently stopped automatically in the first interference risk area Z1. Therefore, in such a case, the operator has to push the arm 5 to move the bucket 6 to the outside of the first interference risk zone Z1 and then to raise the first boom 3 again. There was a problem that operability was poor.

The present invention has been made in view of such circumstances of the prior art, and an object of the present invention is to provide a hydraulic shovel which is excellent in operability by reducing an interference risk area where a bucket is automatically stopped by an interference prevention device. It is to provide a front control device.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to provide a working machine body having an operator's cab, a first boom pivotally connected to the working machine body, and a first boom. A second boom movably connected laterally by an offset cylinder, an arm pivotally connected to the second boom, and a bucket rotatably pin connected to the arm. Operating means for instructing the operation of each front member constituted by the first and second booms, the arm and the bucket; and driving means for driving each front member based on an instruction signal from the operating means. Angle detecting means for detecting a relative angle between the work implement body and the front member, and a relative angle between the front members; and a signal from the angle detecting means. And an interference prevention device that calculates a coordinate value of the component and outputs a stop signal to the driving unit based on the calculation result, and the collision prevention device avoids contact between the bucket and the cab. In a front control device of a hydraulic excavator, an interference risk area where the bucket is automatically stopped by the interference prevention device is set only around the upper part of the cab, and the lower part of the bucket and the cab is mechanically operated by the front link mechanism. This is achieved by providing a configuration that does not cause any contact.

[0010]

When the bucket approaches the lower part of the driver's cab by the front operation, the bucket automatically stops around the lower part of the driver's cab because the link operation of each part of the front mechanically avoids the contact between the bucket and the lower part of the driver's cab. The front operation can be continued without performing. On the other hand, when the bucket approaches the upper part of the cab, the interference prevention device outputs a stop signal to the driving means when the bucket enters the danger area, and automatically stops the bucket in the danger area.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 and 2 illustrate an embodiment of a front control device for a hydraulic shovel according to the present invention. FIG. 1 is a side view of the hydraulic shovel, and FIG. 2 is a block diagram illustrating an entire configuration of an interference prevention device. Portions corresponding to FIGS. 3 to 5 described above are denoted by the same reference numerals.

As shown in FIG. 1, the hydraulic excavator according to the present embodiment has a notch 2b formed at a lower portion of an operator's cab 2a, and the interference between the bucket 6 and the lower portion of the operator's cab 2a is related to the link operation of the front 7. It is avoided mechanically. The portion where the tip of the bucket 6 and the operator cab 2a interfere with each other is limited only to the upper portion (hatched portion in the figure) of the operator cab 2a, and the first interference risk zone Z1 is set only around the upper portion of the operator cab 2a. The other configuration is basically the same as the above-described conventional example, and although not shown, a boom angle sensor 12, an offset angle sensor 13, an arm angle sensor 14, and the like are also provided.

In FIG. 2, reference numerals 12, 13, and 14 denote the aforementioned boom angle sensor, offset angle sensor, and arm angle sensor, and a relative angle signal θ1 between the front members detected by these sensors 12, 13, and 14. , Θ2,
θ3 is input to the arithmetic unit 15 built in the controller. The arithmetic unit 15 calculates the relative angle signals θ1, θ2,
A coordinate calculation unit 16 that calculates bucket tip coordinates from a predetermined location on the front 7, for example, the coordinates of the tip of the arm 5, based on θ3, and a first interference danger zone Z1 and a second The first and second danger area storage units 17 and 18 for setting the danger area Z2 and the bucket tip coordinates calculated by the coordinate calculation unit 16 are stored in the first or second danger area storage unit 17, 18
, A comparison operation unit 19 that outputs a prohibition signal according to the result, and a driving unit that inputs the prohibition signal from the comparison operation unit 19 and supplies hydraulic oil to each front member. For example, a drive control unit 20 that outputs a switching signal to a hydraulic drive circuit 21 is provided. The hydraulic drive circuit 21
Inputs, in addition to the switching signal from the drive control unit 20, an operation means for operating each front member arranged in the cab 2a, for example, an instruction signal from an operation lever 22;
The supply amount of hydraulic oil to each front member is controlled based on these signals. In calculating the tip coordinates of the bucket, for example, a coordinate system having the origin at the connection center between the revolving unit 2 and the first boom 3 is set in advance, and each angle signal θ is set.
The coordinate value of the tip of the arm 5 in this coordinate system may be calculated from 1, θ2, and θ3, and the coordinate value of the tip of the bucket 6 may be calculated from the coordinate value of the arm tip.

In the embodiment configured as described above, when the front operation is performed by the operation lever 22 at the time of excavation work or the like, the arithmetic unit 15 moves the boom angle sensor 12, the offset angle sensor 13, and the arm angle sensor 14 relative to each other. The angle signals θ1, θ2, and θ3 are input to the coordinate calculation unit 16, and the coordinate calculation unit 16 calculates the coordinates of the tip of the arm 5 from the relative angle signals θ1, θ2, and θ3. Calculate coordinates. Then, the comparison calculation unit 19 determines whether the bucket tip coordinates calculated by the coordinate calculation unit 16 are in the first or second interference risk area storage units 17 and 18, and determines whether the tip of the bucket 6 is in the first or second interference risk area storage unit 17 or 18. When it is determined that the cylinder is not located in the second danger area storage units 17 and 18, the switching signal is not output from the drive control unit 20 to the hydraulic drive circuit 21, and each of the cylinders 8, 9, 10 and 11 is operated by the operation lever 22. Is driven in accordance with the operation amount of. In addition, the tip of the bucket 6 has the first or second interference risk area storage unit 17,
If it is determined that the position is within the range, the drive control unit 20 outputs a predetermined switching signal to the hydraulic drive circuit 21 based on the prohibition signal input from the comparison operation unit 19, for example, by pulling the arm 5 or the first boom. 3, when the bucket 6 enters the first danger area Z1, the driving of the boom cylinder 8 and the arm cylinder 10 is automatically stopped, and the bucket 6 is left-offset to move the second interference danger area Z2.
, The driving of the offset cylinder 9 is automatically stopped.

Therefore, when the bucket 6 approaches the upper part of the cab 2a and enters the first danger area Z1, the bucket 6 is automatically stopped in the first danger area Z1 by the above-described interference prevention device. Despite operating the operation lever 22, the driving of the front 7 is stopped, and the collision between the bucket 6 and the upper part of the cab 2a is avoided. On the other hand, when the bucket 6 approaches the lower part of the cab 2a, the contact between the tip of the bucket 6 and the lower part of the cab 2a is notched 2b.
In this case, the bucket 6 does not collide with the lower part of the cab 2a.
Moreover, the first interference danger zone Z is provided around the lower part of the cab 2a.
Since 1 is not set, the bucket 6 can continue the front operation without being automatically stopped around the lower part of the cab 2a.

In the above embodiment, the case where the interference between the bucket 6 and the lower part of the cab 2a is avoided by the notch 2b has been described.
Instead of forming the front, it is also possible to shorten the link length of the front 7 to avoid interference.
Regardless of the posture, the contact between the bucket 6 and the lower part of the cab 2a may be mechanically avoided.

[0017]

As described above, according to the present invention,
The interference prevention area limits the bucket to automatic stop only around the upper part of the driver's cab. The interference between the bucket and the lower part of the driver's cab is mechanically avoided by the front link mechanism, so the bucket is avoided outside the interference risk area. It is possible to provide a hydraulic excavator front control device with less troublesome work and excellent operability.

[Brief description of the drawings]

FIG. 1 is a side view of a hydraulic excavator according to one embodiment of the present invention.

FIG. 2 is a block diagram showing an overall configuration of an interference prevention device provided in the hydraulic shovel of FIG.

FIG. 3 is a side view of a hydraulic excavator provided with a conventional interference prevention device.

FIG. 4 is a plan view of the excavator.

FIG. 5 is an explanatory diagram of an operation of a front provided in the hydraulic excavator of FIG. 3;

[Explanation of symbols]

 2 revolving superstructure 2a operator's cab 2b notch 3 first boom 4 second boom 5 arm 6 bucket 7 front 8 boom cylinder 9 offset cylinder 10 arm cylinder 12 boom angle sensor (angle detection means) 13 offset angle sensor (angle detection means) 14 Arm Angle Sensor (Angle Detector) 15 Arithmetic Unit 16 Coordinate Calculator 17 First Interference Danger Area Storage Unit 18 Second Interference Danger Area Storage Unit 19 Comparison Operation Unit 20 Drive Control Unit 21 Hydraulic Drive Circuit (Drive Unit) 22 Operation Lever (operation means) Z1 First danger area Z2 Second danger area

Continued on the front page (72) Inventor Akinori Shimasaki 20 Ishigane, Toyama City, Toyama Prefecture Fuji Koshiuchi Co., Ltd. (72) Inventor Takashi Matsuda 20 Ishikin, Toyama City, Toyama Prefecture Fuji Koshiuchi Co., Ltd. (56) References JP-A-5-272154 (JP, A) JP-A-3-217523 (JP, A) JP-A-4-333730 (JP, A) JP-A-4-254625 (JP, A) JP-A-4 −55530 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) E02F 9/24 E02F 3/43

Claims (2)

(57) [Claims] 1. A work machine main body having an operator's cab, a first boom rotatably connected to the work machine main body with a pin, and an offset cylinder connected to the first boom movably in a lateral direction. A second boom, an arm rotatably pin-connected to the second boom, a bucket rotatably pin-connected to the arm, the first and second booms and the arm, Operating means for instructing the operation of each front member constituted by the bucket, driving means for driving each front member based on an instruction signal from the operating means, and a relative position between the work implement body and the front member Angle detecting means for detecting an angle and a relative angle between the front members, and calculating the coordinate values of the front based on a signal from the angle detecting means, and based on the calculation result. An interference prevention device that outputs a stop signal to the driving means, and wherein the interference prevention device avoids contact between the bucket and the cab. Therefore, the interference danger area where the bucket automatically stops is set only around the upper part of the cab, and the bucket and the lower part of the cab are configured not to be mechanically contacted by the front link mechanism. Hydraulic excavator front control device. 2. The front control device for a hydraulic shovel according to claim 1, wherein a notch is provided at a lower portion of the cab to avoid contact with the bucket.