JPH07109749A - Front controller of hydraulic shovel - Google Patents

Abstract

PURPOSE:To decrease the frequency of moving a bucket automatically stopped in an interference dangerous region to the outside of the interference dangerous region and to promote controllability. CONSTITUTION:A first interference dangerous region Z1 is not set around the lower part of an operation room 2a, it is set only around the upper part thereof, and when a bucket 6 enters the first interference dangerous region Z1, after an interference prevention device calculates the front end co-ordinate of the bucket 6 based on relative angle signals 1, 2 and 3 from a boom angle sensor 12, an offset angle sensor 13 and an arm angle sensor 14, change-over signals stopping drive of cylinders 8, 9, 10 and 11 are outputted to a hydraulic driving circuit 21. The bucket 6 is automatically stopped in the first interference dangerous region Z1, Interference of the bucket 6 with the upper part of the operation room 2a is mechanically prevented by a notch 2b formed in the operation room 2a.

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 excavator, and in particular, when a bucket, which is a part of the front, approaches a driver's cab, the operation of each front member is automatically stopped to cause a collision between the two. The present invention relates to a front control device for a hydraulic excavator including an interference prevention device that avoids

[0002]

2. Description of the Related Art FIG. 3 is a side view of a conventional hydraulic excavator equipped with an interference preventing device, FIG. 4 is a plan view thereof, and FIG. 5 is an operation explanatory view of a front of the hydraulic excavator.

In these figures, 1 is a traveling body, 2 is a revolving structure having a driver's cab 2a and arranged above the traveling structure 1, and the traveling structure 1 and the revolving structure 2 constitute a working machine main body. is doing. Reference numeral 3 is a first boom rotatably connected to the revolving structure 2, 4 is a second boom rotatably connected to the tip of the first boom 3, and 5 is rotatably connected to the tip of the second boom. The arm 6 is a bucket rotatably connected to the tip of the arm 5, and the boom 7, 4 and the arm 5 and the bucket 6 form 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, 11 is a bucket cylinder for driving the bucket 6, and is shown in FIG. Thus, the second boom 4 moves the arm 5 and the bucket 6 in the lateral direction in parallel with the first boom 3 by the offset cylinder 9. Each of these cylinders 8, 9, 10, 11 is operated by an operation lever (not shown) arranged in the cab 2a, and when the operator appropriately operates the operation lever, based on an instruction signal according to the operation amount, The amount of pressure oil supplied to each cylinder 8, 9, 10, 11 is controlled.

Reference numeral 12 denotes a boom angle sensor provided in the vicinity of a connecting portion between the swing body 2 and the first boom 3, and detects a relative angle between the swing body 2 and the first boom 3. Also, 13 is the first
An offset angle sensor provided in the vicinity of a connecting portion between the boom 3 and the second boom 4, and the first boom 3 and the second boom 4 are provided.
The relative angle between them, that is, the offset angle is detected. Furthermore, 14 is an arm angle sensor provided in the vicinity of the connecting portion between the second boom 4 and the arm 5, and detects the relative angle between the second boom 4 and the arm 5. These sensors 12, 1
Each angle signal detected by 3, 14 is input to a controller (not shown), the controller calculates the coordinate position of the bucket 6 based on each angle signal, and each cylinder 8 when the bucket 6 approaches the cab 2a. , 9, 10, 11
A stop signal for stopping the driving of the front 7 is output to automatically stop the operation of each part of the front 7.

That is, when the first boom 3 is lifted while 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 driver's cab 2a contact each other (hatched portion in the figure) occurs. Therefore, a first interference danger area Z1 indicated by a chain double-dashed line is set in front of the cab 2a, and when the tip of the bucket 6 enters the first interference danger area 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 area Z1 in front of the operator's cab 2a. Further, when the bucket 6 is left-offset so as to approach the cab 2a, an interference region where the bucket 6 contacts the cab 2a occurs on the right side of the cab 2a. The second interference danger area Z2 is set and each cylinder is automatically stopped by a stop signal from the controller even when the tip of the bucket 6 enters the second interference danger area Z2.

Therefore, in the above-mentioned conventional hydraulic excavator, when the bucket 6 approaches the first interference danger area Z1 in front of the cab 2a and the second interference danger 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 operator's 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 has the cab 2
Since the interference area that contacts a exists in both the upper part and the lower part of the operator's 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 operator's cab 2a. There is a need to. Therefore, the safety of the operator is secured, but the bucket 6
Is frequently invaded into the first interference risk area Z1, and particularly when the raising operation of the first boom 3 is performed, the bucket 6
Rises along the first interference risk region Z1, so that the bucket 6 has many opportunities to automatically stop in the first interference risk region Z1. Therefore, in such a case, the operator must push the arm 5 to once move the bucket 6 to the outside of the first interference risk area Z1, and then perform the raising operation of the first boom 3 again. There was a problem of poor operability.

The present invention has been made in view of the above-mentioned circumstances of the prior art, and an object thereof is to reduce the danger area of interference in which the bucket is automatically stopped by the interference prevention device and to provide a hydraulic excavator having excellent operability. To provide a front control device.

[0009]

An object of the present invention described above is to provide a working machine main body having a cab, a first boom rotatably pin-connected to the working machine main body, and a first boom. Second boom movably connected in a lateral direction by an offset cylinder, an arm rotatably pinned to the second boom, and a bucket rotatably pinned to the arm. And operating means for instructing the operation of each front member composed of the first and second booms, the arm and the bucket, and a drive means for driving each front member based on an instruction signal from the operating means. An angle detecting means for detecting a relative angle between the working machine main body and the front member and a relative angle between the front members, and the angle detecting means based on a signal from the angle detecting means. And an interference prevention device that outputs a stop signal to the drive unit based on the calculation result, and the interference prevention device avoids contact between the bucket and the cab. In a front control device of a hydraulic excavator, an interference danger area where the bucket automatically stops by the interference prevention device is set only around the upper part of the cab, and the bucket and the lower part of the cab are machined by the front link mechanism. It is achieved by configuring so as not to make physical contact.

[0010]

[Operation] When the bucket approaches the lower part of the cab by the front operation, the link operation of each part of the front mechanically avoids the contact between the bucket and the lower part of the cab, so the bucket automatically stops around the lower part of the cab. You can continue to operate the front desk without doing this. On the other hand, when the bucket approaches the upper part of the driver's cab, the interference prevention device outputs a stop signal to the drive means at the time when the bucket enters the interference danger area, and automatically stops the bucket in the interference danger area.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 are diagrams for explaining an embodiment of a front control device for a hydraulic excavator according to the present invention. FIG. 1 is a side view of the hydraulic excavator, and FIG. 2 is a block diagram showing an overall configuration of an interference prevention device. The same reference numerals are given to the portions corresponding to those in FIGS.

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

In FIG. 2, reference numerals 12, 13, and 14 denote the boom angle sensor, the offset angle sensor, and the arm angle sensor described above. The relative angle signal θ1 between the front members detected by these sensors 12, 13, 14 is shown. , Θ2
θ3 is input to the arithmetic unit 15 incorporated in the controller. This arithmetic unit 15 has relative angle signals θ1, θ2.
A coordinate calculation unit 16 for calculating bucket tip coordinates from the coordinates of the tip of the arm 5 based on θ3, for example, the coordinates of the tip of the arm 5, and the first interference risk area Z1 and the second interference danger area Z1 at the upper front and right sides of the cab 2a, respectively. The first interference danger area storage unit 17 and the second interference danger area storage unit 18 that set the interference danger area Z2, and the bucket tip coordinates calculated by the coordinate calculation unit 16 are the first or second interference danger area storage unit 17, 18
Whether or not it is inside, a comparison operation unit 19 that outputs a prohibition signal according to the result, and a drive 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 the hydraulic drive circuit 21 is provided. The hydraulic drive circuit 21
In addition to the switching signal from the drive control unit 20, an instruction signal from an operating means for operating each front member arranged in the cab 2a, for example, an operation lever 22, is input.
The amount of hydraulic oil supplied to each front member is controlled based on these signals. When calculating the bucket tip coordinates, for example, a coordinate system whose origin is the connection center between the revolving unit 2 and the first boom 3 is set in advance, and each angle signal θ is set.
1, θ2, θ3, the coordinate value of the tip of the arm 5 in this coordinate system may be calculated, 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 front operation is performed by the operation lever 22 during excavation work, the arithmetic unit 15 causes the boom angle sensor 12, the offset angle sensor 13, and the arm angle sensor 14 to move relative to each other. The angle signals θ1, θ2, θ3 are input to the coordinate calculation unit 16, the coordinate calculation unit 16 calculates the coordinates of the tip of the arm 5 from the relative angle signals θ1, θ2, θ3, and then the tip of the bucket 6 is calculated from the coordinate of the arm tip. Calculate the 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 danger area storage units 17 and 18, and the tip of the bucket 6 is the first position. If it is determined that the cylinder is not in the second interference risk area storage unit 17, 18, the switching signal is not output from the drive control unit 20 to the hydraulic drive circuit 21, and the cylinders 8, 9, 10, 11 are operated by the operation lever 22. It is driven according to the operation amount of. In addition, the tip of the bucket 6 has the first or second interference danger area storage unit 17,
If it is determined that the position is within 18, 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 calculation unit 19, and, for example, pulls the arm 5 or the first boom. When the bucket 6 has entered the first interference danger area Z1 by raising 3, the drive of the boom cylinder 8 and the arm cylinder 10 is automatically stopped, and the bucket 6 is moved to the second interference danger area Z2.
When it enters the position, the drive 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 interference risk area Z1, the bucket 6 is automatically stopped in the first interference danger area Z1 by the above-mentioned 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 portion of the cab 2a is avoided. On the other hand, when the bucket 6 approaches the lower part of the operator's cab 2a, the contact between the tip of the bucket 6 and the lower part of the operator's cab 2a is notched 2b.
In this case as well, the bucket 6 does not collide with the lower portion of the cab 2a because it is mechanically avoided.
Moreover, the first interference danger area Z is formed around the lower part of the operator's cab 2a.
Since 1 is not set, the bucket 6 can continue the front operation as it is without automatically stopping around the lower portion of the operator's cab 2a.

In the above embodiment, the case where the interference between the bucket 6 and the lower portion of the operator's cab 2a is avoided by the notch 2b has been described, but the notch 2b is provided in the lower portion of the operator's cab 2a.
Instead of forming the link, it is possible to shorten the link length of the front 7 to avoid interference.
The contact between the bucket 6 and the lower portion of the operator's cab 2a may be mechanically avoided regardless of the posture.

[0017]

As described above, according to the present invention,
Since the bucket is automatically stopped by the interference prevention device, only the area around the upper part of the operator's cab is stopped, and the interference between the bucket and the lower part of the operator's cab is mechanically avoided by the front link mechanism. It is possible to provide a front control device for a hydraulic excavator that has excellent operability and reduces troublesome work.

[Brief description of drawings]

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

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

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

FIG. 4 is a plan view of the hydraulic excavator.

5 is an operation explanatory view of the front of the hydraulic excavator of FIG.

[Explanation of symbols]

 2 Revolving structure 2a Driver's cab 2b Notch 3 1st boom 4 2nd 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 Detection Means) 15 Arithmetic Device 16 Coordinate Calculator 17 First Interference Hazardous Area Memory 18 Second Interference Hazardous Area Memory 19 Comparison Calculator 20 Drive Controller 21 Hydraulic Drive Circuit (Drive Means) 22 Operation Lever (operating means) Z1 First interference danger area Z2 Second interference danger area

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akinori Shimamae 20 Ishigane Co., Ltd., Toyama City, Toyama Prefecture (72) Inventor Takashi Matsuda 20 Ishigane Co., Ltd., Toyama City, Toyama Prefecture

Claims (2)

[Claims] 1. A working machine main body having a driver's cab, a first boom pivotally connected to the working machine main body, and a laterally movably connected to the first boom by an offset cylinder. A second boom, an arm rotatably pin-connected to the second boom, a bucket rotatably pin-connected to the arm, and the first and second booms and the arm. An operating means for instructing the operation of each front member composed of a bucket, a driving means for driving each front member based on an instruction signal from the operating means, and a relative position between the working machine body and the front member. An angle detecting means for detecting an angle and a relative angle between the front members, and a coordinate value of the front is calculated based on a signal from the angle detecting means, and based on the calculation result. A front control device for a hydraulic excavator, comprising: an interference prevention device that outputs a stop signal to the drive means based on the above; and 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 so as not to mechanically contact with each other by the front link mechanism. Front control device for hydraulic excavator. 2. The front control device for a hydraulic excavator according to claim 1, wherein a notch for avoiding contact with the bucket is provided in a lower portion of the operator's cab.