JPH0794733B2 - Excavation control device for excavating machine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an excavation control device for an excavating machine such as a hydraulic excavator and a hydraulic backhoe.

[Conventional technology]

A conventional excavation control device of this type is, for example, Japanese Patent Publication No.
-40121, JP-A-55-126619, and JP-A-61-83727
There is one shown in each publication of the issue.

Among the above-mentioned conventional examples, the one disclosed in Japanese Patent Publication No. 52-40121 discloses a model link mechanism that has the same movement as the working machine and is similar to the working machine, and is operated by the model link mechanism. The excavation depth limiting limiter for limiting the excavation depth of the vehicle and the repose angle limiting limiter for limiting the excavation exceeding the repose angle of the working machine are installed in a location visible to the driver, and follow the working machine. The excavation state of the working machine can be easily grasped by observing the moving model link mechanism, and the excavation exceeding the predetermined excavation depth and repose angle is automatically restricted.

Further, the one disclosed in Japanese Patent Laid-Open No. 55-126619 prevents the excessive excavation by issuing an alarm and notifying the driver when excessively excavating more than the final finishing straight line in the slope excavation work. It is the one.

Further, the one disclosed in Japanese Patent Laid-Open No. 61-83727 also calculates the slope during formation in a work involving slope formation such as slope excavation work and calculates the slope between this slope and a predesignated reference slope. When the deviation deviates from the predetermined range, an alarm signal is output, and the driver is informed acoustically of the deviation from the reference gradient.

[Problems to be Solved by the Invention]

Among the above-mentioned conventional examples, in the one disclosed in Japanese Patent Publication No. 52-40121, since there is a model link mechanism similar to this in addition to the working machine, the entire apparatus becomes complicated, and the reliability decreases accompanying it. There was such a problem.

Also, due to its configuration, when excavation exceeds a predetermined excavation depth, the working machine will stop at that position.Therefore, this stopped state is artificially released to make the working machine operable. Then, it was necessary to set the excavation depth again and perform the subsequent excavation work.

Therefore, in particular, when excavating along a predetermined target excavation depth, it is necessary to be careful not to exceed the target excavation depth. Since it is necessary to release the stopped state of the working machine and set the excavation depth, the work becomes complicated and it is difficult to improve the excavation accuracy.

Further, in Japanese Patent Application Laid-Open No. 55-126619 and Japanese Patent Application Laid-Open No. 61-83727, a buzzer, an alarm lamp, etc. are used when excavating with deviation from a final finishing straight line or a standard gradient. The warning means is used to warn the driver, but the engine sound of the excavating machine is too loud to be noticed, or the driver often pays attention to the cutting edge of the work machine and does not notice it.

Furthermore, even if an alarm is noticed, the driver has to judge the direction in which the working air should be actuated each time and operate the work implement operating means, which makes the work complicated and it is difficult to improve the excavation accuracy. Met.

The present invention has been made in view of the above, and in an excavating machine such as a hydraulic excavator and a hydraulic backhoe, a portion shallower than a designated excavation surface can be freely excavated, but a portion deeper than a designated excavation surface cannot be excavated. An object of the present invention is to provide an excavation control device for an excavating machine, which is configured to solve the above problems by limiting the movement of the working machine.

[Means for Solving the Problems]

In order to achieve the above object, an excavation control device for an excavating machine according to the present invention includes a boom whose one end is rotatably supported by a vehicle body, an arm which is pivotally supported by the other end of the boom, and the other end of the arm. In a configuration including a bucket pivotally supported on the cylinder and a cylinder for driving the bucket, an angle detector that is provided at each rotation fulcrum of the boom, the arm, and the bucket, and outputs a signal according to the rotation angle thereof, The working machine blade edge position calculating means for calculating the current position of the bucket blade edge point based on the signal from the angle detector and outputting the corresponding position signal, and the excavation depth and the excavation angle that define the specified excavation surface are set. Based on the signal from the digging depth / digging angle setting means, the signal from the working machine blade edge position calculating means, and the digging depth and digging angle set by the digging depth / digging angle setting means, with respect to the designated digging surface And a comparison calculation means for outputting a command signal according to a case where the bucket blade tip position is located at a portion shallower than the designated excavation surface and a case other than that. Based on the command signal from the, when the bucket blade tip point is located in a portion shallower than the specified excavation surface, the movement of the bucket blade tip point is not limited, and in other cases, the bucket blade tip point moves in a direction deeper. And a working machine direction determination calculation means for outputting a signal for stopping the movement of the cylinder, and each cylinder can be operated by operating the operation valve connected to each cylinder according to the signal from the working machine direction determination calculation means. It is configured to stop operation.

[Work]

The relation between the position of the bucket blade tip point calculated by the work machine blade edge position calculation means and the excavation surface previously designated by the excavation depth / excavation angle setting means is compared by the comparison calculation means,
By inputting a command signal based on the comparison result to the work implement direction determination calculation means, an operable signal or an operation stop signal for the boom, arm, and bucket is output from the work implement direction determination calculation means, and The operation valve is connected to each cylinder to control the operation of each cylinder to control the movement of the work machine.

[Examples] Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

FIG. 3 shows a schematic configuration of the hydraulic excavator. A vehicle body, for example, an upper swing body 2 is supported on the traveling body 1, one end of a boom 3 is pivotally supported by the swing body 2, and the other parts of the boom 3 are supported. An arm 4 is pivotally supported at the end, and a bucket 5 is pivotally supported at the other end of the arm 4. The boom 3, the arm 4, and the bucket 5 are a boom cylinder 6, an arm cylinder 7, and a bucket cylinder. Each of them is rotationally driven by 8.

Here, the length, angle, etc. of each part of the working machine are defined as shown in FIG. That is, the point O is the boom rotation fulcrum, the point A is the arm rotation fulcrum, the point B is the bucket rotation fulcrum, the point C is the bucket blade tip point, and the vehicle body horizontal axis passing through this point O is X.
L1; length between points O and A L2; length between points A and B L3; length between points B and C α; Y Angle formed by axis and line segment OA (boom angle) β; Angle formed by extension line of line segment OA and line segment AB (arm angle) γ; Angle formed by extension line of line segment AB and line segment BC ( Bucket angle).

Now, assuming that the position of the bucket blade tip point C with respect to the boom rotation fulcrum O is (Xc, Yc), this position (Xc, Yc) is expressed by the following equation: Xc = L1 · SINα + L2 · SIN (α + β) + L3 · SIN (α + β + γ)… ( 1) Yc = L1 · COSα + L2 · COS (α + β) + L3 · COS (α + β + γ) (2)

Further, in FIG. 4, when the point P is the intersection of the designated excavation surface and the Y-axis, and the point D is the intersection of the perpendicular from the bucket blade tip point C to this excavation surface, h; between points O and P Length (excavation depth) However, h is positive when the point P is located above O and is negative when the point P is located below the point O.

θ; Angle of excavation plane PD with respect to X axis (excavation angle) u: Given the length between points D and C (distance from excavation plane to bucket blade tip point), excavation plane is expressed by the following formula Y = tan θ · X + h… It is represented by (3).

Therefore, the movement of the work machine will be described separately for the case of excavating a portion shallower than the excavation surface and the case of excavating a portion on the excavation surface or deeper than the excavation surface.

First, when excavating a part shallower than the excavation surface, Yc> tan θ · Xc + h (4) is established from the above equations (1), (2), and (3), and in this case, the movement of the working machine is limited. Freely drilling without

Next, when trying to excavate a part on the excavation surface or deeper than the excavation surface, similarly, from the above equations (1), (2), and (3), Yc ≤ tan θ · Xc + h (5) holds. First, by controlling the movements of the boom 3, the arm 4, and the bucket 5 in accordance with the operating direction of the work machine at that time, excavation of a portion deeper than the excavation surface is limited.

That is, by examining the change in the distance u from the excavation surface to the bucket blade tip point C with respect to the change in the boom angle α, the arm angle β, and the bucket angle γ, the operating direction of the working machine at that time is determined, and The movement of the work machine is controlled based on the determination result. Specifically:

The distance u from the excavation surface to the bucket blade tip point C is obtained by the following equation u = L1 · COS (α + θ) + L2 · COS (α + β + θ) + L3 · COS (α + β + γ + θ) + h · COSθ (6), and this distance u is When the bucket blade tip point C is located in a portion shallower than the excavation surface u> 0 When the bucket blade tip point C is located in a portion deeper than the excavation surface u <0 When the bucket blade tip point C is located in the excavation surface Each code of u = 0 is taken.

Therefore, by differentiating the above equation (6) by α, β, and γ, the following equations du / dα = -L1 · SIN (α + θ) -L2 · SIN (α + β + θ) -L3 · SIN (α + β + γ + θ) (7) ) Du / dβ = −L2 · SIN (α + β + θ) −L3 · SIN (α + β + γ + θ) (8) du / dγ = −L3 · SIN (α + β + γ + θ) (9) is obtained.

Here, the du / dα, du / dβ, du / dγ mean the rate of change of the distance u from the excavation surface to the bucket blade tip point C with respect to the changes of the boom angle α, the arm angle β, and the bucket angle γ, respectively. The detailed meaning will be described below with reference to FIG. 5 for explaining changes in u with respect to α, β and γ.

When du / dα, du / dβ, du / dγ> 0, when α, β, γ increases, that is, when the boom 3, the arm 4, and the bucket 5 operate downward or in the excavating direction, the above distance u Is increased, that is, the bucket blade tip point C moves in a direction shallower than the current position. In this case, α,
The relationship between β, γ and u is as shown in FIG.

When du / dα, du / dβ, du / dγ <0, when α, β, γ is increased, that is, when the boom 3, the arm 4, and the bucket 5 operate downward or in the excavation direction, the above distance u Is decreased, that is, the bucket blade tip point C moves in a direction deeper than the current position. In this case, α,
The relationship between β, γ and u is as shown in FIG. 5 (B).

Furthermore, when du / dα, du / dβ, du / dγ = 0, α, β, γ
The distance u becomes temporarily constant regardless of the increase of
That is, the relationship between α, β, γ and u becomes like the minimum part in FIG. 5 (C).

Therefore, for a portion shallower than the designated excavation surface (formula (4) above is satisfied), the excavation can be freely performed without restricting the movement of the working machine as described above, and the excavation designated by the bucket blade tip point C is performed. When the surface (PD) is reached (Equation (5) above is satisfied), the movement of the work machine is restricted as shown in the table below, so that only the portion shallower than the designated excavation surface is excavated and designated. Finishing the excavated surface is the principle of the present invention.

Next, a control configuration example of the present invention based on the above principle will be described.

FIG. 1 is a block diagram showing an embodiment of the present invention, in which 9 is a boom operating lever, 10 is an arm operating lever, and 11 is a bucket operating lever, all of which are provided in a vehicle body, for example, in a driver's cab of the upper swing body 2. It is provided.

Reference numeral 12 is a boom raising stop circuit, and 13 is a boom lowering stop circuit. These are provided between the boom operation lever 9 and a boom operation valve 19 which is switched and controlled by the operation of the boom operation lever 9, Based on the principle of the invention, each boom 3 receives a control signal from a controller 18 described later.
The boom operation valve 19 is controlled so as to stop the upward movement or the downward movement.

Further, 14 is an arm excavation stop circuit, 15 is an arm dump stop circuit, these are provided in the middle of the arm operation lever 10 and the arm operation valve 20 which is switch-controlled by the operation of the arm operation lever 10, Upon receiving a control signal from the controller 18, the arm operation valve 20 is controlled so as to stop the movement of the arm 4 in the excavation direction or the dump direction.

Further, 16 is a bucket excavation stop circuit, and 17 is a bucket dump stop circuit.
And a bucket operating valve 21 that is switched and controlled by operating the bucket operating lever 11, and receives a control signal from the controller 18 to stop the movement of the bucket 5 in the excavating direction or the dumping direction. To control the bucket operation valve 21.

The boom operation valve 19, the arm operation valve 20, and the bucket operation valve 21 are hydraulically expanded and contracted by the switching control of the operation valves 19, 20, 21 as described above. , An arm cylinder 7 and a bucket cylinder 8 are respectively connected to drive the boom 3, the arm 4 and the bucket 5 respectively.

Next, at the boom rotation fulcrum O, the arm rotation fulcrum A, and the bucket rotation fulcrum B, the rotation amounts of the boom 3, the arm 4, and the bucket 5, that is, the boom angle for detecting the boom angle α. A detector 22, an arm angle detector 23 for detecting the arm angle β, and a bucket angle detector 24 for detecting the bucket angle γ are respectively provided, and the boom angle α, the arm angle β, and A signal corresponding to the current value of the bucket angle γ is output and input to the controller 18.

The configuration of the controller 18 will be described next.

Numeral 25 is a working machine blade edge position calculating means, which inputs a signal corresponding to the present values of the boom angle α, the arm angle β and the bucket angle γ to the boom from equations (1) and (2). The present position of the bucket blade tip point CN with respect to the turning point O (X
c, Yc) is calculated, and the corresponding position signal is output and input to the comparison calculation means 27 described later.

Reference numeral 26 denotes an excavation depth / excavation angle setting means, which sets an excavation depth h and an excavation surface θ which define an excavation surface to be designated, and a comparison calculation means.
It is designed to input to 27.

The comparison calculation means 27 is based on the signal corresponding to the current position (Xc, Yc) of the bucket blade tip point C and the excavation depth h and the excavation angle θ input from the excavation depth / excavation angle setting means 26. , Comparing the positional relationship of the bucket blade tip point with respect to the designated excavation surface, whether the bucket blade tip point C is located at a portion shallower than the designated excavation surface (formula (4) above is established), or is designated. Further, it is determined whether or not it is located on the excavation surface or in a portion deeper than this (formula (5) is established), and a command signal corresponding to each case is input to the work machine direction determination calculation means 28.

The working machine direction determination calculation means 28 receives the command signal and controls the movements of the bucket blade tip point C in response to the current position of the bucket blade tip point C and the respective operating directions of the boom 3, the arm 4 and the bucket 5 at that time. For outputting the control signal for enabling the operation of the above equations (4), and when the above equation (5) is satisfied, the above signals 7), (8), A signal for stopping the operation or a signal for enabling the operation is output according to the sign of the value obtained by the equation (9) and is input to the working machine stop circuit 29.

FIG. 2 shows a hydraulic circuit diagram of the device of the present invention, where 30 is a pilot pump, which is a boom operating valve 19, an arm operating valve 20,
And supplying a pilot pressure for switching the bucket operation valve 21, and in the middle of this pilot pressure supply pipe,
In order to control the supply of pilot pressure for switching each of these operating valves 19, 20, 21, in order to control the boom raising pilot valve 31, the boom lowering pilot valve 32, and the arm operating lever 10 that interlock with the boom operating bar 9. A pilot valve 33 for arm excavation and a pilot valve 34 for arm dump, and a bucket excavation pilot valve 35 and a bucket dump pilot valve 36 that interlock with the bucket operation lever 11 are provided.

A boom raising stop valve 37 is provided between the boom raising pilot valve 31 and the boom operating valve 19, and a boom lowering stop valve 38 is provided between the boom lowering pilot valve 32 and the boom operating valve 19.
However, an arm excavation stop valve 39 is provided between the arm excavation pilot valve 33 and the arm operation valve 20, and an arm dump stop valve is provided between the arm dump pilot valve 34 and the arm operation valve 20.
40 is a pilot valve for bucket excavation 35 and a bucket operating valve
A bucket excavation stop valve 41 is provided between the two, and a bucket dump stop valve 42 is provided between the bucket dump pilot valve 36 and the bucket operation valve 21, and each of these stop valves 37, 38, 39 is provided. , 40, 41, 42 can be individually switched by a control signal output from the working machine direction determination calculation means 28 of the controller 18.

Reference numeral 43 is a main pump. The boom operation valve 19, the arm operation object 20, and the bucket operation valve 21 provided in the middle of the hydraulic supply line of the main pump 43 are the pilot valves described above.
31,32,33,34,35,36 or stop valves 37,38,39,40,41,42
Of the boom cylinder 6, the arm cylinder 7, and the bucket cylinder 8 which are switched by the supply of the pilot pressure associated with the switching of the control valves 19, 20 and 21 respectively.
By supplying pressure oil to these cylinders 6,7,8
To expand and contract.

The operation of this structure will be described with reference to FIG. 8 which shows a flowchart for explaining the operation of the controller 18.

First, the excavation depth h and excavation angle θ are input to the excavation depth / excavation angle setting means 26 to specify the excavation surface to be excavated (step 100 in FIG. 8).

Next, by operating the boom operation lever 9, the arm operation lever 10, and the bucket operation lever 11, the pilot valves 31, 3 interlocking with the operation levers 9, 10, 11 respectively.
2, 33, 34, 35, 36 are switched to control the supply of pilot pressure supplied from the pilot pump 30 to each stop valve 37, 38, 39, 40, 41, 42 provided in the work machine stop circuit 29. .

That is, when the boom operation lever 9 is operated to the boom raising side, the boom raising pilot valve 31 is switched and the pilot pressure is supplied to the boom raising stop valve 37, but the boom lowering pilot valve 32 is not switched and the pilot pressure is kept at the boom. Not supplied to the stop valve 38.

Conversely, if you operate the boom operating lever 9 to the boom lower side,
The boom lowering pilot valve 32 is switched so that the pilot pressure is supplied to the boom lowering stop valve 38 and not to the boom raising stop valve 37.

The same applies to the supply of pilot pressure to each stop valve 39, 40, 41, 42 corresponding to the operation of the arm operation lever 10 and the bucket operation lever 11.

At the start of the excavation work, since the bucket blade tip point C is located at a portion shallower than the excavation surface, the boom angle α, the arm angle detector 23, and the bucket angle detector 24 detect the boom angle α and the arm, respectively. The position (Xc, Yc) of the bucket blade tip point C is calculated by the working machine blade tip position calculating means 25 according to the values of the angle β and the bucket angle γ (step 110 in FIG. 8), and further the comparison calculating means 27 calculates Yc. By outputting a command signal according to> tan θ · Xc + h (step 120 in FIG. 8), a signal that enables the boom 3, the arm 4, and the bucket 5 to operate in the working machine direction determination calculation means 28 (hereinafter, operation A possible signal) is output (steps 132, 142, 152 in FIG. 8).

When the operation enable signal is input to the work machine stop circuit 29, the stop valves 37, 38, 39, 40, 41, 42 described above are connected to the stop valves 37, 38, 39, 40, 41, 42 from the pilot valves 31, 32, 33, 34, 35, 36 respectively. The pilot pressure can be supplied to each operation valve 19,2021 provided corresponding to the pilot valve.

Therefore, following the operation of the boom operation lever 9, the arm operation lever 10, and the bucket operation lever 11, the corresponding operation valves 19, 20, 21 are switched by the pilot pressure,
The boom cylinder 6, the arm cylinder 7, and the bucket cylinder 8 are hydraulically expanded and contracted to freely excavate.

When the excavation is continued in this way and the bucket blade tip point C finally reaches the excavation surface, the position of the bucket blade tip point C is calculated in the same manner as described above (step 110 in FIG. 8), and Yc ≦ from the comparison calculation means 27. A command signal corresponding to tan θ · Xc + h is output (Fig. 8, step 12).
0).

Then, in the working machine direction determination calculation means 28, du / dα, du / dβ,
du / dγ is calculated (Fig. 8, step 81, step 82, step 83, u is the distance from the excavation surface to the bucket blade tip point), and the operation of the working machine is further determined according to the sign of these values. A signal to stop (hereinafter referred to as a stop signal),
Alternatively, an operable signal is output (step 131 in FIG. 8,
132,133,141,142,143,151,152,153).

For example, in the case of excavating the excavation surface as shown in FIG. 9, considering the case where the bucket blade tip point C reaches the excavation surface, α is determined from the operating directions of the boom 3, arm 4, and bucket 5 up to that point. , U, corresponding to the increase in all of β, γ, the values of du / dα, du / dβ, du / dγ are all negative, and the boom down stop signal, arm An excavation stop signal and a bucket excavation stop signal are output (steps 133, 143, 153 in FIG. 8).

Then, the boom lowering stop valve 38, the arm excavation stop valve 39, and the bucket excavation stop valve 41 are switched to change the boom operation lever 9, the arm operation lever 10, and the bucket operation lever.
Each operation valve 19,20,21 returns to the neutral position without following the operation of 11, and the boom lowering, arm excavation, and bucket excavation movements stop, and the bucket blade tip point C as shown in FIG. Does not move deeper than that.

Therefore, in this case, the boom operation lever 9 is operated to the raising side, and the arm operation lever 10 and the bucket operation lever are operated.
11 can still excavate only the upper part from the excavation surface by operating each to the excavation side.

That is, the specified excavation surface can be finally excavated by repeating a series of operations of excavation, excavation stop, and upper excavation of the excavation surface.

Although not shown, the values of du / dα, du / dβ, and du / dγ are positive, negative, and 0 depending on the position of the bucket blade tip point with respect to the excavation surface.
However, not all of these values may be positive, negative, or 0 at the same time, but even in those cases, the excavation surface can be excavated according to the above operation.

As described above, in this embodiment, the portion shallower than the designated excavation surface is freely excavated, and the movement of the work implement is restricted so that the portion deeper than the excavation surface cannot be excavated. It is possible to excavate the excavation surface by continuing to excavate without paying attention to the position of the bucket blade tip point with respect to, which reduces the burden on the driver, improves work efficiency and excavation accuracy, and improves the control system of conventional excavating machines. It only needs a little improvement, and the whole device is simple and reliable.

6 and 7 show another embodiment of the present invention, in which an electronically controlled valve driven by a valve driver is used as an operation valve instead of the pilot valve, the stop valve and the operation valve in the previous embodiment. 6 and 7. FIG. 6 is a block diagram and FIG. 7 is a hydraulic circuit diagram. The same parts as those in FIGS. 1 and 2 are designated by the same reference numerals and the description thereof will be omitted.

That is, in FIG. 6, for the boom operation lever that outputs a signal for controlling a valve driver 54 to 59 described later according to each operation angle of the boom operation lever 9, the arm operation lever 10, and the bucket operation lever 11. Angle sensor 51,
An angle sensor 52 for the arm operation lever and an angle sensor 53 for the bucket operation lever are provided between the corresponding operation levers and the valve driver.

Further, the operation enable signal and the operation stop signal for the boom 3, the arm 4, and the bucket 5 output from the work machine direction determination calculation means 28 are also input to the corresponding valve driver 54 to 59 in the work machine direction. The judgment calculation means 28 and the valve driver 54 are connected to each other.

Among these, the boom driver valve driver 54 receives a signal from the boom operation lever angle sensor 51, the operation enable signal and the operation stop signal for boom lowering, and the boom lift valve driver 55 the boom operation lever angle sensor.
The signal from 51, the operable signal for boom raising and the operation stop signal are input respectively, and by driving these valve drivers 54 or 55, electronic control valves provided corresponding to both valve drivers 54 and 55 are provided. The boom operating valve 60 is switched to the lowered position or the raised position, or such switching is stopped.

Similarly, the arm dump valve drive 56 receives a signal from the arm operation lever angle sensor 52 and the arm dump operation enable signal and the operation stop signal, and the arm excavation valve driver 57 receives the arm operation lever angle sensor 52 from the arm operation lever angle sensor 52. Signal and an operation enable signal and an operation stop signal for arm excavation are input to switch the arm operation valve 61, which is an electronically controlled valve provided correspondingly, or stop the switching.

Further, the bucket dump valve driver 58 receives a signal from the bucket operation lever angle sensor 53 and the bucket dump operation enable signal and the operation stop signal. The bucket excavation valve driver 59 receives the signal from the bucket operation lever angle sensor 53. A signal, an operable signal for bucket excavation, and an operation stop signal are input to switch the bucket operation valve 62, which is an electronically controlled valve corresponding thereto, or stop switching.

Next, FIG. 7 is a hydraulic circuit diagram for realizing the embodiment shown in the block diagram of FIG. 6, in which the angle sensors 51, 52, 53 for the respective operating levers and the respective operating valves corresponding thereto are shown. 60,61,
A controller 63 provided between 62 and 62 is for controlling switching of electronic control valves used as these operation valves, working machine blade edge position calculating means 25, excavation surface setting means 26,
The comparison calculation means 27, the working machine direction determination calculation means 28, and the valves 59 in the valve drivers 54 are combined as described above.

Also in the configuration shown in FIGS. 6 and 7, the position (Xc, Yc) of the bucket blade tip point calculated by the working machine blade edge position calculating means 25 and the excavation surface designated in advance by the excavation surface setting means 26 Is compared by the comparison calculation means 27, and a command signal based on the comparison result is input to the work machine direction determination calculation means 28, whereby an operable signal or an operation stop signal for the boom 3, the arm 4, and the bucket 5 is obtained. Is output from the working machine direction determination calculation means 28 to selectively drive each of the valve drivers 54 to 59,
The movement of the work machine is controlled by switching the corresponding operation valves 60, 61, 62.

In the case of this embodiment, in addition to the same effects as the previous embodiment, since the electronic control valve driven by the valve driver is used as the boom, arm, and bucket operation valve, it is possible to switch between these operation valves. The configuration for supplying the pilot pressure is not required, and the configuration of the hydraulic circuit becomes simpler.

〔The invention's effect〕

According to the present invention, the portion shallower than the designated excavation surface is freely excavated, and the movement of the work implement is restricted so that the portion deeper than the excavation surface cannot be excavated. By continuing the excavation without paying attention to the position of the cutting edge, the excavation surface can be excavated, the burden on the driver is reduced, work efficiency and excavation accuracy are improved, and the control system of the conventional excavating machine is slightly modified. The whole device is simple and reliable.

[Brief description of drawings]

Fig. 1 is a block diagram showing an embodiment of the present invention, Fig. 2 is a hydraulic circuit diagram corresponding to Fig. 1, Fig. 3 is an external view of a hydraulic excavator, and Fig. 4 is lengths and angles of various parts of a working machine. 5 is a diagram used to define changes in u with respect to α, β and γ, and FIG. 5 (A) is a diagram used to define α, β and γ.
When u increases with the increase of,
When u decreases with an increase in β and γ, FIG. 5 (C) is a diagram illustrating a case where u is constant with respect to an increase in α, β and γ, and FIG. 6 shows another embodiment of the present invention. Fig. 7 is a block diagram showing an example, Fig. 7 is a hydraulic circuit diagram corresponding to Fig. 6, Fig. 8 is a flowchart used to explain the operation of the controller, and Fig. 9 is a case where the bucket blade tip reaches the excavation surface. It is a figure used for explaining. 3 is a boom, 4 is an arm, 5 is a bucket, 6,7,8 are cylinders, 22,23,24 are angle detectors, 25 is a working machine blade edge position calculating means, 26 is excavation depth / excavation angle setting means, 27 is a comparison calculation means, and 28 is a work machine direction determination calculation means.

Claims (1)

[Claims] 1. A boom 3 whose one end is rotatably supported by a vehicle body, an arm 4 which is rotatably supported by the other end of the boom 3, a bucket 5 which is rotatably supported by the other end of the arm 4, and these In the control device of the excavating machine equipped with the cylinders 6, 7, and 8, which are the above-mentioned rotation supporting points of the boom 3, the arm 4, and the bucket 5.
Based on the signals from the angle detectors 22, 23, 24, which are provided in O, A, B respectively, and which output signals according to these rotation angles, and the signals from the above angle detectors 22, 23, 24, Working machine blade edge position calculating means 25 for calculating a position and outputting a corresponding position signal, and digging depth / digging angle setting means 26 for setting the digging depth and digging angle for defining the specified digging surface and the working machine blade edge position Based on the signal from the calculating means 25 and the excavation depth and excavation angle set by the excavation depth / excavation angle setting means 26, the positional relationship of the bucket blade tip point with respect to the designated excavation surface is comparatively calculated, and the bucket blade tip point is Based on the command signal from the comparison calculation means 27 and the comparison calculation means 27 that outputs a command signal according to the case of being located in a shallower portion than the specified excavation surface and the case other than that, the excavation specified by the bucket blade point is performed. When located in a part shallower than the surface Is not limited to the movement of the bucket blade point, otherwise the working machine direction determination calculation means 28 for outputting a signal to stop the movement of the bucket blade point in the direction of deeper An excavation control device for an excavating machine, characterized in that a control valve connected to each of the cylinders 6, 7, and 8 is operated by a signal from the determination calculation means 28 to activate or deactivate each cylinder. .