JPS5865823A - Controller for operation locus of oil-pressure shovel - Google Patents

Abstract

PURPOSE:To prevent excessive excavation at the stroke end of an arm cylinder by a method in which when the arm cylinder reaches its stroke end or adjacent area, a signal to operate the arm cylinder is made to zero and a boom cylinder is stopped. CONSTITUTION:When an operating lever 13 is actuated, an arm cylinder 8 is controlled through a pressure oil flow regulating mechanism 12b according to its operating amount g2, and the relative angle alpha2 between a boom 4 and an arm 5 is varied. The variation is detected by an angle meter 11 and the output is sent out to any of function generators 14a and 14b through a switcher 16 which is operated by the output of a comparator 21 judging signal g2 generated in the operating lever 13. The function generators 14a and 14b are selected when the cylinder 8 makes an extending or contracting operation and is provided with a stopping zone in which output g1/g2 is zeroed when relative angle alpha2 reaches max. and min. angles or their adjacent values.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a work trajectory control device for a hydraulic excavator, and particularly to a work trajectory control device suitable for horizontal excavation.

FIG. 1 is a side view showing a schematic configuration of a hydraulic cylinder.

In this figure, 1 is an upper revolving body of a hydraulic excavator, 2 is a lower traveling body, and 3 is a front mechanism.
A boom 4 is supported at point a, which is a part of the revolving structure 1, so that it can be raised and raised freely, an arm 5 is supported at point b at the tip of the boom 4, so that it can swing, and a point 0 at the tip of the arm 5 is supported. It is composed of a rotatably supported packet 6. 7 is a boom cylinder that raises and lowers the boom 4 centering on the point a, and changes the relative angle between the upper revolving structure 1 and the boom 4; 8 swings the arm 5 centering on the above point, and moves the boom 4 and the arm The arm cylinder 9 changes the relative angle with the arm cylinder 5, and the cylinder 9 rotates the packet 6 around the front j20 point via the links 10m and 10b.

In the figure, α indicates the relative angle between the boom 4 and the arm 5, -min is the relative angle when the relative angle α becomes the minimum, and α2rnILx is the relative angle when the relative angle α becomes the maximum. It shows the relative angle.

Using a hydraulic excavator like this to level the ground'AI
As can be seen from the mechanism of the illustrated hydraulic excavator, the operator must extend and retract the poom cylinder 7 and arm cylinder 8 relative to each other at an appropriate speed, and this operation is extremely complicated. , which required the skill of Gao Yui.

For this reason: Conventionally, devices have been provided that allow machine-side work to be performed along a horizontal trajectory with simple operation. FIG. 2 shows such a conventional device, in which reference numeral 11 is an angle meter that detects the relative angle α between the boom 4 and the arm 5. The relative angle α is in degrees Celsius in Figure 1, and the maximum angle αI
The angle changes from IIIIIIIN to the minimum angle α2m1n.

12m and 12b are hydraulic flow rate adjustment mechanisms such as variable discharge capacity pumps, 12a is an electrical signal that adjusts the flow rate to the boom cylinder 7 (that is, the operating speed of the boom cylinder 7), and 12b is an 'eL gas flow rate adjustment mechanism. This is a flow rate adjustment mechanism that adjusts the flow rate to the arm cylinder 8 (that is, the operating speed of the arm cylinder 8) according to the number.

Reference numeral 13 denotes an operating lever provided on the driver's seat of the hydraulic excavator, which can be raised and lowered by the operator back and forth or left and right from a neutral position. and this signal q
, to the flow rate adjustment mechanism 12b, thereby controlling the expansion and contraction of the arm cylinder 7.

When the operating lever 13 is in the neutral position, the signal q is 0.
Therefore, the arm cylinder 7 is in a stopped state. When the operating lever 13 is tilted from the neutral position to one side, the signal q2 becomes a "+" polarity signal, causing the arm cylinder 7 to extend at a speed corresponding to the signal size. When the operating lever 13 is tilted from the neutral position to the other side, the signal - becomes a signal with a polarity of "-", and the arm cylinder 7 is retracted at a speed corresponding to the magnitude of the signal Qz.

14 is a function generator. In Fig. 3, this function generator 1
A diagram showing the characteristics of No. 4 is shown. Relative angle α between boom 4 and arm 5 detected by angle meter 11.

is applied to this function generator 14 as a signal, the function generator 14 generates two signals, one for instructing the flow rate to the arm cylinder 8 and the other for instructing the flow rate to the boom cylinder 7, according to the characteristics shown in FIG. The ratio qt/qt is generated. qt /Qt has a value such that the 0 point, which is the rotation point of the packet 6, moves horizontally with respect to the relative angle α.

-15 is a multiplier, in which qt/qt, which is the output from the function generator 14, is multiplied by a signal for instructing the flow rate to the arm cylinder 8, and as a result, the multiplier 15 generates a signal q1. That will happen. The generated signal is applied to the flow rate adjustment mechanism 12m of the boom cylinder 7 to control the speed of the boom cylinder 7 according to the signal qlK.

Reference numeral 23 denotes an arm angular velocity generator, which produces a signal Qt obtained by differentiating the signal from the angle meter 11 and outputs it as an output signal. The output signal generated by the arm angular velocity generator 23 is applied to the multiplier 15. Note that, instead of using the arm angular velocity generator 23, the signal qz generated by the operating lever 13 may be used as input to the multiplier 15.

The conventional device shown in FIG. 2 operates as follows.
Assume that the arm 5 is in the highest position relative to the boom 4, that is, the relative angle α is the minimum angle αlm1n shown in FIGS. 1 and 3.

From this state, when the operator moves the operating lever 13 from the neutral position to the side that generates the "+" signal in order to excavate the ground horizontally -f', a corresponding signal is generated, and this signal Q
t, the arm cylinder 8 begins to extend at a corresponding speed, and the relative angle α between the boom 4 and the arm 5 increases. The change in this relative angle α2 is determined by the function generator 14
is applied as a signal to the relative angle center K, so that the -function generator 14 calculates the ratio q+/Q! to the relative angle center K according to its characteristics. Output. This output Q+/42 K'Δ is the signal q? generated by the operation of the control lever 13 or the signal east from the arm angular velocity generator 23 in the multiplier 15. Since the multiplier 15 outputs the output signal Qt −
is obtained, and the obtained signal Q+ is applied to the flow rate adjustment mechanism 12m of the boom cylinder 7. When the signal q, is applied to the flow rate adjustment mechanism 12 &, the poom cylinder 7 applies the signal q, I
'm, and from the point when the relative angle α exceeds a certain angle, it contracts, and the operation of the boom cylinder 7 and the arm cylinder 8 combine to cause the excavation to reach the ground. This will be done in parallel. This motion is caused by a relative angle α, α! shown in FIG. This continues until maxK is reached.

When the magnitude of the signal q is arbitrarily changed using the operating lever 13, the input signal to the multiplier 15 changes as well, so the signal q also changes in proportion to this pressure. Therefore, by simply operating the operating lever 13, the boom cylinder 7 and the arm cylinder 8 are maintained in an appropriate speed relationship, and the ground can be excavated horizontally, and the excavation speed can also be freely selected.

The relative angle α is the maximum angle α2rnax shown in FIG.
When pushing the button 6 horizontally forward, the operating lever 13 is
The same operation as above is performed by changing the "-" signal to the permanent side. In this case, the equilibrium of the signal q becomes "-", the arm cylinder 7 performs a retracting operation, and the poom 6 first retracts, and the relative angle α! When the angle becomes less than a certain angle, it will extend.

Such conventional devices have the following drawbacks. That is, the relative angle between the poom 4 and the arm 5 becomes maximum or minimum when the arm cylinder 8 reaches near either stroke end. At this time, if the operator still holds down the operating lever 13, the signal q will continue to be generated even though the movement of the arm 5 has stopped.Therefore, the function shown in FIG. 3 will continue to be generated. Relative angle α of generator 14! The angle is αl nla! Or, even at the time of α1m1n, the corresponding q+/Qt is generated, and the multiplier 15 multiplies q and instructs the signal q to the boom cylinder 7, and the boom 4 does not operate. will continue to do so. That is, the relative angle α2 is α1 m
When the relative angle reaches α,maxlc while moving from In to α2max, the boom cylinder 7 continues to retract even though the arm cylinder 8 has stopped.
The poom 4 will move in the direction of being lowered. As a result, even if horizontal excavation is carried out, the final excavation part will be excavated excessively (in other words, it will be too rough), and the intended purpose of horizontal excavation cannot be achieved. , relative angle change α, moves from -m & Of course, if the operator senses the end of the arm cylinder 80 stroke and returns the operating lever 13 to the neutral position, the signal q will be generated. However, it is extremely difficult for the operator to sense the stroke end of the arm cylinder 8, and even if the operator returns the operating lever 13 to the neutral position immediately after sensing the stroke end, the poom 4 There is a possibility that the above-mentioned defects may occur.

An object of the present invention is to provide a device that, when excavating the ground with a hydraulic sill, prevents the trajectory of excavation from being disturbed even at the end of the stroke of the arm cylinder, and allows excavation to follow a predetermined trajectory until the end. be.

To achieve this objective, the present invention provides a device for detecting the relative position of the boom and the arm in a hydraulic Schochelnofront mechanism, and determining the ratio between the boom cylinder velocity and the arm cylinder speed from the detection signal of this detection device. and a means for controlling the flow rate to the boom cylinder and the arm cylinder according to this speed ratio, and means for stopping the movement of the boom cylinder when the arm cylinder reaches a small stroke end (both near the stroke end). It is characterized by this.

FIG. 4 shows an embodiment of the control device of the present invention.

In this embodiment, the same parts as those of the conventional device are given the same reference numerals, and the description of those parts will be omitted.

In FIG. 4, 14&, 14b are function generators used in the control device of the present invention, which generate a ratio ql/Qt for horizontally moving the rotation center point C of the packet 6. Figure 5(,) shows the function generator 14m, Figure 5(b)
is a diagram showing the characteristics of the function generator 14b when the function generator 14b changes towards the end (that is, the arm cylinder 8 is extended), and the relative angle α is an angle cr slightly smaller than the maximum angle α2m1LX, which is the stroke end. ; From maX to α! At angles up to max, its output q+/
A stop zone is provided where Qt is 0. Further, as shown in FIG. 5(b)K, the function generator 14b generates relative angles α,
is α2 rnax to α! rnin (that is, the arm cylinder 8 performs a contracting motion), at an angle between tll min and α2mIn, where the relative angle α is slightly larger than the minimum angle α2mIn, which is the stroke end. , its output Q+/Q
A stop zone is provided where t is O.

16 is a switching device having two contacts A and B, and an angle meter 11
This is a device for selectively supplying a signal from the function generator 14a or 14b to the function generator 14a or 14b.

21 is a comparator which receives a signal q generated by the operating lever 13;

The polarity of r+j, r-j is determined, and if the polarity is "+", a signal "1" is generated, and if the polarity is "-", a signal "0" is generated. The output signal "1" of the comparator 21 causes the switching device 16 to connect the signal from the angle meter 11 to the function generator 14a, and the output signal "0" connects it to the function generator 14b.

Note that the other configurations are the same as those of the conventional device.

The operation of the control device of the present invention shown in FIG. 4 will be explained.

Assume that the arm 5 is now in the state where it is lifted up the most with respect to the boom 4, that is, the relative angle α is at the minimum angle α2 min. From this state, in order to excavate the ground horizontally (when the operator tilts the operating lever 13 from the neutral position to the side that generates the "+" signal, the operating lever 13 generates a corresponding signal q2, and the signal q , the flow rate adjustment mechanism 12b of the arm cylinder 8 is activated to extend the arm cylinder 8 at a speed according to the signal QtK, so the relative angle α! between the boom 4 and the arm 5 increases.The signal q is " Since the polarity is "+", a "+" signal is input to the comparator 21, and its output signal becomes "1".Therefore, the switching device 16 is switched to the function generator 14b side.

The signal at the relative angle α, is applied to the switched function generator 14a K, and the function generator 14m is applied at the relative angle α2
The ratio (h/qt) corresponding to is output. This output q1/
Since qt is multiplied by the signal qt in the multiplier 15, the multiplier 15 outputs the signal q. The flow adjustment mechanism 12a is actuated by the signal q1, and the boom cylinder 7 is actuated at a speed corresponding to the signal q1, and as a result, the excavation 1 is performed parallel to the ground.

When the relative angle α reaches c4maxK shown in FIG. 5(-), the output from the function generator 14a is Q+/Qt becomes 0, and the signal qI from the multiplier 15 also becomes 0. Therefore, the operation of the boom cylinder 7 is stopped, and the boom 4 also stops its downward movement. Furthermore, the arm cylinder 8 is extended and the relative angle α becomes larger.

wax (at this time, Qt/Qt = -β), the arm cylinder 8 reaches the stroke end and stops its operation.

Next, the relative angle α is α! max to α2 rnin
A case will be described in which the packet 6 is pushed horizontally forward. In this case, the operating lever 13 is tilted from the neutral position to the side that generates the "=" signal. Since the signal q from the operating lever 13 operates the arm cylinder 8 and retracts the arm 5, the relative angle α between the boom 4 and the arm 5 becomes smaller (signal q).
, has a "-" polarity, a "-" signal is input to the comparator 21, and its output signal becomes "0". Therefore, the switching device 16 is switched to the function generator 14b side.

The signal of the relative angle α, is applied to the switched function generator 14b, which causes the multiplier 15 to output a signal q, corresponding to the relative angle α.

The boom cylinder 7 is operated at a speed according to the signal q.

When the relative angle α reaches aQ min shown in FIG. 5(b), the function generator 14b is The output Q+/Qt from becomes O,
The signal Q+ from the multiplier 15 also becomes O. Therefore, the operation of the poom cylinder 7 is stopped, and the poom 4 also stops its downward movement. Furthermore, the arm cylinder 8 contracts and the relative angle α2 becomes smaller, ~m1n (at this time, Q+ /
qt −−β. ), the arm cylinder 8 reaches the stroke end and stops its operation.

Note that the intervals between the stop zones from c/2rnax to (4tnlK) and from t4min to αlm1n of the function generators 14a and 14b are set small in order not to disturb the work trajectory.

As described above, in the embodiment of the present invention, two function generators 14a and 14b are provided, and the comparator 21 determines the polarity r+J and r-J of the east signal from the operating lever 13, and the switching device 16 to selectively connect the signal of the relative angle between the poom 4 and the arm 5 to either of the function generators 14a and 14b, and the function generator 14a,
14b, the relative angle α is a2max or α
Since the stop band where the output becomes O is set slightly before reaching lm1n, horizontal excavation will not be disturbed even if the arm cylinder 8 reaches either of its stroke ends. In addition, the intervals between the stop strips are made extremely small,
It goes without saying that the output of the time generator 14a or 14b may be set to 0 when the relative angle α2 substantially reaches α, max, or α2m1n.

FIGS. 6(&) and (b) show other examples of the characteristics of the function generator used in the present invention.
The characteristics of the function generator 14b are shown in FIG. 6(,), and the characteristics of the function generator 14b are shown in FIG. 6(b).

Function generator 14(a) shown in FIG. 5(&),(b)
, 14(b) is such that a stop band is set such that the output is O from (12mlLX to -max or from a/, rn i fi to α1 rnin), but as shown in Fig. 6(a ) is the characteristic of the function generator 14 (B) that as the relative angle increases from αS max to az m &
/ The value of qt is set to gradually decrease,
Furthermore, the characteristic of the function generator 14(b) shown in FIG. 6(b) is that as the relative angle decreases from a'2 min to α2 min, its output q+
/ The value of Qt is set to gradually decrease.

When a function generator with the characteristics shown in Figures 5(,) and (b) is used, the relative angle change is a! 1 max, α'2
Since the pool 4 is abruptly stopped when the minimum value is reached, the impact given to the operator is quite large. However, the sixth
If a function generator with the characteristics shown in Figures (a) and (b) is used, the poom 4 will gradually slow down and come to a stop, and the impact on the operator will be greatly reduced. .

FIG. 7 shows another embodiment of the control device of the present invention.

The difference between the embodiment shown in FIG. 7 and the embodiment shown in FIG. 4 is that the embodiment shown in FIG. The only difference is that a switch 25 is interposed between the two and the other points are exactly the same.

As is clear from the figure, the switch 25 is connected to the flow rate adjustment mechanism 1.
2m to the multiplier 15 or the boom lever 24.

Similarly to the arm lever 13, the poom lever 24 generates a corresponding signal when operated.

Connecting switch 25 to multiplier 15 results in the same operation as the embodiment shown in FIG. on the other hand,
When switch 25 is connected to boom lever 24, the poom will only be controlled by boom lever 24.

The device according to the embodiment shown in FIG. 7 has the advantage that, especially when it is desired to use only one of the function generators 14a and 14b, the purpose can be achieved by simply switching the switch 25. It is something.

FIG. 8 shows still another embodiment of the control device of the present invention.

In this embodiment, the same parts as those in the embodiment shown in FIG. 4 are given the same reference numerals, and explanations of those parts will be omitted. Unlike the embodiments shown in FIGS. 14 and 7, the function generator 14 used in this embodiment is different from the function generator 14 used in the conventional device shown in FIG. The same function generator (function generator) is used.

21a and 21b are comparators, and the comparator 21m outputs "1" when the signal from the operating lever 13 is "+";
-", outputs "0". The comparator 21b outputs "o" when the signal from the operating lever 13 is "+";
-", outputs "1".

Reference numerals 17m and 17b are setting angle generators, and the setting angle generator 17m has a relative angle α between the poom 4 and the arm 5 that is slightly smaller than α2max (Fig. 5 (1).
), the angle corresponding to 4max) is set. The set angle generator 17b has a relative angle α of α2. mln
a slightly larger angle (see Figure 5(b))
mln). 22m,
22b is a comparator, and the comparator 22m compares it with the relative angle from the angle meter 11, and the relative angle α is the set angle generator 17.
When the angle is smaller than the set angle of &, "o" is output, and when the angle is greater than or equal to the set angle, "1" is output. The comparator 22b compares the signal of the relative angle α with the set angle signal of the set angle generator 17b, and when the relative angle α is larger than the set angle of the set angle generator 17b, rOJ is set, and when the relative angle α is less than the set angle, rOJ is set. If so, it outputs "1".

18a and 18b are AND circuits;
a outputs "1" only when the output of the comparator 21m and the output of the comparator 22a become "1" at the same time, and the AND circuit 18b outputs the output of the comparator 21b and the output of the comparator 22b. It outputs "1" only when both become "1" at the same time.

19 is an OR circuit, which outputs "1" if the output of one of the AND circuits 18m and 18b is "1". 2o is a zero signal generator, and its output is always rOJ
It is.

16m is a switching device having two contacts A and B, and selectively connects the function generator 14 and the zero signal generator 20 to the multiplier 15 based on the output of the OR circuit.

That is, when the output of the OR circuit 19 is "0", the function generator 14 is sent to the multiplier 15, and the output of the OR circuit 19 is "0".
1, the zero signal generator 20 is connected to the multiplier 15.

Next, the operation of this embodiment will be explained.

First, the relative angle α2 between the arm 5 and the boom 4 is a.

Let us consider the case where the flow rate is moved from min to (4 ma Arm cylinder 8 is signaled (1
! Stretch at a speed appropriate to Signal q is the comparator 21a
, 21b, the polarity of the signal q is "+", so the output of the comparator 21a is "1" and the output of the comparator 21b is "0".

The signal of the relative angle α from the angle meter 11 is sent to the comparator 22m,
22b, but the relative angle α at the time arm 5 begins to extend! is small, the output of the comparator 22m becomes "0", and the output of the comparator 22b shows that the relative angle α is from α1m1n to a slightly larger angle (Fig. 5(b)
) is "1" in a short range up to (an angle corresponding to α'2 min), and becomes "0" when the angle is equal to or larger than the slightly larger angle.

As a result, the input of the AND circuit 18m is rj t rl
", the input to the AND circuit 18b is initially "1", ".

”, and “0” when the angle exceeds the slightly larger angle.

becomes "0", and in both cases, the AND circuits 18m, 18
The output of b, ie, the input of the OR circuit 19, becomes rOJ.

Since the input of the OR circuit 19 is rOJ, its output also becomes "0", and the switching device 16m maintains the state in which the function generator 14 is connected to the multiplier 15.

Therefore, the output ell/Q! of the function generator 14! is multiplied by the signal qt in the multiplier 15, so that the signal q
.

This signal q is applied to the flow rate adjustment mechanism 121 of the boom cylinder 7, and the boom cylinder 7 is operated at a speed according to the signal q, thereby performing horizontal excavation.

As the arm cylinder 8 continues to extend, the relative angle α.

is a slightly smaller angle than α2 tnax (Fig. 5).
) When the angle corresponding to c4 max in ) K is reached,
The output of the comparator 22a, which had been "0", becomes "1" (the outputs of the other comparators 21a, 21b, and 22b do not change). Then, comparator 21m and comparator 22m
Since both outputs are "1", the AND circuit 18m
The output of is "1", and the output of the OR circuit 19 is also [1]
becomes. Therefore, the switching device 16m connects the function generator 14 and the multiplier 15 to the zero signal generator 20 and the multiplier 15.
Switch to connection with. From this switching v, multiplier 1
5 input is "0" 1, therefore its output is also "0", and the flow rate adjustment mechanism 12m stops the operation of the boom cylinder 7. At this time, if the operating lever 13 remains pushed down, the arm cylinder 8 continues to extend, reaches the stroke end ((E! max'), and stops.

Next, the relative angle α between the arm 5 and the boom 4 is α.

Consider the case of moving from max toward α2m1n. In this case, the operating lever 13 is tilted to the "-" side, and the signal q generated in response thereto is applied to the flow rate adjustment mechanism 12b to retract the arm cylinder 8 at a speed corresponding to the signal Qz. The signal Qt is the comparator 21 凰, 21b K
However, since the polarity of the signal q is "-", the output of the comparator 211L is "0", and the output arm 5 of the comparator 21b is
Since the relative angle αt is large at the time when . It becomes "1" in a short section up to the angle corresponding to the bow max in ), and becomes "0" when the angle becomes equal to or less than the slightly small angle.

As a result, the inputs of the AND circuit 18a are initially "0" and "1".
”, when the relative angle α is less than or equal to the slightly smaller angle, ro”, r6. ), the input of the AND circuit 18b becomes "1" and "O", and in either case, the input of the AND circuit 18b becomes "1" and "O".
The output of m, 18b, that is, the input of the OR circuit 19 is "0".
”. Since the input of the OR circuit 19 is "O",
Its output also becomes "0", and the switching device 16m maintains the state in which the function generator 14 is connected to the multiplier 15. Therefore, the output ton/Qt from function generator 14 is equal to
5, the signal q is multiplied by the signal K to generate a signal 91, and this signal q is applied to the flow rate adjustment mechanism 12a of the boom cylinder 7 to operate the boom cylinder 7 at a speed corresponding to the signal Q+.

As the arm cylinder 8 contracts, the relative angle α becomes α, m.
An angle slightly larger than in (α in Fig. 5 (-')
2m1n K), the angle is 0.
", the output of comparator 22b becomes "1" (outputs of other comparators 21m, 21b, and 22m remain unchanged). Then, the outputs of the comparator 21m and the comparator 221L become "1j", so the output of the AND circuit 18b becomes "1", and the output of the OR circuit 19 also becomes "1". Therefore, the switching device 161L connects the function generator 14 and the multiplier 15 to the zero signal generator 20 and the multiplier 15.
Switch to connection with. By this switching, multiplier 1
5 becomes "0", and the flow rate adjustment mechanism 12a stops the operation of the boom cylinder 7.

At this time, if the operating lever 13 remains tilted, the arm cylinder 8 will continue to contract, and the stroke end (α
2 mIn) and stop.

In this way, the relative angle α, is αIrnax or α, m1
Shortly before nK is reached, the function generator 14 is switched to the zero signal generator 2.
0, and the signal applied to the flow rate adjustment mechanism 12m is set to ``0''.
"Therefore, in the embodiment shown in FIG. 8, similarly to the embodiment shown in FIG. 4, when the arm cylinder 7 reaches the stroke end, the boom cylinder 8 is stopped,
Therefore, an undisturbed suppression trajectory can be obtained.

In the embodiment shown in FIG. 8 described above, the configuration of the portion surrounded by a chain line can be replaced by a control device 30 configured by a microcomputer. below,
This control device 30 will be explained based on FIGS. 9 and 10.

FIG. 9 is a system configuration diagram of a control device 30 composed of a microcomputer, and a portion 33 surrounded by a dotted line indicates the microcomputer. FIG. 10 shows a flowchart of the microcomputer 33. Control device 3 consisting of a microcomputer as shown by the dashed-dotted line in FIG.
0, an A/D converter that converts the relative angle signal α between the boom 4 and the arm 5 from the angle meter 11 into a digital signal, a signal from the operating lever 13, or a signal from the arm angular velocity generator. It is necessary to provide an A/D converter for converting Q into a digital signal and a D/A converter for converting the output signal Q+ from the multiplier 15 into an analog signal. In FIG. 9, each of the A/D converters is designated at 32, and the D/A converter is designated at 38. In FIG. 9, numeral 31 is a multiplexer that sequentially switches the relative angle signal α2 and the signal from the operating lever and inputs it to the next A/D converter 32. The A/D converter 32 converts the signal α and the signal q into digital signals as described above. The microcomputer computer 33 is composed of a central processing unit (hereinafter referred to as CPU) 34, read-only memories (hereinafter referred to as ROM) 35 and 36, and random access memory (hereinafter referred to as RAM) 37. Ru. ROM35 contains microcomputer 3.
3 control programs are stored, and the microcomputer 33 operates according to the order of these programs.

The ROM 36 stores a function table of the ratio q+/Qt of the signal Qt for the angle signal α and the operation signal (11) of the boom cylinder 7. signal α, and q
, is temporarily stored. CPU34 is ROM
It performs various processes in accordance with the order of programs stored in the controller 35 and outputs signals for operating the boom cylinder 7. The output signal from the microcomputer 33 is converted to the D/A converter 538 described above.
The signal is converted into a signal number and output from the control device 3o as a boom cylinder tough operation signal q1.

The operation of the micro combinator 33 will be explained according to the flowchart of FIG.

The relative angle signal α and the signal q from the operating lever 13 are read through the multiplexer 31 and the A/[) converter 32, and are stored in the RAM 37. (operation procedure a)
, b). Next, the KCPU 34 judges whether the signal q is "+" or "-" (operation procedure C), and if it is "+", that is, the arm 5 changes from α2 min to α1 tnax.
If the signal αt is moving towards αG maX
(Angle slightly smaller than 14 maX) or more (operation procedure d). If the signal α is smaller than 4 maX, that is, if the signal α!
Ql/q! corresponding to the signal α from the function table of 6! (operation procedure f). Also, the signal α is 4 m
M! In the above case, that is, when the signal α is in the stop zone, qt/bug is set to O (operation procedure g).

On the other hand, in operation procedure C, if the signal q is determined to be "-", that is, if the arm 5 is moving from αl maX to -min, the signal α is changed to α'tmin (
α.

(angle slightly larger than min) or more (
Operation procedure e), signal α! Gaa! If it is greater than 1 min, that is, if the signal α is not in the stop band, the ratio of qt/Qt corresponding to the signal α is read from the function table in the ROM 36 (operation procedure f). Also, the signal α is c4 r
When ain or less, that is, when the signal α is in the stop zone, t/q is set to O (operation procedure g). - Perform the operation of multiplying the signal q by the signal q to (b/' qt or O obtained in the above manner) to obtain Qs (operation procedure h). The obtained q is the output of the microsimulator 33. The data is sent to the D/A converter 38 (operation procedure I).

When the operation procedure i ends, the operation of the micro combinator 33 returns to the operation procedure a again, and the above operation is repeated.

The analog signal Q+ from the D/A converter 38 is applied to the boom cylinder flow rate adjustment mechanism 12m as an operation signal for the boom cylinder 7.

As described above, the operation of the MyKurocomputer 33 repeats the operation procedure a = 1, and this operation procedure a =
This means that the signal q is updated every time 1 is completed. The time required to perform operation procedure a j-1 is set to a time that does not affect control performance. Of course, the relative angle signal α from the angle meter 11 and the signal signal from the operating lever 13 are taken in in synchronization with the operating procedures a to 1. Also, the above a! 1
max and c4 min can be set arbitrarily within the operating procedure.

Note that in the above explanation, the function generator 14 includes a third
Although the description has been made assuming that a function generator having the characteristics shown in the figure is used, it is also possible to use a function generator having the characteristics shown in FIGS. That is, Fig. 6 (
, ), and set the setting angle of the setting angle generator 17a or the angle set in the mic beater to almaX instead of α9m1x, or as shown in FIG. 6(b). Using a characteristic function generator,
The setting angle of the setting angle generator 17b or the angle set in the microcomputer is α2 minζ instead of α;min.
do.

By performing K in this manner, the poom 4 is gradually stopped at one of the stroke ends. This makes it possible to reduce the impact on the operator.

In the embodiment shown in FIG. 8 and the embodiment in which the dashed-dot line part in FIG. , and a preset angle, and a circuit that determines whether the zero signal generator 20 or the function generator 14 should be connected to the multiplier 15 based on the combination of the outputs of both circuits is configured with logic circuits. Or, these logic circuits and setting angle generator 17m, 1
7b, zero signal generator 20, function generator 14, and switching device 1
16m and the multiplier 15 are replaced with a microcomputer device. Therefore, the turbulence reliability at the stroke end of the arm cylinder 7 is improved as in the embodiments shown in FIGS. 4 and 7, and the size is also reduced. It also makes a contribution.

In addition, in the explanation so far, we have talked about horizontal excavation, but it is also applicable not only to slope excavation and other types of excavation along various trajectories, or to cypress cutting (also to work when transferring excavated soil etc. to a transport vehicle). The control device of the present invention can be used by selecting the characteristics of the function generator according to the required trajectory.

Furthermore, in the explanation so far, the positional relationship between the poom 4 and the arm 5 is detected by the angle, but it can be detected not only by the angle but also by the stroke of the arm cylinder 8. , it is only necessary to detect the relative positions of the boom 4 and the arm 5.

As described above, the working trajectory control device for a hydraulic excavator of the present invention stops the boom cylinder by setting the signal O to operate the boom cylinder when the arm cylinder reaches the vicinity of its stroke end or reaches the stroke end. By setting the stroke end trap of the arm cylinder, it is possible to completely eliminate disturbances in the excavation trajectory caused by excessive excavation.

[Brief explanation of drawings]

Fig. 1 is a side view showing a schematic configuration of a hydraulic excavator, Fig. 2 is a block diagram of a conventional work trajectory control device for a hydraulic excavator, and Fig. 3 is a side view showing a schematic configuration of a hydraulic excavator. FIG. 4 is a block diagram of a work trajectory control device for a hydraulic excavator according to an embodiment of the present invention, and FIG. 5(a) and FIG. Figure 6 (a) and (b) are diagrams showing an example of the characteristics of the Seki 1 Keigen generator used in the (6)
FIG. 7 is a block diagram of a working trajectory control device for a hydraulic excavator according to another practical example of the present invention; FIG. 8 is a block diagram of a working trajectory 111i1 fJ"Jf=lit of a hydraulic excavator according to yet another embodiment of the present invention,
FIG. 9 is a system configuration diagram when the one-point rivet in the block diagram of FIG. It is a chart. 1...Upper rotating body, 2...Lower traveling body, 3...Front structure, 4...Boom, 5...Arm , 6...Packet, 7
...Boom cylinder, 8...Arm cylinder, 9...Packet cylinder, 11...
... Angle meter, 12a, 12b ... Current adjustment mechanism, 13 ... Operation lever, 14, 14a, 14
b...function generator, 15...multiplier,
16.16a...Switch, 17a. 17b... Setting angle generator, 18a, 18b.
...1i1 logic circuit, 19 ... - earth phase circuit, 20 ... zero signal generator, 21 a, 2
lb, 22a, 22b--Comparator, 23...Arm angular velocity generation wearer, 30...
...control device configured with a microcomputer,
31...Multiplexer, 32...A
/D & Exchange! , 33... microcomputer,
34...(,'PU, 35.36...
1-LOM, 37...RAM, 38...
・D/A converter 14, -5i Figure 2 Figure 3 Figure 4 Figure 5 (a) (b) Figure 6 (a) RB Figure 7 Figure 8

Claims (1)

[Scope of Claims] 1. A lower traveling body, an upper revolving body, a front mechanism consisting of a boom, an arm, and a packet, a boom cylinder that raises and lowers the boom, an arm cylinder that swings the arm, and the packet. a packet cylinder for rotating the cylinder; a device for detecting the relative position of the boom and the arm; a means for determining the ratio between the boom cylinder speed and the arm cylinder speed from the detection signal of the detection device; In the work trajectory control device for a hydraulic excavator, the work trajectory control device for a hydraulic excavator includes means for controlling flow rates to the boom cylinder and the arm cylinder, further comprising means for stopping the movement of the boom cylinder when the arm cylinder reaches at least near a stroke end. A work trajectory control device for a hydraulic excavator, characterized by the following. 2. In claim 1, the stopping means:
A work trajectory control device for a hydraulic cylinder, characterized in that the boom cylinder speed is gradually reduced and stopped from when the arm cylinder reaches near the stroke end.