JPS63312433A - Stop controller for slewing body - Google Patents

Abstract

PURPOSE:To raise the efficiency of operation by a method in which the connection of the main pipes by valves is controlled on the basis of a time point when the lever is in neutral position and the speed of a slewing body reaches a given value. CONSTITUTION:When a lever 8 is set to neutral position, the pressure of the main pipeline A is reduced, the pressure of the main pipeline B is raised and the speed N of a slewing motor 3 is lowered to within a fine speed range. In a controller 13, counting of a set time taken for the motor 3 to become speed zero(0) from a given speed close to zero is started. When the set time is lapsed, the controller 13 begins to operate a counter to set a time period which is led to a switch valve 11. The valve 11 is switched until counted up to connect the main pipelines A and B.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a stop control device for a rotating body used for stopping the rotation of a rotating body with large inertia.

[Conventional technology]

Many working machines are equipped with rotating bodies that have large inertia. Typical examples include hydraulic excavators and crane revolving bodies. Such rotating structures are often driven by hydraulic motors. Hereinafter, a hydraulic circuit of a hydraulic motor (hereinafter referred to as a swing motor) that drives an upper rotating structure of a hydraulic excavator will be described.

FIG. 4 is a system diagram of a hydraulic circuit of a conventional swing motor.

In the figure, 1 is a hydraulic pump, 2 is an engine that drives the hydraulic pump 1, 3 is a swing motor driven by the hydraulic pump 1, and 4
shows an upper revolving body of a hydraulic excavator connected to a swing motor 3. 5 is a directional switching valve that controls the drive of the swing motor 3, and this directional switching valve 5 and the swing motor 3 are connected to the main pipe A.
, B. 6 is a pressure setting device connected between main pipes A and B, and is composed of two relief valves and two check valves. 7 indicates a hydraulic oil tank.

Reference numeral 8 denotes a swing operation lever (hereinafter simply referred to as lever) for controlling the drive of the swing motor 3. A lever position detector 9 detects the operating position of the lever 8, and outputs an electric signal proportional to the operating amount of the lever 8. Reference numeral 10 denotes a control device which inputs the signal from the lever position detector 9 and operates the directional control valve 5 in accordance with the signal.

When the lever 8 is operated in the direction of the arrow M in order to rotate the swing motor 3 in the direction of the arrow M, the control bag ? ! The IO controls the directional valve 5 accordingly. As a result, the pressure oil from the hydraulic pump 1 is supplied to the main pipe HA via the direction switching valve 5, causing the hydraulic motor 3 to rotate in the direction of arrow M, and the rotating structure 4 to rotate.

Next, in order to stop the rotating upper structure 4, the lever 8
When the control device 10 returns the directional control valve 5 to the neutral position, the control device 10 sets the directional control valve 5 to the neutral position. For this reason, the IA in charge.

B is blocked. On the other hand, since the upper rotating body 4 continues to rotate due to its inertia, the swing motor 3 functions as a hydraulic pump, and the oil in the main pipe A is sucked into the swing motor 3 and discharged into the main pipe B. As a result, the oil pressure in the main pipe B becomes high, and this becomes a control force to rapidly decelerate and stop the swing motor 3. In addition, when the oil pressure in main pipe B reaches the pressure set in the pressure setting device, a part of the oil is discharged to the hydraulic oil tank 7 via the relief valve, and the upper limit pressure in main pipe B is adjusted to the pressure set above. Protect the various elements of the hydraulic circuit by regulating the pressure.

[Problem that the invention seeks to solve]

However, in the conventional hydraulic circuit described above, it is difficult to stop the swing motor 3 smoothly.

The reason for this will be explained with reference to the waveform diagrams shown in FIGS. 5(a) to 5(C). As mentioned above, when the lever 8 is placed in the neutral position at time 1 while the swing motor 3 is rotating, as shown in FIG. First, the rotation continues until time t2 as shown in FIG. 5(b). On the other hand, when the lever 8 returns to the neutral position and the swing motor 3 continues to rotate, the pressure PA in the main pipe A rapidly decreases, and conversely, the pressure P in the main pipe B decreases, as shown in Fig. 5(C). rise rapidly. A braking force acts due to the increase in pressure pH, and the swing motor 3 stops at time t2. At this time, due to its compressibility, the hydraulic oil is compressed and forced into the main pipe B and has a high pressure, and this high-pressure hydraulic oil causes the swing motor 3 to move as shown in FIG. 5(b). It is rotated in the direction opposite to arrow M.

Due to this reverse rotation of the swing motor 3, the pressure P3 in the main pipe B decreases as shown in FIG. 5(C), but the hydraulic oil that was in the main pipe B is forced into the main pipe A, and the pressure
rises. When the reverse rotation of the swing motor 3 stops at time t3, the swing motor 3 rotates in the direction of arrow M due to the compressibility of the hydraulic oil forced into the main pipe, and the pressure PA in the main pipe A decreases. The pressure P in the main pipe B increases.

After such a phenomenon is repeated, the swing motor 3 stops only at time t4.

In this manner, the swing motor 3 repeats rotation in the direction of arrow M and rotation in the opposite direction several times (swinging) when stopped. This swaying causes great discomfort and fatigue to the operator operating the hydraulic excavator, and also makes it difficult to position the rotating upper structure 4 because it cannot be stopped at an accurate position. This causes fatigue and reduces operating efficiency.

SUMMARY OF THE INVENTION The present invention solves the problems of the prior art described above and provides a stop control device for a rotating body that can smoothly stop a swing motor without causing any oscillation.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a swing speed detection method for detecting the swing speed of the swing structure in a swing structure driven by a swing motor controlled by a swing operation lever. means and
A lever position detection means for detecting the neutral position of the swing operation lever, a valve for communicating and cutting off the boats on both sides of the swing motor, and a lever position detection means that detects the neutral position of the swing operation lever, the swing operation lever is in the neutral position, and the swing speed of the swing structure is at a predetermined value. The present invention is characterized in that it is provided with a control section that controls communication and shutoff operations of the valve based on when .

[For production]

The control section determines the swing speed and lever position based on signals input from the swing speed detection means and the lever position detection means. When the lever position is at the neutral position and the turning speed reaches a predetermined speed,
A control operation for opening and closing the valve is started, and the valve is first opened to release the pressure oil in the high-pressure side main line of the swing motor to the low-pressure side via the valve, and then the valve is shut off.

〔Example〕

Hereinafter, the present invention will be explained based on illustrated embodiments.

FIG. 1 is a system diagram of a hydraulic circuit for a swing motor using a stop control device for a swing body according to an embodiment of the present invention. In the figure, parts that are the same as those shown in FIG. 4 are given the same reference numerals, and description thereof will be omitted. Reference numeral 11 denotes a switching valve connected between the main pipes A and 3. This switching valve 11 is an electromagnetic switching valve, and is normally in the upper blocking position in the figure, and when energized becomes the lower communicating position in the figure. The communication between the main pipes A and 3 at this communication position is in a constricted state as shown in the figure. A speed detector 12 detects the rotation speed of the swing motor 3 (therefore, the swing speed of the upper swing structure 4), and outputs a signal proportional to the rotation speed of the swing motor 3. Reference numeral 13 denotes a control section that inputs signals from the lever 8 and the speed detector 12 and executes predetermined control.

Next, the operation of this embodiment will be explained with reference to the waveform diagrams shown in FIGS. 2(a) to 2(4) and the flowchart shown in FIG. In this embodiment, when the swing motor 3 stops, the switching valve 11 is switched to connect the main pipes A and B, and the pressures in these two-way pipes A and B are equalized to operate the swing motor 3 without causing any oscillation. It's trying to stop it. In such a means, the speed ot- of the swing motor 3 must be detected by the speed detector 12, but since it is extremely difficult to detect a speed of 0, in this embodiment, the second speed is detected instead of the speed of 0. As shown in figure (b), the speed O
A certain speed N0 close to is determined, and furthermore, the rotation motor 3
is the speed N. The time T that is assumed to be required for the speed to reach the speed O is determined. Also, the time Δ for communicating the switching valve 11
T is also determined in consideration of various conditions. These values N,
, T, and ΔT are set in the control section 13.

Now, assuming that the detection signal of the speed detector is N and the detection signal of the lever position detector 9 is X, the control section 13 always outputs the signals N,
(Step S in the flowchart shown in Figure 3)
+). Rotate the swing motor 3 in the direction of arrow M (lever 8
When is operated in the direction of the arrow, the control section 13 switches the directional switching valve 5 according to the input signal X corresponding to this. As a result, the turning motor 3 starts turning in the direction of arrow M.

The control unit 13 performs an operation of comparing the input signal N and the set speed N0, but since this processing is performed digitally, the speed N. There is a possibility that only the values before and after are read, and the value of the speed N0 is not read. In order to prevent this, in this embodiment, as shown in FIG. 2(b), a very small speed range ΔN before and after the speed N0 is determined (however, ΔN>N). It is determined whether or not N is within the minute speed range ΔN with respect to speed N0. That is, the control unit 13 reads the speed signal N and calculates (N-N,
), and its absolute value is less than or equal to ΔN (IN-NO
+4ΔN) (step 33).

Immediately after the turning motor 3 starts turning, its speed N is as shown in Fig. 2 (b
), it enters the minute speed range ΔN.

At this time, in step S2, the control unit I3 (IN-N
o! ≦ΔN), and then it is determined whether (x=0), that is, whether the lever 8 is in the neutral position (step S).

In this case, since the lever 8 is not in the neutral position, the control unit 13
sets the above-mentioned time T and ΔT in the counter (step 3a)
). Next (step S, in which the control unit 13 sets the switching valve 11 to the cutoff position), and then returns to step S1. When the speed N deviates from the minute speed range ΔN and increases, the processing in the control section 13 repeats steps S+, Sz, and S.

Now, at time t0, the lever 8 is operated toward the neutral position as shown in FIG. 2(a), and at time 1. Suppose that it is placed in a neutral position. In this case, as shown in FIG. 2(c), the pressure PA in the main pipe A decreases, and the pressure PB in the main pipe B rapidly increases, causing a braking force to act and the speed of the swing motor 3 to decrease. It decreases as shown in FIG. 2(b).

In this way, when the speed decreases and eventually enters the minute speed range ΔN around time t2, the control unit 13 performs step S2.
Then, in step S4, it is determined whether the signal X is 0, that is, whether the lever 8 is in the neutral position. in this case,
Since the lever 8 is already in the neutral position, the control unit 13 starts counting the counter set to the time T in step S4. Then, it is determined whether or not this counter has counted up (Step S6), and Step S+ is continued until the counter counts up.
, Sz, Sz, Sb, and Ss are repeated.

When the time T has elapsed, the control unit 13 starts counting the counter to which the time ΔT has been set, and checks whether or not this counter has counted up (step 57). Since the count-up has not yet been reached at the start of counting, the control section 13 switches the switching valve 11 upward in FIG. 1 to establish communication between the main pipes A and B (step SS).

The above steps Sb, S? , Ss in Fig. 2(b) to (d)
), as shown in FIG. 2(b), the time t when the speed N-1i<m of the swing motor 3 enters the small speed range ΔN
Counting of time T starts from 2, and during this time, the main pipe B
Since the pressure P is high, the turning morph 3 continues to decelerate. In this state, when the time T counts up at time L3, the speed of the swing motor 3 becomes almost O as shown in FIG. 2(b), and it is in a nearly stopped state. Then, as the time T counts up, the time ΔT starts counting, and the switching valve 11 is switched as shown in FIG. 2(d), and the main pipes A and B are brought into communication. Therefore, as shown in FIG. 2(c), the pressure PB in the main pipe B rapidly decreases, the pressure PA in the main pipe A increases, and both positive forces PA
, PB have some equal pressure PC. , 2, the swing motor 3, which is in a nearly stopped state, stops at time t4.

On the other hand, the control unit 13 performs the steps Sl, S2, Sz
, S6+S7. By re-manipulating the process of Ss, we obtain the result shown in Figure 2 (
b) As shown in (c), at time t, time Δ
When it is determined that T has elapsed, the process moves to step S5, and the switching valve 11 is shut off as shown in FIG. 2(d).

In this way, in this embodiment, a setting range close to O is provided for the speed of the swing motor, and when the swing motor stops and its speed falls within the setting range, the speed from this setting range until the speed reaches O is set. After a predetermined amount of time has elapsed, the switching valve is switched for a certain period of time to communicate the two main pipes, so when the swing motor stops, the hydraulic fluid that was forced into one main pipe passes through the switching valve and flows into the other. It is possible to equalize the pressure in both main pipes, thereby preventing swinging and smoothly stopping the swing motor.

Since such a smooth stop can be performed, it becomes easy to determine the stopping position, which not only improves work efficiency, but also eliminates operator discomfort and reduces fatigue. . or,
Except when the switching valve is in communication, the switching valve is always shut off, so when the swing stops, the lever is returned to the neutral position, and then the lever is operated again when it is necessary to swing further. In this case, the swing motor can be immediately driven in response to this operation.

In the above embodiments, the upper revolving structure of a hydraulic excavator was used as an example of the revolving structure, but the present invention can be applied to any revolving structure driven by a hydraulic motor. Furthermore, although an example has been described in which counters are used to measure two set times, it is clear that the total of the two set times can be set in one counter.

Also, (IN-NOl≦ΔN) was used to judge the speed, but (
It may be determined that N<N(+).

〔Effect of the invention〕

As described below, in the present invention, communication between the main pipes is controlled by the valve based on the point in time when the lever is in the neutral position and the turning speed of the rotating body reaches a predetermined value. , the rotating body can be stopped smoothly without rolling back, thereby making it possible to stop the rotating body at an accurate position, improving work efficiency, eliminating operator discomfort, and It can reduce fatigue.

[Brief explanation of drawings]

FIG. 1 is a system diagram of a hydraulic circuit of a swing motor using a stop control device for a swing body according to an embodiment of the present invention; FIG. 2(a);
(bL (c) and (d) are waveform diagrams explaining the operation of the stop control device shown in Fig. 1, Fig. 3 is a flowchart, and Fig. 4
The figure is a system diagram of the hydraulic circuit of a conventional swing motor.
), (b), and (c) are waveform diagrams illustrating the operation of each part shown in FIG. 4. ■・・・・・・・・・Hydraulic pump, 3・・・・・・・・・
・Swivel motor, 4... Upper rotating body, 8.
......Lever, 9...Lever position detector, 11...Switching valve, 12...
...... Speed detector, 13... Control section. 1st ward 3: Turning morph 8 = L bar 9: shiha'°-i tate (unjyoya deja Il: katana Jouben 12: Matsu Moroki 13: New year's good fortune p Figure 2 Figure 3

Claims (2)

[Claims] (1) In a rotating body driven by a swing motor controlled by a swing operation lever, a swing speed detection means for detecting the swing speed of the swing structure, and a lever position detection means for detecting the neutral position of the swing operation lever. , a valve for communicating and blocking ports on both sides of the swing motor, and a valve for communicating and blocking the valves based on when the swing operation lever is in a neutral position and the swing speed of the swing body reaches a predetermined value. What is claimed is: 1. A stop control device for a revolving body, comprising: a control section for controlling the swing body; (2) In claim (1), the control section controls the valve after a certain set time has elapsed after the swing operation lever is in the neutral position and the swing speed of the swing body reaches a predetermined value. 1. A stop control device for a swinging body, comprising: a communication means for communicating with the valve; and a cutoff means for blocking the valve after a certain set time has elapsed since the valve has communicated.