JPH1113703A - Method and device for suppressing vibration of hydraulic working machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a manufacturing cost of a device and besides to reliably suppress the generation of vibration during the stop of an actuator. SOLUTION: A bypass line 10 having a variable throttle 11 is arranged between the lines 6 and 7 on both sides of the boom cylinder 5 of a hydraulic shovel. A pilot pressure Pp by operation of a remote control valve 12 is detected by a pressure sensor 15. By means of the pilot pressure Pp, a pilot pressure fluctuation speed corresponding to an operation speed is computed by the pressure fluctuation speed computing part 17 of a controller 16. Based on the pressure fluctuation speed, an opening command value is determined by an opening command value computing part 18, and by outputting an opening command signal from an opening command part 19 to the variable throttle 11, the pressures of the lines 6 and 7 on both sides of the cylinder are rapidly balanced with each other during a rapid stop or rapid starting to suppress the generation of vibration.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration control method and a vibration control method for a hydraulic working machine such as a hydraulic shovel or a hydraulic crane, which suppresses the generation of vibration when a hydraulic actuator stops and starts.

[0002]

2. Description of the Related Art When a movable part having a large mass and a large inertia, such as a boom of a hydraulic shovel, is suddenly stopped or suddenly activated, a large pressure fluctuation occurs in a hydraulic actuator for driving the movable part.

[0003] In the case of a boom cylinder for raising and lowering the boom, for example, when the operation of tilting the boom (reducing the boom cylinder) is suddenly stopped, the head side pressure of the boom cylinder suddenly increases due to the inertia of the boom. To rise.

[0004] Then, the reaction force increases the pressure on the rod side of the cylinder, and the reaction force is further applied to the head side.

The repetition causes the piston rod to vibrate, and this vibration is transmitted to the machine main body, and the main body vibrates.

Since this vibration continues until the pressures on both sides of the cylinder are balanced, the operability deteriorates, and the workability also deteriorates, such that the next operation cannot be performed until the vibration stops.

Therefore, the following two methods have been proposed as methods for suppressing such vibration during sudden stop and sudden start of the actuator. The case of the boom cylinder will be described.

(A) As shown in Japanese Patent Application Laid-Open No. 6-185501, an accumulator is connected to a pipe connecting the boom cylinder and the control valve, and when the cylinder pressure increases, the accumulator is moved from the cylinder side to the accumulator side. If the cylinder pressure becomes lower, the pressure oil is released from the accumulator side to the cylinder side to reduce the fluctuation of the pressure.

In addition, a variable throttle is provided in the accumulator circuit, and the opening of the variable throttle is controlled in accordance with the fluctuation of the cylinder pressure detected by the pressure sensor so that the opening increases as the fluctuation component increases.

(B) As shown in Japanese Patent Application Laid-Open No. 6-17448, both side lines of the cylinder circuit are connected by a bypass line, an electromagnetic on-off valve is provided in the bypass line, and the operation lever is neutral. When the cylinder pressure becomes equal to or higher than a predetermined value, the solenoid on-off valve is opened to connect the two side pipes.

[0011] Thus, the pressure in the both-side pipes is quickly balanced, and the vibration of the boom cylinder due to the pressure difference between the two-side pipes is suppressed.

[0012]

However, the former accumulator system requires an expensive accumulator, and the latter bypass system requires a sensor for detecting operation of the operating lever and a sensor for detecting cylinder pressure. Therefore, the equipment cost increases.

In view of the above, the present invention provides a method and a device for suppressing vibration of a hydraulic working machine, which can reduce the cost of the device and can surely suppress the vibration when the actuator is stopped.

[0014]

According to a first aspect of the present invention, there is provided a hydraulic actuator, a control valve for controlling the supply and discharge of pressure oil to and from the hydraulic actuator, and an operating means for operating the control valve. In the hydraulic working machine provided with the above, a bypass pipe having a variable opening degree is provided between both side pipes connecting the hydraulic actuator and the control valve, and when the hydraulic actuator is operated, the bypass pipe is opened according to the operation speed of the operating means. The degree is controlled to increase on the high speed side.

The invention of claim 2 (vibration suppressing device) is characterized in that (i)
A hydraulic actuator, (ii) a control valve for controlling the supply and discharge of pressure oil to and from the hydraulic actuator, (iii) operating means for operating the control valve, and (iv) both-side pipes connecting the hydraulic actuator and the control valve. A bypass line provided between the
(v) a variable throttle provided in the bypass line;
The operating speed of the operating means is detected, and the opening of the variable throttle is controlled to increase on the high speed side in accordance with the operating speed.

According to a third aspect of the present invention, in the configuration of the second aspect, a hydraulic pilot switching valve is used as the control valve, and a remote control valve that supplies pilot pressure to the control valve through a pilot line is used as the operating means. Degree control means, pilot pressure detection means for detecting the pilot pressure, pressure fluctuation speed calculation means for calculating the detected pilot pressure fluctuation speed as an operation speed, and pressure fluctuation calculated by the pressure fluctuation speed calculation means. An opening command value for the variable throttle is calculated in accordance with the speed, and the opening command means is output as a command signal.

According to a fourth aspect of the present invention, in the configuration of the second or third aspect, the opening degree control means obtains (a) an operation acceleration of the operation means, and (b) performs a primary operation when the operation acceleration is equal to or less than a predetermined value. A command signal is output to the variable aperture with a delay.

According to the above method and apparatus, when the operating speed of the operating means is high, the opening degree of the variable throttle of the bypass pipe becomes large and the amount of pressure oil flowing in and out between the two pipes becomes large, so that the emergency stop is performed. Alternatively, even when a sudden start operation is performed, the pressure in the pipes on both sides is quickly balanced, and the vibration is attenuated.

Further, when the operating means is operated gently, the variable aperture is controlled to a small opening, so that there is no adverse effect that the response during normal operation is deteriorated as in the case where the opening is always large.

In addition, no accumulator is required, and
As a sensor, only a minimum for detecting the operation speed (pilot pressure detecting means in claim 3) is required, so that the apparatus cost can be reduced.

According to the fourth aspect of the present invention, the operation acceleration of the operation means is obtained, and when the operation acceleration is equal to or less than a predetermined value, the throttle opening command signal is output with a first-order lag. Function can be obtained.

In the hydraulic circuit, the response of the hydraulic system usually has a delay, so even if the sudden operation is completed (even if the operation speed is reduced), the pressure in the pipeline on both sides of the actuator remains at the level during operation for a certain period of time. Will remain.

Therefore, if the throttle opening is controlled based only on the operation speed, the throttle opening is immediately switched to the small opening at the end of the abrupt operation. The effect stops working.

Therefore, when the operation acceleration becomes equal to or less than a certain value as described above, that is, when the operation becomes gentle, a first-order lag is provided so that the throttle opening becomes large during the response delay. Since the vibration is attenuated and the vibration damping action is maintained, the vibration in this transition period can be suppressed.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described with reference to the drawings.

In this embodiment, a boom cylinder circuit of a hydraulic shovel is taken as an example in accordance with the conventional description.

In FIG. 1, reference numeral 1 denotes a main body of a hydraulic shovel, to which a digging attachment having a boom 2, an arm 3, and a bucket 4 is attached.

A boom cylinder 5 is mounted between the boom 2 and the shovel body 1.
The boom 2 moves up and down by the expansion and contraction operation of.

The head-side pipe line 6 connected to the head-side oil chamber 5a of the boom cylinder 5 and the rod-side pipe line 7 connected to the rod-side oil chamber 5b are connected via a control valve 8 of a hydraulic pilot switching type. The control valve 8 is connected to the hydraulic pump 9 and the tank T, and controls the operation direction and speed of the boom cylinder 5.

The head-side and rod-side quantity conduits 6,
A bypass pipe 10 is provided between the pipes 7, and a variable throttle 11 of an electromagnetic proportional type is provided in the bypass pipe 10.

Reference numeral 12 denotes a remote control valve as an operating means operated by a lever 12a. When the remote control valve 12 is operated, a pilot line 13a or 1
Pilot pressure is supplied to the operated side of the pilot ports 8a and 8b on both sides of the control valve 8 through 3b, and the control valve 8 is switched to operate.

Reference numeral 14 denotes a hydraulic pressure source for the remote control valve 12.

Pressure sensors 15 and 15 are connected to the pilot lines 13a and 13b on both sides, respectively. A pilot pressure Pp corresponding to an operation amount of the remote control valve 12 is detected by the pressure sensors 15 and 15, and a pilot pressure signal is outputted from the controller. 16 is input.

A controller 16 calculates a pressure fluctuation speed of the pilot pressure Pp from the pilot pressure signal, and an opening command for calculating an opening command value for the variable throttle 11 from the obtained pilot pressure fluctuation speed. A value calculation unit 18 and an opening command unit 19 that outputs a control signal corresponding to the command value to the variable throttle 11 are provided.

Since the pilot pressure signals from the pressure sensors 15 and 15 and the speed signal from the pressure fluctuation speed calculation unit 17 include noise, the pressure fluctuation speed calculation unit 17 and the opening command value calculation unit Filters (for example, low-pass filters having a cut frequency of 10 Hz) 20 and 21 for removing this noise are provided on each inlet side of the device 18.

The operation of this apparatus including the operation of each section of the controller 16 will be described with reference to the flowchart of FIG.

An example of a case where the boom cylinder 5 is stopped after the boom cylinder 5 is contracted will be described.
Is stopped, the pressure Pp of the pilot line 13b on the side that has been operated is reduced, the control valve 8 returns to neutral, and the reduction operation of the boom cylinder 5 stops.

At this time, the pilot pressure Pp is detected by the pressure sensor 15 and read into the controller 16 (step S1).

In the controller 16, after noise in the pressure signal is removed by the filter 20, the fluctuation speed V of the pilot pressure Pp is calculated by the pressure fluctuation speed calculation unit 17.

[0040]

V = dPp / dt (step S2).

The calculated pilot pressure fluctuation speed V
Is input to the opening command value calculation unit 18 via the filter 21, where the opening command value G for the variable throttle 11 is calculated as follows.

First, an absolute value | V | of the pressure fluctuation speed V is obtained as in the following equation (2) and multiplied by a gain α to obtain a basic command value F (step S3).

[0043]

F = α · | V | Further, after differentiating the pressure fluctuation velocity V in step S4 to obtain an acceleration A = (dV / dt), the acceleration A is compared with a preset value A0. (Step S5) When A ≧ A0 (YES in Step S5), it is determined that the emergency operation is being performed, and the basic command value F is determined as it is as the opening command value G (Step S6). When A <A0 (Step S5) If NO in S5), it is determined that the operation is gradual and

[0044]

## EQU3 ## An opening command value G is a value obtained by giving the primary command value F a first-order lag of a time constant T, such as G = (1/1 + Ts) .F (step S7).

The opening command value G is used as the opening command
2 to the variable throttle 11 as an opening command signal (step S8), and the valve 6 is set to the opening corresponding to the command signal.

In this way, the opening of the variable throttle 11 is controlled in accordance with the fluctuation speed V of the pilot pressure Pp.
The amount of outflow and inflow of pressure oil between 7 is increased.

Therefore, at the time of the sudden stop operation, the pressures in the both-side conduits 6 and 7 are quickly balanced by the inflow and outflow action of the pressure oil, and the vibration is damped.

Further, when the remote control valve 12 is operated slowly, the variable throttle 11 is controlled to a small opening degree, so that the responsiveness at the time of the normal operation is poor as in the case where the valve 11 is always kept at a large opening degree. Does not occur.

Further, in this device, the fluctuation acceleration A of the pilot pressure Pp is obtained as described above, and when this acceleration A is smaller than the fixed value A0, the opening degree command signal is output with a first-order lag of a time constant T. Since the throttle opening control during the abrupt operation is maintained for a certain period of time after the abrupt operation, vibration due to a response delay of the hydraulic system to the operation can be suppressed.

In this case, the first-order lag control is performed even during the normal slow operation, but there is no need to control the throttle opening during the slow operation.

FIGS. 3 to 5 show the results of vibration suppression by this device.

Here, as shown in FIG. 3, the remote control valve 12 is operated relatively slowly from the boom stop state to operate the boom 2 shown in FIG. %) And then at time t1
This shows a case where the neutral position is suddenly returned to the neutral position between t2 and t2.

FIG. 4 shows the opening command value output to the variable throttle 11 in response to the operation of the remote control valve 12, and FIG. 5 shows the change of the cylinder meter-in pressure as a result of the opening control. As shown by a solid line in FIG. 5, the conventional technology (bypass line 1 with a variable throttle 11)
Compared with the case where 0 is not provided, the fluctuation of the meter-in pressure can be rapidly attenuated even during a sudden operation (the generation of vibration due to the pressure fluctuation can be suppressed).

In the above embodiment, the operation speed is calculated using the pilot pressure. However, the operation amount of the remote control valve 12 may be detected by a sensor, and the operation speed may be calculated from the operation amount. Alternatively, the operation speed of the remote control valve 12 may be directly detected by a speed sensor.

The present invention can be widely applied not only to the boom cylinder circuit of the hydraulic shovel illustrated in the above embodiment, but also to an actuator circuit for driving a movable part having a particularly high inertia.

[0056]

As described above, according to the present invention, the operation speed of the operating means is detected, and when the operating means is suddenly stopped or suddenly operated, the operating means is provided in the bypass pipe between the pipes on both sides of the actuator. Since the opening degree of the variable throttle is increased to increase the amount of pressure oil flowing in and out between the two conduits on both sides of the actuator, the pressure in both conduits can be quickly balanced to suppress vibration. .

Further, when the operating means is operated gently, the variable aperture is controlled to a small opening, so that there is no adverse effect that the responsiveness during normal operation is deteriorated as in the case where the opening is always large.

Moreover, no accumulator is required, and
As a sensor, only a minimum for detecting the operation speed (pilot pressure detecting means in claim 3) is required, so that the apparatus cost can be reduced.

According to the fourth aspect of the present invention, the operation acceleration of the operation means is obtained, and when the operation acceleration is equal to or less than a predetermined value, the throttle opening command signal is output with a first-order lag. It is also possible to suppress the occurrence of vibration immediately after the end of the abrupt operation due to the response of the hydraulic system.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a hydraulic circuit and a control system for suppressing vibration thereof according to an embodiment of the present invention in which a boom cylinder circuit of a hydraulic shovel is used as an application example.

FIG. 2 is a flowchart for explaining the operation of the apparatus according to the embodiment.

FIG. 3 is a diagram showing an operation state of a remote control valve in the same device.

FIG. 4 is a diagram showing how an opening command value for a variable throttle changes when a remote control valve is operated.

FIG. 5 is a diagram showing a change state of a meter-in pressure of a boom cylinder.

[Explanation of symbols]

5 Boom cylinder (hydraulic actuator) 6, 7 Pipes on both sides of boom cylinder 8 Control valve 10 Bypass pipe 11 Variable throttle 12 Remote control valve as operating means 15 Pressure sensor for pilot pressure detection constituting opening control means 16 Open Controller constituting the degree control means 17 Fluctuating speed calculating section of the controller (fluctuating speed calculating means) 18 Opening command value calculating section of the controller (opening command means) 19 Opening command section (opening command means)

Claims (4)

[Claims] 1. A hydraulic working machine comprising a hydraulic actuator, a control valve for controlling the supply and discharge of pressure oil to and from the hydraulic actuator, and an operating means for operating the control valve, wherein the hydraulic actuator is connected to the control valve. A bypass pipe having a variable opening degree is provided between the two side pipes, and when the hydraulic actuator is operated, the opening degree of the bypass pipe is controlled to be increased on the high speed side in accordance with the operation speed of the operating means. Vibration control method of hydraulic working machine. (I) a hydraulic actuator; (ii) a control valve for controlling the supply and discharge of pressure oil to and from the hydraulic actuator; (iii) operating means for operating the control valve; and (iv) the hydraulic actuator. (V) a variable throttle provided in the bypass line, and (vi) detecting the operation speed of the operating means, and A vibration suppression device for a hydraulic working machine, further comprising an opening control means for controlling the opening of the variable throttle to increase on the high speed side in accordance with the opening. 3. The vibration suppressing device for a hydraulic working machine according to claim 2, wherein a hydraulic pilot switching valve is used as a control valve, and a remote control valve that supplies pilot pressure to the control valve through a pilot line is used as an operating means. The opening degree control means is obtained by the pilot pressure detection means for detecting the pilot pressure, the pressure fluctuation speed calculation means for calculating the fluctuation speed of the detected pilot pressure as an operation speed, and the pressure fluctuation speed calculation means. A vibration suppression device for a hydraulic work machine, comprising: an opening command means for calculating an opening command value for the variable throttle according to a pressure fluctuation speed and outputting the command signal as a command signal. 4. The vibration control device for a hydraulic working machine according to claim 2, wherein the opening control means determines (a) an operation acceleration of the operation means, and (b) when the operation acceleration is equal to or less than a predetermined value. A vibration suppression device for a hydraulic working machine, wherein a command signal is output to the variable throttle with a first-order delay.