JPH06159314A - Driving control device of inertia body - Google Patents

Abstract

PURPOSE:To control an actuator pressure properly by finding out a difference between a set flow and a real flow corresponding to operating amounts in both directions of a control valve on the basis of an operation detection signal and a flow detection signal so as to change a relief valve setting pressure according to the difference thereof, in the driving control device of the top part turning body of a hydraulic shovel and the like. CONSTITUTION:A control signal in relation to the operation signal of an operating body 19 is transferred from a controller 20 to the operation part 14a of a turning control valve 14. Stroke operation of a direction and an amount corresponding to the operating direction of the operating body 19, and an operation amount, is carried out by the control valve 14 respectively. A set flow which is proportional to the operation amount is transferred to a motor circuit 13. The flow is detected by a flow meter 21, and the difference between a set flow and the real flow is found out by the controller 10 so as to change set pressure of the relief valve 15. For example, since a set flow is larger at the time of starting, set pressure of the relief valve 15 is increased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive control device for controlling starting and stopping operations of an inertial body having a large inertia such as an upper swing body of a hydraulic excavator.

[0002]

2. Description of the Related Art A conventional technique will be described by taking an upper swing body of a hydraulic excavator (hereinafter simply referred to as a swing body) as an example.

In FIG. 7, reference numeral 1 denotes a hydraulic motor (hereinafter, simply referred to as a motor) for driving a revolving structure to rotate, and 2 denotes a pump for supplying pressure oil to the motor 1, which constitutes the pump 2 and a motor circuit 3. A swing control valve (hydraulic pilot type switching valve) 4 is provided between the both side conduits 3a and 3b, and the swing control valve 4 is operated by a remote control valve (not shown) to turn the neutral position a, the left swing position b, and the right turn. The rotation direction and speed of the motor 1 are controlled by switching between the rotation position c and the rotation position c.

A relief circuit 6 having a pair of relief valves 5 and 5 is connected to the motor circuit 3 so that the motor pressure when the motor 1 is started and stopped is reduced by the relief valves 5 and 5.
It is set by 5.

Reference numerals 7 and 7 denote the motor 1 during inertial rotation of the motor 1.
A check valve 8 is a main relief valve for supplying oil to the inlet side of the.

[0006]

However, according to the above configuration, since the set pressures of the relief valves 5 and 5 are constant and constant, for example, the motor pressure (starting torque) is insufficient at the time of start-up and the start-up does not start smoothly. However, the motor outlet pressure (brake torque) becomes excessive at the time of stop, and the swinging back occurs.

Therefore, the present invention provides a drive control device for an inertial body capable of appropriately controlling the actuator pressure at the time of starting and stopping.

[0008]

According to a first aspect of the present invention, there is provided a hydraulic actuator for swinging and driving an inertial body, a relief circuit connected to a drive circuit of the hydraulic actuator, and a variable set pressure provided in the relief circuit. Type relief valve, a control valve provided between the drive circuit and a pump as a pressure oil supply source, operation detection means for detecting the operation direction and operation amount of the control valve, and the drive circuit And a controller for controlling the set pressure of the relief valve. The controller operates the control valve in both directions based on the detection signals of the operation detecting means and the flow detecting means. It is configured to obtain the difference between the set flow rate corresponding to the amount and the actual flow rate, and to output a signal that changes the set pressure of the relief valve according to this flow rate difference. That.

According to a second aspect of the present invention, in the configuration of the first aspect, a speed detecting means for detecting an actual operating speed of the hydraulic actuator is provided in place of the flow rate detecting means, and the controller operates the control valve in both directions. The difference between the set operating speed of the actuator corresponding to the amount and the actual operating speed detected by the speed detecting means is obtained, and a signal for changing the set pressure of the relief valve is output according to the speed difference. It was done.

[0010]

According to the structure of claim 1, the set flow rate corresponding to the operation amount of the control valve is compared with the actual flow rate of the drive circuit, and the relief pressure is set to a value corresponding to this flow rate difference (relief oil amount). Therefore, the actuator pressure is set to be high if the flow rate difference is large and set low if the flow rate difference is small.

According to the second aspect of the present invention, the set actuator speed corresponding to the manipulated variable of the control valve is compared with the actual actuator speed, and the relief pressure is set to a value corresponding to this speed difference. The actuator pressure is set high when the speed difference is large and set low when the speed difference is small.

Therefore, the actuator is started and braked with a sufficient torque, and the torque gradually decreases in accordance with the gradual decrease of the flow rate difference or the speed difference, so that the actuator can be started and stopped smoothly.

[0013]

Embodiments of the present invention will be described with reference to FIGS.

In the following embodiments, the upper swing body of the hydraulic excavator is taken as an example of the inertial body in accordance with the description of the prior art.

First Embodiment (See FIGS. 1 to 5) Reference numeral 11 is a motor for driving a revolving structure, 12 is a pump, 13 is a motor circuit constituted by both side conduits 13a and 13b. A swirl control valve 14, which is an electromagnetic proportional flow control valve with pressure compensation, is provided between the swivel control valve 12 and the swirl control valve 12, and the swivel control valve 14 is provided between a neutral position a, a right swivel position b, and a left swivel position c. The switching action controls the rotation direction and speed of the motor 11.

In addition, the motor circuit 13 includes an electromagnetic proportional relief valve (hereinafter, referred to as a relief valve) whose set pressure is changed by an electric control signal.
A relief circuit 16 provided with 15, 15 is simply connected to the relief valve. Reference numerals 17 and 17 are check valves for replenishing oil to the motor inlet side when the motor 11 is inertially rotated, and 18 is a main relief valve.

Reference numeral 19 denotes an operating body (for example, a potentiometer) for remotely operating the turning control valve 14 by operating the lever 19a. An operating signal corresponding to the lever operating direction (X, Y direction) and the operating amount of the operating body 19 is a controller. It is input to 20.

As another input signal, a signal from the flowmeter 21 provided in the motor circuit 13, that is, a detection signal of the amount of oil actually flowing in the motor circuit 13 is input to the controller 20.

Next, the operation of this apparatus including the function of the controller 20 will be described.

When the operating body 19 is operated in the X or Y direction, a control signal corresponding to the operation signal is transmitted to the controller 2
It is sent to the operating portion 14a of the turning control valve 14 from 0, and the control valve 14 strokes in the direction and amount corresponding to the operating direction and the operating amount of the operating body 19.

By the stroke operation of the turning control valve 14, a set flow rate Q proportional to the operation amount of the operating body 19 in both the X and Y directions is sent to the motor circuit 13, as shown in FIG.
In FIG. 2, S1, S2, and S3 indicate operation amounts relatively divided into three stages of small, medium, and large.

At start-up For example, at the start of right turn, the set flow rate Q is supplied to the left pipeline 13a. Since the motor 11 remains stopped by the inertia of the revolving structure at the time of starting the start,
The flow rate Qa actually flowing through the motor circuit 13 becomes 0, and this actual flow rate Qa is detected by the flow meter 21 and input to the controller 20.

The controller 20 compares the set flow rate Q with the actual flow rate Qa to obtain the difference (Q-Qa), and sets the pressure so that the set pressure of the relief valve 15 increases in proportion to this flow rate difference. The signal is sent to the operating portion 15a of the relief valve 15. This action is similarly performed when turning left.

As a result, as shown in FIG. 3, the set flow rate Q
Is proportional to the difference between the actual flow rate Qa and the relief valve 15, 15
The set pressure P of No. 1 changes between the maximum value Pmax and the minimum value Pmin, and this relief valve set pressure P acts on the motor 11 as the motor pressure.

Therefore, as shown in FIG. 4, the larger the operation amount of the operating body 19 (turn control valve 14), the larger the motor starting pressure (starting torque).

Further, after the start-up, the flow rate difference gradually decreases with acceleration, so that the relief valve set pressure P also gradually decreases in proportion to this, and when the actual flow rate Qa becomes equal to the set flow rate Q, the relief valve set pressure P is set. Becomes the minimum value Pmin, and shifts to steady operation.

When stopped: Deceleration operation for operating body 19 to stop (lever return operation)
Then, a control signal corresponding to the operation amount (operation amount from the neutral position) is sent from the controller 20 to the turning control valve 14 to perform the flow rate setting action.

Therefore, also at this time, the relief valve set pressure on the motor outlet side changes in proportion to the difference between the set flow rate Q and the actual flow rate Qa (in this case, the actual flow rate Qa is larger, so that it is a negative value). However, as the brake torque changes,
Similar to the start-up, smooth braking / stopping action is performed.

When the oil in the motor circuit 13 flows from the control valve 14 to the tank at an intermediate position between the neutral position a and the side positions b and c of the turning control valve 14, braking pressure is generated on the motor outlet side. do not do.

Therefore, as shown in FIG. 5, the meter-out flow path of the control valve 14 (the left turning position c is illustrated in the figure).
Is provided with a throttle 22 and a pressure compensating valve 23 that keeps a differential pressure across the throttle 22 constant. By the action of the pressure compensating valve 23, the relief action of the relief valves 15 and 15 can be secured. It is configured.

Second Embodiment (see FIG. 6) Only the differences from the first embodiment will be described.

In the first embodiment, the relief pressure is changed in proportion to the difference between the set flow rate of the swing control valve 14 and the actual flow rate detected by the flow meter 21, whereas in the second embodiment the relief pressure is changed. , A speed sensor 2 for detecting the rotation speed of the motor 11
4 is provided, the difference between the set motor speed corresponding to the operation amount of the swing control valve 14 in both directions and the actual motor speed detected by the speed sensor 24 is calculated, and the relief valve set pressure is proportional to the speed difference. I am trying to change.

With this configuration, the same operational effect as in the case of the first embodiment can be obtained.

In addition, in the second embodiment, in addition, as a benefit when the pump 12 is also used for an actuator other than the motor 11, an electromagnetic proportional sequence valve 26 is provided in the pressure oil supply pipeline 25 to another actuator. Is provided to change the set pressure of the electromagnetic proportional sequence valve 26 in proportion to the difference between the set motor speed (or set flow rate) and the actual speed (or actual flow rate) of the swing control valve 14.

In this way, it is possible to avoid the inconvenience that a large amount of pressure oil from the pump 11 flows into the other actuator side when the motor circuit pressure rises.

By the way, in the above embodiment, the swing control valve 14
Although the electromagnetic proportional flow control valve is used in the above, a hydraulic pilot flow control valve may be used instead. Alternatively, a manual flow control valve may be used instead of such a remotely operated valve.

In the above embodiment, the relief pressure is set in proportion to the difference between the set flow rate and the actual flow rate, or the difference between the set speed and the actual speed. You may make it set with an appropriate correspondence.

Further, the present invention is not limited to the upper revolving structure of the hydraulic excavator illustrated in the above-described embodiment, but is not limited to the general revolving structure of the revolving type working machine, and is not limited to the revolving structure. It can also be applied to various inertial bodies.

[0039]

As described above, according to the present invention, the set flow rate or speed corresponding to the manipulated variable of the control valve is compared with the actual flow rate or speed of the drive circuit to determine the relief pressure of the actuator circuit, that is, Since the actuator pressure is set to a value proportional to this difference, the actuator is started and braked with sufficient torque during start and stop operations, and the torque is gradually reduced in proportion to the gradual decrease in flow rate difference or speed difference. Can be made.

Therefore, it is possible to smoothly start and stop the inertial body.

[Brief description of drawings]

FIG. 1 is a circuit configuration diagram showing a first embodiment of the present invention.

FIG. 2 is a diagram showing a relationship between an operation amount of an operating body and a set flow rate in the embodiment.

FIG. 3 is a diagram showing changes in the set pressure of the relief valve with respect to the difference between the set flow rate and the actual flow rate in the same embodiment.

FIG. 4 is a diagram showing a relationship between elapsed time after the start of operation and motor starting pressure in the embodiment.

FIG. 5 is a diagram showing a configuration of a meter-out flow path of the turning control valve in the embodiment.

FIG. 6 is a circuit configuration diagram showing a second embodiment of the present invention.

FIG. 7 is a conventional circuit configuration diagram.

[Explanation of symbols]

11 Hydraulic Motor for Driving Swinging Body as Inertial Body 12 Pump 13 Motor Circuit 14 Swinging Control Valve 15 Relief Valve 16 Relief Circuit 19 Operation Valve (Operation Detection Means) for Remotely Operating Swinging Control Valve 20 Swinging Control Valve and Relief Valve Controller for controlling 21 Flowmeter (flow rate detecting means) 24 Speed sensor (speed detecting means)

Claims (2)

[Claims] 1. A hydraulic actuator for swinging and driving an inertial body, a relief circuit connected to a drive circuit of the hydraulic actuator, a relief valve of a preset pressure variable type provided in the relief circuit, the drive circuit and the pressure circuit. A control valve provided between the pump as an oil supply source, an operation detecting means for detecting an operation direction and an operation amount of the control valve, and a flow rate detecting means for detecting an oil amount actually flowing through the drive circuit. , A controller for controlling the set pressure of the relief valve, and the controller controls the difference between the set flow rate and the actual flow rate corresponding to the operation amount in both directions of the control valve based on the detection signals of the operation detection means and the flow rate detection means. And a drive control device for an inertial body, which is configured to output a signal that changes the set pressure of the relief valve in accordance with the flow rate difference. 2. The swing control device for a swinging structure according to claim 1, wherein a speed detecting means for detecting an actual operating speed of the hydraulic actuator is provided in place of the flow rate detecting means, and the controller controls the two directions of the control valve. The difference between the set operating speed of the actuator corresponding to the manipulated variable and the actual operating speed detected by the speed detecting means is obtained, and a signal for changing the set pressure of the relief valve is output corresponding to the speed difference. A drive control device for an inertial body characterized by being configured.