JPH05332318A - Controller for turning motor - Google Patents

Abstract

PURPOSE:To dissolve operator's inharmonious and distrustful feelings caused by the nondecelerating of a turning motor when the turning motor being in acceleration is decelerated. CONSTITUTION:When an operating lever 51 is operated during the stationary state of a turning motor 31, a flow control valve 4 opens, and the turning motor 31 is first accelerated in the relieved state of a relief valve 7. Even when an operator slightly moves back the operating lever 51 during acceleration to decelerate the turning motor 31, the acceleration continues in a usual device, but since in this invention, a control valve 11 is connected to a pipe line 8 for introducing a load signal into a regulator 2, and the signal of a pilot valve 52 is converted into an electric signal by a detecting device 12, and a controller 13 opens the control valve 11 according to a signal corresponding to the electric signal, pressure acting on the turning motor 31 lowers, and the turning motor 31 is decelerated consistently with the operation of the operating lever 51, and operator's inharmonious and distrustful feelings are therefore dissolved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a swing motor control device for controlling a swing motor for driving a large inertial load installed in a work machine or the like.

[0002]

2. Description of the Related Art Although various types of control means are used for controlling a swing motor for driving a load having a large inertia, a control means using a differential pressure between a discharge pressure of a hydraulic pump and a load pressure ( A control means using both so-called load sensing control means) and normal horsepower control means is often used. This control means will be described with reference to FIG.

FIG. 3 is a hydraulic circuit diagram of a conventional swing motor controller. In the figure, reference numeral 1 denotes a variable displacement hydraulic pump (hereinafter simply referred to as hydraulic pump), and 1a denotes a rearward displacement variable mechanism (hereinafter, this is represented by a swash plate). 3 is a turning device, which is a turning motor 31 to which a large inertial load is connected,
Each crossover relief valve 32 and each check valve 3
It is composed of three. 4 is a flow rate control valve interposed between the hydraulic pump 1 and the swivel device 3, 51 is an operation lever for operating the flow rate control valve 4, 52 is a pilot valve for outputting a pilot signal according to the operation amount of the operation lever 51. is there. The flow control valve 4 is driven according to the pilot signal from the pilot valve 52. Reference numeral 6 is an unload valve, and 7 is a relief valve. Reference numeral 8 is a conduit for guiding the load pressure generated downstream of the flow rate control valve 4 to the regulator 2, and 9 is a throttle interposed in the conduit 8.

Now, when the operating lever 51 is operated from the stationary state, the flow control valve 4 opens according to the operation amount, but since the swing motor 31 has a large inertia, it does not move immediately and continues the stationary state. The pressure rises. At this time, there is almost no pressure oil flow through the flow control valve 4, and the differential pressure between the pump discharge pressure and the load pressure (the differential pressure across the flow control valve 4) input to the regulator 2 is almost zero. When the pressure transmitted through the conduit 8 and the throttle 9 reaches the set pressure of the relief valve 7, the relief valve 7 is activated to relieve the pressure oil and generate a flow in the conduit 8 to generate a differential pressure. To do. Further, a part of the pressure oil is made to flow from the unload valve 6 to the tank. The swing motor 31 obtains torque by the above pressure and starts rotating, and is gradually accelerated.

During the above operation, the regulator 2 controls the swash plate 1a of the hydraulic pump 1 so as to discharge the flow rate corresponding to the pressure. That is, the control of the regulator 2 is in the horsepower control area. Therefore, the tilt amount of the swash plate 1a is extremely small. The supply amount of pressure oil increases as the swing motor 31 accelerates, the pressure decreases, the amount of pressure oil relieved from the relief valve 7 to the tank also decreases, and the opening of the unload valve 6 also decreases, finally. The entire amount of hydraulic pressure discharged from the hydraulic pump 1 is supplied to the swing motor 31.

In this state, the control of the regulator 2 enters the load sensing control area, and the swash plate 1a is connected to the flow control valve 4
The pressure difference between the front and rear is controlled so as to be the set pressure, whereby the amount of pressure oil supplied to the swing motor 31 is controlled to an amount proportional to the opening degree of the flow rate control valve 4.

[0007]

In the above apparatus, the operator operates the acceleration motor 31 when it is accelerating, and when the load sensing control is not yet started (the pressure oil is being discharged from the relief valve 7). Lever 5
Even if 1 is returned to the deceleration side by a certain amount, the pressure in the hydraulic circuit does not decrease, so that the swing motor 31 continues to accelerate. As a result, even if the operator returns the operation lever 51 to the deceleration side, the turning motor 31 does not decelerate, which makes the operator feel a lot of discomfort or distrust, which in turn increases operator fatigue and reduces work efficiency. Becomes

An object of the present invention is to solve the above-mentioned problems in the prior art, to surely respond to the deceleration operation of the operating means at the time of acceleration, and to eliminate the feeling of discomfort and distrust of the operator. To provide.

[0009]

To achieve the above object, the present invention provides a variable displacement hydraulic pump, a swing motor driven by the pressure oil of the variable displacement hydraulic pump, the variable displacement hydraulic pump, and A flow rate control valve interposed between the swivel motor, an operating means for operating the flow rate control valve, a discharge pressure of the variable displacement hydraulic pump guided through a first pipeline, and a second pipeline. In a swing motor control device including a regulator that controls the displacement volume of the variable displacement hydraulic pump based on a differential pressure with respect to the load pressure applied to the swing motor, the operating means changes from an acceleration direction to a deceleration direction. A control means for judging this when the reversing operation is performed and outputting a signal according to the operation amount in the deceleration direction, and interposed between the second pipeline and the tank and depending on the output signal of the control means. Opening, characterized in that a control valve which is controlled.

[0010]

When the operating means is reversed from the acceleration direction to the deceleration direction, the control means outputs to the control valve a signal according to the operation amount of the operating means. As a result, the control valve is opened, the input side of the swing motor is connected to the tank to reduce the pressure, and the swing motor is surely decelerated.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to illustrated embodiments. FIG. 1 is a hydraulic circuit diagram of a swing motor control device according to an embodiment of the present invention. In this figure, the same parts as those shown in FIG. Reference numeral 10 is another pipeline connected to the pipeline 8 on the upstream side of the throttle 9 and connecting the pipeline 8 and the tank, and 11 is a control valve interposed in the pipeline 10. Reference numeral 12 is a detection device that generates an electric signal proportional to the pilot signal from the pilot valve 52, and reference numeral 13 is a control device that controls the control valve 11 based on the signal of the detection device 12. The function of the control device 13 will be described with reference to FIG.

FIG. 2 is a block diagram showing the functions of the control device 13. In this figure, 131 is a block showing a function generating function for converting the input signal v from the detection device 12 into an appropriate value s proportional thereto, and 132 is a block showing a function for differentiating the output of the block 131. With the function of the block 132, the displacement amount Δs of the operating lever 51 per hour is calculated. Reference numeral 133 is a block showing a function of determining that the operating lever 51 has been returned to the deceleration side, and outputs the displacement amount Δs per hour of the operating lever 51 only when the operating lever 51 is returned to the deceleration side.

Reference numeral 134 is a block indicating an addition function, and 135
a and 135b are blocks showing a function of discriminating between positive and negative output values of the block 134, 136a ₁ and 136b ₁ are blocks showing a multiplication function, and 136a ₂ and 136b ₂ are gains K ₁ and K ₂ for positive and negative values, respectively. It is a block showing the function to do. Reference numeral 137 is a block showing an addition function, and 138 is a block showing a delay function. 139 is block 13
7 is a block showing a function generating function for converting the output value of 7 into a drive current of the control valve 11 corresponding to the output value. Block 1
The functions of 34 to 138 add a first-order delay to the signal Δs from the block 133.

When the operator operates the operating lever 51 from the stationary state of the swing motor 31, the flow control valve 4 is opened by the pilot signal of the pilot valve 52, and as described above, the swing motor 31 releases pressure oil from the relief valve 7. Acceleration is performed in the state of being maintained. On the other hand, the detection device 12 converts the pilot signal into an electric signal, and this electric signal is input to the control device 13. However, block 1 shown in FIG.
Due to the function of 33, no signal is output from the control device 13.

When the operator slightly returns the operating lever 51 in this state, the pilot signal from the pilot valve 52 decreases in response to this, and this signal is detected by the detection device 12 and input to the control device 13. The control device 13 determines that the input signal is a signal when the operation lever 51 is returned by the function of the block 133, and outputs the current i corresponding to the signal to the control valve 11 by the function of the block 139. .. As a result, the control valve 11 is opened, and the pressure oil in the pipeline 8 is discharged to the tank according to the opening degree. As a result,
The pressure applied to the swing motor 31 decreases, and the swing motor 31 does not accelerate in accordance with the operation feeling of the operator. Therefore, the operator feels something strange,
There is no distrust.

Further, since the control device 13 is provided with the first-order delay function, the opening / closing operation of the control valve 11 becomes slow,
As a result, the change in the pressure applied to the swing motor 31 also becomes gentle, and the operator's discomfort or distrust is further alleviated.

The first-order lag function of the control device 13 is not always necessary, and even if the control valve 11 is operated without the first-order lag function, the operator's discomfort and distrust can be sufficiently eliminated.

[0018]

As described above, according to the present invention, when the operating means is operated in the decelerating direction, the control valve is opened in accordance with the operation amount, the pipe line is connected to the tank, and the pressure applied to the swing motor is increased. Therefore, it is possible to eliminate the discomfort and distrust of the operator's operation.

[Brief description of drawings]

FIG. 1 is a hydraulic circuit diagram of a swing motor control device according to an embodiment of the present invention.

FIG. 2 is a block diagram showing functions of a control device 13 shown in FIG.

FIG. 3 is a hydraulic circuit diagram of a conventional swing motor control device.

[Explanation of symbols]

 1 Hydraulic Pump 2 Regulator 4 Flow Control Valve 31 Swing Motor 51 Operating Lever 10 Pipeline 11 Control Valve 12 Detection Device 13 Control Device

Claims (1)

[Claims] 1. A variable displacement hydraulic pump, a swing motor driven by the pressure oil of the variable displacement hydraulic pump, a flow control valve interposed between the variable displacement hydraulic pump and the swing motor, and the flow control. Based on a differential pressure between the operating means for operating the valve and the discharge pressure of the variable displacement hydraulic pump guided through the first conduit and the load pressure applied to the swing motor guided through the second conduit. In a control device for a swing motor including a regulator for controlling the displacement volume of the variable displacement hydraulic pump, when the operating means is reversed from the acceleration direction to the deceleration direction, it is determined and the operation amount in the deceleration direction. A control valve for outputting a signal according to the control signal, and a control valve interposed between the second pipeline and the tank, the opening of which is controlled according to the output signal of the control device. Rotation Control device of the turn motor.