JPH11230401A - Proportional solenoid direction and flow control valve and controller thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable removal of a foreign matter within hydraulic fluid and mass flow control. SOLUTION: In a body 11 of a control valve which actuates a main valve spool 13 via a nozzle flapper mechanism composed of a flapper 16 moving as a push rod 15a of a proportional solenoid 15 moves, and of a nozzle 14 which is integral with the main valve spool 13, a position sensor 28 for detecting the traveling position of the main valve spool 13 are provided, and a stopper 27 which forms a large gap δZ between the nozzle 14 and the flapper 16 by engaging the main valve spool 13 which returns to a returning direction (right) following the movement of the flapper 16 on its way of returning are provided. The area ratio between a first pressure receiving area 13a for actuating the main valve spool 13 toward a valve opening direction (left) and a second pressure receiving area 13b for actuating the main valve spool 13 toward the returning direction is set at least 5 to 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a proportional electromagnetic directional flow control valve having a nozzle flapper mechanism comprising a flapper cooperating with an output member of a proportional electromagnetic actuator and a nozzle integrated with a main valve spool, and a control thereof. Related to the device.

[0002]

2. Description of the Related Art Conventionally, as a proportional electromagnetic type directional flow control valve of this type, for example, a nozzle / flapper position tracking type directional flow control valve as shown in FIG. 8 is known. This is because the nozzle 14 integral with the main valve spool 13 sliding in the sliding hole 12 of the body 11 of the main valve 1 in the axial direction is connected to a push rod 15a as an output member of a proportional solenoid 15 which is a proportional electromagnetic actuator. The proportional solenoid 15 is displaced along with the nozzle 14 while always maintaining a predetermined gap in the flapper 16 constituting the pilot portion. The stroke of the push rod 15 a of the proportional solenoid 15 is the same as the stroke of the main valve spool 13.

The main valve spool 13 is urged rightward in the figure by a spring 17 and the flapper 16 by a spring 18, and the positioning of the flapper 16 is determined by the urging force of the spring 18 and the thrust of the proportional solenoid 15. The first and second pressure receiving surfaces 13a of the main valve spool 13,
The pressure receiving area of the pressure receiving surface 13b is approximately 2: 1.
Pilot pressure is directly applied to 3b via the pilot pressure reducing valve 19, and pilot pressure is applied to the first pressure receiving surface 13a via the pilot pressure reducing valve 19 and the throttle 13c. The fluid that has passed through the throttle 13c is ejected from the nozzle 14 and returns to the tank via the nozzle / flapper chamber 20 and the drain line Y.

At this time, the back pressure of the nozzle becomes approximately half of the pilot pressure, the main valve spool 13 is positioned, and a controller (not shown) used for its control is used.
Can perform open loop control or closed loop control by switching a switch. 8 in FIG.
Is a manual push rod for manually moving the armature 15b of the proportional solenoid 15, 22 is a zero adjustment screw for the manual push rod 21, and in the case of a valve with a position sensor, a position sensor is connected to the proportional solenoid 15 instead of these. Comes with.

[0005]

However, in such a conventional proportional electromagnetic directional flow control valve, in order to improve the controllability up to the low frequency range, the nozzle and the flapper must be connected in a low input state. I couldn't open the gap widely.
As a result, even if a relatively large foreign matter is mixed in the working fluid, the working fluid cannot escape from the gap between the nozzle and the flapper, which may lead to repeated performance failure. Further, since the spool pressure receiving area ratio is 2: 1, there is a limit to the driving force when the valve is opened, and the limit value for the large flow rate control is determined by the fluid force.

Further, in the valve control device, since the open-loop control and the closed-loop control of the controller are manually switched, there is a problem in operability. The present invention has been made in view of the above points, and provides a proportional electromagnetic directional flow control valve and a control device therefor that prevent repetitive performance deterioration due to foreign matter in a working fluid and enable large flow control. The purpose is to:

[0007]

In order to achieve the above object, the present invention provides a nozzle flapper mechanism comprising a flapper cooperating with an output member of a proportional electromagnetic actuator and a nozzle integral with a main valve spool. A proportional electromagnetic directional flow control valve that transmits the movement of the output member to the main valve spool via the main valve spool. The stopper locks the main valve spool moving in the return direction following the movement of the flapper during the return. And a proportional electromagnetic directional flow control valve provided with a position sensor for detecting a movement position of the main valve spool.

In the above proportional electromagnetic directional flow control valve, the area ratio between the first pressure receiving surface for driving the main valve spool in the valve opening direction and the second pressure receiving surface for driving the main valve spool in the valve closing direction is 5%. : It is preferable to set to 2 or more.

In the above-mentioned control device for a proportional solenoid type directional flow control valve, when the input voltage to an analog input controller for controlling the proportional solenoid type directional flow control valve is smaller than a predetermined value, open loop control is performed. Also provided is a control device for a proportional electromagnetic directional flow control valve which is automatically switched to closed loop control when the value is larger than the predetermined value.

Further, in the control device for a proportional solenoid type directional flow control valve, when a plurality of switching signals are not all inputted to a controller having a setting device for controlling the proportional solenoid type directional flow control valve. It is also possible to automatically switch to open loop control and to closed loop control when a switching signal is input.

In the proportional electromagnetic directional flow control valve having the above-described configuration, a large foreign matter is mixed in the working fluid by opening the gap between the nozzle and the flapper in an initial state. However, when controlling the flow rate,
It can be drained from the gap between the flapper.

In the above proportional electromagnetic directional flow control valve, when the area ratio of the first and second pressure receiving surfaces of the main valve spool is set to be larger than 2: 1 and 5: 2 or more, the main valve spool is provided. The driving force in the valve opening direction can be increased to counter the fluid force, and a large valve can be controlled with a small valve.

[0013] Also, a control device for controlling the control device for the proportional electromagnetic directional flow control valve by an analog input controller. If the value is larger than the predetermined value, the control can be automatically switched to the closed loop control, so that the input and the output can be made approximately 1: 1 in all the control areas, and the dead zone on the control flow rate characteristic with respect to the input can be substantially reduced. Can be eliminated.

Further, a control device for controlling the control device of the proportional electromagnetic directional flow control valve by a controller with a setting device, wherein when no switching signal is inputted, the switching signal is switched to open loop control. When is input, closed-loop control can be automatically switched, so that the switching can be performed more simply and with higher accuracy.

[0015]

Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a side sectional view showing an embodiment of the present invention, and portions corresponding to FIG. 8 are denoted by the same reference numerals, and description thereof will be omitted.

The proportional electromagnetic directional flow control valve (hereinafter abbreviated as "control valve") 100 is provided with a drain communication oil chamber 23 provided at the left end of the sliding hole 12 of the body 11 of the main valve 1 in FIG.
Is communicated with the tank via the drain line Y together with the nozzle / flapper chamber 20.
The first and second oil chambers 24 and 25 are provided inside the oil communication chamber 23 and the drain communication oil chamber 23, respectively. The pilot pressure is introduced into the first oil chamber 24 via the pilot pressure reducing valve 19 and the throttle 26, and the pilot pressure is introduced into the second oil chamber 25 only via the pilot pressure reducing valve 19, and the main valve spool The area ratio of the first pressure receiving surface 13a to the second pressure receiving surface 13b is set to 5: 2 or more, which is larger than the conventional one.

A stopper 27 is provided at the right end of the sliding hole 12.
When the main valve spool 13 integrated with the nozzle 14 returns following the rightward movement of the flapper 16, the main valve spool 1
3, the first pressure receiving surface 13a abuts against the stopper 27 and its return is locked, and in a state where there is no input of the proportional solenoid 15, an initial gap ΔZ is formed between the nozzle 14 and the flapper 16 as shown in the figure. The position of the stopper 27 is set such that The annular groove 12 formed in the body 11
Primary inputs are input to p and 12t via inlet ports P and T, and secondary outputs are output to annular grooves 12a and 12b via outlet ports A and B. Position sensor 28 for detecting the movement position of valve spool 13
Is provided.

The control valve 100 has the above-described configuration, and the input current to the proportional solenoid 15 is zero as shown in FIG.
In the state (1), the flapper 16 is at the right end by the urging force of the spring 18. The pilot pressure oil that has flowed into the first oil chamber 24 flows out into the nozzle flapper chamber 20 through the through hole 14a of the nozzle 14, and is discharged to the drain line Y. The hydraulic pressure in 24 is
Is much lower than the hydraulic pressure in the second oil chamber 25 to which the pilot pressure oil is supplied.

Therefore, the main valve spool 13 moves to the right by the pilot oil pressure supplied to the second oil chamber 25, is locked at a position where the first pressure receiving surface 13a is in contact with the stopper 27, and the nozzle 14 and the flapper An initial gap ΔZ larger than that of the conventional fluid is formed between the hydraulic fluid and the hydraulic fluid, so that a large foreign substance mixed in the working fluid can flow out.

When power is supplied to the proportional solenoid 15 from this state, the flapper 16 is displaced to the left via the push rod 15a, and the gap between the flapper 16 and the nozzle 14 is thereby sandwiched. A thrust is generated to shift 13 to the left. At this time, the main valve spool 1
If the pressure receiving area ratio of 3 is 5: 2, the main valve spool 13 moves to the left until the nozzle back pressure becomes 40% of the pilot pressure, and if the pressure receiving area ratio is 3: 1, the nozzle back pressure becomes The main valve spool 13 moves leftward to a position where the pilot pressure becomes 33% of the pilot pressure.

That is, for example, by setting the pressure receiving area ratio of the main valve spool 13 to 5: 2, the pressure receiving area ratio becomes 2: 1.
If the nozzle back pressure is 50% of the pilot pressure as compared with the conventional control valve, the driving force increases by 25% and the driving force of the main valve spool 13 to the left becomes stronger, A large flow rate control against the fluid force becomes possible, and the contamination effect is also improved in combination with the engagement of the stopper 13 by the stopper 27.

Next, FIG. 2 is a control symbol diagram of the control valve 100, and FIG. 3 is a basic configuration diagram thereof. 2, the controller 3 receives an input signal and a position signal from the position sensor 28, and outputs the output current I to the proportional solenoid 15.
Supply. The spool 13 shown in FIG. 1 moves to the left in proportion to the magnitude of the output current I, the secondary output is output from the outlet ports A and B, and the cylinder 4 as an actuator is driven.

In FIG. 3, when a control current I is input from the controller 3 (FIG. 2) to the proportional solenoid 15, a thrust proportional to the current I is generated, and the pilot pressure is changed to the nozzle / flapper position following type hydraulic pressure. When input to the pilot section 2 constituting the amplifying mechanism, the main valve spool 13 of the main valve 1 constituting the flow rate control section moves, and pressurized oil flowing from the inlet ports P, T is supplied from the outlet ports A, B to the actuator. To the cylinder 4 (FIG. 2). At this time, the movement position of the main valve spool 13 is fed back to the controller 3 from the position sensor 28 through a sensor circuit.

In the control valve 100 shown in FIG. 1, when the input to the proportional solenoid 15 is large,
The main valve spool 13 moves following the flapper 16, but when the input to the proportional solenoid 15 is small, the main valve spool 13 is locked by the stopper 27 and cannot follow the flapper 16. Therefore, the controller 3 that controls the control valve 100 normally performs closed-loop control of the position of the main valve spool 13 with respect to the input voltage, but when the input voltage to the controller 3 is extremely small, the controller 3 Automatically becomes open loop control, so that the space between the nozzle 14 and the flapper 16 can be greatly opened.

FIGS. 4 and 5 are block diagrams showing the configuration of a control device for automatically switching between closed loop control and open loop control. FIG. 4 shows a case where an analog input controller is used. , A case where a controller with a setting device is used.

In the case of the analog input shown in FIG. 4, the comparison value Vc comprising the input voltage Vi and the minute potential is applied to the comparator 3
1, the switching output A or / A is output. When the input voltage Vi is smaller than the comparison value Vc, the switching output A is high, the switching output / A is low, and the input voltage Vi is the comparison value. When it is larger than Vc, the switching output A is low and the switching output / A is high. When the switching output A is high, the first analog switch 32 is on and the second analog switch 33 is off. When the switching output / A is high, the first analog switch 32 is off and the second analog switch 32 is off. The second analog switch 33 is on. Note that "/" before the switching output A means inversion, and is shown with an overline in the figure.

In such an analog input controller, when the input voltage Vi is smaller than the comparison value Vc, the first
Is turned on and the second analog switch 33 is turned off, the input voltage Vi is applied to the first analog switch 32 and the adder irrespective of the feedback voltage Vf from the position sensor 28 of the main valve spool 13. 3
4, an output current I corresponding to only the input voltage Vi is input to the proportional solenoid 15 via the voltage / current converter 35,
It becomes open loop control.

When the input voltage Vi is larger than the comparison value Vc, the first analog switch 32 is turned off and the second analog switch 33 is turned on.
And the feedback voltage Vf from the position sensor 28 are input to a subtractor 36, and the difference is taken. The difference is improved in accuracy by a compensation circuit 37, and the second analog switch 33, adder 34, voltage / The output current I is input to the proportional solenoid 15 via the current converter 35, and the closed loop control is performed.

Next, in the case of the controller with a setting device shown in FIG. 5, the setting device 38 can set a plurality of setting signals S1 to S5 of, for example, five channels.
Channel switching signals C1 to C5 can be input. When all of the five channel switching signals C1 to C5 are not input, the analog switching output A is high,
Becomes low, and when the switching signals C1 to C5 are input, the switching output A becomes low and / A becomes high. The subsequent configuration is the same as that of FIG. 4. Open loop control is performed in the former case and closed loop control is performed in the latter case.

FIGS. 6A and 6B are diagrams showing the current-flow rate characteristics and the current-main valve spool position control characteristics when the control valve 100 according to the present invention is subjected to open loop control, and FIG. FIGS. 7A and 7B are diagrams showing an input voltage-flow rate characteristic and an input voltage-main valve spool position control characteristic when closed loop control is performed. In addition, (a) of FIG.
7B, the horizontal axis represents the current I, and the vertical axis represents the flow rate Q, the main valve spool position S, and the flapper position (dashed-dotted line). In FIGS. 7A and 7B, the horizontal axis represents the current. Input voltage V
The vertical axis shows the flow rate Q, the main valve spool position S, and the flapper position (dashed line).

As can be seen from FIG. 6, in the case of the open-loop control, the flow rate Q is zero until the current I reaches a predetermined value, and thereafter increases almost in proportion to the current I.
When the value decreases, a slight hysteresis phenomenon occurs, and the value decreases along a different path from that when the value increases. On the other hand, in the main valve spool position S, the position of the main valve spool 13 changes substantially in proportion to the current I.

In the case of the closed-loop control shown in FIG. 7, the input voltage V is a small potential ΔV (for example, ΔV / V
Since the open-loop control is performed up to (max = 0.005), the flow rate Q is zero, but thereafter increases in proportion to the input voltage V. When the voltage decreases, the flow rate Q decreases without a hysteresis phenomenon. On the other hand, the main valve spool position S increases almost in proportion to the input voltage V by the open loop control until the input voltage V reaches the minute potential ΔV, but when the input voltage V reaches the minute potential ΔV, the main valve spool position S closes from the open loop control to the closed potential. Since the control is switched to the loop control, the flapper position moves instantaneously by S1 and thereafter changes in proportion to the input voltage V.

[0033]

As described above, the first aspect of the present invention is as follows.
According to the proportional electromagnetic directional flow control valve described above, large foreign matters mixed in the working fluid that cannot pass in the normal operating state can easily flow out from between the nozzle and the flapper that are largely opened in the initial state, and contamination can be easily achieved. The repetition performance can be kept good by improving the nation.

According to the proportional electromagnetic directional flow control valve of the second aspect, in addition to the above-described effects, the driving force for driving the main valve spool in the valve opening direction can be increased to oppose the fluid force. A large flow rate can be controlled with a small valve.

According to the control device for the proportional electromagnetic directional flow control valve according to the third aspect, the closed-loop control and the open-loop control are automatically switched according to the magnitude of the input voltage, so that the input and the output are almost always constant. The control can be performed so as to be 1: 1 and the dead zone of the control flow characteristic with respect to the input can be eliminated. According to the control device for the proportional electromagnetic directional flow control valve according to the fourth aspect, it is possible to automate the control with higher precision.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing one embodiment of a proportional electromagnetic directional flow control valve according to the present invention.

FIG. 2 is a control symbol diagram of the control device.

FIG. 3 is a basic configuration diagram of the same.

FIG. 4 is a circuit diagram showing an example of a specific circuit for switching between open-loop control and closed-loop control when an analog input controller is used for the control.

FIG. 5 is a circuit diagram showing an example of a specific circuit for switching between open-loop control and closed-loop control when a controller with a setting device is used for the control.

FIG. 6 is a diagram showing current-flow rate characteristics, current-main valve spool position characteristics, and flapper position characteristics during the open loop control.

FIG. 7 is a diagram showing an input voltage-flow rate characteristic, an input voltage-main valve spool position characteristic, and a flapper position characteristic during the closed loop control.

FIG. 8 is a side sectional view showing an example of a conventional proportional electromagnetic directional flow control valve.

[Explanation of symbols]

 1: Main valve 2: Pilot section 3: Controller 11: Body 12: Sliding hole 13: Main valve spool 13a: First pressure receiving surface 13b: Second pressure receiving surface 14: Nozzle 15: Proportional solenoid 16: Flapper 19: Pilot pressure reducing valve 20: Nozzle / flapper chamber 27: Stopper 28: Position sensor 31: Comparator 37: Compensation circuit 100: Proportional electromagnetic directional flow control valve

Claims (4)

[Claims] 1. A proportional valve for transmitting the movement of the output member to the main valve spool via a nozzle flapper mechanism comprising a flapper cooperating with an output member of a proportional electromagnetic actuator and a nozzle integral with the main valve spool. In the electromagnetic directional flow control valve, a stopper that locks the main valve spool, which moves in the return direction following the movement of the flapper, during its return,
A proportional electromagnetic directional flow control valve, further comprising a position sensor for detecting a movement position of the main valve spool. 2. The proportional electromagnetic directional flow control valve according to claim 1, wherein an area of a first pressure receiving surface that drives the main valve spool in a valve opening direction and a second pressure receiving surface that drives the main valve spool in a valve closing direction. A proportional electromagnetic directional flow control valve, wherein the ratio is set to 5: 2 or more. 3. The control device for a proportional electromagnetic directional flow control valve according to claim 1, wherein an input voltage to an analog input controller for controlling the proportional electromagnetic directional flow control valve is smaller than a predetermined value. A control device for a proportional electromagnetic directional flow control valve, characterized in that the control is automatically switched to open loop control when the value is larger than the predetermined value and to closed loop control when the value is larger than the predetermined value. 4. The control device for a proportional electromagnetic directional flow control valve according to claim 1, wherein a plurality of switching signals to a controller having a setting device for controlling the proportional electromagnetic directional flow control valve are all provided. A control device for a proportional electromagnetic directional flow control valve, wherein the control is automatically switched to open-loop control when not input and to closed-loop control when the switching signal is input.