JPS62255604A - Rotary servo valve and its control system - Google Patents

Abstract

PURPOSE:To improve the responsibility and minute flow rate controllability of a servo valve by inserting valve members which are connected with the first and the second rotary driving body, and establish valve openings according to the relative rotating angles of both the said rotary driving bodies in a valve main body. CONSTITUTION:A valve member 1 which is connected with the first and the second motor M1, M2, and establishes a valve opening communicating with load ports C1-C4 according to the relative rotating angles of the said motors is inserted in a valve main body 3. Since the said relative rotating angles can be therefore controlled by adjusting the rotating angle of the said motors, the valve opening can be extremely smoothly and quickly adjusted to improve the responsibility of the valve. In addition to that, since the relative rotating angle is controlled by means of a time function, infinitesimally divided time in the said function can make the control of a minute flow rate possible.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a rotary servo valve whose opening degree is adjusted in accordance with the drive of a rotary drive body, and a control method thereof.

[Conventional technology]

Most conventional servo valves are direct-acting spool valves, and the spool is driven by an electro-hydraulic amplifier consisting of a torque motor and a hydraulic nozzle/flapper valve.

[Problems to be Solved by the Invention] In the case of a spool valve, the valve opening degree is controlled by the reciprocating motion of the spool, so there is a limit to responsiveness. That is, normally, the servo valve is not completely stationary at the desired valve opening, but reciprocates back and forth, eventually tracking the desired valve opening on an average. Therefore, the spool constantly repeats slight inversions, stopping, accelerating, and decelerating each time, and the single frequency response is always a problem. Further, in the case of a flapper valve, on/off control is performed according to the swinging of the flapper, and it has been impossible to control a flow rate smaller than the flow rate corresponding to a constant on time.

This invention was made in view of the above points, and by providing a new rotary servo valve and its control method,
The purpose is to achieve high response performance and minute flow control that were previously unobtainable.

[Means for solving problems]

The rotary servo valve according to the present invention includes first and second rotary driving bodies rotationally driven by an electric signal, a valve body having a fluid supply port, a return port, and a load port, and a valve body that is inserted into the valve body. and a valve member coupled to the first and second rotary driving bodies to set the opening degree of the valve communicating with the load port according to the relative rotation angle between the first and second rotary driving bodies. do.

The control system according to the present invention controls the flow rate of the above-mentioned rotary servo valve by controlling the relative rotation angle of the first and second rotary driving bodies as a function of time. It is characterized by

[Effect]

The first and second rotationally driven bodies are each independently rotationally driven in response to an electric signal. The valve member is connected to a single-rotation driver, and the valve member is moved in response to driving of the one-rotation driver inserted into the valve body.

The position of the valve member is determined according to the relative rotation angle between the re-rotation drive bodies, and the valve opening degree is set.

The relative rotation angle between the rotary drive bodies can be controlled by adjusting the rotation angle of both rotary drive bodies, and this control is not an on/off switching control as seen in a flapper valve. Therefore, the valve opening degree can be adjusted extremely smoothly and quickly, and responsiveness can be improved.

Further, according to the control method of the present invention, the relative rotation angle between the two rotary drive bodies is controlled as a function of time. By minimizing the time required to set the relative rotation angle corresponding to the minimum possible valve opening, it is possible to control a small flow rate.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a longitudinal sectional view of a first embodiment of a rotary servo valve according to the present invention. The first and second motors M1 correspond to rotary driving bodies that are rotationally driven by electric signals.
, M2. The motors M1 and M2 may be analog motors driven by AC or DC electrical analog signals, or digital motors such as pulse motors, and are not limited to general motors; A rotary drive body such as the following may also be used.

A first rotary valve member 1 is connected to the rotation shaft of the first motor M1, and a second rotary valve member 2 is connected to the rotation shaft of the second motor M2. 2 has a cylindrical shape, member 1 is nested inside member 2,
They are each rotatably housed in the valve body 3. Valve body 3 is oil supply port S.

It is equipped with a return port R1, a load port C1, C2, C3°C4.

A first chamber 4 and a second chamber 5 are formed inside the inner rotary valve member 1 via a partition wall 1e, and the first chamber 4 is always connected to the oil supply port S of the valve body 3 and serves as a oil supply chamber. It becomes. The second chamber 5 is open at one end and communicates with the internal chamber of the outer rotary valve member 2, and is also constantly communicated with the return port R of the valve body 3 to form a return chamber. A cross section taken along the line ■-■ of the portion corresponding to the oil supply port S is shown in Fig. 2, and the ring-shaped flow path 6 consisting of a ring-shaped groove space surrounding the rotary valve member 1 is located on the valve body 3 side. It is formed.

This communicates with the refueling port S. An appropriate number (2 in the figure) of openings 1s are provided in a predetermined angular range on the wall surface of the rotary valve member 1 at positions corresponding to the ring-shaped flow path 6.
This opening 1s communicates with the oil supply chamber 4. Therefore, no matter how the rotary valve member 1 rotates, the oil supply port S and the oil supply chamber 4 are always in communication via the ring-shaped flow path 6 and the opening 1s. tu at the location corresponding to return port R
The cross section taken along the -ut line is as shown in FIG. 3, and as described above, the ring-shaped flow path 7 leading to the return port R is formed in the valve body 3, and the second rotary valve member 2 is provided with an opening 2r. , the return port R and the return room 5 are always in communication.

A at a location corresponding to each load port C1 to C4.

The cross-sectional views taken along lines B, C, and D are shown in FIGS. 4 and 5. Although FIG. 4 is a cross-sectional view taken along line A at a location corresponding to load port C1, the cross section taken along line D at a location corresponding to C4 also has the same shape. Although FIG. 5 is a Bi cross-sectional view of a portion corresponding to load port C2, the C-line cross section of a portion corresponding to C3 also has the same shape. The valve body 3 has a ring-shaped flow path 8 , which is a ring-shaped groove space surrounding the outer rotary valve member 2 . '9,
10.degree. 11 is formed corresponding to each load port 01-C4, and this communicates with each corresponding load port 01-C4, respectively. The walls of each rotary valve member 1, 2 have openings 1a, lb, lc, ld, 2a, 2b, 2c, 2d (
2a to 2d are not shown in FIG. 1 because they are out of the longitudinal section), and the openings 1a of the inner valve member 1 are provided.

1b communicates with the oil supply chamber 4, and openings 1c and ld communicate with the return chamber 5. The openings 2a to 2d of the outer valve member 2 face the ring-shaped channels 8 to 11, respectively, and each opening 20 to 2d faces each load port 0, no matter what rotational position the valve member 2 is in.
1 to C4. Therefore, the openings 1a to 1d of the first valve member 1 and the openings 2a to 1d of the second valve member 2
The valve opening degrees between the refueling chamber 4 and the return chamber 5 and the negative Qi boats C1 to C4 are determined according to the degree of overlap with the negative Qi boats C1 to C4.

Specifically, a first load port C1 corresponding to the oil supply chamber 4 and a third load port C3 corresponding to the return chamber 5 communicate with each other, and are connected to a first port of a load device (for example, a hydraulic cylinder 12). Ru. Also.

Second load port C2 corresponding to oil supply chamber 4 Return chamber 5
A fourth load port C4 corresponding to the hydraulic cylinder 12 is connected to the second port of the hydraulic cylinder 12, which is a load device. In the first rotary valve member 1, first and fourth openings 1a corresponding to the first and fourth load ports C1 and C4,
ld are provided at the same angular position as shown in FIG.
The third openings 1b and lc are also provided at the same angular position as shown in FIG. Moreover, the second rotary valve member 2
Also, the first and fourth openings 2a correspond to the first and fourth load ports C1 and C4.

2d are provided at the same angular position as shown in FIG.
The third openings 2b and 2c are also provided at the same angular position as shown in FIG.

In addition, although each port S, R, and C1-c4 were shown to be in the same angular position in the figure, it is needless to say that it is not limited to this.

A group of first and fourth openings 1a, 2a, ld, 2d corresponds to a first valve position, a second and third opening 1
Groups b, 2b, lc, and 2c correspond to the second valve position. That is, when the first and fourth openings 1a, 2a, ld, and 2d overlap between the circumferential valve members 1 and 2, the second and third openings 1b, 2b, lc, and 2c are prevented from overlapping ( At this time, a flow path is formed in the direction of the solid line arrow in Figure 1), and the second and third openings 1by
When openings 2b, lc, and 2c overlap, the first and fourth openings 1a, 2a, ld, and 2d do not overlap (at this time, a flow path is formed in the direction of the dashed arrow in Figure 1).
The angular deviation of the corresponding openings between the two rotary valve members is predetermined between the first and fourth opening groups la, 2a, ld, 2d and the second and third opening groups lb, 2b, lc, 2c. The openings are arranged at different angles. In the illustrated example, the openings 1a to 1d of the inner rotary valve member 1 are all provided at the same angular position, and the first and fourth openings 2a, 2d and the second and third openings of the outer rotary valve member 2 are provided at the same angular position. openings 2b, 2
c are provided approximately 180 degrees apart (see Figures 4 and 5).
(see figure). Therefore, the first and fourth aperture groups la,
2a, ld.

The angular deviation between the valve members 1 and 2 with respect to 2d (corresponding to the overlapping degree of the openings) is the difference between the second and third opening groups l.
Approximately 180 degrees for the angular deviation (corresponding to the degree of overlapping of the openings) between the valve members 1 and 2 with respect to b, 2b, lc, and 2c.
The degree is off. As a result, one aperture group la,
When 2a, ld, and 2d are connected, the other one is always closed,
A flow path (actual arrow in FIG. 1) flowing from the load port C1 to the load cylinder 12 and flowing into the load port C4 is formed, and the other opening group 1 b + 2 b p 1
c *When 2c is connected, one side is always closed, and it flows from load port C2 to load cylinder 12 and is connected to load port C.
A flow path (dashed line arrow in FIG. 1) flowing into No. 3 is formed.

The angular range in which each of the openings 1a to ld and 2a to 2d is open is approximately 90 degrees. As a result, the rotary valve member 1
, 2 is rotated 180 degrees relative to the other (while the other aperture group remains closed), and the remaining 180
The overlap of the other aperture group is controlled over a relative rotation range of degrees (while one aperture group remains closed). This point is illustrated in Figures 6(a) to 6(d), where the relative rotation angle of the first rotary valve member 1 with respect to the second rotary valve member 2 is 0 degrees (a). 360 degrees), (
90 degrees in b), 180 degrees in (Q), 27 degrees in (d)
It is 0 degrees. That is, as shown in (a), (b), and (c), the aperture groups 1a, 2a, ld, and 2ci communicate in the relative rotation angle range of 0 degrees to 180 degrees;
(d).

As shown in (a), the aperture groups lb, 2b, lc, and 2c communicate in the range from 180 degrees to 360 degrees. The angular range of each opening can be set any number of times as long as it is less than 90 degrees.

The degree of opening of the valve is determined by the relative rotational positional relationship between the single-rotation valve members 1 and 2, that is, the relative rotational angle.

For example, the relative positional relationship between the two is shown in Figure 6 (a) Force 1 et al (b
), one valve opening degree (openings 1a, 2a and ld
, 2d overlap) can be controlled from 0% to 100%, in the range (b) to (c) it is controllable from 100% to 0%, and in the range (C) to (d) the other Valve opening (opening 1b.

2b, lc, and 2c) can be controlled from 0% to 100%, and in the range from (d) to (a), the overlap is 100%.
The rotation of the six-turn valve members 1 and 2, which can be controlled from % to 0%, can be controlled in any manner as long as the desired valve opening degree can be achieved in the end. For example, hold one side still.

For example, only the other side can be rotated, or forward and reverse rotation can be performed arbitrarily. However, in order to achieve high response performance, it is most preferable to control the circumferentially rotating valve members 1 and 2 so that they always rotate in the same direction. For example, if both members 1 and 2 are rotated counterclockwise in FIG. 6, from (a) to (b)
), the inner valve member 1 is rotated when the valve opening is increased, the outer valve member 2 is rotated when the valve opening is decreased,
In the range from (b) to (C), rotating the inner valve member 1 reduces the valve opening, and rotating the outer valve member 2 increases the valve opening. This is shown in an enlarged development view as shown in Fig. 7, and when it is desired to increase the valve opening from the state shown in (a), the valve member 1 is rotated an appropriate amount in one direction to change the relationship between the openings 1a and 2a (
If it is desired to reduce the valve opening degree from this state as shown in b), the valve member 2 is rotated in one direction by an appropriate amount to bring the relationship between the openings 1a and 2a as shown in (c). In this way, the rotating valve member 1°2
By rotating the valve in one direction, it is possible to follow the desired valve opening (fine adjustment of the valve opening).

Therefore, when finely adjusting the increase or decrease of the valve opening, which is always required in servo valve control, there is no need for mechanical reversal movement at all, and control of the increase or decrease of the valve opening can always be achieved by unidirectional movement, so the response is Performance increases dramatically. Of course, the one-turn valve members 1 and 2 do not absolutely have to be reversed; for example, when switching the valve position, there is no problem even if the valve members 1 and 2 are reversed.

Rotary valve members 1 and 2, valve body 3, ring-shaped channels 6 to 11,
Openings 1a to 1d, 1s, 2a to 2
The structures and shapes of d and 2r are not limited to those shown in the drawings.

Various modifications are possible. Moreover, the drive is not limited to hydraulic drive, and may be driven by pneumatic pressure or other fluid pressure.

Note that, like a normal servo valve, means is of course provided for returning the valve to the neutral position when it is off. This means comprises, for example, a spring 13 fixed at one end to the valve member 1 and at the other end to the valve member 2, as shown in FIG.

FIG. 8 shows another embodiment of the servo valve according to the present invention using a rotary valve member. A first rotary valve member 14 is coupled to a first motor M1.

A second rotary valve member 1°5 connected to the second motor M2 is fitted, and these are inserted into the valve body 16.

Inside the valve body 16, ring-shaped flow paths SR, RR, and CAR are formed of ring-shaped groove spaces.

C2R is provided corresponding to each port S, R, C1, and C2. Four grooves 14a, 14b, 14c, and 14d are provided on the side surface of the inner rotary valve member 14 at intervals of 90 degrees. The outer rotary valve member 15 has passages SP and RP penetrating its wall surface.

One pair each of CIP and C2P are provided.

One pair (e.g. CIP) consists of two passages 180 degrees apart, and each pair consists of CIP, S
P, C2P, and RP are arranged in this order, shifted by 45 degrees. Each aisle CIP, SP.

The inner ports of C2P and RP are the inner rotary valve member 14a=
It opens at a position corresponding to 14d, and the outer openings are ring-shaped channels CIR and SR corresponding to each other.

It opens at positions corresponding to C2R and RR.

A passage CIP communicating with load ports C1 and C2.

A passage SP communicating with the supply port S and a passage RP communicating with the return port R are located on both sides of C2P. The width of the grooves 14a to 14d of the inner rotary valve member 14 is 3 at the same time.
It is designed so that it does not cover the mouth of the two aisles. In the state shown in FIG. 9, it is in the neutral position, and the flow paths to the load ports C1 and C2 are closed. When the rotary valve member 14 rotates relatively counterclockwise from this state, the grooves 14a, 14. The passage sp and CIP communicate with each other via c, and the passages SP and C2P communicate with each other via grooves 14b and 14cl. This results in a state in which the load exits from the load port C1 and enters from the load port C1. The rotary valve member 14 is moved relatively counterclockwise by 45 degrees from the position shown in the figure.
Once rotated, the valve closes. When further rotated counterclockwise from here, the groove 14a.

Passage sp and C2P communicate through 14c, and grooves 14b and 1
Passage RP and CIP come to communicate via 4d. This results in a state in which the load exits from the load port C2 and enters C1. In this way, the switching position of the servo valve is set according to the relative rotation angle of the circumferentially rotating valve members 14 and -15,
And the valve opening degree is adjusted. Motor M 1 as in the first embodiment described above.

If the direction of rotation of M2 is constant, response performance can be improved.

In FIGS. 10 and 11, the valve member inserted into the valve body 17 is a spool 18.

In FIG. 10, one end of the spool 18 is coupled to a motor M1 via a threaded coupling 19, and the other end is coupled to a motor M2 via a spline coupling 20.

The rotation of the motor M1 in a predetermined direction causes the spool 18 to move linearly in a predetermined direction (for example, the direction of arrow X), and the rotation of the motor M2 in a predetermined direction causes the spool 18 to move linearly in the opposite direction. In this case as well, the spool 18 can be moved left and right while the motors M1 and M2 are always rotating in only one predetermined direction to switch the valves and adjust the valve opening degree.

Therefore, high response and fine adjustment are possible. FIG. 11 is almost the same as FIG. 10, and the only difference is that a gear connection 21 is used instead of the spline connection 2o.

Although not shown in the embodiments shown in FIGS. 8 to 11, springs and the like for returning to the neutral position are appropriately provided.

FIG. 12 shows an example of a numerical control system using the servo valve 22 of the present invention. A fluid pressure actuator 23 is connected to the load boat of the servo valve 22, and its position and speed are detected by a detector 24. and is given to the deviation calculator 25. A program setter 26 sets a numerical control program, and target data corresponding to the numerical control program set under the control of a microcomputer 27 is supplied. The deviation calculator 25 calculates the supplied target data and the feedback data of the controlled object detected by the detector 24, and outputs the deviation data. The pulse supply circuit 28 supplies drive pulses to the pulse motors Ml and M2 of the servo valve 22 according to the deviation data, and
Controls the operation of 2.

For example, the pulse supply circuit 28 outputs an up pulse first when the fluid pressure actuator 23 should be moved in the forward direction, and outputs a down pulse first when the fluid pressure actuator 23 should be moved in the opposite direction, depending on the sign of the deviation data. . For example, the up pulse is always supplied to the first motor M1, and in response, the motor M1 is always rotated in only one predetermined direction. Further, the down pulse is always supplied to the second motor M2, and in response, the motor M2 is always rotated only in one predetermined direction. As shown in the figure, it has the effect of increasing or decreasing the relative rotation angle of both motors.

For example, when moving the fluid pressure actuator 23 in the forward direction, an appropriate number of up pulses are applied to the motor M1, and the relative rotation angle is appropriately set. When stopping the movement of the actuator 23, the same number of down pulses are applied to the motor M2, the relative rotation angle is set to O, and the valve is closed.

When moving the fluid pressure actuator 23 in the opposite direction, an appropriate number of down pulses are applied to the motor M2, and the relative rotation angle is appropriately set. To stop the movement of the actuator 23, give the same number of up pulses to the motor M1, set the relative rotation angle to O, and close the valve.

Regardless of whether the actuator 23 is moved forward or reverse, or how the increase or decrease of the valve opening is controlled, the motor M
The rotation directions of l and M2 do not change and are always in a constant direction.

Therefore, since there is no reversal movement of motor Ml, 3/12,
High responsiveness can be ensured.

The minute current can be controlled by controlling the relative rotation angles of the motors Ml and M2 in a minute time. That is, as shown in FIG.
The minute current is controlled by controlling with □. In this case, the valve opening corresponding to the relative rotation angle corresponding to one pulse drive of the motor M1 is set only for a minute time t1,
The current is an integral value of only the minute time t1 of the valve opening.

By making such minute flow rate control possible, the control precision of the load actuator 23 can be improved.

〔Effect of the invention〕

As explained above, according to the present invention, it is possible to improve the response performance, and it is also excellent in minute flow axis control, and it is possible to improve the control 2 degree. be effective.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view showing an embodiment of a rotary servo valve according to the present invention, FIG. 2 is a cross-sectional view taken along the line ■-■ in FIG. 1, and FIG. 3 is a cross-sectional view taken along the line ■-■ in FIG. 4 is a cross-sectional view taken along line A in FIG. 1, showing the same shape as the cross-sectional view taken along line D, and FIG. 5 is a cross-sectional view taken along line B in FIG. 1. It is a rr view, and C! J.A.
FIG. 6 is a cross-sectional view illustrating the relative rotational positional relationship of the first and second rotary valve members in the same embodiment, and FIG. 7 is a cross-sectional view showing the opening of the circumferential rotary valve member. FIG. 8 is a longitudinal sectional view showing another embodiment of the rotary servo valve of the present invention; FIG.
The figures are a cross-sectional view of the servo valve according to the present invention. FIG. 13 is a schematic block diagram showing one embodiment, and a timing chart showing an example of minute flow rate control. Ml, M2...first and second motors, 1, 2°14
．． 15... first and second rotary valve members, 1a to ld,
2a to 2d...Openings corresponding to each load boat, 1e.
... Bulkhead, 3, 16, 17... Valve body, 4... Oil supply chamber, 5... Return chamber, S... Fluid supply port, R...
...Return port, C1-C4...Load boat, 6-
11...A ring-shaped channel consisting of a ring-shaped groove space, 12
...Load cylinder, 18...Spool, 19...
・Screw connection, 20...Spline connection, 21...Gear connection.

Claims (1)

[Scope of Claims] 1. A valve body including first and second rotary driving bodies that are rotationally driven by an electric signal, a fluid supply port, a return port, and a load port, and a valve body that is inserted into the valve body, A rotary servo valve, comprising: a valve member coupled to the first and second rotary driving bodies and setting a valve opening degree communicating with the load port according to a relative rotation angle between both the rotary driving bodies. 2. The valve member includes: a first rotary valve member rotated by the first rotary driving body; and a first rotary valve member rotatably fitted to the first rotary valve member, and the second rotary driving body 2. The rotary servo valve according to claim 1, wherein the rotary servo valve comprises a second rotary valve member rotated by a second rotary valve member, and a valve opening degree is set according to a relative rotation angle of both rotary valve members. 3. The valve member is composed of a spool that switches the valve opening degree by linear displacement, converts the rotational movement of the first rotary drive body in a predetermined direction into a linear movement of the spool in one direction, and Claim 1, wherein the spool and the first and second rotational driving bodies are coupled through a coupling means that converts rotational movement of the rotational driving body in a predetermined direction into linear movement of the spool in the opposite direction. The rotary servo valve described. 4. A valve body having first and second rotationally driven bodies rotatably driven by an electric signal, a fluid supply port, a return port, and a load port; A control system for a rotary servo valve, comprising: a valve member coupled to a rotational driving body of the rotary driving body and setting a valve opening degree communicating with the load port according to a relative rotation angle between both the rotational driving bodies; A control method characterized in that the flow rate of the servo valve is controlled by controlling the relative rotation angle of the first and second rotary driving bodies as a function of time. 5. The control method according to claim 4, wherein the rotary driving body is a pulse motor, and the phase of the pulses applied to both pulse motors is controlled in a minute time to control a minute flow rate. 6. Claim 4, wherein a desired relative rotation angle is set by rotating the first and second rotary drives in a predetermined direction at independently controlled speeds. control method.