JPH066961B2 - Rotary servo valve - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a rotary servo valve whose valve opening is adjusted according to the driving of a rotary drive.

[Conventional technology]

The mainstream of the conventional servo valve is a direct acting spool valve, and the spool is driven by an electrohydraulic amplifier including a torque motor and a hydraulic nozzle flapper valve.

[Problems to be solved by the invention]

In the case of a spool valve, since the valve opening is controlled by the reciprocating movement of the spool, there is a limit in responsiveness.
That is, usually, the control of the servo valve does not completely stop at the desired valve opening, but reciprocates back and forth to eventually follow the desired valve opening on average. Therefore, the spool always repeats a slight reversal, and stops, accelerates, and decelerates each time, and the frequency response always becomes a problem. Further, in the case of the flapper valve, the on / off control is performed according to the swing of the flapper, and it is impossible to control the flow rate that is smaller than the flow rate corresponding to the constant on time.

The present invention has been made in view of the above points, and an object of the present invention is to provide a novel rotary servo valve to realize a high response performance and a minute flow rate control which have not been obtained in the past. .

[Means for solving problems]

A rotary servo valve according to the present invention includes first and second rotary drive bodies that are driven to rotate by an electric signal, a supply port that supplies fluid inside, a return port that discharges the fluid outside, and a load device. A valve main body having a load port for applying the fluid, a first rotary valve member rotatably inserted in the valve main body, and rotating in response to rotation of the first rotary drive body; And a second rotary valve member that is rotatably inserted in the first rotary valve member and that rotates in response to the rotation of the second rotary drive member. The first and second rotary drive members are independent of each other. By controlling the electrical signal of the first and second rotary valve members to adjust the valve opening degree between the supply port and the return port and the load port corresponding to the relative rotational position angle of the first and second rotary valve members, The fluid acting on the load device Characterized in that it is configured to control the flow rate.

[Action]

The first and second rotation driving bodies are independently driven to rotate according to the electric signal. The first rotary valve member is coupled to the first rotary driver and is rotatably inserted within the valve body. Further, the second rotary valve member is coupled to the second rotary drive member and is rotatably inserted in the first rotary valve member. Since the first and second rotary valve members rotate independently according to the rotation of the first and second rotary drive bodies, the valve opening degrees between the supply port and the return port and the load port are the same. It is set according to the relative rotational position angle,
This also controls the flow rate of the fluid acting on the load device.

The relative rotational position angle of the first and second rotary valve members can be appropriately controlled by adjusting the rotational angles of the first and second rotary drive bodies, and such control is found in flapper valves. Such on / off switching control is not performed.
Therefore, the valve opening can be adjusted extremely smoothly and quickly, and the responsiveness can be improved.

〔Example〕

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

FIG. 1 is a vertical sectional view of a rotary servo valve according to a first embodiment of the present invention. The first and second motors M1 and M1 correspond to a rotary drive body that is rotationally driven by an electric signal.
It is M2. The motors M1 and M2 may be either analog type motors driven by AC or DC electric analog signals or digital type motors such as pulse motors, and are not limited to general motors but rotary solenoids. Such a rotary driving body may be used. First
The first rotary valve member 1 is connected to the rotary shaft of the motor M1, and the second rotary valve member 2 is connected to the rotary shaft of the second motor M2.
Are connected. Both rotary valve members 1 and 2 have a cylindrical shape, and the member 1 is nested inside the member 2 and is rotatably housed in the valve body 3. The valve body 3 includes a refueling port S, a return port R, and load ports C1, C2, C.
3 and C4.

A first chamber 4 and a 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 a fuel supply port S of the valve body 3 to serve as a fuel supply chamber. There is. Second chamber 5
Has one end opened to communicate with the inner chamber of the rotary valve member 2 on the outer side, and further always communicates with the return port R of the valve body 3 to form a return chamber. At the location corresponding to the refueling port S
A cross section taken along the line II-II is shown in FIG. 2, and a ring-shaped flow path 6 formed of a ring-shaped groove space surrounding the periphery of the rotary valve member 1 is formed on the valve main body 3 side. S
It leads to. On the wall surface of the rotary valve member 1, an appropriate number (two in the figure) of openings 1s are provided in a position corresponding to the ring-shaped flow path 6 in a predetermined angle range, and the openings 1s communicate with the fuel supply chamber 4. There is. Therefore, no matter how the rotary valve member 1 rotates, the oil supply port s and the oil supply chamber 4 are always communicated with each other through the ring-shaped flow path 6 and the opening 1s. A cross section taken along the line III-III of the portion corresponding to the return port R is as shown in FIG. 3, and similarly to the above, the ring-shaped flow path 7 communicating with the return port R is formed in the valve main body 3, and the second rotary valve is provided. The member 2 is provided with an opening 2r, and the return port R and the return chamber 5 are always in communication with each other.

A, B, C at locations corresponding to the load ports C1 to C4,
Cross-sectional views taken along the line D are as shown in FIGS. 4 and 5. FIG. 4 is a sectional view taken along the line A of the portion corresponding to the load port C1, but the sectional view taken along the line D of the portion corresponding to C4 has the same shape.
Although FIG. 5 is a sectional view taken along the line B of the portion corresponding to the load port C2, the sectional view taken along the line C of the portion corresponding to C3 has the same shape. The valve body 3 has ring-shaped flow paths 8, 9, 10, 1 formed of ring-shaped groove spaces surrounding the outer rotary valve member 2.
1 is formed corresponding to each load port C1 to C4, and this is connected to each corresponding load port C1 to C4. The wall surfaces of the rotary valve members 1 and 2 are provided with openings 1a at positions corresponding to the ring-shaped flow paths 8 to 11 in a predetermined angle range.
1b, 1c, 1d, 2a, 2b, 2c, 2d (2a to 2
(d is not shown in FIG. 1 since it is out of the longitudinal section), and the opening 1 of the inner valve member 1 is provided.
The a and 1b communicate with the fuel supply chamber 4, and the openings 1c and 1d communicate with the return chamber 5. The openings 2a to 2d of the outer valve member 2 face the ring-shaped flow paths 8 to 11, respectively, and the openings 2a to 2d communicate with the load ports C1 to C4 regardless of the rotational position of the valve member 2. It is like this. Therefore, the openings 1a to 1d of the first valve member 1 and the openings 2a of the second valve member 2 are formed.
~ 2d depending on the degree of overlap with the refueling chamber 4 and the return chamber 5
And the valve opening between the load ports C1 to C4 are determined.

Specifically, the first load port C1 corresponding to the fuel supply chamber 4 and the third load port C3 corresponding to the return chamber 5 communicate with each other and are connected to the first port of the load device (for example, the hydraulic cylinder 12). It Further, the second load port C2 corresponding to the fuel supply chamber 4 and the fourth load port C4 corresponding to the return chamber 5 communicate with each other, and are 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 and 1d corresponding to the first and fourth load ports C1 and C4 are provided at the same angular positions as shown in FIG. The second and third openings 1b and 1c corresponding to the second and third load ports C2 and C3 are also provided at the same angular position as shown in FIG.
Further, also in the second rotary valve member 2, the first and fourth openings 2 corresponding to the first and fourth load ports C1 and C4 are provided.
a and 2d are provided at the same angular position as each other as shown in FIG. 4, and second and third openings 2b and 2c corresponding to the second and third load ports C2 and C3 are also shown in FIG. As described above, they are provided at the same angular position. Although the ports S, R, and C1 to C4 are shown at the same angular position in the drawing, it goes without saying that the ports are not limited to this.

The group of first and fourth openings 1a, 2a, 1d, 2d corresponds to the first valve position and the second and third openings 1
The group b, 2b, 1c, 2c corresponds to the second valve position. That is, when the first and fourth openings 1a, 2a, 1d, 2d overlap between the rotary valve members 1, 2, the second and third openings 1b, 2b, 1c, 2c do not overlap ( At this time, a flow path is formed in the direction of the solid line arrow in FIG. 1), and the second and third openings 1b, 2 are formed.
When b, 1c and 2c overlap, the first and fourth openings 1
In order to prevent a, 2a, 1d, and 2d from overlapping (at this time, a flow path is formed in the direction of the broken line arrow in FIG. 1), the angular deviation of the corresponding openings between the rotary valve members is the first.
And a fourth opening group 1a, 2a, 1d, 2d and a second
And the third opening groups 1b, 2b, 1c, 2c are arranged so as to be displaced from each other by a predetermined angle. 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 2a and 2d of the outer rotary valve member 2 are provided. Opening 2
b and 2c are provided with a shift of approximately 180 degrees (see FIGS. 4 and 5). Therefore, the angular deviation (corresponding to the degree of overlapping of the openings) between the valve members 1 and 2 with respect to the first and fourth opening groups 1a, 2a, 1d and 2d is determined by the second and third opening groups 1b and 2b. , 1c, 2c, the angular deviation between the valve members 1 and 2 (corresponding to the overlapping degree of the openings) is shifted by about 180 degrees. As a result, when one opening group 1a, 2a, 1d, 2d is open, the other is always closed and flows out from the load port C1 to the load cylinder 12 and into the load port C4 (actual arrow in FIG. 1). Is formed, and the other opening group 1b, 2
When b, 1c and 2c are in communication, one of them is always closed, and a flow path (broken line arrow in FIG. 1) that flows out from the load port C2 to the load cylinder 12 and flows into the load port C3 is formed.

The angular ranges in which the openings 1a to 1d and 2a to 2d are open are approximately 90 degrees. As a result, the overlapping of one opening group is controlled within the range in which one of the rotary valve members 1 and 2 rotates 180 degrees relative to the other (while the other opening group remains closed), the remaining 18
The 0 degree relative rotation range controls the overlap of the other opening group (while one opening group remains closed). This point is shown in FIGS. 6A to 6D, and the relative rotation angle of the first rotary valve member 1 with respect to the second rotary valve member 2 is 0 degree (a). 360 degrees),
90 degrees in (b), 180 degrees in (c), 2 in (d)
It is 70 degrees. That is, as shown in (a), (b), and (c), the opening groups 1a, 2a, 1d, and 2d communicate in the range of the relative rotation angle of 0 to 180 degrees, and (c),
As shown in (d) and (a), the aperture groups 1b, 2b, 1c, and 2c communicate in the range of 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 opening degree of the valve is determined by the relative rotational positional relationship between the rotary valve members 1 and 2, that is, the relative rotational angle. For example, when the relative positional relationship between the two is in the range of FIG. 6 (a) to (b), one valve opening (overlapping of the openings 1a, 2a and 1d, 2d) can be controlled from 0% to 100%, In the range from (b) to (c), it is possible to control from 100% to 0%, and in the range from (c) to (d), the other valve opening (opening 1
b, 2b and 1c, 2c overlap) 0% to 100%
Controllable up to 10 in the range from (d) to (a)
It can be controlled from 0% to 0%.

The rotation control of the rotary valve members 1 and 2 may be any control as long as the desired valve opening degree can be finally achieved. For example, one may be stationary and the other may only be rotated, or forward and reverse rotation may be arbitrarily performed. However, in order to realize high response performance, it is most preferable to control both rotary valve members 1 and 2 so as to always rotate in the same direction. For example, if both members 1 and 2 are rotated counterclockwise in FIG. 6, when the valve opening is increased in the range of (a) to (b), the inner valve member 1 is rotated to open the valve. When the degree is reduced, the outer valve member 2 is rotated, and from (b) to (c)
In this range, the valve opening degree decreases when the inner valve member 1 is rotated, and the valve opening degree increases when the outer valve member 2 is rotated. This is shown in an enlarged development view as shown in FIG. 7, and when the valve opening is increased from the state of (a), the valve member 1 is rotated by an appropriate amount in one direction so that the relationship between the openings 1a and 2a becomes (b). ), When it is desired to reduce the valve opening from this state, the valve member 2 is rotated in one direction by an appropriate amount so that the relationship between the openings 1a and 2a is as shown in (c). In this way, by always rotating the rotary valve members 1 and 2 in one direction, the desired valve opening is followed (fine adjustment of valve opening).
It can be performed. Therefore, mechanical fine reversal movement is not required at all when finely adjusting the valve opening and closing, which is always required in servo valve control, and the valve opening and closing control can always be achieved by one-way movement. Performance is dramatically increased. Of course, it is not absolutely necessary for the rotary valve members 1 and 2 to rotate in the reverse direction. For example, when switching the valve position, the rotation valve members 1 and 2 may be rotated in the opposite direction.

Rotary valve members 1 and 2, valve body 3, ring-shaped flow paths 6 to 11,
The structures and shapes of the openings 1a to 1d, 1s, 2a to 2d, 2r are not limited to those shown in the drawings, and various modifications are possible. Further, the drive is not limited to hydraulic drive, and may be pneumatic or other fluid pressure drive.

Of course, similar to a normal servo valve, a means for returning the valve to the neutral position when it is off is provided. This means comprises, for example, a spring 13 having one end fixed to the valve member 1 and the other end fixed 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. The first rotary valve member 14 coupled to the first motor M1 is fitted to the second rotary valve member 15 engaged with the second motor M2, and these are inserted into the valve body 16. . Inside the valve body 16,
Ring-shaped flow paths SR, RR, C composed of ring-shaped groove spaces
1R and C2R are provided corresponding to the respective ports S, R, C1 and C2. The side surface of the inner rotary valve member 14 has 90
Four grooves 14a, 14b, 14c, 14d are provided at intervals of degrees. The outer rotary valve member 15 is provided with a pair of passages SP, RP, C1P, C2P penetrating the wall surface thereof. 18 per pair (eg C1P)
It consists of two passages separated by 0 degrees, and each pair is 45 in sequence of C1P, SP, C2P, RP, as is clear from FIG.
They are arranged at different intervals. Each passage C1P, SP, C2
The inner ports of P and RP are the inner rotary valve members 14a to 14d.
To the positions corresponding to the ring-shaped flow paths C1R, SR, C2R and RR corresponding to the respective openings.

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 the passages C1P, C2P communicating with the load ports C1, C2. The lateral widths of the grooves 14a to 14d of the inner rotary valve member 14 are set so as not to reach the mouths of the three passages at the same time. In the state of 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 relatively rotates counterclockwise from this state, the passages SP and C1P communicate with each other through the grooves 14a and 14c, and the passage S through the grooves 14b and 14d.
P and C2P can communicate. As a result, the load port C1 comes out and the load port C2 comes in. When the rotary valve member 14 relatively rotates counterclockwise by 45 degrees from the position shown in the figure, the valve is closed. When it is further rotated counterclockwise from here, the passages SP and C2P communicate with each other through the grooves 14a and 14c, and the groove 1
The passage RP and C1P come to communicate with each other via 4b and 14d. This causes the load port C2 to exit and enter C1. In this way, the switching position of the servo valve is set and the valve opening is adjusted according to the relative rotation angle of both rotary valve members 14 and 15. As in the first embodiment described above, if the rotation directions of the motors M1 and M2 are constant,
The response performance can be improved.

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

In FIG. 10, one end of the spool 18 is connected to the motor M1 via a screw connection 19 and the other end is connected to the motor M2 via a spline connection 20. The rotation of the motor M1 in a predetermined direction causes the spool 18 to move in a predetermined direction (for example, an arrow x
Direction), and the spool 18 is directly moved in the opposite direction to the above by rotation of the motor M2 in a predetermined direction. In this case as well, the spool 18 can be moved left and right while always rotating the motors M1 and M2 in only one predetermined direction, thereby performing valve switching and valve opening adjustment. Therefore, high response and fine adjustment are possible. 11 is almost the same as FIG. 10, except that a gear coupling 21 is used instead of the spline coupling 20.

In the embodiment shown in FIGS. 8 to 11, although illustration is omitted, a spring for returning to the neutral position is 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 port of the servo valve 22, and its position and speed are detected by a detector 24. And provided to the deviation calculator 25. The program setter 26 sets a numerical control program and is supplied with target data corresponding to the numerical control program set under the control of the microcomputer 27. 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 M1 and M2 of the servo valve 22 in accordance with the deviation data, and the servo valve 2
2 control the operation.

As an example, the pulse supply circuit 28 outputs the up pulse first when the fluid pressure actuator 23 should be moved in the forward direction and outputs the down pulse first when it should be moved in the reverse direction according to the sign of the deviation data. . For example, the up pulse is always supplied to the first motor M1, and accordingly, the motor M1 is always rotated in only one predetermined direction. Further, the down pulse is constantly supplied to the second motor M2, and accordingly, the motor M2 is always rotated only in a predetermined one direction. The rotation of the two motors M1 and M2 in a predetermined direction has the effect of increasing or decreasing the relative rotation angle of the two motors, as described above.

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 to set the relative rotation angle appropriately. When stopping the movement of the actuator 23, the same number of down pulses are given to the motor M2, the relative rotation angle is set to 0, and the valve is closed.

When moving the fluid pressure actuator 23 in the reverse direction, a proper number of down pulses are given to the motor M2, and the relative rotation angle is appropriately set. When stopping the movement of the actuator 23, the same number of up-pulses are applied to the motor M1, the relative rotation angle is set to 0, and the valve is closed.

Regardless of whether the actuator 23 is moved forward or backward, or how the increase or decrease of the valve opening is controlled, the motor M
The rotation directions of 1 and M2 do not change and are always constant directions.
Therefore, since there is no reverse movement of the motors M1 and M2, high responsiveness can be ensured.

The minute flow rate can be controlled by controlling the relative rotation angles of the motors M1 and M2 in a minute time. That is, as shown in FIG. 13, the phase of the pulse applied to the motors M1 and M2 is set to a minute time t of less than the pulse width t _2.
By controlling with ₁ , the minute current is controlled. In this case, the valve opening degree corresponding to the relative rotation angle corresponding to one pulse driving of the motor M1 is set only for the short time t _1,
The flow rate is an integral value of the valve opening degree only for a minute time t ₁ .
By enabling such a minute flow rate control, the control accuracy of the load actuator 23 can be increased.

[Effects of the Invention] As described above, according to the present invention, it is possible to improve the response performance and also to excel in minute flow rate control, and to improve control accuracy. Exerts the excellent effect of.

[Brief description of drawings]

1 is a longitudinal sectional view showing an embodiment of the rotary servo valve according to the present invention, FIG. 2 is a sectional view taken along the line II-II in FIG. 1, and FIG. 3 is a sectional view taken along the line III-III in FIG. 4 and 5 are cross-sectional views taken along the line A in FIG. 1, showing the same shape as the cross-section taken along the line D,
FIG. 5 is a cross-sectional view taken along the line B of FIG. 1, showing the same shape as the cross-section taken along the line C, and FIG. 6 is a cross-sectional view of the first embodiment.
And a cross-sectional view illustrating the relative rotational positional relationship between the second rotary valve member, FIG. 7 is an expanded view showing an example of changes in the overlapping of the openings of both rotary valve members in an enlarged manner, and FIG. 8 is the present invention. FIG. 9 is a vertical sectional view showing another embodiment of the rotary servo valve of FIG.
FIG. 10 is a sectional view taken along the line IX-IX of FIG. 10, and FIGS. 10 and 11 are longitudinal sectional views showing still another embodiment of the servo valve according to the present invention.
FIG. 12 is a schematic block diagram showing an embodiment of the control system of the rotary servo valve according to the present invention, and FIG. 13 is a timing chart showing an example at the time of minute flow rate control. M1, M2 ... First and second motors, 1, 2, 14, 1
5 ... 1st and 2nd rotary valve member, 1a-1d, 2a-2
d ... Opening corresponding to each load port, 1e ... Partition wall, 3, 1
6, 17 ... Valve main body, 4 ... Oil supply chamber, 5 ... Return chamber, S ... Fluid supply port, R ... Return port, C1-C4 ... Load port, 6-11 ... Ring-shaped channel consisting of ring-shaped groove space, 12 ... Load cylinder, 18 ... Spool, 19 ... Screw connection, 20 ... Spline connection, 21 ... Gear connection.

Claims (1)

[Claims] 1. A first and a second rotary drive body, which are driven to rotate by an electric signal, a supply port for supplying a fluid to the inside, a return port for discharging the fluid to the outside, and a load device with the fluid. A valve body having a load port for allowing rotation, a first rotary valve member rotatably inserted into the valve body, and rotating in response to rotation of the first rotary drive body; and a first rotary valve member. A second rotary valve member that is rotatably inserted therein and that rotates in response to rotation of the second rotary drive body, and controls the first and second rotary drive bodies by independent electrical signals. By doing so, the valve opening degree between the supply port and the return port and the load port corresponding to the mutual rotational position angle of the first and second rotary valve members is adjusted, and acts on the load device. Control the flow rate of the fluid Uni configured rotary servo valve.