JP2003021110A - Servo valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To actuate a plurality of servo valves synchronously. SOLUTION: A valve part 18 is divided into one valve half part 19 and the other valve half part 25 to be one set of the valve, and two sets of the valve parts 18, 18 are provided in parallel. Synchronous plates 10, 11 are coupled to a supporting shaft 6 of a torque motor part 2. A plunger 23 of one valve half part 19 is made to normally about on the synchronous plate 10, and a plunger 29 of the other valve half plunger 25 is made to normally abut on the synchronous plate 11. When the torque motor part 2 is actuated, the supporting shaft 6 is rotated integrally with an armature 4, and the synchronous plates 10, 11 and a flapper 14 rock following rotations of the supporting shaft 6. The distance between the flapper 14 and a nozzle 15 is changed, and a difference is caused between the back pressures of both nozzles 15, 15, so that pistons 22, 28 are moved. The synchronous plates 10, 11 regularly about one the plungers 23, 29 of the valve half portions 19, 25, so that both valve portions 18, 18 are actuated while perfectly synchronizing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a servo valve used in aircrafts, ships, vehicles, general industrial machines, etc.
In particular, the present invention relates to a servo valve effective for controlling the flow rate of hydraulic oil of an actuator.

[0002]

2. Description of the Related Art There are various types of servo valves used for controlling the flow rate of hydraulic oil in actuators of aircraft, ships, vehicles, general industrial machines, etc. For example, a nozzle flapper type servo as shown in FIG. Valves are commonly known.

That is, the servo valve 31 includes a torque motor section 32 for converting an input current into a displacement of a flapper 38 via an armature 34, and a pair of nozzles provided so as to face the displacement of the flapper 38 with the flapper 38 interposed therebetween. 39 and 39, a hydraulic pressure amplification unit 36 that converts the pressure difference of hydraulic pressure, a valve unit 42 that controls the flow rate of hydraulic oil by converting the pressure difference of the hydraulic pressure amplification unit 36 into the displacement of the piston 45,
And a feedback unit 52 for feeding back the displacement of the piston 45 to the flapper 38.

When a current is input to the torque motor unit 32 of the servo valve 31 having the above-described structure, a torque corresponding to the input current is generated in the torque motor unit 32, the armature 34 rotates, and the armature 34 rotates. Following this, the flapper 38 oscillates and is displaced in the direction of the nozzle 39, and a difference in back pressure between the nozzles 39, 39 is produced according to the displacement of the flapper 38. Here, since the back pressure of both nozzles 39, 39 is the pressure acting on both end surfaces of the piston 45,
The piston 45 moves and displaces according to the back pressure difference between the two nozzles 39, 39. When the piston 45 is displaced, the feedback unit 5 follows the displacement of the piston 45.
The second feedback wire 53 bends, and the feedback wire 53 returns from the bent state to the original state, whereby the flapper 38 is pushed back to the center, and both nozzles 39,
The back pressure difference of 39 becomes 0, the piston 45 stops at that position, and the flow rate of the hydraulic oil via the valve portion 42 is determined.

[0005]

However, in the servo valve 31 having the above-mentioned structure, a plurality of servo valves 3 are used when controlling the flow rate of a large amount of hydraulic oil.
1 and 31 may be used in parallel, but the operation becomes unstable due to the difference in the characteristics of the individual servo valves 31, and the plurality of servo valves 31, 31 cannot be perfectly synchronized, The desired flow rate control cannot be performed. In order to solve such a problem, a plurality of servo valves 31, 31 are mechanically linked (not shown).
Although a method of connecting and synchronizing by is proposed by,
Since the mechanical link mechanism has a complicated structure, the structure of the servo valve as a whole becomes complicated and the price becomes high.

The present invention has solved the above-mentioned problems, and when a plurality of servo valves are used in parallel, a plurality of servo valves can be used without being affected by the difference in characteristics of the individual servo valves. Servo valves can be perfectly synchronized and the overall structure can be simplified,
Moreover, it is an object of the present invention to provide a servo valve whose price can be kept low.

[0007]

In order to solve the above problems, the present invention provides a body with a torque motor unit for converting an input current into a displacement of a flapper via an armature and a flapper for displacement of the flapper. A hydraulic pressure amplifying section for converting the hydraulic pressure into a pressure difference via a pair of nozzles provided opposite to each other, and a valve section for converting the pressure difference in the hydraulic amplifying section into a displacement of a piston to control the flow rate of hydraulic oil. A servo valve provided with a feedback portion for feeding back the displacement of the piston to the flapper, the valve portion being connected to one valve half portion connected to the one nozzle and the other nozzle The other valve half is divided into two sets to form one set, and at least two sets are provided in parallel, and one valve half and the other valve half of each set are set to the armor. It is obtained by employing the means arranged to synchronize by contact at all times in the synchronization plate displaced Interview A integrally. In this case, for example, a support shaft is rotatably attached to the body via a bearing, one end of the support shaft is integrally connected to the armature, and the other end is integrally connected to the body, and The synchronizing plate and the flapper may be connected to the support shaft so as to follow the rotation of the support shaft and swing. Further, the support shaft may be composed of a torsion spring, and may also be used as the feedback unit.

According to the present invention, by adopting the above means, when a current is input to the torque motor unit, a torque corresponding to the input current is generated to displace the armature, and the flapper is integrated with the displacement of the armature. And the synchronizing plate is displaced, the distance between the flapper and both nozzles changes, and the back pressure of both nozzles is different. Due to this back pressure difference, the piston of one valve half of each set or the other valve half The piston moves and is displaced, and the flow rate of hydraulic oil is controlled. In this case, one valve half portion and the other valve half portion of each set are always in contact with the synchronizing plate, so that they operate in synchronization. Further, when the support shaft is composed of a torsion spring and also serves as the feedback part, when the support shaft rotates integrally with the armature, the support shaft is twisted, and the support shaft is returned from the twisted state to the original state. By returning, the flapper is pushed back to the neutral position, and the displacement of the piston in each valve half is fed back to the flapper.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention shown in the drawings will be described below. FIG. 1 shows an embodiment of a servo valve according to the present invention. The servo valve 1 includes a torque motor unit 2, a hydraulic pressure amplifying unit 12, a valve unit 18, a feedback unit 31 provided on a body 9. It is equipped with

The torque motor unit 2 is for converting an input current into a displacement of the flapper 14, and is rotatably provided between the permanent magnet 3 having a magnetic pole facing the tip and both magnetic poles of three permanent magnets. Armature 4 and Armature 4
5, a coil 5 wound around the armature 4, a support shaft 6 having one end connected to the armature 4 and the other end fixed to the body 9 side, and a radial bearing rotatably supporting the support shaft 6 on the body 9. Etc., and a seal member 8 such as an O-ring for sealing between the support shaft 6 and the body 9.

The hydraulic pressure amplification unit 12 converts the displacement of the armature 4 of the torque motor unit 2 into a hydraulic pressure difference via the flapper 14, and is arranged so that the support shaft 6 of the torque motor unit 2 is orthogonal to the axis. The nozzle flapper mechanism 13 is composed of a flapper 14 connected to the support shaft 6 and swinging following the support shaft 6, and a pair of nozzles 15 and 15 provided to face each other with the flapper 14 interposed therebetween.

The support shaft 6 of the torque motor unit 2 is attached to the support shaft 6.
The two synchronizing plates 10 and 11 are connected in a cross shape so as to be orthogonal to the axis line of, and are adapted to swing following the rotation of the support shaft 6. One valve half portion 19 of a valve portion 18 described later is always in contact with one synchronizing plate 10, and the other valve half portion 25 is always in contact with the other synchronizing plate 11.

The main filter 1 is provided inside each nozzle 15.
The hydraulic oil is introduced through the nozzle 7 and the orifice 16. One of the nozzles 15 has a valve portion 18 which will be described later.
One of the valve half portions 19 is communicated with the rear end portion of the cylinder chamber 21, and the other nozzle 15 is communicated with the rear end portion of the cylinder chamber 27 of the other valve half portion 25.
Therefore, the back pressure acting on each nozzle 15 is guided to the rear end portion of the cylinder chamber 21, 27 of each valve half portion 19, 25, that is, the rear end surface of each piston 22, 28.

When the input current to the torque motor unit 2 is 0, the flapper 14 is located equidistant from both nozzles 15 and 15, and the same amount and pressure of hydraulic oil is supplied from both nozzles 15 and 15. The jetting and the back pressure of both nozzles 15, 15 are in a balanced state. On the other hand, when current is input to the torque motor unit 2 and the armature 4 rotates, the support shaft 6 rotates integrally with the armature 4, and the flapper 14 and the synchronizing plates 10 and 11 oscillate following the rotation of the support shaft 6. The flapper 14 is moved and displaced in the direction of the nozzle 15. When the flapper 14 is displaced in the direction of the nozzle 15, the distance between the flapper 14 and the nozzles 15 and 15 changes, and the balance of the back pressure of the nozzles 15 and 15 is disturbed.
The back pressure of No. 5 changes, and both nozzles 15, 15 make piston 2
2, the pressure difference of the hydraulic oil introduced to the rear end surface,
The pistons 22 and 28 move and are displaced according to the pressure difference.

The valve portion 18 is composed of one valve half portion 19 and the other valve half portion 25.
Two valve halves 19 and 25 are set as one set, and two sets are provided in parallel on the body 9.

A cylinder chamber 21 is provided inside one valve half portion 19, and a supply port (not shown), a return port (not shown) and a control port (not shown) which communicate with the cylinder chamber 21. Body 20 provided with
The piston 22 movably provided in the cylinder chamber 21 of the body 20, the rear end surface of the cylinder chamber 21, and the piston 2
2 includes a spring 24 provided between the rear end surface and the rear end surface of the piston 22, and a plunger 23 integrally provided at the tip of the piston 22 and protruding from the cylinder chamber 21.

The other valve half 25 has a cylinder chamber 27 provided therein, and a supply port (not shown), a return port (not shown) and a control port (not shown) which communicate with the cylinder chamber 27. A body 26 provided with
The piston 28 movably provided in the cylinder chamber 27 of the body 26, the rear end surface of the cylinder chamber 27, and the piston 2
8 and a rear end surface of the piston 28, and a plunger 29 integrally provided at the tip of the piston 28 and protruding from the cylinder chamber 27.

The back pressure of one nozzle 15 of the hydraulic amplifier 12 is introduced to the rear end of the cylinder chamber 21 of one valve half 19 of each valve 18, and the cylinder chamber 27 of the other valve half 25 is introduced. The back pressure of the other nozzle 15 of the hydraulic amplification unit 12 is introduced to the rear end portion, and the piston 22 of one valve half portion 19 or the other valve half portion of the other valve half portion 19 is responsive to the back pressure difference between the two nozzles 15, 15. 25 of the piston 28 is the cylinder chamber 21, 27
Move inside and displace. Each port is opened / closed or the degree of opening / closing of each port is adjusted according to the displacement of the pistons 22 and 28, and the flow rate of the hydraulic oil via each port is controlled.

The feedback portion 31 is also used as the support shaft 6 made of a torsion spring, and when the support shaft 6 rotates integrally with the rotation of the armature 4, the support shaft 6 is twisted and is supported. When the shaft 6 returns from the twisted state to the original state, the flapper 14 is pushed back to the neutral position, the pistons 22 and 28 are stopped at that position, and the flow rate of the hydraulic oil through the pistons 22 and 28 is determined. . That is, the support shaft 6 has a function of feeding back the displacement of the pistons 22 and 28 to the flapper 14.

When a current is input to the torque motor unit 2 of the servo valve 1 constructed as described above, a torque proportional to the input current is generated in the torque motor unit 2, and the armature 4 rotates according to the torque. To do.

When the armature 4 rotates, the support shaft 6 rotates together with the rotation of the armature 4, and the support shaft 6 is twisted. Following the rotation of the support shaft 6, the flapper 14 and the synchronizing plate 10, 11 swings, the flapper 14 is displaced in the direction of the nozzle 15, and the distance between the flapper 14 and the nozzles 15 and 15 which are located equidistant from the nozzles 15 and 15 is changed to maintain the balance. Both nozzles 1
There is a difference in back pressure between 5 and 15. This back pressure is the piston 2
Since the pressure acts on the rear end surfaces of the pistons 2 and 28, the pistons 22 and 28 start to move to the lower pressure side. in this case,
Plunger 2 of one valve half 19 of each valve portion 18
3, the one synchronizing plate 10 is always in contact with the other valve half 25 and the plunger 29 of the other valve half 25 is always in contact with the other synchronizing plate 11, so that one valve half 19 of both valve parts 18, 18 is in contact. And the other valve half 25 will operate synchronously.

When the support shaft 6 returns from the twisted state to the original state, the flapper 14 is pushed back to the neutral position, the back pressure difference between the two nozzles 15 and 15 becomes zero, and the pistons 22 and 28 move. After stopping at the position, the flow rate of the hydraulic oil through the valve portion 18 is determined.

In the servo valve 1 according to this embodiment configured as described above, the synchronizing plate 1 provided on the support shaft 6 is provided.
Since the valve half portions 19 of both valve portions 18 and 18 and the other valve half portion 25 of both valve portions 18 and 18 can be operated in synchronism with 0 and 11, there is a difference in characteristics between the individual valve half portions 19 and 25. However, the operation does not become unstable, and both valve parts 18 and 18 are completely synchronized within the error range of the control flow rate. Therefore, both valve parts 1
When 8 and 18 are connected to an actuator (not shown), they can be operated mechanically in perfect synchronization without the need for a mechanical link mechanism. Further, when the polarities of both valve parts 18 and 18 are changed and connected to the respective actuators, the phase of the speed is completely 1
Since it can be shifted by 80 °, it is effective for the purpose of converting reciprocating motion into rotary motion or the like.

[0024]

According to the present invention, the valve part is divided into two parts, one valve half part connected to one nozzle and the other valve half part connected to the other nozzle to form one set. , At least two sets of these are provided in parallel, and one valve half of each set and the other valve half are constantly brought into contact with the synchronizing plate that is integrally displaced with the armature, so that the characteristics of each valve half can be improved. Even if there is a difference, the operation does not become unstable, and the plurality of valve parts can be operated in perfect synchronization. That is, even when a plurality of valve parts are connected to an actuator, for example, the valve parts can be mechanically operated in perfect synchronization. Therefore,
A complicated and expensive mechanical link mechanism is not required, the structure of the servo valve as a whole can be simplified, and the cost can be reduced. Furthermore, when changing the polarity of multiple valve parts and connecting to each actuator,
Since it is easy to shift the velocity phase by 180 °,
It is effective for the purpose of converting reciprocating motion into rotary motion. Further, since the support shaft is rotatably attached to the body through the bearing and the support shaft and the body are sealed by the seal member, a commercially available inexpensive radial bearing or the like can be used for the bearing, A commercially available inexpensive O-ring or the like can be used for the seal member. Therefore, the price as a whole can be kept low and an inexpensive servo valve can be provided. In addition, since the support shaft is composed of a torsion spring and is also used as the feedback part, a feedback part for feeding back the displacement of the piston to the flapper can be configured by the support shaft composed of an inexpensive torsion spring, so that also as a whole. The price can be kept low.

[Brief description of drawings]

FIG. 1 is a schematic view showing an embodiment of a servo valve according to the present invention.

FIG. 2 is a schematic view showing an example of a conventional servo valve.

[Explanation of symbols]

1 ... Servo valve 2 ... Torque motor section 3 ... Permanent magnet 4 ... Armature 5 ... coil 6 ... Support shaft 7 ... Bearing 8 ... Seal member 9 ... Body 10, 11 ... Synchronous plate 12 ... Hydraulic pressure amplifier 13 ... Nozzle flapper mechanism 14 ... Flapper 15 ... Nozzle 16 ... Orifice 18 ... Valve part 19 ... One valve half 20, 26 ... Body 21, 27 ... Cylinder chamber 22, 28 ... Piston 23, 29 ... Plunger 24, 30 ... Spring 25 ... Half of the other valve 31 ... Feedback section

Claims (3)

[Claims] 1. A hydraulic pressure difference between a torque motor unit for converting an input current into a displacement of a flapper through an armature, and a pair of nozzles provided to face the displacement of the flapper with the flapper sandwiched in the body. And a valve unit for converting the pressure difference of the hydraulic pressure amplification unit into a displacement of the piston to control the flow rate of the working oil, and a feedback unit for feeding back the displacement of the piston to the flapper. In the servo valve, the valve part is divided into two parts, one valve half part connected to the one nozzle and the other valve half part connected to the other nozzle to form one set, At least two sets of these are provided in parallel, and one valve half part and the other valve half part of each set are always brought into contact with a synchronizing plate that is integrally displaced with the armature to synchronize them. Servovalve, characterized by being configured so. 2. A support shaft is rotatably attached to the body via a bearing, one end of the support shaft is integrally connected to the armature, and the other end is integrally connected to the body, and 2. The servo valve according to claim 1, wherein the synchronization plate and the flapper are connected to the support shaft so as to follow the rotation of the support shaft and swing. 3. The servo valve according to claim 2, wherein the support shaft is composed of a torsion spring and is also used as the feedback portion.