JP3264675B2 - 3 position switching valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a switching valve capable of switching a spool between three positions by fluid pressure.

[0002]

2. Description of the Related Art Generally, in an aircraft, in order to achieve a safe flight, a normal actuator is used to supply and discharge a working fluid from a fluid source to one actuator for an aircraft and operate the actuator as desired. A mode, a bypass mode in which one chamber and the other chamber of the actuator are directly communicated with each other to freely move the actuator, and a bypass mode in which one chamber of the actuator is communicated with the other chamber via a throttle to allow free movement of the actuator. There is a need to be able to switch between the three modes, the damping mode and the damping mode that suppresses the undesired movement.

[0003]

Conventionally, to achieve these three modes, a plurality of switching valves are interposed in the middle of the fluid circuit. However, all of such conventional switching valves are used. There was a problem that the structure was complicated and expensive.

An object of the present invention is to provide a three-position switching valve which can switch a fluid circuit in three positions while having a simple structure and low cost.

[0005]

Means for Solving the Problems] The above object, the Luque pacing that having a spool chamber therein, and a second position of the first position and the other stroke end of the housing is one stroke end to the spool chamber , A spring for urging the spool toward the second position, a plunger provided on the other side of the spool and movable in the axial direction, and a fluid on the other side of the spool. Pressure, and when the fluid pressure is high, the spool is moved to the first position against the spring, while when the fluid pressure is low, the spool is moved to the second position by the biasing force of the spring. One control passage allowing fluid flow to the other side of the plunger and the other control for moving the plunger toward the first position when the fluid pressure is high. When the control passage formed in the passage and the casing has a low pressure and the other control passage has a high pressure, the plunger moving toward the first position is stopped in the middle of the movement, so that the spring is attached. a stopper for stopping the spool is moving in force toward the second position at a third position between the first position and the second position, the 3 position switching valve having a a pair installation,
One control passage of one three-position switching valve is connected to the other control passage of the other three-position switching valve, and the other control passage of one three-position switching valve and one of the other three-position switching valve are connected. This can be achieved by connecting to a control passage.

[0006]

When the fluid pressure in one control passage is high and the fluid pressure in the other control passage is low,
Since the other side of the spool receives the high fluid pressure, the first end of one end of the spool is opposed to the spring.
Move to the position and stop. In this state, when the three-position switching valve of the present invention is applied to an aircraft fluid circuit,
This is the time when the fluid circuit is in the normal mode and the working fluid is supplied / discharged from the fluid source to the actuator through the switching valve without any trouble. The actuator is operated as desired by the pilot.

Next, when the fluid pressure in one and the other control passages becomes low from the above state, the biasing force of the spring against the spool overcomes the fluid force, so that the spool moves toward the second position. To switch to the second position, which is the other stroke end.
In this state, when the fluid circuit breaks down and enters the damping mode, one of the chambers of the actuator and the other chamber are communicated via the throttle through the switching valve of the present invention, and the free movement of the actuator is suppressed. Have been.

Next, when the fluid pressure in one control passage becomes low and the fluid pressure in the other control passage becomes high, the plunger receives the high fluid pressure of the other control passage on the other side and moves to the first position. Move towards.
The middle plunger this movement is to abut the stopper over, the plunger is stopped in the position. At this time, the spool is moved toward the second position by the spring, but the movement is stopped by contacting the stopped plunger halfway, and the third position between the first position and the second position is stopped.
Switch to position. This state is when the fluid circuit is in the bypass mode, and one chamber and the other chamber of the actuator are directly communicated (bypassed), and the actuator is freely moved. As described above, the fluid circuit can be switched at three positions while having a simple and inexpensive structure in which the plunger is provided on the other side of the spool and the stopper that defines the movement limit of the plunger is provided .

Also, a pair of three-position switching valves as described above are provided.
And one control passage of one three-position switching valve
Connects to the other control passage of the other three-position switching valve
And the other control of one three-position switching valve
Control passage and one control passage of the other three-position switching valve
Is connected, the plurality of fluid circuits can be switched at three positions while simplifying the control passage.

[0010]

An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 11 denotes a control device for driving and controlling a rudder such as a rudder of an aircraft. The control device 11 includes two fluid circuits 12 and 13. The control device 11 has a control mechanism 14, and a control valve 16 (tandem servo valve) is built in a housing 15 of the control mechanism 14. In the housing 15, two supply passages 17, 18 through which high-pressure fluid discharged from pumps 25, 26 are supplied.
And discharge passages 19, 20 for discharging the low-pressure fluid to the tank 29, and two pairs of supply / discharge passages 21, 22, 23, 24
Are formed. The supply passage 17 and the discharge passage 1
9, the supply / discharge passages 21 and 22 constitute a part of one fluid circuit 12, and the supply passage 18, the discharge passage 20, and the supply / discharge passages 23 and 24 constitute a part of the other fluid circuit 13. The supply and discharge passages 21 and 22, the supply passage 17, and the discharge passage 19 are connected to the control valve.
The connection state is switched by 16 and the supply / discharge passages 23, 24
The connection state between the supply passage 18 and the discharge passage 20 is switched by the control valve 16. The position of the spool of the control valve 16 is detected by a position detector (not shown), and the detection signal is fed back to the command signal side. 31 and 32 are supply passages
High-pressure passages connected to 17, 18 respectively, and 33, 34 are tanks
An electromagnetic valve 35 is connected to the high-pressure passage 31 and the low-pressure passage 33, and an electromagnetic valve 36 is connected to the high-pressure passage 32 and the low-pressure passage 34. When the power is turned on, the solenoid valves 35 and 36 are connected to the high pressure passages 31 and 32.
The high-pressure fluid in the inside flows out to the control passages 37 and 38. When the power is turned off, the low-pressure passages 33 and 34 and the control passages 37 and 38 are connected.

Reference numeral 41 denotes a cylinder as a tandem actuator. This cylinder 41 has two cylinder chambers inside.
It has a cylinder case 44 in which 42 and 43 are formed. 45, 46
Are pistons movably housed in the cylinder chambers 42 and 43, respectively. These pistons 45 and 46 are provided on a single piston rod 47 in the axial direction. And
The head side of this cylinder 41 is connected to the fuselage of the aircraft,
The tip of the piston rod 47 is connected to a rudder such as the rudder. 48 and 49 are fluid passages connected to the cylinder chamber 42, 50 and 51 are fluid passages connected to the cylinder chamber 43, and these fluid passages 48 and 49 are a part of the one fluid circuit 12 and a fluid passage 50. , 51 constitute a part of the other fluid circuit 13. Reference numeral 52 denotes a position detector for detecting the position of the piston rod 47. A deviation signal between an output signal (feedback signal) of the position detector 52 and a command signal is used as an input signal to the force motor. , The cylinder 41 is servo-controlled.

Reference numerals 55 and 56 denote a pair of three-position switching valves provided between the control mechanism 14 and the cylinder 41. These switching valves 55 and 56 are shared with spool chambers 54 and 57 formed therein. It has a case 58, and cylindrical sleeves 53, 59 are housed and fixed in the spool chambers 54, 57, respectively. The case 58 and the sleeves 53 and 59 as a whole constitute a single common casing 60 that is continuous in the axial direction. 61, 62
Are passages formed in the casing 60 and connected to the supply / discharge passages 21 and 22, respectively, and 63 and 64 are passages formed in the casing 60 and connected to the supply / discharge passages 23 and 24, respectively. Further, 65, 66 are passages formed in the casing 60 and connected to the fluid passages 48, 49, respectively, and 67, 68 are also formed in the casing 60, and the fluid passages 50,
It is a passage connected to 51 respectively.

Reference numerals 70 and 71 denote spools housed in the spool chambers 54 and 57, respectively.
The first lands 72, 73, toward the outside (one side) in the axial direction
The second land 74, 75, the third land 76, 77, the fourth land 78,
79 are formed respectively. Also, each spool 70, 71
Flanges 80, 81 that can abut the axially outer ends (one ends) of the sleeves 53, 59 are formed at the axially outer ends (one ends) of the sleeves 53, 59. As a result, the spools 70 and 71 are
Inside the spool 57, a first position (normal mode position) of an outer stroke end where the axial outer ends (one ends) of the spools 70, 71 abut against the axial outer ends (one ends) of the spool chambers 54, 57, and a flange. It is possible to move in the axial direction between the second position (damping mode position) of the inner stroke end in which 80, 81 abuts the outer ends (one end) of the sleeves 53, 59 in the axial direction. Then, as shown in FIG.
When both are in the first position, the passages 61 and 65 are
62 and 66, 63 and 67, and 64 and 68 communicate with each other. Also,
When the spools 70 and 71 are both at the second position as shown in FIG. 2, the passages 61 and 63 and the passages 65 and 67 are in the second position.
Blocked by lands 74 and 75, and passages 62 and 64
The passages 65 and 66 are communicated with each other through a narrow throttle 82 (orifice) provided between the spool 70 and the sleeve 53, while being blocked by the fourth lands 78 and 79. The passage 68 communicates with a narrow throttle 83 (orifice) provided between the spool 71 and the sleeve 59. Springs 86 and 87 are interposed between the flanges 80 and 81 and the axially outer ends (one ends) of the spool chambers 54 and 57, respectively.
These springs 86 and 87 urge the spools 70 and 71, respectively, toward the inside (the other side) in the axial direction, that is, toward the second position.

Plungers 88, 89 movable in the axial direction are accommodated in spool chambers 54, 57 axially inside (the other side) of the spools 70, 71, and these plungers 88, 89 and the spool 70, A high-pressure or low-pressure (tank pressure, almost atmospheric pressure) fluid is introduced into one of the control passages 90 and 91 connected to the control passages 37 and 38, respectively, in the spool chambers 54 and 57 between the spool chambers 71 and 38. As a result, the guided fluid pressure acts on the inner side surfaces (other side surfaces) of the spools 70 and 71 in the axial direction. And the plunger 8
Spool chambers 54, 57 between 8, 89 and the spools 70, 71
When the fluid pressure guided to the
Since the fluid force acting on the other side of 0, 71 exceeds the biasing force of the springs 86, 87, both spools 70, 71
6 and 87 are moved to the first position, but from such a state, when one of the control passages 90 and 91 becomes low pressure, the fluid pressure guided to the spool chambers 54 and 57 becomes low pressure. Then, since the urging force of the springs 86 and 87 exceeds the fluid force, these spools 70 and 71
It moves to the second position by the urging forces of 86 and 87. 92, 93
Are the other control passages connected to the other ends of the spool chambers 54, 57, and these control passages 92, 93 control the fluid pressure in the control passages 92, 93 by the plungers 88, 89.
To the inner side (other side) in the axial direction. One control passage 90 of one switching valve 55 is connected to the other control passage 93 of the other switching valve 56, and the other control passage 92 of one switching valve 55 is connected to one of the other switching valves 56. Is connected to the control passage 91 of the vehicle. Further, flanges 96 and 97 are formed on the outer periphery of the plungers 88 and 89 at the inner end (the other end) in the axial direction. When the pressure in one control passage 90 becomes low and the pressure in the other control passage 92 becomes high, the plunger 88 of the one switching valve 55 moves toward the first position, and the flange 96 moves to the other side of the spool chamber 54. When it comes into contact with the step as a stopper provided at the end, here, the axial inner end surface (the other end surface) 94 of the sleeve 53, the movement stops halfway. At this time, the spool 86 is pressed toward the second position by the spring 86.
The 70 abuts on the plunger 88 stopped halfway and its movement is restricted, and stops at a third position (damping mode position) between the first position and the second position. When the pressure in one control passage 91 becomes low and the pressure in the other control passage 93 becomes high, the plunger 89 of the other switching valve 56 moves toward the first position, and the flange 97 moves to the other side of the spool chamber 57. A step as a stopper provided at the end,
Here, when the sleeve 59 abuts on the axial inner end face (the other end face) 95, the movement stops halfway. At this time, the spool 71 pressed toward the second position by the spring 87 abuts on the plunger 89 stopped halfway, and its movement is restricted, and the third position between the first position and the second position is restricted. (Damping mode position). Here, when the spool 70 is located at the third position, the passage 61 and the passage 65 are blocked by the second land 74, and the passage 62 and the passage 66
Is blocked by the fourth land 78, but the passage 65 and the passage
66 communicates through an annular groove between the second land 74 and the third land 76 so that fluid can freely flow between the cylinder chamber 42 on the head side and the cylinder chamber 42 on the rod side.
Is located at the third position, the passage 63 and the passage 67
The passage 64 and the passage 68 are blocked by the fourth land 79, and the passage 67 and the passage 68 communicate with each other through an annular groove between the second land 75 and the third land 77. The fluid freely flows between the cylinder chamber 43 on the head side and the cylinder chamber 43 on the rod side.

Next, the operation of the embodiment of the present invention will be described. Now, it is assumed that the fluid circuits 12 and 13 of both systems operate normally, and the power is supplied to the solenoid valves 35 and 36.
At this time, both spools 70, from the supply passages 17, 18 through the solenoid valves 35, 36 and one of the control passages 90, 91,
As shown in FIG. 1, both spools 70 and 71 receive this fluid pressure and oppose springs 86 and 87 at the axially outer stroke ends. It has switched to a certain first position. As a result, the passages 61 and 65, 62 and 66, 63 and 67, and 64 and 68 communicate with each other, and the high-pressure fluid in the supply passages 17 and 18 is supplied to the heads of the cylinder chambers 42 and 43 via the control valve 16. The fluid flows into each chamber on one of the side and each rod side, and the remaining fluid in each chamber on the other side is discharged to the discharge passages 19 and 20 via the control valve 16. The state at this time is the normal mode and the control valve 16
The cylinder 41 operates as desired by the pilot.

Next, in the normal mode as described above, both the fluid circuits 12 and 13 of the two systems fail, for example, in the supply passage.
If fluid pressure is not supplied to 17, 18 or power to both solenoid valves 35, 36 is cut off, solenoid valves 35, 36
36 are both switched, and one of the control passages 90 and 91 is connected to the tank 16. As a result, the fluid pressure guided to the other side surfaces of the spools 70 and 71 becomes low pressure (tank pressure). Therefore, as shown in FIG. 2, both spools 70 and 71 are axially inward (the other side) by springs 86 and 87 until the flanges 80 and 81 abut against the axially outer ends (one ends) of the sleeves 53 and 59, respectively. It is moved and switched to the second position. As a result, passage 6
1, 63 and passages 65, 67 are the second lands 7 of spools 70, 71.
4 and 75, and passages 62 and 64 and passages 66 and 68
Are blocked by the fourth lands 78, 79 of the spools 70, 71, but the passage 65 and the passage 66 communicate with each other through a throttle 82, and the passage 67 and the passage 68 communicate with each other through a throttle 83.
The state at this time is the damping mode. Even if an external force acts on the piston rod 47 from a rudder or the like, the movement speed of the piston rod 47 is limited, and free movement is suppressed.

Next, from the normal mode described above, the fluid circuit
If one of the failures 12, 13 occurs, for example, the supply passage 18 is supplied with high-pressure fluid, but the supply passage 17
When the fluid is no longer supplied to the control valve 90, only the solenoid valve 35 is switched to one control passage 90 of the one switching valve 55.
And the other control passage 93 of the other switching valve 56 has a low pressure. At this time, the fluid pressure guided to the other side of the spool 70 and the other side of the plunger 89 becomes low, but the fluid pressure guided to the other side of the spool 71 and the other side of the plunger 88 remains high. 88 moves toward the first position. The plunger 88 stops when the flange 96 comes into contact with the other end surface 94 of the sleeve 53 during the movement. At this time, the spool 70 of one of the switching valves 55 is urged by the spring 86 to move toward the second position, that is, toward the inside in the axial direction, but stops in contact with the plunger 88 in the middle. That is, the spool
70 switches to a third position between a first position and a second position.
As a result, the passage 61 and the passage 65 are cut off by the second land 74, and the passage 62 and the passage 66 are cut off by the fourth land 78. However, the passage 65 and the passage 66 are cut off by the second land 74 and the second land 74. 3
It communicates with the land 76 through an annular groove. The state at this time is the bypass mode, in which the fluid can freely flow between the two working chambers of the cylinder chamber 42, so that the piston 45 is freely moved and the piston 45 inhibits the operation of the piston 46. Will not be done. At this time, the spool 71 of the other switching valve 56 is moved to the first position by the high fluid pressure.
Since it is located at the position, the cylinder 41 is controlled only by the other fluid circuit 13.

Conversely, when high-pressure fluid is supplied to the supply passage 17 but no fluid is supplied to the supply passage 18, if one of the control passages 90 and the other of the switching valve 55 The other control passage 93 of the valve 56 remains at high pressure, but the other control passage 91 of the other switching valve 56 and the other control passage of the one switching valve 55
As shown in FIG. 3, only the plunger 89 moves until the flange 97 abuts the other end face 95 of the sleeve 59, so that the spool 71 of the other switching valve 56 moves to the first position and the second position. It is stopped at a third position between the two positions.
Thereby, the passage 67 and the passage 68 are communicated with each other, so that the fluid can freely flow between the two working chambers of the cylinder chamber 43, so that the piston 46 is freely moved,
46 does not hinder the operation of the piston 45. As described above, in this embodiment, the plungers 88 and 89 are provided on the other side of the spools 70 and 71, and the other end faces 94 and 95 as stoppers for defining the movement limits of these plungers 88 and 89 are provided. In spite of the structure, the switching valves 55 and 56 can be switched at three positions. Further, both the spools 70, 71 and the plungers 88, 89 are accommodated in one axially continuous casing 60, and the flanges 96, 97 are formed on the outer periphery of the plungers 88, 89. The molding operation is easy, and as a result, the structure can be made simple and inexpensive. Moreover, a pair of switching valves 55 and 56 are installed, and one of the switching valves
One control passage 90 of 55 and the other control passage 93 of the other switching valve 56 are connected, and the other control passage 92 of one switching valve 55 and one control passage 91 of the other switching valve 56 are connected to each other. Since the connection is made, the configuration of the control passages 90, 91, 92, and 93 can be simplified, and a plurality of fluid circuits, here, two fluid circuits 12, 13 can be switched at three positions.

In the above embodiment, the three-position switching valve of the present invention is applied to a fluid circuit of an aircraft, but may be applied to a fluid circuit of another device. In this case, the function of each of the three positions is suitable for the fluid circuit to be applied. Further, in the present invention, two or more fluid circuits may be switched by one spool. Further, in the present invention, both switching valves 55, 56
The casing 60 may not be shared but may be separate.

[0020]

As described above, according to the present invention, a fluid having a plurality of systems can be obtained with a simple structure and at a low cost.
The circuit can be switched in three positions.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view showing one embodiment of the present invention when a part is represented by a symbol and both spools are located at a first position.

FIG. 2 is a schematic sectional view when both spools are located at a second position.

FIG. 3 is a schematic cross-sectional view when one spool is located at a first position and the other spool is located at a third position.

[Explanation of symbols]

 55, 56 ... three-position switching valve 54, 57 ... spool chamber 60 ... casing 70, 71 ... spool 86, 87 ... spring 88, 89 ... plunger 90, 91 ... one control passage 92, 93 ... the other control passage 94, 95… Stopper

Continuation of the front page (56) References JP-A-60-4601 (JP, A) JP-A-59-175603 (JP, A) JP-A-62-180102 (JP, A) JP-A-53-76277 (JP) JP-A-64-41498 (JP, A) JP-A-4-215595 (JP, A) JP-A-53-111527 (JP, A) U.S. Pat. (US, A) US Patent 4,762,294 (US, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F15B 20/00 F15B 11/00 B64C 13/42

Claims (1)

(57) [Claims] 1. A and Luque pacing that having a spool chamber therein,
A spool housed in a spool chamber and axially movable between a first position at one stroke end and a second position at the other stroke end, a spring biasing the spool toward the second position, On the other side of this spool
A fluid pressure is guided to an axially movable plunger provided on the other side of the spool and the other side of the spool. When the fluid pressure is high, the spool is moved to a first position against a spring while the fluid pressure is low. At this time, the fluid pressure is guided to one of the control passages that allows the spool to move to the second position by the biasing force of the spring, and the other side of the plunger. When the fluid pressure is high, the plunger is moved to the first position. The plunger moving toward the first position is stopped in the middle of the movement when one control passage is formed at a low pressure and the other control passage is formed at a high pressure. And stopping the spool moving toward the second position by the urging force of the spring at the third position between the first position and the second position. 3 position switching, comprising: a stopper, the
One pair of valves is installed, and one control of one 3-position switching valve
The other control passage of the other three-position switching valve.
And the other of the three-position switching valve
Control passage and one control of the other three-position switching valve
3 characterized in that it is connected to a roll passage.
Position switching valve.