JP2602749Y2 - Electromagnetic proportional pressure control valve - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic proportional pressure control valve capable of controlling a pressure corresponding to an exciting current of an electromagnetic solenoid.

[0002]

2. Description of the Related Art A pressure control valve of this type is disclosed in
The device described in Japanese Patent No. 29430 is conventionally known, and FIG. 5 shows the device. In this conventional pressure control valve, a spool hole 3 is formed in a valve body 1 and a spool 5 is slidably incorporated in the spool hole 3. Then, both ends of the spool are made to face the spring chambers 7, and the spring force of the springs 8 provided in the spring chambers 7, 7 is applied to the spool 5.
To act on. Further, piston holes 9, 9 are formed at both ends of the spool 5, and reaction force pistons 11, 11 are slidably inserted into the piston holes 9, 9. Reaction force pistons 11, 11 as described above
Has one end facing the feedback pressure chambers 13, and the other end in contact with the walls of the electromagnetic solenoids 15, 15. And this reaction force piston 11, 1
1 has cylindrical portions 17, 17 formed in the axial direction thereof, and cylindrical pins 19, 19 penetrated in a direction perpendicular to the axis of the cylindrical portions 17, 17;
It is fixed to.

Further, the plungers 21, 21 of the electromagnetic solenoids 15, 15 are brought into contact with the pins 19, 19. Therefore, when the pin 19 is pushed by the plunger 21, the spool 5 moves. However, the pins 19, 1
The holes of the reaction force pistons 11 , 11 through which the pin 9 is made are sufficiently larger than the diameter of this pin, so that even if the pin 5 is pushed to move the spool 5 as described above, the reaction force piston 9 9 can remain in that position. Normally, the spool 5 is kept at the neutral position shown in the figure by the action of the spring force of the springs 8. Now
When the electromagnetic solenoid 15 on the left side of the drawing is excited, the plunger 21 pushes the spool 5 via the pin 19,
The spool 5 moves rightward against the spring force of the right spring 8. Due to the rightward movement of the spool 5, the pressure fluid from the pump P is supplied to the actuator via the port 23. Further, the return fluid from the actuator at this time is returned to the tank T via the port 25.

When the pressure fluid is supplied to the actuator via the port 23 as described above, the pressure is also guided to the right feedback pressure chamber 13 through the passage 26 formed in the spool 5. Therefore, the pressure in the feedback pressure chamber 13 is changed to the right reaction force piston 11.
Act on. However, since the other end of the reaction force piston 11 is in contact with the wall surface of the electromagnetic solenoid 15 as described above, it does not move by the pressure action in the feedback pressure chamber 11. Therefore, this reaction force piston 11
The reaction force acting on the spool 5 acts on the spool 5 to move the spool 5 in a direction against the thrust of the plunger 21 , that is , the spool 5 is excited.
To the solenoid side . At this time spool 5
Is stopped at a position where the thrust of the plunger 21 of the electromagnetic solenoid 15, the reaction force of the reaction force piston 11 located on the opposite side to the plunger, and the spring force of the spring 8 are balanced. Then, the supply pressure to the actuator is determined according to the position where the spool 5 is stopped, but the pressure is eventually proportional to the exciting current of the electromagnetic solenoid 15.

[0005]

In the above-described conventional electromagnetic proportional pressure control valve, not only the reaction force piston 11 must be formed in a cylindrical shape, but also the electromagnetic solenoids 15, 15 Plungers 21, 21 must be inserted . In addition, a pin
19 through-holes are formed, and the pins 19 are passed through the holes,
It must be fixed to the spool 5. Therefore, there is a problem that the configuration becomes complicated and the assembling work becomes complicated accordingly. Further, the electromagnetic solenoid 15,
The fifteen plungers 21, 21 have cylindrical pins 19, 1,
Since abutted to 9, the tip contact area is reduced, there is a problem that much less stable. First
It is an object of the present invention to provide an electromagnetic proportional pressure control valve whose structure and assembly work are simple. A second object of the present invention is to provide an electromagnetic proportional pressure control valve in which a plunger and a stopper of an electromagnetic solenoid can maintain a stable state.

[0006]

According to a first aspect of the present invention, a spool is slidably incorporated in a spool hole formed in a valve body, and an electromagnetic solenoid plunger for applying thrust to the spool is provided at one or both ends of the spool. At the same time, a spring force of a spring is applied to one end or both ends of the spool facing the plunger, and a piston hole is formed in one end or both ends of the spool in the axial direction of the spool. While the piston is slidably inserted, one end of the reaction force piston is brought into contact with the stopper, and the other end is made to face the feedback pressure chamber formed in the piston hole, and the thrust of the plunger of the electromagnetic solenoid and the feedback pressure chamber The spool stops at a position where the pressure action of the spring and the spring force of the spring facing the thrust balance. An electromagnetic proportional pressure control valve to which the configuration is to assume. On the premise of the above control valve, the first invention is to form a stopper hole in a direction orthogonal to the piston hole, insert a stopper pin into the stopper hole, and fix both ends of the stopper pin to the valve body. In addition, the stopper hole is characterized in that it is sufficiently larger than the diameter of the stopper pin. In the second invention, a cylindrical stopper having a bottom is disposed outside one end or both ends of the spool while keeping the same premise as the first invention, and the reaction force piston is provided on the bottom of the stopper. While the other end is abutted, a guide member is provided in this cylindrical stopper so as to be movable in the axial direction, and a leg formed on the guide member is made to penetrate the bottom of the stopper and abut on the spool end, Moreover, the present invention is characterized in that the thrust of the plunger of the electromagnetic solenoid acts on the guide member.

[0007]

According to the first aspect of the present invention, the stopper pin is penetrated through the stopper hole formed in the spool, and the stopper pin is fixed to a member separate from the spool. The piston can apply a thrust to the spool while hitting the stopper pin. In the second invention, the thrust of the plunger of the electromagnetic solenoid acts on the spool via the guide member to move it. At this time, the reaction force piston applies a thrust to the spool while hitting the bottom of the stopper.

[0008]

In the first embodiment shown in FIG. 1, a spool hole 27 is formed in a valve body V, and a spool 29 is slidably incorporated in the spool hole 27. This spool 29
A spring 31 is provided at one end, and a piston hole 33 is formed along the axis at the other end. A reaction force piston 35 is slidably incorporated in the piston hole 33, and the opening end thereof is covered with a cap 37. A feedback pressure chamber 39 defined by the reaction force piston 35 is formed in the piston hole 33, and the feedback pressure chamber 39 is formed in the feedback pressure chamber 39.
Facing the tip of. Spool 29 as described above
In addition, a stopper hole 41 is formed at a position orthogonal to the piston hole 33, and a stopper pin 43 penetrates the stopper hole 41. The stopper pin 43 has two ends, as shown in FIG.
, But with respect to the diameter of the stopper pin 43,
The size of the stopper hole in the axial direction of the spool 29 is
It's big enough. Therefore, the spool 29
The inside of the spool hole 27 can slide within the range of the stopper hole.

The stopper pin 43 described above has
The reaction force piston 35 is abutted . Therefore, when pressure acts on the feedback pressure chamber 39, the reaction force piston 35 comes into pressure contact with the stopper pin 43, but its movement is restricted, and the thrust of the reaction force piston 35 is applied to the spool 29.
To move the spool 29 against the spring force of the spring 31. An electromagnetic solenoid 45 is provided on the side opposite to the spring 31, and a plunger 46 of the solenoid 45 is connected to the cap 37.
Is in contact with Further, an annular groove 47 is formed in the spool 29, and the annular groove 47 is always in communication with the output port 49. When the spool 29 is at the neutral position in the figure, the communication between the pump port 51 and the tank port 53 is cut off. The feedback pressure chamber 39 is
It is always in communication with the annular groove 47.

Next, the operation of the first embodiment will be described.
When the electromagnetic solenoid 45 is not excited, the spool 29 is located slightly to the left of the illustrated neutral position due to the action of the spring force of the spring 31. From this state, the electromagnetic solenoid 45 is slightly excited to move the spool 29 against the spring force of the spring 31 to maintain the illustrated neutral position. If the exciting current of the electromagnetic solenoid 45 is further increased from the neutral position, the thrust of the plunger 46 causes the spool 29 to move rightward in the drawing against the spring force of the spring 31. However, if the exciting current is reduced, the spring force of the spring 31 is superior to the thrust force of the plunger 46, so that the spool 29 moves leftward in the drawing by the action of the spring force of the spring 31. If the spool 29 is in the neutral position in the drawing, the communication of the annular groove 47 with the pump port 51 and the tank port 53 is interrupted as described above, so that no pressure fluid flows out of the output port 49.

When the exciting current of the electromagnetic solenoid 45 is reduced from the above state, the spring force of the spring 31 is superior to the thrust force of the plunger 46.
9 moves leftward in the drawing by the action of the spring force. When the spool 29 moves from the neutral state to the left in the drawing, the pump port 51 and the output port 49 communicate with each other via the annular groove 47. Therefore, the pressure fluid from the pump port 51 flows out of the output port 49 via the annular groove 47. At this time, the pressure on the output port 49 side is also guided to the feedback pressure chamber 39, so that
Act on. However, since the movement of the reaction force piston 35 is restricted by the stopper pin 43, the acting force on the reaction force piston 35 acts as a force for moving the spool 29 rightward in the drawing. Therefore, the force for moving the spool 29 rightward in the drawing at this time is
That is, the thrust of the plunger 46 of the electromagnetic solenoid 45 and the reaction force in the feedback pressure chamber 39. The force opposing the rightward movement is the spring force of the spring 31. Therefore, the spool 29 stops at a position where the thrust of the plunger + the reaction force of the feedback pressure chamber = spring force.

Contrary to the above, the greater the exciting current of the electromagnetic solenoid 45, the greater the thrust of the plunger 46. Therefore, the spool 29 moves rightward in the drawing against the spring force of the spring 31. , In this case,
The stop position of the spool is a position where the balance relationship is maintained. Therefore, if are prevented from communicating with the annular groove 47 and the pump port 51, if the annular groove 47 is communicated only with the tank port 53, exit i.e. the annular groove 47
The pressure in the force port 49 decreases, and this pressure
The spool 29 is guided into the pressure chamber 39 and acts on the spool 29 so that the spool 29 stops at a position where the thrust of the plunger 46 and the spring force of the spring 31 are balanced. In any case, the amount of wrap between the annular groove 47 and the pump port 51 is determined according to the moving position of the spool 29, so that the pressure output from the output port 49 eventually becomes the thrust of the plunger 46, that is, the electromagnetic solenoid 45. so that the determined corresponding to the exciting current. In the first embodiment, the output port
The pressure output from 49 is the excitation of the electromagnetic solenoid 45.
It is determined in inverse proportion to the current.

In the first embodiment as described above, the reaction force piston 11 is made to protrude outward from the spool 5 as in the prior art, and the plunger 21 is
Is not required to be complicated. As described above, according to the electromagnetic proportional pressure control valve of the first embodiment, since the entire configuration is simplified, the complexity of the assembling work can be eliminated. Although the first embodiment is of a type in which an electromagnetic solenoid is provided on only one of the spools, it is obvious that the first embodiment can also be applied to a type in which an electromagnetic solenoid is provided on both sides of the spool.

In the second embodiment shown in FIGS. 2 to 4, a spool 57 is slidably incorporated in a spool hole 55 formed in the valve body V, and both ends of the spool 57 are connected to the valve body V by electromagnetic force. It faces spring chambers 61, 61 formed by solenoids 59, 59. The centering springs 63, 6 are provided in the spring chambers 61, 61, respectively.
3 is provided, and the electromagnetic solenoids 59, 59 are in a non-excited state,
That is, in the normal state, the spool 57 is maintained at the neutral position shown in the drawing by the action of the centering springs 63, 63. As described above, the first to third annular grooves 65 to 69 are formed in the spool 57, but the first annular groove 65 always communicates with the pump port 71,
The three annular grooves 67 and 69 are always in communication with the tank port 73. In addition, first and second annular concave portions 75 and 77 are formed in the spool hole 55, and these annular concave portions 75 and 77 are formed.
The inflow / outflow ports 79 and 81 communicating with an actuator (not shown) are always in communication with 77.

Therefore, the pressure output from the inflow / outflow ports 79 and 81 is controlled by the restriction of the first annular groove 65 and the first or second annular concave portions 75 and 77. Further, at both ends of the spool 57, piston holes 83, 83 are formed along the axis thereof,
Outer ends of the piston holes 83 are opened to the spring chambers 61, and guide members 85 are fitted to the open ends. As shown in FIG. 3, the guide members 85, 85
It has a pair of leg pieces 85a. The leg piece 85a is fitted on the spool 57, and the electromagnetic solenoid 5
9, 59 plungers 60, 60 are in contact. However, cylindrical stoppers 87, 87 shown in FIG. 4 are provided outside the guide members 85, 85. The stoppers 87, 87 have a bottom 87a, and are provided on both sides of the bottom. And a hole 87b through which the leg piece 85a of the guide member 85, 85 passes. The stoppers 87, 87 have their bottoms 87 a facing the spool 57, and the opposite sides have the electromagnetic solenoids 59 of the spring chambers 61, 61.
It is in contact with the wall surface on the 59 side.

In the piston holes 83 , 83 , reaction force pistons 91, 91 are slidably incorporated, and the insides of the reaction force pistons 91, 91 are fed back into the feedback pressure chamber 9.
3, 93. This feedback pressure chamber 93,
93 is always in communication with the first and second annular concave portions 75, 77 communicating with the inflow / outflow ports 79, 81. Therefore, the pressure on the outflow / inflow ports 79, 81 acts on the feedback pressure chambers 93, 93. The outer ends of the reaction force pistons 91, 91 are brought into contact with the bottoms 87a of the stoppers 87, 87.

Next, the operation of the second embodiment will be described.
Now, from the illustrated neutral state, the left electromagnetic solenoid 59
Is excited, the plunger 60 is moved to the guide member 85.
The spool 57 is pushed rightward in FIG. When the spool 57 moves rightward in the drawing, the first annular groove 65
The aperture between the second annular groove 77 and the second annular recess 77 is increased,
The diaphragm between the first annular recess 7 and the first annular recess 75 is widened . Therefore, the pressure fluid from the pump P flows out of the inflow / outflow port 81 and is supplied to the actuator, and the return fluid from this actuator is returned from the inflow / outflow port 79 to the tank T via the tank port 73. .

At this time, the pressure on the side of the inflow / outflow port 81 from which the pressure fluid flows out acts on the right feedback pressure chamber 93, but the reaction force piston 91 in the feedback pressure chamber 93 is pressed by the stopper 87, The acting force on the reaction force piston 91 is a force for moving the spool 57 to the left. Therefore, as described above, the thrust of the plunger 60 of the left electromagnetic solenoid 59 causes the spool 57 to move to the right in response to the spring force of the left centering spring 63 and the reaction force piston 91 in the right feedback pressure chamber. The acting force will oppose. That is, the spool 57 is provided with a plunger thrust = acting force of the reaction piston 91 + spring 6
It stops at the position where the spring force of No. 3 is applied . In this balance position, the first annular groove 65 and the second annular recess 7
With the restriction of 7, the pressure output from the inflow / outflow port 81 is controlled. However, since the thrust of the plunger is proportional to the exciting current of the electromagnetic solenoid 59, the pressure output from the inflow / outflow port 79 or 81 is eventually proportional to the exciting current to the electromagnetic solenoid 59.

When the right electromagnetic solenoid 59 is excited to move the spool 57 to the left in the drawing, the thrust of the right plunger 60, the spring force of the left centering spring 63, and the left The fact that the spool 57 stops at the position where the acting force of the reaction force piston 91 is balanced is the same as the above case. Also, this second
In the case of the embodiment, the outer ends of the reaction force pistons 91, 91 are
Since the bottoms 87a of the stoppers 87, 87 are in surface contact with each other, a stable state can be maintained accordingly.

According to the control valve of the first invention, the whole structure is simplified, and the assembling work is also correspondingly simplified. According to the second invention of the control valve, and the stopper, and the plunger of the electromagnetic source <br/> solenoids, it is possible to remain stable.

[Brief description of the drawings]

FIG. 1 is a sectional view of a first embodiment.

FIG. 2 is a sectional view of a second embodiment.

FIG. 3 is an enlarged perspective view of a guide member according to a second embodiment.

FIG. 4 is an enlarged perspective view of a stopper according to a second embodiment.

FIG. 5 is a sectional view of a conventional electromagnetic proportional pressure control valve.

[Explanation of symbols]

 V valve body 27, 55 Spool hole 29, 57 Spool 31, 63 Spring 33, 83 Piston hole 35, 91 Reaction force piston 39, 93 Feedback pressure chamber 41 Stopper hole 43 Stopper pin 45, 59 Electromagnetic solenoid 46, 60 Plunger 85 Guide Member 85a Leg piece 87 Stopper 87a Bottom part

Claims (2)

(57) [Scope of request for utility model registration] A spool is slidably mounted in a spool hole formed in a valve body, and an electromagnetic solenoid plunger for applying a thrust to the spool is provided at one or both ends of the spool. The spring force of the spring is applied to one or both ends, and a piston hole is formed in the internal axial direction at one or both ends of the spool, and a reaction force piston is slidably inserted into the piston hole, One end of the reaction force piston is brought into contact with the stopper, and the other end is made to face a feedback pressure chamber formed in the piston hole. The thrust of the plunger of the electromagnetic solenoid and the pressure action in the feedback pressure chamber are opposed to those thrusts. Electromagnetic proportional pressure control valve configured to stop the spool at a position where the spring force of the side spring balances , A stopper hole is formed in a direction orthogonal to the piston hole, and a stopper pin is inserted into the stopper hole, and both ends of the stopper pin are
An electromagnetic proportional pressure control valve, wherein the valve is fixed to a valve body and the stopper hole is sufficiently larger than a diameter of a stopper pin. 2. A spool is slidably mounted in a spool hole formed in a valve body, and an electromagnetic solenoid plunger for applying a thrust to the spool is provided at one or both ends of the spool. The spring force of the spring is applied to one or both ends, and a piston hole is formed in the internal axial direction at one or both ends of the spool, and a reaction force piston is slidably inserted into the piston hole, One end of the reaction force piston contacts the stopper, and the other end faces the feedback pressure chamber formed in the piston hole. The thrust of the plunger of the electromagnetic solenoid, the pressure action in the feedback pressure chamber, and the side facing the thrust. Electromagnetic proportional pressure control valve configured to stop the spool at a position where the spring force of the spring is balanced , A cylindrical stopper having a bottom is disposed outside one end or both ends of the spool, and the other end of the reaction force piston is brought into contact with the bottom of the stopper. A guide member is provided in the stopper so as to be movable in the axial direction, and a leg formed on the guide member passes through the bottom of the stopper and abuts on the spool end.
Was, moreover, the electromagnetic proportional pressure control valve, characterized in that the arrangement for applying a thrust of the electromagnetic solenoid plunger in the guide member.