JPH10213237A - Spool valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attempt a stable operation and the reduction of the leak amount of a liquid by the off-center of a spool shaft by providing a bearing for guiding the movement in the axial direction of the spool by the inner cylinder of a valve sleeve and a shaft provided coaxially on the spool, in a spool valve for controlling the flow route by the movement of the spool. SOLUTION: The solenoid valve 1 as a spool valve is provided with a spool 3 installed in the inner cylinder 2a of a valve sleeve 2 and moved in the axial direction and a guide shaft 7 is extended toward the inside of the valve sleeve 2 so as to be coaxial to the inner cylinder 2a of the valve sleeve 2. The guide shaft 7 is inserted in a guide hole 3d provided on the spool 3 so that the spool 3 is guided and moved by the guide shaft 7 and the guide hole 3d. Meantime, the clearance size H1 between the guide shaft 7 and the guide hole 3d is set smaller than the clearance size H1 between the inner cylinder 2a of the valve sleeve 2 and the outer periphery surface of the flange part 3a and the spool 3 can be moved in the axial direction by a small off-center amount.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a spool valve,
The present invention relates to a technique capable of reducing the leakage of fluid from a valve portion and the operating force of a spool by suppressing the eccentricity of the spool.

[0002]

2. Description of the Related Art FIG. 4 is a view for explaining an example of a conventionally used solenoid valve 101, and shows a sectional view of a valve portion V101. In this solenoid valve 101, a valve portion V101 is a spool valve, and an inner cylindrical portion 10 of a cylindrical valve sleeve 102 is provided.
A spool 103 that moves in the axial direction with 2a as a sliding surface is provided.

The spool 103 is connected to a plunger 110 provided in a solenoid section S101 by a rod 109.
And the axial movement is performed according to the operation of the plunger 110. A flange portion 103a projecting from both ends in the axial direction so as to enlarge a part of the outer peripheral portion outward;
The outer peripheral surfaces of the flange portions 103a and 103b and the inner cylindrical portion 102a of the valve sleeve 102 are sliding surfaces. A spring 108 biases the spool 103 in the direction of the solenoid portion S101.

[0004] A coil 111,
A connector 112 for energizing the coil 111, a center post 113 for converging a magnetic flux generated by the coil 111 so as to effectively pass through the plunger 110, a side ring 114, and the like are provided.

The valve sleeve 102 has a first inflow port 104 at an open end, and an outflow port 105 and a second inflow port 106 on the side wall surface of the valve sleeve 102 in order from the first inflow port 104 side. I have.

FIG. 4A shows that the solenoid S101 is not in the energized state and the spool 108 is
Reference numeral 3 denotes a state where the right side is urged in the figure. In this state, the fluid flowing from the first inflow port 104 as shown by the arrow P1 is discharged from the outflow port 105 as shown by the arrow D1.

FIG. 4B shows a solenoid section S10.
Reference numeral 1 denotes a state where power is supplied, and a state where the spool 103 is moved to the left in the drawing against the urging force of the spring 108. In this state, the second inflow port 10
6 flows into the outflow port 1 as shown by the arrow P2.
05 is discharged as indicated by an arrow D1.

Accordingly, in the solenoid valve 101, the spool 103 is driven by the driving of the solenoid portion S101.
The opening and closing of the flow path of the valve section V101 by moving in the axial direction controls the flow rate and pressure of the fluid.

[0009]

FIG. 5 is an enlarged view of the section S1 in FIG. 4B. In the solenoid valve 101 as described above, the inner cylindrical portion 102a of the valve sleeve 102
Functions as a bearing for the flange portion 103a of the spool 103.

However, in order to improve the operation response characteristics of the solenoid valve 101, the inner cylinder portion 102a and the flange portion 1
03a, a predetermined amount of clearance portion 120 is provided.

The clearance amount h of the clearance portion 120 is usually as very small as about 30 μm to 100 μm (set to a predetermined value depending on the size and flow rate of the solenoid valve 101). It is managed as one of the important functional dimensions for operating the 101 smoothly.

Further, simply changing (small) the clearance amount h not only raises the sliding resistance as described above, but also necessitates the improvement of the component accuracy such as dimensional accuracy and surface roughness. This also affects the processing method, which may lead to an increase in cost, and cannot be easily performed.

The leakage of the fluid to be controlled from the clearance 120 is largely related to the performance characteristics of the solenoid valve 101, such as the pressure holding characteristics and the flow rate stability. To some extent it was acceptable.

However, such a clearance 120
Therefore, when a non-uniform biasing force is applied in the radial direction of the spool 103 due to the inflow of the fluid, the shaft of the spool 103 is eccentric as shown in FIG. Of the solenoid valve 10 when the inner cylinder portion 102a and the flange portions 103a and 103b of the spool 103 are in sliding contact with each other.
In this case, a large force is required to drive the motor 1 and the operation response characteristic is deteriorated.

Generally, an annular gap without eccentricity (FIG. 5)
(A) The flow rate Q of the fluid flowing through the clearance section 120)
Is found by the following equation (1).

[0016]

[Number 1] ^{Q = (πdh 3 / 12μl)} Δp where, d is the outer peripheral diameter of the flange portion 103a, h are the dimensions of the gap, the viscosity of μ fluid, l is the passage length, Delta] p is the channel Is the pressure difference between the inlet and the outlet. Also, in the case of an eccentric annular gap having an eccentricity where e = h as shown in FIG.

[0017]

[Number 2] ^{Q = (πdh 3 / 12μl)} Δp (1 + 3/2
(E / h) ² ) Therefore, comparing the above equations 1 and 2, when the maximum amount of eccentricity e = h is satisfied, the flow rate Q is 2.5 times larger than when e = 0. It can be seen that the amount of the fluid leaks from the clearance 120 becomes extremely large.

The present invention has been made to solve the above-mentioned problems of the prior art, and an object thereof is to reduce the eccentricity of the shaft of the spool 103 so that stable operation and fluid from the clearance portion 120 can be achieved. And to provide a spool valve that operates smoothly.

[0019]

In order to achieve the above object, according to the present invention, there is provided a valve sleeve in which a part of a flow path of a fluid is exposed to an inner cylindrical portion, and a shaft mounted on the inner cylindrical portion of the valve sleeve. A spool which is mounted so as to be movable in a direction, and which controls the flow path by movement of the spool, wherein a shaft coaxial with an inner cylinder portion of the valve sleeve, and a shaft of the spool And a bearing portion provided on a spool for guiding the movement in the direction.

As a result, the spool moves while being guided by the bearing portion and the shaft provided on the spool. Therefore, the eccentricity of the valve sleeve with respect to the inner cylinder portion which occurs when the spool moves while being guided by the inner cylinder portion of the valve sleeve of the spool. Can be suppressed.

Further, the amount of eccentricity of the spool generated by the shaft and the bearing portion is set to be smaller than the size of the gap between the inner cylindrical portion of the valve sleeve and the outer peripheral portion of the spool valve.

According to this, the spool can be moved in the axial direction with an eccentric amount smaller than the eccentric amount generated when the spool moves while being guided by the inner cylindrical portion of the valve sleeve.

It is also preferable that the shaft is provided with a communication passage communicating with a chamber of a valve sleeve which is axially separated by the spool.

Thus, the pressure in the chamber in the axial direction of the spool is balanced, and the movement of the fluid accompanying the change in the volume of the chamber during the movement of the spool can be performed through the communication passage, so that the movement of the spool can be smoothly performed. Thus, precise opening and closing operations of the valve can be performed.

It is also preferable that a solenoid is provided to make the spool movable in the axial direction.

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION

(Embodiment 1) FIG. 1 is a view for explaining a solenoid valve 1 as a spool valve according to a first embodiment of the present invention, and shows a sectional view of a valve portion V1.
In the solenoid valve 1, the valve portion V1 is a spool valve, and the inner cylinder portion 2a of the cylindrical valve sleeve 2 is provided.
Is provided with a spool 3 which is loaded in the shaft and moves in the axial direction.

One side of the spool 3 is urged in the direction of the solenoid S1 by a spring 8, and the other end 3e is in contact with the tip 9a of the rod 9 to prepare for the solenoid S1 when energized. Along with the movement of the plunger 10 in the direction of the valve portion V1, the rod 9 is pushed by the rod 9 to move leftward in the figure, and when power supply is stopped, axial movement is performed rightward in the figure. Figure 1 when not energized
And is located rightward by the spring 8.

At both ends in the axial direction, flange portions 3a and 3b are provided so as to protrude a part of the outer peripheral portion so as to increase the outer diameter, and the outer peripheral surfaces of the flange portions 3a and 3b are formed in the inner cylindrical portion of the valve sleeve 2. 2a.

The solenoid portion S1 includes a coil 11, a connector 12 for supplying electricity to the coil 11, a center post 13 for converging the magnetic flux generated by the coil 11 to pass through the plunger 10 effectively, and a side ring 1
4 etc. are provided.

The valve sleeve 2 has a first end at the open end 2b.
And an outflow port 5 and a second inflow port 6 on the side wall surface of the valve sleeve 2 in this order from the first inflow port 4 side.

Further, the open end 2b of the valve sleeve 2
Is fixed to a mounting flange 7a of the guide shaft 7. The guide shaft 7 extends toward the inside of the valve sleeve 2 so as to be coaxial with the inner cylindrical portion 2a of the valve sleeve 2.

The guide shaft 7 is inserted into a guide hole 3d as a bearing provided in the spool 3, and the spool 3 is guided by the guide shaft 7 and the guide hole 3d provided in the spool 3. Function to move.

Further, as shown in FIG. 1B, which is an enlarged view of the portion D1 in FIG. 1A, the dimension h1 of the gap between the guide shaft 7 and the guide hole 3d and the inner diameter of the valve sleeve 2 By setting the relationship of the gap H1 between the outer peripheral surface of the cylindrical portion 2a and the flange portion 3a (and 3b) as h1 <H1, the eccentric amount of the spool 3 becomes h1 at the maximum, and the spool 3 becomes the valve sleeve. The spool 3 can be moved in the axial direction with an eccentric amount smaller than the eccentric amount (maximum H1) generated when the movable member 2 is guided and moved by the inner cylinder portion 2a.

The operation of the solenoid valve 1 is the same as the operation described with reference to FIG. 4 of the prior art, in which the solenoid S1 is not energized and the spool 8 is biased by the spring 8 to the right in the figure. In the state of FIG. 1, a flow path is formed like the first inflow port 4 to the outflow port 5.

When the solenoid S1 is energized, the spool 3 moves to the left in the drawing against the urging force of the spring 8, and flows out of the second inflow port 6 through the constricted portion 3c of the spool 3. A flow path connected to the port 5 is formed.

FIG. 1 (c) is an enlarged view of the portion D2 in FIG. 1 (a) for explaining the structure near the other end 3e of the spool 3. As shown in FIG. The other end 3e of the spool 3 is provided with a half-moon-shaped communication hole 3f in the chamber R1 closer to the solenoid portion S1 than the flange portion 3b so as to balance a pressure change due to reciprocation of the spool 3. I have. The tip 9a of the rod 9 abuts on the central portion 3g sandwiched between the communication holes 3f.

The communication hole 3f connects the guide hole 3d to the chamber R1 so that when the solenoid portion S1 is energized, fluid flows into the chamber R1 from the guide hole 3d, and when the solenoid portion S1 is de-energized. Guide hole 3 from chamber R1
Since the fluid flows out to d, the reciprocating movement of the spool 3 is made smooth. The fluid moving between the chamber R1 and the guide hole 3d passes through the gap between the guide hole 3d and the guide shaft 7, communicates with the inflow port 4, and receives the axial front-rear pressure of the spool 3 (the pressure in the chamber R1 and the inflow port 4). It also works to balance pressure. When the dimension h1 of the gap is small, a communication passage such as a concave groove extending in the axial direction may be formed in a part of the outer periphery of the guide shaft 7, and the fluid may flow through the communication passage.

Therefore, in this solenoid valve 1, the spool 3 moves in the axial direction by driving the solenoid portion S1, thereby opening and closing the flow path of the valve portion V1 to control the flow rate and pressure of the fluid. By suppressing the eccentricity of the spool 3, it is possible to reduce the amount of fluid leakage from the gap between the inner cylindrical portion 2a of the valve sleeve 2 and the outer peripheral surface of the flange portion 3a (and 3b). Since the contact between the inner cylindrical portion 2a and the outer peripheral surface of the flange portion 3a does not occur, a stable operation is performed without increasing the driving force for driving the spool 3.

It is also preferable to appropriately improve the working accuracy of the guide shaft 7 and the guide hole 3d in order to improve the sliding accuracy of the guide shaft 3 and the guide hole 3d, or to perform surface treatment in order to reduce the sliding resistance. , Further improvement in performance can be expected.

(Embodiment 2) FIG. 2 is an explanatory sectional view showing a solenoid valve 21 according to a second embodiment of the present invention. The solenoid valve 21 includes a general valve section V2 and a solenoid section S2.

The valve portion V2 is a spool valve, and is provided with a spool 23 which is loaded in the inner cylinder portion 22a of the cylindrical valve sleeve 22 and moves in the axial direction.

The spool 23 is biased on one side in the direction of the solenoid S2 by a spring 28.
The other end 23e is in contact with the distal end 29a of the rod 29, and is pushed by the rod 29 to the left in the drawing with the movement of the plunger 30 provided in the solenoid S2 in the direction of the valve V2 during energization. When energization is stopped, axial movement is performed rightward in the figure. When power is not supplied, the actuator is biased by the spring 28 and is located rightward as shown in FIG.

Flanges 23a, 23b, and 23 project in such a manner that a part of the outer peripheral portion protrudes outward in the axial direction.
c, 23d, and the outer peripheral surfaces of these flange portions are opposed to the inner cylindrical portion 22a of the valve sleeve 23.

The solenoid portion S 1 includes a coil 31, a connector 32 for supplying electricity to the coil 31, a center post 33 and a lower plate 3 for converging the magnetic flux generated by the coil 31 so as to pass through the plunger 30 effectively.
4 etc. are provided.

The valve sleeve 22 has a drain port P1 at an open end 22b, and a drain port P2, a first control port P3, an inflow port P4, and a second control port on the side wall surface of the valve sleeve 22 from the open end 22b side. Port P5,
It has a drain port P6.

Further, the open end 2 of the valve sleeve 22
The mounting flange 27a of the guide shaft 27 is fixed to 2b. The guide shaft 27 extends toward the inside of the valve sleeve 22 so as to be coaxial with the inner cylindrical portion 22a of the valve sleeve 22.

The guide shaft 27 is inserted into a guide hole 23f as a bearing provided on the spool 23, and the spool 23 is guided by the guide shaft 7 and the guide hole 23f provided on the spool 23. Function to move. Note that the fitting relationship between the guide shaft 27 and the guide hole 23f is the same as that in the first embodiment.

As shown in FIG. 2 (b), which is a cross section C1 in FIG. 2 (a), the cross-sectional shape of the guide shaft 27 is a plane portion 27b of which a part of the outer peripheral surface is flattened off. Fluid communication passage 40 extending in the axial direction inside the guide hole 23f due to the presence of the flat portion 27b.
Has existed.

The spool 23 has a flange 23
a communicating hole 23g communicating with a constricted portion 23k between a and the flange portion 23b up to the guide hole 23f, and the flange portion 23
a constricted portion 2 between the flange portion 23c and the flange portion 23d by being connected to the guide hole 23f from the chamber R22 on the right side of d.
A communication hole 23h communicating up to 3 m is provided.

Therefore, the chamber R21 and the chamber R22 in the axial direction of the spool 23 communicate with each other through the communication passage 40 and the guide hole 23f, and the pressure in the chamber R21 and the chamber R22 in the axial direction of the spool 23 is reduced. Balanced. Also, when the spool 23 moves, the respective chambers R21, R2
It serves as a moving path for the fluid flowing into or out of the spool 2 and enables the spool 23 to smoothly reciprocate.

The communication hole 23g and the communication hole 23h allow precise movement of the spool 23 by allowing movement of the spool 23 at a higher speed by allowing the movement of the fluid between the communication passage 40 and the constricted portions 23k and 23m. It is possible.

In this solenoid valve 21, similarly to the first embodiment, the spool 23 moves in the axial direction by the driving of the solenoid portion S2 to open and close each port of the valve portion V2. In addition to controlling the pressure, the eccentricity of the spool 23 is suppressed by the guide shaft 27, so that the amount of leakage of fluid from the gap between the inner cylindrical portion 22a of the valve sleeve 22 and the outer peripheral surface of each flange portion is reduced. Further, since the inner cylindrical portion 22a of the valve sleeve 22 does not contact the outer peripheral surface of each flange portion, a stable operation is performed without increasing the driving force for driving the spool 23.

The flat portion 2 provided on the guide shaft 27
7b are the front and rear chambers R21 and R in the axial direction of the spool 23.
The pressure of 22 is balanced. Also, the spool 23
The movement path of the fluid flowing into or out of each of the chambers R21 and R22 during the movement of the spool 23 allows the spool 23 to smoothly reciprocate.

(Embodiment 3) FIG. 3 is an explanatory sectional view of a valve portion V1 of a solenoid valve 31 according to a third embodiment. In the solenoid valve 31, the same components as those in the first embodiment are denoted by the same reference numerals.

In the solenoid valve 31, the chamber R surrounded by the inner cylindrical portion 2a of the valve sleeve 2 on the side of the solenoid portion S1.
In order to smoothly change the volume accompanying the movement of the spool 3 in the chamber R32 surrounded by the guide hole 3d and the distal end of the guide shaft 7, the chamber R is provided at the other end 3e of the spool 3.
A communication hole 33 for communicating the chamber 32 with the chamber R1, and a drain port 34 for allowing the control fluid to flow into and out of the chamber R1.
It has.

The cross-sectional shape of the guide shaft 7 is not provided with a flat portion serving as a moving path of the fluid as in the second embodiment, but is the same as the cross-sectional shape of the guide hole 3d.

Accordingly, the solenoid valve 31 can operate at a high speed, and since there is no moving path of the fluid moving in the axial direction around the guide shaft 7, foreign matter and the like contained in the control fluid can be removed around the guide shaft 7. Without entering and biting into
Deterioration of operability can be prevented, and stable operation of the solenoid valve 31 can be maintained.

[0058]

According to the present invention, the spool is guided and moved by the bearing and the shaft provided on the spool, so that the eccentricity of the spool is suppressed, and the fluid eccentricity of the spool is reduced. A spool valve that reduces the amount of leakage and performs stable operation is obtained.

Further, by providing the shaft with a communication passage, the pressure in the chamber in the axial direction of the spool is balanced, and at the time of movement of the spool, the movement of the fluid accompanying the change in the volume of the chamber is performed by the communication passage. The movement of the valve becomes smooth, and a precise opening and closing operation of the valve can be performed.

[Brief description of the drawings]

FIG. 1 is a sectional configuration explanatory view of a first embodiment of a solenoid valve according to the present invention.

FIG. 2 is an explanatory sectional view of a solenoid valve according to a second embodiment of the present invention.

FIG. 3 is an explanatory sectional view of a solenoid valve according to a third embodiment of the present invention.

FIG. 4 is an explanatory view of a cross-sectional configuration of a conventional solenoid valve.

FIG. 5 is a diagram illustrating eccentricity during spool operation.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Solenoid valve 2 Valve sleeve 2a Inner cylinder part 2b Open end part 3 Spool 3a, 3b Flange part 3c Constriction part 3d Guide hole (bearing part) 3e End part 3f Communication hole 3g Central part 4 First inflow port 5 Outflow port 6 Second inflow port 7 Guide shaft (shaft) 8 Spring 9 Rod 9a Tip 10 Plunger 11 Coil 12 Connector 13 Center post 14 Side ring V1 Valve R1 chamber S1 Solenoid

Claims (4)

[Claims] 1. A valve sleeve having a part of a fluid flow path exposed to an inner cylindrical portion, and a spool mounted on the inner cylindrical portion of the valve sleeve so as to be movable in an axial direction. A spool valve for controlling the flow path, comprising: a shaft coaxial with an inner cylindrical portion of the valve sleeve; and a bearing portion provided on the spool for guiding axial movement of the spool by the shaft. A spool valve. 2. The spool according to claim 1, wherein the amount of eccentricity of the spool caused by the shaft and the bearing portion is set smaller than the size of the gap between the inner cylindrical portion of the valve sleeve and the outer peripheral portion of the spool valve. Spool valve. 3. The spool valve according to claim 1, wherein the shaft has a communication passage communicating with a chamber of a valve sleeve axially separated by the spool. 4. The spool valve according to claim 1, further comprising a solenoid capable of moving the spool in an axial direction.