JP2006348982A - Three-way solenoid valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To increase the lift amount of a ball valve in a three-way solenoid valve driving a flow passage selecting part using the ball valve by a solenoid. <P>SOLUTION: A discharge side partition wall 18 partitioning an output chamber 15 from a discharge chamber 16 is formed to be movable from a position where a step valve 28 is seated on the seat part 22a of a discharge valve port 22 into the output chamber 15. When the solenoid valve is energized and while a shaft 5 is being moved, the step valve 28 is seated on the seat part 22a of the discharge valve port 22, and the discharge side partition wall 18 is pressed by the step valve 28 to move into the output chamber 15. Accordingly, the lift amount of the ball valve 4 is increased. Even if the discharge side partition wall 18 is pushed back due to the rise of an input hydraulic pressure, the discharge side partition wall 18 abuts on a valve base 3. Then, a hydraulic pressure received by the discharge side partition wall 18 is received by the valve base 3, a push-back force received by the shaft 5 is reduced, and the discharge valve port 22 is not opened. Even if a magnetic attractive force is generated by a dark current when a current is not passed, the shaft 5 is pushed back by the hydraulic pressure received by the discharge side partition wall 18 to securely return the shaft. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to a three-way solenoid valve that drives a flow path switching unit using a ball valve by a solenoid, and relates to a technique suitable for use in, for example, hydraulic pressure switching.
Hereinafter, in the movement direction of the shaft and the moving core, the movement direction toward the input chamber is referred to as “ball valve pressing direction”, and the movement direction toward the side different from the input chamber is referred to as “step valve separation direction”. I will explain.

(Prior art 1)
A conventional three-way solenoid valve for switching the hydraulic pressure will be described with reference to FIG. In the following description, the same reference numerals as those in the first embodiment are used.
The flow path switching unit 1 includes an input port 11, an output port 12, and a discharge port 13, and has an input valve port 21 and a discharge valve port 22 inside. The input valve port 21 is opened and closed by a ball valve 4 and discharged. The valve port 22 is configured to be opened and closed by a step valve 28 of the shaft 5 that drives the ball valve 4.
The shaft 5 is driven in the axial direction by the moving core 32 of the solenoid 2.

(3-way solenoid valve operation)
The operation of the conventional three-way solenoid valve will be described.
(A1) In the energized OFF state, as shown in FIG. 8A, the ball valve 4 is seated on the seat portion of the input side partition wall 17 by the input hydraulic pressure, and the hydraulic pressure from the input port 11 to the output port 12 is cut off. is doing.
Further, the shaft 5 is subjected to a rightward spring load due to the urging force of the return spring 6, and in the energized OFF state, the moving core 32 is pressed against the plate 38, and the step valve 28 of the shaft 5 is a discharge valve port. The oil pressure is discharged from the output port 12 to the discharge port 13.

(A2) When energized, a magnetic attractive force α is generated between the moving core 32 and the stator core 37 (air gap), and the moving core 32 moves in the ball valve pressing direction (left direction in the figure) while pushing the shaft 5. To do.
While the shaft 5 moves in the ball valve pressing direction, the pressing shaft 25 at the tip of the shaft 5 abuts on the ball valve 4 (see FIG. 8B), and then the ball valve 4 is lifted. As a result, the input valve port 21 is opened and the input port 11 and the output port 12 are communicated.
(A3) When the shaft 5 further moves in the ball valve pressing direction, the step valve 28 of the shaft 5 is seated on the seat portion of the discharge valve port 22 (see FIG. 8C), and the shaft 5 moves in the ball valve pressing direction. Is stopped, and the communication between the output port 12 and the discharge port 13 is blocked.
As a result, the hydraulic pressure supplied from the input port 11 is output from the output port 12.

(A4) When the energization is stopped, the magnetic attractive force α in the air gap disappears, and the urging force of the return spring 6 causes the shaft 5 to push the moving core 32 while moving in the step valve separation direction (right direction in the figure). Moving.
When the shaft 5 moves in the step valve separation direction, the step valve 28 of the shaft 5 is separated from the seat portion of the discharge valve port 22, the discharge valve port 22 is opened, and the output port 12 and the discharge port 13 are communicated.
Furthermore, when the shaft 5 moves in the step valve separation direction, the ball valve 4 is seated on the seat portion of the input valve port 21 and the communication between the input port 11 and the output port 12 is blocked.
Thereafter, the moving core 32 is pressed against the plate 38 and returns to the energization OFF state shown in (A1) above.

(Force received by shaft 5)
Next, the relationship between the air gap and the force received by the shaft 5 will be described with reference to FIG. The shaft 5 is displaced between a position where the energization is OFF (a position where the moving core 32 contacts the plate 38) and a position where the step valve 28 is seated on the seat portion of the discharge valve port 22.
The displacement of the shaft 5 is as follows: (1) when the power is turned off until the pressing shaft 25 contacts the ball valve 4; (2) the pressing shaft 25 contacts the ball valve 4; It can be divided into two until it is seated on the seat.
Here, the air gap when the power is off is d1 {see FIG. 8A}, the air gap when the pressing shaft 25 is in contact with the ball valve 4 is d2 {see FIG. 8B}, and the step valve 28 is The air gap when seated on the seat portion of the discharge valve port 22 is d3 {see FIG. 8C}.

When the shaft 5 is energized, it receives a magnetic attraction force α directed to the left in the figure corresponding to the air gap.
On the other hand, the shaft 5 receives a pushing force β directed in the right direction in the figure by the spring load and hydraulic pressure of the return spring 6.
This pushing-back force β is classified according to the displacement position of the shaft 5.
(I) From the time of energization OFF until the pressing shaft 25 comes into contact with the ball valve 4 (d1 to d2), the shaft 5 receives the pushing back force β1 due to the “spring load”.
(Ii) The shaft 5 is “spring load” + “input hydraulic pressure (input chamber 14) until the pressing shaft 25 contacts the ball valve 4 until the step valve 28 is seated on the seat portion of the discharge valve port 22 (d2 to d3). And the load received by the ball valve 4 due to the pressure difference between the output chamber 15 and the hydraulic pressure corresponding to the pressure receiving area of the input valve port 21).
(Iii) With the step valve 28 seated on the seat portion of the discharge valve port 22 (d3), the shaft 5 receives “spring load” + “discharge hydraulic pressure (the step valve 28 receives the pressure difference between the output chamber 15 and the discharge chamber 16). Hydraulic pressure: hydraulic pressure corresponding to the pressure receiving area of the discharge valve port 22) ”is received.

  Then, a resultant force γ of “magnetic attraction force α” + “pushing force β (any of β1, β2, β3)” is generated in the shaft 5, and if the resultant force γ is positive (α> β), the shaft 5 Moves in the ball valve pressing direction. Conversely, if the resultant force γ is negative (α <β), the shaft 5 moves in the step valve separation direction.

(Setting of air gap d2)
The three-way solenoid valve may be used in an automobile (for example, a hydraulic control device for an automatic transmission), and the hydraulic pressure supplied to the input port 11 may fluctuate greatly or the energization current of the solenoid 2 may fluctuate.
FIG. 9A shows “magnetic attraction force α” and “push-back force β (when the hydraulic pressure supplied to the input port 11 is maximum (maximum pressure) and the energization current of the solenoid 2 is minimum (minimum operating current). β1, β2, β3) ”.
9A, in order to open the ball valve 4 with the air gap d2 when energized, in the air gap d2, the “magnetic attraction force α” due to the minimum operating current is changed to the “pushback force” at the maximum pressure. It is necessary to make it larger than “β2” (in d2: α of the lowest operating current> β2 of the highest pressure).
That is, the air gap d2 is set such that α> β2 even at the highest pressure and the lowest operating current.

(Setting of air gap d3)
On the other hand, although it has been described above that the magnetic attractive force α in the air gap disappears in the energized OFF state, a small amount of magnetic attractive force α is generated in the air gap due to the dark current in the actually energized OFF state.
FIG. 9B shows the “magnetic attraction force α” and “push-back force β (β1, β2,...) When the hydraulic pressure supplied to the input port 11 is the lowest (minimum pressure) and dark current flows through the solenoid 2. β3) ”is shown.
9B, when the energization is stopped, the stepped valve 28 is separated from the seat portion of the discharge valve port 22 by the air gap d3. It is necessary to make “β3” larger than “magnetic attraction force α” due to dark current (in d3: α of dark current <β3 of minimum pressure).
That is, the air gap d3 is set to satisfy α <β3 even at the lowest pressure and dark current.

(First problem)
The three-way solenoid valve is required to increase the lift amount of the ball valve 4 in order to greatly open the ball valve 4 when energized.
Since the lift amount of the ball valve 4 is between the air gaps d2 to d3, the lift amount of the ball valve 4 can be increased by increasing the air gap d2 or decreasing the air gap d3.
In order to increase the air gap d2, it is necessary to decrease the “pushback force β2”. In order to reduce the “pushback force β2”, in order to reduce the differential pressure received by the ball valve 4, the opening diameter (pressure receiving area) of the input valve port 21 must be reduced, and the flow rate of the input valve port 21 is reduced. It will decrease.
For this reason, it is conceivable to reduce the air gap d3.
In order to reduce the air gap d3, it is necessary to increase the “pushback force β3”. Increasing the “pushback force β3” can be achieved by increasing the opening diameter (pressure receiving area) of the discharge valve port 22 in order to increase the differential pressure received by the step valve 28.

(Prior art 2)
FIG. 10 shows a three-way solenoid valve in which the opening diameter (pressure receiving area) of the discharge valve port 22 is increased.
The three-way solenoid valve having a larger opening diameter (pressure receiving area) of the discharge valve port 22 increases the differential pressure received by the step valve 28. Therefore, as shown in FIG. The step valve 28 can be reliably separated from the seat portion of the discharge valve port 22 even if the magnetic attractive force α due to the dark current is generated when the energization is stopped.

(Second problem)
However, when the opening diameter (pressure receiving area) of the discharge valve port 22 is increased, the “push-back force β3” increases, so that the step valve 28 needs to be seated on the seat portion of the discharge valve port 22 while the solenoid 2 is energized. Even when the input hydraulic pressure is the maximum pressure, the “pushback force β3” is the maximum, and the magnetic attraction force α is decreased by the minimum operating current, as shown in FIG. Thus, the discharge valve port 22 is opened. For this reason, it is necessary to set the opening diameter (pressure receiving area) of the discharge valve port 22 so that α> β3 is maintained even at the maximum pressure and the minimum operating current. It is difficult to increase (pressure receiving area).
Since the air gap d3 is determined by the dimensions of a plurality of parts, the variation is large. Further, since the air gap d3 must be set to a value that does not cause a magnetic short circuit due to contact between the moving core and the stator core, there is a limit to reducing the air gap d3.

As described above, in order to maintain α> β3 even when the opening diameter (pressure receiving area) of the discharge valve port 22 is increased, even when the maximum pressure and the minimum operating current are maintained, it is necessary to open the discharge valve port 22. The diameter (pressure receiving area) cannot be increased, and the air gap d3 cannot be reduced. That is, it is difficult to greatly increase the lift amount of the ball valve 4 by increasing the opening diameter (pressure receiving area) of the discharge valve port 22.
JP 2004-286097 A

  The present invention has been made in view of the above problems, and an object thereof is to provide a three-way electromagnetic valve capable of increasing the lift amount of the ball valve.

[Means of claim 1]
The discharge-side partition of the three-way solenoid valve employing the means of claim 1 is a member separate from the valve base, and is provided so as to be movable into the output chamber from the position where the step valve is seated on the seat portion of the discharge valve port. . When the shaft moves in the input chamber direction (ball valve pressing direction), after the step valve is seated on the seat portion of the discharge valve port during the movement of the shaft, the discharge-side partition wall is pressed by the step valve and the output chamber Move to.
Thus, when the solenoid is energized, the shaft does not stop at the air gap d3 when the step valve is seated on the seat portion of the discharge valve port, and remains in the state where the step valve is seated on the seat portion of the discharge valve port. Then, the ball valve is moved in the valve opening direction. Here, d3 ′ is an air gap when the shaft stops moving in the input chamber direction (ball valve pressing direction) with the step valve seated on the seat portion of the discharge valve port.
That is, when the solenoid is energized, the shaft does not stop at the air gap d3 but strokes to the air gap d3 ′.

  As a result, the pushing force β received by the shaft is equal to (iii) in addition to the pushing forces β1, β2, and β3 (β3 = pushing force at the time of the air gap d3) shown in (i) to (iii) above. ) Until the step valve contacts the seat part of the discharge valve port and the shaft stops moving (d3 to d3 ′), the shaft is “spring load” + “discharge hydraulic pressure (hydraulic pressure received by the step valve in the discharge valve port)” + Restraining force β3 ′ by “movable partition wall hydraulic pressure (hydraulic pressure received by discharge side partition wall)” is received.

(Operation at maximum pressure and minimum operating current)
In the range of the air gaps d3 to d3 ′, the step valve of the shaft is seated on the seat portion of the discharge valve port, and the discharge side partition receives the discharge hydraulic pressure on a large surface, so the “pushback force β3 ′” is Rise.
For this reason, when the input hydraulic pressure is the highest pressure and the “pushback force β3 ′” increases and the magnetic attraction force α decreases due to the minimum operating current, α <β3 ′ and α is pushed back in the step valve seating direction. At this time, the state in which the step valve of the shaft is seated on the seat portion of the discharge valve port is maintained, so the discharge valve port does not open.

When the shaft is pushed back in the step valve separation direction and the discharge side partition wall moves to the position of the air gap d3 (position where the step valve starts to contact the seat portion of the discharge valve port), the discharge side partition wall becomes the axis of the valve base. “Moving partition wall hydraulic pressure (hydraulic pressure received by the discharge-side partition wall)” is received by the valve base in contact with the direction, and the pushback force received by the shaft becomes “pushback force β3”.
Since the “pushback force β3” is the hydraulic pressure received by the step valve in the discharge valve port as described above, the opening diameter (pressure receiving area) of the discharge valve port is not set large as in the case of the prior art 1, The return force β3 ”can be suppressed. For this reason, even if it is the highest pressure and the lowest operating current, α> β3 can be reliably maintained, and there is no problem that the discharge valve port opens.

(Operation at minimum pressure and dark current)
Even when the solenoid is switched from the energized state to the energized OFF state and a small amount of magnetic attractive force α is generated in the air gap due to the dark current, the discharge side partition wall has a large discharge hydraulic pressure in the range of the air gaps d3 to d3 ′. Since the pressure is received by the surface, the discharge side partition wall and the shaft receive a large “pushback force β3 ′”. This ensures that α <β3 ′ and the shaft is pushed back in the step valve separation direction.
In this way, the air gap is widened and the air gap is widened to the position d3, so that the magnetic attractive force α due to the dark current is sufficiently small. As a result, α <β3 can be reliably established, and the shaft can be reliably returned to the stop position.

(Effect of Claim 1)
As described above, the lift amount of the ball valve is determined by providing the discharge side partition so that it can be displaced in the axial direction while the step valve is seated on the seat portion of the discharge valve port during the movement of the shaft. The air gap can be reduced from d3 of the prior art to d3 ′. That is, the lift amount of the ball valve can be increased as compared with the prior art.

[Means of claim 2]
A coil is energized between the moving core and the stator core of the three-way solenoid valve employing the means of claim 2, and the moving core and the stator core come into contact with each other and are magnetically coupled while the moving core is closest to the stator core. Magnetic shielding means is provided to prevent this. Thereby, the air gap d3 ′ is determined by the magnetic blocking means.
Thus, since the air gap d3 ′ can be set by the magnetic blocking means, the air gap d3 can be set small, and the lift amount of the ball valve can be set to the maximum value.

[Means of claim 3]
The magnetic shut-off means in the three-way solenoid valve adopting the means of claim 3 is a non-magnetic spacer made between the moving core and the stator core.
Thereby, the lift amount of the ball valve can be set to the maximum value only by disposing a non-magnetic spacer between the moving core and the stator core.

  The three-way solenoid valve of the best mode 1 includes a solenoid that includes a coil that generates a magnetic force when energized, a moving core that is magnetically attracted in one axial direction by the magnetic force generated by the coil, and a side on which the moving core is magnetically attracted. And a flow path switching unit disposed in the.

The flow path switching unit includes a valve base, a ball valve, and a shaft.
The valve base includes an input port for receiving fluid, an output port for outputting fluid, and a discharge port for discharging fluid. The valve base also communicates with an input chamber communicating with the input port, an output chamber communicating with the output port, and a discharge port. A discharge chamber is disposed on the axis of the moving core. The valve base has an input side partition that partitions the input chamber and the output chamber, a discharge side partition that partitions the output chamber and the discharge chamber, and an input valve port formed in the input side partition, and a discharge side. A discharge valve port formed in the partition wall is provided on the axis of the moving core.
The ball valve is disposed in the input chamber and is seated on the input valve port by the fluid pressure in the input chamber. The shaft has a pressing shaft that is inserted into the input valve port from the output chamber side and can displace the ball valve to the input chamber side, and is seated on the seat portion of the discharge valve port from the discharge chamber side. Thus, a step valve capable of closing the discharge valve port is provided at an intermediate position in the axial direction. This shaft is slidably supported on the axis of the moving core, and is driven from the discharge chamber side to the input chamber side by a magnetic attractive force applied to the moving core.

In the three-way solenoid valve, when the moving core is magnetically attracted in the direction of the ball valve by energizing the coil and the shaft moves in the direction of the input chamber, first, the pressing shaft at the tip of the shaft displaces the ball valve and the input valve port Is opened to allow the input chamber and the output chamber to communicate with each other, and then a step valve formed in the middle of the shaft is seated on the seat portion of the discharge valve port to block the communication between the output chamber and the discharge chamber.
The discharge-side partition wall is a separate member from the valve base, and is provided movably in the output chamber from the position where the step valve is seated on the seat portion of the discharge valve port, and the shaft is in the input chamber direction (ball valve pressing direction) When the shaft moves, the step valve is seated on the seat portion of the discharge valve port during the movement of the shaft, and then the discharge side partition wall is pressed by the step valve and moves into the output chamber.

A first embodiment will be described with reference to FIG.
The three-way solenoid valve shown in the first embodiment is mounted on, for example, a hydraulic control device for an automatic transmission of an automobile. Specifically, the three-way solenoid valve shown in the first embodiment is disposed in oil inside a case of a hydraulic controller that is oil-tightly sealed from the outside. And a solenoid 2 for driving the unit 1.
In the first embodiment, the basic configuration of the three-way solenoid valve will be described first, and then the features of the first embodiment will be described.

(Description of flow path switching unit 1)
The flow path switching unit 1 includes a valve base 3, a ball valve 4, a shaft 5, and a return spring 6.
The valve base 3 has a substantially cylindrical shape, and includes an outer cylinder 7 inserted into a hydraulic circuit (oil passage forming component) of a hydraulic controller (not shown) and an inner cylinder 8 inserted into the solenoid 2. .
The external cylinder 7 has an input port 11 to which oil (an example of a fluid) pumped from an oil pump (not shown) is input, an output port 12 that outputs oil to a hydraulic actuator, and a low pressure such as oil pan. A discharge port 13 for discharging to the side is provided. In the first embodiment, the input port 11 is provided at the end (left end in FIG. 1) of the outer cylinder 7, and the output port 12 and the discharge port 13 are provided so as to penetrate in the radial direction of the outer cylinder 7. .

The inside of the outer cylinder 7 is partitioned into an input chamber 14 that communicates with the input port 11, an output chamber 15 that communicates with the output port 12, and a discharge chamber 16 that communicates with the discharge port 13. An input chamber 14, an output chamber 15, and a discharge chamber 16 are arranged toward the front.
Here, the input chamber 14 and the output chamber 15 are partitioned by an input-side partition wall 17 supported by the inner wall of the outer cylinder 7, and the output chamber 15 and the discharge chamber 16 are also supported by the inner wall of the outer cylinder 7. It is defined by the discharge side partition wall 18. The support structure for the discharge-side partition wall 18 will be described in the features of Example 1 described later.
The input side partition wall 17 and the discharge side partition wall 18 are disposed to face each other inside the outer cylinder 7. An input valve port 21 that communicates the input chamber 14 and the output chamber 15 is provided at the center of the input side partition wall 17. On the other hand, a discharge valve port 22 that communicates the output chamber 15 and the discharge chamber 16 is also provided at the center of the discharge-side partition wall 18. Both the input valve port 21 and the discharge valve port 22 are provided on the axis of the shaft 5 and the moving core 32 described later.

  A sliding contact hole 23 that supports the shaft 5 (specifically, a large-diameter shaft 27 described later) slidably in the axial direction is formed in the inner cylinder 8.

  The ball valve 4 is disposed in the input chamber 14 and is seated on the seat portion 21a of the input valve port 21 by the hydraulic pressure in the input chamber 14, and is assembled in the input chamber 14 from the end of the external cylinder 7. A ball holder 24 is supported inside the input chamber 14 so as to be displaceable in the axial direction. Of course, the ball holder 24 is provided to guide the hydraulic pressure supplied from the input port 11 to the input chamber 14 side.

The shaft 5 includes a pressing shaft 25, a medium diameter shaft 26, and a large diameter shaft 27 from the left side of FIG. 1 (input chamber 14 side) to the right side of FIG. 1.
The pressing shaft 25 is provided at the left end of the shaft 5 in FIG. 1 and has a smaller diameter than the input valve port 21 and the discharge valve port 22. The pressing shaft 25 is inserted into the input valve port 21 from the output chamber 15 side and is a ball valve. 4 is a pressing part capable of displacing 4 toward the input chamber 14.
The medium diameter shaft 26 is provided with a slightly larger diameter than the pressing shaft 25, and moves in the axial direction in the discharge chamber 16.
At the step between the pressing shaft 25 and the medium diameter shaft 26, a step valve 28 is provided that can be seated on the seat portion 22a of the discharge valve port 22 from the discharge chamber 16 side and close the discharge valve port 22. That is, the shaft 5 includes a step valve 28 at an intermediate position in the axial direction.
The large-diameter shaft 27 is provided with a slightly larger diameter than the medium-diameter shaft 26 and is supported by the above-described sliding contact hole 23 so as to be slidable in the axial direction. That is, the shaft 5 is supported by the sliding contact hole 23 so as to be slidable in the axial direction.

  The return spring 6 is a compression coil spring that urges the shaft 5 toward the solenoid 2, and is between a step between the discharge-side partition wall 18 and the large-diameter shaft 27 (a step between the medium-diameter shaft 26 and the large-diameter shaft 27). Arranged in a compressed state. As a result, the end face on the right side of FIG. 1 of the shaft 5 is always in contact with the end face of the moving core 32 described later, and the moving core 32 is also urged to the right side of FIG.

(Description of solenoid 2)
The solenoid 2 includes a coil 31, a moving core 32, a magnetic stator 33, and a connector 34.
The coil 31 generates a magnetic force when energized to form a magnetic flux loop passing through the moving core 32 and the magnetic stator 33, and a conductive wire (insulating coating is provided around the resin bobbin 31a). A lot of enameled wire).

The moving core 32 is a magnetic metal having a substantially cylindrical shape (for example, a ferromagnetic material such as iron).
The moving core 32 slides directly with the inner peripheral surface of the magnetic stator 33 (specifically, the inner peripheral surface of an inner peripheral yoke 35b described later).
As described above, the moving core 32 is in contact with the shaft 5 and is urged to the right side in FIG. 1 together with the shaft 5 by the urging force of the return spring 6.
Note that a breathing hole 32 a penetrating in the axial direction is formed inside the moving core 32.

The magnetic stator 33 includes a yoke 35, a stator ring 36, and a stator core 37.
The yoke 35 includes an outer peripheral yoke 35a covering the outer periphery of the coil 31, an inner peripheral yoke 35b disposed on the inner periphery of the coil 31 and covering the outer periphery of the moving core 32, and the outer yoke 35a and the inner periphery on the right side of the coil 31 in FIG. An annular yoke 35c that magnetically couples the yoke 35b is integrally provided. The yoke 35 is made of a magnetic material (for example, a ferromagnetic metal such as iron).
The inner peripheral yoke 35b supports the moving core 32 so as to be slidable, and transfers the magnetic flux in the radial direction with the moving core 32.
The plate 38 attached to the end portion (right end in FIG. 1) of the yoke 35 is a stopper that restricts the movement of the shaft 5 in the right direction in FIG.

  The stator ring 36 is a magnetic body having a ring disk shape (for example, a ferromagnetic metal such as iron). The outer peripheral end of the stator ring 36 is caulked to the open end (the left end in FIG. 1) of the outer peripheral yoke 35a and is mechanically and magnetically coupled to the yoke 35. Further, the inner peripheral end of the stator ring 36 is press-fitted into the stator core 37 (in this embodiment, the inner cylinder 8 of the valve base 3) and is mechanically and magnetically coupled to the stator core 37 (inner cylinder 8). .

The stator core 37 is opposed to the end of the moving core 32 on the magnetically attracted side (left end in FIG. 1) in the axial direction, and magnetically attracts the moving core 32 by the magnetic force generated by the coil 31 (for example, iron or the like). An air gap (magnetic attraction gap) is formed at the opposing portion of the stator core 37 and the moving core 32.
Here, in the first embodiment, the inner cylinder 8 of the valve base 3 inserted into the solenoid 2 also serves as the stator core 37 of the solenoid 2, so that the inner cylinder 8 acts as the stator core 37. Is provided by a magnetic material (for example, a ferromagnetic metal such as iron).
In the first embodiment, a magnetic blocking means is provided between the moving core 32 and the stator core 37 (air gap) to prevent the moving core 32 and the stator core 37 from coming into contact with each other and being magnetically coupled. This magnetic shielding means will be described later.

  The connector 34 is a connection means for making an electrical connection with an electronic control device (not shown) for controlling the three-way solenoid valve via a connection line, and terminals 34a connected to both ends of the coil 31 are provided therein. Has been placed.

(Characteristics of Example 1)
Conventionally, there is a demand to increase the lift amount of the ball valve 4.
Thus, the three-way solenoid valve of the first embodiment employs the following technology.
As shown in FIG. 1B, the discharge-side partition wall 18 is a separate member from the valve base 3, and from the position where the step valve 28 is seated on the seat portion 22 a of the discharge valve port 22, It is provided to be movable in the valve pressing direction (left direction in FIG. 1). Since the discharge side partition wall 18 is a partition wall that partitions the output chamber 15 and the discharge chamber 16, the discharge side partition wall 18 is formed in the output chamber 15 from the position where the step valve 28 is seated on the seat portion 22 a of the discharge valve port 22. Even if it moves, oil is not leaked from the fitting portion between the valve base 3 and the discharge-side partition wall 18 (the axial sliding portion of the discharge-side partition wall 18).
Then, when the coil 31 is energized and the shaft 5 moves in the ball valve pressing direction, after the step valve 28 is seated on the seat portion 22a of the discharge valve port 22 during the movement of the shaft 5, the discharge side partition wall 18 is stepped. The valve 28 is pressed to move into the output chamber 15.

  The discharge-side partition wall 18 is urged toward the discharge chamber 16 by the second return spring 41, and abuts against the axial contact wall 3a of the valve base 3 when no external load is applied. It is held at the right end of FIG. The second return spring 41 is a compression coil spring and is disposed in a compressed state between the input side partition wall 17 and the discharge side partition wall 18.

When the solenoid 2 of the type in which the moving core 32 and the stator core 37 are opposed in the axial direction as in the first embodiment is used, when the coil 31 is energized and the shaft 5 moves in the ball valve pressing direction, the shaft 5 Does not stop at the position where the step valve 28 is seated on the seat portion 22 a of the discharge valve port 22, and the moving core 32 comes into contact with the stator core 37. That is, the air gap becomes 0 (zero).
When the moving core 32 comes into contact with the stator core 37, the magnetic attractive force α becomes very large, and cannot move in the step valve separation direction during dark current.
Therefore, in the first embodiment, a magnetic blocking means is provided between the moving core 32 and the stator core 37 (air gap) to prevent the moving core 32 and the stator core 37 from coming into contact with each other and being magnetically coupled.
Specifically, the magnetic shielding means of the first embodiment is made of a non-magnetic material (for example, a member excellent in oil resistance, heat resistance, and wear resistance) disposed between the moving core 32 and the stator core 37 facing each other. This is a spacer 42. In the first embodiment, the spacer 42 is provided on the stator core 37 side. However, the spacer 42 may be provided on the moving core 32 side, or may be disposed between the moving core 32 and the stator core 37 without fixing the spacer 42. Just fine.

(3-way solenoid valve operation)
Next, the operation of the three-way solenoid valve will be described.
(B1) In a state where the energization of the coil 31 is turned off (energization off state), the ball valve 4 is seated on the seat portion 21a of the input valve port 21 by the input hydraulic pressure as shown in FIG. And the output chamber 15 is shut off.
In the energized OFF state, the moving core 32 is pressed against the plate 38 by the urging force of the return spring 6, and the step valve 28 of the shaft 5 is separated from the seat portion 22 a of the discharge valve port 22 and discharged from the output chamber 15. The chamber 16 communicates and discharges hydraulic pressure from the output port 12 to the discharge port 13. The air gap in the energized OFF state is defined as d1.

(B2) When the coil 31 is energized, a magnetic attractive force α is generated in the air gap between the moving core 32 and the stator core 37, and the moving core 32 moves in the ball valve pressing direction while pressing the shaft 5.
During the movement of the shaft 5 in the ball valve pressing direction, the pressing shaft 25 contacts the ball valve 4 as shown in FIG. Thus, the air gap when the pressing shaft 25 abuts on the ball valve 4 is d2.
After the pressing shaft 25 comes into contact with the ball valve 4, the pressing shaft 25 lifts the ball valve 4 as the shaft 5 moves. Thereby, the input valve port 21 opens, the input chamber 14 and the output chamber 15 communicate, and the input port 11 and the output port 12 communicate.

(B3) When the shaft 5 further moves in the ball valve pressing direction, the step valve 28 of the shaft 5 is seated on the seat portion 22a of the discharge valve port 22, as shown in FIG. Thus, the air gap when the step valve 28 is seated on the seat portion 22a of the discharge valve port 22 is defined as d3.
When the step valve 28 is seated on the seat portion 22a of the discharge valve port 22, the communication between the output chamber 15 and the discharge chamber 16 is blocked, and the communication between the output port 12 and the discharge port 13 is blocked.
As a result, the hydraulic pressure supplied from the input port 11 is output from the output port 12.

(B4) After the step valve 28 is seated on the seat portion 22a of the discharge valve port 22, the magnetic attractive force α applied to the moving core 32 with the step valve 28 still seated on the seat portion 22a of the discharge valve port 22 Thus, the shaft 5 further moves in the ball valve pressing direction. That is, the discharge-side partition wall 18 is pressed by the step valve 28 and moves into the output chamber 15. Thereby, the ball valve 4 is further lifted than (B3).
Thereafter, as shown in FIG. 4, the moving core 32 contacts the stator core 37 via the spacer 42, and the movement of the shaft 5 in the ball valve pressing direction stops. At this time, the lift amount of the ball valve 4 is maximized. Thus, the air gap when the moving core 32 and the stator core 37 abut via the spacer 42 is d3 ′.

(B5) When energization is stopped, the magnetic attractive force α in the air gap disappears (the slight magnetic attractive force α due to the dark current remains). Then, the shaft 5 has “spring load (combined spring force of the return spring 6 and the second return spring 41)” + “discharge hydraulic pressure (hydraulic pressure received by the step valve 28 in the discharge valve port 22)” + “movable partition wall hydraulic pressure ( In response to “pushback force β3 ′” by “hydraulic pressure received by the discharge-side partition wall 18”, while moving the moving core 32, it moves in the step valve separation direction (side different from the input chamber 14).

(B6) The discharge-side partition wall 18 moves in the step valve separation direction together with the shaft 5, and the position of the air gap d3 shown in FIG. 3 (position where the step valve 28 starts to contact the seat portion 22a of the discharge valve port 22). When the discharge-side partition wall 18 moves to the end, the discharge-side partition wall 18 contacts the valve base 3 in the axial direction. Then, the “movable partition wall hydraulic pressure (hydraulic pressure received by the discharge side partition wall 18)” is received by the valve base 3, and the pushing force received by the shaft 5 is “spring load (spring force of the return spring 6)” + “discharge hydraulic pressure ( The hydraulic pressure received by the step valve 28 in the discharge valve port 22) becomes “pushback force β3”.

(B7) Further, when the shaft 5 moves in the step valve separation direction and the step valve 28 is separated from the seat portion 22a of the discharge valve port 22, the output chamber 15 and the discharge chamber 16 communicate with each other, and the output port 12 Begin to discharge the side oil pressure.
Then, the shaft 5 receives “pushback force β2” by “spring load (spring force of the return spring 6)” + “input hydraulic pressure (load received by the ball valve 4 due to the pressure difference between the input chamber 14 and the output chamber 15)”. While moving the moving core 32, it moves in the step valve separation direction.

(B8) Further, when the shaft 5 moves in the step valve separation direction, the shaft 5 reaches the position of the air gap d2, and the ball valve 4 is seated on the seat portion 21a of the input valve port 21, the input chamber 14 and the output are output. The communication of the chamber 15 is cut off, and the hydraulic pressure of the output port 12 is discharged from the discharge port 13.
Then, the shaft 5 receives “pushback force β1” due to “spring load (spring force of the return spring 6)” and moves in the step valve separation direction while pushing the moving core 32.
Thereafter, the moving core 32 is pressed against the plate 38 and returns to the energization OFF state (B1).

(Force received by shaft 5)
The force received by the shaft 5 changes according to the air gap. The relationship between the force received by the shaft 5 and the air gap is shown in FIGS.
The shaft 5 is displaced between a position where the energization is OFF and a position where the moving core 32 contacts the stator core 37 via the spacer 42.
The displacement of the shaft 5 is as follows: (1) when the power is turned off until the pressing shaft 25 contacts the ball valve 4; (2) the pressing shaft 25 contacts the ball valve 4; Until the seat is seated on the seat portion 22a, (3) the step valve 28 can be divided into three steps from the seating to the seat portion 22a of the discharge valve port 22 to the contact between the moving core 32 and the stator core 37 via the spacer 42. .
The air gap when the energization is OFF is d1, the air gap when the pressing shaft 25 contacts the ball valve 4 is d2, and the air gap when the step valve 28 is seated on the seat portion 22a of the discharge valve port 22 is d3. The air gap when the moving core 32 and the stator core 37 abut via the spacer 42 is d3 ′.

When the shaft 5 is energized, it receives a magnetic attraction force α directed to the left in the figure corresponding to the air gap.
On the other hand, the shaft 5 receives a pushing force β directed in the right direction in the figure by a spring load or hydraulic pressure.
As described above, the push-back force β can be classified as follows according to the displacement position of the shaft 5.
(I) From the time of energization OFF until the pressing shaft 25 comes into contact with the ball valve 4 (d1 to d2), the shaft 5 receives a pushing back force β1 due to “spring load (spring force of the return spring 6)”.
(Ii) The shaft 5 is “spring load (spring force of the return spring 6) until the pressing shaft 25 contacts the ball valve 4 until the step valve 28 is seated on the seat portion 22a of the discharge valve port 22 (d2 to d3). "+" Pushing force β2 by "input hydraulic pressure (load received by ball valve 4 due to pressure difference between input chamber 14 and output chamber 15)" is received.
(Iii) With the step valve 28 seated on the seat 22a of the discharge valve port 22 (d3), the shaft 5 is “spring load (spring force of the return spring 6)” + “discharge hydraulic pressure (output chamber 15 and discharge chamber). The hydraulic pressure received by the step valve 28 due to the pressure difference of 16) ”is received.
(Iii) The step valve 28 abuts against the seat portion 22a of the discharge valve port 22 until the movement of the shaft 5 stops (d3 to d3 ′), the shaft 5 is “spring loaded (return spring 6 and second return spring 41). (Combined spring force)) + "discharge hydraulic pressure (hydraulic pressure received by the step valve 28 in the discharge valve port 22)" + "movable partition wall hydraulic pressure (hydraulic pressure received by the discharge side partition wall 18)".

  The shaft 5 has a resultant force γ of “magnetic attraction force α” + “pushback force β (any of β1, β2, β3, β3 ′)”, and the resultant force γ is positive (α> β). For example, if the resultant force γ is negative (α <β), the shaft 5 moves in the step valve separation direction.

(Setting of air gap d2)
The hydraulic pressure supplied to the input port 11 varies greatly depending on the engine speed and the like. Further, the operating current supplied to the solenoid 2 (specifically, the coil 31) also varies depending on the state of the vehicle.
FIG. 5 shows “magnetic attraction force α” and “pushback force β (β1, β2) when the hydraulic pressure supplied to the input port 11 is maximum (maximum pressure) and the energization current of the solenoid 2 is minimum (minimum operating current). , Β3, β3 ′) ”.
In the relationship of FIG. 5, in order to open the ball valve 4 with the air gap d2 when energized, the “magnetic attraction force α” due to the minimum operating current in the air gap d2 is greater than the “pushback force β2” at the maximum pressure. It needs to be bigger.
That is, the air gap d2 is set to a value such that “magnetic attraction force α”> “push-back force β2” at “maximum pressure and minimum operating current”.

(Setting of the opening diameter of the discharge valve port 22)
On the other hand, in order to seat the step valve 28 on the seat portion 22a of the discharge valve port 22 at the air gap d3 when energized, the “magnetic attraction force α” due to the minimum operating current is changed from the “push-back force” at the maximum pressure. It needs to be larger than “β3”.
That is, the air gap d3 is set to a value such that “magnetic attraction force α”> “push-back force β3” at “maximum pressure and minimum operating current”.
Here, in order to ensure the relationship of α> β3 at the time of “maximum pressure and minimum operating current”, the opening diameter of the discharge valve port 22 is set small as in the prior art 1, and the discharge is performed. The discharge hydraulic pressure received by the step valve 28 in the valve port 22 is provided to be sufficiently small.

(Setting the diameter of the discharge partition 18)
In the energized OFF state, a small amount of magnetic attractive force α is generated in the air gap due to dark current.
FIG. 6 shows “magnetic attraction force α” and “pushback force β (β1, β2, β3, β3) when the hydraulic pressure supplied to the input port 11 is the lowest (minimum pressure) and dark current flows through the solenoid 2. ')'.
In the relationship of FIG. 6, in order to move the shaft 5 in the step valve separation direction by the air gap d3 ′ when the energization is stopped, the minimum pressure “pushback force β3 ′” is set in the air gap d3 ′. It is necessary to make it larger than the “magnetic attraction force α” due to dark current.
That is, the air gap d3 ′ is set to a value such that “magnetic attraction force α” <“pushing force β3 ′” when “the lowest pressure and dark current”.
Here, in order to increase the “pushback force β3 ′”, the diameter of the discharge side partition 18 may be increased. For this reason, the diameter of the discharge-side partition wall 18 is set so that the relationship of α <β3 ′ can be ensured at the time of “minimum pressure and dark current”.

(Description of operation of air gaps d3 to d3 ′)
Next, the operation of the air gaps d3 to d3 ′ will be described with reference to FIGS. 5 to 7 are shown for comparison, and “push-back” in the “three-way solenoid valve with a larger opening diameter (pressure receiving area)” shown in the prior art 2. It shows "force" and "synthetic force".

(Operation at maximum pressure and minimum operating current)
In the range of the air gaps d3 to d3 ′, the step valve 28 of the shaft 5 is seated on the seat portion 22a of the discharge valve port 22, and the discharge side partition wall 18 receives the discharge hydraulic pressure on a large surface. When it rises, “pushback force β3 ′” increases as shown in FIG.
For this reason, if the "push-back force β3 '" increases as the input hydraulic pressure increases (for example, the maximum pressure) and the magnetic attractive force α decreases due to the minimum operating current, α <β3' is established and the step valve is moved away from the seat. The shaft 5 is pushed back. At this time, since the step valve 28 of the shaft 5 is seated on the seat portion 22a of the discharge valve port 22, the discharge valve port 22 is not opened.

When the shaft 5 is pushed back in the step valve separation direction and the discharge side partition wall 18 moves to the position of the air gap d3 (position where the step valve 28 starts to contact the seat portion 22a of the discharge valve port 22), the discharge side partition wall 18 is abutted in the axial direction of the valve base 3, and “movable partition wall hydraulic pressure (hydraulic pressure received by the discharge side partition wall 18)” is received by the valve base 3. As a result, the pushback force received by the shaft 5 is “pushback force” β3 ”.
Since the “pushback force β3” is the hydraulic pressure received by the step valve 28 in the discharge valve port 22 as described above, the opening diameter (pressure receiving area) of the discharge valve port 22 is relatively small as in the prior art 1. By providing, the “pushback force β3” can be kept low. For this reason, even if it is the highest pressure and the lowest operating current, α> β3 is reliably maintained, the step valve 28 is not separated from the discharge valve port 22, and the discharge valve port 22 opens. Does not occur.

(Operation at minimum pressure and dark current)
When the solenoid 2 is switched from the energized state to the energized OFF state and a small amount of magnetic attraction force α is generated in the air gap due to the dark current, as shown in FIG. 6, in the range of the air gaps d3 to d3 ′, the discharge side partition 18 Since the discharge hydraulic pressure is received on a large surface, the discharge side partition wall 18 and the shaft 5 receive a large “pushback force β3 ′”. As a result, α <β3 ′ is surely established, the shaft 5 is pushed back in the step valve separation direction, and the air gap is widened.
In this way, the air gap is widened and the air gap is widened to the position d3, so that the magnetic attractive force α due to the dark current is sufficiently small. As a result, α <β3 can be reliably established, and the shaft 5 can be reliably returned to the stop position.

(Operation at intermediate pressure and minimum operating current)
FIG. 7 shows the relationship between “magnetic attraction force α”, “push-back force β”, and “synthetic force γ” when the input oil pressure is an average pressure (intermediate pressure) and the magnetic attraction force α is reduced by the minimum operating current. Shown in
As shown in FIG. 7, even in the case of an intermediate pressure and a minimum operating current, naturally, α> β3 is surely maintained, and the step valve 28 is not separated from the discharge valve port 22 and is discharged. There is no problem that the valve port 22 opens.

(Effect of Example 1)
As described above, the three-way solenoid valve of the first embodiment is provided so that the discharge-side partition wall 18 can be displaced in the axial direction while the step valve 28 is seated on the seat portion 22a of the discharge valve port 22 during the movement of the shaft 5. As a result, the air gap that determines the lift amount of the ball valve 4 can be reduced from d3 to d3 ′ in the prior art. That is, the lift amount of the ball valve 4 can be increased as compared with the prior art.

In the first embodiment, a spacer 42 is provided between the moving core 32 and the stator core 37 (air gap) to prevent the moving core 32 and the stator core 37 from coming into contact with each other and being magnetically coupled. Accordingly, the air gap d3 ′ is determined by the spacer 42.
Thus, since the air gap d3 ′ can be set by the spacer 42, the air gap d3 can be set extremely small, and the lift amount of the ball valve 4 can be set to the maximum value.

[Modification]
In the above embodiment, the spacer 42 is used as the magnetic blocking means. However, the contact surface of the moving core 32 and the stator core 37 is provided with a convex portion that reduces the contact area and increases the magnetic resistance. The magnetic shielding means may be used.
In the above embodiment, the example in which the solenoid 2 of the type in which the moving core 32 and the stator core 37 face each other in the axial direction is used is shown. However, a solenoid in which the tip of the moving core 32 enters the inside of the cylindrical stator core 37 is used. May be. In this case, since the moving core 32 and the cylindrical stator core 37 cannot contact in the axial direction, the magnetic shielding means can be eliminated.
Although the example which applies this invention to the three-way solenoid valve used for the hydraulic control apparatus of an automatic transmission was shown, you may apply this invention to three-way solenoid valves other than an automatic transmission.

It is sectional drawing and the principal part enlarged view which follow the axial direction of the three-way solenoid valve in the air gap d1 (Example 1). (Example 1) which is sectional drawing in alignment with the axial direction of the three-way solenoid valve in the air gap d2. (Example 1) which is sectional drawing in alignment with the axial direction of the three-way solenoid valve in the air gap d3, and the principal part enlarged view. (Example 1) which is sectional drawing in alignment with the axial direction of the three-way solenoid valve in air gap d3 ', and the principal part enlarged view. 6 is a graph showing the relationship between the air gap and the force received by the shaft at the highest pressure and the lowest operating current (Example 1). It is a graph which shows the relationship between the air gap at the time of the minimum pressure and the time of dark current, and the force which a shaft receives (Example 1). 6 is a graph showing a relationship between an air gap and a force received by a shaft at an intermediate pressure and at a minimum operating current (Example 1). It is sectional drawing which follows the axial direction of a three-way solenoid valve (prior art 1). It is a graph which shows the relationship between the air gap and the force which a shaft receives (prior art 1). It is sectional drawing which follows the axial direction of a three-way solenoid valve (prior art 2). It is a graph which shows the relationship between the air gap and the force which a shaft receives (prior art 2).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Flow path switching part 2 Solenoid 3 Valve base 4 Ball valve 5 Shaft 8 Inner cylinder 11 Input port 12 Output port 13 Discharge port 14 Input chamber 15 Output chamber 16 Discharge chamber 17 Input side partition 18 Discharge side partition 21 Input valve port 21a Input Valve Port Seat 22 Discharge Valve Port 22a Drain Valve Port Seat 25 Press Shaft 28 Step Valve 31 Coil 32 Moving Core 37 Stator Core 42 Spacer (Magnetic Blocking Means)

Claims (3)

A solenoid that includes a coil that generates a magnetic force by energization, and a moving core that is magnetically attracted to one of the axial directions by the magnetic force generated by the coil;
A flow path switching unit disposed on the side where the moving core is magnetically attracted;
In a three-way solenoid valve comprising
The flow path switching unit is
(A) An input port to which fluid is input, an output port for outputting fluid, a discharge port for discharging fluid, an input chamber communicating with the input port, an output chamber communicating with the output port, and the discharge port A communicating discharge chamber is disposed on the axis of the moving core;
The input-side partition that partitions the input chamber and the output chamber, the discharge-side partition that partitions the output chamber and the discharge chamber face each other, an input valve port formed in the input-side partition, and the discharge side A discharge valve port formed in the partition wall, a valve base provided on the axis of the moving core;
(B) a ball valve disposed in the input chamber and seated on the input valve port by fluid pressure in the input chamber;
(C) A push shaft which is inserted from the output chamber side to the inside of the input valve port and can displace the ball valve to the input chamber side is provided at the distal end portion, and the discharge valve from the discharge chamber side. A step valve seated on the seat portion of the mouth and capable of closing the discharge valve mouth is provided in the middle of the axial direction,
A shaft that is slidably supported on the axis of the moving core and is driven from the discharge chamber side to the input chamber side by a magnetic attraction force applied to the moving core;
(D) When the moving core is magnetically attracted toward the ball valve by energization of the coil, and the shaft moves toward the input chamber,
First, the pressing shaft at the tip of the shaft displaces the ball valve to open the input valve port, and to connect the input chamber and the output chamber,
Next, the step valve formed in the middle of the shaft is seated on the seat portion of the discharge valve port, and the communication between the output chamber and the discharge chamber is blocked,
(E) The discharge-side partition is a member separate from the valve base, and is provided movably in the output chamber from a position where the step valve is seated on a seat portion of the discharge valve port,
When the shaft moves in the direction of the input chamber, after the step valve is seated on the seat portion of the discharge valve port during the movement of the shaft, the discharge-side partition wall is pressed by the step valve and the output chamber A three-way solenoid valve characterized by moving to. The three-way solenoid valve according to claim 1,
The solenoid includes a stator core that axially opposes the end of the moving core that is magnetically attracted, and that magnetically attracts the moving core by the magnetic force generated by the coil,
The coil is energized between the moving core and the stator core to prevent the moving core and the stator core from coming into contact with each other and being magnetically coupled when the moving core is closest to the stator core. A three-way solenoid valve provided with a magnetic shut-off means. The three-way solenoid valve according to claim 2,
The three-way solenoid valve according to claim 1, wherein the magnetic shut-off means is a non-magnetic spacer disposed between the moving core and the stator core.

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