JP4758626B2 - Solenoid valve - Google Patents

Description

  The present invention relates to a solenoid valve applied to fluid flow control.

  In a bleed-type proportional solenoid valve, when the valve is fully opened and the control pressure is finished, oil (fluid) usually flows down, so that the oil consumption flow rate increases and fuel consumption deteriorates.

Therefore, in order to reduce the oil consumption flow rate, a solenoid valve has been developed that stops the oil flow by sealing the inlet with a sphere at the same time as the valve opens. This type of solenoid valve is called a closed-end type, and is disclosed in Patent Documents 1 to 4.
JP-A-7-239053 JP 2001-512866 A JP-A-8-105563 (Patent No. 3219611) JP-T-2001-521661

  However, since this closed-end type solenoid valve is normally used in step AT, it changes to the ON state or OFF state every time it is shifted, so the seal diameter changes due to wear of the sphere and its seal surface, There is concern that the characteristics will change.

  In addition, since the sphere serving as the valve body is always pushed by the solenoid part during solenoid control, the sphere diameter must be less than a certain degree due to the relationship between the source pressure and the suction force of the solenoid part. The tip diameter of the support portion and the hole formed in the surface to be sealed by the sphere serve as an orifice, so the tip diameter of the support portion must be considerably reduced. That is, the relationship of sphere diameter> seal surface forming hole diameter> support portion tip diameter must be satisfied. Thus, there are problems with the strength of the tip of the support part, workability, and handling.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a solenoid valve that maintains characteristics over a long period of time, improves the strength of the tip of the support portion, and is excellent in workability and handleability. There is.

In order to achieve the above object, the present invention adopts the following configuration. That is,
A solenoid unit that obtains a driving force by electromagnetic force, and a valve unit that opens and closes the valve by the driving force of the solenoid unit,
The valve portion opens and closes communication between a first pressure portion that opens and closes communication between a source pressure port that flows in the source pressure and a control pressure port that flows in and out of the control pressure, and communication between the control pressure port and a drain port that discharges the drain. A second valve portion that
Due to the movement of the first valve body of the first valve section and the second valve body of the second valve section connected to the first valve body through a rod by using the driving force of the solenoid section, the first valve body In the solenoid valve in which the opening and closing of the first valve portion and the second valve portion are performed in reverse to each other,
When the first valve portion is closed, the first valve body, which is a sphere, is disposed inside the cylindrical inner wall, which is a cylindrical seal surface that forms a clearance seal with the first valve body. Yes between gap between Jo sealing surface and said cylindrical sealing surface so that there is the inflow of a small amount of fluid from the source pressure port side to the control pressure port side passes between the first valve body Is configured to fit,
The cylindrical sealing surface has a tapered portion as a squeezed portion that expands in the valve opening direction of the first valve body at the valve opening direction side end of the first valve body,
The valve closing of the first valve portion is achieved by the first valve body being moved to the solenoid portion within the cylindrical inner wall and being stored on the cylindrical sealing surface through the tapered portion as the squeezing portion. The first valve body is opened by reducing the inflow of the fluid from the original pressure port to the control pressure port, and the first valve body is opened by the rod pushing the first valve body. Is separated from the cylindrical seal surface through the tapered portion that expands in the valve-opening direction from the state in which the inside of the cylindrical inner wall is housed in the cylindrical seal surface. It is a solenoid valve characterized by being performed by increasing the inflow of the fluid into the port.

  In the first valve portion of the present invention, since the spherical first valve body is housed inside the cylindrical inner wall, a perfect seal cannot be achieved, and a clearance seal is provided to allow the contamination in the fluid to flow. . With such a clearance seal, fluid consumption of the original pressure occurs, but fluid consumption can be suppressed as much as possible by reducing the gap between the first valve body of the sphere and the cylindrical inner wall as much as possible.

  In addition, by using a spherical first valve body as the clearance seal, for example, when the valve body is tilted to be a columnar shape or a conical shape, the shape changes and a galling that contacts the cylindrical inner wall occurs. In the first valve body of the sphere of the present invention, the shape does not change even if tilted, galling does not occur, valve control does not stagnate due to galling, and the first valve body of the sphere and the cylindrical inner wall to the limit where galling occurs The gap can be made as small as possible, and the sealing performance can be improved.

  According to the present invention, the first valve body of the sphere and its sealing surface are not in contact with each other as a clearance seal, so there is no wear, the seal diameter does not change and the characteristics do not change, and the characteristics are maintained over a long period of time. can do.

  Further, since the first valve body of the sphere is housed inside the cylindrical inner wall, it is not necessary to satisfy the relationship of sphere diameter> sealing surface forming hole diameter> support section tip diameter, and it is necessary to reduce the tip diameter of the support section that presses the sphere. If it is smaller than the diameter of the first valve body of the sphere, it can be made thicker in that range, and the strength of the tip of the support portion can be improved. In addition, being able to increase the diameter of the tip of the support portion eliminates the need for fine processing, and is excellent in workability, and is strong and easy to handle.

  Furthermore, in the case of a structure in which the conventional spherical valve body is completely closed, the pressure suddenly drops (rises) before the first valve portion is closed (or immediately after opening), and a shock is given to the hydraulic control system. However, in the present invention, since the first valve body of the sphere is not completely closed, the control pressure characteristic becomes smooth even before the first valve portion is closed (or immediately after opening), and no shock is given to the hydraulic control system. .

  According to this, since the movement of the first valve body of the sphere is gradually narrowed by the tapered portion when the valve is closed, the movement of the first valve body of the sphere becomes smooth and the valve body control is not delayed.

  According to the present invention, the characteristics can be maintained over a long period of time, the strength at the tip of the support portion is improved, and the workability and handleability are excellent.

(First embodiment)
The first embodiment will be described with reference to FIGS. FIG. 1 is a cross-sectional view showing a solenoid valve according to the first embodiment. FIG. 2 is an enlarged view showing an open / close state of the first valve portion by a steel ball of the solenoid valve according to the first embodiment. FIG. 3 is a diagram showing control pressure characteristics and flow characteristics of the solenoid valve according to the first embodiment.

A solenoid valve 1 shown in FIG. 1 is normally closed and is applied to a shift control of an AT unit .

The solenoid valve 1 includes a solenoid unit 2 that obtains driving force by electromagnetic force, and a solenoid unit 2
And a valve portion 3 that opens and closes the valve with the driving force of

  The solenoid unit 2 is surrounded by a case 4, a coil 7 wound around a bobbin 6 containing a sleeve 5, a center post 8 disposed at one end of the coil 7, and a coil coaxial with the center post 8. 7 and a plunger 10 movably guided by the bearing 9 inside. A shim 11 is attached to the center post 8, and a spring 12 is interposed between the shim 11 and the plunger 10, and the plunger 10 is urged by the spring 12 in a direction away from the center post 8. Further, a bracket 13 is provided at a connection portion between the solenoid portion 2 and the valve portion 3 so as to extend laterally.

  In such a solenoid part 2, a magnetic force is generated by energizing the coil 7 such as the center post 8, the case 4, the bracket 13, the sleeve 5, the plunger 10, and the center post 8. A suction force attracted to the center post 8 is generated against the urging force of the spring 12.

  Next, the valve unit 3 includes a first valve unit 15 that opens and closes communication between a source pressure port 13 that allows the source pressure to flow in and a control pressure port 14 that allows the control pressure to flow in and out, and a drain that allows the control pressure port 14 and the drain to drain. And a second valve portion 17 that opens and closes communication with the port 16. These source pressure port 13, control pressure port 14, and drain port 16 are formed in the valve body 18.

  The first valve portion 15 is configured such that a steel ball 19 as a first valve body, which is a spherical body, is housed inside a seal surface 20 that is a cylindrical inner wall, and the steel ball 19 is closed on the solenoid portion 2 side (as illustrated). Done by moving up). As shown in FIG. 2, the diameter of the sealing surface 20 having a cylindrical inner wall is slightly larger than the diameter of the steel ball 19, so that a perfect seal cannot be achieved and the clearance is sufficient to allow the contamination in the oil to flow. It is a seal. With such a clearance seal, oil consumption of the original pressure occurs, but oil consumption can be suppressed as much as possible by reducing the gap between the steel ball 19 and the seal surface 20 as much as possible.

  In addition, by using the steel ball 19 as the clearance seal, for example, when the valve body is inclined to be columnar or conical, the shape changes and a galling that contacts the cylindrical inner wall occurs. Even if the steel ball 19 according to the form is inclined, the diameter of the steel ball 19 does not change and the shape does not change, so that no galling occurs between the sealing surface 20 and the valve body control is not delayed by galling. The gap between the steel ball 19 and the seal surface 20 can be made as small as possible until the limit of occurrence of the seal can be improved.

  As described above, according to the present embodiment, since the steel ball 19 and the seal surface 20 are not in contact with each other as a clearance seal, they do not wear, the seal diameter does not change and the characteristics do not change, and the characteristics are maintained over a long period of time. Can be maintained.

  Further, as shown in FIG. 2, at the end of the seal surface 20 on the valve opening direction side of the steel ball 19, there is a squeezed portion 21 as a tapered portion that expands in the valve opening direction of the steel ball 19. By providing the squeezing part 21, the movement of the steel ball 19 is gradually reduced by the squeezing part 21 when the valve is closed, so that the movement of the steel ball 19 becomes smooth and valve body control is not delayed.

  The second valve portion 17 includes a cylindrical valve body 22 as a second valve body, and a valve seat surface 23 with which the end surface on the side opposite to the plunger 10 of the cylindrical valve body 22 abuts. This is done by moving the columnar valve body 22 to the side opposite to the solenoid 4 (illustrated downward). The columnar valve body 22 is held on the sleeve 5 of the solenoid unit 2 via a bearing 24 so as to contact the plunger 10.

  The steel ball 19 and the cylindrical valve body 22 are connected via a rod 25. The rod 25 has a small-diameter cylindrical portion (support tip) 26 on the steel ball 19 side, and a large-diameter cylindrical portion 27 on the cylindrical valve body 22 side, and the thickness changes in two stages.

  The small-diameter cylindrical portion 26 has a thickness that allows the steel ball 19 to enter the seal surface 20 in which the steel ball 19 is accommodated with a margin, and is for pushing the steel ball 19. Thus, if the small diameter cylindrical part 26 is smaller than the diameter of the steel ball 19, it can be made thick in the range, and strength improvement can be aimed at. In addition, being able to increase the diameter of the small-diameter cylindrical portion 26 eliminates the need for fine processing, and is excellent in workability, and is strong and easy to handle, so that it is excellent in handleability.

  The large-diameter cylindrical portion 27 is smaller than the hole diameter of the valve seat surface 23 that is closed by the cylindrical valve body 22, and is grounded to the end surface of the cylindrical valve body 22 within the inner hole of the valve seat surface 23.

  In such a valve portion 3, when the power to the solenoid portion 2 is not energized, the plunger 10 of the solenoid portion 2 is biased by the spring 12 and is separated from the center post 8 when the power is OFF. 10 is pressed against the valve seat surface 23 to close the valve. Further, the rod 25 is also pushed by the cylindrical valve body 22, and the rod 25 pushes the steel ball 19, so that the steel ball 19 separates from the sealing surface 20 and opens. That is, since the first valve portion 15 is opened and the second valve portion 17 is closed, the source pressure port 13 and the control pressure port 14 communicate with each other, and the control pressure port 14 and the drain port 16 are closed. In addition, the original pressure becomes the control pressure.

  Next, when the solenoid unit 2 is energized, the plunger 10 of the solenoid unit 2 is attracted to the center post 8, so that the cylindrical valve body 22 is separated from the valve seat surface 23 and is opened. Further, since the rod 25 also moves to the solenoid part 2 side (upward in the drawing) following the cylindrical valve body 22, the steel ball 19 gradually approaches the sealing surface 20. That is, since the first valve portion 15 and the second valve portion 17 are opened, all of the source pressure port 13, the control pressure port 14, and the drain port 16 communicate with each other. The fluid pressure is controlled by the control pressure.

  Finally, when the maximum power ON at which the energization of the solenoid unit 2 is maximized, the steel ball 19 is housed in the seal surface 20 and the first valve unit 15 is closed. That is, since the first valve portion 15 is closed and the second valve portion 17 is opened, the source pressure port 13 and the control pressure port 14 are closed, and the control pressure port 14 and the drain port 16 communicate with each other. In addition, the control pressure and the drain are the same pressure. However, since the first valve portion 15 is not completely closed, there is a small amount of inflow from the original pressure.

  As described above, the opening and closing of the first valve portion 15 and the second valve portion 17 are performed in reverse to each other by energizing the solenoid portion 2.

  The above control pressure characteristics and flow characteristics are as shown in FIG. The control pressure characteristic draws a curve in which the control pressure gradually decreases as the current increases. The flow rate characteristic shows a curve in which the flow rate increases with an increase in current until just before the maximum current, and the flow rate suddenly decreases just before the maximum current.

  In particular, as shown in FIG. 3A, the control pressure characteristic includes a small amount of inflow from the original pressure even when the first valve portion 15 is closed. For this reason, the control pressure characteristic is smooth even before the first valve portion 15 is closed, and no shock is given to the hydraulic control system.

(Comparative example)
In order to verify the effect of the solenoid valve 1 according to the first embodiment described above, a conventional solenoid valve 100 was produced. FIG. 4 is a cross-sectional view showing a solenoid valve according to a comparative example. FIG. 5 is an enlarged view showing an open / close state of the first valve portion by a steel ball of a solenoid valve according to a comparative example. FIG. 6 is a diagram showing control pressure characteristics and flow characteristics of a solenoid valve according to a comparative example.

  Since the solenoid part 2 of the solenoid valve 100 according to the comparative example of FIG. 4 and the second valve part 17 of the valve part 3 are the same as those of the solenoid valve according to the first embodiment, description thereof will be omitted. The solenoid valve 100 according to the comparative example is a poppet valve in which the first valve portion 15 of the valve portion 3 is enlarged as shown in FIG. Has a type of valve.

  In the solenoid valve 100 of this comparative example, the seal diameter changes due to wear of the steel ball 19 and its seal surface 28, and the characteristics change due to many changes to the ON state or OFF state. Further, since the relationship of the diameter of the steel ball 19> the diameter of the formation hole 29 of the seal surface 28> the diameter of the support portion tip (small diameter cylindrical portion 30) must be satisfied, the problem of the strength of the support portion tip (small diameter cylindrical portion 30). There are problems of workability and handling.

  Further, in the solenoid valve 100 of the comparative example, as shown in FIG. 6, the control pressure characteristic and the flow rate characteristic are substantially equal to those of the solenoid valve 1 of the first embodiment. However, as shown in FIG. 6B, the control pressure characteristic is completely prevented from flowing in from the original pressure when the first valve portion 15 is closed. For this reason, the control pressure characteristic changes suddenly even before the first valve portion 15 is closed, and gives a shock to the hydraulic control system.

  From the verification of the solenoid valve 100 according to the comparative example, the effect of the solenoid valve 1 according to the first embodiment could be confirmed.

(Second Embodiment)
The second embodiment will be described with reference to FIGS. FIG. 7 is a cross-sectional view showing a solenoid valve according to the second embodiment. FIG. 8 is a diagram showing control pressure characteristics and flow characteristics of the solenoid valve according to the second embodiment.

The solenoid valve 1 ′ according to the present embodiment is different from that of the first embodiment in that it is normally open .

  The solenoid valve 1 ′ includes a solenoid unit 2 that obtains a driving force by an electromagnetic force, and a valve unit 3 that opens and closes the valve by the driving force of the solenoid unit 2.

  The solenoid part 2 is surrounded by the case 4 and has a coil 7 wound around a bobbin 6 containing the sleeve 5 and the center post 8, a center post 8 disposed inside the coil 7 on the valve part 3 side, And a plunger 10 which is guided coaxially with the center post 8 and movably guided by a bearing 9 inside the coil 7. A bearing 24 for guiding the cylindrical valve body 22 is attached to the inside of the center post 8, and a spring 31 is interposed between the bearing 24 and the plunger 10, and between the plunger 10 and the case 4 end. Also, a spring 32 is interposed, and the plunger 10 is urged by the spring 31 in a direction away from the center post 8 (upward in the drawing). Further, a bracket 13 is provided at a connection portion between the solenoid portion 2 and the valve portion 3 so as to extend laterally.

  In such a solenoid part 2, a magnetic force is generated by energizing the coil 7 such as the center post 8, the bracket 13, the case 4, the sleeve 5, the plunger 10, and the center post 8. A suction force attracted to the center post 8 is generated against the biasing force of the spring 31.

  Next, since the valve part 3 is the same as that of 1st Embodiment, it attaches | subjects the same code | symbol and abbreviate | omits description.

  In such a valve portion 3, when the power is OFF when the solenoid portion 2 is not energized, the plunger 10 of the solenoid portion 2 is biased by the spring 31 and is separated from the center post 8. The valve is pulled toward the side 10 and opened away from the valve seat surface 23. Further, the rod 25 is not pushed, and the rod 25 and the steel ball 19 are attracted toward the plunger 10, so that the steel ball 19 is accommodated in the seal surface 20 and is closed. That is, since the first valve portion 15 is closed and the second valve portion 17 is opened, the source pressure port 13 and the control pressure port 14 are closed, and the control pressure port 14 and the drain port 16 communicate with each other. In addition, the control pressure and the drain are the same pressure. However, since the first valve portion 15 is not completely closed, there is a small amount of inflow from the original pressure.

  Next, when the solenoid unit 2 is energized, the plunger 10 of the solenoid unit 2 is attracted to the center post 8, so that the cylindrical valve body 22 approaches the valve seat surface 23. Further, since the rod 25 also moves to the valve portion 3 side (downward in the drawing) following the cylindrical valve body 22, the steel ball 19 is also separated from the sealing surface 20, and the first valve portion 15 is opened. That is, since the first valve portion 15 and the second valve portion 17 are opened, all of the source pressure port 13, the control pressure port 14, and the drain port 16 communicate with each other. The fluid pressure is controlled by the control pressure.

  Finally, when the maximum power ON at which the energization of the solenoid unit 2 is maximized, the cylindrical valve body 22 is pushed by the plunger 10 and comes into contact with the valve seat surface 23 to close the valve. That is, since the first valve portion 15 is opened and the second valve portion 17 is closed, the source pressure port 13 and the control pressure port 14 communicate with each other, and the control pressure port 14 and the drain port 16 are closed. In addition, the original pressure becomes the control pressure.

  The above control pressure characteristic and flow rate characteristic are as shown in FIG. The control pressure characteristic draws a curve in which the control pressure gradually increases as the current increases. The flow rate characteristic shows a curve in which the flow rate suddenly increases as the current increases just before the current is turned off, and gradually decreases when the current is turned off.

  In particular, as shown in FIG. 8C, the control pressure characteristic includes a small amount of inflow from the original pressure even when the first valve portion 15 is closed. For this reason, the control pressure characteristic becomes smooth even immediately after opening the first valve portion 15, and no shock is given to the hydraulic control system.

Sectional drawing which shows the solenoid valve which concerns on 1st Embodiment. The figure which shows opening and closing of the 1st valve part by the steel ball of the solenoid valve which concerns on 1st Embodiment. The figure which shows the control pressure characteristic and flow volume characteristic of the solenoid valve which concern on 1st Embodiment. Sectional drawing which shows the solenoid valve which concerns on a comparative example. The figure which shows opening and closing of the 1st valve part by the steel ball of the solenoid valve which concerns on a comparative example. The figure which shows the control pressure characteristic and flow volume characteristic of the solenoid valve which concern on a comparative example. Sectional drawing which shows the solenoid valve which concerns on 2nd Embodiment. The figure which shows the control pressure characteristic and flow volume characteristic of the solenoid valve which concern on 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Solenoid valve 2 Solenoid part 3 Valve part 7 Coil 8 Center post 10 Plunger 13 Original pressure port 14 Control pressure port 15 1st valve part 16 Drain port 17 2nd valve part 19 Steel ball 20 Sealing surface 21 Squeeze part 22 Cylindrical valve Body 23 Valve seat surface 25 Rod 26 Small diameter cylindrical portion 27 Large diameter cylindrical portion 28 Seal surface 29 Formation hole 30 Small diameter cylindrical portion

Claims (1)

A solenoid unit that obtains a driving force by electromagnetic force, and a valve unit that opens and closes the valve by the driving force of the solenoid unit,
The valve portion opens and closes communication between a first pressure portion that opens and closes communication between a source pressure port that flows in the source pressure and a control pressure port that flows in and out of the control pressure, and communication between the control pressure port and a drain port that discharges the drain. A second valve portion that
Due to the movement of the first valve body of the first valve section and the second valve body of the second valve section connected to the first valve body through a rod by using the driving force of the solenoid section, the first valve body In the solenoid valve in which the opening and closing of the first valve portion and the second valve portion are performed in reverse to each other,
When the first valve portion is closed, the first valve body, which is a sphere, is disposed inside the cylindrical inner wall, which is a cylindrical seal surface that forms a clearance seal with the first valve body. Yes between gap between Jo sealing surface and said cylindrical sealing surface so that there is the inflow of a small amount of fluid from the source pressure port side to the control pressure port side passes between the first valve body Is configured to fit,
The cylindrical sealing surface has a tapered portion as a squeezed portion that expands in the valve opening direction of the first valve body at the valve opening direction side end of the first valve body,
The valve closing of the first valve portion is achieved by the first valve body being moved to the solenoid portion within the cylindrical inner wall and being stored on the cylindrical sealing surface through the tapered portion as the squeezing portion. The first valve body is opened by reducing the inflow of the fluid from the original pressure port to the control pressure port, and the first valve body is opened by the rod pushing the first valve body. Is separated from the cylindrical seal surface through the tapered portion that expands in the valve-opening direction from the state in which the inside of the cylindrical inner wall is housed in the cylindrical seal surface. A solenoid valve, which is performed by increasing the inflow of the fluid into the port.

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