JP2000249234A - Solenoid valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To open a valve without forming a projecting part closing a communicating hole on the valve at opening the valve by forming a curved face shaped or spherical shaped recessed part on the seal face of a valve made of elastic material so as to position to the communicating hole of a seat corresponding to the seal face of a valve. SOLUTION: On the seal face 14a side of a pilot valve 14, a recessed part 14b is formed on the position opposite to a pilot hole 17. The depth of the recess 14b is over 0.35 of the diameter of the pilot hole 17. Further the side section shape of the recess 14b is formed into a curved face shape or spherical shape. The diameter 2r of the recess 14b is set smaller than the seat width of a first seat part 18, namely than the width W from the pilot hole 17 end. Hereby at sealing, even when the recess 14b and the first seal part 18 are deviated in the radial direction, the pilot hole 17 and A-chamber are not communicated to each other through the recess 14b, to insure sealing performance.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a solenoid valve.

[0002]

2. Description of the Related Art Conventionally, for example, compressed natural gas (hereinafter referred to as CNG)
) Is used as fuel for an automobile engine, high-pressure CNG in the cylinder is decompressed by a CNG regulator, and the CNG regulator is provided with an electromagnetic valve for opening and closing the CNG passage. Then, as this solenoid valve, a high-pressure CNG
A multi-stage solenoid valve that supplies CNG from a pilot hole of 0.4 mm or less and then sequentially opens a large-diameter pilot hole is used.

Conventionally, as such a multistage solenoid valve, as shown in FIG. 5, for example, a pilot valve 102 made of a rubber material is provided at the tip of a plunger 101, and the plunger 101 is movable in its axial direction. A main valve 103 is provided, and a pilot hole 104 is formed in the center of the main valve 103.
When the plunger 101 moves in the opening direction from a state where the main valve 103 closes the main hole 105 and the pilot valve 102 closes the pilot hole 104, , The pilot valve 102 is opened and fluid flows out of the pilot hole 104, and then the main valve 10
Japanese Patent Laid-Open Publication No. Hei 8-210546 discloses an apparatus in which the fluid 3 flows out from the main hole 105 by opening 3. And the pilot valve 10 in this structure
2, the entire surface 102a of the surface 102a facing the pilot hole 104 is formed in one plane as shown in FIG.

[0004]

In the pilot valve 102 having the conventional structure shown in FIG. 5, the pressure P _{1 in the} chamber A and the pressure P _{2 in the} chamber B shown in FIG. 6A are P ₁ > P _2. However, when the pressure difference is small, FIG.
State of (a), although normally opened and closed in the state shown in FIG. 6 (b) when the valve is opened, when the pressure P ₁ of the A chamber is considerably higher than the pressure P ₂ of the B chamber (P ₁ »P ₂₎ As shown in FIG. 6C, the pilot hole 10 in the pilot valve 102 is
4 is sucked into the pilot hole 104 and deformed into the projection 102b, and even when the pilot valve 102 is opened, the tip of the projection 102b remains in the position shown in FIG.
As shown in (1), there is a problem that the pilot hole 104 remains closed and the valve is not opened.

Therefore, a high-pressure fuel of 1 MPa or more (C
NG) cannot be applied to a solenoid valve that supplies multi-stages. In order to prevent the deformation of the valve as described above, FIG.
As shown in FIG. 1, a rubber valve body 201 provided with a hard rod 202 at the center thereof (Japanese Patent Application Laid-Open No. 59-89879) can be used. When applied to pilot holes of φ0.4 mm or less,
The rod also has a diameter of 0.4 mm or less, which is difficult to implement in practical use.

Accordingly, an object of the present invention is to solve the above-mentioned problem in a solenoid valve for opening and closing a small-diameter flow hole such as the pilot hole.

[0007]

According to a first aspect of the present invention, there is provided a valve made of an elastic material, wherein a valve having a sealing surface is provided with a corresponding passage hole of a sheet. A curved or spherical depression is formed at the position.

In particular, when the diameter of the flow hole is small, the pressure on the valve side is high, the pressure on the flow hole side is low, and the differential pressure is large, the portion of the valve seal surface located at the flow hole is circulated by the differential pressure. Suction deformation to the hole side. At this time, since the portion of the valve located in the flow hole is formed in a curved or spherical depression, even if the portion is sucked, the portion does not project into the flow hole or does not protrude. Also has a slight protrusion.

Therefore, when the valve opens and moves, the front end of the recess does not remain in the flow hole to close the flow hole, and the recess is reliably separated from the flow hole. The valve is opened.

According to a second aspect of the present invention, in the first aspect, the depth of the depression is 0.35 or more of the diameter of the flow hole. Setting the depth of the dent to such a value is preferable in preventing the dent from protruding from the sealing surface or reducing the amount of protrusion as described above.

According to a third aspect of the present invention, in the first or second aspect, the diameter of the depression is set to be smaller than a width of a sheet portion from an end of a flow hole in the sheet. Is what you do.

In the present invention, even when the recess and the corresponding seat portion are largely displaced in the radial direction at the time of sealing, the communication between the flow hole and the valve-side chamber does not occur due to the recess.

According to a fourth aspect of the present invention, in the first, second or third aspect, the valve and the seat are a pilot valve in a multi-stage solenoid valve and a seat corresponding thereto. It is a feature.

Since the pilot hole of the multi-stage solenoid valve has a very small diameter, it is effective to apply the present invention to such a multi-stage solenoid valve.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described based on an embodiment shown in FIGS. FIG. 1 shows an example of a multi-stage solenoid valve to which the present invention is applied, and shows an example of a three-stage solenoid valve.

In FIG. 1, a body 1 is, for example, CNG.
The regulator body has an inlet 2 for introducing CNG from a CNG cylinder (not shown) and a supply port 3 for supplying CNG to a decompression chamber (not shown) for supplying CNG to the engine. A seat 5 is press-fitted into the body 1 via an O-ring 4, and a solenoid valve 6 is fitted and fixed via an O-ring 7. A coil 9 is wound around the body 8 of the solenoid valve 6, and a stator 10 is arranged inside.
A plunger 11 is slidably disposed in the main body 8, a rear end of the plunger 11 has a predetermined gap with the stator 10, and a spring 12 is interposed between the plunger 11 and the stator 10 by a load of the spring 12. Is the sheet 5
Biased in the direction.

A pin 13 is press-fitted and fixed to the tip of the plunger 11, and a pilot valve 14 is molded and fixed to the center of the distal end surface of the plunger 11. The pilot valve 14 is formed of an elastic material, and is preferably made of nitrile rubber (NBR) or a thermo-flexible resin.

A center valve 15 is fitted on the outer periphery of the front end of the plunger 11 so as to be slidable in the axial direction with respect to the plunger, and the pin 13 is loosely fitted in an axial long hole 16 formed in the center valve 15. I have. Further, at the center of the center valve 15, a pilot hole 17 which is a flow hole is formed so as to penetrate in the axial direction. The pilot hole 17 is formed to have a small diameter, for example, about φ0.4 mm. Further, as shown in FIG. The seat portion 18 is formed to protrude.

A second valve 19 is formed and fixed to the center of the tip of the center valve 15. The second valve 1
9 is made of the same material as the pilot valve 14. The main valve 2 is provided outside the center valve 15.
0 is slidably fitted in the axial direction, and the pin 13 is loosely fitted in the axially long hole 21 formed in the fitting.

A center hole 23 is formed in the center of the main valve 20 so as to penetrate in the axial direction. The center hole 2
A second seat portion 24 protrudes around the center hole 23 on the side of the surface 3 facing the second valve 19.

Further, a third valve 25 is formed and fixed to the distal end surface of the main valve 20 at the outer periphery of the center hole 23. The third valve 25 is also formed of the same material as the pilot valve 14.

A passage 5a is formed in the center of the seat 5 on the body 1 side in an axial direction, and a third seat portion 26 is formed to protrude from an outer peripheral portion of the passage 5a on the third valve 25 side. I have.

The pilot hole 17, the center hole 23,
The passages 5a are sequentially formed with a large diameter in this order. The pilot valve 14 will be described in detail with reference to FIG.

In FIG. 3, a recess 14b is formed at a position facing the pilot hole 17 on the seal surface 14a side of the pilot valve 14. The depth of the recess 14b is 0.35 or more of the diameter of the pilot hole 17. Further, the side cross-sectional shape of the recess 14b is curved or spherical, and when the pilot hole 17 is φ0.4 mm, the radius r of the recess 14b is 0.15 to 0.25 m.
m, and the depth D is preferably 0.14 to 0.2 mm. The most preferred values are r = 0.2 mm, D = 0.
2 mm.

The diameter 2r of the recess 14b is set to be smaller than the sheet width of the first sheet portion 18, that is, the width W from the end of the pilot hole (flow hole) 17. This is because even when the recess 14b and the first seal portion 18 are largely displaced in the radial direction during sealing, the pilot hole 1
This is to prevent the chamber 7 and the A room from communicating with each other by the recess 14b, thereby ensuring the sealing performance.

Next, the operation will be described. FIG. 2A shows a closed state of all valves. In this state, A room is a high positive pressure P ₁ by the high pressure of CNG, B chamber has a pressure P ₂ of the atmospheric pressure, the maximum pressure difference is generated between them, the valves 14 , 19, and 25 as a valve closing load.

When the harness is energized to generate an electromagnetic force in the coil 9, the plunger 11 is moved by the electromagnetic force as shown in FIG.
2A, the pilot valve 14 is separated from the first seat 18 as shown in FIG. 2B, and the first stage valve is opened. At this time, the specifications of the coil 9 are set so that the valve opening load due to the attraction force of the plunger 11 becomes sufficiently large with respect to the valve closing load generated by the product of the differential pressure (P ₁ −P ₂ ) and the diameter of the first seat 18. And the diameter of the first sheet 18 are set.

When the pilot valve 14 opens, CN
G pilot hole 17 from the A chamber, center hole 23, flows into the B chamber through passages 5a, the pressure P ₂ of the B chamber rises to P _3, the pressure difference acting on the center valve 15 to the second sheet portion 24 2C, the second valve 19 of the center valve 15 is pulled by the electromagnetic force as shown in FIG.
As described above, the second-stage valve is opened apart from the second seat portion 24.

[0029] When the pressure in the chamber B by the valve opening is P ₄ rises further, the plunger 11 is moved away from the third valve 25 and the third sheet portion 26 of the main valve 20 retreats until it contacts the stator 10 The third stage is opened.
It becomes fully open.

In the above operation, the pilot valve 14
4 will be described with reference to FIG. If the pressure P ₂ of the pressure P ₁ and the B chamber A chamber is equal to or substantially equal, as shown in FIG. 4 (a), recesses 14b of the pilot valve 14 is not deformed. As described above, the pressures P ₁ and B
When the differential pressure on the pilot pressure is applied to the pilot valve 14 at the time of opening the first stage where the differential pressure of the chamber pressure P ₂ is large, the member of the recess 14 b is sucked toward the pilot hole 17. At this time, the suction protrusion amount of the member of the recess 14b is
Even if the protrusion amount of the conventional structure is as shown in FIG. 6C, the protrusion from the seal surface 14a is obtained by subtracting the depth D of the recess 14b, and the protrusion amount from the seal surface 14a. Is reduced to a slight bulge 14c as shown in FIG.
Does not protrude from

Therefore, when the pilot valve 14 is opened and moved, the member of the recess 14b does not block the pilot hole 17, CNG flows out from the pilot hole 17, and the normal first-stage valve opening is possible. become.

Although the above embodiment is an example in which the present invention is applied to a three-stage solenoid valve, the valve having the recess 14b of the present invention may be applied to a solenoid valve other than the three-stage solenoid valve. The present invention is not limited to the pilot valve, and can be applied to a valve for a seat having a small flow hole diameter.

[0033]

As described above, according to the present invention,
In the case where the diameter of the flow hole is small, the pressure on the valve side is high and the pressure on the flow hole side is low, and the differential pressure is large, a protrusion that closes the flow hole when the valve is opened as in the conventional valve is formed on the valve. Therefore, the valve can be reliably opened.

It is more effective to set the value of the depression as in the second aspect of the present invention. In addition, by setting the diameter of the depression as in the third aspect of the present invention, the sealing performance can be ensured even if the depression and the corresponding seal portion are largely displaced.

Since the pilot hole of the multi-stage solenoid valve has a very small diameter, it is effective to apply the invention of claim 1, 2 or 3 to the multi-stage solenoid valve.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a multi-stage solenoid valve to which the present invention is applied.

FIG. 2 shows the operation of the multi-stage solenoid valve of FIG. 1;
(A) shows the fully closed state, (b) shows the open state of the first stage pilot valve, and (c) shows the open state of the second stage valve.

FIG. 3 is an enlarged vertical sectional view showing a valve and a seat portion in the solenoid valve of the present invention.

4A and 4B are longitudinal sectional views showing the operation in FIG. 3, wherein FIG. 4A shows a state without differential pressure, and FIG. 4B shows a state with differential pressure.

FIG. 5 is a longitudinal sectional view of a main part showing a first conventional structure.

6A and 6B show the operation of the valve in the structure of FIG. 5, wherein FIG. 6A shows a state where there is no differential pressure, FIG. 6B shows an open state where the differential pressure is small, and FIG. Valve closed state,
(D) is a valve open state when the differential pressure is large.

FIG. 7 is a longitudinal sectional view of a main part showing a second conventional structure.

[Explanation of symbols]

 14 Valve 14a Seal surface 14b Recess 17 Flow hole D Recess depth W Seat width

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Naotaka Yoshikawa 1-1, Kyowa-cho, Obu City, Aichi Prefecture Inside Ai San Industry Co., Ltd. (72) Inventor Hiroo Ogasawara 1-1-1, Kyowa-cho, Obu City, Aichi Prefecture 1 Ai San Kogyo Co., Ltd. (72) Inventor Tadao Ino 1-1-1, Kyowa-cho, Obu City, Aichi Prefecture Ai San Kogyo Co., Ltd. (72) Michihiko Masuda 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor F term in the company (reference) 3H052 AA01 BA35 CA01 EA16 3H056 AA01 BB47 CD06 CE03 GG09 GG18 3H106 DA07 DA13 DA23 DA35 DB02 DB12 DB23 DB32 DC02 DC17 DD03 EE05 GB06 KK18

Claims (4)

[Claims] 1. A solenoid valve comprising a valve made of an elastic material, wherein a curved or spherical recess is formed in a sealing surface of the valve at a position corresponding to a flow hole of a sheet. 2. The solenoid valve according to claim 1, wherein the depth of the hollow is 0.35 or more of the diameter of the flow hole. 3. The solenoid valve according to claim 1, wherein a diameter of the recess is set to be smaller than a width of a seat portion from an end of a flow hole in the seat. 4. The solenoid valve according to claim 1, wherein the valve and the seat are a pilot valve in a multi-stage solenoid valve and a seat corresponding to the pilot valve.