JP2511331Y2 - solenoid valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a solenoid valve, and is particularly suitable for a solenoid valve for supplying hydraulic pressure to a variable valve timing system.

(Prior Art) As a prior art relating to the present invention, for example, Japanese Patent Laid-Open No. 60-
There is one disclosed in Japanese Patent No. 95284.

This conventional solenoid valve will be described with reference to FIG. 3. This solenoid valve 70 is used as a fuel injection device, and a housing 71 thereof has a through hole 72 formed in the axial direction. The upper part of the housing 71 in the drawing is inserted into the delivery pipe 74 via the seal ring 73, and the lower part of the housing is inserted in the intake manifold (not shown) via the seal ring 75.

An injection hole 76 is formed in the vicinity of the lower end of the through hole 72 in the drawing, and a ball valve 77 that opens and closes the injection hole 76 is arranged above the injection hole 76. Solenoid means 76 is provided inside the housing 71, and the ball valve 77
Separates from and is seated on the injection hole 76.

Here, because the pressurized fuel is constantly supplied to the through hole 72, when the ball valve 77 is separated from the injection hole 76, the injection hole 76
Fuel is injected from.

(Problem to be Solved by the Invention) However, in the above-described conventional solenoid valve, when the ball valve 77 is seated in the injection hole 76, the through hole 72 is filled with the pressurized fuel. Although the seal ring 73 is provided between the housing 71 and the delivery pipe 74, the pressurized fuel may leak from the seal ring 73 due to deterioration of the seal ring 73 over time.

Therefore, in the present invention, it is a technical problem to prevent the pressurized fluid that has lost its place from leaking to the outside.

[Constitution of device]

(Means for Solving the Problems) The technical means of the present invention taken to solve the above-mentioned technical problems of the present invention include a solenoid valve, a solenoid means, and
A housing fixed to the solenoid means, first, second and third ports formed in the housing, and housed in the housing and driven by the solenoid means to selectively select the first, second and third ports. A valve means for opening and closing the housing, a housing means for housing the housing through a clearance, a first communication passage formed in the housing, and a second communication passage formed in the valve means so as to overlap with the first communication passage. However, the second port and the third port are made to be able to communicate with each other through the clearance, the first communication passage, and the second communication passage.

(Operation) According to the above-described technical means of the present invention, the pressurized fluid that has lost its place in the output port passes through the clearance between the housing and the containing means, the first communication passage, and the second communication passage. Since it can escape to the drain, leakage of the pressurized fluid to the outside can be prevented.

(Embodiment) An embodiment embodying the technical means of the present invention will be described below with reference to the accompanying drawings.

In FIG. 1, the solenoid means 11 of the solenoid valve 10 has the structure described below. First, a coil 13 is wound around the outer circumference of a bobbin 12 formed of a non-magnetic material (for example, resin) in a cylindrical shape, and a fixed iron core 14 is inserted in the through hole 12a of the bobbin 12. A housing 15 formed of a non-magnetic material (for example, resin) is integrally arranged on the bobbin 12, and a connector 16 is formed on a part of the housing 15.

A side yoke 17 is arranged on the outer peripheral portion of the housing 15, and one end of the side yoke 17 is fixed to the fixed iron core 14 by crimping,
The other end is fixed to the yoke 18. A movable iron core 19 is disposed so as to face one end (left end in the figure) of the fixed iron core 14, and a flange portion 20 of a rod 20 made of a non-magnetic material fixed to the movable iron core 19.
A spring 21 is stretched between a and the recess 14a of the fixed iron core 14.

Further, sealing members 22, 23 are provided between the through hole 12a of the bobbin 12 and the fixed iron core 14, and between the bobbin 12 and the yoke 18, respectively.
Are arranged.

Next, the yoke 18 integrally crimps and fixes the housing 25 via the spacer 24.

The housing 25 is formed with an input port (first port) 26, an output port (second port) 27, and a drain port (third port) 28. The housing 25 has a space 25a therein, and a spool valve (valve means) 29 is slidably arranged in the space 25a.

The spool valve 29 has a through hole 29a inside, and the through hole 2
A spring 31 is stretched between the stepped portion of 9a and the retainer 30. The spring 31 urges the spool valve 29 in the direction of abutting the left end of the rod 20 in the figure.
Further, the retainer 30 is supported by a snap ring 32 fixed to the drain port 28. Further, the biasing force of the spring 31 is set smaller than the biasing force of the spring 21.

The first inner peripheral portion 25b of the housing 25 and the first of the spool valve 29
The outer peripheral portion 29b is always engaged regardless of the position of the spool valve 29 sliding, and the input port 26 and the drain port 28 do not communicate with each other.

Either the second inner peripheral portion 25c or the third inner peripheral portion 25d of the housing 25 is adapted to be selectively engaged with the second outer peripheral portion 29c of the spool valve 29. That is, when the solenoid means 11 is operating (the state shown in FIG. 1), the third inner peripheral portion 25d and the second outer peripheral portion 29c are engaged with each other, so that only the input port 26 and the output port 27 are connected. Communicate. On the other hand, when the solenoid means 11 is not operating, the second inner peripheral portion 25c and the second outer peripheral portion 2
By engaging with 9c, output port 27 and drain port
Only 28 communicates with the second communication passage 33 formed in the spool valve 29 and the through hole 29a. Here, the second communication passage 33
Are formed, for example, across four directions as shown.

The yoke 18 and the housing 25 are housed in a housing means (for example, a cylinder head) 34 through a clearance (a minute gap) X over the entire circumference thereof. Where york
A seal member 35 is arranged on the outer circumference of 18.

Further, due to the action of the clearance X, the input port 26 and the drain port 28 communicate with each other only slightly, and the output port 27 and the chamber 35 also communicate with each other very slightly. Also the housing
A first communication passage 36 is formed in 25, and when the first communication passage 36 and the second communication passage 33 overlap due to sliding of the spool valve 29, the chamber 35 and the drain port 28, that is, the output port 27. And the drain port 28 communicate with each other very slightly.

Referring to FIG. 2, the construction of a variable valve timing system 40 in which the solenoid valve 10 of the embodiment of the present invention is controlled to operate will be described.

First, the input port 26 of the solenoid valve 10 communicates with an oil pan 42 (not shown) of an engine via an input communication passage 34a formed in the accommodating means 34 and an oil pump 41, and the input port 26 is constantly connected to the oil pump 41. The generated hydraulic pressure is applied.

Next, the drain port 28 of the solenoid valve 10 communicates with the oil pan 42 via the drain communication passage 34b formed in the housing means 34.

Further, the output port 27 of the solenoid valve 10 communicates with the variable valve timing device 43 via an output communication passage 34c formed in the housing means 34. Since the variable valve timing device 43 has no drain, the hydraulic pressure is supplied or discharged only through the output communication passage 34c. Therefore, if the variable valve timing device 43 is supplied with the storable oil, the oil cannot be received any more.

Further, a current whose supply state is controlled by the control circuit 50 is supplied to the connector 16 of the solenoid valve 10, and the control circuit 50 receives the engine water temperature sensor 51 and the engine load sensor of the engine (not shown) as its input signal. 52 ・ The output signal of the engine speed sensor 53 is input.

The operation of the solenoid valve 10 having the above configuration will be described below.

When an engine (not shown) is started, the oil pump 41 is activated and the pressurized fluid (for example, engine oil) is constantly applied to the input port 26 of the solenoid valve 10.

Since the solenoid valve 10 controls the variable valve timing device 43 to be driven / not driven, the engine water temperature sensor 51 /
When any of the engine load sensor 52 and the engine speed sensor 53 does not meet the condition for operating the variable valve timing device 43, the control circuit 50 does not apply the signal current to the connector 16.

Therefore, the spool valve 29 is spring-loaded through the rod 23.
It is urged to the left in the figure by the urging force of 21. At this time, the first outer peripheral portion 29b of the spool valve 29 is engaged with the first inner peripheral portion 25b of the housing 25, and the second outer peripheral portion 29c is engaged with the second inner peripheral portion 25c. The applied pressurized fluid loses its place. However, since the clearance X is held between the outer circumference of the housing 25 and the inner circumference of the accommodating means 34, the input port 26 and the drain port 28 communicate with each other via this clearance X. Therefore, the pressurized fluid that has lost its place of delivery is discharged to the drain port 28 through this clearance X, and therefore does not leak to other extra places.

At this time, the output port 27 is connected to the second communication passage 33 and the through hole.
It communicates with the drain port 28 via 29a.

Now, engine water temperature sensor 51 and engine load sensor 52
When any of the engine speed sensors 53 meets the condition for operating the variable valve timing device 43, the variable valve timing device 43 is operated and the valve opening / closing timing of the intake / exhaust valve (not shown) of the engine is changed. .

At this time, when the control circuit 50 applies a current to the connector 16, a current flows through the coil 13, so that a magnetic circuit is formed with the fixed iron core 14, the side yoke 17, the yoke 18, the movable iron core 19, and the movable iron core 19 is fixed. Adsorbed to 14.

Therefore, since the rod 20 also moves to the right in the figure together with the movable iron core 19, the spool valve 29 moves to the right in the figure by the urging force of the spring 31. Then, the first outer peripheral portion 29b of the spool valve 29 remains engaged with the first inner peripheral portion 25b of the housing 25, but the second outer peripheral portion 29c disengages from the second inner peripheral portion 25c, and the third inner peripheral portion 25d. Engage with.

Therefore, the communication between the output port 27 and the drain port 28 is cut off, and the input port 26 and the output port 27 communicate with each other.
Therefore, the pressurized fluid is supplied to the variable valve timing device 43 to operate.

As previously mentioned herein, the variable valve timing device 43
Since it does not have a drain, the hydraulic pressure is supplied and discharged only through the output communication passage 34c, so if the variable valve timing device 43 is supplied with oil that can be accommodated, it loses its place in the output port 27. Filled with pressurized fluid.

At this time, the spool valve 29 moves to the right in the drawing, and the first communication passage 36 and the second communication passage 33 overlap. Therefore, the pressurized fluid that has lost its place of filling the output port 27 is the clearance X, the first communication passage 36, the second communication passage 33, and the through hole 29a.
Since it is discharged to the drain port 28 via, it does not leak to other unnecessary places.

After that, when the operation of the variable valve timing device 43 becomes unnecessary, the control circuit 50 terminates the application of the current to the connector 16, so that the movable iron core 19 is moved to the left in the figure by the urging force of the spring 21, and the rod is locked. 23 pushes the spool valve 29 to the left in the drawing, the output port 27 and the drain port 28 communicate with each other, and the input port 26 does not communicate with any place.

As described above, in the present invention, the pressurized fluid that has lost its place of leakage leaks from the clearance X, but the amount of leakage does not affect the variable valve timing device 43 and other components (not shown) of the engine. .

[Effect of device]

As described above in detail, in the present invention, the pressurized fluid that has lost its place in the output port escapes to the drain through the clearance between the housing and the containing means, the first communication passage, and the second communication passage. Therefore, leakage of the pressurized fluid to the outside can be prevented.

[Brief description of drawings]

FIG. 1 shows a sectional view of a solenoid valve 10 according to an embodiment of the present invention. FIG. 2 shows a block diagram of a variable valve timing system 40 whose operation is controlled by the solenoid valve 10 according to FIG. FIG. 3 shows a cross-sectional view of a prior art solenoid valve 70. 10 …… solenoid valve, 11 …… solenoid means, 25 …… housing, 26 …… input port (first port), 27 …… output port (second port), 28 …… drain port (third port), 29: spool valve (valve means), 33: second communication passage, 34: accommodation means, 36: first communication passage, X: clearance.

Claims (1)

(57) [Scope of utility model registration request] 1. A solenoid means, a housing fixed to the solenoid means, and first and second housings formed in the housing.
Second and third ports, valve means housed in the housing and driven by the solenoid means to selectively open and close the first, second and third ports, and the housing through the clearance And a first communication passage formed in the housing, and a second communication passage formed in the valve means so as to overlap with the first communication passage.
The solenoid valve is characterized in that the port and the third port can communicate with each other through the clearance, the first communication passage, and the second communication passage.