JPH0339657Y2 - - Google Patents

Description

[Detailed description of the invention] [Purpose of the invention] "Field of industrial application" This invention relates to a solenoid valve for controlling the flow rate of auxiliary air in an internal combustion engine.

``Prior Art'' Conventional solenoid valves for controlling the flow rate of auxiliary air in internal combustion engines are shown in FIGS. 3a and 3b. That is, a suction pipe member 36 having an air inflow passage chamber 2 is fitted and fixed in the bottom of the case 5 made of a magnetic material, and a seat 41 made of a non-magnetic material and having a valve seat 41a is fitted into the suction pipe member 36. Fixed. An electromagnetic solenoid 22 wound around a bobbin 21 is fixed to the inside of the case 5 via a molding material 23. A core 24 made of a magnetic material is fitted inside the bobbin 21, and the core 24 is made of a magnetic material. It is integrally fixed to the case 5 via a core plate 25. A plunger 4 made of a magnetic material is slidably fitted inside a plunger guide 12 made of a non-magnetic material fixed to the inside of the bobbin 21 so as to face the core 24 . A valve portion 4a is integrally formed as a valve that approaches and separates from the valve seat 41a.

A valve spring 19 is compressed between the adjuster 26 screwed onto the core head and the plunger 4, and constantly biases the plunger 4 and the valve portion 4a in the valve closing direction.

An air outflow passage chamber 3 communicating with the discharge pipe 18 is formed between the suction pipe member 36 and the inner flange portion 5a of the case 5. Note that 27 is a connector, 28 is a terminal to be connected to the thin coil wire, 29 is a filler, and 31, 32, and 33 are all O-rings.

To explain the operation, when the solenoid 22 is not energized, the valve spring 1 is activated as shown in FIG. 3a.
Due to the repulsive force of 9, the plunger 4 and the valve part 4a
is pushed to the left in the figure, and the valve part 4a is pushed to the seat 41.
Since the valve seat 41a is in contact with the valve seat 41a, the flow rate flowing from the inflow passage chamber 2 to the outflow passage chamber 3 is zero. When the solenoid 22 is energized as shown in FIG. 3b,
Since the magnetic circuit φ is formed by the core 24, the plunger 4, the case 5, and the core plate 25, a magnetic attraction force proportional to the electrical input is generated between the core 24 and the plunger 4, and the plunger 4 absorbs the repulsive force of the valve spring 19. The valve portion 4a moves to the right in the figure against the pressure, and the valve portion 4a separates from the valve seat 41a of the seat 41.
Then, air flows from the inflow passage chamber 2 to this valve section 4a.
The air flows through the gap created in the flow control section between the valve seat 41a and the outflow passage chamber 3 and the discharge pipe 18, thus obtaining an air flow rate proportional to the amount of input electricity.

``Problems to be solved by the invention'' In the conventional solenoid valve as described above, the control air flowing through the solenoid valve contains moisture, oil, and dust that cannot be removed by the air cleaner, as well as gasoline vapor, EGR, etc. Gas, blow-by gas, etc. may flow back. Even if these adhere to the valve part of the solenoid valve and the valve seat surface of the seat, during internal combustion engine operation, the valve part is constantly repeatedly coming into contact with and separating from the valve seat of the seat, so these oils These deposits become high in temperature due to the conduction heat of the internal combustion engine, and their viscosity decreases, allowing the plunger and seat to function normally as a solenoid valve without causing adhesion.

However, in such conventional solenoid valves, when the internal combustion engine stops, the valve part and the valve seat remain in pressure contact for a long time due to the repulsive force of the valve spring, and deposits tend to accumulate in the contact area. ,
When these deposits become cold, their viscosity increases, causing the valve part and seat to stick together. Therefore, when the internal combustion engine is next started, it may not function properly as a solenoid valve, resulting in poor idling.

A method to improve this problem is to generate a magnetic attraction force that is greater than the adhesive force caused by deposits such as oil (accompanying this, the spring force that generates the force that counteracts the magnetic attraction force is also strengthened). This can be done by making the solenoid larger or by increasing the current flowing through it, but this is difficult.

Another method is to reduce the contact area between the valve and the seat, which is subject to deposits such as oil. However, with the duty signal applied to the coil,
The valve is vibrating, and the contact surface between the valve and seat is deformed and worn, causing a change in flow rate (the contact surface between the valve and seat may be made of hardened or wear-resistant material, but this is expensive).

This invention was created by focusing on the conventional problems with solenoid valves, and aims to solve the above problems by providing a mechanism that separates the valve and seat when the internal combustion engine is stopped. It is said that

[Structure of the idea]

"Means for Solving the Problems" The present invention provides an inflow passage chamber into the outer frame and an outflow passage chamber to the outside of the outer frame in the outer frame, and a sheet inside the outer frame that partitions the inflow passage chamber and the outflow passage chamber. A valve is provided that moves toward and away from the seat, and a plunger integrally connected to the valve is constantly urged toward the seat by a valve spring.
By energizing a solenoid placed on the outside of the plunger, the plunger opens between the seat and the valve against the force of the valve spring, connects the outflow passage chamber to the intake manifold of the internal combustion engine, and connects the inflow passage chamber to the atmosphere. In the electromagnetic valve connected to the plunger, the seat is attached to an outer frame so as to be movable in the axial direction of the plunger to form a movable seat, and at least a stopper is provided in the outer frame with which the movable seat can move toward the valve side and come into contact with it. A retainer spring is interposed between the movable seat and the valve, and when the internal combustion engine is stopped, the repulsive force of the retainer spring separates the valve from the valve seat of the movable seat.
When the internal combustion engine is running and the solenoid is not energized, the valve seat of the movable seat is brought into contact with the valve, and while maintaining this contact state, the movable seat is brought into contact with the stopper, and the solenoid is energized while the internal combustion engine is running. The solenoid valve is characterized in that when the movable seat is kept in contact with the stopper, the valve is opened by moving the valve against the repulsive force of the valve spring using electromagnetic attraction force. .

``Operation'' When the internal combustion engine is stopped, the inlet passage chamber and the outlet passage chamber on both sides of the movable seat are both at atmospheric pressure and there is no pressure difference, the movable seat is separated from the stopper, and the valve is operated by the repulsive force of the retainer spring. This distances the movable seat from the valve seat.

When the internal combustion engine is operated, air flows from the inflow passage chamber to the intake manifold through the gap between the movable seat and the valve due to the intake manifold negative pressure, but due to the throttling resistance of the gap, air flows between the inflow passage chamber and the outflow passage chamber. A pressure difference is generated between the movable seats and the movable seat moves toward the valve and comes into contact with the valve.

The movable seat and the valve continue to move in the same direction while remaining in contact with each other, and the movable seat contacts the stopper.
At this point, the solenoid is energized to move the plunger against the force of the valve spring, opening the space between the movable seat and the valve. By duty-driving the valve, the flow rate of air passing through the solenoid valve is adjusted.

When the internal combustion engine stops, the negative pressure in the intake manifold disappears, so the differential pressure disappears, the movable seat moves away from the stopper, and the valve follows the movable seat due to the repulsive force of the valve spring, but the valve spring reaches its extension limit position. When approaching , the valve separates from the valve seat of the movable seat due to the repulsive force of the retainer spring.

"Example" This invention will be described below based on the drawings. FIG. 1a shows an embodiment of this invention.

In the figure, the configuration of each part on the right side of the inner flange 5a of the case 5 is the same as that described for the conventional example, so the same reference numerals as in FIG. 3 are given and the explanation will be omitted.

partitioning the inflow passage chamber 2 and the outflow passage chamber 3, and
A movable seat 1 is mounted within an outer frame consisting of a case 5, a suction pipe member 6, etc. so as to be movable in the axial direction of the plunger 4. In order to form the movable seat 1, the movable seat 1 is inserted into a hole in the center of a diaphragm 7 whose peripheral edge is clamped and fixed between the case 5 and the suction pipe member 6 which is fitted and fixed into the case 5 and forms the peripheral wall of the inflow passage chamber 2. The cylindrical portion 1b is fitted. The movable seat 1 has a cylindrical portion 1b whose inner periphery is a through hole 8 with a lip at the left end, and a right end of which is an outer round flange. The inner corner of the outer round flange of the movable seat 1 is a valve seat 1a, and the outer end face is a spring seat 1d.
It is becoming. The diaphragm 7 fitted into the cylindrical part 1b is tightened by a nut 11 screwed into a male thread on the outer periphery of the cylindrical part 1b via a collar 9 fitted into the cylindrical part 1b, so that the movable seat 1 and the diaphragm 7 are It has been concluded. Therefore, the movable seat 1 becomes movable in the axial direction of the plunger 4.

The tip of the plunger guide 12 protrudes into the outflow passage chamber 3, and the protrusion is provided with a control passage 13 through which controlled air can flow in a radial direction. For this purpose, the end portion of the plunger guide 12 has axial cuts arranged in the circumferential direction as shown in FIG.

The tip of the plunger guide 12 is a stopper 14 against which the movable seat 1 can come into contact.
The stopper may be constructed by fixing another member to the case 5, for example. In this embodiment, the movable seat 1
An offset spring 15 is inserted between the spring seat 1d and the inner flange 5a of the case 5 to bias the movable seat 1 away from the stopper portion 14. The movable seat 1 can easily move away from the stopper part 14 provided at the tip of the plunger guide 12. This offset spring 15 can be omitted when the restoring force of the diaphragm 7 or a bellows replacing it, or the repulsive force of the valve spring 19 or retainer spring 17 is strong.

A retainer spring 17 is inserted between the lip protruding from the through hole 8 side of the cylindrical portion 1b of the movable seat 1 and the valve portion 16 of the plunger 4.
The retainer spring 17 is controlled by the restoring force of the diaphragm and the valve spring 1 as shown in Figure 1a.
9. When the movable seat 1 moves to the left due to the repulsive force of the retainer spring 17 and/or the repulsive force of the offset spring 15, the plunger 4 follows the movable seat 1 due to the repulsive force of the valve spring 19, but this following is restricted. This is a spring for separating the valve portion 16 from the valve seat 1c on the extension side of the valve spring 19 and keeping the valve at a constant position.

Next, I will explain the effect.

When the internal combustion engine is stopped, both sides of the movable seat 1 supported by the diaphragm 7 are at atmospheric pressure and there is no differential pressure, resulting in the state shown in FIG. 1a. In the figure, the distance between the movable seat 1 and the stopper part 14 is greater than the distance m in the axial direction between the valve seat 1a of the movable seat 1 and the valve part 16, and the flow control part between the valve seat 1a and the valve part 16 is open. ing.

In the case of this embodiment, the offset spring 15,
Retainer spring 17, valve spring 19
The characteristics of the diaphragm 7 and the diaphragm 7 are balanced so as to satisfy the above conditions, and the spring characteristics are selected so as to perform the following operation.

When the internal combustion engine is operated and negative pressure is generated in the intake manifold, fluid flows from the inflow passage chamber 2 side to the outflow passage chamber 3 side after being throttled by the flow control section between the valve seat 1a and the valve section 16. A differential pressure is generated on both sides of the movable seat 1 supported by the offset spring 1.
5. Compress the retainer spring 17 and move to the right,
First, the valve seat 1a comes into contact with the valve part 16, and then the movable seat 1 moves to the right while compressing the valve spring 19 via the plunger 4, and the movable seat 1 moves to the right while compressing the valve spring 19 through the plunger 4.
It comes into contact with and stops (state shown in Figure 1b).

In this state, the intake air amount of the internal combustion engine is controlled by the duty control of the solenoid 22 as shown in the conventional example (FIG. 1c).

When the internal combustion engine stops and the pressure in the intake manifold becomes atmospheric pressure, the differential pressure on both sides of the movable seat 1 supported by the diaphragm 7 disappears, so the movable seat 1 is affected by the restoring force of the diaphragm 7, the valve spring 19, and the retainer spring. The valve part 16 moves away from the stopper part 14 due to the repulsive force of the valve spring 17 and/or the repulsive force of the offset spring 15, and the valve part 16 follows the movable seat 1 due to the repulsive force of the valve spring 19, but the expansion of the valve spring 19 When the limit position is approached, the valve portion 16 separates from the valve seat 1a of the movable seat 1 due to the repulsive force of the retainer spring 17, opening the flow control portion.

In the above embodiment, the offset spring 15 is provided in order to reliably separate the movable seat 1 from the stopper portion 14 when the internal combustion engine is stopped. offset spring 1 by appropriately determining the strength etc.
You can also eliminate 5. As is clear from the explanation of the above operation, during operation of the internal combustion engine, for example, vibrations occur when the plunger 4 operates during duty control of the solenoid valve.
It is preferable that the pressure-receiving areas of the diaphragm 7 and the movable seat 1 are made sufficiently large so that the movable seat 1 and the stopper portion 14 are pressed against each other and do not come apart even if a force due to vibrations is applied while the vehicle is running.

In the above embodiment, a diaphragm is used to partition the inflow passage chamber and the outflow passage chamber and to hold the movable seat movably in the axial direction, but a bellows may be used instead of the diaphragm. Alternatively, the movable seat may be slid in the axial direction within the case in a piston type manner.

[Effect of idea]

The present invention provides a movable seat by attaching the seat within the outer frame so that it can move in the axial direction of the plunger, and at least a stopper is provided within the outer frame with which the movable seat can move toward the valve side and come into contact with the movable seat. A retainer spring is inserted between the valve and
When the internal combustion engine is stopped, the repulsive force of the retainer spring separates the valve from the valve seat on the movable seat, and when the internal combustion engine is running and the solenoid is not energized, the valve seat on the movable seat comes into contact with the valve and The seat is brought into contact with the stopper while maintaining the contact state, and when the solenoid is energized while the internal combustion engine is operating, the valve is moved by the electromagnetic attraction force against the repulsion of the valve spring while the movable seat is kept in contact with the stopper. Since the valve is opened by moving it against force, the valve seat of the flow control section,
This has the effect of preventing the sticking phenomenon caused by viscous substances adhering to the valve.

Further, if the movable seat is always biased in the direction away from the stopper by the offset spring, there is an effect that the movable seat can be reliably separated from the stopper portion when the internal combustion engine is stopped.

[Brief explanation of drawings]

1a, 1b, and 1c are longitudinal sectional views of the embodiment of the present invention, and FIG. 2 is a perspective view of the plunger guide in FIGS. 1a, 1b, and 1c, Third
Figures a and 3b are longitudinal sectional views of the conventional example. DESCRIPTION OF SYMBOLS 1... Movable seat, 1a... Valve seat, 1b... Cylindrical part, 1d... Spring seat, 2... Inflow passage chamber, 3...
...Outflow passage chamber, 4...Plunger, 5...Case, 5a...Inner flange portion, 6...Suction pipe member, 7...Diaphragm, 8...Through hole, 9...
Collar, 11... Nut, 12... Plunger guide, 13... Control flow path, 14... Stopper section,
15... Offset spring, 16... Valve section, 17... Retainer spring, 18... Discharge pipe, 19... Valve spring, 21... Bobbin, 22... Solenoid, 23... Mold material, 24... Core, 25... Core plate, 26
... Adjuster, 27 ... Connector, 28 ... Terminal, 29 ... Filler, 31, 32, 33 ... O-ring, 36 ... Suction pipe member, 41 ... Seat, 41a ... Valve seat.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. An inflow passage chamber into the outer frame and an outflow passage chamber to the outside of the outer frame are provided in the outer frame, and a sheet separating the inflow passage chamber and the outflow passage chamber within the outer frame and a sheet separated from the sheet. A plunger that is integrally connected to the valve is always urged toward the seat side by a valve spring, and a solenoid placed on the outside of the plunger is energized to move the plunger between the seat and the valve against the force of the valve spring. In a solenoid valve which is configured to open and whose outflow passage chamber is connected to an intake manifold of an internal combustion engine and whose inflow passage chamber is connected to the atmosphere side, the seat is installed within an outer frame so as to be movable in the direction of a plunger axis to form a movable seat; At least, a stopper is provided in the outer frame with which the movable seat can move toward the valve and come into contact with the movable seat, and a retainer spring is interposed between the movable seat and the valve. The valve is separated from the valve seat of the movable seat by force, and when the internal combustion engine is running and the solenoid is not energized, the valve seat of the movable seat is brought into contact with the valve, and the movable seat is held in contact with the valve. When the solenoid is brought into contact with the stopper and the solenoid is energized while the internal combustion engine is operating, the valve is moved by electromagnetic attraction force against the repulsive force of the valve spring while keeping the movable seat in contact with the stopper. A solenoid valve characterized by being designed to open. 2. The solenoid valve according to claim 1, wherein the movable seat is always urged in a direction away from the stopper by an offset spring.