JPH0645608Y2 - Ventilator valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a ventilator valve, and more particularly to a ventilator valve suitable for a PCV valve of an engine.

[Conventional technology]

Conventionally, between the engine crankcase and the intake pipe
PVC valve is installed. That is, the blow-by gas from which the combustion gas of the engine has blown into the crankcase cannot be directly discharged to the outside because it contains unburned components. Therefore, it has been conventionally performed that the blow-by gas is sucked into the intake pipe by the intake negative pressure, returned to the combustion chamber again, re-combusted, and then discharged outside together with the exhaust gas.

In this case, inhaling blow-by gas indefinitely
Since it adversely affects the operation of the engine, a PCV valve is installed in the passage that returns blow-by gas to the combustion chamber so that it opens when the crankcase internal pressure rises above a certain level to limit the return amount of blow-by gas. I have to.

Generally, blow-by gas is once introduced into a cylinder head cover, oil is separated here, and then introduced into an intake pipe from a PCV valve attached to the cover. The structure of such a conventional PCV valve will be described with reference to FIG.

In FIG. 2, the PCV valve 1 has a flat and cylindrical shape and is used by attaching it to a cylinder head cover (not shown). The ventilation side housing 2 attached to the cover has a gas consisting of circularly arranged holes. The entrance 4 is open. On the other hand, the discharge side housing 6 is connected with a discharge pipe 8 connected to an exhaust pipe (not shown).

The valve body 10 is a ring-shaped diaphragm having an opening 12 at the center thereof, and is biased toward the closing side by a spring 14. 16 in the drawing is a spring seat for preventing the valve body 10 from being damaged. Conventional PCV valve 1 explained above
When the pressure difference between the crankcase internal pressure and the intake pipe side negative pressure becomes stronger than the elastic force of the spring 14, the valve is opened to perform forced ventilation.

[Problems to be solved by the device]

By the way, the conventional PCV valve described above requires the use of a soft spring to open the valve when the engine speed is low, that is, when the intake negative pressure is low.
Difficult to handle and not suitable for engines with severe vibration. Therefore, since it is necessary to increase the pressure receiving area of the diaphragm in order to operate with a strong spring, there is a problem that the ventilator valve becomes large.

Therefore, the applicant has not provided a return spring that has been used in the past, but simply closes the valve opening only by the elastic force of the diaphragm and provides a contraction hole for bypassing the diaphragm. When the engine rotational speed is high and the flow rate of blow-by gas cannot be covered by the flow rate from the hole, the blow-by gas recirculation device using a valve that opens the valve by opening the diaphragm by increasing the internal pressure is invented. , Japanese Patent Application Laid-Open No. 59-513.

According to the PCV valve of the application, there is an advantage that the blow-by gas can be effectively ventilated even when the engine rotates at a low speed, but there is a problem that the balance between the diaphragm and the contraction hole must be adjusted. There is also a problem that downsizing is difficult unless the number of parts is reduced.

The present invention has been made focusing on the above problems,
A ventilator valve that can be easily opened even with low internal pressure, and can be easily miniaturized by reducing the number of parts, and that operates even if negative pressure acts on the valve like a PCV valve, without being affected by the negative pressure. Is intended to provide.

[Means for Solving the Problems]

The configuration of the ventilator valve of the present invention for achieving the above object is such that a ventilation conduit communicating with a ventilation target container having an internal pressure, a discharge pipe having an open tip, and fitting to each pipe,
A tubular valve body made of an elastic body, a valve opening is provided on the peripheral surface of the ventilation conduit, and a valve seat is provided on the conduit tip side from the valve opening,
A ring-shaped valve surface is formed on the peripheral surface of the valve body and reaches the valve seat.

As the elastic body that can be used for the valve body, for example, an elastic body such as rubber can be used. Further, it is preferable that the width of the ring-shaped valve surface is made as narrow as possible so that the ring-shaped valve surface is closer to the linear contact.

Further, the valve port may be provided with a plurality of holes on the peripheral surface of the ventilation conduit, or grooves may be provided along the peripheral surface. The valve port and the valve surface are usually provided on the same surface, but they may be provided on the peripheral surfaces having different radii.

[Action]

The ventilator valve with the above-mentioned configuration is configured to press the valve surface against the valve seat provided on the peripheral surface of the ventilation conduit to close it by the elastic force of the valve element, and the opening force is the internal pressure acting inside the valve element. And the differential pressure from the atmospheric pressure acting from the outside of the valve element causes the valve element (and hence the valve surface) to open and open.

When a negative pressure acts on the discharge pipe side and a force that reduces the inner diameter of the valve body exposed to the negative pressure acts, the force of pressing the valve seat against the valve seat naturally increases. In such a case, the ventilator valve of the present invention does not affect the force for expanding the valve body as described above. Therefore, by making the width of the surface where the valve surface contacts the valve material narrow, that is, approaching the line contact, the influence of the negative pressure is reduced and the valve can be easily opened.

Therefore, the ventilator valve of the present invention can be effectively used as a PCV valve in which a negative pressure acts on the ventilation conduit side.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings by an embodiment implemented as a PCV valve.

FIG. 1 is a vertical sectional view of a ventilator valve of this embodiment. Ventilator valve 1 ₀ In the figure, the ventilation conduit 20 mounted engages sealingly threaded into the cylinder head cover 18,
It is composed of a valve body 22 and a housing 24 fitted to both an exhaust pipe 8 communicating with an intake pipe of an engine (not shown).

The means for attaching the ventilation conduit 20 to the cylinder head cover 18 was screwed as described above, but other means,
For example, any means such as elastic engagement, press fitting, and adhesion may be used. Further, the means for attaching the housing 24 to the cylinder head cover 18 is a resin-integrally molded product and is provided with a convex groove 26 integrally provided on the cylinder head cover 18 and formed with a bulge portion at the peripheral edge of the housing 24. The fitting portion 28 is provided and elastically engaged so as to be detachable. However, the cylinder head cover 18 and the housing 24
Can be appropriately deformed, for example, made of metal and screwed together.

Now, the plurality of valve openings 30 provided on the peripheral surface of the ventilation conduit 20 are communicated with the cylinder head cover 18 by the gas passage 32, and the valve surface 32 is the conduit on the tip side of the ventilation conduit 20 of the valve orifice 20. It is provided on the circumference of 20.

Further, the valve surface 36 provided on the valve body 22 is formed by integrally extending with the valve body 22 in a ring shape from the inner peripheral surface of the intermediate portion of the valve body 22. Then, the openings at both ends of the valve body 22 are respectively connected to ventilation conduits.
20 and the discharge pipe 8 are fitted, and clips 38 are tightened so that the fitted portion does not come off and blow-by gas does not leak.

The valve chamber 40 formed between the inner peripheral surface of the valve body 22 and the ventilation conduit 20 by extending the valve surface 36 has a large pressure receiving area and the valve body 22 expands due to the internal pressure of the cylinder head cover 18. It is easy to open. Although not shown, the exhaust conduit
20 and the discharge pipe 8 are mechanically fixed so that unnecessary stress does not act on the valve body 22. The atmosphere freely flows through the opening 42 in the housing 24, and atmospheric pressure is applied to the periphery of the valve body 22.

Next will be described the operation of the ventilator valve 1 ₀ of the present embodiment. Since a negative pressure of intake air acts on the exhaust pipe 21 side of the valve body 22, the valve surface 34 becomes a valve seat 32 due to the negative pressure and elasticity of the valve body 22.
Is closed. Now, when the internal pressure of the cylinder head cover 18 rises, the pressure causes the valve body 22 to open, and the valve surface 34
Vent until the pressure drops to a given pressure by pushing open.

In this case, even if the engine (not shown) is rotating at high speed, the intake negative pressure is high, and the valve face 34 presses the valve seat 32 with a strong force, the width of the valve face 22 is narrowed as shown in the figure. Therefore, the blow-by gas slips through by slightly pushing open between the valve seat 34 and the valve surface 36, and the valve can be easily opened. If the width of the valve face 22 is wide, the valve face 34 will open sequentially from the valve opening 30 side so as to separate the valve seat 32, and a stable valve opening operation cannot be performed.

[Effect of device]

As explained above, the ventilator valve of the present invention is
A ventilation conduit that communicates with a ventilation target container having an internal pressure, a discharge pipe with an open tip, and a tubular valve body that is fitted to each of the pipes and is made of an elastic body, and has a peripheral surface of the ventilation conduit. Since a valve opening and a valve seat are provided on the distal end side of the conduit with respect to the valve opening, and a valve surface that extends in a ring shape and reaches the valve seat is formed on the inner peripheral surface of the valve, You can get the effect.

That is, even when the ventilation conduit side has a negative pressure, the force for opening the valve is the elastic force of the valve body and the differential pressure inside and outside the valve body (the external pressure is atmospheric pressure), and the negative pressure is generated by the ring-shaped valve surface. Since the influence of pressure can be suggested as much as possible, the valve can be opened easily, the structure is simple, the number of parts is small, and the assembly, inspection and repair are easy, and it is industrially inexpensive. Can be supplied to.

Therefore, it can be advantageously applied as a PCV valve for an engine.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of a ventilator valve of the present invention, and FIG. 2 is a sectional view of a conventional ventilator valve. 1,1 ₀ ... Ventilator valve, 8 ... Discharge pipe, 18 ... Cylinder head cover, 20 ... Ventilation conduit, 22 ... Valve body, 30 ... Valve mouth, 34
… Valent seat, 36… Valve surface.

Claims (1)

[Scope of utility model registration request] 1. A ventilation conduit communicating with a ventilation target container having an internal pressure, a discharge pipe having an open end, and fitting into each of the pipes,
A tubular valve body made of an elastic body, a valve opening is provided on the peripheral surface of the ventilation conduit, and a valve seat is provided on each of the conduit tip end sides of the valve opening. Out into a shape,
A ventilator valve having a valve surface reaching the valve seat.