JPH027214Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a flow control valve that is disposed between the crankcase or lock cover of an automobile engine and an intake manifold to introduce blow-by gas into the intake manifold.

[Prior art] Blowby gas flow control valve Also called PCV valve, blowby gas containing harmful components that escapes from the combustion chamber of the engine into the crankcase through the gap between the piston and piston ring is controlled by the blowby gas that contains harmful components in the crankcase or rotary cover and intake manifold. A conventional example is shown in Figs. 5 and 6. This is explained by:

FIG. 5 shows the structure of the blow-by gas flow rate control valve 20 (hereinafter abbreviated as control valve 20) when the engine is stopped.

This conventional example is made of synthetic resin except for the coil spring, and is roughly divided into a pipe assembly 10 and an L-shaped body 14. The pipe assembly 10 and the L-shaped body 14 form a housing. And pipe assembly 10 is
A valve 1 consists of a small cylindrical part 2, an inclined part 3, and a large cylindrical part 4, and has a flange part 5 at the lower part of the large cylindrical part 4, and further has an airtight surface 6 (FIG. 6) below it.
is inserted into a pipe 7 which has a valve seat 8 on the crankcase side (not shown) (lower side in the figure) and a locking groove 9 for the coil spring 13 on the other end side. The middle part is a coil spring 13 made of a cylindrical coil whose outer diameter is slightly smaller than the inner diameter of the pipe 7. The small diameter side of the coil spring 13 is in contact with the flange 5 of the valve 1, and the large diameter side is in contact with the locking groove 9 of the pipe 7. The airtight surface 6 of the valve 1 is pressed against the valve seat 8 of the pipe 7 by fitting. That is, the valve 1 is assembled so as to be vertically displaceable by a locking groove 9 provided in the pipe 7 and a coil spring 13 installed between the flange 5 of the valve 1, thereby forming a pipe assembly 10. .

The body 14 includes a joint pipe 15 having an inner wall 16 having approximately the same diameter as the outer wall 11 of the pipe 7;
A stopper part 17 of the valve 7 provided inside the valve 1 is provided, and a flow passage 18 (forming an orifice part 19 described later) is provided with a diameter slightly larger than the diameter of the large cylindrical part 4 of the valve 1. The flow path 18 communicates with an L-shaped junction pipe 21 (leading to an intake manifold, not shown). Then, a stop wall 22 is provided at the position where it is bent into an L shape. Here, the diameter of the large cylindrical portion 4 of the valve 1 is limited to a size that does not obstruct the flow of blow-by gas passing through the pipe 7. The above-described pipe assembly 10 is inserted until the tip of the pipe 7 on the side of the locking groove 9 contacts the stopper portion 17 of the joint pipe 15 of the body 14, and the outer wall 11 of the pipe 7 and the inner wall 16 of the joint pipe 15 are inserted. are hermetically joined to form the control valve 20.

FIG. 6 shows that when the negative pressure in the intake manifold (not shown) is large, such as when the engine is idling, the valve 1 is displaced upward by the negative pressure, exceeding the set load of the coil spring 13. , shows the state in which the upper end of the valve 1 is in contact with the stop wall 22 of the body 14, and the state shown in FIG. When the surface 6 separates from the valve seat 9, an opening 12 is formed in the valve seat 9, and blow-by gas is introduced into the pipe assembly 10 from the crankcase or rocker cover (not shown) side as shown by the arrow.

The blow-by gas flow rate of the control valve 20 varies depending on the opening area depending on the position of the valve 1 in the opening 12 and the orifice portion 19, and the amount flowing through the minimum area is the flow rate on the vertical axis in FIG. That is, the fourth
The figure shows the relationship between the intake manifold negative pressure and the flow rate of the control valve.The small cylindrical part 2 and the inclined part 3 of the valve 1 are located at the orifice part 19, and the intake manifold negative pressure is relatively small. The flow rate is high when . As shown in FIG. 6, when the negative pressure in the intake manifold is large, the tip of the small cylindrical part 2 of the valve 1 is in contact with the stop wall 22 of the body 14, and the large cylindrical part 4 of the valve 1 is at the position of the orifice part 19. In this case, the opening area of the orifice portion 19 is minimized, and the flow rate is constant.

[Problems to be Solved by the Invention] As explained in FIGS. 4 to 6, the control valve 20 is designed to handle negative pressure on the intake manifold side (more precisely, the differential pressure between the intake manifold and the crankcase or rock cover). ) controls the flow rate of blow-by gas inside the control valve, but the large cylindrical part of the valve in particular has a small diameter so as not to create resistance when the blow-by gas passes through. The flow rate is not constant because the part moves sideways, and when the negative pressure inside the intake manifold is large, such as when idling, the large cylindrical part of the valve is located in the orifice part, causing engine vibration or valve chatter. As a result, the areas around parts A and B shown in Fig. 6 wear out, the opening area of the orifice increases, the pressure relationship between the intake manifold and the crankcase or rock cover changes, and the blow-by gas flow rate also changes. This has problems such as poor combustion in the engine and an inability to control the internal pressure of the crankcase.

[Means for solving the problem] In order to solve the above-mentioned problem, a minute gap, which is smaller than the gap between the orifice part of the body flow path and the large cylindrical part of the valve, is created by making the intermediate part of the pipe. A coil spring with an outer diameter slightly smaller than the inner diameter and a large cylindrical part of the valve, in which multiple guides are provided vertically at equal angles and close to the large cylindrical part of the valve. It is.

[Function] A control valve has a valve with multiple guides installed vertically at the bottom of a large cylindrical column, and the middle is installed close to a coil spring whose diameter is slightly smaller than the inner diameter of the pipe.The valve moves vertically inside the housing. During displacement, the inner surface of the coil spring can slide smoothly due to the action of the rollers, and since the inside and outside of the coil spring are close to the pipe and valve guides, the coil spring maintains the same center diameter. The lateral vibration of the valve within the housing is greatly reduced as the valve remains in a compressed state. Furthermore, since there is a guide on the lower side of the large cylinder, even if the large cylinder is located at the orifice, the flow rate will not be modulated.

[Example] An example based on the above invention will be described below with reference to the drawings.

1 to 3 are explanatory drawings of the embodiment, and the only difference from the conventional product is the valve 31,
For convenience of explanation, the same components as the conventional product will be designated by the same numbers and their explanation will be omitted.

FIG. 1 is a longitudinal cross-sectional view for explaining the blow-by gas flow rate control valve 40 (hereinafter referred to as control valve 40) of the present invention, and as shown in FIG. However, the number is not limited to four, and may be three or five.

FIG. 3 shows the relationship between the guide 32 and the coil spring 13. Even when the coil spring 13 is compressed, it moves up and down parallel to the guide 32 while maintaining the slight gap 33. Further, even though only the lower end of the coil spring 13 in FIG. 1 has a small diameter and is smaller than the diameter of the valve 31 including the guide 32, the small diameter portion of the lower end expands and returns to its original size when it comes into contact with the flange 5. Furthermore, the locking groove 9 is provided above the pipe 7, and the large diameter coil spring 13 is fitted only at the upper end. The reason for this is to keep the distance constant. As mentioned above, the product of the present invention differs from the conventional product only in the valve 31, but the second
As shown in FIG. 3, a guide 32 is attached to the large cylindrical portion 4 of the valve 31 below the position facing the flow path so as to have a small gap 33 with the coil spring 13.
By providing and placing them close to each other, the lateral vibration of the valve 31 is limited by the coil spring 13 even in the position of the large cylinder part 4 or the orifice part 19.
There is no contact wear at points A and B in the figure. Further, even if the guide 32 is provided below the large cylindrical portion 4 of the valve 31, the opening area formed by the pipe 7 and the valve 31 is always larger than the opening area at the orifice portion 19, so the flow rate characteristics are not affected. The other configurations and operations are the same as those explained in the prior art section, so their description will be omitted.

[Effects of the invention] As described above, the present invention consists of a small cylindrical part, an inclined part, and a large cylindrical part in a housing in which an inlet opening with a valve seat and an outlet opening with a stopper part are formed. A cylindrical valve having a flange at the lower part of the large cylindrical part and an airtight surface below the cylindrical part is disposed with the airtight surface facing the valve seat, and the flange of the valve and the housing are arranged. A coil spring with an outer diameter slightly smaller than the inner diameter of the pipe is installed between the stopper part and the large cylindrical part of the valve. Since multiple guides are provided in the direction, the vertical displacement of the valve within the housing is smooth, and lateral vibration can be limited to the narrow gap between the inside and outside of the valve, and the large cylindrical part of the valve is located at the orifice. However, the small cylindrical part, the inclined part, and the upper part of the large cylindrical part of the valve do not have the role of guides to support stable vertical movement of the valve, and these may interfere with the orifice part due to vibration. Therefore, wear due to valve chatter does not occur, and the opening area of the orifice does not increase. Furthermore, since the guide is provided below the large cylindrical portion, it does not obstruct the flow of blow-by gas and does not cause flow rate modulation.

[Brief explanation of the drawing]

Fig. 1 is an explanatory longitudinal sectional view of the product of the present invention, Fig. 2 is a cross-sectional view thereof, Fig. 3 is a partially enlarged view of its main parts, Fig. 4 is a flow rate characteristic diagram, and Fig. 5 is a valve. Explanatory longitudinal cross-sectional view of the conventional product when is not operating, No. 6
The figure is an explanatory longitudinal cross-sectional view of the conventional product at maximum valve movement. 1, 31...Valve, 4...Large cylindrical part, 7...
Pipe, 10... Pipe assembly, 13...
Coil spring, 14...Body, 20, 40
... Blow-by gas flow rate control valve, 32 ... Guide, 33 ... Fine gap.

Claims (1)

[Scope of utility model registration request] A cylindrical housing is formed with an inlet opening with a valve seat at one end and an outlet opening with a stop wall at the other end. It has a flange at the bottom of the part,
Further, a cylindrical valve with an airtight surface provided below the valve is disposed so that the airtight surface and the valve seat face each other, and the small cylindrical part is located in the flow path formed in the upper part of the housing. In a blow-by gas flow control valve in which a spring whose middle part has an outer diameter slightly smaller than the inner diameter of the housing is compressed between the flange and the stopper part of the housing, the spring is placed close to the inner circumference of the spring on the lower side of the large cylinder of the valve. A blow-by gas flow rate control valve characterized in that a plurality of guides are provided in the vertical direction and the guides are arranged close to a spring.