JP2581710Y2 - Synthetic resin valve body structure of flow control valve - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a synthetic resin valve structure of a flow control valve provided in, for example, an internal combustion engine.

[0002]

2. Description of the Related Art Conventionally, there is a flow control valve shown in FIG. The flow control valve 41 is disposed in a blow-by gas recirculation device (to be described later) of the engine, and includes a case 42, a valve body 43 slidably housed in the case 42, Spring 44 for urging 43 toward one end
And The case 42 includes an inlet case 46 having an inlet 45 and an outlet case 4 having an outlet hole 47.
8. A valve seat 49 is formed at an opening edge on the inner side of the inflow port 45, and a flow rate control unit 51 that is fitted in the inflow side case 46 and divided by a notch 50 is formed in the outflow side case 48. Is provided. On the other hand, the valve element 43 is loosely inserted into the flow rate control section 51, and the flow rate control section 51
And a tapered valve shaft 52 that varies the orifice diameter between the two and changes the ventilation area in the flow control valve 41. On one end side of the valve shaft 51, a plate-shaped valve portion 53 is integrally formed, and a closing surface 5 which is one end surface of the valve portion 53 is formed.
4 is seated on a valve seat 49 of the inflow case 46. A boss 5 connected to the valve portion 53 is provided on the valve shaft 52.
5 are formed.

On the other hand, in the blow-by gas recirculation system, blow-by gas leaked into a crankcase through a clearance between an engine piston ring and a cylinder wall is guided again to an intake manifold and recombusted, thereby mainly reducing HC. And has a configuration as shown in FIG. That is, the engine 61 is provided with a blow-by passage 64 that connects the inside of the crankcase 62 and the inside of the rocker cover 63, and a recirculation passage 66 is provided between the blow-by passage 64 and the intake manifold 65. Gas recirculation is realized. The flow control valve 41 is provided in a communication portion between the recirculation passage 66 and the intake manifold 65, and connects the outflow side case 46 to the intake manifold 65 side,
It works as follows.

That is, at full load where the amount of blow-by gas generated is large, the urging force of the spring 44 exceeding the negative pressure of the intake manifold 65 moves the valve element 43 toward the inflow side case 46 to increase the ventilation area. (Fig. 4
On the other hand, when the load is small and the amount of blow-by gas generated is small, the valve body 43 is moved out of the case 48 by the negative pressure of the intake manifold 65, which is superior to the biased inflow side of the spring 44.
Side to reduce the ventilation area. Thereby, the flow control valve 41 controls the recirculation amount of the blow-by gas to a favorable state. In addition, the intake manifold 6
In the case where a blow-back (back fire in the carburetor) occurs in the valve body 5, the closing surface 5 of the valve portion 53 of the valve body 43
4 is seated on the valve seat 49 to close the inflow port 45 and prevent the air from returning to the reflux passage 66 (in the direction indicated by the arrow A in FIG. 4). For this reason, a high flatness is required for the closing surface 54 of the valve portion 53 so that blow-back can be prevented when the closing surface 54 is in close contact with the valve seat 49.

On the other hand, recently, there has been a tendency to manufacture the flow control valve 41 with a synthetic resin in order to reduce chattering noise in the flow control valve 41 and to reduce the weight and cost of parts.

[0006]

However, when the flow rate control valve 41 is made of resin, the valve body 43 is made of a relatively inexpensive, heat-resistant and pressure-resistant thermoplastic resin (for example, PBT or the like). In addition, sink occurs on the closing surface 54 of the valve portion 53 after molding. For this reason, the flatness which can prevent the above-mentioned blowback cannot be secured on the closing surface, and after the valve body 43 is formed, the closing surface 54 is cut to secure the required flatness. Had to be applied. As a result, the increase in the number of steps has caused a factor to increase the manufacturing cost of the flow control valve 41.

The present invention has been made in view of such a conventional problem, and has as its object to provide a synthetic resin valve body structure of a flow control valve which does not require cutting after molding.

[0008]

According to the present invention, in order to solve the above-mentioned problems, the present invention is slidably housed inside a case of a flow control valve having an open inlet and extends in the sliding direction. Existing valve shaft, and a valve portion integrally formed on one end side of the valve shaft and having an outer peripheral portion protruding in an outer peripheral direction of the valve shaft,
In a synthetic resin valve body of a flow control valve in which one end surface of the valve portion is seated or separated from a valve seat formed in an opening of the inflow port, the valve body is formed at the one end surface of the valve portion during molding. A hole is provided at the center of the valve, a recess is provided at the other end surface of the outer peripheral portion of the valve portion, and a continuous portion between the valve shaft and the valve portion is formed in a tubular shape by the hole and the recess. Is molded. Further, it is preferable that a convex portion having a protruding end surface that is seated on or separated from the valve seat is formed on the one end surface of the valve portion, and the hole is opened in the protruding end surface.

[0009]

In the above construction, the volume of the resin shrinks when the heated and melted resin is filled into a mold and cooled during molding of the valve body. The valve body molded at this time has a continuous portion between the valve portion and the valve shaft, a hole provided at the center of one end surface of the valve portion, and a concave portion provided at the other end surface of the outer peripheral portion of the valve portion. And is formed into a tubular shape. Therefore, even when the valve shaft contracts in the axial direction and the extending direction, the one end surface of the valve portion, that is, the peripheral surface of the opening of the hole is not affected. In addition, since the outer peripheral portion is made thin by the concave portion, the degree of contraction of the outer peripheral portion is extremely small. Therefore, at the time of curing, the one end face of the valve portion is maintained in the initial state.

[0010] Further, a convex portion having a protruding end surface that is seated on or separated from the valve seat is formed on one end surface of the valve portion, and when the hole is opened in the protruding end surface, the protruding end surface is formed by the protruding end surface. Because there is a step between one end face,
Even if the one end face is distorted, the distortion of the protruding end face is very small as compared with the distortion of the one end face. Therefore, even when the degree of contraction of the valve portion is relatively large and the flatness of the one end face exceeds the allowable range, the flatness of the protruding end face is maintained within the allowable range.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a view showing a valve element 1 used in the flow control valve 41 of FIG. 4 described in the conventional example. The valve element 1 has the same function as the conventional valve element 43 and has It is formed of a resin (refer to FIG. 4 as appropriate). The valve body 1 has a tapered valve shaft 2 and a valve portion 3 integrally formed on one end side of the valve shaft 2, similarly to the valve body 43. The boss part 4 provided with three valve parts is formed.

As shown in FIGS. 2 and 3, the valve portion 3 has a shape in which each vertex of a triangle is cut off, and its outer peripheral portion 5 projects in the outer peripheral direction of the valve shaft 2. Part 3
Is provided on one end face 6 with a projection 7 formed by projecting a portion corresponding to the inscribed circle of the triangle. In addition, valve element 1
When is accommodated in the case 42, the center of the protruding end surface 8 of the convex portion 7 that sits on or separates from the valve seat 49 formed at the opening of the inflow port 45 is provided outside the adjusting portion 4. A hole 9 having an opening diameter d smaller than the diameter D is opened, whereby the protruding end surface 8 is formed in an annular shape (FIG. 2). on the other hand,
The other end surface 10 of the outer peripheral portion 5 of the valve portion 3 has three recesses A formed by two adjacent sides.
Are provided in contact with the outer peripheral surface 12 of the valve shaft 2 (FIG. 3).

The outer peripheral portion 5 is formed to be thin by the concave portions 11..., And the continuous portion B between the adjusting portion 4 and the valve portion 3 is formed by the concave portions 11. It is formed in a tubular shape. Note that dimensions of the hole 9 and recesses 11 ... has a thickness L ₁ between the end surface 6 of the bottom 13 and the valve portion 3 of the recess 11, the outer peripheral surface of the peripheral surface 14 and the valve portion 3 of the recess 11 1
Thickness L ₂ between the 5, the thickness of the connecting portion B is set to be uniform.

In molding the valve body 1 having such a structure, when the resin melted by heating is filled in a mold and cooled, the volume of the resin shrinks. The valve body 1 formed at this time
Is a connecting portion B between the valve portion 3 and the adjusting portion 4, that is, the valve shaft 2.
A hole 9 provided at the center of one end face 6 of the valve portion 3;
Is formed in a tubular shape by a concave portion 11 provided on the other end surface 10 of the outer peripheral portion 5 in contact with the outer peripheral surface 12 of the valve shaft 2. For this reason, even when the valve shaft 2 having a relatively large volume contracts in its axial direction and in the extending direction, the protruding end surface 8 of the convex portion 7 formed on the one end surface 6 of the valve portion 3 is kept in contact with the valve shaft. No distortion due to the effect of volume shrinkage of 2. Further, since the outer peripheral portion 5 is formed in a thin shape by the concave portions 11..., The degree of shrinkage in the outer peripheral portion 5 is extremely small.
No distortion occurs. Therefore, when the valve body 1 is hardened, the protruding end face 8 is maintained in the initial state.

On the other hand, since the protruding end face 8 has a step between itself and the one end face 6, even if the one end face 6 is distorted, the distortion of the protruding end face 8 is less than that of the one end face 6. It will be very slight in comparison. Therefore, the valve section 3
Even if the degree of shrinkage is relatively large and the flatness of the one end face 6 exceeds the allowable range after molding, the flatness of the protruding end face 8 is maintained within the allowable range.

Therefore, in the valve element 1, the required flatness is ensured during molding, so that the valve element 1 (protruding end face 8) is not subjected to cutting work after molding as in the prior art, and the valve element 1 is not cut. The body 1 can be used. As a result, it is possible to prevent an increase in the number of steps when resinizing the flow control valve, and to reduce the manufacturing cost of the flow control valve. In this embodiment, when the valve element 1 is housed in the case of the flow control valve on one end surface 6 of the valve section 3, the valve body 1 is seated on the valve seat formed at the opening of the inflow port opening to the case. Alternatively, the protrusion 7 having the protruding end surface 8 that is separated is shown, but the protrusion 7 is not necessarily provided.

[0017]

As described above, according to the present invention, the flow control valve is housed in the case of the flow control valve having the inlet opening, and is formed integrally with the valve shaft and one end of the valve shaft. A valve portion protruding in the outer peripheral direction of the valve shaft, wherein one end surface of the valve portion is seated or separated from a valve seat formed at the opening of the inflow port. ,
When the valve body is formed, a hole is provided at the center of the one end surface, a recess is provided at the other end surface of the outer peripheral portion, and a continuous portion between a valve shaft and a valve portion is formed with the hole and the recess. And a structure formed into a tube. For this reason, at the time of hardening of the molded valve body, one end surface of the valve portion is not distorted due to volume contraction of the valve shaft and the outer peripheral portion, and the flatness required for the one end surface of the valve body at the time of molding is secured. You.

Therefore, it is possible to eliminate the need for cutting the one end face after molding the valve body. As a result, it is possible to prevent an increase in the number of steps when resinizing the flow control valve, and to prevent the flow control valve from becoming resinous. Can be reduced in manufacturing cost.

Further, a convex portion having a protruding end surface which is seated on or separated from a valve seat is formed on one end surface of the valve portion, and when the hole is opened in the protruding end surface, the protruding end surface is provided with the protruding end surface. Because there is a step between one end face,
Even if one end face is distorted beyond the allowable range, the flatness of the protruding end face is maintained within the allowable range. Therefore, the flatness of the protruding end face can always be ensured within the allowable range, and the cutting of the protruding end face after forming the valve element is not required.

[Brief description of the drawings]

FIG. 1 is a fragmentary sectional view of a valve body showing one embodiment of the present invention.

FIG. 2 is a side view in the direction of arrow A in FIG.

FIG. 3 is a side view in the direction of arrow B in FIG. 1;

FIG. 4 is a diagram showing a conventional example.

FIG. 5 is a schematic configuration diagram of a blow-by gas recirculation device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Valve body 2 Valve shaft 3 Valve part 5 Outer peripheral part 6 One end surface 7 Convex part 8 Projection end surface 9 Hole 10 Other end surface 11 Concave part B Consecutive part

Claims (2)

(57) [Scope of request for utility model registration] 1. A valve shaft which is slidably housed in a case of a flow control valve having an inlet opening and extends in a sliding direction, and is integrally formed on one end side of the valve shaft and has an outer periphery. A valve portion protruding in the outer peripheral direction of the valve shaft, and one end surface of the valve portion is made of synthetic resin for a flow control valve seated or separated from a valve seat formed at an opening of the inflow port. In the valve body, at the time of molding, the valve body is provided with a hole at the center portion of the one end surface of the valve portion, a concave portion is provided at the other end surface of the outer peripheral portion of the valve portion, and the valve shaft and A synthetic resin valve body structure for a flow control valve, wherein a continuous portion with the valve portion is formed into a tubular shape by the hole and the concave portion. 2. The valve device according to claim 1, wherein a convex portion having a protruding end surface that is seated on or separated from the valve seat is formed on the one end surface of the valve portion, and the hole is opened in the protruding end surface. A valve body made of a synthetic resin of the flow control valve described above.