JPS6221191Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a pressure regulating valve for an exhaust gas recirculation device.
More specifically, the present invention relates to the structure of a pressure regulating valve that senses back pressure and controls the exhaust gas recirculation control valve device in an engine back pressure controlled exhaust gas recirculation device.

(Prior Art) Conventionally, this type of pressure regulating valve 1 has an atmospheric chamber 13 and an exhaust gas recirculation control valve device 2 as shown in FIG.
In order to introduce air into the pressure chamber 2B (Fig. 1),
a valve seat 50 having a valve seat 51 and an atmospheric pressure communication passage 52, the valve seat 51 facing a valve portion 32 formed in the center of the diaphragm to form an opening/closing valve;
The valve seat 50 is either formed integrally with the cover 10 which defines the atmospheric chamber 13, or rigidly connected thereto by means of press fitting, welding or the like.

(Problem to be solved by the invention) However, when such a conventional pressure regulating valve 1 is used in an engine system that does not supercharge the intake system, the maximum exhaust pressure applied to the pressure regulating valve is also not high pressure. Therefore, even if a diaphragm molded only from fluorosilicone rubber material, which has exhaust gas resistance and heat resistance, is used, the mechanical strength is sufficient, and since the rigidity is low, the generated force against pressure is stable, which is a problem. However, when used in a system where the intake system is supercharged, such as an engine system equipped with a turbocharger, the maximum fuel pressure is higher than that of the engine system, and this high pressure Since the pressure is applied to the exhaust pressure chamber of the pressure regulating valve, the mechanical strength of the diaphragm is at its upper limit and reliability cannot be guaranteed. Generally speaking, a base material such as Tetron or nylon is used in combination with rubber material to improve the strength of the diaphragm.
Diaphragms that employ this method have higher rigidity and lower pressure sensitivity, so in pressure regulating valves that use such diaphragms, differences (variations) occur in the amount of displacement of individual diaphragms in response to exhaust gas pressure, resulting in opening/closing. This had the disadvantage that the error in the valve pressure point became extremely large, which affected the reliability of the product.

An object of the present invention is to solve such conventional drawbacks and provide a pressure regulating valve for an exhaust gas recirculation device that has stable characteristics and is highly reliable.

(Means for Solving the Problems) The pressure regulating valve of the exhaust gas recirculation system of the present invention has a cover constituting an atmospheric chamber and a valve seat having a valve seat at the tip, which are formed separately. It is characterized by making it possible to freely change the gap between the valve seat and the valve part by threading the connecting part and rotating and adjusting the valve seat.

(Function) According to the pressure regulating valve of the exhaust gas recirculation system of the present invention, after assembling it, the valve seat is rotated with a screwdriver while applying a specified pressure from the nipple, and the valve seat at the tip of the valve seat is pressed into the valve part. Adjust by moving the valve seat up and down until it makes contact,
This allows the pressure point at which the atmospheric communication passage of the pressure regulating valve is opened and closed to be adjusted from the outside.

(Embodiments) Hereinafter, the pressure regulating valve of the exhaust gas recirculation device of the present invention will be described in more detail with reference to preferred embodiments shown in the accompanying drawings.

FIG. 1 schematically shows an exhaust gas recirculation device incorporating a pressure regulating valve according to an embodiment of the present invention. As shown in FIG. 1, the pressure regulating valve operates according to the pressure in the exhaust pressure chamber 2A (exhaust gas pressure intake) of the exhaust gas recirculation control valve device 2, and the pressure regulating valve controls the exhaust gas recirculation. Introducing atmospheric pressure into the pressure chamber 2B of the valve device 2, introducing controlled negative pressure into the pressure chamber 2B from the port 4 provided near the throttle valve of the intake system, and mixing both pressures in the pressure chamber 2B. The operation of the exhaust gas recirculation control valve device 2 is controlled to make the amount of exhaust gas recirculated from the exhaust system of the engine 3 to the intake system proportional to the amount of engine intake air.

This pressure regulating valve is shown in detail in FIG. In the pressure regulating valve according to an embodiment of the present invention shown in FIG. 3, the same or corresponding components as those of the conventional pressure regulating valve shown in FIG. .

Referring to FIG. 3, a pressure regulating valve according to an embodiment of the present invention includes a cover 10 and a housing 20. The cover 10 and the housing 20 have a spring holder 31 and a surface opposite to the exhaust gas pressure receiving surface. The diaphragm valve 30 is connected to a valve part 32 integrally formed in the center by sandwiching the outer edge of the diaphragm valve 30.
An atmospheric chamber 13 and an exhaust gas pressure chamber 22 are formed. Atmospheric air is introduced into the atmospheric chamber 13 through a nipple 12 that is integrally formed with the cover 10 and protrudes from the side.
Exhaust gas pressure is introduced into the exhaust gas pressure chamber 22 from a nipple 21 protruding from a bottom portion integrally molded with the housing 20. The cover 10 also includes a pressure chamber 2B (first
A nipple 11 for guiding the atmosphere is integrally molded into the air chamber 13, and between the nipple 11 and the atmosphere chamber 13,
A valve seat 50 having an atmospheric communication passage 52 and a valve seat 51 facing the valve portion 32 of the diaphragm valve 30 and forming an on-off valve is threaded on the inner surface of the cover 10 and the outer surface of the valve seat 50. It is screwed on at part 57.

A driver support groove 56 is formed on the end surface of the valve seat 50 opposite to the valve seat 51, and the valve seat 50 has a function of moving in a direction perpendicular to the surface of the diaphragm valve 30. An O-ring 53 is disposed above and below the nipple 11 that communicates with the air outlet 54 and protrudes from the cover 10 to prevent air leakage from the air chamber 13 through the threaded portion 57 and air flowing in from the outside. is completely blocked. Furthermore, diaphragm valve 3
Spring holder 31 facing the atmospheric chamber 13 side of 0
A spring 60 is disposed between the cover 10 and the diaphragm valve 30, which generates a force that causes the diaphragm valve 30, which is displaced by the exhaust gas pressure, to be displaced in the opposite direction against the pressure. In addition, the valve seat 5
A bush 55 that closes the atmospheric communication passage 52 is disposed at the upper end of the cylinder 0.

According to the pressure regulating valve of the exhaust gas recirculation system of this embodiment, after assembling the valve seat 50, the valve seat 50 is rotated with a screwdriver or the like while applying a specified pressure from the nipple 21, so that the valve seat 51 at the tip of the valve seat is aligned with the valve part 32. The valve seat 50 is adjusted by vertically displacing the valve seat 50 until it comes into contact with the valve seat 50, thereby adjusting the pressure point at which the atmospheric communication passage of the pressure regulating valve is opened and closed from the outside.

(Effects of the invention) As explained above, according to the pressure regulating valve of the exhaust gas recirculation device of the invention, the rigidity is increased by mixing the base fabric material into the diaphragm valve, and the sensitivity to exhaust pressure is reduced. Even if there are variations in the amount of displacement of the diaphragm, the gap between the valve seat and the valve part can be adjusted freely, so the opening/closing valve pressure characteristics of the atmospheric communication passage can be accurately obtained, improving product reliability.
The conventional exhaust gas pressure control type exhaust gas recirculation control system can be used even in an engine system where the maximum combustion pressure is high.

Furthermore, for products that differ only in the pressure point of the on-off valve, the operating pressure characteristics can be changed by adjusting the valve seat, so it is also possible to make products with different characteristics using the same parts.

[Brief explanation of drawings]

Fig. 1 is a structural explanatory diagram schematically showing an exhaust gas recirculation device incorporating the pressure regulating valve of the present invention, Fig. 2 is a sectional view showing a conventional pressure regulating valve, and Fig. 3 is an embodiment of the present invention. FIG. 3 is a sectional view of such a pressure regulating valve. DESCRIPTION OF SYMBOLS 1...Pressure regulating valve, 2...Exhaust gas recirculation control valve device, 10...Cover, 20...Housing, 30
...Diaphragm valve, 50 ...Valve seat, 5
DESCRIPTION OF SYMBOLS 1... Valve seat, 52... Communication path, 54... Atmospheric outlet, 57... Connection screw portion. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Scope of utility model registration request] a diaphragm valve which is clamped and fixed between the housing and the cover, has an interior partitioned into a pressure chamber communicating with the exhaust pressure chamber of the exhaust gas recirculation control valve device and an atmospheric chamber communicating with the atmosphere, and has a valve portion in the center; A valve comprising a valve seat having an opening formed in an end face and an internal passage formed in an axial direction from the opening, the valve seat being screwed to the cover so as to be able to approach and separate from the valve portion of the diaphragm valve. A pressure regulating valve for an exhaust gas recirculation device, comprising a seat, and a passage communicating the internal passage of the valve seat with a pressure chamber of the exhaust gas recirculation control valve device.