WO2013179750A1

WO2013179750A1 - Valve device and secondary air introduction device

Info

Publication number: WO2013179750A1
Application number: PCT/JP2013/059055
Authority: WO
Inventors: 信東姜; 仁中尾
Original assignee: イーグル工業株式会社
Priority date: 2012-05-31
Filing date: 2013-03-27
Publication date: 2013-12-05
Also published as: CN104024597A; JPWO2013179750A1; JP6031101B2; CN104024597B

Abstract

[Problem] To provide: a secondary air introduction device configured so that after-burn is easily and effectively prevented and so that a reed valve can be easily cooled; and a valve device used for the secondary air introduction device. [Solution] Depending on the axial position of a drive rod (30) driven by a diaphragm (20), a shutoff valve body (40) is located at a position (fully open position) at which a connection passage (10) within a casing (4) is fully open, a position (fully closed position) at which the connection passage (10) is fully closed, or a position (small-amount-of-flow position) at which the primary opening (10a) of the connection passage (10) is closed and the secondary opening (10b) thereof is not closed.

Description

Valve device and secondary air introduction device

The present invention relates to, for example, a secondary air introducing device for exhaust gas purification measures of a gasoline engine and a valve device used therefor.

2. Description of the Related Art A secondary air introduction device that supplies secondary air into exhaust gas and reburns unburned components contained in the exhaust gas is known as a countermeasure for exhaust gas purification of gasoline engines. In the valve device used in such a secondary air introduction device, the reed valve is opened using the pulsation of the exhaust gas flow in the exhaust system to supply the secondary air.

In the conventional secondary air introduction device, when there is a possibility of overheating of the exhaust system due to the supply of secondary air, such as during high-speed and high-load operation, regardless of the pulsation of the exhaust gas flow, The secondary air is not supplied. However, if no secondary air is supplied in this way, there will be no cooling effect due to the flow of secondary air, and the reed valve will be overheated due to the conduction and radiation of exhaust heat, resulting in poor durability, and emissions. It gets worse.

Therefore, as shown in Patent Document 1 below, in order to prevent the reed valve from overheating, it has been proposed to provide a small hole through which a small amount of air is constantly flowing in the direction of the reed valve.

However, such a conventional device is convenient for cooling the reed valve because air is constantly flowing even in a small amount, but in the situation where so-called afterburn is likely to occur, afterburn is effectively prevented. It was difficult to do.

Japanese Utility Model Publication No.57-17050

The present invention has been made in view of such a situation, and its object is to easily prevent afterburning and to easily cool the reed valve, and a valve device used therefor And to provide.

In order to achieve the above object, a valve device according to the present invention comprises:
An inlet port into which the main fluid is introduced, an outlet port through which the main fluid is discharged, and a casing having a communication flow path connecting the inlet port and the outlet port;
A reed valve portion provided on the outlet port side of the communication flow path inside the casing;
A valve device having a shut valve portion provided on the inlet port side of the communication flow path inside the casing,
The shut valve portion is
A drive rod having one end connected to the diaphragm and movable in the axial direction according to the pressure of the pressure chamber partitioned by the diaphragm;
A shut valve body which is fixed to the rod and moves in the axial direction together with the rod, and the position where the shut valve body fully opens the communication flow path according to the axial position of the drive rod (fully open position). ), A position where the communication flow path is fully closed (fully closed position), and a position where the main flow path of the communication flow paths is closed but the sub flow path is not closed (small flow position). It has become.

The valve device according to the present invention can be suitably used as a secondary air introduction device for exhaust gas purification measures. That is, when a relatively large amount of secondary air (an example of the main fluid) is sent from the outlet port to the exhaust gas system to promote exhaust gas purification, the drive rod is moved in the axial direction to fully open the shut valve body. To position.

Also, when there is a high possibility of afterburn in the exhaust system, the drive rod is moved in the axial direction to bring the shut valve body into the fully closed position. As a result, the supply of air to the exhaust system is completely shut off, and the possibility of afterburning can be greatly reduced. Further, backflow from the exhaust system to the valve device can also be prevented.

Furthermore, if there is a possibility that afterburn may occur in the exhaust system, but the possibility is low, or if the temperature of the reed valve exceeds the set temperature, the drive rod is moved in the axial direction to move the shut valve body. Set to a small distribution position. This makes it possible to flow a small amount of air in the direction of the reed valve, and it is easy to prevent overheating of the reed valve.

Inside the casing, in the middle of the communication flow path from the inlet port to the reed valve part, a main opening constituting the main flow path and an opening area smaller than the main opening are the sub flow path May be provided.

Preferably, inside the casing,
A first valve seat in which the shut valve main body abuts and the communication flow path is fully closed at a position where the drive rod is moved to the inlet port side along the axial direction to the maximum extent;
A second valve seat that is in contact with the shut valve main body and closes the main flow path of the main opening at a position where the drive rod has moved to the maximum pressure chamber side along the axial direction; Yes.

Preferably, in a position where the shut valve main body abuts on the second valve seat, a fluid flow from the inlet port to the lead portion is allowed through the sub flow path of the sub opening. The second valve seat may be formed outside the main opening.

FIG. 1A is a schematic cross-sectional view of a valve device according to an embodiment of the present invention, showing a fully open position of the shut valve. FIG. 1B shows a fully closed fully opened position of the shut valve main body in the valve device shown in FIG. 1A. FIG. 1C shows a small flow position of the shut valve body in the valve device shown in FIG. 1A. It is a schematic sectional drawing of the valve apparatus which concerns on one Embodiment of this invention, and shows the fully closed position of a shut valve main body. FIG. 2 shows a secondary air introduction device in which the valve device shown in FIG. 1A is used.

Hereinafter, the present invention will be described based on embodiments shown in the drawings.
The valve device 2 shown in FIGS. 1A to 1C is used as a secondary air introduction device 100 for purifying exhaust gas in the exhaust system pipe 64 of the gasoline engine 60 shown in FIG. An intake system pipe 62 is connected to an intake port 61 of an engine 60 mounted on a vehicle or the like, and an exhaust system pipe 64 is connected to the exhaust port 63.

The valve device 2 has an inlet port 6 and an outlet port 8, and the outlet port 8 is connected to an exhaust system pipe 64 through a secondary air supply pipe 70. The outside air purified by an air cleaner (not shown) is introduced into the valve device 2 from the inlet port 6, and the valve operation of the valve device 2 causes the outlet port 8 according to the exhaust pulsation in the exhaust system pipe 64. The secondary air is selectively supplied into the exhaust system pipe 64 through the through hole.

As shown in FIGS. 1A to 1C, the valve device 2 has a casing 4 that internally forms a communication flow path 10 extending from the inlet port 6 to the outlet port 8. The casing 4 includes a casing main body 4a having a communication channel 10 formed therein, an inlet port cover 4b that is attached to the casing main body 4a and forms the inlet port 6, and an outlet port cover 4c that forms the outlet port 8. And a pressure chamber cover 4d constituting a pressure chamber 14 which is distinguished from the communication flow path 10.

In this embodiment, the communication channel 10 is provided so that the axis of the inlet port 6 and the axis of the outlet port 8 are substantially orthogonal. A reed valve portion 12 is provided in the vicinity of a connection portion where the outlet port cover 4c constituting the outlet port 8 is attached to the casing body 4a. In the communication flow path 10 between the reed valve portion 12 and the inlet port 6, A shut valve portion 16 is provided.

The reed valve portion 12 opens according to the pulsation of the exhaust gas flow in the exhaust system pipe 64 shown in FIG. 2, and the secondary air taken in from the inlet port 6 passes through the outlet port 8 and the secondary air supply pipe 70 to the exhaust system. Supply to the pipe 64. The shut valve portion 16 will be described later.

Inside the casing body 4a, a partition wall 4f for forming the main opening 10a and the sub-opening 10b is formed in the middle of the connecting flow path 10 from the inlet port 6 to the outlet port 8. The sub-opening 10b formed in the partition wall 4f has an opening area that is 1/28 to 1/34 of the opening area of the main opening 10a, and is sufficiently smaller than the main opening 10a.

The center of the main opening 10a substantially coincides with the axis of the drive rod 30 and also substantially coincides with the axis of the inlet port 6, and the drive rod 30 is disposed inside the communication channel 10 including the main opening 10a. Is mounted by a bearing 32 so as to be movable in the axial direction. The bearing 32 is fixed to a partition wall 4e provided integrally within the casing body 4a. The partition wall 4e partitions the pressure chamber 14 and the communication channel 10.

The central portion of the disc-shaped diaphragm 20 is fixed to the first end portion 30 a in the axial direction of the drive rod 30 together with the central portions of the pair of disc-shaped retainers 18 that sandwich the diaphragm 20. The outer edge of the diaphragm 20 is fixed to a connecting portion where the pressure chamber cover 4d is attached to the upper end of the casing body 4a. The diaphragm 20 separates the pressure chamber 14 into a first pressure chamber 14a and a second pressure chamber 14b. It is.

A connecting pipe 16 is connected to the pressure chamber cover 4d provided so as to cover the first pressure chamber 14a. A throttle hole 18 is formed at the tip of the connecting pipe 16. The throttle hole 18 of the connection pipe communicates with the intake system pipe 62 shown in FIG. 2 through a pipe (not shown), and the internal pressure of the intake system pipe 62 is introduced into the first pressure chamber 14a, and the second pressure Due to the pressure difference from the chamber 14b, the diaphragm 20 is deformed as shown in FIGS. 1A and 1B, and the drive rod 30 is moved in the axial direction.

The throttle hole 18 may be connected to a fluid pressure control device or the like instead of the intake system pipe 62 shown in FIG. The second pressure chamber 14b is a sealed space in the present embodiment, but may be communicated with atmospheric pressure.

As shown in FIGS. 1A to 1C, a central portion of a disc-shaped shut valve main body 40 constituting the shut valve portion 16 is fixed to the second end portion 30b which is the lower end of the drive rod 30. The shut valve main body 40 is fixed to the second end 30b of the drive rod 30 by a pair of retainers 41, and the lower end of the coiled spring 34 is in contact with the upper retainer 41. The upper end of the spring 34 is in contact with the lower surface of the partition wall 4e of the casing body 4a, and the spring force of the spring 34 causes the valve body 40 to move downward together with the drive rod 30 in the axial direction relative to the casing body 4a. It can be pressed.

A ring-shaped first convex portion 42 is formed on the outer peripheral side lower surface of the valve body 40. As shown in FIG. 1B, when the pressure in the first pressure chamber 14a is maximized compared to the pressure in the second pressure chamber 14b, and the drive rod 30 is moved to the lowest end position in the axial direction, The ring-shaped first convex portion 42 of the valve body 40 is in pressure contact with the first valve seat 52 formed on the inner surface of the inlet port cover 4b so as to completely block the communication between the inlet port 6 and the communication flow path 10. It has become.

A ring-shaped second convex portion 44 is formed on the upper surface on the outer peripheral side of the valve body 40. As shown in FIG. 1C, in a state where the pressure in the first pressure chamber 14a is maximally smaller than the pressure in the second pressure chamber 14b and the drive rod 30 is moved to the uppermost end position in the axial direction, The ring-shaped second convex portion 44 of the valve body 40 is in pressure contact with the second valve seat 54 formed on the lower surface of the partition wall 4f constituting the main opening 10a described above, and closes the main flow path of the main opening 10a. It is like that. However, in this state, the sub-opening 10b formed in the partition wall 4f is formed outside the main opening 10a (and outside the valve main body 40). Communication of the communication flow path 10 from the inlet port 6 toward the reed valve 12 is ensured through the portion 10b.

As shown in FIG. 1A, in the state where the pressures of the first pressure chamber 14a and the second pressure chamber 14b are balanced, the valve body 40 of the drive rod 30 connected to the diaphragm 20 has the first valve seat 52 and It is located at an intermediate position with respect to the second valve seat 54. Therefore, the valve body 40 opens the main opening 10a and the sub-opening 10b, and also opens the inlet port 6. Air taken in from the inlet port 6 flows from the outlet port 8 according to the opening and closing of the reed valve portion 12. Secondary air can be supplied at the maximum flow rate into the exhaust system pipe 64 shown in FIG.

In this embodiment, the material of each member constituting the valve device 2 is not particularly limited, and is made of metal, rubber, synthetic resin, or the like. However, preferably, the diaphragm 20 is made of a flexible member such as a thin metal plate, synthetic resin or rubber, the valve body 40 is made of an elastic member such as synthetic resin or rubber, and the

covers

4b, 4c and 4d are It is made of metal.

The valve device 2 according to the present embodiment can be suitably used as the secondary air introduction device 100 for exhaust gas purification countermeasures shown in FIG. That is, when a relatively large amount of secondary air is sent from the outlet port 8 to the exhaust system pipe 70 to promote purification of exhaust gas, an intermediate pressure is introduced into the first pressure chamber 14a, as shown in FIG. 1A. The pressure in the first pressure chamber 14a and the second pressure chamber 14b is balanced to bring the shut valve body 40 into the fully open position.

Further, when there is a high possibility that afterburning will occur in the exhaust system piping 64 shown in FIG. 2, a pressure higher than the intermediate pressure is introduced into the first pressure chamber 14a. As a result, as shown in FIG. 1B, the diaphragm 20 is pushed down from the first pressure chamber 14a toward the second pressure chamber 14b, and the drive rod 30 is moved in the axial direction to bring the shut valve body 40 into the fully closed position. As a result, the inlet port 6 is completely blocked, the supply of air to the exhaust system pipe 64 through the outlet port 8 is completely shut off, and the possibility of afterburning can be made extremely low. Further, backflow from the exhaust system pipe 64 to the valve device 2 can also be prevented.

Further, there is a possibility that afterburn may occur in the exhaust system pipe 64, but when the possibility is low, or when the temperature of the reed valve portion 12 exceeds the set temperature, the first pressure chamber 14a is Introduce a lower pressure than medium pressure. As a result, as shown in FIG. 1C, the diaphragm 20 is pushed up from the second pressure chamber 14b toward the first pressure chamber 14a, the drive rod 30 is moved in the axial direction, and only the sub opening 10b is opened. The shut valve main body 40 is set to a small flow position. As a result, a small amount of air can flow from the inlet port 6 to the reed valve portion 12 through the sub-opening portion 10b, and it is easy to prevent the reed valve portion 12 from being overheated.

The present invention is not limited to the above-described embodiment, and can be variously modified within the scope of the present invention.
For example, the valve device 2 according to the present invention can be applied not only to the secondary air introduction device 100 shown in FIG. 2 but also to other devices.

Industrial application fields

The present invention is used, for example, as a secondary air introduction device for exhaust gas purification measures of a gasoline engine and a valve device used therefor.

DESCRIPTION OF SYMBOLS 2 ... Valve apparatus 4 ... Casing 4a ... Casing main body 4b ... Inlet port cover 4c ... Outlet port cover 4d ... Pressure chamber cover 4f ... Septum 6 ... Inlet port 8 ... Outlet port 10 ... Communication flow path 10a ... Main opening 10b ... Secondary Opening portion 12 ... Reed valve portion 14 ... Pressure chamber 14a ... First pressure chamber 14b ... Second pressure chamber 16 ... Shut valve portion 20 ... Diaphragm 30 ... Drive rod 34 ... Spring 40 ... Shut valve body 52 ... First valve seat 54 2nd valve seat 60 ... Engine 62 ... Intake system piping 64 ... Exhaust system piping 70 ... Secondary air supply piping 100 ... Secondary air introduction device

Claims

An inlet port into which the main fluid is introduced, an outlet port through which the main fluid is discharged, and a casing having a communication flow path connecting the inlet port and the outlet port;
A reed valve portion provided on the outlet port side of the communication flow path inside the casing;
A valve device having a shut valve portion provided on the inlet port side of the communication flow path inside the casing,
The shut valve portion is
A drive rod having one end connected to the diaphragm and movable in the axial direction according to the pressure of the pressure chamber partitioned by the diaphragm;
A shut valve main body that is fixed to the rod and moves in the axial direction together with the rod, and according to the axial position of the drive rod, the shut valve main body fully opens the communication channel, and A valve device that is movable between a position at which the communication flow path is fully closed and a position at which the main flow path of the communication flow paths is closed but the sub flow path is not closed.
Inside the casing, in the middle of the communication flow path from the inlet port to the reed valve part, a main opening constituting the main flow path and an opening area smaller than the main opening are the sub flow path And a sub-opening that constitutes
Inside the casing,
A first valve seat in which the shut valve main body abuts and the communication flow path is fully closed at a position where the drive rod is moved to the inlet port side along the axial direction to the maximum extent;
A second valve seat that contacts the shut valve main body and closes the main flow path of the main opening at a position where the drive rod has moved to the maximum pressure chamber side along the axial direction;
2. The fluid flow from the inlet port to the lead portion through the sub-flow path of the sub-opening is allowed at a position where the shut valve main body abuts on the second valve seat. Valve device.
The valve device according to claim 2, wherein the second valve seat is formed outside the main opening.
A secondary air introduction device having the valve device according to any one of claims 1 to 3.