JPS6033293Y2 - Secondary air supply device - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a secondary air supply device that supplies secondary air into exhaust gas for the purpose of purifying the exhaust gas of an internal combustion engine. The present invention relates to an improvement regarding a secondary air supply device having a plurality of secondary air supply systems that supply secondary air into an exhaust passage using exhaust pulsation.

Conventional technology As one of the exhaust gas purification measures for internal combustion engines, in order to re-burn harmful unburned substances such as HC and Co contained in the exhaust gas, the secondary air in the exhaust system is It has been known for a long time to supply

It is also known that such secondary air is supplied not by an air pump mechanically driven by the output shaft of the engine, but by utilizing the arterial phenomenon of the exhaust gas flow in the exhaust system. .

A secondary air supply device using such exhaust pulsation includes an air passageway that is substantially open to the atmosphere via an air cleaner or the like at one end and connected to an exhaust pipe system such as an exhaust port or an exhaust manifold at the other end; A check valve is installed in the middle of the air passageway to allow air to flow from the atmosphere side toward the exhaust pipe system, but prevents air from flowing in the opposite direction, especially a lightweight check valve such as a reed valve. When negative pressure is generated in the exhaust pipe system due to the pulsation of exhaust gas flowing into the exhaust pipe system, air is introduced into the exhaust pipe system through the air passage including the check valve, thereby creating a secondary It supplies air.

Problems that the invention aims to solve By the way, internal combustion engines for automobiles are often configured as multi-cylinder engines with four or more cylinders, and the exhaust from each cylinder is routed through an exhaust manifold or into two systems. In this case, in order to efficiently supply secondary air using the exhaust pulsation as described above, it is necessary to connect the secondary air supply passage to the exhaust system. Therefore, such a secondary air supply passage is usually connected to each branch pipe section of the exhaust manifold or to the exhaust port section of the cylinder head.

Therefore, the secondary air supply passageway containing the check reed valve generally
The number of systems corresponding to the number of cylinders is provided, such as four systems for a four-cylinder engine and six systems for a six-cylinder engine.

Alternatively, in order to more effectively introduce secondary air through exhaust pulsations in view of the mutual interference of pulsations within each branch pipe section, the exhaust manifold may be configured such that, in the case of a four-cylinder engine, Instead of the branch pipes to be connected being uniformly collected at one point, for example, the branch pipes connected to the first and fourth cylinders are first collected as a first intermediate branch pipe, and then the branch pipes connected to the first and fourth cylinders are first collected as a first intermediate branch pipe, A configuration is adopted in which the branch pipes connected to the third cylinder are assembled to form a second intermediate branch pipe, and these first and second intermediate branch pipes are collected to finally form one exhaust pipe. Therefore, in a structure in which such an intermediate branch pipe is provided, it is preferable that the secondary air supply passage system including the non-return valve is connected to the intermediate branch pipe. In this case, two secondary air supply systems will be provided.

By the way, the secondary air supply device that utilizes exhaust pulsation introduces secondary air into the exhaust system by using the negative pressure generated in the exhaust pipe due to exhaust pulsation as described above. Generally, the device operates in a preferred manner when the engine is in a high-speed, high-load operating state or lower, but when the engine is in a high-speed, high-load operating state that exceeds the operating state, reed valve resonance or surging may occur. This causes a backflow phenomenon of fluid flowing in the opposite direction through the non-return reed valve, and there is a risk that high-temperature exhaust gas will reach the reed valve and cause it to burn out.

Furthermore, as the engine load increases, the exhaust gas temperature also increases, so if secondary air is introduced into the exhaust system even under high-load operating conditions that exceed a predetermined level, unburned components will enter the exhaust system. Combustion in the exhaust gas increases the exhaust gas temperature and there is a risk of burning out the catalytic converter.

Also, before the engine warms up, a large amount of unburned components are discharged into the exhaust system due to the supply of rich mixture.
If secondary air is supplied in such an operating state before warm-up, there is a risk that the catalytic converter will burn out due to combustion of a large amount of unburned components in the catalytic converter.

Therefore, in order to prevent overheating and burnout of the catalytic converter due to such secondary air supply, a shutoff valve is provided in the middle of the secondary air supply passage including a check reed valve, and in operating conditions where the supply of secondary air is not desirable, It has been proposed to stop the supply of secondary air by blocking the secondary air supply passage.

Such a shutoff valve is controlled on the basis of a state variable representative of the load state of the engine, such as intake manifold negative pressure.

When providing such a shutoff valve, if a multi-cylinder engine has multiple secondary air supply systems as described above, instead of providing an independent shutoff valve for each system, multiple It is conceivable that if a common shutoff valve is provided for the secondary air supply system, the configuration of the entire secondary air supply system can be simplified accordingly.

In this case, as a matter of course, the multiple secondary air supply systems are combined into one system upstream of the part including the single check valve, and a cutoff valve is provided in this one air passage part. There must be.

However, if multiple secondary air supply systems are branched downstream of the shutoff valve in this way, even when the shutoff valve is closed, they will not be connected to each other through such branch pipes. Fluid flow occurs from one system to another due to reed valve resonance or surging between multiple secondary air supply systems that are in communication,
As a result, in the secondary air supply system on the side where the fluid flow is reversed, the high temperature exhaust gas reaches the reed valve, and there is a risk of burning out the reed valve.

The present invention includes a plurality of secondary air supply systems and provides a common shutoff valve for these plurality of systems to simplify the structure of the secondary air supply system. It is an object of the present invention to address the problem and provide an improved secondary air supply device, particularly in the structure of the section including the shutoff valve. To provide a secondary air supply device in which the structure of a valve device is simplified and streamlined by incorporating a plurality of check reed valves and a common cutoff valve that acts on them in one valve housing. The purpose is to

Means for Solving the Problems According to the invention, the object is to provide a shut-off valve, a shut-off valve which is substantially open to the atmosphere at one end through said shut-off valve, and which is open to the exhaust passage of the internal combustion engine at the other end. and a plurality of passages each including a one-way check valve in the middle thereof, and configured to introduce secondary air into the exhaust passage using exhaust pulsation of the internal combustion engine when the shutoff valve is opened. In the secondary air supply device, the shutoff valve and the check reed valve have a common port at one end, individual ports for each of the plurality of systems at the other end, and an internal a partition that partitions an individual space that communicates only between each of the individual ports and a mutually different part of the common port; and a partition that connects the inside of each of the individual spaces partitioned by the partition to the individual port. a housing having a valve seat separating a space communicating with the common port and a space communicating with a part of the common port, leaving one valve port; and a housing having a valve seat attached to each of the valve seats and provided with the valve seat. A valve including a reed piece that closes in a non-returning manner, and a valve element that opens and closes the entire common port at once and substantially blocks communication between the different portions of the common port. secondary air provided by a structure, wherein the shutoff valve is configured to substantially block communication between the plurality of systems in the shutoff valve when the shutoff valve closes. Distantly related to feeding equipment.

According to this configuration, the above-mentioned problems in a secondary air supply device that supplies secondary air to the exhaust system of an internal combustion engine by utilizing the pulsation of exhaust gas in the exhaust system are solved. The secondary air supply device has a simple structure in which the main parts, a shutoff valve and a check reed valve, are incorporated into an integrated housing.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail with reference to the accompanying drawings.

The accompanying drawing is an illustrative sectional view showing one embodiment of the secondary air supply device according to the present invention.

In the figure, 1 is the main body of a four-cylinder internal combustion engine, and each cylinder structure includes a cylinder 2 and a piston 3 that reciprocates inside it, and a combustion chamber 4 is defined above the piston 3. ing.

The combustion chamber 4 has an intake port 6 that is opened and closed by an intake valve 5.
The air-fuel mixture sent by the intake manifold 7 is supplied through the air-fuel mixture, and the combustion gas generated by the combustion of the air-fuel mixture is directed to the exhaust manifold 10 through an exhaust port 9 that is opened and closed by an exhaust valve 8. is emitted as exhaust gas.

In this embodiment, the exhaust manifold 10 for a four-cylinder structure includes a first intermediate branch pipe 10' which is composed of a collection of branch pipes for the first and fourth cylinders, and second and third branch pipes. It has a structure including a second intermediate branch pipe 10'' which is configured by a collection of branch pipes for the cylinders.

A first secondary air supply passage 1 is provided in the first intermediate branch pipe 10'.
One end of the second secondary air supply passage 12 is connected to the second intermediate branch pipe 10''.

These first and second secondary air supply passages each include check reed valves 13 and 14 in the middle thereof.

The check reed valves 13 and 14 are incorporated into a valve housing integral with the isolation valve 15.

The shutoff valve 15 is constructed as a diaphragm valve and includes a diaphragm 16, a diaphragm chamber 17 defined on one side thereof, a compression coil spring 18 imparting a bias force to said diaphragm, and a valve element 19 actuated by said diaphragm. , a valve seat 20 cooperating with the valve element, a valve port 21 defined by the valve seat, etc.

The diaphragm chamber 17 is applied with negative pressure in the intake manifold 7 via a negative pressure conduit 22, and when the engine is operating under medium load and a sufficiently high intake manifold negative pressure is applied to the diaphragm chamber 17. When the engine is in a high-load operating state, the diaphragm 16 is displaced to the right in the figure against the action of the spring 18, opening the valve port 21. When the diaphragm 16 is lowered, the diaphragm 16
The valve element 19 is displaced to the left in the figure by the action of the valve element 19, and the valve element 19 is brought into contact with the valve seat 20, thereby closing the valve port 21.

The valve housing 26 is connected to the first and second secondary air supply passages 1
with separate ports 27 and 28 for 1 and 12;
Furthermore, the internal space is connected to these individual ports 27 and 28.
and the valve port 2 of the shutoff valve that acts in common with each of them.
It has a partition 25 that partitions into separate spaces 29 and 30 that communicate only with mutually different parts of the space.

Furthermore, the valve housing 26 is provided with a partition 3 that partitions the interior of each of the individual spaces 29 and 30 into a space 29a that communicates with the port 27 and a space 29b that communicates with a portion of the valve port 21, respectively.
1 and the space 30 into a space 30a that communicates with the port 28 and a space 30b that communicates with a part of the valve port 21.
is provided.

Valve ports 33 and 34 are provided in these partitions 31 and 32, respectively, and these valve ports can be closed in a non-returning manner by reed pieces 35 and 36, respectively.

Thus, the valve port 33 and the reed piece 35 constitute the check reed valve 13, and the valve port 34 and the reed piece 3 constitute the check reed valve 13.
6 constitutes a check reed valve 14.

Note that the arcuate curved pieces 37 and 38 fixed to the valve seats 31 and 32, respectively, are reed pieces 35 and 3, respectively.
This device restricts the deformation of valve 6 in the valve opening direction.

When the valve port 21 of the isolation valve 15 is open, the secondary air supply passages 11 and 12 pass through the respective ports 33 and 34 of the check reed valve and a corresponding portion of the valve port 21 to the isolation valve 15. The valve chamber 23 is connected to the atmosphere through a conduit 24 and an air cleaner, etc. (not shown), and is exposed to the atmosphere through a conduit 24 and an air cleaner etc. not shown in the figure. The air is passed through the conduit 24, the valve chamber 23 and valve port 21 of the isolation valve, the valve port 33 or 34 of the check reed valve,
Through the passage 11 or 12, the intermediate branch pipe 10' or 1
0".

In the illustrated embodiment, the end of the partition 25 facing the valve port 21 terminates in the same plane as the valve seat 20 so that when the valve element 19 abuts the valve seat 20 and closes the valve port 21,
Communication between the two secondary air supply systems defined on both sides of the partition 25 is also cut off.

According to this structure, the valve port 21 is closed by the valve element 19 in order to stop the supply of secondary air during high load operation of the engine.
When the valve port 21 is closed, at the same time, communication between the portions of the valve port 21 corresponding to the two secondary air supply passages 11 and 12 is cut off, whereby the secondary air supply passage 11
Or check reed valve 13 or 1 from either one of 12
The risk of a gas flow flowing across 4 in a counter-flow direction to the other secondary air supply channel is prevented.

In the embodiment shown, the partition 25 ends in the same plane as the valve seat 20, so that when the valve element 19 rests on the valve seat 20, it simultaneously rests on the edge of the partition 25. However, instead of this, the partition 25 may end somewhat in front of the partition 25, for example at the position shown at D, and with such a structure also two secondary The effect of substantially blocking communication between the air supply systems is achieved.

Although the present invention has been described above in detail with respect to a specific embodiment in which a common shutoff valve is provided for two secondary air supply systems, the present invention is applicable to three or more secondary air supply systems. It should be understood by those skilled in the art that the same applies to the secondary air supply system including the system, and that various modifications can be made to the combination structure of the illustrated check reed valve and shutoff valve within the scope of the present invention. It would be obvious for

Effects of the invention Thus, the invention has a simple structure that includes a plurality of secondary air supply systems and has a common shutoff valve for these systems. A secondary air supply device without the risk of short-circuit flow between systems crossing the valve in the reverse flow direction, in particular a compact structure in which the shutoff valve and the one-way check valve are incorporated in a single housing. It will be appreciated that a secondary air supply system is obtained which provides

[Brief explanation of the drawing]

The accompanying drawing is an illustrative sectional view showing one embodiment of the secondary air supply device according to the present invention. 1... Engine body, 2... Cylinder, 3
...Zeston, 4...Combustion chamber, 5...
...Intake valve, 6...Intake port, 7...
...Intake manifold, ...Exhaust valve, 9...
...Exhaust port, 10...Exhaust manifold, 1
0', 10'... Intermediate branch pipe of exhaust manifold, 11.12... Secondary air supply passage, 13,1
4...Check reed valve, 15...Shutoff valve, 16...Diaphragm, 17...Diaphragm chamber, 18...Compression coil spring, 19
...Valve element, 20...Valve seat, 21...
... Valve port, 22 ... Negative pressure conduit, 23.
... Valve chamber, 24 ... Conduit, 25 ...
...Partition, 26...Valve no. 1 housing, 27.2
8...Port, 29, 29a, 29b, 30.
30a, 30b = chamber space, 31.32... valve seat, 33, 34... valve port, 35.36...
...Reed piece, 37. 38--Lead piece deformation limiting member.

Claims (1)

[Scope of utility model registration request] a system of passages including one shutoff valve and a plurality of passages that are open substantially to the atmosphere through the shutoff valve at one end, open to the exhaust passage of the internal combustion engine at the other end, and include check reed valves along the way; , a secondary air supply device configured to introduce secondary air into the exhaust passage by utilizing exhaust pulsation of an internal combustion engine when the shutoff valve is open; A double valve has a common port at one end, individual ports for each of the plurality of systems at the other end, and internally includes each of the individual ports and different parts of the common port. a partition that separates individual spaces that communicate with each other; a space that communicates the interior of each of the individual spaces partitioned by the partition with the individual port; and a valve that connects a space that communicates with a part of the common port. a valve housing having a valve seat partitioning off the valve seat with a valve seat; a reed piece attached to each of the valve seats to checkably close the valve port provided by the valve seat; and when opening and closing the entire common port at once. and a valve element substantially blocking communication between the different portions of the common port, the isolation valve being closed by a valve element that substantially blocks communication between the different portions of the common port; A secondary air supply device characterized in that it is configured to substantially block communication between the plurality of systems.