JPH09250338A - Exhaust purifying device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exhaust purifying device whose both valves are not closed even if a shaft disposed between two valves might be broken. SOLUTION: In an exhaust purifying device of an engine whose bypass passage and catalyst passage have a B valve 3 and a C valve 2 connected to a single shaft 4 and are selected by an actuator, the B valve 3 is shaped like an elongated circle so that the B valve 3 opens when the force exerted on the B valve by the shaft 4 is eliminated.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an exhaust emission control device.

[0002]

2. Description of the Related Art As a conventional exhaust emission control device, for example, there is one shown in FIG. 4 (Japanese Patent Laid-Open No. 6-2292).
No. 61, etc.). In such a conventional exhaust emission control device, the two valves 2 and 3 of the bypass valves are driven by the single shaft 4. In addition, 5 is a lever for rotating the shaft 4.

[0003]

In the above-mentioned conventional technique, if the shaft 4a between the two valves 2 and 3 should break, both valves 2 and 3 will be closed. There was a problem. The present invention has been made in view of such conventional problems, and provides an exhaust emission control device in which both valves are not closed even if the shaft between the two valves is broken. The purpose is to do.

[0004]

In order to achieve the above object, in the invention according to claim 1, a valve is provided in each of a plurality of exhaust passages of an internal combustion engine, and a shaft of the valve is provided.
In an exhaust emission control device that is driven by a common drive device to switch the exhaust passage, the valve on the side far from the drive device has a shape that opens when the force from the drive device is no longer applied to the shaft. In the invention according to claim 2,
In the exhaust emission control device according to claim 1, the valve gravity center on the far side is offset with respect to the shaft. According to a third aspect of the present invention, in the exhaust emission control device according to the first or second aspect, the valve shape on the far side is an oval shape.
According to a fourth aspect of the invention, in the exhaust emission control device of the first or second aspect, the valve shape on the far side is a wedge type. According to a fifth aspect of the present invention, in the exhaust emission control device according to any one of the first to fourth aspects, a moment opposite to the moment generated by the valve on the side closer to the drive device is generated by the valve on the side farther from the drive device. A fin was attached to the side that generated. According to a sixth aspect of the present invention, in the exhaust emission control device according to the fifth aspect, when the valve on the near side is opened, the fin is twisted so that a swirl flow can be generated in the valve downstream flow, and The catalyst was placed.

[0005]

In the present invention, the valve on the side far from the valve drive device may be formed into an oval shape (claim 3), or the weight before and after the valve may be changed (claim 4) to shift the center of gravity of the valve from the shaft. (Claim 2), the valve is opened when the force applied from the shaft is not applied to the valve farther from the drive device. Therefore, when the shaft is broken, the valve is opened. In the invention according to claim 5, since the valve on the side closer to the drive device is provided with fins, the center of gravity shifts when the valve on the side far from the valve drive device is closed. The force applied is offset by the gas pressure applied to the fins to cancel the force applied to the actuator. In the invention according to claim 6,
By attaching fins to the valve on the catalyst side, exhaust gas is diffused throughout the catalyst, which helps improve the activity.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 are views showing a first embodiment of the present invention. First, the structure will be described. 1 is a valve body. B inserted in the bypass passage 10
The valve 3 and the C valve 2 interposed in the catalyst passage 13 are connected to each other by the shaft 4 in the valve body 1 so that when one of the B valve 3 and the C valve 2 is fully opened, the other valve is fully closed. is set up. On the shaft 4, a lever 5 that connects an actuator 6 for opening and closing the B and C valves 3 and 2 and the shaft 4 is installed on the C valve 2 side. Further, the C valve 2 is provided with fins 7 on a surface which is an upper surface when the C valve 2 is fully closed and at a position which is below the shaft 4 when the C valve 2 is fully opened. Reference numeral 8 is an exhaust manifold, and 9 is a catalyst.

Next, the operation will be described. When the shaft 4 is broken between the B valve 3 and the C valve 2 due to vibration, heat deterioration, etc., if the B valve 3 and the C valve 2 are both closed,
Exhaust gas is not emitted, and in that case, serious trouble such as engine stall may occur. Therefore, it is sufficient that the B valve 3 is always opened when the B valve 3 becomes free when the shaft 4 is broken. As a method thereof, the B valve 3 is formed into an oval shape and is eccentric so that the gas pressure changes between the left and right of the shaft 4 when closed. The center of gravity of the B valve 3 is the shaft 4
It is arranged so as to be displaced from the upper side so that when the force from the shaft 4 disappears, it is always opened due to the pressure difference of the gas and the weight of the valve itself to avoid a problem.

However, with this configuration, when the shaft is normal, the force that tries to open the B valve 3 is always applied to the actuator 6 from the B valve 3 through the shaft 4, which causes variations in the opening and closing times and stress. There is a possibility that the actuator 6 may be defective. Therefore, in the first embodiment, the C valve 2
The fin 7 as described above is attached to the fin 7, and exhaust gas hits the fin 7 to generate a force to open the C valve 2 (that is, a force to close the B valve). This power and the fin 7
Since the weight of the fin 7 increases, the center of gravity of the C valve 2 substantially shifts, and the force of the C valve 2 opening cancels the force of the B valve 3 opening.
To prevent the application of force. Further, when the C valve 2 is opened by the fins 7 of the C valve 2, the gas that has passed through the C valve 2 side is diffused in a vortex and passes through the entire catalyst 9 to prevent partial deterioration of the catalyst 9 and the conversion rate. Improvements are also obtained and emissions are improved.

A second embodiment is shown in FIG. This embodiment is different from the first embodiment in that the B valve 3 is changed. In the first embodiment, the B valve 3 has an elliptical shape.
Although the center of gravity of the B valve is shifted from the top of the shaft 4, in the second embodiment, the center of gravity is displaced from the top of the shaft 4 by changing the upper and lower thicknesses of the B valve 3 as shown in FIG. To do. As a result, the same effects as those of the first embodiment can be obtained, and there is an advantage that processing can be facilitated. In each embodiment, the shaft 4 has a single structure, but may have a structure in which a plurality of shafts arranged on the same axis are connected.

As described above, according to the embodiment of the present invention, the structure is such that the center of gravity of the B valve 3 is eccentric and the fin 7 is attached to the C valve 2. Therefore, the B and C valves of the shaft 4 are provided. When 3 and 2 are broken, a serious trouble can be avoided, and in the normal state, the fin 7 of the C valve 3 improves the activity of the catalyst to improve the emission and the force in the opening direction to the actuator 6. The effect that the responsiveness is good can be obtained without acting.

[0011]

As described above, according to the present invention, since the valve on the side far from the drive device is shaped to open when the force from the shaft is removed, It is possible to avoid the serious problem that both valves are closed when the shaft is broken. Further, in the invention according to claim 5, since a fin is attached to the valve on the side closer to the drive unit to generate a reverse moment with respect to the moment of the valve on the side far from the drive unit under normal conditions, the response of valve opening / closing It is possible to obtain the effect that the property can be improved. In addition, claim 6
In the invention described above, the fins are twisted so that a swirl flow can be generated in the wake of the valve by the fins, so that there is an effect that the activity of the catalyst in the wake of the valve is improved and the emission is improved.

[Brief description of drawings]

FIG. 1 is a valve assembly diagram of the first embodiment.

FIG. 2 is a system diagram of the first embodiment.

FIG. 3 is a valve assembly diagram of the second embodiment.

FIG. 4 is a conventional diagram.

[Explanation of symbols]

 1 Valve Body 2 C Valve (Valve on Drive Side) 3 B Valve (Valve on Far Side from Drive) 4 Shaft 5 Lever 6 Actuator (Drive) 7 Fins 8 Exhaust Manifold 9 Catalyst 10 Bypass Passage 13 Catalyst Passage

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akira Tayama 2 Takaracho, Kanagawa-ku, Yokohama, Kanagawa Nissan Motor Co., Ltd.

Claims (6)

[Claims] 1. An exhaust gas purification device in which a valve is provided in each of a plurality of exhaust passages of an internal combustion engine, and a shaft of the valve is driven by a common drive device to switch the exhaust passages, the side away from the drive device. The exhaust purification device is characterized in that the valve has a shape that opens when the force from the drive device is not applied to the shaft. 2. The exhaust gas purification device according to claim 1, wherein the center of gravity of the valve on the far side is offset with respect to the shaft. 3. The exhaust emission control device according to claim 1, wherein the valve shape on the far side is oval. 4. The exhaust emission control device according to claim 1, wherein the valve shape on the far side is wedge-shaped. 5. A fin is attached to a side of the valve that is closer to the drive device than a moment of the valve that is far from the drive device. The exhaust emission control device according to any one of the above. 6. The fin is twisted so that a swirl flow can be generated in the valve downstream flow when the valve on the near side is opened, and a catalyst is disposed in the valve downstream flow. Exhaust gas purification device described.