JP2008031887A - Mounting structure of exhaust control valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide mounting structure of an exhaust control valve facilitating a mounting step and reduced in size in such a way that a tubular part of a control valve is inserted from a rear face of a burring part, the tubular part of the control valve is exposed from the burring part, and then an outer periphery of the exposed part is welded. <P>SOLUTION: The mounting structure of an exhaust control valve is constituted of: a baffle plate 2 partitioning an exhaust flow passage; a vent hole 3 formed in the baffle plate 2; and the control valve 1 attached to the vent hole 3. The control valve 1 has the tubular part 4 fitted to an inner periphery of the vent hole 3, and a valve element 5 urged in a direction closing the tubular part 4. An edge of the vent hole 3 is bent on one side so as to form the burring part 10, the tubular part 4 of the control valve is inserted from the vent hole 3 with burring part 10 toward an front end direction, the front end part of the tubular part 4 is exposed from the front end of the burring part 10, and then the outer periphery of the exposed tubular part 4 is welded with the burring part 10. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an exhaust control valve mounting structure, and in particular, inserts a cylindrical portion of the control valve from the back surface of the burring portion, slightly exposes the cylindrical portion of the control valve from the burring portion, and The present invention relates to an exhaust control valve mounting structure that facilitates the mounting process and achieves compactness by welding the outer periphery.

  This type of conventional exhaust control valve has a silencing effect by opening and closing an exhaust passage that is arranged so that small chambers inside the muffler body communicate with each other in an arbitrary combination in response to fluctuations in exhaust pressure flowing from the engine side. In order to prevent the engine output from being reduced due to exhaust pressure loss, it is built into the muffler. As such an exhaust control valve, for example, as shown in FIG. 4, the exhaust control valve is provided so as to be openable and closable via a support shaft with respect to an annular seat surface of a valve seat provided at an end of an exhaust pipe in the muffler body. It has a structure comprising a valve body 51 and a coil spring 52 that is engaged with the support shaft and biased in the direction of closing the control valve by bringing the valve body into contact with the seat surface of the valve seat. When the engine is rotating at a low speed, the urging force of the coil spring 52 causes the exhaust pipe to close so that the silencing effect is given priority. When the engine is rotating at a high speed, the exhaust pressure exceeds the urging force of the coil spring 52. The exhaust pipe is sometimes opened by pushing and opening the valve body, and priority is given to preventing reduction in engine output due to low back pressure at high speed (for example, see Patent Document 1).

JP 2002-235536 A (page (3) of the specification, FIG. 1)

  By the way, the exhaust gas silencer is configured such that the exhaust gas is silenced while passing through a plurality of spaces partitioned by the baffle plate 53, and the baffle plate 53 has a vent hole 54 formed therein. The vent hole 54 is formed with a burring portion 55 as shown in FIGS. The burring portion 55 is attached by fitting a control valve 56 assembled in advance.

On the other hand, there is a standard part that integrally includes the cylindrical portion 57 and the valve body 51 so that the control valve 56 can be inserted and fixed in the vent hole 54 of the baffle plate, and can be directly attached to the baffle plate 53. ing.
And in the attachment of a control valve, as shown in FIG. 5, the method of inserting the cylindrical part 57 of the control valve 56 in the same direction as the bending direction of the burring part 55 is employ | adopted. However, according to this method, the spring base end 58 protruding from the valve seat interferes with the baffle plate 53, so that there is a problem that downsizing is hindered.
Moreover, as shown in FIG. 6, the method of inserting and attaching the cylindrical part 57 of a control valve from the front-end | tip of the burring part 55 is employ | adopted. However, in this configuration, since the portion sandwiched between the baffle plate 53 and the valve seat 59 is extremely narrowed, it is difficult to insert the welding torch.
Therefore, although the tip of the cylindrical portion 57 of the control valve is welded, there is a possibility that weld spatter will be scattered in the cylindrical portion at the time of welding and the inside will be soiled. Moreover, in this method, as shown in FIG. 7, the bead 60 after welding protrudes and becomes an obstacle to insertion of the muffler pipe 61.
In addition, since the control valve 56 includes parts that have been standardized in advance as described above, the rising height of the burring portion is also limited by the opening area of the valve, and the length of the tubular portion depends on the shape. It is difficult in terms of cost to freely change the value.

  The present invention has been made to solve the above-mentioned problems, and the object of the present invention is to insert the cylindrical portion of the control valve from the back surface of the burring portion, and to remove the cylindrical portion of the control valve from the burring portion. It is an object of the present invention to provide an exhaust control valve mounting structure that is slightly exposed and welds the outer periphery of the exposed portion, thereby facilitating and compacting the mounting process.

  In the first aspect of the present invention, the exhaust flow passage formed in the exhaust gas silencer main body, the baffle plate that partitions the exhaust flow passage, the vent holes formed in the baffle plate, and the vent holes In the exhaust control valve mounting structure constituted by the control valve to be mounted, the control valve includes a cylindrical portion fitted on the inner periphery of the vent hole, and a valve body biased in a direction to close the cylindrical portion. A burring portion is formed by bending the hole edge of the vent hole to one side, and the cylindrical portion of the control valve is inserted from the base portion of the vent hole forming the burring portion toward the distal end, and the cylindrical portion. The tip of the burring portion was exposed from the tip of the burring portion, and the outer periphery of the exposed cylindrical portion and the burring portion were welded and fixed.

In the first aspect of the present invention, the exhaust flow passage formed in the exhaust gas silencer main body, the baffle plate that partitions the exhaust flow passage, the vent hole formed in the baffle plate, In the exhaust control valve mounting structure constituted by the control valve mounted on the vent hole, the control valve biases the cylindrical portion fitted on the inner periphery of the vent hole and the direction of closing the cylindrical portion. A valve body is provided, the hole edge of the vent hole is bent to one side to form a burring portion, and the tubular portion of the control valve is inserted from the base portion of the vent hole forming the burring portion toward the distal end, Since the tip end portion of the cylindrical portion is exposed from the tip end of the burring portion and the outer periphery of the exposed cylindrical portion and the burring portion are fixed by welding, the mounting of the control valve and the baffle plate is made compact.
Moreover, since the outer periphery of the cylindrical portion is welded, the welding operation is facilitated and weld spatter is not scattered on the air passage. Furthermore, there is no possibility that the insertion of the muffler pipe is hindered by the rise of the welding beat.

  Embodiments of the present invention will be described below with reference to the drawings.

Example 1 will be described below.
FIG. 1 is a cross-sectional view of a state in which a control valve is inserted into a baffle plate, FIG. 2 is a cross-sectional view of a state in which the control valve is attached, and FIG. 3 is a schematic cross-sectional view of a silencer body to which the control valve is applied.

First, the overall configuration of the exhaust control valve will be described.
As shown in FIGS. 1 and 2, the exhaust control valve 1 includes a tubular portion 4 that fits into a vent hole 3 formed in the baffle plate 2, and a valve body 5 that opens and closes the proximal end side of the tubular portion 4. The valve body 5 is configured to have a coil spring 7 that urges the valve body 5 to be closed.
The tubular portion 4 has a diameter that fits into the inner periphery of the vent hole, and a valve seat 6 is connected to the proximal end, and the valve seat 6 extends orthogonally from the tubular portion to the outer periphery. The vent path is opened and closed by the operation of the valve seat 6 and the valve body 5.
When the tubular portion 4 is inserted into the vent hole 3, the valve seat 6 hits the baffle plate 2 and is fixed in a state where the valve seat 6 and the baffle plate 2 are in close contact with each other.

A coil spring 7 is wound around the support shaft of the valve body 5, the distal end 8 of the wound coil spring 7 is engaged with the valve body 5, and the base end 9 is passed through the valve seat 6 and the baffle plate 2. In combination, the valve body 5 is pressed against the valve seat 6 by the urging force of the coil spring 7.
Since the base end 9 of the coil spring 7 penetrates the baffle plate 2, the valve seat 6 can be brought into close contact with the baffle plate 2 without interference of the coil spring base end 9.

  The air passage is closed by the urging force of the coil spring 7 so as to give priority to the silencing effect at the time of low exhaust, and when the exhaust pressure exceeds the urging force of the coil spring 7 at the time of high-speed rotation of the engine. The body 5 is pushed open to open the ventilation path, and priority is given to preventing the engine output from decreasing due to low back pressure at high speeds.

Next, the attachment structure of the control valve to the baffle plate will be described.
The silencer body has an exhaust gas flow passage, and has a plurality of spaces on the flow path. Each space is partitioned by a baffle plate (partition wall), and a vent hole 3 is formed in the baffle plate. Yes.
Further, the vent hole 3 is formed with a burring portion 10 by bending the hole edge to one side. The burring portion 10 provides protection and strength of the periphery of the vent hole, and also forms a mounting portion for the control valve 1. Has been.

The exhaust control valve 1 is attached by inserting the tubular portion 4 of the control valve 1 from the back surface of the burring portion 10 of the vent hole 3 of the baffle plate 2. The valve seat 6 of the control valve 1 is bent at a right angle, and the bent portion is in close contact with the back surface of the baffle plate 2.
Here, the base end 9 of the coil spring 7 protrudes from the valve seat 6, and this protruding portion is accommodated in the through hole of the baffle plate 2.
Further, the tip portion of the cylindrical portion 4 is slightly exposed from the tip of the burring portion 10.
Due to the exposed portion, a step is generated between the outer edge of the end of the tubular portion 4 and the burring portion 10 and is easily fixed by welding the portion of the step. Here, even if the welding beat 11 protrudes, since there is no change in the inner periphery of the cylindrical portion, insertion of the muffler pipe 12 is not hindered.

Next, an exhaust gas silencer to which the present invention is applied will be described.
The silencer adopting the exhaust control valve mounting structure of the present embodiment has a structure in which the inside of the box-shaped body is partitioned by two baffle plates 2a and 2b in the upstream and downstream directions as shown in FIG. Two silencing chambers, a first chamber C1, a second chamber C2, and a third chamber C3 are formed, and an inlet pipe P1 is provided for taking in exhaust gas from the outside upstream. This inlet pipe P1 is provided with an opening 13 that is partially opened in the middle of the second chamber, and is provided so that the end is inside the third chamber C3 on the most upstream side. In addition, a branch pipe P2 is provided in the second chamber portion of the inlet pipe P1 so that a part of the exhaust flows into the second chamber without passing through the third chamber C3, and the exhaust is discharged from the pipe into the first chamber C1. Try to mute by spreading.
Moreover, the inner pipe P3 which connects a 1st chamber and a 3rd chamber is set, and the control valve 1 is attached to the 1st chamber side of this inner pipe.
The silencer is provided with an outlet pipe P4 for sending exhaust from the inside to the outside downstream. The outlet pipe P4 is provided so that the start end is inside the first chamber C1 on the most downstream side.

By mounting in this way, at the time of low exhaust, the exhaust from the inlet pipe P1 is discharged from the outlet pipe P4 through the opening 13 via the branch pipe P2.
When the engine speed rises and the exhaust gas is high, the exhaust from the end of the inlet pipe P1 flows into the first chamber by opening the control valve 1 of the inner pipe P3 and is discharged from the outlet pipe P4 in addition to the flow through the branch pipe P2. become.

Next, the operation of the present invention will be described.
A burring portion 10 is formed in the vent hole 3 of the baffle plate 2 of the exhaust gas silencer body.
The inner diameter of the burring portion 10 is set to a shape in which the outer periphery of the tubular portion 4 of the control valve 1 is fitted.
The cylindrical portion 4 of the control valve 1 is inserted from the back surface of the burring portion 10 and is pushed in and fixed until the valve seat 6 comes into close contact with the back surface of the baffle plate 2.
Here, the base end 9 of the coil spring 7 protrudes on the back side of the valve seat 6, and the protrusion of this coil spring is inserted in accordance with the through hole of the baffle plate 2. As a result, the control valve 1 main body is positioned and fixed, and the base end of the coil spring is fixed, and the valve body is biased in the direction of closing the air passage by the elasticity of the coil spring main body.
The tip of the cylindrical portion 4 is slightly exposed from the tip of the burring portion 10, and a step with the burring portion 10 is formed on the outer periphery of the exposed portion.
By welding the stepped portion, the control valve is fixed to the baffle plate.
Since the step portion is open to the outside, it is easy to insert the welding torch, and the outer periphery of the tubular portion is welded. The muffler pipe 12 is not inserted into the pipe.

Next, the effect will be described.
As described above, in the exhaust control valve mounting structure according to the first embodiment, since the control valve 1 is fixed to the burring portion 10, it can be securely mounted.
Further, the tubular portion 4 of the control valve is inserted toward the distal direction from the vent hole 3 in which the burring portion 10 is formed, the distal end portion of the tubular portion 4 is exposed from the distal end of the burring portion 10, and the exposed tube Since the outer periphery of the cylindrical portion 4 and the burring portion 10 are welded, there is no risk of welding spatter or the like adhering to the inner periphery of the cylindrical portion 4, and the welded portion does not protrude, so that the insertion of the muffler pipe is not hindered. .
Moreover, since the outer periphery of a cylindrical part is welded, a welding process is simplified and attachment is performed reliably.
Further, since the base end 9 of the coil spring 7 for urging the valve body 5 is inserted and fixed to the baffle plate 2, the control valve main body is positioned and the base end 9 does not interfere with the control valve and the baffle plate. Adheres and the mounting part is made compact.

Although the present embodiment has been described above, the present invention is not limited to the above-described embodiment, and design changes and the like within a scope not departing from the gist of the present invention are included in the present invention.
For example, in the embodiment described above, the shape of the vent hole 3 is cylindrical. However, as the cross-sectional shape of the cylindrical portion 4, it is also possible to apply a polygonal cylindrical portion 4 in addition to a cylinder.

It is sectional drawing of the state which inserted the control valve in the baffle plate. It is sectional drawing which shows the attachment state of a control valve. It is a schematic sectional drawing of the silencer main body to which the control valve is applied. It is a top view of the control valve which concerns on a prior art example. It is sectional drawing which shows the attachment state of the control valve which concerns on a prior art example. It is sectional drawing which shows the attachment state of the control valve which concerns on another prior art example. It is sectional drawing which shows the attachment state of the control valve which concerns on the prior art example at the time of muffler pipe insertion.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Control valve 2 Baffle plate 3 Vent hole 4 Tubular part 5 Valve body 6 Valve seat 7 Coil spring 8 Tip 9 Base end 10 Burring part 11 Welding beat 12 Muffler pipe

Claims (2)

Exhaust gas composed of an exhaust flow passage formed in the exhaust gas silencer body, a baffle plate that partitions the exhaust flow passage, a vent hole formed in the baffle plate, and a control valve attached to the vent hole In the control valve mounting structure,
The control valve includes a cylindrical portion that fits on the inner periphery of the vent hole, and a valve body that urges the cylindrical portion in a direction to close the cylindrical portion,
Bending the hole edge of the vent hole to one side to form a burring part,
The cylindrical part of the control valve is inserted toward the distal direction from the vent hole forming the burring part, the distal end part of the cylindrical part is exposed from the distal end of the burring part, and the outer periphery of the exposed cylindrical part and the burring part Exhaust control valve mounting structure with a structure that welds. The valve body of the control valve is biased in the direction of closing the cylindrical portion using the elasticity of the coil spring,
The exhaust control valve mounting structure according to claim 1, wherein a proximal end side of the coil spring is inserted and fixed to a baffle plate.

Images