JP2009013960A - Exhaust system valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a spring rotating and energizing a shaft of an exhaust system valve from being heated to high temperature by influence of heat of exhaust gas and materialize the prevention by a space-saving low cost structure. <P>SOLUTION: In the exhaust system valve, a shaft 12 rotating in a regular and a reverse direction for opening and closing a valve main body 3 in the exhaust pipe 6 is provided with passing through the exhaust pipe 6 in such a manner that at least one end side thereof is exposed from the exhaust pipe 6, and a coil spring 20 is provided around an exposure part 6a from the exhaust pipe 6 of the shaft 12 to energize and rotate the shaft 12. A leak gas guide pipe 23 is inserted through a part between the exposure part 12a and the coil spring 20, a base end part of the leak gas guide pipe 23 is connected to involve a leaking section of exhaust gas leaking through an exhaust pipe passing through part of the shaft 12, and a tip part is opened to the atmosphere. A shield 25 is provided between the exhaust pipe 6 and the coil spring 20 to insulate radiation heat from the exhaust pipe 6 to the coil spring 20. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an exhaust system valve provided in an exhaust system of an internal combustion engine or the like. In particular, the present invention relates to an exhaust system valve that prevents a spring that rotationally biases the shaft of the exhaust system valve from being heated to a high temperature due to the influence of heat of the exhaust gas.

  An exhaust system valve may be provided in an exhaust system of an internal combustion engine or the like for the purpose of switching an exhaust gas flow path, controlling an exhaust gas flow rate, or the like.

  In the exhaust system valves disclosed in Patent Documents 1 to 4, a valve body (valve element) is fixed to a shaft provided through an exhaust pipe. The valve body is structured to open / close or adjust the opening of the exhaust pipe by rotating the shaft in the forward / reverse direction. The shaft disclosed in any patent document is urged to rotate in the direction in which the valve body is opened or closed by a coil spring (torsion coil spring).

  In the exhaust system valve disclosed in Patent Document 1, a valve body composed of two thin plates arranged at right angles to each other is fixed to a shaft provided through an exhaust pipe. A coil spring that rotationally biases the shaft of the exhaust system valve is engaged with one end of the shaft.

  The exhaust gas flowing in the exhaust pipe flows generally along the pipe line of the exhaust pipe, but a part of the exhaust gas passes through the gap between the shaft of the exhaust system valve and the support cylinder supporting the shaft, and further, the support cylinder, It leaks out of the exhaust pipe through a gap with the cylinder fitted in the opening end of the support cylinder. The coil spring is installed at the exhaust gas leakage location, and is heated to a high temperature when the leaked exhaust gas blows. The coil spring is also heated to a high temperature by radiant heat from the exhaust pipe that has become a high temperature due to the heat of the exhaust gas.

  The exhaust system valve disclosed in Patent Document 2 has a valve body fixed to a shaft provided through a communication pipe that communicates two exhaust pipes. A coil spring that rotationally biases the shaft of the exhaust system valve is engaged with the upper end of the shaft.

  A cover is provided at a portion that penetrates the communication pipe of the shaft in order to ensure airtightness of a gap between the shaft and the communication pipe penetration portion of the shaft. However, this cover simply covers the gap and cannot sufficiently prevent the leakage of exhaust gas. Therefore, a part of the exhaust gas flowing in the communication pipe is between the shaft and the communication pipe penetration part of the shaft. Go through the gap. Furthermore, it leaks out of the communication pipe through the gap between the shaft and the cover. The coil spring is installed at the exhaust gas leakage location, and is heated to a high temperature when the leaked exhaust gas blows. The coil spring is also heated to a high temperature by radiant heat from the communication pipe that has become a high temperature due to the heat of the exhaust gas.

  The exhaust system valve disclosed in Patent Document 3 is configured such that a valve main body is fixed to a shaft disposed through an exhaust pipe. The exhaust pipe constitutes a part of an exhaust heat recovery device that recovers the heat of the exhaust gas via the refrigerant. The exhaust pipe has a triple structure of an inner pipe, an intermediate pipe, and an outer pipe, and the valve body is disposed so as to open and close the intermediate pipe. A coil spring that rotationally biases the shaft is also engaged with the upper end portion of the shaft of the exhaust system valve.

  Exhaust gas flowing in the outer pipe flows generally along the pipe line, but part of the exhaust gas leaks from a gap between the shaft and the outer pipe penetrating portion of the shaft. The coil spring is installed at the exhaust gas leakage location, and is heated to a high temperature when the leaked exhaust gas blows. Further, since the coil spring is in contact with the outer tube that has become high temperature due to the heat of the exhaust gas, the coil spring is also heated to high temperature by heat conduction from the outer tube. Further, the coil spring is also heated to a high temperature by the radiant heat from the shaft that has become a high temperature by the heat of the exhaust gas.

  The exhaust system valve disclosed in Patent Document 4 also has a valve body fixed to a shaft provided through the exhaust pipe, and a coil spring that urges the shaft to rotate at the upper end of the shaft. Is engaged.

In this exhaust system valve, a gas leakage prevention structure is provided between the exhaust pipe and the coil spring. This gas leakage prevention structure is configured by arranging a cylindrical case around a shaft and inserting a ring-shaped alloy plate through the shaft in the cylindrical case. The alloy plate in the cylindrical case seals the exhaust gas leaking from the gap between the shaft and the exhaust pipe penetration of the shaft in the cylindrical case, so it is considered that the exhaust gas leaks and directly hits the coil spring hard.
JP-A-6-88515 JP-A-10-274043 JP-A-9-76739 JP 7-259586 A

  As in the exhaust system valves disclosed in Patent Documents 1 to 3 listed above, when the spring that urges the shaft to rotate is heated to a high temperature by the influence of the heat of the exhaust gas flowing in the exhaust pipe, There is a problem that the performance of the spring is likely to deteriorate, and the performance required for the design is not satisfied early.

  In order to prevent the deterioration of the spring performance due to the heat of the exhaust gas, a spring made of a material such as a nickel alloy material having excellent heat resistance may be employed, but such a spring is expensive, There is a problem in that the manufacturing cost of the entire exhaust system valve is high.

  In addition, by adopting such an expensive spring having excellent heat resistance, the progress of the spring performance deterioration is suppressed to some extent, but in order to maintain the performance required for the design over a long period of time. It is necessary to periodically replace and inspect springs, which imposes a burden on inspection and maintenance.

  In the case where a gas leakage prevention structure is provided between the exhaust pipe and the coil spring as in the exhaust system valve disclosed in Patent Document 4 mentioned above, the leaked exhaust gas is blown directly to the coil spring. It ’s hard to think of it. However, in order to provide the gas leakage prevention structure, it is necessary to secure a large space in the longitudinal direction of the shaft, which causes a problem that the exhaust system valve is enlarged in the longitudinal direction of the shaft.

  Moreover, in the said gas leak prevention structure, in order to give high airtightness between a ring-shaped alloy plate and the inner surface of a cylindrical case, high precision is required for those processes. As a result, there arises a problem that the manufacturing cost is high.

  The present invention has been made in view of the above problems, and prevents the spring that rotationally biases the shaft of the exhaust system valve from being heated to a high temperature due to the influence of the heat of the exhaust gas. An object of the present invention is to provide an exhaust system valve that can be realized with a space and an inexpensive structure.

  As means for solving the above-described problems, the exhaust system valve of the present invention is configured as follows. That is, in the exhaust system valve of the present invention, a shaft that is rotated in the forward and reverse directions to open and close the valve body in the exhaust pipe is provided through the exhaust pipe so that at least one end side thereof is exposed from the exhaust pipe. A spring is disposed around the exposed portion of the shaft from the exhaust pipe so as to urge the shaft to rotate. Further, a leak gas guide tube is inserted between the exposed portion and the spring, and a base end portion of the leak gas guide tube includes an exhaust gas leak point leaking through the exhaust pipe penetrating portion of the shaft. , While being connected, the tip is open to the atmosphere. Furthermore, a shield is provided between the exhaust pipe and the spring so as to block radiant heat from the exhaust pipe to the spring. The shield is not limited to blocking all of the radiant heat from the exhaust pipe to the spring, but also includes a shield that blocks a part of the radiant heat.

  According to the heat shielding structure for the exhaust system valve spring having such a configuration, the spring is disposed around the exposed portion from the exhaust pipe of the shaft, and the exhaust gas leaks through the exhaust pipe penetrating portion of the shaft. It is prevented or suppressed that the exhaust gas is directly blown to the spring from the fact that the gas is guided to the tip end side of the shaft through the inner peripheral side of the spring by the leaked gas guide cylinder and released to the atmosphere.

  Further, since the leakage gas guide tube is inserted between the shaft and the spring, the radiant heat directed from the exposed portion of the shaft heated by the exhaust gas to a high temperature toward the spring is substantially blocked by the leakage gas guide tube. . For this reason, it is prevented or suppressed that the spring is heated by the radiant heat from the shaft.

  Further, since a shield is provided between the spring and the exhaust pipe so as to block the radiant heat from the exhaust pipe to the spring, the spring is prevented or suppressed from being heated by the radiant heat from the exhaust pipe. .

  Further, since the member provided between the spring and the exhaust pipe is a shield or the like that does not require a large space, the above structure prevents the spring from being heated or suppressed without increasing the size of the shaft in the longitudinal direction. Figured.

  In addition, since the exhaust system valve of the present invention can be implemented with a simple structure, the above-described prevention or suppression of heating of the spring can be realized at low cost.

  In the exhaust system valve according to the present invention, the exhaust pipe may be configured such that the exposed portion of the shaft and the leaked gas guide tube form an air pocket in the leaked gas guide tube when submerged. It extends downward or obliquely downward from the side.

  According to the exhaust system valve having such a configuration, when the exhaust system at the bottom of the vehicle on which this heat shield structure is mounted is submerged in a water reservoir or the like, an air reservoir is formed inside the leaked gas guide tube. Therefore, parts that are vulnerable to water immersion, such as bearings and labyrinths, disposed in the inner part of the leaked gas guide tube are protected.

  In the exhaust system valve according to the present invention, in any one of the above-described configurations, the shield is a container body that is opened downward or obliquely downward so as to form an air pocket therein when submerged.

  According to the exhaust system valve having such a configuration, when the exhaust system at the bottom of the vehicle on which the exhaust system valve is mounted is submerged in a water reservoir or the like, an air reservoir is formed inside the shield. Therefore, the springs arranged inside the shield, and the parts vulnerable to water immersion such as bearings and labyrinth, which are arranged in the inner part of the leakage gas guide cylinder, are protected.

  According to the exhaust system valve of the present invention, the spring energizing the shaft of the exhaust system valve is prevented or suppressed from being heated to a high temperature by the heat effect of the exhaust gas.

  Further, since the member provided between the spring and the exhaust pipe is a shield or the like that does not require a large space, there is no problem that the structure increases in the longitudinal direction of the shaft unlike the valve according to the conventional example. .

  Furthermore, since the exhaust system valve of the present invention can be implemented with a simple structure, the above-described prevention or suppression of the heating of the spring can be realized at low cost.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 to 5 show an exhaust heat recovery apparatus 1 having an exhaust system valve of the present invention. The exhaust heat recovery apparatus 1 is installed as a part of an exhaust system such as an automobile engine. 1 is a front view of the exhaust heat recovery apparatus 1, FIG. 2 is a cross-sectional view taken along the line AA of FIG. 1, FIG. 3 is a right side view of the exhaust heat recovery apparatus 1, and FIG. FIG. 3 is a sectional view taken along line BB in FIG.

<Description of exhaust heat recovery device>
The exhaust heat recovery apparatus 1 mainly includes an inner cylinder portion 2, a valve body (valve body) 3, cooling water passages 4a and 4b, heat recovery exhaust gas passages 5a and 5b, an outer cylinder portion 6 and the like. The inner cylinder part 2 and the outer cylinder part 6 are so-called exhaust pipes.

  An exhaust gas inlet 2a is formed at the upstream end of the exhaust system (hereinafter simply referred to as “upstream side”) of the inner cylinder portion 2 so as to be connected to an upstream component and to introduce exhaust gas from the upstream side. ing. On the other hand, a valve seat 2c is formed in the opening 2b at the end of the inner cylinder portion 2 on the downstream side of the exhaust system (hereinafter simply referred to as “downstream side”). The valve body 3 is detachably fitted here, and the opening 2b of the inner cylinder part 2 is opened and closed. In addition, on the peripheral side surface of the inner cylinder portion 2, a large number of communication holes 2 d that communicate the inner and outer spaces of the inner cylinder portion 2 are formed.

  The cooling water passages 4 a and 4 b and the heat recovery exhaust gas passages 5 a and 5 b are formed between the inner cylinder portion 2 and the outer cylinder portion 6. That is, the inner heat recovery exhaust gas flow path 5a, the inner cooling water flow path 4a, the outer heat recovery exhaust gas flow path 5b, and the outer cooling water flow path in order from the center toward the outer diameter direction on the outer peripheral side of the inner cylinder portion 2. 4b is formed. The inner cooling water flow path 4a and the outer cooling water flow path 4b are communicated with each other so that the cooling water can be circulated by the communication portion H at a plurality of locations.

  The outer cylinder portion 6 constitutes the outer peripheral wall of the outer cooling water flow path 4b and extends further downstream from the location where the valve body 3 is disposed. At the downstream end of the outer cylinder portion 6, there is formed a discharge port 6 a that is connected to an exhaust system constituent member on the downstream side of the exhaust heat recovery device 1 and exhausts exhaust gas that has passed through the outer cylinder portion 6. Has been. In addition, between the upstream side edge part of the outer cylinder part 6 and the outer peripheral surface of the inner cylinder part 2, it is the closing member 9, and the outer peripheral surface of the inner cylinder part 2 and the downstream edge part of the inner side cooling water flow path formation member 7 are connected. The gaps are respectively closed by the closing member 10, and the introduced exhaust gas is guided to a desired flow path.

  A shaft 12 for opening and closing the valve main body 3 is passed through the outer cylinder portion 6. For example, as shown in FIG. 2, the other part of the outer cylinder portion 6 is provided at the penetration portion of the outer cylinder portion 6 in the shaft 12 and the vicinity thereof, and the intersection portion between the extension line of the shaft 12 and the outer cylinder portion 6 and the vicinity thereof. Compared with this portion, a constricted portion 6A constricted inward is formed.

  On the other hand, a cooling water introduction hose 13 that communicates with the inner cooling water flow path 4a and the outer cooling water flow path 4b and introduces cooling water into these cooling water flow paths 4a and 4b is connected to the vicinity of the bottom of the outer cylinder portion 6. Yes. In addition, a cooling water discharge hose 14 is connected to the upper portion of the outer cylinder portion 6 so as to communicate with the outer cooling water flow path 4 b and discharge the heated cooling water.

  Hereinafter, a case where exhaust gas heat recovery is performed in the exhaust heat recovery apparatus 1 having the above-described configuration will be briefly described. The structure of the shaft 12 for opening and closing the valve body 3 will be described in detail after this description.

  When exhaust gas is introduced into the inner cylinder part 2 from the upstream side by the operation of the engine, if the valve body 3 is closed, the exhaust gas that has passed through the inner cylinder part 2 is shown in FIG. As described above, the air is guided to the inner heat recovery exhaust gas passage 5a through the communication hole 2d and flows in the direction of the arrow in FIG. The exhaust gas flowing through the inner heat recovery exhaust gas flow path 5a exchanges heat with the cooling water in the inner cooling water flow path 4a, and then reverses in the closing member 9 to reverse the outer heat recovery exhaust gas flow path 5b. Introduced into. Similarly, the exhaust gas flowing in the outer heat recovery exhaust gas flow path 5b also exchanges heat with the cooling water in the inner cooling water flow path 4a and the outer cooling water flow path 4b, while the outer heat recovery exhaust gas flow path. The gas passes through 5b and is discharged to an exhaust system constituent member on the downstream side connected to the discharge port 6a of the outer cylinder portion 6.

  The cooling water introduced into the cooling water flow paths 4a and 4b from the cooling water introduction hose 13 is heated by heat exchange with the exhaust gas flowing through the heat recovery exhaust gas flow paths 5a and 5b, and the cooling water discharge hose 14 is obtained. To the outside of the exhaust heat recovery device 1.

  When the exhaust heat recovery device 1 does not recover the heat of the exhaust gas, or when the amount of heat to be recovered is suppressed, the valve body 3 is opened. When the valve body 3 is opened, most of the exhaust gas led to the inner heat recovery exhaust gas flow path 5a through the communication hole 2d of the inner cylinder portion 2 is the opening 2b on the downstream side of the inner cylinder portion 2. And is discharged from the discharge port 6a of the outer cylinder portion 6 to the exhaust system components on the downstream side. At this time, since the exhaust gas introduced into the heat recovery exhaust gas passages 5a and 5b is greatly reduced, the amount of heat of the recovered exhaust gas is suppressed.

<Description of Exhaust System Valve According to First Embodiment>
Hereinafter, an exhaust system valve according to the first embodiment of the present invention will be described. As shown in FIGS. 2 and 3, one side of the valve body 3 is fixed to the shaft 12 by a fixing tool 16 such as a screw, and the shaft 12 is rotated in the forward and reverse directions, whereby the outer cylinder The valve body 3 in the portion 6 is configured to open and close.

  The shaft 12 is provided so as to penetrate the outer cylinder portion 6 so that one end side thereof is exposed from the outer cylinder portion 6 obliquely downward (for example, 45 degrees downward with respect to the horizontal direction). Here, the diagonally downward direction is a direction in a state where the exhaust system valve according to the embodiment of the present invention is mounted on the vehicle. The shaft 12 is accommodated in a shaft case 17 made of a cylindrical member provided between the constricted portions 6A and 6A of the outer cylinder portion 6, and is fixed to bearings 18 and 19 fixed near both ends in the shaft case 17. It is supported rotatably. A window portion 17 a for securing a movable region of the valve body 3 is formed in the intermediate portion of the shaft case 17.

  A labyrinth 21 that suppresses leakage of exhaust gas is fitted and attached to the outside of the bearing 18 on the exposed portion 12a side from the outer cylinder portion 6 of the shaft 12. On the other hand, the opening of the shaft case 17 on the side of the non-exposed portion 12a is sealed by the sealing cap 22 so that the exhaust gas does not leak out from the outer cylinder portion 6 through the opening. In addition, the shaft case 17 and the penetration part of the shaft case 17 of the outer cylinder part 6 are joined without gaps by welding work or the like so that the exhaust gas does not leak out from these boundaries.

  Around the exposed portion 12 a of the shaft 12, a torsion coil spring 20 (hereinafter simply referred to as “coil spring 20”) that urges the shaft 12 to rotate in the direction in which the valve body 3 is closed is disposed. As shown in FIG. 5, one end of the coil spring 20 is engaged with a spring engaging portion 26 formed in a first shield portion 25 a described later, and the other end of the coil spring 20 is the tip of the exposed portion 12 a of the shaft 12. Is engaged with a spring engaging portion 27 fixed to the head. In addition, the spring arrange | positioned around the exposed part 12a of the shaft 12 is not limited to the coil spring 20, As long as it is a spring which can urge | bias the shaft 12, you may employ | adopt another spring.

  A leakage gas guide tube 23 is inserted between the coil spring 20 and the shaft 12. The base end portion of the leakage gas guide tube 23 is connected to the periphery of the leakage portion so as to contain the leakage portion of the exhaust gas that leaks from the outer cylinder portion 6 through the through portion of the outer cylinder portion 6 of the shaft 12. ing. Here, since the exhaust gas passes through the gap between the shaft 12, the bearing 18 and the labyrinth 21 from the inside of the outer cylindrical portion 6, it leaks from the opening at the obliquely lower end portion of the shaft case 17, so that the exhaust gas leakage location Is an opening at an obliquely lower end of the shaft case 17. Therefore, the base end portion of the leaking gas guide tube 23 is connected to the obliquely lower end portion of the shaft case 17 so as to include the opening.

  The connection between the base end portion of the leaked gas guide tube 23 and the leaked portion of the exhaust gas is performed by, for example, welding work so that no gas leaks from the connecting portion. On the other hand, the tip of the leakage gas guide tube 23 is open and open to the atmosphere.

  The leaking gas guide tube 23 is extended obliquely downward from the outer tube portion 6 side together with the exposed portion 12a of the shaft 12 so that an air pocket is formed inside the leaked gas guide tube 23. The diagonally downward direction is a direction in a state where the exhaust system valve according to the embodiment of the present invention is mounted on the vehicle.

  A shield 25 is provided between the coil spring 20 and the outer cylinder part 6 so as to block radiant heat from the outer cylinder part 6 to the coil spring 20. The shield 25 includes a first shield part 25a and a second shield part 25b.

  The first shield part 25 a is joined to the outer peripheral part of the leakage gas guide cylinder 23 at a position between the coil spring 20 and the outer cylinder part 6. It is desirable that the first shield portion 25a is spaced a sufficient distance from the bearing 18 in the extending direction of the shaft 12 in order to suppress the influence of heat conduction from the outer cylinder portion 6, the shaft case 17 and the like. In the present embodiment, the first shield portion 25a is formed of a thin annular member, and the joint portion between the thin annular member and the leaked gas guide tube 23 has an L-shaped cross section for the purpose of reinforcement. The annular member 24 is fixed by welding.

  The second shield part 25b is integrally joined to the first shield part 25a. In addition, the second shield portion 25b is configured such that, while the vehicle equipped with the exhaust system valve according to the embodiment of the present invention is running, the water repellent water, the water repellent mud and the like from the front wheels of the vehicle are subjected to the coil spring 20, The coil spring 20 and the shaft 12 are surrounded except for the opening 25c which is obliquely below the rear so as not to collide with the shaft 12 and the like. Of course, when the purpose is only to shield the radiant heat from the outer tube portion 6 to the coil spring 20, the shield 25 may be formed only between the outer tube portion 6 and the coil spring 20. The rear obliquely downward direction is a direction in a state where the exhaust system valve according to the embodiment of the present invention is mounted on the vehicle.

  Since the opening 25c is formed obliquely below the second shield part 25b, part of the radiant heat from the outer cylinder part 6 enters the coil spring 20 from the opening 25c. Since the outer cylinder portion 6 side of the coil spring 20 having a large heat effect is blocked by the first shield portion 25a, the heat damage to the coil spring 20 is sufficiently suppressed.

  The exposed portion 12 a of the shaft 12 is provided with an actuator connection portion 12 b that works in conjunction with the actuator 28. The actuator connecting portion 12b is made of an abutting member fixed to the shaft 12 so that the telescopic rod 28a of the cylinder-type actuator 28 can abut at the eccentric position of the shaft 12. The second shield part 25 b is formed with an insertion hole for the telescopic rod 28 a, and the actuator 28 is fixed to the outer cylinder part 6 via a bracket 29.

  When the telescopic rod 28a of the actuator 28 is extended, the tip of the telescopic rod 28a presses the actuator connecting portion 12b, and the valve body 3 opens the shaft 12 against the rotational biasing force of the coil spring 20. Rotate to When exhaust gas is introduced into the inner cylinder part 2 in this state, most of the exhaust gas passes through the inner cylinder part 2 and is connected to the outlet 6a of the outer cylinder part 6 on the downstream side. Is discharged. At this time, the main flow of the exhaust gas is formed substantially along the central axis of the inner cylinder portion 2.

  On the other hand, when the telescopic rod 28 a of the actuator 28 is contracted, the shaft 12 is rotated in the direction in which the valve body 3 is closed by the biasing force of the coil spring 20. When exhaust gas is introduced into the inner cylinder part 2 in this state, most of the exhaust gas passes through the communication hole 2d and the heat recovery exhaust gas flow paths 5a and 5b in this order, and then is exhausted in the outer cylinder part 6. A flow path is formed toward the outlet 6a. At this time, since the constricted portion 6A is formed in the outer cylinder portion 6, the main flow of the exhaust gas is easily formed at a position away from the constricted portion 6A. For example, in the cross-sectional view of FIG. 2, the main flow of the exhaust gas is easily formed on the lower right side from the center of the inner cylinder portion 2. As a result, a main flow of exhaust gas is formed at a position away from the shaft 12 spanned between the constricted portions 6A and 6A, so that the main flow of exhaust gas does not blow against the shaft 12 and the temperature rise of the shaft 12 is suppressed. Is done.

  Next, the leakage of exhaust gas from the outer cylinder portion 6 will be described. Regardless of the open / closed state of the valve body 3, the exhaust gas enters from the window portion 17 a of the shaft case 17 to the bearing 18 side of the shaft 12 and passes through the clearance between the shaft 12 and the bearing 18 and the clearance between the labyrinth 21 and exits. It leaks to the outside of the cylinder part 6.

  However, the leaked exhaust gas is guided by the leaked gas guide cylinder 23 connected to the leak location, passes through the inside of the coil spring 20, and opens at the tip 23a of the leaked gas guide cylinder 23 and the opening of the shield 25. It is opened to the atmosphere through 25c. For this reason, the exhaust gas leaked to the coil spring 20 is avoided or suppressed.

  In addition, although the front-end | tip part of the leaking gas guide cylinder 23 shown in figure has entered into the outer cylinder part 6 side a little from the edge part of the coil spring 20, the leaking exhaust gas mainly extends in the extension line direction of the leaking gas guide cylinder 23 Therefore, there is little possibility that the exhaust gas directly blows against the end of the coil spring 20 and heats the coil spring 20 to a high temperature. If the length of the leakage gas guide cylinder 23 is slightly shorter than this, the exhaust gas may directly blow against the end of the coil spring 20. The temperature is greatly reduced, and the range of the coil spring 20 to which the exhaust gas blows is small, so that the temperature rise of the coil spring 20 is sufficiently suppressed.

  Further, the exhaust gas leaking into the leaked gas guide tube 23 is not in the vicinity of the main flow of the exhaust gas, but is introduced from the end of the shaft case 17 at a position away from the main flow of the exhaust gas, and the temperature is relatively low. Exhaust gas. For this reason, the temperature rise of the leakage gas guide cylinder 23 is suppressed, and the heat radiation from the leakage gas guide cylinder 23 to the coil spring 20 that can be slightly affected is also suppressed.

  Further, the shaft 12 in the outer cylinder portion 6 is heated to a high temperature by the exhaust gas, and heat radiation is generated from the exposed portion 12a of the shaft 12 that has become a high temperature by heat conduction. However, since the leaked gas guide tube 23 is inserted between the coil spring 20 and the shaft 12, the heat radiated from the exposed portion 12 a is blocked by the leaked gas guide tube 23. As a result, the coil spring 20 is prevented or suppressed from being heated by the radiant heat from the exposed portion 12a of the shaft 12.

  Further, the heat of the exhaust gas heats the outer cylinder portion 6 to a high temperature, and heat radiation is generated from the outer cylinder portion 6 toward the coil spring 20. However, since the shield 25 is provided between the coil spring 20 and the outer cylinder part 6, the heat radiated from the outer cylinder part 6 is blocked by the shield 25. As a result, the coil spring 20 is prevented or suppressed from being heated by the heat radiation from the outer cylinder portion 6.

  By the way, according to the exhaust system valve | bulb which concerns on the 1st Embodiment of this invention, in addition to preventing the thermal influence of the exhaust gas to the coil spring 20, there exist the following advantages. That is, as already described, since the exposed portion 12a of the shaft 12 and the leaked gas guide tube 23 extend obliquely downward from the outer tube portion 6 side, the exhaust system including this exhaust system valve is water. Even when submerged in the reservoir, an air reservoir is formed in the leaked gas guide tube 23. Therefore, it is possible to prevent water from entering the bearing 18, the labyrinth 21, and the like disposed in the inner part of the leakage gas guide cylinder 23, and further to prevent water from entering the exhaust pipes 2 and 6. .

  In order to obtain such an advantage, the exposed portion 12a of the shaft 12 and the leaked gas guide tube 23 are downward or obliquely downward from the outer tube portion 6 side so that an air pocket is formed in the leaked gas guide tube 23 when submerged. The extension direction is not limited to 45 degrees obliquely downward as shown in the drawing. In addition, the above-described downward or obliquely downward direction is a direction in a state where the exhaust system valve according to the embodiment of the present invention is mounted on the vehicle.

<Description of Exhaust System Valve According to Second Embodiment>
The second embodiment of the present invention will be described below. In addition, about the structure similar to 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  As shown in FIGS. 6-9, in the exhaust system valve | bulb which concerns on 2nd Embodiment, the shape of the shield 30 differs from the shield 25 which concerns on 1st Embodiment.

  That is, the second shield part 30b of the second embodiment surrounds the entire outer periphery of the coil spring 20, and the opening part 30c that is obliquely lower rearward than the second shield part 25b of the first embodiment. Is biased toward the tip end side of the shaft 12 (exposed portion 12a side).

  For this reason, the radiant heat from the outer cylinder part 6 which became high temperature by the heat of exhaust gas to the coil spring 20 can be completely shielded by the first shield part 25a and the second shield part 30b. .

  In addition, the shield 30 has the opening 30c obliquely downward so that when the exhaust system including the exhaust system valve according to the second embodiment is submerged in a water reservoir or the like, an air reservoir is formed therein. It is a container body that is open. For this reason, inundation of the coil spring 20 is prevented in addition to the bearing 18 and the labyrinth 21 of the shaft 12 when the exhaust system is submerged. The shield 30 only needs to be a container body that opens downward or obliquely downward so that an air pocket is formed inside the shield 30 when submerged, and the position of the opening 30c is formed obliquely downward as shown. It is not limited to that. The downward or diagonally downward direction is a direction when the exhaust system valve according to the present embodiment is mounted on a vehicle.

  In the above, the case where the exhaust system valve according to the first and second embodiments of the present invention is applied to the exhaust heat recovery devices 1 and 1A has been described as an example. However, the exhaust system valve according to the present invention is The present invention is not limited to the exhaust heat recovery device, and can be applied to an apparatus that opens and closes an exhaust system valve by rotation of a shaft and includes a spring that urges the shaft to rotate. For example, the present invention can be applied to an exhaust gas purifying apparatus including such a shaft and a spring.

  The present invention can be applied to an exhaust system valve provided in an exhaust system of an internal combustion engine or the like provided with a coil spring that opens and closes a valve body by rotation of a shaft and urges the shaft to rotate.

1 is a front view of an exhaust heat recovery apparatus including an exhaust system valve according to a first embodiment of the present invention. It is AA sectional drawing of FIG. 1 is a right side view of an exhaust heat recovery apparatus including an exhaust system valve according to a first embodiment of the present invention. It is a longitudinal cross-sectional view of FIG. It is BB sectional drawing of FIG. It is a front view of an exhaust heat recovery apparatus provided with the exhaust system valve | bulb which concerns on the 2nd Embodiment of this invention. It is CC sectional drawing of FIG. It is a right view of an exhaust heat recovery apparatus provided with the exhaust system valve | bulb which concerns on the 2nd Embodiment of this invention. It is an arrow D auxiliary projection figure of FIG.

Explanation of symbols

6 Outer tube (exhaust pipe)
3 Valve body 12 Shaft 12a Exposed portion 20 Coil spring (spring)
23 Leakage gas guide tube 25, 30 Shield 25c, 30c Shield opening

Claims (3)

A shaft that is provided through the exhaust pipe so that at least one end side is exposed from the exhaust pipe, and is rotated in the forward and reverse directions to open and close the valve body in the exhaust pipe;
A spring disposed around the exposed portion of the shaft from the exhaust pipe so as to urge the shaft;
The base end portion is connected so as to include the leaked portion of the exhaust gas that is inserted between the exposed portion and the spring and leaks through the exhaust pipe penetrating portion of the shaft, while the distal end portion is opened to the atmosphere. A leaking gas guide tube;
A shield provided between the exhaust pipe and the spring so as to block radiant heat from the exhaust pipe to the spring;
An exhaust system valve comprising:   The exposed portion of the shaft and the leaked gas guide tube extend downward or obliquely downward from the exhaust pipe side so that an air pocket is formed in the leaked gas guide tube when submerged. The exhaust system valve according to claim 1.   3. The exhaust system valve according to claim 1, wherein the shield is a container body that is opened downward or obliquely downward so as to form an air pocket therein when submerged.

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