JP2016095009A - Butterfly valve and exhaust system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve sealing property in a butterfly valve using a seal ring.SOLUTION: The butterfly valve includes: a housing with a flow channel through which fluid passes; a rotary valve stem; a discoid valve body provided inside the flow channel, having an outer peripheral edge formed with a groove and connected to the valve stem; the seal ring having a gap and fitted into the groove; and a fixing member provided in a position of the gap in the groove and having a height that is variable relative to the valve body in a radial direction of the valve body.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a technique for improving sealing performance in a butterfly valve using a seal ring.

  A butterfly valve is known as a valve for controlling the flow rate of fluid. For example, Patent Documents 1 and 2 disclose a technique using a butterfly valve as an EGR valve used in an exhaust gas recirculation (EGR) system that reintakes a part of exhaust gas in an internal combustion engine for automobiles. doing. Patent Documents 1 and 2 disclose a structure in which a groove is provided on the outer peripheral edge of the valve body and a seal ring is fitted in this groove in order to improve the sealing performance (air tightness) between the valve body and the housing. .

  Here, the seal ring is not a perfect ring shape, but has a C-shape with a notch (a so-called joint) in part. In order to prevent the seal ring from rotating with respect to the valve body, a non-rotating pin is provided at the position of the notch (Patent Document 1: Non-rotating pin 75 in FIG. 6A, Patent Document 2: FIG. 6 shows a ring movement restricting portion 46).

JP 2008-223505 A JP 2014-185678 A

  The height of the non-rotating pin in the radial direction of the valve body is designed so that the gap with the housing is small. However, if the pin protrudes beyond the seal ring, the housing may be damaged. Therefore, the height of the pin has to be designed to a dimension that creates a gap between the pin and the housing. In this case, there is a problem that the gas leaks from this gap and the sealing performance deteriorates.

  On the other hand, this invention provides the technique which improves a sealing performance in the butterfly valve using a seal ring.

  The present invention provides a housing having a flow path through which a fluid passes, a rotating valve shaft, an outer peripheral edge having a groove formed therein and connected to the valve shaft. A shaped valve body, a seal ring having a joint, fitted in the groove, a fixing member provided at a position of the joint in the groove and having a variable height relative to the valve body in the radial direction of the valve body; A butterfly valve is provided.

  The butterfly valve may include a spring provided between the outer peripheral edge and the fixing member, and the height of the fixing member may be changed by the action of the spring.

  The butterfly valve may include a magnet provided in the housing, the fixing member may be made of a ferromagnetic material, and the height of the fixing member may be changed by the action of the magnet.

  The butterfly valve is provided in the valve body and has a hole penetrating from the high-pressure side surface of the fluid to the position of the fixing member, and the height of the fixing member varies depending on the fluid flowing into the hole. May be.

  The fixing member may be formed of a material having a thermal expansion coefficient larger than that of the seal ring, and the height of the fixing member may change due to a temperature increase of the fixing member.

  The normal direction of the disc of the valve body may be perpendicular to the axial direction of the valve shaft.

  The said valve body may have a control part which controls the movement of the said fixing member in the circumferential direction of the said valve body to the range which does not reach the inflow port and the outflow port of the said fluid.

  The present invention also provides an exhaust system having an exhaust pipe for flowing exhaust gas of an internal combustion engine, and any one of the butterfly valves attached in the middle of the exhaust pipe.

  ADVANTAGE OF THE INVENTION According to this invention, a sealing performance can be improved in the butterfly valve using a seal ring.

The figure which illustrates the composition of intake and exhaust system 1000 concerning one embodiment 1 is a perspective view of a valve assembly 1 according to an embodiment. The perspective view which illustrates the structure of the valve stem and valve body in butterfly valve 4 Exploded perspective view of butterfly valve 4 The figure which illustrates the relationship between the abutment 441 and the fixing member 45 The figure which shows the example of the mechanism which makes the height of the fixing member 45 variable. The figure which shows another example of the mechanism which makes the height of the fixing member 45 variable. The figure which shows another example of the mechanism which makes the height of the fixing member 45 variable. The figure which shows another example of the mechanism which makes the height of the fixing member 45 variable. XX sectional view of FIG. 2 is shown. Enlarged view of area IX in Figure 9 Sectional view of the valve assembly 1 in the half-open state The figure which shows another example of the movement control range of the fixing member 45

  FIG. 1 is a diagram illustrating a configuration of an intake / exhaust system 1000 according to an embodiment. The intake / exhaust system 1000 is a system that controls intake / exhaust to the engine 2000. In this example, engine 2000 is an automobile diesel engine. The intake / exhaust system 1000 is a so-called EGR system (EGR device) that recirculates a part of the exhaust gas to the intake system. The intake / exhaust system 1000 includes an intake system 11, an exhaust system 12, an HPL (High Pressure Loop) -EGR system 13, and an LPL (Low Pressure Loop) -EGR system 14.

  The intake system 11 supplies an air-fuel mixture to the engine 2000. The intake system 11 includes an intake-side turbo bypass valve 111, an intercooler switching valve 112, an intercooler 113, and a throttle valve 114.

  The exhaust system 12 discharges exhaust gas from the engine 2000. The exhaust system 12 includes an exhaust-side turbo bypass valve 121, an exhaust brake valve 122, a DPF (Diesel Particulate Filter) 123, and an exhaust throttle valve 124.

  A first turbocharger 15 and a second turbocharger 16 are provided between the intake system 11 and the exhaust system 12.

  The HPL-EGR system 13 returns a part of the exhaust to the intake system 11. The HPL-EGR system 13 is provided between the exhaust side of the engine 2000 and the intake system 11 (specifically, the downstream side of the throttle valve 114). The HPL-EGR system 13 includes an EGR cooler switching valve 131, an HPL-EGR valve 132, and an EGR cooler 133.

  The LPL-EGR system 14 returns a part of the exhaust gas to the intake system 11. The LPL-EGR system 14 is provided between the exhaust system 12 (specifically, the downstream side of the DPF 123) and the intake system 11 (specifically, the upstream side of the second turbocharger 16). The LPL-EGR system 14 includes an LPL-EGR valve 141 and an EGR cooler 142.

  FIG. 2 is a perspective view of the valve assembly 1 according to an embodiment. The valve assembly 1 is a valve used in the intake / exhaust system 1000, for example, a valve used as the exhaust-side turbo bypass valve 121. The valve assembly 1 includes a drive unit 2, a link mechanism unit 3, and a butterfly valve 4. Hereinafter, for the sake of explanation, the direction is defined as follows. In the butterfly valve 4, upstream and downstream in the fluid flow direction are referred to as “front” and “rear”, respectively. The top, bottom, left and right when facing backward from the front toward the butterfly valve 4 are referred to as “upper”, “lower”, “left”, and “right”. This definition is for convenience of explanation, and does not limit the direction and position where the valve assembly 1 is installed in the system.

  The butterfly valve 4 includes a housing 41, a valve shaft (not shown in FIG. 2), and a valve body 43. The housing 41 includes a housing body 411 and a sleeve 412. The housing body 411 is made of, for example, stainless steel and has a rectangular parallelepiped shape. The housing body 411 has a hole (flow path) extending in the front-rear direction. Fluid passes through this hole. In FIG. 2, the direction in which the fluid flows is indicated by arrows. The sleeve 412 is formed of stainless steel, for example, and has a cylindrical shape. The sleeve 412 is fitted in the hole of the housing body 411.

  FIG. 3 is a perspective view illustrating the structure of the valve shaft and the valve body in the butterfly valve 4, and FIG. 4 is an exploded perspective view of the butterfly valve 4. The butterfly valve 4 includes a valve shaft 42, a valve body 43, a seal ring 44, and a fixing member 45.

  The valve shaft 42 is made of stainless steel, for example, and has a cylindrical shape (round bar shape). In the valve shaft 42, a part of the side surface is cut to connect the valve body 43 to form a flat portion 421.

  The valve body 43 is made of, for example, stainless steel and has a disk shape. That is, the valve body 43 has a flat surface 431, a flat surface 432, and an outer peripheral edge 433. Grooves 434 (hatched portions in FIG. 4) are formed in the outer peripheral edge 433. The groove 434 is formed along the outer peripheral edge 433 and is circular when viewed from the front. Further, the groove 434 extends straight along the outer peripheral edge 433 when viewed from above, below, left, or right. The valve shaft 42 and the valve body 43 are fixed to each other by a bolt 46 on the flat portion 421 and the flat surface 432.

  The seal ring 44 is formed of stainless steel, for example, and has an annular shape. However, the seal ring 44 does not have a complete annular shape, and the ring is partially cut and a gap (gap) is formed. That is, the seal ring 44 has a C shape. The portion where the ring is cut is referred to as a joint 441. When the abutment 441 is formed, the gap at the abutment becomes a margin, and the seal ring 44 is easily elastically deformed. Note that the seal ring 44 and the valve body 43 may be formed of different materials depending on required characteristics. For example, the seal ring 44 may be formed of SUS631J1, and the valve body 43 may be formed of SUS303.

  The fixing member 45 functions as a stopper that prevents the seal ring 44 from rotating with respect to the valve body 43. The fixing member 45 is attached to the valve body 43 at a position corresponding to the joint 441 in the groove 434. The fixing member 45 is a pin that is formed of, for example, stainless steel and has a column shape with a predetermined cross-sectional shape (for example, a circle). In this example, the width of the groove 434 is thick only at the portion where the fixing member 45 is attached, and the other portion is formed narrower than the width of the fixing member 45 (for example, the diameter of the cross-sectional circle). That is, the narrow portion of the groove 434 functions as a restricting portion that restricts the movement of the fixing member 45 in the lateral direction (the circumferential direction of the valve body 43).

  In this example, the circumferential length of the wide portion of the groove 434 is approximately the same as the width of the fixing member 45. That is, the fixing member 45 hardly moves in the lateral direction (the circumferential direction of the valve body 43).

  FIG. 5 is a diagram illustrating the relationship between the joint 441 and the fixing member 45. The upper part of FIG. 5 shows a cross section of the valve element 43 and the seal ring 44 as viewed from the front (the VV cross section of the lower part of FIG. 5). The lower view of FIG. 5 is a view of the valve body 43 and the seal ring 44 as viewed from below. That is, the lower diagram of FIG. 5 shows the shape of the abutment 441 and the positional relationship with the fixing member 45 as seen from the radial direction of the seal ring 44. In this figure, the groove 434 and the seal ring 44 are drawn large for explanation. The joint 441 is formed by one end (end portion 442) and the other end (end portion 443) of the seal ring 44. The seal ring 44 is not fitted to the bottom surface of the groove 434, and a gap (gap G3 in FIG. 9) is provided between the bottom surface of the seal ring 44 and the bottom surface of the groove 434. A part of the fixing member 45 is fitted into the valve body 43. In this example, the fixing member 45 is not completely fixed to the valve body 43 and can move in the radial direction of the valve body 43. The valve body 43 has a hole (concave portion) for attaching a fixing member. The seal ring 44 is not entirely fitted in the groove 434, and a part of the seal ring 44 protrudes from the groove 434. As an example, the outer diameter of the seal ring 44 is 40 to 70 mm, the height (the length in the radial direction) d1 is 1.8 to 2.0 mm, and the height d2 of the portion protruding from the groove 434 is included. Is 0.8 to 1.1 mm.

  In the present embodiment, the height of the fixing member 45 is variable. The height here refers to a length from a predetermined reference surface (for example, the bottom surface of the groove 434) of the valve body 43 in the radial direction of the valve body 43. Hereinafter, four examples of a mechanism that makes the height of the fixing member 45 variable will be described.

(1) Example 1
FIG. 6 is a diagram illustrating an example of a mechanism that makes the height of the fixing member 45 variable. In this example, the butterfly valve 4 has a spring 47. The spring 47 is provided in a position corresponding to the fixing member 45 in the groove 434, that is, below the fixing member 45. The spring 47 is a compression spring, for example, a helical spring. For example, even if the inner diameter of the hole of the housing 41 changes due to the temperature change of the butterfly valve 4, the fixing member 45 is pressed against the housing 41 by the force of the spring 47, and no gap is generated (in FIG. 6, the fixing member is not formed). It is illustrated that there is a gap even after 45 approaches the housing 41. The same applies to the following drawings).

  The fixing member 45 has a relatively thin end on the housing 41 side and a relatively thick end on the valve body 43 side, and has a recess 451 near the center. The valve body 43 has a claw 436 near the opening (upper part) of the groove 434. The claw 436 engages with the recess 451 and restricts the movement of the fixing member 45 toward the housing 41 (the fixing member 45 is prevented from being removed from the groove 434). The claw 436 is provided only at the position where the fixing member 45 is attached in the groove 434.

(2) Example 2
FIG. 7 is a diagram illustrating another example of a mechanism that makes the height of the fixing member 45 variable. In this example, the housing 41 has a magnet 413. The fixing member 45 is made of a ferromagnetic material (for example, SUS400 stainless steel). The magnet 413 is provided in the housing 41 at a position corresponding to the position of the valve body 43 when the valve is closed. When the valve is closed, the fixing member 45 is not affected by the magnet 413, and a gap is generated between the fixing member 45 and the housing 41. When the valve is closed, the fixing member 45 is attracted to the magnet 413 and no gap is generated.

  According to this example, the fixing member 45 is in close contact with the housing 41 only in the closed position, that is, in the vicinity of the magnet 413, and when the other position, that is, the valve is open, the fixing member 45 is not necessarily in close contact with the housing 41. Not. Therefore, the possibility that the housing 41 or the fixing member 45 is damaged is reduced as compared with the example in which the fixing member 45 is in close contact with the housing 41 regardless of whether the valve is open or closed as in Example 1. it can.

(3) Example 3
FIG. 8 is a diagram showing still another example of a mechanism that makes the height of the fixing member 45 variable. In this example, the valve body 43 has a hole 435. The hole 435 penetrates from a surface (flat surface 431) positioned on the high pressure side when the valve is closed to a position corresponding to the fixing member 45 in the groove 434, that is, below the fixing member 45. When the valve is closed, the fluid in the flat surface 431 becomes high pressure, and the fluid flows into the hole 435. The fixing member 45 is pressed against the housing 41 by the fluid pressure. When the valve is opened, the pressure of the fluid on the flat surface 431 decreases, and the pressure for pressing the fixing member 45 against the housing 41 also decreases.

  In this example as well as in Example 2, the fixing member 45 is in close contact with the housing 41 only when the valve is closed, and the fixing member 45 is not necessarily in close contact with the housing 41 when the valve is open. . Therefore, the possibility that the housing 41 or the fixing member 45 is damaged is reduced as compared with the example in which the fixing member 45 is in close contact with the housing 41 regardless of whether the valve is open or closed as in Example 1. it can.

(4) Example 4
FIG. 9 is a diagram showing still another example of a mechanism that makes the height of the fixing member 45 variable. In this example, the fixing member 45 is formed of a material having a thermal expansion coefficient larger than that of the seal ring 44. In this example, the fixing member 45 is fixed to the valve body 43 by press-fitting, for example. In Examples 1 to 3, the fixing member 45 is not fixed to the valve body 43 and is movable in the radial direction. FIG. 9A shows the positional relationship between the fixing member 45 and the seal ring 44 at a low temperature, specifically at room temperature. At a low temperature, the fixing member 45 is fixed in a state where the height is lower than the seal ring 44. That is, a gap is generated between the fixing member 45 and the housing 41 at a low temperature. FIG. 9B shows the positional relationship between the fixing member 45 and the seal ring 44 at a high temperature. When the temperature rises from FIG. 9A, the fixing member 45 and the seal ring 44 are thermally expanded. At this time, since the fixing member 45 has a higher coefficient of thermal expansion, the fixing member 45 extends more than the seal ring 44. For this reason, the height of the fixing member 45 is higher than that of the seal ring 44.

  For example, when used in a system that becomes hot during operation, such as an exhaust system of an engine, the fixing member 45 is pressed against the housing 41 only during operation, and a gap is generated between the fixing member 45 and the housing 41 during non-operation. That is, the possibility that the housing 41 or the fixing member 45 is damaged can be reduced as compared with the structure in which the fixing member 45 is pressed against the housing 41 regardless of whether it is in operation or not.

  Refer to FIG. 2 again. The drive unit 2 rotates the valve shaft 42 (that is, drives the valve shaft 42). The drive unit 2 includes a motor 21 and a bracket 22. The motor 21 is fixed to the bracket 22. The link mechanism unit 3 transmits driving force (rotational force) from the motor 21 to the valve shaft 42. The link mechanism unit 3 connects the rotating shaft (not shown) of the motor 21 and the valve shaft 42.

  FIG. 10 is a sectional view taken along line XX in FIG. In this figure, the butterfly valve 4 is fully closed. In this state, the valve body 43 is located in front of the valve shaft 42 (upstream side). That is, the radial center O2 of the valve body 43 is located forward with respect to the axis O1 of the valve shaft 42.

  A hole serving as a fluid path through which a fluid passes is formed in the sleeve 412. A sliding surface 4121 is formed on a part of the wall surface of the hole. The sliding surface 4121 is a surface that slides with the valve body 43 (seal ring 44), and has a part of a spherical surface with a radius of curvature r1. The curvature radius r <b> 1 is a length corresponding to the radius of the valve body 43 including the seal ring 44. The sliding surface 4121 is formed upstream of the axis O1 when viewed from above. On the downstream side of the axis O1, the hole of the sleeve 412 is constant or has a taper widening toward the downstream.

FIG. 11 is an enlarged view of a region IX in FIG. The seal ring 44 is formed on the outer peripheral edge 4 of the valve body 43.
33 is fitted in a groove 434 formed in 33. In this example, the cross-sectional shape of the seal ring 44 is a rectangle. In this example, the seal ring 44 is not completely pushed into the groove 434 (the seal ring 44 and the bottom surface of the groove 434 are not in contact), and the seal ring 44 and the groove 434 are not in contact with each other. There is a gap G3 between the bottom surface. If there is a gap G3, this becomes a margin, and the seal ring 44 is more easily elastically deformed.

  Refer to FIG. 10 again. Ideally, the axis O <b> 1 of the valve shaft 42 passes through the center of the sphere that forms the sliding surface 4121. Further, ideally, the radius of curvature r1 of the sliding surface 4121 and the distance from the axis O1 of the valve shaft 42 to the outer peripheral edge of the valve body 43 (seal ring 44) are the same. In such an ideal state, the outer peripheral edge of the valve body 43 and the sliding surface 4121 do not shift and contact with no gap.

  However, in actuality, due to various factors such as the shape accuracy of the valve body 43 and the sliding surface 4121, the assembly error between the valve shaft 42 and the valve body 43, and the thermal contraction of the valve body 43 and the housing 41, the valve body 43 There is a deviation between the outer peripheral edge of the lens and the sliding surface 4121.

  The seal ring 44 of this embodiment can be elastically deformed from an unloaded state by a gap with the groove 434. In a portion where the distance between the axis O1 and the sliding surface 4121 is shorter than the design value, the seal ring 44 is elastically deformed so that the sliding between the valve element 43 and the sliding surface 4121 is not impaired. Can do. That is, in the fully closed state, the sliding surface 4121 can be brought into contact with the entire circumference of the outer peripheral edge of the seal ring 44. A contact portion between the seal ring 44 and the sliding surface 4121 is illustrated as a seal portion S.

  FIG. 12 shows a cross-sectional view of the valve assembly 1 in the half-open state. FIG. 12 shows the same cross section as FIG. In this state, the valve body 43 is inclined as compared with the fully opened state, and the fluid path A is partially opened. The outer peripheral edge of the valve body 43 is in contact with the sliding surface 4121 at a part of the upper and lower portions. In other words, the upper and lower portions of the seal ring 44 are supported by the sliding surface 4121. The same applies to the fully opened state.

  The present invention is not limited to the above-described embodiment, and various modifications can be made. Hereinafter, some modifications will be described. A plurality of the following modifications may be used in combination.

  FIG. 13 is a diagram illustrating another example of the movement restriction range of the fixing member 45. The movement restriction range of the fixing member 45 is not limited to that described in the embodiment. The fixing member 45 may be movable in the lateral direction. However, if the fixing member 45 reaches the support portion 414 or the support portion 415 that supports the valve shaft 42 in the housing 41, that is, the support shaft 414 or the support portion 415, the support portion 414 or the support portion 415 may be damaged. is there. Therefore, it is preferable that the movable range of the fixing member 45 is restricted to a range (a range A in the drawing) in which the housing 41 does not reach the hole through which the valve shaft 42 passes, that is, the support portions 414 and 415 that support the valve shaft 42. .

  The shape of the fixing member 45 is not limited to that exemplified in the embodiment. For example, the fixing member 45 may be a quadrangular prism.

  The structure of the intake / exhaust system 1000 is not limited to that illustrated in FIG. As long as a part of the exhaust from the engine 2000 is recirculated to the intake pipe, the specific structure of the intake / exhaust system 1000 may be any. Engine 2000 is not limited to a diesel engine for automobiles. It may be an engine used for applications other than automobiles, such as ships, and may be a gasoline engine.

  The use of the valve assembly 1 is not limited to the exhaust-side turbo bypass valve 121 of the intake / exhaust system 1000. It may be used for other valves of the intake / exhaust system 1000. Further, the valve assembly 1 may be used in an exhaust system (exhaust device) other than the EGR system. In another example, the valve assembly 1 is not limited to one that controls the flow of gas (eg, air-fuel mixture and exhaust), and may be used for applications that control the flow of liquid or gas.

  The materials of the components of the valve assembly 1 are not limited to those described in the embodiment. Each of the component parts may be formed of a single metal such as aluminum or iron, an alloy thereof, or a resin other than stainless steel. Further, the shapes of the valve assembly 1 and its components are not limited to those illustrated in the embodiment. For example, the method of joining the valve shaft 42 and the valve body 43 is not limited to the method using the bolt 46. Moreover, the size demonstrated by embodiment is an example to the last.

DESCRIPTION OF SYMBOLS 1000 ... Intake / exhaust system 11 ... Intake system 111 ... Intake side turbo bypass valve 112 ... Intercooler switching valve 113 ... Intercooler 114 ... Throttle valve 12 ... Exhaust system 121 ... Exhaust side turbo bypass valve 122 ... Exhaust brake valve 123 ... DPF
124 ... Exhaust throttle valve 13 ... HPL-EGR system 131 ... EGR cooler switching valve 132 ... HPL-EGR valve 133 ... EGR cooler 14 ... LPL-EGR system 141 ... LPL-EGR valve 142 ... EGR cooler 15 ... First turbocharger 16 ... Second turbocharger engine 2000
Valve assembly 1
DESCRIPTION OF SYMBOLS 2 ... Drive part 3 ... Link mechanism part 4 ... Butterfly valve 41 ... Housing 411 ... Housing main body 412 ... Sleeve 413 ... Magnet 414 ... Support part 415 ... Support part 42 ... Valve shaft 421 ... Flat part 43 ... Valve body 431 ... Flat surface 432 ... Flat surface 433 ... Outer peripheral edge 434 ... Groove 435 ... Hole 436 ... Claw 44 ... Seal ring 441 ... Abutment 442 ... End part 443 ... End part 45 ... Fixing member 451 ... Depression 46 ... Bolt 47 ... Spring

Claims (8)

A housing having a flow path through which fluid passes;
A rotating valve stem,
A disc-shaped valve body provided inside the flow path, having an outer peripheral edge formed with a groove, and connected to the valve shaft;
A seal ring having a joint and fitted in the groove;
A butterfly valve comprising: a fixing member provided at a position of the joint in the groove and having a variable height relative to the valve body in a radial direction of the valve body. A spring provided between the outer peripheral edge and the fixing member;
The butterfly valve according to claim 1, wherein the height of the fixing member is changed by the action of the spring. Having a magnet provided in the housing;
The fixing member is formed of a ferromagnetic material;
The butterfly valve according to claim 1, wherein the height of the fixing member is changed by the action of the magnet. Provided in the valve body, and having a hole penetrating from the surface on the high pressure side of the fluid to the position of the fixing member;
The butterfly valve according to claim 1, wherein the height of the fixing member varies depending on the fluid flowing into the hole. The fixing member is formed of a material having a larger thermal expansion coefficient than the seal ring,
The butterfly valve according to claim 1, wherein the height of the fixing member is changed by a temperature increase of the fixing member. The butterfly valve according to any one of claims 1 to 5, wherein a normal direction of a disc of the valve body is perpendicular to an axial direction of the valve shaft. The said valve body has a control part which controls the movement of the said fixing member in the circumferential direction of the said valve body to the range which does not reach the support part which supports the said valve shaft in the said housing. The butterfly valve according to any one of claims 6. An exhaust pipe for flowing the exhaust gas of the internal combustion engine;
The exhaust apparatus which has a butterfly valve as described in any one of Claim 1 thru | or 7 attached in the middle of the said exhaust pipe.

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