ES2287847T3 - MOUNTING STRUCTURE OF A CATALYST FOR MOTORCYCLES. - Google Patents

Abstract

Mounting structure of exhaust catalyst in an exhaust system on a motorcycle - in which an exhaust pipe (25, 26, 27) extends from an engine (10) to a silencer (28) at a rear of a vehicle body and - a catalyst tube (40) is disposed between a collecting tube (27) and the silencer (28), characterized in that - the front end of the catalyst tube (40) is connected to the collecting tube (27) by a tube front connection (42) and - the rear end of the catalyst tube (40) is connected to the silencer (28) by a rear connection tube (43), - the catalyst containment tube (40) is smaller in diameter than the silencer (28), and - the catalyst containment tube (40) is arranged in an overlapped position with a rear wheel (9) in side view.

Description

Mounting structure of a catalyst for motorcycles

The present invention relates to a Mounting structure of an exhaust catalyst in a system escape on a motorcycle.

There is a type of motorcycle that has a structure such that a plurality of exhaust pipes that extend from a multi-cylinder engine are collected in one position under the engine, its rear end is connected to a silencer through a connecting tube, a main catalyst is arranged in a soundproofing chamber in the silencer, and a Preheating tube-shaped catalyst is arranged in the connecting tube (see JP-A-10-103046).

JP 08246860 describes a mounting structure of exhaust catalyst according to the preamble of claim 1. This patent does not describe the position of the catalyst tube with Regarding the motorcycle.

JP 59082517 describes a mounting structure of exhaust catalyst in an exhaust system on a motorcycle in which an exhaust pipe that extends from an engine to a silencer on a rear of a vehicle body and a catalyst tube is disposed between a collecting tube and the silencer, where the catalyst containment tube is smaller diameter than the silencer, and the catalyst containment tube is arranged in an overlapping position with a rear wheel on side view.

In the case where a catalyst is arranged in a soundproofing chamber as in the example described, since the catalyst shape and soundproofing chamber shape depend from one another, the design flexibility is low. Also, when the catalyst is arranged in an exhaust pipe section that is connected to a silencer, since an exhaust pipe passes to through a lower portion of a vehicle body, the use of a large capacity catalyst in order to improve the exhaust gas purification efficiency is difficult in view to ensure a minimum height with respect to ground.

An object of the invention is to provide a exhaust catalyst mounting structure on a motorcycle which achieves a relatively large slope angle.

In order to achieve the object described above, according to claim 1, a mounting structure of exhaust catalyst in an exhaust system on a motorcycle in which an exhaust pipe that extends from an engine to a silencer on a rear of a vehicle body and a catalyst tube is disposed between a collecting tube and the silencer, characterized in that the front end of the tube catalyst is connected to the collecting tube by a connecting tube front and rear end of the catalyst tube is connected to the silencer by a rear connection tube, the catalyst containment is smaller in diameter than the silencer, and the catalyst containment tube is arranged in a Overlapped position with a rear wheel in side view.

Therefore, the catalyst can be arranged without depending on the shape of the silencer. Muffler shape It can also be freely determined without relying on the catalyst. Therefore, the shape of the catalyst and the shape of the chamber Soundproofing can be freely determined without relying on one of other, and therefore design flexibility is increased.

According to the invention, the exhaust system including the catalyst tube can be disposed within the vehicle body having the catalyst tube, which is smaller diameter than the silencer, in an overlapping position with the rear wheel in side view, and therefore you can ensure a relatively large slope angle.

Preferably, the catalyst tube is formed in cylindrical shape, the cylindrical shaped catalyst is contained in it, and portions that connect the catalyst tube with respect to the exhaust pipes and the silencer are shaped tapered and enlarged.

Since the catalyst tube and catalyst are They can form in a simple cylindrical shape, can be simplified Manufacturing and structure. Also, since the portions that connect the catalyst tube with respect to the exhaust pipes and the silencer are shaped and enlarged, it is achieved a smooth flow of exhaust air.

Preferably, a plurality of the exhaust pipes and a preheating catalyst is arranged in an exhaust manifold unit in which the plurality of the exhaust pipes are collected in a front portion of the vehicle body

By providing the catalyst for relatively small preheating in the manifold tube unit  Exhaust, the minimum height can be sufficiently secured with with respect to vehicle ground, efficiency can be increased of the purification of the exhaust gases of the catalyst escape.

Preferably, the catalyst of preheating is arranged under a pivot portion to pivotally support a leading end of a swing arm rear that supports the rear wheel.

Since the preheating catalyst is arranged below the pivot portion that pivotally supports the front end of the rear swing arm that supports the rear wheel, the preheating catalyst can be arranged in a preferable position of the vehicle body where You can avoid interference with the rear swing arm.

Preferably, the silencer is formed in non-cylindrical shape

Therefore, you can increase the flexibility of the arrangement, such that the silencer is form in a non-cylindrical way in order to achieve the stylization of the vehicle body or increase the angle of tilting.

Figure 1 is a side view of a motorcycle to which the present invention applies request.

Figure 2 is a side view of a portion of an exhaust system.

Figure 3 is a plan view of the portion of the exhaust system.

Figure 4 is a plan view of a portion including a catalyst tube and a silencer.

Figure 5 is a partially side view cut from the same portion.

Figure 6 is a cross-sectional view. taken along a line 6-6 in the figure Four.

Figure 7 is a drawing depicting a shape of a rear end portion of the silencer.

Figure 8 is a cross-sectional view. taken along a line 8-8 in the figure 5.

With reference now to the drawings will be described an embodiment. Figure 1 is a left side view of a vehicle body of a motorcycle to which the Invention of the present application. A pair of front forks left and right 2 that support a front wheel 1 in their lower ends, are connected at the upper ends to a front tube 3 so that it can be directed by a handlebar 4.

The front tube 3 is mounted on ends front of the main frames 5. A pair of the frames  main left and right 5 extend from the tube front 3 so that they open back, and pivot plates 6 are mounted respectively at their rear ends. A pair of the left and right pivot plates 6 are formed substantially L-shaped in side view, and support both ends of a pivot shaft 7 arranged laterally In between.

A front end of a swing arm rear 8 is tiltedly supported by pivot shaft 7. A rear wheel 9 is supported on the rear end of the arm rear swingarm 8. A four-stroke engine cooled by V-shaped water 10 in the forward direction is arranged under the main frame 5. Engine 10 is supported by the main frame 5, pivot plates 6, and a down tube 11 extending obliquely down and back of the tube forward 3.

A pair of left and right brackets 12 that they protrude upwards, they are arranged integrally in the respective front end portions of the pivot plates left and right 6, and a rear shock absorber 13, which constitutes a rear wheel suspension is connected between bracket 12 and the upper front surface of the rear swing arm 8. The front ends of upper seat rails 14 are mounted on the upper portions of the respective supports 12. A pair of upper left and right seat rails 14 they extend obliquely up and back, respectively, and rear end portions of elements of reinforcing tube 15 that extend substantially horizontal are connected to their rear ends.

Handles 16 are arranged above the reinforcing tube elements 15, and a slide box 17 are supports in back extensions of handles 16. A seat double 18 is arranged at the front of the handles 16, and it is supported on the upper seat rails 14. A cover rear 19 is supported under the seat 18. The number of reference 19a designates a tail lamp, and the number of reference 19b designates a lateral capacity slide relatively large

A pair of lower seat rails left and right 20 are arranged under the rails upper seat 14, and their respective front ends are connected to the rear portion of the engine 10, and its ends rear are connected to the rear ends of the rails upper seat 14. The upper seat rails 14 and lower seat rails 20 constitute a lane of seat.

A fuel tank 21 is arranged in the front of the seat 18 and above the engine 10, and it supports on top of the main frames 5 and the plates of pivot 6. An air filter 22 is integrated into the portion front of the fuel tank 21, and feeds a cylinder front 23 and a rear cylinder 24 of the engine 10.

A front exhaust pipe 25 and a pipe rear exhaust 26 extend from respective holes in exhaust of the front cylinder 23 and the rear cylinder 24, and it collect in a position under the engine 10 forming a tube manifold 27 and is also connected to a silencer 28 in the part rear The collecting tube 27 is supported by the ends bottom of the pivot plates 6, and the silencer 28 is arranged on the side of the rear wheel 9 and is supported by a support 29 extending down the bottom rail of seat 20. A radiator 30 is supported by the downstream tube 11 at the front of the front cylinder 23 to cool by water the front cylinder 23 and the rear cylinder 24.

The front body portion of vehicle is covered by a front fairing 31, and a portion front end 31a covers a headlight 32 at the front of the front tube 3. Front turn signals 33 are arranged in lateral surfaces of the front end portion 31a. A windshield 34 is disposed above the end portion front 31a, and is supported by the front tube 3 by a windshield mount 35. Reference number 36 designates a instrument.

Figure 2 and Figure 3 are a view in plant and a side view of a portion of an exhaust system from the manifold 27 to the silencer 28. In these drawings, enter the collecting tube 27 and the silencer 28 have a tube catalyst 40. The catalyst tube 40 has a cylindrical shape, and in he is contained a publicly known exhaust catalyst 41 which also has a cylindrical shape. The exhaust catalyst 41 it has a relatively large capacity that may be sufficient to purify the exhaust air.

The outer diameter of the catalyst tube 40 is of a size between the collecting tube 27 and the silencer 28, and between a front end of the catalyst tube 40 and a rear end of the collecting tube 27, and between a rear end of the tube catalyst 40 and a front end of silencer 28 are connected by tapered connecting pipes front and rear 42, 43. In this embodiment, a diameter when the silencer 28 has a non-cylindrical shape indicates a diameter of a delimiting circle which can include the entire silencer 28 or a diameter of a similar circle.

The respective tapered connecting pipes 42, 43 open towards the rear (down the air of escape). The front portion of the collecting tube 27 is forked, forming bifurcations 44a, 44b that are connected to the tube of front exhaust 25 and rear exhaust pipe 26. The portion rear of the collecting tube 27 is provided with a heat pipe 45, and therein a preheating catalyst 46 is provided. heat pipe 45 is placed under pivot shaft 7 (see the figure 2).

The preheating catalyst 46 is heated by the exhaust air collected in heat pipe 45, and increase the exhaust temperature on the side facing down to preheat and sufficiently activate a catalytic action in the exhaust catalyst 41. Therefore, compared to the exhaust catalyst 41, preheating catalyst 46 it should only have a relatively small capacity, and it has a simple cylindrical shape. Reference numbers 47 to 49 in the Drawing designate brackets.

Figure 4 is an enlarged plan view of a portion including catalyst tube 40 and muffler 28, and Figure 5 is a side view of them representing the interior of silencer 28 as a soundproofer. How I know depicted in figure 4, the silencer 28 is arranged substantially in parallel with the center of the body of vehicle, and catalyst tube 40, tapered connecting tube front 42, and the tapered rear connection tube 43 are curved into the vehicle body so that its front portions are directed towards the center of the body of vehicle. The support 49 is arranged on a front surface upper silencer 28 so that it is moved towards the vehicle body center.

As depicted in Figure 5, the interior of silencer 28 is divided into three soundproofing chambers 50-52 in the direction from front to back, and as depicted in the drawing with arrows, exhaust air flows from the first soundproofing chamber 50 through a first tube of connection 53 and return to the third soundproof chamber 52, then flows through a second connection tube 54 and enters the second soundproofing chamber 51, and is subsequently discharged from the second soundproofing chamber 51 by a third tube of 55 connection to the atmosphere. A rear end portion of the third connecting tube 55 passes through an end plug 56 And it opens to the atmosphere.

The silencer 28 has a tube structure double wall, and an inner tube 57 has a structure of air ventilation such as punching metal or the like, and communicates with a clearance 59 defined between the inner tube 57 and a tube outside 58. The clearance 59 is filled with soundproofing material such Like glass wool

Figure 6 is a cross-sectional view. taken along a line 6-6 in figure 4. The rear end portion of the catalyst tube 40 has a double wall tube structure including connecting tube rear tapered 43 and catalyst tube 40 with the inner side of the rear tapered connection pipe 43 protruding backwards. The rear end portion of the exhaust catalyst 41 contained in the catalyst tube 40 is partially inserted in the first 50 soundproofing chamber.

Figure 7 is a drawing that represents the shape of the rear end portion of the silencer 28 as seen in the direction indicated by an arrow 7 in figure 5, and figure 8 it is a cross-sectional view taken along a line 8-8 in Figure 5. As depicted in these drawings, the silencer 28 has a non-cylindrical shape, in this embodiment, has a substantially inverted triangular shape, and an inner surface 60 of three surfaces constituting its lateral surface assumes a substantially flat surface that extends substantially in parallel with the vertical direction and it is in front of the lateral surface of the rear wheel 9.

An upper surface 61 also assumes a substantially horizontal flat surface. An outer surface  62 is an inclined surface, and its rear end is inclined towards the center of the vehicle body. Therefore, the cross-sectional shape of the silencer 28 is such that the upper portion is the enlarged portion whose width increases towards outside the vehicle body and the lower end has the smaller width

As depicted in Figure 8, the third soundproofing chamber 52 (the same in other soundproofing chambers) It has a substantially inverted triangular shape, and only the first connecting tube 53 is disposed in its lower portion, which is the narrowest portion, and the second connecting tube 54 and the third connecting tube 55 are juxtaposed in the portion wider wider.

As depicted in Figure 7, since the rear end portion of the third communication tube 55 is opens the third end tube to the center of the end plug 56 communication 55 is inclined obliquely down towards the rear part as shown in figure 5, so that head towards the center of the vehicle body.

The operation of the invention. As depicted in Figures 1 to 3, since the catalyst tube 40 is disposed in the connection portion between the silencer 28 and the manifold 27, exhaust air that has passed through the front exhaust pipe 25 and the rear pipe of Exhaust 26 passes under engine 10, is collected in the tube manifold 27, is sufficiently purified by the catalyst of relatively large capacity exhaust 41 in the catalyst tube 40, enters silencer 28, and is discharged into the atmosphere.

So, although the soundproof chamber in the silencer 28 assume a substantially inverted triangular shape,  since the catalyst tube 40 is located outside the silencer 28, can be formed in a simple cylindrical shape without relying on the Soundproof chamber shape. In contrast, the form of silencer 28 does not depend on the shape of the exhaust catalyst 41. Therefore, catalyst tube 40 and silencer 28 are designed in any form, respectively. The catalyst of Preheating 46 in the collecting tube 27 is also the same. By Therefore, design flexibility is increased.

In addition, since the catalyst tube 40 is connected to the collecting tube 27 by the tapered connecting tube front 42, and the silencer 28 via the connecting tube rear tapered 43, the collection tube 27, the catalyst tube 40, and the silencer 28 that have different diameters, can be connected so that they gradually increase in diameter towards below the exhaust air, and a smooth flow of the air from escape.

Since the catalyst tube 40 is in diameter smaller than silencer 28, it can be arranged near the center of the vehicle body without interference with the wheel rear 9 arranging it so that it overlaps the wheel rear 9 in side view. In this way, you can ensure a relatively large slope angle reducing the amount that the exhaust system protrudes including the containment section of catalyst by arranging it inside the body of vehicle.

Since the silencer 28 is formed substantially inverted triangular shape, and the surface interior 60 assumes the flat surface that extends substantially in parallel with the vertical surface, the silencer 28 can be arranged in a position closer to the lateral surface of the rear wheel 9. Also, since the outer lateral surface 62 assumes open inclined surface up and out, the tilt angle can also be increase. Forming the silencer 28 in a non-cylindrical shape as described above, flexibility can be increased of the arrangement so that simultaneously it can be Stylize the vehicle body and ensure the angle of tilt.

In addition, since the heat pipe 45 is disposed in the rear portion of the collecting tube 27, and the preheating catalyst 46 is contained therein, the air of Exhaust can be preheated in the heat pipe section 45, by what can be activated catalytic action by the catalyst of escape 41, and the debugging efficiency of Exhaust gases

In addition, since the heat pipe 45 is placed substantially immediately below pivot shaft 7, it can be arranged near the center of tilting movement of the rear swing arm 8, so the catalyst of preheating 46 can be placed in a preferable position in the vehicle body where arm interference is avoided rear swingarm 8.

In addition, since the catalyst of relatively small preheating 46 is enough even when the heat pipe 45 is disposed in the rear portion of the collecting tube 27 at low height with respect to ground, a provision with sufficient ground height.

The non-cylindrical shape of the silencer 28 is not limited to substantially triangular cross section, but It can be in various forms such as an oval shape. The forms of the exhaust catalyst 41 and the preheating catalyst 46 are not limited to the circular form, and may be a non-circular form. circular. The type of the engine is not limited, and the structure of arrangement of the exhaust catalyst in the present application is you can apply to an exhaust system that has a single pipe Single cylinder exhaust.

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The invention makes an arrangement of a exhaust catalyst in which the respective forms of the exhaust catalyst and a silencer are determined in order to avoid the interference of one with respect to the other.

In the invention, a front exhaust pipe 25 and a rear exhaust pipe 26 extending from a cylinder front 23 and a rear cylinder 24 of a V-shaped engine 10 in the direction from front to back, they are collected in a collecting tube 27 under engine 10, and its rear end portion is connected to a cylindrical catalyst tube 40 arranged in a Overlapped position with a rear wheel 9 in side view. A cylindrical exhaust catalyst 41 is contained in the tube catalyst 40. Catalyst tube 40 is connected to the tube small diameter manifold 27 through a tapered connection tube front 42, and is connected to a silencer 28 which has a substantially inverted triangular cross section with a larger diameter through a tapered rear connection tube 43.

Claims (5)

1. Catalyst mounting structure of exhaust in an exhaust system on a motorcycle

-

 in the that an exhaust pipe (25, 26, 27) extends from an engine (10) to a silencer (28) in a rear part of a body of vehicle and

-

 a catalyst tube (40) is disposed between a collecting tube (27) and the silencer (28),

characterized because

-

 he front end of the catalyst tube (40) is connected to the tube manifold (27) by a front connecting tube (42) and

-

 he rear end of the catalyst tube (40) is connected to the silencer (28) by a rear connection tube (43),

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 he catalyst containment tube (40) is smaller in diameter than the silencer (28), and

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 he catalyst containment tube (40) is arranged in a overlapping position with a rear wheel (9) in view side.

2. The exhaust catalyst mounting structure according to claim 1, characterized in that the catalyst tube is formed in a cylindrical shape, the cylindrical catalyst is contained therein, and portions (42, 43) connecting the catalyst tube (40 ) with respect to the exhaust pipes (25, 26, 27) and the silencer (41) are tapered and enlarged. 3. The exhaust catalyst mounting structure according to claim 1, characterized in that a plurality of the exhaust pipes (25, 26) and a preheating catalyst (46) is provided in a collective exhaust pipe unit (27) in which the plurality of the exhaust pipes (25, 26) is collected in a front portion of the vehicle body. 4. The exhaust catalyst mounting structure according to claim 3, characterized in that the preheating catalyst (46) is arranged under a pivot portion (7) to pivotally support a leading end of a rear swing arm (8) which Supports the rear wheel. 5. The exhaust catalyst mounting structure according to claim 1, characterized in that the silencer (28) is formed in a non-cylindrical shape.