EXHAUST SYSTEM OF AN ENGINE

Abstract

An engine exhaust device comprising an exhaust pipe (4) to be attached to a vehicle engine (2), a silencer (5) connected to a downstream side of the exhaust pipe (4), wherein the exhaust pipe (4) is connected to the silencer (5) from a front of the silencer (5) in a first direction to a rear in a first direction; and a catalyst unit (6) for cleaning exhaust gas discharged from the vehicle engine (2), wherein: the silencer (5) comprises: a first partition wall (51) dividing an internal space of the silencer (5) into at least two sub-spaces arranged in the first direction of the silencer (5), and a second partition wall (52) dividing a first of the at least two sub-spaces into two spaces arranged in a second direction of the silencer (5), the second direction intersecting the first direction.a second of the at least two sub-chambers has a larger capacity than either of the two chambers defined by the second partition wall (52), wherein the catalyst unit (6) is connected to a downstream side of the exhaust pipe (4) and the downstream side of the exhaust pipe (4) corresponds to a rear side of the exhaust pipe (4) in the first direction, wherein the catalyst unit (6) is arranged to extend parallel to the second partition wall (52), and wherein the second of the at least two sub-chambers is located in a rear part of the silencer (5) with respect to the first direction and relative to the first partition wall (51), and a downstream end of the catalyst unit (6) is open in the second of the at least two sub-chambers.

Description

AREA OF INVENTION

[0001] The present invention relates to an exhaust system for an engine. BACKGROUND OF THE INVENTION

[0002] Among engine exhaust devices used in vehicles, some are equipped with a silencer (see, for example, JP-A-2016-160915). In the exhaust device disclosed in JP-A-2016-160915, an exhaust pipe extends downward from the front surface of a cylinder head, and a silencer is connected to a downstream side of the exhaust pipe. The silencer is box-shaped with a predetermined capacity, and its internal space is divided by multiple partition walls (separators). Each of these partitions represents an expansion chamber into which the exhaust gas expands. SUMMARY OF THE INVENTION

[0003] In the engine exhaust device disclosed in JP-A-2016-160915, the expansion chambers are formed by multiple partition walls such that they are arranged in a front-to-back direction. In this case, the front-to-back lengths of the respective expansion chambers are small, meaning the intervals between the partition walls are small, which means that the degrees of freedom of the expansion chamber layout are low. This can lead to a problem in that exhaust gases do not expand sufficiently in the expansion chambers, and therefore the muffler effect is weak.

[0004] The present invention was made with regard to the above problem, and an object of the invention is therefore to provide an engine exhaust device capable of improving the silencer effect while increasing the degree of freedom of the layout of the expansion chambers and of the design of the components in a silencer.

[0005] An engine exhaust device according to one aspect of the invention comprises an exhaust pipe attached to a vehicle engine and a silencer connected to a downstream side of the exhaust pipe, wherein the silencer comprises a first partition wall dividing an internal space of the silencer into at least two spaces in a first direction, and a second partition wall dividing one of the at least two spaces into two spaces in a second direction intersecting the first direction, another of the at least two spaces having a larger capacity than each of the two spaces defined by the second partition wall, and a downstream end of the exhaust pipe opening into one of the at least two spaces.

[0006] The invention makes it possible to improve the silencer effect while increasing the degree of freedom of the layout of the expansion chambers and the design of the components in a silencer. List of characters Fig. Figure 1 is a left side view showing a configuration of a motorcycle according to an embodiment of the present invention. Fig. Figure 2 is a left side view showing the arrangement of a motor and components around it used in the embodiment. Fig. Figure 3 is a perspective of a silencer according to the embodiment. Fig. Figure 4 is a perspective view of a silencer according to a first modification. Fig. Figure 5 is a perspective view of a silencer according to a second modification. Reference symbol list 1: Motorcycle 2: Engine 4: Exhaust pipe 5, 7, 8: Silencer 50, 70, 80: Deflection plate 51, 71, 81: first deflection plate (first dividing wall) 51a, 71a, 81a, 82a: Connecting pipe (connecting section) 52, 72, 82: second deflection plate (second dividing wall) 52a, 72a: Connecting hole 55, 75, 85: Tailpipe 6: Catalyst unit 74, 84: Deflection tube S1: Expansion chamber (another room) S2, S3: Expansion chamber (one room) DETAILED DESCRIPTION OF THE INVENTION

[0007] One embodiment of the present invention is described in detail below with reference to the accompanying drawings. Although the following description focuses on a case in which the engine exhaust device according to the invention is used in a sports motorcycle, it can also be applied to other things. For example, the engine exhaust device according to the invention can be applied to other types of motorcycles, buggy-type motor tricycles, automobiles, etc. The forward, reverse, left, and right directions with respect to the vehicle are indicated by the arrows FR, RE, L, and R, respectively. In each of the drawings, some components have been omitted for the sake of clarity.

[0008] First, the configuration of a motorcycle is determined. 1 according to the embodiment with reference to Fig. 1 and Fig. 2 shown. Fig. Figure 1 is a left side view showing the motorcycle's configuration. 1 as described in the embodiment. Fig. Figure 2 is a left side view showing the arrangement of an engine. 2 and shows components around it that are used in the embodiment.

[0009] As in the Fig. 1 and Fig. As shown in section 2, the motorcycle 1 is configured in such a way that the engine 2 suspended from a vehicle body frame 10, to which various components such as a power unit and electrical components are attached. For example, the engine 2 a water-cooled parallel twin-cylinder engine. The engine 2The engine is configured such that an assembly consisting of a cylinder block 21, a cylinder head 22, and a cylinder head cover 23 is attached to an upper section of a crankcase 20, which, among other things, accommodates a crankshaft (not shown) extending in a left-right direction. An oil pan 24 is located below the crankcase 20.

[0010] In this embodiment, the crankcase 20, the cylinder block 21, the cylinder head 22, the cylinder head cover 23, and the oil pan 24 are collectively referred to as the engine housing. How Fig. Figure 2 shows the crankcase 20, which is part of the engine housing, configured to be divisible in the top-bottom direction, comprising an upper housing 20a and a lower housing 20b. By combining the upper housing 20a and the lower housing 20b to form the crankcase 20, a space is created for accommodating various shafts within the crankcase 20. In particular, the external shape of a lower rear section of the engine housing (oil pan 24 and lower housing 20b) has an inclined side profile that slopes upwards while facing rearwards.

[0011] An oil filter 26, for filtering oil in the engine 2 The used oil is attached to a front section of the lower housing 20b. An ignition magneto cover 28, which covers an ignition magneto (not shown), is attached to a left section of the crankcase 20 like an engine cover.

[0012] The vehicle body frame 10 is a diamond-shaped frame formed by, for example, welded metal tubes, and configured so that the vehicle body as a whole has the necessary rigidity when the engine 2 suspended from it, as described above. The vehicle body frame 10 extends backwards downwards from a head tube 10a. The vehicle body frame 10 has, as its front half, a mounting section 10b, which supports a front section (cylinder head 22) of the engine. 2 carries. Furthermore, the vehicle body frame 10 has, as its rear section, a joint section 10c which has a swing shaft for a swing arm 18.

[0013] The vehicle body frame 10 has, approximately in the middle in the front-to-rear direction, a seat rail 10d which extends rearward. Above the joint section 10c, the vehicle body frame 10 has a rear brace 10e which extends upward and rearward. A fuel tank 11 is arranged above the vehicle body frame 10, and a driver's seat 12 and a passenger seat 13 are provided behind the fuel tank 11 along the seat rail 10d. The cylinder head 10a is covered by a front cover 14, and a lower front section of the engine is also covered by a front cover 14. 2 is covered with a lower hood 15.

[0014] To enable steering, a pair of (left and right) fork elements 16 are supported by the head tube 10a via a steering shaft (not shown). A front wheel 17 is rotatably supported by bottom sections of the front fork elements 16 and is covered from above by a front fender 17a.

[0015] The swingarm 18 is pivotally supported by the joint section 10c and extends to the rear. A rear wheel 19 is rotatably supported by a rear end section of the swingarm 18.

[0016] An exhaust pipe 4 is at an exhaust outlet of the engine 2 attached via a turbocharger 3. The exhaust pipe 4 extends downwards from a front section of the engine 2 , is then bent backwards at a position on the front right side of the oil pan 24, and then extends backwards parallel to the surface of the right side of the oil pan 24. The silencer 5 (also referred to as a chamber or a silencer) is connected to a downstream end section of the exhaust pipe. 4 connected. In this embodiment, the turbocharger 3 can be omitted.

[0017] As described in detail later, a catalyst unit 6 (see Fig. 3), which cleans the exhaust gas of engine 2, downstream of the exhaust pipe 4 arranged. The catalyst unit 6 is in the silencer 5 The catalyst, for example a three-way catalyst, converts pollutants (carbon monoxide, hydrocarbons, nitrogen oxides, etc.) from the exhaust gas into harmless substances (carbon dioxide, water, nitrogen, etc.). Exhaust gas produced by the combustion of the engine. 2 The gas produced flows through the exhaust pipe. 4 to the catalyst unit 6 , where it is cleaned. The exhaust gas is reduced in level, resulting in less exhaust noise, by the silencer. 5 it runs through and is then carried outwards.

[0018] Furthermore, silencers installed in motorcycles as part of an engine exhaust system are classified into two types: those shaped like a long tube (e.g., a cylinder) and those shaped like a box (e.g., a cuboid). Among these silencers, some have an internal chamber divided by multiple partitions. These chambers are connected to each other by connecting holes or pipes. Exhaust gases exiting the engine flow into the silencer chambers through the exhaust pipe and expand within them, reducing the level of exhaust noise.

[0019] However, the exhaust noise reduction effect depends on the capacity and shape of the silencer, with the structure of the partition walls being an important factor in the silencer's design. For example, in a silencer shaped like a tube extending from front to back, one option is to divide its internal space so that several chambers are arranged along the silencer's length (e.g., in the front-to-back direction).

[0020] On the other hand, in box-shaped silencers, if a partition wall structure similar to that described above for cylindrical silencers is used, a problem arises: the front-to-back length of each chamber is reduced, and the degree of freedom in the layout of the expansion chambers is diminished. Furthermore, reducing the intervals between the partition walls can negatively impact the layout, ease of attachment, and ease of welding of peripheral components. Additionally, a connecting hole or pipe might be shaped in such a way that it passes close to another, adjacent partition wall, resulting in exhaust gas directly impacting and vibrating the other partition wall.

[0021] In light of the above, the present inventor devised an engine exhaust device that has a box-shaped silencer whose sound attenuation effect can be improved, while ensuring the necessary capacity for the expansion chambers. More precisely, the embodiment uses a structure in which the internal space of the silencer 5 , which is connected to a downstream side of the exhaust pipe 4 is connected by a T-shaped deflection plate 50 into three rooms (expansion chambers) S1 - S3 (described later)) is subdivided (see Fig. 3) How Fig. 3 shows the deflection plate 50 through a first deflection plate 51 (first partition wall), which forms the internal space of the silencer 5 divided into two spaces in a first direction (front-back direction), and a second deflection plate 52(second partition wall), which forms one of the two sub-spaces formed by the first deflection plate 51 are formed, divided into two spaces in a second direction (left-right direction) that intersects the first direction.

[0022] Since the internal space of the silencer 5 in the front-back direction and the left-right direction in three expansion chambers S1 - S3 Because it is subdivided, this structure can prevent each expansion chamber from expanding longitudinally (front-to-back), unlike in the case where the internal space of a silencer is divided. 5 , which is only divided in one direction into three expansion chambers (front-to-back direction), is shortened. Each of the expansion chambers S1 - S3 It can be given a shape that closely resembles a cube.

[0023] The sound attenuation effect of a silencer depends on the surface area of ​​the three-dimensional shape of the expansion chamber; for example, the sound attenuation effect is greater when the relative surface area (e.g., the ratio of the surface area of ​​the three-dimensional shape to its volume (capacity)) is smaller. Where three expansion chambers are arranged in one direction (longitudinal direction), each expansion chamber assumes a cuboid shape with a rectangular cross-section, the sides of which extending in one direction are significantly shorter than the sides extending in the other direction. In contrast, in the embodiment, since the internal space of the silencer 5 into the three expansion chambers S1 - S3 through the T-shaped deflection plate 50The expansion chambers S1-S3 are divided into two parts, each with a shape closer to a cube than to a cuboid, which has a rectangular cross-section, the sides of which extend in one direction being significantly shorter than the other sides extending in the other direction.

[0024] In general, the surface area of ​​a three-dimensional shape decreases as it approaches a sphere, while keeping its volume constant; a cube has a smaller surface area than a cuboid, which has rectangular faces. By designing each expansion chamber to closely resemble a cube, its surface area is reduced, and it becomes possible to improve the sound attenuation effect, while increasing the degree of freedom in the layout of the expansion chambers and the design of components within the silencer. 5 is increased.

[0025] Although the details will be described later, the other room (expansion chamber) S1 ), which passes through the first deflection plate 51 is defined as being larger in its capacity than any of the rooms (expansion chambers). S2 and S3 ), which is through the second deflection plate 52 are defined, and the downstream end of the exhaust pipe 4 is in the expansion chamber S1 opened. This allows exhaust gas from the engine to escape. 2 The match will initially take place in the expansion chamber. S1 , which has the greatest capacity to release (expand). As a result, a large amount of the exhaust gas's energy can be released in the expansion chamber. S1 The dimensions can be reduced to further increase the sound-dampening effect. Additionally, sufficient distances can be maintained between the open end of the exhaust pipe. 4 and the partition walls (deflection plate) 50) are secured, which can suppress vibration of the partition walls caused by exhaust gas.

[0026] The silencer will be used next. 5 according to the embodiment in detail with reference to the Fig. 2 and Fig. 3 described. Fig. Figure 3 is a perspective view of the silencer. 5 according to the embodiment. In Fig. Figure 3 shows the direction of the exhaust flow, indicated by dashed arrows.

[0027] Fig. 2, which is a side view, shows how the silencer 5 located at the rear of the oil pan 24 and under the swing arm 18 and connected to a downstream end section of the exhaust pipe 4 is connected. As in Fig. As shown in section 3, this is the exhaust pipe. 4 arranged so that it extends from the central plane to the right, in the left-right direction, of the silencer. 5 It is offset and shaped like a box.

[0028] The silencer 5 The exhaust pipe is formed by welding together an upper half-section 5a, which is open at the bottom, a lower half-section 5b, which is open at the top, and a front wall section 5c, which covers the front end sections of the upper half-section 5a and the lower half-section 5b, in a box shape. 4 is attached to the silencer 5 in such a way that it penetrates the front wall section 5c.

[0029] A side view shows a front half-section of the silencer. 5 It is shaped approximately like a triangle, the height of which increases with the backward position, and the rear half of which is shaped like a rectangle. Similar to the front half of the silencer. 5 The height of an upstream section is slightly greater than the outer diameter of the exhaust pipe. 4, and the outer surface (top surface), which coincides with the hypotenuse of the approximate triangular shape in a side view, is inclined so that it extends upwards and backwards. The bottom surface of the lower half-section 5b of the silencer 5 extends horizontally backwards. A rear half-section of the silencer. 5 is continuous with its anterior half-section and extends horizontally backwards.

[0030] The internal space of the silencer 5 is through the deflection plate 50 divided into several expansion chambers. The deflection plate 50 has the first deflection plate 51 , which the internal space of the silencer 5 divided into a front half-section and a rear half-section, and the second deflection plate 52 , which divides the front half-section into two sections in the left-right direction. The first deflection plate51 is a flat, vertical dividing wall located near the boundary between the front half-section and the rear half-section of the silencer. 5 located, that is, located in a position that is somewhat towards the rear of the center of the silencer 5 in the front-to-back direction. The second deflection plate 52 is a vertical partition wall extending forward from the front surface of the first deflection plate 51 It extends, and in a side view it is roughly triangular in shape. The second deflection plate 52 is on the left side of the central plane, in the left-right direction, of the silencer 5 displaced.

[0031] As described above, the internal space of the silencer 5 into the three expansion chambers S1 , S2 and S3 through the deflection plate 50 subdivided. The expansion chamber S1is the internal space of the rear half-section of the silencer 5 , the expansion chamber S2 is the internal space of a right-hand section of the front half-section of the silencer 5 , and the expansion chamber S3 is the internal space of a left-handed section of the front half-section of the silencer. 5 The expansion chambers S1 , S2 and S3 are structured in such a way that their capacity decreases in this order.

[0032] A connecting pipe 51a , which is a connecting section to the expansion chambers S1 and S2 to allow them to communicate with each other is at the first deflection plate. 51 attached in a position slightly to the left of the center of the first deflection plate 51 is offset upwards. The connecting pipe 51aIt is shaped like a cylinder and extends in the front-to-back direction to the first deflection plate. 51 to penetrate in the direction of thickness. A connecting hole 52a , which is a connecting section to the expansion chambers S2 and S3 to allow them to communicate with each other, penetrates the second deflection plate. 52 in their thickness direction at a position close to their front upper corner. The connecting hole 52a is formed in such a position that it is visible in a side view with the exhaust pipe 4 overlaps.

[0033] As described above, the exhaust pipe penetrates 4 a right half-section of the front wall section 5c, and an upstream end section of the catalyst unit 6 is attached to a rear end section of the exhaust pipe 4attached by means of a conical pipe 53. The first conical pipe 53 is connected to a downstream end section of the exhaust pipe 4 with the expansion chamber. S2 connected and its diameter increases in the downstream (backward) position. The catalyst unit 6 is connected to a rear end section of the first conical tube 53.

[0034] The catalyst unit 6 It is shaped like a cylinder, extends in a front-to-back direction, and is larger in diameter than the exhaust pipe. 4 The catalyst unit 6 It is designed in such a way that a cylindrical honeycomb section, which performs the oxidation or reduction of specific exhaust gas components, is covered by an outer cylindrical section. The catalyst unit 6 extends backwards and then penetrates the first deflection plate 51 The catalyst unit6 is thus supported by the first deflection plate 51. The downstream end of the catalyst unit 6 is in the expansion chamber S1 open.

[0035] A tailpipe 55 , which carries the exhaust gas to the outside, which passes through the expansion chambers S1 - S3 The flow is in the silencer. 5 provided. The tailpipe 55 It is formed by bending a cylindrical tube so that it assumes an L-shape in a top view. In particular, the end pipe penetrates 55 the second deflection plate 52 from the side of the expansion chamber S3 , then goes into the expansion chamber on the right S2 , is then in the chamber S2 bent back, and then penetrates the first deflection plate 51 The tailpipe 55 extends into the expansion chamber S1backwards, then penetrates, at a rear right position, sections located on the two respective sides of the horizontal dividing plane, which comprise the expansion chamber S1 form, from the upper half-section 5a and the lower half-section 5b, and is finally from the silencer 5 open to the outside.

[0036] The upstream end of the tailpipe 55 is located behind the connecting hole 52a The tailpipe 55 penetrates the first deflection plate 51 at a position on the right side of the connecting pipe 51a The connecting pipe 51a is in such a position that it is in contact with the tailpipe 55 overlapping in a rear view.

[0037] Exhaust gas produced by the combustion of the engine 2 The exhaust gas produced and discharged from an exhaust port is fed into the silencer. 5 via the exhaust pipe 4introduced. In the silencer 5 The exhaust gas passes through the catalytic converter unit. 6 cleaned and then from the rear end of the tailpipe 55 about the expansion chambers S1 - S3 The exhaust gas is carried outwards. More precisely, it disperses in the expansion chamber. S1 , after the catalyst unit 6 This happened. Consequently, the exhaust gas is carried out via the connecting pipe. 51a from the expansion chamber S1 into the expansion chamber S2 inserted and then through the connecting hole 52a into the expansion chamber S3 introduced. Finally, the exhaust gas exits the expansion chamber. S3 into the tailpipe 55 and is from the tailpipe 55 expelled outwards.

[0038] The noise level of the exhaust gas is gradually reduced as it passes through the expansion chambers. S1 - S3flows. In particular, the capacities of the expansion chambers S1-S3 decrease stepwise in this sequence, that is, in the sequence of the passage of the exhaust gas, whereby the exhaust gas sound attenuation effect is adjusted so that it is varied stepwise.

[0039] In this embodiment, the internal space of the silencer 5 in three expansion chambers S1 - S3 subdivided, and the connecting pipe 51a and the connecting hole 52a (Connecting sections) are each located in the first deflection plate 51 and the second deflection plate 52 formed. Thus, exhaust gas does not directly hit the deflector plate. 50 (first deflection plate 51 or second deflection plate 52 ), when it flows from one expansion chamber to another through each connecting section. This means that none of the connecting sections of the deflector plate 50opposite. A vibration of the deflection plate. 50 can therefore be suppressed.

[0040] Since the connecting pipe 51a with the tailpipe 55 overlapping in a rear view (e.g. from the downstream side of the connecting pipe) 51a (Considering the exhaust gas), it hits the outer surface of the tailpipe. 55 , when it enters the expansion chamber S2 from the expansion chamber S1 through the connecting pipe 51a flows. Since the outer surface of the tailpipe 55 Because the tailpipe 55 has a curved surface, it is not susceptible to being set into vibration by the exhaust gas. This prevents the exhaust gas from affecting the curved outer surface of the tailpipe. 55 This is a positive measure to improve the soundproofing effect.

[0041] As described above, the catalyst unit 6 with a downstream side of the exhaust pipe 4connected and extends parallel to the second deflection plate 52 in the silencer 5 This structure makes it possible to assign the respective expansion chambers S1 - S3 to provide sufficient capacity while the catalyst unit 6 is located in the silencer 5. Furthermore, the catalytic converter unit is also located there. 6 to the right side in the silencer 5 offset, which makes it possible to adjust the expansion chambers S1 and S2 to use the catalyst unit 6 to install, which are among the components of the silencer 5 is relatively large, as well as the degree of freedom of the pipe layout for forming an exhaust gas flow passage in the silencer 5 increased.

[0042] The catalyst unit 6It is attached to the first deflector plate 51 in such a way that it penetrates and is supported by it. This avoids a separate structure that supports the catalyst unit. 6 carries, and thus makes it possible to reduce the weight of the silencer. 5 to avoid.

[0043] Since the expansion chamber S1 as a rear chamber of the silencer 5 Once formed, a posterior half-section can 5 the silencer 5 , where a relatively ample space can easily be secured, can be used to create the expansion chamber S1 to form the one with the largest capacity. Furthermore, the downstream end of the catalyst unit. 6 into the expansion chamber S1 opened, thereby allowing exhaust gas, which is currently entering the catalytic converter unit, to pass through. 6 what happened in the expansion chamber S1 It can be dispersed. This makes it possible to effectively dampen the energy of the exhaust gas.

[0044] The following are engine exhaust devices according to modifications with reference to the Fig. 4 and Fig. 5 described. Fig. 4 and Fig. The 5 images are each perspective views of a silencer. 7 according to a first modification and a silencer 8 according to a second modification. The modifications differ from the original design in the layout of the expansion chambers and the arrangement of the pipes, etc., within the silencer. Thus, the silencers are 7 and 8 in their external shape identical to the silencer 5 , who in Fig. Figure 3 shows that components of each modification that have the same names as in one of the embodiments may have the same reference symbols as the latter. Descriptions of components of each modification that have the same names as in the embodiment are omitted where appropriate.

[0045] In the first modification, which was in Fig. Figure 4 shows the internal space of the silencer. 7 through a deflection plate 70 divided into several expansion chambers. More precisely, the deflection plate 70 formed by a first deflection plate 71 , which divides the internal space into a front half-section and a rear half-section, and a second deflection plate 72 , which is the rear half of the silencer 7 divided into two sections in the left-right direction. As such, the deflection plate 70 a T-shape in a top view. The first deflection plate 71 is a flat, vertical dividing wall located near the boundary between the front half-section and the rear half-section of the silencer. 7 located, that is, approximately in the middle of the silencer 7in the front-to-back direction. The second deflection plate 72 is a vertical partition wall that has the same vertical length as the first deflection plate 71 has and moves backwards approximately from the middle of the first deflection plate 71 extends in the left-right direction. The second deflection plate 72 is slightly to the right in the silencer 7 displaced.

[0046] As described above, the internal space of the silencer 7 in three expansion chambers S1 , S2 and S3 through the deflection plate 70 subdivided. The expansion chamber S1 is the internal space of the front half-section of the silencer 7 , the expansion chamber S2 is the internal space of a left-hand section of the rear half-section of the silencer 7, and the expansion chamber S3 is the internal space of the right-hand section of the rear half-section of the silencer. 7 The expansion chambers S1 , S2 and S3 are structured in such a way that their capacity decreases in this order.

[0047] A connecting pipe 71a is attached to the first deflection plate 71 at a lower left position in such a way that it is directed to the expansion chambers S1 and S2 It is permitted to be in contact with each other. The connecting pipe 71a It is shaped like a cylinder and extends in the front-to-back direction, so that it is the first deflection plate. 71 penetrates in the direction of its thickness. A connecting hole 72a penetrates the second deflection plate 72 in their thickness direction at a position close to their upper front corner, thereby allowing the expansion chambers S2 and S3, to be in contact with each other.

[0048] As described above, the exhaust pipe penetrates 4 a right half-section of the front wall section 5c, and an upstream end section of the catalyst unit 6 is connected via a first conical pipe 73 to a rear end section of the exhaust pipe 4 connected. A deflection pipe 54, which creates an exhaust gas passage in the silencer. 7 is, is with a downstream end section of the catalyst unit 6 tied together.

[0049] The first conical pipe 73 is connected to the downstream end section of the exhaust pipe. 4 connected and the catalyst unit 6 is connected to a rear end section of the first conical tube 73. The catalyst unit 6 It is shaped like a cylinder, extends in a front-to-back direction, and is larger in diameter than the exhaust pipe. 4The catalyst unit 6 is the upstream (front) expansion chamber S1 the silencer 7 arranged. This structure makes it possible to direct the exhaust gas, which has a relatively high temperature, into the catalyst unit. 6 to introduce, because the catalyst unit 6 can be arranged in such a way as to achieve the most upstream position possible. As a result, the temperature of the catalyst is increased to accelerate the cleaning of the exhaust gas, that is, the cleaning performance is improved.

[0050] The deflection plate 74 includes a second conical tube 74a, which connects to the downstream end section of the catalyst unit 6is connected to a U-shaped tube 74b, which is connected to a downstream end section of the second conical tube 74a. The diameter of the second conical tube 74a decreases with downstream position (backward). An upstream end section of the second conical tube 74a is connected to the first deflector plate. 71 so that it penetrates them. That is, the downstream end section of the catalyst unit. 6 is through the first deflection plate 71 carried. A downstream end section of the second conical tube 74a is located in the expansion chamber S3.

[0051] The U-shaped tube 74b extends backwards into the expansion chamber. S3 , while maintaining the same diameter as in the downstream end section of the second conical tube 74a, and is then bent so that it forms the second deflecting plate 72from right to left. The U-shaped tube 74b is inclined so that it extends upwards to the right in a front view, and it is bent so that it assumes a U-shape when viewed from an upper right position. The bent section of the U-shaped tube 74b is located approximately at the position where the U-shaped tube 74b passes through the second deflecting plate. 72 crosses.

[0052] After passing through the second deflection plate 52 The U-shaped tube 54b extends forward into the expansion chamber. S2 and then penetrates the first deflection plate 71 at a position near its upper left corner, in order to enter the expansion chamber S1 to reach it. A downstream end section of the U-shaped tube 74b is angled downwards in the expansion chamber. S1 bent so that it extends along the outer surface of the upper half-section 5a (see Fig. 2), and is in the expansion chamber S1 open.

[0053] A tailpipe 75 , which extends to the rear, is attached to sections located on the respective two sides of the horizontal dividing plane and the expansion chamber S3 form, from the upper half-section 5a and the lower half-section 5b. An end section of the tailpipe 75 penetrates the wall of the silencer 5 in a rear right position and faces the expansion chamber S3 before.

[0054] In the second modification, which in Fig. Figure 5 shows the internal space of the silencer. 8 into several expansion chambers through a deflection plate 80 subdivided. More precisely, the deflection plate is 80 from a first deflection plate 81, which divides the internal space into a front half-section and a rear half-section, and a second deflecting plate 82 , which are the rear half-section of the silencer 8 Divided into two sections in the top-bottom direction, they are assembled. As such, the deflection plate 80 In a side view, it forms a T-shape. The first deflection plate 81 is a flat, vertical dividing wall located near the boundary between the front half-section and the rear half-section of the silencer. 8 located, that is, approximately in the middle of the silencer 8 in the front-to-back direction. The second deflection plate 82 is a horizontal partition wall that has the same length in the left-right direction as the first deflection plate 81and extends backwards from a line that is slightly above the central line (which is located in the horizontal dividing plane of the upper half-section 5a and the lower half-section 5b) of the first deflecting plate 71 in the top-bottom direction.

[0055] As described above, the internal space of the silencer 8 in three expansion chambers S1 , S2 and S3 through a deflection plate 80 subdivided. The expansion chamber S1 is the internal space of the front half-section of the silencer. 8 , the expansion chamber S2 is the internal space of a lower section of the rear half-section of the silencer 8 , and the expansion chamber S3 is the internal space of an upper section of the rear half-section of the silencer 8 The expansion chambers S1 , S2 and S3are structured in such a way that their capacity decreases in this order.

[0056] A connecting pipe 81a is attached to the first deflection plate 81 at a position that is slightly to the left of center to accommodate the expansion chambers S1 and S2 to allow them to communicate with each other. The connecting pipe 81a It is shaped like a cylinder and extends in the front-to-back direction so that it forms the first deflection plate. 81 penetrates in its thickness direction. The connecting pipe 81a It has an elliptical cross-section that is long in the left-right direction. A connecting pipe 82a is at the second deflection plate 82 attached in a position close to its rear left corner, and penetrates the second deflection plate 82 in their thickness direction, to the expansion chambers S2 and S3 to allow them to be in contact with each other.

[0057] As described above, the exhaust pipe penetrates 4 a right half-section of the front wall section 5c, and an upstream end section of the catalyst unit 6 , is connected via a first conical pipe 83 to a rear end section of the exhaust pipe 4 connected. A deflection pipe 84 , which is an exhaust gas passage in the silencer 8 is connected to a downstream end section of the catalyst unit 6. The first conical tube 83 is connected to the downstream end section of the exhaust pipe. 4 connected and the catalyst unit 6 is connected to a rear end section of the first conical tube 83. The catalyst unit 6 It is shaped like a cylinder, extends in a front-to-back direction, and is larger in diameter than the tailpipe. 4 .

[0058] The deflection tube 84includes a second conical tube 84a, which is connected to the downstream end section of the catalyst unit 6 is connected, and a U-shaped tube 84b, which is connected to a downstream end section of the second conical tube 84a, approximates a U-shape in a plan view. The diameter of the second conical tube 74a decreases with downstream position (backward). An upstream end section of the second conical tube 84a is connected to the first deflector plate. 71 so that it penetrates it. That is, the downstream end section of the catalyst unit 6 is through the first deflector plate. 81 carried. A downstream end section of the second conical tube 74a is located in the expansion chamber. S2 .

[0059] The U-shaped tube 84b extends backwards into the expansion chamber. S3, while the diameter is kept the same as the downstream end section of the second conical tube 84a, and is then in a rear position in the expansion chamber S2 bent so that it extends forward and to the left. The U-shaped tube 78b then extends forward and penetrates the first deflection plate. 81 The end of the U-shaped tube 84b is inserted into the expansion chamber. S1 open.

[0060] A tailpipe 85 , which carries the exhaust gas outwards, which passes through the expansion chambers S1 - S3 The flow is at the silencer 5 attached. The tailpipe 85 It is formed by bending a cylindrical tube so that, when viewed from the rear, it approximates an L-shape. More precisely, the tailpipe extends 85 from the expansion chamber S3 down to the expansion chamber S2 , penetrates the second deflection plate 82, and then goes backwards and to the right into the expansion chamber S2 bent. The tailpipe 85 penetrates, at a rear right position, sections located on the respective two sides of the horizontal dividing plane and the expansion chamber S2 form, in front of the upper half-section 5a and the lower half-section 5b, and is finally outside the silencer 5 open.

[0061] In the modifications in the Fig. 4 and Fig. 5 is also shown that exhaust gas produced by the combustion of the engine 2 is produced and carried out of the exhaust outlet via the exhaust pipe 4 in the silencer 7 or 8 is introduced. In the silencer 7 or 8 , the exhaust gas passes through the catalytic converter unit 6 cleaned and then from the rear end of the tailpipe 75 or 85 via a deflection pipe74 or 84 and the expansion chambers S1 - S3 discharged to the outside. The internal spaces of the silencers 7 or 8 are also characterized by the T-shaped deflection plate in the first and second modifications 70 or 80 into the expansion chambers S1 - S3 subdivided. In particular, in the first and second modifications, the U-shaped deflection tube is... 74 or 84 with the downstream end section of the catalyst unit 6 connected, and the downstream end of the deflection pipe 74 or 84 is in the expansion chamber S1 opened. Thus, although the expansion chamber S1 , which has the largest capacity, on a front section of the silencer 7 or 8 is arranged, exhaust gas that the catalyst unit 6 what happened, initially in the expansion chamber S1are dispersed, thereby improving the sound dampening effect.

[0062] Although the embodiments and modifications described above are aimed at the case involving a parallel two-cylinder engine 2 Although used in this case, this invention is not limited to this specific instance. For example, the engine 2 can be of the single-cylinder type or of a type having three or more cylinders. The arrangement of the cylinders is also not limited to a parallel arrangement and can be modified accordingly.

[0063] Although in the above embodiment and its modifications the vehicle body frame 10 is a diamond-shaped frame, this invention is not limited to this case. The vehicle body frame 10 can, for example, be a twin-spar frame.

[0064] Although in the above embodiment and its modifications the internal space of the silencer 5 ,7 or 8 into two sections in the front-back direction through the first deflection plate 51 , 71 or 81 is divided and one of the internal sub-spaces is divided into two sections in the left-right direction or the top-bottom direction by the second deflection plate. 52 , 72 or 82 The invention is not limited to this case, as it is subdivided. The internal space of the silencer 5 , 7 or 8 It can be divided into more than three sections. Furthermore, the direction of the division is not limited to front-back, left-right, or top-down, and can be changed accordingly.

[0065] Although in the above embodiment and its modifications the first deflection plate 51 , 71 or 81 and the second deflection plate 52 , 72 or 82The invention is not limited to cases where the deflection plates are formed so that they are perpendicular to each other. The angle formed by the first deflection plate 51, 71 or 81 and the second deflection plate 52 , 72 or 82 The angle formed can be changed to a prescribed, suitable angle.

[0066] Although in the above embodiment and its modifications the capacities of the expansion chambers S1 - S3 The invention is not limited to cases where the volume decreases gradually from the upstream side. It is sufficient that the expansion chamber S1 , where the exhaust gas is initially dispersed, has a largest capacity, which of the expansion chambers S2 and S3 always has the larger capacity than the other.

[0067] Although in the above embodiment and its modifications the connecting tube(s) (and the connecting hole) are used as connecting sections that are connected by the deflecting plate50 , 70 or 80 The invention is not limited to the associated structures of the embodiment and its modifications. Each connecting hole can be replaced by a connecting tube, and each connecting tube can be replaced by a connecting hole.

[0068] Although in the above embodiment and its modifications a connecting section or

[0069] Connection sections in both the first deflection plate 51 , 71 or 81 as well as the second deflection plate 52 , 72 or 82 The invention is not limited to this case, as they are formed. Connecting sections can only be in one of the first deflection plates. 51 , 71 or 81 and the second deflection plate 52 , 72 or 82 be educated.

[0070] Although the embodiment and its modifications have been described above, the embodiment and its modification(s) can be combined partially or in their entirety to form another embodiment of the invention.

[0071] The invention is not limited to the above embodiment and its modifications, but may be altered, modified, or subject to the replacement of a component(s) in various ways without departing from the spirit and scope of the technical concept of the invention. Furthermore, it may become possible to apply the technical concept of the invention using a different method, as this may result in a technical improvement, or the invention may be carried out using a different derived technique. As such, the claims should cover all embodiments encompassed within the scope of the technical concept of the invention.

[0072] If the advantage described above, namely that the sound dampening effect is improved while increasing the degree of freedom of the layout of the expansion chambers and the design of components in a silencer, is ensured, the invention is useful, especially when applied to engine exhaust devices that can be used for motorcycles. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] JP 2016160915 A [0002, 0003]

Claims

[1] An engine exhaust device comprising an exhaust pipe attached to a vehicle engine and a silencer connected to a downstream side of the exhaust pipe, wherein: The silencer includes: a first partition wall which divides an internal space of the silencer into at least two spaces in a first direction, and a second dividing wall, which divides one of the at least two rooms into two rooms in a second direction that intersects the first direction, another of the at least two rooms has a larger capacity than either of the two rooms defined by the second dividing wall, and a downstream end of the exhaust pipe into the other of which at least two rooms are open. [2] The engine exhaust device according to claim 1, wherein: the first partition wall divides the internal space in a front-to-back direction, and The second dividing wall divides one of the at least two rooms in a left-right direction or an up-down direction. [3] The engine exhaust device according to claim 1 or 2, wherein: a connecting section through which two rooms are connected is formed in the first dividing wall and / or the second dividing wall, and the capacity of at least two rooms decreases so that the exhaust gas emitted by the engine flows through the at least two rooms. [4] The engine exhaust device according to claim 3, wherein: the silencer also includes an exhaust pipe which carries the exhaust gas to an outside, and the end pipe is arranged so that it overlaps with the connecting section in one direction of the connecting section. [5] The engine exhaust device according to any one of claims 1 to 4, wherein: The engine exhaust system further comprises a catalytic converter unit which cleans exhaust gas emitted from the engine, and the catalyst unit is connected to a downstream side of the exhaust pipe and is arranged so that it extends parallel to the second partition wall. [6] The engine exhaust device according to claim 5, wherein a downstream end section of the catalyst unit is attached to the first partition wall in such a way that it penetrates and is supported by the first partition wall. [7] The engine exhaust device according to claim 5 or 6, wherein the other of the at least two spaces is located in a rear part of the silencer and a downstream end section of the catalyst unit is open in the other of the at least two spaces. [8] The engine exhaust device according to any one of claims 5 to 7, wherein: the second dividing wall divides one of the at least two rooms in a left-right direction, and The catalyst unit is offset to one side in the left-right direction. [9] The engine exhaust device according to one of claims 5, 6 and 8, wherein: the engine exhaust device further comprises a deflection pipe which is connected to a downstream side of the catalyst unit, and The deflection pipe is a U-shaped pipe and one downstream end of the deflection pipe is open into the other of at least two spaces.