JP4183120B2 - Joint part used for exhaust system of automobile and motorcycle - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a joint portion used in an exhaust device for automobiles and two-wheeled automobiles.
More specifically, the present invention relates to a joint portion that enables engine performance improvement, fuel consumption reduction, exhaust gas noise reduction, noise reduction performance improvement, and durability improvement.
[0002]
[Prior art]
An exhaust gas apparatus for automobiles and two-wheeled automobiles causes exhaust gas from each cylinder of an engine to flow out into a manifold or an exhaust pipe, and combines these exhaust gas flows at a joint portion into a single exhaust pipe. It is discharged, treated with a catalyst converter and a silencer (muffler), etc., and then discharged to the outside.
Regarding the terms of exhaust gas system devices for automobiles and motorcycles, use of an exhaust system, an exhaust pipe, an exhaust silencer, and the like is recommended (described in JIS D0109). Terms obtained by reading English into Japanese (for example, exhaust pipes) are also applicable (see, for example, Non-Patent Document 1).
[0003]
[Non-Patent Document 1]
Japan Auto Parts Industries Association: “Automotive exhaust gas manual”, 2000 [0004]
As for the “exhaust pipe”, an exhaust pipe, an exhaust pipe, a pipe portion, and the like are used as synonyms. The exhaust pipe may be divided into a front exhaust pipe, a center exhaust pipe, and a rear exhaust pipe. In this specification, the term “exhaust pipe” is used.
As for the joint part, a joint, a collecting pipe, a tornado collecting pipe and the like are used as synonyms. In this specification, the term “joint part” is used. The joint part is connected to the inlet of a plurality of upstream (two, four, six, etc.) exhaust pipes and the single exhaust pipe is connected to the outlet. It is necessary to increase the area so that the cross-sectional area of the outlet is approximately the size of a single exhaust pipe so that the inflowing exhaust gas can be smoothly merged.
Therefore, a joint part (referred to as a collecting pipe in the publication) in which the shape from the inlet to the outlet is formed into a truncated cone shape with a metal plate material has been proposed (see, for example, Patent Document 1). .
[0005]
[Patent Document 1]
JP-A-57-86515 [0006]
However, in the joint part according to this proposal, the exhaust gas stream flowing in from the upstream side goes straight and flows out, for example, directly collides with the conical slope, so that the component concentration of the exhaust gas flowing out fluctuates. Yes.
In addition, an exhaust gas component concentration detection device (typically an oxygen concentration detection device) required for engine control (typically, air / fuel ratio) is arranged in the vicinity of the joint portion or the joint portion. A joint part (referred to as a pipe part in Patent Document 2) that improves the contact between the exhaust gas flow and the detection device has also been proposed (see, for example, Patent Document 2).
[0007]
[Patent Document 2]
Japanese Utility Model Publication No. 58-36810
FIG. 8 is an explanatory view of the joint portion disclosed in the publication. The joint portion 80 shown in FIG. 8 is formed of a collecting portion 81 and four introduction portions 82, and exhaust gas is indicated by arrows 83, 84, 85, 86 from four exhaust pipes connected to the engine. Into the inside of the joint part 80 in the direction of the direction, and merged at two places of reference sign A and reference sign B, and a curved portion is provided in front of the detection device arranged downstream of reference sign B, thereby The contact between the exhaust gas flow and the detection device is improved.
Therefore, in the joint portion 80 shown in FIG. 8, when the exhaust gas from each cylinder sequentially flows in the direction of the arrows 83, 84, 85, 86 in time series by the operation of the four cylinders of the engine, Exhaust interference occurs.
In order to prevent exhaust interference between the cylinders, a joint part (referred to as a collecting pipe part in Patent Document 3) shown in the explanatory view of FIG. 9 is proposed (for example, Patent Document 3). (See 3)
[0009]
[Means for Solving the Problems]
The joint part used in the exhaust system of the automobile and the two-wheeled vehicle according to the present invention is an engine exhaust manifold or a joint part interposed between an exhaust pipe and a single downstream exhaust pipe,
(A) The joint portion guides and straightens the rotation of the exhaust gas flow from the engine into the straight inflow portion where the exhaust gas flow flows in and goes straight, and the combined exhaust gas flow where the exhaust gas flow from the straight flow portion joins. It is structured into an integral hollow three-dimensional object consisting of a rotation induction part that flows the combined exhaust gas flow out to a single exhaust pipe on the downstream side ,
(B) The inflow straight part is a short tube assembly in which a plurality of short tubes are bundled in parallel and in the same direction.
The direction of the exhaust gas flow that goes straight through the short tube assembly and the outflow direction of the combined exhaust gas flow from the rotation induction portion are arranged in the same direction.
(B) the rotation guiding portion is configured in a space region extending from the boundary with the inflow straight portion to the outlet of the combined exhaust gas flow, the cross section of the boundary with the inflow straight portion has the same shape, and Twist to reduce the volume continuously and reach the outlet ,
(C) The inflow rectilinear portion and the rotation induction portion are structured such that the direction of the exhaust gas flow that goes straight through the short tube assembly and the outflow direction of the combined exhaust gas flow from the rotation induction portion 3 are the same direction. It is characterized by that.
[0010]
9 includes four exhaust pipes 91 (referred to as branch pipes in Patent Document 3) 91, 92, 93, and 94 connected to the engine at the center line 96 of the collecting pipe portion 95. The exhaust pipes 91, 92, 93, 94 adjacent to each other at a certain angle are arranged at a certain plane angle so as to merge at one confluence point C.
In the joint part 90, a complicatedly curved pipe line is formed from the engine cylinder to the joint part 90 in order to satisfy the arrangement conditions of the exhaust pipes 91, 92, 93, 94.
[0011]
Problems to be Solved by the Invention
As for the joint part of the exhaust system of automobiles and motorcycles, when a component concentration detection device is disposed substantially at or near the joint part, there is substantially a proposal for equalizing the components of the target exhaust gas flow. The main thing. Therefore, in the conventionally proposed joint portion, there are basic problems represented by the following (i) to (iv) regarding the relationship between the joint portion, the engine performance, and the exhaust device. (I) The conventional joint portion 90 has a problem that the exhaust gas flow is not smoothly joined and the passage time is long, so that it does not contribute to improvement of engine output and fuel consumption.
(Ii) Since the conventional joint portions 80 and 90 bend and connect a plurality of exhaust pipes connected thereto, and the eddy current is generated in the exhaust gas flow by the bending, only a weak vortex flow is generated, and the engine output・ There was a problem that eddy currents directly related to improved fuel efficiency could not be obtained.
(Iii) Since the conventional joint portion 90 connects a plurality of upstream exhaust manifolds or exhaust pipes according to two kinds of angle conditions, the arrangement of the exhaust manifolds or exhaust pipes is complicated, There has been a problem that the pressure loss of the exhaust gas flow increases, the vibration increases, and the maintenance becomes complicated.
(Iv) In the conventional joint sections 80 and 90, when the number of exhaust manifolds or exhaust pipes on the upstream side changes, it is necessary to change the inflow angle, and it is complicated to set the optimum angle.
[0012]
Therefore, the present inventor has created a technical idea relating to a novel joint part aimed at the following (A) to (E).
(A) An object of the present invention is to provide a joint portion that enables the exhaust gas flow to be merged and swirled to improve engine output and fuel consumption.
(B) Another object of the present invention is to provide a joint part that reduces the pressure loss of the exhaust gas flow in the exhaust pipe system including the joint part.
(C) Another object of the present invention is to provide a joint part that reduces vibrations in the exhaust pipe system including the joint part.
(D) Another object of the present invention is to provide a joint part that improves the strength of the exhaust pipe system including the joint part.
(E) Another object of the present invention is to provide a joint part that facilitates attachment and maintenance of an exhaust device including the joint part.
[0013]
[Means for Solving the Problems]
The joint portion used in the exhaust system of the automobile and the motorcycle according to the present invention includes a plurality of upstream exhaust manifolds or exhaust pipes communicating with the engines of the automobile and the motorcycle, and a single downstream exhaust pipe. Is a joint part that joins exhaust gas flows flowing in from the upstream side into a single exhaust gas flow and flows out to the downstream side,
A plurality of exhaust gas flows are parallel to each other, and flow into the inside in the same direction as the exhaust gas flow flowing out from the joint portion, and have a structure in which the combined exhaust gas flow flows out while rotating, It is characterized by.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be specifically described with reference to FIGS. Although the embodiment illustrated in FIGS. 1 to 7 is a preferred embodiment of the present invention, it is only a part of various embodiments included in the present invention. In addition, in each following figure, what attached | subjected the same code | symbol has shown the same or equivalent thing.
[0015]
FIG. 1 is a perspective view of a joint portion used in an exhaust device of a four-cylinder engine of an automobile and a two-wheeled automobile. The joint portion 1 shown in FIG. 1 is formed of an integral hollow three-dimensional object made of a casting, and an inflow rectilinear portion (indicated by hatching in FIG. 1) for individually flowing in and straightly moving an exhaust gas flow from the upstream side. 2 and a rotation induction section 3 that induces rotation in the combined exhaust gas flow to generate a vortex flow and flows out to the downstream exhaust pipe.
[0016]
The inflow straight section 2 brings together four short tubes arranged in parallel in the most intimate contact state, and connects and fixes adjacent portions of each short tube (see reference numerals 30, 30, 30, and 30 in FIG. 3). The short tube assembly is structured such that the direction of the exhaust gas flow that goes straight through the short tube assembly and the outflow direction of the combined exhaust gas flow from the rotation induction unit 3 are the same. Upstream four exhaust manifolds or exhaust pipe connection ends are inserted and connected to the short tube assembly opening 4, 4a, 4b, 4c, and the upstream exhaust gas flow is They go straight (that is, they also go straight through the inflow straight part 2) and flow into the rotation induction part 3 to become a combined exhaust gas flow. The flat central portion of the short tube assembly opening 4, 4, 4a, 4b, 4c and the flat central portion of the outlet 5 of the rotation guide 3 are on the same axis, and the outlet 5 and the opening 4, 4a, It exists opposite to 4b and 4c.
Therefore, the upstream exhaust gas flow minimizes the pressure holding loss, retains the kinetic energy, becomes the combined exhaust gas flow at the rotation induction unit 3, and the rotation is induced by the retained kinetic energy. Then, it flows out from the outlet 5 to the downstream side in a short stay time.
[0017]
The rotation guiding portion 3 is a spatial region from the boundary 6 with the inflow straight traveling portion 2 to the outlet 5 and is a spatial region corresponding to the perspective view of the joint portion 1 shown in FIG. The portion corresponding to the boundary 6 with the inflow rectilinear portion 2 in the rotation guiding portion 3 has the same shape as the outer shape of the cross section of the short tube assembly of the inflow rectilinear portion 2 (the plane orthogonal to the straight direction of the exhaust gas flow). Thus, the upstream exhaust gas flow smoothly flows from the inflow straight portion 2 into the rotation guide portion 3. In addition, the space region from the boundary 6 to the outlet 5 is continuously twisted by twisting the outer shape of the portion corresponding to the boundary 6 (that is, the same shape as the outer shape of the cross section of the short tube assembly). It has a form that reaches the outflow port 5 by making it smaller. In other words, the convex portion having four roundnesses of the short tube assembly of the straight inflow portion 2 is gently twisted to the outlet 5 while maintaining continuity. Therefore, the exhaust gas flow is smoothly merged exhaust gas flow at the rotation induction portion 3, and continuously and forcibly due to the continuous reduction of the convex portions having four twisted roundness of the rotation induction portion 3. A large rotational movement is induced and flows out from the outlet 5 to the downstream exhaust pipe.
[0018]
The boundary 6 between the rotation guide part 3 and the inflow straight part 2 is a place where the boundary from the opening 4, 4 a, 4 b, 4 c of the inflow straight part 2 is more confluent than the center in the length direction of the joint part 1. The engine output can be improved by inducing a large rotational motion in the gas flow. A large rotational motion can be imparted even if the twist angle of the outer shape of the rotation guiding portion 3 is, for example, about 28 to 80 degrees. FIG. 2 schematically illustrates a situation in which the exhaust gas flow flows in and straightly into the inflow straight portion 2 and flows into the rotation guide portion 3 where the combined exhaust gas flow is guided to rotate and travels toward the outlet 5. FIG.
[0019]
FIG. 3 is an explanatory view of the joint portion 1 shown in FIG. 1 viewed from the open ports 4, 4a, 4b, and 4c of the short tube assembly, and FIG. 4 shows the joint portion 1 shown in FIG. It is explanatory drawing seen from. 3 and 4, it can be seen that the inside of the rotation guiding portion 3 is formed on the uneven surface opposite to the outer surface of the rotation guiding portion 3 in FIG. 1.
[0020]
In addition, in FIGS. 1-4, although the case where the inflow straight part 2 was comprised from four short pipes was demonstrated, in this invention, there is no restriction | limiting in particular about the number of the short pipes which comprise the inflow straight part 2, For example, two or six can be used.
[0021]
FIG. 5 is an explanatory view showing a joint portion in the case where there are two short pipes constituting the straight inflow portion 2, and FIG. 6 is a joint portion in the case where there are six short pipes constituting the straight inflow portion 2. It is explanatory drawing which shows.
[0022]
The joint portion 1 of the present invention has the following special performances (1) to (6) depending on its configuration.
(1) The joint portion 1 exhibits an improvement in engine performance even experimentally due to its configuration. FIG. 7 shows the results of the engine performance test performed using the exhaust device having the joint portion 1 interposed therebetween. The hatched area in FIG. 7 is an area where the engine performance is improved by using the joint portion 1. The joint part tested for comparison is still in practical use even in the shape of a substantially truncated cone. In addition, the joint portions 80 and 90 have complicated piping settings and are lower than the joint portions subjected to the comparative test.
(2) Since the upstream exhaust manifold or the exhaust pipe distribution pipe system can be arranged in a straight line or approximate condition, the pressure loss reduction, vibration reduction, exhaust gas noise reduction of the entire exhaust pipe system In addition, it is possible to easily improve the strength.
(3) Maintenance of the entire exhaust pipe system is easy.
(4) Even if the number of exhaust manifolds or exhaust pipes on the upstream side changes, the joint portion 1 is forced to rotate by using the straight kinetic energy of the exhaust gas flow, so that the same vortex flow It is possible to let it flow out.
(5) Since the exhaust gas flow on the upstream side goes straight in the joint part 1 and flows out downstream, the residence time in the joint part 1 is shortened.
(6) Since the inflow rectilinear portion 2 is made of a casting and has a structure whose strength is increased as a whole (for example, the structure of the rotation guide portion 3), the upstream piping system can be easily held.
[0023]
In the present invention, it is in accordance with the object of the present invention, and any modification or partial change and addition is optional as long as the effects of the present invention are not particularly impaired. It is. In addition, although this invention is demonstrated concretely based on an Example, an Example is an illustration and does not restrain this invention.
[0024]
【The invention's effect】
According to the joint portion of the present invention, various effects represented by the following (a) to (h) can be obtained.
(A) Engine efficiency is improved.
(B) Pressure loss of the exhaust gas flow in the exhaust pipe system is reduced.
(C) The vibration of the exhaust pipe system is reduced.
(D) Fuel consumption decreases.
(E) The possibility of noise generation due to the exhaust gas flow is reduced.
(F) The strength of the exhaust device is improved.
(G) Maintenance of the exhaust device is facilitated.
(H) From the structure, the joint portion can be made strong.
[Brief description of the drawings]
FIG. 1 is a perspective view of an example of an embodiment of a joint portion of the present invention.
FIG. 2 is an explanatory view schematically showing the movement of the exhaust gas flow at the joint.
FIG. 3 is an explanatory view of the joint portion shown in FIG. 1 viewed from the opening of the short tube assembly.
FIG. 4 is an explanatory view of the joint portion shown in FIG. 1 as viewed from the outlet of the rotation guiding portion.
FIG. 5 is an explanatory view showing a joint portion in the case where there are two short pipes constituting the straight inflow portion.
FIG. 6 is an explanatory view showing a joint portion in the case where there are six short pipes constituting the straight inflow portion.
FIG. 7 is a diagram showing engine performance test results.
FIG. 8 is an explanatory diagram of a conventional joint portion.
FIG. 9 is an explanatory view of another conventional joint portion.
[Explanation of symbols]
1 Joint part 2 Inflow straight part 3 Rotation induction part 4 Opening port
4a Open port 4b Open port 4c Open port 5 Outlet 6 Boundary

Claims (5)

A joint part interposed between an exhaust manifold or exhaust pipe of an engine and a single exhaust pipe on the downstream side;
(A) The joint portion is an integrated hollow three-dimensional object in which the inflow straight portion that allows the exhaust gas flow to flow in and straight and the rotation guide portion that causes the combined exhaust gas flow generated by the straight exhaust gas flow to flow out in a vortex flow form. And
(B) The inflow straight part is a short tube assembly in which a plurality of short tubes are bundled in parallel and in the same direction,
The direction of the exhaust gas flow that goes straight through the short pipe and the outflow direction of the combined exhaust gas flow from the rotation induction section are the same direction,
(C) The rotation guiding portion is a space region that communicates with the inflow straight portion extending from the boundary with the inflow straight portion to the outlet of the combined exhaust gas flow, and has the same cross section at the boundary with the inflow straight portion. And communicated with the inflow straight part, twisted to continuously reduce the volume and reach the outlet,
(D) The inflow rectilinear portion and the rotation induction portion have a structure in which the direction of the exhaust gas flow that goes straight through the inflow rectilinear portion and the outflow direction of the combined exhaust gas flow from the rotation induction portion are the same direction; The joint part used for the exhaust apparatus of the motor vehicle and two-wheeled motor vehicle characterized by these. 2. The joint portion according to claim 1 , wherein the straight inflow portion includes two, four, or six short tube assemblies. The joint portion, the joint portion according to claim 1 or 2 consisting of a hollow three-dimensional-like material by casting. The joint part according to any one of claims 1 to 3 , wherein the joint part is provided with a boundary between the inflow straight part and the rotation guide part closer to the inflow straight part from a center in a length direction of the joint part . The rotation guide part is a joint part according to any one of 1 to 4 , in which a twist angle of an outer shape thereof is in a range of 28 to 80 degrees.

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