JP4759705B2 - Manufacturing method of different diameter pipe parts - Google Patents

Description

The present invention, for example, the appropriate when used for a motorcycle exhaust system pipe, a method for producing a different-diameter pipe channel piece.

  For example, a motorcycle exhaust system pipe section, that is, a pipe section from an exhaust pipe to a muffler unit called a muffler is required to have a number of functions laid out in a compact layout. In addition to these, there is also a demand for an exhaust gas purification function of an internal combustion engine at a high level because of a demand for reducing the environmental load.

  In response to this situation, a catalyst unit is provided in the exhaust system pipe section to remove harmful exhaust components that give an environmental load. As one of the ideas for the catalytic unit to work efficiently, a method of installing two systems of the catalyst unit in series in the middle of the pipeline at a predetermined interval is adopted. In this case, in order to perform the operation of the catalyst unit more effectively, it is preferable that the pipe part connecting the front and rear relatively large-diameter catalyst units is a different-diameter pipe whose middle is narrowed down to a small diameter, In addition, a branch pipe capable of introducing outside air is attached to the small diameter portion.

The conventional configuration of such a different-diameter pipe part is as shown in FIG. 10, and the different-diameter pipe part 100 includes an upstream taper / pipe piece 101, a distance pipe piece 102, and the other end. The taper piece 103 constituting the side, the branch pipe piece 104 branched from the small-diameter portion, and four members are provided, and these are integrally assembled.
Of course, if you look at each of the processed parts, the pipe ends will be subjected to various processing such as diameter expansion processing and taper processing, and considering all these processing steps, In the production of road parts, there was a certain limit to the reduction of processing costs.

The present invention has been made in consideration of such a technical background, and has a reduced number of parts, a simple machining process, and different diameter pipe parts that can cope with various design variations . The technical issue is to develop a manufacturing method.

The manufacturing method of the different-diameter pipe component according to claim 1 has a large-diameter portion connected to the catalyst unit at both ends, a small-diameter portion is formed between each large-diameter portion, and the small-diameter portion and the large-diameter portion are large. A pipe part in which one or a plurality of introduction holes are formed is formed by connecting the diameter part to each other by a taper part and further selecting either one or both of the taper part and the small diameter part. in producing by pressing using the device, the starting material have a substantially equal diameter as the large diameter portion, and using a pre-metal pipe preliminary holes are formed for introducing hole forming, whereas, the molding apparatus A mandrel having an inner diameter of the small diameter portion, the large diameter portion, and the taper portion as an outer diameter, an introduction hole regulating pin for forming the introduction hole, and an outer dimension of the small diameter portion, the large diameter portion, the taper portion, and the introduction hole . Divided into multiple parts with molded recesses Using those equipped with a press die which, by hold down the starting material by a die in a state of inserting the introduced restriction pin into the preliminary hole is inserted the mandrel into the starting material, a small diameter portion, the large-diameter This rib is plastically deformed so as to form a tapered portion, and a rib-shaped portion is formed by deforming a part of the remaining starting material in the tapered portion and the small-diameter portion so as to protrude outwardly. The shape portion is characterized in that the introduction hole is formed so as to join the range of the tapered portion and the small diameter portion without being crushed at the position of the introduction hole regulating pin .

The first According to the invention of claim 1, it is possible to process by molding integrally different diameter pipe channel piece metal pipe approximately equal diameter and large-diameter portion as a single starting material, as conventionally A plurality of component elements are manufactured, and the number of processes is less than that of a combination of them. In addition, the base material is more integrated than that of the conventional combination, so that the strength against heat and vibration is high. In particular, different-diameter pipe parts including introduction holes corresponding to the catalytic reaction characteristics of various catalyst units can be integrally formed without combining the parts and the like.

  The best examples of the present invention are disclosed in the following description of specific embodiments and drawings, and further include various variations developed based on the examples.

First, the peripheral members related to the different-diameter pipe part that is the production target of the present invention will be described.
In FIG. 1, reference numeral 1 denotes a different-diameter pipe line component, which is provided in a silencer unit 2 of a scooter type motorcycle M, for example.
In the case of such a scooter type, the engine unit E and the silencer unit 2 are provided relatively close to each other, so that the exhaust pipe 3 and the silencer unit 2 connected from the exhaust port of the engine unit E are integrated with each other. It is configured.
In the silencer body 20 that forms the outer shell of the silencer unit 2, a primary catalyst unit 21 is provided at a position continuous from the exhaust pipe 3, and the exhaust path further includes a different-diameter pipe part 1. To the secondary catalyst unit 22.
The silencer unit 2 has a plurality of silencer chambers 24 defined by a plurality of partition walls 23. The primary catalyst unit 21, the secondary catalyst unit 22, and the different-diameter pipe part 1 are also provided in the silencer chambers. 24 is provided so as to be incorporated into the interior of the body 24.

Next, the different diameter pipe line part 1 which is a manufacturing object of the present invention will be described.
The different-diameter pipe part 1 constitutes a long tubular pipe as a whole, and has large-diameter parts 11 at both ends thereof. A small-diameter portion 12 is provided between the large-diameter portions 11, and the large-diameter portion 11 and the small-diameter portion 12 are connected so that the tube diameter can be smoothly reduced by the tapered portion 13. Further, as an example, an introduction hole 14 is formed in the middle of the small diameter portion 12 so as to join the small diameter portion 12.

And the rib-shaped part 15 is formed so that it may protrude in the range of the longitudinal direction in which the small diameter part 12 and the taper part 13 are formed. As can be understood from the manufacturing method to be described later, the rib-shaped portion 15 itself is formed by squeezing the remaining portion generated in the starting material 10 to which the straight tubular metal pipe having substantially the same diameter as the large-diameter portion 11 is applied. It is what.
In addition, what is shown with the code | symbol 16 is a spot junction part for ensuring the crushing state of the rib-shaped part 15 which carried out the plastic deformation in the shape of a match.

  When such a different-diameter pipe part 1 is used, the primary catalyst unit 21 and the secondary catalyst unit 22 are respectively connected to both ends of the large-diameter portion 11, and from the introduction hole 14, For example, outside air is introduced and oxygen is sucked to contribute to the exhaust gas purification action, such as more effectively enhancing the action of the downstream secondary catalyst unit 22.

Next, the manufacturing method of the different diameter pipe line part 1 which is this invention is described. First, the starting material 10 of the different-diameter pipe part 1 is a straight pipe as shown in FIG. 2, and its diameter dimension D is the diameter dimension of the large-diameter portion 11 of the different-diameter pipe part 1 (this dimension is also denoted by reference numerals). D1)). Of course, when the diameter D of the starting material is smaller than that of the large-diameter portion, only the portion corresponding to the large-diameter portion 11 may be enlarged by the diameter-expansion processing prior to processing so that D≈D1. The range in which this diameter expansion is allowed can also be included in the concept of substantially equal dimensions.

On the other hand, as shown in FIG. 2, the molding apparatus 5 used for molding includes a mandrel 51 and a press die 52 divided into a plurality of parts.
First, the mandrel 51 is divided into two in the longitudinal direction as an example. Each of the mandrels 51 includes a large diameter restricting portion 511 at one end, a small diameter restricting portion 512 at the other end, and a taper restricting portion 513 therebetween. These have internal dimensions due to the processed shape of the different-diameter pipe part 1. Further, an introduction hole regulating pin 514 is installed in this direction in a direction orthogonal to the longitudinal direction of the starting material 10. Of course, in order to use the introduction hole regulating pin 514, the introduction preliminary hole 14a for forming the introduction hole 14 is previously opened to the starting material 10 by a technique such as drilling or piercing punch.

  On the other hand, the press mold 52 is one that presses the circular starting material 10 from the outside and plastically deforms it, and is constituted by a two-part mold of an upper mold 52A and a lower mold 52B as an example. Of course, when the shape becomes more complicated, the number of molds to be divided may increase. In each of the upper mold 52A and the lower mold 52B, a large-diameter press portion 521, a small-diameter press portion 522, and a taper press portion 523 are formed in a recessed state, and an introduction hole is formed so as to join the small-diameter press portion 522. A press part 524 is formed. Further, the mold is somewhat recessed so as to spread outside the small-diameter press part 522 and the taper press part 523, and a rib-like part escape part 525 is formed.

In order to form the starting material 10 up to the different-diameter pipe part 1 by such an apparatus, the mandrel 51 is inserted into the starting material 10 from both ends of the starting material 10, and the introduction hole regulating pin 514 is further inserted. In combination, the press mold upper mold 52A and the lower mold 52B are brought close to each other and press-molded.
As a result, as shown in FIGS. 3A to 3C, the starting material 10 has a part of the starting material 10 as a remaining member, particularly when the small diameter portion 12 and the tapered portion 13 are reduced in diameter. A thing spreads in the rib-shaped part escape part 525 in the press die 52, and is plastically deformed into a flat plate shape in a mating manner to form the rib-shaped part 15.
Then, at the position of the introduction hole regulating pin 514, the rib-like portion 15 is formed in a pipe shape without being crushed, and the introduction hole 14 is shaped so as to join the small diameter portion 12.

[Other Examples]
The present invention has the above-described embodiment as one basic technical idea, but the following modifications are possible.
That is, what is shown in FIG. 4 shows various forming methods of the large diameter part 11 and the small diameter part 12, and the thing shown in FIG. 4A is that the small diameter part 12 extends in the longitudinal direction of the entire pipe part. It is not provided at the center, but at a position that is somewhat unevenly distributed on one side. By the way, in the case of such a technical idea, even if the starting material 10 is a straight tube, it is somewhat curved as a whole as shown in FIG. It can be a shape. Of course, in the case of the different-diameter pipe part 1 bent in this way, the starting material 10 bent in advance as shown in FIG. 4C may be applied.

  Further, in the embodiment shown in FIG. 5A, when the small diameter portion 12 is formed, the merging surface with the tapered portion is symmetrically shifted from the center, and the small diameter portion is formed in a somewhat zigzag shape. Furthermore, the embodiment shown in the figure also discloses a technical idea of providing two introduction holes 14.

Further, the formation method of the small diameter portion 12 and the tapered portion 13 will be described. As shown in FIG. 5B, the entire length is formed by the tapered portion 13 with the dimension in the longitudinal direction of the small diameter portion 12 being extremely narrow. It is also possible to adopt such a form.
In the embodiment shown in FIG. 5C, the small-diameter portion 12 itself is not equal in diameter but is somewhat tapered.

  Further, in the embodiment shown in FIG. 6, the large diameter portion 11 is not equal in diameter to the large diameter portions at both ends, and one large diameter portion 11 (particularly indicated by reference numeral 11A) is replaced with the other large diameter portion. The diameter is smaller than (indicated by reference numeral 11B). Of course, in this case, the rib-like portion 15 is also partially formed outside the large-diameter portion 11A having a relatively small diameter.

Further, as an example of the small diameter portion 12, the embodiment shown in FIG. 7 is such that the confluence shape of the small diameter portion 12 and the introduction hole 14 is not obliquely crossed but somewhat obliquely crossed.
In this case, the introduction hole 14 does not necessarily have to be a circular hole, and a swirl flow (indicated by a broken line arrow A) is generated in the outside air that is configured in a semicircular shape or the like as shown in the figure. May be.
In addition, in order to generate such a swirl flow more positively, as shown in FIG. 8A, by devising a split surface between the upper mold 52A and the lower mold 52B of the press mold 52, a small diameter portion is obtained. It is also possible to press 12 to some twisted shape.

In addition, the embodiment shown in FIG. 8B is a device related to the rib-like portion 15, and the rib-like portion 15 itself is formed in a somewhat spiral shape by the shape design of the mold. It is also possible to have an effect of causing a change in the flow of the exhaust gas flowing outside the radial pipe part 1.
Further, the embodiment shown in FIG. 9 does not leave the rib-like portion 15 as it is. For example, when a lighter weight is required, a part of the rib-like portion 15 is removed as shown in FIG. It is made to remove in a subsequent processing process.
In this case, it is preferable to perform welding on the entire circumference of the pipe line regulating side range 15a of the rib-like portion 15 by seam welding or the like. Further, it is possible to reduce the weight by a simple meat removal method as shown in FIG.

A different diameter pipe passage parts made according to the present invention, is an explanatory diagram showing together the usage of it. It is a perspective view which shows the manufacturing method of the different diameter pipe line components of this invention. It is sectional drawing same as the above, and shows the method of carrying out preliminary diameter expansion processing collectively. It is a side view which shows the other Example of the different diameter pipe line components manufactured by this invention. It is a side view which shows the further another Example of the different diameter pipe line components manufactured by this invention. It is a side view which shows the further another Example of the different diameter pipe line components manufactured by this invention. It is a side view which shows the further another Example of the different diameter pipe line components manufactured by this invention. It is a side view which shows the further another Example of the different diameter pipe line components manufactured by this invention. It is a side view which shows the further another Example of the different diameter pipe line components manufactured by this invention. It is a side view which shows the conventional structure of a different diameter pipe line part, and the conventional manufacturing method.

DESCRIPTION OF SYMBOLS 1 Different diameter pipe parts 10 Starting material 11 Large diameter part 12 Small diameter part 13 Tapered part 14 Introduction hole 14a Introduction spare hole 15 Rib-like part 15a Pipe line regulation side range 16 Spot weld part 2 Silencer unit 20 Silencer body 21 Primary Catalyst unit 22 Secondary catalyst unit 23 Partition 24 Silencer chamber 3 Exhaust pipe 5 Molding device 51 Mandrel 511 Large diameter restricting portion 512 Small diameter restricting portion 513 Taper restricting portion 514 Introduction hole restricting pin 52 Press die 52A Upper die 52B Lower die 521 Large diameter press part 522 Small diameter press part 523 Taper press part 524 Introduction hole press part 525 Rib-like part relief part 100 (conventional type) Different diameter pipe parts 101 Taper / pipe piece 102 Distance piece 103 Taper piece 104 Branch pipe D Starting material Diameter D1 diameter ( Diameter portion)
D2 Diameter (small diameter part)
E Engine unit M Motorcycle A Rotating flow (outside air side)

Claims (1)

A large-diameter portion connected to the catalyst unit at both ends, a small-diameter portion is formed between each large-diameter portion, and the small-diameter portion and the large-diameter portion are connected by a tapered portion, and the taper In selecting a position of either one or both of the portion and the small diameter portion and producing a pipe part in which one or a plurality of introduction holes are formed by pressing using a molding device,
Said starting material have a substantially equal diameter as the large diameter portion, and using a pre-metal pipe preliminary holes are formed for introducing hole forming,
On the other hand, the molding apparatus includes a mandrel having an inner diameter of a small diameter portion, a large diameter portion, and a tapered portion, an introduction hole regulating pin for forming the introduction hole, a small diameter portion, a large diameter portion, and a tapered portion. Using a press die that is divided into a plurality of molds that have a molding recess that reproduces the outer dimensions of the introduction hole ,
By inserting a mandrel into the starting material and pressing the starting material with a mold with an introduction regulating pin inserted into the preliminary hole , plastic deformation is performed to form a small diameter portion, a large diameter portion, and a tapered portion. In addition, a part of the remaining starting material in the tapered portion and the small diameter portion is deformed so as to protrude outwardly in a mating manner to form a rib-shaped portion, and this rib-shaped portion is at the position of the introduction hole regulating pin. A method for producing a different-diameter pipe part characterized in that the introduction hole is formed so as to join the range of the tapered part and the small-diameter part without being crushed .

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