JP3333141B2 - Manufacturing method of silencer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing a silencer.

[0002]

2. Description of the Related Art Conventionally, in a silencer of an internal combustion engine, as shown in FIG. 10, a partition wall 101, an inner tube 102, and an inlet are provided in an outer cylinder 100 in which a thin metal plate is wound in a single layer or multiple layers. There is one in which the internal structure combining the pipe 103 and the outlet pipe 104 is housed, and the end plates 105 and 106 and the end 107 of the outer cylinder 100 are fixed by caulking (plastic working). However, there is a problem that both the airtightness and the strength are low.

[0003] Although not for an internal combustion engine, as shown in FIG. 11, a partition 201 is provided inside an outer cylinder 200, and both ends of the outer cylinder 200 are reduced in diameter by spinning using a spinning roller 202. A technique for manufacturing a silencer is disclosed. According to this technology, the outer cylindrical portion 203, the reduced diameter portion 2
Since the components 04 and 205 and the necks 206 and 207 are integrally formed by a single plate, the problems of airtightness and strength can be solved.

[0004]

By the way, in a silencer for an internal combustion engine, it is necessary to house an internal structure as shown in FIG. 10, and furthermore, a connection is made to the front and rear of the outer cylinder (both necks at both ends). It is necessary to fit an inlet pipe or an outlet pipe for the inner pipe, and furthermore, the inlet pipe or the outlet pipe is often eccentric (offset) or inclined with respect to the center axis of the outer pipe.

Therefore, the manufacturing technique shown in FIG. 11 cannot be directly applied to a method for manufacturing a silencer for an internal combustion engine. From such a fact, in the silencer of the internal combustion engine having the inlet pipe and the outlet pipe as described above,
There has been a need for a technology that can integrally form the outer cylinder, the end plate, and the neck.

Accordingly, an object of the present invention is to provide a method for manufacturing a silencer that meets the above craving.

[0007]

In order to solve the above problems BRIEF SUMMARY OF THE INVENTION first invention according to claim 1, it has a inlet pipe and outlet pipe, the inlet pipe and A
At least one shaft center of the outlet pipe and the shaft center of the outer cylinder
DOO is, the eccentric and / or inclined position Ru relationship near the inner structure, the opened inserted or pressed into the outer cylinder, the open end of the outer tube eccentric spinning and / or tilt spin <br / A neck portion is formed at the distal end of the reduced diameter portion by a thinning process, and the neck portion is fitted to the outer periphery of the inlet pipe and / or the outlet pipe.

According to a second aspect of the present invention, the inner structure is inserted or press-fitted into the opened outer cylinder, and the opening end of the outer cylinder is reduced in diameter by eccentric spinning and / or inclined spinning. Then, a neck is formed at the tip of the reduced diameter portion, and thereafter, an inlet pipe and an outlet pipe are provided at the neck, and at least one of the axis and the axis of the outer cylinder are eccentric.
And / or fixed to the internal structure with an inclined positional relationship .

According to a third aspect of the present invention, in the first or second aspect, the inlet pipe and the outlet pipe are integrally formed.

According to a fourth aspect of the present invention, an inlet pipe and an outlet pipe integrally connected via a bendable flexible joint portion are inserted into an open outer cylinder,
Eccentric spinning and / or tilting the open end of the outer cylinder
The oblique spinning process reduces the diameter to form a neck at the tip of the reduced diameter portion, and fits the neck around the outer circumference of the inlet pipe and / or the outlet pipe.
And at least one shaft center of the outlet pipe and the outer cylinder
The shaft center is in an eccentric and / or inclined positional relationship.
It is characterized in that it has to be.

[0011] A fifth invention according to claim 5, at least one of Yi emissions Rett pipe and outlet pipe, and the axis of the axis and the outer cylinder is placed in the eccentric and / or inclined position relationship As described above, the opening end of the outer cylinder is reduced in diameter by eccentric spinning and / or inclined spinning to form a neck at the tip of the reduced diameter portion, and the neck is formed into an inlet pipe and / or It is characterized by being fitted to the outer periphery of an outlet pipe.
Sixth invention is according to claim 6, at least one of the inlet pipe and outlet pipe, and inserted into the opened outer tube, the open end of the outer tube eccentric spinning and /
Alternatively, the diameter is reduced by inclined spinning to form a neck at the tip of the reduced diameter portion, and the neck is connected to an inlet pipe and / or
Or by fitting the outer circumference of the outlet pipe, inlays
At least one of the outlet pipe and outlet pipe
Position where the core and the axis of the outer cylinder are eccentric and / or inclined
It is characterized by being put into a relationship . Seventh invention of claim 7 is polarized the open end of the outer tube
The diameter is reduced by core spinning and / or inclined spinning to form a neck at the tip of the reduced diameter portion.
An inlet pipe and / or an outlet pipe are fitted inside the neck and fixed , and the inlet pipe and the outlet pipe are connected.
At least one shaft center of the cut pipe and the shaft center of the outer cylinder,
To be in eccentric and / or inclined relationship
It is characterized by having done.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described based on an embodiment shown in FIGS. FIGS. 1 and 2 show an example of a spinning machine applied to the manufacturing method of the present invention. First, the spinning machine will be described.

On the base 1, a work clamping device 2 is located on one side, and a roller device 3 is located on the other. In the work clamp device 2,
Two rails 4 are arranged on the base 1 (this direction is defined as a Y direction, and the rails 4 are hereinafter referred to as Y direction rails 4).
). A table 5 is mounted on the Y-direction rail 4 so as to be able to reciprocate in the Y-direction. A first ball spline shaft 6 is arranged on the base 1 in the Y direction, and the first ball spline shaft 6 is configured to be rotated forward and backward by a first motor 7 as a driving unit. Further, a boss (not shown) provided on the lower surface of the table 5 is screwed to the first ball spline shaft 6 so that the table 5 reciprocates in the Y direction by forward and reverse rotation of the first ball spline shaft 6. Has become.

On the table 5, a second driving means is provided.
A motor 8 and a rotary drive shaft 10 that rotates in a plane by the second motor 8 via a gear in a gear box 9 are provided. The clamp device 11 is a lower clamp 1 divided into two parts.
2 and an upper clamp 13, and the rotary drive shaft 10 is fixed to the lower clamp 12, and the whole of the clamp device 11 becomes a vertical axis Z (this is defined as a Z axis) by forward and reverse rotation of the rotary drive shaft 10. It rotates forward and backward around the center.
The upper clamp 13 of the clamp device 11 is moved up and down by a driving means 14 such as a hydraulic cylinder.
And to hold the workpiece mounted on the axis X ₁ by a semicircular clamping surface 12a of the lower clamp 12, thereby making it possible to remove the workpiece by the rise of the upper clamp 13.

Next, the roller device section 3 will be described. On the base 1, a direction X orthogonal to the Y-direction rail 4.
A rail 15 (hereinafter referred to as an X-direction rail 15) is disposed in this direction (hereinafter referred to as an X direction). A case 16 is mounted on the X-direction rail 15 so as to be able to reciprocate in the X direction. Further, a second ball spline shaft 17 is arranged on the base 1 in the X direction, and the second ball spline shaft 17 is rotated forward and reverse by a third motor 18 as a driving means. Further, a boss 19 provided on the lower surface of the case 16 is screwed to the second ball spline shaft 17, and the case 16 reciprocates in the X direction by the forward / reverse rotation of the third motor 18. ing.

A hollow main shaft 20 is provided in the case 16.
The axis X _{2 is set} to the clamp axis X of the clamp device 11.
It is arranged at the same height as ₁ horizontally in the X direction and is rotatably supported by bearings 21 and 22. The main shaft 20 is rotated in one direction via a pulley 24, a belt 25, and a pulley 26 by a fourth motor 23 as a driving unit. A roller holder 27 is provided on the main shaft 20 on the side of the work clamping device 2.
Is fixed, and the rotation of the main shaft 20 causes the roller holder 27 to rotate about the axis X ₂ of the main shaft 20.

A trajectory changing means for changing the rotation trajectory of the roller is provided in the case 16. The trajectory changing means includes a cylinder 29, which is a driving means held on the case 16 by a bracket 28, and a cylinder 29. A ring plate 3 provided at the tip of the rod 30 in the roller holder 27 so as not to hinder the rotation of the roller holder 27.
It consists of 1. The ring plate 31 is connected to the main shaft 20.
, And the inner surface of the tip is formed as a tapered surface 31a which spreads outward.

In the roller holder 27, a plurality of brackets 32, in the embodiment shown in the figure, three brackets 32 are arranged with their axes in the X direction, and are arranged at equal intervals in the circumferential direction of the roller holder 27. Each bracket 32 is provided so as to be movable in a radial direction about the axis X ₂ of the roller holder 27. Furthermore, the roller holder 2 of each bracket 32
7, a taper surface 32a is formed along the taper surface 31a, and a roller 33 is provided at an outer end of each bracket 32.
It is provided so that it can rotate (rotate) freely.

The rotation of the main shaft 20 causes the roller holder 27 to rotate around the axis X ₂ , and accordingly, the bracket 32 and the rollers 33 revolve around the axis X ₂ . Here, the ring plate 31 in the roller holder 27 does not rotate because it is supported by the case 16 side, and the tapered surface 31
a and 31b relatively rotate and slide.

Although not shown, each of the brackets 3
2 is provided with a means for constantly biasing the roller holder 27 to the outer peripheral side thereof, for example, a return spring.
The forward movement (leftward in FIG. 1) of the ring plate 31 by the cylinder 29 causes the respective brackets 32, ie, the respective rollers 33, to revolve in the axial direction of the main shaft 20 by the relative rotational sliding of the two tapered surfaces 31a and 32a. When the ring plate 27 is closed by the same amount and the ring plate 27 is moved backward (to the right in FIG. 1), the bracket 32, that is, each roller 3 is moved by the tapered surfaces 31a, 32a and the return spring.
3 moves outward by the same amount.

A mandrel 34 is coaxially held in the main shaft 20 by bearings 35 and 36 so as to be rotatable and relatively movable in the X direction. The mandrel 34 is reciprocated in the X direction by the cylinder 38 irrespective of the main shaft 20. Further, the outer diameter of the tip portion 34a of the mandrel 34 is formed to be substantially the same as the inner diameter of the final shape of the neck portion of the work (outer cylinder) to be drawn and described later.

Next, a method of manufacturing the silencer of the present invention using the spinning machine will be described. FIG. 3 shows a first embodiment of the manufacturing method of the present invention.

First, as shown in FIG.
a first partition 43 in which an inlet pipe 40, a first inner pipe 41, and an outlet pipe 42, in which a small hole 42a is formed, are inserted or press-fitted into a burring hole, the inlet pipe 40, the second inner pipe 44, and the outlet. The internal structure 47 is assembled by the second partition wall 45 in which the pipe 42 is inserted or pressed into the burring hole and the third partition wall 46 in which the outlet pipe 42 is inserted or pressed into the burring hole.

Next, each partition 43, 4 of the internal structure 47
As shown in FIG. 3B, the inner structure 47 is mounted in the outer tube 48 by inserting or press-fitting the inner structure 47 into the outer tube 48, and the distal end portion 40 b of the inlet pipe 40 and the outlet pipe The rear end 42b of the 42 is slightly protruded from the end surface of the outer cylinder 48. If necessary, the partition walls 43,
The outer tubes 45 and 46 are fixed to each other by spot welding or the like.

Next, the outer cylinder 48 is set on the lower clamp 12 of the clamping device 11 and the upper clamp 13 is lowered to firmly clamp the outer cylinder (work) 48 at a predetermined position so that it cannot rotate. Then, the table 5 is adjusted in the Y direction so that the axis X ₁ of the outer cylinder 48 is located on an extension of the main axis X ₂ , and the Z axis of the clamp device 11 is adjusted to rotate the outer cylinder 48 in the X direction. Turn to.

In this embodiment, the mandrel 34 is retracted to the right in FIG. 1 so as not to hinder spinning. Next, the third motor 18 is driven to advance the case 16 in the X direction (to the left in FIG. 1), and the roller 33 is moved to the diameter reduction start point A of the spinning process at one end of the outer cylinder 48. Position. Each roller 3
Numeral 3 is open to the outside of the outer diameter of the outer cylinder 48.
Then, the first motor 7 is driven to move the outer cylinder 48 to the position shown in FIG.
Move the arrow Y 'direction (c), the axis X ₃ (X ₁₎ of the rotation axis X ₂ and the outer cylinder 48 of the roller 33 and is in the state of being eccentric (offset) from each other.

Next, the fourth motor 23 is driven to drive the spindle 20
Is rotated in one direction, and each roller 33 revolves in one direction together with the roller holder 27. Further, the ring plate 31 is advanced by the cylinder 29 along with the revolving motion to close the revolving locus of each roller 33 toward the center of the outer cylinder 48, and each roller 33 is driven by the third motor 18.
Is retracted to the right in FIG. 1 along the X direction.

As a result, each roller 33 revolves while pressing itself against the outer peripheral surface of the outer cylinder 48 while rotating, and one end of the outer cylinder 48 is tapered as shown in FIG. 3C. . This diameter reduction, diameter reduction of the outer tube 48 in the Y 'direction of the tapered surface 48a is large, the less diameter reduction opposite the tapered surface 48b, the axis X ₃ of the outer tube 48 and the eccentric A neck portion 48c that is in close contact with the (offset) distal end portion 42b of the outlet pipe 42 is formed.

The spinning process is performed by the roller 3
In the case of one-pass molding in which the diameter of the roller 33 is reduced to the neck portion 48c at one stroke by one retreat, the eccentricity and the diameter of the roller 33 are gradually reduced for each of a plurality of passes. You may earn and go. Considering the material processing limit of the outer cylinder 48 and the molding quality, multi-pass processing is desirable. Further, if the diameter reduction processing is performed in one pass not only when the roller 33 is retracted as described above but also when the roller 33 is advanced, the number of passes is two in advance and retreat, which is more efficient.

In the case of performing machining in a plurality of passes, the offset process is also performed in multiple stages, and the offset amount is gradually increased each time one pass is completed, and finally the rotation axis X ₂ of the roller 33 is connected to the outlet pipe. 42 axis X ₄ of the to match may be a diameter reduction of the finish.

When the spinning process is completed, the roller 33 returns to the original open state and separates from the outer cylinder 48, and the case 16 retreats (to the right in FIG. 1) and returns to the original state.

Next, when the spinning of one end is completed, the clamping of the outer cylinder 48 by the clamp device 11 is released, and the outer cylinder 48 is reversed in the front-rear direction.

This reversing operation may be manually reversed by the operator or may be reversed by grasping with a robot hand. The clamp device 11 itself may be rotated around the Z axis and inverted by driving.

After this reversal, the other end, which is the unprocessed side, is subjected to spinning in the same manner as described above to reduce the diameter to the tapered surfaces 48d, 48e as shown on the left side of FIG. A neck portion 48f that is in close contact with the distal end portion 40b of the second member is formed.

FIG. 3D shows a modification of the spinning process.
And the rear end portion 42b of the outlet pipe 42 and the axis X ₃ of the outer tube 48 are relatively inclined, the neck portion 48c along the distal end portion 40b and the rear end portion 42b, is obtained by bending form 48f .

In the manufacturing method shown in FIG. 3D, first, at the stage of assembling the internal structure 47 shown in FIG. 3A, the inlet pipe 40 is bent as shown in FIG. 3D is used as the outlet pipe 48 as shown in FIG.
After forming the tapered surface up to before the neck forming by the diameter reduction processing as shown in (A) to (C), the second motor 8 is driven to move the clamp device 11 to Z during the neck forming at the time of the spinning processing. The outer cylinder 48 is rotated about the shaft.
Is rotated in the direction of arrow B in FIG. 3D to form a muffler having an inlet pipe 40 and an outlet pipe 48 whose outer ends are bent as shown in FIG. 3D.

Also in this case, similarly to the eccentric spinning process, the diameter reduction step and the rotation step are each multi-stage, and
Processing may be performed so that the rotation (tilt) angle is increased by several degrees each time the diameter reduction processing pass is completed.

FIG. 4 shows a second embodiment of the manufacturing method of the present invention. The second embodiment shows a retrofit type manufacturing method in which the inlet pipe 40 and the outlet pipe 42 shown in the first embodiment are assembled after spinning.

First, the first partition 43 into which the first inner pipe 41 shown in FIG. 4A is inserted or press-fitted, the second partition 45 into which the second inner pipe 44 is inserted or press-fitted, and the third partition 43 shown in FIG.
As shown in FIG. 4B, the internal structure including the partition wall 46 is sequentially inserted or pressed into a predetermined position in the outer cylinder 48.

Next, both ends of the outer cylinder 48 are tapered to reduce the diameter by the same spinning as in the steps shown in FIGS. 3A to 3C. In this embodiment, the spinning is performed. The mandrel 34 of the machine is advanced (to the left in FIG. 1) by the cylinder 38, and its tip 34a is attached to the neck 4
8c and 48f are located in the outer cylinder 48 at the position where they are formed. As a result, the necks 48c and 48f are connected to the mandrel 34.
Is restricted by the outer peripheral surface of the tip portion 34a and is pressed by the roller 33, and the shape accuracy of the neck portions 48c and 48f is improved.

The mandrel 34 is disposed at the forming position of the necks 48c and 48f from the start of the spinning process, and is preferably controlled so as to be separated from the necks 48c and 48f after the processing is completed. May be controlled.

After the necks 48c and 48f are formed as described above, the inlet pipe 40 is inserted or press-fitted into one neck 48f, the burring hole 43a of the first partition 43, and the burring hole 45a of the second partition 45. The outlet pipe 42 is connected to the other neck portion 48c, the burring hole 46a of the third partition 46, the burring hole 45a of the second partition 45,
The silencer as shown in FIG. 4D is formed by inserting or pressing into the burring hole 43a of the first partition 43 and fixing it.

FIG. 5 shows a third embodiment of the present invention. Some mufflers include an inlet pipe and an outlet pipe, such as a sub-muffler, which are formed as a single integrally formed pipe or a single pipe formed by connecting two pipes. FIG. 5 shows an example in which the present invention is applied to such a muffler.

In the step shown in FIG. 5A, first, a small hole 5 is used as a pipe which also serves as an inlet pipe and an outlet pipe.
The stainless steel wool layer 52 is formed by winding stainless wool around a predetermined area of the pipe 50 formed with the pipe 1, and the glass wool layer 53 is formed by winding glass wool around the circumference. Since the glass wool layer 53 alone does not usually maintain its shape, the outer shape of the glass wool layer 53 is held by a fixing means such as a binder so that it can be inserted or pressed into the outer cylinder 48 in the next step. The stainless wool layer 52 is for preventing glass wool wound around the outer periphery of the stainless wool layer 52 from scattering from the small holes 51 into the pipe 50. The outer diameter of the glass wool layer 53 is substantially the same as the inner diameter of an outer cylinder 48 described later,
The front and rear end surfaces 53a and 53b are formed as inclined surfaces along the tapered surface of the outer cylinder 48 formed by spinning described later. This is referred to as an internal structure 54.

Next, the internal structure 54 is replaced with the one shown in FIG.
As shown in (1), insertion or press-fitting is performed from one opening of the outer cylinder 48 having both ends opened. Next, the aforementioned outer cylinder 48 is
2 and the upper and lower clamps 12 and 13 of the clamping device 11 in the spinning machine shown in FIG. 2, and spinning is performed in the same process as in the embodiment shown in FIG. ) To reduce the diameter as shown in FIG.
48b, 48d, 48e and necks 48c, 48f are formed.

The pipe 50 is connected to the axis X of the outer cylinder 48.
₃ and may be arranged coaxially, but in the embodiment of FIG. 5 is inclined to the axis X ₅ of the pipe 50 with the axis X ₃ of the outer tube 48. Neck portion 48c of the case where such a pipe 50 is inclined, forming of 48f, as described in FIG 3 (D), the clamping device 11 is a plane rotated, the outer cylinder 48 side in the roll rotation axis X ₅ It is performed while maintaining the inclined state.

FIG. 6 shows a fourth embodiment of the present invention. In the present embodiment, as in the embodiment shown in FIG. 5, as the inlet pipe and the outlet pipe, a single integrally formed pipe or two pipes are connected to form a single pipe, Further, an example in which the present invention is applied to a muffler using a pipe whose both ends are bent as an internal structure will be described.

First, as shown in FIG.
The taper surfaces 48a, 48b and the neck 48c are formed at one end of the by reducing the diameter by the eccentric and inclined spinning process as described above.

Next, as shown in FIG.
And a pipe 60 in which one bent portion 62 serving as an inlet portion and the other bent portion 63 serving as an outlet portion are bent in opposite directions.
8 and one bent portion 62 is inserted or pressed into the neck portion 48c as shown in FIG. 6 (B).

Next, as shown in FIG. 6C, the other end of the outer cylinder 48 is reduced in diameter by the above-described eccentricity and inclined spinning to form the tapered surfaces 48d and 48e and to bend. The neck portion 48f is formed on the outer surface of the portion 62.

Thus, a resonance type sub-muffler having the resonance chamber 64 is manufactured. Also in the fourth embodiment, a partition wall may be inserted as in the first embodiment, or glass wool may be inserted as in the third embodiment. The internal structure is optional depending on the silencing requirement as a silencer. FIG. 7 shows a fifth embodiment of the present invention. This embodiment shows an example in which the present invention is applied to a muffler using an internal structure in which a branch pipe having an open end is connected to a single pipe that also serves as an inlet pipe and an outlet pipe.

In this embodiment, first, the outer cylinder 48 having both ends opened is reduced in diameter by spinning only at one end side as shown in FIG. 6 (A), and then the branch is bent in advance and the tip is opened. The pipe 70 to which the pipe 71 is connected is inserted from the opening side of the outer cylinder 48 so that one end of the pipe 70 has a reduced diameter neck portion 48.
Then, the other end of the outer cylinder 48 is reduced in diameter by spinning to form a neck 48f on the outer periphery of the other end of the pipe 70. This spinning is based on the eccentric spinning described above.

Thus, a Helmholtz resonator type sub-muffler having the branch pipe 71 as a neck pipe is manufactured. In addition,
In the example of FIG. 7, the central portion 72 of the pipe 70 is inclined, and one bent portion 73 serving as an inlet portion and the other bent portion 74 serving as an outlet portion are made parallel to the axis of the outer cylinder 48. The portions 73 and 74 may be inclined with respect to the axis of the outer cylinder 48 as shown in FIG.

FIG. 8 shows a sixth embodiment of the present invention. In the present embodiment, the present invention is applied to a muffler using an internal structure in which a flexible joint portion that can be easily bent is provided integrally or separately in the middle of one pipe that also serves as an inlet pipe and an outlet pipe. Here is an example.

In this embodiment, as shown in FIG. 8A, a pipe 80 serving as an inlet portion, a pipe 81 serving as an outlet portion, and an intermediate pipe having a small hole 83 formed therebetween. An internal structure 85 is formed by a flexible joint portion 82 formed of a bellows and the like which connects the pipes 80, 82, and 81 with each other.

First, the upper and lower clamps 12,. At 13, the outer cylinder 48 is held and the internal structure 85 is inserted and arranged in the outer cylinder 48. In this embodiment, a clamp device 86 for holding the pipes 80 and 81 is provided separately from the clamp device 11, and the pipe 81 is held by the clamp device 86 as shown in FIG. I do.

Next, on the pipe 80 side, the above-described eccentric spinning processing is performed by the above-described spinning processing machine to reduce the diameter, thereby forming the tapered surfaces 48a and 48b, and connecting the neck portion 48c to the axial center of the outer cylinder 48. Molded with eccentricity. At this time, the pipe 80 receives a force in a direction (eccentric direction) orthogonal to the axis of the outer cylinder 48 by the roller 33, but the two flexible joints 84, 84 bend the pipe 80 to make the outer cylinder 48. Of the outer cylinder 4 while keeping parallel to the axis (revolution axis of the roller 33).
The pipe 80 and the neck 48 are positioned eccentrically with respect to the axis of the shaft 8.
It is easy to arrange and form c.

After the spinning process is completed, the two clamping devices 11 and 86 are released, and the outer cylinder 48 is inverted in the axial direction so that the outer cylinder 48 is vertically clamped as shown in FIG.
The pipe 81 side is subjected to eccentric spinning as described above. At this time, the pipe 80 side is the neck 4
8c, the pipe 80 does not need to be held by the clamp device 86. However, if necessary, the outer surface of the neck 48c may be clamped by the clamp device 86 or the outer end of the pipe 80 may be held from the inside. It may be supported by a mandrel.

FIG. 9 shows a seventh embodiment of the present invention. The present embodiment is an example in which one side of a pipe serving as an inlet pipe and an outlet pipe is arranged in parallel with the axis of the outer cylinder 48 and the other side is inclined with respect to the axis of the outer cylinder 48.

In this embodiment, as shown in FIG. 9A, an internal structure 93 is constituted by a pipe 90 serving as an inlet portion and a pipe 91 serving as an outlet portion, which are formed by a bendable flexible joint portion 92 made of bellows or the like. are doing. Small holes 94 and 95 are formed in the pipes 90 and 91, respectively.

The internal structure 93 is shown in FIG.
Is disposed in the outer cylinder 48 as shown in FIG.
As shown in FIG. 6C, spinning is performed on the pipe 90 side. As shown in FIG.
In the spinning process on the side, a normal spinning process coaxial with the axis of the outer cylinder 48 is performed. During such spinning, a force is applied to each pipe in a direction perpendicular to the axis of the pipe, but the pipe moves following the flexible joint 92, and the pipe is concentric with the necks 48c and 48f. (Accurately, it is concentric with the revolving axis of the roller 33), so that the spinning can be favorably performed.

The flexible joints 84 and 92 shown in FIGS. 8 and 9 are different from the integrally formed bellows as described above.
A separate bellows may be joined by welding or the like, and furthermore, a joint having a mechanical structure such as a ball joint may be used, or a known flexible joint can be used.
However, if the flexible joints 84 and 92 are formed of the bellows as described above, they have not only the degree of freedom of bending but also the absorbing power in the axial direction. It can also serve as a mechanism, which is convenient.
Further, in the embodiment shown in FIGS.
Glass wool may be externally fitted to 0 to 82 and 90 and 91 as in the embodiment shown in FIG.

In each of the above embodiments, one neck (pipe) and the other neck (pipe) are arranged at symmetric positions in the circumferential direction about the axis of the outer cylinder 48, but are arranged at asymmetric positions. When the outer cylinder 48 is turned over,
8 can be rotated (indexed) around the axis by a desired amount.

[0064]

As described above, according to the first aspect of the present invention, the internal structure having the inlet pipe and the outlet pipe is easily inserted or press-fitted into the outer cylinder from the opening thereof. After the arrangement, the opening end of the outer cylinder is reduced in diameter by spinning and the neck is fitted to the inlet pipe and / or the outlet pipe, so that the internal structure can be easily sealed in the outer cylinder. .
In addition, since the outer cylinder, the outer cylinder end plate formed by reducing the diameter, and the neck are formed by a single sheet of a series of three members, the airtightness therebetween is improved, the strength is improved, and the noise is reduced. It is effective as a container. Further, since the outer cylindrical portion to the neck portion can be formed without a joining step, the manufacturing cost can be reduced as compared with the conventional one having the joining step.

Furthermore, the section from the outer cylinder to the neck is tapered by spinning to gradually change the cross section of the muffler, so that the conventional outer cylinder is a wound plate and the end plate is the outer cylinder shaft core. And the bending strength can be improved as compared with a structure in which stress is concentrated on the joint due to a sudden change in cross section. This effect becomes larger as the silencer has a larger sectional area.

Therefore, a silencer most suitable for an exhaust system for an internal combustion engine can be manufactured by spinning. In addition, the inlet
At least one of the pipe and outlet pipe
Eccentric and / or inclined positional relationship with the axis of the outer cylinder
The above-mentioned effect can be exhibited even with the silencer in
It is possible to support various types of silencers. According to the invention as set forth in claim 2, in addition to the above effects, the inlet pipe and the outlet pipe are retrofitted.Therefore, when spinning the open end of the outer cylinder, there is no inlet pipe or outlet pipe, There is no need to consider interference between these pipes and the spinning roller or mandrel, and the degree of freedom in spinning is increased.

According to the third aspect of the present invention, a muffler such as a so-called sub-muffler, in which the inlet pipe and the outlet pipe are formed as a single piece, can be manufactured with the above-mentioned effects. Further, the pipe may be straight or bent, and even in such a pipe, the above effects can be exhibited.

According to the fourth aspect of the present invention, in addition to the above-described effects, the inlet pipe and the outlet pipe are connected via the flexible joint which can be bent. The pipe follows the axial direction of the neck so that the pipe fitted inside the neck is concentric with the neck, and is fitted concentrically in the neck. Therefore, even if the inlet pipe and the outlet pipe are connected and eccentrically fitted to the neck, a straight pipe can be used for the inlet pipe and the outlet pipe, and the pipe is bent in advance. Can be omitted.

Further, when used as a muffler for an internal combustion engine, a difference in the amount of expansion occurs due to a difference in thermal expansion between the inlet pipe and the outlet pipe and the outer cylinder. The difference in the amount of expansion can be absorbed by the flexible joint. This has the effect that the mechanism for absorbing the expansion can be omitted.

[0070] According to the invention of 請 Motomeko 5 and 6, by gradually changing the cross section of the silencer is formed in a tapered shape by spinning from the outer cylindrical portion to the neck, the outer cylinder, such as the conventional The bending strength can be improved as compared with a winding plate in which the end plate is disposed orthogonal to the outer cylinder axis and stress is concentrated on the joint due to a sudden change in cross section. According to the invention of claim 7 , the inlet pipe and / or
Or, since the outlet pipe is retrofitted, there is no inlet pipe or outlet pipe when spinning the open end of the outer cylinder, so there is no need to consider interference between these pipes and the spinning roller or mandrel, and the spinning processing The degree of freedom is increased.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing an embodiment of a spinning machine used in the manufacturing method of the present invention.

FIG. 2 is a plan view of FIG. 1;

3 (A) to 3 (D) are process diagrams showing a first embodiment of the manufacturing method of the present invention, wherein (a) of each process is a plan sectional view, and (b)
Is a side view.

4A to 4D are process diagrams showing a second embodiment of the manufacturing method of the present invention, wherein (a) of each process is a plan sectional view, and (b)
Is a side view.

FIGS. 5A to 5C are process diagrams showing a third embodiment of the manufacturing method of the present invention, wherein FIG. 5A is a plan sectional view, and FIG.
Is a side view.

6 (A) to 6 (C) are process diagrams showing a fourth embodiment of the manufacturing method of the present invention, and show respective plan sectional views.

FIG. 7 is a plan sectional view showing a fifth embodiment of the manufacturing method of the present invention.

8 (A) to 8 (C) are process drawings showing a sixth embodiment of the manufacturing method of the present invention, and show respective plan sectional views.

9 (A) to 9 (C) are process drawings showing a seventh embodiment of the manufacturing method of the present invention, each showing a plan sectional view.

FIG. 10 is a plan sectional view of a silencer according to a conventional manufacturing method.

FIG. 11 is a longitudinal sectional view of a silencer according to another conventional manufacturing method.

[Explanation of symbols]

33 ... Spinning roller 40 ... Inlet pipe 42 ... Outlet pipe 47 ... Internal structure 48 ... Outer cylinder 48c, 48f ...
Neck 84,92 ... Flexible joint

Continued on the front page. (51) Int.Cl. ⁷ Identification code FI F01N 1/24 F01N 1/24 F 7/08 7/08 F (72) Inventor Masashi Ota Miyoshi-cho, Nishikamo-gun, Aichi Prefecture No. 35 35 Sanwa Hachidayama Plant Co., Ltd. (72) Inventor Shigeki Wakamatsu Miyoshi Town Nishikamo-gun Aichi Prefecture Miyoshi Town Hachiwada 5th 35 Sango Hachidayama Plant Co.Examiner Masahiro Sato (56) References JP-A-10-280953 (JP, A) JP-A-8-42336 (JP, A) JP-A-57-206538 (JP, A) JP-A-6-336917 (JP, A) −123612 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F01N 7/18 F01N 1/02 F01N 1/08 F01N 1/10 F01N 1/24 F01N 7/08

Claims (7)

(57) [Claims] [Claim 1] have a inlet pipe and outlet pipe, of the inlet pipe and the outlet pipe small
At least one shaft center and the shaft center of the outer cylinder
Other internal structures Ru positional relationship near inclined, inserted or pressed into the opened outer cylinder, eccentric to the open end of the outer tube Supini
Characterized in that a neck portion is formed at the tip of the reduced diameter portion by performing a cutting process and / or an inclined spinning process, and the neck portion is fitted to an outer periphery of an inlet pipe and / or an outlet pipe. . 2. An inner structure is inserted or press-fitted into an opened outer cylinder, and the open end of the outer cylinder is subjected to eccentric spinning processing.
And / or inclined spinning to reduce the diameter to form a neck at the tip of the reduced diameter portion, and then connect an inlet pipe and an outlet pipe to the neck and at least one of the shaft cores.
And the axis of the outer cylinder are eccentric and / or inclined.
A method for manufacturing a silencer, wherein the silencer is internally fitted and fixed to the internal structure. 3. The method for manufacturing a muffler according to claim 1, wherein the inlet pipe and the outlet pipe are formed integrally. 4. An inlet pipe and an outlet pipe which are integrally connected via a bendable flexible joint,
Inserted into the opened outer cylinder, eccentric to the open end of the outer tube Supini
By reducing the diameter of the inlet pipe and / or the outlet pipe by reducing the diameter of the inlet pipe and / or the outlet pipe by reducing the diameter of the inlet pipe and / or the outlet pipe.
At least one shaft center and the shaft center of the outer cylinder are eccentric and / or
Is a method for manufacturing a silencer, characterized by being placed in an inclined positional relationship . 5. An outer cylinder, wherein at least one of an inlet pipe and an outlet pipe is arranged in an outer cylinder such that its axis and the axis of the outer cylinder are eccentric and / or inclined. Eccentric spinning
And forming a neck at the tip of the reduced diameter portion by a spinning process and / or inclined spinning, and fitting the neck to an outer periphery of an inlet pipe and / or an outlet pipe. 6. Inserting at least one of an inlet pipe and an outlet pipe into an open outer cylinder, and reducing the diameter of the open end of the outer cylinder by eccentric spinning and / or inclined spinning. the neck portion is formed in said reduced diameter portion distal Te, by fitting the該首portion on the outer periphery of the inlet pipe and / or outlet pipe, the inlet pipe and a
At least one shaft center of the outlet pipe and the shaft center of the outer cylinder
Are eccentric and / or inclined
A method for manufacturing a muffler, characterized in that: 7. An eccentric spinning process for the open end of the outer cylinder .
And / or slant spinning to reduce the diameter to form a neck at the tip of the reduced diameter portion, and then fit an inlet pipe and / or outlet pipe inside the neck and fix it
And reduce the number of inlet pipes and outlet pipes
And one shaft center and the shaft center of the outer cylinder are eccentric and / or
A method for manufacturing a muffler, characterized in that the muffler is placed in an inclined positional relationship .