JPH1061424A - Noise eliminator and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily and certainly airtightly fix an approximately U-shaped communicating pipe to an end plate when both end parts of the approximately U-shaped communicating pipe is fixed by being penetrated into a penetrating hole formed in a plate member, by tightly sticking both end parts positioned in a penetrating hole part to the penetrating hole, and arranging in both end parts, enlarged parts locked to the plate member. SOLUTION: An inlet pipe 12, inner pipes 13, 14 and an outlet pipe 15, which are fixed to partitioning plates 9, 10, are arranged in a noise eliminator main body 12. Then, one end part 16a of a U-shaped communicating pipe 16, which is penetrated and fixed to an end plate 3, is connected to the outlet pipe 15, and the other end part 16b thereof is opened in a terminal side chamber 5. In the case that this communicating pipe 16 is fixed to the end plate 3 and the outlet pipe 15, holes formed in the end plate 3 are burred, and form flanges 3a, 3b are bent, and both end parts 16a, 16b of the U-shaped communicating pipe 16 are inserted to the holes, and after that, a pipe enlarging punch die is pressure-fitted to both end parts 16a, 16b so as to enlarge the diameter of both end parts 16a, 16b, and both end parts 16a, 16b can be fixed by being pressingly attached to the flanges 3a, 3b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a muffler and a method of manufacturing the same, and more particularly to a muffler in which a substantially U-shaped communicating pipe is inserted into and fixed to a plate of the muffler.

[0002]

2. Description of the Related Art Conventionally, in a silencer of an internal combustion engine, FIG.
As shown in FIG. 3, a plurality of partition plates 101
The chambers 102 to 105 are communicated by inner pipes 106 and 107, and an inlet pipe 108 and an outlet pipe 109 are provided.
Both ends 112 and 113 of the U-shaped communication passage 111 are provided on the end plate 110.
A structure in which the outlet pipe is substantially elongated to attenuate high-frequency components of the exhaust pipe is disclosed in, for example, Japanese Utility Model Publication No. 5-43215.

[0003] The fixing of both ends 112 and 113 of the U-shaped communication passage 111 to the end plate 110 is generally performed by arc welding W in order to secure the airtightness and joining strength of the fixing portion. .

[0004]

As described above, U
The two end portions 112 and 113 of the letter-shaped communication pipe 111 are
With both ends 112 and 113 inserted into the end plate 11
In the fixing method of arc welding to 0, when one end 112 of the U-shaped communication pipe 111 is welded all around the circumference, the welding torch 114 interferes with the other end 113 as shown in FIG. Cannot perform full circumference welding. For this reason, there is a problem that intermittent welding is performed, it is difficult to secure welding quality, workability is deteriorated, and work time and manufacturing cost are increased.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a muffler that can easily and reliably fix the above substantially U-shaped communication pipe to an end plate, and a method of manufacturing the same.

[0006]

In order to solve the above-mentioned problems, the invention according to the first aspect is characterized in that both ends of a substantially U-shaped communication pipe are inserted into and fixed to insertion holes formed in a plate material. In this case, both ends (16a) and (16b) located at the insertion holes (3c) and (3d) are in close contact with the insertion holes (3c) and (3d), and the both ends (16a) and (16b) A silencer characterized by having enlarged diameter portions (16f) and (24) to be locked to a plate material (3).

According to a second aspect of the present invention, at least one end (16a) of the substantially U-shaped communication pipe (16) according to the first aspect is airtightly fitted to another communication pipe (15). A silencer characterized by being mounted.

According to a third aspect of the present invention, both ends (16a) and (16b) of the substantially U-shaped communication pipe (16) are inserted into the insertion holes (3c) and (3d) formed in the plate (3) to be connected. After having been inserted into the sheet material, the end portions (16a) and (16b) are expanded in diameter and are fixed to the plate (3) by plastic deformation thereof.

According to a fourth aspect of the present invention, both ends (16a) and (16b) of the substantially U-shaped communication pipe (16) are inserted into the through-holes (3c) and (3d) formed in the plate (3) to be connected. After press-fitting, both ends (16a) (16b) of the press-fitted side
The method of manufacturing a muffler, characterized in that the diameter is increased and the enlarged diameter portions (16f) (24) are locked to the plate (3).

According to a fifth aspect of the present invention, in the third or fourth aspect of the present invention, after the diameters of both end portions (16a) and (16b) are increased, the substantially U-shaped communication pipe (16) is fixed. A method of manufacturing a silencer, comprising fixing a plate (3) to an outer shell (2) of the silencer.

According to a sixth aspect of the present invention, in the fifth aspect of the present invention, the plate material (3) to which the substantially U-shaped communication pipe (16) is fixed is fixed to the outer shell (2) of the muffler. In this case, at least one end (16a) of the substantially U-shaped communication pipe (16) is airtightly fitted to another communication pipe (15).

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described based on an embodiment shown in the drawings. First, a first embodiment shown in FIGS. 1 to 4 will be described.

In FIG. 1, reference numeral 1 denotes a silencer main body, an outer shell 2 formed in an elliptical or cylindrical outer shape, and the outer shell 2 formed therein.
End plates 3 and 4 fixedly closed at both ends of the outer shell 2, partition plates 9 to 11 for dividing the inside of the outer shell 2 into a plurality of chambers 5 to 8, an inlet pipe 12 and an inner pipe fixed to the partition plate 9. 13 and an inner pipe 14 fixed to the partition plate 10
And one end 16a is connected to the outlet pipe 15 and is fixed to the outlet pipe 15 through the end plate 3.
The other end 16b is in open communication with the starting end chamber 5, and U
And a U-shaped communication tube 16 having the end portion 12c exposed to the outside of the end plate 3.

Next, a method of fixing the U-shaped communication pipe 16 to the end plate 3 and the outlet pipe 15 will be described with reference to FIG.
This will be described with reference to FIGS. First, as shown in FIG. 2, two holes are formed in the end plate 3 before being attached to the outer shell 2 at a position where the U-shaped communication pipe 16 is inserted, and the holes are formed by burring. Then, the flanges 3a and 3b are bent toward the outside of the end plate 3 to form the flanges 3a and 3b.
By b, the insertion holes 3c and 3d slightly larger in diameter than the outer diameter of the base tube of the U-shaped communication tube 16 are formed. The flange 3
a and 3b may be bent toward the inside of the end plate 3.

Next, the U-shaped communication pipe 16 is bent into a U-shape and both ends 16a and 16b are not expanded as shown by the solid lines in FIG.
The two end portions 16a and 16b of the end plate 3 are inserted into the through holes 3c and 3d of the end plate 3 from the outer side of the end plate (left side in FIG. 2).
Insert as shown.

Next, from the open ends of the ends 16a and 16b, the expanding pipe punches 17 and 18 are pressed into the ends 16a and 16b along their axes. The two expanding pipe punch dies 17 and 18 are press-fitted simultaneously or with a time difference by a suitable pressurizing means (not shown).

The expanding pipe punches 17 and 18 have a guide surface 1 having an outer diameter smaller than the inner diameter of the U-shaped communicating pipe 16.
7a, 18a, first tapered surfaces 17b, 18b continuously expanding at the rear portions of the guide surfaces 17a, 18a, and the U-shaped communication pipe continuously at the rear portions of the first tapered surfaces 17b, 18b. A flange 3a formed by forming 16 base tubes on the end plate 3,
The first enlarged surfaces 17c, 18c which can be pushed and expanded so as to be pressed against the inner surface of 3b, and the first enlarged surfaces 17c, 18
c, the second tapered surfaces 17d, 18 continuously increasing in diameter at the rear part
d and a second enlarged surface 1 having a diameter larger than that of the first enlarged surfaces 17c and 18c continuously to the rear portions of the second tapered surfaces 17d and 18d.
7e and 18e. Note that the second enlarged surface 17e,
The outer diameter of 18e is set so as to increase the diameter of the base tube of the U-shaped communication pipe 16 to a diameter that can be press-fit into the inner surface of the outlet pipe 15.

Accordingly, the above-mentioned double-expansion punch dies 17, 1
By press-fitting 8 into both ends 16a, 16b of the U-shaped communication pipe 16, both ends 16a, 16b are expanded in diameter as shown in FIG. That is, the expanding pipe punch 17,
A portion of the U-shaped communication pipe 16 is enlarged in diameter by the first enlarged diameter surfaces 17c, 18c of 18 and is crimped to the flanges 3a, 3b of the end plate 3, and the outer surface of the crimped portion 16d and the flanges 3a, 3c.
b, an inner surface of the taper portion 16e is formed by the second taper surfaces 17d, 18d, and the outer surface of the tapered portion 16e is pressed against the rear surfaces of the flanges 3a, 3b. 20 are formed.

Therefore, the sealing surfaces 19 and 20 ensure sufficient airtightness between the end plate 3 and the U-shaped communication tube 16 and at the same time press the U-shaped communication tube 16 against the end plate 3. Is maintained. Further, the second enlarged surfaces 17e and 18e form an enlarged portion 16f having a diameter larger than that of the crimping portion 16,
The enlarged diameter portion 16f, more specifically, the tapered portion 16e surely prevents the U-shaped communication pipe 16 from coming off.

Next, the end plate 3 to which the U-shaped communication pipe 16 is fixed as described above is previously attached to the above-mentioned partition plates 9 to 11, the inlet pipe 12, the inner pipes 13, 14, the outlet pipe 15, and the other. At the end of the outer shell 2 to which the end plate 4 is assembled and fixed, a fitting portion 3 formed at the outer periphery of the end plate 3
Press-fit with e.

At the time of fitting, the enlarged diameter portion 16f at one end 16a of the U-shaped communication pipe 16 is connected to the outlet pipe 1.
5 is press-fitted. Next, the peripheral portion 3f of the end plate 3 and the outer shell 2
To the peripheral portion 2a.

By press-fitting the enlarged diameter portion 16f into the outlet pipe 15 as described above, the U-shaped communication pipe 16 is prevented from moving inward of the end plate 3. Therefore, the U-shaped communication tube 16 is positioned in the tube axis direction by the sandwiching of the press contact portion 21 and the sealing surfaces 19 and 20, and the position is firmly held.

Next, a second embodiment shown in FIGS. 5 to 8 will be described. First, the end plate 3 before being assembled to the outer shell 2 is positioned at a portion where the U-shaped communication pipe 16 is inserted.
Each hole is formed and the holes are burred to form the flanges 3g and 3h bent toward the inside of the end plate 3. The flanges 3g and 3h allow the U-shaped communication pipe 16 to be formed.
Are formed into the insertion holes 3c and 3d into which the base tubes are press-fitted (tightly fitted). The flanges 3g and 3h may be bent toward the outside of the end plate 3.

Next, the U-shaped communication pipe 16 is bent in advance into a U-shape and both ends 16a and 16b are not expanded as shown by solid lines in FIG.
5 are press-fitted into both insertion holes 3c and 3d of the end plate 3 as shown in FIG. By this press-fitting, the outer peripheral surfaces of both ends 16a and 16b and the inner peripheral surfaces of the flanges 3g and 3h are pressed against each other, and the pressed surface becomes the sealing surface 23.

Next, at both ends 16a and 16b press-fitted into the end plate 3 as described above,
The enlarged diameter portion 24 is formed as shown by a chain line in FIG. A processing jig for forming the enlarged diameter portion 24 will be described with reference to FIG.

A plurality of processing jigs 25, for example, four
Molding die 26 divided into up to six pieces, and tapered surface 26 formed on the inner surface of molding die 26 so as to reduce the diameter at the rear.
a, and a forming protrusion 26 b protruding from the outer peripheral surface of the forming die 26.
And a holder 27 for holding each mold 26 slidably in a radial direction perpendicular to the axis XX, and a shaft penetrating the holder 27 in the axis XX direction at the axis portion. 28
And a taper pin 29 fixedly provided at the tip of the shaft 28 and having an outer peripheral surface formed on a conical tapered surface 29a along the tapered surface 26a. The shaft 28 is moved to the axis X by appropriate driving means (not shown).
It is designed to move forward and backward in the -X direction. Note that the processing jig 25 has an adjustment mechanism that can be inserted at any position with respect to the end plate 3.

The enlarged diameter portion 24 is processed by the processing jig 25.
The method for fixing the U-shaped communication tube 16 to the end plate 3 by forming the end plate 3 will be described. First, as shown in FIG. 8, in a state where the taper pins 29 are advanced and the diameters of the molding dies 26 are reduced by a return spring or the like (not shown), the U-shaped communication in a state of being pressed into the end plate 3 as described above. End 1 of tube 16
The processing jig 25 is inserted to the position shown in FIG.
This insertion position is set so that the molding convex portion 26b does not interfere with the sealing surface 23 formed by the flange 3g of the end plate 3 and is close to the inner end of the flange 3g.

Next, the shaft 28 is pulled to the right in FIG. 8 by driving means (not shown), and the taper pins 29 are drawn into the respective molds 26. Thereby, each mold 26
Are guided outward by a holding tool 27 and are pushed outward in a radial direction as shown by a chain line, and are formed on each of the molds 26.
By b, a part of the end 16a of the U-shaped communication pipe 16 is expanded as shown in FIG. This expanded diameter portion 24 further prevents the U-shaped communication pipe 16 from coming off the end plate 3.

After the above processing is completed, the taper pin 29
8 to reduce the diameter of each forming die 26 and remove the processing jig 25 from the end 16a. still,
The other end 16b of the U-shaped communication pipe 16 is similarly processed using the same processing jig 25 as described above to form the enlarged diameter portion 24a.

Next, the end plate 3 assembled as described above is
It is assembled to the outer shell 2 as in the first embodiment, and one end 16a is connected to the outlet pipe 1 as in the first embodiment.
5 and press-fit.

Therefore, the U-shaped communicating pipe 16 is positioned in the axial direction by the sandwiching of the press contact portion 30 and the sealing surface 23, and the position is firmly held. FIG. 9 shows a third embodiment of the present invention, in which two enlarged diameter portions 24 in the second embodiment are provided inside and outside the end plate 3. That is, the molding die 26 in the second embodiment described above.
As shown in FIG. 9, two molding protrusions 26 b are arranged inside and outside of the end plate 3, and the molding plate 26 is pushed out by pulling in the taper pin 29 as in the second embodiment. The communication pipe 16 is located inside and outside the flange 3g in FIG.
The enlarged diameter portions 24, 24 are formed.
According to the third embodiment, the airtightness and the adhesion between the end plate 3 and the communication pipe 16 are further improved.

In the second embodiment, the pipe diameters of the ends 16a and 16b fixed to the end plate 3 before the diameter expansion processing are set to U
The pipe diameter of the end portions 16a and 16b was previously set to U, as shown in the fourth embodiment of FIG.
The diameter of the end portion 3c is smaller than the diameter of the tube-like portion 16c, and the insertion holes 3c, 3d of the end plate 3 are also reduced in diameter to the end portions 16a, 16b
The diameter may be small for press-fitting. Then, the end portions 16a, 1
6b is press-fitted into the end plate 3 to process the enlarged diameter portion 24 in the same manner as described above. According to this embodiment, the inner and outer ends of the flanges 3g and 3h of the end plate 3 are clamped by the large-diameter portions by the formation of the enlarged-diameter portions 24 as described above, and the sealing performance and the position holding are further improved.

Further, as in the fifth embodiment shown in FIG.
The diameters of the end portions 16a and 16b are previously increased from the diameter of the U-shaped portion 16c, and the insertion holes 3c and 3d of the end plate 3 are also increased in diameter so that the enlarged end portions 16a and 16b are press-fitted. Is also good. Then, the end portions 16a and 16b are press-fitted into the end plate 3, and the enlarged diameter portion 24 is processed in the same manner as described above. In this embodiment, the same operation and effect as those of the first embodiment can be exhibited.

The communication pipe 16 in the embodiment shown in FIG.
The communication pipe 16 may be substantially U-shaped, U-shaped, or a circular end-shaped shape with both ends extending in parallel. Therefore, the present invention includes communication pipes having these shapes, and these are collectively referred to as substantially U-shaped.

In each of the above embodiments, the case where the substantially U-shaped communication pipe 16 is fixed to the end plate 3 has been described.
The present invention can also be applied to a case where the communication pipe 16 having a character shape is fixed to any of the partition plates 9 to 11 in the outer shell 2 and is built in the outer shell 2.

Although the manufacturing method of the present invention is particularly effective when the substantially U-shaped communicating pipe 16 is connected to the end plate 3 as in the above-described embodiment, the manufacturing method of the present invention is not limited to FIG. When the exhaust inlet pipe 40 is fixed to the end plate 3 and the downstream portion of the exhaust inlet pipe 40 is press-fitted and fixed to the inlet pipe 41, or the exhaust outlet pipe 42 is fixed to the end plate 4 and the exhaust outlet is fixed. Connect the outlet pipe 4 to the upstream part of the pipe 42.
The present invention can also be applied to the case where it is press-fitted and fixed to 3. That is, the inlet pipe and the outlet pipe can be fixed by plastic deformation as in the above embodiments without welding and fixing.

[0037]

As described above, according to the present invention, the substantially U-shaped communication pipe is fixed by expanding the diameter of the pipe without welding and fixing it to a plate material such as an end plate or a partition plate constituting the muffler. The conventional problems caused by welding can be solved.

[0038] According to the second aspect of the present invention, at least one end of the substantially U-shaped communication pipe is airtightly fitted to another communication pipe, so that the U-shaped communication pipe is further improved. When assembling the plate member to which the U-shaped communication pipe is fixed to the outer shell, at least one of the U-shaped communication pipes is hermetically sealed to another communication pipe. If it fits, the time and cost for assembling the silencer can be reduced.

Further, a substantially U-shaped communicating pipe is fixed to the plate material in advance, and then the plate material is fixed to the outer shell. Can be easily performed as compared with the case where the work is fixed to the plate material after being assembled to the outer shell.

[Brief description of the drawings]

FIG. 1 is a side sectional view of a muffler showing a first embodiment of the present invention.

FIG. 2 is a view for explaining a diameter expanding step using a diameter expanding punch mold in the embodiment of FIG. 1;

FIG. 3 is a diagram in which a substantially U-shaped communication pipe is fixed to a plate using the diameter-enlarged punch shown in FIG. 2;

FIG. 4 is an enlarged cross-sectional view showing a diameter-expanded state in FIG. 3;

FIG. 5 shows a second embodiment of the present invention, and is a cross-sectional view in which a substantially U-shaped communication pipe is inserted into an end plate.

FIG. 6 is a cross-sectional view in which the diameter of a substantially U-shaped communication pipe is increased from the state of FIG. 5;

FIG. 7 is an enlarged cross-sectional view showing the expanded state in FIG. 6;

FIG. 8 is a sectional view showing a processing jig used in a second embodiment of the present invention.

FIG. 9 is a sectional view of a main part showing a third embodiment of the present invention.

FIG. 10 is a sectional view showing a fourth embodiment in an expanded state.

FIG. 11 is a sectional view showing a fifth embodiment in an expanded state.

FIG. 12 is a diagram in which an inlet pipe and an outlet pipe are fixed to a plate using the manufacturing method of the present invention.

FIG. 13 is a sectional view showing a conventional example.

[Explanation of symbols]

2 ... outer shell 3 ... plate material 3c, 3d ... insertion hole 15 ... communication tube 16 ... substantially U-shaped communication tube 16a, 16b ... end 16f, 24 ... enlarged diameter portion

Claims (6)

[Claims] 1. A device in which both ends of a substantially U-shaped communication pipe are inserted into and fixed to an insertion hole formed in a plate material, wherein both ends located in the insertion hole are in close contact with the insertion hole, and both ends are fixed. A silencer characterized in that the portion has an enlarged diameter portion which is locked to the plate material. 2. The muffler according to claim 1, wherein at least one end of the substantially U-shaped communication pipe is air-tightly fitted to another communication pipe. 3. After inserting both ends of a substantially U-shaped communication pipe into insertion holes formed in a plate material to be connected, the both ends are enlarged in diameter and fixed to the plate material by plastic deformation. A method for manufacturing a silencer, comprising: 4. After press-fitting both ends of a substantially U-shaped communication pipe into insertion holes formed in a plate material to be connected, the both ends on the press-fitted side are enlarged in diameter, and the enlarged diameter portion is formed. A method for manufacturing a silencer, wherein the silencer is locked to a plate. 5. The muffler according to claim 3, wherein the plate material to which the substantially U-shaped communication pipe is fixed is fixed to the outer shell of the muffler after the diameter of both ends is increased. Manufacturing method of silencer. 6. When fixing a plate material to which a substantially U-shaped communication pipe is fixed to an outer shell of a muffler, at least one end of the substantially U-shaped communication pipe is airtightly connected to another communication pipe. The method for manufacturing a muffler according to claim 5, wherein the muffler is fitted.