CN1004644B - Muffler apparatus and method for making same - Google Patents

Abstract

The present invention aims to provide a muffler device and a making method thereof. The muffler device comprises an inlet pipe and an outlet pipe, wherein a plurality of sound isolation plates extend to a casing from the inlet pipe and the outlet pipe. A position adjacent to the inlet end of the outlet pipe is provided with a pipe diameter contraction part which is composed of wrinkles and convex petals, and the end part of the pipe diameter contraction part is provided with a bell mouth. The pipe diameter contraction increases the area proportion of the muffler casing to the outlet pipe so as to generate the favorable attenuation performance. Since the formation of the outlet pipe and the pressing of the sound isolation plates on the outlet pipe are completed in one procedure, the making method of the muffler is more convenient than the existing method.

Description

Muffler and manufacture method

The present invention is relevant to make the structure of the tubular element that sound suppressor tool parts use, and this sound suppression device is just like silencing apparatus and exhaust nozzle etc.The invention still further relates to the manufacturing of this tubular element.

Use the silencing apparatus of various different sound inhibition or attenuation part or element, have many types well known.Yet slight change on the structural type of element will make same frequency produce different interference forms with sound waves of different frequencies.Therefore,, or use the manufacture method cheaper, can bring preferably or the approaching sound inhibition effect that equates, so this skill also develops in continuation than the past owing to employing and some different total forming shape of past.The present invention is exactly in this sense, obtains the status in this skill field.About this point, just review the evolution of development in the discussion hereinafter, so as to meaning of the present invention is described.

A kind of the have straight relative supplying tube of Jing and the silencing apparatus of output tube have been introduced in (Rowley) (U. S. Patent the 3rd, 672, No. 464) in sieve in shell.Between two pipe fittings and shell, there are some insulation boards to stretch.When upstream seeing from the downstream, output tube has one cylindrically to be shrunk to a trunnion gradually, outwards enlarges rapidly then, returns to approximately original cylindrical size.

The variation that this designing institute is done has been introduced in outer promise (Wagner) (U. S. Patent the 4th, 267, No. 899), and it is opposed that supplying tube and output tube have been made inclined to one side side mutually.Wagner is at U. S. Patent the 4th, 368, done further variation again in No. 799, all added the trunnion part on supplying tube and output tube.In addition, above in each that introduce patent, all be with a cylindrical tube on partly at the constriction of output and supplying tube and trunnion.Like this, obviously in manufacture process, need a forming process, and have one a pipe fitting is pressed into the operation of another pipe fitting, and an operation that press-fits insulation board, the per pass operation all will increase a manufacture cost certainly.

Si Kemeikeer (the Schmeichel) (application case the 505th that apply for June 16 nineteen eighty-three, No. 424, identical with aforementioned patent, delegate and same assignee) muffler that discloses, also, the part and a trunnion part of dwindling are arranged on output tube with straight relative supplying tube and the output tube of Jing.But Schmeichel finds, make output tube dwindle part and trunnion part the time, it is favourable increasing some bypass passageways of not dwindling.Suppress effect though this output tube has been obtained the favourable sound, need to make the pipe fitting that special shape is arranged.When on silencing apparatus, using, again insulation board is fitted on the pipe fitting.

The sound that the present invention can obtain present skill level suppresses effect, but its to obtain be to utilize to make simple apparatus, thereby reduced cost.

The objective of the invention is to propose a kind of muffler, include a housing, this housing has the wall of a closed curve shape, and two relative end is sealed by the end insulation board; An expansion chamber that between middle insulation board, forms by housing; One is passed and is fixed on inlet tube on an end insulation board and the adjacent middle insulation board and one and passes and be fixed on outer pipe on another end insulation board and the adjacent middle insulation board, this muffler have one from inlet tube through the fluid flow path of expansion chamber to outer pipe, the outer pipe that it is characterized in that this muffler has a undergauge that is formed by the fold that leads to outer frayed end partly, eliminates the noise or the effect of the decay sound thereby back pressure is reduced and the volume of expansion chamber is enlarged to strengthen.

Outer pipe also has a porose part, can arrange along the part that fold is arranged of pipe.In addition, the insulation board that extends between outer pipe and housing can be placed on the part of fold.

A kind of have a silencing apparatus of structural type pipe fitting as described, particularly structural type is in the inlet near outer pipe, have the unexpected sound to suppress effect, have with the skill present situation of being narrated in complicated a lot of pipe fitting near identical and even better sound rejection.The entrance point of having noticed flanging has the effect that reduces back pressure.And, there is the part of fold not only to form a trunnion that the venturi tube effect is arranged, and can keeps outer pipe that constant circumference is arranged after having done like this, thereby after forming fold part and larynx neck, the actual volume of the expansion chamber around must enlarging.So these characteristics are compiled the inhibitory action that has just improved the sound.

What identical significance was arranged is, described favourable shape can obtain by one procedure, and this operation combines the process of the one or more insulation boards of assembling on pipe fitting.Therefore, owing to reduce the inevitable corresponding considerable expense of having saved of assembling procedure.Therefore, the many advantages in the skill present situation can obtain by foolproof structural type, and this structural type is easy to make, and just produced cheap but the utensil of equal effective sound rejection is arranged.

Above-mentioned advantage of the present invention and other target will be further explained hereinafter.With reference to accompanying drawing and the briefing material that this specification proposes, can more understand the present invention.Accompanying drawing is represented the desirable embodiment of device and manufacture method, hereinafter will be with regard to the creativeness of accompanying drawing detailed explanation Apparatus and method for.

Fig. 1 represents a kind of muffler assembly of the proposition according to the present invention, and comprises that its device, figure are the front view that has partial cutaway.

Fig. 2 represents along the cross section of 2-2 line among Fig. 1.

Fig. 3 A-3D is the view similar to Fig. 2, and expression is by the different shape of the pipe fitting that fold is arranged of the present invention's proposition.

Fig. 4 has an offset for the elevation cross-sectional view of noise elimination device between supplying tube and output tube, the structure that the with good grounds the present invention of offset proposes.

Fig. 5 represents along the cross-sectional view of 5-5 line among Fig. 4.

Fig. 6 represents along the cross-sectional view of 6-6 line among Fig. 4.

Fig. 7 represents another embodiment, the partial cross-section that the part silencing apparatus similar to Fig. 1 looked in exhibition.

Fig. 8 is the cross-sectional view along 8-8 line among Fig. 7.

Fig. 9 makes the used one type representative instrument perspective view of silencing apparatus apparatus that the present invention proposes.

Figure 10 illustrates instrument among Fig. 9 and makes apparatus with pressure and combine the side-looking figure before the pipe fitting that compacting the present invention proposes.

Figure 11 is a figure similar to FIG. 10, do not exist together for pressure make that apparatus is actuated to suppress pipe fitting and on pipe fitting fixing insulation board, dashed graph represents that pipe fitting and insulation board leave the situation of pressing behind the instrument of making.

Now explain: in all these figure, identical or corresponding parts are used the identical number of marking on a map expression,,, generally represent with label 20 by the reducing pipe device that the present invention proposes specifically in Fig. 1 with regard to accompanying drawing.Silencing apparatus 22 used reducing pipes 20 are outer pipes among Fig. 1.Silencing apparatus 22 has inlet tube 24 directly right with pipe 20.Inlet tube and outer pipe 24,20 are fixed on the housing 26, have some insulation boards generally to represent with label 28.

As illustrated in fig. 1 and 2, pipe 20 has a undergauge section or diameter shrinkage part 30, is formed by the fold 32 and 34 that tilts.Pipe 20 has turned welt 36 outside at entrance point, links to each other with larynx neck 38 places of diameter shrinkage part 30.

To the right, pipe 20 has an outlet end 40 from the left side of Fig. 1.Pipe 20 has a cylindrical part 46 between outlet end 40 and diameter shrinkage part 30.A pair of mutual spaced insulation board 42 and 44 are arranged, be fixed on traditional mode on the cylindrical part 46 of pipe 20.Cylindrical part 46 has part with holes 48 between insulation board 42 and 44, form the last expansion chamber 43 that lowers sound equipment.

Diameter shrinkage part 30 can also have the meshed portion 50 shown in the figure.The retraction of diameter shrinkage part 30 is in larynx neck 38 places at most, and here the port 36 that turns up with pipe 20 is connected, and also enlarges size from here on, forms the outer frayed end 36 of pipe 20.Can see that as shown in Figure 2 the convex plug 52 and 54 of diameter shrinkage part 30 can some reach the outside of pipe 20 original cylindrical cross-sections.But between the entrance point and outlet end 36 and 40 of pipe 20, on any concrete position, the circumference of pipe 20 is constant all.

Inlet tube 24 has the wall 56 of an entity at its outlet end 58 places.Inlet tube 24 has a part with holes 60 at its close wall 56 places.Inlet tube 24 also has a porose part 62 in addition between insulation board 64 and 66.Insulation board 64 and 66 stretches between pipe 24 and housing 26.

In the running, the waste gas of discharge enters silencing apparatus 22 from inlet tube 24 entrance points 68.Waste gas may expand, by meshed portion 62, enter insulation board 64 and 66 and housing 26 between first damping chamber 65 in go.When exhaust when inlet tube 24 moves on, the back of expanding enters main expansion chamber 23 by meshed portion 60.Wall 56 prevents that waste gas from directly entering outer pipe 20 from inlet tube 24.Waste gas advances to outer pipe 20 from main expansion chamber 23, and may enter from outer turned welt end 36 or meshed portion 50.Outer turned welt can be accepted relatively large waste gas than with additive method, thereby helps to reduce back pressure.The larynx neck plays venturi tube and quickens flowing of waste gas, thereby waste gas is passed through meshed portion 50 suction outlet pipes 20.A final damping chamber 43 is arranged between insulation board 42,44 and housing 26, waste gas can entered before the outlet end 40, the back of expanding enters damping chamber 43 from meshed portion 48.

Main noise elimination in the muffler design or sound attenuation factor are the ratios of suppressor case cross sectional area and pipe fitting section area.The typical area ratio of load-carrying vehicle silencing apparatus is four to one, from 10 inches and five inches calculating of outer pipe diameter of diameter of the housing.Outer pipe of the present invention shape on a large portion of length has increased the ratio of its periphery to area, but also has strengthened the area ratio of housing to outer pipe through transforming.For reducing the outer pipe effective cross-sectional area and improving fold (seeing Fig. 3 A), 8 fonts (seeing Fig. 3 B), cloverleaf (seeing Fig. 3 C) and the pintongs shape (seeing Fig. 3 D) that basic shape that described ratio uses comprises a side.

Improved pipe fitting can also make the volume of main expansion chamber enlarge, and this is an advantage from giving birth to, and is significant characteristics to the decay of the sound in the end.Reducing the another one benefit of the useful area of outer pipe, is the boundary frequency that has improved silencing apparatus, is inversely proportional to because boundary frequency is a effective diameter with pipe fitting.Therefore, the effective frequency range that works of silencing apparatus has obtained increase.And, because improved pipe fitting has larynx neck and increasing section gradually, just can improve the flow velocity of exhaust, there is the entrance of outer turned welt can offset back pressure.So, through the transformed pipe fitting 20 of the present invention, the advantage on many acoustics is arranged, especially, this pipe fitting can be done simple and easy and cheap transformation as described in hereinafter will having.

The another embodiment of silencing apparatus is shown in Fig. 4-6.With Fig. 1 and Fig. 2 embodiment components identical with identical figure number sign, the different persons of institute are for adding the apostrophe difference on number.Silencing apparatus 22 ' have with an inlet tube 24 ' and outer pipe 20 ' housing 26 '.Transfer tube 70 of silencing apparatus 22 ' also have.Inlet tube 24 ', transfer tube 70 and outer pipe 20 ' with some insulation boards 28 ' be supported on housing 26 ' in.A porose part 60 of inlet tube 24 ' have ', near an end wall 56 of outlet end 58 ' located '.The part 72 that transfer tube 70 is porose.The part 50 of outer pipe 20 ' porose ' and 48 '.Silencing apparatus 22 ' expansion chamber 74,76 is arranged, 78 and 86, on insulation board 84, there is opening (end shows among the figure) that expansion chamber 74 and 86 is communicated.Waste gas is from inlet tube 24 ' enter, and the back of expanding is by meshed portion 60 ' enter expansion chamber 74, and silencing apparatus 22 ' in pass through.Waste gas enters the inlet that turns up of the transfer tube 70 of 86 li of expansion chambers by the perforate on the insulation board 84 through expansion chamber 86, perhaps enter the meshed portion 72 of transfer tube 70.The waste gas that transfer tube is 70 li flows through from meshed portion 72, enters expansion chamber 76, also may flow out from outlet end 88.So waste gas in either case all from outer frayed end 36 ' enter outer pipe 20 ', perhaps by meshed portion 50 ' enter.From outlet end 40 ' leave silencing apparatus 22 ' in the past, a part is at the waste gas of outer pipe 20 ' lining at whole waste gas, after passing through meshed portion 48 ' enter expansion chamber 78, passed through another noise elimination.

Silencing apparatus 22 ' outer pipe 20 ' the entrance point part and the outlet end of transfer tube 70 part on, the part of undergauge is arranged.The part that so just can recognize diameter reduction can be arranged on outer pipe other pipes in addition, also can be arranged on entrance point other pipe ends in addition.The contraction of caliber has cloverleaf shape as shown in Figure 5, and this shape is similar for example to Fig. 3 C's.Diameter shrinkage part can increase silencing apparatus 22 ' area ratio, and increase the actual volume of expansion chamber 76.Outer pipe 20 ' outer frayed end 36 ' as shown in Figure 6, existing described as mentioned, play a part in silencing apparatus 22 ' middle reduction back pressure.As can be seen larynx neck 38 ' be outer pipe 20 ' innermost periphery.

Shown in Fig. 7 and 8, also has " the embodiment of expression silencing apparatus another kind of with label 22.At silencing apparatus 22 on the protruding lobe 90 of " in, insulation board 44 " is fixed on outer pipe 20 " diameter shrinkage part 30 ".Insulation board 44 " this allocation method, give between the round internal diameter 96 of outer pipe 20 " periphery that fold is arranged 94 and insulation board 44 ", the space 92 of an opening is provided.Like this, when waste gas feeds expansion chamber 100 from expansion chamber 98, can pass through open space 92, perhaps enter outer turned welt 36 ", the back of expanding is by passing through the meshed portion 48 " and from outer pipe 20 ".

Propose according to the present invention, be used for one or more pipe fitting that the sound suppresses apparatus, it is novel that the processing method that is suppressed with the diameter shrinkage part of fold also belongs to.Be used to be suppressed with undergauge pipe fitting 20 instrument 102 as shown in Figure 9.Instrument 102 among Fig. 9 can be as mentioned below, is used to make the 8 font undergauges similar to Fig. 3 B, perhaps can make other structural type with similar instrument, for example the structural type among Fig. 3 A-3D.Instrument 102 has a pair of type heart 104, and for example, its shape or diameter equate with the internal diameter of the protruding lobe of pipe fitting 20.The type heart 104 has straight line end 106 and 108 to join at circumference joint-cutting 110 places.End 108 is in its expansion bottom, in order to form the outer frayed end 36 of pipe fitting 20.

Two center lines of the type heart 104 are determined first plane.During two blades 112 were decided on second plane, this plane was vertical with first plane, on the center line between two the type heart 104 center lines on first plane.Blade 112 has blunt sword in order to avoid pipe 20 is isolated, but can form suitable fold groove when pipe 20 axially is pressed onto blade 112.Blade 112 is from the workpiece inlet end 114 of instrument 102, and is adjacent to each other gradually towards far-end 116.Their angle, the mutual distance between, and and the distance of the type heart, the inclination and the length of the undergauge on the decision diameter shrinkage part 30.

The position of center line of the handing-over line decision instrument 102 on above-mentioned first and second planes of instrument 102.When a pipe fitting, for example manage 220(and see Figure 10) when being expressed on the instrument 102, the central lines of the center line of instrument 102 and pipe 220.No matter the type heart is two or more, and all with the equidistant placement of the center line of instrument 102, the plate that forms blade 112 is placed in the radial plane of tool focus line.Blade at most only part reaches in the circumference of pipe fitting 220.Utilize thisly hereinafter with the apparatus that is described in detail, pipe 220 when pushing, is being formed diameter shrinkage part on instrument 102, its protruding lobe all has equal distance apart from the center line of instrument 102, and fold all faces toward 220 center line.

Instrument 102 has a base plate 118 that can retreat with respect to frame 120.Like this, managed 20 o'clock in compacting, base plate 118 can retreat, and the type heart 104 can separate at circumference 110 places, and when the pressure on the pipe fitting that presses was removed, compacted spring 112 pushed out the pipe fittings that press from the cylindrical part 106 on the type heart 104.

The pressing process of pipe fitting is by Figure 10 and 11 explanations.Instrument 102 is fixed on the fixed structure 124.Clamping assembly parts 126 is connected in 114 ends of instrument 102 and is supporting an insulation board, as 244.Second clamping assembly parts 128 is fixed on the press structure 130.Second clamping assembly parts supports an insulation board 242.Pipe 220 is placed between insulation board 244 and 242.Start press (not shown) and pipe 220 then in the contacting point of pipe 220 and insulation board 242, and stretch into pipe contact in 220 o'clock in the type heart 132 parts.Press further acts on then, and first insulation board and second insulation board are pressed on the pipe 220.Meanwhile, when pipe 220 was pushed the instrument 102 of sending to, blade 112 extruded fold on 230 parts, and end 236 outside turnups, as shown in figure 11.When pipe 220 is pulled to the place, end of the type heart 104, press and make the apparatus counter-rotating, the pressure that continues is forward removed.Spring 122 is compacted when pipe 220 is forced into the end of the type heart 104, and overline elongation again shown in the dashed graph among Figure 11 then pushs out pipe 220, so that pipe 220 taking-ups from instrument 102 from the type heart 104.

Need not press shape instrument 104 to carry out similar pressing operation then, third and fourth insulation board is pressed on the inlet tube (as 24), just finished muffler as 22, then inlet tube and outer pipe, promptly 24 and 22, compress into housing, as 26.Last fixing with the silencing apparatus of finishing 22 the insulation board of end at least with welding or additive method.

Manufacture method of the present invention reduces one procedure than existing skill field at least, so its advantageous particularly part is arranged.In existing skill field, require earlier outer pipe to be made, could on pipe, suppress insulation board then.Because process using axial punch compacting outer pipe of the present invention is so pipe fitting axial advance operated pressing tool the time, can be pressed onto insulation board on the pipe simultaneously.Owing to adopt the axial punch operation, and constant circumference pipe manufacturer is simple, thereby can reduces the operation of suppressing pipe fitting and insulation board respectively.

In tiltedly the stating in above, some embodiments have been discussed and have been pointed out its advantage, the structure of various embodiments and the details of effect comprise that novel manufacture method all is described herein as above.Yet these advantages and details all are the representativeness narrations that belongs to notion, thereby belong to illustrative.Therefore, as do any change, special as about shape, size is arranged and the change of aspects such as the combination of well known elements and assembling, and all expressed scope persons of general sense who belongs to the vocabulary in the accompanying Claim now should belong to principle of the present invention.

Claims (5)

1, a kind of muffler includes a housing, and this housing has the wall of a closed curve shape, and two relative end is sealed by the end insulation board; An expansion chamber that between middle insulation board, forms by housing; One is passed and is fixed on inlet tube on an end insulation board and the adjacent middle insulation board and one and passes and be fixed on outer pipe on another end insulation board and the adjacent middle insulation board, this muffler have one from inlet tube through the fluid flow path of expansion chamber to outer pipe, the outer pipe that it is characterized in that this muffler has a undergauge that is formed by the fold that leads to outer frayed end partly, eliminates the noise or the effect of the decay sound thereby back pressure is reduced and the volume of expansion chamber is enlarged to strengthen.

2, according to the muffler of claim 1, it is characterized in that described diameter shrinkage part comprises a porose part, and have that insulation board stretches in the middle of one between the meshed portion of described shell body wall and described diameter shrinkage part, between this centre insulation board and the described outer pipe in space of formation, described fold place.

3,, it is characterized in that described outer pipe circumference substantially constant on any position of its whole length according to the muffler of claim 1.

4,, it is characterized in that described diameter shrinkage part includes the protruding lobe of a plurality of interconnective arcs according to the muffler of claim 1.

5,, it is characterized in that described diameter shrinkage part is to be contracted to aditus laryngis cross section before entrance point flange expansion gradually from a sectional shape near the outlet end of outer pipe according to the muffler of claim 4.

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