CN1080370C

CN1080370C - Exhaust emission control device for internal combustion engines

Info

Publication number: CN1080370C
Application number: CN96193993A
Authority: CN
Inventors: 内田义康; 伊藤信彦; 井之川浩志; 齐藤贤二郎; 岛田信弘
Original assignee: Honda Motor Co Ltd
Current assignee: Honda Motor Co Ltd
Priority date: 1995-05-25
Filing date: 1996-05-24
Publication date: 2002-03-06
Anticipated expiration: 2016-05-24
Also published as: JPH08319824A; KR19980702977A; CN1184523A; JP3614206B2; EP0831211B1; EP0831211A4; KR100401948B1; WO1996037691A1; TW371013U; EP0831211A1

Abstract

The exhaust purification device is provided with a thin-walled steel plate (22) with catalyst metal at the central part of the new surface of the exhaust pipe (5) extending from the exhaust port (4) of the engine (3). That is to say, since the catalyst metal is disposed in the central part of the section of the exhaust pipe (5) where the exhaust temperature is relatively high, in addition to fully exerting the purifying effect of the exhaust gas, the cost of the device can be reduced.

Description

The Exhaust gas purifying device of internal-combustion engine

Technical field

The present invention relates to that a kind of to be used to purify from internal-combustion engine be the improvement of the Exhaust gas purifying device of the motor discharge gas of discharging.

Background technique

In the past, Exhaust gas purifying device as internal-combustion engine, for example " Exhaust gas purifying device of internal-combustion engine " and the openly flat 4-287821 communique disclosed " Exhaust gas purifying devices of motorcycle etc. " of Japan's special permission that the 3-85316 communique is disclosed openly put down in Japan's special permission, has been public technology.

" Exhaust gas purifying device of internal-combustion engine " that the openly flat 3-85316 communique of above-mentioned Japan special permission is disclosed is as Figure 17 and shown in Figure 180, outlet pipe 100 links to each other with the relief opening of compact internal combustion engine on being installed in motorcycle etc., be provided with the interior pipe of making by porous slab 101 along the inwall of this outlet pipe 100 to extend with outlet pipe 100 equidirectionals, in this on wall of pipe 101 with containing catalyst carrier 102.

The openly flat 4-287821 communique disclosed " Exhaust gas purifying devices of motorcycle etc. " of above-mentioned Japan special permission is as Figure 19, Figure 20 and shown in Figure 21, exhaust silencer 110 links to each other with the relief opening of compact internal combustion engine on being installed in motorcycle etc., the Section Central portion of this exhaust silencer (being equivalent to outlet pipe) 110 is provided with catalyst tube 111, in this catalyst tube 111 catalyst body 112 is installed.Catalyst body 112 is attached with catalyst material on the catalyst element of cellular structure.

In general, turn usefulness into, must make catalyzer activate at high temperature in order to give full play to activity of such catalysts.But for compact internal combustion engine, it is very difficult improving delivery temperature for the degree that reaches catalyst activityization.For this reason, not only need to consider to improve as far as possible the temperature of catalyzer, but also need to consider through the effluent air temp of exhaust pipe flow at the Section Central position of pipe than higher, and near tube wall relatively low this fact.

But, Figure 17 and " the discharge gas cleaning device of internal-combustion engine " shown in Figure 180, owing to be provided with the interior pipe 101 of band catalyzer along the inwall of outlet pipe 100, thereby be difficult to give full play to catharsis.

Figure 19～" Exhaust gas purifying devices of motorcycle etc. " shown in Figure 21 is provided with catalyst body 112 at the central position of exhaust silencer 110 sections, because delivery temperature than higher, is easy to bring into play catharsis.But, the catalyst body 112 that constitutes by the catalyst element of cellular structure, compare with the interior pipe 101 that above-mentioned Figure 17 and porous slab shown in Figure 180 are made, its pressure loss is big, the flow velocity of the discharge gas that process exhaust silencer 110 flows is managed the Section Central position than higher, thereby the pressure loss is bigger.As a result, the pressure loss is brought very big influence to engine performance, and particularly concerning the internal-combustion engine of the so low output of motorcycle, this is very important key element.In addition, the catalyst body 112 that is made of the catalyst element of cellular structure is installed in this structure in the catalyst tube 111, compares with the structure that above-mentioned Figure 17 and interior pipe 101 shown in Figure 180 are configured in the outlet pipe 100, has more increased manufacture cost.

The announcement of invention

Therefore, the purpose of this invention is to provide a kind of (1) and give full play to catharsis, (2) as far as possible not to the Exhaust gas purifying device of the internal-combustion engine that performance impacts, (3) expense is low of internal-combustion engine.

The present invention is provided with the thin-walled steel plate of being with catalyst metals at the substantial middle position of the outlet pipe section that the relief opening from this internal-combustion engine extends.Therefore, in outlet pipe, catalyst metals is arranged on the substantial middle position of the high section of delivery temperature, can makes the catalyst metals activate, give full play to the gas cleaning effect of discharging.

As aforementioned thin-walled steel plate, owing to, therefore, can reduce and discharge gas through the out-of-date pressure loss preferably along the axially extended cylindrical shell of aforementioned outlet pipe.

Aforementioned cylindrical shell is made of porous slab, and the exhaust-gas upstream side of cylindrical shell is preferably sealed.That is to say that because discharge gas process is opened in several holes on the barrel wall, thereby discharging gas can contact with the catalyst metals on the second carrier inner and outer surface.As a result, can increase and discharge the area that gas contacts with catalyst metals, improve the gas cleaning effect of discharging.

Further, the present invention is at the substantial middle position of the outlet pipe section that extends from the relief opening of internal-combustion engine, be provided with the cylindrical shell of making by the thin-walled steel plate along the axially extended band catalyst metals of outlet pipe, in aforementioned outlet pipe, be supported with the cylindrical shell that aforementioned thin-walled steel plate is made, and, be provided with and be used to seal the cylindrical shell that aforementioned thin-walled steel plate makes and the dividing plate of the path between the outlet pipe.That is to say that dividing plate separates before and after it, has limited the pulsation from the discharge gas of internal-combustion engine, making flows roughly becomes level and smooth stable flowing.Like this, the purifying ability of Exhaust gas purifying device can not change, thereby has improved catharsis.Because the dividing plate that utilizes restriction to discharge air pulsing supports the cylindrical shell that the thin-walled steel plate is made, therefore do not need to use special supporting part in addition.

Moreover, the cylindrical shell that aforementioned thin-walled steel plate is made, with respect to aforementioned outlet pipe vertically telescopically be installed with, thereby, can absorb and occur in the poor of cylindrical shell that the thin-walled steel plate makes and the elongation between the outlet pipe along with thermal expansion.

Further, the Exhaust gas purifying device of internal-combustion engine of the present invention, along near first carrier that is provided with the band catalyst metals inwall of the outlet pipe that extends from this internal combustion engine air vent, has second carrier of catalyst metals in the configuration of the substantial middle position of this first carrier section.That is to say that near two positions, substantial middle position that reach section the inwall of outlet pipe are provided with the carrier of band catalyst metals, therefore, can the performance of internal-combustion engine not had a negative impact, and can further improve the gas cleaning effect of discharging.

The simple declaration of drawing

Fig. 1 is the profile of motorcycle of Exhaust gas purifying device that the internal-combustion engine of first embodiment of the invention is housed.

Fig. 2 is outlet pipe first an embodiment's of the present invention profile.

Fig. 3 is the A-A sectional view among Fig. 2.

Fig. 4 is the B-B sectional view among Fig. 3.

Fig. 5 is first embodiment's of the present invention's second Exhaust gas purifying device a stereogram.

Fig. 6 is the C-C sectional view among Fig. 2.

Fig. 7 is the D-D sectional view among Fig. 6.

Fig. 8 is the E-E sectional view among Fig. 6.

Fig. 9 A～Fig. 9 E is first embodiment's of the present invention's second carrier assembling instruction figure.

Figure 10 A～Figure 10 D is first embodiment's of the present invention's second carrier a variation schematic representation.

Figure 11 A～Figure 11 H is the variation schematic representation of first embodiment's supporting structure of the present invention's second carrier.

Figure 12 is the stereogram of second embodiment's second Exhaust gas purifying device.

Figure 13 is the F-F sectional view among Figure 12.

Figure 14 is the variation schematic representation of second embodiment's second Exhaust gas purifying device.

Figure 15 is the G-G sectional view among Figure 14.

The structure diagram of Figure 16 A～Figure 16 E the 3rd embodiment's Exhaust gas purifying device.

Figure 17 is the outlet pipe cross-section profile of prior art.

Figure 18 is the local profile diagram of the outlet pipe of prior art.

Figure 19 is the planimetric map of the exhaust silencer of prior art.

Figure 20 is the local section stereogram of the Exhaust gas purifying device of prior art.

Figure 21 is near the profile diagram of the structure of catalyst tube of expression prior art.

The optimised form that carries out an invention

Narrate embodiments of the invention below with reference to the accompanying drawings.At first first embodiment is described with reference to Fig. 1～Fig. 9.

In Fig. 1, motorcycle 1 is equipped with two-stroke type motor (internal-combustion engine) 3 near car body 2 central authorities, and the relief opening 4 of motor 3 is connected with outlet pipe 5, and the rear portion of this outlet pipe 5 is connected with silencing apparatus 6.

Fig. 2 shows outlet pipe 5 of the present invention.It is circular structure that this outlet pipe 5 is made section by the thin-walled steel plate, one end 5a is connected on the relief opening 4 (with reference to Fig. 1) of motor 3 by flange, the other end 5b is connected with silencing apparatus 6 (with reference to Fig. 1) by flange, and first Exhaust gas purifying device 10 of exhaust-gas upstream side and second Exhaust gas purifying device 20 in exhaust downstream side are equipped with in its inside.First Exhaust gas purifying device 10 is prime purification plants, and second Exhaust gas purifying device 20 is back level purification plants.The part of second Exhaust gas purifying device 20 in the configuration exhaust downstream side of outlet pipe 5 is bigger than the diameter of other parts.

Fig. 3 shows the cross-sectional configuration of aforementioned first Exhaust gas purifying device 10.

First Exhaust gas purifying device 10 is made up of the interior pipe 11 that is arranged in the outlet pipe 5.Should in pipe 11 be along outlet pipe 5 inwalls and cylindrical bodys these outlet pipe 5 equidirectional extensions, and the porous slab of being made by the thin-walled steel plate constitutes.Interior pipe 11 one end 11a are fixed by welding on the outlet pipe 5, and the other end 11b is supported by supporting part 13, can be flexible vertically with respect to outlet pipe 5.Like this, can absorb along with thermal expansion is created in the poor of the amount of extending axially between outlet pipe 5 and the interior pipe 11.

Interior pipe 11 is provided with the precious metal (methods such as solution that contain precious metal by coating are adhered to) that platinum or rhodium etc. have catalyst function on the wall that has a plurality of hole 11c.The size of the intermediate portion of outlet pipe 5 for can and interior pipe 11 between be provided with space 5c.

Outlet pipe 5 among Fig. 4 is made the semicircle tubular of radially cutting apart, and is under the state of pipe 11, that these two semicircle barrel are integrally welded in interior being equipped with.

Supporting part 13 is by being rolled into corrugated sheet (corrugated sheet) cylindric and the face that will overlap is fixed the wavy texture of making along the circumferential direction with spot welding.Therefore, supporting part 13 can be with respect to outlet pipe 5 at radial expansion by resiliently deformable, and it is poor to absorb the outlet pipe 5 and the elongation between the interior pipe 11 that cause because of thermal expansion.But supporting part 13 is not limited to the structure that is made of the forementioned waveform plate, for example can also adopt by enrolling STAINLESS STEEL WIRE and do circlewise structure.

Symbol

14,14 expressions are used for the guard member of covering high-temperature outlet pipe 5, make radially cut apart a pair of.This

guard member

14,14 is fixed by bolts on several nuts 15 that are welded on outlet pipe 5 outer circumferential faces.

In Fig. 5, show the present invention's second Exhaust gas purifying device 20.This second Exhaust gas purifying device 20 is along being provided with a pair of

first carrier

21,21 near the internal face of outlet pipe 5, the substantial middle portion of the section of this first carrier 21,21 (the substantial middle portion of outlet pipe 5) disposes second carrier, 22, the

first carriers

21,21 and second carrier 22 extending axially along outlet pipe 5.

First carrier

21,21 is made of a pair of semicircle cylindrical shell of radially cutting apart, and second carrier 22 is made of the column cylindrical body of diameter less than

first carrier

21,21, and the porous slab that

first carrier

21,21 and second carrier 22 are made by the thin-walled steel plate constitutes.

First carrier

21,21 and second carrier 22 are provided with the precious metal (methods such as solution that contain precious metal by coating are adhered to) that platinum or rhodium etc. have catalyst function respectively on the wall that has a plurality of holes (21a, 22c).The size of outlet pipe 5 make and

first carrier

21,21 between have the structure in gap.

In Fig. 6, the exhaust-gas upstream side in outlet pipe 5 (left side of this figure) is provided with supporting part 23, is used to support an end 22a of second carrier 22, and second carrier 22 can be stretched vertically with respect to outlet pipe 5.This supporting part 23 has an end 22a who supports second carrier 22 and makes buffer unit 24 that this end 22a can pass, is used to install the annular mount 25 of this buffer unit 24 and this bearing 25 is fixed on carriage 26 on the outlet pipe 5.Therefore, can absorb the poor of the amount of extending axially that occurs in along with thermal expansion between the outlet pipe 5 and second carrier 22.

Exhaust downstream side in outlet pipe 5 (right side of this figure) is provided with the dividing plate 27 that is used to support second carrier 22 and blocks the path between this second carrier 22 and the outlet pipe 5.The aforementioned separator plate 27 that the end plate of being made by the thin-walled steel plate (end plate that slightly is dish) is constituted, by its flange part 27a plug welding is fixed on the outlet pipe 5, and allows the other end 22b of second carrier 22 insert and to be welded among the through hole 27b at substantial middle position of section and fix.One end (exhaust-gas upstream side) 22a of second carrier 22 is blocked by lid 28.

In Fig. 7, buffer unit 24 is by being rolled into corrugated sheet (corrugated sheet) cylindric and the face that will overlap is fixed the wavy texture of making along the circumferential direction with spot welding.Therefore, buffer unit 24 can be with respect to outlet pipe 5 at radial expansion by resiliently deformable, and it is poor to absorb the outlet pipe 5 and the elongation between second carrier 22 that cause because of thermal expansion.

As shown in Figure 8, a pair of

first carrier

21,21 two end part separately are fixed near the edge part of the outlet pipe of radially cutting apart 5 by spot welding.

Hereinafter according to the assembling sequence of second carrier 22 of Fig. 6 and Fig. 9 A～Fig. 9 E narration said structure.

At first, shown in Fig. 9 A, lid 28 is entrenched on the end 22a of second carrier 22, then shown in Fig. 9 B, an end 22a and the edge part of lid 28 of second carrier 22 is fixed by spot welding, and an end 22a is blocked.

Then, shown in Fig. 9 C, the other end 22b of second carrier 22 is inserted among the through hole 27b of dividing plate 27, and be fixed by welding in together.

Subsequently, shown in Fig. 9 D, the bearing 25 that buffer unit 24 (with reference to Fig. 6) will be installed inserts an end 22a of second carrier 22, is assembled into the posture shown in the 9E.

At last, will be shown in Fig. 9 E second carrier 22 of posture be positioned at half point shown in Figure 6 and cut within the Lower Half of shape outlet pipe 5, bearing 25 is welded on the carriage 26 of predetermined fixed, cover and two and half ones about described are welded together with upper half part of outlet pipe 5, flange part 27a with dividing plate 27 links together by plug welding with outlet pipe 5, has just finished assembling operation.

Hereinafter narrate the effect of first Exhaust gas purifying device 10 and second Exhaust gas purifying device 20 according to Fig. 2, Fig. 6.

As shown in Figure 2, the discharge gas of motor is during from an end 5a side inflow of outlet pipe 5 and by first Exhaust gas purifying device 10, contact with precious metal on the interior pipe 11 to react, and purifies back arrival second Exhaust gas purifying device 20.

As shown in Figure 6, in second Exhaust gas purifying device 20, discharge gas and flow from the left side of this figure.But because an end 22a of second carrier 22 is blocked by lid 28, therefore discharging gas can not flow into from this end 22a.

The part that outlet pipe 5 is provided with second Exhaust gas purifying device 20 is bigger than the diameter of other parts, by by the separation of dividing plate 27 to its front and back, makes exhaust-gas upstream side become expansion chamber 29.Therefore, utilize expansion chamber 29 can limit pulsation, make and discharge gas flow and roughly become level and smooth stable flowing from the discharge gas of motor 3.Thereby, to discharge gas and near the tube wall of outlet pipe 5, flow along direction shown in Fig. 6 arrow, the precious metal haptoreaction on this discharge gas and

first carrier

21,21 is to reach the purpose of purification.

Further, discharge gas and enter in second carrier 22, be discharged into the atmosphere from the exhaust downstream side of outlet pipe by the other end 22b by several holes 22c that is opened on second carrier, 22 walls.When discharging gas, contact with precious metal on second carrier 22 and to react, make it purification through second carrier 22.

In this occasion, owing to discharge gas by being opened in several holes 22c on second carrier, 22 walls, contact with the catalyst metals on second carrier, 22 inner and outer surface, thereby can increase the area of contact of discharging gas and catalyst metals, give full play to the catharsis of catalyst metals.

As above-mentioned,, must at high temperature make catalyst activityization in order to give full play to the catharsis of catalyst metals.On the other hand, the temperature of the discharge gas that flows through outlet pipe 5 at the Section Central position of pipe than higher.Because the temperature that flows through the Section Central position of outlet pipe 5 is than higher discharge gas, also with pass through under catalyst metals contact, therefore, second carrier 22 can make catalyst temperature increase and abundant activate, has given full play to catharsis.In addition because second carrier 22 is to be made of the cylindrical shell that porous slab is made, therefore, can reduce discharge gas by the time the pressure loss, reduce influence to engine performance.

Like this, discharge gas and contact, react and purify with precious metal on

first carrier

21,21 and second carrier 22, thereby the purification efficiency height.In addition, be roughly level and smooth steady flow owing to discharge gas flow, therefore the purifying ability of second Exhaust gas purifying device 20 is constant, the purification efficiency height.

Second carrier 22 makes its temperature be higher than the temperature of outlet pipe 5 by reaction heat etc.Because the other end 22b of second carrier 22 is fixed on the outlet pipe 5 by dividing plate 27, thereby when between the outlet pipe 5 and second carrier 22 the elongation difference taking place along with thermal expansion, one end 22a of this second carrier 22 can extend along the hollow arrow direction, thereby absorbs the poor of this elongation with this second carrier 22.Radially elongation difference between the outlet pipe 5 and second carrier 22 can absorb by the resiliently deformable of buffer unit 24.

Aforementioned second carrier 22 has adopted and has discharged the structure that the gas upstream side seal closes, and still, also can adopt for example structure shown in Figure 10 A～Figure 10 D.

Figure 10 A～Figure 10 D shows the variation about above-mentioned first embodiment's second carrier 22.

The end 22a that Figure 10 A shows second carrier 22 is by the structures of lid 31 sealings, and lid 31 is made by the porous slab that bloats to exhaust-gas upstream side, and forms by drawing.

The end 22a that Figure 10 B shows second carrier 22 makes the structure of flat conduct lid 32 by extruding.

The end 22a that Figure 10 C shows at second carrier 22 is equipped with the structure of the plate that several pieces of porous slabs make, and the plate that these several pieces of porous slabs are made is mounted to helical (windmill shape) and as lid 33, discharges the gas flow resistance to increase.

The structure that the lid 34 that the end 22a that Figure 10 D shows at second carrier 22 is made by flat porous slab seals.The lid 34 that the planar porous slab that replacement is installed is made can also adopt an end 22a itself is constituted the structure of flat lid with the sealing exhaust-gas upstream side towards second carrier, 22 centers, one side flanging.

So respectively covering shown in Figure 10 A～Figure 10

D

31,32,33,34 has the effect same with first embodiment's structure, and, owing to make by porous slab, therefore respectively cover 31,32,33,34 by being provided with, compare, can further reduce the pressure loss with first embodiment's structure.

The supporting structure of second carrier 22 is, an end of second carrier 22 with respect to outlet pipe 5 vertically telescopically supporting, the other end is fixed on the outlet pipe 5, for example can adopt the structure shown in Figure 11 A～Figure 11 H.

Figure 11 A～Figure 11 H shows the variation of first embodiment's second carrier, 22 supporting structures.Discharge gas direction shown in the arrow in these figure and flow, an end 22a of second carrier 22 is caused along the elongation of direction shown in the hollow arrow by thermal expansion.

The supporting structure of second carrier 22 shown in Figure 11 A is, an end 22a of second carrier 22 extends from supporting part 23 towards exhaust-gas upstream side, and an end 22a is by flat lid 28 sealings.

The supporting structure of second carrier 22 shown in Figure 11 B adopts the structure of the exhaust-gas upstream side (left side of this figure) of supporting part 23 by lid 36 sealings.One end 22a and lid have the gap S1 of the elongation that causes because of thermal expansion greater than second carrier 22 between 36.In this occasion, need be on an end 22a of second carrier 22 mounting cover.

The supporting structure of second carrier 22 shown in Figure 11 C, the bearing 25 that adopts supporting part 23 is along the axial length of outlet pipe 5 structure longer than carriage 26.

The supporting structure of second carrier 22 shown in Figure 11 D adopts second carrier 22 only to be supported the structure of one end by dividing plate 27.Supporting part 37 by buffer unit 38, hold the bearing 39 of this buffer unit 38 and dividing plate 27 that this bearing 39 is fixed on the outlet pipe 5 constitutes, buffer unit 38 is supporting the other end 22b of second carrier 22, makes this other end 22b can be along the axial stretching of outlet pipe 5.Have gap S2 between the flange 39a of the other end 22b and bearing 39, this gap S2 is limited in amount of movement and the elongation of the other end 22b in the scope of this gap S2.

Figure 11 E shows the variation of Figure 11 D structure, and the length of buffer unit 38 and bearing 39 is shorter than the structure of Figure 11 D.

The supporting structure of second carrier 22 shown in Figure 11 F, an end 22a who has adopted second carrier 22 by carriage 41 be fixed on the outlet pipe 5, the other end 22b of second carrier 22 by supporting part 42 support, can be along the structure of the two end supports of the axial stretching of outlet pipe 5.Supporting part 42 by buffer unit 43, hold the bearing 44 of buffer unit 43 and dividing plate 27 that bearing 44 is fixed on the outlet pipe 5 constitutes, buffer unit 43 is supporting the other end 22b of second carrier 22, makes this other end 22b can be along the axial stretching of outlet pipe 5.The other end 22b is from supporting part 42 (left side of this figure) extension towards the exhaust downstream side.

The supporting structure of second carrier 22 shown in Figure 11 G is variation of Figure 11 F structure, adopts the end 22a mounting cover 45 at second carrier 22, the structure of sealing this end 22a, and described lid 45 has die-cut pawl.

Figure 11 H is the variation of above-mentioned

buffer unit

24,38,43, has adopted by enrolling STAINLESS STEEL WIRE and has done circlewise buffer unit 48.For example, supporting part 46 by be wound on seat board 47 on second carrier, 22 the other end 22b, be inserted on this seat board 47 and supporting the other end 22b make this other end 22b can be along former and later two buffer units 48 of the axial stretching of outlet pipe 5, be used to hold the cylindric bearing 49 of these two buffer units 48 and dividing plate 27 that this bearing 49 is fixed on the outlet pipe 5 constitutes.

Hereinafter narrate second embodiment of second Exhaust gas purifying device according to Figure 12 and Figure 13.

In Figure 12, second Exhaust gas purifying device 50 is along being provided with first carrier 51 near the internal face of outlet pipe 5, and the substantial middle portion of the section of this first carrier 51 (the substantial middle portion of the section of outlet pipe 5) is provided with second carrier 52.First carrier 51 and second carrier 52 extending axially along outlet pipe 5.

Aforementioned first carrier 51 is made of cylindrical body, and its axial two end part have

conus portion

51a, 51a, and the side of this

conus portion

51a, 51a or two square tubes are crossed and are weldingly fixed on the outlet pipe 5.Second carrier 52 is made of flat board, and the one or both ends of its length direction are fixed by welding in first carrier 51.

The porous slab that first carrier 51 and second carrier 52 are made by the thin-walled steel plate constitutes.First carrier 51 and second carrier 52 on the wall that has a plurality of

hole

51c, 52a, are provided with the precious metal (methods such as solution that contain precious metal by coating are adhered to) that platinum or rhodium etc. have catalyst function respectively.

Figure 13 shows the state that second carrier 52 that is made of flat board is holded up in first carrier 51.

Hereinafter narrate the effect of above-mentioned second embodiment's second Exhaust gas purifying device 50 with reference to Figure 12.

The discharge gas of motor flows along the direction shown in the arrow among this figure, through near the discharge gas that flows the tube wall, flow by several holes 51c that is opened on first carrier, 51 walls, pass several holes 52a that is opened on second carrier, 52 walls through the mobile discharge gas in section substantial middle position and flow.Therefore, the precious metal haptoreaction on this discharge gas and first carrier 51 and second carrier 52 is to reach the purpose of purification.

In this occasion, owing to discharge gas by being opened in several holes 52a on second carrier, 52 walls, contact with the catalyst metals on second carrier, 52 inner and outer surface, thereby can increase the area of contact of discharging gas and catalyst metals, give full play to the catharsis of catalyst metals.

Precious metal on second carrier 52 can become high temperature because of contacting than higher discharge gas with the temperature that flows through the Section Central position of outlet pipe 5, and catharsis is brought into play in fully activate fully.

Because second carrier 52 is by constituting along outlet pipe 5 axially extended flat boards, therefore, compare with aforementioned first embodiment's structure, can further reduce discharge gas by the time the pressure loss.

Above-mentioned second embodiment's second Exhaust gas purifying device 50 can also adopt the structure of Figure 14 and 15.

That is to say that Figure 14 shows the variation of second embodiment's second Exhaust gas purifying device 50.The section configuration of first carrier 51 is notched circle cross sections, a cylindrical body part (for example bottom of Figure 14) is radially cut form.

In Figure 15, the lip part 51b, the 51b that are formed by the bending of notched section two edges of first carrier 51 are connected on the inwall of outlet pipe 5.Second carrier 52 runs through the barbed portion of first carrier 51 and is connected on the inwall of outlet pipe 5.

Figure 16 A～16E shows the brief configuration of the Exhaust gas purifying device of third embodiment of the invention.

The Exhaust gas purifying device 61 of Figure 16 A adopts the structure that is provided with the front and back stages purification plant in outlet pipe 5, between prime purification plant and the back level purification plant modulating valve (for example butterfly valve) 62 that is used to regulate air displacement is housed.The prime purification plant adopts the structure of aforementioned first Exhaust gas purifying device 10 shown in Figure 3, and back level purification plant adopts the structure of aforementioned second Exhaust gas purifying device 50 shown in Figure 12.

The structure of three grades of purification plants before and after Exhaust gas purifying device 63 among Figure 16 B adopts and is provided with in outlet pipe 5.The prime purification plant adopts the structure of aforementioned first Exhaust gas purifying device 10 shown in Figure 3, the purification plant of middle one-level adopts the structure of aforementioned second Exhaust gas purifying device 50 shown in Figure 12, and back level purification plant adopts the structure that extends to the delivery line 64 in the outlet pipe 5 from the other end 5b of outlet pipe 5.The porous slab that this delivery line 64 is made by the thin-walled steel plate constitutes, and is having on the wall in a plurality of holes, is provided with the precious metal (methods such as solution that contain precious metal by coating are adhered to) that platinum or rhodium etc. have catalyst function.

The Exhaust gas purifying device 65 section substantial middle portion at outlet pipe 5 that adopts of Figure 16 C is provided with along the structure of outlet pipe 5 axially extended carriers 66.This carrier 66 is the flat boards that are made of the porous slab that the thin-walled steel plate is made, and is having on the wall in a plurality of holes, is provided with the precious metal (methods such as solution that contain precious metal by coating are adhered to) that platinum or rhodium etc. have catalyst function.

The Exhaust gas purifying device 67 of Figure 16 D is variation of Exhaust gas purifying device shown in above-mentioned Figure 16 C, replaces plate-like structure, and carrier 66 adopts corrugated sheet (corrugated sheet) structure.

The Exhaust gas purifying device 68 of Figure 16 E adopts the structure of configuration semicircle tubular carrier 69, and semicircle tubular carrier 69 is closed along outlet pipe 5 axially extended axial two ends.The radially open end 69a of carrier 69 is configured in the section substantial middle portion of outlet pipe 5.The porous slab that carrier 69 is made by the thin-walled steel plate constitutes, and is having on the wall in a plurality of holes, is provided with the precious metal (methods such as solution that contain precious metal by coating are adhered to) that platinum or rhodium etc. have catalyst function.

Carrier

66,69 shown in Figure 16 C, Figure 16 D and Figure 16 E also is applicable to the structure that disposes the multistage purification device in outlet pipe 5 shown in Figure 16 A and Figure 16 B.

Above-mentioned first, second, " the thin-walled steel plate " that have catalyst metals in the 3rd embodiment and the variation thereof, be arranged on the section substantial middle portion or first carrier 21 of

outlet pipe

5,51 section substantial middle portion, as concrete example, for as Fig. 1～first embodiment and Figure 10 shown in Figure 9, variation shown in Figure 11, the structure of second carrier 22 that the cylindrical shell that employing is made by porous slab constitutes, for Figure 12, second embodiment shown in Figure 13, Figure 14, variation shown in Figure 15 and Figure 16 A, the structure of second carrier 52 that the flat board that the 3rd embodiment employing shown in Figure 16 B is made by porous slab constitutes, for Figure 16 C, the 3rd embodiment shown in Figure 16 D and Figure 16 E adopts the flat board of being made by porous slab, the carrier 66 that corrugated sheet or half tubular constitute, 69 structure.

Like this, in the present invention, " thin-walled steel plate " is not limited to the structure of the various embodiments described above or its variation, and to the structure of porous slab also without any qualification, the hole shape of porous slab, hole size and quantity can be arbitrarily.

Industrial application possibility

The emission-control equipment of the internal combustion engine of the invention described above is owing to extend from the exhaust outlet of internal combustion engine The substantial middle position of blast pipe section be provided with thin-walled steel plate with catalyst metals, like this, So that catalyst metals is arranged on the substantial middle position of the high section of delivery temperature, therefore, can make Its exhaust gas purification effect is given full play in the catalyst metals activate, and, can reduce cost.

In addition, the emission-control equipment of internal combustion engine of the present invention is because the thin-walled steel plate is along blast pipe Axially extended cylindrical shell, thereby can reduce exhaust through the out-of-date pressure loss, its advantage is internal The performance of combustion machine can not exert an influence.

Moreover the emission-control equipment of internal combustion engine of the present invention is because cylindrical shell is by the porous plate structure Become, the exhaust upstream side of cylindrical shell is sealed, make that to discharge gas a plurality of through what offer on the barrel wall Therefore the hole, is discharged gas and is contacted with catalyst metals on the Second support surfaces externally and internally. As a result, Can increase and discharge the area that gas contacts with catalyst metals, further improve exhaust gas purification and do With.

Further, the emission-control equipment of internal combustion engine of the present invention is owing to the exhaust outlet from internal combustion engine The substantial middle position of the blast pipe section that extends is provided with along the axially extended band catalysis of blast pipe The cylindrical shell of being made by the thin-walled steel plate of agent metal, the cylindrical shell that the thin-walled steel plate is made is supported on blast pipe In, and the cylindrical shell made of this thin-walled steel plate and the path between the blast pipe seal by dividing plate, this Sample, so that catalyst metals is arranged on the substantial middle position of the high section of delivery temperature, therefore, Can make the catalyst metals activate, give full play to its exhaust gas purification effect, and, can be lowered into This. Also have, owing to utilize dividing plate to separate before and after it, limited the discharge gas from internal combustion engine Pulsation become basicly stable level and smooth flowing so that flow, therefore, can not change exhaust gas purification The detergent power of device can be given full play to its catharsis. In addition, owing to utilize restriction to discharge gas The cylindrical shell that the membrane support thin-walled steel plate of body pulsation is made, thereby do not need special support component, Can simplified support structure.

In addition, the emission-control equipment of internal combustion engine of the present invention is because the cylindrical shell that the thin-walled steel plate is made With respect to blast pipe vertically telescopically be installed with, therefore, be easy to absorb and draw with thermal expansion The cylindrical shell that rises and the extension amount between the blast pipe poor.

Also have, the emission-control equipment of internal combustion engine of the present invention prolongs along the exhaust outlet from internal combustion engine Be provided with first carrier with catalyst metals near the blast pipe internal face of stretching, disconnected at first carrier The substantial middle position of face arranges the Second support with catalyst metals, like this, so that the band catalyst The carrier of metal is arranged near the blast pipe internal face and two positions, substantial middle position of section Put, therefore, under the condition that does not affect engine performance, further improve the exhaust gas purification effect, Has the advantage that can further reduce cost.

Particularly, by first carrier and the coaxial configuration of Second support along the blast pipe internal face, Temperature with above-mentioned first carrier increases, and improves the advantage of the catharsis of catalyst.

Claims

1. An exhaust purification device for an internal combustion engine, comprising an internal combustion engine (3) and an exhaust pipe (5) extending from an exhaust port (4) of the internal combustion engine (3) for purifying exhaust gases from the aforementioned internal combustion engine (3) ), which is characterized by,

In the approximate central part of the section of the aforementioned exhaust pipe (5), a cylindrical body (22) made of a thin-walled steel plate with catalyst metal extending axially along the aforementioned exhaust pipe (5) is provided. (5) inside, be provided with the partition plate ( 27).

2. The exhaust purification device of an internal combustion engine according to claim 1, characterized in that the cylinder (22) made of thin-walled steel plate is telescopically installed in the axial direction relative to the exhaust pipe (5).

3. An exhaust purification device for an internal combustion engine, comprising an internal combustion engine (3) and an exhaust pipe (5) extending from the exhaust port (4) of the internal combustion engine (3) for purifying the exhaust gas from the aforementioned internal combustion engine (3) ), which is characterized by,

A first carrier (21, 51) with a catalyst metal is provided along the vicinity of the inner wall of the exhaust pipe (5), and a second carrier with a catalyst metal is arranged approximately in the center of the section of the first carrier (21, 51). (22, 52), such that the first carrier (21, 51) and the second carrier (22, 52) are arranged coaxially in the approximate center of the larger diameter portion of the exhaust pipe (5).

4. The exhaust purification device of an internal combustion engine according to claim 3, characterized in that, the second carrier (22) is made of a cylindrical body made of a perforated plate, and the upstream side of the exhaust gas is sealed. live.

5. The exhaust gas purification device of an internal combustion engine according to claim 3, characterized in that the first carrier (51) is made of a cylinder, and the second carrier (52) is made of a flat plate.

6. The exhaust purification device of an internal combustion engine according to claim 3, characterized in that the first carrier (21, 51) and the second carrier (22, 52) have several holes (21a, 51c, 22c, 52a ).