GB2108200A - Exhaust gas silencer with porous ceramic sound-absorbing material - Google Patents
Exhaust gas silencer with porous ceramic sound-absorbing material Download PDFInfo
- Publication number
- GB2108200A GB2108200A GB08229072A GB8229072A GB2108200A GB 2108200 A GB2108200 A GB 2108200A GB 08229072 A GB08229072 A GB 08229072A GB 8229072 A GB8229072 A GB 8229072A GB 2108200 A GB2108200 A GB 2108200A
- Authority
- GB
- United Kingdom
- Prior art keywords
- casing
- ceramic element
- exhaust silencer
- diameter
- ceramic
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 239000000919 ceramic Substances 0.000 title claims abstract description 46
- 230000003584 silencer Effects 0.000 title claims abstract description 39
- 239000011358 absorbing material Substances 0.000 title 1
- 229910052751 metal Inorganic materials 0.000 claims abstract description 16
- 239000002184 metal Substances 0.000 claims abstract description 16
- 239000012790 adhesive layer Substances 0.000 claims abstract description 3
- 238000000034 method Methods 0.000 claims description 11
- 238000010276 construction Methods 0.000 claims description 5
- 230000003247 decreasing effect Effects 0.000 claims description 4
- 238000004519 manufacturing process Methods 0.000 claims description 4
- 239000007789 gas Substances 0.000 claims description 3
- 238000010438 heat treatment Methods 0.000 claims description 3
- 229910052729 chemical element Inorganic materials 0.000 claims 2
- 239000000853 adhesive Substances 0.000 description 3
- 238000013016 damping Methods 0.000 description 3
- 230000001070 adhesive effect Effects 0.000 description 2
- 229910010293 ceramic material Inorganic materials 0.000 description 2
- 230000006835 compression Effects 0.000 description 2
- 238000007906 compression Methods 0.000 description 2
- 239000002657 fibrous material Substances 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 1
- 239000004411 aluminium Substances 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000008030 elimination Effects 0.000 description 1
- 238000003379 elimination reaction Methods 0.000 description 1
- 239000010410 layer Substances 0.000 description 1
- 230000010355 oscillation Effects 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N13/00—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00
- F01N13/18—Construction facilitating manufacture, assembly, or disassembly
- F01N13/1838—Construction facilitating manufacture, assembly, or disassembly characterised by the type of connection between parts of exhaust or silencing apparatus, e.g. between housing and tubes, between tubes and baffles
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N1/00—Silencing apparatus characterised by method of silencing
- F01N1/24—Silencing apparatus characterised by method of silencing by using sound-absorbing materials
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N13/00—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00
- F01N13/16—Selection of particular materials
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2310/00—Selection of sound absorbing or insulating material
- F01N2310/06—Porous ceramics
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2450/00—Methods or apparatus for fitting, inserting or repairing different elements
- F01N2450/22—Methods or apparatus for fitting, inserting or repairing different elements by welding or brazing
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2450/00—Methods or apparatus for fitting, inserting or repairing different elements
- F01N2450/28—Methods or apparatus for fitting, inserting or repairing different elements by using adhesive material, e.g. cement
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2470/00—Structure or shape of gas passages, pipes or tubes
- F01N2470/02—Tubes being perforated
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2490/00—Structure, disposition or shape of gas-chambers
- F01N2490/08—Two or more expansion chambers in series separated by apertured walls only
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Exhaust Silencers (AREA)
Abstract
Firmly abutting or adhering to the inner cylindrical wall of the sheet-metal casing (1) is the cylindrical outer surface of at least one ceramic element (6). In order to prevent the occurence of disturbing resonant vibrations in the silencer and in order to provide a rigid structure, the inner wall of the casing (1) is firmly connected to the cylindrical outer surface of the ceramic element (6), for example by heat shrinking the casing around the ceramic element, by press fitting or by an adhesive layer. <IMAGE>
Description
SPECIFICATION
Improvements in or relating to a silencer
THIS INVENTION relates to an exhaust silencer, and also relates to a method of manufacturing a silencer.
Exhaust silencers containing one or more sound-absorbing porous ceramic elements are described in U.K. Patent Application No.
8218892 (Patent Publication No.
These silencers have been found to be extremely effective from the view-point of sound absorption when compared with conventional silencers which are wholly made of sheet metal or include sound-damping fibrous material. The known sound-damping fibrous material is rapidly decomposed and blown out of the silencer, when the silencer is used with an internal combustion engine. Then, of course, the sound-damping effect is seriously decreased. In contrast, a porous ceramic element present within a silencer, remains intact even after a prolonged period of use of the silencer.
A common feature of conventional, previously known silencers is that the casing must be made of relatively thick sheet metal, for example 1.5 mm stainless steel sheet, with the result that the silencer has a relatively large mass. Thus a considerable quantity of raw material is utilised in fabricating such a silencer. A further disadvantage is that the sheet metal casing, and possibly also the components located in the casing, give rise to resonant vibrations. Therefore, the quantity of sound radiated from the outer surface will often exceed the sound emanating from the outlet of the silencer.
The present invention effectively constitutes a further development of the invention described in U.K Patent Application No.
8218892 (Patent Publication No.
and the excellent mechanical properties of the porous ceramic elements described in the said prior application are used to provide a new construction of an exhaust silencer, which makes it possible to use a much thinner sheet metal for the casing of the silencer without decreasing the mechanical strength of the silencer. The new construction also results in a total elimination of, or at least a considerable decrease of, resonant vibrations in the silencer.
According to this invention there is provided an exhaust silencer comprising a casing of sheet metal, and at least one sound-absorbing porous ceramic element with at least one through-going channel for the exhaust gases, the ceramic element being located in said casing casing and having an outer surface firmly connected to a corresponding wall of the casing which embraces the ceramic element, the casing and the ceramic element together forming a rigid construction.
Preferably the casing is heat shrunk onto the ceramic element, but alternatively the casing is a friction fit onto the ceramic element, and in another arrangement the casing is connected to the ceramic element by means of an adhesive layer between the ceramic element and the inner wall of the casing.
Due to the firm connection between the casing and the ceramic element the silencer can be considered as a unitary body or a sandwich construction with a large mass and a large wall thickness. Therefore, the wall thickness of the casing can be reduced when compared with prior arrangements. It is not necessary that it is more than 0.3-0.5 mm
Moreover, the risk that the silencer will radiate disturbing resonant vibrations is significantly reduced.
The greatest stability of the silencer is achieved when a compressing strain constantly acts between the casing and the ceramic element and hence shrinkage and/or press fits are preferred.
Advantageously the element and the casing are both of cylindrical form, the cylindrical casing having sheet metal end walls.
The invention also relates to a method of manufacturing an exhaust silencer as described above which comprises providing at least one porous ceramic element with a cylindrical outer surface having a diameter which at a first low temperature is at least equal to the diameter of a cylindrical inner wall of a casing of sheet metal, heating the casing to such a high temperature that it is expanded and then inserting the element into the casing, whereby the casing shrinks into firm contact with the element when the temperature of the casing is decreased to the first low temperature again.
Preferably the method comprises the step of inserting the element into the heated casing when the inner diameter of the casing exceeds the outer diameter of the element.
Advantageously the diameter of the outer surface of the element is greater than the diameter of the cylindrical inner wall at said low temperature, and the method includes the step of inserting the element into the casing as a friction fit at said high temperature.
In order that the invention may be more readily understood, and so that further features thereof may be appreciated, the invention will now be described by way of example with reference to the accompanying drawings, in which:
Figure 1 is a partially cut-away view of a silencer according to the invention, and
Figure 2 is a partially, cut-away view of a further silencer according to the invention.
Fig. 1 illustrates, in perspective, a silencer according to the invention and shows a casing 1 (which is partially cut-away) made, preferably, of stainless sheet metal. The casing is of circular-cylindrical configuration and thickness of the sheet metal in the illustrated embodiment is about 0.5 mm. At the open ends of the casing 1, transverse walls 2 and 3 are connected to the casing. Exhaust pipe stubs 4 and 5 extend from the transverse walls 2 and 3. The walls are preferably made of a thicker sheet metal than the cylindrical part of the casing and are welded to the casing 1. Inside the casing 1 a ceramic body 6 having a circular-cylindrical outer surface is located.
The ceramic body 6, which forms a soundabsorbing element, is provided with a central through-going channel 7 for the exhaust gases. The ceramic body 6 comprises a foamed ceramic material and has been moulded in a mould for obtaining a high accuracy to size and, the outer cylindrical surface of the element is preferably ground to the desired dimensions, in order to obtain optimum abutment against the inner wall of the casing 1.
The ceramic body, which is highly porous and has a compression strength of at least 40 kN/m2 and preferably at least 300 kN/m2, has an outer diameter which, at room temperature, exceeds the inner diameter of the casing 1. In assembling the silencer the casing 1 is therefore heated to a temperature, for example 400-600"C, sufficiently high to enable the ceramic body 6 to be pressed as a friction fit into the casing 1, said ceramic being held, for example, at room temperature. As the casing cools it contracts, and consequently the casing becomes very firmly bonded to the ceramic body.
During the above described assembly process the casing 1 is preferably brought to a temperature corresponding to a calculated highest operation temperature of the silencer.
Of course, the casing may be heated to much higher temperature than those mentioned, when it is desired to obtain very high bonding forces betwee the inner wall of the casing 1 and the outer surface of the ceramic body 6.
As has been mentioned above when the ceramic body 6 has been placed in a desired position in the heated casing 1, the casing is allowed to cool and thus to shrink onto the body 6. The end walls 2 and 3 are then welded firmly to the casing. The resultant unit, comprising the casing 1 and the body 6, is particularly rigid, which prevents the casing from generating oscillations or vibrations in use of the silencer and, as mentioned before, the casing can also be made very thin. The above mentioned temperatures have only been selected by way of example and may vary in dependence on the co-efficient of expansion of the sheet metal and the ceramicmaterial respectively, or in dependence on the temperature of the ceramic when the body 6 is pressed into the casing 1.The described process where the ceramic element is pressed into the heated casing, creating a combined shrinkage and press fit, may naturally be replaced with a pure shrinkage fit, in which the casing 1 is heated and caused to expand to an extent such that the ceramic body 6 can be inserted into the casing without requiring the exertion of any appreciable force. Alternatively, the described process may be replaced by a process in which the ceramic element is pressed into the casing without prior heating thereof. In such a process the ceramic body will be a tight friction fit within the casing.
Irrespective of the method used, one important criterion is that there is obtained such a joint or bonding between the casing and the ceramic body which is such that the forces between the cylindrical outer surface of the ceramic body 6 and inner wall of the casing 1 remain sufficiently large even at maximum operation temperatures, e.g. operational temperatures of 600'C.
Fig. 2 illustrates a silencer comprising a plurality of ceramic elements, for example elements 8, 9 and 10, all of which are a shrinkage fit in the metal casing 1.
Each cylindrical element 6, 8, 9 and 10 is ground to an outer diameter which, at low temperatures (by which is meant here normal room temperature, i.e. about 20 C), exceeds the inner diameter of the casing 1 at the same temperature. In certain cases, the cylindrical elements can be moulded to such precise dimensions as to obviate the need of separately working the outer surfaces of said element.
The shrinkage and/or press fits described above can be replaced with an adhesive joint, where a continuous thin layer of adhesive is applied to the entire outer cylindrical surface of the ceramic element. The element will have a. diameter so adapted to the inner diameter of the casing that at least some force is required to press the element into the casing. Any suitable temperature resistant adhesive agent can be used, such as an aluminium phopshate binder, for example.
The invention is not limited to the embodiments shown, since these can be modified in different ways within the scope of the present invention. Thus, it is not necessary to have a -cylindrical casing, since a casing with
It has been found that a silencer in accordance with the invention may have good -acoustic and mechanical properties, and the ceramic element is preferably able to absorb compression strains exerted on the silencer.
Claims (11)
1. An exhaust silencer comprising a casing of sheet metal, and at least one soundabsorbing porous ceramic element with at least one through-going channel for the exhaust gases, the ceramic element being lo cated in said casing and having an outer surface firmly connected to a corresponding wall of the casing which embraces the ceramic element, the casing and the ceramic ele ment together forming a rigid construction.
2. An exhaust silencer according to claim 1, wherein the casing is heat shrunk onto the ceramic element.
3. An exhaust silencer according to claim 1, wherein the casing is a friction fit onto the ceramic element.
4. An exhaust silencer according to claim 1, wherein the casing is connected to the ceramic element by means of an adhesive layer between the ceramic element and the inner wall of the casing.
5. An exhaust silencer according to any one of the preceding claims wherein the element and the casing are both of cylindrical form, the cylindrical casing having sheet metal end walls.
6. A method of manufacturing an exhaust silencer according to any one of the preceding claims, which comprises providing at least one porous ceramic element with a cylindrical outer surface having a diameter which at a first low temperature is at least equal to the diameter of a cylindrical inner wall of a casing of sheet metal, heating the casing to such a high temperature that it is expanded and then inserting the element into the casing, whereby the casing shrinks into firm contact with the element when the temperature of the casing is decreased to the first low temperature again.
7. A method according to claim 6, which comprises the step of the element into the heated casing when the inner diameter of the casing exceeds the outer diameter of the ele ment
8. A method according to claim 6, wheren the diameter of the outer surface of the element is greater than the diameter of the cylindrical inner wall at said low temperature, the method including the step of inserting the element into the casing as a friction fit at said high temperature.
9. An exhaust silencer substantially as herein described with reference to and as shown in Fig. 1 of the accompanying drawings.
1 0. An exhaust silencer substantially as herein described with reference to and as shown in Fig. 2 of the accompanying drawings.
11. A method of making a silencer substantially as herein described with reference to the accompanying drawings.
1 2. Any novel feature or combination of features disclosed herein.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| SE8106062 | 1981-10-13 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB2108200A true GB2108200A (en) | 1983-05-11 |
| GB2108200B GB2108200B (en) | 1985-01-16 |
Family
ID=20344780
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB08229072A Expired GB2108200B (en) | 1981-10-13 | 1982-10-12 | Exhaust gas silencer with porous ceramic sound-absorbing material |
Country Status (9)
| Country | Link |
|---|---|
| JP (1) | JPS5879614A (en) |
| BR (1) | BR8205958A (en) |
| CA (1) | CA1183460A (en) |
| DE (1) | DE3238010A1 (en) |
| ES (1) | ES8400793A1 (en) |
| FR (1) | FR2514414A1 (en) |
| GB (1) | GB2108200B (en) |
| IT (1) | IT1153227B (en) |
| SE (1) | SE8205687L (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1985000409A1 (en) * | 1983-07-13 | 1985-01-31 | Mogens Ba^Ekgaard Trading Aps | A silencer for internal combustion engines and a method for its manufacture |
| GB2273685A (en) * | 1992-11-13 | 1994-06-29 | Ajay Leisure Prod Inc | Structural foam golf cart with game computer. |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS62175217U (en) * | 1986-04-25 | 1987-11-07 | ||
| DE19756468C1 (en) * | 1997-12-18 | 1999-03-04 | Alois Ridder Gmbh & Co Kg | Eddy current noise insulator |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2072961A (en) * | 1934-03-01 | 1937-03-09 | Burgess Lab Inc C F | Silencer |
| US3105570A (en) * | 1962-04-17 | 1963-10-01 | Bezemes Nicholas | Internal combustion engine exhaust muffler |
| US3227241A (en) * | 1964-03-16 | 1966-01-04 | Corning Glass Works | Ceramic mufflers |
| US3568723A (en) * | 1967-06-23 | 1971-03-09 | Du Pont | Metal-ceramic composite structures |
-
1982
- 1982-10-06 SE SE8205687A patent/SE8205687L/en not_active Application Discontinuation
- 1982-10-11 ES ES516419A patent/ES8400793A1/en not_active Expired
- 1982-10-12 FR FR8217068A patent/FR2514414A1/en active Pending
- 1982-10-12 JP JP57179696A patent/JPS5879614A/en active Pending
- 1982-10-12 IT IT23716/82A patent/IT1153227B/en active
- 1982-10-12 GB GB08229072A patent/GB2108200B/en not_active Expired
- 1982-10-12 CA CA000413216A patent/CA1183460A/en not_active Expired
- 1982-10-13 BR BR8205958A patent/BR8205958A/en unknown
- 1982-10-13 DE DE19823238010 patent/DE3238010A1/en not_active Withdrawn
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1985000409A1 (en) * | 1983-07-13 | 1985-01-31 | Mogens Ba^Ekgaard Trading Aps | A silencer for internal combustion engines and a method for its manufacture |
| GB2273685A (en) * | 1992-11-13 | 1994-06-29 | Ajay Leisure Prod Inc | Structural foam golf cart with game computer. |
Also Published As
| Publication number | Publication date |
|---|---|
| CA1183460A (en) | 1985-03-05 |
| SE8205687D0 (en) | 1982-10-06 |
| IT1153227B (en) | 1987-01-14 |
| GB2108200B (en) | 1985-01-16 |
| FR2514414A1 (en) | 1983-04-15 |
| BR8205958A (en) | 1983-09-13 |
| IT8223716A0 (en) | 1982-10-12 |
| DE3238010A1 (en) | 1983-04-21 |
| SE8205687L (en) | 1983-04-14 |
| ES516419A0 (en) | 1983-11-01 |
| ES8400793A1 (en) | 1983-11-01 |
| JPS5879614A (en) | 1983-05-13 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4911972A (en) | Insulating composite gasket | |
| US7214253B2 (en) | Filtering body comprising a plurality of filtering units, in particular designed for a particulate filter | |
| KR100414137B1 (en) | Honeycomb arrangement with an intermediate layer containing at least one metal foil | |
| KR20030015376A (en) | Method of assembling a catalytic converter | |
| JPH0428887B2 (en) | ||
| JPS60111011A (en) | Manufacture of silencer | |
| GB2108200A (en) | Exhaust gas silencer with porous ceramic sound-absorbing material | |
| US6647715B2 (en) | Heat shield for an exhaust system of an internal combustion engine | |
| KR0150792B1 (en) | Intumescent conforming mounting pad | |
| US4838235A (en) | Heat-insulating engine structure and method of manufacturing the same | |
| JPH072971Y2 (en) | Silencer | |
| JP2002081317A (en) | Laminated heat insulating plate and manufacturing method | |
| KR20010005491A (en) | Improvements in catalytic reactors | |
| EP0599305A1 (en) | Multi-shell formed piece and device and process for disposing flexible insulating plates between the walls of said formed piece | |
| JP2807465B2 (en) | Ceramic heat-resistant composite parts | |
| JPH0625633Y2 (en) | Muffler for exhaust system of internal combustion engine | |
| JPH07204759A (en) | Double pipe containing expanded graphite sheet and its production | |
| EP0407765B1 (en) | Head gasket with sealing rings having multi-stage compressibility | |
| JPH037535Y2 (en) | ||
| JPH0261493A (en) | Highly heat resistant roll | |
| JPS6044506B2 (en) | Internal combustion engine cylinder liner | |
| JP2511518Y2 (en) | Exhaust pipe outer plate member | |
| JP2562096Y2 (en) | Exhaust pipe fitting | |
| JP2921189B2 (en) | Insulated piston | |
| JPS603433A (en) | Anchor device for fireproof and heat insulating material layer |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PCNP | Patent ceased through non-payment of renewal fee |