JPS59131749A - Piston for internal combustion engine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a composite piston for an internal combustion engine of the type that includes a crown and a skirt.

One function of the crown is to form one boundary of the combustion chamber, so the crown material must be able to withstand high temperatures. To this end, the crown is usually formed from a metallic material having the required heat resistance. One function of the skirt is to guide the piston in reciprocating motion, thereby reducing engine losses. The skirt material should have as low a coefficient of friction as possible and add as little weight as possible to the weight of the piston. in general,
Although suitable metallic materials for forming the piston crown are those that have an acceptable coefficient of friction and are light in weight, there are some other materials that have improved properties in this respect, e.g. Silastic materials also exist. In general, it has not been possible to use plastic materials until now, since they were not able to withstand the elevated temperatures encountered during operation.

According to the invention, a piston for an internal combustion engine is obtained which comprises a crown of metallic material and a skirt separated from the crown by a heat-insulating layer, the skirt having an external skirt surface of plastic material.

Next, the present invention will be explained in more detail by some embodiments.

Referring first to FIG. 1, this piston is suitable for gasoline or diesel engines and consists of a crown, an O and a skirt 11. The crown] 0 can be formed from a metallic material, for example aluminum or an aluminum alloy, by casting, for example die casting, and can have the characteristics of 1j.

If the piston is for a diesel engine, the combustion bowl can be reinforced around its inlet by a reinforcing material charged during casting. The crown 1o has three piston ring grooves 12 formed therein, which can also be reinforced by a wear-resistant material charged into the crown during casting. The two noteno ξ-cross head bosses 13 extend from the lower surface of the crown 10 to the inner curved surface (t]11 on the outside thereof.
(c) It hangs down in the radial direction. The pin 13 has an alignment crosshead pin hole 14 for accommodating the rad pin 15 in the cross.

In one embodiment, not shown, Zes1
3 can be parallel.

Skirt 11 is formed from a silastic material to the extent that it provides a plastic skirt surface for contacting the mating cylinders or liners. A pair of opposed crosshead pin holes 16 are provided as shown, and the skirt 11 is provided with a pair of crosshead pins 16 of the crown 10, l?
Compatible across 13 stages. In this position the skirt cross head pin hole 16 is aligned with the crown cross head pin hole 1+, so the cross head lδ pin 15 is aligned with the crown cross head pin hole 1+.
The crown 10 can be joined to the skirt 11 in a composite manner through a total of four holes 14,16. A resilient lock washer 17 positions and holds the seat pin 15 to the cross. Therefore, there is a thermal barrier formed by the air gap between the crown 10 and the skirt 11, which limits the heat transfer from the crown 10 to the skirt 11.

This reduces the temperature of the skirt 11 and allows this skirt to be made of a heat-resistant plastic material, such as polyetheretherketone, polyetherketone, a plastic alloy of aromatic polyetherketone and polyarylene sulphide (UK Patent Application No. 8131821). ), poly-ξ-hydroxybenzoic acid or cyIJ:lI-
7 modified polyester or polyetherimide or
l? IJIMI-P, which has the necessary strength and ability to form an effective lubricant film, makes it possible to manufacture it from all other less heat-resistant plastic materials, such as polytetrafluoroethylene or nylon. do. Plastic materials may be reinforced with glass, metal, organic or metal oxide fibers or wire. Skirt 11 may be formed by extrusion or injection molding, or by pressing and curing plastic powder, or by spraying, or by any other suitable plastic molding method.

When using a silastic alloy, it is made of polyetherketone and polyphenylene sulfide.
It can be formed with a weight ratio of 5 to 5:95. This alloy has adequate fatigue strength for the piston skirt and also has the property of forming an effective lubricant film on its surface, so that the skirt 11 will also have adequate lubrication properties in use. Show your sex. This alloy can be produced by solvent compounding using benzyl benzoate as the solvent or by melt compounding. This is described in British Patent Application No. 8131821.

Referring now to FIG. 2, common parts between this figure and FIG. 1 are designated with the same reference numerals and will not be described in detail. In the case of the FIG. 2 variant, the skirt 11 is formed from two parts: aluminum or aluminum alloy surrounded by a generally cylindrical sleeve 11-b of plastic material as described in FIG. The support 11ao of a metal material such as the sleeve 11b tt therefore forms the skirt surface.The skirt crosshead pin JL16 is
The elastic stop washer 17 passes through the support 11a and the sleeve llb and is fitted into the metal support 11a.

Sleeve lb can be formed by any of the methods described in FIG.

This variant embodiment has the advantage of creating stiffness for the metal support 11aIJ''-skirt 11 as well as aiding in heat transfer downward from the seat pins 15 to the cross.Additionally, the metal support 11a , can be better than the plastic material of the IJ-bulb to support the loads applied by the cross-height pin 15 during use.

Referring now to FIG. 3, a second shape of the piston is suitable for use in diesel engines and consists of a crown 20 and a skirt 21.

The crown 20 has an upper plate of ferrous material such as stainless steel, forming a fuel bowl 23. A U-shaped cross-section ring 24 (also made of ferrous material such as stainless steel) has a The lower surface of the ring 24 is welded or brazed around the periphery of the lower surface of the upper plate 22. Furthermore, the lower surface of the ring 24 is a lower member having the same area as the upper plate 22 and made of a metal material such as aluminum or aluminum alloy. 25, welded or soldered, or diffusion bonded. (
A deposited annular disc or washer 27, roughened by oxidation (to reduce heat transfer between the deposited annular disc or washer), is placed below the combustion chamber 23 between the plate 22 and the bottom member 250. ing.

Therefore, the main sealed chamber 28 is formed between the plate 22 and the lower member 25, and the split cloth closed chamber 29 is formed between the ring 24 and the upper plate 25.
It is formed between 20 and 20.

These chambers may contain air or may contain a vacuum and/or an insulating material (not shown). Therefore, a heat insulating layer is provided between the upper plate 22 and the lower member 250.

The lower member 25 forms both a portion of the crown and a support portion 32 of the skirt 21 in one piece.

This support part 32 has on its outer surface a sleeve of all the plastic materials described in FIG. It has 33. Sleeve 33
forms the skirt surface and is manufactured by all the methods described in FIG.

Three piston ring grooves 30 and a cross head pin hole 31 are formed in the lower member 25, and this cross head pin hole also passes through the sleeve 33.

Referring now to FIG. 4, common parts between this figure and FIG. 3 are designated with the same reference numerals and will not be described in detail. In this variant, an additional insulation layer 26 is provided between the chamber 28 , 29 and the lower part 250 . This is a porous metal material,
The material supported at the upper end of the lower member 25 may take the form of, for example, a metal mesh wire or mesh tape or a three-dimensional mesh, or may be in the form of a material sold under the trademark "RETIMET". Go ahead and take it. This can be achieved by placing the porous metal material in a mold and then casting the bottom member around it, with the metal only partially penetrating the porous metal material. The casting method is die casting (5queeze casting).
) can be law.

In this case, the lower surface of the ring 24 is again welded, brazed or diffusion bonded to the porous metal material.

The plastic material of the skirt mentioned above in the drawing is amane (
It is appreciated that the same materials are not required. for example,
The crown end of the skirt may be manufactured from a heat resistant plastic material, unlike the crown of a plastic material which is less heat resistant.

The skirt extends around the entire circumference of the piston.

There is no compulsion, and it can only partially extend the circumference or be formed in sections. The plastic material and the support, if provided, can be joined together, and this joining can be carried out by any suitable method. This bonding can be carried out using a metal support in the form of a sheet by bending the formed laminate material to create a skirt. The skirt can be joined to the crown in any one of the ways described above in one drawing. The crown and support are
It can be formed in one piece and the silastic material can be bonded to the support during subsequent processing.

[Brief explanation of drawings]

1 shows a schematic side view, partially in section, of a first configuration of a piston for an internal combustion engine according to the invention; FIG. 2 is a similar schematic view showing a variant of FIG. 1; 4 is a schematic cross-sectional view of a second configuration of a piston for an internal combustion engine according to the invention, and FIG. 4 is a similar schematic view showing a modification of FIG. 3; 10.20... Crown, 1.1.2 Toscato, ll
a...Metal support, llb...Plastic part, 1
4.16...Crosshead pin hole, 15...Crosshead pin hole blocking layer, 28--Engraving of closed room drawing (no change in content) FtGJ. F/G, 4゜Procedural Amendment (Method) February 1980 No. 3B Dear Commissioner of the Japan Patent Office 1゜Things 1゛f) 'Jk r 1988 Patent Application No. 1
No. 95362 2 Title of invention Piston for internal combustion engine 3 Relationship with the case of the person making the amendment Patent applicant name NIBC 4, Agent January 31, 1980 (Delivery date) 6 Subject of amendment ( 11 Column for patent applicant representative in application form

Claims (1)

[Scope of Claims] 1. A piston for an internal combustion engine of the type consisting of a crown and a skirt depending from the crown, comprising a crown (10; 20) of metallic material and a scar (11; 21) separated from the crown by a heat insulating layer. It becomes more,
Piston for an internal combustion engine, characterized in that this skirt has an outer surface of plastics material. 2. The plastic material is polyetheretherketone, polyetherketone, a plastic alloy of aromatic polyetherketone and polyarylene sulfide, polynola-hydroxybenzoic acid, silicone-modified polyester, polyetheramide, or polyimide 1. , the piston according to claim 1. 3. The piston according to claim 1 or 2, wherein the plastic material is glass or metal, or organic or metal oxide fiber or wire. 4. Piston according to claim 1, wherein the skirt comprises a metal support (ll&) having a plastic member (llb) forming a plastic skirt surface on its outer surface. 5. Piston according to claim 4, wherein the plastic member (llb) is formed as a generally cylindrical stub extending around the outer surface of the metal support. 6. The piston is a composite piston with a skirt (11) and a separately formed crown (10), the crown and the skirt being joined by a cross rad pin (15) between them and with insulation between them. Piston according to any one of claims 1 to 5, characterized in that it features corresponding cross-socket holes (14, 16) for forming an air gap producing a layer. 7. Piston according to any one of claims 1 to 6, wherein the air barrier layer consists of a closed chamber (28) provided in the crown (20). 8. Piston according to claim 7, wherein the chamber (28) has a vacuum. 9. The crown (20) consists of an upper plate (22) joined to a portion of the crown around its periphery, which upper plate connects the portion of the crown to its periphery to form a chamber (28). Piston according to claim 7 or 8, having a constant distance on the inside. 10. The further barrier layer (26) is provided by a layer of insulating material extending over the surface of the part of the crown demarcating the chamber.
The piston according to any one of item 9. 11. Claim 1, wherein the insulating material (26) consists of a porous metallic material contained in the crown (20).
The piston described in item 0.