JPS5849663A - Engine part - 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] TECHNICAL FIELD This invention relates to improvements in engine components.

Although metal is in practical use for engine parts, various attempts have been made to make engine parts ceramic with the aim of achieving even higher efficiency.

3- However, there is no established standard as to which materials should be applied to which parts.

The present inventor made efforts to investigate this problem and found that a zirconia-based sintered body containing calcia as a solid solution can be applied to a wide range of engine parts.

The details will be described below.

A zirconia-based sintered body containing calcia as a solid solution is closer to metal than many other ceramic materials in terms of thermal expansion coefficient, and is a sintered body that expands approximately in proportion to temperature between 25°C and 1300°C. It is possible to form
Its coefficient of thermal expansion is closer to that of metal materials than that of many other ceramic materials. Unlike ceramics, there are fewer problems such as destruction due to thermal causes.

In addition, the thermal conductivity of the zirconia-based sintered body containing calcia as a solid solution can be set to 1 to 5 W/m・℃, so
It is possible to achieve good heat insulation properties for engine parts, which is suitable for improving fuel efficiency.

In addition, the crystal structure of the zirconia-based sintered body containing calcia as a solid solution can be a two-phase structure of tetragonal and cubic crystals. Since the transformation caused by C does not occur, it can be used with confidence.

Further, the strength of the zirconia-based sintered body containing calcia as a solid solution can be set to 200 to 1000 MPa, and the strength required for engine parts can be maintained.

In addition, the zirconia-based sintered body containing lucia as a solid solution has excellent wear resistance when used with steel materials and has a specific wear fit of 1 with oil lubrication.
X 10-6mm'//ko f-111m or less-
Since BQ constant curvature (!:) is possible, when used as an engine part, for example, in the tappet 1~, there will be no deviation in valve opening/closing timing even after long-term use.

Also, since it does not react with metal, it can withstand sliding for a long period of time.

In addition, the zirconia-based sintered body containing calcia as a solid solution has little strength deterioration even if it is processed to a relatively large surface roughness without repeatedly processing small surface roughness like many other ceramics. . For this reason, processing can be done quickly (
It is more advantageous than ceramics, which are widely used in industrial production, because any shape can be obtained quickly.For example, it is possible to process diamond A7 diamond, servant machining, ultrasonic machining, Lehner machining, etc. be.

In addition, zirconia-based sintered bodies containing calcia as a solid solution can be set to a mechanical impact resistance value superior to that of alumina ceramics, and can withstand harsh conditions such as engine parts compared to many other ceramics. Suitable for the parts to be used.

In addition, zirconia-based sintered bodies are often strengthened by aging treatment, but if calcia is dissolved in solid solution, it can be strengthened by aging treatment or only by firing, and it is often used in engine parts. The material is preferable because aging treatment does not cause defects in material quality such as heterogeneous precipitation due to deformation and heterogeneous heat treatment, and additional processes such as aging treatment are not required.

The thermal shock resistance U of a zirconia-based sintered body containing calcia as a solid solution can be set at a critical thermal shock temperature difference (ΔTO) of 250 to 500°C. It is preferable in that it does not cause any inconvenience even when used for parts with large slopes.

The Young's modulus of the zirconia-based sintered body containing jJ Lucia as a solid solution is small, and can be set to, for example, 150 to 250 GPa. Therefore, as an engine part, it is close to the Young's modulus of metal, and has good consistency with adjacent metal parts. This is preferable in this respect.

The firing surface of the zirconia-based sintered body containing calcia as a solid solution is smoother than that of many other ceramics, and for example, the surface can be said to have a surface roughness of 108 or less after firing, and unnecessary surface processing can be reduced.

Zirconia-based sintered bodies containing calcia in solid solution have excellent oxidation resistance because they are oxides, and are preferred as engine parts.

The crystal grain size of the zirconia-based sintered body containing calcia as a solid solution is set to 5 μm or less, and peeling of crystal grains is less likely to occur due to rubbing. In the case of engine parts, this has the advantage of preventing a decrease in efficiency due to a timing shift due to wear and an increase in clearance due to abrasion.

The porosity of the zirconia-based sintered body containing calcia as a solid solution is 10.
% or less, which is preferable in that when it is used as an engine part, for example, sliding against metal, abrasion powder enters into the pores and prevents an increase in the coefficient of friction.

The growth rate of the zirconia-based sintered body containing jylucia as a solid solution is 5.
It can be set to 3 to 6.1 It is advantageous in that it can be done.

The friction coefficient of the zirconia-based sintered body containing calcia as a solid solution can be set to 0.7 or less when used with steel materials, which is excellent in that it can reduce energy loss due to friction and improve fuel efficiency. There are 8-ru.

The zirconia-based sintered body containing calcia as a solid solution is chemically stable, so it is easy to remove and does not impose any restrictions on the assembly of engine parts.

The zirconia-based sintered body containing calcia in solid solution +, Jl, which constitutes engine parts having the above advantageous points, preferably has a calcia solid solution amount of 1 to 10 mol%, and preferably 3 to 5 mol% of shrimp. Good results are obtained when .

In addition to the case in which the entire engine part is composed of a zirconia-based sintered body containing calcia as a solid solution, there are cases in which the zirconia-based sintered body containing calcia as a solid solution is coated with a spray coating, or Good results can also be obtained when the adhesive is attached.

The engine parts of the present invention can be manufactured as follows! Ill-built vines.

By preparing zirconia powder containing a predetermined amount of calcium compound and molding it into a predetermined shape, cholera
400'C to about 1700'C (#3 is also preferably about 16
A zirconia-based sintered body containing calci 7 as a solid solution is produced by τ firing at a temperature of around 00°C.Then, if necessary, it is processed into a predetermined shape by various processing methods such as diamond cutting or laser processing. List the desired Tamazine parts.

Examples of engine parts of the present invention include cylinders, cylinder liners, pistons, piston heads, intake valves, exhaust valves, combustion chamber subchambers, cams, tappets, fuel injection pumps, bearings, thrusters, and the like.

As described above, the engine parts of the present invention have various advantages and greatly contribute to improving parts life.

Proxy lawyer Kensuke Norichika (and 1 other person) -11-

Claims (1)

[Claims] 1. An engine part made of a zirconia-based sintered body containing calcia as a solid solution. 2. The engine component according to claim 1, wherein the amount of calcia solid solution is 1 to 10 mol%. 3. The engine component according to claim 1, wherein the amount of calcia solid solution is 3 to 5 mol%. 4. The thermal expansion coefficient of the zirconia-based sintered body containing calcia as a solid solution is 8 to 13X10', and the temperature range is from 25°C to 1300°C.
2. The engine component according to claim 1, which is a sintered body that expands and accommodates the engine component in a manner substantially proportional to the temperature. 5. Claim 1, wherein the crystal structure of the zirconia-based sintered body containing calcia as a solid solution is a two-phase structure of tetragonal and cubic crystals.
Engine parts listed in section. 6. The engine component according to claim 1, wherein the zirconia-based sintered body containing calcia as a solid solution has a thermal conductivity of 1 to 5 W/m.degree. 7. The engine component according to claim 1, wherein the zirconia-based sintered body containing calcia as a solid solution has a bending strength of 200 to 1000 MPa. 8. The wear resistance of the zirconia-based sintered body containing calcia as a solid solution was determined by a wear test under oil lubrication using steel as the counterpart material.
The engine component according to claim 1, wherein the engine component is not more than X10 mm - kB-n+m. 9. The engine part according to claim 1, wherein the zirconia-based sintered body containing calcia as a solid solution has been subjected to surface roughness of 5S or less. 10. The zirconia-based sintered body containing calcia as a solid solution The engine component according to claim 1, wherein the mechanical impact resistance of the compact is superior to that of the alumina ceramic sintered compact. 11. The zirconia-based sintered compact containing calcia as a solid solution is aged. Claim 1, which is a sintered body fired without
Engine parts listed in section. 12. Thermal shock resistance of the zirconia-based sintered body containing calcia as a solid solution is 250 to 500°C at the critical thermal shock temperature difference (ΔTc>
An engine component according to claim 1. 13. Claim 1: The Young's modulus of the zirconia-based sintered body containing calcia as a solid solution is 150 to 2'50 GPa.
Engine parts listed in section. 14. The engine component according to claim 1, wherein the surface smoothness of the zirconia-based sintered body containing calcia as a solid solution is 108 or less in terms of surface roughness. 15. The engine component according to claim 1, wherein the crystal grain size of the zirconia-based sintered body containing calcia as a solid solution is 5 μm or less. 16. The engine component according to claim 1, wherein the zirconia-based sintered body containing calcia as a solid solution has a porosity of 10% or less. 17. The engine component according to claim 1, wherein the zirconia-based sintered body containing calcia as a solid solution has a density of 5.3 to 6.1 x'l'o" Ko /+++3r. 18. The engine part according to claim 1, wherein the molten zirconia-based sintered body has a porosity coefficient of 0.7 or less with respect to the steel material. 19. The engine part includes a cylinder, a cylinder liner, and a screw. , piston head, intake valve, exhaust valve, combustion chamber pre-chamber, cam, tappet, combustion [injection pump,
The engine component according to any one of claims 1 to 18, which is a bearing, a thrust rod, or other component. 20. The engine part according to claim 1, wherein the zirconia-based sintered body containing calcia as a solid solution forms a part of the engine part. 21. The engine component according to claim 20, wherein the zirconia-based sintered body containing calcia as a solid solution forms a part of the engine component. 22. The engine component according to claim 1, wherein the zirconia-based sintered body containing calcia as a solid solution forms a part of the engine component.