CN2591231Y

CN2591231Y - Powder metallurgical composite material engine air valve guide cylinder

Info

Publication number: CN2591231Y
Application number: CN 01255987
Authority: CN
Inventors: 李元元; 肖志瑜; 夏伟; 龙雁; 吴苑标
Original assignee: South China University of Technology SCUT
Current assignee: South China University of Technology SCUT
Priority date: 2001-09-28
Filing date: 2001-09-28
Publication date: 2003-12-10
Anticipated expiration: 2011-09-28

Abstract

The utility model relates to a powder metallurgical composite material engine air valve guide cylinder. The upper surface layer at the top of a cylinder body is composed of materials B. The cylinder body is composed of materials A. The materials A are provided with components and mass percent contents as follows Cu 0.5-2%, Ni 1-3%, Mo 0.5-1%, C 0.5-1%, NbC 5-12% and P 0.3-0.6%. The rest is Fe and the inevitable trace of impurities. The materials B are provided with components and mass percent contents as follows Cu 2-4%, Ni 2-4%, Mo 1-2%, C 0.5-1.5%, NbC 10-20% and P 0.3-0.6%. The rest is Fe and the inevitable trace of impurities. The air valve guide cylinder of the utility model has the advantages of high intensity, high hardness and abrasive resistance.

Description

Composite powder metallurgy material engine valve guide

Technical field

The utility model relates to the composite powder metallurgy material engine valve guide made from composite powder metallurgy material.

Background technique

Existing engine valve guide part normally adopts the wrought alloy steel, form through working procedure processing such as machining, heat treatments as (12CrNi3A steel etc.), low, the complex process of stock utilization, valve guide part in use, serious wear, valve guide top is also worn out by cam sometimes, make normally opening and closing of valve, had a strong impact on the performance of motor, to powerful motor, situation is more serious.

Summary of the invention

The purpose of this utility model is to adopt means of a powder metallurgy technique, overcomes the problem that exists in existing valve guide manufacturing and the using process, and the material design is combined with powder metallurgical technique, and a kind of wear-resisting composite powder metallurgy material engine valve guide is provided.

Composite powder metallurgy material engine valve guide of the present utility model is made of cylindrical shell and the top layer above the cylindrical shell top, and the top layer above the cylindrical shell top is made of material B, and cylindrical shell is made of materials A; The component and the mass percentage content thereof of described materials A are as follows: Cu 0.5-2%, Ni 1-3%, Mo 0.5-1%, C 0.5-1%, NbC 5-12%, P 0.3-0.6%, and all the other are iron and inevitable microimpurity; The component and the mass percentage content thereof of described material B are as follows: Cu 2-4%, Ni 2-4%, Mo 1-2%, C 0.5-1.5%, NbC10-20%, P 0.3-0.6%, all the other are iron and inevitable microimpurity.

When the skin depth above the described composite powder metallurgy material engine valve guide top that is made of material B is the 1-2 millimeter, can reach best intensity and wear-resisting effect.

The preparation method of composite powder metallurgy material engine valve guide comprises:

---press table 1 and be equipped with dusty material A:

Table 1

Grain diameter of components mass percent consumption

Iron powder≤147 75-86%

Copper powder≤74 0.5-2%

Nickel powder 2-5 1-3%

Molybdenum powder≤74 0.5-1%

Plumbago≤74 0.5-1%

Ferrophosphorus or phosphor-copper powder≤74 2-5%

Niobium carbide powder 2.5 5-12%

The cured powder of Acker≤38 0.5-0.8% press table 2 and are equipped with dusty material B:

Table 2

Grain diameter of components mass percent consumption

Iron powder≤147 65-78%

Copper powder≤74 2-4%

Nickel powder 2-5 2-4%

Molybdenum powder≤74 1-2%

Plumbago≤74 0.5-1.5%

Ferrophosphorus or phosphor-copper powder≤74 2-5%

Niobium carbide powder 2-5 10-20%

The cured powder of Acker≤38 0.5-0.8%

---above-mentioned dusty material is crossed 100 mesh sieves, does on two-dimentional batch mixer then and mixes 30-80 minute;

---with dusty material A filling in valve guide cavity impression, the top layer cloth dusty material B on valve guide top then, under 130 ℃-150 ℃ with the pressure warm-pressing formation of 550-700MPa;

---with valve guide green compact sintering on four sections high temperature sintering furnaces of compound molding, place downwards at valve guide top, 1-2 hour high temperature sintering time, push away 20-25 minute/boat of boat speed, and the temperature of each section of sintering furnace is set by table 3.

Table 3

Sintering I section sintering II section sintering III section sintering IV section

300-400℃ 700-800℃ 1250-1300℃ 650-800℃

Promptly obtain the valve guide of composite powder metallurgy material, its top hardness HRC55-63, remaining part hardness HRC25-45, б _b=800-900MPa, δ=2.0-3.0%.

The utility model compared with prior art has following advantage:

1, valve guide part of the present utility model has guaranteed that the existing high intensity of valve guide has high hardness and wear resistance again, can replace conventional alloy steel material fully;

2, the composite powder metallurgy material valve guide that provides of the utility model, through 500 hours stand certification tests, its top wearing and tearing approached zero, and wear resistance improves 50-100 doubly than 12CrNi3A steel.

Description of drawings

Fig. 1 is the structural representation of composite powder metallurgy material engine valve guide of the present utility model.

Fig. 2 is another structural representation of composite powder metallurgy material engine valve guide of the present utility model.

The invention will be further described below by following embodiment.

Embodiment

As shown in Figure 1, top layer above the composite powder metallurgy material engine valve guide of the present invention top 1 is made of materials A, and cylindrical shell 2 is made of material B.As shown in Figure 2, top layer above the composite powder metallurgy material engine valve guide of the present invention top 11 (1) is made of materials A, and cylindrical shell 2 ' is made of material B.

Claims

1, a kind of composite powder metallurgy material engine valve guide is characterized in that the top layer above the cylindrical shell top is made of material B, and cylindrical shell is made of materials A; The component and the mass percentage content thereof of described materials A are as follows: Cu 0.5-2%, Ni 1-3%, Mo 0.5-1%, C 0.5-1%, NbC 5-12%, P 0.3-0.6%, and all the other are iron and inevitable microimpurity; The component and the mass percentage content thereof of described material B are as follows: Cu 2-4%, Ni 2-4%, Mo 1-2%, C 0.5-1.5%, NbC 10-20%, P 0.3-0.6%, all the other are iron and inevitable microimpurity.

2, composite powder metallurgy material engine valve guide according to claim 1 is characterized in that the skin depth above the described composite powder metallurgy material engine valve guide top that is made of material B is the 1-2 millimeter.