阅读说明：本技术 一种汽油机钢活塞及其制造方法 (Steel piston of gasoline engine and manufacturing method thereof ) 是由 林风华 石小明 刘世英 吴义民 马学军 曹国帅 郭伟 田维亮 李猛猛 张俊青 于 2019-11-29 设计创作，主要内容包括：本发明公开了汽油机钢活塞,包括钢活塞本体,钢活塞本体的上部内嵌有头部冷却腔、在靠近活塞销孔部位设有销孔冷却腔,头部冷却腔与销孔冷却腔连通,通过头部冷却腔来冷却活塞头部,通过销孔冷却腔来冷却销孔部位；钢活塞本体在发动机机体喷油嘴安装位置相对应处设有进油孔、在进油孔相对侧、活塞中心线位置处设有出油孔,进油孔与出油孔均与头部冷却腔连通,机油泵的喷油嘴通过管道连通,机油泵与发动机动力输出端连接,机油通过进油孔进入冷却油腔和销孔冷却腔,在头部冷却腔和销孔冷却腔吸收热量后的高温油从出油孔流出。本发明能够满足汽油机高爆压、高功率密度、高可靠性和耐久性的使用要求,解决了铸造铝硅合金高温疲劳强度不足的问题。(The invention discloses a steel piston of a gasoline engine, which comprises a steel piston body, wherein a head cooling cavity is embedded in the upper part of the steel piston body, a pin hole cooling cavity is arranged at the position close to a pin hole of the piston, the head cooling cavity is communicated with the pin hole cooling cavity, the head of the piston is cooled through the head cooling cavity, and the pin hole position is cooled through the pin hole cooling cavity; the engine oil pump is connected with the power output end of the engine, the engine oil enters the cooling oil cavity and the pin hole cooling cavity through the oil inlet hole, and high-temperature oil after absorbing heat in the head cooling cavity and the pin hole cooling cavity flows out of the oil outlet hole. The invention can meet the use requirements of high detonation pressure, high power density, high reliability and durability of the gasoline engine, and solves the problem of insufficient high-temperature fatigue strength of cast aluminum-silicon alloy.)

1. A gasoline engine steel piston comprises a steel piston body and is characterized in that a head cooling cavity is embedded in the upper portion of the steel piston body, a pin hole cooling cavity is arranged at a position close to a pin hole of the piston, the head cooling cavity is communicated with the pin hole cooling cavity, the head of the piston is cooled through the head cooling cavity, and the pin hole position is cooled through the pin hole cooling cavity; the engine oil pump is connected with the power output end of the engine, the engine oil enters the cooling oil cavity and the pin hole cooling cavity through the oil inlet hole, and high-temperature oil absorbing heat in the head cooling cavity and the pin hole cooling cavity flows out of the oil outlet hole.

2. The steel piston of gasoline engine as defined in claim 1, wherein the steel piston body is further provided with a lubricating oil supply hole near the inner side of the pin hole, the lubricating oil supply hole is matched with the oil outlet hole, and part of the high temperature oil flowing out from the oil outlet hole flows out through the lubricating oil supply hole.

3. The steel piston of the gasoline engine as claimed in claim 2, wherein the lubricating oil supply holes comprise a lubricating oil supply hole I, a lubricating oil supply hole II and a lubricating oil supply hole III, the lubricating oil supply hole I and the lubricating oil supply hole III are respectively positioned at two axial sides of the lubricating oil supply hole II, the lubricating oil supply hole I, the lubricating oil supply hole II and the lubricating oil supply hole III are respectively positioned at the axial middle position between the pin hole I at one side and the pin hole II at the other side, lubricating oil flows into the pin hole from the lubricating oil supply hole, flows into the pin hole at the other end from the lubricating oil supply hole, flows into the small end hole of the connecting rod from the lubricating oil supply hole, and flows into the small end hole of the connecting rod and the pin hole through the lubricating oil flowing out from the lubricating oil supply hole, so that lubricating oil compensation is performed on the pin hole and the small end hole of the connecting rod respectively.

4. The steel piston of the gasoline engine as claimed in claim 3, wherein the pin hole part is provided with a plurality of pin hole lubrication holes, the pin hole lubrication holes are respectively communicated with the head cooling cavity or the pin hole cooling cavity, and engine oil enters the pin hole from the head cooling cavity or the pin hole cooling cavity through the pin hole lubrication holes to replenish pin hole lubrication oil.

5. The steel piston of the gasoline engine as defined in claim 4, wherein the pin hole lubrication holes comprise a pin hole lubrication hole I, a pin hole lubrication hole II, a pin hole lubrication hole III, a pin hole lubrication hole IV, a pin hole lubrication hole V and a pin hole lubrication hole VI, and the pin hole lubrication hole I, the pin hole lubrication hole II and the pin hole lubrication hole III are respectively arranged symmetrically with the pin hole lubrication hole VI, the pin hole lubrication hole V and the pin hole lubrication hole IV with an axial vertical plane of the pin hole as a symmetrical plane.

6. The steel piston of the gasoline engine as claimed in claim 5, wherein the steel piston body comprises a piston core part and a piston ring part, the upper end face of the piston ring part is provided with an axial protrusion, the outer cylindrical surface of the axial protrusion is in sealing fit with the axial inner hole of the piston core part to form a vertical matching surface, the lower end face of the piston core part is in sealing fit with the upper end face of the piston ring part to form a horizontal matching surface, the piston core part is provided with one part of a head cooling cavity, the piston ring part is provided with the other part of the head cooling cavity and a pin hole cooling cavity, and the piston core part and the piston ring part are formed in a sealing connection mode through the.

7. The gasoline engine steel piston as claimed in claim 6, wherein the matching surfaces are connected by laser welding or electron beam welding.

8. The method for manufacturing a steel piston for a gasoline engine according to claim 6, comprising the steps of:

a) firstly, forging a piston core part blank and a piston ring part blank;

b) respectively processing a piston core part cooling cavity and a piston ring part cooling cavity according to the molding shape;

c) processing a piston pin hole cooling cavity by using a drilling machine;

d) then, a pin hole semi-finished product and a lubricating oil supply hole are machined;

e) machining a lubricating oil supply hole;

f) the piston core part and the piston ring part are connected into a whole by welding the vertical matching surface and the horizontal matching surface, and the piston core part cooling cavity and the piston ring part cooling cavity are combined into a head part cooling cavity;

g) and (3) processing piston pin holes by using a boring machine, and then processing a combustion chamber, an annular groove, an oil inlet hole and an oil outlet hole in sequence according to the structural size of the piston to finally form the complete piston.

Technical Field

The invention relates to the technical field of manufacturing of pistons of internal combustion engines, in particular to a steel piston of a gasoline engine and a manufacturing method thereof.

Background

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a novel gasoline engine steel piston and a manufacturing method thereof, the gasoline engine steel piston can meet the use requirements of high detonation pressure, high power density, high reliability and durability of a gasoline engine, and the problem of insufficient high-temperature fatigue strength of cast aluminum-silicon alloy is solved.

The technical scheme adopted by the invention for solving the technical problems is as follows:

a gasoline engine steel piston comprises a steel piston body, wherein a head cooling cavity is embedded in the upper part of the steel piston body, a pin hole cooling cavity is arranged at the position close to a piston pin hole, the head cooling cavity is communicated with the pin hole cooling cavity, the head of the piston is cooled through the head cooling cavity, and the pin hole position is cooled through the pin hole cooling cavity; the engine oil pump is connected with the power output end of the engine, the engine oil enters the cooling oil cavity and the pin hole cooling cavity through the oil inlet hole, and high-temperature oil absorbing heat in the head cooling cavity and the pin hole cooling cavity flows out of the oil outlet hole.

The steel piston body still is equipped with lubricating oil supply hole near pinhole inboard position, lubricating oil supply hole and oil outlet position cooperation, and the part high temperature oil that flows from the oil outlet flows through lubricating oil supply hole.

The lubricating oil supply holes comprise a lubricating oil supply hole I, a lubricating oil supply hole II and a lubricating oil supply hole III, the lubricating oil supply hole I and the lubricating oil supply hole III are respectively positioned at two axial sides of the lubricating oil supply hole II, the lubricating oil supply hole I, the lubricating oil supply hole II and the lubricating oil supply hole III are arranged at the axial middle positions of the pin hole I at one side and the pin hole II at the other side, the lubricating oil supply hole I is matched with the pin hole I, the lubricating oil supply hole III is matched with the pin hole II, lubricating oil flows into the pin hole from the lubricating oil supply hole and flows into the pin hole at the other end from the lubricating oil supply hole, the lubricating oil flows into the connecting rod small-end hole from the lubricating oil supply hole, the lubricating oil flowing out from the lubricating oil supply hole flows into the connecting rod small-end hole and the pin hole.

A plurality of pin hole lubricating holes are arranged at the pin hole part of the piston, the pin hole lubricating holes are respectively communicated with the head cooling cavity or the pin hole cooling cavity, and engine oil enters the pin hole from the head cooling cavity or the pin hole cooling cavity through the pin hole lubricating holes to supply pin hole lubricating oil.

The pin hole lubrication holes comprise a pin hole lubrication hole I, a pin hole lubrication hole II, a pin hole lubrication hole III, a pin hole lubrication hole IV, a pin hole lubrication hole V and a pin hole lubrication hole VI, wherein the pin hole lubrication hole I, the pin hole lubrication hole II and the pin hole lubrication hole III are respectively and symmetrically arranged with the pin hole lubrication hole VI, the pin hole lubrication hole V and the pin hole lubrication hole IV by taking an axial vertical plane of the pin hole as a symmetrical plane.

The steel piston body comprises a piston core part and a piston ring part, wherein an axial bulge is arranged on the upper end surface of the piston ring part, a vertical matching surface is formed by an outer cylindrical surface of the axial bulge and an axial inner hole of the piston core part in a sealing matching mode, a horizontal matching surface is formed by the lower end surface of the piston core part and the upper end surface of the piston ring part in a sealing matching mode, a part of a head cooling cavity is arranged on the piston core part, the other part of the head cooling cavity and a pin hole cooling cavity are arranged on the piston ring part, and the piston core part and the piston ring part are formed by connecting.

The matching surface and the matching surface are connected through laser welding and electron beam welding.

A method for manufacturing a steel piston of a gasoline engine comprises the following steps:

a) firstly, forging a piston core part blank and a piston ring part blank;

b) respectively processing a piston core part cooling cavity and a piston ring part cooling cavity according to the molding shape;

c) processing a piston pin hole cooling cavity by using a drilling machine;

d) then, a pin hole semi-finished product and a lubricating oil supply hole are machined;

e) machining a lubricating oil supply hole;

f) the piston core part and the piston ring part are connected into a whole by welding the vertical matching surface and the horizontal matching surface, and the piston core part cooling cavity and the piston ring part cooling cavity are combined into a head part cooling cavity;

g) and (3) processing piston pin holes by using a boring machine, and then processing a combustion chamber, an annular groove, an oil inlet hole and an oil outlet hole in sequence according to the structural size of the piston to finally form the complete piston.

The invention has the beneficial effects that:

1. according to the invention, a forging forming mode is utilized, high-strength structural steel is selected to replace aluminum-silicon alloy, the strength of the piston body is improved by more than 4 times compared with that of the traditional piston, and the problem of insufficient high-temperature fatigue strength of cast aluminum-silicon alloy is solved.

2. The structure of the invention is that cooling cavities are arranged in the piston and at two sides of a pin hole, and the volume of the cooling cavity is more than 5 times of that of a cooling oil cavity in a traditional casting forming mode; by means of the oil inlet and outlet holes, low-temperature cooling oil enters from the oil inlet hole, then high-temperature oil absorbing heat flows out from the oil outlet hole in time, and the arranged cooling oil cavity can cool the head of the piston and can cool the piston pin hole. The problem of piston cooling capacity not enough is solved.

3. The structure of the invention is provided with two pin hole lubricating oil supply holes, one of which is arranged between the cooling oil cavity and the inner cavity of the piston, and three groups of lubricating oil supply holes are arranged at the position, and after flowing out from the lubricating oil supply holes, the engine oil flows into the small end hole of the piston connecting rod and the inner side of the pin hole of the piston through splash lubrication to lubricate the small end hole of the connecting rod and the pin hole, thus solving the problem of pin hole occlusion. And the other part is positioned between the cooling oil cavity and the pin hole, six lubricating oil supply holes are arranged in each end pin hole, and engine oil flows into the upper side of the pin hole from the cooling oil cavity through the lubricating oil supply holes to supply lubrication to the pin hole, so that the problem of poor lubrication of the pin hole is solved, and the problem of insufficient lubrication capability of the pin hole is solved.

4. When the piston works, the strength of the piston body is improved, the cooling in the piston is enhanced, the temperatures of the head part of the piston and the pin hole part are effectively controlled, the lubricating oil in the pin hole part can be compensated in time, and the requirement of high reliability of the piston of a high-load gasoline engine can be met.

Drawings

FIG. 1 is a schematic view of the piston construction of the present invention;

FIG. 2 is a cross-sectional view F-F of FIG. 1 illustrating the structure and connection of the head cooling cavity and the pin bore cooling cavity;

FIG. 3 is a cross-sectional view N-N of FIG. 1 illustrating the configuration and connection of the pin bore lubrication holes;

FIG. 4 is a cross-sectional view taken along line P-P of FIG. 3, illustrating the structural and positional relationships of the piston pin bore, the oil inlet bore, the oil outlet bore, and the lubricant supply bore;

FIG. 5 is a cross-sectional view taken along line K-K of FIG. 1, illustrating the positional relationship of the head cooling cavity, the lubrication oil supply hole, and the connecting rod small end hole;

fig. 6 is a schematic diagram of a split structure of the piston core part and the piston ring part, and illustrates the positions and the matching relationship of the piston core part and the piston ring part.

Shown in the figure: 1 piston core part, 2 piston ring parts, 3 head cooling cavities, 4 piston pin holes, 5 pin hole cooling cavities, 6 oil inlet holes, 7 oil outlet holes, 8 lubricating oil supply holes, 9 connecting rod small end holes and 10 pin hole lubricating holes.

Detailed Description

In order to make those skilled in the art better understand the technical solution of the present invention, the technical solution in the embodiment of the present invention will be clearly and completely described below with reference to the drawings in the embodiment of the present invention, and it is obvious that the described embodiment is only a part of the embodiment of the present invention, and not all embodiments.

As shown in fig. 1-6, a gasoline engine steel piston comprises a steel piston body, the steel piston body is made of high-strength structural steel, a head cooling cavity 3 is embedded in the upper portion of the steel piston body, a pin hole cooling cavity 5 is arranged at a position close to a piston pin hole 4, the head cooling cavity 3 is communicated with the pin hole cooling cavity 5, the piston head is cooled through the head cooling cavity 3, and the pin hole position is cooled through the pin hole cooling cavity 5.

The oil pump is connected with the power output end of the engine, engine oil enters the cooling oil cavity 3 and the pin hole cooling cavity 5 through the oil inlet 6, and high-temperature oil absorbing heat flows out from the oil outlet 7 and the lubricating oil supply hole 8 after the oscillation cooling is carried out on the head cooling cavity 3 and the pin hole cooling cavity 5.

The steel piston body still is equipped with lubricating oil supply hole 8 near pinhole inboard position, and lubricating oil supply hole 8 and the cooperation of oil outlet 7 position will absorb thermal high temperature oil and flow out through lubricating oil supply hole 8 partly after flowing out from oil outlet 7 after head cooling chamber 3 and pinhole cooling chamber 5 carry out the vibration cooling. The lubricating oil supply holes 8 are provided in plural. Referring to fig. 4 and 5, in the present embodiment, the lubricating oil supply holes include three lubricating oil supply holes I8-1, three lubricating oil supply holes II8-2 and three lubricating oil supply holes III8-3, the lubricating oil supply hole I8-1 and the lubricating oil supply hole III8-3 are respectively located at two axial sides of the lubricating oil supply hole II8-2, the lubricating oil supply hole I8-1, the lubricating oil supply hole II8-2 and the lubricating oil supply hole III8-3 are respectively located at a position axially intermediate between the pin hole I4-1 at one side and the pin hole II4-2 at the other side, wherein the lubricating oil supply hole I8-1 is matched with the pin hole I4-2, the lubricating oil supply hole III8-3 is matched with the pin hole II4-1, and the lubricating oil supply hole II8-2 is matched with the connecting rod small end hole. Lubricating oil flows into the pin hole 4-2 from the lubricating oil supply hole 8-1, flows into the pin hole 4-1 at the other end from the lubricating oil supply hole 8-3, flows into the connecting rod small end hole 9 from the lubricating oil supply hole 8-2, and can flow into the connecting rod small end hole and the pin hole through the lubricating oil supply hole 8, so that lubricating oil compensation is respectively performed on the pin hole and the connecting rod small end hole, and the pin hole and the connecting rod small end hole can be prevented from being occluded. And a plurality of pin hole lubricating holes 10 are arranged at the pin hole part of the piston, and the pin hole lubricating holes 10 are respectively communicated with the head cooling cavity 3 or the pin hole cooling cavity 5 as shown in figure 3. The engine oil enters the pin hole through the pin hole lubrication hole 10 from the head cooling chamber 3 or the pin hole cooling chamber 5, and the pin hole lubrication oil is replenished. In the embodiment, each pin hole lubrication hole 10 is provided with six parts, namely a pin hole lubrication hole I10-1, a pin hole lubrication hole II10-2, a pin hole lubrication hole III10-3, a pin hole lubrication hole IV10-4, a pin hole lubrication hole V10-5 and a pin hole lubrication hole VI10-6, wherein the pin hole lubrication hole I10-1, the pin hole lubrication hole II10-2 and the pin hole lubrication hole III10-3 are respectively and symmetrically arranged with a pin hole lubrication hole VI10-6, a pin hole lubrication hole V10-5 and a pin hole lubrication hole IV10-4 by taking an axial vertical plane of a pin hole as a symmetrical plane.

The steel piston body comprises a piston core part 1 and a piston ring part 2, see fig. 5 and fig. 6, an upper end surface 21 of the piston ring part 2 is provided with an axial protrusion 22, an outer cylindrical surface of the axial protrusion 22 is in sealing fit with an axial inner hole 11 of the piston core part 1 to form a vertical matching surface a, a lower end surface 12 of the piston core part 1 is in sealing fit with the upper end surface 21 of the piston ring part 2 to form a horizontal matching surface b, a part of a head cooling cavity 3 is arranged on the piston core part 1, the other part of the head cooling cavity 3 and a pin hole cooling cavity 5 are arranged on the piston ring part 2, and the piston core part 1 and the piston ring part 2 are formed by sealing connection of.

The matching surface a and the matching surface b are connected by laser welding, electron beam welding and the like.

A method for manufacturing a steel piston of a gasoline engine comprises the following steps:

a) firstly, forging a piston core part blank and a piston ring part blank;

b) respectively processing a piston core part cooling cavity and a piston ring part cooling cavity according to the molding shape;

c) a piston pin hole cooling cavity 5 is machined by a drilling machine;

d) then, a pin hole semi-finished product and a lubricating oil supply hole 10 are processed;

e) machining a lubricating oil supply hole 8;

f) the piston core part and the piston ring part are connected into a whole by a vertical matching surface a and a horizontal matching surface b in a welding mode, and a piston core part cooling cavity and a piston ring part cooling cavity are combined into a head part cooling cavity 3;

g) the piston pin hole 4 is formed by rough and fine machining through a boring mill, and then a combustion chamber, an annular groove, an oil inlet hole and an oil outlet hole are machined in sequence according to the structural size of the piston, and finally the complete piston is formed.

All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.