CN211648321U

CN211648321U - Steel piston

Info

Publication number: CN211648321U
Application number: CN202020353000.0U
Authority: CN
Inventors: 王奕澍; 王世强; 杨志勇; 刘明晖; 张明花; 胡忆明
Original assignee: Hunan Jiangbin Machinery Group Co Ltd
Current assignee: Hunan Jiangbin Machinery Group Co Ltd
Priority date: 2020-03-19
Filing date: 2020-03-19
Publication date: 2020-10-09
Anticipated expiration: 2030-03-19

Abstract

The utility model discloses a steel piston, which comprises a piston main body and a piston ring body positioned at the head part of the piston main body, wherein a cooling oil cavity is formed after the piston main body and the piston ring body are welded and connected; the piston ring body comprises a side surface part and a top surface part, the top surface part is connected with the top of the piston main body, and the side surface part is connected with the side surface of the piston main body; the joint of the piston main body and the top surface part is provided with a top step, and the joint of the piston main body and the side surface part is provided with a side step. The steel piston provided by the utility model has the advantages that the two connecting positions of the piston ring body and the piston main body are arranged in the way that one connecting position is positioned at the top and the other connecting position is positioned at the side, so that the two connecting positions are not easy to interfere with each other when the two connecting positions are fixedly connected, and the processing is more convenient; through the arrangement of the top step and the side step, the step surface of the top step and the step surface of the side step cannot be connected with the cooling oil cavity, welding slag in the inner cooling oil duct is eliminated, and the oil passing effect of the inner cooling oil duct in the piston is improved.

Description

Steel piston

Technical Field

The utility model relates to a piston field especially relates to a steel piston.

Background

The development trend of the engine is miniaturization, the power is continuously improved, the explosion pressure exceeds 20MPa, the piston bears larger load, and designers of the piston continuously design and improve the material and the structure of the piston in order to adapt to the development of the engine, improve the performance, the high-temperature strength and the service life of the piston. The steel piston is a brand new design scheme following the aluminum alloy piston, a piston designer designs a steel-top aluminum skirt bolt connection piston and a steel-top aluminum skirt pendulum body type hinged piston respectively, but both piston structures need to be manufactured by a steel top and an aluminum skirt separately, the thickness difference of the skirt wall of the piston is difficult to guarantee, the casting rejection rate is high, a closed oil cavity is difficult to form by the pendulum body type piston, and the cooling effect of the piston is poor.

The prior art discloses a laser welding forged steel integral piston with a closed cooling oil cavity and a manufacturing process thereof. An inner cooling oil cavity is formed between the two welded parts and is communicated with the inner cavity of the piston through at least two oil inlet and outlet holes, oil can be fed or discharged, when the piston works in an engine, engine oil is sprayed from the oil inlet hole, flows in the annular cooling cavity and flows out of the oil outlet hole, the heat of the piston is taken away, the working temperature of each part of the piston is reduced, and the working reliability of the piston and a piston ring is ensured.

However, in the above method, firstly, the welding seams of the piston are all penetrating welding seams, welding slag is easily formed at the welding seam outlet, exists on the inner wall of the oil duct and the welding seams in the oil duct, and is difficult to remove, and when the piston runs in the engine, due to the existence of the welding slag, firstly, the passing efficiency of the cooling oil is affected, secondly, as the running time of the piston is prolonged, the welding slag falls off from the inner wall of the oil duct, enters the cooling system of the engine along with the cooling oil, and causes quality accidents such as cylinder scuff; secondly, the oil inlet and outlet holes are processed after welding, burrs are easily formed on the inner side of the oil cavity when the oil inlet and outlet holes are processed, the burrs are difficult to remove, the passing efficiency of cooling oil is influenced, welding slag falls off from the inner wall of the oil passage along with the increase of the operation time of the piston, and the welding slag enters an engine cooling system along with the cooling oil, so that quality accidents such as cylinder scuffing are caused.

The prior art also discloses a piston for an internal combustion engine and a manufacturing method of the piston, wherein the piston is composed of a first piston component and a second piston component, the first piston component and the second piston component are welded by friction welding, a weld crater is formed in an oil passage, and the passing efficiency of cooling oil of the piston is influenced when the piston runs in an engine.

Therefore, how to improve the performance of the steel piston in the operation of the engine is a technical problem which needs to be solved by the technical personnel in the field at present.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a steel piston, this steel piston can effectual improvement self machining efficiency and intensity, simultaneously, avoids the existence of welding slag in the cooling oil tank, improves the current efficiency of coolant oil.

In order to achieve the above object, the utility model provides a following technical scheme:

a steel piston comprises a piston main body and a piston ring body positioned at the head of the piston main body, wherein a cooling oil cavity is formed after the piston main body and the piston ring body are welded and connected; the piston ring body includes a side portion and a top portion, the top portion being connected to a top of the piston body, the side portion being connected to a side of the piston body; the piston is characterized in that a top step is arranged at the joint of the piston main body and the top surface part, and a side step is arranged at the joint of the piston main body and the side surface part.

Preferably, the piston main body and the piston ring body are fixed by high-energy beam welding.

Preferably, the piston ring body is a right-angled corner along the axial cross section.

Preferably, the outer peripheral portion of the piston ring body is provided with an annular groove.

Preferably, the piston body is provided with an oil hole through which cooling oil flows into or out of the cooling oil chamber.

Preferably, the top surface portion and the top of the piston body have a top weld, the top weld surrounding in parallel to the axial direction; the side section and the side of the piston body have a circumferential weld that surrounds perpendicular to the axial direction.

Preferably, the relationship between the step height B of the top step and the step width a of the top step is: b ═ A +2 mm)/20; the relationship between the step height D of the side step and the step width C of the side step is as follows: d ═ C +2 mm)/20.

Preferably, the minimum distance E between the inner side of the step surface of the side step and the inner wall of the oil hole is 3.5-4.5 mm.

Preferably, the piston main body and the piston ring body are of an integrally cast structure.

The steel piston provided by the utility model comprises a piston main body and a piston ring body positioned at the head part of the piston main body, wherein a cooling oil cavity is formed after the piston main body is welded and connected with the piston ring body; the piston ring body includes a side portion and a top portion, the top portion being connected to a top of the piston body, the side portion being connected to a side of the piston body; the piston is characterized in that a top step is arranged at the joint of the piston main body and the top surface part, and a side step is arranged at the joint of the piston main body and the side surface part. The utility model provides a steel piston, the piston ring body with two junctions of piston main part, a department is located the top, and a department is located the side, so sets up, when both fixed connection, two junction positions are difficult to mutual interference, and processing is more convenient, in addition, through the setting of top step and side step for the step face of top step and the step face of side step all can not be connected with the cooling oil pocket, and then eliminate the welding slag in the interior cold-oil duct, improve the logical oily effect of cold-oil duct in the piston.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is an axial cross-sectional view of one embodiment of a steel piston provided by the present invention;

FIG. 2 is a top view of one embodiment of a steel piston provided by the present invention;

FIG. 3-1 is an enlarged schematic view of the M position of the steel piston shown in FIG. 1 prior to welding;

3-2 are enlarged structural views of the M position of the steel piston shown in FIG. 1 after welding;

3-3 are enlarged structural views of the N position of the steel piston shown in FIG. 1 before welding;

FIGS. 3-4 are enlarged schematic views of the N position of the steel piston shown in FIG. 1 after welding;

fig. 4 is a schematic structural diagram of a piston main body in a steel piston provided by the present invention;

fig. 5 is a schematic structural view of a piston ring body in a steel piston provided by the present invention;

wherein: a piston body-1; a piston ring body-2; circumferential weld-3; top weld-4; a cooling oil cavity-5; an annular groove-6; a skirt-7; a combustion chamber-8; piston pin bore-9; an oil hole-10.

Detailed Description

The core of the utility model is to provide a steel piston, this steel piston can improve the machining efficiency and the intensity of self, simultaneously, avoids the existence of welding slag in the cooling oil tank, improves the current efficiency of coolant oil.

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

Referring to fig. 1 to 5, fig. 1 is an axial cross-sectional view of a steel piston according to an embodiment of the present invention; FIG. 2 is a top view of one embodiment of a steel piston provided by the present invention; FIG. 3-1 is an enlarged schematic view of the M position of the steel piston shown in FIG. 1 prior to welding; 3-2 are enlarged structural views of the M position of the steel piston shown in FIG. 1 after welding; 3-3 are enlarged structural views of the N position of the steel piston shown in FIG. 1 before welding; FIGS. 3-4 are enlarged schematic views of the N position of the steel piston shown in FIG. 1 after welding; fig. 4 is a schematic structural diagram of a piston main body in a steel piston provided by the present invention; fig. 5 is a schematic structural view of a piston ring body in a steel piston according to the present invention.

In this embodiment, the steel piston includes a piston main body 1 and a piston ring body 2. Wherein, the piston ring body 2 is located the head of piston main part 1, and welded connection between piston main part 1 and the piston ring body 2 forms cooling oil chamber 5 between the two after piston main part 1 welds with the piston ring body 2, all has the structure that can form cooling oil chamber 5 on piston main part 1 and the piston ring body 2 promptly, still is equipped with skirt portion 7 on the piston main part 1 to processing has piston pin hole 9, and ring channel 6 has been seted up to the peripheral part of the piston ring body 2.

Further, the piston ring body 2 comprises a side surface part and a top surface part, and preferably, the piston ring body 2 is in a right-angle corner along the axial section; the top surface part is connected with the top of the piston main body 1, and the side surface part is connected with the side surface of the piston main body 1; a top step is arranged at the joint of the piston main body 1 and the top surface part, and a side step is arranged at the joint of the piston main body 1 and the side surface part; and the step surface of the top step and the step surface of the side step are not connected with the cooling oil chamber 5.

The utility model provides a steel piston, two junctions of piston ring body 2 and piston main part 1, a department is located the top, a department is located the side, so set up, when both fixed connection, two junction positions are difficult to mutual interference, it is more convenient to process, in addition, through the setting of top step and side step, make the junction of piston ring body 2 and piston main part 1, make the step face of top step and the step face of side step all can not be connected with cooling oil cavity 5, and then eliminate the welding slag in the interior cold oil duct, improve the logical oily effect of cold oil duct in the piston.

Preferably, both the piston body 1 and the piston ring body 2 are integrally cast in order to improve the strength thereof.

Further, the piston main body 1 and the piston ring body 2 are fixed by high-energy beam welding, which is welding with plasma beams, electron beams or laser beams as a high-energy density heat source, because of the high energy beam welding, the welding depth can not be effectively controlled, the depth control range is large, and the welding depth fluctuates within 0-2mm on one side, the arrangement of the top step and the side steps prevents the tail end of the welding line from being present on the inner wall surface of the cooling oil cavity 5, avoids the welding line from being welded through, thereby avoiding that welding slag is formed on the inner wall of the oil duct or in the oil duct of the cooling oil cavity 5 at the tail end of the welding line after welding, the welding slag is attached to the inner wall of the oil duct and is difficult to remove, however, in the running process of the engine, welding slag can fall off from the inner wall of the oil duct along with the rise of the temperature of the piston and enter a cooling system of the engine along with cooling oil, so that quality accidents such as cylinder pulling and the like are caused. The strength of the high-energy beam welding is adjusted through welding parameters, and the depth-to-width ratio is preferably controlled to be 10: 1.

In addition to the above embodiments, the piston ring body 2 has a right-angled corner in an axial cross section, that is, the piston ring body 2 has a cylindrical structure with an annular bottom surface at one end, and covers the head of the piston main body 1.

In addition to the above embodiments, the piston main body 1 is provided with oil holes 10 through which cooling oil flows into and out of the cooling oil chamber 5. The oil holes 10 include an oil inlet hole through which cooling oil flows into the cooling oil chamber 5 and an oil outlet hole through which cooling oil flows out of the cooling oil chamber 5.

On the basis of the above embodiments, the top surface portion and the top of the piston main body 1 have the top weld 4, and the top weld 4 surrounds in parallel to the axial direction; side portion has circumferential weld 3 with the side of piston main part 1, and circumferential weld 3 perpendicular to axial encircles, as shown in fig. 1, and top weld 4 is perpendicular with the extending direction of circumferential weld 3, so sets up, can reduce the mutual interference between two welds, further improves the firm in connection nature between piston main part 1 and the piston ring body 2.

In addition to the above embodiments, the relationship between the step height B of the top step and the step width a of the top step is: b ═ A +2 mm)/20; the relationship between the step height D of the side step and the step width C of the side step is: d ═ C +2 mm)/20.

It should be noted here that the step surface of the top step and the step surface of the side step both refer to surfaces for forming a weld, as shown in fig. 3-1 to 3-4.

In each of the above embodiments, the minimum distance E between the inner side of the step surface of the side step and the inner wall of the oil hole 10 is 3.5 to 4.5 mm. The above arrangement is that the size of E is larger than 3.5-4.5mm, and preferably keeps a distance of 2mm from the inner wall of the oil passage except for the fluctuation of welding depth of 2mm because the welding of the annular seam is to pay attention to the position of the oil inlet and outlet hole, and the oil inlet and outlet hole cannot be welded through, so as to prevent the formation of welding slag on the inner wall of the oil inlet and outlet hole.

Specifically, the steel piston provided by the embodiment has the following processing procedures:

forging a piston main body 1 blank of the steel piston; forging a piston ring body 2 blank of the steel piston; an oil inlet and outlet hole is processed on the blank of the piston main body 1, and a cooling oil cavity 5, a circumferential weld 3 and a top weld 4 are respectively processed on the blank of the piston main body 1 and the blank of the piston ring body 2, wherein the positions of the circumferential weld 3 and the top weld 4 are as above; after the piston main body 1 and the piston ring body 2 are assembled into a whole, the piston ring body 2 and the piston main body 1 are connected into a whole by a high-energy beam welding method; subsequently, performing finish machining on the piston to respectively machine a piston pin hole 9, an annular groove 6, a combustion chamber 8, an excircle and the like; and carrying out phosphating treatment on the surface of the piston.

The phosphating treatment is a protection process of reacting the steel piston with dilute phosphoric acid or phosphate solution to form a phosphate film on the surface of the steel piston, and can improve the corrosion resistance, the wear resistance and the heat resistance of the steel piston. During the machining, the piston oil inlet and outlet hole is machined before welding. The oil hole 10 is processed before the cooling oil cavity 5 is closed, and burrs formed during processing of the oil hole 10 can be well removed.

According to the steel piston provided by the embodiment, due to optimization of the position of the welding line, welding slag does not exist in the cooling oil cavity 5 of the steel piston, and the problem that the passing efficiency of cooling oil is influenced due to the existence of the welding slag is solved; in addition, burrs caused by machining of the oil inlet and outlet holes before welding can be removed easily, and the problem that the burrs exist after the cooling oil cavity 5 is closed is solved.

The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other.

The steel piston provided by the utility model is described in detail above. The principles and embodiments of the present invention have been explained herein using specific examples, and the above descriptions of the embodiments are only used to help understand the method and its core ideas of the present invention. It should be noted that, for those skilled in the art, without departing from the principle of the present invention, the present invention can be further modified and modified, and such modifications and modifications also fall within the protection scope of the appended claims.

Claims

1. A steel piston comprises a piston main body (1) and a piston ring body (2) located at the head of the piston main body (1), and is characterized in that a cooling oil cavity (5) is formed after the piston main body (1) and the piston ring body (2) are welded and connected; the piston ring body (2) comprises a side surface part and a top surface part, the top surface part is connected with the top of the piston main body (1), and the side surface part is connected with the side surface of the piston main body (1); the piston is characterized in that a top step is arranged at the joint of the piston main body (1) and the top surface part, and a side step is arranged at the joint of the piston main body (1) and the side surface part.

2. A steel piston according to claim 1, characterized in that the piston body (1) and the piston ring body (2) are fixed by high energy beam welding.

3. A steel piston according to claim 1, characterized in that the piston ring body (2) is a right-angled corner in axial cross-section.

4. A steel piston according to claim 1, characterized in that the outer circumference of the piston ring body (2) is provided with an annular groove (6).

5. The steel piston as claimed in claim 1, characterized in that the piston main body (1) is provided with oil holes for cooling oil to flow into or out of the cooling oil chamber (5).

6. A steel piston according to claim 1, characterized in that the top surface part and the top of the piston body (1) have a top weld seam (4), which top weld seam (4) is circumferential in parallel to the axial direction; the side face part and the side face of the piston body (1) have a circumferential weld seam (3), the circumferential weld seam (3) running perpendicular to the axial direction.

7. The steel piston as claimed in any one of claims 1 to 6 wherein the relationship between the step height B of the top step and the step width A of the top step is: b ═ A +2 mm)/20; the relationship between the step height D of the side step and the step width C of the side step is as follows: d ═ C +2 mm)/20.

8. The steel piston as claimed in claim 7 wherein a minimum distance E between an inner side of the step face of the side step and an inner wall of the oil hole is 3.5-4.5 mm.

9. The steel piston according to any of claims 1 to 6, characterized in that the piston body (1) and the piston ring body (2) are of an integrally cast structure.