CN116971887A - Lightweight structure of high-strength diesel engine steel piston - Google Patents

Abstract

The invention relates to a lightweight structure of a highly reinforced diesel engine steel piston. The highly reinforced diesel engine steel piston has a head (1). The lightweight structure includes a lightweight head (1) and a lightweight pin hole (2). ) and a lightweight skirt (3); the head (1) contains a steel piston internal cooling oil chamber (13), and is located on the fire bank (8), the second bank (9), and the third bank. (10), an annular weight-reducing cavity is provided at the lower edge (11) of the third annular groove (11) and the lower area (12) of the bottom ring of the combustion chamber; the pin hole (2) is formed by the first rib (4) and the second rib ( 5) Connect the head (1); the skirt (3) is connected to the pin hole (2) by the third rib (6); the skirt (3) is connected to the head (1) by the fourth rib (7) . The lightweight structure of the present invention can systematically reduce the weight of the steel piston head structure, pin seat structure, and skirt structure of the diesel engine, and reduce the weight of the steel piston to within an acceptable range.

Description

A lightweight structure of highly reinforced diesel engine steel piston

Technical field

The present invention relates to an engine piston, and in particular to a lightweight structure of a highly reinforced diesel engine steel piston, specifically to a lightweight structure of the head, pin seat and skirt of the steel piston.

Background technique

In order to meet the requirements for diesel engines to continue to develop in the direction of high reinforcement, lightweight, compactness, and low emissions, steel pistons have gradually replaced traditional aluminum alloy pistons due to their high-strength material advantages and become the first choice for highly reinforced diesel engine pistons. However, the density of steel is higher than that of aluminum alloy. If the structure and size of the existing aluminum alloy piston are designed, the weight of the steel piston will increase by 1.9 times, which will greatly increase the reciprocating inertial force of the piston and affect the dynamic performance of the piston, the balance and vibration of the entire machine. impact, thereby affecting the reliability of engine parts. Therefore, how to realize the lightweight design of the steel piston structure is the key to improving the independent research and development level of domestic high-strength diesel engine steel pistons.

Chinese patent CN 102979641 A discloses an integral cast steel piston with a window-type weight reduction area on the piston skirt. The integral cast steel piston reduces the weight by more than 15% to 20%, making the overall cast steel piston nearly the same weight. The weight of aluminum alloy piston meets the requirements of lightweight engine. This patent has an annular cavity reduction cavity between the annular groove area and the skirt, and a window-type weight reduction area on the piston skirt in the direction of the pin hole. This weight reduction structure is simply based on the original structure. Removing material inward does not change its topology, and there is still plenty of room for weight reduction in the steel piston. Chinese patent CN 107313873A discloses a lightweight piston, which adopts an asymmetric piston structure, and the upper end of the outer pin seat is processed to remove the flesh, the upper end of the outer pin seat is hollowed out, and the window is thinned. Although this patent can reduce the weight of the piston, the piston structure diagram shown in the patent does not have an internal cooling oil chamber structure, so the piston still has a lot of room for weight reduction, and a piston without an internal cooling oil chamber structure will bear the Greater thermal load affects the service life of the piston. Chinese patent CN 114165353 A discloses a lightweight piston, which includes a piston body. The piston body is provided with a piston head and a piston skirt. The piston head is provided with an annular oil chamber. The piston skirt and/or the piston head are An annular weight-reducing cavity is provided. This patent has an oil hole on the annular plate for connecting the annular oil chamber and the annular weight reduction chamber. This structure is essentially an oil chamber structure. Compared with without this structure, the weight can be further reduced, and this structure will also affect The oscillatory flow and heat transfer of the fluid in the oil chamber are not worth the gain. Chinese patent CN202970934 U discloses a new type of lightweight internally cooled ring piston for gasoline engines. The upper part of the window of the piston body is designed with a weight reduction cavity. This weight reduction structure is based on the original structure by simply removing material inward, and There is still a lot of room for weight reduction in the steel piston without changing its topology. Chinese patent CN 215292702 U discloses a lightweight piston with an arched skirt. The piston pin seat is provided with a lightweight arc-shaped structure with a concave interior. The weight-reducing structure is simply modified on the basis of the original structure. Removing material inward does not change its topology, and there is still a lot of room for weight reduction in the steel piston. Chinese patent CN 217270508 U discloses a lightweight piston. Although this structure can reduce the weight of the piston, it does so without sacrificing the cooling function of the internal cooling oil chamber, and the weight reduction solution is too cumbersome. At the same time, the piston can still be used. Room to lose weight. Chinese patent CN 218581707U discloses an M-shaped lightweight piston and engine. By reducing the thickness of the lower end of the piston window, the cross-section of the lower end of the piston window forms an M shape, thereby reducing the overall weight of the piston. This weight-reducing structure is based on the original Simply removing material inward from the structure does not change its topology, and there is still a lot of room for weight reduction in the steel piston.

To sum up, the current weight reduction of the steel piston structure mainly focuses on the meat removal of the steel piston structure. Although this method can reduce the weight of the steel piston to a certain extent, this method does not change the topological structure of the steel piston itself. There's still plenty of room for weight savings with steel pistons. Steel has a higher density than aluminum, and the problem of lightweighting is difficult to effectively solve. Therefore, the task of reducing the weight of the steel piston structure is particularly important.

The current weight optimization of steel piston structures mainly has the following shortcomings:

1) There is no systematic lightweighting of key areas of the steel piston;

2) The weight of the steel piston is still not within the acceptable range.

Contents of the invention

The present invention aims at solving the problems existing in the prior art and provides a lightweight structure of a highly reinforced diesel engine steel piston.

In order to solve the above technical problems, the present invention is implemented by adopting the following technical solutions:

A lightweight structure of a highly reinforced diesel engine steel piston. The highly reinforced diesel engine steel piston has a head. The lightweight structure includes a lightweight head, a lightweight pin hole and a lightweight skirt; the head It contains an internal cooling oil chamber of the steel piston, and an annular weight reduction cavity is provided at the fire bank, the second ring bank, the third ring bank, the lower edge of the third ring groove and the lower area of the bottom ring of the combustion chamber. The annular weight reduction chamber is The cross-sectional shape is a closed section arbitrarily composed of curves; the annular weight-reducing cavity is not connected with the internal cooling oil cavity; the pin hole is connected to the head by the first rib and the second rib, and the first rib is located The plane of the second rib is parallel to the direction of the pin hole, and the plane of the second rib is perpendicular to the direction of the pin hole; the skirt is connected to the pin hole by the third rib, and is connected to the head by the fourth rib; the skirt The projection shape is a closed interval arbitrarily composed of curves, and the height range of the skirt projection shape does not exceed the bottom and top of the pin hole projection shape in the height direction.

Further, the number of said annular weight-reducing cavities is greater than one.

Furthermore, the cross-sectional shape of the annular weight-reducing cavity is a closed section composed of a circle, an arbitrary polygon or an elliptical curve.

Further, the shortest distance between any position in the cross-section of the annular weight-reducing cavity and any position in the cross-section of the steel piston is not less than 1 mm.

Further, the lower area of the combustion chamber bottom ring includes the transition area from the bottom of the combustion chamber to the top of the steel piston inner cavity.

Further, the number of the first ribs is not less than 2.

Further, the number of the second ribs is an even number greater than 2 and is symmetrically distributed.

Further, the projected shape of the skirt includes a closed section composed of a circle, an arbitrary polygon or an elliptical curve.

Further, the number of the fourth ribs is not less than 2.

Further, the number of the third ribs is greater than one.

Beneficial effects of the present invention:

The diesel engine steel piston lightweight structure of the present invention can systematically reduce the diesel engine steel piston head structure, pin seat structure, and skirt structure, and reduce the weight of the steel piston to an acceptable range. Specifically, it includes:

(1) Lightweight steel piston head. This invention uses an annular weight reduction chamber to reduce the weight of the steel piston head area on the premise of retaining the structure of the inner cooling oil chamber of the steel piston, and the position of the annular weight reduction chamber does not affect the steel piston head. The role of key areas such as the piston combustion chamber, annular land and annular groove ensures that the steel piston head is lightweight on the premise that it has good cooling performance;

(2) Lightweight steel piston pin seat. This invention connects the steel piston head and the pin hole through ribs while retaining the pin hole structure in contact with the piston pin. This method changes the topological structure of the steel piston pin seat itself. , thus achieving a lightweight steel piston pin seat structure;

(3) Lightweight steel piston skirt. The skirt structure of the present invention is not directly connected to the steel piston head, but connects the two through ribs. The skirt structure of the present invention ensures that the piston can move in the cylinder. The reciprocating motion plays a guiding role and can reduce the skirt structure to the minimum while bearing side pressure. This method changes the topological structure of the steel piston skirt itself, thereby achieving a lightweight steel piston skirt structure;

(4) Compared with the unchanged steel piston, the lightweight structure of the steel piston of the present invention can reduce the weight by up to 40%.

Description of the drawings

The present invention will be further described below in conjunction with the accompanying drawings:

Figure 1 is a triaxial view of the steel piston;

Figure 2 is a schematic diagram of the vertical pin hole direction of the steel piston;

Figure 3 is a schematic diagram of the direction of the parallel pin hole of the steel piston;

Figure 4 is a sectional view of the steel piston perpendicular to the pin hole direction of the present invention;

Figure 5 is a cross-sectional view of the steel piston of the present invention in the direction parallel to the pin hole;

Figure 6 is a schematic diagram of the relationship between the plane where the first rib and the second rib are located and the direction of the pin hole according to the present invention;

The reference numbers in the figure are: 1-head, 2-pin hole, 3-skirt, 4-first rib, 5-second rib, 6-third rib, 7-fourth rib, 8-firepower Bank, 9-the second ring bank, 10-the third ring bank, 11-the lower edge of the third ring groove, 12-the lower area of the bottom ring of the combustion chamber, 13-the steel piston inner cooling oil chamber.

Detailed ways

The following is a detailed description of the embodiments of the present invention. This embodiment is implemented based on the technical solution of the present invention and provides detailed implementation modes and specific operating processes. However, the protection scope of the present invention is not limited to the following implementations. example.

Referring to Figures 1 to 3, the following takes the lightweight structure of a certain diesel engine steel piston as an example. The lightweight structure of a highly reinforced diesel engine steel piston is achieved through the following structure:

1)Lightweight head structure

As shown in Figures 4 and 5, on the premise of retaining the structure of the steel piston internal cooling oil chamber 13, the fire power bank 8, the second ring bank 9, the third ring bank 10, the lower edge of the third ring groove 11, and the bottom of the combustion chamber are An annular weight reduction cavity is opened at the lower ring area 12 of the combustion chamber. The lower area 12 of the combustion chamber bottom ring includes but is not limited to the transition area from the bottom of the combustion chamber to the top of the steel piston inner cavity.

The annular weight reduction cavity is not connected with the internal cooling oil cavity, and is opened at the fire bank 8, the second bank 9, the third bank 10, the lower edge of the third ring groove 11, and the lower area 12 of the bottom ring of the combustion chamber. The number of said annular weight-reducing cavities is not less than 1.

The cross-sectional shape of the annular weight-reducing cavity can be a closed interval composed of curves, including circles, arbitrary polygons, ellipses, etc., and the shortest distance between any position in the cross-section and any position in the steel piston cross-section is not less than 1 mm. .

2)Lightweight pin seat structure

As shown in Figures 4 and 5, the pin hole 2 is connected to the head 1 by a first rib 4 and a second rib 5. The plane where the first rib 4 connecting the pin hole 2 and the head 1 is parallel to the direction of the steel piston pin hole , the number of ribs is not less than 2.

The plane of the second rib 5 connecting the pin hole 2 and the head 1 is perpendicular to the direction of the steel piston pin hole. The number of ribs is an even number and not less than 2, and they are symmetrically distributed.

3)Lightweight skirt structure

As shown in Figures 4 and 5, the skirt 3 is connected to the pin hole 2 by the third rib 6, and the fourth rib 7 is connected to the head 1; the number of the fourth ribs 7 connecting the skirt 2 and the head 1 is not less than 2 The number of the third ribs 6 connecting the skirt 3 and the pin hole 2 is not less than 1.

The projected shape of the skirt 3 can be a closed section arbitrarily composed of curves, including circles, arbitrary polygons, ellipses, etc. The range of the height direction of the projected shape of the skirt 3 must not exceed the height direction of the projected shape of the pin hole 2 bottom and top.

Claims (10)

1. A lightweight structure of a highly reinforced diesel engine steel piston. The highly reinforced diesel engine steel piston has a head (1), which is characterized by: The lightweight structure includes a lightweight head (1), a lightweight pin hole (2) and a lightweight skirt (3); The head (1) contains a steel piston internal cooling oil chamber (13), which is located on the fire bank (8), the second ring bank (9), the third ring bank (10), and the lower edge of the third ring groove (11 ) and the lower area (12) of the bottom ring of the combustion chamber are provided with an annular weight-reducing cavity. The cross-sectional shape of the annular weight-reducing cavity is a closed section arbitrarily composed of curves; the annular weight-reducing cavity is not connected with the internal cooling oil chamber. ; The pin hole (2) is connected to the head (1) by a first rib (4) and a second rib (5). The plane where the first rib (4) is located is parallel to the direction of the pin hole (2). The plane where the second rib (5) is located is perpendicular to the direction of the pin hole (2); The skirt (3) is connected to the pin hole (2) by the third rib (6), and is connected to the head (1) by the fourth rib (7); the projected shape of the skirt (3) is A closed interval formed arbitrarily by a curve, and the range in the height direction of the projected shape of the skirt (3) does not exceed the bottom and top of the height direction of the projected shape of the pin hole (2). 2. The steel piston lightweight structure as claimed in claim 1, characterized in that: The number of said annular weight-reducing cavities is greater than one. 3. The steel piston lightweight structure according to claim 1, characterized in that: The cross-sectional shape of the annular weight-reducing cavity is a closed section composed of a circle, an arbitrary polygon or an elliptical curve. 4. The steel piston lightweight structure according to claim 1, characterized in that: The shortest distance between any position in the cross-section of the annular weight-reducing cavity and any position in the cross-section of the steel piston is not less than 1 mm. 5. The steel piston lightweight structure as claimed in claim 1, characterized in that: The lower area (12) of the combustion chamber bottom ring includes the transition area from the bottom of the combustion chamber to the top of the steel piston inner cavity. 6. The steel piston lightweight structure according to claim 1, characterized in that: The number of the first ribs (4) is not less than 2. 7. The steel piston lightweight structure according to claim 1, characterized in that: The number of the second ribs (5) is an even number greater than 2 and is symmetrically distributed. 8. The steel piston lightweight structure according to claim 1, characterized in that: The projected shape of the skirt (3) includes a closed section composed of a circle, an arbitrary polygon or an elliptical curve. 9. The steel piston lightweight structure according to any one of claims 1 to 8, characterized in that: The number of the fourth ribs (7) is not less than 2. 10. The steel piston lightweight structure according to any one of claims 1 to 8, characterized in that: The number of the third ribs (6) is greater than one.