CN212376754U - Skirt asymmetric piston and engine - Google Patents
Skirt asymmetric piston and engine Download PDFInfo
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- CN212376754U CN212376754U CN202020726565.9U CN202020726565U CN212376754U CN 212376754 U CN212376754 U CN 212376754U CN 202020726565 U CN202020726565 U CN 202020726565U CN 212376754 U CN212376754 U CN 212376754U
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Abstract
The utility model discloses a skirt asymmetric piston and an engine, which relate to the field of engine pistons and comprise a piston skirt, the side surface of the piston skirt part is divided into a thrust side and a reverse thrust side, the utility model has simple structure and novel structure, according to the engine at the operation in-process, the thermal expansion volume of piston skirt thrust side and thrust side is different, the utility model discloses the pitch arc that forms piston skirt thrust side and thrust side is designed into asymmetric form, the decrement of increase piston thrust side skirt portion, make the engine in operation, the decrement of piston skirt thrust side offsets with its inflation volume after being heated, make the clearance between piston skirt thrust side and the cylinder can be in a reasonable within range, reduce the possibility that produces the contact between piston skirt thrust side and the cylinder, thereby reduce the friction that the contact produced between piston and the cylinder and the combustion load of engine.
Description
Technical Field
The utility model relates to an engine piston field specifically is an asymmetric piston of skirt portion and engine.
Background
Piston is at engine cylinder barrel operation in-process, and the skirt portion is because the thermal expansion, and the diameter increases, for preventing that skirt portion and cylinder barrel from taking place strong contact, avoids piston operation posture to worsen and even draws influence such as jar, often can be for skirt portion design molded lines, and the molded lines design generally uses symmetrical molded lines to design to be the owner.
Under the condition that the temperature is too high or the piston moves and swings too greatly, when the symmetrical molded line design is adopted, the phenomenon that the gap between the piston and the cylinder barrel is too small occurs, so that the contact between the piston thrust side skirt part and the cylinder barrel is strong, the friction is too large, the running posture of the piston is deteriorated, and the combustion load of an engine is large.
SUMMERY OF THE UTILITY MODEL
An object of the utility model is to provide an asymmetric piston of skirt section and engine designs into partial asymmetric form through the pitch arc with piston skirt section thrust side and reverse thrust side formation to solve the problem that proposes among the above-mentioned background art.
In order to achieve the above object, the utility model provides a following technical scheme:
the side surface of the piston skirt is divided into a thrust side surface and a reverse thrust side surface, the horizontal distance between the highest point of an arc line formed by the thrust side surface and the highest point of an arc line formed by the reverse thrust side surface in the piston skirt is a basic diameter D0 of the piston, the arc line of the thrust side surface is divided into a first molded line and a second molded line which are connected in a front-back two-section mode by a straight line of the basic diameter, the arc line of the reverse thrust side surface is divided into a third molded line and a fourth molded line which are connected in a front-back two-section mode by a straight line of the basic diameter, and the first molded line meets the equation x 0.00043y 20.00129y-D0/2, wherein the x axis in the equation is a straight line where the basic diameter of the piston is located, the y axis in the equation is a radial center line of the piston perpendicular to the basic diameter of the piston, the value range of y in the equation is more than or equal to 3 and less than or equal to 21, the second molded line and the fourth molded line are symmetrical about the y axis, and the first molded line and the third molded line are asymmetrical about the y axis.
As a further aspect of the present invention: under the condition that the distance between the point on the first molded line and the point on the third molded line is the same as the distance between the point on the first molded line and the y axis, the distance L1 between the point on the first molded line and the y axis is smaller than the distance between the point on the third molded line and the y axis.
As a further aspect of the present invention: the value range of D0 is respectively 73mm and 86mm, and D0 is not less than.
An engine comprising a skirted asymmetric piston as described above.
Compared with the prior art, the beneficial effects of the utility model are that: the utility model discloses novel structure, according to the engine at the operation in-process, the thermal expansion volume of piston skirt thrust side and thrust side is different, the utility model discloses design into asymmetric form with the pitch arc that piston skirt thrust side and thrust side formed, increase the decrement of piston thrust side skirt portion, make the engine in operation, the decrement of piston skirt thrust side offsets with its inflation volume after being heated, make the clearance between piston skirt thrust side and the cylinder can be in a reasonable within range, reduce the possibility that produces the contact between piston skirt thrust side and the cylinder to reduce the friction that the contact produced between piston and the cylinder and the combustion load of engine.
Drawings
FIG. 1 is a front view of an asymmetric skirt piston;
FIG. 2 is a partial top cross-sectional view of an asymmetric skirt piston;
FIG. 3 is a skirt face pressure test profile for an asymmetric skirt piston having a D0 of 73 mm;
FIG. 4 is a skirt face pressure test profile for a prior art skirt symmetric piston with a DO of 73 mm;
FIG. 5 is a skirt face pressure test profile for an asymmetric skirt piston having a D0 of 77 mm;
FIG. 6 is a skirt face pressure test profile for a prior art skirt symmetric piston with a DO of 77 mm;
FIG. 7 is a skirt face pressure test profile for an asymmetric skirt piston having a D0 of 82 mm;
FIG. 8 is a skirt face pressure test profile for a prior art skirt symmetric piston with a DO of 82 mm;
FIG. 9 is a skirt face pressure test profile for an asymmetric skirt piston having a D0 of 86 mm;
FIG. 10 is a skirt face pressure test profile for a prior art skirt symmetric piston having a DO of 86 mm;
in the figure: 10-piston, 20-thrust side face, 21-first molded line, 22-second molded line, 30-reverse thrust side face, 31-third molded line and 32-fourth molded line.
Detailed Description
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, in an embodiment of the present invention, an asymmetric piston for skirt and an engine include a piston skirt, a side surface of the piston skirt is equally divided into a thrust side 20 and a reverse thrust side 30, an arc line formed by the thrust side of the piston skirt has a highest point, and similarly, an arc line formed by a non-thrust side of the piston skirt also has a highest point, a horizontal distance between the highest point of the arc line of the thrust side and the highest point of the arc line of the reverse thrust side is a basic diameter D0 of the piston, the straight line of the basic diameter of the piston divides the arc line of the thrust side into a first profile 21 and a second profile 22 which are connected in a front-back two sections, and the straight line of the basic diameter divides the arc line of the reverse thrust side into a third profile 31 and a fourth.
The second profile 22 and the fourth profile 32 are symmetrical with respect to a piston radial center line perpendicular to the piston basic diameter, and the first profile 21 and the third profile 31 are asymmetrical with respect to a piston radial center line perpendicular to the piston basic diameter, which is specifically represented by: under the condition that the point on the first profile 21 and the point on the third profile 31 are at the same distance from the x-axis, the distance L1 between the point on the first profile and the y-axis is smaller than the distance between the point on the third profile and the y-axis.
The first profile satisfies the equation x 0.00043y20.00129y-D0/2, wherein the x axis in the equation is a straight line where the basic diameter of the piston is located, the y axis is a radial center line of the piston perpendicular to the basic diameter of the piston, the value range of y in the equation is 3mm or more and 21mm or less, and D0 can be, but is not limited to 73mm, 77mm, 82mm and 86 mm.
The skirt thrust side and the counterthrust side profile of the piston are asymmetric, and the arc radian formed by the thrust side is smaller than that formed by the counterthrust side, and the piston is mainly characterized in that: under the condition that the point on the first profile 21 and the point on the third profile 31 are at the same distance from the x-axis, the distance L1 between the point on the first profile and the y-axis is smaller than the distance between the point on the third profile and the y-axis. Based on the characteristics of the piston skirt, the utility model sets the thrust side and the reverse thrust side of the piston skirt into an asymmetrical form, so that the radian of the arc formed by the thrust side of the piston skirt is smaller than that formed by the reverse thrust side of the piston, when the engine is in operation, the thrust side of the piston skirt is smaller than that formed by the reverse thrust side of the piston, the expansion amount heated by the thrust side face of the piston skirt part can be offset, so that a reasonable gap is kept between the thrust side face and the inner wall of the cylinder barrel, and the possibility of strong contact between the thrust side face and the inner wall of the cylinder barrel is reduced.
To verify the theoretical derivation, the present example was conducted to verify experimentally the skirt asymmetric piston:
when D0 is 73mm, the relevant parameters in this validation experiment are: detonation pressure of an engine: 11MPa, engine power: 103 KW; engine displacement: 1.5L; compression ratio: 10; cylinder diameter: 73 mm; stroke: 86 mm; rotating speed: 4000 rpm; the pin aperture: 19 mm; length of the pin: 50 mm; the pin connection mode is as follows: semi-floating; eccentricity of a pin hole: 0.6 mm; connecting rod end breadth: 19 mm; connecting rod center distance: 130 mm; radius of the crankshaft: 69.5 mm; eccentricity of a crankshaft: 0.6 mm.
When D0 is 73mm, the first type line satisfies the equation x 0.00043y20.00129y-38.5, y is more than or equal to 3mm and less than or equal to 21mm, determining the shape of the first molded line of the skirt part of the piston, after determining the shape of the skirt part of the piston, respectively designing a 3D model for the asymmetric piston of the skirt part and the symmetric piston of the skirt part in the prior art, and respectively performing a skirt part surface pressure test on the asymmetric piston of the skirt part and the symmetric piston of the skirt part to obtain surface pressure test distribution diagrams of figures 3 and 4, wherein the surface pressure values from inside to outside in the figure are sequentially reduced, and the surface pressure values from inside to outside are sequentially 45-50, 40-45, 35-40, 30-35, 25-30, 20-25, 15-20, 10-15, 5-10 and 0-5, wherein the unit is: MPa.
From the final experimental data graphs it can be seen that: when the piston skirt adopts an asymmetrical form and the piston basic diameter D0 is 73mm, the first molded line of the thrust side surface of the piston skirt satisfies x 0.00043y20.00129y-D0/2, when y is more than or equal to 3mm and less than or equal to 21mm, the contact surface pressure on the whole skirt asymmetric piston is obviously less than that on the whole skirt symmetric piston, and mainly the skirt area of the skirt asymmetric piston in the contact surface pressure range of 40-50MPa is less than that of the skirt symmetric piston in the contact surface pressure range of 40-50MPa, and by arranging the piston skirt in an asymmetric form, the contact pressure between the piston thrust side skirt and the cylinder is reduced, so that the friction between the piston and the cylinder is reduced, and the combustion load of the engine is reduced.
When D0 is 77mm, the relevant parameters in this validation experiment are: detonation pressure of an engine: 11 MPa; engine power: 115 KW; engine displacement: 1.5L; compression ratio: 11.1; cylinder diameter: 77 mm; stroke: 79.82 mm; rotating speed: 4000 rpm; the pin aperture: 20 mm; length of the pin: 51 mm; the pin connection mode is as follows: semi-floating; eccentricity of a pin hole: 0.5 mm; connecting rod end breadth: 19.5 mm; connecting rod center distance: 142.15 mm; radius of the crankshaft: 76.9 mm; eccentricity of a crankshaft: 8 mm.
When D077mm, the first profile satisfies the equation x 0.00043y20.00129y-41 and y is more than or equal to 3 and less than or equal to 21, determining the shape of the first molded line of the skirt part of the piston, after determining the shape of the skirt part of the piston, respectively designing a 3D model for the asymmetric piston of the skirt part and the symmetric piston of the skirt part in the prior art, and respectively performing a skirt part surface pressure test on the asymmetric piston of the skirt part and the symmetric piston of the skirt part to obtain surface pressure test distribution diagrams of figures 5 and 6, wherein the surface pressure values from inside to outside in the graph are sequentially reduced, and the surface pressure values from inside to outside are sequentially 45-50, 40-45, 35-40, 30-35, 25-30, 20-25, 15-20, 10-15, 5-10 and 0-5, wherein the unit is: MPa.
From the final experimental data graphs it can be seen that: when the piston skirt adopts an asymmetrical form and the piston basic diameter D0 is 77mm, the first molded line of the thrust side surface of the piston skirt satisfies x 0.00043y2When y is more than or equal to 3mm and less than or equal to 21mm and is more than or equal to 0.00129y-D0/2, the integral contact surface pressure of the skirt asymmetric piston is obviously less than that of the skirt symmetric piston, the skirt area of the skirt asymmetric piston in the contact surface pressure range of 45-50MPa is less than that of the skirt symmetric piston in the contact surface pressure range of 45-50MPa, and the contact pressure between the piston thrust side skirt and the cylinder is reduced by setting the piston skirt to be in an asymmetric form, so that the friction between the piston and the cylinder is reduced, and the combustion load of the engine is reduced.
When D0 is 82mm, the relevant parameters in this validation experiment are: detonation pressure of an engine: 11 MPa; engine power: 140 KW; engine displacement: 2.0L; compression ratio: 11.3; cylinder diameter: 82 mm; stroke: 93 mm; rotating speed: 4800 rpm; the pin aperture: 21 mm; length of the pin: 53 mm; the pin connection mode is as follows: semi-floating; eccentricity of a pin hole: 0.5 mm; connecting rod end breadth: 16.8 mm; connecting rod center distance: 143.8 mm; radius of the crankshaft: 75 mm; eccentricity of a crankshaft: 6 mm.
When D0 is 82mm, the first profile satisfies the equation x 0.00043y20.00129y-43, and y is more than or equal to 3 and less than or equal to 21, determining the shape of the first molded line of the skirt part of the piston, respectively designing 3D models for the skirt part asymmetric piston and the skirt part symmetric piston in the prior art after determining the shape of the skirt part of the piston, and dividing the models into three typesThe skirt surface pressure test is performed on the skirt asymmetric piston and the skirt symmetric piston respectively to obtain surface pressure test distribution diagrams of fig. 7 and 8, wherein the surface pressure values from inside to outside in the graph are sequentially reduced, and the surface pressure values from inside to outside are sequentially 45-50, 40-45, 35-40, 30-35, 25-30, 20-25, 15-20, 10-15, 5-10 and 0-5, wherein the unit is: MPa.
From the final experimental data graphs it can be seen that: when the piston skirt adopts an asymmetrical form and the piston basic diameter D0 is 82mm, the first molded line of the thrust side surface of the piston skirt satisfies x 0.00043y 2When y is more than or equal to 3mm and less than or equal to 21mm and is more than or equal to 0.00129y-D0/2, the contact surface pressure on the whole skirt asymmetric piston is obviously smaller than that on the whole skirt symmetric piston, and the skirt area of the skirt asymmetric piston in the contact surface pressure range of 35-50MPa is smaller than that of the skirt symmetric piston in the contact surface pressure range of 35-50 MPa.
When D0 is 86mm, the relevant parameters in this validation experiment are: detonation pressure of an engine: 12 MPa; engine power: 170 KW; engine displacement: 2.0L; compression ratio: 10; cylinder diameter: 86 mm; stroke: 84.7 mm; rotating speed: 4000 rpm; the pin aperture: 22 mm; length of the pin: 62 mm; the pin connection mode is as follows: semi-floating; eccentricity of a pin hole: 0.6 mm; connecting rod end breadth: 23 mm; connecting rod center distance: 141.2 mm; radius of the crankshaft: 76 mm; eccentricity of a crankshaft: 9 mm.
When D0 is 86mm, the first profile satisfies the equation x-0.00043 y20.00129y-36.5, y is more than or equal to 3 and less than or equal to 21, determining the shape of the first molded line of the skirt part of the piston, after determining the shape of the skirt part of the piston, respectively designing a 3D model for the asymmetric piston of the skirt part and the symmetric piston of the skirt part in the prior art, and respectively carrying out skirt part surface pressure tests on the asymmetric piston of the skirt part and the symmetric piston of the skirt part to obtain surface pressure test distribution diagrams of figures 3 and 4, wherein the surface pressure values from inside to outside in the figure are sequentially reduced, and the surface pressure values from inside to outside are sequentially 45-50, 40-45, 35-40, 30-35, 25-30, 20-25, 15-20, 10-15 and 5-1 0.0 to 5, wherein the unit is: MPa.
From the final experimental data plot it can be derived: when the piston skirt adopts an asymmetrical form and the piston basic diameter D0 is 73mm, the first molded line of the thrust side surface of the piston skirt satisfies x 0.00043y20.00129y-D0/2, when y is more than or equal to 3mm and less than or equal to 21mm, the contact surface pressure on the whole skirt asymmetric piston is obviously less than that on the whole skirt symmetric piston, and mainly the skirt area of the skirt asymmetric piston in the contact surface pressure range of 45-50MPa is less than that of the skirt symmetric piston in the contact surface pressure range of 45-50MPa, and by setting the piston skirt in an asymmetric form, the contact pressure between the piston thrust side skirt and the cylinder is reduced, so that the friction between the piston and the cylinder is reduced, and the combustion load of the engine is reduced.
In the engine operation process, piston skirt thrust side and the inflation volume that the reverse thrust side was heated and is produced are different, and the inflation volume that thrust side was heated and is produced is great, and the inflation volume that the reverse thrust side was heated and is produced is less, to above-mentioned characteristic, the utility model discloses set up the first molded lines of piston skirt thrust side into satisfying equation x for 0.00043y2-0.00129y-D0/2, wherein y is more than or equal to 3mm and less than or equal to 21mm, the radian of the arc formed by the thrust side face of the piston skirt part is smaller than the radian of the arc formed by the reverse thrust side face of the piston skirt part, and the part of the thrust side face of the piston skirt part, which is reduced compared with the reverse thrust side face, can offset the heated expansion amount of the thrust side face of the piston skirt part, so that a reasonable gap is kept between the thrust side face and the inner wall of the cylinder barrel, and the four groups of experiments prove: the basic footpath D0 is in 73-86 mm's within range, the utility model discloses well piston skirt portion through above-mentioned mode of setting, the contact surface that the homoenergetic effectively reduced piston skirt portion and received presses, has further proved that piston skirt portion can reduce the contact between piston skirt portion and the cylinder through above-mentioned mode of setting to the friction that produces between piston and the cylinder and the combustion load of engine have been reduced.
It is obvious to a person skilled in the art that the invention is not restricted to details of the above-described exemplary embodiments, but that it can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.
Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.
Claims (4)
1. An asymmetric skirt piston, which comprises a piston skirt part, wherein the side surface of the piston skirt part is divided into a thrust side surface (20) and a reverse thrust side surface (30), and is characterized in that the horizontal distance between the highest point of an arc line formed by the thrust side surface and the highest point of an arc line formed by the reverse thrust side surface in the piston skirt part is a basic diameter D0 of the piston (10), a straight line of the basic diameter divides the arc line of the thrust side surface into a first molded line (21) and a second molded line (22) which are connected with each other in a front-back two-section mode, a straight line of the basic diameter divides the arc line of the reverse thrust side surface into a third molded line (31) and a fourth molded line (32) which are connected with each other in a front-back two 20.00129y-D0/2, wherein the x axis in the equation is a straight line where the basic diameter of the piston is located, the y axis in the equation is a radial center line of the piston perpendicular to the basic diameter of the piston, the value range of y in the equation is that y is larger than or equal to 3mm and smaller than or equal to 21mm, the second molded line and the fourth molded line are symmetrical about the y axis, and the first molded line and the third molded line are asymmetrical about the y axis.
2. The asymmetric skirt piston of claim 1 wherein the point on said first profile (21) and the point on said third profile (31) are each at the same distance from the x-axis and the distance L1 between the point on said first profile and the y-axis is less than the distance between the point on the third profile and the y-axis.
3. The asymmetric skirt piston of claim 1 wherein D0 is selected from the range of 73mm and 86mm, respectively, D0 mm and D3578 mm.
4. An engine comprising a skirted asymmetric piston as claimed in any of claims 1 to 3.
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| Application Number | Priority Date | Filing Date | Title |
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| CN202020726565.9U CN212376754U (en) | 2020-04-30 | 2020-04-30 | Skirt asymmetric piston and engine |
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| CN202020726565.9U CN212376754U (en) | 2020-04-30 | 2020-04-30 | Skirt asymmetric piston and engine |
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| CN212376754U true CN212376754U (en) | 2021-01-19 |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113806880A (en) * | 2021-08-04 | 2021-12-17 | 华域科尔本施密特活塞有限公司 | Method for designing plug skirt molded line suitable for large-cylinder-matching clearance piston |
-
2020
- 2020-04-30 CN CN202020726565.9U patent/CN212376754U/en active Active
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113806880A (en) * | 2021-08-04 | 2021-12-17 | 华域科尔本施密特活塞有限公司 | Method for designing plug skirt molded line suitable for large-cylinder-matching clearance piston |
| CN113806880B (en) * | 2021-08-04 | 2024-01-05 | 华域科尔本施密特活塞有限公司 | Piston skirt profile design method suitable for large cylinder matching gap |
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