CN113431698A

CN113431698A - Split combined type heat insulation piston

Info

Publication number: CN113431698A
Application number: CN202010208208.8A
Authority: CN
Inventors: 强哲菲; 强莉莉
Original assignee: Individual
Current assignee: Individual
Priority date: 2020-03-23
Filing date: 2020-03-23
Publication date: 2021-09-24
Anticipated expiration: 2040-03-23
Also published as: CN113431698B

Abstract

The invention discloses a split combined type heat insulation piston which comprises a split type piston head and a split type piston skirt part, wherein an annular oil cavity and a central oil cavity are formed in the piston head, a supporting rib is arranged between the annular oil cavity and the central oil cavity, a heat insulation cavity channel for reducing heat transfer between the piston head and the piston skirt part is formed in the supporting rib, and the piston head and the piston skirt part are connected through bolts or welding. The heat insulation piston has the advantages of reliable structure, capability of reducing the temperature of the skirt part of the piston, capability of reducing the clearance of the cylinder and capability of reducing the weight of the piston.

Description

Split combined type heat insulation piston

Technical Field

The invention mainly relates to a forming technology of a steel piston of an internal combustion engine, in particular to a split composite heat-insulation piston.

Background

When the internal combustion engine runs, the piston does reciprocating motion at the upper and lower dead points, is a power conversion and output mechanism and has the main function of converting heat energy into mechanical work, the instantaneous speed of the piston changes greatly in the motion process, the maximum reciprocating inertia force of the piston reaches hundreds to thousands of times of the mass of the piston according to measurement and calculation, the inertia force causes the internal combustion engine to vibrate, the mechanical load and abrasion of a piston pin, a crankshaft and a connecting rod are increased, and the reduction of the mass of the piston is very important; meanwhile, the piston is arranged in the cylinder sleeve, so that the fit clearance between the piston skirt and the cylinder sleeve is reduced, the oil consumption is reduced, and the noise is reduced.

With the continuous improvement of the strengthening degree of the internal combustion engine, the internal combustion engine has compact structure, higher detonation pressure and higher power, and becomes the direction of continuously improving the performance of the internal combustion engine, so that in order to meet the requirements of higher mechanical load and thermal load, the piston of the high-power internal combustion engine adopts more combined structures which are connected by steel top aluminum skirts and bolts, for example, the publication No. CN110469421A discloses a combined structure, and a new idea is provided for the application of the combined piston.

The existing split composite piston has the following defects and shortcomings: 1. the skirt part of the piston with the steel top and aluminum skirt structure in the prior art is made of aluminum alloy, the coefficient of thermal expansion of the aluminum alloy is large, and the clearance of a matched cylinder of the piston is large. 2. Partial heat generated by the piston combustion chamber is transferred to the skirt part through the bearing surface of the steel top connected with the aluminum skirt part, the mechanical strength of the skirt part is reduced due to the temperature rise, the weight of the skirt part of the piston is increased to meet the mechanical load requirement of the skirt part, and the motion load of the piston connecting rod group is improved. 3. The thermal expansion coefficient of the aluminum alloy is much higher than that of the bolt material, the temperature of the steel top, the aluminum skirt and the bolt of the piston is increased when the internal combustion engine works, the axial thermal expansion amount of the aluminum alloy is larger than that of the alloy steel, the residual pretightening force of the bolt connection is reduced, and the failure risk of the bolt connection is increased.

Disclosure of Invention

The invention aims to solve the technical problem of overcoming the defects of the prior art and provide the split composite heat-insulating piston which has a reliable structure, can reduce the temperature of the skirt part of the piston, can reduce the clearance of a matched cylinder and can reduce the weight of the piston.

In order to solve the technical problems, the invention adopts the following technical scheme:

the utility model provides a components of a whole that can function independently combined type piston that insulates against heat, includes split type piston head and piston skirt portion, be equipped with annular oil pocket and central oil pocket on the piston head, support rib has between annular oil pocket and the central oil pocket, be equipped with the thermal-insulated chamber way that is used for reducing heat transfer between piston head and the piston skirt portion on the support rib, piston head and piston skirt portion pass through bolted connection.

As a further improvement of the above technical solution:

the top of the piston skirt is provided with a positioning bulge, and the bottom of the piston head is matched and positioned with the positioning bulge.

And an oil passing groove for communicating the annular oil cavity with the central oil cavity is formed in the top of the piston skirt.

And oil passing channels are arranged between the annular oil cavity and the heat insulation cavity channel and between the heat insulation cavity channel and the central oil cavity.

The heat insulation cavity channel is arranged in plurality in the radial direction at the piston head.

The heat insulation cavity is communicated with the annular oil cavity and the central oil cavity.

The supporting rib is also provided with a through hole for communicating the annular oil cavity with the central oil cavity.

The heat insulation cavity is provided with an open slot, the opening of the heat insulation cavity faces the piston skirt, and the opening of the heat insulation cavity is provided with a cavity compensating plate.

The piston head includes split type last head and lower head, thermal-insulated chamber says and sets up on lower head, thermal-insulated chamber says and sets up to the open slot, and the opening that thermal-insulated chamber said is towards last head, go up head and lower head formation straight face welding, the opening that thermal-insulated chamber said and the straight face cooperation formation closed thermal-insulated chamber of last head say, head and piston skirt portion under the bolted connection.

The piston is characterized in that a heat insulation pad is arranged at the bottom of the head of the piston and extends to a support rib from an annular oil cavity, the heat insulation cavity channel comprises an upper half cavity and a lower half cavity, the lower half cavity is arranged on the heat insulation pad and communicated with the annular oil cavity, the upper half cavity is arranged on the support rib, and an oil passing hole communicated with the upper half cavity, the lower half cavity and the central oil cavity is formed in the support rib.

Compared with the prior art, the invention has the advantages that:

the split combined type heat insulation piston comprises a split type piston head and a split type piston skirt, wherein an annular oil cavity and a central oil cavity are formed in the piston head, a supporting rib is arranged between the annular oil cavity and the central oil cavity, a heat insulation cavity channel used for reducing heat transfer between the piston head and the piston skirt is formed in the supporting rib, and the piston head and the piston skirt are connected through bolts. In the structure, a heat insulation cavity channel is arranged on a support rib, and the heat insulation cavity channel can bear the gas pressure of the head part and block the heat of the head part of the piston from being transferred to the skirt part of the piston; lubricating oil can pass through the heat insulation cavity, so that the heat exchange area can be increased, more heat can be taken away, and the temperature of the combustion chamber can be reduced; the heat insulation cavity, the annular oil cavity and the central oil cavity form a multi-cavity structure, the structure is simple, the heat exchange area with lubricating oil is increased, the heat transfer passage at the head of the piston is reduced, the heat of the head of the piston is blocked from being transferred to the skirt part of the piston, the temperature of the skirt part of the piston is reduced, the clearance of a cylinder is reduced, and the heat load of the head of the plug is also reduced; when the internal combustion engine runs, the temperature of the piston skirt part is obviously reduced compared with the prior art, and the reduction of the strength of the piston skirt part is reduced, so that higher mechanical load can be borne, the weight reduction of the piston skirt part and a piston is facilitated, and the motion inertia of a piston connecting rod group can be reduced; the lower temperature of the piston skirt is beneficial to the use of the elastic sleeve made of low expansion alloy for bolt connection, and the residual pretightening force of the bolt connection is improved.

Drawings

Fig. 1 is a schematic front view of embodiment 1 of the present invention.

Fig. 2 is a front view schematically showing the structure of the piston head in embodiment 1 of the present invention.

Fig. 3 is a schematic front view of embodiment 2 of the present invention.

Fig. 4 is a front view schematically showing the structure of the piston head in embodiment 2 of the present invention.

Fig. 5 is a schematic top view of embodiment 2 of the present invention.

Fig. 6 is a schematic front view of embodiment 3 of the present invention.

Fig. 7 is a front view schematically showing the structure of the piston head in embodiment 3 of the present invention.

Fig. 8 is a schematic top view of embodiment 3 of the present invention.

Fig. 9 is a schematic front view of embodiment 4 of the present invention.

Fig. 10 is a front view schematically showing the structure of the upper head part in embodiment 4 of the present invention.

Fig. 11 is a front view schematically showing the structure of the lower head part in embodiment 4 of the present invention.

Fig. 12 is a schematic front view of embodiment 5 of the present invention.

Fig. 13 is a front view schematically showing the structure of the piston head in embodiment 5 of the present invention.

Fig. 14 is a schematic front view of embodiment 6 of the present invention.

Fig. 15 is a schematic front view of the thermal pad according to example 6 of the present invention.

The reference numerals in the figures denote:

1. a piston head; 11. an annular oil chamber; 12. a central oil chamber; 13. a support rib; 131. an oil passing hole; 14. a heat-insulating cavity; 141. an upper cavity; 142. a lower cavity; 15. a through hole; 16. a cavity compensation plate; 17. an upper head portion; 18. a lower head portion; 19. a heat insulating pad; 2. a piston skirt; 21. positioning the projection; 22. an oil passing groove; 3. a bolt; 31. an elastic sleeve; 4. and an oil passing channel.

Detailed Description

The invention will be described in further detail below with reference to the drawings and specific examples.

Example 1:

fig. 1 and 2 show a first embodiment of a split composite heat-insulating piston according to the invention, which includes a split piston head 1 and a split piston skirt 2, wherein an annular oil chamber 11 and a central oil chamber 12 are arranged on the piston head 1, a support rib 13 is arranged between the annular oil chamber 11 and the central oil chamber 12, a heat-insulating channel 14 for reducing heat transfer between the piston head 1 and the piston skirt 2 is arranged on the support rib 13, and the piston head 1 and the piston skirt 2 are connected by a bolt 3. In the structure, a heat insulation cavity channel 14 is arranged on a support rib 13, and the heat insulation cavity channel 14 can bear the gas pressure of the head part and block the heat of the head part 1 of the piston from being transferred to the skirt part 2 of the piston; lubricating oil can pass through the heat insulation cavity 14, so that the heat exchange area can be increased, more heat can be taken away, and the temperature of the combustion chamber can be reduced; the heat insulation cavity channel 14, the annular oil cavity 11 and the central oil cavity 12 form a multi-cavity structure, the structure is simple, the heat exchange area with lubricating oil is increased, the heat transfer passage of the piston head part 1 is reduced, the heat transfer of the piston head part 1 to the piston skirt part 2 is blocked, the temperature of the piston skirt part 2 is reduced, the clearance of a cylinder is reduced, and meanwhile, the heat load of the plug head part 1 is also reduced; when the internal combustion engine runs, the temperature of the piston skirt part 2 is obviously reduced compared with the prior art, and the strength reduction of the piston skirt part 2 is reduced, so that higher mechanical load can be borne, the weight reduction of the piston skirt part 2 and a piston is facilitated, and the motion inertia of a piston connecting rod group can be reduced; the lower temperature of the piston skirt part 2 is beneficial to the use of the elastic sleeve 31 adopting low expansion alloy for the connection of the bolt 3, and the residual pretightening force of the connection of the bolt 3 is improved.

In this embodiment, the top of the piston skirt 2 is provided with a positioning protrusion 21, and the bottom of the piston head 1 is positioned in cooperation with the positioning protrusion 21. In the structure, the piston head 1 is matched and positioned with the positioning protrusion 21, so that the stability of the installation position of the piston head 1 and the piston skirt 2 in the working process is facilitated.

In the present embodiment, the top of the piston skirt 2 is provided with an oil passing groove 22 for communicating the annular oil chamber 11 and the central oil chamber 12. In the structure, the heat insulation cavity channel 14 is equivalent to an air cavity and can bear the air pressure of the piston head 1, the heat of the piston head 1 is blocked from being transferred to the piston skirt part 2, and the annular oil cavity 11 and the central oil cavity 12 form through oil reciprocating flow through the oil through groove 22.

In this embodiment, the heat insulation cavity 14 is an open slot, the opening of the heat insulation cavity 14 faces the piston skirt 2, and the opening of the heat insulation cavity 14 is provided with a cavity compensating plate 16. The open slot makes the forming more simple and convenient, and the cavity compensating plate 16 makes the heat insulation cavity 14 form a closed loop, which improves the heat insulation performance.

Example 2:

fig. 3 to 5 show a second embodiment of the split composite insulated piston of the present invention, which is substantially the same as embodiment 1 except that: in this embodiment, oil passing channels 4 are arranged between the annular oil chamber 11 and the heat insulation channel 14 and between the heat insulation channel 14 and the central oil chamber 12. In this structure, heat-insulating chamber way 14 still can realize the heat exchange through oil through passageway 4 when acting as the air chamber, can bear piston head 1 gas pressure, and the heat of separation piston head 1 can also increase heat exchange area, take away more heats when to the transmission of piston skirt portion 2, reduces the combustion chamber temperature.

Example 3:

fig. 6-8 illustrate a third embodiment of a split compound insulated piston of the present invention, which is substantially identical to embodiment 2 except that: in the present embodiment, the plurality of heat insulation channels 14 are provided in the piston head 1 in the radial direction. The heat insulation cavity channels 14 are provided with a plurality of cavities, so that a multi-cavity structure is further formed, on one hand, the heat insulation effect is improved, on the other hand, the multi-cavity structure is also beneficial to connecting and arranging the bolts 3 in each cavity, and conditions are created for improving the connection rationality of the bolts 3.

Example 4:

fig. 9 to 11 show a fourth embodiment of a split compound insulated piston according to the invention, which is substantially identical to embodiment 1, except that: in the embodiment, the piston head 1 comprises an upper head 17 and a lower head 18 which are separated, the heat insulation cavity channel 14 is arranged on the lower head 18, the heat insulation cavity channel 14 is arranged to be an open slot, the opening of the heat insulation cavity channel 14 faces the upper head 17, the upper head 17 and the lower head 18 form straight surface welding, the opening of the heat insulation cavity channel 14 and the straight surface of the upper head 17 are matched to form a closed heat insulation cavity channel 14, and the bolt 3 is connected with the lower head 18 and the piston skirt 2. In this structure, piston head 1 comprises split type last head 17 and lower head 18, goes up head 17 and lower head 18 and forms the straight face welding for the opening of thermal-insulated chamber way 14 and the straight face cooperation of last head 17 form closed thermal-insulated chamber way 14 and improved thermal-insulated performance, and, head 18 and piston skirt portion 2 under the bolt 3 connection, whole head 18 provides the connection basis for bolt 3 promptly, has improved whole joint strength.

In this embodiment, the heat insulation channel 14 communicates the annular oil chamber 11 and the central oil chamber 12. In the structure, the heat insulation cavity channel 14 is directly communicated with the annular oil cavity 11 and the central oil cavity 12, and can form oil-passing reciprocating flow while bearing the gas pressure of the piston head 1 and blocking the heat of the piston head 1 from being transferred to the piston skirt 2, thereby increasing the heat exchange area with lubricating oil.

Example 5:

fig. 12 and 13 show a fifth embodiment of a split compound insulated piston of the present invention, which is substantially the same as embodiment 1 except that: in this embodiment, the support rib 13 is further provided with a through hole 15 for communicating the annular oil chamber 11 and the central oil chamber 12. In the embodiment, a multi-cavity porous structure is formed by the heat insulation cavity channel 14 and the through holes 15, the heat insulation cavity channel 14 bears the gas pressure of the piston head part 1, the heat of the piston head part 1 is prevented from being transferred to the piston skirt part 2, the through holes 15 form oil passing reciprocating flow, and the heat exchange area with lubricating oil is increased.

Example 6:

fig. 14 and 15 show a sixth embodiment of a split compound insulated piston of the present invention, which is substantially the same as embodiment 1 except that: in this embodiment, the bottom of the piston head 1 is provided with a heat insulation pad 19, the heat insulation pad 19 extends from the annular oil chamber 11 to the support rib 13, the heat insulation channel 14 includes an upper half chamber 141 and a lower half chamber 142, the lower half chamber 142 is disposed on the heat insulation pad 19 and communicated with the annular oil chamber 11, the upper half chamber 141 is disposed on the support rib 13, and the support rib 13 is provided with an oil through hole 131 communicating the upper half chamber 141, the lower half chamber 142 and the central oil chamber 12. In the structure, the piston head 1 and the heat insulation pad 19 are in interference fit, and the expansion coefficient of the low-expansion alloy heat insulation pad 19 is lower than that of alloy steel, so that the position of the heat insulation pad 19 in the groove of the piston head 1 is stable; the heat insulation pad 19 not only ensures the oil passing of the annular oil cavity 11 and the central oil cavity 12 of the piston head 1 through the heat insulation cavity channel 14 and the oil passing hole 131, but also has low heat conductivity coefficient of the low-expansion alloy heat insulation pad 19, further reduces the heat transfer from the piston head 1 to the piston skirt 2, and is beneficial to the reduction of the cylinder matching clearance.

Although the present invention has been described with reference to the preferred embodiments, it is not intended to be limited thereto. Those skilled in the art can make numerous possible variations and modifications to the present invention, or modify equivalent embodiments to equivalent variations, without departing from the scope of the invention, using the teachings disclosed above. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical spirit of the present invention should fall within the protection scope of the technical scheme of the present invention, unless the technical spirit of the present invention departs from the content of the technical scheme of the present invention.

Claims

1. The utility model provides a components of a whole that can function independently combined type piston that insulates against heat, includes split type piston head (1) and piston skirt portion (2), be equipped with annular oil pocket (11) and central oil pocket (12) on piston head (1), have between annular oil pocket (11) and central oil pocket (12) and support rib (13), its characterized in that: the support rib (13) is provided with a heat insulation cavity (14) for reducing heat transfer between the piston head (1) and the piston skirt (2), and the piston head (1) and the piston skirt (2) are connected through bolts (3) or welding.

2. The split composite insulated piston of claim 1, wherein: the top of the piston skirt portion (2) is provided with a positioning bulge (21), and the bottom of the piston head portion (1) is matched and positioned with the positioning bulge (21).

3. The split composite heat-insulating piston according to claim 1 or 2, wherein: and an oil passing groove (22) for communicating the annular oil chamber (11) with the central oil chamber (12) is formed in the top of the piston skirt part (2).

4. The split composite heat-insulating piston according to claim 1 or 2, wherein: and oil passing channels (4) are arranged between the annular oil cavity (11) and the heat insulation cavity channel (14) and between the heat insulation cavity channel (14) and the central oil cavity (12).

5. The split composite insulated piston of claim 4, wherein: the heat insulation cavity (14) is arranged in plurality in the radial direction of the piston head (1).

6. The split composite heat-insulating piston according to claim 1 or 2, wherein: the heat insulation cavity channel (14) is communicated with the annular oil cavity (11) and the central oil cavity (12).

7. The split composite heat-insulating piston according to claim 1 or 2, wherein: the supporting rib (13) is also provided with a through hole (15) for communicating the annular oil cavity (11) with the central oil cavity (12).

8. The split composite heat-insulating piston according to claim 1 or 2, wherein: the heat insulation cavity channel (14) is set to be an open slot, the opening of the heat insulation cavity channel (14) faces the piston skirt portion (2), and a cavity channel compensation plate (16) is arranged at the opening of the heat insulation cavity channel (14).

9. The split composite heat-insulating piston according to claim 1 or 2, wherein: piston head (1) is including split type last head (17) and lower head (18), thermal-insulated chamber way (14) set up under on head (18), thermal-insulated chamber way (14) set up to the open slot, and the opening of thermal-insulated chamber way (14) is towards last head (17), go up head (17) and lower head (18) and form the straight face welding, the opening of thermal-insulated chamber way (14) and the straight face cooperation of last head (17) form closed thermal-insulated chamber way (14), lower head (18) and piston skirt portion (2) are connected in bolt (3).

10. The split composite heat-insulating piston according to claim 1 or 2, wherein: piston head (1) bottom is equipped with heat insulating mattress (19), heat insulating mattress (19) extend to support rib (13) by annular oil pocket (11), heat-insulating chamber way (14) are including first chamber (141) and second chamber (142), second chamber (142) set up on heat insulating mattress (19) and communicate annular oil pocket (11), first chamber (141) set up on supporting rib (13), be provided with oil passing hole (131) of first chamber (141), second chamber (142) and central oil pocket (12) of intercommunication on supporting rib (13).