CN109519298B

CN109519298B - Combined piston

Info

Publication number: CN109519298B
Application number: CN201710846327.4A
Authority: CN
Inventors: 强莉莉
Original assignee: Individual
Current assignee: Individual
Priority date: 2017-09-19
Filing date: 2017-09-19
Publication date: 2021-04-23
Anticipated expiration: 2037-09-19
Also published as: CN109519298A

Abstract

The invention discloses a combined piston which comprises a piston upper part, a piston lower part and a connecting piece, wherein the bottom of the piston upper part is provided with at least two upper sections which are arranged at intervals and symmetrically, the top of the piston lower part is provided with a lower section corresponding to the upper sections, the upper sections and the lower sections are matched and pressed, and the piston upper part and the piston lower part are connected through the connecting piece in a fastening manner. The invention has the advantages of easy molding, low manufacturing cost, capability of improving the use reliability of the diesel engine and the like.

Description

Combined piston

Technical Field

The invention mainly relates to the technical field of internal combustion engines, in particular to a combined piston.

Background

The piston is a key part and is one of key parts for promoting the emission upgrade, the steel structure piston replaces an aluminum structure piston to be an important means for meeting the emission requirement, the all-steel piston is forged or cast to form, but the all-steel piston has large weight, large forming process difficulty and high cost, meanwhile, an annular inner cooling oil cavity arranged for reducing the temperature of the piston head and an annular groove has poor processing manufacturability, large processing difficulty, low efficiency and high cost, the piston is formed around the piston, the heat load of the piston head is reduced, the weight of the piston is reduced, the reliability of the piston is improved, and various solutions are provided at home and abroad.

The prior art provides good thinking and methods for forming of steel pistons and machining of internal cooling oil ducts, and the technical schemes mainly have the following problems that firstly, the steel pistons are high in machining cost, secondly, the machining difficulty is high, thirdly, the technical reliability is insufficient, and the like, and particularly, the piston blank is high in production cost and has the common defect of various schemes. For example, the integral piston forming method disclosed in patent No. CN200480018072.3 has the disadvantages of high forging cost of blank, high difficulty in machining oil passages and low machining efficiency. The integral piston forming method related to patent number CN103124841A has the defects that the blank forging cost is high, welding flashes exist in an oil passage of a piston after friction welding, and oxide scale particles on the surfaces of the flashes are brought into lubricating oil after being repeatedly oscillated and impacted in the piston moving process, so that great risk is brought to the operation of a diesel engine. The integral piston forming method related to the patent number CN200880122140.9 has the defects that the blank forging cost is high, the thermal stress of the corresponding area of the piston top exhaust valve is large, and the laser welding seam has a larger failure risk than a non-welding area. The patent No. CN1685140A relates to a method for forming an integral piston, the piston is composed of an upper part and a lower part, the upper part of the piston comprises a ring rib, a concave cavity combustion chamber and a cooling channel, and a plurality of radial support ribs are arranged in the cooling channel; the lower part of the piston comprises a bearing rib with an annular and full-circular connecting surface, the bearing rib is connected to a piston pin boss, and after the upper part and the lower part of the piston are processed, the upper ring rib and the bearing rib at the lower part of the piston are connected in a non-detachable mode through welding or brazing; the method has the defects that the upper part and the lower part of the piston are relatively complex in structure and high in comprehensive forging cost, a possible welding method is friction welding according to a legend, welding flashes exist after the friction welding, and oxide scale particles on the surfaces of the flashes are likely to be peeled off in the piston moving process and fall into lubricating oil, so that great risk is brought to the operation of a diesel engine; if laser, electron beam welding, brazing and the like are adopted, the length of the piston can be increased and the weight of the piston can be increased under the influence of the arrangement of the welding seam.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide a combined piston which is low in manufacturing cost, easy to form and capable of improving the use reliability of a diesel engine.

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

the utility model provides a combined piston, includes piston upper portion, piston lower part and connecting piece, the bottom on piston upper portion is equipped with two at least last sections that are interval symmetrical arrangement, the top of piston lower part be equipped with go up the lower section that the section corresponds, go up the section and compress tightly with lower section cooperation, piston upper portion and piston lower part pass through connecting piece fastening connection.

As a further improvement of the above technical solution:

the bottom on piston upper portion is equipped with the pinhole section, go up the section setting and be equipped with down the pinhole section in last pinhole section open-ended both sides, the top of piston lower part is equipped with down the pinhole section, the section sets up in lower pinhole section open-ended both sides down, go up section and section welded connection down, and go up the pinhole section and close with lower pinhole section enclosure and form the pinhole.

The connecting piece comprises four screw rods, the four screw rods penetrate through the periphery of the lower part of the piston in a rectangular shape, and the rod body extending out of the lower part of the piston is in threaded connection with the upper part of the piston.

The upper part of the piston is provided with an annular inner cooling oil duct, the upper pin hole section is provided with an oil hole communicated with the annular inner cooling oil duct, and two diagonally distributed screw rods are provided with rod body oil ducts communicated with the oil hole.

The connecting piece comprises four studs and four locking screw caps, the four studs are welded on the periphery of the upper part of the piston in a rectangular shape, a column body extending out of the upper part of the piston penetrates through the lower part of the piston, and the four locking screw caps are in threaded connection with the studs and lock the lower part of the piston.

An annular inner cooling oil duct is formed in the upper portion of the piston, oil holes communicated with the annular inner cooling oil duct are formed in the upper pin hole section, and a column body oil duct communicated with the oil holes is formed in two diagonally distributed studs.

And when the upper part of the piston is connected with the lower part of the piston, the outer walls of two sides of the lower pin hole section of the lower part of the piston are tightly attached to the limiting clips.

The upper section and the lower section are arranged to be flat surfaces.

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

the combined piston comprises a piston upper part, a piston lower part and a connecting piece, wherein the bottom of the piston upper part is provided with at least two upper sections which are arranged at intervals and symmetrically, the top of the piston lower part is provided with a lower section corresponding to the upper sections, the upper sections and the lower sections are matched and pressed, and the piston upper part and the piston lower part are connected through the connecting piece in a fastening manner. In the structure, at least two pairs of upper sections which are arranged symmetrically at intervals are arranged at the bottom of the upper part of the piston, lower sections corresponding to the upper sections are arranged at the top of the lower part of the piston, the upper sections and the lower sections are matched and pressed, so that pressing positions which are arranged symmetrically at intervals are formed, and the upper part of the piston and the lower part of the piston are fastened and connected together by using a connecting piece; the special section position and section structure make the structure simple, which is beneficial to processing, assembling and positioning, and improves the processing efficiency.

Drawings

Fig. 1 is a front view schematically showing the structure of a combined piston according to embodiment 1 of the present invention.

Fig. 2 is a side view of the composite piston of embodiment 1 of the present invention.

Fig. 3 is a schematic bottom view of the composite piston of embodiment 1 of the present invention.

Fig. 4 is a schematic side sectional view of a part of a combined piston in accordance with embodiment 1 of the present invention.

Fig. 5 is a front view schematically showing the structure of the upper part of the piston in embodiment 1 of the composite piston of the present invention.

Fig. 6 is a schematic side view of the upper portion of the piston in embodiment 1 of the composite piston of the present invention.

Fig. 7 is a schematic bottom view of the upper portion of the piston in embodiment 1 of the composite piston of the present invention.

Fig. 8 is a front view schematically showing the structure of the lower portion of the piston in embodiment 1 of the composite piston of the present invention.

Fig. 9 is a side view schematically showing the structure of the lower portion of the piston in embodiment 1 of the composite piston of the present invention.

Fig. 10 is a schematic bottom view of the lower portion of the piston in embodiment 1 of the composite piston of the present invention.

Fig. 11 is a schematic side sectional view of a portion of a composite piston of embodiment 2 of the present invention.

The reference numerals in the figures denote:

1. the upper part of the piston; 11. upper fracture surface; 12. an upper pin hole section; 121. an oil hole; 13. an annular internal cooling oil duct; 14. a limiting clip; 2. a piston lower part; 21. lower section; 22. a lower pin hole section; 3. a connecting member; 31. a screw; 311. a shaft body oil passage; 32. a stud; 321. a column body oil passage; 33. locking a screw cap; 4. a pin hole.

Detailed Description

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

Example 1:

fig. 1 to 10 show a first embodiment of the combined piston of the present invention, which comprises a piston upper part 1, a piston lower part 2 and a connecting piece 3, wherein the bottom of the piston upper part 1 is provided with at least two upper sections 11 which are symmetrically arranged at intervals, the top of the piston lower part 2 is provided with a lower section 21 corresponding to the upper section 11, the upper section 11 and the lower section 21 are matched and pressed, and the piston upper part 1 and the piston lower part 2 are tightly connected through the connecting piece 3. In the structure, two pairs of upper sections 11 which are symmetrically arranged at intervals are arranged at the bottom of the upper part 1 of the piston, lower sections 21 which correspond to the upper sections 11 are arranged at the top of the lower part 2 of the piston, the upper sections 11 and the lower sections 21 are matched and pressed, namely, pressing positions which are symmetrically arranged at intervals are formed, and the upper part 1 of the piston and the lower part 2 of the piston are fastened and connected together by using a connecting piece 3; the special section position and section structure make the structure simple, which is beneficial to processing, assembling and positioning, and improves the processing efficiency.

The bottom of piston upper portion 1 is equipped with last pinhole section 12, goes up section 11 and sets up in last pinhole section 12 open-ended both sides, and the top of piston lower part 2 is equipped with down pinhole section 22, and lower section 21 sets up in the both sides of lower pinhole section 22 open-ended, goes up section 11 and lower section 21 welded connection, and goes up pinhole section 12 and the closed pinhole 4 that forms of lower pinhole section 22 enclosure. In the structure, the upper section 11 and the lower section 21 are arranged at the position of the pin hole 4, so that the section positions are arranged outside a main bearing area when the piston pin works, and the failure risk is reduced.

In this embodiment, the section divides the pin hole 4 into two sections, so the lower portion 2 of the piston can be an aluminum piston lower portion, and the upper portion 1 of the piston can be a steel piston upper portion, so that the steel piston upper portion plays a main bearing role through the upper pin hole section 12, and the aluminum piston lower portion is beneficial to reducing the piston compression height and the piston weight, and promoting the improvement of the power density of the internal combustion engine while realizing a large-capacity internal cooling oil cavity.

In this embodiment, the connecting member 3 includes four screws 31, the four screws 31 are arranged on the periphery of the piston lower portion 2 in a rectangular shape, and the rod body extending out of the piston lower portion 2 is in threaded connection with the piston upper portion 1. In the structure, the upper part 1 of the piston and the lower part 2 of the piston are connected by four screw rods 31, and the upper part 1 of the piston is forged or cast, so that the lower part 2 of the piston is effectively supported while bearing the high combustion detonation pressure of a cylinder; the four screw rods 31 are symmetrically distributed on two sides of the piston pin hole 4 to form a rectangular structure similar to a bearing seat, and the structure is simple and reliable in assembly.

In this embodiment, the upper portion 1 of the piston is provided with an annular inner cooling oil duct 13, the upper pin hole section 12 is provided with an oil hole 121 communicated with the annular inner cooling oil duct 13, and two diagonally distributed screws 31 are provided with rod body oil ducts 311 communicated with the oil hole 121. In the structure, the oil hole 121 of the upper pin hole section 12 is communicated with the annular inner cooling oil duct 13, so that the cooling of the pin hole 4 and the piston pin is enhanced, and the risk of locking the piston pin in the pin hole 4 is reduced; and the screw 31 is communicated with the oil hole 121 through the rod body oil passage 311, namely, the connecting position of the piston upper part 1 and the piston lower part 2 is cooled, and the service life of the screw is prolonged.

In this embodiment, the outer walls of the two sides of the upper pin hole section 12 of the upper piston part 1 are provided with the limiting clips 14, and when the upper piston part 1 is connected with the lower piston part 2, the outer walls of the two sides of the lower pin hole section 22 of the lower piston part 2 are tightly attached to the limiting clips 14. In this structure, the both sides outer wall of round pin hole section 12 is equipped with spacing checkpost 14 on piston upper portion 1, and two round pin hole sections 12 correspond totally four spacing checkposts 14, and four spacing checkposts 14 have formed complete draw-in groove structure for when the installation fix a position piston lower part 2, further improved the convenience and the accuracy nature of installation.

In this embodiment, the upper section 11 and the lower section 21 are provided as flat surfaces. The straight surface is easy to process, the precision is high, and the assembly precision of the integral piston is facilitated.

Example 2:

fig. 11 shows a second embodiment of the composite piston of the invention, which is essentially identical to embodiment 1, except that: in this embodiment, the connecting member 3 includes four studs 32 and four locking screw caps 33, the four studs 32 are welded to the periphery of the piston upper portion 1 in a rectangular shape, a shaft extending out of the piston upper portion 1 penetrates through the piston lower portion 2, and the four locking screw caps 33 are in threaded connection with the studs 32 and lock the piston lower portion 2. In the structure, four studs 32 are welded on the upper part 1 of the piston, the lower part 2 of the piston is sleeved on the four studs 32, four locking screw caps 33 are connected with the studs 32 in a threaded manner and are used for locking the lower part 2 of the piston, and the upper part 1 of the piston is forged or cast, so that the lower part 2 of the piston is effectively supported while bearing the high combustion detonation pressure of a cylinder; four studs 32 are distributed on two sides of the piston pin hole 4 and are symmetrically arranged to form a rectangular structure similar to a bearing seat, and the structure is simple and reliable in assembly.

In this embodiment, the upper portion 1 of the piston is provided with an annular inner cooling oil duct 13, the upper pin hole section 12 is provided with oil holes 121 communicated with the annular inner cooling oil duct 13, and two studs 32 distributed diagonally are provided with shaft oil ducts 321 communicated with the oil holes 121. In the structure, the oil hole 121 of the upper pin hole section 12 is communicated with the annular inner cooling oil duct 13, so that the cooling of the pin hole 4 and the piston pin is enhanced, and the risk of locking the piston pin in the pin hole 4 is reduced; and the stud 32 is communicated with the oil hole 121 through the cylinder oil passage 321, namely, the connecting position of the upper part 1 and the lower part 2 of the piston is cooled, and the service life of the piston is prolonged.

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. A modular piston, characterized by: comprises a piston upper part (1), a piston lower part (2) and a connecting piece (3), the bottom of the upper part (1) of the piston is provided with at least two upper sections (11) which are symmetrically arranged at intervals, the top of the lower part (2) of the piston is provided with a lower section (21) corresponding to the upper section (11), the upper section (11) and the lower section (21) are matched and pressed, the upper part (1) and the lower part (2) of the piston are tightly connected through a connecting piece (3), the bottom of the upper part (1) of the piston is provided with an upper pin hole section (12), the upper section (11) is arranged at two sides of the opening of the upper pin hole section (12), the top of the lower part (2) of the piston is provided with a lower pin hole section (22), the lower section (21) is arranged at two sides of the opening of the lower pin hole section (22), the upper section (11) and the lower section (21) are matched and pressed, and the upper pin hole section (12) and the lower pin hole section (22) are enclosed to form a pin hole (4).

2. The composite piston of claim 1, further comprising: the connecting piece (3) comprises four screw rods (31), the four screw rods (31) penetrate through the periphery of the lower part (2) of the piston in a rectangular shape, and a rod body extending out of the lower part (2) of the piston is in threaded connection with the upper part (1) of the piston.

3. The composite piston of claim 2, further comprising: an annular inner cooling oil duct (13) is formed in the upper portion (1) of the piston, an oil hole (121) communicated with the annular inner cooling oil duct (13) is formed in the upper pin hole section (12), and the oil hole (121) is communicated with a rod body oil duct (311).

4. The composite piston of claim 1, further comprising: the connecting piece (3) comprises four studs (32) and four locking screw caps (33), the four studs (32) are welded on the periphery of the upper piston part (1) in a rectangular mode, a cylinder body extending out of the upper piston part (1) penetrates through the lower piston part (2), and the four locking screw caps (33) are in threaded connection with the studs (32) and lock the lower piston part (2).

5. The composite piston of claim 4, wherein: an annular inner cooling oil duct (13) is formed in the upper portion (1) of the piston, an oil hole (121) communicated with the annular inner cooling oil duct (13) is formed in the upper pin hole section (12), and a column oil duct (321) communicated with the oil hole (121) is formed in the stud (32).

6. The composite piston of any one of claims 1 to 5, further comprising: and the outer walls of two sides of the lower pin hole section (22) of the piston lower part (2) are tightly attached to the limiting clips (14) when the upper piston part (1) is connected with the lower piston part (2).

7. The composite piston of any one of claims 1 to 5, further comprising: the upper section (11) and the lower section (21) are arranged to be flat surfaces.

8. The composite piston of claim 6, further comprising: the upper section (11) and the lower section (21) are arranged to be flat surfaces.