CN106640401B

CN106640401B - Steel piston for diesel engine and production process thereof

Info

Publication number: CN106640401B
Application number: CN201710001228.6A
Authority: CN
Inventors: 张元侃; 袁晓麒; 沈天宇
Original assignee: Wuxi Huaxing Mechanical And Electrical Manufacture Co ltd
Current assignee: Wuxi Huaxing Mechanical And Electrical Manufacture Co ltd
Priority date: 2017-01-03
Filing date: 2017-01-03
Publication date: 2022-10-25
Anticipated expiration: 2037-01-03
Also published as: CN106640401A

Abstract

The invention discloses a steel piston for a diesel engine and a production process thereof, the steel piston comprises a piston seat, 2 same semi-annular oil duct baffles and a pair of piston skirts symmetrically arranged along the axis of the piston seat, the head of the piston seat is provided with a combustion chamber, the back of the piston seat is provided with a cooling liquid tank, the back of the piston seat is also integrally forged with a pair of symmetrically arranged supporting seats, the supporting seats are provided with through holes, the piston skirts press the oil duct baffles to the upper part of the cooling liquid tank, two side edges of the oil duct baffles are connected with the side edges of the supporting seats to form a piston guide seat, the oil duct baffles are provided with oil inlet holes, pin holes are formed in the edge positions of the oil duct baffles, and the piston seat is provided with seam riding pins matched with the pin holes. The steel piston has a simple structure, the acting force on the welding seam in the motion process of the piston is small, the guiding precision of the piston can be well controlled, the service life of the piston is prolonged, and the strength and the impact resistance of the piston are improved; the adopted production process is simple and reasonable, is convenient to produce and is suitable for large-scale production.

Description

Steel piston for diesel engine and production process thereof

Technical Field

The invention relates to a steel piston for a diesel engine and a production process thereof, belonging to the field of steel pistons.

Background

The high-pressure common rail, turbocharging and post-processing technology … … a series of international advanced key part technologies seem to show certain regularity in popularization and large development in China, and the key part piston of an engine is the same, so that most heavy diesel engines in North America use all-steel pistons, and the light diesel engine of the next generation of passenger cars in Europe is switched to all-steel pistons in large batch at present. Therefore, in view of the development trend, in future generations of european high-performance diesel engines, steel pistons are used as the "clean color" of the diesel engines, and in view of the fact that china will achieve the emission regulations of six countries around 2020, the demand of chinese heavy-duty diesel engines is smaller and smaller compared with that of foreign countries in spite of certain differences in reliability, target, emission and the like.

With the continuous improvement of the strengthening index of the heavy diesel engine, the heavy diesel engine is a trend to adopt advanced forged steel pistons, steel pistons are required in the market of the Chinese heavy diesel engine from the beginning of the fifth country, the Chinese steel pistons are expected to explosively increase in 2022, the demand amount reaches about 200 thousands, more and more domestic enterprises begin to research and develop the steel pistons in view of explosive growth of the steel pistons, the steel pistons are pistons adopting steel materials to replace aluminum materials and have good strength, but the processing performance is reduced, most of the steel pistons adopt an integral structure or a two-section structure at present, the processing process of the steel pistons of the integral structure is very difficult, particularly, the steel pistons are very complicated when piston cooling liquid tanks are processed, in addition, the common guide seats are limited by product structures and are not easy to manufacture, the steel pistons of the two-section structure adopt the piston seats and the guide seats to be processed independently, finally, the piston seats and the guide seats are spliced in a welding mode, the welding seams are located at the back of the piston seats, and the existing steel piston structures are directly influenced by the tensile force and the shearing force of the pistons and the pistons are easy to break.

Disclosure of Invention

In order to solve the defects of the prior art, the invention aims to provide a steel piston for a diesel engine and a production process thereof.

In order to achieve the above object, the present invention adopts the following technical solutions:

the utility model provides a steel piston for diesel engine, its characterized in that, including the piston seat, 2 the same semi-annular oil duct baffles and a pair of skirt of piston that sets up along piston seat axis symmetry, the combustion chamber has been seted up to the head of aforementioned piston seat, the cooling tank has been seted up at the back of piston seat, the supporting seat that aforementioned piston seat back still integrative forging has a pair of symmetry to set up and seted up the perforating hole on the supporting seat, be formed with the inlet port on the aforementioned oil duct baffle and the border position is formed with the pinhole, be provided with on the aforementioned piston seat with pinhole complex ride the seam round pin.

Preferably, the piston skirt tightly presses the oil duct baffle above the cooling liquid tank, and two side edges of the oil duct baffle are connected with the side edges of the supporting seat to form the piston guide seat, so that the connecting surface is subjected to small impact force in the motion of the piston, and the overall strength of the piston is high.

Preferably, the piston skirt is formed by two steel plates forged into an arc shape, so that the length of the piston skirt can be properly increased, the piston guiding precision is improved, and the overall strength of the piston is improved.

Preferably, the piston seat is turned with a step on the top of the cooling liquid tank, the oil passage baffle is mounted on the step, and the width of the oil passage baffle is the same as the width of the top surface of the cooling liquid tank.

Preferably, the piston skirt and the supporting seat are connected together through laser welding, so that the welding deformation pressure is reduced, and the overall accuracy of the piston is improved.

Preferably, the oil inlet hole is formed at a position close to the support seat.

Preferably, the seam riding pin is a cylindrical pin shaft, is completely immersed in the pin hole, is mainly used for fixing the oil duct baffle plate and preventing the oil duct baffle plate from deviating, and is simple in structure and convenient to implement.

Preferably, the outer circle of the piston seat is provided with 2-3 layers of sealing grooves which are mainly used for placing a piston ring, and the through hole is internally provided with a groove close to the outer wall of the supporting seat and mainly used for installing a limiting snap ring.

Preferably, the piston seat is integrally forged by forged steel, so that the piston has higher strength and impact resistance.

In order to better understand and implement the invention, the production process of the steel piston for the diesel engine is also disclosed, and comprises the following steps:

s1, forging a piston seat according to a specified size, then driving an excircle to process, then roughly machining a combustion chamber at the head of the piston seat and finely machining a cooling liquid tank on the back of the piston seat;

s2, installing an oil duct baffle on the cooling liquid tank on the back of the piston seat, drilling a pin hole in the oil duct baffle, and installing a seam riding pin matched with the pin hole;

s3, welding the piston skirt on two side edges of a supporting seat on the back of the piston seat through laser welding, cooling to normal temperature, processing a welding seam through a milling cutter, and then cutting on the oil duct baffle to form an oil inlet;

and S4, performing finish machining on the combustion chamber at the head of the piston seat and the piston skirt, and then machining the through hole in the supporting seat through boring.

The invention has the advantages that: the steel piston has the advantages of simple structure, convenience in implementation, long piston skirt guiding length, short connecting weld joint length, small acting force on the weld joint in the piston movement process, capability of well controlling the guiding precision of the piston, prolonging the service life of the piston, improving the strength and the impact resistance of the piston and good market prospect; the adopted production process is simple and reasonable, is convenient to produce and is suitable for large-scale production.

Drawings

FIG. 1 is a schematic illustration of the explosive structure of a preferred embodiment of a steel piston for a diesel engine of the present invention;

FIG. 2 is an assembled view of a steel piston for a diesel engine of the present invention;

FIG. 3 is a sectional view of an assembled view of a steel piston for a diesel engine of the present invention;

fig. 4 is a schematic sectional view taken along line B-B in fig. 2.

The meaning of the reference symbols in the figures: 1. the piston comprises a piston skirt, 2 an oil duct baffle, 3 an oil inlet hole, 4 a joint pin, 5 a supporting seat, 6 a cooling liquid tank, 7 a piston seat, 8 a sealing groove, 9 and a groove.

Detailed Description

The invention is described in detail below with reference to the figures and the embodiments.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on those shown in the drawings, and are used only for convenience in describing the present invention and for simplicity in description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

Referring to fig. 1 and 2, the steel piston for a diesel engine of the present invention includes a

piston seat

7, 2 identical semicircular oil duct baffles 2 and a pair of piston skirts 1 symmetrically disposed along an axis of the piston seat 7, where the piston skirt 1 is formed of two arc-shaped forged steel plates, a cooling liquid tank 6 is disposed on a back surface of the piston seat 7, a pair of symmetrically disposed supporting seats 5 is further integrally forged on the back surface of the piston seat 7, and a through hole is disposed on the supporting seat 5, the piston skirt 1 presses the oil duct baffles against the upper side of the cooling liquid tank 6, and both side edges of the oil duct baffles are connected with side edges of the supporting seats 5 by laser welding to form a piston guide seat, an oil inlet hole 3 is formed in a position on the oil duct baffles 2 close to the supporting seats 5, and a pin hole is formed in an edge position of the oil duct baffles, and a seam-riding pin 4 matched with the pin hole is disposed on the piston seat 7, specifically in the present embodiment, the seam-riding pin 4 is a cylindrical pin, and the seam-riding pin 4 is completely submerged in the pin hole.

Referring to fig. 3 and 4, the piston seat 7 is formed by integrally forging forged steel, a combustion chamber is formed in the head of the piston seat 7, a step is turned on the top of the cooling liquid tank 6 of the piston seat 7, the oil duct baffle 2 is installed on the step, the width of the oil duct baffle 2 is the same as the width of the top surface of the cooling liquid tank 6, 2-3 layers of sealing grooves 8 are formed in the outer circle of the piston seat 7, and a groove 9 is formed in the through hole close to the outer wall of the supporting seat 5.

The production of the steel piston for the diesel engine comprises the following steps:

s1, forging the piston seat 7 according to a specified size, then performing excircle processing, then roughly processing a combustion chamber at the head of the piston seat 7, and finely processing a cooling liquid tank 6 on the back of the piston seat 7;

s2, installing the oil duct baffle 2 on a cooling liquid groove 6 on the back of the piston seat 7, drilling a pin hole in the oil duct baffle 2, and installing a seam-riding pin 4 matched with the pin hole;

s3, welding the piston skirt 1 on two side edges of a supporting seat 5 on the back of the piston seat 7 through laser welding, cooling to normal temperature, processing a welding line through a milling cutter, and then cutting the oil duct baffle 2 to form an oil inlet hole 3;

and S4, performing finish machining on the combustion chamber at the head of the piston seat 7 and the piston skirt 1, and then machining the through hole in the supporting seat 5 through boring.

The working process of the steel piston for the diesel engine is briefly described as follows:

the steel piston is arranged in a diesel engine, the engine burns oil in a combustion chamber of a piston seat 7, a through hole on a supporting seat 5 is connected with a piston pin and does work circularly to realize energy conversion, cooling liquid is communicated in a cooling liquid tank 6, and the oil inlet hole 3 on an oil duct baffle 2 is used for backflow to cool the whole piston.

In conclusion, the steel piston has the advantages of simple structure, convenience in implementation, long piston skirt guiding length, short connecting weld joint length and small acting force on the weld joint in the piston movement process, can well control the guiding precision of the piston, prolong the service life of the piston, improve the strength and the impact resistance of the piston and has good market prospect; the adopted production process is simple and reasonable, is convenient to produce and is suitable for large-scale production.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The foregoing illustrates and describes the principles, general features, and advantages of the present invention. It should be understood by those skilled in the art that the above embodiments do not limit the present invention in any way, and all technical solutions obtained by using equivalent alternatives or equivalent variations fall within the scope of the present invention.

Claims

1. The utility model provides a steel piston for diesel engine, its characterized in that, includes piston seat (7), 2 the same semi-ring shape oil duct baffles (2) and a pair of skirt (1) that sets up along piston seat (7) axis symmetry, the combustion chamber has been seted up to the head of piston seat (7), and cooling cistern (6) have been seted up at the back of piston seat (7), piston seat (7) back still integrative forging have a pair of symmetrical supporting seat (5) that set up and seted up the perforating hole on supporting seat (5), skirt (1) with the oil duct baffle compress tightly in cooling cistern (6) top and both sides limit all be connected with supporting seat (5) side after constitute piston guide seat, be formed with inlet port (3) and edge position on oil duct baffle (2) and be formed with the pinhole, be provided with on piston seat (7) with pinhole complex seam round pin (4).

2. A steel piston for diesel engines according to claim 1, characterised in that the piston skirt (1) consists of two steel plates forged into an arc shape.

3. The steel piston for the diesel engine as claimed in claim 1, characterized in that the top of the cooling liquid tank (6) of the piston seat (7) is lathed with a step, the oil passage baffle (2) is mounted on the step, and the width of the oil passage baffle (2) is the same as the width of the top surface of the cooling liquid tank (6).

4. A steel piston for diesel engines, according to claim 1, characterized in that the piston skirt (1) and the support seat (5) are joined together by laser welding.

5. A steel piston for diesel engines, according to claim 1, characterized in that said oil inlet hole (3) opens close to the support seat (5).

6. A steel piston for diesel engines according to claim 1 characterized in that the overlocking pin (4) is a cylindrical pin, the overlocking pin (4) being completely immersed in the pin hole.

7. The steel piston for the diesel engine as claimed in claim 1, wherein 2-3 layers of sealing grooves (8) are formed in the outer circle of the piston seat (7), and a groove (9) is formed in the through hole and close to the outer wall of the supporting seat (5).

8. A steel piston for diesel engines, according to any of claims 1 to 7, characterized in that the piston seat (7) is integrally forged from forged steel.

9. The process for producing a steel piston for a diesel engine as set forth in claim 1, comprising the steps of:

s1, forging a piston seat (7) according to a specified size, then performing excircle processing, then roughly processing a combustion chamber at the head of the piston seat (7) and finely processing a cooling liquid tank (6) at the back of the piston seat (7);

s2, installing the oil duct baffle (2) on a cooling liquid tank (6) on the back of the piston seat (7), drilling a pin hole in the oil duct baffle (2), and installing a seam riding pin (4) matched with the pin hole;

s3, welding the piston skirt (1) on two side edges of a back support seat (5) of the piston seat (7) through laser welding, cooling to normal temperature, processing a weld joint through a milling cutter, and then cutting the oil duct baffle (2) to form an oil inlet hole (3);

and S4, performing finish machining on the combustion chamber at the head of the piston seat (7) and the piston skirt (1), and then machining the through hole in the supporting seat (5) through boring.