Engine piston

Abstract

The engine piston structurally comprises a piston head, a piston skirt, an oil cavity isolation plate and a piston pin hole. The piston head part is fixedly connected with the piston skirt part, an annular cooling oil cavity and a basin-shaped cooling oil cavity are formed in the piston head part, and the annular cooling oil cavity is isolated from the basin-shaped cooling oil cavity; the oil cavity isolation plate is detachably arranged between the piston head part and the piston skirt part and is used for sealing the annular cooling oil cavity to form a closed cavity; and a piston pin hole communicated with the basin-shaped cooling oil cavity is also formed in the piston skirt part. According to the piston structure, the piston head and the piston skirt are fixedly connected, the detachable oil cavity isolation plate is arranged between the piston head and the piston skirt, the surface connecting position of the annular cooling oil cavity can be conveniently machined, the machining difficulty is low, the manufacturing cost is reduced, the surface smoothness of the cooling oil cavity of the piston structure is high, and the service life of the piston structure is prolonged. The service structure reliability of the piston is enhanced; piston weight is reduced, and engine performance is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of pistons, and in particular relates to an engine piston and a manufacturing method thereof. Background Art

[0002] In modern internal combustion engine technology, the engine piston is a core component, and its performance directly affects the overall efficiency, durability and fuel economy of the engine. The manufacturing of traditional engine pistons often adopts the method of multi-weld splicing or integral casting. While these methods ensure structural strength, they also bring a series of problems, especially in the processing and surface treatment of the oil cavity.

[0003] First, although the process of multi-weld joint pistons is relatively mature, the large number of welds not only increases the manufacturing difficulty and cost, but may also cause the oil chamber surface to be uneven, affecting the lubrication effect and piston life. In addition, defects such as welding slag, weld nodules and flash generated during the welding process are difficult to completely remove by conventional means if they are located on the inside of the oil chamber, which in turn affects the fluidity and heat dissipation efficiency of the cooling oil. Secondly, although the integrally cast piston reduces the number of welds, defects such as pores and shrinkage during the casting process will also affect the strength of the piston and the surface quality of the oil chamber. At the same time, the casting process has a low material utilization rate, which is not conducive to lightweight design.

[0004] In response to the above problems, the industry has begun to explore new piston structure designs in order to seek higher manufacturing precision, better surface quality and lighter weight, which is a technical problem that needs to be solved urgently in the industry. Utility Model Content

[0005] In order to solve the above-mentioned existing technologies, this technical solution proposes an innovative engine piston, which aims to achieve a single weld connection of the piston and significantly improve the surface quality of the oil chamber by optimizing the structural design of the piston. Specifically, the application reserves sufficient operating space between the piston head blank and the piston skirt blank, and at the same time, by assembling between the head and the skirt, it not only simplifies the manufacturing process, but also further reduces the weight of the piston, which is in line with the development trend of lightweight modern internal combustion engines.

[0006] The utility model provides an engine piston, the specific technical scheme is as follows, including: a piston head, a piston skirt, an oil chamber isolation plate, and a piston pin hole;

[0007] The piston head is fixedly connected to the piston skirt, and an annular cooling oil cavity and a basin-shaped cooling oil cavity are formed on the piston head, and the annular cooling oil cavity is isolated from the basin-shaped cooling oil cavity;

[0008] The oil chamber isolation plate is detachably arranged between the piston head and the piston skirt to seal the annular cooling oil chamber to form a closed cavity;

[0009] The piston skirt is also provided with the piston pin hole communicating with the basin-shaped cooling oil cavity.

[0010] Preferably, the oil chamber isolation plate is a split structure, which is spliced ​​and surrounded between the piston head and the piston skirt.

[0011] Preferably, the specific number of the oil chamber isolation plates is two semicircular oil chamber isolation plates.

[0012] Preferably, an annular groove is provided on the piston skirt, the bottom of the oil chamber isolation plate is clamped in the annular groove, and the top of the oil chamber isolation plate abuts against the inside of the annular cooling oil chamber on the piston head.

[0013] Preferably, the piston pin hole is perpendicular to the central axis of the piston skirt and is arranged on the outer side surface of the piston skirt.

[0014] Preferably, the piston head and the piston skirt are welded by high-energy beam welding, and a horizontal weld is formed at the junction of the piston head and the piston skirt.

[0015] Preferably, a horizontal annular weld is formed on the contact surface between the piston head and the piston skirt.

[0016] Preferably, the annular groove of the piston skirt, the piston pin hole, and the horizontal annular weld joint formed on the contact surface of the piston head and the piston skirt are all made by precision machining.

[0017] Preferably, the piston head and the piston skirt are made of 42CrMo or 38MnVS.

[0018] Preferably, the oil chamber isolation plate is made of T8 or 65Mn.

[0019] The utility model provides an engine piston structure, which is fixedly connected at the piston head and the piston skirt and has a detachable oil chamber isolation plate therebetween, so that the surface connection of the annular cooling oil chamber can be conveniently processed, the processing difficulty is low, and the manufacturing cost is reduced. In addition, the cooling oil chamber surface of the piston structure provided by the application scheme has a high smoothness, which enhances the reliability of the piston service structure; reduces the weight of the piston and improves the engine performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 is an overall cross-sectional view of an engine piston in a specific embodiment;

[0022] Figure 2 This is a schematic diagram of the piston head blank;

[0023] Figure 3 This is a schematic diagram of the piston skirt blank;

[0024] Figure 4 This is a schematic diagram of the welding structure of the engine piston;

[0025] Figure 5 This is a schematic diagram of the rough machining structure of the engine piston;

[0026] Figure 6 This is a schematic diagram of the engine piston finishing structure.

[0027] The reference numerals are as follows:

[0028] 1. Piston head; 2. Piston skirt; 3. Oil chamber isolation plate; 4. Piston pin hole; 5. Annular cooling oil chamber; 6. Basin-shaped cooling oil chamber; 7. Annular groove; 8. Horizontal annular weld. DETAILED DESCRIPTION

[0029] In order to enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0030] It should be noted that when an element is referred to as being "fixed on" or "set on" another element, it can be directly on the other element or indirectly set on the other element; when an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0031] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0032] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, "multiple" and "several" mean two or more, unless otherwise clearly and specifically defined.

[0033] It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the conditions under which this application can be implemented. Therefore, they have no substantive technical significance. Any structural modification, change in proportional relationship or adjustment of size should still fall within the scope of the technical content disclosed in this application without affecting the effects and purposes that can be achieved by this application.

[0034] Please refer to Figures 1 to 6 , the technical solution of the utility model is specifically described as a structure of an engine piston, including: a piston head 1, a piston skirt 2, an oil chamber isolation plate 3, and a piston pin hole 4;

[0035] In the present application, the piston head 1 and the piston skirt 2 are of split design structure, specifically, in the present embodiment, they are of upper and lower split connection arrangement, and the two are fixedly connected, and the connection method is fixed by welding, threading or bolts or one or more combination methods; an annular cooling oil cavity 5 and a basin-shaped cooling oil cavity 6 are formed on the piston head 1, and the annular cooling oil cavity 5 and the basin-shaped cooling oil cavity 6 are isolated to prevent the cooling oil in the two from being directly exchanged, and an annular groove is also provided on the piston head 1 to further reduce the weight of the piston head 1;

[0036] As an important component of the annular cooling oil chamber 5, the oil chamber isolation plate 3 is detachably arranged between the piston head 1 and the piston skirt 2 in the present application, so as to seal the annular cooling oil chamber 5 to form a closed cavity. The detachable oil chamber isolation plate 3 design can facilitate processing of the connection after the piston head 1 and the piston skirt 2 are fixedly connected, thereby improving the surface quality of the connection.

[0037] The piston skirt 2 is also provided with the piston pin hole 4 which is in communication with the basin-shaped cooling oil cavity 6. The piston skirt 2 is a hollow structure and can be conveniently connected to the engine body by providing the piston pin hole 4.

[0038] Preferably, in the present application, the annular cooling oil chamber 5 is isolated from the basin-shaped cooling oil chamber 6. In order to lubricate the piston skirt 2 and the piston pin hole 4, the oil chamber isolation plate 3 is set as a split structure, which is spliced ​​and arranged between the piston head 1 and the piston skirt 2. The fitting clearance between the oil chamber isolation plates 3 can allow part of the engine oil to flow back to the piston skirt 2 for lubrication.

[0039] More preferably, in this embodiment, Figure 1 As shown, the specific number of the oil chamber isolation plates 3 is two semicircular oil chamber isolation plates 3, which are spliced ​​and surrounded between the piston head 1 and the piston skirt 2; in other embodiments, the specific number of the oil chamber isolation plates 3 can be adjusted according to actual usage requirements, but they should all be spliced ​​to tightly enclose the annular cooling oil chamber 5.

[0040] As a preferred example, Figure 1 As shown, in the present embodiment, the oil chamber isolation plate 3 is specifically formed by providing an annular groove 7 on the piston skirt 2, the bottom of the oil chamber isolation plate 3 is clamped in the annular groove 7, and the top of the oil chamber isolation plate 3 is abutted against the inside of the annular cooling oil chamber 5 on the piston head 1 to achieve a detachable connection, and the width of the annular groove 7 is set to match the thickness of the oil chamber isolation plate 3.

[0041] As a preferred example, Figure 1 As shown, in this embodiment, the piston pin hole 4 is perpendicular to the central axis of the piston skirt 2 and is arranged on the outer side of the piston skirt 2. The pin hole is arranged on the side and can provide power transmission for the up and down movement of the piston through the connecting rod structure.

[0042] Preferably, compared with the prior art, the connection between the piston head and the skirt has both a vertical connection seam and a horizontal connection seam; in the present application, since the piston head 1 and the piston skirt 2 are independently designed as upper and lower parts, a single horizontal weld is formed at the junction of the piston head 1 and the piston skirt 2 when connected by high-energy beam welding. By reducing the direction and type of welds, the connection stability of the piston is improved, and the overall strength of the piston is improved.

[0043] Furthermore, since the piston head 1 and the piston skirt 2 are split into upper and lower parts, in order to improve the stability of the connection, the present application scheme chooses to form a horizontal annular weld 8 by sleeved on the periphery of the contact surface in the horizontal direction to fix the piston head 1 and the piston skirt 2.

[0044] Preferably, in order to ensure the connection quality between the various components of the piston, the annular groove 7 and the piston pin hole 4 of the piston skirt 2 are made of fine processing in the present application, and can be processed in advance in the blank state; at the same time, because of the design of the detachable oil chamber isolation plate 3, a horizontal annular weld 8 connection can be formed on the contact surface of the piston head 1 and the piston skirt 2. When the oil chamber isolation plate 3 is not installed, a sealed cavity is not formed, so fine processing can be achieved at the same time to ensure the surface quality of the annular cooling oil chamber 5.

[0045] Preferably, in the present embodiment, the piston head 1 and the piston skirt 2 are made of 42CrMo or 38MnVS.

[0046] Furthermore, the oil chamber isolation plate 3 is made of T8 or 65Mn.

[0047] Combine the following Figures 1 to 6 , the manufacturing process of the engine piston provided by the present application scheme is described, and the specific process is as follows:

[0048] 1. Processing the piston head 1, specifically processing the annular cooling oil cavity 5 and the welding joint surface of the piston head 1 to form a welding blank of the piston head 1;

[0049] 2. Processing the skirt, specifically processing the annular cooling oil cavity 5, the welding joint surface of the piston skirt 2, and the annular groove 7 of the piston skirt 2 to form a welding blank of the piston skirt 2;

[0050] 3. The piston head 1 welding blank and the piston skirt 2 welding blank are positioned by means of a fixture and a welding joint surface, and a welding gun realizes single weld welding from the operating space formed after the piston head 1 and the piston skirt 2 are assembled;

[0051] 4. The welded whole is transferred to the machining process, and the inner cavity of the piston skirt 2 and the annular cooling oil cavity 5 are partially machined. The welding slag, weld nodules / flash, etc. generated in the inner cavity of the piston can be removed by machining, and the weld nodules / flash, etc. generated on the inner side of the piston cooling oil cavity can be removed by machining through the operating space;

[0052] 5. Finish the entire piston, including the annular groove 7, the outer surface of the piston, the piston pin hole 4, etc.;

[0053] 6. Two oil chamber isolation plates 3 are embedded and installed between the skirt annular groove 7 and the head to form the annular cooling oil chamber 5. The matching clearance between the two oil chamber isolation plates 3 can allow part of the engine oil to flow back to the piston skirt 2, which is beneficial to the lubrication of the piston skirt and the piston pin hole 4;

[0054] 7. Finally, the engine piston is prepared as a finished product.

[0055] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An engine piston, characterized in that: include: Piston head, piston skirt, oil chamber isolation plate, piston pin hole; The piston head is fixedly connected to the piston skirt, and an annular cooling oil cavity and a basin-shaped cooling oil cavity are formed on the piston head, and the annular cooling oil cavity is isolated from the basin-shaped cooling oil cavity; The oil chamber isolation plate is detachably arranged between the piston head and the piston skirt to seal the annular cooling oil chamber to form a closed cavity; The piston skirt is also provided with the piston pin hole communicating with the basin-shaped cooling oil cavity.

2. The engine piston according to claim 1, characterized in that: The oil chamber isolation plate is a split structure, which is spliced ​​and surrounded between the piston head and the piston skirt.

3. The engine piston according to claim 2, characterized in that: The specific number of the oil chamber isolation plates is two semicircular oil chamber isolation plates.

4. The engine piston according to claim 3, characterized in that: An annular groove is provided on the piston skirt, the bottom of the oil chamber isolation plate is clamped in the annular groove, and the top of the oil chamber isolation plate abuts against the inside of the annular cooling oil chamber on the piston head.

5. The engine piston according to claim 4, characterized in that: The piston pin hole is perpendicular to the central axis of the piston skirt and is arranged on the outer side of the piston skirt.

6. The engine piston according to claim 4, characterized in that: The piston head and the piston skirt are welded by high-energy beam welding, and a horizontal weld is formed at the junction of the piston head and the piston skirt.

7. The engine piston according to claim 6, characterized in that A horizontal annular weld is formed on the contact surface between the piston head and the piston skirt.

8. The engine piston according to claim 7, characterized in that: The annular groove of the piston skirt, the piston pin hole, and the horizontal annular weld joint formed on the contact surface of the piston head and the piston skirt are all made by precision machining.

9. The engine piston according to any one of claims 1 to 8, characterized in that: The piston head and the piston skirt are made of 42CrMo or 38MnVS.

10. The engine piston according to claim 9, characterized in that The oil chamber isolation plate is made of T8 or 65Mn.

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