Piston back cooling structure and engine

Abstract

The utility model discloses a piston back cooling structure which comprises an oil injection structure arranged on a crankcase body and used for injecting cooling oil to the back of a piston, and the oil injection structure is provided with an oil injection opening capable of injecting the cooling oil to the back of the piston. The direction of the oil spraying opening can enable the spraying target position of the cooling oil to cover the back of the piston in the radial direction in the up-down reciprocating motion process of the piston; the utility model further discloses an engine. According to the piston back cooling structure, the cooling performance of the piston can be effectively improved, so that the service life of an engine is prolonged, and the cost is reduced; specifically, the orientation of an oil spraying opening is optimally designed, and a cooling oil spraying target position covers the back of the piston in the radial direction of the piston in the vertical reciprocating motion process of the piston, so that the cooling area is effectively increased, the back of the piston can be well cooled, and the cooling performance of the piston is effectively improved.

Description

Technical Field

[0001] The utility model relates to the technical field of engine cooling structure design, in particular to a piston back cooling structure and an engine. Background Art

[0002] At present, with the continuous demand for engine power and torque improvement in the industry, in order to improve the thermal efficiency of the engine, the compression ratio is increased as much as possible to effectively improve the engine performance and improve emissions; but this can also easily lead to piston overheating, requiring the piston to have higher strength and durability, which will undoubtedly increase costs and also affect the life of the engine. Therefore, research on improving the cooling performance of the piston is very necessary. In the existing related technology, by arranging oil nozzles in the engine crankcase, the liquid inlet ends of these cooling nozzles are connected to the oil pump fixed to the outside or the engine case through cooling pipes, and then the oil nozzles are used to spray cooling oil to the back of the piston to take away a large amount of heat from the piston. However, most of the existing oil nozzles are installed in a relatively vertical manner to the back of the piston. With such a structure, the oil nozzle can only spray to a specific part of the piston, the spraying area is limited, and the cooling effect is limited.

[0003] Therefore, it is necessary to provide a new piston back cooling structure and engine, so as to improve the cooling performance of the piston, thereby increasing the service life of the engine and reducing the cost. Utility Model Content

[0004] In view of this, an object of the present invention is to provide a piston back cooling structure and an engine, which can effectively improve the cooling performance of the piston, thereby increasing the service life of the engine and reducing costs.

[0005] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a piston back cooling structure, including an oil spray structure arranged on a crankcase body for spraying cooling oil onto the back of the piston, the oil spray structure has an oil spray port that can spray cooling oil onto the back of the piston, and the direction of the oil spray port can make the spray target position of the cooling oil cover the back of the piston along the radial direction of the piston during the up and down reciprocating motion of the piston.

[0006] Furthermore, the oil injection port is located on a side of the crankcase body close to the intake side of the piston, and when the piston is at the top dead center position, the injection target position of the cooling oil is located on the back of the exhaust side of the piston.

[0007] Furthermore, the oil injection structure also includes an oil supply passage formed in the crankcase and connected to the engine lubricating oil passage, and the oil injection port is an oil injection hole provided in the crankcase and connected to the oil supply passage.

[0008] Furthermore, there are at least two oil injection holes arranged along the axial direction of the engine crankshaft.

[0009] Furthermore, there are two oil injection holes, and the two oil injection holes are respectively located on both sides of the piston connecting rod in the axial direction of the engine crankshaft.

[0010] Furthermore, the distance between the two oil injection holes in the axial direction of the engine crankshaft is smaller than the diameter of the piston.

[0011] Furthermore, the section of the oil supply passage adjacent to the oil injection hole is arranged parallel or approximately parallel to the axis of the engine crankshaft, and the direction of the oil injection hole is spatially perpendicular to the axial direction of the engine crankshaft.

[0012] Furthermore, a process groove arranged along the axial direction of the engine crankshaft is provided on the outer wall of the crankcase corresponding to the oil supply passage, and the oil injection hole is arranged in the process groove.

[0013] Furthermore, the diameter of the oil injection hole ranges from 0.8 to 1.5 mm.

[0014] An engine comprises the piston back-cooling structure as described above.

[0015] Compared with the prior art, the utility model has the following beneficial effects:

[0016] The piston back cooling structure provided by the utility model can effectively improve the cooling performance of the piston, thereby increasing the service life of the engine and reducing costs; specifically, the direction of the oil injection port is optimized, and since the cooling oil injection target position covers the piston back along the piston radial direction during the up and down reciprocating motion of the piston, the cooling area is effectively increased, the piston can be well cooled, and the cooling performance of the piston is effectively improved, thereby reducing the strength and durability requirements of the piston, which is beneficial to reducing costs. After the cooling performance is improved, the service life of the piston is increased, which is beneficial to increasing the service life of the engine; the engine provided by the utility model has good piston cooling effect and long service life.

[0017] Other advantages, objectives and features of the present invention will be described in the following description to some extent, and will be apparent to those skilled in the art based on the following examination and research, or can be taught from the practice of the present invention to some extent. The objectives and other advantages of the present invention can be achieved and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the cross-sectional structure of the utility model when the piston is at the top dead center position.

[0019] Figure 2 for Figure 1 A partial enlarged schematic diagram of point A in the middle

[0020] Figure numerals: 1-crankcase; 101-oil supply channel; 101a-injection hole; 102-process groove; 2-piston; 201-intake side; 202-exhaust side; 3-injection port; 4-engine crankshaft; 5-piston connecting rod. DETAILED DESCRIPTION

[0021] The following describes the implementation of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific implementations, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only used to illustrate the basic concept of the present invention, and the following embodiments and the features in the embodiments can be combined with each other without conflict.

[0022] See also Figure 1-2 The present embodiment discloses a piston back cooling structure, including an oil spraying structure arranged on a crankcase 1 for spraying cooling oil to the back of a piston 2, the oil spraying structure having an oil spraying port 3 for spraying cooling oil to the back of the piston 2, the direction of the oil spraying port 3 being such that the spraying target position of the cooling oil covers the back of the piston 2 along the radial direction of the piston 2 during the up and down reciprocating motion of the piston; the spraying target position of the cooling oil here refers to the contact point where the cooling oil is sprayed to the back of the piston 2, that is, the contact point between the oil spraying port 3 and the piston 2 along the extending ray of its own nozzle direction; it can be understood that the "back" of the piston 2 refers to the back of the side away from the engine combustion chamber, that is, the back side relative to the top of the piston 2, through the spraying The cooling oil takes away part of the heat of the piston 2, thereby cooling the piston 2. It can be understood that when the direction of the oil injection port 3 is not parallel to the axis of the piston 2, that is, when the two are arranged at an angle, the cooling oil injection target position can be moved to the back of the piston 2 during the up and down reciprocating motion of the piston. Here, "radially covering the back of the piston 2" means that when the cooling oil injection target position moves from one side edge of the piston 2 to the other side edge during the movement of the piston 2 from the top dead center position to the bottom dead center position, the cooling oil injection target position moves radially from one side edge of the piston 2 to the other side edge to achieve radial coverage of the back of the piston 2. Of course, the radial direction of the piston 2 here has multiple directions, which are not limited here, and preferably the direction from the exhaust side of the piston to the intake side;

[0023] The piston back cooling structure provided in the above structure can effectively improve the cooling performance of the piston 2, thereby increasing the service life of the engine and reducing costs; specifically, the direction of the oil injection port 3 is optimized. Since the cooling oil injection target position radially covers the back of the piston during the up and down reciprocating motion of the piston 2, the cooling area is effectively increased, the piston 2 can be well cooled, and the cooling performance of the piston is effectively improved, thereby reducing the strength and durability requirements of the piston 2, which is beneficial to reducing costs. After the cooling performance is improved, the service life of the piston 2 is increased, which is beneficial to increasing the service life of the engine.

[0024] In the present embodiment, the oil injection port 3 is located on a side of the crankcase 1 close to the intake side 201 of the piston 2, and the target injection position of the cooling oil is located on the back of the exhaust side 202 of the piston 2 when the piston 2 is at the top dead center position; specifically, the direction of the oil injection port 3 is arranged at a certain angle to the axis of the piston 2. It can be understood that in the engine piston structure, the intake side 201 and the exhaust side 202 of the piston 2 are respectively located at the two ends of the piston 2 in the radial direction. In order to achieve full coverage of the piston in the radial direction, the target injection position of the cooling oil is located at the back of the exhaust side 202 of the piston 2 near the edge when the piston 2 is at the top dead center position. Of course, it can be imagined that when the piston 2 is at the bottom dead center position, the cooling oil is injected into the exhaust side 202 of the piston 2. point position, the cooling oil injection target position will move to the edge of the back of the intake side 201 of the piston 2; this structural arrangement design can realize the back and forth movement of the cooling oil injection target position between the intake side 201 and the exhaust side 202 of the piston 2 during the up and down movement of the piston 2, which can match the operation process of the engine and better adapt to the engine piston movement. When the piston 2 is at the top dead center, the temperature of the exhaust side 202 of the piston 2 is higher. At this time, the cooling oil is just injected to the exhaust side 202 of the piston 2, which can better and timely take away the heat of the piston; similarly, the same principle applies when the piston is at the bottom dead center position; it is beneficial to further improve the cooling effect on the piston 2.

[0025] In this embodiment, the oil injection structure also includes an oil supply passage 101 formed on the crankcase 1 and connected to the engine lubricating oil passage, and the oil injection port 3 is an oil injection hole 101a arranged on the crankcase 1 and connected to the oil supply passage 101; the flow path of the oil supply passage 101 is not limited here, and it can usually be integrated in the crankcase 1 shell by casting. The engine lubricating oil passage here is an existing structure, and the lubricating oil is usually delivered by an oil pump arranged in the crankcase 1; in this structural design, the engine lubricating oil is directly used as the cooling oil, and the cooling oil has a certain pressure and can be sprayed, and the structure is simple; at the same time, the oil injection hole 101a arranged on the crankcase 1 is directly used as the oil injection port 3, and there is no need to install other structures such as oil spray nozzles, which also simplifies the structure and helps reduce costs; the oil injection hole 101a is easy to process and does not occupy additional layout space.

[0026] In this embodiment, there are at least two oil injection holes 101a arranged along the axial direction of the engine crankshaft 4; specifically, two are preferred here, and of course more can be designed when there is enough space for arrangement; by providing at least two oil injection holes 101a arranged along the axial direction of the engine crankshaft 4, the cooling area of ​​the back of the piston 2 can be further increased, thereby further improving the cooling effect on the piston 2; at the same time, the arrangement is reasonable, and can be better adapted to the arrangement of the piston 2, which is conducive to manufacturing.

[0027] In this embodiment, there are two oil injection holes 101a, and the two oil injection holes 101a are respectively located on both sides of the piston connecting rod 5 in the axial direction of the engine crankshaft 4; designing there are two is conducive to reducing production costs. At the same time, since the two oil injection holes 101a are respectively located on both sides of the piston connecting rod 5 in the axial direction of the engine crankshaft 4, most of the area of ​​the piston 2 in the axial direction of the engine crankshaft 4 can be effectively covered. The layout is reasonable and the piston connecting rod 5 can be prevented from blocking the oil.

[0028] In this embodiment, the distance between the two oil injection holes 101a in the axial direction of the engine crankshaft 4 is smaller than the diameter of the piston; this structural design is conducive to layout and can easily ensure that the cooling oil injected from the two oil injection holes 101a can be injected onto the piston 2, which helps to reduce design difficulty and development costs.

[0029] In this embodiment, the section of the oil supply channel 101 adjacent to the injection hole 101a is arranged parallel or approximately parallel to the axis of the engine crankshaft 4, and the direction of the injection hole 101a is arranged vertically in space with the axial direction of the engine crankshaft 4; this structural design has a simple structure, a reasonable layout, and is easy to process, and the injection port 3 can be machined, etc.

[0030] In this embodiment, a process groove 102 arranged along the axial direction of the engine crankshaft 4 is provided on the outer wall of the crankcase 1 corresponding to the oil supply passage 101, and the oil injection hole 101a is provided in the process groove 102; by providing the process groove 102, the process groove 102 and the crankcase 1 are integrally cast, which is beneficial to the later processing of the oil injection hole 101a and reduces the production cost.

[0031] In this embodiment, the diameter of the oil injection hole 101a ranges from 0.8 to 1.5 mm. Within this diameter range, the cooling oil injection effect is good and the cooling effect on the piston is good.

[0032] This embodiment also discloses an engine, including the piston back-cooling structure as described above; it is understandable that the engine usually has multiple cylinders, and the corresponding cylinders can adopt a similar piston back-cooling structure to complete the cooling of the piston; at the same time, it is conceivable that the oil supply channels 101 of each cylinder can be interconnected to reduce the design of the oil channels; the engine piston has good cooling effect and long service life.

[0033] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model rather than to limit it. Although the utility model has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the technical solution of the utility model can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the utility model, which should be included in the scope of the claims of the utility model.

Claims

1. A piston back cooling structure, characterized in that: The invention comprises an oil spraying structure arranged on a crankcase (1) for spraying cooling oil onto the back of a piston (2), the oil spraying structure having an oil spraying port (3) for spraying cooling oil onto the back of the piston (2), the oil spraying port (3) being oriented so that the spraying target position of the cooling oil covers the back of the piston along the radial direction of the piston during the up and down reciprocating motion of the piston.

2. The piston back cooling structure according to claim 1, characterized in that: The oil injection port (3) is located on a side of the crankcase (1) close to the intake side (201) of the piston (2), and when the piston (2) is at the top dead center position, the injection target position of the cooling oil is located on the back of the exhaust side (202) of the piston (2).

3. The piston back cooling structure according to claim 1, characterized in that: The oil injection structure also includes an oil supply passage (101) formed on the crankcase (1) and connected to the engine lubricating oil passage, and the oil injection port (3) is an oil injection hole (101a) provided on the crankcase (1) and connected to the oil supply passage (101).

4. The piston back cooling structure according to claim 3 is characterized in that: The number of the oil injection holes (101a) is at least two and is arranged along the axial direction of the engine crankshaft (4).

5. The piston back cooling structure according to claim 4, characterized in that: There are two oil injection holes (101a), and the two oil injection holes (101a) are respectively and correspondingly located on two sides of the piston connecting rod (5) in the axial direction of the engine crankshaft (4).

6. The piston back cooling structure according to claim 5, characterized in that: The distance between the two oil injection holes (101a) in the axial direction of the engine crankshaft (4) is smaller than the diameter of the piston.

7. The piston back cooling structure according to claim 4, characterized in that: The section of the oil supply passage (101) adjacent to the oil injection hole (101a) is arranged parallel or approximately parallel to the axis of the engine crankshaft (4), and the direction of the oil injection hole (101a) is arranged in a spatially perpendicular manner to the axial direction of the engine crankshaft (4).

8. The piston back cooling structure according to claim 4, characterized in that: A process groove (102) arranged along the axial direction of the engine crankshaft (4) is provided on the outer wall of the crankcase (1) corresponding to the oil supply passage (101), and the oil injection hole (101a) is provided in the process groove (102).

9. The piston back cooling structure according to claim 3, characterized in that: The diameter of the oil injection hole (101a) ranges from 0.8 to 1.5 mm.

10. An engine comprising the piston back cooling structure according to any one of claims 1 to 9.

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