Piston cooling structure and engine

Abstract

The utility model relates to a piston cooling structure and an engine, the piston cooling structure is used for cooling the inside of the engine, a cooling system comprises a piston, a connecting rod body, a crankshaft and a cylinder body, and one end of the connecting rod body extends into an inner cavity of the piston; the crankshaft is rotatably connected with the other end of the connecting rod body, and a first arc-shaped oil groove is formed in the connecting position of the crankshaft and the connecting rod body; the crankshaft is rotatably connected with the cylinder body, and a second arc-shaped oil groove is formed in the connecting position of the crankshaft and the cylinder body; cooling oil ways capable of being connected and disconnected are sequentially formed among the cylinder body, the crankshaft and the connecting rod body, and cooling liquid is guided into an inner cavity of the piston through the connecting rod body for cooling; the first arc-shaped oil groove or the second arc-shaped oil groove is a limiting oil groove, and the movement area where the crankshaft is located corresponds to the arc-shaped area of the limiting oil groove when the engine is ignited and combustion of the engine is finished. By the adoption of the scheme, the piston is not cooled at the low temperature, so that consumption of cooling liquid is effectively reduced, it can be guaranteed that the piston is continuously cooled when the piston is in the high-temperature state, and the pertinence of piston cooling is improved.

Description

Technical Field

[0001] This utility model relates to the technical field of piston cooling, and in particular to a piston cooling structure and engine. Background Technology

[0002] With the development of engine technology, engine power has continuously increased, as has the heat load, leading to a rise in piston crown temperature. To prevent structural failure due to excessive piston temperature, piston cooling nozzles are typically installed in engines with high heat loads. During engine operation, these nozzles spray engine oil into the piston crown to reduce its temperature.

[0003] When the piston is under maximum thermal load, it is near top dead center, and the distance between the piston and the piston cooling nozzle is relatively far. Due to gravity, the jet from the piston cooling nozzle is dispersed and the jet velocity is low, resulting in low cooling efficiency. To achieve effective piston cooling, the fuel injection quantity must be increased, increasing the energy consumption of the oil pump and the engine. Typically, the piston cooling nozzle is directly connected to the main oil passage in the cylinder block, and injection is controlled by a pressure valve or solenoid valve, increasing the structural and control complexity of the system, and also increasing the overall engine cost. Utility Model Content

[0004] Based on this, a piston cooling structure and engine are provided to improve the problem of low cooling efficiency and high cooling oil consumption caused by the need to increase the amount of oil injected when cooling the piston in the prior art.

[0005] On the one hand, this utility model provides a piston cooling structure for cooling the interior of an engine, the cooling system including:

[0006] piston,

[0007] Connecting rod body, one end of which extends into the piston cavity;

[0008] The crankshaft and the connecting rod body are rotatably connected at their other ends, and a first arc-shaped oil groove is provided at the connection position between them.

[0009] The cylinder block and crankshaft are rotatably connected, and a second arc-shaped oil groove is provided at the connection position between the two.

[0010] A switchable cooling oil passage is formed sequentially between the cylinder block, crankshaft, and connecting rod body, and the connecting rod body guides the coolant into the piston cavity for cooling; the first arc-shaped oil groove or the second arc-shaped oil groove is a limiting oil groove in which only a section of arc-shaped area in the circumferential direction can be connected to the coolant, and the movement area of ​​the crankshaft from engine ignition to the end of engine combustion corresponds to the arc-shaped area of ​​the limiting oil groove.

[0011] Based on the above technical solution, the present invention can be further improved as follows.

[0012] In one implementation, the two ends of the connecting rod body along its length are a large end and a small end, and each of the large end and the small end is provided with a corresponding connecting hole;

[0013] The cooling system also includes:

[0014] Connecting rod top tile,

[0015] The connecting rod lower bearing, connecting rod upper bearing, and connecting rod lower bearing form a ring-shaped connecting rod bearing. The connecting rod bearing is fixedly connected to the large end of the connecting rod body. The connecting rod bearing is sleeved on the outside of the crankshaft. The first arc-shaped oil groove is located on the connecting rod bearing and serves as a limiting oil groove.

[0016] In one implementation, the first arc-shaped oil groove is formed on the upper bearing of the connecting rod, and the first arc-shaped oil groove is symmetrically formed along the length direction of the connecting rod body.

[0017] In one implementation, the linkage body includes:

[0018] The first oil passage is opened along the length of the connecting rod body and connects the two ends of the connecting rod body along the length of the connecting rod body.

[0019] The first oil guide hole is located at the small end of the connecting rod body and is radially open.

[0020] The cooling system also includes:

[0021] Connecting rod bushing, which is fixedly connected to the small end of the connecting rod body;

[0022] The connecting rod bushing has the following openings:

[0023] The third arc-shaped oil groove is connected to the first oil passage;

[0024] The second oil guide hole is opened radially and is connected to the first oil guide hole.

[0025] In one implementation, there are at least three second oil guide holes, one of which is connected to the first oil passage, and the remaining second oil guide holes are evenly distributed circumferentially; the third arc-shaped oil groove is an arc-shaped segment oil groove, both ends of the arc-shaped end of the third arc-shaped oil groove are connected to the second oil guide holes, and the middle part of the third arc-shaped oil groove is connected to the first oil passage through the second oil guide holes, and the first oil passage is opened along the direction of the axis of symmetry of the connecting rod body.

[0026] In one implementation, the crankshaft has the following openings:

[0027] The third oil passage is located at the end where the crankshaft connects to the cylinder block, and the third oil passage is connected to the oil passage in the cylinder block.

[0028] The fourth oil passage is located at the end where the crankshaft connects to the connecting rod body, and is connected to the oil passage of the connecting rod body.

[0029] The fifth oil passage connects to the third and fourth oil passages at its two ends, respectively.

[0030] In one implementation, the third, fourth, and fifth oil passages are all linearly extending oil passages; the third and fourth oil passages are both opened along the radial direction of the crankshaft, while the fifth oil passage is opened at an angle and forms an acute angle with the radial section of the crankshaft.

[0031] In one implementation, the cooling system also includes:

[0032] Main shaft upper shell,

[0033] The main shaft bearing, which is formed by the lower main shaft bearing, upper main shaft bearing, and lower main shaft bearing, is fixed on the cylinder block. The second arc-shaped oil groove is located on the main shaft bearing and is a complete annular oil groove.

[0034] In one implementation, the cylinder block has the following openings:

[0035] The sixth oil passage is used to connect to the main oil cylinder;

[0036] The seventh oil passage is connected to the sixth oil passage and the crankshaft at its two ends, respectively. Coolant is introduced into the crankshaft sequentially along the sixth and seventh oil passages.

[0037] On the other hand, this utility model also provides an engine, including a piston cooling structure, and further comprising:

[0038] The main hydraulic cylinder is connected to the cylinder body.

[0039] An electronic oil pump is used to regulate the oil pressure in the master cylinder.

[0040] The beneficial effects of this utility model are as follows: By directly extending one end of the connecting rod body into the piston cavity, compared with the prior art of long-distance jet cooling of the piston, this solution directly introduces the coolant into the piston cavity for cooling, thereby effectively improving the cooling efficiency of the piston and reducing the pressure requirements of the coolant, thus effectively reducing the energy consumption for piston cooling; in addition, since a structure that can control the opening and closing of the cooling oil passage is set between the cylinder block, crankshaft, and connecting rod body, the continuous spraying of coolant is avoided, effectively reducing the energy consumption for piston cooling; since the cylinder block and crankshaft, and crankshaft and connecting rod body form a pair of corresponding rotatably connected structures, at least one of the corresponding second arc-shaped oil groove and first arc-shaped oil groove is an annular oil groove structure, which can limit the opening and closing of the cooling oil passage. Placed on the second or first arc-shaped oil groove, since the crankshaft's movement angle is fixed from engine ignition to the end of engine combustion, and the piston temperature is high and requires cooling during this movement, the arc-shaped area of ​​the limiting oil groove corresponds to the crankshaft's movement angle from engine ignition to the end of engine combustion. This ensures that the crankshaft can be cooled from engine ignition to the end of engine combustion. When the engine is not in the aforementioned state, the corresponding piston temperature is low, and the crankshaft's movement angle exceeds the range corresponding to the limiting oil groove. This causes the cooling oil path to be cut off at the limiting oil groove, preventing the piston from being cooled. In other words, the piston is not cooled at low temperatures, effectively reducing coolant consumption and ensuring continuous cooling of the piston at high temperatures, thus improving the targeted nature of piston cooling. Attached Figure Description

[0041] Figure 1 This is a schematic diagram of the piston cooling structure in one embodiment;

[0042] Figure 2 for Figure 1 Side view;

[0043] Figure 3 for Figure 1 A schematic diagram of the back structure;

[0044] Figure 4 This is a schematic diagram showing the piston cooling oil circuit when it is open;

[0045] Figure 5 This is a schematic diagram showing the piston cooling oil circuit when it is closed.

[0046] In the attached diagram, the components represented by each number are as follows:

[0047] 10. Piston;

[0048] 20. Connecting rod; 21. First oil passage; 22. First oil guide hole;

[0049] 30. Crankshaft; 31. Third oil passage; 32. Fourth oil passage; 33. Fifth oil passage;

[0050] 40. Cylinder block; 41. Sixth oil passage; 42. Seventh oil passage;

[0051] 51. First arc-shaped oil groove; 52. Second arc-shaped oil groove;

[0052] 60. Connecting rod bearing; 61. Upper connecting rod bearing; 62. Lower connecting rod bearing;

[0053] 70. Connecting rod bushing; 71. Third arc-shaped oil groove; 72. Second oil guide hole;

[0054] 80. Main shaft bearing; 81. Upper main shaft bearing; 82. Lower main shaft bearing; 83. Third oil guide hole. Detailed Implementation

[0055] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit the scope of this application. It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of this utility model. Therefore, the drawings only show components related to this utility model and are not drawn according to the actual number, shape, and size of the components. In actual implementation, the shape, quantity, and proportion of each component can be arbitrarily changed, and the component layout may also be more complex.

[0056] A piston 10 cooling structure, see Figures 1 to 3 The cooling system is used to cool the interior of the engine. It includes a piston 10, a connecting rod body 20, a crankshaft 30, and a cylinder block 40. One end of the connecting rod body 20 extends into the inner cavity of the piston 10. The crankshaft 30 and the connecting rod body 20 are rotatably connected, and a first arc-shaped oil groove 51 is provided at the connection position. The crankshaft 30 and the cylinder block 40 are rotatably connected, and a second arc-shaped oil groove 52 is provided at the connection position. A switchable cooling oil passage is formed between the cylinder block 40, the crankshaft 30, and the connecting rod body 20, and the connecting rod body 20 introduces coolant into the inner cavity of the piston 10 for cooling. The first arc-shaped oil groove 51 or the second arc-shaped oil groove 52 is a limiting oil groove in which coolant can flow through only a section of arc-shaped area in the circumferential direction. The movement area of ​​the crankshaft 30 from engine ignition to the end of engine combustion corresponds to the arc-shaped area of ​​the limiting oil groove.

[0057] This solution, by directly inserting one end of the connecting rod body 20 into the inner cavity of the piston 10, compared to the prior art of long-distance jet cooling of the piston 10, directly introduces the coolant into the inner cavity of the piston 10 for cooling, thereby effectively improving the cooling efficiency of the piston 10 and reducing the pressure requirements of the coolant, thus effectively reducing the energy consumption for cooling the piston 10. Furthermore, because a structure for controlling the opening and closing of the cooling oil passage is provided between the cylinder block 40, crankshaft 30, and connecting rod body 20, continuous coolant injection is avoided, effectively reducing the energy consumption for cooling the piston 10. Since the cylinder block 40 and crankshaft 30, and crankshaft 30 and connecting rod body 20 form a pairwise rotatably connected structure, at least one of the corresponding second arc-shaped oil groove 52 and first arc-shaped oil groove 51 is an annular oil groove structure, thus allowing the cooling oil passage opening and closing restriction structure to be designed... The crankshaft 30 is positioned on the second arc-shaped oil groove 52 or the first arc-shaped oil groove 51. Since the movement angle of the crankshaft 30 is fixed from engine ignition to the end of engine combustion, the piston 10 has a high temperature and needs to be cooled during this movement. Therefore, the arc-shaped area of ​​the limiting oil groove corresponds to the movement angle of the crankshaft 30 from engine ignition to the end of engine combustion. This allows the crankshaft 30 to be cooled from engine ignition to the end of engine combustion. When the engine is not in the aforementioned state, the temperature of the piston 10 is low, and the movement angle of the crankshaft 30 exceeds the range corresponding to the limiting oil groove. This causes the cooling oil path to be cut off at the limiting oil groove and does not cool the piston 10. That is, the piston 10 is not cooled at low temperatures, thereby effectively reducing the consumption of coolant and ensuring continuous cooling of the piston 10 at high temperatures, thus improving the targeted cooling of the piston 10.

[0058] In some embodiments of this application, see Figures 1 to 3 The connecting rod body 20 has a large end and a small end at its two ends along its length, and each end has a corresponding connecting hole. Thus, the connecting rod body 20 is divided into two ends, which are connected to different positions through the corresponding connecting holes in the large and small ends.

[0059] The cooling system also includes an upper connecting rod bearing 61 and a lower connecting rod bearing 62, which together form an annular connecting rod bearing 60. The connecting rod bearing 60 is fixedly connected to the large end of the connecting rod body 20 and is sleeved on the crankshaft 30. A first arc-shaped oil groove 51 is located on the connecting rod bearing 60, serving as a limiting oil groove. Thus, by using the first arc-shaped oil groove 51 as a limiting oil groove, the opening and closing of the cooling oil passage is restricted. The fixed connection between the connecting rod bearing 60 and the connecting rod body 20 causes relative rotation between the connecting rod bearing 60 and the crankshaft 30 during movement, thereby changing the relative angle between the connecting rod bearing 60 and the crankshaft 30, and correspondingly controlling the opening and closing of the cooling oil passage.

[0060] In some embodiments of this application, see Figures 1 to 3 The first arc-shaped oil groove 51 is formed on the upper bearing 61 of the connecting rod, and the first arc-shaped oil groove 51 is symmetrically formed along the length direction of the connecting rod body 20. In this way, by forming the first arc-shaped oil groove 51 completely on the upper bearing 61 of the connecting rod, the problem of complex connection structure caused by simultaneously forming the first arc-shaped oil groove 51 with only one arc-shaped area on the upper bearing 61 and the lower bearing 62 of the connecting rod is reduced, and the structure is effectively simplified.

[0061] In some embodiments of this application, see Figures 1 to 3 The connecting rod body 20 includes a first oil passage 21 and a first oil guide hole 22. The first oil passage 21 is opened along the length direction of the connecting rod body 20 and connects the two ends of the connecting rod body 20 along the length direction. The first oil guide hole 22 is opened at the small end of the connecting rod body 20 and is opened radially. In this way, by setting the first oil passage 21, the coolant can flow and be transmitted along the length direction of the connecting rod body 20, and by setting the first oil guide hole 22, the coolant can be discharged radially along the small end of the connecting rod body 20.

[0062] In some embodiments, see Figures 1 to 3 The small end of the connecting rod body 20 is rotatably connected to the piston 10 via a pin. When coolant is introduced into the first oil guide hole 22 to cool the piston 10, part of the coolant cools the inner cavity of the piston 10 radially outward, and part of the coolant cools the piston 10 radially inward from the second oil guide hole 72.

[0063] The cooling system also includes a connecting rod bushing 70, which is fixedly connected to the small end of the connecting rod body 20. The connecting rod bushing 70 has a third arc-shaped oil groove 71 and a second oil guide hole 72. The third arc-shaped oil groove 71 is connected to the first oil passage 21. The second oil guide hole 72 is radially arranged and connected to the first oil guide hole 22. Thus, by connecting the first oil passage 21 with the third arc-shaped oil groove 71 and connecting the second oil guide hole 72 with the first oil guide hole 22, coolant is introduced from the connecting rod body 20 into the small end of the connecting rod body 20. Subsequently, the coolant is introduced into the connecting rod bushing 70, and then sequentially discharged from the radially arranged second oil guide hole 72 and first oil guide hole 22, thereby spraying the coolant into the inner cavity of the piston 10 to achieve a cooling effect on the piston 10.

[0064] In some embodiments, see Figures 1 to 3 The connecting rod bushing 70 is a part installed in the small end hole of the connecting rod body 20. Its main function is to reduce the friction between the small end hole of the connecting rod body 20 and the piston pin 10, and to protect the small end hole of the connecting rod body 20 from wear.

[0065] In some embodiments of this application, there are at least three second oil guide holes 72, one of which is connected to the first oil passage 21, and the remaining second oil guide holes 72 are evenly distributed circumferentially; the third arc-shaped oil groove 71 is an arc-shaped segment oil groove, with both ends of the arc-shaped end of the third arc-shaped oil groove 71 connected to the second oil guide holes 72, and the middle part of the third arc-shaped oil groove 71 connected to the first oil passage 21 through the second oil guide holes 72, and the first oil passage 21 is opened along the direction of the axis of symmetry of the connecting rod body 20. In this way, the circumferentially evenly distributed second oil guide holes 72 facilitate uniform cooling of the piston 10, and the use of the arc-shaped segment of the third arc-shaped oil groove 71 reduces the amount of oil stored in the third arc-shaped oil groove 71.

[0066] In some embodiments, see Figures 1 to 3 The second oil guide holes 72 for oil injection are symmetrically arranged, so that the coolant can be evenly sprayed from the small end of the connecting rod body 20, and the inner cavity of the piston 10 can be evenly cooled. The specific number of the second oil guide holes 72 is adjusted based on the oil injection volume and the hole diameter, and the second oil guide holes 72 for oil injection are not limited to two. The third arc-shaped oil groove 71 can also be an annular oil groove.

[0067] In one specific embodiment, see Figures 1 to 3 There are three second oil guide holes 72. The second oil guide holes 72 used for oil injection are symmetrically arranged along the axis of symmetry of the connecting rod body 20. The only two second oil guide holes 72 are connected to the end of the arc-shaped section of the third arc-shaped oil groove 71, thereby reducing the dispersion of coolant, facilitating the direct discharge of coolant and reducing the diversion of coolant, and improving the instantaneous oil pressure of coolant. The other second oil guide hole 72 is located in the middle of the connecting rod bushing 70 and is used to connect to the first oil passage 21.

[0068] In some embodiments of this application, see Figures 1 to 3 The crankshaft 30 is provided with a third oil passage 31, a fourth oil passage 32, and a fifth oil passage 33. The third oil passage 31 is located at the end of the crankshaft 30 connected to the cylinder block 40 and is connected to the oil passage of the cylinder block 40. The fourth oil passage 32 is located at the end of the crankshaft 30 connected to the connecting rod body 20 and is connected to the oil passage of the connecting rod body 20. The two ends of the fifth oil passage 33 are connected to the third oil passage 31 and the fourth oil passage 32, respectively. In this way, by providing the third oil passage 31 on the crankshaft 30, the cooling oil passages of the cylinder block 40 and the crankshaft 30 are connected; by providing the fifth oil passage 33, the cooling oil passages at both ends of the crankshaft 30 are connected; and by providing the fourth oil passage 32, the cooling oil passages of the crankshaft 30 and the connecting rod body 20 are connected, thereby ensuring the cooling oil passages are connected along the direction from the cylinder block 40 and the crankshaft 30 to the connecting rod body 20.

[0069] In some embodiments, the crankshaft 30 includes a crankshaft 30 main journal and a crankshaft 30 connecting rod body 20 journal, the crankshaft 30 main journal being used to connect to the cylinder block 40, and the crankshaft 30 connecting rod body 20 journal being used to connect to the connecting rod body 20.

[0070] In some embodiments of this application, see Figures 1 to 3 The third oil passage 31, the fourth oil passage 32, and the fifth oil passage 33 are all linearly extending oil passages; the third oil passage 31 and the fourth oil passage 32 are both opened radially along the crankshaft 30, while the fifth oil passage 33 is opened at an angle and forms an acute angle with the radial section of the crankshaft 30. In this way, the linear oil passages reduce the length of the oil passages and reduce the amount of oil stored in the oil passages.

[0071] In the embodiment, both ends of the fifth oil passage 33 are located near the center of the crankshaft 30, and the third oil passage 31 and the fourth oil passage 32 are both opened radially along the crankshaft 30.

[0072] In some embodiments of this application, see Figures 1 to 3 The cooling system also includes an upper spindle bearing 81 and a lower spindle bearing 82, which together form an annular spindle bearing 80. The spindle bearing 80 is fixed to the cylinder block 40. A second arc-shaped oil groove 52 is located on the spindle bearing 80, and the second arc-shaped oil groove 52 is a complete annular oil groove. Thus, since the limiting oil groove is the first arc-shaped oil groove 51, setting the second arc-shaped oil groove 52 as a complete annular oil groove ensures that the coolant remains unobstructed in the second arc-shaped oil groove 52, with the oil flow restricted only by the first arc-shaped oil groove 51.

[0073] In some embodiments of this application, see Figures 1 to 3 The cylinder block 40 has a sixth oil passage 41 and a seventh oil passage 42. The sixth oil passage 41 is connected to the main oil cylinder. The two ends of the seventh oil passage 42 are connected to the sixth oil passage 41 and the crankshaft 30, respectively. Coolant is sequentially introduced into the crankshaft 30 along the sixth oil passage 41 and the seventh oil passage 42. In this way, the cylinder block 40 has two oil passages. The sixth oil passage 41 serves as the main oil passage of the cylinder block 40 and is connected to the main oil cylinder. The seventh oil passage 42 serves as the secondary oil passage of the cylinder block 40 and is connected to both the sixth oil passage 41 and the crankshaft 30, thereby sequentially exporting the oil from the main oil cylinder.

[0074] An engine includes a piston 10 cooling structure, a main cylinder, and an electronic oil pump. The main cylinder is connected to a cylinder block 40. The electronic oil pump is used to regulate the oil pressure within the main cylinder. Thus, the oil pressure within the main cylinder is regulated by the electronic oil pump.

[0075] In this embodiment, the spindle upper bearing 81 is also provided with a third oil guide hole 83, which is used to connect the seventh oil passage 42 and the second arc-shaped oil groove 52.

[0076] When cooling piston 10, see [reference needed]. Figure 4From engine ignition to the end of engine combustion, the coolant flows through the main cylinder, cylinder block 40, crankshaft 30, and connecting rod body 20 in sequence. Then, the coolant is sprayed out from the end of the connecting rod body 20 that extends into the inner cavity of the piston 10, thereby achieving spray cooling of the inner cavity of the piston 10 with high cooling efficiency.

[0077] When cooling piston 10, see Figure 4 From engine ignition to the end of engine combustion, all oil passages are in a conductive state. The corresponding cold area is arranged in the oil passages as follows: main oil cylinder, sixth oil passage 41, seventh oil passage 42, third oil guide hole 83, second arc-shaped oil groove 52, third oil passage 31, fifth oil passage 33, fourth oil passage 32, first arc-shaped oil groove 51, first oil passage 21, lower second oil guide hole 72, third arc-shaped oil groove 71, upper second oil guide hole 72 and first oil guide hole 22. Then, the coolant is sprayed into the inner cavity of piston 10 through the first oil guide hole 22.

[0078] When piston 10 is not cooled, see Figure 5 When the engine is not in the state from engine ignition to engine combustion completion, the angle of the fourth oil passage 32 and the first arc-shaped oil groove 51 is turned apart, so that the fourth oil passage 32 and the first arc-shaped oil groove 51 are not connected, thereby cutting off the cooling circuit; at this time, the oil passages connected to the main cylinder block 40 only include the main oil cylinder, the sixth oil passage 41, the seventh oil passage 42, the third oil guide hole 83, the second arc-shaped oil groove 52, the third oil passage 31, the fifth oil passage 33 and the fourth oil passage 32.

[0079] In the structural configuration of this application, the arc-shaped oil grooves include a first arc-shaped oil groove 51, a second arc-shaped oil groove 52, and a third arc-shaped oil groove 71. The first arc-shaped oil groove 51 is located on the connecting rod bearing 60, the second arc-shaped oil groove 52 is located on the main bearing 80, and the third arc-shaped oil groove 71 is located on the connecting rod bushing 70. Therefore, the advantages of not placing the arc-shaped oil grooves on the connecting rod body 20, cylinder block 40, or piston 10 are: it facilitates the formation of a stable oil film; the oil grooves are easier to machine, simpler to operate, and easier to maintain and replace; and it offers better cost control and higher reliability. In conclusion, placing the arc-shaped oil grooves on the bearing has more advantages than placing them on the shaft or crankshaft 30.

[0080] The structures, proportions, sizes, etc., illustrated in the accompanying drawings of this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the conditions under which this utility model can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportional relationships, or adjustments to the size, without affecting the effects and purposes that this utility model can produce, should still fall within the scope of the technical content disclosed in this utility model.

[0081] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified. In this utility model, unless otherwise explicitly specified and limited, the terms "installed," "connected," "joined," "fixed," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two elements or the interaction between two elements, unless otherwise explicitly specified.

[0082] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

Claims

1. A piston cooling structure for cooling the interior of an engine, characterized in that, The cooling system includes: Piston (10), Connecting rod body (20), one end of which extends into the inner cavity of the piston (10); A crankshaft (30) is provided, the other end of which is rotatably connected to the connecting rod body (20), and a first arc-shaped oil groove (51) is provided at the connection position between the two. The cylinder block (40) is rotatably connected to the crankshaft (30) and the connection position of the two is provided with a second arc-shaped oil groove (52); A switchable cooling oil passage is formed sequentially between the cylinder block (40), the crankshaft (30), and the connecting rod body (20), and the connecting rod body (20) introduces the coolant into the inner cavity of the piston (10) for cooling; the first arc-shaped oil groove (51) or the second arc-shaped oil groove (52) is a limiting oil groove in which only a section of arc-shaped area in the circumferential direction can be connected to the coolant, and the movement area of ​​the crankshaft (30) from engine ignition to the end of engine combustion corresponds to the arc-shaped area of ​​the limiting oil groove.

2. The piston cooling structure according to claim 1, characterized in that, The two ends of the connecting rod body (20) in the length direction are the large end and the small end, respectively, and the large end and the small end are provided with corresponding connecting holes; The cooling system also includes: Connecting rod top cover (61), The lower connecting rod bearing (62) and the upper connecting rod bearing (61) and the lower connecting rod bearing (62) form an annular connecting rod bearing (60). The connecting rod bearing (60) is fixedly connected to the large end of the connecting rod body (20). The connecting rod bearing (60) is sleeved on the crankshaft (30). The first arc-shaped oil groove (51) is located on the connecting rod bearing (60) and serves as the limiting oil groove.

3. The piston cooling structure according to claim 2, characterized in that, The first arc-shaped oil groove (51) is formed on the upper shell (61) of the connecting rod, and the first arc-shaped oil groove (51) is formed symmetrically along the length direction of the connecting rod body (20).

4. The piston cooling structure according to claim 2, characterized in that, The connecting rod body (20) includes: The first oil passage (21) is opened along the length direction of the connecting rod body (20) and the first oil passage (21) connects the two ends of the connecting rod body (20) along the length direction. The first oil guide hole (22) is opened at the small end of the connecting rod body (20), and the first oil guide hole (22) is opened radially; The cooling system also includes: Connecting rod bushing (70), the connecting rod bushing (70) is fixedly connected to the small end of the connecting rod body (20); The connecting rod bushing (70) has the following openings: The third arc-shaped oil groove (71) is connected to the first oil passage (21); The second oil guide hole (72) is radially opened and is connected to the first oil guide hole (22).

5. The piston cooling structure according to claim 4, characterized in that, There are at least three second oil guide holes (72), one of which is connected to the first oil passage (21), and the remaining second oil guide holes (72) are evenly distributed circumferentially; the third arc-shaped oil groove (71) is an arc-shaped segment oil groove, both ends of the arc end of the third arc-shaped oil groove (71) are connected to the second oil guide hole (72), and the middle part of the third arc-shaped oil groove (71) is connected to the first oil passage (21) through the second oil guide hole (72). The first oil passage (21) is opened along the direction of the axis of symmetry of the connecting rod body (20).

6. The piston cooling structure according to claim 1, characterized in that, The crankshaft (30) has the following openings: The third oil passage (31) is located at the end of the crankshaft (30) connected to the cylinder block (40), and the third oil passage (31) is connected to the oil passage of the cylinder block (40). The fourth oil passage (32) is located at the end of the crankshaft (30) connected to the connecting rod body (20), and the fourth oil passage (32) is connected to the oil passage of the connecting rod body (20); The fifth oil passage (33) is connected to the third oil passage (31) and the fourth oil passage (32) at its two ends.

7. The piston cooling structure according to claim 6, characterized in that, The third oil passage (31), the fourth oil passage (32) and the fifth oil passage (33) are all linearly extending oil passages; the third oil passage (31) and the fourth oil passage (32) are both opened radially along the crankshaft (30), and the fifth oil passage (33) is opened obliquely, with an acute angle between it and the radial section of the crankshaft (30).

8. The piston cooling structure according to claim 1, characterized in that, The cooling system also includes: Main shaft upper shell (81), The main shaft lower bearing (82) and the main shaft upper bearing (81) and the main shaft lower bearing (82) form an annular main shaft bearing (80), the main shaft bearing (80) is fixed on the cylinder body (40), and the second arc-shaped oil groove (52) is located on the main shaft bearing (80). The second arc-shaped oil groove (52) is a complete annular oil groove.

9. The piston cooling structure according to claim 1 or 8, characterized in that, The cylinder body (40) has the following openings: The sixth oil passage (41) is used to connect to the main oil cylinder; The seventh oil passage (42) is connected at both ends to the sixth oil passage (41) and the crankshaft (30), respectively. The coolant is introduced into the crankshaft (30) in sequence along the sixth oil passage (41) and the seventh oil passage (42).

10. An engine, characterized in that, Including the piston cooling structure as described in any one of claims 1-9, further comprising: The main hydraulic cylinder is connected to the cylinder body (40); An electronic oil pump is used to regulate the oil pressure in the master cylinder.

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