Piston cooling device and engine

Abstract

The invention discloses a piston cooling device and an engine, and relates to the technical field of vehicles, the piston cooling device comprises an air cylinder, a piston assembly and a cooling runner, the air cylinder is provided with a cylinder sleeve, an oil hole is formed in the cylinder sleeve and used for being communicated with a main oil duct of the engine, and the cooling runner is formed in a piston body. The cooling flow channel is provided with a first circulation opening formed in the circumferential side face of the piston body and a second circulation opening formed in the second end of the piston body, the piston body does circulating reciprocating motion in the air cylinder in the axial direction of the air cylinder, and when the piston body moves to the position where the oil hole corresponds to the first circulation opening in the radial direction, the piston body is cooled. And oil passes through the oil hole from the main oil duct of the engine, flows into the cooling runner from the first circulating opening and flows out from the second circulating opening, so that the piston body is cooled. Therefore, the piston cooling device provided by the invention not only can improve the piston cooling effect, but also can reduce the waste of oil.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicles, and in particular to a piston cooling device and an engine. Background Art

[0002] When the automobile engine is working, the combustion of the combustible mixture in the combustion chamber generates a large amount of heat. The combustion chamber is composed of the space surrounded by the cylinder head, cylinder liner, and piston. The cylinder head and cylinder liner are both equipped with cooling water jackets. There is a continuously circulating cooling water inside the water jacket to cool the cylinder head and cylinder liner to avoid deformation and damage of the cylinder head and cylinder liner due to excessive temperature. Since the piston moves up and down at a high speed and the piston head directly contacts the inside of the combustion chamber, the temperature of the piston head is particularly high. Generally, the piston cooling nozzle is used to spray oil into the cavity at the bottom of the piston to reduce the temperature of the piston top and avoid damage to the piston. For old models of engines, due to their relatively low power density, the temperature inside the combustion chamber is not very high. Generally, the cylinder head and cylinder liner are only cooled by the water jacket. The piston is generally not cooled to ensure that the temperature of the piston head does not exceed the temperature and the piston is not damaged. With the application of technologies such as turbocharging, the power density of the engine is getting higher and higher, the temperature of the engine combustion chamber is getting higher and higher, and the temperature of the piston head is also getting higher and higher. If the piston head is not cooled, the temperature of the piston head will exceed the allowable temperature of the piston material, resulting in damage to the piston and eventually the engine.

[0003] See also Figure 1 The prior art solution shown is generally provided with a piston cooling nozzle connected to the main oil channel of the engine on one side of the engine cylinder body, and the lubricating oil of a certain pressure is sprayed to the bottom of the piston, and the sprayed pressure oil forms a mist at the nozzle mouth, and has a certain fan shape, and the fan-shaped oil mist is sprayed to the bottom of the piston. When the interval between the bottom and the top of the piston is small, the sprayed oil can cool the top of the piston. However, when the piston cooling nozzle is used to spray the oil directly to the bottom of the piston, since the sprayed oil is in the form of oil mist, the amount of oil mist that finally reaches the top of the piston and contacts the wall thickness of the top surface of the piston is small, and a large amount of oil must be sprayed to ensure effective cooling of the top of the piston, so there are problems of poor cooling effect and high oil consumption.

[0004] See also Figure 2 The prior art solution shown in Figure 1On the basis of the scheme shown, an internal cooling oil passage is set in the thick wall at the top of the piston, and an opening is set at the bottom of the piston. The oil is directly sprayed into the opening of the cavity at the bottom of the piston through the piston cooling nozzle, and the oil fills the piston internal cooling oil passage to cool the piston head. In order to prevent the piston from hitting the piston cooling nozzle when moving up and down, the piston cooling nozzle must be set below the bottom dead center of the piston, and the piston internal cooling oil passage is set at the top of the piston, so the piston cooling nozzle is far away from the piston internal cooling oil passage, and it is difficult for the piston cooling nozzle to spray the oil into the opening of the piston internal cooling oil passage very accurately, so a large amount of oil will inevitably be sprayed to the outside, resulting in a large amount of oil waste. Summary of the invention

[0005] The main purpose of the present invention is to provide a piston cooling device, aiming to provide a piston cooling device that can improve the piston cooling effect and reduce oil waste.

[0006] To achieve the above object, the present invention provides a piston cooling device, the piston cooling device comprising:

[0007] The cylinder has a cylinder sleeve, and the cylinder sleeve is provided with an oil hole for connecting to the main oil channel of the engine;

[0008] A piston assembly, comprising a piston body movably mounted in the cylinder sleeve along the axial direction of the cylinder, wherein the piston body has a first end and a second end oppositely arranged along the axial direction of the cylinder; and

[0009] A cooling channel is formed inside the piston body, wherein the cooling channel has a first flow opening provided on a peripheral side of the piston body and a second flow opening provided on a second end of the piston body;

[0010] When the piston body moves until the oil hole corresponds to the first flow port in the radial direction, the oil flows from the main oil channel of the engine into the cooling channel.

[0011] In one embodiment, the second end of the piston body is recessed with a first groove;

[0012] The cooling channel includes a first cooling channel, a second cooling channel and a third cooling channel which are connected in sequence. The first cooling channel is arranged on the side of the first groove and along the axial direction of the cylinder. The end of the first cooling channel forms the first flow port. The second cooling channel is arranged between the first groove and the first end of the piston body. The third cooling channel is connected to the first groove, and the end of the third cooling channel forms the second flow port.

[0013] In one embodiment, the first cooling channel and / or the third cooling channel are arranged at an angle.

[0014] In one embodiment, the diameter of the oil hole is L1, the diameter of the first flow port is L2, and L1<L2.

[0015] In one embodiment, a plurality of the first cooling channels are provided, and a plurality of the first flow openings are provided correspondingly, and the plurality of the first flow openings are arranged along the axial direction of the cylinder;

[0016] The oil hole can be correspondingly communicated with at least part of the first flow opening in the radial direction of the cylinder.

[0017] In one embodiment, the piston cooling device further includes a connecting rod mechanism and a matching seat that are hingedly matched, and the matching seat is disposed in the first groove and connected to the top of the first groove.

[0018] In one embodiment, the piston cooling device further comprises a piston outer flow channel, wherein the piston outer flow channel is used to connect the oil hole and the main oil channel of the engine, and a piston cooling nozzle is provided on the piston outer flow channel to spray oil into the oil hole.

[0019] In one embodiment, a solenoid valve is further provided on the piston outer flow channel to control the opening and closing of the piston outer flow channel.

[0020] In one embodiment, the piston cooling device further comprises a plurality of piston rings, a plurality of annular grooves are provided on the circumferential side of the piston body near the first end, and the plurality of piston rings are arranged in the plurality of annular grooves and are in contact with the inner wall of the cylinder liner.

[0021] The present invention provides an engine, the engine comprising the above-mentioned piston cooling device, the piston cooling device comprising:

[0022] The cylinder has a cylinder sleeve, and the cylinder sleeve is provided with an oil hole for connecting to the main oil channel of the engine;

[0023] A piston assembly, comprising a piston body movably mounted in the cylinder sleeve along the axial direction of the cylinder, wherein the piston body has a first end and a second end oppositely arranged along the axial direction of the cylinder; and

[0024] A cooling channel is formed inside the piston body, wherein the cooling channel has a first flow opening provided on a peripheral side of the piston body and a second flow opening provided on a second end of the piston body;

[0025] When the piston body moves until the oil hole corresponds to the first flow port in the radial direction, the oil flows from the main oil channel of the engine into the cooling channel.

[0026] In the technical solution of the present invention, a cooling channel is provided inside the piston body, and the cooling channel has a first flow port provided on the peripheral side of the piston body and a second flow port provided on the second end of the piston body, so that the piston can be cooled inside the piston instead of outside the piston, and the cooling effect is better; in addition, since the oil hole is connected to the main oil channel of the engine, when the piston body moves to the point where the oil hole corresponds to the first flow port in the radial direction, the oil hole and the flow port are in a connected state, and the cold oil in the oil hole can flow into the cooling channel to cool the piston body, and then flow out of the cooling channel through the second flow port of the cooling channel. Therefore, the piston cooling device provided by the present application can not only improve the cooling effect of the piston, but also reduce the waste of oil because the oil is transported through the hole or oil channel throughout the process. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention 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 of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0028] Figure 1 It is a structural schematic diagram of a piston cooling device in the prior art;

[0029] Figure 2 It is a structural schematic diagram of a piston cooling device (using a cooling oil channel) in the prior art;

[0030] Figure 3 A schematic structural diagram of an embodiment of a piston cooling device provided by the present invention.

[0031] Description of Figure Numbers:

[0032] 100. Piston cooling device; 1. Cylinder; 11. Cylinder liner; 12. Oil hole; 2. Piston assembly; 21. Piston body; 211. First end; 212. Second end; 213. First groove; 214. Annular groove; 22. Matching seat; 3. Cooling channel; 31. First flow port; 32. Second flow port; 33. First cooling channel; 34. Second cooling channel; 35. Third cooling channel; 4. Piston outer flow channel; 41. Solenoid valve.

[0033] 1' cylinder body; 2' piston; 3' piston cooling nozzle; 4' mist oil spray area.

[0034] 1” cylinder body; 2” piston; 3” piston cooling nozzle; 4” cooling oil channel.

[0035] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0038] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features limited to "first" and "second" may explicitly or implicitly include at least one of the features. In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or solutions that satisfy both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0039] In the prior art, Figure 1 In the scheme, a piston 2' is installed in the cylinder 1', and a piston cooling nozzle 3' is provided below the lower dead center of the piston 2'. The piston cooling nozzle 3' can spray out a fan-shaped oil mist. A certain thick wall is left on the top surface of the piston 2', and the bottom of the piston 2' is generally hollowed out to reduce the weight of the piston 2'. The fan-shaped oil mist sprayed by the piston cooling nozzle 3' is sprayed into the cavity at the bottom of the piston 2' to form a mist oil spray area 4', and is sprayed to the thick wall position on the top surface of the piston 2' to cool the top of the piston 2'. Since the piston 2' needs to reciprocate up and down, the spray position of the oil mist on the top surface of the piston 2' will be different when the piston is in different positions. In the end, only part of the oil contacts the thick wall on the top surface of the piston 2', resulting in a lot of oil waste.

[0040] exist Figure 2In the scheme, a piston 2" is installed in the cylinder 1", an internal cooling oil channel is provided in the thick wall at the top of the piston 2", and an opening is provided at the bottom of the piston 2", and oil is directly sprayed into the opening of the cavity at the bottom of the piston 2" through the piston cooling nozzle 3", and the oil fills the internal cooling oil channel 4" of the piston 2" to cool the head of the piston 2". In order to prevent the piston 2" from hitting the piston cooling nozzle 3" when moving up and down, the piston cooling nozzle 3" must be set below the bottom dead center of the piston 2", and the internal cooling oil channel 4" of the piston 2" is set at the top of the piston 2", so that the piston cooling nozzle 3" is far away from the internal cooling oil channel 4" of the piston 2", and it is difficult for the piston cooling nozzle 3" to spray the oil into the opening of the internal cooling oil channel 4" of the piston 2" very accurately, so a large amount of oil will inevitably be sprayed to the outside, resulting in a lot of oil waste, and when the piston cooling nozzle 3" is turned on, the flow demand for the oil pump increases greatly, resulting in increased energy consumption of the oil pump.

[0041] The present invention provides a piston cooling device, so as to provide a piston cooling device which can improve the piston cooling effect and reduce the waste of oil.

[0042] See also Figure 3 In one embodiment of the present invention, the piston cooling device 100 includes a cylinder 1, a piston assembly 2 and a cooling channel 3, wherein the cylinder 1 has a cylinder sleeve 11, and an oil hole 12 is opened on the cylinder sleeve 11 for connecting to the main oil channel of the engine; the piston assembly 2 includes a piston body 21 movably installed in the cylinder sleeve 11 along the axial direction of the cylinder 1, and the piston body 21 has a first end 211 and a second end 212 arranged oppositely along the axial direction of the cylinder 1; the cooling channel 3 is formed inside the piston body 21, and the cooling channel 3 has a first flow port 31 arranged on the peripheral side of the piston body 21 and a second flow port 32 arranged at the second end 212 of the piston body 21; wherein, when the piston body 21 moves to the point where the oil hole 12 corresponds to the first flow port 31 in the radial direction, the oil flows from the main oil channel of the engine into the cooling channel 3.

[0043] In the technical solution of the present invention, by arranging a cooling channel 3 inside the piston body 21, the cooling channel 3 has a first flow port 31 arranged on the side surface of the piston body 21 and a second flow port 32 arranged on the second end 212 of the piston body 21, so that the piston can be cooled inside the piston instead of cooling the piston outside the piston, and the cooling effect of cooling the piston inside the piston is better; in addition, since the oil hole 12 is connected to the main oil channel of the engine, when the piston body 21 moves to the oil hole 12 and the first flow port 31 correspond in the radial direction, the oil hole 12 and the first flow port 31 are in a connected state, and the cold oil in the oil hole 12 can flow into the cooling channel to cool the piston body 21, and then flow out of the cooling channel through the second flow port 32 of the cooling channel. Therefore, the piston cooling device 100 provided by the present application can not only improve the piston cooling effect, but also reduce the waste of oil because the oil (coolant) is transported through the hole or oil channel throughout the process.

[0044] It should be noted that the crankcase is the space formed by the engine oil pan, cylinder block (cylinder liner 11), and cylinder head, and the cavity at the bottom of the piston is connected to the crankcase. In this application, the cylinder 1 is installed in the engine up and down as an example, and the piston moves up and down in the cylinder 1. However, it is not limited to the cylinder 1 being installed in the engine up and down. When the cylinder 1 is not installed in the engine up and down, the upward movement is the movement in the direction close to the cylinder 1 head, and the downward movement is the movement away from the cylinder 1 head. The up and down do not refer to the general up and down. Up refers to the direction of the piston toward the cylinder head, and down refers to the direction of the piston away from the cylinder head. In addition, the bottom dead center of the piston refers to the position when the piston top is the smallest distance from the center of the crankshaft, that is, the position when the piston top is the largest distance from the cylinder head; the top dead center of the piston refers to the position where the piston top is farthest from the center of the crankshaft, that is, the position when the piston top is the smallest distance from the cylinder head.

[0045] In some embodiments, when the piston body is at the bottom dead center position, the first flow port 31 of the cooling channel 3 in the piston body is exactly aligned with the oil hole 12 opened on the cylinder sleeve 11, and the pressure oil from the main oil channel of the engine is directly sprayed to the first flow port 31 on the side of the piston body 21 and the top of the piston is cooled by filling the cooling oil channel. When the piston continues to move upward from the bottom dead center, the small oil hole 12 on the cylinder sleeve 11 is staggered from the first flow port 31, and the oil cannot enter the cooling channel 3 at this time. At this time, the main oil channel can be controlled to stop transporting oil to avoid wasting oil. In addition, due to the high-speed upward movement of the piston body, the cavity at the bottom of the piston connected to the crankcase will generate negative pressure, and the negative pressure can extract the oil in the cooling channel 3, so as to form a suction and emptying of the oil in the cooling channel 3.

[0046] Further, the second end 212 of the piston body 21 is concavely provided with a first groove 213; the cooling channel 3 includes a first cooling channel 33, a second cooling channel 34 and a third cooling channel 35 which are connected in sequence, the first cooling channel 33 is arranged at the side of the first groove 213 and arranged along the axial direction of the cylinder, the end of the first cooling channel 33 forms the first flow opening 31, the second cooling channel 34 is arranged between the first groove 213 and the first end 211 of the piston body 21, the third cooling channel 35 is connected with the first groove 213, and the end of the third cooling channel 35 forms the second flow opening 32. The first end 211 of the piston body 21 directly contacts the interior of the combustion chamber, so the temperature of the first end 211 of the piston body 21 is particularly high and needs to be cooled down. The second cooling channel 34 is arranged between the first groove 213 and the first end 211 of the piston body 21, which can cool down the first end 211 of the piston body 21 more efficiently. Among them, the second cooling channel 34 can be an annular cavity or a cylindrical cavity formed between the first groove 213 and the first end 211 of the piston body 21, so as to quickly and efficiently cool the first end 211 of the piston body 21. Since the second cooling oil channel and the oil hole 12 on the cylinder 1 are not on the same radial plane of the cylinder 1, and the radial plane of the cylinder 1 is a plane perpendicular to the axial direction of the cylinder 1, that is, the second cooling oil channel and the oil hole 12 on the cylinder 1 are not at the same or similar axial height of the cylinder 1, therefore, the first cooling oil channel is used to connect the oil hole 12 and the second cooling oil channel; the third cooling oil channel is used to discharge the oil in the second cooling oil channel. It can be understood that the first groove 213 is connected to the cavity at the bottom of the piston, that is, connected to the crankcase. Therefore, when the piston body moves upward at high speed, negative pressure will be generated in the cavity at the bottom of the piston connected to the crankcase. The negative pressure can draw the oil in the second cooling channel 34 through the third cooling channel 35, thereby sucking and draining the oil in the cooling channel 3.

[0047] It should be noted that the first cooling channel 33 is arranged on the side of the first groove 213 and arranged along the axial direction of the cylinder, which means that the first cooling channel 33 connects the second cooling channel 34 and the first flow port 31 respectively located on different radial planes of the cylinder 1, so it is generally arranged along the axial direction of the cylinder. In most practical cases, the first cooling channel 33 is arranged at an angle relative to the axial direction of the cylinder to connect the first flow port 31 and the second cooling channel 34, and transport the oil to the second cooling channel 34.

[0048] As for the specific setting of the third cooling channel 35, as long as the second cooling channel 34 can be connected to the groove, the third cooling channel 35 can be connected to the bottom wall of the groove or the side wall of the groove. In some embodiments, the third cooling channel 35 is inclined, and the third cooling channel 35 is connected to the bottom wall of the groove to better extract the oil in the second cooling channel 34.

[0049] It can be understood that the inclination direction of the first cooling channel 33 and the third cooling channel 35 can be consistent, or they can be inclined in different directions; the inclination amplitude of the first cooling channel 33 and the third cooling channel 35 can be consistent, or they can be inclined at different amplitudes, and the present invention is not limited here.

[0050] In order to allow most of the oil to flow into the cooling channel 3, the diameter of the oil hole 12 is L1, and the diameter of the first circulation port 31 is L2, where L1<L2. In addition, the diameter of the oil hole 12 can also be set to be the same as the diameter of the first circulation port 31, so that most of the oil can flow into the cooling channel 3; if the diameter of the oil hole 12 is larger than the diameter of the first circulation port 31, more oil will not be able to enter the cooling channel 3, resulting in a waste of oil. Therefore, the diameter of the oil hole 12 is smaller than the diameter of the first circulation port 31, which can further reduce the waste of oil.

[0051] In addition, when the aperture of the first flow port 31 in the axial direction of the cylinder 1 is larger than the aperture of the oil hole 12 in the axial direction of the cylinder 1, the cooling channel 3 can be replenished with oil for a longer time during the upward movement of the piston body from the bottom dead center, thereby controlling the amount of oil entering the cooling channel 3 in the piston.

[0052] Alternatively, the distance the piston moves upward from the bottom dead center can be controlled by setting the opening area of ​​the first flow port 31, and the first flow port 31 and the oil hole 12 can be relatively connected to control the amount of oil entering the cooling oil jacket in the piston.

[0053] In some other embodiments, the first cooling flow channel 33 is provided with a plurality of first flow openings 31, and the plurality of first flow openings 31 are arranged along the axial direction of the cylinder 1; the oil hole 12 can be correspondingly connected with at least part of the first flow openings 31 in the radial direction of the cylinder 1. With such an arrangement, the cooling oil jacket can be filled with oil multiple times during the movement of the piston body.

[0054] In addition, multiple oil holes 12 or oil holes 12 with larger apertures in the axial direction (long oil holes 12) may be provided on the cylinder liner 11, so that the cooling oil jacket can be filled with oil multiple times during the upward movement of the piston from the bottom dead center. However, as mentioned above, this solution will lead to a waste of oil, which will not be elaborated in the present invention.

[0055] Since the oil can be replenished only during the period when the piston is at the bottom dead point and moves upward, the cooling oil channel in the piston is filled with oil, and the oil is directly sprayed into the cooling channel 3 through the aligned oil hole 12. All the oil enters the cooling channel 3, avoiding the waste of cooling oil.

[0056] Furthermore, the piston assembly 2 further includes a hinged connecting rod mechanism and a matching seat 22, wherein the matching seat 22 is disposed in the first groove 213 and connected to the top of the first groove 213. Specifically, the matching seat 22 includes a piston pin and a pin seat, and the piston pin can transmit the gas pressure borne by the piston body to the connecting rod mechanism, thereby converting the reciprocating motion of the piston body into the rotational motion of the crankshaft.

[0057] Furthermore, the piston cooling device 100 further includes a piston outer flow channel 4, which is used to connect the oil hole 12 and the main oil channel of the engine. The piston outer flow channel 4 is provided with a piston cooling nozzle to spray oil into the oil hole 12. With such a configuration, the piston cooling nozzle can spray oil into the oil hole 12 at an appropriate pressure and flow rate. The oil hole 12 is connected to the main oil channel of the engine through the piston outer flow channel 4, and can directly obtain oil (engine oil) from the main oil channel. This method allows the cooling oil to be supplied continuously and stably, thereby improving the cooling efficiency.

[0058] Furthermore, a solenoid valve 41 is provided on the piston outer flow channel 4 to control the opening and closing of the piston outer flow channel 4. When the engine is running, it is determined whether the piston needs to be cooled according to the engine load. When the engine load is greater than the threshold, the solenoid valve 41 is controlled to be connected, and the lubricating oil in the main oil channel of the engine enters the piston outer flow channel 4, and then flows to the joint surface of the cylinder liner 11 and the piston body 21 through the oil hole 12.

[0059] Take a four-stroke engine as an example. A four-stroke engine has four strokes: intake, compression, power, and exhaust. The pistons move downward during the intake and power strokes, and upward during the compression and exhaust strokes. When the engine load is greater than the threshold, it is determined that the solenoid valve 41 needs to be opened. When the camshaft phase sensor measures that the piston is at the bottom dead center, the solenoid valve 41 is opened, and the engine oil in the main oil channel of the engine flows to the piston outer flow channel 4, and flows to the first flow port 31 located on the piston body 21 through the oil hole 12. At this time, since the piston is at the bottom dead center, the first flow port 31 is exactly aligned with the oil hole 12 opened on the cylinder sleeve 11. The pressure oil from the main oil channel of the engine is directly sprayed to the first flow port 31 located on the piston body 21 and flows into the second cooling flow channel 34 through the first cooling flow channel 33, and fills the entire second cooling flow channel 34 to cool the top of the piston. When the piston body 21 continues to move upward from the bottom dead center, the oil hole 12 on the cylinder body is offset from the first flow port 31, and the oil cannot enter the cooling channel 3. At this time, the solenoid valve 41 can be controlled to be disconnected to avoid wasting oil. In addition, the crankcase will generate negative pressure in the cavity at the bottom of the piston due to the upward high-speed movement of the piston, and the negative pressure will extract the oil in the cooling channel 3, thereby sucking and draining the oil in the cooling channel 3.

[0060] Furthermore, the piston cooling device 100 also includes a plurality of piston rings. A plurality of annular grooves 214 are provided on the circumference of the piston body 21 near the first end 211. The plurality of piston rings are provided in the plurality of annular grooves 214 and are in contact with the inner wall of the cylinder liner 11. There is a small gap between the piston body 21 and the cylinder liner 11, and a plurality of piston rings are provided at the upper position of the piston. The uppermost piston ring is used to seal the high-temperature and high-pressure gas in the combustion chamber, and the other piston rings are used to scrape off the oil on the cylinder liner 11 to prevent the oil from entering the combustion chamber and burning, resulting in high oil consumption. The outer side of the piston body and the cylinder liner 11 are filled with oil to form an oil film, which can lubricate the reciprocating motion of the piston and also form a certain sealing effect between the piston and the cylinder liner 11.

[0061] The present invention further proposes an engine, which includes a piston cooling device 100. The specific structure of the piston cooling device 100 refers to the above embodiment. Since the engine adopts all the technical solutions of all the above embodiments, it at least has all the beneficial effects brought by the technical solutions of the above embodiments, which will not be described one by one here.

[0062] The above description is only an exemplary embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the technical concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A piston cooling device, characterized in that: The piston cooling device comprises: The cylinder has a cylinder sleeve, and the cylinder sleeve is provided with an oil hole for connecting to the main oil channel of the engine; A piston assembly, comprising a piston body movably mounted in the cylinder sleeve along the axial direction of the cylinder, wherein the piston body has a first end and a second end oppositely arranged along the axial direction of the cylinder; and A cooling channel is formed inside the piston body, wherein the cooling channel has a first flow opening provided on a peripheral side of the piston body and a second flow opening provided on a second end of the piston body; When the piston body moves until the oil hole corresponds to the first flow port in the radial direction, the oil flows from the main oil channel of the engine into the cooling channel.

2. The piston cooling device according to claim 1, characterized in that: The second end of the piston body is concavely provided with a first groove; The cooling channel includes a first cooling channel, a second cooling channel and a third cooling channel which are connected in sequence. The first cooling channel is arranged on the side of the first groove and along the axial direction of the cylinder. The end of the first cooling channel forms the first flow port. The second cooling channel is arranged between the first groove and the first end of the piston body. The third cooling channel is connected to the first groove, and the end of the third cooling channel forms the second flow port.

3. The piston cooling device according to claim 2, characterized in that: The first cooling channel and / or the third cooling channel are arranged at an inclination.

4. The piston cooling device according to claim 2, characterized in that: The diameter of the oil hole is L1, the diameter of the first flow port is L2, and L1<L2.

5. The piston cooling device according to claim 2, characterized in that: The first cooling flow channels are provided in plurality, and the first flow openings are provided correspondingly, and the first flow openings are arranged along the axial direction of the cylinder; The oil hole can be correspondingly communicated with at least part of the first flow opening in the radial direction of the cylinder.

6. The piston cooling device according to claim 2, characterized in that: The piston cooling device further comprises a connecting rod mechanism and a matching seat which are hingedly matched. The matching seat is arranged in the first groove and connected to the top of the first groove.

7. The piston cooling device according to claim 1, characterized in that: The piston cooling device further comprises a piston outer flow channel, which is used to connect the oil hole and the main oil channel of the engine. A piston cooling nozzle is provided on the piston outer flow channel to spray oil into the oil hole.

8. The piston cooling device according to claim 7, characterized in that: The piston outer flow channel is also provided with an electromagnetic valve to control the opening and closing of the piston outer flow channel.

9. The piston cooling device according to claim 1, characterized in that: The piston cooling device further comprises a plurality of piston rings. A plurality of annular grooves are provided on the peripheral side of the piston body near the first end. The plurality of piston rings are arranged in the plurality of annular grooves and are in contact with the inner side wall of the cylinder sleeve.

10. An engine, characterized in that: The engine comprises a piston cooling device according to any one of claims 1 to 9.

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