Piston cooling nozzle and design method thereof

Abstract

The invention relates to the technical field of engines, and discloses a piston cooling nozzle and a design method thereof. The first valve seat is arranged on the valve main body; the second valve seat is arranged on the valve main body; the first control valve is arranged on the first valve seat; the second control valve is arranged on the second valve seat; the first cooling nozzle is arranged on the first valve seat and communicates with an inner cavity of the first valve seat, and the second cooling nozzle is arranged on the second valve seat and communicates with an inner cavity of the second valve seat. According to the cooling nozzle, engine oil jets jetted by the cooling nozzle are jetted to different proper positions on the surface of the inner cavity of the piston, so that more positions of the piston can be cooled, the cooling effect is improved to the maximum extent, the thermal stress of the piston is reduced, the service life of the piston and an engine is prolonged, the cost is reduced, and the thermal load of a combustion system is reduced; the whole vehicle reliability is improved.

Description

Technical Field

[0001] The invention relates to the technical field of engines, and in particular to a piston cooling nozzle and a design method of a piston cooling nozzle. Background Art

[0002] During the operation of the engine, due to the high temperature and mechanical friction generated by fuel combustion, the piston is in a high temperature and high pressure load state for a long time. In order to ensure the performance of the piston and extend the service life of the piston, the piston needs to be effectively cooled. In the related art, a piston cooling nozzle is used to spray the engine oil into the inner cavity of the piston top, the piston inner cooling oil channel or the piston skirt position to achieve the cooling effect.

[0003] However, the current piston cooling nozzle structure usually has some limitations. In the process of cooling nozzle design, the pressure is often controlled by the valve body of the nozzle. When the oil pressure is greater than the set threshold, the valve mouth is opened and the cooling nozzle sprays oil to cool the piston. If the threshold is set too high, the piston cannot be fully cooled, affecting the life of the piston; if the threshold is set too low, it will cause oil waste and affect fuel economy. Due to uneven piston cooling or local overcooling of the piston, piston material fatigue may occur, shortening the service life of the piston. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems in the related art to a certain extent. To this end, the first purpose of the present invention is to propose a piston cooling nozzle, which can cool more positions of the piston by spraying the oil beam sprayed by the cooling nozzle to different appropriate positions on the inner surface of the piston, so as to maximize the cooling effect and further improve the uniformity of piston cooling. Under the premise of simplifying the positioning design of the cooling nozzle, the assembly accuracy can be effectively improved, and the clearance requirements between the cooling nozzle and other parts can be minimized. The compact design of the cooling nozzle can be achieved, which is suitable for engines of various cylinder diameters. The cooling nozzle structure has a fast response, can provide more cooling flow when needed, and reduce the cooling flow when not needed, thereby improving the cooling efficiency. By improving the uniformity of piston cooling, the thermal stress of the piston is reduced, the service life of the piston and the engine is extended, the cost is reduced, the thermal load of the combustion system is reduced, and the reliability of the whole vehicle is improved.

[0005] A second object of the present invention is to provide a design method for a piston cooling nozzle.

[0006] To achieve the above-mentioned purpose, a first embodiment of the present invention proposes a piston cooling nozzle, comprising: a valve body; a first valve seat, the first valve seat is arranged on the valve body; a second valve seat, the second valve seat is arranged on the valve body; a first control valve, the first control valve is arranged on the first valve seat, the inner cavity of the first control valve is selectively connected with the inner cavity of the first valve seat, and the inner cavity of the first valve seat is connected with the oil passage of the target engine cylinder; the first control valve is configured to perform an opening or closing action according to the oil pressure of the target engine cylinder; the second control valve, the second control valve is arranged on the second valve seat, and the second control valve is connected to the second valve seat. The inner cavity of the control valve is selectively connected to the inner cavity of the second valve seat, and the inner cavity of the second valve seat is connected to the oil channel of the target engine cylinder; the second control valve is configured to perform an opening or closing action according to the oil pressure and oil temperature of the target engine cylinder; a first cooling nozzle, the first cooling nozzle is arranged on the first valve seat and connected to the inner cavity of the first valve seat, and the first cooling nozzle is used to cool the first load area of ​​the target piston; a second cooling nozzle, the second cooling nozzle is arranged on the second valve seat and connected to the inner cavity of the second valve seat, and the second cooling nozzle is used to cool the second load area of ​​the target piston.

[0007] In addition, the piston cooling nozzle according to the above embodiment of the present invention may also have the following additional technical features:

[0008] According to some embodiments of the present invention, the valve body is provided with a first limiting hole, and the first valve seat passes through the first limiting hole and is fixedly disposed on the valve body.

[0009] According to some embodiments of the present invention, the valve body is provided with a second limiting hole, and the second valve seat passes through the second limiting hole and is fixedly disposed on the valve body.

[0010] According to some embodiments of the present invention, the inner contour of the first valve seat is provided with an internal thread structure, the outer contour of the first control valve is provided with an external thread structure, the first control valve passes through the first valve seat and is fixed to the first valve seat through the external thread structure cooperating with the internal thread structure of the first valve seat; the first control valve cooperates with the first preset through hole of the target engine cylinder body through the internal thread structure, so that the inner cavity of the first control valve is connected with the oil channel of the target engine cylinder body through the first preset through hole.

[0011] According to some embodiments of the present invention, the bottom of the second control valve cooperates with a second preset through hole of the target engine cylinder block so that the inner cavity of the second control valve communicates with the oil passage of the target engine cylinder block through the second preset through hole.

[0012] According to some embodiments of the present invention, a sealing ring is provided at a connection between the second valve seat and the oil passage of the target engine cylinder block.

[0013] According to some embodiments of the present invention, the first control valve includes a first sealing cover plate, a first pressure spring and a first plunger; one end of the first pressure spring is connected to the first sealing cover plate, and the other end of the first pressure spring is connected to the first plunger; the first plunger is used to generate a force on the first pressure spring under the action of the oil pressure of the target engine cylinder block, so as to compress the first pressure spring and drive the first plunger to move in the compression direction of the first pressure spring to control the connection state between the inner cavity of the first control valve and the oil channel of the target engine cylinder block.

[0014] According to some embodiments of the present invention, the second control valve includes a second sealing cover plate, a temperature and pressure spring assembly and a second plunger; the temperature and pressure spring assembly includes a second pressure spring and a temperature control spring; one end of the temperature and pressure spring assembly is connected to the second sealing cover plate, and the other end of the temperature and pressure spring assembly is connected to the second plunger; the second plunger is used to generate a force on the second pressure spring under the action of the oil pressure of the target engine cylinder block, so as to compress the second pressure spring and drive the second plunger to move in the compression direction of the second pressure spring to control the connection state between the inner cavity of the second control valve and the oil channel of the target engine cylinder block; or / and, the temperature control spring is used to generate a compression amount under the action of the oil temperature of the target engine cylinder block, drive the second plunger to move in the compression direction of the temperature control spring to control the connection state between the inner cavity of the second control valve and the oil channel of the target engine cylinder block.

[0015] A piston cooling nozzle according to an embodiment of the present invention comprises: a valve body; a first valve seat, the first valve seat being arranged on the valve body; a second valve seat, the second valve seat being arranged on the valve body; a first control valve, the first control valve being arranged on the first valve seat, the inner cavity of the first control valve being selectively communicated with the inner cavity of the first valve seat, and the inner cavity of the first valve seat being communicated with the oil passage of a target engine cylinder; the first control valve being configured to perform an opening or closing action according to an oil pressure of the target engine cylinder; a second control valve, the second control valve being arranged on the second valve seat, the inner cavity of the second control valve being selectively communicated with the inner cavity of the second valve seat, and the inner cavity of the second valve seat being communicated with the oil passage of the target engine cylinder; the second control valve being configured to perform an opening or closing action according to an oil pressure and an oil temperature of the target engine cylinder; a first cooling nozzle, the first cooling nozzle being arranged on the first valve seat and being communicated with the inner cavity of the first valve seat, and the first cooling nozzle being used to cool a first load zone of the target piston; a second cooling nozzle, the second cooling nozzle being arranged on the second valve seat and being communicated with the inner cavity of the second valve seat, and the second cooling nozzle being used to cool a second load zone of the target piston. Therefore, the cooling nozzle can cool more parts of the piston by spraying the oil beam sprayed by the cooling nozzle to different appropriate positions on the inner surface of the piston, so as to maximize the cooling effect and further improve the uniformity of piston cooling. Under the premise of simplifying the positioning design of the cooling nozzle, the assembly accuracy can be effectively improved and the clearance requirement between the cooling nozzle and other parts can be minimized. The compact design of the cooling nozzle can be realized, which is suitable for engines of various cylinder diameters. The cooling nozzle structure has a fast response and can provide more cooling flow when needed, and reduce the cooling flow when not needed, thereby improving the cooling efficiency. By improving the uniformity of piston cooling, the thermal stress of the piston is reduced, the service life of the piston and the engine is extended, the cost is reduced, the thermal load of the combustion system is reduced, and the reliability of the whole vehicle is improved.

[0016] The second purpose of the present invention is to propose a design method for a piston cooling nozzle, which determines whether the piston cooling nozzle is working in combination with the actual operating conditions of the whole machine, and accurately controls the injection direction and amount of the engine oil when the piston cooling nozzle is working. At the same time, from the cooling system level, the demand for the oil pump capacity is reduced as much as possible, and energy waste is reduced, thereby further improving fuel economy and the thermal efficiency of the whole machine, effectively reducing the deviations that may be caused by experience-based design, and improving design efficiency.

[0017] To achieve the above-mentioned purpose, a second embodiment of the present invention proposes a method for designing a piston cooling nozzle, including: determining a first load zone and a second load zone for cooling a target piston, and determining a first injection angle of the first cooling nozzle according to the position of the first load zone, and determining a second injection angle of the second cooling nozzle according to the position of the second load zone; determining a first rated flow rate of a first control valve and a second rated flow rate of a second control valve according to the maximum operating temperature of the target piston, determining a first caliber of the first cooling nozzle according to the first rated flow rate and an average linear velocity of the target piston, and determining a second caliber of the second cooling nozzle according to the second rated flow rate and an average linear velocity of the target piston; determining a first opening pressure threshold of the first control valve and a second opening pressure threshold of the second control valve according to an oil pressure curve and an oil temperature curve of a target engine cylinder. opening pressure threshold; determining a first preload and a first spring stiffness of a first pressure spring in a first control valve according to the first opening pressure threshold, determining a second preload and a second spring stiffness of a second pressure spring in a second control valve according to the second opening pressure threshold, and determining a third preload and a third spring stiffness of a temperature control spring in a second control valve according to the second opening pressure threshold; determining first design parameters of a first control valve and a first cooling nozzle according to a first injection angle, a first caliber, a first opening pressure threshold, a first preload and a first spring stiffness; determining second design parameters of a second control valve and a second cooling nozzle according to a second injection angle, a second caliber, a second opening pressure threshold, a second preload, a second spring stiffness, a third preload and a third spring stiffness; and designing a piston cooling nozzle according to the first design parameters and the second design parameters.

[0018] In addition, the design method of the piston cooling nozzle according to the above embodiment of the present invention may also have the following additional technical features:

[0019] According to some embodiments of the present invention, determining a first load zone and a second load zone for cooling a target piston includes: establishing a finite element model of a target piston and a piston cooling nozzle according to an operating condition of a target engine and structural parameters of a target engine cylinder; determining a temperature field distribution of the target piston according to the finite element model; and determining a first load zone and a second load zone of the target piston according to the temperature field distribution.

[0020] According to the design method of the piston cooling nozzle of the embodiment of the present invention, a first load zone and a second load zone for cooling the target piston are determined, and a first spray angle of the first cooling nozzle is determined according to the position of the first load zone, and a second spray angle of the second cooling nozzle is determined according to the position of the second load zone; a first rated flow rate of the first control valve and a second rated flow rate of the second control valve are determined according to the maximum operating temperature of the target piston, a first caliber of the first cooling nozzle is determined according to the first rated flow rate and the average linear velocity of the target piston, and a second caliber of the second cooling nozzle is determined according to the second rated flow rate and the average linear velocity of the target piston; a first opening pressure threshold of the first control valve and a second opening pressure threshold of the second control valve are determined according to the oil pressure curve and the oil temperature curve of the target engine cylinder; The first opening pressure threshold determines the first preload and the first spring stiffness of the first pressure spring in the first control valve, the second preload and the second spring stiffness of the second pressure spring in the second control valve are determined according to the second opening pressure threshold, and the third preload and the third spring stiffness of the temperature control spring in the second control valve are determined according to the second opening pressure threshold; the first design parameters of the first control valve and the first cooling nozzle are determined according to the first injection angle, the first caliber, the first opening pressure threshold, the first preload and the first spring stiffness; the second design parameters of the second control valve and the second cooling nozzle are determined according to the second injection angle, the second caliber, the second opening pressure threshold, the second preload, the second spring stiffness, the third preload and the third spring stiffness; the piston cooling nozzle is designed according to the first design parameters and the second design parameters. Therefore, this method determines whether the piston cooling nozzle is working in combination with the actual operating conditions of the whole machine, and accurately controls the injection direction and injection amount of the piston cooling nozzle when the piston cooling nozzle is working. At the same time, it reduces the demand for the oil pump capacity from the cooling system level as much as possible, reduces energy waste, and can further improve fuel economy, further improve the thermal efficiency of the whole machine, effectively reduce the deviation that may be caused by experience-based design, and improve design efficiency.

[0021] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic diagram of a piston cooling nozzle according to some embodiments of the present invention;

[0023] Figure 2 A top view of a piston cooling nozzle according to some embodiments of the present invention;

[0024] Figure 3 is a cross-sectional view of a piston cooling nozzle according to some embodiments of the present invention;

[0025] Figure 4 is a flow chart of a method for designing a piston cooling nozzle according to some embodiments of the present invention;

[0026] Figure 5 The present invention is a flowchart of a method for designing a piston cooling nozzle according to some other embodiments of the present invention.

[0027] Description of Reference Numerals

[0028] Valve body 1, first control valve 2, first sealing cover plate 21, first pressure spring 22, first plunger 23, second control valve 3, second sealing cover plate 31, valve plate 32, second plunger 33, second pressure spring 34, temperature control spring 35, sealing ring 4, first cooling nozzle 5, second cooling nozzle 6, first valve seat 7 and second valve seat 8. DETAILED DESCRIPTION

[0029] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

[0030] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present invention should be understood by people with ordinary skills in the field to which the present invention belongs. The "first", "second" and similar words used in the embodiments of the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0031] As mentioned in the background technology section, during the operation of the engine, due to the high temperature and mechanical friction generated by fuel combustion, the piston is in a high temperature and high pressure load state for a long time. In order to ensure the performance of the piston and extend the service life of the piston, the piston needs to be effectively cooled. In the related art, a piston cooling nozzle is used to spray engine oil into the inner cavity of the piston top, the piston inner cooling oil channel or the piston skirt position to achieve a cooling effect.

[0032] In the process of realizing the present invention, the applicant discovered that the current piston cooling nozzle structure usually has some limitations. In the process of designing the cooling nozzle, the pressure is often controlled by the valve body of the nozzle. When the oil pressure is greater than the set threshold, the valve mouth is opened and the cooling nozzle sprays oil to cool the piston. If the threshold is set too high, the piston cannot be fully cooled, affecting the life of the piston; if the threshold is set too low, it will cause oil waste and affect fuel economy. Due to uneven cooling of the piston or partial overcooling of the piston, piston material fatigue may occur, shortening the service life of the piston.

[0033] In the related art, the opening and closing of the piston cooling nozzle is also adjusted by an electronic control unit to adapt to different working conditions. However, this structure usually requires the installation of an additional nozzle electronic control valve, which increases the complexity and cost of the system. A more uniform cooling effect is also achieved by using a multi-nozzle nozzle, but it is poor in intelligent adjustment and adaptive control.

[0034] The following describes a piston cooling nozzle and a design method of a piston cooling nozzle according to an embodiment of the present invention with reference to the accompanying drawings.

[0035] refer to Figure 1 , which is a schematic diagram of a piston cooling nozzle according to some embodiments of the present invention.

[0036] The piston cooling nozzle of the present invention comprises a valve body 1 , a first valve seat 7 , a second valve seat 8 , a first control valve 2 , a second control valve 3 , a sealing ring 4 , a first cooling nozzle 5 and a second cooling nozzle 6 .

[0037] refer to Figure 2 , is a top view of a piston cooling nozzle according to some embodiments of the present invention, the valve body 1 is provided with a first limiting hole (not shown in the figure), and the first valve seat 7 passes through the first limiting hole and is fixedly arranged on the valve body 1. By providing the first limiting hole, safety can be improved, control accuracy can be enhanced, automatic control can save manpower, mechanical stability and reliability can be improved, debugging and maintenance can be facilitated, and product durability can be improved.

[0038] The first cooling nozzle 5 is disposed on the first valve seat 7 and communicated with the inner cavity of the first valve seat 7. The first cooling nozzle 5 is used to cool the first load zone of the target piston. By spraying the oil beam sprayed by the first cooling nozzle 5 to the appropriate position of the inner cavity surface of the piston, more positions of the piston can be cooled to maximize the cooling effect and further improve the uniformity of piston cooling.

[0039] The first control valve 2 is arranged on the first valve seat 7, and the inner cavity of the first control valve 2 is selectively connected with the inner cavity of the first valve seat 7, and the inner cavity of the first valve seat 7 is connected with the oil channel of the target engine cylinder. The first control valve 2 is used to perform an opening or closing action according to the oil pressure of the target engine cylinder.

[0040] In some embodiments, the positioning between the first valve seat 7 and the target engine cylinder block allows the use of other positioning forms, such as a combination of cylindrical pin + diamond pin or positioning ring + bolt, as long as precise positioning can be achieved through the external structure of the two control valves.

[0041] The inner contour of the first valve seat 7 is provided with an internal thread structure, and the outer contour of the first control valve 2 is provided with an external thread structure. The first control valve 2 passes through the first valve seat 7 and is fixed to the first valve seat 7 through the external thread structure cooperating with the internal thread structure of the first valve seat 7. The first control valve 2 cooperates with the first preset through hole of the target engine cylinder block through the internal thread structure, so that the inner cavity of the first control valve 2 is connected with the oil channel of the target engine cylinder block through the first preset through hole.

[0042] refer to Figure 3 , is a cross-sectional view of a piston cooling nozzle according to some embodiments of the present invention, wherein the first control valve 2 includes a first sealing cover plate 21, a first pressure spring 22 and a first plunger 23, wherein the first sealing cover plate 21 may be a blocking cover plate, and the first plunger 23 may also be replaced with a ball valve structure. One end of the first pressure spring 22 is connected to the first sealing cover plate 21, and the other end of the first pressure spring 22 is connected to the first plunger 23. The first plunger 23 is used to generate a force on the first pressure spring 22 under the action of the oil pressure of the target engine cylinder body, so as to compress the first pressure spring 22, drive the first plunger 23 to move in the compression direction of the first pressure spring 22, so as to control the communication state between the inner cavity of the first control valve 2 and the oil channel of the target engine cylinder body.

[0043] It should be explained that the first plunger 23 has a faster response speed and can provide a larger flow rate.

[0044] Continue to refer Figure 2 The valve body 1 is provided with a second limiting hole (not shown in the figure), and the second valve seat 8 passes through the second limiting hole and is fixedly arranged on the valve body 1. By providing the second limiting hole, safety can be improved, control accuracy can be enhanced, automatic control can save manpower, mechanical stability and reliability can be improved, debugging and maintenance can be facilitated, and product durability can be improved.

[0045] The second cooling nozzle 6 is disposed on the second valve seat 8 and communicated with the inner cavity of the second valve seat 8. The second cooling nozzle 6 is used to cool the second load zone of the target piston. By spraying the oil beam sprayed by the second cooling nozzle 6 to the appropriate position of the inner cavity surface of the piston, more positions of the piston can be cooled to maximize the cooling effect and further improve the uniformity of piston cooling.

[0046] The second control valve 3 is arranged on the second valve seat 8, and the inner cavity of the second control valve 3 is selectively connected with the inner cavity of the second valve seat 8, and the inner cavity of the second valve seat 8 is connected with the oil channel of the target engine cylinder block. The second control valve 3 is used to perform an opening or closing action according to the oil pressure and oil temperature of the target engine cylinder block.

[0047] In some embodiments, the positioning between the second valve seat 8 and the target engine cylinder block allows the use of other positioning forms, such as a combination of cylindrical pin + diamond pin or positioning ring + bolt, as long as precise positioning can be achieved through the external structure of the two control valves.

[0048] The bottom of the second control valve 3 cooperates with the second preset through hole of the target engine cylinder body, so that the inner cavity of the second control valve 3 is connected with the oil passage of the target engine cylinder body through the second preset through hole.

[0049] It should be explained that the current control valve and valve body are usually positioned by means of locating pins. The types of locating pins include external conical locating pins, cylindrical locating pins and threaded locating pins, etc. They achieve precise positioning through different structural characteristics and functional uses. For example, external conical locating pins are suitable for occasions that bear radial and axial loads, while cylindrical locating pins are suitable for occasions that require frequent disassembly and assembly. However, due to the matching clearance between the locating pin and the locating hole, the clearance value when positioning each workpiece is relatively arbitrary, which will affect the stability of the workpiece processing quality. The locating pin may lose its positioning accuracy due to wear or deformation during use, requiring regular inspection and maintenance. Due to the influence of factors such as movement and vibration, some positioning components may become loose or deformed, which may lead to positioning failure.

[0050] However, the second control valve 3 of the present invention is installed integrally with the valve body 1 (welding or interference fit), and the second control valve 3 and the mounting hole on the target engine cylinder block are pin / hole precision fits (such as clearance fits), which can achieve high-precision fit between the cooling nozzle and the cylinder block, making the position of the nozzle more accurate, thereby improving the accuracy of the cooling nozzle oil injection, and can effectively improve the assembly accuracy and minimize the clearance requirements between the cooling nozzle and other parts under the premise of simplifying the positioning design of the cooling nozzle. Among them, the precision fit of the hole usually refers to the close fit relationship between the hole and the shaft in mechanical design. This fit relationship is determined based on the relationship between the tolerance bands of the hole and the shaft. It can determine the tightness of the combination. The algebraic difference obtained by subtracting the size of the matching shaft from the size of the hole is called clearance when it is positive, and interference when it is negative. According to the positive and negative and size of this algebraic difference, the fit can be divided into three basic types: clearance fit, interference fit and transition fit.

[0051] A sealing ring 4 is provided at the connection between the second valve seat 8 and the oil passage of the target engine cylinder body, wherein the sealing ring 4 may be an elastic rubber ring structure, and the sealing ring 4 may achieve sealing with the cylinder body mounting hole, effectively reducing the leakage of the engine oil.

[0052] The second control valve 3 includes a second sealing cover plate 31 , a valve plate 32 , a temperature-pressure spring assembly and a second plunger 33 , wherein the second sealing cover plate 31 may be a blocking cover plate, and the temperature-pressure spring assembly includes a second pressure spring 34 and a temperature control spring 35 .

[0053] One end of the temperature and pressure spring assembly is connected to the second sealing cover plate 31, and the other end of the temperature and pressure spring assembly is connected to the second plunger 33. The second plunger 33 is used to generate a force on the second pressure spring 34 under the action of the oil pressure of the target engine cylinder block, so as to compress the second pressure spring 34 and drive the second plunger 33 to move in the compression direction of the second pressure spring 34 to control the communication state between the inner cavity of the second control valve 3 and the oil channel of the target engine cylinder block and the temperature control spring 35 is used to generate a compression amount under the action of the oil temperature of the target engine cylinder block, drive the second plunger 33 to move in the compression direction of the temperature control spring 35 to control the communication state between the inner cavity of the second control valve 3 and the oil channel of the target engine cylinder block. A temperature control spring 35 is used to automatically adjust the flow of the second cooling nozzle 6 to promptly respond to changes in the engine oil temperature. The reset spring can accurately reset the position of the valve plate 32 when the temperature returns to normal, and at the same time, push the second control valve 3 to open when the oil pressure increases. By adopting a combination of the temperature control spring 35 and the second pressure spring 34, the internal structure of the valve body can be greatly simplified, and the response speed of the valve body switch can be improved to a certain extent.

[0054] Alternatively, the temperature control spring 35 drives the second plunger 33 to move in the compression direction of the second pressure spring 34 to control the communication state between the inner cavity of the second control valve 3 and the oil passage of the target engine cylinder.

[0055] Alternatively, the temperature control spring 35 is used to generate compression under the action of the oil temperature of the target engine cylinder, driving the second plunger 33 to move in the compression direction of the temperature control spring 35 to control the communication state between the inner cavity of the second control valve 3 and the oil channel of the target engine cylinder.

[0056] The temperature control spring 35 is made of memory alloy material with an appropriate phase change temperature range and mechanical properties. When the temperature rises, the temperature control spring 35 expands due to heat, pushes the valve plate 32 upward, and the nozzle opens. The second pressure spring 34 is located on the opposite side of the temperature control spring 35 above the valve plate 32, and is used to push the temperature control spring 35 to reset and close the second cooling nozzle 6 when the cooling demand decreases. At the same time, when the oil pressure increases, the valve plate 32 will also move upward, compressing the second pressure spring 34. At this time, the second cooling nozzle 6 will also open, and the cooling medium flow rate is automatically adjusted by the temperature control spring 35 to achieve energy-saving and efficient cooling effect.

[0057] In some embodiments, when the oil pressure in the main oil channel increases, the first plunger 23 inside the corresponding first control valve 2 is forced to compress the first pressure spring 22 inside the first control valve 2 upward, so that the first control valve 2 is in an open state. At this time, the oil can be sprayed through the first cooling nozzle 5 to the corresponding position of the set piston cavity to cool the piston.

[0058] When the oil temperature is lower than the set value and the oil pressure in the main oil channel is lower than the set value, the elastic force of the temperature control spring 35 is weak and the oil pressure in the main oil channel is insufficient to compress the second pressure spring 34. At this time, the second control valve 3 is in a closed state.

[0059] When the engine oil temperature is higher than the set value, but the engine oil pressure in the main oil channel is lower than the set value, although the engine oil pressure in the main oil channel is not sufficient to compress the second pressure spring 34, the elastic force of the temperature control spring 35 increases and pushes the valve plate 32 upward. At this time, the second control valve 3 is in an open state, and the engine oil can be sprayed through the second cooling nozzle 6 to the corresponding position of the set piston cavity to cool the piston.

[0060] When the engine oil temperature is lower than the set value, but the engine oil pressure in the main oil channel is higher than the set value, although the elastic force of the temperature control spring 35 is weak, the engine oil pressure in the main oil channel will push the valve plate 32 to compress the second pressure spring 34. At this time, the second control valve 3 is in an open state, and the engine oil can be sprayed through the second cooling nozzle 6 to the corresponding position of the set piston cavity to cool the piston.

[0061] When the oil temperature is higher than the set value and the oil pressure in the main oil channel is higher than the set value, the elastic force of the temperature control spring 35 increases and pushes the valve plate 32 upward. At the same time, the oil pressure in the main oil channel pushes the valve plate 32 to compress the second pressure spring 34. At this time, the second control valve 3 is in an open state, and the oil can be sprayed to the corresponding position of the set piston cavity through the second cooling nozzle 6 to cool the piston.

[0062] Therefore, the first control valve 2 of the present invention can be opened or closed according to the set oil pressure control to cool the main heat load area of ​​the piston. When the load increases further, or the engine speed is low but the oil temperature is high, the second load area of ​​the piston needs to be supplemented with cooling. At this time, the second control valve 3 is opened to enable the two cooling nozzles to work in parallel. The cooling nozzle flow rate can be adjusted independently or collaboratively as needed to achieve a compact design of the cooling nozzle, which is suitable for engines of various cylinder diameters. The first control valve 2 and the second control valve 3 (in addition to the valve body function) have both positioning functions. Under the premise of simplifying the nozzle positioning design, the assembly accuracy can be effectively improved, the clearance requirement between the cooling nozzle and other parts is minimized to the greatest extent, the thermal load of the combustion system is effectively reduced, and the reliability of the vehicle is improved.

[0063] In summary, according to an embodiment of the present invention, the piston cooling nozzle includes: a valve body; a first valve seat, the first valve seat is arranged on the valve body; a second valve seat, the second valve seat is arranged on the valve body; a first control valve, the first control valve is arranged on the first valve seat, the inner cavity of the first control valve is selectively connected with the inner cavity of the first valve seat, and the inner cavity of the first valve seat is connected with the oil passage of the target engine cylinder; the first control valve is configured to perform an opening or closing action according to the oil pressure of the target engine cylinder; a second control valve, the second control valve is arranged on the second valve seat, the inner cavity of the second control valve is selectively connected with the inner cavity of the second valve seat, and the inner cavity of the second valve seat is connected with the oil passage of the target engine cylinder; the second control valve is configured to perform an opening or closing action according to the oil pressure and oil temperature of the target engine cylinder; a first cooling nozzle, the first cooling nozzle is arranged on the first valve seat and connected with the inner cavity of the first valve seat, and the first cooling nozzle is used to cool the first load zone of the target piston; a second cooling nozzle, the second cooling nozzle is arranged on the second valve seat and connected with the inner cavity of the second valve seat, and the second cooling nozzle is used to cool the second load zone of the target piston. Therefore, the cooling nozzle can cool more parts of the piston by spraying the oil beam sprayed by the cooling nozzle to different appropriate positions on the inner surface of the piston, so as to maximize the cooling effect and further improve the uniformity of piston cooling. Under the premise of simplifying the positioning design of the cooling nozzle, the assembly accuracy can be effectively improved and the clearance requirement between the cooling nozzle and other parts can be minimized. The compact design of the cooling nozzle can be realized, which is suitable for engines of various cylinder diameters. The cooling nozzle structure has a fast response and can provide more cooling flow when needed, and reduce the cooling flow when not needed, thereby improving the cooling efficiency. By improving the uniformity of piston cooling, the thermal stress of the piston is reduced, the service life of the piston and the engine is extended, the cost is reduced, the thermal load of the combustion system is reduced, and the reliability of the whole vehicle is improved.

[0064] refer to Figure 4 , which is a flow chart of a method for designing a piston cooling nozzle according to some embodiments of the present invention.

[0065] like Figure 4 As shown, the design method of the piston cooling nozzle according to the embodiment of the present invention may include the following steps:

[0066] S401, determining a first load zone and a second load zone for cooling a target piston, and determining a first spray angle of a first cooling nozzle according to a position of the first load zone, and determining a second spray angle of a second cooling nozzle according to a position of the second load zone.

[0067] Specifically, since the piston is one of the core components in the engine and needs to withstand the huge thermal and mechanical loads brought by high temperature, high pressure and high-speed reciprocating motion, it is crucial to effectively cool the piston to ensure that it can work normally under such conditions.

[0068] In order to determine the load zone for cooling the piston, it is necessary to first establish a finite element model of the piston and the cooling nozzle. The first step is model establishment: Use professional modeling software (such as SolidWorks, ProE, etc.) to create a three-dimensional model of the piston and the cooling nozzle. This model needs to accurately reflect the geometric shape and structural characteristics of the piston, including key parts such as the piston top surface, skirt, pin hole, and the position and shape of the cooling oil channel and nozzle. The second step is meshing: In the finite element analysis software (such as ANSYS, ABAQUS, etc.), mesh the piston model. The density and size of the mesh will affect the accuracy of the analysis and the calculation time, so it needs to be selected reasonably. For parts with large temperature gradients, such as the top of the piston and the ring groove area, local mesh encryption should be performed to improve the calculation accuracy. The third step is material property definition: According to the material of the piston (usually aluminum alloy), define its thermophysical properties in the finite element software, such as density, specific heat capacity, thermal conductivity, expansion coefficient, etc. The fourth step is boundary conditions and load application: Set the thermal boundary conditions of the piston during operation, including the surface temperature of the piston in contact with the gas, the heat transfer coefficient of the piston in contact with the coolant, etc. At the same time, according to the working conditions of the engine, the thermal load and mechanical load on the piston are applied. Step 5, temperature field calculation: perform finite element thermal analysis calculation to obtain the temperature field distribution of the piston. This will show the temperature changes of various parts of the piston under working conditions. Step 6, result analysis: analyze the calculation results and identify the areas with the highest temperature on the piston, which are usually the load areas that need cooling the most. For example, the top of the piston, the ring groove area and the vicinity of the pin hole are usually the areas with the largest heat load. Step 7, cooling strategy optimization: based on the results of the temperature field distribution, preliminarily determine the cooling positions corresponding to valve body 1 and valve body 2. This may involve adjusting the design of the cooling oil channel, changing the injection strategy or adding additional cooling measures. Step 8, verification and iteration: it may be necessary to verify the results of the finite element analysis through experimental testing (such as the hardness plug method), and iteratively optimize the model based on the experimental data to ensure the accuracy of the analysis results. Through the above steps, the first load area and the second load area for cooling the target piston can be systematically determined.

[0069] After obtaining the first load zone and the second load zone, the design requirements of the nozzle are determined according to the temperature field distribution of the piston, including the number, position and injection angle of the nozzle. The design of the nozzle needs to ensure that the coolant can cover the hot spot area of ​​the piston. The injection angle is determined according to the geometry of the piston and the position of the hot spot area. Ideally, the injection angle should allow the coolant to directly impact the hottest area of ​​the piston. The injection performance of the nozzle includes the jet velocity distribution, the jet boundary and the jet flow distribution, which will affect the cooling effect. For example, these parameters can be studied by establishing a theoretical model and using simulation software (such as FLUENT). The results of the theoretical model and simulation analysis need to be verified by experimental testing. An experimental device can be designed to test the cooling effect under different injection angles and optimize accordingly. The arrangement of the nozzle will also affect the cooling effect. For example, a regular quadrilateral arrangement may provide the best water uniformity, while a regular triangle or regular hexagonal arrangement may be more economical in some cases. In actual operation, it is necessary to consider the actual working conditions of the engine, such as oil pressure, nozzle flow coefficient, etc., which will affect the performance of the nozzle. The flow distribution and impact force of the nozzle are important factors affecting the cooling effect. It is necessary to ensure that the nozzle can provide sufficient impact force to cover the target area while maintaining uniform flow distribution.

[0070] Therefore, it is necessary to determine the first injection angle of the first cooling nozzle according to the position of the first load zone, and determine the second injection angle of the second cooling nozzle according to the position of the second load zone to ensure that the piston is effectively cooled, thereby improving the performance and reliability of the engine.

[0071] S402, determine the first rated flow of the first control valve and the second rated flow of the second control valve according to the maximum operating temperature of the target piston, determine the first caliber of the first cooling nozzle according to the first rated flow and the average linear velocity of the target piston, and determine the second caliber of the second cooling nozzle according to the second rated flow and the average linear velocity of the target piston.

[0072] Specifically, the first rated flow of the first control valve and the second rated flow of the second control valve are determined according to the maximum operating temperature of the target piston and the calculated flow, pressure difference, and flow coefficient. After the rated flow of the control valve is determined, the oil injection speed of the cooling nozzle is determined according to the average linear velocity of the target piston. It is necessary to determine the first caliber (first cross-sectional area) of the first cooling nozzle according to the first rated flow and the average linear velocity of the target piston, and determine the second caliber (second cross-sectional area) of the second cooling nozzle according to the second rated flow and the average linear velocity of the target piston. The caliber size of the nozzle directly affects the flow rate and flow of the coolant, thereby affecting the cooling effect. In order to determine the caliber of the nozzle, a flow calculator can be used to determine the flow rate at a given working pressure, or a spray coverage calculator can be used to determine the spray coverage range for a given spray height and angle. These tools can help select the correct nozzle size, spray angle, and number of nozzles to provide the desired cooling effect.

[0073] It should be explained that when selecting a nozzle, it is necessary to consider the nozzle's flow rate, spray angle, spray form, and the sprayed medium. For example, the nozzle's specifications may include the connection size, flow rate, angle, and spray form code, such as 3 / 4PZ105180QZ, which means the connection size is 3 / 4 inch, the flow rate is 10.5 liters / minute, the angle is 180 degrees, and the spray form is a solid cone nozzle.

[0074] S403: Determine a first opening pressure threshold of the first control valve and a second opening pressure threshold of the second control valve according to an oil pressure curve and an oil temperature curve of a target engine cylinder.

[0075] Specifically, according to the oil pressure curve of the target engine cylinder, the oil pressure changes under different working conditions can be determined, including the peak and valley values ​​of the oil pressure and the fluctuations under different speeds and loads. The oil pressure test usually includes monitoring oil pressure test, low-speed oil pressure test and high-speed oil pressure test to ensure that the oil pump can continuously provide sufficient pressure to ensure sufficient lubrication between the relative moving parts inside the engine. The oil temperature curve shows the temperature change of the oil under different working conditions. The viscosity of the oil is inversely proportional to the temperature. Therefore, the increase in oil temperature will lead to a decrease in viscosity, affecting its lubrication performance. The oil pressure needs to be adjusted through temperature compensation to ensure that the appropriate pressure can be maintained at different temperatures. The cooling demand of the piston is closely related to the thermal load of the engine. The high-load area usually requires more cooling to prevent the piston from overheating. In the high-load area, the control valve needs to be opened at a lower pressure to increase the flow of the coolant. The opening pressure threshold of the control valve should also consider the safety and reliability of the system. Too high an opening pressure may cause the system to fail to respond in time when cooling is required, while too low an opening pressure may cause the system to waste energy when it is unnecessary.

[0076] Through experimental testing and simulation analysis, the opening pressure threshold of the control valve can be determined more accurately. Therefore, the first opening pressure threshold of the first control valve and the second opening pressure threshold of the second control valve can be determined according to the oil pressure curve and oil temperature curve of the target engine cylinder.

[0077] S404, determining the first preload force and the first spring stiffness of the first pressure spring in the first control valve according to the first opening pressure threshold, determining the second preload force and the second spring stiffness of the second pressure spring in the second control valve according to the second opening pressure threshold, and determining the third preload force and the third spring stiffness of the temperature control spring in the second control valve according to the second opening pressure threshold.

[0078] Specifically, after obtaining the first opening pressure threshold and the second opening pressure threshold, the first preload force and the first spring stiffness of the first pressure spring in the first control valve can be determined according to the force corresponding to the first opening pressure threshold and the displacement of the valve core under the action of the force; the second preload force and the second spring stiffness of the second pressure spring in the second control valve can be determined according to the force corresponding to the second opening pressure threshold and the displacement of the valve core under the action of the force; the third preload force and the third spring stiffness of the temperature control spring in the second control valve can be determined according to the force corresponding to the second opening pressure threshold and the displacement of the valve core under the action of the force.

[0079] S405 , determining first design parameters of the first control valve and the first cooling nozzle according to the first injection angle, the first caliber, the first opening pressure threshold, the first preload force, and the first spring stiffness.

[0080] S406, determining second design parameters of the second control valve and the second cooling nozzle according to the second injection angle, the second caliber, the second opening pressure threshold, the second preload force, the second spring stiffness, the third preload force and the third spring stiffness.

[0081] Specifically, since the spray angle determines the coverage and spray direction of the coolant, it is critical to ensure that the piston is effectively cooled. The choice of spray angle should be based on the piston design and cooling needs to ensure that the coolant can reach the critical hot areas of the piston. The spray angle is usually set by adjusting the geometry of the nozzle. The diameter of the nozzle directly affects the flow rate and velocity of the coolant. The larger the diameter, the greater the flow rate, but it may also increase the pumping cost of the system. Selecting the right diameter can balance the cooling effect and system efficiency.

[0082] The opening pressure threshold of the control valve is a key parameter that determines when the valve starts to open to allow fluid flow. This value should be set according to the working conditions and safety requirements of the system. For example, in the design of the safety valve of the automobile fuel tank, the opening pressure is usually set at about 0.69MPa to ensure that the air pressure inside the fuel tank is within a controllable range. The preload of the pressure spring in the control valve determines the initial tension of the valve core when it is not subjected to external force. The size of the preload will affect the opening pressure and sealing performance of the control valve. The preload can be adjusted by adjusting the compression of the spring or selecting springs with different stiffness. The spring stiffness affects the response speed and flow characteristics of the control valve. A spring with higher stiffness can provide a faster response, but it may also cause the control valve to be too sensitive. The selection of spring stiffness should be based on the control requirements and working pressure of the system. Therefore, the first design parameters of the first control valve and the first cooling nozzle are determined according to the first injection angle, the first caliber, the first opening pressure threshold, the first preload, and the first spring stiffness. The second design parameters of the second control valve and the second cooling nozzle are determined according to the second injection angle, the second caliber, the second opening pressure threshold, the second preload force, the second spring stiffness, the third preload force and the third spring stiffness.

[0083] S407, designing a piston cooling nozzle according to the first design parameter and the second design parameter.

[0084] Specifically, after obtaining the first design parameter and the second design parameter, the piston cooling nozzle is designed according to the first design parameter and the second design parameter, and the pressure test, the target test, and the flow test are carried out to verify the accuracy of the design scheme. When the design scheme meets the design requirements, the various components of the piston cooling nozzle assembly are further designed in detail to obtain the piston cooling nozzle assembly system to complete the piston cooling nozzle design. When the design scheme does not meet the design requirements, it is necessary to re-simulate and analyze the entire system, re-determine the first load zone and the second load zone for cooling the target piston, and re-evaluate the structural parameters of the piston cooling nozzle assembly.

[0085] In some embodiments of the present invention, determining a first load zone and a second load zone for cooling a target piston includes: establishing a finite element model of a target piston and a piston cooling nozzle according to an operating condition of a target engine and structural parameters of a target engine cylinder; determining a temperature field distribution of the target piston according to the finite element model; and determining a first load zone and a second load zone of the target piston according to the temperature field distribution.

[0086] Specifically, the operating conditions of the target engine (such as idling, small load, medium load, large load / full load, acceleration) and the structural parameters of the target engine cylinder (such as cylinder material, cylinder structure, cylinder wall thickness, cylinder heat dissipation performance, cylinder stiffness, cylinder size, crankshaft hole, cylinder processing technology, cylinder positioning reference) are obtained, and the finite element model of the target piston and piston cooling nozzle is established according to the operating conditions of the target engine and the structural parameters of the target engine cylinder. The temperature field distribution of the target piston is determined according to the finite element model to determine the area where the target piston needs to be cooled, and the temperature changes of various parts of the piston under the working state are displayed. The areas with the highest temperature on the piston are identified. These areas are usually the load areas that need cooling the most. For example, the top of the piston, the ring groove area and the vicinity of the pin hole are usually the areas with the largest heat load. Then, the first load area and the second load area of ​​the target piston are determined according to the temperature field distribution.

[0087] As a specific example, Figure 5 As shown, the flowchart of the design method of the piston cooling nozzle of the present invention may include the following steps:

[0088] S501, determining a first load zone and a second load zone for cooling a target piston.

[0089] S502 , determining a first spray angle of a first cooling nozzle according to the position of a first load zone, and determining a second spray angle of a second cooling nozzle according to the position of a second load zone.

[0090] S503: Determine a first rated flow rate of the first control valve and a second rated flow rate of the second control valve according to the maximum operating temperature of the target piston.

[0091] S504, determining a first caliber of the first cooling nozzle according to the first rated flow rate and the average linear velocity of the target piston, and determining a second caliber of the second cooling nozzle according to the second rated flow rate and the average linear velocity of the target piston.

[0092] S505: Determine a first opening pressure threshold of the first control valve and a second opening pressure threshold of the second control valve according to an oil pressure curve and an oil temperature curve of a target engine cylinder.

[0093] S506, determine the first preload force and the first spring stiffness of the first pressure spring in the first control valve according to the first opening pressure threshold, determine the second preload force and the second spring stiffness of the second pressure spring in the second control valve according to the second opening pressure threshold, and determine the third preload force and the third spring stiffness of the temperature control spring in the second control valve according to the second opening pressure threshold.

[0094] S507 , determining first design parameters of the first control valve and the first cooling nozzle according to the first injection angle, the first caliber, the first opening pressure threshold, the first preload force, and the first spring stiffness.

[0095] S508, determining second design parameters of the second control valve and the second cooling nozzle according to the second injection angle, the second caliber, the second opening pressure threshold, the second preload force, the second spring stiffness, the third preload force and the third spring stiffness.

[0096] S509, designing a piston cooling nozzle according to the first design parameter and the second design parameter.

[0097] S510, judging whether the design scheme meets the design requirements. If yes, executing step S511; if no, returning to step S501.

[0098] S511, complete the design of piston cooling nozzle.

[0099] Therefore, the present invention comprehensively considers various boundary conditions such as piston temperature field, main oil channel pressure, oil temperature, piston running speed, etc., combines CAE simulation analysis method, sets parameters such as rated flow, opening pressure, nozzle angle, nozzle cross-sectional area, spring preload, spring stiffness, etc., and verifies the design accuracy through a series of test schemes. The design method of the piston cooling nozzle aims to meet the needs of piston cooling, while accurately controlling the injection direction and injection amount of the oil, which can effectively reduce the deviation that may be caused by the design based on experience, improve the design efficiency, and thus optimize the design selection and development process of the engine piston cooling nozzle.

[0100] In summary, according to the design method of the piston cooling nozzle of the embodiment of the present invention, the first load zone and the second load zone for cooling the target piston are determined, and the first injection angle of the first cooling nozzle is determined according to the position of the first load zone, and the second injection angle of the second cooling nozzle is determined according to the position of the second load zone; the first rated flow of the first control valve and the second rated flow of the second control valve are determined according to the maximum operating temperature of the target piston, the first caliber of the first cooling nozzle is determined according to the first rated flow and the average linear velocity of the target piston, and the second caliber of the second cooling nozzle is determined according to the second rated flow and the average linear velocity of the target piston; the first opening pressure threshold of the first control valve and the second opening pressure threshold of the second control valve are determined according to the oil pressure curve and the oil temperature curve of the target engine cylinder; Determine the first preload and the first spring stiffness of the first pressure spring in the first control valve according to the first opening pressure threshold, determine the second preload and the second spring stiffness of the second pressure spring in the second control valve according to the second opening pressure threshold, and determine the third preload and the third spring stiffness of the temperature control spring in the second control valve according to the second opening pressure threshold; determine the first design parameters of the first control valve and the first cooling nozzle according to the first injection angle, the first caliber, the first opening pressure threshold, the first preload and the first spring stiffness; determine the second design parameters of the second control valve and the second cooling nozzle according to the second injection angle, the second caliber, the second opening pressure threshold, the second preload, the second spring stiffness, the third preload and the third spring stiffness; design the piston cooling nozzle according to the first design parameters and the second design parameters. Therefore, this method determines whether the piston cooling nozzle is working in combination with the actual operating conditions of the whole machine, and accurately controls the injection direction and injection amount of the piston cooling nozzle when the piston cooling nozzle is working. At the same time, it reduces the demand for the oil pump capacity from the cooling system level as much as possible, reduces energy waste, and can further improve fuel economy, further improve the thermal efficiency of the whole machine, effectively reduce the deviation that may be caused by experience-based design, and improve design efficiency.

[0101] It should be noted that some embodiments of the present invention are described above. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in an order different from that in the above embodiments and still achieve the desired results. In addition, the processes depicted in the accompanying drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0102] In addition, although the operations of the method of the present invention are described in a specific order in the accompanying drawings, this does not require or imply that the operations must be performed in this specific order, or that all the operations shown must be performed to achieve the desired results. On the contrary, the steps depicted in the flow chart can be performed in a different order. Additionally or alternatively, some steps can be omitted, multiple steps can be combined into one step, and / or one step can be decomposed into multiple steps.

[0103] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present invention should be understood by people with ordinary skills in the field to which the present invention belongs. The "first", "second" and similar words used in the embodiments of the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0104] Although the spirit and principle of the present invention have been described with reference to several specific embodiments, it should be understood that the present invention is not limited to the disclosed specific embodiments, and the division of various aspects does not mean that the features in these aspects cannot be combined to benefit, and this division is only for the convenience of expression. The present invention is intended to cover various modifications and equivalent arrangements included in the spirit and scope of the attached claims. The scope of the attached claims conforms to the broadest interpretation, thereby including all such modifications and equivalent structures and functions.

Claims

1. A piston cooling nozzle, characterized in that: include: Valve body (1); a first valve seat (7), wherein the first valve seat (7) is arranged on the valve body (1); a second valve seat (8), the second valve seat (8) being arranged on the valve body (1); a first control valve (2), the first control valve (2) being arranged on the first valve seat (7), the inner cavity of the first control valve (2) being selectively connected to the inner cavity of the first valve seat (7), the inner cavity of the first valve seat (7) being connected to the oil passage of the target engine cylinder; the first control valve (2) being configured to perform an opening or closing action according to the oil pressure of the target engine cylinder; a second control valve (3), the second control valve (3) being arranged on the second valve seat (8), the inner cavity of the second control valve (3) being selectively connected to the inner cavity of the second valve seat (8), the inner cavity of the second valve seat (8) being connected to the oil passage of the target engine cylinder; the second control valve (3) being configured to perform an opening or closing action according to the oil pressure and oil temperature of the target engine cylinder; a first cooling nozzle (5), the first cooling nozzle (5) being arranged on the first valve seat (7) and communicating with the inner cavity of the first valve seat (7), the first cooling nozzle (5) being used for cooling a first load zone of the target piston; A second cooling nozzle (6), the second cooling nozzle (6) is arranged on the second valve seat (8) and is in communication with the inner cavity of the second valve seat (8), the second cooling nozzle (6) being used for cooling a second load zone of the target piston.

2. The piston cooling nozzle according to claim 1, characterized in that The valve body (1) is provided with a first limiting hole, and the first valve seat (7) passes through the first limiting hole and is fixedly arranged on the valve body (1).

3. The piston cooling nozzle according to claim 1, characterized in that: The valve body (1) is provided with a second limiting hole, and the second valve seat (8) passes through the second limiting hole and is fixedly arranged on the valve body (1).

4. The piston cooling nozzle according to claim 2, characterized in that: The inner contour of the first valve seat (7) is provided with an internal thread structure, and the outer contour of the first control valve (2) is provided with an external thread structure. The first control valve (2) passes through the first valve seat (7) and is fixed on the first valve seat (7) by means of the external thread structure cooperating with the internal thread structure of the first valve seat (7); the first control valve (2) cooperates with a first preset through hole of a target engine cylinder body through the internal thread structure, so that the inner cavity of the first control valve (2) is connected with the oil passage of the target engine cylinder body through the first preset through hole.

5. The piston cooling nozzle according to claim 3, characterized in that: The bottom of the second control valve (3) cooperates with the second preset through hole of the target engine cylinder body, so that the inner cavity of the second control valve (3) is connected with the oil passage of the target engine cylinder body through the second preset through hole.

6. The piston cooling nozzle according to claim 5, characterized in that A sealing ring (4) is provided at the connection between the second valve seat (8) and the oil passage of the target engine cylinder body.

7. The piston cooling nozzle according to claim 4, characterized in that The first control valve (2) comprises a first sealing cover plate (21), a first pressure spring (22) and a first plunger (23); One end of the first pressure spring (22) is connected to the first sealing cover plate (21), and the other end of the first pressure spring (22) is connected to the first plunger (23); The first plunger (23) is used to generate a force on the first pressure spring (22) under the action of the oil pressure of the target engine cylinder body, so as to compress the first pressure spring (22) and drive the first plunger (23) to move in the compression direction of the first pressure spring (22) to control the communication state between the inner cavity of the first control valve (2) and the oil channel of the target engine cylinder body.

8. The piston cooling nozzle according to claim 5, characterized in that The second control valve (3) comprises a second sealing cover plate (31), a temperature-pressure spring assembly and a second plunger (33); the temperature-pressure spring assembly comprises a second pressure spring (34) and a temperature control spring (35); One end of the warm-pressure spring assembly is connected to the second sealing cover plate (31), and the other end of the warm-pressure spring assembly is connected to the second plunger (33); The second plunger (33) is used to generate a force on the second pressure spring (34) under the action of the oil pressure of the target engine cylinder body, so as to compress the second pressure spring (34) and drive the second plunger (33) to move in the compression direction of the second pressure spring (34) to control the communication state between the inner cavity of the second control valve (3) and the oil channel of the target engine cylinder body; or / and, the temperature control spring (35) is used to generate a compression amount under the action of the oil temperature of the target engine cylinder body, drive the second plunger (33) to move in the compression direction of the temperature control spring (35) to control the communication state between the inner cavity of the second control valve (3) and the oil channel of the target engine cylinder body.

9. A method for designing a piston cooling nozzle, characterized in that: The piston cooling nozzle as claimed in any one of claims 1 to 8 comprises: Determine a first load zone and a second load zone for cooling a target piston, and determine a first spray angle of a first cooling nozzle according to a position of the first load zone, and determine a second spray angle of a second cooling nozzle according to a position of the second load zone; Determine a first rated flow rate of the first control valve and a second rated flow rate of the second control valve according to the maximum operating temperature of the target piston, determine a first caliber of the first cooling nozzle according to the first rated flow rate and the average linear velocity of the target piston, and determine a second caliber of the second cooling nozzle according to the second rated flow rate and the average linear velocity of the target piston; Determining a first opening pressure threshold of the first control valve and a second opening pressure threshold of the second control valve according to an oil pressure curve and an oil temperature curve of the target engine cylinder; Determine a first preload force and a first spring stiffness of a first pressure spring in the first control valve according to the first opening pressure threshold, determine a second preload force and a second spring stiffness of a second pressure spring in the second control valve according to the second opening pressure threshold, and determine a third preload force and a third spring stiffness of a temperature control spring in the second control valve according to the second opening pressure threshold; determining first design parameters of the first control valve and the first cooling nozzle according to the first injection angle, the first caliber, the first opening pressure threshold, the first preload force, and the first spring stiffness; Determining second design parameters of the second control valve and the second cooling nozzle according to the second injection angle, the second caliber, the second opening pressure threshold, the second preload force, the second spring stiffness, the third preload force, and the third spring stiffness; The piston cooling nozzle is designed according to the first design parameter and the second design parameter.

10. The method for designing a piston cooling nozzle according to claim 9, characterized in that: The step of determining a first load zone and a second load zone for cooling a target piston comprises: Establishing a finite element model of the target piston and the piston cooling nozzle according to the operating conditions of the target engine and the structural parameters of the target engine cylinder; Determining the temperature field distribution of the target piston according to the finite element model; A first load zone and a second load zone of the target piston are determined according to the temperature field distribution.

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