Internal combustion engine lubrication system

Abstract

An internal combustion engine lubrication system includes an engine block, an engine block front end cover, an oil pan, a lubricating oil pump, a lubricating oil cooler and a lubricating oil filter. A main pressure regulating valve is provided on the engine block at the oil outlet of the lubricating oil pump. The plunger cavity of the main pressure regulating valve is provided in the engine block. One end of the plunger cavity is connected to the oil outlet passage of the lubricating oil pump, and the other end extends toward the outside of the engine block and forms a plunger cavity opening on the surface of the engine block. A plunger and a plunger spring are provided in the plunger cavity. The plunger spring is provided near the plunger cavity opening. A main pressure regulating valve cover is provided at the plunger cavity opening. The plunger cavity is connected to the oil inlet passage of the lubricating oil pump through an oil drain passage. While ensuring the lubricating oil pressure required by the lubricating oil system, the lubricating oil flow rate flowing through the lubricating oil cooler and the lubricating oil filter is reduced, so that the design of the lubricating oil cooler and the lubricating oil filter can be more lightweight.

Description

Technical Field

[0001] The present invention relates to the technical field of internal combustion engines, and in particular to a lubrication system for an internal combustion engine. Background Art

[0002] The lubrication system of an internal combustion engine not only lubricates the moving parts of the internal combustion engine, but also cools and cleans some of the internal parts of the internal combustion engine. In order to ensure the stable and reliable operation of the internal combustion engine, the basic requirement for the design of the engine lubrication system is to be able to continuously and stably provide clean lubricating oil of a certain pressure and temperature to the predetermined parts of the internal combustion engine under any circumstances. In addition, as the market's requirements for the economy and lightweight of internal combustion engines are getting higher and higher, this also puts higher requirements on the design of the internal combustion engine lubrication system. In other words, it is necessary to meet the requirements of the internal combustion engine lubrication system to be more energy-saving and compact through the reasonable design of the structure and layout of the internal combustion engine lubrication system.

[0003] The lubrication system of an internal combustion engine generally includes an oil pan, an oil suction pipe assembly, a lubricating oil pump, a lubricating oil cooler, a lubricating oil filter, a number of lubricating oil channels, etc. In order to meet the lubricating oil pressure requirements of the internal combustion engine at all speeds, the oil supply capacity of the lubricating oil pump is designed to meet the worst speed of the internal combustion engine, which results in the lubricating oil pump often supplying excess oil at high speeds of the internal combustion engine.

[0004] Taking the above into consideration, in order to maintain a continuous and stable lubricating oil pressure in the lubricating oil channel, a pressure regulating valve is generally installed in the lubrication system of the internal combustion engine to discharge and recover excess lubricating oil, so as to avoid premature damage to parts such as the lubricating oil pump and lubricating oil filter due to excessive lubricating oil pressure, as well as increased resistance loss of moving parts.

[0005] In the prior art, due to the limitation of the pressure regulating valve and the cylinder structure, the pressure regulating valve is generally arranged on the main lubricating oil passage in the cylinder of the internal combustion engine and placed in the inner cavity of the cylinder of the internal combustion engine. The excess lubricating oil flowing out of the pressure regulating valve is directly discharged into the oil pan for recovery. Since the discharged lubricating oil has been cooled by the lubricating oil cooler and filtered by the lubricating oil filter arranged before the pressure regulating valve, this causes unnecessary capacity consumption of the lubricating oil cooler and the lubricating oil filter. At the same time, because the lubricating oil to be recovered later needs to be cooled and filtered, the volume of the lubricating oil cooler, the lubricating oil filter and the entire cooling system (including the water pump, water pipe, etc.) needs to be larger, which is not conducive to the realization of the design goals of lightweight and compact internal combustion engines. In addition, it also reduces the service life of the lubricating oil cooler and the lubricating oil filter. In addition, the excess lubricating oil in the main lubricating oil passage is directly discharged back into the oil pan, which also causes a large amount of capacity waste of the lubricating oil pump and reduces the overall mechanical efficiency of the internal combustion engine. Furthermore, in the prior art, the pressure regulating valve is arranged in the inner cavity of the cylinder of the internal combustion engine, which also makes the maintenance of the pressure regulating valve very inconvenient.

[0006] In addition, in the prior art lubrication system of an internal combustion engine, a plurality of lubricating oil channels that penetrate the cylinder body of the internal combustion engine are usually arranged in the cylinder body of the internal combustion engine, and then connecting holes are machined between the plurality of lubricating oil channels to achieve mutual communication (for example, a main lubricating oil channel and a secondary lubricating oil channel are arranged, and the two lubricating oil channels are respectively arranged on both sides of the cylinder body of the internal combustion engine, and the main and secondary lubricating oil channels are connected by machining a long through hole in the cylinder body of the internal combustion engine). Since the connecting holes are usually thin and long, not only is the processing cost high, but it also reduces the structural strength of the internal combustion engine. Especially under the current trend of compact design of internal combustion engines, the space for the location of the connecting holes is very limited, and the difficulty of processing the connecting holes is further increased.

[0007] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention and should not be regarded as an acknowledgment or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art. Summary of the invention

[0008] In order to solve the above technical problems, the present invention provides a lubrication system for an internal combustion engine.

[0009] The technical solution adopted by the present invention to solve the above technical problems is: an internal combustion engine lubrication system, including an engine cylinder, a front cover, an oil pan, a lubricating oil pump, a lubricating oil cooler and a lubricating oil filter, wherein the lubricating oil pump is arranged on the engine cylinder, and is used to suck and pressurize the lubricating oil from the oil pan to realize the flow of the lubricating oil in the lubricating oil channel, the lubricating oil cooler is used to cool the lubricating oil, and the lubricating oil filter is used to filter the lubricating oil, the lubricating oil channel includes a lubricating oil pump inlet channel and a lubricating oil pump outlet channel arranged in the engine cylinder, and the lubricating oil pump inlet channel is provided. The cam is connected to the oil pump via an oil inlet, and an oil outlet of the oil pump is connected to the oil pump via an oil outlet of the oil pump. A main pressure regulating valve is provided at the oil outlet of the oil pump. A plunger cavity of the main pressure regulating valve is provided in the engine cylinder body. One end of the plunger cavity is connected to the oil outlet of the oil pump, and the other end extends toward the outside of the engine cylinder body and forms a plunger cavity opening on the surface of the engine cylinder body. A plunger and a plunger spring are provided in the plunger cavity. The plunger spring is provided close to the plunger cavity opening. A main pressure regulating valve cover is provided at the plunger cavity opening. The plunger cavity is connected to the oil inlet of the oil pump via an oil drain passage.

[0010] Furthermore, the main pressure regulating valve cover is threadedly installed at the plunger cavity opening, and a hollow cavity is provided in the part where the main pressure regulating valve cover is screwed into the plunger opening, and an adjustment pad is provided in the hollow cavity for supporting the plunger spring and adjusting the pre-pressure of the main pressure regulating valve.

[0011] Furthermore, the plunger includes a large diameter section and a small diameter section, the large diameter section is provided with a blind hole opening toward one side of the oil outlet channel of the lubricating oil pump, the opening end of the blind hole of the large diameter section is supported at the bottom of the plunger cavity, and a pressure regulating valve oil inlet channel connected to the oil outlet channel of the lubricating oil pump is provided at the bottom of the plunger cavity, the plunger spring is sleeved on the outside of the small diameter section of the plunger, one end of the plunger spring is supported on the end of the large diameter section, and the other end extends into the hollow cavity of the valve cover of the main pressure regulating valve and rests on the adjusting pad.

[0012] Furthermore, a plurality of oil drain holes are provided on the hole wall of the blind hole along the circumference of the blind hole, and the oil drain holes can be connected with the oil drain passage when the plunger is subjected to the oil inlet pressure to depress the plunger spring.

[0013] Furthermore, one end of the large diameter section provided with the blind hole is a tooth-shaped structure, and the tip of the tooth abuts against the bottom of the plunger cavity.

[0014] Furthermore, the portion of the plunger cavity where the plunger spring is installed is a plunger spring cavity, and a through hole is provided between the plunger spring cavity and the crankcase.

[0015] Furthermore, the oil drain passage comprises a parallel section of the lubricating oil pump oil inlet passage communicating with the plunger cavity and a vertical section of the lubricating oil pump oil inlet passage connected to the oil inlet of the lubricating oil pump.

[0016] Furthermore, a backup pressure regulating valve is provided on the passage from the oil outlet of the lubricating oil pump to the lubricating oil cooler and the lubricating oil filter, and the opening pressure of the backup pressure regulating valve is greater than the opening pressure of the main pressure regulating valve.

[0017] Furthermore, a cylinder groove is precast on the front end face of the engine cylinder block, and an end cover groove with the same shape as the cylinder groove is precast on the front end cover of the engine cylinder block. The cylinder groove and the end cover groove are combined to form a connecting oil channel for the circulation of lubricating oil.

[0018] Furthermore, the connecting oil passages include main connecting oil passages for connecting a plurality of main lubricating oil passages in the engine cylinder, and the paths of the main connecting oil passages may be wavy or may be set to other different curve shapes as required.

[0019] Beneficial effects:

[0020] According to the present invention, by improving the structure of the main pressure regulating valve and arranging it before the lubricating oil in the lubricating system flows through the lubricating oil cooler and the lubricating oil filter, the excess lubricating oil can flow back before flowing through the lubricating oil cooler and the lubricating oil filter, thereby ensuring the lubricating oil pressure required by the lubricating oil system while reducing the lubricating oil flow through the lubricating oil cooler and the lubricating oil filter, making the design of the lubricating oil cooler and the lubricating oil filter lighter and reducing the resistance loss of the lubricating path.

[0021] The lubrication system of the present invention can realize adjustable pressure of the lubricating oil system during its life cycle; at the same time, the lubricating oil discharged through the main pressure regulating valve directly enters the oil inlet passage of the lubricating oil pump instead of flowing into the oil pan, thereby reducing the oil pumping energy consumption of the lubricating oil pump and improving the economy of the engine. At the same time, the maximum flow rate of the lubricating oil in the oil inlet passage of the lubricating oil pump can be reduced, thereby avoiding the use of a larger oil inlet passage diameter of the lubricating oil pump, making the layout of the oil inlet passage of the lubricating oil pump easier and improving the strength of the engine cylinder body.

[0022] In addition, by providing a connecting oil channel for the lubricating oil by means of pre-cast grooves on the front end surface of the engine cylinder block and the front end cover of the engine cylinder block, the number of oil holes processed inside the engine cylinder block can be reduced, thereby reducing production costs. Furthermore, by providing an oil storage chamber in the connecting oil channel, a larger oil storage space can be achieved, thereby accelerating the establishment of lubricating oil pressure at the end of the lubricating oil system when the engine is started, thereby avoiding wear of components at the end of the lubricating oil circuit. On the other hand, the design of this oil storage chamber can also reduce the weight of the engine and meet the design requirements of light weight of the engine.

[0023] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0025] Figure 2 for Figure 1 A rotating view of the engine block (in this figure, the lubricating oil pump and the oil passages arranged in the engine block are abstractly separated from the engine block itself);

[0026] Figure 3 for Figure 1 Schematic diagram of the horizontal cross-section structure of the pressure regulating valve represented by serial number 4;

[0027] Figure 4 for Figure 1 A schematic diagram of the vertical cross-sectional structure of a pressure regulating valve represented by serial number 4;

[0028] Figure 5 for Figure 1 A horizontal cross-sectional schematic diagram of a connection passage between a lubricating oil cooler and a lubricating oil filter integrated module (referred to as a cold filter module) represented by sequence number 6 and an engine cylinder block represented by sequence number 1 and a front end cover of the engine cylinder block represented by sequence number 2;

[0029] Figure 6 for Figure 1 A schematic diagram of the front end structure of the engine cylinder block represented by serial number 1;

[0030] Figure 7 for Figure 1 A schematic diagram of the matching end surface of the engine cylinder block represented by the number 2 and the engine cylinder block represented by the number 1;

[0031] Figure 8 for Figure 1 Schematic diagram of the cross-sectional structure of the spare pressure regulating valve represented by serial number 5. DETAILED DESCRIPTION

[0032] like Figure 1 and Figure 2 As shown, a lubrication system of an internal combustion engine includes an engine block 1, an oil pan (not shown in the figure), a front end cover 2 of the engine block, a lubricating oil pump 3, a main pressure regulating valve 4, a standby pressure regulating valve 5, a lubricating oil cooler and a lubricating oil filter integrated module (referred to as a cold filter module) 6. The lubricating oil pump 3 is arranged on the engine block 1, and is used to suck and pressurize the lubricating oil from the oil pan to realize the flow of the lubricating oil in the lubricating oil channel. The lubricating oil cooler is used to cool the lubricating oil, and the lubricating oil filter is used to filter the lubricating oil.

[0033] The lubricating oil passage includes a lubricating oil pump inlet passage 101 and a lubricating oil pump outlet passage 102 arranged in the engine cylinder body. The lubricating oil pump inlet passage 101 is connected to the lubricating oil pump 3 through the lubricating oil pump inlet port 31, and the lubricating oil pump outlet passage 102 is connected to the lubricating oil pump 3 through the lubricating oil pump outlet port 32. A main pressure regulating valve 4 is arranged at the lubricating oil pump outlet port 32.

[0034] Specifically, the lubricating oil pump inlet passage 101 and the lubricating oil pump outlet passage 102 are arranged near the end surface of the engine cylinder block 1. Figure 1-Figure 4 As shown, the two are coaxially arranged vertical oil passages. The lubricating oil pump inlet passage 101 has a slightly larger aperture than the lubricating oil pump outlet passage 102. Its bottom is connected to the bottom surface of the engine cylinder block 1 and is used to connect the oil suction pipe. An internal thread is set at the bottom of the lubricating oil pump outlet passage 102, and a screw plug 8 with an external thread is installed. The lubricating oil pump inlet passage 101 and the lubricating oil pump outlet passage 102 are separated by the screw plug 8, wherein the top of the lubricating oil pump inlet passage 101 is connected to the lubricating oil pump oil inlet port 31, and the bottom of the lubricating oil pump outlet passage 102 is connected to the lubricating oil pump oil outlet port 32. With this structural form, the lubricating oil pump inlet passage 101 and the lubricating oil pump outlet passage 102 can be actually processed as one hole, and then the lubricating oil pump inlet passage 101 is expanded. The two oil passages are separated from each other by a screw plug 8 at the bottom of the lubricating oil pump outlet passage 102, which facilitates processing and improves space utilization efficiency, making the structure of the engine cylinder block more compact.

[0035] The plunger cavity 13 of the main pressure regulating valve 4 is inclined at a certain angle to the side of the engine cylinder body and is arranged in the engine cylinder body 1. One end of the plunger cavity 13 is connected with the lubricating oil pump oil outlet passage 102 through the pressure regulating valve oil inlet passage 111 arranged coaxially therewith, and the end of the pressure regulating valve oil inlet passage 111 connected with the lubricating oil pump oil outlet passage 102 is arranged near the lubricating oil pump oil outlet port 32; the other end of the plunger cavity 13 extends toward the outside of the engine cylinder body 1 and forms a plunger cavity opening on the surface of the engine cylinder body 1, a plunger 41 and a plunger spring 42 are arranged in the plunger cavity, the plunger spring 42 is arranged close to the plunger cavity opening, and a main pressure regulating valve valve cover 44 is provided at the plunger cavity opening, and the plunger cavity 13 is connected with the lubricating oil pump oil inlet passage 101 near the lubricating oil pump oil inlet port 31 through the oil drain passage.

[0036] Specifically, the main pressure regulating valve cover 44 is installed by matching the external thread with the internal thread at the opening of the plunger cavity, and a sealing gasket 45 is arranged between the main pressure regulating valve cover 44 and the engine cylinder 1 to achieve the sealing of the plunger spring cavity 14 (the part of the plunger cavity 13 where the plunger spring 42 is installed is the plunger spring cavity 14). A hollow cavity is provided in the part where the main pressure regulating valve cover 44 is screwed into the opening of the plunger cavity, and an adjusting gasket 43 is arranged in the hollow cavity for supporting the plunger spring 42 and adjusting the pre-pressure of the main pressure regulating valve 4. The pre-pressure of the plunger spring 42 can be adjusted by replacing the adjusting gasket 43 with different thicknesses, thereby realizing the adjustment and control of the opening pressure of the main pressure regulating valve 4. The main pressure regulating valve cover 44 with a hollow cavity structure can accommodate a longer plunger spring 42 within a limited plunger spring cavity length, thereby increasing the axial stroke of the plunger 41, making the adjustment function of the main pressure regulating valve 4 more sensitive and stable, and also making the engine cylinder 1 more compact.

[0037] In this preferred embodiment, the plunger 41 includes a large diameter section and a small diameter section 414. The large diameter section is provided with a blind hole 411. The opening of the blind hole 411 faces the side of the pressure regulating valve oil inlet 111 (also the side of the lubricating oil pump oil outlet), and the blind hole opening end of the large diameter section is supported at the bottom of the plunger cavity. The diameter of the plunger cavity 13 is slightly larger than the diameter of the pressure regulating valve oil inlet 111, so that an annular step surface (i.e., the bottom of the plunger cavity) is formed at the junction of the plunger cavity 13 and the pressure regulating valve oil inlet 111, which plays a role in limiting the plunger 41. In this preferred implementation, one end 413 of the large diameter section provided with the blind hole is a tooth-shaped structure, so the tip of the tooth abuts against the annular step surface. The design of the tooth-shaped structure reduces the contact area between the plunger 41 and the annular step surface, while increasing the contact area between the plunger 41 and the lubricating oil, making the main pressure regulating valve 4 more sensitive. At the same time, it avoids the situation in which the plunger 41 is abnormally vibrated due to the sudden and significant increase in the area of ​​the end face of the plunger 41 affected by the lubricating oil force when the plunger 41 is displaced and leaves the annular step surface due to the lubricating oil pressure from the pressure regulating valve oil inlet channel 111 (the increased area comes from the contact area between the plunger 41 and the annular step surface when the plunger 41 abuts against the annular step surface). This makes the opening of the main pressure regulating valve 4 smoother and more stable, while minimizing the sticking of the plunger 41.

[0038] The plunger spring 42 is sleeved on the outside of the plunger small diameter section, one end of the plunger spring 42 is supported at the end of the large diameter section, and the other end extends into the hollow cavity of the main pressure regulating valve cover 44 and abuts against the adjusting gasket 43. The plunger small diameter section can also be made into a hollow structure to reduce weight.

[0039] A plurality of oil drain holes 412 are provided on the blind hole wall of the plunger 41 along the circumference of the blind hole. The oil drain holes 412 are connected with the oil drain passage when the plunger 41 is subjected to the oil inlet pressure to depress the plunger spring 42, so as to drain the excess lubricating oil back to the oil pan.

[0040] In this preferred embodiment, the oil drain passage includes a lubricating oil pump oil inlet passage parallel section 112 connected to the plunger chamber 13 and a lubricating oil pump oil inlet passage vertical section 113 connected to the lubricating oil pump oil inlet port 31. Figure 3 and Figure 4 As shown, the upper end of the parallel section 112 of the lubricating oil pump inlet passage is connected to the plunger cavity 13, and a screw plug is installed at the lower end to achieve sealing. One end of the vertical section 113 of the lubricating oil pump inlet passage is connected to the parallel section 112 of the lubricating oil pump inlet passage, and the other end is connected to the lubricating oil pump inlet passage 101 and is located near the lubricating oil pump inlet port 31. The parallel section 112 of the lubricating oil pump inlet passage is formed by drilling a long hole inward from the bottom surface of the engine cylinder block, the long hole is connected to the plunger cavity 13, and then taking a section of the long hole close to the plunger cavity, and setting a screw plug for sealing.

[0041] The main pressure regulating valve 4 adopts the above-mentioned bypass circuit, which can directly deliver the discharged excess lubricating oil to the lubricating oil pump inlet 31 instead of discharging it back to the oil pan, which greatly reduces the pumping capacity loss of the lubricating oil pump 3, improves the working efficiency of the lubricating oil pump 3, and is beneficial to reducing the volume of the lubricating oil pump 3. At the same time, since the discharged excess lubricating oil is directly delivered to the lubricating oil pump inlet 31, the maximum lubricating oil flow rate sucked from the oil pan and flowing through the lubricating oil pump inlet passage 101 will be reduced accordingly, so that the diameter of the lubricating oil pump inlet passage 101 can be reduced, making it easier to arrange. A smaller diameter of the lubricating oil pump inlet passage 101 can reduce the space occupied by the engine cylinder block 1, thereby also improving the strength of the engine cylinder block 1.

[0042] like Figure 3 As shown, in this preferred embodiment, a through hole 15 is further provided between the plunger spring chamber 14 and the crankcase. One end of the through hole 15 opens to the engine cylinder block 1, and the other end is connected to the crankcase. An internal thread is provided at the opening of the through hole 15 located on the outer side of the engine cylinder block 1, and a screw plug 46 is installed in cooperation with the internal thread to achieve sealing of the lubricating oil. Such a structural design, on the one hand, enables the plunger spring chamber 14 to have a breathing function, and on the other hand, allows the lubricating oil that penetrates into the plunger spring chamber 14 through the tiny gap between the plunger 41 and the plunger chamber 13 to be discharged to the oil pan through the through hole 15, thereby avoiding the plunger spring chamber 14 from breathing difficulties, and also avoiding the failure of the main pressure regulating valve 4 caused by the plunger spring chamber 14 being filled with lubricating oil.

[0043] The present invention arranges the main pressure regulating valve 4 at a position before the lubricating oil flows through the cold filter module 6, thereby preventing excess lubricating oil from entering the cold filter module 6, reducing the burden on the lubricating oil cooler, the lubricating oil filter and the cooling system, and facilitating the use of a smaller cold filter module, thereby making the engine layout more compact.

[0044] In order to prevent the main pressure regulating valve 4 from having insufficient regulating capacity or failure under extremely harsh environmental conditions (such as extremely cold conditions), the lubricating oil pressure entering the lubrication system is too high, in this embodiment, Figure 1 , Figure 2 and Figure 8 As shown, a backup pressure regulating valve 5 is provided between the oil outlet 32 ​​of the lubricating oil pump and the oil inlet 61 of the cold filter module. The opening pressure of the backup pressure regulating valve 5 is greater than the opening pressure of the main pressure regulating valve 4. The backup pressure regulating valve 5 can adopt the existing technology. Figure 8 The structure shown is installed in the spare pressure regulating valve mounting hole 24 provided in the front end cover 2 of the engine cylinder block, the spare pressure regulating valve bonnet 53 is connected to the spare pressure regulating valve mounting hole 24 by threads, and accordingly, an external thread is provided on the spare pressure regulating valve bonnet 53, an internal thread is provided inside the spare pressure regulating valve mounting hole 24, and a sealing gasket 54 is provided between the spare pressure regulating valve bonnet 53 and the front end cover 2 of the engine cylinder block to achieve sealing. The spare pressure regulating valve spring 52 is located between the steel ball 51 and the spare pressure regulating valve bonnet 53, one end of the spare pressure regulating valve spring 52 is in direct contact with the inner bottom surface of the spare pressure regulating valve bonnet 53, and the other end is in direct contact with the steel ball 51, and the spare pressure regulating valve spring 52 transmits the axial force applied by the spare pressure regulating valve bonnet 53 to the steel ball 51, thereby pressing the steel ball 51 against the corresponding connecting hole 23 connected to the connecting oil passage 103. An oil drain hole 25 is provided at the bottom of the standby pressure regulating valve mounting hole 24, one end of the oil drain hole 25 is connected to the standby pressure regulating valve mounting hole 24, and the other end is connected to the crankcase cavity. When the lubricating oil pressure flowing through the standby pressure regulating valve 5 reaches and exceeds the opening pressure of the standby pressure regulating valve 5, the lubricating oil pushes the steel ball 51 open and enters the standby pressure regulating valve mounting hole 24, and then is discharged through the oil drain hole 25 and flows back to the oil pan by gravity. Since the standby pressure regulating valve 5 is not frequently used, such a design structure is simple, low cost, and easy to maintain.

[0045] The standby pressure regulating valve 5 is set to drain oil to reduce the system pressure, thereby playing a dual protection role for the engine lubrication system together with the main pressure regulating valve 4.

[0046] In order to further optimize the engine lubrication system, in this preferred embodiment, a cylinder groove is precast on the front end face of the engine cylinder block 1, and an end cover groove consistent with the shape of the cylinder groove is precast on the front end cover 2 of the engine cylinder block. The cylinder groove and the end cover groove are combined to form a connecting oil channel for the circulation of lubricating oil.

[0047] like Figure 1 , Figure 6 and Figure 7 As shown, the connecting oil passage 103 for connecting the lubricating oil pump outlet passage 102 and the cold filter module is formed by combining the cylinder groove 11 and the end cover groove 21. One end of the connecting oil passage 103 is connected to the lubricating oil pump outlet passage 102, and the other end is directly connected to the cold filter module front oil passage 104.

[0048] The main connecting oil passage 135 for connecting the first main lubricating oil passage 123 and the second main lubricating oil passage 141 in the engine cylinder (in this embodiment, there are two main lubricating oil passages, and it is not excluded that three or more main lubricating oil passages can be used) is formed by combining the cylinder groove 12 and the cylinder head groove 22. The change in the direction of the main connecting oil passage 135 is preferably a smooth transition, avoiding sharp turns, so as to reduce the flow resistance of the lubricating oil.

[0049] The structure of forming the connecting oil passage by precasting the groove avoids machining the connecting oil hole in the engine cylinder body by mechanical processing, which not only reduces the processing cost, but also the path of the connecting oil passage can be flexibly adjusted according to the structural layout requirements of the engine cylinder body 1 and the front cover 2 of the engine cylinder body, making full use of the space and making the engine cylinder body 1 more compact. The main connecting oil passage 135 is preferably wavy, and a section of oil storage cavity 136 with a depth and / or width greater than the rest is provided in the groove of the main connecting oil passage 135 located in the engine cylinder body 1. The provision of the oil storage cavity 136 can increase the oil storage amount in the engine cylinder body 1 after the engine is stopped, so that the lubrication system can establish the lubricating oil pressure faster when the engine is started again, avoiding the wear of the components at the end of the lubricating oil circuit; on the other hand, the design of this oil storage cavity 136 can also reduce the weight of the engine and meet the design requirements of the engine light weight.

[0050] In order to achieve effective sealing of the connecting oil passages, in this embodiment, a circle of sealing grooves 26 is preferably provided around the cylinder head grooves 21 , 22 , and sealing of the corresponding connecting oil passages is achieved by installing sealing rings in the sealing grooves 26 .

[0051] like Figure 1 and Figure 5As shown, in this preferred embodiment, the cold filter module oil inlet 105 and the cold filter module oil outlet 121 provided on the engine cylinder block are arranged adjacent to each other and open on the side of the engine cylinder block 1; the cold filter module front oil passage 104 is arranged horizontally in the longitudinal direction (parallel to the arrangement direction of the engine cylinders), one end of which is connected to the connecting oil passage 103 for receiving the lubricating oil that has been pressure-regulated from the lubricating oil pump oil outlet passage 102, and the other end of the cold filter module front oil passage 104 is connected to the cold filter module oil inlet 105 for conveying the lubricating oil to the cold filter module 6 for cooling and filtering; the connecting oil passage 122 for connecting the cold filter module oil outlet 121 with the first main lubricating oil passage 123 is arranged horizontally and transversely (perpendicular to the arrangement direction of the engine cylinders) in the engine cylinder block. The cold filter module 6 is directly mounted on the side of the engine block 1, and the cold filter module oil inlet 61 provided on the cold filter module 6 is communicated with the cold filter module oil inlet 105 provided on the engine block 1; the cold filter module oil outlet 62 provided on the cold filter module 6 is communicated with the cold filter module oil outlet 121 provided on the engine block 1. Preferably, grooves are provided around the cold filter module oil inlet 61 and the cold filter module oil outlet 62 on the cold filter module 6, and sealing rings are installed to achieve reliable communication with the cold filter module oil inlet 105 and the cold filter module oil outlet 121 and ensure sealing.

[0052] like Figure 1 , Figure 2 and Figure 6 As shown, the first main lubricating oil passage 123 and the second main lubricating oil passage 141 are two horizontal oil passages that longitudinally penetrate the front and rear ends of the engine cylinder block 1. The two main lubricating oil passages are connected via a connecting oil passage 135.

[0053] On the first main lubricating oil passage 123, several main bearing oil supply passages 124 are arranged obliquely toward the inside of the engine block. One end of the main bearing oil supply passage 124 is connected to the first main lubricating oil passage 123, and the other end is connected to the crankshaft hole 16 set on the engine block 1, so as to supply oil to the main bearing of the engine crankshaft. On the path of the first main bearing oil supply passage 124 near the front end face of the engine block 1, a front end face oil supply passage 130 is set. One end of the front end face oil supply passage 130 is connected to the first main bearing oil supply passage 124, and the other end leads to the front end face of the engine block 1, so as to supply oil to the idle gear shaft at the front end of the engine block. At the end of the first main bearing oil supply passage 124 near the crankshaft hole 16, an arc groove 131 is set along the outer circumferential surface of the crankshaft hole 16. Accordingly, multiple oil holes can be set on the upper bushing of the first main bearing to increase the cross-sectional area of ​​the lubricating oil flow, so as to ensure that the main bearing can still have sufficient oil film thickness when the front end of the engine crankshaft is subjected to a large lateral force.

[0054] On the path of the first main lubricating oil passage 123, several piston cooling nozzle oil supply passages 125 are arranged vertically downward, the upper end of the piston cooling nozzle oil supply passage 125 is connected to the first main lubricating oil passage 123, and the other end is directly connected to the oil inlet of the piston cooling nozzle to realize oil supply to the bottom of the piston. On the path of the first main lubricating oil passage 123, a side oil supply passage 126 is arranged horizontally, one end of the side oil passage 126 is connected to the first main lubricating oil passage 123, and the other end is opened to the side of the cylinder body to realize the supply of lubricating oil to the supercharger and other parts installed on the exhaust side of the engine. At the end of the first main lubricating oil passage 123 (corresponding to the rear end of the engine cylinder block, the rear end of the engine cylinder block refers to an end for setting the flywheel, and the other end opposite to the rear end of the engine cylinder block is the front end of the engine cylinder block), an oblique oil passage 127 is provided, and on the path of the oblique oil passage 127, a rear end face oil supply passage 128 is horizontally provided, and the rear end face oil supply passage 128 leads to the rear end face of the engine cylinder block 1 to realize oil supply to the idle gear shaft at the rear end of the engine cylinder block; in addition, a vertically downward bottom oil supply passage 129 is also provided, and the upper end of the bottom oil supply passage 129 is connected to the oblique oil passage 127, and the other end is directly connected to the bottom surface of the cylinder block 1, so as to realize oil supply to the balance shaft and other components located at the bottom of the engine cylinder block 1.

[0055] The second main lubricating oil passage 141 is located above the camshaft hole 17 and is arranged parallel to the central axis of the camshaft hole 17. On the path of the second main lubricating oil passage 141, several camshaft oil supply passages 142 and several cylinder head oil supply passages 143 are arranged at intervals, and the adjacent camshaft oil supply passages 142 and cylinder head oil supply passages 143 are the same vertical processing hole. The lower end of the vertical processing hole is connected to the camshaft hole 17, and the upper end is opened on the top surface of the cylinder body. The middle lower part of the vertical processing hole is cross-connected with the second main lubricating oil passage 141. The part of the vertical processing hole located below the second main lubricating oil passage 141 is the camshaft oil supply passage 142, which is used to supply oil to the camshaft hole 17, and the part of the vertical processing hole located above the second main lubricating oil passage 141 is the cylinder head oil supply passage 143, which is used to supply oil to the cylinder head valve mechanism, etc. With such a structural form, two functional oil passages, a camshaft oil supply passage and a cylinder head oil supply passage 143, can be formed at one time. Thereby reducing the processing steps and improving the production efficiency.

[0056] On the path of the second main lubricating oil channel 141, two side oil supply channels 144 and 145 are arranged at intervals in the horizontal direction. One end of the two side oil supply channels is vertically connected to the second main lubricating oil channel 141, and the other end directly leads to the side end surface of the engine cylinder block 1, so as to supply lubricating oil to the engine fuel pump, air compressor, lubricating oil parameter collection sensor and other components that require lubricating oil lubrication and cooling.

[0057] On the cylinder head oil supply passage 143 at the rear end of the engine cylinder block 1, a rear end face oil supply passage 146 is horizontally arranged, leading to the rear end face of the engine cylinder block 1, for supplying lubricating oil to the gear mechanism installed on the rear end face of the engine cylinder block.

[0058] The working principle of the present invention is as follows:

[0059] When the engine is started and running in the low speed range, the lubricating oil pump 3 sucks the lubricating oil into the lubricating oil pump through the lubricating oil pump inlet passage 101 and outputs it to the lubricating oil pump outlet passage 102. At this time, the lubricating oil system pressure is low, and the main pressure regulating valve 4 is in a closed state. The lubricating oil output from the lubricating oil pump outlet port 32 directly passes through the lubricating oil outlet passage 102, the connecting oil passage 103, the cold filter module front oil passage 104, the cold filter module oil inlet 105, and the cold filter module oil inlet 61 to enter the cold filter module 6; after the cold filter module The lubricating oil after cooling and filtering of block 6 enters the first main lubricating oil passage 123 through the cold filter module oil outlet 62, the cold filter module oil outlet 121, and the connecting oil passage 122, and then supplies lubricating oil to the main bearing, piston cooling nozzle, supercharger, engine cylinder front idle gear shaft, engine cylinder rear idle gear shaft and balance shaft system through the main bearing oil supply passage 124, piston cooling nozzle oil supply passage 125, side oil supply passage 126, front face oil supply passage 130, rear face oil supply passage 128, and bottom oil supply passage 129. At the same time, the connecting oil passage 135 transports the lubricating oil in the first main lubricating oil passage 123 to the second main lubricating oil passage 141, and then supplies lubricating oil to the camshaft, engine cylinder head, fuel pump, gear mechanism and other components through the camshaft oil supply passage 142, cylinder head oil supply passage 143, side oil supply passages 144, 145 and rear face oil supply passage 146.

[0060] When the engine is running in the high speed range, if the pressure at the oil outlet 32 ​​of the lubricating oil pump reaches and exceeds the opening pressure of the main pressure regulating valve 4, at this time, the plunger 41 is pushed open by the lubricating oil pressure in the oil inlet passage 111 of the pressure regulating valve and moves backward. In this process, when the oil drain hole 412 on the plunger 41 is connected with the parallel section 112 of the lubricating oil pump inlet passage in the oil drain passage, the excess lubricating oil will be discharged to the oil inlet 31 of the lubricating oil pump through the parallel section 112 of the lubricating oil pump inlet passage and the vertical section 113 of the lubricating oil pump inlet passage, and will be sucked back into the lubricating oil pump 3 to form a bypass loop for the excess lubricating oil. The remaining lubricating oil is still cooled and filtered by the cold filter module 6, and then supplied to various engine components through the first main lubricating oil passage 123 and the second main lubricating oil passage 141.

[0061] In this preferred embodiment, the opening pressure of the main pressure regulating valve 4 is set to the sum of the lubricating oil pressure required by the first main lubricating oil passage 123 and the pressure loss of the lubricating oil passage between the lubricating oil pump outlet 32 ​​and the connecting oil passage 122. The main pressure regulating valve cover 44 is installed on the side of the engine cylinder block 1, making the maintenance of the main pressure regulating valve 4 very convenient, and the adjusting gasket 43 can be designed to have different thicknesses, each thickness corresponding to a specific preset opening pressure of the main pressure regulating valve 4, so that the opening pressure of the main pressure regulating valve 4 can be changed by changing the thickness of the adjusting gasket 43.

[0062] In the above description, unless otherwise clearly defined, the terms "connected" and "connected" should be understood in a broad sense, for example, directly connected or indirectly connected through an intermediate medium. A first feature "above" a second feature includes the first feature being directly above and obliquely above the second feature, or simply means that the first feature is higher in level than the second feature.

[0063] In addition, in this specification, unless explicitly stated otherwise, the term “comprising” should be understood as including stated elements but not excluding other elements.

[0064] It should be noted that the above embodiments and embodiment drawings are only used to illustrate the present invention, but the present invention is not limited to the above embodiments. Any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention fall within the protection scope of the present invention.

Claims

1. An internal combustion engine lubrication system, comprising an engine block, an oil pan, a lubricating oil pump, a lubricating oil cooler and a lubricating oil filter, wherein the lubricating oil pump is arranged on the engine block and is used to suck and pressurize the lubricating oil from the oil pan to realize the flow of the lubricating oil in the lubricating oil channel, the lubricating oil cooler is used to cool the lubricating oil, and the lubricating oil filter is used to filter the lubricating oil, characterized in that: The lubricating oil passage comprises a lubricating oil pump inlet passage (101) and a lubricating oil pump outlet passage (102) arranged in the engine cylinder body, the lubricating oil pump inlet passage is connected to the lubricating oil pump through the lubricating oil pump inlet port (31), the lubricating oil pump outlet passage (102) is connected to the lubricating oil pump through the lubricating oil pump outlet port (32), a main pressure regulating valve (4) is arranged at the lubricating oil pump outlet port, a plunger cavity of the main pressure regulating valve is arranged in the engine cylinder body, one end of the plunger cavity is connected to the lubricating oil pump outlet passage (102), The plunger cavity (13) is connected to the engine cylinder block, and the other end extends toward the outside of the engine cylinder block and forms a plunger cavity opening on the surface of the engine cylinder block. A plunger (41) and a plunger spring (42) are arranged in the plunger cavity. The plunger spring (42) is arranged close to the plunger cavity opening. A main pressure regulating valve bonnet (44) is arranged at the plunger cavity opening. The plunger cavity (13) is connected to the lubricating oil pump oil inlet passage (101) through an oil drain passage. The main pressure regulating valve bonnet (44) is installed at the plunger cavity opening through a thread. 44) The part screwed into the plunger opening is provided with a hollow cavity, and the hollow cavity is provided with an adjustment pad (43) for supporting the plunger spring and being able to adjust the pre-pressure of the main pressure regulating valve; the plunger (41) comprises a large diameter section and a small diameter section, the large diameter section is provided with a blind hole opening toward the oil outlet channel of the lubricating oil pump, the blind hole opening end of the large diameter section is supported on the bottom of the plunger cavity, and a pressure regulating valve oil inlet channel (111) connected to the oil outlet channel (102) of the lubricating oil pump is provided at the bottom of the plunger cavity, and the plunger spring (42) is set Outside the small diameter section of the plunger, one end of the plunger spring (42) is supported on the end of the large diameter section, and the other end extends into the hollow cavity of the main pressure regulating valve cover (44) and abuts against the adjustment pad (43); a plurality of oil drain holes (412) are provided on the hole wall of the blind hole along the circumference of the blind hole, and the oil drain holes (412) can be connected to the oil drain channel in the process of the plunger spring (42) being depressurized by the oil inlet pressure; one end of the large diameter section provided with the blind hole is a toothed structure, and the tip of the tooth abuts against the bottom of the plunger cavity.

2. An internal combustion engine lubrication system according to claim 1, characterized in that: The part of the plunger cavity where the plunger spring is installed is the plunger spring cavity, and a through hole is provided between the plunger spring cavity and the crankcase.

3. An internal combustion engine lubrication system according to claim 1, characterized in that: The oil drain passage comprises a lubricating oil pump oil inlet passage parallel section (112) communicating with the plunger cavity and a lubricating oil pump oil inlet passage vertical section (113) connected to the lubricating oil pump oil inlet port (31).

4. An internal combustion engine lubrication system according to claim 1, characterized in that: A spare pressure regulating valve (5) is provided on a passage from the lubricating oil pump outlet (32) to the lubricating oil cooler and the lubricating oil filter, and the opening pressure of the spare pressure regulating valve (5) is greater than the opening pressure of the main pressure regulating valve (4).

5. An internal combustion engine lubrication system according to claim 1, characterized in that: A cylinder groove is precast on the front end face of the engine cylinder block, and an end cover groove which is consistent with the shape of the cylinder groove is precast on the front end cover of the engine cylinder block. The cylinder groove and the end cover groove are combined to form a connecting oil channel for the circulation of lubricating oil.

6. An internal combustion engine lubrication system according to claim 5, characterized in that: The connecting oil passage comprises a main connecting oil passage (135) for connecting a plurality of main lubricating oil passages in an engine cylinder, and the main connecting oil passage (135) is wavy in shape.

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