Lubricating system for variable compression ratio engine
Technical Field
The invention relates to a lubricating system, belongs to the technical field of vehicle engines, and particularly relates to a lubricating system for a variable compression ratio engine.
Background
In recent years, a number of patents have been published on reciprocating engines having variable compression ratio mechanisms in which it is necessary to provide pressurized lubricating oil via a lubrication system to assist in the movement of the variable compression ratio mechanism, as well as to lubricate the moving parts of the variable compression ratio adjustment mechanism via the lubricating oil. The present invention discloses an overall arrangement and strategy for a lubrication system for a reciprocating engine with a variable compression ratio mechanism. From the description of international patents WO98/51911, WO00/31377, WO03/008783, a number of special mechanical devices for variable compression ratio engines are known. From the above mentioned patent it can be noted that the mechanical transmission of a variable compression ratio engine comprises at least one cylinder in which a piston moves, the lower part of which is fixed to a transmission member which, on the one hand, cooperates with a rolling guide device through a pinion and, on the other hand, cooperates with a gear fixedly connected to the connecting rods through another large rack, so as to transmit between said connecting rods. Said mechanical device for a variable compression ratio engine also comprises at least one control rack cooperating with a gear. The moving parts such as the gear, the rack and the bearing of the compression ratio adjusting device need to be lubricated separately. In addition, the cylinder for adjusting the compression ratio also requires high-pressure hydraulic oil. Chinese patent CN101375033 discloses an oil spray lubricating and cooling device for a variable compression ratio engine. The device is mainly used for cooling and lubricating the compression ratio adjusting device.
Variable compression ratio engines are known to those skilled in the art and it is noted that none of the presently disclosed documents disclose the lubrication oil circuit and the hydraulic oil circuit portion of a variable compression ratio engine. This patent is through increasing high-pressure oil circuit part on the basis at present traditional engine lubrication oil circuit, provides the machine oil source through traditional oil pump, provides the high pressure through high-pressure oil circuit part. The high-pressure part pushes the variable compression ratio hydraulic adjusting mechanism to work, and the low-pressure part lubricates parts such as gears of the variable compression ratio hydraulic adjusting mechanism. The pressure and lubrication requirements of a variable compression ratio engine can be achieved with less variation over conventional engines.
Disclosure of Invention
In view of the above-mentioned drawbacks of the prior art, the present invention provides a lubrication system for a variable compression ratio engine, which is used in the reciprocating engine with a variable compression ratio mechanism, and in addition to the lubrication of the conventional lubrication elements, such as the crankshaft, camshaft, chain, piston pin, etc., the lubrication of the variable compression ratio adjustment mechanism is also required. And the hydraulic oil required for the variable compression ratio adjusting mechanism is also supplied from the engine main oil pump.
In order to solve the technical problem, the invention adopts the lubricating system for the variable compression ratio engine, which comprises an engine main oil gallery connected with a variable displacement oil pump and a high-pressure hydraulic unit connected with the engine main oil gallery; the high-pressure hydraulic unit comprises a high-pressure electric oil pump, a high-pressure stabilizing cavity and a high-pressure oil duct; the engine main oil duct is connected with the input end of the high-pressure electric oil pump, the output end of the high-pressure electric oil pump is connected with the input end of the high-pressure stabilizing cavity, the output end of the high-pressure stabilizing cavity is connected with the high-pressure oil duct, and the output port of the high-pressure oil duct is connected with a compression ratio control solenoid valve and a variable compression ratio lateral pressure mechanism.
In a preferred embodiment of the present invention, the high-pressure oil passage includes a main oil passage and two branch oil passages, and the main oil passage is connected to the branch oil passages through three valves; and one branch oil duct is connected with the variable compression ratio side pressure mechanism, and the other branch oil duct is connected with the compression ratio control electromagnetic valve.
In a preferred embodiment of the invention, the engine main oil gallery is provided with a variable compression ratio adjusting gear lubricating nozzle.
In a preferred embodiment of the present invention, the engine oil in the engine main oil gallery flows into the high-pressure electric oil pump, the high-pressure electric oil pump pressurizes the engine oil to 30bar, and the high-pressure oil of the high-pressure electric oil pump flows into the high-pressure surge chamber.
In a preferred embodiment of the present invention, the variable compression ratio side pressure mechanism includes an installation base, a guide cylinder is connected to the installation base, a piston capable of moving along an axis direction of the guide cylinder is connected to the guide cylinder in a sliding fit manner, a groove extending along an axial direction of the piston is formed in the piston, an oil passage communicated with the groove is formed in the installation base, and a check valve is arranged at one end of the oil passage communicated with the groove.
In a preferred embodiment of the present invention, the oil passage includes a main oil passage and an auxiliary oil passage, one end of the auxiliary oil passage is communicated with the main oil passage, the other end of the auxiliary oil passage is communicated with the groove, and a check valve is disposed in the auxiliary oil passage
In a preferred embodiment of the present invention, an end surface of the piston facing the control tooth plate is a flat surface.
In a preferred embodiment of the invention, a spring is arranged in the recess of the piston.
In a preferred embodiment of the invention, the guide cylinder is provided with a flange.
In a preferred embodiment of the present invention, the mounting base is provided with a connecting boss, and the connecting boss is sleeved with a guide cylinder; and an auxiliary oil duct with one end communicated with the main oil duct and the other end communicated with the groove is arranged on the connecting boss.
The invention has the beneficial effects that: the high-pressure oil way part is added on the basis of the lubricating oil way of the traditional engine, the traditional oil pump is used for providing engine oil source, and the high-pressure oil way part is used for providing high-pressure engine oil, so that the compression ratio hydraulic adjusting mechanism is pushed to work, and the pressure and lubricating requirements of the variable compression ratio engine are met by ensuring that the variable compression ratio hydraulic adjusting mechanism changes less on the traditional engine; meanwhile, through the structural design of the variable compression ratio lateral pressure mechanism, the main oil duct and the auxiliary oil duct one-way valve are arranged on the original mounting base and are matched with the piston, so that the guide rails of the engine are contacted with each other to keep the stability of the operation of the power transmission device, and the complex machining procedure of forming the oil duct on the cylinder block is avoided; according to the invention, the spring is arranged in the piston, so that the piston is prevented from acting on the control toothed plate when external high-pressure engine oil cannot be normally supplied or the side presser leaks.
Drawings
FIG. 1 is an overall layout of a lubrication system for a variable compression ratio engine according to an embodiment of the present invention;
FIG. 2 is a diagram of the high pressure hydraulic section of a lubrication system for a variable compression ratio engine according to an embodiment of the present invention;
FIG. 3 is a diagram of the high pressure hydraulic section of a lubrication system for a variable compression ratio engine according to an embodiment of the present invention;
FIG. 4 is a variable compression ratio adjustment gear lubrication nozzle for a lubrication system of a variable compression ratio engine according to an embodiment of the present invention;
FIG. 5 is a variable compression ratio adjustment gear lubrication nozzle axis view of a lubrication system for a variable compression ratio engine according to an embodiment of the present invention;
FIG. 6 is a bottom view of a variable compression ratio adjustment gear lubrication nozzle for a lubrication system of a variable compression ratio engine in accordance with an embodiment of the present invention;
FIG. 7 is a top view of a variable compression ratio adjustment gear lubrication nozzle for a lubrication system of a variable compression ratio engine in accordance with an embodiment of the present invention;
FIG. 8 is a schematic structural diagram of a variable compression ratio side pressure mechanism of a lubrication system for a variable compression ratio engine according to an embodiment of the present invention;
fig. 9 is a schematic diagram showing the detailed internal structure of the variable compression ratio side pressure mechanism of the lubrication system for the variable compression ratio engine according to the embodiment of the present invention.
In the figure: the system comprises a 1-variable displacement oil pump, a 2-pressure release valve, a 3-check valve, a 4-oil filter, a 5-oil cooler, a 6-supercharger, a 7-oil pump, an 8-piston cooling nozzle, a 9-chain tensioning device, a 10-OCV valve, a 11-oil pump feedback oil circuit, a 12-oil pump control electromagnetic valve, a 13-piston cooling nozzle control valve, a 14-oil pressure and temperature sensor, a 15-high-pressure hydraulic unit, a 16-compression ratio control electromagnetic valve, a 17-side pressing device, an 18-variable compression ratio adjusting gear lubricating nozzle, a 20-high-pressure electric oil pump, a 21-high-pressure stabilizing cavity, a 22-high-pressure oil channel and a 24-compression ratio control electromagnetic valve.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
The lubricating system for the variable compression ratio engine shown in the attached drawings of the specification of the invention comprises an engine main oil gallery 19 (the variable displacement oil pump 1 supplies oil pressure and oil flow to the whole lubricating system) connected with a variable displacement oil pump 1 (the variable displacement oil pump 1 supplies the pressure and flow required by the engine according to the load and the rotating speed of the engine, the oil supplied by the variable displacement oil pump 1 is filtered by an oil filter 4, then is cooled by an oil cooler 5 and enters the engine main oil gallery 19), and a high-pressure hydraulic unit 15 connected with the engine main oil gallery 19; the high-pressure hydraulic unit 15 comprises a high-pressure electric oil pump 20, a high-pressure stabilizing cavity 21 and a high-pressure oil channel 22; the engine main oil duct 19 is connected with the input end of a high-pressure electric oil pump 20, the output end of the high-pressure electric oil pump 20 is connected with the input end of a high-pressure stabilizing cavity 21, the output end of the high-pressure stabilizing cavity 21 is connected with a high-pressure oil duct 22, and the output port of the high-pressure oil duct 22 is connected with a compression ratio control solenoid valve 24 and a variable compression ratio lateral pressure mechanism 26. The high-pressure oil duct 22 comprises a main oil duct 22-1 and two branch oil ducts 22-2, and the main oil duct 22-1 is connected with the branch oil ducts 22-2 through three valves; one branch oil passage 22-2 is connected with a variable compression ratio side pressure mechanism 26 (enough pressure oil is supplied for compressing a toothed plate and a gear of the variable compression ratio adjusting mechanism), and the other branch oil passage 22-2 is connected with a compression ratio control electromagnetic valve 24 (the variable compression ratio mechanism of the reciprocating engine of the variable compression ratio mechanism needs a high-pressure hydraulic mechanism to assist in opening and closing the compression ratio adjusting electromagnetic valve to control whether a compression ratio control cylinder is filled with oil or not, and finally controls the operation of the compression ratio adjusting mechanism of the engine to adjust the compression ratio of the engine). The engine main oil gallery 19 is provided with a variable compression ratio adjusting gear lubricating nozzle 27 (which can ensure good lubricating performance of a variable compression ratio adjusting mechanism gear and a toothed plate), the variable compression ratio adjusting gear lubricating nozzle 27 at least comprises an oil inlet 27-2 and two oil injection ports 27-1, and the two oil injection ports 27-1 are symmetrically arranged relative to the oil inlet 27-2. The engine oil in the engine main oil gallery 19 flows into a high-pressure electric oil pump 20, the high-pressure electric oil pump 20 pressurizes the engine oil to 30bar, and the high-pressure oil of the high-pressure electric oil pump 20 flows into a high-pressure stabilizing cavity 21. The variable compression ratio side pressure mechanism comprises a mounting base 31, wherein a guide cylinder 32 is connected onto the mounting base 31, a piston 33 capable of moving along the axial direction of the guide cylinder 32 is connected onto the guide cylinder 32 in a sliding fit mode, a groove 38 extending along the axial direction of the piston 33 is formed in the piston 33, another main oil channel 35 used for oil injection is formed in the mounting base 31, external high-pressure engine oil is introduced into the auxiliary oil channel 36 from the other main oil channel 35, one end of the auxiliary oil channel 36 is communicated with the other main oil channel 35, the other end of the auxiliary oil channel is communicated with the groove 38, a one-way valve 37 is arranged in the auxiliary oil channel 36, and the engine oil can only flow into the groove 38 of the. The end surface of the piston 33 facing the control tooth plate is a plane. In order to prevent the external high-pressure oil from being abnormally supplied or the side presser from leaking, a spring 41 is provided in the groove 38 of the piston 33, and the spring 41 continuously acts on the piston 33. A flange 42 is provided on the guide cylinder 32 for axial positioning on the cylinder block. The auxiliary oil passage 36 is arranged coaxially with the groove 38. A second sealing ring 40 is arranged between the inner wall of the guide cylinder 32 and the outer wall of the piston 33. The mounting base 31 is provided with a connecting boss 34, and the connecting boss 34 is sleeved with a guide cylinder 32. The connecting boss 34 is provided with an auxiliary oil passage 36 having one end communicating with the other main oil passage 35 and the other end communicating with the groove 38. A first sealing ring 39 is arranged between the inner wall of the guide cylinder 32 and the outer wall of the connecting boss 34. The mounting base 31 is provided with a plurality of connecting bosses 34 arranged in parallel.
It should be understood that the above are only specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily made by those skilled in the art within the technical scope of the present invention disclosed herein should be covered within the scope of the present invention.