CN118008609A - Air-cooled gasoline engine four-valve cylinder cover assembly, engine and general machine - Google Patents

Abstract

The invention relates to a four-valve cylinder cover assembly of an air-cooled gasoline engine, an engine and a general machine, comprising a cylinder cover, a cylinder cover and a spark plug, wherein a relief space for installing the spark plug is formed in a side tank of the cylinder cover and the cylinder cover, the cylinder cover comprises an upper cylinder cover and a lower cylinder cover which are integrally formed, an air cooling channel is formed at the interval between the upper cylinder cover and the lower cylinder cover, the upper cylinder cover is provided with a four-valve channel communicated with the lower cylinder cover, the four-valve channel is provided with a valve structure for opening and closing the air inlet channel and the air outlet channel, a driving structure for controlling the opening and closing of the valve structure is arranged in a mounting cavity, and an oil-gas separator for separating engine oil in oil gas is arranged in the cylinder cover; the adoption of the overhead spark plug exerts excellent performance under high compression ratio.

Description

Air-cooled gasoline engine four-valve cylinder cover assembly, engine and general machine

Technical Field

The invention belongs to the technical field of engines, and relates to an air-cooled gasoline engine four-valve cylinder cover assembly, an engine and general machinery.

Background

The four-valve technology is a necessary configuration on the motorcycle and automobile engine, and the engine speed is limited by the power condition and the generator speed in the general low efficiency in the general field of general engine speed without significant attention.

The combustion chamber, the combustion chamber structure and the air passage arrangement form of the three-valve engine disclosed by the application number CN201920017747.6 are characterized in that an air inlet wedge surface for installing an air inlet valve, an air outlet wedge surface for installing an exhaust valve and a spark plug wedge surface for installing a spark plug are arranged at the top of the combustion chamber, and spherical surfaces are adopted except for the air inlet wedge surface, the air outlet wedge surface and the spark plug wedge surface. The invention is carried out by redesigning the structure of the combustion chamber, combines the design of the air inlet throat opening and the air outlet throat opening with the design of the air inlet channel and the air outlet channel, not only simplifies the structure, the manufacturing process and the cost of the combustion chamber, but also has the characteristics of high tumble ratio, high vortex strength, small heat loss, full combustion and the like, and can effectively reduce the resistance loss of the air inlet and the air outlet of the engine, thereby improving the external performance and the fuel economy performance of the engine

However, in the above-described scheme, the patent adopts a three-valve two-in-one-row system, and the exhaust back pressure of this system is large, so that the exhaust side temperature is high, and the superiority of two intake valves is not exhibited.

Disclosure of Invention

The invention aims to solve the problems in the prior art and provides a four-valve cylinder cover assembly of an air-cooled gasoline engine, an engine and general machinery.

The aim of the invention can be achieved by the following technical scheme: the utility model provides an air-cooled petrol engine four-valve cylinder head subassembly, includes cylinder head, cylinder head cover and spark plug, one side incasement sunken formation that is used for installing the spark plug give way the space, the cylinder head that shows includes integrated into one piece's last cylinder head and lower cylinder head, the interval between last cylinder head and the lower cylinder head forms the forced air cooling passageway, last cylinder head on be provided with the four valve passageway with the cylinder head intercommunication down, four valve passageway on be provided with the valve structure that is used for opening and close inlet channel and air outlet channel, last cylinder head on set up the installation cavity, the installation cavity in be provided with the actuating structure that is used for controlling valve structure and open and close, the cylinder head cover in be provided with the oil and gas separator that separates the engine oil in the oil gas.

In the air-cooled gasoline engine four-valve cylinder cover assembly, the four-valve channel comprises an inlet valve guide pipe and an outlet valve guide pipe which are connected with the upper cylinder cover and the lower cylinder cover, the inlet valve guide pipe is communicated with the upper cylinder cover and the lower cylinder cover to form an inlet channel, the outlet valve guide pipe is communicated with the upper cylinder cover and the lower cylinder cover to form an outlet channel, the valve structure is arranged on the inlet channel and is an inlet valve, and the valve structure is arranged on the outlet channel and is an outlet valve. The two air inlet valve guide pipes and the two air outlet valve guide pipes are respectively arranged, the two same two air inlet valve guide pipes or air outlet valve guide pipes are positioned on the same side, the upper cylinder cover is respectively provided with an air inlet pipe and an air outlet pipe, the air inlet pipe is communicated with the two air inlet channels, and the air outlet pipe is communicated with the two air outlet channels.

In the four-valve cylinder cover assembly of the air-cooled gasoline engine, the driving structure comprises a mounting seat in a mounting cavity and a rocker arm rotationally connected with the mounting seat, one end of the rocker arm is provided with an adjusting stud, the adjusting stud is provided with a valve bridge, the valve structure is arranged at two ends of the valve bridge, the mounting seat is provided with a mounting notch, the contact surface of the mounting notch and the rocker arm is inclined at the same angle with the valve structure, two ends of the bottom of the valve bridge are provided with mounting round holes, one side of the rocker arm is provided with an elliptical hole, the other side of the rocker arm is provided with a body with a central hole, two ends of the body are respectively provided with a first rocker arm and a second rocker arm, one end of the first rocker arm is provided with a mounting threaded hole for mounting the adjusting stud, the second rocker arm is provided with a mounting hole seat, and the mounting hole seat is used for mounting the tappet.

In the air-cooled gasoline engine four-valve cylinder cover assembly, the upper cylinder cover is provided with the installation cavity, the driving structure comprises an installation upright post arranged in the installation cavity, a rocker arm arranged on the installation upright post and an adjusting stud arranged on the rocker arm, a rotating shaft is arranged between the two installation upright posts, the rocker arm is arranged on the rotating shaft, the other end of the adjusting stud is connected with a valve rod, the rocker arm controls the valve structure to be opened and closed through a tappet, and an oil return hole allowing the tappet to pass is formed in the bottom of the cylinder cover.

In the four-valve cylinder cover assembly of the air-cooled gasoline engine, the rocker arm comprises a sleeve sleeved on the rotating shaft, a first mounting rod arranged on one side of the sleeve and a second mounting rod arranged on the other side of the sleeve, a first mounting hole for mounting an adjusting stud is formed in the first mounting rod, the second mounting rod is curved in an arc shape, a second mounting hole for mounting a tappet rod is formed in the other end of the second mounting rod, and the second mounting hole is located right above the oil return hole. By the arrangement, the rocker arm can simultaneously control the opening and closing of two air inlet valves or air outlet valves at one side, so that the air inlet and exhaust efficiency is improved; because the cylinder cover is provided with the abdication space, the cylinder cover is U-shaped when overlooking, and the second mounting rod is arranged into an arc-shaped bent shape, so that the distribution of the internal structure of the cylinder cover is more reasonable.

In the four-valve cylinder cover assembly of the air-cooled gasoline engine, the oil-gas separator comprises a channel frame, a first guide plate, a second guide plate, a third guide plate and a pressing plate pad, wherein the first guide plate is used for separating the channel frame into an air inlet chamber and a first channel, a second channel is formed between the first guide plate and the second guide plate, a third channel is formed between the second guide plate and the third guide plate, the first channel, the second channel and the third channel are communicated to form an oil-gas channel, and a breathing tube is arranged on one side of the cylinder cover and is communicated with the oil-gas channel.

In the air-cooled gasoline engine four-valve cylinder cover assembly, the pressing plate pad is provided with the through hole, the through hole is communicated with the air inlet chamber, the through hole is provided with the mounting plate, the mounting plate is provided with the reed, the reed shields the through hole, and the mounting plate is provided with the limiting piece for limiting the spring-up position of the reed.

In the air-cooled gasoline engine four-valve cylinder cover assembly, the bottom of the lower cylinder cover is recessed upwards to form a cavity, the spark plug is arranged at the top of the cavity, and the upper end of the spark plug is positioned in the air-cooled channel.

In a second aspect, a gravity cast four valve engine includes a cylinder as described in any of the preceding claims.

In a third aspect, a gravity casting four-valve universal machine further comprises the engine.

Compared with the prior art, the engine has higher tumble ratio than the traditional die-casting cylinder head by adopting gravity casting, can reduce the size of the air inlet and the air outlet, and has excellent mechanical property; the cylinder adopts the overhead spark plug to exert excellent performance under high compression ratio; the flow coefficient is larger by adopting the left and right inclined four valves; the designed rocker arm support and control arm structure can reduce cam pressure and friction force; the cylinder head cover is made of aluminum alloy and is internally provided with an oil-gas separator, so that the oil-gas separation is more thorough, and oil injection is avoided.

Drawings

FIG. 1 is a schematic diagram of the structure of the present invention;

FIG. 2 is a schematic view of a structure without a wind scooper according to the present invention;

FIG. 3 is a schematic diagram of the cylinder and valve structure installation of the present invention;

FIG. 4 is a schematic diagram of the cylinder structure of the present invention;

FIG. 5 is a schematic view of the valve bridge structure of the present invention;

FIG. 6 is a schematic view of the rocker arm structure of the present invention;

FIG. 7 is a schematic view of another cylinder structure according to the present invention;

FIG. 8 is a side view of another cylinder of the present invention;

FIG. 9 is a bottom view of the cylinder of the present invention;

FIG. 10 is a schematic view of another valve configuration of the present invention;

FIG. 11 is a schematic view of the cylinder head structure of the present invention;

FIG. 12 is a bottom view of the cylinder head of the present invention;

FIG. 13 is a flow chart of the oil apparatus of the present invention;

FIG. 14 is a schematic view of the cavity structure of the present invention;

Figure 15 is a schematic view of the reed structure of the present invention. .

In the figure, 1, a cylinder cover; 101. an upper cylinder cover; 102. a lower cylinder cover; 2. a cylinder head cover; 3. a cavity; 4. an oil and gas channel; 41. a channel frame; 411. a second filter block; 5. a breathing tube; 6. a reed; 7. a limiting piece; 8. an air cooling channel; 9. an air inlet pipe; 10. an air outlet pipe; 11. an intake valve guide; 12. a vent valve guide; 13. a valve structure; 131. a valve stem; 132. a valve seat insert; 133. a spring seat; 134. a spring; 135. a valve tube; 136. valve oil seal; 14. an extension; 15. a driving structure; 151. installing an upright post; 152. a rocker arm; 153. adjusting a stud; 154. a rotating shaft; 16. a chamber; 17. a spark plug; 18. a wind scooper; 19. a heat radiation fin; 20. a mounting groove; 21. a mounting cavity; 41. a channel frame; 42. a first guide plate; 43. a second guide plate; 44. a third guide plate; 45. a platen pad; 46. an intake chamber; 47. a first channel; 48. a second channel; 49. a third channel; 410. a first filter block; 22. positioning holes; 23. an oil return passage; 31. a body; 32. a swing arm I; 33. swing arm II; 34. installing a threaded hole; 35. a mounting hole seat; 41. adjusting the stud; 51. valve bridge; 71. a mounting notch; 81. installing a round hole; 91. a push rod; 101. a boss; 111. rocker arm pin.

Detailed Description

The following are specific embodiments of the present invention and the technical solutions of the present invention will be further described with reference to the accompanying drawings, but the present invention is not limited to these embodiments.

Examples

As shown in fig. 1 to 15, a four-valve cylinder head assembly of an air-cooled gasoline engine comprises a cylinder head 1 and a cylinder head cover 2 arranged on the cylinder head 1, wherein a cavity 3 is formed in one side, facing the cylinder head 1, of the cylinder head cover 2, an oil-gas separator is arranged in the cavity 3, the oil-gas separator comprises a channel frame 41, a first guide plate 42, a second guide plate 43, a third guide plate 44 and a pressure plate pad 45, the pressure plate pad 45 is used for fixing the channel frame 41 through screws to enable an oil-gas channel 4 to be sealed, the first guide plate 42 is in a cross shape, the second guide plate 43 is in an L shape, the third guide plate 44 is in a straight shape, the first guide plate 42 is separated into an air inlet chamber 46 and a first channel 47 with the channel frame 41, a second channel 48 is formed between the first guide plate 42 and the second guide plate 43, and a third channel 49 is formed between the second guide plate 43 and the third guide plate 44. The first channel 47, the second channel 48 and the third channel 49 are communicated to form the oil-gas channel 4, a first filter block 410 is arranged at the joint of the first channel 47 and the second channel 48, and a second filter block 411 is arranged on the third channel 49. In this embodiment, the first filter block 410 and the second filter block 411 are made of a filter wire.

In order to discharge the oil gas in the oil gas channel 4, a breathing tube 5 is arranged on one side of the cylinder head cover 2, and the breathing tube 5 is communicated with the oil gas channel 4.

The pressure plate pad 45 on set up the through-hole, through-hole intercommunication air inlet chamber 46, the through-hole on be provided with the mounting panel, the mounting panel on be provided with reed 6, reed 6 shelter from the through-hole, the mounting panel on be provided with the spacing piece 7 that is used for restricting reed 6 bullet position. When the engine is started, the air pressure in the cylinder cover 1 is larger than the air pressure in the air inlet chamber 46, at the moment, the reed 6 is sprung by upward pressure, the through hole is opened, oil gas enters the air inlet chamber 46, and otherwise, the reed 6 is closed.

When the engine works, the engine piston moves from the upper dead point to the lower dead point, the gas with engine oil lubricates the matching piece of the rocker arm 152 on the cylinder head through the lower cylinder cover, and meanwhile, the reed 6 is opened, so that the pressure of the gas in the cylinder is reduced through the oil gas channel 4 and the breathing tube 5, and oil leakage is avoided. When the oil gas passes through the oil gas channel 4, the oil drops with large inertia are continuously separated from the gas and remain on the wall surface, and the small oil drops are continuously separated from the gas and remain through the first filter block 410 and the second filter block 411, so that the gas discharged from the breathing tube 5 basically does not contain engine oil.

When the engine piston moves from the bottom dead center to the top dead center, the pressure in the crankcase (not shown) is reduced to lower the pressure of cylinder head gas, the reed 6 is reset, air outside the breathing tube 5 is sucked into the cylinder head through the oil-gas channel 4 and through holes in the oil-gas separator pressing plate, and meanwhile, the separated engine oil in the oil-gas separator is sucked into the cylinder head 1 along with the air flow under the action of the negative pressure and the dead weight to return to the crankcase.

The cylinder head 1 includes integrated into one piece's last cylinder cap 101 and lower cylinder cap 102, and last cylinder cap 101 is the U type setting, forms air-cooled channel 8 between last cylinder cap 101 and the lower cylinder cap 102, is provided with a plurality of intake valve pipe 11 and valve pipe 12 on the lower cylinder cap 102, intake valve pipe 11 intercommunication upper cylinder cap 101 and lower cylinder cap 102 form the inlet channel, valve pipe 12 intercommunication upper cylinder cap 101 and lower cylinder cap 102 form the outlet channel, last cylinder cap 101 on seted up installation cavity 21, intake valve pipe 11 and valve pipe 12 are provided with two respectively, and are located the both sides of installation cavity 21 respectively, last cylinder cap 101 on be provided with intake pipe 9 and outlet duct 10 respectively, intake pipe 9 be linked together with two inlet channels, outlet duct 10 are linked together with two outlet channels.

In this embodiment, the air outlet pipe 10 is connected with the carburetor, and the air outlet pipe 10 is connected with the muffler.

And the air inlet channel and the air outlet channel are provided with air valve structures 13, and the air valve structures 13 are used for opening and closing the air inlet channel and the air outlet channel. The air inlet valve is arranged on the air inlet channel, and the air outlet valve is arranged on the air outlet channel. A driving structure 15 for controlling the opening and closing of the valve structure 13 is arranged in the mounting cavity 21.

The installation cavity 21 is provided with an extension part 14, the extension part 14 is sleeved on the intake valve guide pipe 11 and the outlet valve guide pipe 12 and forms a height difference with the tops of the intake valve guide pipe 11 and the outlet valve guide pipe 12, and in the embodiment, the tops of the intake valve guide pipe 11 and the outlet valve guide pipe 12 are higher than the extension part 14. The arrangement of the extension part 14 can enable the valve oil seal 136 to be sleeved on the valve guide 12 and the part of the valve guide 12 higher than the extension part 14, and the lower part of the valve oil seal 136 is abutted against the extension part 14, so that the tightness between the valve oil seal 136 and the intake valve guide 11 is improved, and oil is placed into a cylinder.

The valve structure 13 comprises a valve rod 131, a valve seat ring 132 is arranged at the bottom end of the valve rod 131, a spring seat 133 is arranged on the valve rod 131, a spring 134 is downwards arranged on the spring seat 133, a valve tube 135 is arranged below the spring 134, the valve tube 135 is sleeved on the valve rod 131, a valve oil seal 136 is arranged on the valve tube 135, and the lower end face of the valve oil seal 136 is in interference with the extending part 14.

In this embodiment, as shown in fig. 2 to 6, the driving structure 15 includes a mounting seat 151 in the mounting cavity 21, and a rocker arm 152 rotatably connected to the mounting seat 151, one end of the rocker arm 152 is provided with an adjusting stud 41, the adjusting stud 41 is provided with a valve bridge 51, the valve structure 13 is disposed at two ends of the valve bridge 51, and the valve bridge 51 enables the rocker arm 152 to simultaneously control two intake valves or two exhaust valves to be synchronously opened or closed.

The mounting seat 151 is further provided with a rocker arm 152 pin, the rocker arm 152 pin penetrates through the center hole, and the rocker arm 152 rotates on the mounting seat 151 through the rocker arm 152 pin.

The mounting seat 151 is provided with a mounting notch 71, the contact surface of the mounting notch 71 and the rocker arm 152 is inclined at the same angle as the valve structure 13, and the lateral thrust of the rocker arm 152 to the mounting seat 151 can be reduced and the loss of energy can be reduced by arranging the contact surface of the mounting groove 20 and the rocker arm 152 at the same angle as the valve structure 13.

The valve bridge 51 bottom both ends begin to have the installation round hole 81, one side of rocking arm 152 is the round hole, and the opposite side is the oval hole, rocking arm 152 include the body 31 that has the centre bore, the both ends of body 31 set up swing arm one 32 and swing arm two 33 respectively, the one end of swing arm one 32 be provided with the installation screw hole 34 that is used for installing adjusting stud 41, swing arm two 33 on be provided with mounting hole seat 35, mounting hole seat 35 be used for installing the tappet.

The valve bridge 51 is provided with the boss 101, the boss 101 and the adjusting stud 41 are arranged in a straight line, and the boss 101 is arranged on the valve bridge 51, so that the contact point between the adjusting stud 41 and the valve bridge 51 is not easy to wear, and the reliability is improved.

As another technical solution, as shown in fig. 7 to 11, the driving structure 15 includes a mounting column 151 disposed in the mounting cavity 21, a rocker arm 152 disposed on the mounting column 151, and an adjusting stud 153 disposed on the rocker arm 152, a rotation shaft 154 is disposed between two of the mounting columns 151, the rocker arm 152 is disposed on the rotation shaft 154, the other end of the adjusting stud 153 is connected to the valve stem 131, and the rocker arm 152 controls the opening and closing of the valve structure 13 through a tappet.

The rocker arm 152 comprises a sleeve arranged on the rotating shaft 154, a first mounting rod arranged on one side of the sleeve and a second mounting rod arranged on the other side of the sleeve, wherein the first mounting rod is provided with a first mounting hole for mounting the adjusting stud 153, the second mounting rod is curved in an arc shape, the other end of the second mounting rod is provided with a second mounting hole for mounting the tappet, and the second mounting hole is positioned right above the oil return hole 22. By the arrangement, the rocker arm 152 can simultaneously control the opening and closing of two intake valves or exhaust valves at one side, so that the air intake and exhaust efficiency is improved; because the cylinder cover 1 is provided with the abdication space, the cylinder cover 1 is U-shaped in a overlook view, and the second mounting rod is arranged in an arc-shaped bent shape, so that the internal structure of the cylinder cover 1 is distributed more reasonably.

In this embodiment, taking the intake valve as an example, the lifter pushes up one end connected with the rocker arm 152 to descend, the rocker arm 152 rotates through the rotating shaft 154, one end of the adjusting stud 153 descends, the adjusting stud 153 is connected with the valve rod 131 to push the valve seat ring 132 at the lower end of the valve rod 131 to descend, the valve seat ring 132 opens the intake valve, the spring 134 compresses at the moment, otherwise, the lifter pulls down one end connected with the rocker arm 152 to descend, the rocker arm 152 rotates through the rotating shaft 154 to lift one end of the adjusting stud 153, the adjusting stud 153 is connected with the valve rod 131 to pull the valve seat ring 132 at the lower end of the valve rod 131, the valve seat ring 132 closes, and meanwhile, the resilience force of the spring 134 can push the spring 134 to lift the mounting upright 151, so that the valve rod 131 assists in closing the intake valve.

The bottom of the lower cylinder cover 102 is recessed upwards to form a chamber 16, a mounting groove 20 for mounting a valve seat ring 132 is formed in the top of the chamber 16, and when the valve structure 13 is closed, the valve seat ring 132 is embedded in the mounting groove 20.

The top of the chamber 16 is provided with a spark plug 17 embedded therein, and the upper end of the spark plug 17 is positioned in the air cooling channel 8.

The lower cylinder cover 102 is provided with a wind scooper 18, and the wind scooper 18 plays a role in guiding cooling wind.

The cylinder cover 1 is also provided with a plurality of radiating fins 19, and the radiating effect of the surface of the cylinder cover 1 can be improved by arranging the radiating fins 19.

Besides, the mounting cavity is provided with an oil return channel 23, and the oil return channel 23 is communicated with the oil return hole.

One side of the cylinder head 1 is provided with a positioning hole 22, and the positioning hole 22 can enable the air guide cover 18 to play a role in positioning during installation.

In a second aspect, a gravity cast four valve engine includes a cylinder as described in any of the preceding claims.

In a third aspect, a gravity casting four-valve universal machine further comprises the engine.

Claims (10)

1. The utility model provides an air-cooled petrol engine four-valve cylinder head subassembly, includes cylinder head (1), cylinder head cover (2) and spark plug (17), one side incasement of cylinder head (1) and cylinder head cover (2) sunken formation be used for installing space of stepping down of spark plug (17), cylinder head (1) that shows include integrated into one piece's last cylinder head (101) and lower cylinder head (102), interval formation forced air cooling passageway (8) between last cylinder head (101) and lower cylinder head (102), last cylinder head (1) on be provided with four-valve passageway with cylinder head (1) intercommunication down, four-valve passageway on be provided with valve structure (13) that are used for opening and closing inlet channel and outlet channel, last cylinder head (101) on set up installation cavity (21), installation cavity (21) in be provided with and be used for controlling driving structure (15) that valve structure (13) opened and closed, cylinder head cover (2) in be provided with the oil gas separator that separates out with oil in the oil gas.

2. The air-cooled gasoline engine four-valve cylinder cover assembly as set forth in claim 1, wherein: the four-valve channel comprises an air inlet valve guide pipe (11) and an air outlet valve guide pipe (12) which are connected with the upper cylinder cover (101) and the lower cylinder cover (102), the air inlet valve guide pipe (11) is communicated with the upper cylinder cover (101) and the lower cylinder cover (102) to form an air inlet channel, the air outlet valve guide pipe (12) is communicated with the upper cylinder cover (101) and the lower cylinder cover (102) to form an air outlet channel, the air valve structure (13) is positioned on the air inlet channel and is an air inlet valve, and the air valve structure (13) is positioned on the air outlet channel and is an air outlet valve four-valve cylinder cover assembly of the air-cooled gasoline engine according to claim 1, and is characterized in that: the two air inlet valve guide pipes (11) and the two air outlet valve guide pipes (12) are respectively arranged, the two same two air inlet valve guide pipes (11) or the two same air outlet valve guide pipes (12) are positioned on the same side, the upper cylinder cover (101) is respectively provided with an air inlet pipe (9) and an air outlet pipe (10), the air inlet pipe (9) is communicated with two air inlet channels, and the air outlet pipe (10) is communicated with two air outlet channels.

3. The air-cooled gasoline engine four-valve cylinder cover assembly as set forth in claim 2, wherein: the driving structure (15) comprises a mounting seat (151) in a mounting cavity (21), and a rocker arm (152) rotationally connected to the mounting seat (151), one end of the rocker arm (152) is provided with an adjusting stud (41), the adjusting stud (41) is provided with a valve bridge (51), the valve structure (13) is arranged at two ends of the valve bridge (51), the mounting seat (151) is provided with a mounting notch (71), the contact surface of the mounting notch (71) and the rocker arm (152) is obliquely arranged at the same angle with the valve structure (13), mounting round holes (81) are formed in two ends of the bottom of the valve bridge (51), one side of the rocker arm (152) is a round hole, the other side of the rocker arm is an elliptical hole, the rocker arm (152) comprises a body (31) with a center hole, two ends of the body (31) are respectively provided with a first rocker arm (32) and a second rocker arm (33), one end of the first rocker arm (32) is provided with a mounting threaded hole (34) for mounting the adjusting stud (41), and the second rocker arm (33) is provided with a tappet (35) for mounting the mounting hole (35).

4. The air-cooled gasoline engine four-valve cylinder cover assembly as set forth in claim 2, wherein: the driving structure (15) comprises a mounting upright post (151) arranged in a mounting cavity (21), a rocker arm (152) arranged on the mounting upright post (151) and an adjusting stud (153) arranged on the rocker arm (152), a rotating shaft (154) is arranged between the two mounting upright posts (151), the rocker arm (152) is arranged on the rotating shaft (154), the other end of the adjusting stud (153) is connected with a valve rod (131), the rocker arm (152) controls the valve structure (13) to be opened and closed through a tappet, and an oil return hole through which the tappet can pass is formed in the bottom of the cylinder cover (1).

5. The air-cooled gasoline engine four-valve cylinder cover assembly according to claim 3 or 4, wherein: the rocker arm (152) comprises a sleeve (1521) sleeved on a rotating shaft (154), a first mounting rod (1522) arranged on one side of the sleeve (1521) and a second mounting rod (1523) arranged on the other side of the sleeve (1521), wherein a first mounting hole (1524) for mounting an adjusting stud (153) is formed in the first mounting rod (1522), the second mounting rod (1523) is curved in an arc shape, a second mounting hole (1525) for mounting a tappet is formed in the other end of the second mounting rod (1524), and the second mounting hole (1525) is located right above the oil return hole.

6. The air-cooled gasoline engine four-valve cylinder cover assembly as set forth in claim 5, wherein: the oil-gas separator comprises a channel frame (41), a first guide plate (42), a second guide plate (43), a third guide plate (44) and a pressing plate pad (45), wherein the first guide plate (42) is used for separating the channel frame (41) into an air inlet chamber (46) and a first channel (47), a second channel (48) is formed between the first guide plate (42) and the second guide plate (43), a third channel (49) is formed between the second guide plate (43) and the third guide plate (44), the first channel (47), the second channel (48) and the third channel (49) are communicated to form an oil-gas channel (4), and one side of the cylinder head cover (2) is provided with a breathing tube (5), and the breathing tube (5) is communicated with the oil-gas channel (4).

7. The air-cooled gasoline engine four-valve cylinder cover assembly as set forth in claim 6, wherein: the pressure plate pad (45) on set up the through-hole, through-hole intercommunication air inlet chamber (46), the through-hole on be provided with the mounting panel, the mounting panel on be provided with reed (6), reed (6) shelter from the through-hole, the mounting panel on be provided with spacing piece (7) that are used for restricting reed (6) bullet position.

8. The four-valve cylinder cover assembly of the air-cooled gasoline engine, according to claim 7, wherein the bottom of the lower cylinder cover (102) is recessed upwards to form a cavity (16), the spark plug (17) is arranged at the top of the cavity (16), and the upper end of the spark plug (17) is positioned in the air-cooled channel (8).

9. A gravity cast four valve engine comprising a cylinder as claimed in any one of claims 1 to 8.

10. A gravity-cast four-valve universal machine comprising the engine of claim 9.