TW202325613A - Oil-cooled four-stroke engine for powered paragliding - Google Patents

Abstract

The present invention is related to an oil-cooled four-stroke engine for powered paragliding. The oil-cooled four-stroke engine has an engine body, a parachute holder, an engine oil cooler, and an oil cooling pipe fitting assembly. An engine oil channel is defined through the engine body, the parachute holder is mounted on one side of the engine body and the engine oil cooler is mounted on the parachute holder. The engine oil cooler communicates with the engine oil channel of the engine body through the oil cooling pipe fitting assembly. Therefore, the oil cooling pipe fitting assembly can supply the engine oil cooled by the engine oil cooler to the engine body to cool and lubricate the engine body. The oil-cooled four-stroke engine of the present invention is lightened accordingly to decrease a weight loading of paragliding user and gasoline consumption.

Description

Oil-cooled four-stroke engine for powered paragliders

The invention relates to a four-stroke engine, in particular to a four-stroke engine used for a powered parachute.

A powered paraglider is a paraglider that is used with a propeller engine. It is widely used in the field of aviation sports because of its characteristic of achieving long-lasting flight with the thrust provided by the propeller engine.

Please refer to Fig. 7, it is a kind of water-cooled four-stroke engine 60 that can be used as propeller engine, the displacement of this water-cooled four-stroke engine 60 is 250c. pipe 63 and a hot water pipe 64, wherein the water tank 61 is arranged and fixed on one side of the engine body 62, and includes a cooling water outlet 611 and a cooling water inlet 612, the cooling water outlet 611 and the cooling water inlet 612 of the water tank 61 Cooling water inlet 612 is respectively connected with this cold water pipe 63 and this hot water pipe 64, and this cold water pipe 63 is connected with this engine body 62, enters and cools this engine body 62 for a cooling water of this water tank 61, and this cooling water is in After absorbing the heat generated by the engine body 62 , it leaves the engine body 62 and returns to the water tank 61 through the hot water pipe 64 . In this water-cooled four-stroke engine 60, the engine body 62 must increase the thickness of the meat to form a water passage (not shown), so that the engine body 62 containing an exhaust pipe as shown in FIG. The weight of this water-cooled four-stroke engine 60 has reached 18 kilograms, plus the weight of the water tank 61, the cold water pipe 63, the hot water pipe 64 and the cooling water, making the overall gross weight of the water-cooled four-stroke engine 60 up to 23 to 25 kilograms.

As can be seen from the above description, the water-cooled four-stroke engine is the power source of the powered paraglider, but in order to achieve the goal of long-distance flight, it is necessary to maintain the engine body within a certain temperature range, and the currently known four-stroke engine used by the powered paraglider The engine adopts a water-cooled heat dissipation method, that is, the water tank must be hung outside the engine body, and the water tank and the cooling water significantly increase the volume and weight of the four-stroke engine, increase the weight burden of the user when taking off and landing, and fuel consumption during flight , it is necessary to further improve it.

In view of the overweight overall weight of the above-mentioned water-cooled four-stroke engine, which leads to the disadvantages of increased weight burden on the user and increased fuel consumption, the main purpose of the present invention is to provide an oil-cooled four-stroke engine for a powered parachute.

For reaching above-mentioned purpose, the main technical means that the present invention uses is to make the above-mentioned oil-cooled four-stroke engine that is used for power parachute comprise: An engine body comprising at least a crankcase, a cylinder, a cylinder head, and an oil passage, wherein the oil passage runs through the crankcase, the cylinder, and a side wall of the cylinder head, and is connected to a cam of the cylinder head shaft chamber connection; A parachute fixing frame is arranged on the front side of the engine body; An engine oil cooler is arranged on one side of the parachute fixing frame; and An oil cooling pipe set is connected with the oil cooler and the oil channel of the engine body.

As can be seen from the above description, the oil-cooled four-stroke engine used in the power parachute of the present invention forms the oil passage inside the engine body, and hangs the oil cooler on one side of the engine body, and then uses the oil cooler The pipe fittings are connected to the oil passage and the oil cooler, and the oil cooling pipes can introduce the oil cooled by the oil cooler into the engine body, because the oil passes through the oil passage through the crankshaft of the engine body Tank, the cylinder and the cylinder head can absorb the excess heat produced by the fuel oil burned in the cylinder, and can also lubricate the internal components of the engine body at the same time, so the oil-cooled four-stroke engine of the present invention does not need to use an external Cool the water tank to achieve the goal of reducing the weight of the engine, reduce the weight burden of the user when taking off and landing, and reduce the fuel consumption for flight.

The present invention mainly proposes an oil-cooled four-stroke engine for a powered parachute. The technical content of the present invention will be described in detail below with examples and drawings.

At first please refer to Fig. 1, a power parachute system uses an oil-cooled four-stroke engine 1 of the present invention, and comprises a fuel tank 2, an engine frame 3, a back type parachute 4 (umbrella surface is not drawn) and a Propeller 5, wherein the bottom surface of the oil-cooled four-stroke engine 1 is provided with the fuel tank 2 to send a fuel into the oil-cooled four-stroke engine 1, and the rear side of the oil-cooled four-stroke engine 1 is connected to the propeller 5. The propeller 5 provides a thrust to the powered parachute. The oil-cooled four-stroke engine 1 and the fuel tank 2 are fixed together in the engine frame 3, and the front side of the engine frame 3 is fixed to the back paraglider 4 for a person to carry the power parachute on his back.

Please refer to Fig. 2 and Fig. 3 again, above-mentioned oil-cooled four-stroke engine 1 system comprises an engine body 10, a parachute fixing frame 20, an oil cooler 30 and an oil cooling pipe fitting group 40, and this engine body 10 system comprises A crankcase 11, a cylinder 12, a cylinder head 13 and an oil passage 14, wherein the oil passage 14 runs through the crankcase 11, the cylinder 12 and a side wall of the cylinder head 13, and is connected with the inside of the cylinder head 13 One of the camshaft chambers 131 communicates.

The specific structure of the engine body 10 of the oil-cooled four-stroke engine 1 is further described below. Please continue to refer to FIGS. 2 and 3. In this embodiment, the crankcase 11 of the engine body 10 further includes an oil tank 110 , a front crankcase 111, a rear crankcase 112 and a crankcase 113, wherein the oil tank 110 extends downward from the bottom of the crankcase 11, the front and rear crankcases 111, 112 are combined with each other, the crankshaft Chamber 113 is formed between the front crankcase 111 and the rear crankcase 112, and the crankcase 113 communicates with the sump 110; as shown in Figure 4A and Figure 4B, the front side of the front crankcase 111 An oil outlet 141 and an oil inlet 142 are formed.

Please refer to Fig. 2, the outside system of this front crankcase 111 of above-mentioned engine body 10 is fixed with a cover plate 15, and this cover plate 15 is positioned between this front crankcase 111 of this engine body 10 and this parachute fixed mount 20, And the cover plate 15 includes a hot machine oil outlet 151 and a cold machine oil inlet 152, as shown in FIG. is in communication with the oil inlet 142 of the front crankcase 111 .

Please refer to Fig. 3, the outer side of the rear crankcase 112 of the above-mentioned engine body 10 extends upwards with a Pulley shaft fixing post 114, wherein the Pulley shaft fixing post 114 is for a propeller Pulley shaft 115 to pass through and be fixed. The propeller pulley shaft 115 is connected to a propeller drive wheel 116 positioned at the rear side of the rear crankcase 112, and the propeller drive wheel 116 is connected to the propeller 5 shown in Figure 1; again as shown in Figure 5A and Figure 5B, The rear side and the front side of the Pulley shaft fixing column 114 are integrally formed with a plurality of longitudinal reinforcing arms 114b, and a plurality of transverse reinforcing ribs 114a are further formed between adjacent longitudinal reinforcing arms 114b to reinforce the Pulley shaft fixing column 114, when reducing the propeller 5 of the above-mentioned powered parachute, the stress concentration of the Puli shaft fixing column 114 of the rear crankcase 112 caused; in this embodiment, the front side of the Puli shaft fixing column 114 and Three longitudinal reinforcing arms 114b are respectively formed on the rear side, and two transverse reinforcing ribs 114a are formed on the rear side of the Pulley shaft fixing column 114, but both are not limited thereto.

In this embodiment, as shown in Figure 3, a crankshaft assembly 117 is arranged inside the crank chamber 113 of the above-mentioned crankcase 11, and the two ends of the crankshaft assembly 117 protrude from the front side and the front side of the front crankcase 111 respectively. The rear side of the rear crankcase 112, the end of the crankshaft assembly 117 passing through the rear side of the rear crankcase 112 is connected to the propeller drive wheel 116 of the rear crankcase 112 through a belt 118, so that the power is passed through the belt 118 The power is transmitted to the propeller drive wheel 116, and the power is further transmitted to the propeller 5 of the powered parachute shown in FIG. 1 .

As shown in Figure 2, the cylinder 12 of the above-mentioned engine body 10 is fixed on an outside of the crankcase 11; On the crankcase 11 ; as shown in FIG. 3 , the cylinder 12 includes a cavity 121 , and the cavity 121 runs through the cylinder 12 to match a piston 119 arranged on the crankshaft assembly 117 .

As shown in Figure 2, the cylinder head 13 of the above-mentioned engine body 10 is fixed on the cylinder 12, and as shown in Figure 3 and Figure 6A, the cylinder head 13 includes a combustion chamber 134, and the combustion chamber 134 is connected to the cylinder The cavity 121 of 12 communicates intermittently with the movement of the piston 119; in this embodiment, please refer to FIG. The threaded slots 16 are used for multiple studs 17 to pass through and fix. The camshaft chamber 131 of the cylinder head 13 is for a camshaft 133, two valve rocker arms, two intake valves and two exhaust valves (these components are the existing components of the engine, so they are omitted and will not be repeated. ) is disposed therein, and the cylinder head 13 includes a timing internal sprocket chamber 132, which is located behind the camshaft chamber 131 and communicates with the camshaft chamber 131, and further penetrates The rear side of the cylinder 12 and the rear crankcase 112 of the crankcase 11 communicate with the oil tank 110 and the crank chamber 113, wherein the timing internal chain gear chamber 132 contains a timing chain 135, the timing The timing chain 135 will pass through the camshaft chamber 131 and pass through the camshaft 133 in the timing internal chain gear chamber 132 to connect with the crankshaft assembly 117 located in the rear crankcase 112, and the timing chain 135 will The power of the crankshaft assembly 117 is transmitted to the camshaft 133, so as to utilize the valve rocker arms connected with the camshaft 133 to control the opening and closing sequence of the intake valves and the exhaust valves; In this embodiment, a side of the cylinder head 13 corresponding to the exhaust valves is connected to an exhaust pipe 136 to discharge an exhaust gas generated by the combustion chamber 134 out of the engine body 10 .

The specific structure of the engine oil passage 14 of the above-mentioned engine body 10 is further described below. Please refer to FIG. 5C and FIG. 6A. and a second channel 146; as shown in Figure 6A, the first channel 143 is communicated with the oil inlet 142 on the front side of the front crankcase 111, and runs through the front crankcase 111, the cylinder 12 and the cylinder head 13 The side wall; refer to Fig. 4A and Fig. 4B again, the part of the first channel 143 corresponding to the front crankcase 111 is sequentially upward, backward, and to the outside of the cylinder 12 on the front side of the front crankcase 111. Part of one of the threaded grooves 16 is formed to communicate with the first channel 143 corresponding to the side wall of the cylinder 12; in this embodiment, as shown in Figure 6A, the first channel 143 corresponds to the cylinder 12 and The part of the cylinder head 13 can directly be the threaded slot 16 through which a stud 17 passes, so it is not necessary to form it additionally; The portion includes an inner passage 148 , and the first passage 143 communicates with the camshaft chamber 131 through the inner passage 148 .

As shown in Figure 4B, the sub-passage 144 of the above-mentioned engine oil passage is formed in the front crankcase 111 to communicate with the part of the first passage 143 corresponding to the front crankcase 111 and the crank chamber 113; in this embodiment , the inner diameter of the sub-channel 144 is smaller than the inner diameter of the first channel 143 of the oil channel 14 , but not limited thereto.

As shown in FIG. 5C , the return passage 145 of the oil passage is formed in the rear crankcase 112 to communicate with the timing internal chain gear chamber 132 and the oil case 110 .

As shown in FIG. 6A, the second channel 146 of the above-mentioned engine oil channel communicates with the engine oil outlet 141 of the front crankcase 111, and is formed in the front crankcase 111 to communicate with the engine oil tank 110 of the crankcase 11. In this embodiment, the oil channel 14 further includes an oil pump 147, the oil pump 147 is fixed in the front crankcase 111, and connected in series between the second channel 146 and the oil tank 110 As shown in Figure 3 again, the oil pump 147 is connected with the crankshaft assembly 117 inside the crankcase 11 with a chain, so that the oil pump 147 utilizes the power of the crankshaft assembly 117 to transport the oil tank The engine oil in 110 enters the second passage 146 of the oil passage 14 .

As shown in Figure 3, the parachute fixing frame 20 of the above-mentioned oil-cooled four-stroke engine 1 is arranged on the front side of the engine body 10, and forms a plurality of parachute fixing arms 21, one side of the parachute fixing frame 20 A transverse arm 22 is formed and connected to the parachute fixed arms 21 on the side, wherein the parachute fixed arms 21 are for the oil-cooled four-stroke engine 1 to be fixed on the engine frame 3 of the above-mentioned powered parachute, In this embodiment, the paraglider fixing frame 20 has four paragliding fixing arms 21, but it is not limited thereto, and the cross arm 22 formed on one side of the paragliding fixing frame 20 is connected to the The two parachute fixing arms 21 are used for fixing the oil cooler 30 .

As shown in Figure 2, the oil cooler 30 of the above-mentioned oil-cooled four-stroke engine 1 is arranged on one side of the parachute fixing frame 20, and includes a cooler body 31, a front fixing plate 32 and a rear fixing 33, wherein the cooler body 31 includes a hot machine oil inlet 311 and a cold machine oil outlet 312; as shown in Figure 2, in this embodiment, the front fixing piece 32 and the rear fixing piece 33 are fixed on the On the cross arm 22 of the parachute fixing frame, the oil cooler 30 is sandwiched between the front fixing piece 32 and the rear fixing piece 33 .

As shown in FIG. 2 , the oil cooling pipe assembly 40 of the above-mentioned oil-cooled four-stroke engine 1 includes a heating oil pipe 41 and a cooling oil pipe 42, wherein the heating oil pipe 41 and the cooling oil pipe 42 are respectively connected to the engine body 10 In the present embodiment, the hot oil pipe 41 is respectively connected to the hot oil inlet 311 of the oil cooler 30 and the hot oil outlet 151 of the cover plate 15 of the engine body 10, and the cold oil pipe 42 connects the cold machine oil inlet 312 of the oil cooler 30 and the cold machine oil inlet 152 of the cover plate 15 of the engine body 10 respectively, and the hot machine oil pipe 41 passes the machine oil in the machine oil channel 14 through the hot machine oil outlet 151 is sent into this machine oil cooler 30 to cool, and this machine oil of cooling is sent back this cold machine oil inlet 152 through this cold machine oil pipe 42 again and enters this engine body 10.

The process of the above-mentioned oil-cooled four-stroke engine 1 using the oil cooler 30 and the oil to cool the engine body 10 is further described below. Please refer to FIG. 2 and FIG. The cold machine oil outlet 312 is used as a starting point. As shown in FIG. 2, a cold machine oil exiting from the oil cooler 30 flows into the cold machine oil pipe 42 from the cold machine oil outlet 312 of the cooler body 31, and then passes through the cover. The cold engine oil inlet 152 of the plate 15 enters the cover plate 15, and then, as shown in FIG. As explained above, since the inner diameter of the sub-passage 144 is smaller than the inner diameter of the first passage 143, a large part of the cooling oil flows to the threaded groove 16 of the cylinder 12 through the first passage 143, that is, the second A channel 143 corresponds to a part of the cylinder 12 , and a small part enters the sub-channel 144 and flows to the crank chamber 113 of the crankcase 11 .

Please refer to Fig. 6A and 6B again, after the above-mentioned cold machine oil passes through the front crankcase 111 through the first passage 143, it flows to the threaded groove 16 of the cylinder 12, that is, the first passage 143 corresponds to the cylinder 12 and the first passage 143. The portion of the cylinder head 13 that absorbs excess heat generated by the combustion chamber 134 of the cylinder head 13 to thereby cool the engine block 10 and form a hot oil that then enters the camshaft chamber through the inner passage 148 131; the above-mentioned thermal engine oil enters the timing internal chain gear chamber 132 after passing through the camshaft chamber 131 of the cylinder head 13, and then the thermal engine oil is drawn by gravity to flow through the timing internal chain gear chamber 132 to the rear crankcase 112 , as shown in FIG. 5C, after the engine oil flowing out of the crank chamber 113 from a bottom of the timing internal chain gear chamber 132 in the rear crankcase 112 merges, the thermal engine oil flows back to the crankshaft through the return passage 145 The oil tank 110 of the tank 11.

As shown in Figure 6A, after the above-mentioned hot engine oil is collected in the sump 110 of the crankcase 11, it is pressurized by the oil pump 147 arranged between the sump 110 and the second channel 146 and passes through the second channel 146. passage 146, then leaves the front crankcase 111 from the engine oil outlet 141 of the front crankcase 111, and the hot engine oil passes through the hot engine oil outlet 151 and the hot engine oil pipe 41 in sequence, and then the hot engine oil from the engine oil cooler 30 The machine oil inlet 311 enters the cooler body 31, and finally the hot machine oil is cooled by the cooler body 31 to form the above-mentioned cold machine oil and enter the cold machine oil pipe 42 through the cold machine oil outlet 312 for recirculation; in this embodiment, because the oil The cold four-stroke engine 1 utilizes the machine oil cooler 30 to make the machine oil cool and lubricate simultaneously, and the maximum oil temperature of the hot machine oil can be reduced to within 100 degrees. This oil-cooled four-stroke engine 1 as shown in Figure 2 The total weight of the water-cooled four-stroke engine 60 that is equipped with the water tank 61, the cold water pipe 63, the hot water pipe 64 and the cooling water in Fig. 7 is 23 to 25 kilograms. The total weight of the oil-cooled four-stroke engine 1 of the present invention can be reduced by about 6-8 kilograms; taking the specifications of the cylinder bore of the present embodiment as 73 mm and the stroke of the crankshaft as an example, the oil-cooled four-stroke engine of the present invention The displacement of 1 is about 284.17c.c (73*73*3.1415*67.9/1000), so compared with the 250c.c water-cooled four-stroke engine shown in Figure 7, the displacement of 34.17cc is increased.

As can be seen from the above description, the oil-cooled four-stroke engine of the present invention forms the oil passage inside the engine body, and sets and fixes the oil cooler on one side of the parachute fixing frame, and then uses an oil cooling pipe assembly Connecting the oil passage and the oil cooler, the hot oil pipe of the oil cooling pipe set guides the hot oil inside the engine body from the oil outlet of the oil passage to the oil cooler to cool the hot oil And make it form the cooling machine oil, and then continue to use the cooling machine oil pipe of the oil cooling pipe assembly to guide the cooling machine oil back to the oil inlet of the oil passage, and enter the engine body for repeated circulation, so that the machine oil can simultaneously cool and lubricating effect; in addition, the present invention integrally forms a plurality of horizontal reinforcement ribs and a plurality of longitudinal reinforcement arms on the front side and rear side of the pulley shaft fixing column of the rear crankcase of the engine body to reinforce the pulley shaft fixing column, reducing the stress concentration of the rear crankcase caused when the propeller is used; in this way, the oil-cooled four-stroke engine used in the power parachute of the present invention can use the oil cooler to cool the machine oil without an external cooling water tank And indirectly cool the engine body, really reduce the weight of the oil-cooled four-stroke engine, reduce the weight burden of the user and the fuel consumption of the flight.

The above description is only an embodiment of the present invention, and does not limit the present invention in any form. Although the present invention has been disclosed as above with the embodiment, it is not intended to limit the present invention. Anyone with ordinary knowledge in the technical field, Within the scope of not departing from the technical solution of the present invention, when the technical content disclosed above can be used to make some changes or be modified into equivalent embodiments with equivalent changes, but all the content that does not depart from the technical solution of the present invention, according to the technical essence of the present invention Any simple modifications, equivalent changes and modifications made to the above embodiments still fall within the scope of the technical solution of the present invention.

1: Oil-cooled four-stroke engine 2: Fuel tank 3: Engine frame 4: Back parachute 5: propeller 10: engine body 11: crankcase 110: engine oil tank 111: Front crankcase 112: Rear crankcase 113: Crankshaft chamber 114: Pulley shaft fixing column 115: propeller pulley shaft 116: propeller drive wheel 117: crankshaft assembly 118: belt 119: Piston 12: Cylinder 121: cavity 13: cylinder head 131: Camshaft chamber 132: Timing inner sprocket chamber 133: Camshaft 134: Combustion chamber 135: Timing chain 136: Exhaust pipe 14: Engine oil channel 141: Engine oil outlet 142: engine oil inlet 143: first channel 144: sub-channel 145: return channel 146:Second channel 147:Oil pump 148: Inner channel 15: Cover plate 151: Outlet of hot engine oil 152: Inlet of cold engine oil 16: Screw groove 17: Stud 20: Flying parachute fixing frame 21: Flying parachute fixing arm 22: cross arm 30: oil cooler 31: Cooler body 311: Thermal engine oil inlet 312 Cold engine oil outlet 32: Front fixed piece 33: Rear fixed piece 40: Oil cooling pipe fitting group 41: Oil pipe for hot engine 42: Oil pipe for cold engine 60: Water-cooled four-stroke engine 61: Water tank 611: cooling water outlet 612: cooling water inlet 62: Engine body 63: Cold water pipe 64: hot water pipe

Fig. 1: A schematic diagram of using the power parachute of the oil-cooled four-stroke engine of the present invention. Figure 2: A perspective view of the oil-cooled four-stroke engine of the present invention. Fig. 3: An exploded perspective view of the oil-cooled four-stroke engine of the present invention. Figure 4A: A perspective view of a front crankcase of the oil-cooled four-stroke engine of the present invention. Fig. 4B: A cross-sectional view of the A-A section line of Fig. 4A. Figure 5A: A perspective view of a rear crankcase of the oil-cooled four-stroke engine of the present invention. Figure 5B: A perspective view of a rear crankcase of the oil-cooled four-stroke engine of the present invention. Fig. 5C: A cross-sectional view of the section line B-B in Fig. 5A. FIG. 6A : a partial perspective view of FIG. 2 . Fig. 6B: Partial rear perspective exploded view of the oil-cooled four-stroke engine of the present invention. Fig. 7: A three-dimensional view of an existing water-cooled four-stroke engine.

1: Oil-cooled four-stroke engine

10: Engine body

11: Crankcase

111: Front crankcase

12: Cylinder

13: cylinder head

15: cover plate

151: Hot engine oil outlet

152: Cold engine oil inlet

20: Flying parachute holder

21: Flying parachute fixed arm

30: Oil cooler

31: cooler body

311: Hot engine oil inlet

312: Cold engine oil outlet

32: Front fixed piece

33: rear fixed piece

40:Oil cooling pipe fittings group

41: Heat engine oil pipe

42: Cold engine oil pipe

Claims (10)

An oil-cooled four-stroke engine for a powered parachute, comprising: An engine body comprising at least a crankcase, a cylinder, a cylinder head, and an oil passage, wherein the oil passage runs through the crankcase, the cylinder, and a side wall of the cylinder head, and is connected to a cam of the cylinder head shaft chamber connection; A parachute fixing frame is arranged on the front side of the engine body; An engine oil cooler is arranged on one side of the parachute fixing frame; and An oil cooling pipe set is connected with the oil cooler and the oil channel of the engine body. An oil-cooled four-stroke engine for a powered parachute as claimed in claim 1, wherein: The crankcase system consists of: an oil tank extending downwardly from the bottom of the crankcase; a front crankcase, a front side of which forms an oil inlet and an oil outlet; a rear crankcase coupled to the front crankcase; and a crank chamber formed between the front crankcase and the rear crankcase and communicating with the oil tank; and The cylinder head includes a timing internal chain gear chamber, which is located behind the camshaft chamber and communicates with the camshaft chamber, and the timing internal chain gear chamber runs through the rear side of the cylinder and the crankcase The rear crankcase, and communicate with the oil tank of the crankcase. An oil-cooled four-stroke engine for a powered parachute as claimed in claim 2, wherein the oil channel includes: A first passage communicates with the engine oil inlet of the front crankcase, passes through the front crankcase, the cylinder and the side wall of the cylinder head, and communicates with the camshaft chamber of the cylinder head; a sub-channel is formed in the front crankcase to communicate with the first channel and the crank chamber; a return passage formed in the rear crankcase to communicate with the timing internal chain gear chamber and the oil tank; and A second passage is formed in the front crankcase to communicate with the oil tank. An oil-cooled four-stroke engine for a powered parachute as claimed in claim 3, wherein: The cylinder and the cylinder head are sequentially fixed by a plurality of studs on an outer side of the crankcase, wherein the outer side of the crankcase and the side wall of the cylinder and the cylinder head form a threaded groove corresponding to each of the studs; The part of the first channel corresponding to the side wall of the cylinder and the cylinder head is one of the threaded grooves; and The part of the first passage of the engine oil passage corresponding to the cylinder head includes an inner passage, and the first passage communicates with the camshaft chamber through the inner passage. For example, the oil-cooled four-stroke engine used for a powered parachute in claim 3 or 4 further includes an oil pump, which is fixed in the front crankcase and connected in series to the second channel and between the oil tanks. An oil-cooled four-stroke engine for a powered parachute as in claim 5, wherein: The parachute fixing frame system includes: a plurality of paraglider arms; and a cross arm connecting two of the parachute fixed arms; and The oil cooler system consists of: A front fixing piece is fixed on the cross arm of the parachute fixing frame; a rear fixing piece fixed to the cross arm of the paraglider fixing frame; and A cooler body is sandwiched between the front fixing piece and the rear fixing piece. An oil-cooled four-stroke engine for a powered parachute as claimed in item 6, wherein: The outer side of this front crankcase of this engine body is fixed with a cover plate, and this cover plate is positioned between this front crankcase of this engine body and this parachute fixing frame, and it comprises: a cold machine oil inlet connected to the cold machine oil pipe of the oil cooling pipe assembly and communicated with the oil inlet of the front crankcase; and a hot engine oil outlet connected to the hot oil pipe of the oil cooling tube set and communicated with the oil outlet of the front crankcase; and This oil cooling tubing set consists of: a thermal oil pipe connected to the thermal oil inlet of the cooler body and the thermal oil outlet of the cover; and A cold machine oil pipe is connected to the cold machine oil outlet of the cooler body and the cold machine oil inlet of the cover plate. The oil-cooled four-stroke engine for a powered parachute as claimed in claim 3, wherein the inner diameter of the sub-channel of the oil passage is smaller than the inner diameter of the first passage of the oil passage. An oil-cooled four-stroke engine for a powered parachute as claimed in claim 2, wherein a pulley shaft fixing column extends upward from the outer side of the rear crankcase, which includes: A plurality of longitudinal reinforcement arms are integrally formed on the front and rear sides of the Pulley shaft fixing column; and A plurality of transverse reinforcing ribs are respectively formed between adjacent longitudinal reinforcing arms on the rear side of the Pulley shaft fixing column. An oil-cooled four-stroke engine for a powered parachute as claimed in claim 9, wherein the pulley shaft fixing column of the rear crankcase is used for a propeller pulley shaft to pass through and be fixed, and the propeller pulley shaft is connected A propeller driving wheel.