CN117508414A

CN117508414A - All-terrain vehicle

Info

Publication number: CN117508414A
Application number: CN202210920050.6A
Authority: CN
Inventors: 朱长钦; 刘欢; 娄峰; 杨陈
Original assignee: Zhejiang CFMOTO Power Co Ltd
Current assignee: Zhejiang CFMOTO Power Co Ltd
Priority date: 2022-07-29
Filing date: 2022-07-29
Publication date: 2024-02-06

Abstract

The invention discloses an all-terrain vehicle, which comprises: a frame; a body panel disposed at least partially on the frame; the walking assembly is used for supporting the all-terrain vehicle; a power assembly at least partially disposed on the frame, the power assembly comprising an engine and a generator; the engine comprises an air inlet channel and an oil injection assembly; the air inlet channel is provided with a first oil injection hole and a second oil injection hole, the oil injection assembly is at least partially arranged in the first oil injection hole, and the oil injection assembly is also at least partially arranged in the second oil injection hole. Through setting up two oil spout structures at the cylinder head, increased the coverage that the oil spout subassembly sprays out the oil beam, make fuel and air mix more abundant, increased the combustion efficiency of engine, promoted the economic nature of all-terrain vehicle.

Description

All-terrain vehicle

Technical Field

The invention relates to the field of vehicles, in particular to an all-terrain vehicle.

Background

All-terrain vehicles are also called as all-terrain four-wheel off-road locomotives, and the vehicles are simple and practical and have good off-road performance. In the traditional air passage injection structure of the all-terrain vehicle, an oil sprayer is arranged in each air inlet passage of an engine, fuel is injected into two air inlet passages of each cylinder, the coverage area of the oil sprayer is small, the fuel atomization effect is poor, and the oil sprayer is insufficiently mixed with air. And further, the combustion efficiency among the cylinders is inconsistent, the energy conversion among the cylinders is different, and a certain degree of waste is caused to fuel oil.

Disclosure of Invention

In order to solve the defects in the prior art, the invention aims to provide an all-terrain vehicle capable of improving combustion efficiency.

In order to achieve the purpose, the invention adopts the following technical scheme:

an all-terrain vehicle comprising a vehicle frame; a body panel at least partially disposed on the frame; the walking assembly is used for supporting the all-terrain vehicle; the power assembly is at least partially arranged on the frame and comprises an engine and a generator; the engine comprises an air inlet channel and an oil injection assembly; the air inlet channel is formed with a first oil spray hole and a second oil spray hole, the oil spray assembly is at least partially arranged in the first oil spray hole, and the oil spray assembly is also at least partially arranged in the second oil spray hole.

Further, a first distance D1 from the center of the first oil spraying hole to the center of the second oil spraying hole is more than or equal to 25mm and less than or equal to 50mm.

Further, a first distance D1 from the center of the first oil spraying hole to the center of the second oil spraying hole is more than or equal to 33.3mm and less than or equal to 40.7mm.

Further, the air inlet channel comprises a first air inlet channel, the oil injection assembly comprises a first oil injection mechanism and a second oil injection mechanism, the first oil injection mechanism is arranged in the first air inlet channel through a first oil injection hole, and the second oil injection mechanism is arranged in the first air inlet channel through a second oil injection hole.

Further, the engine further comprises a combustion chamber, and the air inlet channel further comprises a second air inlet channel and a third air inlet channel; one end of the second air inlet channel is connected to the combustion chamber, and the other end of the second air inlet channel is connected to the first air inlet channel; one end of the third intake passage is connected to the combustion chamber, and the other end of the third intake passage is connected to the first intake passage.

Further, a first air inlet is formed at one end, close to the combustion chamber, of the second channel, a second air inlet is formed at one end, close to the combustion chamber, of the third channel, the distance between the centers of circles of the first air inlet and the second air inlet is a second distance D2, and the first distance D1 and the second distance D2 are basically consistent.

Further, the equivalent aperture of the first air inlet is D3, and the structure of the second air inlet is basically consistent with that of the first air inlet.

Further, the engine also comprises a cylinder hole for bearing high-temperature and high-pressure gas, and the aperture of the cylinder hole is D4; the ratio of the equivalent aperture D3 of the first intake port to the aperture D4 of the cylinder bore is 0.33 or more and 0.47 or less.

Further, the ratio of the equivalent aperture D3 of the first intake port to the aperture D4 of the cylinder bore is 0.35 or more and 0.44 or less.

Further, the ratio of the equivalent aperture D3 of the first intake port to the aperture D4 of the cylinder bore is 0.37 or more and 0.42 or less.

Through setting the engine to two oil spout structures, increased the coverage of fuel in the air inlet channel, make air and fuel mix more abundant, increased the combustion efficiency of engine, promoted the economic nature of all-terrain vehicle.

Drawings

Fig. 1 is a schematic structural view of a first state of an all-terrain vehicle according to an embodiment of the present application.

Fig. 2 is a schematic structural view of a second state of the all-terrain vehicle in the embodiment of the present application.

Fig. 3 is a schematic structural view of a power assembly according to an embodiment of the present application.

Fig. 4 is an exploded view of a power assembly in an embodiment of the present application.

Fig. 5 is a cross-sectional view of a power assembly in an embodiment of the present application.

Fig. 6 is a schematic diagram of the connection of an intake manifold and a cylinder head in an embodiment of the present application.

Fig. 7 is a schematic diagram of an intake manifold in an embodiment of the present application.

Fig. 8 is a cross-sectional view of an intake manifold in an embodiment of the present application.

Fig. 9 is an enlarged view at a of fig. 6 in an embodiment of the present application.

Fig. 10 is a schematic illustration of the connection of a cylinder head and a seal in an embodiment of the present application.

Fig. 11 is a schematic view of a seal in an embodiment of the present application.

Fig. 12 is an enlarged view at B of fig. 10 in the embodiment of the present application.

Fig. 13 is a schematic view of an intake passage according to an embodiment of the present application at a first viewing angle.

Fig. 14 is a schematic view of an intake passage according to the embodiment of the present application at a second viewing angle.

Fig. 15 is a schematic view of a cylinder head in an embodiment of the present application.

Detailed Description

In order to make the present invention better understood by those skilled in the art, the technical solutions in the specific embodiments of the present invention will be clearly and completely described with reference to the accompanying drawings in the embodiments of the present invention.

As shown in fig. 1-3, an all-terrain vehicle 100 includes a frame 11, a body panel 12, a travel assembly 13, a transmission assembly 14, an engine 15, and a generator 16. The frame 11 is provided as a metal frame for supporting the body panel 12, the engine 15, the generator 16 and the transmission assembly 14. The body panel 12 is at least partially disposed on the frame 11 for protecting the ATV 100. Engine 15 and generator 16 together form a power assembly for ATV 100 that transmits power to traveling assembly 13 via transmission assembly 14, thereby moving traveling assembly 13. The power assembly is at least partially disposed on frame 11 to provide a source of power for ATV 100. For clarity of explanation of the technical solution of the present application, the front side, the rear side, the left side, the right side, the upper side, the lower side are also defined as shown in fig. 1.

As shown in fig. 2, as one implementation, the all-terrain vehicle 100 includes a first accommodation space 101 and a second accommodation space 102 distributed in a front-rear direction, wherein the first accommodation space 101 is disposed at a front side of the second accommodation space 102. Further, the first accommodation space 101 is provided as a cab for a driver to sit on the ATV 100, and the second accommodation space 102 is provided for a power module.

All-terrain vehicle 100 also includes an oil storage assembly (not shown) disposed at least partially on frame 11, and disposed within second receiving space 102. Further, the drive assembly 14 is configured as a drive shaft extending in a fore-aft direction of the ATV 100. To balance the weight of ATV 100, a power assembly is disposed in second receiving space 102, with the power assembly disposed on the left side of the drive shaft and an oil storage assembly disposed on the right side of the drive shaft. The weight of the all-terrain vehicle 100 in the left-right direction is balanced by the power assembly and the oil storage assembly, thereby balancing the weight distribution of the all-terrain vehicle 100. As another implementation, to balance the weight of the all-terrain vehicle 100, a power assembly is disposed in the second receiving space 102, and the power assembly is disposed on the right side of the drive shaft, and an oil storage assembly is disposed on the left side of the drive shaft. The weight of the all-terrain vehicle 100 in the left-right direction is balanced by the power assembly and the oil storage assembly, thereby balancing the weight distribution of the all-terrain vehicle 100. Through the arrangement, the mass center of the all-terrain vehicle 100 is moved forward, so that the control of the all-terrain vehicle 100 is facilitated, and the driving texture is improved.

As shown in fig. 2, the all-terrain vehicle 100 further includes a controller assembly 17, the controller assembly 17 being disposed in the second accommodation space 102 for controlling the all-terrain vehicle 100. The controller assembly 17 includes a first controller 171 and a second controller (not shown). The first controller 171 is used to control the power components of the ATV 100, and the output of the power of the generator 16, the start or stop of the engine 15, and the energy conversion between the engine 15 and the generator 16 are controlled by the first controller 171. The second controller is used for controlling electronic components of the all-terrain vehicle 100, wherein the electronic components refer to functional components such as a temperature control module, a lighting module, an instrument display module and the like which are arranged in the all-terrain vehicle 100. Specifically, the second controller is at least partially disposed on an upper side of the oil storage assembly.

As shown in fig. 3 and 4, as one implementation, the engine 15 includes a crankshaft linkage 151 and an outer housing assembly 159, the outer housing assembly 159 including a cylinder head 1592 and a crankcase 1594, the crankshaft linkage 151 including a crankshaft 1511 disposed on the crankcase 1594. When the power assembly is disposed on one side of the transmission assembly 14, the rotational centerline direction of the crankshaft 1511 is substantially parallel to the axial direction of the transmission assembly 14, and the generator 16 is disposed at least partially on the rear side of the engine 15. The first controller 171 is disposed in the second accommodation space 102, the first controller 171 is disposed at least partially on the upper side of the generator 16, and the first controller 171 is disposed near the cylinder head 1592. It will be appreciated that the generator 16 may also be at least partially disposed on the front side of the engine 15 when the rotational centerline direction of the crankshaft 1511 is substantially parallel to the axial direction of the transmission assembly 14. Through the arrangement, the weight distribution of the all-terrain vehicle 100 can be balanced, so that the mass center of the all-terrain vehicle 100 moves forward, the control of the all-terrain vehicle 100 is facilitated to be improved, and the driving texture is improved.

As another implementation, when the power assembly is disposed on one side of the transmission assembly 14, the rotational centerline direction of the crankshaft 1511 is substantially parallel to the axial direction of the transmission assembly 14, and the generator 16 is disposed at least partially on the rear side of the engine 15. The first controller 171 is disposed in the second accommodating space 102, and the first controller 171 is at least partially disposed at an upper side of the second controller. It will be appreciated that the generator 16 may also be at least partially disposed on the front side of the engine 15 when the rotational centerline direction of the crankshaft 1511 is substantially parallel to the axial direction of the transmission assembly 14. Through the arrangement, the weight distribution of the all-terrain vehicle 100 can be balanced, so that the mass center of the all-terrain vehicle 100 moves forward, the control of the all-terrain vehicle 100 is facilitated to be improved, the driving texture is improved, the high-voltage wire bundles are arranged in a concentrated mode, and the intersection of the high-voltage wire bundles and the low-voltage wire bundles is avoided.

As another implementation, when the power assembly is disposed on one side of the transmission assembly 14, the rotational centerline direction of the crankshaft 1511 is substantially perpendicular to the axial direction of the transmission assembly 14, the rotational centerline of the crankshaft 1511 extends substantially in the left-right direction of the all-terrain vehicle 100, and the generator 16 is disposed at least partially on the left side of the engine 15. The first controller 171 is disposed in the second accommodation space 102, and the first controller 171 is disposed at least partially on the upper side of the generator 16 and near the cylinder head 1592. It will be appreciated that the generator 16 may also be disposed at least partially to the right of the engine 15 when the rotational centerline direction of the crankshaft 1511 is substantially perpendicular to the axial direction of the transmission assembly 14. Through the arrangement, the weight distribution of the all-terrain vehicle 100 is balanced, the mass center of the all-terrain vehicle 100 is moved forward, the control of the all-terrain vehicle 100 is facilitated to be improved, and the driving texture is improved.

As another implementation, when the power assembly is disposed on one side of the drive shaft, the rotational centerline direction of the crankshaft 1511 is substantially perpendicular to the axial direction of the drive assembly 14, and the generator 16 is disposed at least partially on the left side of the engine 15. The first controller 171 is disposed in the second accommodating space 102, and the first controller 171 is at least partially disposed at an upper side of the second controller. It will be appreciated that the generator 16 may also be disposed at least partially to the right of the engine 15 when the rotational centerline direction of the crankshaft 1511 is substantially perpendicular to the axial direction of the transmission assembly 14. Through the arrangement, the weight distribution of the all-terrain vehicle 100 is balanced, so that the mass center of the all-terrain vehicle 100 moves forward, the control of the all-terrain vehicle 100 is facilitated to be improved, the driving texture is improved, the concentrated arrangement of high-voltage bundles is facilitated, and the crossing of the high-voltage bundles and the low-voltage bundles is avoided.

As shown in fig. 3 and 4, in particular, the outer housing assembly 159 further includes a cylinder head cover 1591, a cylinder head 1592, a cylinder block 1593, a crankcase 1594, and an oil pan 1595. A cylinder head cover 1591 is attached to one end of the cylinder head 1592 for sealing the cylinder head 1592 against leakage of lubricating oil in the cylinder head 1592. The end of the cylinder head 1592 remote from the cylinder head cover 1591 is connected to the cylinder block 1593, and the cylinder head 1592 and the cylinder block 1593 constitute a substantially sealed space for sealing gas and forming a space for combustion of the combustible mixture gas to withstand high-temperature and high-pressure gas generated when the engine 15 is operated. The end of the cylinder block 1593 remote from the cylinder head 1592 is connected to a crankcase 1594, and the cylinder block 1593 and the crankcase 1594 are basic structures of the engine 15. The oil pan 1595 is used for sealing the crankcase 1594, and the oil pan 1595 and the crankcase 1594 are connected to form an oil reservoir 1595a for collecting and storing lubricating oil dissociated in the engine 15. The generator 16 is disposed at one side of the crankcase 1594, and the generator 16 is driven to operate by the engine 15, thereby achieving the effect of converting mechanical energy into electrical energy.

As one implementation, the outer housing assembly 159 has suspension points (not shown) formed thereon. The power assembly is coupled to the frame 11 by a suspension point and fastener fitting. In particular, the suspension points may be provided on the side of the outer housing assembly 159 that is closer to the generator 16, and the suspension points may also be provided on the side of the outer housing assembly 159 that is further from the generator 16. Further, the suspension points may also be provided as reserved connection locations on the outer housing assembly 159, thereby meeting the expansion applications of different platforms. Through the arrangement, the power assembly can be expanded on the vehicle types of different all-terrain vehicles 100, and the flexibility of the power assembly is improved.

As shown in fig. 4 and 5, the engine 15 further includes a cam mechanism 152, an intake and exhaust mechanism 153, an ignition mechanism 154, a piston mechanism (not shown), a timing system 155, a balancing mechanism 156, a cooling system 157, and a lubrication mechanism 158. The outer housing assembly 159 forms an accommodation space in which the cam mechanism 152, the intake and exhaust mechanism 153, the ignition mechanism 154, the piston mechanism, the timing system 155, the crankshaft connecting rod mechanism 151, the lubrication mechanism 158, the balance mechanism 156, and the cooling system 157 are at least partially disposed. Further, the accommodation spaces include a third accommodation space 1592a, a fourth accommodation space 1593a, and a fifth accommodation space 1594a.

As one implementation, the cylinder head 1592 is formed with a third accommodation space 1592a, and the cam mechanism 152, the intake and exhaust mechanism 153, the ignition mechanism 154, the timing system 155, the lubrication mechanism 158, and the cooling system 157 are at least partially disposed in the third accommodation space 1592 a. The cylinder block 1593 is formed with a fourth accommodation space 1593a, and the piston mechanism, the lubrication mechanism 158, the timing system 155, and the cooling system 157 are at least partially disposed in the fourth accommodation space 1593 a. The crankcase 1594 is formed with a fifth accommodation space 1594a, and the crank link mechanism 151, the lubrication mechanism 158, the balance mechanism 156, the timing system 155, and the cooling mechanism are at least partially disposed in the fifth accommodation space 1594 a.

The air intake and exhaust mechanism 153 includes an air intake mechanism 1531 and an exhaust mechanism 1534. The ignition mechanism 154 is disposed between the intake mechanism 1531 and the exhaust mechanism 1534. Along the axial direction of the ignition mechanism 154, one end of the ignition mechanism 154 is disposed near the cylinder block 1593, the other end of the ignition mechanism 154 is provided with a cam mechanism 152, the cam mechanism 152 includes a first cam shaft 1521 and a second cam shaft 1522, the first cam shaft 1521 is disposed near the intake mechanism 1531, and the second cam shaft 1522 is disposed near the exhaust mechanism 1534. The crankshaft connecting rod mechanism 151 includes a crankshaft 1511 and a connecting rod 1512, one end of the connecting rod 1512 is connected to the piston mechanism, and the other end of the connecting rod 1512 is connected to the crankshaft 1511. The crankshaft 1511 and the balance mechanism 156 are engaged by gears. When the piston mechanism makes a linear reciprocating motion in the cylinder block 1593, the piston mechanism drives the crankshaft 1511 to rotate through the connecting rod 1512, and drives the balance mechanism 156 to rotate through the rotation of the crankshaft 1511 to thereby reduce vibration when the engine 15 is operated. One end of the timing system 155 is connected to the cam mechanism 152, and the other end of the timing system 155 is connected to the crankshaft linkage 151. The lubrication mechanism 158 includes an oil pump 1581 and an oil return passage (not shown in the drawing), and the lubrication pump 1581 in an oil reservoir 1595a is sent to each component of the engine 15 through the oil pump 1581 and returns to the oil reservoir 1595a along the oil return passage. The cylinder block 1593 is formed with a cylinder bore 1593b penetrating itself for accommodating a piston mechanism, and the cooling system 157 is disposed at least partially around the cylinder bore 1593 b. The space between the ignition mechanism 154 and the cylinder block 1593 is a combustion chamber. The combustion chamber is set as the space between the top of the piston mechanism and the bottom surface of the cylinder head 1592 after the piston mechanism reaches the top dead center. Wherein top dead center is the position of the piston mechanism top furthest from the center of rotation of the crankshaft 1511. One end of the crankshaft 1511 is connected to the generator 16, and the generator 16 is driven to rotate by the crankshaft 1511 to supply electric power to the ATV 100, thereby driving the ATV 100 to travel.

As shown in fig. 6, the intake mechanism 1531 includes an intake manifold 1532 and a plurality of intake passages 1533, the intake manifold 1532 is connected to a cylinder head 1592, the intake manifold 1532 is for absorbing fresh air and distributing the fresh air to the different intake passages 1533, and the air flow distributed to the different intake passages 1533 can be made substantially the same by the intake manifold 1532, thereby improving the operation efficiency of the engine 15.

As shown in FIG. 7, as one implementation, engine 15 further includes a throttle mechanism (not shown) that cooperates with intake manifold 1532. The intake manifold 1532 includes a first cavity 1532a, a second cavity 1532b, and a first intake port 1532c. One end of the first air inlet 1532c is connected to the throttle mechanism, the other end of the first air inlet 1532c is connected to the first cavity 1532a, and the first air inlet 1532c communicates with the first cavity 1532a, and the first cavity 1532a communicates with the second cavity 1532b, so that air may enter the intake manifold 1532 along the first air inlet 1532c and circulate along the first cavity 1532a to the second cavity 1532b. In addition, a baffle 1532d is formed between the first cavity 1532a and the second cavity 1532b, and the baffle 1532d extends into a space where the first cavity 1532a and the second cavity 1532b are located, and the baffle 1532d and the intake manifold 1532 are integrally formed. When air enters the first cavity 1532a along the first air inlet 1532c, the flow rate of air flowing from the first cavity 1532a into the second cavity 1532b may be limited by the flow guide plate 1532 d.

As one implementation, the side of the baffle 1532d may be configured as a slope, the side of the baffle 1532d may be configured as a plane, and the side of the baffle 1532d may be configured as a cambered surface. Wherein, the side of the baffle 1532d refers to the surface of the baffle 1532d near the first cavity 1532a and/or near the second cavity 1532 b. Specifically, the side shape of the baffle 1532d may be set according to the actual situation. By providing the baffle 1532d between the first cavity 1532a and the second cavity 1532b, the air flow through the first cavity 1532a is increased, the air flow through the second cavity 1532b is reduced, and the air flow delivered into the different combustion chambers is substantially the same. Specifically, the height of the baffle 1532d in the direction perpendicular to the inner wall of the intake manifold 1532 is H. As one implementation, the height H of the baffle 1532d is 6.4mm or more and 9.6mm or less. Further, H is 7.2mm or more and 8.8mm or less. More specifically, H is equal to 8mm. With the above arrangement, at least a portion of the air is restricted from flowing into the second cavity 1532b along the first cavity 1532a, the air flow rate in the first cavity 1532a is increased, and the air flow rate in the second cavity 1532b is relatively reduced, thereby making the uniformity ε of the air flow rate in the first cavity 1532a ₁ 0 or more and 0.05 or less, and the air flow in the second cavity 1532bConsistency of the amounts epsilon ₂ 0 or more and 0.05 or less. Specifically, the uniformity ε of the air flow in the first cavity 1532a ₁ The following relationship is satisfied:uniformity epsilon of air flow in second cavity 1532b ₂ The following relationship is satisfied:wherein, the air flow rate of the first cavity 1532a is set to Q1, the air flow rate of the second cavity 1532b is set to Q2, and the average value of the air flow rate Q1 of the first cavity 1532a and the air flow rate Q2 of the second cavity 1532b is set to Q3.

As one implementation, the engine 15 includes a first line 103 that is substantially parallel to the direction of extension of the crankshaft 1511. The width of the baffle 1532D along the extending direction of the first straight line 103 is D1. As one implementation, the width D1 of the baffle 1532D is 12.8mm or more and 19.2mm or less. Further, the width D1 of the baffle 1532D is 14.4mm or more and 17.6mm or less. More specifically, the width D1 of the baffle 1532D is equal to 16mm. With the above arrangement, at least a portion of the air is restricted from flowing into the second cavity 1532b along the first cavity 1532a, the air flow rate in the first cavity 1532a is relatively increased, and the air flow rate in the second cavity 1532b is relatively decreased, so that the uniformity ε of the air flow rate in the first cavity 1532a is achieved ₁ 0 or more and 0.05 or less, and uniformity ε of air flow in the second cavity 1532b ₂ 0 or more and 0.05 or less.

As shown in fig. 7 and 8, the first cavity 1532a includes a first chamber 1532e and a second chamber 1532f, and the second cavity 1532b includes a third chamber 1532g and a fourth chamber 1532h. Further, one end of the second chamber 1532f communicates with the first chamber 1532e, and the other end of the second chamber 1532f communicates with at least part of the air inlet passage 1533; one end of the fourth chamber 1532h communicates with the third chamber 1532g, and the other end of the fourth chamber 1532h communicates with at least part of the intake passage 1533. Specifically, the first cavity 1532e and the third cavity 1532g are in communication, when emptyAs the air enters the first chamber 1532e along the first air inlet 1532c, at least a portion of the air flows into the third chamber 1532g along the first chamber 1532e and at least a portion of the air flows into the second chamber 1532f along the first chamber 1532 e. The junction of the first and second chambers 1532e and 1532f is formed with a first air inlet surface 1532m, and when air flows into the second chamber 1532f along the first chamber 1532e, the air flow rate depends on the size of the first air inlet surface 1532m, so that the air flow rate into the second chamber 1532f can be controlled by controlling the size of the first air inlet surface 1532 m. Further, the third chamber 1532g and the fourth chamber 1532h are communicated, and air sequentially passes along the first chamber 1532e to the third chamber 1532g, and enters the fourth chamber 1532h. Wherein, the second air inlet surface 1532n is formed at the connection of the third chamber 1532g and the fourth chamber 1532h, when air flows into the fourth chamber 1532h along the third chamber 1532g, the air flow rate depends on the size of the second air inlet surface 1532n, so that the air flow rate into the fourth chamber 1532h can be controlled by controlling the size of the second air inlet surface 1532 n. As one implementation, the area S1 of the first air inlet surface 1532m is 3920mm or more ² And less than or equal to 5880mm ² The area S2 of the second air inlet surface 1532n is 3120mm or more ² And less than or equal to 4680mm ² . Further, the area S1 of the first air inlet surface 1532m is 4410mm or more ² And less than or equal to 5390mm ² The area S2 of the second air inlet surface 1532n is 3510mm or more ² And less than or equal to 4290mm ² . More specifically, the area S1 of the first air inlet face 1532m is equal to 4900mm ² The area S2 of the second air inlet face 1532n is equal to 4290mm ² . By the above arrangement, the uniformity ε of the air flow in the first cavity 1532a is achieved ₁ 0 or more and 0.05 or less, and uniformity ε of air flow in the second cavity 1532b ₂ 0 or more and 0.05 or less.

As one implementation, the ratio of the area S1 of the first air intake surface 1532m to the area S2 of the second air intake surface 1532n is 1.04 or more and 1.56 or less. Further, the ratio of the area S1 of the first air intake surface 1532m to the area S2 of the second air intake surface 1532n is 1.17 or more and 1.43 or less. More specifically, the areas S1 and S1 of the first air inlet face 1532mThe ratio of the area S2 of the second air intake surface 1532n is equal to 1.43. By the above arrangement, the uniformity ε of the air flow in the first cavity 1532a is achieved ₁ 0 or more and 0.05 or less, and uniformity ε of air flow in the second cavity 1532b ₂ 0 or more and 0.05 or less. With the above arrangement, when air enters each combustion chamber along the intake manifold 1532, the air content in each combustion chamber is substantially uniform, which improves the combustion efficiency of the engine 15 when in operation, and avoids incomplete fuel combustion due to different air contents in each combustion chamber.

It will be appreciated that air entering the intake manifold 1532 from the first air inlet 1532c and flowing along the first cavity 1532a to the second cavity 1532b results in a greater air flow into the second cavity 1532b than into the first cavity 1532a, and that by providing the baffle 1532d, at least a portion of the air flow is restricted from flowing into the second cavity 1532 b. In addition, by providing the area S1 of the first air intake surface 1532m to be equal to or larger than the area S2 of the second air intake surface 1532n, the uniformity ε of the air flow in the first cavity 1532a is achieved ₁ 0 or more and 0.05 or less, and uniformity ε of air flow in the second cavity 1532b ₂ 0 or more and 0.05 or less. With the above arrangement, when air enters each combustion chamber along the intake manifold 1532, the air content in each combustion chamber is substantially uniform, which improves the combustion efficiency of the engine 15 when in operation, and avoids incomplete fuel combustion due to different air contents in each combustion chamber.

The intake mechanism 1531 is formed with a plurality of intake passages 1533, and when the intake manifold 1532 is connected to the cylinder head 1592, the first cavity 1532a communicates with at least a portion of the intake passages 1533, and the second cavity 1532b communicates with at least a portion of the intake passages 1533. As one implementation, the number of cavities of the intake manifold 1532 may be set to at least two, and the number of cavities of the intake manifold 1532 is the same as the number of intake passages 1533, so that the intake manifold 1532 is adapted to the multi-cylinder engine 15.

As shown in fig. 9, when the engine 15 is operated in a high temperature and high pressure operation state, the intake manifold 1532 provides the air required for combustion to the engine 15, the temperature in the intake manifold 1532 increases due to the operation of the engine 15, and the air flows into the intake passage 1533 along the intake manifold 1532, resulting in a decrease in the air pressure inside the intake manifold 1532. As an implementation manner, the intake manifold 1532 is provided with a sensing module 1532k, and the sensing module 1532k is configured to detect environmental parameters such as temperature, air pressure, and humidity in the first cavity 1532a and the second cavity 1532b, so as to timely maintain the interior of the engine 15, prevent the engine 15 from being damaged, and prolong the service life of the engine 15.

As one implementation, the intake manifold 1532 is further formed with a first receiving groove 1532j, the first receiving groove 1532j being at least partially disposed between the first cavity 1532a and the second cavity 1532b, the first receiving groove 1532j being in communication with the first cavity 1532a, and the first receiving groove 1532j being in communication with the second cavity 1532 b. The sensing module 1532k is at least partially disposed in the first receiving groove 1532j, and in particular, one end of the first receiving groove 1532j is formed with a first connection hole (not shown in the drawings), through which the sensing module 1532k passes, and is at least partially disposed in the first receiving groove 1532 j.

When the engine 15 is operated at a high temperature and a high pressure, a liquid accumulation is formed in the intake manifold 1532, and when the ATV 100 is traveling, the ATV 100 jolts due to uneven road surface, so that the liquid accumulation shakes in the intake manifold 1532. When the sensing module 1532k is at least partially disposed in the first accommodating groove 1532j, the arrangement direction of the sensing module 1532k may be adjusted according to the actual situation in order for the sensing module 1532k to operate normally. As one implementation, the first receiving groove 1532j may be disposed at an end of the intake manifold 1532 remote from the cylinder head 1592 when the intake manifold 1532 is connected to the cylinder head 1592. As shown in fig. 6, when the sensing module 1532k is disposed in the first accommodating groove 1532j, on a first projection plane 105 perpendicular to the first straight line 103, along the direction of the first straight line 103, the projection of the axis of the sensing module 1532k on the first projection plane 105 is a first projection line, the projection of the axis of the ignition mechanism 154 on the first projection plane 105 is a second projection line, and an included angle formed by the first projection line and the second projection line is a first included angle α. As one implementation manner, the first included angle α is greater than or equal to 0 ° and less than or equal to 72 °. Further, the first included angle α is 0 ° or more and 66 ° or less. More specifically, the first included angle α is 0 ° or more and 60 ° or less. Through the arrangement, the influence of the effusion in the intake manifold 1532 on the sensing module 1532k is avoided, the damage to the sensing module 1532k caused by the soaking of the effusion is prevented, and the service life of the sensing module 1532k is prolonged. Meanwhile, the first accommodating groove 1532j and the sensing module 1532k are arranged at one end of the intake manifold 1532 away from the cylinder cover 1592, so that the difficulty in disassembly and assembly of the sensing module 1532k is reduced, and the sensing module 1532k is convenient to overhaul and replace.

As another embodiment, the first accommodating groove 1532j may also be provided at an end of the intake manifold 1532 near the cylinder head 1592 when the intake manifold 1532 is connected to the cylinder head 1592. When the sensing module 1532k is disposed in the first accommodating groove 1532j, the axis of the sensing module 1532k is projected as a third projection line on the first projection plane 105 along the first straight line 103. The included angle formed by the second projection line and the third projection line is a second included angle beta. As one implementation, the second included angle β is equal to or greater than-72 ° and equal to or less than 0 °. Further, the second included angle β is-66 ° or more and 0 ° or less. More specifically, the second included angle β is equal to or greater than-60 ° and equal to or less than 0 °. Through the arrangement, the influence of the effusion in the intake manifold 1532 on the sensing module 1532k is avoided, the damage to the sensing module 1532k caused by the soaking of the effusion is prevented, and the service life of the sensing module 1532k is prolonged. Meanwhile, the first accommodating groove 1532j and the sensing module 1532k are disposed at the end of the intake manifold 1532 near the cylinder head 1592, reducing the effective space occupied by the engine 15 in the spatial arrangement of the all-terrain vehicle 100, providing convenience for the arrangement of the all-terrain vehicle 100.

It can be appreciated that the arrangement position of the first accommodating groove 1532j may be adjusted according to the actual situation, and the first accommodating groove 1532j may be disposed at one end far from the cylinder head 1592, so as to reduce the loading and unloading difficulty of the sensing module 1532 k; the first receiving groove 1532j may also be provided at an end adjacent to the cylinder head 1592 to reduce the effective space of the ATV 100 occupied by the intake manifold 1532 during assembly, providing convenience for assembly of other components of the engine 15. When the sensing module 1532k is disposed in the first accommodating groove 1532j, the sensing module 1532k is obliquely disposed, so as to avoid contact between the sensing module 1532k and the effusion, prevent the sensing module 1532k from being damaged, and enable the sensing module 1532k to detect temperature information and pressure information inside the intake manifold 1532. By the above arrangement, flexibility in arrangement of the engine 15 is promoted.

As shown in fig. 10 to 12, when the intake manifold 1532 is connected to the cylinder head 1592, in order to avoid leakage of fresh air and/or combustible mixture from the connection portion of the intake manifold 1532 and the cylinder head 1592, the intake manifold 1532 is provided with a first groove 1592b, a second groove 1592c and a seal 1596, thereby improving the sealability of the engine 15 as a whole. The first groove 1592b is provided on the intake manifold 1532, and the first groove 1592b is provided around an intake hole of one of the intake passages 1533 on the cylinder head 1592. The second groove 1592c is provided on the intake manifold 1532, and one end of the second groove 1592c communicates with the first groove 1592b, and the other end of the second groove 1592c penetrates the intake manifold 1532 and communicates to the outside. The seal 1596 is substantially rubber material to promote air tightness when the intake manifold 1532 is coupled to the cylinder head 1592. Other materials may be selected for the seal 1596 to promote air tightness of the engine 15. As one implementation, a plurality of first limiting protrusions (not shown) are disposed on the first groove 1592b, and when the sealing member 1596 is disposed on the first groove 1592b, the sealing member 1596 is pressed by the first limiting protrusions, so that the interaction force between the sealing member 1596 and the first groove 1592b is increased, and the firmness of the sealing member 1596 disposed in the first groove 1592b is improved, and the sealing member 1596 is prevented from falling off from the first groove 1592 b. As another implementation, a second limit protrusion 1596a is provided on the sealing member 1596, and when the sealing member 1596 is disposed in the first groove 1592b, the second limit protrusion 1596a presses the first groove 1592b, so that the interaction force between the sealing member 1596 and the first groove 1592b is increased, thereby improving the firmness of the sealing member 1596 disposed in the first groove 1592b and preventing the sealing member 1596 from falling out of the first groove 1592 b.

As shown in fig. 11 and 12, the seal 1596 is substantially annular in shape and the contour of the seal 1596 and the shape of the first groove 1592b are substantially identical. The seal 1596 has a stopper 1596b formed thereon. When the seal 1596 is disposed in the first recess 1592b, the limiter 1596b is at least partially disposed in the second recess 1592c, and at least a portion of the limiter 1596b extends along the second recess 1592c to the outside of the intake manifold 1532, the limiter 1596b being exposed outside the intake manifold 1532 by a length L1. As one implementation, the length L1 of the limiting portion 1596b exposed outside the intake manifold 1532 is 4mm or more and 12mm or less. Further, the length L1 of the stopper portion 1596b exposed outside the intake manifold 1532 is 4.5mm or more and 11mm or less. More specifically, the length L1 of the stopper portion 1596b exposed outside the intake manifold 1532 is 5mm or more and 10mm or less. With the above arrangement, the limit portion 1596b can serve as an obvious fitting mark to prevent the sealing member 1596 from being missed during the fitting process, and at least a portion of the limit portion 1596b is exposed outside the intake manifold 1532, and when the sealing member 1596 is removed by an inspection person, the limit portion 1596b exposed outside the cylinder head 1592 can be lifted and the sealing member 1596 can be taken out from the second recess 1592 c. Thereby reducing the difficulty of disassembly of the seal 1596 during disassembly.

As an implementation, when the number of the air intake passages 1533 is plural, the number of the first grooves 1592b and the number of the air intake passages 1533 are substantially the same, and the number of the seals 1596 and the number of the air intake passages 1533 are also substantially the same, thereby improving the air tightness of the engine 15 and preventing the leakage of the gas inside the engine 15. Specifically, the adjacent two sealing members 1596 may be connected to each other, and the adjacent two sealing members 1596 may be integrally formed with each other, so that the assembling time for assembling and disassembling the sealing members 1596 is reduced, and the problem that the sealing members 1596 are easy to miss-assemble during assembling is avoided. As another implementation, when the number of the air intake passages 1533 is plural, the number of the first grooves 1592b and the number of the air intake passages 1533 are substantially the same, and each of the seals 1596 may be separately provided in one of the first grooves 1592 b. By the above arrangement, economy of the seal 1596 is improved.

It will be appreciated that when the intake manifold 1532 is connected to the cylinder head 1592, by extending to the limit portion 1596b outside the cylinder head 1592, a service person can quickly find whether the seal 1596 is missing, improving convenience in checking whether the engine 15 is assembled.

As shown in FIG. 13, as one implementation, an air intake mechanism 1531 is used to deliver fresh air and/or combustible mixture into the combustion chamber to provide a source of power for operation of the engine 15. Intake mechanism 1531 also includes an intake passage 1533 and a fuel injection assembly (not shown). An intake passage 1533 is at least partially provided in the third accommodation space 1592a, and the intake passage 1533 is provided between the combustion chamber and the intake manifold 1532, with fuel and air being mixed in the intake passage 1533 to form a combustible mixture. The intake passage 1533 includes a first intake passage 1533a, a second intake passage 1533b, and a third intake passage 1533c. Wherein the first air intake passage 1533a and the second air intake passage 1533b are in communication, the first air intake passage 1533a and the third air intake passage 1533c are in communication, and the second air intake passage 1533b and the third air intake passage 1533c are provided as two branches of the first air intake passage 1533a, the second air intake passage 1533b and the third air intake passage 1533c are substantially identical in structure. Specifically, one end of the second air intake passage 1533b communicates with the first air intake passage 1533a, and the other end of the second air intake passage 1533b communicates with the combustion chamber; one end of the third air intake passage 1533c communicates with the first air intake passage 1533a, and the other end of the third air intake passage 1533c communicates with the combustion chamber. The first intake passage 1533a serves to collect air transmitted to the intake passage 1533 along the intake manifold 1532 and substantially uniformly distribute the air to the second intake passage 1533b and the third intake passage 1533c.

As one implementation, one end of the first intake passage 1533a is formed with a first oil injection hole 1533d and a second oil injection hole 1533e. The structure of the first oil jet 1533d and the structure of the second oil jet 1533e are substantially the same, and the first oil jet 1533d and the second oil jet 1533e are substantially circular. The distance between the center of the first oil spray hole 1533D and the center of the second oil spray hole 1533e is a first center distance D2, and the first center distance D2 is 25mm or more and 50mm or less. Further, the first circle center distance D2 is 33.3mm or more and 40.7mm or less. More specifically, the first centre of circle distance D2 is equal to 37mm. In the present embodiment, the fuel injection assembly includes a first fuel injection mechanism at least partially disposed in the first fuel injection hole 1533d and a second fuel injection mechanism at least partially disposed in the second fuel injection hole 1533e, and fuel is atomized by the fuel injection assembly to form a fuel bundle and injected into the intake passage 1533. The oil beam sprayed by the first oil spraying mechanism is mixed with air through a first air inlet channel 1533a to form combustible mixed gas, and the combustible mixed gas is conveyed to a combustion chamber along a second air inlet channel 1533 b; meanwhile, the oil bundle ejected from the second oil injection mechanism is mixed with air through the first air intake passage 1533a to form a combustible mixed gas, which is delivered to the combustion chamber along the third air intake passage 1533 c. Through the arrangement, the atomization effect of the fuel oil is improved, the accuracy of the coverage range of the fuel injection mechanism is improved, and the combustion efficiency of the combustible mixed gas is improved.

As shown in fig. 14, as one implementation, the second intake passage 1533b is formed with a second intake port 1533g near one end of the combustion chamber, and the third intake passage 1533c is formed with a third intake port 1533f near one end of the combustion chamber. The second air inlet 1533g and the third air inlet 1533f are substantially identical in structure, and the second air inlet 1533g and the third air inlet 1533f are substantially arranged in a circular shape. The distance between the second air inlet 1533g and the third air inlet 1533f is the second center of circle distance D3. Further, the first center distance D2 and the second center distance D3 are substantially equal. Thereby improving the coverage of the fuel in the intake passage 1533 and allowing the fuel and air to be sufficiently mixed.

The equivalent aperture of the second intake port 1533g is D4, and the length of the cylinder bore 1593b extending in the radial direction thereof is D5. In the present embodiment, the second air intake 1533g has a cross section approximately circular, and in order to better describe the correlation between the size of the second air intake 1533g and the size of the cylinder bore 1593b, the actual size of the second air intake 1533g is defined by the ratio relationship of the equivalent aperture D4 of the second air intake 1533g to the length D5 of the cylinder bore 1593 b. That is, the cross-sectional area of the second air inlet 1533g is defined as a circular area, and the equivalent aperture D4 of the second air inlet 1533g is calculated from the circular area. Wherein the equivalent pore diameter of the second air inlet 1533g satisfies the following relationship: Wherein the cross-sectional area of the second air inlet is set to a. As one implementation, the ratio of the equivalent aperture D4 of the second intake port 1533g to the length D5 of the cylinder bore is 0.33 or more and 0.47 or less. Further, the ratio of the equivalent aperture D4 of the second intake port 1533g to the length D5 of the cylinder bore is 0.35 or more and 0.44 or less. More specifically, the ratio of the equivalent aperture D4 of the second intake port 1533g to the length D5 of the cylinder bore is 0.37 or more and 0.42 or less. With the above arrangement, the coverage of the fuel in the intake passage 1533 is improved, so that the fuel and the air are sufficiently mixed.

It can be appreciated that by arranging the first oil injection hole 1533d and the second oil injection hole 1533e in the air intake passage 1533, and arranging the first oil injection mechanism at the first oil injection hole 1533d and the second oil injection mechanism at the second oil injection hole 1533e, the coverage of the oil injection beam of the oil injection assembly is improved, the air and the fuel are fully mixed, and the fuel economy and the combustion efficiency of the combustible mixed gas are improved.

As shown in fig. 15, as an implementation, a plurality of mounting holes 1592f for disposing the injection mechanism may also be provided on the cylinder head 1592. Specifically, the cylinder head 1592 is provided with a preset area 1592d, and the mounting hole 1592f is provided in the preset area 1592 d. The plurality of mounting holes 1592f together form a mounting area 1592e for receiving the injection mechanism, wherein the mounting area 1592e is at least partially disposed within the predetermined area 1592 d. Further, the structures among the plurality of mounting holes 1592f are substantially the same, the length of the mounting hole 1592f extending along the radial direction thereof is L2, and the length of the preset area 1592d extending along the first straight line 103 is L3. As one implementation, the ratio of the length L3 of the preset area 1592d to the length L2 of the mounting hole 1592f is 3.3 or more and 5 or less. Further, the ratio of the length L3 of the preset area 1592d to the length L2 of the mounting hole 1592f is 3.7 or more and 4.6 or less. More specifically, the ratio of the length L3 of the preset area 1592d to the length L2 of the mounting hole 1592f is equal to 4.1. Through the arrangement, the flexibility of the arrangement of the engine 15 is improved, and the cylinder cover 1592 can adapt to different specifications and different numbers of fuel injection assemblies under the condition of not changing the structure of the cylinder cover 1592.

As an implementation manner, on a second projection plane (not shown in the drawing) perpendicular to the mounting hole 1592f, a projection area of the mounting hole 1592f on the second projection plane along the own axis direction is S3, and a projection area of the preset area 1592d on the second projection plane along the axis direction of the mounting hole 1592f is S4. The ratio of the projected area S3 of the mounting hole 1592f to the projected area S4 of the preset area 1592d is 0.08 or more and 0.2 or less. Further, the ratio of the projected area S3 of the mounting hole 1592f to the projected area S4 of the preset area 1592d is 0.1 or more and 0.16 or less. More specifically, the ratio of the projected area S3 of the mounting hole 1592f to the projected area S4 of the preset area 1592d is equal to 0.13. Through the arrangement, the flexibility of the arrangement of the engine 15 is improved, and the cylinder cover 1592 can be adapted to fuel injection assemblies of different specifications under the condition of not changing the structure of the cylinder cover 1592.

In the present embodiment, the mounting area 1592e extends along the first straight line 103 by a length L4. As one implementation, the ratio of the length L4 of the mounting area 1592e to the length L3 of the preset area 1592d is greater than or equal to 0.81 and less than or equal to 1. Further, the ratio of the length L4 of the mounting area 1592e to the length L3 of the preset area 1592d is 0.86 or more and 0.96 or less. More specifically, the ratio of the length L4 of the mounting area 1592e to the length L3 of the preset area 1592d is equal to 0.91. Through the arrangement, the flexibility of the arrangement of the engine 15 is improved, so that the cylinder cover 1592 can be adapted to the arrangement form of the oil injection assembly of a single oil injection mechanism or the arrangement form of the oil injection assemblies of a plurality of oil injection mechanisms under the condition of not changing the structure of the cylinder cover 1592, and the engine 15 can be applied to all-terrain vehicles 100 or other vehicles in different forms.

In the present embodiment, the length of the preset area 1592d extending in the direction perpendicular to the first straight line 103 is the width L5 of the preset area 1592d, and the width direction of the preset area 1592d is parallel to the cross section of the mounting hole 1592 f. As one implementation, the ratio of the width L5 of the preset area 1592d to the length L3 of the preset area 1592d is greater than or equal to 0.27 and less than or equal to 0.42. Further, the ratio of the width L5 of the preset area 1592d to the length L3 of the preset area 1592d is 0.31 or more and 0.28 or less. More specifically, the ratio of the width L5 of the preset area 1592d to the length L3 of the preset area 1592d is equal to 0.34. Through the arrangement, the flexibility of the arrangement of the engine 15 is improved, and the cylinder cover 1592 can be adapted to fuel injection assemblies with different specifications and different arrangement modes under the condition of not changing the structure of the cylinder cover 1592.

As shown in fig. 15, the center distance between two adjacent mounting holes 1592f is L6. As one implementation, the ratio of the center distance L6 to the length L3 of the preset area 1592d is greater than or equal to 0.23 and less than or equal to 0.36. Further, the ratio of the center distance L6 to the length L3 of the preset area 1592d is 0.26 or more and 0.33 or less. More specifically, the ratio of the center distance L6 to the length L3 of the preset area 1592d is equal to 0.29. Through the arrangement, the flexibility of the arrangement of the engine 15 is improved, and the cylinder cover 1592 can be adapted to fuel injection assemblies with different specifications and different arrangement modes under the condition of not changing the structure of the cylinder cover 1592.

It will be appreciated that the mounting area 1592e may be machined from a predetermined area 1592d on the cylinder head 1592 for each case to provide a compatible arrangement of different fuel injection assemblies of the cylinder head 1592.

It will be understood that modifications and variations will be apparent to those skilled in the art from the foregoing description, and it is intended that all such modifications and variations be included within the scope of the following claims.

Claims

1. An all-terrain vehicle comprising:

a frame;

a body panel disposed at least partially on the frame;

the walking assembly is used for supporting the all-terrain vehicle;

a power assembly at least partially disposed on the frame, the power assembly comprising an engine and a generator;

it is characterized in that the method comprises the steps of,

the engine comprises an air inlet channel and an oil injection assembly; the air inlet channel is provided with a first oil injection hole and a second oil injection hole, the oil injection assembly is at least partially arranged in the first oil injection hole, and the oil injection assembly is also at least partially arranged in the second oil injection hole.

2. The ATV of claim 1, wherein the ATV comprises a frame,

the first distance D1 between the center of the first oil spraying hole and the center of the second oil spraying hole is more than or equal to 25mm and less than or equal to 50mm.

3. The ATV of claim 2, wherein the ATV comprises a frame,

the first distance D1 between the center of the first oil spraying hole and the center of the second oil spraying hole is more than or equal to 33.3mm and less than or equal to 40.7mm.

4. The ATV of claim 1, wherein the ATV comprises a frame,

the air inlet channel comprises a first air inlet channel, the oil injection assembly comprises a first oil injection mechanism and a second oil injection mechanism, the first oil injection mechanism is arranged in the first air inlet channel through the first oil injection hole, and the second oil injection mechanism is arranged in the first air inlet channel through the second oil injection hole.

5. The ATV of claim 4, wherein the vehicle is a car,

the engine further comprises a combustion chamber, and the air inlet channel further comprises a second air inlet channel and a third air inlet channel; one end of the second air inlet channel is connected to the combustion chamber, and the other end of the second air inlet channel is connected to the first air inlet channel; one end of the third air intake passage is connected to the combustion chamber, and the other end of the third air intake passage is connected to the first air intake passage.

6. The ATV of claim 5, wherein the vehicle is a car,

The second channel is close to one end of the combustion chamber and is provided with a first air inlet, the third channel is close to one end of the combustion chamber and is provided with a second air inlet, the distance between the centers of circles of the first air inlet and the second air inlet is a second distance D2, and the first distance D1 and the second distance D2 are basically consistent.

7. The ATV of claim 6, wherein the ATV comprises a frame,

the equivalent aperture of the first air inlet is D3, and the structure of the second air inlet is basically consistent with that of the first air inlet.

8. The ATV of claim 7, wherein the ATV comprises a frame,

the engine further comprises a cylinder hole for bearing high-temperature and high-pressure gas, wherein the aperture of the cylinder hole is D4; the ratio of the equivalent aperture D3 of the first intake port to the aperture D4 of the cylinder bore is 0.33 or more and 0.47 or less.

9. The ATV of claim 8, wherein the ATV comprises a frame,

the ratio of the equivalent aperture D3 of the first intake port to the aperture D4 of the cylinder bore is 0.35 or more and 0.44 or less.

10. The ATV of claim 9, wherein the ATV comprises a plurality of wheels,

the ratio of the equivalent aperture D3 of the first intake port to the aperture D4 of the cylinder bore is 0.37 or more and 0.42 or less.