Dual-clutch engine of a straddle-type vehicle

Abstract

The present invention relates to a dual-clutch engine for a straddle-type vehicle, comprising: a first clutch and a second clutch, which are arranged on the left and right sides of an engine housing; a main shaft, which includes a first input shaft and a second input shaft that are separated from each other and arranged coaxially, the first clutch is connected to a first side of the first input shaft, the second clutch is connected to a second side of the second input shaft, and the first input shaft and the second input shaft are integrally located between the first clutch and the second clutch. The above solution improves the layout of the first clutch, the second clutch and the gear shift gear pair, so as to facilitate troubleshooting.

Description

Technical Field

[0001] The present invention relates to the technical field of driving forces of cross-riding vehicles, and particularly to a dual-clutch engine for cross-riding vehicles. Background Art

[0002] At present, most of the motorcycle engines sold on the market adopt a single-clutch structure, and are equipped with a single shift drum to control a limited number of gears. When shifting gears in this way, there is a strong sense of jerk and the driving experience is not good.

[0003] Some also adopt dual-clutch engines. As disclosed in the prior art with the publication number of CN102297247B, there is a well-known dual-clutch transmission device as follows: a first clutch and a second clutch for cutting off or engaging the engine power are respectively arranged on a first input shaft (inner shaft) and a second input shaft (outer shaft) arranged coaxially. There are multiple gear sets for shifting between the first input shaft, the second input shaft and the output shaft. The first clutch and the second clutch are alternately cut off or engaged to achieve the shifting function.

[0004] For the above-mentioned single-sided combined dual-clutch engine, the first input shaft and the second input shaft are nested inside and outside and need to drive different gear sets for shifting to achieve the shifting function. The installation structure is complex. If a failure occurs, due to the complex installation structure, it is not convenient to troubleshoot the failure. Especially when one of the clutches fails, the entire engine housing needs to be disassembled for troubleshooting. And if parts need to be replaced, the two clutches, their corresponding main shafts and gears need to be completely disassembled and assembled. It is difficult to repair when a failure occurs and the repair cost is high.

[0005] In addition, in terms of the lubrication of the clutch, most of the motorcycle clutches sold on the market are dry clutches or wet clutches. Among them, when the dry clutch is in the semi-clutch state, the clutch disc friction is relatively serious. As a whole, its service life is shorter compared with the wet clutch; the wet clutch can be lubricated, but due to being immersed in the lubricating fluid for a long time, there is a certain degree of loss of the engine power. The above traditional clutch systems all have deficiencies. Summary of the Invention

[0006] In order to solve the above problems, the purpose of the present invention is to provide a dual-clutch engine for cross-riding vehicles, and improve the layout of the first clutch, the second clutch and the shift gear pair to facilitate troubleshooting.

[0007] The dual-clutch engine for cross-riding vehicles includes:

[0008] A first clutch and a second clutch for cutting off or combining the engine power, and the first clutch and the second clutch are arranged on the left and right sides of the engine case;

[0009] The main shaft includes a first input shaft and a second input shaft which are separated from each other and coaxially arranged. The first clutch is connected to the first side of the first input shaft, and the second clutch is connected to the second side of the second input shaft. The first input shaft and the second input shaft are integrally located between the first clutch and the second clutch;

[0010] The countershaft is arranged parallel to the main shaft. Shift gear pairs that cooperate with each other to form multiple different speed change gears are provided on the main shaft and the countershaft;

[0011] The first shift drum is driven by a first shift motor to drive a plurality of shift forks connected to the first shift drum to act to switch the engagement state of the odd - gear shift gear pairs;

[0012] The second shift drum is driven by a second shift motor to drive a plurality of shift forks connected to the second shift drum to act to switch the engagement state of the even - gear shift gear pairs.

[0013] Preferably, the output shaft of the first shift motor, the rotating shaft of the first shift drum, and the main shaft are arranged parallel to each other. The first shift drum is located on the side of the main shaft close to the first clutch. The first shift motor and the rotating shaft of the first shift drum are connected by a reduction gear set; the output shaft of the second shift motor, the second shift drum, and the main shaft are arranged parallel to each other. The second shift drum is located on the side of the main shaft close to the second clutch. The second shift motor and the rotating shaft of the second shift drum are connected by a reduction gear set; the connection end of the first shift drum and the reduction gear set is close to the first clutch, and the connection end of the second shift drum and the reduction gear set is close to the second clutch.

[0014] Preferably, a gear position sensor for detecting the currently engaged gear is provided between the first shift drum and the second shift drum.

[0015] Preferably, the gear position sensor includes a rotor and a housing. The rotor contains a magnet. The housing is installed between the first shift drum and the second shift drum. Two rotors are respectively installed on the rotating shafts of the first shift drum and the second shift drum and are arranged facing the housing. The rotation angles of the two shift drums are detected by the cooperation of the same housing and the two magnets.

[0016] Preferably, the engine housing includes a detachable first side cover and a second side cover. The first clutch is located inside the first side cover, and the second clutch is located inside the second side cover.

[0017] Preferably, the engine housing further includes a bottom shell, a first upper shell, and a second upper shell which are detachably connected to each other. The bottom shell is axially divided into a first half and a second half along the main shaft. The first input shaft and the odd - gear shift gear pairs are located in the installation space formed by the first half of the bottom shell and the first upper shell, and the second input shaft and the even - gear shift gear pairs are located in the installation space formed by the second half of the bottom shell and the second upper shell.

[0018] Preferably, there are at least two support plates corresponding to the first input shaft and the second input shaft on the engine housing, the at least two support plates are located at both ends of the first input shaft or the second input shaft in the axial direction, and bearings for installing the first input shaft or the second input shaft are provided thereon.

[0019] Preferably, it further includes: an injection pump and an ECU. Injection pumps are respectively arranged on the engine housing corresponding to the first clutch and the second clutch, and the injection nozzles of the injection pumps are aligned with the clutch disc clearances of the corresponding clutches; the ECU is used to control the corresponding injection pump to inject fuel into the clutch disc clearances of the clutch during the clutch operation.

[0020] Preferably, it includes a detection device for detecting whether the clutch is in the engaged state or the disengaged state. The detection device is connected to the ECU, and the ECU is used to control the injection pump corresponding to the clutch to inject fuel when the clutch is in the disengaged state.

[0021] Preferably, the injection nozzle of the injection pump is located directly above the corresponding clutch.

[0022] Due to the adoption of the above solution in the present invention, the first clutch and the second clutch are arranged on both sides of the engine housing. The main shaft is split into two independent first input shafts and second input shafts, which are arranged side by side in a straight line and separated from each other between the two clutches. The gear shifting gear pairs on the first input shaft and the second input shaft can be arranged regularly and orderly, so that the clutch and the gear shifting gear pairs do not need to be disassembled for convenient maintenance. In addition, the first clutch controls the odd-numbered gears, the second clutch controls the even-numbered gears, the first shift drum and the first shift motor cooperate with the first clutch to automatically realize the odd-numbered gear shift, and the second shift drum and the second shift motor cooperate with the second clutch to automatically realize the even-numbered gear shift, which can achieve seamless shifting; and by independently controlling the two shift drums with two shift motors, the two shift drums can act simultaneously, so that the shift clearance can be further shortened and the smoothness of shifting can be improved. Brief Description of the Drawings

[0023] Figure 1 It is a schematic installation structure diagram of the present application;

[0024] Figure 2 It is a schematic transmission diagram of the present application;

[0025] Figure 3 It is a schematic transmission structure diagram of the shift motor;

[0026] Figure 4 It is a schematic diagram of the installation position of the injection pump;

[0027] Figure 5 It is Figure 4 A schematic diagram of the structure after hiding part of the engine housing.

[0028] Reference Signs:

[0029] The first clutch 1, the second clutch 2, the first shift motor 031, the second shift motor 032, the reduction gear set 4, the first shift drum 5, the second shift drum 6, the shift fork shaft 7, the shift fork 8, the first input shaft 9, the second input shaft 10, the 6-speed drive gear 13, the 4-speed drive gear 14, the 8-speed drive gear 15, the 2-speed drive gear 16, the 7-speed drive gear 17, the 3-speed drive gear 18, the 5-speed drive gear 19, the 1-speed drive gear 20, the countershaft 21, the 1-speed driven gear 22, the 5-speed driven gear 23, the 3-speed driven gear 24, the 7-speed driven gear 25, the 2-speed driven gear 26, the 8-speed driven gear 27, the 4-speed driven gear 28, the 6-speed driven gear 29, the countershaft output gear 30, the output intermediate gear 31, the output shaft 33, the small sprocket 34, the gear position sensor 35, the rotor 351, the bottom case 41, the first side cover 42, the second side cover 43, the first upper case 44, the second upper case 45, the support plate 46, the bearing 47, the fuel injection pump 51, the fuel injector 52, and the fuel inlet pipe 53. Detailed Embodiment

[0030] The embodiments of the present invention will be described in detail below.

[0031] This embodiment discloses a dual-clutch engine for a straddle-type vehicle, including a first clutch 1 and a second clutch 2 for cutting off or engaging the engine power. Refer to Figure 1 and Figure 2 As shown, the first clutch 1 and the second clutch 2 are arranged on the left and right sides of the engine housing.

[0032] As Figure 2 shown, the dual-clutch engine includes: a main shaft composed of a first input shaft 9 and a second input shaft 10; a countershaft arranged in parallel with the main shaft; a shift gear pair arranged across the main shaft and the countershaft; the first clutch 1 and the second clutch 2 coaxially arranged at the left and right end portions of the main shaft; and a hydraulic supply device for supplying the hydraulic pressure for their operation to the first clutch 1 and the second clutch 2. The ECU cooperates with the hydraulic supply device to control the operation of the first clutch 1 and the second clutch 2.

[0033] Different from the dual-clutch engine in the prior art, the first input shaft 9 and the second input shaft 10 of the main shaft in this embodiment are separated from each other and coaxially arranged. The first clutch 1 is connected to the first side of the first input shaft 9, and the second clutch 2 is connected to the second side of the second input shaft 10. The first input shaft 9 and the second input shaft 10 are integrally located between the first clutch 1 and the second clutch 2. Specifically, the second input shaft 10 is located on the extension line of the first input shaft 9, and there is no inner and outer nesting relationship between the two. According to the switching of the engine power state by cutting off or engaging the first clutch 1 and the second clutch 2, the first clutch 1 drives the first input shaft 9 to rotate or the second clutch 2 drives the second input shaft 10 to rotate to achieve the power transmission of the engine. A plurality of driving gears 13-20 in the multiple gear shifting gear pairs are arranged on the first input shaft 9 and the second input shaft 10, and a plurality of driven gears 21-29 in the multiple gear shifting gear pairs are arranged on the countershaft. Each of the driving gears 13-20 and the driven gears 21-29 meshes with each other between the respective gear shifting positions, constituting a gear shifting gear pair corresponding to each gear shifting position.

[0034] In a specific embodiment, the dual-clutch engine realizes the gear shift of 1-n speeds, where n is an even number. Thus, the first clutch 1 is used to control the odd-numbered gears, and the second clutch 2 is used to control the even-numbered gears to shorten the shift gap. To achieve the above gear control, in this embodiment, the driving gears 17-20 for realizing the odd-numbered gear transmission ratios are arranged on the first input shaft 9, and the driving gears 13-16 for realizing the even-numbered gear transmission ratios are arranged on the second input shaft 10. Taking the dual-clutch engine realizing the gear shift of 1-8 speeds as an example, the driving gears 17-20 for realizing the transmission ratios of 1, 3, 5, and 7 speeds in the multiple gear shifting gear pairs are arranged on the first input shaft 9, and the driving gears 13-16 for realizing the transmission ratios of 2, 4, 6, and 8 speeds are arranged on the second input shaft 10.

[0035] The countershaft is arranged parallel to the main shaft, and the driven gears on it are arranged in one-to-one correspondence with the driving gears. The control of upshifting and downshifting by the clutch is achieved by switching the gear pairs for the corresponding gears. Briefly, among the driving gear and the driven gear of the gear pair for shifting gears, there are a free gear and a spline gear. The free gear can rotate freely relative to the input shaft, and the free gear cannot directly transmit the rotation to the input shaft. The spline gear can directly transmit the power to the input shaft, and the spline gear can slide left and right along the axial direction of the input shaft. After the spline gear is connected to the free gear, the power can be transmitted according to the transmission ratio of the free gear to achieve gear shifting. The structure and principle of the cooperation between the driving gear and the driven gear to achieve gear shifting are conventional technical means in the art and will not be described in detail here. The main improvement of the present invention lies in the layout of the first clutch 1, the second clutch 2, the first input shaft 9, the second input shaft 10, and the gear pairs for shifting gears. Through the above arrangement, the gear pairs for shifting gears of each gear are arranged orderly and regularly between the two clutches, and the main shaft parts controlled by the two clutches and the gear pairs for shifting gears are separated from each other, which is convenient for inspection and maintenance. Specifically, as Figure 1 shown, the first clutch 1 and the second clutch 2 are configured in the engine housing as follows: the first clutch 1 for odd-numbered gears, the first input shaft 9, and the odd-numbered driving gears are integrally arranged in the left half of the engine housing, and the second clutch 2 for even-numbered gears, the second input shaft 10, and the even-numbered driving gears are integrally arranged in the right half of the engine housing.

[0036] Combined with Figure 2 and Figure 3, the dual-clutch engine includes an automatic shifting mechanism. The automatic shifting mechanism includes a first shifting drum 5 driven by a first shifting motor 031 to drive several shifting forks 8 connected to the first shifting drum 5 to actuate and switch the engagement state of the odd-gear shifting gear pair; a second shifting drum 6 driven by a second shifting motor 032 to drive several shifting forks 8 connected to the second shifting drum 6 to actuate and switch the engagement state of the even-gear shifting gear pair. Among them, the first shifting motor 031 and the second shifting motor 032 are controlled by the ECU to achieve automatic shifting. One end of the shifting fork 8 is slidably connected to the slideway on the outer periphery of the shifting drum, and the other end of the shifting fork 8 is adjacent to the spline gear in the shifting gear pair. When the shifting drum rotates, the connected shifting fork 8 moves along its slideway, and through the shape setting of the slideway, the shifting fork 8 drives the adjacent spline gear to move left and right axially to change the access state between the spline gear and the adjacent sliding gear, thereby realizing gear shifting. In this embodiment, the first shifting drum 5 and the second shifting drum 6 are respectively connected to several shifting forks 8 to access the shifting gear sets with different transmission ratios. In the above solution of the present application, the first shifting drum 5 and the first shifting motor 031 cooperate with the first clutch 1 to automatically achieve odd-gear shifting, and the second shifting drum 6 and the second shifting motor 032 cooperate with the second clutch 2 to automatically achieve even-gear shifting, which can achieve seamless shifting; and by independently controlling the two shifting drums with two shifting motors, the two shifting drums can act simultaneously, thereby further shortening the shifting gap and improving the smoothness of shifting.

[0037] A countershaft output gear 30 is provided on the countershaft and rotates synchronously with the countershaft. The countershaft output gear 30 transmits the power transmission value to the output shaft 33 through an output intermediate gear 31, and drives the small sprocket 34 thereon to rotate through the output shaft 33 to achieve power output.

[0038] The following further illustrates the shifting operation of the dual-clutch engine of the cross-riding vehicle by taking an 8-speed shift as an example.

[0039] After the engine is started, the crankshaft drive gear drives the first clutch 1 and the second clutch 2 on both sides to rotate. The clutch and disengagement state of the electronically controlled clutch determines whether the clutch gears on both sides drive the first input shaft 9 and the second input shaft 10 to rotate. As Figure 1 shown, the left red arrow in the figure represents the power transmission path of the first gear, and the right green arrow represents the power transmission path of the second gear. The following describes the shifting operation process in combination with two examples.

[0040] Example 1: When starting from the N gear and shifting up to the 1st gear, first, the first clutch 1 is switched to the disengaged state by an external actuating mechanism. The motorcycle ECU processes the upshift signal and sends an upshift power-on signal to the first shift motor 031. The first shift motor 031 operates to drive the first shift drum 5 to rotate, causing the shift fork to slide to the left. The shift fork forces the drive pin on the left side of the 5th-speed driven gear 23 on the countershaft to engage with the 1st-speed driven gear 22, enabling the 1st-speed driven gear 22 to rotate synchronously with the countershaft 21. Immediately afterwards, the first clutch 1 is engaged. At this time, the engine power transmission sequence is: engine crankshaft → clutch left gear → first clutch 1 → first input shaft → 1st-speed driving gear 20 → 1st-speed driven gear 22 → engine countershaft 21 → countershaft output gear 30 → output transition gear 31 → output shaft drive gear → output shaft 33 → small sprocket 34.

[0041] Example 2: When shifting to the 2nd gear, the second clutch 2 is switched to the disengaged state by an external actuating mechanism. The motorcycle ECU processes the upshift signal and sends an upshift power-on signal to the second shift motor 032. The second shift motor 032 drives the second shift drum 6 to rotate, causing the shift fork 8 to move the 8th-speed driving gear 15, and its left drive pin engages with the 2nd-speed driving gear 16. Then, the first clutch 1 is switched to the disengaged state, and the second clutch 2 is switched to the engaged state. At this time, the engine power transmission sequence is: engine crankshaft → clutch right gear → second clutch 2 → second input shaft → 2nd-speed driving gear 16 → 2nd-speed driven gear 26 → engine countershaft 21 → countershaft output gear 30 → output transition gear 31 → output shaft drive gear → output shaft 33 → small sprocket 34.

[0042] As Figure 2 shown, in order to simplify the installation structure of the shift fork 8, in this embodiment, a shift fork shaft 7 parallel to the main shaft and the countershaft is provided between the two clutches. All the shift forks 8 are commonly installed on this shift fork shaft 7. The shift fork 8 can rotate relative to the shift fork shaft 7. Thus, when the shift drum drives several other shift forks 8 to rotate around the shift fork shaft 7, the remaining shift forks 8 can remain in their current positions.

[0043] As Figure 2As shown, in this embodiment, the output shaft 33 of the first shift motor 031, the rotating shaft of the first shift drum 5, and the main shaft are arranged in parallel with each other, the first shift drum 5 is located on the side of the main shaft close to the first clutch 1, and the first shift motor 031 and the rotating shaft of the first shift drum 5 are connected by a reduction gear set 4; the output shaft 33 of the second shift motor 032, the second shift drum 6, and the main shaft are arranged in parallel with each other, the second shift drum 6 is located on the side of the main shaft close to the second clutch 2, and the second shift motor 032 and the rotating shaft of the second shift drum 6 are connected by a reduction gear set 4, the connection end of the first shift drum 5 and the reduction gear set 4 is close to the first clutch 1, and the connection end of the second shift drum and the reduction gear set 4 is close to the second clutch 2. In this way, the two shift motors and the shift drums are arranged side by side and located between the two clutches, the automatic shift mechanism is located on one side of the shift gear pair as a whole, and the reduction gear set 4 is arranged close to the clutch, and the installation structure is compact.

[0044] In order to realize the speed control of the ECU, it is necessary to detect the current gear position. Therefore, in this embodiment, a gear position sensor 35 for detecting the current gear position is provided between the first gear shift drum 5 and the second gear shift drum 6. The current gear position is obtained by detecting the positions of the first gear shift drum 5 and the second gear shift drum 6. The gear position sensor 35 is arranged in this way, and no additional installation space is required. The gear position sensor 35 in this embodiment includes a rotor 351 and a housing. The rotor 351 includes a magnet. The housing is installed between the first gear shift drum 5 and the second gear shift drum 6. The two rotors 351 are respectively installed on the rotating shafts of the first gear shift drum 5 and the second gear shift drum 6 and are arranged toward the housing. The rotation angles of the two gear shift drums are detected by cooperating with the same housing and the two rotors. The above arrangement detects the rotation angles of the rotating shafts of the two gear shift drums through the same housing, and uses the same gear position sensor 35 to detect the gear shift drums on both sides, and the detection results are highly consistent.

[0045] The left and right sides of the engine housing are detachably connected with a first side cover 42 and a second side cover 43, which serve as clutch covers. The first side cover 42 is provided with a first clutch 1, and the second side cover 43 is provided with a second clutch 2. Figure 1, the first side cover 42 and the second side cover 43 are respectively fixed in a detachable manner by a plurality of bolts, which is convenient for overhauling the clutch. The engine housing further includes a bottom shell 41, a first upper shell 44 and a second upper shell 45 that are detachably connected to each other. The bottom shell 41 is axially divided into a first half and a second half along the main shaft. The first input shaft 9 and the odd-gear shift gear pair are located in the installation space formed by the first half of the bottom shell 41 and the first upper shell 44. The second input shaft 10 and the even-gear shift gear pair are located in the installation space formed by the second half of the bottom shell 41 and the second upper shell 45. With such a setting, one or more of the first side cover 42, the second side cover 43, the first upper shell 44 and the second upper shell 45 can be opened according to the specific clutch and the specific shift gear pair to be overhauled. Corresponding to the first input shaft 9 and the second input shaft 10, at least two support plates 46 are respectively provided on the engine housing. The at least two support plates 46 are located at both ends in the axial direction of the first input shaft 9 or the second input shaft 10, and bearings 47 for installing the first input shaft 9 or the second input shaft 10 are provided thereon. Thus, the first input shaft 9 and the second input shaft 10 are respectively installed by the cooperation of two support plates 46 and two bearings 47. In this embodiment, taking the installation of the first input shaft 9 as an example, support plates 46 are respectively provided at both ends of the left half of the housing close to the first input shaft 9. In an alternative embodiment, the support plate 46 is detachably installed in the engine housing by a plurality of bolts; in another alternative embodiment, the support plate 46 is integrally formed in the engine housing. Further optionally, a part of one support plate 46 is provided on the bottom shell 41, and the other part is provided on the first upper shell 44. After the first upper shell 44 and the bottom shell 41 are installed, the support plates 46 on the bottom shell 41 and the first upper shell 44 are assembled into a complete support plate 46. Both ends of the first input shaft 9 are installed on the support plate 46 through bearings 47. For the installation of the second input shaft 10, refer to the first input shaft 9.

[0046] In this embodiment, the first clutch 1 and the second clutch 2 are electro-controlled clutches, and are hydraulic clutches that cut off or connect the engine power by hydraulically controlling the axially displacement of the pressure plate. As Figure 4 and Figure 5, the dual-clutch engine of this embodiment further includes a fuel injection pump 51. The fuel injection pumps 51 are respectively arranged on the engine housing corresponding to the first clutch 1 and the second clutch 2, and the fuel injection nozzles 52 of the fuel injection pumps 51 are aligned with the clutch disc clearances of the corresponding clutches; the ECU is used to control the corresponding fuel injection pump 51 to inject fuel into the clutch disc clearances of the clutch during the clutch operation. During the clutch actuation, the fuel injection pump 51 causes the lubricating oil to be sprayed into the clutch disc clearances in the clutch through the fuel injection nozzles 52, so that the clutch discs can be fully lubricated before engagement, and the heat generated by the friction of the clutch discs can be transferred to the lubricating oil to the greatest extent, extending the service life of the clutch friction discs; and compared with the wet clutch in the prior art, there is no need to partially immerse it in the lubricating oil, and there can be less power loss. Thus, the fuel injection pump 51 arranged as above combines the advantages of a dry clutch and a wet clutch, ensuring both a high power transmission efficiency and the long service life characteristics of a wet clutch. The fuel injection pump 51 in this embodiment is an electronic fuel injection pump 51, and whether to inject fuel is controlled by the ECU. The bottom of the engine housing is an oil pan 41 for storing the recycled engine oil. The inlet of the fuel injection pump 51 is connected to the oil pan 41 through an inlet pipe 53 to draw out the engine oil in the oil pan 41 for use as the lubricating oil of the clutch. The outlet of the fuel injection nozzle 52 of the fuel injection pump 51 is located in the engine housing and is aligned with the clutch disc clearances of the corresponding clutch, so that the filtered lubricating oil enters the fuel injection pump 51 from the inlet pipe 53 of the fuel injection pump 51 and enters the clutch disc clearances through the fuel injection nozzles 52, and the fuel injection pump 51 can apply lubricating oil to the corresponding clutch.

[0047] In specific use, the fuel injection pump 51 is detachably fixed on the engine housing. The fuel injection pump 51 and the inlet pipe 53 are located outside the engine housing, and the engine housing is provided with an opening for the fuel injection nozzle 52 of the fuel injection pump 51 to extend into. With this arrangement, the fuel injection pump 51 and the inlet pipe 53 are external, without occupying the space inside the engine housing, which is convenient for maintenance. Only a structure for fixing the fuel injection pump 51 needs to be provided on the engine housing. In a specific embodiment, according to the structure of the fuel injection pump 51 used, the structure for fixing the fuel injection pump 51 on the engine housing is set. For example, the engine housing is provided with a fixing seat matching the shape of the pump body of the fuel injection pump 51, or the fuel injection pump 51 is provided with a threaded connection portion, and the engine housing is provided with a corresponding threaded connection hole.

[0048] In a preferred embodiment, the fuel injection nozzles 52 of the fuel injection pump 51 are located directly above the corresponding first clutch 1 and second clutch 2. Thus, the lubricating oil sprayed out through the fuel injection nozzles 52 enters the clutch disc clearances from directly above, and the coverage rate of the lubricating oil is relatively higher.

[0049] The above-mentioned embodiment structure of the present invention improves the layout of the first clutch 1 and the second clutch 2, and improves the setting method of the fuel injection pump 51 of the clutch, having the characteristics of being convenient for maintenance and combining the advantages of dry clutches and wet clutches.

[0050] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the claims and their equivalents.

Claims

1. Dual-clutch engine for a straddle-type vehicle, characterized in that, include: The first clutch and the second clutch for cutting off or connecting the engine power are arranged on the left and right sides of the engine housing; after the engine is started, the crankshaft transmission gear drives the first clutch and the second clutch on both sides to rotate; The main shaft includes a first input shaft and a second input shaft that are separated from each other and coaxially arranged, the first clutch is connected to a first side of the first input shaft, the second clutch is connected to a second side of the second input shaft, and the first input shaft and the second input shaft are integrally located between the first clutch and the second clutch; The countershaft is arranged parallel to the main shaft, and the main shaft and the countershaft are provided with gear pairs that cooperate with each other to form a plurality of different gear shift positions; A first shift drum, driven by a first shift motor, drives a plurality of shift forks connected to the first shift drum to switch the engagement state of the odd-numbered shift gear pairs; A second shift drum is driven by a second shift motor to drive a plurality of shift forks connected to the second shift drum to switch the engagement state of the even-numbered shift gear pairs; Also includes: A fuel injection pump is provided on the engine housing corresponding to the first clutch and the second clutch, and the fuel injection nozzle of the fuel injection pump is aligned with the clutch plate gap of the corresponding clutch; the fuel injection pump is an electronic fuel injection pump, and whether to inject fuel is controlled by the ECU; the fuel injection nozzle of the fuel injection pump is located outside the corresponding clutch; ECU, used to control the corresponding fuel injection pump to inject fuel into the clutch plate gap of the clutch during clutch action; The detection device is used to detect whether the clutch is in an engaged state or a disengaged state. The detection device is connected to the ECU, and the ECU is used to control the fuel injection pump corresponding to the clutch to inject fuel when the clutch is in a disengaged state.

2. The dual clutch engine of the straddle-type vehicle according to claim 1, characterized in that, The output shaft of the first shift motor, the rotating shaft of the first shift drum, and the main shaft are arranged parallel to each other, the first shift drum is located on the side of the main shaft close to the first clutch, and the first shift motor and the rotating shaft of the first shift drum are connected by a reduction gear set; the output shaft of the second shift motor, the second shift drum, and the main shaft are arranged parallel to each other, the second shift drum is located on the side of the main shaft close to the second clutch, and the second shift motor and the rotating shaft of the second shift drum are connected by a reduction gear set; the connecting end of the first shift drum and the reduction gear set is close to the first clutch, and the connecting end of the second shift drum and the reduction gear set is close to the second clutch.

3. The dual clutch engine of the straddle-type vehicle according to claim 2, characterized in that, A gear position sensor for detecting the current gear position is arranged between the first gear shift drum and the second gear shift drum.

4. The dual clutch engine of a straddle-type vehicle according to claim 3, wherein The gear position sensor includes a rotor and a shell. The rotor contains a magnet. The shell is installed between the first gear shift drum and the second gear shift drum. The two rotors are respectively installed on the rotating shafts of the first gear shift drum and the second gear shift drum and are arranged toward the shell. The rotation angles of the two gear shift drums are detected by cooperating with the two magnets through the same shell.

5. The dual clutch engine of a straddle-type vehicle according to claim 1, characterized in that, The engine case comprises a detachable first side cover and a detachable second side cover. The first clutch is located in the first side cover, and the second clutch is located in the second side cover.

6. The dual clutch engine of a straddle-type vehicle according to claim 5, characterized in that, The engine housing further includes a bottom shell, a first upper shell, and a second upper shell that are detachably connected to each other. The bottom shell is axially divided into a first half and a second half along the main shaft. The first input shaft and the odd-gear shift gear pair are located in the installation space formed by the first half of the bottom shell and the first upper shell. The second input shaft and the even-gear shift gear pair are located in the installation space formed by the second half of the bottom shell and the second upper shell.

7. The dual clutch engine of a straddle-type vehicle according to claim 1, characterized in that, The engine housing is respectively provided with at least two support plates corresponding to the first input shaft and the second input shaft. The at least two support plates are located at both ends of the first input shaft or the second input shaft in the axial direction, and bearings for installing the first input shaft or the second input shaft are provided thereon.

8. The dual clutch engine of the straddle-type vehicle according to claim 1, characterized in that, The fuel injector of the fuel injection pump is located directly above the corresponding clutch.

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