Double-clutch transmission gear shifting hub structure and double-clutch transmission

Abstract

This application relates to a dual-clutch transmission shift hub structure and a dual-clutch transmission, comprising: a shift hub body, on the outer circumference of which are formed an R-gear shift groove, a forward shift groove, and an auxiliary shift groove; wherein, the final rotation angle value of the shift angle range threshold of the R-gear shift groove is the same as the initial rotation angle value of the shift angle range threshold of the forward shift groove; the shift angle range threshold of the auxiliary shift groove partially overlaps with the shift angle range threshold of the R-gear shift groove and the shift angle range threshold of the forward shift groove. In this application, during the process of shifting from reverse to forward gear in the dual-clutch transmission, before the reverse gear and reverse synchronizer disengage, the auxiliary shift groove drives a shift fork to drive the synchronizer ring of a forward synchronizer to slide and rub against a forward gear, thereby reducing the rotational speed of the input shaft connected to the clutch and reducing static shift noise.

Description

Technical Field

[0001] This application relates to the field of dual-clutch transmission technology, and in particular to a dual-clutch transmission shift hub structure and a dual-clutch transmission. Background Technology

[0002] The application prospects of transmissions in passenger vehicles are broad, and with the advancement of various high-performance powertrain technologies, automatic transmission technology is also developing rapidly. Dual-clutch transmissions (DCTs) have become one of the most widely used automatic transmission structures in automotive powertrains.

[0003] The shift hub is a core component of the DCT transmission, combining the structural features of various types of parts such as thin-walled cavities, shafts, and spatial curved surfaces. Aluminum material has a large thermal deformation coefficient and is easily deformed. The structural design and manufacturing quality of the shift hub directly determine the efficiency and smoothness of gear shifting.

[0004] The shift hub has a spatial groove profile, and the shape of the profile directly determines the trajectory of the shift fork. Since the shift fork controls the movement of the synchronizer sleeve, most shift noise is generated during the movement of the synchronizer sleeve. Therefore, the design of the shift hub profile plays a crucial role in reducing shift noise.

[0005] Shift noise reflects the shift quality of a transmission, and this standard is a crucial factor in determining the overall NVH performance of a vehicle. To reduce static shift noise and improve shift efficiency, most existing dual-clutch transmissions employ a dual-shift hub structure. However, for low-torque products or those requiring lightweight and compact designs, the dual-shift hub structure offers no advantage.

[0006] In related technologies, most current research on shift noise in dual-clutch transmissions focuses on dynamic shifting, primarily optimizing shift positions and points. However, research and optimization on static shifting are virtually nonexistent. Static shift noise occurs when the vehicle is stationary and the gear lever is manually operated to shift from R to D. This is especially true for transmissions with a single shift drum, where the inherent structural limitations prevent the complete elimination of static shift noise.

[0007] Currently, most dual-clutch transmissions use a single-line control strategy for their shift hub profiles. Strictly speaking...

[0008] Rotating the shift hub at any given time can only change the trajectory of a single shift fork, and cannot drive multiple shift forks to operate simultaneously, thus failing to improve its shifting performance.

[0009] In a dual-clutch transmission, two clutches control odd-numbered and even-numbered gears respectively. During dynamic shifting, the two clutches interact to ensure continuous shifting. Due to the dual-clutch control strategy, the synchronizer is already engaged before the gear shifts, so there are essentially no neutral gears in the transmission. At least one gear is always engaged with the final drive, thus preventing clutch drag torque from causing speed fluctuations.

[0010] Static shifting differs significantly from dynamic shifting. When the vehicle is stationary or in Park (P), the 2nd / 4th gear synchronizers are in the 2nd gear position, the Axle synchronizers are in the Axle position, and the reverse and 3rd / 5th gear synchronizers are in neutral. When the driver needs to shift between Reverse (R) and Drive (D), the synchronizers must first disengage from a specific gear. For example, to disengage from Reverse and enter Drive, the Reverse synchronizer must disengage.

[0011] However, when disengaging to the synchronizer neutral position, the entire gearbox gear system will be in a gearless state. Due to the drag torque of the wet clutch, the entire transmission system will generate a large speed instantaneously. However, in the next stage, the 2 / 4 synchronizer will engage second gear. Due to the large speed difference between the two ends of the synchronizer, the synchronizer bevel teeth will collide and generate obvious noise. Summary of the Invention

[0012] This application provides a dual-clutch transmission shift hub structure and a dual-clutch transmission to solve the problem in related technologies where the entire transmission system generates a large instantaneous speed during the switching between reverse and forward gears in a wet dual-clutch transmission, resulting in significant noise caused by the collision of synchronizer bevel teeth.

[0013] The first aspect of this application provides a dual-clutch transmission shift hub structure, including:

[0014] The shift hub body has an R gear shift groove, a forward gear shift groove and an auxiliary shift groove on its outer circumferential surface.

[0015] The final rotation angle value of the R gear shift slide angle range threshold is the same as the initial rotation angle value of the forward gear shift slide angle range threshold.

[0016] The shift angle range threshold of the auxiliary shift slide groove partially overlaps with the shift angle range threshold of the R shift slide groove and the shift angle range threshold of the forward shift slide groove.

[0017] In some embodiments: the forward gear shifting slide includes a 2 / 4 gear shifting slide and a 3 / 5 gear shifting slide, and the shifting angle range threshold of the auxiliary shifting slide coincides with the rotation angle range threshold of the last segment of the R gear shifting slide and the rotation angle range threshold of the first segment of the 2 / 4 gear shifting slide.

[0018] In some embodiments: the auxiliary shift slide and the 3 / 5 gear shift slide are on the same slide, and the shift angle range threshold of the auxiliary shift slide is less than the shift angle range threshold of the 3 / 5 gear shift slide;

[0019] The shift angle range threshold of the auxiliary shift slide is less than the travel of the shift angle range threshold of the 3 / 5 gear shift slide in the direction of the shift hub axis.

[0020] In some embodiments: the shift angle range threshold of the R gear shift slide is 14.4 to 41.5 degrees, the shift angle range threshold of the 2 / 4 gear shift slide is 41.5 to 68.6 degrees, and the shift angle range threshold of the auxiliary shift slide is 20.5 to 62.5 degrees.

[0021] In some embodiments, the final rotation angle value of the R gear shift slide angle range threshold and the initial rotation angle value of the forward gear shift slide angle range threshold are both 41.5 degrees.

[0022] In some embodiments, the shift hub body is further included with a planetary gear mechanism located within the shift hub body. The input end of the planetary gear mechanism is connected to a motor that drives the planetary gear mechanism. The motor drives the shift hub body to reciprocate within the range of 0 to 200.8 degrees through the planetary gear mechanism.

[0023] A second aspect of this application provides a dual-clutch transmission, comprising:

[0024] A gearbox housing, wherein the dual-clutch gearbox shift hub structure described in any of the above embodiments is installed within the gearbox housing.

[0025] In some embodiments: the gearbox housing is further provided with a reverse synchronizer for engaging the reverse gear and the sixth gear, a 2 / 4 gear synchronizer for engaging the second gear and the fourth gear, and an auxiliary synchronizer for engaging the third gear and the fifth gear;

[0026] The reverse gear fork that moves the reverse gear synchronizer is slidably connected in the R gear shift groove of the shift hub. The 2 / 4 gear shift fork that moves the 2 / 4 gear synchronizer is slidably connected in the 2 / 4 gear shift groove of the shift hub. The 3 / 5 gear shift fork that moves the 3 / 5 gear synchronizer is slidably connected in the auxiliary shift groove of the shift hub.

[0027] In some embodiments, the gearbox housing is further provided with a first clutch and a second clutch. The first clutch is connected to the third gear and the fifth gear via a first input shaft, and the second clutch is connected to the second gear, the fourth gear and the sixth gear via a second input shaft.

[0028] In some embodiments: before the reverse gear fork disengages the reverse gear synchronizer from the reverse gear, the 3 / 5 gear fork engages the synchronizing ring of the 3 / 5 gear synchronizer in a frictional sliding connection with the third or fifth gear to reduce the speed of the first input shaft;

[0029] When the 2 / 4 gear shift fork engages the 2 / 4 gear synchronizer with the second or fourth gear, the 3 / 5 gear shift fork disengages the synchronizing ring of the 3 / 5 gear synchronizer from the third or fifth gear to the neutral position.

[0030] The beneficial effects of the technical solution provided in this application include:

[0031] This application provides a dual-clutch transmission shift hub structure and a dual-clutch transmission. The dual-clutch transmission shift hub structure includes a shift hub body with an R-gear shift groove, a forward shift groove, and an auxiliary shift groove on its outer circumferential surface. The final rotation angle value of the shift angle range threshold of the R-gear shift groove is the same as the initial rotation angle value of the shift angle range threshold of the forward shift groove. The shift angle range threshold of the auxiliary shift groove partially overlaps with the shift angle range threshold of the R-gear shift groove and the shift angle range threshold of the forward shift groove.

[0032] Therefore, the dual-clutch transmission shift hub structure of this application adds an auxiliary shift groove to the outer circumference of the original shift hub body. The shift angle range threshold of this auxiliary shift groove partially overlaps with the shift angle range threshold of the R shift groove and the shift angle range threshold of the forward shift groove. During the process of shifting from reverse to forward gear in the dual-clutch transmission, before the reverse gear and reverse synchronizer disengage, the auxiliary shift groove drives a shift fork to drive the synchronizer ring of a forward gear synchronizer to slide and rub against a forward gear, thereby reducing the speed of the input shaft connected to the clutch. Ultimately, this reduces the speed difference between the forward synchronizer and the forward gear that need to mesh, which can be controlled between 6.9-13.5 rpm, far below the theoretical synchronization speed difference value of the synchronizer, greatly improving static shifting efficiency and reducing static shifting noise. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1This is a schematic diagram of the dual-clutch transmission shift hub structure according to an embodiment of this application;

[0035] Figure 2 This is a schematic diagram of the shift hub groove profile of the shift hub body according to an embodiment of this application;

[0036] Figure 3 This is a schematic diagram of the structure of a dual-clutch transmission provided in an embodiment of this application.

[0037] Figure label:

[0038] 1. Shift hub; 2. Reverse gear shift slide; 3. 2nd / 4th gear shift slide; 4. Auxiliary shift slide; 5. 3rd / 5th gear shift slide; 6. Planetary gear mechanism; 7. Reverse gear synchronizer; 8. 2nd / 4th gear synchronizer; 9. Auxiliary synchronizer; 10. First clutch; 11. Second clutch; 12. First input shaft; 13. Second input shaft; 14. Reverse gear; 15. Second gear; 16. Third gear; 17. Fourth gear; 18. Fifth gear; 19. Sixth gear. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0040] This application provides a dual-clutch transmission shift hub structure and a dual-clutch transmission, which can solve the problem in related technologies where the entire transmission system generates a large instantaneous speed during the switching between reverse and forward gears in wet dual-clutch transmissions, resulting in significant noise caused by the collision of synchronizer bevel teeth.

[0041] See Figure 1 and 2 As shown, the first aspect of this application provides a dual-clutch transmission shift hub structure, including:

[0042] A shift hub 1 has an R-gear shift groove 2, a forward shift groove, and an auxiliary shift groove 4 formed on its outer circumference along its axial direction. The R-gear shift groove 2 is used to slidably connect to a reverse gear shift fork, driving the reverse gear shift fork to reciprocate along its trajectory. The forward gear shift groove is used to slidably connect to a forward gear shift fork, driving the forward gear shift fork to reciprocate along its trajectory. The auxiliary shift groove 4 is used to slidably connect to a forward gear shift fork, driving that forward gear shift fork to reciprocate along its trajectory.

[0043] The final rotation angle value of the shift angle range threshold of the R-gear shift slide 2 is the same as the initial rotation angle value of the shift angle range threshold of the forward shift slide. The shift angle range threshold of the R-gear shift slide 2 controls the rotation angle range of the shift hub 1 during the process of the reverse gear fork in the R-gear shift slide 2 from engaging reverse gear to disengaging reverse gear. The shift angle range threshold of the forward shift slide controls the rotation angle range of the shift hub 1 during the process of the forward gear fork in the forward shift slide being engaged from neutral gear to forward gear.

[0044] Meanwhile, in order to ensure the smooth switching between reverse and forward gears, the final rotation angle value of the shift angle range threshold of the R gear shift slide 2 is the same as the initial rotation angle value of the shift angle range threshold of the forward gear shift slide, so as to enable the process of quickly switching from reverse to forward gear and vice versa.

[0045] The shift angle range threshold of the auxiliary shift slide 4 partially overlaps with that of the R shift slide 2 and the forward shift slide. During the shifting process from reverse to forward in the dual-clutch transmission, before the reverse gear disengages from the reverse synchronizer, the auxiliary shift slide 4 drives a forward shift fork to engage the synchronizer ring of a forward synchronizer with a forward gear through sliding friction, thereby reducing the speed of the input shaft connected to the clutch. Ultimately, this reduces the speed difference between the forward synchronizer and the forward gear that need to mesh, preventing excessive speed difference from causing gear collisions and noise.

[0046] The operation relationship of the synchronizer and the location of static shift noise are analyzed as follows:

[0047] During gear shifting, the shift fork first drives the synchronizer's toothed sleeve to compress the synchronizer ring. Under the pressure, the synchronizer ring moves towards the engagement teeth. Due to its special friction characteristics, the engagement teeth begin to change their motion characteristics and gradually approach the speed of the toothed sleeve. The entire process in the early stage is called the synchronization stage. Static shifting noise is generally very small during this stage and will not cause obvious complaints.

[0048] In the next stage, the gear sleeve continues to move, and the bevel teeth of the gear sleeve begin to contact the bevel teeth of the engagement teeth. Since the vehicle is often stationary during static shifting, the speed on one side of the gear sleeve is basically zero, while the speed on the engagement teeth side is relatively high. Although there is the effect of the synchronizer ring, it is generally difficult to reduce the speed to a very low state. Therefore, due to the large speed difference, the tooth tips of the gear sleeve and the tooth tips of the engagement teeth will collide mechanically, generating a lot of noise. The noise energy at this stage is relatively large, which can easily cause complaints.

[0049] In the final stage, the bevel gear of the sleeve engages with the bevel gear of the engagement gear. Initially, the speeds on both sides gradually converge, reducing the mechanical impact noise. However, as the speed difference slowly disappears, this energy is converted into kinetic energy, causing vehicle vibration. The shifting process ends when the sleeve and engagement gear are fully engaged.

[0050] This application utilizes an auxiliary shift groove 4 to drive a forward gear shift fork to drive a forward gear synchronizer's synchronizer ring to slide and rub against a forward gear during the switching process between reverse and forward gears. This reduces the speed of the input shaft connected to the clutch, preventing the speed difference between the clutch friction plates and release plates in the wet dual-clutch transmission from causing a shearing effect on the oil and generating torque on the output shaft. This avoids noise caused by a large speed difference during gear shifting.

[0051] In some alternative embodiments: see Figure 1 and 2 As shown, the first aspect of this application provides a dual-clutch transmission shift hub structure. The forward shift groove of the dual-clutch transmission shift hub structure includes a 2 / 4 gear shift groove 3 and a 3 / 5 gear shift groove 5. The shift angle range threshold of the auxiliary shift groove 4 coincides with the rotation angle range threshold of the last segment of the R gear shift groove 2 and the rotation angle range threshold of the first segment of the 2 / 4 gear shift groove 3.

[0052] The auxiliary shift slide 4 and the 3 / 5 gear shift slide 5 are on the same slide, and the shift angle range threshold of the auxiliary shift slide 4 is less than that of the 3 / 5 gear shift slide 5. The travel of the shift angle range threshold of the auxiliary shift slide 4 in the axial direction of the shift hub 1 is less than that of the 3 / 5 gear shift slide 5 in the axial direction of the shift hub 1, thereby preventing the auxiliary shift slide 4 from engaging the forward gear shift fork in third or fifth gear.

[0053] The shift angle range threshold of R gear shift slide 2 is 14.4 to 41.5 degrees, the shift angle range threshold of 2 / 4 gear shift slide 3 is 41.5 to 68.6 degrees, and the shift angle range threshold of auxiliary shift slide 4 is 20.5 to 62.5 degrees.

[0054] The entire static shifting process is between 14.4° and 68.6°. The reverse shift fork movement range is from 14.4° to 41.5°, and the 2 / 4 gear shift fork movement range is from 41.5° to 68.6°. 41.5° is the neutral position of the reverse and 2 / 4 gear shift forks. At this position, there will be a large fluctuation in the input shaft speed. In order to suppress this speed fluctuation, the function of the auxiliary shift fork (i.e., the 3 / 5 gear shift fork) is introduced around 41.5°. The auxiliary shift fork is used to drive the movement of the auxiliary synchronizer (i.e., the 3 / 5 gear synchronizer). The movement of the auxiliary shift fork is divided into three stages.

[0055] In the first stage, in order to suppress the speed fluctuation caused by reversing out, the 3 / 5 gear synchronizer needs to be synchronized when reversing out to the top tooth stage. Therefore, the inflection point B of the auxiliary shift groove 4 is the initial synchronization position of the 3 / 5 gear synchronizer, and position A is the neutral position of the 3 / 5 gear synchronizer. The stage from A to B is equivalent to the gear engagement process of the 3 / 5 gear synchronizer. The slope of the profile is completely the same as the slope of the profile when engaging third gear. The specific angles are shown in Table 1 below.

[0056] The second stage is the working stage of the 3 / 5 gear synchronizer, such as Figure 2 In the B to C stage, the 3 / 5 gear synchronizer is in the synchronization stage. The input shaft speed is reduced to the minimum through the friction of the synchronizer ring, thereby effectively reducing the static shifting noise in the next stage.

[0057] The third stage is the 2 / 4 gear synchronizer engagement stage. Before the 2 / 4 gear synchronizer reaches the synchronization point, the speed still fluctuates. Therefore, point C is the starting synchronization position of the 2 / 4 gear synchronizer, and point D is the neutral position. The stage from C to D is completely equivalent to the 3 / 5 gear synchronizer disengagement process. The slope of the profile is completely equal to the slope of the third gear disengagement profile. The specific angles are shown in Table 1 below.

[0058] The above three stages illustrate the design principle of the shift curve from R to D gear, while the shift from D to R gear is the complete opposite. Due to the difference in angle between upshifting and downshifting, the inflection point of the auxiliary shift groove 4-type line should be compatible with all angles of both. Therefore, the angle range designed for the auxiliary shift groove 4-type line is 20.5° to 62.5°, and the specific angle relationships are shown in Table 2.

[0059] The final rotation angle value of the R gear shift slide 2 shift angle range threshold and the initial rotation angle value of the forward gear shift slide 2 shift angle range threshold are both 41.5 degrees. A planetary gear mechanism 6 is provided inside the shift hub 1. The input end of the planetary gear mechanism 6 is connected to a motor that drives the planetary gear mechanism 6. The motor drives the shift hub 1 to reciprocate within the range of 0 to 200.8 degrees through the planetary gear mechanism 6, realizing seven-gear shifting operation.

[0060] Table 1. Relationship between Auxiliary Synchronizer Position and Shift Hub Angle (R to D)

[0061]

[0062] Table 2. Relationship between Auxiliary Synchronizer Position and Shift Hub Angle (D to R)

[0063]

[0064] Table 3. Relationship between Shift Synchronizer Position and Shift Hub Angle (R to D)

[0065]

[0066] Table 4. Relationship between Shift Synchronizer Position and Shift Hub Angle (D to R)

[0067]

[0068] See Figures 1 to 3 As shown, a second aspect of this application provides a dual-clutch transmission, comprising:

[0069] The transmission housing contains the dual-clutch transmission shift hub structure described in any of the above embodiments. The transmission housing also includes a reverse synchronizer 7 for engaging the reverse gear 14 and the sixth gear 19, a 2 / 4 gear synchronizer 8 for engaging the second gear 15 and the fourth gear 17, and an auxiliary synchronizer 9 for engaging the third gear 16 and the fifth gear 19.

[0070] The reverse gear fork that moves the reverse gear synchronizer 7 is slidably connected in the R gear shift groove 2 of the shift hub 1. The 2 / 4 gear shift groove 3 of the shift hub 1 is slidably connected in the 2 / 4 gear shift fork that moves the 2 / 4 gear synchronizer 8. The 3 / 5 gear shift fork that moves the 3 / 5 gear synchronizer is slidably connected in the auxiliary shift groove 4 of the shift hub 1. The auxiliary synchronizer 9 is the 3 / 5 gear synchronizer.

[0071] The gearbox housing also includes a first clutch 10 and a second clutch 11. The first clutch 10 is connected to the third gear 16 and the fifth gear 19 via the first input shaft 12, and the second clutch 11 is connected to the second gear 15, the fourth gear 17 and the sixth gear 19 via the second input shaft 13.

[0072] Before the reverse gear fork disengages the reverse synchronizer 7 from the reverse gear, the 3 / 5 gear fork engages the synchronizer ring of the 3 / 5 gear synchronizer, causing it to slide and connect with the third gear 16 or the fifth gear 18, thereby reducing the speed of the first input shaft 12. After the 2 / 4 gear fork engages the 2 / 4 gear synchronizer 8 with the second or fourth gear, the 3 / 5 gear fork disengages the synchronizer ring of the 3 / 5 gear synchronizer from the third gear 16 or the fifth gear 18 to the neutral position.

[0073] according to Figure 2 The schematic diagram of the shift hub groove profile shown indicates that before static shifting (0-14.4°), the reverse synchronizer 7 is in gear, the 2 / 4 gear synchronizer 8 is in second gear, and the bridge is in gear. The power flow inside the entire gearbox is as follows: the first clutch 10 is connected to the fifth gear 18, the fifth gear 18 is connected to the sixth gear 19 through the bridge, the sixth gear 19 is connected to the second gear 15, the second gear 15 is connected to the reverse gear 14, the reverse gear 14 is connected to the main reduction gear through the output shaft, and finally reaches the wheel position.

[0074] Since the vehicle is stationary, the entire transmission gear chain is locked, and all gears except for the third gear 16 are stationary. It is precisely because of the freedom of the third gear 16 that the 3 / 5 gear synchronizer can participate in the static shifting process as an auxiliary synchronizer 9.

[0075] Before static shifting, the controller delays the shift command by 0.3 seconds to allow the pressure of the first clutch 10 to drop to its minimum before the shift drum begins to rotate. Taking static shifting from R to D as an example, as the static shift proceeds, the shift drum rotates and the reverse synchronizer 7 slowly disengages. When it disengages to 20.5°, the auxiliary synchronizer 9 engages. At this point, the auxiliary synchronizer 9 and the reverse synchronizer 7 move simultaneously. When they reach 30.5°, the auxiliary synchronizer 9 has reached the synchronization point, while the reverse synchronizer 7 has disengaged to the top tooth stage. Without the action of the auxiliary synchronizer 9, the entire gear chain would begin to transition from static to dynamic under the drag torque of the clutch, causing the entire transmission chain to generate a large impact speed.

[0076] Therefore, the intervention of the auxiliary synchronizer 9 effectively compensates for the speed fluctuations caused by the disengagement of the reverse synchronizer 7. As the shift drum rotates to 41.5°, the reverse synchronizer 7 has essentially disengaged completely from reverse. The shift drum then continues to rotate from 41.5° to 51.7°, and the 2 / 4 gear synchronizer 8 moves from neutral to the synchronization point. Once the 2 / 4 gear synchronizer 8 reaches the synchronization point, it is already in the synchronized position, requiring no other mechanism to stabilize speed fluctuations. The auxiliary synchronizer 9 then begins to downshift, continuing downshifting to 61.8° to reach neutral. The entire static shift from R to D is complete. During this stage, the entire system is stationary, effectively suppressing noise generation.

[0077] The shifting process from D to R is the exact opposite of the shifting from R to N. The initial angle of the 2 / 4 gear synchronizer 8 in gear is 68.6°. Rotating the shift drum causes the 2 / 4 gear synchronizer 8 to begin downshifting, reaching the top tooth stage at 52.6°. Simultaneously, the auxiliary synchronizer 9 moves from neutral to the synchronization point. The next step involves rotating the shift drum again, causing the reverse synchronizer 7 to engage from 41.5° to 31.5°, reaching the synchronization point. The auxiliary synchronizer 9 then downshifts to neutral until the shift is complete. Throughout this process, due to factors such as synchronizer clearance, the initial angle and the ending angle of the R to N shift are not perfectly aligned. Incorporating an angle deviation design value in the specific design will compensate for this difference.

[0078] Working principle

[0079] This application provides a dual-clutch transmission shift hub structure and a dual-clutch transmission. The dual-clutch transmission shift hub structure of this application includes a shift hub body 1, on the outer circumference of which are formed an R-gear shift groove 2, a forward shift groove, and an auxiliary shift groove 4. The final rotation angle value of the shift angle range threshold of the R-gear shift groove 2 is the same as the initial rotation angle value of the shift angle range threshold of the forward shift groove. The shift angle range threshold of the auxiliary shift groove 4 partially overlaps with the shift angle range threshold of the R-gear shift groove 2 and the shift angle range threshold of the forward shift groove.

[0080] Therefore, the dual-clutch transmission shift hub structure of this application adds an auxiliary shift groove 4 to the outer circumferential surface of the original shift hub body 1. The shift angle range threshold of the auxiliary shift groove 4 partially overlaps with the shift angle range threshold of the R shift groove 2 and the shift angle range threshold of the forward shift groove.

[0081] During the shift from reverse to forward gear in the dual-clutch transmission, before the reverse gear disengages from the reverse synchronizer 7, the auxiliary shift groove 4 drives a shift fork to engage the synchronizer ring of a forward gear synchronizer with a forward gear through sliding friction. This reduces the speed of the input shaft connected to the clutch. Ultimately, this reduces the speed difference between the forward synchronizer and the forward gear that need to mesh, controlling the speed difference between 6.9-13.5 rpm, far below the theoretical synchronization speed difference value of the synchronizer. This significantly improves static shifting efficiency and reduces static shifting noise.

[0082] In the description of this application, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0083] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0084] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A dual clutch transmission shift hub structure, characterized by, include: The gear shift hub (1) has an R gear shift groove (2), a forward gear shift groove and an auxiliary shift groove (4) on its outer circumferential surface. The final rotation angle value of the R gear shifting slide (2) shifting angle range threshold is the same as the initial rotation angle value of the forward gear shifting slide shifting angle range threshold. The shift angle range threshold of the auxiliary shift slide (4) is partially the same as the shift angle range threshold of the R shift slide (2) and the shift angle range threshold of the forward shift slide. During the process of switching from reverse gear to forward gear in a dual-clutch transmission, before the reverse gear and reverse synchronizer have disengaged, the auxiliary shift groove (4) drives a forward gear shift fork to drive the synchronizer ring of a forward gear synchronizer to slide and rub against a forward gear, thereby reducing the speed of the input shaft connected to the clutch and reducing the speed difference between the forward gear synchronizer and the forward gear that need to mesh with each other.

2. The dual-clutch transmission shift hub structure as described in claim 1, characterized in that: The forward gear shifting slide includes a 2 / 4 gear shifting slide (3) and a 3 / 5 gear shifting slide (5). The shifting angle range threshold of the auxiliary shifting slide (4) coincides with the rotation angle range threshold of the last segment of the R gear shifting slide (2) and the rotation angle range threshold of the first segment of the 2 / 4 gear shifting slide (3).

3. The dual-clutch transmission shift hub structure as described in claim 2, characterized in that: The auxiliary shift groove (4) and the 3 / 5 gear shift groove (5) are on the same groove, and the shift angle range threshold of the auxiliary shift groove (4) is less than the shift angle range threshold of the 3 / 5 gear shift groove (5). The shift angle range threshold of the auxiliary shift groove (4) is less than the stroke of the shift angle range threshold of the 3 / 5 gear shift groove (5) in the direction of the axis of the shift hub (1).

4. The dual-clutch transmission shift hub structure as described in claim 2, characterized in that: The shift angle range threshold of the R gear shift slide (2) is 14.4 to 41.5 degrees, the shift angle range threshold of the 2 / 4 gear shift slide (3) is 41.5 to 68.6 degrees, and the shift angle range threshold of the auxiliary shift slide (4) is 20.5 to 62.5 degrees.

5. The dual-clutch transmission shift hub structure as described in claim 4, characterized in that: The final rotation angle value of the R gear shifting slide (2) shifting angle range threshold and the initial rotation angle value of the forward gear shifting slide shifting angle range threshold are both 41.5 degrees.

6. The dual-clutch transmission shift hub structure as described in claim 1, characterized in that: It also includes a planetary gear mechanism (6) located inside the shift hub (1). The input end of the planetary gear mechanism (6) is connected to a motor that drives the planetary gear mechanism (6). The motor drives the shift hub (1) to reciprocate within the range of 0 to 200.8 degrees through the planetary gear mechanism (6).

7. A dual clutch transmission, characterized by include: A gearbox housing, wherein the dual-clutch gearbox shift hub structure according to any one of claims 1 to 6 is installed inside the gearbox housing.

8. A dual-clutch transmission as described in claim 7, characterized in that: The gearbox housing is also provided with a reverse gear synchronizer (7) for engaging the reverse gear (14) and the sixth gear (19), a 2 / 4 gear synchronizer (8) for engaging the second gear (15) and the fourth gear (17), and an auxiliary synchronizer (9) for engaging the third gear (16) and the fifth gear (18). The reverse gear shift fork that moves the reverse gear synchronizer (7) is slidably connected in the R gear shift groove (2) of the shift hub (1). The 2 / 4 gear shift groove (3) of the shift hub is slidably connected in the 2 / 4 gear shift groove (8). The 3 / 5 gear shift fork that moves the 3 / 5 gear synchronizer is slidably connected in the auxiliary shift groove (4) of the shift hub (1).

9. A dual-clutch transmission as described in claim 8, characterized in that: The gearbox housing is also provided with a first clutch (10) and a second clutch (11). The first clutch (10) is connected to the third gear (16) and the fifth gear (18) through the first input shaft (12). The second clutch (11) is connected to the second gear (15), the fourth gear (17) and the sixth gear (19) through the second input shaft (13).

10. A dual-clutch transmission as described in claim 9, characterized in that: Before the reverse gear fork disengages the reverse gear synchronizer (7) from the reverse gear, the 3 / 5 gear fork engages the 3 / 5 gear synchronizer's synchronization ring with the third gear (16) or the fifth gear (18) to achieve frictional sliding connection, thereby reducing the rotational speed of the first input shaft (12). When the 2 / 4 gear shift fork engages the 2 / 4 gear synchronizer (8) with the second gear (15) or the fourth gear (17), the 3 / 5 gear shift fork engages the synchronizing ring of the 3 / 5 gear synchronizer with the third gear (16) or the fifth gear (18) to the neutral position.

Images