Tooth-in transmission for vehicle

Abstract

The utility model provides a tooth-embedded transmission for a vehicle. The tooth-embedded transmission for the vehicle enables arrangement change of change gears to be easy and can achieve universalization of parts. The shift drum (70) comprises a drum shaft (72) and a cylindrical drum ring (74), and the drum ring (74) is provided with a shift groove (76) in the outer periphery and is integrally and rotatably fixed to the drum shaft (72). Thus, the arrangement of the drum ring (74) having the shift groove (76) corresponding to the transmission gear can be changed according to the change of the arrangement of the transmission gear, and thus the change of the arrangement of the transmission gear can be easily performed. In addition, components of the drum shaft (72) and the drum ring (74) can be universally used.

Description

Technical Field

[0001] This utility model relates to a dog clutch transmission for vehicles that switches gear stages based on the rotation of a shift drum. Background Technology

[0002] A known vehicle dog clutch transmission includes: a rotating shaft; a plurality of gears arranged on the rotating shaft to rotate relative to each other; a plurality of switching mechanisms disposed axially on the rotating shaft adjacent to the gears, capable of switching between a connected state in which the gears rotate integrally with the rotating shaft and a disconnected state in which the gears rotate relative to the rotating shaft; and a shifting mechanism that moves the switching mechanisms along the axial direction of the rotating shaft. The shifting mechanism includes: a shift drum having shift grooves that define the position of the shifting mechanism; and a shift actuator that rotates the shift drum, causing the switching mechanisms to move axially along the rotating shaft in response to the rotation of the shift drum, thereby being shifted into multiple gear levels. For example, Patent Document 1 describes such a vehicle transmission. Patent Document 1 discloses a technique for shifting gear levels by moving the switching mechanism through an annular shift groove formed in the shift drum.

[0003] [Existing Technical Documents]

[0004] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2022-146775

[0006] [The problem that the utility model aims to solve]

[0007] However, for example, when expanding to other vehicle types, if the arrangement of the gear stages in the transmission needs to be changed, the arrangement of the shift grooves also needs to be changed. However, since the shift grooves are formed in the shift drum, the shift drum must be redesigned and remanufactured according to the changes, resulting in increased labor time and extended cycle time. In addition, since the shift drum becomes a special part for that vehicle type, there are also challenges in terms of component commonality. Utility Model Content

[0008] This invention was made against the background described above, and its purpose is to provide a vehicle gearbox that makes the arrangement of transmission gears easier and enables the generalization of components.

[0009] [Solution to the problem]

[0010] The present invention aims to provide a dog clutch transmission for a vehicle, the dog clutch transmission comprising: (a) a rotating shaft; a plurality of transmission gears rotatably disposed on the rotating shaft; a plurality of switching mechanisms disposed axially adjacent to the transmission gears on the rotating shaft, capable of switching between a connected state in which the transmission gears rotate integrally with the rotating shaft and a disconnected state in which the transmission gears rotate relative to the rotating shaft; and a shifting mechanism, the shifting mechanism enabling the transmission gears to rotate independently with the rotating shaft. (a) The shifting mechanism moves axially along the rotating shaft; (b) The shifting mechanism includes: a shift drum having a shift groove that defines the position of the shifting mechanism; and a shift actuator that rotates the shift drum; (c) The shifting mechanism moves axially along the rotating shaft in response to the rotation of the shift drum, thereby changing the speed to multiple gear levels; (d) The shift drum includes a drum shaft and a cylindrical drum ring; (e) The drum ring has the shift groove formed on its outer circumference and is integrally rotatably fixed to the drum shaft.

[0011] [Effects of the utility model]

[0012] According to the present invention, the shift drum includes a drum shaft and a cylindrical drum ring. The drum ring has the shift groove formed on its outer circumference and is integrally rotatably fixed to the drum shaft. Therefore, the arrangement of the drum ring with the shift groove corresponding to the shift gears can be changed according to the arrangement of the gears, thus facilitating easy changes to the gear arrangement. Furthermore, the components of the drum shaft and the drum ring can be standardized. Attached Figure Description

[0013] Figure 1 This is a diagram illustrating the schematic structure of a vehicle to which this utility model is applied.

[0014] Figure 2 This is a diagram illustrating the structure of the drum shaft of the transmission that utilizes this invention.

[0015] [Explanation of Labels in the Attached Image]

[0016] 26: Transmission (vehicle dog clutch transmission) 34: Driven gear (speed change gear) 36: Shifting mechanism 52: Countershaft (rotating shaft) 60: Shifting mechanism 66: Shift actuator 70: Shift drum 72: Drum shaft 74: Drum ring 76: Shift groove CL3: Rotating axis Detailed Implementation

[0017] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0018]

Example

[0019] Figure 1 This is a diagram illustrating the schematic structure of the vehicle 10 to which this utility model is applied. Figure 1 The vertical direction on the paper indicates the direction of travel of vehicle 10. Figure 1 In this vehicle 10, an engine 12 functions as a power source; a pair of drive wheels 14; and a power transmission unit 16. The engine 12 and the power transmission unit 16 are connected via an input shaft 18, and the power transmission unit 16 and the drive wheels 14 are connected via a pair of drive shafts 20. It should be noted that the power source may be an electric motor in addition to the engine 12, or an electric motor may replace the engine 12.

[0020] The engine 12 is, for example, a known internal combustion engine. The electronic control device 80, described later, controls the fuel injection device, ignition device, etc., provided by the vehicle 10, thereby controlling the engine torque Te, which is the torque of the engine 12.

[0021] The power transmission unit 16 includes a clutch K1, a hydraulic control circuit 22, a bevel gear 24, a transmission 26, and a limited-slip differential (hereinafter referred to as the LS differential) 58. Power from the engine 12 is transmitted via the input shaft 18 in the order of clutch K1, bevel gear 24, transmission 26, and LS differential 58, and then from the LS differential 58 to the drive wheels 14 via the drive shaft 20. The LS differential 58 is a differential device equipped with a differential limiting mechanism.

[0022] Clutch K1 is a hydraulic friction engagement device located between engine 12 and transmission 26. Clutch K1 switches control states (engaged state, released state) by hydraulic pressure PRk1 supplied from hydraulic control circuit 22.

[0023] The bevel gear 24 is connected to the intermediate shaft 28, which serves as the input shaft of the clutch K1 and the transmission 26, and transmits the power from the engine 12 via the clutch K1 through the intermediate shaft 28, which serves as the rotation axis in the forward direction of the vehicle 10 and the rotation axis in the width direction.

[0024] The transmission 26 is a so-called parallel dual-shaft transmission that forms any one of multiple gear stages (also synonymous with gear shifting stages) GS with different gear ratios (gear shifting ratio is also synonymous) γ (= input rotational speed Ni / output rotational speed No). The input rotational speed Ni is the rotational speed of the intermediate shaft 28, and the output rotational speed No is the rotational speed of the countershaft (hereinafter referred to as the C-shaft) 52, which serves as the output shaft of the transmission 26. The transmission 26 is equivalent to the "vehicle dog clutch transmission" of this utility model, and the C-shaft 52 is equivalent to the "rotating shaft" of this utility model.

[0025] The transmission 26 has multiple gear pairs 30 that are always engaged. The gear pairs 30, in the direction of the rotation axis CL1, sequentially include, from the bevel gear 24 side (input side), a reverse gear pair 30a, a second gear pair 30b, a first gear pair 30c, a fourth gear pair 30d, a fifth gear pair 30e, a sixth gear pair 30f, and a third gear pair 30g. The direction of the rotation axis CL1 is synonymous with the axial direction of the intermediate shaft 28.

[0026] The gear pair 30 includes drive gears 32 (including 32a1, 32a2, 32b, 32c, 32d, 32e, 32f, and 32g) and driven gears 34 (including 34a, 34b, 34c, 34d, 34e, 34f, and 34g) that are always meshed with the drive gears 32. The reversing gear pair 30a includes two drive gears 32a1 and 32a2 for reversing the driving direction. The drive gears 32 are configured to be non-rotatable relative to the intermediate shaft 28. The driven gears 34 are rotatably fixed to the C-axis 52 in the direction of the rotation axis CL2. The rotation axis CL2 is synonymous with the axial direction of the C-axis 52. The driven gears 34 are equivalent to the "multiple speed-changing gears" of this invention.

[0027] The transmission 26 includes multiple switching mechanisms 36 (including 36a, 36b, 36c, and 36d) arranged on the C-axis 52. The first switching mechanism 36a is positioned adjacent to the reverse driven gear 34a in the direction of the rotation axis CL2. The second switching mechanism 36b is positioned adjacent to the second driven gear 34b and the first driven gear 34c. The third switching mechanism 36c is positioned adjacent to the fourth driven gear 34d and the fifth driven gear 34e. The fourth switching mechanism 36d is positioned adjacent to the sixth driven gear 34f and the third driven gear 34g.

[0028] The switching mechanism 36 switches the power transmission state at the gear pair 30 to a state where power transmission is possible or not. The switching mechanism 36 is a disconnect / connection device that can switch between a connected state, in which one of the drive gears 32 located in an adjacent position is connected to the C-shaft 52 and they rotate as a whole, and a disconnected state, in which the other is disconnected from the C-shaft 52 and they rotate relative to each other.

[0029] For example, when the reverse driven gear 34a is connected to the C-shaft 52 via the first switching mechanism 36a, the transmission 26 is switched to a power transmission state via the reverse gear pair 30a, forming a reverse gear stage Rev in the transmission 26. The same applies to the second gear stage 2nd, the first gear stage 1st, the fourth gear stage 4th, the fifth gear stage 5th, the sixth gear stage 6th, and the third gear stage 3rd.

[0030] In the switching mechanism 36, switching meshing teeth 38 (including 38a, 38b, 38c, 38d, 38e, 38f, and 38g) are formed in the direction of the rotation axis CL2 facing the driven gear 34. In the driven gear 34, gear-side meshing teeth 40 (including 40a, 40b, 40c, 40d, 40e, 40f, and 40g) are formed in the direction of the rotation axis CL2 facing the switching mechanism 36, which can mesh with the switching meshing teeth 38.

[0031] The transmission 26 is a dog clutch transmission with dog clutches 50 (including 50a, 50b, 50c, 50d, 50e, 50f, and 50g). The dog clutch 50 is a meshing clutch composed of gear-side meshing teeth 40 and a switching mechanism 36 equipped with switching meshing teeth 38. The switching meshing teeth 38 and the gear-side meshing teeth 40 are meshing teeth, i.e., dog clutch teeth, that constitute part of the dog clutch 50. The dog clutch 50 is engaged by the meshing of the dog clutch teeth, and disengaged by releasing this engagement.

[0032] The transmission 26 includes a shift mechanism 60 for moving the shift mechanism 36 along the rotation axis CL2. The shift mechanism 60 includes shift forks 62 (including 62a, 62b, 62c, and 62d) that engage with the shift mechanism 36, a shift drum 70, and a shift actuator 66. The shift drum 70 includes shift grooves 76 (including 76a, 76b, 76c, and 76d) that define the movement position of the shift mechanism 36 in the rotation axis CL2 direction via the shift forks 62.

[0033] The shift groove 76 is formed circumferentially along the shift drum 70, with a portion of its circumferential direction bent along the axial direction of the shift drum 70. Therefore, when the shift drum 70 is rotated, the shift fork 62 moves axially along the groove shape of the shift groove 76. Furthermore, as the shift fork 62 moves axially along the shift drum 70, the shifting mechanism 36 moves in conjunction with the shift fork 62 along the rotation axis CL2. The shape of the shift groove 76 relative to the circumferential position of the shift drum 70 varies. The shape of the shift groove 76 is formed such that, as the shift drum 70 rotates, the transmission 26 sequentially shifts between the reverse gear stage (Rev) and the sixth gear stage (6th).

[0034] Corresponding to the rotation of the shift drum 70, the switching mechanism 36 moves to a predetermined position in the direction of the rotation axis CL2, thereby the transmission 26 switches the disengagement / engagement state of the dog clutch 50 to shift into multiple transmission levels. The disengagement / engagement state of the dog clutch 50 includes a connected state where power transmission between the drive gear 32 and the C-shaft 52 can proceed (synonymous with the engaged state), and a disengagement state where power transmission between the drive gear 32 and the C-shaft 52 is disconnected (synonymous with the non-engaged state).

[0035] The power transmission between the C-shaft 52 and the LS differential 58 is carried out via the final drive shaft (hereinafter referred to as the FD shaft) 56. The C-shaft 52 and the FD shaft 56 are connected by spline engagement (spline engagement part 54), and the FD shaft 56 and the LS differential 58 are connected by drive gear 56a meshing with final gear 58a.

[0036] The vehicle 10 also includes an electronic control unit 80, which serves as a controller and is associated with the control of the engine 12, the power transmission unit 16, and other components of the vehicle 10. The electronic control unit 80 is configured to include a so-called microcomputer.

[0037] Various signals based on detection values ​​generated by various sensors on the vehicle 10 are supplied to the electronic control unit 80. These sensors include, for example, an engine rotation speed sensor 90, an input rotation speed sensor 92, an output rotation speed sensor 94, and an acceleration opening sensor 96. The various signals include, for example, engine rotation speed Ne, input rotation speed Ni, output rotation speed No, and acceleration opening θacc. The output rotation speed No is the rotation speed corresponding to the vehicle speed V.

[0038] The electronic control unit 80 outputs various command signals to the various devices equipped in the vehicle 10. These devices include, for example, the engine 12, the hydraulic control circuit 22, and the shift actuator 66. The various command signals include, for example, the engine control command signal Se, the hydraulic control command signal Sk1, and the drum control command signal Sbrl. The drum control command signal Sbrl is a control command signal used to drive the shift drum 70 to rotate.

[0039] The electronic control unit 80 calculates the required drive torque Trdem by applying the acceleration opening θacc and vehicle speed V to a predetermined drive requirement mapping. Taking into account the gear ratio γ of the transmission 26, the electronic control unit 80 outputs an engine control command signal Se to obtain the engine torque Te required to achieve the required drive torque Trdem. Furthermore, the electronic control unit 80 uses a predetermined shift mapping to determine the shift of the transmission 26, and outputs a drum control command signal Sbrl to drive the shift drum 70 to rotate and perform shift control of the transmission 26 as needed.

[0040] However, for example, when expanding to other vehicle types, if the arrangement of the gear stages of the transmission 26 needs to be changed, the arrangement of the shift grooves 76 also needs to be changed. However, conventionally, the shift grooves 76 are integrally formed on the shift drum 70 as part of its shape. Therefore, the shift drum 70 must be redesigned and remanufactured according to the changes, resulting in increased labor time and longer production cycles. Furthermore, since the shift drum 70 is a dedicated part for that specific vehicle type, there are also challenges in terms of component commonality.

[0041] Therefore, in this embodiment, by Figure 2 The structure of the shift drum 70 shown allows for easy changes in the arrangement of gear stages. Figure 2 This is a three-dimensional diagram illustrating the structure of the shift drum 70.

[0042] exist Figure 2 In this design, the shift drum 70 includes: a drum shaft 72 connected to a shift actuator 66, which rotates about a rotation axis CL3; and four cylindrical drum rings 74 (74a, 74b, 74c, 74d). Figure 2 As shown, the drum rings 74 (74a, 74b, 74c, 74d) have shift grooves 76 (76a, 76b, 76c, 76d) formed on their outer circumferences, and are integrally and rotatably fixed to the drum shaft 72. The drum rings 74 are fixed to the drum shaft 72 by appropriate methods such as heat fitting or pressing.

[0043] Furthermore, the drum rings 74 (74a, 74b, 74c, 74d) do not necessarily need to be all four as shown in this embodiment; only the required portions may be provided. Portions that do not require modification may be mixed with, for example, the shift grooves 76 formed in the shift drum 70.

[0044] As described above, according to this embodiment, the shift drum 70 includes a drum shaft 72 and a cylindrical drum ring 74. The drum ring 74 has a shift groove 76 formed on its outer periphery and is integrally rotatably fixed to the drum shaft 72. Therefore, the arrangement of the drum ring 74, which has shift grooves 76 corresponding to the shift gears, can also be changed according to the arrangement of the shift gears, thus facilitating changes in the shift gear arrangement. Furthermore, the components of the drum shaft 72 and the drum ring 74 can be standardized.

[0045] The embodiments of the present invention have been described in detail above based on the accompanying drawings. However, the present invention can be implemented in various modified and improved forms based on the knowledge of those skilled in the art.

Claims

1. A dog clutch transmission for vehicles, wherein, The vehicle dog clutch transmission includes: a rotating shaft; a plurality of gears rotatably disposed on the rotating shaft; and a plurality of switching mechanisms disposed axially adjacent to the gears on the rotating shaft, capable of switching between a connected state in which the gears rotate integrally with the rotating shaft and a disconnected state in which the gears rotate relative to the rotating shaft. And a shifting mechanism that causes the switching mechanism to move axially along the rotating shaft. The shifting mechanism includes: a shifting drum, the shifting drum having a shifting groove that defines the position of the shifting mechanism; And a shift actuator that rotates the shift drum. The switching mechanism moves axially along the rotation axis in response to the rotation of the shift drum, thereby changing the speed into multiple speed levels. The vehicle-mounted dog clutch transmission is characterized by the following features: The shift drum includes a drum shaft and a cylindrical drum ring. The drum ring has the shift groove formed on its outer periphery and can be rotatably fixed to the drum shaft as a whole.

Images