Dog transmission for vehicle

Abstract

To provide a dog type transmission for a vehicle capable of easily changing the arrangement of transmission gears and using parts in common.SOLUTION: The shift barrel 70 includes a barrel shaft 72 and a cylindrical barrel ring 74. The barrel ring 74 has a shift groove 76 on its outer periphery and is fixed to the barrel shaft 72 so as to be rotatable together with the barrel shaft 72. As a result, the arrangement of the barrel ring 74 having the shift grooves 76 corresponding to the transmission gears can also be changed according to the change in the arrangement of the transmission gears, so that the arrangement of the transmission gears can be easily changed. In addition, the barrel shaft 72 and the barrel ring 74 can be used as common components.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a dog-type transmission for a vehicle in which gears are changed in accordance with the rotation of a shift barrel. [Background technology]

[0002] A dog-type vehicle transmission is well known, comprising a rotating shaft, a plurality of speed change gears rotatably mounted on the rotating shaft, a plurality of switching mechanisms arranged adjacent to the speed change gears in the axial direction of the rotating shaft and switchable between an engaged state in which the speed change gears and the rotating shaft rotate integrally and a disengaged state in which they rotate relative to each other, and a shift mechanism that moves the switching mechanisms in the axial direction of the rotating shaft, the shift mechanism including a shift barrel with a shift groove that determines the position of the switching mechanisms and a shift actuator that rotates the shift barrel. The shift mechanism is moved in the axial direction of the rotating shaft in response to rotation of the shift barrel, thereby shifting between a plurality of gear stages. For example, Patent Document 1 discloses a vehicle transmission that is such an example. Patent Document 1 discloses that the switching mechanism is moved by an annular shift groove formed in the shift barrel to change gear stages. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-146775 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, for example, when deploying a product in a different vehicle model, if the arrangement of gears in the transmission needs to be changed, the arrangement of the shift grooves also needs to be changed. However, because the shift grooves are formed in the shift barrel, the shift barrel must be redesigned and remanufactured depending on the changes, which poses challenges such as increased man-hours and time. In addition, because the shift barrel is a dedicated part for that vehicle model, there are also challenges in terms of parts standardization.

[0005] The present invention has been made in light of the above circumstances, and its object is to provide a dog-type transmission for a vehicle that makes it easy to change the arrangement of transmission gears and allows for the use of standardized parts. [Means for solving the problem]

[0006] The gist of the present invention is a dog-type transmission for a vehicle comprising: (a) a rotating shaft; a plurality of speed change gears rotatably mounted on the rotating shaft; a plurality of switching mechanisms arranged adjacent to the speed change gears in the axial direction of the rotating shaft and switchable between an engaged state in which the speed change gears and the rotating shaft rotate integrally and a disengaged state in which they rotate relative to each other; and a shift mechanism that moves the switching mechanism in the axial direction of the rotating shaft; (b) the shift mechanism includes a shift barrel having a shift groove that determines the position of the switching mechanism, and a shift actuator that rotates the shift barrel; (c) the switching mechanism is moved in the axial direction of the rotating shaft in accordance with the rotation of the shift barrel, thereby changing gears to a plurality of speed stages; (d) the shift barrel includes a barrel shaft and a cylindrical barrel ring; and (e) the barrel ring has the shift groove formed on its outer periphery and is fixed to the barrel shaft so as to be rotatable integrally with it. [Effects of the Invention]

[0007] According to the present invention, the shift barrel includes a barrel shaft and a cylindrical barrel ring, and the barrel ring has the shift groove formed on its outer periphery and is fixed to the barrel shaft so as to be rotatable integrally with the barrel shaft. This allows the arrangement of the barrel ring, which has the shift groove corresponding to the transmission gear, to be changed in accordance with a change in the arrangement of the transmission gears, making it easy to change the arrangement of the transmission gears. Furthermore, the barrel shaft and the barrel ring can be standardized. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a diagram illustrating a schematic configuration of a vehicle to which the present invention is applied; [Figure 2] 1 is a diagram illustrating the configuration of a barrel shaft of a transmission to which the present invention is applied. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. [Example]

[0010] FIG. 1 is a diagram illustrating the schematic configuration of a vehicle 10 to which the present invention is applied. The vertical upward direction on the plane of FIG. 1 indicates the forward direction of the vehicle 10. In FIG. 1, the vehicle 10 is equipped with an engine 12 that functions as a power source, a pair of drive wheels 14, and a power transmission unit 16. The engine 12 and power transmission unit 16 are connected via an input shaft 18, and the power transmission unit 16 and drive wheels 14 are connected via a pair of drive shafts 20. Note that, for example, an electric motor may be used as the power source in addition to or instead of the engine 12.

[0011] The engine 12 is, for example, a known internal combustion engine, and an electronic control device 80 (described later) controls a fuel injection device, an ignition device, and the like provided on the vehicle 10, thereby controlling the engine torque Te of the engine 12.

[0012] 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 LS differential) 58. Power from the engine 12 is transmitted via an input shaft 18 to the clutch K1, bevel gear 24, transmission 26, and LS differential 58 in that order, and from the LS differential 58 to the drive wheels 14 via a drive shaft 20. The LS differential 58 is a differential device equipped with a differential limiting mechanism.

[0013] The clutch K1 is, for example, a hydraulic friction engagement device provided between the engine 12 and the transmission 26. The clutch K1 has its control state (engaged state, released state) switched by a K1 hydraulic pressure PRk1 supplied from a hydraulic control circuit 22.

[0014] The bevel gear 24 is connected to the clutch K1 and the lay shaft 28, which is the input shaft of the transmission 26, and transmits the power transmitted from the engine 12 via the clutch K1 from the rotation axis in the forward direction of the vehicle 10 to the lay shaft 28, which is the rotation axis in the vehicle width direction.

[0015] The transmission 26 is a so-called parallel two-shaft transmission in which one of a plurality of gear stages (also synonymous with speed ratio) GS with different gear ratios (also synonymous with gear stages) γ (= input rotation speed Ni / output rotation speed No) is formed. The input rotation speed Ni is the rotation speed of the lay shaft 28, and the output rotation speed No is the rotation speed of a countershaft (hereinafter referred to as C-shaft) 52, which is the output shaft of the transmission 26. The transmission 26 corresponds to the "dog-type transmission for a vehicle" of the present invention, and the C-shaft 52 corresponds to the "rotating shaft" of the present invention.

[0016] The transmission 26 includes a plurality of gear pairs 30 that are constantly meshed. The gear pairs 30 include, in order from the bevel gear 24 side (input side) in the direction of the rotation axis CL1, a reverse gear pair 30a, a second-speed gear pair 30b, a first-speed gear pair 30c, a fourth-speed gear pair 30d, a fifth-speed gear pair 30e, a sixth-speed gear pair 30f, and a third-speed gear pair 30g. The direction of the rotation axis CL1 is synonymous with the axial direction of the lay shaft 28.

[0017] The gear pair 30 includes a drive gear 32 (including 32a1, 32a2, 32b, 32c, 32d, 32e, 32f, and 32g) and a driven gear 34 (including 34a, 34b, 34c, 34d, 34e, 34f, and 34g) that is constantly meshed with the drive gear 32. The reverse gear pair 30a includes two drive gears 32a1 and 32a2 for reversing the drive direction. The drive gear 32 is provided so as not to rotate relative to the lay shaft 28. The driven gear 34 is fixed to the C shaft 52 in the direction of the rotation axis CL2 so as to be rotatable relative to the C shaft 52. The direction of the rotation axis CL2 is synonymous with the axial direction of the C shaft 52. The driven gear 34 corresponds to the "plurality of speed-change gears" of this invention.

[0018] The transmission 26 includes a plurality of switching mechanisms 36 (including 36a, 36b, 36c, and 36d) disposed on the C-shaft 52. The first switching mechanism 36a is disposed adjacent to the reverse driven gear 34a in the direction of the rotation axis CL2. The second switching mechanism 36b is disposed adjacent to the second-speed driven gear 34b and the first-speed driven gear 34c. The third switching mechanism 36c is disposed adjacent to the fourth-speed driven gear 34d and the fifth-speed driven gear 34e. The fourth switching mechanism 36d is disposed adjacent to the sixth-speed driven gear 34f and the third-speed driven gear 34g.

[0019] The switching mechanism 36 switches the power transmission state of the gear pair 30 between a power transmission enabled state and a power transmission disabled state. The switching mechanism 36 is a disconnecting device that can switch between a connected state in which one of the adjacent drive gears 32 is connected to the C shaft 52 so that they rotate integrally, and a disconnected state in which the other drive gear 32 is disconnected from the C shaft 52 so that they rotate relative to each other.

[0020] For example, when the reverse driven gear 34a and the C shaft 52 are connected via the first switching mechanism 36a, the transmission 26 is switched to a power transmission enabled state via the reverse gear pair 30a, and a reverse gear Rev is formed in the transmission 26. The same applies to second gear 2nd, first gear 1st, fourth gear 4th, fifth gear 5th, sixth gear 6th, and third gear 3rd.

[0021] The switching mechanism 36 has switching meshing teeth 38 (including 38a, 38b, 38c, 38d, 38e, 38f, and 38g) formed at a position facing the driven gear 34 in the direction of the rotation axis CL2. The driven gear 34 has gear-side meshing teeth 40 (including 40a, 40b, 40c, 40d, 40e, 40f, and 40g) that can mesh with the switching meshing teeth 38 formed at a position facing the switching mechanism 36 in the direction of the rotation axis CL2.

[0022] The transmission 26 is a dog-type transmission having dog clutches 50 (including 50a, 50b, 50c, 50d, 50e, 50f, and 50g). The dog clutch 50 is a dog clutch that is made up of a switching mechanism 36 with switching meshing teeth 38, gear-side meshing teeth 40, and the like. The switching meshing teeth 38 and the gear-side meshing teeth 40 are meshing teeth, or dog teeth, that make up part of the dog clutch 50. The dog clutch 50 is brought into an engaged state by meshing between the dog teeth, and is brought into a disengaged state by releasing the meshing.

[0023] The transmission 26 includes a shift mechanism 60 for moving the switching mechanism 36 in the direction of the rotational axis CL2. The shift mechanism 60 includes shift forks 62 (including 62a, 62b, 62c, and 62d) that fit into the switching mechanism 36, a shift barrel 70, and a shift actuator 66. The shift barrel 70 includes shift grooves 76 (including 76a, 76b, 76c, and 76d) that determine the movement position of the switching mechanism 36 in the direction of the rotational axis CL2 via the shift fork 62.

[0024] The shift grooves 76 are formed along the circumferential direction of the shift barrel 70, with a portion of the circumferential direction bent in the axial direction of the shift barrel 70. Therefore, when the shift barrel 70 is rotated, the shift forks 62 are moved in the axial direction of the shift barrel 70 along the groove shape of the shift grooves 76. Furthermore, when the shift forks 62 are moved in the axial direction of the shift barrel 70, the switching mechanism 36 is moved in conjunction with the shift forks 62 toward the rotation axis CL2. The shift grooves 76 each have a different shape relative to the position in the circumferential direction of the shift barrel 70. The shape of the shift grooves 76 is formed so that the transmission 26 sequentially shifts between reverse gear Rev and sixth gear 6th as the shift barrel 70 rotates.

[0025] The transmission 26 is shifted to a plurality of gear stages by switching the engagement / disengagement state of the dog clutch 50 as the switching mechanism 36 moves to respective specified positions in the direction of the rotation axis CL2 in accordance with the rotation of the shift barrel 70. The engagement / disengagement states of the dog clutch 50 include a connected state (synonymous with an engaged state) in which power transmission between the drive gear 32 and the C shaft 52 is possible, and a disconnected state (synonymous with a disengaged state) in which power transmission between the drive gear 32 and the C shaft 52 is disconnected.

[0026] Power is transmitted between the C shaft 52 and the LS differential 58 via a final drive shaft (hereinafter referred to as the FD shaft) 56. The C shaft 52 and the FD shaft 56 are connected by spline fitting (spline fitting portion 54), and the FD shaft 56 and the LS differential 58 are connected by meshing between a drive gear 56a and a final gear 58a.

[0027] The vehicle 10 further includes an electronic control device 80 as a controller including control devices of the vehicle 10 related to the control of the engine 12 and the power transmission unit 16. The electronic control device 80 includes a so-called microcomputer.

[0028] The electronic control device 80 is supplied with various signals based on detection values ​​from various sensors provided in the vehicle 10. The various sensors include, for example, an engine rotation speed sensor 90, an input rotation speed sensor 92, an output rotation speed sensor 94, and an accelerator opening sensor 96. The various signals include, for example, an engine rotation speed Ne, an input rotation speed Ni, an output rotation speed No, and an accelerator opening θacc. The output rotation speed No is a rotation speed corresponding to the vehicle speed V.

[0029] The electronic control device 80 outputs various command signals to each device provided 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, an engine control command signal Se, a K1 hydraulic control command signal Sk1, and a barrel control command signal Sbrl. The barrel control command signal Sbrl is a control command signal for driving the shift barrel 70 to rotate.

[0030] The electronic control unit 80 calculates the required drive torque Trdem by, for example, applying the accelerator opening θacc and the vehicle speed V to a predetermined drive demand amount map. The electronic control unit 80 outputs an engine control command signal Se for obtaining the engine torque Te that realizes the required drive torque Trdem, taking into account the gear ratio γ of the transmission 26 and the like. The electronic control unit 80 also determines whether to shift the transmission 26 using, for example, a predetermined shift map, and outputs a barrel control command signal Sbrl for rotating the shift barrel 70 to execute shift control of the transmission 26 as necessary.

[0031] Incidentally, for example, when deploying to a different vehicle model, if the arrangement of gears in 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 were formed integrally with the shift barrel 70 as a part of the shape that constitutes the shift barrel 70, so the shift barrel 70 had to be redesigned and remanufactured depending on the changes, resulting in issues such as increased man-hours and time. In addition, because the shift barrel 70 is a dedicated part for that vehicle model, there were also issues in terms of parts standardization.

[0032] Therefore, in this embodiment, the arrangement of the gears can be easily changed by using the configuration of the shift barrel 70 shown in Figure 2. Figure 2 is a perspective view illustrating the configuration of the shift barrel 70.

[0033] 2, the shift barrel 70 includes a barrel shaft 72 that is coupled to the shift actuator 66 and that is rotatable about a rotation axis CL3, and four cylindrical barrel rings 74 (74a, 74b, 74c, 74d). As shown in FIG. 2, the barrel rings 74 (74a, 74b, 74c, 74d) each have a shift groove 76 (76a, 76b, 76c, 76d) formed on the outer periphery, and are fixed to the barrel shaft 72 so as to be rotatable integrally therewith. The barrel rings 74 are fixed to the barrel shaft 72 by a suitable method, such as shrink fitting or press fitting.

[0034] Furthermore, for example, all four barrel rings 74 (74a, 74b, 74c, 74d) shown in this embodiment are not necessarily required, and only necessary portions may be provided. The portions that do not require modification may be mixed with the shift grooves 76 formed in the shift barrel 70, for example.

[0035] As described above, according to this embodiment, the shift barrel 70 includes the barrel shaft 72 and the cylindrical barrel ring 74. The barrel ring 74 has shift grooves 76 formed on its outer periphery and is fixed to the barrel shaft 72 so as to be rotatable integrally with it. This allows the arrangement of the barrel ring 74, which has shift grooves 76 corresponding to the transmission gears, to be changed in accordance with a change in the arrangement of the transmission gears, making it easy to change the arrangement of the transmission gears. Furthermore, the barrel shaft 72 and the barrel ring 74 can be made standard components.

[0036] Although the embodiments of the present invention have been described in detail above with reference to the drawings, the present invention can be embodied in various forms with various modifications and improvements based on the knowledge of those skilled in the art. [Explanation of symbols]

[0037] 26: Transmission (vehicle dog-type transmission) 34: Driven gear (speed change gear) 36: Switching mechanism 52: Countershaft (rotating shaft) 60: Shift mechanism 66: Shift actuator 70: Shift barrel 72: Barrel shaft 74: Barrel ring 76: Shift groove CL3: Rotation axis

Claims

[Claim 1] a rotating shaft; a plurality of speed change gears provided on the rotating shaft so as to be rotatable relative to the rotating shaft; a plurality of switching mechanisms arranged adjacent to the speed change gears in the axial direction of the rotating shaft and capable of switching between a connected state in which the speed change gears and the rotating shaft rotate integrally and a disconnected state in which the speed change gears and the rotating shaft rotate relative to each other; and a shift mechanism that moves the switching mechanisms in the axial direction of the rotating shaft, The shift mechanism includes a shift barrel having a shift groove that defines a position of the switching mechanism, and a shift actuator that rotates the shift barrel, A dog-type transmission for a vehicle in which the switching mechanism is moved in the axial direction of the rotary shaft in accordance with rotation of the shift barrel, thereby shifting to a plurality of gear stages, The shift barrel includes a barrel shaft and a cylindrical barrel ring. The barrel ring has the shift groove formed on its outer periphery and is fixed to the barrel shaft so as to be integrally rotatable. A dog-type transmission for a vehicle.

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