JP6565008B2 - Automatic transmission - Google Patents

Description

  The present invention relates to an automatic transmission having a dog clutch.

  In Patent Document 1, in a mouse tooth type electromagnetic clutch, if a mouse tooth phase is shifted, a shock is generated at the time of engagement. Therefore, one of the tooth teeth is driven to rotate by a motor and is synchronized with the other tooth tooth. Thus, proper engagement is performed.

JP 7-269603 A

However, it is necessary to provide a separate motor for rotation driving for synchronization, and there is a problem that the cost increases and the size increases.
An object of the present invention is to provide an automatic transmission that can be synchronized without using a dedicated actuator such as a motor when synchronizing a dog clutch.

To achieve the above object, in the automatic transmission according to the present invention, a first shaft connected to the internal combustion engine via a clutch ,
A first gear supported on the first shaft so as to be relatively rotatable;
A second gear fixedly supported on the second shaft and constantly meshing with the first gear;
A clutch ring dog meshing with the dog of the first gear by movement toward the axial meshing side;
An actuator that moves the clutch ring dog in an axial direction to control meshing with the dog;
An on / off state determination means for determining whether or not the teeth of the dog and the clutch ring dog face each other and cannot engage with each other;
When the rotation of the first shaft and second shaft engaging the said dog and said clutch ring dog in a state of stopping only when it is determined that the inflow is not state by the inflow unsaturated state detecting means, Synchronizing means for connecting the clutch and rotating the first shaft using the torque of the internal combustion engine ;
Equipped with.

  Therefore, even when the vehicle is stopped, the dogs can be engaged without mounting a synchronization motor or the like, so that the degree of freedom in layout can be improved, the cost can be reduced, and an increase in weight can be avoided.

1 is a schematic system diagram illustrating an automatic transmission according to a first embodiment. 3 is a flowchart illustrating an entry non-resolving control process according to the first embodiment. It is a time chart showing the shift state in which the incompletion does not arise at the time of the shift to the 1st speed while the vehicle is stopped according to the first embodiment. 6 is a time chart showing an entry non-resolving control process when a non-entry occurs when shifting to the first speed while the vehicle is stopped according to the first embodiment. 6 is a time chart showing an entry non-resolving control process when a non-entry occurs when downshifting while the vehicle is stopped from sudden deceleration according to the first embodiment.

[Example 1]
FIG. 1 is a schematic system diagram showing an automatic transmission according to a first embodiment. A clutch 2 is connected to the engine output shaft of the engine 1. The clutch 2 is a dry clutch, and the position of the clutch plate is controlled by the clutch actuator 2a. The clutch actuator 2a controls the position of the clutch piston that presses the clutch plate in accordance with the requested torque transmission capacity, and performs slip control for transmitting torque while allowing relative rotation of the clutch 2, and relative rotation of the clutch 2. Perform full fastening control that is not allowed. The clutch actuator 2a has a piston stroke sensor 11 that detects the stroke position of the clutch piston, and controls the torque transmission capacity based on the detected stroke position.

  Connected to the output side of the clutch 2 is an automatic transmission 3 that shifts the input rotation and outputs it to the drive wheels 4. The automatic transmission 3 has a first shaft 3a connected to the automatic transmission side of the clutch 2 and a second shaft 3b arranged in parallel with the first shaft 3a. On the 1st shaft 3a, it has the 1st speed drive gear 31 and the 2nd speed drive gear 32 supported so that relative rotation with respect to the 1st shaft 3a was possible. On the second shaft 3b, there are a first speed driven gear 33 fixed to the second shaft 3b and rotating integrally with the second shaft 3b, and a second speed driven gear 34. Each driven gear always meshes with each drive gear. Although not shown in the drawings, when configuring a forward four-speed automatic transmission, a third-speed drive gear, a third-speed driven gear, a fourth-speed drive gear, and a fourth-speed driven gear may be mounted similarly to the first-speed and second-speed. , Not specifically mentioned.

  A side surface of the first drive gear 31 has a first dog 31a extending in the axial direction. A side surface of the second drive gear 32 has a second dog 32a extending in the axial direction. The first speed drive gear 31 and the second speed drive gear 32 have first and second dog clutch mechanisms. The first dog clutch mechanism has a first clutch ring 311 that is fixedly installed on the first shaft 3 a and meshes with the first shift fork 310 so as to be relatively rotatable. Similarly, the second dog clutch mechanism also has a second clutch ring 321.

  The first clutch ring 311 is a disc-like member that can be applied to the first shift fork 310 while being held rotatably relative to the first shift fork 310. The first clutch ring 311 has a first-speed first clutch ring dog 311 a extending in the axial direction of the side surface facing the first-speed drive gear 31. Similarly, the second clutch ring 321 is a disk-shaped member that can be applied to the second shift fork 320 and an axial force while being held rotatably relative to the second shift fork 320. The second clutch ring 321 has a second-speed second clutch ring dog 321a that extends in the axial direction on the side surface facing the second-speed drive gear 32.

  At the first speed, the first shift fork 310 is moved to the right side in FIG. 1, the first clutch ring 311 is moved to the right side, and the first clutch ring dog 311a for the first speed and the first dog of the first speed drive gear 31 are moved. Engage with 31a to achieve 1st gear. During the upshift from the first speed to the second speed, the first shift fork 310 is moved to the left side in FIG. 1 to release the engagement between the first clutch ring dog 311a for the first speed and the first dog 31a, By moving the second shift fork 320 to the right in FIG. 1, the second clutch ring dog 321a for the second speed and the second dog 32a are meshed to achieve the second speed.

  The shift actuator 5 is configured to be able to move the first shift fork 310 and the second shift fork 320 in the axial direction. The shift actuator 5 has a shift drum 50 having shift grooves 51 and 52 that engage with the shift forks 310 and 320 on the outer periphery. The shift grooves 51 and 52 are formed to be movable in the axial direction of the shift forks 310 and 320 as the shift drum 50 rotates, and the shift motor 53 controls the rotational position of the shift drum 50 to change the speed. Do.

  The transmission controller 30 includes an engine speed sensor 10 that detects the engine speed, an input speed sensor 12 that detects the speed of the first shaft 3a, and a shift stroke that detects the stroke positions of the shift forks 310 and 320. The sensor 13, the current sensor 14 for detecting the current value of the shift motor 53, the output rotational speed sensor 15 for detecting the rotational speed of the second shaft 3b, and the shift lever 7 for selecting the P, R, N, D range Based on the shift signal, a desired gear position is determined, and the drive current Is is output to the shift motor 53 of the shift actuator 5.

  Here, a problem when the dog clutch is engaged will be described. The first clutch ring dog 311a for first speed and the first dog 31a (hereinafter also referred to as both dogs) are a plurality of dog teeth arranged at equal positions on the circumference and a recess formed between the dog teeth. Have When both dogs approach the axial direction and the dog teeth of one dog enter the recess of the other dog, the dog teeth are alternately arranged on the circumference. Thereby, torque is transmitted from one dog to the other dog. At this time, even if one dog tooth and the other dog tooth are close to each other on the circumference, the dog teeth interfere with each other and cannot approach the axial direction. If it does so, both dog teeth cannot be located in a line by turns and a dog clutch cannot be fastened. This state is referred to as an inactive state.

  If both dogs are brought close to the axial direction while the first shaft 3a or the second shaft 3b is rotating, a relative rotation occurs between the first clutch ring dog 311a for the first speed and the first shaft 3a. Even if an incomplete state occurs, the dogs can be engaged with each other because the relative rotational positions of the dogs are shifted. However, when the vehicle is stopped and the clutch 2 is released, both the first shaft 3a and the second shaft 3b are in a stopped state. In this case, if the gear shifts from the neutral state to the first gear in preparation for a start, and the incompletion state occurs, the relative rotational positions of the two dogs cannot be shifted, and the incompletion state cannot be eliminated. There is.

  In order to eliminate this state, it is conceivable to provide a synchronization motor or the like for applying a rotational force to one of the shafts. Since the inertia increases, there is a possibility that the transmission quality may be deteriorated. Therefore, in the first embodiment, the clutch 2 is slightly engaged and the first shaft 3a is rotated by the driving force of the engine 1 to eliminate the incompletion state.

  (Non-resolving control process)

FIG. 2 is a flowchart illustrating the entry non-resolving control process according to the first embodiment. The entry non-resolving control process is executed in the transmission controller 30.
In step S1, 3 determines whether the vehicle is stopped and the rotation of the first shaft 3a is stopped. Specifically, it is determined whether or not both of the rotation speeds detected by the output rotation speed sensor 15 and the input rotation speed sensor 12 are 0 rpm. If it is determined that the rotation speed is 0 rpm, the process proceeds to step S2. End the control flow.
In step S2, based on the shift request, a drive command is output to the shift motor 53 so that the rotational position of the shift drum 50 becomes a desired gear position.

  In step S3, it is determined whether or not the drive current Is of the shift motor 53 is greater than or equal to the input current I1 that is greater than a predetermined current generated by the rotation of the shift drum 50. Then, the process proceeds to step S6. Otherwise, it is determined that there is a possibility of no entry and the process proceeds to step S4. In other words, if the shift fork cannot enter, the shift drum 50 cannot rotate because the shift fork cannot move in the axial direction. Then, even if it tries to move to the rotational position corresponding to the desired gear position, the drive load of the shift motor 53 increases, and the drive current Is increases. Utilization of this characteristic is used to determine whether the drive current Is is present.

  In step S4, it is determined whether or not the shift stroke amount Str detected by the shift stroke sensor 13 is equal to or less than the input non-stroke amount Str0 representing the non-entering stroke amount. If the shift stroke amount Str is greater than the non-stroke amount Str0, it is determined that the shift forks 31 and 32 are firmly stroked, and the process proceeds to step S6. Therefore, it is possible to determine the incompletion state based on both the current value of the shift motor 53 and the detected values of the shift stroke sensor 13, and the accuracy of the incompletion state determination can be improved.

In step S5, ON / OFF control of the clutch 2 is performed. Specifically, in the clutch actuator 2a, the piston stroke position detected by the piston stroke sensor 11 is controlled to be a predetermined position representing a state where the distance between the clutch plates is slightly in contact with the first shaft 3a. A predetermined torque transmission capacity necessary for rotating the gear is generated a plurality of times (for example, about twice) to synchronize the dog teeth.
In step S6, it is determined whether or not the shift stroke amount Str detected by the shift stroke sensor 13 is greater than or equal to the completed stroke amount Str1 representing the completion of the shift. If it is greater than or equal to the completed stroke amount Str1, it is determined that the shift has been completed. When the control flow ends, and when it is less than the completed stroke amount Str1, it is determined that the shift is not completed, the process returns to step S3, and the subsequent steps are repeated.

  FIG. 3 is a time chart showing a shift state in which there is no entry failure when shifting to the first speed while the vehicle is stopped according to the first embodiment. The engine 1 is in an operating state, the vehicle is stopped, and the clutch 2 is in a fully engaged state. When the driver operates the shift lever 7 from this state and operates from the P range to the N range and further to the D range, the clutch 2 is released at time t1 to prepare for the start. Thereby, the rotation speed of the first shaft 3a gradually decreases while inertially rotating.

At time t2, the shift motor 53 is driven and the shift drum 50 rotates, whereby the first shift fork 310 starts a stroke. At this time, since no imperfection occurs, the shift drum 50 rotates smoothly, and the drive current Is rises to the normal drive current In, but does not rise to the enter noncurrent I1. Then, the shift stroke amount Str increases, and the shift to the first speed is completed smoothly.
As described above, when the incompletion state is not detected, the clutch ON / OFF control is not performed, and the sound vibration performance is not deteriorated and the engagement shock is not caused.

FIG. 4 is a time chart showing an entry non-resolving control process in the case where an entry failure occurs during the shift to the first speed while the vehicle is stopped according to the first embodiment. Since the time chart until time t2 is the same as the time chart shown in FIG.
If entry failure occurs at time t21, the first shift fork 310 cannot make a sufficient stroke, and the shift drum 50 cannot rotate smoothly, so that the drive current Is starts to rise.
At time t22, since the drive current Is enters and exceeds the non-current I1, and the shift stroke amount Str is equal to or less than the input non-stroke amount Str0, the clutch ON / OFF control is started. Thereby, the torque transmission capacity necessary for rotating the first shaft 3a to the clutch 2 is given a plurality of times, and the first shaft 3a rotates. As a result, the first clutch ring dog 311a for first speed rotates and starts relative rotation with the first dog 31a.
When the first clutch ring dog 311a for first speed and the first dog 31a are engaged at time t23, the shift stroke amount Str is increased, and the shift to the first speed can be completed.

FIG. 5 is a time chart showing an entry non-resolving control process in the case where an entry failure occurs when downshifting while the vehicle is stopped from the sudden deceleration of the first embodiment.
If the driver starts sudden braking at time t31 while traveling at the 3rd speed, the speed change is not in time and the speed is reduced at the 3rd speed. At time t32, the clutch 2 is released to avoid engine stall, and the vehicle stops at time t33. Thereafter, a downshift is started from the third speed to the second speed and the first speed to prepare for the next start.

At time t34, a downshift from the 3rd speed to the 2nd speed is started, and the shift drum 50 is rotated and enters a non-state. Therefore, the drive current Is starts to increase from time t35.
At time t36, since the drive current Is enters and exceeds the non-current I1, and the shift stroke amount Str is equal to or less than the non-stroke amount Str0, the clutch ON / OFF control is started. As a result, the torque transmission capacity necessary for rotating the first shaft 3a is applied to the clutch 2 a plurality of times, and the second-speed second clutch ring dog 321a and the second dog 32a mesh with each other at time t37.

At time t38, a downshift from the 2nd speed to the 1st speed is started and the shift drum 50 is rotated to enter the non-state. Therefore, the drive current Is starts to increase from time t39.
At time t40, the driving current Is enters and exceeds the non-current I1, and the shift stroke amount Str is less than the non-stroke amount Str0, so the clutch ON / OFF control is started. As a result, the torque transmission capacity necessary for rotating the first shaft 3a is applied to the clutch 2 a plurality of times, and the first-speed first clutch ring dog 311a and the first dog 31a mesh with each other at time t41. Therefore, even when the vehicle is in a stopped state, a downshift can be achieved regardless of the occurrence of no entry.

As described above, the effects listed below are obtained in the first embodiment.
(1) a first shaft 3a connected to the engine 1 (power source);
A first-speed drive gear 31 (first gear) supported on the first shaft 3a so as to be relatively rotatable;
A first-speed driven gear 33 (second gear) fixedly supported by the second shaft 3b and always meshed with the first-speed drive gear 31;
A first-speed first clutch ring dog 311a (clutch ring dog) that meshes with the first dog 31a (dog of the first gear) by movement toward the axial meshing side;
A shift actuator 5 (actuator) that controls the meshing with the first dog 31a by moving the first clutch ring dog 311a for first speed in the axial direction;
The first shaft 3a is rotated using the torque of the engine 1 when the first clutch ring dog 311a for the first speed and the first dog 31a are engaged with each other while the rotation of the first shaft 3a and the second shaft 3b is stopped. A transmission controller 30 (synchronizing means)
Equipped with.

  In other words, even when the rotation of the first shaft 3a or the second shaft 3b is stopped due to the vehicle stop and an incompletion state occurs, the first shaft 3a can be rotated by the engine torque and the dog clutch can be synchronized. Therefore, even when the vehicle is stopped, the dogs can be engaged without mounting a synchronization motor or the like, so that the degree of freedom in layout can be improved, the cost can be reduced, and an increase in weight can be avoided.

(2) The engine 1 is an internal combustion engine,
A clutch 2 is provided between the engine 1 and the first shaft 3a,
The transmission controller 30 synchronizes the dogs by rotating the first shaft 3 a by connecting the clutch 2.
Therefore, the dogs can be meshed in synchronization only by controlling the transmission torque capacity of the clutch 2.

(3) The transmission controller 30 connects and disconnects the clutch 2 with a predetermined torque transmission capacity (a range of a predetermined value or less) that is necessary for the transmission torque capacity of the clutch 2 to rotate the first shaft 3a.
Therefore, since the low transmission torque capacity according to the inertia of the rotating element including the first shaft 3a is provided, it is possible to avoid the deterioration of the sound vibration performance and the occurrence of the fastening shock.

(4) having a shift stroke sensor 13 (stroke amount detecting means) for detecting a stroke amount Str of the first shift fork 310 which is an axial stroke amount of the first clutch ring dog 311a for the first speed;
The transmission controller 30 rotates the first shaft 3a when the stroke amount Str enters and is equal to or less than the non-stroke amount Str0 (predetermined stroke amount).
That is, since the first shaft 3a is rotated by the engine torque after detecting the incompletion state, if the incompletion state does not occur, unnecessary rotation is not given to the first shaft 3a, and the sound is not generated. Deterioration of vibration performance and fastening shock can be avoided.

(5) having a current sensor 14 (current detection means) for detecting the drive current Is of the shift actuator 5;
The transmission controller 30 rotates the first shaft 3a when the drive current Is is greater than the inflow current I1 (predetermined current) greater than the drive current In generated during the normal stroke.
That is, since the first shaft 3a is rotated by the engine torque after detecting the incompletion state, if the incompletion state does not occur, unnecessary rotation is not given to the first shaft 3a, and the sound is not generated. Deterioration of vibration performance and fastening shock can be avoided.

(Other examples)
As described above, the description is based on the first embodiment. However, the present invention is not limited to the above-described embodiment, and the present invention may be applied to an automatic transmission having another configuration. For example, in the first embodiment, a drive gear that is a relative rotating body is arranged on the first shaft 3a, and a dog clutch mechanism that can selectively fix the drive gear to the first shaft 3a is provided. The first shaft 3a is not limited to be provided on the second shaft 3b, or may be set to both the first shaft 3a and the second shaft 3b in combination.
Further, the present invention can be applied not only to the fourth forward speed but also to the second forward speed and further automatic transmissions with multiple stages.
Moreover, although the example which mounted the engine which is an internal combustion engine as a power source was shown in the Example, this invention is applicable also to the hybrid vehicle which uses a drive motor and an engine and a motor together as a power source.

DESCRIPTION OF SYMBOLS 1 Engine 2 Clutch 2a Clutch actuator 3 Automatic transmission 3a 1st shaft 3b 2nd shaft 4 Drive wheel 5 Shift actuator 7 Unexamined-Japanese-Patent No. 7 Shift lever 10 Engine rotational speed sensor 11 Piston stroke sensor 12 Input rotational speed sensor 13 Shift stroke sensor 14 Current sensor 15 Output rotational speed sensor 30 Transmission controller 31 First speed drive gear 31a First dog 32 Second speed drive gear 32a Second dog 33 First speed driven gear 34 Second speed driven gear 50 Shift drum 51, 52 Shift groove 53 Shift motor 310 First shift fork 311 First clutch ring 311a First clutch ring dog 320 for first speed Second shift fork 321 Second clutch ring 321a Second clutch ring dog for second speed

Claims (4)

A first shaft connected to the internal combustion engine via a clutch ;
A first gear supported on the first shaft so as to be relatively rotatable;
A second gear fixedly supported on the second shaft and constantly meshing with the first gear;
A clutch ring dog meshing with the dog of the first gear by movement toward the axial meshing side;
An actuator that moves the clutch ring dog in an axial direction to control meshing with the dog;
An on / off state determination means for determining whether or not the teeth of the dog and the clutch ring dog face each other and cannot engage with each other;
When the rotation of the first shaft and second shaft engaging the said dog and said clutch ring dog in a state of stopping only when it is determined that the inflow is not state by the inflow unsaturated state detecting means, Synchronizing means for connecting the clutch and rotating the first shaft using the torque of the internal combustion engine ;
An automatic transmission characterized by comprising: The automatic transmission according to claim 1 , wherein
The automatic transmission is characterized in that the synchronizing means connects and disconnects the clutch within a range where a transmission torque capacity of the clutch is a predetermined value or less. The automatic transmission according to claim 1 or 2 ,
Stroke amount detecting means for detecting an axial stroke amount of the clutch ring dog;
The automatic transmission is characterized in that the non-entering state determining means determines that the non-entering state is present when the stroke amount is equal to or less than a predetermined stroke amount. The automatic transmission according to any one of claims 1 to 3 ,
Current detection means for detecting the drive current of the actuator;
The automatic transmission is characterized in that the on / off state determination means determines that the on / off state is present when the driving current is equal to or greater than a predetermined current larger than a driving current generated during a normal stroke.

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