JP7103024B2 - Control device for automatic transmission - Google Patents

Description

The present invention relates to a control device for an automatic transmission.

Patent Document 1 describes a first torque transmission path by a belt-type stepless transmission, a second torque transmission path by a gear mechanism provided in parallel with the stepless transmission, a gear mechanism, and a drive wheel of a vehicle. It has a synchro mechanism that connects and disconnects the torque transmission path between them, engages the synchro mechanism in the gear traveling mode, and releases the synchro mechanism in the belt traveling mode to release the first torque transmission path and the second torque transmission path. A control device for an automatic transmission that switches a torque transmission path between and is disclosed. In the control device of this automatic transmission, when the traveling acceleration of the vehicle is large by switching from the gear traveling mode to the belt traveling mode, the difference in the input shaft rotation speed is reduced by selecting a longer shifting time. It is said that switching with less torque fluctuation of the output shaft and less so-called shift shock is possible.

JP-A-2017-187080

In switching from the belt traveling mode to the gear traveling mode, the synchro mechanism is engaged when the vehicle speed is less than a predetermined value in the belt traveling mode in order to improve the shift response. Therefore, when the synchro mechanism is engaged, the driving force changes due to the change in the inertia torque, which makes the driver feel uncomfortable.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a control device for an automatic transmission capable of suppressing a change in driving force when the synchro mechanism is engaged and reducing a sense of discomfort in the driver. To provide.

In order to solve the above-mentioned problems and achieve the object, the control device for the automatic transmission according to the present invention includes a belt-type stepless transmission, a gear mechanism provided in parallel with the stepless transmission, and a gear mechanism. It is equipped with a synchro mechanism that switches between an engaged state and an released state by hydraulic pressure from a hydraulic pressure supply means, and has a belt traveling mode in which power is transmitted via the stepless transmission and power is transmitted via the gear mechanism. It is a control device of an automatic transmission that has a gear traveling mode and engages the synchronization mechanism when the vehicle speed is less than a predetermined value in the belt traveling mode, and decelerates in the belt traveling mode. The predetermined value is set according to the above, and the predetermined value is set to a larger value as the deceleration becomes larger. When the deceleration is equal to or less than the predetermined deceleration, the predetermined value is set to the gear in the gear mechanism. It is characterized in that the meshing noise is set to a value that does not match the resonance point of the peripheral component .

The control device for the automatic transmission according to the present invention has the effect of suppressing a change in driving force when the synchronization mechanism is engaged and reducing a sense of discomfort in the driver.

FIG. 1 is a skeleton diagram showing a schematic configuration of a vehicle provided with a control device for an automatic transmission according to an embodiment. FIG. 2 is a diagram showing the relationship between the synchro engagement vehicle speed and the acceleration in the synchro engagement control in the belt traveling mode. FIG. 3 is a flowchart showing an example of synchro engagement control in the belt traveling mode implemented by the ECU. FIG. 4 is a diagram showing the relationship between the rotation speed at which the engagement of the synchro mechanism is started in the synchro engagement control in the belt traveling mode and the deceleration.

Hereinafter, an embodiment of the control device for the automatic transmission according to the present invention will be described. The present invention is not limited to the present embodiment.

FIG. 1 is a skeleton diagram showing a schematic configuration of a vehicle including the drive transmission device 1 according to the embodiment. The drive transmission device 1 transmits power from the engine 2, which is an internal combustion engine, toward the drive wheels 7L and 7R. The drive transmission device 1 includes a torque converter 3, a forward / backward switching device 4 constituting an automatic transmission 110, a belt-type continuously variable transmission 5, a gear mechanism 6, an output shaft 8, a differential device 9, and the like. There is.

The drive transmission device 1 is provided in parallel with a first power transmission path that transmits power by meshing gears and a second power transmission path that transmits power by a continuously variable transmission 5. Specifically, in the first power transmission path, the torque output from the engine 2 is input to the turbine shaft 31 via the torque converter 3, and this torque is transmitted from the turbine shaft 31 to the forward / backward switching device 4 and the gear mechanism 6. It is transmitted to the output shaft 8 via the output shaft 8. On the other hand, in the second power transmission path, the torque input to the turbine shaft 31 is transmitted to the output shaft 8 via the continuously variable transmission 5. Then, the power transmission path is switched between the first power transmission path and the second power transmission path according to the traveling state of the vehicle.

The torque converter 3 includes a pump impeller 32 connected to the crank shaft of the engine 2 and a turbine impeller 33 connected to the forward / reverse switching device 4 via the turbine shaft 31. A lockup clutch 34 is provided between the pump impeller 32 and the turbine impeller 33.

The forward / backward switching device 4 includes a forward clutch C1, a reverse brake B1, and a double pinion type planetary gear device 41. The carrier 42 of the planetary gear device 41 is integrally connected to the turbine shaft 31 and the input shaft 51 of the continuously variable transmission 5, the ring gear 43 is selectively connected to the housing 11 via the reverse brake B1, and the sun gear 44 is It is connected to the small diameter gear 61. Further, the sun gear 44 and the carrier 42 are selectively connected via the forward clutch C1.

The gear mechanism 6 includes a small-diameter gear 61 and a large-diameter gear 63 that meshes with the small-diameter gear 61 and is provided on the first counter shaft 62 so as not to rotate relative to each other. An idler gear 64 is provided around the same rotation axis as the first counter shaft 62 so as to be rotatable relative to the first counter shaft 62. Further, a synchronization mechanism S1 for selectively connecting and disconnecting the first counter shaft 62 and the idler gear 64 is provided. The synchronization mechanism S1 includes a first gear 65 formed on the first counter shaft 62, a second gear 66 formed on the idler gear 64, and a spline capable of meshing with the first gear 65 and the second gear 66. It includes a sleeve 67 on which teeth are formed. The sleeve 67 meshes with the first gear 65 and the second gear 66 to connect the first counter shaft 62 and the idler gear 64. The synchronization mechanism S1 is in an engaged state in which the sleeve 67 meshes with the first gear 65 and the second gear 66 by the hydraulic pressure from the mechanical oil pump 70, which is a hydraulic pressure supply means driven by the power from the engine 2. The sleeve 67 can be switched to an released state in which at least one of the first gear 65 and the second gear 66 is not meshed with each other. Further, the magnitude of the hydraulic pressure supplied from the mechanical oil pump 70 to the synchronization mechanism S1 is controlled by the hydraulic pressure control device 20.

The idler gear 64 is meshed with an input gear 68 having a diameter larger than that of the idler gear 64. The input gear 68 is provided so as not to rotate relative to the output shaft 8 arranged on the rotation axis common to the rotation axis of the secondary pulley 53 of the continuously variable transmission 5. The output shaft 8 is rotatably arranged around the center of the rotation axis, and the input gear 68 and the output gear 81 are provided so as to be relatively non-rotatable. When the forward clutch C1 and the synchro mechanism S1 are engaged together and the belt traveling clutch C2, which will be described later, is released, the torque of the engine 2 causes the turbine shaft 31, the forward / backward switching device 4 and the gear mechanism 6 to be released. A first power transmission path is formed which is transmitted to the output shaft 8 via the engine.

The stepless transmission 5 is provided on a power transmission path between the input shaft 51 and the output shaft 8 connected to the turbine shaft 31, and is provided with a primary pulley 52 which is an input side member provided on the input shaft 51. A secondary pulley 53, which is an output side member, and a transmission belt 54 wound between the primary pulley 52 and the secondary pulley 53 are provided, and the friction between the primary pulley 52 and the secondary pulley 53 and the transmission belt 54 is provided. Power is transmitted via force.

The primary pulley 52 has a fixed sheave 52a fixed to the input shaft 51, a movable sheave 52b provided so as not to rotate relative to the input shaft 51 and to move in the axial direction, and between them. It is provided with a primary side hydraulic actuator 52c that generates a thrust for moving the movable sheave 52b in order to change the V-groove width. Further, the secondary pulley 53 has a fixed sheave 53a, a movable sheave 53b provided so that it cannot rotate relative to the fixed sheave 53a and can move in the axial direction, and a V-groove width between them. It is configured to include a secondary hydraulic actuator 53c that generates thrust to move the movable sheave 53b to change. Then, the gear ratio can be continuously changed by changing the V-groove width of the primary pulley 52 and the secondary pulley 53 and changing the hook diameter (effective diameter) of the transmission belt 54.

Further, a belt traveling clutch C2 is provided between the continuously variable transmission 5 and the output shaft 8 to selectively disconnect and disconnect between them. Then, when the belt traveling clutch C2 is engaged and the forward clutch C1 is released, the torque of the engine 2 is transmitted to the output shaft 8 via the input shaft 51 and the continuously variable transmission 5. A second power transmission path is formed.

The output gear 81 is meshed with a large diameter gear 92 fixed to the second counter shaft 91. The second counter shaft 91 is provided with a small diameter gear 94 that meshes with the differential ring gear 93 of the differential device 9.

In the gear traveling mode in which torque is transmitted by the first power transmission path, the forward clutch C1 and the synchronization mechanism S1 are engaged, while the belt traveling clutch C2 and the reverse brake B1 are released. Further, in the belt traveling mode in which torque is transmitted by the second power transmission path, the belt traveling clutch C2 is engaged, while the forward clutch C1, the reverse brake B1 and the synchro mechanism S1 are released. The gear ratio of the gear mechanism 6 is set to a gear ratio larger than the maximum gear ratio γ _max of the continuously variable transmission 5.

Further, the ECU 100, which is a control device provided in the vehicle, is provided with a CPU for performing arithmetic processing, a ROM for storing a processing program, a RAM for temporarily storing data, and the like, for example, depending on the traveling range. Control of the automatic transmission 110, the hydraulic control device 20, and the like is performed.

Here, in the automatic transmission 110 according to the embodiment, the vehicle speed is less than a predetermined value (synchronized engaging vehicle speed) during the belt traveling mode in order to improve the shift response in switching from the belt traveling mode to the gear traveling mode. In the case of, the synchronization mechanism S1 is engaged. Then, as shown in FIG. 2, in the belt traveling mode, a predetermined value (synchro engaging vehicle speed) of the vehicle speed that engages the synchro mechanism S1 is variable according to the acceleration. In FIG. 2, with respect to the graph shown by the solid line, the side where the vehicle speed is low is the engaged state of the synchro mechanism S1 (ON in FIG. 2), and the side where the vehicle speed is high is the released state of the synchro mechanism S1 (FIG. 2). Inside OFF). Further, the broken line graph in FIG. 2 shows a case where the predetermined value (synchro engagement vehicle speed) is constant regardless of acceleration. Then, in the present embodiment, when the belt is running, the synchro engagement hydraulic pressure is made variable according to the acceleration so that the engagement of the synchro mechanism S1 is completed in a short time.

FIG. 3 is a flowchart showing an example of synchro engagement control in the belt traveling mode implemented by the ECU 100.

First, the ECU 100 calculates the acceleration-corrected synchro engaging vehicle speed (spd1) (step S1). At this time, the ECU 100 sets the synchro release vehicle speed with respect to the acceleration-corrected synchro engagement vehicle speed (spd1). Next, the ECU 100 determines whether the current vehicle speed is equal to or higher than the acceleration-corrected synchro engaging vehicle speed (spd1) (step S2). When it is determined that the current vehicle speed is equal to or higher than the acceleration-corrected synchro engaging vehicle speed (spd1) (No in step S2), the ECU 100 returns to the process of step S1. On the other hand, when it is determined that the current vehicle speed is less than the acceleration-corrected synchro engaging vehicle speed (spd1) (Yes in step S2), the ECU 100 calculates the synchro engaging hydraulic pressure (synchro engaging thrust) according to the acceleration. (Step S3). Then, the ECU 100 controls the hydraulic pressure control device 20 to supply hydraulic pressure from the mechanical oil pump 70 to the synchro mechanism S1 so as to have the calculated synchro engaging hydraulic pressure, and engage the synchro mechanism S1 (step S4). ), Ends a series of controls.

Since the ECU 100 according to the embodiment can perform appropriate synchro engagement control according to the acceleration by changing the predetermined value or the synchro engagement hydraulic pressure according to the acceleration, when the synchro mechanism S1 is engaged. It is possible to suppress the change in the driving force in the vehicle and reduce the discomfort of the driver.

FIG. 4 is a diagram showing the relationship between the rotation speed Ne that starts the engagement of the synchronization mechanism S1 in the synchronization engagement control in the belt traveling mode and the deceleration G. The vertical axis of FIG. 4 is the rotation speed Ne, and the horizontal axis of FIG. 4 is the deceleration G. In FIG. 4, the "rotation speed" is, for example, the rotation speed of the input gear 68 detected by the rotation speed detection sensor (not shown), the engine rotation speed detected by the engine rotation speed detection sensor (not shown), or the like. Even if the number of revolutions is the same, the corresponding vehicle speed is the same. Therefore, the vertical axis of FIG. 4 may be the vehicle speed instead of the rotation speed Ne. At this time, the vehicle speed may be detected by, for example, a vehicle speed sensor (not shown), calculated by calculation based on the rotation speed of various gears, the engine rotation speed, or the like, or a known method may be applied. Further, in FIG. 4, the solid line graph shows an example of the present invention, and the dotted line graph shows a conventional example.

In the conventional example, as shown in the dotted line graph shown in FIG. 4, the rotation speed Ne that engages the synchronization mechanism S1 is determined according to the deceleration G. However, if the synchronization mechanism S1 is started to engage when the rotation speed is too small, meshing noise between the idler gear 64 and the input gear 68 may occur. Further, when the meshing noise matches the resonance point of peripheral parts such as a case and a mount constituting the automatic transmission 110, the noise is exacerbated. Therefore, in the automatic transmission 110 according to the embodiment, the deceleration G and the rotation speed Ne or the vehicle speed are detected, and the synchronization mechanism S1 is engaged at the optimum timing capable of suppressing the generation of the meshing noise. As described above, the ECU 100 can perform synchro engagement control. Specifically, as shown in the solid line graph shown in FIG. 4 of the example of the present invention, when the current deceleration G is equal to or less than the predetermined deceleration G1, the synchronization mechanism S1 is performed at the predetermined rotation speed Ne1 (predetermined vehicle speed). Start engaging. As a result, it is possible to suppress the generation of meshing noise between the idler gear 64 and the input gear 68. Further, since the synchronization mechanism S1 is engaged while avoiding the resonance point of the peripheral component, it is possible to suppress that the meshing noise matches the resonance point of the peripheral component and the noise is deteriorated, so that the noise is quiet. It becomes possible to secure it.

Further, since the synchronization mechanism S1 starts engaging at high speed during sudden deceleration, it is possible to ensure downshift reacceleration. On the other hand, during slow deceleration such as when the brake is fully closed, the synchronization mechanism S1 starts engaging at a lower speed, so that fuel efficiency can be improved.

1 Drive transmission device 2 Engine 3 Torque converter 4 Forward / backward switching device 5 Continuously variable transmission 6 Gear mechanism 7L, 7R Drive wheels 8 Output shaft 9 Differential device 100 ECU
110 Automatic transmission S1 Sync mechanism

Claims (1)

With a belt-type continuously variable transmission,
A gear mechanism provided in parallel with the continuously variable transmission and
It is equipped with a synchronization mechanism that can switch between the engaged state and the disengaged state by the hydraulic pressure from the hydraulic pressure supply means.
It has a belt traveling mode in which power is transmitted via the continuously variable transmission and a gear traveling mode in which power is transmitted via the gear mechanism.
A control device for an automatic transmission that engages the synchronization mechanism when the vehicle speed is less than a predetermined value in the belt traveling mode.
In the belt traveling mode, the predetermined value is set according to the deceleration , the predetermined value is set to a larger value as the deceleration becomes larger, and when the deceleration is equal to or less than the predetermined deceleration, the predetermined value is set. A control device for an automatic transmission, wherein the value is set to a value at which the meshing noise of the gears in the gear mechanism does not match the resonance points of peripheral parts .

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