JP3996949B2 - Shift-by-wire system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention belongs to a technical field of a shift-by-wire system in which a shift position of an automatic transmission is selected by a motor drive based on electric control and a shift position is determined by a detent mechanism.
[0002]
[Prior art]
Conventionally, as a shift-by-wire system, for example, the one described in JP-A-5-118436 is known. In the shift-by-wire system described in this publication, a gear mechanism is driven by a motor that is driven based on electric control, and a range switching valve of an automatic transmission is switched. FIG. 7 is a schematic diagram of a shift-by-wire system in the prior art. First, the configuration will be described. 100 is a motor, 101 is a worm, 102 is a worm wheel, 103 is a boss portion, 104 is a coupling portion for coupling the worm wheel 102 and the control shaft 131, 110 is an actuator position sensor, and 120 is a valve position. A sensor 130 is a control mechanism.
[0003]
The control mechanism 130 includes a detent lever 132 engaged with the control shaft 131, uneven portions 135 and 136 provided on the detent lever 132, and rollers engaged with the uneven portions 135 and 136 and pressed by the detent spring 133. 134. Further, the shift valve mechanism 140 is engaged with the detent lever 132, and a desired range position can be obtained.
[0004]
Here, FIG. 8 shows an enlarged cross-sectional view of the coupling portion 104. The end 131a of the control shaft 131 has two engaging surfaces 131b formed by chamfering both sides of the outer peripheral surface with a predetermined two-surface width. A predetermined play amount δ is provided between the engagement surface 131b and the inner wall surface 103a of the boss portion 103 with respect to the mutual rotation direction.
[0005]
[Action]
Next, the operation will be described. The motor 100 is driven to drive the worm wheel 102 clockwise, for example, as viewed from the detent mechanism. Since the detent lever 132 is pressed by the detent spring 133, the control shaft 131 does not move, and the worm wheel 102 rotates by the amount of play δ. When the engagement surface 131b contacts the inner wall surface 103a, the control shaft 131 rotates and the detent lever 132 rotates against the pressing force of the detent spring 133. As a result, the roller 134 moves from the concave portion 136 to the convex portion 135. When the roller 134 reaches the top of the convex portion 135, the roller 134 moves to the adjacent concave portion at a stroke by the pressing force of the detent spring 133, and pushes the detent lever 132 in the clockwise direction. As a result, the control shaft 131 is also rotated clockwise more than the rotation input from the worm wheel 102, so that the coupling portion 104 rotates more than the worm wheel 102 by 2δ. When the roller 134 stops at the recess 136, the control shaft 131 is fixed, and the worm wheel 102 further rotates by δ, and stops at a position where a clearance δ is secured on both surfaces of the engagement surface 131b.
[0006]
[Problems to be solved by the invention]
However, the conventional shift-by-wire system has the following problems. That is, it is necessary to set the play δ of the coupling portion 104 provided in the boss portion 103 to an amount corresponding to the movement of the detent mechanism, but since a very delicate movement is required, high machining accuracy is required. As a result, there was a problem that the cost was increased. Further, since the engaging surface 131b and the inner wall surface 103a collide with each other, there are problems that abnormal noise is generated and durability is deteriorated.
[0007]
The present invention has been made paying attention to the above-mentioned problems, and the object thereof is to select a shift position of an automatic transmission by motor drive based on electric control and to determine the shift position by a detent mechanism. An object of the present invention is to provide a shift-by-wire system that does not require high machining accuracy, ensures durability, and can drive a shift actuator without affecting the movement of a detent mechanism.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, according to the first aspect of the present invention, a shift switch that is operated by a driver and outputs a switch signal indicating a shift position corresponding to each range such as a parking range and a drive range, and an automatic transmission are provided. A detent mechanism that is connected to the manual valve and positions the parking rod at a predetermined position; a shift actuator that drives the detent mechanism; and a command for obtaining a shift position indicated by the switch signal by inputting a switch signal of the shift switch. Shift-by-wire system comprising: a shift control means for outputting the shift actuator to the shift actuator; and the shift actuator is connected to a sun gear of a planetary gear mechanism having a sun gear, a pinion carrier, and a ring gear, and connected to the pinion carrier. Consist of a Chueta output shaft, between a housed portion and the ring gear outer periphery which accommodated a ring gear, the ring gear provided rotatable relative play relative to the accommodated section,該Asobi amount, said detent mechanism It is characterized in that it is set in a range that allows the operation by positioning of.
[0009]
In invention of Claim 2, in the shift-by-wire system of Claim 1,
An elastic member is provided between both sides in the circumferential direction of the convex portion provided on the outer periphery of the ring gear and the end portion in the idle circumferential direction.
[0010]
Operation and effect of the invention
In the shift-by-wire system according to claim 1, the shift actuator includes a planetary gear mechanism having a sun gear, a pinion carrier, and a ring gear, drive means coupled to the sun gear, and an actuator output shaft coupled to the pinion carrier. ing. Furthermore, between the outer periphery of the housed portion and a ring gear which accommodated a ring gear, the ring gear is rotatable relative play is provided for accommodated portion. The play amount is set in a range in which an operation due to positioning of the detent mechanism can be permitted.
[0011]
Therefore, even if a rotational force is input to the pinion carrier from the actuator output shaft side due to the positioning operation of the detent mechanism, the ring gear rotates within the play amount of the ring gear, and the input rotation from the pinion carrier is reduced within the planetary gear mechanism. Therefore, the shift actuator can be operated without affecting the input of the driving force from the driving means to the sun gear. This is because the driving force from the detent mechanism is not input to the driving means, and it is only necessary to control the rotation amount without considering the stepwise movement of the detent mechanism. Thus, stable control can be performed.
[0012]
In the prior art, since the play δ is provided at the end of the control shaft, the play δ can only take a value corresponding to the shaft diameter of the shaft, and very delicate processing is required. However, in the present invention, by providing play on the outer periphery of the ring gear, it is possible to make the rotation diameter larger when providing the play amount than in the prior art, and it is only necessary to process the ring gear outer periphery and the receiving portion. Therefore, it can be easily processed.
[0013]
Further, even if the rotational force from the pinion carrier is input by the pressing force of the detent spring, the rotational speed is decelerated, since the input to the ring gear, more during play circumferential end portion of the ring gear outer periphery accommodated portion It is possible to suppress the impact applied to the film, and the durability can be improved.
[0014]
In the invention according to claim 2, the elastic member is provided between both sides in the circumferential direction side surface of the convex portion and the end portion in the play circumferential direction.
That is, in the prior art, since the play δ is provided at the end of the control shaft, the play δ can only take a value corresponding to the shaft diameter of the shaft, and very delicate processing is required. However, in the present invention, by providing play on the outer periphery of the ring gear, it is possible to make a larger rotation diameter when providing play than in the prior art, and an elastic member can be easily provided. As a result, when the convex part rotates in the play, the elastic members provided on both sides of the convex part circumferential side surface absorb the impact, so that the convex part circumferential side surface and the play circumferential end part collide with each other. It is possible to avoid the problem of deterioration of sex.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment for realizing a shift-by-wire system according to the present invention will be described based on a first example corresponding to claims 1 and 2.
[0016]
(First embodiment)
First, the configuration will be described.
FIG. 1 is an overall configuration diagram showing the shift-by-wire system of the first embodiment. In the figure, 1 is an indicator indicating a shift selection position, 2 is a fail lamp for notifying the driver of an abnormality, 3 is an ignition switch, 4 is a shift switch for selecting a shift position, and 5 is a shift lock mechanism. Further, 20 is a shift control unit, 63 is a CVT control unit for controlling the automatic transmission 60, 64 is an engine control unit, 60 is an automatic transmission, 61 is a transmission mechanism, 62 is selected by the automatic transmission. This is an inhibitor switch that outputs a range signal. In the present embodiment, the belt-type continuously variable transmission is mounted on the transmission mechanism 61, but even a stepped transmission can be used without any problem. Reference numeral 30 denotes a shift actuator provided in the vicinity of the inhibitor switch 62, and reference numeral 31 denotes a main motor.
[0017]
FIG. 2 is an overall system diagram showing the shift-by-wire system of the first embodiment. The shift control unit 20 includes a main CPU 21 a that calculates the drive voltage of the main motor 31 and a main driver 21 that supplies the drive voltage calculated by the main CPU 21 a to the main motor 31. Further, a sub CPU 22a is provided, and the main CPU 21a and the sub CPU 22a are configured to always monitor each other and detect an abnormality. Further, the shift control unit 20 receives a signal from the CVT control unit 63 that performs the shift control of the transmission mechanism 61 and outputs a signal to the engine control unit 64.
[0018]
The shift actuator 30 includes a gear mechanism 33 driven by the main motor 31, a temperature sensor 35 that detects the temperature of the main motor 31, and a control shaft that is connected to the gear mechanism 33 and controls a shift range via an inhibitor switch 62. An angle sensor 34 for detecting the rotation angle 36 is provided and driven based on a signal from the shift control unit 20.
[0019]
FIG. 3 is a schematic view showing a detent mechanism in the first embodiment.
First, the configuration will be described. 30 is a shift actuator, and 36 is a control shaft that outputs a driving force from the shift actuator 30, and is engaged with the detent mechanism 70. 71 is a detent lever, 72 is a detent spring, and 73 is a roller. The detent lever 71 is provided with concave and convex portions 71a and 71b with which the roller 73 engages.
[0020]
The detent lever 71 is engaged with a shift valve 74 and a parking mechanism 80. A desired shift range can be obtained by locking the parking gear according to the movement of the detent lever 71 and shifting the shift valve.
[0021]
FIG. 4 is a cross-sectional view of the shift actuator 30 in the first embodiment.
The shift actuator 30 includes a first housing 43, a second housing 44, and a third housing 45. A gear mechanism 33 is housed in the planetary housing chamber A formed between the first housing 43 and the second housing 44, and a worm housing chamber B formed between the second housing 44 and the third housing 45. A worm 31a for inputting a driving force from the main motor 31 and a worm wheel 37 are accommodated.
[0022]
The worm wheel 37 is connected to the input shaft 38, and the rotational driving force of the main motor 31 is transmitted to the planetary chamber A via the input shaft 38. The input shaft 38 is rotatably supported by a bearing 47 c provided in the third housing 45, a ball bearing 47 b provided in the second housing 44 and a ball bearing 47 a provided in the pinion carrier 42. The input shaft 38 has a hollow structure, and a sensor rod 49 connected to the angle sensor 34 and the pinion carrier 42 is provided in the hollow.
[0023]
In the planetary housing chamber A, a sun gear 39 provided on the inserted input shaft 38, a plurality of pinion gears 40 that mesh with the sun gear 39, and the pinion gear 40 mesh with the first and second housings 43 and 44. A fixedly supported ring gear 41 is provided. Further, a pinion carrier 42 that rotatably supports a plurality of pinion gears 40 is provided, and the pinion carrier 42 is provided with an output boss portion 42 a that is connected to the control shaft 36. An oil seal 46 is provided between the output boss portion 42 a and the first housing 43 to make the shift actuator 30 liquid-tight. The pinion carrier 42 is slidably supported via a bearing 48 a provided in the first housing 43 and a bearing 48 b provided in the second housing 44.
[0024]
FIG. 5 is a cross-sectional view of the shift actuator 30 taken along the line CC in the first embodiment. A stopper 41 a is provided on the outer periphery of the ring gear 41. The ring gear 41 is accommodated so that a stopper 41 a can rotate in a play 44 a provided in the second housing 44. The stopper 41a is disposed at the center of the play 44a, and a rotatable region for α is provided on both sides in the circumferential direction of the stopper 41a. Furthermore, elastic members 44b are provided on both sides of the stopper 41a, and the stopper 41a is positioned at the center by pressing the stopper 41a from both sides.
[0025]
Next, the operation will be described.
6A is a time chart showing the rotational speeds of the sun gear 39, the pinion carrier 42 and the ring gear 41 when the shift actuator is operated. FIG. 6B is a schematic diagram of the ring gear operation showing the position of the stopper 41a. FIG. FIG. 6 is a schematic diagram showing the positions of the detent lever 71 and the roller 73, and FIG. 6D is a collinear diagram of the gear mechanism 33. The operation will be described below with reference to FIGS. 6 (a), (b), (c), and (d).
[0026]
Step 1
In a state before the shift actuator 30 is operated, the stopper 41a is positioned at the center of the play 44a, and the roller 73 is positioned at the lowest point 71a of the recess of the detent lever 71.
[0027]
Step 2
The rotational driving force input from the main motor 31 is transmitted from the worm 31a to the worm wheel 37 to drive the input shaft 38. The rotation input to the sun gear 39 provided on the input shaft 38 tries to rotate the pinion carrier 42. However, since the roller 73 is pressed by the detent spring 72, the control shaft 36 is fixed. Therefore, the ring gear 41 rotates counterclockwise in the drawing. That is, it corresponds to step 2 in FIG. 6A, corresponds to a state in which the position of the stopper 41a shifts from (A) to (B) in FIG. 6 (B), and in FIG. Corresponds to the state (a) staying at the recess lowermost point 71a, and corresponds to the state shown in the alignment chart (a) in FIG. 6 (d).
[0028]
Step 3
When the ring gear 41 rotates counterclockwise and the stopper 41 a rotates α, the ring gear 41 is fixed to the second housing 44. At this time, the rotation of the sun gear 39 is transmitted to the pinion carrier 42 and pushes up the roller 73 against the pressing force of the detent spring 72 to rotate the detent lever 71. That is, this corresponds to step 3 in FIG. 6A, corresponds to a state in which the position of the stopper 41a is fixed to (B) in FIG. 6B, and in FIG. This corresponds to the state (a) to (b) where the lower point 71a is shifted to the convex vertex 71b, and corresponds to the state shown in the alignment chart (b) in FIG. 6 (d).
[0029]
Step 4
If the rotation of the roller 73 is continued in Step 3 and the motor is stopped at the position of -α from the position of the concave lowest point 71a, the roller 73 gets over the convex vertex 71b of the detent lever 71. It moves to the next recess lowest point 71a at once by the pressing force of. Therefore, the control shaft 36 rotates at a stretch. This means that a driving force is input to the pinion carrier 42 from the side opposite to the main motor 31. At this time, since the input rotation of the sun gear 39 does not change, the stopper 41a of the ring gear 41 rotates clockwise within the play 44a by α and absorbs the input rotation from the pinion carrier 42. That is, it corresponds to step 4 in FIG. 6A, corresponds to a state in which the position of the stopper 41a shifts from (B) to (C) in FIG. 6 (B), and in FIG. Corresponds to the state of transition from the convex vertex 71b to the concave bottom point 71a, that is, the transition from (b) to (c), and corresponds to the state of the collinear chart (c) in FIG. 6 (d). .
[0030]
That is, in step 1 to step 4 as described above, even if a rotational force is input from the pinion carrier 42 by the pressing force of the detent spring 72, as shown in the nomograph, the rotational speed is reduced. Since it is input to the ring gear 41, it is possible to further suppress the impact applied to the stopper 41a, and to improve the durability.
[0031]
Further, since the driving force from the detent mechanism is not input to the main motor 31, only the amount of rotation needs to be controlled without considering the step-like movement of the detent mechanism. Stable control can be performed. In the prior art, since the play δ is provided at the end of the control shaft, the play δ can only take a value corresponding to the shaft diameter of the shaft, and very delicate processing is required. However, in the present embodiment, by providing the play 44a on the outer periphery of the ring gear 41, it is possible to make a larger rotation diameter when providing play than in the prior art, and the ring gear outer periphery and the receiving portion can be processed. It can be easily processed.
[0032]
Further, the elastic member 44b can be easily provided because the diameter of rotation when providing play is increased. As a result, when the stopper 41a rotates in the play 44a, the elastic members 44b provided on both sides of the stopper 41a absorb the impact, so that the end of the stopper 41a and the play 44a collide with each other, thereby reducing the durability. Can be avoided.
[0033]
(Other examples)
The shift-by-wire system of the present invention has been described based on the first embodiment, the second embodiment, and the third embodiment. However, the specific configuration is not limited to these embodiments, and claims are made. Modifications and additions of the design are allowed without departing from the scope of the present invention described in the claims. For example, in the first embodiment, a single motor is used, but the present invention may be applied to a shift actuator having two motors.
[Brief description of the drawings]
FIG. 1 is an overall system diagram showing a shift-by-wire system of a first embodiment.
FIG. 2 is a control system diagram of the shift-by-wire system of the first embodiment.
FIG. 3 is a schematic perspective view showing a detent mechanism in the shift-by-wire system of the first embodiment.
FIG. 4 is a cross-sectional view of a shift actuator in the shift-by-wire system of the first embodiment.
FIG. 5 is a cross-sectional view taken along line CC of the shift actuator in the shift-by-wire system according to the first embodiment.
FIG. 6 is a time chart showing the operation of the shift-by-wire system of the first embodiment.
FIG. 7 is a schematic perspective view showing a conventional detent mechanism.
FIG. 8 is an enlarged cross-sectional view showing a coupling portion of a control shaft of a shift actuator in a conventional shift-by-wire system.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Indicator 2 Fail lamp 3 Ignition switch 4 Shift switch 5 Shift lock mechanism 20 Shift control unit 21 Main driver 21a Main CPU
22a Sub CPU
30 shift actuator 31 main motor 31a worm 33 gear mechanism 34 angle sensor 35 temperature sensor 36 control shaft 37 worm wheel 38 input shaft 39 sun gear 40 pinion gear 41 ring gear 42 pinion carrier 42a output boss portion 43 first housing 44 second housing 45 third Housing 46 Oil seal 47a Ball bearing 47b Ball bearing 47c Bearing 48a Bearing 48b Bearing 49 Sensor rod 60 Automatic transmission 61 Transmission mechanism 62 Inhibitor switch 63 CVT control unit 64 Engine control unit 70 Detent mechanism 71 Detent lever 71a Concavity 71b Convex 72 Detent spring 73 Roller 74 Shift valve 80 -King mechanism 100 motor 101 worm 102 worm wheel 103 boss portion 103a inner wall surface 104 coupling portion 110 actuator position sensor 120 valve position sensor 130 control mechanism 131 control shaft 131a end portion 131b engagement surface 132 detent lever 133 detent spring 134 roller 135 recess 136 Convex A Planetary chamber B Warm chamber

Claims (2)

A shift switch that is operated by a driver and outputs a switch signal indicating a shift position corresponding to each range such as a parking range and a drive range;
A detent mechanism provided in the automatic transmission and connected to the manual valve to position the parking rod at a predetermined position;
A shift actuator for driving the detent;
Shift control means for inputting a switch signal of the shift switch and outputting a command to the shift actuator as a shift position indicated by the switch signal;
In a shift-by-wire system with
The shift actuator is connected to a sun gear of a planetary gear mechanism having a sun gear, a pinion carrier, and a ring gear, and includes an actuator output shaft connected to the pinion carrier,
A play that allows the ring gear to rotate relative to the receiving part is provided between the receiving part for receiving the ring gear and the outer periphery of the ring gear. Shift-by-wire system characterized by being set to. The shift-by-wire system according to claim 1,
A shift-by-wire system, characterized in that an elastic member is provided between the circumferentially opposite sides of the convex portion provided on the outer periphery of the ring gear and the idle circumferential end.

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