ROTATION RESTRICTION CONTROL DEVICE, ROTATION RESTRICTION DEVICE AND VEHICLE

Abstract

A rotation restriction control device for a vehicle, including a restriction mechanism in which a rotation restriction state is selectable from at least two states, including a first state in which rotation is restricted only in a forward direction in a transmission, and a second state in which rotation is restricted only in a reverse direction in the transmission, the rotation restriction control device comprising: a selection section that selects the turning restriction state based on a road surface on which the vehicle is traveling and where the vehicle enters a parking state; and a control section that controls the rotation restriction state of the restriction mechanism depending on a selection result of the selection section when the vehicle enters the parking state.

Description

Technical FieldThe present disclosure relates to a rotation restriction control device, a rotation restriction device, and a vehicle.Prior ArtConventionally, a vehicle equipped with a parking mechanism that restricts rotation of a transmission during parking is known (see, e.g., JP 2001-289317 A). Such a parking mechanism includes a parking gear or the like, and brings the vehicle into a parking state based on the operation of an operation lever by a driver, the operation of an actuator in the mechanism, or the like.JP 2017-67 138 A relates to a parking state determination part for determining whether or not a shift lever is selected in a parking range. A vehicle inclination determination part determines whether or not an attitude of a vehicle is maintained in an inclined state. A parking release control part transmits a second torque in a direction opposite to that of a first torque transmitted from a drive system to an output shaft from a motor to the output shaft through a clutch device when a driver operates a shift operation of the shift lever from the parking range to another range.SUMMARY OF THE INVENTIONTechnical ProblemHowever, when the vehicle is in the parking state on an inclined road surface such as a slope, a large load is applied to the parking mechanism due to the weight or the like of the vehicle stopping on the inclined road surface. Therefore, there is a possibility that the load deteriorates the manipulability at the time of canceling the parking state.An object of the present disclosure is to provide a rotation restriction control device, a rotation restriction device, and a vehicle capable of improving the manipulability at the time of parking release.Solution of the ProblemA rotation restriction control device according to the present disclosure is a rotation restriction control device for a vehicle including a restriction mechanism in which a rotation restriction state is selectable from at least two states including a first state in which rotation is restricted only in a forward direction in a transmission and a second state in which rotation is restricted only in a rearward direction in the transmission, the rotation restriction control device including: a selection portion that selects the rotation restriction state based on a road surface on which the vehicle travels and where the vehicle enters a parking state; and a control portion that controls the rotation restriction state of the restriction mechanism depending on a selection result of the selection portion when the vehicle enters the parking state.A rotation restricting device according to the present disclosure includes:a restriction mechanism disposed on a power transmission side of a transmission mounted in a vehicle, wherein the restriction mechanism in which a rotation restricted state is selectable from at least two states including a first state in which rotation is restricted only in a forward direction in the transmission and a second state in which rotation is restricted only in a reverse direction in the transmission; andthe rotation restriction control device described above.A vehicle according to the present disclosure is a vehicle including:a transmission; andthe rotation limiting device described above.Advantageous Effects of the InventionAccording to the present disclosure, it is possible to improve the operation at the time of parking release.Brief Description of the DrawingsFIG. 1 is a diagram showing a configuration of a vehicle having a rotation restriction control device according to an embodiment of the present disclosure; FIG. 2A is a diagram showing a vehicle in a parking state on a downwardly inclined surface; FIG. 2B is a diagram illustrating the vehicle in the parking state on an upward inclined surface; FIG. 2C is a diagram illustrating the vehicle in the parking state on a planar surface; FIG. 3 is a flowchart illustrating an exemplary process performed when rotation restriction control is executed in the rotation restriction control device; and FIG. 4 is a flowchart illustrating an exemplary process performed when control for canceling the rotation restriction is performed in the rotation restriction control device.DESCRIPTION OF EMBODIMENTSHereinafter, the present embodiment will be described in detail with reference to the accompanying drawings. FIG. 1 is a diagram showing a configuration of the vehicle 1 including a rotation restriction control device 100 according to an embodiment of the present disclosure.As illustrated in FIG. 1, the vehicle 1 includes a drive shaft 2, a differential gear 3, drive wheels 4, an engine 5, a transmission 6, an inclination sensor 7, a parking signal output block 8, a restriction mechanism 10, and a rotation restriction control device 100.The engine 5 is, for example, an internal combustion engine such as a diesel engine. The power of the engine 5 is transmitted to the transmission 6 via a clutch (not shown), and the power transmitted to the transmission 6 is transmitted to the drive wheels 4 via the input shaft 2 and the differential gear 3.The transmission 6 is, for example, a manual transmission or an automatic transmission (for example, an automated manual transmission (AMT)), and includes a plurality of speed stages. In other words, the transmission 6 includes a transmission mechanism or the like that connects or disconnects an output shaft of the engine 5 to or from the input shaft 2 and changes the gear ratio.The inclination sensor 7 is a known sensor that detects information on the inclination of a road surface on which the vehicle 1 is moving.For example, when the position of the operation lever in the vehicle 1 is in a parking range, the parking signal output section 8 outputs, to the rotation restriction control device 100, a parking signal indicating that the vehicle 1 is in the parking state. Note that the parking signal may be output by the parking signal output section 8 based on a position other than the position of the operation lever.The restriction mechanism 10 is a mechanism for restricting the rotation of the transmission 6.The first one-way clutch 11 and the second one-way clutch 12 are switchable one-way clutches configured such that a restricted state in which the rotation of the vehicle 1 in the forward direction or in the reverse direction is restricted and a released state in which the restricted state is canceled are selectable in the transmission 6.The first one-way clutch 11 is configured to be capable of limiting the rotation of the transmission 6 in the forward direction of the vehicle 1. The second one-way clutch 12 is configured to be capable of restricting the rotation of the transmission 6 in the rearward direction of the vehicle 1.Note that a known configuration may be used for the configuration of the first one-way clutch 11 and the second one-way clutch 12, i.e., for the configuration of the switchable one-way clutches. It should also be noted that the first one-way clutch 11 and the second one-way clutch 12 are fixed at appropriate positions, for example, on the transmission 6.Further, in FIG. 1, the first one-way clutch 11 and the second one-way clutch 12 are arranged in this order with respect to the transmission 6, but the arrangement of the first one-way clutch 11 and the second one-way clutch 12 may be reversed. Further, the first one-way clutch 11 and the second one-way clutch 12 may be arranged side by side or apart from each other.The restriction mechanism 10 includes a first one-way clutch 11 and a second one-way clutch 12, and is therefore configured such that a rotation restriction state is selectable from a first state, a second state, and a third state.The first state is a state in which the rotation of the transmission 6 is restricted only in the forward direction, and is also a state in which the first one-way clutch 11 is in the restricted state and the second one-way clutch 12 is in the released state.The second state is a state in which the rotation of the transmission 6 is restricted only in the reverse direction, and is also a state in which the first one-way clutch 11 is in the released state and the second one-way clutch 12 is in the restricted state.The third state is a state in which the rotation of the transmission 6 is restricted in both the forward direction and the reverse direction, and is also a state in which both the first one-way clutch 11 and the second one-way clutch 12 are in the restricted state.Moreover, during the travel of the vehicle 1 or the like, the restriction mechanism 10 is placed in a restriction release state in which the rotation restriction state is released. The restriction release state is a state in which both the first one-way clutch 11 and the second one-way clutch 12 are in the released state.The rotation restriction control device 100 includes a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM), and input / output circuits, which are not illustrated in the figures. The rotation restriction control device 100 controls the state of rotation restriction of the restriction mechanism 10 based on a preset program. The rotation restriction control device 100 includes a judgment section 110, a selection section 120, and a control section 130.The judgment section 110 obtains a detection result of the inclination sensor 7 and judges the road surface on which the vehicle 1 is traveling. For example, when the detection result of the inclination sensor 7 is an inclination, the judging section 110 judges that the road surface is an upward inclined surface. When the detection result of the inclination sensor 7 is a downward inclination, the judging section 110 determines that the road surface is a downward surface. The judging section 110 determines that the road surface is a planar surface when the detection result of the inclination sensor 7 is neither an upward inclination nor a downward inclination, i.e., when the detection result is a planar surface.The selection section 120 selects the rotation restriction state of the restriction mechanism 10 on the basis of the road surface on which the vehicle 1 travels and which is the judgment result of the road surface by the judgment section 110.Specifically, when the road surface is a downward inclined surface, the selection portion 120 selects the above-described first state in which the rotation of the transmission 6 is restricted only in the forward direction.When the road surface is an upward inclined surface, the selection portion 120 selects the above-described second state in which the rotation of the transmission 6 in the reverse direction is restricted.When the road surface is a flat surface, the selection section 120 selects the third state in which the rotation of the transmission 6 in the forward direction and the reverse direction is restricted.When the vehicle 1 enters the parking state, the control section 130 controls the rotation restricting state of the restricting mechanism 10 in accordance with the selection result of the selection section 120.Specifically, the control section 130 recognizes whether or not the vehicle 1 is in the parking state based on the presence or absence of the parking signal output from the parking signal output section 8. The control section 130 recognizes that the vehicle 1 is in the parking state when the parking signal is continuously obtained, and recognizes that the vehicle 1 is not in the parking state when the parking signal is not output.Upon start of the reception of the parking signal, the control section 130 recognizes that the vehicle 1 enters the parking state, and when the selection section 120 selects the first state (when the road surface is a downward inclined surface), the control section 130 sets the rotation restricting state to the first state, i.e., the state in which the rotation of the transmission 6 is restricted only in the forward direction (see FIG. 2A ).Upon start of the reception of the parking signal, the control section 130 recognizes that the vehicle 1 enters the parking state, and when the selection section 120 selects the second state (when the road surface is an upward inclined surface), the control section 130 sets the rotation restricting state to the second state, i.e., the state in which the rotation of the transmission 6 is restricted only in the reverse direction (see FIG. 2B ).Upon starting to acquire the parking signal, the control section 130 recognizes that the vehicle 1 enters the parking state when the parking signal is acquired, and when the selection section 120 selects the third state (when the road surface is a flat surface), the control section 130 sets the rotation restricting state to the third state, i.e., the state in which the rotation of the transmission 6 in the forward direction and the reverse direction is restricted (see FIG. 2C ).With this configuration, in the present embodiment, the rotation restriction state of the transmission 6 can be changed depending on the inclination of the road surface. For example, when the vehicle 1 is in the parking state on the downward inclined surface, the rotation in the rearward direction in which the vehicle 1 does not move by its own weight is not restricted, while the rotation is restricted only in the forward direction in which the vehicle 1 moves by its own weight.Further, when the vehicle 1 is in the parking state on the inclined surface upward, the rotation in the forward direction in which the vehicle 1 does not move by its own weight is not restricted, while the rotation is restricted only in the rearward direction in which the vehicle 1 moves by its own weight.That is, in the present embodiment, depending on the inclination of the road surface on which the vehicle 1 enters the parking state, the rotation of the transmission 6 is restricted only in the direction in which restriction of the rotation is required. In this way, it is possible to reduce the load of a rotation restriction device including the restriction mechanism 10 and the rotation restriction control device 100.In addition, when recognizing that the vehicle 1 is not in the parking state, the control portion 130 sets the above-described restriction release state in which the rotation restriction state of the restriction mechanism 10 is released. Thereby, the vehicle 1 can travel in both forward and rearward directions.Next, an operation example performed when the rotation restriction control is executed in the rotation restriction control device 100 will be described. FIG. 3 is a flowchart illustrating an exemplary process performed when the rotation restriction control is executed in the rotation restriction control device 100. The processing in FIG. 3 is suitably executed when the vehicle 1 starts traveling, i.e., when the restriction mechanism 10 is placed in the restriction release state.As illustrated in FIG. 3, the rotation restriction control device 100 judges whether the parking state of the vehicle 1 has been recognized (step S 101).When the judgment result indicates that the parking state of the vehicle 1 has not been recognized (step S 101: NO), the process of step S 101 is repeated. On the other hand, when the parking state of the vehicle 1 has been recognized (step S 101: YES), the rotation restriction control device 100 judges the road surface (step S 102), and judges whether or not the judged road surface is a downward inclined surface (step S 103).When the judgment result indicates that the road surface is a downward inclined surface (step S 103: YES), the rotation restriction control device 100 selects the first state as the rotation restriction state to set the restriction mechanism 10 to the first state (step S 104).On the other hand, when the road surface is not a downward inclined surface (step S 103: NO), the rotation restriction control device 100 judges whether or not the road surface last judged in step S 101 is an upward inclined surface (step S 105).When the judgment result indicates that the road surface is an upward inclined surface (step S 105: YES), the rotation restriction control device 100 selects the second condition as the rotation restriction state to put the restriction mechanism 10 in the second state (step S 106).On the other hand, when the road surface is not an upward inclined surface, that is, when the road surface is a flat surface (step S 105: NO), the rotation restriction control device 100 selects the third state as the rotation restriction state to set the restriction mechanism 10 in the third state (step S 107). After step S 104, step S 106, or step S 107, the present control ends.Next, an operation example executed when control for canceling the rotation restriction is executed in the rotation restriction control device 100 will be described. FIG. 4 is a flowchart illustrating an exemplary process performed when the control for releasing the rotation restriction control device 100 is executed. The processing in FIG. 4 is suitably executed after the processing illustrated in FIG. 3 is executed, i.e., when the restriction mechanism 10 is in one of the three states (first state, second state, third state).As illustrated in FIG. 4, the rotation restriction control device 100 judges whether or not a travel start state of the vehicle 1 is detected (step S 201). The rotation restriction control device 100 recognizes the travel start state of the vehicle 1, for example, when the position of the manipulation lever is in a travel range. When the judgment result indicates that the travel start state of vehicle 1 is not recognized (step S 201: NO), the process of step S 201 is repeated. On the other hand, when the travel start state of the vehicle 1 is recognized (step S 201: YES), the rotation restriction control device 100 judges whether or not the vehicle 1 has started travel (step S 202). When the judgment result indicates that the vehicle 1 has not started running (step S 202: NO), the process of step S 202 is repeated.On the other hand, when the vehicle 1 has started traveling (step S 202: YES), the rotation restriction control device 100 sets the restriction release state in which the restriction by the restriction mechanism 10 is released (step S 203). After step S203, control is terminated.According to the present embodiment configured as described above, depending on the inclination of the road surface on which the vehicle 1 enters the parking state, the rotation of the transmission 6 is restricted only in the direction in which the restriction of the rotation is required. In this way, it is possible to reduce the load of the rotation restricting device including the restricting mechanism 10 and the rotation restricting control device 100.Typically, a parking gear or the like is disposed in a restricting mechanism that restricts the rotation of a transmission during parking of a vehicle, and the parking mechanism restricts the rotation of the transmission itself.However, when the vehicle comes to a stop on the inclined road surface, a large load is applied to the parking mechanism to prevent the vehicle from rolling down due to its own weight. Therefore, in the operation or release of the transmission performed when the vehicle starts from the inclined road surface, a force exceeding the load applied to the parking mechanism is required. Accordingly, in the general parking mechanism, there is a possibility that the manipulability is impaired at the time of parking release.In contrast, in the present embodiment, the rotation of the transmission 6 is restricted only in a direction in which restriction of the rotation is required. It is therefore possible to start the travel of the vehicle without cancelling the restriction by the restriction mechanism 10. That is, the restraining mechanism 10 only needs to be released when the load is removed after the vehicle starts. Accordingly, the present embodiment makes it possible to improve the operation at the time of parking release.In order to prevent a vehicle from descending on an inclined road, for example, on a slope, due to its own weight, the parking mechanism is relatively large, so that the vehicle 1 is able to stop on the inclined road. Therefore, in order to arrange the parking mechanism as described above, a space for arranging the parking mechanism around the transmission is required.In contrast, in the present embodiment, the restriction mechanism 10 having two one-way clutches 11 and 12 is disposed on an output shaft of the transmission 6. Thereby, it is possible to reduce the overall size of the parking mechanism. Consequently, it is possible to eliminate the need to provide a space for disposing the restriction mechanism 10 in the vicinity of the transmission 6. Moreover, it is possible to reduce the number of parts because it is not necessary to provide such a parking mechanism as described above.When the vehicle 1 is in the parking state on a flat surface, the rotation of the transmission 6 in both the forward and reverse directions is restricted. In this way, it can be ensured that the vehicle 1 stops in the parking state. In addition, the vehicle 1 is not loaded on a flat surface by its own weight. Thus, even if the rotation of the transmission 6 in both forward and reverse directions is restricted, there is no problem in operability at the time of parking release.Note that in the above-described embodiment, when the vehicle 1 enters the flat surface parking state, the rotation of the transmission 6 in both the forward and reverse directions is restricted. However, the present disclosure is not limited thereto. For example, in a case where the vehicle 1 enters the parking state on a planar surface, the restriction mechanism 10 may restrict the rotation of the transmission 6 by a mechanism other than the restriction mechanism 10.Examples of the mechanism other than the restriction mechanism 10 include, for example, the general parking mechanism described above.The vehicle 1 does not descend on the flat surface by its own weight unlike the inclined road. Therefore, no load is applied as on the inclined road surface in the parking state. Accordingly, the parking mechanism can be kept relatively small even when the above-described parking mechanism is arranged. Thus, the degree of influence on an arrangement space around the transmission 6 is small.In the above embodiment, the restricting mechanism 10 is disposed on the input shaft 2 (output shaft of the transmission 6), but the present disclosure is not limited thereto. For example, the restriction mechanism may also be disposed on the upstream side of the differential gear 3.Further, in the above embodiment, the one-way clutch mechanism having two selectable one-way clutches is described as an example of the restricting mechanism 10, but the present disclosure is not limited thereto. For example, as the restraining mechanism, a one-way clutch mechanism including a single one-way clutch and making it possible to achieve three rotation restraining states in the forward direction, in the reverse direction, and in both the forward direction and the reverse direction with the one-way clutch may be used.Further, in the above embodiment, the rotation restriction control device 100 includes a judgment section 110, a selection section 120, and a control section 130, but the present disclosure is not limited thereto. The judging section, the selecting section and the controlling section may be separately arranged.In the above-described embodiment, the judging section 110 judges the road surface, but the present disclosure is not limited thereto. The information on the road surface may be obtained from a device other than the rotation restriction control device.Moreover, the aforementioned embodiments merely describe examples of implementing the present disclosure, and should not be construed as limiting the technical scope of the present disclosure. In other words, the present disclosure may be implemented in various forms without departing from the scope or essential features of the disclosure.This application is based on Japanese Patent Application No. 2020-098570, filed on Jun. 5, 2020, the disclosure of which is incorporated herein by reference in its entirety.Industrial applicabilityThe rotation restriction control device of the present disclosure is useful as a rotation restriction control device, a rotation restriction device, and a vehicle capable of improving operability at the time of parking release.Reference numerals denote reference numerals1 Vehicle 2 Drive shaft 3 Differential gear 4 Drive wheels 5 Motor 6 Transmission 7 Inclination sensor 8 Parking signal output block 10 Restriction mechanism 11 First one-way clutch 12 Second one-way clutch 100 Rotation restriction control device 110 Judgment section 120 Selection section 130 Control section

Claims

A rotation restriction control device for a vehicle including a restriction mechanism in which a rotation restriction state is selectable from at least two states including a first state in which rotation is restricted only in a forward direction in a transmission and a second state in which rotation is restricted only in a rearward direction in the transmission, the rotation restriction control device comprising: a selection portion that selects the rotation restriction state based on a road surface on which the vehicle travels and where the vehicle enters a parking state; and a control portion that controls the rotation restriction state of the restriction mechanism depending on a selection result of the selection portion when the vehicle enters the parking state.The rotation restriction control device according to claim 1, wherein the selection portion is configured to: select the first state when the road surface is a downward inclined surface, and select the second state when the road surface is an upward inclined surface.The rotation restriction control device according to claim 2, wherein: in the restriction mechanism, the rotation restriction state is selectable from the first state, the second state, and a third state in which the rotation in both the forward direction and the rearward direction is restricted in the transmission, and the selection portion selects the third state when the road surface is a flat surface.A rotation restricting device comprising: a restricting mechanism which is disposed on a power transmission side of a transmission mounted in a vehicle and in which a rotation restricting state is selectable from at least two states including a first state in which rotation is restricted only in a forward direction in the transmission and a second state in which rotation is restricted only in a rearward direction in the transmission; and a rotation restricting control device according to claim 1.The rotation restricting device according to claim 4, wherein the restricting mechanism comprises a one-way clutch mechanism in which the rotation restricting state is selectable from the at least two states including the first state and the second state.The rotation restricting device according to claim 4, wherein the restricting mechanism is disposed on a drive shaft to which power from the transmission is transmitted.A vehicle comprising: a transmission; and a rotation restricting device according to claim 4.

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