JP6634817B2 - Switching control device - Google Patents

Description

  The present invention relates to a switching control device, and more particularly to a switching control device that controls switching between a two-wheel drive state and a four-wheel drive state in a four-wheel drive vehicle.

  2. Description of the Related Art Conventionally, a switching control device that adds an actuator that causes a shift fork to move by driving a motor to a transfer device of a four-wheel drive vehicle and switches between a two-wheel drive state and a four-wheel drive state by operating a switch from the room is known. ing. In these devices, a shift fork causes a spool having an inner spline to stroke, and a spline at an end of a propeller shaft and a spline that is gear-engaged with an output shaft of a transmission are fitted and disengaged to transmit driving force.・ Switch off.

  In these switching control devices, the two-wheel drive state and the four-wheel drive state can be switched from inside the vehicle, but since the splines are fitted and disengaged by the motor, there is actually no abnormality in the actuator and the spline It could not be confirmed whether the fitting and disengagement were performed reliably.

  Therefore, it is possible to confirm the operation of the actuator by providing a plurality of position switches on the housing of the actuator and the worm wheel as the reduction mechanism, and detecting the rotation angle of the worm wheel by a combination of energization and non-energization of the position switch. Is being done. However, if one of the plurality of position switches is broken, the drive state is erroneously detected, and if the ECU continues to issue a drive command to the motor based on the erroneous detection, the motor may be damaged. was there. In addition, there is a possibility that the vehicle may be in a driving state different from the driver's intention, or that the vehicle may not be able to travel due to a combination with a driving state of the differential control device on the drive train.

  In order to solve such a problem, the applicant of the present application detects that an abnormality has occurred in the position switch and stops the operation of the actuator when the position switch for detecting the driving state fails, A driving force switching control device that can avoid running impairment has already been proposed (see Patent Document 1).

JP 2005-225385 A

  The present invention is a further improvement on the invention described in Patent Document 1.

  SUMMARY OF THE INVENTION It is an object of the present invention to provide a switching control device that can not only make a vehicle incapable of traveling but also avoid a state in which traveling is difficult even when an abnormality occurs in a sensor that detects a vehicle state.

The switching control device according to the present invention includes:
A switching member for switching the vehicle state according to the position,
A plurality of sensors for detecting the position of the switching member;
An actuator for driving the switching member,
A storage unit that stores a table that associates a combination pattern of on / off states of the plurality of sensors in a normal state with respect to each vehicle state, and reads out the table stored in the storage unit and the plurality of sensors; A control unit that controls the operation of the actuator, based on the combined ON / OFF combination pattern, so that the switching member is positioned at a position corresponding to a desired vehicle state.
With
If it is determined that an abnormality has occurred in any of the plurality of sensors, the control unit uses the combination pattern of on and off read from the plurality of sensors, the sensor in which the abnormality has occurred In accordance with the combination of the specified sensor and the desired vehicle state, the switching member is positioned at a position corresponding to the desired vehicle state by using a table stored in the storage unit. Next, the operation of the actuator is controlled.

  According to the switching control device of the present invention, even when an abnormality occurs in a sensor that detects a vehicle state, the sensor in which the abnormality has occurred is specified by the control unit, and the sensor is determined according to a combination of the specified sensor and a desired vehicle state. Thus, by controlling the operation of the actuator, the switching member can be positioned at a position corresponding to a desired vehicle state. Thereby, even if an abnormality occurs in the sensor, it is possible to switch to the desired vehicle state, so that not only the running becomes impossible, but also a state in which it is difficult to run can be avoided.

  In the switching control device according to the present invention, the control unit stores an on / off combination pattern read from the plurality of sensors at the time of ignition off in the storage unit, and is read from the plurality of sensors at the time of ignition on. The sensor in which the abnormality has occurred may be specified by comparing the combined on / off pattern with the combined on / off pattern at the time of ignition off stored in the storage unit.

  According to such an embodiment, it is possible to detect that an abnormality has occurred in the sensor before switching the vehicle state, and to specify the sensor in which the abnormality has occurred.

  In the switching control device according to the present invention, the control unit changes the on / off combination pattern read from the plurality of sensors by moving the switching member, and stores the moving direction of the switching member and the storage unit in the storage unit. A combination pattern of on / off in a normal state of the plurality of sensors based on the obtained table, and a combination of the estimated combination pattern of on / off and on / off read from the plurality of sensors. The sensor in which the abnormality has occurred may be specified by comparing the sensor with the pattern.

  According to such an embodiment, it is possible to detect that an abnormality has occurred in the sensor and to specify the sensor in which the abnormality has occurred.

  In the switching control device according to the present invention, the storage unit stores a switching time required for switching each vehicle state, and the control unit takes the switching member over a switching time stored in the storage unit or more. While moving, the on / off combination pattern in the normal state of the plurality of sensors is estimated based on the table stored in the storage unit, and the estimated on / off combination pattern is read from the plurality of sensors. The sensor in which the abnormality has occurred may be specified by comparing the output on / off combination pattern.

  According to such an embodiment, it is possible to detect that an abnormality has occurred in the sensor and to specify the sensor in which the abnormality has occurred.

  In the switching control device according to the present invention, the control unit may store the specified sensor in the storage unit.

  According to such an embodiment, even after the ignition is once turned off, the abnormality processing can be continuously performed.

  In the switching control device according to the present invention, the control unit specifies the sensor in which the abnormality has occurred, and then, among the sensors other than the sensor in which the abnormality has occurred, the switching member corresponds to a desired vehicle state from the movement start side. Whether or not there is a sensor that switches on and off when reaching the position is determined based on the table stored in the storage unit, and when it is determined that the sensor is present, the switching member is moved to a desired position. By moving toward a position corresponding to the vehicle state and detecting on / off switching read from the sensor, it is determined that the switching member has been positioned at a position corresponding to a desired vehicle state. You may.

  According to this aspect, even when an abnormality occurs in the sensor that detects the vehicle state, the switching member is moved to a position corresponding to the desired vehicle state according to the combination of the specified sensor and the desired vehicle state. Can be positioned.

  In the switching control device according to the present invention, after the control unit identifies the sensor in which the abnormality has occurred, the control unit may select a desired vehicle from among the sensors other than the sensor in which the abnormality has occurred, from the side opposite to the movement start side. It is determined based on a table stored in the storage unit whether or not there is a sensor that switches on and off when reaching a position corresponding to the state. The member is moved toward a position corresponding to a desired vehicle state, and after detecting on / off switching read from the sensor, the switching member is moved in the opposite direction and read from the sensor. By detecting on / off re-switching, it may be determined that the switching member has been positioned at a position corresponding to a desired vehicle state.

  According to this aspect, when an abnormality occurs in the sensor that detects the vehicle state, the switching member is positioned at a position corresponding to the desired vehicle state according to the combination of the specified sensor and the desired vehicle state. can do.

  In the switching control device according to the present invention, the storage unit stores a switching time required for switching each vehicle state, and the control unit specifies a sensor in which an abnormality has occurred, and then detects a sensor other than the sensor in which the abnormality has occurred. It is determined whether there is a sensor that switches on and off when the switching member reaches a position corresponding to a desired vehicle state, based on a table stored in the storage unit, and the sensor determines If it is determined that there is not, by moving the switching member based on the switching time stored in the storage unit, it is determined that the switching member is positioned at a position corresponding to a desired vehicle state Is also good.

  According to this aspect, when an abnormality occurs in the sensor that detects the vehicle state, the switching member is positioned at a position corresponding to the desired vehicle state according to the combination of the specified sensor and the desired vehicle state. can do.

  ADVANTAGE OF THE INVENTION According to this invention, even if abnormality arises in the sensor which detects a vehicle state, not only cannot it become impossible to drive | run, but it can avoid the state which is difficult to drive.

FIG. 1 is a schematic configuration diagram of a vehicle including a switching control device according to an embodiment of the present invention. FIG. 2 is a schematic configuration diagram of a switching control device according to an embodiment of the present invention. FIG. 3 is an enlarged sectional view showing a transfer device of the switching control device shown in FIG. FIG. 4 is an enlarged sectional view showing an actuator of the transfer device shown in FIG. FIG. 5 is a schematic diagram for explaining the arrangement of sensors in the transfer device shown in FIG. FIG. 6 is a flowchart for explaining the operation of the control unit of the switching control device shown in FIG. FIG. 7 illustrates an example of a table that associates a combination pattern of ON and OFF when the sensor is normal with respect to each vehicle state. FIG. 8 is a table showing an ON / OFF combination pattern read from the sensor in each vehicle state when an abnormality occurs in SW2. FIG. 9 shows another example of a table that associates a combination pattern of ON and OFF when the sensor is normal for each vehicle state. FIG. 10 is a table showing an ON / OFF combination pattern read from the sensor in each vehicle state when an abnormality occurs in SW2.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The embodiment described below shows an example in which the present invention is implemented, and the present invention is not limited to the specific configuration described below. In carrying out the present invention, a specific configuration according to the embodiment may be appropriately adopted.

  FIG. 1 is a schematic configuration diagram of a vehicle including a switching control device according to the present embodiment. FIG. 2 is a schematic configuration diagram of a switching control device according to the present embodiment.

  In the example shown in FIGS. 1 and 2, the vehicle 1 is a four-wheel drive vehicle, and includes an engine 2, a transmission 3, a front wheel 6F and a rear wheel 6R, a front differential 5F and a rear differential 5R, and a vehicle. A switching control device 4 for controlling switching of the state.

  The switching control device 4 includes the transfer device 10 and a control unit 41 that controls the operation of the transfer device 10.

  As shown in FIG. 1, the transfer device 10 has an input shaft 24, a first output shaft 11, and a second output shaft 12. The input shaft 24 is connected to the transmission 3 connected to the engine 2, and the rotational driving force of the engine 2 is input to the input shaft 24 via the transmission 3. The first output shaft 11 is connected to the rear differential 5R, and outputs a rotational driving force to the left and right rear wheels 6R via the rear differential 5R. The second output shaft 12 is connected to the front differential 5F, and outputs a rotational driving force to the left and right front wheels 6F via the front differential 5F.

  FIG. 3 is an enlarged cross-sectional view illustrating the transfer device 10. FIG. 4 is an enlarged sectional view showing the actuator 30 of the transfer device 10. FIG. 5 is a schematic diagram for explaining the arrangement of the sensors SW1, SW2, and P-SW in the transfer device 10.

  As described above, the transfer device 10 is disposed between the transmission 3, the rear differential 5R, and the front differential 5F, and operates the actuator 30 to change the driving state of the vehicle to two-wheel drive or four-wheel drive. (Center differential lock) and four-wheel drive (center differential free).

  Further, the transfer device 10 of the present embodiment has a configuration in which the final reduction ratio at the time of four-wheel drive can be switched between high gear and low gear by the speed reducer 23 in addition to these three vehicle states. For example, by operating a switch 43 (see FIG. 2) from inside the vehicle, a high and low shift actuator (not shown) operates the high and low shift lever 20 to switch between a high gear and a low gear.

  As shown in FIG. 3, the rotational driving force from the transmission 3 is transmitted to the first output shaft 11 via the input shaft 24. The rotational driving force of the first output shaft 11 can be transmitted from the center differential unit 13 to the second output shaft 12 via the silent chain 19. The center differential unit 13 is a device that absorbs a difference in rotation speed between the first output shaft 11 and the second output shaft 12, and is configured by a planetary gear mechanism.

  As shown in FIG. 3, the transfer device 10 includes a first shaft (switching member) 14 fitted to an output gear 31 (see FIGS. 4 and 5) of the actuator 30 by a rack and pinion mechanism, and a first shaft 14. A second shaft 15 disposed in parallel with a two-wheel / four-wheel switching shift fork 16 and a center disposed movably in an axial direction within a predetermined range with respect to the first shaft 14 and the second shaft 15; It has a differential lock shift fork 17 and sleeves 16A, 17A fixed to the ends of the shift forks 16, 17, respectively. The first shaft 14 and the second shaft 15 are provided with a plurality of large-diameter portions 14A, 15A in order to define the axially movable range of the shift forks 16, 17 with respect to the shafts 14, 15, respectively. . When the first shaft (switching member) 14 moves in the axial direction and the shift forks 16 and 17 are hooked on the large diameter portions 14A and 15A, the respective axial positions of the shift forks 16 and 17 are defined.

  The switching of the driving state (vehicle state) by the transfer device 10 will be described.

  In the transfer device 10 of the present embodiment, the first shaft (switching member) 14 is moved in the axial direction in accordance with the rotation of the output gear 31, so that the two wheels-4 provided on the shafts 14 and 15 are arranged. The wheel switching shift fork 16 and the center differential lock shift fork 17 move in the axial direction, and the sleeves 16A, 17A provided at the ends of the shift forks 16, 17 move in the axial direction. As a result, the driving state of the vehicle is switched to three states of two-wheel drive, four-wheel drive (center differential lock), and four-wheel drive (center differential free).

  More specifically, in the four-wheel drive (center differential free) state, the member on the second output shaft 12 side and the center differential unit 13 are connected, and the first output shaft 11 and the second output shaft 11 are driven by the planetary gear action of the planetary gear mechanism. The rotational driving force of the first output shaft 11 is transmitted to the second output shaft 12 via the silent chain 19 while the difference in the number of rotations from the output shaft 12 is absorbed. In the four-wheel drive (center differential lock) state, the sleeve 17A is at the upper position in the drawing, the planetary gear mechanism of the center differential unit 13 is locked, and the first output shaft 11 and the second output shaft 12 are directly connected. Thus, the first output shaft 11 and the second output shaft 12 are driven to rotate at the same rotation speed. In the two-wheel drive state, the member on the second output shaft 12 side and the center differential unit 13 are not connected, and the rotational driving force of the input shaft 24 is transmitted only to the first output shaft 11.

  Next, the actuator 30 will be described. As shown in FIGS. 4 and 5, the actuator 30 includes a motor 39, a reduction mechanism including a worm wheel 38 and a worm gear 36, and a waiting mechanism including a spiral spring disposed between the worm wheel 38 and the output gear 31. 37. The worm gear 36 is coaxially fixed to the output shaft of the motor 39. The rotational driving force output from the motor 39 is transmitted from the worm gear 36 to the worm wheel 38, transmitted from the worm wheel 38 to the output gear 31 via the waiting mechanism 37, and The shaft 14 is moved in the axial direction.

  The switching control device 4 of the present embodiment has a plurality (three in the illustrated example) of sensors SW1, SW2, and P-SW that detect the position of the first shaft (switching member) 14.

  In the illustrated example, a circular band electrode TSW is disposed in a well-known manner in a worm wheel accommodating portion of the housing of the actuator 30, and a limit formed by a leaf spring is provided on a side surface of the worm wheel 38. A switch LSW is provided. The limit switch LSW is provided with a first sensor SW1 and a second sensor SW2 which are composed of two terminals. The rotation pattern of the worm wheel 38 is detected by changing the on / off combination pattern of the sensors SW1 and SW2 in accordance with the rotation angle of the worm wheel 38, thereby detecting the axial position of the first shaft 14. Is detected.

  Further, a third sensor P-SW composed of a position switch is provided outside the housing of the actuator 30 so as to contact the side surface of the first shaft 14. The position of the first shaft 14 in the axial direction is detected by switching on / off of the third sensor P-SW in accordance with the amount of movement of the first shaft 14 in the axial direction.

  Therefore, in the present embodiment, the positions of the first shaft 14 and the respective positions corresponding to the three driving states (vehicle states) are determined from the combination pattern of ON / OFF of the three sensors SW1, SW2, and P-SW. Is detectable.

  FIG. 7 links the on / off combination pattern of the sensors SW1, SW2, and P-SW in the normal state to each of the vehicle states "A" to "F" (three driving states and their intermediate states). 4 shows an example of a table. As shown in FIG. 7, when the combination pattern of ON / OFF of the sensors SW1, SW2, and P-SW is changed, the axial position of the first shaft 14 that switches the vehicle state is detected, and the first shaft 14 is further switched. The vehicle state corresponding to the position of the vehicle in the axial direction is detected.

  Next, the control unit 41 will be described. The control unit 41 is, for example, an ECU mounted on the vehicle. The control unit 41 stores information such as power supplied from a battery (not shown), vehicle speed, operation of the manual switch 43, ON / OFF of each of the sensors SW1, SW2, P-SW, and current flowing to the motor 39. Input from outside. The control unit 41 calculates a current supplied to the motor 39 so as to be in a driving state according to the input information, and controls the actuator 30 based on the calculated current value.

  The control unit 41 of the present embodiment has a storage unit 42. The storage unit 42 stores, as shown in FIG. 7, a table that associates a combination pattern of ON / OFF when the sensors SW1, SW2, and P-SW are normal with each vehicle state. Further, when the sensors SW1, SW2, and P-SW are normal, the control unit 41 learns the switching time required to switch the respective vehicle states, and stores the learned switching time in the storage unit 42.

  The control unit 41 causes the first shaft 14 to correspond to a desired vehicle state based on the table stored in the storage unit 42 and the ON / OFF combination pattern read from the sensors SW1, SW2, and P-SW. The operation of the actuator 30 is controlled so as to be positioned at the position.

  By the way, as mentioned in the Background Art section, in the conventional driving force switching control device, if one of the plurality of position switches is broken, the driving state is erroneously detected. If the ECU continues to issue a drive command to the motor, the motor may be damaged. In addition, there is a possibility that the vehicle may be in a driving state different from the driver's intention, or that the vehicle may not be able to travel due to a combination with a driving state of the differential control device on the drive train.

  In order to solve such a problem, if the position switch for detecting the driving state fails, the traveling cannot be performed by detecting that an abnormality has occurred in the position switch and stopping the operation of the actuator. A system that can avoid the problem can be considered. However, for example, when it is desired to adopt the four-wheel drive state when traveling on a rough road, in the above-described system, the operation of the actuator may be stopped in the two-wheel drive state. The driver is forced to drive on rough roads.

  As a further improvement of the above system, the control unit 41 of the present embodiment reads out from any of the sensors SW1, SW2, P-SW when any of the sensors SW1, SW2, P-SW has an abnormality. The sensor in which the abnormality has occurred is identified by using the on / off combination pattern thus determined. Then, the control unit 41 uses the table stored in the storage unit 42 according to the combination of the specified sensor and the desired vehicle state (for example, the vehicle state instructed by the manual switch 43), and performs the first The operation of the actuator 30 is controlled so that the shaft 14 is positioned at a position corresponding to a desired vehicle state. Thus, even when an abnormality occurs in the sensors SW1, SW2, and P-SW, the vehicle can be switched to a desired vehicle state, so that not only the traveling becomes impossible but also a traveling difficult state can be avoided.

  The operation of the control unit 41 will be described in more detail. FIG. 6 is a flowchart for explaining the operation of the control unit 41.

  The control unit 41 stores the on / off combination pattern read from the sensors SW1, SW2, and P-SW3 when the ignition is turned off in the storage unit 42 as a first abnormality detection method, and stores the sensors SW1, SW2, and By comparing the on / off combination pattern read from the P-SW3 with the on / off combination pattern at the time of ignition off stored in the storage unit 42, the sensor in which the abnormality has occurred is specified (step S101). ).

  For example, when the ignition is turned off in the vehicle state “C” in FIG. 7, the control unit 41 stores the combination pattern of (SW1, SW2, P-SW) = (ON, ON, OFF) in the storage unit 42. Remember. Next, when the combination pattern of (SW1, SW2, P-SW) = (ON, OFF, OFF) (corresponding to the vehicle state of "C" in FIG. 8) is read when the ignition is turned on, control is performed. The unit 41 compares the on / off combination pattern read from each of the sensors SW1, SW2, and P-SW3 with the on / off combination pattern at the time of ignition off stored in the storage unit 42, It is specified that an abnormality has occurred in the second sensor SW2. Thus, it is possible to not only detect that an abnormality has occurred in the sensors SW1, SW2, and P-SW before switching the vehicle state, but also specify the sensor SW2 in which the abnormality has occurred.

  As a second abnormality detection method, the control unit 41 changes the on / off combination pattern read from the sensors SW1, SW2, and P-SW3 by moving the first shaft 14, and moves the first shaft 14. Based on the direction and the table stored in the storage unit 42, the on / off combination pattern of the sensors SW1, SW2, P-SW3 in the normal state is estimated, and the estimated on / off combination pattern and the sensor SW1, By comparing the on / off combination pattern actually read from the SW2 and the P-SW3, the sensor in which the abnormality has occurred is specified (Step S102).

  For example, when the vehicle state is “B” in FIG. 7, the control unit 41 moves the first shaft 14 in a direction that switches to the vehicle state “C” in FIG. Based on the direction and the table stored in the storage unit 42, the combination pattern of (SW1, SW2, P-SW) = (ON, ON, OFF) (corresponding to the vehicle state of "C" in FIG. 7) is as follows. Is assumed to be read. Then, when the combination pattern of (SW1, SW2, P-SW) = (ON, OFF, OFF) (corresponding to the vehicle state “C” in FIG. 8) is actually read, the control unit 41 performs the estimation. By comparing the combined ON / OFF pattern and the combined ON / OFF pattern actually read from each of the sensors SW1, SW2, P-SW3, it is determined that an abnormality has occurred in the second sensor SW2. Identify. According to such an embodiment, it is not only possible to detect that an abnormality has occurred in the sensors SW1, SW2, and P-SW, but also to specify the sensor SW2 in which the abnormality has occurred.

  Further, as a third abnormality detection method, the control unit 41 moves the first shaft 14 over a time longer than the switching time stored in the storage unit 42, and detects a sensor based on a table stored in the storage unit 42. The on / off combination pattern of SW1, SW2, P-SW3 in the normal state is estimated, and the estimated on / off combination pattern and the on / off actually read from the sensors SW1, SW2, P-SW3. The sensor in which the abnormality has occurred is identified by comparing the combination pattern with the combination pattern (step S103).

  For example, when the vehicle state is “B” in FIG. 7, the control unit 41 moves the first shaft 14 over a switching time for switching to the vehicle state “C” in FIG. Based on the table stored in 42, it is estimated that the combination pattern of (SW1, SW2, P-SW) = (ON, ON, OFF) (corresponding to the vehicle state of "C" in FIG. 7) will be read out next. I do. If the combination pattern that is actually read does not change from (SW1, SW2, P-SW) = (ON, OFF, OFF) even after a lapse of the switching time or more, the control unit 41 By comparing the estimated combination pattern of on / off with the combination pattern of on / off actually read out from each of the sensors SW1, SW2, P-SW3, an abnormality has occurred in the second sensor SW2. To identify. According to such an embodiment, it is not only possible to detect that an abnormality has occurred in the sensors SW1, SW2, and P-SW, but also to specify the sensor SW2 in which the abnormality has occurred.

  Further, the control unit 41 stores the specified sensor (that is, the sensor in which the abnormality has occurred) in the storage unit 42. Thereby, even after the ignition is turned off once, the abnormality processing can be continuously performed.

  The control unit 41 determines whether there is a sensor that switches on and off when the first shaft 14 reaches a position corresponding to a desired vehicle state among sensors other than the sensor in which the abnormality has occurred. Judgment is made based on the table stored in the storage unit 42, and one of the first to third switching processing methods described later is selected and executed according to the judgment result (step S104).

  That is, the control unit 41 determines that among sensors other than the sensor in which the abnormality has occurred, there is a sensor that switches on and off when the first shaft 14 reaches a position corresponding to a desired vehicle state from the movement start side. When it is determined, as a first switching processing method, the first shaft 14 is moved toward a position corresponding to a desired vehicle state, and by detecting on / off switching read from the sensor, It is determined that the first shaft 14 has been positioned at a position corresponding to a desired vehicle state (step S105).

  For example, when switching from the vehicle state “B” to the vehicle state “D” in FIG. 7 and it is specified that an abnormality has occurred in the second sensor SW2, the control unit 41 moves the first shaft 14 It is determined based on the table stored in the storage unit 42 that the third sensor P-SW switches from off to on when reaching the position corresponding to the vehicle state “D” from the start side. Then, the control unit 41 moves the first shaft 14 toward a position corresponding to the vehicle state of “D”, and detects switching from off to on read from the third sensor P-SW. , It is determined that the first shaft 14 has been positioned at a position corresponding to the vehicle state of “D”. As a result, even if an abnormality occurs in the second sensor SW2, it is possible to switch to the vehicle state of "D" which is a desired vehicle state, so that not only the traveling becomes impossible but also the traveling difficult state is avoided. Can be.

  The control unit 41 switches on / off when the first shaft 14 reaches a position corresponding to a desired vehicle state from the side opposite to the movement start side among the sensors other than the sensor in which the abnormality has occurred. If it is determined that there is a sensor, as a second switching processing method, the first shaft 14 is moved toward a position corresponding to a desired vehicle state, and the on / off switching read from the sensor is detected. After that, the first shaft 14 is moved in the opposite direction, and the on / off re-switching read from the sensor is detected, whereby the first shaft 14 is positioned at a position corresponding to a desired vehicle state. It is determined (step S106).

  For example, when switching from the vehicle state “B” to the vehicle state “C” in FIG. 7, if it is specified that an abnormality has occurred in the second sensor SW2, the control unit 41 moves the first shaft 14 The fact that the third sensor P-SW switches from on to off when reaching the position corresponding to the vehicle state of “C” from the opposite side to the start side is based on the table stored in the storage unit 42. to decide. And the control part 41 moves the 1st shaft 14 toward the position corresponding to the vehicle state of "C", and detects switching from OFF to ON read from the third sensor P-SW, It is determined that the first shaft 14 has passed the position corresponding to the vehicle state of “C”. Next, the control unit 41 moves the first shaft 14 in the opposite direction, and detects the re-switching from on to off read from the third sensor P-SW, so that the first shaft 14 is set to “C”. It is determined that the vehicle has been positioned at a position corresponding to the vehicle state. As a result, even if an abnormality occurs in the second sensor SW2, it is possible to switch to the vehicle state "C", which is the desired vehicle state, so that not only the traveling becomes impossible but also the traveling difficult state is avoided. Can be.

  When the control unit 41 determines that there is no sensor that switches on / off when the first shaft 14 reaches a position corresponding to a desired vehicle state, among the sensors other than the sensor in which the abnormality has occurred, Describes that as a third switching processing method, by moving the first shaft 14 based on the switching time stored in the storage unit 42, the first shaft 14 is positioned at a position corresponding to a desired vehicle state. A determination is made (step S107).

  For example, when switching from the vehicle state “D” to the vehicle state “B” in FIG. 7, when it is determined that an abnormality has occurred in the second sensor SW2, the control unit 41 sets the first shaft 14 to “ Based on the table stored in the storage unit 42, it is determined that neither the first sensor SW1 nor the third sensor P-SW switches on / off when the vehicle reaches the position corresponding to the vehicle state of "B". To judge. Next, the control unit 41 stores that the third sensor P-SW switches from on to off when the first shaft 14 reaches a position corresponding to the vehicle state of “C” from the movement start side. The determination is made based on the table stored in the unit 42. Then, the control unit 41 moves the first shaft 14 toward a position corresponding to the vehicle state of “C” and detects switching from on to off read from the third sensor P-SW by detecting the switching. , It is determined that the first shaft 14 is positioned at a position corresponding to the vehicle state of “C”. Subsequently, the control unit 41 moves the first shaft 14 over the switching time between the vehicle state of “C” and the vehicle state of “B” stored in the storage unit 42, thereby causing the first shaft 14 to move. It is determined that 14 has been positioned at a position corresponding to the vehicle state of "B". As a result, even if an abnormality occurs in the second sensor SW2, the vehicle can be switched to the desired vehicle state "B", so that not only the traveling becomes impossible but also the traveling difficult state is avoided. Can be.

  According to the present embodiment as described above, even when an abnormality occurs in the sensors SW1, SW2, and P-SW that detect the vehicle state, the sensor in which the abnormality has occurred is identified by the control unit 41, and the identified sensor By controlling the operation of the actuator 30 according to the combination of the vehicle state and the desired vehicle state, the first shaft 14 serving as the switching member can be positioned at a position corresponding to the desired vehicle state. Thereby, even if an abnormality occurs in the sensor, it is possible to switch to the desired vehicle state, so that not only the running becomes impossible, but also a state in which it is difficult to run can be avoided.

  In the present embodiment, the switching control device 4 includes the transfer device 10 and is configured to control switching between the two-wheel drive state and the four-wheel drive state in a four-wheel drive vehicle. The present invention is not limited to this. For example, the switching control device may include the transmission 3 and may be configured to control switching of the reduction ratio in the transmission 3.

  Next, the operation of the switching control device 4 according to the present embodiment will be described using an example.

(Example 1)
As the first embodiment, a table as shown in FIG. 7 is stored in the storage unit 42 as a combination pattern of ON / OFF when the sensors SW1, SW2, and P-SW are normal. A case will be described in which the on / off combination pattern as shown in FIG. 8 is read by the control unit 41 in each vehicle state due to the failure of the sensor SW2.

  In this case, when a switch instruction from the vehicle state of “B” to the vehicle state of “E” is input by the operation of the switch 43 by the user, the control unit 41 first changes the vehicle state of “B” to “C”. The first shaft 14 is moved in such a direction as to switch to the vehicle state of "", and (SW1, SW2, P-SW) = based on the moving direction of the first shaft 14 and the table stored in the storage unit 42. It is estimated that a combination pattern (corresponding to the vehicle state of “C” in FIG. 7) of (ON, ON, OFF) will be read next. Then, due to the failure of the second sensor SW2, the combination pattern of (SW1, SW2, P-SW) = (ON, OFF, OFF) (corresponding to the vehicle state of "C" in FIG. 8) was actually read. In this case, the control unit 41 compares the estimated on / off combination pattern with the on / off combination pattern actually read from each of the sensors SW1, SW2, and P-SW3, and thereby the second sensor It is specified that an abnormality has occurred in SW2.

  The control unit 41 stores in the storage unit 42 that an abnormality has occurred in the second sensor SW2. Thus, even after the ignition is once turned off, the abnormality processing can be continuously performed.

  Subsequently, the control unit 41 informs the storage unit 42 that the first sensor SW1 switches from on to off when the first shaft 14 reaches a position corresponding to the vehicle state of “E” from the movement start side. Is determined based on the table stored in the. Then, the control unit 41 moves the first shaft 14 from the position corresponding to the vehicle state of “C” to the position corresponding to the vehicle state of “E”, and from the on state read from the first sensor SW1. By detecting switching to off, it is determined that the first shaft 14 has been positioned at a position corresponding to the vehicle state of “E”. As a result, even if an abnormality occurs in the second sensor SW2, it is possible to switch to the vehicle state of "E" instructed by the user, so that not only running is not disabled but also running is prevented. it can.

  The control unit 41 stores in the storage unit 42 that the vehicle state has been switched to “E”. As a result, the final switching position can be remembered even after the ignition is once turned off.

  Next, when a switch instruction for returning the vehicle state of “E” to the vehicle state of “B” is input by the user operating the switch 43, the control unit 41 causes the first shaft 14 of the vehicle having the “B” Based on the table stored in the storage unit 42, it is determined that neither the first sensor SW1 nor the third sensor P-SW switches on / off when reaching the position corresponding to the state. Next, the control unit 41 stores that the third sensor P-SW switches from on to off when the first shaft 14 reaches a position corresponding to the vehicle state of “C” from the movement start side. The determination is made based on the table stored in the unit 42. Then, the control unit 41 moves the first shaft 14 toward a position corresponding to the vehicle state of “C” and detects switching from on to off read from the third sensor P-SW by detecting the switching. , It is determined that the first shaft 14 is positioned at a position corresponding to the vehicle state of “C”. Subsequently, the control unit 41 moves the first shaft 14 over the switching time between the vehicle state of “C” and the vehicle state of “B” stored in the storage unit 42, thereby causing the first shaft 14 to move. It is determined that 14 has been positioned at a position corresponding to the vehicle state of "B". As a result, even if an abnormality occurs in the second sensor SW2, it is possible to switch to the vehicle state of "B" instructed by the user, so that not only the running becomes impossible but also the running difficult state is avoided. it can.

  The control unit 41 stores in the storage unit 42 that the state has been switched to the vehicle state “B”. As a result, the final switching position can be remembered even after the ignition is once turned off.

(Example 2)
As a second embodiment, a table as shown in FIG. 9 is stored in the storage unit 42 as a combination pattern of ON / OFF when the sensors SW1 and SW2 are normal, but actually, a failure of the second sensor SW2 is performed. In the following, a description will be given of a case where the combination pattern of on / off as shown in FIG.

  In this case, when a switch instruction from the vehicle state of “B2” to the vehicle state of “D2” is input by the user operating the switch 43, the control unit 41 first changes the vehicle state of “B2” to “C2”. The first shaft 14 is moved in such a direction as to switch to the vehicle state of “.”, And (SW1, SW2) = (ON, ON) based on the moving direction of the first shaft 14 and the table stored in the storage unit 42. ) (Corresponding to the vehicle state of “C2” in FIG. 9) is estimated to be read next. However, when the combination pattern of (SW1, SW2) = (ON, OFF) (corresponding to the vehicle state of “C2” in FIG. 10) is actually read due to the failure of the second sensor SW2, the control unit 41 Specifies that an abnormality has occurred in the second sensor SW2 by comparing the estimated on / off combination pattern with the on / off combination pattern actually read from each of the sensors SW1 and SW2. .

  The control unit 41 stores in the storage unit 42 that an abnormality has occurred in the second sensor SW2. Thus, even after the ignition is once turned off, the abnormality processing can be continuously performed.

  Subsequently, the control unit 41 informs the storage unit 42 that the first sensor SW1 switches from on to off when the first shaft 14 reaches a position corresponding to the vehicle state of “D2” from the movement start side. Is determined based on the table stored in the. Then, the control unit 41 moves the first shaft 14 from the position corresponding to the vehicle state of “C2” toward the position corresponding to the vehicle state of “D2”, and from the ON state read from the first sensor SW1. By detecting the switching to the off state, it is determined that the first shaft 14 has been positioned at the position corresponding to the vehicle state of “D2”. As a result, even when an abnormality occurs in the second sensor SW2, it is possible to switch to the vehicle state of "D2" specified by the user, so that not only the running becomes impossible but also the running difficult state is avoided. it can.

  The control unit 41 stores in the storage unit 42 that the vehicle state has been switched to “D2”. As a result, the final switching position can be remembered even after the ignition is once turned off.

  Next, when a switch instruction to return from the vehicle state of “D2” to the vehicle state of “B2” is input by a user's operation of the switch 43, the control unit 41 determines that the first shaft 14 is in the movement start side. It is determined based on the table stored in the storage unit 42 that the first sensor SW1 switches from off to on when reaching the position corresponding to the vehicle state “B2” from the opposite side. Then, the control unit 41 moves the first shaft 14 toward a position corresponding to the vehicle state of “B2”, and detects the switching from on to off read from the first sensor SW1, thereby performing the first It is determined that the shaft 14 has passed the position corresponding to the vehicle state of “B2”. Next, the control unit 41 moves the first shaft 14 in the reverse direction and detects the re-switching from off to on read from the first sensor SW1, thereby detecting the vehicle whose first shaft 14 is “B2”. It is determined that the positioning has been performed at the position corresponding to the state. As a result, even if an abnormality occurs in the second sensor SW2, the vehicle state can be switched to the desired vehicle state "B2", so that not only the traveling becomes impossible but also the traveling difficult state is avoided. Can be.

  The control unit 41 stores in the storage unit 42 that the vehicle state has been switched to “B2”. Thereby, even after the ignition is once turned off, the last switching position can be remembered.

DESCRIPTION OF SYMBOLS 1 Vehicle 2 Engine 3 Transmission 4 Switching control device 5F Front differential 5R Rear differential 5F Front wheel 5R Rear wheel 10 Transfer device 11 First output shaft 12 Second output shaft 13 Center differential unit 14 First shaft (switching member)
15 Second shaft 14A, 15A Large diameter portion 16 Two-wheel / four-wheel shift fork 17 Center flock shift fork 16A, 17A Sleeve 19 Silent chain 20 High & low shift lever 24 Input shaft 30 Actuator 31 Output gear 36 Worm gear 37 Waiting mechanism 38 Worm wheel 39 Motor 41 Control unit 42 Storage unit 43 Switch SW1, SW2, P-SW sensor

Claims (7)

A switching member for switching the vehicle state according to the position,
A plurality of sensors for detecting the position of the switching member;
An actuator for driving the switching member,
A storage unit that stores a table that associates a combination pattern of on / off states of the plurality of sensors in a normal state with respect to each vehicle state, and reads out the table stored in the storage unit and the plurality of sensors; A control unit that controls the operation of the actuator, based on the combined ON / OFF combination pattern, so that the switching member is positioned at a position corresponding to a desired vehicle state.
With
If it is determined that an abnormality has occurred in any of the plurality of sensors, the control unit uses the combination pattern of on and off read from the plurality of sensors, the sensor in which the abnormality has occurred In accordance with the combination of the specified sensor and the desired vehicle state, the switching member is positioned at a position corresponding to the desired vehicle state by using a table stored in the storage unit. Controlling the operation of the actuator ,
The control unit stores an on / off combination pattern read from the plurality of sensors at the time of ignition off in the storage unit, and an on / off combination pattern read from the plurality of sensors at the time of ignition on. A switching control device characterized in that a sensor in which an abnormality has occurred is specified by comparing the combination with an on / off combination pattern at the time of ignition off stored in the storage unit . The control unit moves the switching member to change an on / off combination pattern read from the plurality of sensors, and based on a moving direction of the switching member and a table stored in the storage unit. By estimating the on / off combination pattern in the normal state of the plurality of sensors, and comparing the estimated on / off combination pattern with the on / off combination pattern read from the plurality of sensors, The switching control device according to claim 1, wherein a sensor in which an abnormality has occurred is specified. The storage unit stores a switching time required for switching each vehicle state,
The control unit moves the switching member over a switching time stored in the storage unit for a time equal to or longer than the switching time, and turns on / off the plurality of sensors in a normal state based on a table stored in the storage unit. By estimating the combination pattern of the on and off, and comparing the estimated on / off combination pattern with the on / off combination pattern read from the plurality of sensors, it is possible to identify the sensor in which the abnormality has occurred. The switching control device according to claim 1 or 2 , wherein Wherein the control unit, the switching control device according to any one of claims 1 to 3, characterized in that storing the sensor specified in the storage unit. The control unit, after specifying the sensor in which the abnormality has occurred, among the sensors other than the sensor in which the abnormality has occurred, turns on when the switching member reaches a position corresponding to a desired vehicle state from the movement start side. It is determined based on a table stored in the storage unit whether or not there is a sensor for switching off, and when it is determined that the sensor is present, the switching member is turned to a position corresponding to a desired vehicle state. And detecting the on / off switching read from the sensor to determine that the switching member has been positioned at a position corresponding to a desired vehicle state. The switching control device according to any one of claims 1 to 4 . The control unit, after specifying the sensor in which the abnormality has occurred, among the sensors other than the sensor in which the abnormality has occurred, the switching member reaches a position corresponding to a desired vehicle state from the side opposite to the movement start side. At this time, it is determined whether or not there is a sensor that switches on and off based on a table stored in the storage unit, and when it is determined that the sensor is present, the switching member corresponds to a desired vehicle state. After detecting the on / off switching read from the sensor, and then moving the switching member in the opposite direction to detect on / off re-switching read from the sensor. The switching control device according to any one of claims 1 to 5 , wherein it is determined that the switching member is positioned at a position corresponding to a desired vehicle state. The storage unit stores a switching time required for switching each vehicle state,
The control unit, after identifying the sensor in which the abnormality has occurred, among sensors other than the sensor in which the abnormality has occurred, a sensor that switches on / off when the switching member reaches a position corresponding to a desired vehicle state Is determined based on a table stored in the storage unit, and when it is determined that there is no sensor, the switching member is moved based on the switching time stored in the storage unit. The switching control device according to any one of claims 1 to 6 , wherein it is determined that the switching member has been positioned at a position corresponding to a desired vehicle state.