JP2004108540A - Transmission controller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To have a fine driving performance of the vehicles without limitation of a transmission step by a position such as range at the time of fail safe while it makes possible to change speed without operating a special emergency device. <P>SOLUTION: ECT-ECU makes SBW-ECU (S108 to S112) to set up a range that can attain an aimed transmission step without relating to a driver's operation when either or both of the first and the second transmission solenoid valve are detected to be failure. Consequently, the transmission step that is restricted by the failure can be increased and the smooth limp home running by an automatic transmission becomes possible (S114) even if the special emergency device for the time of fail-safe is not installed. Special operation is not required for the driver against the emergency device to change the speed because the special device for an emergency is not provided. Because of this, the driving performance of the vehicles at the time of fail-safe can be improved to be fine. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a shift control for electrically shifting a position switching mechanism of a vehicular transmission in accordance with an operation state of a position switching operation unit and executing a shift by driving a gear position switching mechanism corresponding to a corresponding position. Equipment related.
[0002]
[Prior art]
In an electronically controlled vehicle automatic transmission, supply and discharge of hydraulic pressure to and from a control port of a shift valve are performed by a shift solenoid valve. When a failure such as disconnection or short-circuit occurs in the shift solenoid valve, a shift stage that cannot be established occurs, and limp home traveling (retreat traveling) may be difficult.
[0003]
In order to prevent this limp home traveling difficulty, a shift valve for switching between a certain shift speed and a higher speed shift speed is provided with a second control port to which line oil pressure is applied at a specific position (range), There is a technology that secures establishment of a first speed stage and a second speed stage at a specific position (range) to achieve fail-safe (for example, see Patent Document 1).
[0004]
In the event of a failure, the emergency switching valve is switched to the emergency side and the manual operation unit is operated to control the emergency directional control valve, thereby ensuring manual switching between the forward one stage and the reverse. (For example, see Patent Document 2).
[0005]
Further, an emergency switch device provided with two neutral switching positions between a reverse gear ratio and a forward gear ratio selection position enables manual low-speed operation or running-off-road operation at a limited gear stage. (For example, see Patent Document 3).
[0006]
[Patent Document 1]
JP-A-2-125165 (page 10, FIGS. 8, 9)
[Patent Document 2]
JP-A-63-243554 (pages 3, 4; table 1)
[Patent Document 3]
JP-A-2-266159 (page 8, FIGS. 2 and 3)
[0007]
[Problems to be solved by the invention]
As described above, in the prior art, at the time of a fail-safe operation, the vehicle must travel at a limited gear at a specific position, or an emergency switching valve or an emergency switch device is provided in advance for fail-safe operation. When shifting gears in the safe mode, it is necessary to operate these devices. Therefore, there is a problem that the vehicle drivability during fail-safe is not good.
[0008]
The present invention improves vehicle drivability by failing to be limited by the position of a range or the like at the time of fail-safe and without operating a specially provided emergency device. It is intended to be.
[0009]
[Means for Solving the Problems]
Hereinafter, the means for achieving the above object and the effects thereof will be described.
The shift control device according to claim 1, wherein the position switching mechanism of the vehicle transmission is electrically linked with the operation state of the position switching operation unit, and the shift position switching mechanism is driven in accordance with the corresponding position. A shift control device for performing a shift by the shift speed changeover mechanism, wherein a shift speed changeover failure detecting means for detecting a malfunction of the shift speed changeover mechanism; and A failure position switching means for increasing the number of achievable gears by executing position switching by the switching mechanism independently of the position switching operation section is provided.
[0010]
For example, when the driver operates the position switching operation unit to a specific position such as the D range and travels, if a failure of the gear position switching mechanism occurs, the gear position that is established from a normal state is limited. You. However, in a position where the operator does not designate on the position switching operation section, a new shift speed may be realized even if the same shift speed switching mechanism is out of order.
[0011]
Therefore, according to the present invention, when the failure of the gear position switching mechanism is detected by the gear position switching failure detecting means, the failure position switching means switches the position switching by the position switching mechanism to the position switching operation operated by the driver. By executing the operation independently of the operation unit, the number of achievable gears is increased. As a result, without specially providing an emergency device for use in fail-safe operation, the gear position limited by the failure can be increased without being limited by the gear position due to the position, and the automatic gear shift can be performed smoothly. Limp home driving becomes possible.
[0012]
Moreover, since the emergency device is not specially provided, the driver does not have to perform any special operation on the emergency device for shifting.
For this reason, the vehicle drivability during fail-safe can be improved.
[0013]
According to a second aspect of the present invention, in the first aspect, the transmission is driven to shift by hydraulic pressure, and the position switching mechanism and the shift position switching mechanism are hydraulic switching valves. .
[0014]
In such a transmission that is driven by the hydraulic pressure, the hydraulic pressure cannot be switched due to the failure of the gear position switching mechanism, and some or all of the gear positions cannot be established at each position. In this case, the failure-time position switching means uses a gear position that cannot be established due to the failure in the position selected by the driver in the position switching operation unit, and utilizes a gear position that is established in other positions. The position switching is executed so as to be realized or to realize another shift speed. As a result, in the fail-safe mode, the gear position is not restricted by the position, and the emergency device specially provided for shifting is not operated, so that the vehicle drivability in the fail-safe mode is improved. It can be.
[0015]
According to a third aspect of the present invention, in the second aspect, the speed change mechanism is an electromagnetic valve, and the speed change failure detecting means can normally energize the shift solenoid driving the electromagnetic valve. It is characterized in that the disappearance of the shift stage is detected as a failure of the speed change mechanism.
[0016]
Here, the shift speed switching failure detecting means detects that the shift speed switching mechanism is faulty when the power supply to the shift solenoid of the shift speed switching mechanism cannot be normally performed. For example, a failure of the speed change mechanism can be easily determined by detecting disconnection or short-circuit of the speed change solenoid, and by appropriately increasing the number of gears by the failure position switching means, the vehicle drivability at the time of fail-safe can be improved. Things.
[0017]
According to a fourth aspect of the present invention, there is provided the speed change control device according to any one of the first to third aspects, further comprising: a failure automatic transmission means for executing an automatic shift corresponding to the number of shift steps achievable by the failure position switching means. It is characterized by having.
[0018]
By providing such an automatic transmission at the time of a failure, automatic transmission can be performed as smoothly as possible even in the fail-safe mode, and vehicle drivability in the fail-safe mode can be improved.
[0019]
According to a fifth aspect of the present invention, in the shift control device according to the fourth aspect, the failure position switching means is configured to change the position in accordance with a position required for realizing a required gear position by the failure automatic transmission means. The switching of the position by the switching mechanism is performed.
[0020]
In this way, the position switching means at the time of failure executes the position switching in response to the request of the automatic transmission means at the time of failure, so that automatic shifting can be performed as smoothly as possible even in the fail-safe state, thereby improving the vehicle drivability in the fail-safe state. It can be.
[0021]
BEST MODE FOR CARRYING OUT THE INVENTION
[Embodiment 1]
FIG. 1 is a block diagram illustrating a schematic configuration of a vehicle shift control device to which the above-described invention is applied. The automatic transmission 2 shown in FIG. 1 is configured as a shift-by-wire automatic transmission. Note that, in the present embodiment, the shift control is described as an example of a type in which the forward position is switched over a predetermined range, but may be a predetermined gear (fixed type). The same applies to other embodiments.
[0022]
The automatic transmission 2 includes, as a transmission mechanism, a torque converter 6 having a lock-up clutch 4, a second transmission section 8 having a set of planetary gear mechanisms, and a plurality of forward gears and reverse travels by two sets of planetary gear mechanisms. A first transmission unit 10 for setting a gear is provided.
[0023]
The second transmission section 8 performs high-low switching between two stages. The carrier 12 of the planetary gear mechanism is connected to the turbine runner 14 of the torque converter 6. A clutch C0 and a one-way clutch F0 are provided between the carrier 12 and the sun gear 16 so as to be in a parallel relationship with each other, and a brake B0 is provided between the sun gear 16 and the housing 18.
[0024]
The sun gears 20 and 22 in each planetary gear mechanism of the first transmission unit 10 are provided on a common sun gear shaft 24, and the ring gear 26 and the second gear in the planetary gear mechanism on the left side (front side) of the first transmission unit 10 in the drawing. The first clutch C <b> 1 is provided between the second transmission unit 8 and the ring gear 28. A second clutch C2 is provided between the sun gear shaft 24 and the ring gear 28 of the second transmission unit 8. The carrier 30 of the planetary gear mechanism on the left side in the drawing and the ring gear 32 of the planetary gear mechanism on the right (rear side) in the first transmission unit 10 are integrally connected, and the output shaft is connected to the carrier 30 and the ring gear 32. 34 are connected.
[0025]
The first brake B1, which is a band brake, is provided so as to stop the rotation of the sun gear shaft 24, and more specifically, is provided on the outer peripheral side of the clutch drum of the second clutch C2. A first one-way clutch F1 and a second brake B2 are arranged in series between the sun gear shaft 24 and the housing 18, and a first one-way clutch F1 and a second brake B2 are arranged between the carrier 36 and the housing 18 in the rear planetary gear mechanism. The two-way clutch F2 and the third brake B3 are arranged in parallel.
[0026]
The hydraulic control device 40 supplies and discharges hydraulic pressure to the clutches C0, C1, C2, the brakes B0, B1, B2, B3, and the lock-up clutch 4. The hydraulic control device 40 includes first and second shift solenoid valves S1 and S2 for mainly executing first to fourth speed shifts, and a linear solenoid valve SLU for mainly controlling the lock-up clutch 4. And a rotary valve RV for switching the range by the line oil pressure. Among these valves S1, S2, SLU, RV, a shift electronic control unit (hereinafter referred to as an ECT-ECU) 42 for driving and controlling the first and second shift solenoid valves S1, S2 and the linear solenoid valve SLU. Is provided. A shift-by-wire electronic control unit (hereinafter, referred to as an SBW-ECU) 44 for range switching is provided to drive and control the rotary valve RV via the electric motor M. Each of these ECUs 42 and 44 is configured as a microcomputer having a central processing element, a storage element, and an input / output interface.
[0027]
The ECT-ECU 42 receives a throttle opening signal, a vehicle speed signal, a pattern select signal, a signal from the SBW-ECU 44, and other signals (engine water temperature signal, brake signal, and the like). The ECT-ECU 42 selects an appropriate shift map from a group of shift maps corresponding to shift diagrams stored in advance based on these input signals, and calculates a gear to be set from the shift map. And outputs a signal to the first and second shift solenoid valves S1 and S2 to set the shift speed. Further, it outputs a signal to the linear solenoid valve SLU as required.
[0028]
On the other hand, the SBW-ECU 44 has a range selection switch for selecting a parking range (P), a reverse range (R), a neutral range (N), a drive range (D), a 2 range (2), and an L range (L). 46 is connected, and a range selection signal is input. Further, the SBW-ECU 44 receives a valve position signal from a position sensor 47 that detects the range switching position of the rotary valve RV, and various request signals as described later from the ECT-ECU 42. Accordingly, the SBW-ECU 44 controls the electric motor M to rotate the rotary valve RV based on the valve position signal from the position sensor 47 so that the range selected by the driver with the range selection switch 46 or a required range described later is set. Drive control. At the same time, a signal indicating the range position is output to the ECT-ECU 42 and a range display (not shown).
[0029]
In the automatic transmission 2 described above, as shown in the operation table of FIG. 2, the first and second shift solenoid valves S1 and S2 are controlled to be ON (ＯＦＦ) and OFF (×) so that each friction engagement portion is controlled. The clutches, brakes, and one-way clutches are engaged and disengaged as shown in the operation table of FIG. In FIG. 2, for each frictional engagement portion, the mark “○” indicates that the engagement may be performed, and the blank indicates that the frictional engagement may be either the release or the engagement / release.
[0030]
Next, in the present embodiment, of the control executed by the ECT-ECU 42 and the SBW-ECU 44, a control process in a normal state will be described.
In normal times, the SBW-ECU 44 switches the rotary valve RV according to the selection of the range selection switch 46 to set the shift range. As a result, the line hydraulic pressure in the hydraulic control device 40 is set. In accordance with the range set by the SBW-ECU 44, the ECT-ECU 42 sets the gear position determined based on the shift map selected according to the pattern select signal as shown in FIG. The ON / OFF of the one- and two-speed solenoid valves S1 and S2 is controlled.
[0031]
Next, the shift solenoid abnormal control process will be described. 3 is an ECT shift solenoid abnormality control process executed by the ECT-ECU 42, FIG. 4 is a range-dependent shift stage setting process executed by the ECT-ECU 42, and FIG. 5 is an SBW shift solenoid executed by the SBW-ECU 44. 3 shows a control process.
[0032]
The ECT shift solenoid abnormal control process (FIG. 3) will be described. This process is a process repeatedly executed in a short control cycle.
When the present process is started, it is first determined whether or not the speed-change solenoids incorporated for driving the first and second speed-change solenoid valves S1 and S2 are abnormal (S102). The ECT-ECU 42 detects the abnormality of the gearshift solenoid in a separate determination process by detecting the energized state of each gearshift solenoid by a voltage sensor, a current sensor, or the like. Is determined to be abnormal when the contact is made. Therefore, in step S102, by reading the result of this determination processing, it is determined whether at least one of the first and second shift solenoid valves S1 and S2 is abnormal.
[0033]
If both the first and second transmission solenoid valves S1 and S2 have no abnormality in the transmission solenoid ("NO" in S102), the process is once terminated. When there is no abnormality in both the shift solenoids, the first and second shift solenoids are operated as shown in FIG. ON / OFF of the valves S1 and S2 is executed.
[0034]
When abnormality of the shift solenoid is detected in one or both of the first and second shift solenoid valves S1 and S2 ("YES" in S102), it is determined whether or not there is a request for limp home travel. Is performed (S104). For example, when the driver selects a range with the range selection switch 46 and depresses the accelerator pedal to start traveling, it is determined that there is a limp home traveling request.
[0035]
Here, if there is no limp home traveling request ("NO" in S104), this processing is terminated as it is. As a result, no power is supplied to the transmission solenoids of the first and second transmission solenoid valves S1 and S2, and no transmission control is performed.
[0036]
If there is a limp home traveling request ("YES" in S104), then a limp home shift request is transmitted to SBW-ECU 44 (S106). As a result, the SBW-ECU 44 enters a mode for performing a limp home shift as described later.
[0037]
Then, the target shift speed is calculated from the accelerator opening and the vehicle speed based on the shift map (S108). The shift map in this case may be a shift map for normal running, or a shift map specially set for limp home running.
[0038]
Then, a target range for establishing the target shift speed is calculated (S110). FIG. 6 shows the possible gear positions in each range when one or both of the first and second shift solenoid valves S1 and S2 are abnormal.
[0039]
As shown in the figure, when the first speed change solenoid valve S1 is abnormal and the second speed change solenoid valve S2 is normal, only the second speed change solenoid valve S2 is turned on and off, and the third speed and the fourth speed are set in the D range. The speed range is limited to the third speed in the second range, and to the first speed and the second speed in the L range. In the second range, the OFF of the second speed-change solenoid valve S2 is not executed because the line hydraulic pressure does not function properly.
[0040]
However, independently of the selection state of the range selection switch 46, if all of the D range, the second range, and the L range are used, all of the first to fourth speeds are performed by ON / OFF drive of only the second speed change solenoid valve S2. Can be realized.
[0041]
When the first speed change solenoid valve S1 is normal and the second speed change solenoid valve S2 is abnormal, only the first speed change solenoid valve S1 is driven to switch between the first speed and the fourth speed in the D range. The speed range is limited to the first speed and the third speed in the range, and to the first speed in the L range. In the L range, turning off the first speed-change solenoid valve S1 is not executed because the line oil pressure does not function properly.
[0042]
In this case, if all of the D range, the second range, and the L range are used independently of the selection state of the range selection switch 46, the first speed, the third speed, and the third speed are controlled by ON / OFF driving of only the first speed change solenoid valve S1. It is possible to realize the fourth speed.
[0043]
If both the first and second shift solenoid valves S1 and S2 are abnormal, the two shift solenoid valves S1 and S2 are fixed, so that the fourth speed in the D range and the third speed in the second range. In the L range, the shift speed is limited to the first speed.
[0044]
In this case, if the D range, the 2 range, and the L range are all used independently of the selection state of the range selection switch 46, the first speed, the third speed, and the third speed can be used even if both the shift solenoid valves S1 and S2 are fixed. It is possible to realize the fourth speed.
[0045]
Therefore, in step S110, it is determined whether there is a range in which the target shift speed calculated in step S108 can be realized based on the state of the abnormality of the shift solenoid, and if there is a corresponding range, the range is set as the target range. For example, when the first shift solenoid valve S1 is abnormal and the second shift solenoid valve S2 is normal, there is always a corresponding range because there are all shift speeds for moving forward in the range.
[0046]
In addition, when the first shift solenoid valve S1 is normal and the second shift solenoid valve S2 is abnormal, or when both the first and second shift solenoid valves S1 and S2 are abnormal, the second shift solenoid valve S1 is in any range. Only speed cannot be realized. Therefore, in this case, if the second speed is the target shift speed in step S108, the corresponding range does not exist. In this case, for example, a range in which the lower gear (first speed) or the upper gear (third speed) can be realized is calculated as the target range.
[0047]
Next, the target range calculated in this way is transmitted to the SBW-ECU 44 as a required range (S112). As a result, the SBW-ECU 44 switches the rotary valve RV to the target range regardless of the setting of the range selection switch 46, as described later.
[0048]
Next, a range-dependent gear position setting process is executed (S114). The details of the range-dependent gear position setting process are as shown in FIG. In the present process, first, it is determined from the contents of the set range transmitted from the SBW-ECU 44 whether or not the target range requested by the SBW-ECU 44 is realized in step S112 of FIG. 3 (S116). If the target range has not been achieved, the current state is maintained (S118), and this process is temporarily terminated.
[0049]
If the actual range is the target range ("YES" in S116), it is determined whether the current range is other than the D range (S120). Here, if it is in the D range ("NO" in S120), as shown in FIG. 6, the shift solenoid valve which is not abnormal in the D range is driven, or if both are abnormal, the target solenoid is not driven and the target shift is performed. The step is realized (S122).
[0050]
For example, when the first shift solenoid valve S1 is abnormal, the fourth speed is calculated as the target shift speed (S108 in FIG. 3), and the D range is calculated as a range for realizing the third speed (FIG. 3). S110), it is assumed that the D range is requested to the SBW-ECU 44 (S112 in FIG. 3). Accordingly, if the SBW-ECU 44 switches to the D range by the rotary valve RV (“YES” in S116, “NO” in S120), in step S122, the second shift solenoid valve S2 is turned off as shown in FIG. This realizes the fourth speed. Note that, when the third speed is the target shift speed, this is realized by turning on the second shift solenoid valve S2 in the D range.
[0051]
On the other hand, if the current range is other than the D range ("YES" in S120), it is determined whether the current range is other than the two ranges (S124). Here, if the range is two ranges ("NO" in S124), as shown in FIG. 6, the non-abnormal shift solenoid valve in the two ranges is driven, or if both are abnormal, the target solenoid is not driven and the target shift is performed. The step is realized (S126).
[0052]
For example, when the first shift solenoid valve S1 is abnormal, the third speed is calculated as the target shift speed (S108 in FIG. 3), and two ranges are calculated as the range for realizing the third speed (FIG. 3). S110), it is assumed that the SBW-ECU 44 has requested two ranges (S112 in FIG. 3). As a result, if the SBW-ECU 44 sets the two ranges by the rotary valve RV (“YES” in S116, “YES” in S120, “NO” in S124), in step S126, the second speed change solenoid as shown in FIG. The third speed is realized by turning on the valve S2.
[0053]
On the other hand, if the current range is outside the L range ("YES" in S124), it is determined whether the current range is outside the L range (S128). Here, if it is in the L range ("NO" in S128), as shown in FIG. 6, the shift solenoid valve which is not abnormal in the L range is driven, or if both are abnormal, the target solenoid is not driven and the target shift is performed. The step is realized (S130).
[0054]
For example, when the first shift solenoid valve S1 is abnormal, the second speed is calculated as the target shift speed (S108 in FIG. 3), and the L range is calculated as a range for realizing the second speed (FIG. 3). S110), it is assumed that the L range is requested to the SBW-ECU 44 (S112 in FIG. 3). If the SBW-ECU 44 switches to the L range by the rotary valve RV ("YES" in S116, "YES" in S120, "YES" in S124, "NO" in S128), as shown in FIG. As described above, the second speed is realized by turning on the second shift solenoid valve S2. If the first speed is the target shift speed, this is realized by turning off the second shift solenoid valve S2 in the L range.
[0055]
On the other hand, if the range is other than the L range ("YES" in S128), the present process is ended once.
As described above, when the first shift solenoid valve S1 is abnormal and the second shift solenoid valve S2 is normal, the second shift solenoid valve S2 is turned on and off, and the range is switched by the rotary valve RV. All of the first to fourth speeds can be realized.
[0056]
When the first speed change solenoid valve S1 is normal, but the second speed change solenoid valve S2 is abnormal, when the first speed is calculated as the target shift speed (S108 in FIG. 3), as shown in FIG. 6, The ranges in which the first speed can be realized are the D, 2, and L ranges. Therefore, for example, the D range is calculated as the target range (S110 in FIG. 3), and a request for the D range is made to the SBW-ECU 44 (S112 in FIG. 3). As a result, if the SBW-ECU 44 switches to the D range by the rotary valve RV (“YES” in S116, “NO” in S120), in step S122, the first speed-change solenoid valve S1 is turned on as shown in FIG. Thus, the first speed is realized.
[0057]
In addition, when the SBW-ECU 44 is requested to set the 2nd or L range as the target range in response to the calculation of the first speed as the target shift speed (S110, S112 in FIG. 3), the first speed is set in step S126 or S130. The first speed can be realized by turning on the shift solenoid valve S1.
[0058]
When the second speed is calculated as the target shift speed, there is no range in which the second speed can be realized as shown in FIG. Therefore, as described above, a range that can realize the next lower gear or the upper gear is calculated as the target range. If the first speed is realized, one of the D, 2 and L ranges is set as the target range, and if the third speed is realized, two ranges are set as the target range. For example, in the case of realizing the third speed, the SBW-ECU 44 is requested to have two ranges. As a result, in step S126, the first shift solenoid valve S1 is turned off as shown in FIG. 6 in order to realize the shift speed one step higher than the target shift speed, here, the third speed.
[0059]
When the third speed is calculated as the target shift speed, there are two ranges in which the third speed can be realized as shown in FIG. Therefore, the SBW-ECU 44 is requested to set the two ranges as the target ranges. Thus, in step S126, the third speed is realized by turning off the first speed change solenoid valve S1 as shown in FIG.
[0060]
When the fourth speed is calculated as the target shift speed, the range in which the fourth speed can be realized as shown in FIG. 6 is the D range. Therefore, the D range is calculated as the target range and requested to the SBW-ECU 44. Thus, in step S122, the fourth speed is realized by turning off the first speed change solenoid valve S1 as shown in FIG.
[0061]
When both the first and second shift solenoid valves S1 and S2 are abnormal, the shift speed is set only by switching the range. That is, when the first speed is calculated as the target gear (S108 in FIG. 3), the range in which the first speed can be realized is the L range as shown in FIG. Therefore, the L range is calculated as the target range and requested to the SBW-ECU 44 (S110, S112 in FIG. 3). Thus, the driving process is not performed in step S130, but the first speed is realized as shown in FIG.
[0062]
When the second speed is calculated as the target shift speed, there is no range in which the second speed can be realized as shown in FIG. Therefore, in this case, in step S110 of FIG. 3, a range in which the lower gear or the upper gear can be realized is calculated as the target range. If the first speed is realized, the L range is set as the target range, and if the third speed is realized, two ranges are set as the target range. If the first speed is realized, the processing is performed in the same manner as in the case where the first speed is set as the target shift speed as described above. If the third speed is realized, the same processing is performed as when the next third speed is set as the target shift speed.
[0063]
When the third speed is calculated as the target shift speed, there are two ranges in which the third speed can be realized as shown in FIG. Therefore, two ranges are calculated as the target ranges and the SBW-ECU 44 is requested. Thus, the driving process is not performed in step S126, but the third speed is realized as shown in FIG.
[0064]
When the fourth speed is calculated as the target shift speed, the range in which the fourth speed can be realized is the D range as shown in FIG. Therefore, the D range is calculated as the target range and requested to the SBW-ECU 44. Thus, the driving process is not executed in step S122, but the fourth speed is realized as shown in FIG.
[0065]
Here, the SBW shift solenoid abnormal control process (FIG. 5) executed by the SBW-ECU 44 will be described. This process is a process repeatedly executed in a short period. When this processing is started, it is first determined whether or not a limp home shift request is being made (S202). If the limp home shift request has not been transmitted from the ECT-ECU 42 in the ECT shift ECU abnormality control process (FIG. 3) of the ECT-ECU 42 described above ("NO" in S202), the limp home shift mode is not entered. This process ends as it is. Therefore, the SBW-ECU 44 executes control for driving the rotary valve RV so as to realize a range corresponding to the content selected by the range selection switch 46 by a separate process (not shown).
[0066]
On the other hand, if the limp home shift request has been transmitted from the ECT-ECU 42 ("YES" in S202), the vehicle enters the limp home shift mode to determine first whether or not the vehicle is stopped (S204). If the vehicle is stopped ("YES" in S204), the rotary valve RV is driven to the L range (S206). As shown in FIG. 6, regardless of which of the first and second speed-change solenoid valves S1 and S2 is abnormal, the first speed, which is the shift speed at the start, always exists in the L range. Therefore, if the vehicle is set to the L range before the start of traveling, quick start is possible. In this case, the ECT-ECU 42 implements the first speed in the L range when starting. When the vehicle is stopped, the range may be set according to the range required by the ECT-ECU 42 instead of being set to the L range.
[0067]
If the vehicle is running ("NO" in S204), then, in accordance with the processing in step S112 in FIG. The valve RV is driven (S208). Thus, the SBW-ECU 44 realizes a range according to the request of the ECT-ECU 42 independently of the range selection switch 46.
[0068]
In the above-described configuration, the range selection switch 46 corresponds to a position switching operation unit, the rotary valve RV corresponds to a position switching mechanism, and the first and second speed-change solenoid valves S1 and S2 correspond to a speed changeover mechanism. The processing performed by the ECT-ECU 42 to determine the disconnection or short-circuit of the transmission solenoids of the first and second transmission solenoid valves S1 and S2 corresponds to the processing as the speed change failure detecting means. The ECT shift solenoid abnormal control process (FIG. 3), the range-dependent shift stage setting process (FIG. 4), and the SBW shift solenoid abnormal control process (FIG. 5) are processes as a failure position switching unit and a failure automatic transmission unit. Is equivalent to
[0069]
According to the first embodiment described above, the following effects can be obtained.
(I). When the failure of one or both of the first and second shift solenoid valves S1 and S2 is detected, the SBW-ECU 44 requests the ECT-ECU 42 independently of the range selection switch 46 operated by the driver. The rotary valve RV drive corresponding to the range is executed. As a result, it is possible to increase the number of gears that are limited in one range when a failure occurs.
[0070]
For example, when the first speed change solenoid valve S1 is abnormal and the second speed change solenoid valve S2 is normal, the hydraulic pressure related to the first speed change solenoid valve S1 cannot be switched. For this reason, as shown in FIG. 6, if the gear is fixed to the D range, the gears are limited to the third and fourth gears, the gears are limited to the third gear in the two ranges, and the first gear and the gears in the L range. Limited to 2nd speed. However, since the SBW-ECU 44 realizes a range corresponding to the required range on the ECT-ECU 42 side in step S208 of the SBW shift solenoid abnormality control process (FIG. 5), the first to fourth speeds are realized. It becomes possible.
[0071]
Further, when the first shift solenoid valve S1 is normal but the second shift solenoid valve S2 is abnormal, the hydraulic pressure related to the second shift solenoid valve S2 cannot be switched. For this reason, as shown in FIG. 6, if the gear is fixed to the D range, the gear is limited to the first and fourth gears, the gear is limited to the first and third gears in the two range, and the gear is limited to the first gear and the third gear in the L range. Limited to first speed. However, since the SBW-ECU 44 realizes the range corresponding to the required range on the ECT-ECU 42 side as described above, it is possible to realize the first, third, and fourth speeds.
[0072]
Further, when both the first and second shift solenoid valves S1 and S2 are abnormal, the hydraulic pressure related to the first and second shift solenoid valves S1 and S2 cannot be switched. Therefore, as shown in FIG. 6, if the gear is fixed to the D range, the gear is limited to the fourth gear, the gear is limited to the third gear in the two gears, and the gear is limited to the first gear in the L gear. However, since the SBW-ECU 44 realizes the range corresponding to the required range on the ECT-ECU 42 side as described above, it is possible to realize the first, third, and fourth speeds.
[0073]
Since the number of shift speeds that can be realized is increased in this way, it is possible to increase the shift speed limited due to a failure without providing a special emergency device for fail-safe operation. This enables smooth limp home travel. Moreover, since no special emergency device is provided, it is not necessary for the driver to perform a special operation on the emergency device for shifting. For this reason, the vehicle drivability during fail-safe can be improved.
[0074]
(B). Since the first and second shift solenoid valves S1 and S2 are solenoid valves, a failure can be easily determined by detecting a disconnection or a short circuit, and the number of shift stages can be accurately increased. As a result, vehicle drivability during fail-safe can be improved.
[0075]
[Embodiment 2]
In this embodiment, an ECT shift solenoid abnormal control process shown in FIG. 7 is executed instead of the ECT shift solenoid abnormal control process (FIG. 3). The other configuration is the same as that of the first embodiment.
[0076]
The ECT shift solenoid abnormal control process (FIG. 7) will be described. Note that the same processes as those in FIG. 3 are denoted by the same step numbers.
First, steps S102 to S106 are the same as those in FIG. After the limp home shift request is transmitted to the SBW-ECU 44 in step S106, a shift map corresponding to the abnormality of the shift solenoid is set next (S107). As described with reference to FIG. 6, in the automatic transmission 2 according to the present embodiment, when the first shift solenoid valve S1 is abnormal, the shift speed from the first speed to the fourth speed can be achieved by switching the range. is there. However, when the first speed change solenoid valve S1 is abnormal and when both speed change solenoid valves S1 and S2 are abnormal, the first speed, the third speed and the fourth speed can be realized even if the range switching is executed. Second gear cannot be realized.
[0077]
For this reason, there are two types of shift maps that are used in advance when the shift solenoid is abnormal: a shift map that allows the first to fourth speeds and a shift map that allows only the first, third, and fourth speeds. Is designed and stored in the ROM of the ECT-ECU 42. Then, at the time of execution of step S107, a shift map corresponding to the abnormality content of the shift solenoid is selected from the two types of shift maps, and set as a shift map used for shift control at the time of abnormality.
[0078]
The target shift speed is calculated from the accelerator opening and the vehicle speed using the shift map set according to the content of the abnormality of the shift solenoid (S108).
Then, a target range for establishing the target shift speed is calculated (S111). Here, since the target shift speed is calculated from the shift map corresponding to the abnormality content of the shift solenoid in step S107, the range in which the target shift speed can be realized always exists in the D, 2, and L ranges. Therefore, as described in step S110 of FIG. 3, there is no gear position in any of the ranges, so that the range is not determined by shifting the gear position.
[0079]
Next, the target range calculated in this way is transmitted to the SBW-ECU 44 as a required range (S112). Then, the gear position setting process corresponding to the range (S114) is executed, and the present process is ended once.
[0080]
In the above-described configuration, the ECT shift solenoid abnormal control process (FIG. 7), the range-responsive shift stage setting process (FIG. 4), and the SBW shift solenoid abnormal control process (FIG. 5) are performed by the fault position switching means and the fault automatic control. This corresponds to processing as a speed change means.
[0081]
According to the second embodiment described above, the following effects can be obtained.
(I). The effects (a) and (b) of the first embodiment are obtained.
(B). Since the shift map corresponding to the content of the abnormality of the shift solenoid can be used by the process of step S107, the limp home traveling by the automatic shift can be performed more smoothly, and the vehicle drivability during fail-safe can be further improved. it can.
[0082]
[Embodiment 3]
In the present embodiment, an ECT shift solenoid abnormal control process shown in FIG. 8 is executed instead of the ECT shift solenoid abnormal control process (FIG. 3). The other configuration is the same as that of the first embodiment.
[0083]
The ECT shift solenoid abnormal control process (FIG. 8) will be described. Note that the same processes as those in FIG. 3 are denoted by the same step numbers.
First, steps S102 to S108 are the same as those in FIG. 3, and a description thereof will be omitted. After the target gear is calculated in step S108, the entire range in which the target gear can be realized is calculated (S111a).
[0084]
Here, as shown in FIG. 6, when the first speed change solenoid valve S1 is abnormal and the second speed change solenoid valve S2 is normal, if the first speed is the target speed, the target speed is realized. Only one L range can be set. Therefore, in this case, only the L range is calculated. Similarly, if the second speed is the target shift speed, only the L range is calculated, and if the fourth speed is the target shift speed, only the D range is calculated. However, if the third speed is the target shift speed, two of D and two ranges are calculated.
[0085]
If the first speed solenoid valve S1 is normal but the second speed solenoid valve S2 is abnormal, and if the first speed is the target gear, the ranges in which the target gear can be realized are D, 2, L. There are three ranges. Therefore, in this case, these three are calculated. In the case of the second speed, since there is no corresponding range, a range that can be realized for the lower gear or the upper gear is calculated. In this case, if the first speed is used, the three ranges of D, 2, and L are calculated as described above. If the third speed is the target shift speed, only two ranges are calculated, and if the fourth speed is the target shift speed, only the D range is calculated.
[0086]
When both the first and second shift solenoid valves S1 and S2 are abnormal, if the first speed is the target shift speed, only the L range is calculated. In the case of the second speed, there is no corresponding range. Therefore, if the first speed one step below is used as described above, only the L range is calculated. If the third speed is the target shift speed, only two ranges are calculated, and if the fourth speed is the target shift speed, only the D range is calculated.
[0087]
When all the ranges that can achieve the target gear are calculated in this way, it is next determined whether or not the same range as the previous target range exists in all the ranges (S111b).
[0088]
If the same range exists ("YES" in S111b), the previous target range is set as the target range (S111c). For this reason, even if the target shift speed is changed, the same target range is maintained. For example, when the first shift solenoid valve S1 is abnormal and the second shift solenoid valve S2 is normal, the second speed solenoid valve S2 is turned off in the D range to realize the fourth speed. Consider shifting to the third speed. In this case, as shown in FIG. 6, there are two kinds of processing, that is, processing for changing to the two ranges and turning on the second speed-change solenoid valve S2, and processing for turning on the second speed-change solenoid valve S2 while keeping the D range. Exists. Of these, in the latter case, the range is the same as the previous target range, so the D range is set as the target range.
[0089]
If the same range does not exist ("NO" in S111b), one of the calculated ranges is selected and set as the target range, or, if there is only one calculated range, the range is set as the target range. It is set (S111d). When there are a plurality of calculated ranges, a smaller drive amount of the electric motor M for driving the rotary valve RV may be selected to move from the previous target range to the corresponding range.
[0090]
When the target range is set in step S111c or S111d, the target range is transmitted to the SBW-ECU 44 as a required range (S112). Then, the gear position setting process corresponding to the range (S114) is executed, and the present process is ended once.
[0091]
In the above-described configuration, the ECT shift solenoid abnormal control process (FIG. 8), the range-responsive shift stage setting process (FIG. 4), and the SBW shift solenoid abnormal control process (FIG. 5) are performed by the fault position switching means and the fault automatic switch. This corresponds to processing as a speed change means.
[0092]
According to the third embodiment described above, the following effects can be obtained.
(I). The effects (a) and (b) of the first embodiment are obtained.
(B). When changing the gear position, the target range is not changed as much as possible, so that the energy consumption by the electric motor M driving the rotary valve RV can be reduced.
[0093]
[Other embodiments]
(A). In each of the above embodiments, the automatic transmission having four forward speeds is used. However, the present invention can also be applied to a transmission having five forward speeds or any other number of speeds.
[0094]
Further, the gears that can be used when each gearshift solenoid is abnormal depend on the structure of the gearshift solenoid valve and the hydraulic control device in which the gearshift solenoid valve is incorporated, and in the case of four forward gears, the contents are not limited to those shown in FIG. Absent. However, in any of the configurations, when the shift solenoid is abnormal, the gear range limited by the failure can be increased by switching the range independently of the driver's operation, and a smooth limp home by automatic shifting can be achieved. Traveling is enabled, and the effects as described in the embodiments are obtained.
[0095]
(B). A shift map setting process corresponding to the abnormality of the shift solenoid in step S107 described in FIG. 7 may be added between step S106 and step S108 in FIG.
[0096]
(C). In each of the above embodiments, a lever type switch may be used instead of a button switch type range switching operation unit such as the range selection switch 46.
Although the range switching mechanism uses the rotary valve RV, an electromagnetic valve may be used.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating a schematic configuration of a transmission control device according to a first embodiment.
FIG. 2 is an explanatory diagram of the operation of each friction engagement portion and a shift solenoid valve for setting a shift speed in each range.
FIG. 3 is a flowchart of an ECT shift solenoid abnormality control process executed by the ECT-ECU according to the first embodiment;
FIG. 4 is a flowchart of a range-dependent gear position setting process also executed by the ECT-ECU.
FIG. 5 is a flowchart of an SBW shift solenoid abnormality control process executed by the SBW-ECU according to the first embodiment;
FIG. 6 is an explanatory diagram showing a relationship between a gear position established when a gearshift solenoid is abnormal and a gearshift solenoid valve operation.
FIG. 7 is a flowchart of an ECT shift solenoid abnormality control process executed by the ECT-ECU according to the second embodiment.
FIG. 8 is a flowchart of ECT shift solenoid abnormality control processing executed by the ECT-ECU according to the third embodiment.
[Explanation of symbols]
2 automatic transmission, 4 lock-up clutch, 6 torque converter, 8 second transmission section, 10 first transmission section, 12 carrier, 14 turbine runner, 16 sun gear, 18 housing, 20, 22 sun gear, 24 sun gear shaft, 26, 28 ring gear, 30 carrier, 32 ring gear, 34 output shaft, 36 carrier, 40 hydraulic control device, 42 ECT-ECU, 44 SBW-ECU, 46: Range selection switch, 47: Position sensor, M: Electric motor, RV: Rotary valve, S1: First shift solenoid valve, S2: Second shift solenoid valve, linear solenoid valve SLU.

Claims (5)

A shift control device for electrically shifting a position switching mechanism of a vehicular transmission in accordance with an operation state of a position switching operation unit, and executing a shift by driving a gear position switching mechanism corresponding to a corresponding position. ,
Speed change failure detecting means for detecting a failure of the speed change mechanism;
When a failure is detected by the gear change failure detecting means, the number of achievable gears is increased by executing position switching by the position switching mechanism independently of the position switching operation unit. Failure position switching means;
A shift control device comprising: 2. The shift control device according to claim 1, wherein the transmission is driven to shift by hydraulic pressure, and the position switching mechanism and the shift position switching mechanism are hydraulic switching valves. 3. The speed change mechanism according to claim 2, wherein the speed change mechanism is an electromagnetic valve, and the speed change failure detecting means determines that the current cannot be normally supplied to the speed change solenoid that drives the electromagnetic valve. A shift control device characterized by detecting that The shift control device according to any one of claims 1 to 3, further comprising an automatic shift unit at the time of failure that executes automatic shifting in accordance with the number of shift speeds achievable by the position switch unit at the time of failure. 5. The position switching device according to claim 4, wherein the position switching device at the time of failure executes the position switching by the position switching mechanism in accordance with a position required for realizing a required shift speed by the automatic transmission device at the time of failure. Transmission control device.

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