JPS6332449Y2 - - Google Patents

Description

[Detailed explanation of the idea]

(Industrial Application Field) The present invention relates to a failure diagnosis device for automatic transmissions, and more specifically, a failure diagnosis device for automatic transmissions that can detect when a failure in the output shaft rotation speed detection part of a torque converter has been recovered. It is related to. (Prior Art) Generally, as an automatic transmission, one configured by combining a torque converter and a multi-stage gear type transmission mechanism having a gear mechanism such as a planetary gear mechanism is widely used. For speed change control in such automatic transmissions, a hydraulic mechanism is usually adopted, and the hydraulic circuit is switched using an electromagnetic switching valve, thereby
Friction elements such as brakes and clutches, which are hydraulic actuators attached to the multi-gear transmission mechanism, are actuated as appropriate to switch the engine power transmission system to obtain a desired gear position. In order to switch the hydraulic circuit using the electromagnetic switching valve, an electronic control device detects that the vehicle's running state has exceeded a predetermined shift line, and a shift-up signal or a shift-down signal from this device is detected. Therefore, it is customary to selectively operate an electromagnetic switching valve, thereby switching the hydraulic circuit and changing speed. In such an automatic transmission, failures can occur in various parts, and one measure against this failure is disclosed in Japanese Patent Laid-Open No. 116957/1983. The system described in this publication uses the remaining normal gear shifting electromagnetic means to adopt a special gear for emergency use when it is detected that one of the multiple gear shifting electromagnetic means has failed. . By the way, a possible failure of the automatic transmission is a failure of the part that detects the rotational speed of the output shaft of the torque converter. The output shaft rotation speed of the torque converter is used, for example, as a parameter to determine the shift characteristics, or to determine whether or not the shift is in progress (whether or not the shift has been completed).
The torque converter is used for various types of control, but if the output shaft rotation speed detecting portion of the torque converter breaks down, a problem will occur in the control based on the output shaft rotation speed. Therefore, it is desirable to be able to detect whether or not the output shaft rotation speed detection part of the torque converter has failed as a prerequisite for performing emergency control in the event of a failure. become. However, there is a risk that the torque converter's output shaft rotation speed detection part may be mistakenly determined to be faulty due to noise etc. even though it is originally normal, and some kind of countermeasure is required to prevent this. . In particular, we do not only diagnose failure recovery, but also
Considering the case where emergency control is being performed due to a failure, it is desired that the change in vehicle behavior is small when transitioning from control at the time of failure to control after recovery from failure. (Purpose of the invention) The present invention was made in consideration of the above-mentioned circumstances, and is intended to recover from a failure in the rotation speed detection portion of a predetermined rotating element for determining the constant velocity characteristics of the output shaft of a torque converter, etc. In other words, this automatic transmission is designed so that it is possible to know that this detection part is operating normally, and to minimize changes in behavior when shifting to control after recovery from a failure. The purpose is to provide a fault diagnosis device for (Structure of the invention) In order to achieve the above-mentioned object, in the present invention, basically, the rotation speed of a predetermined rotating element for determining the speed change characteristic is set to a value other than that of other rotating elements other than this predetermined rotating element. When compared with the rotational speed of the engine drive system, if the rotational speed detection portion of the predetermined rotating element is a normal value, it is determined that the rotational speed detection portion of the predetermined rotating element is not malfunctioning but is normal. Specifically, pressure fluid is supplied to a torque converter connected to the engine output shaft, a gear type transmission mechanism connected to the output shaft of the torque converter, and a fluid type actuator that performs a speed change operation of the gear type transmission mechanism. an automatic transmission comprising: a shift electromagnetic means for controlling a gear shift; and a shift control means for outputting a shift up signal or a shift down signal to the shift electromagnetic means based on predetermined shift characteristics; As shown in Figure 1, there is a rotation speed detection means for detecting the rotation speed of a predetermined rotating element for determining the above-mentioned speed change characteristics, and a rotation speed detection means for detecting whether the output of the rotation speed detection means is abnormal or not, and when abnormal, a failure is detected. A failure detection means for outputting a signal; a failure control means for performing control when a failure is detected by the failure detection means; and a comparison rotation for detecting the rotation speed of an engine drive system other than the predetermined rotating element. a number detecting means, receiving the outputs of the rotation speed detection means and the comparison rotation speed detection means during control by the failure control means, and detecting the rotation speed of the other engine drive system when the rotation speed of the predetermined rotational element is not abnormal; A failure recovery detection means that outputs a failure recovery signal when the rotation speed is lower than a predetermined value; and a release means that releases the failure control by the failure control means when the failure recovery detection means detects failure recovery. There is a configuration in place. With such a configuration, if the rotation speed of the predetermined rotating element is zero, it can be determined that this detection part is not malfunctioning, but the failure recovery signal can be transmitted to other engine drive systems. Since the output is only made when the rotational speed of the motor is low, changes in behavior when transitioning from backup control, etc. in the event of a failure to normal control are suppressed as much as possible. (Example) Examples of the present invention will be described below based on the attached drawings, but first, an example of an automatic transmission to which the present invention is applied will be described. In Fig. 2, which shows the cross section of the mechanical part and the hydraulic control circuit of the electronically controlled automatic transmission, the automatic transmission
The AT includes a torque converter 10, a multi-stage gear transmission mechanism 20, and an overdrive planetary gear transmission mechanism 50 disposed between the torque converter 10 and the multi-stage gear transmission mechanism 20. The torque converter 10 includes a pump 11 coupled to an engine output shaft 1, a turbine 12 disposed opposite the pump 11, and a stator 13 disposed between the pump 11 and the turbine 12. A converter output shaft 14 is coupled to the converter output shaft 14 . Converter output shaft 14 and pump 1
A lock-up clutch 15 is disposed between the lock-up clutch 1 and the lock-up clutch 15. This lock-up clutch 15 is always urged in the engagement direction, that is, in the direction of locking up (directly connecting) the engine output shaft 1 and the torque converter output shaft 14, by hydraulic oil pressure circulating within the torque converter 10, and is also urged from the outside. It is maintained in the open state by supplied hydraulic pressure for opening. The multi-stage gear transmission mechanism 20 includes a front planetary gear mechanism 2
1 and a rear planetary gear mechanism 22, and a sun gear 23 of the front planetary gear mechanism 21 and a rear planetary gear mechanism 22.
It is connected to the sun gear 24 via a connecting shaft 25. The input shaft 26 of the multi-stage gear transmission mechanism 20 is
It is connected to the connecting shaft 25 via the front clutch 27 and to the internal gear 29 of the front planetary gear mechanism 21 via the rear clutch 28, respectively. Connecting shaft 25, that is, sun gear 2
A front brake 30 is provided between 3 and 24 and the transmission case. The planetary carrier 31 of the front planetary gear mechanism 21 and the rear planetary gear mechanism 22
The internal gear 33 is connected to the output shaft 34, and the rear brake 36 is connected between the planetary carrier 35 of the rear planetary gear mechanism 22 and the transmission case.
A one-way clutch 37 is provided. In the overdrive planetary gear transmission mechanism 50, the planetary carrier 52 that rotatably supports the planetary gear 51 is connected to the torque converter 1.
The sun gear 53 is coupled to an internal gear 55 via a coupling clutch 54. Overdrive brake 5 is installed between sun gear 53 and transmission case.
6 is provided, and the internal gear 55 is connected to the input shaft 26 of the multi-gear transmission mechanism 20. The multi-gear transmission mechanism 20 is of a conventionally known type and has three forward speeds and one reverse speed.
7, 28 and brakes 30, 36 as appropriate, a desired gear stage can be obtained. In the overdrive planetary gear transmission mechanism 50, the direct coupling clutch 54 engages and the brake 5
6 is released, coupling the shafts 14, 26 in direct coupling, while the brake 56 is engaged, coupling the shafts 14, 26 in overdrive when the clutch 54 is released. The automatic transmission AT described above includes a hydraulic control circuit CK as shown in FIG. This hydraulic control circuit CK has an oil pump 100 driven by an engine output shaft 1, and the pressure of hydraulic oil discharged from this oil pump 100 into a pressure line 101 is adjusted by a pressure regulating valve 102 and selected. It is guided to valve 103. Select valve 103
has shift positions 1, 2, D, N, R, P, and when the select valve 103 is in the 1, 2 and D positions, the pressure line 101 is connected to the select valve 10.
3 ports a, b, and c. Port a is connected to an actuator 104 for actuating the rear clutch 28, so that the rear clutch 28 is held engaged when the valve 103 is in the position described above.
Port a is also connected near the left end of the 1-2 shift valve 110, pushing its spool to the right in the figure. Port a is further connected to the right end of the 1-2 shift valve 110 via the first line L1 and to the 2-3 shift valve 12 via the second line L2.
The right end of the 3-4 shift valve 130 is connected to the right end of the 3-4 shift valve 130 via the third line L3. The first, second and third lines L1, L2,
First, second, and third drain lines DL1, DL2, and DL3 are branched from and L3, respectively, and these drain lines DL1, DL2,
For DL3, these drain lines DL1, DL2, DL
1st, 2nd, and 3rd solenoid valves that open and close 3
SL1, SL2, and SL3 are connected. When the solenoid valves SL1, SL2, and SL3 are demagnetized while the line 101 and port a are in communication, they close the respective drain lines DL1, DL2, and DL3, and as a result, the drain lines DL1, DL2, and DL3 are in the first, second, and third lines. pressure is increasing. Port b is also connected to second lock valve 105 via line 140, and this pressure acts to push the spool of second lock valve 105 downward in the figure. Second lock valve 105
When the spool of is in the down position, line 140
and line 141 are in communication with each other, and hydraulic pressure is introduced into the engagement side pressure chamber of the actuator 108 of the front brake 30 to hold the front brake 30 in the operating direction. Port c is connected to second lock valve 105, and this pressure acts to push the spool of valve 105 upward. Further, port c is connected to a 2-3 shift valve 120 via a pressure line 106. This line 106 is connected when the solenoid valve SL2 of the second drain line DL2 is demagnetized.
When the pressure in the second line L2 is increased and this pressure moves the spool of the 2-3 shift valve 120 to the left, it communicates with the line 107. The line 107 is connected to the release side pressure chamber of the actuator 108 of the front brake 30, and when hydraulic pressure is introduced into the pressure chamber, the actuator 108 moves the brake 30 in the release direction against the pressure of the engagement side pressure chamber. Activate. Pressure in line 107 is also directed to actuator 109 of forward clutch 27, causing it to engage. The select valve 103 has a port d leading to the pressure line 101 in one position, and this port d
reaches the 1-2 shift valve 110 via line 112, and further via line 113 to the rear brake 3.
6 actuator 114. 1-2
The shift valve 110 and the 2-3 shift valve 120 are
When the solenoid valves SL1 and SL2 are demagnetized by a predetermined signal, the spool is moved to switch the lines, thereby operating the predetermined brake or clutch, and performing 1-2 and 2-3 speed change operations, respectively. . In addition, the hydraulic control circuit CK includes a cutback valve 115 that stabilizes the hydraulic pressure from the pressure regulating valve 102, and a pressure regulating valve 115 that stabilizes the hydraulic pressure from the pressure regulating valve 102.
A vacuum throttle valve 116 for changing the line pressure from 2 and a throttle backup valve 117 for assisting the throttle valve 116 are provided. Furthermore, the hydraulic control circuit CK of this example includes a clutch 5 of a planetary gear transmission mechanism 50 for overdrive.
4 and brake 56, 3-4
A shift valve 130 and an actuator 132 are provided. The engagement side pressure chamber of the actuator 132 is connected to the pressure line 101, and the pressure of the line 101 pushes the brake 56 in the engagement direction. This 3-4 shift valve is also
- Similar to the 2 and 2-3 shift valves 110 and 120, when the solenoid valve SL3 is demagnetized, the spool 131 of the 3-4 shift valve 130 moves downward, the pressure line 101 and the line 122 are cut off, and the line 122 is drained. This eliminates the hydraulic pressure acting on the release side pressure chamber of the actuator 132 of the brake 56, causing the brake 56 to operate in the engaging direction and the actuator 134 of the clutch 54 acting to release the clutch 54. Furthermore, the hydraulic control circuit CK of this example is provided with a lock-up control valve 133, which is communicated with port a of the select valve 103 via a line L4. From this line L4, drain lines DL1, DL2,
A drain line DL4, which is provided with a solenoid valve SL4 similar to DL3, branches off. The lock-up control valve 133 is configured so that when the solenoid valve SL4 is energized to close the drain line DL4 and the pressure in the line L4 increases, this spool is connected to the line 12.
3 and the line 124, the line 124 is drained and the lock-up clutch 15 is moved in the operating direction. In the above configuration, the operational relationship between each gear, the lockup, and each solenoid, and the operational relationship between each gear and the clutch and brake are shown in Table 1.
It is shown in Table 3.

【table】

【table】

[Table] FIG. 3 shows a control device for an automatic transmission AT according to the present invention, which controls the hydraulic control circuit CK associated with the above-mentioned automatic transmission AT to perform speed change control and lock-up control. An example is shown together with an engine EN incorporating the automatic transmission AT. In this FIG. 3, the control unit 200 is
As shown in FIG. 12, a lock-up control circuit 201 performs lock-up control on the automatic transmission AT, and a shift control circuit 20 performs shift control.
2, and also includes a failure detection circuit A and a failure recovery detection circuit B. This control unit 200 includes signals from the turbine rotation speed sensor TS, engine output shaft rotation speed sensor ES, and transmission output shaft rotation speed sensor AS.
A signal is input from an engine load sensor LS that detects the throttle opening TH of a throttle valve 204 provided in the intake passage 203 of the engine EN. Note that here, the turbine rotation speed TSP is treated as information corresponding to the vehicle speed, and the throttle opening TH is treated as information corresponding to the engine load. The failure detection circuit A and the failure recovery detection circuit B are for determining whether the part related to the turbine rotation speed sensor TS has failed or whether this failure has been recovered.
When this sensor TS related part is in failure, it outputs a failure signal SP, and when the failure has been recovered, it outputs a failure recovery signal SP', as will be described later. The speed change control circuit 202 of the control unit 200 is
Information obtained from the turbine rotation speed signal from the turbine rotation speed sensor TS mentioned above, the throttle opening signal from the engine load sensor LS, and the driving mode sensor (not shown) that detects the driving mode,
For example, a calculation is made as to whether or not a shift should be made by comparing the shift up shift line and the down shift shift line of the shift map, which are predetermined based on the turbine rotational speed-engine load characteristic shown in FIG. 4, for example. Then, according to this calculation result, the shift up signal Cp or the shift down signal Cp' is applied to the first, second, and third solenoid valves SL of the hydraulic control circuit CK.
1, SL2, and SL3, and selectively excite them in the manner shown in Table 1 to change the gear position of the automatic transmission AT to an upper gear (upshift) or a lower gear (downshift). Control is performed to cause the transition to . In addition, in the lockup control circuit 201 of the control unit 200, as in the case of the above-mentioned shift control circuit 202, the turbine rotation speed signal from the turbine rotation speed sensor TS, the engine load sensor
The information transmitted by the throttle opening signal and driving mode signal from the LS is applied to the lock-up operation line and lock-up release line of the shift map, which is predetermined based on the turbine speed-engine load characteristics as shown in Fig. 4, for example. It compares the data and calculates whether it should be locked up or released. Then, depending on the result of this calculation,
A lockup activation signal Cq or a lockup release signal Cq' is output to the fourth solenoid valve SL4 of the hydraulic control circuit CK. The control unit 200 can be configured by, for example, a microcomputer, and the operation program of the microcomputer that configures the control unit 200 is illustrated in FIGS. 5 to 11, for example.
The process is executed according to the flowchart shown in the figure. This flowchart will be explained in sequence below. Overall Control FIG. 5 shows an overall flowchart of shift control. As can be seen from this figure, shift control is first performed from initialization settings in step S1. This initialization setting initializes the ports and necessary counters of each control valve that switches the hydraulic control circuit of the automatic transmission, sets the gear transmission mechanism 20 to first speed, and locks up the lock-up clutch 1.
Set 5 to release. After this, various working areas of the control unit 200 are initialized and completed. Next, in step S2, the position of the select valve 103, that is, the shift range is read. Then, in step S3, it is determined whether the read shift range is the "1 range". When the shift range is "1 range", the lock-up is released in step S4, and then in step S5 it is calculated whether or not the engine will overrun by downshifting to the first speed. When it is determined in step S6 that an overrun occurs, the shift valve is controlled to shift the gear transmission mechanism 20 to the second speed in step S7. When it is determined that there is no overrun, step S is executed to prevent a shift shock.
8 to shift to 1st gear. If the shift range is not "1 range" in step S3, it is determined in step S9 whether the shift range is "2 range". When the shift range is the "2" range, lockup is released in step S10, and then the gear is shifted to second speed in step S11. On the other hand, if it is determined in step S9 that the shift range is not the "2 range", this indicates that the shift range is in the D range after all. The shift down control at step S14 and the lock up control at step S14 are performed in sequence. As described above, steps S7, S8, S1
1. When S14 is completed, return to step S2,
The routine described above is repeated. Shift-up Control Next, the shift-up control (step S12 in FIG. 5) will be explained in detail with reference to FIG. 6. First, the gear position, that is, the gear transmission mechanism 20
This is done by reading the position of . Next, based on the read gear position, it is determined in step S21 whether or not the vehicle is currently in the fourth gear. If the gear is not in fourth gear, the current throttle opening TH' is read out in step S22, and the current throttle opening TH' is read out in step S22.
At step 23, data TSP ₁ of the shift up map corresponding to the throttle opening is read out. An example of this shift map is shown in FIG. Next, in step S24, the current turbine rotation speed TSP' is read out, and this current turbine rotation speed TSP' is compared with the data TSP ₁ of the shift-up map read above, and in step S25, the current turbine rotation speed TSP' is It is determined whether or not the turbine rotation speed TSP ₁ is larger than the set turbine rotation speed TSP 1 indicated by the shift line Mfu ₁ in relation to the opening degree. The current turbine rotation speed TSP′ is the above-mentioned set turbine rotation speed in relation to the throttle opening TH.
When TSP is greater than ₁ , flag 1 for one-stage shift up is read out in step S26, and it is determined whether the read flag 1 is 0 or 1, that is, whether it is in a reset state or a set state. Flag 1 is changed from 0 to 1 when a 1st gear shift up is executed. When flag 1, which stores the 1st gear shift up state, is in the reset state, flag 1 is set to 1 in step S27, and then step S27 is changed. A shift up is performed in S87, and the one-stage shift up control is completed. In step S26, if the determination as to whether flag 1 in the one-stage shift-up control system is 1 is 1, the control is completed. Furthermore, even if the determination at the initial stage as to whether the vehicle is in the fourth gear is the fourth gear, the control is completed as is. Furthermore, in step S25, the current turbine rotation speed is
The set turbine rotation speed indicated by the shift line Mfu ₁ in the relationship between TSP′ and throttle opening TH
If it is determined that TSP ₁ is not greater than 1, then in step S29 TSP ₁ is multiplied by, for example, 0.8 to set a new set turbine rotation speed TSP ₂ on the new shift line Mfu ₂ shown by the broken line in FIG. do. Next, in step S30, the current turbine rotation speed TSP' is changed to the set turbine rotation speed TSP ₂ indicated in the above-mentioned speed change number Mfu ₂ .
If TSP2 is larger than TSP', flag ₁ is reset in step S31 to prepare for the next cycle, and vice versa.
If TSP ₂ is not larger than TSP', then shift down control is performed. Shift down control Shift down control (step S13 in Figure 5)
is executed according to the downshift control subroutine shown in FIG. This downshift control is performed by first reading out the gear position, as in the case of upshift control. Next, based on this read gear position,
In step S41, it is determined whether the vehicle is currently in the first gear. If it is not the first speed, step S42
After reading out the throttle opening TH in step S43, data _TSP1 of the shift down map corresponding to the read throttle opening TH is read out. An example of this shift down map is shown in FIG. Next, in step S44, the current turbine rotation speed is
Read out TSP′ and calculate this turbine rotation speed TSP′ as
In light of the set turbine speed TSP ₁ , which is the data of the shift-down map read above, the current turbine speed TSP' is determined to be the set turbine speed TSP ₁ shown on the shift-up shift line Mfd ₁ in relation to the throttle opening TH. It is determined in step S45 whether or not it is smaller. When the current turbine rotation speed TSP' is smaller than the set turbine rotation speed TSP ₁ , step S
At step 46, flag 2 for downshifting by one stage is read out. Flag 2 is changed from 0 to 1 when the gear is downshifted by one gear. Next, it is determined whether this flag 2 is 0 or 1, that is, whether it is in the reset state or the set state. When flag 2 is in the reset state, flag 2 is set to 1 in step S47, and then flag 2 is set to 1 in step S48.
1-stage downshift is performed, and the 1-stage downshift control is completed. If it is determined in step S46 that flag 2 is in the set state, downshifting is not possible, and the control is then completed. Further, in step S45, if it is determined that the current turbine rotation speed TSP' is not smaller than the set turbine rotation speed TSP ₁ indicated by the first-stage downshift shift line Mfd ₁ , a shift is made according to the current throttle opening. The down map is read out, and in step S49, the set turbine speed TSP ₁ shown on the shift line Mfd ₁ of this map is multiplied by 1/0.8, for example, to obtain the new set turbine speed on the new shift line Mfd ₂ .
Configure TSP ₂ . Next, in step S50, if the current turbine rotational speed TSP' is smaller than the set turbine rotational speed _TSP2 shown in the shift line _Mfd2 , the control is completed, and if it is not smaller, flag 2 is reset in step S51. The control is completed by setting it to 0, and then transitioning to lockup control. In addition, in the shift-up speed change control and shift-down speed change control explained above, if no speed change is performed, the shift line on the map will have a value of 0.8 or 1/0.8.
The purpose of creating hysteresis by multiplying by be. Lockup Control Next, lockup control will be explained with reference to FIG. 10 (step S14 in FIG. 5). First, in the lock-up control, after reading the current throttle opening TH' in step S61, in step S62, the lock-up OFF map, that is, the shift line Moff( (See Figure 11)
Read out the set turbine rotation speed TSP ₁ corresponding to the throttle opening from the map shown. Then,
In step S63, the current turbine rotation speed is
TSP' is read, and in step S64, this read current turbine rotation speed TSP' is compared with the lockup OFF map, and this current turbine rotation speed TSP' is the set turbine rotation speed TSP indicated on the shift line MOFF. It is determined whether it is greater than ₁ .
If the current turbine rotation speed TSP' is smaller than the set turbine rotation speed TSP ₁ , step S65
The lockup is canceled and the process ends. On the other hand, if the current turbine rotation speed TSP' is larger than the set turbine rotation speed TSP ₁ , in step S66, a lock-up ON map is created, that is, a shift line used for control to turn the lock-up into an ON (operating) state. Mon (see Fig. 11), another set turbine rotation speed TSP ₂ corresponding to the throttle opening TH is read out, and then in step S67, the current turbine rotation speed is
It is determined whether TSP' is larger than the set turbine rotation speed _TSP2 . If TSP ₂ is larger than TSP', lockup is activated in step S68 and the process ends, whereas if TSP ₂ is not larger than TSP', the process ends. Next, we will explain the failure detection circuit A and the failure recovery detection circuit B. First, we will explain the turbine rotation speed.
A failure detection circuit A for diagnosing a failure in the TSP detection portion will be explained with reference to FIG. First, the signal from the turbine rotation speed sensor TS is
After being input to the torque converter output shaft rotation speed detection circuit 221 and converted into a predetermined electrical signal, the torque converter output shaft rotation speed calculation circuit 22
2, the rotation speed of the output shaft 14 in the torque converter 10, that is, the turbine rotation speed TSP is calculated. Signal St corresponding to this turbine rotation speed TSP
is outputted to the shift control circuit 202 and the lockup control circuit 201, and used for the shift control and lockup control as described above. Further, this turbine rotation speed signal St is input to the first comparator 223. This first comparator 223 receives a signal from the first reference circuit 224, that is, the turbine rotation speed.
A signal corresponding to TSP is zero is input,
When the turbine rotation speed signal St from the rotation speed calculation circuit 222 is larger than the zero signal from the first reference circuit 224, a high signal is output from the first comparator 223, and this high signal is sent to the inverter 225. The signal is inputted to the AND circuit 226 via. On the other hand, the output from the sensor ES (see also Fig. 3) that detects the rotation speed of the engine output shaft 1 passes through the engine output shaft rotation speed detection circuit 227, the engine output shaft rotation speed calculation circuit 228, and the engine rotation speed
It is input to the second comparator 229 as an engine output rotational speed signal Et corresponding to ESP. This engine rotational speed signal Et is the rotational speed of the output shaft of the torque converter 10, that is, the rotational speed of the engine drive system other than the turbine rotational speed TSP. A signal from the second reference circuit 230 is also input to the second comparator 229, and the second comparator 229
The signal from the reference circuit 230 corresponds to the stall rotation speed of the torque converter 10 (generally 2000 to 3000 rpm).
The signal corresponds to a stall-compatible rotation speed that is slightly larger than the one set between Then, when the engine speed signal Et is larger than the stall corresponding speed signal, the second comparator 22
9 outputs a high signal, and this high signal is input to the OR circuit 231. Furthermore, in the embodiment, as the rotation speed of the engine drive system other than the turbine rotation speed TSP, the transmission 2
Therefore, the output from the sensor AS (also see FIG. 3) that detects the rotation speed of the output shaft 34 of the transmission 20 is detected by the transmission. Output shaft rotation speed detection circuit 232,
Via the transmission output shaft rotation speed calculating circuit 233, it is inputted to a third comparator 234 as a transmission output shaft rotation speed signal At corresponding to the transmission output shaft rotation speed ASP. This third comparator 234 is
A signal from the third reference circuit 235 is inputted, and the signal from the third reference circuit 235 is set as a rotation speed signal corresponding to a predetermined vehicle speed (for example, 40 km/h). Note that the rotation speed signal (vehicle speed) set in this third reference circuit 235
is set as small as possible to correspond to a vehicle speed that is not dangerous even when the turbine rotation speed is left at zero and the output is left as is due to a failure and a downshift is performed. The third comparator 234 then outputs the transmission output shaft rotation speed signal At
is larger than the set rotation speed signal from the third reference circuit 235, a high signal is sent to the OR circuit 231.
It is now output to . The OR circuit 231 connects the second and third comparators 22
When a high signal is input from either one of 9 and 234, a high signal is output to the AND circuit 226, and this AND circuit 226 outputs a high signal to the AND circuit 226 when a high signal is input from both. A flip-flop (hereinafter simply referred to as FF) 236 that resets the high signal as the failure signal Sp
It is designed to output to the set terminal S of the. When this FF 236 receives a high signal at its set terminal S, it outputs a high signal to the prohibition circuit 237, and upon receiving this high signal, the prohibition circuit 237 controls both control circuits 202 and 201. Outputs prohibition signal X to stop. Also, this FF23
When a high signal is input to the reset terminal R of FF 236, a low signal is output from the FF 236 to the inhibition circuit 237, and the inhibition circuit 237 that receives this low signal outputs the control to both control circuits 202 and 201. Ban release signal to reinstate
X′ is output. Note that when the control functions of both control circuits 202 and 201 are stopped, the transmission 20 may remain fixed at a certain gear, or other parameters other than the turbine rotation speed TSP (for example, the transmission output shaft This means performing an emergency gear shift using the rotational speed (ASP). To explain the operation of the failure detection circuit A, first, if the running turbine rotation speed TSP is normally detected, a high signal is output from the first comparator 223, and this high signal is transmitted to the inverter 225. After being made into a low signal by , it is input to the AND circuit 226 . Therefore, in this case, the failure signal SP is not output from the AND circuit 226 to the prohibition circuit 236, and both control circuits 20
2, 201 performs normal functions. Now, for some reason, the turbine rotation speed is being output from the running rotation speed calculation circuit 222 to the first comparator 223.
When the rotational speed signal St indicating that TSP is zero is input, a low signal is output from the first comparator 223, and a high signal is eventually input to the AND circuit 226. In this state, engine speed
When ESP is larger than the stall-compatible rotation speed of the torque converter 10 or larger than a predetermined vehicle speed, a high signal is output from the comparator 229 or 234, and a high signal is sent from the OR circuit 231 to the AND circuit 226. Output. As a result, a high signal as a failure signal SP is outputted from the AND circuit 226 to the prohibition circuit 236, and the functions of both control circuits 202 and 201 are stopped. In this way, the turbine speed TSP
It is diagnosed that the is not being detected properly, but
The comparison results from the second or third comparators 234, 234 are used because when the vehicle is stopped, the turbine speed TSP may be normal even if it is zero. If it is zero, this is to determine whether or not the operating state is abnormal. Therefore, this second and third comparator 23
4,234 may be provided, and as for the rotational speed of the engine drive system other than the output shaft of the torque converter 10, other than the engine output shaft 1 and the transmission output shaft 34 may be provided. It is possible to check the rotational speed of an appropriate part, such as the rotational speed of a driving wheel. Next, the failure recovery detection circuit B for diagnosing whether or not the failure in the sensor TS-related portion has been recovered will be explained with reference to FIG. 12 again. This failure recovery detection circuit B includes three comparators 24, fourth to sixth.
1,244,248, fourth to sixth reference circuits 242, 245, 248, and one AND circuit 243 and one OR circuit 247. Since such a failure recovery detection circuit B has a correspondence relationship with the configuration of the failure detection circuit A described above, first, the components having a correspondence relationship with each other will be explained using their codes. 223, 241, 224, and
2,229 and 244, 230 and 245, 234 and 248, 235 and 249, 226 and 243, 23
1 and 247 correspond to each other, and have the same function as explained in connection with the failure detection circuit A mentioned above. Regarding the failure recovery detection circuit B, the differences from the failure detection circuit A will be explained with emphasis. First, the fourth comparator 241 is connected to the torque converter 10.
When the output shaft rotational speed signal St is greater than zero, a high signal is output to the AND circuit 243. Also, the fifth
The comparator 244 outputs a rotational speed signal of the engine output shaft 1.
When Et is larger than the above-described stall-compatible rotation speed, a high signal is output, and this high signal is turned into a low signal by an inverter 246 and input to an OR circuit 247. Furthermore, the sixth comparator 248 determines that the rotation speed signal AS of the transmission output shaft 34 is a predetermined value (for example, 40 km/h).
h), a high signal is output, and this high signal is turned into a low signal by the inverter 250 and input to the OR circuit 247. Therefore, the OR circuit 247 connects the fifth and sixth comparators 244 and 24
When a low signal is output from either one of 8, a high signal is output to the AND circuit 243. As is clear from the above explanation, when the rotational speed of the output shaft 14 of the torque converter 10 is not zero and the engine rotational speed is below the stall-compatible rotational speed or the vehicle speed is below 40 km/h, the AND circuit 243 to 5 A high signal as the failure recovery signal SP' is output, and this high signal is input to the reset terminal R of the FF 236. As a result, the prohibition release signal X' is output from the prohibition circuit 237 to both control circuits 202 and 201, and
2, 201 performs the shift control or lock-up control during normal conditions as described above. In addition, in FIG. 12, in order to make it easier to understand the failure detection circuit A and the failure recovery detection circuit B, the first to third
Apart from the comparators 223, 229, 234 and the first to third reference circuits 224, 230, 235, the fourth
- The case where the sixth comparators 241, 244, 248 and the fourth to sixth reference circuits 242, 245, 249 are provided has been described, but the fourth to sixth comparators or reference circuits are It is also possible to use the third comparator and the reference circuit. Of course, the rotation speed of other engine drive systems other than the output shaft 14 of the torque converter 10 can be the rotation speed of appropriate parts such as the drive wheels, and the engine output shaft rotation speed or the transmission output shaft rotation speed It is also possible to view only one of them. Although the embodiments have been described above, when the electronic control circuit 200 is configured by a microcomputer, it can be configured by either a digital type or an analog type. (Effects of the invention) As is clear from the above description, the present invention is such that the part that detects the rotational speed of a predetermined rotating element for determining the shifting characteristics is incorrectly determined to be malfunctioning due to noise etc. Even in such a case, it is possible to know that the failure of this detection part has been recovered. As a result, it is possible to perform the original control again from the backup control performed when the rotation speed detection part of the predetermined rotational element is out of order. Further, since the failure recovery signal is output only when the rotational speed of the engine drive system other than the predetermined rotating element is smaller than a predetermined value,
For example, changes in behavior when transitioning from the above-mentioned backup control to the original control can be minimized, which is preferable from the standpoint of safety and shock prevention.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram of the present invention. FIG. 2 is a diagram showing a cross section of the mechanical part of the automatic transmission and its hydraulic circuit. FIG. 3 is an overall system diagram showing one embodiment of the present invention. FIG. 4 is a diagram showing an example of a speed change diagram. Figure 5,
FIG. 6, FIG. 8, and FIG. 10 are flowcharts showing an example of control contents of the present invention. FIG. 7 is a diagram showing an example of a shift up map. FIG. 9 is a diagram showing an example of a shift down map. FIG. 11 is a diagram showing an example of a lockup map. FIG. 12 is a circuit diagram for performing failure diagnosis and failure recovery diagnosis of the output shaft rotation speed detection portion of the torque converter. 1: Engine output shaft, 10: Torque converter output shaft, 14: Torque converter output shaft, 20:
Multi-stage gear transmission mechanism, 200: Control unit, 20
2: Speed change control circuit, A: Failure detection circuit, B: Failure recovery detection circuit, EN: Engine, ESP: Engine rotation speed, TSP: Turbine rotation speed, ASP: Transmission output shaft rotation speed, TS: Turbine rotation speed sensor ,
ES: Engine speed sensor, AS: Transmission speed sensor.

Claims (1)

[Claims for Utility Model Registration] Pressure on a torque converter connected to the engine output shaft, a gear type transmission mechanism connected to the output shaft of the torque converter, and a fluid actuator that performs a speed change operation of the gear type transmission mechanism. An automatic transmission comprising a speed change electromagnetic means for controlling fluid supply, and a speed change control means for outputting a shift up signal or a shift down signal to the speed change electromagnetic means based on predetermined speed change characteristics. A rotation speed detection means for detecting the rotation speed of a predetermined rotational element for determining the speed change characteristics, and a failure for detecting whether or not the output of the rotation speed detection means is abnormal and outputting a failure signal when abnormality occurs. a detection means; a failure control means that performs control when a failure is detected by the failure detection means; a comparative rotation speed detection means that detects the rotation speed of an engine drive system other than the predetermined rotational element; During the control by the failure control means, the rotation speed of the other engine drive system is determined by receiving the outputs of the rotation speed detection means and the comparison rotation speed detection means, when the rotation speed of the predetermined rotating element is not abnormal. A failure recovery detection means for outputting a failure recovery signal when the failure recovery signal is smaller than the value, and a canceling means for canceling the failure control by the failure control means when the failure recovery detection means detects the failure recovery. A fault diagnosis device for automatic transmissions featuring: