JPH0210303B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention is directed to turning on and off a plurality of electromagnetic means for speed change.
In an automatic transmission that controls the supply of hydraulic pressure to a hydraulic actuator of a gear-type transmission mechanism to switch its power transmission, that is, to change speeds, when some of the electromagnetic means for speed-changing break down. The present invention also relates to a fault diagnosis device for an automatic transmission that performs emergency (auxiliary) speed change control using the remaining normally operating electromagnetic means for speed change. (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. By the way, in such an electromagnetic means for speed change, if a failure occurs in the electromagnetic means for speed change, desired speed change control cannot be performed. For this reason, as shown in Japanese Patent Application Laid-Open No. 57-116957, two electromagnetic means for speed change are usually used to perform multi-stage speed change control by the combination of ON and OFF. If one of the transmission electromagnetic means fails, only the remaining normal transmission electromagnetic means is used to fix the gear to the gear that is closest to the gear before the failure (the gear ratio is close), and at least the vehicle is no longer possible to drive. Some methods have been proposed to avoid such situations. However, the method described in the above publication has the following problems. That is, since there is only one emergency gear in the event of a failure of the electromagnetic means for shifting, this will cause considerable problems in driving. In addition, in the case described in the above-mentioned publication, only the failure of the electromagnetic means for speed change itself is considered as a failure of the electromagnetic means for speed change, and the failure occurs when this electromagnetic means for speed change is in the ON (short) or OFF (broken wire) state. However, considering the possibility of failure (broken wire or short) of the power supply transistor that controls the power supply to the electromagnetic means for speed change, it is assumed that the electromagnetic means for speed change is in the ON state. It is virtually impossible to determine whether a failure occurs in the OFF state. For this reason, it has become impossible to select the manner in which the remaining normal transmission electromagnetic means should be operated, and it has also become impossible to select a desired emergency gear. In other words, whether or not the electromagnetic means for speed change is malfunctioning can be determined by the "high" or "low" voltage between the base of the power supply transistor and the output terminal of the collector or emitter.
This is generally done by looking at relationships. When there is always a "high" and "low" potential difference between this base and the output terminal, this power supply transistor and the electromagnetic means for speed change are normal, and the voltage between the base and the output terminal is normal. When there is no difference between "high" and "high" or "low" and "low", it is determined that the power supply transistor or the speed changing electromagnetic means has failed. The manner in which this failure is determined is, for example, if the power supply transistor is normal and the gear shifting electromagnetic means is disconnected, and this is expressed as a signal state of "high" and "high" (in this case, the gear shifting electromagnetic means is disconnected). teeth
OFF), these signal states of "high" and "high" also appear when the electromagnetic means for speed change is normal and the power supply transistor is shorted; in this case, the same "high" and "high" signals are displayed. Even if it is, the electromagnetic means for speed change is turned on. (Object of the Invention) The present invention has been made in consideration of the above circumstances, and when one of the plurality of speed change electromagnetic means fails, the failure of this speed change electromagnetic means is turned ON.
It is an object of the present invention to provide a fault diagnosis device for an automatic transmission that is capable of performing auxiliary shift control using a plurality of gears for emergency use, regardless of whether the automatic transmission is in the OFF state or in the OFF state. (Structure of the Invention) The present invention basically provides at least three gear-shift electromagnetic means for controlling the hydraulic pressure supply to the hydraulic actuator of the gear-type transmission mechanism, and turns ON and OFF by the gear-shift electromagnetic means. The hydraulic pressure supply mode to the above-mentioned actuator is provided with a greater degree of freedom in combination. In other words, even if one of the transmission electromagnetic means drive systems including the transmission electromagnetic means breaks down, at least two remaining normally operating electromagnetic means can be used to turn them on and off.
By this combination, auxiliary shift control is performed at a plurality of gears, although the number of gears is fewer than in normal conditions. Specifically, as shown in FIG. 1, at least three devices control the supply of pressure fluid to a gear-type transmission mechanism interposed in the engine drive system and a fluid-type actuator that performs a speed change operation of the gear-type transmission mechanism. Based on individual speed change electromagnetic means and predetermined main speed change characteristics,
main shift control means that outputs a shift up signal or a shift down signal to each of the shift electromagnetic means to perform shift control between a plurality of gear stages; a failure detection means that detects a failure of the shift electromagnetic means; Prohibition means receives an output from the failure detection means and prohibits control by the main speed change control means when the speed change electromagnetic means fails; When a failure occurs, the failed electromagnetic means for speed change is removed from the target of speed change operation, and the remaining normally operating electromagnetic means are used to create a plurality of gears that function normally regardless of the failure state of the failed electromagnetic means for speed change. and auxiliary shift control means for controlling the shift at the gear position. (Example) Examples of the present invention will be described below based on the attached drawings. 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 . A lock-up clutch 15 is disposed between the converter output shaft 14 and the pump 11. This lockup clutch 15 is
The hydraulic pressure circulating within the torque converter 10 constantly urges the engagement direction, that is, the direction of locking up (directly connecting) the engine output shaft 1 and the torque converter output shaft 14, and the opening hydraulic pressure supplied from the outside It is designed to be held open. The multi-stage gear transmission mechanism 20 includes a front planetary gear mechanism 2
1 and a multi-stage planetary gear mechanism 22, the sun gear 23 of the front-stage planetary gear mechanism 21 and the rear-stage 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 direct 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 a direct connection, 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, which 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. As a result, the hydraulic pressure acting on the release side pressure chamber of the actuator 132 of the brake 56 is eliminated, causing the brake 56 to rotate in the engagement 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. When the solenoid valve SL4 is energized and the drain line DL4 is closed, and the pressure in the line L4 increases, the lockup control valve 133 controls the spool from 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 an automatic transmission according to the present invention that controls the hydraulic control circuit CK associated with the above-mentioned automatic transmission AT to perform main and auxiliary shift control and lock-up control. An example of an AT control device is the engine EN in which the automatic transmission AT is installed.
Shown with In this FIG. 3, the control unit 200 is
As before, the first to third solenoids SL1 to SL3 and the fourth solenoid SL serve as electromagnetic means for speed change.
In addition to each drive function (circuit) that drives
In addition to having a main shift control function that performs shift control when the drive system is normal, each solenoid SL1~
A failure detection function detects a failure in each solenoid drive system including SL3, and if one of the solenoid drive systems fails, the main shift control function is stopped and the two remaining normal solenoid drive systems are used. It has an auxiliary shift control function for controlling the shift. Such a control unit 200 includes a throttle opening signal from a throttle sensor LS that detects the throttle opening TH, and a turbine rotation speed from a turbine sensor TS that detects the turbine rotation, that is, the output shaft rotation speed TSP of the torque converter 10. A vehicle speed signal from a vehicle speed sensor AS that detects the output shaft rotation speed of the gear type transmission mechanism 20, that is, the vehicle speed VSP is inputted. A control unit 20 that performs the control as described above.
0 can be configured by, for example, a microcomputer, and the operation program of the microcomputer constituting the control unit 200 is executed according to the flowcharts shown in FIGS. 5 to 12, for example. . 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 at step S0. 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 S1, the electromagnetic manual drive system for speed change, that is, each solenoid SL1 to SL3
It is determined whether or not a failure has occurred in the solenoid drive circuit, and if any one of the solenoid drive systems is determined to be in failure, the lockup is released in step S15, and auxiliary shift control is performed in step S16. . Also, if it is determined in step S1 that there is no failure, the process moves to step S2.
Normal control, that is, main shift control and lock-up control will be performed. Step S1 above
If it is determined that there is no malfunction, the step
Shifting to S2, normal control, that is, main shift control and lock-up control is performed. The failure determination and auxiliary shift control in step S1 described above will be described in detail later, but the steps from step S2 onwards, which are control during normal operation, will be explained first. Control during normal operation, that is, main shift control and lock-up control, is performed based on predetermined main shift characteristics and lock-up characteristics as shown in FIG. The process starts by reading the position of the select valve 103, that is, the shift range.
Then, in step S3, it is determined whether the read shift range is the "1 range". When the shift range is "1 range", the lockup 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. If it is determined that there will be no overrun, the gear is shifted to the first gear in step S8 to prevent a shift shock. 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 “2 range”, the step
Lock-up is released in step S10, and then the gear is shifted to second speed in step S11. Meanwhile, step S9
If it is determined that the shift range is not "2 range", it means that the shift range is in the D range after all, and in this case, the shift up control in step S12 and the shift down control in step S13, which will be described later, are performed , and lockup control in step S14 are performed in order. As described above, steps S7, S8, S11,
When S14 is completed, the process returns to step S2 and the above-described routine is repeated. Shift-up Control Next, the shift-up control (normal 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 it is not the fourth speed, the current throttle opening TH' is read out in step S22, and data _TSP1 of the shift up map corresponding to the throttle opening degree is read out in step S23. 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 0 when a 1-stage shift up is executed.
When flag 1, which is changed from 1 to 1 and stores the 1st gear shift up state, is in the reset state, flag 1 is set to 1 in step S27, and then a shift up is performed in step S87, and 1st gear shift up control is performed. complete. In the above step S26, it is determined whether flag 1 in the 1st gear shift up control system is 1 or not.
If so, the control is completed as is. 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 0.8, for example, 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, it is determined whether or not the current turbine rotation speed TSP' is larger than the set turbine rotation speed TSP ₂ indicated by the above-mentioned speed change number Mfu _2. If TSP ₂ is larger than TSP', step S30 is performed. Reset flag 1 in S31 to prepare for the next cycle, and conversely from TSP'
If TSP ₂ is not larger, the shift is then shifted to the downshift means. 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,
Next, in step S41, it is determined whether or not the gear is currently in the first gear. If the gear is not in 1st gear, the throttle opening TH is read out in step S42, and then
In S43, data TSP ₁ of the shift down map corresponding to the read throttle opening TH is read.
An example of this shift down map is shown in FIG. Next, in step S44, the current turbine rotation speed TSP' is read out, and this turbine rotation speed TSP' is compared with the set turbine rotation speed TSP ₁ , which is the data of the shift down map read above, to determine the current turbine rotation speed TSP'. The step determines whether or not the set turbine rotation speed TSP ₁ is smaller than the set turbine rotation speed TSP 1 shown in the downshift shift line Mfd ₁ in relation to the throttle opening TH.
Determine with S45. When the current turbine speed TSP′ is smaller than the set turbine speed TSP ₁ , the step
At S46, flag 2 for downshifting by one stage is read. Flag 2 is changed to 0 or 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 set to 1 in step S48.
A gear downshift is performed to complete the one gear downshift control. If it is determined in step S46 that the flag 2 is set, it means that downshifting is not possible, and the control is then completed. In addition, if it is determined in step S45 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 , the gear shift is performed according to the current throttle opening. Read down map and step
In S49, the set turbine speed TSP ₁ shown on the shift line Mfd ₁ of this map is multiplied by, for example, 1/0.8 to obtain the new set turbine speed TSP ₂ on the new shift line Mfd ₂ .
Set. Next, in step S50, if the current turbine rotation speed TSP' is smaller than the set turbine rotation speed TSP ₂ shown in the shift line Mfd ₂ , the control is completed, and if it is not smaller, the step is continued.
At S51, flag 2 is reset to 0, control is completed, and then lockup control is started. 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( 11), the set turbine rotation speed TSP ₁ corresponding to the throttle opening is read out. Next, in step S63, the current turbine rotation speed TSP' is read and
In step S64, this read current turbine rotation speed TSP' is checked against the lockup OFF map to determine whether or not this current turbine rotation speed TSP' is larger than the set turbine rotation speed TSP ₁ indicated on the shift line MOFF. It is determined whether If the current turbine rotation speed TSP' is smaller than the set turbine rotation speed _TSP1 , the lockup is released in step S65 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 speed TSP ₂ corresponding to the throttle opening TH is read out, and then in step S67, the current turbine speed TSP' is changed to the set turbine speed TSP ₂ . It is determined whether or not it is larger than . Then, 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 as is. Next, the basic configuration of the solenoid drive system as an electromagnetic means for speed change and the point of diagnosing its failure will be explained with reference to FIG. 14. The first solenoid SL1 is connected in series with the power supply transistor TR. When a low signal is output from the A terminal of the control unit 200 to the base of the power supply transistor TR, the power supply transistor TR becomes energized and the first solenoid SL1 is turned ON (energized). . And this first
Power supply transistor connected to solenoid SL1
The B terminal of the control unit 200 is connected to the collector serving as the output end of the TR. In addition, the 14th
In the figure, R is a resistor. Therefore, when both the first solenoid SL1 and the power supply transistor TR are normal and not disconnected or shot, when a low signal is output from the A terminal, the power supply transistor TR is energized and the first solenoid SL1 is turned on. As soon as B
A high signal is output to the terminal. Conversely, when the A terminal outputs a low signal, the transistor TR is cut off and the first solenoid SL1 is turned OFF (demagnetized).
At the same time, a low signal is output to the B terminal. In this manner, when both the power supply transistor TR and the first solenoid SL1 are normal, either the A terminal or the B terminal becomes high and the other becomes low. On the other hand, if one or both of the first solenoid SL1 or the power supply transistor TR is broken (broken or shorted), the A terminal and the B terminal will have a high-to-high or low-to-low relationship. Of course, the second solenoid SL1 and the third solenoid SL1 also have the same configuration as in FIG. 14. In this way, by looking at the high/low relationship between the A terminal and the B terminal for the drive system of each solenoid SL1, it is possible to know whether or not the drive system of the solenoid SL1 has failed. discrimination). In addition, in the above-mentioned failure determination,
Although it is impossible to know whether the solenoid is malfunctioning while it is ON, or whether it is malfunctioning when it is OFF, as will be described later, the present invention eliminates this problem. ing. As described above, when it is determined in step S1 that the solenoid drive system is malfunctioning, auxiliary shift control is performed in step S16, which will be explained with reference to FIG. This auxiliary shift control is different from the main shift characteristic in that it performs a two-speed shift based on a shift characteristic predetermined based on the throttle opening degree and vehicle speed. First, in steps S71 and 72, the current throttle opening TH' and the current vehicle speed VSP' are read in sequence, and then in step S73, the current throttle opening is read from the shift-up map (shift-up line) shown in FIG. It is determined whether the vehicle speed VSP ₁ corresponding to the throttle opening TH' is smaller than the vehicle speed VSP' on the shift up line, and if VSP'> VSP ₁ , the step
As will be described later in S75, a shift up is performed using two normal solenoid drive systems. If it is determined in step S74 that VSP'> VSP ₁ , then in step S76, the vehicle speed VSP ₂ corresponding to the current throttle opening TH' is determined from the downshift map (downshift line) shown in FIG. read out. Next, in step S77, the current vehicle speed is
It is determined whether or not VSP is smaller than the vehicle speed VSP ₂ on the shift down line, and if VSP'<VSP ₁ , in step S78, the normal 2
Downshifts are performed using two solenoid drive systems. Also, in step S77 above, VSP′<
If VSP is not ₁ , exit as is (no shift). Here, to explain in detail the shifts in steps S75 and 78 mentioned above, the 3rd shift as an electromagnetic means for shifting will be described.
The following Table 4 shows the relationship between the operating modes of the two solenoids SL1 to SL3 and the possible speeds (or gear ratios) depending on these operating modes. In addition, in this Table 4, the operation mode is...
This is an embodiment in which each of the solenoids SL1 to SL3 performs normal main shift control. In addition, the operating modes of the two normal solenoids (corresponding to Table 1) are shown in Table 5, which shows the relationship between upshifts, downshifts, and gear positions (or gear ratios). In Table 5, gears without parentheses indicate when the faulty solenoid is OFF, and gears with parentheses indicate when the faulty solenoid is ON.

【table】

[Table] From this Table 5, it is easily understood that even in the auxiliary shift control, it is possible to take two gears, a high gear and a low gear. In other words, if solenoid SL1 remains OFF and is malfunctioning, shifting between 2nd and 3rd gears,
Either a shift between 3rd and 4th gear, or a shift between 1×4 and 4th gear is made depending on the solenoid drive system that has failed. In addition, if the solenoid remains ON and is malfunctioning, try shifting between 1st and 3rd gear, shifting between 1st and 2x4, or shifting between 1st and 3rd gear. Shifts are made in response to the failed solenoid drive system. Although the embodiments have been described above, the present invention is not limited thereto, and includes, for example, the following cases. There may be four or more electromagnetic means for speed change,
The greater the number of electromagnetic means for speed change, the more likely it is that if one electromagnetic means for speed change (drive system) breaks down,
The degree of freedom of the gears that can be selected by the remaining normal gearshift electromagnetic means can be increased, and it is also possible to increase the number of gears to three or more during auxiliary gearshift control. The main shift control characteristic may be determined, for example, based on the relationship between the throttle opening (engine load) and the vehicle speed. The auxiliary shift control characteristic may be determined, for example, based on the relationship between the throttle opening (engine load) and the turbine rotation speed. Lockup may also be performed during auxiliary shift control (step S15 may be omitted). (Effects of the Invention) As is clear from the above, the present invention has the following advantages:
If one gear shift electromagnetic means fails, auxiliary gear shift control is performed using a plurality of gear stages, so that troubles in running are less likely to occur than when traveling with only one gear stage. In addition, the above-mentioned auxiliary shift control can be performed regardless of whether the electromagnetic means for shifting itself has failed while being turned on or has failed while being turned off.In other words, if the electromagnetic means for shifting itself has failed, This is extremely practical since there is no need to distinguish and detect faults in the parts that feed power to the faults in a particularly strict manner. Of course, if the electromagnetic means for speed change is ON or
If it is possible to detect a failure when it is OFF, it becomes possible to set the auxiliary shift control more preferably.

[Brief explanation of drawings]

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, FIG. 10, and FIG. 12 are flowcharts showing examples 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. 13 is a diagram showing an example of an auxiliary shift diagram. FIG. 14 is a diagram showing a simplified example of a drive circuit for the electromagnetic means for speed change. 1: Engine output shaft, 20: Multi-stage gear transmission mechanism, 200: Control unit, EN: Engine, SL
1 to SL3: Solenoid valve (electromagnetic means for speed change).

Claims (1)

[Scope of Claims] 1. A gear-type transmission mechanism interposed in an engine drive system, and at least three gear-shift electromagnetic means for controlling the supply of pressure fluid to a fluid-type actuator that performs a gear-shift operation of the gear-type transmission mechanism. Based on the predetermined main shift characteristics,
main shift control means that outputs a shift up signal or a shift down signal to each of the shift electromagnetic means to perform shift control between a plurality of gear stages; a failure detection means that detects a failure of the shift electromagnetic means; Prohibition means receives an output from the failure detection means and prohibits control by the main speed change control means when the speed change electromagnetic means fails; When a failure occurs, the failed electromagnetic means for speed change is removed from the target of speed change operation, and the remaining normally operating electromagnetic means are used to create a plurality of gears that function normally regardless of the failure state of the failed electromagnetic means for speed change. A failure diagnosis device for an automatic transmission, comprising: an auxiliary shift control means for performing shift control at a gear position.