JPH09133203A - Method and apparatus for detecting turbine speed of automatic transmission - Google Patents

Abstract

(57) An object of the present invention is to provide an inexpensive and highly reliable turbine speed detection method and device. SOLUTION: The turbine rotation speed is calculated from both outputs of a rotation speed sensor provided facing a rotating body located outside a transmission gear train and a rotation speed sensor provided on an output shaft. The turbine speed is detected without directly facing the speed sensor to the turbine shaft at a deep place. [Effect] Since the sensor can be mounted from the outside of the transmission, it is easy to obtain mounting accuracy, maintenance is easy, and reliability is high. There is no need for an elongated sensor to be inserted deeply, and a general inexpensive sensor can be used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control system for an automatic transmission of an automobile, and particularly, in order to obtain a shifting performance that is comfortable to ride in, a highly accurate shifting transient that utilizes information of a turbine speed of a torque converter. The present invention relates to a method and an apparatus for detecting a turbine speed suitable for use in the control of the turbine.

[0002]

2. Description of the Related Art A vehicle transmission has a structure as shown in FIGS. 1, 2 and 3, and the rotational force of an engine 1 is transmitted to a gear train of a transmission 3 via a torque converter 2. .
The crankshaft 4 of the engine 1 is the torque converter 2
It is connected to the pump impeller 5 and circulates the torque converter oil. The turbine impeller 6 facing the pump impeller 5 is rotated by the circulating torque converter oil, and the engine torque is amplified at this time. The amplified rotational force is transmitted to the planetary gear at the rear stage via the turbine shaft 7. This transmission 3 has two sets of planetary gears, the front stage is composed of a sun gear 8, a planetary gear 9, a carrier 10 and a ring gear 11, and the rear stage is composed of a sun gear 12 and a planetary gear 1.
3, a carrier 14, and a ring gear 15. The rotation of the turbine shaft 7 is transmitted to the sun gear 12 in the rear stage, is changed in speed, and is transmitted from the carrier 14 in the rear stage to the output shaft 16.

A clutch 1 connected to a planetary gear is used for shifting.
It is performed by fastening and releasing 7,18. When the clutch 17 is compressed by the hydraulic pressure, the frictional force increases and the clutch 17 is engaged. The one-way clutch 18 is engaged only when torque is applied in a predetermined direction. The shift control is a control in which the hydraulic pressure applied to the clutch is adjusted using a solenoid valve, and a solenoid current is generally controlled by a microcomputer.

For the shift control, feedforward control by so-called program control of a predetermined procedure is usually used. Therefore, in order to perform fine control, it is necessary to use highly accurate control information. Generally, the engine speed and the output shaft speed are used for control, but especially during a shift transition, unless the timing of clutch engagement / disengagement is correctly adjusted, a shift shock will occur and riding comfort will deteriorate. It is necessary to know the input / output speed of the transmission accurately. However, as shown in FIGS. 1, 2, and 3, a torque converter 2 is provided between the engine 1 and the transmission 3, and the torque converter 2 transmits the rotational force via oil, so that the speed is reduced. There is a slip called a ratio, and the engine speed and the turbine speed usually do not match. Therefore, conventionally, as shown in FIGS. 2 and 3, in order to accurately grasp the turbine rotation speed, a turbine rotation speed sensor 19 is directly provided on the turbine shaft 7 to detect the rotation speed. However, since the turbine shaft 7 is located at the center of the transmission, in the rear-wheel drive vehicle, as shown in FIG. 2, the turbine speed sensor 19 is deep from a narrow gap.
Must be inserted and detected. This means that the tip of the long sensor is opposed to the turbine shaft 7 while maintaining a small air gap, and the mounting accuracy is high, and it is sturdy to prevent the gap from fluctuating against vibration. Precise mounting hardware is required, and such a structure is expensive. It is also possible to provide a short rotation sensor inside the transmission and mount it close to the turbine shaft 7, but in this case, it is necessary to draw a lead wire in the oil and wire it to the outside.
Not only is it inferior in assemblability, but when replacing the sensor when it has failed, the whole must be disassembled, and maintainability is poor. In either case, a tooth groove for rotation detection is directly processed on the turbine shaft 7. However, since the turbine shaft 7 is relatively thin, it is not possible to form a deep tooth groove. There is a problem that the output signal level of 19 cannot be increased.

In the front-wheel drive vehicle, as shown in FIG. 3, the transmission output is transmitted to the differential gear 21 via the idle gear 20, so that if the output shaft 16 is made hollow, an extension shaft 22 for the turbine shaft is provided therein. Through which the toothed wheel 23 can be attached to the transmission end and the turbine speed sensor 19 can be attached. By doing so, an inexpensive commercially available rotational speed sensor can be used as the turbine rotational speed sensor. However, this method is not necessarily an inexpensive method because the output shaft 16 needs to be hollowed, the processing cost is high, and the bearing 24 for holding the thin turbine shaft extension shaft 22 is also required.

That is, the conventional method has a problem that it does not satisfy all the conditions such as the processing accuracy of the mounting portion, the assembling property, the maintainability, and the processing cost.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to eliminate such inconvenience and to provide a turbine speed detecting method and apparatus for obtaining accurate turbine speed information by an inexpensive method.

[0008]

According to the present invention, the rotation speed sensor is not attached to the turbine shaft, the rotation speed of the clutch drum 25 and the like located outside the gear train is detected, and the turbine rotation speed is calculated. It was configured.

In this method, the rotational speed of the clutch drum 25 and the rotational speed of the output shaft are applied to a predetermined calculation formula to calculate the turbine rotational speed by a simple proportional calculation. The calculation formula is switched between two formulas depending on the situation, but the condition for switching is determined by the state of the shift speed.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention C shown in FIG.
An explanation will be given using a transmission called an RCR type as an example. This type of transmission 3 has two sets of planetary gears, and since the carrier and the ring gear are connected to each other, this name is given. Fig. 1 shows the attachment part of the rotation speed sensor.
A drum rotation speed sensor 26 is attached from the outside of the transmission case so as to face the clutch drum 25 configured to enclose the two sets of planetary gears. As this sensor, a commercially available inexpensive rotation speed sensor can be used. A tooth groove is provided on the surface of the clutch drum 25 at a position facing the drum rotation speed sensor 26.
Since a groove for holding the clutch plate of the clutch 17 is provided in the, the groove may be used as it is. The information on the rotation speed obtained by counting the output pulses of the drum rotation speed sensor 26 is set as the drum rotation speed (here, N
c1).

In a rear-wheel drive vehicle, the output shaft 16 is usually provided with a parking wheel 27 and an output shaft rotation speed sensor 28 facing the parking wheel 27. In the case of a front-wheel drive vehicle, an output shaft rotation speed sensor 28 is provided facing the idle gear 20 as shown in FIG. Output shaft speed sensor 2
Here, the information on the rotation speed obtained by counting the output pulses of 8 is the output rotation speed No.

In FIG. 1, the clutch 17 is always engaged when moving forward. When the gear stage is in the first speed state, the one-way clutch 29 provided in the cascade is engaged with the clutch 17, and the one-way clutch 18 is also engaged, so that the ring gear 15 and the clutch drum 25 are fixed to the case of the transmission. There is. FIG. 4 shows the model of the transmission shown in FIG. 1, and the clutch 17 that is still engaged is omitted. A clutch 30 is provided between the turbine shaft 7 and the carrier 10, and a band brake 31 is provided between the sun gear 8 and the transmission case. Here, the number of teeth of the sun gear 8 is defined as zs1, the number of teeth of the ring gear 11 is defined as zr1, the number of teeth of the sun gear 12 is defined as zs2, and the number of teeth of the ring gear 15 is defined as zr2.

[0013]

[Table 1]

Table 1 shows the relationship between the operation of each clutch and the gear position. In the first speed, the band brake 31 is released, so the sun gear 8 is idling. Since the sun gear 8 is fixed when the band brake 31 is fastened, a rotational force is generated in the carrier 10 by the force of the ring gear 11 connected to the output shaft 16, the one-way clutch 18 disengages, and the clutch drum 25 and the ring gear 15 rotate. Since this is the second speed state and the ring gear 15 rotates, the output shaft 16 rotates faster than the first speed. Band brake 3
When 1 is released and the clutch 30 is engaged, all the elements of the two planetary gears integrally rotate at the same speed, the gear ratio becomes 1, and the third speed state is established. When the band brake 31 is further engaged, the carrier 10 is directly driven from the turbine shaft via the clutch 30, so that the ring gear 11 is accelerated and the output shaft 16 is rotated at a higher speed than the turbine shaft 7 into the fourth speed state. Become. At this time, since the ring gear 15 is accelerated, the one-way clutch 29 is released.

As can be seen from Table 1, since the one-way clutch 29 is engaged except in the fourth speed, the clutch drum 25 has the same rotational speed as the ring gear 15. Therefore,
The following equation is established using the relational expression of the rear planetary gears. When the turbine speed to be obtained is Nt, in the first speed state Nt = No (zs2 + zr2) / zs2 (1) Nc1 = 0 (2) In the second speed state Nt = No (zs2 + zr2) /zs2-Nc1.zr2/zs2 (3) At 3rd speed, the whole speed is the same, so Nt = No = Nc1 (4) At 4th speed, the one-way clutch 29 is released, so the relational expression of the rear stage planetary gear cannot be used, but the clutch 30 does not work. Since it is concluded, Nt = Nc1 (5)

[0016]

[Table 2]

Table 2 is a detailed classification of these relationships, including the mode at the time of gear transition. During the first period of gear shifting, the rotational speed does not change, only the torque changes. This period is called a torque phase. After that, the rotation speed changes due to slipping and engagement of the clutch. This period is called inertia phase. Since there is no change in the number of revolutions in the torque phase, it is expressed by the same equation as in the steady state. The rotation speed changes in the inertia phase, but as a result of analyzing this rotation speed, 1-2 inertia phase (inertia phase when shifting from 1st speed to 2nd speed) and 2-
It was found that the 3-inertia phase is represented by the relational expression of the second speed and the 3-4 inertial phase is represented by the relational expression of the fourth speed. By the way, if the formula (2) is substituted into the formula (3), the formula (1) is obtained, and if Nc1 = No is substituted into the formula (3), the formula (5) is obtained. It can be seen that all of the above can be expressed by equation (3). Similarly, 3rd and 4th
Speed can be expressed by equation (5). Therefore, when programming the arithmetic expression for control, the output shaft speed No and the clutch drum speed Nc1 are used, and the gear stage state flag Sp is used to obtain the formulas (3) and (5). By properly using, the turbine rotational speed Nt can be obtained by calculation without directly detecting it.

FIG. 5 shows the result of a simulation in which changes in the rotational speeds of various parts when the vehicle is accelerated at a constant acceleration are obtained. It was confirmed whether or not the result of this simulation and the result obtained by the above-mentioned calculation formula were in agreement. In FIG. 5, the region (1) is in the first speed steady state, and the region (2) is 1-
The inertia phase of the second speed change, the region (3) is the second speed steady state, the region (4) is the second speed inertia phase, the region (5) is the third speed steady state, and the region (6) is the third phase. Four
The inertia phase of the shift is shown, and the area (7) shows the fourth speed steady state. Line (a) is the turbine speed Nt, line (b) is the output speed No, and line (c) is the clutch drum speed Nc.
1, line (d) is the rotation speed Ns1 of the front stage sun gear 8, and line (e) is the rotation speed Nr2 of the rear stage ring gear 15.
For the clutch drum speed Nc1 on the line (c), the turbine speed Nt is calculated by applying the equation (3) between the first speed and the third speed, and the equation (5) is applied between the third speed and the fourth speed. It was verified that the value obtained by calculating the turbine rotation speed Nt completely overlaps the line (a) of the simulation result and coincides with it.

FIG. 6 shows the configuration of a computer control unit 41 used when embodying the present invention. The pulse voltages from the drum rotation speed sensor 26 and the output shaft rotation speed sensor 28 are waveform-shaped through the respective input circuits 42 and 43, and are applied to the counter input port of the CPU 44 of the microcomputer. In addition to these signals, various signals are input to the CPU 44, but parts not related to the present invention are omitted. The CPU 44 calculates the rotation speed of each axis by a method such as counting the number of pulses within a predetermined time or measuring the time interval of the pulses to obtain the rotation speed information Nc1 and No.
Store in AM45. These operations are performed by RO
It is executed according to the program stored in M46. The output of the CPU 44 excites solenoid valves 50, 51 and 52 via output circuits 47, 48 and 49 to control the hydraulic pressure of each clutch. Solenoid valve 50 to clutch 17, solenoid valve 51 to clutch 30,
Assuming that the solenoid valve 52 corresponds to the band brake 31, the shift can be performed by operating the solenoid valves 51 and 52 according to Table 1 while operating the solenoid valve 50 when moving forward.

In this control system, the turbine speed N
The procedure of the subroutine for calculating t is shown in the flowchart of FIG. The pulses from the drum rotation speed sensor 26 and the output shaft rotation speed sensor 28 are periodically processed by respective input processing subroutines (not shown), and the rotation speed information Nc is obtained.
Since 1 and No continue to be updated to the predetermined addresses in the RAM 45, these are read in steps 72 and 73, and in step 75, calculation is performed according to the gear stage state flag Sp. When the state flag Sp of the gear stage is equal to or lower than the third speed, the routine proceeds to step 76, where the turbine speed Nt is obtained using the equation (3). When the gear state flag Sp exceeds the third speed, the routine proceeds to step 77, where the turbine speed Nt is obtained using the equation (5).

Next, another embodiment of the present invention will be described. FIG.
The middle line (d) is the rotation speed Ns1 of the sun gear 8. The turbine speed Nt can also be calculated using this rotation speed Ns1. As a result of performing the same simulation as in the above-mentioned embodiment, the line (a) was completely overlapped in the third speed steady state of the region (5). Also in this case, one formula from the first speed to the third speed is 3
Although the first speed and the fourth speed can be expressed by another single expression, since the rotation direction of the sun gear 8 changes depending on the gear state, Ns
It is necessary to determine and calculate the sign of the value of 1. Since the sun gear 8 is connected to the brake drum 32 of the band brake 31, it can be easily installed from the outside of the transmission case by installing a drum rotation speed sensor facing the brake drum 32. It is possible to obtain the same effect as in the case of detecting.

Further, there is a ring gear 15 as an independent rotating part other than the input / output shaft of the gear train, and its rotation speed Nr2 is shown by a line (e) in FIG. Since it is difficult to attach the rotation speed sensor to the ring gear 15 from the outside of the transmission case, it is difficult to obtain the above-mentioned effect, but the turbine rotation speed can be calculated in the same manner as the calculation method of the above two examples. It was confirmed that the result also completely overlaps the line (a) in FIG. In this case as well, one formula from the first speed to the third speed,
The third speed and the fourth speed can be expressed by another single expression, but the determination for properly using the calculation expressions is easier than the above two examples, and Nr2 and Nr
You just need to compare the magnitude of o.

Although the above explanation has been made by taking the CRCR type transmission shown in FIG. 1 as an example, the method of the present invention is one of the three elements of the planetary gear, that is, the sun gear, the ring gear and the carrier.
It is nothing but measuring the rotational speeds of two elements that are easy to measure and calculating the rotational speeds of the remaining elements, so not only this type of transmission but also any type of transmission if it is a planetary gear transmission. Can also be applied. That is, since the following formula (6) is always established in the planetary gear, it is clear that the remaining number of revolutions can be calculated by giving two numbers of revolutions. The method of the present invention can be applied to any transmission by simply changing

Ns · zs + Nr · zr = Nc (zs + zr) (6)

[0025]

According to the method of the present invention, the rotational speed of the drum or the like located outside the transmission gear train is detected. Therefore, a commercially available inexpensive rotational speed sensor having a short length is used for the transmission case. It suffices to mount it from the outside, it is easy to obtain the accuracy of the gap, the maintainability is good, and it is possible to provide an inexpensive and highly reliable turbine rotation speed detection method and device.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram showing one embodiment of the present invention.

FIG. 2 is an overall configuration diagram showing a conventional turbine rotation speed detection method in a rear-wheel drive vehicle.

FIG. 3 is an overall configuration diagram showing a conventional turbine rotation speed detection method in a front-wheel drive vehicle.

FIG. 4 is a transmission model for explaining the operation of the embodiment of the present invention.

FIG. 5 is a time chart comparing the turbine rotational speed detected by the method of the present invention with the actual turbine rotational speed.

FIG. 6 is a block diagram showing the configuration of a control device according to an embodiment of the present invention.

FIG. 7 is a flowchart showing a calculation procedure of a turbine rotation calculation subroutine of one embodiment of the present invention.

[Explanation of symbols]

1 ... Engine, 2 ... Torque converter, 3 ... Transmission, 7
... Turbine shaft, 8, 12 ... Sun gear, 9, 13 ... Planetary gear, 10, 14 ... Carrier, 11, 15 ... Ring gear, 16 ... Output shaft, 25 ... Clutch drum, 26 ... Drum rotation speed sensor, 28 ... Output shaft rotation Number sensor, 31 ...
Band brake, 32 ... Brake drum, 41 ... Computer control device, 42, 43 ... Input circuit, 44 ... CP
U, 45 ... RAM, 46 ... ROM, 47, 48, 49 ...
Output circuit, 50, 51, 52 ... Solenoid valve.

Claims (10)

[Claims] 1. A pump impeller and a turbine impeller are provided,
A torque converter for transmitting rotation and torque, a plurality of planetary gear mechanisms for inputting rotation and torque from a turbine shaft with which the turbine impeller is engaged, and a gear ratio is determined by a combination of a plurality of gears. And a gear train for converting rotation and torque from the turbine shaft, and a clutch for selecting a combination of gears for obtaining a desired gear ratio from among the gears. An output shaft rotation speed sensor that detects the rotation speed of the output shaft of the row, and a planetary gear mechanism rotation speed sensor that detects the rotation speed of a part of the planetary gear mechanism, and an output from the planetary gear mechanism rotation speed sensor. A method for detecting a turbine rotational speed of an automatic transmission, characterized in that the rotational speed of the turbine shaft is obtained from the output from the output shaft rotational speed sensor. 2. The automatic transmission according to claim 1, wherein a clutch drum is fixed to the outside of the planetary gear mechanism, and the planetary gear mechanism rotation speed sensor detects the rotation speed of the clutch drum. Method for detecting turbine speed of turbine. 3. The brake drum according to claim 1, wherein a brake drum is fixed to at least one element of the planetary gear mechanism, and the planetary gear mechanism rotation speed sensor detects the rotation speed of the brake drum. Method for detecting turbine speed of automatic transmission. 4. The planetary gear mechanism rotation according to claim 1, wherein at least one element of the planetary gear mechanism is uniquely determined to have a magnitude relationship with the output shaft rotation speed depending on a state of combination of the gears. A method for detecting a turbine speed of an automatic transmission, wherein a number sensor detects a speed of the element. 5. The CRCR according to claim 1, wherein the gear train uses two sets of planetary gears as a carrier and a ring gear, and a plurality of the gears are connected to each other.
A method for detecting a turbine speed of an automatic transmission, which has a structure called a mold. 6. A pump impeller and a turbine impeller,
A torque converter for transmitting rotation and torque, a plurality of planetary gear mechanisms for inputting rotation and torque from a turbine shaft with which the turbine impeller is engaged, and a gear ratio is determined by a combination of a plurality of gears. And a gear train for converting rotation and torque from the turbine shaft, and a clutch for selecting a combination of gears for obtaining a desired gear ratio from the gears. An output shaft rotation speed sensor for detecting the rotation speed of the output shaft of the row, a planetary gear mechanism rotation speed sensor for detecting the rotation speed of a part of the planetary gear mechanism, an output from the planetary gear mechanism rotation speed sensor and the output A turbine of an automatic transmission, comprising: turbine rotation speed calculation means for obtaining a rotation speed of the turbine shaft from an output from a shaft rotation speed sensor. Rolling the number of the detection device. 7. The automatic transmission according to claim 1, wherein a clutch drum is fixed to the outside of the planetary gear mechanism, and the planetary gear mechanism rotation speed sensor detects the rotation speed of the clutch drum. Turbine speed detector. 8. The brake drum according to claim 1, wherein a brake drum is fixed to at least one element of the planetary gear mechanism, and the planetary gear mechanism rotation speed sensor detects the rotation speed of the brake drum. Turbine speed detection device for automatic transmission. 9. The planetary gear mechanism rotation according to claim 1, wherein at least one element of the planetary gear mechanism is uniquely determined to have a magnitude relationship with the output shaft rotation speed depending on a state of the combination of the gears. A device for detecting a turbine speed of an automatic transmission, wherein a number sensor detects a speed of the element. 10. The CRC according to any one of claims 1 to 4, wherein the gear train uses two sets of planetary gears as a carrier and a ring gear, and a plurality of them are connected to each other.
A turbine rotation speed detecting device for an automatic transmission, which has a structure called an R type.