JPH09236174A - Automatic transmission controller for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the accuracy of detecting an engine revolution number in a low-speed traveling condition by processing a signal from an engine revolution number detecting means as an engine revolution number while a lock-up clutch is disengaged and processing a signal from an input revolution number detecting means as an engine revolution number while the clutch is engaged. SOLUTION: In a vehicle provided with a torque converter 6 having a lockup clutch 5 and a belt type continuously variable transmission 2, an engine revolution number sensor 65 and an input revolution number sensor 62 are provided in order to highly accurately detect a revolution number during a low-speed revolution. The engaging condition of the lockup clutch 5 is determined by an ECU and if the clutch 5 is in a disengaged condition, a signal from the engine revolution number sensor 65 is inputted as an engine revolution number. On the other hand, if the clutch 5 is in an engaged condition, a signal from the input revolution number sensor 62 for detecting the revolution number of a primer sieve 23 is inputted an engine revolution number. Thus, an engine revolution number is highly accurately detected with high resolution.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is suitable for use in an automatic transmission mounted on a vehicle, particularly in a continuously variable automatic transmission equipped with a torque converter having a lockup clutch and a belt type continuously variable transmission (CVT). More specifically, the present invention relates to a control device for the rotation speed detection means.

[0002]

2. Description of the Related Art Conventionally, automatic transmissions, such as continuously variable automatic transmissions, are provided with respective rotation sensors for detecting engine speed, input speed (primary sheave speed), and vehicle speed (secondary sheave speed). The gear ratio and the like are controlled based on the detected rotational speed.

Generally, a rotation speed sensor is formed by directly forming a concavo-convex shape on a rotating member such as a primary or secondary sheave, or by fixing a concavo-convex member formed by pressing to the rotating member. An electromagnetic pickup (magnetic sensor) is arranged in close proximity to the detection member, and a change in dielectric current generated due to the unevenness of the detected member passing through the electromagnetic pickup portion in a non-contact manner is applied to a control unit (microcomputer). The rotational speed (rotation angle) of the detected member is detected by performing the measurement.

[0004]

Recently, it has been required to detect the number of revolutions at low speed revolutions such as creep prevention control and reverse inhibition control. In particular, when slip control of the lock-up clutch is performed due to improvement of fuel consumption and regulation of torque ratio amplification of the torque converter, high measurement accuracy of the engine speed at low speed rotation is required.

By the way, in the rotation speed sensor, when the number of irregularities of the member to be detected is increased, the measurement accuracy of the low speed rotation speed is improved, but at the time of high speed rotation, the rotation speed calculation processing by the control unit is increased and other processing is performed. However, there is a risk that this may hinder the operation of the vehicle, and the improvement in accuracy during low-speed rotation by increasing the number of irregularities is restricted by the counter processing capacity of the control unit.

Therefore, according to the present invention, when the lockup clutch is directly connected at a high speed, the engine speed is detected by the input speed sensor, and the engine speed sensor is dedicated to the low speed rotation. It is an object of the present invention to provide a resolved automatic transmission control device for a vehicle.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and transmits a torque from an engine to a transmission (2) via a torque converter (6) having a lockup clutch (5). ), And further, the torque transmitted by the transmission is transmitted to the axles (60, 61), the engine speed detecting means (1) for detecting the engine speed in the automatic vehicle transmission (1). 65),
An input speed detecting means (62) for detecting an input speed of the transmission; a lockup detecting means (100a) for detecting whether the lockup clutch (5) is in an engaged state or a disengaged state; When the lockup detecting means detects the non-engaged state of the lockup clutch, the signal from the engine speed detecting means (65) is input and processed as the engine speed, and the lockup clutch engagement is performed. A switching control means (100) for switching the signal from the input rotation speed detection means (62) so as to perform input processing as the engine rotation speed when a matching state is detected;
It is characterized by having.

Preferably, the lockup clutch is slip controlled.

Further, it is preferable that the transmission is a belt type continuously variable transmission (1).

[Operation] Based on the above configuration, the control unit (10
Signals from the respective sensors such as the accelerator sensor (64) and the output speed sensor (63) are input to (0), and the lockup solenoid valve (97) is locked up by processing these signals. Signal or lockup ON signal is output to lockup clutch (5)
Are engaged or disengaged. When the lockup detecting means (100a) detects the non-engaged state of the lockup clutch, the switching control means (100
In b), the signal from the engine speed sensor (65) is directly processed as the engine speed, and when the engagement state of the lockup clutch is detected, the switching control means causes the input speed sensor (62) to operate. ) Signal is processed as an engine speed.

Note that the reference numerals in parentheses are for comparison with the drawings, but do not limit the configuration of the present invention.

[0012]

According to the first aspect of the present invention, since the signal from the input speed sensor is input as the engine speed in the high-speed traveling state in which the lockup clutch is engaged, the engine speed is processed. As the sensor, a sensor capable of detecting with high resolution without being restricted by the counter processing capacity of the control unit during high speed traveling can be used, and the detection accuracy of the engine speed during low speed traveling can be controlled. It is possible to improve the cost without increasing the processing capacity of the unit.

According to the second aspect of the present invention, slip control of the lock-up clutch requires highly accurate detection of the engine speed during low-speed traveling, but for example, the rotated member detected by an electromagnetic pickup. It is possible to easily deal with the problem by improving the detection accuracy of the engine speed by increasing the number of the uneven portions.

According to the third aspect of the present invention, in the belt type continuously variable transmission, the input torque is limited by the belt capacity and the like, but the torque ratio amplification of the torque converter at the start is controlled by slip control of the lockup clutch. Therefore, the restriction within the range of the torque capacity of the CVT can be easily performed by the highly accurate detection of the engine speed during the low speed running described above.

[0015]

1 is a diagram showing a continuously variable automatic transmission 1 for a vehicle to which the present invention can be applied. The continuously variable automatic transmission is a belt type continuously variable transmission (CVT) 2, A forward / reverse / mode switching device 3, a torque converter 6 having a lock-up clutch 5 incorporated therein, a counter shaft 7, and a differential device 9 are provided, and these devices are covered by a split case.

The torque converter 6 includes an engine output shaft 1
0, a pump impeller 11 connected via a front cover 17, a turbine runner 13 connected to an input shaft 12, and a stator 16 supported via a one-way clutch 15. The lock-up clutch 5 is interposed between the front cover 17 and the front cover 17. In the drawing, reference numeral 20 denotes a damper spring interposed between the lock-up clutch plate and the input shaft,
An oil pump 21 is connected to and driven by the pump impeller 11.

The CVT (belt type continuously variable transmission) 2 includes a fixed sheave 23 fixed to a primary shaft 22 and a movable sheave 2 slidably supported on the shaft.
5, a secondary pulley 31 comprising a fixed sheave 29 fixed to a secondary shaft 27 and a movable sheave 30 supported only slidably on the shaft, and a primary pulley 26 wound around these pulleys. And a metal belt 32.

Further, a hydraulic actuator 33 composed of a double piston is arranged on the back surface of the primary side movable sheave 25, and a hydraulic actuator 3 composed of a single piston is arranged on the rear surface of the secondary side movable sheave 30.
5 are arranged. The primary hydraulic actuator 33 includes a cylinder member 36 fixed to the primary shaft 22, a reaction force support member 37, and a movable sheave 25.
And a first hydraulic chamber 41 is formed on the back surface of the cylindrical member 39, the reaction force support member 37, and the movable sheave 25,
The second hydraulic chamber 42 is constituted by the cylinder member 36 and the piston member 40. The first hydraulic chamber 41 and the second hydraulic chamber 42 communicate with each other through a communication hole 37a, and generate an axial force substantially doubled as compared with the secondary hydraulic actuator 35 by the same hydraulic pressure. I do. on the other hand,
The secondary-side hydraulic actuator 35 has a reaction force support member 43 fixed to the secondary shaft 27 and a tubular member 45 fixed to the back of the movable sheave 30. These two members constitute one hydraulic chamber. A preload spring 47 is contracted between the movable sheave 30 and the reaction force support member 43.

The forward / reverse / mode switching device 3 includes a double pinion planetary gear 50 for reverse / forward / reverse switching, a reverse brake B ₁ , a first (D range) clutch C ₁ , and a second.
(L range) clutch C ₂ and one-way clutch F
The has, between the fixed sheave 23 of the input shaft 12 and the primary pulley 26, and the second clutch C _2, the first clutch C ₁ and the one-way clutch F are arranged in parallel. In the planetary gear 50, the sun gear S is connected to the input shaft 12, and the carrier CR supporting the first and second pinions P ₁ and P ₂ is connected to the primary side fixed sheave 23, and The ring gear R is connected to the reverse brake B ₁ .

A large gear 51 and a small gear 52 are fixed to the counter shaft 7. The large gear 51 meshes with a gear 53 fixed to the secondary shaft 27, and the small gear 52 is a gear 55 of the differential device 9. Is engaged. The differential device 9 is configured such that the rotation of the differential gear 56 supported by the differential case 56 having the gear 55 causes the left and right axles 60, 6 to rotate through left and right side gears 57, 59.
1 is transmitted.

Further, a plurality of, for example, 20 concave and convex portions 23a are formed on the outer peripheral portion of the primary side fixed sheave 23 at equal intervals by gear cutting, and a case (not shown) faces the convex and concave portions. ) Is fixed to the electromagnetic pickup 6
2 are arranged. Similarly, a plurality of, for example, twelve concavities and convexities 29a are formed on the outer peripheral portion of the secondary side fixed sheave 29 at equal intervals by gear cutting, and the electromagnetic pickup 63 is fixed to the case so as to face the concavo-convex portions. Are arranged. These electromagnetic pickups 62, 63
Respectively, the detection surfaces thereof are arranged in the vicinity of the concavo-convex portion, and constitute a primary (input) rotational speed sensor and a secondary (output) rotational speed (that is, vehicle speed) sensor for detecting the concavo-convex portion. On the other hand, in FIG. 1, an electromagnetic pickup is shown as 65, which is arranged close to the front cover 17. For example, the electromagnetic pickup 65 is coaxial with a signal rotor or a crank pulley provided in the distributor. The engine speed sensor is provided in the vicinity of the signal displacer provided in the shape of a circle and detects a large number of, for example, 106 irregularities formed on these rotors or plates.

Next, the hydraulic circuit of the continuously variable transmission will be described with reference to FIG. In the figure, 21 is the oil pump, 70 is an oil pump control valve, 7
Reference numeral 1 is a solenoid valve for the control valve.
Reference numeral 72 denotes a primary regulator valve, 73 denotes a secondary regulator valve, 75 denotes a linear solenoid valve for controlling line pressure, and 76 denotes a modulator valve for a solenoid valve.

Reference numeral 77 is a manual valve, and the hydraulic pressure of the line pressure port 1 is switched to the port 2 or 3 by manual operation as shown in the table. 79 modulator valve, 80 is C2 control valve, the duty control solenoid valve 81, C2, C1, respectively the clutch C _1, the hydraulic servo for the C _2, B1 hydraulic servo the brake B _1, is 90, 91 These are accumulators for B1 and C1, respectively. Reference numeral 92 is a ratio control valve, 93 is a linear solenoid valve for CVT control (ratio control), and 33 and 35 are the primary side and secondary side hydraulic actuators.

Reference numeral 95 is a lockup control valve, 96 is a lockup relay valve, and 97 is a linear solenoid valve for lockup control. Reference numeral 6 denotes a torque converter having the lock-up clutch 5, 6a denotes an oil passage communicating with the lock-up off-side oil chamber 5a, and 6b denotes an oil passage communicating with the lock-up on-side oil chamber 5b. In the figure, x is a drain port.

As shown in FIG. 3, the engine speed sensor 65, the input speed sensor 62, and the output speed sensor 6 are shown.
The signals from the sensor 3 and the output speed sensor 63, the sensor 64 for detecting the accelerator depression amount, that is, the throttle opening, and the sensor 66 for detecting the position position of the manual valve are control units (ECU) 100 including an in-vehicle computer.
Sent to Various calculations are performed by the ECU 100, and the oil pump solenoid valve 71, the line pressure linear solenoid valve 75, the C ₂ control duty solenoid valve 81, the ratio control (shift) linear solenoid valve 93, and the lockup control linear valve. A predetermined signal is output to the solenoid valve 97.

Further, the control section 100 is provided with a lockup detecting means 100a and a switching control means 100b. The lockup detection means 100a detects whether or not the lockup clutch 5 is currently engaged. In the continuously variable transmission, the map selected by the position sensor 66 is output from the accelerator sensor 65. It is detected by reading based on the accelerator opening signal and the signal from the input rotation speed sensor 62. In the multi-speed automatic transmission, the lockup clutch is controlled by reading the map from the accelerator opening and the vehicle speed. The switching control unit 100b switches the engine speed input to the control unit 100 between the signal from the engine speed sensor 65 and the signal from the input speed sensor 62, and the lockup detection unit 100a locks up. When the disengaged state of the clutch is detected, the signal from the engine speed sensor 65 is directly processed as the engine speed, and when the engaged state of the lockup clutch is detected, the input speed sensor 62 is input. The signal from is input and processed as the engine speed.

Next, the operation based on the above configuration will be described. A predetermined hydraulic pressure is generated by the rotation of the oil pump 21 based on the engine rotation, and the hydraulic pressure is generated by the pressure control valve 72 based on the linear solenoid valve 75 controlled by the signal from the control unit 100 calculated based on the load torque or the like. The line pressure is adjusted by being controlled. In addition, when the line pressure is not required, such as in the stopped state, the solenoid valve 71 is controlled based on the signal from the control unit, and the oil pump control valve 7
By operating 0 to the right half position, the hydraulic pressure from the pump 21 is directly circulated.

In the D range and the L range of the manual valve 77, the hydraulic pressure from the port 1 is supplied to the first clutch hydraulic servo C1 via the port 2, and the first clutch C ₁ is engaged. In this state, the rotation of the engine output shaft 10 is transmitted to the primary pulley 26 via the torque converter 6, the input shaft 12, the one-way clutch F, and the first clutch C ₁ , and is further appropriately changed in speed C.
It is transmitted to the secondary shaft 27 via VT2 and then to the left and right axles 60, 61 via the counter gear and the differential device 9.

When the manual valve 77 is in the D range, only the first clutch C _{1 with} the one-way clutch F interposed is engaged, so the engine brake does not operate during coasting. When the manual valve 77 is shifted to the L range, a duty signal is output from the control unit 100 to the solenoid valve 81 based on the detection of the shift position to control the C ₂ control valve 80,
A predetermined pressure is applied to the hydraulic servo C2, and the second clutch C
Connect ₂ too. As a result, the coast engine brake operates. It should be noted that it is desirable that the D range and the L range differ in the gear ratio of the CVT 2 and the engagement point of the lockup clutch with respect to the vehicle traveling state (for example, throttle opening and vehicle speed).

When the manual valve 77 is operated in the reverse range, the hydraulic pressure from the port 1 is supplied to the brake hydraulic servo B1 via the port 3. In this state, the ring gear R of the planetary gear 50 is locked,
The rotation of the sun gear S from the input shaft 12 is taken out by the carrier CR as a reverse rotation, and the reverse rotation is applied to the primary pulley 2.
6 is transmitted.

In the CVT 2, the hydraulic actuator 35 of the secondary pulley 31 is supplied with the line pressure from the primary regulator valve 72, and acts on the belt clamping force according to the load torque. On the other hand, the linear solenoid valve 93 is controlled based on the shift signal from the control unit 100, the ratio control valve 92 is controlled by the output pressure from the solenoid valve, and the pressure regulation from the output port is controlled by the double piston of the primary pulley. Is supplied to the hydraulic actuator 33.
The gear ratio of T2 is appropriately controlled.

The torque of the engine output shaft 10 is
The torque is transmitted to the input shaft 12 via the torque converter 6, and particularly at the time of starting, the speed is changed by the torque converter 6 so that the torque ratio is increased and transmitted to the input shaft 12, and the vehicle starts smoothly. The torque converter 6
Has a lock-up clutch 5, and when the vehicle is running at high speed and stable, the lock-up clutch is engaged,
The engine output shaft 10 and the input shaft 12 are in a directly connected state, and the loss due to the oil flow of the torque converter is reduced. Further, slip control is performed so that the rotation difference between the input side and the output side of the lockup clutch becomes a predetermined value in the low / medium speed range until the clutch is completely engaged.

That is, the map is selected by the position sensor 66 depending on whether it is in the D range or the L range, and the accelerator opening degree from the accelerator sensor 65 and the input rotation speed point from the input rotation speed sensor 62 are selected from the above map. The lockup OFF signal or ON signal is output from the reading / control unit 100. When the output port 97a of the linear solenoid valve 97 outputs the lockup OFF pressure (0 pressure) based on the signal from the control unit 100, the lockup relay valve 96 is in the left half position, and
The lockup control valve 95 is also in the left half position. In this state, the line pressure of the line pressure oil passage Pl is supplied to the lockup OFF port 6a via the input port a and the output port b of the relay valve 96, and then from the lockup ON port 6b to the port c of the relay valve 96. , D to the clerk 99, whereby the lockup clutch 5 is held in the disengaged state. At this time, the line pressure of the line pressure oil passage Pl is controlled by the control valve 95.
Relay valve 9 via input port e and output port f of
6 but is blocked at port g.

On the other hand, when the linear solenoid valve 97 inputs the lockup ON signal from the control unit 100, ON pressure is output from the output port 97a, and the lockup relay valve 96 and the control valve 95 are switched to the right half position. In this state, the line pressure of the oil passage Pl is supplied from the port h of the relay valve 96 to the lockup ON port 6b via the port c, and from the lockup OFF port 6b to the ports b and g of the relay valve 96. Is guided to the port f of the control valve 95 and discharged from the drain port, whereby the lockup clutch 5 is held in the connected state.

When the lock-up clutch is slip-operated, the control unit 100 is instructed to rotate the engine speed sensors 6 on the input side and the output side of the lock-up clutch.
5 and the signal from the input speed engine 62 are input, and a signal is output so that the difference between them is a predetermined value. Based on this signal, the linear solenoid valve 97 outputs a predetermined hydraulic pressure lower than the ON pressure. Depending on the predetermined hydraulic pressure, the relay valve 96 is held in the left half position, that is, the lockup ON position, and the hydraulic pressure communicating with the lockup ON port 6b is supplied to the feedback oil chamber j of the control valve 95 via the port i. Has been done.
Further, a predetermined control pressure from the linear solenoid valve 97 acts on the control oil chamber k of the control valve 95, and the valve 95 controls the oil pressure of the feedback oil chamber j and the control oil chamber of the control oil chamber k. Balanced by and, port f becomes line pressure input port e and drain port x
Communicate at a predetermined rate. This locks up O
The hydraulic pressure from the FF side port 6a becomes a predetermined pressure, the ON side oil chamber 5b and the OFF side oil chamber 5a of the torque converter 6 are balanced, and the lockup clutch 5 enters a predetermined slip state.

In each control based on the signal from the control unit 100, such as the shift control output to the shift solenoid 93 and the line pressure control output to the line pressure solenoid 75, it is necessary to calculate the input torque. Therefore, it is necessary to detect the engine speed in addition to the accelerator opening, the input speed and the output speed. Also, in slip control of the lock-up clutch, it is necessary to detect the engine speed as well as the input speed.

Next, the process for determining the engine speed will be described with reference to FIG. The lockup detecting means 100a of the control unit determines whether or not the lockup clutch is engaged (S1). That is, as described above, the control unit 100 outputs the lockup OFF signal to the lockup solenoid 97 or the lockup ON signal.
Detects whether a signal is being output. When the lockup clutch 5 is in the disengaged state (the output state of the OFF signal), the signal from the engine speed sensor 65 is input and processed as the engine speed (S2). On the other hand, when the lockup clutch is in the engaged state (ON signal output state), the signal from the rotation speed sensor (input rotation speed sensor) 62 of the primary sheave 23 is input and processed as the engine rotation speed (S3).

As a result, during low-speed traveling with the lockup clutch in the non-engaged state, a large number of uneven portions (for example, 1
Based on the engine speed sensor 65 that detects (06) by an electromagnetic pickup, the engine speed is detected with high resolution and high accuracy. Further, during high-speed traveling with the lockup clutch engaged, the engine speed and the input speed are in an integral relationship, and a signal from the input speed (primary sheave speed) sensor 62 is input as the engine speed. To do. Therefore, by detecting a relatively small number of irregularities (for example, 20) with an electromagnetic pickup, it is not necessary to count the engine speed sensor 65 that detects the large number of irregularities during high-speed rotation.
The counter processing capacity of the control unit can be secured.

Further, it is desirable to use the slip control of the lock-up clutch even at the time of starting.

The engine speed Ne, the input speed Ni, and the throttle opening θ are read by monitoring the engine speed sensor 65, the input speed sensor 62, and the accelerator sensor 64. Then, based on the engine speed Ne and the throttle opening θ, the engine torque Te is estimated by reading from the map. Further, the torque ratio t of the torque converter is estimated by reading from the map based on the ratio of the input speed Ni and the engine speed Ne, and the input torque T is calculated based on the torque ratio t.
Calculate i (Ti = Te xt). On the other hand, the upper limit torque Tlim is set based on the torque capacity of the continuously variable transmission 1 which is limited by the capacity of the belt 32 and the axial force of the secondary hydraulic actuator 35. Then, the calculated input torque Ti and the set upper limit torque T
lim is compared, and if Ti ≥Tlim, the slip-up operation of the lockup clutch 5 is performed. This allows
For example, when the torque ratio of the torque converter 6 increases due to a stall start or the like and the capacity of the continuously variable transmission 1 is about to be exceeded, the lockup clutch 5 slips (when the lockup clutch is completely engaged, When the torque ratio becomes 1, the increase in the torque ratio of the torque converter 6 is restricted, and the torque of the input shaft 12 is suppressed within the torque capacity of the continuously variable transmission. That is, the range in which the torque Ti of the input shaft during slip operation calculated by the control unit 100 based on the engine speed Ne, the input shaft speed Ni and the throttle opening θ does not exceed the upper limit torque of the continuously variable transmission. The linear solenoid valve 97 is controlled by feedback control so that the lockup clutch 5 slips to reach a predetermined value.

When performing the slip control at the time of starting the vehicle, it is necessary to detect the engine speed at a high accuracy during low speed running. As described above, while ensuring a sufficient counter capacity at high speed, it is high at low speed. Since the engine speed can be detected by the resolution, it is possible to sufficiently meet the above requirements.

Similarly, it is possible to sufficiently deal with the control that requires highly accurate detection of the engine speed during low speed running, such as creep prevention control and reverse prohibition control. Further, although the above-described embodiment describes the continuously variable automatic transmission, this is an automatic transmission that switches the clutch and the brake in response to a signal from the control unit to switch the transmission system of the transmission gear to multiple stages. Of course, the same can be applied to.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a continuously variable transmission according to the present invention.

FIG. 2 is a diagram showing the hydraulic circuit.

FIG. 3 is a diagram showing the electric control part.

FIG. 4 is a flowchart showing an engine speed determination process.

[Explanation of symbols]

1 continuously variable transmission 2 belt type continuously variable transmission (CVT) 5 lockup clutch 6 torque converter 10 engine output shaft 12 input shaft 60, 61 axle 62 input (primary sheave) rotation speed means (sensor) 63 output (secondary sheave) ) Rotation speed means (sensor) 65 Engine speed (sensor) 100 Control unit 100a Lock-up clutch detection means 100b Switching control means

Claims (3)

[Claims] 1. An automatic transmission for a vehicle, wherein torque from an engine is transmitted to a transmission through a torque converter having a lockup clutch, and the torque changed by the transmission is transmitted to an axle. An engine speed detecting means for detecting an engine speed, an input speed detecting means for detecting an input speed of the transmission, and a lock for detecting whether the lockup clutch is in an engaged state or a disengaged state. And a lockup detecting means for inputting a signal from the engine speed detecting means as an engine speed when the lockup detecting means detects the disengaged state of the lockup clutch, and the lockup When the engagement state of the clutch is detected, the signal from the input rotation speed detecting means is input as the engine rotation speed so as to be processed. Control device for a vehicular automatic transmission, characterized in that it comprises a switching control means for obtaining, a. 2. The control device for an automatic transmission for a vehicle according to claim 1, wherein the lock-up clutch is slip-controlled. 3. The control device for an automatic transmission for a vehicle according to claim 1, wherein the transmission is a belt-type continuously variable transmission.