JP2843842B2 - Transmission control device for continuously variable transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial applications]

The present invention provides an anti-lock brake system (hereinafter
More specifically, the present invention relates to a shift control device for a continuously variable transmission that determines whether the ABS is operating so that shift control corresponding to the ABS operation can be performed.

[Prior art]

In general, when a vehicle is suddenly braked while traveling on a wet pavement or a frozen road, wheels may be locked, and braking and steering cannot be performed. Further, even when the wheel is not locked, if the slip ratio of the wheel increases, sufficient control force or steering performance cannot be obtained. Therefore, in recent years, there has been a tendency to equip vehicles with an ABS that ensures a sufficient braking force and steering performance by controlling a slip ratio of a wheel during a brake operation within an appropriate region. As a control method of the ABS, a method using only hydraulic control, a method of performing electronic control in addition to the hydraulic control, and the like are known. On the other hand, as such a continuously variable transmission mounted on a vehicle, a belt-type continuously variable transmission that transmits power from a primary pulley on an input side to a secondary pulley on an output side via a drive belt is known. As an example, a hydraulic control system that controls the belt wrap radius of the primary pulley and the secondary pulley is provided. There is known an apparatus in which a secondary pressure according to a transmission torque is applied to prevent a drive belt from slipping. Here, the control valve of the hydraulic control system for controlling the primary pressure and the secondary pressure tends to be electronically controlled by a control unit, and the control unit transmits a signal such as a vehicle speed (the rotational speed of a secondary pulley) and a throttle opening degree. It has been considered that an appropriate target gear ratio is determined by inputting the gear ratio according to the traveling conditions of the vehicle, and a gear ratio control signal is output so that the gear ratio of the continuously variable transmission follows the target gear ratio. An electronic control of the shift control of the continuously variable transmission is disclosed in, for example, Japanese Patent Application Laid-Open No. Sho 63-303258. The electronic control is performed in response to wheel slip. There are prior arts described in JP-B-53-24687 and JP-B-57-2949.

[Problems to be solved by the invention]

By the way, in a vehicle that is subjected to ABS control at the time of a brake operation, the brake pressure is repeatedly increased and decreased to prevent wheel lock, so that the wheel rotation speed increases and decreases in a short cycle. This means that the vehicle speed signal (revolution speed signal of the secondary pulley), which is the shift condition of the continuously variable transmission, increases and decreases in a short cycle, and the continuously variable transmission repeats the downshift and the upshift insignificantly. It becomes unstable. If such a state is left unattended, not only is the delay in performing the return control to the normal speed ratio when the brake is released, but also the line pressure of the hydraulic control system is reduced and the secondary pressure is reduced, causing the drive belt to slip. Inconveniences such as wear and tear are expected. However, if the normal gear ratio control is switched to the shift control corresponding to the ABS operation at the time of the ABS operation, the above problem can be solved. However, in this case, how to determine the ABS operation is a problem. That is, in the ABS using only the hydraulic control system, it is not possible to take out the ABS operation time as an electronic signal, and it is expected that even with the electronic control type ABS, the ABS operation signal cannot be taken out due to some failure. Therefore, the present invention provides a continuously variable transmission that employs ABS
It is an object of the present invention to make it possible to determine the operation of the vehicle and to surely switch to the shift control corresponding to the operation of the ABS.

[Means for Solving the Problems]

For this purpose, the present invention provides an ABS control unit from the ABS control unit.
In a shift control device of a continuously variable transmission mounted on a vehicle having an antilock brake system that performs ABS control by a control signal, the shift control device inputs a rotation speed signal of a secondary pulley and performs a predetermined shift. A control unit that outputs a control signal, wherein the control unit includes:
A secondary pulley rotation speed change speed calculation unit that inputs a rotation speed signal of the secondary pulley and calculates the change speed thereof,
An ABS operation determination unit that outputs an ABS operation determination signal regardless of the presence or absence of the ABS control signal when a change speed signal from the secondary pulley rotation speed change speed calculation unit exceeds a predetermined value. It is assumed that. Here, the ABS operation determining unit detects the longitudinal acceleration of the vehicle body in addition to the secondary pulley rotation speed changing speed calculating unit.
A signal may be input from the sensor, and the ABS operation determination signal may be output when the change speed signal from the secondary pulley rotation speed change speed calculation unit exceeds a predetermined value and the detection signal from the G sensor is equal to or less than the predetermined value. Good.

[Action]

In such a means, on the shift control device side of the continuously variable transmission, the secondary pulley rotation speed change speed calculation unit of the control unit constantly outputs the change speed signal to the ABS operation determination unit, and based on this change speed signal. ABS operation judgment unit is ABS
The operation time is determined. Therefore, when the ABS control is performed by the brake operation of the vehicle, the change speed signal from the secondary pulley rotation speed change speed calculation unit exceeds a predetermined value, and the ABS operation determination unit outputs the ABS operation determination signal and outputs the ABS operation determination signal. Is determined. For this reason, even when the ABS operation signal is not input from the ABS side, switching to the shift control corresponding to the ABS operation is performed reliably.

【Example】

Hereinafter, an embodiment of the present invention will be specifically described with reference to the accompanying drawings. First, the outline of the drive system of a continuously variable transmission with a lock-up torque converter will be described with reference to FIG. 1. In the figure, reference numeral 1 denotes an engine, and a crankshaft 2
The transmission is sequentially transmitted to the forward / reverse switching device 4, the continuously variable transmission 5, and the differential device 6. In the torque converter device 3, a drive plate 10 connected to the crankshaft 2 is connected to a pump impeller 12 a of a torque converter 12 via a converter cover 11. The turbine runner 12b of the torque converter 12 is connected to the turbine shaft 13, and the stator 12c is connected to the one-way clutch 14
Guided by A lock-up clutch 15 integrated with the turbine runner 12b is installed so as to be able to engage or disengage with the drive plate 10, and engine power is transmitted via the torque converter 12 or the lock-up clutch 15. The forward / reverse switching device 4 is a double pinion type planetary gear
The sun gear 16a is input from the turbine shaft 13 and is output from the carrier 16b to the primary shaft 20. And a forward clutch between the sun gear 16a and the carrier 16b.
The planetary gear 16 is integrated with the engagement to directly connect the turbine shaft 13 and the primary shaft 20. Further, a reverse brake 18 is provided between the ring gear 16c and the case, and outputs reverse power to the primary shaft 20 by the engagement. And forward clutch 17 and reverse brake 18
Release the planetary gear 16. The continuously variable transmission 5 includes a primary pulley 22 of a variable pulley interval having a primary cylinder 21 on a primary shaft 20 as an input shaft, and a similar secondary pulley 25 having a secondary cylinder 24 on a secondary shaft 23 as an output shaft. The drive belt 26 is provided between the primary pulley 22 and the secondary pulley 25. Here, the primary cylinder 21 is the secondary cylinder
The pressure receiving area is set larger than that of the primary pulley 24, and the ratio of the winding radius of the drive belt 26 to the primary pulley 22 and the secondary pulley 25 is changed by the primary pressure to perform stepless transmission. In the differential device 6, an output shaft 28 is connected to the secondary shaft 23 via a pair of reduction gears 27,
The drive gear 29 of the output shaft 28 meshes with the final gear 30. A differential gear 31 connected to the final gear 30 is connected to left and right wheels 33 via an axle 32. On the other hand, an oil pump 34 is provided adjacent to the torque converter 12 in order to obtain a hydraulic pressure source for controlling the continuously variable transmission 5. The oil pump 34 is connected to the converter cover 11 by a pump drive shaft 35, and is constantly driven by engine power to generate hydraulic pressure. Here, since the control oil pressure of the continuously variable transmission 5 has a wide range of height, the oil pump 34 is, for example, of a roller vane type and of a variable displacement type having a plurality of sets of suction and discharge ports. Next, the hydraulic control system of the continuously variable transmission 5 will be described. An oil passage 41 from the oil pump 34 communicating with the oil pan 40 communicates with a secondary control valve 50 to generate a predetermined secondary pressure Ps. The pressure Ps is always supplied to the secondary cylinder 24 through the oil passage 42. The secondary pressure Ps is guided to the primary control valve 55 via the oil passage 43, where a predetermined primary pressure Pp is generated to supply and discharge oil to and from the primary cylinder 21 via the oil passage 44. The secondary control valve 50 is of a proportional electromagnetic relief valve type, and the control unit 70 of the continuously variable transmission 5 is connected to the proportional solenoid 51.
Supplies the solenoid current Is. Then, the electromagnetic force generated by the solenoid current Is acts on the spool against the hydraulic reaction force and the spring force of the secondary pressure Ps,
Adjust the pressure with these balances. That is, the set pressure is made variable by the solenoid current Is, and the secondary pressure Ps is controlled in a one-to-one proportional relationship with the solenoid current Is. The primary control valve 55 is of a proportional electromagnetic pressure reducing valve type, and a solenoid current Ip is supplied from the control unit 70 to the proportional solenoid 56, similarly to the secondary control valve 50. Then, the electromagnetic force caused by the solenoid current Ip acts on the spool against the hydraulic reaction force and the spring force of the primary pressure Pp,
The set pressure is made variable by the solenoid current Ip, and the primary pressure Pp is controlled in a one-to-one proportional relationship with the solenoid current Ip. The oil pump 34 is of a variable displacement type as described above, and a relatively high lubricating pressure is always generated in the oil passage 45 on the drain side of the secondary control valve 50. Therefore, the circuit is configured such that the lubricating pressure is supplied to the torque converter 12, the forward / reverse switching device 4, the lubricating portion of the drive belt 26 and the like. FIG. 2 shows a schematic configuration of the ABS. This is a type in which the brake pressure of the front and rear four wheels is electronically controlled by an ABS control unit 60, and a hydraulic unit 63 and a proportioning unit are provided in the middle of the brake hydraulic system from the master cylinder 61 to the wheel cylinders of each wheel 33. A valve 64 is interposed, and a wheel speed sensor 65 for detecting the rotation speed of each wheel 33 is installed. The ABS control unit 60 calculates the speed, acceleration / deceleration, estimated vehicle speed, and the like of each wheel 33 based on the detection signal of each wheel speed sensor 65. Then, comparing the estimated vehicle speed with the wheel speed, judging from the magnitude of acceleration / deceleration of the wheel, etc., the three hydraulic modes of pressure increase, hold, and pressure decrease are selected, and the selected predetermined ABS operation signal is transmitted to the hydraulic unit. Output to 63. Hydraulic unit 63 has four wheels 33
A plurality of solenoid valves 66 for adjusting hydraulic pressure are provided, and each solenoid valve 66 is controlled so as to increase, hold, and reduce the brake pressure in accordance with an ABS operation signal from the ABS control unit 60. The proportioning valve 64 is adapted to the left or right rear wheel 33 in accordance with the side of the left and right rear wheel 33 that is about to be locked.
At the same pressure. FIG. 3 shows an electronic control system of the proportional solenoids 51 and 56 in the hydraulic control system of the continuously variable transmission 5. This control system
As an input signal sensor of the control unit 70, a primary pulley rotation speed sensor 71, a secondary pulley rotation speed sensor 7
2, engine speed sensor 73, throttle opening sensor 74
And a pressure sensor 75 for detecting the secondary pressure Ps. Here, first, the control system of the proportional solenoid 51 for controlling the secondary pressure Ps will be described. The control unit 70 includes a throttle opening signal θ from the throttle opening sensor 74 and an engine speed signal Ne from the engine speed sensor 73.
Has an input engine torque calculation unit 76, and estimates the engine torque Te from the torque characteristic of θ-Ne. The engine 1 which is the input side of the torque converter 12
The rotation speed signal Ne and the rotation speed signal Np of the primary pulley 22, which is the output side, are input to the torque amplification ratio calculation unit 77, and the torque amplification ratio t according to the speed ratio n (Np / Ne) is determined. Further, the engine speed signal Ne and the primary pulley speed signal Np are input to a primary system inertia force calculation unit 78, and the inertia force gi is calculated from the mass and acceleration of the engine 1 and the primary pulley 22. And these engine torque Te, torque amplification rate t,
The signal of the inertia force gi is input to the input torque calculator 79, and the input torque Ti of the continuously variable transmission 5 is calculated as follows. Ti = Te · t-gi On the other hand, the actual speed ratio i (Np
/ Ns), and a required secondary pressure setting unit 80 that receives the actual speed ratio signal i and sets the required secondary pressure Psu. Here, each actual gear ratio i
The secondary pressure Psu at the slip limit required for unit torque transmission is set for each time as shown in FIG. 4 (a), and the required secondary pressure Psu according to the actual speed ratio i is determined from this map. Then, the input torque Ti, the signal of the required secondary pressure Psu, and the rotation speed signal Ns of the secondary pulley 25 are input to the target secondary pressure calculation unit 81, and the target secondary pressure Pss considering the centrifugal hydraulic pressure gs of the secondary cylinder 24 is taken into account. Is calculated as follows. Pss = Ti · Psu−gs + PM Here, PM is a function of the actual gear ratio i, and PM = f (i)
And is called a margin. The target secondary pressure Pss is further adjusted by the solenoid current setting section 82.
To determine the solenoid current Is according to the target secondary pressure Pss. In this case, since the secondary control valve 50 has the characteristic of controlling the secondary pressure Ps in a proportional relation to the solenoid current Is as described above,
The solenoid current Is with respect to the target secondary pressure Pss is obtained in proportion to the map shown in FIG.
Then, this solenoid current Is is supplied to the proportional solenoid 51 of the secondary control valve 50 via the drive unit 83, and thus the secondary current Ps is directly controlled to follow the target secondary pressure Pss by the solenoid current Is. It has become. Subsequently, the proportional solenoid 56 for controlling the primary pressure Pp
Is described. First, as a basic concept of this control, since the actual speed ratio i in the steady state is determined by the hydraulic pressure ratio between the secondary pressure Ps and the primary pressure Pp, the hydraulic pressure ratio Kp (Pp / Ps)
Is expressed as the relationship of the actual gear ratio i, and Kp = f (i). On the other hand, in the relationship between the primary pulley 22 and the driving pulley 26, when the input torque Ti increases, for example, the shift shifts in the downshift direction, and it is understood that the input torque Ti affects the actual speed ratio i. Therefore, this input torque
In relation to the relationship between Ti and the actual gear ratio i, the torque ratio KT between the maximum torque (Ps / Psu) that can be transmitted at the current secondary pressure Ps and the input torque Ti of the current transmission torque is represented by KT = Ti / (Ps / Psu). Then, the current torque transmission state, that is, the actual speed ratio i in the relationship of the hydraulic ratio Kp is determined, whereby the hydraulic ratio Kp becomes Kp = f (i, KT) as the relationship between the actual speed ratio i and the torque ratio KT. Holds. Thus, the hydraulic pressure ratio Kp is determined by the actual gear ratio i and the torque ratio KT as shown in FIG.
Irrespective of the hydraulic pressure ratio Kp and the secondary pressure Ps, the required primary pressure P
PD is calculated. As a result, the current input torque at steady state
With respect to Ti, the primary pressure PPD required to maintain the current actual gear ratio i can be obtained for the secondary pressure Ps. Next, the shift control during the transition may be performed by controlling the flow rate according to a desired shift speed. Therefore, the pulley position change speed de / dt is calculated based on the shift speed or the pulley position based on the deviation between the target speed ratio is and the actual speed ratio i according to each driving and running condition. Where pulley position change speed d
Since e / dt is the volume change of the primary cylinder 21, that is, the flow rate, the opening area, that is, the valve displacement, is obtained using the equation of the valve flow rate, and the pulley position change speed is accordingly determined.
Convert to pressure Pp required to achieve de / dt. Then, the target primary pressure Pps is determined by adding or subtracting the pressure Pp to or from the required primary pressure PPD determined by the above-described hydraulic ratio control according to the upshift and the downshift. Therefore, based on the basic concept of the control, the control unit 70 has a hydraulic ratio control system and a flow control system. First, the hydraulic ratio control system will be described. The primary pulley rotation speed signal Np from the primary pulley rotation speed sensor 71 is described.
And an actual speed ratio calculating unit 85 that inputs the speed signal Ns from the secondary pulley frequency sensor 72 and calculates the actual speed ratio i (Np / Ns). On the other hand, there is provided a torque ratio calculating section 86 which receives the input torque Ti, the required secondary pressure Psu and the signal of the secondary pressure Ps of the pressure sensor 75 and calculates a torque ratio KT. The signal is input to the hydraulic pressure ratio setting unit 87, and the hydraulic pressure ratio Kp is determined based on the relationship between the torque ratio KT and the actual speed ratio i according to the map shown in FIG. The signals of the hydraulic pressure ratio Kp and the secondary pressure Ps are input to the required primary pressure calculation unit 88, and further, taking into consideration the centrifugal hydraulic pressure gp of the primary cylinder 21 portion based on the primary pulley rotation speed Np, the required primary pressure PPD is calculated as follows. calculate. PPD = Kp.Ps-gp Next, the flow rate control system will be described. The target primary pulley rotation speed search unit 89 for inputting the signal of the actual gear ratio i and the throttle opening signal θ is provided. The pulley rotation speed NPD is determined. The target primary pulley rotation speed NPD and the secondary pulley rotation speed Ns
Is input to the target gear ratio calculator 90, and the target gear ratio is
Is calculated from is = NPD / Ns. Thus, the target gear ratio is determined according to each driving and running condition based on the gear shift pattern. Here, the oil amount V of the primary cylinder 21 is proportional to the actual pulley position e, and the flow rate Q obtained by differentiating the oil amount V with time corresponds to the pulley position change speed de / dt on a one-to-one basis. Therefore, since the flow rate Q is preferably calculated as it is from the pulley position change speed de / dt, the actual speed ratio i and the target speed ratio is determined by the actual pulley position conversion unit 91 and the target pulley position conversion unit 92. Convert to target pulley position es. The actual pulley position e and the target pulley position es are input to the pulley position change speed calculation unit 93, and the pulley position conversion speed de / dt is calculated as
It is calculated from the deviation between the actual pulley position e and the target pulley position es as described below. de / dt = K1 · (es−e) · K2 · des / dt (K1, K2: constant, des / dt: phase advance element) The pulley position change speed de / dt is input to the shift pressure calculation unit 94, The pressure ΔPp required for shifting is obtained based on the flow rate based on the pulley position change speed de / dt. Thus, the required primary pressure PPD of the hydraulic pressure ratio control system and the shift pressure ΔPp of the flow rate control system are equal to the target primary pressure calculation unit 95.
To calculate the target primary pressure Pps according to Pps + PPD + ΔPp at the time of an upshift, and Pps = PPD−ΔPp at the time of a downshift. And the calculated target primary pressure Pp
s is further input to a solenoid current setting unit 96, and a solenoid current Ip corresponding to the target primary pressure Pps is determined.
In this case, since the primary control valve 55 has the characteristic of controlling the primary pressure Pp in a proportional relationship with the solenoid current Ip as described above, the target primary pressure Pps in the map of FIG. Is obtained for the solenoid current Ip. The solenoid current Ip is supplied as a speed ratio control signal to the proportional solenoid 56 of the primary control valve 55 via the drive unit 97, and the speed is controlled by feedforward. Here, in order to determine the time of ABS operation, in order to perform appropriate shift control corresponding to the ABS operation, the control unit 70 includes a secondary pulley rotation speed change speed calculation unit 100, an ABS operation determination unit 101, and a control unit. Signal holding unit 102 and output switching unit 10
3 is provided. The secondary pulley rotation speed change speed calculation unit 100 receives the secondary pulley frequency signal Ns from the secondary pulley rotation speed sensor 72 and calculates the change speed (dNs / dt). Further, the ABS operation determination unit 101 receives the change speed signal dNs / dt from the secondary pulley rotation speed change speed calculation unit 100, and when the change speed signal dNs / dt exceeds a predetermined value, determines that it is the time of the ABS operation and determines the ABS operation. The signal As is output. Further, the control signal hold unit 102 includes an ABS operation determination unit 101
From the ABS operation determination signal As, the signal of the solenoid current Ip as a gear ratio control signal is input, and the signal level of the solenoid current Ip when the ABS operation determination signal As is input is held as a hold signal Iph, This is the ABS operation judgment signal
Output is performed until the input of As stops. The output switching unit 103 is configured to input the signal of the solenoid current Ip and the hold signal Iph held by the control signal holding unit 102 so as to input the solenoid current setting unit 9.
6 and the drive unit 97, and the solenoid current Ip
The hold signal Iph is output in preference to the signal of. Next, the operation of the shift control device for a continuously variable transmission having the above configuration will be described. First, the oil pump 34 is driven from the converter cover 11 of the torque converter device 3 via the rear drive shaft 35 by the operation of the engine 1, and the pump oil pressure is guided to the secondary control valve 50. Here, a description will be given of a normal traveling of a vehicle in which the ABS control is not performed. When the vehicle stops, the target speed ratio is and the actual speed ratio i of the primary control system are set as the maximum speed ratio on the mechanism of the continuously variable transmission 5, for example. Set to a value greater than 2.5. Therefore, the target primary pressure Pps according to the actual speed ratio i, the torque ratio KT, the hydraulic ratio Kp, and the secondary pressure Ps is calculated, and the solenoid current Ip corresponding to the target primary pressure Pps is output via the output switching unit 103 and the driving unit 97. It is supplied to the proportional solenoid 56 of the primary control valve 55. Thus the primary cylinder
21 operates on the oil drain side, and the primary pressure Pp becomes the lowest level. Therefore, all of the secondary pressure Ps by the secondary control valve 50 is supplied only to the secondary cylinder 24, and the continuously variable transmission 5 is in the low speed stage with the maximum speed ratio at which the drive belt 26 is shifted to the secondary pulley 25 most. At this time, the lock-up clutch 15 is released by a hydraulic control system (not shown), and the torque converter 12 is supplied with oil. Therefore, for example, when shifting to the drive range, the forward clutch 17 of the forward / reverse switching device 4 is engaged by refueling to be in the forward position. For this reason, the power of the engine 1 is input to the primary shaft 20 of the continuously variable transmission 5 via the torque converter 12 and the forward / reverse switching device 4, and the primary pulley 22
Then, power of the maximum speed ratio is output to the secondary shaft 23 via the drive belt 26 and the secondary pulley 25, and this power is transmitted to the wheels 33 via the differential device 6 to be able to start. In the secondary pressure control system, the engine torque Te is always estimated, and the torque amplification factor t and the primary system inertia force gi are calculated. Therefore, when starting the accelerator step,
Input torque Ti according to engine torque Te and torque amplification factor t
And the required secondary pressure Psu also increases, so that the target secondary pressure Pss becomes a large value. Then, the solenoid current Is having a low value corresponding to the target secondary pressure Pss is supplied to the proportional solenoid 51 of the secondary control valve 50 via the drive unit 83, so that the secondary pressure Ps is controlled to be high by reducing the drain amount. After starting, the gearshift is controlled and the lock-up clutch is
15 is engaged, the torque amplification factor t becomes 1, the required secondary pressure Psu decreases in accordance with the actual gear ratio i, and when the engine torque Te is reduced with increasing vehicle speed, the target secondary pressure Psu is reduced.
Pss decreases rapidly. Therefore, the solenoid current Is
Increases rapidly, the set pressure of the secondary control valve 50 gradually decreases, and the secondary pressure Ps is controlled to decrease. Here, the characteristics of the secondary pressure Ps are summarized as shown in FIG. 5 (a), and the optimal control is performed so as to always secure the minimum pulley pressing force that does not cause belt slip with respect to the transmission torque. The secondary pressure Ps is guided to the primary control valve 55,
The primary pressure Pp is generated in the primary cylinder 21 by the pressure reducing action, and the speed is controlled by the primary pressure Pp.
This is described below. First, when the maximum speed ratio iL starts, the primary control valve 55 performs the maximum pressure reducing operation by the hydraulic ratio control system, and the primary pressure
Pp is kept at the lowest level. When the shift start condition of the target gear ratio is <2.5 is satisfied by the driving and running conditions, and the target gear ratio is set to be gradually smaller, the pulley position change speed de / dt is calculated by the flow control system. Accordingly, a shift pressure ΔPp is generated to increase the target primary pressure Pps. For this reason, the solenoid current Ip is gradually reduced, the set pressure of the primary control valve 55 is increased by the electromagnetic force of the proportional solenoid 56, and the primary pressure Pp is controlled to be sequentially increased. Then, the drive belt 26 moves to the primary pulley 22 and
Upshift to a higher gear with a smaller gear ratio. When the actual speed ratio i decreases due to the shift control, the hydraulic ratio Kp is increased by the hydraulic ratio setting unit 87 of the hydraulic ratio control system,
The ratio of the required primary pressure PPD to the secondary pressure Ps is increased. The target primary pressure Pps increases due to the increase in the required primary pressure PPD, and the level of the primary pressure Pp is maintained at an increased level. Thus, each time the actual gear ratio i decreases due to the upshift, the hydraulic gear ratio control system controls the actual gear ratio i. The primary pressure Pp is sequentially controlled to increase to a level that maintains i. Further, when the input torque Ti increases, for example, the torque ratio KT becomes a large value in the torque ratio calculating section 86, thereby increasing the value of the hydraulic pressure ratio Kp. Therefore, the primary pressure Pp is corrected to increase, and is corrected so as to prevent the downshift tendency by increasing the input torque Ti. When the target speed ratio is reaches the minimum speed ratio iH (for example, 0.5) and the target primary pressure Pps is set to the highest level, the solenoid current Ip becomes the smallest and the set pressure of the primary control valve 55 becomes the maximum. As a result, the primary pressure Pp is controlled to the maximum. At this time,
When the actual speed ratio i also reaches the minimum speed ratio iH following the target speed ratio is, thereafter, the target primary pressure Pps is set to the highest level by the hydraulic ratio Kp of the hydraulic ratio control system and the required primary pressure PPD, and The pressure Pp is kept high and keeps the minimum shift iH. On the other hand, when the value of the target speed ratio is increases due to depression of the accelerator, a decrease in the vehicle speed, or the like, the target primary pressure Pps becomes a low level due to the subtraction of the shift pressure ΔPp. For this reason,
On the contrary, the solenoid current Ip increases and the primary control valve 55
, The primary pressure Pp is controlled to a low level by the pressure reduction.
Shift to and downshift. Also in the case of this downshift, the hydraulic ratio control system controls the hydraulic ratio according to the increase of the actual gear ratio i.
Kp, target primary pressure Pps by required primary pressure PPD
Is decreased, and the primary pressure Pp is sequentially controlled to decrease to a level necessary to maintain the actual speed ratio i. In this way, the primary pressure Pp is made variable by the hydraulic ratio control system and the flow rate control system over the entire shift range of the maximum speed ratio iL and the minimum speed ratio iH as shown in FIG. The shift is controlled by shifting. Next, a description will be given of shift control in the case where ABS control is performed by a brake operation of the vehicle. The ABS control unit 60 of the ABS control system calculates the speed, acceleration / deceleration, estimated vehicle speed, and the like of each wheel 33 based on the detection signal of each wheel speed sensor 65. Therefore, when sudden braking is applied, the wheels 33 decelerate and the ABS control unit 60
ABS control is started based on the determination of. That is, the ABS control unit 60 outputs an ABS operation signal to the hydraulic unit 63 so that the slip ratio of the wheel 33 falls within the appropriate range. Then, based on the ABS operation signal, each solenoid valve 66 in the hydraulic unit 63 appropriately controls the brake pressure of each wheel 33 to three hydraulic modes of increasing, holding, and reducing the pressure. Thus, the vehicle has sufficient braking force. And steerability. Here, when the ABS control is performed, the brake pressure of each wheel 33 is repeatedly increased and decreased, so that the wheel speed rapidly increases and decreases,
Rotational speed of secondary pulley 25 transmitted to wheels 33
Ns also increases and decreases rapidly. Therefore, the continuously variable transmission 5
The control unit 70 that performs electronic control of the change speed signal dNs / dt from the secondary pulley rotation speed change speed calculation unit 100
Rapidly increases and exceeds a predetermined value. For this reason, the ABS operation determination unit 101 determines that the ABS is operating and determines whether the ABS operation has been performed.
Is output to the control signal holding unit 102. Upon receiving the ABS operation determination signal As, the control signal hold unit 102 holds the gear ratio control signal at the time of the input of the ABS operation determination signal As, that is, the signal level of the solenoid current Ip. Solenoid current Ip
The signal is output from the output switching unit 103 to the driving unit 97 in preference to this signal. Therefore, when the ABS control is performed, the above-described normal speed ratio control is temporarily suspended, and the actual speed ratio i is maintained so as to follow the target speed ratio is immediately before the ABS operation. Therefore, the meaningless shifting operation is not performed, and the primary pressure Pp and the secondary pressure Ps of the hydraulic control system are maintained at the predetermined values, so that the slip of the drive belt 26 is prevented. When the change speed signal dNs / dt from the secondary pulley rotation speed change speed calculation unit 100 falls within a predetermined value due to the release of the brake operation, the ABS operation determination unit 101 outputs the ABS operation determination signal As.
And the control signal hold unit 102 stops the output of the hold signal Iph, so that the output switching unit 103
Drives the solenoid current Ip as a gear ratio signal.
, And returns to normal speed ratio control. Therefore, when the brake operation is released, it is possible to quickly perform the return control from the actual gear ratio i at the time of the ABS operation to the normal target gear ratio is. Although one embodiment of the present invention has been described above, the configuration of the present invention is not limited to this embodiment. For example,
The ABS operation determination unit 101 also receives a signal from a G sensor that detects longitudinal acceleration of the vehicle body in addition to the secondary pulley rotation speed change speed calculation unit 100, and outputs a change speed signal dNs / from the secondary pulley rotation speed change speed calculation unit 100. The configuration may be such that the ABS operation determination signal As is output when dt exceeds a predetermined value and the detection signal from the G sensor is equal to or more than the predetermined value. By doing so, the accuracy of the ABS operation determination can be improved. In any case, in the present invention, since the ABS operation is determined on the control unit 70 side of the continuously variable transmission 5, the ABS operation signal cannot be extracted from the ABS control unit 60 due to some failure, or the ABS is not electronically controlled. ABS with hydraulic control
Even when the operation signal cannot be extracted, it is possible to reliably switch to the shift control corresponding to the ABS operation.

【The invention's effect】

As described above, according to the present invention, on the shift control device side of the continuously variable transmission, the secondary pulley rotation speed change speed calculation unit of the control unit constantly outputs a change speed signal to the ABS operation determination unit. AB based on speed signal
The S operation determining unit determines that the ABS is operating. Therefore, when the ABS control is performed by the brake operation of the vehicle, the change speed signal from the secondary pulley rotation speed change speed calculation unit exceeds a predetermined value, and the ABS operation determination unit outputs the ABS operation determination signal and outputs the ABS operation determination signal. Is determined. Therefore, even when the ABS operation signal is not input from the ABS side, it is possible to reliably switch to the shift control corresponding to the ABS operation.

[Brief description of the drawings]

FIG. 1 is a schematic overall configuration diagram of a shift control device of a continuously variable transmission according to an embodiment of the present invention, FIG. 2 is a schematic configuration diagram of an ABS, and FIG. 3 is an electronic control in a shift control device of a continuously variable transmission. FIG. 4 (a) is a relationship map diagram of the actual speed ratio i and the secondary pressure Psu, and FIG. 4 (b) is a solenoid current Is and a target secondary pressure Ps.
FIG. 4 (c) is a relationship map between the torque ratio KT and the hydraulic ratio Kp, FIG. 5 (a) is a characteristic diagram of the secondary pressure, and FIG. FIG. 6B is a diagram showing a shift pattern of the primary pressure. DESCRIPTION OF SYMBOLS 1 ... Engine, 2 ... Crankshaft, 3 ... Torque converter device, 4 ... Forward / reverse switching device, 5 ... Continuously variable transmission, 6 ... Differential device, 20 ... Primary shaft, 21 ... Primary Cylinder, 22: Primary pulley, 23: Secondary shaft, 24: Secondary cylinder, 25: Secondary pulley, 26: Drive belt, 33: Wheel, 34: Oil pump, 50: Secondary control valve, 51… Proportional solenoid, 55 …… Primary control valve, 56 …… Proportional solenoid, 60 …… ABS control unit, 61 …… Master cylinder, 63 …… Hydraulic unit, 64 …… Proportioning valve, 65 …… Wheel Speed sensor, 66 Solenoid valve, 70 Control unit, 71 Primary pulley rotation speed sensor, 72 Secondary pulley rotation speed sensor, 73 Engine speed sensor, 74: Throttle opening sensor, 75: Pressure sensor, 96: Solenoid current setting unit, 97: Drive unit, 100: Secondary pulley rotation speed change speed calculation unit, 101: ABS operation Judgment unit 102 Control signal hold unit 103 Output switching unit

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Claims (2)

(57) [Claims] 1. An ABS control signal from an ABS control unit.
In a shift control device of a continuously variable transmission mounted on a vehicle having an antilock brake system that performs ABS control, the shift control device inputs a rotation speed signal of a secondary pulley and outputs a predetermined shift control signal. A control unit that outputs a rotation speed signal of the secondary pulley, and calculates a change speed of the secondary pulley rotation speed by inputting a rotation speed signal of the secondary pulley; and a secondary pulley rotation speed change speed calculation unit. An ABS operation determination unit that outputs an ABS operation determination signal regardless of the presence or absence of the ABS control signal when the change speed signal exceeds a predetermined value. . The ABS operation determining unit receives a signal from a G sensor for detecting longitudinal acceleration of the vehicle body in addition to a secondary pulley rotation speed change speed calculation unit, and outputs a change speed signal from the secondary pulley rotation speed change speed calculation unit. 2. A transmission control device for a continuously variable transmission according to claim 1, wherein an ABS operation determination signal is output when a value exceeds a predetermined value and a detection signal from the G sensor is equal to or less than the predetermined value. .