JPH06185603A - Transmission controller of continuously variable transmission - Google Patents

Abstract

PURPOSE:To suppress a heat generation quantity of a hydraulic startup clutch so as to extend the service life of the clutch by setting a speed change ratio target value for increasing the speed change ratio in a control mode in which engine torque becomes large, in a belt driving type continously variable transmission. CONSTITUTION:Various kinds of detection signal consisting of the throttle opening detection signal of a carburetor, an engine rotational speed signal, a vehicle speed signal, a brake signal, a shift lever position signal, etc., are input in an ECU 82 during operation of a vehicle, and the operational condition is detected based on these input signals, and a primary pressure control valve 34 serving as a speed change control valve is controlled in response to the detected result. Consequently, respective movable pulley pieces 8, 12 of a driving side pulley 4 and a driven side pulley 10 are shifted in the axial direction, so as to change effective radil of the respective pulley 4, 10 so that the speed change ratio may be varied. Then, in the case of a control mode for increasing engine torque, for example, snow mode, a speed change target value is set for increasing the speed change ratio. Consequently, heat generating force of hydraulic startup torque 62 is suppressed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a speed change control device for a continuously variable transmission, and more particularly, to both pulley portion pieces of a fixed pulley portion piece and a movable pulley portion piece that is attached to and detachable from the fixed pulley portion piece. The present invention relates to a shift control device for a continuously variable transmission that changes the gear ratio by decreasing the groove width between the pulleys and increasing or decreasing the radius of gyration of a belt wound around both pulleys.

[0002]

2. Description of the Related Art In a vehicle, a transmission is interposed between an internal combustion engine and driving wheels. This transmission system changes the driving force of the drive wheels and the traveling speed in accordance with the traveling condition of the vehicle that changes in a wide range, and makes the internal combustion engine fully exhibit its performance. The transmission is formed between both pulley part pieces of a pulley having a fixed pulley part piece fixed to the rotary shaft and a movable pulley part piece mounted on the rotary shaft so as to be able to come into contact with and separate from the fixed pulley part piece. There is a continuously variable transmission that changes the gear ratio (belt ratio) by increasing or decreasing the radius of rotation of a belt wound around a pulley by increasing or decreasing the width of a groove to transmit power.

Further, as a belt ratio control device for a continuously variable transmission, as disclosed in, for example, Japanese Patent Application Laid-Open No. 2-150555, it is set by the throttle opening when starting on a road surface having a small road surface friction coefficient. Some have provided a control means for controlling the belt ratio so as to obtain the target belt ratio value.

[0004]

By the way, the conventional shift control device for a continuously variable transmission has a snow mode SNOW.
Some have MODE, this snow mode SNO
The W MODE controls the gear ratio RATC to an intermediate ratio in the normal start mode NST to easily start on a snowy road, a frozen road surface or muddy ground.

In addition, another gear change control device for a continuously variable transmission has a gear ratio RATC even in a mode other than the snow mode SNOW MODE, that is, in a normal normal start mode NST.
There is one that improves the starting feeling by controlling the intermediate ratio.

As shown in FIG. 9, the gear ratio target value RATSP in the case where the above-described shift control device for a continuously variable transmission is controlled, becomes smaller as the throttle opening THR becomes larger.

For this reason, not only a sufficient driving force cannot be obtained, but also the temperature of the hydraulic starting clutch rises sharply, that is, the amount of heat generated becomes large, which deteriorates the durability of the hydraulic starting clutch and causes the transmission The oil ATF is deteriorated, which is disadvantageous in practical use.

Further, since the temperature rise of the hydraulic starting clutch lowers the friction coefficient of the hydraulic starting clutch, the control of the hydraulic starting clutch is deteriorated, and there are inconveniences such as a rapid increase in engine rotation and a long starting time. I was invited.

[0009]

Therefore, in order to eliminate the above-mentioned inconvenience, the present invention provides both pulley portions of a fixed pulley portion piece and a movable pulley portion piece attached to and detachable from the fixed pulley portion piece. In a shift control device for a continuously variable transmission, in which a gear width is controlled to change a gear ratio by increasing / decreasing a groove width between the pieces to increase / decrease a radius of gyration of a belt wound around the pulleys, a control mode in which an engine torque becomes large In this case, a control unit is provided which sets a gear ratio target value to increase the gear ratio and suppresses the heat generation amount of the hydraulic starting clutch.

[0010]

As a result of the invention as described above, when the control mode in which the engine torque becomes large is set, the control unit sets the gear ratio target value so as to increase the gear ratio, and the heat generation amount of the hydraulic starting clutch is set. Is suppressed and the service life of the hydraulic starting clutch is extended.

[0011]

Embodiments of the present invention will be described in detail below with reference to the drawings.

1 to 6 show an embodiment of the present invention. In FIG. 2, 2 is a belt drive type continuously variable transmission, 2 A is a belt, 4 is a drive side pulley, 6 is a drive side fixed pulley part piece, 8 is a drive side movable pulley part piece, 10 is a driven side pulley, 12 Is a driven side fixed pulley section piece, and 14 is a driven side movable pulley section piece. As shown in FIG. 2, the drive side pulley 4 is mounted on the rotary shaft 16 such that the drive side fixed pulley portion 6 is fixed to the rotary shaft 16 and is movable in the axial direction of the rotary shaft 16 and is not rotatable. The drive side movable pulley part 8 is formed. In addition, the driven pulley 10 is also
Like the drive side pulley 4, it has a driven side fixed pulley section piece 12 and a driven side movable pulley section piece 14.

The drive side movable pulley portion piece 8 and the driven side movable pulley portion piece 14 have a first and a second housing 18, respectively.
20 are mounted respectively, and first and second hydraulic chambers 22 and 24 are respectively formed. At this time, in the second hydraulic chamber 24 on the driven side, a biasing means 26 including a spring or the like for biasing the second housing 20 in the expanding direction of the second hydraulic chamber 24 is provided.

An oil pump 28 is provided on the rotary shaft 16, and the oil pump 28 is connected to the first and second hydraulic chambers 2.
The first and second oil passages 30 and 32 communicate with Nos. 2 and 24, respectively, and a primary pressure control valve 34, which is a shift control valve for controlling the primary pressure that is the input shaft sheave pressure, is provided in the middle of the first oil passage 30. To do. In addition, a line pressure (generally 5 to 25 kg / cm ² ) is maintained at a constant pressure (3 to 4 kg / c) in the first oil passage 30 on the oil pump 28 side of the primary pressure control valve 34 by the third oil passage 36.
m ² ), the constant pressure control valve 38 for controlling the pressure is communicated, and the primary pressure control valve 34 is communicated with the first three-way solenoid valve 42 for primary pressure control by the fourth oil passage 40.

A line pressure control valve 44 having a relief valve function for controlling the line pressure which is a pump pressure is connected in the middle of the second oil passage 32 by a fifth oil passage 46, and a line pressure control valve 44 is connected to the line pressure control valve 44. The 6th oil passage 48 connects the 2nd three-way solenoid valve 50 for line pressure control.

Further, a seventh clutch pressure control valve 52 for controlling the clutch pressure is provided in the middle of the second oil passage 32 closer to the second hydraulic chamber 24 than the communicating portion of the line pressure control valve 44.
The clutch pressure control valve 5 communicates with the oil passage 54.
A third three-way solenoid valve 58 for controlling the clutch pressure is connected to the second valve 8 by an eighth oil passage 56.

The primary pressure control valve 34, the primary pressure control first three-way solenoid valve 42, and the constant pressure control valve 3 are also provided.
The eighth oil passage 48, the sixth oil passage 48, the line pressure control second three-way solenoid valve 50, and the clutch pressure control valve 52 are connected by the ninth oil passage 60, respectively.

The clutch pressure control valve 52 is connected to the hydraulic starting clutch 62 by a tenth oil passage 64, and a pressure sensor 68 is connected in the middle of the tenth oil passage 64 by an eleventh oil passage 66. The pressure sensor 68 can directly detect the hydraulic pressure when controlling the clutch pressure in the hold and start modes, and contributes to commanding the detected hydraulic pressure to be the target clutch pressure. Further, since the clutch pressure becomes equal to the line pressure in the drive mode, it also contributes to the line pressure control.

An input shaft rotation detection gear 70 is provided outside the first housing 18, and a first rotation detector 72 on the input shaft side is provided in the vicinity of the outer peripheral portion of the input shaft rotation detection gear 70.
An output shaft rotation detection gear 74 is provided outside the second housing 20, and a second rotation detector 76 on the output shaft side is provided near the outer peripheral portion of the output shaft rotation detection gear 74. Then, the detection signals of the first rotation detector 72 and the second rotation detector 76 are output to the control unit 82, which will be described later, to grasp the engine speed and the belt ratio.

An output transmission gear 78 is provided on the hydraulic starting clutch 62, and a third rotation detector 80 for detecting the rotation of the final output shaft is provided near the outer peripheral portion of the gear 78. That is, the third rotation detector 80 is a reduction gear and a differential gear,
The rotation of the final output shaft directly connected to the drive shaft and the tire is detected, and the vehicle speed can be detected. Also, the second
The rotation detector 76 and the third rotation detector 80 can also detect the rotation around the hydraulic start clutch 62, which contributes to the detection of the clutch slip amount.

Further, various conditions such as a throttle opening of a carburetor (not shown) of the vehicle, engine rotations from the first to third rotation detectors 72, 76 and 80, vehicle speed, etc. are input to change the duty ratio and shift control. A control section 82 for performing the above is provided, and by this control section 82, the first three-way solenoid valve 42 for primary pressure control and the constant pressure control valve 38, the second three-way solenoid valve 50 for line pressure control, and the third three-way solenoid for clutch pressure control are provided. It is configured to control the opening / closing operation of the valve 58 and also control the pressure sensor 68.

Further, the various signals input to the control unit 82 and the functions of the input signals will be described in detail as follows: Shift lever position detection signal ... P, R, N, D,
Line pressure and ratio required by each range signal such as L, clutch control, throttle opening detection signal ...... Engine torque is detected from the memory input in the program in advance, target ratio or target engine speed The driver demand switch (DDTSW) signal ...... The driver's will is detected by the accelerator pedal depression state, and the control method during running or starting is determined. Accelerator pedal signal ...... Depending on the accelerator pedal depression state Detects the driver's will and determines the control direction when driving or starting, brake signal …… Detects the presence or absence of the brake pedal depressing operation, determines the control direction such as clutch disengagement, power mode option signal …… Vehicle To make the performance of the car sporty (or economical) There is a use such as emissions.

The torsional vibration system model shown in FIG. 3 will be described below.

From FIG. 3, I _E · dθe / dt = T _E −T _C / i _B ∴T _C = i _B (T _E −I _E · d θe / dt) I _E : Engine inertia θe: Engine speed N
E T _E: engine torque [theta] s: the clutch input rotational speed (NC2) _{T C:} clutch capacity .theta.c: clutch output rotational speed (NCO) _{i B:} speed ratio ratC I _R: negative圧慣resistance becomes, the larger the gear ratio RATCi _B A large clutch capacity T _C is obtained, and a large driving force can be obtained.

Further, the heat generation amount Q of the hydraulic starting clutch at the time of starting is calculated by the following equation when the starting control is started at t = 0 sec and ended at t = tc.

[Equation 1] And T _C = i _B (T _E −I _E · dθe / d
t) and θs = (1 / i _B ) · θe, the heat generation amount Q of the hydraulic starting clutch is

[Equation 2] Becomes

Therefore, the clutch input speed (NC2) θ
In s> clutch output speed (NCO) θc, the larger the gear ratio RATCi _B , the smaller the heat generation amount Q,
The longer the start control time is, or the engine torque T _E
Is larger, the heat generation amount Q is larger.

On the drive side of the hydraulic starting clutch, i _B · _IE · dθs / dt = i _B · T _E −T _C ∴d θs / dt = (1 / i _B · _IE ) · (i _B · T _E
-T _C), and the hydraulic starting clutch at the driven _{side, I R · dθc / dt =} T C -T R ∴dθc / dt = (1 / I R) · (T C -T R) T R: Load Clutch input speed (NC2) θs, clutch output speed (NCO) θc when initial values are θsο and θco
_{Is, θs = θSο + (1 /} i B · I E) · (i B · T E -T C) θc = θcο + (1 / I R) · (T C -T R) becomes, where, t = tc in the case of a _{θs = θc, θsο + (1} / i B · I E) · (i B · T E -T C) tc = θcο + (1 / I R) · (T C -T R) tc becomes , So that the time tc is

[Equation 3] Becomes

Further, since T _C = i _B (T _E −I _E · dθe / dt) holds during start control, the time tc is

[Equation 4] Becomes

[0029] Furthermore, the start control at the time, since the fluctuation of the clutch output rotational speed (NCO) .theta.c is small, when dθe / dt = 0, the time _{tc, ∴tc = (I R /} i B · T E - T _R) · (θsο-θc
ο) Therefore, the time tc becomes shorter as the gear ratio RATCi _B becomes larger.

From this, the conclusion can be obtained. The smaller the gear ratio RATC, the larger the amount of heat generated by the hydraulic starting clutch. The smaller the gear ratio RATC, the longer the starting control. The longer the starting control is, the more the amount of heat generated by the hydraulic starting clutch is. The larger the engine torque, the larger the amount of heat generated by the hydraulic starting clutch.

From this conclusion, the heat generation amount Q of the hydraulic starting clutch increases rapidly when the engine torque is large and the gear ratio RATC is low.

Therefore, according to the present invention, the throttle opening THR determines the gear ratio target value RATSP so that the gear ratio RATC increases when the engine torque is large, and the heat generation amount Q of the hydraulic starting clutch is abnormally increased. To prevent.

The control section 82 has a structure for setting a gear ratio target value so as to increase the gear ratio when the engine torque becomes a control mode in which the engine torque is large, and suppressing the heat generation amount of the hydraulic starting clutch. ing.

More specifically, as shown in FIG. 4, the control unit 82 uses the detection signal of the throttle opening THR to determine the gear ratio target value from the f (THR) curve RATCV2 map (100) of the gear ratio target value RATSP. RATSP is calculated and the gear ratio target value RA during hold mode HLD
TSPH is the gear ratio target value RATSP (10
2).

As the gear ratio target value RATSP, any one of the above is used by the operation of the control mode switch SW (104) described later.

The control mode switch SW (1
Reference numeral 04) connects to the map (100) side in the control mode, that is, the normal start mode NST, and connects to the processing (102) side in the hold mode HLD.

Further, the gear ratio target value RA is obtained from the f (THR) curve RATCV1 map (106) of the gear ratio target value RATSP by the detection signal of the throttle opening THR.
Seeking TSP.

After that, the gear ratio target value RATSP is determined by the operation of the snow mode switch NOW MODESW (108).

The snow mode switch SNOW MO
The DE SW (108) is connected to the control mode switch (104) side in addition to the snow mode,
In the snow mode, it is connected to the f (THR) curve RATCV1 map (106) side.

Furthermore, the snow mode switch SNOW
The gear ratio target value RATSP determined by the MODE SW (108) is filtered (110), then an error from the gear ratio RATC is calculated (112), and the ratio solenoid duty OPW is determined by the PI control (114).
RAT is calculated and this ratio solenoid duty OP
Each solenoid valve is excited by the WRAT.

Reference numeral 84 is the hydraulic starting clutch 6
2 piston, 86 annular spring, 88 first pressure plate, 90 friction plate, 92 second
A pressure plate, 94 is an oil pan, and 96 is an oil filter.

Next, the operation will be described.

As shown in FIG. 2, the belt drive type continuously variable transmission 2 includes an oil pump 2 located on a rotary shaft 16.
8 operates in response to the drive of the rotary shaft 16, and the oil is absorbed from the oil pan 94 at the bottom of the transmission through the oil filter 96. The line pressure, which is the pump pressure, is controlled by the line pressure control valve 44. If the amount of leakage from the line pressure control valve 44, that is, the amount of escape of the line pressure control valve 44 is large, the line pressure becomes low, and conversely. If it is small, the line pressure will be high.

Further, the line pressure control valve 44 has a shift control characteristic for changing the line pressure in the full low state, the full over top state, and the fixed ratio state, and performing three-stage control.

The operation of the line pressure control valve 44 is controlled by a dedicated second three-way solenoid valve 50, and the line pressure control valve 44 operates following the operation of the second three-way solenoid valve 50. The second three-way solenoid valve 50 is controlled at a constant frequency duty ratio. That is, the duty ratio of 0% means a state in which the second three-way solenoid valve 50 does not operate at all, the output side is connected to the atmosphere side, and the output hydraulic pressure becomes zero.
Further, the duty ratio of 100% means that the second three-way solenoid valve 50 operates and the output side conducts to the output side, and the maximum output hydraulic pressure is the same as the control pressure, and the output hydraulic pressure is varied according to the duty ratio. Therefore, the characteristic of the second three-way solenoid valve 50 is substantially linear, and the line pressure control valve 44 can be operated in an analog manner.
The line pressure can be controlled by arbitrarily changing the duty ratio of. The operation of the second three-way solenoid valve 50 is controlled by the controller 82.

The primary pressure for shift control is controlled by the primary pressure control valve 34, and like the line pressure control valve 44, the operation of the primary pressure control valve 34 is controlled by a dedicated first three-way solenoid valve 42. ing. The first three-way solenoid valve 42 is used for conducting the primary pressure to the line pressure or for conducting the primary pressure to the atmosphere side, and conducting the line pressure to shift the belt ratio to the full overdrive side, or the atmosphere. It is made to conduct to the side and to shift to the full low side.

Clutch pressure control valve 5 for controlling the clutch pressure
No. 2 connects with the line pressure side when the maximum clutch pressure is required, and with the atmosphere side when the minimum clutch pressure is required. The clutch pressure control valve 52 is also the same as the line pressure control valve 44 and the primary pressure control valve 34.
The operation is controlled by the dedicated third three-way solenoid valve 58, and the description will be omitted. The clutch pressure varies within the range from the minimum atmospheric pressure (zero) to the maximum line pressure.

There are four basic patterns for controlling the clutch pressure, which will be described later. The basic patterns are (1), the neutral mode ... When the shift position is N or P and the clutch is completely disengaged, the clutch pressure is the minimum pressure. (Zero) (2) Hold mode ....... If the shift position is D or R and the throttle is released and there is no intention to run, or if you want to decelerate and cut the engine torque while running, the clutch pressure should be such that the clutch contacts. Low level (3), start mode ... When trying to connect the clutch again at the time of starting or after the clutch is disengaged, the clutch pressure prevents the engine from rising and the engine generated torque (clutch input torque) that allows the vehicle to operate smoothly. ) Appropriate level (4), drive mode ... Transition from complete driving state When the clutch is fully engaged, there are four clutch pressure levels, high enough to withstand the engine torque. The basic pattern (1) is performed by a dedicated switching valve (not shown) that is interlocked with the shift operation, and the other (2), (3), and (4) are the first to the first by the control unit 82.
The duty ratio control of the third three-way solenoid valves 42, 50, 58 is performed. Particularly in the state of (4), the clutch pressure control valve 52 causes the seventh oil passage 54 and the tenth oil passage 54 to
The maximum pressure generation state is established by communicating with the oil passage 64, and the clutch pressure becomes the same as the line pressure.

The primary pressure control valve 34, the line pressure control valve 44, and the clutch pressure control valve 52 are the first
The output pressures from the third to three-way solenoid valves 42, 50 and 58 are controlled respectively. The control pressures to control the first to third three-way solenoid valves 42, 50 and 58 are generated by the constant pressure control valve 38. It has a constant hydraulic pressure. This control oil pressure is always higher than the line pressure, but is a stable and constant pressure. The control oil pressure is also introduced to the control valves 34, 44, 52, and these control valves 34, 4
We are trying to stabilize 4, 52.

Next, the electronic control of the belt drive type continuously variable transmission 2 will be described.

The continuously variable transmission 2 is hydraulically controlled, and in response to a command from the control unit 82, an appropriate line pressure for holding the belt and transmitting torque, a primary pressure for changing the gear ratio, and a clutch. The respective clutch pressures for ensuring the engagement are secured.

A flow control flowchart for the belt drive type continuously variable transmission 2 will be described with reference to FIG.

First, the belt drive type continuously variable transmission 2
The control program is started (200) by driving.

Next, the snow mode switch SNOW M
Judgment of ON / OFF state of ODE SW (108) (20
2) is performed, and if it is off, it is determined whether the operating state of the vehicle is the normal start mode NST (204).

If this judgment (204) is YES, the map (10) for the f (THR) curve RATCV2 in FIG.
0), RATSP = RATCV (THR) is obtained (206), and if the judgment (204) is NO, it is judged whether the hold mode is HLD (208).

If the determination (208) is NO, the control shifts to another shift control (210) and returns (21
When the determination (208) is YES, the gear ratio target value RATESPH during the hold mode HLD is set to the gear ratio target value RATSP (212).

Based on the gear ratio target value RATSP from these processes (212) and (206), the control mode R
The ATMOD is set (214), the ratio solenoid duty OPWRAT is calculated (216), and the routine proceeds to return (218).

In the above judgment (202), the snow mode switch SNOW MODE SW (108)
When is on, it is judged whether the driving state of the vehicle is the normal start mode NST (220). When it is YES, RATSP = RATCV is determined by the map (106) for the f (THR) curve RATCV1 in FIG. (TH
R) is calculated (222), and if NO, it is determined whether the hold mode is HLD (224).

When the determination (224) is NO, the control shifts to another shift control (210) and returns (21
8), if the judgment (224) is YES, the process shown in FIG.
F (THR) curve RATCV1 map (106)
RATSP = RATCV (THR) is calculated by (2
22), the gear ratio target value RATSP from the process (222)
Control Mode RATED Set (2
14) is performed and the ratio solenoid duty OPWRA
After calculating T (216), the process proceeds to return (218).

As a result, it is possible to prevent the temperature of the hydraulic starting clutch from rising in the control mode in which the engine torque becomes large, for example, in the snow mode SNOW MODE, and the durability of the hydraulic starting clutch is ensured and the service life is shortened. It is advantageous in terms of practical use that it can be made longer and the maintenance cost can be made low, which is economically advantageous, the friction coefficient of the hydraulic starting clutch can be maintained, and the controllability of the hydraulic starting clutch can be secured.

Further, since it can be dealt with only by improving a part of the program in the control unit, the structure does not become complicated and does not become large in size, the manufacturing is easy, the cost can be kept low, and it is economical. Is advantageous to.

Further, even when the vehicle is started at a high throttle opening, a sufficient driving force can be quickly and reliably obtained, so that the starting performance can be improved, which is practically advantageous.

Furthermore, by preventing the temperature rise of the hydraulic starting clutch, deterioration of the transmission oil ATF can be prevented.

The present invention is not limited to the above-mentioned embodiment, but various application modifications are possible.

For example, in the above-described embodiment, the gear ratio target value RATSP is obtained by using the throttle opening THR as a variable, but it is also possible to obtain the gear ratio target value RATSP by using the torque generated by the engine as a variable.

[0066]

As described above in detail, according to the present invention, when the engine torque becomes large, the gear ratio target value is set so as to increase the gear ratio, and the heat of the hydraulic starting clutch is generated. Since the control unit for suppressing the amount is provided, it is possible to prevent the temperature of the hydraulic starting clutch from rising, and it is possible to secure the durability of the hydraulic starting clutch and prolong the service life, which is practically advantageous. Further, since it can be dealt with only by improving a part of the program in the control unit, the configuration is not complicated, the size is not increased, the manufacturing is easy, the cost can be kept low, and it is economically advantageous. is there. Further, even when the vehicle is started at a high throttle opening, sufficient driving force can be quickly and reliably obtained, so that the starting performance can be improved, which is practically advantageous.

[Brief description of drawings]

FIG. 1 is a flowchart for shift control of a belt drive type continuously variable transmission showing an embodiment of the present invention.

FIG. 2 is a schematic view of a belt drive type continuously variable transmission.

FIG. 3 is an explanatory view of a main part of a belt drive type continuously variable transmission.

FIG. 4 is a block diagram of a control unit of a belt drive type continuously variable transmission.

FIG. 5: Throttle opening THR and gear ratio target value RATS
It is a figure which shows the relationship with P.

[FIG. 6] Throttle opening THR and gear ratio target value RATS
It is a figure which shows the relationship with P.

FIG. 7 is a diagram showing an engine torque curve.

FIG. 8 is a time chart for shift control of the belt drive type continuously variable transmission.

FIG. 9 is a throttle opening T showing a conventional technique of the present invention.
It is a figure which shows the relationship between HR and gear ratio target value RATSP.

FIG. 10 is a time chart for shift control of the belt drive type continuously variable transmission.

[Explanation of symbols]

 2 Belt drive type continuously variable transmission 2A Belt 4 Drive side pulley 10 Driven side pulley 28 Oil pump 34 Primary pressure control valve 38 Constant pressure control valve 44 Line pressure control valve 52 Clutch pressure control valve 62 Hydraulic start clutch 68 Pressure sensor 82 Control Department

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[Procedure amendment]

[Submission date] May 19, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0025

[Correction method] Change

[Correction content]

Further, the heat generation amount Q of the hydraulic starting clutch at the time of starting is calculated by the following equation when the starting control is started at t = 0 sec and ended at t = tc.

[Equation 1] And T _C = i _B (T _E −I _E · dθe / d
The heat generation amount Q of the hydraulic starting clutch consisting of t) and θs = (1 / i _B ) · θe is

[Equation 2] Becomes

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0027

[Correction method] Change

[Correction content]

On the drive side of the hydraulic starting clutch, i _B · I _E · dθs / dt = i _B · T _E −T _C ∴d θs / dt = (1 / i _B << · _IE ) · (i _B・ T _E
-T _C), and the hydraulic starting clutch at the driven _{side, I R · dθc / dt =} T C -T R ∴dθc / dt = (1 / I R) · (T C -T R) T R: Load Shitaesuomikuron the initial value, the clutch input rotational speed in the case of a θcο (NC2) θs, the clutch output rotational speed (NCO) .theta.c is, θs = θsο + (1 / i B «· I E) · (i B · T E - _{T C) θc = θcο + (} 1 / I R) · (T C -T R) becomes, where if it becomes [theta] s = .theta.c at t = tc, θsο + (1 / i B «· I E) · (I _B · T _E −T _C ) tc = θco + (1 / I _R ) · (T _C −T _R ) tc, whereby the time tc becomes

[Equation 3] Becomes

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0028

[Correction method] Change

[Correction content]

Further, since T _C = i _B (T _E −I _E · dθe / dt) holds during start control, the time tc is

[Equation 4] Becomes

[Procedure amendment 4]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

[Correction content]

[Figure 3]

[Figure 4]

[Figure 5]

[Figure 6]

[Figure 7]

[Figure 9]

[Figure 1]

[Figure 8]

[Figure 10]

[Fig. 2]

Claims (1)

[Claims] Claim: What is claimed is: 1. A fixed pulley portion piece and a movable pulley portion piece attached to the fixed pulley portion piece so as to be able to come into contact with and separate from each other by increasing and decreasing the groove width between the pulley portion pieces. In a shift control device for a continuously variable transmission that performs shift control to change the gear ratio by increasing or decreasing the radius of gyration, when a control mode in which the engine torque is large is set, a gear ratio target value is set to increase the gear ratio. A shift control device for a continuously variable transmission, comprising: a control unit that sets and suppresses a heat generation amount of a hydraulic starting clutch.