JPH0820010B2 - Controller for continuously variable transmission - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a speed control device that controls a change speed of a gear ratio of a belt type continuously variable transmission for a vehicle by taking into account a load of an air conditioner. .

[Conventional technology]

Generally, a continuously variable transmission is usually controlled by a control device, and for example, there is a basic hydraulic control system disclosed in JP-A-55-65755. This is to set the gear ratio so that the gear ratio control valve is balanced by the factors of the accelerator depression amount and the engine speed, and the engine speed is always constant. To do.

In this case, the gear shift speed is mechanically determined by each gear ratio, primary pressure, etc., and the gear shift speed cannot be directly controlled. Therefore, in the case where the continuously variable transmission is shift-controlled so as not to deteriorate drivability due to hunting, overshoot, etc. in the gear ratio in the transient state of the driving range, the electronic control is performed in consideration of the speed of change of the gear ratio. Tend to do. Therefore, conventionally, as for the speed change control of the continuously variable transmission, there is, for example, the prior art of Japanese Patent Laid-Open No. 59-187153, in which a target speed ratio is set and the deviation between this and the actual speed ratio is controlled to be zero. Has been shown to do.

[Problems to be solved by the invention]

By the way, the target gear ratio in the above prior art is, for example, the engine output depending on factors such as throttle opening and vehicle speed,
That is, it is determined based on the transmission torque input to the continuously variable transmission, and it is premised that the engine output is directly input to the continuously variable transmission. Therefore, even when a part of the engine output is consumed by driving the compressor when the air conditioner is operating, running performance is inevitably deteriorated if the target gear ratio is determined and controlled as in the case where the air conditioner is not operating.

That is, in the method in which the shift speed di / dt is calculated based on the deviation between the target gear ratio and the actual gear ratio and the target shift speed is used for control, there is a deviation in the value of the shift speed di / dt itself. It has a great impact on the deterioration. For this reason, it is necessary to correct the required gear ratio in response to the reduction of the driving force due to the load amount of the air conditioner at the speed change speed during operation of the air conditioner.

The present invention has been made in view of such a point, and when the air conditioner is operating, it is possible to prevent deterioration of traveling performance by controlling the shift speed so as to increase the driving force by a required amount corresponding to the load of the air conditioner. It is an object of the present invention to provide a control device for a continuously variable transmission, which is a means for solving the above problems. A primary pulley and a secondary pulley with variable pulley gaps respectively provided on a drive wheel side auxiliary shaft arranged parallel to the main shaft, and a drive belt wound between both pulleys. In a continuously variable transmission that changes the ratio of the winding diameter of the drive belt to both pulleys by the hydraulic pressure supplied to each servo device to continuously change the speed, Line pressure control valve that controls the line pressure that is supplied to the secondary pulley servo device in the hydraulic circuit that communicates with each of the mari pulley and secondary pulley servo devices, and the operating hydraulic pressure of the primary pulley servo device that supplies and discharges the line pressure. A speed change control valve, a regulator valve that generates a constant hydraulic pressure by at least draining the line control valve, and a line that is provided in a constant hydraulic circuit and that generates a control hydraulic pressure according to an electric signal to act on the line pressure control valve. A solenoid valve for pressure control, a solenoid valve for shift control which is provided in a circuit of constant hydraulic pressure to generate a control hydraulic pressure according to an electric signal to act on a shift speed control valve, and at least a target gear ratio is determined to perform shift control. A control device, the control device having a correction coefficient according to upshift and downshift, and an air conditioner according to the load of the air conditioner. A correction amount calculation processing unit for calculating a correction amount of the shift speed based on the load correction amount is provided. Based on the correction amount of the shift speed, when the air conditioner is operating, the shift speed is small when the shift is up, and the shift down is small. In this case, the shift speed is increased.

[Action]

Based on the above configuration, when the air conditioner is not operating, the upshift and the downshift are controlled at the same gear shift speed, while when the air conditioner is operating, the downshift is faster when the accelerator pedal is depressed by the amount corresponding to the load amount. Then, the subsequent shift up also becomes slower according to the load of the air conditioner, and the increase of the driving force along with the engine speed is promoted. In this way, it is possible to appropriately improve the acceleration performance while appropriately supplementing the power for driving the compressor. It will be possible.

〔Example〕

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

First, referring to FIG. 2, an outline of a transmission system including a continuously variable transmission to which the present invention is applied will be described.
Is a continuously variable transmission 4 via a clutch 2 and a forward / reverse switching device 3.
Is connected to the main shaft 5. In the continuously variable transmission 4, the auxiliary shaft 6 is arranged in parallel with the main shaft 5, and the main shaft 5 has a primary pulley 7
However, the secondary shaft 6 is provided with a secondary pulley 8, and each of the pulleys 7 and 8 is equipped with a primary cylinder 9 and a secondary cylinder 10 which are hydraulic cylinders serving as a primary servo device and a secondary servo device on the movable side.
The drive belt 11 is wound around. Here, the primary cylinder 9 is set to have a larger pressure receiving area, and the primary pressure changes the ratio of the winding diameter of the drive belt 11 to the pulleys 7 and 8 for continuously variable transmission.

The auxiliary shaft 6 is connected to an output shaft 13 via a pair of reduction gears 12, and the output shaft 13 is configured to be transmitted to a drive wheel 16 via a final gear 14 and a differential gear 15.

Next, the hydraulic control system of the continuously variable transmission 4 will be described. The hydraulic pump has an oil pump 20 driven by the engine 1, and the line pressure oil passage 21 on the discharge side of the oil pump 20 has a secondary cylinder 10 and a line pressure control. Valve 22, shift speed control valve
It communicates with the primary cylinder 9 through the oil passage 24 from the transmission speed control valve 23. The line pressure oil passage 21 is further communicated with the regulator valve 25, and the oil passage 26 of constant regulator pressure from the regulator valve 25 is connected to the line pressure control solenoid valve 27, the shift control solenoid valve 28, and the shift speed control valve 23. Connect to one side. Each solenoid valve 27, 28 is, for example, turned on and discharged by a duty signal from the control unit 40, and turned off to output the regulator pressure PR, and generates such a pulsed control pressure. Then, the pulsed control pressure from the line pressure control solenoid valve 27 is averaged by the accumulator 30 to obtain the line pressure control valve.
Acts on 22. On the other hand, the pulsed control pressure from the shift control solenoid valve 28 directly acts on the other side of the shift speed control valve 23. In the figure, reference numeral 29 is a drain oil passage 31 is an oil pan, and 32 is an orifice.

The line pressure control valve 22 is a line pressure control solenoid valve 27.
The line pressure PL is controlled by the averaged control pressure.

The shift speed control valve 23 has a line pressure oil passage and an oil supply position connecting the line pressure oil passages 21 and 24 depending on the relationship between the regulator pressure and the pulse-shaped control pressure from the shift control solenoid valve 28.
24 and drain position to drain.

Then, the operating state at the two positions is changed according to the duty ratio to control the flow rate Q of oil supply or drain oil to the primary cylinder 9, and gear change control is performed at the gear change speed di / dt.

 The electric control system will be described with reference to FIG.

First, the speed change control system will be described. The speed change control system has a primary pulley 7, a secondary pulley 8, engine speed sensors 41, 42, 43, and a throttle opening sensor 44. Then, in the control unit, the rotation signals Np, Ns from the two pulley rotation speed sensors 41, 42 are input to the actual gear ratio calculating section 45, and the actual gear ratio i is obtained by i = Np / Ns. Further, the signal Ns from the secondary pulley rotation speed sensor 42 and the signal θ from the throttle opening sensor 44 are the target gear ratio search unit 46.
, And the target gear ratio is is searched from the table of Ns−θ based on the gear shift pattern.

The signal θ of the throttle opening sensor 44 is input to the acceleration detection unit 51, the throttle opening change Δθ is calculated by dθ / dt, and the coefficient setting unit 47 sets the coefficient k as a function of Δθ based on this. The actual speed ratio i of the actual speed ratio calculation unit 45, the steady target speed ratio is of the target speed ratio search unit 46, and the coefficient k of the coefficient setting unit 47 are input to the speed change speed calculation unit 48, and di / dt = k. The shift speed di / dt is calculated by (is-i), and if the sign is positive, it is determined to be downshift, and if it is negative, it is determined to be upshift.

The signals di / dt, i of the shift speed calculation unit 48 and the actual gear ratio calculation unit 45
Is further input to the duty ratio search unit 49. Here, due to the relationship of the duty ratio D = f (di / dt, i), di / dt and i
Is set, and the duty ratio D is distributed to a value of 50% or more for shift up, and the value of the duty ratio D is 50% or less for shift down. In upshifting, the duty ratio D is a decreasing function with respect to i, and | di / dt |
In contrast, the duty ratio D is set to an increasing function for i and an decreasing function for di / dt in downshifting. Therefore, the duty ratio D is searched using this table. Then, the signal of the duty ratio D from the duty ratio searching unit 49 is input to the shift control solenoid valve 28 via the driving unit 50.

Next, the line pressure control system will be described. The signal θ of the throttle opening sensor 44 and the signal Ne of the engine speed sensor 43 are input to the engine torque calculation unit 52, and the engine torque T is obtained from the table of θ−Ne. . On the other hand, the required line pressure setting unit 53 determines the required line pressure PLu per unit torque based on the actual transmission ratio i from the actual transmission ratio calculation unit 45, and this and the engine torque T of the engine torque calculation unit 52 are the target line. Input to the pressure calculation unit 54, PL = PLu ·
The target line pressure PL is calculated from T.

The output PL of the target line pressure calculation unit 54 is input to the duty ratio setting unit 55 to set the duty ratio D corresponding to the target line pressure PL. The signal of the duty ratio D is input to the line pressure control solenoid valve 27 via the drive unit 56.

On the other hand, in the above control system, the air conditioner switch 60, the signal is of the target gear ratio search unit 46 and the signal i of the actual gear ratio calculation unit 45 are input as the correction means during the operation of the air conditioner, and upshift is performed with the symbol is-i Alternatively, it has a shift determination unit 61 that determines downshifting. These signals are input to the correction amount calculation processing unit 62 to determine the correction coefficient α. When the air conditioner is not operating, α = 1, when the air conditioner is downshifting, α> 1, and when the upshifting is set, α <1. To do. Along with this, a signal corresponding to the gas discharge pressure of the air conditioner compressor from the air conditioner compressor load amount detection sensor 70 is input to the correction amount calculation processing unit 62 and subjected to calculation processing to determine the air conditioning load correction amount x.

In determining the air-conditioner load correction amount x, for example, as in the case of upshifting shown in the chart in FIG. 5, the engine side driving force indicated by the alternate long and short dash line A when the air conditioner is off and the two-dot chain line are indicated. The correction driving force on the engine side indicated by the solid line C, which is obtained by adding the driving force consumed by the compressor indicated by B, is subjected to arithmetic processing to determine an appropriate correction amount.

That is, in this case, a correction amount for downshifting is calculated so as to match the engine side correction driving force indicated by the solid line C, and this is set as the air conditioner load correction amount x.

If the air-conditioner load correction amount x changes continuously due to the relationship with the accelerator opening, etc. The amount calculation processing unit 62 may process the air-conditioner load correction amount x in a stepwise manner to determine the correction amount.

Further, when the air conditioner is off, the air conditioner load correction amount x is set to a predetermined constant k.

This correction signal is input to the coefficient setting unit 47 to correct x · α.

Next, the operation of the control device for the continuously variable transmission configured as described above will be described.

First, the power corresponding to the depression of the accelerator from the engine 1 is input to the primary pulley 7 of the continuously variable transmission 4 via the clutch 2 and the switching device 3, and the power changed by the drive belt 11 and the secondary pulley 8 is output. And this is the drive wheel
It travels by transmitting to the 16 side.

During the traveling, the target line pressure is set to be larger as the engine torque T is larger at a low speed stage where the value of the actual gear ratio i is large, and a corresponding signal having a large duty ratio is input to the line pressure control solenoid valve 27. Then, the control pressure is generated to be small, and the line pressure control valve 22 is operated with the averaged pressure to increase the line pressure PL of the line pressure oil passage 21. Then, as the gear ratio i becomes smaller and the engine torque T becomes smaller, the duty ratio is decreased to increase the control pressure, so that the line pressure PL is controlled so as to decrease due to the increase in the drain amount, and thus the drive is always performed. The belt 11 exerts a pulley pressing force corresponding to the transmission torque.

The line pressure PL is always supplied to the secondary cylinder 10, and the shift speed is controlled by supplying and discharging oil to the primary cylinder 9 by the shift speed control valve 23, which will be described below.

First, the signals Np, Ns, and θ from the sensors 41, 42, and 44 are read, and the actual speed ratio i is calculated by the speed change speed calculation unit 45 of the control unit 40, and the target speed ratio is is calculated by the target speed ratio search unit 46. , And the coefficient k is used by the shift speed calculation unit 48 to change the shift speed di / d.
Find t. Therefore, the shift-up and i
When the relationship of s> i is downshifted, the duty ratio search unit 49 searches the duty ratio D using the table based on di / dt and i.

The duty signal is input to the shift control solenoid valve 28 to generate a pulsed control pressure, which causes the shift speed control valve 23 to repeatedly operate at two positions, oil supply and oil discharge.

Here, in the shift-up, when the duty ratio D is 50% or more, the pulse-shaped control pressure by the shift control solenoid valve 28 is the regulator pressure PR that is off during the zero pressure time when on.
As the time increases, the speed change control valve 23 operates in the oil supply position for a longer time, and the primary cylinder 9 is supplied with more oil than the oil is drained to operate upshift. When | di / dt | is small on the low speed side with large i, the value of D is small and the amount of refueling is small and the shift speed is slow, but it shifts to the high speed side with small i and | di / dt | Becomes larger, the value of D becomes larger, the amount of oil supply increases, and the shift speed becomes faster. On the other hand, in the downshift, since the duty ratio D is a value of 50% or less, the control pressure is opposite to that described above, and the shift speed control valve 23 has a long operating time at the oil drain position, and the primary cylinder 9
It works as a drainage more than a refueling and works downshift. In this case, when di / dt is small on the low speed side where i is large, the value of D is large, so the amount of oil discharged is small and the shift speed is slow. As dt increases, the value of D decreases, the amount of oil discharged increases, and the gear shift speed increases. In this way, in the entire range of the low-speed stage and the high-speed stage, shifting up or down is performed while changing the shifting speed to continuously shift.

On the other hand, in the above shift speed control, the case where the air conditioner is operated or not will be described with reference to the flowchart in FIG.

First, when the air conditioner is not operating, the air conditioner switch 60
The correction amount calculation processing unit 62 sets α = 1 by the OFF signal of. Further, since the air conditioner load correction amount x is set to x = k in the correction amount calculation processing unit 62 by the OFF signal of the air conditioner switch 60, the coefficient of the coefficient setting unit 47 becomes k. Therefore, when the accelerator pedal is depressed, the actual gear ratio i changes with respect to the target gear ratio is shown in FIG. 4 as indicated by the alternate long and short dash line, smoothly downshifts, and then shifts up to follow is. Control speed.

On the other hand, when the air conditioner is operating, the ON signal of the air conditioner switch 60 is input to the correction amount calculation processing unit 62, whereby the air conditioner operating mode is set. Therefore, in the case of depressing the arcel, when the shift determination unit 61 determines that the shift is down due to the relation of is> i, the signal corresponding to the gas discharge pressure of the air conditioner compressor at that time is processed by the correction amount calculation processing unit 62. The coefficient is corrected to a large value by x · α (α> 1). Accordingly, the shift speed di / d of the shift speed calculation unit 48 is
The value of t also becomes large, and the required curve (not shown) from the upper part of the drawing within the range surrounded by the broken line in FIG. 4 is followed to shift down at a high shift speed. Then is <i
When it is determined that the shift is up due to the relationship, the coefficient x.alpha., Which is a signal obtained by calculating the signal corresponding to the gas discharge force of the air conditioner compressor at that time by the correction amount calculation processing unit 62.
(Α <1) is corrected to a smaller value, and the shifting speed di / dt
By decreasing the value of, shift up is performed at a slow speed.
For this reason, the time during which the vehicle is downshifted to the low speed stage becomes long, and along with this, the increase of the engine speed and the driving force is promoted.

Further, the line pressure control system also controls the line pressure by the above-described control of the actual gear ratio i, and when the driving force increases, a high line pressure corresponding to the line pressure control system is generated.

Also, when braking, such as applying the engine brake when the air conditioner is operating, this is detected in relation to the throttle opening, etc., and in the air conditioner operating mode, the signal corresponding to the gas discharge pressure of the air conditioner compressor at that time is corrected. The signal of the coefficient x · α calculated by the quantity calculation processing unit 62 is used to shift up and down so that the driving force for braking by the engine is reduced by a necessary and appropriate amount corresponding to the amount consumed by the consumed driving force of the air conditioner compressor. At this time, the gear ratio is controlled by the same means as when the throttle shown in FIG. 4 is opened.

The embodiment of the present invention has been described above.
It is also possible to correct the di / dt or the target gear ratio is and apply it to the prior art method.

〔The invention's effect〕

As described above, according to the present invention, when downshifting is performed so as to adjust the driving force of the engine by an amount corresponding to the driving force consumed by the air conditioner when the air conditioner is operating, the shift speed is increased, and when shifting up. Since the shift speed is corrected and controlled so as to slow down the shift speed, acceleration and braking can be favorably performed while correcting the power for driving the compressor, and the traveling performance is improved.

The structure of the control system is simple because it is configured only to control the values of the elements that determine the shift speed.

[Brief description of drawings]

FIG. 1 is a block diagram of an electric control system, FIG. 2 is a configuration diagram showing an embodiment of a control device of the present invention, FIG. 3 is a flow chart diagram for explaining the operation, and FIG. 4 shows a state of shift speed control. A diagram and FIG. 5 are explanatory diagrams of the engine-side correction driving force. 4 …… continuously variable transmission, 23 …… shift speed control valve, 40 …… control unit, 45 …… actual gear ratio calculation unit, 46 …… target gear ratio search unit, 47 …… coefficient setting unit, 48 …… Shift speed calculation unit, 60 ...
… Air conditioner switch, 61 …… Shift judgment section, 62 …… Correction amount calculation processing section.

Claims (2)

[Claims] 1. A primary pulley and a secondary pulley having variable pulley gaps respectively provided on a main shaft on the engine side and a sub shaft on the drive wheel side arranged in parallel with the main shaft, and a drive belt wound between both pulleys. In the continuously variable transmission that changes the ratio of the winding diameter of the drive belt with respect to both pulleys by the hydraulic pressure supplied to each servo device of the primary pulley and the secondary pulley and continuously changes the speed, A line pressure control valve that controls the line pressure that is supplied to the secondary pulley servo device in the hydraulic circuit that communicates with each servo device of the secondary pulley, and a shift that controls the operating hydraulic pressure of the primary pulley servo device that supplies and discharges the line pressure. A speed control valve and at least a regulator valve that produces a constant hydraulic pressure by draining the line control valve A line pressure control solenoid valve that is provided in a pressure circuit to generate a control hydraulic pressure according to an electric signal and acts on the line pressure control valve, and a constant hydraulic pressure circuit that generates a control hydraulic pressure according to an electric signal A shift control solenoid valve that acts on the shift speed control valve, and a control device that determines at least a target gear ratio to control the shift, and the control device adjusts the correction coefficient according to upshift and downshift and an air conditioner of the air conditioner. A correction amount calculation processing unit that calculates a correction amount of the shift speed based on the air-conditioner load correction amount according to the load is provided. A control device for a continuously variable transmission, which is small and increases a shift speed in the case of downshifting. 2. The air-conditioner load correction amount is a correction amount according to a consumption driving force of a compressor of the air-conditioner.
A control device for the continuously variable transmission described.