JPS59231250A - Control device for continuously variable transmission - Google Patents

Abstract

PURPOSE:To make it possible to rapidly change a speed change ratio, by adding correction based on a degree of rapid acceleration to a target speed change ratio signal. CONSTITUTION:A speed change control device 300 includes a rapid speed-change detection means and means for correcting a target speed change ratio upon rapid speed change. A target speed change ratio signal is corrected by reading the target speed change ratio signal from a map in ROM314 and then adding a predetermined amount of correction value to the target value. In other words, electrical signals from an engine speed sensor 301, vehicular speed sensor 302, throttle position sensor 303, shift position sensor 304, speed change reference switch 298, engine coolant temperature sensor 306 and brake sensor 307 are inputted to the speed change control device 300. A reference pulse generator 312 in the speed change control device 300 generates a reference pulse for operating CPU313. The ROM314 stores control programs and control data for a step motor 110 and a force motor 224. RAM315 temporarily stores information from each sensor and switch and parameter, etc. required for control. An output signal from the control device is fed through an amplifier 317 and a current controller 318 to the step motor 110 and the force motor 224.

Description

[Detailed description of the invention] (b) Technical field The present invention relates to a control device for a continuously variable transmission.

(b) Prior art In the conventional V-belt type continuously variable transmission, for example,
As disclosed in No. 46153, the rotational speed of the drive pulley and the throttle opening of the engine are detected, and the actual operating state of the engine is determined based on this, and the engine is based on a preset speed change pattern. compared with the target operating state, and controlled the gear ratio to minimize the deviation between the two. However, the conventional V
With belt-type continuously variable transmissions, speed change control is performed based on the same shift pattern whether you want to accelerate rapidly or slowly, so when you need sudden acceleration such as when overtaking, There was a problem in that rapid acceleration could not be achieved.

” - In order to solve the problem mentioned above, the applicant filed a patent application filed in 1983.
In No. 63868, ``Speed change control method for V-belt type continuously variable transmission'' (filed on April 19, 1981), a method for rapidly changing the gear ratio during sudden speed changes was disclosed. That is, in this method, for example, when the throttle opening increases rapidly, the value of the throttle opening signal is modified so that it becomes larger than the actual throttle opening, and the value of the throttle opening signal is modified based on this modified throttle opening signal. The target gear ratio signal in the storage device was then read out. Generally, the larger the throttle opening signal, the larger the value of the target gear ratio, so the deviation between the target gear ratio and the actual gear ratio becomes larger, allowing rapid gear changes. However, this method may also cause the following problems. In other words, the value of the target gear ratio is stored in the memory device as a map with vehicle speed and throttle opening as variables, but this is an ideal gear shifting pattern in a steady state. Even if only the value is modified, the amount of modification of the target gear ratio is not constant depending on the location of the map, and the target gear ratio may not be modified as desired (
For example, if the target gear ratio signal on the map hardly increases even if the throttle opening signal increases a little, or if the target gear ratio signal on the map increases slightly, or if the throttle opening signal is slightly modified,
(e.g., when the target gear ratio changes significantly). This is because the ideal shift pattern assumes steady driving and does not take into account sudden acceleration.

(c) Purpose of the Invention The object of the present invention is to provide a control device for a continuously variable transmission that can rapidly change the gear ratio as desired during sudden acceleration in any operating state.

(D) Structure of the Invention The present invention solves the above problem by correcting the target gear ratio signal after reading it from the storage device based on the degree of sudden acceleration. That is, the control device for a continuously variable transmission according to the present invention includes a sudden speed change detection means that calculates the rate of change of a signal from an engine load sensor, and a correction value that is determined according to the degree of sudden speed change calculated by the sudden speed change detection means. and a target speed change ratio correction means for sudden speed change which calculates the speed change ratio signal.

(e) Examples Examples of the present invention will now be described with reference to FIGS. 1 to 5 of the accompanying drawings.

(First example) FIG. 1 shows the power transmission mechanism of a continuously variable transmission.

This continuously variable transmission transmits the rotation of the input shaft 2 to the output shafts 76 and 78 via the drive pulley 6, bell) 50, driven pulley 51, etc. by engaging the forward clutch 4 or the reverse clutch 24. can do. This continuously variable transmission includes an input shaft 2, a forward clutch 4, a drive pulley 6, a drive shaft 8, an oil pump 10, a drive gear 12, and a driven gear 14.
, rotating groove 16, oil pool 18, pitot tube 20, subshaft 2
2. Reverse clutch 24, gears 26.28, 30.32
and 34, piston chambers 36 and 38, fixed conical plate 40
, drive pulley silling chamber 42, movable conical plate 44, rotating groove 46, oil pool 47, pitot tube 48, belt 50
, driven pulley 51, driven shaft 52, fixed conical plate 54, driven pulley cylinder chamber 56, spring 57, movable conical plate 58, gear 60, ring gear 62, differential case 64,
Although it is composed of pinion gears 66 and 68, a differential device 70, side gears 72 and 74, and output shafts 76 and 78, detailed explanation thereof will be omitted. Regarding the structure of the parts whose explanations are omitted, please refer to Japanese Patent Application No. 184627-1983 filed by the present applicant, ``Control Device for Hydraulic Automatic Clutch'' (filed on October 22, 1981).
It is described in.

FIG. 2 shows a control device for a continuously variable transmission. As shown in FIG. 2, the control device for this continuously variable transmission includes an oil pump 1
0, line pressure regulating valve 102, manual valve 104, speed change control valve 106, clutch complete engagement control valve 108, speed change motor (step motor) 110, speed change operation mechanism 112, throttle valve 114, starting valve 116, start adjustment valve 118 , a maximum gear ratio holding valve 120, a reverse inhibitor valve 122, a lubricating valve 124, a tank 130, an electronic control device 300, etc., which are connected to each other as shown in the figure, and a piston of the forward clutch 4. It is also connected to the chamber 36, the piston chamber 38 of the reverse clutch 24, the driving pulley silling chamber 42, the driven pulley cylinder chamber 56, and the pitot tubes 20 and 48. Although the speed ratio can be continuously controlled by controlling the operation of the step motor 110 that constitutes the speed change actuator, detailed explanation thereof will be omitted. In addition,
Regarding the structure of the parts whose explanation is omitted, please refer to the above-mentioned patent application filed in 1983.
-184627.

Next, the speed change control device 300 that controls the operation of the speed change motor (step motor) 110 and the force smoke 224 will be explained.

As shown in FIG. 3, the shift control device 300 includes an engine rotation speed sensor 301, a vehicle speed sensor 302. Electric signals from the engine load sensor include an throttle opening sensor (or intake pipe negative pressure sensor) 303, a shift position switch 304, a shift reference switch 298, an engine coolant temperature sensor 306, and a brake sensor 307. An engine rotational speed sensor 301 detects the ignition speed of the engine, and a vehicle speed sensor 302 detects the vehicle speed from the rotation of the output shaft of the continuously variable transmission. The throttle opening sensor (or intake pipe negative pressure sensor) 303 detects the throttle opening of the engine as a voltage signal (in the case of an intake pipe negative pressure sensor, the intake pipe negative pressure is detected as a voltage signal).
. The shift position switch 304 detects which position of the manual valve 104 is in P, R, N, D, or L. The speed change reference switch 298 is connected to the speed change operation mechanism 112.
This is a switch that is turned on when the rod 182 reaches the position where the gear ratio is greatest. Engine coolant temperature sensor 306 generates a signal when the engine coolant temperature is below a certain value. Brake sensor 307 detects whether the vehicle's brakes are being used. Signals from the engine speed sensor 301 and vehicle speed sensor 302 are sent to the input interface 311 through waveform shapers 308 and 309, respectively, and the voltage signal from the throttle opening sensor (or intake pipe negative pressure sensor) 303 is sent to the AD converter. 310 converts it into a digital signal and sends it to an input interface 311. The speed change control device 300 includes an input interface 311, a CPU
(Central processing unit) 313, reference pulse generator 312, R
OM (read only memory) 314, RAM (random access memory) 315, and output interface 3
16, which are connected by an address bus 319 and a data bus 320. Reference pulse generator 312 generates reference pulses that operate CPU 313. The step motor 110 is stored in the ROM 314.
It also stores programs for controlling the force motor 224 and data necessary for the control.

The RAM 3 L 5 temporarily stores information from each sensor and switch, parameters necessary for control, and the like.

The output signal from the speed change control device 300 is transmitted to the step motor 1 via an amplifier 317 and a current controller 318, respectively.
10 and force motor 224.

Next, the details of the specific control of the step motor 110 performed by the speed change control device 300 will be explained. Note that the speed change control device 300 includes a force motor 224.
is also controlled, but since it has no direct relation to the present invention, its explanation will be omitted. The parts whose explanation is omitted are the same as those described in the above-mentioned Japanese Patent Application No. 184627/1983.

FIG. 4 shows a control flowchart. First, step 9
At step 02, various signals indicating the operating status are read. That is, the engine rotation speed signal N from the engine rotation speed sensor 301, the vehicle speed signal V from the vehicle speed sensor 302, and the throttle opening signal TH from the throttle hearing sensor 303 (engine load sensor) are read. Next, the process proceeds to step 904 to calculate the rate of change (cart(/dt)) of the throttle opening signal.

That is, the throttle opening signal TH is differentiated by time t. Next, it is determined whether the differential value dTH/dt is positive or not (step 906), and if the differential value is O or negative, it is set to =O (step 908), step 9
Proceed to step 12. On the other hand, if the differential f1 is positive in step 906, the differential value multiplied by the constant C is set as K, that is, K=C·(dTH/dt), and the process proceeds to step 912. In step 912, based on the read throttle opening signal TH and vehicle speed signal V, RO
The target gear ratio signal iD is read from M314. Then,
K is added to this read iD and this is set as a new target gear ratio signal io (step 914). Next, in step 916, the actual gear ratio iR is calculated from the engine rotational speed N and the vehicle speed V, and in step At 918, the deviation e between the actual gear ratio iH and the target gear ratio ip is calculated. Next, in step 920, a step motor drive signal (shift command signal) is calculated using a predetermined function using the deviation e as a variable, and then this is output (step 9
22). The output step motor drive signal has a deviation e
The larger the value, the faster the step motor 110 is rotated.

As a result, when the throttle opening is moved to the large side (that is, when the accelerator pedal is depressed) by the control described in (g), a value corresponding to the displacement speed of the throttle opening is added to the target gear ratio, Since the step motor drive signal is calculated based on this corrected target speed ratio, the step motor rotates at high speed. Therefore, the more rapidly the accelerator pedal is depressed, the more rapidly the gear change will be performed.

In this way, since a predetermined correction value is added depending on the depression speed of the accelerator pedal, the shift speed can always be increased as desired, and the driver does not feel uncomfortable. On the other hand, when the accelerator pedal is held constant or when the amount of accelerator pedal depression is decreased, R
The speed change speed of the step motor is controlled by the target speed ratio as stored in the OM 314. Note that when the accelerator pedal is depressed gently, the correction value is very small, so the gear change is controlled in accordance with the target gear ratio that is stored in the memory.

As mentioned above, the modification of the target gear ratio signal according to the present invention includes:
After reading from the map in the ROM 314, a predetermined amount of correction value is added to the map, so that appropriate correction can always be made in all operating conditions. That is, when correcting the throttle opening signal and reading the target gear ratio signal from the map based on the corrected throttle opening signal as in the past, the correction may not necessarily be suitable depending on how the target gear ratio is set in the map. However, according to the present invention, appropriate modifications can always be made as described in section 2.

Note that reading from the map in the ROM 314 described above may be performed by determining the actual gear ratio iH in advance and using the throttle opening signal TH and the engine rotational speed signal N.

(f) As described in detail, the present invention includes a speed change actuator that can continuously control the speed ratio according to a given speed change command signal, an engine load sensor that detects the engine load, and an engine load sensor that detects the engine load. At least one of an engine rotation speed sensor that detects rotation speed or a vehicle speed sensor that detects vehicle speed, and a signal that controls the gear ratio so that the engine is operated according to preset conditions, are connected to the engine rotation speed or vehicle speed. and a storage means for storing a map of one of the engine speed and the engine load, and a predetermined signal is read out from the storage means according to one of the detected engine rotational speed or vehicle speed and the engine load, and a shift command signal is issued in accordance with the read signal. A control device for a continuously variable transmission having a speed change command means for inputting to a speed change actuator, a sudden speed change detection means for calculating a change rate of a signal from an engine load sensor, and a degree of sudden speed change calculated by the sudden speed change detection means. Since the present invention is equipped with a sudden gear change target gear ratio correction means that calculates a corresponding correction value for the target gear ratio signal, it is possible to shift at an appropriate high speed during sudden gear changes under all kinds of rolling conditions. This improves driving performance.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a V-belt continuously variable transmission, FIG. 2 is a diagram showing the entire control device, FIG. 3 is a block diagram showing the control device, and FIG. 4 is a diagram showing control flowchart 1. FIG. 5 is a complaint correspondence diagram. 110--Step motor (speed change actuator),
No. 3010 - Engine rotation speed sensor, 302# Fist・
Vehicle speed sensor, 303... Throttle opening sensor (
engine load sensor), 314...-ROM. Patent applicant Nissan Motor Co., Ltd. Agent
Patent Attorney Toshiyuki Miyauchi Figure 3 1 121

Claims (1)

[Claims] At least a shift actuator capable of continuously controlling a gear ratio according to a given shift command signal, an engine load sensor that detects engine load, an engine rotation speed sensor that detects engine rotation speed, or a vehicle speed sensor that detects vehicle speed. On the one hand, a storage means for storing a signal for controlling the gear ratio so that the engine is operated according to preset conditions as a map of either the engine rotation speed or the vehicle speed and the engine load, and the detected engine A control device for a continuously variable transmission, comprising a shift command means for reading a predetermined signal from a storage means in accordance with either rotational speed or vehicle speed and engine load, and inputting a shift command signal to a shift actuator in accordance with the read signal. , a sudden shift detection means for calculating the rate of change of the signal from the engine load sensor; and a sudden shift target for calculating a correction value for the target gear ratio signal according to the degree of sudden shift calculated by the sudden shift detection means. 1. A control device for a continuously variable transmission, comprising a gear ratio correcting means.