JP2668905B2 - Transmission control device for continuously variable transmission - Google Patents

Description

The present invention relates to a shift control device for a continuously variable transmission. (B) Conventional technology A conventional shift control device for a continuously variable transmission is disclosed, for example, in JP-A-57-161346. In the shift pattern shown, the gear ratio is uniquely determined with respect to the throttle opening and the vehicle speed. That is, if the throttle opening and the vehicle speed are the same, the commanded gear ratio always becomes the same. The gear ratio is generally set such that the larger the throttle opening, the larger the gear ratio. Further, the gear ratio is set to decrease as the vehicle speed increases. (C) Problems to be Solved by the Invention However, the conventional shift control device for a continuously variable transmission as described above has a problem that the driving feeling when the throttle opening is changed is not favorable. . That is,
When the throttle opening is increased, the gear ratio immediately shifts to the large side, and at the same time, the output torque of the engine increases. For this reason, the driving force rapidly increases. Conversely, when the throttle opening is reduced, the gear ratio immediately shifts to a small side, and at the same time, the output torque of the engine decreases. Therefore, the driving force is rapidly reduced. As described above, since the driving force greatly changes in response to the change in the throttle opening, it is difficult to drive the vehicle as intended by the driver. In order to solve such a problem, there is a method of giving hysteresis to the throttle opening signal when the throttle opening increases and when the throttle opening decreases (Japanese Patent Application No. 61-2749).
No. 30). However, if a constant hysteresis is always given, the following problem occurs. That is,
In general, the shift pattern has a relatively small change in the target engine rotation speed with respect to a predetermined amount of throttle opening change in the low throttle opening range, whereas the shift pattern has a target engine rotation with respect to the same throttle opening change in the high throttle opening range. The amount of change in speed is large. Therefore, for example, if a hysteresis with a favorable driving feeling is set in a region where the engine rotation speed is low, in a region where the engine rotation speed is high, the difference in engine rotation speed between when the accelerator pedal is depressed and when the accelerator pedal is returned is obtained even with the same throttle opening. It becomes large and a sense of discomfort occurs. An object of the present invention is to solve such a problem. (D) Means for Solving the Problems The present invention solves the above problems by reducing the hysteresis applied to the throttle opening signal in a region where the engine speed is higher. That is, the shift control device of the continuously variable transmission according to the present invention includes a throttle opening sensor that detects an actual throttle opening, and a signal from the throttle opening sensor that determines whether the engine rotation speed is increasing or decreasing. Is larger, the smaller the hysteresis is, the more the hysteresis is given to the throttle opening signal for control, and the target throttle ratio is determined by using the throttle opening signal for control as one input signal to realize the target gear ratio. Transmission control means for outputting a signal for operating the transmission actuator. (E) Function In the region where the engine rotation speed is high, the hysteresis given to the throttle opening signal is small. Therefore, when the throttle opening is changed by a fixed amount in a region where the engine rotation speed is high, and when the throttle opening is changed by the same amount in a region where the engine rotation speed is low, the change in the target engine rotation speed is almost the same. You can get the quantity. Therefore, for the same amount of change in the throttle opening over the entire engine speed range, a substantially constant change in the target engine speed can be obtained, and a constant driving feeling can be obtained. (F) Embodiment FIG. 2 shows a power transmission mechanism of the continuously variable transmission. This continuously variable transmission has a fluid coupling 12, a forward / reverse switching mechanism 15,
It has a V-belt type continuously variable transmission mechanism 29, a differential device 56, and the like, and can transmit the rotation of the output shaft 10a of the engine 10 to the output shafts 66 and 68 at a predetermined speed ratio and rotation direction. The continuously variable transmission includes a fluid coupling 12 (a lock-up oil chamber 12a, a pump impeller 12b, a turbine runner 12c
Etc.), a rotating shaft 13, a drive shaft 14, a forward / reverse switching mechanism 15, a drive pulley 16 (a fixed cone member 18, a drive pulley cylinder chamber 20 (chambers 20a and 20b), a movable cone member 22, a groove).
22a etc.), planetary gear mechanism 17 (consisting of sun gear 19, pinion gear 21, pinion gear 23, pinion carrier 25, internal gear 27, etc.), V-belt 24, driven pulley 26 (fixed cone member 30, driven pulley cylinder Chamber 32, movable cone member 34, etc.), driven shaft 28, forward clutch 40, drive gear 46, idler gear 48, reverse brake 5
0, idler shaft 52, pinion gear 54, final gear 4
4, pinion gear 58, pinion gear 60, side gear 62,
It is composed of a side gear 64, an output shaft 66, an output shaft 68, etc., but detailed description thereof will be omitted. The configuration of a portion whose description has been omitted is described in JP-A-61-105353 filed by the present applicant. FIG. 3 shows a hydraulic control device of the continuously variable transmission. This hydraulic control device includes an oil pump 101, a line pressure regulating valve 102, a manual valve 104, a shift control valve 106, a preparation pressure switching valve 108, a shift motor (step motor) 110, a shift operating mechanism 112, a throttle valve 114, a constant pressure. It has a pressure regulating valve 116, a solenoid valve 118, a coupling pressure regulating valve 120, a lock-up control valve 122, etc., which are connected to each other as shown in the figure, and also have a forward clutch 40, a reverse brake 50, The fluid coupling 12, the lock-up oil chamber 12a, the drive pulley cylinder chamber 20, and the driven pulley cylinder chamber 32 are also connected as illustrated. Detailed description of these valves and the like will be omitted. The parts for which the description has been omitted are described in
No. 105353. Each reference numeral in FIG. 3 indicates the following member. Pinion gear 110a, tank 13
0, strainer 131, oil passage 132, relief valve 133, valve hole 13
4, ports 134a-e, spool 136, lands 136a-b, oil passage 138, one-way orifice 139, oil passage 140, oil passage 142, one-way orifice 143, valve hole 146, ports 146a-g, spool
148, lands 148a-e, sleeve 150, spring 152,
Spring 154, transmission ratio transmission member 158, oil passage 164, oil passage 16
5, orifice 166, orifice 170, valve hole 172, port 17
2a-e, spool 174, land 174a-c, spring 17
5, oil path 176, orifice 177, lever 178, oil path 179, pin 181, rod 182, lands 182a-b, rack 182c, pin
183, pin 185, valve hole 186, port 186a-d, oil passage 188, oil passage 189, oil passage 190, valve hole 192, port 192a-g, spool 1
94, lands 194a-e, negative pressure diaphragm 198, orifice 199, orifice 202, orifice 203, valve hole 204, port 204a-e, spool 206, land 206a-b, spring 208, oil passage 209, filter 211, orifice 216 , Port 222, solenoid 224, plunger 224a, spring 22
5, valve hole 230, ports 230a-e, spool 232, land 232
ab, spring 234, oil passage 235, orifice 236, valve hole
240, ports 240a-h, spool 242, lands 242a-e,
Oil passage 243, oil passage 245, orifice 246, orifice 247, orifice 248, orifice 249, choke type throttle valve 250,
Relief valve 251, Choke type throttle valve 252, Holding pressure valve 25
3, oil passage 254, cooler 256, cooler pressure holding valve 258, orifice 259, changeover detection switch 278. FIG. 4 shows a shift control device 300 for controlling the operations of the step motor 110 and the solenoid 224. Shift control device 300
Is an input interface 311, a reference pulse generator 312,
CPU (central processing unit) 313, ROM (read only memory) 3
14. It has a RAM (random access memory) 315 and an output interface 316, these are the address bus 319
And a data bus 320. The shift control device 300 includes an engine rotation speed sensor 301, a vehicle speed sensor 302, a throttle opening sensor 303, a shift position switch 304, a turbine rotation speed sensor 305, an engine coolant temperature sensor 306, a brake sensor 307, and a switching detection switch 298. Signal directly or waveform shaper 3
08, 309 and 322, and input through the AD converter 310,
On the other hand, the stepping motor 1 through the amplifier 317 and the lines 317a-d
A signal is output to 10 and a signal is also output to the solenoid 224, but a detailed description thereof will be omitted.
The configuration of a portion whose description is omitted is described in the above-mentioned Japanese Patent Application Laid-Open No. 61-105353. FIG. 5 shows a part of the control performed by the transmission control device 300 that is directly related to the present invention. Other controls are the same as those described in the above-mentioned Japanese Patent Application Laid-Open No. 61-105353. First, the throttle opening sensor
The actual throttle opening signal TH and the engine speed signal N are read from the engine speed sensor 303 and the engine speed sensor 301, respectively (step 902). Next, a hysteresis amount H is obtained based on the engine rotation speed signal N (see FIG. 90).
Four). The relationship between the amount of hysteresis H and the engine speed signal N is set as shown in FIG. That is, the hysteresis amount H decreases as the engine rotation speed increases. Then, by adding the amount of hysteresis H in the control throttle opening signal TH _C, this is a temporary data TH _X for calculation (the 906). Next, the magnitude of the temporary data TH _X for calculation and the actual throttle opening signal TH are compared (step 908), and if the actual throttle opening signal TH is larger (that is, the actual throttle opening TH is increasing). the case), the actual hysteresis quantity H is subtracted from the throttle opening signal TH, which is referred to as control throttle opening signal TH _C (the 910). On the other hand, the actual throttle opening signal
If TH is smaller than the temporary data for calculation TH _X , the actual throttle opening signal TH becomes the control throttle opening signal TH _C
It is determined whether it is smaller than (912). When the actual throttle opening signal TH is small (that is, when the actual throttle opening TH decreases to the current control throttle opening signal TH _C ), the actual throttle opening signal TH is set as the control throttle opening signal TH _C. (The same in 914), and the process proceeds to step 916. Further, if the actual throttle opening degree signal TH is greater than the control throttle opening signal TH _C directly proceeds to step 916. The process also proceeds to step 916 from step 910 described above. In step 916, it is determined whether or not the control throttle opening signal TH _C is 0 or less. If it is 0 or less, the control throttle opening signal TH _{C is set} to 0 (step 918) and the process proceeds to step 920. Throttle opening signal for the control in step 920 TH _C is determined whether greater than the maximum value TH _m, the maximum value TH _m In the case larger than the maximum value TH _m
The a control throttle opening signal TH _C (the 922). Using the control throttle opening signal TH _C obtained by the control flow shown in FIG. 5 described above, searches the shift pattern from the relationship between this and the vehicle speed, searching a predetermined target engine rotational speed. Next, a signal for controlling the speed change motor so as to obtain the target engine rotation speed is output. This control is as described in the above-mentioned JP-A-61-105353. Eventually, the above control allows the control throttle opening signal TH
_C is the actual throttle opening signal TH given a predetermined amount of hysteresis H. That is, when the actual throttle opening signal TH is increasing, the value obtained by subtracting the hysteresis amount H is used for control. Conversely, when the actual throttle opening signal TH is decreasing, the current control throttle opening is reduced. until reduced to degrees signal TH _C holds the TH _C.
As shown in FIG. 6, the hysteresis amount has a characteristic that it decreases as the engine speed increases. Therefore, the hysteresis amount H is large in the region where the engine speed is low.
However, the hysteresis amount H decreases in a region where the engine rotation speed is high. Since the shift pattern generally has a characteristic as shown in FIG. 7, if the amount of hysteresis H becomes small in a region where the engine rotational speed is high, for example, when the throttle opening changes by 1/8, the target engine rotational speed is changed. The amount of change in the speed is relatively small, and is approximately the same as when the throttle opening changes 1/8 in a region where the engine speed is low. Thus, the change amount of the target engine rotation speed with respect to the throttle opening change amount can be made substantially constant over almost the entire range of the engine rotation speed, and a constant driving feeling can be obtained. (G) Advantageous Effects of the Invention As described above, according to the present invention, the amount of hysteresis given to the throttle opening signal is reduced in a high engine speed region, so that the throttle opening degree over the entire engine speed range. The change amount of the target engine rotation speed with respect to the change amount can be made substantially constant, and a constant driving feeling can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram showing a relationship between components of the present invention, FIG. 2 is a skeleton diagram of a continuously variable transmission, FIG. 3 is a diagram showing a hydraulic control circuit,
FIG. 4 is a diagram showing a shift control device, FIG. 5 is a diagram showing a flowchart, FIG. 6 is a diagram showing characteristics of a hysteresis amount,
FIG. 7 is a diagram showing a shift pattern.

Claims (1)

(57) [Claims] A throttle for controlling by providing a smaller hysteresis to the actual throttle opening signal from the throttle opening sensor to increase or decrease the actual throttle opening signal from the throttle opening sensor as the engine speed increases. A slope hysteresis providing means as an opening signal, a control throttle opening signal as one input signal to determine a target gear ratio, and a signal for operating a gear actuator to achieve the target gear ratio. A shift control device for a continuously variable transmission, comprising: a shift control means for outputting.