JPS60125452A - Transmission controller for continuously variable transmission - Google Patents

Abstract

PURPOSE:To attain transmission characteristics that the transmission is quiet at the low speed of a vehicle and importance is attached to acceleration performance at the high speed of the vehicle, by downshifting a transmission control valve through the operation of a shifting cam at the time of kick-down acceleration below a set vehicle speed, and more downshifting the valve at said time above the set vehicle speed independently of the operation of the cam. CONSTITUTION:Below a set vehicle speed V0, a vehicle speed switch 62 is off, a signal with a high level is generated and the output of a NOR gate 64 is put on a low level so that an actuator 61 is put out of action independently of kick- down operation. At the time of the kick-down operation, an operating member 48 is pushed in by a shifting cam 51 so that a transmission control valve 44 is downshifted. When the kick-down operation is performed above the set vehicle speed V0, switches 62, 63 are both turned off so that the actuator 61 is put into action. At that time, the operating member 48 is pushed in by the actuator 61 independently of the shifting cam 51 so that the transmission control valve 44 is downshifted.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a gear shift control III device for a belt-type continuously variable transmission for a vehicle, and in particular to a gear shift control III device for a belt-type continuously variable transmission for a vehicle, and in particular a gear shift line during kick-down acceleration with the throttle fully open, that is, a gear change line, that is, a maximum gear change engine rotation speed, which changes depending on the vehicle speed. Regarding.

Regarding the gear ratio lIIII of this type of continuously variable transmission, there are conventional technologies such as those disclosed in Japanese Patent Application Laid-Open No. 52-98861 and Japanese Patent Application Laid-Open No. 55-65755. It is shown that the speed change is controlled by supplying and discharging the line pressure to the main pulley side in relation to the spring force according to the torque Wa or the negative pressure of the intake manifold.

By the way, according to this speed change control system, as shown in FIG.
J: Sea urchin maximum speed ratio curve L1 and minimum speed ratio curve j
! 2, a shift line Ill Jl is set for each engine rotation based on the pedal stroke of the axle. Therefore, the gear shift line ll3 for all throttle positions is also uniquely determined, and the gears are shifted along this gear shift line ll3 during kickdown acceleration, but the actual driving force reaches the minimum gear ratio curve 11,t. Since the running resistance becomes less than , the gear shift ends at point P1 and the maximum vehicle speed becomes ■1. Therefore,
Raise the maximum engine speed like Pl and R high vehicle speed ■
If an attempt is made to increase it to 2, if the shift line in this case is a predetermined number such as m4, the engine rotational speed during kickdown acceleration at lower vehicle speeds will also uniformly increase. 01121222Increasing the rotation speed is significant in that it increases the maximum vehicle speed through gear shifting.At vehicle speeds below this, there is no need to increase the engine rotation speed, but an increase in the engine rotation speed will improve fuel efficiency and cycle speed. It is unfavorable in terms of

In view of these circumstances, it is an object of the present invention to provide a shift control device for a continuously variable transmission that is quiet at low vehicle speeds and provides shift characteristics emphasizing acceleration performance at high vehicle speeds.

For this purpose, the present invention downshifts the shift control valve by operating the shift cam when the vehicle speeds below the set speed of 311, and downshifts the shift control valve by a large amount regardless of the operation of the shift cam. The gist of this is to shift the shift line to a higher engine speed side and increase the maximum vehicle speed by shifting.

Hereinafter, one embodiment of the present invention will be specifically described with reference to the drawings. First, as an example of a continuously variable transmission to which the present invention is applied in FIG. 1, a continuously variable transmission with an electromagnetic powder clutch will be described. Broadly speaking, the stage change gear III2 is composed of a forward/reverse switching section 3, a pulley ratio converting section 4, a final reduction section 5, and a hydraulic control section 6.

In the electromagnetic powder clutch 1, a drive member 9 with a built-in coil 8 is integrally connected to a crankshaft 1 from the engine, and a driven member 11 is integrally connected in the rotation direction by a spline to a shaft 10 entering the transmission. , these drive and driven members 9° and 11 are loosely fitted through a gap 12, so that electromagnetic powder is collected from the powder chamber 13 into this gap 12. Further, a slip ring 15 is installed on the drive member 9 via a holder 14, and a brush 1G for power supply is in sliding contact with the slip ring 15 so that a clutch current flows through the coil 8.

In this way, when a clutch current is applied to the coil 8, electromagnetic particles are combined in a chain shape and accumulated in the gap 12 between the drive and driven members 9 and 11 due to the lines of magnetic force generated between the drive and driven members 9 and 11.
Due to this coupling force, the driven member 11 slides and is integrally coupled to the drive member 9. -h, when the clutch current is cut, the drive due to electromagnetic powder and the coupling force between the driven members 9 and 11 disappear, resulting in a clutch disconnection state. In this case, if the clutch current is supplied and cut in conjunction with the operation of the switching section 3 of the continuously variable transmission 2 with a shift lever, etc.,
P (parking) or N to neutral) range to D (
When switching to the R (drive) or R (reverse) range, the clutch 1 automatically moves back and forth, making it unnecessary to operate the clutch pedal.

Next, in the continuously variable transmission 2, the switching section 3 connects the input shaft 10 from the clutch 1 and the main shaft 1 disposed coaxially therewith.
7, a reverse drive gear 18 integrally coupled to the input shaft 10 and a high-speed driven gear 19 rotatably fitted to the main shaft 17 are meshed through a counter gear A720 and an idler gear 21. Furthermore, a switching clutch 22 is connected between the main shaft 11 and the gears 18 and 19.
is set number. Then, when the switching clutch 22 is engaged to the gear 18 side from the neutral position of the P or N range, the input shaft 1
When the main shaft 17 is directly connected to the D or L range and the switching clutch 22 is engaged to the gear 19 side, the power of the input shaft 10 is decelerated and reversed by the gears 18 to 21, and the R
Put the range in reverse mode.

In the pulley ratio conversion unit 4, a sub-shaft 23 is arranged parallel to the main shaft 11, and a main pulley 24, a sub-pulley, and 25 are provided on both wheels 17 and 23, respectively, and a D-pulley 24°2.
An endless drive belt 26 is passed between 5 and 5. The pulleys 24 and 25 are each divided into two parts, and hydraulic servo devices 27 and 28 are attached to the movable pulley halves 24a and 25a to make the interval between the pulleys variable.

In this case, the main pulley 24 is the fixed pulley half 2
The movable pulley half 24a is brought closer to the fixed pulley half 25b () to gradually narrow the pulley interval, and the sub pulley 25 is moved away from the fixed pulley half 25b to gradually increase the pulley interval. As a result, the ratio of the winding (JG) diameters of the pulleys 24.25 of the drive belt 26 is changed to output continuously variable power to the subshaft 23.

In the final reduction section 5, a large-diameter final gear 32 meshes with the output gear 31 of an output shaft 30 connected to the subshaft 23 via an intermediate reduction gear 1729, and a large-diameter final gear 32 meshes with the output gear 31 of the output shaft 30, which is connected to the subshaft 23 via an intermediate reduction gear 1729. Axle of left and right drive wheels 34°3
5 transmission configuration.

Further, the oil pressure control unit 6 has an oil pump 37 on the main pulley 24 side so as to generate oil pressure during engine operation through a pump drive shaft 3G that passes through the main shaft 11 and the input shaft 10 and is directly connected to the engine crankshaft 7. provided. This pump oil pressure is controlled by the oil pressure control circuit 38 according to the vehicle speed, the throttle opening according to the accelerator pedal depression, the engine rotation speed, etc., and is transmitted through oil passages 39 and 40 to each hydraulic servo device ff127. Supplied to 28,
It is configured to perform continuously variable speed control of the pulley ratio converter 4.

To explain the speed change control system of the hydraulic control unit 6 in FIG. 2, in the hydraulic servo device M27 on the main boolean side, the movable pulley half 24a also serves as a screw for the cylinder 2.
7a, and is operated by the line pressure of the servo chamber 27b. Also in the hydraulic servo device 28 on the sub-pulley side, the movable pulley half 25a is fitted to the cylinder 28a, and is operated by the line pressure of the servo chamber 28b. In this case, the pulley Y body 24a has a larger line pressure receiving area than the pulley half-closed 25a.
, oil 1 [! A pressure regulating valve 43 and a speed change control valve 44 are provided in an oil passage 39 that communicates with the main pulley servo chamber 27b and branches from the oil pump discharge side of the oil passage 40 and communicates with the main pulley servo chamber 27b.

The speed change control valve 44 consists of a valve body 45, a spool 4G, a spring 47 biased to one side of the spool 46, and an actuating member 48 that changes the spring force. Rotation sensor 4 (installed on the side) to detect the engine rotation speed
Pitot pressure from 9 is guided to C through an oil passage 50, and a shift cam 51 that rotates in accordance with the throttle opening is in contact with the operating portion 44B. In addition, the boat 45b of the valve body 45
is selectively communicated with one of the line pressure supply boat 45c and the drain boat 45d through lands 46a and 46b of the spool 46, and the boat 45b is communicated with the servo chamber 27b through an oil passage 39a of the oil passage 39. , the boat 45c communicates with the pressure regulating valve 43 side through the oil passage 39b, and the drain boat 45d communicates with the oil reservoir side through the oil passage 52.

As a result, in the spool 4G of the speed change control block ↑44, the pitot pressure according to the engine speed of the boat 45a and the throwers 1 to 1
The spring force corresponding to the degree of rotation acts in opposition to each other, and the operation is based on the relationship between the two. That is, when the pitot pressure rises with the engine rotation, the boats 451) and 45c communicate with each other to supply line pressure to the main pulley servo chamber 2711 to start shifting to the high gear side, and at this time, the gear shift is started according to the throttle opening. When the force of the spring 47 is large, the starting point during the above-mentioned speed change is shifted to the high speed side of the engine rotation.

Next, the pressure regulating valve 43 includes a valve body 53, a spool 54,
It consists of a spring 55 that is biased on one side of the spool 54, and the ball 1-1 on the opposite side of the spool 54 from the spring 55.
53a and 53b respectively indicate the pitot pressure of the oil passage 50;
The line pressure of the oil passage 39c is introduced to the spring 55, and a feedback sensor 56 that engages the movable pulley half 24a of the main pulley 24 and detects the actual gear ratio is connected to the spring 55 via a bushing 57. Furthermore, the oil passage 39 on the pump side
c always communicates with the oil passage 39b on the speed change control valve side regardless of the position of the spool 54. Moreover, the oil passage 52 on the drain side also communicates with the boat 53d.

The spool 54 moves slightly from side to side due to the pitot pressure and the force of the spring, and the communication between the line pressure boat 53c and the drain side oil passage 52 is controlled by the notch in the land 54a of the spool 54. It is designed to regulate the pressure.

As a result, the pitot pressure etc. acts on the spool 54 of the pressure regulating valve 43 in a direction to drain the line pressure and decrease it, whereas the force of the spring 55 according to the gear ratio by the feedback sensor 5G increases the line pressure. Acts on the direction. Since the force of the spring 55 is large in the low speed gear where the transmission torque of I-C1 is large, the line pressure is set high, and the line i= is controlled to decrease as the gear shifts to the high gear side.
Always maintain a pulley pressing force that does not cause belt slip.

Further, in the above configuration, the operating member 48 of the speed change control valve 44
A downshift actuator 61 is connected via an engagement member 60 to the downshift actuator 61 . On the other hand, the vehicle speed switch 62 detects the set vehicle speed. It has an accelerator switch 63 that detects when the throttle is fully open, and these switches 62 and 63 are designed to output an L level signal when turned on at the set vehicle speed or when the throttle is fully opened. Gate 64. It is connected to the actuator 61 via a driving transistor 65.

Next, the operation of the transmission control device configured in this way will be explained using FIGS. 1, 2, and 3. When the vehicle is running, the line pressure diverted by the pressure regulating valve 43 is always supplied to the sub-pulley servo chamber. 28b and the transmission 111III
It is supplied to or discharged from the main pulley servo chamber 27b by the II valve 44. Accordingly, the pulley ratio of the sub pulley 25 to the main pulley 24 of the drive belt 26 is changed, and the speed is continuously variable between the curve L1 with the maximum gear ratio and the curve 12 with the minimum gear ratio.

Therefore, in such shift control, the set vehicle speed V.

In the following, the vehicle speed switch 62 is turned off to output a signal at level l, and the output of the NOR gate 64 is set to level l, so the actuator 6 is turned off regardless of the presence or absence of the kickdown operation.
1 is inactive. Therefore, during kick-down acceleration with the throttle fully open, the shift control valve 44 pushes the actuating member 48 by the shift 1 to cam 51 to downshift, and the shift line in this case is determined based on the shape of the shift cam 51 as shown in FIG. is set as m3.

On the other hand, when performing a kickdown operation at a vehicle speed higher than the set vehicle speed Vo, both sweeps -62. '63 are both turned on, the output of the NOR gate 64 becomes 1 level, and the actuator 1 is activated. Therefore, the actuating member 48 of the speed change control valve 44 is operated by the actuator 6 regardless of the shift cam 51.
1, resulting in a downshift, and the shift line in this case is set to the high engine speed side, as indicated by M4 in FIG. 3, based on the stroke of the actuator 61. Therefore, At point P at the end of the shift, where the actual driving force becomes less than the running resistance of the vehicle and no further acceleration is possible, a higher maximum vehicle speed v2 is obtained than in the case of shift line a.

As is clear from the above description, according to the present invention, when the vehicle speed is low during kick-down acceleration of the entire throttle field, the shift line is set in the shape of the shift cam 51, and the engine speed is not particularly increased. It does not cause problems such as fuel consumption or noise. On the other hand, in the case of a high vehicle speed, the shift line is set to the side where the engine speed is higher than those described above, and the maximum vehicle speed is increased, so that acceleration performance is improved.

[Brief explanation of drawings]

Fig. 1 is a skeleton diagram showing an example of a continuously variable transmission to which the present invention is applied, Fig. 2 is a circuit diagram showing an embodiment of a device according to the present invention, and Fig. 3 shows transmission characteristics according to the present invention. line diagram,
FIG. 4 is a conventional transmission characteristic diagram. 2... Continuously variable transmission, 6... Hydraulic control section, 44...
Shift control valve, 61... downshift actuator, 62... vehicle speed switch, 63... accelerator switch, 66... control circuit.

Claims (1)

[Scope of Claims] A downshift actuator is provided in the shift control valve operated by the hydraulic control section of the continuously variable transmission, which is operated by means for detecting a set vehicle speed and means for detecting 1 degree of throttle IFf. Kickdown tribe. At high speed, the actuator moves up &! Shift control for a continuously variable transmission characterized by a structure in which the shift RIJ control valve is downshifted a lot regardless of shift cam operation, and the shift line in this case is shifted to the higher engine speed side. .