JPH05332432A - Controller of continuously variable transmission - Google Patents

Abstract

PURPOSE:To enable substantially smooth drive in the case when a motor for speed change command is out of order. CONSTITUTION:A sleeve 500 is fitted on the outer circumference of the spool 182 of a speed change command valve 108, and the spool can be driven in the axial direction by the sleeve. The sleeve is moved in the axial direction by oil pressure in R range. The sleeve is stopped by a snap ring. At the position where the sleeve is stopped by the snap ring 502 the spool of the speed change command valve is stopped at the position corresponding to the smaller speed change ratio than the maximum speed change ratio.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a continuously variable transmission in which a gear ratio is commanded by the position of a spool of a gear shift command valve.

[0002]

2. Description of the Related Art As a conventional control apparatus for a continuously variable transmission, there is, for example, one disclosed in Japanese Patent Laid-Open No. 62-265041. The control device for the continuously variable transmission shown therein determines the gear ratio of the continuously variable transmission mechanism in accordance with the position of the spool of the gear shift command valve. The spool of the shift command valve is axially driven by a step motor. Therefore, the gear ratio is determined according to the rotational position of the step motor.
If the step motor fails and does not operate, the gear ratio is fixed to a constant value. If the step motor fails in a state where the gear ratio is small, it becomes difficult to start the vehicle thereafter. Therefore, when the step motor fails, the spool of the shift command valve is returned to the maximum gear ratio position by hydraulic pressure. That is, when the manual valve is selected to the R position, the hydraulic pressure acts on the spool of the gear shift command valve, forcibly moving it to the maximum gear ratio position. This allows the vehicle to travel at the maximum gear ratio.

[0003]

However, in the conventional control device for a continuously variable transmission as described above, when the R range is selected, the spool of the gear shift command valve moves to the maximum gear ratio position, and thereafter, Held in a state. Therefore, you can always drive only at the maximum gear ratio,
It is difficult to continue the operation close to the normal state. The present invention aims to solve such problems.

[0004]

SUMMARY OF THE INVENTION The present invention solves the above problems by enabling the spool of the speed change command valve to be stopped at a predetermined gear ratio smaller than the maximum gear ratio when the motor fails. To do. That is, in the control device for a continuously variable transmission according to the present invention, the gear ratio of the continuously variable transmission is determined according to the axial position of the spool (182) of the gear shift command valve (108), and the spool of the gear shift command valve is a motor. (1
Assuming that it is axially driven by 10),
The inner diameter portion of the sleeve (500) is fitted to the outer diameter of one end side of the spool (182) of the shift command valve (108), and the expanded diameter portion (182C that prevents the sleeve from slipping out to the one end side is fitted to the spool. ) Is provided, the outer diameter of the sleeve is fitted in the valve hole (186) of the valve body, and oil is provided on the end side of the spool facing the enlarged diameter section, which is opposite to the end of the sleeve. A chamber (504) is formed, and the oil pressure is supplied to the oil chamber when the manual valve (104) is in a predetermined traveling range other than the D range, and the sleeve is provided when the oil pressure acts on the oil chamber. It can move to the one end side until it is stopped by the stopper (502), and the movement of this sleeve also moves the spool of the speed change command valve to a predetermined position, which is smaller than the maximum speed ratio. It is characterized in that the set in the position corresponding to the gear ratio.

[0005]

When the manual valve is selected to the R range (or the L range) other than the D range, hydraulic pressure acts on the oil chamber. As a result, the sleeve moves to a position where it is stopped by the stopper. The sleeve acts on the enlarged diameter portion of the spool of the shift command valve to move the spool. At the position where the sleeve is stopped by the stopper, the spool of the shift command valve stops at a position corresponding to a gear ratio smaller than the maximum gear ratio. Therefore, for example, if the R range is selected when the gear change command motor fails, a predetermined gear ratio smaller than the maximum gear ratio can be obtained. In this state, starting operation and traveling at a relatively high speed are possible. When the motor is normal, even if the sleeve is stopped by the stopper, the spool of the shift command valve can move further toward the higher gear ratio side.

[0006]

FIG. 2 shows a power transmission mechanism of a continuously variable transmission. This continuously variable transmission includes a fluid coupling 12, a forward / reverse switching mechanism 15, a V-belt continuously variable transmission mechanism 29, and a differential device 56.
Etc., the rotation of the output shaft 10a of the engine 10 can be transmitted to the output shafts 66 and 68 at a predetermined gear ratio and rotation direction. This continuously variable transmission includes a fluid coupling 12 (having a lockup oil chamber 12a, a pump impeller 12b, a turbine runner 12c, a lockup clutch 12d, etc.), a rotary shaft 13, a drive shaft 14, and a forward / reverse switching mechanism. 15, drive pulley 16 (fixed cone member 1
8, drive pulley cylinder chamber 20 (chamber 20a, chamber 20
b), composed of a movable cone member 22, a groove 22a, etc.),
Planetary gear mechanism 17 (Sun gear 19, pinion gear 21,
A pinion gear 23, a pinion carrier 25, an internal gear 27, etc.), a V-belt 24, a driven pulley 2
6 (fixed cone member 30, driven pulley cylinder chamber 32,
A movable conical member 34), a driven shaft 28, a forward clutch 40, a drive gear 46, an idler gear 48, a reverse brake 50, an idler shaft 52, a pinion gear 54,
Final gear 44, pinion gear 58, pinion gear 60, side gear 62, side gear 64, output shaft 66,
Although it is composed of the output shaft 68 and the like, detailed description thereof will be omitted. Regarding the structure of the part of which description is omitted, Japanese Patent Application Laid-Open No. 61-10 filed by the present applicant.
It is described in Japanese Patent No. 5353.

FIGS. 3, 4, 5 and 6 show a hydraulic control device for a continuously variable transmission. This hydraulic control device is provided with an oil pump 10
1, line pressure regulating valve 102, manual valve 104, shift control valve 106, shift command valve 108, step motor 11
0, shift operation mechanism 112, throttle valve 114, constant pressure pressure regulating valve 116, solenoid valve 118, coupling pressure regulating valve 1
20, a lock-up control valve 122, etc., which are connected to each other as shown in the figure, and further, a forward clutch 40, a reverse brake 50, a fluid coupling 12, a lock-up oil chamber 12a, a drive pulley. The cylinder chamber 20 and the driven pulley cylinder chamber 32 are also connected as shown. Detailed description of these valves and the like will be omitted. The part of which description is omitted is described in the above-mentioned JP-A-61-105353. Each reference numeral in FIGS. 3, 4 and 5 indicates the following member. Three-way valve 99, pinion gear 110a, tank 130, strainer 131, oil passage 132, relief valve 133, valve hole 13
4, ports 134a-f, spool 136, land 13
6a-b, oil passage 138, one-way orifice 139, oil passage 140, oil passage 142, oil passage 142L, one-way orifice 143, valve hole 146, ports 146a-g, spool 1
48, lands 148a to 148e, sleeve 150, spring 152, spring 154, gear ratio transmission member 158,
Oil passage 164, oil passage 165, orifice 166, orifice 170, valve hole 172, ports 172a-e, spool 174, lands 174a-c, spring 175, oil passage 176, orifice 177, link 178, oil passage 17
9, pin 181, rod 182, lands 182a-b,
Rack 182c, pin 183, pin 185, valve hole 18
6, ports 186a-d, oil passage 188, oil passage 189, oil passage 190, valve hole 192, ports 192a-g, spool 194, lands 194a-e, negative pressure diaphragm 19
8, orifice 199, orifice 202, orifice 203, valve hole 204, ports 204a to e, spool 2
06, land 206a-b, spring 208, oil passage 2
09, filter 211, orifice 216, port 2
22, solenoid 224, plunger 224a, spring 225, valve hole 230, ports 230a-e, spool 232, lands 232a-b, spring 234, oil passage 235, orifice 236, valve hole 240, port 24.
0a-h, spool 242, lands 242a-e, oil passage 243, oil passage 245, orifice 246, orifice 2
47, orifice 248, orifice 249, choke type throttle valve 250, relief valve 251, choke type throttle valve 252, pressure holding valve 253, oil passage 254, cooler 25
6, cooler pressure holding valve 258, orifice 259, changeover detection switch 298.

An electronic control unit 30 for controlling the operation of the step motor 110 and the solenoid 224 is shown in FIGS.
Indicates 0. The electronic control unit 300 includes an input interface 311, a reference pulse generator 312, a CPU (central processing unit) 313, a ROM (read only memory) 314,
It has a RAM (random access memory) 315 and an output interface 316, which are connected by an address bus 319 and a data bus 320. The electronic control unit 300 includes an engine speed sensor 301, a vehicle speed sensor 302, a throttle opening sensor 303, a shift position switch 304, a turbine speed sensor 305, an engine cooling water temperature sensor 306,
The signals from the brake sensor 307 and the change-over detection switch 298 are directly or waveform shapers 308, 309 and 32.
2, and through the AD converter 310, while passing through the amplifier 317 and lines 317a-d to the step motor 1
Although a signal is output to 10 and a signal is also output to the solenoid 224, detailed description thereof will be omitted. Incidentally, the configuration of the portion whose description is omitted is described in the above-mentioned Japanese Patent Laid-Open No. 61-105353.

FIG. 1 is an enlarged view of one end of the shift command valve 108. An enlarged diameter portion 182C is provided at one end of the spool 182 of the shift command valve 108. Spool 18
The inner diameter of the sleeve 500 is fitted to the outer circumference of the sleeve 2. The outer diameter portion of the sleeve 500 is fitted in the valve hole 186. A snap ring 502 serving as a stopper is fixed at a predetermined position of the valve hole 186. Valve hole 18
An oil chamber 504, which is defined by the spool 182 and the sleeve 500, is formed in the inner portion of 6. Oil chamber 504
An oil passage 138 is connected to. In the oil passage 138,
Hydraulic pressure is supplied when the manual valve 104 is in the R range.

For example, when the step motor 110 fails, if the manual valve 104 is selected to the R range, hydraulic pressure acts on the oil chamber 504 via the oil passage 138 and the three-way valve 99. The oil pressure in the oil chamber 504 is
, And pushes the sleeve 500 to the right in FIG. Therefore, the sleeve 500 moves to the right, and at the same time, the spool 182 of the shift command valve 108 also moves to the right. This movement of sleeve 500 continues until stopped by snap ring 502. Sleeve 50
When 0 is stopped by the snap ring 502, the spool 182 is located on the smaller gear ratio side than the position corresponding to the maximum gear ratio. That is, in this state, the gear ratio is smaller than the maximum gear ratio. This gear ratio is
For the time being, it is possible to take off and to some extent the vehicle speed,
For example, the gear ratio is such that the vehicle can travel at about 60 to 70 km / h. Therefore, even if the step motor 110 fails, it is possible to continue traveling for the time being. Since the spool 182 of the shift command valve 108 can move further to the right in FIG. 1 even when the sleeve 500 is stopped, the gear can be shifted to the maximum gear ratio when the step motor 110 is in a normal state. It is possible.
When the manual valve 104 is operated to select the L range, hydraulic pressure acts on the oil chamber 504 via the three-way valve 99,
The same operation as in the R range is performed.

Although the sleeve 500 is constructed so as to be sealed by being fitted in the valve hole 186, an O-ring may be provided on the outer circumference of the sleeve.
Although the snap ring 502 is used as a stopper for stopping the sleeve 500, it may be stopped by a plug fixed by a pin, a plate fixed by the valve body, or the like.

[0012]

As described above, according to the present invention, the spool of the gear shift command valve is moved to a predetermined position smaller than the maximum gear ratio when the motor for gear shift command fails. Compared with the case where the vehicle is fixed at, the vehicle can travel closer to the normal state.

[Brief description of drawings]

FIG. 1 is an enlarged view showing an end portion of a shift command valve.

FIG. 2 is a diagram showing a skeleton diagram of a continuously variable transmission.

FIG. 3 is a diagram showing a left part of a hydraulic circuit.

FIG. 4 is a diagram showing a central portion of a hydraulic circuit.

FIG. 5 is a diagram showing a right part of a hydraulic circuit.

6 is a diagram showing the relationship between FIGS. 3, 4 and 5. FIG.

FIG. 7 is a diagram showing the left part of the control unit.

FIG. 8 is a diagram showing the right part of the control unit.

9 is a diagram showing the relationship between FIGS. 7 and 8. FIG.

[Explanation of symbols]

 108 speed change command valve 110 step motor 182 spool 186 valve hole 500 sleeve 502 stopper 504 oil chamber

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Claims (1)

[Claims] 1. A continuously variable transmission configured such that a gear ratio of a continuously variable transmission is determined according to an axial position of a spool of a shift command valve, and the spool of the shift command valve is axially driven by a motor. In the control device of the machine, the inner diameter of the sleeve is fitted to the outer diameter of the spool of the speed change command valve, and the spool has an enlarged diameter that prevents the sleeve from slipping out to the one end. The outer diameter of the sleeve is fitted in the valve hole of the valve body, and an oil chamber is formed on the end side opposite to the end of the sleeve facing the enlarged diameter part of the spool. Hydraulic pressure is supplied to the chamber when the manual valve is in a predetermined traveling range other than the D range, and the sleeve is movable to the one end side until stopped by a stopper when hydraulic pressure acts on the oil chamber, this The control of the continuously variable transmission characterized in that the spool of the speed change command valve also moves to a predetermined position by the movement of the leave, and the predetermined position is set to a position corresponding to a predetermined speed ratio smaller than the maximum speed ratio. apparatus.