JPS61109953A - Electronic control device for stepless speed change gear - Google Patents

Abstract

PURPOSE:To permit to effect the optimum speed change under binding conditions of fuel consumption, exhaust gas or the like by a method wherein the electronic controls of a speed change ratio control valve and a line pressure control valve are effected by employing a torque motor. CONSTITUTION:A duty signal from a control unit 69 is inputted into the torque motor 49 of the line pressure control valve 45 and a spool is moved to control the line pressure while the line pressure is introduced into a sub-pulley servo chamber 28b at all times. On the other hand, said duty signal from the control unit 69 is inputted into the torque motor 59 of the speed change ratio control valve 55 and the spool is moved whereby the line pressure is supplied to or discharged out of a main pulley servo chamber 27b. Accordingly, the optimum speed change may be effected under the binding conditions of fuel consumption, exhaust gas or the like.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to an electronic control device that electronically controls a hydraulic control system of a boolean ratio converter in a belt-type continuously variable transmission for a vehicle.

[Prior art and problem 1] This type of continuously variable transmission has a main booster with variable booster spacing and n
The main part is a pulley ratio converting section consisting of one pulley and a drive belt wound between both boosters, and the hydraulic control system of this boolean ratio converting section is conventionally disclosed in Japanese Patent Laid-Open No. 55-65755, for example. There is prior art such as Publication No. Here, a hydraulic servo device is attached to the movable side boob half of each pulley, and a line pressure itI control valve that regulates line pressure in the hydraulic circuit and a line pressure itI control valve that supplies or discharges line pressure to one boob side to change speed. A gear ratio control valve is provided to convert the ratio. Then, on the main booster side, the centrifugal force of the oil extracts pitot pressure corresponding to the engine rotation and applies this to one side of the joint valve, and on the booster side, a feedback sensor that detects the actual gear ratio is connected via a spring. Line pressure Ul i
It is connected to the other side of the ll valve and controls the line pressure to prevent belt slip when transmitting engine torque by the belt. In addition, a throttle cam that rotates according to the throttle opening is connected to the other side of the gear ratio control valve via a spring, and the gear ratio is determined in relation to the pitot pressure corresponding to the engine rotation to control the speed change. All of these joint ventures have a mechanically operated structure. Therefore, in the above system, the gear ratio is uniquely determined by the shape of the throttle cam, spring load, pitot pressure characteristics, and spool shape in the gear ratio control valve. It is difficult to select the gear ratio. In addition, the starting point of the deceleration amount when the throttle is fully open depends on the pitot pressure detection m and the spool characteristics, and the engine speed at that starting point is high (therefore, there are problems such as not being able to obtain a sufficient deceleration effect at low speeds). [Object of the Invention] In view of the problem that arises when the operation mode of the joint venture of the hydraulic control system is uniquely determined as described above and the speed change is controlled based on this, the present invention has been made to This system sets the optimum gear ratio and line pressure in consideration of optimum fuel efficiency, exhaust gas purification, acceleration and deceleration characteristics, and operates the gear ratio control valve and line pressure control valve electrically based on these settings. It is an object of the present invention to provide an electronic control device for a gear transmission. [Configuration of the Invention] For this purpose, the configuration of the present invention is such that the moving stroke caused by an electric signal has good linear characteristics and has no hysteresis. configured to operate the spool of the gear ratio control valve and the line pressure iIi+ control valve using a small torque motor,
The optimum gear ratio and line pressure are determined based on the output and condition of the engine, and the torque motor operates the joint valve based on this, and the hydraulic pressure and actual gear ratio of each part of the hydraulic circuit are detected to set the target value. The gist of this is to perform feedback control to achieve convergence.

【Example】

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. The gear transmission 2 can be roughly divided into a forward/reverse switching section 3, a pulley ratio conversion section 4, a final reduction section 5, and a hydraulic control section 6.
It is composed of In the electromagnetic powder clutch 1, a drive member 9 with a built-in coil 8 is integrally connected to a crankshaft 7 from the engine, and a driven member 11 is integrally connected in the rotational direction by a spline to a transmission input shaft 1o. The drive and driven members 9, 11 are loosely fitted through a gap 12, and electromagnetic powder is collected from a powder chamber 13 in this gap 12. Further, a slip ring 15 is installed on the drive member 9 via a holder 14, and a brush 16 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. On the other hand, when the clutch current is cut, the drive due to the electromagnetic powder and the coupling force between the driven members 9 and 11 are lost, resulting in a clutch disengaged 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., the P
(parking) or N (neutral) range to D (
Clutch 1 is automatically connected and disconnected when switching to (drive) or R (reverse) range, eliminating the need for clutch pedal operation. 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 connected to the input shaft 10 and a reverse driven gear V719 rotatably fitted to the main shaft 1γ are connected to the counter gear 20.
and an idler gear 21, and a switching clutch 2 is connected between the main shaft 17 and the gears 18 and 19.
2 is provided. When the switching clutch 22 is engaged from the neutral position of the P or N range to the gear When engaged, the power of the input shaft 1o is decelerated and reversed by the gears 18 to 21, resulting in a reverse traveling state in the R range. In the boolean ratio converter 4, a sub shaft 23 is arranged parallel to the main shaft 17, and a main pulley 24 and an aJ pulley 25 are provided on both shafts 17 and 23, respectively.
An endless drive belt 26 is passed between the two ends. The pulleys 24 and 25 are each divided into two parts, and hydraulic servos 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 half-boot half 24a is brought closer to the movable half-boot 24a relative to the fixed half-boot 25b to gradually narrow the boot interval, and vice versa, the movable half-boot half 25a is moved away from the fixed half-boot half 25b to gradually narrow the pulley interval. As a result, the winding of the drive belt 2G around the pulley 24.25 changes the ratio of diameters so that continuously variable speed output power is taken out to the sub@23. In the final reduction section 5, a large-diameter final gear l732 meshes with an output gear 31 having an output @30, which is connected to the subshaft 23 via an intermediate reduction gear 29, and this final gear r321)s
The power is transmitted to the axles 34 and 35 of the left and right drive wheels via a differential mechanism 33. Furthermore, the oil pressure T11ti11 part G is provided on the main pulley 24 side by a pump drive shaft 3G that is directly connected to the engine crankshaft 7 through its main shaft 17 and input shaft 10, and an oil pump 37 is connected to the main pulley 24 side so that oil pressure is always generated during engine operation. provided. This pump oil pressure is then controlled by the oil pressure control circuit 38 according to the speed ratio, the throttle opening according to the accelerator depression, the engine rotation speed, etc., and is transmitted to each hydraulic nervo device on the main pulley and sub-boot side through oil passages 39 and 40. 27 and 28, and is configured to perform continuously variable speed control of the boolean ratio converter 4. To explain the speed change control system of the hydraulic control part 6 in FIG.
The movable pulley half 25a of the sub-pulley side hydraulic servo equipment @28 also fits into the cylinder 28a, and is operated by the line pressure of the servo chamber 28b. In this case, the bobbin half body 24a has a larger line pressure receiving area than the pulley half body 25a. An oil passage 40 from the sub-pulley servo chamber 28b communicates with an oil reservoir 42 via an oil pump 31 and a filter 41.
Branches from the oil pump discharge side to main pulley servo chamber 2
A line pressure υj control valve 45 and a gear ratio control valve 55 are provided in the oil passage 39 that communicates with 7I). The line pressure control valve 45 has a spool 47. It has boats 46a, 4fib, and a drain boat 46c that communicate with the oil passage 39, a spring 48 is biased on one side of the spool 47, and a torsion spring 51 installed within 5 degrees of the coil of the torque motor 49 is on the other side. come into contact with Then, the spring 51 moves the spool 47 by the magnetic flux of the coil 50 of the torque motor 49, so that the boat 46a
The line pressure is controlled by adjusting the opening degree of and 48c by w4. The gear ratio control valve 55 has a spool 57. Oil road 3
9 line pressure control valve 45. It has boats 56a, 56b and a drain boat 56C that communicate with the main pulley servo chamber 27b, and the spool 57 has a spring 58 and a torsion spring J5 in the coil 60 of the torque motor 59, similar to the line pressure control valve 45 described above. 61 acts in opposition. Then, by moving the spool 57 by the spring 61 of the torque motor 59, the boats 56a, 56
b is communicated with the main pulley servo chamber 27b to introduce line pressure into the main pulley servo chamber 27b for upshifting, or the boats 56b and 56c are communicated with each other to exhaust pressure from the main pulley servo chamber 27b for downshifting. In addition, the drain boat 46c of the above 8 valves 45.55, 5
6c is communicated with the oil reservoir 42 through an oil passage 62. Also, to explain the electric control system that controls each of the torque motors 49 and 59, the throttle distance sensor 63. is used to obtain engine information. Engine rotation sensor 64. It has air 70 meter 05 etc. Further, a main boolean oil pressure sensor 6G is provided on the main boolean arbor ff27b side of the oil passage 39 to obtain transmission output information. The oil passage 40 has an auxiliary pulley oil pressure sensor 67 and a pulley position sensor 68. Signals from these sensors are input to a control unit 69, and duty signals output from the control unit 69 are sent to each of the torque motors 49 and 59. coil 5
It is set to be input at 0.60. The control unit 69 determines the optimum gear ratio based on the optimum fuel consumption line and the R small NOx line based on the output torque characteristics based on the engine information, determines the main boost oil pressure to obtain this optimum gear ratio, and controls the oil pressure, that is, the gear shift. The auxiliary boolean oil pressure, or line pressure, is determined so that belt slip does not occur with respect to the ratio. Then, the transmission output information is compared with each of the above control values, and the output duty ratio is calculated based on the deviation according to a predetermined feedback algorithm, and the output duty ratio is converged to the target value. The spool movement by the spring 51.61 of the torque motor 49.59 is proportional to the duty ratio of current or voltage in the duty signal from the control unit 69. Next, the operation of one neck constructed in this way will be explained. First, to explain the overall operation, the line pressure is controlled by inputting the duty signal from the control unit 69 to the torque motor 49 of the line pressure control valve 45 and moving the spool, and this line pressure is always supplied to the sub-pulley servo chamber 28b. be introduced. Furthermore, the duty signal from the control unit 69 is input to the torque motor 59 of the gear ratio control valve 55 to move the spool, thereby supplying or discharging the line pressure to the main pulley servo chamber 27b. As a result, the diameter ratio of the belt winding around the main pulley 24 and the sub pulley 25 is changed, and the speed ratio is continuously variable between the maximum and minimum gear ratios. Therefore, the control of the gear ratio and line pressure will be explained in more detail using the flowchart of FIG. Find the main pulley oil pressure. Then, it compares the values detected by the sensors 6G and 68, and calculates and outputs the duty ratio based on the deviation. On the other hand, the auxiliary pulley oil pressure, that is, the line pressure, is obtained from a map of the relationship between the main boolean oil pressure and line pressure using the gear ratio as a parameter, and this is compared with the value detected by the sensor 67, and the duty ratio is calculated based on the deviation. and output it. Here, to explain about [l1I11] in the case of downshifting, the torque motor 5 is
The magnetic flux decreases in the coil 60 of 9, and the spring 6
The pressing force of 1 also decreases and the spool 57 moves to the right. Therefore, the oil pressure in the main pulley servo chamber 27b decreases and the gear is shifted down to the lower gear. On the other hand, the magnetic flux in the coil 50 of the torque motor 49 of the line pressure control valve 45 is also reduced based on the main boolean oil pressure and gear ratio in this case, and the spool 47
By moving the line pressure to the same right side, the line pressure increases to a predetermined value. Although one embodiment of the present invention has been described above, the downshift start point during deceleration with the throttle fully closed can also be optimally determined by creating a map in advance. In addition, the speed change range can be divided and economy or power driving can be selected for 1q. Effects of the Invention 1 As is clear from the above explanation, according to the present invention, since the gear ratio control valve and the line pressure control valve are electronically controlled using a torque motor, constraint conditions such as fuel consumption and exhaust gas can be reduced. This makes it possible to change gears, and in addition to this, various types of IL control can be performed. Since the valve is operated directly by a torque motor, the 418 design is simpler and easier to control than those that use pilot oil pressure.

[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 the position a according to the present invention, and Fig. 3 is a flow chart diagram explaining the operation. be. 2...Continuously variable transmission, 24...Main pulley, 25...
Sub-pulley, 26... Drive belt, 27b... Main pulley servo chamber, 28b... D1 pulley servo chamber, 45.
... Line pressure control valve, 55 ... Gear ratio control valve, 49.
59...Torque motor, 63...Throttle opening degree sensor, 64...Engine rotation sensor, 65.-17-
Turometer, 66, 67...Oil pressure sensor, 68...
Boolean position sensor, 69...control unit.

Claims (1)

[Claims] In the hydraulic control system of a continuously variable transmission, a gear ratio control valve and a line pressure control valve are configured to be operated by a torque motor, and each valve is controlled by the torque motor by determining the optimum gear ratio and line pressure based on engine information. An electronic control device for a continuously variable transmission, which performs feedback control so that the transmission output information matches the transmission output information.