JPS6060357A - Control device of speed change characteristic in stepless speed change gear - Google Patents

Abstract

PURPOSE:To perform accurate speed change control relating to a difference or the like in a running condition, by providing an economic range in which a speed change start point and speed change range are transferred to the low speed side. CONSTITUTION:A line pressure regulated by a pressure regulating valve 43 is supplied to the hydraulic servo device of a main pulley 24 through a speed change control valve 44 operated in relation to a throttle opening and an engine speed, and a speed change characteristic of economic range, in which a speed change start point and speed change range are transferred to the low speed side, is enabled to be provided in addition to the conventional speed change charcteristic by a power range cam part 51a and an economic range cam part 51b in the throttle cam 51 of the speed change control valve 44. In this way, accurate speed change control can be performed for a difference or the like in a running condi- tion because these speed change chracteristics can be suitably selected.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a speed change characteristic control device for making variable the speed change characteristics set by engine speed, throttle opening, and vehicle speed in a belt-type continuously variable transmission. This invention relates to a device that changes throttle cam characteristics corresponding to the throttle opening degree.

The main part of the continuously variable transmission of this scale is a pulley ratio converter consisting of a main pulley and a sub pulley with variable pulley intervals, and a drive belt wound between these pulleys.
Regarding the speed change control of such a pulley ratio converting section, there is a prior art, for example, disclosed in Japanese Patent Application Laid-Open No. 157930/1983. That is, the line pressure regulated according to the transmission torque of each speed ratio is always applied to the sub pulley side. On the other hand, the throttle cam is rotated according to the throttle opening, and the spring force that changes depending on the cam lift amount and the pitot pressure that corresponds to the engine rotation act against the speed change control valve, and the speed change control valve causes the above line By supplying or discharging pressure to the main pulley side, the winding radius of the sub-boot with respect to the main pulley of the drive belt, that is, the bobbin ratio or speed ratio, is changed to perform stepless speed change control.

By the way, the characteristics of the throttle cam according to the throttle opening and the characteristics of the pitot pressure according to the engine rotation are uniquely determined, so the operation of the speed change control valve based on these relationships is always constant, and as a result, the engine The speed change characteristics with respect to rotational speed and throttle opening are fixedly set regardless of running conditions, etc. Therefore, it is not possible to obtain accurate shifting characteristics for differences in driving conditions between flat areas and mountainous areas, and there are also problems in terms of fuel efficiency and the like.

In view of the problem of the fixedly set speed change characteristics of the conventional technology, the present invention obtains the speed change characteristics of the economy range in which the speed change start point and the speed change range are shifted to the low rotation side, and improves the speed change characteristics of the conventional power range. The object of the present invention is to provide a control plan for the speed change characteristics of a continuously variable transmission that allows the speed change characteristics to be changed arbitrarily.

For this purpose, in the device according to the present invention, a spring force corresponding to the throttle opening is applied in the direction of downshifting on the speed change control valve, and the lift amount to the throttle force is changed to be smaller than the throttle opening. The gist of this is to obtain the speed change characteristics of the economy range shifted to the low rotation side, and to switch between the power 1 non-ge and economy range by operating the range changeover switch.

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 consists of

Electric 1j powder type crudge 1] Crankshaft 1 from carrot
A drive member 9 with a built-in coil 8 is integrally connected to the transmission input shaft 10, and a driven member 11 is integrally spline-connected in the rotational direction to the transmission input shaft 10, and these drives and driven members 9 and 11 are connected through a gap 12. The gap 12 is loosely fitted so that electromagnetic powder is accumulated from the powder chamber 13 in this gap 12.

Further, a slip ring 15 is attached to the drive member 9 via a holder 14, and a brush 16 for power supply is in sliding contact with the slip ring 1, 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 operating 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 (drive), L (low) or R (reverse) range, the clutch 1 is automatically connected and disconnected, making it unnecessary to operate the clutch pedal.

Next, in the continuously variable transmission l12, the switching part 3 is provided between the input shaft 10 from the clutch 1 and the main shaft 17 of the continuously variable transmission &'12 disposed coaxially therewith. A reverse drive gear 18 integrally coupled to the human power shaft 10 and a reverse driven gear A719 rotatably fitted to the main shaft 17 are meshed together via a counter gear 20 and an idler gear 21, and these main shaft 11 and gear 1
A switching clutch 22 is provided between 8.19 and 19.

Then, from the neutral position of the P or N range, the switching clutch 22
When engaged to the gear 18 side, the main shaft 17 is directly connected to the input shaft 10 to set the D or forward range, and when the switching clutch 22 is engaged to the gear 19 side, the power of the input shaft 10 is transferred to the gear 18. to 21, the vehicle is decelerated and reversed to enter the R range reverse state.

In the boolean ratio converter 4, a sub-shaft 23 is arranged parallel to the main shaft 17, and a main pulley 24 and a sub-pulley 25 are electrically connected to these two wheels 17 and 23, respectively, and a second pulley 24.
An endless drive belt 26 runs between the two. The pulleys 24 and 25 are each divided into two parts, and the movable pulley halves 24a and 25a are equipped with a hydraulic servo device 2.
7 and 28 are attached to make the boob interval variable.

In this case, the main pulley 24 is the fixed pulley half 2
The movable pulley half 24a is moved closer to 6- pulley half 4b, and the pulley interval is gradually narrowed, and the sub pulley 25 is moved away from the fixed pulley half 25b, so that the pulley interval is gradually increased. As a result, the drive belt 26
The winding around the pulleys 24 and 25 changes the diameter ratio so that the continuously variable power is not extracted to the subshaft 23.

In the final reduction section 5, a large-diameter final gear 32 meshes with an output gear 31 of an output shaft 30 connected to the subshaft 23 via an intermediate reduction gear 29, and a large-diameter final gear 32 is connected to the output gear 31 through a differential 111 and a paulownia 33. The power is transmitted to the axles 34 and 35 of the left and right drive wheels.

Further, the hydraulic control unit 6 has a hydraulic pump 37 on the main pulley 24 side so as to generate hydraulic pressure during engine operation through a pump drive shaft 36 that passes through the main shaft 17 and the input shaft 10 and is directly connected to the engine crankshaft 7. provided. Then, this pump assistant is controlled by the hydraulic control circuit 38 according to the throttle opening and engine rotation speed according to the depression of the accelerator, and is connected to each hydraulic servo device on the main pulley and sub-boot side via oil passages 39 and 40 @21°. 28, and the pulley ratio change '
It is configured to perform the continuously variable speed control of P14.

To explain the speed change control system in FIG. 2, the hydraulic servo device 21 on the main boolean side
4a also serves as a piston and is fitted into the cylinder 27a, and is operated by the line pressure of the servo chamber 27b, and also in the hydraulic υ-bo 8112B on the sub-pulley side, the movable pulley half-rest 25a is fitted into the cylinder 28a, It is operated by the line pressure of the servo chamber 28b, and in this case, the pulley maternity leave 2
4a has a larger pressure receiving area for line pressure than the half-opening 25a.

An oil passage 40 from the sub-pulley servo chamber 28b communicates with an oil reservoir 42 via a hydraulic pump 37 and a filter 41, and an oil passage branches from the oil pump discharge side of this oil passage 40 and communicates with the main pulley servo chamber 27h. Pressure regulating valve 4 in 39
3 and a speed change control valve 44 are provided.

The speed change control valve 44 is made up of a valve body 45, a spool 46, a spring 47 biased against one of the spools 46, and an actuating member 48 that changes the spring force. A rotation sensor 49 installed on the side to detect the engine rotation speed 1
The pitot pressure from
8 is in contact with a throttle cam 51 that rotates according to the throttle opening. In addition, the port 45 of the valve body 45
b is the land 46a of the spool 46;

4fSb selectively communicates with one of the line pressure supply port 45c and the drain port 45d, the boat 45b communicates with the servo chamber 27b via the oil passage 39a of the oil passage 39, and the boat 45c communicates with the oil passage 39b. The drain boat 45d is connected to the pressure regulating valve 43 side, and the drain boat 45d is connected to the oil passage 52.
It communicates with the oil sump side.

As a result, in the spool 46 of the speed change control valve 44, a pitot pressure corresponding to the engine speed of the boat 45a,
A spring force corresponding to the throttle opening due to the rotation of the throttle cam 51 acts in opposition, and the operation is based on the relationship between these two forces. That is, when the pitot pressure increases as the engine rotates, the ports 45b and 45c communicate with each other, supplying line pressure to the main pulley servo chamber 27b and starting a shift to the high gear side. The larger the force 41 is, the more the shift start point is delayed and shifted to the high rotation side.

Next, the pressure regulating valve 43 is connected to the valve body 53. Spool 54° Consists of a spring 55 biased on one side of the spool 54, with the spring 55 on the spool 54 and the boat 5 on the opposite side.
The pitot pressure of the oil passage 50 and the line pressure of the oil passage 39G are guided to 3a and 53b, respectively, and the spring 55 has a feedback sensor that engages with the movable pulley half 24a of the main pulley 24 to detect the actual gear ratio. 56 are connected. Further, the oil passage 39c on the pump side 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 port 1-45d. The spool 54 is moved left and right by the pitot pressure and the force of the spring, and the communication between the line pressure port 53c and the oil passage 52 on the drain side is controlled by the notch in the land 54a of the spool 54. It is designed to regulate line pressure.

As a result, the pitot pressure etc. acts on the spool 54 of the pressure regulating valve 43 in the direction of draining the line pressure and decreasing it, and in response, the force of the spring 55 corresponding to the gear ratio of Acts to increase line pressure. Since the force of the spring 55 is large in low gears where the transmitted torque is large, the line pressure is set high, and the line pressure is controlled to decrease as the gear shifts to the high gear side. Maintains pressing force.

In the above configuration, according to the present invention, a cam lift characteristic changing mechanism 60 is attached to the throttle cam 51 of the speed change control valve 44, and this will be explained with reference to FIG.

That is, the throttle cam 51 has a fourth
The cam part 51a of the conventional power range, which has the lift characteristics shown by the solid line a in the figure, and the cam part 51b of the economy range, which has the overall small lift amount as shown by the broken line i in the figure, are integrated. nigu II. Further, a shaft 61 of the throttle cam 51 is supported to be movable in the axial direction with respect to a bearing 62, and an electromagnetic actuator 63 is attached to one end of the shaft 61.
The pin 64 comes into contact with the throttle cam 51, and a return spring 65 is urged on the opposite side of the throttle cam 51 from the actuator 63. The actuator 63 is a range selector switch 66. The circuit is configured in the battery 67 and the switch 66
When turned on and energized, the pin 64 protrudes and the shaft 61 moves and the cam portion 51b comes into contact with the operating member 48.

With this configuration, when the vehicle starts running, the line pressure regulated by the pressure regulating valve 43 is supplied only to the auxiliary pulley servo chamber 28b, and the belt wrapping around the auxiliary pulley 25 is the largest on the shuttle, as shown in FIG. A solid line! The gear ratio shown is the maximum. After traveling in this state, the pitot pressure corresponding to one engine rotation in the speed change control valve 44 overcomes the spring force corresponding to the throttle opening and moves the spool 46 to the left, and the boat 45h.

45c is in communication, line pressure is also supplied to the main pulley side by the hydraulic servo device 27 which has a large pressure receiving area, and as a result, the belt winding diameter I" of the main pulley 24 increases, as shown by the solid line in FIG. The gear ratio is continuously variable between the high speed gear and the minimum gear ratio.

By the way, in the above speed change control, the range changeover switch 6
6 is turned off, the returning action of the spring 65 brings the cam portion 51a of the throttle cam 51, which has a large lift amount, into contact with the operating member 48. Therefore, the value of the spring force of the spring 47 in the shift control valve 44, which corresponds to the throttle opening, is large in accordance with the lift amount of the cam portion 51a, and therefore, a large pitot pressure is required for shifting. Therefore, immediately after driving, the state of the maximum gear ratio continues for a long time, and the gear shift starts at point P1 on the high rotation side.
Along with this, the speed change range is also set to the high rotation side, resulting in the speed change characteristics of the power range shown by @a in FIG.

Next, when the range selector switch 66 is turned on, the pin 64 of the actuator 63 protrudes and engages the throttle cam 51.
The cam portion 51b having a small lift amount is in contact with the actuating member 48. Therefore, due to the characteristics of the cam portion 51b, the spring force of the speed change control valve 44 according to the throttle opening is changed to a smaller value as a whole, making it easier to change speed. Therefore, the shift start point P1 and the shift range are set to a lower rotation side than those described above, and as shown by wAb in FIG. 5, the shift characteristics are in the economy range.

As is clear from the above description, according to the present invention, 13- In the shift control system of the continuously variable transmission, in addition to the conventional shift characteristics, the shift start point and shift range are shifted to the low rotation side. Since speed change characteristics are provided, by selecting these speed change characteristics, it is possible to perform accurate speed change control in response to differences in driving conditions, etc., and particularly in the case of an economy range, fuel efficiency etc. can be significantly improved. 4M structurally variable speed control valve 4
4, the throttle cam 51 that applies a spring force according to the throttle opening degree is used to change the characteristics of this cam lift, so the structure is simple and the operation is reliable. Furthermore, the range can be changed by operating a switch, making it easy to operate.
The relationship between the operating position and the like can be easily determined.

[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 device according to the present invention, and Fig. 3 is a 'g! FIG. 4 is a lift characteristic diagram of the throttle cam, and FIG. 5 is a shift characteristic diagram. 14-2...Continuously variable transmission, 24...Main pulley, 25...
Sub-pulley, 26... Belt, 43... Pressure regulating valve,
44...speed change control valve, 46...spool, 41...
・Spring, 48... Operating member, 51... Thrower 1 to cam, 51a... Power range cam part, 51b
...Economy range cam section, 60...Change mechanism, 6
1...Axis, 63...Actuator, 66...Range selection switch. Patent Applicant Fuji Heavy Industries Co., Ltd. Agent Patent Attorney Makoto Kobashi Ukiyo Patent Attorney Susumu Murai 15- Figure 3 Figure 2 Figure 4 Figure 5 Car Layout

Claims (1)

[Claims] In a continuously variable transmission that has a pulley ratio conversion unit consisting of a main pulley and a sub pulley with variable pulley intervals and a drive belt wound between both pulleys, the line pressure regulated by a pressure regulating valve is A throttle cam that controls speed by supplying or discharging water to the hydraulic servo device of the main pulley using a speed change control valve that operates in relation to the opening degree and engine rotation, and to which a spring force is applied according to the throttle opening degree by the speed change control valve. The lift characteristic of the vehicle is changed by operating a changeover switch to obtain a shift characteristic in which the shift start point and shift range are set on the high rotation side, or other shift characteristics in which the shift start point and shift range are set on the low rotation side. Shift characteristic control device for continuously variable transmission.