JPS60104851A - Control device of continuously variable transmission - Google Patents

Abstract

PURPOSE:To prevent overrun of an output shaft by applying a specified fluid signal to a ration control valve when the rotating speed of an output shaft reaches a present value to enlarge a torque transmission ratio. CONSTITUTION:A ratio control valve 10 for controlling the ratio of control oil pressure of the primary pulley control valve 8 to that of the secondary pulley control valve 7 is disposed between both valves 7, 8, and a fluid signal from car velocity detection means 12 connected to a governor 11 is input to the ratio control valve 10. In this arrangement, when the rotating speed of an output shaft reaches a preset value, a specified fluid signal is applied from the car velocity detection means 12 to the ratio control valve 10 to enlarge the torque transmission ratio, whereby the rotating speed of the output shaft is decreased to prevent overrun of the output shaft.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention is an adjustment device for a fljlj control device that controls the torque transmission ratio between input and output shafts in a continuously variable transmission. be.

(Prior art) Currently, mechanical transmissions are often used as transmissions, which use multiple gear trains to change the torque transmission ratio of the input and output shafts in stages according to the gear ratio. There is. In this case, the torque transmission ratio changes in one step, so
There is a drawback that the torque transmission ratio cannot be selected at will, and for this reason, a stepless control system that allows the torque transmission ratio τ to be changed steplessly has been much admired.

For example, one example of a hydraulic continuously variable speed bale machine is the H8T (hydrostatic transmission), which combines a hydraulic motor and a hydraulic pump, and a belt type transmission is one example of a mechanical continuously variable speed bale machine. 1. A belt-type continuously variable transmission that changes the average effective diameter of the 40mm pulley.
It can be mentioned as a chestnut.

In such a continuously variable transmission, the range of change in the torque transmission ratio can be considerably widened due to its structure, and this can cause problems such as the output m (b) rotation speed becoming too large. There is sex. For example, if the torque transmission ratio is set to 0.5 (2.0 in terms of reduction ratio), the input shaft z = cas, o o o RPM output shaft rotation is 1
0,000it p 1v. For this purpose,
Don't make the torque transmission ratio too small; l+I
Although it is possible that the input ig rotation is at low and medium speeds, such a small torque transmission ratio can be used to improve engine startup and improve fuel efficiency. It is also not very desirable to have a structure in which the torque transmission ratio cannot be used. However, if the output shaft rotates at too high a speed, the centrifugal force acting on the rotating parts connected to the cutting shaft will increase and cause damage to these parts, or the bearings may rotate beyond the allowable rotation of the bearings that support the output shaft rotating system. There is a possibility that the problem of damage may occur.

In view of these circumstances, for example,
966 +i has a belt type silent gear shift 1, and J6 has a secondary goo') (tJ3 force 'ill 1 rule pulley)
The centrifugal force exerted by the rotation of the weight attached to the belt mechanically changes the radius of the belt and changes the torque transmission ratio, and the rotation of the secondary pulley changes as well. It has been disclosed that when t and f exceed +11'n, the centrifugal force of the helper weight is also applied to rapidly change the torque transmission ratio, so that the secondary pulley starts rotating. . In this case, the belt type stepless variable: An example of when the torque transmission ratio of the first base machine is permanently changed.
In some cases, this is done using a body type Acuna Yuta. When discharging 1ffJ using a fluid type actuator, the operation of the mt type actuator is fljlJ jjl
It is effective to prevent the output from rotating at a high speed of ++m and overrun, and a device that performs such control is required.

(Purpose of the Invention) The present invention was made in view of the above-mentioned problems, and aims to increase the rotation speed of the output shaft of a continuously variable transmission that uses a fluid actuator to steplessly change the torque transmission ratio. Sometimes this hydraulic actuator increases the torque transmission ratio (
Accordingly, it is an object of the present invention to provide a control device that prevents overrun of an output shaft.

(The device of the present invention, which is constituted by the invention, uses a bjt body actuator to steplessly change the torque transmission ratio from the human power shaft to the output shaft of a continuously variable transmission, and also transmits a signal indicating the running state of the vehicle. The supply of working fluid to the fluid actuator is adjusted using a ratio control valve that is activated when fluid is added, and the torque transmission ratio is variably controlled according to the vehicle's driving conditions. In the J device, the vehicle speed detecting means or No. 46 corresponding to the single unit outputs a signal indicating that the rotation speed of the output shaft has reached the set value, and instructs the ratio control pulp to greatly increase the torque transmission ratio. It is said that it is made to have an effect on the body.

Furthermore, when the control device of the present invention detects that the rotational speed of the output agent has reached the set value, the control device of the present invention detects that the rotational speed of the output agent has reached the set value, and when the control device detects that the rotational speed of the output agent has reached the set value, It is added to the ratio control pulp to greatly increase the torque transmission ratio.

(Baby fruit of the invention) According to the present invention, when the output speed reaches the set value, the torque transmission ratio is reduced. It is possible to prevent damage caused by the centrifugal force of the surface rotation of the output l1q11 times private system, and damage to the bearings that support them.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a hydraulic circuit diagram showing one embodiment of the YTFIJ control device of the present invention, and here an example is shown in which a belt type continuously variable transmission is used.

The brima pulley 1 consists of a one-inch flange 1a fixed on the input shaft, and a sliding flange 1b that rotates around the fixed flange 1a and can freely slide on the input shaft. 1VkaJ is applied in the axial direction by the primary cylinder 2. The secondary pulley 3 consists of a fixed flange 3a fixed on the output shaft and a sliding flange 3b that rotates around the fixed flange 3a and can freely slide on the output shaft. 4 in the axial direction.

Brima pulley 1 and secondary pulley 3 are V-belt 2
0 is connected, and the rotation of the brake pulley 1 (rotation of the input shaft) is transmitted through the V-belt 20 to the secondary pulley 3.
(output shaft). At this time, the force of the V-belt 20 at the pulleys 1 and 3 changes depending on the operation of the primary cylinder 2 and the secondary printer 4. That is, by controlling the oil pressure supplied to both cylinders 2.4, the effective radius of both pulleys 1 and 3 of the V-belt 20 can be changed, and the torque transmission ratio can be changed steplessly.

To explain the control of the hydraulic pressure supplied to both cylinders 2 and 4, first, the hydraulic bonder 6 sucks the oil in the sump 5 and discharges it through the line 48 and line 6a to supply the secondary cylinder 4 and the secondary cylinder 4. Supply hydraulic pressure to the control pulp 7. The operating pressure of the secondary link 4 is controlled by the secondary pulley 11 valve 7. The oil discharged from the secondary pulley 7 passes through line 7a and enters the primary pulley control pulp 8, where the oil pressure supplied to the primary cylinder 2 via line 2a is controlled. The primer 1 valve control valve 8 is located downstream of the secondary valve control valve 7, so in order to operate both valves independently, the primary valve control valve 8 must be operated separately.
The oil pressure supplied to the secondary printer 2 must be lower than the oil pressure supplied to the secondary printer 4. Therefore, the pressure receiving area of the primary cylinder 2 is made larger than the pressure receiving area of the secondary printer 4, and both - The forces applied to sliding flanges 1 and 3, 91b and 3b are balanced.

On the other hand, the Brimarigoo system? Between the E1 knob 8 and the secondary pulley control 1 knob 7, there are provided 10 ratio control loops ζ, which communicate with both knobs 8 and 7 via remalines 10a and 10b. The control oil pressure Q) ratio of both loops is controlled to 1. Both/(
loop control oil pressure, i.e. primary cylinder 2θ)
When the ratio of the working oil pressure to the working oil pressure of the secondary cylinder 4 is changed, the forces acting on the sliding flanges lb and 3b of both pulleys are larger on one side and smaller on the other, and the force acting on the V-belt 20 on both pulleys 1 and 3 is also increased. The effective radius is reduced and the torque transmission ratio changes. In other words, the yaw torque transmission ratio is controlled to the ratio control valve]0. In addition, secondary pulley ili: J'l Wholesale Pulp 7 fljlJ
ll1 (When the I pressure is changed, the oil pressure ratio of the ratio control + roll valve IO and the rotation ins 2a and 4a is kept constant, so the oil pressure of lines 2a and 4a both rise and fall, changing the tension of the V-belt 20. In other words, secondary pulley + trll (
Wholesale Pulp 7 is the tension of V-belt 20'l iif!
l #I will do it.

On the other hand, the dynamic pressure in the oil gutter IC provided at the fixed flange 1i+11 of the primary pulley 1 is detected by the pipe 9, and the oil pressure (governor pressure pc) corresponding to the rotation of the primary pulley 1 is detected by the line 9a and 9b [obtained. The line 9a is connected to the secondary pulley control valve 7, and the tension of the V-belt 20 is controlled according to the rotation of the primary pulley 1. Line 9b is connected to ratio control valve IOK, and this ratio control valve 10 receives oil pressure from throttle valve 13, which generates oil pressure according to the engine throttle opening.
Throttle pressure PT) is applied to line 9 via line 13a.
The ratio control valve 10 is actuated in response to opposing hydraulic pressure from line 91) and line 13a. Specifically, as the rotation of the primary pulley 1 increases, the torque transmission ratio is decreased, and as the throttle opening increases, the torque transmission ratio is controlled to increase. Furthermore, a line 13 from the throttle valve 13 is connected to the ratio control valve 10.
A line 12a from the vehicle speed detection means 12 is connected to the same side as a. The vehicle speed detection means 12 detects (
That is, when the hydraulic pressure is received via the line lla from the governor valve 11 which generates hydraulic pressure (according to the rotation of the secondary pulley 930), and when it is detected that the vehicle speed has reached the set value, that is, the secondary pulley 3 has reached the set rotational speed, the line 1
A predetermined signal fluid is supplied to 22 to operate the ratio control valve 0 to increase the torque transmission ratio.

In this embodiment, the pressure Pc applied to the valve 7.1 may be a hydraulic pressure that changes depending on the freezing temperature.

FIG. 2 is a sectional view showing the vehicle speed detection means 12 shown in FIG.
Supply line lla from 1/O control valve] O supply fins 12a are formed, and both lines lla
A, ], 2a, a school 14 is disposed so as to be slidable left and right in the figure. This spool 14 is biased to the left by a spring 15, and its left end counteracts the old force of the spring 15 by receiving the hydraulic pressure of the operating boat 11b connected to the line lla. When the oil pressure of line 11a is low, the spool 14 is pushed to the left by the biasing force of spring 15, and life 11C and line 12 are connected to line lla.
The communication of line 12a is cut off, and line 12a is connected to Evejest port Ex via line 12b. Therefore, the oil pressure in line 12 is zero. When the rotational speed of the secondary pulley 3 increases and the hydraulic pressure supplied from the governor valve 11 to the line lla increases, the hydraulic pressure acting on the left end of the spool 14 also increases, and the rotational speed of the secondary pulley 3 reaches the set value, and the line lla,] , 1b reaches the set oil pressure, the stool 14 is moved by the spring 15 due to this oil pressure.
The first part of the spool 14 is moved to the right against the urging force of the
Line llc and line 12a communicate through groove 1.42, and second groove 14b of spool 14 is closed, cutting off communication between line 12 and line 12a.

Therefore, the oil pressure in line lla operates on the ratio control valve 10 through line 12a, increasing the torque transmission ratio and preventing overrun.

FIG. 3 is a graph showing the relationship between engine speed and vehicle speed in a vehicle using the σ continuously variable transmission of the present invention, where line L] represents the relationship when the torque transmission ratio is minimum U). Line L6 shows the relationship when the torque transmission ratio is maximum. Operation is electrically controlled within the area indicated by the diagonal in the figure.

Specifically, the engine rotation changes on line L2 when the throttle opening is fully closed, and on line L4 when it is fully open. That is, the larger the throttle opening, the larger the torque transmission ratio, and the larger the engine rotation, the smaller the torque transmission ratio. For example, consider the case of half-throttle. When half-throttle is applied, line L:' K G increases engine rotation and vehicle speed, and from the point where line JJ3 and line Lt intersect, the torque increases further. The transmission ratio does not become smaller, but increases in proportion to the vehicle speed as the engine speed increases.Then, when the vehicle speed reaches the set value Va, the off-shore speed detection stage 12 explained in FIG.
operates and the torque transmission ratio increases, so line L5
live and move. Therefore, overrun on the output shaft side can be prevented without exceeding military speed Va. Note that although line L5 is shown as a straight line in this graph, in reality, it would appear to be a certain degree of deviation to the right around 1'.

[Brief Description of the Drawings] Fig. 1 is a hydraulic circuit diagram showing one embodiment of the control device of the present invention, Fig. 2 is a sectional view showing a vehicle speed detection means used in the control device of the present invention, and Fig. 3 is a diagram of the present invention. It is a graph showing the relationship between engine rotation and vehicle speed of a continuously variable transmission equipped vehicle equipped with the 'rtrl control device of the invention. 1...Primary pulley 2...Primary cylinder 3...Secondary pulley 4...Secondary cylinder 9...HiI・-≦effect 10...Ratio control.

Claims (1)

[Scope of Claims] 1) A continuously variable buried bale structure that transmits the input/output 1IIllIII, i' and changes the torque transmission ratio to +@1, and this continuously variable speed.・A ratio control valve that adjusts the supply of a hydraulic actuator that changes a given torque transmission ratio and a signal that indicates the running state of the vehicle. and υ16, and the torque transmission ratio is 1/3 times the car.
I 21. In the 1LllI value device of the uninstalled change notification, the above output [111I
(When the speed is increased, the setting is set to 111:L, and the M!f md ratio control pulp is immediately detected to reduce the torque transmission ratio.)
Dai & Kyopo Pittarize J Hiro (
One of the official vessels. 2) The vehicle speed setting means detects that the rotational speed of the output shaft Q) has slowed down to a set value, emits a predetermined signal fluid, and transmits torque from this predetermined No. 18 θa body to the No. 111 ratio control valve. 1. A TLI control device for a continuously variable transmission system, characterized in that the water pressure is increased in the direction of increasing the ratio.