JPS5881258A - Controller for v-belt type stepless speed change gear - Google Patents

Abstract

PURPOSE:To enable the safe running at the fault by controlling such that a line pressure regulating valve and a speed change control valve are brought to the specific state when the torque motors for them are not operating. CONSTITUTION:The speed change gear is variable in a V-shaped groove gap by the amount of the pressurized oil to be fed into each cylinder chambers 4c, 5c in drive and inverted pulleys 4, 5 where said controller is equipped with a line pressure regulating valve 11 and a speed change control valve 12 for regulating the distribution of the pressurized oil to each chambers 4c, 5c. When the torque motors 16, 22 for controlling each valves 11, 12 are in fault, the rods 16a, 22a are moved together with spools 14, 18 to the left and right through spring 16b, 19. The oil pressure in a port 13d or the line pressure in an oil path 7 is brought to the maximum while the oil pressure in an oil path 20 or the oil pressure in the cylinder chamber 4c is brought to zero. Consequently a transmission device 1 can be transferred to the state of highest reduction ratio.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control device for a V-belt continuously variable transmission.

As a control device for a V-belt type continuously variable transmission that transmits power by wrapping a V-belt between two pulleys whose V-shaped groove interval is variable according to the oil pressure in the pulley cylinder chamber,
There is a combination of a hydraulic control device and an electronic control device. In one example of such a conventional control device, the valves (line pressure regulating valve, speed change control valve, etc.) that adjust the hydraulic pressure supplied to the cylinder chambers of both boobies are controlled by a torque motor operated by an electronic control device. It was meant to be controlled.

However, in the conventional V-belt continuously variable transmission control device as described above, there are insufficient countermeasures in the event of failures such as failure of the electronic control device, failure of the torque motor, or disconnection of wiring. If the above failure occurs, the line pressure will no longer be generated, or (and) the reduction ratio will be at its minimum, causing the vehicle equipped with the V-belt continuously variable transmission to completely fail. There was a problem that it became impossible to drive. It would be extremely dangerous if the above-mentioned problems occurred at intersections or railroad crossings.

The present invention has been made by focusing on the above-mentioned problems in conventional control devices for V-belt type continuously variable transmissions.
The purpose of this invention is to solve the above-mentioned problems by maximizing the line pressure and maximizing the reduction ratio when a failure occurs in the electronic control device or the like.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to FIGS. 1 to 3 of the accompanying drawings showing embodiments thereof.

First, the configuration will be explained.

A first embodiment of the present invention is shown in FIG. V wrapped around pulley 5 and both pulleys 4 and 5
It consists of a belt 6. The drive pulley 4 is connected to the drive shaft 2
A fixed conical plate 4a is fixed to the fixed conical plate 4a, and a V-shaped pulley groove is formed by opposing the fixed conical plate 4a.
It consists of a movable conical plate 4b that is movable in the axial direction on the top thereof. The driven pulley 5 includes a fixed conical plate 5a fixed to the driven shaft 3, and a V
It consists of a movable conical plate 5b that forms a letter-shaped pulley groove and is movable on the driven shaft 3 by the hydraulic pressure acting on the driven pulley cylinder chamber 5C. It is larger than the pressure receiving area of the pulley cylinder chamber 5C. The rotation ratio between the drive shaft 2 and the driven shaft 3 of such a V-belt type transmission device 1 is as follows.

The movable cones 7, 1, 4, . .

It is determined depending on the comparison with the thrust force acting on the plate 5b.

In other words, the radius of the contact position of the pulley on the side with a larger thrust with the V-belt 6 becomes larger, and the radius of the contact position with the V-belt 6 of the pulley on the side with a smaller thrust becomes smaller. Therefore,
Driven pulley cylinder chamber 5C and driving pulley cylinder chamber 4
By controlling the oil pressure of C, the one rotation ratio can be changed continuously.

The driven pulley cylinder chamber 5C is connected to an oil passage 7, into which oil sucked by a pump 10 from a tank 8 through a filter 9 is discharged. The oil passage 7, which is a line pressure circuit, is also led to a line pressure regulating valve 11 and a speed change control valve 12. The line pressure regulating valve 11 has five bows) 13a, , 13b, 13c, 13d and 13e.
a spool 14 having three lands 14a, 14b and 14c fitted in the valve hole 13;
It consists of. Boat 13b and boat 13d (pilot boat) are connected to oil line 7, and boats 13a, 13c and 13e are drain boats.

Land 14a and land 14b have the same diameter, and land 1
4c has a smaller diameter than these. An O-ring 15 is interposed on the open end side of the valve hole 13, and a torque motor 16 is screwed into the valve hole 13. The rod 16a of the torque motor 16 is pressed by the spring tab and exerts force on the spool 14, but the torque motor 16 is of a suction type, and a suction force corresponding to the current supplied to the torque motor 16 acts on the rod 16a. So, depending on the current, the rod lea
The imposition of will reduce the power.

The speed change control valve 12 includes boats 17a, 17b, 17c,
A spool 1 having a valve hole 17 having 17d and 17e and lands 18a and 18b fitted into the valve hole 17.
8 and a spring 19 that pushes the spool 18 toward the open end of the valve hole 17. The boat 17c is connected to the drive pulley cylinder chamber 4C via the oil passage 2o, and the boat 17d is connected to the oil passage 7.
.

17b and 17e are drain boats. Land 18
a and land tab have the same diameter. When the inner end of land 18a opens boat 17b slightly, land 1
The inner end of 8b is also positioned to open the boat 17b slightly. There is an O-ring 2 on the open end side of the valve hole 17.
A torque motor 22 is screwed in with 1 interposed therebetween. The torque motor 22 is in contact with the end of the spool 18 and applies a pressing force to it.
2 is an extrusion die, and the pressing force of the rod 22a increases in proportion to the current supplied to the torque motor 22. Operating current for torque motor 16 and torque motor 22 is supplied from electronic control unit 25 via line 23 and line 24, respectively.

The electronic control device 25 includes an engine rotation sensor 26, a throttle opening sensor, or an intake pipe negative pressure sensor 2'7.
Position sensor 28 and 7'-rotation sensor 2
9, a signal related to engine speed, a signal related to throttle opening or intake pipe negative pressure, and a shift lever.
A signal regarding the position of the driven pulley 5 and a signal regarding the rotational speed of the driven pulley 5 are input. Based on these input signals, the electronic control unit 25 outputs a signal to the line 24 for setting the reduction ratio so that the engine operating state with the lowest fuel consumption rate is achieved, and also changes the engine output. A signal for setting the line pressure to the minimum required oil pressure according to the torque and reduction ratio is output to the line 23. However, since the detailed structure and operation of this electronic control device 25 are not directly related to the present invention, a description thereof will be omitted.

Next, the effect will be explained.

The spool 14 of the line pressure regulating valve 11 receives a rightward force in the figure from the rod 16a of the torque motor 6, and the land 1
A force directed to the left in the figure due to the hydraulic pressure of the boat (pilot boat) (that is, the hydraulic pressure of the oil passage 7) acting on the difference in area between the boats 4b and 14c is acting, and the oil passage 7 is adjusted so that these two forces are balanced. The oil is drained via bows 13b and 13c. Therefore, the oil pressure (line pressure) of oil passage 7
The pressing force of the rod 16 & of the torque motor 6 is a value proportional to the force. Since the pressing force of the rod 16a of the torque motor 6 is inversely proportional to the current supplied from the line 23 as described above, the line pressure is also inversely proportional to this electric current.

The line pressure of the oil passage 7 is supplied to the driven pulley cylinder chamber 5C and the speed change control jF';'-to 17's.

A rightward force from the rod 22a of the torque motor 22 and a leftward force from the spring 19 act on the spool 18 of the speed change control valve.
The position of the spool 18 is determined depending on the size. If the force from the torque motor 22 is greater than the force of the spring 19, the boat 17d is opened and drained.
Since port 7b tends to be closed, the oil pressure of port 17c (
In other words, the oil pressure in the oil passage 20 becomes high (in the highest case,
conversely, when the force of the torque motor 22 is smaller than the force of the spring 19, the oil pressure in the oil passage 20 becomes low. Since the force of torque motor 22 is proportional to the current supplied from line 24, the oil pressure in oil passage 20 is also proportional to this current.

Since the oil passage 20 communicates with the drive pulley cylinder chamber 4C, the oil pressure in the drive pulley cylinder chamber 4C is controlled by the current in the line 24. Line pressure is always supplied to the driven pulley cylinder chamber 5C, so the smaller the oil pressure in the drive pulley cylinder chamber 4C, the larger the reduction ratio becomes, and the larger the oil pressure in the drive pulley cylinder room 4C, the smaller the reduction ratio becomes. (As described above, the area of the driving pulley cylinder chamber 4C is larger than the area of the driven pulley cylinder chamber 5C), therefore, the reduction ratio is determined by the current in the line 24. The current in line 24 is continuously controlled by electronic control unit 25 to a predetermined value.

During the operation as described above, if the electronic control unit 25 malfunctions, the line 2
When the torque motors 16 and 22 become inoperable due to disconnection of the V-belt type continuously variable transmission or failure of the torque motor 16 or 22 itself, the control device of this V-belt type continuously variable transmission operates as follows. First, when the torque motor 16 for the line pressure regulating valve 11 becomes inactive, the suction force of the torque motor 16 becomes 0, so the rod 16a pushes the spool 14 with maximum force (that is, the set load of the spring 16b). This pressing counteracts the force, and the hydraulic pressure acting on the bow 13d increases, and the line pressure regulating valve 11 reaches a balanced state. Therefore, the oil pressure of the port 13d, that is, the line pressure of the oil passage 7, becomes the highest pressure.

When the torque motor 22 for the speed change control valve 12 becomes inactive, the pressing force of the rod 22a is lost, so the spool 18 of the speed change control valve 12 is pushed by the spring 19 and moves to the left. Therefore, the boat 17d is blocked by the land 18b, and the boat 17c is blocked by the drain port 17.
It communicates with b.

Therefore, the oil pressure in the oil passage 20, that is, the oil pressure in the drive pulley cylinder chamber 4C becomes O. At this time, line pressure is acting on the driven pulley cylinder chamber 5C, so that the belt type transmission device 1 is in a state with the largest reduction ratio.

After all, when either or both of the torque motor 16 and the torque motor 22 become inactive, the following operation is possible.

When the torque motor 16 is in the non-operating state, the line pressure is simply in a high pressure state, and the vehicle can travel while operating the shift control valve 12 normally and changing gears.

When only the torque motor 22 becomes inactive,
It is possible to drive with the largest reduction ratio. The line pressure is at a normal value.

When the torque motor 16 and the torque motor 22 are simultaneously inactive, the reduction ratio becomes the largest, the line pressure becomes the highest, and the vehicle can travel in the same manner as described above.

Therefore, no matter what kind of failure occurs in the control device, it is possible to at least travel enough to escape from a dangerous place such as an intersection.

A second embodiment of the present invention is shown in FIG. 2, and this second embodiment uses an extrusion type torque motor 1B' in place of the torque motor 16 of the first embodiment. Correspondingly, the spool 14 of the line pressure regulating valve 11' is arranged in the opposite direction to that in the first embodiment. The spool 14 pumps the oil in the oil path 7 so that the leftward force of the spring 30 in the figure balances the force due to the hydraulic pressure of 13b'.
Drain through 13d' and 13c'. With this configuration, the first thing is that the hydraulic pressure (line pressure) in the oil passage 7 can be obtained in proportion to the pressing force of the torque motor 16'.
This is similar to the embodiment. The structure and operation of the speed change control valve 12 and the like are the same as those in the first embodiment, so a description thereof will be omitted.

As is clear from the first and second embodiments described above, the spool 14.1 of the line pressure regulating valve 11.11'
The torque motor that drives 4' can be either an extrusion type or a suction type by arranging the spring and boat so that the line pressure is highest when the torque motor is inactive. Although omitted, the springs and boats of the speed change control valve 12 are arranged so that when the torque motor is not in operation, the oil pressure in the driven pulley cylinder chamber 5C is the highest and the oil pressure in the drive pulley cylinder chamber 4C is the lowest. By doing so, a suction type torque motor can be used in place of the extrusion type torque motor used in the first embodiment.

FIG. 3 shows a third embodiment of the present invention. This third embodiment includes the speed change control valve 12 and each pulley cylinder chamber 4C25C.
In this example, the oil passage 7
(line pressure) at the center boat 17c' of the speed change control valve 12.
connected to the valve hole 17' and the land 18a of the spool 18,
While draining the oil into the boats 17a' and 178' through the gap with the boats 17b' and 17d'
From the oil passage 31.20 to each pulley cylinder chamber 5C14.
The configuration is such that hydraulic pressure is distributed to C. In addition, valve hole 17
The diameter of the space between the boats 17b' and 17d' is slightly larger than that of the lands 18a and 18b of the spool 18, and is almost closed by the lands 18a and 18b. The rest of the configuration is the same as that of the first embodiment, so the explanation will be omitted.Even if the configuration is 0 or more, when the torque motor 16, 22 is not operating, the force of the spring 19 is applied to the driven pulley cylinder chamber. By making the oil pressure of the drive pulley cylinder chamber 4C the highest and making the oil pressure of the drive pulley cylinder chamber 4C the lowest, the same operation and effect as in the first embodiment described above can be obtained.

As explained above, according to the present invention, when the line pressure regulating valve torque motor becomes inactive, the line pressure regulating valve enters the pressure regulating state that maximizes the line pressure, and the transmission control valve torque motor becomes inoperative. When the motor is in a non-operating state, the speed change control valve sets the hydraulic pressure in the driven pulley cylinder chamber to the highest level and the hydraulic pressure in the driving pulley cylinder chamber to the lowest level, so that the electronic control device, wiring, etc. Even in the event of a breakdown, it is possible to continue driving, allowing the vehicle to escape from a dangerous situation and improving safety.

[Brief explanation of drawings]

FIG. 1 shows a first embodiment of the invention, FIG. 2 shows a second embodiment of the invention, and FIG. 3 shows a third embodiment of the invention. L/No./V-belt type transmission device, 2/Fist/drive shaft, 3/Fist/
・Followed shaft, 4: Drive pulley, 4C: Drive pulley cylinder chamber, 5: Driven pulley, 5C: φ driven pulley cylinder chamber, 6: V-belt, 7: Oil path, 81
1. Tank, 9. Filter, 10. Pump, 11. φ line pressure regulating valve, 12. Speed control valve.
13φ...Valve hole, 14---Spool, 15---0 ring, 16Φ・-Torque motor, 17 Fist IIe valve hole, 1
8...6 Subur, 19...Spring, 20...
Oil passage, 21 fist 110 ring, 22... fist torque motor, 23 fist... line, 24--- line, 25-... electronic control unit, 26... engine rotation sensor, 27... throttle opening degree sensor or intake pipe negative pressure sensor, 28--
- Position sensor, 29Φ・O boule rotation sensor, 30・spring, 31 also...oil path. Patent applicant: Nissan Motor Co., Ltd. Representative Patent attorney: Toshiyuki Miyauchi

Claims (1)

[Claims] This is a control device for a V-belt type continuously variable transmission that transmits power by winding a V-belt between a driving pulley and a driven pulley, whose V-shaped groove interval is variable according to the oil pressure in the pulley cylinder chamber, and which adjusts line pressure. A line pressure regulating valve that adjusts pressure, and a speed change control valve that adjusts the distribution of hydraulic pressure to a driving pulley cylinder chamber and a driven pulley cylinder chamber, are respectively operated by an electronic control device for a torque motor and a speed change control valve. In a control device for a V-belt continuously variable transmission that is controlled by a torque motor, when the torque motor for the line pressure regulating valve becomes inactive, the line pressure regulating valve
The valve is in a pressure regulating state that makes the line pressure the highest, and when the torque motor for the speed change control valve is in a non-operating state, the speed change control valve sets the oil pressure in the driven pulley cylinder chamber to the highest and also increases the oil pressure in the drive pulley cylinder chamber. A control device for a V-belt continuously variable transmission characterized by being in the lowest state.