JP6592898B2 - Toroidal continuously variable transmission - Google Patents

Description

  The present invention relates to a toroidal continuously variable transmission that can be used for transmissions of automobiles and various industrial machines.

  Conventionally, a toroidal type continuously variable transmission is known as a transmission constituting an automobile transmission (see, for example, Patent Document 1). In this toroidal type continuously variable transmission, there is a so-called double cavity type in which transmission of power from an input unit to an output unit is divided into two systems provided in parallel with each other. Such a toroidal type continuously variable transmission has been described in many publications and is well known. The basic structure of the toroidal type continuously variable transmission will be described with reference to a side view 8 and a sectional view AA in FIG.

  The toroidal continuously variable transmission 1 includes a pair of input side disks 10a and 10b, an integrated output side disk 11, and a plurality of power rollers 12a and 12b. Of these, the input side disks 10a and 10b are concentrically connected to each other via the input rotation shaft 5 and are coupled so as to freely rotate in synchronization. The output side disk 11 is concentric with the input side disks 10a and 10b between the input side disks 10a and 10b, and can rotate relative to the input side disks 10a and 10b. It is supported. Further, a plurality of each of the power rollers 12a and 12b are provided between the both axial side surfaces of the output side disk 11 and one axial side surface of the both input side disks 10a and 10b (in the case of the illustrated example). 2 pieces in total, 4 pieces in total). The power rollers 12 a and 12 b transmit power between the input disks 10 a and 10 b and the output disk 11 while rotating with the rotation of the input disks 10 a and 10 b.

  The output side disk 11 is rotatably supported at both ends in the axial direction in the casing 13 by a pair of support columns 14 and 14 and a rolling bearing which is a thrust angular ball bearing. Also, yokes 16 and 16 are supported in the vicinity of both end portions of the both columns 14 and 14, respectively. A plurality of trunnions 17a and 17b between the yokes 16 and 16 are swung and axially centered on pivots 18 and 18 provided concentrically with each other at both ends (see FIGS. 8 to 17). Supports displacement in the vertical direction).

  Further, the power rollers 12a and 12b are respectively rotated on the inner side surfaces (surfaces facing each other) of the trunnions 17a and 17b via support shafts 19 and 19 and a plurality of sets of rolling bearings, and the input rotary shaft 5. A slight displacement in the axial direction is supported freely. The peripheral surfaces of the power rollers 12a and 12b are in rolling contact with the axial side surfaces of the input side disks 10a and 10b and the axial side surfaces of the output side disk 11. The rolling contact portions between these surfaces become traction portions that transmit power via traction oil (lubricating oil). Further, a hydraulic pressing device 20 is provided between the proximal end portion of the input rotating shaft 5 and the input side disk 10a on the side close to the engine (left side in FIG. 8), and an appropriate surface pressure is provided to each traction portion. Can be granted.

By the way, the lubricating oil supplied to the power rollers 12a and 12b is stored in an oil pan 101 (see FIG. 9) installed in the lower part of the toroidal type continuously variable transmission 1, and supplied to the power rollers 12a and 12b through the oil supply pipe. The
Conventionally, various proposals have been made on the supply of lubricating oil to the power rollers 12a and 12b of the toroidal-type continuously variable transmission 1 as shown in Patent Documents 1 to 4 below.

In Patent Document 1, in a toroidal-type continuously variable transmission, the supply amount of lubricating oil is determined by measuring the temperature of a rotating body and a rolling surface (traction surface).
Further, in Patent Document 1, the temperature of the lubricating oil that has returned to the lubricating oil reservoir such as an oil reservoir is detected, and the temperature of the rolling surface (traction surface) is calculated based on the temperature, or from the input / output energy difference. A mechanism is described in which the amount of energy converted into heat is determined, the temperature of the rolling surface (traction surface) is calculated based on the amount of heat, the amount of lubricating oil is determined, and lubrication is performed from the oil supply hole at the tip of the disk.

Patent Document 2 describes a method for determining the amount of lubricating oil only by torque generated by opening and closing a throttle valve.
Patent Document 3 describes a method for determining a lubricating flow rate based on oil temperature.
Patent Document 4 describes a method of controlling the lubrication from the post in accordance with the operating conditions.

Japanese Patent No. 3531607 JP-A-8-28646 JP 2002-349660 A JP 2003-207011 A

However, the lubrication methods described in the above Patent Documents 1 to 4 have the following problems.
The method of measuring the temperature of the rotating body or rolling surface (traction surface) of Patent Document 1 needs to employ a contact-type sensor. In the case of this contact sensor, there is a problem that there is a risk of wear and durability is lowered.

On the other hand, in the case of a non-contact type sensor, there is a problem that the measurement cannot be performed accurately in an environment where the lubricant is scattered, and the non-contact type sensor is brought close to the sensor, resulting in an increase in size.
Furthermore, if an oil supply hole is provided at the tip of the disk, there is a problem that durability is lowered.

In addition, the method of determining the amount of lubricating oil only by the torque by opening and closing the throttle valve in Patent Document 2 does not take into account the temperature increase due to the rotational speed, so that the amount of oil is small or large, and the appropriate amount of lubricating oil can be adjusted. Can not.
Further, in the method of determining the lubrication flow rate based on the oil temperature in Patent Document 3, since the temperature of the power roller is not known only by the oil temperature, poor lubrication of the traction surface occurs.
Further, even in the method of controlling the lubrication from the post in accordance with the operation conditions of Patent Document 4, the actual temperature of the power roller is not known, so that the best lubrication cannot be performed.
Also, none of the above Patent Documents 1 to 4 considers the power change for a predetermined time when determining the supply amount of the lubricating oil.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a toroidal continuously variable transmission that can suppress a gross slip due to excessive engine torque and has excellent durability.

In order to achieve the above object, the present onset Ming, power sandwiched respective inner surfaces each other and facing the input side disk and the output side disk rotatably supported in a state allowed each other between these two discs in the toroidal type continuously variable transmission that includes a roller, when the estimated temperature of the power roller exceeds a threshold, a controller for controlling the operation of reducing the gross slip, by the controller, the power rollers Is estimated based on a measured temperature value of the lubricating oil in the oil pan for storing lubricating oil to be supplied to the power roller, and an average value or an integrated value of the transmission power of the power roller. The supply amount of the lubricating oil is adjusted based on the estimated temperature value, and the controller controls the input / output rotational speed of the toroidal-type continuously variable transmission, It characterized that you calculate the transmission power of the power rollers with a differential pressure of the hydraulic chamber of the actuator for displacing the trunnions supporting the power rollers.

  In the present invention, when the estimated temperature value of the power roller exceeds the threshold value, the controller performs an operation of reducing gross slip that causes excessive slip between the power roller and the disk at an appropriate timing.

In the above configuration of the present invention, the estimated temperature value of the power roller is calculated by the controller from the measured temperature value of the lubricating oil in the oil pan for storing the lubricating oil supplied to the power roller and the average value or integral of the transmission power of the power roller. is estimated based on the value, the supply amount of the lubricating oil on the basis of the estimated temperature of the power rollers Ru is adjusted.

  According to such a configuration, the temperature of the power roller is estimated based on the measured temperature value of the lubricating oil in the oil pan that stores the lubricating oil supplied to the power roller, and the average value or integrated value of the transmission power of the power roller. Since the supply amount of the lubricating oil is adjusted based on the estimated temperature value of the power roller, the amount of lubricating oil supplied to the power roller is optimized based on the accurate estimated temperature value of the power roller, and excessive engine torque It is possible to suppress the gross slip due to the occurrence of.

In another configuration of the present invention, the controller estimates the temperature value of the power roller from the temperature measurement value outside the casing housing the toroidal-type continuously variable transmission and the average value or integral of the transmission power of the power roller. be estimated based on the value, the supply amount of the lubricating oil on the basis of the estimated temperature of the power rollers Ru is adjusted.

  According to such a configuration, the temperature of the power roller is estimated based on the temperature measurement value outside the casing housing the toroidal-type continuously variable transmission, and the average value or integral value of the transmission power of the power roller, Since the supply amount of the lubricating oil is adjusted based on the estimated temperature value of the power roller, the amount of lubricating oil supplied to the power roller is optimized based on the accurate estimated temperature value of the power roller by a simple method. Gloss slip due to generation of engine torque can be suppressed.

According to the present invention , the operation of reducing the gross slip that causes excessive slip between the power roller and the disk is performed at an appropriate timing.
In particular , according to the first aspect of the present invention, the amount of lubricating oil supplied to the power roller can be optimized, and gross slip caused by excessive engine torque can be suppressed. A transmission can be provided. Further, the temperature of the power roller can be accurately estimated based on the temperature of the lubricating oil in the oil pan, the measured value outside the casing, and the average value or integrated value of the power transmitted by the power roller.
Furthermore, according to the second aspect of the present invention, since no temperature sensor is installed in the toroidal-type continuously variable transmission, the cost is reduced and the installation location is not required, leading to a reduction in size.

1 is a block diagram showing a toroidal continuously variable transmission according to a first embodiment of the present invention. It is a flowchart which shows the operation | movement procedure of the toroidal type continuously variable transmission which concerns on the 1st Embodiment of this invention. It is sectional drawing which shows the principal part of the toroidal type continuously variable transmission which concerns on the 2nd Embodiment of this invention with a temperature sensor. It is a flowchart which shows the operation | movement procedure of the toroidal type continuously variable transmission which concerns on the 2nd Embodiment of this invention. It is a flowchart which shows the operation | movement procedure of the toroidal type continuously variable transmission which concerns on the 3rd Embodiment of this invention. It is a flowchart which shows the operation | movement procedure of the toroidal type continuously variable transmission which concerns on the 4th Embodiment of this invention. It is a flowchart which shows the operation | movement procedure of the toroidal type continuously variable transmission which concerns on the 5th Embodiment of this invention. It is a side view which shows an example of the conventional toroidal type continuously variable transmission. It is AA sectional drawing in FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
The structure of the toroidal-type continuously variable transmission 1 according to the first embodiment of the present invention (the invention according to claims 1 and 2) is the same as that shown in FIGS. 8 and 9 is common to the conventional toroidal-type continuously variable transmission, the same reference numerals are given to the common parts, and description thereof is omitted or simplified.

  In the first embodiment of the present invention, as shown in FIG. 1, the temperature sensor 104 is installed inside an oil pan 101 that stores lubricating oil. The temperature sensor 104 measures the temperature of the lubricating oil in the oil pan 101, and the measured temperature of the lubricating oil is used to estimate the base temperature of the power rollers 12a and 12b.

  Further, the toroidal continuously variable transmission 1 includes a controller 103 that controls the operation of the toroidal continuously variable transmission 1. The controller 103 calculates power using the input / output rotational speed of the toroidal-type continuously variable transmission 1 and the differential pressure in the hydraulic chamber of the actuator that displaces the trunnions 17a and 17b, and further calculates an average value of power for a predetermined time or The temperature of the power rollers 12a and 12b is estimated from the integrated value in consideration of the use conditions. Thereby, the temperature of the power rollers 12a and 12b is estimated with high accuracy.

At this time, the relationship between the power, the amount of lubricating oil supplied, the temperature of the lubricating oil in the oil pan 101, and the temperature of the power rollers 12a and 12b is determined in advance by creating a map (table) through experiments. The supply amount of the lubricating oil is controlled by adjusting the opening degree of the lubricating oil amount control valve 102 based on the lubricating oil amount.
According to this embodiment, the amount of lubricating oil supplied to the power rollers 12a and 12b is optimized by adjusting the amount of lubricating oil based on the estimated accurate temperature of the power rollers 12a and 12b. Gloss slip due to generation of torque can be suppressed.

FIG. 2 is a flowchart showing an operation procedure of the toroidal continuously variable transmission based on the accurate temperatures of the power rollers 12a and 12b estimated according to the first embodiment of the present invention.
First, after the start, the estimated temperatures of the power rollers 12a and 12b are calculated (step S1), and when this temperature becomes higher than the threshold value S, the engine torque is limited and reduced (step S2). At this time, the threshold value S is an upper limit temperature at which torque can be transmitted by the power rollers 2a and 12b.
When the estimated temperature of the power rollers 12a and 12b is equal to or lower than the threshold value S, the process is terminated without limiting the engine torque.
When the input torque of the engine increases, the heat generated at the contact point between the disk and the power rollers 12a and 12b increases, and the limit traction coefficient decreases and slipping easily occurs. In this embodiment, gross slip can be prevented by limiting the engine torque so that a large torque is not input to the transmission.

In the second embodiment of the present invention (embodiment of the invention according to claims 1 and 3), as shown in FIG. 3A, the temperature sensor 105 is a casing 13 that houses the toroidal-type continuously variable transmission 1. It is installed on the top surface. This temperature sensor 105 measures the temperature of the casing 13 instead of the temperature of the lubricating oil.
In the toroidal continuously variable transmission 1, the operation is controlled by a controller 103 (not shown) provided in the toroidal continuously variable transmission 1 as in FIG. 1, and lubrication is performed by a lubricating oil amount control valve 102. Oil supply is adjusted.

As shown in FIG. 3B, the temperature sensor 106 is installed on the side surface of the casing 13 that houses the toroidal-type continuously variable transmission 1, and instead of measuring the temperature of the lubricating oil in the oil pan, Any part outside 13 can be used for temperature measurement.
In this embodiment, since no temperature sensor is installed inside the toroidal type continuously variable transmission 1, the cost is reduced and the installation location is not required, leading to a reduction in the size of the toroidal type continuously variable transmission 1.

FIG. 4 is a flowchart showing an operation procedure of the toroidal continuously variable transmission based on the accurate temperatures of the power rollers 12a and 12b estimated according to the second embodiment of the present invention.
First, after the start, the estimated temperatures of the power rollers 12a and 12b are calculated (step S3), and when the temperature becomes higher than the threshold value S, the accelerator opening is smoothed (relaxed) (step S4). At this time, the threshold value S is an upper limit temperature at which torque can be transmitted by the power rollers 2a and 12b.
When the estimated temperature of the power rollers 12a and 12b is equal to or lower than the threshold value S, the accelerator opening is not smoothed (it is not loosened), and the process is terminated.
When the accelerator is stepped on suddenly, the input torque of the engine increases abruptly, heat generation at the contact point between the disk and the power rollers 12a and 12b increases, the limit traction coefficient decreases, and slipping easily occurs. In this embodiment, by slowing (relaxing) the accelerator opening, a sudden temperature change of the power rollers 12a and 12b can be prevented to prevent gross slip.

FIG. 5 is a flowchart showing the operation procedure of the toroidal continuously variable transmission based on the accurate temperatures of the power rollers 12a and 12b estimated according to the third embodiment of the present invention.
First, after the start, the estimated temperatures of the power rollers 12a and 12b are calculated (step S5), and when this temperature becomes higher than the threshold value S, the shift speed is limited (step S6). At this time, the threshold value S is an upper limit temperature at which torque can be transmitted by the power rollers 12a and 12b. Further, when the estimated temperature of the power rollers 12a and 12b is equal to or lower than the threshold value S, the process ends without limiting the speed change speed.
Since the offset amount increases as the shift speed increases, the input torque increases rapidly, and heat generation at the contact points between the input side disks 10a and 10b and the output side disk 11 and the power rollers 12a and 12b increases. The traction coefficient decreases and slipping easily occurs.
In this embodiment, by limiting the shift speed, it is possible to prevent a gross slip by preventing a rapid temperature change of the power rollers 12a and 12b.
The method for limiting the shift speed is, for example, a method of reducing the number of output steps per unit time when shift control is performed by a step motor.

FIG. 6 is a flowchart showing the operation procedure of the toroidal continuously variable transmission based on the accurate temperature of the power rollers 12a and 12b estimated according to the fourth embodiment of the present invention.
First, after the start, the estimated temperatures of the power rollers 12a and 12b are calculated (step S7), and when this temperature becomes higher than the threshold value S, the amount of lubricating oil on the traction surface is increased (step S8). At this time, the threshold value S is an upper limit temperature at which torque can be transmitted by the power rollers 12a and 12b. Further, when the estimated temperature of the power rollers 12a and 12b is equal to or lower than the threshold value S, the process is finished without increasing the amount of lubricating oil on the traction surface.
In this embodiment, when the input torque suddenly increases and the heat generation at the contact points between the input side disks 10a and 10b and the output side disk 11 and the power rollers 12a and 12b is large, the amount of lubricating oil on the traction surface is reduced. Since it increases, the rapid temperature change of power roller 12a, 12b can be prevented, and gross slip can be prevented.
The method of increasing the amount of lubricating oil is, for example, a method of increasing the original pressure of the lubricating pressure when the original pressure of the lubricating pressure can be controlled. Moreover, when it has the flow control valve which can control the amount of lubricating oil directly, control which opens the opening degree of a flow control valve is performed.

FIG. 7 is a flowchart showing an operation procedure of the toroidal continuously variable transmission based on the accurate temperature of the power rollers 12a and 12b estimated according to the fifth embodiment of the present invention.
First, after the start, the estimated temperatures of the power rollers 12a and 12b are calculated (step S9), and when this temperature becomes higher than the threshold value S, the clutch pressure is limited (step S10). At this time, the threshold value S is an upper limit temperature at which torque can be transmitted by the power rollers 12a and 12b. When the estimated temperature of the power rollers 12a and 12b is equal to or lower than the threshold value S, the process ends without limiting the clutch pressure.
In this embodiment, when the input torque suddenly increases and the heat generation at the contact points between the input side disks 10a and 10b and the output side disk 11 and the power rollers 12a and 12b is large, the clutch engagement pressure is limited. Even when a large torque is input, the clutch slips, and a sudden temperature change of the power rollers 12a and 12b can be prevented to prevent a gross slip.
In general, in the case of a transmission of an automobile, the clutch engagement pressure is often controlled by a control valve (solenoid valve). Therefore, for example, a method for limiting the clutch engagement pressure is to set a target signal to the control valve below a certain value. Limit to.

  In addition, each detection value by the temperature sensors 104, 105, and 106 used in each of the above embodiments is transmitted to the controller 103 shown in FIG. 1, and the flow shown in each embodiment is realized by the controller 103.

  In addition to the above embodiments, if the temperature estimation value of the power rollers 12a and 12b exceeds the threshold value S, the specific method is not limited to the gloss slip. It doesn't matter.

  The present invention can be applied to a full toroidal continuously variable transmission as well as a half toroidal continuously variable transmission such as a single cavity type or a double cavity type.

DESCRIPTION OF SYMBOLS 1 Toroidal type continuously variable transmission 10a, 10b Input side disk 11 Output side disk 12a, 12b Power roller 13 Casing 16 Yoke 17a, 17b Trunnion 101 Oil pan 103 Controller

Claims (2)

In a toroidal continuously variable transmission including an input side disk and an output side disk that are rotatably supported in a state where the respective inner side surfaces face each other, and a power roller sandwiched between these two disks,
A controller for controlling an operation to reduce gross slip when the estimated temperature value of the power roller exceeds a threshold value;
According to the controller, the estimated temperature value of the power roller is based on a measured temperature value of the lubricating oil in an oil pan for storing lubricating oil to be supplied to the power roller, and an average value or an integrated value of the transmission power of the power roller. And the supply amount of the lubricating oil is adjusted based on the estimated temperature value of the power roller,
The controller calculates the transmission power of the power roller using the input / output rotation speed of the toroidal-type continuously variable transmission and the differential pressure in the hydraulic chamber of the actuator that displaces the trunnion that supports the power roller. Toroidal-type continuously variable transmission. In a toroidal continuously variable transmission including an input side disk and an output side disk that are rotatably supported in a state where the respective inner side surfaces face each other, and a power roller sandwiched between these two disks,
A controller for controlling an operation to reduce gross slip when the estimated temperature value of the power roller exceeds a threshold value;
By the controller, the estimated temperature value of the power roller is estimated based on a measured temperature value outside the casing housing the toroidal-type continuously variable transmission, and an average value or integral value of the transmission power of the power roller, The supply amount of lubricating oil supplied to the power roller is adjusted based on the estimated temperature value of the power roller ,
The controller calculates the transmission power of the power roller using the input / output rotation speed of the toroidal-type continuously variable transmission and the differential pressure in the hydraulic chamber of the actuator that displaces the trunnion that supports the power roller. Toroidal-type continuously variable transmission.

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