JP5934034B2 - Control device for continuously variable transmission mechanism - Google Patents

Description

  The present invention relates to a control device for a continuously variable transmission mechanism, such as a toroidal type, capable of changing a transmission ratio steplessly, and more particularly, to a control device capable of suppressing a temperature increase of the continuously variable transmission mechanism.

  Conventionally, a toroidal-type continuously variable transmission mechanism including a rolling element (roller) that frictionally rolls between an input-side disk and an output-side disk, and a belt including an endless belt bridged between a driving pulley and a driven pulley. There is a continuously variable transmission mechanism that can change the gear ratio steplessly, such as a continuously variable transmission mechanism. In such a continuously variable transmission mechanism, for example, in a toroidal-type continuously variable transmission mechanism, the temperature of the rolling surface (toroidal surface) on which the roller frictionally rolls during operation and hydraulic oil (lubricating oil) flowing through the continuously variable transmission mechanism If the temperature rises excessively, the loss of thermal energy becomes significant, leading to a decrease in power transmission efficiency, or deterioration of each part and a decrease in durability. Therefore, it is necessary to reduce energy loss by suppressing the temperature rise of each part of the continuously variable transmission mechanism such as a toroidal surface during operation and hydraulic oil.

  In relation to this, Patent Document 1 describes a control device including means for suppressing a temperature increase of a belt-type continuously variable transmission. This control device is a control device that controls the primary pulley and the secondary pulley so that the gear ratio of the belt-type continuously variable transmission becomes the target gear ratio, and the belt is determined from the relationship between the gear ratio and the rotation speed of the primary pulley. And controlling the target gear ratio of the continuously variable transmission based on the estimated temperature.

  In the control device for the belt-type continuously variable transmission mechanism described in Patent Document 2, when the temperature of the lubricating oil in the belt-type continuously variable transmission is equal to or higher than a threshold at which the lubricating oil interferes with the belt, the transmission ratio is set. It is configured to shift down to the low speed side. Thus, the stirring resistance of the lubricating oil by the belt is reduced to prevent the oil temperature from rising.

Japanese Patent No. 4212445 JP 2006-336790 A

  However, the control device for the belt-type continuously variable transmission mechanism described in Patent Document 1 only performs control for switching the target gear ratio when the temperature of the continuously variable transmission mechanism is high. Therefore, with this control, it is not possible to suppress the temperature rise in consideration of the power transmission efficiency of the continuously variable transmission mechanism, heat loss energy, and the like. Therefore, there is a problem that the temperature increase of the continuously variable transmission mechanism cannot always be effectively suppressed.

  Further, in the control device for the belt type continuously variable transmission mechanism described in Patent Document 2, the control is performed on the condition that the belt stirs the oil when the primary pulley comes into contact with the oil surface and takes the high ratio. Is. Therefore, only control (downshift) for changing the gear ratio to the low side can be selected as control for suppressing the temperature increase of the continuously variable transmission mechanism. In addition, this control can suppress the temperature rise caused by the stirring resistance of the oil in the transmission, but the power transmission elements (rollers, pulleys, etc.) of the continuously variable transmission mechanism are immersed in the oil in the casing of the transmission. If it is not necessary to consider the oil agitation resistance, it is not possible to suppress the temperature increase of the continuously variable transmission mechanism.

  The present invention has been made in view of the above points, and an object thereof is to provide a continuously variable transmission mechanism and a control device for a continuously variable transmission mechanism that can effectively suppress the temperature rise of hydraulic oil with simple control. It is in.

  In order to solve the above problems, the present invention is configured as follows.

  The control device of the continuously variable transmission mechanism according to the present invention changes the speed ratio steplessly by the transmission elements (51, 52, 53) that transmit the driving force between the input element (2) and the output element (3). The relationship between the possible continuously variable transmission mechanism (5), the temperature estimation means (14) for estimating the temperature of the continuously variable transmission mechanism (5), and the speed ratio and power transmission efficiency of the continuously variable transmission mechanism (5) The speed of the continuously variable transmission mechanism (5) when it is determined that the stored temperature (TS) stored and the estimated temperature (TS) by the temperature estimating means (14) is higher than the predetermined temperature (T0). A target speed ratio changing means (14) for changing the target speed ratio of the continuously variable transmission mechanism (5) to a speed ratio having a higher power transmission efficiency than the current one based on the relationship between the ratio and the power transmission efficiency. It is characterized by.

  According to the control device for a continuously variable transmission mechanism according to the present invention, when it is determined that the estimated temperature by the temperature estimation means is higher than a predetermined temperature, the speed ratio of the continuously variable transmission mechanism and the power transmission efficiency are Based on the relationship, the speed ratio (ratio) of the continuously variable transmission mechanism is changed to a speed ratio with higher power transmission efficiency, thereby reducing the heat loss energy caused by the continuously variable transmission mechanism and increasing the temperature of the continuously variable transmission mechanism. Can be suppressed. As a result, it is not necessary to transiently reduce the power transmission capacity (transmission torque capacity) of the transmission including the continuously variable transmission mechanism, and the temperature increase of the continuously variable transmission mechanism is effectively prevented without causing a decrease in driving force. be able to.

  In particular, here, when it is determined that the temperature of the continuously variable transmission mechanism is high, the speed ratio of the continuously variable transmission mechanism is not simply changed, but based on the relationship between the speed ratio and the power transmission efficiency, The speed ratio is changed so as to increase the transmission efficiency. This makes it possible to effectively suppress the temperature rise of each part of the continuously variable transmission mechanism and hydraulic oil during operation compared to the prior art, while maintaining relatively simple control, and effectively reducing the loss energy. Can be reduced.

  In the control device for a continuously variable transmission mechanism, the continuously variable transmission mechanism (5) is a toroidal continuously variable transmission mechanism including a transmission element (51, 52, 53) for transmitting a driving force by friction. The estimating means (14) may estimate the temperature of the continuously variable transmission mechanism (5) based on the temperature (t) of the hydraulic oil flowing through the continuously variable transmission mechanism (5).

  In the toroidal type continuously variable transmission mechanism, the relationship between the speed ratio and the power transmission efficiency is such that the power transmission efficiency gradually increases and the power transmission efficiency gradually decreases as the difference with respect to the intermediate speed ratio (intermediate ratio) increases. There are two areas. For this reason, when performing control to change the target speed ratio to a speed ratio with higher power transmission efficiency than the current speed based on the relationship between the speed ratio and power transmission efficiency in the toroidal type continuously variable transmission mechanism, the speed with high power transmission efficiency High degree of freedom in speed ratio when selecting ratio. Therefore, it is easy to perform control for suppressing the temperature increase of the continuously variable transmission mechanism.

  In the control device for the continuously variable transmission mechanism, the transmission elements (51, 52, 53) are provided on the input element (2) side member (51) and the output element (3) side member (52). The moving surface (51b, 52b) and a rolling element (53) for transmitting power by friction rolling the rolling surface (51b, 52b) are provided. The storage means (14) includes a rolling surface ( The relationship between the temperature (T) of 51b, 52b) and the transmission torque (μmax) that can be transmitted via the rolling surfaces (51b, 52b) is stored, and the predetermined temperature (T0) is the rolling surface ( From the relationship between the temperature (T) of 51b, 52b) and the transmission torque (μmax), it may be a temperature (T0) at which the transmission torque (μmax) is not more than a predetermined value (μ0).

According to this configuration, in the toroidal-type continuously variable transmission mechanism, it is possible to effectively suppress an increase in the temperature of the rolling surface to which a high load is applied due to friction rolling of the rolling elements during power transmission. Further, in this case, the predetermined temperature is set to a temperature at which the maximum value of the transmission torque that can be transmitted by the hydraulic oil film formed on the rolling surface is equal to or lower than the predetermined value, thereby increasing the temperature of the rolling surface. Therefore, it is possible to effectively prevent the transmission torque of the continuously variable transmission mechanism from being lowered.
In addition, the code | symbol in said parenthesis shows the code | symbol of the component in embodiment mentioned later as an example of this invention.

  According to the control device for a continuously variable transmission mechanism according to the present invention, the temperature increase of the continuously variable transmission mechanism and the hydraulic oil can be effectively suppressed with simple control.

1 is a skeleton diagram of a transmission having a continuously variable transmission mechanism (toroidal continuously variable transmission mechanism) according to an embodiment of the present invention. FIG. It is a graph which shows the relationship between the speed ratio of a transmission, and the speed ratio of a toroidal type continuously variable transmission mechanism. It is a graph which shows the relationship between the speed ratio (ratio) of a toroidal type continuously variable transmission mechanism, and power transmission efficiency. It is a flowchart which shows the procedure of the control for suppressing the temperature rise of a toroidal type continuously variable transmission mechanism. It is a graph which shows the relationship between the temperature of a toroidal surface, and the maximum value of the torque which can be transmitted. It is a schematic diagram which shows the concept of a high efficiency ratio calculator. It is a figure which shows the target rotational speed map used for selection of the normal ratio of a transmission.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a skeleton diagram of a transmission according to an embodiment of the present invention. The transmission 1 according to this embodiment is a transmission mounted on a vehicle including an engine (internal combustion engine) 10 as a drive source, and the power of the engine 10 is transmitted via a flywheel 11 and a start clutch 12. Input shaft (input element) 2, output shaft (output element) 3 disposed in parallel with input shaft 2, intermediate shaft 4 disposed in parallel with input shaft 2 and output shaft 3, and toroidal-type continuously variable transmission The mechanism 5 includes an idle gear train 6 and a planetary gear mechanism 7 as a differential mechanism.

  A toroidal-type continuously variable transmission mechanism (hereinafter simply referred to as “continuously variable transmission mechanism”) 5 is formed between a pair of input side disks 51 that are concentric with the input shaft 2 and rotate together, and the input side disk 51. The output side disk 52 arranged concentrically and rotatably with respect to the input shaft 2, and disposed between the input side disk 51 and the output side disk 52, and between the input side disk 51 and the output side disk 52. And a power roller (rolling element) 53 for transmitting power.

  The power roller 53 rotates to roll a toroidal surface (rolling surface) 51b formed on the inner surface of the input side disk 51 and a toroidal surface (rolling surface) 52b formed on the inner surface of the output side disk 52. The shaft 53a includes a shaft 53a and is swingable with respect to a swing shaft 53b (trunnion) orthogonal to the rotation shaft 53a and extending in the direction perpendicular to the paper surface. The power roller 53 is swung around the swing shaft 53b. By changing the tilt angle, the toroidal surfaces 51b and 52b roll while changing the contact pressure (frictional force) against the toroidal surfaces 51b and 52b. Thus, the speed ratio (ratio) of the continuously variable transmission mechanism 5 can be changed steplessly.

  Output outer teeth 52 a are provided on the outer periphery of the output side disk 52. A first transmission gear 81 fixed so as to rotate integrally with the intermediate shaft 4 meshes with the external teeth 52a.

  The planetary gear mechanism 7 includes a sun gear 71 concentrically fixed to the intermediate shaft 4, a ring gear 72, and a carrier 74 that supports the sun gear 71 and the pinion 73 meshing with the ring gear 72 so as to rotate and revolve freely. With elements.

  The idle gear train 6 includes a first intermediate gear 61 fixed to the input shaft 2, a second intermediate gear 62 concentric with the intermediate shaft 4 and connected to the carrier 74, and the first intermediate gear 61 and the second intermediate gear 61. The third intermediate gear 63 is engaged with the gear 62 and rotatably supported by the casing of the transmission 1 (not shown).

  A second transmission gear 82 is rotatably supported on the intermediate shaft 4. The transmission 1 is provided with a first clutch 91 and a second clutch 92. The first clutch 91 is configured to be switchable between a connected state in which the second transmission gear 82 and the first transmission gear 81 are connected and an open state in which the connection is broken.

  The second clutch 92 is configured to be switchable between a connected state in which the second transmission gear 82 and the ring gear 72 are connected and an open state in which the connection is broken. The first clutch 91 and the second clutch 92 are constituted by wet multi-plate clutches. The first clutch and the second clutch of the present invention are not limited to the wet multi-plate clutch, and other clutches may be used.

  The second transmission gear 82 meshes with a third transmission gear 83 fixed to the output shaft 3. An output gear 3 a that meshes with the differential gear 13 is fixed to the output shaft 3. The parking gear 3 b is fixed to the output shaft 3 so as to be positioned between the output gear 3 a and the third transmission gear 83.

  Further, the vehicle is provided with an ECU (control means) 14 for controlling the operation of the continuously variable transmission mechanism 5 and the transmission 1. The ECU 14 controls the rotation and swing of the power roller 53 to control the speed ratio (ratio) of the continuously variable transmission mechanism 5 steplessly, and controls the first clutch 91 and the second clutch 92 to change the speed. The speed ratio of the entire machine 1 is controlled. The ECU 14 functions as temperature estimation means, storage means, target speed ratio changing means, etc. according to the present invention.

Further, when the hydraulic fluid that has circulated (circulated) each part of the continuously variable transmission mechanism 5 is discharged from the continuously variable transmission mechanism 5 into the casing (not shown) of the transmission 1, An oil temperature sensor (temperature detection means) 15 for detecting the temperature is provided. Further, the vehicle is provided with an accelerator opening sensor 16 for detecting an accelerator opening AP associated with an accelerator pedal operation by a driver, and a vehicle speed sensor 17 for detecting a vehicle speed V. Detection values (data) of the oil temperature sensor 15, the accelerator opening sensor 16, and the vehicle speed sensor 17 are input to the ECU 14.

  Although illustration is omitted, the continuously variable transmission mechanism 5 of the present embodiment is installed relatively upward in the casing of the transmission 1, and the oil level of the hydraulic oil that accumulates at the bottom of the casing of the transmission 1. Is farther away than Therefore, the hydraulic oil in the casing is not agitated by the operation of the continuously variable transmission mechanism 5. Therefore, the stirring of the hydraulic oil by the continuously variable transmission mechanism 5 is not a dominant factor for the temperature rise or energy loss of the hydraulic oil or the continuously variable transmission mechanism 5.

  FIG. 2 is a graph showing the relationship between the speed ratio (ratio) of the transmission 1 and the speed ratio (ratio) of the continuously variable transmission mechanism 5 according to the present embodiment. The transmission 1 according to the present embodiment can set a low-speed traveling and reverse low mode (low-speed mode) and a high-speed high mode (high-speed mode) as speed ratio modes. The low mode is a state in which the speed ratio of the transmission 1 decreases as the speed ratio of the continuously variable transmission mechanism 5 increases. The high mode is a state in which the speed ratio of the transmission 1 increases as the speed ratio of the continuously variable transmission mechanism 5 increases.

  The low mode and the high mode are switched by the first clutch 91 and the second clutch 92. The low mode is established by bringing the first clutch 91 into an open state and bringing the second clutch 92 into a connected state. The high mode is established by bringing the first clutch 91 into a connected state and bringing the second clutch 92 into a released state.

  In the low mode, the gear ratio between the sun gear 71 of the planetary gear mechanism, the ring gear 72, and the pinion 73 of the carrier 74 is such that the speed of the transmission 1 is increased when the sun gear 71 and the carrier 26 are driven to rotate. When the ratio is set to a predetermined speed ratio, the ring gear 72 and the output shaft 3 connected to the ring gear 72 and the output shaft 3 connected thereto are in a neutral rotation stopped state (geared neutral (GN) state) due to the rotation balance of the sun gear 71 and the carrier 74. Is set to

  In the low mode, in a region where the speed ratio of the transmission 1 is smaller than the predetermined speed ratio at which the geared neutral state is set, the output shaft 3 rotates in the reverse direction and the vehicle moves backward, while the transmission 1 When the speed ratio is smaller than the predetermined speed ratio, the output shaft 3 rotates in the forward rotation direction and the vehicle moves forward (moves forward at low speed). That is, in the low mode, the vehicle reverse state and forward state are switched according to the speed ratio of the transmission 1 with the geared neutral state as a boundary.

  FIG. 3 is a graph showing the relationship between the speed ratio (hereinafter referred to as “ratio”) λ of the continuously variable transmission mechanism 5 and the transmission efficiency (power transmission efficiency). As shown in the graph of the figure, in the continuously variable transmission mechanism 5 of the present embodiment, when the ratio λ changes from a low value to a high value, it passes a predetermined intermediate ratio λm. At the intermediate ratio λm, the power transmission efficiency of the continuously variable transmission mechanism 5 is lowest. That is, in the region where the ratio λ of the continuously variable transmission mechanism 5 is lower than the intermediate ratio λm, the power transmission efficiency gradually decreases (the heat loss energy gradually increases) as the ratio λ of the continuously variable transmission mechanism 5 increases. On the other hand, in a region where the ratio λ is higher than the intermediate ratio λm, the power transmission efficiency gradually increases as the ratio λ of the continuously variable transmission mechanism 5 increases (the heat loss energy gradually decreases). Thus, the ratio λ at which the power transmission efficiency is increased in the continuously variable transmission mechanism 5 has both a shift-up (high-speed) ratio and a shift-down (low-speed) ratio in the direction away from the intermediate ratio λm. .

  The relationship between the ratio of the continuously variable transmission mechanism 5 shown in FIG. 3 and the power transmission efficiency is stored in advance in storage means such as a memory (not shown) built in the ECU 14.

  In the control of the continuously variable transmission mechanism 5 of the present embodiment, the following control is performed as control for suppressing the temperature increase of the continuously variable transmission mechanism 5 and the transmission 1. The control procedure will be described below. FIG. 4 is a flowchart showing the control procedure. In the flowchart of FIG. 6, first, an estimated temperature TS obtained by estimating the temperature of the continuously variable transmission mechanism 5 is calculated (ST1-1). As the estimated temperature TS here, the temperature (drain temperature) of hydraulic oil (lubricating oil) that circulates (circulates) each part of the continuously variable transmission mechanism 5 is measured, and based on the measured operating temperature, for example, The temperature of each part of the continuously variable transmission mechanism 5 such as the toroidal surfaces 51b and 52b can be estimated. The temperature of the hydraulic oil (lubricating oil) circulating through each part of the continuously variable transmission mechanism 5 is discharged from the continuously variable transmission mechanism 5 detected by the oil temperature sensor 15 (see FIG. 1) into the casing of the transmission 1. The discharge temperature (drain temperature) of the hydraulic oil (drain oil) to be used can be used.

  Next, it is determined whether or not the estimated temperature TS is higher than a threshold temperature (predetermined temperature) T0 (ST1-2). The threshold temperature T0 here is a temperature set based on the relationship between the temperature of the toroidal surfaces 51b and 52b of the continuously variable transmission mechanism 5 and the transmission torque. FIG. 5 is a graph showing the relationship between the temperature T of the toroidal surfaces 51b and 52b and the maximum value μmax of the transmission torque. As shown in this graph, the maximum value μmax of the transmission torque of the toroidal surfaces 51b and 52b has a fixed relationship (inversely proportional relationship) with respect to the temperature T of the toroidal surfaces 51b and 52b. The threshold temperature T0 is such that the maximum value μmax of the transmission torque of the toroidal surfaces 51b, 52b (the transmission torque that can be transmitted by the hydraulic oil film formed on the toroidal surfaces 51b, 52b) is not more than a predetermined value μ0 (μmax ≦ μ0).

  Returning to the flow of FIG. 4, if the estimated temperature TS is higher than the threshold temperature T0 as a result of comparing the estimated temperature TS and the threshold temperature T0 (in the case of high temperature) (YES in ST1-2), continuously variable transmission As the ratio of the mechanism 5, a ratio (high efficiency ratio) at which the power transmission efficiency is higher (good) than the current efficiency is selected (ST1-3).

  FIG. 6 is a schematic diagram showing the concept of a high efficiency ratio calculator for calculating the above high efficiency ratio. As shown in the figure, in the calculation of the high efficiency ratio, the temperature (oil temperature) T of the hydraulic oil (lubricating oil) circulating through the continuously variable transmission mechanism 5, the accelerator opening AP, and the vehicle speed V are calculated with a high efficiency ratio calculator. Based on the oil temperature T, the accelerator pedal opening AP, and the vehicle speed V, a high efficiency ratio at which the power transmission efficiency of the continuously variable transmission mechanism 5 becomes higher is calculated as a target ratio. Note that the high efficiency ratio calculator 100 here is conceptual, and the calculation of the high efficiency ratio is actually performed as a function of the ECU 14.

  Specifically, in the graph of FIG. 3, when the current ratio λ of the continuously variable transmission mechanism 5 is a value lower than the intermediate ratio λm (for example, λa), the ratio λ is a lower value (for example, λb ( The continuously variable transmission mechanism 5 is shifted so that <λa)). Thereby, the transmission efficiency of the continuously variable transmission mechanism 5 becomes higher. When the current ratio λ is higher than the intermediate ratio λm (for example, λc), the continuously variable transmission mechanism 5 is shifted so that the ratio λ becomes a higher value (for example, λd (> λc)). Thereby, the power transmission efficiency of the continuously variable transmission mechanism 5 becomes higher.

  Thus, based on the relationship between the ratio of the continuously variable transmission mechanism 5 and the power transmission efficiency, the ratio of the continuously variable transmission mechanism 5 is changed to a ratio having a higher power transmission efficiency than the present, thereby providing the continuously variable transmission mechanism 5. The heat loss energy due to can be reduced, and the temperature increase of the continuously variable transmission mechanism 5 can be suppressed. As a result, the power transmission capacity (transmission torque capacity) of the transmission 1 including the continuously variable transmission mechanism 5 is not decreased transiently, and the driving force of the vehicle is not decreased. The temperature rise can be effectively prevented.

  On the other hand, when the estimated temperature TS is lower than the threshold temperature T0 in the previous ST1-2 (when the temperature is not high) (NO), the speed ratio (ratio) of the transmission 1 is selected as a normal speed ratio (ratio). Normal ratio) is selected (ST1-4). FIG. 7 is a diagram showing an example of a target rotational speed map used for selecting the normal ratio. When selecting the normal ratio, the target (output) speed N of the transmission 1 is set according to the vehicle speed V and the accelerator pedal opening AP according to the map of FIG. The map of the target rotational speed N shown in FIG. 7 includes data on the target rotational speed set for each accelerator opening AP within a predetermined range. Based on the accelerator opening AP and the vehicle speed V in this map, the target rotational speed N is calculated. In the data on the map, the target rotational speed N is set to a larger value as the vehicle speed V is larger and the accelerator pedal opening AP is larger. When the accelerator pedal opening AP indicates an intermediate value of the data on the map shown in FIG. 7, the target rotational speed N is obtained by interpolation calculation.

  In this way, the target rotational speed N is set according to the vehicle speed V and the accelerator pedal opening AP. Then, the transmission 1 and the continuously variable transmission mechanism 5 are controlled so that the rotational speed of the engine 10 becomes equal to the target rotational speed N, so that the ratio of the transmission 1 is set in a stepless manner. Thus, the optimum target ratio of the transmission 1 can be selected from the accelerator opening AP and the vehicle speed V.

  As described above, according to the control device for the continuously variable transmission mechanism of the present embodiment, it is determined that the estimated temperature TS obtained by estimating the temperature of the continuously variable transmission mechanism 5 is higher than the threshold temperature T0. In some cases, the ratio of the continuously variable transmission mechanism 5 is changed to a ratio with higher power transmission efficiency based on a predetermined relationship between the ratio of the continuously variable transmission mechanism 5 and the power transmission efficiency. Thereby, the heat loss energy by the continuously variable transmission mechanism 5 can be reduced by simple control, and the temperature rise of the continuously variable transmission mechanism 5 can be suppressed. Therefore, the power transmission capacity (transmission torque capacity) of the transmission 1 having the continuously variable transmission mechanism 5 is not lowered transiently, and the temperature of the continuously variable transmission mechanism 5 and the transmission 1 is increased without causing a decrease in driving force. It can be effectively prevented.

  In particular, in this embodiment, when it is determined that the temperature of the continuously variable transmission mechanism 5 is high, the ratio of the continuously variable transmission mechanism 5 and the power transmission are not simply changed. Based on the relationship with efficiency, the ratio is changed to a ratio that increases power transmission efficiency. Thereby, compared with the prior art, it is possible to effectively suppress the temperature rise of each part of the continuously variable transmission mechanism 5 and the hydraulic oil during operation, while the control is relatively simple. Can be reduced.

  Further, in the continuously variable transmission mechanism 5 provided in the transmission 1 of the present embodiment, the relationship between the ratio λ and the power transmission efficiency gradually decreases with the region where the power transmission efficiency gradually increases as the ratio λ increases from the intermediate ratio λm. There are two areas, the area. Therefore, when the toroidal-type continuously variable transmission mechanism 5 performs control to change the target ratio to a ratio having a higher power transmission efficiency than the current ratio based on the relationship between the ratio and the power transmission efficiency, the degree of freedom in selecting the ratio is increased. Get higher. Therefore, when the control for suppressing the above-described temperature rise according to the present invention is performed on the transmission 1 including the toroidal-type continuously variable transmission mechanism 5, the control becomes easy.

  In the present embodiment, the threshold temperature T0 of the estimated temperature TS is determined based on the relationship between the temperature of the toroidal surfaces 51b and 52b and the maximum value μmax of the transmission torque that can be transmitted via the toroidal surfaces 51b and 52b. The temperature is such that the maximum value μmax of the torque becomes a predetermined value μ0 or less.

  According to this configuration, in the toroidal-type continuously variable transmission mechanism 5, it is possible to effectively suppress the temperature rise of the toroidal surfaces 51 b and 52 b to which a high load is applied due to the frictional rolling of the power roller 53 during power transmission. In this case, the threshold temperature T0 is set to a temperature at which the maximum torque value μmax that can be transmitted by the oil film of the hydraulic oil formed on the toroidal surfaces 51b and 52b becomes a predetermined value μ0 or less. It is possible to effectively prevent the transmission torque of the continuously variable transmission mechanism 5 from being lowered due to the temperature rise of 51b and 52b.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the technical idea described in the claims and the specification and drawings. Deformation is possible. For example, in the above embodiment, the toroidal continuously variable transmission mechanism 5 is shown as an example of the continuously variable transmission mechanism according to the present invention. However, the continuously variable transmission mechanism according to the present invention is a toroidal continuously variable transmission mechanism. Not limited to this, a belt-type continuously variable transmission mechanism including an endless belt spanned between the driving pulley and the driven pulley may be used.

DESCRIPTION OF SYMBOLS 1 Transmission 2 Input shaft 3 Output shaft 3a Output gear 4 Intermediate shaft 5 Toroidal type continuously variable transmission mechanism 6 Idle gear train 7 Planetary gear mechanism 11 Flywheel 12 Start clutch 13 Differential gear 51 Input side disk 51b Rolling surface (toroidal surface) )
52 Output side disk 52b Rolling surface (toroidal surface)
53 Power roller (rolling element)
53a Rotating shaft 53b Oscillating shaft 91 First clutch 92 Second clutch TS Estimated temperature T0 Predetermined temperature (threshold temperature)
λ ratio (speed ratio)
λm Intermediate ratio (Intermediate speed ratio)

Claims (1)

A rolling surface provided on the input element side of the member and the output element side of the member, the transfer element and a rolling element that transmits power by frictional rolling said transfer dynamic surface, the output element and the input element by friction by transmitting a driving force, the continuously variable transmission mechanism capable of changing the toroidal speed ratio steplessly between,
Temperature estimating means for estimating the temperature of the continuously variable transmission mechanism based on the temperature of the hydraulic oil flowing through the continuously variable transmission mechanism;
Storage means for storing in advance a relationship between the temperature of the rolling surface and the transmission torque that can be transmitted through the rolling surface as a relationship between the speed ratio of the continuously variable transmission mechanism and power transmission efficiency;
When the temperature estimated by the temperature estimation means is determined to be higher than the temperature at which the transmission torque is a predetermined value or less from the relationship between the temperature of the rolling surface and the transmission torque, the continuously variable transmission mechanism Target speed ratio changing means for changing the target speed ratio of the continuously variable transmission mechanism to a speed ratio having higher power transmission efficiency than the present, based on the relationship between the speed ratio and the power transmission efficiency of
A control device for a continuously variable transmission mechanism.

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