JP2020169670A - Continuous variable transmission and abnormality diagnostic method of the same - Google Patents

Abstract

To diagnose abnormality of a belt without a special sensor.SOLUTION: A continuous variable transmission 2 includes a primary pulley 21, a secondary pulley 22, a metal belt 23 stretched between the primary pulley 21 and the secondary pulley 22, and a transmission controller 201. Pressure applied to a pulley oil chamber of the primary pulley 21 or the secondary pulley 22 is detected as pulley oil pressure Ppri, Psec by the transmission controller 201, and abnormality of the metal belt 23 is diagnosed when vibration of a prescribed magnitude is generated in the pulley oil pressure, and a control signal in accordance with the result of the diagnosis is output.SELECTED DRAWING: Figure 5

Description

The present invention relates to a continuously variable transmission and a method for diagnosing an abnormality of a continuously variable transmission, and more particularly to a technique for diagnosing an abnormality of a belt provided in the continuously variable transmission.

Patent Document 1 includes a light emitting element and a light receiving element as a device for diagnosing an abnormality of a belt provided in a continuously variable transmission, and these optical elements allow the light propagation path from the light emitting element to the light receiving element to travel on the belt. Those arranged so as to cross the route are disclosed.

Jikkai Sho 63-027753 (Page 7, Lines 8-17)

According to the apparatus described in Patent Document 1, it is possible to detect an abnormality in which a part of the belt is missing, that is, a broken or broken belt, from the light reception status of the light receiving element. Specifically, when the light receiving element detects the light from the light emitting element, it is assumed that this is due to the damage or defect of the belt, and the abnormality of the belt is diagnosed.

However, according to this, it is necessary to add a special sensor for the purpose of diagnosis, which requires installation space and increases the cost.

In consideration of the above problems, an object of the present invention is to provide a continuously variable transmission and a method for diagnosing an abnormality of a continuously variable transmission, which can diagnose an abnormality of a belt without using a special sensor.

The present invention provides, in one form, a continuously variable transmission mounted on a vehicle. The continuously variable transmission according to the present embodiment includes a primary pulley, a secondary pulley, a belt hung on the primary pulley and the secondary pulley, and a controller, and the controller is a pulley of the primary pulley or the secondary pulley. A hydraulic pressure detection unit that detects the pressure applied to the oil chamber as the pulley hydraulic pressure, and an abnormality diagnosis unit that diagnoses that an abnormality has occurred in the belt with a decrease in tension when a predetermined amount of vibration occurs in the pulley hydraulic pressure. And a signal output unit that outputs a control signal according to the result of the diagnosis by the abnormality diagnosis unit.

The present invention provides a method for diagnosing an abnormality of a continuously variable transmission, which diagnoses an abnormality of a belt in a continuously variable transmission in which power is transmitted between a primary pulley and a secondary pulley via a belt in another embodiment. .. In this embodiment, the pressure applied to the pulley oil chamber of the primary pulley or the secondary pulley is detected as the pulley hydraulic pressure, and when a vibration of a predetermined magnitude occurs in the pulley hydraulic pressure, an abnormality occurs in the belt accompanied by a decrease in its tension. Diagnose the thing.

According to these forms, when the pulley oil chamber is detected and a vibration of a predetermined magnitude occurs in the pulley oil chamber, it is diagnosed that an abnormality has occurred in the belt, which is a special purpose for diagnosis. It is possible to diagnose an abnormality in the belt without using a sensor.

FIG. 1 is a schematic view showing a configuration of a power transmission system of a vehicle including a continuously variable transmission according to an embodiment of the present invention. FIG. 2 is a cross-sectional view showing the configuration of a belt provided in the continuously variable transmission. FIG. 3 is an explanatory diagram showing a belt assembly method (element mounting procedure) of the same as above. FIG. 4 is an explanatory diagram schematically showing the movement of the element when an abnormality occurs in the same belt. FIG. 5 is an explanatory diagram schematically showing a change in pulley hydraulic pressure before and after an abnormality occurs in the same belt. FIG. 6 is a flowchart showing a basic flow of abnormality diagnosis control according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Vehicle drive system configuration)
FIG. 1 schematically shows an overall configuration of a power transmission system (hereinafter referred to as “drive system”) P of a vehicle including a continuously variable transmission 2 according to an embodiment of the present invention.

The drive system P according to the present embodiment includes an internal combustion engine (hereinafter, simply referred to as “engine”) 1 as a vehicle drive source, and is stepless on a power transmission path connecting the engine 1 and the left and right drive wheels 5 and 5. A transmission 2 is provided. The engine 1 and the continuously variable transmission 2 can be connected via a torque converter. The continuously variable transmission 2 converts the rotational power input from the engine 1 at a predetermined gear ratio and outputs the rotational power to the drive wheels 5 via the differential gear 3.

The continuously variable transmission 2 includes a primary pulley 21 on the input side and a secondary pulley 22 on the output side as shifting elements. The continuously variable transmission 2 includes a metal belt 23 hung on the primary pulley 21 and the secondary pulley 22, and the gear ratio is changed by changing the ratio of the contact radius of the metal belt 23 on these pulleys 21 and 22. It can be changed steplessly.

The primary pulley 21 and the secondary pulley 22 are movable sheaves 21b and 22b provided so as to be coaxial with the fixed sheaves 21a and 22a and axially movable along the rotation center axes Cp and Cs of the fixed sheaves. And. The fixed sheave 21a of the primary pulley 21 is connected to the input shaft of the continuously variable transmission 2, and the fixed sheave 22a of the secondary pulley 22 is connected to the output shaft. The gear ratio of the continuously variable transmission 2 is formed between the fixed sheaves 21a and 22a and the movable sheaves 21b and 22b by adjusting the pressure of the hydraulic oil acting on the movable sheaves 21b and 22b of the primary pulley 21 and the secondary pulley 22. It is controlled by changing the width of the V-groove to be formed.

In the present embodiment, an oil pump 6 powered by an engine 1 or an electric motor (not shown) is provided as a source of operating pressure of the continuously variable transmission 2. The oil pump 6 boosts the hydraulic oil stored in the transmission oil pan, and uses this as the original pressure to supply the hydraulic oil of a predetermined pressure through the hydraulic control circuit 7 to the hydraulic chambers of the movable sheaves 21b and 22b (the hydraulic chambers of the movable sheaves 21b and 22b. It is supplied to 21c and 22c (corresponding to the "pulley oil chamber"). In FIG. 1, the hydraulic pressure supply path from the hydraulic pressure control circuit 7 to the pulley oil chambers 21c and 22c is shown by a dotted line with an arrow.

The rotational power output from the continuously variable transmission 2 is transmitted to the drive shaft 4 via the final gear train or auxiliary transmission (neither shown) and the differential gear 3 set to a predetermined reduction ratio to drive the vehicle. Rotate the ring 5.

(Control system configuration and basic operation)
The operations of the engine 1 and the continuously variable transmission 2 are controlled by the engine controller 101 and the transmission controller 201, respectively. Both the engine controller 101 and the transmission controller 201 are configured as electronic control units, and include a central processing unit (CPU), various storage devices such as RAM and ROM, and a microcomputer provided with an input / output interface and the like.

The engine controller 101 inputs a detection signal of an operating state sensor that detects the operating state of the engine 1, executes a predetermined calculation based on the operating state, and executes a predetermined calculation based on the operating state, such as the fuel injection amount, the fuel injection timing, and the ignition timing of the engine 1. To set. As the operation state sensor, the accelerator sensor 111 detects the amount of operation of the accelerator pedal by the driver (hereinafter referred to as "accelerator opening"), the rotation speed sensor 112 detects the rotation speed of the engine 1, and detects the temperature of the engine cooling water. In addition to the cooling water temperature sensor 113 and the like, an air flow meter, a throttle sensor, a fuel pressure sensor, an air fuel ratio sensor and the like (not shown) are provided. The engine controller 101 inputs the detection signals of these sensors.

The transmission controller 201 is connected to the engine controller 101 so as to be able to communicate with each other via a CAN standard bus. Further, in relation to the control of the continuously variable transmission 2, the vehicle speed sensor 211 for detecting the traveling speed of the vehicle, the input side rotation speed sensor 212 for detecting the rotation speed of the input shaft of the continuously variable transmission 2, and the continuously variable transmission. An output-side rotation speed sensor 213 that detects the rotation speed of the output shaft 2, an oil temperature sensor 214 that detects the temperature of the hydraulic oil of the continuously variable transmission 2, a shift position sensor 215 that detects the position of the shift lever, and the like are provided. ing. In the present embodiment, in addition to the above, the pressure applied to the pulley oil chamber 21c of the primary pulley 21 (hereinafter referred to as “primary pulley oil pressure”) Ppri is detected, and the pressure applied to the pulley oil chamber 22c of the secondary pulley 22. A secondary oil pressure sensor 217 that detects Psec (hereinafter referred to as “secondary pulley oil pressure”) is provided. The transmission controller 201 inputs information on the operating state of the engine 1 such as the accelerator opening degree from the engine controller 101, and also inputs the detection signals of these sensors.

The transmission controller 201 determines the shift range selected by the driver based on the signal from the shift position sensor 215 as basic control regarding the shift, and the continuously variable transmission 2 is based on the accelerator opening, the vehicle speed, and the like. Set the target gear ratio of. Then, the transmission controller 201 uses the hydraulic pressure generated by the oil pump 6 as the main pressure to generate predetermined pulley hydraulic pressures Ppri and Psec according to the target gear ratio with respect to the movable sheaves 21b and 22b of the primary pulley 21 and the secondary pulley 22. A control signal is output to the hydraulic control circuit 7 so as to operate.

(Composition of metal belt)
FIG. 2 shows the configuration of the metal belt 23 by a cross section perpendicular to the circumferential direction of the metal belt 23.

In the present embodiment, the continuously variable transmission 2 includes a pair of variable pulleys, specifically, a primary pulley 21 and a secondary pulley 22, and a metal belt 23 spanned on the pair of pulleys 21 and 22. .. The continuously variable transmission 2 is a push belt type, and the metal belt 23 arranges a plurality of elements 231 which are power transmission media in the plate thickness direction thereof, and may be referred to as a ring 232 (sometimes referred to as a "hoop" or "band"). ) To unite each other.

The ring 232 is one ring (sometimes referred to as a "ring set") formed by laminating a plurality of ring members 232a to 232d thinner than the ring 232, and the ring 232 is formed on the one ring or the ring set 232. A plurality of elements 231 are attached to form a metal belt 23. Since there is only one ring 232, the metal belt 23 according to this embodiment may be referred to as a monoring type metal belt or simply a "monobelt". FIG. 2 shows a case where the number of ring members is four (232a to 232d), but it goes without saying that the number of ring members is not limited to this.

The element 231 is generally composed of a base portion 231a and a pair of side portions 231b and 231b extending in the same direction as the base portion 231a extending in the extending direction, and in the present embodiment, the element 231 has a substantially U-shape as a whole. I'm doing it. The base portion 231a, also called a saddle portion, has a length sufficient to cross the ring 232, and contact surfaces of the primary pulley 21 and the secondary pulley 22 with respect to the sheaves 21a, 21b, 22a, and 22b are formed at both ends thereof. ing. The stretching direction of the base portion 231a is the width direction of the element 231 and coincides with the lateral direction L of the metal belt 23. The side portion 231b, also called a pillar portion, is connected to the base portion 231a on each side sandwiching the ring 232, and its extending direction is the height direction of the element 231 and coincides with the radial direction R of the metal belt 23. The inner surfaces of the pair of side portions 231b and 231b facing each other and the upper surface of the base portion 231a form a receiving portion 231r of the element 231 that opens in the direction perpendicular to the lateral direction L, that is, in the radial direction R of the metal belt 23. .. In the present embodiment, the opening direction of the receiving portion 231r is outward with respect to the radial direction R of the metal belt 23. The element 231 is attached to the ring 232 from the inner peripheral side of the metal belt 23 in a state where the ring 232 is received by the receiving portion 231r.

The element 231 has hooks or holding pieces f protruding inward from the inner surface of the left and right side portions 231b forming the receiving portion 231r, and the base portion 231a and these hooks are attached to the ring 232. A ring 232 is held between the ring and f. The element 231 has a pair of notches n on both the left and right side portions 231b and 231b that partially expand the space of the receiving portion 231r in the lateral direction L. The notch n gives the hook f flexibility, imparts a force for pressing the ring 232, and forms a space for the ring 232 to escape when the element 231 is attached.

3A to 3C show a method of assembling the metal belt 23, specifically, a procedure of attaching the element 231 to the ring 232 in chronological order. FIG. 3 shows the procedure by changing the posture of the ring 232 for convenience of illustration, but it goes without saying that the orientation of the element 231 can be changed in the actual mounting.

First, the element 231 is tilted with respect to the ring 232 and arranged on the inner peripheral side of the ring 232, and one side edge of the ring 232 is inserted into the receiving portion 231r of the element 231. Then, the element 231 is moved so that the base portion 231a is brought closer to the ring 232, and as shown in FIG. 3A, a hook provided on the base portion 231a and one side portion 231b (in the state shown in the figure, the left side). The side edge of the ring 232 is brought to the notch n through the hook) f provided in the portion 231b.

Then, as shown in FIG. 3B, the element 231 is rotated about the portion of the ring 232 located between the base 231a and the hook f (in the state shown in the figure, the opposite of clockwise rotation). Rotate) to eliminate the tilt of the element 231 with respect to the ring 232. In this state, the base 231a of the element 231 is parallel to the ring 232.

After the base 231a of the element 231 is in a state parallel to the ring 232, the element 231 is relative to the ring 232 in the direction in which the side edge of the ring 232 comes out from the notch n, as shown in FIG. 3 (c). (In the state shown in the figure, the element 231 is moved to the left side), and the ring 232 is placed in the center of the base portion 231a. As a result, the mounting of one element 231 is completed.

By repeating such a procedure for all the elements 231 over the entire circumference of the metal belt 23, the metal belt 23 is completed. The tension of the ring 232 further binds the front and rear elements 231 to each other by engaging the convex portion p (FIG. 2) provided on the front surface of the element 231 with the concave portion provided on the back surface of the adjacent element 231. ..

(Principle of abnormal diagnosis of metal belt)
In the metal belt 23 in which a plurality of ring members 232a to 232d are laminated to form the ring 232, among the ring members 232a to 232d, the ring member on the innermost peripheral side in the radial direction of the metal belt 23 (hereinafter, "innermost circumference"). The friction between the (referred to as "ring member") 232d and the base portion 231a of the element 231 in contact with the inner peripheral surface thereof causes the innermost ring member 232d to wear and break. The breakage of the innermost ring member 232d may be caused not only by friction but also by fatigue due to repeated operation of the continuously variable transmission 2. Then, when the innermost ring member 232d is broken, if the vehicle is left unattended and the vehicle continues to run, the influence of the break will spread to the other ring members 232a to 232c, and eventually the entire ring 232 will be broken. Develops into a break. Therefore, when a break occurs in the innermost ring member 232d, it is necessary to promptly detect this and shift to control for protecting the ring 232. In the present embodiment, the breakage of the innermost ring member 232d is defined as an abnormality of the metal belt 23, and when the breakage of the innermost ring member 232d is detected, it is assumed that the metal belt 23 has an abnormality. Performs ring protection control.

FIG. 4 schematically shows the movement of the element 231 when an abnormality occurs in the metal belt 23, and the abnormality diagnosis principle of the metal belt 23 will be described with reference to the figure.

When a break B occurs in the innermost ring member 232d of the metal belt 23, the tension of the ring 232 decreases at the place where the break B occurs. As a result, the ring 232 of the pulley (FIG. 4 illustrates the secondary pulley 22) is stretched at the belt winding portion in contact with the metal belt 23, and the element 231 has an outer circumference as shown in FIG. 4 (b). It moves to the side, in other words, outward with respect to the radial direction of the metal belt 23. Then, in conjunction with the movement of the element 231 the movable sheave 22b of the secondary pulley 22 moves in the direction of approaching the fixed sheave 22a (that is, in the direction of narrowing the groove width of the secondary pulley 22), and the pulley hydraulic pressure of the secondary pulley 22 Psec decreases. After that, the portion where the break B does not occur reaches the belt winding portion, and when passing through the belt winding portion, the tension of the ring 232 returns to the original size, as shown in FIG. , The element 231 moves to the inner peripheral side, and the distance between the fixed sheave 22a and the movable sheave 22b (that is, the groove width) is widened, so that the pulley hydraulic pressure Psec increases. When the innermost ring member 232d is broken in this way, the element 231 moves due to the decrease in the tension of the ring 232, specifically, the element 231 reciprocates to the outer peripheral side and the inner peripheral side. Vibration occurs in the pulley hydraulic pressure Psec. In the present embodiment, when a vibration of a predetermined magnitude is detected in the pulley hydraulic pressure Psec from the detected waveform based on the pulley hydraulic pressure Psec, it is assumed that the innermost ring member 232d is broken, and the metal belt 23 Diagnose abnormalities.

FIG. 5 shows changes in the pulley hydraulic pressures Ppri and Psec of the primary pulley 21 and the secondary pulley 22 when the torque TRQpri input to the primary pulley 21 is increased while the gear ratio of the continuously variable transmission 2 is constant. It is schematically shown that changes in pulley hydraulic pressure Ppri and Psec before and after an abnormality occurs in the metal belt 23. FIG. 5 shows a case where vibration occurs in the secondary pulley hydraulic pressure Psec, but when an abnormality occurs, the pulley hydraulic pressure vibrates not only in the secondary pulley 22 but also in the primary pulley 21. In the present embodiment, the gear ratio of the continuously variable transmission 2 is controlled by the primary pulley hydraulic pressure Ppri, and the belt clamping force is formed by the secondary pulley hydraulic pressure Psec.

As the torque input to the primary pulley 21 (hereinafter referred to as "transmission input torque") TRQpri increases, the torque output from the secondary pulley 22 (hereinafter referred to as "transmission output torque") TRQsec also increases. As long as the innermost ring member 232d is not broken and the metal belt 23 is normal, the gear ratio is constant. Therefore, the secondary pulley hydraulic pressure Psec is constant in order to generate a constant belt clamping force. is there. However, when the innermost ring member 232d breaks at time T1, vibration occurs in the secondary pulley hydraulic pressure Psec according to the principle described above.

Here, the transmission output torque TRQsec does not decrease before and after the time T1 when the secondary pulley hydraulic pressure Psec vibrates, and the transmission output torque TRQsec continues to increase with respect to the increase in the transmission input torque TRQpri. It shows that the power transmission itself via the metal belt 23 continues between the primary pulley 21 and the secondary pulley 22 regardless of the breakage of the innermost ring member 232d. This indicates that after the innermost ring member 232d is broken, there is a certain amount of time before the vehicle becomes inoperable due to the breakage of the entire ring 232. Therefore, in the present embodiment, when the innermost ring member 232d is broken and an abnormality of the metal belt 23 is detected, an excessive load is applied to the ring members 232a to 232c other than the innermost ring member 232. Control to suppress and protect the metal belt 23 (hereinafter referred to as "belt protection control") is executed.

(Explanation by flowchart)
FIG. 6 shows a basic flow of abnormality diagnosis control (including belt protection control) according to the present embodiment by a flowchart.

In the present embodiment, the abnormality diagnosis control is executed by the transmission controller 201, and the transmission controller 201 is programmed to execute the control routine shown in FIG. 6 at a predetermined cycle while the vehicle is running. The abnormality diagnosis control is executed not only by the transmission controller 201 but also by the engine controller 101 or other controllers other than these.

In S101, the output of the secondary oil pressure sensor 217 is read.

In S102, the magnitude of vibration of the secondary pulley hydraulic pressure Psec (hereinafter referred to as “vibration level”, and amplitude can be adopted as an index thereof) LEV is calculated based on the output of the secondary hydraulic pressure sensor 217.

In S103, it is determined whether or not the vibration level LEV of the secondary pulley hydraulic pressure Psec is equal to or higher than the predetermined value LEVthr. The predetermined value LEV is a vibration level detected when the innermost ring member 232d is broken, and can be predetermined through experiments or the like. If the vibration level LEV is equal to or higher than the predetermined value LEVthr, the process proceeds to S104, and if the vibration level is less than the predetermined value LEVthr, the process proceeds to S105.

In S104, belt protection control is executed. In the present embodiment, as belt protection control, a control signal for reducing the torque of the engine 1 is output to the engine controller 101 to reduce the load applied to the metal belt 23.

In S105, the belt protection control is not executed, but the normal control is executed.

In the present embodiment, the "controller" of the continuously variable transmission 2 is configured by the transmission controller 201, and the abnormality diagnosis method of the continuously variable transmission 2 according to the present embodiment is implemented. Then, the function of the "hydraulic pressure detection unit" is realized by the processing of S101 in the flowchart shown in FIG. 6, the function of the "abnormality diagnosis unit" is realized by the processing of S103, and the function of the "signal output unit" is realized by the processing of S104. To.

(Explanation of action and effect)
The continuously variable transmission 2 according to the present embodiment and the drive system P including the continuously variable transmission 2 are configured as described above, and the effects obtained by the present embodiment will be described below.

First, while the vehicle is running, the pressure applied to the pulley oil chamber 22c of the variable pulley (secondary pulley 22 in this embodiment) of the continuously variable transmission 2 is detected, and the pulley hydraulic pressure Psec has a predetermined magnitude. By diagnosing that the metal belt 23 has an abnormality when vibration occurs, it is possible to diagnose the abnormality of the metal belt 23 without using a special sensor for the purpose of diagnosis (claim). Effects corresponding to 1 and 6).

Secondly, as an abnormality of the metal belt 23, among a plurality of ring members 232a to 232d constituting the ring 232, an abnormality due to a breakage of the innermost ring member 232d provided on the innermost peripheral side is targeted for diagnosis. Since the decrease in tension of the ring 232 due to fracture appears as its vibration in the pulley hydraulic pressure Psec, it is possible to accurately diagnose the abnormality of the metal belt 23 through the monitoring of the pulley hydraulic pressure Psec (effect corresponding to claim 2). ..

Thirdly, by adopting a continuously variable transmission 2 provided with a metal belt 23 known as a monobelt as a subject of diagnosis, a specific continuously variable transmission applicable to the implementation of the present invention is provided (). Effect corresponding to claim 3).

Fourth, when an abnormality in the metal belt 23 is diagnosed, a control signal for reducing the torque of the engine 1 is output as belt protection control to reduce the load applied to the metal belt 23, and breakage still occurs. It is possible to protect the ring members 232a to 232c which are in a normal state and to extend the distance during which the retractable travel is possible after an abnormality occurs (effect corresponding to claim 4).

In the above description, the pulley oil pressure Psec of the secondary pulley 22 is detected by the secondary oil pressure sensor 217 for the purpose of diagnosing the abnormality. However, the pulley hydraulic pressure to be monitored at the time of diagnosis is not limited to this, and may be the pulley hydraulic pressure Ppri of the primary pulley 21. The primary hydraulic pressure sensor 216 detects the primary pulley hydraulic pressure Ppri, and when a vibration of a predetermined magnitude occurs in the primary hydraulic pressure sensor 216, it is diagnosed that an abnormality has occurred in the metal belt 23.

Further, the belt protection control executed by the transmission controller 201 is not limited to outputting a control signal for reducing the torque of the engine 1, and the belt winding in the pulley in which vibration of a predetermined magnitude occurs in the pulley hydraulic pressure Ppri and Psec. It may be to output a control signal for increasing the diameter. This also makes it possible to similarly reduce the load on the metal belt 23, protect the ring member in a normal state, and extend the cruising range thereafter (effect corresponding to claim 5).

When the abnormality of the metal belt 23 is diagnosed, it may be added to the belt protection control described above, or instead, the driver may be notified of the occurrence of the abnormality and a warning may be given. As such control, activating a warning light can be exemplified.

In the above description, the drive source of the vehicle is configured by the engine 1, but the drive source of the vehicle is not only the internal combustion engine but also an electric motor (for example, a motor generator) or a combination of the internal combustion engine and the electric motor. It is configurable.

Although the embodiments of the present invention have been described above, the present invention is not limited to this, and it is said that various changes and modifications can be made within the scope of the matters described in the claims. Not to mention.

P ... Drive system 1 ... Internal engine 2 ... Continuously variable transmission 21 ... Primary pulley 21a ... Fixed pulley 21b ... Movable pulley 22 ... Secondary pulley 22a ... Fixed pulley 22b ... Movable pulley 23 ... Metal belt 231 ... Element 232 ... Ring 231a ... Base 231b ... Side 231r ... Receptor 3 ... Differential gear 4 ... Drive shaft 5 ... Drive wheel 6 ... Oil pump 7 ... Hydraulic control circuit 101 ... Engine controller 201 ... Transmission controller (controller, hydraulic pressure detector, abnormality diagnosis unit, Signal output section)

Claims (6)

It is a continuously variable transmission mounted on a vehicle.
With the primary pulley
With the secondary pulley
The primary pulley and the belt hung on the secondary pulley,
With the controller
Consists of including
The controller
A hydraulic pressure detection unit that detects the pressure applied to the primary pulley or the pulley oil chamber of the secondary pulley as the pulley hydraulic pressure,
An abnormality diagnosis unit that diagnoses that an abnormality accompanied by a decrease in tension of the belt has occurred when a vibration of a predetermined magnitude occurs in the pulley hydraulic pressure.
A signal output unit that outputs a control signal according to the result of diagnosis by the abnormality diagnosis unit, and
A continuously variable transmission equipped with. The belt is
With the ring
With a plurality of elements bound by the ring,
With
The ring is a laminated ring formed by laminating a plurality of ring members.
The abnormality diagnosis unit diagnoses an abnormality caused by a breakage of the ring member provided on the innermost peripheral side in the radial direction of the belt among the plurality of ring members as an abnormality of the belt.
The continuously variable transmission according to claim 1. The belt is
With the ring
With a plurality of elements bound by the ring,
With
Each of the elements has a receiving portion that opens in the radial direction of the belt, and the receiving portion receives the ring.
The continuously variable transmission according to claim 1 or 2. The continuously variable transmission according to any one of claims 1 to 3, which is mounted on a vehicle having an engine as a drive source.
The signal output unit outputs the control signal for reducing the torque of the engine when the abnormality of the belt is diagnosed by the abnormality diagnosis unit.
Continuously variable transmission. The signal output unit is the belt of the primary pulley or the secondary pulley in which the pulley hydraulic pressure vibrates to the predetermined magnitude when an abnormality of the belt is diagnosed by the abnormality diagnosis unit. Outputs the control signal that increases the winding diameter of the
The continuously variable transmission according to any one of claims 1 to 3. A continuously variable transmission abnormality diagnosis method for diagnosing an abnormality of the belt in a continuously variable transmission in which power is transmitted between the primary pulley and the secondary pulley via a belt.
The pressure applied to the primary pulley or the pulley oil chamber of the secondary pulley is detected as the pulley hydraulic pressure,
When a vibration of a predetermined magnitude occurs in the pulley hydraulic pressure, it is diagnosed that an abnormality accompanied by a decrease in the tension of the belt has occurred.
Abnormality diagnosis method for continuously variable transmission.

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