JP2016148379A - Control device of continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device of a continuously variable transmission capable of reducing noise caused by contact of an element and a pulley without using an elastic body for damping vibration.SOLUTION: A control device 34 of a continuously variable transmission 1 includes a contact frequency calculation portion for calculating a contact frequency on the basis of a rotating speed of an endless member 13, a natural frequency request portion for obtaining a natural frequency of a fixed driven half body 26 and an output shaft 14, a resonance region determination portion (STEP 2) for determining whether the contact frequency is a pulley resonance region to resonate in agree with the natural frequency or not, and a winding radius control portion (STEP 5) for controlling a winding radius of the endless member 13 so that the endless member 13 is kept into contact with a radial position of a driven pulley 12 in which an amplitude of the natural frequency becomes maximum, when the resonance region determination portion determines the resonance region.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a control device for a belt-type continuously variable transmission.

  2. Description of the Related Art Conventionally, a belt-type continuously variable transmission including a control device that controls a gear ratio is known (see, for example, Patent Document 1).

  In the continuously variable transmission of Patent Document 1, a contact portion is provided between the back surface of the fixed pulley and the parking gear disposed on the back surface side of the fixed pulley, and an elastic body is provided in the contact portion. The vibration caused by the collision between the element and the fixed pulley is suppressed, and the noise is reduced.

JP 2010-242863 A

  In the continuously variable transmission of Patent Document 1, since the damping structure includes an elastic body, the elastic body is worn by contact with the pulley as the travel distance increases, and the damping effect of the elastic body is reduced. There is a problem that the damping force of the elastic body is reduced by the chemical reaction between the oil and the oil.

  In view of the above, an object of the present invention is to provide a control device for a continuously variable transmission that can reduce noise caused by contact between an element and a pulley without using an elastic body for vibration damping.

In order to achieve the above object, the present invention provides:
A pulley shaft to which a driving force from a driving source is transmitted;
An output shaft disposed parallel to the pulley shaft;
A drive pulley composed of a movable drive half movable in the axial direction with respect to the pulley shaft and a fixed drive half fixed to the pulley shaft;
A driven pulley composed of a movable driven half movable in the axial direction with respect to the output shaft and a fixed driven half fixed to the output shaft;
A plurality of elements in contact with the drive pulley and the driven pulley, and an endless member having a ring for holding the plurality of elements;
A continuously variable transmission in which the endless member is wound between the drive pulley and the driven pulley;
A control device used for
The frequency of the fixed drive half or the fixed driven half generated when the fixed drive half or the fixed driven half and the element come into contact is defined as a contact frequency,
A contact frequency calculation unit that calculates the contact frequency based on the rotation speed of the endless member;
A natural frequency requesting unit for obtaining a natural frequency of the fixed drive half and the pulley shaft, or the fixed driven half and the output shaft;
A resonance region determination unit that determines whether the contact frequency is a pulley resonance region that resonates in accordance with the natural frequency;
When the resonance region determination unit determines that the resonance region is in the resonance region, the endless member is wound so that the endless member contacts the radial position of the drive pulley or the driven pulley where the amplitude of the natural frequency is maximum. And a winding radius control unit for controlling the attaching radius.

  According to the present invention, when the contact frequency is a pulley resonance region that resonates in accordance with the natural frequency of the fixed drive half and the pulley shaft or the fixed driven half and the output shaft, the natural frequency The winding radius of the endless member is controlled so that the element of the endless member contacts the radial position of the fixed drive half or the fixed driven half with the maximum amplitude. Thereby, according to this invention, the vibration of a continuously variable transmission can be suppressed and a noise can be reduced.

  Further, the present invention does not suppress noise caused by resonance at the abutting portion by abutting the abutting portion constituted by an elastic body between the endless member and the pulley as in the conventional product. Therefore, according to the control device of the present invention, it is possible to prevent the noise suppression function from being lowered due to secular change as in the conventional product. Furthermore, since the contact portion is not provided, it is possible to improve the response by reducing the inertia of the continuously variable transmission, and to increase the size and weight of the continuously variable transmission. Therefore, it contributes to improved fuel efficiency and vehicle mountability.

  In the present invention, the continuously variable transmission is mounted on a vehicle, the drive source is an internal combustion engine, and the continuously variable transmission is positioned in a power transmission path between the internal combustion engine and the pulley shaft. Thus, an engagement mechanism capable of switching between a transmission state for transmitting the driving force and a release state for interrupting the transmission is provided, and the vehicle has an internal combustion engine when the vehicle traveling speed is less than a predetermined value. An internal combustion engine stop mechanism for stopping is provided, and the control device detects whether the vehicle is in a state of traveling while stopping the internal combustion engine by the operation of the internal combustion engine stop mechanism for traveling. A detection unit, and an engagement mechanism release unit that releases the engagement mechanism when the vehicle is running while the internal combustion engine is stopped. When the winding radius control unit controls the winding radius, Release the engagement mechanism at the joint release part It can be configured to.

  According to such a configuration, when the internal combustion engine that is traveling is stopped (so-called idling stop state during traveling), the control device can detect the fixed driven half and the output shaft, or the fixed drive half and the pulley shaft in the resonance region. Control is performed to bring the endless member into contact with the position where the amplitude of the natural frequency becomes maximum. When the internal combustion engine is stopped, power transmission between the internal combustion engine and the drive pulley is cut off by the engagement mechanism.

  Therefore, the speed ratio of the continuously variable transmission can be controlled without taking into consideration the influence such as a sense of incongruity to the driver that occurs when the rotational speed of the internal combustion engine changes greatly, and the endless member in the control device of the present invention. It is possible to increase the degree of freedom in controlling the wrapping radius.

Explanatory drawing which shows embodiment of the control apparatus of the continuously variable transmission of this invention. The perspective view which shows a part of endless member of this embodiment. FIG. 3A is a schematic view showing the thickness of an element constituting the endless member. FIG. 3B is an explanatory view schematically showing the frequency of vibration when the element of the endless member contacts the driven pulley. FIG. 3C is an explanatory view schematically showing the number of vibrations at the time of contact that occur while the endless member makes one rotation. FIG. 3D schematically illustrates a state where resonance occurs and the noise increases when the natural frequency of the fixed driven half and the output shaft overlap with the frequency generated when the element of the endless member contacts the fixed driven half. Explanatory drawing shown. Explanatory drawing which shows the state which the element of the continuously variable transmission of this embodiment contacts and a vibration arises. The flowchart which shows the process of the control apparatus of this embodiment. Explanatory drawing which shows the part which the state and amplitude which the fixed driven half of this embodiment vibrates become the maximum. FIG. 7A is a graph showing the rotational speed of the internal combustion engine with respect to a decrease in the vehicle speed of the present embodiment. FIG. 7B is a graph showing a change in the gear ratio with respect to a change in the rotation speed of the endless member.

  An embodiment of a control device for a continuously variable transmission according to the present invention will be described in detail with reference to the drawings. A continuously variable transmission according to the present embodiment is a belt-type continuously variable transmission and is mounted horizontally in an FF type automobile. The continuously variable transmission to which the control device of the present invention is applied is not limited to the one mounted on the FF type automobile, and the effects of the present invention can be obtained even when used for other vehicles. For example, the control device of the present invention can also be applied to an FR type vehicle, a midship type vehicle, and a motorcycle.

  As shown in FIG. 1, an automobile equipped with a continuously variable transmission 1 according to this embodiment includes an internal combustion engine 2 (engine) as a driving source for traveling, a torque converter 3, a differential gear 4, and left and right motors. And a drive wheel 5.

  The internal combustion engine 2 includes a throttle valve (not shown) disposed in the intake passage. The throttle valve (not shown) is not mechanically connected to the accelerator pedal 6 but is connected to the accelerator pedal 6 by an electric signal via a drive-by-wire mechanism (not shown) including an actuator such as an electric motor. It is opened and closed according to the operation.

  The air sucked into the internal combustion engine 2 is mixed with fuel injected from an injector (not shown) through an intake manifold after the amount of inflow is adjusted by a throttle valve (not shown) to become an air-fuel mixture. When the intake valve of the cylinder is opened, the air-fuel mixture flows into the cylinder. The air-fuel mixture in the cylinder is ignited by the spark plug and burns, pressing the piston. The pressed piston rotates the crankshaft 2a, and the burned air-fuel mixture becomes exhaust gas and is discharged from the internal combustion engine 2.

  The driving force output from the crankshaft 2 a of the internal combustion engine 2 is transmitted to the differential gear 4 via the continuously variable transmission 1 and distributed to the left and right drive wheels 5.

  The torque converter 3 includes a pump impeller 3a coupled to the crankshaft 2a of the internal combustion engine 2, a turbine runner 3b, and a stator 3c, and transmits power via a fluid (oil). The torque converter 3 includes a lock-up clutch 3d. By engaging the lock-up clutch 3d, the driving force of the crankshaft 2a can be directly transmitted to the turbine runner 3b without using fluid (oil).

  The continuously variable transmission 1 includes an input shaft 9, a forward / reverse switching mechanism 10 including a planetary gear mechanism, a drive pulley 11, a driven pulley 12, and an endless member including a metal belt wound around the drive pulley 11 and the driven pulley 12. 13 and an output shaft 14 arranged in parallel to the input shaft 9.

  The input shaft 9 is connected to the turbine runner 3b, and the driving force of the internal combustion engine 2 output from the crankshaft 2a is transmitted via the torque converter 3. The drive pulley 11 is supported on the input shaft 9 so as to be relatively rotatable. The forward / reverse switching mechanism 10 is disposed so as to sandwich the drive pulley 11 between the torque converter 3 and the forward / reverse switching mechanism 10.

  The forward / reverse switching mechanism 10 is a double pinion type planetary gear mechanism, and includes a sun gear 15, a ring gear 16, a carrier 17, a first pinion 18, a second pinion 19, a forward clutch 20, and a reverse gear. And a brake 21.

  The sun gear 15 is fixed to a protruding portion of the input shaft 9 that protrudes from the torque converter 3 side through the drive pulley 11 to the opposite side. The ring gear 16 is provided with a reverse brake 21, and the ring gear 16 can be fixed to the transmission case 22 by fastening the reverse brake 21. The first pinion 18 and the second pinion 19 mesh with each other, the first pinion 18 meshes with the sun gear 15, and the second pinion 19 meshes with the ring gear 16.

  The carrier 17 pivotally supports the first pinion 18 and the second pinion 19 so as to rotate and revolve. In other words, the first pinion 18 and the second pinion 19 are rotatably supported by the carrier 17, and the carrier 17 rotates relative to the sun gear 15 and the ring gear 16 together with the first pinion 18 and the second pinion 19. It is provided freely.

  The forward clutch 20 is connected to the input shaft 9 and the carrier 17, and the sun gear 15 and the carrier 17 are integrally rotated by fastening the forward clutch 20. The carrier 17 is connected to the drive pulley 11.

  The forward clutch 20 and the reverse brake 21 are both hydraulic friction engagement mechanisms that are frictionally engaged by hydraulic pressure. When the forward clutch 20 is engaged and the reverse brake 21 is released, the rotation of the input shaft 9 is directly transmitted to the drive pulley 11 via the carrier 17, and the drive pulley 11 rotates in the direction in which the automobile moves forward. .

  When the reverse brake 21 is engaged and the forward clutch 20 is released, the ring gear 16 is fixed to the transmission case 22 and the carrier 17 rotates in the direction opposite to the sun gear 15. As a result, the drive pulley 11 rotates in the direction in which the automobile moves backward. Further, when both the forward clutch 20 and the reverse brake 21 are released, the forward / reverse switching mechanism 10 can cut off power transmission between the drive pulley 11 and the input shaft 9.

  In the continuously variable transmission 1, power is transmitted through a frictional force between the drive pulley 11, the driven pulley 12, and the endless member 13. The drive pulley 11 rotates integrally with the pulley shaft 23 and is movable in the axial direction of the pulley shaft 23, the pulley shaft 23 connected to the carrier 17, the fixed drive half 24 fixed to the pulley shaft 23, and the pulley shaft 23. And a movable drive half 25.

  The movable drive half 25 can be brought close to the fixed drive half 24 by supplying hydraulic pressure to the hydraulic chamber 25a, and can be separated from the fixed drive half 24 by discharging oil from the hydraulic chamber 25a. it can. Thereby, the width | variety of the V-shaped pulley groove | channel 11a of the drive pulley 11 formed in the opposing surface of the fixed drive half body 24 and the movable drive half body 25 can be adjusted.

  The driven pulley 12 includes a fixed driven half 26 fixed to the output shaft 14 and a movable driven half 27 that rotates integrally with the output shaft 14 and is movable in the axial direction of the output shaft 14. The movable driven half 27 can be brought close to the fixed driven half 26 by supplying hydraulic pressure to the hydraulic chamber 27a, and can be separated from the fixed driven half 26 by discharging oil from the hydraulic chamber 27a. it can. Thereby, the width | variety of the V-shaped pulley groove 12a of the driven pulley 12 formed in the opposing surface of the fixed driven half body 26 and the movable driven half body 27 can be adjusted.

  As shown in FIG. 2, the endless member 13 made of a metal belt includes a plate-like element 28 having a pair of recesses 28 a and a plurality of metal rings 29. The metal ring 29 is formed by welding ends of thin maraging steel plates to each other, forming a container, cutting it to a predetermined width, rolling it to a predetermined circumferential length, and performing the containerization process again. It is a thing.

  Each metal ring 29 is laminated with a slightly different circumference. The metal ring 29 has an arc shape whose central portion is convex outward in a sectional view. Thereby, when laminating the metal ring 29, the metal rings 29 can be engaged with each other by the arc shape, and the laminated state can be easily maintained. A plurality of the plate-like elements 28 are laminated in the plate thickness direction to form an annular body, and the laminate of the metal rings 29 is inserted into the pair of recesses 28a to complete the endless member 13 as a metal belt. It is not always necessary to stack a plurality of metal rings 29. If sufficient strength is obtained, one metal ring 29 may be used without stacking the metal rings 29.

  In the continuously variable transmission 1, the width of the pulley grooves 11 a and 12 a of the drive pulley 11 and the driven pulley 12 is changed by thrust generated by hydraulic pressure, and the winding radius of the endless member 13 is changed. 9 (or the rotational speed of the pulley shaft 23) / (the rotational speed of the output shaft 14) continuously changes.

  The output shaft 14 is rotatably supported on the transmission case 22 by a bearing. Referring to FIG. 1, output shaft 30 is provided with output gear 30, and output shaft 14 and output gear 30 rotate integrally.

  A first intermediate gear 31 meshes with the output gear 30. The first intermediate gear 31 is fixed to an intermediate shaft 32 disposed in parallel with the output shaft 14. A second intermediate gear 33 is fixed to the intermediate shaft 32. The second intermediate gear 33 meshes with external teeth 4 a provided on the differential gear 4.

  The continuously variable transmission 1 includes a control device 34 that includes an electronic unit including a CPU, a memory, and the like. The control device 34 receives signals of predetermined vehicle information such as an operation amount signal of the driver's accelerator pedal 6 and a traveling speed signal of the vehicle, and based on the received signals, the control unit 34 of the continuously variable transmission 1 held in the memory. The operation of the drive pulley 11, the driven pulley 12, the forward clutch 20 and the reverse brake 21 is controlled by executing the control program by the CPU.

  The control device 34 includes a contact frequency calculation unit, a natural frequency request unit, a resonance region determination unit, and a winding radius control unit. The contact frequency calculation unit calculates the contact frequency based on the rotation speed of the endless member 13. The contact frequency is defined as the frequency of the fixed driven half generated when the fixed driven half 26 and the element 28 come into contact with each other.

  The natural frequency supply unit performs processing for reading the natural frequencies of the fixed driven half 26 and the output shaft 14 which are obtained in advance by experiments and stored in a storage device such as a memory. The resonance region determination unit determines whether the contact frequency is a region that resonates in accordance with the natural frequency of the fixed driven half 26 and the output shaft 14 (pulley resonance region).

  By the way, the endless member 13 made of a metal belt is configured by arranging a plurality of elements 28 in the circumferential direction, so that the elements 28 are successively engaged with the drive pulley 11 and the driven pulley 12, and the drive pulley 11 and the driven pulley 13 are driven. The pulley 12 vibrates. The frequency characteristics of the vibrations of the drive pulley 11 and the driven pulley 12 generated by the engagement of the element 28 depend on the period (the engagement frequency) at which the element 28 is engaged with the drive pulley 11 and the driven pulley 12.

  As shown in FIG. 3A, the plate thickness t (the thickness in the circumferential direction of the endless member 13) of the m elements 28 (shown simply as 8 in FIG. 3) arranged in the circumferential direction of the endless member 13 Is uniformly set, the frequency of the collision (biting frequency) generated by the biting of the element 28 per rotation of the endless member 13 is as shown in FIGS. 3B and 3C. It becomes a regular waveform depending on the plate thickness t of 28.

  The biting frequency varies depending on the rotation speed of the endless member 13. As shown in FIG. 3D, the frequency characteristics of the vibrations of the drive pulley 11 and the driven pulley 12 generated by the biting frequency are such that the frequency at which the frequency per revolution of the endless member 13 is m is the rotational speed of the endless member 13. When the frequency changes due to the change and matches the natural frequency of the drive pulley 11 or the driven pulley 12, the peak value of the amplitude greatly increases due to resonance, and the noise of the continuously variable transmission 1 increases.

  In particular, when the vibration peak value coincides with the natural frequencies of the fixed drive half 24 and the pulley shaft 23, the fixed driven half 26, and the output shaft 14, the noise is further increased by resonance. This is probably because the movable drive half 25 and the movable driven half 27 are provided with hydraulic chambers 25a and 27a, and the vibration is attenuated by the oil in the hydraulic chambers 25a and 27a.

  Further, as shown in FIG. 4, the element 28 collides with the drive pulley 11 and the driven pulley 12 to generate vibration, and the vibration at this time is the side located radially outward (in FIG. As a result of the experiment (vibration eigenvalue analysis simulation), it was found that the noise generated by the element 28 located on the right side is larger.

  In addition, it has been found from experiments that when the vehicle is traveling at a low speed, the driver's discomfort tends to increase compared to when the vehicle is traveling at a high speed.

  Based on these experimental results, in the continuously variable transmission control device 34 of the present embodiment, the continuously variable transmission 1 is controlled by a winding radius control unit that executes the processing shown in the flowchart of FIG. Specifically, first, in STEP 1, it is confirmed whether the vehicle is traveling and is in an idle stop state (in-travel idle stop state). When the vehicle is in the idle stop state during traveling, the process proceeds to STEP 2 to check whether the rotational speed of the endless member 13 made of a metal belt is in a region where the resonance occurs (pulley resonance region).

  When the rotational speed of the endless member 13 is in the resonance region, the process proceeds to STEP 3 to check whether the winding radius of the endless member 13 is the position of the antinode of resonance.

  Here, as shown in FIG. 6, “resonance antinode” means the fixed driven half that maximizes the change in the amplitude of the fixed driven half 26 (the amount of change in the rotational center axis direction of the fixed driven half 26). It is defined as a part of the body 26. In FIG. 6, the change in amplitude is greatly expressed in order to make the vibration of the fixed driven half 26 easy to understand.

  Referring to FIG. 5, when the winding radius of endless member 13 is the position of the antinode of resonance, the process proceeds to STEP 4, and control device 34 shifts using a normal gear ratio control map stored in the memory. The ratio is controlled and the current process is terminated. The control device 34 executes the process of the flowchart of FIG. 5 at a predetermined cycle (for example, 10 ms).

  If it is not the idling stop state during traveling in STEP1, the process proceeds to STEP4, and the control device controls the gear ratio using the normal gear ratio control map, and ends the current process. When the rotational speed of the endless member 13 is not in the resonance region in STEP2, the process proceeds to STEP4, and the control device controls the gear ratio using a normal gear ratio control map, and ends the current process.

  If the winding radius of the endless member 13 is not at the resonance antinode position in STEP3, the process proceeds to STEP5, and the transmission ratio is controlled so that the endless member 13 contacts the fixed driven half 26 at the resonance antinode position. This processing is terminated. When the gear ratio is controlled in STEP 5, for example, an oil pump provided on the output shaft side, an electric oil pump, an accumulator, or the like may be used as the hydraulic pressure source.

  FIG. 7 is a timing chart showing the operation of the control device 34 of the continuously variable transmission 1 of the present embodiment. The solid line in FIG. 7A represents the rotational speed Ne (rpm) of the crankshaft 2a of the internal combustion engine 2, and the alternate long and short dash line in FIG. 7A represents the vehicle traveling speed (vehicle speed (km / h)). The solid line in FIG. 7B indicates the gear ratio (ratio. The rotational speed of the input shaft 9 / the rotational speed of the output shaft 14), and the alternate long and short dash line in FIG. 7B indicates the rotational speed (belt peripheral speed) of the endless member 13 made of a metal belt. (M / s)).

  In the present embodiment, the rotational speed of the endless member 13 is obtained by multiplying the rotational speed of the drive pulley 11 and the driven pulley 12 by the pitch radius of the endless member 13. Specifically, the rotational speed of the endless member 13 is defined as the speed of the rocking edge portion 28b (see FIGS. 2 and 3A) formed in the element 28 in the traveling direction of the endless member 13, and drives Rpdr. The pitch line radius of the endless member 13 at the pulley 11, ωdr as the rotational angular velocity of the drive pulley 11, Rpdn as the pitch line radius of the endless member 13 at the driven pulley 12, and ωdn as the rotational angular velocity of the driven pulley 12, The rotational speed Vb (circumferential speed) of the endless member 13 can be obtained from the equation (1).

  Vb = Rpdr × ωdr = Rpdn × ωdn (1).

  However, the method for detecting the rotational speed of the endless member 13 is not limited to this. For example, the rotational speed of the endless member 13 may be detected directly.

  The hatched area shown in FIG. 7B indicates a rotation speed area (resonance area) of the endless member 13 in which resonance occurs with the fixed driven half body 26. In the idling stop state during traveling, the control device 34 of the present embodiment constantly controls the gear ratio of the continuously variable transmission 1 so that the rotational speed of the endless member 13 does not enter the resonance region as much as possible.

  And the control apparatus 34 performs the process of FIG. 5 only when it is necessary to put the rotational speed of the endless member 13 in a resonance area | region. As is apparent from the change in the traveling speed of the vehicle in FIG. 7A, in the present embodiment, when the vehicle is in a slow deceleration state, idling stop is performed during traveling, and the processing in FIG. 5 is performed. Yes. Note that the gear ratio of the continuously variable transmission 1 is controlled by the control device 34 so that the resonance region can escape as early as possible.

  According to the control device 34 of the continuously variable transmission 1 of the present embodiment, the contact frequency (the frequency of the fixed driven half generated when the fixed driven half 26 and the element 28 come into contact) is the fixed driven half. In the case of the pulley resonance region that resonates in accordance with the natural frequency of 26 (shaded region in FIG. 7B), the endless member 13 is positioned at the radial position of the fixed driven half 26 where the amplitude of the natural frequency is maximized. The gear ratio is controlled so that the element 28 contacts, and the winding radius of the endless member 13 is controlled. Thereby, the vibration of the continuously variable transmission 1 can be suppressed and the noise of the continuously variable transmission 1 can be reduced.

  Further, the continuously variable transmission 1 according to the present embodiment has a noise caused by resonance at the abutting portion by bringing the abutting portion formed of an elastic body between the endless member and the pulley as in the conventional product. It is not what suppresses. Therefore, according to the continuously variable transmission 1 of the present embodiment, it is possible to prevent the noise suppression function from being lowered due to secular change as in the conventional product. Further, since the abutment portion is not provided, it is possible to improve the response by reducing the inertia of the continuously variable transmission 1, and to increase the size and weight of the continuously variable transmission 1. Therefore, it contributes to improved fuel efficiency and vehicle mountability.

  In the present embodiment, the continuously variable transmission 1 is mounted on a vehicle, the drive source is the internal combustion engine 2, and the continuously variable transmission 1 includes a space between the internal combustion engine 2 and the pulley shaft 23. There is provided an engagement mechanism (forward clutch 20 and reverse brake 21) that can be switched between a transmission state in which the driving force is transmitted and a released state in which this transmission is cut off. .

  In the present embodiment, the power transmission between the internal combustion engine 2 and the pulley shaft 23 can be cut off by releasing both the forward clutch 20 and the reverse brake 21. The vehicle of this embodiment is provided with a traveling internal combustion engine stop mechanism that stops the internal combustion engine when the traveling speed of the vehicle is less than a predetermined value.

  The control device 34 includes a traveling internal combustion engine operation detecting unit that detects whether or not the vehicle is traveling while the internal combustion engine is stopped by the operation of the traveling internal combustion engine stop mechanism, and the vehicle stops the internal combustion engine. And an engagement mechanism release portion that releases the engagement mechanism when the vehicle is traveling.

  When the control device 34 controls the winding radius according to the winding radius control unit according to the flowchart of FIG. 5, the control device 34 uses the engagement mechanism releasing unit to engage the engagement mechanism (the forward clutch 20 and the reverse brake 21). To release.

  With this configuration, when the internal combustion engine that is traveling is stopped (so-called idling stop state during traveling), the control device 34 can output the fixed driven half 26 and the output in the resonance region (shaded region in FIG. 7B). Control is performed to bring the endless member 13 into contact with the position where the amplitude of the natural frequency of the shaft 14 is maximized. When the internal combustion engine 2 is stopped, power transmission between the internal combustion engine 2 and the drive pulley 11 is cut off by the engagement mechanism (the forward clutch 20 and the reverse brake 21).

  Therefore, the speed ratio of the continuously variable transmission 1 (the rotational speed of the drive pulley 11 / the rotational speed of the driven pulley 12) is considered without considering the influence of the driver's uncomfortable feeling that occurs when the rotational speed of the internal combustion engine 2 changes greatly. Speed) can be controlled, and the degree of freedom in controlling the winding radius of the endless member 13 in the control device 34 of the present embodiment can be increased.

1 continuously variable transmission 2 internal combustion engine (driving drive source)
2a Crankshaft 3 Torque converter 3a Pump impeller 3b Turbine runner 3c Stator 3d Lock-up clutch 4 Differential gear 4a External gear 5 Drive wheel 6 Accelerator pedal 9 Input shaft 10 Forward / reverse switching mechanism 11 Drive pulley 11a Pulley groove 12 Driven pulley 12a Pulley groove 13 Endless member 14 Output shaft 15 Sun gear 16 Ring gear 17 Carrier 18 First pinion 19 Second pinion 20 Forward clutch 21 Reverse brake 22 Transmission case 23 Pulley shaft 24 Fixed drive half 25 Movable drive half 25a Hydraulic chamber 26 Fixed Driven half 27 Movable driven half 27a Hydraulic chamber 28 Element 28a Recess 28b Locking edge 29 Metal ring 30 Output gear 31 First intermediate gear 32 Intermediate shaft 33 Second intermediate gear 34 Control Location

Claims (2)

A pulley shaft to which a driving force from a driving source is transmitted;
An output shaft disposed parallel to the pulley shaft;
A drive pulley composed of a movable drive half movable in the axial direction with respect to the pulley shaft and a fixed drive half fixed to the pulley shaft;
A driven pulley composed of a movable driven half movable in the axial direction with respect to the output shaft and a fixed driven half fixed to the output shaft;
A plurality of elements in contact with the drive pulley and the driven pulley, and an endless member having a ring for holding the plurality of elements;
A continuously variable transmission in which the endless member is wound between the drive pulley and the driven pulley;
A control device used for
The frequency of the fixed drive half or the fixed driven half generated when the fixed drive half or the fixed driven half and the element come into contact is defined as a contact frequency,
A contact frequency calculation unit that calculates the contact frequency based on the rotation speed of the endless member;
A natural frequency requesting unit for obtaining a natural frequency of the fixed drive half and the pulley shaft or the fixed driven half and the output shaft;
A resonance region determination unit that determines whether the contact frequency is a pulley resonance region that resonates in accordance with the natural frequency;
When the resonance region determination unit determines that the resonance region is in the resonance region, the endless member is wound so that the endless member contacts the radial position of the drive pulley or the driven pulley where the amplitude of the natural frequency is maximum. A control device for a continuously variable transmission, comprising: a winding radius control unit that controls a winding radius. A control device for a continuously variable transmission according to claim 1,
The continuously variable transmission is mounted on a vehicle,
The drive source is an internal combustion engine;
The continuously variable transmission is positioned on a power transmission path between the internal combustion engine and the pulley shaft so that the state can be switched between a transmission state in which driving force is transmitted and a released state in which the transmission is cut off. Joint mechanism is provided,
The vehicle is provided with a traveling internal combustion engine stop mechanism that stops the internal combustion engine when the traveling speed of the vehicle is less than a predetermined value,
The controller is
A running internal combustion engine operation detecting unit that detects whether the vehicle is running while the internal combustion engine is stopped by the operation of the running internal combustion engine stop mechanism;
An engagement mechanism releasing portion for releasing the engagement mechanism when the vehicle is in a state of traveling while stopping the internal combustion engine;
With
The control device for a continuously variable transmission, wherein when the winding radius is controlled by the winding radius control unit, the engagement mechanism releasing unit releases the engagement mechanism.