JP2016148419A - Control device of belt-type continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device of a belt-type continuously variable transmission which can reduce noise generated by a collision of a pin with a pulley in a chain belt.SOLUTION: In a control device of a belt-type continuously variable transmission having a pair of pulleys, a chain belt wound to the pulleys, and an actuator which can control the tension of the chain belt, the tension of the chain belt is reduced more than tension which is defined so as to suppress the generation of a slide on a power transmission face when torque is transmitted by the chain belt in the case that power acting on the chain belt is smaller than a preset prescribed value (step S3).SELECTED DRAWING: Figure 1

Description

  The present invention relates to a control device for a belt-type continuously variable transmission including a pair of pulleys and a chain belt wound around the pulleys.

  Patent Document 1 describes a noise reduction device for a belt-type continuously variable transmission that is configured to suppress noise of a certain frequency that occurs between a belt and a pulley. Specifically, a running state in which abnormal noise is generated is determined in advance based on the torque input to the belt type continuously variable transmission, the transmission, the vehicle speed, or the like. The clamping pressure to be clamped is configured to be higher than the normally set clamping pressure.

  Patent Document 2 describes a belt-type continuously variable transmission that includes a stabilizer for suppressing vibration of a string portion spanned between pulleys. This stabilizer is formed in a cylindrical shape and is configured so that the string part of the belt is inserted therein, and when the string part vibrates, the belt and the stabilizer come into contact with each other so as to reduce vibration. It is configured. Further, the position of the center of gravity of the stabilizer and the support portion that holds the stabilizer so as to be able to swing are shifted in the traveling direction of the belt so as to apply tension to the string portion.

JP 2010-196827 A JP 2011-112155 A

  By the way, the chain belt is configured by connecting a plurality of plate-like links in an annular shape with pins. In a belt-type continuously variable transmission configured to transmit torque by pinching the chain belt with a pulley, the pin is intermittently pinched between the pulleys during torque transmission. When the pin is sandwiched between the pulleys, the pin and the pulley collide with each other, so that there is a possibility that abnormal noise may be generated due to the collision.

  The present invention has been made paying attention to the above technical problem, and provides a control device for a belt-type continuously variable transmission capable of reducing abnormal noise caused by a pin in a chain belt colliding with a pulley. It is intended to provide.

  In order to achieve the above object, the invention according to claim 1 is configured so that the fixed sheave integrated with the rotating shaft and the rotating shaft can rotate together with the rotating shaft and move in the axial direction of the rotating shaft. A pair of pulleys each having a movable sheave fitted to the rotating shaft, a plurality of plate-like links, and fitting holes formed in the links so as to connect the links in an annular manner, and both end faces are In a belt-type continuously variable transmission control device comprising: a chain belt having a pin serving as a power transmission surface in contact with each sheave; and an actuator capable of controlling the tension of the chain belt. When the power to be transmitted is less than a predetermined value, the power transmission surface is used to transmit the tension of the chain belt by the chain belt. And it is characterized in that it is configured to reduce than the tension which is determined to prevent the slippage.

  According to the present invention, when the power acting on the chain belt is less than a predetermined value, the chain belt tension is prevented from slipping when the torque is transmitted by the chain belt. The tension is determined to be less than the predetermined tension. Therefore, the load when the pin comes into contact with each pulley can be reduced. As a result, it is possible to reduce abnormal noise caused by a pin colliding with each pulley.

It is a flowchart for demonstrating the example of control of the control apparatus which concerns on this invention. It is sectional drawing for demonstrating an example of a structure of the belt-type continuously variable transmission in this invention. It is an enlarged view for demonstrating an example of a structure of a chain belt.

  A belt type continuously variable transmission that can be a subject of the present invention includes a pair of pulleys each having a fixed sheave and a movable sheave, and a chain belt having a power transmission surface that contacts each sheave. An example of the configuration of the belt-type continuously variable transmission configured as described above is shown in FIG. A belt-type continuously variable transmission (hereinafter referred to as CVT) 1 shown in FIG. 2 is configured substantially the same as a conventionally known one, and includes an input shaft 2 to which torque is transmitted from a power source such as an engine, The primary pulley 3 connected to the input shaft 2, the output shaft 4 for transmitting torque to an output member such as a drive wheel, the secondary pulley 5 connected to the output shaft 4, and the pulleys 3 and 5 are wound around It is comprised by the endless chain belt 6 hung. The input shaft 2 and the output shaft 4 are arranged in parallel.

  The primary pulley 3 includes a conical first fixed sheave 7 and a first movable sheave 8, and the first fixed sheave 7 is formed integrally with the input shaft 2. Further, the first movable sheave 8 rotates integrally with the input shaft 2 and is engaged with the input shaft 2 by a spline or the like so that it can move in the axial direction. Specifically, a hollow first boss portion 9 extending to the back side (left side in the drawing) is integrally formed on the inner peripheral portion of the first movable sheave 8, and the first boss portion The inner peripheral surface of 9 and the outer peripheral surface of the input shaft 2 are spline-engaged. The conical surfaces 10 and 11 of the sheaves 7 and 8 are arranged to face each other in the axial direction of the input shaft 2, and the first V groove 12 is formed by the conical surfaces 10 and 11.

  Further, a first cylindrical portion 13 projecting to the back side is formed on the outer peripheral portion of the first movable sheave 8, and the first cylinder 14 is in liquid-tight contact with the inner peripheral surface of the first cylindrical portion 13. Is fitted to the input shaft 2. The first cylinder 14 is a member formed in an annular shape, and a hollow portion thereof is fitted to the input shaft 2. The first cylinder 14 is formed in a mortar shape, and an outer peripheral portion thereof is bent so as to face outward, and an end surface thereof faces the inner peripheral surface of the first cylindrical portion 13. A first seal member 15 for sealing the first cylinder 14 and the first cylindrical portion 13 in a liquid-tight manner is provided between the end surface and the inner peripheral surface of the first cylindrical portion 13. . The first cylinder 14 is positioned in the axial direction by being fitted from the end of the input shaft 2 and brought into contact with a stepped portion formed on the input shaft 2.

  By forming the first cylinder 14 and the first cylindrical portion 13 as described above, the space 16 (hereinafter referred to as a first hydraulic chamber) 16 surrounded by those members is maintained in a liquid-tight state. In the example shown in FIG. 2, the first movable sheave 8 is configured to be pressed toward the first fixed sheave 7 by supplying oil to the first hydraulic chamber 16. That is, it is configured to function as a hydraulic actuator that applies a pressing force to the first movable sheave 8 by hydraulic pressure. By controlling the amount of oil supplied to the first hydraulic chamber 16, the transmission ratio of the CVT 1 is controlled.

  The secondary pulley 5 shown in FIG. 2 is also configured similarly to the primary pulley 3. The configuration will be briefly described. In the secondary pulley 5 shown in FIG. 2, a conical second fixed sheave 17 is integrally formed at one end portion (left end portion in the drawing) of the output shaft 4. Further, a second boss portion 19 is formed to extend on the back side of the conical second movable sheave 18, and the second boss portion 19 and the output shaft 4 are spline-engaged. That is, the second movable sheave 18 is engaged with the output shaft 4 so as to rotate together with the output shaft 4 and move in the axial direction. The conical surface 20 of the second fixed sheave 17 and the conical surface 21 of the second movable sheave 18 are arranged to face each other in the axial direction, and the second V groove 22 is formed by the conical surfaces 20 and 21. Has been.

  In addition, a second cylindrical portion 23 projecting to the back side is formed on the outer peripheral portion of the second movable sheave 18, and the second cylinder 24 is in liquid-tight contact with the inner peripheral surface of the second cylindrical portion 23. Is fitted to the output shaft 4. The second cylinder 24 is a member formed in an annular shape, and its hollow portion is fitted to the output shaft 4. The second cylinder 24 is formed in a mortar shape, and an outer peripheral portion thereof is bent so as to face outward, and an end surface thereof is opposed to an inner peripheral surface of the second cylindrical portion 23. A second seal member 25 is provided between the end surface and the second cylindrical portion 23 in order to seal the end surface and the second cylindrical portion 23 in a liquid-tight manner. Further, a return spring 26 that presses the second movable sheave 18 toward the second fixed sheave 17 is provided between the second movable sheave 18 and the second cylinder 24. The second cylinder 24 is disposed so as not to contact the tip surface of the second boss portion 19 when the second movable sheave 18 is farthest from the second fixed sheave 17, and the second cylinder 24 is The positioning is performed in the axial direction by fitting from the end of the output shaft 4 and bringing it into contact with the stepped portion formed on the output shaft 4.

  By forming the second cylinder 24 and the second cylindrical portion 23 as described above, a space 27 (hereinafter referred to as a second hydraulic chamber) 27 surrounded by those members is maintained in a liquid-tight state. In the example illustrated in FIG. 2, the second movable sheave 18 is configured to be pressed toward the second fixed sheave 17 by supplying oil to the second hydraulic chamber 27. That is, it is configured to function as a hydraulic actuator that applies a pressing force to the second movable sheave 18 by hydraulic pressure. By controlling the hydraulic pressure supplied to the second hydraulic chamber 27, the tension of the chain belt 6 and the transmission torque capacity of the CVT 1 are controlled.

  An output gear 28 is spline-engaged with the other end portion of the output shaft 4 so that torque is transmitted to drive wheels (not shown) via the output gear 28.

  Here, an example of the structure of the chain belt 6 wound around the pulleys 3 and 5 will be described. FIG. 3 is a diagram for explaining the configuration, in which the longitudinal direction of the chain belt 6 is shown in the horizontal direction and the thickness direction of the chain belt 6 is shown in the vertical direction. The chain belt 6 shown in FIG. 3 is configured in the same manner as the conventionally known chain belt 6, and is configured by connecting a plurality of links 29 with pins 30. The link 29 is a plate member formed in an oval shape, and first through holes 31 into which pins 30 are inserted are formed at both ends thereof. In addition, the 2nd through-hole 32 is formed in the center part, and in order to suppress that the pin 30 approachs into the 2nd through-hole 32, the width | variety of the 2nd through-hole 32 is larger than the outer diameter of the pin 30. Is also narrowly formed. Two pins 30, 30 are inserted into the first through hole 29. These pins 30 have an elliptical cross-sectional shape. Furthermore, the surfaces opposed to each other are separated from a predetermined position in the thickness direction of the chain belt 6.

  The link 29 configured as described above is shifted by the distance of the first through-hole 31 with respect to the adjacent link 29 and stacked in the width direction of the chain belt 6, and thereafter, both end portions of the pin 30 are Inserted and assembled from the link 29 so as to protrude in the width direction of the chain belt. Therefore, when the chain belt 6 is wound around the pulleys 3 and 5 and transmits torque, both ends of the pin 30 come into contact with the pulleys 3 and 5. That is, the tip surface of the pin 30 is a power transmission surface. Note that the two adjacent pins 30 and 30 can be relatively rotated, and the link 29 and the pin 30 can be relatively rotated.

  In the CVT 1 configured as described above, the pin 30 is intermittently sandwiched between the V grooves 12 and 22 during torque transmission. In other words, the pin 30 and each pulley 3 and 5 contact intermittently. Therefore, there is a possibility that an abnormal noise is generated due to the pin 30 colliding with each of the pulleys 3 and 5 as described above. The control device according to the present invention is configured to reduce such abnormal noise. Specifically, when the vehicle is coasting or when the vehicle is decelerating by applying a braking force with a brake, when the power acting on the chain belt 6 is relatively low, the above abnormal noise is generated. It is comprised so that generation | occurrence | production may be suppressed.

  An example of the control is shown in FIG. In the control shown in FIG. 1, it is first determined whether or not the load (power) acting on the chain belt 6 is less than a predetermined threshold value α (step S1). This step S1 is a step for determining whether or not the tension of the chain belt 6 can be reduced. Therefore, the load acting on the chain belt 6 is determined by the magnitude of the torque regardless of the direction of the torque, such as torque acting in the direction of increasing the speed of the chain belt 6 or torque acting in the direction of reducing the speed. It is preferable to do. Therefore, in the example shown in FIG. 1, is the load acting on the chain belt 6 larger than the first threshold “−α” that is a negative value and less than the second threshold “+ α” that is a positive value? It is decided to judge whether or not. The load acting on the chain belt 6 can be calculated based on signals detected by various sensors such as the accelerator opening and the vehicle speed.

  If the load acting on the chain belt 6 is equal to or greater than a predetermined threshold α and a negative determination is made in step S1, it means that it is necessary to pinch the chain belt 6 and transmit torque. . Therefore, in this control example, the tension of the chain belt 6 becomes a tension that is determined so as to suppress slippage when torque is input to the CVT 1 (hereinafter referred to as a tension in normal control). The hydraulic pressure in the second hydraulic chamber 27, that is, the clamping pressure of the chain belt 6 is controlled, and an amount of lubricating oil corresponding to the torque transmitted as in the conventional case is supplied to the torque transmission surface (step S2).

  On the other hand, if the load acting on the chain belt 6 is less than the predetermined threshold value α and the determination in step S1 is affirmative, there is no need to clamp the chain belt 6 and transmit torque. Therefore, in this control example, the tension of the chain belt 6 is made lower than the tension in the normal control, and the hydraulic pressure in the second hydraulic chamber 27 is lowered so as to be close to “0” (step S3). On the other hand, even if the hydraulic pressure in the second hydraulic chamber 27 is lowered as described above, when the vehicle is traveling or when the engine is driven, the pulleys 3 and 5 are rotating, There is a possibility that slip occurs on the contact surface between the pulleys 3 and 5 and the pin 30. Therefore, in step S3, in order to further prevent the durability of the pulleys 3 and 5 and the pin 30 from being lowered due to slippage on the contact surface between the pulleys 3 and 5 and the pin 30 as described above. A larger amount of oil than the lubricating oil supplied in step S2 is supplied to the torque transmission surface.

  As described above, when the load acting on the chain belt 6 is relatively small, the tension of the chain belt 6 is decreased below the tension in the normal control and is reduced to be close to “0”, so that the pin 30 The load that collides with the pulleys 3 and 5 can be reduced. As a result, it is possible to suppress the generation of abnormal noise due to such a collision. Further, even if slippage occurs between the pin 30 and the pulleys 3 and 5 by reducing the tension of the chain belt 6, durability of the pins 30 and the pulleys 3 and 5 can be improved by supplying a large amount of lubricating oil. It can suppress that property falls. Further, by reducing the hydraulic pressure in the second hydraulic chamber 27, it is possible to reduce the load of the oil pump that is the hydraulic power source, that is, to reduce the power loss, so that the fuel efficiency can be improved. Moreover, since the other member for reducing the above abnormal noise is not provided, it is possible to suppress the increase in the vehicle weight, and as a result, suppress the deterioration of fuel consumption. be able to.

  DESCRIPTION OF SYMBOLS 1 ... Belt type continuously variable transmission (CVT), 2 ... Input shaft, 3 ... Primary pulley, 4 ... Output shaft, 5 ... Secondary pulley, 6 ... Chain belt, 7, 17 ... Fixed sheave, 8, 18 ... Movable sheave 16, 27 ... Hydraulic chamber, 29 ... Link, 30 ... Pin.

Claims (1)

A pair of pulleys each having a fixed sheave integrated with the rotating shaft and a movable sheave fitted to the rotating shaft so as to rotate integrally with the rotating shaft and move in the axial direction of the rotating shaft When,
A chain belt having a plurality of plate-shaped links and pins that are fitted into connecting holes formed in the links to connect the links in an annular shape and have both end surfaces in contact with the sheaves to serve as power transmission surfaces;
In a control device for a belt-type continuously variable transmission comprising an actuator capable of controlling the tension of the chain belt,
When the power acting on the chain belt is less than a predetermined value, the chain belt tension is controlled to prevent slippage on the power transmission surface when torque is transmitted by the chain belt. A control device for a belt-type continuously variable transmission, wherein the control device is configured to reduce the tension determined by the above.

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