JP2010053897A - Belt-type continuously variable transmission - Google Patents

Abstract

A belt type continuously variable transmission capable of further improving fuel consumption is provided.
A fixed sheave 52, a movable sheave 53 movable in the axial direction of the pulley shaft, a hydraulic chamber 54 for applying a force in the axial direction of the pulley shaft to the movable sheave by operating oil injected therein, and operation A switching mechanism 100 that switches between a state in which hydraulic oil can flow between the oil supply / discharge means and the hydraulic chamber and a state in which the distribution of the hydraulic oil is prohibited; a closed control mode that confines the hydraulic pressure in the hydraulic chamber; A hydraulic control mode that adjusts the amount of hydraulic oil in the hydraulic chamber so as to obtain an input gear ratio, and a hydraulic control unit that adjusts the hydraulic pressure in the hydraulic chamber by an oil supply / discharge unit When it is detected that the gear ratio is not fixed in the closed control mode, the use of the closed control mode is prohibited, and the return process of the switching mechanism is performed while controlling the gear ratio in the hydraulic control mode.
[Selection] Figure 2-2

Description

  The present invention relates to a belt-type continuously variable transmission, and more particularly to a belt-type continuously variable transmission in which a gear ratio is adjusted by the pressure of hydraulic oil in a hydraulic chamber.

  2. Description of the Related Art Conventionally, there is a belt type continuously variable transmission in which hydraulic oil is supplied to a hydraulic chamber and a gear ratio is adjusted by the pressure of the hydraulic oil. For example, Patent Document 1 discloses that a supply-side valve that permits the supply of hydraulic oil from the outside of the hydraulic chamber to the hydraulic chamber, and the movable sheave from the hydraulic chamber to the outside when the position in the axial direction with respect to the fixed sheave is constant. Describes a belt-type continuously variable transmission that includes a discharge-side control valve that prohibits the discharge of hydraulic oil.

  Further, in Patent Document 2, as a hydraulic pressure control device for a planetary gear type automatic transmission operated by hydraulic pressure, the hydraulic pressure control device is arranged in a hydraulic pressure path between a clutch of the automatic transmission and a first hydraulic pressure generating means. A first on-off valve that opens and closes the pressure path and connects the first hydraulic pressure generating means and the clutch when the engine is driven, and shuts off the connection between the first hydraulic pressure generating means and the clutch when the engine is stopped. And a device including a fail-safe mechanism capable of supplying hydraulic pressure to the clutch by the first hydraulic pressure generating means when the engine is driven when the first on-off valve is fixed in a closed state. ing.

JP 2006-300270 A JP 2002-168330 A

  As in the device described in Patent Document 1, by providing a discharge-side control valve that prohibits hydraulic oil from being discharged from the hydraulic chamber, the oil pump is operated when the speed ratio is fixed, and the hydraulic chamber is kept constant. Therefore, the power loss of the oil pump can be reduced, and the gear ratio can be more reliably fixed. Also, in the case of a continuously variable transmission, when a discharge-side control valve is fixed in a closed state by providing a spare fail-safe mechanism for adjusting the hydraulic pressure as described in Patent Document 2. It becomes possible to cope.

  Here, the discharge side control valve, that is, the switching mechanism of the present invention, may be fixed in a state where hydraulic oil can be supplied and discharged from the outside to the hydraulic chamber. If the switching mechanism is fixed in the OFF state, the gear ratio cannot be fixed, and the fuel efficiency is deteriorated. On the other hand, Patent Document 1 does not describe the fixing of the switching mechanism. Patent Document 2 also describes only the case where the switching mechanism is fixed in a closed state, and does not describe the case where the switching mechanism is fixed in a state where hydraulic oil can be supplied and discharged.

  The present invention has been made in view of the above, and an object thereof is to provide a belt-type continuously variable transmission that can further improve fuel efficiency.

  In order to solve the above-described problems and achieve the object, the present invention includes a fixed sheave and a movable sheave that moves relative to the fixed sheave, and two pulleys that can adjust a distance between the fixed sheave and the movable sheave, A belt-type continuously variable transmission that has a belt that is hung between two pulleys and that transmits the rotation of one pulley to the other pulley, and that changes the gear ratio by relatively changing the diameter of the two pulleys. A pulley shaft connected to the power generating means and rotating together with the power generating means; a fixed sheave connected to the pulley shaft; and a position of the pulley shaft facing the fixed sheave; A movable sheave that is movable in the axial direction of the pulley shaft, a hydraulic chamber that is provided in the pulley shaft and that applies hydraulic force to the movable sheave in the axial direction of the pulley shaft by hydraulic oil injected into the pulley shaft; A hydraulic fluid supply means for supplying the hydraulic oil to the hydraulic chamber and discharging the hydraulic oil from the hydraulic chamber; and the hydraulic chamber and the hydraulic oil supply / discharge means between the hydraulic chamber and the hydraulic oil supply / discharge means. A switching mechanism that is disposed in the hydraulic oil flow path and switches between a state in which the hydraulic oil can flow between the hydraulic oil supply / discharge means and the hydraulic chamber, and a state in which the distribution is prohibited; and the switching mechanism The hydraulic oil supply and discharge means and the hydraulic chamber are prohibited from flowing between the hydraulic oil chamber, a closed control mode for confining the hydraulic pressure in the hydraulic chamber inside, and the hydraulic fluid supply and discharge means by the switching mechanism. A hydraulic control mode for adjusting the hydraulic pressure in the hydraulic chamber by the hydraulic oil supply and discharge means and making the hydraulic fluid flowable between the hydraulic chamber and the input gear ratio, Hydraulic oil supply / discharge Hydraulic control means for adjusting the amount of the hydraulic oil in the hydraulic chamber by controlling the operation of the stage and the switching mechanism, and the hydraulic control means has the gear ratio fixed in the closed control mode. Is detected, the switching control mode is disabled, the hydraulic control mode is switched to, the speed change ratio is controlled in the hydraulic control mode, and the switching mechanism is returned to the hydraulic control mode. When the gear ratio becomes constant, the closed control mode can be used, and the switching mechanism can be returned by the switching mechanism between the hydraulic oil supply / discharge means and the hydraulic chamber. It is a process for pushing out the switching mechanism so as to inhibit the movement.

  The belt type continuously variable transmission according to the present invention can improve the fuel efficiency and further reduce the possibility of shocking the vehicle.

  Hereinafter, the present invention will be described in detail with reference to the drawings. The present invention is not limited by the best mode for carrying out the invention (hereinafter referred to as an embodiment). In addition, constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art, those that are substantially the same, and those in a so-called equivalent range.

  FIG. 1 is a conceptual diagram showing an overall configuration of a power transmission portion of a vehicle provided with a belt type continuously variable transmission according to the present embodiment. FIGS. 2-1 and 2-2 are conceptual diagrams showing an enlarged schematic configuration of the belt-type continuously variable transmission shown in FIG. 1, and FIG. 3 is a conceptual diagram schematically showing the schematic configuration of the hydraulic control device. FIG. Here, FIG. 2-1 shows a state where a switching mechanism 100 described later is open, and FIG. 2-2 shows a state where the switching mechanism 100 described later is closed.

  As shown in FIG. 1, the power transmission mechanism of the vehicle 10 includes a belt-type continuously variable transmission 22, an internal combustion engine 12, a torque converter 16, a forward / reverse switching mechanism 20, a speed reduction device 24, and a differential device 28. And comprising. In the internal combustion engine 12, a piston reciprocates in the central axis direction of a cylinder formed in a cylindrical shape, and outputs rotation from a crankshaft 14 that converts the reciprocating motion of the piston into a rotational motion. The internal combustion engine 12 is not limited to a so-called reciprocating internal combustion engine including a piston and a cylinder. The internal combustion engine 12 only needs to output a rotational force. For example, the internal combustion engine 12 may be a rotary internal combustion engine or a motor.

  The torque converter 16 is a kind of fluid clutch, and transmits the rotation extracted from the internal combustion engine 12 to the forward / reverse switching mechanism 20 by hydraulic oil. The torque converter 16 amplifies the torque extracted from the internal combustion engine 12.

  The forward / reverse switching mechanism 20 is a mechanism for transmitting the rotation taken out from the torque converter 16 to the belt-type continuously variable transmission 22 and switches the direction of the rotation taken out from the torque converter 16 as necessary to change the belt-type continuously variable transmission. To the machine 22.

  The belt-type continuously variable transmission 22 changes the rotational speed input from the forward / reverse switching mechanism 20 to a desired rotational speed and outputs it. The detailed description of the belt type continuously variable transmission 22 will be described later.

  The speed reduction device 24 reduces the rotational speed of the rotation from the belt type continuously variable transmission 22 and transmits the rotation to the differential device 28.

  The differential device 28 absorbs the difference in rotational speed between the center side of the turn, that is, the inner wheel 34 and the outer wheel 34 that occurs when the vehicle 10 turns.

  A power transmission mechanism of the vehicle 10 is formed by the above components. The rotation extracted from the internal combustion engine 12 is transmitted to the torque converter 16 via the crankshaft 14. The rotation whose torque has been amplified by the torque converter 16 is transmitted to the forward / reverse switching mechanism 20 via the input shaft 18 of the torque converter 16.

  The rotation whose rotation direction is switched by the forward / reverse switching mechanism 20 is transmitted to the belt-type continuously variable transmission 22 via a primary shaft 51 as an input-side shaft. The rotation whose rotation speed has been changed by the belt-type continuously variable transmission 22 is transmitted to the speed reduction device 24.

  The rotation decelerated by the reduction device 24 is transmitted to the differential device 28 via the final drive pinion 26 of the reduction device 24 and the ring gear 30 of the differential device 28 that meshes with the final drive pinion 26.

  The rotation transmitted to the differential device 28 is transmitted to the drive shaft 32. A wheel 34 is attached to the side of the drive shaft 32 opposite to the differential device 28 side. The rotation transmitted to the drive shaft 32 is transmitted to the wheels 34. Thereby, the wheel 34 rotates, and the vehicle 10 travels when the wheel 34 transmits the rotation to the road surface.

  The belt type continuously variable transmission 22 includes a primary pulley 50, a secondary pulley 60, and a belt 80. The belt-type continuously variable transmission 22 receives rotation input to the primary pulley 50. The rotation input to the primary pulley 50 is transmitted to the secondary pulley 60. At this time, the rotation speed is adjusted.

  The rotation transmitted to the secondary pulley 60 is transmitted to the speed reducer 24. A value obtained by dividing the rotational speed of the primary shaft 51 as the input shaft by the rotational speed of the secondary shaft 61 as the output shaft is referred to as a gear ratio. Also, changing the gear ratio is hereinafter referred to as a gear change.

  In the belt-type continuously variable transmission 22, the primary pulley 50 and the secondary pulley 60 are configured in substantially the same manner. Therefore, in this embodiment, the primary pulley 50 will be mainly described.

  The primary pulley 50 includes a primary shaft 51, a primary fixed sheave 52, a primary movable sheave 53, a primary hydraulic chamber 54, a spline 55, and a primary partition wall 56. As shown in FIGS. 1, 2-1, and 2-2, the primary shaft 51 is supported by a bearing 81 and a bearing 82 so as to be rotatable coaxially with the rotation axis of the input shaft 18. Here, as shown in FIG. 1, the secondary shaft 61 is supported by a bearing 83 and a bearing 84 so as to be rotatable in parallel with the primary shaft 51.

  The primary shaft 51 is formed in a cylindrical shape. As illustrated in FIGS. 2-1 and 2-2, the primary shaft 51 rotates about the rotation axis RL. The primary fixed sheave 52 is usually formed integrally with the primary shaft 51. The primary fixed sheave 52 may be formed separately from the primary shaft 51 and fixed to the primary shaft 51. Thus configured, the primary fixed sheave 52 rotates integrally with the primary shaft 51 around the rotation axis RL. Here, a direction orthogonal to the rotation axis RL is referred to as a radial direction. The primary fixed sheave 52 is formed to protrude in the radial direction from the outer periphery of the primary shaft 51.

  Primary movable sheave 53 is formed separately from primary shaft 51. The primary movable sheave 53 has a through hole into which the primary shaft 51 is fitted. A spline 55 is formed on the inner peripheral surface of the through hole. Primary movable sheave 53 is fitted and attached to primary shaft 51 via spline 55. The primary movable sheave 53 is fitted into the primary shaft 51 so as to face the primary fixed sheave 52.

  The spline 55 supports the primary movable sheave 53 so that the primary movable sheave 53 can slide on the primary shaft 51 along the rotation axis RL of the primary shaft 51. In addition, the spline 55 transmits rotation about the rotation axis RL from the primary shaft 51 to the primary movable sheave 53. Therefore, the primary movable sheave 53 slides and moves on the primary shaft 51 by the spline 55 and rotates integrally with the primary shaft 51.

  A substantially V-shaped primary groove 80 a is formed between the primary fixed sheave 52 and the primary movable sheave 53. Further, as the primary movable sheave 53 slides on the primary shaft 51, the distance between the primary fixed sheave 52 and the primary movable sheave 53 changes. Here, as shown in FIG. 1, the secondary pulley 60 is also formed with a secondary groove 80b similar to the primary groove 80a.

  A belt 80, which is a metal endless belt, is wound between the primary groove 80a and the secondary groove 80b. The belt 80 transmits the rotation of the primary pulley 50 to the secondary pulley 60.

  As shown in FIGS. 2A and 2B, the primary hydraulic chamber 54 is a space formed by being surrounded by a primary shaft 51, a primary movable sheave 53, and a primary partition wall 56. The primary partition 56 is formed having a through hole. The primary partition wall 56 is provided on the primary shaft 51 by fitting the primary shaft 51 into the through hole. The primary partition wall 56 is provided on the side opposite to the primary fixed sheave 52 side with the primary movable sheave 53 as a boundary.

  The primary hydraulic chamber 54 pushes the primary movable sheave 53 toward the primary fixed sheave 52 side with the hydraulic oil supplied to the primary hydraulic chamber 54. Accordingly, the primary movable sheave 53 is pushed toward the primary fixed sheave 52 side along the primary shaft 51. Thereby, the primary hydraulic chamber 54 generates a clamping pressure with respect to the belt 80 wound around the primary groove 80a.

  When the primary movable sheave 53 is moved by the primary hydraulic chamber 54 and the distance between the primary movable sheave 53 and the primary fixed sheave 52 is changed, the distance between the secondary fixed sheave 62 and the secondary movable sheave 63 provided in the secondary pulley 60 is also the belt 80. It changes to keep the tension constant. Thereby, the contact radius of the belt 80 with respect to the primary pulley 50 and the contact radius of the belt 80 with respect to the secondary pulley 60 change. In this way, the belt type continuously variable transmission 22 shifts the rotation taken out from the internal combustion engine 12.

  The primary shaft 51 has a first oil passage 86. The first oil passage 86 has one end connected to a switching mechanism 100 described later, and the other end connected to the primary hydraulic chamber 54. As a result, the first oil passage 86 allows hydraulic oil to flow between the switching mechanism 100 and the primary hydraulic chamber 54. The first oil passage 86 includes a plurality of axial oil passages 88 formed in a direction along the rotation axis RL of the primary shaft 51 and a plurality of radial oil passages 90 formed in a direction orthogonal to the rotation axis RL. It is formed including.

  The switching mechanism 100 includes a second oil passage 102, a valve body 104, a piston 106, a piston operation hydraulic chamber 108, and a spring portion 110. The switching mechanism 100 is disposed on an oil path between the primary hydraulic chamber 54 and the hydraulic control device 130. In the switching mechanism 100, the primary hydraulic chamber 54 and the hydraulic control device 130 communicate with each other as shown in FIG. 2-1, and the primary hydraulic chamber 54 and the hydraulic control device 130 are disconnected as shown in FIG. Switch to the performed state.

  The second oil path 102 has one end connected to the first oil path 86 and the other end connected to the hydraulic control device 130. Further, the second oil passage 102 and the first oil passage 86 are connected by, for example, a rotary joint so that the second oil passage 102 does not rotate even if the first oil passage 86 rotates. In addition, the second oil passage 102 is formed with a tapered surface 112 in which the oil passage becomes larger as it goes from the first oil passage 86 toward the hydraulic control device 130 in the middle of the oil passage.

  The valve body 104 is a spherical member having a larger diameter than the opening 114 at the end of the tapered surface 112 on the first oil passage 86 side. The piston 106 has a pressure receiving surface 106a and a rod-like portion 106b. The pressure receiving surface 106a is a plate-like member, and is disposed inside a piston operating hydraulic chamber 108 to be described later. One end of the rod-like portion 106 b is fixed to the pressure receiving surface 106 a and the other end is fixed to the valve body 104. The piston operating hydraulic chamber 108 is a box-shaped member, and the pressure receiving surface 106a is arranged inside as described above.

  The piston operating hydraulic chamber 108 has a shape in which the area of the inner space portion parallel to the surface of the pressure receiving surface 106a is substantially the same as the area of the pressure receiving surface 106a. The piston operating hydraulic chamber 108 is connected to the switching mechanism control device 120. From the switching mechanism control device 120, the piston operating hydraulic chamber 108 is a surface of the pressure receiving surface 106a opposite to the valve body 104 side. Then, hydraulic oil is supplied to and discharged from a space 108 a formed by the piston operating hydraulic chamber 108. The hydraulic chamber 108 for operating the piston pushes the pressure receiving surface 106a toward the opening 114 side by supplying hydraulic oil therein. Thus, when the pressure receiving surface 106a is pushed by the piston operating hydraulic chamber 108, the piston 106 is moved and the valve body 104 is moved.

  The spring 110 is, for example, a coil spring, and is arranged between a surface to which the rod-like portion 106b of the pressure receiving surface 106a is fixed and a surface of the piston operating hydraulic chamber 108 facing the surface. The spring 110 pushes the pressure receiving surface 106a away from the opening 114.

  The switching mechanism 100 is configured as described above, and hydraulic fluid is supplied to the piston operating hydraulic chamber 108, the amount of hydraulic fluid inside increases, and the pressure receiving surface 106a is pushed out toward the opening 114 side. Here, when the amount of the hydraulic oil inside the piston operating hydraulic chamber 108 becomes a certain level or more, the pressure receiving surface 106a is moved to the opening 114 side by a certain distance as shown in FIG. The hydraulic oil is confined in the primary hydraulic chamber 54. In other words, the hydraulic oil cannot be supplied into the primary hydraulic chamber 54 or discharged from the primary hydraulic chamber 54, and the amount of hydraulic oil in the primary hydraulic chamber 54 does not change. Become. On the other hand, when the amount of hydraulic oil in the piston operating hydraulic chamber 108 is below a certain level, a space is created between the valve body 104 and the opening 114 as shown in FIG. The hydraulic chamber 54 and the hydraulic control device 130 are in communication with each other. That is, the hydraulic oil can be supplied into the primary hydraulic chamber 54 and the hydraulic oil can be discharged from the primary hydraulic chamber 54. Further, since the pressure receiving surface 106a is pushed away from the opening 114 by the spring 110, the valve element 104 is in a state where the pressure receiving surface 106a is not pushed toward the opening 114 by the piston operating hydraulic chamber 108. Is held at a position farthest from the opening 114 in the moving region.

  The switching mechanism control device 120 is connected to an oil passage for hydraulic oil of the hydraulic control device 130 described later, and is supplied with hydraulic oil from the hydraulic control device 130 and discharges hydraulic oil to the hydraulic control device 130. The switching mechanism control device 120 supplies hydraulic oil to the piston operation hydraulic chamber 108 of the switching mechanism 100, discharges the hydraulic oil from the piston operation hydraulic chamber 108, and controls the position of the valve body 104. As the switching mechanism control device 120, for example, a duty solenoid valve that adjusts the amount of hydraulic oil supplied to the switching mechanism 100 with the duty ratio, that is, adjusts the ratio between the ON and OFF times, can be used.

  The hydraulic control device 130 is a hydraulic control means, controls the supply and discharge of hydraulic oil to and from the primary hydraulic chamber 54 that is one clamping pressure generating hydraulic chamber, and the secondary hydraulic chamber 64 that is the other clamping pressure generating hydraulic chamber. Is used to control the supply and discharge of hydraulic oil. The hydraulic control device 130 also controls the pressure of hydraulic oil supplied to each of the primary hydraulic chamber 54 and the secondary hydraulic chamber 64, that is, the supply pressure. The hydraulic control device 130 also supplies and discharges hydraulic oil to the switching mechanism control device 120 described above. The hydraulic control device 130 also supplies hydraulic oil to a hydraulic oil supply portion that requires supply of hydraulic oil in a vehicle in which the belt type continuously variable transmission 22 and the internal combustion engine 12 are mounted. The hydraulic control device 130 supplies hydraulic oil to the primary hydraulic chamber 54 and discharges the hydraulic oil from the primary hydraulic chamber 54 when the switching mechanism 100 is opened and communicates with the primary hydraulic chamber 54.

  The hydraulic control device 130 supplies hydraulic oil to the primary hydraulic chamber 54, the secondary hydraulic chamber 64, the switching mechanism control device 120, and the like, and controls the hydraulic pressure, the hydraulic oil supply flow rate, and the hydraulic oil discharge flow rate. It also controls the gear ratio γ of the belt type continuously variable transmission 22. In FIG. 3, the hydraulic oil supply portion (excluding the above-described hydraulic oil supply portion and the lubricating portion of the belt-type continuously variable transmission 22 (for example, movable) is excluded from the primary hydraulic chamber 54, the secondary hydraulic chamber 64, and the switching mechanism control device 120. The illustration of a stationary part having a sliding part between the parts, a movable part or a movable part having a sliding part between the parts is omitted. As shown in FIG. 3, the hydraulic control device 130 includes an oil pan 131, an oil pump 132, a line pressure control device 133, a constant pressure control device 134, a primary hydraulic chamber control device 135, and a secondary hydraulic chamber control device. 137.

  The oil pump 132 sucks, pressurizes, and discharges the hydraulic oil stored in the oil pan 131. The oil pump 132 is connected to the line pressure control device 133 via the oil passage R1. The hydraulic oil pressurized and discharged by the oil pump 132 is supplied to the line pressure control device 133. As shown in FIG. 1, the oil pump 132 is disposed between the torque converter 16 and the forward / reverse switching mechanism 20. The oil pump 132 includes a rotor 132a, a hub 132b, and a body 132c. The oil pump 132 is connected to the pump of the torque converter 16 through a cylindrical hub 132b by a rotor 132a. The body 132c is fixed to a casing that supports the belt type continuously variable transmission 22 and the like. The hub 132b is spline-fitted to the hollow shaft of the torque converter 16. Therefore, the oil pump 132 can be driven because the output torque T from the internal combustion engine 12 is transmitted to the rotor 132a via the pump of the torque converter 16. That is, the oil pump 132 increases the amount of discharged hydraulic oil, that is, increases the discharge pressure, as the rotational speed of the internal combustion engine 12 increases.

  The line pressure control device 133 adjusts the pressure of the hydraulic oil supplied from the oil pump 132 at the discharge pressure Pout so as to become a predetermined line pressure PL. Specifically, the line pressure control device 133 adjusts the hydraulic oil supplied from the oil passage R1 at the hydraulic pressure Pout according to the output torque of the internal combustion engine 12 to obtain the hydraulic oil having the line pressure PL. Further, the line pressure control device 133 is connected to a second port 166b of a supply side flow rate control valve 166, which will be described later, of the primary hydraulic chamber control device 135 via an oil passage R2, and via the oil passage R2 and the branch oil passage R21. Are connected to a constant pressure control device 134 and are connected to a secondary hydraulic chamber control device 137 via an oil passage R2 and a branch oil passage R22. Accordingly, the hydraulic oil having the line pressure PL adjusted by the line pressure control device 133 is introduced into the second port 166b of the supply side flow control valve 166, the constant pressure control device 134, and the secondary hydraulic chamber control device 137.

  The line pressure control device 133 includes an electromagnetic valve that adjusts the pressure of the hydraulic oil discharged from the oil pump 132, for example, a linear solenoid valve. The line pressure control device 133 is electrically connected to the ECU 140, and the line pressure PL can be adjusted by controlling the valve opening degree of the linear solenoid valve by a control signal from the ECU 140. In the embodiment, the line pressure control device 133 controls the pressure of hydraulic oil supplied to the primary hydraulic chamber 54 via the primary hydraulic chamber control device 135, that is, the supply pressure, by controlling the line pressure PL. .

  The constant pressure control device 134 adjusts the line pressure PL output from the line pressure control device 133 so as to always become a constant pressure. Specifically, the constant pressure control device 134 adjusts the hydraulic oil at the hydraulic pressure PL supplied from the oil passage R2 and the branch oil passage R21 to obtain the hydraulic oil at the constant pressure PS. The constant pressure control device 134 is connected to a first port 162a of a supply side control valve 162 (described later) of the primary hydraulic chamber control device 135 via an oil passage R3, and is connected to the primary hydraulic pressure via the oil passage R3 and the branch oil passage R31. It connects with the 1st port 164a of the discharge side control valve 164 mentioned later of the control device 135 for rooms. Therefore, the hydraulic oil of constant pressure PS adjusted by the constant pressure control device 134 is introduced into the first port 162a of the supply side control valve 162 and the first port 164a of the discharge side control valve 164.

  The primary hydraulic chamber control device 135 controls the supply of hydraulic oil to the primary hydraulic chamber 54 or the discharge of hydraulic oil from the primary hydraulic chamber 54. In the embodiment, the primary hydraulic chamber control device 135 controls the supply flow rate of the hydraulic oil supplied to the primary hydraulic chamber 54 and the discharge flow rate of the hydraulic oil discharged from the primary hydraulic chamber 54. The primary hydraulic chamber control device 135 includes a supply side control valve 162, a discharge side control valve 164, a supply side flow rate control valve 166, and a discharge side flow rate control valve 168.

  The supply side control valve 162 controls the supply flow rate of the hydraulic oil supplied to the primary hydraulic chamber 54 by the supply side flow rate control valve 166. The supply-side control valve 162 switches communication between three ports, that is, the first port 162a, the second port 162b, and the third port 162c by ON / OFF. The first port 162a is connected to the constant pressure control device 134 as described above. The 2nd port 162b is connected with the 1st port 166a mentioned below of supply side flow control valve 166 via oil way R4. The second port 162b is connected to a later-described fourth port 168d of the discharge-side flow rate control valve 168 via the oil passage R4 and the branch oil passage R41. The third port 162c is connected to the oil pan 131 via the merging oil passage R51 and the oil passage R5. That is, the third port 162c is released to atmospheric pressure.

  When the supply-side control valve 162 is turned on, the first port 162a and the second port 162b are communicated with each other. When the first port 162a and the second port 162b are communicated with each other, the hydraulic oil having a constant pressure PS introduced into the supply side control valve 162 is introduced into the first port 166a of the supply side flow control valve 166. That is, the hydraulic oil having a constant pressure PS introduced into the supply side control valve 162 is introduced into a control hydraulic chamber 166e described later of the supply side flow rate control valve 166 communicating with the first port 166a. Further, the hydraulic oil having a constant pressure PS introduced into the supply side control valve 162 is introduced into the fourth port 168 d of the discharge side flow control valve 168. On the other hand, when the supply-side control valve 162 is turned off, the second port 162b and the third port 162c are communicated with each other. In addition, the first port 166 a of the supply side flow control valve 166 is released to atmospheric pressure via the supply side control valve 162. As a result, the control hydraulic chamber 166e is released to atmospheric pressure via the first port 166a of the supply-side flow rate control valve 166. In addition, the fourth port 168 d of the discharge side flow control valve 168 is released to atmospheric pressure via the supply side control valve 162. As shown in FIG. 3, the supply-side control valve 162 is electrically connected to the ECU 140 and is duty-controlled by a control signal from the ECU 140. Therefore, the supply-side control valve 162 can regulate the control hydraulic chamber 166e of the supply-side flow rate control valve 166 from a constant pressure PS to atmospheric pressure by a control signal from the ECU 140.

  The discharge side control valve 164 performs discharge flow control of the hydraulic oil discharged from the primary hydraulic chamber 54 by the discharge side flow control valve 168. The discharge-side control valve 164 switches communication between three ports, that is, the first port 164a, the second port 164b, and the third port 164c, by ON / OFF. The first port 164a is connected to the constant pressure control device 134 as described above. The second port 164b is connected to a later-described first port 168a of the discharge-side flow rate control valve 168 via the oil path R6. The second port 164b is connected to a later-described fourth port 166d of the supply-side flow rate control valve 166 via the oil passage R6 and the branch oil passage R61. The third port 164c is connected to the oil pan 131 via the oil path R5. That is, the third port 164c is released to atmospheric pressure.

  When the discharge side control valve 164 is turned ON, the first port 164a and the second port 164b are communicated. When the first port 164a and the second port 164b are communicated with each other, the hydraulic oil having a constant pressure PS introduced into the discharge side control valve 164 is introduced into the first port 168a of the discharge side flow control valve 168. That is, the hydraulic oil having a constant pressure PS introduced into the discharge side control valve 164 is introduced into a later-described control hydraulic chamber 168e of the discharge side flow control valve 168 communicating with the first port 168a. Further, the hydraulic oil having a constant pressure PS introduced into the discharge side control valve 164 is introduced into the fourth port 166 d of the supply side flow control valve 166. On the other hand, when the discharge side control valve 164 is turned off, the second port 164b and the third port 164c are communicated. Further, the first port 168 a of the discharge side flow control valve 168 is released to atmospheric pressure via the discharge side control valve 164. As a result, the control hydraulic chamber 168e is released to atmospheric pressure via the first port 168a of the discharge side flow control valve 168. Further, the fourth port 166 d of the supply side flow control valve 166 is released to the atmospheric pressure via the discharge side control valve 164. As shown in FIG. 3, the discharge side control valve 164 is electrically connected to the ECU 140 and is duty-controlled by a control signal from the ECU 140. Therefore, the discharge-side control valve 164 can regulate the control hydraulic chamber 168e of the discharge-side flow control valve 168 from a constant pressure PS to atmospheric pressure by a control signal from the ECU 140.

  The supply-side flow rate control valve 166 controls the supply flow rate of the hydraulic oil supplied to the primary hydraulic chamber 54. The supply-side flow rate control valve 166 includes a first port 166a, a second port 166b, a third port 166c, a fourth port 166d, a control hydraulic chamber 166e, a spool 166f, and a spool elastic member 166g. . The first port 166a is connected to the second port 162b of the supply side control valve 162 as described above. The second port 166b is connected to the line pressure control device 133 as described above. The third port 166c is connected to the primary hydraulic chamber 54 via the oil passage R7. Here, the third port 166c is connected to the primary hydraulic chamber 54 via the oil passage R7, the switching mechanism 100, and the first oil passage 86. The fourth port 166d is connected to the second port 164b of the discharge side control valve 164 as described above. As shown in the figure, the second pressure 162 between the second port 162b of the supply-side control valve 162 and the first port 166a of the supply-side flow control valve 166, the second of the line pressure control device 133 and the supply-side flow control valve 166. Orifices 170a and 170b, that is, throttles are provided between the port 166b and hydraulic oil flowing from the supply-side control valve 162 to the supply-side flow control valve 166, and from the line pressure control device 133 to the supply-side flow control valve 166. The pressure or flow rate of the hydraulic oil may be adjusted.

  The control hydraulic chamber 166e communicates with the first port 166a, and one direction (in FIG. 3, the direction from the first port 166a toward the fourth port 166d) of the spool 166f moves the spool 166f by the hydraulic pressure. Hereinafter, it is also referred to as “first direction”), and the spool valve opening direction pressing force is applied to the spool 166f. The spool 166f is movably supported in the primary hydraulic chamber control device 135, and is moved in the first direction to allow the second port 166b and the third port 166c to communicate with each other. 3 is moved in the direction (in FIG. 3, the direction from the fourth port 166d toward the first port 166a, hereinafter also referred to as “second direction”), the communication between the second port 166b and the third port 166c is established. It is something to shut off. The spool elastic member 166g is arranged in a state of being biased between the spool 166f and a member stationary with respect to the spool 166f. Accordingly, the spool elastic member 166g generates a spool urging force, and applies a spool closing direction pressing force that presses the spool 166f in the second direction by the spool urging force to the spool 166f.

  The supply-side flow rate control valve 166 moves the spool 166f in the first direction when the spool valve opening direction pressing force acting on the spool 166f exceeds the spool valve closing direction pressing force. Here, the supply-side flow rate control valve 166 increases the degree of communication between the second port 166b and the third port 166c, that is, the second port 166b and the third port 166f as the amount of movement of the spool 166f in the first direction increases. The channel cross-sectional area of the channel that communicates with the port 166c increases. In other words, the supply-side flow rate control valve 166 moves the spool 166f by the hydraulic pressure in the control hydraulic chamber 166e regulated by the supply-side control valve 162, so that two ports, that is, the second port 166b and the third port 166c. And the supply flow rate of hydraulic oil to the primary hydraulic chamber 54 is controlled.

  The discharge side flow control valve 168 controls the discharge flow rate of the hydraulic oil discharged from the primary hydraulic chamber 54. The discharge-side flow rate control valve 168 includes a first port 168a, a second port 168b, a third port 168c, a fourth port 168d, a control hydraulic chamber 168e, a spool 168f, and a spool elastic member 168g. The first port 168a is connected to the second port 164b of the discharge side control valve 164 as described above. The second port 168b is connected to the oil pan 131 via the merging oil path R52, the merging oil path R51, and the oil path R5. That is, the second port 168b is released to atmospheric pressure. The third port 168c is connected to the primary hydraulic chamber 54 via the branch oil passage R71 and the oil passage R7. In the embodiment, the third port 168c is connected to the primary hydraulic chamber 54 via the branch oil passage R71, the oil passage R7, the switching mechanism 100, and the first oil passage 86. The fourth port 168d is connected to the second port 162b of the supply side control valve 162 as described above. As shown in the figure, an orifice 170 c, that is, a throttle is provided between the second port 164 b of the discharge side control valve 164 and the first port 168 a of the discharge side flow control valve 168, and the discharge side control valve 164 The pressure or flow rate of the hydraulic oil flowing into the discharge side flow rate control valve 168 may be adjusted.

  The control hydraulic chamber 168e communicates with the first port 168a, and one direction of the direction in which the spool 168f moves the spool 168f by the hydraulic pressure (in FIG. 3, the direction from the first port 168a toward the fourth port 168d). Hereinafter, it is also referred to as a “third direction”), and the spool valve opening direction pressing force is applied to the spool 168f. The spool 168f is movably supported in the primary hydraulic chamber control device 135, and is moved in the third direction to communicate the second port 168b and the third port 168c. 3 (in FIG. 3, the direction from the fourth port 168d toward the first port 168a, hereinafter also referred to as “fourth direction”), the communication between the second port 168b and the third port 168c is established. It is something to shut off. The spool elastic member 168g is arranged in a state of being biased between the spool 168f and a member stationary with respect to the spool 168f. Accordingly, the spool elastic member 168g generates a spool biasing force, and applies a spool closing direction pressing force that presses the spool 168f in the fourth direction by the spool biasing force to the spool 168f.

  The discharge-side flow control valve 168 moves the spool 168f in the third direction when the spool opening direction pressing force acting on the spool 168f exceeds the spool closing direction pressing force. Here, the discharge-side flow rate control valve 168 increases the degree of communication between the second port 168b and the third port 168c as the amount of movement of the spool 168f in the third direction increases, that is, the second port 168b and the third port 168f. The channel cross-sectional area of the channel that communicates with the port 168c increases. In other words, the discharge-side flow rate control valve 168 has two ports, that is, the second port 168b and the third port 168c, as the spool 168f moves by the hydraulic pressure of the control hydraulic chamber 168e regulated by the discharge-side control valve 164. Control the communication with the exhaust flow.

  The secondary hydraulic chamber control device 137 controls the supply of hydraulic oil to the secondary hydraulic chamber 64 or the discharge of hydraulic oil from the secondary hydraulic chamber 64. As described above, the line pressure PL is introduced into the secondary hydraulic chamber control device 137 from the line pressure control device 133. The secondary hydraulic chamber control device 137 is connected to the secondary hydraulic chamber 64 via an oil passage R9. In the embodiment, the secondary hydraulic chamber control device 137 is connected to the secondary hydraulic chamber 64 via an oil passage R9, a hydraulic oil passage (not shown) of the secondary pulley shaft 61, and a hydraulic fluid supply hole (not shown). The secondary hydraulic chamber control device 137 includes a flow rate control valve (not shown). The secondary hydraulic chamber control device 137 is electrically connected to the ECU 140, and regulates the introduced line pressure PL controlled by a control signal from the ECU 140.

  ECU 140 is a control means. The ECU 140 is connected to the switching mechanism control device 120, the hydraulic control device 130, and the internal combustion engine 12, and controls the switching mechanism control device 120, the hydraulic control device 130, and the internal combustion engine 12. Accordingly, the ECU 140 controls the line pressure control device 133, the primary hydraulic chamber control device 135, and the secondary hydraulic chamber control device 137 by the control signal output to the hydraulic control device 130, so that the belt-type continuously variable transmission 22. The gear ratio γ is controlled. For example, the ECU 140 controls the hydraulic control device 130 so that a speed ratio γ based on a detected input speed Nin and a detected output speed Nout, which will be described later, becomes a target speed ratio γo. Here, the gear ratio γ is a value obtained by dividing the input rotational speed by the output rotational speed, that is, γ = Nin / Nout. The ECU 140 also controls the switching mechanism control device 120 to close the hydraulic oil in the primary hydraulic chamber 54 and to supply and discharge the hydraulic oil into the primary hydraulic chamber 54. The hydraulic control mode for controlling the amount of hydraulic oil in 54 is switched. That is, ECU 140 controls switching mechanism control device 120 to control whether or not the position of primary movable sheave 53 is fixed. The ECU 140 controls the output torque T of the internal combustion engine 12 by controlling a fuel injection valve, a spark plug, and a throttle valve (not shown) of the internal combustion engine 12 by a control signal output to the internal combustion engine 12. Note that the basic configuration of the ECU 140 is the same as that of an ECU mounted on a conventional vehicle, and a description thereof will be omitted.

  The input rotation speed sensor 150 detects an input rotation speed Nin that is the rotation speed on the input side of the belt type continuously variable transmission 22. The input rotation speed sensor 150 is connected to the ECU 140, and the detected input rotation speed Nin is output to the ECU 140. The input rotation speed sensor 150 detects, for example, the rotation speed of the primary pulley shaft 51 as the input rotation speed Nin.

  The output rotation speed sensor 152 detects an output rotation speed Nout that is the rotation speed on the output side of the belt type continuously variable transmission 22. The output rotation speed sensor 152 is connected to the ECU 140, and the detected output rotation speed Nout is output to the ECU 140. The output rotation speed sensor 152 detects, for example, the rotation speed of the secondary pulley shaft 61 as the output rotation speed Nout.

  Next, the operation of the belt type continuously variable transmission 22 according to the embodiment will be described. First, general forward and reverse travel of the vehicle will be described. When the driver selects the forward position by the shift position device provided in the vehicle, the ECU 140 controls the forward / reverse switching mechanism 20 with the hydraulic oil supplied from the hydraulic control device 130. Specifically, the forward clutch of the forward / reverse switching mechanism 20 is turned on, the reverse brake is turned off, and the input shaft 18 and the primary pulley shaft 51 are directly connected. Thereby, the output torque T from the internal combustion engine 12 is transmitted to the primary pulley 50, and the primary pulley shaft 51 is rotated in the same direction as the rotation direction of the crankshaft 14 of the internal combustion engine 12. The output torque T from the internal combustion engine 12 is transmitted from the primary pulley 50 to the secondary pulley 60 via the belt 80. When the secondary pulley 60 is rotated, the secondary pulley shaft 61 is rotated.

  The output torque T of the internal combustion engine 12 transmitted to the secondary pulley 60 is transmitted from the secondary pulley shaft 61 of the belt-type continuously variable transmission 22 to the speed reducer 24, from the speed reducer 24 to the drive shaft 32, and the drive shaft 32. Is transmitted to a wheel 34 attached to the end of the wheel. The vehicle 10 moves forward by the wheels 34 rotating with respect to the road surface.

  On the other hand, when the driver selects the reverse drive position by the shift position device provided in the vehicle, the ECU 140 turns off the forward clutch of the forward / reverse switching mechanism 20 using the hydraulic oil supplied from the hydraulic control device 130, and reverse brake. Set to ON. As a result, the primary pulley shaft 51 rotates in the direction opposite to the input shaft 38. As a result, the secondary pulley shaft 61, the speed reduction device 24, the drive shaft 32, and the like of the secondary pulley 60 rotate in the opposite direction to the case where the driver selects the forward movement position, and the vehicle moves backward.

  Here, the ECU 140 includes a map (for example, an optimum fuel consumption curve based on the engine speed and the throttle opening of the throttle valve, etc.) stored in the storage unit of the ECU 140 and various conditions such as the vehicle speed and the accelerator opening of the driver. ) Is set so that the operating state of the internal combustion engine 12 is optimal, and the gear ratio γ of the belt-type continuously variable transmission 22 is set to the target gear ratio via the hydraulic control device 130. Control, feedback control and / or feedforward control are performed so as to be γo. Further, the control of the transmission gear ratio γ of the belt type continuously variable transmission 22 includes a closed control mode in which the transmission gear ratio γ is fixed and a hydraulic control mode in which the transmission gear ratio γ is changed, that is, a gear is changed. The change of the gear ratio γ in the closed control mode and the change of the gear ratio γ in the hydraulic control mode are performed by the switching mechanism control device 120, the line pressure control device 133, the primary hydraulic chamber control device 135, and the secondary hydraulic chamber control device. This is done by controlling 137.

  “Change of gear ratio γ” is first performed when the switching mechanism 100 is opened, that is, when the amount of hydraulic oil in the piston operating hydraulic chamber 108 is below a certain level and the pressure receiving surface 106a of the piston 106 is separated from the opening 114. It is assumed that there is a certain space or more between the valve body 104 and the opening 114. Further, with the switching mechanism 100 opened, the hydraulic oil is supplied from the hydraulic control device 130 to the primary hydraulic chamber 54, or the hydraulic oil from the primary hydraulic chamber 54 to the outside of the primary pulley 50 via the hydraulic control device 130. Is discharged, the primary movable sheave 53 slides in the axial direction of the primary pulley shaft 51, and the interval between the primary fixed sheave 52 and the primary movable sheave 53, that is, the width of the primary groove 80a is adjusted. . As a result, the contact radius of the belt 80 in the primary pulley 50 changes, and the speed ratio γ, which is the ratio between the rotation speed of the primary pulley 50 and the rotation speed of the secondary pulley 60, is controlled steplessly (continuously).

  In the secondary pulley 60, the ECU 140 controls the secondary hydraulic chamber control device 137 to regulate the hydraulic pressure in the secondary hydraulic chamber 64 and sandwich the belt 80 between the secondary fixed sheave 62 and the secondary movable sheave 63. The clamping pressure is adjusted. Thereby, the belt tension of the belt 80 wound between the primary pulley 50 and the secondary pulley 60 is controlled.

  Here, the transmission gear ratio γ is fixed when the ECU 140 determines that it is not necessary to change the transmission gear ratio significantly, such as when the traveling state of the vehicle is stable. The ECU 140 performs gear ratio fixing control when fixing the gear ratio γ.

  “Fixing the transmission ratio γ” means that the switching mechanism 100 is closed, that is, the opening 114 is closed by the valve body 104, the working oil is confined in the primary hydraulic chamber 54, and the operating oil is not supplied to the primary hydraulic chamber 54. Further, by not discharging the hydraulic oil from the primary hydraulic chamber 54, the position of the primary movable sheave 53 in the axial direction with respect to the primary fixed sheave 52 is made constant, and the movement of the primary movable sheave 53 with respect to the primary fixed sheave 52 is restricted. Do.

  In the gear ratio fixed control in the closing control mode by the ECU 140, a closing process execution command is input from the ECU 140 to the switching mechanism control device 120. The switching mechanism control device 120 to which the closing process execution command is input closes the switching mechanism 100, supplies hydraulic oil to the primary hydraulic chamber 54 via the switching mechanism 100, and the primary hydraulic chamber via the switching mechanism 100. The discharge of hydraulic oil from 54 is prohibited. Thus, by fixing the position of the primary pulley 50, the speed ratio γ is maintained at the set target speed ratio γo.

  In this way, the hydraulic control device 130 is closed by the switching mechanism 100, traps the hydraulic oil in the primary hydraulic chamber 54, and fixes the gear ratio γ, thereby supplying the hydraulic oil to the primary hydraulic chamber 54 after the valve is closed. Can be reduced from the pressure at the time of supplying hydraulic oil to the primary hydraulic chamber 54. Thereby, the energy used for the oil pump 132 to supply to the primary hydraulic chamber 54, specifically, the energy used for boosting the hydraulic oil can be reduced. Thereby, the energy which must be generated in the internal combustion engine 12 can be reduced, and fuel consumption can be improved.

  Here, in the switching mechanism 100, the piston, the valve body, etc. are stuck in the open state (hereinafter also referred to as “OFF sticking”), and the valve body does not move even in the closed control mode, and the switching mechanism There was a problem that 100 could not close the valve. If the switching mechanism 100 cannot close the valve, it is necessary to always control the amount of hydraulic oil supplied to the primary hydraulic chamber 54 by the oil pump 132 even during stable running, so the friction of the internal combustion engine 12 cannot be reduced. Fuel economy cannot be improved. Hereinafter, the return process of the switching mechanism 100 when the switching mechanism 100 cannot be closed and the gear ratio fixed control cannot be performed will be described. FIG. 4 is a flowchart showing the operation of the return process of the switching mechanism 100.

  First, as step ST10, the switching mechanism control device 120 detects whether or not an execution command for the closing process is input from the ECU 140. When the switching mechanism control device 120 confirms in step ST10 that the execution command for the closing process has been input, that is, it is in the closing control mode, the switching mechanism control apparatus 120 performs the closing process, and proceeds to step ST12. If it is confirmed in step ST10 that an instruction to execute the closing process has not been input, the process ends. Here, the closing process is a control for closing the switching mechanism 100 described above.

  Next, when the closing process is executed by the switching mechanism 100, as step ST12, the ECU 140 determines whether or not the gear ratio is fixed. Here, the detection method of the gear ratio is not particularly limited. For example, it may be detected from the ratio between the input rotation speed Nin detected by the input rotation speed sensor 150 and the output rotation speed Nout detected by the output rotation speed sensor 152. . Whether or not the gear ratio is fixed is determined if the gear ratio change width within a certain time is equal to or smaller than a certain value, and the gear ratio is determined to be fixed. It is determined that the gear ratio is not fixed. If the ECU 140 determines in step ST12 that the gear ratio is fixed, the process is terminated assuming that the switching mechanism 100 is operating normally. If the ECU 140 determines in step ST12 that the gear ratio is not fixed, the process proceeds to step ST14 assuming that the switching mechanism 100 is not operating normally and the switching mechanism 100 is not closed.

  ECU 140 prohibits the closing process as step ST14. That is, the ECU 140 is set so that the closing control mode for closing the switching mechanism 100 cannot be selected, and the oil pump 132 and the primary hydraulic chamber 54 are connected in the hydraulic control mode even when the traveling state of the vehicle is stable. The amount of hydraulic oil in the primary hydraulic chamber 54 is adjusted in the communicated state.

  In this way, if the closing process is prohibited, the ECU 140 determines whether the vehicle is in a steady running state as step ST16. That is, the ECU 140 is a driving state in which the change range of the target gear ratio within a certain time is equal to or less than a threshold value, for example, a stable traveling state in which the switching mechanism 100 can perform the closing process in the normal processing mode. Determine whether. When the ECU 140 determines in step ST16 that the vehicle is not in a steady running state, the process proceeds to step ST16 again, and the determination of whether or not the vehicle is in a steady running state is repeated. If it is determined in step ST16 that the ECU 140 is in a steady running state, the process proceeds to step ST18.

  ECU 140 performs a return process of switching mechanism 100 as step ST18. The returning process of the switching mechanism 100 is a process of returning the switching mechanism 100 that cannot be closed and is closed when the valve body 104, the piston 106, etc. are in the OFF position, that is, in the opened state. Specifically, the ECU 140 supplies the maximum amount of hydraulic fluid to the piston operating hydraulic chamber 108 from the ECU 140 to the switching mechanism control device 120. For example, when a duty solenoid is used in the switching mechanism control device 120, the piston 106 and the valve body 104 are pushed out toward the opening 114 with the duty ratio being maximized and the amount of hydraulic oil supplied to the piston operating hydraulic chamber 108 being maximized. .

  Next, when the return process of the switching mechanism 100 is performed in step ST18, the ECU 140 determines in step ST20 whether the gear ratio was fixed during the return process. If the ECU 140 determines in step ST20 that the gear ratio has not been fixed during the return process, it is determined that the switching mechanism 100 has not returned to the normal state, that is, is in the OFF-fixed state, and the process proceeds to step ST16. . Thus, ECU140 repeats step ST16 and step ST18 until the switching mechanism 100 returns to a normal state. On the other hand, if ECU 140 determines in step ST20 that the gear ratio has been fixed during the return process, it determines that switching mechanism 100 has returned to a normal state, and proceeds to step ST22. In step ST22, ECU 140 cancels the prohibition of the closing process, that is, returns to the normal processing state, and ends the process.

  In this way, it is detected whether the closing process is being executed, and when the switching mechanism 100 is fixed to OFF and the closing process cannot be executed, the returning process of the switching mechanism 100 is performed while prohibiting the closing process. As a result, the closing process can be executed again. Since it becomes possible to perform the closing process again, the energy used by the oil pump 132 can be reduced, and fuel consumption can be improved.

  Further, by performing the return process of the switching mechanism in the steady running state, even if the switching mechanism 100 returns and the hydraulic oil in the primary hydraulic chamber 54 is trapped, the burden on other parts of the vehicle can be reduced. it can. That is, by selecting the time when the change in the gear ratio is small and performing the return process, the operation for maintaining the gear ratio, speed, acceleration, etc. is reduced even when the switching mechanism 100 is in the valve-closed state. Therefore, the burden on various parts of the vehicle can be reduced. Specifically, if the switching mechanism 100 is closed during the speed change operation of the belt type continuously variable transmission 22, the speed ratio is fixed during the speed change, which may cause a shock to the vehicle 10. The possibility of giving such a shock can be reduced by performing the return operation in the steady running state. Further, by detecting whether the transmission gear ratio is fixed in the steady running state, it is possible to reliably determine whether or not the switching mechanism has returned, and for the return processing, the switching mechanism 100 and the switching mechanism control are determined. The energy used in the device 120 can be reduced.

  If the gear ratio is not fixed even if the switching mechanism return processing is repeated a certain number of times, that is, if the switching mechanism is not closed, the operator is notified that a malfunction has occurred in the switching mechanism. May be.

  In the above embodiment, the switching mechanism is a mechanism that traps the hydraulic oil in the primary hydraulic chamber by closing the opening with a valve body that is moved by a piston. Various mechanisms can be used as long as the mechanism can contain oil. For example, the oil passage may be blocked with a plate-like member. Further, the switching mechanism may be provided coaxially with the primary pulley shaft. In this embodiment, the oil passage for supplying the hydraulic oil to the primary hydraulic chamber and the oil passage for discharging the hydraulic oil from the primary hydraulic chamber are the same oil passage. However, the oil passage to be supplied and the oil passage to be discharged are used. And separate oil passages. As described above, when separate oil passages are used, a check valve may be used for each oil passage, and a mechanism capable of closing operation may be provided in the oil passage on the discharge side.

  As described above, the belt-type continuously variable transmission according to the present invention is useful for a belt-type continuously variable transmission that holds hydraulic oil in a clamping pressure generating hydraulic chamber by closing the hydraulic oil supply / discharge valve. In particular, it is suitable for improving at least one of speed change response and speed ratio controllability.

It is a conceptual diagram which shows the whole structure in the power transmission part of the vehicle provided with the belt-type continuously variable transmission which concerns on this embodiment. It is a conceptual diagram which expands and shows schematic structure of the belt-type continuously variable transmission shown in FIG. It is a conceptual diagram which expands and shows schematic structure of the belt-type continuously variable transmission shown in FIG. It is a conceptual diagram which shows typically schematic structure of a hydraulic control apparatus. It is a flowchart which shows the operation | movement of the return process of a switching mechanism.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Vehicle 12 Internal combustion engine 22 Belt type continuously variable transmission 50 Primary pulley 52 Primary fixed sheave 53 Primary movable sheave 60 Secondary pulley 100 Switching mechanism 120 Switching mechanism control device

Claims (3)

A fixed sheave and a movable sheave that moves relative to the fixed sheave, two pulleys that can adjust a distance between the fixed sheave and the movable sheave, and a pulley that is hung between the two pulleys to rotate one pulley. A belt-type continuously variable transmission that has a belt that transmits to the belt and that changes the gear ratio by relatively changing the diameters of the two pulleys.
A pulley shaft connected to the power generating means and rotating together with the power generating means;
A fixed sheave coupled to the pulley shaft;
A movable sheave coupled to a position of the pulley shaft facing the fixed sheave and movable in the axial direction of the pulley shaft;
A hydraulic chamber that is provided on the pulley shaft and applies an axial force of the movable sheave to the movable sheave by hydraulic oil injected therein;
Hydraulic oil supply and discharge means that communicates with the hydraulic chamber, supplies the hydraulic oil to the hydraulic chamber, and discharges the hydraulic oil from the hydraulic chamber;
A state in which the hydraulic fluid is disposed between the hydraulic chamber and the hydraulic oil supply / discharge means, and the hydraulic oil can flow between the hydraulic oil supply / discharge means and the hydraulic chamber, A switching mechanism for switching between the state where
The switching mechanism prohibits the flow of the hydraulic oil between the hydraulic oil supply / discharge means and the hydraulic chamber, and confines the hydraulic pressure of the hydraulic chamber inside, and the hydraulic fluid is supplied by the switching mechanism. A hydraulic control mode is provided in which the hydraulic oil is allowed to flow between the discharge means and the hydraulic chamber, and the hydraulic pressure is adjusted in the hydraulic chamber by the hydraulic oil supply / discharge means, and the input gear ratio is obtained. Hydraulic control means for controlling the operation of the hydraulic oil supply and discharge means and the switching mechanism to adjust the amount of the hydraulic oil in the hydraulic chamber,
When the hydraulic pressure control unit detects that the gear ratio is not fixed during the closing control mode, the hydraulic control unit prohibits the use of the closing control mode, switches to the hydraulic control mode, and switches the gear ratio in the hydraulic control mode. When the speed change ratio becomes constant during the hydraulic control mode, the closing control mode can be used.
The return process of the switching mechanism is a process of pushing out the switching mechanism so that the switching mechanism prohibits the flow of the hydraulic oil between the hydraulic oil supply / discharge means and the hydraulic chamber. Belt type continuously variable transmission. The switching mechanism is a valve driven by a duty solenoid,
The belt-type continuously variable transmission according to claim 1, wherein the return process of the switching mechanism pushes the valve by increasing a duty ratio of a duty solenoid.   3. The belt-type continuously variable transmission according to claim 1, wherein the return process of the switching mechanism is performed only while the change width of the target gear ratio within a predetermined time is within a threshold value. 4.

Images