JP2010048365A - Belt-type continuously variable transmission - Google Patents

Abstract

A belt-type continuously variable transmission capable of suppressing the occurrence of belt slip is provided.
There are two pulleys whose diameters change depending on the amount of hydraulic oil in a hydraulic chamber, and a belt that is hung between the two pulleys and transmits the rotation of one pulley to the other pulley. A belt type continuously variable transmission that changes the gear ratio by relatively changing the diameters of two pulleys, and the switching mechanism control means is disconnected during a closed control mode in which hydraulic oil is confined in a hydraulic chamber. Is detected, the hydraulic oil is supplied from the hydraulic oil supply / discharge means to the second hydraulic chamber, and then the hydraulic oil is supplied from the hydraulic oil supply / discharge means to the first hydraulic chamber, and the first hydraulic chamber and the second hydraulic chamber are supplied. The above-mentioned problem is solved by adjusting the hydraulic pressure.
[Selection] Figure 1

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.

  Japanese Patent Laid-Open No. 2004-228561 controls whether or not hydraulic oil is discharged from the positioning hydraulic chamber. The hydraulic oil discharge valve rotates integrally with the pulley, and the hydraulic oil is discharged from the hydraulic chamber by the hydraulic oil discharge valve. A discharge flow rate control valve that controls the oil discharge flow rate, and the discharge flow rate control valve is disposed at a position where the hydraulic pressure in the hydraulic chamber does not act in the direction of the on-off valve when the hydraulic oil discharge valve is opened. A continuously variable transmission is described.

JP 2006-300270 A JP 2008-101751 A

  As in the device described in Patent Document 1, by providing a discharge-side control valve that inhibits hydraulic oil from being discharged from the hydraulic chamber, that is, a switching mechanism, the oil pump is operated when the speed ratio is fixed. Since it is not necessary to control the hydraulic chamber so as to be maintained constant, the power loss of the oil pump can be reduced, and the gear ratio can be more reliably fixed. Further, as described in Patent Document 2, by controlling the flow rate of the hydraulic oil discharged from the hydraulic chamber by a discharge flow rate control valve disposed at a position where the hydraulic pressure of the hydraulic chamber does not act in the on-off valve direction, The controllability of the discharge flow rate can be improved.

  Here, Patent Document 1 and Patent Document 2 can obtain the advantageous effects as described above. However, in order to improve energy efficiency, when the transmission gear ratio is fixed, the oil pump supplies the hydraulic chamber. Since the hydraulic pressure of the hydraulic fluid is lowered, there is a problem that if the hydraulic pressure in the hydraulic chamber decreases when the transmission gear ratio is fixed, the movable sheave moves and belt slip occurs. Belt slip is a problem because it may reduce the durability of the belt or pulley.

  The present invention has been made in view of the above, and an object of the present invention is to provide a belt-type continuously variable transmission that can suppress the occurrence of belt slip.

  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 first pulley shaft connected to the power generating means and rotating together with the power generating means; a first fixed sheave connected to the first pulley shaft; and facing the first fixed sheave of the first pulley shaft. And a first movable sheave that is movable in the axial direction of the first pulley shaft, and is provided on the first pulley shaft and is hydraulically injected into the first movable sheave to the first movable sheave. First pooh A first pulley having a first hydraulic chamber for applying an axial force of the shaft, a second pulley shaft arranged in parallel with the first pulley shaft, a second fixed sheave connected to the second pulley shaft, A second movable sheave connected to a position of the second pulley shaft facing the second fixed sheave and movable in the axial direction of the second pulley shaft, and provided on the second pulley shaft, A second pulley provided with a second hydraulic chamber for applying an axial force of the second pulley shaft to the second movable sheave by the injected hydraulic oil, and between the first pulley and the second pulley. A belt for transmitting the rotation of the first pulley to the second pulley; supplying the hydraulic oil to the first hydraulic chamber; and discharging the hydraulic oil from the first hydraulic chamber; Supplying the hydraulic oil to a second hydraulic chamber, and the second hydraulic chamber The hydraulic oil supply / discharge means for discharging the hydraulic oil, and the hydraulic oil flow path between the first hydraulic chamber and the hydraulic oil supply / discharge means, and the hydraulic oil supply / discharge means and the first hydraulic oil supply / discharge means. A switching mechanism that switches between a state in which the hydraulic oil can flow between the hydraulic chamber and a state in which the hydraulic fluid is prohibited; a switching mechanism control unit that controls the operation of the switching mechanism; and the operation by the switching mechanism. A closed control mode for prohibiting the flow of the hydraulic oil between the oil supply / discharge means and the first hydraulic chamber and confining the hydraulic pressure of the first hydraulic chamber inside, and the hydraulic oil supply / discharge means by the switching mechanism Between the first hydraulic chamber and the first hydraulic chamber so that the hydraulic fluid can flow and the hydraulic fluid supply mode for adjusting the hydraulic pressure in the first hydraulic chamber by the hydraulic oil supply / discharge means is selected and input. So that the gear ratio is Hydraulic pressure control means for adjusting the amount of the hydraulic oil in the first hydraulic pressure chamber by controlling the operation of the hydraulic oil supply / discharge means and the switching mechanism, and the hydraulic pressure control means is in the closed control mode. When it is detected that the switching mechanism control means is disconnected, the hydraulic oil is supplied from the hydraulic oil supply / discharge means to the second hydraulic chamber, and then the hydraulic oil supply / discharge means is operated to the first hydraulic chamber. Oil is supplied to adjust the hydraulic pressure in the first hydraulic chamber and the second hydraulic chamber.

  The belt-type continuously variable transmission according to the present invention can suppress the occurrence of belt slip, can be made less likely to fail, and has the effect of extending the life of the device.

  Hereinafter, the present invention will be described in detail with reference to the drawings. The present invention is not limited to the best mode for carrying out the invention (hereinafter referred to as “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 a 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 element 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 the 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 communicated with the primary pulley 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, which will be described later, of the supply-side flow 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, that is, the second port 168b and the third port 168f as the amount of movement of the spool 168f in the third direction increases. 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.

  The ECU 140 is a control unit, and includes a storage unit 142, a hydraulic pressure control unit 144, an input rotation speed sensor 150, and an output rotation speed sensor 152. The ECU 140 is connected to the switching mechanism control device 120, the hydraulic control device 130, and the internal combustion engine 12. The storage means 142 stores a map for determining the operation parameters of each part in accordance with various conditions such as the speed of the vehicle and the accelerator opening of the driver, for example, optimum fuel consumption based on the engine speed and the throttle opening of the throttle valve. Curves are stored.

  The hydraulic control unit 144 controls the switching mechanism control device 120, the hydraulic control device 130, and the internal combustion engine 12 based on the operating conditions and various data stored in the storage unit 142. Specifically, the hydraulic pressure control unit 144 is configured to select the line pressure control device 133, the primary hydraulic chamber based on the current transmission ratio, the operation conditions such as the target transmission ratio, and various data stored in the storage unit 142. Control signals for the control device 135 and the secondary hydraulic chamber control device 137 are generated and output to the hydraulic control device 130. In this way, the hydraulic control means 144 controls the line pressure control device 133, the primary hydraulic chamber control device 135, and the secondary hydraulic chamber control device 137 according to the control signal output to the hydraulic control device 130, which will be described later. The hydraulic control device 130 is controlled so that the speed ratio γ based on the detected input speed Nin and the detected output speed Nout becomes the 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 hydraulic control means 144 controls the switching mechanism control device 120 to confine the hydraulic oil in the primary hydraulic chamber 54, supply and discharge hydraulic oil into the primary hydraulic chamber 54, and supply the primary hydraulic pressure. The hydraulic control mode for controlling the amount of hydraulic oil in the chamber 54 is switched. That is, the hydraulic control means 144 controls the switching mechanism control device 120 to control whether or not the position of the primary movable sheave 53 is fixed. Further, 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 hydraulic control means 144 of the ECU 140 has an optimum operating state of the internal combustion engine 12 based on various conditions such as the speed of the vehicle and the accelerator opening of the driver and a map stored in the storage means 142 of the ECU 140. The target gear ratio γo is set so that Next, the hydraulic control means 144 is configured to supply the hydraulic oil flowing between the hydraulic control device 130 and the primary hydraulic chamber 54 stored in the storage means 142 and the current state of the primary hydraulic chamber 54 and the secondary hydraulic chamber 64. From the relationship between the amount and the hydraulic pressure in the primary hydraulic chamber 54, the hydraulic pressures in the primary hydraulic chamber 54 and the secondary hydraulic chamber 64 in which the gear ratio γ of the belt type continuously variable transmission 22 becomes the target gear ratio γo are calculated. Further, from the calculated hydraulic pressure, the amount of hydraulic oil supplied from the hydraulic control device 130 to the primary hydraulic chamber 54 and the secondary hydraulic chamber 64, or the hydraulic oil discharged from the primary hydraulic chamber 54 and the secondary hydraulic chamber 64 to the hydraulic control device 130. The hydraulic control device 130 is controlled based on the calculation result. In addition, the control of the transmission gear ratio γ of the belt-type continuously variable transmission 22 by the hydraulic control means 144 includes a closed control mode for fixing the transmission gear ratio γ and a hydraulic control mode for changing the transmission gear ratio γ, that is, a gear shifting mode. The hydraulic control means 144 controls the gear ratio while switching between the closing control mode and the hydraulic control mode on the basis of the operating state and control conditions.

  “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 hydraulic pressure control means 144 controls the secondary hydraulic chamber control device 137 to regulate the hydraulic pressure in the secondary hydraulic chamber 64, and the belt 80 is moved by the secondary fixed sheave 62 and the secondary movable sheave 63. The belt clamping pressure to be clamped 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 gear ratio is fixed when the hydraulic pressure control means 144 determines that it is not necessary to change the gear ratio significantly, such as when the running state of the vehicle is stable. The hydraulic pressure control unit 144 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 hydraulic control unit 144, a closing process execution command is input from the hydraulic control unit 144 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, as described above, when the hydraulic fluid is not supplied from the switching mechanism control device 120, the switching mechanism 100 is moved in a direction in which the valve body 104 is separated from the opening 114 by the force of the spring 110. Therefore, when the valve body 104 is closing the opening 114 in the closed control mode, the switching mechanism control device 120 is disconnected. For example, when the duty solenoid constituting the switching mechanism control device 120 is disconnected, The force that presses the valve body 104 against the opening 114 is lost, the valve body 104 moves away from the opening 114, the primary hydraulic chamber 54 and the hydraulic control device 130 are in communication, and the hydraulic pressure in the primary hydraulic chamber 54 is reduced. Will be reduced. When the hydraulic pressure is reduced in this way, the clamping pressure of the belt 80 by the primary pulley 50 is reduced, and there is a possibility that belt slip occurs. The operation of the hydraulic control means 140 when the switching mechanism control device 120 is disconnected will be described below. FIG. 4 is a flowchart showing an example of a control method by the hydraulic control means 144.

  First, the hydraulic pressure control means 144 determines whether or not the closing process is being executed as step ST10. That is, in the closing control mode, it is determined whether or not a process of closing the opening 114 with the valve body 104 by supplying hydraulic oil from the switching mechanism control device 120 to the switching mechanism 100 is determined. If it is determined in step ST10 that the closing process is being performed, the hydraulic control unit 144 proceeds to step ST12, and if it is determined that the closing process is not being performed, the process is terminated. Next, the hydraulic control means 144 determines whether the switching mechanism control apparatus 120 is disconnected as step ST12. If it is determined in step ST12 that the switching mechanism control device 120 is disconnected, the hydraulic control means 144 proceeds to step ST14. If it is determined that the switching mechanism control device 120 is not disconnected, the process is terminated and the confinement process is continued. Here, whether or not the switching mechanism control device 120 is disconnected may be detected electrically by transmitting a signal. Alternatively, it may be detected whether the speed 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. .

  Next, when it is determined that the switching mechanism control device 120 is disconnected, the hydraulic control means 144 supplies hydraulic oil from the hydraulic control device 130 to the secondary hydraulic chamber 64 as step ST14, and the hydraulic pressure in the secondary hydraulic chamber 64 is determined. To raise. In the secondary pulley 60, when the hydraulic pressure in the secondary hydraulic chamber 64 is increased, the secondary movable sheave 63 moves to the secondary fixed sheave 62 side, the distance between the secondary movable sheave 63 and the secondary fixed sheave 62 decreases, and the belt 80 The contact radius increases. As described above, by increasing the contact radius of the secondary pulley 60 with the belt 80, even if the hydraulic pressure of the primary hydraulic chamber 54 of the primary pulley 50 decreases and the contact radius of the primary pulley 50 with the belt 80 decreases, The belt 80 can be held with a certain tension or more, and the occurrence of belt slip can be suppressed. When the hydraulic pressure control means 144 increases the hydraulic pressure in the secondary hydraulic chamber 64 in step ST14, the hydraulic pressure control means 144 proceeds to step ST16.

  Next, as step ST16, the hydraulic control means 144 supplies hydraulic oil from the hydraulic control device 130 to the primary hydraulic chamber 54, increases the hydraulic pressure in the primary hydraulic chamber 54, and prohibits shifting. Specifically, hydraulic oil is supplied from the hydraulic control device 130 to the primary hydraulic chamber 54 in order to obtain a gear ratio in the closed control mode. In step ST16, even if a control signal for setting a different gear ratio is input during operation, the gear ratio is not changed. When the hydraulic pressure control means 144 increases the hydraulic pressure in the primary hydraulic chamber 54 in step ST16, the hydraulic pressure control means 144 proceeds to step ST18. In step ST18, the hydraulic control unit 144 determines whether the hydraulic pressure in the primary hydraulic chamber 54 is an appropriate hydraulic pressure. Here, the appropriate hydraulic pressure is a hydraulic pressure at which the contact radius of the primary pulley 50 with the belt 80 is the same position as in the closing process. That is, the hydraulic pressure in the primary hydraulic chamber 54 is the same as that in the closing process.

  If it is determined in step ST18 that the hydraulic pressure in the primary hydraulic chamber 54 is appropriate, the hydraulic pressure control means 144 proceeds to step ST20, and if it is determined that the hydraulic pressure in the primary hydraulic chamber 54 is not appropriate, that is, the hydraulic pressure is low, step ST16 is performed. Proceed to, and further increase the hydraulic pressure in the primary hydraulic chamber. Next, as step ST20, the hydraulic control means 144 cancels the prohibition of shifting, disables the closing control mode, and proceeds to step ST22. In other words, the hydraulic control means 144 controls the operation of the hydraulic control device 130 so that an appropriate gear ratio is obtained based on the driving situation only in the hydraulic control mode. In addition, the hydraulic control means 144 is in a state in which the hydraulic ratio is controlled by supplying and discharging hydraulic oil from the hydraulic control device 130 to each hydraulic chamber in the hydraulic control mode even if the conditions for switching to the closed control mode are met. And

  Thereafter, the hydraulic pressure control unit 144 determines whether the switching mechanism control device 120 is energized as step ST22. The hydraulic control means 144 repeats step ST22 until energization is confirmed, and proceeds to step ST24 when energization is confirmed. Note that the hydraulic control means 144 controls the gear ratio under the conditions set in step ST20 until energization is confirmed. Further, the switching mechanism control device 120 that is disconnected is energized by repair, replacement, or the like. When the hydraulic control means 144 confirms that the switching mechanism control device 120 is energized in step ST22, the hydraulic control means 144 cancels the prohibition of the confinement control mode in step ST24 and ends the process. In other words, the hydraulic control unit 144 ends the process after making it possible to switch between the closing control mode and the hydraulic control mode.

  In this way, it is detected whether the switching mechanism control device 120 that controls the operation of the switching mechanism 100 is disconnected by supplying hydraulic oil to the switching mechanism 100 and discharging the hydraulic oil from the switching mechanism 100. Thus, it is possible to detect whether the closing process is properly executed. Further, when the switching mechanism control device 120 is disconnected, the hydraulic pressure in the secondary hydraulic chamber 64 is increased first, so that the hydraulic pressure can be increased in a shorter time and the occurrence of belt slip can be more reliably suppressed. can do. Specifically, in the closed control mode, since the hydraulic oil is confined in the primary hydraulic chamber 54 and the output of the oil pump 132 is reduced, in order to supply the hydraulic oil to the primary hydraulic chamber 54, The oil pump 132 requires time to increase the pressure. On the other hand, since the hydraulic oil is supplied from the oil pump 132 to the secondary hydraulic chamber 64, more hydraulic oil can be supplied to the secondary hydraulic chamber 64 in a shorter time. Can be boosted. Since the secondary hydraulic chamber 64 can be boosted in a short time, tension can be applied to the belt 80 to prevent belt slippage. As described above, the belt slip can be suppressed, the belt can be prevented from being broken or the pulley can be worn, the life of the belt type continuously variable transmission can be extended, and the durability is lowered. Can be suppressed.

  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.

  In the above embodiment, the case has been described where the duty solenoid of the switching mechanism control device is disconnected. However, it is impossible to operate the switching mechanism, specifically, to apply a force to the valve body, and the opening and closing operation of the valve body is prevented. It can also be used for other causes that are not possible.

  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 an example of the control method by the hydraulic control means.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Vehicle 22 Belt type continuously variable transmission 50 Primary pulley 52 Primary fixed sheave 53 Primary movable sheave 60 Secondary pulley 100 Switching mechanism 140 ECU
142 Storage Unit 144 Hydraulic Control Unit

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 first pulley shaft connected to the power generating means and rotating together with the power generating means, a first fixed sheave connected to the first pulley shaft, and a position facing the first fixed sheave of the first pulley shaft The first movable sheave that is movable in the axial direction of the first pulley shaft, and the first pulley shaft that is provided in the first pulley shaft and is moved to the first movable sheave by the hydraulic oil injected therein. A first pulley provided with a first hydraulic chamber for applying an axial force of
A second pulley shaft arranged in parallel with the first pulley shaft, a second fixed sheave connected to the second pulley shaft, and a second pulley shaft connected to a position facing the second fixed sheave of the second pulley shaft; A second movable sheave movable in the axial direction of the second pulley shaft, and an axial direction of the second pulley shaft provided in the second pulley shaft to the second movable sheave by hydraulic oil injected therein A second pulley provided with a second hydraulic chamber for applying a force of
A belt that is hung between the first pulley and the second pulley and transmits the rotation of the first pulley to the second pulley;
The hydraulic oil is supplied to the first hydraulic chamber, the hydraulic oil is discharged from the first hydraulic chamber, the hydraulic oil is supplied to the second hydraulic chamber, and the second hydraulic chamber Hydraulic oil supply / discharge means for discharging the hydraulic oil from
The hydraulic oil is disposed between the first hydraulic chamber and the hydraulic oil supply / discharge means, and the hydraulic oil can flow between the hydraulic oil supply / discharge means and the first hydraulic chamber. A switching mechanism for switching between a state and a state where distribution is prohibited;
Switching mechanism control means for controlling the operation of the switching mechanism;
The switching mechanism prohibits the flow of the hydraulic oil between the hydraulic oil supply / discharge means and the first hydraulic chamber and confines the hydraulic pressure of the first hydraulic chamber inside, and the switching mechanism Either of the hydraulic control modes in which the hydraulic oil is allowed to flow between the hydraulic oil supply / discharge means and the first hydraulic chamber, and the hydraulic pressure in the first hydraulic chamber is adjusted by the hydraulic oil supply / discharge means. Hydraulic control means for controlling the operation of the hydraulic oil supply / discharge means and the switching mechanism to adjust the amount of the hydraulic oil in the first hydraulic chamber so that the input gear ratio is selected. And
When the hydraulic control means detects that the switching mechanism control means is disconnected during the closing control mode, the hydraulic control means supplies hydraulic oil to the second hydraulic chamber from the hydraulic oil supply / discharge means, and then the operation A belt-type continuously variable transmission, wherein hydraulic oil is supplied from an oil supply / discharge means to the first hydraulic chamber to adjust the hydraulic pressure in the first hydraulic chamber and the second hydraulic chamber.   2. The switching mechanism according to claim 1, wherein, in an uncontrolled state, the flow path allows the hydraulic oil to flow between the hydraulic oil supply / discharge means and the first hydraulic chamber. The belt-type continuously variable transmission according to 1.   The hydraulic pressure control means detects the disconnection of the switching mechanism control means during the closed control mode and then completes adjustment of the hydraulic pressures of the first hydraulic chamber and the second hydraulic chamber. The belt-type continuously variable transmission according to claim 1 or 2, wherein the gear ratio is not changed.

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