JP2010230095A - Continuously variable transmission for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a continuously variable transmission for a vehicle which detects a slip of a clutch or the like without requiring a turbine rotation frequency detection sensor, and reduces the number of components and cost. <P>SOLUTION: The continuously variable transmission for the vehicle includes: a belt type continuously variable transmission 8; a forward-reverse switching mechanism 4; a switching valve 64 for supplying a transient oil pressure or a hold oil pressure to the forward-reverse switching mechanism 4 by switching into a transient position D or a hold position E under a spring energization force and a counter pressure thereagainst, along with the controls of a plurality of signal pressures; a belt holding pressure control valve 69 for supplying an oil pressure to a driven side oil chamber 22 by using the spring energization force, the counter pressure, and these signal pressures; an oil pressure sensor 26 for detecting the oil pressure of the driven side oil chamber 22; and a transient oil pressure control valve SLS which supplies a transient oil pressure to the switching valve 64, and increases the transient oil pressure up to a predetermined oil pressure when the detection value of the oil pressure sensor 26 is higher than a predetermined value. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a continuously variable transmission for a vehicle, and more particularly to prevention of slippage of a clutch or brake of a forward / reverse switching mechanism.

  By switching the garage shift valve between the transient position and the holding position by the signal pressure from the solenoid valve, a transient hydraulic pressure that gradually increases during the garage shift is supplied to the forward / reverse switching mechanism during subsequent steady running. A vehicular continuously variable transmission configured as described above has been proposed. In this type of continuously variable transmission, in order to prevent slippage of the clutch when the transient hydraulic pressure is supplied from the garage shift valve due to an abnormality of the electromagnetic valve during the steady running, slippage is prevented. When it is detected, there has been proposed one that increases the transient oil pressure (see Patent Document 1).

JP2007-162731

  In the conventional device, as a clutch slip detection method, a method of detecting the difference between the engine speed and the turbine speed is adopted, so that a turbine speed detection sensor is required in addition to the engine speed detection sensor. There is a problem that the number of points increases and the cost increases.

  The present invention provides a continuously variable transmission for a vehicle that can detect slipping of a clutch or a brake (hereinafter referred to as a clutch or the like) of the forward / reverse switching mechanism without requiring a turbine rotational speed detection sensor, and can reduce the number of parts and cost. The issue is to provide.

The present invention relates to a belt type continuously variable transmission in which a driving pulley having a driving side oil chamber and a driven pulley having a driven side oil chamber are connected by a belt, and the engine rotation is switched between a forward direction and a reverse direction by hydraulic pressure. A forward / reverse switching mechanism that transmits to the continuously variable transmission;
By switching to a transient position or a holding position by controlling a plurality of signal pressures together with a spring biasing force and a counter pressure against the spring biasing force, a transient hydraulic pressure or a higher holding hydraulic pressure is supplied to the forward / reverse switching mechanism. A switching valve, a belt clamping pressure control valve that supplies hydraulic pressure to the driven oil chamber by the spring urging force, the counter pressure, and the signal pressure, a hydraulic pressure sensor that detects the hydraulic pressure of the driven oil chamber, and the switching A continuously variable transmission for a vehicle, comprising: a transient hydraulic pressure control valve that supplies a transient hydraulic pressure to the valve and raises the transient hydraulic pressure to a predetermined hydraulic pressure when a detected value of the hydraulic pressure sensor is higher than a predetermined value. Device.

  According to the present invention, when the counter pressure is lowered due to a failure, the counter pressure supplied to the belt clamping pressure control valve is lowered, causing a change in the control of the belt clamping pressure control valve, to the driven oil chamber. The hydraulic pressure is excessive. In this case, the hydraulic pressure to the driven oil chamber is detected by a hydraulic pressure sensor, and when the detected value of the hydraulic pressure sensor is equal to or higher than a predetermined value, it is determined that slippage of the clutch has occurred. It is not necessary to detect the turbine rotational speed for detection, and therefore the number of parts and the cost can be reduced by the amount of the turbine rotational speed detection sensor.

1 is a schematic configuration diagram of a continuously variable transmission for a vehicle according to an embodiment of the present invention. It is a schematic block diagram of the hydraulic control apparatus used for the said continuously variable transmission. FIG. 2 is a schematic configuration diagram of a garage shift valve (switching valve) of the hydraulic control device. It is a schematic block diagram of the belt clamping pressure control valve of the hydraulic control device.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  1 to 4 are diagrams for explaining a continuously variable transmission for an automobile according to an embodiment of the present invention.

  In FIG. 1, reference numeral 50 denotes an FF horizontal type continuously variable transmission for an automobile. The continuously variable transmission 50 includes an input shaft 3 that is driven by the engine output shaft 1 via the torque converter 2, and a forward / reverse switching mechanism 4 that transmits the rotation of the input shaft 3 to the drive shaft 10 by switching between forward and reverse rotation. The belt type continuously variable transmission 8 in which the V belt 15 is wound around the drive pulley 11 and the driven pulley 21, the differential device 23 that transmits the power of the driven shaft 20 to the output shaft 21, and the like. The V belt 15 is a known metal belt composed of a pair of endless tension bands and a number of blocks supported by these tension bands.

  A mechanical oil pump 6 is disposed between the torque converter 2 and the forward / reverse switching mechanism 4. The oil pump 6 is driven by a pump impeller 2 a of the torque converter 2. The turbine runner 2b of the torque converter 2 is connected to the input shaft 3, and the stator 2c is supported by the case via a one-way clutch 2d. A lockup clutch 2f is provided between the input shaft 3 and the pump impeller 2a.

  The forward / reverse switching mechanism 4 includes a planetary gear mechanism 7, a reverse brake B1, and a direct clutch C1. The sun gear 7 a of the planetary gear mechanism 7 is connected to the input shaft 3, and the ring gear 7 b is connected to the drive shaft 10. This planetary gear mechanism 7 is a single pinion system, the reverse brake B1 is provided between the carrier 7c supporting the pinion gear 7d and the transmission case 5, and the direct clutch C1 is between the carrier 7c and the sun gear 7a or the input shaft 3. Is provided.

  When the direct clutch C1 is released and the reverse brake B1 is engaged, the rotation of the input shaft 3 is reversed and decelerated and transmitted to the drive shaft 10 to enter the forward traveling state. On the other hand, when the reverse brake B1 is released and the direct clutch C1 is engaged, the carrier 7c and the sun gear 7a of the planetary gear mechanism 7 rotate together, so that the input shaft 3 and the drive shaft 10 are directly connected, and the reverse traveling state is established. Become.

  Accordingly, the reverse brake B1 and the direct coupling clutch C1 are engaged only in the travel range (D range, R range, etc.), and are released in the non-travel range (N range, P range).

  The drive pulley 11 of the belt type continuously variable transmission 8 includes a fixed sheave 11a integrally formed on the drive shaft 10 and a movable sheave supported on the drive shaft 10 so as to be axially movable and integrally rotatable. 11b and a drive side oil chamber 12 provided behind the movable sheave 11b. Shift control is performed by controlling the amount of oil to the drive side oil chamber 12.

  The driven pulley 21 includes a fixed sheave 21a integrally formed on the driven shaft 20, a movable sheave 21b supported on the driven shaft 20 so as to be axially movable and integrally rotatable, and behind the movable sheave 21b. And a driven oil chamber 22 which is a belt clamping pressure means provided in By controlling the oil pressure in the driven oil chamber 22, a belt clamping pressure necessary for torque transmission is applied. Note that a spring for applying an initial clamping pressure may be disposed in the driven oil chamber 22.

  One end of the driven shaft 20 extends toward the engine side, and an output gear 24 is fixed to the one end. The output gear 24 meshes with the ring gear 25 of the differential device 23, and power is transmitted from the differential device 23 to output shafts 23a and 23a extending left and right to drive the wheels.

  FIG. 2 shows only the control circuit portion and the shift control circuit portion of the reverse brake B1 and the direct clutch C1 constituting the forward / reverse switching mechanism 4 of the hydraulic control device 60 used in the continuously variable transmission 50. .

  In FIG. 2, 61 is a regulator valve, 62 is a clutch modulator valve, 63 is a solenoid modulator valve, 64 is a garage shift valve (switching valve), 65 is a manual valve, 66 is a ratio control valve for downshift, and 67 is for upshift. A ratio control valve, 68 is a ratio check valve, and 69 is a belt clamping pressure control valve. In addition, SLS is a solenoid valve that regulates the transient hydraulic pressure of the direct clutch C1 and the reverse brake B1 of the forward / reverse switching mechanism 4, DS1 is an upshift solenoid valve that regulates and controls the upshift signal pressure Pds1, and DS2 is This is a solenoid valve for downshift that regulates and controls the downshift signal pressure Pds2.

The regulator valve 61 is a valve that regulates the discharge pressure of the oil pump 6 to the line pressure P _L corresponding to the signal oil pressure input to the signal port 61a.

The clutch modulator valve 62 is a valve that regulates the clutch pressure supplied to the direct coupling clutch C1 and the reverse brake B1. The line pressure P _L is input to the input port 62a, and the clutch modulator pressure Pcm is output from the output port 62b. The output pressure is fed back to the first signal port 62c so as to face the spring load that urges the spool. Therefore, the forward clutch pressure is the same as the line pressure when the line pressure P _L is less than or equal to a predetermined value, and is limited to a constant pressure when the line pressure P _L exceeds the predetermined value.

  The manual valve 65 is a manually operated valve that is mechanically connected to a shift lever. The manual valve 65 is switched to each range of P, R, N, D, S, and B, and directly connects the hydraulic pressure supplied from the garage shift valve 64. It selectively leads to the clutch C1 or the reverse brake B1. The input port 65a is supplied with hydraulic pressure from the garage shift valve 64, the output port 65b is connected to the direct clutch C1, and the output ports 65c and 65d are both connected to the reverse brake B1. The manual valve 65 supplies hydraulic pressure to the direct clutch C1 and drains the reverse brake B1 in the R range, and supplies hydraulic pressure to the reverse brake B1 and drains the direct clutch C1 in the D, S, and B ranges. In the P and N ranges, which are non-traveling ranges, the hydraulic pressures of the direct clutch C1 and the reverse brake B1 are drained together.

  The solenoid modulator valve 63 is a valve that regulates the output pressure of the clutch modulator valve 62 to generate a constant solenoid modulator pressure Psm. The solenoid modulator pressure Psm is supplied to the downshift and upshift solenoid valves DS2, DS1.

  Furthermore, in this embodiment, as will be described later, the solenoid modulator pressure Psm is also supplied to the garage shift valve 64 and the belt clamping pressure control valve 69.

  The upshift ratio control valve 67 adjusts the amount of hydraulic oil supplied to and discharged from the drive side oil chamber 12 of the drive pulley 11. The downshift ratio control valve 66 controls the flow rate of hydraulic oil supplied to and discharged from the driven oil chamber 22 of the driven pulley 21. Furthermore, the ratio check valve 68 sets the ratio between the hydraulic pressure in the driving side oil chamber 12 and the hydraulic pressure in the driven side oil chamber 22 in a preset relationship.

  As shown in FIG. 4, the belt clamping pressure control valve 69 has a spool 69b slidably disposed in the valve body 69a, a spring 69c disposed at one end of the valve body 69a, and the spool 69b. It has a structure for biasing to the other end side.

The solenoid valve SLS is connected to a port 69d communicating with the arrangement chamber of the spring 69c of the belt clamping pressure control valve 69, and the solenoid modulator valve 63 is connected to a port 69f opened at the opposite end of the spring 69c. It is connected. The line pressure P _L is input to the input port 69e, and the output port 69g is connected to the driven side oil chamber 22 of the driven pulley 21.

The belt clamping pressure control valve 69 uses the solenoid modulator pressure Psls from the solenoid valve SLS as a signal pressure and continuously regulates the line pressure P _{L so} that the belt 15 does not slip. Psec is output to the driven oil chamber 22. In this case, the belt clamping pressure Psec is detected by the pressure sensor 26, and the detected value is fed back to the solenoid valve SLS.

  The garage shift valve 64 switches the oil path so that the supply pressure to the reverse brake B1 or the direct coupling clutch C1 can be transiently controlled when the shift lever is switched from N to D or N to R (in garage shift). This is a switching valve.

  In the garage shift valve 64, as shown in FIG. 3, a spool 64h is inserted into the valve body 64f so as to be movable in the axial direction, and the spool 64h is the same as the signal pressure acting direction of the solenoid valves DS1 and DS2. A spring 64g that biases in the direction is disposed. As a result, the spool 64ha can be switched to the transient position D on the left side of the center line in FIG. 3 regardless of the signal pressure of the solenoid valves DS1 and DS2.

  On the other hand, a counter port 64i that introduces hydraulic pressure in a direction opposite to the urging force of the spring 64g is provided at the end of the valve body 64f opposite to the spring 64g.

  When the engine is started after the idle stop is released, the solenoid modulator pressure Psm is supplied to the counter port 64i in a low pressure state, while the signal pressures Pds1 and Pds2 from the solenoid valves DS1 and DS2 are also in the low pressure state. , 64a. In this state, the garage shift valve 64 is held at the transient position D on the left side of the center line in FIG. 3 by the urging force of the spring 64g. Thereafter, when the solenoid modulator pressure Psm rises to the normal pressure, the signal pressure is also in the normal pressure state at the same time. Therefore, the garage shift valve 64 is held at the transient position even in this normal pressure state. Then, the transient hydraulic pressure Psls (control pressure) controlled by the solenoid valve SLS is supplied to the manual valve 65 through the ports 64c to 64d, and is supplied to the direct coupling clutch C1 or the reverse brake B1 depending on the rotational position of the shift lever. The

  When the transient oil pressure Psls rises to the required oil pressure, at least one of the signal pressures Pds1 and Pds2 is drained by the solenoid valve DS1 or DS2, so that the spool 64h is positioned at the holding position E on the right side of the center line in FIG. Can be switched. As a result, the clutch modulator pressure Pcm (holding pressure) is supplied to the direct clutch C1 or the reverse brake B1 via the manual valve 65.

  Thus, in the present embodiment, when the solenoid modulator pressure Psm is supplied in a low pressure state, the garage shift valve 64 also supplies the signal pressures Pds1, Pds2 from the solenoid valves DS1, DS2 in a low pressure state. Therefore, when the solenoid modulator pressure Psm rises to the normal pressure, the signal pressures Pds1 and Pds2 are also in the normal pressure state at the same time. Therefore, even in this normal pressure state, the signal is held at the transient position. Accordingly, the slippage of the belt can be prevented by controlling the torque capacity of the reverse brake B1 or the direct coupling clutch C1 for forward / reverse switching so as not to exceed the belt transmission torque capacity by the transient hydraulic pressure Psls.

  Here, in the present embodiment, when the hydraulic pressure reaches a predetermined signal pressure, the solenoid modulator pressure Psm, which is the original pressure of the signal pressure, is supplied to the counter port 64i and remains in a state where it is opposed to the spring force. The shift valve 64 can be switched to the holding position E. Therefore, if the solenoid modulator pressure Psm is not supplied by the valve block or the like, the garage shift valve 64 cannot be switched to the holding position E, and there is a possibility that traveling such as a steep slope becomes impossible.

On the other hand, if the solenoid modulator pressure Psm is not supplied during the steady running, the solenoid modulator pressure Psm is not supplied to the port 69f of the belt clamping pressure control valve 69. The second position on the left side is entered, the line pressure P _L is supplied to the driven oil chamber 22 as it is, and the detection value of the pressure sensor 26 becomes higher than when the solenoid modulator pressure Psm is supplied. Accordingly, by monitoring the detection value of the hydraulic pressure sensor 26 in the driven oil chamber 22, slippage of the reverse brake B1 or the direct coupling clutch C1 can be detected.

  Therefore, in this embodiment, when the detected value of the pressure sensor 26 is higher than a predetermined value, it is determined that the slip of the reverse brake B1 or the like has occurred. When slippage of the reverse brake B1 or the like is detected, pressure regulation control is performed so that the output pressure of the solenoid valve SLS becomes higher, specifically, a pressure that can secure a necessary clutch transmission torque. . This regulated pressure-controlled solenoid pressure Psls' is supplied from the garage shift valve 64 to the reverse brake B1 or the direct coupling clutch C1 via the manual valve 65.

  As described above, in this embodiment, when the solenoid modulator pressure Psm is not supplied by the valve block or the like and the garage shift valve 64 is not switched to the holding position even during steady running, the solenoid pressure Psls from the solenoid valve SLS is Is adjusted to the solenoid pressure Psls ′ so that the required clutch transmission torque can be secured, and supplied to the reverse brake B1 and the like, so that the reverse brake B1 and the like can be prevented from slipping.

  In the pressure regulation control of the solenoid pressure Psls, when the detection value of the pressure sensor 26 provided for feeding back the hydraulic pressure detection value in the driven side oil chamber 22 becomes higher than the normal belt clamping pressure Psec, Since it is determined that slippage of the clutch or the like has occurred and the solenoid pressure Psls is increased, it is not necessary to detect the turbine rotation speed, and therefore a turbine rotation speed detection sensor is unnecessary, and the number of parts and cost are reduced. Can be reduced.

4 Forward / reverse switching mechanism 8 Belt type continuously variable transmission 11 Drive pulley 12 Drive side oil chamber 15 Belt 21 Drive side pulley 22 Drive side oil chamber 26 Hydraulic sensor 50 Continuously variable transmission 64 Garage shift valve (switching valve)
64g Spring 69 Belt clamping pressure control valve D Transient position E Holding position Pcm Holding hydraulic pressure Psec Belt clamping pressure (hydraulic pressure of the driven oil chamber)
Psm Solenoid modulator pressure (holding signal pressure)
Psls Transient oil pressure SLS Solenoid valve (transient oil pressure control valve)

Claims (1)

A belt type continuously variable transmission in which a driving pulley having a driving oil chamber and a driven pulley having a driven oil chamber are connected by a belt;
A forward / reverse switching mechanism for switching the engine rotation to a forward or reverse direction by hydraulic pressure and transmitting the rotation to the continuously variable transmission;
By switching to a transient position or a holding position by controlling a plurality of signal pressures together with a spring biasing force and a counter pressure against the spring biasing force, a transient hydraulic pressure or a higher holding hydraulic pressure is supplied to the forward / reverse switching mechanism. A switching valve;
A belt clamping pressure control valve for supplying hydraulic pressure to the driven oil chamber by the spring biasing force, the counter pressure and the signal pressure;
A hydraulic sensor for detecting the hydraulic pressure of the driven oil chamber;
And a transient oil pressure control valve for supplying a transient oil pressure to the switching valve and increasing the transient oil pressure to a predetermined oil pressure when a detected value of the oil pressure sensor is higher than a predetermined value. Step transmission.

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