JP2006177494A - Controller of belt type continuously variable transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress the variation of belt holding pressure accompanied by a gear shift. <P>SOLUTION: When the gear shift is performed (YES in S100), an ECU implements a program having a step for calculating a duty indication value to a duty solenoid for gear shift control (S102), a step for calculating the corrected amount of target belt holding pressure based on the duty indication value (S104), and a step for calculating a belt holding pressure indication value to a linear solenoid for belt holding pressure control based on target pressure formed by deducting the corrected amount from the target belt holding pressure (S106). <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a control device for a belt-type continuously variable transmission, and more particularly to a technique for controlling a belt clamping pressure.

  Conventionally, belt-type continuously variable transmissions, planetary gear-type stepped transmissions, and toroidal-type continuously variable transmissions are known as automatic transmissions configured to hydraulically control the transmission mechanism. Of these, the belt-type continuously variable transmission includes an input shaft to which engine torque is input, an output shaft provided in parallel with the input shaft, a primary pulley provided on the input shaft side, and an output shaft side. And a secondary pulley provided. The primary pulley has a fixed sheave fixed to the input shaft and a movable sheave movable in the axial direction of the input shaft. The secondary pulley has a fixed sheave fixed to the output shaft and a movable sheave movable in the axial direction of the output shaft. A belt is wound around the primary pulley and the secondary pulley configured as described above. Furthermore, a first hydraulic chamber (fluid pressure chamber) that controls the operation of the movable sheave of the primary pulley and a second hydraulic chamber that controls the operation of the movable sheave of the secondary pulley are provided. By controlling the hydraulic pressure in the first hydraulic chamber, the groove width of the primary pulley, in other words, the winding radius of the belt on the primary pulley side changes, and the gear ratio is controlled. Further, by controlling the hydraulic pressure in the second hydraulic chamber, the clamping force with respect to the belt is controlled, and the tension corresponding to the transmission torque is ensured.

  As disclosed in Japanese Patent Laid-Open No. 2002-340158 (Patent Document 1), the hydraulic pressure supplied to the first hydraulic chamber (hydraulic cylinder of the primary pulley) is controlled by an electromagnetic on-off valve and a flow control valve for upshifting. And a downshift electromagnetic on-off valve and a flow control valve. When the up-shift electromagnetic on-off valve is duty controlled, a predetermined control pressure obtained by reducing the modulator pressure is output to the flow control valve, and the line pressure adjusted in accordance with the control pressure is supplied from the supply path to the primary pulley. Supplied to the hydraulic cylinder. As a result, the groove width becomes narrower and the transmission ratio becomes smaller. When the down-shifting electromagnetic on-off valve is duty controlled, a predetermined control pressure that reduces the modulator pressure is output to the flow control valve, and the drain port is opened in response to the control pressure, thereby operating the primary pulley. Oil is drained from the discharge path at a predetermined flow rate, the groove width is widened, and the gear ratio is increased.

The hydraulic pressure supplied to the second hydraulic chamber (hydraulic cylinder of the secondary pulley) is controlled by the clamping pressure control valve so that the belt does not slip. The clamping pressure control valve is supplied with line hydraulic pressure, signal pressure, and modulator pressure. The hydraulic pressure supplied to the hydraulic cylinder of the secondary pulley is continuously controlled according to the signal pressure output from the linear solenoid valve. As the hydraulic pressure increases, the belt clamping pressure increases and the transmission torque capacity increases.
JP 2002-340158 A

  However, as described in Japanese Patent Laid-Open No. 2002-340158, when the modulator pressure is supplied to the up-shift electromagnetic on-off valve, the down-shift electromagnetic on-off valve, and the clamping pressure control valve, the belt is clamped during shifting. The pressure can vary. That is, when the up-shift electromagnetic on-off valve or down-shift electromagnetic on-off valve is duty-controlled and the output of the control pressure increases, the modulator pressure is temporarily reduced accordingly. Thereby, the modulator pressure supplied to the clamping pressure control valve is reduced, and the hydraulic pressure supplied to the hydraulic cylinder of the secondary pulley is increased. Therefore, the belt clamping pressure is increased more than necessary. In this case, there was a problem that the durability and fuel consumption of the belt deteriorated.

  The present invention has been made to solve the above-described problems, and an object thereof is to provide a hydraulic control device for a belt-type continuously variable transmission that can suppress deterioration of belt durability and fuel consumption. It is to be.

  A hydraulic control device for a belt-type continuously variable transmission according to a first aspect of the present invention includes an adjustment mechanism that adjusts a hydraulic pressure from a hydraulic source to a predetermined hydraulic pressure, and a hydraulic pressure and an adjustment mechanism that are supplied from a first electromagnetic valve. From the control valve that controls the clamping pressure of the belt based on the adjusted hydraulic pressure, the second electromagnetic valve that changes the gear ratio by controlling the hydraulic pressure adjusted by the adjustment mechanism, and the second electromagnetic valve Means for detecting information relating to the supplied hydraulic pressure and control means for controlling the first electromagnetic valve based on information relating to the hydraulic pressure supplied from the second electromagnetic valve.

  According to the first invention, when the output from the second electromagnetic valve fluctuates, the hydraulic pressure adjusted by the adjusting mechanism (the original pressure of the second electromagnetic valve) fluctuates temporarily. Therefore, in the control valve, the balance between the hydraulic pressure supplied from the first electromagnetic valve and the hydraulic pressure adjusted by the adjusting mechanism may be lost, and the clamping pressure of the belt may fluctuate. In order to suppress the fluctuation of the clamping pressure amount of the belt, the first electromagnetic valve is controlled based on the information regarding the hydraulic pressure supplied from the second electromagnetic valve. That is, the first solenoid valve is controlled in accordance with the fluctuation of the hydraulic pressure adjusted by the adjusting mechanism. Thereby, in the control valve, the balance between the hydraulic pressure supplied from the first electromagnetic valve and the hydraulic pressure adjusted by the adjusting mechanism can be maintained. Therefore, fluctuations in the clamping pressure of the belt can be suppressed, and an increase in the clamping pressure more than necessary can be suppressed. As a result, it is possible to provide a hydraulic control device for a belt-type continuously variable transmission that can suppress deterioration of belt durability and fuel consumption.

  In the hydraulic control device for a belt-type continuously variable transmission according to the second invention, in addition to the configuration of the first invention, the control valve increases the clamping pressure of the belt when the hydraulic pressure supplied from the adjustment mechanism decreases. When the hydraulic pressure supplied from the first solenoid valve decreases, the belt clamping pressure is reduced. The control means includes means for reducing the hydraulic pressure supplied from the first electromagnetic valve when the hydraulic pressure supplied from the second electromagnetic valve increases.

  According to the second invention, when the hydraulic pressure supplied from the second electromagnetic valve increases and the hydraulic pressure supplied from the adjustment mechanism decreases, if the hydraulic pressure supplied from the first electromagnetic valve is the same, The clamping pressure of the belt is increased. In order to suppress an increase in the clamping pressure, the hydraulic pressure supplied from the first electromagnetic valve is reduced, and the clamping pressure is reduced so as to offset the increase in the clamping pressure. Thereby, the fluctuation | variation of the clamping pressure of a belt can be suppressed and it can suppress that a clamping pressure increases more than necessary.

  In the hydraulic control device for a belt-type continuously variable transmission according to the third aspect of the invention, in addition to the configuration of the second aspect of the invention, the control means increases the first electromagnetic pressure as the hydraulic pressure supplied from the second electromagnetic valve increases. Means for lowering the hydraulic pressure supplied from the valve.

  According to the third aspect of the invention, the greater the hydraulic pressure supplied from the second electromagnetic valve, the greater the amount of decrease in the hydraulic pressure supplied from the adjustment mechanism. Therefore, the hydraulic pressure supplied from the first electromagnetic valve is further reduced. Thereby, the fluctuation | variation of the clamping pressure of a belt can be suppressed and it can suppress that a clamping pressure increases more than necessary.

  In addition to the configuration of the first invention, the hydraulic control device for a belt type continuously variable transmission according to the fourth invention further includes means for detecting the temperature of the hydraulic oil. The control means includes means for controlling the first electromagnetic valve based on the temperature of the hydraulic oil in addition to the information regarding the hydraulic pressure supplied from the second electromagnetic valve.

  According to the fourth aspect of the invention, the higher the temperature of the hydraulic oil, the lower the viscosity. Therefore, the amount of hydraulic oil leaked from the adjustment mechanism, the second electromagnetic valve, or the like increases. Therefore, the fluctuation amount of the hydraulic pressure supplied from the adjustment mechanism due to the fluctuation of the hydraulic pressure supplied from the second electromagnetic valve becomes large. Therefore, for example, the higher the temperature of the hydraulic oil, the lower the hydraulic pressure supplied from the first solenoid valve. Thereby, the fluctuation | variation of the clamping pressure of a belt can be suppressed.

  In the hydraulic control device for a belt-type continuously variable transmission according to the fifth invention, in addition to the configuration of the fourth invention, the control valve increases the clamping pressure of the belt when the hydraulic pressure supplied from the adjusting mechanism decreases. When the hydraulic pressure supplied from the first solenoid valve decreases, the belt clamping pressure is reduced. The control means includes means for lowering the hydraulic pressure supplied from the first electromagnetic valve as the temperature of the hydraulic oil is higher.

  According to the fifth aspect of the invention, the higher the temperature of the hydraulic oil, the lower the viscosity. Therefore, the amount of hydraulic oil leaked from the adjustment mechanism second electromagnetic valve or the like increases. Therefore, the fluctuation amount of the hydraulic pressure supplied from the adjustment mechanism due to the fluctuation of the hydraulic pressure supplied from the second electromagnetic valve becomes large. Therefore, the higher the temperature of the hydraulic oil, the lower the hydraulic pressure supplied from the first solenoid valve. Thereby, the fluctuation | variation of the clamping pressure of a belt can be suppressed and it can suppress that a clamping pressure increases more than necessary.

  A hydraulic control apparatus for a belt-type continuously variable transmission according to a sixth aspect of the invention further includes means for detecting information relating to the hydraulic pressure supplied from the hydraulic source in addition to the configuration of the first aspect of the invention. The control means includes means for controlling the first electromagnetic valve based on information related to the hydraulic pressure supplied from the hydraulic source in addition to information related to the hydraulic pressure supplied from the second electromagnetic valve.

  According to the sixth aspect of the invention, the smaller the hydraulic pressure supplied from the hydraulic power source, the larger the fluctuation amount of the hydraulic pressure supplied from the adjustment mechanism due to the fluctuation of the hydraulic pressure supplied from the second electromagnetic valve. Therefore, for example, the smaller the hydraulic pressure supplied from the hydraulic source, the lower the hydraulic pressure supplied from the first electromagnetic valve. Thereby, the fluctuation | variation of the clamping pressure of a belt can be suppressed.

  In the hydraulic control device for a belt-type continuously variable transmission according to the seventh invention, in addition to the configuration of the sixth invention, the control valve increases the clamping pressure of the belt when the hydraulic pressure supplied from the adjustment mechanism decreases. When the hydraulic pressure supplied from the first solenoid valve decreases, the belt clamping pressure is reduced. The control means includes means for lowering the hydraulic pressure supplied from the first solenoid valve as the hydraulic pressure supplied from the hydraulic pressure source is smaller.

  According to the seventh aspect of the invention, the smaller the hydraulic pressure supplied from the hydraulic source, the larger the fluctuation amount of the hydraulic pressure supplied from the adjusting mechanism due to the fluctuation of the hydraulic pressure supplied from the second electromagnetic valve. Therefore, the smaller the hydraulic pressure supplied from the hydraulic source, the lower the hydraulic pressure supplied from the first solenoid valve. Thereby, the fluctuation | variation of the clamping pressure of a belt can be suppressed and it can suppress that a clamping pressure increases more than necessary.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

  With reference to FIG. 1, a power train of a vehicle including a hydraulic control device according to the present embodiment will be described. The hydraulic control apparatus according to the present embodiment is applied to the power train shown in FIG. 1 and is realized by, for example, ECU (Electronic Control Unit) 1000 and hydraulic control unit 1100. In describing the hydraulic circuit of the hydraulic control unit 1100, the power train will be described first.

  As shown in FIG. 1, the power train of this vehicle includes an engine 100, a torque converter 200, a forward / reverse switching device 290, a belt-type continuously variable transmission (CVT) 300, a differential gear 800, The ECU 1000 and a hydraulic control unit 1100 are configured.

  The output shaft of engine 100 is connected to the input shaft of torque converter 200. Engine 100 and torque converter 200 are connected by a rotating shaft. Therefore, output shaft rotational speed NE (engine rotational speed NE) of engine 100 detected by the engine rotational speed sensor and input shaft rotational speed (pump rotational speed) of torque converter 200 are the same. The engine speed NE is detected by the engine speed sensor 102.

  The torque converter 200 includes a lock-up clutch 210 that directly connects the input shaft and the output shaft, a pump impeller 220 on the input shaft side, a turbine impeller 230 on the output shaft side, and a one-way clutch 250. It is comprised from the stator 240 which expresses an amplification function. Torque converter 200 and CVT 300 are connected by a rotating shaft. The output shaft rotational speed NT (turbine rotational speed NT) of the torque converter 200 is detected by the turbine rotational speed sensor 400.

  CVT 300 is connected to torque converter 200 via forward / reverse switching device 290. The CVT 300 includes an input side primary pulley 500, an output side secondary pulley 600, and a metal belt 700 wound around the primary pulley 500 and the secondary pulley 600. Primary pulley 500 includes a fixed sheave fixed to the primary shaft and a movable sheave supported on the primary shaft so as to be slidable only. The secondary pulley 600 includes a fixed sheave fixed to the secondary shaft and a movable sheave supported by the secondary shaft so as to be slidable only. The primary pulley rotational speed NIN of the CVT 300 is detected by the primary pulley rotational speed sensor 410, and the secondary pulley rotational speed NOUT is detected by the secondary pulley rotational speed sensor 420.

  These rotation speed sensors are provided to face the rotation detection gear teeth attached to the rotation shafts of the primary pulley 500 and the secondary pulley 600 and the drive shaft connected thereto. These rotational speed sensors are sensors capable of detecting a slight rotation of the primary pulley 500 serving as an input shaft and the secondary pulley 600 serving as an output shaft of the CVT 300. For example, the rotational speed sensors are generally referred to as semiconductor sensors. This is a sensor using a magnetoresistive element.

  The forward / reverse switching device 290 includes a double pinion planetary gear, a reverse (reverse) brake B1 and an input clutch C1. In the planetary gear, its sun gear is connected to the input shaft, the carrier CR supporting the first and second pinions P1, P2 is connected to the primary side fixed sheave, and the ring gear R is a reverse friction engagement element. The reverse brake B1 is connected, and an input clutch C1 is interposed between the carrier CR and the ring gear R. The input clutch 310 is also called a forward clutch or a forward clutch, and is always used in an engaged state when a vehicle other than the parking (P) position, the R position, and the N position moves forward.

  The forward / reverse switching device 290 is operated by the hydraulic pressure of the hydraulic oil generated by the oil pump 900. The oil pump 900 is connected to the pump impeller 220 side of the torque converter 200. That is, oil pump 900 is driven by engine 100. The rotational speed of the oil pump 900 is the same as the engine rotational speed NE. The hydraulic pressure of the hydraulic oil increases as the rotational speed of the oil pump 900, that is, the engine rotational speed NE increases. The oil pressure generated by the oil pump 900 is adjusted to a desired oil pressure in a later-described hydraulic circuit. The oil temperature of the hydraulic oil is detected by an oil temperature sensor 430.

  The ECU 1000 and the hydraulic control unit 1100 that control these power trains will be described with reference to FIG.

  As shown in FIG. 2, ECU 1000 has a signal representing engine speed NE from engine speed sensor 102, a signal representing turbine speed NT from turbine speed sensor 400, and a signal representing turbine speed NT from primary pulley speed sensor 410 to primary pulley. A signal representing the rotational speed NIN is input from the secondary pulley rotational speed sensor 420 to a signal representing the secondary pulley rotational speed NOUT, and a signal representing the hydraulic oil temperature from the oil temperature sensor 430 is input.

  As shown in FIGS. 1 and 2, the hydraulic pressure control unit 1100 includes a shift speed control unit 1110, a belt clamping pressure control unit 1120, a lockup engagement pressure control unit 1130, a clutch pressure control unit 1140, and a manual valve. 1150. From the ECU 1000, a shift control duty solenoid (1) 1200, a shift control duty solenoid (2) 1210, a belt clamping pressure control linear solenoid 1220, a lockup solenoid 1230, and a lockup engagement from the ECU 1000. A control signal is output to the pressure control duty solenoid 1240.

  The structure of ECU 1000 that controls these power trains will be described in more detail with reference to FIG. As shown in FIG. 2, ECU 1000 includes an engine control computer 1010 that controls engine 100 and a transmission control computer 1020 that controls CVT 300.

  In addition to the input / output signals shown in FIG. 1, the transmission control computer 1020 receives a stop lamp switch, a signal indicating that the brake pedal is being depressed by the driver, and a G sensor from which the vehicle stops on an uphill road or the like. Each of the signals indicating the slope of the uphill road is input. Further, the engine control computer 1010 receives a signal representing the opening of the accelerator being stepped on by the driver from the accelerator opening sensor and a signal representing the opening of the electromagnetic throttle from the throttle position sensor. Engine control computer 1010 and transmission control computer 1020 are connected to each other.

  In the hydraulic control unit 1100, the belt clamping pressure control unit 1120 controls the clamping pressure of the belt 700 of the CVT 300 based on the control signal output from the transmission control computer 1020 to the belt clamping pressure control linear solenoid 1220. The pressure control unit 1140 controls the engagement pressure of the input clutch 310.

  In hydraulic control unit 1100, shift speed control unit 1110 performs CVT 300 based on control signals output from transmission control computer 1020 to shift control duty solenoid (1) 1200 and shift control duty solenoid (2) 1210. The gear ratio is controlled.

  A hydraulic circuit including important components of the hydraulic control apparatus according to the embodiment of the present invention will be described with reference to FIGS. 3 and 4. Since details of the entire hydraulic circuit other than those shown in FIGS. 3 and 4 are disclosed in Japanese Patent Laid-Open No. 2002-181175, detailed description thereof will not be repeated here.

  With reference to FIG. 3, a hydraulic circuit that performs shift control will be described.

  The supply and discharge of hydraulic oil to and from the primary pulley 500 is performed by flow rate control. The valve mechanism for that purpose is configured as shown in FIG. That is, the hydraulic actuator of primary pulley 500 communicates with first flow control valve 2100 that supplies line pressure PL and second flow control valve 2200 connected to the drain. The first flow control valve 2100 is a valve for executing an upshift, and is a flow path between an input port 2102 to which a line pressure PL is supplied and an output port 2104 communicated with the hydraulic actuator of the primary pulley 500. Is configured to be opened and closed by a spool 2106. A spring 2108 is disposed at one end of the spool 2106, and a first signal pressure port 2110 for applying a signal pressure is formed at an end opposite to the spring 2108 across the spool 2106. Yes. A second signal pressure port 2112 for applying a signal pressure is formed on the one end side where the spring 2108 is disposed.

  The first signal pressure port 2110 is connected to a shift control duty solenoid (1) 1200 that increases the output pressure according to the duty, and the second signal pressure port 2112 increases the output pressure according to the duty. A shift control duty solenoid (2) 1210 is connected, and the signal pressures output from the solenoid valves 120 and 1210 are applied to the signal pressure ports 2110 and 2112, respectively. That is, by increasing the hydraulic pressure applied to the first signal pressure port 2110 and opening the input port 2110, hydraulic oil is supplied from the output port 2104 to the hydraulic actuator of the primary pulley 500, and the groove width of the primary pulley 500 becomes narrow. As a result, the gear ratio is lowered. That is, it is upshifted. Further, by increasing the supply flow rate of hydraulic oil at that time, the speed change speed is increased.

  Further, the second flow control valve 2200 is a valve for performing a downshift, and the hydraulic pressure that is adjusted by using the first port 2202 communicated with the hydraulic actuator of the primary pulley 500 as the source pressure of the line pressure PL. Is configured to selectively communicate with the second port 2204 and the drain port 2206 through which a spool 2208 is supplied. A spring 2210 is disposed on one end of the spool 2208, and a first signal pressure port 2212 for applying a signal pressure is formed on the one end. A second signal pressure port 2214 for applying a signal pressure is formed at the end opposite to the spring 2210 across the spool 2208.

  Further, a shift control duty solenoid (1) 1200 is connected to the first signal pressure port 2212, and a shift control duty solenoid (2) 1210 is connected to the second signal pressure port 2214, and each signal pressure port 2212 is connected. , 2214 is applied with a signal pressure output from these solenoid valves 1200, 1210. That is, by increasing the hydraulic pressure applied to the second signal pressure port 2214 and causing the first port 2202 to communicate with the drain port 2206, the hydraulic oil is discharged from the hydraulic actuator of the primary pulley 500 and the groove width of the primary pulley 500 is increased. As a result, the transmission ratio is increased. That is, it is downshifted. Further, by increasing the discharge flow rate of the hydraulic oil at that time, the speed change speed is increased.

  Further, a pressure regulating valve 2300 is connected to the second port 2204 of the second flow rate control valve 2200. This pressure regulating valve 2300 has an input port 2306 to which a line pressure PL is supplied formed on the front side of a piston 2304 pressed by a spring 2302, and an output port communicating with the front side and the back side of the piston 2304. 2308, the output port 2308 of which is in communication with the second port 2204 of the second flow control valve 2200. Further, the line pressure PL is supplied to the input port 2306 through a double orifice 2310 having a small opening area. That is, the pressure regulating valve 2300 is configured such that a hydraulic pressure having a pressure obtained by subtracting the elastic force of the spring 2302 from the line pressure PL is generated at the output port 2308, that is, the second port 2204 of the second flow control valve 2200.

  More specifically, when the first port 2202 and the second port 2204 of the second flow control valve 2200 are communicated with the input port 2102 of the first flow control valve 2100 closed, the pressure regulating valve 2300 The hydraulic oil pressure adjusted in step 1 is supplied to the hydraulic actuator of the primary pulley 500 through the second port 2204. In this case, the flow rate is a very small amount limited by the double orifice 2310. As a result, the hydraulic pressure of the hydraulic actuator of the primary pulley 500 increases, but the hydraulic pressure of the hydraulic actuator acts on the back side of the piston 2304 in the pressure regulating valve 2300, so that the pressure increases the elastic force of the spring 2302 from the line pressure PL. When the reduced pressure is reached, the piston 2304 is pressed toward the input port 2306 and closes the input port 2306, thereby preventing further supply of hydraulic oil. Therefore, in a so-called closed (inclusive) state where hydraulic fluid is not supplied from the first flow control port 2100 to the hydraulic actuator of the primary pulley 500 and is not discharged from the second flow control valve 2200, the hydraulic pressure of the hydraulic actuator of the primary pulley 500 is However, the hydraulic pressure regulated by the pressure regulating valve 2300 (pressure lower than the line pressure PL) is maintained.

  Such a state of maintaining the hydraulic pressure is the same in the case where unavoidable leakage of hydraulic oil occurs during the closing control, and the hydraulic oil leaks from the hydraulic circuit, hydraulic control device, etc. When the hydraulic pressure of the hydraulic actuator decreases, the hydraulic oil is supplied little by little from the input port 2306 of the pressure regulating valve 2300 to the hydraulic actuator of the primary pulley 500, and the pressure regulation value by the pressure regulating valve 2300 is maintained. As a result, the shift state tends to be slightly upshifted, and the speed is gradually increased so that the gear ratio is gradually decreased.

  The shift control duty solenoid (1) 1200 and the shift control duty solenoid (2) 1210 are supplied with hydraulic pressure adjusted to a constant pressure by the modulator valve 2400.

  With reference to FIG. 4, a hydraulic circuit for controlling the clamping pressure of the belt 700 will be described.

  The hydraulic pressure of the hydraulic cylinder of the secondary pulley 600 is controlled by the clamping pressure control valve 2500 so that the belt 700 does not slip. The clamping pressure control valve 2500 is provided with a spool 2502 that is movable in the axial direction and a spring 2504 that biases the spool 2502 to one side.

  A belt clamping pressure control linear solenoid 1220 is connected to the first signal pressure port 2506 of the clamping pressure control valve 2500. A modulator valve 2400 is connected to the second signal pressure port 2508 of the clamping pressure control valve 2500.

  The clamping pressure control valve 2500 is clamped by a balance between the output hydraulic pressure of the belt clamping pressure control linear solenoid 1220 controlled by the transmission control computer 1020, the hydraulic pressure adjusted to a constant pressure by the modulator valve 2400, and the urging force of the spring 2504. The line pressure PL introduced into the pressure control valve 2500 is regulated and supplied to the hydraulic cylinder of the secondary pulley 600.

  When the desired hydraulic pressure is supplied to the hydraulic cylinder of the secondary pulley 600, when the hydraulic pressure from the modulator valve 2400 decreases or the hydraulic pressure from the belt clamping pressure control linear solenoid 1220 increases, the spool 2504 In FIG. 4, it moves upward. In this case, the hydraulic pressure supplied to the hydraulic cylinder of the secondary pulley 600 increases, and the belt clamping pressure increases.

  On the contrary, when the hydraulic pressure from the modulator valve 2400 increases or the hydraulic pressure from the belt clamping pressure control linear solenoid 1220 decreases from the state where the desired hydraulic pressure is supplied to the hydraulic cylinder of the secondary pulley 600, the spool 2504 moves downward in FIG. In this case, the hydraulic pressure supplied to the hydraulic cylinder of the secondary pulley 600 decreases, and the belt clamping pressure decreases.

  As shown in FIGS. 3 and 4, the shift control duty solenoid (1) 1200, the shift control duty solenoid (2) 1210, and the clamping pressure control valve 2500 are supplied with hydraulic pressure (modulator pressure PM) from the same modulator valve 2400. Supplied.

  If the output hydraulic pressure from the shift control duty solenoid (1) 1200 or the shift control duty solenoid (2) 1210 increases during the shift, the modulator pressure PM temporarily decreases by the increased amount. Therefore, at the time of shifting, the spool 2506 of the clamping pressure control valve 2500 moves upward in FIG. 4, and the belt clamping pressure becomes higher than necessary. In this case, the durability of the belt 700 is deteriorated. Moreover, since more hydraulic pressure than necessary is supplied to the hydraulic cylinder of the secondary pulley 600, the hydraulic pressure generated by the oil pump 900 is not used efficiently, and the fuel consumption is adversely affected.

  In order to suppress these problems, in this embodiment, the belt clamping pressure control linear solenoid 1220 is based on the output hydraulic pressure from the shift control duty solenoid (1) 1200 and the shift control duty solenoid (2) 1210. To control. Specifically, the belt clamping pressure instruction value for the belt clamping pressure control linear solenoid 1220 is calculated based on the duty instruction values for the transmission control duty solenoid (1) 1200 and the transmission control duty solenoid (2) 1210.

  The ECU 1000 will be further described with reference to FIG. As shown in FIG. 5, ECU 1000 includes an upshift duty instruction value calculation unit 1002, a downshift duty instruction value calculation unit 1004, and a correction amount calculation unit 1006. More specifically, duty instruction value calculation units 1002 and 1004 and correction amount calculation unit 1006 are included in transmission control computer 1020.

  Upshift duty command value calculation unit 1002 calculates a duty command value by converting an upshift gear shift command calculated based on the vehicle speed and the accelerator opening to a duty command value (duty ratio). The calculated duty instruction value is transmitted to the shift control duty solenoid (1) 1200. Shift control duty solenoid (1) 1200 outputs a hydraulic pressure corresponding to the transmitted duty instruction value. As a result, an upshift is performed.

  Similarly, downshift duty command value calculation unit 1004 calculates a duty command value by converting a downshift gear shift command calculated based on the vehicle speed and the accelerator opening to a duty command value (duty ratio). . The calculated duty instruction value is transmitted to the shift control duty solenoid (2) 1210. The shift control duty solenoid (2) 1210 outputs a hydraulic pressure corresponding to the transmitted duty instruction value. As a result, a downshift is performed.

  The correction amount calculation unit 1006 includes duty instruction values for the shift control duty solenoid (1) 1200 and the shift control duty solenoid (2) 1210, the engine speed NE detected by the engine speed sensor 102, and the oil temperature sensor 430. A correction amount of the belt clamping pressure target pressure is calculated based on the detected belt temperature of the hydraulic oil and the belt clamping pressure target pressure calculated from the input shaft torque of the primary pulley 500.

  A belt clamping pressure instruction value is calculated based on the target pressure obtained by subtracting the correction amount from the belt clamping pressure target pressure. The calculated belt clamping pressure instruction value is transmitted to the belt clamping pressure control linear solenoid 1220. The belt clamping pressure control linear solenoid 1220 outputs a hydraulic pressure corresponding to the transmitted belt clamping pressure instruction value.

  In the present embodiment, the correction amount of the belt clamping target pressure is calculated as a positive value, but a correction value that is a negative value may be calculated. In this case, the belt clamping pressure instruction value may be calculated based on a target pressure obtained by adding a correction value to the belt clamping pressure target pressure.

  As shown in FIG. 6, the correction amount of the belt clamping target pressure is calculated based on a map stored in the memory of ECU 1000. The map shown in FIG. 6 is for calculating the correction amount when the belt clamping target pressure calculated from the input shaft torque is larger than a predetermined value and the oil temperature is higher than a predetermined value. This is the map to use.

  As the duty instruction value increases, the output hydraulic pressure of the shift control duty solenoid (1) 1200 and the shift control duty solenoid (2) 1210 increases, so that the amount of decrease in the modulator pressure increases (the modulator pressure becomes lower). Therefore, as the duty instruction value increases, the correction amount of the belt clamping target pressure is calculated to be larger.

  Further, when the engine speed NE is small, that is, when the hydraulic pressure generated by the oil pump 900 as the hydraulic pressure source is low, the output hydraulic pressures of the shift control duty solenoid (1) 1200 and the shift control duty solenoid (2) 1210 are set. The resulting fluctuation (decrease) in modulator pressure is large. Therefore, even if the duty instruction value is the same, the correction amount of the belt clamping pressure target pressure is calculated larger as the engine speed NE is smaller. That is, the larger the engine speed NE, the smaller the correction amount for the target pressure of the belt clamping pressure.

  A plurality of maps corresponding to the belt clamping pressure target pressure calculated from the input shaft torque may be stored, and a correction amount corresponding to the belt clamping pressure target pressure may be calculated. In this case, a larger correction amount may be calculated as the belt clamping pressure target pressure is larger.

  Furthermore, when the oil temperature of the hydraulic oil is high, the viscosity of the hydraulic oil becomes low. In this case, the amount of leakage of hydraulic fluid from the oil passage or valve to which hydraulic fluid is supplied to the outside of the valve body increases. As the amount of hydraulic fluid leakage increases, the amount of fluctuation in the modulator pressure increases. Therefore, even if the duty instruction value is the same, a larger correction amount may be calculated as the oil temperature is higher.

  With reference to FIG. 7, a control structure of a program executed by ECU 1000 of the hydraulic control apparatus according to the present embodiment will be described.

  In step (hereinafter step is abbreviated as S) 100, ECU 1000 determines whether or not to perform a shift. Whether or not to perform the shift is determined by the ECU 100 based on the vehicle speed and the accelerator opening. Therefore, it is determined inside ECU 1000 whether or not to change gears. If shifting is to be performed (YES in S100), the process proceeds to S102. If not (NO in S102), this process ends.

  In S102, ECU 1000 calculates duty instruction values for shift control duty solenoids 1200 and 1210 from the upshift gearshift command or the downshift gearshift command calculated based on the vehicle speed and the accelerator opening.

  In S104, ECU 1000 calculates the correction amount of the belt clamping pressure target pressure based on the duty instruction value, the engine speed NE, the oil temperature, and the belt clamping pressure target pressure. In S106, ECU 1000 calculates a belt clamping pressure instruction value based on the target pressure obtained by subtracting the correction amount from the belt clamping pressure target pressure. Thereafter, this process ends.

  The operation of ECU 1000 of the hydraulic control apparatus according to the present embodiment based on the structure and flowchart as described above will be described.

  When shifting is performed while the vehicle is traveling (YES in S100), duty instruction values for shift control duty solenoids 1200 and 1210 are calculated (S102).

  The shift control duty solenoids 1200 and 1210 output a hydraulic pressure corresponding to the calculated duty instruction value, whereby the CVT 300 is shifted. At this time, due to the shift control duty solenoids 1200 and 1210 outputting hydraulic pressure, the modulator pressure, which is the original pressure of the shift control duty solenoids 1200 and 1210, temporarily decreases. As a result, the modulator pressure supplied to the clamping pressure control valve 2500 decreases. When the modulator pressure supplied to the clamping pressure control valve 2500 decreases, the hydraulic pressure supplied to the hydraulic cylinder of the secondary pulley 600 increases, and the belt clamping pressure can increase.

  In order to suppress an increase in the belt clamping pressure, a correction amount of the belt clamping target pressure is calculated (S104), and a belt clamping pressure instruction value is calculated based on the target pressure obtained by subtracting the correction amount from the belt clamping pressure target pressure. (S106). Thereby, the output hydraulic pressure of the linear solenoid 1220 for belt clamping pressure control is reduced. That is, the output hydraulic pressure of the linear solenoid 1220 for controlling the belt clamping pressure is reduced in correspondence with the expected decrease in the modulator pressure. Therefore, in the clamping pressure control valve 2500, the balance between the output hydraulic pressure of the belt clamping pressure control linear solenoid 1220, the modulator pressure, and the biasing force of the spring 2504 is maintained. As a result, before and after the start of shifting, fluctuations in the hydraulic pressure supplied to the hydraulic cylinders of the secondary pulley 600 are suppressed, and fluctuations in the belt clamping pressure are suppressed.

  As described above, the ECU of the hydraulic control apparatus according to the present embodiment calculates the correction amount of the belt clamping pressure target pressure based on the duty instruction value for the shift control duty solenoid when performing a shift. A belt clamping pressure instruction value is calculated based on a target pressure obtained by subtracting the correction amount from the belt clamping pressure target pressure. The belt clamping pressure control linear solenoid supplies a hydraulic pressure corresponding to the calculated belt clamping pressure instruction value to the clamping pressure control valve. Thereby, the output hydraulic pressure of the linear solenoid for belt clamping pressure control can be reduced at the time of shifting. Therefore, in the clamping pressure control valve, it is possible to maintain a balance between the output hydraulic pressure of the belt clamping pressure control linear solenoid, the modulator pressure, and the biasing force of the spring. As a result, the fluctuation of the hydraulic pressure supplied to the hydraulic cylinder of the secondary pulley can be suppressed before and after the start of the shift, and the fluctuation of the belt clamping pressure can be suppressed.

  In the present embodiment, the output hydraulic pressure of the belt clamping pressure control linear solenoid 1220 is reduced at the time of shifting, but when the belt clamping pressure tends to decrease at the time of shifting, the belt clamping pressure control linear The output hydraulic pressure of the solenoid 1220 may be increased.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

1 is a control block diagram of an automatic transmission to which a hydraulic control device according to an embodiment of the present invention is applied. FIG. 2 is a detailed view (No. 1) of the ECU shown in FIG. 1. It is FIG. (1) which shows the hydraulic circuit of the hydraulic control apparatus which concerns on embodiment of this invention. It is FIG. (2) which shows the hydraulic circuit of the hydraulic control apparatus which concerns on embodiment of this invention. FIG. 3 is a detailed view (No. 2) of the ECU shown in FIG. 1. It is a figure which shows the map memorize | stored in memory of ECU. It is a flowchart which shows the control structure of the program performed by ECU of the hydraulic control apparatus which concerns on embodiment of this invention.

Explanation of symbols

  100 engine, 102 engine speed sensor, 200 torque converter, 210 lock-up clutch, 220 pump impeller, 230 turbine impeller, 240 stator, 250 one-way clutch, 290 forward / reverse switching device, 300 input clutch, 400 turbine speed sensor , 410 primary pulley rotational speed sensor, 420 secondary pulley rotational speed sensor, 430 oil temperature sensor, 500 primary pulley, 600 secondary pulley, 700 belt, 800 differential gear, 900 oil pump, 1000 ECU, 1010 engine control computer, 1020 transmission control Computer, 1100 Hydraulic control unit, 1110 Shift speed control unit, 1120 Belt clamping pressure control unit 1130 Lockup engagement pressure control unit, 1140 Clutch pressure control unit, 1150 Manual valve, 1200 Shift control duty solenoid (1), 1210 Shift control duty solenoid (2), 1220 Belt clamping pressure control linear solenoid, 1230 Lock Up solenoid, 1240 Lock-up engagement pressure control duty solenoid, 2100 first flow control valve, 2200 second flow control valve, 2300 pressure regulating valve, 2400 modulator valve, 2500 clamping pressure control valve.

Claims (7)

An adjustment mechanism for adjusting the hydraulic pressure from the hydraulic source to a predetermined hydraulic pressure;
A control valve for controlling the clamping pressure of the belt based on the hydraulic pressure supplied from the first electromagnetic valve and the hydraulic pressure adjusted by the adjusting mechanism;
A second solenoid valve that changes a gear ratio by controlling the hydraulic pressure adjusted by the adjusting mechanism;
Means for detecting information relating to the hydraulic pressure supplied from the second solenoid valve;
And a control means for controlling the first electromagnetic valve based on information relating to the hydraulic pressure supplied from the second electromagnetic valve. The control valve increases the clamping pressure of the belt when the hydraulic pressure supplied from the adjustment mechanism decreases, and reduces the clamping pressure of the belt when the hydraulic pressure supplied from the first electromagnetic valve decreases. And
2. The belt-type device according to claim 1, wherein the control means includes means for reducing the hydraulic pressure supplied from the first electromagnetic valve when the hydraulic pressure supplied from the second electromagnetic valve increases. Hydraulic control device for step transmission.   The belt-type continuously variable control according to claim 2, wherein the control means includes means for lowering the hydraulic pressure supplied from the first electromagnetic valve as the hydraulic pressure supplied from the second electromagnetic valve increases. Hydraulic control device for transmission. The hydraulic control device further includes means for detecting the temperature of the hydraulic oil,
2. The control means according to claim 1, wherein the control means includes means for controlling the first electromagnetic valve based on a temperature of the hydraulic oil in addition to information on the hydraulic pressure supplied from the second electromagnetic valve. Hydraulic control device for belt type continuously variable transmission. The control valve increases the clamping pressure of the belt when the hydraulic pressure supplied from the adjustment mechanism decreases, and reduces the clamping pressure of the belt when the hydraulic pressure supplied from the first electromagnetic valve decreases. And
The hydraulic control device for a belt-type continuously variable transmission according to claim 4, wherein the control means includes means for lowering the hydraulic pressure supplied from the first electromagnetic valve as the temperature of the hydraulic oil is higher. . The hydraulic control device further includes means for detecting information related to hydraulic pressure supplied from a hydraulic pressure source,
The control means includes means for controlling the first electromagnetic valve based on information on the hydraulic pressure supplied from the hydraulic source in addition to information on the hydraulic pressure supplied from the second electromagnetic valve. The hydraulic control device for a belt-type continuously variable transmission according to claim 1. The control valve increases the clamping pressure of the belt when the hydraulic pressure supplied from the adjustment mechanism decreases, and reduces the clamping pressure of the belt when the hydraulic pressure supplied from the first electromagnetic valve decreases. And
The belt-type continuously variable transmission according to claim 6, wherein the control means includes means for lowering the hydraulic pressure supplied from the first electromagnetic valve as the hydraulic pressure supplied from the hydraulic source is smaller. Hydraulic control device.

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