JP2005350017A - Vehicle controller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle controller which controls an engine properly to suppress a slip of a crutch upon restoration of an engine torque. <P>SOLUTION: According to the vehicle controller, an ECU executes a program which includes a step (S108) of controlling a hydraulic control circuit in a clutch direct pressure mode for controlling an engaging pressure of a forward clutch, using a linear solenoid (SLS), when a garage shift is executed (YES at S106) while a vehicle is running (YES at S102), a step (S118) of lowering an engine torque when a gear ratio GR is equal to or less than a preset gear ratio GR (0), and a step (S112) of controlling returning of the engine torque when the clutch direct pressure mode is over (YES at S120). <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a vehicle control device, and more particularly to a vehicle control device equipped with a belt type continuously variable transmission.

  2. Description of the Related Art Conventionally, a belt type continuously variable transmission that performs a stepless change by connecting a primary pulley and a secondary pulley with a metal belt and changing the width of these pulleys is known. Some vehicles equipped with this belt-type continuously variable transmission travel forward only when a forward clutch provided between the engine and the engine is engaged. When the shift lever is in the non-traveling position (for example, “N” position), the hydraulic pressure is drained and the forward clutch is released. When the shift lever is in the traveling position (for example, “D” position), the hydraulic pressure is supplied to the forward clutch. As a result, the forward clutch is engaged. If the forward clutch suddenly changes from the disengaged state to the engaged state during traveling, a shock due to sudden engagement may occur. Therefore, when a garage shift is performed in which the shift lever is switched from the non-travel position to the travel position during travel, it is necessary to suppress sudden engagement of the forward clutch.

  Japanese Patent Laid-Open No. 2004-84831 (Patent Document 1) uses a linear solenoid valve (valve) that controls the belt clamping pressure of a secondary pulley to control the engagement pressure of a forward clutch (forward clutch) during a garage shift. A hydraulic control circuit is disclosed. The hydraulic control circuit described in Patent Document 1 includes a linear solenoid valve SLS, a clamping pressure control valve that controls the belt clamping pressure in accordance with the output hydraulic pressure of the linear solenoid valve SLS, and the output hydraulic pressure of the linear solenoid valve SLS as a pilot pressure. The garage shift valve control valve that outputs the garage shift hydraulic pressure, and the garage shift hydraulic pressure PG output from the garage shift control valve is output to the manual valve by stopping the output of the signal pressure of the solenoid valve SL during the garage shift. And a garage shift valve.

  According to the hydraulic control circuit described in this publication, at the time of a garage shift, the garage shift hydraulic pressure is supplied to the forward clutch via the garage shift valve and the manual valve, thereby smoothly engaging the forward clutch. The shock at the time can be suppressed.

  On the other hand, in the belt-type continuously variable transmission, the driving force from the engine is transmitted to the wheels by the frictional force between the pulley and the belt, so that the transmission efficiency is lowered as the belt slips. Therefore, it is necessary to suppress the belt slip.

  Japanese Patent Laying-Open No. 2004-92555 (Patent Document 2) discloses a belt slip prevention system capable of suppressing belt slip during a garage shift. The belt slip prevention system described in Patent Document 2 is traveling when the vehicle speed detecting means for detecting the speed of the vehicle, the shift lever for instructing the traveling direction of the vehicle, and the vehicle speed detected by the vehicle speed detecting means exceed a predetermined value. In addition, when it is determined that the shift selector has been sequentially selected as the forward range (position), the neutral range, and the forward range, the DND select determination means and the range selection by the DND selection determination means are performed. Engine output limiting means for limiting the output and preventing belt slippage. The engine output limiting means limits the engine output for a predetermined time from the time when the shift lever is selected from the neutral range to the forward range, and releases the engine output limitation after the time has elapsed.

According to the belt slip prevention system described in this publication, the engine output is limited when the shift lever is sequentially selected from the forward range, the neutral range, and the forward range during traveling at a predetermined vehicle speed or higher. As a result, belt slippage can be prevented.
JP 2004-84831 A JP 2004-92555 A

  In the belt type continuously variable transmission, the belt clamping pressure is controlled to be equal to or less than a guard value from the viewpoint of protection of the belt. The guard value is set smaller as the gear ratio becomes smaller. That is, the guard value is set to be smaller as the belt diameter of the secondary pulley is smaller and the load on the belt is larger. Therefore, if the engagement pressure of the forward clutch is controlled using a solenoid valve that controls the belt clamping pressure as in the hydraulic control circuit described in Patent Document 1, the engagement pressure may be insufficient. When the engagement pressure is insufficient, the forward clutch is not sufficiently engaged. For this reason, when the engagement pressure control is finished in this state, the forward clutch is suddenly engaged, and a shock may occur. Further, due to the sudden engagement of the forward clutch, the driving force from the engine is suddenly input to the belt, and the belt may slip.

  In order to suppress the occurrence of such shock and belt slip, it is conceivable to limit the engine output during garage shift as in the belt slip prevention system described in Patent Document 2. However, the belt slip prevention system described in Patent Document 2 releases the engine output restriction after a predetermined time has elapsed since the shift lever was selected from the neutral position to the forward position. Therefore, there is a problem that the output restriction may be released at an inappropriate time. For example, when the engine output is restored in a state where the engagement of the forward clutch is insufficient, the forward clutch slips and the forward clutch cannot be engaged reliably.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a vehicle control device that can appropriately control the output of a power source such as an engine.

  A vehicle control device according to a first aspect of the present invention is a vehicle control device equipped with a belt type continuously variable transmission connected to a power source via a friction engagement element. The frictional engagement element is brought into engagement during advance. The control device corresponds to a garage shift that is switched from the non-travel position to the travel position, and an engagement pressure control means for controlling the engagement pressure of the friction engagement element, and an output corresponding to the garage shift. And output control means for controlling the power source so as to reduce the power source. The output control means includes means for controlling the power source so as to end the output reduction of the power source in response to the end of the engagement pressure control of the friction engagement element by the engagement pressure control means.

  According to the first invention, the engagement pressure control means controls the engagement pressure of the friction engagement element in response to a garage shift that is switched from the non-travel position to the travel position. For example, if the control of the engagement pressure is stopped in a state where the engagement pressure is not sufficient, the friction engagement element may be suddenly engaged and a shock may occur. In addition, the driving force from the engine is suddenly input to the belt due to the sudden engagement, and the belt may slip. Therefore, the power source is controlled by the output control means so as to reduce the output in response to the garage shift. Thereby, generation | occurrence | production of a shock and belt slip can be suppressed. The output control means controls the power source so as to end the output reduction of the power source in response to the end of the engagement pressure control of the friction engagement element by the engagement pressure control means. As a result, the engagement pressure control can be finished with the output of the power source lowered, and the output of the power source can be returned with the friction engagement element fully engaged. Therefore, the frictional engagement element can be prevented from slipping when the output of the power source is restored, and the frictional engagement element can be sufficiently engaged. As a result, it is possible to provide a vehicle control device that can appropriately control the output of the power source.

  In the vehicle control apparatus according to the second invention, in addition to the configuration of the first invention, the control apparatus further includes a clamping pressure control means for controlling the belt clamping pressure of the belt-type continuously variable transmission. The engagement pressure control means includes means for controlling the engagement pressure of the friction engagement element in response to the garage shift by being controlled by the clamping pressure control means.

  According to the second invention, the clamping pressure control means controls the belt clamping pressure, and the engagement pressure control means is controlled by the clamping pressure control means. Thereby, the engagement pressure of the friction engagement element can be controlled using the clamping pressure control means. In this state, for example, during traveling with a low gear ratio, if the guard value of the belt clamping pressure is small, the engagement pressure of the friction engagement element may not be sufficient. If the control of the engagement pressure is stopped in a state where the engagement pressure is not sufficient, the friction engagement element is suddenly engaged, and a shock may occur. In addition, the driving force from the engine is suddenly input to the belt due to the sudden engagement, and the belt may slip. Therefore, the power source is controlled by the output control means so as to reduce the output in response to the garage shift. Thereby, generation | occurrence | production of a shock and belt slip can be suppressed. The output control means controls the power source so as to end the output reduction of the power source in response to the end of the engagement pressure control of the friction engagement element by the engagement pressure control means. As a result, the engagement pressure control can be finished with the output of the power source lowered, and the output of the power source can be returned with the friction engagement element fully engaged. Therefore, the frictional engagement element can be prevented from slipping when the output of the power source is restored, and the frictional engagement element can be sufficiently engaged. As a result, it is possible to provide a vehicle control device that can appropriately control the output of the power source.

  In the vehicle control device according to the third aspect of the invention, in addition to the configuration of the second aspect of the invention, the control device further includes means for detecting the gear ratio of the belt type continuously variable transmission. The output control means includes means for controlling the power source so as to reduce the output when the speed ratio of the belt type continuously variable transmission is equal to or less than a predetermined speed ratio.

  According to the third aspect of the invention, the speed ratio of the belt type continuously variable transmission is detected, and when the speed ratio is less than or equal to a predetermined speed ratio, the power reduction is controlled to reduce the output. Thus, it is possible to suppress shock and belt slip when the friction engagement element is engaged from a state where the engagement pressure is not sufficient because the guard value of the belt clamping pressure is small, for example, in a state where the gear ratio is low.

  In the vehicle control apparatus according to the fourth aspect of the invention, in addition to the configuration of any one of the first to third aspects, the output control means responds when the engagement pressure control of the frictional engagement element by the engagement pressure control means ends. And means for controlling the power source to gradually change the output.

  According to a fourth aspect of the invention, the power source is controlled so that the output control means gradually changes the output in response to the end of the engagement pressure control of the friction engagement element by the engagement pressure control means. . Thereby, it is possible to suppress a sudden change in the driving force transmitted from the power source to the belt type continuously variable transmission.

  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.

  A vehicle equipped with a control device according to the present embodiment will be described with reference to FIG. The output of the engine 200 of the drive device 100 mounted on the vehicle is input to the belt type continuously variable transmission 500 via the torque converter 300 and the forward / reverse switching device 400. The output of the belt type continuously variable transmission 500 is transmitted to the reduction gear 600 and the differential gear device 700, and is distributed to the left and right drive wheels 800. The driving device 100 is controlled by an ECU (Electronic Control Unit) 900 described later. The control device according to the present embodiment is realized by a program executed by ECU 900, for example.

  The torque converter 300 includes a pump impeller 302 connected to the crankshaft of the engine 200 and a turbine impeller 306 connected to the forward / reverse switching device 400 via the turbine shaft 304. A lockup clutch 308 is provided between the pump impeller 302 and the turbine impeller 306. The lockup clutch 308 is engaged or released when the hydraulic pressure supply to the engagement side oil chamber and the release side oil chamber is switched.

  When the lockup clutch 308 is completely engaged, the pump impeller 302 and the turbine impeller 306 are integrally rotated. The pump impeller 302 includes a mechanical oil pump 310 that generates a hydraulic pressure for controlling the shift of the belt type continuously variable transmission 500, generating a belt clamping pressure, and supplying lubricating oil to each part. Is provided.

  The forward / reverse switching device 400 is composed of a double pinion type planetary gear device. Turbine shaft 304 of torque converter 300 is connected to sun gear 402. The input shaft 502 of the belt type continuously variable transmission 500 is connected to the carrier 404. Carrier 404 and sun gear 402 are connected via forward clutch 406. Ring gear 408 is fixed to the housing via reverse brake 410. The forward clutch 406 and the reverse brake 410 are frictionally engaged by a hydraulic cylinder.

  When the forward clutch 406 is engaged and the reverse brake 410 is released, the forward / reverse switching device 400 enters the forward connection state. In this state, the driving force in the forward direction is transmitted to the belt type continuously variable transmission 500. When the reverse brake 410 is engaged and the forward clutch 406 is released, the forward / reverse switching device 400 enters the reverse connection state. In this state, the input shaft 502 is rotated in the reverse direction with respect to the turbine shaft 304. As a result, the driving force in the reverse direction is transmitted to the belt type continuously variable transmission 500. When both forward clutch 406 and reverse brake 410 are released, forward / reverse switching device 400 enters a neutral state in which power transmission is interrupted.

  The belt type continuously variable transmission 500 includes a primary pulley 504 provided on the input shaft 502, a secondary pulley 508 provided on the output shaft 506, and a transmission belt 510 wound around these pulleys. Power is transmitted using frictional forces between the pulleys and the transmission belt 510.

  Each pulley is composed of a hydraulic cylinder so that the groove width is variable. By controlling the hydraulic pressure of the hydraulic cylinder of the primary pulley 504, the groove width of each pulley changes. As a result, the engagement diameter of the transmission belt 510 is changed, and the gear ratio GR (= primary pulley rotation speed NIN / secondary pulley rotation speed NOUT) is continuously changed.

  As shown in FIG. 2, the ECU 900 includes an engine speed sensor 902, a turbine speed sensor 904, a vehicle speed sensor 906, a throttle sensor 908, a coolant temperature sensor 910, an oil temperature sensor 912, an accelerator opening sensor 914, and a foot brake switch. 916, a position sensor 918, a primary pulley rotation speed sensor 922, and a secondary pulley rotation speed sensor 924 are connected.

  The engine speed sensor 902 detects the engine speed (engine speed) NE of the engine 200. The turbine rotation speed sensor 904 detects the rotation speed (turbine rotation speed) NT of the turbine shaft 304. The vehicle speed sensor 906 detects the vehicle speed V. The throttle opening sensor 908 detects the opening degree θ (TH) of the electronic throttle valve. Cooling water temperature sensor 910 detects cooling water temperature T (W) of engine 200. The oil temperature sensor 912 detects the oil temperature T (C) of the belt type continuously variable transmission 500 or the like. The accelerator opening sensor 914 detects the accelerator pedal opening A (CC). The foot brake switch 916 detects whether or not the foot brake is operated. The position sensor 918 detects the position P (SH) of the shift lever 920. Primary pulley rotation speed sensor 922 detects the rotation speed NIN of primary pulley 504. Secondary pulley rotation speed sensor 924 detects rotation speed NOUT of secondary pulley 508. A signal representing the detection result of each sensor is transmitted to ECU 900. The turbine rotational speed NT coincides with the primary pulley rotational speed NIN during forward traveling with the forward clutch 406 engaged. The vehicle speed V becomes a value corresponding to the secondary pulley rotation speed NOUT.

  ECU 900 includes a CPU (Central Processing Unit), a memory, an input / output interface, and the like. The CPU performs signal processing according to a program stored in the memory. Thereby, output control of the engine 200, shift control of the belt-type continuously variable transmission 500, belt clamping pressure control, engagement / release control of the forward clutch 406, engagement / release control of the reverse brake 410, and the like are executed.

  Output control of the engine 200 is performed by an electronic throttle valve 1000, a fuel injection device 1100, an ignition device 1200, and the like. The hydraulic control circuit 1300 performs shift control of the belt-type continuously variable transmission 500, belt clamping pressure control, engagement / release control of the forward clutch 406, and engagement / release control of the reverse brake 410.

  A part of the hydraulic control circuit 1300 will be described with reference to FIG. The hydraulic control circuit 1300 includes a manual valve 1310, a clamping pressure control valve 1320, a garage shift control valve 1330, a garage shift valve 1340, a modulator valve 1350, a linear solenoid valve (SLS) 1360, and a solenoid valve (SL) 1370. .

  Manual valve 1310 is mechanically switched according to the operation of shift lever 920. Thereby, the forward clutch 406 and the reverse brake 410 are engaged or released.

  The shift lever 920 is operated to the “P” position for parking, the “R” position for reverse travel, the “N” position for interrupting power transmission, the “D” position and “L” position for forward travel.

  In the “P” position and the “N” position, the hydraulic pressure in the forward clutch 406 and the reverse brake 410 is drained from the manual valve 120. Thereby, the forward clutch 406 and the reverse brake 410 are released.

  In the “R” position, hydraulic pressure is supplied from the manual valve 1310 to the reverse brake 410. Thereby, the reverse brake 410 is engaged. On the other hand, the hydraulic pressure in the forward clutch 406 is drained from the manual valve 120. As a result, the forward clutch 406 is released.

  In the “D” position and the “L” position, the hydraulic pressure is supplied from the manual valve 120 to the forward clutch 406. As a result, the forward clutch 406 is engaged. On the other hand, the hydraulic pressure in the reverse brake 410 is drained from the manual valve 120. Thereby, the reverse brake 410 is released.

  The hydraulic pressure of the hydraulic cylinder of the secondary pulley 508 is controlled by the clamping pressure control valve 1320 so that the transmission belt 510 does not slip. The clamping pressure control valve 1320 is provided with a spool 1322 that can move in the axial direction and a spring 1324 that biases the spool 1322 to one side. The clamping pressure control valve 1320 regulates the line pressure PL introduced into the clamping pressure control valve 1320 using the output hydraulic pressure of the linear solenoid valve (SLS) 1360 duty controlled by the ECU 900 as a pilot pressure, and the hydraulic cylinder of the secondary pulley 508 To supply. The belt clamping pressure is increased or decreased according to the hydraulic pressure output from the clamping pressure control valve 1320.

  The garage shift control valve 1330 is provided with a spool 1332 that is movable in the axial direction and a spring 1334 that biases the spool 1332 to one side. Garage shift control valve 1330 controls modulator pressure PM using the output hydraulic pressure of linear solenoid valve (SLS) 1360 duty-controlled by ECU 900 as a pilot pressure. Thereby, the garage shift control valve 1330 outputs the garage shift pressure PG.

  Garage shift pressure PG is supplied to forward clutch 406 via garage shift valve 1340 and manual valve 1310. As a result, the forward clutch 406 is smoothly engaged during a garage shift in which the shift lever 920 is operated from the “N” position to the “D” position, and a shock at the time of engagement is suppressed.

  The garage shift valve 1340 is provided with a spool 1342 that is movable in the axial direction and a spring 1344 that biases the spool 1342 to one side. The garage shift valve 1340 is normally held in the OFF state shown in the right half in FIG. 3 by the signal pressure of the solenoid valve (SL) 1370 controlled to be opened and closed by the ECU 900. In this state, the garage shift valve 1340 outputs the modulator pressure PM to the manual valve 1310 as it is. The reverse brake 410 and the forward clutch 406 are held in the engaged state by the modulator pressure PM.

  At the time of the garage shift, the solenoid of the solenoid valve (SL) 1370 is excited and the output of the signal pressure is stopped, so that the ON state shown in the left half in FIG. In this state, the garage shift valve 1340 outputs the garage shift pressure PG output from the garage shift control valve 1330 to the manual valve 120.

  The linear solenoid valve (SLS) 1360 normally controls the belt clamping pressure via the clamping pressure control valve 1320 (belt clamping pressure mode). On the other hand, during the garage shift, the linear solenoid valve (SLS) 1360 controls the garage shift pressure PG of the forward clutch 406 (clutch direct pressure mode).

  As shown in FIG. 4, ECU 900 controls linear solenoid valve (SLS) 1360 and solenoid valve (SL) 1370 using clamping pressure control unit 930 and engagement transient hydraulic pressure control unit 932. Thereby, the ECU 900 controls the hydraulic control circuit 1300 in one of the belt clamping pressure mode and the clutch direct pressure mode.

  In the belt clamping mode, the linear solenoid valve (SLS) controls the clamping pressure control unit 930 so that the belt clamping pressure does not cause belt slip according to the map using the accelerator opening A (CC) and the gear ratio GR as parameters. 1360 is controlled. Specifically, the exciting current for the linear solenoid valve (SLS) 1360 is controlled with a duty ratio corresponding to the belt clamping pressure. When the transmission torque changes suddenly during acceleration / deceleration or the like, belt slippage may be suppressed by increasing the belt clamping pressure.

  As shown in FIG. 5, the belt clamping pressure has a guard value (upper limit value) for protecting the transmission belt 510. The clamping pressure control unit 930 controls the linear solenoid valve (SLS) 1360 so that the belt clamping pressure is equal to or less than the guard value. The smaller the gear ratio, the smaller the engagement diameter of the transmission belt 510 in the secondary pulley 508 and the greater the load on the transmission belt 510. For this reason, the guard value of the belt clamping pressure is smaller as the gear ratio is smaller.

  In the clutch direct pressure mode, the engagement transient hydraulic pressure control unit 932 excites the solenoid valve (SL) 1370 to output a signal pressure when the shift lever 920 is operated from the “N” position to the “D” position. To stop. Thereby, the garage shift valve 1340 is turned on. In addition, the engagement transient hydraulic pressure control unit 932 controls the linear solenoid valve (SLS) 1360 so that a desired garage shift pressure PG is obtained during the garage shift. Specifically, the duty ratio of linear solenoid valve (SLS) 1360 is controlled according to a predetermined control pattern so that forward clutch 406 is smoothly engaged. The control pattern is, for example, a pattern in which the piston is quickly moved to a position immediately before the forward clutch 406 generates the engagement force, and then the hydraulic pressure is gradually increased to gradually increase the engagement force of the forward clutch 406.

  Even in the clutch direct pressure mode, the output hydraulic pressure of the linear solenoid valve (SLS) 1360 is supplied to the clamping pressure control valve 1320. Therefore, the engagement transient hydraulic pressure control unit 932 controls the linear solenoid valve (SLS) 1360 so that the belt clamping pressure is equal to or less than the guard value, similarly to the clamping pressure control unit 930.

  With reference to FIG. 6, a control structure of a program executed by ECU 900 of the control device according to the present embodiment will be described.

  In step (hereinafter, step is abbreviated as S) 100, ECU 900 detects the vehicle speed based on the signal transmitted from vehicle speed sensor 906. In S102, ECU 900 determines whether or not the vehicle is traveling. Whether or not the vehicle is running may be determined based on whether or not the vehicle speed is greater than 0, for example. If the vehicle is traveling (YES in S102), the process proceeds to S104. If not (NO in S102), this process ends.

  In S104, ECU 900 detects position P (SH) of shift lever 920 based on the signal transmitted from position sensor 918. In S106, ECU 900 determines whether or not a garage shift has been performed. Whether or not the garage shift has been performed may be determined based on, for example, whether or not the shift lever 920 has been operated from the “N” position to the “D” position. If a garage shift has been performed (YES in S106), the process proceeds to S108. If not (NO in S106), this process ends. In S108, ECU 900 controls hydraulic control circuit 1300 in the clutch direct pressure mode.

  In S110, ECU 900 detects primary pulley rotation speed NIN based on the signal transmitted from primary pulley rotation speed sensor 922. In S112, ECU 900 detects secondary pulley rotation speed NOUT based on the signal transmitted from secondary pulley rotation speed sensor 924.

  In S114, ECU 900 detects gear ratio GR from primary pulley rotation speed NIN and secondary pulley rotation speed NOUT. In S116, ECU 900 determines whether or not gear ratio GR is equal to or smaller than a predetermined gear ratio GR (0). If gear ratio GR is equal to or smaller than a predetermined gear ratio GR (0) (YES in S116), the process proceeds to S118. If not (NO in S116), the process proceeds to S124.

  In S118, ECU 900 decreases the torque (engine output) of engine 200. In S120, ECU 900 determines whether or not the clutch direct pressure mode has ended. Whether or not the clutch direct pressure mode has ended may be determined, for example, based on whether or not the turbine rotational speed NT and the primary pulley rotational speed NIN match. If the clutch direct pressure mode has ended (YES in S120), the process proceeds to S122. If not (NO in S120), the process proceeds to S120.

  In S122, ECU 900 executes engine torque return control. In the engine torque return control, the engine 200 is controlled so that the engine torque is gradually increased (gradual change).

  In S124, ECU 900 determines whether or not the clutch direct pressure mode has ended. If the clutch direct pressure mode has ended (YES in S124), this process ends. If not (NO in S124), the process proceeds to S124.

  An operation of ECU 900 of the control device according to the present embodiment based on the above-described structure and flowchart will be described.

  If the vehicle speed is detected (S100) and the vehicle is traveling (YES in S102), position P (SH) of shift lever 920 is detected (S104). When the garage shift is performed (YES in S106), hydraulic control circuit 1300 is controlled in the clutch direct pressure mode.

  In this state, the primary pulley rotation speed NIN is detected (S110), and the secondary pulley rotation speed NOUT is detected (S112). Based on these rotational speeds, the gear ratio GR is detected (S114).

  In the clutch direct pressure mode, the engagement pressure of the forward clutch 406 is controlled by a linear solenoid valve (SLS) 1360. Even in the clutch direct pressure mode, the linear solenoid valve (SLS) 1360 is controlled so that the belt clamping pressure is equal to or less than the guard value. For this reason, as the gear ratio is smaller, the guard value becomes smaller, so that the engagement pressure of the forward clutch 406 may be suppressed and the engagement may be insufficient.

  When the clutch direct pressure mode is terminated while the forward clutch 406 is not sufficiently engaged, the forward clutch 406 may be suddenly engaged and a shock may occur. Further, the driving force from the engine 200 is suddenly input to the transmission belt 510, and there is a possibility that the belt slips.

  Therefore, if gear ratio GR is equal to or smaller than a predetermined gear ratio GR (0) (YES in S116), torque of engine 200 is reduced (S118). That is, when the vehicle speed is high and the vehicle can be driven even when the torque is low, the torque of engine 200 is reduced. Thereby, generation | occurrence | production of a shock and belt slip are suppressed.

  When the clutch direct pressure mode is ended (YES in S120), the modulator pressure output from modulator valve 122 is supplied to forward clutch 406 as it is without passing through garage shift control valve 1330. Thereby, the engagement pressure of the forward clutch 406 becomes sufficiently large. Therefore, the forward clutch 406 is sufficiently engaged.

  In this state, engine torque return control is executed (S122), and the engine torque is gradually increased. As a result, the engine torque can be restored with the forward clutch 406 fully engaged, the forward clutch 406 can be prevented from slipping when the engine torque is restored, and the forward clutch 406 can be engaged. Further, since the engine torque is increased gradually, it is possible to suppress a shock when the engine torque is restored.

  As described above, when the garage shift is performed during traveling, the ECU of the control device according to the present embodiment uses the linear solenoid valve (SLS) to change the engagement pressure of the forward clutch to the clutch direct pressure mode. To control. In the clutch direct pressure mode, if the gear ratio GR is smaller than a predetermined gear ratio GR (0), the engine torque is reduced. Thereby, it is possible to suppress the occurrence of a shock and the slippage of the transmission belt when the clutch direct pressure mode is ended in a state where the engagement pressure of the forward clutch is insufficient. When the clutch direct pressure mode ends, the engine torque is restored. As a result, the engine torque can be restored with the forward clutch engaged sufficiently. Therefore, the slippage of the forward clutch when the engine torque is restored can be suppressed.

  In addition, when operated from the “N” position to the “R” position, or when operated from the “P” position to the “R” position, the engagement pressure of the forward clutch is used as a linear solenoid valve (SLS). You may make it control. Further, the belt clamping pressure may be controlled by a plurality of linear solenoid valves, and the engagement pressure of the forward clutch may be controlled using these linear solenoid valves.

  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.

It is a skeleton figure of the vehicle carrying the control device concerning an embodiment of the invention. It is a control block diagram which shows the control apparatus which concerns on embodiment of this invention. It is a figure which shows the hydraulic control circuit controlled by the control apparatus which concerns on this Embodiment. It is a control block diagram which shows ECU of the control apparatus which concerns on embodiment of this invention. It is a figure which shows the guard value of belt clamping pressure. It is a flowchart which shows the control structure of the program which ECU of the control apparatus which concerns on embodiment of this invention performs.

Explanation of symbols

  200 engine, 400 forward / reverse switching device, 402 sun gear, 404 carrier, 406 forward clutch, 408 ring gear, 410 reverse brake, 500 belt type continuously variable transmission, 504 primary pulley, 508 secondary pulley, 510 transmission belt, 900 ECU, 904 Turbine rotational speed sensor, 920 shift lever, 922 primary pulley rotational speed sensor, 924 secondary pulley rotational speed sensor, 930 clamping pressure control unit, 932 engagement transient hydraulic control unit, 1000 electronic throttle valve, 1100 fuel injection device, 1200 ignition device 1300 Hydraulic control circuit, 1320 Nipping pressure control valve, 1330 Garage shift control valve, 1340 Garage shift valve, 1350 Modulator valve 1360 Linear solenoid valve (SLS), 1370 Solenoid valve (SL).

Claims (4)

A control device for a vehicle equipped with a belt-type continuously variable transmission connected to a power source via a frictional engagement element, wherein the frictional engagement element is brought into an engaged state when moving forward,
Engagement pressure control means for controlling the engagement pressure of the friction engagement element in response to a garage shift that is switched from the non-travel position to the travel position;
Output control means for controlling the power source to reduce the output in response to the garage shift,
The output control means includes means for controlling the power source so as to end the output reduction of the power source in response to completion of engagement pressure control of the friction engagement element by the engagement pressure control means. Vehicle control device. The control device further includes a clamping pressure control means for controlling a belt clamping pressure of the belt-type continuously variable transmission,
The engagement pressure control means includes means for controlling an engagement pressure of the friction engagement element in response to the garage shift by being controlled by the clamping pressure control means. The vehicle control device described. The control device further includes means for detecting a gear ratio of the belt type continuously variable transmission,
The output control means includes means for controlling the power source so as to reduce the output when a speed ratio of the belt-type continuously variable transmission is equal to or lower than a predetermined speed ratio. The vehicle control device described in 1.   The output control means includes means for controlling the power source so as to gradually change the output in response to completion of engagement pressure control of the friction engagement element by the engagement pressure control means. The control apparatus of the vehicle in any one of 1-3.

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