JP4433928B2 - Control device for automatic transmission - Google Patents

Description

  The present invention relates to an automatic transmission control device, and more particularly to an automatic transmission control device equipped with a power transmission device connected to a power source through a friction engagement element.

  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, a clamping pressure control valve that controls the belt clamping pressure according to the output hydraulic pressure of the linear solenoid valve, and a garage shift using the output hydraulic pressure of the linear solenoid valve as a pilot pressure. A garage shift valve control valve that outputs hydraulic pressure, and a garage shift valve that outputs the garage shift hydraulic pressure PG output from the garage shift control valve to the manual valve by stopping the output of the signal pressure of the solenoid valve during garage shift Including. When the shift lever is in the “N” position, the duty ratio (clutch command pressure) of the excitation current for the linear solenoid valve is maintained at a predetermined value. When the garage shift is performed, the duty ratio is set to a higher value than when the shift lever is in the “N” position. After the duty ratio is increased only for a predetermined period, the duty ratio is once decreased. Thereafter, the duty ratio is gradually increased.

According to the hydraulic control circuit described in this publication, at the time of a garage shift, the garage shift valve is turned on by exciting the solenoid valve and stopping the output of the signal pressure. Thereby, the garage shift hydraulic pressure PG is supplied from the garage shift control valve to the forward clutch via the garage shift valve and the manual valve. During the garage shift, the duty ratio of the linear solenoid valve is increased. As a result, the garage shift hydraulic pressure PG is increased, and the piston is quickly moved to a position immediately before the forward clutch generates engagement torque. Thereafter, the duty ratio is once lowered and then gradually increased. Thereby, the garage shift hydraulic pressure PG can be gradually increased, the forward clutch can be smoothly engaged, and a shock at the time of engagement can be suppressed.
JP 2004-84831 A

  By the way, when the oil temperature of the hydraulic oil is low, the viscosity of the hydraulic oil is high, resulting in poor responsiveness. Therefore, in order to improve responsiveness at low temperatures, the clutch command pressure (the duty ratio of the linear solenoid valve) when the shift lever is in the “N” position is higher than that at room temperature, as shown by the one-dot chain line in FIG. It is possible to do.

  Here, it is assumed that the shift lever is slowly operated from the “N” position to the “D” position. At time T (A) when the shift lever starts to be operated from the “N” position to the “D” position, the garage shift hydraulic pressure PG starts to be supplied from the garage shift control valve to the forward clutch via the garage shift valve and the manual valve. .

  Therefore, before the shift lever is detected to be in the “D” position by the position sensor, that is, before the shift lever is positioned in the “D” position, the forward clutch is engaged at a high clutch command pressure P (B). There is a risk. Therefore, there is a problem that a shock accompanying the engagement of the forward clutch may occur.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a control device for an automatic transmission that can suppress the occurrence of a shock. Another object of the present invention is to provide a control device for an automatic transmission capable of engaging a friction engagement element (forward clutch) even when the position of a shift lever is not normally detected.

  A control device for an automatic transmission according to a first aspect of the present invention is a control device for an automatic transmission that includes a power transmission device connected to a power source via a friction engagement element. The friction engagement elements are engaged by being supplied with hydraulic pressure. The control device adjusts the pressure control valve that adjusts the hydraulic pressure generated by the hydraulic pressure source with the control pressure from the solenoid valve, and the communication of the hydraulic passage that supplies the hydraulic pressure from the pressure adjustment valve to the friction engagement element and shuts off the position of the shift lever A switching valve that switches in conjunction, a detecting means for detecting the position of the shift lever, and a control means for controlling the solenoid valve so as to regulate the hydraulic pressure by the pressure regulating valve in accordance with the shift operation of the driver; including. The control means, when it is detected that the shift lever is in a position corresponding to the non-traveling position, means for controlling the solenoid valve so as to regulate the hydraulic pressure to the first hydraulic pressure by the pressure regulating valve, and the shift lever The pressure from the hydraulic pressure source is lower than the first hydraulic pressure by the pressure regulating valve from when it is detected that it is not at the position corresponding to the non-traveling position to when it is detected as being at the position corresponding to the traveling position. Means for controlling the solenoid valve to regulate the second hydraulic pressure.

  According to the first invention, when it is detected that the shift lever is in a position corresponding to the non-traveling position, the pressure regulating valve causes the hydraulic pressure generated by the hydraulic pressure source to be controlled by the control pressure from the electromagnetic valve. Adjust pressure. The pressure regulator adjusts the hydraulic pressure generated by the hydraulic power source between the first time when it is detected that the shift lever is not at the position corresponding to the non-travel position and the time when the shift lever is detected at the position corresponding to the travel position. The pressure is adjusted to a second hydraulic pressure lower than the hydraulic pressure. As a result, the hydraulic pressure supplied to the friction engagement element via the switching valve before the shift lever is completely positioned at the travel position can be reduced. Therefore, a shock due to the engagement of the friction engagement element can be suppressed. As a result, it is possible to provide a control device for an automatic transmission that can suppress the occurrence of shock.

  In the automatic transmission control device according to the second invention, in addition to the configuration of the first invention, the switching valve shuts off the oil passage when the shift lever is in a position corresponding to the non-traveling position, and the shift lever When is at a position corresponding to the travel position, the oil passage is communicated.

  According to the second invention, when the shift lever is at a position corresponding to the non-traveling position, the supply of hydraulic pressure to the frictional engagement element can be shut off to suppress the occurrence of a shock.

  In the automatic transmission control device according to the third invention, in addition to the configuration of the first or second invention, the hydraulic control device detects that the shift lever is not in a position corresponding to the non-travel position, and the travel position. Further included is a means for measuring the elapsed time detected when it is not located at a position corresponding to. The control means includes means for controlling the electromagnetic valve so that the friction engagement element is engaged when the elapsed time exceeds a predetermined time.

  According to the third invention, when the elapsed time detected that the shift lever is not in the position corresponding to the non-travel position and not in the position corresponding to the travel position exceeds a predetermined time, The friction engagement element is engaged. Thereby, even if it is not detected that the shift lever is in a position corresponding to the travel position, the friction engagement element can be brought into the engaged state. Therefore, the friction engagement element can be engaged when the shift lever is actually in a position corresponding to the travel position and cannot be detected due to an abnormality in the detection means. As a result, it is possible to provide a control device for an automatic transmission that can bring the friction engagement element into an engaged state even when the position of the shift lever is not normally detected.

  In the automatic transmission control device according to the fourth invention, in addition to the configuration of any one of the first to third inventions, the hydraulic control device determines whether or not the friction engagement element is in an engaged state. Means for further including. When it is determined that the shift lever is not in a position corresponding to the non-traveling position and the friction engagement element is determined to be engaged, the control means changes the hydraulic pressure to the first hydraulic pressure by the pressure regulating valve. Means for controlling the solenoid valve to regulate pressure are included.

  According to the fourth invention, when the friction engagement element is engaged, the hydraulic pressure is regulated to the first hydraulic pressure even if it is detected that the shift lever is not in a position corresponding to the non-traveling position. Accordingly, it is possible to suppress the hydraulic pressure from being lowered to the second hydraulic pressure in a state where the friction engagement elements are engaged. Therefore, it is possible to prevent the frictional engagement element from slipping due to a decrease in hydraulic pressure and causing a shock.

  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 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. In the present embodiment, belt-type continuously variable transmission 500 is used as the automatic transmission, but an automatic transmission having a gear train composed of a planetary gear device may be used. Moreover, a toroidal continuously variable transmission may be used.

  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. The input rotational speed of the forward clutch 406 is the same as the rotational speed of the turbine shaft 304, that is, the turbine rotational speed NT.

  When the forward clutch 406 is engaged and the reverse brake 410 is released, the forward / reverse switching device 400 enters the forward engagement 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 engagement 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 by determining whether the contact provided at the position corresponding to the shift position is ON or OFF. 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. Therefore, when the vehicle is stopped and the forward clutch 406 is engaged, the turbine speed NT is zero.

  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.

  Shift lever 920 is operated to a “P” position for parking, an “R” position for reverse travel, an “N” position for interrupting power transmission, a “D” position and “B” 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 1310. 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 1310. As a result, the forward clutch 406 is released.

  In the “D” position and the “B” position, the hydraulic pressure is supplied from the manual valve 1310 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 1310. 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 or the “R 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 1310.

  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, at the time of garage shift, the linear solenoid valve (SLS) 1360 controls the garage shift pressure PG of the forward clutch 406 (clutch direct pressure mode, garage shift control).

  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.

  The belt clamping pressure has a guard value (upper limit) 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 during a garage shift when the shift lever 920 is operated from the “N” position to the “D” position or the “R” position. Stop signal pressure output. Thereby, the garage shift valve 1340 is turned on. In addition, the engagement transient hydraulic pressure control unit 932 controls the duty ratio of the linear solenoid valve (SLS) 1360 so that a desired garage shift pressure PG is obtained during garage shift.

  In the clutch direct pressure mode at normal temperature, the command pressure of the ECU 900 related to the garage shift pressure PG (the hydraulic pressure supplied to the forward clutch 406) is the hydraulic pressure P (1 when the garage shift is performed as shown by the solid line in FIG. ) To the initial control pressure. As a result, the hydraulic oil of the forward clutch 406 in the released state is quickly filled with hydraulic oil. Thereafter, a constant pressure standby pressure lower than the initial control pressure is maintained, and the forward clutch 406 starts to be engaged with an engagement force corresponding to the constant pressure standby pressure. After the constant pressure standby pressure is maintained for a predetermined time, the command pressure is gradually increased with a predetermined gradient.

  When the vehicle is stopped, it can be said that the forward clutch 406 is completely engaged when the turbine speed is zero. In this case, the clutch direct pressure mode is terminated and the modulator pressure PM is supplied to the forward clutch 406.

  On the other hand, when the temperature is low, the viscosity of the hydraulic oil increases, and the responsiveness of the forward clutch 406 deteriorates. In order to improve responsiveness at low temperatures, the command pressure when the shift lever 920 is in the “N” position is set to a hydraulic pressure P (2) higher than the hydraulic pressure P (1) at normal temperature. The transition of the command pressure when the garage shift is performed at a low temperature will be described in detail later.

  With reference to FIG. 6, a control structure of a program executed by ECU 900 of the control device according to the present embodiment when hydraulic oil is at a low temperature will be described. Note that the program described below is repeatedly executed at a predetermined cycle.

  In step (hereinafter step is abbreviated as S) 100, ECU 900 determines whether or not all of the D contact, R contact and B contact of position sensor 918 are OFF based on the signal transmitted from position sensor 918. Is determined. That is, ECU 900 determines whether shift lever 920 is not in any of the “D” position, “R” position, and “B” position. If all of D contact, R contact, and B contact of position sensor 918 are OFF (YES in S100), the process proceeds to S102. If not (NO in S100), the process proceeds to S114.

  In S102, ECU 900 determines whether or not the N contact of position sensor 918 is ON based on the signal transmitted from position sensor 918. That is, ECU 900 determines whether or not shift lever 920 is in the “N” position. If the N contact of position sensor 918 is ON (YES in S102), the process proceeds to S116. If not (NO in S102), the process proceeds to S104.

  In S104, ECU 900 determines whether or not the N contact of position sensor 918 that was previously ON has changed to OFF based on the signal transmitted from position sensor 918. That is, ECU 900 determines whether or not shift lever 920 has been operated from the “N” position. If the N contact of position sensor 918 has changed from ON to OFF (YES in S104), the process proceeds to S106. If not (NO in S104), the process proceeds to S108.

  In S106, ECU 900 starts measuring the elapsed time after the N contact of position sensor 918 changes from ON to OFF. In S108, ECU 900 determines whether forward clutch 406 is in the released state or not. Whether or not forward clutch 406 is in the released state is determined based on turbine rotational speed NT and primary pulley rotational speed NIN. When | NT−NIN | ≧ K, it is determined that the forward clutch 406 is in the released state. Here, K is a predetermined number of rotations. If forward clutch 406 is disengaged (YES in S108), the process proceeds to S110. If not (NO in S108), the process proceeds to S116.

  In S110, ECU 900 determines whether or not the elapsed time after the N contact changes from ON to OFF is within a predetermined time T (0). If the elapsed time is within predetermined time T (0) (YES in S110), the process proceeds to S112. If not (NO in S110), the process proceeds to S114.

  In step S112, the ECU 900 sets the command pressure to the non-contact pressure P (3) that is lower than the low pressure hydraulic pressure P (2). In S114, ECU 900 performs normal garage control. That is, the command pressure is controlled in the clutch direct pressure mode.

  In S116, ECU 900 performs normal “N” position control. That is, the command pressure is set to the oil pressure P (2) at the low temperature. In S118, ECU 900 sets the command pressure to oil pressure P (2) at a low temperature.

  The transition of the command pressure controlled by the control device according to the present embodiment based on the above-described structure and flowchart will be described. It is assumed that shift lever 920 is currently in the “N” position.

  Since shift lever 920 is located at the “N” position, all of D contact, R contact and B contact of position sensor 918 are OFF (YES in S100), and N contact is ON (in S102). YES).

  Therefore, the command pressure is set to the oil pressure P (2) at the time of low temperature, as indicated by the one-dot chain line in FIG. 7 (S116). From this state, when the shift lever 920 starts to be slowly operated from the “N” position to the “D” position at time T (1), the shift lever 920 is moved to either the “D” position or the “N” position. Is not located.

  That is, all of D contact, R contact, and B contact of position sensor 918 are OFF (YES in S100), and N contact is changed from ON to OFF (NO in S100, S104) YES) When the non-contact state is reached, the elapsed time from the non-contact state is measured (S106).

  Even if the shift lever 920 is not in the non-contact state, that is, even if the shift lever 920 is not completely positioned at the “D” position, the spool of the manual valve 1310 is moved by operating the shift lever 920. Therefore, the oil passage connecting the garage shift valve 1340 and the hydraulic servo of the forward clutch 406 begins to communicate. Therefore, the garage shift pressure PG starts to be supplied from the garage shift control valve 1330 to the hydraulic servo of the forward clutch 406, and the forward clutch 406 may be engaged.

  If the forward clutch 406 is engaged in a state where the command pressure is high, there is a risk that a shock accompanying the engagement will occur. In order to suppress the shock, forward clutch 406 is in a disengaged state (YES in S108), and if the elapsed time from the non-contact state is within a predetermined time T (0) (YES in S110). ), The command pressure is reduced to a non-contact hydraulic pressure P (3) lower than the hydraulic pressure P (2) at the low temperature (S112). Thereby, generation | occurrence | production of the shock at the time of operating the shift lever 920 slowly can be suppressed.

  When the command pressure is set to the non-contact hydraulic pressure P (3) (S112), and at time T (2), the shift lever 920 is completely positioned at the “D” position and the D contact is turned on ( Normal garage control is performed (YES in S100). That is, the command pressure is increased from the non-contact hydraulic pressure P (3) to the initial control pressure, and thereafter, a constant pressure standby pressure lower than the initial control pressure is maintained. After the constant pressure standby pressure is maintained for a predetermined time, the command pressure is gradually increased with a predetermined gradient.

  On the other hand, when the forward clutch 406 is in the engaged state, if the command pressure decreases to the contactless hydraulic pressure P (3), the hydraulic pressure supplied to the hydraulic servo of the forward clutch 406 decreases. As a result, the forward clutch 406 slips and a shock may occur.

  Therefore, when forward clutch 406 is in an engaged state (NO in S108), normal “N” position control is performed (S116), and the command pressure is not reduced to non-contact-time hydraulic pressure P (3). The oil pressure P (2) at low temperature is set. Thereby, generation | occurrence | production of a shock can be suppressed.

  In addition, if the D contact cannot be detected because the position sensor 918 is abnormal and the shift lever 920 is in the “D” position, the non-contact state continues and the command pressure Is maintained at the non-contact pressure oil pressure P (3).

  In this case, since the normal garage control (S114) is not performed, there is a possibility that the forward clutch 406 cannot be engaged. Therefore, if the elapsed time from the non-contact state exceeds predetermined time T (0) (NO in S110), normal garage control is performed (S114), and forward clutch 406 is engaged. Is done.

  As described above, when the shift lever is operated from the “N” position and the position switch contacts are all in the non-contact state, the ECU of the control device according to the present embodiment sets the command pressure at a low temperature. The hydraulic pressure P (2) is reduced to the non-contact hydraulic pressure P (3). As a result, when the shift lever is operated slowly from the “N” position to the “D” position, the command pressure in the non-contact state is maintained at the oil pressure at the low temperature, as shown by the one-dot chain line in FIG. Compared to the case, the occurrence of shock accompanying the engagement of the forward clutch can be suppressed.

  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 timing chart which shows transition of the command pressure set up by ECU of the control device concerning an embodiment of the invention in normal temperature. It is a flowchart which shows the program which ECU of the control apparatus which concerns on embodiment of this invention performs. It is a timing chart which shows transition of the command pressure set by ECU of the control device concerning an embodiment of the invention at the time of low temperature. It is a timing chart which shows transition of the conventional command pressure at the time of low temperature.

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, 902 Engine speed sensor, 904 Turbine speed sensor, 912 Oil temperature sensor, 918 Position sensor, 920 Shift lever, 922 Primary pulley speed sensor, 924 Secondary pulley speed sensor, 930 Nipping pressure control unit, 932 Engagement transient hydraulic control Part, 1000 electronic throttle valve, 1100 fuel injection device, 1200 ignition device, 1300 hydraulic control circuit, 1320 clamping pressure control valve, 1330 garage shift control Control valve, 1340 garage shift valve, 1350 modulator valve, 1360 linear solenoid valve (SLS), 1370 solenoid valve (SL).

Claims (4)

A control device for an automatic transmission equipped with a power transmission device connected to a power source via a friction engagement element, wherein the friction engagement element is engaged by being supplied with hydraulic pressure,
A pressure regulating valve that regulates the hydraulic pressure generated by the hydraulic pressure source by the control pressure from the solenoid valve;
A switching valve that switches communication and blocking of an oil passage that supplies hydraulic pressure from the pressure regulating valve to the friction engagement element in conjunction with a position of a shift lever;
Detection means for detecting the position of the shift lever;
Control means for controlling the electromagnetic valve so as to regulate the hydraulic pressure by the pressure regulating valve in response to a driver's shift operation,
The switching valve communicates the oil passage until the shift lever moves from a position corresponding to the non-travel position to a position corresponding to the travel position,
The control means includes
Means for controlling the solenoid valve to regulate the hydraulic pressure to a first hydraulic pressure by the pressure regulating valve when it is detected that the shift lever is in a position corresponding to a non-traveling position;
The pressure control valve controls the hydraulic pressure from the hydraulic source between the time when it is detected that the shift lever is not at the position corresponding to the non-travel position and the time when it is detected that the shift lever is at the position corresponding to the travel position. Means for controlling the solenoid valve so as to regulate the second hydraulic pressure lower than the hydraulic pressure of the automatic transmission.   The switching valve shuts off the oil passage when the shift lever is in a position corresponding to a non-travel position, and communicates the oil passage when the shift lever is in a position corresponding to a travel position. The control apparatus of the automatic transmission as described in 1. Before SL control apparatus further includes means for measuring the shift lever is detected not in the position corresponding to the non-driving position and not in a position corresponding to the running position and the detected elapsed time,
The control means includes means for controlling the electromagnetic valve so that the friction engagement element is engaged when the elapsed time exceeds a predetermined time. 2. A control device for an automatic transmission according to 2. Before SL control apparatus further includes a means for the frictional engagement element is determined whether or not the engagement state,
When the control means detects that the shift lever is not in a position corresponding to a non-traveling position and determines that the friction engagement element is engaged, the control means controls the hydraulic pressure by the pressure regulating valve. The control device for an automatic transmission according to any one of claims 1 to 3, further comprising means for controlling the solenoid valve so as to regulate the first hydraulic pressure.

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