JP4787855B2 - Control device for continuously variable transmission - Google Patents

Description

  The present invention relates to a control device for a continuously variable transmission.

  Conventionally, in a continuously variable transmission, when the driver switches the select lever from the N range to the D range (or R range) when starting, the movement is transmitted to the manual valve by a physical interlocking mechanism. The forward clutch (or the reverse clutch (brake) is moved to a position where the clutch original pressure and the piston oil chamber of the forward clutch communicate with each other (or a position where the clutch original pressure and the piston oil chamber of the reverse clutch (brake) communicate with each other). )) To transmit the engine torque to the continuously variable transmission.

  When the select lever is switched from the N range to the D range (or R range), the inhibitor switch signal indicates that it is in the D range (or R range). Due to backlash or the like, the clutch and the manual valve may not communicate with each other (referred to as a pseudo-D state).

  In this case, when the driver thinks that the clutch is engaged, and depresses the accelerator, the engine speed is increased rapidly because the clutch is not yet engaged. Also, if the manual valve is in communication and the clutch is engaged after the engine speed has increased rapidly, an engagement shock will occur and an instantaneous large torque will be applied to the V-belt of the continuously variable transmission, causing belt slippage. There is a risk that.

  Therefore, after switching from the N range to the D range (or R range), the throttle opening is increased until the clutch input side rotational speed (turbine rotational speed) reaches a predetermined rotational speed (0 km / h when stopped). There is one that closes to an idling time to suppress a sudden increase in engine rotation speed (for example, Patent Document 1).

  However, such a technique requires a sensor that detects the input side rotational speed (turbine rotational speed) of the clutch, and requires that the driver start the vehicle by operating the accelerator to increase the engine rotational speed. Even in such a situation, the engine rotational speed is forcibly lowered to the level equivalent to the idle, and there is a problem that the driver feels uncomfortable.

Therefore, after switching from the N range to the D range (or R range) so that it can be realized even if there is no sensor for detecting the input side rotational speed (turbine rotational speed) of the clutch, the engine rotational speed is changed. When the actual measured value exceeds the estimated value of the engine speed calculated assuming that the clutch is engaged, it is determined that the clutch is not engaged and the engine output is regulated. (For example, Patent Document 2).
JP 62-292534 A Japanese Patent Laid-Open No. 2004-267341

  In the above invention, even when there is no sensor for detecting the input side rotational speed of the clutch, it is possible to regulate the engine output when the clutch is not engaged. However, since the estimated value of the engine rotation speed is used, accurate determination cannot always be made. Therefore, there is a problem that when the engine output regulation is delayed and the engine speed is rapidly increased or the clutch is engaged at the time of sudden increase, a clutch engagement shock may occur and the V belt may slip.

  The present invention has been invented to solve such problems. Even when there is no sensor for detecting the input side rotational speed of the clutch, the engine output is quickly regulated when the clutch is not engaged, and the engine is blown away. An object of the present invention is to suppress clutch engagement shock and V-belt slip.

  The present invention relates to a control device for a continuously variable transmission that controls a continuously variable transmission that includes a belt that is wound around a primary pulley and a secondary pulley and whose contact radius changes with the width of the groove. Inhibitor switch that outputs a signal according to the operating position, and a manual valve that is displaced according to the select lever operating position and supplies hydraulic pressure to one of the forward clutch or the reverse clutch interposed between the primary pulley and the engine And hydraulic control means for controlling the hydraulic pressure supplied to the manual valve based on the output signal of the inhibitor switch and the driving state of the vehicle, the primary pulley rotational speed detecting means for detecting the rotational speed of the primary pulley, and the output of the inhibitor switch Based on the signal, the select lever operation position switches from the non-travel position to the travel position. When it is determined that the pulse signal has been changed, a pulse signal output determination unit that determines whether or not a pulse signal is output from the primary pulley rotation speed detection unit, and an output of the engine when the pulse signal is not output within a predetermined time. First engine output limiting means for limiting.

  According to the present invention, even when there is no sensor for detecting the input side rotational speed of the clutch, it is possible to accurately determine the communication state between the manual valve and the forward clutch or the reverse clutch, and to quickly regulate the engine output when the clutch is not engaged. It is possible to suppress the engine idling, clutch engagement shock, and V-belt slip.

  Hereinafter, embodiments of the present invention will be described in more detail with reference to the drawings.

  FIG. 1 is a diagram illustrating an embodiment of a clutch engagement control device for an automatic transmission according to the present invention.

  The automatic transmission includes a hydraulic pump 10, a torque converter 20, a forward / reverse switching clutch 30, and a CVT transmission unit 40, and is controlled by a control unit 60. The automatic transmission receives a driving force from the engine 70, shifts the driving force, and outputs it to the driving wheels 80.

  The hydraulic pump 10 is driven by the engine 70 to pump oil. The pressure-fed oil is adjusted by the line pressure adjusting device 11. The adjusted hydraulic pressure is further adjusted by the primary pressure adjusting device 12 and the secondary pressure adjusting device 13 and supplied to the primary pulley 41 and the secondary pulley 42, and the primary pulley 41 and the secondary pulley 42 are operated to change speed. . The hydraulic pressure branched by the line pressure adjusting device 11 is sent to the forward clutch piston chamber 32a and the reverse brake piston chamber 33a via the clutch pressure adjusting device (hydraulic control means) 14 and the manual valve 57 to control the clutch engagement. .

  The torque converter 20 is provided between the engine 70 and the forward / reverse switching clutch 30 and transmits the driving force of the engine 70 by the internal oil flow. The torque converter 20 has a lockup mechanism for eliminating a rotational difference between the pump impeller and the turbine runner.

  The forward / reverse switching clutch 30 includes a planetary gear 31 that switches a power transmission path between the engine side and the CVT transmission unit side, a forward clutch 32, and a reverse brake 33. The forward clutch 32 is connected to the forward clutch piston, and is fastened to the planetary gear 31 by the hydraulic pressure (forward clutch pressure) supplied to the forward clutch piston chamber 32a when the vehicle moves forward. The reverse brake 33 is connected to the reverse brake piston and is fastened to the planetary gear 31 by the force of hydraulic pressure (reverse brake pressure) supplied to the reverse brake piston chamber 33a when the vehicle reverses. Further, no hydraulic pressure is supplied at the neutral position (neutral or parking), and both the forward clutch 32 and the reverse brake 33 are released. When the forward clutch 32 is engaged with the planetary gear 31, forward rotation is output, and when the reverse brake 33 is engaged with the planetary gear 31, reverse rotation is output.

  The forward clutch 32 and the reverse brake 33 are exclusively engaged, and at the time of forward movement, the forward clutch pressure is supplied to fasten the forward clutch 32, and the reverse brake pressure is connected to the drain to release the reverse brake 33. . On the other hand, during reverse travel, the forward clutch pressure is connected to the drain to release the forward clutch 32, and the reverse brake pressure is supplied to engage the reverse brake 33. In the neutral position, the forward clutch pressure and the reverse brake pressure are connected to the drain, and both the forward clutch 32 and the reverse brake 33 are released.

  The CVT transmission unit 40 includes a primary pulley 41, a secondary pulley 42, and a V belt 43.

  The primary pulley 41 is an input shaft side pulley that inputs the driving force of the engine 70. The primary pulley 41 has a fixed conical plate 41a that rotates integrally with the input shaft 41c, a V-shaped pulley groove that is disposed opposite to the fixed conical plate 41a, and a hydraulic pressure that acts on the primary pulley (hereinafter referred to as the primary pulley). And a movable conical plate 41b that can be displaced in the axial direction by "primary pressure". The rotation speed (input rotation) of the primary pulley 41 is detected by a primary pulley rotation speed sensor (primary pulley rotation speed detecting means) 41d.

  The secondary pulley 42 transmits the driving force transmitted by the V belt 43 to the driving wheel 80 via an idler gear or a differential gear. The secondary pulley 42 has a fixed conical plate 42a that rotates integrally with the output shaft 42c, a V-shaped pulley groove disposed opposite to the fixed conical plate 42a, and a hydraulic pressure (hereinafter referred to as hydraulic pressure) that acts on the secondary pulley. And a movable conical plate 42b that can be displaced in the axial direction according to "secondary pressure"). In addition, the pressure receiving area of the secondary pulley and the pressure receiving area of the primary pulley are the same or almost the same. The speed of rotation (output rotation) of the secondary pulley 42 is detected by a secondary pulley rotation speed sensor 42d. Note that the vehicle speed is calculated from the rotational speed of the secondary pulley 42.

  The V belt 43 is wound around the primary pulley 41 and the secondary pulley 42, and transmits the driving force input to the primary pulley 41 to the secondary pulley 42.

  The primary pulley rotation speed sensor 41d faces an output gear (not shown) attached to the primary pulley 41. Teeth are formed at equal intervals on the outer periphery of the output gear. For this reason, the output waveform detected by the primary pulley rotation speed sensor 41d is a pulse having an equal pitch at a constant vehicle speed. That is, the primary pulley rotation speed sensor 41 d is configured by a pulse sensor that outputs a pulse signal synchronized with the rotation of the primary pulley 41.

  When the position of the select lever 51 is in the N range (non-traveling position) and the vehicle is stopped, rotation from the engine 70 is not transmitted to the primary pulley 41, so the primary pulley 41 rotates. Not. Therefore, the primary pulley rotation speed sensor 41d does not output a pulse signal. However, when the position of the select lever 51 is changed from the N range to, for example, the D range (traveling position), forward clutch pressure is supplied to fasten the forward clutch 32, and the engine 70 is connected to the output side of the forward clutch 32. Torque is transmitted gradually from. Then, torque is transmitted to the primary pulley 41, and the primary pulley 41 rotates. As a result, the primary pulley rotation speed sensor 41 d outputs a pulse signal to the control unit 60.

  The control unit 60 inputs the signals of the primary rotational speed sensor 41d and the secondary rotational speed sensor 42d, calculates the current gear ratio from these signals, and controls the primary pressure and the secondary pressure so that the desired gear ratio is obtained. . Further, a clutch pressure command signal is output to the clutch pressure adjusting device 14 by a signal from the inhibitor switch 56 to control the forward / reverse switching clutch 30.

  FIG. 2 is a diagram showing the structure of the transmission.

  The select lever 51 is rotatable around a fulcrum 51a. The select lever 51 is connected to a wire 52. The other end of the wire 52 is connected to the link 53. The link 53 performs a rotational motion around the fulcrum 53a. The other end of the link 53 is connected to the slider 54. The slider 54 connects the switch 56a of the inhibitor switch 56 via a connecting rod 55a. The switch 56a enables conduction between the power supply terminal 56b and any one of the D range terminal 56c, the N range terminal 56d, and the R range terminal 56e. The slider 54 connects the manual valve 57 via a connecting rod 55b.

  When the driver operates the select lever 51 as indicated by the arrow, the link 53 rotates as indicated by the arrow via the wire 52. Then, the slider 54 moves as indicated by an arrow. Then, the switch 56a is moved in accordance with the movement of the slider 54, and the power supply terminal 56b is electrically connected to any one of the D range terminal 56c, the N range terminal 56d, and the R range terminal 56e. At the same time, the manual valve 57 is moved in accordance with the movement of the slider 54 to control the hydraulic pressure supplied to the forward / reverse switching clutch 30.

  At this time, for example, although the power supply terminal 56b and the D range terminal 56c are electrically connected by the operation of the select lever 51, the manual valve 57 and the forward clutch are not in communication with each other, but the forward clutch 32 is not connected. May not be able to supply hydraulic pressure.

  At this time, although the clutch is not engaged, the driver has selected the D range, so the accelerator pedal may be subsequently depressed. Then, since the clutch is in a non-coupled state, the driving force of the engine is not transmitted to the driving wheels, and the engine is blown away.

  In this state, the driver may push the select lever 51 further in the D direction, or the select lever 51 may be further moved in the D direction by the engine roll when the engine is idle, and the manual valve 57 may be in the D range.

  In such a case, since the INH signal of the D range is sent from the inhibitor switch 56 at the time of the first operation of the select lever, the INH signal does not change even if it is pushed further in the D direction after the air blows. Therefore, normal select control cannot be performed. However, the actual clutch pressure is supplied by moving the manual valve 57, and the clutch is engaged. However, since the engine is in a state where the engine is increased to a high rotational speed by air blowing, a large engagement shock may occur when the clutch is engaged, and slipping may occur in the V-belt 43.

  In the present application, when such a range unmatched state is reached, a predetermined control is performed to reduce the fastening shock.

  Next, clutch hydraulic pressure control performed by the clutch pressure adjusting device 14 will be described with reference to the flowchart of FIG.

  In step S1, the inhibitor switch 56 reads the current INH signal.

  In step S2, it is determined whether a flag (hereinafter referred to as an ND switching flag) F_nd indicating whether or not the select lever 51 has been switched from the N range to the D range is off. If the ND switching flag F_nd is off, the process proceeds to step S3. If the ND switching flag F_nd is on, the process proceeds to step S6. In the first determination of this control, the ND switching flag F_nd is off, and the process proceeds to step S3.

  In step S3, the previous control INH signal is read and compared with the current INH signal read in step S1. Then, it is determined whether or not the select lever 51 has been switched from the N range to the D range. When the select lever 51 is switched from the N range to the D range, the process proceeds to step S4. When the select lever 51 is not switched from the N range to the D range, the process proceeds to step S30.

  In step S4, the ND switching flag F_nd is turned on. Also, the phase flag F_phase is set to zero indicating the initialization phase.

  In step S5, the precharge pressure P_pc, precharge time T_pc, engagement initial pressure P_start, first ramp increase rate ΔP_r1, first ramp time T_r1, second ramp increase rate ΔP_r2, and second ramp time T_r2 are read from the ROM of the control unit 60. Read the nominal value of.

  If it is determined in step S2 that the ND switching flag F_nd is on, or if the nominal value is read from the control unit 60 in step S5, the selection is performed during switching control from the N range to the D range in step S6. It is determined whether the lever 51 has been changed from the D range to the N range. If the select lever 51 is changed from the D range to the N range, the process proceeds to step S33. If the select lever 51 is not changed from the D range to the N range, the process proceeds to step S7.

  In step S7, it is determined whether or not a pseudo D establishment flag F_false, which will be described later, is on. If the pseudo D establishment flag F_false is on, the process proceeds to step S34. If the pseudo D establishment flag F_false is off, the process proceeds to step S8.

  If the pseudo D establishment flag F_false is on in step S7, it is determined in step S8 whether or not the current phase is an initialization phase. Here, it is determined whether or not the phase flag F_phase is zero indicating the initialization phase. When the phase flag F_phase is zero, the process proceeds to step S9, and when the phase flag F_phase is not zero, the process proceeds to step S11.

  In step S9, since the ND switching flag F_nd is on and the nominal value is read, the phase flag F_phase is set to 1 to indicate the transition to the precharge phase.

  In step S10, a first timer tm_1 for determining the elapsed time of the precharge phase is initialized to zero.

  In step S11, it is determined whether the current phase is a precharge phase. Here, it is determined whether or not the phase flag F_phase is 1 indicating the precharge phase. If the phase flag F_phase is 1, the process proceeds to step S12. If the phase flag F_phase is not 1, the process proceeds to step S18.

  In step S12, it is determined whether or not the first timer tm_1 has reached the precharge time T_pc read in step S5. If the first timer tm_1 has not reached the precharge time T_pc, the process proceeds to step S13. If the first timer tm_1 has reached the precharge time T_pc, the process proceeds to step S15.

  In step S13, the precharge pressure P_pc read in step S5 is set as the clutch hydraulic pressure command value P_target. The precharge pressure P_pc is the maximum pressure of the clutch hydraulic pressure command value, and thereby the invalid stroke of the forward clutch 32 can be quickly reduced.

  In step S14, the first timer tm_1 is incremented.

  In step S12, when the first timer tm_1 has reached the precharge time T_pc, the precharge phase has ended. Therefore, in step S15, the phase flag F_phase is set to 2 indicating the fastening progress phase.

  In step S16, a second timer tm_2 for determining the elapsed time of the fastening progress phase is initialized to zero.

  In step S17, the clutch hydraulic pressure command value P_target is set to the engagement initial value P_start read in step S5.

  If it is determined in step S11 that the phase flag F_phase is not 1, it is determined in step S18 whether or not the current phase is the fastening progress phase. Here, it is determined whether or not the phase flag F_phase is 2 indicating the fastening progress phase. If the phase flag F_phase is 2, the process proceeds to step S19. If the phase flag F_phase is not 2, the process proceeds to step S25.

  In step S19, it is determined whether the second timer tm_2 has reached the first ramp time T_r1 read in step S5. If the second timer tm_2 has not reached the first ramp time T_r1, the process proceeds to step S20. If the second timer tm_2 has reached the first ramp time Tr_1, the process proceeds to step S22.

  In step S20, the clutch hydraulic pressure command value P_target is calculated by adding the first ramp increase rate ΔP_r1 read in step S5 to the clutch hydraulic pressure command value P_target 'in the previous control.

  In step S21, the second timer tm_2 is incremented.

  If the second timer tm_2 has reached the first ramp time Tr_1 in step S19, the fastening progress phase has ended. Therefore, in step S22, the phase flag F_phase is set to 3 indicating the final fastening phase.

  In step S23, a third timer tm_3 for determining the elapsed time of the final engagement phase is initialized to zero.

  In step S24, the clutch hydraulic pressure command value P_target is calculated by adding the second ramp increase rate ΔP_r2 to the clutch hydraulic pressure command value P_target 'in the previous control.

  At this time, since the forward clutch 32 has already started torque transmission, in order to quickly complete the engagement of the forward clutch 32, the second ramp increase rate ΔP_r2 larger than the first ramp increase rate ΔP_r1 Increase the clutch command oil pressure P_target.

  If it is determined in step S18 that the phase flag F_phase is not 2, it is determined in step S25 whether the third timer tm_3 has reached the second ramp time T_r2 read out in step S5. When the third timer tm_3 has not reached the second ramp time T_r2, the process proceeds to step S26, and when the third timer tm_3 has reached the second ramp time T_r2, the process proceeds to step S28.

  In step S26, the clutch hydraulic pressure command value P_target is calculated by adding the second ramp increase rate ΔP_r2 to the clutch hydraulic pressure command value P_target 'in the previous control.

  In step S27, the third timer tm_3 is incremented.

  If it is determined in step S25 that the third timer tm_3 has reached the second ramp time T_r2, it is determined in step S28 that the forward clutch 32 has been engaged, and the ND switching flag F_nd is turned off.

  In step S29, the clutch hydraulic pressure command value P_target is set to the normal clutch engagement pressure.

  If it is determined in step S3 that the select lever 51 has not been switched from the N range to the D range, it is determined in step S30 whether the select lever 51 is in the D range. If it is in the D range, the process proceeds to step S31. If the select lever 51 is in the N range, the process proceeds to step S32.

  In step S31, the clutch hydraulic pressure command value P_target is set to the normal clutch engagement pressure.

  In step S32, the clutch hydraulic pressure command value P_target is set to the minimum pressure. The minimum pressure is, for example, 0 MPa. Thereby, the forward clutch pressure is not supplied, and the forward clutch 32 is maintained in the released state.

  If it is determined in step S6 that the select lever 51 has been changed from the D range to the N range, in step S33, the ND switching flag F_nd indicating that the select lever 51 has been changed from the N range to the D range is set to off. To do.

  If it is determined in step S7 that the pseudo D establishment flag F_false is on, the clutch hydraulic pressure command value P_target is set to the minimum pressure in step S34. The minimum pressure is, for example, 0 MPa. When the pseudo D establishment flag F_false is on, the clutch hydraulic pressure command value P_target is set to the minimum pressure so that the forward clutch 32 is not engaged.

  In step S35, the hydraulic pressure supplied to the forward clutch 32 is controlled by the clutch pressure adjusting device 14 so that the clutch hydraulic pressure command value P_target set by the above control is obtained.

  By the above control, when the select lever 51 is changed from the N range to the D range, the clutch hydraulic pressure command value P_target is controlled and the forward clutch 32 is engaged.

  Next, the pseudo D determination control will be described with reference to the flowchart of FIG. This determination control is performed in parallel with the flowchart shown in FIG.

  In step S101, it is determined whether or not the pseudo-D determination flag F_det_false is on. If the pseudo-D determination flag F_det_false is off, the process proceeds to step S102. If the pseudo-D determination flag F_det_false is on, the process proceeds to step S113. At the time of the first determination after the start of this control, since the pseudo-D determination flag F_det_false is off, the process proceeds to step S102.

  In the pseudo D determination, it is determined whether or not the manual valve 57 operates normally and supplies hydraulic pressure to the forward clutch 32 when the select lever 51 is changed from the N range to the D range.

  In step S102, it is determined whether the ND switching flag F_nd has been changed from off to on. This determination is made based on whether or not the select lever 51 has been switched from the N range to the D range in step S3 of the flowchart shown in FIG. 3, and whether or not the ND switching flag F_nd is turned on in step S4. . When the ND switching flag F_nd is changed from off to on, the process proceeds to step S103. When the ND switching flag F_nd is maintained in the off or on state, the current control is terminated.

  In step S103, engine output restriction is performed. In the engine output restriction, the engine output is temporarily set to a restriction value corresponding to the idle rotation speed, and then the restriction is gradually released from the restriction value. In this embodiment, when the select lever 51 is switched from the N range to the D range, the upper limit value of the engine rotation speed is restricted to the rotation speed equivalent to the idle, and then the restriction is relaxed, and the engine rotation speed is gradually increased. Enlarge. As a result, it is possible to prevent the engine speed from rapidly increasing (step S103 constitutes the second engine output control means).

  In step S104, the pseudo-D determination flag F_det_false is turned on, the pseudo-D timer tm_false is set to zero, and the pseudo-D determination establishment flag F_false is turned off.

  In step S <b> 105, the determination reference time (predetermined time) t_false_ref is read from the ROM of the control unit 60. The determination reference time t_false_ref is a time obtained in advance through experiments or the like. A pulse signal is output from the primary pulley rotation speed sensor 41d during the precharge phase and the engagement progress phase from the state where the clutch hydraulic pressure is completely lost. The time until output is obtained, and the time is set appropriately from the relationship with the precharge time in the normal clutch pressure control.

  In step S106, a primary pulley rotation speed signal is read from the primary pulley rotation speed sensor 41d.

  In step S107, it is determined whether or not the primary pulley rotation speed sensor 41d has output a pulse signal. When the primary pulley rotation speed sensor 41d outputs a pulse signal, the process proceeds to step S108. If the primary pulley rotation speed sensor 41d does not output a pulse signal, the process proceeds to step S112 (step S107 constitutes a pulse signal output determination unit).

  In step S108, the pseudo D timer tm_false and the determination reference time t_false_ref are compared. When the pseudo D timer tm_false is smaller than the determination reference time t_false_ref, the process proceeds to step S113. When the pseudo D timer tm_false is greater than the determination reference time t_false_ref, the process proceeds to step S109.

  In step S109, the pseudo D determination flag F_det_false is set to off. If it is determined in step S107 that the primary pulley rotation speed sensor 41d is outputting a pulse signal, the torque is normally transmitted from the engine 70 to the primary pulley 41, so the pseudo-D determination flag F_det_false is turned off.

  In step S110, the pseudo-D timer tm_false is initialized to zero.

  In step S111, since the pulse signal is output from the primary pulley rotation speed sensor 41d and the selection lever 51 is changed from the N range to the D range, the determination reference time t_false_ref has elapsed. In preparation for fastening, the engine output restriction is terminated.

  If it is determined in step S107 that the primary pulley rotation speed sensor 41d does not output a pulse signal, the pseudo D timer tm_false and the determination reference time t_false_ref are compared in step S112. When the pseudo D timer tm_false is smaller than the determination reference time t_false_ref, the process proceeds to step S113. When the pseudo D timer tm_false is greater than the determination reference time t_false_ref, the process proceeds to step S114.

  In step S113, the pseudo D timer tm_false is incremented.

  If it is determined in step S112 that the pseudo D timer tm_false is greater than the determination reference time t_false_ref, the pseudo D determination establishment flag F_false is turned on in step S114.

  The pseudo D timer tm_false, which is the elapsed time since the change of the select lever 51 from the N range to the D range, has become larger than the determination reference time t_false_ref, so the select lever 51 has been changed from the N range to the D range. Nevertheless, it is determined that the forward clutch 32 and the manual valve 57 are not in communication, and the pseudo D determination establishment flag F_false is turned on.

  In step S115, engine output idle restriction is performed. In the engine output idle restriction, the engine output is temporarily set to a restriction value corresponding to the idle rotation speed. In this embodiment, the upper limit value of the engine rotational speed is restricted to a rotational speed equivalent to idle. Here, during the engine output restriction started in step S103, the engine rotation speed is further restricted to a rotation speed equivalent to idle. It should be noted that the throttle opening may be regulated to be equivalent to idle. As a result, it is possible to prevent the engine speed from rapidly increasing when the manual valve 57 is not in communication even though the select lever 51 is changed from the N range to the D range. The subsequent engagement shock due to the communication between the manual valve 57 and the forward clutch 32 or the slip of the V-belt 43 can be suppressed (step S115 constitutes the first engine output control means).

  If it is determined in step S101 that the pseudo D determination flag F_det_false is on, that is, the pseudo D determination process has already been started, it is determined in step S116 whether the ND switching flag F_nd has been switched from on to off. . If the ND switching flag F_nd is switched from on to off, the process proceeds to step S118. If the ND switching flag F_nd is not switched from on to off, the process proceeds to step S117.

  In step S117, it is determined whether or not the pseudo D establishment flag F_false is off. If the pseudo D establishment flag F_false is off, the process proceeds to step S106 and the above control is repeated. When the pseudo D establishment flag F_false is on, the engine output is maintained at a regulation value equivalent to the idle rotation speed, and this control is terminated.

  In step S118, the INH signal is read from the inhibitor switch 56.

  In step S119, it is determined whether or not the select lever 51 is in the N range based on the INH signal read in step S118. If the select lever 51 is in the N range, the process proceeds to step S120. If the select lever 51 is not in the N range, the current control is terminated.

  In step S120, the pseudo D determination establishment flag F_false is turned off, the pseudo D determination in progress flag F_det_false is turned off, and the pseudo D timer tm_false is initialized to zero. Further, the engine output restriction and the engine output idle restriction are canceled.

  With the above control, when the select lever 51 is changed from the N range to the D range, the communication state between the manual valve 57 and the forward clutch 32 is confirmed without using the sensor for detecting the input side rotational speed of the clutch. It is possible to suppress a sudden increase in engine rotation speed and clutch engagement shock, and to suppress slipping of the V-belt 43.

  Next, changes in engine speed and actual clutch pressure when the present invention is used will be described with reference to time charts of FIGS. FIG. 5 is a time chart showing changes in engine speed and the like when the present invention is not used. 6 and 7 are time charts showing changes in engine rotation speed and the like when the present invention is used. FIG. 6 is a time chart when a pulse signal is output from the primary pulley rotation speed sensor 41d within the determination reference time t_false_ref. FIG. 7 is a time chart when the pulse signal is not output from the primary pulley rotation speed sensor 41d within the determination reference time t_false_ref.

  When the present invention is not used, when the select lever is changed from the N range to the D range at time t1, the clutch hydraulic pressure command value changes by preset control. At this time, if the manual valve and the forward clutch are in normal communication, the actual clutch pressure increases according to the clutch hydraulic pressure command value.

  However, when the manual valve and the forward clutch are not in normal communication, the actual clutch pressure does not increase (broken line in FIG. 5). Then, when the driver thinks that the forward clutch has been engaged and the accelerator pedal is depressed, the engine blows away, and at time t2, the actual engine speed becomes larger than the preset engine speed estimated value. As a result, it is determined that the manual valve and the forward clutch are not normally communicating. Thereafter, control for restricting the engine output is started, and the clutch hydraulic pressure command value is set to the minimum pressure. However, due to a delay in engine output control, the actual engine speed further increases and the engine blows.

  Thus, when the present invention is not used, the start of the engine output control is delayed, so that it is not possible to accurately prevent the engine from being blown. Further, in the case where the present invention is not used, when the engine blows idle, and then the manual valve and the forward clutch are in communication with each other, a clutch engagement shock may occur, and the V belt may slip.

  When a pulse signal is output from the primary pulley rotation speed sensor 41d within the reference time t_false_ref for determination using the present invention, when the select lever 51 is changed from the N range to the D range at the time t1, the engine rotation The engine output is regulated so that the engine speed is equivalent to the idling engine speed. Then, since the regulation of the engine output is relaxed, the engine speed gradually increases from the engine speed equivalent to the idle.

  When a pulse signal is output from the primary pulley rotational speed sensor 41d at time t2, the engine output restriction is released in preparation for complete engagement of the forward clutch 32 at time t3 when the determination reference time t_false_ref has elapsed.

  Further, using the present invention, when the pulse signal is not output from the primary pulley rotation speed sensor 41d within the determination reference time t_false_ref, the engine rotation speed is restricted to the rotation speed equivalent to the idling at time t3.

  Thus, the communication state between the manual valve 57 and the forward clutch 32 can be accurately determined by using the pulse signal output from the primary pulley rotational speed sensor 41d. Therefore, even when the select lever 51 is changed from the N range to the D range, the engine output can be accurately regulated when the manual valve 57 and the forward clutch 32 are not in communication.

  In this embodiment, the case where the select lever 51 is changed from the N range to the D range has been described. However, the above control can be performed even when the select lever 51 is changed from the N range to the R range. The above control can also be performed when an L range, an S range, a 2 range, and the like are provided.

  The effect of the embodiment of the present invention will be described.

  When it is determined by the INH signal from the inhibitor switch 56 that the select lever 51 has been changed from the N range to the D range, a pulse signal is not output from the primary pulley rotation speed sensor 41d within the determination reference time t_false_ref. By restricting the engine rotational speed, the rapid increase of the engine rotational speed due to the idling of the engine 70 is accurately suppressed, the occurrence of the engagement shock due to the engagement of the forward clutch 32 after the rapid increase of the engine rotational speed, and the V belt 43 Can be prevented (corresponding to claim 1).

  When it is determined by the INH signal from the inhibitor switch 56 that the select lever 51 has been changed from the N range to the D range, a pulse signal is not output from the primary pulley rotation speed sensor 41d within the determination reference time t_false_ref. The engine rotation speed corresponding to the idling is used to accurately suppress a sudden increase in the engine rotation speed due to the idling of the engine 70, the occurrence of the engagement shock due to the engagement of the forward clutch 32 after the rapid increase in the engine rotation speed, and V The slippage of the belt 43 can be suppressed (corresponding to claim 2).

  When the select lever 51 is changed from the N range to the D range by the INH signal from the inhibitor switch 56, the engine rotation speed is temporarily restricted to the engine rotation speed equivalent to the idle, and then the restriction is relaxed to reduce the engine rotation speed. By enlarging it, the engine output regulation delay is prevented, the engine 70 is prevented from being blown, the driver feels uncomfortable during the range switching, the occurrence of the fastening shock, and the slip of the V belt 43. Can be suppressed (corresponding to claim 3).

It is a schematic block diagram of the V belt type continuously variable transmission of embodiment of this invention. It is a schematic block diagram which shows the structure of the transmission of embodiment of this invention. It is a flowchart explaining clutch oil pressure control of the embodiment of the present invention. It is a flowchart explaining the pseudo | simulation D determination control of embodiment of this invention. It is a time chart which shows changes, such as an engine speed, when not using this invention. It is a time chart which shows changes, such as engine speed at the time of using the present invention. It is a time chart which shows changes, such as engine speed at the time of using the present invention.

Explanation of symbols

10 Hydraulic pump 14 Clutch pressure adjusting device (hydraulic control means)
20 Torque converter 30 Forward / reverse switching clutch 32 Forward clutch 33 Reverse brake 41 Primary pulley 41d Primary pulley rotational speed sensor (primary pulley rotational speed detecting means)
42 Secondary pulley 43 V belt 56 Inhibitor switch 57 Manual valve 60 Control unit

Claims (3)

In a continuously variable transmission control device that controls a continuously variable transmission including a belt that is wound around a primary pulley and a secondary pulley, and a contact radius of the pulley changes according to a groove width.
An inhibitor switch that outputs a signal according to the select lever operating position;
A manual valve that is displaced according to the operation position of the select lever and supplies hydraulic pressure to one of a forward clutch or a reverse clutch interposed between the primary pulley and the engine;
Hydraulic control means for controlling the hydraulic pressure supplied to the manual valve based on the output signal of the inhibitor switch and the driving state of the vehicle;
Primary pulley rotation speed detection means for detecting the rotation speed of the primary pulley;
Based on the output signal of the inhibitor switch, it is determined whether or not a pulse signal is output from the primary pulley rotational speed detecting means when it is determined that the select lever operation position has been switched from the non-travel position to the travel position. Pulse signal output determining means for performing,
A control device for a continuously variable transmission, comprising: first engine output limiting means for limiting the output of the engine when the pulse signal is not output within the predetermined time.   2. The continuously variable transmission control device according to claim 1, wherein the first engine output limiting unit limits the rotation speed of the engine to an idle rotation speed. 3. Based on the output signal of the inhibitor switch, when it is determined that the select lever operation position has been switched from the non-travel position to the travel position, the engine speed is limited to an idle speed, 3. The continuously variable transmission control device according to claim 1, further comprising a second engine output limiting unit that gradually releases the limitation on the rotational speed of the engine. 4.