JP2008014325A - Method and system for controlling continuous variable transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and a system for controlling a continuous variable transmission which does not cause instable control during starting. <P>SOLUTION: In this method for controlling the continuous variable transmission 1, the gear ratio of the continuous variable transmission 1 is minimized until the rotational speed of an engine reaches a rotational speed at which a hydraulic pressure can be boosted to a predetermined pressure. The system S for controlling the continuously variable transmission 1 comprises a hydraulic servo mechanism 3 for adjusting the gear ratio of the continuously variable transmission 1 and a controller C for controlling the hydraulic servo mechanism 3. The controller C has a start control part PC for controlling the hydraulic servo mechanism 3 during starting. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a control method and a control system for a continuously variable transmission. More specifically, the present invention relates to a control method and a control system for a continuously variable transmission used in a power generator driven by an engine such as an aircraft or a vehicle.

  2. Description of the Related Art Conventionally, a power generation device driven by an engine output of an aircraft is known as an aircraft power generation device. In this power generation apparatus, a transmission is provided between the engine and the power generation apparatus because the rotation speed of the power generation apparatus needs to be constant even if the engine output, that is, the engine rotation speed fluctuates.

  Attempts have been made to use a toroidal continuously variable transmission as this transmission. In this toroidal-type continuously variable transmission, a power roller is disposed so as to be tiltable between a pair of input disks and output disks formed on a toroidal curved surface, and the tilt angle of the power roller is controlled to control the transmission. The output rotational speed is constant, that is, the generator rotational speed is constant.

  However, since the tilt angle is controlled using a hydraulic control circuit, immediately after the engine is started, the fluidity of the control oil is not sufficient, and the fluidity of the traction oil is not sufficient. When normal feedback control is performed, there is a problem that desired control cannot be achieved.

  In order to solve such a problem, Patent Document 1 proposes a method of determining whether a transmission is in a low gear ratio position by a limit switch at the start, and if not in a low gear ratio position, a method of setting the gear ratio to a low gear ratio position is proposed. Has been.

  However, in the method according to the proposal of Patent Document 1, not only the configuration for realizing the method is complicated, but a failure of the limit switch is expected to lead to a failure of the entire system, and the reliability is poor. There's a problem.

Note that the problem that the desired control cannot be achieved because the fluidity of the oil is not sufficient at the time of start-up is remarkable in start-up in a cold region. No proposal has been made.
Japanese Patent Laid-Open No. 62-273187

  The present invention has been made in view of the problems of the prior art, and an object thereof is to provide a control method and a control system for a continuously variable transmission that does not cause control instability at the time of startup.

  A first aspect of the control method for a continuously variable transmission according to the present invention is a control method for a continuously variable transmission including a hydraulic servo mechanism disposed in an oil system having a pump driven by an output shaft of a prime mover. The hydraulic servo mechanism is equipped with a safety mechanism that brings the rotational speed of the rotating machine to a safe rotational speed, determines whether the oil temperature exceeds the reference temperature, and if the oil temperature exceeds the reference temperature, normal start control Thus, the hydraulic servomechanism prevents the power roller of the continuously variable transmission from moving to the position where the rotational speed of the continuously variable transmission is brought to an unsafe rotational speed until the rotational speed of the prime mover reaches the rotational speed at which the hydraulic pressure is increased to a predetermined pressure. It is characterized by controlling.

  In the first aspect of the control method for a continuously variable transmission according to the present invention, if the oil temperature does not exceed the reference temperature, the low temperature start control controls the continuously variable transmission until the oil temperature exceeds the reference temperature. It is preferable to control the hydraulic servomechanism so that the power roller does not reach a position where the rotational speed of the rotating machine is brought to an unsafe rotational speed.

  A second aspect of the control method for a continuously variable transmission according to the present invention is a control method for a continuously variable transmission including a hydraulic servo mechanism disposed in an oil system having a pump driven by an output shaft of a prime mover. The hydraulic servo mechanism includes a safety mechanism that brings the rotational speed of the rotating machine to a safe rotational speed, determines whether the oil temperature exceeds a first reference temperature, and the oil temperature exceeds the first reference temperature. If not, the servo valve spool of the hydraulic servomechanism is reciprocated by primary start control so that the power roller of the continuously variable transmission does not reach a position where the rotational speed of the rotating machine is brought to an unsafe rotational speed. It is characterized by that.

  In the second embodiment of the control method for a continuously variable transmission according to the present invention, when the oil temperature exceeds the first reference temperature, the engine speed is increased so that the engine speed is increased to a predetermined pressure by the normal start control. It is preferable to control the hydraulic servomechanism so that the power roller of the continuously variable transmission does not reach a position where the rotational speed of the rotating machine is brought to an unsafe rotational speed until the value reaches.

  In the second embodiment of the control method for a continuously variable transmission according to the present invention, the prime mover rotational speed does not exceed the rotational speed at which the hydraulic pressure is increased to a predetermined pressure, and the oil temperature does not exceed the second reference temperature. It is preferable to feedback-control the speed ratio of the continuously variable transmission by secondary start control while limiting the rate of change.

  Furthermore, in the second embodiment of the control method for a continuously variable transmission according to the present invention, it is preferable that the restriction on the change rate of the transmission ratio is relaxed as the oil temperature increases.

  Further, in the first and second embodiments of the control method of the continuously variable transmission according to the present invention, the oil temperature is detected by a plurality of temperature sensors, the start control is performed by one of the detected values, and the temperature used for the control is detected. When the sensor becomes abnormal, it is preferable to switch to the other temperature sensor and perform start control.

  Furthermore, in the first and second embodiments of the control method for a continuously variable transmission according to the present invention, it is preferable to perform start control by timed management when all of the plurality of temperature sensors become abnormal.

  Furthermore, in the first and second embodiments of the control method of the continuously variable transmission according to the present invention, when the rotational speed of the rotary machine exceeds the specified rotational speed and becomes an excessive rotational speed, the rotational speed of the rotary machine is brought closer to the safety side. Processing is preferred.

  Thus, in the first and second embodiments of the continuously variable transmission control method of the present invention, the prime mover is an engine, the rotating machine is a generator, and the safety mechanism is a null bias of the servo valve.

On the other hand, a first form of a control system for a continuously variable transmission according to the present invention is a continuously variable transmission including a control device and a hydraulic servomechanism disposed in an oil system having a pump driven by an output shaft of a prime mover. Control system
The hydraulic servo mechanism includes a safety mechanism that brings the rotational speed of the rotating machine to a safe rotational speed,
The control device includes a start time control unit having a normal start control unit and a low temperature start control unit,
If the oil temperature exceeds the reference temperature, the normal start control unit determines that the power roller of the continuously variable transmission has an unsafe rotational speed until the prime mover rotational speed reaches a specified rotational speed. The hydraulic servo mechanism is controlled so as not to reach the position
If the oil temperature does not exceed the reference temperature, the low-temperature start control unit is a position where the power roller of the continuously variable transmission brings the rotating machine rotation speed to an unsafe rotation speed until the oil temperature exceeds the reference temperature. The hydraulic servo mechanism is controlled so as not to become.

A control system for a continuously variable transmission according to a second aspect of the present invention is a control for a continuously variable transmission including a control device and a hydraulic servomechanism disposed in an oil system having a pump driven by an output shaft of a prime mover. A system,
The hydraulic servo mechanism includes a safety mechanism that brings the rotational speed of the rotating machine to a safe rotational speed,
The control device includes a start time control unit having a normal start control unit and a low temperature start control unit,
The low temperature start control unit includes a primary start control means and a secondary start control means having a gear ratio command limiting means,
If the oil temperature exceeds the first reference temperature, the normal start control unit causes the power roller of the continuously variable transmission to unsafely rotate the rotational machine speed until the prime mover rotational speed reaches a specified rotational speed. The hydraulic servomechanism is to be controlled so that it does not reach a position where the rotational speed is approached.
If the oil temperature does not exceed the first reference temperature, the primary start control means causes the spool of the servo valve of the hydraulic servo mechanism and the power roller of the continuously variable transmission to unsafely rotate the rotating machine. It shall be controlled to reciprocate while avoiding the position approaching the rotational speed,
The secondary start control means is configured to control the continuously variable transmission according to the secondary start control unless the motor speed exceeds the speed at which the hydraulic pressure is increased to a predetermined pressure and the oil temperature does not exceed the second reference temperature. The speed change ratio is feedback-controlled while limiting the rate of change.

  In the first and second embodiments of the control system for continuously variable transmission according to the present invention, the start time control unit includes a timed start control unit, and the timed start control unit performs start control by time management. Preferably it is.

  In the first and second forms of the control system for continuously variable transmission according to the present invention, the control device includes a safety means, and the safety means has a rotational speed exceeding a specified rotational speed and an overspeed. In such a case, it is preferable that the rotational speed of the rotary machine be brought to a safe side.

  Thus, in the first and second forms of the control system for continuously variable transmission according to the present invention, the prime mover is an engine, the rotating machine is a generator, and the safety mechanism is a null bias of the servo valve. The control system for the continuously variable transmission is provided in a rotary machine device such as a power generator.

  Since the present invention is configured as described above, it is possible to obtain an excellent effect that the engine can be started without causing control instability at the time of starting even in a low temperature environment.

  Further, according to the preferred embodiment of the present invention in which the spool is reciprocated, the warm-up of the servo valve is promoted, and an excellent effect can be obtained that quick start-up can be performed even in a low temperature environment.

  Hereinafter, although the present invention is explained based on an embodiment, referring to an accompanying drawing, the present invention is not limited only to this embodiment.

Embodiment 1
FIG. 1 is a functional block diagram showing a control system for a continuously variable transmission to which a control method for a toroidal continuously variable transmission (hereinafter simply referred to as a continuously variable transmission) according to Embodiment 1 of the present invention is applied. 2 shows a control block diagram. In addition, this embodiment shall be applied to the aircraft power generation device.

  As shown in FIGS. 1 and 2, the control system S adjusts the continuously variable transmission 1 by adjusting the position of the continuously variable transmission 1 and the position of the power roller of the continuously variable transmission 1, that is, the tilt angle. A hydraulic drive system A having an angle adjusting mechanism 2 and a hydraulic servo mechanism 3 for driving the tilt angle adjusting mechanism 2 and a control device C for controlling the hydraulic drive system A as main components. Is done. Here, the continuously variable transmission 1 constituting the hydraulic drive system A, and the tilt angle adjusting mechanism for adjusting the gear ratio of the continuously variable transmission 1 by adjusting the tilt angle of the power roller of the continuously variable transmission 1. 2 and a hydraulic servo mechanism 3 for driving the tilt angle adjusting mechanism 2 are housed in a housing 40 (see FIGS. 4 and 5). This housing also has a function as an oil tank.

  As the continuously variable transmission 1 and the tilt angle adjusting mechanism 2, known ones can be suitably used, and thus detailed description of their configurations is omitted.

  3 to 5 show an oil system 30 including a hydraulic circuit 10 to the hydraulic servo mechanism 3.

  The oil system 30 includes an oil tank 41 constituted by a housing 40, a main conduit 50 for supplying oil, and a return conduit (not clearly shown) for returning the oil.

  Specifically, the oil tank 41 includes a lower portion and an upper portion of the housing 40, and the lower portion functions as a normal-time oil tank 41a that supplies oil at a normal time. The oil tank 41b functions. Here, the normal time refers to a state where the acceleration of gravity is positive, and the negative time refers to a state where the acceleration of gravity is negative.

  The main pipeline 50 is configured so that oil can be supplied to the hydraulic servo mechanism 3, the bearing lubrication mechanism, the gear lubrication mechanism, the traction drive lubrication mechanism, the generator cooling mechanism, and the like both at normal time and at minus G time.

  Specifically, the main line 50 is connected to a supply pipe 51 having an oil suction opening in a normal oil tank, and a first pump (for example, a scavenge pump) 52, a first air separator 53, A second pump (for example, a lubrication pump) 54, a filter 55, an oil cooler 56, and a second air separator 57 are interposed in this order. Then, the negative G hour oil is supplied to the supply pipe 51 on the discharge side of the first pump 52 and the oil suction port is opened to the negative G hour oil tank 41b and the negative G hour pump 62 is interposed. A supply pipe 61 for minus G is connected. The supply pipe 51 is provided with temperature sensors Ti and To before and after the oil cooler 56. The first and second pumps 52 and 54 and the minus G hour pump 62 are driven by the output shaft of the engine via a driving force transmission mechanism.

  Here, the second air separator 57 is provided so that the air in the housing 40 is moved in the zero-gravity state that is generated when shifting from the normal time to minus G time or vice versa. This is to avoid instability of the hydraulic servomechanism 3 caused by the oil sucked by the pump and the air sucked.

  The air separators 53 and 57 are, for example, cyclone air separators.

  In addition, the filter 55 and the oil cooler 56 can use suitably the well-known thing used for various lubrication systems, and there is no limitation in particular in the structure.

  A relief valve 54 a is provided on the discharge side of the second pump 54. The relief oil from the relief valve 54 a is returned to the supply pipe 51 on the suction side of the first pump 52.

  The filter 55 is provided with a bypass 55a having a filter bypass valve 55b that bypasses the oil at low temperatures where the fluidity of the oil is low, and a pop-up indicator 55c that detects clogging of the filter 55.

  Further, on the downstream side of the air-containing oil outlet of the second air separator 57 of the supply pipe 51, a part of the oil containing air is supplied to the negative G hour supply pipe 61 on the suction side of the negative G hour pump 62. A return pipe 58 is provided to return to (1). A pressure regulating valve 58a is interposed in the return pipe 58 so that the pressure is constant. That is, an oil circulation system for circulating a part of the oil discharged from the second pump 54 is provided. In this way, by raising a part of the oil from the second air separator 57 to the supply pipe 51 on the suction side of the second pump 54 and circulating it, the temperature rise of the oil is promoted.

  The hydraulic circuit 10 to the hydraulic servo mechanism 3 is specifically a servo valve that branches from a second air separator 57 interposed in the supply pipe 51 and supplies oil from which air has been separated and removed to the servo valve 3a. Pipe 11, drive oil supply pipe 12 for supplying drive oil from the servo valve 3 a to the hydraulic cylinder 2 a of the tilt angle adjusting mechanism 2, and drive oil return for returning the drive oil from the hydraulic cylinder 2 a to the servo valve 3 a The pipe 13 is provided as a main part. The drive oil supply pipe 12 and the drive oil return pipe 13 are determined by the operating direction of the hydraulic cylinder 2a. That is, the pipe that has functioned as the drive oil supply pipe 12 when the piston of the hydraulic cylinder 2a advances functions as the drive oil return pipe 13 when the piston moves backward.

  As shown in FIG. 6, the servo valve 3 a includes a spool valve 3 b having a spool and a spool valve driving unit 3 c that slides the spool and adjusts its position.

  The spool valve drive unit 3c adjusts the back pressure of the spool valve 3b to slide the spool, thereby adjusting the position of the spool. Specifically, the spool valve drive unit 3c includes a flapper that adjusts the back pressure of the spool valve 3b, an amateur integrated with the flapper, and an electromagnetic drive mechanism that displaces the amateur. An example of the servo valve 3a configured as described above is a servo valve manufactured by MOOG.

  In addition, the servo valve 3a is null biased, that is, a safety mechanism is provided, and when the command value to the servo valve 3a is zero or the power is turned off, the gear ratio (generator rotation speed is set). The value divided by the engine speed) brings the generator speed to a safe speed. That is, the armature is mechanically given a certain initial inclination so that the flapper moves the spool in the direction in which the gear ratio decreases. In addition, as a result, the speed ratio is reduced to the minimum speed ratio or the minimum speed ratio side until the engine speed reaches the speed at which the hydraulic pressure is increased to a predetermined pressure and until the oil temperature rises to the predetermined temperature. It is possible to keep the generator speed on the safe side.

  The servo valve pipe 11 is provided with a hydraulic pump 14 for boosting the oil supplied to the servo valve 3a to a predetermined pressure and a filter 15 in this order from the branch point side (that is, upstream side). The filter 15 is used to prevent dust from entering the servo valve 3a.

  In the servo valve pipe 11 on the discharge side of the hydraulic pump 14, a relief valve 16 is provided to adjust the pressure of the pipe 11, and the relief oil from the relief valve 16 is supplied to the second air separator 57. It is returned to the supply pipe 51 on the upstream side. By returning the relief oil to the upstream side of the second air separator 57, the temperature rise of the oil at a low temperature where the fluidity of the oil is poor is promoted, and the oil from which the air has been removed even in the weightless state is used for the servo valve. The tube 11 can be supplied. The filter 15 is provided with a filter pop-up indicator 15a.

  Further, on the downstream side of the servo valve pipe 11 where the filter 15 is provided, a warm fuse valve 21 having a flow fuse valve 21 is used to warm the servo valve 3a by spraying heated oil onto the servo valve 3a. A machine pipe 20 is provided.

  The oil discharge pipe 18 for discharging the oil from the servo valve 3a is configured so that the oil from the servo valve 3a is returned to the normal time oil tank 41a.

  Therefore, in the oil system 30 having such a configuration, oil is normally supplied in the direction indicated by the arrow in FIG. 4, and the hydraulic servo mechanism 3 is controlled by the hydraulic circuit 10 to adjust the tilt angle of the power roller. Thus, the gear ratio control of the continuously variable transmission 1 is performed, while oil is supplied in the direction indicated by the arrow in FIG. 5 when minus G, and the hydraulic servo mechanism 3 is controlled by the hydraulic circuit 10 to tilt the power roller. The gear ratio of the continuously variable transmission 1 is controlled by adjusting the angle.

  As shown in FIGS. 1 and 2, the control device C includes a start-time control unit PC that controls the start-up of the hydraulic drive system A and safety means F. The safety means F constantly monitors the increase in the generator rotational speed regardless of the temperature, and when the abnormality is detected, the safety means F quickly brings the position of the power roller of the continuously variable transmission 1 toward the safe side, that is, It is supposed that the generator rotational speed is quickly shifted to the low rotational speed side.

  The start-time control unit PC includes a normal start control unit 70 that performs start-up control at normal temperature when the oil temperature is equal to or higher than a predetermined temperature, a low-temperature start control unit 80 that performs start-up control at low temperatures, and temperature sensors Ti, A timed start control unit 90 that performs start control by timed management when both To are abnormal is provided.

  Accordingly, the engine speed, the oil temperature detection signal from the temperature sensors Ti and To, and the generator speed are input to the control device C.

  Here, as shown in FIG. 2A, the normal start control unit 70, the low temperature start control unit 80, and the timed start control unit 90 perform start control by so-called open loop control.

  That is, the normal start control unit 70 is configured so that the position of the power roller does not exceed the neutral position and the generator rotational speed does not approach an unsafe rotational speed until the engine rotational speed reaches the specified rotational speed. The command value to 3 is controlled. That is, the command value of the hydraulic servo mechanism 3 is controlled so that the continuously variable transmission 1 is held at the minimum speed ratio (or the minimum speed ratio side).

  The low temperature start control unit 80 instructs the hydraulic servo mechanism 3 so that the position of the power roller does not exceed the neutral position and the generator rotational speed does not approach an unsafe rotational speed until the oil temperature rises to a predetermined value. Value shall be controlled. That is, the command value of the hydraulic servo mechanism 3 is controlled so that the continuously variable transmission 1 is held at the minimum speed ratio (or the minimum speed ratio side).

  Even when the timed start control unit 90 cannot use the signals from the temperature sensors Ti and To and cannot detect the oil temperature, the timed start control unit 90 can be operated for several minutes at a high engine speed. Since the oil temperature is assumed to have been sufficiently raised, the position of the power roller is at the minimum speed ratio (for example, 3 minutes) at a predetermined rotation speed (for example, 4500 RPM or more) with a sufficiently high engine rotation speed (for example, 3 minutes). Alternatively, the command value of the hydraulic servo mechanism 3 is controlled so as to be maintained at the minimum gear ratio side). That is, the start control is performed by timed management.

  In the timed control of the timed start control unit 90, when the generator speed reaches a specified speed (overspeed exceeding the rated speed (for example, 26400 rpm)), the generator speed is set by the safety means F. A process for moving toward the safe side, that is, the low speed side is performed.

  Hereinafter, the start control by the start-time control unit PC configured as described above will be described with reference to FIG. In addition, the code | symbol S1-S10 in a figure shows a procedure number.

  Procedure 1: Check each sensor for abnormalities. (S1) That is, it is checked whether the temperature sensors Ti and To, the engine speed sensor, and the generator speed sensor provided before and after the oil cooler 56 are abnormal. Here, the abnormality of the temperature sensors Ti and To is detected by, for example, arithmetic processing.

  That is, after the power supply of the control device C is turned on, the signals from the temperature sensors Ti and To are taken for a specified time, the connection resistance of the signal path is calculated based on the signals, and the value is infinite, judge. Conversely, if the value is zero, it is determined that a short circuit has occurred. Further, the intensity change rate of the captured signal is measured for a specified time, and if the change rate exceeds a threshold value, it is determined that noise is mixed.

  In the following description, it is assumed that there is no abnormality in the engine speed sensor and the generator speed sensor.

  Procedure 2: The engine speed is detected. (S2)

  Procedure 3: If it is determined that there is no abnormality in the temperature sensor Ti, the process proceeds to Procedure 5, and if it is determined that there is an abnormality, the process proceeds to Procedure 4. (S3)

  Procedure 4: When it is determined that there is no abnormality in the temperature sensor To, the procedure proceeds to procedure 5, and when it is determined that there is an abnormality, the procedure proceeds to procedure 7. (S4)

  Step 5: The oil temperature is detected by a normal temperature sensor (temperature sensor Ti or temperature sensor To) to determine whether the oil temperature exceeds a predetermined temperature (first reference temperature). If it does not exceed the temperature, the procedure proceeds to step 6. If the oil temperature exceeds the first reference temperature, the procedure proceeds to procedure 8. (S5) Here, the first reference temperature is, for example, −10 ° C. to 0 ° C.

  Procedure 6: Start control by the low temperature start control unit 80 and return to Procedure 1. (S6) During this starting control, oil is circulated and the oil temperature rises.

Step 7: The timed control by the timed start control unit 90 is performed, and the process proceeds to the normal control of step 10. (S7)
Procedure 8: The normal start control by the normal start control unit 70 is performed. (S8) During this start control, oil is circulated and the oil temperature rises.

  Step 9: It is determined whether the engine speed has reached the specified speed. If the engine speed has reached the specified speed, the routine proceeds to the normal control in step 10, and the engine speed reaches the specified speed. If not, return to step 1. (S9) Here, the specified rotational speed is, for example, 500 rpm.

Step 10: Perform feedback control by normal control (see FIG. 2B). (S10)
As described above, in the first embodiment, a null bias is applied to the servo valve 3a of the hydraulic servo mechanism 3 that drives the continuously variable transmission 1 so that the gear ratio is lowered, and the control unit C includes a start time control unit. Since a PC is provided to control the continuously variable transmission 1 so that the speed ratio of the continuously variable transmission 1 is maintained at the minimum speed ratio or the minimum speed ratio for a predetermined period from the start, there is no risk of unstable control at the start, and power generation The machine is also maintained in a safe state with a low rotational speed.

  Further, since the timed start control unit 90 is provided, it is possible to start normally even if both the temperature sensors Ti and To are abnormal.

Embodiment 2
FIG. 8 is a functional block diagram showing a control system for a continuously variable transmission to which a control method for a toroidal continuously variable transmission (hereinafter simply referred to as a continuously variable transmission) according to Embodiment 2 of the present invention is applied. 2 shows a control block diagram.

  The control system S1 is obtained by modifying the low-temperature start control unit 80 of the first embodiment. The low-temperature start control unit 80A of the start-time control unit PC1 includes a primary start control unit 81 and a gear ratio command limiting unit 83. The secondary start control means 82 having the above is provided. Although the low temperature start control unit 80 of the first embodiment is configured only for open loop control, the low temperature start control unit 80A of the second embodiment includes both open loop control and closed loop control, as will be described later. It is set as the structure.

  Hereinafter, the difference between the second embodiment and the first embodiment will be mainly described.

  As shown in FIG. 2A, the primary start control means 81 performs open-loop control of the hydraulic drive system A for a certain period immediately after the start of engine start.

  As shown in FIG. 2 (b), the secondary start control means 82 is in a state where the primary start control by the primary start control means 81 is completed and the engine speed exceeds the specified speed, and the hydraulic drive system A Is controlled by closed loop control, so-called feedback control.

  The gear ratio command limiting unit 83 limits the sudden change of the gear ratio command value in the secondary start control unit 82.

  Hereinafter, the contents of the control by the low-temperature start control unit 80A configured as described above will be described.

  FIG. 9 shows the contents of control by the primary start control means 81.

  As shown in FIG. 9, the primary start control means 81 controls the current command to the hydraulic servo mechanism 3 so that the hydraulic servo mechanism 3 reciprocates so that the speed increase command and the deceleration command alternate. In other words, the primary start control means 81 issues a reciprocating command to the hydraulic servo mechanism 3. The reason for this is to replace the oil in the servo valve 3a to promote warm-up of the servo valve 3a.

  In this reciprocation command, for example, the acceleration command value is set to be slightly larger than the neutral position of the servo valve 3a by the null bias correction so that the position of the power roller does not exceed the neutral position and shift to the acceleration side. The deceleration command value is set to a value slightly smaller than the neutral position of the servo valve 3a by the null bias correction (see FIGS. 9A and 9B). Thereby, the continuously variable transmission 1 is always maintained at the maximum deceleration or maximum deceleration side, that is, the minimum transmission ratio or minimum transmission ratio side (see FIG. 9C).

  Accordingly, when the control by the primary start control means 81 is performed for a certain period of time and the oil temperature rises, and the engine speed exceeds the specified speed, the control by the secondary start control means 82 is shifted to. . Here, the predetermined period is, for example, a period until the oil temperature detected by the hydraulic servo mechanism 3 exceeds a threshold, and the engine speed can increase the oil pressure to a predetermined pressure (for example, 4 MPa). It is a period until it reaches. The threshold value of the oil temperature is a temperature at which the oil becomes a predetermined viscosity due to a decrease in its viscosity and can be feedback-controlled without hindrance (hereinafter referred to as an intermediate temperature), for example, 0 ° C. to 30 ° C.

  The secondary start control means 82 feedback-controls the continuously variable transmission 1 so that the actual gear ratio becomes the gear ratio command until the oil temperature is raised to a high temperature (for example, 30 ° C.). In this case, if there is a significant variation in the gear ratio command, the oil fluidity is not sufficient, and control instability may occur. Therefore, the gear ratio command limiting means 83 sets a predetermined rate of change in the gear ratio command. There are restrictions. That is, so-called rate control is performed on the gear ratio command.

  Here, as shown in FIG. 10, the restriction may be adjusted stepwise as the oil temperature rises. For example, when the oil temperature at the beginning of the transition is 0 ° C. or lower (hereinafter referred to as the transition initial temperature), the transmission ratio rate is tightened, that is, the change ratio of the transmission ratio command is limited to a small value, When the temperature is between 0 ° C. and 30 ° C. (hereinafter referred to as the transition intermediate temperature), the transmission ratio rate is set to medium, that is, the change rate of the transmission ratio command is limited to a medium value, and the oil temperature at the end of the transition When the temperature is 30 ° C. or higher (hereinafter referred to as the transition end temperature), the speed ratio rate may be made gentle, that is, the restriction on the change rate of the speed ratio command may be greatly relaxed. In this case, the gear ratio rate between the transition initial temperature and the transition intermediate temperature and the gear ratio rate between the transition intermediate temperature and the transition end temperature may be determined by linear interpolation.

  FIG. 11 and FIG. 12 show an example of a control result by the low temperature start control unit 80A having such a configuration.

  In FIG. 11, the primary start control by the primary start control means 81 and the normal start control through the secondary start control means 82 are continued, assuming that the engine speed exceeds the specified speed. (A) shows the relationship between the current command value to the servo valve 3a and the position of the power roller, and (b) shows the relationship between the engine speed and the generator speed. (C) shows the relationship between the gear ratio command and the actual gear ratio. In the secondary starting control, rate control by the gear ratio command limiting means 83 is performed.

  FIG. 12 is a graph of the transition from the primary start control to the secondary start control. FIG. 12 (a) shows an overall view, FIG. 12 (b) shows an enlarged view of the first half, and FIG. 12 (c). Shows an enlarged view of the latter half.

  As shown in FIGS. 11 and 12, in the primary starting control, the servo valve 3a reciprocates, but the position of the power roller is set so as not to bring the generator rotational speed to an unsafe rotational speed. ing.

  Hereinafter, the start control by the start time control unit PC1 configured as described above will be described with reference to FIG. In addition, the code | symbol S1-S12 in a figure shows a procedure number.

  Procedure 1: Check each sensor for abnormalities. (S1) The following description will be made assuming that there is no abnormality in the engine speed sensor and the generator speed sensor.

  Procedure 2: The engine speed is detected. (S2)

  Procedure 3: If it is determined that there is no abnormality in the temperature sensor Ti, the process proceeds to Procedure 5, and if it is determined that there is an abnormality, the process proceeds to Procedure 4. (S3)

  Procedure 4: When it is determined that there is no abnormality in the temperature sensor To, the procedure proceeds to procedure 5, and when it is determined that there is an abnormality, the procedure proceeds to procedure 10. (S4)

  Step 5: The oil temperature is detected by a normal temperature sensor (temperature sensor Ti or temperature sensor To) to determine whether the oil temperature exceeds the second reference temperature, and the oil temperature exceeds the second reference temperature. If not, that is, if the oil temperature is low, the process proceeds to step 6. On the other hand, if the oil temperature exceeds the second reference temperature, that is, if the oil temperature is medium to high (for example, 0 ° C. or higher), the process proceeds to step 7. To do. (S5)

  Procedure 6: Performs primary start control by the primary start control means 81 and returns to Procedure 1. (S6) The servo valve 3a is warmed up by the primary start control, and the oil is circulated to increase the oil temperature.

  Step 7: The normal start control by the normal start control unit 70 is performed, and the procedure proceeds to Step 8. (S7) During this starting control, oil is circulated and the oil temperature rises.

  Step 8: Determine whether the engine speed has reached the specified speed. If the engine speed has reached the specified speed, go to Step 9 and the engine speed must have reached the specified speed. Return to step 1. (S8) Here, the specified rotational speed is, for example, 500 rpm.

  Step 9: It is determined whether the oil temperature exceeds the third reference temperature. If the oil temperature does not exceed the third reference temperature, that is, if the oil temperature is medium temperature, the procedure proceeds to Step 11, and the oil temperature is set to the third reference temperature. If it exceeds, that is, if the oil temperature is high, the routine proceeds to the normal control in step 12. (S9)

  Step 10: The timed start control unit 90 performs timed control and shifts to the normal control of step 12. (S10)

  Step 11: Perform secondary start control by the secondary start control means 82 and return to Step 1. That is, feedback control of the gear ratio of the continuously variable transmission 1 is performed and the procedure returns to step 1. (S11) In this case, the restriction of the change rate of the gear ratio command by the gear ratio command restriction means 83 in the secondary start control is relaxed as the oil temperature rises.

Procedure 12: Perform feedback control by normal control. (S12)
As described above, in the second embodiment, a predetermined viscosity cannot be obtained because the temperature of oil for controlling the servo valve 3a is low, such as in a cold region, and the hydraulic servo mechanism 3 has a desired control performance when the engine is started. If this is not ensured, the servo valve 3a is warmed up by a current command to reciprocate the spool within a range where the position of the power roller does not shift to the speed increasing side, preventing unnecessary long-term start-up in cold regions. Is done. In addition, since the restriction on the change rate of the gear ratio command is relaxed in accordance with the increase in the oil temperature, quick start-up can be performed while avoiding control instability.

  As mentioned above, although this invention has been demonstrated based on embodiment, this invention is not limited only to this embodiment, A various change is possible. For example, in the embodiment, the engine is described as an example, but the engine can be various prime movers, for example, a motor. The generator can also be various rotating machines, for example, a blower.

  The present invention can be applied to control of a toroidal type continuously variable transmission.

It is a functional block diagram of a control system concerning Embodiment 1 of the present invention. It is a control block diagram of the control system. It is an oil system diagram of the control system. It is a perspective view of the same oil system diagram, and shows the flow of oil in normal time. It is a perspective view of the same oil system diagram, and shows the flow of oil at minus G. It is the schematic of the servo valve used for the control system. It is a flowchart of control concerning Embodiment 1 of the present invention. It is a functional block diagram of a control system concerning Embodiment 2 of the present invention. It is a graph which shows the control content of the primary starting control means of the control system, wherein (a) shows the servo current command, (b) shows the position of the power roller, and (c) shows the gear ratio. Show. It is a graph which shows the relationship between oil temperature and gear ratio command, Comprising: (a) shows the relationship between oil temperature and time, (b) shows the relationship between gear ratio command and time. It is a graph of the control result by a primary starting control means and a secondary starting control means, Comprising: (a) shows the relationship between the electric current command value to the servo valve 3a, and the position of a power roller, (b) shows an engine. The relationship between the rotational speed and the generator rotational speed is shown, and FIG. 10C shows the relationship between the transmission ratio command and the actual transmission ratio. It is a graph of the transition part from primary starting control to secondary starting control, Comprising: (a) shows the whole figure, (b) shows the enlarged view of the first half part, (c) shows the latter half part. An enlarged view is shown. It is a flowchart of the control which concerns on Embodiment 2 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Continuously variable transmission 2 Tilt angle adjustment mechanism 3 Hydraulic servo mechanism 3a Servo valve 10 Hydraulic circuit 30 Oil system 40 Housing 41 Oil tank 50 Main line 70 Normal start control part 80 Low temperature start control part 81 Primary start control means 82 2 Next start control means 83 Gear ratio command limiting means 90 Timed start control part C Controller F Safety means PC Start time control part S Control system

Claims (16)

A control method for a continuously variable transmission comprising a hydraulic servomechanism disposed in an oil system having a pump driven by an output shaft of a prime mover,
The hydraulic servo mechanism includes a safety mechanism that brings the rotational speed of the rotating machine to a safe rotational speed,
Determine whether the oil temperature exceeds the reference temperature,
If the oil temperature exceeds the reference temperature, the power roller of the continuously variable transmission will reduce the rotation machine rotation speed until the motor rotation speed reaches the rotation speed at which the hydraulic pressure is increased to a predetermined pressure by normal start control. A control method for a continuously variable transmission, wherein the hydraulic servomechanism is controlled so as not to reach an unsafe rotational speed position.   If the oil temperature does not exceed the reference temperature, until the oil temperature exceeds the reference temperature, the position where the power roller of the continuously variable transmission brings the rotating machine rotation speed to an unsafe rotation speed by low temperature start control. 2. The continuously variable transmission control method according to claim 1, wherein the hydraulic servomechanism is controlled so as not to occur. A control method for a continuously variable transmission comprising a hydraulic servomechanism disposed in an oil system having a pump driven by an output shaft of a prime mover,
The hydraulic servo mechanism includes a safety mechanism that brings the rotational speed of the rotating machine to a safe rotational speed,
Determine whether the oil temperature exceeds the first reference temperature,
If the oil temperature does not exceed the first reference temperature, the spool of the servo valve of the hydraulic servomechanism is controlled by the primary start control, and the power roller of the continuously variable transmission reduces the rotational speed of the rotating machine to an unsafe speed. A control method for a continuously variable transmission, wherein the reciprocating motion is performed while avoiding a position approaching the vehicle.   If the oil temperature exceeds the first reference temperature, the power roller of the continuously variable transmission is rotated by the normal start control until the motor speed reaches the speed at which the hydraulic pressure is increased to a predetermined pressure. 4. The continuously variable transmission control method according to claim 3, wherein the hydraulic servo mechanism is controlled so that the rotational speed is not brought to a position where the rotational speed is brought to an unsafe rotational speed.   If the motor speed exceeds the speed at which the hydraulic pressure is increased to a predetermined pressure, and the oil temperature does not exceed the second reference temperature, the speed change ratio of the continuously variable transmission is limited by the secondary start control. 4. The method for controlling a continuously variable transmission according to claim 3, wherein feedback control is performed.   6. The continuously variable transmission control method according to claim 5, wherein the restriction on the change rate of the transmission ratio is relaxed as the oil temperature increases.   The oil temperature is detected by a plurality of temperature sensors, and the start control is performed based on one of the detected values. When the temperature sensor used for the control becomes abnormal, the control is performed by switching to the other temperature sensor. The method for controlling a continuously variable transmission according to claim 1, 2, 3, 4, 5 or 6.   8. The control method for a continuously variable transmission according to claim 7, wherein when all of the plurality of temperature sensors become abnormal, start control is performed by timed management.   A process for bringing the rotational machine speed to the safe side when the rotational speed of the rotating machine exceeds the specified rotational speed and becomes an excessive rotational speed is performed. 7. A method for controlling a continuously variable transmission according to claim 7 or 8.   The motor is an engine, the rotating machine is a generator, and the safety mechanism is a null bias of a servo valve, wherein the servo valve is a null bias. The control method of the continuously variable transmission as described. A control system for a continuously variable transmission comprising a control device and a hydraulic servomechanism disposed in an oil system having a pump driven by an output shaft of a prime mover,
The hydraulic servo mechanism includes a safety mechanism that brings the rotational speed of the rotating machine to a safe rotational speed,
The control device includes a start time control unit having a normal start control unit and a low temperature start control unit,
If the oil temperature exceeds the reference temperature, the normal start control unit determines that the power roller of the continuously variable transmission has an unsafe rotational speed until the prime mover rotational speed reaches a specified rotational speed. The hydraulic servo mechanism is controlled so as not to reach the position
If the oil temperature does not exceed the reference temperature, the low-temperature start control unit is a position where the power roller of the continuously variable transmission brings the rotating machine rotation speed to an unsafe rotation speed until the oil temperature exceeds the reference temperature. A control system for a continuously variable transmission, wherein the hydraulic servomechanism is controlled so as not to become. A control system for a continuously variable transmission comprising a control device and a hydraulic servomechanism disposed in an oil system having a pump driven by an output shaft of a prime mover,
The hydraulic servo mechanism includes a safety mechanism that brings the rotational speed of the rotating machine to a safe rotational speed,
The control device includes a start time control unit having a normal start control unit and a low temperature start control unit,
The low temperature start control unit includes a primary start control means and a secondary start control means having a gear ratio command limiting means,
If the oil temperature exceeds the first reference temperature, the normal start control unit causes the power roller of the continuously variable transmission to unsafely rotate the rotational machine speed until the prime mover rotational speed reaches a specified rotational speed. The hydraulic servomechanism is to be controlled so that it does not reach a position where the rotational speed is approached.
If the oil temperature does not exceed the first reference temperature, the primary start control means causes the spool of the servo valve of the hydraulic servo mechanism and the power roller of the continuously variable transmission to unsafely rotate the rotating machine. It shall be controlled to reciprocate while avoiding the position approaching the rotational speed,
The secondary start control means is configured to control the continuously variable transmission according to the secondary start control unless the motor speed exceeds the speed at which the hydraulic pressure is increased to a predetermined pressure and the oil temperature does not exceed the second reference temperature. A control system for a continuously variable transmission, wherein the transmission ratio is feedback-controlled while limiting the rate of change. The start time control unit includes a timed start control unit,
13. The continuously variable transmission control system according to claim 11, wherein the timed start control unit performs start control by timed management. The control device is equipped with safety means,
12. The safety means is configured to perform a process of bringing the rotational speed of the rotating machine to the safe side when the rotational speed of the rotating machine exceeds the specified rotational speed and becomes an excessive rotational speed. , 12 or 13 continuously variable transmission control system.   15. The continuously variable transmission control system according to claim 11, 12, 13 or 14, wherein the prime mover is an engine, the rotary machine is a generator, and the safety mechanism is a null bias of a servo valve.   A rotary machine device comprising the control system for a continuously variable transmission according to any one of claims 11 to 14.