JP2009210110A - Clutch control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To estimate the temperature of an electromagnetic coil in an electromagnetic actuator, without arranging a temperature sensor, and without hindering engaging/releasing operation of a clutch. <P>SOLUTION: A clutch control device controls engagement and a release of an electromagnetic clutch having mutually engaging engagement parts by the electromagnetic actuator having a coil. The electromagnetic actuator is driven by carrying an electric current to the coil, and engages and releases by moving the engaging part of the electromagnetic clutch. An engagement control means controls engagement and a release of the electromagnetic clutch by controlling the electromagnetic actuator by making a feedback process. A coil temperature estimating means estimates the temperature of the coil while controlling the electromagnetic actuator while processing a feedforward control. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a clutch control device that controls engagement of an electromagnetic clutch by driving an electromagnetic actuator.

  2. Description of the Related Art An electromagnetic clutch that controls engagement and release of a clutch by driving an electromagnetic actuator is known. In the electromagnetic clutch, there is a problem that the electromagnetic clutch is in a heated state when a certain torque or more is continuously applied. For this reason, it is required to detect or estimate the temperature of the electromagnetic clutch.

  Regarding the estimation of the temperature of the clutch, Patent Document 1 calculates the input energy applied to the electronically controlled clutch from the clutch rotational speed difference and the clutch transmission torque, and predicts the fluctuation of the clutch temperature according to the magnitude of the input energy. A method for calculating the estimated clutch temperature is described.

  Patent Document 2 describes a clutch control method in which a large current is applied when the clutch is engaged and a small current is switched when the clutch is held.

JP 2002-168270 A JP-A-5-157129

  In the clutch temperature estimation device described in Patent Document 1, the temperature of the clutch portion can be estimated, but the temperature of the electromagnetic coil portion inside the electromagnetic actuator cannot be detected and estimated. On the other hand, providing a dedicated temperature sensor for detecting the temperature of the electromagnetic coil part causes an increase in cost. In the clutch control device disclosed in Patent Document 2, no consideration is particularly given to the temperature rise.

  SUMMARY OF THE INVENTION An object of the present invention is to estimate the temperature of an electromagnetic coil in an electromagnetic actuator without providing a temperature sensor and without affecting the engagement / release operation of a clutch.

  In one aspect of the present invention, a clutch control device that controls engagement of an electromagnetic clutch by controlling an electromagnetic actuator having a coil performs engagement control of the electromagnetic clutch by performing feedback control of the electromagnetic actuator. When the temperature of the coil is estimated, the control unit includes a coil temperature estimation unit that switches the feedback control to the feedforward control and estimates the coil temperature.

  The clutch control device controls the engagement and disengagement of the electromagnetic clutch including the engaging portions that are engaged with each other by an electromagnetic actuator having a coil. The electromagnetic actuator is driven by energizing the coil, and engages and releases by moving the engaging portion of the electromagnetic clutch. The engagement control means controls the engagement and release of the electromagnetic clutch by feedback controlling the electromagnetic actuator. The coil temperature estimation means estimates the coil temperature during feedforward control of the electromagnetic actuator.

  In one aspect of the clutch control device, the coil temperature estimating means includes a current value measuring means for measuring a current value applied to the coil, and a voltage for calculating an applied voltage value applied to the coil during feedforward control. Value calculating means, and an estimating means for calculating a resistance value of the coil based on the energizing current value and the applied voltage value, and estimating a temperature of the coil based on the resistance value.

  In this aspect, for example, a current value measuring means configured by a current sensor or the like measures the current value applied to the coil. Further, a voltage value applied to the coil during the feedforward control is calculated. The resistance value of the coil is calculated based on the energization current value of the coil and the applied voltage value. Since the coil resistance value is a function of the coil temperature, the coil temperature is estimated based on the calculated resistance value.

  In another aspect of the clutch control device described above, the coil temperature estimation unit rotates the electromagnetic clutch and confirms the engagement state of the electromagnetic clutch while performing feedforward control of the electromagnetic actuator. A confirmation means is provided. Thereby, the engagement of the electromagnetic clutch can be confirmed in parallel with the estimation of the temperature of the coil.

  In another aspect of the clutch control device described above, the engagement control unit obtains a holding current value necessary for maintaining the engagement state of the electromagnetic clutch after the temperature estimation by the coil temperature estimation unit as a target current. The feedback control is executed as a value. As a result, after the engagement of the clutch is completed, the engagement is maintained by the holding current value necessary for maintaining the engagement state, so that energy consumption for maintaining the engagement of the clutch can be saved. Can do.

  Preferred embodiments of the present invention will be described below with reference to the drawings.

[Configuration of power transmission mechanism of hybrid vehicle]
FIG. 1 shows a schematic configuration of a power transmission mechanism of a hybrid vehicle to which the clutch control device of the present invention is applied. The example of FIG. 1 is a hybrid vehicle called a mechanical distribution type two-motor type, and includes an engine 1, a first motor generator MG 1, a second motor generator MG 2, and a power distribution mechanism 20. An engine 1 corresponding to a power source and a first motor generator MG1 corresponding to a power source and rotation speed control mechanism are connected to a power distribution mechanism 20. The output shaft 3 of the power distribution mechanism 20 is connected to a second motor generator MG2 that is an auxiliary power source for assisting driving torque or braking force via the MG2 transmission 6. Further, the output shaft 3 is connected to the left and right drive wheels 9 via a final reduction gear 8. The first motor generator MG1 and the second motor generator MG2 are electrically connected via a battery, an inverter, or an appropriate controller (not shown) or directly, and the first motor generator MG1 The second motor generator MG2 is driven by the generated electric power.

  The engine 1 is a heat engine that generates power by burning fuel, and examples thereof include a gasoline engine and a diesel engine. The first motor generator MG1 generates power mainly by receiving torque from the engine 1 and rotating, and reaction force torque accompanying power generation acts. By controlling the rotational speed of first motor generator MG1, the rotational speed of engine 1 changes continuously. Such a shift mode is referred to as a “continuously variable mode”. The continuously variable transmission mode is realized by a differential action of a power distribution mechanism 20 described later.

  The second motor generator MG2 is a device that assists the driving torque or the braking force. When assisting the drive torque, the second motor generator MG2 receives power supply and functions as an electric motor. On the other hand, when assisting the braking force, the second motor generator MG2 functions as a generator that is rotated by the torque transmitted from the drive wheels 9 to generate electric power.

  FIG. 2 shows a configuration example of the first and second motor generators MG1 and MG2, the meshing electromagnetic clutch 70, and the power distribution mechanism 20 shown in FIG.

  The power distribution mechanism 20 is a mechanism that distributes the output torque of the engine 1 to the first motor generator MG1 and the output shaft 3, and is configured to generate a differential action. Specifically, the engine 1 is connected to the first rotating element among the four rotating elements that are provided with a plurality of sets of differential mechanisms and have a differential action, and the first motor generator MG1 is connected to the second rotating element. Are connected, the output shaft 3 is connected to the third rotating element, and the electromagnetic clutch 70 is connected to the fourth rotating element. In a state where the electromagnetic clutch 70 is released, the rotation speed of the engine 1 is continuously changed by continuously changing the rotation speed of the first motor generator MG1, and the continuously variable transmission mode is realized. On the other hand, when the electromagnetic clutch 70 is engaged and the fourth rotation element is fixed, the gear ratio determined by the power distribution mechanism 20 is fixed to the overdrive state (that is, the engine speed is smaller than the output speed). Thus, the fixed speed mode is realized. The electromagnetic clutch control device of the present invention controls the electromagnetic clutch 70.

  In the present embodiment, as shown in FIG. 2, the power distribution mechanism 20 is configured by combining two planetary gear mechanisms. The first planetary gear mechanism includes a ring gear 21, a carrier 22, and a sun gear 23, and the second planetary gear mechanism includes a ring gear 25, a carrier 26, and a sun gear 27.

  The output shaft 2 of the engine 1 is connected to the carrier 22 of the first planetary gear mechanism, and the carrier 22 is connected to the ring gear 25 of the second planetary gear mechanism. These constitute the first rotating element. The rotor 11 of the first motor generator MG1 is connected to the sun gear 23 of the first planetary gear mechanism, and these constitute a second rotating element.

  The ring gear 21 of the first planetary gear mechanism and the carrier 26 of the second planetary gear mechanism are connected to each other and to the output shaft 3. These constitute the third rotating element. The sun gear 27 of the second planetary gear mechanism corresponds to the fourth rotating element, and is connected to the dog tooth 72 of the pair of dog teeth 71 and 72 of the electromagnetic clutch 70.

  FIG. 3 schematically shows the configuration of the electromagnetic clutch 70. In this example, the electromagnetic clutch 70 includes an electromagnetic actuator 60 and a pair of dog teeth 71 and 72 meshed with each other. The dog teeth 71 constitute a fixed part, and the dog teeth 72 constitute a rotating part. Each dog tooth 71 and 72 includes a plurality of teeth 75.

  The electromagnetic actuator 60 is driven and controlled based on a signal output from an electromagnetic actuator drive circuit, which will be described later, and moves the dog teeth 71 on the rotating portion side in the direction of the arrow 122 to mesh with the dog teeth 72 on the fixed portion side. At the same time, the dog teeth 71 on the rotating portion side are moved in the direction opposite to the arrow 122 to release the engagement with the dog teeth 72 on the fixed portion side.

  FIG. 4 shows a configuration example of the electromagnetic clutch 70. The electromagnetic actuator 60 includes a shaft 61, a sliding bearing 62, a pair of plungers 63 and 64 made of a metal material, a yoke 65, a coil 66, a return spring 67, and a case 68.

  At least a part of the outer peripheral surface of the shaft 61 is provided with a sliding bearing 62 for moving one plunger 63 in a direction in which the other plunger 64 is engaged with the other plunger 64 and in the opposite direction (arrow Y1 direction). One plunger 63 is attached to the sliding bearing 62. The other plunger 64 has a shape that engages with one plunger 63, and is attached to the inside of the case 68 so as to face the one plunger 63. The yoke 65 is a magnetic body, for example, and is disposed outside the pair of plungers 63 and 64. A part of the yoke 65 is in contact with a part of the pair of plungers 63. The coil 66 is disposed between the yoke 65 and the pair of plungers 63 and 64, and power is supplied to the coil 66 through an electromagnetic actuator drive circuit. The return spring 67 is a push spring that is attached to a shaft 61 positioned between a part of one plunger 63 and the inside of the case 68 and acts in a direction in which one plunger 63 is pulled away from the other plunger 64. The case 68 is fixed to a vehicle body or the like, and houses a shaft 61, a sliding bearing 62, a pair of plungers 63 and 64, a yoke 65, a coil 66, and a return spring 67, respectively.

  As described above, when the electromagnetic clutch 70 is released (off), the continuously variable transmission mode is set. Specifically, the output torque of the engine 1 acts on the carrier 22 that is the first rotating element, and the reaction force torque by the first motor generator 23 acts on the sun gear 23 that is the second rotating element. A torque that rotates in the same direction as the engine 1 acts on the output shaft 3 that is the third rotation element and the sun gear 27 that is the fourth rotation element. In this case, the rotational speed of engine 1 changes according to the rotational speed change of first motor generator MG1, and the operation in the continuously variable transmission mode is performed.

  On the other hand, when the electromagnetic clutch 70 is in the engaged (on) state, the fixed speed mode is set. Specifically, when the rotation of the sun gear 27, which is the fourth rotation element, is stopped, a reaction torque is applied to the rotation of the engine 1 by the electromagnetic clutch 70. Therefore, the first motor generator MG1 is a so-called idle rotation. It becomes a state. As a result, the speed ratio determined by the configuration of the power distribution mechanism 20 is fixed, and the operation in the fixed speed mode is performed.

[Electromagnetic actuator drive circuit]
FIG. 5 shows a configuration example of the drive circuit 100 that drives the electromagnetic actuator 60. The drive circuit 100 of this example drives the electromagnetic actuator 60 by PWM (pulse width modulation). The drive circuit 100 performs electromagnetic control by current feedback control (hereinafter referred to as “FB control”) during the control of engagement and disengagement of the electromagnetic clutch 70 (hereinafter collectively referred to as “engagement control”). The actuator 60 is controlled. In addition, the drive circuit 100 performs an electromagnetic actuator by current feedforward control (hereinafter referred to as “FF control”) when estimating the temperature of the coil 66 inside the electromagnetic actuator 60 (hereinafter also referred to as “temperature estimation”). 60 is controlled.

  Specifically, during the engagement control of the electromagnetic actuator 60, the ECU 30 outputs an FB control PWM signal. This FB control PWM signal corresponds to a target current value for FB control. The averaging circuit 31 averages the FB control PWM signal and outputs a voltage corresponding to the target current value to the differential amplifier 33. The differential amplifier 33 is supplied with a voltage corresponding to the current value of the current applied to the coil 66 from the differential amplifier 41 described later. The differential amplifier 33 supplies the comparator 34 with the difference between the voltage corresponding to the FB control PWM signal (that is, the target current value) given from the ECU 30 and the voltage corresponding to the current energization current value. The comparator 34 generates a PWM signal indicating an energization current value to the coil 66 based on the output of the differential amplifier 33 and the triangular wave generated by the triangular wave generation circuit 32 and supplies the PWM signal to the changeover switch 35.

  As shown in the figure, a switching element (transistor element) 36, a coil (electromagnetic coil) 66, and a resistor 40 are connected in series between a power supply (Vcc) and a ground (GND). The output of the changeover switch 35 is input to the base of the switching element 36.

  During the engagement control of the electromagnetic actuator 60, the changeover switch 35 supplies the output of the comparator 34 to the switching element 36 based on a change command supplied from the ECU 30. As a result, the switching element 36 is turned on only during a period in which the PWM signal output from the comparator 34 is at a high level, and energizes the coil 66 of the electromagnetic actuator 60.

  A current sensor 38 is provided at one end of the coil 66. The current sensor 38 detects an energization current value for the coil 66 and supplies it to the ECU 30 via the amplifier 39. In this way, the ECU 30 acquires the energization current value of the coil 66. The coil 66 is grounded via a resistor 40, and a differential amplifier 41 is provided in parallel with the resistor 40. The differential amplifier 41 supplies the potential difference between both ends of the resistor 40 to the ECU 30 and also supplies it to the differential amplifier 33.

  On the other hand, when estimating the temperature of the coil 66 in the electromagnetic actuator 60, the ECU 30 supplies the FF control PWM signal to the changeover switch 35 as the target current value during the FF control. The target current value during FF control is set to a constant amount. The changeover switch 35 supplies the FF control PWM signal to the switching element 36 in response to a changeover command from the ECU 30 to turn on / off the switching element 36. Even during the FF control, the ECU 30 acquires the output of the current sensor 38 as the value of the energization current to the coil 66.

  Further, in order to estimate the coil temperature during the FF control, the ECU 30 calculates an applied voltage value applied to the coil 66 based on the duty ratio of the FF control PWN signal. Then, the ECU 30 calculates the resistance value of the coil 66 based on the applied voltage value and the energization current value of the coil 66 obtained from the current sensor 38. Since the resistance value of the coil 66 thus obtained is a function of the temperature of the coil 66, the ECU 30 estimates the temperature of the coil 66 based on the calculated resistance value of the coil 66. Specifically, a map showing the relationship between the resistance value of coil 66 and the temperature is prepared in advance, and ECU 30 refers to the map and estimates the temperature of coil 66 from the resistance value of coil 66.

  Thus, the reason why the temperature of the coil 66 is estimated while the electromagnetic actuator 60 is FF-controlled is as follows. As described above, the temperature of the coil 66 can be considered as a function of the resistance value of the coil 66. If the resistance value of the coil 66 can be obtained, the temperature of the coil 66 can be estimated. In order to obtain the resistance value of the coil 66, an applied voltage value and an energization current value of the coil 66 are required. Here, whether the electromagnetic actuator 60 is FB-controlled or FF-controlled, the ECU 30 can obtain the energization current value of the coil 66 by the current sensor 38. However, when the electromagnetic actuator 60 is FB-controlled, the applied voltage value of the coil 66 fluctuates due to the FB control, so that a sensor for detecting the applied voltage is required. On the other hand, when the electromagnetic actuator 60 is FF-controlled, the ECU 30 can calculate the applied voltage value of the coil 66 based on the duty ratio of the FF control PWM signal corresponding to the control target current value. There is no need to provide a sensor or the like for measuring the applied voltage value. Therefore, in this embodiment, the temperature of the coil 66 is estimated while the electromagnetic actuator 60 is FF-controlled.

  Next, a control example of the electromagnetic actuator 60 will be described. FIG. 6 is a timing chart showing an example of control of the electromagnetic actuator 60 by the drive circuit 100. In FIG. 6, the horizontal axis represents time, and the vertical axis represents the output state of the electromagnetic actuator 60, the output waveform of the switching element 36, the control mode of the electromagnetic actuator 60, and the energization current waveform of the coil 66.

  In FIG. 6, the output state of the electromagnetic actuator 60 is in the on state over the period of time t0 to t7, and the electromagnetic actuator 60 operates and the electromagnetic clutch 70 is in the engaged state. On the other hand, after time t7, the electromagnetic actuator output state is in the off state, and the electromagnetic clutch 70 is in the released state.

  The switching element output waveform indicates a PWM signal waveform for turning on / off the switching element 36, and a voltage value applied to the coil 66 is defined by a duty ratio of the PWM signal waveform. In this example, in a state in which the electromagnetic actuator 60 is driven to engage the electromagnetic clutch 70 (hereinafter referred to as “operation state”), the duty ratio is set to 80%. Therefore, in the operating state, 80% of the predetermined power supply voltage Vcc is applied to the coil 66. On the other hand, in the state in which the electromagnetic clutch 70 once engaged is kept engaged (hereinafter referred to as “holding state”), the duty ratio is set to 20%. Therefore, in the operating state, 20% of the power supply voltage Vcc is applied to the coil 66.

  The electromagnetic actuator control mode indicates whether the electromagnetic actuator 60 is FB controlled or FF controlled by the drive circuit 100. Normally, the electromagnetic actuator 60 is FB-controlled with an emphasis on current followability. In the example of FIG. 6, the electromagnetic actuator 60 is FB-controlled from the time t0 with the target current value I1 in the operating state (hereinafter referred to as “operating current value”) as a target. Thereby, the energization current value of the coil 66 increases toward the operating current value I1. When the state where the energization current value of the coil 66 is stable within the predetermined current value range continues for the specified time TP1 or more (time t1), the ECU 30 switches the FB control to the FF control and estimates the temperature of the coil 66. The “predetermined current value range” refers to a current value range that is greater than the current value I2 (hereinafter referred to as “holding current value”) in the holding state by a predetermined amount or more.

  As described above, during the FF control, the ECU 30 calculates an applied voltage value to the coil 66 based on the duty ratio of the PWM signal corresponding to the target current value. In addition, the ECU 30 detects the energization current value of the coil 66 by the current sensor 38. Specifically, the ECU 30 detects the current value of the stable period SP indicated by the broken line P in the coil energization current waveform of FIG. 6 as the energization current value. Then, the ECU 30 calculates the resistance value of the coil 66 based on the applied voltage value and the energization current value of the coil 66, and estimates the temperature of the coil 66 with reference to a map or the like based on the calculated resistance value.

  In FIG. 6, the change (decrease) ΔX in the coil energization current waveform between times t <b> 1 and t <b> 2 is due to the temperature increase of the coil 66. That is, when the temperature of the coil 66 rises while the applied voltage of the coil is maintained at a predetermined voltage value during the FF control, the resistance value of the coil 66 increases and the energization current of the coil 66 decreases.

  Thus, when the temperature estimation process of the coil 66 is completed, the ECU 30 returns the control mode of the electromagnetic actuator 60 to the FB control, and sets the target current value to the holding current value I2 (time t2 to t4). As a result, the coil energization current waveform gradually decreases to the holding current value I2 (time t3), and thereafter maintains the holding current value I2. Thereby, the engagement state of the electromagnetic clutch 70 is maintained.

  Thus, after the electromagnetic clutch 70 is maintained in the hold state, when the specified time TP2 has elapsed, the ECU 30 estimates the temperature of the coil 66 again. Specifically, at time t4 when the specified time TP2 has elapsed, the ECU 30 changes the target current value for FB control from the holding current value I2 to the operating current value I1. Thereby, the energization current value of the coil 66 increases. When the energizing current value of the coil 66 becomes close to the operating current value (time t5), the ECU 30 switches the electromagnetic actuator control mode from FB control to FF control (time t5), and the coil 66 is similar to the period from time t1 to t2. Temperature estimation. When the temperature estimation of the coil 66 is completed, the ECU 30 again changes the electromagnetic actuator control mode to FB control, and sets the target current value to the holding current value I2 (time t6).

  As described above, in this embodiment, after the ECU 30 engages the electromagnetic clutch 70 by the current FB control using the target current value as the operating current value, the energized current value of the coil 66 is stabilized within the predetermined current value range. Sometimes (time t1), the electromagnetic actuator control mode is switched to FF control, and the temperature of the coil 66 is estimated. At this time, by switching to FF control, the applied voltage value of the coil 66 at that time can be calculated based on the duty ratio of the FF control PWM signal corresponding to the target current value, and a sensor for detecting the applied voltage value Etc., the temperature of the coil 66 can be estimated. Further, after the temperature estimation is completed, energy consumption can be saved by lowering the target current value of the FB control to the holding current value.

  Further, the temperature estimation of the coil 66 is performed immediately after the electromagnetic clutch 70 is engaged as shown at times t1 to t2 in FIG. 6, and the engagement state of the electromagnetic clutch 70 is constant as shown at times t5 to t6. It is also executed periodically if it lasts longer than the time. In this case, with the electromagnetic clutch 70 engaged, the target current value is increased from the holding current value (for example, up to the operating current value), and then the electromagnetic actuator control mode is switched to FF control to perform similar temperature estimation. Execute the process. Thereby, when the engagement state of the electromagnetic clutch 70 continues for a long time, the temperature of the coil 66 can be periodically checked.

  Further, the engagement confirmation control of the electromagnetic clutch 70 may be further executed during the temperature estimation control period. Specifically, in the temperature estimation control period, the ECU 30 applies torque in the direction in which the dog teeth 72 constituting the electromagnetic clutch 70 are rotated in parallel with the temperature estimation of the coil 66 (the positive direction of rotation and the rotation direction). Torque is alternately applied in the reverse direction), and the engagement state of the electromagnetic clutch 70 is confirmed. If the electromagnetic clutch 70 is correctly engaged, the rotation angle of the dog teeth 72 when the torque is changed in the rotation direction is equal to or less than a predetermined value, but if the electromagnetic clutch 70 is disengaged, the rotation angle of the dog teeth 72. Becomes larger than a predetermined value. As a result, the engagement of the electromagnetic clutch 70 can be confirmed.

  Such engagement confirmation of the electromagnetic clutch 70 applies torque in the rotational direction of the electromagnetic clutch 70, and does not apply torque in the axial direction of the electromagnetic clutch 70 (the direction of the arrow 122 in FIG. 3). Therefore, the temperature estimation process of the coil 66 is not affected and can be executed simultaneously with the temperature estimation. Further, if this engagement confirmation process is executed while the electromagnetic clutch 70 is held, the electromagnetic clutch 70 may be disengaged when torque is applied in the rotational direction. On the other hand, if it is executed during the temperature estimation control period, since the electromagnetic clutch 70 is in an operating state, there is no fear that the electromagnetic clutch 70 is disengaged by applying torque for confirmation of engagement.

  FIG. 7 is a flowchart of electromagnetic clutch engagement control. This control is mainly executed by the ECU 30.

  First, the ECU 30 determines whether or not the electromagnetic clutch 70 is in a released state (step S101). When it is not in the released state, that is, when the electromagnetic clutch 70 is in the engaged state (step S101; No), step S101 is repeated. On the other hand, when the electromagnetic clutch 70 is in a released state (step S101; Yes), the ECU 30 determines whether or not the electromagnetic actuator 60 is normal (step S102). If the electromagnetic actuator 60 is not normal (step S102; No), the electromagnetic clutch 70 cannot be engaged, and the process returns to step S101. On the other hand, when the electromagnetic actuator 60 is normal (step S102; Yes), the ECU 30 determines whether or not the engagement instruction flag of the electromagnetic clutch 70 is on (step S103). Here, the case where the engagement instruction flag of the electromagnetic clutch 70 is ON is a case where traveling in the fixed stage mode is requested by engaging the electromagnetic clutch 70.

  If the engagement instruction flag of the electromagnetic clutch 70 is not on (step S103; No), the process returns to step S101. On the other hand, when the engagement instruction flag of the electromagnetic clutch 70 is on (step S103; Yes), the ECU 30 sets the electromagnetic actuator control mode to FB control, and operates the target current value in order to put the electromagnetic clutch 70 in the operating state. The current value is set (step S104).

  Next, the ECU 30 determines whether or not the energization current value of the coil 66 is within a predetermined current value range (step S105). As described above, the “predetermined current value range” refers to a current value range that has a margin greater than the specified current from the holding current of the electromagnetic clutch 70. This is because the temperature of the coil 66 is estimated only when there is a margin greater than the specified current from the holding current.

  When the energization current value of the coil 66 is outside the predetermined current value range (step S105; No), the process returns to step S104. On the other hand, when the energization current value of the coil 66 is within the predetermined current value range (step S105; Yes), the ECU 30 determines whether or not the state has exceeded the specified time TP1 (step S106). If it is less than the prescribed time TP1, the process returns to step S104. On the other hand, when the specified time TP1 or more has elapsed (step S106; Yes), the ECU 30 switches the electromagnetic actuator control mode to FF control, and estimates the temperature of the coil 66 by the method described above (step S107). That is, when estimating the coil temperature, the FB control is switched to the FF control to estimate the coil temperature. Further, the ECU 30 confirms the engagement of the electromagnetic clutch 70 (step S108). If the engagement confirmation result is not normal (step S108; No), the process returns to step S104.

  On the other hand, when the engagement confirmation result is OK (step S108; Yes), the ECU 30 determines whether or not the electromagnetic actuator is normal (step S109). Specifically, the ECU 30 determines whether or not the temperature of the coil 66 obtained by the temperature estimation performed in step S107 is in a normal temperature range. If the electromagnetic actuator 60 is not normal (step S109; No), the engagement of the electromagnetic clutch 70 cannot be maintained, so the ECU 30 releases the electromagnetic clutch 70 (step S110), and the process returns to step S101.

  On the other hand, when the electromagnetic actuator 60 is normal (step S109; Yes), the ECU 30 changes the electromagnetic actuator control mode to FB control (step S111), and sets the holding current value as the target current value (step S112).

  Next, the ECU 30 determines whether or not the specified time TP2 has elapsed since the electromagnetic actuator control mode was changed to FB control in step S111 (step S113). If the specified time TP2 has not elapsed (step S113; No), the process returns to step S112, and the holding state of the electromagnetic clutch 70 is continued. On the other hand, when the specified time TP2 has elapsed (step S113; Yes), the ECU 30 changes the target current value to the operating current value (step S114), switches the electromagnetic actuator control mode to FF control, and changes the temperature of the coil 66. Estimation is performed (step S115). The case where the specified time TP2 has elapsed corresponds to the case where the engagement state of the electromagnetic clutch 70 continues for a certain time or more. When the temperature estimation ends, the ECU 30 changes the electromagnetic actuator control mode to the FB control, and gives an instruction to set the target current value as the holding current value (step S116). Thereby, the holding state of the electromagnetic actuator 60 is maintained.

  As described above, in the present invention, the temperature of the coil is estimated based on the resistance value of the coil during the engagement control of the electromagnetic clutch, so that it is not necessary to provide a temperature sensor for detecting the temperature of the coil. In addition, it is necessary to acquire the applied voltage value of the coil in order to calculate the resistance value of the coil, but the applied voltage value is calculated based on the target value of the FF control, so that a sensor that detects the applied voltage value of the coil, etc. There is no need to provide. In addition, since the coil temperature is estimated by temporarily performing FF control in the operating state after the electromagnetic clutch is engaged, the coil temperature can be estimated without affecting the engagement state of the electromagnetic clutch. it can. Further, when performing the electromagnetic clutch engagement confirmation control, it can be performed simultaneously with the coil temperature measurement.

The schematic structure of the power transmission mechanism of the hybrid vehicle which concerns on this embodiment is shown. The structure of a motor generator, a clutch mechanism, and a power distribution mechanism is shown. 1 shows a schematic configuration of an electromagnetic clutch. It is sectional drawing of the structural example of an electromagnetic clutch. It is a block diagram which shows the structure of an electromagnetic actuator drive circuit. It is a timing chart which shows the engagement control example of an electromagnetic clutch. It is a flowchart of electromagnetic clutch engagement control.

Explanation of symbols

1 Engine 20 Power distribution mechanism 30 ECU
36 switching element 38 current sensor 60 electromagnetic actuator 66 coil 70 electromagnetic clutch 71, 72 dog tooth 100 electromagnetic actuator drive circuit

Claims (4)

A clutch control device that controls engagement of an electromagnetic clutch by controlling an electromagnetic actuator having a coil,
Engagement control means for controlling the engagement of the electromagnetic clutch by feedback controlling the electromagnetic actuator;
A clutch control device comprising: coil temperature estimation means for estimating the coil temperature by switching feedback control to feedforward control when estimating the coil temperature. The coil temperature estimation means includes
Current value measuring means for measuring a current value applied to the coil;
Voltage value calculating means for calculating an applied voltage value applied to the coil during feedforward control;
The clutch control device according to claim 1, further comprising: an estimation unit that calculates a resistance value of the coil based on the energization current value and the applied voltage value and estimates a temperature of the coil based on the resistance value.   3. The engagement confirmation unit according to claim 1, further comprising an engagement confirmation unit configured to rotate the electromagnetic clutch and confirm an engagement state of the electromagnetic clutch while the coil temperature estimation unit performs feedforward control of the electromagnetic actuator. Clutch control device.   The said engagement control means performs the said feedback control by making into a target electric current the holding current value required in order to maintain the engagement state of the said electromagnetic clutch after the temperature estimation by the said coil temperature estimation means. 4. The clutch control device according to any one of 3.

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