JP2016053325A - Variable valve timing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure operation of an electromagnetic type actuator in a low-temperature condition in a variable valve timing device.SOLUTION: The variable valve timing device has an ECU with a warm-up mode of applying a current to a coil of the actuator before start-up of an internal combustion engine to heat the coil, whereby the heat generated by the coil can prevent freeze-up inside the actuator or hydraulic oil from having a high viscosity before the start-up of internal combustion engine. Thus, operation of the actuator is secured in a low-temperature condition.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a variable valve timing device (hereinafter sometimes referred to as a variable valve device) mounted on a vehicle.

  Conventionally, the opening / closing timing of at least one of an intake valve and an exhaust valve of an internal combustion engine (hereinafter sometimes simply referred to as “valve”) is advanced for the purpose of improving fuel consumption, reducing exhaust emission, and improving output. A variable valve device that can be retarded or retarded is mounted on a vehicle (see, for example, Patent Document 1).

The variable valve device rotates a predetermined rotating body with hydraulic pressure to advance or retard the valve opening / closing timing, and includes the following hydraulic control valve, electromagnetic actuator, and control unit. First, the hydraulic control valve adjusts the hydraulic pressure applied to the rotating body, and the actuator generates a driving force for driving the valve body of the hydraulic control valve. The control unit controls the adjustment of the hydraulic pressure by the hydraulic control valve by manipulating the current applied to the coil of the actuator.
The predetermined rotating body is, for example, “shoe housing 12 (a part of“ housing 18 ”)” or “vane rotor 14” disclosed in Patent Document 1.

  By the way, when the temperature of the hydraulic oil (oil temperature) is low, the valve advance and delay operations are delayed due to the viscosity of the hydraulic oil, and the opening / closing timing becomes inappropriate, causing combustion of the internal combustion engine to be unsuccessful. It may become stable. Therefore, the oil temperature is estimated based on the temperature (water temperature) of the cooling water of the internal combustion engine and the temperature of the intake air (intake air temperature), and the operation of the variable valve device is stopped when the estimated oil temperature is below a predetermined threshold value. A control method is known (for example, refer to Patent Document 2).

However, demands for improving fuel consumption, reducing exhaust emissions, and improving output are increasing, and there is a high demand for operating the variable valve device even when the oil temperature is low.
Therefore, in the variable valve device, various types of hydraulic circuits from the hydraulic control valve to the rotating body can be appropriately advanced or retarded even at low temperatures in accordance with the viscosity of the hydraulic oil. Improvement measures are being considered.
Therefore, it is necessary that the actuator be operated at a low temperature so that the hydraulic pressure can be adjusted.

Here, the possibility of hindering the operation of the actuator at a low temperature will be considered.
First, in a “dry” variable valve device in which hydraulic oil does not flow into the actuator, there is a possibility that moisture present in the actuator freezes and hinders movement of the mover. Further, in a “wet” variable valve device in which hydraulic oil flows into the actuator, there is a possibility that the hydraulic oil flowing into the actuator becomes highly viscous and hinders movement of the mover.
Therefore, in order to ensure the operation at a low temperature in the actuator, it is necessary to eliminate icing or increase in the viscosity of the hydraulic oil in the actuator.

  Patent Document 3 discloses a technique for operating a spool before starting an internal combustion engine for the purpose of cutting or discharging foreign matter that has entered the hydraulic control valve. However, the technique of Patent Document 3 is intended to cut or discharge foreign matter by operating a spool. When icing or high viscosity of hydraulic fluid occurs in the actuator, The spool cannot be operated.

JP 2009-024601 A Japanese Patent No. 38766648 JP 2009-074402

  The present invention has been made to solve the above problems, and an object of the present invention is to ensure the operation of the electromagnetic actuator at a low temperature in the variable valve timing device.

  The variable valve timing device (variable valve device) of the first invention of the present application is mounted on a vehicle and rotates a predetermined rotating body by hydraulic pressure to advance or retard the valve opening / closing timing. Hydraulic control valve, electromagnetic actuator and control means. First, the hydraulic control valve adjusts the hydraulic pressure applied to the rotating body, and the actuator generates a driving force for driving the valve body of the hydraulic control valve.

The control means controls the adjustment of the hydraulic pressure by the hydraulic control valve by manipulating the current applied to the coil of the actuator. The control means has a warm-up mode in which a current is applied to the coil to heat it before the internal combustion engine is started.
As a result, before the internal combustion engine is started, it is possible to eliminate freezing in the actuator or increase in the viscosity of the hydraulic oil due to the heat generated by the coil. For this reason, the operation | movement at the time of the low temperature of an actuator is securable.

  According to the second invention of the present application, the variable valve device includes the following rotation speed detection means and temperature detection means. First, the rotational speed detection means detects a signal corresponding to the rotational speed of the internal combustion engine, and outputs a signal indicating the rotational speed to the control means. The temperature detecting means detects the outside air temperature or the temperature corresponding to the outside air temperature at any part of the vehicle and changes according to the outside air temperature, and sends a signal indicating the outside air temperature or the outside air equivalent temperature to the control means. Output.

  The control means confirms that the rotational speed of the internal combustion engine is zero based on the signal output from the rotational speed detection means, and further, the outside air temperature is below a predetermined threshold based on the signal output from the temperature detection means. When it is confirmed, the warm-up mode is started. Further, the control means ends the warm-up mode before the rotational speed of the internal combustion engine increases from zero.

Thereby, when execution of the warm-up mode is useless or impossible, it is possible to prevent wasteful power consumption by canceling the execution of the warm-up mode. That is, when the outside air temperature is high, it is unnecessary to execute the warm-up mode. In addition, when the internal combustion engine speed is not zero (that is, when the internal combustion engine is already in operation), normal advance / retard control is prioritized, so the warm-up mode is not executed. Is possible.
As described above, by setting the rotation speed of the internal combustion engine to zero and the outside air temperature threshold value or less as conditions for executing the warm-up mode, it is possible to prevent wasteful power consumption due to execution of the warm-up mode.

According to the third invention of the present application, the variable valve device includes the following start prediction means. That is, the start predicting means outputs a signal for causing the control means to predict the start of the internal combustion engine. The control means executes the warm-up mode when the start of the internal combustion engine is predicted based on the signal output from the start prediction means.
It is not necessary to execute the warm-up mode even when the internal combustion engine is not predicted to start. Therefore, by setting the foreseeing of the internal combustion engine as a condition for executing the warm-up mode, it is possible to prevent wasteful power consumption due to the execution of the warm-up mode.

According to the fourth invention of the present application, the control means obtains a command value of a current to be given to the coil during execution of the warm-up mode in accordance with a signal output from the temperature detection means.
As a result, the command value of the current can be obtained according to the magnitude of the resistance of the electric circuit including the coil, so that it is possible to quickly warm up by applying a high current to the coil. It is also possible to prevent excessive power consumption due to execution of.

According to the fifth invention of the present application, the control means gradually increases the command value of the current applied to the coil from zero when the warm-up mode is executed.
Thereby, rapid acceleration of the spool accompanying the start of the warm-up mode can be prevented. For this reason, it is possible to mitigate a collision sound generated when the spool collides with a stopper or the like.

According to the sixth invention of the present application, the variable valve device includes a time counting unit that counts the stop time of the internal combustion engine, and the control unit is configured to perform a warm-up mode when the count value by the time measuring unit exceeds a predetermined threshold value. Execute.
As a result, the warm-up mode can be executed by selecting a state in which icing or increase in the viscosity of the hydraulic oil has sufficiently progressed. For this reason, the effect of executing the warm-up mode can be enhanced.

  According to the seventh invention of the present application, at least two temperature detection means are provided, and the control means determines whether or not to execute the warm-up mode based on signals output from the two temperature detection means. . According to the eighth invention of the present application, the control means obtains a difference between the temperatures detected by the two temperature detection means based on the signals output from the two temperature detection means, and the difference between the temperatures is a predetermined value. When it is smaller than the threshold value, the warm-up mode is executed.

  Thus, by monitoring two temperatures, it is possible to estimate the degree of freezing and the increase in viscosity of the hydraulic oil. For example, the difference between two temperatures is monitored, and when the temperature difference becomes smaller than a predetermined threshold, it is estimated that freezing or increase in viscosity of hydraulic oil is a level that requires execution of the warm-up mode. can do. For this reason, it is possible to execute the warm-up mode by selecting a state in which freezing and increase in the viscosity of the hydraulic oil have sufficiently progressed without counting the stop time of the internal combustion engine.

According to the ninth invention of the present application, the variable valve device includes battery detection means for detecting the voltage of the in-vehicle battery and outputting a signal indicating the voltage of the in-vehicle battery to the control means. Then, the control means determines whether or not to execute the warm-up mode based on the signal output from the battery detection means.
Accordingly, it is possible to give priority to the start of the internal combustion engine by the starter without executing the warm-up mode when the charge amount of the in-vehicle battery is low.

According to the tenth aspect of the present invention, the hydraulic control valve is a spool valve, and the spool as the valve element is driven in its axial direction to adjust the hydraulic pressure. The rotating shaft of the rotating body and the shaft of the spool are coaxial.
Thereby, regarding the hydraulic circuit from the hydraulic control valve to the rotating body, the pressure loss of the oil passage can be reduced. In the variable valve device in which the pressure loss of the oil passage is reduced, the operation range of the variable valve device can be expanded to the low temperature side by further executing the warm-up mode with the actuator. For this reason, further fuel consumption improvement, exhaust emission reduction, output improvement, etc. can be achieved.

It is a block diagram which shows the structure of an adjustment mechanism, a hydraulic control valve, and an actuator among variable valve apparatuses (Example 1). 1 is an overall configuration diagram of a variable valve device (Example 1). FIG. 6 is a flowchart illustrating a control procedure of the variable valve device (Example 1). It is a time chart which shows operation | movement of a variable valve apparatus (Example 1). It is a time chart which shows the aspect of an applied electric current (Example 1). It is a time chart which shows the aspect of an applied electric current (Example 3). (Example 4) which is a time chart which shows the aspect of an applied current. (Example 5) which is a whole block diagram of a variable valve apparatus. It is a flowchart which shows the control procedure of a variable valve apparatus (Example 5). (Example 5) which is a time chart which shows operation | movement of a variable valve apparatus. (Example 6) which is a whole block diagram of a variable valve apparatus. It is a flowchart which shows the control procedure of a variable valve apparatus (Example 6). (Example 6) which is a time chart which shows operation | movement of a variable valve apparatus. (Example 7) which is a whole block diagram of a variable valve apparatus. (Example 7) which is a flowchart which shows the control procedure of a variable valve apparatus. (Example 7) which is a time chart which shows operation | movement of a variable valve apparatus. It is a block diagram which shows the structure of an adjustment mechanism, a hydraulic control valve, and an actuator among variable valve apparatuses (modification example). It is a block diagram which shows the structure of an adjustment mechanism, a hydraulic control valve, and an actuator among variable valve apparatuses (modification example). It is a whole block diagram of a variable valve apparatus (modification). It is a flowchart which shows the control procedure of a variable valve apparatus (modification). It is a time chart which shows operation | movement of a variable valve apparatus (modification).

  The variable valve device of the embodiment will be described based on the following examples. In addition, an Example discloses a specific example, and it cannot be overemphasized that this invention is not limited to an Example.

[Configuration of Example 1]
The configuration of the variable valve device 1 according to the first embodiment will be described with reference to the drawings.
The variable valve device 1 advances or retards the opening / closing timing of a valve of an internal combustion engine for the purpose of improving fuel consumption, reducing exhaust emission, and improving output. 3. An electromagnetic actuator 4, a control means 5, a start prediction means 6, a rotation speed detection means 7, a temperature detection means 8 and the like are provided.

  The adjusting mechanism 2 advances or retards the valve opening / closing timing by advancing or retarding the rotation of the camshaft 10 relative to the rotation of the crankshaft. And a rotating body (housing 11, vane rotor 12, etc.) that is provided coaxially and rotates by hydraulic pressure.

  The hydraulic control valve 3 adjusts the hydraulic pressure applied to the housing 11 and the vane rotor 12. The hydraulic control valve 3 is a spool valve, and the spool 13 serving as a valve element is driven in its own axial direction by the driving force generated by the actuator 4 to adjust the hydraulic pressure. Further, the rotation axis of the housing 11 and the vane rotor 12 and the axis of the spool 13 are coaxial.

  The actuator 4 generates a driving force for driving the spool 13, and includes a coil 15 that generates a magnetic flux when energized, a fixed core 16 and a movable core 17 that pass the magnetic flux on the inner peripheral side of the coil 15, and an output shaft of the driving force. As a rod 18 or the like. The actuator 4 is arranged coaxially with the adjusting mechanism 2 and the hydraulic control valve 3, and the rod 18 directly contacts one end of the spool 13 to transmit the driving force to the spool 13.

  The adjustment mechanism 2, the hydraulic control valve 3 and the actuator 4 of Examples 1 to 7 of the present application are respectively in the first embodiment of Japanese Patent Application No. 2013-080442 (hereinafter referred to as “first prior application”). It has the same configuration as the “valve timing adjusting device 2”, “hydraulic control valve 3” and “electromagnetic actuator 1” described.

Further, the camshaft 10, the housing 11, the vane rotor 12, the spool 13, the coil 15, the fixed core 16, the movable core 17, and the rod 18 of the first embodiment are the same as the “camshaft 5 in the first embodiment of the first prior application. ”,“ Housing 70 ”,“ vane rotor 79 ”,“ spool 90 ”,“ coil 10 ”,“ fixed core 20 ”,“ movable core 30 ”, and“ rod 40 ”.
Therefore, the details of the adjusting mechanism 2, the hydraulic control valve 3 and the actuator 4 and the surrounding structure are as described in the first embodiment of the first prior application, and detailed description thereof is omitted.

  Furthermore, according to the description of the first embodiment of the first prior application, the inflow of the working oil into the actuator 4 is suppressed, but the inflow of the working oil is not completely blocked. Therefore, the variable valve device 1 of the first embodiment is wet, and there is a possibility that the movement of the movable core 17 and the like may be hindered by the increase in viscosity of the hydraulic oil at low temperatures.

  The control means 5 is, for example, an electronic control unit (ECU: hereinafter, the control means 5 is referred to as ECU 5) that controls the operation of the internal combustion engine. The ECU 5 also has a CPU having a control function and an arithmetic function, a storage device such as a ROM and a RAM, an input device that receives input of signals output from various sensors, and a signal for controlling energization of various devices. It is a known structure having an output device for outputting.

The ECU 5 controls the adjustment of the hydraulic pressure by the hydraulic control valve 3 by operating the current applied to the coil 15 based on signals output from various sensors and the like.
Further, the ECU 5 has a warm-up mode in which a current is applied to the coil 15 to heat it before the internal combustion engine is started in order to ensure operation at a low temperature.
The various sensors that output signals to the ECU 5 include a start prediction means 6, a rotation speed detection means 7, a temperature detection means 8, and the like described below.

  The start prediction means 6 outputs a signal for allowing the ECU 5 to predict the start of the internal combustion engine. For example, a keyless entry door lock release switch, a door switch, or the like can be adopted as the start prediction means 6.

  The rotational speed detection means 7 detects a signal corresponding to the rotational speed of the internal combustion engine and outputs a signal indicating the rotational speed to the ECU 5. For example, a crank angle sensor or a cam angle sensor is used as the rotational speed detection means 7. Can be adopted.

  The temperature detecting means 8 detects the outside air temperature or the temperature corresponding to the outside air temperature at any part of the vehicle and changes according to the outside air temperature, and outputs a signal indicating the outside air temperature or the outside air equivalent temperature to the ECU 5. . That is, the temperature detection means 8 is an outside air temperature sensor that detects an outside air temperature (hereinafter referred to as an outside air temperature) and outputs a signal indicating the outside air temperature, for example. Further, as the outside air equivalent temperature, for example, the temperature of the cooling water of the internal combustion engine (hereinafter referred to as water temperature), the temperature of the hydraulic oil (hereinafter referred to as oil temperature), or the intake air sucked into the internal combustion engine Temperature (hereinafter referred to as intake air temperature). Therefore, when detecting the temperature corresponding to the outside air, the temperature detecting means 8 may employ a water temperature sensor, an oil temperature sensor, an intake air temperature sensor, or the like.

Hereinafter, execution of the warm-up mode by the ECU 5 will be described.
The ECU 5 predicts the start of the internal combustion engine based on the signal output from the start prediction means 6, confirms that the rotational speed of the internal combustion engine is zero based on the signal output from the rotation speed detection means 7, When it is confirmed that the outside air temperature is equal to or lower than a predetermined threshold based on the signal output from the temperature detecting means 8, the warm-up mode is started. Further, the ECU 5 ends the warm-up mode before the rotational speed of the internal combustion engine increases from zero.

  Next, a flow for executing the warm-up mode will be described based on the flowchart of FIG. 3 and the time chart of FIG. In the following description, the start predicting means 6 is a door switch.

  According to the flowchart of FIG. 3, first, in step S1, it is determined whether or not the start of the internal combustion engine is foreseen. This determination is made based on a signal output from the start prediction means 6. That is, when the ECU 5 receives the door switch ON input, it is assumed that the internal combustion engine has been started (YES), and the process proceeds to step S2, and when the door switch ON input is not received (the door switch is turned OFF). If it is maintained), it is regarded that the internal combustion engine is not predicted to start (NO), and the flow is terminated.

  Next, in step S2, it is determined whether or not the internal combustion engine is stopped. This determination is made based on a signal output from the rotation speed detection means 7. That is, based on the signal input from the rotational speed detection means 7 to the ECU 5, when the rotational speed of the internal combustion engine is considered to be zero, the internal combustion engine is regarded as stopped (YES), and the process proceeds to step S3. . If it is determined that the number of revolutions of the internal combustion engine is not zero, it is determined that the internal combustion engine has not stopped (NO), and the flow ends.

  Further, in step S3, it is determined whether or not the outside air temperature is equal to or lower than a predetermined threshold value. This determination is made based on a signal output from the temperature detecting means 8. That is, based on the signal input from the temperature detection means 8 to the ECU 5, when the outside air temperature is considered to be equal to or lower than the predetermined threshold (YES), the process proceeds to step S4 and the warm-up mode is executed. If the outside air temperature is considered to be greater than the predetermined threshold (NO), the flow ends.

  According to the time chart of FIG. 4, the door switch is turned on by the passenger's door opening operation at time t <b> 0. At this time, since the rotational speed of the internal combustion engine is zero and the outside air temperature is also below a predetermined threshold value, the warm-up mode is immediately executed.

Thereafter, the warm-up mode ends at time t1, and further, the internal combustion engine is started by the starter 20 at time t2, and the rotational speed increases from zero.
Various modes can be considered for the end of the warm-up mode. For example, the execution time of the warm-up mode may be specified in advance, and the warm-up mode may be terminated when the specified time is reached. Further, the warm-up mode may be terminated when the ignition switch is turned on.

  In the first embodiment, the current (hereinafter sometimes referred to as applied current) applied to the coil 15 in the warm-up mode is a numerical value used for normal advance or retard control during operation of the internal combustion engine. Is also controlled to a large constant value (see FIG. 5). Further, for example, a current sensor may be provided to detect the applied current and fed back to the ECU 5, and the ECU 5 may perform control so that the detected value by the current sensor and the command value are substantially matched.

[Effects of Example 1]
The variable valve device 1 of the first embodiment is wet, and the ECU 5 has a warm-up mode in which a current is supplied to the coil 15 to heat it before the internal combustion engine is started.
Thereby, before the internal combustion engine is started, the increase in viscosity of the hydraulic oil in the actuator 4 due to the heat generated by the coil 15 can be eliminated. For this reason, since the movement of the movable core 17 and the like in the actuator 4 is not hindered by the hydraulic oil, the operation of the actuator 4 at a low temperature can be ensured.

  Further, the ECU 5 predicts the start of the internal combustion engine based on the signal output from the start prediction means 6 and confirms that the rotation speed of the internal combustion engine is zero based on the signal output from the rotation speed detection means 7. Further, when it is confirmed that the outside air temperature is equal to or lower than a predetermined threshold based on the signal output from the temperature detection means 8, the warm-up mode is started. Further, the ECU 5 ends the warm-up mode before the rotational speed of the internal combustion engine increases from zero.

Thereby, when execution of the warm-up mode is useless or impossible, it is possible to prevent wasteful power consumption by canceling the execution of the warm-up mode. That is, it is unnecessary to execute the warm-up mode when the start of the internal combustion engine is not predicted or when the outside air temperature is high. In addition, when the internal combustion engine speed is not zero (that is, when the internal combustion engine is already in operation), normal advance / retard control is prioritized, so the warm-up mode is not executed. Is possible.
As described above, it is possible to prevent wasteful power consumption due to execution of the warm-up mode by setting the start-up prediction of the internal combustion engine, the outside air temperature threshold value or less, and the engine speed of zero as the condition for executing the warm-up mode. it can.

Furthermore, the hydraulic control valve 3 is a spool valve, and the spool 13 as a valve element is driven in its axial direction to adjust the hydraulic pressure. The rotating shaft of the rotating body (housing 11 and vane rotor 12) and the shaft of the spool 13 are coaxial.
Thereby, regarding the hydraulic circuit from the hydraulic control valve 3 to the rotating body, the pressure loss of the oil passage can be reduced. Further, in the variable valve device 1 in which the pressure loss of the oil passage is reduced, the operation range of the variable valve device 1 can be expanded to the low temperature side by further executing the warm-up mode with the actuator 4. For this reason, further fuel consumption improvement, exhaust emission reduction, output improvement, etc. can be achieved.

[Example 2]
According to the variable valve device 1 of the second embodiment, the ECU 5 obtains a command value for the applied current in accordance with a signal output from the temperature detection means 8.
Thereby, since it is possible to obtain the command value of the applied current according to the magnitude of the resistance of the electric circuit including the coil 15, it is possible to rapidly warm up by applying a high current to the coil 15, Excessive power consumption due to execution of the warm-up mode can also be prevented.

Example 3
According to the variable valve device 1 of the third embodiment, the ECU 5 gradually increases the command value of the applied current from zero (see FIG. 6).
Thereby, the rapid acceleration of the spool 13 accompanying the start of the warm-up mode can be prevented. For this reason, it is possible to mitigate a collision sound generated when the spool 13 collides with a stopper or the like. Note that the stopper and the like of this embodiment are provided on the sleeve 22.

Example 4
According to the variable valve device 1 of the fourth embodiment, the ECU 5 applies the applied current to the coil 15 in a plurality of times so as to form a plurality of rectangular waves (see FIG. 7).

Example 5
The variable valve device 1 according to the fifth embodiment includes a timer 24 that counts the stop time of the internal combustion engine, and the ECU 5 executes the warm-up mode when the count value by the timer 24 exceeds a predetermined threshold. . Further, for example, a timing device provided in the ECU 5 can be used as the timing unit 24 (see FIG. 8).

  Hereinafter, the flow for executing the warm-up mode in the fifth embodiment will be described based on the flowchart of FIG. 9 and the time chart of FIG. Of the steps in the flowchart of FIG. 9, steps S11, S13, and S14 are the same as steps S1, S3, and S4 of the first embodiment, and a description thereof is omitted.

  In step S12, it is determined whether or not the internal combustion engine has been stopped for a predetermined time or more. This determination is made based on the signal output from the rotation speed detecting means 7 and the count value by the time measuring means 24. That is, when the rotational speed of the internal combustion engine is considered to be zero based on a signal input from the rotational speed detection means 7 to the ECU 5, and the count value by the time measuring means 24 exceeds a predetermined threshold value, the internal combustion engine Is stopped for a predetermined time or more (YES), the process proceeds to step S13. Further, when it is considered that the rotational speed of the internal combustion engine is not zero, or when the count value does not exceed a predetermined threshold value, it is assumed that the internal combustion engine has not stopped for a predetermined time (NO), and the flow is finish.

Then, according to the time chart of FIG. 10, the door switch is turned on by the passenger opening the door at time t0. At this time, since the internal combustion engine is stopped for a predetermined time or more and the outside air temperature is also a predetermined threshold value or less, the warm-up mode is immediately executed.
Thereafter, the warm-up mode ends at time t1, and further, the internal combustion engine is started by the starter 20 at time t2, and the rotational speed increases from zero.

  As described above, according to the variable valve device 1 of the fifth embodiment, the warm-up mode can be executed by selecting a state in which the stop time of the internal combustion engine is long and the viscosity of the hydraulic oil has sufficiently increased. For this reason, the effect of executing the warm-up mode can be enhanced.

Example 6
According to the variable valve device 1 of the sixth embodiment, at least two temperature detecting means 8 are provided (see FIG. 11: hereinafter, in the sixth embodiment, the two temperature detecting means 8 are defined as temperature detecting means 8A and 8B. explain.). Then, the ECU 5 determines whether or not to execute the warm-up mode based on signals output from the temperature detection means 8A and 8B.

  That is, the ECU 5 obtains a temperature difference detected by the temperature detection means 8A, 8B based on the signals output from the temperature detection means 8A, 8B, and when the temperature difference is smaller than a predetermined threshold value, the ECU 5 Execute machine mode. That is, the temperature difference is monitored, and when the temperature difference becomes smaller than a predetermined threshold, it is estimated that the increase in viscosity of the hydraulic oil is at a level that requires execution of the warm-up mode. Run the mode.

  Examples of combinations of the temperature detection means 8A and 8B include a combination of an outside air temperature sensor and a water temperature sensor, a combination of an outside air temperature sensor and an oil temperature sensor, or a combination of a water temperature sensor and an oil temperature sensor. (Hereinafter, in the sixth embodiment, the temperature detection means 8A and 8B will be described as an outside air temperature sensor and a water temperature sensor, respectively).

  Hereinafter, the flow for executing the warm-up mode in the sixth embodiment will be described based on the flowchart of FIG. 12 and the time chart of FIG. Of the steps in the flowchart of FIG. 12, steps S21, S22, and S25 are the same as steps S1, S2, and S4 of the first embodiment, and a description thereof is omitted.

  First, in step S23, it is determined whether or not the outside air temperature is equal to or lower than a predetermined threshold value. This determination is made based on a signal output from the temperature detection means 8A (outside air temperature sensor). That is, if it is determined that the outside air temperature is equal to or lower than the predetermined threshold based on the signal input from the temperature detection means 8A to the ECU 5 (YES), the process proceeds to step S24, and the outside air temperature is considered to be greater than the predetermined threshold. If it has been made (NO), the flow is terminated.

  Next, in step S24, it is determined whether or not the temperature difference detected by the temperature detectors 8A and 8B is equal to or smaller than a predetermined threshold value. This determination is made based on signals output from the temperature detection means 8A (outside air temperature sensor) and the temperature detection means 8B (water temperature sensor). That is, a temperature difference between the water temperature and the outside air temperature is obtained based on a signal input from the temperature detection means 8A, 8B to the ECU 5, and if this temperature difference is considered to be equal to or less than a predetermined threshold value (YES), the process goes to step S25. If it is determined that the temperature difference is greater than the predetermined threshold (NO), the flow ends.

Then, according to the time chart of FIG. 13, the door switch is turned on by the occupant's door opening operation at time t0. At this time, the rotational speed of the internal combustion engine is zero, the outside air temperature is also less than or equal to a predetermined threshold, and the temperature difference between the water temperature and the outside air temperature is also less than or equal to the predetermined threshold, so the warm-up mode is immediately executed. .
Thereafter, the warm-up mode ends at time t1, and further, the internal combustion engine is started by the starter 20 at time t2, and the rotational speed increases from zero.

  As described above, for example, the temperature difference between the outside air temperature and the water temperature is monitored, and when the temperature difference becomes smaller than a predetermined threshold, the increase in viscosity of the hydraulic oil is at a level that requires execution of the warm-up mode. It can be estimated that there is. For this reason, the warm-up mode can be executed by selecting a state in which the increase in the viscosity of the hydraulic oil has sufficiently progressed without counting the stop time of the internal combustion engine.

Example 7
The variable valve device 1 according to the seventh embodiment includes a battery detection unit 26 that detects the voltage of the in-vehicle battery and outputs a signal indicating the voltage of the in-vehicle battery to the ECU 5 (see FIG. 14). Then, the ECU 5 determines whether or not to execute the warm-up mode based on the signal output from the battery detection unit 26. A known voltage sensor can be used for the battery detection means 26.

  Hereinafter, the flow for executing the warm-up mode in the seventh embodiment will be described based on the flowchart of FIG. 15 and the time chart of FIG. Of the steps in the flowchart of FIG. 15, steps S31, S32, S33, and S35 are the same as steps S1, S2, S3, and S4 of the first embodiment, and a description thereof is omitted.

  In step S34, it is determined whether or not the voltage of the in-vehicle battery is equal to or higher than a predetermined threshold value. This determination is made based on a signal output from the battery detection means 26. That is, based on the signal input from the battery detection means 26 to the ECU 5, when it is determined that the voltage of the in-vehicle battery is equal to or higher than the predetermined threshold (YES), the process proceeds to step S35, where the voltage of the in-vehicle battery is greater than the predetermined threshold. Is also considered small (NO), the flow is terminated.

  Then, according to the time chart of FIG. 16, the door switch is turned on by the passenger's operation of opening the door at time t0. At this time, the rotational speed of the internal combustion engine is zero, the outside air temperature is also below a predetermined threshold value, and the on-vehicle battery voltage is above the predetermined threshold value, so the warm-up mode is immediately executed.

Thereafter, the warm-up mode ends at time t1, and further, the internal combustion engine is started by the starter 20 at time t2, and the rotational speed increases from zero.
As described above, it is possible to give priority to the start of the internal combustion engine by the starter 20 without executing the warm-up mode when the charge amount of the in-vehicle battery is low.

[Modification]
The aspect of the variable valve device 1 is not limited to the embodiment, and various modifications can be considered.
For example, the variable valve device 1 of the embodiment is a wet type that does not completely block the inflow of hydraulic oil into the actuator 4, but blocks the inflow of hydraulic oil into the actuator 4 as shown in FIG. 17. In the dry variable valve device 1, execution of the warm-up mode similar to those in the first to seventh embodiments and determination as to whether or not the warm-up mode can be performed may be performed.

  When the variable valve device 1 is a dry type, the movement of the movable core 17 and the like may be hindered due to freezing of moisture at a low temperature. For this reason, icing in the actuator 4 can be eliminated by performing the warm-up mode similar to those in the first to seventh embodiments and determining whether or not the warm-up mode can be performed. For this reason, since the movement of the movable core 17 and the like in the actuator 4 is not hindered by freezing, the operation of the actuator 4 at a low temperature can be ensured in the dry variable valve device 1.

  Note that the adjustment mechanism 2 and the hydraulic control valve 3 shown in the modification of FIG. 17 are each “phase” described in the first embodiment of Japanese Patent Application No. 2014-053154 (hereinafter referred to as “second prior application”). This is the same configuration as the “adjustment mechanism 20” and the “oil passage switching valve 40”. In addition, the camshaft 10, the housing 11, the vane rotor 12 and the spool 13 in the modified example of FIG. 17 are the “camshaft 202”, “front cover 21”, and “vane rotor 32” in the first embodiment of the second prior application, respectively. And “spool 48”. Therefore, the details of the adjustment mechanism 2 and the hydraulic control valve 3 and the surrounding structure are as described in the first embodiment of the second prior application, and detailed description thereof is omitted.

  Further, the actuator 4 of the modified example of FIG. 17 has the same structure as that of the embodiment, and is arranged coaxially with the adjusting mechanism 2 and the hydraulic control valve 3, and the rod 18 is indirectly connected to one end of the spool 13 via a predetermined part. To contact the spool 13 and transmit the driving force to the spool 13.

  Further, as shown in FIG. 18, in the variable valve device 1 in which the actuator 4 is not arranged coaxially with the adjustment mechanism 2, execution of the warm-up mode similar to those in the first to seventh embodiments and whether or not the warm-up mode can be executed. You may make it judge.

  Note that the adjustment mechanism 2 shown in the modification of FIG. 18 has the same configuration as the “driving unit 10” described in the first embodiment of Patent Document 1 (hereinafter sometimes referred to as “third prior application”). It is. Further, the camshaft 10, the housing 11 and the vane rotor 12 of the modification of FIG. 18 have the same configurations as the “camshaft 2”, “shoe housing 12” and “vane rotor 14” in the first embodiment of the third prior application, respectively. It is. Therefore, the details of the adjustment mechanism 2 and the surrounding structure are as described in the first embodiment of the third prior application, and detailed description thereof is omitted.

  Note that the hydraulic control valve 3 and the actuator 4 of the modified example of FIG. 18 are integrated with the yoke of the actuator 4 being caulked and fixed to the sleeve 22 of the hydraulic control valve 3. In the first embodiment, the configuration is the same as that of the “switching control valve 31”.

  Also, the mode of determining whether or not the warm-up mode can be executed is not limited to the embodiment, and various modes can be adopted. For example, whether or not the warm-up mode can be executed may be determined using signals output from all of the start predicting means 6, the rotation speed detecting means 7, the temperature detecting means 8, the time measuring means 24, and the battery detecting means 26.

  Further, whether or not the warm-up mode can be executed may be determined using signals output from the rotation speed detection means 7 and the temperature detection means 8. The rotation speed detection means 7, the temperature detection means 8, and the time measurement means 24 may be determined. Whether or not the warm-up mode can be executed may be determined using the signals output from the three, and the signals output from the three of the rotation speed detection means 7, the temperature detection means 8, and the battery detection means 26 are used. Whether or not the warm-up mode can be executed may be determined.

For example, when it is determined whether or not the warm-up mode can be executed using signals output from the rotation speed detection means 7 and the temperature detection means 8 (see FIG. 19), the warm-up mode is determined according to the flowchart shown in FIG. Can be executed.
Note that steps S41, S42, and S43 in the flowchart of FIG. 20 are the same as steps S2, S3, and S4 of the first embodiment, and a description thereof is omitted.

According to the time chart of FIG. 21, the warm-up mode is immediately executed at time t0 because the rotational speed of the internal combustion engine is zero and the outside air temperature is equal to or lower than the predetermined threshold value.
Thereafter, the warm-up mode ends at time t1, and further, the internal combustion engine is started by the starter 20 at time t2, and the rotational speed increases from zero.

DESCRIPTION OF SYMBOLS 1 Variable valve timing apparatus (variable valve apparatus) 3 Hydraulic control valve 4 Actuator 5 ECU (control means) 11 Housing (rotating body) 12 Vane rotor (rotating body) 15 Coil

Claims (10)

A variable valve timing device that is mounted on a vehicle and advances or retards the opening / closing timing of at least one of an intake valve and an exhaust valve of an internal combustion engine by rotating predetermined rotating bodies (11, 12) by hydraulic pressure. In (1),
A hydraulic control valve (3) for adjusting the hydraulic pressure applied to the rotating bodies (11, 12), an electromagnetic actuator (4) for generating a driving force for driving the valve body of the hydraulic control valve (3), Control means (5) for controlling adjustment of hydraulic pressure by the hydraulic control valve (3) by operating a current applied to the coil (15) of the actuator (4),
The variable valve timing device (1) characterized in that the control means (5) has a warm-up mode in which a current is supplied to the coil (15) to heat it before the internal combustion engine is started. The variable valve timing device (1) according to claim 1,
A rotational speed detection means (7) for detecting a signal corresponding to the rotational speed of the internal combustion engine and outputting a signal indicating the rotational speed to the control means (5);
An outside air temperature or a temperature in any part of the vehicle, which is an outside air equivalent temperature that changes according to the outside air temperature, is detected, and a signal indicating the outside air temperature or the outside air equivalent temperature is output to the control means (5). Temperature detecting means (8) for performing,
The control means (5)
Based on the signal output from the rotational speed detection means (7), it is confirmed that the rotational speed of the internal combustion engine is zero. Further, based on the signal output from the temperature detection means (8), the outside air temperature is When confirming that it is below a predetermined threshold, start the warm-up mode,
The variable valve timing device (1), wherein the warm-up mode is terminated before the rotational speed of the internal combustion engine increases from zero. In the variable valve timing device (1) according to claim 1 or 2,
A start predicting means (6) for outputting a signal for allowing the control means (5) to predict the start of the internal combustion engine;
The control means (5) executes the warm-up mode when the start of the internal combustion engine is predicted based on a signal output from the start prediction means (6). 1). In the variable valve timing device (1) according to any one of claims 1 to 3,
An outside air temperature or a temperature in any part of the vehicle, which is an outside air equivalent temperature that changes according to the outside air temperature, is detected, and a signal indicating the outside air temperature or the outside air equivalent temperature is output to the control means (5). Temperature detecting means (8) for
The control means (5) obtains a command value of a current to be given to the coil (15) during execution of the warm-up mode according to a signal output from the temperature detection means (8). Valve timing device (1). In the variable valve timing device (1) according to any one of claims 1 to 4,
The variable valve timing device (1), wherein the control means (5) gradually increases a command value of a current applied to the coil (15) from zero when the warm-up mode is executed. A variable valve timing device (1) according to any one of claims 1 to 5,
Comprising time measuring means (24) for counting the stop time of the internal combustion engine,
The variable valve timing device (1), wherein the control means (5) executes the warm-up mode when a count value by the time measuring means (24) exceeds a predetermined threshold value. Variable valve timing device (1) according to any one of claims 1 to 6,
An outside air temperature or a temperature in any part of the vehicle, which is an outside air equivalent temperature that changes according to the outside air temperature, is detected, and a signal indicating the outside air temperature or the outside air equivalent temperature is output to the control means (5). Temperature detecting means (8) for
At least two temperature detection means (8) are provided,
The control means (5) determines whether or not to execute the warm-up mode based on signals output from the two temperature detection means (8A, 8B). ). The variable valve timing device (1) according to claim 7,
The control means (5) obtains the difference between the temperatures detected by the two temperature detection means (8A, 8B) based on the signals output from the two temperature detection means (8A, 8B), and this temperature The variable valve timing device (1) is characterized in that the warm-up mode is executed when the difference between them is smaller than a predetermined threshold value. Variable valve timing device (1) according to any one of claims 1 to 8,
Battery detection means (26) for detecting the voltage of the in-vehicle battery and outputting a signal indicating the voltage of the in-vehicle battery to the control means (5);
The variable valve timing device (1), wherein the control means (5) determines whether or not to execute the warm-up mode based on a signal output from the battery detection means (26). Variable valve timing device (1) according to any one of claims 1 to 9,
The hydraulic control valve (3) is a spool valve, and the spool (13) as a valve element is driven in its axial direction to adjust the hydraulic pressure,
The variable valve timing device (1), wherein a rotating shaft of the rotating bodies (11, 12) and a shaft of the spool (13) are coaxial.

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