JP2009097450A - Valve system of internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology for detecting in advance whether or not the cam can be operated as required when the driving source starts in a valve system of an internal combustion engine where a cam rotated or rocked by a driving source independent of the internal combustion engine opens or closes a valve. <P>SOLUTION: In the valve system of the internal combustion engine where the cam rotated or rocked by the driving source independent of the internal combustion engine opens or closes the valve, before a normal start request is given to the driving source put in the stop state, the driving source is forcibly started to make at least a turn of the cam, and failure determination on whether or not the cam is normally rotated is performed. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a valve operating system including a cam that is rotated or oscillated by a drive source independent of an internal combustion engine.

As a valve operating system for an internal combustion engine, a valve operating system for rotating or swinging a cam by a drive source independent of the internal combustion engine is known. As a technique using such a valve operating system, a technique has been proposed in which an intake valve is continuously opened and an exhaust valve is continuously closed during cranking of an internal combustion engine (for example, see Patent Document 1). reference).
JP 2007-182869 A

  By the way, when the drive source starts to rotate the stopped cam (hereinafter referred to as “start-up”), a relatively large driving force is required. For this reason, the cam may not rotate as required when the drive source is activated.

  Therefore, after the exhaust valve is continuously closed in the above-described prior art, when the drive source is started to open and close the exhaust valve, the drive source can rotate the cam as required. The exhaust valve may not open and close normally.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a drive source for a valve operating system of an internal combustion engine in which a valve rotated or swung by a drive source independent of the internal combustion engine opens and closes the valve. It is to provide a technology capable of detecting in advance whether the cam can be operated as requested at the time of activation of.

  In order to solve the above-described problems, the present invention provides a valve operating system for an internal combustion engine in which a cam rotated or swung by a drive source independent of the internal combustion engine opens and closes a valve. Before the start request is generated, the drive source is forcibly started to check the operation of the cam.

  More specifically, the present invention relates to a valve operating system for an internal combustion engine in which a cam rotated or swung by a drive source independent of the internal combustion engine opens and closes the valve, before the start request for the stopped drive source is generated. Control means for forcibly starting the drive source, and failure determination means for determining whether or not the cam is normally rotating or swinging when the drive source is forcibly started by the control means.

  The “start-up request” in the present invention is a request to start up the drive source in order to cause the valve to perform an opening / closing operation essential for the operation of the internal combustion engine. Such an activation request is generated when the valve is returned from a stopped or stopped state during the operation of the internal combustion engine, or when the valve opening / closing operation is started when the internal combustion engine is started. Hereinafter, the activation request as described above may be referred to as a “regular activation request”.

  There is a possibility that fuel injection or fuel combustion has already been performed at the time when the normal activation request as described above occurs. For this reason, when a failure occurs after the activation request is generated, problems occur such as affecting parts other than the valve operating system or deteriorating emissions.

  In contrast, according to the present invention, the failure determination is performed by forcibly starting the drive source before the start request is generated. If it is determined in the failure determination that the cam is not rotating or swinging normally, it is possible to take measures such as stopping fuel injection or stopping the operation of the spark plug. Therefore, it is possible to prevent the above-described problem from occurring.

  Here, the “cam does not rotate or swing normally” includes not only a state where the cam does not move at all, but also a state where the rotational speed or swing speed of the cam is far from a specified speed.

  In the present invention, the control means may control the drive source so that the cam rotates at least once when the drive source is forcibly activated. In this case, the failure determination means determines whether or not the cam has normally rotated once. This means that it is determined whether or not the valve normally opens and closes. Also, the lubricating oil can be spread over the sliding surface of the cam by rotating the cam at least once. Therefore, it is effective when the drive source is stopped for a long time.

  In the present invention, the control means may control the drive source so that the cam swings in a range where the valve does not lift when the drive source is forcibly activated. In this case, since the valve does not lift, the failure determination can be performed without affecting the operation state of the internal combustion engine. The failure determination by such a method can also be performed at the time of decelerating fuel cut operation of the internal combustion engine or at the time of reduced cylinder operation in which some cylinders of the internal combustion engine are deactivated.

  In the present invention, the control means includes a first control that controls the drive source so that the cam rotates at least once when the drive source is forcibly activated, and a drive source that swings the cam within a range in which the valve does not lift. You may make it perform 2nd control which controls.

  In this case, the failure determination means can determine whether or not the cam can normally rotate when the first control is executed, and whether or not the cam can swing normally when the second control is executed. Can be determined. As a result, the accuracy of failure determination is increased.

  By the way, if the drive source is stopped after the failure determination means determines that the cam is normally rotating or swinging, the cam may not normally rotate or swing when a subsequent activation request is generated.

  Therefore, the control means may continue to operate the drive source until the activation request is generated. For example, the control means executes the first control before the start request is generated and when the valve is lifted and does not affect the operation of the internal combustion engine. If the failure determination means determines the normal rotation of the cam during execution of the first control, the control means may execute the second control until an activation request is generated.

  Since the valve does not lift when the second control is executed, the second control is executed without affecting the operating state of the internal combustion engine even after fuel injection or after fuel combustion. It is possible to continue. Therefore, the control means can continue to execute the second control until the activation request is generated. If the drive source continues to swing the cam until the start request is generated, the load applied to the drive source when the start request is generated is reduced. As a result, the drive source facilitates normal operation of the cam when an activation request is generated. Further, the failure determination means can improve the failure determination accuracy as much as possible by continuously performing the failure determination during the execution of the second control.

The control means executes the first control and the second control when the drive source stop period is equal to or longer than a predetermined period, and performs only the second control when the drive source stop period is less than the predetermined period. It may be.

  If the stop period of the drive source becomes longer, the oil film on the sliding portion of the cam or valve becomes thinner or the viscosity of the lubricating oil becomes higher. In such a case, the friction when the cam or valve operates increases.

  On the contrary, when the stop period of the drive source is short, the oil film of the sliding portion of the cam or valve maintains a sufficient thickness and the viscosity of the lubricating oil becomes low. In such a case, the friction when the cam or valve operates is reduced.

  According to these findings, it can be said that the shorter the stop period, the easier it is for the valve to lift (open / close) normally. Therefore, when the stop period of the drive source is short, if the cam can swing normally, it can be considered that the cam can rotate normally. As a result, when the drive source stop period is short, the first control can be omitted. If the first control is omitted, an increase in energy consumption due to forced activation of the drive source can be minimized.

  Here, as a method of determining whether or not the stop period of the drive source is equal to or longer than a certain period, (1) measuring the stop time of the drive source and determining whether or not the measurement time is equal to or longer than the predetermined period. And (2) a method in which when the temperature of the cooling water (or lubricating oil) of the internal combustion engine is lower than the reference water temperature, the stop period is considered to be a certain period or more.

  In the present invention, the timing at which the control means forcibly activates the drive source can be exemplified before the activation request is generated and before the operation of the fuel injection valve.

  When the drive source is forcibly started at such timing, the first control can be performed without affecting the operating state of the internal combustion engine. For this reason, it becomes possible to raise failure determination accuracy. In addition, if a failure is detected before the fuel injection valve is operated, the fuel injected from the fuel injection valve may remain unburned in the intake port or the cylinder, or may be discharged unburned from the internal combustion engine. Is prevented.

  In the present invention, the timing at which the control means forcibly activates the drive source can be exemplified before the activation request is generated and before the operation of the spark plug.

  If the fuel is ignited in a state where the cam or the valve does not operate normally, there is a possibility that the flame or burnt gas flows backward to the intake system. On the other hand, if the failure determination is performed before the operation of the spark plug, the above-described problem can be avoided.

  In the present invention, the timing at which the control means forcibly activates the drive source can be exemplified by the time obtained by subtracting the time required for failure determination from the time when the activation request is generated. This is effective when the generation timing of the activation request can be predicted.

  If the drive source is forcibly started at a time obtained by subtracting the time required for failure determination from the start request generation time, the period during which the drive source is forcibly started is only the time required for failure determination. As a result, since the forced activation period of the drive source does not become unnecessarily long, an increase in energy consumption due to the forced activation of the drive source can be minimized.

  In addition, since a start request is generated at the end of the failure determination, the drive source is continuously operated from the time when the start request is generated until the start request is generated. As a result, the drive source can easily operate the cam normally when an activation request is generated.

  In order to solve the above-mentioned problems, the present invention provides a valve operating system for an internal combustion engine in which a cam rotated or swung by a drive source independent of the internal combustion engine opens and closes the valve. The failure determination may be performed regardless of the inside. In this case, it is preferable that the operation of the drive source is forcibly continued from the end of the failure determination until the next activation request is generated.

  Specifically, in a valve operating system for an internal combustion engine in which a cam rotated or swung by a drive source independent of the internal combustion engine opens and closes a valve, failure determination means for determining whether or not the cam has operated normally; Control means for forcibly continuing the operation of the drive source from when the failure determination by the failure determination means is completed until the next start-up request is generated.

  According to this invention, even if a stop request for the drive source is generated after the drive source failure determination is made, the operation of the drive source is forcibly continued until the next start request is generated. become.

  The stop request here is a stop request for the purpose of stopping or stopping the valve in the deceleration fuel cut operation, the reduced cylinder operation, etc., and the stop request accompanying the operation stop (ignition switch OFF) of the internal combustion engine is included. Absent.

  If the drive source is stopped after the failure determination is performed as described above, the cam may not operate normally when the next activation request is generated. For this reason, the failure determination result and the actual cam operation may be different. In particular, if the drive source is stopped after it is determined by the failure determination that the cam has operated normally, there is a concern that the cam cannot be operated normally when the next activation request is generated.

  On the other hand, if the drive source continues to operate from the end of the failure determination until the next start request is generated, the drive source can easily operate the cam normally at the next start. Even if it is determined by the failure determination that the cam does not operate normally, the temperature of the lubricating oil can be increased or the viscosity can be decreased by continuing to operate the drive source until the next start-up request occurs. . Therefore, it can be expected that the cam returns to a state in which it can operate normally.

  Note that if the interval from the end of failure determination to the next start request generation is excessively long, the energy consumption may become enormous due to the forced operation of the drive source. Therefore, when the activation request is not generated next time within a certain time from the end of the failure determination, the forced operation of the drive source may be terminated when a certain time has elapsed from the end of the failure determination. In this case, an excessive increase in energy consumption can be prevented.

  If the valve is in the fully closed state when the next activation request is generated, the control means controls the drive source to swing the cam within a range in which the valve does not lift before opening the valve according to the activation request, At that time, the failure determination means may determine whether or not the cam operates normally.

  According to such a configuration, the failure determination is performed again when the activation request is generated after the failure determination is completed, so that the failure determination accuracy can be improved. In addition, when it is determined that the cam does not operate normally at the time of the first failure determination, it is also possible to determine whether or not the cam has returned to a state in which the cam can be normally operated by subsequent operation of the drive source.

When it is determined that the cam does not operate normally by the failure determination at the time when the activation request is generated, the failure determination means may not permit the valve opening based on the activation request. At that time, by prohibiting the operation of the fuel injection valve and the spark plug, various problems as described above can be avoided.

  In the invention as described above, as a method of determining whether or not the cam is normally rotating or swinging, (1) the cam is normally operated based on the detection signal of the means for detecting the rotational position of the drive source. A method of determining whether or not the cam is rotating or swinging, and (2) a method of determining whether or not the cam is rotating or swinging normally based on the detection signal of the means for detecting the rotational position of the cam. It can be illustrated.

  In the present invention, as a method of determining whether or not the cam is rotating or swinging normally, the cam is normally operated based on a detection signal of a means for detecting a driving torque (requested torque) required for the driving source. A method for determining whether or not it is rotating or swinging can also be exemplified. The required torque of the drive source increases when the cam lifts the valve. For this reason, if increase / decrease in the required torque commensurate with the lift amount of the valve and the rotation direction of the cam occurs, it can be determined that the cam is rotating or swinging normally.

  However, when the cam is swung within the range where the valve does not lift, the required torque of the drive source does not increase or decrease. In such a case, the means for detecting the rotational position of the drive source or the means for detecting the rotational position of the cam It is preferable to determine whether or not the cam is swinging normally based on the detection signal.

  According to the present invention, in a valve operating system for an internal combustion engine in which a valve rotated or swung by a drive source independent of the internal combustion engine opens and closes the valve, whether the cam can be operated as required when the drive source is activated. Can be detected.

  Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

<Example 1>
First, a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a diagram showing a schematic configuration of a valve operating system for an internal combustion engine according to the present invention.

  The internal combustion engine 1 shown in FIG. 1 is a 4-stroke cycle spark ignition internal combustion engine (gasoline engine).

  The internal combustion engine 1 includes four cylinders 2. A piston 3 is slidably mounted in the cylinder 2. The piston 3 is connected to the crankshaft 5 via a connecting rod 4.

  The inside of the cylinder 2 communicates with the intake port 6 and the exhaust port 7. The opening end of the intake port 6 in the cylinder 2 is opened and closed by an intake valve 8. An open end of the exhaust port 7 in the cylinder 2 is opened and closed by an exhaust valve 9. The intake valve 8 and the exhaust valve 9 are respectively opened and closed by an intake side drive mechanism 10 and an exhaust side drive mechanism 11.

  The intake port 6 communicates with the intake passage 60. A fuel injection valve 12 is attached to the intake passage 60. The intake air flowing through the intake passage 60 is guided to the intake port 6. The intake air guided to the intake port 6 is sucked into the cylinder 2 when the intake valve 8 is opened. At that time, the fuel injected from the fuel injection valve 12 to the intake port 6 is also taken into the cylinder 2 together with the intake air.

  The fuel and the intake air (air mixture) guided into the cylinder 2 are burned using the spark generated by the spark plug 13 as a spark. Gas burned in the cylinder 2 (burned gas) is discharged to the exhaust port 7 when the exhaust valve 9 is opened. The exhaust port 7 communicates with the exhaust passage 70, and the burnt gas described above is discharged from the exhaust port 7 into the atmosphere through the exhaust passage 70.

  The internal combustion engine 1 configured as described above is provided with an ECU 14. The ECU 14 is an electronic control unit that includes a CPU, a ROM, a RAM, a backup RAM, and the like. The ECU 14 is electrically connected to various sensors such as a crank position sensor 15, a water temperature sensor 16, and an ignition switch 17.

  The ECU 14 electrically controls the fuel injection valve 12, the spark plug 13, the intake side drive mechanism 10, and the exhaust side drive mechanism 11 based on the measurement values of the various sensors described above.

  Here, the configuration of the intake side drive mechanism 10 and the exhaust side drive mechanism 11 will be described with reference to FIGS. FIG. 2 is a diagram showing the configuration of the intake side drive mechanism 10. 2 represent the first to fourth cylinders of the internal combustion engine 1, respectively. The order of combustion from the first cylinder (# 1) to the fourth cylinder (# 4) is as follows: first cylinder (# 1) → third cylinder (# 3) → fourth cylinder (# 4) → second cylinder ( # 2).

  Two intake valves 8 are provided in each of the first cylinder (# 1) to the fourth cylinder (# 4). A valve lifter 80 is attached to the stem base end of the intake valve 8. A biasing force of a valve spring (not shown) acts on the intake valve 8, and the valve lifter 80 is pressed against the first intake cam 81 or the second intake cam 82 by the biasing force.

  The first intake cam 81 is a cam that opens and closes the intake valves 8 of the first cylinder (# 1) and the fourth cylinder (# 4), and is fixed to the first intake camshaft 83. The second intake cam 82 is a cam that opens and closes the intake valves 8 of the second cylinder (# 2) and the third cylinder (# 3), and is fixed to the second intake camshaft 84.

  The first intake camshaft 83 and the second intake camshaft 84 are arranged coaxially and are supported by the internal combustion engine 1 so as to be rotatable or swingable in the circumferential direction independently of each other.

  A first driven gear 85 is fixed to one end of the first intake camshaft 83. The first driven gear 85 meshes with the first output gear 19 fixed to the output shaft of the first motor 18. Hereinafter, the first driven gear 85 and the first output gear 19 are collectively referred to as a first reduction mechanism.

  In this case, the rotational torque of the first motor 18 is transmitted to the first intake camshaft 83 via the first reduction mechanism. Therefore, the first motor 18 can rotate or swing the first intake camshaft 83 in the circumferential direction via the first reduction mechanism.

  A second driven gear 86 is coaxially fixed to a part of the outer peripheral surface of the second intake camshaft 84. The second driven gear 86 is meshed with the intermediate gear 87. The intermediate gear 87 meshes with the second output gear 22 fixed to the output shaft of the second motor 21. Hereinafter, the second driven gear 86, the intermediate gear 87, and the second output gear 22 are collectively referred to as a second reduction mechanism. The reduction ratio by the second reduction mechanism is the same as that of the first reduction mechanism described above.

  In this case, the rotational torque of the second motor 21 is transmitted to the second intake camshaft 84 via the second reduction mechanism. Therefore, the second motor 21 can rotate or swing the second intake camshaft 84 in the circumferential direction via the second reduction mechanism.

  The first motor 18 includes a first resolver 20 that detects a rotation angle (phase) of the output shaft, and a detection signal of the first resolver 20 is input to the ECU 14. The second motor 21 includes a second resolver 23 that detects the rotation angle of the output shaft, and a detection signal of the second resolver 23 is input to the ECU 14.

  Next, FIG. 3 is a diagram showing a configuration of the exhaust side drive mechanism 11. In FIG. 3, two exhaust valves 9 are provided in each of the first cylinder (# 1) to the fourth cylinder (# 4). A valve lifter 90 is attached to the stem base end of the exhaust valve 9. A biasing force of a valve spring (not shown) acts on the exhaust valve 9, and the valve lifter 90 is pressed against the exhaust cam 91 by the biasing force.

  The exhaust cams 91 of all cylinders are fixed to one exhaust cam shaft 92. A third driven gear 93 is fixed to one end of the exhaust camshaft 92. The third driven gear 93 meshes with the third output gear 25 attached to the output shaft of the third motor 24. Hereinafter, the third driven gear 93 and the third output gear 25 are collectively referred to as a third reduction mechanism.

  In this case, the rotational torque of the third motor 24 is transmitted to the exhaust camshaft 92 via the third output gear 25 and the third driven gear 93. Therefore, the third motor 24 can rotate or swing the exhaust camshaft 92 in the circumferential direction via the third reduction mechanism.

  The third motor 24 includes a third resolver 26 that detects the rotation angle (phase) of the output shaft, and a detection signal of the third resolver 26 is input to the ECU 14.

  The first motor 18, the second motor 21, and the third motor 24 described above correspond to a drive source according to the present invention. Moreover, the 1st resolver 20, the 2nd resolver 23, and the 3rd resolver 26 are corresponded to the 1st detection means concerning this invention.

  In the valve train configured as described above, the ECU 14 rotates or swings the first motor 18, the second motor 21, and the third motor 24 at the timing synchronized with the rotation of the crankshaft 5. The intake valve 8 and the exhaust valve 9 of the cylinder (# 1) to the fourth cylinder (# 4) can be opened and closed at a timing synchronized with the rotation of the crankshaft 5.

  By the way, when each motor starts to rotate from a stopped state, a relatively large starting power is required. Furthermore, relatively large friction is generated when each camshaft starts to rotate from a stopped state. Therefore, when each motor starts rotating each camshaft in a stopped state (during start-up), relatively large power is required. For this reason, there is a possibility that each camshaft does not rotate or swing as required when each motor is started.

  Examples of the case where an activation request is generated for each motor include an example of when the internal combustion engine 1 is started, when returning from reduced-cylinder operation, when returning from deceleration fuel cut operation, or when preheat operation ends. it can.

  During the reduced-cylinder operation of the internal combustion engine 1, the operation of some of the cylinders 2 (hereinafter referred to as “paused cylinders”) is deactivated. At this time, the intake valve 8 and / or the exhaust valve 9 of the deactivated cylinder 2 are deactivated (fully closed), thereby reducing the pumping loss and suppressing the fluctuation of the exhaust air-fuel ratio. Therefore, when returning from the reduced cylinder operation, a motor activation request corresponding to the intake valve 8 and / or the exhaust valve 9 of the deactivated cylinder 2 is generated.

During the deceleration fuel cut operation of the internal combustion engine 1, the intake valve 8 and / or the exhaust valve 9 are stopped (fully closed) to suppress the temperature reduction of the exhaust purification device (three-way catalyst, NOx catalyst, etc.). it can. Therefore, when the internal combustion engine 1 returns from the deceleration fuel cut operation state, a start request for each motor is generated.

  The preheat operation is an operation in which the exhaust valve 9 is stopped (fully closed) during cranking of the internal combustion engine 1 and the lift amount of the intake valve 8 is limited to increase the atmospheric temperature in the cylinder 2. For this reason, at the end of the preheat operation, an activation request for the third motor 24 is generated.

  The activation request as described above may occur after the operation of the fuel injection valve 12 or the spark plug 13. In such a case, if the motor cannot rotate or swing the camshaft as required, unburned fuel remains in the intake port 6 or the cylinder 2, or the burned gas in the cylinder 2 is taken into the intake air. Problems such as noise and heat damage caused by backflow to the system (intake port 6 and intake passage 60) occur.

  Therefore, the ECU 14 forcibly activates each motor to make a failure determination before a normal activation request for each motor is generated. Hereinafter, a method for executing the failure determination process in the present embodiment will be described.

  In the failure determination process, the ECU 14 first forcibly starts each motor before a normal start request is generated. At that time, the ECU 14 controls each motor so that each camshaft rotates at least once.

  The timing for forcibly starting each motor is preferably before the operation of the fuel injection valve 12 is started. This is because when each camshaft makes one rotation after the operation of the fuel injection valve 12 is started, the fuel flows out to the exhaust system (exhaust port 7 and exhaust passage 70) while the fuel is unburned by the opening / closing operation of the intake valve 8 and exhaust valve 9. This is because there is a possibility of backflow to the intake system.

  ECU14 discriminate | determines whether each camshaft is rotating normally based on the detection signal of the resolver of each motor. The state where the camshaft is not rotating normally includes not only the state where the camshaft is not rotating but also the state where the rotational speed of each camshaft is far from the target value. This is because if the rotational speed of each camshaft is far from the target value, the intake valve 8 and / or the exhaust valve 9 cannot be opened and closed at a timing synchronized with the rotation of the crankshaft.

  If the ECU 14 detects a camshaft that does not rotate normally, the ECU 14 may stop the subsequent operation, or may continue the operation using only the camshaft that can rotate normally.

  For example, when it is determined that the first intake camshaft 83 is not rotating normally, the ECU 14 prohibits the operation of the first cylinder (# 1) and the fourth cylinder (# 4) (the first cylinder (## 1) and the operation of the fuel injection valve 12 and the spark plug 13 of the fourth cylinder (# 4) are prohibited, and the operation of the second cylinder (# 2) and the third cylinder (# 3) is continued, A vehicle equipped with the internal combustion engine 1 may be allowed to retreat.

  When it is determined that the second intake camshaft 84 is not rotating normally, the ECU 14 prohibits the operation of the second cylinder (# 2) and the third cylinder (# 3) (second cylinder (# 2)). And the operation of the fuel injection valve 12 and the spark plug 13 of the third cylinder (# 3) are prohibited, and the operation of the first cylinder (# 1) and the fourth cylinder (# 4) is continued, whereby the internal combustion engine A vehicle equipped with 1 may be allowed to retreat.

  When it is determined that the exhaust camshaft 92 is not rotating normally, the ECU 14 prohibits the operation of all the cylinders 2 (prohibits the operation of the fuel injection valves 12 and the spark plugs 13 of all the cylinders). Good.

  When the ECU 14 detects a camshaft that is not normally rotating, the ECU 14 may notify the driver of the occurrence of a failure using an output device (for example, a lamp, a speaker, or a display) disposed in the vehicle interior. desirable.

  As described above, if a failure determination is made before a normal start-up request is generated for each motor, unburned fuel is introduced into the intake port 6 and the cylinder 2 when a camshaft that does not rotate normally is detected. It is possible to avoid the problem that the residual gas remains or the burned gas in the cylinder 2 flows back to the intake port 6 and the intake passage 60 to cause noise and heat damage.

  Here, FIG. 4 shows an example in which the failure determination process of the exhaust camshaft 92 is performed when the internal combustion engine 1 is started (during cranking). In FIG. 4, L1, L2, L3, and L4 are exhaust valves of the first cylinder (# 1), the second cylinder (# 2), the third cylinder (# 3), and the fourth cylinder (# 4), respectively. A lift amount of 9 is shown.

  In the example shown in FIG. 4, the ECU 14 rotates the exhaust camshaft 92 once before the start-up request is generated and before the first fuel injection (fuel injection to the first cylinder (# 1) in FIG. 4). Therefore, the third motor 24 is forcibly started.

  At that time, the ECU 14 determines that the exhaust valve 9 of each cylinder 2 is opened during a period in which the piston 3 of each cylinder 2 is located near the bottom dead center (for example, a period from the latter half of the expansion stroke to the first half of the exhaust stroke). 3 The motor 24 is controlled. This is to avoid interference between the exhaust valve 9 and the piston 3.

  When the third motor 24 is forcibly started, the ECU 14 determines whether or not the exhaust camshaft 92 is rotating based on the detection signal of the third resolver 26 and the difference between the rotational speed and the target value at that time. It is determined whether it is within the range.

  The ECU 14 permits the operation of the fuel injection valve 12 and the spark plug 13 when it is determined that the exhaust camshaft 92 has normally rotated once. On the other hand, when the ECU 14 determines that the exhaust camshaft 92 has not normally rotated once, the ECU 14 prohibits the operation of the fuel injection valve 12 and the spark plug 13.

  The ECU 14 determines the failure of the first motor 18 and the second motor 21 by the same method. At that time, the ECU 14 performs the first intake camshaft at the timing when the intake valve 8 opens during the period in which the piston 3 of each cylinder 2 is located near the bottom dead center (for example, the period from the latter half of the intake stroke to the first half of the compression stroke). The first motor 18 and the second motor 21 may be forcibly started so that the motor 83 and the second intake camshaft 84 rotate once.

  Whether or not the intake valves 8 and the exhaust valves 9 of all the cylinders 2 normally open and close when the failure determination process is performed by rotating each camshaft once (in other words, can the valve be opened to the maximum lift amount)? Or not). Furthermore, when each camshaft makes one rotation, the lubricant can be spread over the entire sliding surface of the camshaft, so that the load on each motor when a regular start-up request is generated can be reduced. The shaft is likely to rotate normally.

  Hereinafter, the execution procedure of the failure determination process in the present embodiment will be described with reference to FIG. FIG. 5 is a flowchart showing a failure determination processing routine. The failure determination processing routine is a routine stored in advance in the ROM of the ECU 14. This failure determination processing routine is periodically executed by the ECU 14 when the ignition switch 17 is turned on.

  In the failure determination processing routine, the ECU 14 first determines whether or not there is a stopped camshaft among the first intake camshaft 83, the second intake camshaft 84, and the exhaust camshaft 92 in S101.

  If a negative determination is made in S101, the ECU 14 ends the execution of this routine. On the other hand, when a positive determination is made in S101, the ECU 14 proceeds to S102.

  In S102, the ECU 14 forcibly starts the motor to rotate the camshaft in a stopped state once. At that time, the ECU 14 controls the motor so that the valve opened and closed by the cam provided on the cam shaft is opened at a timing that does not interfere with the piston 3 as described above.

  In S103, the ECU 14 determines whether or not the camshaft is normally rotating based on the detection signal of the resolver of the motor forcibly started in S102.

  Here, the relationship between the detection signal of the first resolver 20 and the phase of the first intake cam 81 is shown in FIG. In FIG. 6, the rotation speed ratio of the output shaft of the first motor 18 to the first intake camshaft 83 is 2 (the output shaft of the first motor 18 rotates twice while the first intake camshaft 83 makes one rotation). is there. In this case, the ECU 14 can rotate the first intake camshaft 83 once by controlling the first motor 18 to rotate twice.

  FIG. 7 shows a detection signal of the first resolver 20 when the first intake camshaft 83 does not rotate, and FIG. 8 shows the first resolver 20 when the rotation speed of the first intake camshaft 83 is far from the target value. A detection signal is shown. The solid line in FIG. 8 indicates a detection signal at the time of failure, and the alternate long and short dash line in FIG. 8 indicates a detection signal at a normal time.

  When the first intake camshaft 83 does not rotate at all, the detection signal of the first resolver 20 shows a constant value. When the rotational speed of the first intake camshaft 83 becomes slower than the target value, the crank angle Δt (CA) required for the first intake camshaft 83 to make one rotation becomes longer than the target value Δt (CA).

  Therefore, the ECU 14 determines that the first intake camshaft 83 is not rotating normally (failure determination) when the detection signal of the first resolver 20 shows the mode as shown in FIGS. On the other hand, the ECU 14 determines that the first intake camshaft 83 is rotating normally when the detection signal of the first resolver 20 shows an aspect as indicated by the one-dot chain line in FIG.

  Here, returning to the failure determination processing routine of FIG. 5, if it is determined in S103 that the camshaft is rotating normally, the ECU 14 stops the forced operation of the motor and ends the execution of this routine. . On the other hand, if it is determined in S103 that the camshaft is not rotating normally, the ECU 14 proceeds to S104.

  In S104, the ECU 14 prohibits the operation of the fuel injection valve 12 and the spark plug 13 of the cylinder 2 provided with a valve that is opened and closed by the camshaft.

  In S105, the ECU 14 notifies the driver of the occurrence of the failure using an output device provided in the passenger compartment.

  As described above, when the ECU 14 executes the failure determination processing routine, the control means and the failure determination means according to the present invention are realized. Therefore, according to the present embodiment, it is possible to determine whether or not each camshaft is normally operable before the fuel injection valve 12 and the spark plug 13 are activated. As a result, unburned fuel remains in the intake port 6 and the cylinder 2 or burned gas in the cylinder 2 flows back to the intake port 6 and the intake passage 60 to cause noise and heat damage. It can be avoided.

<Example 2>
Next, a second embodiment of the present invention will be described with reference to FIGS. Here, a configuration different from the first embodiment described above will be described, and the description of the same configuration will be omitted.

  In the first embodiment described above, an example has been described in which failure determination is performed by forcibly starting each motor before a normal start request is generated for each motor.

  If each motor is stopped after the failure determination of each motor is completed, the load applied to each motor increases when a normal activation request is generated, and therefore, each camshaft may not rotate normally. Therefore, in the failure determination process of the present embodiment, each motor is continuously operated until each motor is forcibly activated until a normal activation request is generated.

  By the way, the fuel injection valve 12 and the spark plug 13 may operate before a normal activation request is generated. For this reason, if the intake valve 8 and the exhaust valve 9 are inadvertently opened, various problems as described above may occur.

  On the other hand, the ECU 14 controls each motor so that each camshaft rotates at least once before the operation of the fuel injection valve 12 and the spark plug 13 (first control), and thereafter, in a range where each valve does not lift. Each motor is controlled (second control) so that the camshaft swings.

  Further, the ECU 14 performs the failure determination both when the first control is executed and when the second control is executed. The failure determination may be continued until a normal activation request is generated, or may be terminated when the fuel injection valve 12 is operated or when the spark plug 13 is operated.

  When a failure is determined by such a method, each motor and each camshaft operate without interruption until each motor is forcibly activated until a normal activation request is generated. It becomes easy to operate. As a result, the reliability of the failure determination result and the reliability of the valve train can be enhanced. Furthermore, in addition to whether or not each camshaft can normally rotate, it can also be determined whether or not each camshaft can swing normally, so that failure determination accuracy can be improved.

  If a failure is detected during rotation or swinging of each camshaft, the subsequent operation may be stopped or normally rotated and swung as in the first embodiment. Operation may be continued with the camshaft.

FIG. 9 is a diagram illustrating an example in which a failure determination process for the exhaust camshaft 92 is performed when the internal combustion engine 1 is started (during cranking). In FIG. 9, when the ECU 14 forcibly starts the third motor 24, the ECU 14 first controls the third motor 24 to rotate the exhaust camshaft 92 once, and the exhaust cam based on the detection signal of the third resolver 26. It is determined whether or not the shaft 92 has normally rotated once (see the rotation period in FIG. 9).

  If it is determined that the exhaust camshaft 92 has normally rotated once during the rotation period, the ECU 14 controls the third motor 24 to swing the exhaust camshaft 92 until a normal activation request is generated. Based on the detection signal of the third resolver 26, it is determined whether or not the exhaust camshaft 92 is normally swinging (see the swinging period in FIG. 9).

  At that time, the ECU 14 swings the exhaust camshaft 92 within a range where none of the exhaust valves 9 of the first cylinder (# 1) to the fourth cylinder (# 4) is opened. For example, as shown in FIG. 10, the ECU 14 moves the third motor 24 so that the exhaust camshaft 92 swings within a range where the base circle of the exhaust cam 91 contacts the valve lifter 90 (A in FIG. 10). Control.

  As for the first intake camshaft 83 and the second intake camshaft 84, as shown in FIGS. 11 and 12, the range in which the base circle portion of the first intake cam 81 contacts the valve lifter 80 (in FIG. 11 and FIG. 12). In B), the first intake camshaft 83 and the second intake camshaft 84 are swung.

  Next, the execution procedure of the failure determination process in the present embodiment will be described with reference to FIG. FIG. 13 is a flowchart showing a failure determination processing routine. In FIG. 13, the same steps as those in the failure determination processing routine (see FIG. 5) of the first embodiment described above are denoted by the same reference numerals.

  In the failure determination processing routine, if the ECU 14 determines in S103 that the camshaft has rotated normally, the ECU 14 proceeds to S201. In S201, the ECU 14 controls the motor to shift the camshaft from the rotating state to the swinging state.

  By the way, when the internal combustion engine 1 is started or preheated, the ECU 14 can accurately grasp the start request generation timing. However, the start request generation timing associated with the return from the deceleration operation state and the start request generation timing associated with the return from the reduced cylinder operation state may vary depending on the operation of the driver.

  Therefore, if the fuel injection valve 12 or the spark plug 13 is operated before the camshaft makes one revolution, the ECU 14 may control the motor to shift the camshaft from the rotating state to the swinging state at that time. Good. That is, the ECU 14 controls the motor to rotate the camshaft until the fuel injection valve 12 or the ignition plug 13 is operated, and swings the camshaft after the fuel injection valve 12 or the ignition plug 13 is operated. Therefore, the failure determination process may be performed by controlling the motor as much as possible.

  When the rotation control and the swing control are switched in this way, the unburned fuel flows backward to the intake system or the exhaust system, or the burned gas (or gas in the middle of combustion) is ejected to the intake system or the exhaust system. Is reliably prevented.

  In S202, the ECU 14 determines whether or not the camshaft is swinging normally based on a detection signal from the resolver of the motor. Specifically, the ECU 14 detects whether or not the resolver has detected whether or not the camshaft has normally rotated forward and reverse, and whether or not the difference between the forward / reverse rotation speed and the target value is within an allowable range. Discriminate based on the signal.

If it is determined in S202 that the camshaft is not swinging normally, the ECU 14 proceeds to S105. On the other hand, if it is determined in S202 that the camshaft is swinging normally, the ECU 14 proceeds to S203.

  In S203, the ECU 14 determines whether or not a regular activation request has occurred. If a negative determination is made in S203, the ECU 14 returns to S201. On the other hand, if an affirmative determination is made in S203, the ECU 14 ends the execution of the failure determination process and controls the motor to rotate or swing the camshaft in accordance with a normal activation request.

  As described above, when the ECU 14 executes the failure determination processing routine of FIG. 13, it can be determined whether or not the camshaft can rotate normally, and the camshaft can swing normally. It can also be determined whether or not. As a result, the failure determination accuracy is increased.

  Furthermore, after it is determined that the camshaft rotates normally, the camshaft continues to swing until a normal start request is generated. Therefore, when the normal start request is generated, the motor normally rotates or swings the camshaft. It can be moved. At this time, since the camshaft is swung within a range in which the intake valve 8 and / or the exhaust valve 9 is not opened (lifted), the internal combustion engine 1 can be operated even after the fuel injection valve 12 and the spark plug 13 are activated. The camshaft can be continuously swung without affecting the operating state.

  Note that the timing at which the motor is forcibly started may be set to a time obtained by subtracting the time required for executing the failure determination process from the start request generation time. In this case, since the camshaft swing period is as short as possible, an increase in power consumption due to the execution of the failure determination process can be minimized.

<Example 3>
Next, a third embodiment of the present invention will be described with reference to FIG. Here, a configuration different from the second embodiment described above will be described, and description of the same configuration will be omitted.

  In the second embodiment described above, an example has been described in which both rotation control and swing control are always executed when each motor is forcibly started.

  When the stop period of the motor (and the camshaft) becomes longer, the oil film on the sliding portion of the cam or valve becomes thinner or the viscosity of the lubricating oil becomes higher. In such a case, the friction when the cam or valve starts to operate increases.

  On the other hand, when the motor stop period is short, the oil film of the sliding portion of the cam or valve maintains a sufficient thickness and the viscosity of the lubricating oil decreases. In such a case, the friction when the cam or valve starts to operate becomes small.

  Therefore, it can be said that the shorter the motor stop period, the easier the camshaft rotates. For this reason, when the stop period of the motor is short, it can be considered that the camshaft can normally rotate if the camshaft can swing normally.

  Therefore, in the failure determination process of the present embodiment, the ECU 14 performs both rotation control and swing control when the motor stop period is long, and performs only swing control when the motor stop period is short. I made it.

  When the failure determination process is performed by such a method, an increase in power consumption due to the execution of the failure determination process can be minimized while suppressing a decrease in failure determination accuracy.

  Hereinafter, the execution procedure of the failure determination process in the present embodiment will be described with reference to FIG. FIG. 14 is a flowchart showing a failure determination processing routine in the present embodiment. In FIG. 14, the same reference numerals are assigned to the steps equivalent to the failure determination processing routine (see FIG. 13) of the second embodiment described above.

  In the failure determination processing routine, the ECU 14 proceeds to S301 when an affirmative determination is made in S101. In S301, it is determined whether or not the camshaft stop period is equal to or longer than a certain period. As a determination method, (1) a counter for measuring the stop time of the motor is provided, and a method for determining whether or not the measurement time of the counter is equal to or longer than a certain period (in this case, the constant period of cam or valve (This corresponds to the time required for the oil film of the sliding portion to become thinner than the allowable range, and the time required for the viscosity of the lubricating oil to become higher than the allowable range), (2) the measured value of the water temperature sensor 16 (cooling water) When the temperature is lower than the reference water temperature, a method is considered in which the stop period is longer than a certain period, or (3) a sensor for measuring the temperature of the lubricating oil of the internal combustion engine 1 is provided, and the measured value (oil temperature) of the sensor is For example, when the temperature is lower than the reference oil temperature, it is possible to exemplify a method in which the stop period is regarded as a certain period or longer.

  If an affirmative determination is made in S301, the ECU 14 proceeds to S102. In this case, the ECU 14 determines the failure by controlling (rotational control) the motor to rotate the camshaft at least once, and determines the failure by controlling the motor (swing control) to swing the camshaft. .

  On the other hand, if a negative determination is made in S301, the ECU 14 proceeds to S201. In this case, the ECU 14 performs failure determination by executing only the swing control. However, if it is determined that the camshaft does not rotate or swing normally at the time of the previous failure determination, both rotation control and swing control are executed even if the camshaft stop period is equal to or less than a certain period. You may do it.

  As described above, when the ECU 14 executes the failure determination processing routine, the control means, the failure determination means, and the determination means according to the present invention are realized. As a result, an increase in power consumption due to the execution of the failure determination process can be minimized while suppressing a decrease in failure determination accuracy.

<Example 4>
Next, a fourth embodiment of the present invention will be described. Here, configurations different from those of the first to third embodiments described above will be described, and description of similar configurations will be omitted.

  In the first to third embodiments described above, an example is described in which failure determination is performed when each motor is in a stopped state before a normal start request is generated. In this embodiment, an example will be described in which failure determination is performed regardless of whether each motor is in a stopped state.

  The ECU 14 periodically performs a failure determination process when the ignition switch 17 is on. If each motor is in a stopped state when executing the failure determination processing, the ECU 14 executes the failure determination processing by any of the methods described in the first to third embodiments. Further, the ECU 14 determines whether each camshaft rotates or swings in a state suitable for the operating condition of the internal combustion engine 1 when each motor is in an operating state when executing the failure determination process.

After completing the failure determination process, the ECU 14 continuously operates each motor until the next start request is generated even if a stop request for each motor is generated. The stop request here is a stop request for the purpose of stopping or stopping the valve in the deceleration fuel cut operation or the reduced cylinder operation, and the stop request accompanying the operation stop of the internal combustion engine 1 (off of the ignition switch 17). Is not included. Therefore, if the ignition switch 17 is switched from on to off before the next activation request is generated after the execution of the failure determination process, the ECU 14 ends the forced operation of each motor.

  If each motor is forcibly continuously operated from the end of execution of the failure determination process until the next start-up request is generated, the reliability of the failure determination result can be improved. For example, if the operation of each motor is stopped after the execution of the failure determination process, each camshaft may not operate normally when the next activation request is generated. For this reason, even if it is determined by the failure determination process that the camshaft has operated normally, a situation may occur in which the camshaft does not operate normally at the next start-up. On the other hand, if each motor is forcibly continuously operated from the end of execution of the failure determination process until the next start-up request is generated, the occurrence of the above situation can be avoided.

  When a failure determination process is performed when each motor is in operation and a camshaft that does not operate normally is detected, the ECU 14 performs fuel injection in the cylinder 2 provided with a valve that is opened and closed by the camshaft. The operation of the motor that drives the camshaft may be continued while prohibiting the operation of the valve 12 and the spark plug 13.

  This is because if the oil film is formed, the temperature of the lubricating oil is increased, or the viscosity of the lubricating oil is decreased by the continuous operation of the motor, the camshaft may return to a state where it can operate normally.

  In order to determine whether or not the camshaft has returned to a normally operable state, failure determination processing may be periodically performed in a period from the end of failure determination to the next activation request occurrence, Alternatively, the failure determination process may be performed again when the next activation request is generated.

  As a preferable aspect for performing the failure determination process again when the next activation request is generated, an aspect in which the valve that is opened and closed by the camshaft when the next activation request is generated is in a closed state can be exemplified.

  If the valve that is opened and closed by the camshaft is in the closed state when the next activation request is generated, the ECU 14 causes the camshaft to swing so that the valve does not lift before operating the motor according to the activation request. It can be operated, and it can also be determined whether or not the camshaft is swinging normally.

  Therefore, it is possible to determine whether the camshaft can operate normally without affecting the operating state of the internal combustion engine 1. As a result, the reliability of the failure determination result and the reliability of the valve train can be improved.

  By the way, if the interval from the end of execution of the failure determination process (specifically, when a stop request occurs after execution of the failure determination process) to the next start request generation becomes excessively long, the power consumption is increased by the forced operation of each motor. Can be enormous. Therefore, when the next activation request does not occur within a certain time from the end of the failure determination, the ECU 14 may end the forced operation of each motor when a certain time has elapsed from the end of the failure determination. In this case, an excessive increase in power consumption can be prevented.

In the first to fourth embodiments described above, the method for determining whether or not the camshaft is normally rotating or swinging based on the detection signal of the resolver is exemplified. If a sensor is provided, it may be determined whether the camshaft is rotating or swinging normally based on the measured value of the cam position sensor. Further, it may be determined whether or not the camshaft is rotating normally based on increase / decrease in the required drive torque of each motor.

It is a figure which shows schematic structure of the valve operating system of an internal combustion engine. It is a figure which shows the structure of an intake side drive mechanism. It is a figure which shows the structure of an exhaust side drive mechanism. It is a timing chart which shows the failure determination method of an exhaust camshaft in a 1st Example. It is a flowchart which shows the failure determination processing routine in a 1st Example. It is a figure which shows the relationship between the detection signal of a 1st resolver, and the phase of a 1st intake cam. It is a figure which shows the detection signal of a 1st resolver when a 1st intake camshaft does not rotate. It is a figure which shows the detection signal of a 1st resolver in case the rotational speed of a 1st intake camshaft is far from target value. It is a timing chart which shows the failure determination method of an exhaust camshaft in 2nd Example. It is a figure which shows the rocking | fluctuation range of an exhaust camshaft. It is a figure which shows the rocking | fluctuation range of a 1st intake camshaft. It is a figure which shows the rocking | fluctuation range of a 2nd intake camshaft. It is a flowchart which shows the failure determination processing routine in a 2nd Example. It is a flowchart which shows the failure determination processing routine in a 3rd Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Internal combustion engine 2 ... Cylinder 6 ... Intake port 7 ... Exhaust port 8 ... Intake valve 9 ... Exhaust valve 10 ... ..Intake side drive mechanism 11 ... Exhaust side drive mechanism 12 ... Fuel injection valve 13 ... Ignition plug 14 ... ECU
15 .... Crank position sensor 18 .... first motor 19 .... first output gear 20 .... first resolver 21 ...... second motor 22 .... second output gear 23 ... Second resolver 24 ... Third motor 25 ... Third output gear 26 ... Third resolver 60 ... Intake passage 70 ... Exhaust passage 80 ... ··· Valve lifter 81 ··· First intake cam 82 ··· Second intake cam 83 ··· First intake camshaft 84 · · · Second intake camshaft 85 · · · 1st driven gear 86 .... Second driven gear 87 ... Intermediate gear 90 ... Valve lifter 91 ... Exhaust cam 92 ... Exhaust cam shaft 93 ... Third driven gear

Claims (15)

In a valve operating system for an internal combustion engine in which a cam rotated or swung by a drive source independent of the internal combustion engine opens and closes the valve,
Control means for forcibly starting the drive source before the start request is generated for the stopped drive source;
Failure determination means for determining whether or not the cam has normally operated when the drive source is forcibly activated by the control means;
A valve operating system for an internal combustion engine, comprising:   2. The valve operating system for an internal combustion engine according to claim 1, wherein the control means controls the drive source so that the cam rotates at least once when the drive source is forcibly activated.   2. The operation of the internal combustion engine according to claim 1, wherein the control means controls the drive source so that the cam swings within a range in which the valve does not lift when the drive source is forcibly started. Valve system.   2. The control unit according to claim 1, wherein the control unit controls the drive source so that the cam rotates at least once when the drive source is forcibly activated, and the cam is operated within a range in which the valve does not lift. A valve operating system for an internal combustion engine, wherein a second control for controlling the drive source so as to swing is performed. In any one of Claims 1-4, the said control means continues the operation | movement of the said drive source until the said start request | requirement generate | occur | produces after forcibly starting the said drive source,
The failure determination means continues to determine whether or not the cam is operating normally while the operation of the drive source is continued by the control means. . In Claim 4, It further has a discriminating means which discriminates whether the stop period of the above-mentioned drive source is beyond a fixed period,
The control unit executes the first control and the second control when the determination unit determines that the stop period of the drive source is equal to or longer than a predetermined period, and the determination unit performs the stop period of the drive source. Is determined to be less than a certain period, only the second control is performed.   7. The valve operating system for an internal combustion engine according to claim 6, wherein when the temperature of the cooling water of the internal combustion engine is lower than a reference water temperature, the determination means regards that the stop period of the drive source is a certain period or longer. .   8. The operation of the internal combustion engine according to claim 1, wherein the control means forcibly starts the drive source before the start of the fuel injection valve before the start request is generated. Valve system.   8. The valve of an internal combustion engine according to claim 1, wherein the control means forcibly starts the drive source before the start of the ignition plug before the start request is generated. system. 8. The valve operating system for an internal combustion engine according to claim 1, wherein the control means forcibly starts the drive source at a time obtained by subtracting a time required for failure determination from the time when the start request is generated. . In a valve operating system for an internal combustion engine in which a cam rotated or swung by a drive source independent of the internal combustion engine opens and closes the valve,
Failure determination means for determining whether or not the cam has operated normally;
Control means for forcibly continuing the operation of the drive source until the next start-up request is generated from the end of the failure determination by the failure determination means,
A valve operating system for an internal combustion engine, comprising:   12. The control unit according to claim 11, wherein when the next activation request does not occur within a predetermined time from the end of the failure determination by the failure determination unit, the control unit stops the operation of the drive source when the predetermined time has elapsed. A valve operating system for an internal combustion engine. In Claim 11 or 12, when the valve is in a fully closed state when the next activation request is generated, the control means does not lift the valve before opening the valve in accordance with the activation request. Controlling the drive source to swing the cam;
The failure determination means determines whether or not the cam operates normally when the control means controls the drive source to swing the cam, and determines that the cam operates normally. In this case, the valve operating system for the internal combustion engine is allowed to open the valve based on the start request. In any 1 paragraph of Claims 1-13, The 1st detection means which detects the rotation position of the drive source is further provided,
The valve operating system for an internal combustion engine, wherein the failure determination means determines whether or not the cam is normally rotating or swinging based on a detection signal of the first detection means. In any 1 paragraph of Claims 1-13, It further has the 2nd detection means which detects the drive torque demanded of the above-mentioned drive source,
The valve operating system for an internal combustion engine, wherein the failure determination means determines whether or not the cam is normally rotating or swinging based on a detection signal of the second detection means.

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