JP4233308B2 - Valve timing control device for internal combustion engine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The invention of this application relates to a valve timing control device for an internal combustion engine that variably controls the opening / closing timing of an intake-side or exhaust-side engine valve of the internal combustion engine in accordance with an operating state.
[0002]
[Prior art]
As this type of valve timing control device, the following has been devised.
[0003]
In this valve timing control device, a housing (drive rotary member) linked to a crankshaft via a timing chain or the like is rotatably assembled to an end portion of a camshaft, and a radial guide formed on an inner end surface of the housing. The movable guide is slidably engaged and supported along the radial direction, and a lever shaft (driven rotor) having a lever protruding radially outward is bolted to the end of the camshaft, so that the movable guide The part and the lever of the lever shaft are pivotally connected by a link. An intermediate rotating body having a spiral guide is provided at a position facing the radial guide so as to be rotatable relative to the housing and the lever shaft, and is provided at one end in the axial direction of the movable guide portion. A plurality of substantially arc-shaped protruding protrusions are guided and engaged with the spiral guide. Further, the intermediate rotating body is biased by a mainspring spring toward the side where the rotation is advanced with respect to the housing, and appropriately receives a force on the side of delaying rotation by an electromagnetic brake. In the case of this device, the springs and electromagnetic brakes that apply operating force to the intermediate rotating body, and the assembly angle of the housing (drive rotating body) and lever shaft (driven rotating body) are rotated according to the rotation of the intermediate rotating body. The assembly angle changing means is constituted by the link that is operated and operated.
[0004]
In this device, when the electromagnetic brake is in the OFF state, the intermediate rotating body is positioned at the initial position with respect to the housing under the urging force of the mainspring spring, and the movable guide portion that meshes with the spiral guide with the ridge is provided. Displacement to the outside in the radial direction to the maximum, causing the link to cause the assembly angle of the housing and lever shaft to be the angle position of the most retarded angle phase (hereinafter referred to as the “most retarded angle position”) or the angle position of the most advanced angle phase (Hereinafter referred to as “the most advanced position”). Then, when the electromagnetic brake is turned on from this state, the intermediate rotating body is decelerated and rotates relatively to the delay side with respect to the housing, so that the movable guide portion that meshes with the spiral guide is displaced radially inward, The assembly angle of the housing and the lever shaft is changed to the most advanced position or the most retarded position by gradually tilting the link that has been caused so far.
[0005]
[Patent Literature]
JP-A-2001-41013
[Problems to be solved by the invention]
In the conventional valve timing control device described above, the assembling angle at the start of the internal combustion engine is the most retarded angle position or the most advanced angle position (the most retarded angle position when applied to the valve system on the intake side. The exhaust side. When applied to this valve system, the valve is returned to the most advanced position), thereby reducing the valve overlap between the intake valve and the exhaust valve, thereby stabilizing the combustion at the time of engine start. The assembly angle at the start of the engine is constant regardless of the temperature of the internal combustion engine, and is always constant not only in the cold when the engine starts easily but also in the high temperature where the combustion is relatively stable. It was returned to the assembly corner position.
[0007]
By the way, there are many situations where the internal combustion engine is started in a high temperature state and low speed operation such as idling is performed as it is. In recent years, there is a demand for further improvement in fuel consumption under this situation.
[0008]
In order to further improve fuel economy under these circumstances, it is necessary to increase the valve overlap between the intake and exhaust valves in order to reduce the pumping loss of the engine. However, combustion stability at low temperature start (engine startability) However, such a request cannot be met with an apparatus that places emphasis on.
[0009]
Accordingly, the invention of this application is to provide a valve timing control device for an internal combustion engine that can improve fuel efficiency immediately after starting at high temperatures without deteriorating engine startability at low temperatures.
[0010]
The present invention has been devised in order to solve the technical problem of the prior art. The invention according to claim 1 is, in particular, provided with temperature detection means for detecting the temperature of the internal combustion engine, and is capable of starting the internal combustion engine. The assembling angle of the assembling angle changing means at the time when the detected temperature at the time of starting by the temperature detecting means is lower than a predetermined temperature, than when the detected temperature at the starting time is higher than the predetermined temperature. Also, the valve overlap between the intake valve and the exhaust valve is reduced by controlling to the retard side.
[0011]
In the case of this invention, since the assembly angle at the time of starting is controlled according to the temperature of the internal combustion engine, at the time of low temperature, the valve overlap between the intake valve and the exhaust valve is reduced to realize reliable engine starting, and at the time of high temperature, By increasing the valve overlap, it is possible to reduce the pumping loss and improve the fuel consumption immediately after the engine is started. Further, when the valve overlap is reduced at the time of low temperature start, so-called internal EGR is reduced, so that the combustion temperature rises. As a result, it is possible to suppress the discharge of the inert gas and the catalyst temperature. it is possible to suppress the emissions of the NO _x early rise.
[0013]
Further, when the temperature detected at the time of starting by the temperature detecting means is lower than a predetermined temperature , the engine is started by controlling the detected temperature at the time of starting to the retard side than when the temperature detected at the time of starting is higher than the predetermined temperature. For difficult low-temperature starting, the valve overlap is reduced, so the combustion during starting is stabilized. At high temperature starting, which is relatively easy to start the engine, the valve overlap increases and pumping loss is reduced. Is done.
In addition, if the assembly angle is controlled to the advance side during high-temperature start, the valve overlap increases and the closing timing of the intake valve is accelerated, so the air-fuel mixture becomes the intake side at the beginning of the transition from the intake stroke to the compression stroke. It becomes difficult to escape from. For this reason, an actual compression ratio increases and the low speed torque after a start increases.
The invention according to claim 2 is characterized in that the temperature of the internal combustion engine is detected by the temperature detection means when the engine is started, and the assembly angle changing means is controlled during cranking of the internal combustion engine according to the detected temperature. Yes.
The invention according to claim 3 is characterized in that when the internal combustion engine is stopped, the assembly angle is controlled to a reference assembly angle position at which the internal combustion engine can be started.
The invention described in claim 4 is characterized in that an electromagnetic actuator is used as the actuator of the assembly angle changing means.
In the invention according to claim 5, the assembling angle changing means is provided with respect to a radial guide provided on one of the drive rotator and the driven rotator, and the drive rotator and the driven rotator. An intermediate rotator which is provided so as to be relatively rotatable and has a spiral guide on a surface facing the radial guide; and a movable guide portion which is slidably guided by the radial guide and the spiral guide. A link that connects the movable guide part with a movable part that is separated from the center of rotation of the other of the drive rotator and the driven rotator, and a rotation operation force that rotates the intermediate rotator. And an assembly of the drive rotating body and the driven rotating body by amplifying the rotating operating force input to the intermediate rotating body by the engaging portion of the spiral guide and the movable guide section. It is characterized by converting it into angular operation force.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of the invention of this application will be described with reference to FIGS.
[0015]
In this embodiment, the valve timing control device according to the invention of this application is applied to the valve system on the intake side of the internal combustion engine, but can also be applied to the valve system on the exhaust side.
[0016]
As shown in FIG. 1, the valve timing control device includes a camshaft 1 rotatably supported by a cylinder head (not shown) of an internal combustion engine, and a driven shaft member 7 (coupled to the front end portion of the camshaft 1). A driven rotating body) and a timing sprocket 2 which is assembled to the driven shaft member 7 so as to be rotatable relative to the driven shaft member 7 and linked to a crankshaft (not shown) via a chain (not shown). Is disposed on the front side (left side in FIG. 1) of the drive ring 3 and the driven shaft member 7, and the assembly angle is manipulated by relatively rotating both 3 and 1. The assembling angle changing means 4 and an unillustrated VTC cover that covers the front surface and the peripheral area of the assembling angle changing means 4 that are mounted across the front surface of the cylinder head and the head cover, not shown, of the internal combustion engine. . The assembly angle changing means 4 includes an operating force generating unit 40 that generates a rotating operation force, and the rotating operation force generated by the operating force generating unit 40 relative to the drive ring 3 and the driven shaft member 7. And a conversion mechanism unit 41 that converts it into a rotational force.
[0017]
The drive ring 3 is formed in a substantially disc shape having a step-like insertion hole 6, and the insertion hole 6 portion is rotatably assembled to a driven shaft member 7 (driven rotation body). The front surface of the drive ring 3 (the surface opposite to the camshaft 1) has three radial grooves 8 (radial guides) having parallel side walls facing each other as shown in FIGS. The ring 3 is formed so as to be substantially along the radial direction.
[0018]
Further, as shown in FIG. 1, the driven shaft member 7 has an enlarged diameter portion formed on the outer circumference on the base side that is abutted against the front end portion of the camshaft 1, and an outer circumference on the front side of the enlarged diameter portion. Three levers 9 projecting radially on the surface are integrally formed, and are coupled to the camshaft 1 by bolts 10 penetrating the shaft core portion. The base end of each link 11 is pivotally connected to each lever 9 by a pin 12, and a columnar protrusion 13 slidably engaged with each radial groove 8 is integrally formed at the tip of each link 11. Is formed.
[0019]
Each link 11 is connected to the driven shaft member 7 via the pin 12 in a state where the protruding portion 13 is engaged with the corresponding radial groove 8, so that the distal end side of the link 11 receives an external force and receives the radial groove. When displaced along 8, the drive ring 3 and the driven shaft member 7 are relatively rotated by the action of the link 11 by a direction and an angle corresponding to the displacement of the protrusion 13.
[0020]
In addition, a housing hole 14 that opens to the front side in the axial direction is formed at the tip of each link 11, and an engagement pin 16 that engages with a spiral groove 15 (a spiral guide), which will be described later, in the housing hole 14. A coil spring 17 that urges the engaging pin 16 forward (spiral groove 15 side) is accommodated. In the case of this embodiment, a movable guide portion that is displaceable in the radial direction is configured by the protruding portion 13 at the tip of the link 11, the engaging pin 16, the coil spring 17, and the like.
[0021]
On the other hand, an intermediate rotating body 18 having a disk-like flange wall is rotatably supported via a bearing 19 on the front side of the protruding position of the lever 9 of the driven shaft member 7. The aforementioned spiral groove 15 having a semicircular cross section is formed on the rear surface side of the flange wall of the intermediate rotating body 18, and the engagement pin 16 at the tip of each link 11 is rotatably guided in the spiral groove 15. Is engaged. The spiral of the spiral groove 15 is formed so as to gradually reduce the diameter along the engine rotation direction R. Therefore, when the intermediate rotating body 18 rotates relative to the drive ring 3 in the delay direction in a state where the engaging pin 16 at the tip of each link 11 is engaged with the spiral groove 15, the tip of the link 11 is in the radial groove 8. , Guided to the spiral shape of the spiral groove 15 and moved radially inward, and conversely, when the intermediate rotating body 18 is relatively displaced in the advance direction, it moves radially outward.
[0022]
The conversion mechanism 41 of the assembly angle changing means 4 is constituted by the radial groove 8, the link 11, the protrusion 13, the engagement pin 16, the lever 9, the intermediate rotating body 18, the spiral groove 15, etc. of the drive ring 3 described above. It is configured. When the relative rotation operation force with respect to the camshaft 1 is input to the intermediate rotating body 18 from the operation force generation unit 40 described later, the conversion mechanism unit 41 receives the operation force between the spiral groove 15 and the engagement pin 16. The distal end of the link 11 is displaced in the radial direction through the engaging portion. At this time, the link 11 swings and the drive ring 3 and the driven shaft member 7 are relatively rotated according to the swing amount.
[0023]
On the other hand, the operating force generator 40 includes a spring spring 45 as an urging means for urging the intermediate rotator 18 in the engine rotation direction R with respect to the drive ring 3, and the intermediate rotator 18 with respect to the drive ring 3. A hysteresis brake 20 as an electromagnetic actuator that operates in a direction opposite to the rotation direction R (generates a force against the biasing means), and balances the biasing force of the mainspring spring 45 and the actuation force of the hysteresis brake 20 The intermediate rotating body 18 is rotated.
[0024]
The mainspring spring 45 has an outer peripheral end coupled to the cylindrical wall 21 extending to the drive ring 3, and an inner peripheral end coupled to the cylindrical base of the intermediate rotating body 18.
[0025]
A sealing wall 46 is integrally coupled to the end surface of the intermediate rotating body 18 opposite to the camshaft 1, and the outer peripheral surface of the sealing wall 46 is slidably in close contact with the inner surface of the cylindrical wall 21. ing.
[0026]
As shown in FIGS. 1 and 4, the hysteresis brake 20 is attached to a VTC cover which is a non-rotating member, and provided with a magnetic induction member 22 having an opposing surface sandwiching a substantially cylindrical gap, and provided on the opposing surface. The inner pole teeth 23 and the outer pole teeth 24, the electromagnetic coil 25 attached to the magnetic induction member 22 to generate a magnetic field between the inner pole teeth 23 and the outer pole teeth 24, and the bipolar teeth 23 and 24. A cylindrical hysteresis ring 26 inserted in a non-contact state therebetween, and an outer peripheral end integrally coupled to the hysteresis ring 26 are coupled to the intermediate rotating body 18 via a coupling pin 47 and a rubber bush 48. The electromagnetic coil 25 is appropriately energized and controlled by the output signal of the controller 42.
[0027]
Each of the inner pole teeth 23 and the outer pole teeth 24 of the magnetic induction member 22 has a plurality of pole teeth elements extending along the axial direction. The pole tooth elements of the both pole teeth 23, 24 are arranged along the circumferential direction, and the pole tooth elements of the pole teeth 23, 24 are offset in the circumferential direction. Therefore, when the electromagnetic coil 25 is energized, a magnetic field is generated between the pole teeth 23 and 24 toward the counterpart pole tooth element having an offset positional relationship.
[0028]
The hysteresis ring 26 is made of a hysteresis material having magnetic hysteresis characteristics. When a magnetic field is generated between the inner pole teeth 23 and the outer pole teeth 24 during the rotation of the ring 26, the direction of the magnetic field and the hysteresis ring 26. Deviation occurs in the direction of the magnetic flux. The hysteresis brake 20 generates a braking force due to this deviation. The annular plate 27 is integrally coupled to a shaft member 30 supported on the inner peripheral surface of the magnetic induction member 22 via bearings 28 and 29. Therefore, the hysteresis ring 20 is supported by the magnetic induction member 22 via the annular plate 27 and the shaft member 30 so as to be relatively rotatable.
[0029]
In the figure, reference numeral 43 denotes a stopper provided between the intermediate rotator 18 and the drive ring 3 to restrict the relative rotation range of both the members 18 and 3.
[0030]
The controller 42 receives signals for determining the operating state of the engine from the crank angle sensor 35, the cam angle sensor 36, and the like, and the controller 42 feedback-controls the energization current of the hysteresis brake 20 based on these signals. It is like that. Further, a signal from an oil temperature sensor 37 (temperature detecting means in this application) for detecting the oil temperature of the lubricating oil is further input to the controller 42, and the assembly angle at the time of engine start is appropriately controlled by the controller 42. It is like that.
[0031]
In the case of this embodiment, the assembly angle position at the time of engine start is controlled to one of θ ₁ to θ ₃ shown in FIGS. 5 and 6 according to the temperature of the internal combustion engine detected by the oil temperature sensor 37. It is like that. Here, θ ₁ is an angular position approximately halfway between the most retarded angle position and the most advanced angle position, θ ₂ is an angle position that is deviated from θ ₁ on the retard angle side, and θ ₃ is , Θ ₁ is an angular position that is deviated by a set angle toward the advance side. The assembly angles θ _{1 to} θ ₃ at the time of starting the engine can be switched with two threshold temperatures T ₁ and T ₂ (where T ₁ <T ₂ ) as shown in FIG. It has become.
[0032]
Since this valve timing control device is configured as described above, when the rotational phase of the crankshaft and the camshaft 1 (the opening / closing timing of the engine valve) is changed to the most advanced angle side, a predetermined current is supplied to the hysteresis brake 20. Is applied to the intermediate rotating body 18 from the annular plate 27 through the connecting pin 47 and the rubber bush 48. As a result, the intermediate rotating body 18 rotates in the opposite direction with respect to the drive ring 3, whereby the engaging pin 16 at the tip of the link 11 is guided to the spiral groove 15, and the tip of the link 11 is displaced radially inward. At this time, as shown in FIG. 3, the assembly angle of the drive ring 3 and the driven shaft member 7 is changed to the most advanced position by the action of the link 11.
[0033]
Further, when the rotational phase of the crankshaft and the camshaft 1 (opening / closing timing of the engine valve) is changed to the most retarded angle side, the intermediate rotating body 18 is turned to the spring spring 45 by turning off the power supply to the hysteresis brake 20. It is rotated in the direction of engine rotation by the force of. Then, the leading end portion of the link 11 is displaced radially outward by the guide of the engaging pin 16 by the spiral groove 15, and at this time, the combination of the drive ring 3 and the driven shaft member 7 by the action of the link 11 as shown in FIG. The angle is changed to the most retarded position.
[0034]
When the rotational phase of the crankshaft and the camshaft 1 is changed to an arbitrary position between the most advanced angle position and the most retarded angle position, the current value supplied to the hysteresis brake 20 is appropriately controlled to drive The relative rotational position of the intermediate rotating body 18 with respect to the ring 3 is adjusted by the balance between the mainspring spring 45 and the hysteresis brake 20.
[0035]
Further, when the internal combustion engine is started, the assembly angle is controlled to any one of θ ₁ to θ ₃ as described above. Specific control at this time is executed according to the flowchart shown in FIG.
[0036]
That is, first, when the ignition key is turned on in S1, the temperature of the internal combustion engine is detected by the oil temperature sensor 37 in S2, and then, in S3, the detected temperature T is set to the lower threshold. whether a temperature above T ₁ is determined. In this case, the detected temperature T is controls the theta assembling angle position at engine starting to theta ₂ advances to step S4 is lower than the temperature T ₁ of, when the detected temperature T is a temperature above T ₁ is S5 Proceed to In S5, further the detected temperature T is determined whether lower than the upper threshold temperature T _2, and controls the theta assembling angle position proceeds to step S6 in the case of temperature T ₂ above theta _3, the temperature T When it is lower than ₂ , the routine proceeds to S7, where the assembly angular position θ is controlled to θ ₁ .
[0037]
Therefore, in this valve timing control device, when the temperature T of the internal combustion engine is a low temperature where T <T ₁ , the initial position θ at the start of the engine is controlled to the retarded angle position θ _2. Therefore, at the time of cold start, as shown in FIG. 5, the valve overlap between the intake valve and the exhaust valve becomes small, so that the engine combustion at the start and idling is stabilized and the so-called internal EGR is reduced, so that the combustion temperature is reduced. As a result, the inert gas suppression effect and the HC suppression effect due to the early temperature rise of the catalyst can be obtained.
[0038]
Further, when the temperature T of the internal combustion engine is high such that T ₂ ≦ T, the initial position θ at the time of starting the engine is controlled to the retarded angle position θ ₂ , so at the time of high temperature starting, FIG. As shown in FIG. 4, the valve overlap between the intake valve and the exhaust valve is increased, and as a result, the pumping loss immediately after the engine is started is reduced, and the fuel efficiency of the engine is improved. Further, when the initial position θ is controlled to θ ₂ , the closing timing of the intake valve is advanced, so that the actual compression ratio is increased and the low speed torque after the engine is started is improved.
[0039]
Further, at the normal temperature where the temperature T of the internal combustion engine satisfies T ₁ ≦ T <T ₂ , the valve overlap magnitude and the intake valve closing timing are almost in the middle of the above two conditions, and combustion stability, Characteristics such as fuel consumption and low-speed torque are also almost intermediate.
[0040]
Further, in this apparatus, at a low temperature as described above, at high temperatures, but assembling angle at engine starting in the condition of normal temperature is switched, the assembling angle position theta ₂ of the retarded side during cold start When the engine is switched, the assembly angle can be quickly switched to the most retarded position after the engine is started as shown in FIG. 5, and similarly, the engine is switched to the advanced assembly angle position θ ₃ at the high temperature start. Sometimes the assembly angle can be quickly switched to the most advanced angle after the engine is started. Therefore, in the apparatus of this embodiment, there is an advantage that it is possible to quickly switch to a desired assembly angle corresponding to the engine temperature after the engine is started.
[0041]
By the way, in the valve timing control device of this embodiment, when the internal combustion engine is started, the assembly angle is controlled in accordance with the engine temperature. However, separately from this, the ignition key is turned off from the engine operating state. Then, before the engine is completely stopped, the assembly angle θ may be returned to the reference assembly angle position at the time of starting the engine (assembly angle position at normal temperature) θ ₁ .
[0042]
In this case, the assembly angle immediately before starting the engine is the intermediate assembly angle position θ ₁ between θ ₂ and θ ₃ , so the assembly angle at the start determined by the detected temperature is θ ₁ to θ _In any of the cases, it can be quickly changed to a predetermined assembly angle position.
[0043]
The embodiment of the present invention is not limited to the above-described embodiment. For example, in the above embodiment, the operating force generating portion of the assembly angle changing means is configured by a spring and a hysteresis brake. The force generation unit may be configured by an urging unit and an electromagnetic actuator other than these. Further, the operating force generator does not necessarily need to use an urging means, and the urging means can be eliminated if an electromagnetic actuator capable of forward / reverse rotation is used. Furthermore, a hydraulic actuator may be used as the actuator of the assembly angle changing means.
[0044]
Further, the temperature detecting means for detecting the temperature of the internal combustion engine is not limited to the oil temperature sensor 37 but may be a water temperature sensor for detecting the cooling water temperature or the like.
[0045]
As described above, the valve timing control device according to the invention of this application can also be applied to the valve system on the exhaust side. In this case, the assembly angle at the low temperature start is set to the same as that at the high temperature start. What is necessary is just to change to an advance side rather than an assembly angle.
[0046]
Next, inventions other than those described in the claims that can be grasped from each of the above embodiments will be described below together with the effects thereof.
[0047]
(A) The temperature of the internal combustion engine is detected by the temperature detection means when the engine is started, and the assembly angle changing means is controlled during cranking of the internal combustion engine according to the detected temperature. A valve timing control device for an internal combustion engine according to claim 1.
[0048]
In this case, the assembly angle control according to the temperature of the internal combustion engine at the time of starting the engine can be accurately performed.
[0049]
(B) When the internal combustion engine is stopped, the assembly angle is controlled to a reference assembly angle position at which the internal combustion engine can be started. Timing control device.
[0050]
In this case, the assembly angle is returned to the reference assembly angle position where the internal combustion engine can be started in advance when the engine is stopped, so that the internal assembly engine can be quickly changed to an appropriate assembly angle according to the engine temperature. Is possible.
[0051]
(C) The valve timing control device for an internal combustion engine according to any one of claims 1 and 2, and (a) and (b), wherein an electromagnetic actuator is used as the actuator of the assembly angle changing means.
[0052]
In this case, since the electromagnetic actuator is used, a large starting torque can be obtained immediately upon energization when the engine is started. Therefore, when starting the internal combustion engine, the assembly angle changing means can be quickly operated to the assembly angle position corresponding to the engine temperature.
[0053]
(D) Assembling angle changing means:
A radial guide provided on one of the drive rotor and the driven rotor,
An intermediate rotator which is provided so as to be relatively rotatable with respect to the drive rotator and the driven rotator, and which has a spiral guide on a surface facing the radial guide;
A movable guide unit that is movably guided and engaged with the radial guide and the spiral guide;
A link that oscillates and couples the movable guide portion with a portion spaced from the rotation center of the other of the drive rotator and the driven rotator,
An operation force generating unit that generates a rotation operation force for rotating the intermediate rotating body, and the rotation operation force input to the intermediate rotating body is amplified by the engaging portion of the spiral guide and the movable guide unit. The valve timing control device for an internal combustion engine according to any one of claims 1, 2, and (a) to (c), wherein the valve timing control device is converted into an assembly angle operating force of the driving rotating body and the driven rotating body. .
[0054]
In this case, since the force generated by the operating force generator is amplified and converted into an assembly angle operating force of the drive rotator and the driven rotator, the assembly angle can be obtained even at the initial stage of engine start, which requires a large operating force. Can be quickly changed to an angular position corresponding to the engine temperature.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing an embodiment of the invention of this application.
2 is a cross-sectional view taken along the line AA of FIG. 1 showing the embodiment.
3 is a cross-sectional view corresponding to FIG. 2 showing an operating state of the embodiment.
FIG. 4 is an exploded perspective view showing the embodiment.
FIG. 5 is a view showing valve lift characteristics of the embodiment.
FIG. 6 is a view showing the relationship between the temperature and the assembly angle according to the embodiment.
FIG. 7 is a flowchart showing control of the embodiment.
[Explanation of symbols]
1 ... Camshaft 3 ... Drive ring (drive rotor)
4 ... Assembly angle changing means 7 ... Driven shaft member (driven rotor)
37. Oil temperature sensor (temperature detection means)

Claims (5)

A drive rotator that is rotationally driven by a crankshaft of the internal combustion engine;
A driven rotary body composed of a camshaft on the intake side or a separate member coupled to the same shaft, and assembled so that the drive rotary body can be relatively rotated as required;
In a valve timing control device for an internal combustion engine, comprising: an assembly angle changing means for operating an assembly angle of the drive rotor and the driven rotor.
Temperature detection means for detecting the temperature of the internal combustion engine is provided, and the assembly angle of the assembly angle changing means at the start of the internal combustion engine is set so that the temperature detected at the start by the temperature detection means is lower than a predetermined temperature. The valve timing control of the internal combustion engine is characterized in that the valve overlap between the intake valve and the exhaust valve is reduced by controlling the detected temperature at the time of starting to a retard side than when the detected temperature is higher than the predetermined temperature. apparatus.   2. The internal combustion engine according to claim 1, wherein the temperature of the internal combustion engine is detected by the temperature detection means when the engine is started, and the assembly angle changing means is controlled during cranking of the internal combustion engine according to the detected temperature. Valve timing control device.   The valve timing control device for an internal combustion engine according to claim 1 or 2, wherein when the internal combustion engine is stopped, the assembly angle is controlled to a reference assembly angle position at which the internal combustion engine can be started.   The valve timing control device for an internal combustion engine according to any one of claims 1 to 3, wherein an electromagnetic actuator is used as the actuator of the assembly angle changing means. The assembly angle changing means is
A radial guide provided on one of the drive rotator and the driven rotator,
An intermediate rotator which is provided so as to be rotatable relative to the drive rotator and the driven rotator, and which has a spiral guide on a surface facing the radial guide;
A movable guide unit that is movably guided and engaged with the radial guide and the spiral guide;
A link that oscillates the movable guide part and a portion spaced from the rotation center of the other of the drive rotator and the driven rotator,
An operation force generator that generates a rotation operation force for rotating the intermediate rotating body,
The rotating operation force input to the intermediate rotating body is amplified by the engaging portion of the spiral guide and the movable guide portion, and converted into an assembly angle operating force of the driving rotating body and the driven rotating body. The valve timing control device for an internal combustion engine according to any one of claims 1 to 4.

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