JP4531674B2 - Valve timing control device for internal combustion engine - Google Patents

Description

  The present invention relates to a valve timing control device that makes opening / closing timings of intake valves and exhaust valves of an internal combustion engine variable in accordance with operating conditions.

  As a conventional valve timing control device, a vane type device described in Patent Document 1 below is known.

  Briefly, this valve timing control device is applied to the intake side, and the end portion of the camshaft is placed inside the cylindrical housing of the timing sprocket whose front and rear opening ends are closed by the front cover and the rear cover. A vane fixed to the housing is rotatably housed, and two substantially trapezoidal shoes and two vanes (blade portions) of the vane member projecting inward from the diametrical direction to the inner peripheral surface of the housing. An advance angle chamber and a retard angle chamber are separated between each other.

  Then, the electronic controller controls the operation of the flow path switching valve (OCV) according to the engine operating state, thereby switching the flow paths and supplying the hydraulic pressure discharged from the oil pump to the advance chamber and the retard chamber. By selectively supplying and discharging to each chamber and rotating the vane member forward and backward, the relative rotation phase of the timing pulley and camshaft is changed to the advance or retard side, and the opening and closing timing of the intake valve is variable. It comes to control.

In addition, a hydraulic pressure sensor is provided between the oil pump and the flow path switching valve, and when the hydraulic pressure discharged from the oil pump is lower than a predetermined pressure, based on an information signal from the hydraulic pressure sensor that has detected it. The electronic controller shuts off the oil passages by the flow path switching valve and stops the supply of hydraulic pressure to the advance chamber and the retard chamber. As a result, the abnormal operation of the valve timing control device is suppressed.
JP-A-11-141359

  In the conventional valve timing control device, as described above, when the engine is started, the oil pressure discharged from the oil pump is reduced to a predetermined value or less, so that the hydraulic pressure is supplied to the advance chamber and the retard chamber. The valve timing control device is stopped to prevent abnormal operation. However, when the engine is stopped for a long time, most of the hydraulic fluid from the hydraulic chambers in both the advance chamber and the retard chamber is externally As a result, air stays in each chamber.

  For this reason, if the lock pin that fixes the movement of the vane member is removed at the initial stage of the engine start, the vane member compresses the air in the advance chamber and the retard chamber by the positive and negative alternating torque generated in the camshaft. However, there is a risk of flapping in the forward / reverse rotation direction. Accordingly, there is a possibility that the device will be abnormally operated due to the positive and negative alternating torque acting on the vane member from the camshaft and abnormal noise will be generated.

  Also, even when the lock pin is functioning normally, the retained air is compressed by the hydraulic pressure, the hydraulic pressure apparently rises temporarily by the compression pressure of this compressed air, and then the compressed air is released, A phenomenon occurs in which the hydraulic pressure increased by compressed air decreases. After this, if the normal oil pressure from the working oil is applied to increase the oil pressure and the hydraulic pressure conditions are sufficient to drive the phase changing mechanism, the phase changing mechanism can be operated. However, if the phase change mechanism is driven by the increase in hydraulic pressure due to the previous compressed air, the air is compressed by the vane member, and abnormal operation and noise occur.

The present invention has been devised in view of the technical problems of the conventional valve timing control device, and the invention according to claim 1 selectively supplies and discharges hydraulic pressure to and from the advance chamber and the retard chamber. A phase change mechanism that changes the relative rotation phase of the camshaft with respect to the crankshaft, a hydraulic control valve that controls the hydraulic pressure supplied to and discharged from the advance chamber or retard chamber, and the advance chamber or A hydraulic pressure detection means for detecting a hydraulic pressure between the phase change mechanism supplied to the retard chamber and the hydraulic pressure control valve ; an ignition key is turned on; And a control means for starting control of the hydraulic control valve according to the engine operating state after a predetermined time has elapsed after detection.

According to the invention, the cranking is started, in terms of the advance chamber or either one of the supplied oil pressure in the retard chamber exceeds a predetermined, after a predetermined time has elapsed, by the control means since the position phase changing mechanism controls the hydraulic pressure control valve operably, it is possible to obtain a stable operation of the phase changing mechanism.

  Hereinafter, embodiments of a valve timing control device (VTC) for an internal combustion engine according to the present invention will be described in detail with reference to the drawings. This embodiment also shows the one applied to the intake valve side as in the prior art.

  1 to 5 show a first embodiment of the present invention, in which a timing sprocket 1 that is a driving member that is rotationally driven via a timing chain by a crankshaft outside the engine, and the timing sprocket 1. A camshaft 2 provided so as to be relatively rotatable, a vane member 3 which is a driven member fixed to an end of the camshaft 2 and rotatably accommodated in the timing sprocket 1, and the vane member 3 is hydraulically And a hydraulic circuit 4 that rotates forward and backward.

  The timing sprocket 1 is integrally provided with a tooth portion 5a meshing with a timing chain on the outer periphery, and a housing 5 that rotatably accommodates the vane member 3 and a circle that is a lid that closes the front end opening of the housing 5. A plate-shaped front cover 6 and a substantially disk-shaped rear cover 7 that closes the rear end opening of the housing 5 are configured. The housing 5, the front cover 6, and the rear cover 7 are camshafts by four small-diameter bolts 8. It is fixed together by fastening from the axial direction.

  The housing 5 has a cylindrical shape in which both front and rear ends are formed, and partition walls 10 that are four shoes project inwardly at a position of about 90 ° in the circumferential direction of the inner peripheral surface. Each of the partition walls 10 has a substantially trapezoidal cross section and is provided along the axial direction of the housing 5. Both end edges in the axial direction are flush with the both end edges of the housing 5. Four bolt insertion holes 11 through which the bolts 8 are inserted are formed in the center position so as to penetrate in the axial direction. Further, each partition wall 10 has an inner end surface formed in an arc shape along the outer shape of a vane rotor (to be described later) of the vane member 3 and a notch formed along the axial direction at the position of the upper portion of the inner end surface. A U-shaped seal member 12 and a leaf spring (not shown) that presses the seal member 12 inward are fitted and held in the groove 11.

  The front cover 6 has a relatively large-diameter bolt insertion hole 6a formed in the center, and four bolt holes that are inserted into the bolt insertion holes 8 of the housing 5 in the outer peripheral portion. .

  The rear cover 7 is formed with a bearing hole 7a that rotatably supports the front end 2a of the camshaft 2 at the center, and four female screw holes into which the small-diameter bolts 8 are screwed. Has been.

  The camshaft 2 is rotatably supported at the upper end of the cylinder head via a cam bearing (not shown), and a cam for opening an intake valve (not shown) via a valve lifter is integrally formed at a predetermined position on the outer peripheral surface. Is provided.

  The vane member 3 is integrally formed of a sintered alloy material, and an annular vane rotor 14 fixed to the front end portion of the camshaft 2 by a cam bolt 13 at the center, and a circumferential direction 90 ° of the outer peripheral surface of the vane rotor 14. And four vanes 15 provided integrally at the position. The vane rotor 14 is inserted with the cam bolt 16 in the central axis direction, and is formed with a through hole 13a having a step-diameter shape through which the front end portion 2a of the camshaft 2 is inserted and fitted. It is fixed to the front end 2a from the axial direction.

  Three of the four vanes 15 each have an elongated rectangular shape, and one is formed in a substantially trapezoidal shape having a large circumferential width, whereby the weight balance of the entire vane member 3 is achieved. Yes. Each vane 15 is disposed between the partition walls 10, and a holding groove is formed in the center of each outer peripheral surface. The vane 15 is in sliding contact with the inner peripheral surface of the housing 5 in each holding groove. A U-shaped seal member 16 and a leaf spring 16a that presses the seal member 16 toward the inner peripheral surface of the housing 5 are fitted and held.

  Further, four advance chambers 17 and retard chambers 18 are respectively defined between both sides of each vane 15 and both side surfaces of each partition wall 10.

  As shown in FIGS. 1, 2, and 7, the hydraulic circuit 4 includes a first oil passage 19 that supplies and discharges working hydraulic pressure that is lubricating oil to each advance chamber 17, and each retard chamber. There are two systems of oil passages, a second oil passage 20 for supplying and discharging operating hydraulic pressure to and from these two oil passages 19 and 20, a supply passage 21 which is a main oil gallery for supplying engine lubricating oil. And a drain passage 22 are connected to each other via a passage-switching hydraulic control valve 23. The supply passage 21 is provided with a one-way oil pump 25 for pumping oil in the oil pan 24, while the downstream end of the drain passage 22 communicates with the oil pan 24.

  As shown in FIGS. 2 and 4, the first oil passage 19 is formed between the hydraulic control valve 23 and each advance chamber 17, and from the cylinder head to the cam bearing and the camshaft 2. The first passage portion 19a formed in the inner axial direction of the camshaft 2 and the groove groove on the front end side of the camshaft 2 are branched radially into the vane rotor 14 to form the first passage portion 19a and each advance chamber 17. The four branch paths 19b communicate with each other.

  On the other hand, the second oil passage 20 is formed between the hydraulic control valve 23 and each retard chamber 18, and is a second passage formed from the inside of the cylinder head toward the internal axis of the cam bearing and the camshaft 2. Four second branch passages 20b that are radially branched from the radial hole of the cam portion 20a and the camshaft front end portion 2a into the vane rotor 14 and communicate with the second passage portion 20a and each retarded angle chamber 18. It consists of and.

  The second oil passage 20 is provided with a dedicated hydraulic switch 26 which is a hydraulic pressure detecting means for detecting the hydraulic pressure that has passed through the hydraulic control valve 23. That is, the hydraulic switch 26 detects the pressure of the hydraulic pressure that is discharged from the oil pump 25 at the time of engine start, etc., passes through the supply passage 21 and the hydraulic control valve 23, and receives flow resistance. Yes. Further, the hydraulic pressure above a predetermined level detected by the hydraulic switch 26 is based on the pressure at which the air staying in each retarded angle chamber 18 when the engine is stopped is compressed by the hydraulic oil discharged from the oil pump 25 when the engine is started. Is also slightly larger.

  The vane member 3 and the housing 5 and the advance angle and retard angle chambers 17 and 18 constitute a phase change mechanism.

  As shown in FIGS. 1 and 2, the hydraulic control valve 23 is a four-port two-position solenoid valve, and has a bottomed cylindrical valve body fixed in a valve hole formed in the cylinder head. 27, a solenoid 28 integrally fixed to the outer end of the valve body 27, and a spool valve body 29 slidably provided inside the valve body 27.

  The valve body 27 has a supply port 30 communicating with the supply passage 21 and the inside of the valve body 27 at a substantially central position in the axial direction, and the first oil is provided on both sides of the supply port 30 in the axial direction. First and second ports 31 and 32 communicating with the end portions of the passage 19 and the second oil passage 20 and the inside of the valve body 27 are formed along the radial direction. Further, first and second drain ports 33 and 34 communicating with the inside of the valve body 27 and the drain passage 22 are formed on the outer sides of the first and second ports 31 and 32, respectively.

  The supply port 30 and the first and second ports 31 and 32 are substantially the same in cross-sectional area as the supply passage 21 and the first and second oil passages 19 and 20 to which the respective passage cross-sectional areas are connected. They are set the same.

  The solenoid 28 is slid by an electromagnetic coil 28b provided in a solenoid casing 28a, a fixed core 28c excited by energization of the electromagnetic coil 28b, and excitation of the fixed core 28c, and the spool valve body. It is mainly composed of a movable plunger 28d for pressing and moving 29. The electromagnetic coil 28b is energized or interrupted by a control current from the electronic controller 36 via a harness not shown.

  The spool valve body 29 is provided at a substantially central first land portion 29a that opens and closes the supply port 30 according to an axial sliding position, and on both axial sides of the first land portion 29a. The first and second ports 31 and 32 and the drain ports 33 and 34 are provided with second and third land portions 29b and 29c that open and close relative to each other. Further, the spool valve element 29 has a spring force of a return spring 35 elastically mounted between a flange-shaped spring retainer 29d provided at one end and an annular retainer integrally provided on the inner periphery of the valve body 27. 1 is urged to the maximum right direction, that is, the position where the supply port 30 and the second port 32 communicate with each other and the first port 31 and the drain port 33 communicate with each other, as shown in FIG. By the control current from the electronic controller 36, the movement is controlled to the maximum left direction or a predetermined intermediate position against the spring force of the return spring 35.

  The electronic controller 36 includes various sensors such as a crank angle sensor (not shown) that detects the engine speed, a signal from an air flow meter that detects the intake air amount, a throttle valve opening sensor, and a water temperature sensor that detects the engine water temperature. Thus, the current operating state is detected, and the hydraulic control valve 23 is switched and controlled based on the information signal input from the hydraulic switch 26.

  Further, the electronic controller 36 does not energize the electromagnetic coil 28b until the input of the information signal that the hydraulic pressure has become equal to or higher than the predetermined value by the hydraulic switch 26 from the beginning of the engine start when the ignition key is turned on. 29 is held at the maximum rightward position by the spring force of the return spring 35, and when the hydraulic pressure exceeds a predetermined value, the spool valve element 29 is controlled to move and the normal of the phase change mechanism. Control is to be performed.

  Further, a restraining mechanism 37 for restraining the rotation of the vane member 3 relative to the housing 5 or releasing the restraint is provided between the vane 15 having the maximum width and the housing 5.

  As shown in FIGS. 2 and 5, the restraining mechanism 37 is provided between one vane 15 having a large width and the rear cover 8, and extends along the camshaft 2 axial direction inside the vane 15. A formed sliding hole 38, a covered cylindrical lock pin 39 slidably provided in the sliding hole 38, and a cross-sectional cup fixed in a fixing hole formed in the rear cover 8 And is held by a spring retainer 41 fixed to the bottom surface side of the sliding hole 38. The engaging hole 40a is formed in the engagement hole constituting portion 40 and engages and disengages the tapered tip 39a of the lock pin 39. The spring member 42 urges the lock pin 39 in the direction of the engagement hole 40a.

  The lock pin 39 is engaged with the engagement hole 40a by the spring force of the spring member 42 at the position where the vane member 3 is rotated to the most retarded angle side, and the timing sprocket 1 and the camshaft 2 are engaged. The relative rotation is locked. On the other hand, the hydraulic pressure in the advance chamber 17 and the retard chamber 18 is supplied through the oil holes 43a and 43b between the engagement hole 40a, the stepped portion of the lock pin 39, and the sliding hole 38. As a result of this hydraulic pressure, the lock pin 39 moves backward as shown in FIG. 5 so that the engagement with the engagement hole 40a is released.

  The spring member 42 functions as a restraint maintaining mechanism, and the air staying in each retarded angle chamber 18 when the engine is started is greatly compressed by the pressure compressed by the operating oil pressure fed from the oil pump 25 and does not compress and deform. The spring force is set to a degree.

  Hereinafter, the operation of the present embodiment based on the electronic controller 36 will be described.

  First, when the engine is stopped, the supply of hydraulic pressure to the advance and retard chambers 17 and 18 is stopped by stopping the operation of the oil pump 25, and the vane is generated by the alternating torque generated in the camshaft 2 immediately after the engine is stopped. As shown in FIG. 3, the member 3 rotates to the opposite side to the rotation direction (arrow direction) of the camshaft 2 and is positioned on the most retarded angle side.

  At this time, the lock pin 39 of the restraining mechanism 37 is engaged with the front end 39a in the engagement hole 40a by the spring force of the return spring 42 to restrict the free rotation of the vane member 3.

  Further, since the power supply from the electronic controller 36 to the hydraulic control valve 23 is also cut off, the spool valve element 29 is urged to the maximum rightward position as shown in FIG.

Next, when to start the engine the ignition key was turned on, this initial start time, the control current from the electronic controller 36 does not output to the electromagnetic coil 28b. Accordingly, as shown in FIG. 1, the spool valve body 29 is biased to the maximum right direction by the spring force of the return spring 35, so that the first land portion 29 a opens the supply port 30. At the same time, the third land portion 29 c closes the second drain port 34 while opening the second port 32. At the same time, the second land portion 29 b allows the first port 31 and the first drain port 33 to communicate with each other.

  Accordingly, the hydraulic pressure discharged from the oil pump 25 flows into the valve body 27 from the supply passage 21 via the supply port 30, and then flows into the second oil passage 20 from the second port 32, and from there. It is supplied to each retardation chamber 18 through the second branch path 20b. For this reason, the state where the vane member 3 is positioned on the most retarded angle side is maintained by the low hydraulic pressure supplied into each retarded angle chamber 18. As a result, the engine startability is improved.

  At this time, the air staying in each retard chamber 18 is pressed by the low hydraulic pressure and works to press the vane member 3 toward the most retarded angle together with the low hydraulic pressure.

  On the other hand, the lock pin 39 is in a state where the engagement with the engagement hole 40 a is maintained by the spring force of the spring member 42 because the internal pressure in the retard chamber 18 has not yet sufficiently increased. For this reason, it is possible to suppress the occurrence of flapping in the forward and reverse rotation directions due to the alternating torque acting on the camshaft 2.

  Thereafter, when the discharge pressure of the oil pump 25 increases and becomes equal to or higher than a predetermined pressure, the electronic controller 36 performs normal control on the phase conversion mechanism based on the ON signal from the hydraulic switch 26 that detects this.

  That is, immediately after the start, for example, when the hydraulic pressure rises and the hydraulic switch 26 is turned on in about 2 seconds immediately after the ignition key is turned on and cranking is started, the electronic controller 36 turns on the hydraulic control valve 23. The electromagnetic coil 23b is energized to excite the fixed core 28c. Then, the spool valve body 29 gradually moves leftward from the position shown in FIG. 1 via the movable plunger 28d, thereby blocking communication between the first port 31 and the first drain port 33, and the supply port 30. The first port 31 is communicated. At the same time, the second port 32 and the second drain port 34 are communicated. Note that the above-mentioned about 2 seconds is an example, and the rise time of the hydraulic pressure differs depending on the model.

  For this reason, the discharge pressure of the oil pump 25 is supplied to each advance chamber 17 from each branch passage 19b through the first oil passage 19 and the internal pressure becomes high, while the hydraulic oil in each retard chamber 18 is The pressure is returned to the oil pan 24 from the second drain port 22 through the second oil passage 20 and the like.

  As a result, as the hydraulic pressure of each advance chamber 17 increases, the lock pin 39 comes out of the engagement hole 40a as shown in FIG. 5 to release the locked state of the vane member 3, and the vane member 3 At the same time as allowing free rotation, the vane member 3 rotates from the position shown in FIG. 3 to the left in the drawing, that is, in the same direction as the rotation direction of the camshaft 2. Immediately change the relative rotation phase to the advance side.

  As a result, the valve overlap between the intake valve and the exhaust valve is slightly increased, and the HC emission amount can be reduced by the effect of the internal EGR.

  Further, when the engine shifts from the low rotation to the middle rotation range of the steady operation, the energization from the electronic controller 36 to the electromagnetic coil 23 b is maintained, and the hydraulic pressure is continuously supplied to each advance chamber 17. Therefore, the vane member 3 further rotates in the same direction and is held at the maximum rotation position as shown in FIG. 4, and changes the relative rotation phase between the crankshaft and the camshaft 2 to the most advanced angle side. This increases the valve overlap and improves the engine output.

  The spool valve element 29 is held in a neutral position as shown in FIG. 7 by controlling the energization of the hydraulic control valve 23 from the electronic controller 36, and the supply port 30 and the first and second ports 31, 32 The communication between the first and second ports 31 and 32 and the drain ports 33 and 34 can be blocked to hold the vane member 3 at an arbitrary rotational position.

  The on-operation time of the hydraulic switch 26 is slightly different depending on the normal engine stop time, although it depends on the viscosity of the hydraulic oil when the engine is started.

  In the present embodiment, as described above, by changing the opening / closing timing of the intake valve according to the operating state of the engine, it is possible to sufficiently bring out the engine performance, in particular, at the initial start of the engine, Since the electronic controller 36 does not energize the hydraulic control valve 23, the hydraulic pressure is forcibly supplied to each retard chamber 18 even if the hydraulic pressure supplied to each retard chamber 18 is low. Without being influenced by torque, the crankshaft and the camshaft 2 can maintain the relative rotational phase toward the retarding side suitable for starting.

  Further, when the supplied hydraulic pressure exceeds a predetermined value, the hydraulic control valve 23 is controlled so that the phase change mechanism can be operated immediately by the electronic controller 36 via the hydraulic switch 26, so that the engine is started from an early point of time. It becomes possible to perform relative rotation phase control between the crankshaft and the camshaft 2.

  Further, at the initial stage of engine start, the lock pin 39 of the restraining mechanism 37 can prevent inadvertent release from the engagement hole 40a due to air pressure or the like by the relatively large spring force of the spring member 42. become. Therefore, it is possible to eliminate the problem that the device operates abnormally due to inadvertent release by the air pressure or the like and abnormal noise is generated.

  In the present embodiment, since the hydraulic switch 26 detects the hydraulic pressure between the hydraulic control valve 23 and each retard chamber 18, the hydraulic pressure that can control the phase change mechanism can be detected accurately and promptly. Therefore, it is possible to prevent a decrease in the control accuracy of the VTC.

  Further, in this embodiment, as described above, since the electronic controller 36 is immediately driven by the ON operation of the hydraulic switch 26 immediately after the engine is started and the phase conversion mechanism is quickly operated, this is particularly likely to occur at the time of cold start. It becomes possible to effectively suppress the discharge amount of hydrocarbon (HC) in the exhaust gas.

  That is, the upper waveform diagram in FIG. 8 shows the relationship between the elapsed time (sec) at the time of starting the engine and the HC emission amount, the broken line is the HC emission amount of the engine having no VTC, and the thick solid line is the present embodiment. Thus, the HC discharge amount in the VTC having the hydraulic switch 26, the thin solid line indicates the HC discharge amount in the VTC without the hydraulic switch 26, the one-dot chain line indicates the engine speed, and the two-dot chain line indicates the hydraulic pressure.

  In FIG. 8, the lower broken line shows the relationship between the elapsed time and the operation start timing of each VTC, and the thick solid line has the hydraulic switch 26 of the present embodiment, and the thin solid line has no hydraulic switch. Shows the case.

  Looking at this figure (lower side), when the hydraulic switch 26 is not provided (thin solid line), the operation of the VTC is started after about 3 seconds after the ignition key is turned on, and then the vane member 3 is moved to about 2 It turns out that it rotates slowly in a second.

  On the other hand, when the hydraulic switch 26 is provided (thick solid line) as in the present embodiment, the rising of the hydraulic pressure can be detected quickly, so that the VTC operation start speed by the electronic controller 36 is set to 3 seconds or less. Is possible.

  Therefore, when looking at the upper side of the figure, the amount of HC emission is about 3 seconds after the start of engine rotation, especially when there is no hydraulic switch (thin line) compared to that without VTC (dashed line). It can be seen that there is a slight decrease in 5 seconds.

  On the other hand, when the operation start time of the VTC is advanced by the hydraulic switch 26 as in this embodiment, the HC discharge amount has a hydraulic switch in the time zone after the start of the engine rotation, as shown by a thick solid line. Compared with those not having VTC, it is reduced by about 34.1%, which is 30% or more.

  As described above, in this embodiment, in addition to the above-described effects, it is apparent that the HC emission amount in the exhaust gas at the time of starting the engine can be significantly reduced by providing the hydraulic switch 26.

  FIG. 9 shows a further different control flow by the electronic controller 36. This routine is performed, for example, every 8 ms (milliseconds) when the ignition key is turned on.

  First, it is detected in step 1 that the ignition key is turned on, and in step 2, it is determined whether or not the signal output from the hydraulic switch 26 is turned on. That is, it is determined whether or not the hydraulic pressure in the second oil passage 20 has reached a predetermined pressure. Here, as described above, when it is determined that the predetermined pressure has not yet been reached (off), the process returns to step 2, and when it is determined that the predetermined pressure has been reached (on), the process proceeds to step 3.

  In step 3, the operation of the delay timer is started, and the process proceeds to step 4. Here, it is determined whether or not a predetermined delay time, for example, 3 seconds has elapsed, and if not, the process returns to step 4 as it is, and if it is determined that 3 seconds have elapsed, the hydraulic pressure has increased sufficiently. Therefore, in step 5, the process for starting the normal control of the phase change mechanism is performed and the process ends.

  In this embodiment, after the hydraulic switch 26 is turned on, the operation start timing of the VTC is slightly delayed by the delay timer. Therefore, as shown in the hydraulic characteristic diagram of FIG. 10, the VTC is activated when the hydraulic pressure is sufficiently increased. I can do it. This makes it possible to obtain a reliable and stable operation of the VTC.

  In other words, if hydraulic oil is discharged from each retarded angle chamber 18 after a long engine stop, the operation will become unstable due to the rise in hydraulic pressure at the time of restart, but the above disadvantages can be avoided by using a delay timer. It becomes possible to wipe out.

  FIG. 11 shows a further different control flow of the electronic controller 36, in which the engine oil temperature by the water temperature sensor is added to the control conditions.

  In step 11, it is detected that the ignition key is turned on, and in step 12, the current water temperature (oil temperature) is detected from the water temperature sensor.

  In step 14, the time of the delay timer is calculated based on the information signal from the water temperature sensor. That is, when the oil temperature is lower than the predetermined value, the viscosity of the hydraulic oil is high. Therefore, the delay time is set longer, and when the oil temperature is higher than the predetermined value, the delay time is set shorter.

  In step 14, it is determined whether or not the hydraulic switch 26 is turned on. If the hydraulic switch 26 is turned off, the process returns to step 14 because the hydraulic pressure is low. If it is turned on, the delay timer is activated in step 15. Let

  In step 16, it is determined whether or not the delay time has passed the set time. If it is determined that the delay time has not yet passed, the process returns to step 16, and if it has passed, the process proceeds to step 17.

  In this step 17, since the viscosity of the hydraulic oil is low and the hydraulic pressure is sufficiently high, processing for starting the VTC control is performed.

  Thus, in this embodiment, since the VTC is controlled in consideration of the viscosity of the hydraulic oil in addition to the hydraulic pressure, the VTC can be controlled with higher accuracy.

  FIG. 12 shows a fourth embodiment in which the hydraulic switch 50 is connected to the supply passage 21 between the oil pump 25 and the hydraulic control valve 23 to detect the hydraulic pressure in the supply passage 21. The hydraulic switch 50 detects an abnormality in hydraulic pressure attached to a normal engine.

  Then, the electronic controller 36 estimates that the hydraulic pressure has increased when a predetermined time has elapsed after a signal indicating that the discharge pressure of the oil pump 25 is not abnormally low is output from the hydraulic switch 50, and thus the VTC is increased. The energization control for the hydraulic control valve 23 is performed so as to start the normal relative rotational phase control according to the above.

  Therefore, it is possible to ensure a suitable relative rotational phase at the time of starting the engine without specially providing a hydraulic pressure detecting means, to perform normal control promptly, and to suppress an increase in cost.

  The present invention is not limited to the configuration of each of the above embodiments. For example, the present invention can also be applied to an exhaust valve. In this case, when the engine is started, the VTC is relative to the crankshaft and the camshaft 2. The rotational phase is controlled to the advance side.

  Further, as a method of preventing inadvertent forward / reverse rotation of the vane member 3 by the air pressure when the engine is started, in addition to increasing the spring force of the spring member 42 of the restraining mechanism 37, the pressure receiving area of the lock pin 39 is reduced. It is also possible to cope with this.

  The technical ideas other than the invention described in the claims, as grasped from the embodiment, will be described below.

  (1) The control means controls the hydraulic control valve when starting the engine to supply hydraulic pressure to one of the advance chamber or the retard chamber and maintain a phase suitable for startup, When the hydraulic pressure detected by the detection means becomes equal to or higher than a predetermined value, or after it is estimated that the hydraulic pressure is higher than a predetermined value, the hydraulic pressure control valve controls the hydraulic pressure to be supplied to the other of the advance chamber or the retard chamber. The valve timing control device for an internal combustion engine according to claim 1, wherein the valve timing control device is an internal combustion engine.

  (2) The hydraulic pressure at which the control means controls the hydraulic control valve to start normal control is equal to or higher than the air pressure staying in the advance chamber and / or the retard chamber. A valve timing control device for an internal combustion engine as described.

  The hydraulic control valve starts normal control due to the pressure generated when the air staying in the advance chamber or retard chamber while the engine is stopped is compressed through the phase change mechanism by the hydraulic pressure pumped from the oil pump. Can be prevented.

  In addition, the phase change mechanism is not controlled in a state where a large amount of air stays in the advance chamber or retard chamber, and the control is performed with hydraulic pressure higher than air pressure. There is no deterioration.

(3) The restraining mechanism is configured such that the restraining member is engaged with the restraining hole by the urging member, and the restraining member is disengaged from the restraining hole by the hydraulic pressure.
The valve timing control for an internal combustion engine according to claim 3, wherein the restraint maintaining means is configured by adjusting a pressure receiving area where the restraint member receives hydraulic pressure and / or a biasing force of the biasing member. apparatus.

  According to this invention, it is possible to make it difficult to release the restraining member from the restraining hole by air pressure by reducing the pressure receiving area of the restraining member or by setting the biasing force of the biasing member large.

  (4) The valve timing control device for an internal combustion engine according to (3), wherein the abnormality detecting means is constituted by a pressure switch.

  (5) The temperature detecting means for detecting the engine temperature is provided, and the normal phase change control according to the operation state of the oil pressure control valve is detected in accordance with the engine operating condition, which is detected by the oil pressure abnormality detecting means. 4. The valve timing control device for an internal combustion engine according to claim 3, wherein the time until starting the operation is variably controlled based on the temperature information detected by the temperature detecting means.

  Normally, the viscosity of hydraulic oil changes depending on its temperature, and the way in which hydraulic pressure rises differs depending on this viscosity.

  For this reason, in the present invention, it becomes possible to perform fine control based on information from the temperature detection means until the abnormal state of the hydraulic pressure, that is, the abnormal low hydraulic pressure is released and the hydraulic pressure can control the phase change mechanism. .

  Therefore, the phase change mechanism can be controlled as early as possible.

  (6) The valve timing control device for an internal combustion engine according to (1), wherein the oil pressure detecting means detects an oil pressure between the oil pressure control valve and a phase change mechanism.

  According to the present invention, the hydraulic pressure that can be controlled by the phase change mechanism by the hydraulic pressure detection means can be detected accurately and promptly. As a result, it is possible to prevent a decrease in control accuracy of the phase change mechanism.

It is the schematic which shows 1st Embodiment of the valve timing control apparatus of this invention. It is sectional drawing of the valve timing control apparatus. It is sectional drawing which shows the rotation position of the most retarded angle side of the vane member in this embodiment. It is sectional drawing which shows the rotation position by the side of the most advance angle of the vane member in this embodiment. It is a fragmentary sectional view which shows the restraint mechanism with which this embodiment is provided. It is the schematic which shows the effect | action of this embodiment. It is the schematic which shows the further different effect | action of this embodiment. It is a graph which compares and shows the characteristic of HC discharge amount, such as this embodiment. It is a flowchart figure of 2nd Embodiment. It is a graph which shows the starting characteristic of oil pressure in a 2nd embodiment, etc. It is a flowchart figure of 3rd Embodiment. It is a block diagram which shows 4th Embodiment.

Explanation of symbols

1. Timing sprocket (drive member)
2 ... Camshaft 3 ... Vane member (driven member)
4 ... Hydraulic circuit 5 ... Housing 10 ... Partition 14
23 ... Hydraulic control valve 25 ... Oil pump 26 ... Hydraulic switch (hydraulic detection means)
30-34 ... port 36 ... electronic controller (control means)
37 ... restraint mechanism 42 ... spring member (restraint maintaining mechanism)
50. Hydraulic switch (hydraulic pressure abnormality detecting means)

Claims (1)

A phase change mechanism that changes the relative rotation phase of the camshaft with respect to the crankshaft by selectively supplying and discharging hydraulic pressure to and from the advance chamber and the retard chamber;
A hydraulic control valve for controlling the hydraulic pressure supplied to and discharged from the advance chamber or retard chamber;
A hydraulic pressure detection means for detecting a hydraulic pressure between the phase change mechanism and the hydraulic pressure control valve supplied to the advance angle chamber or the retard angle chamber when the engine is started;
Control means for starting the control of the hydraulic control valve in accordance with the engine operating state after a predetermined time has elapsed after the ignition key is turned on and the hydraulic pressure detection means detects that the hydraulic pressure has become equal to or higher than a predetermined value; ,
A valve timing control apparatus for an internal combustion engine, comprising:

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