JP2008002324A - Phase angle detector and valve timing controller of internal-combustion engine using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a phase angle detector which detects an intermediate rotation phase controlled by a phase changing mechanism to permit control accuracy to be improved. <P>SOLUTION: The phase angle detector is provided between a sprocket 2 and a cam shaft and makes braking force work on a hysteresis ring by electromagnetic force emanated from an electromagnetic coil to change a relative rotation phase between both the sprocket 2 and the cam shaft. There are provided four target protrusions 25 at equally spaced positions in a peripheral surface of the sprocket and further at equally spaced positions in a peripheral surface of a spiral disc 13, four narrow second target protrusions 26 which is set at a 20° lagged angle relative to a first target protrusions. Furthermore, there is provided an angle detecting sensor 27 which generates each of pulse signals from the first and second target protrusions and then the angle detecting sensor 27 is allowed to detect at least an intermediate phase angle by means of a controller 24 depending on intervals between both the pulse signals. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a phase angle detection device that detects a rotational phase difference between at least two rotating bodies, and, for example, a valve of 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. The present invention relates to a phase angle detection device used for a timing control device or the like.

  As a conventional valve timing control device, there is one as described in the following Patent Document 1 previously filed by the present applicant.

  This valve timing control device is connected to a timing sprocket to which rotational force is transmitted from a crankshaft of an engine, a camshaft supported so as to be relatively rotatable with respect to the timing sprocket within a predetermined angle range, and the camshaft. And a phase changing mechanism that is provided between the timing sprocket and the sleeve and converts the relative rotational phase of the timing sprocket and the camshaft in accordance with the engine operating state.

  The phase changing mechanism includes a radial guide window formed on the timing sprocket, a spiral guide (spiral groove) formed on the vortex disk, and a base end portion rotatably provided on the sleeve. A link member disposed in the radial guide so as to be movable in the radial direction, an engagement portion provided at a distal end portion of the link member, and a spherical portion of the distal end engaged with the spiral guide, and engine operation And a hysteresis brake for applying a braking force to the vortex disk according to the state.

And it supplies with electricity to the electromagnetic coil of a hysteresis brake, and an electromagnetic brake is made to act on the said vortex disk via a hysteresis material. Accordingly, the engaging portion slides in the spiral guide while moving in the radial direction along the radial guide window, and the timing sprocket and the sleeve (camshaft) are relatively moved within a predetermined angle range. Rotate. Thereby, the opening / closing timing of the intake valve is variably controlled according to the engine operating state.
JP 2005-180307 A

  By the way, in the conventional valve timing control device, as a method of detecting the relative rotation angle between the timing sprocket and the camshaft, the cam angle information of the cam angle sensor in which the controller detects the cam rotation angle of the camshaft. And the crank angle information of the crank angle sensor for detecting the rotation angle of the crankshaft, and calculating the phase difference from the cam rotation angle of the camshaft with reference to the crank rotation angle of the crankshaft. It has become.

  On the other hand, in the electromagnetic brake type valve timing control device, the vortex disk is usually controlled to rotate to the most retarded angle side by a spring force when the engine is stopped, and after the engine is started, the action of the electromagnetic brake is performed. As the engine rotation increases, rotation is controlled to the advance side.

  However, for example, by changing the curvature of the spiral guide of the vortex disk in the vicinity of the most retarded angle side and improving the startability required when starting the engine, the one end side of the spiral guide is slightly advanced. After that, when the electromagnetic brake is applied to shift to the predetermined rotation range from the one end side to the other end side, the retarded side is set, and the same electromagnetic brake is applied. In this case, if the electromagnetic brake is applied from the start of the engine, both the retard angle control and the advance angle control are performed continuously when it is set to be the advance angle side when passing through the most retarded angle side. In this state, it becomes difficult to detect the relative rotational phase difference between the cam angle sensor and the crank angle sensor. That is, because the same electromagnetic brake action caused by energization results in different movements on the retard side and the advance side, it is difficult to perform phase control with both the cam angle and crank angle sensors.

  In other words, only the detection information of each of the cam angle sensor and the crank angle sensor is insufficient in accuracy as a control amount of a valve timing control device such as the electromagnetic brake type, for example, and highly accurate valve timing control is performed. It becomes impossible to do.

  The present invention has been devised to solve the conventional technical problem, and the invention according to claim 1 is directed to an intermediate rotating body that changes an operating angle of a driven member to be driven, and the driven member. A detection unit for detecting a pulse signal output from the intermediate rotating body corresponding to the changed operating angle, and detecting and outputting a phase difference signal with respect to a preset reference pulse from the detected pulse signal An output unit, and detecting a predetermined intermediate angle position in the entire operating angle of the driven member based on the phase difference signal.

  According to the present invention, not the operation phase angle of the driven member, but the operation phase angle of the intermediate rotating body is directly detected, and the phase angle difference between the drive member and the driven member is detected by the detected pulse signal and the reference pulse signal. Therefore, it is possible to expand the range of detected values to be detected. As a result, it is possible to detect an intermediate operation angle of the entire operation angle, and it is possible to improve the detection accuracy of the phase angle.

  Note that the present invention is not limited to the valve timing control device for the internal combustion engine.

  According to a second aspect of the present invention, there is provided a driving rotating body that is rotationally driven synchronously by a crankshaft of an engine, a driven rotating body coupled to a camshaft having a cam that opens and closes an engine valve, and the driving A phase changing mechanism for changing the relative rotational phase angle between the rotating body and the driven rotating body according to the rotation angle of the intermediate rotating body, and detection for detecting a pulse signal output corresponding to the rotating angle of the intermediate rotating body And an output unit that detects and outputs a phase difference signal with the driven rotor by a pulse signal detected by the detector and a reference pulse corresponding to a rotation angle of the drive rotor, Based on the phase difference signal, a predetermined intermediate angle position in the entire rotation angle of the driven rotating body is detected.

  Since the present invention further restrictively describes the invention of claim 1, the same effect as that of the invention of claim 1 can be obtained.

  The invention according to claim 3 is applied to a valve timing control device for an internal combustion engine, wherein the rotational phase angle of a cam provided on a camshaft for operating the engine valve is made variable for the rotation angle of an intermediate rotating body. Detecting the phase change mechanism that changes by rotating, the rotation angle of the intermediate rotator and the rotation angle of the drive rotator driven synchronously by the crankshaft, and the rotational position of the intermediate rotator and the drive rotator A detection mechanism for detecting a phase difference, and based on the phase difference signal output from the detection mechanism, the engine valve opening / closing timing retardation control region in the entire rotational phase region of the driven rotor is advanced. It is characterized by detecting an intermediate phase position with respect to the angle control region.

  Hereinafter, an embodiment in which a phase angle detection device according to the present invention is applied to a valve timing control device for an internal combustion engine will be described with reference to the drawings. In this embodiment, the present invention is applied to the valve operating system on the intake side of the internal combustion engine. However, it can be similarly applied to the valve operating system on the exhaust side of the internal combustion engine.

  That is, as shown in FIGS. 1 to 9, the valve timing control device includes a camshaft 1 rotatably supported by a cylinder head (not shown) of the internal combustion engine, and a front end side of the camshaft 1 as required. A timing sprocket 2 that is a drive rotating body (driving member) provided so as to be relatively rotatable, and a phase changing mechanism that is arranged on the inner peripheral side of the timing sprocket 2 and changes the relative rotational phase of both 1 and 2 3 is provided.

  The camshaft 1 has two cams 1a and 1a per cylinder for opening the intake valve on the outer periphery, and a driven shaft member 4 which is a driven rotating body (driven member) at the tip end portion is driven by a cam bolt 5 from the axial direction. The sleeve 6 is screwed and fixed to the distal end portion of the driven shaft member 4.

  The driven shaft member 4 has a cylindrical shaft portion 4a through which the cam bolt 5 is inserted through an internal through hole, and a stepped diameter shape integrally formed on the end of the shaft portion 4a on the camshaft 1 side. And a large-diameter enlarged portion 4b. Further, a male screw to which the sleeve 6 is screwed is formed on the outer periphery of the distal end portion of the shaft portion 4a.

  The sleeve 6 is formed with a female screw 6a that is screwed into the male screw of the shaft portion 4a on the inner peripheral surface of the base end portion on the camshaft 1 side, and after being screwed into the shaft portion 4a to the maximum, The leading portion of 6a is fixed to the tip surface side of the shaft portion 4a by an annular caulking to prevent rotation.

  The timing sprocket 2 has a ring-shaped gear gear 2a that is linked to the crankshaft on the outer periphery via a timing chain (not shown) integrally formed on the outer periphery, and is substantially circular on the inner peripheral side of the gear gear 2a. A plate-like plate member 2b is provided. Further, it is rotatably supported on the outer periphery of the shaft portion 4a of the driven shaft member 4 through the inner peripheral surface of the insertion hole 2c formed at the center of the plate member 2b. Note that a second sprocket 2 'for driving auxiliary machinery is coupled to the end of the timing sprocket 2 on the camshaft 1 side by a bolt.

  The plate member 2b is formed with two radial window holes 7 and 7 which are radial guides having parallel side walls facing each other so as to extend substantially along the radial direction of the timing sprocket 2. Between the two radial window holes 7, 7, two guide holes 2d in which the base end portions 8a, 8a of the two link members 8, 8 being movable members are engaged and held so as to be movable in the circumferential direction, 2d is formed through.

  The guide holes 2d and 2d are formed in an arc shape along the circumferential direction in the outer peripheral portion of the insertion hole 2b, and the axial length thereof is within a range in which the base end portions 8a and 8a move ( The size of the camshaft 1 and the timing sprocket 2 is set within a range of relative rotation.

  Each of the link members 8 is bent in a substantially arc shape, and each base end portion 8a on one end side is formed in a cylindrical shape, while each tip end portion 8b, 8b on the other end side is also cylindrical. Each of them is projected in the direction of the plate member 2b. In addition, holding holes are formed through two lever protrusions that protrude radially from the inner peripheral side of the end of the enlarged shaft portion 4b of the driven shaft member 4 on the camshaft 1 side. One end of each pin 9, 9 is press-fitted and fixed, and the base end 8a, 8a of each link member 8, 8 is rotatably connected to the other end of the pin 9, 9.

  Further, the end portions 8b and 8b of the link members 8 and 8 are engaged with the radial window holes 7 and 7, respectively.

  In addition, a housing hole 10 that opens to the front side in the axial direction is formed at the distal end portion 8 b of each link member 8, and a vortex disk 13 to be described later is inserted into the housing hole 10 through each radial window hole 9. An engagement pin 11 that is an engagement portion having a spherical tip portion that engages with the spiral groove 15 and a coil spring 12 that biases the engagement pin 11 forward (spiral groove 15 side) are accommodated. Has been.

  Each link member 8 is connected to the driven shaft member 4 via pins 9 and 9 in a state where each distal end portion 8b is engaged with each corresponding radial window hole 9. Therefore, when the distal end portions 8b and 8b of the link member 8 are displaced along the radial window holes 9 by receiving external force, the timing sprocket 2 and the driven shaft member 4 are connected to the link members 8 and 8 respectively. The base end portions 8a and 8a move along the guide holes 2d and 2d, and rotate relative to each other in a direction and an angle corresponding to the displacement of the front end portions 8b and 8b.

  On the other hand, a disk-like vortex disk 13 disposed opposite to the front side of the plate member 2b is rotatably supported via a ball bearing. The vortex disk 13 includes a cylindrical part 13a to which the outer ring of the ball bearing 14 is fixed, and a disk part 13b integrally provided at the rear end of the cylindrical part 13a. Two spiral grooves 15 having a semicircular cross section, which are spiral guides, are formed on the rear surface of the shaft 1 side. The distal end portions of the engagement pins 11 of the link members 8 are slidably engaged and guided in the spiral grooves 15.

  Further, the vortex disk 13 is a high-density sintering comprising a pre-sintering step of pre-sintering the molded powder metal, and then a re-compression process of compressing the pre-sintered intermediate rotating body with high pressure. Molded by law. Accordingly, the spiral grooves 15 are also formed simultaneously when the vortex disk 13 is formed of a sintered alloy.

  As shown in FIGS. 6 to 9, the spiral grooves 15 are separated from each other and formed so as to gradually reduce the diameter along the rotation direction of the timing sprocket 2, and the outermost end tip groove portion 15 a. Are bent (biased) inward at a predetermined angle. That is, the tip groove portion 15a is formed to be bent inward at a small angle inward from the substantially central position in the longitudinal direction.

  Specifically, each spiral groove 15 is formed with a constant vortex (phase) change rate in the general portion 15b other than the tip groove portion 15a, but the tip groove portion 15a has a vortex change rate. Is formed smaller than the general portion 15b toward the tip from the bent portion 15c bent inward, and is formed substantially linearly along the tangential direction of the vortex disk 13, and the tip groove 15a The length L is set to be relatively long.

  In other words, the vortex disk 13, each spiral groove 15, each link member 8, the engaging portion 11 and the like constitute a reduction mechanism, and the spiral groove 15 has its reduction ratio, that is, as shown in FIG. The reduction ratio of the camshaft 1 and the timing sprocket 2 to the phase conversion angle θ1 with respect to the rotation angle θ of the vortex disk 13 is set to be constant, whereas in the section of the tip groove portion 15a, the reduction ratio is 6 It is set to be larger than the above, that is, set to have a ratio of at least θ: θ1 = 1: 6.

  When the engagement pin 11 is engaged with the spiral groove 15 and the vortex disk 13 rotates relative to the timing sprocket 2 in the delay direction, the distal end portion 8b of each link member 8 is connected to each radial window hole. 9 and guided to the spiral shape of the spiral groove 15 to move radially inward (advance side), and conversely, when the vortex disk 13 is relatively displaced in the advance direction, it moves radially outward, The engagement pin 11 is controlled to the most retarded angle side in a state where the engagement pin 11 is positioned at the bending portion 15 c of the spiral groove 15.

  Further, when the engagement pin 11 is positioned in the tip groove portion 15a region of the spiral groove 15, the engagement pin 11 is controlled to be a slightly advanced position suitable for starting the engine.

  The vortex disk 13 receives a rotation operation force relative to the camshaft 1 by an operation force applying mechanism, and the operation force passes through each spiral groove 15 and the distal end portion 11a of each engagement pin 11 to link member 8. The distal end portion 8b is displaced in the radial direction in each radial window hole 9, and at this time, the relative rotational force is transmitted to the timing sprocket 2 and the driven shaft member 4 by the action of the link member 8.

  As shown in FIG. 1, the operating force applying mechanism includes a torsion spring 16 that is an urging means for urging the vortex disk 13 in the rotational direction of the timing sprocket 2 via the sleeve 6, and timings the vortex disk 13. A hysteresis brake 17 that is an electromagnetic brake that applies a braking force in a direction opposite to the rotation direction of the sprocket 2 and a controller 24 that controls the braking force of the hysteresis brake 17 according to the engine operating state are provided. Thus, by appropriately controlling the braking force of the hysteresis brake 17, the vortex disk 13 is rotated relative to the timing sprocket 2, or both rotation positions are maintained.

  As shown in FIG. 1, the torsion spring 16 is disposed on the outer peripheral side of the sleeve 6, and its one end 16 a is inserted and locked in a radial direction in a locking hole formed at the tip of the sleeve 6. On the other hand, the other end portion 16b is inserted and locked in a locking hole formed in the inner axial direction of the cylindrical portion 13a to urge the vortex disk 13 to rotate in the starting rotation phase direction after the engine stops. ing.

  On the other hand, the hysteresis brake 17 includes a hysteresis ring 18 fixed to the front end of the outer periphery of the vortex disk 13, an annular coil yoke 19 disposed at the front end of the hysteresis ring 18, and the coil yoke. The electromagnetic coil 20 is housed and arranged inside the coil yoke 19 and induces magnetism in the coil yoke 19. The electromagnetic coil 20 is energized and controlled by the controller 24 in accordance with the operating state of the engine. Magnetic flux is generated.

  The hysteresis ring 18 is formed of a hysteresis material (semi-hard material) having a characteristic that the magnetic flux changes with a phase lag with respect to the change of the external magnetic field, and as shown in FIG. The yoke 19 is disposed in a non-contact state in a gap between the pole teeth 21 and 22 on the inner and outer peripheral surfaces of the yoke 19 which will be described later, and receives a braking action by the coil yoke 19.

  The coil yoke 19 is formed in a substantially cylindrical shape so as to surround the electromagnetic coil 20, and is rotatably supported on the cylindrical portion 13a via a ball bearing 23 on the inner peripheral side. It is fixed to the engine cover via a backlash absorbing mechanism.

  2 to 4, the coil yoke 19 has an annular yoke portion 19a on the inner peripheral side of the space portion on the rear surface side (vortex disk 13 side), and the inner peripheral surface of the space portion. A plurality of convex pole teeth 21 and 22 are provided at equal intervals in the circumferential direction on the outer peripheral surface of the annular yoke portion 19a facing the inner peripheral surface.

  Each of the opposing pole teeth 21 and 22 is a magnetic field generator, and one pole tooth 21 and the other pole tooth 22 are alternately arranged in the circumferential direction, and the opposing inner and outer peripheral surfaces are adjacent to each other. The teeth 21 and 22 are all displaced in the circumferential direction. Therefore, a magnetic field having an inclination in the circumferential direction is generated between the adjacent pole teeth 21 and 22 on both opposing surfaces by excitation of the electromagnetic coil 20. The tip 18a of the hysteresis ring 18 is interposed in the gap between the pole teeth 21 and 22 in a non-contact state, and between the inner and outer peripheral surfaces of the tip 18a and the pole teeth 21 and 22. The air gap is set to a minute gap in order to secure a large magnetic force.

  The hysteresis brake 17 generates a braking force due to a deviation between the direction of the magnetic flux inside the hysteresis ring 18 and the direction of the magnetic field when the hysteresis ring 18 is displaced in the magnetic field between the opposing surfaces 21 and 22. The braking force is substantially proportional to the strength of the magnetic field, that is, the magnitude of the excitation current of the electromagnetic coil 20, regardless of the rotational speed of the hysteresis ring 18 (relative speed between the opposed inner and outer peripheral surfaces and the hysteresis ring 18). It becomes a constant value.

  The phase changing mechanism 3 includes a radial window hole 9 of the timing sprocket 2, a link member 8, an engaging pin 11, a lever projection, a vortex disk 13, a spiral groove 15, and an operation force applying mechanism described below. .

  As shown in FIGS. 1, 5, and 6, four first target protrusions 25 are arranged at equal intervals in the circumferential direction (90 on the outer peripheral surface of the timing sprocket 2 opposite to the gear gear 2 a. °) Integrated at the position. Each of the first target protrusions 25 is for picking up and detecting the rotation angle of the timing sprocket 2 (the rotation angle of the crankshaft) by an angle detection sensor 27 described later, that is, for obtaining a reference pulse signal.

  On the other hand, on the outer peripheral surface of the vortex disk 13, four second target protrusions 26 arranged close to the first target protrusions 25 in the axial direction of the camshaft 1 are positioned at equal intervals (90 °) in the circumferential direction. Are integrally provided. Each of the second target protrusions 26 is for picking up and detecting the rotation angle of the vortex disk 13 by the angle detection sensor 27 and extracting it as a pulse signal. Further, as shown in FIGS. 5, 6, and 11 </ b> A, each of the second target protrusions 26 is rotated in the rotational direction of the timing sprocket 2 from the position of the first target protrusion 25 (engine). It is provided at a position of a rotation angle (deg) of 20 ° in the opposite direction to the rotation direction. This is to prevent overlapping of the pulse signals of the both 25 and 26 from the initial position shown in FIG. 10 to be described later to the A region (bending portion 15c).

  The reason why the four target protrusions 25 and 26 are provided in the circumferential direction is that they can be detected in real time and that there is no overlap and overtaking of pulses in the A region.

  Furthermore, the circumferential width W of the first target protrusion 25 is set to be larger than the circumferential width W1 of the second target protrusion 26, whereby the angle detection sensors 27 are respectively connected to the respective angular detection sensors 27. It is designed to identify the target.

  The angle detection sensor 27 is also used as a normal crank angle sensor for detecting the engine speed, and uses a general Hall element, and the tip portion is close to the tip edges of the target projections 25 and 26. The protrusions 25 and 26 are arranged and detected by the Hall IC, and each pulse voltage is output to the controller 24.

  The target projections 25 and 26 and the angle detection sensor 27 constitute a detection mechanism.

  The controller 24 includes a crank angle from the angle detection sensor 27 that detects the engine speed, a cam angle sensor that detects the rotation angle of the camshaft 1, and an air flow meter that detects a load from the intake air amount of the engine. The current engine operating state is detected based on detection signals from various sensors such as the throttle valve opening and the engine water temperature sensor, and a control current is output to the electromagnetic coil 20 in accordance with the engine operating state.

  The controller 24 detects the rotational phase difference between the two and 13 from the rotational angle of the timing sprocket 2 and the rotational angle of the vortex disk 13 based on the pulse signal input from the angle detection sensor 27. Yes.

  Hereinafter, the operation of the electromagnetic brake of this embodiment will be described first. When the engine is stopped with the ignition key turned off, the excitation of the electromagnetic coil 20 of the hysteresis brake 17 is turned off so that the vortex disk 13 is maximized in the engine rotation direction with respect to the timing sprocket 2 by the spring force of the torsion spring 16. Keep rotating. Accordingly, as shown in FIGS. 6 and 7, the engagement pin 11 has a spherical tip positioned on the tip side of the tip groove 15 a of the spiral groove 15, and the relative rotation phase between the crankshaft and the camshaft 1 (engine The valve opening / closing timing is held at a position slightly closer to the advance side that is optimal for starting. At this time, the second target protrusion 26 is at a rotation position of 20 ° in the direction opposite to the rotation direction of the timing sprocket 2 with respect to the first target protrusion 25.

  When the ignition key is operated to start the engine and the power is turned on, disturbance such as alternating torque may occur during cranking, and the vortex disk 13 may rotate carelessly. Since the engaging pin 11 is stably held in the tip 15d of the tip groove portion 15a of the spiral groove 15 and the relative rotational phase of the crankshaft and the camshaft 1 is in an optimum position for starting, the startability of the engine is improved. Become good.

  More specifically, when the engine is started, positive and negative alternating torque, which is one of disturbances, is generated on the camshaft 1, and this alternating torque is transmitted to the vortex disk 13 so that the hysteresis ring 18 is moved to the torsion spring. There is a risk of inadvertent rotation against the 16 spring force.

  However, in this embodiment, as described above, the region of the tip groove portion 15a of the spiral groove 15 is bent inward, and the reduction ratio is set to be larger than 6; The operating resistance in 15a (tip 15d) is increased and the vortex disk 13 can be held, and inadvertent rotation due to the alternating torque can be reliably controlled.

  Therefore, the rotational phase at the time of engine start is stably maintained, and as a result, good startability can be ensured.

  Thereafter, when the engine shifts to a low rotation range such as idle operation, a magnetic force is generated in the hysteresis brake 17 by the control current output from the controller 24 to the electromagnetic coil 20, and the braking force resists the force of the torsion spring 16. Is applied to the vortex disk 13. At this time, a relatively larger current than usual is supplied to the electromagnetic coil 20, whereby the engagement pin 11 quickly escapes from the tip groove portion 15 a of the spiral groove 15 and is biased. It can move quickly to the curved portion 15c.

  As a result, the vortex disk 13 rotates slightly in the reverse direction with respect to the rotation direction of the timing sprocket 2, whereby the engagement pin 11 at the tip of the link member 8 is guided to each spiral groove 15 and the link member 8. The tip 8b swings outward along the radial window hole 9, and the rotational phase angle of the timing sprocket 2 and the driven shaft member 4 is changed to the most retarded angle side by the action of the link member 8 as shown in FIG. Is done.

  As a result, the relative rotational phase of the crankshaft and the camshaft 1 is changed to the most retarded angle side suitable for low rotation. As a result, the engine rotation during idling can be stabilized and the fuel consumption can be improved.

  Then, when the operation of the engine shifts from this state to the normal operation and, for example, at a high rotation time, a command to change the rotation phase to the most advanced angle side is issued from the controller 24, and a larger current is supplied to the electromagnetic coil 20. Is supplied, and a large braking force against the force of the torsion spring 16 is applied to the vortex disk 13.

  As a result, the vortex disk 13 further rotates in the opposite direction with respect to the timing sprocket 2, whereby the engagement pin 11 at the tip of the link member 8 is guided to each spiral groove 15, and the tip portion 8 b of the link member 8 has a diameter. As shown in FIG. 9, the relative rotation angle of the timing sprocket 2 and the driven shaft member 4 is changed to the most advanced angle side by the action of the link member 8.

  As a result, the rotational phase of the crankshaft and the camshaft 1 is changed to the most advanced angle side, thereby increasing the engine output.

  And the characteristic of the rotation angle θ of the vortex disk 13 when it is controlled to the most retarded angle side at the middle position of the spiral groove 15, that is, the bent portion 15d and the bent portion 15c are moved from the tip groove portion 15a of the spiral groove 15. Then, the control margin up to the general part 15b has characteristics as shown in FIG.

  In FIG. 10, the relationship between the rotation angle θ of the vortex disk 13 and the rotation angle θ of the vortex disk 13 with respect to the rotation angle θ of the vortex disk 13 from the engine start to the high rotation described above is indicated by a solid line X (broken line). The relationship with the timing sprocket 2 (crankshaft) is indicated by a solid line Y (broken line).

  That is, first, when the relative rotation angle of the pitch R of the spiral groove 15 with respect to the rotation angle θ of the vortex disk 13 is viewed, as shown by the solid line X, the idle operation is started from the point a at the initial stage of engine startup (the tip 15d of the tip groove portion 15a). The A region up to point b, which is the most retarded angle position at the time, has a rising characteristic, but further shifts from the most retarded angle position b point during idle operation to the most advanced angle position during normal operation and high engine speed. In the region B up to the point c, a smooth continuous falling characteristic is obtained. Accordingly, when the rotation angle θ of the corresponding vortex disk 13 and the relative rotation angle of the timing sprocket 2 are viewed from the characteristics of the spiral groove 15, the idle operation is performed from the point a ′ at the initial stage of engine start as shown by the solid line Y. The region A up to the most retarded angle b 'at the time has a falling characteristic, but the region B from the most retarded angle b' to the most advanced angle c 'during normal operation to the most advanced angle c' is gentle. Continuous rise characteristics.

  Therefore, according to this embodiment, the advance angle region where the engine can be easily started is widened by reducing the unique shape of the tip groove portion 15a of the spiral groove 15, that is, by reducing the rate of change of the rotational phase (large reduction ratio). Therefore, the operating resistance with the engagement pin 11 in this region is increased.

  That is, when the alternating torque acts on the vortex disk 13 to rotate it toward the bent portion 15c, the engaging pin 11 is radially outwardly perpendicular to the tip 15d of the tip groove 15a (in the direction of the arrow in FIG. 7). The movement is surely restricted by hitting the outer peripheral edge of the tip 15d. For this reason, even if the various disturbances occur in the relative rotation direction such as the alternating torque, the vortex disk 13 is not inadvertently changed in relative rotation. That is, since the holding force at the starting rotational phase position with respect to the vortex disk 13 is improved, the engine is always stable and good startability can be obtained.

  In addition, after the engine is started, the energization amount to the electromagnetic coil 20 is increased to increase the braking force and the vortex disk 13 is rotated rapidly, so that the valve timing is controlled to the most retarded angle side and further to the most advanced angle side. It is possible to prevent a decrease in control responsiveness.

  The characteristics indicated by the broken lines P and Q in FIG. 10 are obtained when the entire spiral groove 15 is formed with a constant curvature without bending the tip groove portion 15a side of the spiral groove 15 as in this embodiment. The relationship (P) between the vortex disk rotation angle θ and the spiral groove pitch R, and the rotation phase difference (Q) between the vortex disk rotation angle θ and the camshaft 1 are shown.

  The phase angle at the intermediate point between the A area and the B area can be accurately detected by the angle detection sensor 27 and the controller 24.

  That is, the pulse signal output from the angle detection sensor 27 is as shown in FIGS. 11A to 11C. At the initial position at the initial stage of engine start, as shown in FIG. 11A, the pulse of the first target protrusion 25 is obtained. The signal S and the pulse signal D of the second target protrusion 26 are transmitted at equal intervals of 20 °.

  Next, when shifting from the engine start to the idling operation, a braking force is applied to the vortex disk 13 by energizing the electromagnetic coil 20, and when the intermediate positions b and b 'are reached, the first target protrusion 25 and The second target protrusion 26 is separated from the second target protrusion 26 by a predetermined angle, and the position 1 ′ of the second target protrusion 26 is further 50.5 ° from the position 20 ° apart from the position 1, 2, 3, 4 of the first target protrusion 25 2 ′, 3 ′, and 4 ′, that is, 70.5 ° angular positions as a whole.

  Further, when the engine shifts from normal operation to high rotation, when the action of the braking force on the vortex disk 13 continues and reaches the most advanced angle positions c and c ′, the first target protrusion 25 and the second target The protrusion 26 is further separated, and the both 25 and 26 are separated to an angular position of about 251 °.

  Therefore, by outputting this relative angle change to the controller 24, the relative rotation angle of the camshaft 1 and the timing sprocket 2 can be detected by the detection method described later.

  Hereinafter, the relative angle detection method by the controller 24 will be described based on the pulse signals output from the angle detection sensor 27 through the target protrusions 25 and 26 with reference to the flowcharts of FIGS.

  First, in step 1 of FIG. 12, the engine speed N (rpm) is read from the rotation speed of the timing sprocket 2 (crankshaft) obtained from the angle detection sensor 27 based on the first target protrusion 25.

  In step 2, the pulse widths of the first and second target protrusions 25 and 26 output from the angle detection sensor 27 are compared, and the larger one is the S signal (reference pulse signal) and the smaller one is the D signal. Recognize each as a signal.

  In step 3, the rise time difference Δt between the S signal and the D signal is detected, and in step 4, the phase difference θ1 is obtained from the Δt by the following equation.

θ = Δt / (N / 60) × 360 × 2 (° CA)
In step 5, the amount of change described above is calculated from the phase angle 20 ° (crank angle 40 °) of the initial setting value, so that the rotational angle conversion angle between the timing sprocket 2 and the camshaft 1 is θ = θ1−. Obtained from the equation of 20 °.

  Thus, in the present embodiment, the rotation angle θ of the vortex disk 13, that is, the relative rotation between the timing sprocket 2 and the camshaft 1, depending on the relative rotation position between the first target protrusion 25 and the second target protrusion 26. The conversion angle θ can be detected.

  Next, a method for determining the A region and the B region and a control switching method will be described with reference to FIG.

  In step 11, the current rotation angle θ of the vortex disk 13 is detected, and in step 12, it is determined whether or not the current rotation angle θ is larger (equal) than θt. Here, θt is a phase angle at points b and b ′ in FIG. 10 which is the bent portion 15c of the spiral groove 15, and in this embodiment, the cam angle is set to 50.5 °.

  If it is determined in step 12 that the rotation angle (conversion angle) θ is equal to, for example, the phase angle θt at points b and b ′, it can be determined that the intermediate position (most retarded angle position) has been reached. When it is determined that the rotation angle θ is larger than the phase angle θt, it can be determined that the rotation angle θ is located on the c point side (advance angle side) with respect to the positions of the b and b ′ points.

  After determining that θ is equal to or larger than the phase angle θt, the process proceeds to step 13. In step 13, it is determined whether to control to the retard side or the advance side according to the current engine operating state.

  Here, when it is desired to shift θ to the retard side, for example, the routine proceeds to step 14. In this step 14, a process of reducing the amount of current supplied to the electromagnetic coil 20 is performed, whereby the vortex disk 13 is rotated to the retard side (point b direction) by the spring force of the torsion spring 16.

  If it is desired to shift θ to the advance side in step 13, the process proceeds to step 15. In step 15, a process for increasing the amount of current supplied to the electromagnetic coil 20 is performed. As a result, a braking force acts on the vortex disk 13 and rotates to the advance side.

  On the other hand, if it is determined in step 12 that the intermediate position (most retarded angle position) is reached or smaller than this intermediate position, the routine proceeds to step 16, where it is delayed according to the current engine operating state. It is determined whether to control to the angle side or to the advance side.

  That is, since the vortex disk 13 is at the intermediate position (most retarded position) or at the a point side, for example, when it is desired to move from the a point side to the intermediate position side, the process proceeds to step 17. .

  In this step 17, a process for increasing the energization amount to the electromagnetic coil 20 is performed. As a result, a braking force acts on the vortex disk 13 to rotate to the most retarded angle side (intermediate position), and further to the advance angle side beyond the most retarded angle position.

  Further, in step 16, since the intermediate position is reached, when it is desired to move from this point to the point a, the flow moves to step 18, where a process of reducing both energization to the electromagnetic coil 20 is performed. As a result, the vortex disk 13 is rotated toward the advance side (point a direction) by the spring force of the torsion spring 16.

  As described above, according to this embodiment, not the rotational phase angle of the camshaft 1 but the rotational phase angle of the vortex disk 13 is directly detected, and the timing is determined based on the detection pulse D signal and the reference pulse S signal. Since the phase angle difference between the sprocket 2 and the camshaft 1 is detected, the detected value range can be expanded. As a result, it is possible to detect an intermediate rotation angle (most retarded angle) of the entire rotation angle, and to improve the detection accuracy of the phase angle.

  Therefore, depending on the detection result, the electromagnetic coil 20 is energized and controlled to the retard side or the advance side, or the energization amount to the electromagnetic coil 20 is decreased and controlled to the retard side or the advance side is controlled. It becomes possible to judge whether.

  When the brake force is applied to the vortex disk 13 from the intermediate position (most retarded position) and the vortex disk 13 is rotated to the advance side, the second target is moved with respect to the first target protrusion 25 as shown in FIG. 11C. Since the projection 26 has overtaken and the phase difference cannot be detected at the relative position between the two 25 and 26, in this case, the first target projection 25 is used as a reference and compared with the cam angle signal from the cam angle sensor. Thus, the relative rotational phase difference between the timing sprocket 2 and the camshaft 1 is detected.

  In the present embodiment, since the hysteresis brake 17 is used as the phase change mechanism 3, a very high braking force can be obtained for the vortex disk 13 by the amount of current supplied to the electromagnetic coil 20. For this reason, as described above, by increasing the energization amount when starting normal control after starting the engine, it is possible to easily and effectively prevent the deterioration of the responsiveness of phase change when starting normal control after starting. be able to.

  Further, since the spiral groove 13 can be formed in a desired shape except for the tip groove portion 15a where the change rate of the spiral groove 13 is small, the control after the engine is started is not affected, and the desired control is ensured. it can.

  Note that the relative rotational phase of the crankshaft and the camshaft 1 by this valve timing control device depends not only on the phase of the most retarded angle or the most advanced angle, but also on the amount of current supplied to the electromagnetic coil 20 in accordance with the engine operating state. By changing the braking force of the hysteresis brake 17, the rotation phase is changed to an arbitrary rotational phase. For example, the phase is changed to a substantially intermediate position with a cam angle of about 50.5 ° by the balance between the spring force of the torsion spring 16 and the braking force of the hysteresis brake 17. Can also be held.

  The present invention is not limited to the configuration of the above-described embodiment. As the phase change mechanism, the vortex disk 13 includes a plurality of gears that output a rotational force in one direction at a predetermined gear ratio. It may be configured by a harmonic drive mechanism, and in this case, at least one target protrusion for generating a pulse signal by a sensor may be provided on the operation output side of the harmonic drive mechanism.

  In addition to the sprocket, the one that transmits the driving force to the drive rotator may be a timing pulley that is driven by a rubber timing belt, or one that is driven by meshing of a gear and a gear.

  Furthermore, the phase changing mechanism can be applied to a helical gear type instead of the electromagnetic brake.

  Further, the biasing means for rotating and biasing the vortex disk of the phase changing mechanism in one direction is not limited to the torsion spring, and the positive and negative torque difference of the alternating torque from the camshaft is used as a power source to return to the starting rotation phase. You may set the convergence rate of a spiral groove.

  The radial guide only needs to be able to guide the engaging portion, and may be a guide groove or a guide projection in addition to the radial guide hole.

  The spiral guide is not limited to the bottomed groove, and may be a hole or a protrusion that penetrates the intermediate rotating body.

  The shape of the movable member may be any shape, for example, a roller or a ball provided on the sliding surface of the link tip.

The technical ideas other than the invention described in the claims, as grasped from the embodiment, will be described below.
(A) In the phase angle detecting device according to claim 2, the intermediate rotating body controls the rotational position of the cam in a range from the maximum phase advance position to the maximum retard position through the intermediate position. Constituted by a vortex disk having spiral grooves of
A follower portion that is coupled to the camshaft and moves in the radial direction of a sprocket that transmits the rotational driving force of the crankshaft to the camshaft while moving along the spiral groove,
A phase angle detection device that controls movement of the follower portion in a radial direction by controlling a rotation direction of the vortex disk.
(B) The phase angle detection device according to (a), wherein at least one target projection for generating a pulse signal by a sensor is provided on the outer surface of the vortex disk.
(C) In the phase angle detection device according to claim 2, the intermediate rotating body is a harmonic drive mechanism including a plurality of gears that output a rotational force in one direction at a predetermined gear ratio. Cam phase angle detector.
(D) The phase angle detection device according to (c), wherein at least one target protrusion for generating a pulse signal by a sensor is provided on the operation output side of the harmonic drive mechanism.
(E) In the phase angle detection device according to claim 2, the detection pulse signal corresponding to the rotation angle of the intermediate rotating body and the reference pulse signal corresponding to the angle of the crankshaft are at least different in pulse width. A phase angle detection device that detects a pulse signal of the intermediate rotating body and the reference pulse signal with two sensors.
(F) In the phase angle detection device of (e), the detection pulse signal and the reference pulse signal are specified from a difference in pulse width of the detected pulse signal, and the detection with respect to the specified reference pulse signal is performed. A phase angle detection device for calculating a delay of a pulse signal.

1 is a longitudinal sectional view showing an embodiment of a valve timing control device for an internal combustion engine to which a phase angle detection device according to the present invention is applied. It is the perspective view which decomposed | disassembled the valve timing control apparatus of this embodiment, and was seen from one direction. It is the perspective view which decomposed | disassembled the valve timing control apparatus of this embodiment, and was seen from the other direction. It is the sectional view on the AA line of FIG. It is a B arrow line view of Drawing 1 showing the 1st and 2nd target projection of this embodiment. It is the schematic which shows the state of the 1st, 2nd target protrusion and spiral groove in this embodiment. It is CC sectional view taken on the line of FIG. 1 which shows the operation state at the time of the rotation phase control at the time of starting of this embodiment. It is CC sectional view taken on the line of FIG. 1 which shows the operation state at the time of the most retarded angle phase control of this embodiment. It is CC sectional view taken on the line of FIG. 1 which shows the operation state at the time of the most advanced angle phase control of this embodiment. It is a characteristic view showing a control margin in the relationship between the rotation angle of the vortex disk and the conversion angle of the relative rotation phase in the present embodiment. A shows the pulse signals of the first and second target protrusions at the time of engine start, B shows the pulse signal at the time of the most retarded angle control, and C shows the pulse signal at the time of the most advanced angle control. It is a flowchart figure which shows the phase detection method by the controller of this embodiment. It is a control flowchart figure by the controller of this embodiment.

Explanation of symbols

1 ... Camshaft 2 ... Timing sprocket (drive rotor)
3 ... Phase change mechanism 4 ... Driven shaft member (driven rotor)
7. Radial window hole (radial guide)
11 ... engaging pin (engaging part)
13 ... Vortex disk (intermediate rotating body)
15 ... spiral groove (spiral guide)
15a ... Tip groove 15b ... General part 15c ... Bending part (bending point)
16 ... Torsion spring (biasing means)
17 ... Hysteresis brake 24 ... Controller (output unit)
25 ... 1st target protrusion 26 ... 2nd target protrusion 27 ... Angle detection sensor (detection part)

Claims (3)

An intermediate rotating body for changing the operating angle of the driven member to be driven;
A detection unit for detecting a pulse signal output from the intermediate rotating body corresponding to the changed operating angle of the driven member;
An output unit that detects and outputs a phase difference signal from the detected pulse signal and a preset reference pulse; and
A phase angle detection device that detects a predetermined intermediate angle position in the entire operating angle of the driven member based on the phase difference signal. A drive rotor that is driven to rotate synchronously by the crankshaft of the engine;
A driven rotor coupled to a camshaft having a cam for opening and closing the engine valve;
A phase change mechanism that changes a relative rotation phase angle between the drive rotator and the driven rotator according to a rotation angle of the intermediate rotator;
A detection unit for detecting a pulse signal output corresponding to the rotation angle of the intermediate rotating body;
An output unit that detects and outputs a phase difference signal based on a pulse signal detected by the detection unit and a reference pulse corresponding to a rotation angle of the driving rotating body;
A phase angle detection device that detects a predetermined intermediate angle position in the entire rotation phase angle of the driven member based on the phase difference signal. A valve timing control device for an internal combustion engine that controls the opening and closing timing of an engine valve according to the operating state of the engine or vehicle,
A phase change mechanism that changes the rotation phase angle of the cam provided on the camshaft that operates the engine valve by making the rotation angle of the intermediate rotating body variable;
A detection mechanism that detects a rotation phase difference between the intermediate rotator and the drive rotator by detecting a rotation angle of the intermediate rotator and a rotation angle of the drive rotator that is synchronously driven by a crankshaft. ,
Detecting an intermediate point between the retard control region and the advance control region of the opening / closing timing of the engine valve in the entire rotational phase angle of the driven member based on the phase difference signal output from the detection mechanism. An internal combustion engine valve timing control device.

Images