JP2007285183A - Variable phase device of engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent generation of heat due to friction in a variable phase device of an automobile engine. <P>SOLUTION: The variable phase device for varying the opening/closing timing of an intake valve or an exhaust valve of the engine (110), includes an electromagnetic clutch (42) for decelerating or accelerating a rotary drum. A plurality of magnets that are radially magnetized are fixed to the rotary drum. The magnets are respectively magnetized reversely to the adjacent magnets. The electromagnetic clutch includes an iron core having a plurality of magnetizing parts facing the magnetic poles of the magnets and a coil (120) wound around the iron core. A controller (102) and a coil driving circuit (104) control the direction and ON/OFF of the current supplied to the coil, based on a magnetic signal (c) transmitted from a magnetic sensor (108) for detecting the magnetic poles of the magnets, and a crank angle signal (a) and a cam angle signal (b) transmitted from the engine. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention transmits the rotation of the crankshaft of an automobile engine to a camshaft for opening and closing the intake valve or exhaust valve of the engine, and opens and closes the intake valve or exhaust valve depending on the operating state such as the engine load and the rotational speed. The present invention relates to a phase varying device for an automobile engine that changes timing.

  As such a phase variable device, the one disclosed in Patent Document 1 below is known. This is shown in FIG.

  This phase variable device is used in a form assembled to an engine case (phase variable device cover) (not shown) to open and close the intake valve or the exhaust valve, and the driving force of the crankshaft of the engine is transmitted by a chain (not shown). An annular outer cylinder portion 10 having a sprocket 12 and a driven-side circle that is disposed coaxially with the outer cylinder portion 10 and is rotatable relative to the outer cylinder portion 10 and constitutes a part of the camshaft 2. The annular inner cylinder part 20, the outer cylinder part 10 and the inner cylinder part 20 are respectively helically spline-engaged and interposed between the outer cylinder part 10 and the inner cylinder part 20, and move in the axial direction to move the outer cylinder part 10. An intermediate member 30 that changes the phase of the inner cylinder part 20 with respect to the inner cylinder part 20, and an electromagnetic control means that is provided on the opposite side of the inner cylinder part 20 from the side where the camshaft 2 is disposed and moves the intermediate member 30 in the axial direction. Electromagnetic brake 4 It is equipped with a door. The camshaft 2 is provided with a cam 2a for opening and closing one of the intake valve and the exhaust valve.

  The outer cylinder portion 10 includes a sprocket 12 provided with a ring-shaped concave portion 13 on the inner peripheral edge, and an inner flange plate 14 that is in close contact with the side surface of the sprocket 12 and defines a flange engaging groove 13A in cooperation with the concave portion 13. The inner flange plate 14 is fastened to the sprocket 12 together, and the spline engaging portion 17 with the intermediate member 30 is formed from a spline case 16 formed on the inner periphery. A large-diameter concave portion 13a on the opening side of the concave portion 13 of the outer cylinder portion 10 and a small-diameter concave portion 13b on the flange side of the concave portion 13 face the outer peripheral edge of the flange 24 on the inner cylindrical portion 20 side between the concave portions 13a and 13b. A step portion 13c is provided. Since the sprocket 12, the inner flange plate 14, and the spline case 16 are integrated by the fastening screw 11, the flange engagement groove 13A and the spline engagement portion 17 in the spline case 16 can be easily formed.

  Although a small-diameter sprocket 12A is fixed to the outer cylinder portion 10, this small-diameter sprocket 12A is connected to a sprocket of a phase variable device for opening and closing the other of the intake valve and the exhaust valve with a chain, although not shown. Thus, it is for controlling opening and closing of both the intake valve and the exhaust valve.

  By the way, male and female helical splines 32 and 33 are provided on the inner and outer peripheral surfaces of the intermediate member 30, and male helical splines 23 are provided on the outer peripheral surface of the inner cylinder portion 20, and the spline engagement of the inner peripheral surface of the spline case 16 is performed. A female helical spline is formed in the portion 17. The inner and outer splines 32 and 33 of the intermediate member 30 are helical splines in opposite directions, and the phase of the inner cylinder portion 20 is increased with respect to the outer cylinder portion 10 by a slight movement of the intermediate member 30 in the axial direction. It can be changed. A male screw portion 31 is formed on the outer peripheral surface of the intermediate member 30.

  The electromagnetic brake 40 includes an electromagnet (electromagnetic coil) 62 in a clutch case 60, and receives a braking force from the electromagnetic clutch 42 having a friction material 66 fixed to the clutch case surface and the friction material 66 of the electromagnetic clutch 42. And a torsion coil spring 46 interposed between the rotating drum 44 and the outer cylinder portion 10 in the axial direction. The electromagnetic clutch 42 has a pin 68 engaged with a hole provided in the engine case, and is supported by the engine case so that it can move in the axial direction but cannot rotate. The rotating drum 44 is rotatably supported on the inner cylinder portion 20 by the bearing 22, and a female screw portion 45 that is screwed into the male screw portion 31 of the intermediate member 30 is formed. When the rotating drum 44 rotates relative to the outer cylinder portion 10, the intermediate member 30 moves in the axial direction by the action of both screw portions 45 and 31.

  When the electromagnetic clutch 42 is OFF, no braking force is applied to the rotating drum 44, so the rotating drum 44 and the outer cylinder portion 10 are fixed at the initial position by the torsion coil spring 46, and the outer cylinder portion 10 and the inner cylinder 10 are fixed. The portion 20, the intermediate member 30, and the rotary drum 44 rotate integrally, and no phase difference is generated between the outer cylinder portion 10 and the inner cylinder portion 20. Then, since the inner cylinder part 20 is connected to the camshaft 2 and the outer cylinder part 10 is connected to a crank pulley provided on the crankshaft by a chain, the intake valve is operated at a normal timing according to the rotation of the crankshaft. Alternatively, the exhaust valve can be opened and closed.

  When the electromagnetic clutch 42 is turned on, a braking force due to friction acts on the friction material 66 and the rotary drum 44 provided in the electromagnetic clutch 42. When the braking force is applied to the rotating drum 44, the rotating drum 44 is delayed in rotation with respect to the outer cylindrical portion 10, and the intermediate member 30 moves rightward in FIG. The inner and outer helical splines 32 and 33 cause the inner cylinder part 20 to rotate with respect to the outer cylinder part 10, and the phase difference between the two changes. The rotating drum 44 is held at a position where the braking force and the spring force of the torsion coil spring 46 are balanced. By controlling the current supplied to the electromagnet of the electromagnetic clutch 42, the inner cylinder part 20 and the outer cylinder part 10 can be controlled to a desired phase difference. Thereby, the opening / closing timing of an intake valve or an exhaust valve can be changed appropriately.

  When the electromagnetic clutch 42 is turned off again, the braking force does not act on the rotating drum 44, and the intermediate member 30 rotates to the initial position by the action of the torsion coil spring 46, and the left and right in FIG. Move to the initial position in the direction. Then, the inner cylinder part 20 rotates to the initial position in the opposite direction with respect to the outer cylinder part 10, the phase difference between them disappears, and the intake valve or the exhaust valve is opened and closed at normal timing.

  By the way, the friction torque adding members 51 and 55 are interposed between the flange 24 of the inner cylinder part 20 and the side surface of the flange engaging groove 13A of the outer cylinder part 10, so that the relative relationship between the outer cylinder part 10 and the inner cylinder part 20 is relative. While increasing the friction torque of the sliding portion, the occurrence of a hitting sound that the tooth portions of the helical spline engaging portions 23, 32, 33, 17 between the intermediate member 30, the outer cylindrical portion 10 and the inner cylindrical portion 20 collide with each other is suppressed. ing.

  In addition, engine oil is supplied into the phase varying device through an inlet 73a of the camshaft 2, an oil passage in the camshaft 2, and an outlet 73b. The engine oil that has exited from the outlet 73b is supplied between the friction material 66 provided on the surface of the electromagnetic clutch 42 and the sliding surface between the rotary drum 44 and prevents overheating due to friction between the friction material 66 and the rotary drum 44. (For details, refer to Patent Document 1 below).

JP 2002-371814 A

  As described above, in the phase variable device, when the sliding surface temperature of the friction material 66 and the rotating drum 44 becomes high due to frictional heat, the antioxidant or friction dispersed in the engine oil is increased. The surface of the friction material, which is generally composed of a porous material, is clogged by the reaction product and insoluble matter of additives such as a regulator and a cleaning dispersant, and the friction torque generated in the friction material 66 and the rotary drum 44 is increased. The cooling mechanism for flowing engine oil between the friction material 66 and the rotating drum 44 becomes indispensable. In order to configure this cooling mechanism, the phase variable device has a problem that it is complicated and expensive.

  The present invention has been made in view of the above problems, and it is an object of the present invention to prevent a variable phase device for an automobile engine from generating heat due to friction and to reduce the cost with a simple structure.

  In order to achieve the above object, an invention according to claim 1 is directed to an outer cylinder portion to which rotation of an engine crankshaft is transmitted, and to open and close an intake valve or an exhaust valve of the engine that can rotate relative to the outer cylinder portion. An inner cylinder connected to a camshaft; and an intermediate member meshed with the outer cylinder and the inner cylinder by a helical spline, and the intermediate member is moved in the axial direction, whereby the outer cylinder and the inner cylinder In a phase varying device for an engine that changes the opening / closing timing of the intake valve or the exhaust valve by causing relative rotation between the rotating parts, a rotating drum that is screwed to the intermediate member, and a circumferential direction of the rotating drum An electromagnetic club comprising a plurality of magnets fixed to the rotating drum at a predetermined interval, an iron core provided with a plurality of magnetized portions exerting a magnetic force on the magnet at a predetermined interval in the circumferential direction, and a coil wound around the iron core H, a coil drive circuit for supplying power to the coil when the magnetizing portion is magnetized, a magnetic sensor for detecting the approach of the magnet and generating a magnetic signal, a crank angle signal and a cam sent from the engine A phase deviation that is a deviation from a set value of the phase between the cam angle and the crank angle is obtained from the angle signal, and the rotating drum is accelerated, decelerated or rotated at a constant speed based on the phase deviation and the magnetic signal. And a controller that sends a drive signal to the coil drive circuit to instruct the direction of the current supplied to the coil and ON / OFF when the magnet is magnetized, and the magnet is magnetized along the radial direction of the rotating drum and is adjacent to the magnet Are magnetized in opposite directions.

  The invention according to claim 2 is the invention according to claim 1, wherein the iron core is an annular body having a U-shaped cross section having a groove, the coil is disposed in the groove, and the magnetized portion is formed of the iron core. The outer magnetized piece and the inner magnetized piece are located on the outer peripheral side and the inner peripheral side on the same radial direction and face each other, and the magnet is disposed between the outer magnetized piece and the inner magnetized piece. .

  The invention according to claim 3 is the invention according to claim 1, wherein the iron core is an annular body having a U-shaped cross section having a groove, the coil is disposed in the groove, and the magnetized portion is formed of the iron core. An outer magnetized piece and an inner magnetized piece located on the outer peripheral side and the inner peripheral side on the same radial direction and facing each other, one magnetized piece of both magnetized pieces is longer than the other magnetized piece, and one magnetic pole of the magnet The front surface of the magnet is made to face the side surface of the one magnetized piece, and the side surface of the other magnetic pole of the magnet is made to face the tip surface of the other magnetized piece.

  The invention according to claim 4 is the invention according to claim 1, wherein the iron core is an annular body having a U-shaped cross section having a groove, the coil is disposed in the groove, and the magnetized portion is formed of the iron core. The outer magnetized pieces and the inner magnetized pieces are alternately arranged on the outer peripheral side and the inner peripheral side, and the magnets extend along the circumferential direction of the rotary drum, and the magnets are arranged in two rows between the outer magnetized pieces and the inner magnetized pieces. It is characterized by being arranged in.

  The invention according to claim 5 is the invention according to claim 1, wherein the iron core is an annular body having a U-shaped cross section having a groove, the coil is disposed in the groove, and the magnetized portion is formed of the iron core. The magnetized pieces are arranged on the outer peripheral side or the inner peripheral side, and a pair of adjacent magnets are bonded to each other, and the front surface of the magnetic pole faces the side surface of the magnetized piece.

  According to a sixth aspect of the present invention, there is provided an outer cylinder portion to which the rotation of the crankshaft of the engine is transmitted, and an inner cylinder coupled to a camshaft that is rotatable relative to the outer cylinder portion and opens and closes the intake valve or exhaust valve of the engine And an intermediate member that meshes with the outer cylinder part and the inner cylinder part with a helical spline, and the intermediate member is moved in the axial direction, thereby causing relative rotation between the outer cylinder part and the inner cylinder part. Then, in the engine phase varying device that changes the opening / closing timing of the intake valve or the exhaust valve, the rotating drum that is screwed to the intermediate member, and the rotating drum is fixed to the rotating drum at predetermined intervals along the circumferential direction of the rotating drum An electromagnetic clutch comprising a plurality of magnets, an iron core provided with a plurality of magnetized portions exerting a magnetic force on the magnet at predetermined intervals along the circumferential direction, and a coil wound around the iron core; and the magnetized portion is magnetized. A cam driving circuit that feeds power to the coil, a magnetic sensor that detects the approach of the magnet to generate a magnetic signal, and a crank angle signal and a cam angle signal sent from the engine. A phase deviation that is a deviation from a set value of the phase between the angle is obtained, and supplied to the coil when the rotating drum is accelerated, decelerated or rotated at a constant speed based on the phase deviation and the magnetic signal. And a controller that sends a drive signal for instructing the current direction and ON / OFF to the coil drive circuit. The iron core is a U-shaped annular body having a groove, and the coil is disposed in the groove. The magnets are magnetized along the axial direction of the rotating drum, and adjacent magnets are magnetized in opposite directions.

  The invention according to claim 7 is the invention according to claim 6, wherein the magnetized portion is composed of outer magnetized pieces and inner magnetized pieces alternately arranged on the outer peripheral side and the inner peripheral side of the iron core, and the magnet is the outer side. It is made to oppose the front-end | tip of a magnetization piece and an inner side magnetization piece.

  The invention according to claim 8 is the invention according to claim 6, wherein the magnetized portion is composed of an outer magnetized piece and an inner magnetized piece located on the outer peripheral side and the inner peripheral side of the iron core in the same radial direction and facing each other, The magnets are arranged in two rows along the circumferential direction of the rotating drum so as to face the tips of the outer magnetized pieces or the inner magnetized pieces.

  According to the phase varying device of the first aspect of the present invention, the rotating drum is not braked with the friction material of the electromagnetic clutch as in the prior art, but between the magnet fixed to the rotating drum and the magnetized portion of the electromagnetic clutch. Since the opening / closing timing of the intake valve or exhaust valve is changed by accelerating or decelerating the rotating drum by the electromagnetic force that acts, the frictional heat caused by the contact between the friction material of the electromagnetic clutch and the rotating drum may increase the temperature. Absent. For this reason, inconvenience due to engine oil deterioration does not occur, and a torsion coil spring for returning the friction material and the rotating drum to the initial position, a cooling mechanism for the electromagnetic clutch and the rotating drum is not required, and the structure is simplified, so that it is difficult to fail. Long life and low cost. In addition, each part of the phase varying device has a loose axial tolerance, but a strict tolerance is required in the radial direction. Therefore, if the magnet is magnetized in the radial direction of the rotating drum, the magnetic pole of the magnet Can be made sufficiently close to the magnetized portion of the electromagnetic clutch. As a result, a strong electromagnetic force is generated between the magnet of the rotating drum and the magnetized portion of the electromagnetic clutch, and acceleration or deceleration torque can be applied to the rotating drum, resulting in a small and highly efficient and high torque response. A highly variable phase variable device can be obtained.

  According to the invention of claim 2, the magnetized portion further comprises an outer magnetized piece and an inner magnetized piece located on the outer peripheral side and the inner peripheral side of the iron core in the same radial direction and facing each other, and the magnet is the outer magnetized piece. And the magnetic force acting between the pair of inner and outer magnetized pieces and the four magnetic poles positioned between the magnetized pieces, that is, the magnetic force acting between all the magnetized pieces and all the magnetic poles, It is possible to effectively apply acceleration or deceleration torque to the rotating drum, and to obtain a phase variable device having a smaller size, high efficiency and high torque, and good response.

  According to the invention of claim 3, one magnetized piece is longer than the other magnetized piece, the front surface of one magnetic pole of each magnet is opposed to the side surface of one magnetized piece, and the side surface of the other magnetic pole is the other magnetized piece. Because it is opposed to the tip surface of the magnetized piece, by the magnetic force acting between the pair of inner and outer magnetized pieces and the four magnetic poles positioned between the magnetized pieces, that is, by the magnetic force acting between all the magnetized pieces and all the magnetic poles, It is possible to effectively apply acceleration or deceleration torque to the rotating drum, and to obtain a variable torque device that is smaller, has high efficiency, and has high responsiveness. Further, the diameter of the phase varying device can be reduced by an amount corresponding to the overlap between the magnet and the tip surface of the other magnetized piece.

  According to the invention which concerns on Claim 4, a magnetizing part consists of the outer magnetization piece and inner magnetization piece which are alternately arrange | positioned by the outer peripheral side and inner peripheral side of an iron core, and a magnet follows the circumferential direction of a rotating drum, and is an outer magnetization piece. In addition, since it is arranged in two rows between the inner magnetized pieces, the magnetic force acting between the inner and outer magnetized pieces and the four magnetic poles positioned between the magnetized pieces effectively accelerates the rotating drum. Alternatively, a deceleration torque can be applied, and a variable phase device having a small size, high efficiency, high torque, and good response can be obtained.

  According to the fifth aspect of the present invention, the magnetized portion is a magnetized piece arranged on the outer peripheral side or the inner peripheral side of the iron core, and a pair of adjacent magnets are bonded to each other and the front side of the magnetic pole is placed on the front side of the magnetized piece. Since it faces the side surface, acceleration or deceleration torque can be effectively applied to the rotating drum by the magnetic force acting between two adjacent magnetized pieces and two magnetic poles positioned between the magnetized pieces. In addition, since the magnetized portion is not provided on one of the outer peripheral side and the inner peripheral side of the iron core, the structure of the iron core is simple and easy to manufacture, and the magnet is stacked on one of the outer peripheral side or the inner peripheral side of the core. Therefore, the diameter of the phase variable device can be reduced.

  According to the sixth aspect of the invention, the rotating drum is not braked with the friction material of the electromagnetic clutch as in the prior art, but by the electromagnetic force acting between the magnet fixed to the rotating drum and the magnetized portion of the electromagnetic clutch. Since the opening / closing timing of the intake valve or the exhaust valve is changed by accelerating or decelerating the rotating drum, the frictional heat caused by the contact between the friction material of the electromagnetic clutch and the rotating drum does not cause a high temperature. For this reason, inconvenience due to engine oil deterioration does not occur, and a torsion coil spring for returning the friction material and the rotating drum to the initial position, a cooling mechanism for the electromagnetic clutch and the rotating drum is not required, and the structure is simplified, so that it is difficult to fail. Long life and low cost. Further, since the magnet is magnetized in the axial direction of the rotating drum, the magnet fixed to the rotating drum and the magnetized portion of the electromagnetic clutch are arranged along the axial direction. Thereby, strict tolerance is required in the radial direction for each part of the phase variable device, whereas strict tolerance is not required in the axial direction, so the shape of the magnet magnetic pole and the magnetized portion of the electromagnetic clutch, Strict accuracy is not required for the size and the mounting position, and this phase variable device can be easily manufactured. Furthermore, the diameter of the phase varying device can be reduced, and mounting on the engine is facilitated.

  According to the seventh aspect of the present invention, the magnetized portion further comprises an outer magnetized piece and an inner magnetized piece arranged alternately on the outer peripheral side and the inner peripheral side of the iron core, and the magnet is the tip of the outer magnetized piece and the inner magnetized piece. Because the magnetic force acting between the three magnetized pieces and the two magnetic poles located between the magnetized pieces can effectively apply acceleration or deceleration torque to the rotating drum, making it even smaller and more powerful. A variable phase device with high efficiency and high responsiveness can be obtained.

  According to the eighth aspect of the present invention, the magnetized portion is composed of the outer magnetized piece and the inner magnetized piece located on the outer peripheral side and the inner peripheral side of the iron core in the same radial direction and facing each other, and the magnet is the outer magnetized piece or the inner magnetized piece Since it is arranged in two rows along the circumferential direction of the rotating drum so as to face the tip of the piece, it is effective due to the magnetic force acting between the pair of inner and outer magnetized pieces and the four magnetic poles positioned between the magnetized pieces. In addition, acceleration or deceleration torque can be applied to the rotating drum, and a more compact, highly efficient and high torque can be obtained, and a variable phase device with good response can be obtained.

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

  First, a phase variable device according to a first embodiment of the present invention will be described with reference to FIGS. 1A is a longitudinal sectional view of the phase varying device, FIG. 1B is a front view of a rotating drum of the phase varying device, and FIG. 1C is a phase diagram of the phase varying device. It is a front view of the electromagnetic clutch of a variable apparatus. FIG. 2 is a perspective view of the electromagnetic clutch. FIG. 3 is a cross-sectional view taken along line III-III in FIG. FIG. 4 is a diagram for explaining the principle of accelerating / decelerating the rotating drum. FIG. 5 is a block diagram of a control circuit that controls the current flowing through the coil of the electromagnetic clutch. FIG. 6 is a wiring diagram of the coil drive circuit and each coil. FIG. 7 is a flowchart illustrating a procedure for performing acceleration / deceleration control of the rotating drum.

  As shown in FIG. 1, this phase variable device is the same as the conventional phase variable device except for the electromagnetic control means 40a composed of the rotating drum 44 and the electromagnetic clutch 42 and the control circuit of the electromagnetic control means 40a. . Therefore, in this embodiment, the description of the same parts as in the prior art will be omitted, and the electromagnetic control means 40a and its control circuit will be described below.

  In the electromagnetic control means 40a of this phase varying device, as shown in FIG. 1B, 18 magnets 45 are fixed to the rotating drum 44 at equal intervals along the circumferential direction. Each magnet 45 is magnetized in the radial direction of the rotating drum 44, and the front surface 45 b of the magnetic pole 45 a (N pole or S pole) of each magnet 45 faces outward and in the central direction in the radial direction of the rotating drum 44. Yes. Moreover, each magnet 45 is magnetized in the opposite direction to the adjacent magnet 45.

  On the other hand, as shown in FIG. 1A and FIG. 3, the electromagnetic clutch 42 is disposed close to the outer side surface of the rotating drum 44. As shown in FIG. A ring-shaped iron core 122 having a groove-shaped cross section composed of a bottom 122a and a pair of side walls 122b and 122c, and a coil 120 wound in the groove 124 of the iron core 122, the opening of the groove 124 is directed to the rotating drum 44 side. ing. Nine outer magnetized pieces 126a and inner magnetized pieces 126b protrude from the outer wall 122b and the inner wall 122c of the iron core 122 at equal intervals, respectively. The outer magnetized piece 126a and the inner magnetized piece 126b face each other on the same radial direction. When the coil 120 is energized, the outer magnetized piece 126a and the inner magnetized piece 126b are magnetized to different magnetic poles N and S. When the direction of the current flowing through the coil 120 is reversed, the magnetic poles of the inner and outer magnetized pieces 126b and 126a are reversed.

  As shown in FIG. 1A and FIG. 3, the magnet 45 provided on the rotary drum 44 is disposed between the inner and outer magnetized pieces 126 b and 126 a provided on the iron core 122 of the electromagnetic clutch 42. The front face 45b of each magnetic pole 45a of the magnet 45 and each magnetized piece 126a, 126b are opposed as close as possible so that a strong magnetic force acts between them.

  The electromagnetic control means 40a does not include a torsion coil spring for biasing the rotary drum 44 to the initial position, and the electromagnetic clutch 42 is movable in the axial direction and the radial direction with respect to the engine case 58. The friction material that is in sliding contact with the rotating drum 44 is not provided.

  Based on FIG. 4, the principle of accelerating / decelerating the rotating drum 44 will be described. However, in FIG. 4, in order to facilitate understanding of the positional relationship between the magnet 45 of the rotating drum 44 and the magnetized pieces 126a and 126b of the electromagnetic clutch 42, the rotating drum 44 and the electromagnetic clutch 42 are connected to the magnet 45 and the magnetized pieces 126a and 126b. This is explained in a flat form at the position. Here, the rotation direction of the rotating drum 44 is the right direction, this right direction is the front, and the opposite left direction is the rear. Further, a magnetic sensor 108 is provided in the vicinity of one front end of the opposing magnetized pieces 126a and 126b (for example, the first). For example, the magnetic sensor 108 outputs an H signal (+1) when one magnetic pole N (or S) approaches, and outputs an L signal (0) when the other magnetic pole S (or N) approaches. Is used. As such a magnetic sensor 108, a Hall element is used. Of course, a magnetic sensor such as a search coil can be used as appropriate.

  First, a case where the rotating drum 44 is accelerated will be described. As shown in FIG. 4A, at time T1, the magnetic pole signal c from the magnetic sensor 108 indicates whether the N pole or the S pole is closest to the magnetic sensor 108. . Thus, since the magnet 45 and the magnetized pieces 126a and 126b are arranged at equal intervals, the positional relationship between the magnetic pole 45a of all the magnets 45 and all the magnetized pieces 126a and 126b can also be known. At time T2 immediately after this, the rotating drum 44 rotates to the position shown in FIG. At this time, in order to accelerate the rotating drum 44, from the time T1, the magnetized piece 126a on the side where the magnetic sensor 108 is provided has the same polarity as the magnetic pole detected by the magnetic pole sensor 108, and at the opposite side. The coil 120 is energized so that the magnetized piece 126b is opposite to the magnetic pole detected by the magnetic pole sensor 108.

  At time T3, the rotary drum 44 rotates to the position shown in FIG. 4C, and the magnetic pole signal c from the magnetic sensor 108 is inverted. At time T4 immediately after this, the rotating drum 44 rotates to the position shown in FIG. At this time, in order to accelerate the rotating drum 44, from the time T3, the magnetized piece 126a on the side where the magnetic sensor 108 is provided has the same polarity as the magnetic pole detected by the magnetic pole sensor 108, and the magnetized piece 126b on the opposite side is placed. The polarity of the current supplied to the coil 120 is reversed so as to be opposite to the magnetic pole detected by the magnetic pole sensor 108.

  Similarly, every time the polarity detected by the magnetic pole signal c from the magnetic sensor 108 is reversed, the direction of the current applied to the coil 120 is reversed, and the magnetized piece 126a on the side where the magnetic sensor 108 is provided is replaced with the magnetic pole sensor 108. The rotation of the rotating drum 44 can be continued by setting the opposite magnetized piece 126b to the same polarity as the magnetic pole detected by the magnetic pole sensor 108.

  When acceleration / deceleration of the rotating drum 44 is not necessary, the supply current to the coil 120 is cut off. Thus, the rotating drum 44 continues to rotate at a constant speed. In order to decelerate the rotating drum 44, a current in the direction opposite to that in the case of accelerating the rotating drum 44 described above may be supplied to the coil 120. In order to decelerate the rotating drum 44, the back electromotive force generated in the coil 120 may be appropriately passed through a resistor or a battery, and the electromagnetic clutch 42 may be an electric brake or a regenerative brake.

  As shown in FIG. 5, the control circuit 100 that controls the current flowing to the coil 120 of the electromagnetic clutch 42 includes a controller (microcomputer) 102, a coil drive circuit 104, a variable voltage power source 106, and a magnetic sensor 108.

  Based on the crank angle signal a and the cam angle signal b sent from the engine 110 and the magnetic pole signal c from the magnetic sensor 108, the controller 102 deviates from the set value of the cam angle phase angle with respect to the crank angle, That is, the drive signal d for accelerating or decelerating the rotary drum 44 is sent to the coil drive circuit 104 so that the phase deviation is eliminated. In order to stop the acceleration / deceleration of the rotating drum 44, the drive signal d may be stopped. Further, the controller 102 sends a power supply control signal e for changing the voltage applied to the coil 120 to the variable voltage power supply 106 in accordance with the absolute value of the phase deviation, thereby enabling finer phase control.

  The coil drive circuit 104 is a semiconductor switch circuit that turns on and off the current supplied to the coil 120 and changes the direction of the current in accordance with the drive signal d sent from the controller 102. The drive signal d includes an H1 signal and an H2 signal for turning the switching transistor 80 on and off. An H (high potential) signal or an L (low potential) signal is output as the H1 signal and the H2 signal, respectively.

  The variable voltage power supply 106 boosts or steps down the output voltage according to the power supply control signal e sent from the controller 102 and sends it to the coil drive circuit 104. In this embodiment, when the absolute value of the phase deviation is small, the output voltage is lowered by performing pulse width modulation (PWM) according to the power supply control signal e. On the other hand, when the absolute value of the phase deviation is large, the output voltage of the variable voltage power supply 106 is appropriately increased by a boosting unit so that a sufficient current flows in the coil 120.

  FIG. 6 shows an example of a wiring diagram of the coil drive circuit 104 and the coil 120. The coil drive circuit 104 is a bridge circuit including four switching transistors 80 and a coil 120. The diode 84 inserted in parallel with the switching transistor 80 is for preventing the back electromotive force generated in the coil 120 from being applied to the switching transistor 80.

  An H1 signal and an H2 signal for turning on / off the switching transistor 80 are sent from the controller 102 as the drive signal d. If the H1 signal is an H signal (H1 = 1) and the H2 signal is an L signal (H2 = 0), a current flows rightward through the coil 120, and the magnetized pieces 126a and 126b can be magnetized. Here, if the H1 signal is inverted to the L signal (H1 = 0) and the H2 signal is inverted to the H signal (H2 = 1), current flows through the coil 120 to the left, and the polarities of the magnetized pieces 126a and 126b are inverted. Can do. In this way, by sending the H1 signal or H2 signal from the controller 102 to the coil drive circuit 104, the direction of the current supplied to the coil 120 is controlled, and the magnetized pieces 126a and 126b are made to have appropriate magnetic poles. 44 can be freely accelerated or decelerated.

  Now, based on FIG. 7, a control procedure performed by the controller 102 of the phase variable device in order to perform acceleration / deceleration control of the rotating drum 44 will be described. When the phase varying device starts operation, first, the process proceeds to step S1, and from the crank angle signal a and cam angle signal b sent from the engine 110, the setting value of the phase angle of the cam angle with respect to the crank angle is set. It is determined whether the deviation, that is, the absolute value of the phase deviation is equal to or greater than a predetermined value K1. When the absolute value of the phase deviation is less than the predetermined value K1, acceleration / deceleration control of the rotating drum 44 is not necessary, so the process proceeds to step S2 to stop the drive signal d to the coil drive circuit 104 (H1 = 0, H2 = 0), power supply to the coil 120 is stopped, the magnetized pieces 126a and 126b are brought into a non-excited state, and the process returns to step S1.

  When the absolute value of the phase deviation is greater than or equal to the predetermined value K1 in step S1, acceleration / deceleration control of the rotating drum 44 is necessary, so the process proceeds to step S3 to determine whether the rotating drum 44 is accelerated or decelerated based on whether the phase deviation is positive or negative. To do. For example, when the phase deviation is negative, it is determined that the rotating drum 44 is decelerated, and steps S4 to S6 are executed. However, depending on the direction of the inner and outer helical splines 32 and 33 (see FIG. 12) of the intermediate member 30, the rotating drum 44 is accelerated in reverse.

  In step S4, the magnetic pole signal c from the magnetic sensor 108 is checked to detect whether the magnet 45 closest to the magnetic sensor 108 is the N pole or the S pole, and a current is supplied to the coil 120. The drive signal d (H1 signal and H2 signal) that indicates the flow direction is determined.

  In step S5, the power control signal e is determined from the absolute value of the phase deviation. When the absolute value of the phase deviation is equal to or greater than the predetermined value K2 (where K2> K1), the variable voltage power supply 106 increases the output voltage from the power supply (battery) voltage according to the absolute value of the phase deviation. When the absolute value is less than the predetermined value K2, the output voltage is lowered from the power supply voltage according to the absolute value of the phase deviation.

  In step S6, the power control signal e is sent to the variable voltage power source 106, and the drive signal d is sent to the coil drive circuit 104 to pass a current through the coil 120 of the electromagnetic clutch 42. Then, it returns to step S1. In this way, steps S1 and S3 to S6 are repeated, and the rotating drum 44 is decelerated, and the phase deviation is decreased until the absolute value of the phase deviation falls within the predetermined value K1.

  If it is determined in step S3 that the phase deviation is positive and the rotating drum 44 is to be accelerated, steps S7 to S9 are executed. In step S7, the drive signal d is determined in the same manner as in step S4 described above. However, in order to increase the speed of the rotary drum 44, the H1 signal and the H2 signal constituting the drive signal d are reversed from those in step S4. is doing. Steps S8 and S9 are the same as steps S5 and S6 described above. After all, when steps S7 to S9 are executed, the direction of the current flowing through the coil 120 is opposite to the case where steps S4 to S6 are executed. Thereafter, the process returns to Step S1, and thereafter, Steps S1, S3, and S7 to S9 are repeated to accelerate the rotating drum 44 and reduce the phase deviation until the absolute value of the phase deviation falls within the predetermined value K1. Go.

  As described above, by executing steps S1 to S9, the phase deviation device can always keep the phase deviation within the predetermined value K1.

  According to the present embodiment, unlike the conventional one shown in FIG. 13, heat is not generated due to friction between the friction material 66 provided on the surface of the electromagnetic clutch 42 and the rotary drum 44, so that it is dispersed in the engine oil. The surface of the friction material is not clogged by the reaction product and insoluble matter of additives such as antioxidants, friction modifiers, and cleaning dispersants, and the friction torque generated in the friction material 66 and the rotating drum 44 does not decrease. This increases the reliability of the phase varying device. In addition, this phase variable device does not require a cooling mechanism for flowing engine oil between the friction material 66 and the rotary drum 44, and the coil driving circuit 104 has a simple configuration because there is only one coil 120. In addition, the number of parts can be reduced, the structure is simple, and it is difficult to break down, has a long life, and can be manufactured at low cost.

  In particular, in this embodiment, the magnet 45 provided on the rotary drum 44 is disposed between the outer magnetized piece 126a and the inner magnetized piece 126b, and the front surface 45b of the magnetic pole 45a of each magnet 45 and the magnetized pieces 126a and 126b are As close as possible. As a result, a strong magnetic force is exerted between the two, so that highly accurate phase variable control can be performed quickly while being lightweight and compact. The reason why the front surface 45b of the magnetic pole 45a and the magnetized pieces 126a and 126b can be as close as possible is that, in the phase variable device, the dimensional tolerance in the radial direction is determined more strictly than the dimensional tolerance in the axial direction. .

  Next, a phase variable device according to a second embodiment of the present invention will be described with reference to FIG. As shown in FIG. 8, in the phase varying device, in the electromagnetic clutch 42, the inner magnetized piece 126b is shorter than the outer magnetized piece 126a, and the side surface 45c of the magnetic pole inside the magnet 45 fixed to the rotating drum 44 is arranged on the inner side. The only difference from the first embodiment is that it is opposed to the tip of the magnetized piece 126b, and the rest is the same as the first embodiment. Of course, contrary to the one shown in FIG. 8, the inner magnetized piece 126b is longer than the outer magnetized piece 126a, and the side surface of the magnetic pole outside the magnet 45 fixed to the rotating drum 44 faces the tip of the outer magnetized piece 126a. You may do it. According to this embodiment, one magnetized piece is made longer than the other magnetized piece, the front surface 45b of one magnetic pole of the magnet 45 fixed to the rotating drum 44 is opposed to the one magnetized piece, and the side surface of the other magnetic pole Since 45c faces the tip of the other magnetized piece, the diameter of the phase varying device can be reduced.

  Next, based on FIG. 9, a phase variable apparatus according to a third embodiment of the present invention will be described. As shown in FIG. 9, in the phase varying device, in the electromagnetic clutch 42, the outer magnetized piece 126 a is provided only on the outer side wall 122 b on the outer peripheral side of the iron core 122, and the inner side wall 122 c on the inner peripheral side is magnetized. The magnet 45 fixed to the rotating drum 44 is not provided with a piece, and the side surfaces of a pair of adjacent ones are attached to each other, and the inner side surface 45c of the magnet 45 is opposed to the tip of the inner wall 122c. I am letting. This is only different from the second embodiment, and the rest is the same as the second embodiment. According to the present embodiment, in the electromagnetic clutch 42, the magnetized piece is not projected from the inner wall 122c, so that the diameter of the phase varying device can be reduced by the amount of overlapping of the inner wall 122c and the magnet 45. There exists an effect that manufacture becomes easy.

  Also in the case of the present embodiment, contrary to the one shown in FIG. 9, in the electromagnetic clutch 42, a magnetized piece is projected only on the inner wall 122c of the iron core 122, and no magnetized piece is provided on the outer wall 122b. May be. A larger torque can be obtained by providing the outer magnetized piece 126a on the outer side wall 122b and accelerating the rotary drum 44 with the outer magnetized piece 126a. However, the inner magnetized piece 126b is provided on the inner side wall 122c, and the inner magnetized piece 126b rotates the drum. Accelerating 44 gives a greater maximum speed. In accordance with the required torque and the maximum speed, it is determined which side of the inner and outer side walls 122c and 122b is provided with the magnetized pieces 126a and 126b.

  Next, a phase variable apparatus according to a fourth embodiment of the present invention will be described with reference to FIG. In this phase varying device, as shown in FIG. 10, the magnet 45 fixed to the rotating drum 44 is magnetized in the axial direction of the rotating drum 44, and the outer side protruded from the iron core 122 of the electromagnetic clutch 42. It is not inserted between the magnetized piece 126a and the inner magnetized piece 126b, and the front surface 45b of the magnetic pole 45a is opposed to the tips of the magnetized pieces 126a and 126b, and arranged in two rows along the circumferential direction of the rotating drum 44. Has been. Except for this, this embodiment is the same as the first embodiment. According to the phase varying device of the present embodiment, since the magnet 45 fixed to the rotating drum 44 is not inserted between the two magnetized pieces 126a and 126b, the shape, size, and size of the magnetized pieces 126a and 126b and the magnet 45 are Strict accuracy is not required for the mounting position, and this phase variable device can be easily manufactured.

  Next, a phase variable apparatus according to a fifth embodiment of the present invention will be described with reference to FIG. In this phase varying device, as shown in FIG. 11, the outer magnetized pieces 126a and the inner magnetized pieces 126b provided on the iron core 122 of the electromagnetic clutch 42 are alternately arranged along the circumferential direction. The front surface 45b of the magnetic pole of the magnet 45 fixed to 44 faces the axial direction of the rotating drum 44, and the front surface 45b of the magnetic pole of the magnet 45 faces the tips of the magnetized pieces 126a and 126b. Except for this, this embodiment is the same as the fourth embodiment. According to the present embodiment, acceleration torque or deceleration torque can be applied to the rotary drum 44 by the two magnetic poles and the three magnetized pieces 126a and 126b, and a small, highly efficient and high torque can be obtained. A phase device is obtained.

  Next, a phase varying apparatus according to a sixth embodiment of the present invention will be described with reference to FIG. In this phase varying device, as shown in FIG. 12, the outer magnetized pieces 126a and the inner magnetized pieces 126b provided in the iron core 122 of the electromagnetic clutch 42 are alternately arranged along the circumferential direction. The magnet 45 fixed to 44 is magnetized along the radial direction of the rotating drum 44, is magnetized in the opposite direction to the adjacent one, and between the magnetized pieces 126a and 126b, Arranged in two rows along the circumferential direction. Except for this, this embodiment is the same as the first embodiment. According to the present embodiment, acceleration torque or deceleration torque can be applied to the rotating drum 44 by the four magnetic poles and the three magnetized pieces 126a and 126b, and a small, highly efficient and high torque can be obtained. A phase device is obtained.

  By the way, the present invention is not limited to the above embodiment, and can be variously modified as follows, for example.

  The number of magnetized pieces 126a and 126b provided on the magnet 45 fixed to the rotating drum 44 and the iron core 122 of the electromagnetic clutch 42 need not be the same as the number of the above-described embodiments, and depends on the required accuracy, torque, cost, etc. May be increased or decreased as appropriate.

  In each of the above embodiments, the output voltage of the variable voltage power supply 106 is controlled according to the phase deviation. However, there is no practical problem even if the power supply voltage is not controlled unless particularly high accuracy is required.

  Furthermore, in each of the above embodiments, one coil 120 is wound around the iron core 122. However, in order to switch the inner and outer magnetized pieces 126b and 126a between the N pole and the S pole at high speed, a plurality of coils 120 are connected in parallel. The combined inductance of all the coils may be reduced.

It is a figure explaining the schematic structure of the phase variable apparatus which concerns on 1st Example of this invention. It is a perspective view of the electromagnetic clutch of this phase variable apparatus. FIG. 3A is a cross-sectional view taken along line III-III in FIG. It is a figure explaining the principle which accelerates / decelerates the rotating drum of this phase variable apparatus. It is a block diagram of the control circuit of the electromagnetic clutch in this phase variable apparatus. It is a wiring diagram of the coil drive circuit and each coil in this phase variable apparatus. It is a flowchart explaining operation | movement of this phase variable apparatus. It is a figure explaining the phase variable apparatus of 2nd Example of this invention. It is a figure explaining the phase variable apparatus of 3rd Example of this invention. It is a figure explaining the phase variable apparatus of 4th Example of this invention. It is a figure explaining the phase variable apparatus of 5th Example of this invention. It is a figure explaining the phase variable apparatus of 6th Example of this invention. It is a figure explaining the structure of the conventional phase variable apparatus.

Explanation of symbols

2 Camshaft 10 Outer cylinder 12 Sprocket 20 Inner cylinder 30 Intermediate member 42 Electromagnetic clutch 44 Rotating drum 45 Magnet 102 Controller 104 Coil drive circuit 108 Magnetic sensor 120 Coil 122 Iron core 122b, 122c Side wall 124 Groove 126a, 126b Magnetized piece (magnetization) Part)
a Crank angle signal b Cam angle signal c Magnetic signal d Drive signal

Claims (8)

An outer cylinder part to which rotation of the crankshaft of the engine is transmitted, an inner cylinder part connected to a camshaft that is rotatable relative to the outer cylinder part and opens and closes an intake valve or an exhaust valve of the engine, the outer cylinder part, An intermediate member meshed with a helical spline on the inner cylinder portion, and moving the intermediate member in the axial direction to cause relative rotation between the outer cylinder portion and the inner cylinder portion, thereby In the engine phase varying device that changes the opening and closing timing of the valve,
A rotating drum threadably engaged with the intermediate member, a plurality of magnets fixed to the rotating drum at predetermined intervals along the circumferential direction of the rotating drum, and a plurality of magnetized portions that exert a magnetic force on the magnet along the circumferential direction An electromagnetic clutch including an iron core provided at a predetermined interval and a coil wound around the iron core, a coil drive circuit for supplying power to the coil when the magnetizing portion is magnetized, and a magnetic signal by detecting the approach of the magnet A phase deviation which is a deviation from a set value of the phase between the cam angle and the crank angle is obtained from a crank angle signal and a cam angle signal sent from the engine and a magnetic sensor for generating Based on the magnetic signal, when the rotary drum is accelerated, decelerated or rotated at a constant speed, a direction of current supplied to the coil and a drive signal indicating ON / OFF are sent to the coil drive circuit. And a controller,
The engine phase variable device according to claim 1, wherein the magnet is magnetized along a radial direction of the rotary drum, and adjacent magnets are magnetized in opposite directions.   The iron core is an annular body having a U-shaped cross section with a groove, the coil is disposed in the groove, and the magnetized portions are located on the outer peripheral side and the inner peripheral side on the same radial direction of the iron core and face each other. The engine phase varying device according to claim 1, wherein the magnet is arranged between the outer magnetized piece and the inner magnetized piece.   The iron core is an annular body having a U-shaped cross section with a groove, the coil is disposed in the groove, and the magnetized portions are located on the outer peripheral side and the inner peripheral side on the same radial direction of the iron core and face each other. The outer magnetized piece and the inner magnetized piece, one magnetized piece of both magnetized pieces is longer than the other magnetized piece, the front of one magnetic pole of the magnet is opposed to the side surface of the one magnetized piece, and the magnet 2. The phase varying device for an engine according to claim 1, wherein a side surface of the other magnetic pole is opposed to a tip surface of the other magnetized piece.   The iron core is an annular body having a U-shaped cross section with a groove, the coil is disposed in the groove, and the magnetized portions are outer magnetized pieces alternately disposed on the outer peripheral side and the inner peripheral side of the iron core, and 2. The engine according to claim 1, comprising an inner magnetized piece, wherein the magnet extends along a circumferential direction of a rotary drum, and the magnet is arranged in two rows between the outer magnetized piece and the inner magnetized piece. Phase variable device.   The iron core is an annular body having a U-shaped cross section with a groove, the coil is disposed in the groove, and the magnetized portion is a magnetized piece disposed on the outer peripheral side or the inner peripheral side of the iron core, 2. The engine phase varying device according to claim 1, wherein the pair of magnets have side surfaces bonded to each other, and the front surface of the magnetic pole is opposed to the side surface of the magnetized piece. An outer cylinder part to which rotation of the crankshaft of the engine is transmitted, an inner cylinder part connected to a camshaft that is rotatable relative to the outer cylinder part and opens and closes an intake valve or an exhaust valve of the engine, the outer cylinder part, An intermediate member meshed with a helical spline on the inner cylinder portion, and moving the intermediate member in the axial direction to cause relative rotation between the outer cylinder portion and the inner cylinder portion, thereby In the engine phase varying device that changes the opening and closing timing of the valve,
A rotating drum threadably engaged with the intermediate member, a plurality of magnets fixed to the rotating drum at predetermined intervals along the circumferential direction of the rotating drum, and a plurality of magnetized portions that exert a magnetic force on the magnet along the circumferential direction An electromagnetic clutch including an iron core provided at a predetermined interval and a coil wound around the iron core, a coil drive circuit for supplying power to the coil when the magnetizing portion is magnetized, and a magnetic signal by detecting the approach of the magnet A phase deviation that is a deviation from a set value of the phase between the cam angle and the crank angle is obtained from a crank angle signal and a cam angle signal sent from the engine and a magnetic sensor that generates Based on the magnetic signal, when the rotary drum is accelerated, decelerated or rotated at a constant speed, a direction of current supplied to the coil and a drive signal for instructing ON / OFF are sent to the coil drive circuit. And a controller,
The iron core is an annular body having a U-shaped cross section with a groove, the coil is disposed in the groove, the magnet is magnetized along the axial direction of the rotating drum, and adjacent magnets are opposite to each other. A phase varying device for an engine characterized by being magnetized.   The magnetized portion is composed of an outer magnetized piece and an inner magnetized piece alternately arranged on the outer peripheral side and the inner peripheral side of the iron core, and the magnet is opposed to the tips of the outer magnetized piece and the inner magnetized piece. The engine phase varying apparatus according to claim 6.   The magnetized portion is composed of an outer magnetized piece and an inner magnetized piece located on the outer peripheral side and the inner peripheral side of the iron core in the same radial direction and facing each other, and the magnet is opposed to the tip of the outer magnetized piece or the inner magnetized piece. The engine phase varying device according to claim 6, wherein the engine phase varying device is arranged in two rows along a circumferential direction of the rotating drum.

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