HK1158288B - Cam shaft phase variable device in engine for automobile - Google Patents

Description

Camshaft phase variable device in automobile engine

Technical Field

The present invention is a phase varying device in an automobile engine, which is provided with a rotational operation force applying mechanism for rotating a rotary drum disposed coaxially with a camshaft in either a forward or reverse direction, and which varies the opening/closing timing of a valve by varying the rotational phase of a crankshaft and the camshaft in either an advance angle direction or a retard angle direction in accordance with the rotational direction.

Background

As such a conventional technique, there is a valve timing control device shown in patent document 1 below. The device of patent document 1 changes the timing of opening and closing a valve of an internal combustion engine that is opened and closed by a cam by changing the assembly angle of a camshaft 1 with respect to a drive plate 2 driven by a driving force received from a crankshaft of the engine in an advance angle direction (the rotation direction of the drive plate 2) or a retard angle direction (the direction opposite to the rotation direction of the drive plate 2).

In the device of patent document 1, a spacer 8 and a lever shaft 13 are integrally fixed, and a drive plate 2 is assembled to the spacer 8 so as to be rotatable relative thereto. One end of a link arm 14 is rotatably attached to three rods 12 of a lever shaft 13, and a movable operation member 11 rotatably attached to the other end of the link arm 14 is slid in the radial direction on a substantially radial guide groove 10 in front of the drive plate 2. The cam shaft 1 is rotated around the pin 16 by the link arm 14 to change in the advance angle direction if the movable operation member 11 slides radially inward with respect to the drive plate 2, and is reversely rotated by the link arm 14 to return in the retard angle direction if the movable operation member 11 slides radially outward.

In front of the movable operation member 11, a guide plate 24 (rotary drum) is disposed which is assembled to be relatively rotatable with respect to the camshaft 1 (the lever shaft 13) and the drive plate 2. The ball 22 is rotatably held between a recessed portion 21 provided on the front surface of the movable operation member 11 and a spiral groove 28 (spiral guide) provided on the rear surface of the guide plate 24. The movable operation member 11 is rotated along the spiral groove 28 in accordance with the relative rotation direction of the guide plate 24 with respect to the drive plate 2 by the balls 22, and slides radially inward or outward on the substantially radial guide grooves 10.

The guide plate 24 is relatively rotated to the retarded angle side with respect to the drive plate 2 by the braking force of the first electromagnetic brake 26, and is relatively rotated to the advanced angle side with respect to the drive plate 2 by the following planetary gear mechanism 25 (counter rotation mechanism) operated by the second electromagnetic brake 27.

The planetary gear mechanism 25 (counter rotation mechanism) is configured to have a sun gear 30 and an internal gear 31 in front of the guide plate 24 on the rear face of a brake flange 34 assembled relatively rotatably with respect to the camshaft 1 (spindle 13) and on the front face of the guide plate, respectively, and to have a plurality of planetary gears 33 meshing between the sun gear 30 and the internal gear 31 while being rotatably supported with respect to a carrier plate 32 fixed to the spindle 13. If the brake flange 34 is braked by the second electromagnetic brake 27, the planetary gear 33 rotates, the internal gear 31 accelerates in the advance direction, and the guide plate 24 rotates relative to the drive plate 2 toward the advance side.

That is, the device of patent document 1 is a device in which a guide plate 24 is relatively rotated with respect to a drive plate 2 by a pair of electromagnetic brakes (26, 27) and a planetary gear mechanism 25 (counter rotation mechanism), and an assembly angle of a camshaft 1 and a crankshaft (drive plate 2) is changed in accordance with the relative rotation direction.

Patent document 1: japanese patent laid-open No. 2006-77779

Disclosure of Invention

Problems to be solved by the invention

In the device of patent document 1, there is a problem in that the manufacturing cost of the counter-rotation mechanism of the rotary drum (guide plate 24) is increased and the operating sound is increased. That is, since the planetary gear mechanism 25 employs a plurality of gears including the sun gear 30, the ring gear 31, and the plurality of planetary gears 33, there is a problem in that the manufacturing cost is increased when forming the plurality of tooth portions with high accuracy. On the other hand, the gears generate tooth hitting noise because the meshing teeth collide with each other during operation. Therefore, the planetary gear mechanism 25 has a problem in that the operating sound becomes large when the valve timing is changed because a plurality of gears are used.

In order to solve the above-described problems, the inventors of the present invention invented a phase variable device in an automobile engine including a counter-rotating mechanism of a rotary drum (guide plate 24) which is inexpensive to manufacture and has quiet operating sound when the valve timing is changed, and applied for a patent (international application No.: PCT/JP2008/57857, title of the invention: a phase variable device in an automobile engine, hereinafter referred to as "prior application 1").

The counter rotation mechanism of the drum in the prior application 1 includes first and second control rotating bodies (45, 57) which are attached to a center shaft 42 integrated with a cam shaft 40 so as to be relatively rotatable and are respectively braked by first and second electromagnetic clutches (44, 60), and a second intermediate rotating body 56 is fixed between the first and second control rotating bodies (45, 57) so as not to be relatively rotatable with respect to the center shaft 42.

The second control rotating body 57 includes a curved second guide groove 62 that is reduced in diameter in the lead direction (clockwise direction viewed from the second electromagnetic clutch 60 side as the rotation direction of the driving rotating body 71) on the surface facing the second intermediate rotating body 56, the first control rotating body 45 includes a curved first guide groove 61 that is reduced in diameter in the lag direction (counterclockwise direction as the reverse direction to the rotation direction of the driving rotating body 71) on the surface facing the second intermediate rotating body 56, and the second intermediate rotating body 56 includes a substantially radial guide groove 63 that penetrates in the center axis direction. In each of the guide grooves (61-63), a slide pin 64 is inserted and slidably disposed in the direction of each guide groove.

The second control rotating body 57 is braked by the second electromagnetic clutch 60, and if it rotates in a retarded angle direction relative to the intermediate rotating body 56, it moves to the inside in the radial direction of the rotating body by the displacement of the slide pin 64 along the second guide groove 62 and the substantially radial guide groove 63. The first control rotor 45 receives a torque in the advance angle direction from the slide pin 64 moving inward via the first guide groove 61, and rotates relative to the second intermediate rotor 56 in the advance angle direction, thereby changing the assembly angle of the camshaft 40 (central shaft 42) to the advance angle side with respect to the crankshaft (driving rotor 41). On the other hand, if the first control rotating body 45 is braked by the first electromagnetic clutch 44, it rotates in the retarded angle direction relative to the intermediate rotating body 56, and the assembly angle is changed to the retarded angle side.

In the counter-rotation mechanism of the first control rotating body 45 (drum), the rotating bodies (56, 57), the slide pin 64, and the guide grooves (61 to 63) are formed in a simple shape such as a circular shape, and therefore, the machining is easy, and the manufacturing cost is low. Since the slide pin 64 is normally in sliding contact with each guide groove (61-63) and is quietly displaced, the operating sound when the valve timing is changed is quiet.

On the other hand, the assembly angle of the camshaft 40 with respect to the crankshaft (the driving rotary body 41) can be increased by making the length of the first guide groove 61 longer in the circumferential direction, thereby increasing the displacement width. On the other hand, the torque in the advance angle direction received by the first control rotating body 45 from the slide pin 64 sliding inward along the first guide groove 61 is smaller as the length of the first guide groove 61 is made longer in the circumferential direction due to an increase in the inclination of the first guide groove 61 with respect to the substantially radial guide groove 63 (an increase in friction).

In the counter rotation mechanism of the first control rotating body 45 (rotary drum), it is desirable that the displacement width of the camshaft 40 with respect to the assembly angle of the crankshaft is as large as possible while maintaining the rotational torque of the first rotating body 45 given by the braking of the second control rotating body 57.

The present invention provides a phase variable device for an engine, which maintains the advantages (low manufacturing cost and quietness) of the prior application 1, and further includes a counter-rotation mechanism for a rotary drum capable of increasing the displacement width of the assembly angle of a crankshaft and a camshaft without reducing the rotational torque of a first control rotating body generated by a second control rotating body.

Means for solving the problems

In order to achieve the above object, a first aspect of the present invention is a phase variable device for an engine, in which a driving rotating body rotationally driven by a crankshaft, a first intermediate rotating body integrated with a camshaft, and a first control rotating body receiving a rotational torque from a rotational operation force applying mechanism are disposed on a same rotational center axis so as to be rotatable relative to each other, and a phase angle between the camshaft and the driving rotating body is changed in accordance with a relative rotational direction of the first control rotating body with respect to the first intermediate rotating body and the driving rotating body, the phase variable device comprising: a first brake mechanism for relatively rotating the first control rotor with respect to the first intermediate rotor and the drive rotor; a second intermediate rotating body integrated with the camshaft and having a substantially radial guide groove extending in a radial direction and penetrating in an axial direction; a second control rotating body which is disposed coaxially with and relatively rotatable to the first control rotating body and the second intermediate rotating body, and which is relatively rotated by a second brake mechanism; a first eccentric rotation mechanism which rotates eccentrically around the rotation center shaft in conjunction with the first control rotation body; a second eccentric rotation mechanism which rotates eccentrically around the rotation center shaft in conjunction with the second control rotation body; and a connecting mechanism engaged with the substantially radial guide groove in a displaceable manner and relatively rotatably connecting the first and second eccentric rotating mechanisms. When one of the first control rotating body and the second control rotating body is rotated, the other is relatively rotated.

In the initial state, the first control rotating body rotates integrally with the driving rotating body that receives the driving force from the first intermediate rotating body integrated with the camshaft and the crankshaft. The first control rotating body rotates in a retarded angle direction relative to the driving rotating body and the first intermediate rotating body when receiving a braking force from the first braking mechanism, and rotates in an advanced angle direction relative to the driving rotating body and the first intermediate rotating body opposite to the first braking mechanism when the second control rotating body is braked by the second braking mechanism. The phase angle of the first intermediate rotating body (on the camshaft side) relative to the driving rotating body (on the crankshaft side) changes in either the advance angle direction (the rotation direction of the driving rotating body, hereinafter the same) or the retard angle direction (the direction opposite to the rotation direction of the driving rotating body, hereinafter the same) depending on the relative rotation direction of the first control rotating body.

On the other hand, the first eccentric rotation mechanism rotates together with the first control rotation body, and the second control rotation body and the second eccentric rotation mechanism are simultaneously rotated relative to the first control rotation body and the second intermediate rotation body integrated with the camshaft by the second brake mechanism. When either one of the first and second eccentric rotating mechanisms rotates, the coupling mechanism displaces the substantially radial guide groove of the second rotating body in the radial direction and rotates the other in the reverse direction. That is, if the second control rotating body is braked, the first control rotating body is rotated in the opposite direction to the direction in which the first and second eccentric rotating mechanisms brake the first control rotating body.

When a four-bar mechanism is temporarily formed, which couples the eccentric point of the rotation center axis from the coupling mechanism and the first eccentric rotation mechanism, the eccentric point of the coupling mechanism and the second eccentric rotation mechanism, the eccentric point and the rotation center axis of the first eccentric rotation mechanism, and the eccentric point and the rotation center axis of the second eccentric rotation mechanism, respectively, the coupling mechanism is reciprocated in the substantially radial guide groove in the same operation as one of the coupling portions of the four-bar mechanism. Similarly, if the eccentric points of the first and second eccentric rotation mechanisms corresponding to the connecting portions of the links are reciprocally swung, the eccentric points rotate in opposite directions and smoothly around the respective rotation centers. Therefore, if one of the first and second control rotating bodies rotating together with the first and second eccentric rotating mechanisms rotates, the other rotates smoothly in the reverse direction.

On the other hand, the displacement width of the camshaft with respect to the assembly angle of the crankshaft can be increased by making the substantially radial guide groove longer or increasing the reciprocating rotation range of the first and second eccentric rotation mechanisms.

Further, since the control rotating bodies, the second intermediate rotating body, the eccentric rotating mechanisms, and the connecting mechanism have a simple structure mainly including a circular shape, the processing is easy. When the phase angle between the driving rotor and the first intermediate rotor is changed, the coupling mechanism is normally in sliding contact with each guide groove and is quietly displaced.

In order to achieve the above object, a second aspect is the phase variable device of the engine according to the first aspect, the first eccentric rotation mechanism includes a first eccentric circular hole formed in the first control rotating body, and a first ring member having an outer periphery engaged with an inner periphery of the first eccentric circular hole in a slidable manner, the second eccentric rotation mechanism includes a second eccentric circular hole formed in the second control rotating body, and a second ring member having an outer periphery engaged with an inner periphery of the second eccentric circular hole in a slidable manner, the coupling mechanism includes first and second engaging holes formed in the first and second ring members, respectively, and a coupling member penetrating the substantially radial guide groove, the first and second engaging holes are inserted into both ends of the first ring member, and the first ring member and the second ring member are disposed so that the center thereof is located between the extending lines of the substantially radial guide grooves.

The first and second ring members eccentrically rotate around the rotation center axis of each control rotating body together with the first and second control rotating bodies and slide in the first and second eccentric circular holes. When either one of the first and second control rotating bodies is braked, the ring member of the braked control rotating body slides in the eccentric circular hole to swing the coupling member along the substantially radial guide groove, and the other control rotating body is rotated in the reverse direction via the other coupled ring member. The first and second control rotating bodies are rotated in opposite directions smoothly and reversely with respect to each other by the same operation as the connecting portion of the four-bar mechanism, which is performed by the connecting member displaced in the substantially radial guide groove, at each eccentric point of the first ring member (first eccentric circular hole) and the second ring member (second eccentric circular hole) sliding in the circular holes rotated eccentrically in opposite directions with respect to each other. Further, the ring member mainly having a circular shape, the eccentric circular hole, and the connecting member are easily processed and operate quietly.

In order to achieve the above object, a third aspect is the phase variable device according to the second aspect, wherein the first eccentric circular hole is formed such that an eccentric amount from a rotation central axis of the first control rotating body to a central axis of the first eccentric circular hole is larger than an eccentric amount from a rotation central axis of the second control rotating body to a central axis of the second eccentric circular hole.

In general, when the second brake mechanism is disposed coaxially with and inside the first brake mechanism, the braking radius of the second control rotating body by the second brake mechanism is smaller than the braking radius of the first control rotating body by the first brake mechanism. Therefore, if the second brake mechanism does not generate a larger braking force than the first brake mechanism, the reverse rotation torque of the same magnitude as that of the first brake mechanism cannot be applied to the first control rotating body, so the operating speed of the first control rotating body differs in the advance angle direction and the retard angle direction due to the torque difference.

In the phase variable device according to the third aspect, the eccentric amount of the first ring member (the distance from the center axis of the first ring member to the rotation center axis of the first control rotating body, hereinafter the same) is larger than the eccentric amount of the second ring member (the distance from the center axis of the second ring member to the rotation center axis of the second control rotating body, hereinafter the same), and the moving distance of the center of the first ring member when the second ring member rotates is larger than the moving distance of the center of the second ring member. Therefore, in the phase variable device according to the third aspect, since the reverse rotation torque of the same magnitude as that of the first brake mechanism can be applied to the first control rotating body while reducing the braking torque of the second control rotating body generated by the second brake mechanism, the relative rotation speed of the first control rotating body is matched in the advance angle direction and the retard angle direction.

A fourth aspect is the phase variable device of the engine according to the second or third aspect, wherein at least one of the first and second ring members is a C-shaped ring member.

When the ring member is formed in the C-shape, the notch portion of the C-shape serves as an escape portion away from the central axis, so that the eccentric amounts of the first ring member and the second ring member can be increased.

A fifth technical means is the phase variable device of an engine as defined in any one of the second to fourth technical means, wherein the substantially radial guide groove is formed to have a length such that the second ring member can rotate 360 ° or more in the second eccentric circular hole.

When the second control rotating body rotates 360 °, the shaft-like member reciprocates from one end to the other end of the substantially radial guide groove, and performs both relative rotation in the advance angle direction and relative rotation in the retard angle direction with respect to the driving rotating body. That is, the second brake mechanism and the second control rotating body rotate the first control rotating body relatively in both the advance angle and the retard angle directions independently, and change the assembly angle of the crankshaft and the camshaft to either the advance angle side or the retard angle side.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the phase variable device of the engine in the first and second aspects, the rotational operation force applying mechanism of the first control rotating body can increase the displacement width of the assembly angle of the crankshaft and the camshaft without reducing the relative rotational torque of the first control rotating body by braking of the second control rotating body. Further, since the rotating operation force applying mechanism is mainly formed in a circular shape, it can be easily and inexpensively manufactured and the operating sound when the phase angle is changed is reduced.

According to the phase variable device of the engine of the third aspect, even if the second brake mechanism is disposed inside the first brake mechanism and there is a fear that the braking torque becomes insufficient, the phase variable device of the engine can exhibit the same braking performance as the first brake mechanism.

According to the phase variable device for an engine pertaining to the fourth aspect, the degree of freedom in setting the amount of eccentricity of the first ring and the second ring is improved, so the displacement width of the assembly angle of the crankshaft and the camshaft can be further increased.

According to the phase variable device for an engine of the fifth aspect, since the assembly angle of the crankshaft and the camshaft can be changed in both the advance angle direction and the retard angle direction by the single control rotating body and the single braking mechanism, the assembly angle of the crankshaft and the camshaft can be changed by the other braking mechanism when one of the two braking mechanisms fails, and a fail-safe function can be provided.

Detailed Description

Embodiments of the present invention will be described below with reference to examples 1 to 3.

Fig. 1 is an exploded perspective view of a phase variable device in an automobile engine as a first embodiment of the present invention, viewed from the front, fig. 2 is a front view of the device, fig. 3 is a sectional view a-a of fig. 2 as an axial sectional view of the device, fig. 4 is a sectional view in a radial direction of the device before phase shift, (a) is a sectional view B-B of fig. 3, (B) is a sectional view C-C of fig. 3, (C) is a sectional view D-D of fig. 3, fig. 5 is a view showing a state after phase shift of each sectional view of fig. 4, fig. 6 is a sectional view in a radial direction of the device before phase shift, (a) is a sectional view E-E of fig. 3, (B) is a sectional view F-F of fig. 3, (C) is a sectional view G-G of fig. 3, and fig. 7 is a view showing a state after phase shift of each sectional view of fig. 6, fig. 8 is a G-G sectional view of fig. 3 showing a first ring member and a first eccentric circular hole in the second embodiment of the phase variable device, fig. 9(a) is an E-E sectional view of fig. 3 showing a second ring member and a second eccentric circular hole in the third embodiment of the phase variable device, and (b) is a G-G sectional view of fig. 3 showing the first ring member and the first eccentric circular hole in the third embodiment.

The phase variable device of the engine according to the embodiment is used in an integrated form for being incorporated in an engine, and transmits the rotation of a crankshaft to a camshaft in synchronization with the rotation of the crankshaft to open and close intake and exhaust valves, and changes the opening and closing timings of the intake and exhaust valves of the engine according to the operating state such as the load and the rotation speed of the engine.

The following describes the structure of the device of the first embodiment (for the sake of convenience of description, the direction of the second electromagnetic clutch 90 described later is defined as the front side, and the direction of the sprocket 71a is defined as the rear side), the same rotation center axis L1 includes a driving rotor 71 that receives a driving force from a crankshaft (not shown) of the engine to rotate, a center axis 72 that is fixed to a camshaft (not shown) and supports the driving rotor 71 in a relatively rotatable manner, a first intermediate rotor 73 that is fixed to the center axis 72 in a non-rotatable manner in front of the driving rotor 71 and rotates relative to the driving rotor 71, a first control rotor 74 that is supported on an outer peripheral surface of the driving rotor 71 and rotates relative to the center axis 72 in a non-contact manner, and a first electromagnetic clutch 75 that is fixed to an engine case (not shown) and brakes rotation of the first control rotor 74.

The first control rotating body 74 includes an eccentric circular cam 76 (see fig. 3 and 4 a) that is integrally formed with the rear surface and eccentrically rotates around a center axis L1. The intermediate rotating body 73 has a cam guide 77 with which the eccentric circular cam 76 engages on the front surface, and reciprocates in a direction orthogonal to the central axis L1 and the wall surface direction of the cam guide 77 when the eccentric circular cam 76 rotates.

The center shaft 72 is integrated with the hole 72a in a state where the hole and the tip end of the camshaft, not shown, are not rotatable relative to each other. The driving rotator 71 is configured by coupling the sprocket 71a and the driving cylinder 71b to a plurality of coupling pins 78. The driving rotator 71 is supported so that a hole 71c of the sprocket 71a and a cylindrical portion 72c provided behind a flange 72b of the center shaft 72 are rotatable relative to each other. The drive cylinder 71b is formed in a bottomed cylindrical shape, and a pair of curved guide grooves 79 are formed in the bottom portion thereof in the substantially circumferential direction around the rotation center axis L1. As shown in fig. 4, the guide groove 79 is composed of a guide groove 79a whose diameter is reduced in the rotational direction D1 of the driving rotor 71 (clockwise direction as viewed from the front of the apparatus, the same applies hereinafter) and a guide groove 79b formed symmetrically to the guide groove 79a with the rotational center axis therebetween. The diameter of the guide groove 79a may be reduced in a counterclockwise direction D2 described later.

The first intermediate rotating body 73 is formed in a disk shape, and includes a cam guide 77 on the front surface, which is a pair of wall surfaces perpendicular to the central axis L1 and with which the eccentric circular cam 76 engages. The bottom surface of the cam guide 77 extends in a direction perpendicular to the wall surface of the cam guide 77 and the center axis L1, and is provided with a rectangular hole 80 penetrating in the direction of the center axis L1. The first intermediate rotating body 73 is fixed in a state of being relatively non-rotatable with respect to the central shaft 72 by engaging the flat engaging surface 72d with the rectangular hole 80, and is slidably supported by the central shaft 72 in the direction in which the rectangular hole 80 extends.

The first intermediate rotating body 73, the first control rotating body 74, and the eccentric circular cam 76 are disposed inside the driving cylinder 71 b. The first control rotating body 74 includes a through circular hole 74a at the center thereof, through which the cylindrical portion 72e of the center shaft 72 is inserted in a non-contact state. An eccentric circular cam 76 is integrally formed on the rear face of the first control rotating body 74 with its center axis L2 eccentric from the rotation center axis L1 by only the distance d 0. The first control rotor 74 is formed in a disc shape, and its outer peripheral surface 74b is supported by a stepped inner peripheral surface 71d of the substantially inscribed drive cylinder 71 b.

The first control rotating body 74 is normally supported by the driving cylinder 71b through the circular through hole 74a without contacting the cylindrical portion 72e of the center shaft 72. If the camshaft receives a relative rotational torque due to interference, the first control rotating body 74 receives a force from the cam guide 77 in a direction orthogonal to the rotational center axis L1. At this time, the first control rotor 74 moves in the direction perpendicular to L1, and the outer peripheral surface 74b comes into contact with the inner peripheral surface 71d of the rotor cylindrical body 71 b. Therefore, the phase variable device according to the first embodiment has a self-locking function of preventing the occurrence of the phase angle deviation due to the disturbance by the frictional force of the contact surface. Since the through circular hole 74a has a sufficient clearance from the cylindrical portion 72e of the center shaft 72, the first control rotating body 74 does not contact the cylindrical portion 72e even if it moves in the direction perpendicular to L1 during self-locking. Therefore, the self-locking function described above reliably acts between the outer peripheral surface 74b and the inner peripheral surface 71 d. The outer shape of the eccentric circular cam 76 is not limited to the circular shape as in the present embodiment, and may be a cam shape having a special peripheral edge.

The first intermediate rotating body 73 includes a pair of shaft-like members 81 projecting rearward from the pair of engaging holes 73 a. The shaft-like member 81 is formed by inserting a thin circular shaft 81a into a hollow thick circular shaft 81 b. The front end thin circular shaft 81a is engaged with the engagement hole 73a, and the rear end hollow thick circular shaft 81b is engaged with a pair of guide grooves (79a, 79b) as substantially circumferential grooves formed in the drive cylinder 71b in a displaceable manner.

A first electromagnetic clutch 75 having a friction member 82 disposed on the rear side is disposed in front of the first control rotating body 74, and the electromagnetic clutch 75 applies current to the coil 75a to bring the attraction surface 74c of the first control rotating body 74 into sliding contact with the friction member 82, thereby braking the rotation of the first control rotating body 74.

Further, in front of the first control rotating body 74, a first ring member 83, a second intermediate rotating body 84, a shaft-like member (coupling member) 85, a second ring member 86, a second control rotating body 87, a spacer 88, a retainer 89, and a second electromagnetic clutch 90 are disposed, respectively. Each member from the reference numerals 83 to 90 constitutes the rotational operation force applying mechanism of claim 1 of the present application together with the first electromagnetic clutch 90.

The first control rotating body 74 is formed in a bottomed cylindrical shape, and includes a stepped first eccentric circular hole 74d whose center axis L2 is eccentric from the rotation center axis L1 by a distance d1 on the front surface of the bottom thereof. The first ring member 83 is slidably engaged with the eccentric circular hole 74 d. The first ring member 83 has a first engaging hole 83a opened in the front surface.

The second intermediate rotating body 84 has a square hole 84a at the center thereof and a substantially radial guide groove 84b extending in the radial direction of the second intermediate rotating body 84 on the outer side thereof. The second intermediate rotating body 84 is fixed to the center shaft 72 in a non-rotatable state by engaging with the second flat engaging surfaces (72f, 72g) of the center shaft 72 through the square holes 84 a.

The second control rotor 87 is supported rotatably with respect to the central shaft 72 by a circular hole 87a formed in the center thereof and inserted through a small cylindrical portion 72h at the tip end of the central shaft 72. The second control rotating body 87 has a stepped eccentric circular hole 87b in which the center axis L3 is eccentric from the rotation center axis L1 by the distance d1 in the same manner as the first eccentric circular hole 74d in the rear surface. The second ring member 86 is slidably engaged with the eccentric circular hole 87 b. The second ring member 86 has a second engaging hole 86a opened in the rear surface.

The shaft-like member 85 is configured by inserting (fitting) a hollow thick circular shaft 85b into the center of the thin circular shaft 85 a. Both ends of the thin circular shaft 85a are slidably engaged with the first and second engaging holes (83a, 86a), and the hollow thick circular shaft 85b is engaged in a state of being displaceable in the radial direction of the second intermediate rotating body 84 along the substantially radial guide groove 84 b.

The first and second ring members (83, 86) have center axes (L2, L3) that sandwich an extension line L4 of a substantially radial guide groove 84b that is orthogonal to the rotation center axis L1 of the first and second control rotating bodies (74, 87), and are arranged with first and second eccentric circular holes (74d, 87b) so as to be substantially symmetrical about the extension line L4.

A washer 88 is disposed in a stepped circular hole 87c in the front surface of the second control rotor 87, and a retainer 89 is inserted into a small cylindrical portion 72h of the center shaft 72 projecting forward from the circular hole 87 a. The structural components from the retainer 89 to the drive cylinder 71b are fixed to a camshaft (not shown) by screwing by inserting bolts (not shown) from the front into central holes thereof. The second electromagnetic clutch 90 is disposed to face the front surface of the second control rotating body 87 in a state of being fixed to an engine case, not shown. The second electromagnetic clutch 90, when the coil 90a is energized, attracts the attracting surface 87d of the front surface of the second control rotating body 87 to slide on the friction member 91, thereby braking the rotation of the second control rotating body 87.

Further, if the second control rotating body 87 is disposed inside the coil 75a, the attracting surface 87d of the second control rotating body is magnetized when the first electromagnetic clutch 75 is operated, and the operation becomes unstable, and therefore, it is desirable to dispose the attracting surface in the same plane as the attracting surface 74c of the first control rotating body 74 as shown in fig. 3.

The shaft-like members (81, 85) may be in the form of bearings, for example, and may roll inside the grooves when displaced in the guide grooves 79 and the substantially radial guide grooves 84b, respectively, so that the shaft-like members (81, 85) may be replaced with balls. In this case, the shaft-like members (81, 85) have reduced frictional resistance during displacement, so that displacement is facilitated, and the power consumption of each electromagnetic clutch can be reduced.

Further, the second intermediate rotating body 84 is preferably formed of a non-magnetic body. If the second intermediate rotating body 84 is formed of a non-magnetic material, the problem that the magnetic force of one of the control rotating bodies (74, 87) for attracting is transmitted to the other control rotating body through the second intermediate rotating body 84 and attracted together can be eliminated.

The operation when changing the phase angle between the camshaft (not shown) and the driving rotor 71 will be described below with reference to fig. 1 and 4 to 7. In an initial state where the phase angle is not changed, if the driving rotor 71 is rotated in the clockwise direction D1 by a crankshaft (not shown) when viewed from the front of the apparatus, the first intermediate rotor 73, the first control rotor 74 (eccentric circular cam 76), the second intermediate rotor 84, and the second control rotor 87 rotate in the clockwise direction D1 integrally with the driving rotor 71.

When the phase angle of the camshaft relative to the driving rotary member 71 is changed in the advance angle direction (clockwise direction D1 when viewed from the front of the apparatus, the same applies hereinafter), the second control rotary member 87 is braked by the second electromagnetic clutch 90. When the second electromagnetic clutch is actuated, the first and second ring members (83, 86) are displaced from the state shown in fig. 6 to fig. 7. That is, the second control rotating body 87 rotates relatively in a retarded angle direction (counterclockwise direction D2 when viewed from the front of the apparatus, the same applies hereinafter) with respect to the second intermediate rotating body 84 and the first control rotating body 74 with a delay in rotation. At this time, the shaft-like member 85 moves radially inward (in the direction D3 of fig. 6(b)) along the substantially radial guide groove 84b as the second ring member 86 slides in the direction D1 inside the second eccentric circular hole 87 b. When the shaft-like member 85 moves inward along the substantially radial guide groove 84b, the first ring member 83 slides in the direction D2 inside the first eccentric circular hole 74D and gives a relative rotational torque in the direction D1 to the first control rotating body 74. The first control rotating body 74 rotates relative to the second intermediate rotating body 84 and the second control rotating body 87 in the advance angle direction (direction D1).

At the same time, the first control rotor 74 rotates relative to the first intermediate rotor 73 and the driving rotor 71 in the advance angle direction D1, and the eccentric circular cam 76 integrated with the first control rotor 74 shown in fig. 4 rotates eccentrically in the clockwise direction D1 about the center axis L1. The first intermediate rotating body 73 and the shaft-like member 81 are lowered in the direction D3 of fig. 4 in the extending direction of the rectangular hole 80 if the eccentric circular cam 76 eccentrically rotates while sliding on the inner peripheral surface of the cam guide 77.

When the shaft-like member 81 descends, the first intermediate rotating body 73 is displaced in the direction D1 along the guide grooves (79a, 79b), and rotates relative to the driving rotating body 71 in the direction D1, thereby being displaced from the state shown in fig. 4 to fig. 5. As a result, the phase angle of the camshaft (not shown) that rotates in synchronization with the first intermediate rotor 73 changes in the advance direction (direction D1) with respect to the phase angle of the driving rotor 71 driven by the crankshaft.

On the other hand, when the camshaft (not shown) is returned in the retarded angle direction (direction D2) with respect to the phase angle of the driving rotary member 71, the first electromagnetic clutch 75 brakes the first control rotary member 74. As shown in fig. 5, the eccentric circular cam 76 integrated with the braked first control rotor 74 rotates in the counterclockwise direction D2 with respect to the driving rotor 71 and the first intermediate rotor 73, and raises the first intermediate rotor 73 and the shaft member 81 in the direction D4 of fig. 5. The first intermediate rotating body 73 is displaced in the direction D2 along the guide groove 79 when the shaft-like member 81 rises, and rotates relative to the driving rotating body 71 in the direction D2, thereby returning from fig. 5 to the state of fig. 4. As a result, the phase angle of the camshaft (not shown) that rotates in synchronization with the first intermediate rotor 73 is returned in the retarded angle direction (direction D2) with respect to the phase angle of the driving rotor 71 driven by the crankshaft.

Next, a second embodiment of the phase variable device of the present application will be described with reference to fig. 8. In the first embodiment, as shown in fig. 6(a) (c), the eccentric amount of the first eccentric circular hole 74d (first ring member 83) and the eccentric amount of the second eccentric circular hole 87b (second ring member 86) are made equal and d 1. In the second embodiment, as shown in fig. 8, the eccentric amount d2 from the rotation center axis L1 of the first control rotating body 74 to the center axis L2' of the first eccentric circular hole 92 (first ring member 93) is made larger than the eccentric amount d1 of the second eccentric circular hole 87b (second ring member 86) shown in fig. 6 (a).

The first ring member 93 is disposed in the first eccentric circular hole 92 with the center axis L2' thereof sandwiching the extension line L4 (see fig. 6(b)) of the substantially radial guide groove 84b together with the center axis L3 of the second ring member 86. The second embodiment is the same as the first embodiment except for the first eccentric circular hole 92 and the first ring member 93.

In the second embodiment, since the eccentric amount d2 of the first ring member 93 of fig. 8 is larger than the eccentric amount d1 of the second ring member 86 of fig. 6(a), the torque radius becomes larger by the center axis L2' (eccentric point) of the first ring member 93 relatively rotated about the rotation center axis L1 by the second ring member 86 as compared with the center axis L3 (eccentric point) of the second ring member 86 also rotated about the rotation center axis L1. That is, the relative rotational torque generated in the first ring member 93 is larger than the rotational torque of the second ring member 86. Therefore, in the second embodiment, even if the rotational torque given to the second control rotating body 87 by the electromagnetic clutch 90 is reduced, the relative rotational torque given to the first control rotating body 74 can be increased, so that even the second brake mechanism in which there is a fear that the braking torque is insufficient can exhibit the same braking performance as the first brake mechanism. Further, the second electromagnetic clutch 90 can be arranged smaller inside the first electromagnetic clutch 75, and the phase variable device can be formed compactly.

Next, a third embodiment of the phase variable device according to the present application will be described with reference to fig. 9. In the third embodiment, the first and second ring members (83, 86) having a circular shape in the first embodiment are partially provided with notches, and the first and second ring members (94, 95) having a C-shape shown in fig. 9 are formed. When the eccentric amount d1 is made too large, the first and second ring members (83, 86) having a circular shape partially interfere with the central shaft 72. In the third embodiment, since the notch of the first ring member formed in the C-shape serves as an escape portion with respect to the central shaft 72, the eccentric amount d3 of the first and second ring members (94, 95) can be made larger, and the relative rotational torque generated in the first control rotating body 74 by the second electromagnetic clutch 90 can be further increased. The formation range of the notch portions in the first and second ring members (94, 95) is set to less than 180 DEG of the entire range.

The second ring member 83 of the first and second embodiments is rotated by 360 ° or more in the second eccentric circular hole 87b by selecting the length of the substantially radial guide groove 84 to be sufficiently long. In this case, when the second control rotor 87 rotates 360 °, the first control rotor 74 reciprocates from one end of the substantially radial guide groove to the other end thereof, and therefore rotates relative to the driving rotor 71 in both the advance angle direction and the retard angle direction. With such a configuration, the assembly angle of the crankshaft and the camshaft can be changed to both the advance angle side and the retard angle side only by the second electromagnetic clutch 90.

In the first and second embodiments, the second ring member 86 is configured to be rotatable by 360 ° or more in the second eccentric circular hole, but the first ring member (83, 93) may be configured to be rotatable by 360 ° or more in the first eccentric circular hole by the same principle. In this case, the outer diameter of the eccentric circular cam 76 is formed to have a length that can rotate 360 ° in the cam guide 77. In the case of such a configuration, since the shaft-like members 81 reciprocate at both ends of the substantially radial guide grooves 79 when the first control rotating body 74 rotates 360 °, the assembly angle of the crankshaft and the camshaft can be changed to both the advance angle side and the retard angle side only by the first electromagnetic clutch 75. That is, even when any one of the first and second electromagnetic clutches (75, 90) fails, the electromagnetic clutch that has no failure is operated to change the assembly angle of the crankshaft and the camshaft to both the advance angle side and the retard angle side (fail-safe function).

Drawings

Fig. 1 is an exploded perspective view of a phase variable device in an automobile engine as a first embodiment of the present invention, as viewed from the front.

Fig. 2 is a front view of the device.

Fig. 3 is a sectional view a-a of fig. 2 as an axial sectional view of the device.

Fig. 4 is a radial sectional view of the device before phase displacement, fig. a is a sectional view B-B of fig. 3, fig. B is a sectional view C-C of fig. 3, and fig. C is a sectional view D-D of fig. 3.

Fig. 5 is a diagram showing a state after phase shift of each cross-sectional view of fig. 4.

Fig. 6 is a radial sectional view of the device before phase displacement, fig. a is a sectional view E-E of fig. 3, fig. b is a sectional view F-F of fig. 3, and fig. c is a sectional view G-G of fig. 3.

Fig. 7 is a view showing a state after phase shift of each cross-sectional view of fig. 6.

Fig. 8 is a G-G sectional view of fig. 3 showing the first ring member and the first eccentric circular hole in the second embodiment of the phase variable device.

Fig. 9(a) is a sectional view E-E of fig. 3 showing the second ring member and the second eccentric circular hole in the third embodiment of the phase variable device, and (b) is a sectional view G-G of fig. 3 showing the first ring member and the first eccentric circular hole in the third embodiment.

Description of the symbols

71: driving rotating body

72: central shaft (component integrated with camshaft)

73: first intermediate rotating body

74: first control rotating body

74 d: first eccentric round hole (first eccentric rotating mechanism)

75: first electromagnetic clutch (first brake mechanism)

83. 93, 95: first ring component (first eccentric rotating mechanism)

83 a: first engaging hole (connecting mechanism)

84: second intermediate rotating body

84 b: substantially radial guide groove

85: shaft-shaped component (connecting mechanism)

86. 94: second ring component (second eccentric rotating mechanism)

86 a: second engaging hole (connecting mechanism)

87: second control rotating body

87 b: second eccentric round hole (second eccentric rotating mechanism)

90: second electromagnetic clutch (second brake mechanism)

L1: rotating central shaft

L2, L2': first eccentric circular hole and center axis of first ring member

L3: second eccentric circular hole and center shaft of second ring member

L4: extension line of approximately radial guide groove

d1, d 3: eccentricity of the first and second eccentric circular holes

d 2: eccentricity of the first eccentric circular hole

D1: lead angle direction (rotation direction of driving rotating body)

D2: the retarded angle direction (the direction opposite to the direction of rotation of the driving rotating body).

Claims (6)

1. A phase variable device for an engine, comprising a driving rotor rotationally driven by a crankshaft, a first intermediate rotor integrated with a camshaft, and a first control rotor receiving a rotational torque from a rotational operation force applying mechanism, the first control rotor being disposed on the same rotational center axis so as to be relatively rotatable with respect to each other, wherein a phase angle between the camshaft and the driving rotor is changed in accordance with a relative rotational direction of the first control rotor with respect to the first intermediate rotor and the driving rotor,

the turning operation force applying mechanism includes:

a first brake mechanism for relatively rotating the first control rotor with respect to the first intermediate rotor and the drive rotor;

a second intermediate rotating body integrated with the camshaft and having a substantially radial guide groove extending in a radial direction and penetrating in an axial direction;

a second control rotating body which is disposed coaxially with and relatively rotatable to the first control rotating body and the second intermediate rotating body, and which is relatively rotated by a second brake mechanism;

a first eccentric rotation mechanism which rotates eccentrically around the rotation center shaft in conjunction with the first control rotation body;

a second eccentric rotation mechanism which rotates eccentrically around the rotation center shaft in conjunction with the second control rotation body;

and a connecting mechanism engaged with the substantially radial guide groove in a displaceable manner and relatively rotatably connecting the first and second eccentric rotating mechanisms.

2. The phase variable device of an engine according to claim 1,

the first eccentric rotation mechanism includes a first eccentric circular hole formed in the first control rotating body, and a first ring member having an outer periphery engaged with an inner periphery of the first eccentric circular hole in a slidable manner,

the second eccentric rotation mechanism includes a second eccentric circular hole formed in the second control rotating body, and a second ring member having an outer periphery engaged with an inner periphery of the second eccentric circular hole in a slidable manner,

the coupling mechanism includes first and second engaging holes formed in the first and second ring members, respectively, and a coupling member that penetrates the substantially radial guide groove and has both ends inserted into the first and second engaging holes,

the central axes of the first ring member and the second ring member are disposed so as to sandwich the extension line of the substantially radial guide groove.

3. The phase variable device of an engine according to claim 2, wherein the first eccentric circular hole is formed such that an eccentric amount from a rotation central axis of the first control rotating body to a central axis of the first eccentric circular hole is larger than an eccentric amount from a rotation central axis of the second control rotating body to a central axis of the second eccentric circular hole.

4. A phase variable device of an engine according to claim 2 or 3, wherein at least one of the first and second ring members is a C-shaped ring member.

5. The phase variable device of an engine according to claim 4, wherein the substantially radial guide groove is formed to have a length that the second ring member can rotate by 360 ° or more in the second eccentric circular hole.

6. The phase variable device of an engine according to claim 2 or 3, wherein the substantially radial guide groove is formed to have a length that the second ring member can rotate by 360 ° or more in the second eccentric circular hole.