HK1164401B - Phase variable device for engine - Google Patents

Description

Phase variable device of engine

Technical Field

The present invention relates to a phase variable device for an automobile engine, which employs an eccentric circular cam in a mechanism for changing the opening/closing timing of a valve by changing the relative phase angle between a crankshaft and a camshaft in either an advance angle direction or a retard angle direction.

Background

As a conventional technique of this kind, there is a valve timing control device shown in patent document 1 below (see fig. 1 to 4 of patent document 1). In the device of patent document 1, a driving rotor 2 rotated by a crankshaft (not shown) and a guide plate 27 (a first control rotor of the present application) rotated relative to the driving rotor 2 are arranged so as to be rotatable relative to each other. In the camshaft 1, a lever member 18 is integrated, and one end of a pair of link arms (16a, 16b) is pivotally attached to the lever member 18 by a pin 25. The operation members (14a, 14b) are rotatably attached to the other ends of the link arms (16a, 16b) by a pin (24), a front protrusion (26) that engages with a spiral guide (32) at the rear of the guide plate (27) is provided at the front of the operation members (14a, 14b), and the rear of the operation members (14a, 14b) engages with the substantially radial guide grooves (11a, 11 b).

If the guide plate 27 attracted by the electromagnet 29 is rotated with respect to the driving rotor 2 with a delay, the front projection 26 of the operation member (14a, 14b) is displaced along the spiral guide 32, and the rear projection is displaced radially inward of the driving rotor 2 along the substantially radial guide groove (11a, 11 b). At this time, the link arms (16a, 16b) pivot clockwise (in the direction viewed from the guide plate 27. the same applies hereinafter) about the pin 25 with respect to the lever member 18. As a result, the assembly angle of the camshaft 1 with respect to the driving rotor 2 (the relative phase angle between the crankshaft and the camshaft) changes in the advance angle direction (the R direction in fig. 4), and the valve opening/closing timing changes.

Prior art documents

Patent document 1: japanese laid-open patent publication No. H2001-041013

Disclosure of Invention

Problems to be solved by the invention

When the valve opening/closing timing is changed to a plurality of kinds, it is desirable that the assembly angle of the camshaft 1 with respect to the driving rotor 2 can be changed as wide as possible. In the device of patent document 1, the link arms (16a, 16b) are made longer, and the outer diameters of the driving rotor 2 and the guide plate 27 are made larger, whereby the range of variation of the assembly angle can be widened. However, in this case, the phase variable device is large in size. On the other hand, in the engine, the accommodation space of the phase variable device is limited. Therefore, the device of patent document 1 has a limit in increasing the size of the device, and therefore has a limit in increasing the range in which the assembly angle can be changed.

In the device of patent document 1, when the accuracy of coupling the link arms (16a, 16b) and the pins (24, 25) is low and the accuracy of engaging the work operating members (14a, 14b) with the spiral guide 32 is low, the link arms (16a, 16b) may not be smoothly rotated with respect to the lever member 18, and the work operating members (14a, 14b) may not be smoothly displaced with respect to the spiral guide 32. Forming these components with high precision has a problem in that the manufacturing cost increases.

The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a phase variable device for an engine, which can make the size of the device compact, and which can make the range of variation of the assembly angle (relative phase angle) between a driving rotary body (crankshaft) and a camshaft wider than that of the conventional one, and which can be easily manufactured.

Means for solving the problems

The present invention according to claim 1 provides a phase variable device for an engine, in which a driving rotating body that rotates on a crankshaft and a first control rotating body that rotates relative to the driving rotating body by a rotational operation force applying mechanism are supported so as to be rotatable relative to a camshaft, and an assembly angle of the camshaft relative to the driving rotating body is changed by an assembly angle changing mechanism that is interlocked with the relative rotation of the first control rotating body, so as to change a relative phase angle between the camshaft and the crankshaft, the assembly angle changing mechanism including: a first eccentric circular cam integrated with the first control rotating body in a state of being eccentric from a rotation center axis of the camshaft; a second eccentric circular cam integrated with the camshaft in a state of being eccentric from a rotation center axis of the camshaft; and a cam guide member for connecting the first eccentric circular cam and the second eccentric circular cam to be capable of relative eccentric rotation, and converting the eccentric rotation of the first eccentric circular cam into the eccentric rotation of the second eccentric circular cam, whereby an assembly angle of the camshaft with respect to the driving rotary body is changed in accordance with the relative eccentric rotation of the second eccentric circular cam with respect to the first eccentric circular cam.

The first control rotating body is relatively rotated in either a lead angle direction (the same direction as the rotation direction of the driving rotating body rotated by the crankshaft, hereinafter the same) or a lag angle direction (the opposite direction to the rotation direction of the driving rotating body, hereinafter the same) with respect to the driving rotating body by the rotation operation force imparting mechanism. The first eccentric circular cam is integrated with the first control rotating body to eccentrically rotate about the rotation center axis of the camshaft. The eccentric rotation of the first eccentric circular cam is converted into the eccentric rotation of the second eccentric circular cam by the cam guide member. Since the camshaft rotates together with the second eccentric circular cam relative to the driving rotating body, the assembly angle (relative phase angle) of the camshaft with respect to the driving rotating body (crankshaft) is changed.

The assembly angle of the camshaft with respect to the driving rotary body is changed to be larger in proportion to the moving distance of the central axis of the second eccentric circular cam when the assembly angle is changed. Therefore, even if the assembly angle (relative phase angle) of the camshaft with respect to the driving rotary body (crankshaft) is not increased by increasing the outer diameters of the first and second eccentric circular cams, the range of the variation can be further expanded by increasing the eccentricity of the second eccentric circular cam (increasing the distance from the rotation center axis of the camshaft to the center axis of the eccentric circular cam) and increasing the moving distance of the center axis of the second eccentric circular cam.

In addition, even if the assembly angle of the camshaft with respect to the driving rotary body is not formed with high precision, the eccentric rotation of the first and second eccentric circular cams by the cam guide member can be smoothly changed.

Further, according to claim 2 of the present invention, in the phase variable device of the engine according to claim 1, the driving rotating body is provided with a substantially radial guide groove extending in a direction orthogonal to a rotation center axis of the camshaft,

the cam guide member is provided with a pair of holding portions and an oblong hole,

the pair of holding portions hold the outer periphery of the first eccentric circular cam from both sides so as to penetrate through the substantially radial guide groove, and are displaced along the substantially radial guide groove by eccentric rotation of the first eccentric circular cam,

the oval hole extends in a direction orthogonal to a direction in which the substantially radial guide groove extends, and displaces the second eccentric circular cam in a direction orthogonal to the direction in which the substantially radial guide groove extends while making sliding contact with the inside.

The cam guide member is displaced along the guide groove by eccentric rotation of the first eccentric circular cam inside by the grip portion engaged with the substantially radial guide groove of the driving rotating body, and swings in a direction orthogonal to the rotation center axis of the camshaft. The swinging cam guide member extends in a direction in which the oblong hole is orthogonal to the substantially radial guide groove, and therefore eccentrically rotates the second eccentric circular cam engaged in slidable contact with the inside thereof.

The first eccentric circular cam, the cam guide member, and the second eccentric circular cam are configured such that the pair of eccentric circular cams slide inside the grip portion and the oblong hole, and therefore, they smoothly move relative to each other even if they are not formed with high accuracy, and therefore, the assembly angle of the camshaft with respect to the driving rotating body can be smoothly changed.

Further, the assembly angle of the camshaft with respect to the driving rotary member can be selectively changed from the initial position before the phase angle change to either the advance angle direction or the retard angle direction by arranging the center axes of the first and second eccentric circular cams in the initial position before the phase angle change to be inclined in the same direction with respect to the direction in which the substantially radial guide grooves of the driving rotary member extend, or inclined in opposite directions with respect to each other with the guide grooves therebetween. That is, when the central axes of the first and second eccentric circular cams are disposed so as to be inclined in the same direction with respect to the direction in which the substantially radial guide groove of the driving rotary body extends, the second eccentric circular cam eccentrically rotates in the same direction as the first eccentric circular cam, and when the central axes of the first and second eccentric circular cams are disposed so as to be inclined in mutually opposite directions with respect to the guide groove, the second eccentric circular cam eccentrically rotates in a mutually opposite direction to the first eccentric circular cam. Therefore, the direction of the assembly angle is changed from the initial position before the phase angle change, and the arrangement of the central axis of the second eccentric circular cam in the initial position before the phase angle change is changed, whereby the direction can be easily changed from the advancing angle direction to the retarded angle direction or from the retarded angle direction to the advancing angle direction.

In addition, claim 3 of the present invention is the phase variable device of the engine according to claim 1 or claim 2, wherein the rotational operation force imparting means is constituted by a first brake means for relatively rotating the first control rotating body in a retarded angle direction (the direction opposite to the direction in which the driving rotating body rotates from the crankshaft) with respect to the driving rotating body, and a reverse rotation means for relatively rotating the first control rotating body in a advanced angle direction (the direction same as the direction in which the driving rotating body rotates from the crankshaft).

The first brake mechanism is operated to change the assembly angle of the camshaft with respect to the driving rotating body (crankshaft) in either the advance angle direction or the retard angle direction, and the reverse rotation mechanism is operated to change the assembly angle in the opposite direction to the first brake mechanism.

In addition, according to claim 4 of the present invention, in the phase variable device for an engine according to claim 3, the counter rotation mechanism includes a second control rotating body disposed in a state of being relatively rotatable with respect to a camshaft, a second brake mechanism for braking the second control rotating body to rotate in a retarded angle direction with respect to the first control rotating body, and a ring mechanism for rotating the first control rotating body in an advanced angle direction with respect to the driving rotating body when the second brake mechanism is operated, and the ring mechanism includes: a first ring member that is in sliding contact with a first eccentric circular hole formed in the first control rotating body; a second ring member which is in sliding contact with a second eccentric circular hole formed in the second control rotating body; an intermediate rotating body having a substantially radial guide groove and rotating integrally with the camshaft; and a connecting member having both ends projecting from the substantially radial guide groove of the intermediate rotating body, the first ring member and the second ring member being mounted on the projecting both ends so as to be relatively eccentrically rotatable, and being displaceable along the substantially radial guide groove.

The second control mechanism (action) relatively rotates the first control rotating body in the advance angle direction with respect to the driving rotating body via a ring mechanism that operates as follows. When the second brake mechanism brakes the second control rotating body, the second eccentric circular hole of the second control rotating body eccentrically rotates about the center axis of the camshaft. The second ring member is slidably rotated in the second eccentric circular hole by the eccentric rotation of the second eccentric circular hole, and displaces the coupling member along the substantially radial guide groove of the intermediate rotating body. The first ring member slides and rotates in the first eccentric circular hole of the first control rotating body when the connecting member is displaced. The first control rotating body receives a relative rotation torque by the sliding rotation of the first ring member, and rotates relative to the driving rotating body in the advance angle direction.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the phase variable device for an engine according to the aspects of the present invention, the size of the phase variable device can be reduced, and the range in which the assembly angle (relative phase angle) of the camshaft with respect to the driving rotating body (crankshaft) can be changed can be made wider than in the conventional case.

Further, the mechanism in which a plurality of eccentric circular cams used in the assembly angle changing mechanism of the camshaft and the driving rotating body are combined has a smaller number of components, and is simple in shape and easy to obtain accuracy, and therefore, operates more smoothly than the mechanism using the link arm mechanism and the spiral guide. Therefore, the phase variable device of the engine of the present application can be manufactured easily and inexpensively.

Further, the mechanism in which a plurality of eccentric circular cams used in the assembly angle changing mechanism of the camshaft and the driving rotating body are combined has a simple structure and a small number of components, and therefore operates smoothly even with a lower accuracy than the mechanism using the link arm mechanism and the spiral guide. Therefore, the phase variable device of the engine of the present application can be manufactured easily and at low cost.

Drawings

Fig. 1 is a perspective view showing a first embodiment of a phase variable device in an automobile engine.

Fig. 2 is an exploded perspective view of fig. 1.

Fig. 3 is an axial sectional view of fig. 1.

Fig. 4 is a radial sectional view of the phase variable device (retarded angle gauge) of the first embodiment in an initial state, in which (a) is a sectional view a-a of fig. 3 showing the arrangement of the first eccentric circular cam, and (B) is a sectional view B-B of fig. 3 showing the arrangement of the second eccentric circular cam in the retarded angle gauge.

Fig. 5 is a radial sectional view of the phase variable device (retarded angle specification) according to the first embodiment after the change of the assembly angle, wherein (a) is a sectional view taken along line a-a of fig. 3, and (B) is a sectional view taken along line B-B of fig. 3.

Fig. 6 is a sectional view of the arrangement of the second eccentric circular cam in the lead angle specification, (a) is a sectional view B-B of fig. 3 in an initial state, and (B) is a sectional view B-B of fig. 3 after the assembly angle is changed.

Fig. 7 is a radial sectional view of the reverse rotation mechanism in an initial state, in which (a) is a sectional view of fig. 3C-C, (b) is a sectional view of fig. 3D-D, and (C) is a sectional view of fig. 3E-E.

Fig. 8 is a radial sectional view of the reverse rotation mechanism after the assembly angle is changed, where (a) is a sectional view taken along line C-C in fig. 3, (b) is a sectional view taken along line D-D in fig. 3, and (C) is a sectional view taken along line E-E in fig. 3.

Fig. 9 is an axial cross-sectional view showing a second embodiment of a phase varying device in an automobile engine provided with different counter-rotating mechanisms.

Fig. 10 is an axial cross-sectional view showing a third embodiment of a phase variable device in an automobile engine provided with different counter-rotation mechanisms.

Description of the symbols

30: phase variable device of engine, 31: driving rotating body, 33: cam guide member, 34: first control rotating body, 34 f: first eccentric circular hole, 35: first electromagnetic clutch (first brake mechanism), 36, 37: sprocket, 40: drive cylinder, 41: first eccentric circular cam, 45: camshaft, 46: second eccentric circular cam, 47: radial guide groove of drive cylinder, 48: grip of cam guide member, 49: oblong hole of cam guide member, 50: first ring member, 51: intermediate rotating body, 52: coupling member, 53: second ring member, 54: second control rotating body, 54 c: second eccentric circular hole, 56: second brake mechanism, 57, 62: reverse rotation mechanism, 59: torsion coil spring (reverse rotation mechanism), 60: control rotating body, 61: drive disk, 65: assembly angle changing mechanism, 66: rotation operation force imparting mechanism, 67: ring mechanism, L0: rotation center shaft of camshaft, L3: radial guide groove extension direction of drive cylinder, L4: the direction in which the oblong hole of the cam guide member extends.

Detailed Description

Preferred modes for carrying out the invention

Next, embodiments of the present invention will be described with reference to first to third examples.

The phase variable device for an engine according to each embodiment is a device that is incorporated in an engine, transmits rotation of a crankshaft to a camshaft so as to open and close an intake/exhaust valve in synchronization with the rotation of the crankshaft, and changes the opening/closing timing of the intake/exhaust valve of the engine according to an operating state such as a load or a rotational speed of the engine.

The structure of the device of the first embodiment will be described with reference to FIGS. 1 to 8. The phase varying device 30 of the engine in the first embodiment is composed of a driving rotary body 31, a center shaft 32, an assembly angle changing mechanism 65, and a rotational operation force applying mechanism 66, which are disposed on a rotational center axis L0, respectively. The assembly angle changing mechanism 65 is constituted by the first eccentric circular cam 41, the cam guide member 33, and the second eccentric circular cam 46. The rotational operation force imparting mechanism 66 is constituted by the first electromagnetic clutch 35 and the reverse rotation mechanism 57. In the following description, the second electromagnetic clutch 56 side in fig. 2 is referred to as the apparatus front side, the sprocket 36 side is referred to as the apparatus rear side, the rotational direction of the driving rotor 31 viewed from the front side of the apparatus is referred to as the clockwise direction D1 (advance angle direction), and the opposite direction to D1 is referred to as the counterclockwise direction D2 (retard angle direction).

The center shaft 32, the cam guide member 33, and the first control rotating body 34 in an initial state before the assembly angle is changed (hereinafter simply referred to as an initial state) receive a driving force from a crankshaft (not shown), and rotate in the direction D1 together with the driving rotating body 31 rotating around the rotation center shaft L0.

The driving rotator 31 is composed of two sprockets (36, 37) and a driving cylinder 40. Round holes (36a, 37a) are provided in the centers of the sprockets (36, 37). An inner flange 37b is provided near the rear end opening inside the circular hole 37 a. Reference numeral 37c denotes a circular hole inside the inner flange 37 b. The disc springs 42 stacked in the direction of the center axis L0 are inserted into the circular hole 37 c. The disc spring 42 has a circular hole 42a at the center. The retainer 43 having a circular hole 43a at the center is engaged with the circular hole 37a from the front.

The cylindrical portion 40a and the bottom portion 40b of the drive cylinder 40 are integrally formed. The bottom portion 40b is provided with a circular hole 40c and a pair of substantially radial guide grooves (47, 47). The circular hole 40c is provided at the center of the bottom portion 40b, and is inserted through an intermediate cylindrical portion 32b of the center shaft 32, which will be described later. The substantially radial guide grooves (47, 47) are provided at positions which are symmetrical with respect to the circular hole 40c therebetween. In the following description, an extension line passing through the rotation center axis L0 of the drive cylinder 40 and extending along the substantially radial guide grooves (47, 47) is referred to as L3 (see fig. 4).

The sprocket 36 is integrated with the sprocket 37 by a coupling pin 38 inserted into the plurality of pin holes 36b, and the sprocket 37 is integrated with the drive cylinder 40 by a coupling pin 39 inserted into a plurality of pin holes (37d, 40d) provided in the sprocket 37 and the drive cylinder 40, respectively.

The center shaft 32 has a shape in which the small cylinder portion 32a, the middle cylinder portion 32b, the second eccentric circular cam 46, and the large cylinder portion 32c are continuous from the front in the direction of the rotation axis L0. The outer diameter of the large cylindrical portion 32c is formed to be substantially the same as the inner diameter of the circular holes (36a, 42a, 43 a). The second eccentric circular cam 46 has a center axis L2 eccentric by a distance d2 from the rotation center axis L0 of the center axis 32, and eccentrically rotates around the rotation center axis L0 integrally with the center axis 32.

The driving rotor 31 is rotatably supported by the center shaft 32 by inserting the large cylindrical portion 32c of the center shaft 32 into the circular holes (36a, 42a, 43 a). The center shaft 32 has a bolt insertion hole 32d at the center and a coupling hole 32e at the rear end. The camshaft 45 includes a cylindrical portion 45a at a distal end thereof, and a flange portion 45b continuous with the cylindrical portion. The center shaft 32 is coupled to the camshaft 45 by inserting the distal end cylindrical portion 45a of the camshaft 45 into the coupling hole 32e while supporting the driving rotor 31 on the large cylindrical portion 32c, and is fixed to the camshaft 45 by screwing the distal end male screw portion (not shown) of the bolt 44 inserted into the bolt hole 32d from the front of the apparatus (left side in fig. 3) to the distal end female screw portion (not shown) of the camshaft 45. The driving rotor 31 is disposed between the second eccentric circular cam 46 and the flange portion 45b of the camshaft 45, and rotates relative to the camshaft 45 about the center axis L0.

On the other hand, the cam guide member 33 has a pair of gripping portions (48, 48) and an oblong hole 49. A pair of gripping portions (48, 48) are provided projecting from the outer peripheral end of the cam guide member 33 in front of the apparatus, respectively, and the line connecting the gripping portions (48, 48) is orthogonal to the central axis L0. The gripping portions have substantially the same width as the substantially radial guide grooves (47, 47) of the drive cylinder 40, and are provided at substantially the same intervals as the substantially radial guide grooves (47, 47). The oblong hole 49 is formed so as to extend in a direction L4 orthogonal to a line connecting the gripping portions (48, 48) (see fig. 4 (b)). The upper and lower end portions of the outer peripheral surface of the second eccentric circular cam 46 are in sliding contact with the inner peripheral surface of the oblong hole 49.

The cam guide member 33 is disposed between the sprocket 37 and the drive cylinder 40, and is supported on the center shaft 32 via a second eccentric circular cam 46 inserted into an elongated hole 49. The gripping portions (48, 48) are engaged with the substantially radial guide grooves (47, 47), and the distal ends thereof protrude forward from the substantially radial guide grooves (47, 47). The gripping portions (48, 48) are displaced in the radial direction of the drive cylinder 40 along the substantially radial guide grooves (47, 47) if the second eccentric circular cam 46 is eccentrically rotated.

The first control rotating body 34 is formed in a circular shape, has an outer diameter substantially equal to an inner diameter of the inner circumferential surface 40e of the cylindrical portion of the drive cylinder 40, and is inserted inside the cylindrical portion 40 a. The first control rotor 34 has an outer peripheral surface 34a supported by a cylindrical inner peripheral surface 40e and rotates relative to the drive cylinder 40 about the rotation center axis L0. The first control rotating body 34 is provided with a first eccentric circular cam 41 and a circular hole 34b penetrating through the middle cylindrical portion 32b of the center shaft 32.

The first eccentric circular cam 41 protrudes rearward from the rear surface of the first control rotating body 34. The first eccentric circular cam 41 eccentrically rotates around the rotation center axis L0 integrally with the first control rotating body 34 by an eccentric distance d1 from the rotation center axis L0 (eccentric point) of the first control rotating body 34 at the center axis L1. The first eccentric circular cam 41 grips the outer periphery by gripping portions (48, 48) protruding from substantially radial guide grooves (47, 47), and is in sliding contact with the inside of the gripping portions (48, 48).

In an initial state before the change of the assembly angle, as shown in fig. 4, the eccentric point (the cam center axis L1) of the first eccentric circular cam 41 is arranged at a position inclined in the counterclockwise direction D2 from above the extension line L3 with respect to the drive cylinder 40, and the gripping portions (48, 48) of the cam guide member 33 are arranged in a state where one of the gripping portions is in contact with the stopper portion 47a formed at the upper end of the substantially radial guide grooves (47, 47).

On the other hand, the eccentric point (the center axis L2) of the second eccentric circular cam 46 in the initial state is disposed so as to be inclined in the counterclockwise direction D2 from above the extension line L3 similarly to the center axis L1 of the first eccentric circular cam 41 (see fig. 4(b)), or so as to be inclined in the clockwise direction D1 opposite to the center axis L1 (see fig. 6 (a)).

As shown in fig. 4b, if the center axis L2 of the second eccentric circular cam 46 is disposed to be inclined from above the extension line L3 toward the D2 direction similarly to the center axis L1, the assembly angle of the camshaft 45 with respect to the driving rotor 31 is changed from the initial state toward the retarded angle side D2 direction, and as shown in fig. 6a, if the center axis L2 is disposed to be inclined from above the extension line L3 toward the D1 direction opposite to the center axis L1, the assembly angle is changed from the initial state toward the advanced angle side D1 direction (hereinafter, the inclination of the center axis L2 in the initial state toward the same direction as the center axis L1 is referred to as the retarded angle specification, and the inclination of the center axis L1 is referred to as the advanced angle specification). That is, in the present embodiment, the retard angle specification and the advance angle specification described above can be simply replaced by changing only the arrangement of the first and second eccentric circular cams 41 and 46 in the initial position and the direction of inclination of the central axis L2 with respect to the extension line L3.

The first electromagnetic clutch 35 and the counter rotation mechanism 57 are provided in front of the first control rotation body 34. The first electromagnetic clutch 35 (first brake mechanism) is disposed opposite to the front surface (attracting surface 34c) of the first control rotating body, and is fixed to an engine case (not shown). When the coil 35a is energized, the first electromagnetic clutch 35 attracts the front surface (attracting surface 34c) of the first control rotating body 34 rotating together with the driving rotating body 31, and slides on the friction material 35 b.

If the suction surface 34c is in sliding contact with the friction material 35b, the first control rotor 34 is rotated in the advance direction D2 (see fig. 2 and 4) relative to the driving rotor 31 with a delay in rotation relative to the driving rotor 31. Further, if a reverse rotation mechanism 57, which will be described later, is operated, the first control rotating body 34 rotates relative to the driving rotating body 31 in the advance direction D1, in contrast to the first electromagnetic clutch 35.

The reverse rotation mechanism 57 is constituted by the second controlling rotation body 54, the second electromagnetic clutch 56, and the ring mechanism 67 is constituted by the first ring member 50, the intermediate rotation body 51, and the movable member 52 disposed in the stepped circular hole 34d in front of the first controlling rotation body 34, and the second ring member 53 and the second controlling rotation body 54 disposed in the stepped circular hole 54c in rear of the second controlling rotation body 54.

The first control rotating body 34 has a stepped circular hole 34d in the front surface. A first eccentric circular hole 34f having a stepped shape is provided in a bottom portion 34e of the stepped circular hole 34 d. The first eccentric circular hole 34f has its center O1 eccentric from the rotation center axis L0 of the center shaft 32 by a distance d 3. The first ring member 50 has an outer diameter substantially equal to the inner diameter of the eccentric circular hole 34f, and is in sliding contact with the inner circumference of the eccentric circular hole 34 f. A first engagement hole 50a opened on the front surface is formed in the first ring member 50.

The intermediate rotating body 51 has a square hole 51a at the center thereof and a substantially radial guide groove 51b extending in the radial direction of the intermediate rotating body 51 on the outer side thereof. An extension line extending along the substantially radial guide groove 51b through the rotation center axis L0 of the intermediate rotor 51 is L5. The intermediate rotating body 51 is engaged with the flat engaging surfaces (32f, 32g) of the center shaft 32 through the square holes 51a, and is fixed to the center shaft 32 in a non-rotatable state.

The second control rotating body 54 has a circular hole 54a at the center and a second eccentric circular hole 54c having a step shape at the rear. The second control rotating body 54 is rotatably supported on the center shaft 32 by the small cylindrical portion 32a inserted into the circular hole 54 a. The center O2 of the second eccentric circular hole 54c is eccentric from the rotation center axis L0 by a distance d4 in the same manner as the second eccentric circular hole. The second ring member 53 has an outer diameter substantially equal to the inner diameter of the second eccentric circular hole 54c, and is in sliding contact with the inner periphery of the second eccentric circular hole 54 c. The second ring member 53 includes a second engagement hole 53a opened in the rear surface. The first and second ring members (50, 53) are arranged with centers (O1, O2) on both sides with an extension line L5 in between.

The movable member 52 is configured by inserting a thin circular shaft 52a into the center of a hollow thick circular shaft 52 b. The thin circular shaft 52a is slidably engaged with the first and second engaging holes (50a, 53a) at both ends thereof, and connects the first and second ring members (50, 53). The hollow round shaft 52b is displaced along the engaged substantially radial guide groove 51 b.

A retainer 55 is disposed at the tip of the small cylindrical portion 32a of the center shaft 32 protruding from the circular hole 54 a. The components of fig. 2 from the holder 55 to the sprocket 36, except for the center shaft 32, are held by the cam shaft 45 by inserting the bolts 44 from the front into holes formed in the respective centers and screwing the bolts to the tip end portion of the cam shaft 45 (see fig. 3).

The second electromagnetic clutch 56 is disposed to face the front surface of the second control rotating body 54, and is fixed to an engine case, not shown. The second electromagnetic clutch 56, which has energized the coil 56a, attracts the front attracting surface 54b of the second control rotating body 54 to be in sliding contact with the friction material 56b, thereby braking the rotation of the second control rotating body 54.

The movable member 52 may be provided with a bearing or may be replaced with a ball. In this case, since the movable member 52 rolls in the groove 51b, the frictional resistance is reduced, and the power consumption of the electromagnetic clutches (35, 56) can be reduced. It is preferable that the second intermediate rotating body 51 is formed of a nonmagnetic material. When the second intermediate rotating body 51 is formed of a non-magnetic body, the magnetic force of one of the attracting control rotating bodies (34, 54) is not transmitted to the other control rotating body, so that the disadvantage that the first and second control rotating bodies (34, 54) are attracted together can be eliminated by one electromagnetic clutch.

Next, the operation of the phase variable device 30 in the present embodiment will be described with reference to fig. 2 to 7. When the first control rotating body 34 in fig. 2 is braked by the first electromagnetic clutch 35, a relative rotation in the counterclockwise direction D2 occurs with a delay in rotation of the driving rotating body 31, the center shaft 32, and the cam guide member 33.

The first eccentric circular cam 41 in fig. 4(a) is eccentrically rotated in the counterclockwise direction D2 around the rotation center axis L0 integrally with the first control rotating body 34. The gripping portions (48, 48) of the cam guide member 33 are displaced in the direction D3 downward along the substantially radial guide grooves (47, 47) by the first eccentric circular cam 41 which is in sliding contact with the inside. The cam guide member 33 descends in the direction D3 integrally with the grip portions (48, 48). The operations up to this point are common to both the retardation angle specification of fig. 4(b) and the lead angle specification of fig. 6 (a).

In the second eccentric circular cam 46 of the retarded angle standard, as shown in fig. 4(b), if the cam guide plate 33 descends, the force is applied from the oblong hole 49 that descends at the same time to eccentrically rotate in the counterclockwise direction D2. The central shaft 32 (the cam shaft 45) is integrated with the second eccentric circular cam 46, and therefore rotates relative to the driving rotor 31 in the direction D2. As a result, the assembly angle of the camshaft 45 with respect to the driving rotor 31 (crankshaft not shown) changes from the initial position to the counterclockwise direction D2 (retarded angle direction).

On the other hand, in the lead angle specification, if the cam guide plate 33 is lowered, the second eccentric circular cam 46 eccentrically rotates in the clockwise direction D1 opposite to the retard angle specification as shown in fig. 6(a), and the center shaft 32 (the cam shaft 45) rotates relative to the driving rotor 31 in the direction D1. As a result, the assembly angle of the camshaft 45 with respect to the driving rotor 31 (crankshaft not shown) is changed from the initial position to the clockwise direction D1 (advance angle direction).

On the other hand, when the once-changed assembly angle is returned in the direction of the initial position, the reverse rotation mechanism 57 is operated to rotate the first control rotating body 34 relative to the driving rotating body 31 in the advance angle direction (direction D1).

Specifically, the second electromagnetic clutch 56 is actuated. When the second electromagnetic clutch 56 shown in fig. 2 is actuated, the second control rotating body 54 of fig. 7(a) braked by the second electromagnetic clutch 56 causes a rotation delay with respect to the intermediate rotating body 51 and the first control rotating body 34, and rotates in the delay angle direction D2. The second ring member 53 slides in the direction D1 inside the second eccentric circular hole 54c, and displaces the movable member 52 downward (direction D3 in fig. 7 b) along the substantially radial guide groove 51 b. In the first ring member 50 of fig. 7(c), if the movable member 52 is displaced in the direction D3, it slides in the direction D2 inside the first eccentric circular hole 34f, and a relative rotational moment in the direction D1 is applied to the first control rotating body 34. As a result, the first control rotating body 34 rotates in the advancing direction (direction D1) relative to the intermediate rotating body 51 and the second control rotating body 54, in reverse to the operation of the first electromagnetic clutch 35.

When the first control rotor 34 is rotated relative to the driving rotor 31 in the lead angle direction D1, the first eccentric circular cam 41 is eccentrically rotated in the clockwise direction D1 about the rotation center axis L0 as shown in fig. 5(a), and the grip portions (48, 48) and the cam guide member 33 are raised in the direction D4 along the substantially radial guide grooves (47, 47). The second eccentric circular cam 46 (the center shaft 32) of fig. 5(b) in the retarded angle specification rotates relative to the driving rotary member 31 in the advance angle direction (the direction D1) if the cam guide member 33 moves upward. As a result, the assembly angle of the crankshaft with respect to the driving rotor 31 returns in the direction of the initial position. In the retarded angle specification, the second eccentric circular cam 46 (the center shaft 32) of fig. 6(b) rotates relative to the driving rotary member 31 in the retarded angle direction (the direction D2) if the cam guide member 33 moves upward. As a result, the assembly angle of the crankshaft with respect to the driving rotor 31 returns in the direction of the initial position.

Next, a second embodiment of the phase variable device in the automobile engine will be described with reference to fig. 9. The phase variable device of the second embodiment has a structure common to the first embodiment except that the reverse rotation mechanism 57 formed of the eccentric ring of the first embodiment is replaced with a torsion coil spring 59 as the reverse rotation mechanism.

The reverse rotation mechanism of the second embodiment is simply constituted by the torsion coil spring 59. The torsion coil spring 59 has one end 59a fixed to the drive cylinder 40 and the other end 59b fixed to the first control rotating body 34, and normally biases the first control rotating body 34 in a direction (advance direction D1) opposite to a direction (retard direction D2 in fig. 2) in which the first control rotating body 34 receives the braking torque from the first electromagnetic clutch 34.

The first control rotor 34 that rotates together with the drive cylinder 40 (drive rotor 31) is rotated relative to the drive cylinder 40 in the retarded angle direction D2 if a braking torque exceeding the biasing torque of the torsion coil spring 59 is received from the first electromagnetic clutch 35, and the assembly angle of the center shaft 32 (cam shaft 45) to the first drive rotor 31 is changed to a predetermined direction (the direction of the advanced angle side D1 or the direction of the retarded angle side D2). The relative rotation of the first control rotating body 34 with respect to the drive cylinder 40 is stopped if the biasing torque of the coil spring 59 applied to the first control rotating body 34 is balanced with the braking torque of the first electromagnetic clutch 35. Since the assembly angle of the camshaft 45 with respect to the first driving rotating body 31 is determined by the stop position of the first control rotating body 34 with respect to the driving cylinder 40, the adjustment is performed by changing the amount of current passage of the first electromagnetic clutch 35.

On the other hand, if the first electromagnetic clutch 35 is stopped, the first control rotating body 34 is rotated in the advance direction D1 relative to the driving cylinder 40 by the biasing torque of the torsion coil spring 59, and returns to the initial position before the phase angle is changed.

Further, the camshaft 45 rotating together with the crankshaft (not shown) periodically receives a reaction force from a valve spring (not shown). This reaction force generates a moment (hereinafter, simply referred to as a disturbance moment) that rotates the camshaft 45 relative to the driving rotor 31 in either the advance angle direction D1 or the retard angle direction D2. The disturbance moment may cause an unexpected deviation in the assembly angle between the driving rotary body 31 and the camshaft 45.

The phase variable devices according to the first and second embodiments have a self-lock mechanism that prevents unexpected variation in the assembly angle due to the disturbance torque by locking the camshaft 45 to the drive rotor 31 so as not to automatically rotate relative thereto if the disturbance torque is generated.

The operation of the self-locking mechanism will be described. The disturbance torque received by the camshaft 45 from the valve spring is transmitted as an eccentric rotation torque to the second eccentric circular cam 46. When the second eccentric circular cam 46 receives an eccentric rotational moment in the oblong hole 49, the transmission cam guide member 33 receives a force in the direction of the extension line L3 because the grip portions (48, 48) are guided along the substantially radial guide grooves (47, 47) of the drive cylinder 40. The first eccentric circular cam 41 integrated with the first control rotating body 34 receives a force from the gripping portions (48, 48) in the direction of the extension line L3 perpendicular to the rotation center axis L0.

As a result, if a disturbance torque is generated in the camshaft 45, the first control rotor 34 receives a force in a direction perpendicular to the rotation center axis L0, and the outer peripheral surface 34a thereof locally contacts the inner peripheral surface 40e of the cylindrical portion of the drive cylinder 40 to generate a frictional force, thereby being locked in a state in which it cannot automatically rotate relative to the drive cylinder 40 (hereinafter referred to as a self-lock function).

When the first control rotating body 34 and the drive cylinder 40 are locked so as not to be able to rotate relative to each other, the first eccentric circular cam 41, the cam guide member 33, and the second eccentric circular cam 46 are locked so as not to be able to move relative to each other, and therefore, it is possible to prevent a deviation in the assembly angle of the cam shaft 45 relative to the drive rotating body 31.

It is preferable that a certain gap be provided between the inner peripheral surfaces of the circular holes (34b, 40c) of the first control rotating body 34 and the drive cylinder 40 and the outer peripheral surface of the middle cylindrical portion 32b of the center shaft 32. If a certain gap is not set, the inner circumferential surface of the circular hole 34b of the first control rotating body 34 during self-locking may contact the outer circumferential surface of the middle cylindrical portion 32b before the outer circumferential surface 34a contacts the inner circumferential surface 40e of the cylindrical portion, and receive the rotational moment of the central shaft 32. Since this rotational moment reduces the local frictional force generated on the outer peripheral surface 34a of the first control rotating body, it is preferable to provide a certain gap between the inner peripheral surfaces of the circular holes (34b, 40c) and the outer peripheral surface of the intermediate cylindrical portion 32 b.

A third embodiment of a phase variable device in an automobile engine will be described with reference to fig. 10. The phase variable device of the third embodiment has the same configuration as the second embodiment except that the first controlling rotating body 34 and the driving cylinder 40 of fig. 9 are replaced with a controlling rotating body 60 and a driving circular plate 61 having different shapes, and the torsion coil spring 59 is not required. The phase variable device of the third embodiment includes a control rotating body 60 relatively rotatably supported by an intermediate cylindrical portion 32b of the center shaft 32 inserted into the circular hole 60b, and a counter rotating mechanism 62 including a driving disk 61 having a shape obtained by removing the cylindrical portion 40b from the shape of the driving cylinder 40. The reverse rotation mechanism 62 rotates the control rotor 60 relative to the driving rotor 31 in the direction D1 in fig. 2 by using the disturbance torque generated in the camshaft 45. The operation of the reverse rotation mechanism 60 will be described below.

The driving disk 61 has a shape in which the cylindrical portion 40b is removed from the driving cylinder 40 of fig. 9. The driving disk 61 is not provided with a portion corresponding to the inner circumferential surface 40e of the cylindrical portion supporting the outer circumferential surface 34a of the control rotating body 34 in the second embodiment. Therefore, the control rotating body 60 is relatively rotatably supported on the middle cylindrical portion 32b of the center shaft 32 inserted in the center circular hole 60 b.

Further, no self-locking mechanism is provided between the control rotating body 34 and the driving disk 61. That is, since the driving disk 61 is not provided with a contact surface of the control rotating body 60 corresponding to the inner circumferential surface 40e of the cylindrical portion of the first embodiment, the self-locking function is not generated even if the disturbance torque is generated in the camshaft 45 in the outer circumferential surface 60a of the control rotating body 60. Therefore, the control rotating body 60 receives a relative rotational torque to the driving disk 61 due to the disturbance torque generated in the cam shaft 45.

The relative rotational torque generated by the disturbance torque is a pulsating torque transmitted from a valve spring (not shown) to the camshaft 45 in conjunction with the engine rotation, and therefore, acts on the control rotor 60 in the advance angle side D1 direction and the retard angle side D2 direction alternately and repeatedly. However, since the torque in the direction D1 (the rotation direction of the cam shaft 45) of the relative rotation torque is larger than the torque in the direction D2, the control rotor 60 rotates relative to the driving disk 61 in the leading angle side D1 direction if it receives the disturbance torque of the cam shaft 45.

As a result, if the first electromagnetic clutch 35 brakes with a relative rotational torque in the direction D1 due to the disturbance torque, the control rotating body 60 rotates relative to the driving disk 61 in the direction D2, and if the electromagnetic clutch 35 is stopped, the control rotating body rotates relative to the driving disk 61 in the direction D1 due to the disturbance torque. The relative rotation of the control rotating body 60 with respect to the driving circular plate 61 is stopped if the relative rotation torque of the disturbance torque and the braking torque of the electromagnetic clutch 35 are balanced. The assembly angle of the camshaft 45 with respect to the driving rotary member 31 is changed in either the leading angle side D1 direction or the trailing angle side D2 direction by the electromagnetic clutch 35, the disturbance torque received by the camshaft 45 is returned in the direction opposite to the direction generated by the electromagnetic clutch 35, and the assembly angle is fixed by balancing the relative rotational torque of the braking torque of the electromagnetic clutch and the disturbance torque.

Claims (4)

1. A phase variable device for an engine, in which a driving rotating body for rotating a crankshaft and a first control rotating body for rotating the driving rotating body relative to each other by applying a relative rotational torque by a rotational operation force applying mechanism are supported to be rotatable relative to a camshaft, and an assembly angle of the camshaft relative to the driving rotating body is changed by an assembly angle changing mechanism interlocked with the relative rotation of the first control rotating body, thereby changing a relative phase angle between the camshaft and the crankshaft,

the assembly angle changing mechanism includes:

a first eccentric circular cam integrated with the first control rotating body in a state of being eccentric from a rotation center axis of the camshaft;

a second eccentric circular cam integrated with the camshaft in a state of being eccentric from a rotation center axis of the camshaft;

a cam guide member for connecting the first eccentric circular cam and the second eccentric circular cam to be capable of relative eccentric rotation, for converting the eccentric rotation of the first eccentric circular cam into the eccentric rotation of the second eccentric circular cam,

accordingly, the assembly angle of the camshaft with respect to the driving rotary member is changed in accordance with the relative eccentric rotation of the second eccentric circular cam with respect to the first eccentric circular cam.

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

a substantially radial guide groove extending in a direction orthogonal to a rotation center axis of the camshaft is provided in the driving rotary body,

the cam guide member is provided with a pair of holding portions and an oblong hole,

the pair of holding portions hold the outer periphery of the first eccentric circular cam from both sides so as to penetrate through the substantially radial guide groove, and are displaced along the substantially radial guide groove by eccentric rotation of the first eccentric circular cam,

the oval hole extends in a direction orthogonal to a direction in which the substantially radial guide groove extends, and displaces the second eccentric circular cam in a direction orthogonal to the direction in which the substantially radial guide groove extends while making sliding contact with the inside.

3. The phase variable device of the engine according to claim 1 or 2,

the rotational operation force imparting mechanism is composed of a first braking mechanism and a reverse rotation mechanism,

the first brake mechanism rotates the first control rotating body relative to the driving rotating body in a retarded angle direction,

the reverse rotation mechanism rotates the first control rotating body relative to the driving rotating body in a lead angle direction.

4. A phase variable device of an engine according to claim 3,

the reverse rotation mechanism is composed of a second control rotation body, a second brake mechanism and a ring mechanism,

the second control rotating body is disposed in a relatively rotatable state with respect to the camshaft,

the second brake mechanism brakes the second control rotating body to rotate in a retarded angle direction relative to the first control rotating body,

the ring mechanism rotates the first control rotating body relative to the driving rotating body in a lead angle direction when the second brake mechanism is operated,

the ring mechanism includes:

a first ring member that is in sliding contact with a first eccentric circular hole formed in the first control rotating body;

a second ring member which is in sliding contact with a second eccentric circular hole formed in the second control rotating body;

an intermediate rotating body having a substantially radial guide groove and rotating integrally with the camshaft;

and a connecting member having both ends projecting from the substantially radial guide groove of the intermediate rotating body, the first ring member and the second ring member being mounted on the projecting both ends so as to be relatively eccentrically rotatable, and being displaceable along the substantially radial guide groove.