JP6676397B2 - Phase change unit and valve timing change device - Google Patents

Description

  The present invention relates to a phase change unit that changes the rotational phase of two rotating bodies, and in particular, to a phase change unit that is applied when changing the opening / closing timing (valve timing) of an intake valve or an exhaust valve of an internal combustion engine, and to the phase change unit. The present invention relates to a valve timing changing device used.

  Conventional valve timing changing devices include a sprocket and an internal gear that rotate around a central axis of a camshaft, an eccentric shaft that is eccentric with respect to the central axis, and are rotatably supported around an eccentric shaft and mesh with the internal gear. The output shaft, which is connected to the camshaft while being connected to the camshaft and engages with the planetary gear, rotates integrally with the camshaft as the planetary gear rotates. A device provided with an electromagnetic unit or the like to be applied is known (for example, see Patent Document 1).

In the above valve timing changing device, an internal planetary gear mechanism, which is a cyclo reduction mechanism, is adopted as a phase changing unit for changing a relative rotation phase between a sprocket and a camshaft.
However, in such an inscribed planetary gear mechanism, since the gear is formed by a combination of a spur gear and a helical gear, there is a limit in increasing the reduction ratio.
In addition, in the above-mentioned inscribed planetary gear mechanism, there is a limit to miniaturization, and backlash occurs due to transmission of gears, and when changing the rotation direction of the electromagnetic unit, collision noise or vibration between gears is generated. Is generated.

Japanese Patent No. 3937164

  The present invention has been made in view of the above circumstances, and aims to simplify the structure, reduce the number of parts, reduce the size of the device, etc., and easily change the phase, For example, when used as a speed reducer, the reduction ratio can be increased, the rotation phase of the two rotating bodies can be easily changed using an external force of an electric motor or the like having a small output, and the backlash can be eliminated. An object of the present invention is to provide a valve timing changing device used.

A phase changing unit according to the present invention is a phase changing unit that changes a relative rotation phase between a first rotating body and a second rotating body that rotate on a common axis, and rotates integrally with the first rotating body. An internal gear, a planetary carrier fixed to the second rotating body and integrally rotating, a rotating member having a worm rotated about the axis, and a twisted position inclined with respect to the axis by the planetary carrier. twist is rotatably supported around an axis see contains at least one planet worm wheel meshed with the worm and the internal gear, planetary worm wheel, a first worm hole which is relatively movably bisected And the second worm wheel, and the first worm wheel and the second worm wheel are disposed between the first worm wheel and the second worm wheel, and the cam rotates in the direction of the torsion axis by the relative rotation between the two. Including a boss loading cam mechanism has a structure.

  According to this configuration, when the phase is not changed, no external force is applied to the rotating member, the internal gear and the planetary worm wheel are locked, and the planetary carrier and the second rotating body are fixed. The rotating body and the second rotating body rotate integrally about a common axis.

  On the other hand, when changing the phase, for example, a driving source such as an electric motor applies an external force to the rotating member, and the rotating member (and the worm) is appropriately rotated in one direction or another direction around the axis. Then, the planet worm wheel rotates in the other direction or one direction around the torsion axis (revolves while rotating), and the planet carrier and the second rotating body move in one direction or the other around the axis with respect to the first rotating body. Rotate in the direction. As a result, the relative rotation phase between the first rotator and the second rotator is changed.

As described above, since the worm gear structure including the worm (screw gear) and the worm wheel (helical gear) is employed as the phase changing unit, the structure is simplified, the number of parts is reduced, and the device is downsized. While the phase can be easily changed.
In particular, since the reduction ratio can be increased by employing the worm gear, the rotating member can be easily rotated using an electric motor or the like having a small output. Therefore, the relative rotation phases of the first rotator and the second rotator can be easily changed.
Further, since the planetary worm wheel is rotatable around the inclined torsional axis forming a predetermined angle with respect to the axis, the planetary carrier can be prevented from self-locking to the worm of the rotating member. Therefore, the revolution of the planetary worm wheel around the axis can be guaranteed.

Here, in a state where the first rotator and the second rotator are rotating in the same direction, the rotation member is appropriately rotated in one direction or the other direction, so that the rotation phase of the second rotator is relative to the first rotator. Can be advanced or delayed.
In other words, one of the rotating bodies can function as a transmission that changes the speed of the other rotating body. In particular, one of the rotating bodies can function as a speed reducer that reduces the speed of the other rotating body. it can.
In particular, since the planetary worm wheel includes the first worm hole, the second worm wheel, and the loading cam mechanism, when the rotating member is rotated, the worm rotates integrally with the rotating member, and the worm and the worm wheel mesh. First, one of the first worm wheel and the second worm wheel meshes with the worm and rotates. At this time, relative rotation occurs between the first worm wheel and the second worm wheel. Due to this relative rotation, the loading cam mechanism exerts a cam action to exert an urging force so as to separate the first worm wheel and the second worm wheel from each other in the direction of the torsion axis.
As a result, the rotation phases of the first worm wheel and the second worm wheel are shifted, and one is pressed against the tooth surface of the worm and the other is pressed against the tooth surface of the internal gear. This eliminates backlash between the planet worm wheel and the worm and between the planet worm wheel and the internal gear.

In the phase change unit having the above configuration, a configuration may be adopted in which a plurality of planetary worm wheels are arranged at equal intervals around the axis.
According to this configuration, the plurality of planetary worm wheels uniformly mesh with the worm and the internal gear around the axis, so that the rotational torque around the axis is evenly transmitted, and the rotational force can be smoothly transmitted.

  In the phase changing unit having the above configuration, the loading cam mechanism faces the first worm groove formed on the facing surface of the first worm wheel facing the second worm wheel, and faces the first worm wheel of the second worm wheel. A configuration including a second cam groove formed on the facing surface and a rolling element interposed between the first cam groove and the second cam groove may be adopted.

  According to this configuration, the first worm wheel and the second worm wheel are in a state where the rolling element is rotatably held between the first cam groove of the first worm wheel and the second cam groove of the second worm wheel. When a relative rotational deviation occurs between the first and second worm wheels, the rolling elements roll along the first and second cam grooves to separate the first and second worm wheels from each other in the direction of the twist axis.

  In the phase changing unit having the above-described configuration, the loading cam mechanism faces the convex cam portion formed on the facing surface of the first worm wheel facing the second worm wheel, and faces the first worm wheel of the second worm wheel. A configuration including a concave cam portion formed on the opposing surface and complementary to the convex cam portion may be employed.

According to this configuration, when the convex cam portion of the first worm wheel and the concave cam portion of the second worm wheel are in complementary contact with each other, the relative position between the first worm wheel and the second worm wheel is reduced. When the rotational displacement occurs, the convex cam portion and the concave cam portion exert a cam action on each other, and separate the first worm wheel and the second worm wheel from each other in the direction of the twist axis.
Here, only the first worm wheel and the second worm wheel do not require a separate component such as a rolling element, so that the structure can be simplified and the number of components can be reduced.

  In the phase change unit having the above configuration, the planet carrier includes a flange portion fixed to the second rotating body and a cylindrical portion rotatably supporting the planet worm wheel, wherein the planet worm wheel defines a torsion axis. A configuration in which the cylindrical portion is rotatably supported by the support shaft and includes a through hole that rotatably receives the planetary worm wheel and a fitting concave portion that positions the support shaft in the twisted position may be employed.

  According to this configuration, the planet carrier can fix the flange portion to the second rotating body using, for example, a bolt. In addition, the planetary worm wheel can be easily assembled to the planet carrier by passing the planetary worm wheel through the through-hole and fitting the spindle and the like into the fitting recess in a state where the support shaft and the like are incorporated in the planetary worm wheel. .

  In the phase changing unit having the above configuration, the first rotating body includes a housing that houses the internal gear, the planet carrier, the rotating member, and the planet worm wheel, and the housing includes a first gear having the internal gear. A configuration including a housing and a second housing connected to the first housing and exposing an end of the rotating member may be adopted.

  According to this configuration, after the internal gear is attached to the inner peripheral surface of the first housing when the internal gear is formed separately, or when the internal gear is integrally formed, the internal gear is kept as it is. The phase change unit can be easily assembled by assembling the planetary carrier and the rotating member in which the planetary worm wheel is pre-installed in the first housing and connecting the second housing to the first housing.

In the phase changing unit having the above configuration, a configuration may be adopted in which the planet carrier is rotatably supported by the housing, and the rotating member is rotatably supported by the planet carrier.
According to this configuration, in a state where the phase changing unit is assembled, the planet carrier is rotatably supported by the housing, and the rotating member is rotatably supported by the planet carrier.
Therefore, when the rotating member and the worm are rotated, the planetary worm wheel revolves while rotating, so that the planetary carrier relatively rotates with respect to the housing.

Then, when the planet carrier is fixed to the second rotating body (for example, camshaft), a state where the housing and the rotating member are rotatably supported with respect to the planet carrier is obtained.
As described above, since the housing and the rotating member are supported by the planet carrier firmly fixed to the second rotating body, the expected function can be guaranteed without causing structural distortion or displacement.

In the phase changing unit having the above configuration, a configuration may be adopted in which the rotating member has a connecting portion that removably connects the driving source through the opening of the second housing.
According to this configuration, the drive source can be detachably connected to the connecting portion of the rotating member through the opening of the second housing.

  The valve timing changing device of the present invention includes a phase changing unit that changes a relative rotation phase between a housing rotor that forms a first rotating body and a camshaft that forms a second rotating body, and an intake valve or a suction valve that is driven by the camshaft. A valve timing changing device for changing the opening / closing timing of an exhaust valve, wherein any one of the phase changing units having the above configuration is employed as a phase changing unit.

According to this configuration, when the phase is not changed, the phase change unit is locked, and when the housing rotor rotates in one direction in conjunction with the crankshaft, the camshaft rotates integrally with the housing rotor. . The rotation of the camshaft drives the intake valve or the exhaust valve to open and close at a predetermined valve timing.
On the other hand, when changing the phase, the rotating member of the phase changing unit is appropriately rotated in one direction or another direction around the axis by a drive source such as an electric motor.
As a result, the rotation of the camshaft relative to the rotation of the housing rotor is changed to the advance side or the retard side, and the opening / closing timing of the intake valve or the exhaust valve is changed.

According to the phase changing unit having the above configuration, the phase can be easily changed while achieving simplification of the structure, reduction of the number of parts, downsizing of the device, and the like.
For example, when used as a reduction gear, the reduction ratio can be increased. Therefore, the rotation phases of the two rotators can be easily changed by using an external force of a small output electric motor or the like.
Further, backlash in the gear mechanism can be eliminated, and collision noise and vibration of the gear can be eliminated.

It is an external appearance perspective view showing the valve timing change device which adopted one embodiment of the phase change unit concerning the present invention. FIG. 2 is an external perspective view of a phase changing unit in which an electric motor and a camshaft are omitted in the valve timing changing device shown in FIG. 1. FIG. 2 is an exploded perspective view of the valve timing changing device shown in FIG. FIG. 3 is a sectional view of the phase change unit shown in FIG. 2. FIG. 3 is an exploded perspective view showing a first housing, a planet carrier, a planet worm wheel, a rotating member having a worm, and the like, which are included in the phase changing unit shown in FIG. 2. FIG. 3 is an exploded perspective view showing a first housing, a planet carrier, a planet worm wheel, a rotating member having a worm, and the like, which are included in the phase changing unit shown in FIG. 2. 3A and 3B show one embodiment of a planetary worm wheel included in the phase changing unit shown in FIG. 2, wherein FIG. 3A is a perspective view thereof, and FIG. 3B is an exploded perspective view thereof. FIGS. 8A and 8B show a loading cam mechanism included in the planetary worm wheel shown in FIG. 7, wherein FIG. 9A is an exploded perspective view as viewed obliquely from the front F, and FIG. FIG. 6 shows another embodiment of the planetary worm wheel included in the phase changing unit shown in FIG. 2, wherein (a) is a perspective view and (b) is an exploded perspective view. 10A and 10B show a loading cam mechanism included in the planetary worm wheel shown in FIG. 9, wherein FIG. 10A is an exploded perspective view as viewed obliquely from the front F and FIG. 10B is an exploded perspective view as viewed obliquely from the rear R.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
As shown in FIG. 1, the valve timing changing device according to this embodiment includes a phase changing unit U for changing a relative rotation phase between the camshaft CS and the sprocket 11a. Here, the camshaft CS forms a second rotating body that rotates in one direction around the axis S (W direction in FIG. 1). The sprocket 11a forms a part of a first rotating body that rotates in one direction around the axis S (W direction in FIG. 1), and is interlocked with the rotation of the crankshaft via a chain.

  The opening / closing timing (valve timing) of the intake valve or the exhaust valve driven by the camshaft CS is changed by appropriately controlling the driving of the phase changing unit U by the electric motor DM as the driving source. ing.

  As shown in FIGS. 1 to 4, the phase changing unit U includes a housing rotor 10 as a first rotating body, a planet carrier 20 fixed to a cam shaft CS, a rotating member 30 rotated around an axis S, a planet carrier. A plurality (three in this case) of planetary worm wheels 40 rotatably supported by the motor 20 are provided.

  As shown in FIGS. 2 to 4, the housing rotor 10 includes a first housing 11 rotatably supported around an axis S, a second housing 12 connected to the first housing portion 11 by bolts b1 and the like. It has.

As shown in FIG. 4, the first housing 11 has a sprocket 11a, a cylindrical portion 11b, a through hole 11c, an annular inner peripheral portion 11d, an annular concave portion 11e, an internal gear 11f, and a plurality of screw holes 11g into which bolts b1 are screwed. Etc. are provided.
The through hole 11c is formed so as to pass the camshaft CS in a non-contact manner.
The annular inner peripheral portion 11d is formed so as to fit a bearing RB1 that rotatably supports the planet carrier 20.
The annular recess 11e is formed so as to fit a bearing SB1 that supports the planetary carrier 20 in the direction of the axis S.
The internal gear 11f is formed on the inner peripheral wall of the cylindrical portion 11b, and is formed as a helical gear having the axis S as a center of rotation so as to mesh with the planetary worm wheel 40 rotating around the torsion axis L. .

As shown in FIG. 4, the second housing 12 includes a cylindrical portion 12a, an annular concave portion 12b, an opening 12c, a plurality of through holes 12d through which bolts b1 pass, and the like.
The cylindrical portion 12a is formed so as to be joined to the first housing 11.
The annular recess 12b is formed so as to fit a bearing SB2 that supports the planet carrier 20 in the direction of the axis S and a bearing SB3 that supports the rotating member 30 in the direction of the axis S.
The opening 12c is formed so as to expose the connecting portion 36 formed at the end of the rotating member 30 and to connect the drive shaft of the electric motor to the connecting portion 36 from outside.

The first housing 11 and the second housing 12 form a housing that houses the internal gear 11f, the planet carrier 20, the rotating member 30, and the planet worm wheel 40.
The first housing 11 and the second housing 12 are assembled in a state in which the planetary worm wheel 40 is installed and the rotating member 30 is screwed into the first housing 11 in which the bearings RB1 and SB1 are installed. The planet carrier 20 is incorporated.
Subsequently, the second housing 12 is connected to the first housing while incorporating the bearings SB2 and SB3, and is fastened by the bolt b1. Thereby, the assembly of the phase changing unit U is completed. Note that another procedure may be used as the assembling procedure.

  As shown in FIGS. 4 to 6, the planet carrier 20 includes a flange portion 21 fixed to the camshaft CS, a cylindrical portion 22 formed continuously with the flange portion 21 and rotatably supporting the planet worm wheel 40, and the like. It has.

As shown in FIG. 4, the flange portion 21 includes a fitting concave portion 21a, a through hole 21b, an annular end surface 21c, a cylindrical outer peripheral surface 21d, an annular concave portion 21e, and the like.
The fitting recess 21a is formed to fit the end of the camshaft CS.
The through hole 21b is formed so as to pass a bolt B for fastening and fixing the planet carrier 20 to the camshaft CS.
The annular end face 21c is formed so as to sandwich the bearing SB1 in cooperation with the annular recess 11e of the first housing 11.
The cylindrical outer peripheral surface 21d is formed so as to sandwich the bearing RB1 in cooperation with the annular inner peripheral portion 11d of the first housing 11.
The annular concave portion 21e is formed so as to abut the bearing SB4.

As shown in FIGS. 4 to 6, the cylindrical portion 22 includes three through holes 22a, fitting recesses 22b formed corresponding to the respective through holes 22a, a cylindrical inner peripheral surface 22c, an annular end surface 22d, and the like. ing.
The through hole 22a is formed so as to receive the planetary worm wheel 40 rotatably around the torsion axis L.
The fitting recess 22b is formed so as to fit and fix a fitting block 45 fixed to both ends of a support shaft 44 that rotatably supports the planet worm wheel 40.
Here, the three through holes 22a and the fitting recesses 22b formed corresponding to the through holes 22a are formed so as to be arranged at equal intervals of 120 degrees around the axis S.
The cylindrical inner peripheral surface 22c is formed so as to fit the bearing RB2.
The annular end face 22d is formed so as to sandwich the bearing SB2 in cooperation with the annular recess 12b of the second housing 12.
The bearings RB1 and RB2 are radial bearings, and the bearings SB1, SB2, SB3 and SB4 are thrust bearings.

According to this, the planetary carrier 20 is fixed to the camshaft CS by fitting the fitting recess 21a of the flange portion 21 to the end of the camshaft CS and screwing the bolt B through the through hole 21b. Is done.
The planetary worm wheel 40 is easily assembled to the planet carrier 20 by passing the planetary worm wheel 40 through the through hole 22a and fitting the fitting blocks 45 fixed to both ends of the support shaft 44 into the fitting recesses 22b. be able to.

  As shown in FIGS. 4 to 6, the rotating member 30 includes a worm 31 having an axis S as a center of rotation, a through hole 32 penetrating on the axis S, an annular end surface 33, a cylindrical outer peripheral surface 34, an annular end surface 35, and a connecting portion. 36 and the like.

The worm 31, as shown in FIGS. 4 to 6, is rotated about an axis S, and is a single or multiple cylindrical screw gear.
As shown in FIG. 4, the through hole 32 is formed around the axis S to have an inner diameter that allows the planet carrier 20 to be fastened to the camshaft CS through the bolt B.
As shown in FIG. 4, the annular end face 33 is formed so as to sandwich the bearing SB4 in cooperation with the annular concave portion 21e of the planet carrier 20.
As shown in FIG. 4, the cylindrical outer peripheral surface 34 is formed so as to sandwich the bearing RB2 in cooperation with the cylindrical inner peripheral surface 22c of the planet carrier 20.
The annular end face 35 is formed so as to sandwich the bearing SB3 in cooperation with the annular recess 12b of the second housing 12.
As shown in FIGS. 4 to 6, the connecting portion 36 is formed in a slit shape so that the drive shaft of the electric motor DM can be detachably connected.

  As shown in FIGS. 5 to 8, the planet worm wheel 40 includes a first worm wheel 41 and a second worm wheel 42 that are relatively movably divided into two, and a first worm wheel 41 and a second worm wheel 42. A loading cam mechanism 43 and the like, which are arranged between them and exert a cam action in the direction of the torsion axis L by the relative rotation between them, are provided.

The planet worm wheel 40 is rotatably supported by a support shaft 44 via two bearings rb and two bearings sb.
The support shaft 44 defines a torsion axis L and is fixed to the planet carrier 20 by fitting blocks 45 fitted at both ends.
The fitting block 45 is formed so as to be fitted and fixed in a fitting concave portion 22b formed in the cylindrical portion 22 of the planet carrier 20.
The angle (torsion angle) θ between the torsion axis L and the axis S is in the range of about 30 ° to 60 °, preferably considering the torsion angle of the planetary worm wheel 40, the advance angle of the worm 31 and the number of threads. It is set in the range of 43 ° to 47 ° (that is, 45 ° ± 2 °).

The two bearings rb are radial bearings, and are fitted in annular concave portions 41c and 42c to support the first worm wheel 41 and the second worm wheel 42 rotatably around the torsion axis L as shown in FIG. I do.
The two bearings sb are thrust bearings, and as shown in FIGS. 5 and 6, are passed through the support shaft 44 and are disposed between the bearing rb and the fitting block 45.
The two bearings sb support the first worm wheel 41 and the second worm wheel 42 in the direction of the torsion axis L when the loading cam mechanism 43 exerts a cam action, and prevent the two sb from moving beyond a predetermined range. It is being regulated.

The first worm wheel 41 includes a toothed portion 41a forming a helical gear meshing with the worm 31, a through hole 41b through which the support shaft 44 passes, an annular concave portion 41c into which the bearing rb is fitted, an opposing surface 41d, and the like.
The second worm wheel 42 includes a toothed portion 42a that forms a helical gear meshing with the worm 31, a through hole 42b through which the support shaft 44 passes, an annular concave portion 42c into which the bearing rb is fitted, an opposing surface 42d, and the like.
The first worm wheel 41 and the second worm wheel 42 are supported by the support shaft 44 so as to be rotatable around the torsion axis L and relatively movable in the direction of the torsion axis L within a predetermined range. ing.

  As shown in FIGS. 7B, 8A, and 8B, the loading cam mechanism 43 includes three first cam grooves 43a formed on the facing surface 41d of the first worm wheel 41, and a second worm. The wheel 42 includes three second cam grooves 43b formed on the facing surface 42d of the wheel 42, and three rolling elements 43c interposed between the first cam grooves 43a and the second cam grooves 43b.

As shown in FIG. 8B, the first cam groove 43a has an arc shape centered on the torsion axis L and has the deepest center position.
As shown in FIG. 8A, the second cam groove 43b is formed in an arc shape centered on the torsion axis L and formed at the center at the deepest position.
As shown in FIG. 7A, the first cam groove 43a and the second cam groove 43b are in a state where there is no relative rotational phase shift between the first worm wheel 41 and the second worm wheel 42, that is, the tooth row. In a state where the portions 41a and 42a are arranged as one tooth row, the center positions coincide with each other, and the rolling elements 43c are formed so as to be positioned at the deepest portion.
As shown in FIGS. 7 (b), 8 (a) and 8 (b), the rolling element 43c forms a sphere and is rotatably sandwiched between the first cam groove 43a and the second cam groove 43b.

The operation of the loading cam mechanism 43 included in the planet worm wheel 40 will be described.
When the rotating member 30 is rotated around the axis S, the worm 31 rotates integrally with the rotating member 30. Here, due to the meshing relationship between the worm 31 and the worm wheels 41 and 42, first, one of the first worm wheel 41 and the second worm wheel 42 meshes with the worm 31 and rotates.

At this time, relative rotation occurs between the first worm wheel 41 and the second worm wheel 42. Due to this relative rotation, the first cam groove 43a and the second cam groove 43b relatively rotate and move, and the rolling element 43c rolls from a deep portion to a shallow portion of the first cam groove 43a and the second cam groove 43b. In the direction of the torsion axis L, a cam action is provided so as to move away from each other.
Thereby, the first worm wheel 41 and the second worm wheel 42 are urged while being moved in a direction away from each other in the direction of the torsion axis L.

As a result, the rotation phases of the first worm wheel 41 and the second worm wheel 42 are shifted, and one is pressed against the tooth surface of the worm 31 and the other is pressed against the tooth surface of the internal gear 11f.
Thus, backlash between the planet worm wheel 40 and the worm 31 is eliminated , and backlash between the planet worm wheel 40 and the internal gear 11f is eliminated.

Worm gear (worm 31, the worm wheel 40) having the above-described construction in and gear mechanism composed of the internal gear 11f, the number of teeth of the worm 31 (Article number) Za, if the number of teeth of the internal gear 11f was Zc , The reduction ratio r is represented by r = Za / (1 + Zc).
Therefore, by setting the number of teeth (number of teeth) of the worm 31 to be small (for example, Za = 1), a larger reduction ratio can be obtained as compared with a planetary gear mechanism using a normal spur gear.
That is, a high reduction ratio can be obtained while achieving downsizing of the device, reduction in the number of parts, reduction in cost, and the like.
Therefore, the influence of the torque fluctuation input from the camshaft CS becomes difficult to propagate to the drive source such as the electric motor, and the controllability from the drive source is improved.

Next, the operation of the phase changing unit U will be described.
First, when the phase is not changed, that is, when the valve timing is not changed, no rotational driving force is exerted on the rotating member 30.
Therefore, the planet worm wheel 40 and the internal gear 11f are locked at a position where they mesh with each other.
Further, the worm 31 and the planet worm wheel 40 are locked at a position where they are meshed with each other.
Thereby, the camshaft CS and the housing rotor 10 rotate integrally in one direction (W direction in FIG. 1, that is, CW direction) around the axis S.

On the other hand, when the phase is changed, that is, when the valve timing is changed, a rotational driving force is exerted on the rotating member 30 by the electric motor DM.
For example, when the rotating member 30 is relatively rotated in one direction around the axis S (CW direction in FIG. 1), the worm 31 also rotates in one direction (CW direction in FIG. 1), and the planet worm wheel 40 Revolves in one direction (CW direction in FIG. 1) while rotating.

Here, since the planetary worm wheel 40 is held by the planetary carrier 20, the planetary carrier 20 rotates in one direction (the CW direction in FIG. 1), and the camshaft CS to which the planetary carrier 20 is fixed moves to one side. In the direction (CW direction in FIG. 1).
That is, when the rotating member 30 is continuously rotated in one direction (CW direction) a plurality of times, the rotation phase of the camshaft CS is advanced with respect to the housing rotor 10, and the rotation of the intake valve or the exhaust valve is performed. The opening / closing timing is changed to the advance side.

  On the other hand, when the rotating member 30 is relatively rotated in the other direction around the axis S (CCW direction in FIG. 1), the worm 31 also rotates in the other direction (CCW direction in FIG. 1), and the planet worm wheel 40 Revolves in the other direction (CCW direction in FIG. 1) while rotating.

Here, since the planetary worm wheel 40 is held by the planetary carrier 20, the planetary carrier 20 rotates in the other direction (the CCW direction in FIG. 1), and the camshaft CS to which the planetary carrier 20 is fixed moves to the other side. (The CCW direction in FIG. 1).
That is, by rotating the rotating member 30 continuously plural times in the other direction (CCW direction), the rotation phase of the camshaft CS is delayed with respect to the housing rotor 10, and the rotation of the intake valve or the exhaust valve is reduced. The opening / closing timing is changed to the retard side.

As described above, according to the phase changing unit U having the above-described configuration, the structure of the worm gear including the worm 31 (screw gear) and the planetary worm wheel 40 (helical gear) is employed. The phase can be easily changed while achieving a reduction in the number of parts and a reduction in the size of the device.
In particular, since the reduction ratio can be increased by using the worm gear, the rotating member 30 can be easily rotated using the electric motor DM having a small output. Therefore, the relative rotation phase between the housing rotor 10 and the camshaft CS can be easily changed.

  Further, since the planet worm wheel 40 is rotatable around the inclined torsion axis L forming a predetermined angle θ with respect to the axis S, the planet carrier 20 can be prevented from self-locking to the worm 31. Therefore, the revolution of the planet worm wheel 40 around the axis S can be guaranteed.

  In particular, since the planet worm wheel 40 includes the first worm wheel 41 and the second worm wheel 42 divided into two, and the loading cam mechanism 43 disposed between the two, the space between the planet worm wheel 40 and the worm 31 and Backlash between the planet worm wheel 40 and the internal gear 11f can be eliminated. For this reason, it is possible to prevent collision noise and vibration between teeth.

  Further, since the three planetary worm wheels 40 are arranged at equal intervals around the axis S and mesh with the worm 31 and the internal gear 11f evenly, the rotational torque around the axis S is evenly transmitted, and the rotational force is smoothed. Can be transmitted.

Further, in a state where the phase changing unit U is assembled, the planet carrier 20 is rotatably supported by the housing rotor 10, and the rotating member 30 is rotatably supported by the planet carrier 20.
When the planet carrier 20 is fixed to the camshaft CS, a state where the housing rotor 10 and the rotating member 30 are rotatably supported by the planet carrier 20 is obtained.
As described above, the housing rotor 10 and the rotating member 30 are supported on the planet carrier 20 which is firmly fixed to the camshaft CS as the second rotating body, so that the expected distortion can be achieved without causing structural distortion or displacement. Function can be guaranteed.

  FIGS. 9 and 10 show another embodiment of the loading cam mechanism included in the planetary worm wheel 40. The same components as those in the above-described embodiment are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIGS. 9 and 10, the planet worm wheel 40 according to this embodiment is disposed between the first worm wheel 41 and the second worm wheel 42, and between the first worm wheel 41 and the second worm wheel 42. A loading cam mechanism 43 'which exerts a cam action in the direction of the torsion axis L by the relative rotation between the two is provided.

  Here, the loading cam mechanism 43 ′ includes a convex cam portion 43 a ′ formed on the facing surface 41 d of the first worm wheel 41 and a convex cam portion 43 a ′ formed on the facing surface 42 d of the second worm wheel 42. And a concave cam portion 43b 'having a complementary shape.

As shown in FIG. 10 (b), the convex cam portion 43a 'is formed in an arc shape centered on the torsion axis L and has an inclined surface whose center position is most protruded.
As shown in FIG. 10A, the concave cam portion 43b 'is formed in an arc shape centered on the torsion axis L and has an inclined surface whose center position is deepest.

  As shown in FIG. 9A, the convex cam portion 43a ′ and the concave cam portion 43b ′ are in a state where there is no relative rotation phase shift between the first worm wheel 41 and the second worm wheel 42, that is, In a state where the row portions 41a and 42a are arranged as one tooth row, the center positions are aligned with each other, and the row portions 41a and 42a are formed so as to be in contact with each other so as to be complementary to each other.

  In a state where the convex cam portion 43a 'of the first worm wheel 41 and the concave cam portion 43b' of the second worm wheel 42 are in contact with each other so as to be complementary to each other, the gap between the first worm wheel 4 and the second worm wheel 42 When the relative rotational deviation occurs, the convex cam portion 43a 'and the concave cam portion 43b' relatively rotate and move the first worm wheel 41 and the second worm wheel 42 away from each other in the direction of the twist axis L. Exerts such a cam action.

As a result, the rotation phases of the first worm wheel 41 and the second worm wheel 42 are shifted, and one is pressed against the tooth surface of the worm 31 and the other is pressed against the tooth surface of the internal gear 11f.
Thus, backlash between the planet worm wheel 40 and the worm 31 is eliminated, and backlash between the planet worm wheel 40 and the internal gear 11f is eliminated.
Here, only the first worm wheel 41 and the second worm wheel 42 do not require the rolling element 43c as in the above-described embodiment, so that the structure can be simplified and the number of parts can be reduced.

  In the above-described embodiment, the case where the internal gear 11f is formed integrally with the inner peripheral wall of the cylindrical portion 11b of the first housing 11 has been described. However, the present invention is not limited to this. A structure in which the null gear is fixed to the inner peripheral wall of the first housing may be adopted.

  In the above embodiment, the case where three planetary worm wheels 40 are adopted as the planetary worm wheel has been described. However, the present invention is not limited to this, and one or two planetary worm wheels may be adopted, Also, four or more planetary worm wheels may be employed.

  In the above-described embodiment, the configuration has been described in which the planetary worm wheel 40 includes the first worm wheel 41 and the second worm wheel 42, which are divided into two, and the loading cam mechanisms 43 and 43 '. However, the present invention is not limited to this. If there is no particular problem with backlash or the like, a planetary worm wheel composed of a single worm wheel may be employed.

  In the above embodiment, the phase change unit U as the speed reducer applied to the valve timing change device is shown as the phase change unit. However, the present invention is not limited to this. In a mechanism and a device that need to change the phase, the present invention can be applied also as a speed reducer, a speed increasing device, a transmission, or the like.

CS camshaft (second rotating body)
S axis L torsion axis DM Electric motor (drive source)
U Phase change unit RB1, RB2 Bearing (radial bearing)
SB1, SB2, SB3, SB4 Bearing (Thrust bearing)
b1, B bolt 10 Housing rotor (first rotating body)
11 1st housing (housing)
11a Sprocket 11b Cylindrical portion 11c Through hole 11d Annular inner peripheral portion 11e Annular concave portion 11f Internal gear 11g Screw hole 12 Second housing (housing)
12a cylindrical portion 12b annular concave portion 12c opening portion 12d through hole 20 planet carrier 21 flange portion 21a fitting concave portion 21b through hole 21c annular end surface 21d cylindrical outer peripheral surface 21e annular concave portion 22 cylindrical portion 22a through hole 22b fitting concave portion 22c cylindrical inner peripheral surface 22d Annular end surface 30 Rotating member 31 Worm 32 Through hole 33 Annular end surface 34 Cylindrical outer peripheral surface 35 Annular end surface 36 Connecting portion (end)
40 planet worm wheel 41 first worm wheel 41a toothed portion 41b through hole 41c annular recess 41d facing surface 42 second worm wheel 42a toothed portion 42b through hole 42c annular recess 42d facing surface 43, 43 'loading cam mechanism 43a first Cam groove 43a 'Convex cam portion 43b Second cam groove 43b' Concave cam portion 43c Rolling member 44 Support shaft 45 Fitting block rb Bearing (radial bearing)
sb bearing (thrust bearing)

Claims (9)

A phase changing unit that changes a relative rotation phase between a first rotating body and a second rotating body that rotate on a common axis,
An internal gear that rotates integrally with the first rotating body;
A planetary carrier fixed to the second rotating body and integrally rotating,
A rotating member having a worm that is rotated about the axis,
Wherein is rotatably supported around an axis twist in inclined twisted position with respect to the axis by a planet carrier, viewed contains at least one planet worm wheel, the meshing with the worm and the internal gear,
The planetary worm wheel is disposed between a first worm hole and a second worm wheel, which are divided into two parts so as to be relatively movable, and the torsion is generated by the relative rotation of the first worm wheel and the second worm wheel. Including a loading cam mechanism that exerts a cam action in the direction of the axis,
A phase changing unit, characterized in that: A plurality of the planetary worm wheels are arranged at equal intervals around the axis,
The phase change unit according to claim 1, wherein: The loading cam mechanism has a first cam groove formed on a surface of the first worm wheel facing the second worm wheel, and a loading cam mechanism formed on a surface of the second worm wheel facing the first worm wheel. A second cam groove, and a rolling element interposed between the first cam groove and the second cam groove.
The phase changing unit according to claim 1, wherein: The loading cam mechanism has a convex cam portion formed on a facing surface of the first worm wheel facing the second worm wheel, and a loading cam portion formed on a facing surface of the second worm wheel facing the first worm wheel. Including a concave cam portion that is formed complementary to the convex cam portion,
The phase changing unit according to claim 1, wherein: The planet carrier includes a flange portion fixed to the second rotating body, and a cylindrical portion rotatably supporting the planet worm wheel,
The planetary worm wheel is rotatably supported by a spindle that defines the torsion axis,
The cylindrical portion includes a through hole that rotatably receives the planetary worm wheel and a fitting concave portion that positions the support shaft at the twist position.
Phase changing unit according to any one claims 1 to 4, characterized in that. The first rotating body includes a housing that houses the internal gear, the planet carrier, the rotating member, and the planet worm wheel,
The housing includes a first housing provided with the internal gear, and a second housing connected to the first housing and exposing an end of the rotating member.
The phase changing unit according to any one of claims 1 to 5, wherein The planet carrier is rotatably supported by the housing,
The rotating member is rotatably supported by the planet carrier,
The phase change unit according to claim 6 , wherein: The rotating member has a connecting portion that detachably connects a driving source through an opening of the second housing,
The phase changing unit according to claim 6 or 7 , wherein: A phase change unit that changes a relative rotation phase between a housing rotor that forms the first rotating body and a camshaft that forms the second rotating body, and changes an opening / closing timing of an intake valve or an exhaust valve driven by the camshaft; A valve timing changing device,
The phase change unit is the phase change unit according to any one of claims 1 to 8 ,
A valve timing changing device characterized by the above-mentioned.

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