WO2020039689A1

WO2020039689A1 - Valve timing control device for internal combustion engine

Info

Publication number: WO2020039689A1
Application number: PCT/JP2019/022272
Authority: WO
Inventors: 淳史山中
Original assignee: 日立オートモティブシステムズ株式会社
Priority date: 2018-08-23
Filing date: 2019-06-05
Publication date: 2020-02-27
Also published as: CN112840106A; JP7085629B2; CN112840106B; JPWO2020039689A1

Abstract

The device of the present invention comprises a bearing recess 10 that is provided in a part of the inner peripheral surface of a sprocket body 1a on a holding plate 8 side and has a sliding bearing surface 10a formed on the bottom surface, and a journal portion 11 that is provided to protrude radially outward from the outer peripheral surface of a disc-shaped body 9a, fits into the bearing recess 10 and slides by the outer peripheral surface on the sliding bearing surface 10a. Axial loads F1, F2 are received by an inner side surface 10b of the bearing recess 10 and an inner side surface 8f of an inner peripheral portion 8b of the holding plate 8 in a state where both end surfaces 11e, 11f of a journal portion 11 are sandwiched from both sides in the axial direction. As a result, the device can be reduced in size while suppressing the inclination of a drive rotor relative to a driven rotor.

Description

Valve timing control device for internal combustion engine

The present invention relates to a valve timing control device for an internal combustion engine that controls, for example, the opening and closing timing of an intake valve and an exhaust valve.

As a valve timing control device for an internal combustion engine, a device described in Patent Document 1 below is known.

In this valve timing control device, the drive rotating body includes a sprocket portion having external teeth around which a chain is wound around an outer periphery, a cylindrical housing portion disposed at a front end of the sprocket portion, and a housing portion. And a cylindrical gear portion disposed at the front end of the gear. The sprocket, the housing part and the gear part are connected to each other by a plurality of bolts from the axial direction.

には On the inner peripheral side of the housing portion, a driven rotating body having a bottomed cylindrical shape is disposed so as to be relatively rotatable. In the driven rotating body, a sliding surface is formed on the outer peripheral surface of the cylindrical peripheral wall so as to slide in surface contact with the inner peripheral surface of the housing portion.

Further, in the driven rotor, the outer surface of the disc-shaped bottom wall abuts against the concave bottom surface of the sprocket portion from the axial direction, while the annular distal end surface of the cylindrical peripheral wall abuts on the rear end surface of the gear portion. It is regulated in contact. Thus, the driven rotator is positioned in the axial direction, and the driving rotator is supported by the sliding surface of the driven rotator. Further, the driven rotator suppresses a radial inclination of the drive rotator caused by a tension of the chain during driving.

JP-A-2017-172442 (FIG. 2)

However, in the valve timing control device described in Patent Document 1, as described above, the driven rotor is axially positioned by the sprocket portion and the gear portion of the drive rotor, The distance from the outer surface of the bottom wall to the end surface of the cylindrical peripheral wall, that is, the axial length of the sliding surface is increased.

Therefore, since the axial length of the sliding surface is long, the radial inclination of the driving rotating body during driving can be suppressed, but the axial length of the device may be large.

The present invention has been devised in view of the above-mentioned conventional technical problem, and provides a valve timing control apparatus for an internal combustion engine that can reduce the size of the apparatus while suppressing the inclination of the driving rotating body with respect to the driven rotating body. For one purpose.

As one of preferred embodiments, in particular, a phase change mechanism that reduces the rotation of the motor output shaft of the electric motor by a speed reduction mechanism to change the relative rotation phase between the driving rotator and the driven rotator, and A sliding bearing surface provided on a periphery, a journal portion provided to protrude radially outward from an outer periphery of the driven rotating body, an outer peripheral surface sliding on the sliding bearing surface, and a journal portion provided on the driving rotating body; A first axial direction restricting portion and a second axial direction restricting portion for restricting the axial movement of the journal portion with the journal portion sandwiched from both sides in the axial direction are provided.

According to a preferred embodiment of the present invention, the size of the apparatus can be reduced while suppressing the inclination of the driving rotating body.

1 is a partial longitudinal sectional view of a valve timing control device according to an embodiment of the present invention. FIG. 2 is an exploded view showing main constituent members provided in the present embodiment. It is a principal part enlarged view of FIG. FIG. 2 is a view on arrow A in FIG. 1. FIG. 2 is a view taken in the direction of arrow B in FIG. 1. FIG. 2 is a sectional view taken along line CC of FIG. 1. FIG. 2 is a sectional view taken along line DD of FIG. 1. It is a schematic diagram which shows the length relationship of each part of a bearing recessed part and a journal part provided to this embodiment, and is an action explanatory view of an axial load mainly on the journal part when the sprocket is inclined.

Hereinafter, an embodiment of a valve timing control device for an internal combustion engine according to the present invention will be described in detail with reference to the drawings. In the present embodiment, the valve timing control device is applied to the intake side, but may be applied to the exhaust side.
[Embodiment]
FIG. 1 is a partial longitudinal sectional view showing a valve timing control device according to the present embodiment, FIG. 2 is an exploded view showing main constituent members provided in the present embodiment, and FIG. 3 is a main part of the present embodiment shown in FIG. FIG. 4 is an enlarged view of a portion, and FIG.

As shown in FIGS. 1 and 2, the valve timing control device is rotatably supported on a timing sprocket 1 (hereinafter, referred to as a sprocket 1) as a driving rotating body and on a cylinder head 01 via a bearing 02. A camshaft 2 and a phase changing mechanism 3 disposed between the sprocket 1 and the camshaft 2 to change the relative rotational phase between the two, 1 and 2, according to the operating state of the engine.

The sprocket 1 is formed in a ring-like shape entirely of an iron-based metal, which is a metal material, and is provided integrally with an annular sprocket main body 1a and an outer periphery of the sprocket main body 1a, and is wound around the sprocket. And a gear portion 1b which is an external tooth that receives a rotational force from a crankshaft of the internal combustion engine via a timing chain.

A chain case (not shown) connected to the cylinder block and the cylinder head 01 of the internal combustion engine is provided on the outer periphery of the sprocket 1.

円 At the front end side of the sprocket main body 1a, an annular internal tooth forming portion 5 which constitutes a part of a speed reduction mechanism 13 described later is integrally provided. The internal tooth forming portion 5 is integrally connected to the sprocket main body 1a from the direction of the rotation axis, and has a plurality of corrugated internal teeth 5a formed on the inner periphery.

The sprocket main body 1a has a sliding bearing mechanism 6 provided between an inner peripheral surface thereof and an outer peripheral surface of a driven member 9 which will be described later, which is a driven rotating body fixed to one end 2a of the camshaft 2 in the rotation axis direction. I have. The sliding bearing mechanism 6 rotatably supports the sprocket 1 on the outer periphery of the driven member 9 (camshaft 2). A specific description of the sliding bearing mechanism 6 will be described later.

保持 Furthermore, a holding plate 8 as a plate member is fixed to the rear end face of the sprocket main body 1a on the side opposite to the internal teeth forming section 5. As shown in FIGS. 2 to 4, the holding plate 8 is formed in an annular shape by a plate material of an iron-based metal, which is a metal material, and has an outer diameter substantially equal to the outer diameter of the sprocket body 1a. In addition, the holding plate 8 is arranged such that an inner peripheral portion 8b formed on the side of the center hole 8a formed at the center covers one end opening of the bearing recess 10 of the sliding bearing mechanism 6 described later on the camshaft 2 side. In the inner peripheral portion 8b, a portion serving as a hole edge of the central hole 8a is located inside the tooth bottom surface of the internal teeth 5a of the internal tooth forming portion 5.

保持 Further, the holding plate 8 is integrally provided with a stopper projection 8c that protrudes radially inward, that is, toward the center axis direction, at a predetermined position on the inner peripheral edge of the center hole 8a. The stopper convex portion 8c is formed in a substantially inverted trapezoidal shape, and the distal end surface is formed in an arc shape along an arc-shaped inner peripheral surface of a stopper concave groove 9f of a fixed end portion 9b of the driven member 9 described later. .

FIG. 5 is a view on arrow B in FIG.

フロント Furthermore, a front plate 15 serving as a cover is provided on the front end face of the sprocket 1 on the side of the internal teeth forming section 5. As shown in FIGS. 1 to 3 and 5, the front plate 15 is formed by, for example, stamping an iron-based metal plate into an annular shape by press molding, and the thickness t of the front plate 15 is the thickness t1 of the holding plate 8. It is set smaller than. The front plate 15 has an insertion hole 15a through which an eccentric shaft 21 to be described later is inserted.

Six

bolt insertion holes

1c and 15b, through which a plurality of (six in this embodiment) bolts 7 are inserted, are formed in the outer peripheral portions of the sprocket main body 1a including the internal tooth forming portion 5 and the front plate 15 in substantially the circumferential direction. The through holes are formed at the respective intervals. The holding plate 8 has six female screw holes 8d at the positions corresponding to the

bolt insertion holes

1c and 15b, into which the male screw portions 7a at the tips of the bolts 7 are screwed.

The two small bolt holes 1c of the sprocket body 1a and the two corresponding female screw holes 8d of the holding plate 8 have respective small side holes 1d into which the two positioning pins 30a and 30b are inserted. 8e are provided two by two. Thus, the holding plate 8 is positioned relative to the sprocket 1 in the circumferential direction and the axial direction.

The camshaft 2 has two drive cams per cylinder for opening an intake valve (not shown) on the outer periphery. Further, the camshaft 2 is integrally provided with a flange portion 2b for positioning in the axial direction via a bearing 02 at one end of the camshaft 2 on the side of the phase changing mechanism 3 in the rotational axis direction. The camshaft 2 has a female screw 2c formed in the axial direction inside the one end 2a, and the driven member 9 is fastened and fixed in the axial direction by a cam bolt 14 screwed to the female screw 2c. Further, a pin (not shown) for positioning, which performs positioning with respect to the driven member 9 in the rotation direction, is press-fitted and fixed to the front end of the one end 2a of the camshaft 2 from the rotation axis direction. The pin is inserted into a positioning hole 9e formed on the inner peripheral side of the front end face of the driven member 9 to perform positioning.

6 is a cross-sectional view taken along line CC of FIG. 1, and FIG. 7 is a cross-sectional view taken along line DD of FIG.

The driven member 9 is integrally formed of an iron-based metal, and is formed on the disk-shaped main body 9a and the rear end side (camshaft 2 side) of the disk-shaped main body 9a as shown in FIGS. And an annular fixed end 9b.

The disc-shaped main body 9a is provided integrally with a journal portion 11 constituting a part of the slide bearing mechanism 6 on the outer peripheral surface, and the shaft portion 14b of the cam bolt 14 is inserted in the direction of the internal axis including the fixed end portion 9b. A bolt insertion hole 9c is formed to penetrate.

The fixed end 9b has a certain thickness, protrudes from the disc-shaped main body 9a in the direction of the camshaft 2, and has an outer diameter set to be substantially the same as that of the disc-shaped main body 9a. The fixed end 9b has an annular fitting groove 9d in which the tip of the one end 2a of the camshaft 2 fits substantially at the center of the outer surface on the camshaft 2 side (outer side of the bolt insertion hole 9c). Is formed. A positioning hole 9e into which a positioning pin (not shown) is inserted from the axial direction is formed in the bottom surface of the fitting groove 9d.

固定 Further, the fixed end portion 9b is provided with a stopper concave groove 9f on the outer peripheral surface along which the stopper convex portion 8c of the holding plate 8 is engaged, along the circumferential direction. The stopper groove 9f is formed in an arc shape having a predetermined length in the circumferential direction. Both side surfaces of the stopper convex portion 8c rotated in the arc-shaped length range of the stopper concave groove 9f come into contact with respective circumferentially opposed surfaces. Thus, the relative rotation position of the cam shaft 2 on the maximum advance side or the maximum retard side with respect to the timing sprocket 1 is mechanically regulated.

The driven member 9 is fixed to the one end 2a of the camshaft 2 from the axial direction by the cam bolt 14 in a state where the tip of the one end 2a of the camshaft 2 is fitted in the fitting groove 9d from the axial direction. ing.

As shown in FIG. 3, the sliding bearing mechanism 6 is provided on an annular bearing recess 10 formed on the inner peripheral surface of the sprocket main body 1a and on the outer peripheral surface of the disc-shaped main body 9a. It has a journal portion 11 disposed inside and the holding plate 8 covering one end opening of the bearing recess 10.

The bearing recess 10 is arranged and formed only on the inner peripheral surface side of the sprocket main body 1a close to the camshaft 2 side without extending from one side surface of the sprocket main body 1a on the holding plate 8 side to the internal tooth forming portion 5. As shown in FIG. 1, the bearing recess 10 has a substantially rectangular cross-sectional shape along the radial direction from the rotation axis of the sprocket 1, and a part of the recess 10 is formed at the position where each gear portion 1b is formed. And are arranged to overlap in the axial direction.

Furthermore, the bearing recess 10 has a sliding bearing surface 10a formed on an annular bottom surface. In the bearing recess 10, an inner side surface 10b provided on the other end side opposite to the holding plate 8 in the axial direction is notched at a substantially right angle in a radial direction from the sliding bearing surface 10a. As described above, the other end of the bearing concave portion 10 is opened at the other end on the camshaft 2 side and released to the outside, and the opened other end is opened by the inner side surface 8f of the inner peripheral portion 8b of the holding plate 8. Covered.

(3) As shown in FIG. 3, the journal portion 11 protrudes radially outward from the outer peripheral surface of the disk-shaped main body 9a, and is formed in a rectangular shape having a cross-sectional shape substantially similar to the cross-sectional shape of the bearing recess 10. Also, since the bearing recess 10 axially overlaps with each gear portion 1b, this journal portion 11 is also partially overlapped with each gear portion 1b of the sprocket 1 in the axial direction.

ジャーナル Furthermore, the journal portion 11 has

annular grooves

11b and 11c formed on both sides in the axial direction of the base portion 11a, which is a connection portion with the disc-shaped main body 9a. The journal portion 11 has an annular outer peripheral surface 11d slidable over the entire sliding bearing surface 10a of the bearing recess 10. Each of the

annular grooves

11 b and 11 c prevents the journal portion from contacting the inner surface 8 f of the holding plate 8 and the inner surface 10 b of the bearing recess 10 when the driven member 9 rotates.

The journal portion 11 is configured such that one end surface 11e on the side of the front plate 15 in the axial direction is slidable on the inner surface 10b of the bearing recess 10. The inner side surface 10b of the bearing recess 10 serves as a first axial direction restricting portion that restricts one thrust movement by contacting one end surface 11e of the journal portion 11 when the sprocket 1 is tilted.

The journal 11 is configured such that the other end surface 11f on the holding plate 8 side in the axial direction can slide on the inner surface 8f of the inner peripheral portion 8b of the holding plate 8. The inner side surface 8f of the holding plate 8 is a second axial direction restricting portion that restricts the other thrust movement by contacting the other end surface 11f of the journal portion 11 when the sprocket 1 is tilted.

FIG. 8 is a schematic view showing the relationship between the lengths of the bearing recess 10 and the journal section 11, and is an explanatory view of the action of axial loads F1 and F2 mainly on the journal section 11 when the sprocket 1 is inclined. .

That is, as shown in FIG. 8, an axial width A1 between an inner surface 10b of the bearing recess 10 as the first axial direction regulating portion and an inner surface 8f of the holding plate 8 as the second axial direction regulating portion is provided. When the diameter of the inner peripheral surface of the slide bearing surface 10a is A2, the axial width between both

end surfaces

11e and 11f of the journal portion 11 is B, and the diameter of the outer peripheral surface of the journal portion 11 is D, Is set to satisfy the equation.

Ca = A1-B
Cr = A2-D
Ca <Cr ・ (D / B)
Here, Ca is an axial clearance (gap) between the axial width A1 and the axial width B of the journal portion 11. Cr is a radial clearance (gap) between the outer peripheral surface (diameter D) of the journal portion 11 and the inner peripheral surface (diameter A2) of the sliding bearing surface 10a of the bearing recess 10.

In the present embodiment, the axial clearance Ca is set to be smaller than the radial clearance Cr × (diameter D / axial width B).

As shown in FIG. 1, the cam bolt 14 has a needle roller 25a of a needle bearing 25 rotatably held on an outer peripheral surface of a head 14a. A male screw portion 14c that is screwed to the female screw portion 2c of the camshaft 2 is formed on the outer periphery of the distal end portion of the shaft portion 14b.

As shown in FIGS. 1 and 2, the phase changing mechanism 3 includes an electric motor 12 disposed on the front end side of the fixed end 9 b of the driven member 9, and reduces the rotation speed of the electric motor 12 to reduce the rotational speed of the camshaft 2. And a speed reduction mechanism 13 for transmitting the power to the motor.

The electric motor 12 is a so-called brushless DC motor. In short, the electric motor 12 has a bottomed cylindrical motor housing 16 fixed to a chain case, and is provided at the rear end of the motor housing 16 so as to be internally provided. A motor stator accommodating a stator coil and the like; a motor output shaft 17 arranged on the inner peripheral side of the stator coil; a cylindrical permanent magnet fixed to the outer periphery of the motor output shaft 17; 1 and a power supply mechanism 18 provided at a front end opposite to the front side.

The motor housing 16 is formed substantially in a cup shape, and has a through hole through which the motor output shaft 17 penetrates substantially at the center of the front end (bottom wall). On the other hand, a flange 16a protruding radially outward is provided on the outer periphery of the rear end. The flange portion 16a has three bracket pieces 16b integrally provided at a position of about 120 ° in the circumferential direction. A bolt insertion hole 16c through which a bolt coupled to a chain case (not shown) is inserted is formed through the three bracket pieces 16b.

Furthermore, three different bolt insertion holes into which the three bolts 31 are inserted are formed between the bracket pieces 16b in the circumferential direction of the flange portion 16a. The power supply mechanism 18 is connected to the motor housing 16 by each bolt 31. The number of the bolt insertion holes 16c and the bolts 31 can be further increased.

The motor stator is formed integrally with a resin portion of a synthetic resin material, and a stator coil is molded and fixed inside.

The power supply mechanism 18 is formed in a box shape from a synthetic resin material. Inside the power supply mechanism 18, an energizing circuit such as a bus bar for supplying power to the electric motor 12, a rotation sensor for detecting the rotational position of the motor output shaft 17, and the like are accommodated. In the power supply mechanism 18, a power supply connector 18a electrically connected to a power supply circuit and a signal connector (not shown) are provided integrally on an outer peripheral portion.

The power supply connector 18a has an internal terminal connected to a battery, which is a power supply, via a female terminal to a control unit (not shown). On the other hand, the signal connector has an internal terminal (not shown) connected to the control unit via a female terminal, and outputs a rotation angle signal detected by the rotation sensor to the control unit.

The motor output shaft 17 is formed of a metal material in a cylindrical shape, and an intermediate member 20 that constitutes a part of an Oldham coupling 19 that is a coupling mechanism connected to the reduction mechanism 13 is provided on a distal end side of the reduction mechanism 13. ing. The intermediate member 20 has a cylindrical base 20a fixed to the distal end 17a of the motor output shaft 17, and two

transmission keys

20b and 20c provided integrally on the outer peripheral surface of the cylindrical base 20a. ing.

The cylindrical base portion 20a is formed of a metal material, for example, an iron-based metal, and has a fixing hole 20d in the center through which the distal end portion 17a of the motor output shaft 17 is inserted and fixed. Further, the cylindrical base 20a has two flat portions having a width across flats at a position of about 180 ° on the outer peripheral surface.

伝達 Each transmission key 20b, 20c is formed in a substantially rectangular block shape, and protrudes radially outward from two flat portions of the cylindrical base 20a.

The control unit detects the current engine operating state based on information signals from various sensors such as a crank angle sensor, an air flow meter, a water temperature sensor, and an accelerator opening sensor not shown, and controls the engine based on this. Is going. The control unit controls the rotation of the motor output shaft 17 by energizing the coil unit based on the information signals and the rotation position detection mechanism, and controls the relative rotation phase of the camshaft 2 with respect to the timing sprocket 1 by the reduction mechanism 13. Is controlled.

As shown in FIG. 1, the speed reduction mechanism 13 is provided separately from the electric motor 12 in the axial direction, and each component is accommodated and arranged inside the sprocket 1 between the holding plate 8 and the front plate 15. ing.

More specifically, as shown in FIGS. 1 to 3 and 7, the speed reducing mechanism 13 includes a cylindrical eccentric shaft 21 partially disposed inside the sprocket body 1a, A ball bearing 22 provided on the outer periphery, a roller 23 provided on the outer periphery of the ball bearing 22 and being a rolling member rotatably held in each of the internal teeth 5 a of the internal tooth forming section 5, Mainly comprises a retainer 24 which is a transmitting portion (protruding portion) that allows radial movement while holding the in the rolling direction, and the above-described driven member 9 integrated with the retainer 24.

The eccentric shaft 21 includes an eccentric shaft portion 21a disposed on an outer periphery of a needle bearing 25 provided on an outer periphery of the head portion 14a of the cam bolt 14, and a large-diameter cylindrical portion 21b provided on the electric motor 12 side of the eccentric shaft portion 21a. ,have.

The thickness of the eccentric shaft portion 21 a in the circumferential direction changes in thickness, and the axis X is slightly eccentric with respect to the axis Y of the cam bolt 14.

The large-diameter cylindrical portion 21b constitutes a part of the Oldham coupling 19 and protrudes from the inside of the sprocket body 1a toward the electric motor 12 through the insertion hole 15a of the front plate 15. As shown in FIG. 5, the large-diameter cylindrical portion 21b has a two-sided width fitting hole 21c into which the two-sided width cylindrical base 20a of the intermediate member 20 can be fitted in the axial direction. Is formed. The large-diameter cylindrical portion 21b has two key grooves 21d at which the

transmission keys

20b and 20c of the intermediate member 20 can be fitted from the rotation axis direction at a position of about 180 ° in the circumferential direction of the tip portion on the electric motor 12 side. , 21e are formed.

The needle bearing 25 is fixed to a plurality of needle rollers 25a that roll on the outer peripheral surface of the head portion 14a of the cam bolt 14 and a step surface formed on the inner peripheral surface of the eccentric shaft portion 21a. And a shell 25b having a plurality of grooves for rollingly holding the 25a.

The ball bearing 22 is arranged so as to substantially entirely overlap the radial position of the needle bearing 25. The ball bearing 22 includes an inner race 22a, an outer race 22b, a ball 22c interposed between the two

races

22a and 22b, and a cage 22d for holding the ball 22c.

While the inner ring 22a is press-fitted and fixed to the outer peripheral surface of the eccentric shaft portion 21a, the outer ring 22b is free without being fixed in the axial direction. In other words, the outer ring 22b is configured such that one end surface on the electric motor 12 side in the axial direction does not contact the inner surface of the front plate 15 via the minute clearance. Further, the other end surface of the outer ring 22b in the axial direction is also prevented from contacting the rear surface of the disk-shaped main body 9a of the driven member 9 facing the outer ring 22b via a minute clearance.

外 In addition, the outer peripheral surface of each roller 23 is in rolling contact with the outer peripheral surface of the outer ring 22b. An annular clearance is formed between the outer peripheral surface of the outer ring 22b and the inner surface of the retainer 24. Therefore, the entire ball bearing 22 can be eccentrically moved in the radial direction with the eccentric rotation of the eccentric shaft portion 21a via the clearance.

The retainer 24 is formed in an annular plate shape, and is provided integrally with the outer peripheral portion of the disk-shaped main body 9a. That is, the retainer 24 is formed so as to linearly protrude from the base 11a of the journal portion 11 of the disc-shaped main body 9a toward the front plate 15. A predetermined clearance C is formed between the tip surface 24a of the retainer 24 and the inner surface 15c of the front plate 15.

保持 Further, the retainer 24 is formed with a plurality of substantially rectangular roller holding holes 24b respectively rotatably holding the plurality of rollers 23 at substantially equal intervals in the circumferential direction. The roller holding holes 24b are provided at equal intervals in the circumferential direction of the holder 24, are closed at the tip end side, and are formed in a rectangular shape elongated in the front-rear direction, and the total number thereof (the number of the rollers 23) is inside. The number of the internal teeth 5a of the tooth forming section 5 is smaller than the total number of teeth, so that a predetermined reduction ratio is obtained.

Each roller 23 is formed of an iron-based metal, and is fitted in the internal teeth 5 a of the internal tooth forming section 5 while moving in the radial direction with the eccentric movement of the ball bearing 22. Further, each roller 23 swings in the radial direction while being guided in the circumferential direction by both side edges of the roller holding hole 24b of the holder 24.

減速 Further, as shown in FIG. 3, the deceleration mechanism 13 is configured such that lubricating oil is supplied inside through a lubricating oil supply passage. The lubricating oil supply passage extends from the main oil gallery of the engine to the oil passage 26 formed inside the camshaft 2 from inside the cylinder head 01 and the disc-shaped main body 9 a of the driven member 9 in the axial direction of the camshaft 2. And an oil hole 27 formed therethrough.

The oil hole 27 has an upstream large-diameter end portion 27a communicating with the oil passage 26, and a downstream small-diameter other end portion 27b communicating with the vicinity of a side portion of the shell 25b of the needle bearing 25. ing.

Further, the lubricating oil flowing into the inside of the speed reduction mechanism 13 from the oil hole 27 passes through the inside of the ball bearing 22 and the inside of the retainer 24 on the outer peripheral side as shown by the arrow in the drawing, and from there, the bearing recess 10 and It flows in between the journal unit 11. In other words, the lubricating oil is provided for lubrication by passing between the both end surfaces 11 e and 11 f and the outer peripheral surface 11 d of the journal portion 11 and the inner side surface 10 b and the sliding bearing surface 10 a of the bearing recess 10. The air is further discharged from the insertion hole 15a of the front plate 15 to the outside.

The main oil gallery is supplied with lubricating oil from a discharge passage of an oil pump (not shown).
[Operation and effect of the present embodiment]
Hereinafter, the operation of the valve timing control device according to the present embodiment will be described.

First, when the timing sprocket 1 rotates via the timing chain with the rotation drive of the crankshaft of the engine, this rotational force is transmitted to the internal gear forming section 5. The rotational force of the internal teeth forming section 5 is transmitted from each roller 23 to the camshaft 2 via the retainer 24 and the driven member 9. Thus, the drive cam of the camshaft 2 opens and closes each intake valve.

時には During a predetermined engine operation after the engine is started, a control current from the control unit is supplied to the coil of the electric motor 12 to drive the motor output shaft 17 to rotate forward and reverse. The torque of the motor output shaft 17 is transmitted to the eccentric shaft 21, and the reduced torque is transmitted to the camshaft 2 by the operation of the speed reduction mechanism 13.

Accordingly, the camshaft 2 rotates forward and reverse relative to the timing sprocket 1 to change the relative rotation phase. Therefore, the opening and closing timing of each intake valve is controlled to be converted to the advance side or the retard side.

As described above, since the opening / closing timing of the intake valve is continuously converted to the advance side or the retard side, engine performance such as fuel efficiency and output of the engine can be improved.

In this embodiment, when the chain tension is applied to the gear portion 1b during the rotation driving, the sprocket 1 exerts a force (rotational force) in a tilt direction about the rotation center O, which is the center in the radial and axial directions of the journal portion 11, as a fulcrum. Moment). With this rotary motor, the bearing recess 10 abuts on the journal portion 11 in the axial direction, and axial loads F1 and F2 are generated. The axial loads F1 and F2 can be received by both

end surfaces

11e and 11f of the journal portion 11. Therefore, the tilting of the sprocket 1 can be suppressed.

That is, as described above, the length relationship between the bearing recess 10 (including the holding plate 8) and the journal 11 is set so as to satisfy the expression Ca <Cr. (D / B). As a result, as shown in FIG. 8, when the sprocket 1 is tilted counterclockwise in the figure with respect to the driven member 9, one end face 11e of the journal portion 11 is located on the lower side in the figure. An axial load F1 (open arrow) is received from the inner surface 10b. On the other hand, at the same time, on the upper side, the other end surface 11f of the journal portion 11 receives an axial load F2 (open arrow) from the inner side surface 8f of the holding plate 8.

By setting as described above, one of the one end 11da and the other end 11db in the axial direction of the outer peripheral surface 11d of the journal portion 11 is separated from the sliding bearing surface 10a of the bearing recess 10 by the inclination of the sprocket 1. Thus, the one end surface 11e and the other end surface 11f of the journal portion 11 abut against the inner side surface 10b and the inner side surface 8f of the bearing recess 10. That is, in a state where the sprocket 1 is inclined, the sliding bearing surface 10a does not contact both the one end 11da and the other end 11db of the outer peripheral surface 11d of the journal portion 11, and the axial side surfaces 10b, 8f of the bearing recess 10 are formed. Abuts on the journal section 11.

In other words, when the axial loads F1 and F2 are applied by the tilting of the sprocket 1 in the counterclockwise direction, the axial loads F1 and F2 are applied via the inner surface 10b of the bearing recess 10 and the inner surface 8f of the holding plate 8. Both ends 11e and 11f of the journal portion 11 can receive and regulate the journal.

This makes it possible to effectively suppress the inclination of the sprocket 1 with respect to the driven member 9.

The effect of suppressing the inclination of the sprocket 1 is, for example, as shown in FIG. 8, when the arrangement of the gear portion 1b of the sprocket 1 is moved toward the front plate 15, that is, with respect to the rotation center O of the inclination of the sprocket 1. It is also effective when the point where the chain tension is applied is offset.

In addition, since both axial loads F1 and F2 are received and regulated by both end faces 11e and 11f of the journal portion 11, a large rotational moment acts on the sprocket 1 and the journal portion 11 causes the bearing recess 10 to contact the sliding bearing surface 10a. The radial load F3 (open arrow), which is a radial load, can be sufficiently reduced.

Therefore, it is possible to sufficiently reduce the friction between the outer peripheral surface of the journal portion 11 and the slide bearing surface 10a. As a result, an always smooth bearing action for the driven member 9 of the sprocket 1 can be obtained. This improves the phase conversion speed of the valve timing control device.

Further, both the one end 11da and the other end 11db of the outer peripheral surface 11d of the journal 11 contact the sliding bearing surface 10a in a state where the sprocket 1 is inclined. When the end surface 11e and the other end surface 11f abut on the inner surface 10b and the inner surface 8f of the bearing recess 10, the friction ratio between the outer peripheral surface 11d of the journal 11 and the sliding bearing surface 10a is determined by the diameter D of the journal 11. And the axial width B. Therefore, if B <D as in the present embodiment, the effect is higher.

滑り The sliding bearing surface 10a of the bearing recess 10 is formed at a position axially overlapping the gear portion 1b of the sprocket 1. For this reason, the tension load of the chain wound around the gear portion 1b acts on the journal portion 11 via the sliding bearing surface 10a, so that the inclination of the sprocket 1 can be further suppressed.

Further, since the journal portion 11 is formed so as to protrude radially outward from the outer peripheral surface of the disk-shaped main body 9a, the axial width length B of the journal portion 11 which is the means for suppressing the inclination of the sprocket 1, ie, the holding plate The length A1 between the inner side surface 8f of the base 8 and the inner side surface 10b of the bearing recess 10 can be made sufficiently shorter than that of the conventional technique. As a result, the axial length of the entire device can be reduced, so that the device can be downsized.

In addition, since the length A1 between the inner side surface 8f and the inner side surface 10b can be reduced, the dimensional accuracy between the inner side surface 8f, the inner side surface 10b, and the journal portion 11 can be easily managed. As a result, the manufacturing operation becomes easy.

Further, a clearance C is formed between the distal end surface 24a of the retainer 24 and the inner side surface 15c of the front plate 15, and the journal portion 1 and the bearing recess 10 restrict the movement of the driven member 9 in the axial direction. Therefore, the occurrence of friction between the retainer 24 (the driven member 9) and the front plate 15 is suppressed. Therefore, the responsiveness of the relative rotation between the sprocket 1 and the driven member 9 is improved, and the generation of sound vibration can be suppressed.

Further, the lubricating oil supplied from the oil passage 26 to the inside of the speed reduction mechanism 13 through the oil hole 27 is moved between the sliding bearing surface 10a of the bearing recess 10 and the outer peripheral surface 11d of the journal 11 by centrifugal force during driving. Forced supply. Therefore, the lubricating properties of the inner surface of the bearing recess 10 and the entire outer surface of the journal portion 11 including between the two 10a and 11d are improved.

Particularly, since the sliding bearing surface 10a is located radially outside the tooth bottom surface of the internal teeth 5a of the internal tooth forming section 5, lubricating oil is likely to flow from the internal teeth 5a side due to centrifugal force. Accordingly, the lubricity between the two 10a and 11d is further improved.

In particular, the lubricating oil that has flowed into the bearing recess 10 is stored here even when the engine is stopped, so that the lubricating oil quickly moves between the entire inner surface of the bearing recess 10 and the entire outer surface of the journal 11 after driving. A lubricating action is obtained.

部位 Furthermore, a portion that becomes a hole edge of the central hole 8a of the inner peripheral portion 8b of the holding plate 8 is disposed inside the tooth bottom surface of each internal tooth 5a of the internal tooth forming portion 5. For this reason, when the engine is stopped, as shown in FIG. 3, the inner peripheral portion 8b functions as a dam, so that lubricating oil is sufficiently applied not only to the bearing recess 10 but also to the tooth bottom surface of each internal tooth 5a. It becomes possible to store. Therefore, the lubricity between each internal tooth 5a and each roller 23 during driving is improved, and smooth rotation of the speed reduction mechanism 13 is obtained.

The holding plate 8 has a thickness t1 larger than the thickness t of the front plate 15 and has a high rigidity. Therefore, the holding plate 8 has durability against an axial load received from the other end surface 11f of the journal portion 11. Improvement can be achieved. On the other hand, since the axial load from the one end surface 11e of the journal portion 11 is not directly received on the inner side surface 15c of the front plate 15, the thickness t can be made as small as possible. Therefore, the overall weight can be reduced.

製造 Further, since the second axial direction regulating portion uses the front plate 15 that covers the bearing recess 10, the manufacturing operation thereof is simple.

In the present embodiment, as the bearing of the sprocket 1 with respect to the driven member 9, not a ball bearing but a slide bearing using a bearing recess 10 and a journal 11 is used. For this reason, the structure is simplified, the manufacturing operation is facilitated, and the cost of parts can be reduced.

The present invention is not limited to the configuration of each of the above embodiments. For example, the reduction mechanism 13 may be, for example, a planetary gear type.

Also, if the journal portion 11 is formed in the radial direction while keeping the axial width unchanged, the radial length of both

end surfaces

11e and 11f increases, so that the inner peripheral portion 8b of the holding plate 8 The regulation effect in the axial (axial direction) by the side surface 8f and the inner side surface 10b of the bearing recess 10 increases. Thereby, the inclination of the sprocket 1 can be suppressed more effectively.

As the second axial direction restricting portion, the entire bearing concave portion 10 may be formed in a concave shape on the inner peripheral surface of the sprocket 1, and the inner peripheral portion 8b of the holding plate 8 may not be used as the inclination suppressing means.

The joint mechanism may be a joint other than the Oldham joint.

バルブ As the valve timing control device for an internal combustion engine based on the above-described embodiment, for example, the following embodiments can be considered.

That is, in a preferred embodiment of the present invention, a driving rotator to which torque from a crankshaft is transmitted, a driven rotator fixed to a camshaft and rotating integrally with the camshaft, and a motor output of an electric motor A phase change mechanism that changes the relative rotation phase of the driving rotator and the driven rotator by reducing the rotation of the shaft by a reduction mechanism, a sliding bearing surface provided on an inner periphery of the driving rotator, and the driven rotator A journal portion that is provided so as to protrude radially outward from the outer periphery of the journal, and has an outer peripheral surface that slides on the sliding bearing surface; and the journal that is provided on the drive rotating body and sandwiches the journal portion from both sides in the axial direction. A first axial direction restricting portion and a second axial direction restricting portion for restricting axial movement of the portion.

More preferably, the sliding bearing surface is offset in a rotation axis direction of the driving rotating body with respect to a meshing portion of the speed reduction mechanism, and is provided radially outside of the rotating shaft of the driving rotating body with respect to the meshing portion. Have been.

According to the present invention, since the lubricating oil in the speed reduction mechanism is supplied between the sliding bearing surface and the journal by centrifugal force, lubricity between the two is improved.

More preferably, the meshing portion meshes with an internal tooth provided on an inner periphery of the driving rotating body, and the rotation of the motor output shaft is reduced and transmitted to a transmitting portion of the driven rotating body. Having a transmission member,
The sliding bearing surface is provided radially outside of the tooth bottom of the internal teeth.

According to the present invention, since the sliding bearing surface is located radially outside the tooth bottom, lubrication is further improved.

More preferably, the transmission portion is provided in an annular shape protruding from the edge of the driven rotating body on the journal portion side toward the inner peripheral side of the internal teeth, and the driving rotating body is configured to drive the driving portion of the transmission portion. There is a cover that covers one side of the rotating body in the direction of the rotation axis, and a clearance is provided between the cover and the distal end surface of the transmission unit.

According to the present invention, since the clearance is provided between the cover and the distal end surface of the transmission portion, the occurrence of friction between the cover and the driven rotating body is suppressed. Therefore, the responsiveness of the relative rotation between the driven rotor and the drive rotor is improved.

More preferably, the driven rotating body has an oil hole for communicating an oil passage of the lubricating oil provided in the camshaft with a space radially inside the transmitting portion.

こと Since the sliding bearing surface is at the radially outer position, the lubricating oil flowing radially outward from the oil hole by centrifugal force improves lubricity.

More preferably, the driving rotating body is provided on an inner periphery of the driving rotating body, and has a concave portion having the sliding bearing surface on a bottom surface,
The first axial direction restricting portion is one end surface of the recess in the rotation axis direction of the driving rotating body.

More preferably, an annular plate member that covers the other end of the concave portion is fixed to the other side in the rotation axis direction of the drive rotating body, and the second axial direction restriction portion is formed by the plate member. .

More preferably, the second axial direction regulating portion has an inner diameter located radially inward of the root of the internal teeth.

潤滑 Since the lubricating oil in the speed reduction mechanism also accumulates at the bottom of the internal teeth, lubrication between each internal tooth and the rolling member is also improved.

More preferably, the thickness of the plate member in the rotation axis direction of the driving rotator is larger than the thickness of the cover in the rotation axis direction of the driving rotator.

耐久 By increasing the thickness and width of the plate member, it is possible to improve the durability against one axial load from the driven rotating body (journal portion) which is received by the second axial direction regulating portion. Conversely, the cover does not directly receive the other axial load from the driven rotating body, so that the thickness and width can be reduced, so that the weight can be reduced.

More preferably, the driving rotating body has external teeth on the outer periphery of which the rotational force from the crankshaft is transmitted, and the sliding bearing surface is arranged in the rotation axis direction of the driving rotating body with respect to the external teeth. It is in the overlapping position.

箇所 Because of the overlap, the portion of the endless cable wound around the external teeth where the load is applied overlaps with the sliding bearing surface, so that the inclination of the driven member can be further suppressed.

More preferably, the speed reduction mechanism, the motor output shaft is fitted, an eccentric shaft whose axis is eccentric with respect to the axis of the motor output shaft, an outer periphery of the eccentric shaft and an inner periphery of the internal teeth. And a retainer provided on the driven rotating body and having a plurality of roller holding holes for holding the plurality of rollers.

More preferably, the axial width between the first axial direction regulating portion and the second axial direction regulating portion is A1, the diameter of the sliding bearing surface is A2, and the axial width of the journal portion is B, When the diameter of the journal portion is D,
Ca = A1-B
Cr = A2-D
Ca <Cr ・ (D / B)
Is set to satisfy the expression.

More preferably, the driving rotating body has external teeth on the outer periphery of which the rotational force from the crankshaft is transmitted, and the sliding bearing surface is arranged in the rotation axis direction of the driving rotating body with respect to the external teeth. It is in the offset position.

As another preferred embodiment, a driving rotary member to which a rotational force from a crankshaft is transmitted, a driven rotary member fixed to a camshaft and rotating integrally with the camshaft, and a rotation of a motor output shaft of the electric motor A phase change mechanism that changes the relative rotational phase of the driving rotator and the driven rotator by reducing the speed of the driven rotator by a speed reduction mechanism; A journal portion that is provided to protrude radially outward from the outer periphery of the rotating body and slides on the slide bearing surface, and is provided on the drive rotating body, and is axially sandwiched between the journal portions from both sides in the axial direction. A first axial direction restricting portion and a second axial direction restricting portion for restricting movement,
Both the first axial direction restricting portion and the second axial direction restricting portion are provided on one side in the rotation axis direction with respect to the meshing portion of the speed reduction mechanism.

More preferably, the meshing portion includes a protruding portion that protrudes in an axial direction from the driven rotating body, and the reduced rotational force of the electric motor is transmitted to the protruding portion, and the driving rotating body includes the protruding portion. A plate member that covers one end of the driving rotator in the direction of the rotation axis, wherein the projecting portion contacts the plate member even if the driving rotator is inclined with respect to the driven rotator. A clearance is set between the one end and the plate member so as not to contact.

More preferably, when the driving rotary body is inclined with respect to the driven rotary body, the first axial direction restricting portion abuts on one end surface of the journal portion in the axial direction, and the second axial direction restricting portion. The radial gap between the sliding bearing surface and the journal portion is set such that the abutment is in contact with the other axial end surface of the journal portion.

DESCRIPTION OF SYMBOLS 1 ... Timing sprocket (drive rotary body), 1a ... Sprocket main body, 1b ... Gear part (external teeth), 2 ... Camshaft, 2a ... One end part, 3 ... Phase change mechanism, 8 ... Holding plate (plate member), 8b ... Inner peripheral part, 8f ... Inner surface (second axial direction restricting part), 9 ... Driving member (driven rotating body), 9a ... Disc-shaped body, 9b ... Fixed end part, 10 ... Bearing recess, 10a ... Sliding bearing surface Reference numeral 10b: Inside surface (one end surface / first axial direction regulating portion), 11: Journal portion, 11a: Base portion, 11d: Outer peripheral surface, 11e: One end surface, 11f: Other end surface, 12: Electric motor, 13: Reduction mechanism , 15: Front plate (cover), 19: Oldham coupling (coupling mechanism), 20: Intermediate member, 21: Eccentric shaft, 22: Ball bearing, 22a: Inner ring, 22b: Outer ring, 23: Roller, 24: Cage ( (Transmission part / projection part), 24b ... roller holder Holding hole, 25: Needle bearing, A1: Axial width between inner surface of bearing recess and inner surface of holding plate, A2: Diameter of sliding bearing surface, B: Axial width of journal portion, D: Journal Diameter, Ca: clearance (gap) between both end surfaces of the journal portion and the inner surface of the bearing recess and the inner surface of the holding plate, Cr: clearance (gap) between the sliding bearing surface and the outer peripheral surface of the journal portion ).

Claims

A driving rotating body to which the rotating force from the crankshaft is transmitted;
A driven rotating body fixed to the camshaft and rotating integrally with the camshaft;
A phase changing mechanism that changes the relative rotation phase of the driving rotator and the driven rotator by reducing the rotation of the motor output shaft of the electric motor by a reduction mechanism;
A sliding bearing surface provided on the inner periphery of the drive rotating body,
A journal portion which is provided so as to protrude radially outward from the outer periphery of the driven rotor, and whose outer peripheral surface slides on the slide bearing surface;
A first axial direction restricting portion and a second axial direction restricting portion which are provided on the drive rotating body and restrict axial movement of the journal portion while sandwiching the journal portion from both sides in the axial direction;
A valve timing control device for an internal combustion engine, comprising:
The valve timing control device for an internal combustion engine according to claim 1,
The sliding bearing surface is offset in a rotation axis direction of the driving rotating body with respect to a meshing portion of the speed reduction mechanism, and is provided radially outside of the rotating shaft of the driving rotating body with respect to the meshing portion. A valve timing control device for an internal combustion engine, comprising:
The valve timing control device for an internal combustion engine according to claim 2,
The meshing portion is an internal tooth provided on the inner periphery of the driving rotator, and a transmission member that meshes with the internal tooth, and transmits a rotation of the motor output shaft to a transmission portion of the driven rotator while the rotation of the motor output shaft is reduced. Has,
The valve timing control device for an internal combustion engine, wherein the sliding bearing surface is provided radially outside a root of the internal teeth.
The valve timing control device for an internal combustion engine according to claim 3,
The transmission portion is provided in an annular shape protruding from the edge of the driven rotating body on the journal portion side to the inner peripheral side of the internal teeth,
The drive rotator has a cover that covers one of the transmission units in the rotation axis direction of the drive rotator,
A valve timing control device for an internal combustion engine, comprising a clearance between the cover and a front end surface of the transmission unit.
The valve timing control device for an internal combustion engine according to claim 4,
The valve timing control device for an internal combustion engine, wherein the driven rotor has an oil hole that communicates an oil passage of lubricating oil in the camshaft with a space radially inside the transmission portion.
The valve timing control device for an internal combustion engine according to claim 3,
The drive rotating body is provided on an inner periphery of the drive rotating body, and has a concave portion having the sliding bearing surface on a bottom surface,
The valve timing control device for an internal combustion engine, wherein the first axial direction restricting portion is one end surface of the concave portion in a rotation axis direction of the driving rotating body.
The valve timing control device for an internal combustion engine according to claim 6,
An annular plate member that covers the other end of the concave portion is fixed to the other side in the rotation axis direction of the driving rotator,
The valve timing control device for an internal combustion engine, wherein the second axial direction restriction portion is formed by the plate member.
The valve timing control device for an internal combustion engine according to claim 7,
The valve timing control device for an internal combustion engine, wherein the inner diameter of the second axial direction regulating portion is located radially inward of a root of the internal teeth.
The valve timing control device for an internal combustion engine according to claim 7,
A valve timing control device for an internal combustion engine, wherein a thickness width of the plate member in a rotation axis direction of the driving rotor is larger than a thickness width of the cover in a rotation axis direction of the driving rotor.
The valve timing control device for an internal combustion engine according to claim 1,
The drive rotating body has external teeth on the outer periphery of which rotational force from the crankshaft is transmitted,
The valve timing control device for an internal combustion engine, wherein the sliding bearing surface is located at a position overlapping with the external teeth in a direction of a rotation axis of the driving rotating body.
The valve timing control device for an internal combustion engine according to claim 10,
The speed reduction mechanism,
An eccentric shaft in which the motor output shaft is fitted and whose shaft center is eccentric with respect to the shaft center of the motor output shaft;
A plurality of rollers disposed between the outer periphery of the eccentric shaft and the inner periphery of the internal teeth,
A holder provided on the driven rotating body and having a plurality of roller holding holes for holding the plurality of rollers,
A valve timing control device for an internal combustion engine, comprising:
The valve timing control device for an internal combustion engine according to claim 1,
The axial width between the first axial direction restricting portion and the second axial direction restricting portion is A1, the diameter of the sliding bearing surface is A2, the axial width of the journal portion is B, When the diameter is D,
Ca = A1-B
Cr = A2-D
Ca <Cr ・ (D / B)
A valve timing control device for an internal combustion engine, characterized by satisfying the following expression:
The valve timing control device for an internal combustion engine according to claim 12,
The drive rotating body has external teeth on the outer periphery of which rotational force from the crankshaft is transmitted,
The valve timing control device for an internal combustion engine, wherein the sliding bearing surface is located at a position offset with respect to the external teeth in a rotation axis direction of the driving rotating body.
A driving rotating body to which the rotating force from the crankshaft is transmitted;
A driven rotating body fixed to the camshaft and rotating integrally with the camshaft;
A phase changing mechanism that changes the relative rotation phase of the driving rotator and the driven rotator by reducing the rotation of the motor output shaft of the electric motor by a reduction mechanism;
A sliding bearing surface on the bottom surface of a concave portion provided on the inner periphery of the drive rotating body,
A journal portion that is provided to protrude radially outward from the outer periphery of the driven rotating body and slides on the slide bearing surface,
A first axial direction restricting portion and a second axial direction restricting portion which are provided on the drive rotating body and restrict axial movement while sandwiching the journal portion from both sides in the axial direction;
With
The valve timing control device for an internal combustion engine, wherein both the first axial direction restricting portion and the second axial direction restricting portion are provided on one side in the rotation axis direction with respect to a meshing portion of the speed reduction mechanism. .
The valve timing control device for an internal combustion engine according to claim 14,
The meshing portion includes a protruding portion that protrudes in the axial direction from the driven rotating body, and the reduced rotational force of the electric motor is transmitted to the protruding portion,
The driving rotator has a plate member that covers one end of the protrusion in the rotation axis direction of the driving rotator,
The protrusion has a clearance set between the one end and the plate member such that the protrusion does not contact the plate member even if the drive rotor is inclined with respect to the driven rotor. A valve timing control device for an internal combustion engine, comprising:
The valve timing control device for an internal combustion engine according to claim 14,
When the drive rotary body is inclined with respect to the driven rotary body, the first axial direction restricting portion contacts one end surface of the journal portion in the axial direction, and the second axial direction restricting portion is connected to the journal portion. A valve timing control device for an internal combustion engine, wherein a radial gap between the sliding bearing surface and the journal portion is set so as to contact the other end surface in the axial direction of the internal combustion engine.