The present invention relates to a valve timing controller including: a driving-side rolling body configured to rotate synchronously with a crankshaft of an internal combustion engine; a driven-side rolling body which is coaxially held in the driving-side rolling body through a sealing member and is configured to rotate in a unified manner with a camshaft for opening/closing a valve of the internal combustion engine, relative to the driving-side rolling body; an advance chamber configured to move a relative rotation phase of the driven-side rolling body relative to the driving-side rolling body in an advance direction by a volume increase of the advance chamber through an operating oil supply, and a retard chamber configured to move the relative rotation phase in a retard direction by a volume increase of the retard chamber through an operating oil supply, the advance chamber and the retard chamber being formed of the driving-side rolling body and the driven-side rolling body; and a torsion spring which is disposed in a space formed between a front plate or a rear plate of the driving-side rolling body and the driven-side rolling body and is configured to bias at all times the driving-side rolling body and the driven-side rolling body in the advance direction or the retard direction.
As the conventional valve timing controller, there can be mentioned a controller in which a torsion spring is provided between a driving-side rolling body and a driven-side rolling body. The torsion spring is provided for the purpose of, for example, canceling out a force in a retard direction acting on a camshaft so as to enhance responsiveness of phase variation of the camshaft, during the operation of an internal combustion engine.
Meanwhile, there are some cases in which a sealing member provided between the driving-side rolling body and the driven-side rolling body for the purpose of creating an advance chamber and a retard chamber. The sealing members are provided, for example, at positions in respective rolling bodies where two rolling bodies face each other. During the relative rotation of the two rolling bodies, even when the distance between the two rolling bodies is changed, each sealing member should firmly seal the gap between the rolling bodies with the use of a biasing spring or the like. However, in order to further enhance a sealing function of the sealing member, center alignment of the two rolling bodies should be performed at portions other than the sealing members.
In such a valve timing controller, in order to perform the center alignment of each member, the camshaft constitutes a component for the alignment. To put it another way, until all of the components are assembled, the center alignment of the driving-side rolling body and the driven-side rolling body is not performed.
The driving-side rolling body and the driven-side rolling body are assembled prior to the connection with the camshaft. Upon the assembly, in order to set the driving-side rolling body and the driven-side rolling body in an initial phase, a torsional torque has to be imparted to the torsion spring to some extent. Therefore, in the valve timing controller of such a type, various efforts have been made in order to firmly perform the connecting work of the camshaft, the center alignment work between the driving-side rolling body and the driven-side rolling body, or the like.
For example, in a case of a valve timing controller described in Patent Document 1, a bush is pressed into a vane rotor as driven-side rolling body. The bush has a function of retaining the vane rotor and a shoe housing as the driving-side rolling body on the same axis. The bush functions also as seat for receiving a bolt for connecting the camshaft to the vane rotor. The reason for this configuration of pressing the bush into the vane rotor is to accurately align the vane rotor with the bush.
Patent Document 1: Japanese Unexamined Patent Application Publication no. 2001-173414 (see paragraph [0015] and FIG. 1)
However, in the case of the device using such a bush, a number of the components is increased, and moreover, a number of manufacturing steps in which the bush is pressed into the vane rotor is increased. In addition, by pressing the bush into one side of the vane rotor, the vane rotor as a whole may be warped with a curvature protruding to a side opposite to the side into which the push is pressed. If the vane rotor has warpage, a gap is created between the vane rotor and the shoe housing when the valve timing controller is assembled. As a result, operating oil leaks from this gap and the responsiveness of advance-retard control becomes low. In order to correct the warpage of the vane rotor, it is possible that both faces of the vane rotor are ground to become flat. However, conducting such a process is not realistic, in view of production cost or the like.
The present invention was made with the view toward solving the above-mentioned problems of the prior art technique, and the object is provide a valve timing controller in which the driving-side rolling body and the driven-side rolling body are reasonably assembled.
The valve timing controller according to the present invention has a feature in that it includes: a driving-side rolling body configured to rotate synchronously with a crankshaft of an internal combustion engine; a driven-side rolling body which is coaxially held in the driving-side rolling body through a sealing member and is configured to rotate in a unified manner with a camshaft for opening/closing a valve of the internal combustion engine, relative to the driving-side rolling body; an advance chamber configured to move a relative rotation phase of the driven-side rolling body relative to the driving-side rolling body in an advance direction by a volume increase of the advance chamber through an operating oil supply, and a retard chamber configured to move the relative rotation phase in a retard direction by a volume increase of the retard chamber through an operating oil supply, the advance chamber and the retard chamber being formed of the driving-side rolling body and the driven-side rolling body; a torsion spring which is disposed in a space formed between a front plate or a rear plate of the driving-side rolling body and the driven-side rolling body and is configured to bias at all times the driving-side rolling body and the driven-side rolling body in the advance direction or the retard direction; and a first cylindrical portion provided in the front plate or the rear plate and a second cylindrical portion provided in the driven-side rolling body, the first and second cylindrical portions being insertable into each other in an axial direction.
<Effect>
With this configuration, the first cylindrical portion and the second cylindrical portion insertable into each other in the axial direction are separately provided on the driven-side rolling body and the front plate or rear plate, respectively. Therefore, the configurations of the driving-side rolling body and the driven-side rolling body can be simplified. To put it another way, without separately using a special member, the driving-side rolling body and the driven-side rolling body can be aligned. As a result, the valve timing controller can be obtained with which the number of components is reduced and the assembly work is simplified.
In the valve timing controller according to the present invention, a recess can be provided in one side face of the driven-side rolling body, into which recess an end portion of the camshaft is insertable, and an opening diameter of the recess can be made larger than an inner diameter of a hole formed in the rear plate into which the camshaft is insertable.
<Effect>
When the valve timing controller is assembled, first the driven-side rolling body is held in the driving-side rolling body and then the camshaft is connected to the driven-side rolling body. In the device of the present configuration, by alternately inserting the first cylindrical portion and the second cylindrical portion into each other, both members can be aligned within a predetermined region. However, since both members should rotate relative to each other, a gap should be present between the two members upon the operation of the device. Moreover, since the torsion spring is disposed across the driving-side rolling body and the driven-side rolling body, the driving-side rolling body and the driven-side rolling body tends to be eccentric due to a spring force. In the device of the present configuration, by making the opening diameter of the recess formed in the driven-side rolling body larger than the inner diameter of a hole formed in the rear plate, the hole is easily positioned within a range of the recess when the recess is seen in a shaft center direction from a side of the hole. In other words, when the driving-side rolling body and the driven-side rolling body are assembled but they become eccentric, an end face of the camshaft is unlikely to be brought into contact with a portion further outside the recess of the driven-side rolling body, and thus the insertion of the camshaft is less hindered. As a result, the end portion of the camshaft can be firmly inserted into the recess. As described above, in the device of the present configuration, the connection of the camshaft to the driven-side rolling body can be performed remarkably smoothly.
In the valve timing controller according to the present invention, the second cylindrical portion can be formed in an end face on an opposite side to a side of the camshaft from among end faces of the driven-side rolling body, and the first cylindrical portion can be set outside the second cylindrical portion.
<Effect>
The second cylindrical portion provided in the driven-side rolling body is formed on an opposite side to a side on which the camshaft is attached. Inward of the second cylindrical portion, a bolt is disposed which is for fixing the camshaft to the driven-side rolling body. With this configuration, the first cylindrical portion is positioned outside the second cylindrical portion, and thus an end face of the second cylindrical portion can be utilized as, for example, seat with which a head of the bolt comes into contact. With this configuration, the valve timing controller can be formed more reasonably.
In the valve timing controller according to the present invention, an annular groove can be formed in an end face on an opposite side to a side of the camshaft from among end faces of the driven-side rolling body, and an inner diameter-side wall of the annular groove can serve as the second cylindrical portion.
<Effect>
As in the present configuration, for obtaining the second cylindrical portion, the annular groove is formed in the end face of the driven-side rolling body. In this case, for example, a shape of a base material forming the driven-side rolling body can be a simple approximate column shape. If the column shape is enough as a basic shape of the driven-side rolling body, it can be obtained by firstly shaping an elongated member with extrusion molding of aluminum or the like, and then cutting the member into pieces each having a predetermined size. Therefore, the valve timing controller can be efficiently manufactured.
In the valve timing controller according to the present invention, an inner periphery of a hole formed in the rear plate and an outer diameter face of the camshaft can constitute a bearing.
<Effect>
It is desired that the driving-side rolling body and the driven-side rolling body rotate relative to each other as coaxially as possible. In this configuration, the camshaft and the rear plate form a bearing in such a manner that an outer periphery of the camshaft is taken as a base plane of the rotation. The driven-side rolling body is formed in a unified manner with the camshaft. Accordingly, as described above, by setting the basis of the rotation of both the driving-side rolling body and the driven-side rolling body to the camshaft, assembly accuracy of the valve timing controller can be enhanced.
(Entire Configuration)
Hereinbelow, a valve timing controller according to the present invention will be described with reference to the drawings.
As shown in
As shown in
In the housing 1, the inner rotor 2 is contained. In one face of the inner rotor 2, a connection recess 21 is formed, and to the connection recess 21, the camshaft 3 is assembled in a unified manner.
As shown in
The first projection 15 and the second projection 22 have a groove 16 and a groove 23 formed therein, respectively. Each of the grooves 16,23 includes: the sealing member 4; and a spring member 7 configured to bias the sealing member 4 in such a manner that the sealing members 4 protrude out of the grooves 16,23. The sealing member 4 includes: a plate-like body portion 41 extending along an axis X; and a pair of legs 42 protruding in the radial direction of the axis X from both end portions of the body portion 41 towards a bottom of the groove. The spring member 7 is disposed between the legs 42.
With these first projections 15 and second projections 22, a plurality of the advance chambers 51 and the retard chambers 52 are formed side-by-side in a rotational direction. As shown in
As shown in
For installing the valve timing controller into the internal combustion engine E, first, the torsion spring 6 is placed inside the housing 1. The torsion spring 6 is placed in an annular recess 17 formed in the front plate 11 of the housing 1. Next, the inner rotor 2 is attached to the housing 1, and then the sealing members 4 and the spring members 7 are attached. Upon this attachment, the inner rotor 2 is relatively displaced in either of the rotational directions. Further, the rear plate 13 is attached, and then the front plate 11 and the rear plate 13 are fastened with housing bolts 18 at a plurality of positions arranged circumferentially.
In the present invention, the front plate 11 and the inner rotor 2 have a projection and a recess which are insertable into each other along the axis X. As shown in
As described above, by integrally forming the first cylindrical portion 1a or the second cylindrical portion 2a with the front plate 11 or the inner rotor 2, a number of components can be reduced. In addition, as the number of components is reduced, a number of assembly steps is reduced. Especially, for example, by integrally forming the second cylindrical portion 2a with the inner rotor 2, centering accuracy of the second cylindrical portion 2a is remarkably improved as compared with the conventional device having a centering member. As a result, attachment of the camshaft 3, which will be described later, is further facilitated.
Focusing on a shape of the inner rotor 2, in the present embodiment, the inner rotor 2 is in a shape of an approximate column, as shown in
As shown in
In an end portion of the camshaft 3, a cylindrical space 32 having an inner diameter larger than the outer diameter of the cam bolt 31 is formed. A space between an inner face of the inner rotor 2 and an outer face of the cam bolt 31 together with a space between a wall face forming the cylindrical space 32 of the camshaft 3 and the outer face of the cam bolt 31 is utilized as, for example, the advance oil passage 81 for supplying and discharging the operating oil to and from the advance chamber 51. It should be noted that the retard oil passage 82 for supplying and discharging the operating oil to and from the retard chamber 52 is separately formed inside the camshaft 3, as shown in
The cam bolt 31 comes into contact with an end face of the second cylindrical portion 2a of the inner rotor 2. In this manner, the end face of the second cylindrical portion 2a functions as seat for fastening bolt. In addition, the contact of a head of the bolt against the second cylindrical portion 2a forms an oil seal in the advance oil passage 81. It should be noted that an oil seal 33 may be provided between the second cylindrical portion 2a and the cam bolt 31, as shown in
In the device of the present invention, in order to facilitate the attachment of the camshaft 3 to the inner rotor 2, shape and size of each part are set in the following manner.
As shown in
Specifically, an opening diameter of the chamfer 24, i.e. a maximum outer diameter of the connection recess 21 formed for the insertion of the camshaft 3 is made lager than an inner diameter of the shaft receiving hole 13a formed in the rear plate 13, so that the camshaft 3 can be inserted. Further, it is preferable that a difference D1 between the maximum outer diameter of the connection recess 21 and the inner diameter of the shaft receiving hole 13a is set larger than a gap size D2 in the radial direction between the first cylindrical portion 1a and the second cylindrical portion 2a.
With the present configuration, by simply inserting the camshaft 3 into the shaft receiving hole 13a, the distal end of the camshaft 3 is brought into contact with the chamfer 24, and an effect of aligning the inner rotor 2 can be obtained.
It should be noted that, when an inner diameter of the connection recess 21 formed in the inner rotor 2 and the inner diameter of the shaft receiving hole 13a formed in the rear plate 13 are compared, the inner diameter of the shaft receiving hole 13a is slightly larger. The reason for this is that the camshaft 3 should be received by the connection recess 21 of the inner rotor 2 without forming a gap, and at the same time, the camshaft 3 should be supported by the shaft receiving hole 13a of the rear plate 13 with a predetermined gap.
In addition, with the present configuration, the end portion of the camshaft 3 can be made in a simple cylindrical shape and the structure of the end portion of the camshaft 3 can be simplified. Accordingly, the valve timing controller can be reasonably obtained.
In the present configuration, a bearing is formed between the camshaft 3 and the rear plate 13. In this manner, by aligning the centers of the housing 1 and the inner rotor 2 with the camshaft 3, and by setting the basis of the rotation of both the inner rotor 2 and the housing 1 to the camshaft 3, assembly accuracy of the valve timing controller can be enhanced.
Herein, the front plate 11 and the peripheral wall 12 are formed as separate members. In this manner, when the housing 1 is formed of a plurality of components, not only time and effort for manufacturing each component increase, but also quality maintenance of a product as a whole becomes difficult due to accumulation of error in work accuracy of each component.
However, depending on the shape of the component, there are some cases in which the accuracy of the component is improved and the accuracy and function of the product as a whole are improved, if the components are separately manufactured. In the case of the present device, in order to prevent leakage of the operating oil from between the advance chamber 51 and the retard chamber 52, it is necessary that an inward face 19a of the front plate 11 be brought into slidable contact with a frontward face 29 of the inner rotor 2, and an inner periphery 19b of the peripheral wall 12 be brought into slidable contact with the sealing member 4 provided in the second projection 22. For this purpose, the inward face 19a of the front plate 11 should be made as flat as possible, and the inner periphery 19b of the peripheral wall 12 should be made as cylindrical as possible. In such a case, finishing accuracy or the like of each face is improved, if each member is separately manufactured as an article having a simple shape. As a result, when product quality, production cost and the like together are taken into consideration, producibility as a whole can be enhanced.
As shown in
The first cylindrical portion 1a may be formed in the rear plate 13 of the housing 1, instead of the front plate 11.
In addition, it suffices if the first cylindrical portion 1a and the second cylindrical portion 2a overlap with each other in the radial direction. Therefore, it does not matter whether or not the first cylindrical portion 1a protrudes relative to the front plate 11, and it does not matter either, whether or not the second cylindrical portion 2a is protrudes relative to the inner rotor 2.
Moreover, the inner rotor 2 or the housing 1 may be produced by extrusion molding or injection molding using aluminum or the like, and alternatively, produced by sintering various metals.
The valve timing controller according to the present invention can be used as valve opening-closing controller on an intake side or an exhaust side of the internal combustion engine.
1
a First cylindrical portion
2
a Second cylindrical portion
3 Camshaft
4 Sealing member
6 Torsion spring
11 Front plate
13 Rear plate
51 Advance chamber
52 Retard chamber
90 Crankshaft
E Internal combustion engine
Filing Document | Filing Date | Country | Kind | 371c Date |
---|---|---|---|---|
PCT/JP2011/072706 | 9/26/2011 | WO | 00 | 2/6/2014 |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO2013/046474 | 4/4/2013 | WO | A |
Number | Name | Date | Kind |
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6039016 | Noguchi | Mar 2000 | A |
20010003974 | Mizutani et al. | Jun 2001 | A1 |
20020100445 | Takenaka et al. | Aug 2002 | A1 |
20020139332 | Takenaka | Oct 2002 | A1 |
20040244746 | Kinugawa | Dec 2004 | A1 |
20050284432 | Tsukada | Dec 2005 | A1 |
20060137635 | Hayashi | Jun 2006 | A1 |
20070240656 | Ikihara | Oct 2007 | A1 |
20070266970 | Ogawa | Nov 2007 | A1 |
20110061620 | Noguchi et al. | Mar 2011 | A1 |
20110073056 | Kobayashi et al. | Mar 2011 | A1 |
Number | Date | Country |
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198 49 959 | May 1999 | DE |
1 795 715 | Jun 2007 | EP |
2 305 969 | Apr 2011 | EP |
2001-173414 | Jun 2001 | JP |
2001-317314 | Nov 2001 | JP |
2002-357106 | Dec 2002 | JP |
2007-285200 | Nov 2007 | JP |
Entry |
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Notification Concerning Transmittal of International Preliminary Report on Patentability (Chapter I of the Patent Cooperation)(Form PCT/IB/326 & Form PCT/IB/373) and the Written Opinion of the International Searching Authority (Form PCT/ISA/237) issued on Apr. 10, 2014, in the corresponding International Application No. PCT/JP2011/072706. (8 pages). |
International Search Report (PCT/ISA/210) mailed on Jun. 29, 2012, by the European Patent Office as the International Searching Authority for International Application No. PCT/JP2011/072706. |
Written Opinion (PCT/ISA/237) mailed on Jun. 29, 2012, by the European Patent Office as the International Searching Authority for International Application No. PCT/JP2011/072706. |
Office Action (Notice of Reasons for Rejection) issued on Feb. 26, 2015, by the Japanese Patent Office in corresponding Japanese Patent Application No. 2014-509531 and an English translation of the Office Action. (5 pages). |
Number | Date | Country | |
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20140196676 A1 | Jul 2014 | US |