This invention relates to a valve opening and closing timing control apparatus including a torsion coil spring which biases a driven-side rotational member integrally rotating with a camshaft of an internal combustion engine in an advanced angle direction or a retarded angle direction relative to a drive-side rotational member rotating synchronously with a crankshaft of the internal combustion engine.
In the aforementioned valve opening and closing timing control apparatus, an accommodation portion for accommodating the torsion coil spring is provided at a radially inner side of the driven-side rotational member. In a case where a relative rotational phase between the drive-side rotational member and the driven-side rotational member changes, a degree of torsion of the torsion coil spring changes within the accommodation portion, which changes outer diameter dimensions of the torsion coil spring. With the aforementioned configuration change, a portion of the torsion coil spring may slidably move relative to a bottom surface or an inner wall surface of the accommodation portion. In this case, an abrasion of a portion of the driven-side rotational member relative to which the coil spring slidably moves becomes a problem.
In order to address the aforementioned abrasion, according to a valve opening and closing timing control apparatus disclosed in Patent document 1, for example, a flower-shaped oil reservoir portion is provided at a contact surface of a driven-side rotational member making contact with a torsion coil spring so as to enhance a lubrication performance of the torsion coil spring. At this time, because oil includes foreign substances such as abrasion powders, for example, plural drain hole portions are provided at the oil reservoir portion so as to penetrate through the driven-side rotational member in an axial direction thereof. The oil is easily discharged via the drain hole portions when the valve opening and closing timing control apparatus is stopped to thereby remove the foreign substances.
In a valve opening and closing timing control apparatus disclosed in Patent document 2, a washer is arranged between a driven-side rotational member and a torsion coil spring in a rotation axis direction of the driven-side rotational member. The washer includes a guide portion obtained by cutting and lifting-up an outer edge portion to support the torsion coil spring from an inner side and a washer portion arranged between a surface of the torsion coil spring extending in a radial direction thereof and the bottom surface of the accommodation portion of the driven-side rotational member. Deformation of the torsion coil spring in the radial direction is restrained by the guide portion to thereby inhibit a contact between an outer peripheral portion of the torsion coil spring and an inner peripheral surface of the accommodation portion. In addition, the washer portion inhibits a contact between the torsion coil spring and the bottom surface of the accommodation portion of the driven-side rotational member. Because the torsion coil spring and the driven-side rotational member are configured so as not to directly make contact with each other, an abrasion of the driven-side rotational member in association with changes in outer diameter dimensions of the torsion coil spring is restrained.
Patent document 1: JP2005-240651A
Patent document 2: JP2012-92739A
The valve opening and closing timing control apparatus disclosed in Patent document 1 is configured in a manner that the plural hole portions of the oil reservoir portion are in communication with a drain so that the oil is discharged to the drain when the valve opening and closing timing control apparatus is stopped. Thus, storability of oil decreases. In addition, because the plural hole portions provided at the oil reservoir portion are relatively large hole portions penetrating through the driven-side rotational member in the axial direction, strength of the driven-side rotational member decreases.
According to the valve opening and closing timing control apparatus disclosed in Patent document 2, an oil reservoir portion is provided using a void where the guide portion originally exists between a portion of the torsion coil spring supported by the guide portion which is provided at the washer in an extending manner and the bottom surface of the accommodation portion of the driven-side rotational member. At this time, though the inner side of the torsion coil spring is supported by the guide portion, a clearance may be generated between the torsion coil spring and the guide portion in a case where the outer diameter dimensions of the torsion coil spring change due to the change in degree of torsion. Thus, the oil at the aforementioned oil reservoir portion flows out through the clearance so that a performance of oil supply to the torsion coil spring may not be maintained.
The present invention is made in view of the drawback mentioned above and an object of the invention is to provide a valve opening and closing timing control apparatus including an oil reservoir portion which may effectively supply oil between a torsion coil spring and a driven-side rotational member.
A first characteristic construction of a valve opening and closing timing control apparatus according to the present invention includes a drive-side rotational member rotating synchronously with a crankshaft of an internal combustion engine, a driven-side rotational member integrally rotating with a camshaft of the internal combustion engine and rotating on a rotation axis same as a rotation axis of the drive-side rotational member, a phase control mechanism controlling to change a relative rotational phase between the drive-side rotational member and the driven-side rotational member, a torsion coil spring provided at an accommodation chamber which is defined by a front member provided at the drive-side rotational member and a tubular void provided at the driven-side rotational member in a state where the tubular void faces the front member, the torsion coil spring engaging with the front member and the driven-side rotational member to bias the driven-side rotational member in an advanced angle direction or a retarded angle direction relative to the driven-side rotational member, and an oil reservoir portion defined by an outer surface of the torsion coil spring facing the driven-side rotational member and at least one recess portion provided at the driven-side rotational member, the recess portion being provided in a radially outer direction from a position at a radially outer side than an inner diameter of the torsion coil spring and at a radially inner side than an outer diameter of the torsion coil spring.
According to the present construction, the oil reservoir portion is provided using a surface of a portion of the torsion coil spring to securely supply the oil to the torsion coil spring. In addition, the recess portion forming the oil reservoir portion is provided in the radially outer direction from the position at the radially outer side than the inner diameter of the torsion coil spring and at the radially inner side than the outer diameter of the torsion coil spring, so that the oil at the oil reservoir portion may be securely supplied to an outer circumferential side of the torsion coil spring. A sliding performance of the torsion coil spring increases to inhibit an abrasion of the driven-side rotational member and to increase durability thereof. Further, in a case where the internal combustion engine is stopped for a long time period, a state where the oil is adhered to the torsion coil spring is maintained. Thus, the sliding performance of the torsion coil spring for the next start is inhibited from being deteriorated to thereby smoothly perform a phase control between the drive-side rotational member and the driven-side rotational member.
Another characteristic construction of the valve opening and closing timing control apparatus according to the present invention is that the at least one recess portion includes a plurality of recess portions which are arranged along a circumferential direction of the driven-side rotational member.
According to the present construction, in a case where the plural recess portions are arranged along the circumferential direction, the oil may be stored in a dispersed manner at the oil reservoir portion. Specifically, because the oil is restricted to flow downward and is stored at an inner wall portion at the recess portion positioned at an upper side when the valve opening and closing timing control apparatus is stopped, an effect of oil supply to an entire circumference of the torsion coil spring may increase.
Still another characteristic construction of the valve opening and closing timing control apparatus according to the present invention is that a plate member is provided between the torsion coil spring and the driven-side rotational member, and the recess portion is defined by an outer edge portion of the plate member.
According to the present construction, the recess portion is defined by the outer edge portion of the plate member provided between the torsion coil spring and the driven-side rotational member. Thus, the oil reservoir portion including a depth corresponding to a thickness of the plate member may be easily provided.
Still another characteristic construction of the valve opening and closing timing control apparatus according to the present invention is that the driven-side rotational member is made of a ferrous material, and the oil reservoir portion is provided at a bottom surface of the accommodation chamber of the driven-side rotational member.
The driven-side rotational member is made of the ferrous material so that a degree of abrasion of the driven-side rotational member is small even when the driven-side rotational member directly makes contact with the torsion coil spring. Thus, in a case where the driven-side rotational member is formed of the ferrous material, the recess portion may be directly provided at the bottom surface of the accommodation chamber of the driven-side rotational member. Accordingly, the number of components is reduced and assembly hours decrease to thereby obtain the valve opening and closing timing control apparatus with a simple construction.
Still another characteristic construction of the valve opening and closing timing control apparatus according to the present invention is that an engagement portion engaging with one end portion of the torsion coil spring protrudes to a radially outer side from a peripheral wall surface of the accommodation chamber of the driven-side rotational member, the engagement portion being connected to the recess portion.
According to the present construction, the engagement portion engaging with one end portion of the torsion coil spring is provided so that the oil is also supplied to the end portion of the torsion coil spring to maintain lubrication with the driven-side rotational member. Accordingly, the abrasion of the driven-side rotational member may be reduced to inhibit a generation of frictional sound between the end portion of the torsion coil spring and the driven-side rotational member. Even in a case where a foreign substance is generated by the abrasion between the torsion coil spring and the driven-side rotational member, such foreign substance moves to the engagement portion by a centrifugal force, for example. As a result, a sliding movement between the torsion coil spring and the driven-side rotational member may be smoothly maintained.
Embodiments of the present invention are explained below with reference to drawings.
[Entire Construction]
As illustrated in
[Outer Rotor and Inner Rotor]
As illustrated in
The torsion coil spring 10 is disposed at an accommodation chamber 23 defined by the front plate 4 and a tubular void which is provided at the inner rotor 3 in a state facing the front plate 4. The torsion coil spring 10 engages with the front plate 4 and the inner rotor 3 in a state being torsionally deformed in a diameter reduction direction. The torsion coil spring 10 biases the inner rotor 3 in the advanced angle direction or a retarded angle direction relative to the outer rotor 1.
In a case where the crankshaft C is driven to rotate, a rotation driving force is transmitted to the rear plate 5 via a power transmission member such as a chain, for example, so that the outer rotor 1 rotates in a direction illustrated by an arrow S in
Plural first partition portions 8 protruding inward in a radial direction are provided at an inner circumferential portion of the outer rotor 1. Plural second partition portions 9 protruding outward in the radial direction are provided at an outer circumferential portion of the inner rotor 3. A void between the outer rotor 1 and the inner rotor 3 is divided by the first partition portions 8 into plural hydraulic chambers. Each of the plural hydraulic chambers is divided by each of the second partition portions 9 into the advanced angle chamber 11 and the retarded angle chamber 12. Seal members SE are provided at a position of the first partition portion 8 facing an outer peripheral surface of the inner rotor 3 and at a position of the second partition portion 9 facing an inner peripheral surface of the outer rotor 1.
As illustrated in
The phase control mechanism A includes an oil pan, an oil pump, a fluid control valve OCV, a fluid switching valve OSV and an electronic control unit ECU controlling operations of the fluid control valve OCV and the fluid switching valve OSV. Because of a control operation by the phase control mechanism A, the inner rotor 3 is displaced in the advanced angle direction (in the direction illustrated by the arrow S1 in
The inner rotor 3 and the camshaft 2 are fastened and fixed by a bolt 21. The bolt 21 is fastened to an internally threaded portion 2b provided at a back side of an insertion bore 2c provided at a tip end portion of the camshaft 2. Accordingly, the inner rotor 3 is integrally fixed to the tip end portion of the camshaft 2. A penetration bore 25 through which the bolt 21 penetrates is provided at the inner rotor 3. A head portion of the bolt 21 is held within the accommodation chamber 23. A clearance defined by the penetration bore 25 of the inner rotor 3, the insertion bore 2c of the camshaft 2 and the bolt 21 functions as the advanced angle passage 13.
[Oil Reservoir Portion]
A plate member 40 is arranged between the torsion coil spring 10 and a bottom surface 23a of the accommodation chamber 23 of the inner rotor 3. The plate member 40 is made of steel, for example, so that the plate member 40 is unlikely to be worn away by a sliding contact with the torsion coil spring 10. The plate member 40 includes a circular configuration along an outer circumference of the accommodation chamber 23. As illustrated in
Accordingly, the oil reservoir portion 50 is provided using a surface of a portion of the torsion coil spring 10 to securely supply the oil to the torsion coil spring 10. A sliding performance of the torsion coil spring 10 increases to inhibit an abrasion of the inner rotor 3 and to increase durability thereof. In addition, in a case where the engine E is stopped for a long time period, a state where the oil is adhered to the torsion coil spring 10 is maintained. Thus, the sliding performance of the torsion coil spring 10 for the next start is inhibited from being deteriorated to thereby smoothly perform a phase control between the outer rotor 1 and the inner rotor 3.
As illustrated in
The plural recess portions 44 are arranged along a circumferential direction of the inner rotor 3 to thereby store the oil in a dispersed manner at the oil reservoir portion 50. Specifically, because the oil is stored at the recess portion 44 positioned at an upper side when the valve opening and closing timing control apparatus is stopped, an effect of oil supply to the torsion coil spring 10 may increase.
[Assembly Structure of Torsion Coil Spring]
As illustrated in
As illustrated in
Holding portions 20 supporting an outer circumferential side of the winding portion 19 over an entire circumference thereof are provided at a rear surface (inner surface side) of the front plate 4. The holding portions 20 are arranged along the two inner arc portions 18a and the two outer arc portions 18b respectively. The holding portions 20 include first holding portions 20a arranged along the inner arc portions 18a and second holding portions 20b arranged along the outer arc portions 18b. A surface of the holding portion 20 in contact with the spring body 10a is formed in a spiral manner including an inclination along a pitch of the spring body 10a which is torsionally deformed.
The first holding portions 20a support an inner circumferential side of the winding portion 19 and the second holding portions 20b support an outer circumferential side of the winding portion 19. The winding portion 19 positioned at the outer arc portions 18b is exposed to a front surface side of the front plate 4 via the different diameter penetration bores 18. Accordingly, the inner circumferential side and the outer circumferential side of the torsion coil spring 10 are supported by the first holding portions 20a and the second holding portions 20b so that an axial position of the torsion coil spring 10 substantially matches the rotation axis X of the inner rotor 3.
One of the two outer arc portions 18b is provided with the front-side engagement portion 16 engaging with the front-side spring end portion 10b. The front-side engagement portion 16 engages with the front-side spring end portion 10b from a circumferential direction of the coil spring in a state where the torsion of the torsion coil spring 10 is obtained.
In the front-side engagement portion 16, a recess surface portion 24 in communication with one of the outer arc portions 18b is provided at the front surface side of the front plate 4 so that an engagement surface portion 26 with which the front-side spring end portion 10b makes contact from the circumferential direction of the coil spring for engagement is provided at the recess surface portion 24. Accordingly, the front-side spring end portion 10b is engageable with a bottom surface portion 24a of the recess surface portion 24 from the rear surface side of the front plate 4.
The rotor-side engagement portion 17 is constituted by a groove portion 9a provided at one of the plural second partition portions 9 provided at the inner rotor 3. The groove portion 9a is provided to protrude outward in the radial direction from a peripheral wall surface of the accommodation chamber 23 and to be connected to the recess portion 44.
Because the rotor-side engagement portion 17 is provided, the oil is also supplied to the rotor-side spring end portion 10c of the torsion coil spring 10 to thereby maintain lubrication with the inner rotor 3. Accordingly, the abrasion of the inner rotor 3 may be reduced to inhibit a generation of frictional sound between the rotor-side spring end portion 10c of the torsion coil spring 10 and the inner rotor 3, for example. Even in a case where a foreign substance is generated by the abrasion between the torsion coil spring 10 and the inner rotor 3, for example, such foreign substance moves to the rotor-side engagement portion 17 by a centrifugal force, for example. As a result, a sliding movement between the torsion coil spring 10 and the inner rotor 3 may be smoothly maintained.
A torsional force of the torsion coil spring 10 where the rotor-side spring end portion 10c engages with the rotor-side engagement portion 17 is received by the front plate 4 with which the front-side spring end portion 10b engages. Accordingly, the torsion coil spring 10 biases the inner rotor 3 in the advanced angle direction relative to the outer rotor 1.
(1) The inner rotor 3 may be made of a ferrous material. In this case, a degree of abrasion of the inner rotor 3 caused by the contact with the torsion coil spring 10 decreases. In a case where the inner rotor 3 is made of the ferrous material, the recess portion 44 may be directly provided at the bottom surface 23a of the accommodation chamber 23 of the inner rotor 3 as illustrated in
The recess portion 44 may be provided over the entire circumference of the bottom surface 23a of the accommodation chamber 23. Alternatively, as illustrated in
(2) The recess portion 44 may be a bore portion provided at the plate member 40 or the bottom surface 23a of the accommodation chamber 23 to be disposed at a position at an inner side of the outer diameter of the torsion coil spring 10 and at an outer side than the inner diameter of the torsion coil spring 10.
(3) In the aforementioned embodiment, an example where the rotor-side engagement portion 17 is provided outward in the radial direction. Alternatively, the rotor-side engagement portion 17 may be provided along a rotation axis direction. The front-side engagement portion 16 may be also provided at the rear surface (inner surface side) of the front plate 4. As a result, the oil pushed out from the advanced angle chamber 11 or the retarded angle chamber 12 is supplied to the front-side spring end portion 10b of the torsion coil spring 10 to decrease a sliding resistance or a sliding sound at the rear surface (inner surface side) of the front plate 4.
The present invention is applicable to a valve opening and closing timing control apparatus for an internal combustion engine of an automobile and other applications.
Filing Document | Filing Date | Country | Kind |
---|---|---|---|
PCT/JP2014/053482 | 2/14/2014 | WO | 00 |
Publishing Document | Publishing Date | Country | Kind |
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WO2015/121975 | 8/20/2015 | WO | A |
Number | Name | Date | Kind |
---|---|---|---|
6981477 | Uozaki | Jan 2006 | B2 |
20050183682 | Uozaki et al. | Aug 2005 | A1 |
20130167787 | Noguchi et al. | Jul 2013 | A1 |
Number | Date | Country |
---|---|---|
2005-240651 | Sep 2005 | JP |
2012-092739 | May 2012 | JP |
Entry |
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International Search Report (PCT/ISA/210) dated Mar. 18, 2014, by the Japanese Patent Office as the International Searching Authority for International Application No. PCT/JP2014/053482. |
Written Opinion (PCT/ISA/237) dated Mar. 18, 2014, by the Japanese Patent Office as the International Searching Authority for International Application No. PCT/JP2014/053482. |
Number | Date | Country | |
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20170167314 A1 | Jun 2017 | US |