US20120167846A1 - Valve timing regulator - Google Patents
Valve timing regulator Download PDFInfo
- Publication number
- US20120167846A1 US20120167846A1 US13/376,101 US200913376101A US2012167846A1 US 20120167846 A1 US20120167846 A1 US 20120167846A1 US 200913376101 A US200913376101 A US 200913376101A US 2012167846 A1 US2012167846 A1 US 2012167846A1
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- United States
- Prior art keywords
- holding member
- rotor
- axial direction
- assist spring
- vane
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
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Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
- F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
- F01L1/34—Valve-gear or valve arrangements, e.g. lift-valve gear characterised by the provision of means for changing the timing of the valves without changing the duration of opening and without affecting the magnitude of the valve lift
- F01L1/344—Valve-gear or valve arrangements, e.g. lift-valve gear characterised by the provision of means for changing the timing of the valves without changing the duration of opening and without affecting the magnitude of the valve lift changing the angular relationship between crankshaft and camshaft, e.g. using helicoidal gear
- F01L1/3442—Valve-gear or valve arrangements, e.g. lift-valve gear characterised by the provision of means for changing the timing of the valves without changing the duration of opening and without affecting the magnitude of the valve lift changing the angular relationship between crankshaft and camshaft, e.g. using helicoidal gear using hydraulic chambers with variable volume to transmit the rotating force
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
- F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
- F01L1/34—Valve-gear or valve arrangements, e.g. lift-valve gear characterised by the provision of means for changing the timing of the valves without changing the duration of opening and without affecting the magnitude of the valve lift
- F01L1/344—Valve-gear or valve arrangements, e.g. lift-valve gear characterised by the provision of means for changing the timing of the valves without changing the duration of opening and without affecting the magnitude of the valve lift changing the angular relationship between crankshaft and camshaft, e.g. using helicoidal gear
- F01L1/3442—Valve-gear or valve arrangements, e.g. lift-valve gear characterised by the provision of means for changing the timing of the valves without changing the duration of opening and without affecting the magnitude of the valve lift changing the angular relationship between crankshaft and camshaft, e.g. using helicoidal gear using hydraulic chambers with variable volume to transmit the rotating force
- F01L2001/3445—Details relating to the hydraulic means for changing the angular relationship
- F01L2001/34483—Phaser return springs
Definitions
- the present invention relates to a valve timing adjusting apparatus that changes automatically opening and closing timings of an exhaust valve in response to an operating condition of an internal combustion engine.
- This type of valve timing adjusting apparatus includes: a camshaft for driving an exhaust valve of an internal combustion engine to open and close; a case that is rotatably provided on the camshaft and rotationally driven by an output of the internal combustion engine; a rotor that is relatively rotatably housed inside the case and coupled to the camshaft; and a locking means that constrains a relative rotation between the case and the rotor when operated by a mechanical urging force, and releases the constraint when operated by a fluid control pressure applied from an internal hydraulic chamber in a direction opposing the mechanical urging force.
- Patent Document 1 discloses a constitution for holding the assist spring in which a resin holding member is inserted into recesses provided in the rotor and the case.
- Patent Document 1 Japanese Patent Publication No. 3,964,207
- Patent Document 1 discloses that one pair of holding members are set to hold the two ends of the assist spring, but provides no detailed descriptions of an axial direction length of the holding members or an inlet shape of an assist spring insertion hole. Therefore, in a practical use, the holding member may tilt within the range of a gap between the holding member and the recess or is fallen in a stretched state between a cover and a housing at the two ends thereof due to the thermal expansion or the like; thus, there is a problem such that inconveniences such as a reduction in a rotor operating speed due to the friction and an increase in leakage due to the wear on the sliding surface between the cover and the housing are concerned.
- the present invention has been made to solve the aforementioned problem that is caused by a holding member for holding an assist spring disposed in an hydraulic chamber, and an object thereof is to provide a valve timing adjusting apparatus in which decrease in the operating speed, reduction in the durability and so on are solved.
- a valve timing adjusting apparatus includes: a plurality of shoes formed on an inner peripheral surface of a case; a plurality of vanes provided on an outer peripheral surface of a rotor relatively rotatably housed in the case, each forming a retard hydraulic chamber and an advance hydraulic chamber between the vane and the two side-wall surfaces in a circumferential direction of the corresponding shoe; recesses provided opposite to the wall surfaces in the circumferential direction of the shoe and the vane in the advance hydraulic chamber; a holding member insertion-disposed into the recess from an axial direction; and an assist spring disposed between the holding member on the shoe side and the holding member on the vane side to urge the rotor in an advance direction, wherein a clearance formed by a length in the axial direction of the holding member provided on the vane side and a length in the axial direction of the case is set to be equal to or greater than a sum of an increment of the length in the axial direction in consideration of a tilt of the holding member produced by a gap between the
- the clearance formed by the length in the axial direction of the holding member provided on the vane side and the length in the axial direction of the case is set to be equal to or greater than the sum of the increment of the length in the axial direction in consideration of the tilt of the holding member produced by the gap between the holding member and the recess, and the increment due to the thermal expansion; thus, even when the holding member tilts within the range of the gap provided between the member and the recess in the vane or shoe, or even when there occurs the tilt due to the thermal expansion upon an increase of oil temperature (the rotor and case are formed out of iron-based materials and have a smaller linear expansion coefficient than the holding member made of resin), the tilt of the holding member during the assembly of the member and the assist spring, or the tilt due to rotor operations or vibrations; the following inconveniences can be prevented reliably: the occurrence of a stretched state between a cover and a housing at the two ends, the reduction in the rot
- FIG. 1 is a radial direction sectional view of a valve timing adjusting apparatus of a first embodiment of the present invention, taken along a line 2 - 2 in FIG. 2 .
- FIG. 2 is an axial direction sectional view of the valve timing adjusting apparatus of the first embodiment of the present invention, taken along a line 1 - 1 in FIG. 1 .
- FIG. 3 is a front view showing a condition in which an assist spring is attached to an assist spring insertion hole provided in a holding member inserted into a recess of a vane.
- FIG. 4 is a longitudinal sectional side view taken along a line 3 - 3 in FIG. 3 .
- FIG. 1 is a radial direction sectional view of a valve timing adjusting apparatus of a first embodiment in the present invention, taken along a line 2 - 2 in FIG. 2
- FIG. 2 is an axial direction sectional view of the valve timing adjusting apparatus of the first embodiment in the invention, taken along a line 1 - 1 in FIG. 1 .
- a sprocket portion 2 for transmitting a driving force from a crank is formed on the outer periphery of a case 1 , and shoes 3 a to 3 d forming hydraulic chambers are provided in the inner peripheral portion of the case 1 .
- Vanes 7 a to 7 d that divide the four hydraulic chambers formed by the shoes 3 a to 3 d of the case 1 into advance-side hydraulic chambers 5 a to 5 d and retard-side hydraulic chambers 6 a to 6 d, and that are also hydraulic pressure reception portions are disposed on the outer side of a rotor 4 at intervals of substantially 90 degrees.
- a boss portion 9 is in sliding contact with an inner sliding portion 8 of the case 1 having a predetermined clearance, and has oil seal and bearing functions.
- a recess is formed on the tip portion of the vanes 7 a to 7 d, and a seal member 10 for restricting a flow of oil between the hydraulic chambers is disposed thereon.
- the rotor 4 is inserted into a camshaft (not shown) inside the boss portion 9 and fastened fixedly by a bolt (not shown). As shown in FIG. 2 , the end surfaces of the case 1 and the rotor 4 are sealed by a cover 11 and a housing 12 , and these are fastened by four bolts 13 .
- advance-side passages 17 a to 17 d and retard-side passages 18 a to 18 d are provided in the boss portion 9 of the rotor 4 , each formed to penetrate the boss portion 9 in a radial direction to communicate with an oil passage (not shown) formed in the camshaft, and are communicated respectively with the advance-side hydraulic chamber 5 a to 5 d and the retard-side hydraulic chambers 6 a to 6 d, so that working oil can be supplied to the hydraulic chambers.
- a hole 21 penetrated in the radial direction is formed in the shoe 3 b of the case 1 ; when fitted into a fitting hole 22 formed in the boss portion 9 of the rotor 4 , a lock pin 23 restricts the rotor 4 at the most advanced position that is a startup reference position, and is accommodated therein to be movable in an axial direction.
- the lock pin 23 is urged in a fitting direction by a spring 24 , and the spring 24 is held by a stopper 25 .
- a retard-side hydraulic pressure is exerted on the lock pin 23 through a retard-side oil passage 26 opened at the bottom portion of the fitting hole 22 , and when the hydraulic pressure is received at the tip portion thereof, the lock pin 23 retreats in a radial outward direction against the spring 24 , thereby releasing the restriction on the rotor 4 .
- an assist spring 27 for urging the rotor 4 in the advance direction will be described.
- Recesses 28 , 29 penetrated in the axial direction are formed respectively in the vane 7 a (to 7 d ) of the rotor 4 and the shoe 3 a (to 3 d ) of the case 1 , and holding members 30 , 31 made of resin are inserted respectively into the recesses 28 , 29 .
- the assist spring 27 is inserted into assist spring insertion holes 32 , 33 formed on the sides of the holding members 30 , 31 .
- the assist spring 27 is disposed in the advance-side hydraulic chamber.
- two assist springs 27 are disposed in each hydraulic chamber for a total of eight assist springs 27 .
- the assist spring 27 In the most advanced position where a set length of the assist spring 27 is lengthened at a maximum, the assist spring 27 is disposed in a straight line, in view of ease of assembly thereof so that an assembly of the pair of holding members and the assist spring 27 can be inserted easily using a machine, and also with the aim of preventing an inconvenience in which the assist spring 27 is displaced in the radial direction to be deformed due to shortage of a support length provided by the holding members relative to the set length.
- a bottom surface: P of the holding member 30 and a bottom surface: Q of the holding member 31 are disposed to be parallel to each other.
- the assist spring 27 is disposed to be in an arc shape that warps toward the inside of the apparatus.
- a taper 35 for narrowing an opening is formed as a falling-out prevention portion in an opening edge portion of the recess 28 provided in the vane 7 a (to 7 d ) on the side of the rotation-operating rotor, and a taper 34 that comes in contact with the taper 35 , as shown in FIG. 4 , is formed on the two sides of the holding member 30 . In this manner, the holding member 30 can be prevented from falling out of the recess 28 mistakenly during a rotor operation.
- the aim of disposing the holding members 30 , 31 is to facilitate the ease of assembly when the plurality of assist springs 27 are disposed in the irregularly shaped space of the hydraulic chambers. Therefore, a predetermined gap is set between the holding members 30 , 31 and the recesses 28 , 29 , respectively, so that the holding members can be inserted easily therein. As a result of this gap, it is configured that the holding members 30 , 31 have backlash within the recesses 28 , 29 , respectively, whereby the holding members 30 , 31 can produce tilts in longitudinal and latitudinal directions by the gap.
- the holding members 30 , 31 are formed out of resin, and a linear expansion coefficient thereof is larger than that of the case 1 (made of an iron-based sintered metal in the first embodiment) forming the space into which the holding members are inserted; thus, the dimension of the holding members 30 , 31 in the axial direction of the apparatus is set to be smaller than that of the case 1 by an amount: AT corresponding to the difference in the linear expansion coefficient such that the holding members 30 , 31 are not stretched within the case 1 at the time of the thermal expansion.
- the dimension of the holding members 30 , 31 in the axial direction of the apparatus is apparently larger than that of the vertical case, and as a result of such an expansion of the dimension, the holding members 30 , 31 may be stretched within the case 1 .
- Such a condition occurs on the rotor side, which may cause the reduction in the operating speed, the wear of the cover 11 and housing 12 , and so on due to an increase in the frictional force.
- a clearance between the holding members 30 , 31 and the cover 11 and housing 12 is set at ( ⁇ T+ ⁇ C) or more in consideration of an increment: ⁇ C in the dimension in the axial direction of the apparatus due to the tilt of the holding member 30 .
- the thermal expansion ⁇ T of the holding member 30 is 40 ⁇ m at the maximum, and the tilt ⁇ C is 90 ⁇ m at the maximum.
- a tapered portion 36 of which the width: Lh is greater than a wire-to-wire distance: Ls of the assist spring 27 in the most advanced position (Lh>Ls) is formed in the inlets of the assist spring insertion holes 32 , 33 in the holding members 30 , 31 .
- the assist spring 27 is gradually compressed with being deformed into an arc shape as the rotor 4 operates in the retard direction from the most advanced position (i.e. the wire-to-wire distance of the assist spring is reduced).
- an assist spring wire is not caught on the edge of the inlet portion of the holding member 30 , and the assist spring 27 can be held with stability.
- valve timing adjusting apparatus when the valve timing adjusting apparatus is controlled to the most advanced position that is a reference position during engine startup, idling or the like, an oil control valve (not shown) is not energized; hydraulic pressure is not supplied to the advance-side hydraulic chambers 5 through an in-engine advance-side passage (not shown), and the rotor 4 is fixed in the most advanced position.
- the bottom surfaces P, Q of the holding members 30 , 31 are parallel to each other and the assist spring 27 is disposed in a straight line, as shown in FIG. 1 . Further, the lock pin 23 is fitted into the fitting hole 22 .
- the retard-side passages 18 a to 18 d are closed by the shoe portions of the case 1 , and therefore hydraulic pressure is not supplied to the retard-side hydraulic chambers 6 .
- the rotor 4 is swung by cam alternating torque; thus, the closed retard-side passages are opened, so that the oil is supplied to the retard-side hydraulic chambers.
- the aim of disposing the holding members is to enhance the ease of attachment of the assist springs, it is configured that a predetermined gap is arranged between the holding members and the recesses in the vane and the shoe, so that the holding members can tilt within the range of the gap.
- the rotor and case are formed out of iron-based materials and thus have a smaller linear expansion coefficient than the holding members made of resin) or the tilts on the attachment of the holding members and the assist springs, the tilts due to rotor operations or vibrations, and so on, the holding members are fallen in a stretched state between the cover and the housing at the two ends, which leads to inconveniences such as the reduction in the rotor operating speed due to the friction and an increase in leakage due to the wear on the sliding surface of the cover; however, the clearance formed by the length in the axial direction of the holding member provided on the vane side and also the length in the axial direction of the case is set to be equal to or greater than the sum of an increment of the length in the axial direction in consideration of the tilt of the holding member produced by the gap between the holding member and the recess, and an increment due to the thermal expansion, and therefore the above conveniences can be prevented.
- the falling-out prevention means of the holding member is provided on the rotor side to thus prevent the holding member from tilting, the following inconvenience, for example, can be prevented: the holding member cannot keep up with the rotor which carries out a rapid advance operation under a high hydraulic pressure, resulting in falling out.
- the width of the taper provided in the inlet of the assist spring insertion hole of the holding member is set to be larger than the assist spring wire-to-wire distance in the most advanced position, even when the assist spring wire traverses the inlet portion of the holding member due to the tilt of the holding member and/or the compression of the assist spring accompanied by a rotor operation, no assist spring wire is caught on the edge of the inlet portion of the holding member; thus, a correct load of the assist spring can be generated, and the inclination of the holding member can also be suppressed. Moreover, the wear in the event that the outer side of the assist spring wire rubs against the inlet can be suppressed.
- the assist spring in the most advanced position where the set length of the assist spring is at a maximum, the assist spring is disposed to be in a straight line; therefore, the assist spring and holding member can be set with stability such that the backlash (tilt) of the holding member during the assembly can be suppressed to a minimum. Furthermore, since the assist spring is disposed to be in a straight line in the most unstable and easily deformed state such that the set length of the assist spring is at a maximum, the assist spring can be prevented from deforming into a U-shape.
- valve timing adjusting apparatus of the present invention is effective when applied to be attached to the camshaft on the exhaust side of the internal combustion engine to control opening and closing timings of the exhaust valve.
Abstract
A valve timing adjusting apparatus includes: recesses provided opposite to the wall surfaces in a circumferential direction of a shoe and a vane in an advance hydraulic chamber; a holding member insertion-disposed into the recesses from an axial direction; and an assist spring disposed between the holding member on the shoe side and the holding member on the vane side to urge a rotor in an advance direction, and further a clearance formed by a length in the axial direction of the holding member provided on the vane side and a length in the axial direction of the case is set to not less than a sum of an increment of the length in the axial direction in consideration of a tilt of the holding member produced by a gap between the holding member and recess, and an increment due to the thermal expansion.
Description
- The present invention relates to a valve timing adjusting apparatus that changes automatically opening and closing timings of an exhaust valve in response to an operating condition of an internal combustion engine.
- This type of valve timing adjusting apparatus includes: a camshaft for driving an exhaust valve of an internal combustion engine to open and close; a case that is rotatably provided on the camshaft and rotationally driven by an output of the internal combustion engine; a rotor that is relatively rotatably housed inside the case and coupled to the camshaft; and a locking means that constrains a relative rotation between the case and the rotor when operated by a mechanical urging force, and releases the constraint when operated by a fluid control pressure applied from an internal hydraulic chamber in a direction opposing the mechanical urging force.
- With the aim of applying the thus constructed valve timing adjusting apparatus to an exhaust side thereof, it has been proposed that an assist spring is disposed as a urging means for urging the rotor in an advance direction within the internal hydraulic chamber.
Patent Document 1, for example, discloses a constitution for holding the assist spring in which a resin holding member is inserted into recesses provided in the rotor and the case. - Patent Document 1: Japanese Patent Publication No. 3,964,207
- As described above,
Patent Document 1 discloses that one pair of holding members are set to hold the two ends of the assist spring, but provides no detailed descriptions of an axial direction length of the holding members or an inlet shape of an assist spring insertion hole. Therefore, in a practical use, the holding member may tilt within the range of a gap between the holding member and the recess or is fallen in a stretched state between a cover and a housing at the two ends thereof due to the thermal expansion or the like; thus, there is a problem such that inconveniences such as a reduction in a rotor operating speed due to the friction and an increase in leakage due to the wear on the sliding surface between the cover and the housing are concerned. - The present invention has been made to solve the aforementioned problem that is caused by a holding member for holding an assist spring disposed in an hydraulic chamber, and an object thereof is to provide a valve timing adjusting apparatus in which decrease in the operating speed, reduction in the durability and so on are solved.
- A valve timing adjusting apparatus according to the present invention includes: a plurality of shoes formed on an inner peripheral surface of a case; a plurality of vanes provided on an outer peripheral surface of a rotor relatively rotatably housed in the case, each forming a retard hydraulic chamber and an advance hydraulic chamber between the vane and the two side-wall surfaces in a circumferential direction of the corresponding shoe; recesses provided opposite to the wall surfaces in the circumferential direction of the shoe and the vane in the advance hydraulic chamber; a holding member insertion-disposed into the recess from an axial direction; and an assist spring disposed between the holding member on the shoe side and the holding member on the vane side to urge the rotor in an advance direction, wherein a clearance formed by a length in the axial direction of the holding member provided on the vane side and a length in the axial direction of the case is set to be equal to or greater than a sum of an increment of the length in the axial direction in consideration of a tilt of the holding member produced by a gap between the holding member and the recess, and an increment due to the thermal expansion.
- According to the invention, in order to enhance the ease of attachment of the assist spring, it is configured that the clearance formed by the length in the axial direction of the holding member provided on the vane side and the length in the axial direction of the case is set to be equal to or greater than the sum of the increment of the length in the axial direction in consideration of the tilt of the holding member produced by the gap between the holding member and the recess, and the increment due to the thermal expansion; thus, even when the holding member tilts within the range of the gap provided between the member and the recess in the vane or shoe, or even when there occurs the tilt due to the thermal expansion upon an increase of oil temperature (the rotor and case are formed out of iron-based materials and have a smaller linear expansion coefficient than the holding member made of resin), the tilt of the holding member during the assembly of the member and the assist spring, or the tilt due to rotor operations or vibrations; the following inconveniences can be prevented reliably: the occurrence of a stretched state between a cover and a housing at the two ends, the reduction in the rotor operating speed due to the friction, the increase in leakage due to the wear on the sliding surface of the cover, and so on.
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FIG. 1 is a radial direction sectional view of a valve timing adjusting apparatus of a first embodiment of the present invention, taken along a line 2-2 inFIG. 2 . -
FIG. 2 is an axial direction sectional view of the valve timing adjusting apparatus of the first embodiment of the present invention, taken along a line 1-1 inFIG. 1 . -
FIG. 3 is a front view showing a condition in which an assist spring is attached to an assist spring insertion hole provided in a holding member inserted into a recess of a vane. -
FIG. 4 is a longitudinal sectional side view taken along a line 3-3 inFIG. 3 . - In the following, to describe the present invention in further detail, an embodiment of the invention will be described with reference to the attached drawings.
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FIG. 1 is a radial direction sectional view of a valve timing adjusting apparatus of a first embodiment in the present invention, taken along a line 2-2 inFIG. 2 , andFIG. 2 is an axial direction sectional view of the valve timing adjusting apparatus of the first embodiment in the invention, taken along a line 1-1 inFIG. 1 . - In the drawings, a
sprocket portion 2 for transmitting a driving force from a crank (not shown) is formed on the outer periphery of acase 1, andshoes 3 a to 3 d forming hydraulic chambers are provided in the inner peripheral portion of thecase 1. Vanes 7 a to 7 d that divide the four hydraulic chambers formed by theshoes 3 a to 3 d of thecase 1 into advance-sidehydraulic chambers 5 a to 5 d and retard-sidehydraulic chambers 6 a to 6 d, and that are also hydraulic pressure reception portions are disposed on the outer side of arotor 4 at intervals of substantially 90 degrees. In therotor 4, aboss portion 9 is in sliding contact with an inner slidingportion 8 of thecase 1 having a predetermined clearance, and has oil seal and bearing functions. - Further, a recess is formed on the tip portion of the
vanes 7 a to 7 d, and aseal member 10 for restricting a flow of oil between the hydraulic chambers is disposed thereon. Further, therotor 4 is inserted into a camshaft (not shown) inside theboss portion 9 and fastened fixedly by a bolt (not shown). As shown inFIG. 2 , the end surfaces of thecase 1 and therotor 4 are sealed by acover 11 and ahousing 12, and these are fastened by fourbolts 13. - Hereinafter, oil passages formed in the
rotor 4 will be described. It is configured that advance-side passages 17 a to 17 d and retard-side passages 18 a to 18 d are provided in theboss portion 9 of therotor 4, each formed to penetrate theboss portion 9 in a radial direction to communicate with an oil passage (not shown) formed in the camshaft, and are communicated respectively with the advance-sidehydraulic chamber 5 a to 5 d and the retard-sidehydraulic chambers 6 a to 6 d, so that working oil can be supplied to the hydraulic chambers. - A
hole 21 penetrated in the radial direction is formed in theshoe 3 b of thecase 1; when fitted into afitting hole 22 formed in theboss portion 9 of therotor 4, alock pin 23 restricts therotor 4 at the most advanced position that is a startup reference position, and is accommodated therein to be movable in an axial direction. Thelock pin 23 is urged in a fitting direction by aspring 24, and thespring 24 is held by astopper 25. Further, a retard-side hydraulic pressure is exerted on thelock pin 23 through a retard-side oil passage 26 opened at the bottom portion of thefitting hole 22, and when the hydraulic pressure is received at the tip portion thereof, thelock pin 23 retreats in a radial outward direction against thespring 24, thereby releasing the restriction on therotor 4. - Next, an
assist spring 27 for urging therotor 4 in the advance direction will be described. Recesses 28, 29 penetrated in the axial direction are formed respectively in thevane 7 a (to 7 d) of therotor 4 and theshoe 3 a (to 3 d) of thecase 1, and holdingmembers recesses assist spring 27 is inserted into assistspring insertion holes holding members - In such a way, the
assist spring 27 is disposed in the advance-side hydraulic chamber. In the illustrated example, twoassist springs 27 are disposed in each hydraulic chamber for a total of eightassist springs 27. In the most advanced position where a set length of theassist spring 27 is lengthened at a maximum, theassist spring 27 is disposed in a straight line, in view of ease of assembly thereof so that an assembly of the pair of holding members and theassist spring 27 can be inserted easily using a machine, and also with the aim of preventing an inconvenience in which theassist spring 27 is displaced in the radial direction to be deformed due to shortage of a support length provided by the holding members relative to the set length. In other words, inFIG. 1 , a bottom surface: P of theholding member 30 and a bottom surface: Q of theholding member 31 are disposed to be parallel to each other. - In the most retarded position where the set length of the
assist spring 27 is shortened at a minimum, theassist spring 27 is disposed to be in an arc shape that warps toward the inside of the apparatus. Further, ataper 35 for narrowing an opening is formed as a falling-out prevention portion in an opening edge portion of therecess 28 provided in thevane 7 a (to 7 d) on the side of the rotation-operating rotor, and ataper 34 that comes in contact with thetaper 35, as shown inFIG. 4 , is formed on the two sides of theholding member 30. In this manner, theholding member 30 can be prevented from falling out of therecess 28 mistakenly during a rotor operation. - The aim of disposing the
holding members assist springs 27 are disposed in the irregularly shaped space of the hydraulic chambers. Therefore, a predetermined gap is set between theholding members recesses holding members recesses holding members - Hereupon, the
holding members holding members case 1 by an amount: AT corresponding to the difference in the linear expansion coefficient such that theholding members case 1 at the time of the thermal expansion. - However, when the tilts of the
holding member 30 discussed above are produced, as shown inFIG. 3 , the dimension of theholding members holding members case 1. Such a condition occurs on the rotor side, which may cause the reduction in the operating speed, the wear of thecover 11 andhousing 12, and so on due to an increase in the frictional force. - In other words, when glass or the like, for example, is used in the
holding member 30 as an add-in material to suppress the wear on the bearing surface of theassist spring 27, the wear on the other material is developed remarkably. In the first embodiment, a clearance between theholding members cover 11 andhousing 12 is set at (ΔT+ΔC) or more in consideration of an increment: ΔC in the dimension in the axial direction of the apparatus due to the tilt of theholding member 30. Note that the thermal expansion ΔT of theholding member 30 is 40 μm at the maximum, and the tilt ΔC is 90 μm at the maximum. With such a configuration, theholding members case 1 notwithstanding the backlash, so that the stable operability and durability of the apparatus can be obtained. - Further, as shown in
FIG. 4 , atapered portion 36 of which the width: Lh is greater than a wire-to-wire distance: Ls of theassist spring 27 in the most advanced position (Lh>Ls) is formed in the inlets of the assistspring insertion holes holding members assist spring 27 is gradually compressed with being deformed into an arc shape as therotor 4 operates in the retard direction from the most advanced position (i.e. the wire-to-wire distance of the assist spring is reduced). However, an assist spring wire is not caught on the edge of the inlet portion of theholding member 30, and theassist spring 27 can be held with stability. - Next, an operation of the apparatus will be described. First, when the valve timing adjusting apparatus is controlled to the most advanced position that is a reference position during engine startup, idling or the like, an oil control valve (not shown) is not energized; hydraulic pressure is not supplied to the advance-side hydraulic chambers 5 through an in-engine advance-side passage (not shown), and the
rotor 4 is fixed in the most advanced position. At this time, the bottom surfaces P, Q of theholding members assist spring 27 is disposed in a straight line, as shown inFIG. 1 . Further, thelock pin 23 is fitted into thefitting hole 22. - Subsequently, when a retard operation command is issued to the valve timing adjusting apparatus in response to an increase in the RPM (revolutions per minute) or the like, a predetermined current is applied to the oil control valve; as a result, a retard-side output port is opened, so that oil is initially supplied to the retard-
side oil passage 26 of the valve timing adjusting apparatus through an in-engine retard-side passage (not shown); the pressure is received at the tip portion of thelock pin 23, so that thelock pin 23 is displaced in the radially outward direction against the urging force of thespring 24 to be drawn from thefitting hole 22, to thus release the restriction on therotor 4. - Hereupon, in the fitting position of the
lock pin 23, the retard-side passages 18 a to 18 d are closed by the shoe portions of thecase 1, and therefore hydraulic pressure is not supplied to the retard-side hydraulic chambers 6. When thelock pin 23 is released, therotor 4 is swung by cam alternating torque; thus, the closed retard-side passages are opened, so that the oil is supplied to the retard-side hydraulic chambers. - When the oil is supplied to the retard-side hydraulic chambers, rotary torque is generated in the
rotor 4 in the retard direction; thus, therotor 4 begins to operate against the torque of the assist spring in the advance direction, in combination with the cam torque in the retard direction. At this time, even when the tilts of the holdingmembers recesses members members case 1, and therotor 4 can operate normally. - As described above, according to the first embodiment, since the aim of disposing the holding members is to enhance the ease of attachment of the assist springs, it is configured that a predetermined gap is arranged between the holding members and the recesses in the vane and the shoe, so that the holding members can tilt within the range of the gap. In doing so, however, due to the tilts of the holding members caused by the thermal expansion upon an increase of oil temperature (the rotor and case are formed out of iron-based materials and thus have a smaller linear expansion coefficient than the holding members made of resin) or the tilts on the attachment of the holding members and the assist springs, the tilts due to rotor operations or vibrations, and so on, the holding members are fallen in a stretched state between the cover and the housing at the two ends, which leads to inconveniences such as the reduction in the rotor operating speed due to the friction and an increase in leakage due to the wear on the sliding surface of the cover; however, the clearance formed by the length in the axial direction of the holding member provided on the vane side and also the length in the axial direction of the case is set to be equal to or greater than the sum of an increment of the length in the axial direction in consideration of the tilt of the holding member produced by the gap between the holding member and the recess, and an increment due to the thermal expansion, and therefore the above conveniences can be prevented.
- Further, since it is configured that the falling-out prevention means of the holding member is provided on the rotor side to thus prevent the holding member from tilting, the following inconvenience, for example, can be prevented: the holding member cannot keep up with the rotor which carries out a rapid advance operation under a high hydraulic pressure, resulting in falling out.
- Furthermore, since the width of the taper provided in the inlet of the assist spring insertion hole of the holding member is set to be larger than the assist spring wire-to-wire distance in the most advanced position, even when the assist spring wire traverses the inlet portion of the holding member due to the tilt of the holding member and/or the compression of the assist spring accompanied by a rotor operation, no assist spring wire is caught on the edge of the inlet portion of the holding member; thus, a correct load of the assist spring can be generated, and the inclination of the holding member can also be suppressed. Moreover, the wear in the event that the outer side of the assist spring wire rubs against the inlet can be suppressed.
- Further, it is configured that in the most advanced position where the set length of the assist spring is at a maximum, the assist spring is disposed to be in a straight line; therefore, the assist spring and holding member can be set with stability such that the backlash (tilt) of the holding member during the assembly can be suppressed to a minimum. Furthermore, since the assist spring is disposed to be in a straight line in the most unstable and easily deformed state such that the set length of the assist spring is at a maximum, the assist spring can be prevented from deforming into a U-shape.
- The valve timing adjusting apparatus of the present invention is effective when applied to be attached to the camshaft on the exhaust side of the internal combustion engine to control opening and closing timings of the exhaust valve.
Claims (4)
1. A valve timing adjusting apparatus having: a camshaft that drive a valve of an internal combustion engine to open and close; a case that has a plurality of shoes on an inner peripheral surface thereof, is rotatably provided on the camshaft, and is rotationally driven by an output of the internal combustion engine, and; a rotor that has a plurality of vanes provided on an outer peripheral surface thereof, each forming a retard hydraulic chamber and an advance hydraulic chamber between the vane and two side-wall surfaces in a circumferential direction of the corresponding shoe, is relatively rotatably housed in the case, and is coupled to the camshaft, comprising:
recesses provided opposite to the wall surfaces in the circumferential direction of the shoe and the vane in the advance hydraulic chamber;
a holding member insertion-disposed into each of the recesses from an axial direction of the rotor; and
an assist spring disposed between the holding member on the shoe side and the holding member on the vane side to urge the rotor in an advance direction,
wherein a clearance formed by a length in the axial direction of the rotor of the holding member provided on the vane side and a length in the axial direction of the rotor of the case is set to be equal to or greater than a sum of an increment of the length in the axial direction of the rotor in consideration of a tilt of the holding member produced by a gap between the holding member and the recess, and an increment due to thermal expansion thereof.
2. The valve timing adjusting apparatus according to claim 1 , wherein a falling-out prevention portion for narrowing an opening is provided on the recess provided on the wall surface in the circumferential direction of the vane, and a first tapered portion that comes into contact with the falling-out prevention portion is formed on the holding member.
3. The valve timing adjusting apparatus according to claim 1 , wherein a width in the axial direction of the assist spring of a second tapered portion provided on the holding member is set to be greater than a wire-to-wire distance of the assist spring when the assist spring is set in the most advanced position.
4. The valve timing adjusting apparatus according to claim 1 , wherein the bottom surfaces of the holding members on the shoe side and on the vane side are parallel to each other in the most advanced position where a set length of the assist spring is at a maximum.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
PCT/JP2009/004859 WO2011036720A1 (en) | 2009-09-25 | 2009-09-25 | Valve timing regulator |
Publications (1)
Publication Number | Publication Date |
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US20120167846A1 true US20120167846A1 (en) | 2012-07-05 |
Family
ID=43795493
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
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US13/376,101 Abandoned US20120167846A1 (en) | 2009-09-25 | 2009-09-25 | Valve timing regulator |
Country Status (5)
Country | Link |
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US (1) | US20120167846A1 (en) |
JP (1) | JP5335094B2 (en) |
CN (1) | CN102472125B (en) |
DE (1) | DE112009005364B4 (en) |
WO (1) | WO2011036720A1 (en) |
Families Citing this family (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE102012209532A1 (en) * | 2012-06-06 | 2013-12-12 | Schaeffler Technologies AG & Co. KG | Rotor for a hydraulic camshaft adjuster |
DE102012217394A1 (en) * | 2012-09-26 | 2014-03-27 | Schaeffler Technologies Gmbh & Co. Kg | Phaser |
CN105332759B (en) * | 2014-07-30 | 2019-07-16 | 舍弗勒技术股份两合公司 | Camshaft phase adjuster and its assemble method |
DE102018103029A1 (en) * | 2018-02-12 | 2019-08-14 | ECO Holding 1 GmbH | Camshaft adjuster with compensation bearing |
JP7001023B2 (en) * | 2018-08-31 | 2022-01-19 | 株式会社デンソー | Valve timing adjuster |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6450138B1 (en) * | 2000-01-25 | 2002-09-17 | Mitsubishi Denki Kabushiki Kaisha | Valve timing adjusting device |
US6591799B1 (en) * | 2000-07-10 | 2003-07-15 | Mitsubishi Denki Kabushiki Kaisha | Valve timing adjusting device |
US7011058B2 (en) * | 2003-06-05 | 2006-03-14 | Mitsubishi Denki Kabushiki Kaisha | Valve timing adjusting device |
JP2007291889A (en) * | 2006-04-21 | 2007-11-08 | Mitsubishi Electric Corp | Valve timing adjustment device |
US20080245328A1 (en) * | 2004-08-27 | 2008-10-09 | Koji Yudate | Valve Timing Adjusting Device |
Family Cites Families (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2002122009A (en) * | 2000-08-09 | 2002-04-26 | Mitsubishi Electric Corp | Valve timing adjusting device |
JP2005155373A (en) * | 2003-11-21 | 2005-06-16 | Mitsubishi Electric Corp | Valve timing adjusting device |
JP2006083785A (en) * | 2004-09-17 | 2006-03-30 | Hitachi Ltd | Valve timing control device of internal combustion engine |
JP2007023953A (en) * | 2005-07-20 | 2007-02-01 | Denso Corp | Valve timing adjustment device |
JP4837099B2 (en) * | 2007-08-08 | 2011-12-14 | 三菱電機株式会社 | Valve timing adjusting device and assembly method thereof |
-
2009
- 2009-09-25 JP JP2011532802A patent/JP5335094B2/en active Active
- 2009-09-25 WO PCT/JP2009/004859 patent/WO2011036720A1/en active Application Filing
- 2009-09-25 US US13/376,101 patent/US20120167846A1/en not_active Abandoned
- 2009-09-25 CN CN200980160687.2A patent/CN102472125B/en active Active
- 2009-09-25 DE DE112009005364.5T patent/DE112009005364B4/en active Active
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6450138B1 (en) * | 2000-01-25 | 2002-09-17 | Mitsubishi Denki Kabushiki Kaisha | Valve timing adjusting device |
US6591799B1 (en) * | 2000-07-10 | 2003-07-15 | Mitsubishi Denki Kabushiki Kaisha | Valve timing adjusting device |
US7011058B2 (en) * | 2003-06-05 | 2006-03-14 | Mitsubishi Denki Kabushiki Kaisha | Valve timing adjusting device |
US20080245328A1 (en) * | 2004-08-27 | 2008-10-09 | Koji Yudate | Valve Timing Adjusting Device |
JP2007291889A (en) * | 2006-04-21 | 2007-11-08 | Mitsubishi Electric Corp | Valve timing adjustment device |
Also Published As
Publication number | Publication date |
---|---|
JP5335094B2 (en) | 2013-11-06 |
CN102472125B (en) | 2016-04-20 |
DE112009005364T5 (en) | 2013-03-28 |
CN102472125A (en) | 2012-05-23 |
JPWO2011036720A1 (en) | 2013-02-14 |
WO2011036720A1 (en) | 2011-03-31 |
DE112009005364B4 (en) | 2016-06-09 |
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Owner name: MITSUBISHI ELECTRIC CORPORATION, JAPAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:HASE, HIROFUMI;REEL/FRAME:027323/0169 Effective date: 20111111 |
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STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |