WO2010004909A1 - Lash adjuster - Google Patents
Lash adjuster Download PDFInfo
- Publication number
- WO2010004909A1 WO2010004909A1 PCT/JP2009/061931 JP2009061931W WO2010004909A1 WO 2010004909 A1 WO2010004909 A1 WO 2010004909A1 JP 2009061931 W JP2009061931 W JP 2009061931W WO 2010004909 A1 WO2010004909 A1 WO 2010004909A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- screw
- lash adjuster
- nut member
- cam
- valve
- Prior art date
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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
- F01L1/20—Adjusting or compensating clearance
- F01L1/22—Adjusting or compensating clearance automatically, e.g. mechanically
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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
- F01L1/12—Transmitting gear between valve drive and valve
- F01L1/14—Tappets; Push rods
- F01L1/143—Tappets; Push rods for use with overhead camshafts
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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
- F01L1/12—Transmitting gear between valve drive and valve
- F01L1/18—Rocking arms or levers
- F01L1/181—Centre pivot rocking arms
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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
- F01L1/12—Transmitting gear between valve drive and valve
- F01L1/18—Rocking arms or levers
- F01L1/185—Overhead end-pivot rocking arms
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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
- F01L1/02—Valve drive
- F01L1/04—Valve drive by means of cams, camshafts, cam discs, eccentrics or the like
- F01L1/047—Camshafts
- F01L1/053—Camshafts overhead type
- F01L1/0532—Camshafts overhead type the cams being directly in contact with the driven valve
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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
- F01L2305/00—Valve arrangements comprising rollers
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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
- F01L3/00—Lift-valve, i.e. cut-off apparatus with closure members having at least a component of their opening and closing motion perpendicular to the closing faces; Parts or accessories thereof
- F01L3/08—Valves guides; Sealing of valve stem, e.g. sealing by lubricant
Definitions
- This invention relates to a lash adjuster incorporated in an engine valve gear.
- a lash adjuster is generally incorporated in the valve operating device, and the lash adjuster absorbs the change in the gap between the components of the valve operating device.
- a lash adjuster in the above swing arm type valve gear, a nut member having a female screw on the inner periphery, an adjustment screw having a male screw engaged with the female screw on the outer periphery, and a nut member connected to the adjustment screw.
- a torsion spring that applies a rotational force in a protruding direction, and the adjustment screw receives a load applied to a swing fulcrum of an arm that swings in accordance with the rotation of a cam (Patent Document 1). ).
- a nut member having a female screw on the inner periphery an adjustment screw having a male screw threadedly engaged with the female screw on the outer periphery, and a rotational force in a direction projecting from the nut member to the adjustment screw
- the adjustment screw receives a load applied between an arm that swings in response to rotation of a cam and a valve stem that is pushed down by the arm (patent) Reference 1).
- these lash adjusters may move in the protruding direction while rotating due to the force of the torsion spring and come off the nut member when vibration is applied with the load in the pushing direction against the adjusting screw being released. .
- the adjustment screw may come off from the nut member.
- the adjustment screw comes off, if the adjustment screw enters the engine, it is difficult to pick up the adjustment screw, which is complicated. Further, if the parts are completely separated, reassembly becomes complicated and may be lost in some cases.
- the problem to be solved by the present invention is to provide a lash adjuster in which an adjusting screw is difficult to come off from a nut member during assembly or maintenance of an engine.
- a nut member having an internal thread on the inner periphery, an adjustment screw having an external thread that engages with the internal thread on the outer periphery, and a rotational force in a direction protruding from the nut member is applied to the adjustment screw.
- a lash adjuster having a torsion spring when the adjustment screw is rotated until the torsion spring is restored to a free state (that is, a state where the rotational force applied to the adjustment screw becomes zero), the male screw and the female screw are at least Screws were engaged with a length of 1 pitch or more.
- the present invention can be applied to, for example, the following lash adjuster.
- a lash adjuster for a swing arm type valve operating apparatus in which the adjusting screw receives a load applied to a swing fulcrum of an arm that swings in accordance with the rotation of a cam.
- a lash adjuster of a rocker arm type valve gear that receives a load applied between an arm in which the adjusting screw swings according to rotation of a cam and a valve stem pushed down by the arm.
- a lash adjuster for a direct type valve operating device in which the adjusting screw receives a load applied between a lifter body that slides up and down according to the rotation of the cam and a valve stem that is pushed down by the lifter body.
- the torsion spring includes, for example, a torsion coil spring.
- the male screw and the female screw may be any of a sawtooth screw, a triangular screw, and a trapezoidal screw.
- the male screw of the adjustment screw and the female screw of the nut member are screw-engaged with a length of at least one pitch. Therefore, it is possible to prevent the adjustment screw from being detached from the nut member during assembly or maintenance of the engine.
- FIG. 1 is an enlarged cross-sectional view in the vicinity of a lash adjuster showing a state where the torsion coil spring shown in FIG. 1 is restored to a free state.
- FIG. 3 is an enlarged cross-sectional view of the vicinity of the lash adjuster showing a state where the torsion coil spring shown in FIG. 3 is restored to a free state.
- FIG. 5 is an enlarged cross-sectional view of the vicinity of the lash adjuster showing a state where the torsion coil spring shown in FIG. 5 is restored to a free state.
- FIG. 1 shows a valve gear incorporating a lash adjuster 1 according to the first embodiment of the present invention.
- This valve operating apparatus has a valve 4 provided in an intake port 3 of an engine cylinder head 2, a valve stem 5 connected to the valve 4, and an arm 7 that swings in response to rotation of a cam 6. .
- the valve stem 5 extends upward from the valve 4 and slidably penetrates the cylinder head 2.
- An annular spring retainer 8 is fixed to the upper outer periphery of the valve stem 5, and a valve spring 9 is incorporated between the lower surface of the spring retainer 8 and the upper surface of the cylinder head 2.
- the valve spring 9 urges the valve stem 5 upward via the spring retainer 8, and the valve 4 is seated on the valve seat 10 by the urging force.
- the arm 7 has one end supported by the lash adjuster 1 so as to be swingable, and the other end in contact with the upper end of the valve stem 5.
- a roller 11 is attached to the central portion of the arm 7, and the roller 11 is in contact with a cam 6 provided above the arm 7.
- the cam 6 is integrally formed with a camshaft 12 that rotates in synchronization with the crankshaft (not shown) of the engine. When the camshaft 12 rotates, a cam crest 6b that is raised with respect to the base circle 6a is formed. The arm 7 is pushed down via the roller 11.
- the lash adjuster 1 includes a cylindrical nut member 14 that is inserted into a receiving hole 13 that is open on the upper surface of the cylinder head 2, and a female screw 15 that is formed on the inner periphery of the nut member 14.
- An adjusting screw 17 having a male screw 16 on the outer periphery of the lower portion thereof, and a torsion coil spring 18 for applying a rotational force to the adjusting screw 17.
- the lower end of the torsion coil spring 18 is inserted into a through hole 19 formed at the bottom of the nut member 14 and is prevented from rotating, and the upper end is a locking hole 20 formed in the adjustment screw 17. Due to the torsional deformation, the adjusting screw 17 is given a rotational force in the direction in which the adjusting screw 17 protrudes from the nut member 14. Further, when the adjusting screw 17 is rotated until the torsion coil spring 18 is restored to a free state (that is, a state where the rotational force applied to the adjusting screw 17 becomes zero), the male screw 16 and the female screw 15 are at least one pitch or more. It is incorporated so as to engage with a screw with a length of.
- the male screw 16 and the female screw 15 are formed in a sawtooth shape in which the flank angle of the pressure-side flank 21 that receives pressure when a load in the direction of pushing the adjusting screw 17 into the nut member 14 is applied is larger than the flank angle of the play-side flank 22. Has been.
- An oil drain hole 23 communicating with the through hole 19 is formed on the inner bottom surface of the accommodation hole 13. Therefore, the engine oil that has flowed into the nut member 14 from the upper end surface of the nut member 14 through the gap between the male screw 16 and the female screw 15 is discharged from the nut member 14 through the through hole 19 and the oil drain hole 23 in order. .
- the adjusting screw 17 has a protruding end 24 from the nut member 14 formed in a hemispherical shape, and the protruding end 24 is fitted into a recess 25 formed on the lower surface of the end of the arm 7.
- the load applied to the swing fulcrum of the arm 7 that swings according to the rotation of the cam 6 is received.
- the biasing force of the valve spring 9 acts on the adjustment screw 17 even when the base circle 6a of the cam 6 is at the position of the roller 11.
- the amount of protrusion of the adjusting screw 17 when the cam 6 rotates and the load in the pushing direction is released is smaller than the amount of pushing of the adjusting screw 17 when the cam crest 6b of the cam 6 pushes down the arm 7.
- the adjusting screw 17 moves by several microns in the pushing direction and the valve stem 5 rises, so that no gap is generated between the contact surfaces of the valve 4 and the valve seat 10.
- the lash adjuster 1 moves in the protruding direction while the adjustment screw 17 is rotated by the force of the torsion coil spring 18. At this time, the torsion coil spring 18 is moved. As shown in FIG. 2, the screw engagement between the male screw 16 and the female screw 15 is maintained even if the adjusting screw 17 rotates until the screw is restored to the free state. Therefore, it is possible to prevent the adjustment screw 17 from being detached from the nut member 14 during engine assembly or maintenance. Further, since there is no need to provide a member for preventing the adjustment screw 17 from coming off from the nut member 14, the assembly is simple.
- valve stem 35 extends upward from the valve 34, and a spring retainer 38 is fixed to the upper portion of the valve stem 35.
- the spring retainer 38 is urged upward by a valve spring 39, and the valve 34 is seated on the valve seat 40 by the urging force.
- the arm 37 is supported at the center by a fulcrum shaft 41 so as to be swingable.
- a roller 42 that contacts the cam 36 is attached to one end of the arm 37, and a lash adjuster 31 is incorporated into the other end of the arm 37.
- the cam 36 provided below the arm 37 is integrally formed with a camshaft 43 that rotates in synchronization with a crankshaft (not shown) of the engine. When the camshaft 43 rotates, the cam 36 rotates relative to the base circle 36a. The cam crest portion 36 b that is raised in this manner presses the roller 42 and swings the arm 37.
- the lash adjuster 31 includes a cylindrical nut member 45 inserted into the accommodation hole 44 opened on the lower surface of the arm 37, and a female screw 46 formed on the inner periphery of the nut member 45.
- An adjustment screw 48 having a male screw 47 that engages with the screw on the outer periphery, and a torsion coil spring 49 that applies a rotational force to the adjustment screw 48 are provided.
- the male screw 47 and the female screw 46 are vertically symmetrical triangular screws.
- the nut member 45 is prevented from rotating around the arm 37 by caulking the edge of the accommodation hole 44.
- the upper end of the torsion coil spring 49 is inserted into a through hole 50 formed in the inner bottom surface of the accommodation hole 44 and is prevented from rotating, and the lower end is engaged with an engagement hole 51 formed in the adjustment screw 48. Due to the torsional deformation, the adjusting screw 48 is applied with a rotational force in a direction protruding downward from the nut member 45. Further, when the adjusting screw 48 is rotated until the torsion coil spring 49 is restored to a free state (that is, a state where the rotational force applied to the adjusting screw 48 becomes zero), the male screw 47 and the female screw 46 are at least one pitch or more. It is incorporated so as to engage with a screw with a length of.
- the adjustment screw 48 has a protruding end from the nut member 45 abutting on the upper end of the valve stem 35 and receives a load applied between the arm 37 and the valve stem 35.
- the male screw 47 becomes the female screw 46, as in the first embodiment.
- the axial position of the adjusting screw 48 relative to the nut member 45 is fixed. Strictly, a slight slip occurs between the male screw 47 and the female screw 46 at this time, and the adjustment screw 48 moves in the pushing direction due to the slip, but the cam 36 further rotates to release the load in the pushing direction.
- the adjusting screw 48 moves in the protruding direction while rotating by the force of the torsion coil spring 49, and returns to the original position.
- the lash adjuster 31 moves in the protruding direction while the adjustment screw 48 is rotated by the force of the torsion coil spring 49. At this time, the torsion coil spring 49 is in a free state. Even if the adjusting screw 48 rotates until it is restored, the screw engagement between the male screw 47 and the female screw 46 is maintained as shown in FIG. Therefore, it is possible to prevent the adjustment screw 48 from being detached from the nut member 45 during engine assembly or maintenance. Further, since there is no need to provide a member for preventing the adjustment screw 48 from coming off the nut member 45, the assembly is simple.
- FIG. 5 shows a valve gear incorporating a lash adjuster 61 according to a third embodiment of the present invention.
- This valve operating apparatus has a valve 64 provided in the intake port 63 of the cylinder head 62 and a valve stem 65 connected to the valve 64.
- the valve stem 65 extends upward from the valve 64, and an annular spring retainer 66 is fixed to the upper outer periphery of the valve stem 65.
- the spring retainer 66 is urged upward by a valve spring 67, and the valve 64 is seated on the valve seat 68 by the urging force.
- the lifter body 70 includes a cylindrical portion 76 and an end plate 77 provided at the upper end of the cylindrical portion 76, and a cam 78 is in contact with the upper surface of the end plate 77.
- the cam 78 is integrally formed with a camshaft 79 that rotates in synchronization with the crankshaft (not shown) of the engine. When the camshaft 79 rotates, a cam crest 78b raised with respect to the base circle 78a is formed on the lifter body 70. Is to be pushed down.
- the nut member 71 is fixed to the lifter body 70 with a retaining ring 80.
- the male screw 73 and the female screw 72 are vertically symmetrical trapezoidal screws.
- the upper end of the torsion coil spring 75 is inserted into a locking groove 81 formed on the upper surface of the nut member 71 and is prevented from rotating, and the lower end is locked in a locking hole 82 formed in the adjusting screw 74. Due to the torsional deformation, a rotational force in a direction protruding downward from the nut member 71 is applied to the adjusting screw 74.
- the male screw 73 and the female screw 72 are at least one pitch or more. It is incorporated so as to engage with a screw with a length of.
- the adjustment screw 74 has a protruding end from the nut member 71 in contact with the upper end of the valve stem 65 via the spacer 83, and receives a load applied between the lifter body 70 and the valve stem 65. It is like that.
- the cam crest 78b of the cam 78 pushes down the lifter body 70 and a load in the pushing direction is applied to the adjusting screw 74, the male screw 73 is received by the female screw 72 as in the first embodiment.
- the axial position of the adjusting screw 74 with respect to the nut member 71 is fixed. Strictly, at this time, a slight slip occurs between the male screw 73 and the female screw 72, and the adjustment screw 74 moves in the pushing direction due to the slip, but the cam 78 further rotates to release the load in the pushing direction.
- the adjusting screw 74 moves in the protruding direction while rotating by the force of the torsion coil spring 75, and returns to the original position.
- the lash adjuster 61 moves in the protruding direction while the adjustment screw 74 is rotated by the force of the torsion coil spring 75. At this time, the torsion coil spring 75 is in a free state. Even if the adjusting screw 74 rotates until it is restored, the screw engagement between the male screw 73 and the female screw 72 is maintained as shown in FIG. Therefore, the adjustment screw 74 can be prevented from being detached from the nut member 71 during engine assembly or maintenance. Further, since there is no need to provide a member for preventing the adjustment screw 74 from coming off the nut member 71, the assembly is simple.
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Valve-Gear Or Valve Arrangements (AREA)
Abstract
Provided is a lash adjuster of which an adjustment screw does not easily come off a nut member during the assembling or maintenance of an engine.
In a lash adjuster comprising a nut member (14) having a female thread (15) on the inner circumference of same, an adjustment screw (17) having a male thread (16) on the outer circumference of same so as to engage with the female thread (15), and a torsion coil spring (18) for applying a torque to said adjustment screw (17) in a direction protruding from the nut member (14), the male thread (16) and the female thread (15) become engaged with each other by a length of at least one pitch or longer when the adjustment screw (17) is turned until the torsion coil spring (18) is restored to a liberated state.
Description
この発明は、エンジンの動弁装置に組み込まれるラッシュアジャスタに関する。
This invention relates to a lash adjuster incorporated in an engine valve gear.
エンジンの吸気ポートまたは排気ポートに設けたバルブを動作させる動弁装置として、上下にスライド可能に支持されたバルブリフタをカムで押し下げ、そのバルブリフタでバルブステムを押し下げるようにしたもの(ダイレクト式動弁装置)や、中央部を支点として揺動可能に支持されたアームの一端部をカムで押し上げ、そのアームの他端部でバルブステムを押し下げるようにしたもの(ロッカアーム式動弁装置)、一端部を支点として揺動可能に支持されたアームの中央部をカムで押し下げ、そのアームの他端部でバルブステムを押し下げるようにしたもの(スイングアーム式動弁装置)などが知られている。
As a valve operating device that operates a valve provided in the intake port or exhaust port of an engine, a valve lifter supported so as to be slidable up and down is pushed down by a cam, and the valve stem is pushed down by the valve lifter (direct valve operating device) ), One end of an arm supported so as to be swingable with the center as a fulcrum, and a valve stem pushed down at the other end of the arm (rocker arm type valve gear), one end Known is a swing arm type valve operating device in which a central portion of an arm supported as a fulcrum is pushed down by a cam and a valve stem is pushed down at the other end of the arm.
これらの動弁装置は、エンジン作動中、動弁装置の構成部材間に生じる熱膨張差によって、動弁装置の構成部材間の隙間が変化し、その隙間の変化によって異音や圧縮漏れを生じるおそれがある。また、動弁装置の摺動部が摩耗しても、動弁装置の構成部材間の隙間が変化し、その隙間の変化によって異音を生じるおそれがある。
In these valve operating apparatuses, during engine operation, gaps between the constituent members of the valve operating apparatus change due to thermal expansion differences that occur between the constituent members of the valve operating apparatus, and abnormal noise and compression leakage occur due to changes in the gaps. There is a fear. Further, even if the sliding portion of the valve operating device is worn, the gap between the constituent members of the valve operating device changes, and there is a possibility that abnormal noise is generated due to the change in the gap.
この異音や圧縮漏れを防止するため、一般に、動弁装置にはラッシュアジャスタが組み込まれ、そのラッシュアジャスタで動弁装置の構成部材間の隙間の変化を吸収する。
In order to prevent this abnormal noise and compression leakage, a lash adjuster is generally incorporated in the valve operating device, and the lash adjuster absorbs the change in the gap between the components of the valve operating device.
このようなラッシュアジャスタとして、上記スイングアーム式動弁装置においては、内周に雌ねじを有するナット部材と、前記雌ねじにねじ係合する雄ねじを外周に有するアジャストスクリュと、そのアジャストスクリュにナット部材から突出する方向の回転力を付与するねじりばねとを有し、前記アジャストスクリュが、カムの回転に応じて揺動するアームの揺動支点にかかる荷重を受けるものが知られている(特許文献1)。
As such a lash adjuster, in the above swing arm type valve gear, a nut member having a female screw on the inner periphery, an adjustment screw having a male screw engaged with the female screw on the outer periphery, and a nut member connected to the adjustment screw. There is known a torsion spring that applies a rotational force in a protruding direction, and the adjustment screw receives a load applied to a swing fulcrum of an arm that swings in accordance with the rotation of a cam (Patent Document 1). ).
また、上記ロッカアーム式動弁装置においては、内周に雌ねじを有するナット部材と、前記雌ねじにねじ係合する雄ねじを外周に有するアジャストスクリュと、そのアジャストスクリュにナット部材から突出する方向の回転力を付与するねじりばねとを有し、前記アジャストスクリュが、カムの回転に応じて揺動するアームと、そのアームで押し下げられるバルブステムとの間にかかる荷重を受けるものが知られている(特許文献1)。
Further, in the rocker arm type valve gear, a nut member having a female screw on the inner periphery, an adjustment screw having a male screw threadedly engaged with the female screw on the outer periphery, and a rotational force in a direction projecting from the nut member to the adjustment screw It is known that the adjustment screw receives a load applied between an arm that swings in response to rotation of a cam and a valve stem that is pushed down by the arm (patent) Reference 1).
また、上記ダイレクト式動弁装置においては、内周に雌ねじを有するナット部材と、前記雌ねじにねじ係合する雄ねじを外周に有するアジャストスクリュと、そのアジャストスクリュにナット部材から突出する方向の回転力を付与するねじりばねとを有し、前記アジャストスクリュが、カムの回転に応じて上下にスライドするリフタボディと、そのリフタボディで押し下げられるバルブステムとの間にかかる荷重を受けるものが知られている(特許文献1)。
Further, in the direct type valve gear, a nut member having an internal thread on the inner periphery, an adjustment screw having an external thread that engages with the internal thread on the outer periphery, and a rotational force in a direction in which the adjustment screw protrudes from the nut member It is known that the adjusting screw receives a load applied between a lifter body that slides up and down in response to rotation of a cam and a valve stem that is pushed down by the lifter body ( Patent Document 1).
これらのラッシュアジャスタは、カムの回転により、アジャストスクリュに押し込み方向の荷重が負荷されたときは、アジャストスクリュがナット部材で受け止められて、アジャストスクリュの軸方向位置が固定される。また、熱膨張などによって動弁装置の構成部材間の相対位置が変化すると、その位置変化に応じて、アジャストスクリュがナット部材内を回転しながら軸方向に移動し、動弁装置の構成部材間の隙間の変化を吸収する。
In these lash adjusters, when a load in the pushing direction is applied to the adjustment screw due to the rotation of the cam, the adjustment screw is received by the nut member, and the axial position of the adjustment screw is fixed. Further, when the relative position between the structural members of the valve operating device changes due to thermal expansion or the like, the adjusting screw moves in the axial direction while rotating in the nut member in accordance with the change in position, and between the structural members of the valve operating device. Absorb changes in the gap.
ところで、これらのラッシュアジャスタは、アジャストスクリュに対する押し込み方向の荷重を解除した状態で振動が加わると、アジャストスクリュが、ねじりばねの力によって回転しながら突出方向に移動し、ナット部材から外れるおそれがある。そのため、エンジンの組立て時やメンテナンス時に、動弁装置からカムシャフトやアームを取り外すと、アジャストスクリュがナット部材から外れることがあった。アジャストスクリュが外れた場合、そのアジャストスクリュがエンジン内に入り込むと、アジャストスクリュを拾い上げにくく、煩雑である。さらに、部品が完全にばらけると再組み立てが煩雑となり、場合によっては紛失する恐れもある。
By the way, these lash adjusters may move in the protruding direction while rotating due to the force of the torsion spring and come off the nut member when vibration is applied with the load in the pushing direction against the adjusting screw being released. . For this reason, when the camshaft or the arm is removed from the valve gear during assembly or maintenance of the engine, the adjustment screw may come off from the nut member. When the adjustment screw comes off, if the adjustment screw enters the engine, it is difficult to pick up the adjustment screw, which is complicated. Further, if the parts are completely separated, reassembly becomes complicated and may be lost in some cases.
この発明が解決しようとする課題は、エンジンの組立て時やメンテナンス時に、アジャストスクリュがナット部材から外れにくいラッシュアジャスタを提供することである。
The problem to be solved by the present invention is to provide a lash adjuster in which an adjusting screw is difficult to come off from a nut member during assembly or maintenance of an engine.
上記の課題を解決するため、内周に雌ねじを有するナット部材と、前記雌ねじにねじ係合する雄ねじを外周に有するアジャストスクリュと、そのアジャストスクリュにナット部材から突出する方向の回転力を付与するねじりばねとを有するラッシュアジャスタにおいて、前記ねじりばねが自由状態(すなわち、アジャストスクリュに付与する回転力がゼロとなる状態)に復元するまで前記アジャストスクリュを回転させたときに前記雄ねじと雌ねじが少なくとも1ピッチ以上の長さでねじ係合するようにした。
In order to solve the above-mentioned problems, a nut member having an internal thread on the inner periphery, an adjustment screw having an external thread that engages with the internal thread on the outer periphery, and a rotational force in a direction protruding from the nut member is applied to the adjustment screw. In a lash adjuster having a torsion spring, when the adjustment screw is rotated until the torsion spring is restored to a free state (that is, a state where the rotational force applied to the adjustment screw becomes zero), the male screw and the female screw are at least Screws were engaged with a length of 1 pitch or more.
この発明は、例えば、次のラッシュアジャスタに適用することができる。
1)前記アジャストスクリュが、カムの回転に応じて揺動するアームの揺動支点にかかる荷重を受けるスイングアーム式動弁装置のラッシュアジャスタ。
2)前記アジャストスクリュが、カムの回転に応じて揺動するアームと、そのアームで押し下げられるバルブステムとの間にかかる荷重を受けるロッカアーム式動弁装置のラッシュアジャスタ。
3)前記アジャストスクリュが、カムの回転に応じて上下にスライドするリフタボディと、そのリフタボディで押し下げられるバルブステムとの間にかかる荷重を受けるダイレクト式動弁装置のラッシュアジャスタ。 The present invention can be applied to, for example, the following lash adjuster.
1) A lash adjuster for a swing arm type valve operating apparatus in which the adjusting screw receives a load applied to a swing fulcrum of an arm that swings in accordance with the rotation of a cam.
2) A lash adjuster of a rocker arm type valve gear that receives a load applied between an arm in which the adjusting screw swings according to rotation of a cam and a valve stem pushed down by the arm.
3) A lash adjuster for a direct type valve operating device in which the adjusting screw receives a load applied between a lifter body that slides up and down according to the rotation of the cam and a valve stem that is pushed down by the lifter body.
1)前記アジャストスクリュが、カムの回転に応じて揺動するアームの揺動支点にかかる荷重を受けるスイングアーム式動弁装置のラッシュアジャスタ。
2)前記アジャストスクリュが、カムの回転に応じて揺動するアームと、そのアームで押し下げられるバルブステムとの間にかかる荷重を受けるロッカアーム式動弁装置のラッシュアジャスタ。
3)前記アジャストスクリュが、カムの回転に応じて上下にスライドするリフタボディと、そのリフタボディで押し下げられるバルブステムとの間にかかる荷重を受けるダイレクト式動弁装置のラッシュアジャスタ。 The present invention can be applied to, for example, the following lash adjuster.
1) A lash adjuster for a swing arm type valve operating apparatus in which the adjusting screw receives a load applied to a swing fulcrum of an arm that swings in accordance with the rotation of a cam.
2) A lash adjuster of a rocker arm type valve gear that receives a load applied between an arm in which the adjusting screw swings according to rotation of a cam and a valve stem pushed down by the arm.
3) A lash adjuster for a direct type valve operating device in which the adjusting screw receives a load applied between a lifter body that slides up and down according to the rotation of the cam and a valve stem that is pushed down by the lifter body.
前記ねじりばねとしては、例えば、ねじりコイルばねが挙げられる。前記雄ねじと雌ねじは、鋸歯ねじ、三角ねじ、台形ねじのいずれを採用してもよい。
The torsion spring includes, for example, a torsion coil spring. The male screw and the female screw may be any of a sawtooth screw, a triangular screw, and a trapezoidal screw.
この発明のラッシュアジャスタは、ねじりばねが自由状態に復元するまでアジャストスクリュを回転させたときにも、アジャストスクリュの雄ねじとナット部材の雌ねじとが少なくとも1ピッチ以上の長さでねじ係合しているので、エンジンの組立て時やメンテナンス時に、アジャストスクリュがナット部材から外れるのを防止することができる。
In the lash adjuster of the present invention, even when the adjustment screw is rotated until the torsion spring is restored to the free state, the male screw of the adjustment screw and the female screw of the nut member are screw-engaged with a length of at least one pitch. Therefore, it is possible to prevent the adjustment screw from being detached from the nut member during assembly or maintenance of the engine.
図1に、この発明の第1実施形態のラッシュアジャスタ1を組み込んだ動弁装置を示す。この動弁装置は、エンジンのシリンダヘッド2の吸気ポート3に設けられたバルブ4と、そのバルブ4に接続されたバルブステム5と、カム6の回転に応じて揺動するアーム7とを有する。
FIG. 1 shows a valve gear incorporating a lash adjuster 1 according to the first embodiment of the present invention. This valve operating apparatus has a valve 4 provided in an intake port 3 of an engine cylinder head 2, a valve stem 5 connected to the valve 4, and an arm 7 that swings in response to rotation of a cam 6. .
バルブステム5は、バルブ4から上方に延び、シリンダヘッド2を摺動可能に貫通している。バルブステム5の上部外周には、環状のスプリングリテーナ8が固定され、スプリングリテーナ8の下面とシリンダヘッド2の上面の間にバルブスプリング9が組み込まれている。バルブスプリング9は、スプリングリテーナ8を介してバルブステム5を上方に付勢し、その付勢力によってバルブ4をバルブシート10に着座させている。
The valve stem 5 extends upward from the valve 4 and slidably penetrates the cylinder head 2. An annular spring retainer 8 is fixed to the upper outer periphery of the valve stem 5, and a valve spring 9 is incorporated between the lower surface of the spring retainer 8 and the upper surface of the cylinder head 2. The valve spring 9 urges the valve stem 5 upward via the spring retainer 8, and the valve 4 is seated on the valve seat 10 by the urging force.
アーム7は、一方の端部がラッシュアジャスタ1で揺動可能に支持され、他方の端部がバルブステム5の上端に接触している。また、アーム7の中央部にはローラ11が取り付けられ、ローラ11は、アーム7の上方に設けられたカム6に接触している。カム6は、エンジンのクランクシャフト(図示せず)に同調して回転するカムシャフト12に一体に形成されており、カムシャフト12が回転すると、ベースサークル6aに対して***したカム山部6bが、ローラ11を介してアーム7を押し下げるようになっている。
The arm 7 has one end supported by the lash adjuster 1 so as to be swingable, and the other end in contact with the upper end of the valve stem 5. A roller 11 is attached to the central portion of the arm 7, and the roller 11 is in contact with a cam 6 provided above the arm 7. The cam 6 is integrally formed with a camshaft 12 that rotates in synchronization with the crankshaft (not shown) of the engine. When the camshaft 12 rotates, a cam crest 6b that is raised with respect to the base circle 6a is formed. The arm 7 is pushed down via the roller 11.
図1、図2に示すように、ラッシュアジャスタ1は、シリンダヘッド2の上面に開口した収容穴13に挿入される筒状のナット部材14と、ナット部材14の内周に形成された雌ねじ15にねじ係合する雄ねじ16を下部外周に有するアジャストスクリュ17と、アジャストスクリュ17に回転力を付与するねじりコイルばね18とを有する。
As shown in FIGS. 1 and 2, the lash adjuster 1 includes a cylindrical nut member 14 that is inserted into a receiving hole 13 that is open on the upper surface of the cylinder head 2, and a female screw 15 that is formed on the inner periphery of the nut member 14. An adjusting screw 17 having a male screw 16 on the outer periphery of the lower portion thereof, and a torsion coil spring 18 for applying a rotational force to the adjusting screw 17.
図2に示すように、ねじりコイルばね18は、その下端が、ナット部材14の底部に形成された貫通孔19に差し込んで回り止めされ、上端が、アジャストスクリュ17に形成された係止孔20に係止しており、そのねじり変形によって、アジャストスクリュ17がナット部材14から突出する方向の回転力をアジャストスクリュ17に付与している。また、ねじりコイルばね18は、自由状態(すなわち、アジャストスクリュ17に付与する回転力がゼロとなる状態)に復元するまでアジャストスクリュ17が回転したときに、雄ねじ16と雌ねじ15が少なくとも1ピッチ以上の長さでねじ係合するように組み込まれている。
As shown in FIG. 2, the lower end of the torsion coil spring 18 is inserted into a through hole 19 formed at the bottom of the nut member 14 and is prevented from rotating, and the upper end is a locking hole 20 formed in the adjustment screw 17. Due to the torsional deformation, the adjusting screw 17 is given a rotational force in the direction in which the adjusting screw 17 protrudes from the nut member 14. Further, when the adjusting screw 17 is rotated until the torsion coil spring 18 is restored to a free state (that is, a state where the rotational force applied to the adjusting screw 17 becomes zero), the male screw 16 and the female screw 15 are at least one pitch or more. It is incorporated so as to engage with a screw with a length of.
雄ねじ16と雌ねじ15は、アジャストスクリュ17をナット部材14に押し込む方向の荷重を負荷したときに圧力を受ける圧力側フランク21のフランク角が、遊び側フランク22のフランク角よりも大きい鋸歯状に形成されている。
The male screw 16 and the female screw 15 are formed in a sawtooth shape in which the flank angle of the pressure-side flank 21 that receives pressure when a load in the direction of pushing the adjusting screw 17 into the nut member 14 is applied is larger than the flank angle of the play-side flank 22. Has been.
収容穴13の内底面には、貫通孔19と連通する排油孔23が形成されている。そのため、ナット部材14の上端面から雄ねじ16と雌ねじ15の隙間を通ってナット部材14内に流れ込んだエンジン油は、貫通孔19と排油孔23とを順に通ってナット部材14から排出される。
An oil drain hole 23 communicating with the through hole 19 is formed on the inner bottom surface of the accommodation hole 13. Therefore, the engine oil that has flowed into the nut member 14 from the upper end surface of the nut member 14 through the gap between the male screw 16 and the female screw 15 is discharged from the nut member 14 through the through hole 19 and the oil drain hole 23 in order. .
アジャストスクリュ17は、図1に示すように、ナット部材14からの突出端24が半球状に形成され、その突出端24が、アーム7の端部下面に形成された凹部25に嵌合しており、カム6の回転に応じて揺動するアーム7の揺動支点にかかる荷重を受けるようになっている。
As shown in FIG. 1, the adjusting screw 17 has a protruding end 24 from the nut member 14 formed in a hemispherical shape, and the protruding end 24 is fitted into a recess 25 formed on the lower surface of the end of the arm 7. Thus, the load applied to the swing fulcrum of the arm 7 that swings according to the rotation of the cam 6 is received.
次に、ラッシュアジャスタ1の動作例を説明する。
Next, an example of operation of the lash adjuster 1 will be described.
エンジンの作動によりカム6が回転して、カム6のカム山部6bがアーム7を押し下げると、バルブ4がバルブシート10から離れて、吸気ポート3を開く。このとき、アジャストスクリュ17に押し込み方向の荷重が負荷されるが、雄ねじ16の圧力側フランク21が雌ねじ15の圧力側フランク21で受け止められて、アジャストスクリュ17の軸方向位置が固定される。
When the cam 6 is rotated by the operation of the engine and the cam crest 6b of the cam 6 pushes down the arm 7, the valve 4 is separated from the valve seat 10 and the intake port 3 is opened. At this time, a load in the pushing direction is applied to the adjustment screw 17, but the pressure side flank 21 of the male screw 16 is received by the pressure side flank 21 of the female screw 15, and the axial position of the adjustment screw 17 is fixed.
更にカム6が回転して、カム山部6bがローラ11の位置を過ぎると、バルブスプリング9の付勢力によってバルブステム5が上昇し、バルブ4がバルブシート10に着座して、吸気ポート3を閉じる。
When the cam 6 further rotates and the cam crest 6b passes the position of the roller 11, the valve stem 5 is raised by the urging force of the valve spring 9, the valve 4 is seated on the valve seat 10, and the intake port 3 is close.
厳密には、カム6のカム山部6bがアーム7を押し下げるときに、雄ねじ16と雌ねじ15の圧力側フランク21,21間に僅かな滑りが生じ、その滑りによってアジャストスクリュ17は押し込み方向に移動するが、カム山部6bがローラ11の位置を過ぎて、押し込み方向の荷重が解除されたときに、アジャストスクリュ17は、ねじりコイルばね18の力によって回転しながら突出方向に移動し、元の位置に戻る。
Strictly speaking, when the cam crest 6b of the cam 6 pushes down the arm 7, a slight slip occurs between the pressure- side flanks 21, 21 of the male screw 16 and the female screw 15, and the adjustment screw 17 moves in the pushing direction due to the slip. However, when the cam crest 6b passes the position of the roller 11 and the load in the pushing direction is released, the adjustment screw 17 moves in the protruding direction while rotating by the force of the torsion coil spring 18, and the original screw Return to position.
エンジン作動中に、シリンダヘッド2、バルブステム5、アーム7など、動弁装置の構成部材間に熱膨張差が生じ、カム6とアーム7の間の距離が大きくなったときは、カム6のカム山部6bがアーム7を押し下げるときのアジャストスクリュ17の押し込み量よりも、更にカム6が回転して押し込み方向の荷重が解除されたときのアジャストスクリュ17の突出量が大きくなる。その結果、カム6が回転するごとに、アジャストスクリュ17が突出方向に徐々に移動するので、カム6のベースサークル6aとローラ11の間に隙間が生じない。
During engine operation, when a difference in thermal expansion occurs between the components of the valve operating device such as the cylinder head 2, the valve stem 5, and the arm 7, and the distance between the cam 6 and the arm 7 increases, The amount of protrusion of the adjusting screw 17 when the cam 6 rotates and the load in the pushing direction is released is larger than the amount of pushing of the adjusting screw 17 when the cam crest 6b pushes down the arm 7. As a result, each time the cam 6 rotates, the adjusting screw 17 gradually moves in the protruding direction, so that no gap is generated between the base circle 6 a of the cam 6 and the roller 11.
反対に、バルブ4とバルブシート10の接触面が摩耗したときは、カム6のベースサークル6aがローラ11の位置にあるときにも、バルブスプリング9の付勢力がアジャストスクリュ17に作用するため、カム6のカム山部6bがアーム7を押し下げるときのアジャストスクリュ17の押し込み量よりも、更にカム6が回転して押し込み方向の荷重が解除されたときのアジャストスクリュ17の突出量が小さくなる。その結果、カム6が回転するごとに、アジャストスクリュ17が押し込み方向に数ミクロンずつ移動し、バルブステム5が上昇するので、バルブ4とバルブシート10の接触面間に隙間が生じない。
On the contrary, when the contact surface of the valve 4 and the valve seat 10 is worn, the biasing force of the valve spring 9 acts on the adjustment screw 17 even when the base circle 6a of the cam 6 is at the position of the roller 11. The amount of protrusion of the adjusting screw 17 when the cam 6 rotates and the load in the pushing direction is released is smaller than the amount of pushing of the adjusting screw 17 when the cam crest 6b of the cam 6 pushes down the arm 7. As a result, every time the cam 6 rotates, the adjusting screw 17 moves by several microns in the pushing direction and the valve stem 5 rises, so that no gap is generated between the contact surfaces of the valve 4 and the valve seat 10.
このラッシュアジャスタ1は、動弁装置からカムシャフト12とアーム7を取り外した状態では、ねじりコイルばね18の力によってアジャストスクリュ17が回転しながら突出方向に移動するが、このとき、ねじりコイルばね18が自由状態に復元するまでアジャストスクリュ17が回転しても、図2に示すように、雄ねじ16と雌ねじ15のねじ係合が保たれる。そのため、エンジンの組立て時やメンテナンス時に、アジャストスクリュ17がナット部材14から外れるのを防止することができる。また、アジャストスクリュ17がナット部材14から外れるのを防止するための部材を設ける必要がないので、組み立てが簡単である。
In a state where the camshaft 12 and the arm 7 are removed from the valve operating device, the lash adjuster 1 moves in the protruding direction while the adjustment screw 17 is rotated by the force of the torsion coil spring 18. At this time, the torsion coil spring 18 is moved. As shown in FIG. 2, the screw engagement between the male screw 16 and the female screw 15 is maintained even if the adjusting screw 17 rotates until the screw is restored to the free state. Therefore, it is possible to prevent the adjustment screw 17 from being detached from the nut member 14 during engine assembly or maintenance. Further, since there is no need to provide a member for preventing the adjustment screw 17 from coming off from the nut member 14, the assembly is simple.
図3に、この発明の第2実施形態のラッシュアジャスタ31を組み込んだ動弁装置を示す。この動弁装置は、エンジンのシリンダヘッド32の吸気ポート33に設けられたバルブ34と、そのバルブ34に接続されたバルブステム35と、カム36の回転に応じて揺動するアーム37とを有する。
FIG. 3 shows a valve gear incorporating a lash adjuster 31 according to a second embodiment of the present invention. This valve operating apparatus has a valve 34 provided in an intake port 33 of a cylinder head 32 of the engine, a valve stem 35 connected to the valve 34, and an arm 37 that swings according to the rotation of a cam 36. .
バルブステム35は、バルブ34から上方に延びており、バルブステム35の上部にはスプリングリテーナ38が固定されている。スプリングリテーナ38は、バルブスプリング39によって上方に付勢され、その付勢力によってバルブ34をバルブシート40に着座させている。
The valve stem 35 extends upward from the valve 34, and a spring retainer 38 is fixed to the upper portion of the valve stem 35. The spring retainer 38 is urged upward by a valve spring 39, and the valve 34 is seated on the valve seat 40 by the urging force.
アーム37は、中央部を支点軸41で揺動可能に支持されている。アーム37の一方の端部には、カム36に接触するローラ42が取り付けられ、アーム37の他方の端部には、ラッシュアジャスタ31が組み込まれている。アーム37の下方に設けられたカム36は、エンジンのクランクシャフト(図示せず)に同調して回転するカムシャフト43に一体に形成されており、カムシャフト43が回転すると、ベースサークル36aに対して***したカム山部36bが、ローラ42を押圧してアーム37を揺動させるようになっている。
The arm 37 is supported at the center by a fulcrum shaft 41 so as to be swingable. A roller 42 that contacts the cam 36 is attached to one end of the arm 37, and a lash adjuster 31 is incorporated into the other end of the arm 37. The cam 36 provided below the arm 37 is integrally formed with a camshaft 43 that rotates in synchronization with a crankshaft (not shown) of the engine. When the camshaft 43 rotates, the cam 36 rotates relative to the base circle 36a. The cam crest portion 36 b that is raised in this manner presses the roller 42 and swings the arm 37.
図3、図4に示すように、ラッシュアジャスタ31は、アーム37の下面に開口した収容穴44に挿入される筒状のナット部材45と、ナット部材45の内周に形成された雌ねじ46にねじ係合する雄ねじ47を外周に有するアジャストスクリュ48と、アジャストスクリュ48に回転力を付与するねじりコイルばね49とを有する。
As shown in FIGS. 3 and 4, the lash adjuster 31 includes a cylindrical nut member 45 inserted into the accommodation hole 44 opened on the lower surface of the arm 37, and a female screw 46 formed on the inner periphery of the nut member 45. An adjustment screw 48 having a male screw 47 that engages with the screw on the outer periphery, and a torsion coil spring 49 that applies a rotational force to the adjustment screw 48 are provided.
図4に示すように、雄ねじ47と雌ねじ46は、上下対称の三角ねじである。ナット部材45は、収容穴44の縁をかしめることによって、アーム37に回り止めされている。
As shown in FIG. 4, the male screw 47 and the female screw 46 are vertically symmetrical triangular screws. The nut member 45 is prevented from rotating around the arm 37 by caulking the edge of the accommodation hole 44.
ねじりコイルばね49は、その上端が、収容穴44の内底面に形成された貫通孔50に差し込んで回り止めされ、下端が、アジャストスクリュ48に形成された係止孔51に係止しており、そのねじり変形によって、ナット部材45から下方に突出する方向の回転力をアジャストスクリュ48に付与している。また、ねじりコイルばね49は、自由状態(すなわち、アジャストスクリュ48に付与する回転力がゼロとなる状態)に復元するまでアジャストスクリュ48が回転したときに、雄ねじ47と雌ねじ46が少なくとも1ピッチ以上の長さでねじ係合するように組み込まれている。
The upper end of the torsion coil spring 49 is inserted into a through hole 50 formed in the inner bottom surface of the accommodation hole 44 and is prevented from rotating, and the lower end is engaged with an engagement hole 51 formed in the adjustment screw 48. Due to the torsional deformation, the adjusting screw 48 is applied with a rotational force in a direction protruding downward from the nut member 45. Further, when the adjusting screw 48 is rotated until the torsion coil spring 49 is restored to a free state (that is, a state where the rotational force applied to the adjusting screw 48 becomes zero), the male screw 47 and the female screw 46 are at least one pitch or more. It is incorporated so as to engage with a screw with a length of.
図3に示すように、アジャストスクリュ48は、ナット部材45からの突出端がバルブステム35の上端に当接し、アーム37とバルブステム35の間にかかる荷重を受けるようになっている。
As shown in FIG. 3, the adjustment screw 48 has a protruding end from the nut member 45 abutting on the upper end of the valve stem 35 and receives a load applied between the arm 37 and the valve stem 35.
このラッシュアジャスタ31は、第1実施形態と同様、カム36のカム山部36bがアーム37の端部を押し上げて、アジャストスクリュ48に押し込み方向の荷重が負荷されると、雄ねじ47が雌ねじ46で受け止められて、ナット部材45に対するアジャストスクリュ48の軸方向位置が固定される。このとき、厳密には、雄ねじ47と雌ねじ46の間に僅かな滑りが生じ、その滑りによってアジャストスクリュ48は押し込み方向に移動するが、更にカム36が回転して押し込み方向の荷重が解除されたときに、アジャストスクリュ48は、ねじりコイルばね49の力によって回転しながら突出方向に移動し、元の位置に戻る。
In the lash adjuster 31, when the cam crest 36 b of the cam 36 pushes up the end of the arm 37 and a load in the pushing direction is applied to the adjustment screw 48, the male screw 47 becomes the female screw 46, as in the first embodiment. The axial position of the adjusting screw 48 relative to the nut member 45 is fixed. Strictly, a slight slip occurs between the male screw 47 and the female screw 46 at this time, and the adjustment screw 48 moves in the pushing direction due to the slip, but the cam 36 further rotates to release the load in the pushing direction. Sometimes, the adjusting screw 48 moves in the protruding direction while rotating by the force of the torsion coil spring 49, and returns to the original position.
このラッシュアジャスタ31は、動弁装置からアーム37を取り外した状態では、ねじりコイルばね49の力によってアジャストスクリュ48が回転しながら突出方向に移動するが、このとき、ねじりコイルばね49が自由状態に復元するまでアジャストスクリュ48が回転しても、図4に示すように、雄ねじ47と雌ねじ46のねじ係合が保たれる。そのため、エンジンの組立て時やメンテナンス時に、アジャストスクリュ48がナット部材45から外れるのを防止することができる。また、アジャストスクリュ48がナット部材45から外れるのを防止するための部材を設ける必要がないので、組み立てが簡単である。
When the arm 37 is removed from the valve gear, the lash adjuster 31 moves in the protruding direction while the adjustment screw 48 is rotated by the force of the torsion coil spring 49. At this time, the torsion coil spring 49 is in a free state. Even if the adjusting screw 48 rotates until it is restored, the screw engagement between the male screw 47 and the female screw 46 is maintained as shown in FIG. Therefore, it is possible to prevent the adjustment screw 48 from being detached from the nut member 45 during engine assembly or maintenance. Further, since there is no need to provide a member for preventing the adjustment screw 48 from coming off the nut member 45, the assembly is simple.
図5に、この発明の第3実施形態のラッシュアジャスタ61を組み込んだ動弁装置を示す。この動弁装置は、シリンダヘッド62の吸気ポート63に設けられたバルブ64と、そのバルブ64に接続されたバルブステム65とを有する。
FIG. 5 shows a valve gear incorporating a lash adjuster 61 according to a third embodiment of the present invention. This valve operating apparatus has a valve 64 provided in the intake port 63 of the cylinder head 62 and a valve stem 65 connected to the valve 64.
バルブステム65は、バルブ64から上方に延びており、バルブステム65の上部外周には環状のスプリングリテーナ66が固定されている。スプリングリテーナ66は、バルブスプリング67によって上方に付勢され、その付勢力によってバルブ64をバルブシート68に着座させている。
The valve stem 65 extends upward from the valve 64, and an annular spring retainer 66 is fixed to the upper outer periphery of the valve stem 65. The spring retainer 66 is urged upward by a valve spring 67, and the valve 64 is seated on the valve seat 68 by the urging force.
図5、図6に示すように、ラッシュアジャスタ61は、シリンダヘッド62に形成されたガイド孔69に上下にスライド可能に挿入されるリフタボディ70と、リフタボディ70と一体に上下動するナット部材71と、ナット部材71の内周に形成された雌ねじ72にねじ係合する雄ねじ73を外周に有するアジャストスクリュ74と、アジャストスクリュ74に回転力を付与するねじりコイルばね75とを有する。
As shown in FIGS. 5 and 6, the lash adjuster 61 includes a lifter body 70 that is slidably inserted into a guide hole 69 formed in the cylinder head 62, and a nut member 71 that moves up and down integrally with the lifter body 70. And an adjusting screw 74 having a male screw 73 engaged with a female screw 72 formed on the inner periphery of the nut member 71 on the outer periphery, and a torsion coil spring 75 for applying a rotational force to the adjusting screw 74.
リフタボディ70は、筒部76と、筒部76の上端に設けられた端板77とからなり、端板77の上面にカム78が接触している。カム78は、エンジンのクランクシャフト(図示せず)に同調して回転するカムシャフト79に一体に形成され、カムシャフト79が回転すると、ベースサークル78aに対して***したカム山部78bがリフタボディ70を押し下げるようになっている。ナット部材71は、止め輪80でリフタボディ70に固定されている。
The lifter body 70 includes a cylindrical portion 76 and an end plate 77 provided at the upper end of the cylindrical portion 76, and a cam 78 is in contact with the upper surface of the end plate 77. The cam 78 is integrally formed with a camshaft 79 that rotates in synchronization with the crankshaft (not shown) of the engine. When the camshaft 79 rotates, a cam crest 78b raised with respect to the base circle 78a is formed on the lifter body 70. Is to be pushed down. The nut member 71 is fixed to the lifter body 70 with a retaining ring 80.
図6に示すように、雄ねじ73と雌ねじ72は、上下対称の台形ねじである。ねじりコイルばね75は、その上端が、ナット部材71の上面に形成された係止溝81に差し込んで回り止めされ、下端が、アジャストスクリュ74に形成された係止孔82に係止しており、そのねじり変形によって、ナット部材71から下方に突出する方向の回転力をアジャストスクリュ74に付与している。また、ねじりコイルばね75は、自由状態(すなわち、アジャストスクリュ74に付与する回転力がゼロとなる状態)に復元するまでアジャストスクリュ74が回転したときに、雄ねじ73と雌ねじ72が少なくとも1ピッチ以上の長さでねじ係合するように組み込まれている。
As shown in FIG. 6, the male screw 73 and the female screw 72 are vertically symmetrical trapezoidal screws. The upper end of the torsion coil spring 75 is inserted into a locking groove 81 formed on the upper surface of the nut member 71 and is prevented from rotating, and the lower end is locked in a locking hole 82 formed in the adjusting screw 74. Due to the torsional deformation, a rotational force in a direction protruding downward from the nut member 71 is applied to the adjusting screw 74. Further, when the adjusting screw 74 rotates until the torsion coil spring 75 is restored to a free state (that is, a state where the rotational force applied to the adjusting screw 74 becomes zero), the male screw 73 and the female screw 72 are at least one pitch or more. It is incorporated so as to engage with a screw with a length of.
図5に示すように、アジャストスクリュ74は、ナット部材71からの突出端が、スペーサ83を介してバルブステム65の上端に接触しており、リフタボディ70とバルブステム65の間にかかる荷重を受けるようになっている。
As shown in FIG. 5, the adjustment screw 74 has a protruding end from the nut member 71 in contact with the upper end of the valve stem 65 via the spacer 83, and receives a load applied between the lifter body 70 and the valve stem 65. It is like that.
このラッシュアジャスタ61は、第1実施形態と同様、カム78のカム山部78bがリフタボディ70を押し下げて、アジャストスクリュ74に押し込み方向の荷重が負荷されると、雄ねじ73が雌ねじ72で受け止められて、ナット部材71に対するアジャストスクリュ74の軸方向位置が固定される。このとき、厳密には、雄ねじ73と雌ねじ72の間に僅かな滑りが生じ、その滑りによってアジャストスクリュ74は押し込み方向に移動するが、更にカム78が回転して押し込み方向の荷重が解除されたときに、アジャストスクリュ74は、ねじりコイルばね75の力によって回転しながら突出方向に移動し、元の位置に戻る。
In the lash adjuster 61, when the cam crest 78b of the cam 78 pushes down the lifter body 70 and a load in the pushing direction is applied to the adjusting screw 74, the male screw 73 is received by the female screw 72 as in the first embodiment. The axial position of the adjusting screw 74 with respect to the nut member 71 is fixed. Strictly, at this time, a slight slip occurs between the male screw 73 and the female screw 72, and the adjustment screw 74 moves in the pushing direction due to the slip, but the cam 78 further rotates to release the load in the pushing direction. Sometimes, the adjusting screw 74 moves in the protruding direction while rotating by the force of the torsion coil spring 75, and returns to the original position.
このラッシュアジャスタ61は、動弁装置からリフタボディ70を取り外した状態では、ねじりコイルばね75の力によってアジャストスクリュ74が回転しながら突出方向に移動するが、このとき、ねじりコイルばね75が自由状態に復元するまでアジャストスクリュ74が回転しても、図6に示すように、雄ねじ73と雌ねじ72のねじ係合が保たれる。そのため、エンジンの組立て時やメンテナンス時に、アジャストスクリュ74がナット部材71から外れるのを防止することができる。また、アジャストスクリュ74がナット部材71から外れるのを防止するための部材を設ける必要がないので、組み立てが簡単である。
When the lifter body 70 is removed from the valve operating device, the lash adjuster 61 moves in the protruding direction while the adjustment screw 74 is rotated by the force of the torsion coil spring 75. At this time, the torsion coil spring 75 is in a free state. Even if the adjusting screw 74 rotates until it is restored, the screw engagement between the male screw 73 and the female screw 72 is maintained as shown in FIG. Therefore, the adjustment screw 74 can be prevented from being detached from the nut member 71 during engine assembly or maintenance. Further, since there is no need to provide a member for preventing the adjustment screw 74 from coming off the nut member 71, the assembly is simple.
1 ラッシュアジャスタ
6 カム
7 アーム
14 ナット部材
15 雌ねじ
16 雄ねじ
17 アジャストスクリュ
18 ねじりコイルばね
31 ラッシュアジャスタ
35 バルブステム
36 カム
37 アーム
45 ナット部材
46 雌ねじ
47 雄ねじ
48 アジャストスクリュ
49 ねじりコイルばね
61 ラッシュアジャスタ
65 バルブステム
70 リフタボディ
71 ナット部材
72 雌ねじ
73 雄ねじ
74 アジャストスクリュ
75 ねじりコイルばね
78 カム 1Rush Adjuster 6 Cam 7 Arm 14 Nut Member 15 Female Thread 16 Male Thread 17 Adjust Screw 18 Torsion Coil Spring 31 Rush Adjuster 35 Valve Stem 36 Cam 37 Arm 45 Nut Member 46 Female Thread 47 Male Thread 48 Adjust Screw 49 Torsion Coil Spring 61 Rush Adjuster 65 Valve Stem 70 Lifter body 71 Nut member 72 Female screw 73 Male screw 74 Adjusting screw 75 Torsion coil spring 78 Cam
6 カム
7 アーム
14 ナット部材
15 雌ねじ
16 雄ねじ
17 アジャストスクリュ
18 ねじりコイルばね
31 ラッシュアジャスタ
35 バルブステム
36 カム
37 アーム
45 ナット部材
46 雌ねじ
47 雄ねじ
48 アジャストスクリュ
49 ねじりコイルばね
61 ラッシュアジャスタ
65 バルブステム
70 リフタボディ
71 ナット部材
72 雌ねじ
73 雄ねじ
74 アジャストスクリュ
75 ねじりコイルばね
78 カム 1
Claims (8)
- 内周に雌ねじ(15)を有するナット部材(14)と、前記雌ねじ(15)にねじ係合する雄ねじ(16)を外周に有するアジャストスクリュ(17)と、そのアジャストスクリュ(17)にナット部材(14)から突出する方向の回転力を付与するねじりばね(18)とを有するラッシュアジャスタにおいて、
前記ねじりばね(18)が自由状態に復元するまで前記アジャストスクリュ(17)を回転させたときに前記雄ねじ(16)と雌ねじ(15)が少なくとも1ピッチ以上の長さでねじ係合するようにしたことを特徴とするラッシュアジャスタ。 A nut member (14) having a female screw (15) on the inner periphery, an adjustment screw (17) having a male screw (16) screw-engaged with the female screw (15) on the outer periphery, and a nut member on the adjustment screw (17) A lash adjuster having a torsion spring (18) for applying a rotational force in a direction protruding from (14);
When the adjusting screw (17) is rotated until the torsion spring (18) is restored to a free state, the male screw (16) and the female screw (15) are screw-engaged with a length of at least one pitch. Rush adjuster characterized by that. - 前記アジャストスクリュ(17)が、カム(6)の回転に応じて揺動するアーム(7)の揺動支点にかかる荷重を受ける請求項1に記載のラッシュアジャスタ。 The lash adjuster according to claim 1, wherein the adjustment screw (17) receives a load applied to a swing fulcrum of an arm (7) that swings according to rotation of the cam (6).
- 前記アジャストスクリュ(48)が、カム(36)の回転に応じて揺動するアーム(37)と、そのアーム(37)で押し下げられるバルブステム(35)との間にかかる荷重を受ける請求項1に記載のラッシュアジャスタ。 The adjustment screw (48) receives a load applied between an arm (37) that swings according to rotation of the cam (36) and a valve stem (35) that is pushed down by the arm (37). Rush adjuster described in 1.
- 前記アジャストスクリュ(74)が、カム(78)の回転に応じて上下にスライドするリフタボディ(70)と、そのリフタボディ(70)で押し下げられるバルブステム(65)との間にかかる荷重を受ける請求項1に記載のラッシュアジャスタ。 The adjustment screw (74) receives a load applied between a lifter body (70) that slides up and down according to rotation of a cam (78) and a valve stem (65) pushed down by the lifter body (70). The lash adjuster according to 1.
- 前記ねじりばね(18)が、ねじりコイルばねである請求項1から4のいずれかに記載のラッシュアジャスタ。 The lash adjuster according to any one of claims 1 to 4, wherein the torsion spring (18) is a torsion coil spring.
- 前記雄ねじ(16)と雌ねじ(15)が、鋸歯ねじである請求項1から5のいずれかに記載のラッシュアジャスタ。 The lash adjuster according to any one of claims 1 to 5, wherein the male screw (16) and the female screw (15) are sawtooth screws.
- 前記雄ねじ(47)と雌ねじ(46)が、三角ねじである請求項1から5のいずれかに記載のラッシュアジャスタ。 The lash adjuster according to any one of claims 1 to 5, wherein the male screw (47) and the female screw (46) are triangular screws.
- 前記雄ねじ(73)と雌ねじ(72)が、台形ねじである請求項1から5のいずれかに記載のラッシュアジャスタ。 The lash adjuster according to any one of claims 1 to 5, wherein the male screw (73) and the female screw (72) are trapezoidal screws.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
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JP2008-180070 | 2008-07-10 | ||
JP2008180070A JP2010019156A (en) | 2008-07-10 | 2008-07-10 | Lash adjuster |
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WO2010004909A1 true WO2010004909A1 (en) | 2010-01-14 |
Family
ID=41507025
Family Applications (1)
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PCT/JP2009/061931 WO2010004909A1 (en) | 2008-07-10 | 2009-06-30 | Lash adjuster |
Country Status (2)
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JP (1) | JP2010019156A (en) |
WO (1) | WO2010004909A1 (en) |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2003521624A (en) * | 2000-02-02 | 2003-07-15 | マッケクニー スペシャリスト プロダクツ リミテッド | Automatic valve clearance adjustment device |
JP2006336584A (en) * | 2005-06-03 | 2006-12-14 | Ntn Corp | Direct type valve system |
JP2008002444A (en) * | 2006-06-26 | 2008-01-10 | Ntn Corp | Arm type valve gear |
JP2009108801A (en) * | 2007-10-31 | 2009-05-21 | Ntn Corp | Rush adjuster |
-
2008
- 2008-07-10 JP JP2008180070A patent/JP2010019156A/en not_active Withdrawn
-
2009
- 2009-06-30 WO PCT/JP2009/061931 patent/WO2010004909A1/en active Application Filing
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2003521624A (en) * | 2000-02-02 | 2003-07-15 | マッケクニー スペシャリスト プロダクツ リミテッド | Automatic valve clearance adjustment device |
JP2006336584A (en) * | 2005-06-03 | 2006-12-14 | Ntn Corp | Direct type valve system |
JP2008002444A (en) * | 2006-06-26 | 2008-01-10 | Ntn Corp | Arm type valve gear |
JP2009108801A (en) * | 2007-10-31 | 2009-05-21 | Ntn Corp | Rush adjuster |
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JP2010019156A (en) | 2010-01-28 |
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