US20110017161A1 - Lash adjuster - Google Patents
Lash adjuster Download PDFInfo
- Publication number
- US20110017161A1 US20110017161A1 US12/922,695 US92269509A US2011017161A1 US 20110017161 A1 US20110017161 A1 US 20110017161A1 US 92269509 A US92269509 A US 92269509A US 2011017161 A1 US2011017161 A1 US 2011017161A1
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- US
- United States
- Prior art keywords
- adjusting screw
- lash adjuster
- nut member
- initial setting
- cut
- 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
- F01L1/20—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
- F01L1/18—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
- F01L2305/00—Valve arrangements comprising rollers
Definitions
- This invention relates to a lash adjuster mounted in a valve gear for an engine.
- Valve gears for moving valves provided at engine intake ports or exhaust ports include ones having an arm pivotable about one end thereof and adapted to be pressed down by a cam at its mid-portion, thereby pressing down a valve stem at its other end (swing arm type valve gear), and ones having an arm pivotable its mid-portion and adapted to be pushed up by a cam at one end thereof, thereby pressing down a valve stem at its other end (rocker arm type valve gear).
- valve gears ordinarily include a lash adjuster to absorb changes in gaps between component parts of the valve gear.
- a typical lash adjuster for use in a swing arm type valve gear comprises a nut member inserted in a receiving hole formed in the top surface of the cylinder head, an adjusting screw having an external thread on its outer periphery which is in threaded engagement with an internal thread formed on the inner periphery of the nut member, and a return spring biasing the adjusting screw in the direction to protrude upwardly from the nut member, thereby pivotally supporting the arm of the valve gear with the adjusting screw (Patent document 1).
- a typical lash adjuster for use in a rocker arm type valve gear comprises a nut member inserted in a receiving hole formed in the bottom surface of the arm, which pivots as the cam rotates, an adjusting screw having an external thread on its outer periphery which is in threaded engagement with an internal thread formed on the inner periphery of the nut member, and a return spring biasing the adjusting screw in the direction to protrude downwardly from the nut member, thereby pressing the valve stem of the valve gear (Patent document 2).
- a lash adjuster in which, in order fix the adjusting screw so as not to protrude from the nut member (initial set position), the adjusting screw is fixed in position by wax contained in the nut member (Patent document 3).
- An object of the present invention is to provide a lash adjuster of which the lash adjuster can be repeatedly fixed in the initial set position.
- an initial setting member is detachably disposed between the adjusting screw and the nut member so that the adjusting screw is fixed to the nut member due to frictional forces between the initial setting member and the adjusting screw and between the initial setting member and the nut member.
- This lash adjuster may have e.g. one of the following structures:
- the initial setting member may have e.g. one of the following structures:
- a jig-inserting hole ( 30 ) may be formed in the operating tab portion of the initial setting member of the structure 1b) or 1c). With this arrangement, it is possible to pull out the initial setting member by inserting a jig in the jig-inserting hole, thus making it easier to release the initial set position.
- the adjusting screw may comprise a pivot member axially slidably inserted in the nut member, an externally threaded member supporting the end of the pivot member inserted in the nut member and having the external thread on an outer periphery thereof, and an elastic member disposed between the pivot member and the externally threaded member.
- the cut-out may be formed on the outer periphery of the pivot member.
- the cut-out may be a D-cut portion or comprise two chamfers formed on the outer periphery of the adjusting screw.
- cut-out is formed so as to separate the external thread on the adjusting screw into a plurality of sections, a plurality of such cut-outs are formed so as be circumferentially equidistantly spaced from each other.
- the initial setting member may further comprise a pull-out portion which can be engaged by a finger, whereby the initial setting member can be pulled out of the insertion opening with the finger. This makes it easier to release the initial set position.
- the initial setting member is preferably made of rubber or resin because such an initial setting member is lighter in weight than one made of a metal such as iron.
- the present invention is applicable e.g. to the following lash adjusters:
- the adjusting screw since the adjusting screw is fixed in position using the detachable initial setting member, the adjusting screw can be repeatedly set in the initial set position.
- initial setting is complete simply by threading the adjusting screw all the way and it is never necessary to finely adjust the turning amount of the adjusting screw.
- initial setting is easy.
- FIG. 1 is a front view of a valve gear including a lash adjuster according to a first embodiment of the present invention.
- FIG. 2 is an enlarged sectional view of the lash adjuster shown in FIG. 1 , showing the state before the lash adjuster is fixed in an initial set position.
- FIG. 3 is an enlarged sectional view taken along line III-III of FIG. 2 .
- FIG. 4 is an enlarged sectional view taken along line IV-IV of FIG. 2 .
- FIG. 5 is an enlarged sectional view of the lash adjuster shown in FIG. 2 , showing the initial set position of the adjusting screw.
- FIG. 6 is a front view of the lash adjuster when the initial set position of the adjusting screw has been released.
- FIG. 7 is a enlarged perspective view of a modification of an initial setting member shown in FIGS. 2 to 4 .
- FIG. 8 shows how the adjusting screw is fixed in the initial set position by the initial setting member shown in FIG. 7 .
- FIG. 9 is an enlarged perspective view of another modification of the initial setting member shown in FIGS. 2 to 4 .
- FIG. 10 shows how the adjusting screw is fixed in the initial set position by the initial setting member shown in FIG. 9 .
- FIG. 11 is a front view of a valve gear including a lash adjuster according to a second embodiment of the present invention.
- FIG. 12 is an enlarged sectional view of the lash adjuster of FIG. 11 and its surroundings.
- FIG. 13 is a front view of a valve gear including a lash adjuster according to a third embodiment of the present invention.
- FIG. 14 is an enlarged sectional view of the lash adjuster shown in FIG. 13 .
- FIG. 15 is a sectional taken along line XV-XV of FIG. 14 .
- FIG. 16 is an enlarged sectional view of the lash adjuster showing how an elastic portion of an initial setting member shown in FIG. 14 is inserted in an insertion opening.
- FIG. 17 is an enlarged sectional view of the lash adjuster showing the state in which the elastic portion of the initial setting member shown in FIG. 14 has been pulled out of the insertion opening.
- FIG. 18 is a perspective view of the initial setting member shown in FIG. 14 .
- FIG. 19 is a sectional view of a modification of the lash adjuster of FIG. 14 .
- FIG. 20 is a sectional view taken along line XX-XX of FIG. 19 .
- FIG. 21 is an enlarged sectional view of the lash adjuster showing the state in which a elastic portion of an initial setting member shown in FIG. 19 has been pulled out of an insertion opening.
- FIG. 22 is a front view of a valve gear including a lash adjuster according to a fourth embodiment of the present invention.
- FIG. 23 is an enlarged sectional view of the lash adjuster shown in FIG. 22 .
- FIG. 24 is a sectional view taken along line XXIV-XXIV of FIG. 23 .
- FIG. 25 is an enlarged sectional view of a lash adjuster according to a fifth embodiment of the present invention.
- FIG. 26 is a sectional view taken along line XXVI-XXVI of FIG. 25 .
- FIG. 1 shows a valve gear including the lash adjuster 1 according to the first embodiment of the present invention.
- This valve gear includes a valve 4 provided at an intake port 3 of a cylinder head 2 of an engine, a valve stem 5 connected to the valve 4 , and a arm 7 pivotable as a cam 6 rotates.
- the valve stem 5 extends upwardly from the valve 4 and slidably through the cylinder head 2 .
- An annular spring retainer 8 is fixed to the outer periphery of the valve stem 5 at its upper portion.
- a valve spring 9 is mounted between the bottom surface of the spring retainer 8 and the top surface of the cylinder head 2 . The valve spring 9 biases the valve stem 5 upwardly through the spring retainer 8 , thereby seating the valve 4 on a valve seat 10 .
- the arm 7 has one end thereof pivotally supported by the lash adjuster 1 and the other end kept in contact with the top end of the valve stem 5 .
- the arm 7 carries a roller 11 which is pressed by the cam 6 , which is provided over the roller 11 .
- the cam 6 is integrally formed on a camshaft 12 which rotates in unison with the engine crankshaft (not shown).
- the lash adjuster 1 comprises a cylindrical nut member 14 received in a receiving hole 13 formed in the top surface of the cylinder head 2 , an adjusting screw 17 having an external thread 16 on its outer periphery at its lower portion which is in threaded engagement with an internal thread 15 formed on the inner periphery of the nut member 14 , and a return spring 19 mounted between the adjusting screw 17 and a bottom portion 18 of the nut member 14 .
- the external thread 16 and the internal thread 15 each have a pressure flank 20 that receives pressure when a load is applied that tends to push the adjusting screw 17 into the nut member 14 .
- the pressure flank 20 has a flank angle larger than the clearance flank 21 so that the threads 16 and 15 have a serration-shaped section.
- the pressure flanks 20 of the external thread 16 and the internal thread 15 may have a flank angle of 75°, while their clearance flanks 21 may have a flank angle of 15°.
- the return spring 19 is a compression spring and is mounted in the nut member 15 while being axially compressed.
- the return spring 19 has its bottom end supported on the bottom portion 18 of the nut member 14 , and applies, at its top end, an axial force to the adjusting screw 17 through a spring seat 22 that tends to push the adjusting screw 17 out of the nut member 14 , thereby biasing the adjusting screw 17 in the direction to protrude upwardly from the nut member 14 .
- the adjusting screw 17 has a head 23 having an outer diameter larger than the inner diameter of the nut member 14 .
- the head 23 is engaged in a recess 24 formed in the bottom surface of the art 7 at its end portion, thereby supporting the arm 7 .
- the head 23 has a hemispherical contact surface that is in contact with the recess 24 .
- the arm 7 is pivotable due to sliding between the head 23 and the recess 24 .
- an initial setting member 25 formed by bending a metal wire is inserted between the bottom end surface of the head 23 and the top end surface of the nut member 14 .
- the initial setting member 25 comprises arm portions 26 diametrically opposed to each other with the adjusting screw 17 disposed therebetween, and an operating tab portion 27 connecting together ends of the respective arm portions 26 .
- the arm portions 26 each have a corrugated portion disposed between the bottom end surface of the head 23 and the top end surface of the nut member 14 .
- the corrugated portions are formed by bending the wire in a corrugated shape so as to be axially elastically deformable.
- the lash adjustor 1 is assembled into the valve gear e.g. in the following manner.
- the lash adjuster 1 is inserted into the receiving hole 13 of the cylinder head 2 , and the arm 7 and the camshaft 12 are mounted in position.
- the initial setting member 25 is pulled out from between the head 23 of the adjusting screw 17 and the nut member 14 , thus releasing the initial set position.
- the adjusting screw 17 thus protrudes while rotating under the biasing force of the return spring 19 , thus pushing up the end of the arm 7 until the roller 11 contacts the cam 6 .
- valve stem 5 rises under the biasing force of the valve spring 9 , thereby seating the valve 4 against the valve seat 10 , closing the intake port 3 .
- the adjusting screw 17 protrudes by a larger amount when the cam 6 further rotate after the cam lobe 6 a of the cam 6 presses down the arm 7 until the load is removed, than the amount by which the adjusting screw 17 is pushed in when the arm 7 is pressed down by the cam lobe 6 a of the cam 6 .
- the adjusting screw 17 protrudes gradually, thus preventing any gap between the base circle 6 b of the cam 6 and the roller 11 .
- the biasing force of the valve spring 9 keeps acting on the adjusting screw 17 even while the base circle 6 b of the cam 6 faces the roller 11 .
- the adjusting screw 17 protrudes by a smaller amount when the cam 6 further rotate after the cam lobe 6 a of the cam 6 presses down the arm 7 until the load is removed, than the amount by which the adjusting screw 17 is pushed in when the arm 7 is pressed down by the cam lobe 6 a of the cam 6 .
- the adjusting screw 17 is pushed in gradually, allowing the valve stem 5 to rise. This prevents any gap between the contact surfaces of the valve 4 and the valve seat 10 .
- the adjusting screw 17 protrudes from the nut member 14 under the biasing force of the return spring 19 .
- the adjusting screw 17 can be again set in the initial set position.
- the adjusting screw 17 can be fixed in position using the detachably inserted initial setting member 25 , the adjusting screw 17 can be repeatedly set in the initial set position.
- the initial setting member to be disposed between the head 23 of the adjusting screw 17 and the nut member 14 is the initial setting member 25 formed by bending a metal wire material.
- an initial setting member 28 as shown in FIGS. 7 and 8 may be used, which is formed by pressing a metal sheet material.
- the initial setting member 28 comprises two diametrically opposed arm portions 29 , and an operating tab portion 30 connecting together two respective ends of the arm portions 29 .
- the arm portions 29 each have a corrugated portion disposed between the bottom end surface of the head 23 and the top end surface of the nut member 14 .
- the corrugated portions are formed by bending the sheet material in a corrugated shape so as to be axially elastically deformable.
- the operating tab portion 30 is formed with a vertically extending jig-inserting through hole 31 .
- the initial setting member 28 can be pulled out by inserting a jig (not shown) into the jig-inserting hole 31 .
- an initial setting member 32 shown in FIGS. 9 and 10 may be used, which is formed by injection-molding an elastic resin.
- the initial setting member 32 comprises two diametrically opposed arm portions 33 , and an operating tab portion 34 connecting together two respective ends of the arm portions 33 .
- the operating tab portion 34 is formed with a vertically extending jig-inserting through hole 35 .
- the initial setting member 32 can be pulled out by inserting a jig into the jig-inserting hole 35 .
- FIG. 11 shows a valve gear to which the lash adjuster 41 of the second embodiment according to this invention is mounted.
- This valve gear includes a valve 44 provided at an intake port 43 of a cylinder head 42 of an engine, a valve stem 45 connected to the valve 44 , and an arm 47 that pivots as a cam 46 rotates.
- valve stem 45 extends upwardly from the valve 44 .
- a spring retainer 48 is fixed to the upper portion of the valve stem 45 .
- a valve spring 49 biases the spring retainer 48 , thereby seating the valve 44 against a valve seat 50 .
- the arm 47 has its central portion pivotally supported by a pivot shaft 51 , and carries at one end thereof a roller 52 that is in contact with the cam 46 .
- the lash adjuster 41 is mounted to the other end of the arm 47 .
- the cam 46 which is provided under the arm 47 , rotates together with the engine crankshaft (not shown), thereby pivoting the arm 47 by pressing the roller 52 with its cam lobe 46 b, which protrudes from its base circle 46 a.
- the lash adjuster 41 comprises a tubular nut member 54 inserted in a mounting hole 53 formed in the bottom surface of the arm 47 , an adjusting screw 57 having an external thread 56 on its outer periphery at its upper portion which is in threaded engagement with an internal thread 55 formed on the inner periphery of the nut member 54 , and a return spring 59 mounted between the adjusting screw 57 and the inner bottom surface 58 of the mounting hole 53 .
- the external thread 56 and the internal thread 55 each have a pressure flank 60 that receives pressure when a load is applied that tends to push the adjusting screw 57 into the nut member 54 .
- the pressure flank 60 has a flank angle larger than the clearance flank 61 so that the threads 56 and 55 have a serration-shaped section.
- the return spring 59 is a compression coil spring having its top end supported by the inner bottom surface 58 of the mounting hole 53 and applies, at its bottom end, an axial force to the adjusting screw 57 through a spring seat 62 that tends to push the adjusting screw 57 out of the nut member 54 , thereby biasing the adjusting screw 57 in the direction to protrude downwardly from the nut member 54 .
- the adjusting screw 57 has a head 63 having an outer diameter larger than the inner diameter of the nut member 54 .
- the head 63 presses the top end of the valve stem 45 .
- the same initial setting member 25 as used in the first embodiment is inserted between the top end surface of the head 63 and the bottom end surface of the nut member 54 .
- the initial setting member 25 comprises the diametrically opposed arm portions 26 and the operating tab 27 connecting together two respective ends of the arm portions 26 .
- the adjusting screw 57 can be fixed in position using the detachably inserted initial setting member 25 , the adjusting screw 57 can be repeatedly set in the initial set position. Since initial setting is complete simply by threading the adjusting screw 57 into the nut member 54 , initial setting is easy. Also, since it is not necessary to form through holes for inserting a set pin in the adjusting screw 57 and the nut member 54 , its manufacturing cost is low.
- FIG. 13 shows the lash adjuster 71 of the third embodiment. Elements corresponding to those of the first embodiment are denoted by identical numerals and their description is omitted.
- the adjusting screw 17 has a hemispherical protruding end 72 protruding from the nut member 14 .
- the protruding end 72 is fitted in a recess 24 formed in the bottom surface of the arm 7 and supports the arm 7 .
- the arm 7 pivotable as the protruding end 72 slides in the recess 24 .
- an axial groove 73 is formed in the outer periphery of the adjusting screw 17 to extend across the external thread 16 from its top to bottom ends.
- the axial groove 73 thus separates the external thread 16 into a plurality of sections.
- the axial groove 73 has a U-shaped section, and defines an insertion opening 74 between the adjusting screw 17 and the nut member 14 .
- An initial setting member 75 is detachably inserted in the insertion opening 74 .
- the initial setting member 75 comprises an elastic portion 76 inserted in the insertion opening 74 , a ring-shaped pull-out portion 77 , and a connecting portion 78 connecting the pull-out portion 77 to the elastic portion 76 .
- the initial setting member 75 is integrally formed from resin or rubber.
- the elastic portion 76 is a bifurcated member having arms extending in the direction opposite to the direction in which the elastic portion 76 is inserted.
- the elastic portion 76 is thus elastically compressed between the inner surface of the axial groove 73 and the pressure flank 20 of the internal thread, thereby producing elastic restoring force, which in turn produces frictional forces between the elastic portion 76 and the adjusting screw 17 and between the elastic portion 76 and the nut member 14 .
- These frictional forces prevent rotation of the adjusting screw 17 , thus keeping the adjusting screw 17 from protruding from the nut member 14 .
- the elastic portion 76 has a stopper 79 adapted to abut the top end of the nut member 14 when the elastic portion 76 is inserted into the insertion opening 74 .
- a through hole 80 is formed in the bottom 18 of the nut member 14 that extends vertically through the bottom 18 .
- an oil discharge hole 81 is formed in the inner bottom surface of the mounting hole 13 which communicates with the through hole 80 .
- the lash adjuster 71 is mounted to the valve gear e.g. as follows.
- the adjusting screw 17 is fixed in the initial set position by inserting the initial setting member 75 in the insertion opening 74 .
- the lash adjuster 71 is inserted into the mounting hole 13 , and the arm 7 and the camshaft 12 are mounted in position.
- the initial setting member 75 is pulled out of the insertion opening 74 by engaging a finger or a tool with the pull-out portion 77 .
- this lash adjuster 71 it is possible to fix the adjusting screw 75 in the initial set position at any desired height by screwing the adjusting screw 17 to the desired height, and then inserting the initial setting member 75 into the insertion opening 74 .
- the adjusting screw 17 can be fixed in the initial set position at any desired height according to the kind of the valve lifter used.
- the initial setting member 75 is made of resin or rubber, the initial setting member 75 is lighter in weight than a similar initial setting member made of a metal such as iron.
- the initial setting member 75 is preferably made of resin because it is more easily recyclable.
- the elastic portion 76 of the initial set member 75 is bifurcated. But as shown in FIGS. 19 to 21 , the elastic portion 76 may be spherically shaped. In FIGS. 19 to 21 , the spherical elastic portion 76 is sized such that it is elastically compressed when inserted into the insertion opening 74 .
- FIG. 15 only one axial groove 73 may be formed. But as shown in FIG. 20 , a plurality of circumferentially equidistantly spaced axial grooves 73 may be formed. With this arrangement, since the external thread 16 and the internal thread 15 axially symmetrically contact each other, the adjusting screw 17 is less likely to incline while the engine is running. Also, if the adjusting screw 17 is formed by forging, forging can be done with higher accuracy.
- the axial groove 73 is formed in the outer periphery of the adjusting screw 17 .
- such an axial groove may be formed in the inner periphery of the nut member 14 instead of in the outer periphery of the adjusting screw 17 .
- such axial grooves may be formed both in the outer periphery of the adjusting screw 17 and in the inner periphery of the nut member 14 .
- the cut-out defining the insertion opening 74 is the axial groove 73 .
- the insertion opening may be defined by a D-cut portion or two chamfers formed on the outer periphery of the adjusting screw 17 .
- the D-cut portion is a cut-out on the outer surface of the adjusting screw 17 extending along a plane parallel to a plane including the axis of the adjusting screw 17 .
- the two chamfers are two flat surfaces formed by cutting out the outer periphery of the adjusting screw 17 so as to extend parallel to a plane including the axis of the adjusting screw 17 .
- a compression coil spring is used as the return spring 19 for biasing the adjusting screw 17 .
- a torsion coil spring may be used instead of a compression coil spring.
- the external thread 16 and the internal thread 15 may be trapezoidal threads or triangular threads.
- FIGS. 22 and 24 show the lash adjuster 91 of the fourth embodiment according to this invention. Elements corresponding to those of the second embodiment are denoted by identical numerals and their description is omitted.
- the return spring 59 is a torsion coil spring having its top end engaged in a through hole 92 formed in the inner bottom surface of the mounting hole 53 slit and rotationally fixed in position, and its bottom end engaged in an engaging hole 93 formed in the adjusting screw 57 , thereby applying torque to the adjusting screw 57 that tends to push the adjusting screw 57 downwardly out of the nut member 54 by its torsional deformation.
- the adjusting screw 57 is thus biased by this torque in the direction to protrude downwardly from the nut member 54 .
- the protruding portion of the adjusting screw 57 protruding from the nut member 54 is in abutment with the top end of the valve stem 45 , thereby pressing the valve stem 45 .
- the external thread 56 and the internal thread 55 are vertically symmetrical triangular threads.
- an axial groove 95 is formed in the outer periphery of the adjusting screw 57 to extend across the external thread 56 from its top to bottom ends. The axial groove 95 thus separates the external thread 56 into a plurality of sections.
- Another axial groove 96 is formed in the inner periphery of the nut member 54 to extend across the internal thread 55 from its top to bottom ends, thus separating the internal thread 55 into a plurality of sections.
- the axial groves 95 and 96 have a U-shaped section, and radially align with each other, defining an insertion opening 97 between the adjusting screw 57 and the nut member 54 .
- the same initial setting member 75 as used in the third embodiment is detachably inserted in the insertion opening 97 .
- the elastic portion 76 of the initial setting member 75 is elastically compressed between the inner surface of the axial groove 95 and the inner surface of the axial groove 96 , thus producing radial elastic restoring force.
- frictional forces are produced between the elastic portion 76 and the adjusting screw 57 and between the elastic portion 76 and the nut member 54 . These frictional forces keep the adjusting screw 57 in the initial set position.
- the nut member 54 is open at both ends.
- engine oil flowing into the mounting hole 53 through the through hole 92 flows into the gap between the external thread 56 and the internal thread 55 , and is discharged through the bottom end of the nut member 54 .
- the lash adjuster 91 is mounted to the valve gear e.g. as follows.
- the adjusting screw 57 is fixed in the initial set position by inserting the initial setting member 75 in the insertion opening 97 . Then as shown in FIG. 22 , the arm 47 and the cam 46 are mounted to the valve gear. In this state, the initial setting member 75 is pulled out of the insertion opening 97 . This releases the initial set position of the adjusting screw 57 , and the adjusting screw 57 protrudes from the mounting hole while rotating under the torque of the return spring 59 , thus pressing the top end of the valve stem 45 .
- this lash adjuster 91 it is possible to fix the adjusting screw 75 in the initial set position at any desired height per pitch of the external thread 56 by screwing the adjusting screw 57 to the desired height until the axial grooves 95 and 96 are radially aligned with each other, and then inserting the initial setting member 75 into the insertion opening 97 .
- the adjusting screw 57 can be fixed in the initial set position at any desired height according to the kind of the valve lifter used.
- the axial grooves 95 and 96 are formed in the outer periphery of the adjusting screw 57 and in the inner periphery of the nut member 54 , respectively. But only one of them is sufficient. A plurality of circumferentially equidistantly spaced axial grooves 95 and 96 may be formed. With this arrangement, since the external thread 56 and the internal thread 55 axially symmetrically contact each other, the adjusting screw 57 is less likely to incline while the engine is running.
- the axial grooves 95 and 96 which have a U-shaped section, are formed in the outer periphery of the adjusting screw 57 and the inner periphery of the nut member 54 , respectively.
- a D-cut portion or two chamfers may be formed on the outer periphery of the adjusting screw 57 .
- the external thread 56 and the internal thread 55 may be trapezoidal threads.
- FIGS. 25 and 26 show the lash adjuster 101 of the fifth embodiment according to this invention. Elements corresponding to those of the fifth embodiment are denoted by identical numerals and their description is omitted.
- the adjusting screw 17 comprises a pivot member 17 A axially slidably inserted in the nut member 14 , an externally threaded member 17 B supporting the end of the pivot member 17 A inserted in the nut member 14 and having an external thread 16 on its outer periphery, and a spring washer 17 C disposed between the pivot member 17 A and the externally threaded member 17 B.
- the spring washer 17 C may be e.g. a disk spring washer or a wave washer.
- a D-cut portion 102 is formed on the outer periphery of the pivot member 17 A to extend from its portion protruding from the nut member 14 to its end inserted in the nut member 14 . As shown in FIG. 26 , the D-cut portion 102 defines an insertion opening 74 between the pivot member 17 A and the nut member 14 .
- the return spring 19 applies an axial force to the externally threaded member 17 B through a spring seat 22 that tends to push the pivot member 17 A out of the nut member 14 .
- this lash adjuster 101 as in the third embodiment, it is possible to fix the adjusting screw 17 in the initial set position at any desired height by screwing the adjusting screw 17 to the desired height and inserting the initial setting member 75 into the insertion opening 74 in this state. Also, since the adjusting screw 17 is fixed in the initial set position using the detachable initial setting member 75 , the adjusting screw 17 can be repeatedly fixed in the initial set position.
- the cut-out for defining the insertion opening 74 is the D-cut portion 102 .
- the insertion opening 74 may be defined by two chamfers or an axial groove.
- a cut-out may be formed on the inner periphery of the nut member 14 that extends downwardly from its top end.
- the spring washer 17 C is used as an elastic member to be disposed between the pivot member 17 A and the externally threaded member 17 B.
- the spring washer 17 C may be replaced by a different elastic member (such as a compression coil spring).
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- Valve-Gear Or Valve Arrangements (AREA)
Abstract
A lash adjuster is provided of which an adjusting screw can be repeatedly fixed in position.
The lash adjuster includes a nut member 14 having an internal thread 15 on an inner periphery thereof, an adjusting screw 17 having a external thread 16 on the outer periphery thereof which is in threaded engagement with the internal thread 15, and a return spring 19 biasing the adjusting screw 17 in the direction to protrude from the nut member 14, wherein the lash adjuster further includes an initial setting member 25 detachably disposed between the adjusting screw 17 and the nut member 14, and wherein the adjusting screw 17 is fixed to the nut member 14 due to frictional forces between the initial setting member 25 and the adjusting screw 17 and between the initial setting member 25 and the nut member 14.
Description
- This invention relates to a lash adjuster mounted in a valve gear for an engine.
- Valve gears for moving valves provided at engine intake ports or exhaust ports include ones having an arm pivotable about one end thereof and adapted to be pressed down by a cam at its mid-portion, thereby pressing down a valve stem at its other end (swing arm type valve gear), and ones having an arm pivotable its mid-portion and adapted to be pushed up by a cam at one end thereof, thereby pressing down a valve stem at its other end (rocker arm type valve gear).
- With these valve gears, due to differences in thermal expansion between component parts of the valve gear while the engine is running, gaps between the component parts of the valve gear tend to change, which could in turn produce noise and compression leakage. When the sliding parts of the valve gear become worn too, the gaps between the component parts of the valve gear tend to change, thus producing noise.
- In order to prevent such noise and compression leakage, valve gears ordinarily include a lash adjuster to absorb changes in gaps between component parts of the valve gear.
- A typical lash adjuster for use in a swing arm type valve gear comprises a nut member inserted in a receiving hole formed in the top surface of the cylinder head, an adjusting screw having an external thread on its outer periphery which is in threaded engagement with an internal thread formed on the inner periphery of the nut member, and a return spring biasing the adjusting screw in the direction to protrude upwardly from the nut member, thereby pivotally supporting the arm of the valve gear with the adjusting screw (Patent document 1).
- A typical lash adjuster for use in a rocker arm type valve gear comprises a nut member inserted in a receiving hole formed in the bottom surface of the arm, which pivots as the cam rotates, an adjusting screw having an external thread on its outer periphery which is in threaded engagement with an internal thread formed on the inner periphery of the nut member, and a return spring biasing the adjusting screw in the direction to protrude downwardly from the nut member, thereby pressing the valve stem of the valve gear (Patent document 2).
- With these lash adjusters, when the cam rotates and a load is applied that tends to push in the adjusting screw while the engine is running, the external thread of the adjusting screw is received by the internal thread of the nut member, so that the adjusting screw is axially fixed in position.
- With these lash adjusters, when the relative position between the arm and the valve stem changes due e.g. to thermal expansion of the valve gear, the adjusting screw axially moves while rotating in the nut member, thus adjusting gaps between component parts of the valve gear.
- When the LASH ADJUSTER is dismounted from the valve gear, the adjusting screw markedly protrudes from the nut member under the biasing force of the return spring. If the lash adjuster is mounted in the valve in this state, the valve can never be seated on the valve seat, which makes complete combustion of the engine impossible. Thus, when mounting the lash adjuster in the valve gear, it is necessary to screw the adjusting screw into the nut member and keep pressing the adjusting screw so as not to protrude from the nut member. It is troublesome to keep pressing the adjusting screw.
- In order to avoid this problem, a lash adjuster is proposed in which, in order fix the adjusting screw so as not to protrude from the nut member (initial set position), the adjusting screw is fixed in position by wax contained in the nut member (Patent document 3).
- With this lash adjuster, since the adjusting screw is fixed in position by wax, it is not necessary to keep pressing the adjusting screw when mounting the lash adjuster in the valve gear. After the lash adjuster has been mounted in the valve gear, the wax melts due to a rise in temperature while the engine is running, thus releasing the initial set position.
- Once the wax melts, it flows out of the nut member. Thus, it is impossible to reuse this wax to fix the adjusting screw in the initial set position again. Thus, it is difficult to remount the lash adjuster after it has been dismounted for overhaul of the engine.
- As another means to fix the adjusting screw in the initial set position, it would be feasible to insert a set pin through small-diameter through holes formed in the adjusting screw and the nut member, thereby rotationally fixing the adjusting screw. But in this arrangement, it is necessary to finely adjust the amount by which the adjusting screw is screwed into the nut member, which makes it troublesome to fix the adjusting screw in the initial set position. Also, since the height of the adjusting screw relative to the nut member is fixed, the initial set position is fixed too and is not changeable.
- Patent document 1: JP Patent Publication 2005-248912A
- Patent document 2: JP Patent Publication 2007-92668A
- Patent document 3: JP Patent Publication 2000-110523A
- An object of the present invention is to provide a lash adjuster of which the lash adjuster can be repeatedly fixed in the initial set position.
- In order to achieve this object, an initial setting member is detachably disposed between the adjusting screw and the nut member so that the adjusting screw is fixed to the nut member due to frictional forces between the initial setting member and the adjusting screw and between the initial setting member and the nut member. With this arrangement, by attaching and detaching the initial setting member, the adjusting screw can be repeatedly set in the initial set position.
- This lash adjuster may have e.g. one of the following structures:
- 1) The adjusting screw has a head protruding from the nut member and having a larger outer diameter than the inner diameter of the nut member, and the initial setting member comprises a pair of arm portions disposed between the head of the adjusting screw and the nut member, and a operating tab portion connecting together ends of the respective arm portions, the arm portions being elastically compressible between the head of the adjusting screw and the nut member.
- 2) A cutout is formed in at least one of the outer periphery of the adjusting screw and the inner periphery of the nut member that defines an insertion opening, and the initial setting member is inserted in the insertion opening in an elastically compressed state.
- With the lash adjuster having the above-described structure 1), when the adjusting screw is screwed into the nut member, thereby compressing the arm portions of the initial setting member between the head of the adjusting screw and the nut member, due to elastic restoring force of the arm portions, frictional forces are produced between the arm portions and the head of the adjusting screw and between the arm portions and the nut member. These frictional forces keep the adjusting screw fixed in the initial set position. By pulling out the initial setting member from between the head of the adjusting screw and the nut member, it is possible to release the initial set position of the adjusting screw.
- When the lash adjuster having the above structure 1) is used, the initial setting member may have e.g. one of the following structures:
- 1a) The initial setting member is formed by bending a metal wire, and the arm portions are formed by bending the metal wire into a corrugated shape and have elasticity.
- 1b) The initial setting member is formed by pressing a metal sheet, and the arm portions are formed by bending the metal sheet into a corrugated shape and have elasticity.
- 1c) The initial setting member is formed by injection-molding an elastic resin.
- A jig-inserting hole (30) may be formed in the operating tab portion of the initial setting member of the structure 1b) or 1c). With this arrangement, it is possible to pull out the initial setting member by inserting a jig in the jig-inserting hole, thus making it easier to release the initial set position.
- With the lash adjuster having the above-described structure 2), when the initial setting member is inserted into an insertion opening defined between the adjusting screw and the nut member in an elastically compressed state, due to elastic restoring force of the initial setting member, frictional forces are produced between the initial setting member and the adjusting screw and between the initial setting member and the nut member. These frictional forces keep the adjusting screw fixed in the initial set position. By pulling out the initial setting member out of the insertion opening, it is possible to release the initial set position of the adjusting screw.
- When the lash adjuster having the above-described structure 2) is used, the adjusting screw may comprise a pivot member axially slidably inserted in the nut member, an externally threaded member supporting the end of the pivot member inserted in the nut member and having the external thread on an outer periphery thereof, and an elastic member disposed between the pivot member and the externally threaded member. In this case, the cut-out may be formed on the outer periphery of the pivot member.
- When the lash adjuster having the structure 2) is used, the cut-out may be a D-cut portion or comprise two chamfers formed on the outer periphery of the adjusting screw.
- If the cut-out is formed so as to separate the external thread on the adjusting screw into a plurality of sections, a plurality of such cut-outs are formed so as be circumferentially equidistantly spaced from each other. With this arrangement, since the external thread and the internal thread axially symmetrically contact each other, the adjusting screw is less likely to incline while the engine is running. Also, if the adjusting screw is formed by forging, forging can be done with higher accuracy.
- When the lash adjuster having the structure 2) is used, the initial setting member may further comprise a pull-out portion which can be engaged by a finger, whereby the initial setting member can be pulled out of the insertion opening with the finger. This makes it easier to release the initial set position. The initial setting member is preferably made of rubber or resin because such an initial setting member is lighter in weight than one made of a metal such as iron.
- The present invention is applicable e.g. to the following lash adjusters:
- 1) A lash adjuster for use in a swing arm type valve gear wherein the nut member is inserted in a mounting hole formed in the top surface of a cylinder head, and wherein the adjusting screw pivotally supports an arm of the valve gear.
- 2) A lash adjuster for use in a rocker arm type valve gear wherein the nut member is inserted in a mounting hole formed in the bottom surface of an arm that pivots as a cam rotates, and wherein the adjusting screw presses a valve stem of the valve gear.
- With the lash adjuster according to the present invention, since the adjusting screw is fixed in position using the detachable initial setting member, the adjusting screw can be repeatedly set in the initial set position.
- With the arrangement in which the arm portions of the initial setting member are compressed by the head of the adjusting screw and the nut member, initial setting is complete simply by threading the adjusting screw all the way and it is never necessary to finely adjust the turning amount of the adjusting screw. Thus, initial setting is easy.
- With the arrangement in which the initial setting member is inserted in the insertion opening defined between the adjusting screw and the nut member in an elastically compressed state, it is possible to fix the adjusting screw in the initial set position at any desired height by screwing the adjusting screw to the desired height, and then inserting the initial setting member into the insertion opening.
-
FIG. 1 is a front view of a valve gear including a lash adjuster according to a first embodiment of the present invention. -
FIG. 2 is an enlarged sectional view of the lash adjuster shown inFIG. 1 , showing the state before the lash adjuster is fixed in an initial set position. -
FIG. 3 is an enlarged sectional view taken along line III-III ofFIG. 2 . -
FIG. 4 is an enlarged sectional view taken along line IV-IV ofFIG. 2 . -
FIG. 5 is an enlarged sectional view of the lash adjuster shown inFIG. 2 , showing the initial set position of the adjusting screw. -
FIG. 6 is a front view of the lash adjuster when the initial set position of the adjusting screw has been released. -
FIG. 7 is a enlarged perspective view of a modification of an initial setting member shown inFIGS. 2 to 4 . -
FIG. 8 shows how the adjusting screw is fixed in the initial set position by the initial setting member shown inFIG. 7 . -
FIG. 9 is an enlarged perspective view of another modification of the initial setting member shown inFIGS. 2 to 4 . -
FIG. 10 shows how the adjusting screw is fixed in the initial set position by the initial setting member shown inFIG. 9 . -
FIG. 11 is a front view of a valve gear including a lash adjuster according to a second embodiment of the present invention. -
FIG. 12 is an enlarged sectional view of the lash adjuster ofFIG. 11 and its surroundings. -
FIG. 13 is a front view of a valve gear including a lash adjuster according to a third embodiment of the present invention. -
FIG. 14 is an enlarged sectional view of the lash adjuster shown inFIG. 13 . -
FIG. 15 is a sectional taken along line XV-XV ofFIG. 14 . -
FIG. 16 is an enlarged sectional view of the lash adjuster showing how an elastic portion of an initial setting member shown inFIG. 14 is inserted in an insertion opening. -
FIG. 17 is an enlarged sectional view of the lash adjuster showing the state in which the elastic portion of the initial setting member shown inFIG. 14 has been pulled out of the insertion opening. -
FIG. 18 is a perspective view of the initial setting member shown inFIG. 14 . -
FIG. 19 is a sectional view of a modification of the lash adjuster ofFIG. 14 . -
FIG. 20 is a sectional view taken along line XX-XX ofFIG. 19 . -
FIG. 21 is an enlarged sectional view of the lash adjuster showing the state in which a elastic portion of an initial setting member shown inFIG. 19 has been pulled out of an insertion opening. -
FIG. 22 is a front view of a valve gear including a lash adjuster according to a fourth embodiment of the present invention. -
FIG. 23 is an enlarged sectional view of the lash adjuster shown inFIG. 22 . -
FIG. 24 is a sectional view taken along line XXIV-XXIV ofFIG. 23 . -
FIG. 25 is an enlarged sectional view of a lash adjuster according to a fifth embodiment of the present invention. -
FIG. 26 is a sectional view taken along line XXVI-XXVI ofFIG. 25 . -
- 1, 41, 71, 91, 101. Lash adjuster
- 2. Cylinder head
- 7, 47. Arm
- 13, 53. Mounting hole
- 14, 54. Nut member
- 15. Internal thread
- 16. External thread
- 17, 57. Adjusting screw
- 17A. Pivot member
- 17B. Externally threaded member
- 17C. Spring washer
- 19, 59. Return spring
- 23, 63. Head
- 25, 28, 32, 75. Initial setting member
- 26, 29, 33. Arm portion
- 27, 30, 34. Operating tab portion
- 31, 35. Jig-inserting hole
- 45. Valve stem
- 46. Cam
- 73, 95, 96. Axial groove
- 74, 97. Insertion opening
- 77. Pull-out portion
- 102. D-cut portion
-
FIG. 1 shows a valve gear including thelash adjuster 1 according to the first embodiment of the present invention. This valve gear includes avalve 4 provided at anintake port 3 of acylinder head 2 of an engine, avalve stem 5 connected to thevalve 4, and aarm 7 pivotable as acam 6 rotates. - The
valve stem 5 extends upwardly from thevalve 4 and slidably through thecylinder head 2. Anannular spring retainer 8 is fixed to the outer periphery of thevalve stem 5 at its upper portion. Avalve spring 9 is mounted between the bottom surface of thespring retainer 8 and the top surface of thecylinder head 2. Thevalve spring 9 biases thevalve stem 5 upwardly through thespring retainer 8, thereby seating thevalve 4 on avalve seat 10. - The
arm 7 has one end thereof pivotally supported by thelash adjuster 1 and the other end kept in contact with the top end of thevalve stem 5. At its central portion, thearm 7 carries aroller 11 which is pressed by thecam 6, which is provided over theroller 11. Thecam 6 is integrally formed on acamshaft 12 which rotates in unison with the engine crankshaft (not shown). - As shown in
FIGS. 1 and 2 , thelash adjuster 1 comprises acylindrical nut member 14 received in a receivinghole 13 formed in the top surface of thecylinder head 2, an adjustingscrew 17 having anexternal thread 16 on its outer periphery at its lower portion which is in threaded engagement with aninternal thread 15 formed on the inner periphery of thenut member 14, and areturn spring 19 mounted between the adjustingscrew 17 and abottom portion 18 of thenut member 14. - As shown in
FIG. 2 , theexternal thread 16 and theinternal thread 15 each have apressure flank 20 that receives pressure when a load is applied that tends to push the adjustingscrew 17 into thenut member 14. Thepressure flank 20 has a flank angle larger than theclearance flank 21 so that thethreads screw 17 that tends to push in the adjusting screw, the adjustingscrew 17 is prevented from rotating by the frictional resistance between the pressure flanks 20 of theexternal thread 16 and theinternal thread 15. When a static axial load is applied to the adjustingscrew 17 that tends to push out the adjusting screw, slip occurs between the clearance flanks 21 of theexternal thread 16 and theinternal thread 15, thus allowing rotation of the adjustingscrew 17. By way of example, the pressure flanks 20 of theexternal thread 16 and theinternal thread 15 may have a flank angle of 75°, while theirclearance flanks 21 may have a flank angle of 15°. - The
return spring 19 is a compression spring and is mounted in thenut member 15 while being axially compressed. Thereturn spring 19 has its bottom end supported on thebottom portion 18 of thenut member 14, and applies, at its top end, an axial force to the adjustingscrew 17 through aspring seat 22 that tends to push the adjustingscrew 17 out of thenut member 14, thereby biasing the adjustingscrew 17 in the direction to protrude upwardly from thenut member 14. - At its portion protruding from the top end surface of the
nut member 14, the adjustingscrew 17 has ahead 23 having an outer diameter larger than the inner diameter of thenut member 14. As shown in 1, thehead 23 is engaged in arecess 24 formed in the bottom surface of theart 7 at its end portion, thereby supporting thearm 7. Thehead 23 has a hemispherical contact surface that is in contact with therecess 24. Thearm 7 is pivotable due to sliding between thehead 23 and therecess 24. - As shown in
FIG. 2 , aninitial setting member 25 formed by bending a metal wire is inserted between the bottom end surface of thehead 23 and the top end surface of thenut member 14. As shown inFIGS. 3 and 4 , theinitial setting member 25 comprisesarm portions 26 diametrically opposed to each other with the adjustingscrew 17 disposed therebetween, and anoperating tab portion 27 connecting together ends of therespective arm portions 26. As shown inFIG. 5 , thearm portions 26 each have a corrugated portion disposed between the bottom end surface of thehead 23 and the top end surface of thenut member 14. The corrugated portions are formed by bending the wire in a corrugated shape so as to be axially elastically deformable. - The
lash adjustor 1 is assembled into the valve gear e.g. in the following manner. - As shown in
FIG. 2 , with thearm portions 26 of theinitial setting member 25 inserted between thehead 23 of the adjustingscrew 17 and thenut member 14, the adjustingscrew 17 is turned and screwed into thenut member 14 so that thearm portions 26 are compressed by the bottom end surface of thehead 23 and the top end surface of thenut member 14. At this time, as shown inFIG. 5 , due to elastic restoring force of thearm portions 26, frictional forces are produced between thearm portions 26 and thehead 23 of the adjustingscrew 17 and between thearm portions 26 and thenut member 14. These frictional forces prevent rotation of the adjustingscrew 17, thereby keeping the adjustingscrew 17 fixed in position so as not to protrude from the nut member 14 (initial set position). - Next, as shown in
FIG. 1 , thelash adjuster 1 is inserted into the receivinghole 13 of thecylinder head 2, and thearm 7 and thecamshaft 12 are mounted in position. Then as shown inFIG. 6 , theinitial setting member 25 is pulled out from between thehead 23 of the adjustingscrew 17 and thenut member 14, thus releasing the initial set position. The adjustingscrew 17 thus protrudes while rotating under the biasing force of thereturn spring 19, thus pushing up the end of thearm 7 until theroller 11 contacts thecam 6. - In this state, when the engine is started, the
cam 6 rotates, and thearm 7 is pressed down by acam lobe 6 a of thecam 6, thevalve 4 separates from thevalve seat 10, opening theintake port 3. At this time, a load is applied to the adjustingscrew 17 that tends to push in the adjusting screw. But since thepressure flank 20 of theexternal thread 16 is supported by thepressure flank 20 of theinternal thread 15, the adjustingscrew 17 is axially fixed in position. - As the
cam 6 further rotates and thecam lobe 6 a moves past theroller 11, thevalve stem 5 rises under the biasing force of thevalve spring 9, thereby seating thevalve 4 against thevalve seat 10, closing theintake port 3. - Strictly speaking, when the
arm 7 is pressed down by thecam lobe 6 a of thecam 6, slight slip occurs between the pressure flanks 20 of theexternal thread 16 and theinternal thread 15, thus pushing in the adjustingscrew 17. But once thecam lobe 6 a moves past theroller 11 and the load that tends to push in the adjusting screw is removed, the adjustingscrew 17 returns to the original position under the load from thereturn spring 19 which tends to push out the adjusting screw. - While the engine is running, if the distance between the
cam 6 and thearm 7 increases due to thermal expansion differences between component parts of the valve gear such as thecylinder head 2,valve stem 5 andarm 7, the adjustingscrew 17 protrudes by a larger amount when thecam 6 further rotate after thecam lobe 6 a of thecam 6 presses down thearm 7 until the load is removed, than the amount by which the adjustingscrew 17 is pushed in when thearm 7 is pressed down by thecam lobe 6 a of thecam 6. As a result, every time thecam 6 rotates once, the adjustingscrew 17 protrudes gradually, thus preventing any gap between thebase circle 6 b of thecam 6 and theroller 11. - Conversely, if the contact surfaces of the
valve 4 and thevalve seat 10 become worn, the biasing force of thevalve spring 9 keeps acting on the adjustingscrew 17 even while thebase circle 6 b of thecam 6 faces theroller 11. Thus, the adjustingscrew 17 protrudes by a smaller amount when thecam 6 further rotate after thecam lobe 6 a of thecam 6 presses down thearm 7 until the load is removed, than the amount by which the adjustingscrew 17 is pushed in when thearm 7 is pressed down by thecam lobe 6 a of thecam 6. As a result, every time thecam 6 rotates once, the adjustingscrew 17 is pushed in gradually, allowing thevalve stem 5 to rise. This prevents any gap between the contact surfaces of thevalve 4 and thevalve seat 10. - When the valve gear is dismounted from the
camshaft 12 for overhaul of the engine, the adjustingscrew 17 protrudes from thenut member 14 under the biasing force of thereturn spring 19. In this state, by threading the adjustingscrew 17 into thenut member 14 by turning the adjustingscrew 17, with the initial setting member inserted between thehead 23 of the adjustingscrew 17 and thenut member 14, the adjustingscrew 17 can be again set in the initial set position. - With this lash
adjuster 1, since the adjustingscrew 17 can be fixed in position using the detachably insertedinitial setting member 25, the adjustingscrew 17 can be repeatedly set in the initial set position. - As an alternative way of setting the adjusting
screw 17 in the initial set position, it may be feasible to insert a set pin through small-diameter through holes formed in the adjustingscrew 17 and thenut member 14. But in this arrangement, it is difficult to align the through hole formed in the adjustingscrew 17 with the through hole formed in thenut member 14 by finely adjusting the turning amount of the adjustingscrew 17, and thus initial setting is troublesome. In contrast, with thelash adjuster 1, initial setting is complete simply by threading the adjustingscrew 17 all the way and it is never necessary to finely adjust the turning amount of the adjusting screw. Thus, initial setting is easy. - With this lash
adjuster 1, since it is not necessary to form through holes for inserting a set pin in the adjustingscrew 17 and thenut member 14, its manufacturing cost is low. - In this embodiment, the initial setting member to be disposed between the
head 23 of the adjustingscrew 17 and thenut member 14 is theinitial setting member 25 formed by bending a metal wire material. But instead of this initial settingmember 25, aninitial setting member 28 as shown inFIGS. 7 and 8 may be used, which is formed by pressing a metal sheet material. - As shown in
FIGS. 7 and 8 , theinitial setting member 28 comprises two diametricallyopposed arm portions 29, and anoperating tab portion 30 connecting together two respective ends of thearm portions 29. Thearm portions 29 each have a corrugated portion disposed between the bottom end surface of thehead 23 and the top end surface of thenut member 14. The corrugated portions are formed by bending the sheet material in a corrugated shape so as to be axially elastically deformable. Theoperating tab portion 30 is formed with a vertically extending jig-inserting throughhole 31. Theinitial setting member 28 can be pulled out by inserting a jig (not shown) into the jig-insertinghole 31. - Also, instead of the
initial setting member 25, aninitial setting member 32 shown inFIGS. 9 and 10 may be used, which is formed by injection-molding an elastic resin. As shown inFIGS. 9 and 10 , theinitial setting member 32 comprises two diametricallyopposed arm portions 33, and anoperating tab portion 34 connecting together two respective ends of thearm portions 33. Theoperating tab portion 34 is formed with a vertically extending jig-inserting throughhole 35. Theinitial setting member 32 can be pulled out by inserting a jig into the jig-insertinghole 35. -
FIG. 11 shows a valve gear to which thelash adjuster 41 of the second embodiment according to this invention is mounted. This valve gear includes avalve 44 provided at anintake port 43 of acylinder head 42 of an engine, avalve stem 45 connected to thevalve 44, and anarm 47 that pivots as acam 46 rotates. - The valve stem 45 extends upwardly from the
valve 44. Aspring retainer 48 is fixed to the upper portion of thevalve stem 45. Avalve spring 49 biases thespring retainer 48, thereby seating thevalve 44 against avalve seat 50. - The
arm 47 has its central portion pivotally supported by apivot shaft 51, and carries at one end thereof aroller 52 that is in contact with thecam 46. Thelash adjuster 41 is mounted to the other end of thearm 47. Thecam 46, which is provided under thearm 47, rotates together with the engine crankshaft (not shown), thereby pivoting thearm 47 by pressing theroller 52 with itscam lobe 46 b, which protrudes from itsbase circle 46 a. - As shown in
FIG. 12 , thelash adjuster 41 comprises atubular nut member 54 inserted in a mountinghole 53 formed in the bottom surface of thearm 47, an adjustingscrew 57 having anexternal thread 56 on its outer periphery at its upper portion which is in threaded engagement with aninternal thread 55 formed on the inner periphery of thenut member 54, and areturn spring 59 mounted between the adjustingscrew 57 and theinner bottom surface 58 of the mountinghole 53. - The
external thread 56 and theinternal thread 55 each have apressure flank 60 that receives pressure when a load is applied that tends to push the adjustingscrew 57 into thenut member 54. Thepressure flank 60 has a flank angle larger than theclearance flank 61 so that thethreads screw 57 that tends to push in the adjustingscrew 57, the adjustingscrew 57 is prevented from rotating by the frictional resistance between the pressure flanks 60 of theexternal thread 56 and theinternal thread 55. When a static axial load is applied to the adjustingscrew 57 that tends to push out the adjusting screw, slip occurs between the clearance flanks 61 of theexternal thread 56 and theinternal thread 55, thus allowing rotation of the adjustingscrew 57. - The
return spring 59 is a compression coil spring having its top end supported by theinner bottom surface 58 of the mountinghole 53 and applies, at its bottom end, an axial force to the adjustingscrew 57 through aspring seat 62 that tends to push the adjustingscrew 57 out of thenut member 54, thereby biasing the adjustingscrew 57 in the direction to protrude downwardly from thenut member 54. - At its portion protruding from the bottom end surface of the
nut member 54, the adjustingscrew 57 has ahead 63 having an outer diameter larger than the inner diameter of thenut member 54. Thehead 63 presses the top end of thevalve stem 45. - The same initial setting
member 25 as used in the first embodiment is inserted between the top end surface of thehead 63 and the bottom end surface of thenut member 54. Thus, theinitial setting member 25 comprises the diametricallyopposed arm portions 26 and theoperating tab 27 connecting together two respective ends of thearm portions 26. - With this lash
adjuster 41, as in the first embodiment, with thearm portions 26 of theinitial setting member 25 inserted between thehead 63 of the adjustingscrew 57 and thenut member 54, the adjustingscrew 57 is turned and screwed into thenut member 54 so that thearm portions 26 are compressed by the bottom end surface of thehead 63 and the top end surface of thenut member 54. At this time, due to elastic restoring force of thearm portions 26, frictional forces are produced between thearm portions 26 and thehead 63 and between thearm portions 26 and thenut member 54. These frictional forces keep the adjustingscrew 57 fixed in the initial set position. - By pulling out the
initial setting member 25 from between thehead 63 and thenut member 54, it is possible to release the initial set position of the adjustingscrew 57. The adjustingscrew 57 thus protrudes while rotating under the biasing force of thereturn spring 59, thus pivoting thearm 47 until theroller 52 contacts thebase circle 46 a of thecam 46. - With this lash
adjuster 41, since the adjustingscrew 57 can be fixed in position using the detachably insertedinitial setting member 25, the adjustingscrew 57 can be repeatedly set in the initial set position. Since initial setting is complete simply by threading the adjustingscrew 57 into thenut member 54, initial setting is easy. Also, since it is not necessary to form through holes for inserting a set pin in the adjustingscrew 57 and thenut member 54, its manufacturing cost is low. - With this lash
adjuster 41 too, instead of theinitial setting member 25, it is possible to use theinitial setting member 28, which is formed by pressing a metal sheet material (FIGS. 7 and 8 ), or theinitial setting member 32, which is formed by injection-molding an elastic resin (FIGS. 9 and 10 ). -
FIG. 13 shows thelash adjuster 71 of the third embodiment. Elements corresponding to those of the first embodiment are denoted by identical numerals and their description is omitted. - The adjusting
screw 17 has a hemisphericalprotruding end 72 protruding from thenut member 14. The protrudingend 72 is fitted in arecess 24 formed in the bottom surface of thearm 7 and supports thearm 7. Thearm 7 pivotable as the protrudingend 72 slides in therecess 24. - As shown in
FIGS. 14 and 15 , anaxial groove 73 is formed in the outer periphery of the adjustingscrew 17 to extend across theexternal thread 16 from its top to bottom ends. Theaxial groove 73 thus separates theexternal thread 16 into a plurality of sections. Theaxial groove 73 has a U-shaped section, and defines aninsertion opening 74 between the adjustingscrew 17 and thenut member 14. - An
initial setting member 75 is detachably inserted in theinsertion opening 74. Theinitial setting member 75 comprises anelastic portion 76 inserted in theinsertion opening 74, a ring-shaped pull-outportion 77, and a connectingportion 78 connecting the pull-outportion 77 to theelastic portion 76. Theinitial setting member 75 is integrally formed from resin or rubber. - As shown in
FIGS. 16 to 18 , theelastic portion 76 is a bifurcated member having arms extending in the direction opposite to the direction in which theelastic portion 76 is inserted. Theelastic portion 76 is thus elastically compressed between the inner surface of theaxial groove 73 and thepressure flank 20 of the internal thread, thereby producing elastic restoring force, which in turn produces frictional forces between theelastic portion 76 and the adjustingscrew 17 and between theelastic portion 76 and thenut member 14. These frictional forces prevent rotation of the adjustingscrew 17, thus keeping the adjustingscrew 17 from protruding from thenut member 14. - When the
initial setting member 75 is inserted into theinsertion opening 74, if the free ends of the bifurcated arms of theelastic portion 76 enter theinsertion opening 74, they may be caught on theinternal thread 15 when theinitial setting member 75 is pulled out of theinsertion opening 74. Thus, in order to prevent the free ends of the bifurcated arms of theelastic portion 76 from entering theinsertion opening 74, theelastic portion 76 has astopper 79 adapted to abut the top end of thenut member 14 when theelastic portion 76 is inserted into theinsertion opening 74. - As shown in
FIG. 14 , a throughhole 80 is formed in the bottom 18 of thenut member 14 that extends vertically through the bottom 18. As shown inFIG. 13 , anoil discharge hole 81 is formed in the inner bottom surface of the mountinghole 13 which communicates with the throughhole 80. Thus, engine oil flowing into the gap between theexternal thread 16 and theinternal thread 15 from the top end surface of thenut member 14 is discharged through the throughhole 80 and then theoil discharge hole 81. - The
lash adjuster 71 is mounted to the valve gear e.g. as follows. - As shown in
FIG. 14 , the adjustingscrew 17 is fixed in the initial set position by inserting theinitial setting member 75 in theinsertion opening 74. Then as shown inFIG. 13 , thelash adjuster 71 is inserted into the mountinghole 13, and thearm 7 and thecamshaft 12 are mounted in position. In this state, theinitial setting member 75 is pulled out of theinsertion opening 74 by engaging a finger or a tool with the pull-outportion 77. This releases the initial set position of the adjustingscrew 17, and the adjustingscrew 17 protrudes from the mounting hole while rotating under the biasing force of thereturn spring 19, thus pushing up thearm 7 until theroller 11 abuts thecam 6. - With this lash
adjuster 71, it is possible to fix the adjustingscrew 75 in the initial set position at any desired height by screwing the adjustingscrew 17 to the desired height, and then inserting theinitial setting member 75 into theinsertion opening 74. Thus, if thelash adjuster 71 is used for different kinds of valve lifters, the adjustingscrew 17 can be fixed in the initial set position at any desired height according to the kind of the valve lifter used. - With this lash
adjuster 71, engine oil flowing into theaxial groove 73 from the top end surface of thenut member 14 flows into the gap between theexternal thread 16 and theinternal thread 15, thus lubricating theexternal thread 16 and theinternal thread 15. This makes theexternal thread 16 and theinternal thread 15 less likely to become worn. - With this lash
adjuster 71, since theinitial setting member 75 is made of resin or rubber, theinitial setting member 75 is lighter in weight than a similar initial setting member made of a metal such as iron. Theinitial setting member 75 is preferably made of resin because it is more easily recyclable. - With this lash
adjuster 71, as with the first embodiment, since the adjustingscrew 17 is fixed in the initial set position using the detachableinitial setting member 75, the adjustingscrew 17 can be repeatedly fixed in the initial set position. Also, since theinitial setting member 75 can be inserted irrespective of the position of the adjustingscrew 17 relative to the mounting hole, it is not necessary to finely adjust the turning amount of the adjustingscrew 17. Thus, initial setting is easy. - In this embodiment, the
elastic portion 76 of theinitial set member 75 is bifurcated. But as shown inFIGS. 19 to 21 , theelastic portion 76 may be spherically shaped. InFIGS. 19 to 21 , the sphericalelastic portion 76 is sized such that it is elastically compressed when inserted into theinsertion opening 74. - In
FIG. 15 , only oneaxial groove 73 may be formed. But as shown inFIG. 20 , a plurality of circumferentially equidistantly spacedaxial grooves 73 may be formed. With this arrangement, since theexternal thread 16 and theinternal thread 15 axially symmetrically contact each other, the adjustingscrew 17 is less likely to incline while the engine is running. Also, if the adjustingscrew 17 is formed by forging, forging can be done with higher accuracy. - In this embodiment, in order to define the insertion opening between the adjusting
screw 17 and thenut member 14, theaxial groove 73 is formed in the outer periphery of the adjustingscrew 17. But such an axial groove may be formed in the inner periphery of thenut member 14 instead of in the outer periphery of the adjustingscrew 17. Further alternatively, such axial grooves may be formed both in the outer periphery of the adjustingscrew 17 and in the inner periphery of thenut member 14. - In the above embodiment, the cut-out defining the
insertion opening 74 is theaxial groove 73. But instead. the insertion opening may be defined by a D-cut portion or two chamfers formed on the outer periphery of the adjustingscrew 17. The D-cut portion is a cut-out on the outer surface of the adjustingscrew 17 extending along a plane parallel to a plane including the axis of the adjustingscrew 17. The two chamfers are two flat surfaces formed by cutting out the outer periphery of the adjustingscrew 17 so as to extend parallel to a plane including the axis of the adjustingscrew 17. - In this embodiment, a compression coil spring is used as the
return spring 19 for biasing the adjustingscrew 17. But instead of a compression coil spring, a torsion coil spring may be used. In this case, theexternal thread 16 and theinternal thread 15 may be trapezoidal threads or triangular threads. -
FIGS. 22 and 24 show thelash adjuster 91 of the fourth embodiment according to this invention. Elements corresponding to those of the second embodiment are denoted by identical numerals and their description is omitted. - The
return spring 59 is a torsion coil spring having its top end engaged in a throughhole 92 formed in the inner bottom surface of the mountinghole 53 slit and rotationally fixed in position, and its bottom end engaged in an engaginghole 93 formed in the adjustingscrew 57, thereby applying torque to the adjustingscrew 57 that tends to push the adjustingscrew 57 downwardly out of thenut member 54 by its torsional deformation. The adjustingscrew 57 is thus biased by this torque in the direction to protrude downwardly from thenut member 54. The protruding portion of the adjustingscrew 57 protruding from thenut member 54 is in abutment with the top end of thevalve stem 45, thereby pressing thevalve stem 45. - The
external thread 56 and theinternal thread 55 are vertically symmetrical triangular threads. As shown inFIG. 23 , anaxial groove 95 is formed in the outer periphery of the adjustingscrew 57 to extend across theexternal thread 56 from its top to bottom ends. Theaxial groove 95 thus separates theexternal thread 56 into a plurality of sections. Anotheraxial groove 96 is formed in the inner periphery of thenut member 54 to extend across theinternal thread 55 from its top to bottom ends, thus separating theinternal thread 55 into a plurality of sections. As shown inFIG. 24 , theaxial groves insertion opening 97 between the adjustingscrew 57 and thenut member 54. The same initial settingmember 75 as used in the third embodiment is detachably inserted in theinsertion opening 97. - As shown in
FIGS. 22 and 23 , theelastic portion 76 of theinitial setting member 75 is elastically compressed between the inner surface of theaxial groove 95 and the inner surface of theaxial groove 96, thus producing radial elastic restoring force. As a result, frictional forces are produced between theelastic portion 76 and the adjustingscrew 57 and between theelastic portion 76 and thenut member 54. These frictional forces keep the adjustingscrew 57 in the initial set position. - As shown in
FIG. 23 , thenut member 54 is open at both ends. Thus, engine oil flowing into the mountinghole 53 through the throughhole 92 flows into the gap between theexternal thread 56 and theinternal thread 55, and is discharged through the bottom end of thenut member 54. - The
lash adjuster 91 is mounted to the valve gear e.g. as follows. - The adjusting
screw 57 is fixed in the initial set position by inserting theinitial setting member 75 in theinsertion opening 97. Then as shown inFIG. 22 , thearm 47 and thecam 46 are mounted to the valve gear. In this state, theinitial setting member 75 is pulled out of theinsertion opening 97. This releases the initial set position of the adjustingscrew 57, and the adjustingscrew 57 protrudes from the mounting hole while rotating under the torque of thereturn spring 59, thus pressing the top end of thevalve stem 45. - With this lash
adjuster 91, it is possible to fix the adjustingscrew 75 in the initial set position at any desired height per pitch of theexternal thread 56 by screwing the adjustingscrew 57 to the desired height until theaxial grooves initial setting member 75 into theinsertion opening 97. Thus, if thelash adjuster 91 is used for different kinds of valve lifters, the adjustingscrew 57 can be fixed in the initial set position at any desired height according to the kind of the valve lifter used. - With this lash
adjuster 71, engine oil flowing into theaxial grooves external thread 56 and theinternal thread 55, thus lubricating theexternal thread 56 and theinternal thread 55. This makes theexternal thread 56 and theinternal thread 55 less likely to become worn. - With this lash
adjuster 91, since the adjustingscrew 57 is fixed in the initial set position using the detachableinitial setting member 75, the adjustingscrew 57 can be repeatedly fixed in the initial set position. - In this embodiment, the
axial grooves screw 57 and in the inner periphery of thenut member 54, respectively. But only one of them is sufficient. A plurality of circumferentially equidistantly spacedaxial grooves external thread 56 and theinternal thread 55 axially symmetrically contact each other, the adjustingscrew 57 is less likely to incline while the engine is running. - In this embodiment, as cut-outs for defining the
insertion opening 97, theaxial grooves screw 57 and the inner periphery of thenut member 54, respectively. But in order to define theinsertion opening 97, a D-cut portion or two chamfers may be formed on the outer periphery of the adjustingscrew 57. Theexternal thread 56 and theinternal thread 55 may be trapezoidal threads. -
FIGS. 25 and 26 show thelash adjuster 101 of the fifth embodiment according to this invention. Elements corresponding to those of the fifth embodiment are denoted by identical numerals and their description is omitted. - The adjusting
screw 17 comprises apivot member 17A axially slidably inserted in thenut member 14, an externally threaded member 17B supporting the end of thepivot member 17A inserted in thenut member 14 and having anexternal thread 16 on its outer periphery, and aspring washer 17C disposed between thepivot member 17A and the externally threaded member 17B. Thespring washer 17C may be e.g. a disk spring washer or a wave washer. - A D-cut
portion 102 is formed on the outer periphery of thepivot member 17A to extend from its portion protruding from thenut member 14 to its end inserted in thenut member 14. As shown inFIG. 26 , the D-cutportion 102 defines aninsertion opening 74 between thepivot member 17A and thenut member 14. Thereturn spring 19 applies an axial force to the externally threaded member 17B through aspring seat 22 that tends to push thepivot member 17A out of thenut member 14. - With this lash
adjuster 101, as in the third embodiment, it is possible to fix the adjustingscrew 17 in the initial set position at any desired height by screwing the adjustingscrew 17 to the desired height and inserting theinitial setting member 75 into theinsertion opening 74 in this state. Also, since the adjustingscrew 17 is fixed in the initial set position using the detachableinitial setting member 75, the adjustingscrew 17 can be repeatedly fixed in the initial set position. - With this lash
adjuster 101, engine oil flows from the top end surface of thenut member 14 into thenut member 14 through the D-cutportion 102, thus sufficiently lubricating theexternal thread 16 and theinternal thread 15. This makes theexternal thread 16 and theinternal thread 15 less likely to become worn. - In this embodiment, the cut-out for defining the
insertion opening 74 is the D-cutportion 102. But instead of the D-cutportion 102, theinsertion opening 74 may be defined by two chamfers or an axial groove. Further alternatively, a cut-out may be formed on the inner periphery of thenut member 14 that extends downwardly from its top end. - In this embodiment, the
spring washer 17C is used as an elastic member to be disposed between thepivot member 17A and the externally threaded member 17B. But thespring washer 17C may be replaced by a different elastic member (such as a compression coil spring).
Claims (19)
1. A lash adjuster comprising a nut member (14) having an internal thread (15) on an inner periphery thereof, an adjusting screw (17) having a external thread (16) on an outer periphery thereof which is in threaded engagement with the internal thread (15), and a return spring (19) biasing the adjusting screw (17) in a direction to protrude from the nut member (14),
characterized in that the lash adjuster further comprises an initial setting member (25, 75) detachably disposed between the adjusting screw (17) and the nut member (14), wherein the adjusting screw (17) is fixed to the nut member (14) due to frictional forces between the initial setting member (25, 75) and the adjusting screw (17) and between the initial setting member (25, 75) and the nut member (14).
2. The lash adjuster of claim 1 wherein said adjusting screw (17) has a head (23) protruding from the nut member (14) and having a larger outer diameter than an inner diameter of the nut member (14), and wherein said initial setting member (25) comprises a pair of arm portions (26) disposed between the head (23) of the adjusting screw (17) and the nut member (14), and a operating tab portion (27) connecting together ends of the respective arm portions (26), said arm portions (26) being elastically compressible between the head (23) of the adjusting screw (17) and the nut member (14).
3. The lash adjuster of claim 2 wherein said initial setting member (25) is formed by bending a metal wire, and wherein said arm portions (26) are formed by bending the metal wire into a corrugated shape and have elasticity.
4. The lash adjuster of claim 2 wherein said initial setting member (28) is formed by pressing a metal sheet, and wherein said arm portions (29) are formed by bending the metal sheet into a corrugated shape and have elasticity.
5. The lash adjuster of claim 2 wherein said initial setting member (32) is formed by injection-molding an elastic resin.
6. The lash adjuster of claim 4 wherein the operating tab portion (30) is formed with a jig-inserting hole (31) for inserting a jig.
7. The lash adjuster of claim 1 wherein a cutout (73) is formed in at least one of the outer periphery of the adjusting screw (17) and the inner periphery of the nut member (14) that defines an insertion opening (74), and wherein the initial setting member (75) is inserted in the insertion opening (74) in an elastically compressed state.
8. The lash adjuster of claim 7 wherein the adjusting screw (17) comprises a pivot member (17A) axially slidably inserted in the nut member (14), an externally threaded member (17B) supporting an end of the pivot member (17A) inserted in the nut member (14) and having said external thread (16) on an outer periphery thereof, and an elastic member (17C) disposed between the pivot member (17A) and the externally threaded member (17B), and wherein said cut-out (102) is formed on an outer periphery of the pivot member (17A).
9. The lash adjuster of claim 7 wherein said cut-out is a D-cut portion (102) formed on the outer periphery of the adjusting screw (57).
10. The lash adjuster of claim 7 wherein said cut-out comprises two chamfers formed on the outer periphery of the adjusting screw (17).
11. The lash adjuster of claim 7 wherein there are a plurality of said cut-outs (73), each cut-out (73) separating the external thread (16) on the outer periphery of the adjusting screw (17) into a plurality of sections, and wherein said plurality of cut-outs (73) being circumferentially equidistantly spaced from each other.
12. The lash adjuster of claim 7 wherein the initial setting member (75) further comprises a pull-out portion (77) which can be engaged by a finger, whereby the initial setting member (75) can be pulled out of the insertion opening (74) with the finger.
13. The lash adjuster of claim 7 wherein said initial setting member (75) is made of rubber or resin.
14. The lash adjuster of claim 1 wherein the nut member (14) is inserted in a mounting hole (13) formed in a top surface of a cylinder head (2), and wherein the adjusting screw (17) pivotally supports an arm (7) of a valve gear.
15. The lash adjuster of claim 1 wherein the nut member (54) is inserted in a mounting hole (53) formed in a bottom surface of an arm (47) that pivots as a cam (46) rotates, and wherein the adjusting screw (57) presses a valve stem of a valve gear.
16. The lash adjuster of claim 5 wherein the operating tab portion (30) is formed with a jig-inserting hole (31) for inserting a jig.
17. The lash adjuster of claim 8 wherein said cut-out is a D-cut portion (102) formed on the outer periphery of the adjusting screw (57).
18. The lash adjuster of claim 8 wherein said cut-out comprises two chamfers formed on the outer periphery of the adjusting screw (17).
19. The lash adjuster of claim 8 wherein there are a plurality of said cut-outs (73), each cut-out (73) separating the external thread (16) on the outer periphery of the adjusting screw (17) into a plurality of sections, and wherein said plurality of cut-outs (73) being circumferentially equidistantly spaced from each other.
Applications Claiming Priority (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2008-083362 | 2008-03-27 | ||
JP2008083362A JP2009236007A (en) | 2008-03-27 | 2008-03-27 | Lash adjuster |
JP2008211537A JP2010048124A (en) | 2008-08-20 | 2008-08-20 | Lash adjuster |
JP2008-211537 | 2008-08-20 | ||
PCT/JP2009/055249 WO2009119398A1 (en) | 2008-03-27 | 2009-03-18 | Lash adjuster |
Publications (1)
Publication Number | Publication Date |
---|---|
US20110017161A1 true US20110017161A1 (en) | 2011-01-27 |
Family
ID=41113595
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US12/922,695 Abandoned US20110017161A1 (en) | 2008-03-27 | 2009-03-18 | Lash adjuster |
Country Status (3)
Country | Link |
---|---|
US (1) | US20110017161A1 (en) |
DE (1) | DE112009000725T5 (en) |
WO (1) | WO2009119398A1 (en) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20100263613A1 (en) * | 2007-12-07 | 2010-10-21 | Makoto Yasui | Lash adjuster |
US20120227695A1 (en) * | 2009-12-18 | 2012-09-13 | Masashi Bokura | Arm type valve lifter |
US20160210871A1 (en) * | 2015-01-19 | 2016-07-21 | The Boeing Company | Instructional Assessment System for a Vehicle |
US11008901B1 (en) | 2019-11-22 | 2021-05-18 | Caterpillar Inc. | Rocker arm assembly with air venting |
US11454139B2 (en) * | 2016-07-19 | 2022-09-27 | Eaton Intelligent Power Limited | Method for valvetrain lash adjustment with extra lost motion stroke and high stiffness lost motion spring |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3791355A (en) * | 1972-02-24 | 1974-02-12 | Johnson Products Inc | Mechanical lash adjuster for overhead cam engines |
Family Cites Families (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH07650Y2 (en) * | 1987-10-13 | 1995-01-11 | エヌティエヌ株式会社 | Lash adjuster device |
JP3794836B2 (en) | 1998-10-05 | 2006-07-12 | Ntn株式会社 | Valve lifter |
JP4215663B2 (en) | 2004-03-08 | 2009-01-28 | Ntn株式会社 | Automatic valve clearance adjustment device |
JP2007092668A (en) | 2005-09-29 | 2007-04-12 | Ntn Corp | Arm type valve gear |
WO2009041364A1 (en) * | 2007-09-26 | 2009-04-02 | Ntn Corporation | Rush adjuster |
-
2009
- 2009-03-18 WO PCT/JP2009/055249 patent/WO2009119398A1/en active Application Filing
- 2009-03-18 DE DE112009000725T patent/DE112009000725T5/en not_active Withdrawn
- 2009-03-18 US US12/922,695 patent/US20110017161A1/en not_active Abandoned
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3791355A (en) * | 1972-02-24 | 1974-02-12 | Johnson Products Inc | Mechanical lash adjuster for overhead cam engines |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20100263613A1 (en) * | 2007-12-07 | 2010-10-21 | Makoto Yasui | Lash adjuster |
US20120227695A1 (en) * | 2009-12-18 | 2012-09-13 | Masashi Bokura | Arm type valve lifter |
US20160210871A1 (en) * | 2015-01-19 | 2016-07-21 | The Boeing Company | Instructional Assessment System for a Vehicle |
US11454139B2 (en) * | 2016-07-19 | 2022-09-27 | Eaton Intelligent Power Limited | Method for valvetrain lash adjustment with extra lost motion stroke and high stiffness lost motion spring |
US11008901B1 (en) | 2019-11-22 | 2021-05-18 | Caterpillar Inc. | Rocker arm assembly with air venting |
Also Published As
Publication number | Publication date |
---|---|
WO2009119398A1 (en) | 2009-10-01 |
DE112009000725T5 (en) | 2011-02-24 |
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AS | Assignment |
Owner name: NTN CORPORATION, JAPAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:YASUI, MAKOTO;MAENO, EIJI;YAMAGUCHI, KATSUHISA;SIGNING DATES FROM 20100817 TO 20100819;REEL/FRAME:024988/0030 |
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