JP2010159644A - Lash adjuster - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lash adjuster capable of preventing rise of working cost of a cylinder head and excellent in lubricity of a rocking support point of an arm. <P>SOLUTION: This lash adjustor employs a structure including the arm 7 pressed downward by a cam 6 of a valve gear, a bottomed cylinder shape nut member 12 inserted in a storage hole 11 opening to an end part lower surface of the arm 7, an adjust screw 15 including an external screw 14 screwed in an internal screw 13 formed on an inner circumference of the nut member 12 on an outer circumference thereof, a torsion spring 16 applying torque in a direction projecting downward from a nut member 12 on the adjust screw 15, and a receive member 17 having a recessed part 27 fitting to a semispherical pivot part 26 formed on a projection end from the nut member 12 of the adjust screw 15 formed on an upper surface, and pushing down a valve stem 5 of the valve gear by a rocking side end part of the arm 7 rocking with the receiving member 17 used as a fulcrum. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a lash adjuster incorporated in an engine valve gear.

  As a valve operating device that operates a valve provided at the intake port or exhaust port of an engine, the central part of the arm supported so as to be swingable with one end as a fulcrum is pushed down by a cam, and the valve stem is What is pushed down is known.

  In this valve operating device, the gap between the constituent members of the valve operating device (for example, between the cam and the arm) changes due to the difference in thermal expansion that occurs between the constituent members of the valve operating device during engine operation, and the change in the clearance. May cause abnormal noise or compression leakage. Further, even if the sliding portion of the valve operating device wears, there is a possibility that a gap between constituent members of the valve operating device (for example, between the valve and the valve seat) changes, and abnormal noise may be generated due to the change in the clearance. .

  In order to prevent this abnormal noise and compression leakage, generally, a lash adjuster is incorporated in the valve operating device, and the lash adjuster absorbs a change in a gap between components of the valve operating device.

  As such a lash adjuster, it has a bottomed cylindrical nut member inserted into a receiving hole opened on the upper surface of the cylinder head, and a male screw that engages with a female screw formed on the inner periphery of the nut member on the outer periphery. One having an adjustment screw and a torsion spring that imparts a rotational force in a direction protruding upward from a nut member to the adjustment screw is known (Patent Document 1).

  In this lash adjuster, a hemispherical pivot portion is formed at the projecting end of the adjusting screw from the nut member, and the pivot portion is fitted into a recess formed on the lower surface of the end portion of the arm of the valve operating device. Support swingable.

  Here, when the arm swings according to the rotation of the cam, a load in the pushing direction is applied to the adjustment screw, but the rotation of the adjustment screw is prevented by the frictional resistance between the pressure side flank of the male screw and the female screw, As a result, the axial position of the adjusting screw is fixed.

  Strictly speaking, a slight slip occurs between the pressure flank of the male screw and the female screw at this time, and the adjustment screw moves in the pushing direction due to the sliding, but when the cam further rotates and the load in the pushing direction is released. In addition, the adjustment screw moves in the protruding direction by the force of the torsion spring and returns to the original position.

  Further, when the relative position of the arm and the valve stem changes due to thermal expansion of the valve operating device, the adjusting screw moves in the axial direction while rotating in the nut member according to the change in position, and the valve operating device The change in the gap between the constituent members is absorbed.

Japanese Utility Model Publication No. 64-34407

  By the way, since the lash adjuster has a nut member accommodation hole in the cylinder head, it is necessary to perform deep hole machining on the cylinder head, and the machining cost of the cylinder head is high.

  The lash adjuster lubricates between the pivot part and the recess with engine oil splashed on the arm, but this recess opens downward, so the engine oil enters between the pivot part and the recess. Hateful. For this reason, the pivot portion and the concave portion were easily worn.

  The problem to be solved by the present invention is to provide a lash adjuster that can reduce the machining cost of the cylinder head and is excellent in lubricity of the swing fulcrum of the arm.

  In order to solve the above-mentioned problems, an arm pressed downward by a cam of a valve operating device, a bottomed cylindrical nut member inserted into a receiving hole opened on the lower surface of the end of the arm, and the nut member An adjusting screw having a male screw on the outer periphery that engages with a female screw formed on the inner periphery, a torsion spring that applies a rotational force in a direction of projecting downward from the nut member to the adjusting screw, and a nut member of the adjusting screw And a receiving member formed on the upper surface with a concave portion that fits into a hemispherical pivot formed at the protruding end of the arm, and the valve operating device at the swinging side end of the arm that swings with the receiving member as a fulcrum The lash adjuster has a configuration that pushes down the valve stem.

  If it does in this way, since the accommodation hole of a nut member is in an arm, it is not necessary to carry out deep hole processing on a cylinder head, and processing cost of a cylinder head can be held down. Further, since the concave portion fitted to the pivot portion is opened upward, the engine oil splashed on the arm easily enters between the pivot portion and the concave portion, and the lubricity between the pivot portion and the concave portion is high.

  The recess is preferably provided with an oil reservoir in the center thereof. In this way, if foreign matter such as suits or contamination enters the engine oil, the foreign matter will fall into the oil reservoir, making it difficult for foreign matter to bite between the contact surfaces of the pivot part and the concave part. Abrasion can be more effectively suppressed.

  When the accommodation hole is a bottomed hole, the arm is formed with an oil introduction hole that penetrates from the upper surface of the arm to the bottom surface of the accommodation hole, and the bottom portion of the nut member communicates with the oil introduction hole. It is preferable to form oil holes. In this way, the engine oil splashed on the arm is introduced into the nut member through the oil introduction hole and the oil passage hole in order, so that the lubricity between the male screw of the adjusting screw and the female screw of the nut member is improved. Get higher.

  Moreover, when the said accommodation hole is a through-hole which penetrates the said nut member up and down, it is preferable to form the oil-permeable hole which penetrates a bottom part up and down in the bottom part of the said nut member. In this case, the engine oil splashed on the arm is introduced into the nut member through the oil passage hole at the bottom of the nut member, so that the lubricity between the male screw of the adjusting screw and the female screw of the nut member is improved. Get higher.

  The nut member may be fixed by being press-fitted into the accommodation hole, may be fixed by welding to the arm, or may be fixed by caulking to the arm. As described above, when the nut member is fixed to the arm, it is possible to prevent the nut member from dropping off from the arm in a state before the arm is assembled to the valve operating device. Becomes higher.

  A flange that contacts the lower surface of the arm can be provided on the outer periphery of the lower end of the nut member. If it does in this way, since the flange receives the upward force which acts on a nut member, the accommodation hole can be used as a penetration hole, and processing of an arm becomes easy.

  The arm may be formed of aluminum or may be formed by press forming of iron.

  The receiving member can be fixed to the upper surface of the cylinder head. The male screw and the female screw may be a sawtooth screw, a triangular screw, or a trapezoidal screw. Examples of the torsion spring include a torsion coil spring, a spring, and a bamboo spring.

  The adjustment screw includes a pivot member inserted into the nut member so as to be slidable in the axial direction, a male screw member supporting an insertion end of the pivot member into the nut member, and having the male screw on an outer periphery, and the pivot member And an elastic member sandwiched between male screw members.

  In this case, a square hole is formed at the insertion end of the pivot member into the nut member, and a square shaft that fits into the square hole is formed in the male screw member. It is preferable that the pivot member and the male screw member rotate together. If it does in this way, since a male screw member can be rotated by rotation operation of a pivot member, the operation | work which assembles a male screw member in a nut member is easy.

  In the lash adjuster according to the present invention, since the accommodation hole for the nut member is in the arm, it is not necessary to perform deep hole machining on the cylinder head. Therefore, the processing cost of the cylinder head can be suppressed. In addition, since the concave portion that fits into the pivot portion is opened upward, the engine oil splashed on the arm easily enters between the pivot portion and the concave portion, and the lubricity of the swing fulcrum of the arm is high.

  Also, in the case where an oil sump is provided in the center of the recess, when foreign matter such as a suit or contamination enters the engine oil, the foreign matter falls into the oil sump, so there is no foreign matter between the contact surfaces of the pivot part and the recess. It is difficult to bite and the pivot part and the concave part are not easily worn.

The front view which shows the valve operating apparatus incorporating the lash adjuster of 1st Embodiment of this invention Enlarged sectional view of the end of the arm shown in FIG. The expanded sectional view which shows the modification which welded and fixed the nut member shown in FIG. 2 to an arm FIG. 2 is an enlarged cross-sectional view showing a modified example in which the nut member shown in FIG. The expanded sectional view which shows the modification which provided the flange in the lower end outer periphery of the nut member shown in FIG. FIG. 2 is an enlarged sectional view showing a modification of the male screw and the female screw shown in FIG. The expanded sectional view which shows the other modification of the external thread shown in FIG. 2, and an internal thread The expanded sectional view which shows the lash adjuster of 2nd Embodiment of this invention FIG. 8 is an enlarged sectional view showing a modification of the torsion spring shown in FIG. FIG. 8 is an enlarged sectional view showing another modification of the torsion spring shown in FIG. FIG. 8 is an enlarged sectional view showing still another modification of the torsion spring shown in FIG. Sectional drawing along the XII-XII line of FIG. FIG. 1 is an enlarged cross-sectional view showing a modification in which the arm shown in FIG. 1 is formed by press forming of iron. The figure which looked at the arm shown in FIG. 13 from the lower side

  FIG. 1 shows a valve gear incorporating a lash adjuster 1 according to a 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.

  As shown in FIGS. 1 and 2, the lash adjuster 1 includes an arm 7 made of aluminum, a bottomed cylindrical nut member 12 inserted into a receiving hole 11 opened on the lower surface of the end of the arm 7, and An adjusting screw 15 having an external thread 14 engaged with an internal thread 13 formed on the inner periphery of the nut member 12 on the outer periphery, a torsion spring 16 incorporated between the bottom of the nut member 12 and the adjusting screw 15, and a cylinder head 2 and a receiving member 17 fixed to the upper surface of 2. The receiving member 17 is press-fitted and fixed in a fitting recess 18 formed on the upper surface of the cylinder head 2.

  As shown in FIG. 2, the nut member 12 has a bottom portion 19 at the insertion end into the accommodation hole 11. The nut member 12 is press-fitted into the accommodation hole 11 and fixed. The accommodation hole 11 is a non-through hole with a bottom.

  The arm 7 is formed with an oil introduction hole 20 penetrating from the upper surface of the arm 7 to the bottom surface of the accommodation hole 11. An oil passage hole 21 communicating with the oil introduction hole 20 is formed in the bottom portion 19 of the nut member 12, and engine oil splashed on the arm 7 passes through the oil introduction hole 20 and the oil passage hole 21 in order. It is introduced into the nut member 12 through. The engine oil introduced into the nut member 12 lubricates between the male screw 14 and the female screw 13.

  The male screw 14 and the female screw 13 are formed in a sawtooth shape having an asymmetrical cross section along the axis, and are pressure-side flank that receives pressure when a load in the direction of pushing the adjusting screw 15 into the nut member 12 is applied. The flank angle of 22 is larger than the flank angle of the play side flank 23.

  The torsion spring 16 is a torsion coil spring formed by spirally winding a metal wire. The torsion spring 16 has an upper end locked in a locking hole 24 formed in the bottom portion 19 of the nut member 12 and a lower end locked in a locking hole 25 formed in the adjusting screw 15. A rotational force that projects downward from the nut member 12 is applied to the adjusting screw 15 by torsional deformation. A hemispherical pivot portion 26 is formed at the protruding end of the adjusting screw 15 from the nut member 12.

  On the upper surface of the receiving member 17, a hemispherical concave portion 27 that fits into the pivot portion 26 is formed, and the arm 7 is supported and supported to be swingable with the receiving member 17 as a fulcrum. The recess 27 is formed such that the opening diameter at its upper end is 10% or more larger than the outer diameter of the pivot portion 26, and the engine oil splashed on the arm 7 is between the recess 27 and the pivot portion 26. Through the annular opening formed in the upper portion, the concave portion 27 is efficiently accumulated. An oil reservoir 28 is formed at the center of the recess 27.

  As shown in FIG. 1, the arm 7 is in contact with the upper end of the valve stem 5 at the end opposite to the side where the accommodation hole 11 is formed. A roller 29 is attached to the center of the arm 7, and the roller 29 is in contact with the cam 6 provided above the arm 7. The cam 6 is integrally formed with a camshaft 30 that rotates in synchronization with a crankshaft (not shown) of the engine. When the camshaft 30 rotates, a cam crest 6b that is raised with respect to the base circle 6a is formed. The arm 7 is pressed downward via the roller 29. At this time, the arm 7 swings around the receiving member 17 as a fulcrum, and pushes down the valve stem 5 at the end of the swing side.

  Next, an operation example of the lash adjuster 1 will be described.

  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 15, but the rotation of the adjustment screw 15 is prevented by the frictional resistance between the pressure side flank 22, 22 of the male screw 14 and the female screw 13. The axial position is fixed.

  When the cam 6 further rotates and the cam crest 6b passes the position of the roller 29, 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.

  Strictly speaking, when the cam crest 6b of the cam 6 pushes down the arm 7, a slight slip occurs between the pressure side flank 22, 22 of the male screw 14 and the female screw 13, and the adjustment screw 15 moves in the pushing direction by the slip. However, when the cam crest 6b passes the position of the roller 29 and the load in the pushing direction is released, the adjustment screw 15 moves in the protruding direction by the force of the torsion spring 16 and returns to the original position.

  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 15 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 15 when the cam crest 6b pushes down the arm 7. As a result, each time the cam 6 rotates, the adjusting screw 15 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 29.

  On the contrary, when the contact surface between the valve 4 and the valve seat 10 is worn, the biasing force of the valve spring 9 acts on the adjustment screw 15 even when the base circle 6a of the cam 6 is at the position of the roller 29. The amount of protrusion of the adjusting screw 15 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 15 when the cam crest 6b of the cam 6 pushes down the arm 7. As a result, each time the cam 6 rotates, the adjusting screw 15 gradually moves 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.

  In the lash adjuster 1, since the accommodation hole 11 of the nut member 12 is in the arm 7, it is not necessary to perform deep hole machining on the cylinder head 2. Therefore, the processing cost of the cylinder head 2 can be suppressed. Further, since the concave portion 27 fitted to the pivot portion 26 is opened upward, the engine oil splashed on the arm 7 easily enters between the pivot portion 26 and the concave portion 27, and the swing fulcrum of the arm 7 High lubricity.

  The lash adjuster 1 also prevents foreign matter from getting caught between the contact surfaces of the pivot portion 26 and the recessed portion 27 when foreign matter such as suits and contaminants are mixed into the engine oil because the foreign matter falls into the oil reservoir 28. The pivot part 26 and the recessed part 27 are not easily worn.

  Further, in this lash adjuster 1, the engine oil splashed on the arm 7 is introduced into the nut member 12 through the oil introduction hole 20 and the oil passage hole 21 in order, and therefore, between the male screw 14 and the female screw 13. Lubricity is high and the male screw 14 and the female screw 13 are not easily worn.

  In addition, since the engine oil introduced into the nut member 12 passes downwardly between the male screw 14 and the female screw 13, the lash adjuster 1 has a foreign matter such as contamination mixed into the engine oil. It is difficult to bite between the male screw 14 and the female screw 13, and operation reliability is high.

  Further, in the lash adjuster 1, the nut member 12 and the adjusting screw 15 can be assembled to the arm 7 at the stage of manufacturing the lash adjuster 1. Therefore, when the engine is assembled, the nut member 12 and the adjusting screw 15 are connected to the cylinder head 2. There is no need to assemble it. Therefore, the number of assembling steps of the engine can be reduced as compared with the case where the nut member 12 and the adjusting screw 15 are on the cylinder head 2 side.

  In addition, since the nut member 12 is fixed to the arm 7, the lash adjuster 1 can prevent the nut member 12 from dropping from the arm 7 before the arm 7 is assembled to the valve gear. The assembly workability of the arm 7 to the valve gear is excellent.

  In the above embodiment, the nut member 12 is press-fitted and fixed in the receiving hole 11, but the nut member 12 may be fixed by welding to the arm 7 as shown in FIG. 7 may be fixed by caulking.

  Further, as shown in FIG. 5, a flange 31 that contacts the lower surface of the arm 7 may be formed on the outer periphery of the lower end of the nut member 12. If it does in this way, since the upward force which acts on the nut member 12 will receive the flange 31, the accommodation hole 11 can be made into a through-hole, and the process of the arm 7 becomes easy.

  As shown in FIG. 6, the male screw 14 and the female screw 13 may adopt a vertically symmetrical triangular screw, or may adopt a vertically symmetrical trapezoidal screw as shown in FIG.

  In the above embodiment, the receiving member 17 is press-fitted into the fitting recess 18 and fixed. However, the receiving member 17 may be fixed to the cylinder head 2 by welding the receiving member 17 to the cylinder head 2. The receiving member 17 may be fastened to the head 2 with a bolt.

  Next, a lash adjuster according to a second embodiment of the present invention will be described. Portions corresponding to the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIG. 8, the adjusting screw 15 supports a pivot member 15A inserted into the nut member 12 so as to be slidable in the axial direction, an insertion end of the pivot member 15A into the nut member 12, and a male screw 14 It consists of a male screw member 15B on the outer periphery and a spring washer 15C sandwiched between the pivot member 15A and the male screw member 15B. As the spring washer 15C, for example, a disc spring washer or a corrugated washer can be used.

  At the open end of the nut member 12, an annular retaining member 32 that passes through the pivot member 15A is mounted. The pivot member 15 </ b> A has an annular groove 33 formed in a portion crossing the open end of the nut member 12, and the retaining member 32 enters the groove 33, whereby the pivot member 15 </ b> A is retained from the nut member 12. Yes.

  The pivot member 15 </ b> A has a pivot portion 26 at the protruding end from the nut member 12. Further, the pivot member 15 </ b> A has a square hole 34 formed at the center of the insertion end into the nut member 12. The male screw member 15B is formed with a square shaft 35 that fits into the square hole 34. When the pivot member 15A is rotated, the pivot member 15A and the male screw member 15B are fitted by fitting the square shaft 35 and the square hole 34. Are designed to rotate together.

  The torsion spring 16 has an upper end locked in a locking hole 24 formed in the bottom portion 19 of the nut member 12, and a lower end locked in a locking hole 25 formed in the male screw member 15B. By the torsional deformation, a rotational force in a direction in which the pivot member 15A protrudes downward from the nut member 12 is applied to the male screw member 15B.

  In this lash adjuster, as in the first embodiment, the concave portion 27 fitted to the pivot portion 26 is opened upward, so that engine oil splashed on the arm 7 is interposed between the pivot portion 26 and the concave portion 27. It is easy to enter and the lubricity of the swing fulcrum of the arm 7 is high. Other effects are the same as those of the first embodiment.

  Further, the lash adjuster is a spring between the male screw member 15B and the pivot member 15A when the engine is stopped in a high temperature state and thereafter the engine is cooled to cause a contraction difference between the components of the valve gear. By compressing the washer 15C, the contraction difference is absorbed. Therefore, when the engine is restarted, a gap due to a contraction difference between the constituent members of the valve operating device does not occur between the valve 4 and the valve seat 10, and compression leakage does not occur.

  Further, in this lash adjuster, since the pivot member 15A and the male screw member 15B are rotated together by fitting the square shaft 35 and the square hole 34, the male screw member 15B is rotated by rotating the pivot member 15A. Can be made. Therefore, the work of assembling the male screw member 15B into the nut member 12 is easier than in the case where the square shaft 35 and the square hole 34 are not provided.

  In this embodiment, the spring washer 15C is used as an elastic member sandwiched between the pivot member 15A and the male screw member 15B. However, another elastic member (for example, a compression coil spring) may be used instead of the spring washer 15C. .

  As shown in FIG. 8, the torsion spring 16 may be a cylindrically wound one, or as shown in FIG. 9, a conical one may be used.

  In each of the above-described embodiments, a torsion coil spring is employed as the torsion spring 16 that gives the adjusting screw 15 a rotational force that projects downward from the nut member. However, as shown in FIGS. Alternatively, a torsion spring 16 (for example, a spring or a bamboo spring) may be employed.

  In FIG. 10, the torsion spring 16 is a mainspring spring in which a thin plate material is wound in a spiral shape. The large-diameter end of the torsion spring 16 is prevented from rotating around the bottom portion 19 of the nut member 12, and the small-diameter end is inserted into a slit formed in the protrusion 36 at the insertion end of the male screw member 15B into the nut member 12, By the torsional deformation, a rotational force in a direction in which the pivot member 15A protrudes downward from the nut member 12 is applied to the male screw member 15B. The external thread 14 on the outer periphery of the external thread member 15B and the internal thread 13 on the inner periphery of the nut member 12 are vertically symmetrical triangular screws.

  11 and 12, the torsion spring 16 is a bamboo child spring in which a thin plate material is spirally wound. The large-diameter end of the torsion spring 16 is prevented from rotating around the bottom 19 of the nut member 12, and the small-diameter end is inserted into a slit formed in the projection 37 at the insertion end of the male screw member 15B into the nut member 12. By the torsional deformation, a rotational force in a direction in which the pivot member 15A protrudes downward from the nut member 12 is applied to the male screw member 15B. The male screw 14 on the outer periphery of the male screw member 15B and the female screw 13 on the inner periphery of the nut member 12 are vertically symmetrical trapezoidal screws.

  In each of the above embodiments, the lash adjuster in which the arm 7 is formed of aluminum has been described as an example. However, as shown in FIGS. 13 and 14, the present invention provides the arm 7 by press forming (forging or the like) of iron. The present invention can also be applied to the formed lash adjuster.

  13 and 14, the arm 7 connects the opposite walls 38, 38 that face each other with the roller 29 interposed therebetween, the horizontal wall 39 that connects one ends of the opposite walls 38, 38, and the other ends. It consists of a horizontal wall 40.

  The horizontal wall 39 is formed with a receiving hole 11 that opens to the lower surface thereof. The nut member 12 is inserted into the receiving hole 11, and the flange 31 formed on the outer periphery of the lower end of the nut member 12 is connected to the horizontal wall 39. It is in contact with the lower surface. Here, the accommodation hole 11 is a through hole that allows the nut member 12 to vertically penetrate therethrough. The other horizontal wall 40 contacts the upper end of the valve stem 5 shown in FIG.

  An oil passage hole 21 is formed in the bottom portion 19 of the nut member 12 so as to penetrate the bottom portion 19 in the vertical direction. Engine oil splashed on the arm 7 passes through the oil passage hole 21 and enters the nut member 12. It has been introduced.

  Thus, when the arm 7 is formed by iron press molding, it is possible to reduce the thickness of the arm 7 by reducing the thickness of the arm 7 than when the arm 7 is formed by casting.

1 Rush Adjuster 5 Valve Stem 6 Cam 7 Arm 11 Housing Hole 12 Nut Member 13 Female Thread 14 Male Thread 15 Adjust Screw 15A Pivot Member 15B Male Thread Member 15C Spring Washer 16 Torsion Spring 17 Receiving Member 19 Bottom 20 Oil Introduction Hole 21 Oil Through Hole 26 Pivot Portion 27 Recess 28 Oil reservoir 31 Flange 34 Square hole 35 Square shaft

Claims (15)

  An arm (7) pressed downward by the cam (6) of the valve gear, and a bottomed cylindrical nut member (12) inserted into a receiving hole (11) opened in the lower surface of the end of the arm (7) ), An adjustment screw (15) having a male screw (14) on the outer periphery thereof, which is engaged with a female screw (13) formed on the inner periphery of the nut member (12), and a nut member (15) on the adjustment screw (15). 12) a torsion spring (16) for applying a rotational force in a direction protruding downward from the nut, and a hemispherical pivot portion (26) formed at the protruding end of the adjusting screw (15) from the nut member (12). A receiving member (17) having a fitting recess (27) formed on the upper surface, and the swinging end of the arm (7) swinging with the receiving member (17) as a fulcrum. Press down on the valve stem (5) Lash adjuster was.   The lash adjuster according to claim 1, wherein an oil sump (28) is provided in the center of the recess (27).   The accommodation hole (11) is a bottomed hole, and the arm (7) is formed with an oil introduction hole (20) penetrating from the upper surface of the arm (7) to the bottom surface of the accommodation hole (11), and the nut The lash adjuster according to claim 1 or 2, wherein an oil passage hole (21) communicating with the oil introduction hole (20) is formed in a bottom portion (19) of the member (12).   The accommodation hole (11) is a through hole that vertically penetrates the nut member (12), and the bottom (19) of the nut member (12) has an oil passage hole that vertically penetrates the bottom (19). The lash adjuster according to claim 1 or 2, wherein (21) is formed.   The lash adjuster according to any one of claims 1 to 4, wherein the nut member (12) is press-fitted and fixed in the accommodation hole (11).   The lash adjuster according to any one of claims 1 to 4, wherein the nut member (12) is fixed to the arm (7) by welding.   The lash adjuster according to any one of claims 1 to 4, wherein the nut member (12) is fixed by caulking to the arm (7).   The lash adjuster according to any one of claims 1 to 7, wherein a flange (31) that contacts the lower surface of the arm (7) is provided on an outer periphery of a lower end of the nut member (12).   The lash adjuster according to any one of claims 1 to 8, wherein the arm (7) is made of aluminum.   The lash adjuster according to any one of claims 1 to 8, wherein the arm (7) is formed by press forming of iron.   The lash adjuster according to any one of claims 1 to 10, wherein the receiving member (17) is fixed to an upper surface of the cylinder head (2).   The lash adjuster according to any one of claims 1 to 11, wherein the male screw (14) and the female screw (13) are sawtooth screws, triangular screws, or trapezoidal screws.   The lash adjuster according to any one of claims 1 to 12, wherein the torsion spring (16) is any one of a torsion coil spring, a spring, and a bamboo spring.   The adjustment screw (15) has a pivot member (15A) inserted into the nut member (12) so as to be slidable in the axial direction, and an insertion end of the pivot member (15A) into the nut member (12). A male screw member (15B) supporting and having the male screw (14) on the outer periphery, and an elastic member (15C) sandwiched between the pivot member (15A) and the male screw member (15B). The lash adjuster according to any one of the above.   A square hole (34) is formed at an insertion end of the pivot member (15A) into the nut member (12), and a square shaft (35) fitted into the square hole (34) is formed on the male screw member (15B). 15. The lash adjuster according to claim 14, wherein the pivot member (15A) and the male screw member (15B) are integrally rotated by fitting the angular axis (35) and the square hole (34).

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