JP2009270500A - Lash adjuster - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lash adjuster superior in productivity of a nut member. <P>SOLUTION: This lash adjuster of a valve gear includes the nut member 14 having a female screw 15 on the inner periphery, an adjusting screw 17 having on the outer periphery a male screw 16 engaging by a screw with the female screw 15 of its nut member 14, and a return spring 18 incorporated into the nut member 14, and is provided so that the male screw 16 and the female screw 15 are formed in a sawtooth shape larger than a flank angle of a play side flank 21 in a flank angle of a pressure side flank 20 for receiving pressure when a load is applied in the direction for pushing the adjusting screw 17 in the nut member 14. The nut member 14 is molded in a pipe shape of opening both ends, and adopts a constitution having the female screw 15 over its total length. <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 moved at the other end of the arm. One end of the arm that is pushed down (swing arm type valve operating device) or the arm supported so as to be able to swing with the center as a fulcrum is pushed up with a cam, and the valve stem is pushed down at the other end of the arm A thing (rocker arm type valve gear) is known.

  In these valve operating apparatuses, during engine operation, gaps between the constituent members of the valve operating apparatus change due to thermal expansion differences that occur between the constituent members of the valve operating apparatus, and abnormal noise and compression leakage occur due to changes in the gaps. There is a fear. Further, even if the sliding portion of the valve operating device is worn, the gap between the constituent members of the valve operating device changes, and there is a possibility that abnormal noise is generated due to the change in the clearance.

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

  As such a lash adjuster, in the above swing arm type valve gear, the nut member inserted into the accommodation hole opened on the upper surface of the cylinder head and the female screw formed on the inner periphery of the nut member are screw-engaged. An adjusting screw having a male screw on the outer periphery, and a return spring that urges the adjusting screw in a direction protruding upward from the nut member. The protruding end of the adjusting screw from the nut member holds the arm of the valve gear. There is known one that can swingably (Patent Document 1).

  Further, in the rocker arm type valve gear, the screw member is engaged with a nut member inserted into a receiving hole opened in the lower surface of the arm that swings according to the rotation of the cam, and a female screw formed on the inner periphery of the nut member. An adjusting screw having a male screw on the outer periphery thereof, and a return spring for biasing the adjusting screw in a direction protruding downward from the nut member, and a protruding end of the adjusting screw from the nut member What presses a valve stem is known (patent document 2).

  In these lash adjusters, the male screw of the adjusting screw and the female screw of the nut member are the pressure side flank that receives pressure when a load in the direction in which the adjusting screw is pushed into the nut member (hereinafter referred to as the “pushing direction”) is applied. The flank angle is formed in a sawtooth shape larger than the flank angle of the play side flank, and when a static load in the push-in direction is applied to the adjustment screw, it is adjusted by the frictional resistance between the pressure side flank of the male screw and the female screw. When the screw is prevented from rotating and, on the other hand, when a static load in the protruding direction is applied to the adjusting screw, the adjusting screw is allowed to rotate by sliding between the play side flank of the male screw and the female screw.

  Therefore, when a load in the pushing direction is applied to the adjustment screw due to the rotation of the cam, the pressure side flank of the male screw is received by the pressure side flank of the female screw, and the axial position of the adjustment 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 due to the load in the protruding direction applied from the return spring, and returns to the original position.

  In addition, when the gap between the components of the valve operating device becomes large due to thermal expansion of the valve operating device, the cam is further pushed than the adjustment screw is pushed in when the load in the pushing direction is applied by the cam. The amount of protrusion of the adjusting screw when the load in the pushing direction is released by rotation is increased. As a result, each time the cam rotates, the adjustment screw gradually moves in the protruding direction to absorb the change in the gap between the constituent members of the valve gear.

On the other hand, when the gap between the components of the valve operating device becomes small, the cam rotates further than the amount of pushing of the adjusting screw when the load in the pushing direction is applied by the cam. The protruding amount of the adjusting screw when released is reduced. As a result, each time the cam rotates, the adjustment screw gradually moves in the push-in direction to absorb the change in the gap between the constituent members of the valve gear.
JP 2005-273510 A JP 2006-132426 A

  By the way, in the lash adjuster described in Patent Document 1, since the nut member is integrally formed in a bottomed cylindrical shape, the tip end of the tap interferes with the bottom of the nut member when the internal thread of the nut member is processed with the tap. It is necessary to perform processing within the range that does not. Therefore, the feed of the tapping process cannot be made fast, and the productivity of the nut member is low.

  On the other hand, since both ends of the nut member are open in the lash adjuster described in Patent Document 2, there is nothing that interferes with the tip of the tap when tapping the internal thread of the inner periphery of the nut member. As a result, the tapping feed can be made faster.

  However, the nut member of this lash adjuster has a female thread only in the portion of the entire length that comes into contact with the adjusting screw, and the tapping of the female thread is performed for each individual nut member. Here, if tapping of a plurality of nut members can be performed at once, the productivity of the nut members can be further increased, but such a lash adjuster has not been known yet.

  Further, in the lash adjuster described in Patent Document 1, since the nut member is integrally formed in a bottomed cylindrical shape, when the return spring is inserted into the nut member when the lash adjuster is assembled, the return spring is recessed. It was hard to see and it was difficult to check whether the return spring was inserted all the way without being caught.

  The problem to be solved by the present invention is to provide a lash adjuster excellent in productivity of nut members.

  In order to solve the above-mentioned problems, the nut member is formed into a pipe shape having both ends opened, and a structure having the female screw over the entire length of the nut member is employed.

  If it does in this way, since the both ends of a nut member are open | released, when tapping the internal thread of the inner periphery of a nut member, there is nothing which interferes with the front-end | tip of a tap. As a result, the tapping feed can be made faster. Also, since the nut member has a female thread over the entire length of the nut member, each nut member is cut by tapping the female thread on the inner periphery of the pipe material having a length corresponding to a plurality of nut members, and then cutting the pipe material. Can be produced. Therefore, tapping for a plurality of nut members can be performed at once, and the productivity of the nut members is high.

  Further, since both ends of the nut member are open, when assembling the lash adjuster, an adjustment screw can be screwed from one end of the nut member, and then a return spring can be inserted from the other end of the nut member. Therefore, it is easy to see the return spring inserted into the nut member, and it is easy to check whether the return spring is inserted without being caught.

  Further, a spring seat having a cylindrical outer peripheral surface can be press-fitted into the nut member, and the return spring can be supported by the spring seat. In this way, a spiral gap is formed between the outer peripheral surface of the spring seat and the female screw of the nut member, and the gap can be used as a passage for lubricating oil that lubricates between the male screw and the female screw. Become.

  Further, a spring seat having an external thread on the outer periphery can be screwed into the nut member, and the return spring can be supported by the spring seat. In this way, when maintaining the lash adjuster, the spring seat can be rotated and removed from the nut member, so that the lash adjuster can be maintained more easily than when the spring seat is press-fitted into the nut member.

  In addition, a retaining ring may be attached to a circumferential groove formed on the inner periphery of the nut member, and the return spring may be supported by the retaining ring.

  When a spring seat having an external thread on the outer periphery is screwed into the nut member, it is preferable to provide a flange portion that abuts against the end surface of the nut member on the spring seat. In this way, the spring seat can be positioned in the axial direction by the contact between the flange portion and the nut member.

  Further, if a tool engagement groove for rotating the spring seat is provided in the flange portion, a tool such as a screwdriver can be engaged with the tool engagement groove, so that the operation of screwing the spring seat into the nut member can be performed. It's easy to do.

  When a non-slip groove is provided on the outer periphery of the flange portion, when the flange portion is held by hand and the spring seat is screwed into the nut member, slippage is unlikely to occur between the hand having the flange portion and the flange portion. Therefore, the operation of screwing the spring seat into the nut member is easy.

  As the material of the spring seat, iron, aluminum, resin, or the like can be used.

Each said structure is employable as the following lash adjuster, for example.
1) The nut member is inserted into a receiving hole opened in the upper surface of the cylinder head, and the adjusting screw swingably supports the arm of the valve operating device at a protruding end from the nut member. Rush adjuster for equipment.
2) The nut member is inserted into a receiving hole opened on the lower surface of the arm that swings according to the rotation of the cam, and the adjusting screw presses the valve stem of the valve operating device at the protruding end from the nut member. Rush adjuster for rocker arm type valve gear.

  The lash adjuster of the present invention can produce a nut member by tapping a female thread on the inner periphery of a pipe material having a length corresponding to a plurality of nut members and then cutting the pipe material. Therefore, tapping for a plurality of nut members can be performed at once, and the productivity of the nut members is high.

  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.

  One end of the arm 7 is supported by the lash adjuster 1, and the other end is in contact with the upper end of the valve stem 5. A roller 11 is attached to the central portion of the arm 7, and the roller 11 is in contact with a cam 6 provided above the arm 7. The cam 6 is integrally formed with a camshaft 12 that rotates in synchronization with the crankshaft (not shown) of the engine. When the camshaft 12 rotates, a cam crest 6b that is raised with respect to the base circle 6a is formed. The arm 7 is pushed down via the roller 11.

  As shown in FIGS. 1 and 2, the lash adjuster 1 is screwed into a nut member 14 inserted into a receiving hole 13 opened in the upper surface of the cylinder head 2 and a female screw 15 formed on the inner periphery of the nut member 14. An adjustment screw 17 having a male screw 16 to be joined on the outer periphery of the lower part, a return spring 18 incorporated in the nut member 14, and a spring seat 19 fixed to the lower end of the nut member 14.

  As shown in FIG. 2, the nut member 14 is formed in a pipe shape with both ends open, and the female screw 15 is formed over the entire length of the nut member 14. The nut member 14 can be produced by tapping a female screw 15 on the inner periphery of an iron pipe member having a length corresponding to a plurality of nut members 14 and then cutting the pipe member.

  The male screw 16 and the female screw 15 have a sawtooth shape in which the flank angle of the pressure-side flank 20 that receives pressure when a load in the direction of pushing the adjusting screw 17 into the nut member 14 is applied is larger than the flank angle of the play-side flank 21. When the static load in the pushing direction is applied to the adjustment screw 17, the rotation of the adjustment screw 17 is prevented by the frictional resistance between the pressure side flank 20, 20 of the male screw 16 and the female screw 15, When a static load in the protruding direction is applied to the adjusting screw 17, the adjusting screw 17 is allowed to rotate by sliding between the play side flank 21, 21 of the male screw 16 and the female screw 15. As the male screw 16 and the female screw 15, for example, those having a flank angle of the pressure side flank 20 of 75 ° and a flank angle of the play side flank 21 of 15 ° can be employed.

  The spring seat 19 is formed in a bottomed cylindrical shape having a cylindrical outer peripheral surface, and is press-fitted into the nut member 14 with an open end facing downward, and the outer peripheral surface of the spring seat 19 and the female screw of the nut member 14 A spiral gap 22 is formed between the two terminals 15 and 15. Further, a notch 23 penetrating in the radial direction is formed at the open end of the spring seat 19. Further, as shown in FIG. 1, an oil drain hole 24 communicating with the outside is formed on the inner bottom surface of the accommodation hole 13. Therefore, the lubricating oil that has flowed into the nut member 14 from the upper end surface of the nut member 14 through the gap between the male screw 16 and the female screw 15 and the spiral gap 22 between the spring seat 19 and the nut member 14 and the spring seat 19. The oil is discharged from the nut member 14 through the notch 23 and the oil drain hole 24 in order. As a material of the spring seat 19, iron, aluminum, resin or the like can be adopted. When iron or aluminum is employed, the spring seat 19 can be formed by forging or pressing. When resin is employed, the spring seat 19 can be formed by injection molding.

  As shown in FIG. 2, the return spring 18 has a lower end supported by a spring seat 19 and an upper end pressing the adjustment screw 17 via a spring seat 25, and the adjustment screw 17 is removed from the nut member 14 by the pressing. It is biased in a direction that protrudes upward.

  As shown in FIG. 1, the adjusting screw 17 has a hemispherical protruding end 26 from the nut member 14, and the protruding end 26 is fitted into a recess 27 formed on the lower surface of the end of the arm 7. is doing. Here, the protruding end 26 is slidably in contact with the inner surface of the recess 27, and supports the arm 7 so as to be swingable by the sliding.

  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 adjusting screw 17, but the pressure side flank 20 of the male screw 16 is received by the pressure side flank 20 of the female screw 15, and the axial position of the adjusting screw 17 is fixed.

  When the cam 6 further rotates and the cam crest 6b passes the position of the roller 11, the valve stem 5 is raised by the urging force of the valve spring 9, the valve 4 is seated on the valve seat 10, and the intake port 3 is close.

  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 20, 20 of the male screw 16 and the female screw 15, and the adjustment screw 17 moves in the pushing direction by the slip. However, when the cam crest 6b passes the position of the roller 11 and the load in the pushing direction is released, the adjustment screw 17 moves in the protruding direction due to the load in the protruding direction loaded from the return spring 18, Return 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 17 when the cam 6 rotates and the load in the pushing direction is released is larger than the amount of pushing of the adjusting screw 17 when the cam crest 6b pushes down the arm 7. As a result, each time the cam 6 rotates, the adjusting screw 17 gradually moves in the protruding direction, so that no gap is generated between the base circle 6 a of the cam 6 and the roller 11.

  On the contrary, when the contact surface of the valve 4 and the valve seat 10 is worn, the biasing force of the valve spring 9 acts on the adjustment screw 17 even when the base circle 6a of the cam 6 is at the position of the roller 11. The amount of protrusion of the adjusting screw 17 when the cam 6 rotates and the load in the pushing direction is released is smaller than the amount of pushing of the adjusting screw 17 when the cam crest 6b of the cam 6 pushes down the arm 7. As a result, each time the cam 6 rotates, the adjustment screw 17 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 both ends of the nut member 14 are open, there is nothing that interferes with the tip of the tap when the internal thread 15 on the inner periphery of the nut member 14 is tapped. As a result, the tapping feed can be made faster. In addition, since the nut member 14 has the female thread 15 over the entire length, the female thread 15 is tapped on the inner periphery of the pipe material having a length corresponding to a plurality of nut members 14, and then the pipe material is cut. The nut member 14 can be produced. Therefore, the lash adjuster 1 can perform tapping for a plurality of nut members 14 at a time, and the productivity of the nut members 14 is high.

  Since the lash adjuster 1 has both ends of the nut member 14 open, when assembling the lash adjuster 1, the adjust screw 17 is screwed from one end of the nut member 14, and then returned from the other end of the nut member 14. A spring 18 can be inserted. Therefore, it is easy to see the return spring 18 inserted into the nut member 14, and it is easy to check whether the return spring 18 is inserted without being caught.

  3 and 4 show a lash adjuster 31 according to a second embodiment of the present invention. Portions corresponding to the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  A spring seat 32 that supports the lower end of the return spring 18 is provided at the lower end of the nut member 14.

  The spring seat 32 includes a screw shaft portion 33 having a male screw on the outer periphery and a flange portion 34 provided continuously with one end of the screw shaft portion 33. In the spring seat 32, the screw shaft portion 33 is screwed into the nut member 14, and the flange portion 34 is in contact with the lower end surface of the nut member 14.

  The flange portion 34 is formed with a tool engagement groove 35 extending in the radial direction on the lower surface thereof, and a tool such as a screwdriver can be engaged with the tool engagement groove 35 to rotate the spring seat 32. It has become.

  Further, the spring seat 32 is formed with an oil passage hole 36 penetrating vertically, and the lubricating oil flowing into the nut member 14 from the upper end surface of the nut member 14 through the gap between the male screw 16 and the female screw 15, The oil is discharged from the nut member 14 through the oil passage hole 36. As a material of the spring seat 32, iron, aluminum, resin, or the like can be adopted.

  The lash adjuster 31 can be removed from the nut member 14 by rotating the spring seat 32 during maintenance of the inside thereof. Therefore, the lash adjuster 31 (for example, the first embodiment) in which the spring seat is press-fitted into the nut member 14 can be removed. Compared with the lash adjuster 1), maintenance is easier.

  In the lash adjuster 31, when the spring seat 32 is screwed into the nut member 14, the flange portion 34 comes into contact with the lower end surface of the nut member 14, and the spring seat 32 is positioned in the axial direction by the contact. Therefore, there is no worry of screwing the spring seat 32 excessively, and the assembly work of the spring seat 32 is easy.

  In addition, since the lash adjuster 31 can engage a tool such as a screwdriver in the tool engagement groove 35 of the flange portion 34, it is easy to screw the spring seat 32 into the nut member 14.

  In this embodiment, the tool engagement groove 35 is provided on the lower surface of the flange portion 34. However, as shown in FIG. 5, a non-slip groove 37 (for example, knurled eyes) may be provided on the outer periphery of the flange portion 34. In this case, when the spring portion 32 is screwed into the nut member 14 by holding the flange portion 34 by hand, the spring seat 32 is less likely to slip between the hand having the flange portion 34 and the flange portion 34. Can be easily screwed into the nut member 14.

  As a spring seat for supporting the return spring 18, as shown in FIG. 6, a retaining ring 39 attached to a circumferential groove 38 formed on the inner periphery of the nut member 14 can be adopted.

  FIG. 7 shows a valve gear incorporating a lash adjuster 41 according to the third embodiment of the present invention. As in the above embodiment, this valve operating device swings in response to the rotation of the valve 44 provided in the intake port 43 of the cylinder head 42 of the engine, the valve stem 45 connected to the valve 44, and the cam 46. And an arm 47.

  The valve stem 45 extends upward from the valve 44, and a spring retainer 48 is fixed to the upper portion of the valve stem 45. The spring retainer 48 is biased upward by a valve spring 49, and the valve 44 is seated on the valve seat 50 by the biasing force.

  The center of the arm 47 is supported by a fulcrum shaft 51 so as to be swingable. A roller 52 that contacts the cam 46 is attached to one end of the arm 47, and a lash adjuster 41 is incorporated into the other end of the arm 47. The cam 46 provided below the arm 47 is integrally formed with a camshaft 53 that rotates in synchronization with an engine crankshaft (not shown). When the camshaft 53 rotates, the camshaft 53 rotates relative to the base circle 46a. The cam peak portion 46 b that is raised in this manner presses the roller 52 to swing the arm 47.

  As shown in FIGS. 7 and 8, the lash adjuster 41 is screw-engaged with a nut member 55 inserted into the accommodation hole 54 opened in the lower surface of the arm 47 and a female screw 56 formed on the inner periphery of the nut member 55. An adjustment screw 58 having a male screw 57 on the outer periphery, a return spring 59 incorporated in the nut member 55, and a spring seat 60 fixed to the upper end of the nut member 55.

  As shown in FIG. 8, the nut member 55 is formed in a pipe shape with both ends open, and the female screw 56 is formed over the entire length of the nut member 55. The nut member 55 can be produced by tapping a female screw 56 on the inner periphery of an iron pipe member having a length corresponding to a plurality of nut members 55 and then cutting the pipe member.

  The male screw 57 and the female screw 56 have a sawtooth shape in which the flank angle of the pressure-side flank 61 that receives pressure when a load in the direction of pushing the adjusting screw 58 into the nut member 55 is applied is larger than the flank angle of the play-side flank 62. When the static load in the pushing direction is applied to the adjusting screw 58, rotation of the adjusting screw 58 is prevented by the frictional resistance between the pressure side flank 61, 61 of the male screw 57 and the female screw 56, When a static load in the protruding direction is applied to the adjustment screw 58, the adjustment screw 58 is allowed to rotate by sliding between the play side flank 62, 62 of the male screw 57 and the female screw 56.

  The spring seat 60 is formed in a bottomed cylindrical shape having a cylindrical outer peripheral surface, and is press-fitted into the nut member 55 with an open end facing upward, and the outer peripheral surface of the spring seat 60 and the female screw of the nut member 55 A spiral gap 63 is formed between the two and 56. Further, a notch 64 penetrating in the radial direction is formed at the open end of the spring seat 60. Further, as shown in FIG. 7, the arm 47 is formed with an oil passage hole 65 communicating from the upper surface to the inner bottom surface of the accommodation hole 54. Therefore, the lubricating oil splashed on the arm 47 sequentially passes through the oil passage hole 65 of the arm 47, the notch 64 of the spring seat 60, and the spiral gap 63 between the spring seat 60 and the nut member 55. The lubricating oil introduced into the nut member 55 and lubricated into the nut member 55 lubricates the male screw 57 and the female screw 56. As a material of the spring seat 60, iron, aluminum, resin, or the like can be used.

  As shown in FIG. 8, the return spring 59 has an upper end supported by a spring seat 60 and a lower end that presses an adjustment screw 58 via a spring seat 66, and the adjustment screw 58 is removed from the nut member 55 by the pressing. It is energized in a direction that protrudes downward. The protruding end of the adjusting screw 58 from the nut member 55 presses the upper end of the valve stem 45 (see FIG. 7).

  As in the first embodiment, the lash adjuster 41 is configured such that when the cam crest 46b of the cam 46 pushes up the end of the arm 47 and a load in the pushing direction is applied to the adjusting screw 58, the pressure side flank of the male screw 57 is applied. 61 is received by the pressure side flank 61 of the female screw 56, and the axial position of the adjusting screw 58 with respect to the nut member 55 is fixed. At this time, strictly speaking, a slight slip occurs between the pressure side flank 61, 61 of the male screw 57 and the female screw 56, and the adjustment screw 58 moves in the pushing direction by the sliding, but the cam 46 further rotates to push in the pushing direction. When the load is released, the adjustment screw 58 moves in the protruding direction by the load in the protruding direction applied from the return spring 59 and returns to the original position.

  Since both ends of the nut member 55 are open in the lash adjuster 41, there is nothing that interferes with the tip of the tap when the internal thread 56 on the inner periphery of the nut member 55 is tapped. As a result, the tapping feed can be made faster. In addition, since the nut member 55 has the female thread 56 over the entire length of the nut member 55, by tapping the female thread 56 on the inner periphery of the pipe material having a length corresponding to a plurality of nut members 55, the pipe member is cut, The nut member 55 can be produced. Therefore, this lash adjuster 41 can perform tap processing for a plurality of nut members 55 at a time, and the productivity of the nut members 55 is high.

  Further, since both ends of the nut member 55 are open in the lash adjuster 41, when the lash adjuster 41 is assembled, the adjustment screw 58 is screwed from one end of the nut member 55, and then the return is returned from the other end of the nut member 55. A spring 59 can be inserted. Therefore, it is easy to see the return spring 59 inserted into the nut member 55, and it is easy to check whether the return spring 59 has been inserted without being caught.

  In this embodiment, the spring seat 60 having a cylindrical outer peripheral surface is described as an example as a spring seat for supporting the upper end of the return spring 59. However, in place of the spring seat 60, the spring seat 60 is described in the second embodiment. You may use the spring seat 32 and the retaining ring 39 shown in FIG.

The front view which shows the valve operating apparatus incorporating the lash adjuster of 1st Embodiment of this invention Enlarged sectional view of the lash adjuster shown in FIG. The expanded sectional view which shows the lash adjuster of 2nd Embodiment of this invention Bottom view of the lash adjuster shown in FIG. FIG. 3 is an enlarged sectional view in the vicinity of a spring seat showing a modification of the lash adjuster shown in FIG. FIG. 3 is an enlarged sectional view showing another modification of the lash adjuster shown in FIG. Front view showing a valve gear incorporating a lash adjuster according to a third embodiment of the present invention. Enlarged sectional view of the lash adjuster shown in FIG.

Explanation of symbols

1 lash adjuster 2 cylinder head 7 arm 13 receiving hole 14 nut member 15 female screw 16 male screw 17 adjusting screw 18 return spring 19 spring seat 20 pressure side flank 21 idle side flank 31 lash adjuster 32 spring seat 34 flange portion 35 tool engaging groove 37 Non-slip groove 38 Circumferential groove 39 Retaining ring 41 Rush adjuster 45 Valve stem 46 Cam 47 Arm 54 Housing hole 55 Nut member 56 Female screw 57 Male screw 58 Adjusting screw 59 Return spring 60 Spring seat 61 Pressure side flank 62 Play side flank

Claims (10)

A nut member (14) having an internal thread (15) on the inner periphery, an adjustment screw (17) having an external thread (16) on the outer periphery that engages with the female thread (15) of the nut member (14), and the nut member (14) and a return spring (18) for urging the adjustment screw (17) in a direction protruding from the nut member (14). The male screw (16) and the female screw (15) A sawtooth shape in which the flank angle of the pressure side flank (20) that receives pressure when a load in the direction of pushing the screw (17) into the nut member (14) is applied is larger than the flank angle of the play side flank (21). In the lash adjuster of the valve gear formed in
The nut member (14) is formed into a pipe shape with both ends open, and has the female screw (15) over its entire length.   The lash adjuster according to claim 1, wherein a spring seat (19) having a cylindrical outer peripheral surface is press-fitted into the nut member (14), and the return spring (18) is supported by the spring seat (19).   The lash adjuster according to claim 1, wherein a spring seat (32) having an external thread on the outer periphery is screwed into the nut member (14), and the return spring (18) is supported by the spring seat (32).   The lash adjuster according to claim 3, wherein the spring seat (32) is provided with a flange portion (34) that abuts against an end surface of the nut member (14).   The lash adjuster according to claim 4, wherein a tool engaging groove (35) for rotating the spring seat (32) is provided in the flange portion (34).   The lash adjuster according to claim 4, wherein a non-slip groove (37) is provided on an outer periphery of the flange portion (34).   The lash adjuster according to any one of claims 1 to 6, wherein a material of the spring seat (19) is iron, aluminum, or resin.   2. The return spring (18) according to claim 1, wherein a retaining ring (39) is attached to a circumferential groove (38) formed on the inner periphery of the nut member (14), and the return spring (18) is supported by the retaining ring (39). Rush adjuster.   The nut member (14) is inserted into a receiving hole (13) opened in the upper surface of the cylinder head (2), and the adjustment screw (17) is a protruding end from the nut member (14) at the protruding end of the valve gear. 9. The lash adjuster according to claim 1, wherein the arm (7) is swingably supported.   The nut member (55) is inserted into a receiving hole (54) opened in the lower surface of an arm (47) that swings according to the rotation of the cam (46), and the adjustment screw (58) The lash adjuster according to any one of claims 1 to 8, wherein a valve stem (45) of the valve operating device is pressed by a projecting end from 55).

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