JP6053395B2 - Rush adjuster - Google Patents

Description

  The present invention relates to a lash adjuster that is provided in a cylinder head and functions as a rocking fulcrum of a rocker arm that operates an intake valve or an exhaust valve of an internal combustion engine, and particularly relates to a hydraulic lash adjuster that operates by being supplied with pressurized oil. Is.

  As a hydraulic lash adjuster, for example, there is a “hydraulic lash adjuster and manufacturing method thereof” disclosed in Patent Document 1 below. In this lash adjuster, the plunger part and the plunger cap part are configured as a single continuous member made of the same material, so that oil in the reservoir chamber can be prevented from leaking to the outside even when the engine is stopped for a long period of time. (Front page of Patent Document 1 below).

JP-A-6-173622

  However, according to the lash adjuster of Patent Document 1, the plunger portion and the plunger cap portion configured as one member have a cylindrical shape that is slidably fitted into the main body. Therefore, there is a possibility that the plunger portion and the plunger cap portion rotate within the main body. Since the main body also has a cylindrical shape, a cylindrical pocket is also formed in the cylinder head to which the lash adjuster is assembled. Therefore, the entire lash adjuster assembled to the cylinder head may also rotate within this pocket.

  For this reason, for example, depending on the inclination of the parked vehicle and the type of the engine, the lash adjuster assembled to the cylinder head may be inclined with respect to the direction of gravity. In such a case, depending on the rotational position of the main body, the plunger portion, and the plunger cap portion, a through hole formed in the plunger cap portion (a hole through which oil is introduced into the plunger cap portion from the outside through the oil introduction hole) is in the direction of gravity. It is also assumed that it faces downward.

  When the through hole in the plunger cap part is located below the oil level that fills the lash adjuster after the engine is stopped, the oil in the lash adjuster leaks outside through the through hole in the plunger cap part. Probability is high. For this reason, when the oil in the high pressure chamber also escapes and the plunger portion reaches a so-called “bottomed state”, abnormal noise is caused when the engine is started (Patent Document 1; paragraphs 0002 and 0003).

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a lash adjuster that can prevent the generation of abnormal noise at the time of starting an internal combustion engine due to air mixing caused by oil leakage from the high-pressure chamber. And

In order to achieve the above object, a lash adjuster (10) according to claim 1 is provided in a cylinder head (60) and operates a rocker arm (70) for operating an intake valve or an exhaust valve of an internal combustion engine. ) And a through hole (11c) having a bottom (12) at one end and communicating with an oil passage (63) in a cylinder head (60) through which pressurized oil flows. ) Having a cylindrical wall (11) on the peripheral wall, and a cylindrical shape slidably received in the body (11), the peripheral wall being added to be able to communicate with the through hole (11c) of the body (11). It has a pressure oil introduction hole (21e), has a reservoir chamber (21c) into which pressurized oil flows through the introduction hole (21e), and has a pressure oil discharge hole (21a) on one end side. A pivot (22) that is formed and serves as a rocking fulcrum of the rocker arm (70), and a communication passage (21d) through which pressurized oil in the reservoir chamber (21c) can flow out is formed at the other end. A plunger (21) having a partition wall (26) in which a high-pressure chamber (11b) is defined between the bottom (12) of the body (11) when the communication path (21d) is closed; and a plunger (21) When the pressurized oil that is accommodated in the high pressure chamber (11b) and closes the opening of the communication passage (21d) of the plunger (21) and flows into the reservoir chamber (21c) reaches a predetermined pressure, the opening is opened. A valve mechanism (40) that opens and allows pressurized oil to flow into the high-pressure chamber (11b), and the pivot mechanism (22) of the plunger (21) is pushed together with the valve mechanism (40) in a direction protruding from the body (11). A spring (48) that urges the nanger (21) to bring the pivot (22) into contact with the rocker arm (70), and the through-hole (11c) is formed in the peripheral wall of the body (11). A pin insertion hole (11e) into which the short shaft pin (51) can be inserted is formed on the opening (11a) side of the peripheral wall with respect to the position of the plunger, and the plunger (21) is formed on the peripheral wall of the plunger (21). The insertion tip (51a) of the pin (51) that extends linearly in the sliding direction of the pin and is inserted into the pin insertion hole (11e) can be locked, determines the protrusion limit of the pivot (22) , and The groove bottom (21k) is inclined so that the depth gradually increases from one end (21j) that determines the protrusion limit of the pivot (22) toward the other end (21i) extending in the direction of the pivot (22). The keyway (21h) is shaped The cylinder head (60) has a cylindrical hole (61) in which the body (11) can be slidably inserted, and communicates with the cylindrical hole (61) than the outer diameter of the pin (51). A long groove (62) that is slightly wide and extends radially outward of the cylindrical hole (61) is formed, and the pin (51) is inserted into the pin insertion hole (11e) and is inserted into the key groove (21h). When the lash adjuster (10) into which the insertion tip (51a) is inserted is assembled into the cylindrical hole (61) of the cylinder head (60), the pin (51) protruding from the body (11) is projected. The technical feature is that the end (51b) is received in the long groove (62) of the cylinder head (60).

A lash adjuster (10) according to claim 2 of the claims is provided on the cylinder head (60), and is a swing fulcrum of a rocker arm (70) for operating an intake valve or an exhaust valve of an internal combustion engine. The lash adjuster functioning as a through-hole (11c) having a bottom (12) at one end and communicating with an oil flow path (63) in a cylinder head (60) through which pressurized oil flows. Cylindrical body (11) and cylindrical oil-slidably accommodated in body (11), and a pressurized oil introduction hole that can communicate with the through hole (11c) of body (11) on the peripheral wall (21e), and has a reservoir chamber (21c) into which pressurized oil flows through the introduction hole (21e) on the inner side, and a discharge hole (21a) for pressurized oil is formed on one end side of the reservoir chamber (21c). A communication path (21d) having a pivot (22) that serves as a pivot point of the arm (70) and allowing the pressurized oil in the reservoir chamber (21c) to flow out is formed at the other end, and this communication path (21d ) Is closed, a plunger (21) having a partition wall (26) in which a high pressure chamber (11b) is defined between the bottom portion (12) of the body (11) and the high pressure chamber of the plunger (21). (11b), the opening of the communication passage (21d) of the plunger (21) is closed, and when the pressurized oil flowing into the reservoir chamber (21c) reaches a predetermined pressure, the opening is opened and the opening is opened. A valve mechanism (40) for flowing pressurized oil into the high pressure chamber (11b), and a plunger (21) together with the valve mechanism (40) in a direction in which the pivot (22) of the plunger (21) protrudes from the body (11). And a spring (48) for bringing the pivot (22) into contact with the rocker arm (70). The peripheral wall of the body (11) has a peripheral wall more than the position of the through hole (11c). A pin insertion hole (11e) into which a short shaft pin (51) can be inserted is formed on the opening (11a) side of the plunger (21), and the peripheral wall of the plunger (21) has a line in the sliding direction of the plunger (21). The insertion tip (51a) of the pin (51) inserted into the pin insertion hole (11e) can be locked to determine the projection limit of the pivot (22) and the projection of the pivot (22). A key groove (21h) in which the groove bottom (21k) is inclined so that the depth gradually decreases from one end side (21j) that determines the limit toward the other end side (21i) extending in the direction of the pivot (22). Formed with the syringin The dahead (60) has a cylindrical hole (61) in which the body (11) can be slidably inserted, and a cylinder that is communicated with the cylindrical hole (61) and slightly wider than the outer diameter of the pin (51). A long groove (62) extending outward in the radial direction of the hole (61) is formed, and the pin (51) is inserted into the pin insertion hole (11e) and the insertion tip (51a) is inserted into the key groove (21h). When the lash adjuster (10) in which is inserted is assembled into the cylindrical hole (61) of the cylinder head (60), the protruding rear end (51b) of the pin (51) protruding from the body (11) It is technically characterized by being accommodated in the long groove (62) of the cylinder head (60) .

  Furthermore, the lash adjuster according to claim 3 of the claim is the lash adjuster according to claim 1 or 2, wherein the plunger (21) receives pressurized oil through the introduction hole (21e). The separator chamber (21b) that flows first is provided upstream of the reservoir chamber (21c), and the circumferential groove (28) extends over the entire circumference of the outer peripheral wall (28) on the other end side of the introduction hole (21e). 21f) is formed, the circumferential groove (21f) has a return hole (21g) communicating with the reservoir chamber (21c), and has a cylindrical shape with a taper that decreases in diameter toward the one end (31a). The one end (31a) faces the one end of the plunger (21) and the other end (31b) is closer to the reservoir chamber than the introduction hole (21e) of the plunger (21). 23) is accommodated in the separator chamber (21b) so as to be fitted in a liquid-tight manner, and the pressurized oil flowing in from the introduction hole (21e) is supplied to the one end (31a) by the outer peripheral wall (32) of the taper. A separator (31) that guides the pressurized oil flowing inward from one end (31a) to the reservoir chamber (21c) via the other end (31b), and stops the operation of the internal combustion engine. When oil stays in the separator (31) or the reservoir chamber (21c), the oil level is positioned below the gravity direction below the introduction hole (21e) and the return hole (21g). Further, the present invention is characterized in that the formation position of the pin insertion hole (11e) is set.

In the invention of claim 1, when the lash adjuster (10) is assembled into the cylindrical hole (61) of the cylinder head (60), it is inserted into the pin insertion hole (11e) and inserted into the key groove (21h) (51a). The protruding rear end (51b) of the pin (51) into which is inserted is accommodated in the long groove (62) of the cylinder head (60). As a result, even when the lash adjuster (10) is assembled to the cylindrical hole (61), there is a pin (51) that engages between the cylinder head (60) and the lash adjuster (10). Therefore, the lash adjuster (10) is locked to the cylinder head (60) via the pin (51), and the rotation of the lash adjuster (10) in the cylindrical hole (61) is restricted. In addition, since there is a pin (51) that engages between the body (11) and the plunger (21) of the lash adjuster (10), the plunger (21) is attached to the body via the pin (51). Locked by (11), the rotation of the plunger (21) in the body (11) is restricted. That is, since the pin (51) engages the three of the cylinder head (60), the plunger (21), and the body (11), their relative rotation is restricted. For this reason, the introduction hole (21e) capable of communicating with the oil flow path (63) and the through hole (11c) in the cylinder head (60) is formed in the separator (31) or the reservoir chamber (21c) by the operation stop of the internal combustion engine. By forming the pin insertion hole (11e) so as to be located above the liquid level of the oil that has stopped, the oil that has stopped in the separator (31) or the reservoir chamber (21c) can be introduced into the introduction hole. (21e) to prevent leakage to the outside. Therefore, it is possible to prevent the generation of abnormal noise at the start of the internal combustion engine due to air mixing caused by oil loss from the high pressure chamber (11b). Further, the groove bottom (21k) of the key groove (21h) gradually increases in depth from one end side (21j) that determines the protrusion limit of the pivot (22) toward the other end side (21i) extending in the direction of the pivot (22). Inclined to increase the height. Thus, in the position of the plunger (21) at the protrusion limit of the pivot (22), that is, in the state where the plunger (21) protrudes most from the body (11), the insertion tip (51a) of the pin (51) is moved to the keyway ( By fixing the pin (51) at a position in contact with the groove bottom (21k) of 21h), the pin (51) is fixed at the shallowest position of the key groove (21h). For this reason, if the plunger (21) moves in the opposite direction, that is, the direction in which the plunger (21) is inserted into the body (11), the depth of the key groove (21h) increases. In this direction, the pin (51) The insertion tip (51a) does not come into contact with the groove bottom (21k) of the key groove (21h). Therefore, it is possible to facilitate the setting of the fixed position of the pin (51) and to prevent the movement of the plunger (21) in the insertion direction due to the contact between the pin (51) and the groove bottom (21k). it can.

In the invention of claim 2, when the lash adjuster (10) is assembled to the cylindrical hole (61) of the cylinder head (60) , the lash adjuster (10) is inserted into the pin insertion hole (11e) and inserted into the key groove (21h) (51a). The protruding rear end (51b) of the pin (51) into which is inserted is accommodated in the long groove (62) of the cylinder head (60). As a result, even when the lash adjuster (10) is assembled to the cylindrical hole (61), there is a pin (51) that engages between the cylinder head (60) and the lash adjuster (10). Therefore, the lash adjuster (10) is locked to the cylinder head (60) via the pin (51), and the rotation of the lash adjuster (10) in the cylindrical hole (61) is restricted. In addition, since there is a pin (51) that engages between the body (11) and the plunger (21) of the lash adjuster (10), the plunger (21) is attached to the body via the pin (51). Locked by (11), the rotation of the plunger (21) in the body (11) is restricted. That is, since the pin (51) engages the three of the cylinder head (60), the plunger (21), and the body (11), their relative rotation is restricted. For this reason, the introduction hole (21e) capable of communicating with the oil flow path (63) and the through hole (11c) in the cylinder head (60) is formed in the separator (31) or the reservoir chamber (21c) by the operation stop of the internal combustion engine. By forming the pin insertion hole (11e) so as to be located above the liquid level of the oil that has stopped, the oil that has stopped in the separator (31) or the reservoir chamber (21c) can be introduced into the introduction hole. (21e) to prevent leakage to the outside. Therefore, it is possible to prevent the generation of abnormal noise at the start of the internal combustion engine due to air mixing caused by oil loss from the high pressure chamber (11b). Further, the groove bottom (21k) of the key groove (21h) gradually increases in depth from one end side (21j) that determines the protrusion limit of the pivot (22) toward the other end side (21i) extending in the direction of the pivot (22). It is inclined so that the depth decreases (the depth gradually increases from the other end side (21i) toward the one end side (21j)).

  In the invention of claim 3, when the oil is stopped in the separator (31) or the reservoir chamber (21c) due to the stop of the operation of the internal combustion engine, the liquid level of the oil becomes the introduction hole (21e) and the return hole (21g). The position where the pin insertion hole (11e) is formed is set so as to be positioned below the gravitational direction. As a result, since the introduction hole (21e) and the return hole (21g) are located above the oil level in the direction of gravity, the oil stopped in the separator (31) or the reservoir chamber (21c) is introduced. Leakage to the outside through the hole (21e) is prevented. Therefore, it is possible to prevent the generation of abnormal noise at the start of the internal combustion engine due to air mixing caused by oil loss from the high pressure chamber (11b).

It is sectional drawing which shows the structure of the lash adjuster which concerns on one Embodiment of this invention. It is explanatory drawing which shows the state which assembled | attached the lash adjuster of this embodiment to the cylinder head of a horizontally opposed engine. It is the arrow line view which looked at a part of cylinder head 60 corresponding to the range of the dashed-dotted line shown in FIG. 2 from III direction. It is a fragmentary sectional view which shows the keyway of the plunger which comprises the lash adjuster of this embodiment. It is explanatory drawing which shows the liquid level etc. of the oil which stops on the lash adjuster assembled | attached to the cylinder head shown in FIG.

  Hereinafter, embodiments of the lash adjuster of the present invention will be described with reference to the drawings. First, the configuration and the like of the lash adjuster 10 according to the present embodiment will be described with reference to FIGS. FIG. 1 is a cross-sectional view of the lash adjuster 10 that appears when the lash adjuster 10 is cut in the axial direction. FIG. 2 is an explanatory diagram showing a state in which the lash adjuster 10 is assembled to the cylinder head 60 of the horizontally opposed engine. FIG. 3 shows an arrow view of a part of the cylinder head 60 corresponding to the range of the one-dot chain line shown in FIG. 2 and 3, the Z-axis arrow direction of the illustrated coordinate axis is the upper side in the gravity direction (hereinafter referred to as “anti-gravity direction”).

  As shown in FIG. 1, the lash adjuster 10 mainly includes a body 11, a plunger 21, a separator 31, and a valve mechanism 40. As shown in FIG. 2, the lash adjuster 10 is assembled in a mounting hole 61 of a cylinder head 60 of a horizontally opposed engine (internal combustion engine), and functions as a rocking fulcrum of a rocker arm 70 that operates an intake valve of the engine. In this example, when the camshaft rotates and the cam 80 pushes and moves the rocker arm 70, a load is applied to both the valve lift mechanism 90 of the intake valve and the lash adjuster 10.

  As shown in FIG. 3, the mounting hole 61 of the cylinder head 60 is located in the anti-gravity direction (Z-axis arrow direction) of the oil gallery 63, and the bottom 12 side of the assembled lash adjuster 10 is in the gravity direction (Z-axis). It is formed obliquely so as to face the direction of the opposite arrow. In addition, a long groove 62 is formed in the opening of the mounting hole 61 so as to extend in the direction of gravity from the lowermost part of the inner peripheral wall thereof. The long groove 62 has a groove width slightly wider than an axial diameter of the pin 51 described later, and a groove length shorter than the axial length of the pin 51 and between 1/3 and 1/2 of the axial length of the pin 51. Respectively.

  The body 11 is made of, for example, case-hardened steel, and is formed in a bottomed cylindrical shape having a bottom 12 at one end and an opening 11a at the other end. The inner peripheral diameter of the body 11 is set slightly larger than the outer peripheral diameter of the plunger 21 so that the plunger 21 can slide on the inner peripheral wall 13 forming the opening 11a.

  An oil hole 11 c is formed in the peripheral wall of the body 11 at a position where it can communicate with the oil gallery 63 in the cylinder head 60 when assembled to the cylinder head 60. The oil hole 11c is a through hole for taking in the pressurized oil flowing through the oil gallery 63 into the body 11, and the inner peripheral wall 13 has an annular recess 11d communicating with the oil hole 11c. The annular recess 11 d is a circumferential groove for guiding the pressurized oil to the introduction hole 21 e of the plunger 21. The annular recess 11 d has a width of the plunger 21 so that the pressurized oil can be introduced regardless of the movement position of the plunger 21. It is determined by the movable range.

  A pin insertion hole 11e is formed on the opening 11a side of the annular recess 11d. The pin insertion hole 11 e is a hole into which the pin 51 is inserted when the lash adjuster 10 is assembled to the cylinder head 60. This pin 51 is formed in a short shaft shape, and its tip 51a is inserted into the pin insertion hole 11e until it is inserted into the key groove 21h of the plunger 21 (shown in the direction of the left arrow of the pin 51). The outline of the pin 51 by a two-dot chain line). Further, the rear end 51 b of the pin 51 is accommodated in the long groove 62 of the cylinder head 60 when the lash adjuster 10 is assembled to the cylinder head 60. Thus, as will be described later, the movement of the plunger 21 in the protruding direction is restricted in cooperation with the key groove 21 h of the plunger 21, and the lash adjuster 10 is operated in cooperation with the long groove 62 of the cylinder head 60. Rotation inside the mounting hole 61 is prevented.

  At the end of the inner peripheral wall 13 from the annular recess 11 d toward the bottom 12, an annular taper groove 16 whose diameter increases as it approaches the bottom 12 is formed, and beyond that, a high pressure with a smaller diameter than the inner peripheral wall 13 is formed. A chamber wall 14 is formed and connected to the bottom surface 12a. That is, a step portion 15 is formed between the inner peripheral wall 13 and the high-pressure chamber wall 14, and movement of the plunger 21 in the insertion direction is restricted by the step portion 15.

  As will be described later, the high pressure chamber wall 14 is a wall body that partitions and forms the high pressure chamber 11b together with the partition wall 26, the discharge portion 27, the ball 43, the bottom portion 12, and the inner peripheral wall 13 of the plunger 21. A valve mechanism 40 and a plunger spring 48 are accommodated in the high pressure chamber 11b.

  The plunger 21 has a cylindrical shape that is slidably accommodated in the body 11, and has a pivot 22 on one end side and a partition wall 26 and a discharge portion 27 on the other end side. That is, the outer peripheral diameter of the plunger 21 is set slightly smaller than the inner peripheral diameter of the body 11, and the separator chamber 21b, the reservoir chamber 21c, and the communication passage 21d are respectively provided from one end side to the other end side. Is formed. The plunger 21 is made of, for example, case-hardened steel, like the body 11.

  The pivot 22 is a support portion (a floating fulcrum of the rocker arm) that comes into contact with one end side of the rocker arm 70, and has a discharge hole 21a at the top and is formed in a substantially dome shape. The discharge hole 21a communicates with the separator chamber 21b in the plunger 21, and allows the pressurized oil filled in the separator chamber 21b to be discharged. The pivot 22 is formed in a substantially dome shape after a later-described separator 31 is press-fitted and fixed in the separator chamber 21b.

  The separator chamber 21 b that houses the separator 31 is a chamber formed by the separator chamber wall 23, and pressurized oil flows first. The separator chamber wall 23 is formed with an introduction hole 21e for introducing pressurized oil, and this introduction hole 21e communicates with the annular recess 11d of the body 11 described above in the movable range of the plunger 21 inserted into the body 11. It is provided in a possible position. Thereby, the pressurized oil flowing from the oil hole 11c of the body 11 can be introduced into the separator chamber 21b via the annular recess 11d.

  The reservoir chamber 21c that communicates with the separator chamber 21b is a chamber formed by the reservoir chamber wall 24, and stores oil that has flowed in through the separator 31 of the separator chamber 21b. The inner diameter of the reservoir chamber 21c is substantially the same as the inner diameter of the separator 31, and is set smaller than the inner diameter of the separator chamber 21b. That is, a step portion 25 is provided between the separator chamber wall 23 forming the separator chamber 21b and the reservoir chamber wall 24 forming the reservoir chamber 21c. The step portion 25 determines the fixing position of the separator 31 when the separator 31 is press-fitted and fixed in the separator chamber 21b.

  A partition wall 26 connected to the entire circumference of the reservoir chamber wall 24 is formed on the side opposite to the reservoir chamber wall 24 with respect to the step portion 25. The partition wall 26 is a disk-shaped plate wall in which a communication path 21d with a reduced diameter is opened in the center, and is connected to a discharge portion 27 that forms the communication path 21d. The discharge portion 27 is a thick cylindrical portion that allows the pressurized oil filled in the reservoir chamber 21c to be discharged to the high pressure chamber 11b, and a sheet 27a is formed at the end. As will be described later, the seat 27a functions as a valve seat on which a ball 43 constituting the valve mechanism 40 can be seated.

  A return hole 21 g is formed in the reservoir chamber wall 24. The return hole 21g is provided at a position where it can communicate with a circumferential groove 21f formed on the entire circumference of the outer peripheral wall 28, and is located in the vicinity of the step portion 25 in this embodiment. The circumferential groove 21 f formed in the outer peripheral wall 28 is provided at a position where it does not communicate with the annular recess 11 d of the body 11 in the movable range of the plunger 21.

  The outer peripheral wall 28 is formed with a key groove 21h in addition to the peripheral groove 21f. This key groove 21 h is a groove in which the tip 51 a of the pin 51 inserted into the pin insertion hole 11 e of the body 11 enters within the movable range of the plunger 21 and restricts the movement of the plunger 21 in the protruding direction. The length of the groove is set to be approximately the stroke length of the plunger 21. In the present embodiment, the key groove 21h is provided at a position substantially opposite to the introduction hole 21e described above.

  The separator 31 is formed of a thin wall, for example, a cold-rolled steel plate, having a taper that decreases in diameter toward the one end 31a, and is formed in a cylindrical shape. The outer diameter of the other end portion 31b without the taper is set to be slightly larger than the inner diameter of the separator chamber 21b, and the total length is set to be slightly shorter than the axial length of the separator chamber 21b. The width of the other end portion 31b without the taper is such that the position where the introduction hole 21e of the plunger 21 is not blocked in the state where the separator 31 is assembled to the separator chamber 21b, that is, the boundary with the taper is larger than the formation position of the introduction hole 21e. The size is set on the stepped portion 25 side. The inner diameter of the other end 31b is set to be approximately the same as the inner diameter of the reservoir chamber 21c of the plunger 21. In the present embodiment, the surface of the separator 31 is plated with a copper sulfide bath or the like as a carbon-proof treatment, and the entire surface including the outer peripheral wall 32 and the inner peripheral wall 33 is plated with copper.

  The separator 31 is assembled before the pivot 22 is formed on the plunger 21. That is, before the pivot is formed into a dome shape, the separator 31 is inserted into the separator chamber 21b from the one end side of the plunger 21 that opens with the same diameter as the inner diameter of the separator chamber 21b from the other end portion 31b, and the other end portion 31b. The separator 31 is press-fitted until it contacts the step portion 25 (or just before the contact). Since the outer diameter of the other end 31b is set to be slightly larger than the inner diameter of the separator chamber 21b, the other end 31b is liquid-tightly fitted to the separator chamber wall 23 by such press-fitting and fixing. .

  The plunger 21 assembled with the separator 31 is pressed or drawn into a dome shape at one end that opens to the same diameter as the inner diameter of the separator chamber 21b, and is completed through each process of carburizing, quenching, and tempering. Carburizing, quenching, and tempering are for increasing the hardness of the surface of the plunger 21 from the inside, thereby improving both the wear resistance and toughness of the plunger 21. In addition, since the separator 31 in the plunger 21 is carburized on the surface thereof, it is not carburized and cracks and cracks do not occur.

  The lash adjuster 10 is assembled to the cylinder head 60 so that the pivot 22 faces obliquely upward (antigravity direction) (see FIG. 2). For this reason, by providing such a separator 31 in the separator chamber 21 b of the plunger 21, the pressurized oil that has flowed from the introduction hole 21 e of the plunger 21 is once upward, that is, that of the pivot 22 by the tapered outer peripheral wall 32. After being guided in the direction (the direction of the one end 31a of the separator 31), it is guided from the one end 31a to the other end 31b, that is, the reservoir chamber 21c through the inside of the separator 31. Thereby, even if air is mixed in the pressurized oil supplied from the oil hole 11c, most of the air lighter than the oil is directed from the discharge hole 21a of the pivot 22 to the plunger 21 when moving in the direction of the pivot 22. Discharged outside. For this reason, air is prevented from flowing into the reservoir chamber 21c through the separator 31 together with the pressurized oil.

  In addition, since the separator 31 is subjected to a carbon-proof treatment, cracks and cracks due to carburizing, quenching, and tempering do not occur. Therefore, as shown in FIG. 2, in the state where the pivot 22 of the lash adjuster 10 is assembled to the cylinder head 60 so as to face obliquely upward (antigravity direction), the oil accumulated in the plunger 21 decreases and the separator 31 Is functioning as an oil reservoir, it is possible to prevent leakage into the separator chamber 21b through cracks or cracks.

  The valve mechanism 40 is a valve device that performs control to introduce pressurized oil filled in the reservoir chamber 21 c of the plunger 21 into the high-pressure chamber 11 b from the discharge portion 27, and includes a retainer 41, a ball 43, and a ball spring 45.

  The retainer 41 holds the ball 43 and the ball spring 45 on the other end side of the plunger 21 so that the ball 43 that is a valve body can be urged toward the seat 27a that is a valve seat by a ball spring 45. The retainer 41 has an opening 41a around the ball 43 so that the oil introduced from the discharge portion 27 passes through the ball 43 and smoothly fills the high-pressure chamber 11b. A communication hole 41b is also formed in a portion that receives the ball 43 away from the communication hole 41b.

  The ball spring 45 is a compression coil spring that urges the ball 43 in the direction of the seat 27 a of the discharge unit 27. It is held by the retainer 41. The urging force (spring pressure) by the ball spring 45 is set to a predetermined pressure.

  The retainer 41 is pressed to the other end side of the plunger 21 by the other end side of the plunger spring 48 whose one end side contacts the bottom surface 12a. As a result, the plunger 21 urged in the protruding direction together with the retainer 41 protrudes from the opening 11 a of the body 11 to a position where movement is restricted by the key groove 21 h and the pin 51 described above.

  Further, in a state where the oil pressure in the reservoir chamber 21 c is less than a predetermined pressure and the ball 43 is seated on the seat 27 a, the communication path 21 d of the discharge portion 27 is closed by the ball 43, so In the bottom 12 direction, the high pressure chamber 11b is defined by the partition wall 26, the discharge portion 27, the ball 43, the bottom surface 12a (bottom portion 12), the inner peripheral wall 13 and the high pressure chamber wall 14. FIG. 1 shows this state.

  Next, the structure of the key groove 21h formed in the outer peripheral wall 28 of the plunger 21 will be described with reference to FIG. FIG. 4 shows a partial cross-sectional view of the plunger 21 around the keyway 21h shown in FIG. It should be noted that the separator 31 and the body 11 are omitted in FIG. 4 for convenience of drawing representation. Also refer to FIG. 5 as appropriate.

  As described above, the key groove 21h is a long groove into which the tip 51a of the pin 51 inserted through the pin insertion hole 11e is inserted, and its length is set slightly larger than the stroke length of the plunger 21. That is, the distance from the one end side 21j to the other end side 21i of the key groove 21h is set to be larger than the stroke length of the range in which the plunger 21 is movable.

  Further, the key groove 21h is given a gradient to the groove bottom 21k so that the depth of the key groove 21h is deeper at the other end 21i than at the one end 21j. That is, as shown in FIG. 4A, the depth is gradually increased from one end side 21j toward the other end side 21i at a gradient angle θ with respect to the central axis of the plunger 21 (see FIG. 4A). The one-dot chain line in the middle is a line parallel to the central axis of the plunger 21). As a result, as shown in FIG. 4B, the tip 51a of the pin 51 inserted into the key groove 21h comes into contact with one end side 21j of the key groove 21h, so that the plunger 21 is locked and its protruding direction. The key groove 21h has the smallest depth at the position where the movement of the key is restricted. On the other hand, in the vicinity of the other end side 21i where the partition wall 26 of the plunger 21 abuts on the step portion 15 of the body 11 and the movement of the plunger 21 in the insertion direction is restricted, as shown in FIG. The depth of the key groove 21h is deeper than the one end side 21j. In this case, the tip 51a of the pin 51 is not in contact with the other end 21i, and a gap is formed between them.

  The gradient angle θ of the groove bottom 21k is preferably as small as possible, and is set to, for example, 0.1 ° to 2.0 °.

  For this reason, in a state in which the plunger 21 protrudes most from the body 11 (see FIGS. 4B and 5B), the tip 51a of the pin 51 is brought into contact with the groove bottom 21k of the key groove 21h, and the position By fixing the pin 51, the pin 51 is uniformly fixed at the position where the depth of the key groove 21h is the shallowest. Therefore, even if the plunger 21 moves in the insertion direction of the body 11 (see FIGS. 4C and 5A), the depth of the key groove 21h increases. 51a does not contact the groove bottom 21k. Therefore, compared with the case where the groove bottom 21k is formed in parallel to the central axis of the plunger 21 without giving such a gradient to the groove bottom 21k, the fixing position of the pin 51 can be set easily and with high accuracy uniformly. It becomes possible. Further, the movement of the plunger 21 in the insertion direction due to the contact between the pin 51 and the groove bottom 21k does not occur.

  Note that the gradient of the groove bottom 21k formed in the key groove 21h may be given in the reverse direction. That is, the gradient may be applied to the groove bottom 21k so that the key groove 21h is deeper at the one end 21j than at the other end 21i. In this case, the depth of the key groove 21h is the deepest at the position where the tip 51a of the pin 51 inserted into the key groove 21h contacts the one end side 21j of the key groove 21h. In the vicinity of the other end side 21i where the partition wall 26 abuts and the movement of the plunger 21 in the insertion direction is restricted, the key groove 21h is shallower than the one end side 21j.

  As shown in FIG. 2, when the lash adjuster 10 configured as described above is assembled to the cylinder head 60 of the horizontally opposed engine, the lash adjuster 10 operates as follows as a rocking fulcrum of the rocker arm 70.

  For example, when there is a gap between the pivot 22 of the plunger 21 and the rocker arm 70, the plunger 21 biased by the plunger spring 48 moves in the protruding direction, and the pivot 22 fills the gap with the rocker arm 70. . That is, when the plunger 21 is moved by the urging force of the plunger spring 48, basically, the high pressure chamber 11b acts on the negative pressure, so that the valve mechanism 40 is opened to pressurize from the reservoir chamber 21c to the high pressure chamber 11b. Oil flows in.

  On the other hand, when a load is applied to the pivot 22 by the rocker arm 70 and the plunger 21 is pressed in the insertion direction, the partition wall 26 that defines the high-pressure chamber 11b moves as the plunger 21 moves in the insertion direction. The volume of the high pressure chamber 11b decreases and the oil pressure that fills the high pressure chamber 11b increases. Thus, when the oil pressure in the high pressure chamber 11b becomes equal to or higher than the pressure obtained by subtracting the spring pressure of the ball spring 45 from the oil pressure in the reservoir chamber 21c, the oil of the pressurized oil that closes and fills the high pressure chamber 11b. The position of the plunger 21 is held by pressure to resist pressing of the rocker arm 70.

  Since the cylinder head 60 and the lash adjuster 10 have a pin 51 that engages with the cylinder head 60 and the lash adjuster 10, the lash adjuster 10 is locked to the cylinder head 60 via the pin 51 and the rotation of the lash adjuster 10 in the mounting hole 61 is restricted. Is done. Since the pin 51 also engages with the body 11 and the plunger 21 of the lash adjuster 10, the plunger 21 is locked to the body 11 via the pin 51 and the rotation of the plunger 21 in the body 11 is restricted. . That is, since the pin 51 engages with the three members of the cylinder head 60, the plunger 21, and the body 11, their relative rotation is restricted, and the lash adjuster 10 can be prevented from rotating.

  Further, as shown in FIG. 5, the pin 51 prevents the lash adjuster 10 from rotating so that the introduction hole 21e and the return hole 21g of the lash adjuster 10 assembled to the cylinder head 60 are located on the uppermost side in the antigravity direction. Is set to FIG. 5 is an explanatory diagram showing the oil level and the like of the oil retained on the lash adjuster 10 assembled to the cylinder head 60. FIG. 5A shows the plunger 21 at the minimum protrusion (maximum insertion), and FIG. 5B shows the plunger 21 at the maximum protrusion (minimum insertion).

  For this reason, even when the oil is stopped in the lash adjuster 10 (more precisely, the separator 31, the reservoir chamber 21c, and the high pressure chamber 11b) due to the stop of the engine operation, Since the introduction hole 21e and the return hole 21g are located on the upper side (antigravity direction) with respect to β, it is possible to prevent the oil in the lash adjuster 10 from leaking outside through these holes 21e and 21g. Become. Therefore, it is possible to prevent the generation of abnormal noise at the time of starting the engine due to air mixing caused by oil loss in the high pressure chamber 11b.

  As described above, according to the lash adjuster 10 according to the present embodiment, when the lash adjuster 10 is assembled into the mounting hole 61 of the cylinder head 60, the tip 51a is inserted into the key groove 21h through the pin insertion hole 11e. The rear end 51 b of the pin 51 is accommodated in the long groove 62 of the cylinder head 60. As a result, even when the lash adjuster 10 is assembled in the cylindrical mounting hole 61, the pin 51 that engages the cylinder head 60 and the lash adjuster 10 exists between the cylinder head 60 and the lash adjuster 10. Thus, the lash adjuster 10 is locked to the cylinder head 60 and the rotation of the lash adjuster 10 in the mounting hole 61 is restricted. In addition, since there is a pin 51 that engages between the body 11 and the plunger 21 of the lash adjuster 10, the plunger 21 is locked to the body 11 via the pin 51, and the plunger 21 in the body 11. Rotation is regulated. That is, since the pin 51 engages with the cylinder head 60, the plunger 21 and the body 11, their relative rotation is restricted. Therefore, the introduction hole 21e that can communicate with the oil gallery 63 and the oil hole 11c in the cylinder head 60 and the return hole 21g are the liquid level α of the oil that is retained in the separator 31 or the reservoir chamber 21c due to the engine stoppage. By forming the pin insertion hole 11e so as to be located on the upper side in the gravity direction than β, the oil retained in the separator 31 or the reservoir chamber 21c leaks to the outside through the introduction hole 21e and the return hole 21g. To prevent that. Therefore, it is possible to prevent the generation of abnormal noise at the time of starting the engine due to air mixing caused by oil loss in the high pressure chamber 11b.

  Further, in the lash adjuster 10 according to the present embodiment, the separator 31 is gradually moved from the one end side 21j that determines the projection limit of the pivot 22 toward the other end side 21i that extends in the direction of the pivot 22 by the groove bottom 21k of the key groove 21h. Inclined to increase depth. Thereby, the position of the plunger 21 at the protrusion limit of the pivot 22, that is, the position where the tip 51a of the pin 51 is brought into contact with the groove bottom 21k of the key groove 21h in the state where the plunger 21 protrudes most from the body 11. By fixing the pin 51, the pin 51 is fixed at the shallowest position of the keyway 21h. For this reason, when the plunger 21 moves in the direction in which the plunger 21 is inserted into the body 11, the depth of the key groove 21h increases. In this direction, the tip 51a of the pin 51 contacts the groove bottom 21k of the key groove 21h. There is nothing. Therefore, it is possible to facilitate the setting of the fixed position of the pin 51 and to prevent the movement of the plunger 21 in the insertion direction due to the contact between the pin 51 and the groove bottom 21k from occurring.

  In the above-described embodiment, the example in which the lash adjuster 10 is applied to the rocker arm 70 that operates the intake valve has been described. However, even if the lash adjuster 10 is applied to the rocker arm that operates the exhaust valve, the same operation as described above. And can get the effect.

  In the above-described embodiment, the example in which the lash adjuster 10 is assembled to the cylinder head of the horizontally opposed engine has been described. However, any reciprocating engine can be applied to a V-type engine, an in-line engine, or the like.

DESCRIPTION OF SYMBOLS 10 ... Rush adjuster 11 ... Body 11a ... Opening part 11b ... High pressure chamber 11c ... Oil hole (through-hole)
11e ... Pin insertion hole 12 ... Bottom 21 ... Plunger 21a ... Discharge hole 21b ... Separator chamber 21c ... Reservoir chamber 21d ... Communication passage 21e ... Introduction hole 21f ... Circumferential groove 21g ... Return hole 21h ... Key groove 21i ... Other end 21j ... One end side 21k ... groove bottom 22 ... pivot 26 ... partition wall 27 ... discharge part 28 ... outer peripheral wall 31 ... separator 31a ... one end part 31b ... other end part 32 ... outer peripheral wall 40 ... valve mechanism 48 ... plunger spring (spring)
51 ... pin 51a ... tip (insertion tip)
51b ... rear end (protruding rear end)
60 ... Cylinder head 61 ... Mounting hole (cylindrical hole)
62 ... long groove 63 ... oil gallery (oil passage)
70 ... Rocker arm

Claims (3)

A lash adjuster that is provided in the cylinder head and functions as a rocking fulcrum of a rocker arm that operates an intake valve or an exhaust valve of an internal combustion engine,
A cylindrical body having a through-hole in the peripheral wall, which has a bottom on one end side and communicates with an oil flow path in a cylinder head through which pressurized oil flows;
The cylinder is slidably accommodated in the body, and has a pressure oil introduction hole that can communicate with the through hole of the body on the peripheral wall, and the pressure oil flows into the inside through the introduction hole. There is a reservoir chamber, a pressure oil discharge hole is formed on one end side, a pivot that serves as a rocking fulcrum of the rocker arm, and a communication passage through which the pressure oil in the reservoir chamber can flow out is provided on the other end side. A plunger having a partition wall that is formed and a high-pressure chamber is defined between the bottom portion of the body when the communication path is closed;
When the pressurized oil contained in the high-pressure chamber of the plunger and closing the opening of the communication passage of the plunger and flowing into the reservoir chamber reaches a predetermined pressure, the opening is opened and pressurized oil is supplied to the high-pressure chamber. A valve mechanism to flow in,
A spring that urges the plunger together with a valve mechanism in a direction in which the pivot of the plunger protrudes from the body and abuts the pivot against the rocker arm,
The peripheral wall of the body is formed with a pin insertion hole through which a short shaft pin can be inserted on the opening side of the peripheral wall from the position of the through hole. The peripheral wall of the plunger has a sliding direction of the plunger. The other end extending in the direction of the pivot from one end side that determines the protrusion limit of the pivot and that can lock the insertion tip of the pin that extends linearly and is inserted into the pin insertion hole. A key groove having a groove bottom inclined so as to gradually increase in depth toward the side is formed, and the cylinder head communicates with a cylindrical hole that can be inserted by sliding the body in sliding contact with the cylindrical hole. A long groove that is slightly wider than the outer diameter of the pin and extends radially outward of the cylindrical hole is formed,
When assembling the lash adjuster in which the pin is inserted into the pin insertion hole and the insertion tip is inserted into the key groove into the cylindrical hole of the cylinder head, the protruding rear end of the pin protruding from the body is The lash adjuster is housed in a long groove of the cylinder head. A lash adjuster that is provided in the cylinder head and functions as a rocking fulcrum of a rocker arm that operates an intake valve or an exhaust valve of an internal combustion engine,
A cylindrical body having a through-hole in the peripheral wall, which has a bottom on one end side and communicates with an oil flow path in a cylinder head through which pressurized oil flows;
The cylinder is slidably accommodated in the body, and has a pressure oil introduction hole that can communicate with the through hole of the body on the peripheral wall, and the pressure oil flows into the inside through the introduction hole. There is a reservoir chamber, a pressure oil discharge hole is formed on one end side, a pivot that serves as a rocking fulcrum of the rocker arm, and a communication passage through which the pressure oil in the reservoir chamber can flow out is provided on the other end side. A plunger having a partition wall that is formed and a high-pressure chamber is defined between the bottom portion of the body when the communication path is closed;
When the pressurized oil contained in the high-pressure chamber of the plunger and closing the opening of the communication passage of the plunger and flowing into the reservoir chamber reaches a predetermined pressure, the opening is opened and pressurized oil is supplied to the high-pressure chamber. A valve mechanism to flow in,
A spring that urges the plunger together with a valve mechanism in a direction in which the pivot of the plunger protrudes from the body and abuts the pivot against the rocker arm,
The peripheral wall of the body is formed with a pin insertion hole through which a short shaft pin can be inserted on the opening side of the peripheral wall from the position of the through hole. The peripheral wall of the plunger has a sliding direction of the plunger. The other end extending in the direction of the pivot from one end side that determines the protrusion limit of the pivot and that can lock the insertion tip of the pin that extends linearly and is inserted into the pin insertion hole. A key groove having an inclined groove bottom is formed so that the depth gradually decreases toward the side, and the cylinder head communicates with a cylindrical hole that can be inserted by sliding the body in sliding contact with the cylindrical hole. A long groove that is slightly wider than the outer diameter of the pin and extends radially outward of the cylindrical hole is formed,
When assembling the lash adjuster in which the pin is inserted into the pin insertion hole and the insertion tip is inserted into the key groove into the cylindrical hole of the cylinder head, the protruding rear end of the pin protruding from the body is The lash adjuster is housed in a long groove of the cylinder head. The plunger has a separator chamber into which pressurized oil first flows in via the introduction hole upstream from the reservoir chamber, and also surrounds the entire circumference of the outer peripheral wall on the other end side from the introduction hole. A groove is formed and has a return hole communicating with the reservoir chamber in the circumferential groove;
An inner peripheral wall closer to the reservoir chamber than the introduction hole of the plunger, the one end being directed to the one end side of the plunger and the other end being directed to the one end side of the plunger Pressurized oil, which is accommodated in the separator chamber so as to fit in a liquid-tight manner, is guided in the direction of one end by the outer peripheral wall of the taper and flows inwardly from one end. Including a separator that leads to the reservoir chamber through the other end,
When the oil is stopped in the separator or the reservoir chamber due to the operation stop of the internal combustion engine, the oil level is positioned below the introduction hole and the return hole in the gravity direction. The lash adjuster according to claim 1 or 2, wherein a formation position of the insertion hole is set.

Images