JP5345075B2 - Rocker arm manufacturing method - Google Patents

Description

  The present invention relates to a rocker arm that swings and drives a valve of an internal combustion engine.

  The rocker arm includes a lash adjuster that is pivotally supported by the rocker shaft and presses the valve, as in the rocker arm of the conventional example 1 (Patent Document 1), and from the rocker shaft to the lash adjuster. Some have oil passage holes for sending oil.

JP-A-6-193411

  Since such a rocker arm has a complicated structure in terms of providing an oil passage hole, it is generally made into a cast article by casting such as the lost wax method.

  However, the cast article by casting has a high manufacturing cost, and the weight is increased because it is necessary to increase the thickness in order to ensure the strength.

  Further, in the rocker arm, as in the rocker arm main body 90 shown in FIG. Provided with a connected portion 92 that is connected to the input member driven by the connecting pin 58 and a lash adjuster 93 that presses the valve 53 at the distal end portion, so that the shaft hole 91 and the connected portion 92 are Some lash adjusters 93 are arranged in a straight line. In the rocker arm main body 90, an oil passage hole 94 for sending oil from the rocker shaft 56 to the lash adjuster 93 bypasses the coupled portion 92 (the coupling pin 58) in an arc shape.

  However, when the oil passage hole 94 bypasses the coupled portion 92 in an arc shape in this way, the oil passage hole 94 extends in length and becomes complicated in shape, making it difficult to transmit hydraulic pressure. As a result, the responsiveness of the lash adjuster 93 may be deteriorated.

  Accordingly, the first object of the present invention is to manufacture a rocker arm having a lash adjuster and an oil passage hole for sending oil to the lash adjuster at low cost and to reduce the weight, and the oil passage hole is connected. A second object is to extend the portion (connecting pin) in an arc shape without detouring.

In order to achieve the first object, a method for manufacturing a rocker arm according to the present invention comprises a rocker arm main body and a lash adjuster attached to the rocker arm main body to press a valve, and the lash adjuster is attached to the rocker arm main body. In a method of manufacturing a rocker arm having a lash adjuster mounting hole, a shaft hole through which a rocker shaft is inserted, and an oil passage hole for sending oil from the rocker shaft to the lash adjuster, the rocker arm body includes A thick part extending in a line for forming the oil passage hole (of course, a line having a thickness, including a bent line here), and a general part other than the thick part The thick wall portion is thicker than a predetermined thickness of the general portion, and the rocker arm body is attached to the following [A] to [D]. And manufacturing,
[A] Leave the thick part on the metal plate thicker than the predetermined thickness of the general part after manufacturing the rocker arm body, and press the part corresponding to the general part of the metal plate to the predetermined thickness. Reduce meat.
[A] The oil passage hole extending linearly (same as above) is formed in the thick part.
[C] The general part is bent into a shape after the production of the rocker arm body.
[D] The lash adjuster mounting hole and the shaft hole are formed in the metal plate.
The lash adjuster is inserted and attached to the lash adjuster attachment hole of the manufactured rocker arm body.

  Although it does not specifically limit as a formation method of the oil passage hole of said [I], A cutting process can be illustrated. Although it does not specifically limit as a bending process of said [c], A press bending process can be illustrated. The method for forming the lash adjuster mounting hole and the shaft hole of [D] is not particularly limited, and examples thereof include cutting.

  In order to achieve the second object, the rocker arm body is formed to include an upper wall and two side walls that are bent from both side edges of the upper wall and extend downward. The thick portion and the oil passage hole are formed from the base end portion to the lengthwise intermediate portion, and the lash adjuster mounting hole is formed at the tip portion of the upper wall that is a part of the general portion. The shaft hole is formed in the base end portion of the side wall which is a part of the side wall, and the input member driven by the cam is connected to the input member driven by the cam in the middle portion in the longitudinal direction of the side wall which is a part of the general part. It is preferable that a connected member to be connected is provided, and the thick portion and the oil passage hole are arranged so as not to bend for the purpose of bypassing the connected member. This is because the thick portion and the oil passage hole can extend without bypassing the connected member in an arc shape.

  Further, it is preferable that the thick part and the oil passage hole are not bent and are made straight (a straight line having a thickness). This is to make the sheet metal processing simpler and improve the responsiveness of the lash adjuster. However, when the lash adjuster mounting holes are formed in the general part so as to be orthogonal to the surface direction of the general part when they are aligned, the direction of the central axis of the plunger of the lash adjuster is the center of the valve. In the case of a large deviation from the axial direction, a holder for attaching the lash adjuster to the lash adjuster attachment hole is provided with a mounting portion inserted into the lash adjuster attachment hole and a cylinder into which the plunger is slidably inserted. It is only necessary to form a shape in which the shape portion is bent and connected so that both central axis directions substantially coincide.

  ADVANTAGE OF THE INVENTION According to this invention, the rocker arm provided with the lash adjuster and the oil passage hole for sending oil to this lash adjuster can be manufactured at low cost, and can be reduced in weight.

It is a perspective view which shows the rocker arm and its peripheral member of Example 1 of this invention. It is a top view which shows the rocker arm of the same Example 1, and its peripheral member. It is side surface sectional drawing which shows the rocker arm of the same Example 1, and its peripheral member. (A) is a top view of the metal plate used for manufacturing a rocker arm main body in Example 1, (α) is a sectional view taken along IV (α) -IV (α) of (A), and (a) is (A). FIG. (B) is a plan view of the same metal plate whose thickness has been reduced by pressing, (β) is a cross-sectional view of (B) IV (β) -IV (β), and (b) is a view of (B). It is a front view. (C) is a plan view when the metal plate is bent, and (c) is a front view of (C). (D) is a top view when a hole and a recessed part are formed in the metal plate, (d) is a front view of (D). (E) is a plan view when a lash adjuster or the like is attached to the manufactured rocker arm body, and (e) is a front view of (E). It is side surface sectional drawing which shows the rocker arm of Example 2 of this invention, and its peripheral member. It is a side view which shows the rocker arm of the prior art example 2.

  1 to 5 includes a rocker arm main body 2 made of sheet metal and a lash adjuster 30 attached to the rocker arm main body 2. The rocker arm body 2 made of sheet metal includes an upper wall 3 and two side walls 4 and 4 that are bent from both side edges of the upper wall 3 and extend downward.

  The width of the upper wall 3 is relatively narrow from the base end portion to the intermediate portion in the longitudinal direction, and the width increases between the intermediate portion in the longitudinal direction and the distal end portion, so that the width is relatively wide at the distal end portion. It has become. In the present embodiment, the upper wall 3 is bent 10 to 30 degrees in the vertical direction at one location in the middle portion in the length direction, and is more proximal than the bent portion 5 with respect to the distal end side 3 a from the bent portion 5. The end side 3b is inclined lower toward the base end.

  With the width of the upper wall 3, the side walls 4 and 4 have a small distance between the side walls from the base end part to the middle part in the length direction, and the distance between the side walls increases between the middle part in the length direction and the tip part. The distance between the side walls is large at the tip. Further, the front end portions of the side walls 4 and 4 are shorter than the front end portion of the upper wall 3, and the front end portion of the upper wall 3 protrudes further forward than the front end portions of the side walls 4 and 4.

  Shaft holes 17 and 17 are provided in the base end portions of the side walls 4 and 4, and the rocker shaft 56 is inserted into the shaft holes 17 and 17 so that the rocker arm 1 is pivotally supported. That is, the rocker arm 1 of this embodiment is a swing arm.

  Connected member mounting holes 18, 18 are provided in the middle portions in the length direction of the side walls 4, 4, and a cylindrical connected member 50 is mounted in the mounting holes 18, 18. The connected member 50 is for establishing a variable valve mechanism described later.

  A lash adjuster mounting hole 13 that is perpendicular to the surface direction of the upper wall 3 is provided through the front end of the upper wall 3 that is wide. A cylindrical lash adjuster 30 that will be described later is attached to the mounting hole 13. . Therefore, the length direction of the lash adjuster 30 is orthogonal to the tip portion of the upper wall 3. In this embodiment, the valve 53 is pressed at the lower end of the lash adjuster 30.

  A thick portion 8 having a predetermined width that extends linearly from the base end portion to the middle portion in the length direction (to the vicinity of the tip end portion) is integrally formed at the center portion in the width direction of the lower surface of the upper wall 3. The thick wall portion 8 is formed with an oil passage hole 9 extending linearly for sending oil to the lash adjuster 30. Since the bent portion 5 of the upper wall 3 is also applied to the middle portion of the thick portion 8 and the oil passage hole 9, the thick portion 8 and the oil passage hole 9 are similarly 10 in the vertical direction at the bent portion 5. Bent to 30 degrees. However, the thick portion 8 and the oil passage hole 9 are arranged so as not to bend for the purpose of bypassing the connected member 50, and the bending of 10 to 30 degrees is given for the purpose described later.

  Here, the thickness of the rocker arm main body 2 will be described. The thickness of the thick portion 8 is, for example, 4.5 mm (may be changed within a range of 4 to 6 mm). The predetermined thickness of the portion 11 (that is, both adjacent portions of the thick portion 8 from the base end portion of the upper wall 3 to the middle portion in the length direction, the distal end portion of the upper wall 3, and the side walls 4, 4) is, for example, 3. 2 mm (may be changed within a range of 2.8 to 3.6 mm, and may be changed depending on a site within the same range). Accordingly, the thick portion 8 protrudes downward by, for example, 1.3 mm from the general portions 11 on both sides thereof. Moreover, the width | variety of the thick part 8 is 4-6 mm, for example.

  The lash adjuster 30 includes a cylindrical holder 31 (also serving as a body in the present embodiment), a plunger 36 slidably inserted into the holder 31, and a plunger 36 retracted into the holder 31. A high pressure oil chamber 37 in which the pressure increases, a low pressure oil chamber 32 that can communicate with the high pressure oil chamber 37 via a check valve 38, and a spring (not shown) that moves the plunger 36 out of the holder 31. It is configured. When the plunger 36 is retracted, the oil in the high pressure oil chamber 37 leaks to the low pressure oil chamber 32 through the clearance between the plunger 36 and the holder 31, and when the plunger 36 advances, the low pressure oil The oil in the chamber 32 flows into the high-pressure oil chamber 37 through the check valve 38. By inserting the holder 31 into the lash adjuster mounting hole 13 at the tip of the upper wall 3, the lash adjuster 30 is attached to the rocker arm body 2, and the tip of the plunger 36 is in contact with the valve 53. The mounting angle of the lash adjuster 30 is such that the direction of the central axis of the plunger 36 (which slightly swings with the rocker arm body 2 swings) substantially coincides with the direction of the central axis of the valve 53.

  The variable valve mechanism is supported by a drive cam 54 and a round cam 55 (or a low lift cam) formed side by side on the camshaft 51 and a rocker shaft 56 that is pivotally supported side by side with the rocker arm 1. An input arm 52 as an input member of the variable valve mechanism, a roller 57 that is rotatably attached to the input arm 52 and pressed by the driving cam 54, and a connecting pin 58 that is slidably inserted into the input arm 52. And a connecting pin 59 inserted into the connected member 50 of the rocker arm 1 and a sliding contact member 40 attached to the upper wall 3 of the rocker arm 1 and slidably contacting the round cam 55. When the connecting pin 58 or 59 that is driven and slid by a pin driving mechanism (not shown) straddles the input arm 52 and the rocker arm 1, the rocker arm 1 is swung together with the input arm 52 by the driving cam 54. When not rocking, the rocker arm 1 does not swing, and unnecessary movement is restricted by the round cam 55 (when the cam is for low lift, it is lifted low). That is, the rocker arm 1 functions as an output arm of the variable valve mechanism.

  A procedure for manufacturing the rocker arm main body 2 shown above by sheet metal will be described in the following [A] to [D]. In the following description, a direction corresponding to the base end / tip direction of the rocker arm body 2 in the plate surface direction of the metal plate 10 is referred to as a base direction, and a direction orthogonal to the base direction is referred to as a left-right direction. The normal direction of the plate surface is referred to as the vertical direction.

[A] Metal plate thinning As shown in FIGS. 4 (A) (α) (a), a metal plate 10 (thickness greater than a predetermined thickness (for example, 3.2 mm) of the general portion 11 after the production of the rocker arm main body ( For example, a thickness of 4.5 mm) is prepared. And as shown to FIG.4 (B) ((beta)) (b), leaving the thick part 8 extended in the base direction for forming the oil passage hole 9 in the left-right direction intermediate part of the metal plate 10, The portions 11a, 11b, and 11c corresponding to the general portion 11 of the metal plate (10) are pressed to reduce the thickness to the predetermined thickness (3.2 mm) (extends in the left-right direction and the base direction). The part corresponding to the general part 11 includes an upper wall base end part to intermediate part forming parts 11a, 11a corresponding to both adjacent parts of the thick part 8 from the base end part of the upper wall 3 to the intermediate part in the length direction, An upper wall tip portion forming portion 11 b corresponding to the tip portion of the upper wall 3 and side wall forming portions 11 c and 11 c corresponding to the side walls 4 and 4 are included.
In addition, the metal plate 10 thicker than the thick part 8 after manufacture is used, and not only the part corresponding to the general part 11 is pressed, but the thick part 8 may be slightly pressed.
Further, the peripheral portion of the metal plate 10 is trimmed so as to obtain the shape after the manufacture of the rocker arm body 2 at the same time as the thinning press processing or by subsequent press processing.

[I] Formation of oil passage hole Then, the oil passage hole 9 extending in the base direction and penetrating in the base direction is formed in the remaining thick portion 8 by cutting or the like. The diameter of the oil passage hole 9 is, for example, 1.5 to 2.5 mm.

[C] Bending of metal plate Next, as shown in FIGS. 5C and 5C, the upper wall base end portion to the intermediate portion forming portions 11a, 11a and the upper wall tip end forming portion 11b are formed by press bending. And the side wall forming parts 11c, 11c are bent so that the side wall forming parts 11c, 11c hang down to form the side walls 4, 4, and the upper wall base end part to the intermediate part forming parts 11a, 11a The middle part in the longitudinal direction of the thick part 8 (including the oil passage hole 9) is bent in the vertical direction to form the upper wall 3 with the bent part 5, thereby adjusting the metal plate 10 to the shape after the production of the rocker arm body. .

[D] Formation of Predetermined Part Next, as shown in FIGS. 5D and 5D, a lash adjuster mounting hole 13 is cut at the front end of the upper wall 3 so as to communicate with the oil passage hole 9. To form. Moreover, the sliding contact member attachment recessed part 14 for attaching the sliding contact member 40 is provided in the upper surface of the intermediate part of the upper wall 3 in the length direction by cutting or the like. Further, the shaft holes 17 and 17 and the connected member mounting holes 18 and 18 are formed through the side walls 4 and 4 by cutting or the like. Further, a communication hole 26 for connecting the oil hole 60 in the rocker shaft 56 and the oil passage hole 9 is provided in the thick wall portion 8 by cutting or the like.

  As shown in FIGS. 5E and 5E, the lash adjuster 30 is attached to the lash adjuster attachment hole 13 with respect to the rocker arm main body 2 manufactured in this way. The sliding contact member 40 is attached to the sliding contact member mounting recess 14. Further, the connected member 50 is attached to the connected member attaching holes 18, 18. Thereby, the to-be-connected member 50 three-dimensionally intersects with the thick portion 8 and the oil passage hole 9. A closing member 27 is attached to the opening at the rear end of the oil passage hole 9. Thus, the rocker arm 1 is completed.

  According to the first embodiment, the rocker arm body 2 provided with the thick wall portion 8 and the oil passage hole 9 (and thus cannot be said to have a simple shape) is manufactured by sheet metal pressing or the like without using casting. Can be kept low. Moreover, although the site | part required for forming the oil passage hole 9 is made into the thick part 8, since the general part 11 other than the thick part 8 can make thickness smaller than the case of casting by the work hardening by press work. The rocker arm body 2 can be reduced in weight. Further, the thick wall portion 8 and the oil passage hole 9 are arranged so as not to bend for the purpose of bypassing the connected member 50, and in particular, the oil passage hole 9 bypasses the connected member 50 in an arc shape (as in Conventional Example 2). Therefore, the responsiveness of the lash adjuster 30 is not deteriorated due to the detour.

  In this embodiment, the upper wall 3 is bent by 10 to 30 degrees in the vertical direction, and the base end side 3b is inclined lower than the bent end 5 as the base end. This is because the shaft hole 17 is provided at a lower portion of the side walls 4 and 4 because of the arrangement of the parts, so that the upper wall 3 is brought close to the oil hole 60 and the communication hole 26. As long as the oil passage hole 9 is bent by 10 to 30 degrees, the responsiveness of the lash adjuster 30 is hardly deteriorated. On the other hand, when the shaft hole 17 can be provided at a high position on the side walls 4 and 4 due to the same arrangement, the upper wall 3 is not bent in the vertical direction (the base end side 3b is inclined). Therefore, in manufacturing the rocker arm main body 2, the upper wall 3 including the thick wall portion 8 and the oil passage hole 9 can be prevented from being bent in the vertical direction. In this case, since the thick portion 8 and the oil passage hole 9 can be aligned without bending, the sheet metal working can be further simplified, and the responsiveness of the lash adjuster can be improved.

  The rocker arm 1 of the second embodiment shown in FIG. 6 is another mode for preventing the upper wall 3 described at the end of the first embodiment from being bent in the vertical direction. Also in the second embodiment, since the shaft hole 17 is provided at a lower portion of the side walls 4 and 4 due to the arrangement of each part of the valve operating mechanism, the base end portion side 3b of the upper wall 3 is inclined to be lower toward the base end. However, the upper wall 3 is not bent in the vertical direction, and therefore the distal end side 3a is on an extension of the proximal end side 3b. That is, in manufacturing the rocker arm body, the upper wall 3 including the thick wall portion 8 and the oil passage hole 9 is not bent in the vertical direction, which is different from the manufacturing method of the first embodiment.

  However, when this is done, when the lash adjuster mounting hole 13 perpendicular to the surface direction of the upper wall 3 is provided at the tip of the upper wall 3, the mounting angle of the lash adjuster 30 changes from that in the first embodiment. The central axis direction of the plunger 36 is greatly deviated from the central axis direction of the valve 53. Therefore, in the second embodiment, the holder 31 of the lash adjuster 30 is formed by bending and connecting the mounting portion 31a inserted into the lash adjuster mounting hole 13 and the cylindrical portion 31b into which the plunger 36 is slidably inserted. By doing so, the central axis direction of the plunger 36 is made to substantially coincide with the central axis direction of the valve 53.

  Also according to the second embodiment, as described at the end of the first embodiment, the thick wall portion 8 and the oil passage hole 9 are not bent, so that the sheet metal processing can be further simplified and the oil passage hole 9 can be straightened. Thus, the responsiveness of the lash adjuster can be improved.

  In addition, this invention is not limited to the structure of the said Example, In the range which does not deviate from the meaning of invention, it can also change and actualize.

DESCRIPTION OF SYMBOLS 1 Rocker arm 2 Rocker arm main body 3 Upper wall 3a Tip part side 3b Base end part side 4 Side wall 5 Bending part 8 Thick part 9 Oil passage hole 10 Metal plate 11 General part 13 Rush adjuster attachment hole 14 Sliding member attachment recessed part 17 Shaft hole 18 Connected member mounting hole 26 Communication hole 27 Closing member 30 Rush adjuster 31 Holder 31a Mounting portion 31b Cylindrical portion 32 Low pressure oil chamber 36 Plunger 37 High pressure oil chamber 38 Check valve 40 Sliding member 50 Connected member 51 Camshaft 52 Input arm 53 Valve 54 Driving cam 55 Round cam 56 Rocker shaft 57 Roller 58 Connecting pin 59 Connecting pin 60 Oil hole 69 Rocker arm

Claims (4)

A lash for attaching the lash adjuster (30) to the rocker arm main body (2), comprising a rocker arm main body (2) and a lash adjuster (30) attached to the rocker arm main body (2) to press the valve (53). An adjuster mounting hole (13), a shaft hole (17) through which the rocker shaft (56) is inserted, and an oil passage hole (9) for sending oil from the rocker shaft (56) to the lash adjuster (30) In the method of manufacturing the rocker arm (1) formed with
The rocker arm body (2) includes a thick portion (8) extending linearly for forming the oil passage hole (9), and a general portion (11) other than the thick portion (8), The thick part (8) is thicker than the predetermined thickness of the general part (11),
The rocker arm body (2) is manufactured by the following [A] to [D],
[A] The general part (11) of the metal plate (10), leaving the thick part (8) on the metal plate (10) thicker than the predetermined thickness of the general part (11) after manufacturing the rocker arm body. The part corresponding to is pressed to reduce the thickness to the predetermined thickness.
[A] The oil passage hole (9) extending linearly is formed in the thick part (8).
[C] The general part (11) is bent into the shape after the production of the rocker arm body.
[D] The lash adjuster mounting hole (13) and the shaft hole (17) are formed in the metal plate (10).
A method for manufacturing a rocker arm, wherein the lash adjuster (30) is inserted and mounted in the lash adjuster mounting hole (13) of the manufactured rocker arm main body (2). The rocker arm body (2) is formed to include an upper wall (3) and two side walls (4, 4) which are bent from both side edges of the upper wall (3) and extend downward.
The thick wall portion (8) and the oil passage hole (9) are formed from the base end portion of the upper wall (3) to the middle portion in the length direction,
Forming the lash adjuster mounting hole (13) at the tip of the upper wall (3) which is a part of the general part (11);
The shaft hole (17) is formed at the base end of the side wall (4, 4) which is a part of the general part (11),
An input member (52) driven by a cam (54) is connected via a connecting pin (58) to an intermediate portion in the longitudinal direction of the side wall (4, 4) which is a part of the general part (11). A connected member (50),
The method for manufacturing a rocker arm according to claim 1, wherein the thick wall portion (8) and the oil passage hole (9) are arranged so as not to bend for the purpose of bypassing the connected member (50).   The method for manufacturing a rocker arm according to claim 1 or 2, wherein the thick part (8) and the oil passage hole (9) are made straight without bending. The lash adjuster mounting hole (13) is formed in the general part (11) so as to be orthogonal to the surface direction of the general part (11),
A holder (31) for attaching the lash adjuster (30) to the lash adjuster attachment hole (13) is attached to an attachment portion (31a) inserted into the lash adjuster attachment hole (13) and the lash adjuster (30). The method for manufacturing a rocker arm according to claim 3, wherein the plunger (36) is formed in a shape that is bent and connected to a cylindrical portion (31b) into which the plunger (36) is slidably inserted.

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