JP2002155710A - Clip for rocker arm - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a clip, capable of locking a pivot part to a top end of a tilt supporting part with no backlash and little metal fatigue. SOLUTION: In this clip, cutouts 56, 60 locked in a pivot part 16 and lash adjustor (tilt supporting part) 30 respectively are provided in a top plate 52 and a bottom plate 53. An opening 61 is formed in a middle range in the cross direction of a connecting plate 54 bent so as to be roughly U-shaped when viewed from a side view, a corner part A on the bottom plate side. The top plate and the bottom plate elastically sandwich a connecting wall 12a on the tilt supporting point side from both side of the thickness direction, and the elastic force of the top plate and the bottom plate strongly locks the cutout of the top plate in the pivot part and presses an end face of the connecting wall toward the inside of the connecting plate, thereby relieving the stress concentration on the corner part. It is thus possible to reduce metal fatigue even for repeated tilt operations of a rocker arm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an end pivot type rocker arm which is tilted by a cam and opens and closes a valve provided on a cylinder head. The present invention relates to a rocker arm clip (hereinafter, referred to as a clip) used for non-separably fitting to an upper end of a support portion.

[0002]

2. Description of the Related Art In such a rocker arm, when a cam rotates in conjunction with an engine crankshaft, the rocker arm tilts with a pivot portion at one longitudinal end as a fulcrum, and a valve stem with the other longitudinal end as a tilting end. Push it to move it up and down. In this case, the pivot portion is supported at the upper end of the tilt support portion so as to be tiltable.

[0003] The clip locks the pivot portion so as not to rattle against the upper end portion of the tilt support portion. The applicant of the present application has a hemispherical structure in which the pivot portion faces upward, Japanese Patent Application No. 2000-135953 discloses a clip which can effectively lock the pivot portion without rattling on the upper end portion of the tilt support portion with respect to the rocker arm having the upper end portion of the tilt support portion having a hemispherical shape of the pivot portion. is suggesting.

[0004] The clip proposed by the present applicant will be described with reference to FIGS. 11 to 13. FIG. 11 is a longitudinal side view of a rocker arm to which the clip is applied, FIG. 12 is a plan view of the rocker arm, and FIG. 13 is an enlarged perspective view showing a relevant portion of each of the clip and the connecting wall of the rocker arm.

In these figures, 10 is a rocker arm, 20 is a cam, 30 is a lash adjuster (tilt support), 40 is a valve, and 50 is a clip.

The clip 50 has an upper plate 52, a lower plate 53, and a connecting plate 54 for connecting the upper plate 52 and the lower plate 53. An opening 61 is formed in a middle area in the width direction and at a corner A on the lower plate 53 side.

The projecting portion B of the rocker arm 10 from the connecting wall 12 a is connected to the opening 61 of the clip 50.
End portion 12e which is projected from the opening die and is rounded to improve the life of the press die.
Of the clip 50 is thereby prevented from rotating.

In the clip 50, the cross-sectional shape of the lower plate 53 at the connecting portion (corner A) of the lower plate 53 with the connecting plate 54 is sharply changed to substantially a right angle in accordance with the shape of the end face corner 12e. It has become.

[0009]

Since such a cross-sectional shape at the corner A is a shape in which a high stress concentration occurs,
When a repeated load of bending and unbending is applied to the connecting plate 54 and the lower plate 53 around the corner A by the repetitive tilting operation of the rocker arm 50, the corner A is subjected to metal fatigue early and the strength is reduced. There is a risk. Therefore, there is room for improvement in the clip 50 provided by the present applicant.

Therefore, according to the present invention, when it is possible to prevent the above-mentioned rattling in the clip, even if the rocker arm repeatedly performs the tilting operation, stress concentration at the corners is reduced, and metal fatigue is reduced. A problem to be solved is to make it possible to eliminate the influence on the life.

[0011]

A clip according to the present invention comprises a body made of sheet metal having one longitudinal end of a pair of opposing side walls connected by a connecting wall, and a bulge formed upward on the connecting wall in a hemispherical shape. When the cam rotates, the pivot portion is tilted with the pivot portion as a fulcrum, and the pivot portion is disposed on the cylinder head in a state where the pivot portion is provided on the cylinder head and the upper end is tiltably supported with respect to the hemispherical tilt support portion. It is applied to an end pivot type rocker arm that opens and closes a valve that is operated.

The clip of the present invention is a clip for a rocker arm used for fitting the pivot portion inseparably to the tilting support portion, and has a substantially "U" shape in side view. A notch locked on the pivot portion of the connecting wall, and a notch locked on the tilt support portion on the lower plate. Further, a connecting plate connecting the upper plate and the lower plate is curved into a substantially “C” shape in a side view, and an opening is formed in a width direction intermediate region and a corner on the lower plate side. The upper plate and the lower plate are elastically sandwiched from both sides in the thickness direction with respect to the connecting wall on the tilting fulcrum side of the rocker arm body, and the upper plate and the lower plate are raised by the elastic force of the upper plate and the lower plate. The notch in the plate locks strongly against the pivot The Rukoto, together with the end face of the connecting wall is pressed against the inner surface of the connecting plate,
The lower corner of the edge of the connecting wall may enter the opening of the connecting plate.

Here, when the band plate is viewed from one side in the drawings attached to the specification, its shape is substantially "⊂", but when viewed from the other side, As described above, the shape becomes substantially U-shaped. Further, the above-mentioned “substantially” in the substantially “U” shape means that the shape is not limited to the “U” shape itself,
When the upper plate and the lower plate face each other with a vertical separation, and the upper plate and the lower plate are connected vertically at their base ends, they are similar or almost similar to the shape of the U-shape of katakana. And all the forms having the function and effect of the present invention regardless of the degree are included.

The expression that the connecting plate connecting the upper plate and the lower plate is curved in a substantially “C” shape in side view means that the connecting plate is not curved at an intermediate portion or curved in the opposite direction. Even if there is some deformation in the part where it is formed, it is a meaning including a shape similar or almost similar to the English alphabet symbol "C" when viewed as a whole, and the effect of the present invention is Any form having any degree is included.

Furthermore, the degree of "strong" in the expression that the notch of the upper plate is "strongly" engaged with the pivot portion by the elastic force of the upper plate and the lower plate is determined by the effect of the present invention. Includes all the strength levels as long as the strength can be exerted regardless of the degree.

Further, the "notch" includes both an open form and a closed form.

In the clip of the present invention, the pivot portion and the tilt support portion are locked in the notches of the upper plate and the lower plate, respectively, and the upper plate and the lower plate are connected to the connecting wall on the tilt fulcrum side of the rocker arm body by the upper plate and the lower plate. On the other hand, since it is elastically sandwiched from both sides in the thickness direction, the notch of the upper plate is strongly locked to the pivot portion by the elastic force of the upper plate and the lower plate. Since the end face of the connecting wall is pressed against the inner surface of the connecting plate by this strong locking, it is possible to effectively prevent rattling between the pivot portion and the tilt support portion of the rocker arm.

In this case, the connecting plate connecting the upper plate and the lower plate is curved into a substantially "C" shape in a side view, and the cross-sectional shape at the corner is changed gradually. Therefore, even if the rocker arm repeatedly tilts and bends the connecting plate and the lower plate around the corner and repeats bending back around the corner, stress concentration does not occur at the corner, and the clip proposed by the present applicant. As described above, it is avoided that metal fatigue occurs early.

As a preferred embodiment of the present invention, the upper plate has a bifurcated protruding piece extending from a base end thereof, and the two protruding pieces are formed so that their opposing gaps are locked by the pivot part. It is extended in the free end direction corresponding to the notch shape, and its free end side is bent obliquely downward so that it can contact the pivot portion.

According to this embodiment, the bifurcated projection of the upper plate is pivoted through the gap, and the bifurcated projection of the lower plate is extended from the hemispherical upper end of the tilting support through the gap. Also, the clip can be locked from the side at the lower position, so that the pivot portion and the tilting support portion can be locked more stably and non-rotatably, and the mounting operation is facilitated.

In a further preferred embodiment of the present invention,
The two protruding pieces have their free ends connected to each other and integrated, and have a bulging portion that abuts or approaches the inner wall surfaces of the pair of opposing side walls of the rocker arm.

According to this embodiment, the clip is prevented from rotating at the free end of the bifurcated protruding piece of the upper plate, which is preferable for preventing the occurrence of rattling.

In a further preferred embodiment of the present invention,
On the free end side of the upper plate, a substantially V-shaped claw that is bent obliquely downward and then obliquely upward is provided.

According to this embodiment, the free end side of the upper plate can be pressed downward by the "V" -shaped claw. In this case, the position of the claw with respect to the tilting fulcrum is the notch of the upper plate. Is located at a position where it can be more strongly locked to the pivot portion, so that rattling between the pivot portion and the tilting support portion of the rocker arm can be more effectively prevented in addition to the pressing of the claw.

In a further preferred embodiment of the present invention,
The distance between the upper plate and the lower plate is set to gradually decrease from the connecting plate side to the free end side.

According to this embodiment, the notch of the upper plate is more strongly locked to the pivot portion by the elastic force of the upper plate and the lower plate, and the notch between the pivot portion and the tilt support portion of the rocker arm is provided. The rattling can be more effectively prevented.

In a further preferred embodiment of the present invention,
After punching from a single metal plate by a press, it is manufactured by being bent into a substantially `` U '' shape in side view, the surface of the punched mother body in the punching direction upstream is outward, Further, the inner surface of the boundary between the upper plate and the lower plate and the connecting plate is compressed by being bent so that the downstream surface is located inside.

When a single metal plate is punched by a press, the surface of the punched base material on the upstream side in the punching direction has a sheared surface, and the surface on the downstream side has a broken surface. Therefore, when the bending process is performed so that the surface on the upstream side in the punching direction is located on the outside and the surface on the downstream side is located on the inside as in this embodiment, the inner surface at the boundary between the upper plate and the lower plate and the connecting plate is formed. Since the rocker arm is in the compressed state, even if the rocker arm repeatedly tilts and bends and bends back at the boundary portion, the fatigue strength at the boundary portion is increased, which can contribute to an improvement in clip life.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below with reference to the embodiments shown in FIGS.

FIG. 1 is a longitudinal sectional side view of the rocker arm, FIG. 2 is a plan view thereof, and FIG. 3 is a partially cutaway perspective view of a body of the rocker arm. 4 to 8 relate to the clip of the present embodiment, FIG. 4 is a plan view thereof, FIG.
6 is a front view, FIG. 7 is a bottom view, and FIG. 8 is a perspective view. In these figures, the same or corresponding parts as those in FIGS. 11 to 13 are denoted by the same reference numerals.

Prior to the detailed description of the clip, the configuration of the rocker arm to which the clip is applied will be described.

1 to 3, 10 is a rocker arm, 20 is a cam, 30 is a lash adjuster (tilt support), 40 is a valve, and 50 is a clip.

The rocker arm 10 is of an end pivot type that is tilted by a cam 20 to open and close a valve 40 provided on a cylinder head.

The rocker arm 10 also has a body 13 made of sheet metal formed by connecting both ends in the longitudinal direction of a pair of opposing side walls 11, 11 facing in parallel with each other by connecting walls 12a, 12b.

The rocker arm 10 is supported by a support shaft 14 erected at a longitudinally intermediate portion of the pair of opposed side walls 11 on the body 13, and a cam 20 is rotatably supported by the support shaft 14 and abuts on the cam 20. Roller 15.

The one connecting wall 12a of the body 13 has an upwardly hemispherical pivot portion 16 formed so as to bulge.

The other connecting wall 12b of the body 13 is
It is a valve engaging portion that comes into contact with zero.

The pivot portion 16 is composed of an upward first hemispherical portion 16a having a large radius of curvature and an upward second hemispherical portion 16b formed near the apex of the first hemispherical portion 16a and having a smaller radius of curvature. Become. In the second hemisphere 16b,
An oil hole 16c for discharging lubricating oil to the roller 15 side is formed.

The lash adjuster 30 includes a pivot portion 1
6 has a hemispherical upper end portion 30a having the same radius of curvature as the first hemispherical portion 16a.

When the upper end portion 30a of the lash adjuster 30 is fitted to the inner surface of the pivot portion 16, the pivot portion 1
6, the upper end 30a of the lash adjuster 30 is in close contact with the first hemisphere 16a, whereby the second hemisphere 16b of the pivot 16 and the upper end 3 of the lash adjuster 30 are moved.
A lubricating oil reservoir 16d is formed in a fitting portion between the lubricating oil and the lubricating oil reservoir 16d.

With this configuration, the body 13 is connected to the pivot 1
When the lubricating oil 6 is pivoted about the tilting fulcrum, the lubricating oil accumulated in the lubricating oil sump 16d increases and decreases in the lubricating oil sump 16d in accordance with the tilting operation.
6 is discharged toward the roller 15 from the oil hole 16c of the second hemispherical portion 16b.

Next, the clip 50 used for the rocker arm 10 will be described with reference to FIGS.

The clip 50 has a band plate 51 having a substantially U-shape in side view.

The band plate 51 is composed of an upper plate 52, a lower plate 53, and a connecting plate 54 connecting these.

The upper plate 52 has bifurcated protruding pieces 55, 55 extending from the base end thereof, and is formed in a circular shape which is locked to the pivot portion 16 of the connecting wall 12a by the opposing distance between the protruding pieces 55, 55. A notch 56 is formed.

At the free end side of each of the projecting pieces 55, 55 on the upper plate 52, a claw 5 having a substantially "V" shape in side view, which bends obliquely downward and then obliquely upward.
7 and 57 are provided, and both claws 57 and 57 can be brought into contact with the pivot portion 16.

The free ends of the two projecting pieces 55, 55 are connected to each other and integrated, and the rocker arm 10
Has bulging portions 58, 58 which are in contact with or close to the inner wall surfaces of the pair of opposed side walls 11, 11.

The size of the notch 56 is set to a size that exposes the oil hole 16 c of the pivot portion 16 while being locked to the pivot portion 16.

The circular portion of the notch 56 in a plan view is closed at the free end portions of the both protruding pieces 55, 55. However, the free end portions are separated to open the notches 55, 55 in a plan view. It may be substantially circular.

The lower plate 52 has two protruding pieces 59, 59 extending from the base end thereof.

The opposed gap between the two projecting pieces 59, 59 is formed as a notch 60 which is locked at a position lower than the hemispherical upper end 30 a of the lash adjuster 30.

An opening 61 is provided at a corner A of the lower plate 52 in the widthwise intermediate region thereof.

The distance between the upper plate 52 and the lower plate 53 is set to gradually decrease from the connecting plate 54 side to the free end side.

The connecting plate 54 is curved into a substantially "C" shape in a side view, and the cross section around the corner A at the connecting portion between the lower plate 52 and the connecting plate 54 has a shape that gradually changes. ing.

In the case of the clip 50 having the above-described configuration, the upper plate 52 and the lower plate 53 are elastically sandwiched from both sides in the thickness direction with respect to the connecting wall 12a on the tilting fulcrum side of the rocker arm body 13, and are connected to the upper plate 52. The notch 56 of the upper plate 52 is strongly locked to the pivot portion 16 by the elastic force with the lower plate 53.

By this locking, the end face of the connecting wall 12a is pressed against the inner surface of the connecting plate 54, whereby
The lower corner 12d of the distal end edge 12c of the connecting wall 12a whose both end surfaces are cut obliquely enters the opening 61 of the connecting plate 54. In this case, the end surface of the connecting wall 12a is pressed against the inner surface of the connecting plate 54 and the connecting wall 12a
Since both end faces are cut obliquely, the lower corner portion 12 d enters the opening 61 of the connecting plate 54 even if the connecting plate 54 is curved in a substantially “C” shape in side view. Can be.

A method of manufacturing the clip 50 having the above-described structure will be described with reference to FIG.

First, a single metal plate 62 shown in FIG. 9A is pressed to punch out a clip base 63 shown in FIG. 9B. Then, as shown in FIG. 9C, the clip base 63 is bent into a substantially “U” shape in side view. By this processing, the clip base 63 becomes the clip 50, the bent portion 64 becomes the connecting plate 54, and both sides thereof become the upper plate 52 and the lower plate 53.

In this case, as shown by enlarging the broken-line circle portion D in FIG.
4, since the surface 65 on the upstream side in the punching direction is located on the outside and the surface 66 on the downstream side is located on the inside, the boundary between the bent portion 64 and both sides thereof, that is, the connecting plate 54 and the upper plate on both sides thereof Boundary part 6 between 52 and lower plate 53
The surface (inner surface) on the downstream side of 7, 67 is in a compressed state.

Next, in the bent clip base member 63, the bent portions 68 of the upper plate 52, which become the claws 57, 57 on the free ends of the two projecting pieces 55, 55, are once bent obliquely downward. To bend diagonally upward,
The surface 69 abutting on the pivot portion 16 is a surface on the downstream side in the punching direction.

However, in the case of press punching, FIG.
In (c), as shown by enlarging the dashed circle portion E, a portion from the upstream surface in the punching direction to a predetermined depth becomes a shear surface 70 by pressing, and a surface from the upstream to a downstream surface becomes a fracture surface 71.

For convenience of explanation, both surfaces 70 and 71 are indicated by hatching in different directions, and the boundaries are indicated by broken lines.

Moreover, since the fracture surface 71 is subjected to a tensile stress depending on the bending direction, cracks (cracks) are easily generated, and measures for preventing the cracks have been required until now. In the case of the present embodiment, the fractured surface 71 is pressed again by press working, and the fractured surface 71 is pressed by a press to crush the fractured surface to improve the surface roughness. The cracks are hardly generated even when a tensile stress is generated by bending the character.

It should be noted that the present invention is not limited to the above-described embodiment, and various modifications and applications are possible.

(1) Rocker arm 10 of the above embodiment
Is not limited to the length in the embodiment. For example, FIG.
The clip of each of the above-described embodiments can be used for a rocker arm as indicated by 0. Note that FIG.
Parts corresponding to those in FIG. 1 are denoted by the same reference numerals.

(4) The clip 50 of the above embodiment is
It is made of metal, but it may be made of resin. In this case, a heat-resistant resin material in which the upper plate and the lower plate have the bent shape and can have elasticity is selected.

[0067]

As described above, according to the clip of the present invention, the notch of the upper plate is strongly locked to the pivot portion by the elastic force of the upper plate and the lower plate, and the end face of the connecting wall is connected. Since it is pressed against the inner surface of the plate, it is possible to effectively prevent rattling between the pivot portion and the tilt support portion of the rocker arm. And since the lower edge of the connecting wall is inserted into the opening of the connecting plate, the connecting plate and the lower plate do not need to be bent at a right angle at the corner of the lower plate, and the bending angle is increased. You can now.

As a result, in the case of the clip of the present invention, even if the rocker arm is repeatedly tilted to repeatedly bend and return to the connecting plate and the lower plate around the corner, stress concentration on the corner is greatly increased. As a result, the corner can be prevented from being metal fatigued at an early stage, and its life can be extended.

In addition, this can hardly be disengaged by the tilting operation of the rocker arm to be used, and can contribute to the stabilization of the operation of the rocker arm when the engine speed is increased, for example.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view of a rocker arm to which a clip according to an embodiment of the present invention is applied.

FIG. 2 is a plan view of the rocker arm of FIG. 1;

FIG. 3 is a partially broken perspective view of a body of the rocker arm of FIG. 1;

FIG. 4 is a plan view of the clip of FIG. 1;

FIG. 5 is a side view of the clip of FIG. 1;

FIG. 6 is a front view of the clip of FIG. 1;

FIG. 7 is a bottom view of the clip of FIG. 1;

FIG. 8 is a perspective view of the clip of FIG. 1;

FIG. 9 is a diagram for explaining a manufacturing process of the clip of FIG. 1;

10 is a perspective view of another rocker arm to which the clip of FIG. 1 is applied.

FIG. 11 is a perspective view of a rocker arm to which a conventional clip is applied.

FIG. 12 is a plan view of a rocker arm to which the clip of FIG. 11 is applied;

FIG. 13 is an enlarged perspective view showing an essential part of each of the connecting walls of the clip and the rocker arm of FIG. 11;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Rocker arm 11 Opposite side wall 12a, 12b Connecting wall 13 Body 14 Support shaft 15 Roller 16 Pivot part 20 Cam 30 Rush adjuster 30a Upper end of lash adjuster 40 Valve 50 Clip 51 Strip plate 52 Upper plate 53 Lower plate 54 Connecting plate 55, 55 Bifurcated protruding piece of upper plate 56 Notch (opposed gap of bifurcated protruding piece of upper plate) 57, 57 Claw 59, 59 Bifurcated protruding piece of lower plate 60 Notch (opposing gap of bifurcated protruding piece of lower plate)

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) B21D 28/26 B21D 28/26

Claims (6)

[Claims] 1. A cylinder head comprising: a body made of a sheet metal formed by connecting one end in a longitudinal direction of a pair of opposed side walls with a connecting wall; and a pivot portion formed on the connecting wall to bulge upward in a hemispherical shape. The end pivot type which tilts with its pivot part as a fulcrum when the cam rotates while the upper end is tiltably supported with respect to the hemispherical tilt support part, and opens and closes a valve arranged on the cylinder head A rocker arm clip used to fit the pivot part to the rocker arm in a non-separable manner with respect to the tilt support part, comprising a strip formed in a substantially U-shape in side view, The upper plate is provided with a notch which is locked to the pivot portion of the connecting wall, and the lower plate is provided with a notch which is locked to the tilting support portion. With lower plate The connecting plate to be connected is curved substantially in the shape of a letter “C” in a side view, and an opening is provided in an intermediate region in the width direction and at a corner on the lower plate side, and the upper plate and The lower plate is elastically sandwiched from both sides in the thickness direction with respect to the connecting wall on the tilting fulcrum side of the rocker arm body, so that the notch of the upper plate is strong against the pivot portion due to the elastic force of the upper plate and the lower plate. By being locked, the end face of the connecting wall is pressed against the inner surface of the connecting plate, and the lower corner of the end edge of the connecting wall enters the opening of the connecting plate. And a rocker arm clip. 2. The clip for a rocker arm according to claim 1, wherein the upper plate has a bifurcated protruding piece extending from a base end thereof.
The two protruding pieces are extended in the free end direction in such a manner that their opposing gaps correspond to the circular notch shape locked in the pivot portion, and the free side thereof is bent obliquely downward so as to contact the pivot portion. A clip for a rocker arm that can be contacted. 3. The rocker arm clip according to claim 2, wherein the two protruding pieces have their free ends connected to each other and integrated with each other, and abut against the inner wall surfaces of a pair of opposing side walls of the rocker arm. A clip for a rocker arm, having a bulging portion which is in contact with or close to the clip. 4. The clip for a rocker arm according to claim 1, wherein the upper plate has a substantially “V” shape in a side view in which the upper plate once bends obliquely downward and then obliquely upwards. A clip for a rocker arm, wherein a clip is provided. 5. The rocker arm clip according to claim 1, wherein a distance between the upper plate and the lower plate is set to be gradually smaller from the connecting plate side to the free end side. A rocker arm clip characterized by the following. 6. The rocker arm clip according to claim 1, wherein the clip is punched out of a single metal plate by a press, and then bent into a substantially U-shape in a side view. The surface of the punched parent body on the upstream side in the punching direction is bent outward so that the surface on the downstream side is located on the inner side, so that the upper plate and the lower plate and the connecting plate are connected to each other. A clip for a rocker arm, wherein an inner surface of a boundary portion is in a compressed state.