JP2006125289A - Valve spring retainer for internal combustion engine - Google Patents

Abstract

An object of the present invention is to prevent stress from concentrating on a continuous corner portion between a cylindrical portion and a spring receiving flange portion in a spring retainer, and to prevent the inner peripheral edge of the upper end of a valve spring from contacting the continuous corner portion.
An outer diameter of a cylindrical portion of a spring retainer is set to be smaller than an inner diameter of a valve spring, and at least three axial projections in which an inner peripheral surface of an upper end portion of the valve spring is in sliding contact with the outer peripheral surface thereof. The ridges 9 are projected at equal intervals in the circumferential direction, and a concave groove 11 that is recessed in the radial direction is formed at the upper end of the ridge 9, and the upper end thereof is seated on the lower surface of the spring receiving flange portion 6. It is provided so as to be continuous inward from the pressure contact portion of the winding end portion 7a.
[Selection] Figure 2

Description

  The present invention relates to a spring retainer used for a valve operating mechanism in an internal combustion engine, and more particularly to a valve spring retainer that can increase the strength of a spring receiving flange portion to which the upper end of a valve spring is pressed.

  A valve spring retainer (hereinafter abbreviated as a spring retainer) used in a valve mechanism of an internal combustion engine is an upper portion of a cylindrical portion having a tapered hole into which a cotter for fixing a shaft end portion of an engine valve is fitted at the center. In addition, it is common that a spring receiving flange portion with which the upper end of the valve spring is in pressure contact is integrally connected.

Thus, in such a spring retainer, the outer diameter of the cylindrical portion and the inner diameter of the valve spring are substantially equal, and the inner peripheral surface of the upper end portion of the valve spring is in sliding contact with the outer peripheral surface of the cylindrical portion. By guiding them close to each other, the valve spring is prevented from moving in the radial direction perpendicular to the axis (see, for example, Patent Documents 1 and 2).
JP 62-291407 A Japanese Patent Laid-Open No. 3-286106

  In the spring retainer as described above, usually, as shown in an enlarged view in FIG. 8, a corner R is provided at the corner (c) where the cylindrical portion (a) and the spring receiving flange portion (b) are connected, In addition to avoiding stress concentration, chamfering (f) is applied to the inner circumference of the first winding at the upper end of the valve spring (d), that is, the end winding end (e) with the upper end as a flat surface. The inner peripheral edge of the end winding end (e) is prevented from contacting the part (c).

In this case, the corner R needs to be smaller than the width of the chamfer (f).
The reason is that if the corner R is larger than the width of the chamfer (f) as shown by a two-dot chain line, the edge of the chamfer (f) contacts the continuous corner (c), and the portion This is because notch wear occurs in the case.

  Thus, if the corner R of the continuous corner portion of the tube portion and the spring receiving flange portion is made smaller than the chamfering width of the end winding end portion of the valve spring, stress tends to concentrate on the continuous corner portion, In particular, in a spring retainer made of aluminum alloy or the like for the purpose of reducing the weight and having a low strength, the spring receiving flange portion may cause fatigue failure due to repeated loads input from the valve spring.

  In order to prevent this, it is conceivable to increase the rigidity by increasing the vertical dimension of the spring bearing flange, to use a high-strength material, or to apply surface treatment to increase wear resistance. This is not preferable because the weight of the spring retainer is increased, the manufacturing cost is increased, and the opponent attack is increased.

  On the other hand, as described above, in order to avoid the problem that the edge portion of the chamfer (f) is in contact with the continuous corner (c), as shown by a two-dot chain line in FIG. It is also conceivable to form an annular relief groove (g) that is recessed obliquely upward in c).

  However, in this case, the thickness of the continuous corner (c) is reduced, the rigidity is lowered, and stress is concentrated due to the notch effect by the escape groove (g). The spring bearing flange may cause fatigue failure.

  The present invention has been made in view of the above-described problems, and prevents stress from concentrating on the connecting corner between the tube portion and the spring receiving flange, and the upper end of the valve spring at the connecting corner. An object of the present invention is to provide a valve spring retainer for an internal combustion engine in which the strength and rigidity of a spring receiving flange portion can be increased by preventing the inner peripheral edge from coming into contact, and the overall weight can be reduced. Yes.

According to the present invention, the above problem is solved as follows.
(1) A cylinder portion fixed to the shaft end portion of the engine valve and fitted with the upper end portion of the valve spring, and extending outwardly from the upper end of the cylinder portion, and an end winding end portion of the upper end of the valve spring. In the valve spring retainer for an internal combustion engine having a spring receiving flange portion that is in pressure contact, the outer diameter of the cylindrical portion is smaller than the inner diameter of the valve spring, and at least the inner peripheral surface of the upper end portion of the valve spring is in sliding contact with the outer peripheral surface. Three protruding ridges facing in the axial direction are provided at equal intervals in the circumferential direction, and a concave groove that is recessed in the radial direction is formed at the upper end of the ridge, the upper end of which is the spring receiving flange portion. Is provided so as to be continuous inward from the press-contact portion of the end winding end portion.

(2) In the above item (1), three ridges whose outer end surfaces form an arcuate curved surface are provided at equal intervals in the circumferential direction, and the ridges adjacent to each other are connected to each other at the intermediate portion. The planar shape formed by the three ridges is generally a regular triangle by continuing the convex curved surface that continues to the outer peripheral surface.

(3) In the above item (1) or (2), the concave groove has a substantially arc-shaped cross section.

(4) In any one of the above items (1) to (3), the concave groove is formed by applying pressure to the outer peripheral surface of the protrusion to cause plastic deformation.

According to the first aspect of the present invention, the outer diameter of the cylindrical portion is made smaller than the inner diameter of the valve spring, and the protrusion is provided on the outer peripheral surface thereof so that the inner peripheral surface of the upper end of the valve spring is in sliding contact. A gap is formed between the outer peripheral surface of the cylinder portion excluding the inner periphery of the end portion of the end of the valve spring and the inner end of the end portion of the end portion of the end portion of the end of the end portion of the end of the end portion. The periphery does not touch.
On the other hand, since the upper end portion of the protrusion is provided with a groove that is recessed in the radial direction, the inner peripheral edge of the end winding end portion does not contact the protrusion.
Therefore, notch wear is not caused in the continuous corner portion between the tube portion and the spring receiving flange portion, and stress is not concentrated on that portion, and the strength and rigidity of the spring receiving flange portion is increased.
In addition, since a gap is formed between the outer peripheral surface of the cylindrical portion excluding the ridge and the inner peripheral edge of the end winding end portion, a relatively large corner is provided at the continuous corner between the ridge and the spring receiving flange portion. The corner R can be formed with a margin, and the stress is less likely to concentrate on that portion.
Furthermore, the weight of the spring retainer can be reduced by reducing the diameter of the cylindrical portion.

According to invention of Claim 2, since the planar shape of each protrusion has comprised the equilateral triangle, the clearance gap between the outer peripheral surface of the cylinder part except the protrusion and the inner periphery of the end winding end part is. The connecting corner between the cylindrical portion and the spring receiving flange portion is greatly separated from the inner peripheral edge of the end winding end portion.
Therefore, even if the end winding end portion vibrates greatly in the radial direction, there is no possibility that the inner peripheral edge contacts the continuous corner portion.
Moreover, since the larger corner R can be formed in the continuous corner, the strength and rigidity of the portion are further increased.
In addition, the spring retainer is lighter.

  According to the third aspect of the present invention, it is possible to prevent a large stress from being locally applied to the concave groove forming portion of the protrusion.

  According to the fourth aspect of the present invention, since the recessed groove forming portion is work-hardened, the strength of the portion can be increased.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, a first embodiment of the invention will be described with reference to the drawings.
FIG. 1 schematically shows a valve operating mechanism of an internal combustion engine in which a spring retainer according to a first embodiment of the present invention is assembled. An annular groove on an outer peripheral surface of an engine valve (1) is shown in FIG. The spring retainer (3) is fastened via a pair of cotters (2) and (2) having a half-cylindrical shape locked to (1a).

  The spring retainer (3) is formed by, for example, die-forging an aluminum alloy and then performing a T6 treatment (solution aging treatment) based on JIS, and a tapered hole into which the cotter (2) is fitted at the center. On the outer peripheral surface of the upper end portion of the cylindrical portion (5) having (4), a thin spring receiving flange portion (6) extending in the radial direction is integrally connected.

  By retracting the valve spring (7) between the lower surface of the spring bearing flange (6) and the cylinder head (not shown), the engine valve (1) is always urged upward.

  The upper end of the upper end of the valve spring (7), that is, the upper end of the end winding end (7a) that comes into pressure contact with the lower surface of the spring receiving flange (6) is processed into a flat surface and the upper end of the inner peripheral surface thereof The edge is chamfered at an angle of 45 ° (8).

  2 to 4, the outer diameter (D1) of the cylindrical portion (5) of the spring retainer (3) is slightly smaller than the inner diameter (D2) of the valve spring (7), and the cylindrical portion ( On the outer peripheral surface of 5), three ridges (9) with which the inner peripheral surface of the upper end portion of the valve spring (7) is slidably contacted are projected in the axial direction and at equal intervals in the circumferential direction. ing.

  The outer peripheral surface of the three protrusions (9) is in sliding contact with the inner peripheral surface of the upper end of the valve spring (7), so that the upper end of the valve spring (7) moves in the radial direction perpendicular to the axis. Is prevented.

  The upper end of each protrusion (9), that is, slightly below the connecting corner (10) between it and the spring receiving flange (6) is recessed in the radial direction, and the end winding end (7a ) Chamfer (8) is formed with a concave groove (11) having an arcuate cross section larger than the maximum vertical dimension, its inner end surface is continuous with the outer peripheral surface of the cylindrical portion (5), and its upper end is a spring receiver It is continuous with the lower surface of the flange portion (6) slightly inward from the press contact portion of the end winding end portion (7a).

  As shown in FIG. 2, the end portion of the end winding (7a) is provided at the corner of the connecting portion of the cylindrical portion (5) excluding the protruding portion of the protrusion (9) and the spring receiving flange portion (6). The corner R (12), which is larger than the maximum chamfer width of the chamfer (8), is continuous with the lower surface of the spring bearing flange (6) with the upper end inward of the press-contact portion of the end winding end (7a). Is formed.

  The depth of the concave groove (11) is such that the edge portion of the inner end of the chamfer (8) at the end winding end portion (7a) does not come into contact with the vibration of the valve spring (7), for example, 0.1-2. About 0.0 mm is preferable.

  When the spring retainer (3) is formed by die forging, it is preferable that the protrusion (9) is integrally formed at the same time, and the concave groove (11) is cold-cut without being cut. In (or warm), for example, it may be formed by swaging or burnishing with a rolling roller or the like.

  By doing so, the formation part of the protrusion (9) and the concave groove (11) is plastically deformed, and a compressive residual stress is applied and work hardening is performed, so that the wear resistance and strength of the part can be improved. it can.

  As described above, the outer diameter of the cylindrical portion (5) of the spring retainer (3) is made smaller than the inner diameter of the valve spring (7), and the inner peripheral surface of the upper end portion of the valve spring (7) slides on the outer peripheral surface. As shown in FIGS. 2 to 4, when the three projecting ridges (9) are in contact with each other, the outer peripheral surface of the cylindrical portion (5) excluding the ridge (9) and the inner peripheral surface of the valve spring (7) are provided. A gap (13) is formed between them and the edge portion of the end winding end portion (7a) is separated from the outer peripheral surface of the cylindrical portion (5).

  Therefore, as shown in FIG. 2, a corner R (which is larger than the width of the chamfer (8) of the end winding end portion (7a) is formed at the continuous corner portion of the cylindrical portion (5) and the spring receiving flange portion (6). 12) can be formed with a margin, and even if such a large corner R (12) is formed, there is no fear that the edge portion of the chamfer (8) will contact as in the prior art.

  As a result, the strength of the connecting corner between the cylindrical portion (5) and the spring receiving flange portion (6) is increased, and stress is prevented from concentrating on that portion.

In addition, the corner (10) between the ridge (9) and the spring receiving flange (6) is also recessed in the radial direction and the vertical dimension of the chamfer (8) of the end winding end (7a). Since the larger arc-shaped concave groove (11) is formed, even if the edge portion of the chamfer (8) moves in the radial direction by vibration or the like, it does not contact the continuous corner (10). . Moreover, since the concave groove (11) is recessed in the radial direction, stress does not concentrate on the connecting corner (10) between the protrusion (19) and the spring receiving flange portion (6).
Furthermore, the spring retainer (3) can be reduced in weight by making the outer diameter of the cylindrical portion (5) smaller than the inner diameter of the valve spring (7).

  FIG. 5 shows a modified example of the shape of the concave groove (11), and an intermediate portion of the arc-shaped concave groove (11) and a spring slightly inside the press-contact portion of the end winding end portion (7a). By connecting the lower surface of the receiving flange part (6) with a secant line, the continuous corner (10) between the ridge (9) and the spring receiving flange part (6) is formed as an obtuse taper surface (14). is there.

  Even if the groove (11) has such a shape, not only stress is not concentrated on the continuous corner (10), but also the edge portion of the chamfer (8) of the end winding end (7a) is connected to the continuous corner ( 10) is prevented from touching.

6 and 7 show a second embodiment of the present invention.
In this embodiment, the outer diameter (D1) of the cylinder part (5) is made considerably smaller than the inner diameter (D2) of the valve spring (7), a large gap (15) is formed between them, and the cylinder Three ridges (16) slidably in contact with the inner peripheral surface of the upper end of the valve spring (7) are connected to the outer peripheral surface of the portion (5) in the axial direction at equal intervals in the circumferential direction. .

  The outer end surfaces of the ridges (16) form an arcuate curved surface, and the ridges (16) adjacent to each other are continuously connected to each other by a convex curved surface that is tangentially connected to the outer peripheral surface of the cylindrical portion (5). Thus, the planar shape formed by the three ridges (16) is generally an equilateral triangle.

  A concave portion having a generally arcuate cross-section that is largely recessed in the radial direction, as described above, is slightly below the connecting corner (10) between the upper end of each protrusion (16) and the spring bearing flange (6). The groove (17) is formed by forging or the like so that the back end surface thereof is continuous with the outer peripheral surface of the cylindrical portion (5).

  In the same manner as shown in FIG. 5, the concave groove (17) has an arcuate lower half, and the upper half and the lower surface of the spring receiving flange (6) are continuous by a dividing line. Is a tapered surface (18) showing an obtuse angle.

  A corner R (19) having a large radius is provided at the corner of the connecting portion between the cylindrical portion (5) and the spring receiving flange portion (6) excluding the formation portion of the concave groove (17), and the upper end thereof is the end of the end winding. It is provided so as to be continuous with the lower surface of the spring receiving flange portion (6) inward of the pressure contact portion of the portion (7a).

  Also in this embodiment, the same operational effects as those of the first embodiment can be obtained, the cylindrical portion (5) has a considerably small diameter, and the planar shape formed by each protrusion (16) is substantially an equilateral triangle. For this reason, the inner peripheral end of the end winding end portion (7a) is greatly separated from the continuous corner portion, and there is no possibility that the edge portion of the chamfer (8) contacts the portion.

Further, the outer diameter (D1) of the cylindrical portion (5) is considerably smaller than the inner diameter (D2) of the valve spring (7), and a large corner R (19) is formed at the connecting corner, so that The strength of the portion is remarkably increased, and the risk of stress concentration is eliminated.
Furthermore, the spring retainer (3) is significantly reduced in weight by reducing the outer diameter of the cylindrical portion (5).

  When the outer diameter of the cylindrical portion (5) is small, instead of the corner R (19), as shown by a two-dot chain line in FIG. 7, the continuous corner portion is tapered to increase the thickness of the portion, Strength can also be increased.

In the embodiment described above, the spring retainer (3) is applied to the valve spring (7) whose end winding end (7a) is chamfered (8). It can also be applied to valve springs that are not subjected to 8).
Further, three or more protrusions (9) and (16) may be provided.

  The present invention is effective when applied to a relatively soft spring retainer such as the above-described aluminum alloy, but of course can also be applied to an ordinary steel spring retainer.

It is a center vertical front view of the principal part of the valve operating mechanism assembled | attached with the spring retainer of the 1st Embodiment of this invention. Similarly, it is an expanded sectional view of only the spring retainer and valve spring of FIG. FIG. 3 is a cross-sectional plan view taken along line III-III in FIG. 1. It is the IV-IV line crossing top view of FIG. It is a longitudinal cross-sectional view of the principal part which shows the modification of a ditch | groove. It is a cross-sectional top view of the same site | part as FIG. 3 in the spring retainer of the 2nd Embodiment of this invention. Similarly, it is an enlarged central longitudinal sectional front view. It is an expanded sectional view of the principal part which shows the relationship between the conventional spring retainer and a valve spring.

Explanation of symbols

(1) Engine valve
(1a) Annular groove
(2) Cotta
(3) Spring retainer
(4) Taper hole
(5) Tube part
(6) Spring bearing flange
(7) Valve spring
(7a) End winding end
(8) Chamfer
(9) Projections
(10) Contiguous corner
(11) Concave groove
(12) Corner R
(13) Gap
(14) Tapered surface
(15) Clearance
(16) ridge
(17) Groove
(18) Tapered surface
(19) Corner R

Claims (4)

A cylinder portion fixed to the shaft end portion of the engine valve and fitted with the upper end portion of the valve spring, and extending outward from the upper end of the cylinder portion, and the end winding end portion of the upper end of the valve spring is in pressure contact with each other In a valve spring retainer for an internal combustion engine having a spring receiving flange portion,
The outer diameter of the cylindrical portion is smaller than the inner diameter of the valve spring, and at least three axially projecting ridges that are in sliding contact with the inner peripheral surface of the upper end of the valve spring are arranged at equal intervals in the circumferential direction. A protruding groove is provided at the upper end portion of the ridge, and a concave groove is provided in the radial direction. The upper end of the groove is continuous with the lower surface of the spring receiving flange portion inward from the press contact portion of the end winding end portion. A valve spring retainer for an internal combustion engine, which is provided as described above.   Three ridges whose outer end surfaces form an arcuate curved surface are provided at equal intervals in the circumferential direction, and the ridges adjacent to each other are continuously connected by a convex curved surface connected to the outer peripheral surface of the cylindrical portion at the intermediate portion. The valve spring retainer for an internal combustion engine according to claim 1, wherein the planar shape formed by the three protrusions is substantially a regular triangle.   The valve spring retainer for an internal combustion engine according to claim 1 or 2, wherein the concave groove has a substantially arc-shaped cross section. The valve spring retainer for an internal combustion engine according to any one of claims 1 to 3, wherein the concave groove is formed by pressurizing and plastically deforming the outer peripheral surface of the protrusion.

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