JPH078803Y2 - Engine valve spring - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to the structure of an engine valve spring.

(Prior Art) For example, as shown in FIG. 3, an engine valve mechanism 1 generally includes a valve portion (not shown) corresponding to a valve seat on the engine combustion chamber side, and a valve stem 2 supporting the valve portion. A spring retainer (valve upper seat) 5 fitted and fixed to a stem head portion 2a of the valve stem 2 via a rotatable collet 4, a seat surface portion 6 of the spring retainer 5, an engine body side cylinder head upper surface, And a valve spring 3 that is interposed between the valve spring 3 and the valve spring 3 that normally biases the valve portion in the closing direction.

In order to ensure smooth and reliable operation of the valve operating mechanism of such an engine, the urging force of the valve spring 3 can be constantly and stably ensured so that the cam and the valve are interlocked. It is important to always maintain proper pressure. For that purpose, it is required to reduce the inertial force of the valve train itself and to sufficiently increase the urging force of the valve spring 3.

In order to reduce the weight of the valve train itself, to reduce the inertial force and to effectively make the urging force of the valve spring substantially effective, the above spring retainer 5 is recently made of an aluminum alloy (for example, High strength aluminum alloy)
Attempts are being made to manufacture the product at
(See Japanese Patent No. 4311).

On the other hand, for the valve spring 3, a metal material having high rigidity is selected in order to obtain the elastic coefficient as high as possible.
The valve spring 3 has the above spring retainer 5
The area of the contact surface with the seat surface portion is extremely small. As a result, the amount of wear on the contact surface is large and it is easy to cause substantial fluctuations in the coil length. As a result, the urging force may decrease in some cases. In particular, since the valve spring is generally formed by winding in a coil shape, the magnitude of the reaction force (contact pressure) acting on the contact surface with the spring retainer side seat surface portion 6 is essentially nonuniform. Therefore, the resulting wear is uneven wear, which causes unfavorable problems such as rattling after long-term use. For this reason, for example, as shown in Japanese Utility Model Laid-Open No. Sho 62-93101, a structure in which a portion having a large reaction force is formed on the projecting surface portion from the beginning is also adopted, but this is to prevent wear itself. However, the contact area is reduced in the end, and the wear is promoted, and the fundamental problem is not solved.

In view of such circumstances, recently, in order to increase the fatigue strength of the valve spring contact surface and improve wear resistance,
Shot peening of the end surface of the spring is partially performed.

When shot peening is applied, a certain degree of uneven deformation surface is formed on the material surface by the pressure applied by the impact at the time of shot, while the stress due to the internal strain generated during the deformation is accumulated as residual stress, This has the advantage of improving fatigue strength.

(Problems to be solved by the invention) However, on the other hand, when the contact surface 8 with the spring retainer on the upper end 3a side of the valve spring 3 becomes uneven as shown in FIG. There is a problem that the coefficient of friction with the surface becomes high and the degree of wear on the retainer side becomes severe.

Especially when the spring retainer is made of aluminum alloy for the purpose of reducing the inertial weight as described above,
Especially, that point becomes a problem.

(Means for Solving the Problems) The present invention has been made for the purpose of solving the above-mentioned problems, and it is positioned between the engine body side and the valve side spring retainer to close the valve of the engine. In a valve spring of an engine in which the contact surface with the spring retainer is subjected to shot peening while being urged in the direction, a predetermined recess is provided in the contact surface with the anti-spring retainer subjected to the shot peening processing. It is characterized by being filled with the above-mentioned filling material.

(Operation) In the structure of the valve spring for the engine of the present invention, the contact surface portion with the spring retainer, which has been shot peened as described above, is filled with a predetermined filler such as soft metal so that the contact surface is smooth. Has been converted.

(Effect of the Invention) Therefore, according to the engine valve spring of the present invention, even if an aluminum alloy spring retainer is used, the degree of wear is low and a valve operating mechanism that can secure a stable operating state for a long period of time. Will be able to provide.

(Embodiment) Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings 1 to 4.

The valve spring 3 of the engine of this embodiment is loosely fitted to the valve stem 2a of the intake or exhaust valve 2 of an automobile engine as shown in FIG. 3, and the valve cotter 4 is attached to the upper end of the valve stem 2a. The valve spring retainer is mounted between the seat surface portion 6 and the cylinder head upper surface (not shown). The spring retainer includes an aluminum alloy retainer body 5 having a step portion configured to abut the upper end 3a side of the valve spring 3, and a valve spring contact surface of the aluminum alloy retainer body 5. 5a
And a seat surface portion 6 also made of an aluminum alloy.

The aluminum alloy constituting the retainer body 5 is, for example, a high-strength aluminum alloy having the composition shown in (Table 1) below.

On the other hand, the valve spring 3, which is interposed between the seat surface portion 6 and the engine body side cylinder head upper surface portion of the spring retainer having the above-described configuration, is subjected to shot peening as a whole, for example, to increase fatigue strength. Is formed in this way.

As a result of the shot peening process, fine irregularities similar to those in the conventional art are formed on the surface of the valve spring 3, and naturally the contact surface with the spring retainer side seating surface portion 6 is not the material itself as shown in the figure. It is formed on an uneven rough surface.

However, in the case of the present embodiment, the concave portions 7,7
.. so that the recesses 7, 7 ...
Groove filling material made of soft metal such as Zn alloy 10,10
・ Is filled. As a result, the contact surface 8 with the seat surface portion 6 is smoothed as in the case where the shot peening process is not performed as shown in FIGS. 1 and 2. The filling material is not limited to the case of the soft metal as described above, and for example, a synthetic resin material or paint can be used.

Further, as a method of forming the smooth surface, various methods such as rubbing the filling material 10, 10 ... With respect to the concave groove portions 7, 7 ,.

As the material of the valve spring 3, a steel oil tempered wire having the following composition is selected.

As described above, in the structure of the engine valve spring according to the embodiment of the present invention, the contact surface portion with the spring retainer, which has been shot peened as described above, is filled with a predetermined filling material such as soft metal, The contact surface is smoothed.

Therefore, the wear test data of FIG. 4 (engine rotation 7000rp
As is clear from the comparison data between this example and the conventional example under m), even if a spring retainer made of an aluminum alloy is adopted, it is much worn as compared with the conventional example in which the filler is not filled. Thus, it becomes possible to provide a valve mechanism having a low degree of operation and capable of ensuring a stable operating state for a long period of time.

[Brief description of drawings]

FIG. 1 is a sectional view showing a structure of a main part of a valve spring of an engine according to an embodiment of the present invention, FIG. 2 is an enlarged cross-sectional view of the main part, and FIG. 3 is a valve operating valve of the same. FIG. 4 is a cross-sectional view in the state of being incorporated in the mechanism, FIG. 4 is a graph showing the amount of wear of the valve spring of the engine of the embodiment of the present invention in comparison with the conventional example, and FIG. 5 is a structure of the valve spring of the conventional engine. It is a sectional view of an important section. 1 …… Valve mechanism 2 …… Valve 2a …… Valve stem 3 …… Valve spring 3a …… Upper end 5 …… Spring retainer body 6 …… Seat surface 7 …… Recessed groove 10 …… Filler

Claims (1)

[Scope of utility model registration request] 1. An engine, which is located between an engine body side and a valve side spring retainer and urges a valve of the engine in a closing direction, while a contact surface with the spring retainer is shot peened. The valve spring of the engine, wherein a predetermined filling material is filled in the concave portion of the contact surface with the anti-spring retainer that has been shot peened.