JPS6038007Y2 - valve for engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement of an engine valve used as an intake valve or an exhaust valve of an engine.

Conventionally, as shown in FIG. 2, an engine valve a has a valve body C provided at one end of the valve shaft, which is connected to the other end of the valve shaft through a spring retainer e and a split collar f. Usually, a cock groove d is provided, and this cock groove d is formed in an annular shape to engage with an annular protrusion provided on the split collar f.

In such a valve a, there is a risk of breakage in the vicinity B of the connection between the valve body C and the valve stem, which is greatly affected by heat in the vicinity A1 of the cock groove where the strength is weak and stress concentration tends to occur.

In addition, poppet-type, flat-type, etc. valves that open and close the intake or exhaust port of an engine using a camshaft via a rocker arm, etc., reliably follow the contour of the cam and open and close. There is a need,
The allowable rotational speed of this valve mechanism is limited by the weight of the valve mechanism, which is comprised of a valve, a spring retainer, a spring, and the like.

In other words, when the weight of the valve mechanism is large and the inertia force increases,
When the engine speed exceeds the allowable speed of the valve train, the inertial force becomes greater than the tension of the valve spring, and when the valve closes, the valve moves away from (lags) the cam contour, Due to the shift in valve opening/closing timing, it becomes impossible to increase the rotation, and furthermore, the natural frequency becomes low, which may cause abnormal vibration.

In addition, the valve shaft is affected by heat because the valve body facing the combustion chamber of the engine becomes high temperature, and furthermore, frictional heat is generated when sliding on the valve guide, so the valve shaft generally tends to become high temperature.

The present invention has been developed in view of these points, and instead of the conventional cock groove, an annular protrusion with a substantially semicircular cross section is provided near the end of the valve shaft, and the spring retainer is connected to the spring retainer via a split collar having an annular groove. In addition, by providing a spiral groove on the outer periphery of the valve shaft, we provide an engine valve that improves strength and reduces weight, prevents valve breakage accidents, and reduces the allowable rotation speed of the valve mechanism. The purpose is to increase the

The structure of the present invention is a solid valve in which a valve body is integrally connected to one end of the valve shaft, and an annular protrusion having a substantially semicircular cross section is provided near the other end of the valve shaft. The annular protrusion is integrally formed to protrude, the annular protrusion is coupled to a spring retainer via a split collar, and the annular protrusion is engaged with an annular groove provided in the split collar so that its entire surface is surrounded. , a spiral groove is provided on the outer periphery of the valve shaft between the valve body and the annular protrusion.

Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

As shown in FIG. 1, an engine valve 1 has a valve body 3 integrally connected to one end of a valve shaft 2, and an annular protrusion 4 having a substantially semicircular cross section integrally arranged near the other end. Protruding and imposing, valve body 3
A spiral groove 5 is provided on the outer periphery of the valve shaft 2 between the annular protrusion 4 and the annular protrusion 4.

The valve 1 is coupled to the spring retainer 7 by engaging the annular protrusion 4 with an annular R6a provided on the split collar 6 so that its entire surface is surrounded.

The spiral groove 5 of the valve shaft 2 is located within the sliding portion 8 of the valve shaft 2 with respect to the valve guide (the portion defined by line 8a and line 8b), and the valve shaft 2 slides toward the intake port or exhaust port. The spiral groove 5 is prevented from communicating with the port when the port is moved.

As a result, the upper end of the valve shaft 2 is connected to the valve mechanism and is in an atmosphere in contact with lubricating oil, but the lubricating oil and the intake air-fuel mixture or combustion exhaust gas are mixed through the spiral groove 5. Prevented.

Next, when we investigated the temperature distribution of the valve 1 configured as described above, we found that the lowermost peripheral edge 3a of the valve body 3 was 7.
The temperature is about 80°C, the neck 3b of the valve body 3 is about 850°C, and the lower end 2a of the valve shaft 2 is about 840°C.

The temperature of the portion of the valve stem 2 between the valve body 3 and the annular protrusion 4 tends to rise due to the heat transferred from the high-temperature valve body 3 and the frictional heat generated when sliding on the valve guide. However, the lubricating oil flowing into the spiral groove 5 from the upper end of the valve shaft 2 effectively cools the valve shaft 2, so that the respective parts 3a, 3b*2a do not reach high temperatures, and the lubricating oil has a lubricating effect. Therefore, seizure and wear between the valve stem 2 and the valve guide are suppressed.

As mentioned above, the present invention provides an annular protrusion with a substantially semicircular cross section near the end of the valve stem and connects it to the spring retainer via a split collar. It is possible to improve the strength without causing stress concentration as shown in the figure, and it is possible to prevent breakage accidents that occur near the conventional cotter grooves.

In addition, since the strength is improved by forming the annular protrusion, it is possible to reduce the weight of the valve by reducing the diameter of the valve stem and the spiral groove provided on the outer periphery of the valve stem. In addition, by interposing lubricating oil in the spiral groove, it is possible to cool the valve stem and prevent seizure.Also, since it is a spiral groove, it is possible to improve balance and stress distribution. It has moderate practical advantages, such as not causing a decrease in strength.

[Brief explanation of the drawing]

FIG. 1 is a front view showing an embodiment of the engine valve of the present invention, and FIG. 2 is a front view showing a conventional example. 1.7... Valve, 2, 2a... Valve stem, 3... Valve body, 4... Annular protrusion, 5...
...Spiral groove.

Claims (1)

[Scope of utility model registration request] A solid valve in which a valve body is integrally connected to one end of the valve shaft, and an annular protrusion having a substantially semicircular cross section is integrally formed near the other end of the valve shaft. The annular protrusion is coupled to a spring retainer via a split collar, the annular protrusion is engaged with an annular groove provided in the split collar so that its entire surface is surrounded, and the annular protrusion is engaged with a spring retainer through a split collar. An engine valve characterized in that a spiral groove is provided on the outer periphery of the valve shaft between the annular protrusion and the valve shaft.