JPH0329524Y2 - - Google Patents

Description

[Detailed Description of the Invention] "Industrial Application Field" The present invention relates to a four-valve cylinder head for an internal combustion engine, and more particularly to a guide structure for a valve pusher of a valve.

``Prior Art'' A four-valve cylinder head is provided with a pair of intake valves and a pair of exhaust valves, which are operated by each rocker arm, arranged side by side. Each valve pusher fitting is interposed so as to be slidable in the direction of movement. 3 and 4 show the guide structure of the valve pusher fittings 2 and 3 in the conventional four-valve type cylinder head 1. In the example shown in FIG. It is slidably fitted into a fixed guide shaft 4, and in the example shown in FIG. 4, the shaft portion 3a of the valve pusher fitting 3 is slidably fitted into a guide hole 5a of the guide member 5. In the figure, 6 is an intake and exhaust valve, 7 is a valve spring, and 8 is a rocker arm.

``Problems to be solved by the invention'' However, in the conventional guide structure described above, there is a restriction on the height of the cylinder head 1 (normally, the height is approximately equal to the bore diameter). The guide shaft 4 and the guide member 5 are separate parts from the cylinder head 1, and it is not easy to adjust their mounting angle and position as designed, and installation errors inevitably occur. Therefore, as the engine operates, the guide shaft 4, the guide member 5,
Alternatively, the valve pusher fittings 2 and 3 themselves may wear out over time and break.

This invention was made in view of the above circumstances,
4 in an internal combustion engine that is equipped with a guide part that can accurately guide the valve pusher fitting, and in which there is no risk of the guide part or the valve pusher fitting itself being worn out or broken.
The object of the present invention is to provide a valve type cylinder head.

"Means for Solving the Problems" In order to achieve the above object, the four-valve cylinder head of the present invention is constantly biased upward by a valve spring, and a valve pusher is provided by a rocker arm. In a four-valve cylinder head for an internal combustion engine, in which two sets of a pair of valves are arranged, which are operated up and down via a A guide part to be guided is integrally formed, and an air escape passage is formed between the lower part of the guide part and the seating surface at the lower end of the valve spring, the bottom surface of which is lower than the seating surface. It is.

``Operation'' In the four-valve type cylinder head of the present invention, the guide portion of the valve pusher is integrally formed with the cylinder head, so there is no installation error like in the past, and accuracy is improved. The valve pusher is accurately guided, and wear and breakage of the guide portion and the valve pusher itself can be avoided, and the number of parts and man-hours during manufacturing can be reduced. In addition, the pressure generated by the vertical movement of the valve, lubricating oil, water, etc. are discharged into the air escape passage formed below the guide part, and the bottom of this cavity is further away from the seating surface of the valve spring. Since the pressure is also low, water that collects on this seating surface is discharged into the air escape channel.

"Embodiment" An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

In the figure, numeral 10 is a four-valve type cylinder head, which has a height of approximately 1.4D, where D is the bore diameter. A pair of intake ports 11, 11 and a pair of exhaust ports 12, 12 are formed side by side in this cylinder head 10, and a nozzle holder hole 1 is formed between these intake and exhaust ports 11, 12.
3 is formed. The pair of intake ports 11, 11 have a mushroom-shaped valve portion 14a and a shaft portion 1.
4b, and a pair of intake valves 14, 14, which are urged upward by a valve spring 15, are disposed, and the pair of exhaust ports 12, 12 are provided with the intake valves 14, 14.
A pair of exhaust valves (not shown) having the same structure as 4 are provided. Furthermore, the cylinder head 10
A set of rocker arms 16 (only one of which is shown in the figure) is swingably provided on the upper part of the rocker arm 16, and each pair of valves (intake valves 14, 14 are shown in the figure) A substantially T-shaped valve pusher fitting 17 having a shaft portion 17a formed at its lower portion is interposed between the valve pusher fittings 17 and the lower portion thereof.

Further, the cylinder head 10 is integrated so that its outer wall portion 10a, the intermediate portion 10b of the portion where each pair of valves 14, 14 are disposed, and the peripheral portion 10c of the nozzle holder hole 13 are at the same height. Each intermediate portion 10b is cast, and each guide hole (guide portion) 18 having a circular cross section and opening upward with its axis directed upward and downward is formed. The shaft portion 17a of each of the valve pusher fittings 17 is fitted into each guide hole 18 so as to be vertically slidable. Furthermore, a seating surface 2 at the lower end of each guide hole 18 and the lower end of the valve spring 15 is provided.
There is a gap of 19 between it and 0. Applicable interval 1
The bottom surface of the valve 9 is set lower than the seating surface 20, and serves as an oil passage and an air escape passage when the valve pusher 17 slides.

Thus, in the four-valve cylinder head 10, each valve pusher 17 is guided by each guide hole 18 by sliding up and down.

Here, the height of the cylinder head 10 is formed higher than that of the conventional cylinder head, and the intermediate portion 10b where each guide hole 18 is formed is located at the height of the cylinder head 10.
It is formed integrally with the cylinder head during casting. Each guide hole 18 is connected to the shaft portion 14 of the intake and exhaust valve.
Machining together with the machining of the guide sleeve hole etc. in b.
Errors in the forming position, forming angle, etc. can be easily reduced, and the installation error of the guide member as in the conventional case is eliminated, so that the forming part of each guide hole 18 and each valve pusher fitting 17 can be prevented from uneven wear over time. There is no risk of damage or damage.

Further, the intake valve 1
Pressure generated by the vertical movement of 4 (high pressure air)
is eliminated. In addition, during this time, the lubricating oil present in the guide hole 18 and water generated by condensation of moisture in the air during engine cooling are discharged into the valve spring 19. These lubricating oils and water that accumulate in the water flow down and are discharged. Therefore, the intake valve 14 and the valve spring 1
5. In turn, the entire engine operates smoothly over a long period of time.

Further, in the cylinder head 10, each intermediate portion 10b in which each guide hole 18 is formed is connected to each outer wall portion 10a and a peripheral portion 10 of the nozzle holder hole 13.
The overall rigidity is increased because c are connected to each other.

By the way, in the above embodiment, the cylinder head 1
Although each guide portion consisting of each guide hole 18 is integrally formed on the 0, each guide portion consisting of a shaft-shaped portion may be integrally formed instead of each guide hole 18.

"Effects of the Invention" As explained above, the four-valve cylinder head of the present invention is always urged upward by the valve spring, and is moved up and down by the rocker arm via the valve pusher. In a four-valve cylinder head for an internal combustion engine in which two pairs of valves are disposed, a guide part through which the valve pusher is slidably guided is integrated near the upper part of the part where the pair of valves are disposed. An air escape passage is formed between the lower part of the guide portion and the seating surface at the lower end of the valve spring, the bottom surface of which is lower than the seating surface. Since the guide part is integrally formed, there is no installation error like in the past, and the valve pusher fitting is guided accurately, eliminating the installation error and preventing wear and breakage of the guide part and the valve pusher fitting itself. In addition, the number of parts and man-hours during manufacturing are reduced, and the air escape passage formed below the guide part is free from pressure generated by the vertical movement of the valve, lubricating oil, etc. Water is discharged, and since the bottom of this cavity is lower than the seating surface of the valve spring, the water that collects on this seating surface is discharged into the air escape passage, which ensures smooth operation over a long period of time. When the engine is activated, various effects are produced.

[Brief explanation of the drawing]

Figures 1 and 2 show the four-valve cylinder head of the present invention, with Figure 1 being a sectional view, Figure 2 being a plan view, and Figures 3 and 4 respectively showing a conventional cylinder head. FIG. DESCRIPTION OF SYMBOLS 10... Four-valve type cylinder head, 17... Valve pusher fitting, 17a... Shaft portion, 18... Guide hole (guide portion), 19... Between (air escape passage), 20... Seating surface.

Claims (1)

[Scope of utility model registration request] In a four-valve cylinder head for an internal combustion engine, in which two pairs of valves are arranged, which are always urged upward by a valve spring and are actuated up and down by a rocker arm via a valve pusher, A guide part through which the valve pusher fitting is slidably guided is integrally formed near the upper part of the pair of valves, and the lower part of the guide part is connected to the seating surface of the lower end of the valve spring. A four-valve cylinder head for an internal combustion engine, characterized in that an air escape passage is formed between the two, the bottom surface of which is lower than the seating surface.