JPS62203907A - Intake and exhaust valve device for internal combustion engine - Google Patents

Abstract

PURPOSE:To compact and lighten the device in the caption by constituting an intake and exhaust valves to be driven by one cam shaft, in the device using a substantially globose or substantially cylindrical valve as the intake valve and a poppet valve as the exhaust valve. CONSTITUTION:Only one cam shaft 13 is provided for driving to open and close an exhaust valve 11 and an intake valve 12 in a device using a ceramic cylindrical rotary valve as the intake valve 12 and a poppet valve as the exhaust valve 11. The cam shaft 13 is rotated by the rotations of a crank shaft through a timing belt 17 and a timing pulley 16. And, the exhaust valve 11 is vertically moved by a cam 14 monolithically provided on the cam shaft 13 through a rocker arm 18 to be opened and closed, and the intake valve 12 is opened and closed by engagement of the cam 14 with a protrusion 19 provided on an end surface of the intake valve 12. Thereby, high speed rotations and high power can be obtained with the compact and light device.

Description

DETAILED DESCRIPTION OF THE INVENTION "Industrial Application Field" The present invention is suitably applied to an intake/exhaust valve device that controls the inflow and outflow of intake gas and exhaust gas in an internal combustion engine.

``Prior Art'' Conventionally, in a valve mechanism for controlling the inflow and outflow of intake gas and exhaust gas into the combustion chamber of an internal combustion engine, the shape of the intake valve and exhaust valve is an umbrella-shaped poppet valve. Opening and closing was done by the vertical movement of the valve body.

"Problems to be Solved by the Invention" According to the above-mentioned valve mechanism, there have been problems such as valve body lifting, surging, and noise during high-speed operation. In order to solve this problem, a valve mechanism using a rotary valve body that does not require vertical movement of the valve body has been proposed (Japanese Patent Application Laid-Open No. 60-8
No. 0410 (4-cycle engine) had many problems such as wear caused by the seat during sliding of the rotary valve and incomplete sealing due to explosion pressure, especially on the exhaust side.

"Means for Solving the Problems" The present invention has been made to solve the above problems, and the means is to use a substantially spherical or substantially cylindrical valve for the intake valve that requires a large valve diameter. In an internal combustion engine intake/exhaust valve device using a poppet valve for an exhaust valve that is difficult to seal and requires a small valve diameter, a single camshaft is used to drive the intake/exhaust valve.

"action" The operation of the present invention will be explained based on FIGS. 1 and 2.

FIG. 1 is a cross-sectional view of an intake/exhaust valve device and its surrounding parts according to an embodiment of the present invention, and FIG. 2 is a perspective view of essential parts of the intake/exhaust valve device.

In FIG. 1, 11 is an exhaust valve such as a poppet valve;
Reference numeral 2 indicates a ceramic intake valve made of a cylindrical rotary valve, and both can be driven by a single camshaft 13. In general, intake and exhaust valves are used to (a) easily inhale and exhaust air in an extremely short period of time when the piston completes one cycle, increasing volumetric efficiency; (b) compressing when both valves are closed;
It must satisfy conditions such as maintaining sufficient airtightness during the expansion stroke, and (c) operating correctly even when exposed to the high temperature of combustion gas and withstanding long-term operation. Therefore, in the present invention, by using a substantially spherical or substantially cylindrical valve for the intake valve, it is possible to make the valve made of ceramics, thereby reducing weight, and the intake valve opens and closes by its own rotation or rocking. Therefore, inertia force can be reduced.

Moreover, since it is cooled by intake air, gas sealing is easy and a large opening area can be obtained, increasing body efficiency. Furthermore, even during high-speed operation, there is no fear of surging of the valve spring or excessive pressure of the cams 14, 14', and the operation is reliable.

On the other hand, the exhaust valve 11 is preferably a poppet valve because the valve diameter is small and sealing is difficult.

As for drive devices, conventional poppet valves for both the intake and exhaust valves are often unsuitable for high-speed rotation when driven by a single camshaft, especially when the number of valves increases. Drive by a camshaft was difficult, so two camshafts were used. In contrast, the present invention uses a poppet valve on the exhaust side and a rotary valve on the intake side, and is driven by a single camshaft, thereby simplifying the structure and making the engine itself smaller.

In addition, even if three or more intake and exhaust valves are required for one cylinder, since the valves are approximately spherical or approximately cylindrical, by connecting them in series on the valve shaft, a single camshaft can operate the cylinder. It is possible to drive all intake valves.

Although the intake valve 12 can be opened and closed by rotary motion, it is preferable to use rocking motion because it is easier to adjust the opening time and speed of the intake boat.

"Example" Example 1 The drive mechanism of the intake and exhaust valve device of the present invention shown in FIGS. The force is transmitted via the timing belt 17 to rotate the camshaft 18. camshaft 13
has the same number of cams 14 as the number of exhaust valves 11 (one in the figure).
', and a cam 1 that drives a mechanism that opens and closes the intake valve 12.
4 are arranged. On the exhaust side, the rocker arm 18 is actuated by the rotation of the cam 14' to move the exhaust valve 11 up and down to open and close it. On the intake side, a protrusion 19 provided on the end face of the substantially cylindrical intake valve 12 is configured to make a rocking motion by the rotation of the cam 14 while contacting the cam 14 to open and close the intake valve 12. .

When the above intake/exhaust valve device was assembled into a 4-cylinder, 4-cycle engine with a cylinder diameter of 80+o+φ and a stroke of 100 mm and operated, an output of 120 ps was obtained at 8000 rpm. For comparison, when a conventional intake/exhaust valve device consisting of metal poppet valves for both the intake and exhaust valves was installed in the above 4-stroke engine and operated, the engine speed was 10 at 6000 rpm.
Only an output of 0 ps was obtained. By the way, the weight of the intake/exhaust valve device according to this embodiment was about 70 times the weight of the conventional intake/exhaust valve device.

Embodiment 2 FIG. 3 is a perspective view showing an intake and exhaust valve device according to another embodiment of the present invention.

Except that the intake valves 22 and 22' are approximately spherical, the two valves are coaxially connected, and a cam 29 is provided on the end face instead of the protrusion 19 to contact the cam 24. The rest of the structure is the same as in Example 1. In such a case as well, the effects of the present invention are produced as in Example 1.

"effect" Achieves high cylinder rotation output. Less likely to cause surging.

It is small and lightweight.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an intake/exhaust valve device according to one embodiment of the present invention, FIG. 2 is a perspective view of the same, and FIG. 8 is a perspective view of an intake/exhaust valve device according to another embodiment of the present invention. .

Claims (3)

[Claims] (1) In an internal combustion engine intake/exhaust valve system that uses a substantially spherical or substantially cylindrical valve for the intake valve and a poppet valve for the exhaust valve, it is possible to drive the intake and exhaust valves using a single camshaft. Characteristic intake and exhaust valve devices for internal combustion engines. (2) The intake and exhaust valve device for an internal combustion engine according to claim 1, wherein the intake valve opens and closes by a rocking motion. (3) Claim 1, characterized in that at least one cam that drives an exhaust valve is provided between a timing pulley or sprocket that drives a camshaft and a mechanism that drives an intake valve. The intake and exhaust valve device for the internal combustion engine described.