JPH01106910A - Rotary valve type internal combustion engine - Google Patents

Abstract

PURPOSE:To enable reduction of flow resistance of intake air and exhaust gas, by a method wherein an ignition plug is mounted to a valve rotor. CONSTITUTION:A valve rotor 11 rotated in linkage with a crank shaft is mounted to a cylinder head 2. A recessed part 14, opened to a combustion chamber 6 during the terminal stage of a compression stoke, is formed in the valve rotor 11. An ignition plug 16 is mounted to the valve rotor 11, and is situated so that an electrode part 16a is positioned facing the interior of the recessed part 14. The size of the valve rotor can be increased by an amount equivalent to the size of the ignition plug not mounted to the cylinder head. This constitution enables reduction of flow resistance of intake air and exhaust gas.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a so-called rotary valve type internal combustion engine in which an intake valve and an exhaust valve are configured as rotary valves.

[Conventional technology and its problems]

It is well known that the intake valve and exhaust valve for an internal combustion engine are configured as rotary valves, as described in, for example, Japanese Patent Laid-Open No. 51-87613.
In this conventional rotary valve type internal combustion engine, a valve rotor that rotates in conjunction with the crankshaft of the internal combustion engine is provided in the cylinder head on the upper surface of the cylinder block, and this valve rotor is provided with a valve rotor that rotates in conjunction with the crankshaft of the internal combustion engine. An intake passage that opens and an exhaust passage that opens into the combustion chamber during the exhaust stroke are provided, and the cylinder head is provided with an ignition plug that extends into the combustion chamber.

Internal combustion engines that use rotary valves for intake and exhaust valves can reduce noise and vibration as well as reduce power loss compared to engines that use poppet-type intake and exhaust valves, and are capable of high-speed rotation. However, by providing the cylinder head with a valve rotor having an intake passage and an exhaust passage, the head of the internal combustion engine becomes larger.

However, in the conventional rotary valve type internal combustion engine described above, the valve rotor and spark plug are separately provided in the cylinder head, and in order to avoid increasing the size of the head of the internal combustion engine as much as possible. In this case, the diameter of the valve rotor must be reduced by the space required to mount the spark plug in the cylinder head so that it looks into the combustion chamber.

Therefore, it is not possible to increase the passage area of the intake passage and exhaust passage provided in the valve rotor, so the flow resistance of intake air and the flow resistance of exhaust gas increase, resulting in a decrease in output and an increase in fuel consumption. Moreover, the electrode part of the ignition plug, which is attached to the cylinder head so as to look into the combustion chamber, is located in a part of the valve rotor that is shaded from the intake air flowing into the combustion chamber from the intake passage. The scavenging performance near the spark plug was poor, making ignition and combustion by the spark plug unstable.

The present invention provides a rotary valve type internal combustion engine that solves this problem.

[Means for solving problems]

For this reason, the present invention provides a cylinder head fastened to the cylinder block with a valve rotor that rotates in conjunction with the crankshaft, and this valve rotor has an intake passage that opens into the combustion chamber during the intake stroke and an intake passage that opens into the combustion chamber during the exhaust stroke. In a rotary valve internal combustion engine provided with an exhaust passage that opens, the valve rotor is provided with a recess that opens into the combustion chamber at the end of the compression stroke;
An ignition plug is attached to the valve rotor so that an electrode portion of the ignition plug extends into the recess.

[Action/effect of the invention]

Instead of installing the spark plug that looks into the combustion chamber on the cylinder head side as in the conventional case, it is installed on the rotating valve rotor side as described above, making the head size of the internal combustion engine smaller than in the conventional case. Under the same conditions, the diameter of the valve rotor can be increased by eliminating the need to provide a spark plug in the cylinder head that extends into the combustion chamber. This allows the passage area of the passage to be increased.

In addition, when the concave part with the spark plug opens into the fuel chamber as the valve rotor rotates, the intake air mixture sucked in during the previous intake stroke is spread throughout the combustion chamber by the upward movement of the piston. As the valve rotor rotates, the ignition plug will be exposed to the combustion chamber, which is compressed and filled to the max. , it can be accelerated to an extent that is incomparable to the conventional method.

Therefore, according to the present invention, the flow resistance of intake and exhaust gases can be reduced, and the ignition and combustibility of the ignition plug can be improved, so that the rotary valve type internal combustion engine can achieve higher output, lower fuel consumption, and lower pollution. It produces effects that can be achieved with certainty.

〔Example〕

The following describes the drawings in which the embodiments of the present invention are applied to a four-stroke internal combustion engine. In the drawings, reference numeral 1 indicates:
Cylinder block 2 indicates a cylinder head fastened to the upper surface of the cylinder block 1 with a plurality of bolts 3, and the cylinder block 1 has a cylinder bore 5 in which a reciprocating piston 4 is built. Further, the cylinder head 2 has a combustion chamber 6 on its lower surface, an intake boat 7 on its left side, and an exhaust port 8 on its right side, and the intake port 7 has an intake manifold 9 and an exhaust port 8 are connected to exhaust manifolds 10, respectively.

Reference numeral 11 denotes a valve rotor made of a heat-resistant material such as ceramic, which is rotatably provided in the throat 2 of the cylinder. The valve rotor 11 is provided with an intake passage 12 configured to communicate between the intake port 7 and the combustion chamber 6 during the intake stroke, and the valve rotor 11 is provided with an intake passage 12 configured to communicate between the intake port 7 and the combustion chamber 6 during the intake stroke. An exhaust passage 13 is provided so that the exhaust port 8 and the combustion chamber 6 communicate with each other.

Note that the axis of the valve rotor 11 is parallel to the axis of the crankshaft.

A recessed portion 1 that opens into the combustion chamber 6 at the end of the compression stroke is provided on the outer peripheral surface of the valve rotor 11.
4 is provided in the valve rotor 11, while the recessed portion 1 is provided in the valve rotor 11.
A female threaded hole 15 is drilled at the bottom of 4, and this female threaded hole 15
The spark plug 16 is connected to the electrode portion 16a of the spark plug 16.
It is removably screwed so that it extends into the recessed part 14.

Note that the ignition plug 1 is provided on the side surface of the valve rotor 11.
A negative (earth) terminal 17 is electrically connected to one electrode of the spark plug 16, and a positive terminal 18 is electrically connected to the other electrode of the spark plug 16. is configured to include a center electrode 20 that presses into contact with the negative terminal 17 and side electrodes 20 that are close to the positive terminal 18, so that the ignition plug 16 is energized at a predetermined time. has been done. Further, a hole 22 for attaching and detaching the spark plug 16 is provided on the upper surface of the cylinder head 2, and the hole 22 for attaching and detaching the spark plug 16 is provided with a blind that is configured to be detachably attached using a bolt 24 or the like. It is closed with a lid 23.

In this configuration, during the intake stroke in which the piston 4 moves downward, the valve rotor 11 is in a state where the intake port 7 and the combustion chamber 6 are in communication with each other through the intake passage 12 provided therein. , a new intake air mixture is taken in from the intake manifold 9, and then during the compression stroke in which the piston 5 moves upward, the intake air mixture in the cylinder bore 5 is pushed up toward the combustion chamber 6 and compressed, and the compression stroke At the end of the combustion chamber 6, the concave portion 14 of the valve rotor 11 opens and the vicinity of the electrode portion 1.6a of the spark plug 16 is scavenged by the compressed air-fuel mixture in the combustion chamber 6. The spark produced by the portion 16a can reliably ignite and burn the air-fuel mixture.

Then, when the explosion stroke shifts to the exhaust stroke in which the piston 5 moves upward, the combustion chamber 6 and the exhaust port 8 communicate with each other through the exhaust passage 13 as the valve rotor 11 rotates, so that the exhaust gas is exhausted. The air is exhausted from the manifold 10.

Note that the present invention can also be applied to a case where a plurality of spark plugs 16 are provided as shown in FIG. If the recess 14 with the ignition plug 16 is configured to open only to the intake port 7 during one rotation of the valve rotor 11 by providing the ignition plug 16 at a location shifted from the ignition plug 8, This has the advantage that the scavenging performance in the vicinity of the electrode portion 16a can be further improved, and the heat load on the ignition plug 16 can be reduced.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a longitudinal sectional front view, FIG. 2 is a plan sectional view taken along the line ■-■ in FIG.
-m sectional view, FIGS. 4 and 5 are sectional views showing another embodiment. ■... Cylinder block, 2... To cylinder, 4... Piston, 5... Cylinder bore, 6
... Combustion chamber, 7... Intake port, 8... Exhaust bow 1~. 9...Intake manifold, 10...
・Exhaust manifold, 11... Valve rotor, 12
...Intake passage, 13...Exhaust passage, 14...
- Recessed portion, 16... Spark plug, 22... Hole for installing and removing the spark plug, 23... Blind lid. Patent applicant Daihatsu Motor Co., Ltd. = 10-

Claims (1)

[Claims] (1), to the cylinder head fastened to the cylinder block,
A rotary valve type internal combustion engine comprising a valve rotor that rotates in conjunction with the crankshaft, and this valve rotor is provided with an intake passage that opens into the combustion chamber during the intake stroke and an exhaust passage that opens into the combustion chamber during the exhaust stroke. In,
The valve rotor is provided with a recess that opens into the combustion chamber at the end of the compression stroke, and an ignition plug is provided.
A rotary valve type internal combustion engine, wherein the valve rotor is mounted such that an electrode portion of the spark plug extends into the recessed portion.