JPS62199923A - Intake device for internal combustion engine - Google Patents

Abstract

PURPOSE:To achieve a high output and a reduced fuel consumption by providing two intake ports with the valve diameter at the helical side being shorter than that at the straight side and setting the valve closing timing at the helical side slower than that at the straight side. CONSTITUTION:An intake port 2 of a cylinder head 1 is branched into a helical port 2a and a straight port 2b, and intake valves 3a, 3b are provided to respective ports. The diameter (d1) of the intake valve 3a at the helical port side is made shorter than the diameter (d2) of the intake valve 3b at the straight port side, and the closing timing of the intake valve 3a is set slower than that of the intake valve 3b. Consequently, the deterioration of the intake capacity is suppressed to produce a high output, while the improved combustion and the reduced fuel consumption can be achieved through the production of swirl.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to an intake device for an internal combustion engine that improves output while reducing fuel consumption and improving combustion through a swirl effect in a two-intake valve engine.

[Conventional technology]

Conventionally, in a two-intake valve engine, a device called tIC has been developed to improve the swirl generation effect, for example, in JP-A-58-14.
A combination V in which one of two intake valves is a helical port and the other is a straight port is known, as disclosed in Japanese Patent Application Laid-open No. 8229 and Japanese Patent Application Laid-open No. 135323/1983. In addition to the combination of the two intake valves mentioned above, as shown in FIGS. 3 and 4, the helical port side valve diameter d
3 is larger than the straight port side valve diameter d4,
In addition, valve timing has been put into practical use that allows the helical port side to open earlier.

[Problems to be solved by the invention]

However, in the conventional embodiments described above, it is difficult to aim for high output because the valve diameter on the side of the calport where intake resistance is large is large, and the frontage period is also good. In addition, in the case of two intake valves, for example, Japanese Patent Application Laid-Open No. 58285
As shown in Publication No. 11, some attempts have been made to install a control valve in the straight port side passage to suppress the output drop and improve swirl generation, but there are drawbacks such as the complicated mechanism and high cost. be.

OBJECTIVE OF THE INVENTION 1 The present invention has been made based on the above-mentioned circumstances, and the intake system of the engine is a two-intake valve engine consisting of a helical port and a straight port. It is an object of the present invention to provide an intake device for an internal combustion engine that aims to reduce fuel consumption and improve combustion due to the swirl generation effect while suppressing a decrease in output by combining the following. [Means for Solving the Problems] In order to achieve the above object, according to the present invention, in a two-intake valve engine, one of the two intake ports is a helical port 1~, the other is a straight port, and one of the two intake ports is a helical port. The diameter of the valve on the helical side is smaller than that on the straight side, and the closing time of the valve rlJI on the helical side is set later than that on the straight side (2).

[Function] Based on the above configuration, according to the present invention, in a two-intake valve engine, the valve diameter on the straight side is large, and together with the intake air from the helical port, the valve has sufficient intake capacity, and the helical port side The decrease in output due to the increase in intake resistance can be suppressed as much as possible. Also, even after the straight side valve is closed, the helical side valve remains open, so
Air is taken in from the helical side valve, creating a swirl inside the cylinder, and since the diameter of the helical side valve is small, the flow velocity of the intake gas is high and the energy of the swirl is large, making it possible to improve combustion. . [Example] Hereinafter, an example according to the present invention will be described in detail based on FIGS. 1 and 2. In the figure, numeral 1 is a cylinder head of a two-intake valve engine, 2 is an intake port, 2a is a helical port, 2b is a straight port, 38 is an intake valve on the helical port side, 3b is an intake valve on the straight port side, 4 is an exhaust valve, 5 indicates a combustion chamber. In the above two-intake valve engine, the diameter d1 of the helical port side intake valve 3a is set smaller than the diameter of the straight port side intake valve 3b (d t < d 2 ), and the closing timing θ1 of the intake valve 3a side is set straight. This is set later than the closing timing θ2 of the port side valve 3b. Note that the opening timings of the two intake valves 3a and 3b are set to be the same. Therefore, the operation of the two-intake valve engine configured as described above is such that the valve of the stray 1-port side intake valve 3b (Vdt is too large <<2, so the helical port side intake valve 3a is Since it has sufficient intake capacity together with intake, even if the intake resistance of the heel port increases, it is possible to reduce the output reduction by reducing the scratching force.In addition, the straight port side intake valve 3b has rJ1 Even after the helical port side intake valve 3a is closed, the intake valve 3a on the helical port side continues to operate, so the intake air is taken in through the helical port side intake valve 3a, and it is possible to generate a swirl in the combustion chamber 5. Moreover, the helical port side intake valve 3a Since the valve diameter d1 of the valve 3a is small, the flow velocity of the intake gas is high, and the swirl generation energy can be increased. [Effects of the Invention] As described above in detail, the intake device for an internal combustion engine according to the present invention In a two-intake valve engine, one is a helical port and the other is a straight port, and the valve diameter on the helical port side is smaller than the valve diameter on the straight port side, and the valve rfI closing timing on the helical port side is The configuration that slows down the intake capacity suppresses the decrease in intake capacity as much as possible, making it possible to achieve the output characteristic of a two-intake valve engine, as well as improving combustion through the swirl generation effect and reducing fuel consumption. In addition, since there is no special additional mechanism, the structure can be
There is no increase in cost.

[Brief explanation of drawings]

FIG. 1 is a top view of a cylinder head showing the schematic configuration of a two-intake valve engine according to the present invention, FIG.
The figure is a sectional view of a cylinder head showing a conventional two-intake valve engine, and FIG. 4 is an explanatory diagram showing conventional valve timing. 1... Cylinder head, 2... Intake bow +-12a
...Helical port, 2b...Straight port,
3a...Helical port/side intake valve, 3b...
Straight port side intake valve, 4...exhaust valve,
5... Combustion chamber. Patent Applicant Fuji Heavy Industries Co., Ltd. Agent Patent Attorney Nobu Kobashi Jundo Patent Attorney Susumu Murai 1rl!
J Figure 2

Claims (1)

[Claims] In a two-intake valve engine, one of which is a helical port and the other is a straight port, the valve diameter of the helical side of the two intake ports is smaller than that of the straight side, and the valve closing timing of the helical side is adjusted. An intake device for an internal combustion engine characterized by being set later than the straight side.