JPS5898626A - Suction device in internal combustion engine - Google Patents

Abstract

PURPOSE:To prevent a secondary side leak in a low load region by providing a leak-prevention valve at an assembled part of a secondary side suction manifold. CONSTITUTION:In a low load region, a primary side throttle valve 8 is opened within a set opening degree and a secondary side throttle valve 10 is opened. Since a primary suction passage 4 has a small sectional area, a heavy swirl is produced in a combustion chamber 18. For example, when a second cylinder 24-2 assumes a suction stroke, the negative pressure of the cylinder is transmitted through a second secondary suction passage to a leak-prevention valve 26. However, by closing the leak-prevention valve 26, communication from the secondary suction passage 22-2 to other suction passages 22-1 and 22-3 is prevented. In a high load region, a secondary side throttle valve 10 is opened in linkage with a primary side throttle valve 8, and the leak-prevention valve 26 is also opened.

Description

[Detailed Description of the Invention] This invention improves the intake system of the Australian internal combustion Isoseki and maintains a 9% intake leak prevention valve! The present invention relates to an intake system for an internal combustion engine, which is installed at the gathering part of the nitrogen fold, prevents secondary side leakage in a low load range, prevents a decrease in intake flow velocity in the primary intake passage, and improves combustibility and fuel efficiency.

BACKGROUND ART Dual intake internal combustion engines are known that have a primary intake passage for low loads and a secondary intake passage for high loads. In other words, the primary intake passage increases the flow velocity of the small amount of intake air in the low load range to improve the particle size of the fuel, promote the generation of a strong swirl, and improve the lean mixture limit, thereby increasing combustion. The cross-sectional area of the passage has been reduced to improve performance. On the other hand, the secondary intake passage has a large passage cross-sectional area in order to increase filling efficiency in the load range.

However, in a multi-cylinder internal combustion engine with multiple intake passages, the intake! When introducing intake air into the combustion chamber of each cylinder through the Nifold, the primary intake passage and the
Rounding off the intake passage merges with the next intake passage, and in the low load range, the cylinder negative pressure.

It is transmitted to other primary branch passages & IC4 via the secondary branch passages of the cylinder during intake. Therefore, the intake air in the other primary branch passage is sucked I4 and flows back into the secondary branch passage of the cylinder in the suction machine, causing a so-called secondary side leak phenomenon. The intake air due to this secondary side leak phenomenon is introduced into combustion* through the secondary intake passage, which has a large cross-sectional area, so the intake air flow rate is extremely low. Moreover, this secondary side leak intake.

The component in the direction perpendicular to the cylinder surface is also large. Therefore, the generation of a strong swell within the combustion chamber is hindered, and combustibility deteriorates, which is disadvantageous.

Therefore, this invention is I! T! The purpose was to prevent secondary leaks in the low load range by installing a leak prevention valve at the gathering part of the secondary side Q & air manifold, and to prevent the intake air in the primary intake passage. By increasing the flow velocity and atomizing the fuel, it promotes the generation of a strong swirl and improves the lean mixture limit.

An object of the present invention is to provide an intake device for an internal combustion engine that has completely improved combustibility.

Hereinafter, one embodiment 4P4 of the present invention will be described in detail and collectively based on the drawings. In Figures 1 to 4, code 2 is vaporization 4
．． 4 is the primary intake passage for low load, and 6 is the secondary intake passage A for high load.
'N! , 8 is the primary side throttle valve, 10 is the 2-piece throttle valve,
12 is an intake manifold, 14 is a gathering part of the intake manifold, 16 is an intake valve, 18 is a combustion chamber, 20 is a primary branch passage,
22 is a secondary branch passage, and 24 is a cylinder.

The intake manifold 12 connected from the carburetor 2 is connected to its result m1.
Branches into 3 directions from 4 (in case of 3 cylinders).

The opening ends at each cylinder 24-1.2.8.

A leak prevention valve for preventing communication between the secondary branch passages 4 is provided in the collection of secondary intake passages 166 [14] of the same intake manifold.

That is, this leak prevention valve 4 is provided at the upstream end of each secondary branch passage 22-1.2.3, which is the gathering portion 14.

In other words, the valve element 4 that serves as the Sa opening/closing valve, the sliding tube that slidably holds the valve element 28, the cover wing that is crowned on the sliding tube 30, and the cover 321 that penetrates through the tip and lower end. The valve body 4 is attached to the connecting rod 9, a disk-shaped force 2-36 attached to the rear upper end of the connecting rod, and a return spring interposed between the valve body 4 and the cover 32. The leak prevention valve 26 & is constructed from the above. In addition, in the control return spring, the valve body 28t is located downward in Fig. 2.
In other words, the valve body 28f is pressed and fitted into the circular concave retaining portion 40 formed in the assembly [114]. Ensures reliable valve closing function.

A link mechanism is provided which is constructed by this structure and interlocks with the secondary stop valve 26t and the secondary throttle valve lO. This link mechanism housing has a lever holder, and this lever holder is attached to a stay mallet supported by the cover 32 so as to be swingable. For this lever-weak light leak! One part forms a mallet.

This hook part 48 is brought into toothed contact with the back side of the collar. A first rondo group is pivotally attached to the tip of this lever 44 located on the opposite side of the swinging mallet. This rod (material) ft has a substantially semicircular shape extending into the secondary intake passage 6 in the carburetor 2, and rotates integrally with the tip t-secondary throttle valve lO.
14 is pivotally attached to the edge of the plate 52. When the opening degree of the primary 1141 throttle square 8 exceeds a set value (40 degrees in this invention), the secondary throttle valve IO is configured to open in conjunction with the primary throttle valve 8. In addition to this interlocking cross-loading method with the primary throttle valve 8, a boost control method using actuators 54 & C as shown in FIG. 3 can also be used, and if this is done, good results can be obtained. In other words, in this boost control system, the diaphragm group forming the five chambers 56 of the actuator-like diamond 72 and the arm 62 fixed to the throttle valve shaft are wired with the 20th joint and transmitted to the diaphragm fi66. The secondary side throttle valve 10 is opened and closed based on the negative pressure in the intake pipe.

Next, the effect will be explained.

In the low load range, the primary throttle valve 8 is opened within the set opening degree, so the #2 secondary throttle valve 9 is closed. Seventh and ninth, since the cross-sectional area of the two passages in the primary intake passage 4 is small, the intake air is drawn into the combustion chamber 18 at a high flow velocity, producing a strong swirl. For example, when the second cylinder 24-2 is in the intake machine, the negative pressure is transmitted to the leak prevention valve 26 through the secondary intake passage 22-2 of J12. However, due to the closure of this leak prevention valve 26, 47. Since communication from the secondary intake passage 22-2 to other secondary Q&air passages 22-1.3, that is, the first and third secondary Q&air passages 22-1.3, is blocked, it is possible to reliably prevent secondary side leaks. It is.

Next, in order to transition from the low load area to the medium and high load area, 1
When the downstream throttle p valve 8 is opened to a preset value of 11 degrees or more, the secondary throttle valve IO starts opening in conjunction with the I'eKII throttle valve 8. With this opening operation of the secondary throttle valve IO, the control plate 52 also rotates in the direction of the arrow in FIG. For this reason, the lever 44 also rotates in the same direction via the 10th hand 505, and the hook 48 of this lever 44 touches the collar! @
Push up Yosho. Due to this.

The connecting rod rises against the biasing force of the return spring blade, and the valve body 4, which was previously attached, also rises. As a result, the leak prevention valve 26 opens and Vi4 is opened at high load range pressure.
It becomes fully open as shown in Figure 4.

Since the VC and secondary branch passages 22-1.2.3 are in a passable state at this time, branch guidance is provided from the high-load intake RI collecting section 14 to each secondary branch passage 22-1.2.3. and filled in the fire I@vine 18-1.2.3. In addition, when the boost control method shown in Fig. 3 is also used, the effect of negative pressure in the intake pipe can also be obtained.

A more effective opening/closing order of the leak prevention valve 26 is achieved.

Further, by disposing the leak prevention valve 26 in the secondary side manifold gathering part, a rigid effect is obtained in that it is possible to prevent the inconvenient flow of intake air from the carburetor secondary throttle valve 22.

For example, a leak prevention valve that prevents communication between the secondary branch passages is installed at the gathering part of the intake manifold.

A force of 1 is required to reliably prevent secondary side leaks in low-load clay. This difference in intake tlL in the primary intake passage improves fuel atomization, promotes the generation of powerful swirl, improves the lean mixture limit, and improves combustibility. This can lead to improved fuel efficiency.

In addition, since the structure does not interfere with the intake air flow in the medium to high load range, there is no problem of reducing the output. Furthermore, compared to the effects achieved, the structure is extremely simple and the number of parts does not increase.

[Brief explanation of drawings]

FIG. 1 shows an internal combustion engine 1111 according to one example of this invention.
2 is a schematic plan view showing the intake device in FIG. 2, FIG. 2 is a -circle sectional view taken along the line 1 in the lx diagram, and FIG. 3 is a sectional front view showing an actuator that operates the secondary throttle valve shown in FIG. FIG. 4 is a sectional view showing the operating state in a high load region. 4...Primary intake passage for low load, 6...Secondary intake passage for low load, h2-・Intake w=Holt, 14
... joint part, 22 ... secondary branch passage, 26 ... leak prevention valve. Agent Patent Attorney Yoshimi Saigo Figure 1 and 4-3 Figure 2

Claims (1)

[Claims] In a dual-intake internal combustion engine that has a primary intake passage for low loads and a secondary intake passage for high loads, a leak prevention valve that prevents communication between the secondary branch passages is installed in the secondary @ air passage gathering part of the intake manifold. The intake system in an internal combustion engine is made up of 9% mold.