JPS6035540B2 - Flow path control device for helical intake port - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a flow path control device for an IJ cal-type intake boat.

The IJ cal-type intake boat is usually composed of a spiral portion formed around the intake valve and an inlet passage portion that is tangentially connected to the spiral portion and extends almost straight.

If you try to use such a helical intake boat to generate a strong swirling flow in the combustion chamber of the engine when the engine is operating at low speed and low load with a small amount of intake air, the shape of the intake boat will have a large flow resistance. There is a problem in that the filling efficiency decreases when the engine is operated at high speed and under high load with a large amount of air. In order to solve this problem, a branch path is formed in the cylinder head that branches from the helical type intake boat inlet passage and is suitable for the end of the spiral of the helical type intake boat volute. A helical intake boat flow path control device is provided with a normally closed on-off valve operated by an actuator, and the actuator is operated to open the on-off valve when the amount of engine intake air exceeds a predetermined amount. This has already been proposed by the applicant. In this helical type intake boat, when the engine is operated at high speed and under high load with a large amount of engine intake air, part of the intake air sent into the inlet passage of the IJ helical type intake boat passes through the branch path to the IJ.
The flow resistance to the intake air flow is reduced because it is fed into the cull-type intake boat volute, and thus a high filling efficiency can be obtained. However, this flow path control device only shows the basic operating principle, and therefore, there are various problems in terms of assembly man-hours, ease of manufacturing, reliable operation, and manufacturing cost in order to put this flow path control device into practical use. is left behind.
An object of the present invention is to provide a helical intake boat flow path control device having a structure suitable for putting into practical use the above-mentioned basic operating principle that has already been proposed by the applicant of the present application.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

Referring to FIG. 1 and FIG. 2, 1 is a cylinder block, 2 is a piston that reciprocates within the cylinder block 1,
3 is a cylinder head fixed on the cylinder block 1, 4 is a combustion chamber formed between the piston 2 and the cylinder head 3, 5 is an intake valve, 6 is a helical intake boat formed inside the cylinder head 3, 7 8 indicates an exhaust valve, and 8 indicates an exhaust boat formed within the cylinder head 3.

Although not shown in the figure, an ignition plug is disposed within the combustion chamber 4. 3 to 5 schematically show the shape of the helical type intake boat 6 shown in FIG. 2.

As shown in FIG. 4, this helical intake boat 6 is composed of an inlet passage section A in which the flow path axis a is slightly curved, and a spiral section B formed around the valve axis of the intake valve 5.
The inlet passage section A is tangentially connected to the spiral section B. As shown in FIGS. 3, 4, and 7, the upper side wall surface 9a of the side wall surface 9 on the side closer to the spiral axis b of the inlet passage A is formed into a downwardly oriented inclined surface, and this inclined surface The inside of 9a becomes wider as it approaches the spiral part B, and at the connection part between the inlet passage part A and the spiral part B, the entire side wall surface 9 forms a downwardly facing inclined surface 9a, as shown in FIG. It is formed. The upper half of the side wall surface 9 is smoothly connected to the peripheral wall surface of a cylindrical protrusion 11 formed on the upper wall surface of the intake boat around the intake valve guide 10 (FIG. 2), while the lower half of the side wall surface 9 is spirally connected. It is connected to the side wall surface 12 of the spiral portion B at the spiral end portion C of the portion B. Incidentally, the upper wall surface 13 of the spiral portion B is connected to the steeply downwardly inclined wall surface at the spiral end portion C. On the other hand, as shown in FIGS. 1 to 5, a branch passage 14 with a substantially uniform cross section is formed in the cylinder head 3, branching from the inlet passage part A, and this branch passage 14 is connected to the spiral terminal part C. Connected.

The entrance gate 15 of the branch passage 14 is formed on the side wall surface 9 near the entrance opening □ of the inlet passage section A, and the exit opening □ 16 of the branch passage 14 is formed at the upper end of the side wall surface 12 at the spiral terminal end C. . The upper twill portion of this outlet closing port 16 is connected flush with the upper wall surface 13 of the spiral portion B, and the exit closing port 16 is connected flush with the upper wall surface 13 of the spiral portion B
It is formed so as to face a swirling flow that swirls in a spiral direction along the upper wall surface 13 of. An on-off valve insertion hole 17 is formed in the cylinder head 3 and extends through the branch passage 14, and a port valve 18 functioning as a passage on-off valve is inserted into each of the on-off valve insertion holes 17. Referring to FIG. 9, the sliding valve 18 has a hollow sleeve 1 iron-fitted in the opening/closing valve insertion hole 17.
9, a valve body 20 movably inserted into the hollow sleeve 19 and capable of protruding into the branch passage 14, and a piston 22 coupled to the valve body 20 via a rod 21, the rod 21 It passes through a partition 23 formed within the hollow sleeve 19. Outer peripheral surface of hollow sleeve 19 and on-off valve insertion hole 17
A pair of ○ rings 24 and 25 are inserted between the inner peripheral surfaces of
A sealing village 26 is mounted on the partition wall 23 in sealing contact with the rod 21. A compression spring 27 is inserted between the valve body 20 and the partition wall 23 to constantly press the valve body 20 downward, and a plurality of compression springs 27 are inserted on the outer peripheral surface of the valve body 20 as shown in FIGS. 9 and 10. An air relief groove 28 is formed. On the other hand, a stopper hole 29 is bored in the upper part of the hollow sleeve 19, and in the embodiment shown in FIG. A working hydraulic chamber 3 formed between the piston 22 and the partition wall 23
An annular lubricating oil passage 3 formed around the hollow sleeve 19 via an oil introduction hole 31 formed in the hollow sleeve 19
Lotus is suitable for 2. This annular lubricating oil passage 32 is a lubricating oil passage 33
It is connected to a collecting passageway 34 which leads to the sliding valve 18 of each cylinder via the cylinder. The collective passage 34 is the lubricating oil supply passage 3 extending downward.
5. It is followed by an engine-driven lubricating oil supply pump (not shown) via an electromagnetic on-off valve 36 and a lubricating oil supply passage 37, and the solenoid of the electromagnetic on-off valve 36 is connected to an output terminal of an electronic control unit 38. On the other hand, the collective passage 34 is connected to a lubricating oil reservoir (not shown) through a lubricating oil return passage 39 extending upward, a throttle passage 40 having a cross-sectional area of 4, and a lubricating oil return passage 41. Furthermore, as can be seen from Fig. 9, the throttle passage 4
0' is disposed above the collective passage 40 and above the hydraulic pressure chamber 30. The electronic control unit 38 is comprised of a digital computer, including a microprocessor (MPU) 50 that performs various calculation processes, a random access memory (RAM) 51, and a read-only memory (ROM) 52 in which control programs, calculation constants, etc. are stored in advance. , an input boat 53 and an output boat 54 are connected to each other via a bidirectional bus 55.

Furthermore, a clock generator 56 is provided within the electronic control unit 38 for generating various clock signals. A negative pressure sensor 57 is connected to the input boat 53 via an AD converter 58, and a rotation speed sensor 59 is further connected to the input boat 53. The negative pressure sensor 57 generates an output voltage proportional to the negative pressure in the intake manifold downstream of the carburetor (not shown), and this voltage is converted into a corresponding binary number by the AD converter 58, and this binary number is sent to the input port 53. It is also read into the MPU 50 via the bus 55. The rotation speed sensor 59 generates a pulse every time the crankshaft rotates by a predetermined crank angle, and this pulse is sent to the input boat 53 and the bus 55.
The MPU5 is loaded via. On the other hand, the output boat 54 is connected to the solenoid of the electromagnetic on-off valve 36 via a power increase circuit 60. FIG. 11 shows the relationship between the engine rotational speed N (r.p.m.) at which the electromagnetic on-off valve 36 should be operated and the negative pressure P (per day) in the intake manifold.

Note that the electromagnetic on-off valve 36 is operated in the hatched area above the solid line W in FIG. The relationship between engine speed N and negative pressure P, indicated by a solid line W in FIG. 11, is stored in the ROM 52 in advance in the form of a function or data table. The MPU 50 calculates the engine rotation speed N from the output signal of the rotation speed sensor 59, and calculates the engine rotation speed N.
and the output signal of the negative pressure sensor 57 representing the negative pressure P are stored in the ROM.
When the engine speed N and the negative pressure P are in the hatched area in FIG. 11, a drive signal is written to the output boat 54. At this time, the solenoid of the electromagnetic on-off valve 36 is energized, so the electromagnetic on-off valve 3
6 is closed, and as a result, pressurized lubricating oil is supplied into the collective passage 34 via the lubricating oil supply passage 37, the electromagnetic on-off valve 36, and the lubricating oil supply passage 35. This lubricating oil then passes through the throttle passage 40 on the one hand and the lubricating oil return passage 4 on the other hand.
1 to the lubricating oil reservoir, and on the other hand it flows into the hydraulic pressure chamber 30 via the annular lubricating oil passage 32. At this time, since the cross-sectional area of the throttle passage 40 is quite small, the collective passage 4
The pressure in the valve 0 is quite high, so that the piston 22 rises against the compression spring 27, causing the valve body 20 to rise and open the branch passage 14. Furthermore, since an air relief groove 28 is formed on the outer peripheral surface of the valve body 20, even if the valve body 20 rises, the internal chamber of the hollow sleeve between the valve body 20 and the candle 23 will not be pressurized. , thus the valve body 20 is easily raised. When the piston 22 rises, the separator hole 29 opens into the working hydraulic pressure chamber 30, so that the lubricating oil in the working hydraulic pressure chamber 30 flows out from the opening 29, and as a result, the lubricating oil pressure in the working hydraulic pressure chamber 30 decreases. The piston 22 stops when the opening 29 closes into the hydraulic pressure chamber 30. Therefore, the opening 39 serves as a stopper that restricts the upward position of the piston 22. Further, as described above, since the aperture 29 is oriented toward the stem of the intake valve 5, the lubricating oil jetted from the aperture 29 can lubricate the space between the stem of the intake valve 5 and the guide 10. Note that the checkpoint hole 29 can be directed toward a location on the cylinder head that requires lubrication, such as a cam surface of a valve mechanism. On the other hand, when the intersection of the engine speed N and the negative pressure P moves to a region other than the hatched region in FIG.
is closed.

At this time, the lubricating oil in the hydraulic pressure chamber 30 gradually flows out through the throttle passage 40, so the piston 22 gradually descends, and the valve body 20 blocks the branch passage 14. As mentioned above, since the throttle passage 40 is provided above the collective passage 34 and the hydraulic pressure chamber 30, even when the piston 22 reaches the lowest position, the collective passage 34 and the hydraulic pressure chamber 3 are filled with lubricating oil. ing. Therefore, when the electromagnetic on-off valve 36 is opened again, the inside of the hydraulic pressure chamber 30 can be pressurized immediately, and the branch passage 14 can thus be opened immediately. In FIG. 11, the hatched area indicates a region where the amount of intake air is large. Therefore, when the amount of intake air is large, the
It can be seen that the alcohol valve 18 is opened and the alcohol valve 18 is closed when the amount of intake air is small. As described above, the sliding valve 18 blocks the branch passage 14 when the engine is operated at low speed and under low load with a small amount of intake air.

At this time, the air-fuel mixture sent into the inlet passage part A descends into the swirl part B while swirling along the upper wall surface 13 of the swirl part B, and then flows into the combustion chamber 4 while swirling, so that the mixture enters the combustion chamber 4. 4
A strong swirling flow is generated inside. On the other hand, when the engine is operated at high speed and under high load with a large amount of intake air, the sliding valve 18 is opened, so that a part of the Nami Aiki sent into the inlet passage A flows through the branch passage 14 with low flow resistance to the spiral part B. sent inside. As mentioned above, the upper green end of the outlet opening row 6 of the branch passage 14 is connected flush with the upper wall surface 13 of the spiral part B, so that the air-fuel mixture flowing out from the branch passage 14 flows along the upper wall surface 13 of the spiral part B. It collides head-on with the swirling total air mixture flow, thereby decelerating the total air mixture flow along the upper wall surface 13 of the swirl portion B. That is, among the swirling flows generated in the swirling portion B, the swirling flow along the upper end surface 13 of the swirling portion B is the strongest, and the entire air mixture flow having this swirling force is decelerated. In this manner, when the engine is operated at high speed and under high load, the sliding valve 18 opens, which not only increases the overall flow path area, but also decelerates the entire air mixture flow, which has a strong swirling force, thereby increasing the swirling flow. Since it is weakened, high filling efficiency can be ensured. Further, as described above, by providing the inclined surface 9a, a part of the air-fuel mixture fed into the inlet passage A is given a downward force, and as a result, the air-fuel mixture is moved to the lower wall of the inlet passage A without swirling. Since the fluid flows into the spiral portion B along the curve, the inflow resistance becomes small, thus making it possible to further improve the filling efficiency during high-speed, high-load operation. As described above, according to the present invention, the upper green end of the branch outlet opening □ is connected flush with the upper wall surface of the spiral part, so that the air-fuel mixture flows out from the branch channel when the slide valve opens. This makes it possible to decelerate the total air mixture flow that swirls with a strong swirling force along the upper wall surface of the swirling portion, and in this way, the swirling flow can be weakened to a large extent, so that high filling efficiency can be obtained.

Further, according to the present invention, the opening and closing of the branch passage can be controlled by a simple mechanism using the lubricating oil pressure provided in the main body of the engine, so that reliability can be improved and manufacturing costs can be reduced. Furthermore, by adopting hydraulic control using lubricating oil pressure, the size of the slide valve can be reduced, so that it can be easily installed in a cylinder head with a narrow space. Furthermore, since the piston-operated hydraulic chamber of the sliding valve is always connected to the lubricant reservoir via the lubricant return throttle passage, even if there is a leak in the electromagnetic on-off valve, the leaked pressurized lubricant will flow through the throttle passage. Since the lubricating oil reservoir is returned to the lubricating oil reservoir through When the electromagnetic on-off valve is closed, the branch can be immediately closed.

[Brief explanation of the drawing]

FIG. 1 is a plan view of an internal combustion engine according to the present invention, and FIG.
3 is a perspective view showing the shape of the helical intake boat, 4 is a plan view of 3, and 5 is a branch road of 3. 6 is a sectional view taken along the line W- in FIG. 4, and FIG.
The figure is a sectional view taken along the skin-to-skin line in Figure 4, Figure 8 is a sectional view taken along the skin-to-leg line in Figure 4, Figure 9 is an overall view of the flow path control device, and Figure 10 is a sectional view taken along the skin-to-skin line in Figure 4. The figure is a sectional view taken along the line XX in FIG. 9, and FIG. 11 is a diagram showing the valve opening area of the loss-operating valve. 5... Intake valve, 6... Helical intake boat, 14... Branch path, 18... Sliding valve, 2
0... Valve body, 36... Solenoid on-off valve. Figure 2: Grandson 6 Figure: Grandchild l Figure 3: Shigetsu 7 Figure 8: Grandson ll Administration 4 Figure 5: Scales 9 Figure: Mackerel l○ Figure

Claims (1)

[Claims] 1. In a helical intake port configured with a spiral portion formed around the intake valve and an inlet passage portion connected tangentially to the spiral portion and extending almost straight, a branch branched from the inlet passage portion. The outlet opening of the passage is communicated with the spiral terminal end of the spiral portion, and the exit opening is formed at the upper end of the side wall surface of the spiral portion so as to oppose the swirling flow along the upper wall surface of the spiral portion, and the upper end of the exit opening The edge is connected flush to the upper wall surface of the spiral part, a hydraulically driven sliding valve for controlling the opening and closing of the branching passage is inserted into the branching passage, and the operating hydraulic chamber of the sliding valve is adjusted in response to the amount of intake air. A flow path control device for a helical intake port, which is connected to a hydraulic power source via a switching valve that opens the sliding valve when the amount of intake air exceeds a predetermined amount.