JPS6026184Y2 - 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 a helical intake port.

A helical intake port usually includes a spiral portion formed at the intake position and an inlet passage portion tangentially connected to the spiral portion and extending substantially straight.

Such a helical intake port is used to generate a strong swirling flow within the engine combustion chamber when the engine is operating at low speed and paper load with a small amount of intake air. 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 off from the helical intake port inlet passage and communicates with the spiral end of the helical intake port spiral section, and an actuator is actuated within the branch path. The present applicant has developed a helical intake port flow path control device that is equipped with a normally closed on-off valve and operates an actuator to open the on-off valve when the amount of engine intake air becomes larger than a predetermined amount. has already been proposed by.

In this helical type intake port, 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 helical type intake port inlet passage is sent into the helical type intake port spiral part through the branch passage. The flow resistance to the intake air flow is reduced 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.

The object of the present invention is to provide a helical intake port 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.

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 cylinder block, 2 is a piston that reciprocates within the cylinder block 1,
3 is a cylinder head fixed on the cylinder tab recess 1; 4 is a combustion chamber formed within the piston 2 and the cylinder head 3; 5 is an intake valve; 6 is a helical intake boat formed within the cylinder head 3; Reference numeral 7 indicates an exhaust valve, and reference numeral 8 indicates an exhaust port 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 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 of the inlet passage A on the side closer to the spiral axis
is formed as an inclined surface facing downward, and the width of this inclined surface 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 width of the inclined surface 9a becomes wider as shown in FIG. The entire wall surface 9 is formed into an inclined surface 9a facing downward.

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 The spiral end portion C of the spiral portion B is connected to the side wall surface 12 of the spiral portion B.

Note that the upper wall surface 13 of the spiral portion B is connected to a steep downward slope at the spiral end portion C.

On the other hand, as shown in FIGS. 1 to 5, a branch passage 14 having 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 to.

An inlet opening 15 of the branch passage 14 is formed on the side wall surface 9 in the vicinity of the inlet opening of the inlet passage section A, and an outlet opening 16 of the branch passage 14 is formed on the upper end of the side wall surface 12 at the spiral end C.

Furthermore, an on-off valve insertion hole 17 is bored in the cylinder head 3 and extends vertically through the branch passage 14. Inside the on-off valve insertion hole 17, there are slide valves 18 each functioning as a passage on-off valve. is inserted.

Referring to FIG. 9, the slide valve 18 includes a hollow sleeve 19 fitted into the on-off valve insertion hole 17, and a valve body which is slidably inserted into the hollow sleeve 19 and can protrude into the branch passage 14. 20 and a piston 22 coupled to the valve body 20 via a rod 21, the rod 21 being connected to the hollow sleeve 19.
It penetrates a partition wall 23 formed in the longitudinal center of the inner wall.

The hollow sleeve internal chamber 19a below the partition wall 23 is connected to the branch passage 14.
The valve body 20 is slidably inserted into the hollow sleeve internal chamber 19a.

A pair of OIJ songs 4 and 25 are inserted between the outer peripheral surface of the hollow sleeve 19 and the inner peripheral surface of the on-off valve insertion hole 17, and the partition wall 23
A sealing member 26 is mounted on top to make 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.

An air relief hole 28a is formed on the central axis of the valve body 20, and this air relief hole 28a communicates with an air relief hole 28b formed in the rod 21.

Furthermore, an air relief hole 28c is formed on the rod 21 to communicate the air relief hole 28b and the hollow sleeve internal chamber 19a, and thus the hollow sleeve internal chamber 19a between the valve body 20 and the partition wall 23 is connected to the air relief hole 28c and the hollow sleeve internal chamber 19a. Air relief hole 28E),
It communicates with the branch path 14 via 28a.

On the other hand, an opening 29 is bored in the upper part of the hollow sleeve 19, and in the embodiment shown in FIG.

An operating hydraulic chamber 30 formed between the piston 22 and the partition wall 23
communicates with an annular lubricating oil passage 32 formed around the hollow sleeve 19 via a hydraulic pressure introduction hole 31 formed in the hollow sleeve 19 .

This annular lubricating oil passage 32 is connected to an engine-driven lubricating oil supply pump (not shown) via a lubricating oil passage 33 and a lubricating oil supply passage 34.

A valve body 37 of an electromagnetic switching valve 36 is inserted into a confluence 35 between the lubricating oil passage 33 and the lubricating oil supply passage 34 , and a solenoid of the electromagnetic switching valve 36 is connected to an output terminal of an electronic control unit 38 .

As shown in FIG. 9, a circumferential groove 39 is formed on the outer peripheral surface of the valve body 37.

On the other hand, a lubricating oil return passage 40 that can communicate with the circumferential groove 39 is branched from the merging portion 35, and this lubricating oil return passage 40 is connected to a lubricating oil reservoir (not shown).

As can be seen from FIG. 9, at least a portion of the lubricating oil return passage 40 is arranged above the working hydraulic pressure chamber 30 and the lubricating oil passage 33.

The electronic control unit 38 is composed of a digital computer and includes a microprocessor (MP) that performs various arithmetic processing.
U) 50, Random access memory IJ (RAM)
51, read-only memory (ROM) 52 in which control programs, calculation constants, etc. are stored in advance, input port 53
Also, output ports 54 are connected to each other via a bidirectional bus 55.

Furthermore, a clock generator 56 is provided within the electronic control unit 38 to generate various clock signals.

A negative pressure sensor 57 is connected to the inlet port 53 via a heart transducer 58, and a rotation speed sensor 5 is connected to the inlet port 53.
9 is connected.

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
It is converted into a corresponding binary number in the D converter 58, and this binary number is sent to the MPU via the input port 53 and the bus 55.
It will be loaded in 5Q.

The rotation speed sensor 59 generates a pulse every time the crankshaft rotates by a predetermined crank angle, and this pulse is read into the MPU 50 via the input port 53 and the bus 55.

On the other hand, the output port 54 is connected to a solenoid of the electromagnetic on-off valve 36 via a power amplification circuit 60.

Figure 12 shows the engine speed N at which the electromagnetic switching valve 36 should be operated.
(r, p, m,) and negative pressure P in the intake manifold (-mm
Hg).

Note that the electromagnetic switching valve 36 is operated in the hatched area above the solid line W in FIG.

The relationship between the engine speed N and the negative pressure P shown by the solid line W in FIG.
It is stored in OM52.

The MPU 5Q calculates the engine rotation speed N from the output signal of the rotation speed sensor 59, and compares the engine rotation speed N and the output signal of the negative pressure sensor 57 representing the negative pressure P with the function W stored in the ROM 52 to determine the engine speed. When the rotational speed N and the negative pressure P are in the hatched area in FIG. 12, a drive signal is written to the output port 54.

At this time, the solenoid of the electromagnetic switching valve 36 is energized, so the valve body 37 rises as shown in FIG. The passage 40 is closed by the valve body 37.

Therefore, pressurized lubricating oil is supplied into the hydraulic pressure chamber 30 through the lubricating oil supply passage 34 and the lubricating oil passage 33, and as a result, the piston 22 rises against the compression spring 27, so that the valve body 20 It rises to open the branch path 14.

Note that air relief holes 28a, 28b and air relief hole 28c are formed in the valve body 20 and the rod 21, respectively, so that even if the valve body 20 rises, the hollow sleeve internal chamber 19a between the valve body 20 and the partition wall 23 will be closed. is not pressurized, and thus the valve body 20 can be easily raised.

Furthermore, as mentioned above, since air flows back and forth between the branch passage 14 and the hollow sleeve internal chamber 19a through the air vents 28a, 28b and the air vent 28c, fine particles in gasoline or carbon in the recirculated exhaust gas are removed. They do not enter between the outer circumferential surface of the valve body 20 and the inner circumferential surface of the hollow sleeve 19, thus preventing these fine particles and carbon from scratching the outer circumferential surface of the valve body 20. Furthermore, it is possible to prevent the valve body 20 from sticking on the hollow sleeve 19 due to cutting of the lubricating oil film caused by the accumulation of carbon or the like.

On the other hand, as mentioned above, when the piston 22 rises, the opening 2
9 opens into the hydraulic pressure chamber 30.
The lubricating oil inside flows out from the aperture 29, and as a result, the lubricating oil pressure in the hydraulic pressure chamber 30 decreases, so the piston 22 stops when the aperture 29 opens into the hydraulic pressure chamber 30.

Therefore, the opening 29 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 opening 29 can be oriented 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. 12, the solenoid of the electromagnetic switching valve 36 is deenergized, so that the valve body 37 descends as shown in FIG. do.

As a result, the lubricating oil supply passage 34 is closed by the valve body 37, and at the same time, the lubricating oil passage 33 communicates with the lubricating oil return passage 40 via the outer peripheral groove 39 of the valve body 37.

As a result, the lubricating oil in the hydraulic pressure chamber 30 flows out through the lubricating oil return passage 40, so that the piston 22 descends and the waist valve body 20 blocks the branch passage 14.

As mentioned above, the lubricating oil return passage 40 is provided above the lubricating oil passage 33 and the hydraulic pressure chamber 30, so even when the piston 22 reaches the lowest position, the lubricating oil passage 33 and the hydraulic pressure chamber 30 are filled with lubricating oil. filled with.

Therefore, when the electromagnetic switching valve 36 is energized again, the inside of the hydraulic pressure chamber 30 can be pressurized immediately, and thus the branch passage 14 can be opened immediately.

In FIG. 12, the hatched area indicates a region where the amount of intake air is large. Therefore, when the amount of intake air is large, the slide valve 18 opens, and when the amount of intake air is small, the slide valve 18 closes. I understand.

As described above, the sliding valve 18 blocks the branch passage 14 during low-speed engine load operation with a small amount of intake air.

At this time, the air-fuel mixture sent into the inlet passage part A descends inside 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.
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 opens, so that a part of the air-fuel mixture sent into the inlet passage A flows through the branch passage 14 with low flow resistance to the spiral part B. sent inside.

The air mixture flowing along the upper wall surface 13 of the spiral portion B is deflected downward by the steeply inclined wall of the spiral end portion C, so that the flow path is deflected downward at the spiral end portion C1, that is, the outlet opening 1 of the branch passage 14.
6, a large negative pressure is generated.

Therefore, since the pressure difference between the inlet passage part A and the spiral end part C is large, when the slide valve 18 opens, a large amount of air-fuel mixture flows into the branch passage 14.
It is sent into the spiral part B through.

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 allows a large amount of intake air to flow into the spiral portion B via the branch path 14 with low flow resistance. Since the fuel is fed in, high filling efficiency can be ensured.

Furthermore, by providing the inclined surface 9a in the inlet passage A, a part of the air-fuel mixture sent into the inlet passage A is given a downward force, and as a result, this air-fuel mixture is not swirled and is transferred to the inlet passage A. Since the fluid flows into the spiral portion B along the lower wall surface of the fluid, the flow resistance becomes small, and thus the filling efficiency during high-speed, high-load operation can be further improved.

Another embodiment of the sliding valve 18 is shown in FIG.

In this embodiment, a through hole 70 having a larger diameter than the rod 21 is formed in the valve body 20, and a pin 71 that can engage with the lower end surface of the valve body 20 is fixed to the lower end of the rod 21.

Therefore, also in this embodiment, the hollow sleeve internal chamber 19a is always in communication with the branch passage 14 through the through hole 70, so that the valve body 2
0 can be easily raised, and furthermore, it is possible to immediately prevent the valve body 20 from sticking to the hollow sleeve 19.

Further, in this embodiment, even if the axis of the rod 21 and the axis of the valve body 20 are slightly misaligned, the sliding resistance of the rod 21 does not increase, and therefore the valve body 20 can be easily operated.

As described above, according to the present invention, it is possible to control the opening and closing of branch passages with a simple mechanism using the lubricating oil pressure inherent in the engine, thereby improving reliability and reducing manufacturing costs. can.

Furthermore, by providing an air relief hole in the valve body, the valve body can be operated easily, and by providing an air relief hole in the center of the valve body, when the valve body moves up and down, the air can move back and forth within the hole. However, it does not flow through the minute gap between the valve body and the inner peripheral surface of the hollow sleeve.

Therefore, fine particles contained in gasoline and carbon in recirculated exhaust gas do not enter between the outer peripheral surface of the valve body and the inner peripheral surface of the hollow sleeve, so these fine particles and carbon do not damage the outer peripheral surface of the valve body. In addition, it is possible to prevent the valve body from sticking to the hollow sleeve due to cutting of the lubricating oil film caused by the accumulation of these fine particles and carbon.

Further, 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 lubricating oil return passage is located above the working hydraulic pressure chamber, the working hydraulic pressure chamber is always filled with lubricating oil, and therefore, when the electromagnetic switching valve is switched, the branch passage can be immediately opened. .

[Brief explanation of drawings]

Fig. 1 is a plan view of an internal combustion engine according to the present invention, and Fig. 2 is a plan view of an internal combustion engine according to the present invention.
Figure 3 is a perspective view showing the shape of the helical intake port, Figure 4 is a plan view of Figure 3, Figure 5 is a branch of Figure 3. 6 is a sectional view taken along the line IV--IV in FIG. 4, FIG. 7 is a sectional view taken along the line ■-■ in FIG. 4, and FIG.
The figure is a sectional view taken along the line ■-■ in Figure 4, Figure 9 is an overall view of the flow path control device, Figure 10 is a diagram showing a part of Figure 9, and Figure 11 is a slide valve. 12th side cross-sectional view of another embodiment of
The figure shows the opening area of the slide valve. 5... Intake valve, 6... Helical intake port, 14... Branch path, 18... Sliding valve, 19... Hollow sleeve, 20...
・Valve body, 22...Zeston, 28at28b...
...Air relief hole, 28c... Air relief hole,
30...Operating hydraulic chamber

Claims (1)

[Scope of utility model registration request] In a helical intake port configured with a spiral portion formed in the intake valve body and an inlet passage portion that is tangentially connected to the spiral portion and extends almost straight, the spiral portion is branched from the inlet passage portion and is connected to the spiral portion. A branch passage communicating with the spiral terminal end of the part is formed in the cylinder head, an on-off valve insertion hole extending vertically across the branch passage is formed in the cylinder head, and a hollow sleeve is inserted into the on-off valve insertion hole. The upper end portion of the rond is inserted into the hollow sleeve to form a partition wall in the longitudinal center portion of the hollow sleeve, opens the internal chamber of the hollow sleeve below the partition wall into the branch passage, and extends in the vertical direction of the partition wall through the partition wall. is connected to the piston to form an operating hydraulic chamber connectable to a hydraulic power source between the partition wall and the piston, and a valve body that can protrude into the branch passage is slidably inserted into the hollow sleeve internal chamber, and the valve body is connected to the lower end of the rond, and the internal chamber of the hollow sleeve between the valve body and the partition wall is communicated with the branch passage through an air relief hole formed in the center of the valve body. Control device.