JPS6026183Y2 - 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 is usually comprised of a spiral portion shaped at the intake station and an inlet passageway tangentially connected to the spiral portion and extending substantially straight.

This type of helical intake port is used to generate a strong swirling flow within the engine combustion chamber during high-speed, high-load operation of the engine 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 passage is formed in the cylinder head that branches from the helical intake port inlet passage and communicates with the spiral end of the helical intake port spiral part, and an actuator is inserted into the branch passage. This is a helical intake port flow path control device that is equipped with a normally closed on-off valve that operates, and when the amount of engine intake air exceeds a predetermined amount, an actuator is activated to open the on-off valve. Already proposed by the applicant.

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 FIGS. 1 and 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 block 1; 4 is a combustion chamber formed between the piston 2 and the cylinder 6; 5 is an intake valve; 6 is a helical intake port formed in 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 port 6 of FIG. 2.

As shown in FIG. 4, this helical intake port 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 of the inlet passage A
is formed on 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 the figure, the entire side wall surface 9 is formed into a downwardly oriented inclined surface 9a.

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 port 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 inclined surface 9 near the entrance opening of the inlet passage section A, and serves as an exit of the branch passage 14 .

The opening 16 is formed at the upper end of the inclined 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 slidably inserted into the hollow sleeve 19 and protruding 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.

A hollow sleeve internal chamber formed in the hollow sleeve 19 below the partition wall 23 opens into the branch passage 14, and the valve body 20 is slidably inserted into the hollow sleeve internal chamber.

A pair of O-rings 24 and 25 are inserted between the outer circumferential surface of the hollow sleeve internal chamber 19 and the inner circumferential surface of the on-off valve insertion hole 17, and a sealing member 2 on the partition wall 23 is in sealing contact with the rod 21.
6 is installed.

A compression spring 27 is inserted between the valve body 20 and the partition wall 23 to constantly press the valve body 20 downward. A plurality of air relief grooves 28 extend spirally over the entire length in the direction.
is formed.

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.

The working oil pressure 30 formed between the piston 22 and the partition wall 23 passes through a hydraulic pressure introduction hole 31 formed in the hollow sleeve 19 to an annular lubricating oil passage 32 formed around the hollow sleeve 19.
It will be communicated to.

This annular lubricating oil passage 32 communicates via an annular lubricating oil passage 33 with a collective passage 34 that communicates with the slide valves 18 of each cylinder.

The collective passage 34 is connected to an engine-driven lubricating oil supply pump (not shown) via a lubricating oil supply passage 35 extending downward, 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 electronic control unit 38. connected to the output terminal of

On the other hand, the collective passage 34 has a lubricating oil return passage 39 extending upward.
, is connected to a lubricating oil reservoir (not shown) via a throttle passage 40 having a small cross-sectional area and a lubricating oil return passage 41.

As can be seen from FIG. 9, the throttle passage 40 is arranged above the collective passage 40 and above the hydraulic pressure chamber 30.

The electronic side m unit 38 is composed of a digital computer, and includes a microprocessor (MP) that performs various arithmetic operations.
U) 50, Random access memory IJ (RAM) 5
A read-only memory (ROM) 52 in which L control programs, calculation constants, etc. are stored in advance, an input port 53, and an output port 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, and a converter 58 is connected to the inlet port 53.
Further, a rotation speed sensor 59 is connected to the inlet port 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. as well as MP via bus 55.
Loaded into U5Q.

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 the wire of the electromagnetic on-off valve 36 via a power amplification circuit 60.

Figure 11 shows the engine speed N at which the electromagnetic on-off valve 36 should be operated.
(r, p, m,) and negative pressure P in the intake manifold (-mm
Hg).

Note that the electromagnetic on-off 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.

IV! In the PU5Q, the engine rotation speed N is calculated from the output signal of the rotation speed sensor 59, and this engine rotation speed N and the output signal of the negative pressure sensor 57 representing the negative pressure P are compared with the function W stored in the ROM 52 to determine the engine speed. The rotation speed N and negative pressure P are the 11th
When in the hatched area in the figure, a drive signal is written to the output port 54.

At this time, the solenoid of the electromagnetic on-off valve 36 is energized, so the electromagnetic on-off valve 36 is opened, and as a result, the pressurized lubricating oil is supplied to the lubricating oil supply passage 37, the electromagnetic on-off valve 36, and the lubricating oil supply passage. 35 into the collecting passage 34.

This lubricating oil is then returned to the lubricating oil reservoir via the throttle channel 40 and the lubricating oil return channel 41 on the one hand, and flows into the hydraulic pressure chamber 30 via the annular lubricating oil channel 32 on the other hand.

At this time, since the cross-sectional area of the throttle passage 40 is quite small, the pressure inside the collective passage 40 is quite high, and therefore the piston 22 rises against the compression spring 27, causing the valve body 20 to rise and open the branch passage 14. .

As mentioned above, since the spiral air relief groove 28 is formed on the outer peripheral surface of the valve body 20, when the valve body 2o rises, air flows from the internal chamber of the hollow sleeve 19 into the air relief groove 28. The airflow ejected into the branch passage 14 exerts a rotational force on the valve body 20, and as a result, the valve body 20 is rotated within the hollow sleeve 19.

When the valve body 20 is rotated in this manner, the outer circumferential surface of the valve body 20 and the inner circumferential surface of the hollow sleeve 19 are well lubricated.
In this way, it is possible to prevent the valve body 2o from sticking to the hollow sleeve 19 due to cutting of the lubricating oil film caused by the accumulation of particulates in gasoline or carbon in the recirculated exhaust gas.

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 opening 29, and as a result, the lubricating oil pressure in the hydraulic pressure chamber 30 decreases, so the piston 22 stops when the opening 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. 11, the solenoid of the electromagnetic on-off valve 36 is deenergized, so the electromagnetic on-off valve 36 closes.

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, the piston 2
2 reaches the lowest position, the collective passage 34 and the hydraulic pressure chamber 30 are filled with lubricating oil.

Therefore, when the electromagnetic on-off valve 36 opens again, the operating hydraulic pressure chamber 3
0 can be pressurized immediately, and thus the branch passage 14 can be opened immediately.

The hatched area in FIG. 11 indicates a region where the amount of intake air is large. Therefore, when the amount of intake air is large, the slide valve 18 is opened, but when the amount of intake air is small, the slide valve 18 is opened. It can be seen that the valve closes.

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

At this time, the air-fuel mixture sent into the inlet passage A swirls along the soil wall surface 13 of the swirl section B, descends inside the swirl section B, and then flows into the combustion chamber 4 while swirling. A strong swirling flow is generated.

On the other hand, when the engine is operated at low speed and under low load with a large amount of intake air, the sliding valve 18 opens, so that 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 way, 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 portion of the air-fuel mixture sent into the inlet passage A is given a downward force, and as a result, this air-fuel mixture flows through the inlet passage A without swirling. Since the fluid flows into the spiral portion B along the lower wall surface, 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, 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.

In addition, by forming a spiral groove on the outer circumferential surface of the valve body of a sliding valve, when the valve body rises, the air inside the hollow sleeve is blown out into the branch passage through the air relief groove. The air applies rotational force to the valve body, causing the valve body to rotate within the hollow sleeve.

When the valve body is rotated in this manner, the lubricating oil is spread over the entire inner circumferential surface of the hollow sleeve, so that the lubricating oil film is not cut due to the accumulation of particles in gasoline or carbon in recirculated exhaust gas. In this way, it is possible to immediately prevent the valve body from sticking to the hollow sleeve of the sliding valve.

Furthermore, by employing hydraulic control using lubricating oil pressure, the size of the slide valve can be reduced, so it can be easily installed in a cylinder head with limited space.

Furthermore, since the piston-actuating hydraulic chamber of the sliding valve is always in communication with the lubricating oil reservoir via the lubricating oil return throttle passage, even if a leak occurs in the electromagnetic on-off valve, the leaked pressurized lubricating oil will flow through the restricting passage. Since the lubricating oil is returned to the lubricating oil reservoir through the lubricating oil reservoir, the sliding valve will not malfunction, and since the throttle passage is located above the operating hydraulic pressure chamber, the operating hydraulic pressure chamber will always be filled with lubricating oil.
Therefore, when the electromagnetic on-off valve opens, the branch path can be opened immediately.

[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.
is a sectional view taken along the line ■-■ in Fig. 4, Fig. 9 is an overall view of the flow path control device, Fig. 10 is a sectional view taken along the line X-X in Fig. 9, and Fig. 11. FIG. 2 is a diagram showing an opening area of a sliding valve. 5... Intake valve, 6... Helical intake port, 14... Branch path, 18... Sliding valve, 20... Valve body, 28... Air relief hole.

Claims (1)

[Scope of utility model registration request] In a helical intake port configured with a spiral part formed in the intake valve body and an inlet passage part connected tangentially to the spiral part and extending almost straight, the above-mentioned part is branched from the inlet passage part. A branch path that communicates with the spiral end of the spiral portion is formed in the cylinder head, and an on-off valve insertion hole that extends vertically across the branch path is formed in the cylinder head, and the on-off valve insertion hole is inserted into the on-off valve insertion hole. A hollow sleeve is inserted, a partition wall is formed in the longitudinal center of the hollow sleeve, and an internal chamber of the hollow sleeve below the partition wall is opened into a branch passage, which extends in the vertical direction of the partition wall through the partition wall. The upper end of the rond is connected to the piston to form an operating hydraulic chamber between the partition wall and the piston, which can be connected to a hydraulic power source, and a valve body capable of protruding into the branch passage is slidably inserted into the internal chamber of the hollow sleeve. At the same time, the valve body is connected to the lower end of the rond, and a spiral groove extending over the entire length in the longitudinal direction is formed on the outer peripheral surface of the valve body to form an internal chamber of the hollow sleeve between the valve body and the partition wall. A flow path control device for a helical intake port that communicates with the branch path through the spiral groove.