JPS5828525A - Flow-passage controller for helical-type intake port - Google Patents

Abstract

PURPOSE:To secure high charging efficiency and permit a suitable swirling flow to be generated in the combustion chamber of an engine by specifying the position of the opening on the inlet passage part side of the branched passage which connects the inlet passage part to the swirl-terminating part of the captioned port. CONSTITUTION:A helical-type intake port 6 consists of the swirl part B formed around an intake valve 5 and the inlet passage part A which is connected in tangential form to the swirl part B and extends nearly straight, and formed in a cylinder head 3. The branched passage 14 which connects the inlet passage part A to the swirl-terminating part C is formed in the cylinder head 3, and the inlet opening of the branched passage 14 is arranged in the vicinity of the upper wall surface of the inlet passage part A. In the branched passage 14, an ON/OFF-valve (slide valve) 17 which moves corresponding to the amount of the air taken-in installed. Further, the inlet opening of the inlet passage part A is connected to the curved intake pipe 24 which extends downward from a surge tank 25 and is directed upward again.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a helical intake-part flow path control device.

Helical intake? The vent is usually constituted by a volute formed between the intake valves and an inlet passage tangentially connected to the volute and extending substantially directly into the volute. If an attempt is made to use this type of helical intake to generate a strong swirling flow within the combustion chamber of the engine during low-speed, low-load operation of the engine with a small amount of intake air, the shape of the intake port will have a large flow resistance. Therefore, there is a problem that charging efficiency decreases when the engine is operated at high speed and under high load with a large amount of intake air.

In order to solve this problem, a branch path that branches from the helical intake port inlet passage and communicates with the spiral end of the helical intake tate spiral section is formed inside the cylinder, and an actuator is inserted into the branch path. A helical intake port flow path that is equipped with a normally closed on-off valve that is activated, and when the amount of engine intake air exceeds a predetermined amount, the actuator is actuated to open the on-off valve. A control device has already been proposed by the applicant. With this helical intake port, during engine high-speed, high-load operation with a large amount of engine intake air, a portion of the intake air sent into the helical intake port entrance passage is routed through the branch path into the helical! ! !
! The flow resistance to the intake air flow is reduced due to the intake air being fed into the volute (-), and thus a high filling efficiency can be obtained. However, this flow path control device only shows the basic operating principle, and therefore, in order to generate an optimal swirl flow in the engine combustion chamber while ensuring high charging efficiency, it is necessary to must be placed optimally.

An object of the present invention is to provide a flow path control device that can generate an optimal swirl flow within an engine combustion chamber while ensuring high charging efficiency.

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 pro;
2 is a piston that reciprocates within the cylinder block 1;
3 is the cylinder dog mouth, which is fixed on 1 and goes to the next cylinder, 4 is the piston 2 and cylinder, the combustion chamber formed between 3, 5 is the intake valve, and 6 is formed inside the cylinder head 3. 7 shows the helical intake port, 7 shows the exhaust valve, 8 shows the cylinder, and the exhaust port formed in the door 3, respectively. Although not shown in the figure, an ignition plug is disposed within the combustion chamber 4.

Figure 3 and Figure 4 show the helical type intake shown in Figure 2/-)6
The shape of is shown diagrammatically. 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 side wall surface 9 of the inlet passage A near the spiral axis
The upper side wall surface 9& is formed as a downwardly facing inclined surface, 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 and the spiral part B, as shown in FIG. As shown, 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 the intake valve guide 1
The cylindrical protrusion 110 formed on the upper wall surface of the intake port around 0 (Fig. 2) is smoothly connected to the surrounding wall surface, and the lower half of the measured wall surface 9 is connected to the spiral end portion C of the spiral portion B at the spiral portion B. is connected to the side wall surface 12 of. Incidentally, the upper wall surface 13 of the spiral portion B is connected to the downward steeply inclined wall DK at the spiral end portion C.

On the other hand, as shown in FIGS. 1 to 5, a branch passage 14 having a rectangular cross section is formed in the cylinder head 3, branching from the inlet passage part, and this branch passage 14 is connected to the spiral terminal part C. be done. The inlet opening 15 of the branch passage 14 is formed on the side wall surface 9 near the upper wall surface of the inlet passage part in the vicinity of the entrance opening of the inlet passage part A, and the outlet opening 16 of the branch passage 14 is formed on the upper end of the side wall surface 12 at the spiral terminal part C. formed in the part.

A slide valve 17 for controlling the flow area of the branch passage 14 is slidably inserted into the branch passage 14 .

A valve port and door 18 are integrally formed at the upper end of the slide valve 17, and the upper end of this valve port and door 18 protrudes upward into the cylinder through a guide sleeve 19 fitted in the door 3. . On the other hand, an arm rod 20 is rotatably attached to the cylinder head 3 via a bearing (not shown), and an arm 21 provided for each slide valve 17 of each cylinder is fixed onto the arm rod 20. . The tip of each of these arms 21 is attached to the head of the corresponding valve rod 18.
, are pivotally connected via the toppin 22. Incidentally, another arm 23 is fixed to the arm rod 20, and the tip of this arm 23 is connected to the diaphragm 31 of the negative pressure diaphragm device 30.
The control rod 32 is connected to a control rod 32 fixed to the control rod 32 . As shown in FIG. 2, an intake pipe 24 is connected to the inlet opening of the intake port 60, and this intake pipe 24 communicates with the atmosphere via a surge tank 25 common to each cylinder and an air flow meter (not shown). A fuel injection valve 26 is attached to the cylinder head joint of each intake pipe 24, and fuel is injected into each intake air 6 from these fuel injection valves 26. Intake pipe 24 line intake as shown in Figure 2? - It has a curved shape that extends downward from the inlet opening i of the inlet passage section A of the Toro, then turns upward again to be connected to the surge tank 25 and hangs downward. Modern cars tend to have lower vehicle heights and therefore lower engine hoods, so the surge tank 25 has to be lowered in position, but even in such cases, intake inertia can be used to improve low-speed torque. In this case, the intake pipe 24 needs to have a certain length, and thus the intake pipe 24 has a curved structure as shown in FIG.

On the other hand, referring again to FIG. 10, the negative pressure diaphragm device 30 includes a negative pressure chamber 34 isolated by a diaphragm 31.
and an atmospheric pressure chamber 33, and a compression spring 35 for pressing the diaphragm is inserted into the negative pressure chamber 34. This negative pressure chamber 34 is supplied with negative pressure via a negative pressure conduit 36 and an electromagnetic control valve 37.
It is connected to the mulator 29. The electromagnetic control valve 37 has a valve chamber 38
and a negative pressure port 39 communicating with the negative pressure accumulator 29.
, a valve body 41 that controls the opening and closing of the negative pressure 39 and the atmosphere /-) 40 communicating with the atmosphere, a movable granger 42 connected to the valve body 41, and a movable granger suction This solenoid 43 is connected to an output terminal of an electronic control unit 50. On the other hand, the negative pressure accumulator 29 is connected to the intake pipe 24 via a check valve 45 that allows flow from the negative pressure accumulator 29 only toward the intake pipe 24 . The check valve 45 opens when the negative pressure in the intake pipe 24 becomes larger than the negative pressure in the negative pressure accumulator 29. Since the valve closes when the negative pressure accumulator 29 becomes smaller, the negative pressure in the negative pressure accumulator 29 is maintained at the maximum negative pressure generated in the intake pipe 24. On the other hand, a negative pressure sensor 46 for detecting negative pressure in the intake pipe 24 is attached to the intake pipe 24, and the negative pressure sensor 46 is connected to the electronic control unit 5.
Connected to the 0 input terminal. Further, a 4-tension meter 47 for detecting the opening area of the slide valve 17 is attached to the arm rod 20. This deten, meter 4
7 is composed of a slider 47m connected to the arm rod 20 and rotating together with the arm rod 20, and a fixed resistor 47b, and the slider 47m slides on the fixed resistor 47b while contacting it. Therefore, a voltage proportional to the opening area of the slide valve 17 is generated in the slider 47m. This slider 47m
is connected to the input terminal of the electronic control unit )50. On the other hand, a rotation speed sensor 48 is connected to an input terminal of an electronic control unit 50 to detect the rotation speed of the engine crankshaft.

The electronic control unit 50 is a digital combination, a microprocessor (MP) that performs various arithmetic processing, and
U) 51, a random access memory (RAM) 52, a read-only memory (ROM) 53 in which control programs and calculation constants are stored in advance, an input port 54, and an output port sg are interconnected via a bidirectional path 56. It is connected to the. Further, within the electronic control unit 50, there is provided a black and white generator 57 that generates various black and white signals.

As shown in FIG. 10, the input port 54 is connected to the negative pressure sensor 46 and ? Tension meter 47 is connected and input on page /-)5
4 is connected to a rotation speed sensor 48. Negative pressure sensor 46
generates an output voltage proportional to the negative pressure in the intake pipe 24, this voltage is converted into a corresponding binary number in the AD converter 58, and this binary number is read into the MPU 51 via the input port 54 and path 56. It will be done. On the other hand, the potentiometer 47 generates an output voltage proportional to the opening area of the slide valve 17, and this voltage is converted into a corresponding binary number by an AD converter 59, and this binary number is sent to the MPU 51 via an input port 54 and a path 56. is loaded into. Also,
The rotation speed sensor 48 generates a rotational pulse every time the crankshaft rotates by a predetermined crank angle, and this rotational pulse is read into the MPU 51 via an input port 54 and a path 56.

The output port 55 is provided to output data for operating the electromagnetic control valve 37.
5, binary data is written from the MPU 51 via a path 56. Each output terminal of the output/-) 55 is connected to a corresponding input terminal of the down counter 60. The down counter 60 is provided at the ninth position to convert the binary data written from the MPU 51 into the corresponding time length. Counting is started by the clock signal of the clock generator 57, and when the count value reaches 0, the counting is completed and the signal is output to the output terminal.
Generates a count completion signal. The reset input terminal 8 of the S-B flipflop 1 is connected to the output terminal of the down counter 60, and the set input terminal S of the S-R flipflop 61 is connected to the clock generator 57. 5-R
7s.

The counter 1 is set at the same time as the down count starts by the clock signal from the clock generator 57, and is reset by the count completion signal from the down counter 6° when the down count is completed. Therefore, 5-R7, f flow,
The output terminal Q of the pin 61 is at a high level while the down count is being performed. The output terminal Q of the 5-R7 flip-flop 61 is connected to the electromagnetic control valve 37 via a power amplification circuit 62. Therefore, the solenoid 4 of the electromagnetic control valve 32
3 is activated while the down count is being performed.

When the solenoid 43 of the electromagnetic control valve 37 is deenergized, as shown in FIG. The inside of the negative pressure chamber 34 becomes atmospheric pressure. At this time, the diaphragm 31 is at the left end position due to the spring force of the compression spring 35, so the slide valve 17 closes the branch passage 14. On the other hand, when the solenoid 43 of the electromagnetic control valve 37 is energized, the valve body 41 closes the atmosphere/-) 40 and opens the negative pressure port 39, so there is no negative pressure inside the negative pressure chamber 34 of the negative pressure diaphragm device 30. The pressure is released, and negative pressure inside the mullet 29 is applied. At this time, the diaphragm 31 moves to the right against the compression spring 35, causing the slide valve 17 to rise, thereby fully opening the branch passage 14.

As mentioned above, the solenoid 43 of the electromagnetic control valve 37 is energized while the down count is being performed, that is, when the voltage appearing at the output terminal Q of the 5-R7 flip-flop 61 is at a high level. Therefore, the proportion of time during which the valve body 41 of the electromagnetic control valve 37 opens the negative pressure port 39 and closes the atmospheric pressure port 40 is proportional to the duty cycle of A/lus applied to the solenoid 43. The longer the time period for which the valve body 41 opens the negative pressure/-) 39 and closes the atmosphere (-) 40, the greater the negative pressure in the negative pressure chamber 34 of the negative pressure diaphragm device 30 becomes, and the slide valve 17 increases. The opening area becomes larger. Therefore, the opening area of the slide valve 17 is equal to that of the solenoid 43.
It can be seen that the Noculus duty cycle applied to becomes larger as the duty cycle becomes larger.

Figure 13 shows the opening area of the slide valve 17 and the engine speed N.
It also shows a preferable relationship with the intake pipe negative pressure P. In Fig. 13, the vertical axis is the engine speed N (r, p, m)
, and the horizontal axis indicates the intake pipe negative pressure P (-■Hg). In addition, the upper region of the hatched curve S1 indicates the slide valve fully open region, the lower region of the hatched curve S1 indicates the slide valve fully closed region, and the curve 8m+SI, of which only two representative curves are shown, indicates the slide valve fully open region. The iso-opening area curve of the valve is shown. In addition, in FIG. 13, the opening area of the slide valve is S! From 8! It gradually increases as it goes from +Sm to So. The preferred relationship between the engine speed N, the intake pipe negative pressure P, and the opening area S of the slide valve shown in FIG.
53.

FIG. 11 shows a 7p-chart for explaining the operation of the flow path control device according to the present invention. In FIG. 11, step 70 indicates that flow path control is performed by time interruption. First, in step 71, the output signal of the rotation speed sensor 48 is input into the MPU 51 to calculate the engine rotation speed, and then, in step 72, the output signal of the negative pressure sensor 46 is input into the MPU 51. . Next, in step 73, the target opening area SS of the slide valve 17 is calculated based on the calculated engine speed N and negative pressure P from the relationship shown in FIG. 13 stored in the ROM 53.

Next, at step 4, the output signal of potentiometer 47 is input into MPU 51, and the current slide valve 1 is input.
Calculate the opening area S of No.7. Next, in step f75, it is determined whether the target opening area SS is larger than the current opening area S.

When it is determined in step 75 that the target opening area BS is larger than the current opening area S, in step 76, the nose width PL of the nose to be applied to the solenoid 43 of the electromagnetic control valve 37 is set to a constant value. The number of people is added, and the process proceeds to step 77 with the addition result set as PL. On the other hand, if it is determined in step 75 that the target opening area SS is not larger than the current opening area S, the process proceeds to step 78.
In step 781C, it is determined whether the target opening area ss is smaller than the current opening area S. Ste.

If step 78 determines that the target aperture area ss is smaller than the current aperture area S, step 7 #79 subtracts a constant value A from the nose width PL, and sets this subtraction result as PL. Proceed to.

On the other hand, when it is determined that the target aperture area ss is not smaller than the current aperture area S in step 8, step 8
Proceed to fl7. In step 77, fl
/? Outputs binary drive data representing the lasing width PL/-
) 55, and based on the drive data written in the output date 55, the energization control of the solenoid 43 of the electromagnetic control valve 37 is performed.

FIG. 12 shows the /4 pulse applied to the solenoid 43 of the electromagnetic control valve 37, and this I? The solenoid 43 is energized while the pulse is occurring. As described above, when the current opening area S of the slide valve 17 is smaller than the target opening area SS, the pulse width is sequentially increased by a constant width until the opening area reaches the target opening area SSK, as shown in FIG. Therefore, since the duty cycle of Noyals applied to the solenoid 43 gradually increases, the negative pressure in the negative pressure chamber 34 of the negative pressure diaphragm device 30 gradually increases, and the slide valve 17 rises to reach the target. The opening area becomes SS. As shown in Figure 13, when the engine is running at low load and low speed, when the engine is running at high load and at low speed, and when the engine is running at low load and high speed, the
The solenoid 43 continues to be deenergized because the output voltage continues to be at a low level, so that the slide valve 17 continues to close the branch passage 14. On the other hand, during engine high-speed, high-load operation, the output voltage of 5-R7, Zoflo, and f61 remains at a high level, so the solenoid 43 continues to be energized.
In this way, the slide valve 17 continues to fully open the branch passage 14.

As mentioned above, the slide valve 17 shuts off the branch passage 14 when the engine is operating at low load and low speed with a small amount of intake air, when the engine is operating at high load and low speed, and when the engine is operating at low load and high speed. At this time, the air sent into the inlet passage 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, resulting in combustion. A strong swirling flow is generated within the chamber 4. On the other hand, during engine high-speed, high-load operation with a large amount of intake air, the slide valve 17 opens, so a part of the air sent into the inlet passage A flows into the branch passage 14 through the inlet opening 15, and then This air flows into the volute B through the branch passage 14. Second
If the intake pipe 24 is curved as shown in the figure, the intake pipe 24
Inhalation from? - The air sent into the trolley is pushed toward the upper wall of the intake port 6 by centrifugal force as shown by arrow W, and as a result, the pressure inside the intake port is lower on the upper wall than on the lower side. It gets expensive. In the present invention, since the branch passage 140 inlet opening 15 is disposed near the upper wall surface of the intake port where the pressure is high, the branch passage 140 inlet opening 1
5 and the outlet opening 16 becomes large, and when the slide valve 17 opens, a large amount of air is sent into the volute B through the branch passage 14. In this manner, when the engine is operated at high speed and under high load, the slide valve 17 opens, which not only increases the overall flow path area, but also sends a large amount of intake air into the volute B through the branch path 14 with low flow resistance. Since it is filled in, high filling efficiency can be ensured.

Further, by providing the inclined side wall portion 9 in the inlet passage A, a portion of the air sent into the inlet passage A is given a downward force, and as a result, this air 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.

On the other hand, in FIG. 13, the song 1i 8 t and the curve 800
In the region in between, the opening area of the slide valve 17 gradually increases from curve S1 through Sl+8m toward curve 80, that is, as the intake air amount increases. When the amount of intake air is small, it is necessary to generate strong turbulence in the combustion chamber 4 in order to ensure stable combustion, but as the amount of intake air increases, the naturally occurring turbulence becomes stronger, so it is more It is necessary to suppress forced turbulence such as swirling flow, and it is also necessary to prevent a decrease in charging efficiency that causes a decrease in output as the amount of intake air increases. Therefore, by gradually increasing the opening area of the slide valve 17 as the amount of intake air increases, the generation of swirling flow can be suppressed and a decrease in filling efficiency can be prevented, thereby achieving the optimal swirling flow according to the amount of intake air. and high filling efficiency can be ensured.

As described above, according to the present invention, a strong swirling flow can be generated in the combustion chamber when the engine is operated at low speed and low load, when the engine is operated at high speed with low load, and when the engine is operated at high load and low speed, so that stable combustion can be ensured. With this, the occurrence of knocking can be suppressed, especially when the engine is operated at high load and low speed.

Further, when the engine is operated at high speed and under high load, it is possible to ensure high charging efficiency while suppressing the generation of swirling flow, so that high output can be obtained. Furthermore, when the engine is operated at medium load and medium speed, it is possible to obtain an optimal swirling flow that is weakened as the amount of intake air increases and high charging efficiency.

[Brief explanation of the drawing]

FIG. 1 is a plan view of an internal combustion engine according to the present invention, and FIG.
Figure 3 is a perspective view showing the shape of the helical intake valve, Figure 4 is a plan view of Figure 3, Figure 5 shows the branch path in Figure 3. 6 is a sectional view taken along the line MM in FIG. 4, FIG. 7 is a sectional view taken along the line ■-■ in FIG. 4, and FIG. Fig. 4 is a sectional view taken along line ■-■, Fig. 9 is a sectional view taken along line -■ in Fig. 5, Fig. 10 is an overall view of the flow path control device, Fig. 11 is a 70-chart for explaining the operation of the flow path control device, Fig. 12 is a line diagram showing the nodal force applied to the solenoid of the electromagnetic control valve, and Fig. 13 is a diagram showing the opening area of the slide valve. be. 5... Intake valve, 6... Helical intake valve, 14
... Branch passage, 17 ... Slide valve, 18 ... Valve shaft, 24 ... Intake pipe, 25 ... Surge tank, 26
... fuel injection valve, 30 ... negative pressure diaphragm device,
37... Solenoid control valve, 50... Electronic control unit y). Patent Applicant Toyota Motor Corporation Patent Application Agent Patent Attorney Akira Aoki Patent Attorney Kazuyuki Nishidate Patent Attorney Masayuki Yoshida Patent Attorney Akira Yamaguchi 1st 40th 50th 60th 7th 120th 13th P (-mmHg)

Claims (1)

[Claims] In a helical intake formed by a spiral part formed on the side of the intake valve and an inlet passage part connected tangentially to the spiral part and extending almost straight, the intake passage is branched from the inlet passage part. A branch passage communicating with the spiral terminal end of the spiral part is formed inside the cylinder, and an inlet opening of the branch passage is disposed near the upper wall surface of the inlet passage, and the branch passage is configured to respond to the amount of intake air. A helical type intake-part flow path control device which is provided with an on-off valve and further connects the inlet opening of the inlet passage portion to an intake pipe extending downward.