JPS63179136A - Suction device for engine - Google Patents

Abstract

PURPOSE:To improve a suction control effect during low speed low load running and a high speed output, by a method wherein during low speed low load running, with a control valve closed, intake air is fed through a main intake air passage with the aid of a timing valve, and during high speed high load running, with the control valve opened, intake air is also fed through an auxiliary intake air passage. CONSTITUTION:During low speed low load running, an auxiliary intake air passage 14 is closed by a control valve 18, and intake air is fed to an actuating chamber 5 only through a main intake air passage 13 by means of a main suction port 6. In this case, a timing valve 15 is situated in the main intake air passage 13 between a surge tank 12 and the main suction port 6. Meanwhile, during high speed high load, the control valve 18 is opened through a 3-way solenoid valve 21 and a first actuator 19 by means of a control unit 29, and intake air is fed to the actuating chamber 5 through an auxiliary suction port 7 also. A communicating valve 24 of a communicating passage 23 is opened through a 3-way solenoid valve 27 and a third actuator 25 through the working of the control unit 29, and filling efficiency is improved through propagation of a pressure wave.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an intake system for an engine equipped with a timing valve in an intake passage.

(Prior Art) Conventionally, there has been an intake system in which a timing valve is provided in the intake passage of an engine, and the opening/closing timing of the timing valve is adjusted separately from the intake valve to perform intake ffi III m. It is publicly known as seen in Publication No. 58-55329.

In the above precedent example, when the load is low or when knocking occurs, the timing valve is closed earlier than the intake valve to reduce the amount of intake air, and the intake air to the combustion chamber is reduced during the latter half of the intake stroke when the intake valve is open. This prevents the inhalation of gas, reduces pumping loss, and suppresses knocking due to a reduction in the compression ratio.

On the other hand, a timing valve is installed in the natural intake passage of the engine, and the timing valve is opened later than the intake valve opening timing (the timing valve is opened (the negative pressure at the initial stage of intake is increased, and the intake valve is opened accordingly). Inertia effect technology has also been proposed for so-called late opening, which increases the pressure at the end of the stroke and increases the intake air filling efficiency.

(Problem to be solved by the invention) However, if a timing valve is installed in the intake passage as described above and the pressure fluctuations in the intake passage are used to improve the intake air filling efficiency, When filling a large amount of the intake surface as in a high load area, the timing valve creates intake resistance, so a large timing valve is required, and this large timing valve has the problem of increasing mechanical resistance and driving resistance. .

It is also conceivable to provide a bypass passage that bypasses the timing valve and open this bypass passage to supply intake air in a high-speed, high-load region where the intake air ω increases. The intake passage is formed with a large passage diameter corresponding to high intake conditions, and the passage volume on the downstream side of this timing valve becomes large, so that the pumping loss reduction effect or delayed opening due to the inclusion of this timing valve is sufficient. This means that you will no longer be able to obtain it.

SUMMARY OF THE INVENTION In view of the above circumstances, it is an object of the present invention to provide an engine intake system that achieves both the intake control effect of a timing valve and the improvement of high-speed output.

(Means for Solving the Problems) In the intake system of the present invention, a timing valve is provided between the surge tank and the intake port in the main intake passage, and the timing valve is bypassed so that one end is connected to the surge tank and the other end is connected to the surge tank. The present invention is characterized in that an auxiliary intake passage connected to the intake port is provided, and a control valve is provided that opens the auxiliary intake passage at least at high speeds and high loads.

(Function) In the above-mentioned intake system, at low speeds and low loads, the control valve closes and the timing valve operates to supply intake air from the main intake passage, while at high speeds and high loads, the control valve opens and supplies air from the auxiliary intake passage. also supply intake air,
The main intake passage is set downstream of the timing valve for low speed use, and the downstream end of the auxiliary intake passage is connected to the intake port and set for high speed use without affecting the characteristics of the main intake passage. The operation is intended to provide an intake control effect at low speeds and an improvement in high-speed output.

(Example) Hereinafter, each embodiment of the present invention will be described along with the drawings.

Embodiment 1 This embodiment, whose overall configuration is shown in FIG. 1, is an example in which the late opening in a rotary piston engine is designed to obtain an inertial effect.

The engine 1 includes a rotor 4 housed in a casing made up of a rotor housing 2 and a side housing 3 so as to be capable of planetary rotation, and a working chamber 5 is formed around the outer periphery of the rotor 4 . The side housing 3 is provided with a main intake port 6 and an auxiliary intake port 7, each of which opens into the working chamber 5 for the intake stroke.

Intake passage 8 that supplies intake air to the working chamber 5 of the engine 1
is equipped with an air cleaner 9 and an intake surface sensor 10 on the upstream side, and a surge tank 12 is interposed on the downstream side of the throttle valve 11. A main intake passage 13 is connected from the surge tank 12 to the main intake port 6. A timing valve 15 is interposed in the main intake passage 13 that communicates the surge tank 12 and the main intake port 6. The rotation of the output shaft 16 of the engine 1 is transmitted to the timing valve 15 via the belt 17, and the timing valve 15 is driven to rotate in synchronization with the rotation of the engine 1 at a predetermined timing (second timing).
(see figure) to open and open the main intake passage 13.

Further, the main intake passage 13 has a passage length that provides a dynamic effect at low speeds, and the downstream portion of the timing valve 15 has a small passage volume for low speeds.

On the other hand, an auxiliary intake passage 14 is provided that bypasses the timing valve 15 of the main intake passage 13, and this auxiliary intake passage 14 is connected to the surge pump 12 at one end and to the auxiliary intake port 7 at the other end. A control valve 18 is interposed in the middle of the auxiliary intake passage 14 to open this passage at least in a high speed and high load range. The control valve 18 is opened and closed by a first actuator 19, and the first actuator 19 is closed when negative pressure is introduced by the negative pressure introduction passage 20. A three-way solenoid valve 21 and a check valve 22 for controlling the opening and closing operation of the control valve 18 are interposed. Further, the passage length of the auxiliary intake passage 14 is set for high-speed operation.

Further, a communication passage 23 is provided that communicates the main intake passage 13 and the auxiliary intake passage 14 upstream of the timing valve 15, and a communication valve 24 is interposed in the communication passage 23.

The communication valve 24 is opened and closed by a second actuator 25, and the second actuator 25 is connected to the negative pressure introduction passage 2.
The negative pressure introduction passage 26 includes a three-way solenoid valve 27 that controls the opening and closing operation of the communication valve 24 and a check valve 2.
8 is interposed.

Control signals from a control unit 29 (microcomputer) are outputted to both three-way solenoid valves 21 and 27 that control the operation of the control valve 18 and the communication valve 24 according to the operating state, and the opening and closing operations thereof are controlled. Ru. This control unit 29 includes an intake flea signal Qa from the intake air amount sensor 10 to detect the engine load.
, and a rotation sensor 3 for detecting the engine rotation speed.
An engine rotation signal Ne starting from 0 is input.

The opening and closing timings of the main intake port 6, the auxiliary intake port 7, and the timing valve 15 are set as shown in FIG. The auxiliary intake port 7 opens at approximately the same timing as the main intake port 6 and closes later. Furthermore, the timing valve 15 opens late in the middle of the intake stroke and closes together with the main intake port 6.

On the other hand, the operating range of the control valve 18 and the communication valve 24 is the third
As shown in the figure, engine speed Ne and load Qa/Ne
On the other hand, the control valve 18 has the engine speed set to the first set value N.
1 or more, the opening operation is performed in a high rotation, high load area of the area where the load is higher than the load along the running resistance line L. Roughly speaking, the communication valve 24 is operated to open in the high rotation and high load region of the region (3) in which the engine speed is higher than the second set value N2 in the above-mentioned region work.

To explain the operation of the intake system of this embodiment, in a low speed range, the auxiliary intake passage 14 is closed by the closing operation of the control valve 18, and the working chamber 5 receives intake air only from the main intake passage 13 through the main intake port 6. Supplied. In this case, the timing valve 15 is not yet open when the main intake port 6 opens, and the pressure change in the main intake port 6 is caused by the pressure change in the working chamber 5 until the main intake port 6 opens and the timing valve 15 changes. A large negative pressure is generated due to the expansion, and as soon as the timing valve 15 is heard, intake air starts flowing in at a large flow rate,
The inertial supercharging effect can be obtained during the period when the pressure increases and reaches the highest pressure near the closing of the main intake port 6, pushing the intake air into the working chamber 5 and increasing the filling efficiency of the intake air.

Next, when the engine speed and load increase and reach the above range, a control signal is output from the control unit 29 to the three-way solenoid valve 21 for the first actuator 19 to open the control valve 18. Intake air is also supplied to the working chamber 5 of the engine from the auxiliary intake port 7. In this case, a large amount of intake air is efficiently supplied by the auxiliary intake passage 14 set for high speed.

Furthermore, when the engine speed increases to reach region (3), a control signal is output from the control unit 29 to the three-way solenoid valve 27 for the second actuator 25, and the communication valve 24 of the communication passage 23 is opened. This communication path 2
By opening No. 3, the filling efficiency is further improved through the propagation of pressure waves. That is, when the main intake passage 13 is set to have a passage diameter etc. for low speeds to obtain a dynamic effect of intake air between it and the surge tank 12 as described above, when the main intake passage 13 is in a high speed state, the surge tank 12 The rotor 4 of the engine 1 rotates and closes the timing valve 15 before the reverse pressure wave from the engine arrives, and at that time, the communication valve 24 is open, so that this pressure wave is transferred to the communication path 23. The air then propagates to the auxiliary intake port 7 whose closing timing is late, and acts to force the intake air into the working chamber 5, thereby improving the filling efficiency of intake air. Furthermore, since the auxiliary intake port 7 closes later than the main intake port 6, high-pressure intake air is prevented from being trapped in the main intake port 6 downstream of the timing valve 15.

As described above, by using the timing valve 15 of the main intake port 6, the inertial supercharging effect and the high-speed characteristics of the auxiliary intake port 7 can be fully exhibited, and the filling efficiency can be favorably improved over a wide area.

Embodiment 2 This embodiment is shown in FIGS. 4 to 6, and is an example of obtaining the early closing pumping loss reduction effect in an in-line four-cylinder engine.

The engine 34 includes a cylinder 35 in which a main intake port 36 for low speed, an auxiliary intake port 37 for high speed, and an exhaust port 39 are opened, and the exhaust port 39 has an exhaust passage 4.
0 is connected.

The intake passage 38 that supplies intake air to the cylinder 35 of the engine 34 has an air cleaner 9 and an intake port sensor 10 on the upstream side, and a surge tank 4 on the downstream side of the throttle valve 11.
2 is interposed. From the surge tank 42 to each cylinder 3
A main intake passage 43 is connected to the main intake port 36 of No. 5. A timing valve 45 is interposed in a main intake passage 43 that communicates the surge tank 42 with the main intake port 36. The rotation of the output shaft 46 of the engine 1 is transmitted to the timing valve 45 via a belt 47, and the timing valve 45 is rotationally driven in synchronization with the rotation of the engine 34.
The main intake passage 43 of each cylinder 35 is opened at a predetermined time (see FIG. 5) by communicating the opening 45a.

Further, the main intake passage 43 has a dynamic effect of 1q at low speeds.
The downstream side portion of the timing valve 45 is set for low speed operation with a small passage volume.

On the other hand, an auxiliary intake passage 44 that bypasses the timing valve 45 of the main intake passage 43 is provided for each cylinder 35. One end of this auxiliary intake passage 44 is connected to the surge tank 42, and the other end is connected to the auxiliary intake passage 44 of each cylinder 35. It is connected to the intake port 37. Control valves 48 are interposed in the middle of the auxiliary intake passages 44 to open the passages at least in high speed and high load ranges. The control valve 48 is opened and closed by a first actuator 19 as in the previous example, and a three-way solenoid valve 21 for controlling the opening and closing operation of the control valve 48 is interposed in the negative pressure introduction passage 20 to the first actuator 19. Further, the passage length of the auxiliary intake passage 44 is set for high-speed operation. Intake port 3 of each cylinder 35
The main intake passage 43 and the auxiliary intake passage 44 on the downstream side near 6.37 are injected with fuel into both intake passages 43 and 44.
A nozzle injector 49 is provided.

Further, each cylinder 3 on the upstream side of the timing valve 45
A communication passage 53 is provided that communicates the main intake passage 43 and the auxiliary intake passage 44 of No. 5, and a communication valve 54 is interposed in the communication passage 53. The communication valve 54 is opened and closed by a second actuator 25 similar to the previous example, and a three-way solenoid valve 27 for controlling the opening and closing operation of the communication valve 54 is interposed in the negative pressure introduction passage 26 to the second actuator 25.

A control signal from the control unit 29 similar to the previous example is outputted to both the three-way solenoid valves 21 and 27 that control the operation of the control valve 48 and the communication valve 54 according to the operating state, and the opening and closing operations thereof are controlled. . The rest of the structure is the same as that of the previous example, and the same structures are given the same reference numerals.

The opening and closing timings of the main intake port 36, the auxiliary intake port 37, and the timing valve 45 are set as shown in FIG. Compared to the opening/closing timing of the main intake port 36, the opening/closing period of the auxiliary intake port 37 is set to be slightly longer for high speed operation, and the timing valve 45 opens substantially simultaneously with the main intake port 36 and closes earlier.

On the other hand, the operating range of the control valve 48 and the communication valve 54 is the sixth
As shown in the figure, engine speed Ne and load Qa/Ne
On the other hand, the control valve 48 opens in the high load range and in the high speed and high load range where the engine speed is above the first setting 1ifIN1 and the load is above the load along the running resistance line. be. Further, the communication control valve 48 is opened in the high rotation and high load region (2) in which the engine speed is higher than the second set value N2 even in the above region (2).

To explain the operation of this embodiment, in the low speed and low load range, the auxiliary intake passage 44 is closed by the closing operation of the control valve 48, and intake air is supplied to each cylinder 35 only from the main intake passage 43 through the main intake port 36. be done. In this case, intake air is supplied from the main intake port 36 only while the timing valve 45 is open, and the pumping loss can be reduced by substantially reducing the stroke volume.

Next, when the load or the engine speed increases to reach the region (3), the control valve 48 is opened, and intake air is also supplied to each cylinder 35 of the engine 34 from the auxiliary intake port 37. In this case, the auxiliary intake passage 44 set for high speed
This allows for efficient supply of multiple intake air.

Further, when the engine speed increases to reach the region (3), the communication valve 54 of the communication passage 53 is opened, and the filling efficiency is improved by the propagation of pressure waves. That is, as described above, the main intake passage 43 is closed at an early stage by the timing valve 45, and the positive pressure wave generated by damming up the intake air returns to the upstream side. This propagates to the auxiliary intake port 37 that is supplying the intake air and acts to push the intake air into the cylinder 35, thereby improving the intake air filling efficiency at high speeds.

As mentioned above, the timing valve 45 of the main intake port 36
By fully utilizing the early closing pumping loss reduction effect and the high-speed characteristics of the auxiliary intake port 37, it is possible to obtain a good improvement in filling efficiency over a wide area.

In the above embodiment, the main intake passage and the auxiliary intake passage are connected to the main intake port and the auxiliary intake port, respectively, which are formed separately. In that case as well, the volume of the main intake passage downstream of the timing valve can be set small to obtain the desired effect.

(Effects of the Invention) According to the present invention as described above, a timing valve is provided in the main intake passage, an auxiliary intake passage is provided that bypasses the timing valve and connects to the intake port, and furthermore, the auxiliary intake passage is connected to the intake port. By providing a control valve that opens at least at high speeds and high loads, intake air is supplied from the main intake passage by the operation of the timing valve at low speeds and low loads, and intake air is also supplied from the auxiliary intake passage at high speeds and high loads. The main intake passage can be set for low speeds by reducing the volume downstream of the timing valve, and the auxiliary intake passage can be connected at its downstream end to the intake port to influence the characteristics of the main intake passage. By setting the timing valve for high-speed operation instead of setting it for high-speed operation, it is possible to achieve both the intake control effect at low speed and the improvement of high-speed output by the operation of the timing valve.

[Brief explanation of the drawing]

Fig. 1 is a schematic configuration diagram of an engine equipped with an intake system according to the first embodiment of the present invention, Fig. 2 is a characteristic diagram showing the opening/closing timing of the intake port and timing valve in the first embodiment, and Fig. 3 is a A characteristic diagram showing the operating range of the control valve and the communication valve, FIG. 4 is a schematic configuration diagram of an engine equipped with an intake system according to the second embodiment of the present invention, and FIG. 5 is an intake port according to the second embodiment. FIG. 6 is a characteristic diagram showing the operating range of the control valve and the communication valve. 1.34...Engine, 5...Working chamber, 6.36...Main intake port, 7.37...
...Auxiliary intake port, 8.38...Intake passage, 12.42...Surge tank, 13.43.
...Main intake passage, 14.44...Auxiliary intake passage, 15.45...Timing valve, 1
8.48... Control valve, 29... Control unit.

Claims (1)

[Claims] (1) In an engine equipped with a timing valve in the intake passage that opens and closes in conjunction with engine rotation, the timing valve is provided in the main intake passage between the surge tank and the intake port, while the timing valve is bypassed. An intake system for an engine, comprising an auxiliary intake passage whose one end is connected to a surge tank and the other end to an intake port, and a control valve which opens the auxiliary intake passage at least at high speeds and high loads.