JPS63162931A - Intake controller for engine - Google Patents

Abstract

PURPOSE:To improve the negative pressure force in the intake inertia supercharge by installing a rotary timing valve into an intake passage and installing an auxiliary opening/closing valve onto the upstream side of the rotary timing valve. CONSTITUTION:A rotary timing valve 15 is installed into a supercharge intake passage 9 which bypasses a natural intake passage 2. The upstream side passage of the rotary timing valve 15 is divided into the branched passages 29A and 29B, and an auxiliary opening/closing valve 31 is installed into one branched passage 29A. Therefore, the dead volume between the rotary timing valve and an take port can be reduced,and the negative pressure force in the intake inertia supercharge can be increased.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an engine intake control device.

(Prior Art) Conventionally, as an engine intake control device, for example, a rotary timing valve is provided in the intake passage of the engine,
Many proposals have been made to improve the intake air filling efficiency by appropriately controlling the opening/closing timing and opening/closing period of the rotary timing valve in relation to the engine operating stroke.

By the way, the above-mentioned rotary timing valve used in such an engine intake control device is basically controlled to open and close in synchronization with the engine rotation, so naturally, when the engine rotation speed increases, The opening time of the low retiming valve in one stroke is also shortened accordingly. Therefore, there is a problem in that the intake air filling efficiency is lower in the high rotation range than in the low rotation range.

Therefore, the opening/closing timing and opening/closing period of the rotary timing valve itself are controlled variably (for example, by changing the phase) according to the engine operating range, thereby improving the intake air filling effect over a wide operating range. Of course, this is also possible, but if such a configuration is adopted, the structure of the intake control device will be considerably complicated and the cost will be considerably high.

For this purpose, conventionally, for example, as described in Japanese Patent Application Laid-Open No. 104115/1984, an auxiliary on-off valve (shutoff valve) is further provided downstream of the above-mentioned rotary timing valve, and this auxiliary on-off valve is used to control the rotary timing valve. An engine intake control device has been proposed which has a simple and low-cost structure and is designed to improve intake air filling efficiency over a wide range of operating ranges by substantially variably adjusting the opening/closing timing and opening/closing period.

(Problems to be Solved by the Invention) However, as in the prior art disclosed in the above-mentioned publication, an auxiliary opening/closing valve is provided downstream of the rotary timing valve to adjust the actual opening/closing timing of the rotary timing valve. In this case, the following problems arise.

(1) First, when the valve is closed, a dead volume is formed between the low retiming valve and the auxiliary opening/closing valve downstream thereof, and this dead volume causes an inertial supercharging effect to be performed, for example, by closing the intake air late. When applied to such an engine, the degree of negative pressure generated decreases accordingly. Furthermore, when partial supercharging is performed, supercharging air blows back into the naturally-aspirated main intake passage in the next stroke. Further, due to the intake air blowback due to the dead volume of the downstream sea of the rotary timing valve, carbon etc. in the intake air adheres to the auxiliary opening/closing valve, making the valve operation uncertain.

(2) Next, when the auxiliary on-off valve is in the closed state, atmospheric pressure acts on the upstream side of the engine during the intake stroke, and large intake negative pressure acts on the downstream side. As a result, a large pressure is repeatedly applied to the auxiliary on-off valve from the upstream side to the downstream direction, which may cause problems in terms of durability.

(Means for Solving the Problems) The present invention has been made for the purpose of solving the above-mentioned problems, and therefore an engine is provided with a low retiming valve that opens and closes the intake passage at a predetermined timing. An auxiliary opening/closing valve is provided upstream of the rotary timing valve to variably adjust the substantial opening/closing timing of the rotary timing valve.

(Function) According to the above means, since the auxiliary on-off valve is provided upstream of the rotary timing valve, the dead volume between the rotary timing valve and the intake boat can be reduced, so that the intake inertia supercharging is reduced. It is possible to improve the negative pressure during operation or the timing control performance of partial supercharging, and it is also possible to prevent carbon adhesion caused by intake air blowing back to the auxiliary on-off valve. Furthermore, unlike the case where negative intake pressure acts directly on the auxiliary on-off valve, the effect of negative intake pressure is blocked by the low timing valve, which has a strong structure, so the pressures generated before and after the auxiliary on-off valve are almost the same pressure. This reduces the pressure difference and improves durability.

(Embodiment) First, FIG. 1 shows a first embodiment in which the engine intake control device of the present invention is applied to a partially supercharged automobile engine.

First, in FIG. 1, the reference numeral l indicates the engine body, and the natural intake passage (main intake passage) 2 of the engine body l includes:
A carburetor 3, a throttle valve 4, and a surge tank 5 are arranged in series from the air cleaner AC side, and a naturally aspirated boat (
It is communicated with the engine combustion chamber 8 via the main intake boat 7.

Further, a supercharged intake passage 9 equipped with a supercharger lO and an intercooler 11 is bypassed from the downstream part of the carburetor brake 3 of the natural intake passage 2, and the introduction end of the supercharged intake air is connected to the supercharged intake passage 9. It is communicated with the engine combustion chamber 8 via a supercharged intake boat (sub-intake boat) 13 with an intake valve 12 interposed therebetween.

Downstream of the intercooler 11 in the supercharging intake passage 9, there is a sub-throttle valve 14 that operates in conjunction with the throttle valve 4 for performing partial supercharging at high loads, and a low retiming valve for adjusting the supercharging timing. 15 are provided respectively.

For example, if the engine I is an in-line two-cylinder type, the rotary retiming valve 15 is connected to a rotary shaft 1 that rotates in synchronization with the engine rotation, as shown in detail in FIG.
6, a solid cylindrical rotor (valve body) 17 supported by the rotating shaft 16, and a valve casing 18 into which the rotor 17 is loosely fitted.

Each end of the rotating shaft 16 is rotatably supported by the casing 18 via a bearing 19 (the bearing on the right side in FIG. 2 is not shown), and the inner end has the solid cylindrical shape The rotor 17 is integrated.

This rotor 17 has communication ports 20°+20 in the main body thereof, spaced apart from each other in the axial direction and at varying angles in the circumferential direction, in a number corresponding to the number of cylinders (two in the embodiment). On the other hand, on the upstream side of the casing 18 facing the cylindrical side wall of the rotor 17, there are two upstream passages 9a, 9 that serve as supercharging intake passages upstream of the rotor 17.
a is formed. This upstream passage 9a, 9
a is connected to each cylinder (each supercharging intake port) 13) of the engine main body l via the rotary timing valve 15, respectively.
They are connected to the rotor 17 and are formed at intervals in the axial direction of the rotor 17. The other end side of the communication port 20° 20 of the rotor 17 is also communicated with the downstream supercharging intake passages 9b, 9b of each cylinder located downstream thereof. Accordingly, when the communication port 20 matches a predetermined downstream passage 9b according to the rotation of the rotor 17, the supercharged intake boat of the cylinder corresponding to the corresponding downstream passage 9b is connected to the corresponding upstream side passage 9b. It is designed to be opened to passage 9a.

The upstream passage 9a section immediately upstream of the rotor 17 is
As shown in FIG. 3, the partition wall 30 defines two branch passages 29A and 29B in the rotational direction of the rotor 17 (indicated by arrow A in FIG. 3). Of the two branch passages 29A and 29B, a cutoff valve (corresponding to an auxiliary opening/closing valve in the claims) 31 is disposed in one branch passage 29A on the front side in the rotational direction of the rotor 26. has been done. This cutoff valve 31 has its operating central axis 31
It is a swinging type that opens and closes according to rotation around a,
In the embodiment, the valve is of a butterfly type and has a pair of valve plates 31b and 31c that extend in the radial direction from the operating center axis 31a at I80 degrees opposite sides. The shutoff valve 31
is adapted to be driven by, for example, a diaphragm device 32.

This diaphragm device 32 is provided with an exhaust pressure chamber 32a, and the engine body 1 is connected to this exhaust pressure chamber 32a via an exhaust pressure passage 33.
Exhaust pressure is introduced from an exhaust passage 26 connected to an exhaust port 25 of the exhaust port 25 . Then, when this exhaust pressure is large, the diaphragm 32b
2c, the rod 32d is pushed in the direction of arrow C in FIG.
The shutoff valve 31 is opened by rotating the operating center shaft 31a of the shutoff valve 31 in the counterclockwise direction in FIG. 3 (in the direction of arrow C in FIG. 3).

Here, the operating center axis 31a of the shutoff valve 31 is offset by Od from the center axis Y of the branch passage 29A in which it is provided, and in the embodiment, this offset direction is
The direction is such that it is on the near side in the rotational direction of the rotor 17. Further, when the shutoff valve 31 is changed from the closed position shown by the dashed-dotted line in FIG. 31c is displaced toward the upstream side of the branch passage 29A.

Next, the operation of the engine intake control device configured as above will be explained.

First, when the main throttle valve 4 is under low load with a predetermined opening degree or less, the supercharger 10 is not driven and the auxiliary throttle valve 14 is closed, so that intake air flows only from the natural intake port 7 into the engine combustion chamber. 8 for natural intake.

On the other hand, when the main throttle valve 4 is under high load with a predetermined opening degree or more, the auxiliary throttle valve 14 is opened. Partial supercharging is performed in which supercharging air is supplied from 13 to the engine combustion chamber 8.

During the above partial supercharging, when the engine speed is low, the exhaust pressure is small, so the shutoff valve 3I is closed, and therefore,
Substantially, the opening timing of the rotary timing valve 15 is delayed (see FIG. 4).

Furthermore, when the engine rotates at a high speed, the exhaust pressure increases, so the shutoff valve 3I opens, thereby opening the rotary timing valve 15 earlier (see FIG. 5). That is, when the cutoff valve 31 is open, the opening timing of the rotary timing valve 15, that is, the opening timing of the supercharging intake passage 9, is earlier by the amount indicated by angle β in FIG. 3, compared to when it is not open. and the valve opening period becomes longer. Therefore, even though the rotor 17 rotates quickly at high speeds, a sufficient amount of supercharging air is supplied to the engine combustion chamber 8.

Here, when the shutoff valve 31 opens, its operating center axis 31a is offset with respect to the center axis Y of the branch passage 29A, and the valve plate 31c on the opposite side to the offset direction is located upstream thereof. Since the cutoff valve 31 is displaced to the side, the cutoff valve 31 is prevented as much as possible from becoming a resistance to the supercharging air flowing through the branch passage 29A.

Further, the cutoff valve 31 that variably adjusts the substantial opening/closing timing of the low retiming valve 15 is provided upstream of the low retiming valve 15 in the supercharging intake passage.

Therefore, while the dead volume between the rotary timing valve 15 and the intake boat is reduced, the rotary timing valve 15 prevents intake air from flowing back to the cutoff valve 31. Therefore, carbon etc. do not adhere to the shutoff valve 31, and accurate operating conditions can be ensured.
Wear. Additionally, as a result, the pressure difference acting on the shutoff valve 31 can be reduced compared to when negative pressure acts directly on the shutoff valve 31 itself, leading to improved durability.
(See Figure 4).

Next, FIG. 6 shows a second embodiment in which the engine intake control device of the present invention is applied to a naturally aspirated automobile engine that utilizes the intake inertia effect.

In Fig. 6, first, the symbol I is the engine body;
An air cleaner A is installed in the main intake passage 50 of the engine body l.
Air flow meter 5 sequentially from the C side to the intake downstream direction
1. A throttle valve 52, a surge tank 53, and a shack valve 54 are arranged in series, and the intake inlet end thereof is communicated with the engine combustion chamber 8 via an intake port 7 with an intake valve 6 interposed therebetween. There is.

Further, reference numeral 56 denotes the surge tank 5 of the main intake passage 50.
This is a timing intake passage having a predetermined passage length for obtaining intake inertia, which is provided by bypassing the main intake passage 50 from part 3 to a position downstream of the shutter valve 54, and is provided downstream of the timing intake passage 56. A rotary timing valve 15 (see FIGS. 2 and 3) similar to that of the first embodiment is provided in the section. In the case of this rotary timing valve 15 as well, as in the case described above, a cutoff valve 31 that variably adjusts the opening and closing timing of the rotary timing valve 15 is installed upstream of the rotary timing valve 5. . In this embodiment, in order to improve responsiveness, the shutoff valve 31 is driven by an electromagnetic actuator 60 instead of the exhaust pressure diaphragm 32. The electromagnetic actuator 60 and the electromagnetic actuator 55 for operating the shatter valve 54 are both controlled by control signals from the engine control unit 70.

In the configuration of this embodiment, as shown in FIG. 7, in the low speed region, the shack valve 54 of the main intake passage is closed and the above-mentioned cutoff valve 31 is also closed, and the intake air is taken through the timing intake passage 56 having a long passage length. The intake connection due to the inertia increasing effect and the slow opening timing of the rotary timing valve 15 achieves high intake air filling efficiency, while in the medium speed region only the shutoff valve 31 is opened with the shatter valve 54 kept closed. In other words, the opening timing of the rotary timing valve 15 is made earlier to lengthen the actual valve opening period and improve the intake air filling efficiency. Then, when the speed reaches an even higher speed range, the shatter valve 54 itself is finally opened to enable the supply of sufficient intake air.

As described above, in this embodiment as well, the cutoff valve 31 that variably adjusts the substantial opening/closing timing of the rotary timing valve 15 is provided upstream of the timing intake passage of the rotary timing valve 15. ing.

Therefore, as in the case of the first embodiment, the dead volume between the low retiming valve 15 and the intake boat is reduced. Therefore, a decrease in the degree of negative pressure generation can be prevented, and since intake air blowback is prevented by the low retiming valve 15, carbon and the like will not adhere to the cutoff valve 31.

Furthermore, as a result, the pressure difference acting on the shutoff valve 31 can be reduced compared to the case where negative pressure acts directly on the shutoff valve 31 itself, leading to improved durability.

In addition, a cutoff valve 3 is installed in the supercharging intake passage or the natural intake passage.
1, it is also possible to adopt a passage configuration as shown in FIG. 8 as a third embodiment.

That is, since the rotary timing valve 15 rotates at a considerably high speed in the direction of the arrow shown in the figure, for example, it applies a stress vector b in a direction perpendicular to the intake air inflow pressure vector a as shown in FIG. It turns out. Therefore, in the case of a straight passage structure as illustrated in the first and second embodiments, the passage resistance against intake air inevitably increases. Therefore, in the configuration shown in FIG. 8, the first branch passage 29A is formed to correspond to the passage inclination angle of 0 when the low retiming valve 15 is opened. In this way, the phase of the inflow air pressure vector a at high speeds can be changed as shown by a', and the phase is not affected by the vector in the rotational direction of the rotor retiming valve 15. resistance decreases. As a result, it also contributes to improving the intake air filling effect.

Note that although the above description has been made in the case of a reciprocating engine, it goes without saying that the present invention can also be applied to a rotary engine.

(Effects of the Invention) As described above, the present invention provides an engine in which an intake passage is provided with a rotary timing valve that opens and closes the intake passage at a predetermined timing. This is characterized by the provision of an auxiliary opening/closing valve that variably adjusts the actual opening/closing timing of the valve.

Therefore, according to the present invention, since the auxiliary opening/closing valve is provided upstream of the low retiming valve, the dead volume between the low retiming valve and the intake boat can be reduced. It is possible to improve the negative pressure of the engine or to improve the timing control performance of partial supercharging, and it is also possible to prevent carbon adhesion caused by intake air blowing back to the auxiliary on-off valve. Furthermore, unlike the case where negative intake pressure acts directly on the auxiliary on-off valve, the effect of negative intake pressure is blocked by the low timing valve with a strong structure, so the pressure generated after the auxiliary on-off valve is engaged is almost the same pressure. This reduces the pressure difference and improves durability.

[Brief explanation of the drawing]

FIG. 1 is a control system diagram of an engine intake control device according to a first embodiment of the present invention, FIG. 2 is a sectional view showing the structure of a rotary timing valve section of the same embodiment device, and FIG.
Figures 4 and 5 are cross-sectional views showing the interlocking relationship between the cutoff valve of the rotary timing valve and its opening/closing drive device, and show the natural intake valve (main intake valve), cutoff valve, and rotary timing valve at low speed and high speed. FIG. 6 is a time chart showing the operational relationship between the three timing valves in correspondence with the pressure acting on the rotary timing valve; FIG. 6 is a control system diagram of the engine intake control device according to the second embodiment of the present invention; FIG. FIG. 8 is a valve timing diagram showing the control operation corresponding to the operating range of the device according to the embodiment, and FIG. The cross-sectional view shown in FIG. 9 is a vector diagram for explaining the function and effect. l...Engine body 2...Natural intake passage (main intake passage) 9...
Supercharging intake passage I5...Rotary timing valve 31...Shutoff valve 50...Main intake passage 54...Shutter valve Fig. 4 Fig. 5 Throttle opening fTVO1 Fig. 7 Fig. 8 Figure 9

Claims (1)

[Claims] 1. In an engine in which an intake passage is provided with a rotary timing valve that opens and closes the intake passage at a predetermined timing, an auxiliary opening/closing valve that variably adjusts the actual opening/closing timing of the rotary timing valve is provided upstream of the rotary timing valve. An engine intake control device characterized by being provided with.