JPS62118025A - Supercharger for engine - Google Patents

Abstract

PURPOSE:To improve the extent of supercharging efficiency at the time of engine's extensive driving, by installing an exciter, generating pressure vibration of the frequency conformed to engine speed, in a suction system, and varying exciting initial phase according to the engine speed. CONSTITUTION:A piston 23 being driven by a crankshaft 24 for an exciter 20 connected to another crankshaft 17 for engine use is installed in a suction passage 15 of an engine 2. This piston 23 reciprocates synchronously with rotation of the engine, making a suction pipe 15 generate a pressure wave, and performs its inertia supercharging. A rotational phase changer is installed between the crankshaft 24 of the exciter and a driving pulley 28, controlled by a control circuit 32 according to the revolving speed, and the excitation initial phase is varied according to the revolving speed, whereby although length of the suction pipe line 15 is constant, at the time of entering a suction valve 5, it is controlled so as to cause a high-tension point to get in without fail.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an engine supercharging device that supercharges intake air using a vibrator that generates pressure vibrations in an intake passage. .

(Prior Art) Conventionally, a supercharging device in which a vibrator is provided in the intake system to forcibly generate pressure vibration, and the intake air is supercharged by the pressure vibration, is disclosed in, for example, Japanese Utility Model Application Publication No. 58-14425. It is known from etc. The device disclosed in this publication uses a diaphragm that forms part of the wall of a resonance chamber formed in the intake passage, and an electromagnetic vibrator (actuator and coil) connected to this diaphragm. The diaphragm is forced to vibrate by passing an alternating current through the coil of the vibrator.

In such a device, pressure is applied so that positive pressure acts on the intake boat at the end of the intake stroke. & By matching the pressure vibration generated by the cylinder with the intake timing of each cylinder,
It can have a supercharging effect. In this case, in order to have a supercharging effect over a wide range of engine speeds, it is necessary to change at least the frequency of the pressure vibration caused by the vibrator depending on the engine speed. , the frequency of the alternating current in the coil 1 of the 8-stage generator is controlled in accordance with the detection signal of the engine speed.

However, even if the frequency of the pressure vibration by the vibrator is adjusted in this way, if the pressure vibration is only generated at a constant initial phase based on the engine crank angle, this pressure vibration will not propagate to the intake boat. The time required for the intake stroke to change is almost constant, whereas the intake stroke time varies depending on the engine speed, so the phase of the pressure vibration acting on the intake boat in the intake stroke path 1111 changes as the engine speed changes. There is a problem in that such a phase shift causes a rotation a range in which the supercharging effect is reduced.

(Objective of the Invention) In view of the above circumstances, the present invention effectively exerts a supercharging effect by applying pressure vibrations given by a vibrator to the intake boat of each cylinder in an appropriate phase over a wide range of engine speeds. The purpose of the present invention is to provide an engine supercharging device that can

(Structure of the Invention) The present invention provides an engine supercharging device equipped with an exciter that generates pressure vibrations at a frequency corresponding to the engine rotation speed in the intake system of the engine. A phase adjusting means is provided for changing the initial 111 phase according to the engine speed.

In other words, if the initial phase of the pressure wave generated by the exciter is constant, the phase of the pressure wave once it reaches the intake boat will shift as the engine speed changes. By adjusting the initial phase (initial phase of excitation) of the pressure wave so that the pressure wave is wetted, the phase of the pressure wave at the intake boat is maintained appropriately.

(Embodiment) FIGS. 1 and 2 show an embodiment of the present invention, and in these figures, 1 is an engine, 2 is each cylinder of the engine 1, and 3 is a cylinder formed above a piston 4 in the cylinder 2. This combustion chamber 3 has an intake boat 6 opened and closed by an intake valve 5 and an exhaust boat 8 opened and closed by an exhaust valve 7. Further, 10 is an intake passage that constitutes the intake system of the engine 1, and this intake passage 10
An air cleaner 11, an air flow meter 12, and a throttle valve 13 are disposed in the throttle valve 1.
A surge tank 14 is formed downstream of the pump 3, and a passage 15 formed for each cylinder communicates with the intake boat 6 from the surge tank 14. 16 is a fuel injection valve disposed in the passage 15.

The above-mentioned intake system is provided with a vibrator 20 that generates pressure vibrations with a frequency corresponding to the engine speed, and the vibrator 20 is connected to the surge tank 14, for example. In this embodiment, the excitation cylinder 22 is connected to the surge tank 14 through a communication hole 21.
and a vibration piston 23 provided within the vibration cylinder 22, and the vibration piston 23 reciprocates in accordance with the rotation of a crank-shaped input shaft 24, thereby causing The change in volume within the cylinder 22 causes pressure sensing. The input shaft 24 is operatively connected to the output shaft 17 of the engine 1 via a transmission mechanism 25 consisting of a timing belt 26, pulleys 27, 28, and the like.

In the transmission mechanism 25, the vibration piston 23
The cycle of pressure 1 movement caused by the reciprocating movement of engine 1
In order to correspond to the intake period of
A rotation speed ratio of 4 is set. For example, in the case of a 4-cylinder 4-stroke engine, two cylinders perform an intake stroke during one revolution of the output shaft 17, so the vibration piston 23 is moved back and forth between the output shaft 17 and the vibration piston 23 during this period. The rotational speed ratio of the input shaft 320 and the input shaft 24 is set to 1:2. The timing of the reciprocating movement of the excitation piston 23 is adjusted in advance so that positive pressure acts on the intake boat 6 for each cylinder 2 at the end of the intake stroke.

Further, a phase variable mechanism 3 is provided between the transmission mechanism 25 and the vibrator 20, which allows the initial phase of vibration of the vibrator 20 to be changed.
0 is provided, and the initial phase of excitation of the exciter 20 is adjusted according to the engine speed by this phase variable mechanism 30 and a control circuit 32 that receives the engine speed signal 31 and controls the phase variable mechanism 30. A phase adjustment means is configured. The phase variable mechanism 30 includes a pair of vertical splines 34 and 35 respectively provided on the driven shaft 33 connected to the driven pulley 28 of the transmission [925] and the input shaft 24 of the vibrator 20. Helical spline 34.35
The input shaft 24 of the vibrator 20 is displaced relative to the driven shaft 33 in the rotational direction by the axial movement of the adjustment member 36, thereby causing a change in the operation of the engine 1. The timing of the reciprocating operation of the vibration piston 23 is changed, and the initial phase of vibration can be changed.

Further, the control circuit 32 controls the phase variable mechanism 30 so as to change the initial phase of excitation to the advance side at a predetermined ratio as the engine speed increases, as shown by the solid line in FIG. There is.

According to the supercharging device configured in this way, pressure waves generated by the operation of the vibrator 20 are transmitted from the surge tank 14 to the passage 1.
5 to each cylinder 2 and acts on the intake boat 6 at a predetermined timing, the intake pressure is increased at the end of the intake stroke, the intake air is supercharged, and the charging efficiency is increased.

In this case, by operating the vibration exciter 20 in conjunction with the rotation of the engine 1, the frequency of the pressure wave is adjusted in a self-VJ manner according to the engine rotation speed, and the period of the pressure wave is adjusted to the suction period of the engine. matches. Moreover, in particular, since the phase variable mechanism 30 and the control circuit 32 change the initial phase of vibration of the vibrator 20 according to the engine speed,
Compared to the case where the initial phase of excitation is constant (double-dashed line B in FIG. 3), the supercharging efficiency is further improved over a wide rotational speed range. Such an action will be specifically explained with reference to FIG. 4.

Figure 4 shows the vibration exciter 20 for a 4-cylinder 4-stroke engine.
The horizontal axis shows the pressure fluctuation at the intake boat position due to the pressure wave propagated from the crank angle, and 1
0 represents the intake valve opening timing, BDC represents the piston bottom dead center, and IC represents the intake valve closing timing. As shown by the solid line C in this figure, the supercharging effect is maximized when the pressure wave acting on the intake boat 6 reaches its maximum before σ of the intake valve opening timing IC. However, if the initial phase of excitation is constant as shown by the two-dot chain line B in FIG.
Since the time required for the pressure wave to propagate at high speed from the air to the intake boat 6 is constant, the crank angle change during that time varies depending on the engine rotation speed, and the phase of the pressure wave at the intake boat position changes depending on the rotation speed. When the rotation speed becomes low, the rotation speed shifts to the leading side as shown by the two-dot chain line in FIG. When the phase shifts in this way, the supercharging effect decreases.

In contrast, in the device of the present invention, the initial phase of excitation is changed at a predetermined ratio according to the engine speed, so the phase shift at the intake boat position as described above is canceled out, and the fourth
The pressure wave acts on the intake boat 6 with an appropriate phase as shown by the solid line C in the figure.

Furthermore, if a positive displacement vibrator 20 that generates pressure vibrations due to a change in volume accompanying the operation of the vibration piston 23 is used as in this embodiment, the amplitude of the pressure vibrations can be increased compared to the conventional device described above. This also increases the supercharging effect. In other words, the above-mentioned conventional device only transmits the vibration of the diaphragm to the air in the resonance chamber, without paying attention to volume changes, and mechanically, it generates considerably high frequencies at high engine speeds. With a structure in which the diaphragm is driven by alternating current, it is difficult to generate large pressure fluctuations. On the other hand, in the case of the volume type addition 1i i? When S20 is used, the volume change due to the reciprocating movement of the vibration piston 23 causes the vibration cylinder 2 to
Therefore, the amplitude of the pressure oscillation of the intake air can be greatly increased, and the supercharging effect can be enhanced.

Note that the specific structure of the vibrator 20 and the driving means for the vibrator 20 are not limited to the above embodiments, and for example, a vibration generating member such as a gay 17 flam may be actuated by an electric driving means. In this case, it is sufficient to simultaneously control the pressure vibration frequency and the phase according to the engine speed using an electric signal.

(Effects of the Invention) As described above, the present invention uses a vibrator to generate pressure vibrations in the intake passage according to the engine rotation speed, and
Because the initial stage of vibration (ff phase) is avoided to change according to the engine speed, the phase of the pressure wave propagated through the vibrator at the intake boat position is prevented from shifting depending on the engine speed, and the engine speed is wide. It is possible to enhance the supercharging effect by applying pressure waves with appropriate phase to the intake boat over several regions.

[Brief explanation of drawings]

FIG. 1 is a schematic side view of a device according to an embodiment of the present invention, FIG. 2 is a schematic plan view of the same device,
FIG. 3 is an explanatory diagram showing the relationship between the engine rotational speed and the excitation phase, and FIG. 4 is an explanatory diagram showing the pressure fluctuation at the intake boat position. DESCRIPTION OF SYMBOLS 1... Engine, 10... Intake passage, 20... Adder Fit device, 30... Phase variable mechanism, 32... Control circuit. FT Permit Applicant Mazda Co., Ltd. Agent
Person Patent Attorney Etsushi Kotani Patent Attorney Chief 1) Masamukai Patent Attorney Itaya
Yasuo Figure 1

Claims (1)

[Claims] 1. In an engine supercharging device equipped with a vibrator in the engine intake system that generates pressure vibrations with a frequency corresponding to the engine speed, the initial phase of the vibration of the vibrator is adjusted according to the engine speed. A supercharging device for an engine, characterized in that it is provided with a phase adjusting means for changing the phase.