JPS6113708Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an intake system that utilizes resonance supercharging for a multi-cylinder engine.

Some internal combustion engines employ an intake air supply system called resonance supercharging (or inertia supercharging).

In this case, a negative pressure wave generated near the intake port at the start of intake propagates upstream toward the intake pipe, becoming a positive pressure wave and returning toward the intake port, causing intake pressure oscillations. I'm taking advantage of that.

In other words, by matching (resonating) the period of intake pressure vibration with the period of the intake valve opening/closing cycle so that the positive pressure wave is transmitted to the intake valve just before the intake valve closes, a positive pressure wave is generated. The air is forced into the combustion chamber by inertia, and the intake air filling efficiency can be improved by supercharging by inertia.

By the way, in a multi-cylinder engine, the intake stroke from each cylinder is continuously received at the confluence point of the intake passages connecting the cylinders that have intake interference with each other (cylinders whose intake valve opening timings overlap with each other). Maintained at constant negative pressure.

Therefore, when the intake negative pressure waves generated from each cylinder reach the merging point, they are buffered by the constant negative pressure at the merging point and are turned into positive pressure waves and returned toward the intake port. The vibration propagates back and forth between the combustion chamber and the merging point, and the resonant frequency of the intake pressure vibration depends on the size and shape of the intake passage between the combustion chamber and the merging point (hereinafter referred to as the resonant intake passage). It is determined.

However, in conventional engines that employ such resonant supercharging, the shape of the resonant intake passage is constant, so the intake valve opening/closing frequency and the resonant frequency of the intake passage can only resonate in a specific engine operating range. The operating range in which good resonance supercharging can be achieved is limited.

The present invention was devised in view of the above-mentioned difficulties in the conventional art. The resonator chamber is configured to be connected and shut off by switching control of the switching valve according to the engine operating status, and the structure is compact, ensuring good resonant supercharging performance in all engine operating ranges. The present invention provides a supercharging type intake device.

Hereinafter, the present invention will be described in detail based on illustrated embodiments.

In FIG. 1 showing one embodiment, a six-cylinder engine 1
The ignition order for cylinders 1 to 6 at every 120° crank angle is 1 → 4 → 2 → 6 → 3 →
5. Therefore, cylinders 〓1, 〓2 and 〓3
(hereinafter referred to as the first cylinder group A) and cylinders 4, 5, and 6 (hereinafter referred to as the second cylinder group B) are cylinders in each cylinder group whose intake valve opening timings substantially overlap. However, both cylinder groups have corresponding cylinders whose intake valve opening timings overlap with each other.

Intake manifolds 2A and 2B are connected to both cylinder groups A and B of such an engine, respectively, and intake pipes 3A and 2B are connected to each intake manifold 2A and 2B, respectively, and further, an intake pipe 3A is connected to a gathering part of each intake manifold 2A and 2B.
The upstream end of 3B is connected to the inside of the surge tank 4. An air cleaner 6 is connected to the inlet of the surge tank 4 via an intake pipe 5.

Here, in the present invention, both the intake manifolds 2
A and 2B are connected via a volume chamber 7. The volume chamber 7 is formed into a spherical (or cylindrical) shape, and has point-symmetric partition walls 8 and 9 that protrude toward the center of the volume chamber 7 from the openings of the intake manifolds 2A and 2B, respectively.
and configure it. The volume chamber 7 is provided with an initial changeover valve 10 which is pivotally supported at the center thereof, and two chambers 11 and 12 are formed by sliding both ends of the changeover valve 10 into sliding contact with the spherical inner wall surface of the volume chamber 7, respectively. is defined. Then, the actuator 14, which is controlled to expand and contract in response to a signal from the speed sensor 13 that detects the engine rotational speed, is connected to the support shaft 10 of the switching valve 10 via the lever 15.
a, and the rotation of the switching valve 10 is controlled as follows. That is, in a low/medium speed range where the engine speed is below a predetermined value No., the switching valve 10 is set to the switching position (shown by a solid line) in which it contacts the surfaces of the partition walls 8, 9, and the two chambers 11, 12 are closed, respectively. , cylinder groups A, B
It communicates with the intake manifolds 2A and 2B.

In addition, in a high-speed range where the engine rotational speed exceeds a predetermined value No., the switching valve 10 is set to the switching position (shown by chain lines) where it contacts the tips of the partition walls 8 and 9, and the two chambers 1
1 and 12 and the intake manifolds 2A and 2B are switched so that they are shut off. Here, speed sensor 1
3. The actuator 14 and the lever 15 switch the switching valve 10 between the two chambers 1 and 1 according to the detection of the engine operating state.
1 and 12 and intake manifolds 2A and 2B as corresponding resonant intake passages are configured to switch to a position where they are communicated or disconnected.

Next, the action will be explained. The resonant intake passage volume in each cylinder group A, B is the intake manifold 2A or 2B and the intake pipe 3A or 3B in the low/medium speed range of the engine.
In the high speed range, the volume of the intake manifold 2A or 2B and the intake pipe 3 is determined by subtracting the volume of the chamber 11 or 12.
It is determined by the total volume of A or 3B.

In this way, as the engine speed increases, the volume of the resonant intake passage can be reduced and the resonant frequency can be increased. As a result, the intake valve opening/closing frequency and the resonant frequency are the best in the low/medium speed range and the high speed range, respectively. It is possible to have a resonance point that matches the Therefore, the filling efficiency of intake air with respect to the engine rotational speed N has maximum points X and Y corresponding to the resonance points in the low, medium and high speed ranges as shown in FIG. Compared to the case where there is only one maximum point in , better intake air filling efficiency characteristics can be obtained over the entire speed range of the engine.

FIG. 3 shows a modification of the volume chamber, and by controlling the switching valve 10 installed in the cylindrical volume chamber 7 to the position shown by the solid line and the position shown by the chain line, the volume can be variably controlled according to the speed range. .

As explained below, according to the present invention, a portion of a pair of resonant intake passages is defined by a switching valve.
With a configuration in which two volume chambers are controlled to communicate and shut off depending on the engine operating status, good resonant supercharging can be performed over the entire engine operating range, improving intake air filling efficiency characteristics and significantly increasing engine performance. It is particularly effective in increasing output and improving exhaust emissions.

In addition, only one volume chamber and one switching valve are required, resulting in a compact structure.

[Brief explanation of the drawing]

Fig. 1 is an overall configuration diagram showing a first embodiment of the present invention, Fig. 2 is a graph showing intake air filling efficiency characteristics in the same embodiment, and Fig. 3 is a cross section of main parts showing a second embodiment of the present invention. It is a diagram. 1... 6-cylinder engine, 2A, 2B... Intake manifold, 3A, 3B... Intake pipe, 7... Volume chamber,
8, 9... Bulkhead, 10... Switching valve, 11, 12...
...chamber, 13...speed sensor, 14...actuator, 15...lever.

Claims (1)

[Scope of utility model registration request] In a multi-cylinder engine in which resonant supercharging passages are connected separately to cylinders whose intake valve opening timings overlap with each other, a pair of resonant supercharging passages is connected midway through two openings of a volume chamber each formed in a spherical or cylindrical shape. In addition to connecting, a switching valve is provided whose central portion is pivotally supported to freely slide and rotate along the wall of the volumetric chamber to divide the volumetric chamber into two chambers, and the switching valve is connected to A switching control switch is provided for switching the switching valve between a position where the two chambers communicate with the two corresponding resonance intake passages and a position where communication between the two chambers and the two resonance intake passages is cut off. A resonant supercharging intake system for multi-cylinder engines featuring: