JPH0324832Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Technical Field) This invention relates to a resonance supercharging control device for a diesel engine.

(Background Art) Some diesel engines employ resonance supercharging to increase the intake air filling efficiency of each cylinder.

Resonant supercharging is a method that matches the frequency of the air column vibration in a resonance pipe formed in a part of the intake manifold with the frequency of the intake pulsation that occurs when the intake valve opens and closes, and uses this resonance to push a large amount of intake air into the cylinder. be.

Conventionally, there is a resonance supercharging device constructed as shown in FIG. 1, for example (Japanese Utility Model Publication No. 57-92021).

Resonance pipes 9 and 10 are connected to cylinders #1 to #3 and #4 to #6, whose intake valve opening timings do not overlap with each other, via confluence portions 7 and 8, respectively.

Then, a passage 11 is formed that communicates the merging parts 7 and 8, and this passage 11 is closed in a high engine load region.
A valve 12 that opens in a low load range is installed.

Note that 13 indicates a load lever of an injection pump 14, and the load lever 13 opens and closes the valve 12 via a wire 15 in accordance with the opening degree of the accelerator.

Therefore, in the engine high load range, valve 12
is fully closed and blocks the passage 11 of the merging portions 7 and 8, so that resonance supercharging is performed centering on the region where the air column frequency of each resonance tube 9 and 10 and the frequency of the intake pulsation match.

In other words, a large amount of fuel is injected in a high engine load range, but resonance supercharging ensures an amount of intake air commensurate with the increase in fuel.

On the other hand, in a low engine load range, the valve 12 opens the passage 11 of the merging sections 7 and 8, and the intake valve opening timings of cylinder groups #1 to #3 and #4 overlap.
The intake pulsations of ~#6 interfere with each other, and as a result, a resonance phenomenon cannot be obtained, and resonance supercharging is stopped.

In other words, resonance supercharging is stopped in a low engine speed range where the amount of fuel injection is small, thereby avoiding an increase in pumping loss due to excessive intake.

In this case, resonance supercharging cannot achieve good supercharging except in an extremely limited engine rotation range where the air column frequency of the resonance pipes 9 and 10 and the frequency of the intake pulsation match. Furthermore, a structure as shown in FIG. 2 has been proposed which aims to expand the engine rotation range in which resonance supercharging can be performed satisfactorily (Japanese Unexamined Patent Publication No. 115818/1983).

In this case, resonance pipes 9 and 10 connected to cylinders #1 to #3 and #4 to #6, whose intake valve opening timings do not overlap, through merging portions 7 and 8, respectively, merge on the upstream side.

In addition, resonance pipes 9 and 10 are cylinders #1 to #3 and #4 to
The frequency of the air column reaching the upstream merging portion 16 from #6 via the downstream merging portions 7 and 8 is the frequency of the intake pulsation in the low engine speed range, and the frequency of the air column from cylinders #1 to #3 and #4. The frequency of the air column extending from #6 to the downstream merging portions 7 and 8 is formed so as to match the frequency of the intake pulsation in the high rotation range.

A valve 12a is installed in a passage 11 that communicates the downstream merging parts 7 and 8, which closes in a low engine speed range and opens in a high engine speed range.

According to this, in the low engine speed range where the valve 12a is closed, the valve 12a is closed in the air column portions of the resonance pipes 7 and 8 from the cylinders #1 to #3 and #4 to #6 to the upstream confluence section 16. When you reach the high rotation range where it opens,
The effect of supercharging is achieved by resonance in the air column portions of the resonance pipes 9 and 10 extending from the cylinders #1 to #3 and #4 to #6 to the merging portions 7 and 8 on the downstream side.

By the way, FIG. 3 is a comparison diagram of equal fuel consumption curves based on experimental data for supercharging using only a turbo supercharger and when resonant supercharging is added to supercharging of the turbo supercharger.

In the figure, the dotted line A shows the equal fuel consumption curve when supercharging is performed only with the turbo supercharger, and the solid line B shows the equal fuel efficiency curve when resonance supercharging is added to the supercharging of the turbo supercharger.

As is clear from this figure, equal fuel consumption curves A and B
In the upper operating region, adding resonance supercharging to turbo supercharging has a better fuel efficiency, while in the lower operating region, conversely, turbo supercharging Supercharging using only fuel has a better fuel efficiency.

However, even in the operating range below curve C, in the low-speed, high-load range, the fuel efficiency rate is lower with turbocharging alone.

Therefore, for example, in order to maintain a good fuel efficiency over the entire operating range, opening and closing of the passage 11 may be controlled based on the engine load and boost pressure.

For this purpose, a valve linked to the engine load detection means and a valve linked to the boost pressure detection means must be interposed in series in the passage 11. In this case, the two valves are connected in series in the narrow passage 11. It is technically difficult to intervene.

(Purpose of the invention) This invention was developed by focusing on the above-mentioned problem. One valve is linked to two or more operating state detection means to open and close a passage that communicates between the joining parts of resonance tubes. The object of the present invention is to provide a resonance supercharging device for a diesel engine that can accurately control resonance supercharging.

(Structure and operation of the invention) Therefore, in a diesel engine in which resonance pipes are connected to a plurality of cylinders whose intake valve opening timings do not overlap each other through a joining part, this invention communicates the joining parts of the resonance pipes with each other. A valve is provided that forms a passage and opens and closes the passage in conjunction with multiple systems of operating state detection means, and a return spring that biases the valve rotating shaft in the valve opening direction is provided and is freely rotatably fitted to the rotating shaft. A plurality of levers are provided, and the free ends of the levers are individually linked to the operating means of the plurality of systems, and the lever rotation angle between these levers and the rotation shaft is a predetermined value or more, and only in the valve closing direction. Engaging locking means are provided.

That is, when at least one of the plurality of levers individually linked to the operation detection means of the plurality of systems is rotated to the valve fully closed angle position, the valve is fully closed;
At this time, the other levers rotate idly relative to the valve rotation axis. Therefore, it is possible to control resonance supercharging using only one valve in conjunction with multiple systems of operating state detection means.

(Example) This invention will be explained below according to the example shown in FIGS. 4 and 5.

Note that the same parts as in FIGS. 1 and 2 are designated by the same reference numerals.

Reference numerals 9 and 10 indicate resonance pipes, and the resonance pipes 9 and 10 connect cylinders #1 to #3 and #4 to cylinders whose intake valve opening timings do not overlap through confluence portions 7 and 8, respectively.
Connect to #6.

Note that the resonance pipes 9 and 10 merge on the upstream side, and a turbo supercharger 17 is installed upstream of the merged portion 16.

The turbo supercharger 17 supercharges the cylinders #1 to #3 and #4 to #6 from the resonance pipes 9 and 10 via the merging section 16 in accordance with the engine speed.

Reference numeral 11 denotes the downstream confluence portions 7 and 8 of the resonance tubes 9 and 10.
A valve 12b is connected to this passage 11.
is interposed.

The valve 12b has an arm 19 formed integrally with the rotary shaft 18 outside the passage 11, and is biased via the arm 19 by a return spring 20 to the valve fully closed position. Note that the rotation of the valve 12b is restricted to a rotation angle range from fully open to fully closed due to the relationship with the tension of the return spring 20.

On the axis of rotation 18 of the valve 12b, in this case two independent levers 21, 22 are attached to the cylindrical base 21.
A, 22A are fitted so that they can rotate freely in the circumferential direction.

Cylindrical bases 21A, 22A of levers 21, 22
Locking claws 21B, 22B are formed on the end faces of the rotating shaft 18, and locking protrusions 21C, 22C are formed on the outer periphery of the rotating shaft 18, corresponding to the locking claws 21B, 22B, respectively.

Then, when the levers 21 and 22 are rotated in the valve closing direction, the locking claws 21B and 22B engage the locking protrusion 2.
From the time when 1C and 22C are hit, the rotating shaft 18 is rotated against the tension of the return spring 20.

A bushing rod 23A of a diaphragm device 23 (described later) is attached to the free end of one lever 21, and a linkage 23A linked to the load lever 13 of the injection pump 14 is attached to the free end of the other lever 22.
4 are each connected with a pin so that they can rotate freely.

The diaphragm device 23 guides the boost pressure downstream of the turbocharger 17 from the confluence section 8, and when the boost pressure exceeds a set value, the rod 23A extends and rotates the lever 21 to the valve fully closed position.

On the other hand, the linkage 24 rotates the lever 22 in the valve closing direction according to the opening degree of the load lever 13, and fully closes the valve 12b when the engine load exceeds a set value.

In this case, when the valve is fully closed, further rotation of the rotating shaft 18 is restricted as described above, but for this reason, when the engine load exceeds the set value in the linkage 24, the opening degree of the load lever 13 will be adjusted. A spring 24A that expands accordingly, that is, absorbs the opening degree of the load lever 13, is interposed.

The setting value on the diaphragm device 26 side that determines the closing timing of the valve 12b is the equal boost pressure value shown by curve C in FIG. 3, and the setting value on the linkage 27 side is the same as the curve C in FIG. 3. In a lower operating range, the upper limit load value D is set such that the fuel efficiency becomes worse when supercharging is performed only by the turbo supercharger 17. In this case, in relation to the set values, the locking claws 21B, 22B and the locking protrusion 21 are in the initial position of the levers 21, 22.
A predetermined gap m is provided between C and 22C.

Therefore, the levers 21 and 22 each rotate in the valve closing direction with the stroke of the diaphragm device 23 and the linkage 24, and the locking claws 21B, 22B
The rotating shaft 18 is rotated against the return spring 20 from the time when the locking protrusions 21C and 22C come into contact with each other.

Now, when the engine load exceeds the set value, the valve 18 is fully closed as the lever 22 is rotated. Therefore, the passages 11 of the merging sections 7 and 8 are blocked, and the intake pulsations of cylinder groups #1 to #3 and #4 to #6, whose intake valve opening timings overlap, do not interfere with each other. , resonance supercharging is performed in addition to turbo supercharging based on the resonance caused by the resonance tubes 9 and 10. In other words, resonance supercharging is effective in the operating region above the upper limit load value D in FIG.

On the other hand, when the boost pressure exceeds the set value even in the operating range below the upper limit load value D, the valve 18 is fully closed as the lever 21 rotates. That is, resonance supercharging is performed in addition to turbo supercharging even in the operating region below the upper limit load value D in FIG. 3 and above curve C (equal boost curve).

On the other hand, when both the boost pressure and the engine load are below the set values, the rotation angle of the levers 21 and 22 does not fully close the valve 18, and therefore the passage 11
As a result of the interference between the intake pulsations of the merging portions 7 and 8 via the resonant supercharging, resonance supercharging is stopped and only the turbo supercharger 17 is supercharged.

Therefore, in this embodiment, a good intake air filling efficiency is ensured in the entire operating range from a low engine speed and low load range to a high engine speed and high load range, and a good fuel efficiency can be maintained.

Note that among the levers 21 and 22, one lever 2
When lever 1 or 22 rotates shaft 18, the other lever 22 or 21 idles at that position relative to shaft 18, so the operations of diaphragm device 23 and linkage 24 do not interfere with each other.

By the way, the valve 12b includes two or more operating state detection means, in this case a diaphragm device 23, and levers 21 and 22 that are respectively linked to a linkage 24 connected to the load lever 13 of the injection pump 14. When at least one of the valves 22 rotates in the valve closing direction, it is fully closed, so that only one valve 21b can accurately control resonance supercharging based on the boost pressure and engine load, and as a result, the operating state can be detected. Compared to the case where valves are provided individually for each means, structural simplification, weight reduction, and ease of valve installation can be achieved.

(Effects of the invention) In summary, according to this invention, in a diesel engine in which resonance pipes are connected to a plurality of cylinders through merging parts, where the opening timings of the intake valves do not overlap with each other, the merging parts of the resonance pipes are communicated with each other. A valve is provided that forms a passage and opens and closes the passage in conjunction with multiple systems of operating state detection means, and a return spring that biases the valve rotating shaft in the valve opening direction is provided and is freely rotatably fitted to the rotating shaft. A plurality of levers are provided, and the free ends of the levers are individually linked to the operating means of the plurality of systems, and the lever rotation angle between these levers and the rotation shaft is a predetermined value or more, and only in the valve closing direction. Since the engaging locking means is provided, the resonant supercharging can be controlled using only one valve in conjunction with multiple systems of operating state detection means.

[Brief explanation of the drawing]

1 and 2 are schematic configuration diagrams of different conventional devices, FIG. 3 is a map of equal fuel efficiency, FIG. 4 is a schematic configuration diagram showing an embodiment of this invention, and FIG. 5 is a perspective view of the main parts thereof. #1 to #6... Cylinder, 7, 8... Downstream merging section, 9, 10... Resonance tube, 11... Passage, 12b
... Valve, 18 ... Rotating shaft, 20 ... Return spring, 21, 22 ... Lever, 21B, 2
2B...Latching claw, 21C, 22C...Locking protrusion,
23...Diaphragm device, 24...Linkage.

Claims (1)

[Scope of utility model registration request] In a diesel engine in which a resonance pipe is connected to a plurality of cylinders whose intake valve opening timings do not overlap each other through a merging part, a passage is formed that communicates the merging parts of the resonance pipes with each other, and the operating state of multiple systems is detected. A valve is provided which opens and closes the passage in conjunction with the means, a return spring is provided which biases the valve rotating shaft in the valve opening direction, and a plurality of levers are rotatably fitted to the rotating shaft, and the free end of the lever is A locking means is provided that is individually linked to the plurality of operating means and engaged only in the valve closing direction in a region where the lever rotation angle is greater than a predetermined value between the lever and the rotating shaft. Resonant supercharging control device for diesel engines.