JPS63111232A - Inertia supercharging device for internal combustion engine - Google Patents

Abstract

PURPOSE:To increase the inertia effect of intake air and to improve the volume efficiency of intake air, by a method wherein partition walls by which to partition the interior of a crank case into plural compartments are situated, and after, out of the compartments, the compartments the piston cycles of which are identical to each other are joined together, the joining point is connected to a suction passage through a pressure wave fetching pipe. CONSTITUTION:Partitions 12 are situated in a crank case 11 of a multicylinder diesel engine 1 so that adjoining cylinders are partitioned from each other thereby, and the interior of the crank case 11 is partitioned into plural compartments 131-136. The compartments 131-136 are communicated to their mating suction branch pipes 91-96 of a cylinder through a pressure wave fetching pipe 14 for amplification and a pressure wave fetching pipe 15 for damping. A pressure wave in an iso-phase or a reversed phase, generated by movement of a piston 10, can be introduced in the branch pipes 91-96. A switching valve 17 is situated to the branch part of each of the fetching pipes 14 and 15, and switching control is made so that the pressure wave fetching pipe 14 for amplification and the pressure wave fetching pipe 15 are selectively energized during high load running and during low load running, respectively.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to an inertial supercharging device for an internal combustion engine, and more specifically, the present invention relates to an inertial supercharging device for an internal combustion engine, and more specifically, it changes the volumetric efficiency of intake air according to the load to increase output and reduce pumping loss. The present invention relates to an inertial supercharging device for an internal combustion engine.

(Prior Art) In an internal combustion engine, intake air flows as intake inertia waves, which are pressure vibrations, in intake passages and passages by opening and closing an intake valve. This intake inertial wave is used to increase the volumetric efficiency of intake air,
An inertial supercharging device improves output.

The negative pressure generated in the intake port due to the suction action of the piston during the intake stroke is transmitted through the intake passage as a negative pressure wave.
It is reflected at the open end of the intake passage, becomes a positive pressure wave, and returns toward the intake port. Pressure oscillations occur due to the combination of these positive and negative pressure waves.

The influence of the pressure vibration generated in the intake passage during the intake stroke on the intake stroke includes an inertial effect and a pulsation effect. The inertial effect is ν1 when pressure vibration affects the same intake stroke.

Furthermore, the pulsation effect refers to a case where pressure vibrations occurring in a certain intake stroke give a 3'II effect to the intake stroke of the next cycle. In this application, pressure vibration waves in the intake passage including inertia effects and pulsation effects are referred to as intake inertia waves.

The natural frequency of the intake inertial wave is determined by the length and cross-sectional area of the intake passage. Therefore, we designed the length and cross-sectional area of the intake passage so that the natural frequency of the intake inertial wave matches the opening and closing timing of the intake valve, and the intake inertial wave becomes positive at the intake port just before the intake valve closes. so that it becomes a pressure,
An inertial supercharging device improves the volumetric efficiency of intake air.

(Problem to be solved by the invention) In an internal combustion engine, it is desirable to change the volumetric efficiency of intake air according to the level of load as follows. , it is desirable to increase the output.

On the other hand, if the volumetric efficiency is high at low loads, the load during the compression stroke will be large, resulting in pumping loss. Therefore,
At low loads, it is desirable to reduce the volumetric efficiency of intake air.

However, with conventional inertial supercharging devices, at high loads,
It was not possible to improve the volumetric efficiency beyond the normal intake inertia effect determined by the specifications of the intake passage. On the other hand, when the load is low, inertia supercharging is performed, resulting in a high volumetric efficiency and a disadvantage that pumping loss occurs.

An object of the present invention is to provide an inertial supercharging device for an internal combustion engine that can increase the volumetric efficiency of normal intake air to increase output at high loads, and conversely reduce the volumetric efficiency and reduce pumping loss at low loads. It's about doing.

(Means for solving problems) The present invention is characterized by the following configurations.

A compartment in which the interior of the crankcase is partitioned by a partition wall between the same cylinders of the piston cycle.

An amplification pressure wave extraction pipe that is provided to communicate a compartment and an intake passage, guides a pressure wave in the same phase as an intake inertial wave to the intake passage, and amplifies the intake inertial wave.

A damping pressure wave extraction pipe is provided to communicate a compartment and an intake passage, and guides a pressure wave having a phase opposite to the intake inertia wave to the intake passage, thereby attenuating the intake inertia wave.

A variable mechanism for the pressure wave extraction pipe that selectively conducts the amplification pressure wave extraction pipe at high loads and conducts the attenuation pressure wave extraction pipe at low loads.

(Embodiment) An embodiment of the present invention will be described with reference to FIGS. 1 to 56.

A multi-cylinder diesel engine (hereinafter abbreviated as engine) is shown as the internal combustion engine rgJ1. The engine 1 has an intake system including an intake passage 2, an intake port 3, an intake valve 4, a sill 5, and the like.

The intake passage 2 is composed of an intake main pipe 6, a branch portion 7, a manifold 8, a branch W9, etc. as follows.

Branches f91-96 are connected to shillings 51-5, respectively. Shilling 5. and 56 pairs, 52
and 55, and the set 53 and 54 have the same piston 10 cycle. Schilling 5=, 52.5: l have different piston cycles, and this is the Schilling group A of Ii.
shall be. Furthermore, shillings 54, 57, and 56 have different piston cycles, and are referred to as a second shilling group B.

branch pipes 9 to 9 corresponding to the first shilling group A;
The upstream side of 3 is assembled into the first manifold 8a. Also, the branch t9. corresponding to the 12 Schilling group B. The upstream portions of 96 are collected in the second manifold 8b.

The upstream sides of the first manifold F8a and the second manifold 8b are combined into one main intake pipe 6. Intake main pipe 6
The upstream side of is connected to an air cleaner (not shown).

An intake inertial wave flows through the intake passage 2, and the natural frequency of this intake inertial wave is determined by the length, cross-sectional area, etc. of the intake passage 2. The engine rotational speed with the natural frequency of the intake inertial wave (
An inertial supercharging device matches the opening/closing timing of the intake valve at a synchronized engine speed) so that the intake inertia wave at the intake port becomes a positive pressure immediately before the intake valve closes.

Everything up to this point is the same as the conventional inertial supercharging device.

However, with conventional inertial supercharging devices, it is impossible to improve the volumetric efficiency beyond the intake inertia effect determined by the specifications of the intake passage, and because the volumetric efficiency is high at low loads, there is an inconvenience that pumping loss occurs instead. .

In order to solve this problem, the following mechanism is provided in this embodiment.

The inside of the crankcase 11 of the engine 1 is partitioned by partition walls 12 into adjacent cylinders 5 having different piston cycles, and compartments 13 are provided.

Pressure waves are generated in the compartment 13 by the reciprocating movement of the piston 10. An amplification pressure wave extraction pipe 14 and an attenuation pressure wave extraction pipe 15 that guide this pressure wave to the branch pipe 9 are provided in each compartment 1.
1 and the branch pipe 9 are connected to each other.

A common pipe 16 for both pressure wave extraction pipes is provided protruding from the compartment 13, and an amplification pressure wave extraction pipe 14 and an attenuation pressure wave extraction pipe 15 are branched from the common pipe 16. Both the amplifying pressure take-off pipe 14 and the damping pressure wave take-off pipe 15 superimpose the pressure wave in the compartment 13 on the intake inertial wave in the branch pipe 9.

The pressure wave extraction pipe 14 for amplification superimposes pressure waves on intake inertial waves and amplifies them. On the other hand, the damping pressure wave extraction pipe 15 damps intake inertial waves. Both pressure wave extraction pipes 14 and 15 are designed to have a length and a cross-sectional area that produce pressure waves with a frequency and phase suitable for amplification or attenuation.

The pressure wave extraction pipe may have another structure as follows.

For example, pressure waves taken out from compartments corresponding to the same shilling 5 of the piston cycle, such as compartments 13+ and 136, may be combined and amplified before being introduced into the intake passage. In this case, since the pressure waves are amplified, the effect of amplifying and attenuating the intake inertial waves becomes greater.

A variable mechanism for selectively conducting the amplification pressure wave extraction pipe and the attenuation pressure wave extraction pipe according to the load is provided as follows.

A switching valve 17 is provided at the branching portion of the amplification pressure wave extraction '1llr14 and the damping pressure wave extraction pipe 15.

Each switching valve 17 is connected to a switching shaft 18, and when the switching shaft 18 is rotated, the pressure wave extraction pipe is switched. The switching shaft 18 is transmitted by air cylinder 19. 20 is an air tank that stores compressed air for operating the air cylinder.

On the other hand, 8! load detection means 21 for detecting the load of the connection;
A controller 2 that processes signals from the load detection means 21
2 is provided. Further, a solenoid valve 23 that is operated by a signal from the controller 22 is provided, and this solenoid valve 23
The air cylinder 19 is controlled, and the switching valve 17 is switched through the movement of the switching shaft 18. In other words, switching valve 1
Under the control of the controller 22, 7 conducts the amplifying pressure wave extraction pipe 14 in the case of a high load, and conducts the attenuation pressure wave extraction pipe 15 in the case of a low load.

This embodiment configured as described above operates as follows.

FIG. 6 shows the rotational speed N of the engine 1 and the volumetric efficiency Tic of the intake air.
A characteristic curve showing the relationship is shown. Characteristic curve 2
4o is a characteristic curve in a normal inertial supercharger,
At the tuned rotation speed S, the volumetric efficiency ηC reaches its peak. Further, the phase of this intake inertial wave is shown in FIG. 5(a).

The load detection means 21 detects the load state of the engine 1, and the controller 22 switches the switching valve 17 of the pressure wave extraction pipe as follows according to the load state.

In the case of high load, the pressure wave extraction pipe 14 for amplification is conducted, and the intake inertial wave 25 in the m5 diagram (a) is connected to the m5 having the same phase.
The pressure wave 26 in figure (b) is superimposed, and the suction: A inertial wave 2
Amplify 5. The superimposed intake inertial wave 27 is shown in Fig. 5()1)
The amplitude is large as shown in . The characteristic curve of volumetric efficiency under high load is shifted upward compared to characteristic surface #X24o, as shown at 2411 in FIG.

In other words, when the load is high, the volumetric efficiency 11c of intake air increases and the output increases.

On the other hand, in the case of low load, the damping pressure wave extraction pipe 15 is conducted, and the pressure wave 26' shown in FIG. 5(d), which is in opposite phase to the intake inertial wave 25 in FIG. 5(a), is generated. , superimposed,
The intake inertia wave 25 is reduced. The superimposed intake inertial wave 27' is
As shown in Fig. 15 (e), the amplitude is small. The characteristic curve in the case of low load is shifted downward compared to the characteristic curve 24o, as shown at 241 in FIG.

In other words, when the load is low, the volumetric efficiency ηC of intake air becomes small, so the load on the compression stroke becomes small and the pumping loss is reduced.

Note that the present invention is not limited to the above embodiments. For example, the pressure wave can be introduced not only through the branch pipe but also through the intake passage.

(Effects of the Invention) According to the present invention, when the load is high, the pressure wave extraction pipe for amplification is selectively conducted, thereby increasing the amplitude of the intake inertial wave. On the other hand, in the case of low load, the damping pressure wave extraction pipe is selectively conducted,
Attenuates inspiratory inertia waves.

Therefore, according to the present invention, when the load is high, the volumetric efficiency of intake air is increased to increase the output, but when the load is low, the volumetric efficiency is decreased to reduce the pumping loss.

[Brief explanation of the drawing]

FIG. 1 is a front view of one embodiment of the present invention. Figure 12 is a partially enlarged view of Figure f51. FIG. 3 is a side view of FIG. 1. FIG. 14 is a schematic diagram showing the intake system of FIG. 1. fjS5 (A) to (E) are waveform diagrams showing the operation of the embodiment of FIG. Fig. fjS6 is a characteristic curve diagram of rotation speed vs. volumetric efficiency of the embodiment in Fig. 1.

Claims (1)

[Claims] In an inertia supercharging device for an internal combustion engine that improves the volumetric efficiency of intake air by making the intake inertia wave at the intake port become a positive pressure immediately before the intake valve closes, A compartment chamber is provided in which the same cylinder of the piston cycle is partitioned from each other by a partition wall, and the compartment chamber and the intake passage are provided in communication with each other, and a pressure wave having the same phase as the intake inertial wave is guided to the intake passage, An amplification pressure wave extraction pipe that amplifies the intake inertial wave is provided in communication with the compartment and the intake passage, and a damping device that guides the pressure wave having the opposite phase to the intake passage into the intake passage and attenuates the intake inertial wave. and a variable mechanism for the pressure wave extraction pipe that switches to selectively conduct the amplification pressure wave extraction pipe when the load is high and to selectively conduct the attenuation pressure wave extraction pipe when the load is low. An inertial supercharging device for an internal combustion engine characterized by: