KR20000016206A - Airflow device - Google Patents

Abstract

PURPOSE: An absorbing device for an inner combustion engine is provided to receive an instrument for changing the passage of the air being absorbed in an absorbing route area. CONSTITUTION: The invention relates to an airflow device in which there are adjusters in the flow path to alter the flow geometry of the air. The total cross-section of the flow path is divided into individual flow channels (15, 16, 17) or tube sections (1, 3, 4) one inside the other and there are means or adjusters (13, 14) by means of which the flow paths in the individual flow channels (15, 16, 17; 1, 3, 4) can be controlled. In a preferred embodiment there are three flow channels (15, 16, 17), the ends of which are connected to an internal aperture (22 to 27) in the adjusters (13, 14).

Description

Airflow device

The present invention relates to an air through-flow device for a unit, such as an internal combustion engine, which requires a certain amount of air for operation. In particular, the invention relates to an airflow device provided with a setting device in the flow path region for changing the trajectory of passage for air passing therethrough. Moreover, the present invention relates to an intake apparatus for an internal combustion engine provided with means for changing the passage path for the air sucked in the intake path region.

For example, in order to ensure optimum operating performance in known automotive internal combustion engines, it is desirable to provide different intake lengths in the intake system to meet different needs when driving the engine. Here, suppression of noise also plays an important role.

For example, an intake device for an internal combustion engine is introduced in DE-OS 40 41 786, where a controllable valve is provided to change the intake opening through which the air sucked in the flow state passes. The valve is located in a transverse duct located between two intakes and is opened and closed by a control command from the control electronics. The control commands depend on the speed of the internal combustion engine and the temperature of the outside air as determined by the temperature sensor.

Selective closure of cylinders on internal combustion engines is frequently performed to reduce the distance associated with fuel consumption by improving the efficiency of energy conversion of the internal combustion engine over the operating range far below the nominal capacity of the engine. In addition to the usual throttle valve, it is also possible to reduce the number of cylinders acting for the purpose of controlling engine torque. Cylinders that do not contribute to torque act as a mechanism, but fuel supply is not achieved. As such, the pulsation of the air sucked in closing the cylinder also changes.

A typical use of such a cylinder closure is to convert a six cylinder internal combustion engine from six cylinders to three cylinder operating mode. Considered separately, even though the suction pulses from each of these cylinders of the suction device remain unchanged, the six-cylinder periodic interaction exhibits a different pulsation tendency than the three-cylinder pulsations. In particular, since the coarse low humming sound is invasive, this low frequency component can only be reduced by a complex baffle silencer (ie, a Helmholtz resonator).

However, in many other applications, the resonance performance of the inhalation device also plays an important role, and the available space also frequently constitutes a threshold.

It is an object of the present invention to provide an airflow device in which a setting device is provided in the region of the flow path for changing the passage trajectory for passing air, and a means for changing the passage trajectory for the sucked air in the region of the intake path. It is a simple method of retrofitting the intake apparatus for an internal combustion engine that is provided and provided the optimum operating conditions, in particular the optimum noise level, for the different operating states of the connected units.

In the airflow device according to the present invention, the entire cross section of the flow path is subdivided into respective flow paths in the flow direction, the flow path of each flow path is controllable by a setting device, and at least two internal parts in the pipe part in the intake path. A pipe is provided, the diameter of the pipe being dimensioned to allow the first inner pipe and the second inner pipe to slide one pipe in the other pipe of the pipe part, and the means for changing the intake path is provided in the pipe part. Wherein said means flows through a pipe section with parallel inner pipes or through an intermediate space between the pipe section and the inner pipe and through the innermost first inner pipe, the space being This object is fulfilled by the feature of the airflow device connected in series in a mutually displaced direction. The airflow device according to the present invention is capable of adopting various operating conditions, for example, by changing the intake path and the intake trajectory, particularly when the number of cylinders of an internal combustion engine changes, particularly for optimization of noise emission. Particularly effective.

The present invention describes, in particular, a flexible system for intake of varying amounts of air under pulsating flow conditions. By means of the two setting devices according to claim 1 it is possible to provide a change in the sound transmission path or the flow path located between the two setting devices, for example via three or more flow ducts of the flexible tube. . In an embodiment according to the invention, it is possible in each case one valve of each setting device to set two setting positions, through which the long, narrow or short and wide flows are changed by changing the direction of the flow airflow. It is possible to provide a path, or a sound transmission path.

On the intake side, the airflow device as a whole includes an air filter having an air intake port. This component forms a series of locked Hermholtz resonators whose resonance frequencies correspond to the formula below.

f _res =

f _res = resonance frequency

A = cross section of the final flow path

l = length of final flow path

V = volume of downstream air filter

By opening the three channels in parallel and expanding the cross section, the resonance frequency increases three times, and with the series connection of the three channels, the resonance frequency decreases by one third when the length is extended. In an embodiment, the low value is 25 Hz and the high value is 75 Hz. Attenuation begins with sound above the frequency of 35 Hz or 106 Hz.

According to one embodiment, the valve stems of the two setting devices can be firmly coupled to each other, whereby a simple device is provided to ensure the above-mentioned conditions. Thus, the setting devices can be mounted in contact with each other or one on top of the other, so that the two stems of the valves can be interconnected very easily and only one actuator is required for operation. For a more precise setting, the two valves are biased springs.

According to another embodiment, it is possible to set a third setting position for the valve so that only one valve is moved so that the valve can set a different setting position. For example, in a setting position including a long narrow passage, when only one valve is moved, the length of the damping passage is reduced by a factor 3 and the cross sectional area remains the same. Thus, the resonance frequency is increased by the coefficient √3, which can assume the value 43.3 Hz according to the embodiment described above, and this intermediate position can be used for the average speed range of the internal combustion engine.

In the last illustrated embodiment, mechanical actuation is possible by means of a pulling cam or valve stem, so that each other valve is not driven jointly through a particular rotation angle range in which the valve directly driven.

In a preferred use of the invention, ie when operating an internal combustion engine having a different number of cylinders, the noise emission is significantly different. The frequency characteristics of the intake pulses are determined not only by the cylinder pulse vibrations, but also by the harmonics, and the frequency characteristics of the six-cylinder engines can be explained by the interaction of sinusoidal oscillations of the sixth and twelfth harmonics. And the amplitude is significantly smaller than the amplitude of the cylinder pulse. On the other hand, only the cycle of the three-cylinder engine substantially fluctuates due to the sine wave of the third harmonic, so that the amplitude increases to a value beyond the value of the individual pulses, representing a 13 dB difference in the emitted noise level.

According to the present invention, noise divergence can be effectively reduced when working with a closed cylinder having a “long and narrow” flow routing position.

In particular, the humming sound, which is very loud on engine acoustics under full-load operation, resonantly amplified in current vehicle designs, reaching the passenger's ear and transmitting very easily inside, is successfully suppressed.

According to the foregoing, not only the volumetric capacity of the suction device, but also the dimensions of the so-called acoustic neck of the induction manifold are also very important for the damping effect for noise reduction. Attenuation begins at a moderate low frequency, the narrower the narrower, the longer the tube. In particular, as described in claims 6 to 12, it is also possible in an embodiment according to the invention to provide an elongated and narrowed intake path in order to effectively improve the attenuation of low frequency components. It is also possible to change the direction of sucked air by a simple mechanical displacement of one of the two inner pipes.

Further effective improvements of the invention are described in the dependent claims.

Embodiments of the airflow device according to the present invention will be described in more detail with reference to the drawings.

1 shows a cross section of a first embodiment with a pipe section of a suction device having two inner pipes in an initial state.

Figure 2 shows a cross section of the tube part of the suction device with two inner pipes in the converted state.

3 and 4 show vibration performance of a three-cylinder engine and a six-cylinder engine.

5 shows a curve of the attenuation effect of the acoustic neck on frequency due to different numbers of cylinders.

6 shows another preferred embodiment illustrating the principle of an airflow device with three controllable flow paths.

7 shows in detail the setting device according to FIG. 6 with a movable valve on the flow path.

FIG. 1 shows a first embodiment with a pipe section 1 of an intake apparatus for an internal combustion engine, not shown here, through which the air flow stream is indicated by an arrow 2 or an arrow ( 2.0, 2.1, 2.2). The first inner pipe 3 is installed in the pipe 1 and is firmly connected concentrically to this pipe. An axially displaceable second inner pipe 4 is inserted between the first inner pipe 3 and the inner wall of the pipe section 1. The second inner pipe 4 can be displaced in the axial direction until it is sealed and leaned on the stop plate 5. In this case, the stop plate 5 also acts as a fastening means for the first inner pipe 3.

The first inner pipe 3 has a number of windows 6 at the lower end of the stop plate 5, and if the second inner pipe 4 according to FIG. 1 is not pushed down, this window is opened. The air sucked in can flow into the interior of the first inner pipe 3. At the upper end of the displaceable second inner pipe 4, a number of windows 7 and a sealing disc 8 are provided, the function of which will be described below with reference to FIG. 2. According to FIG. 1, the sucked air flows in parallel (in the direction of the arrows 2.0, 2.1, 2.2) through the intermediate spaces 9, 10 and the inner pipe 3.

In this embodiment, before converting from six-cylinder operation to three-cylinder operation, the movable inner pipe 4 is positioned as shown in FIG. It passes through to enable parallel flow. The flow path is (L) and the flow cross section has a value of 3 * A, where A is the surface area of the cross section of one of the three pipe spaces.

In FIG. 2, the second inner pipe 4 is pushed down and sealed against the bottom toward the stop plate 5. Therefore, the sucked air flows through the first intermediate space 9 (in the direction of the arrow 2.3), and then is guided through the sealing disk 8 to the window 7 at the right end, and the second intermediate space. (10) flows backward in the direction opposite to the intake direction (in the direction of the arrow (2.4)). At the end of the intermediate space 10, air flows through the window 6 into the inner pipe and in the direction of the arrow 2.5. Thus, according to FIG. 2, a flow path is provided, which flows from the outside to the inside three times the length of the pipe 1.

After switching from six-cylinder operation to three-cylinder operation, the movable second inner pipe 4 according to the invention is located in the left stop position as shown in FIG. 2. The flow path here is 3 * L and the flow cross section is A. Dividing the cross section by 3 and multiplying the flow path by 3 can be considered to take neutrality for the flow resistance, because in parallel with the conversion to the flow path according to FIG. 2, the engine operating state can be adjusted simultaneously. As such, a correspondingly low air volume flow can be made due to the reduced power demand.

The attenuation behavior of the suction device according to the above embodiment will be described with reference to FIGS. 3 to 5.

FIG. 3 shows the periodic sequence of pulse trains of suction pulses for three cylinder operation, and FIG. 4 for six cylinder operation.

The cycle of the six-cylinder engine according to FIG. 4 shows the combined effect of the sinusoidal vibrations of the sixth to twelfth harmonics of the 720 ° operating cycle, and the amplitude of the synthesized vibration is significantly smaller than the amplitude of the individual pulses. Can be. On the contrary, the three-cylinder period according to FIG. 3 actually oscillates only with the sinusoidal vibration of the third harmonic, so that the amplitude becomes larger than the value of the individual pulses. For example, for an engine speed of 3000 r / min, an interference frequency of 150 Hz is created in six cylinder operation, while an interference frequency in three cylinder operation is 75 Hz.

On a purely mathematical basis, when converting from six-cylinder operation to three-cylinder operation, an amplitude ratio of 1: 4.5 is created, representing a noise level difference of 13 dB.

5 shows the attenuation curves over frequency for two operating states. Curve 30 represents the decay order in six-cylinder operation, and curve 31 represents the decay order in three-cylinder operation.

When optimizing the damping performance, it should be noted that not only the volume size but also the dimensions of the acoustic neck are very important for the damping effect. The longer and narrower the tube, the lower the frequency at which attenuation will begin. The ultimate goal of the acoustic effort is to go below the excitation frequency with the resonant frequency F _res since the desired attenuation starts from the value of √2 * f _res only.

Thus, when switching from six-cylinder operation to three-cylinder operation, if there is no increase in the noise level, the resonant frequency of the damping pipe section 1 has the result that the coefficient should be reduced by 3.77. This results in a deformation of the dimensions of the damping neck, i. As shown in FIG. 5, in this temporary design of six-cylinder operation, the resonance frequency is 66 Hz, while the attenuation can be 12 dB at 150 Hz (curve 30). After conversion to three-cylinder operation, the excitation frequency is 75 Hz, and the attenuation reaches 25 dB due to the larger excitation of 13 dB.

By the suction device according to the illustrated embodiment, the acoustically weighted level is fixed, since the sound of 75 Hz is weighted at 9.5 dB (A) lower than the 150 Hz sound. In this respect, the modulation for the resonant frequency of 22 Hz is sufficient, which constitutes the frequency lowered by the coefficient 3. The current 75 Hz sound is attenuated by 20 dB (curve 31). According to the embodiment according to the invention shown in FIGS. 1 and 2, a three-fold increase in the length of the attenuating neck and a third reduction in the surface area cross section are possible, producing the desired result.

6 shows a further preferred embodiment 11 of the airflow device according to the invention, which allows air to pass in the direction of the arrow 12. The flow paths 15, 16, 17 are installed between the two setting devices 13, 14, and the flow direction in the flow paths 15, 16, 17 can be varied by the valves 18, 19 (here Not visible). Since the flexible material is preferable as the flow paths 15, 16, and 17, such an airflow device 11 can be accommodated on the unit at a point where there is not much space available (for example, an engine mount of an automobile).

7 shows the setting devices 13, 14 and the valves 18, 19 shown in detail. As mainly shown in FIG. 6, the valves 18, 19 are rotatable about the valve stems 20, 21, which valves 20, 21 can be mechanically connected to each other.

When the valve 18 is installed in the setting device in the position shown in FIG. 6, the flow airflow is guided through the bottom opening 22 in the direction of the arrow 12 (see FIG. 6) into the flow tube 15. , To the opening 23 of the setting device 13. By determining the position of the valve 19 in the setting device 13, air is subsequently guided through the opening 24 into the flow path 16 to reach the opening 25 of the setting device 14. Due to the position of the valve 18, the air is here also directed backwards into the flow path 17 via the opening 26, and reaches the setting device 13 via the opening 27, and the setting device is removed. Passage allows air to flow outward.

The flow path described above thus comprises a series connection of flow paths 15, 16, 17, resulting in a long and narrow damping flow path.

In the optional position of the valves 18, 19, ie in each open state shown here by dashed lines, all the openings of the setting components 13, 14 are opened so that air flows through all the flow paths 15, 16, 17. Can flow in parallel. Thus, this creates a short and wide flow path through the flow paths 15, 16, 17.

In the illustrated embodiment, the stems 20, 21 of the valves 18, 19 are mutually mechanically connected so that generally two valves are jointly in parallel if one assumes the same position in each setting device 13 or 14. It is regulated and driven by a servomotor. Each indirectly induced valve 18 or on one of the valve stems 20 or 21, ie on a valve stem directly actuated or indirectly induced, respectively, by means of a pulling cam not shown here. 19) is possible to remain in the predetermined angular area at the initial position, thereby providing another setting position.

In this finally mentioned setting position, air passes through only one of the flow paths 15, 16 or 17, so that, for the first mentioned setting position, there is a reduction in the length of the flow path by the factor 3, but with the same cross section. Keep it. As each driven stem is further rotated, the pulling cam acts to reach a setting position that provides parallel flow.

Reference

1: tube

2: arrow (flow airflow)

2.0 to 2.5: arrow (flow airflow component)

3: first inner pipe

4: second inner pipe

5: stop plate

6, 7: windows

8: sealing disc

9, 10: middle space

11: Example with a flexible flow path

12: arrow (flow airflow)

13, 14: setting device

15, 16, 17: Euro

18, 19: valve

20, 21: valve stem

22 to 27: opening of setting device

30, 31: attenuation performance curve

Claims (17)

In the airflow device provided with the setting device in the flow path area for changing the trajectory of the passage air, the entire cross section of the flow path is subdivided into respective flow paths 15, 16, 17 in the flow direction, and each of Air flow device, characterized in that the flow path of the flow path (15, 16, 17) is controllable by the setting device (13, 14). 3. A flow path according to claim 1, wherein three or more flow paths (15, 16, 17) are provided, the ends of which are connected to respective inner openings (22 to 27) of the setting devices (13, 14), and valves 18, 19 are provided to the respective setting devices 13, 14, the valve being in the first setting position through the flow path 15, 16, 17 from the inlet on the first setting device 13; Directs the flow airflow (arrow 12) in the diverted flow direction, continues to the outlet on the second setting device 14, and in the second setting position the valve directs the flow airflow (arrow 12) A device characterized in that it leads in parallel from the inlet on the first setting device (13) to the outlet on the second setting device (14) via the flow path (15, 16, 17). 3. The valve (18) of claim 2, wherein the valves (18, 19) are supported to rotate on the respective stems (20, 21), wherein air in the first setting position by the valves (18, 19) passes through all three flow paths. Flowing in parallel, and in the second setting position by the valves 18, 19, the two openings 25, 26; 23, 24 of each setting device 13, 14 are sealed so that the inlet or outlet is closed. Sealing towards the air, characterized in that air can flow between the openings (25, 26; 23, 24) on the side facing the flow path (15, 16, 17). Device according to claim 3, characterized in that the stems (20, 21) of the two valves (18, 19) are firmly interconnected and are driven jointly by a servomotor. 4. The stem (20) and (21) of the two valves (18, 19) are jointly driven and interconnected by a servomotor, so as to be directly driven or indirectly guided stems (20, 21). It is provided with a pulling cam, characterized in that only the stem (20, 21) which is directly driven within a certain rotational angle range regulates the valve. In the intake apparatus for an internal combustion engine provided with means for changing the trajectory of inhaled air in the region of the intake path, the pipe section 1 is provided with two or more internal pipes 3, 4 in the intake path. The diameter of the pipe is dimensioned so that the first inner pipe 3 and the second inner pipe 4 are designed to slide together in the pipe part 1, and the means for changing the intake path is a pipe part ( 1), by which means air flows through a pipe section 1 with parallel inner pipes 3, 4 or in an intermediate space between the pipe section 1 and the inner pipes 3, 4 ( A suction device, characterized in that it flows through 9, 10, flows through the innermost first inner pipe (3), and the spaces are connected in series in mutually displaced directions. The method according to claim 6, wherein the first inner pipe (3) is rigidly fixed to the pipe section (1), and at least one window (6) is provided to allow air to flow into the first inner pipe (3), and the opening The second inner pipe (4) with a seal (7) and a sealing means (8) is designed to slide up in the first pipe part (1) over the first inner pipe (3), so that in the initial position the air is all intermediate Flows in parallel through the spaces 9 and 10 and through the first inner pipe 3, at the transformation position a series connection of the next intake path is provided, In the intake direction, air flows through the first intermediate space 9 between the pipe section 1 and the second inner pipe 4, At the end of the first intermediate space 9, air flows in the opposite direction through the intermediate space 10 between the first inner pipe 3 and the second inner pipe 4, and At the end of the second intermediate space (10), air reaches the first inner pipe (3) and flows from the pipe section (1) in the intake direction (2). 8. A connecting path (arrow, 2) from the intermediate space 10 to the outlet duct in the transformation position is arranged in accordance with the first inner pipe across the intake side end of the second inner pipe 4. Made by one or more windows 6 of (3), the second inner pipe (4) having one or more windows (7) for connecting the first intermediate space (9) and the second intermediate space (10) ), And a sealing ring (8) for sealing the two intermediate spaces (9, 10) outwardly is provided at the other end of the displaceable second inner pipe (4). 9. The stop plate (5) according to claim 7 or 8, wherein the stop plate (5) is provided with an opening for air (arrow (2)) in the intake path, the plate also having the second displaceable inner pipe (4) at the transition position. Forming a limit stop for one end of the device, said first fixed inner pipe (3) being fastened on said plate. 10. The device according to claim 7, wherein the second inner pipe (4) is displaceable on a support component fastened on the outside of the first fixed inner pipe (3). 11. Device according to one of the claims 7 to 10, characterized in that the second inner pipe (4) is displaceably fastened on a support component fastened on the interior of the pipe section (1). 12. The hydraulic pressure of the motor vehicle according to any one of claims 7 to 11, wherein the switching pulse required to displace the second inner pipe 4 is a coefficient that depends on a number of working cylinders of the internal combustion engine. Device generated by the system. The device according to any one of claims 1 to 12, which is an intake device for an internal combustion engine for automobiles. 16. The apparatus of claim 15, wherein the vehicle has a device for closing a plurality of cylinders of an internal combustion engine. The apparatus of claim 1, wherein the apparatus is illustrated and illustrated herein. 7. An apparatus as claimed in claim 6, characterized by what is illustrated and illustrated herein. A new device characterized by what is illustrated here.