JPS59105958A - Resonator - Google Patents

Abstract

PURPOSE:To permit to obtain the frequency of resonance synchronized with the revolving number of an internal-combustion engine by a method wherein an enclosed resonance chamber is provided in a pipeline communicated with the cylinder of the internal-combustion engine and an inside tubular member in the pipeline is displaced by sliding it through the control of a computer. CONSTITUTION:One end of the tubular member 15 being branched on the way of a suction duct 13 is opened in the resonance chamber 16 consisting of an enclosed space. The revolving number of the engine is read in a computer 20, the component of the dominant frequency of suction noise upon each revolutions is computed, a driving signal is sent to an actuator 19 so as to obtain the resonance frequency corresponding to the component of the frequency and the inside communicating tubular member 15b is slided and moved through a shaft 19 to change the resonance frequency. The length of the communicating tubular member 15 of the resonator 17 is changed into an linear actuator 18 in synchronized with the revolving number of the engine, therefore, the resonance frequency may be changed and the suction noise may be reduced.

Description

[Detailed Description of the Invention] ′ Limoto: The invention is based on the invention, in which the resonant frequency is synchronized with the rotation speed of the internal combustion engine.
Enables: resonator, relating to. It is something.

The conventional resonator is the first one. It was configured as shown in the figure.

・'Immediately1. Next, type Φ non-type, the sounder 17 is the intake duct 1
A tubular member 15 is installed in the middle of the intake duct, and communicates with the inner and side suction passages 1 and 4 of the intake duct, and the resonance chambers 1 and 6 have open end surfaces. It was composed of.

The resonant frequency/number fP of this resonator 17 is fP-
C/,,2π・,f[``・/4■・',('Il−+
, l (L,', 8., ``Il:)...calculated by (1). ,,,,1・':.

Here, D is the inner diameter of the communicating tubular member 15o', β is the length of the communicating tubular member 1 and 5, and ■ is the internal volume of the resonance chamber 15. , Therefore, in a conventional resonator, the structure of:
Because of this, the resonance frequencies f and P are uniformly determined, and only the specific resonance frequency fP can be damped.

The present invention (e) In contrast to conventional resonators that can obtain only a specific single resonance frequency, the resonance frequency can be made variable by changing the length ρ of the communicating tubular member shown in equation (1), and the frequency can be controlled. The purpose is to widen the scope.

That is, in order to change the resonance frequency using equation (1), the shape of the communicating bamboo-like member, that is, the shape of the tubular member 1-ID and the length e.
Alternatively, the resonance chamber volume (2) may be made variable.The present invention employs a configuration in which the h and r of the inner tubular member are made variable.

Hereinafter, an embodiment in which the present invention is used as a chanting noise muffling device in an internal combustion engine intake system will be described with reference to FIG.

In the figure, 1 is a cylinder in which a piston 2 is slidably fitted.
Its upper part is covered with a cylinder head 3, and the cylinder head 3 is formed with an intake valve 4, an intake port 6 which is periodically opened and closed by an exhaust valve 5, and an exhaust lower.

The exhaust lower communicates with the exhaust pipe via the exhaust passage 8,
This exhaust pipe has a muffler (not shown) to muffle exhaust noise.
is provided.

On the other hand, the intake port 6 is connected to an intake passage 9 and a carburetor reflex 10 (
It is connected to an air cleaner 11 for purifying intake air via a carburetor 10 (which does not exist in the case of a T-cell vehicle). A suction pipe 12 is attached to the upstream end of the air cleaner 11. An intake tact 13 is connected to the tip of the suction pipe 12, and a tip opening 13a of the intake tact 13 is open to the atmosphere.

A tubular member 15 is branched in the middle of the suction pipe 12 or the suction duct 13 (intake duct 13 in this embodiment). One end of the tubular member 15 communicates with the suction passage 14 in the intake duct 13, and the other end opens into a resonance chamber 16 which is a closed space. A resonator 17 is formed by the tubular member 15 and the resonance chamber 16. The tubular member 15 has a double tube structure, and the outer wall of the inner tubular member 15b is slidable along the inner wall of the outer tubular member 15a. The outer tubular member 15a has one end fixed to the intake duct 13, and the other end 1. j, ++ are fixed to the resonator 17.

On the other hand, the inner tubular member 15b is fixed to the shaft 19ζ of a linear actuator 18, which is fixed to l1tll, which faces the inner tubular part A' 15 of the IITS chamber 1G.

Note that the intake duct 13, the inner and outer tubular members 15a and 15b, and the resonance chamber 16 are blow-molded products of resin. Therefore, 1
The intake duct 13, the outer tubular member 15a, and the resonator 17 described in iiJ are fixed by appropriate means such as adhesion, screwing, tightening, and welding.

Linear actuator 181J An actuator that can electrically easily and accurately control the position in the axial direction,
For example, a step motor is used.

Then, the control computer 20 calculates a resonance frequency in synchronization with the engine rotation based on a rotation signal from a rotation detector (not shown) of the internal combustion engine, and an electric signal based on the calculation is applied to the linear actuator 18. It looks like this. Therefore, the shaft 19 of the actuator 8
The inner tubular member 15b fixed to the computer 20
The inner wall of the outer tubular member 15a is used as a kite to move up and down by an amount corresponding to the electric signal from the outer tubular member 15a.

Details of the inner tubular member 15b are shown in FIG. 15e is a flange for fixing the shaft 19 of the linear actuator 18, and this flange 15e has several (three in the figure) 'IA's.
The surrounding wall 15f is supported by 15C. shaft 19
is inserted into the hole 15d at the center of the flange 15e and fixed by screwing, tightening, or the like. Furthermore, the inner tubular member 15
The outer wall 15f of b) is dimensioned such that its entire surface contacts the inner wall of the side tubular member to prevent air leakage, and it can be slid up and down.

Next, a method of varying the resonance frequency using the resonator 17 will be explained. FIG. 4 shows the relationship between the length of one section of the tubular section l and the resonance frequency when, for example, the volume of the resonance chamber V=1000 cc and the inner diameter of the communicating tubular member is constant, using equation (1) above. . From FIG. 4, for example, if the inner diameter D of the communicating tubular member is 20 mm, the length A of the tubular member is 2Qm.
The resonant frequency fp when m is 160 Hz, and the length of the tubular member is as short as l = 10 mm (then, the resonant frequency fp is 18
By increasing the frequency to εHz, conversely, the length of the tubular member can be increased by C.
-3C-3O, it is possible to lower the resonance frequency rp to 141.

Therefore, the required upper limit resonance frequency fh is determined by -β0 in the state where the length of the communicating tubular member 15 is the shortest, that is, the length of the outer communicating tubular member 15a (as shown in FIG. 5). , the inner communicating tubular member 15b communicates with a linear actuator 18 using a step motor Z, and its length is longer than the movable stroke amount 11 (shown in FIG. 6) of the linear actuator 18, which is longer than the length of the outer communicating tubular member 15a. β0
The shorter length is 2. Hence the linear actuator.

Due to the change in the stroke of 18, the length l of the communicating tubular member changes from C-β0 to ff-1! o+β1 Now the length of the tubular member β0 and the variable amount of the linear actuator! l
, that is, the tubular member length A-1! .

→ Determined by −βl.

Next, a specific resonant frequency range will be determined based on the above-mentioned FIG. 4. For example, the variable material j of the linear actuator 18!
+=10mm, outer communicating tubular member length ffo=20m
m, the upper limit resonant frequency fh is 160 Hz, the lower limit resonant frequency fβ is 1'41 Hz, which corresponds to β-'0''+=30rom, and the linear actuator 18
By moving the inner communicating tubular member 15'b up and down, the noise amount-sound frequency can be changed from 141 Hz to 160 I(z
It can also be made continuously variable.

In the above example, the resonance chamber volume V = 10 (l Oc, , c the force j1 calculated assuming that the inner diameter D + 2 of the inner communicating bamboo-like member = 20 mm) By appropriately selecting both of these, the variable amount β 1 of the same linear actuator can be On the other hand, the variable range of the resonance frequency can be set to a desired range.Furthermore, if the variable amount of the linear actuator is made larger, the variable resonance frequency range can be widened.

Next, an example will be described in which the resonator 17 that performs the above operation is actually used in synchronization with the rotational speed of the internal combustion engine.

As shown in FIG. 2, a rotation signal of the internal combustion engine (obtained from a distributor or a crank pulley, etc.) is input to a control computer 20 using a microcomputer, and the engine rotation speed is read within the computer 20. Calculate the dominant frequency components of the intake noise. Then, a drive signal is sent to the actuator 18 so as to obtain a resonance frequency corresponding to that frequency component,
The resonant frequency is changed by sliding the inner communicating tubular member 15b via the middle lift l'''9. The above control flowchart is shown in FIG.

In order to control in this way, it is possible to move the linear actuator 18 in the forward and reverse directions even when the rotational speed of the internal combustion engine increases or decreases, so that the resonance frequency can always be varied in synchronization with the rotational speed. can.

Further, as a method of synchronizing the engine speed, as shown in FIG. 8, the engine speed can be directly and continuously synchronized from obtaining the resonant frequency variable range f to fh, or it can be synchronized in a stepwise manner. It can be synchronized freely by the control computer.

In this way, in the resonator 17 of this example, the length of the communicating tubular member 15 of the resonator 17 is changed by the linear actuator 18 in synchronization with the engine speed, so the resonance frequency can be made variable. . Therefore, the frequency range in which the damping effect can be obtained can be made wider than that of conventional resonators.

□FIG. 9 shows the intake noise reduction effect caused by using the resonator 17 in an internal combustion engine. Thin tooth width line A is the intake noise when the resonator 17 is not installed, and as is clear from the figure, there is a large noise peak around 40'O' 0 to 4800 rpm, which is a problem. . This noise peak is the second order component of the engine speed, that is, from 133H2 to 16
0 Hz is dominant. Therefore, by changing the resonant frequency variable range of the resonator 17 from 141H2 to 160Hz synchronously from 4230 rpm to 4800 rpm using the variable amount (10 mm) of the linear actuator 18 described above, the range shown by the thick line in the figure is changed. As shown in , intake noise can be significantly reduced compared to the conventional resonator installation (dotted chain line in the figure).

Note that the resonator 17 of this example can also provide the following effects.

! ! II et al., the natural resonance frequency of the intake passage pipe of the intake air in the intake system and the opening/closing frequency of the intake valve 4 should match. is well known, and for this reason, conventionally, the quality of the intake pipe for "C" has been selected so that resonance can be obtained at a certain rotation speed of the internal combustion engine (1), and the engine output at that rotation is increased.

Therefore, by installing the resonator 17 in the middle of the suction pipe and making its resonance frequency variable, the natural resonance frequency of the suction/i≧body can be changed. Synchronization can also act as a means to increase output over the entire rotation range of the internal combustion engine.

Although the above-mentioned examples are desirable embodiments of the present invention, the present invention has various embodiments in addition to the above-mentioned examples.

That is, in the above example, the linear actif and the eater 18 were attached to the resonator 17, but as shown in FIG.
It may be installed on the third side. Furthermore, as shown in FIG. 11, it is also possible to separate the resonator mounting part 21 from the intake duct 13 in consideration of the ease of mounting, so that the mounting position can be changed freely. .

Furthermore, in the embodiment described above, the resonator 19 is arranged on the suction line,
The same effect can be obtained by using it as an intake noise reduction method, or by installing the same (14-component) resonator in the IJ1 gas system and implementing it as an exhaust noise reduction device.

As explained above, in the resonator of the present invention, the length of the communicating tubular member of the resonator is variably controlled in accordance with the rotation speed of the engine, so that the number of resonators S can be obtained in accordance with the operation of the engine. It has an excellent effect of being able to do things.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a conventional resonator, FIG. 2 is a configuration diagram showing an embodiment of the resonator of the present invention installed in an internal combustion engine, and FIG. A perspective view of the member, FIG. 4 is an explanatory diagram showing the relationship between the shape of the communicating tubular member of the resonator and the resonant frequency, and FIGS. 5 and 6 are cross-sectional views showing how the resonant frequency changes by the resonator shown in FIG. 2. , Fig. 7 is a control flowchart of the resonator shown in Fig. 2, Fig. 8 is a characteristic diagram showing the control relationship between the engine speed and -J (sounding frequency), and Fig. 9 is a graph showing the intake noise of the resonator shown in Fig. 2111. 1, 10, and 11 are sectional views showing other embodiments of the invention resonator. 1. Internal combustion engine cylinder, 4.・Suction valve, 5...
Exhaust valve, 9... Intake passage, 12... Intake pipe, 13.
・・Intake tact, 1 lI・・Suction path, 15 ・Communication tubular part, 1.5 a ・Outside communication bamboo member, 15b・
- Inner communicating tubular part, 16... Resonance chamber, 17... Resonator, 182'a') Near Acnap, Eta, 20 unit controller I-roll computer. Representative Patent Attorney Oka Rjlj Ryudai 5 [Ku No. 6 Diagram σ D ○ Diagram 8 @ Mamura Tenra (+':l), m)

Claims (3)

[Claims] (1) A winter side tubular member having one end open to a passage leading to a cylinder of an internal combustion engine, a resonance chamber consisting of a sealed space communicating with the other end of this outer tubular member, and a resonance chamber slidably arranged in the outer tubular member rt. a linear actuator that displaces the inner tubular member based on an electrical signal; 1. A resonator comprising a control beer combination and unit that detects the QO rotation speed of the internal combustion engine and controls an electric signal applied to the linear actuator.
. (2) One end of the outer tubular member WW is opened to the intake duct, and the control combination unit calculates the resonance frequency according to the rotational speed of the inner 148M motor, and obtains the resonance frequency. Our resonator according to claim 1 outputs an electric signal to.
, (3) One end of the outer tubular member opens to the suction pipe, and the controller/j<combination calculates a resonant frequency corresponding to the steady-state frequency of opening and closing of the silent intake valve of the internal combustion engine, and calculates the resonance frequency. The resonance chamber according to claim 1, wherein the resonance chamber outputs an electric signal to the linear actuator.