JPH0519526Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a variable resonator device that reduces noise generated by an intake and exhaust system of an engine.

[Prior art and its problems]

The present applicant was the first to apply for this type of device in 1983.
-A device as shown in No. 159418 has been filed.

The device has a structure in which a resonance chamber is connected to a duct through which intake air flows through a tuning pipe.
The purpose is to reduce the noise generated in the engine intake and exhaust system by having the vibration waves of the airflow in the duct reflected in many directions in the resonance chamber and acting to cancel each other out. .

In this case, if the volume of the resonance chamber is V, the length of the tuning pipe is L, the cross-sectional area of the pipe is S, and the speed of sound is C, the resonance frequency is becomes.

In particular, the device uses a sliding piston on one wall of the resonance chamber, and is equipped with a position sensor that detects the position of the sliding piston and an engine rotation speed sensor that detects the engine rotation speed. The sliding piston is displaced by an actuator while comparing output signals, and the volume V of the resonance chamber and the length L of the tuning pipe are simultaneously and continuously variably controlled. Therefore, in this device, the resonance frequency can be changed according to the engine speed,
It is possible to effectively reduce noise in a wide range of resonant frequency ranges.

However, the device proposed in Utility Model Application No. 59-159418 includes a potentiometer as a position sensor, a feedback circuit, etc., and therefore has problems in that the device itself becomes expensive and large. In addition, since electric power is always required, there are problems such as an increase in the load on the battery. Furthermore, there was a problem in that potentiometers and the like had poor durability.

[Purpose of this invention]

The present invention aims to provide a variable resonator device that solves the above problems.

[Summary of the invention]

The present invention was devised in view of the above, and includes a case that is attached to a duct through which intake or exhaust air of an engine flows, and has a resonance chamber whose internal volume can be varied by displacing a movable member, and one end of which is attached to the duct inside the duct. a first tuning pipe that is open and protrudes into the resonance chamber so that the other end faces the movable member and is fixed to the case; and the first tuning pipe is displaceable in the longitudinal direction. The variable resonator device includes an actuator for driving the movable member and the second tuning pipe, the actuator being formed on a main body fixed to the case. a first fluid pressure chamber defined by a first movable wall interlocking with the movable member; and a second movable wall formed on the first movable wall and interlocking with the second tuning pipe. The variable resonator device is characterized by having a second fluid pressure chamber.

[Example of the present invention]

Next, a first embodiment of the present invention will be described with reference to FIGS. 1 to 3.

Reference numeral 2 denotes a duct including first and second passages 2a and 2b extending parallel to each other. First passage 2a
has an inlet 2c at one end for sucking outside air, and a second
The passage 2b has at one end an outlet 2d for sending outside air to an air cleaner device of the engine (not shown).

A variable resonator device 4 includes a case 6, a first tuning pipe 8, a second tuning pipe 10, a movable member 12, and an actuator 16.

The case 6 includes a tubular base 6a that is airtightly fitted over the entire circumference of the other end of the duct 2 and fixed with a screw 17, and a connecting member 18 to the base 6a.
The main body part 6b is connected to the base part 6a through a tubular body part 6b and has the same cross-sectional shape.
The joining member 18 includes a flange portion 18a formed along the inner walls of both portions 6a and 6b and fixed to the inner wall with screws 19, and a partition wall 18b that partitions the inner space of the base portion 6a and the inner space of the main body portion 6b. have. Therefore, at one end of the case 6, the first passage 2a is formed by the base 6a and the partition wall 18b.
A U-turn portion 2e is formed, which is a space where the second passage 2b and the second passage 2b communicate with each other. Also, case 6
A lid member 20 that closes the opening of the main body 6b at the other end is fixed to the main body 6b with screws 21, and the main body 6b, the partition wall 18b, and the lid member 20
A resonance chamber 22 is formed. On the other hand, a partition plate 29 having an opening 29a in the center is arranged in the resonance chamber 22 so as to be perpendicular to the longitudinal direction of the duct 2. is welded to. Note that it is also possible to form a flange portion on the partition plate 29 with a structure similar to that of the joining member 18, and to screw the flange portion to the case 6.

The cylindrical first tuning pipe 8 is arranged along the longitudinal direction of the duct 2 and is connected to the partition wall 1.
The U-turn portion 2e and the resonance chamber 22 are connected to each other by being fixed to the partition wall 18b while passing through the U-turn portion 2e.

The actuator 16 includes a main body 27 having a cylinder 24 fixed to the outer surface of the lid member 20 with a screw 23, and a main body 27 that is slidably fitted into the cylinder 24 to form a negative pressure chamber 24a as a first fluid pressure chamber. In addition, a piston 28 as a first movable wall having a cylinder 26 is provided. Same piston 28
The cover member 20 and the wall portion 27 parallel to the cover member 20
a and are slidably held in a state where they are respectively penetrated. Further, a piston 30 as a second movable wall forming a negative pressure chamber 26a as a second fluid pressure chamber is slidably fitted in the cylinder 26. The negative pressure chambers 24a, 26a are compressed with springs 32, 34 that urge the respective pistons 28, 30 toward the resonance chamber 22 side. Negative pressure chamber 24
a and 26a are the wall portion 27a and the piston 2, respectively.
Connector 4 that is screwed onto 8 and has a passage formed inside.
4, 46, and is connected to a negative pressure source 39 such as a negative pressure tank or the atmosphere via electromagnetic three-way valves 36, 38. These three-way valves 36, 38 can take a position where the negative pressure chambers 24a, 26a communicate with the negative pressure source 39, and a position where the negative pressure chambers 24a, 26a communicate with the atmosphere, respectively. The drive is controlled by the controller 40 in accordance with the control signal output by the rotation speed sensor 41 in response to the rotation speed sensor 41.

The movable member 12 is fixed to the end of a piston 28 that projects into the resonance chamber 22 . Movable member 1
2 by moving together with the piston 28,
It is configured so that it can take a position where it airtightly contacts the partition plate 29 and closes the opening 29a, and a position where it separates from the partition plate 29 and opens the opening 29a as shown in the figure. Further, a rod 31 is protruded from the movable member 12 and extends along the sliding direction of the movable member 12 so as to slidably penetrate the partition plate 29.
The movable member 12 is configured not to rotate relative to the partition plate 29.

On the other hand, one end of a rod 42 passing through the movable member 12 and the partition plate 29 is fixed to the piston 30, and the second tuning pipe 10 is fixed to the other end of the rod 42. By moving together with the piston 30, the second tuning pipe 10 comes into airtight contact with the opening 8a of the first tuning pipe 8 as shown in the figure, thereby increasing the substantial length of the first tuning pipe 8. It is configured so that it can take a position where it is located at a distance from the first tuning pipe 8 and a position where it is away from the first tuning pipe 8.

Then, each three-way valve 3 is controlled by the controller 40.
6, 38 connect the negative pressure chambers 24a, 26a to a negative pressure source 39.
When the pistons 28, 30 are displaced in the direction shown by the arrow A in FIG. 2 against the urging force of the springs 32, 34, the second tuning pipe 10 1, the movable member 12 has a gap with the tuning pipe 8, and the movable member 12 has a gap with the partition plate 29, respectively. Further, the controller 40 causes the three-way valve 36 to operate in the negative pressure chamber 24a.
When the three-way valve 38 is controlled so as to communicate the negative pressure chamber 26a with the atmosphere, the movable member 12 is not displaced;
On the other hand, the piston 30 is displaced in the direction shown by arrow B in FIG.
The tuning pipe 10 is brought into contact with the opening 8a of the first tuning pipe 8. Further, when the three-way valve 36 is driven and controlled by the controller 40 so as to communicate the negative pressure chamber 24a with the atmosphere, and the three-way valve 38 is driven and controlled so as to communicate the negative pressure chamber 26a with the negative pressure source 39, the piston 28 is displaced in the direction shown by arrow B in FIG. 2 due to the biasing force of the spring 32, and the movable member 12 is brought into contact with the partition plate 29.
On the other hand, the piston 30 is displaced in the direction shown by arrow A in FIG. 2 against the urging force of the spring 32, and the second tuning pipe 10 is separated from the first tuning pipe 8. In addition, both negative pressure chambers 24a, 26a
are both connected to the atmosphere, the second tuning pipe 10 connects to the opening 8 of the first tuning pipe 8.
a, and the movable member 12 is brought into contact with the partition plate 29.

That is, according to the above configuration, the rotation speed sensor 4
The actuator 16 controls the second actuator based on the signal outputted by the controller 40 based on the control signal from the first
By controlling the positions of the tuning pipe 10 and the movable member 12, the resonant frequency of the resonator device 4 is set to 4.
It is now possible to switch in stages, which allows noise to be effectively damped over a wide range of frequencies depending on the engine speed, providing a damping effect close to that of the prior art.

Furthermore, since the actuator 16 is of a two-stage operation type in which double pistons 28 and 30 are provided inside which are driven by negative pressure, the second tuning pipe 10 and the movable member 12 can be operated with one actuator. Both can be driven, which has the effect that the device itself can be made more compact. Also, there is no need for a sensor to detect the amount of displacement of the driven part.
Furthermore, since the actuator itself has a simpler structure than other actuators such as step motors, it is inexpensive and has excellent durability. Furthermore, since negative pressure such as intake negative pressure can be used as the driving force, it is possible to avoid negative effects such as increased load on the battery due to the use of the electric motor.

Next, a second embodiment of the present invention will be described with reference to FIG. Note that parts that are substantially the same as those in the first embodiment are designated by the same reference numerals as used above, and detailed explanations thereof will be omitted.

Reference numeral 11 designates a second tuning pipe that is slidable relative to the first tuning pipe 8 and hermetically encloses the same pipe 8, and has an opening 11a formed in the end side wall on the actuator 16 side. There is. One end of a rod 42 is fixed to the actuator 16 side of the second tuning pipe 11, and the other end of the rod 42 is fixed to the piston 30. As the piston 30 slides, the second tuning pipe 11
1 are configured to slide in the same direction.

Therefore, the actuator 16 operates the second tuning pipe 1 based on the signal from the controller 40.
By controlling the positions of 1 and the movable member 12,
The resonance frequency of the resonance chamber 22 can be switched in four stages, and noise can be effectively attenuated over a wide range of frequencies depending on the engine speed.

In addition, since the actuator 16 is of a two-stage operation type in which double pistons 28 and 30 are provided inside which are driven by negative pressure, the second tuning pipe 11 and the movable member 12 can be operated with one actuator. Both can be driven, which has the effect that the device itself can be made more compact. Also, there is no need for a sensor to detect the amount of displacement of the driven part.
Furthermore, since the actuator itself has a simpler structure than other actuators such as step motors, it is inexpensive and has excellent durability. Furthermore, since negative pressure such as intake negative pressure can be used as the driving force, it is possible to avoid negative effects such as increased load on the battery due to the use of the electric motor.

Note that in the first and second embodiments described above, the actuator 16 is driven by negative pressure;
If the vehicle has a compressed air supply source for a horn, air brake, etc., the actuator 16 can be configured to be driven by positive pressure, and the same effect can be obtained in that case. Further, if a hydraulic power source used for brakes, power steering, etc. is provided, the actuator 16 can be configured to be driven by hydraulic pressure, and the same effect can be obtained in that case as well. Therefore, the driving force of the present device can be selected from the one that is easiest to use depending on the fluid pressure supply source of the vehicle type in which the device is installed.

Furthermore, although each embodiment employs the resonator device 4 in the intake system, it goes without saying that it can be similarly employed in the exhaust system.

[Effects of this invention]

According to the present invention, by the actuator driving the movable member and the second tuning pipe,
The resonant frequency of the resonant chamber can be switched to an appropriate value according to the engine speed, and noise can be effectively attenuated over a wide range of frequencies. Furthermore, since the actuator is operated by fluid pressure, it has the advantage of being cheaper than other actuators such as step motors. Furthermore, since fluid pressure is used as the driving force, it is possible to avoid negative effects such as increased load on the battery due to the use of an electric motor, and it is also possible to use an appropriate drive according to the fluid pressure supply source of the vehicle model in which this device is installed. It has the effect of allowing you to choose your strength.

[Brief explanation of the drawing]

FIG. 1 is an overall perspective view showing a first embodiment of the present invention, FIG. 2 is a sectional view taken along the arrow in FIG. 1,
Figure 3 is a sectional view taken along the arrow in Figure 1;
The figure is a sectional view showing a second embodiment of the present invention. 2...Duct, 4...Variable resonator device, 6
...Case, 8...First tuning pipe, 1
0... Second tuning pipe, 12... Movable member, 16... Actuator, 18... Joining member, 20... Lid member, 22... Resonance chamber, 24,2
6...Cylinder, 28, 30...Piston, 3
2, 34... Spring, 36, 38... Three-way valve, 40
... Controller, 41 ... Rotation speed sensor.

Claims (1)

[Scope of utility model registration request] A case that is attached to a duct through which intake or exhaust air flows from the engine and has a resonance chamber whose internal volume can be varied by displacing a movable member, one end of which opens inside the duct and the other end of which faces the movable member. a first tuning pipe opened into the resonance chamber and fixed to the case; and a second tuning pipe disposed so as to be displaceable in the longitudinal direction of the first tuning pipe. The variable resonator device includes an actuator that drives the movable member and the second tuning pipe, and the actuator is configured by a first movable wall that is formed in a main body fixed to the case and interlocks with the movable member. It is characterized by having a divided first fluid pressure chamber and a second fluid pressure chamber divided by a second movable wall formed in the first movable wall and interlocked with the second tuning pipe. Variable resonator device.