JPH0663812U - Active silencer - Google Patents

Abstract

(57) [Abstract] [Purpose] The present invention relates to an active silencer in which the noise of exhaust gas is positively silenced by a speaker, and reliably prevents the permanent magnet of the speaker from becoming hot. With the goal. A metal silencer body 61 is partitioned by a partition wall 62 to form a silencer chamber 65 and a speaker chamber 67, an exhaust pipe 69 is connected to the silencer chamber 65, and a speaker 75 is housed in the speaker chamber 67. In the active silencer, the outer cylinder 62 of the silencer body 61 is configured to contact the speaker body 41 of the speaker 75 directly or via a heat transfer member.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an active silencer in which noise of exhaust gas is positively silenced by a speaker.

[0002]

[Prior art]

 Conventionally, as an active silencer in which noise of exhaust gas is positively silenced by a speaker, for example, one disclosed in Japanese Patent Laid-Open No. 3-174198 is known.

FIG. 4 shows an active silencer of this type. In the figure, reference numeral 11 denotes a silencer body. The muffler body 11 is divided into three parts by a partition wall 13 arranged at a predetermined interval, a muffling room 15 is formed in the center, and speaker rooms 17 are formed on both sides of the muffling room 15.

An exhaust pipe 19 that circulates the exhaust gas G is inserted into the muffler chamber 15. The exhaust pipe 19 has a large number of small exhaust pipes in a portion located inside the muffler chamber 15. The hole 21 is formed.

An opening 23 is formed in the pair of partition walls 13 at a position facing each other around the exhaust pipe 19, and a speaker 25 as a secondary sound source is arranged in the opening 23. A protective plate 27 for protecting the speaker 25 is arranged in the opening 23 of the partition wall 13, and a large number of small holes 29 are formed in the protective plate 27.

A sound absorbing material 31 made of, for example, glass wool is housed in the muffling room 15 and the speaker room 17. In addition, a microphone 33 is arranged in the muffling chamber 15.

In such an active silencer, the noise of the exhaust gas G is detected by the microphone 33, and the erasing sound having a phase opposite to the detected noise is emitted from the speaker 25, so that the so-called active muffling is performed. Is done.

FIG. 5 shows the details of the speaker 25 described above. In the figure, reference numeral 41 denotes a speaker body including a frame portion 41a and a bottom portion 41b. A center pole 43 is arranged in the center of the speaker body 41, and one end thereof is fixed to the bottom portion 41b of the speaker body 41.

A voice coil 45 is arranged outside the center pole 43, and one side of a diaphragm 47 made of, for example, cone paper is connected to the voice coil 45.

A cap 49 is arranged in the center of the vibration plate 47, and the other side of the vibration plate 47 is connected to the tip of the frame portion 41 a via an edge 51. An annular permanent magnet 53 is arranged outside the center pole 43 at a predetermined distance from the center pole 43.

[0011]

[Problems to be solved by the device]

 However, in such a conventional active silencer, the heat of the exhaust gas from the small hole 21 of the exhaust pipe 19 located near the speaker 25 reaches the speaker 25 in a relatively short distance. However, there is a problem that a large heat load is applied to the permanent magnet 53 and the function of the permanent magnet 53 may be deteriorated.

That is, as the diaphragm 47 of the speaker 25, a material having high heat resistance made of aluminum or the like instead of paper has been developed. At present, however, a material having high heat resistance has been developed as the permanent magnet 53. However, since the Curie point is as low as 80 to 90 ° C., for example, there is a problem that from the time when the ambient temperature passes the Curie point, the function as a magnet is lost and the ferrite becomes mere ferrite.

The present invention has been made to solve such a conventional problem, and an object of the present invention is to provide an active silencer capable of reliably preventing the permanent magnet from reaching a high temperature.

[0014]

[Means for Solving the Problems]

 In the active silencer of the present invention, the silencer body made of metal is partitioned by a partition wall to form a silencer chamber and a speaker chamber, an exhaust pipe is connected to the silencer chamber, and a speaker is housed in the speaker chamber. In the active silencer, the outer cylinder of the silencer body is in contact with the speaker body of the speaker either directly or via a heat transfer member.

[0015]

[Action]

 In the active silencer of the present invention, since the outer cylinder of the silencer body is brought into contact with the speaker body of the speaker directly or through the heat transfer member, the heat of the speaker body is silenced directly or through the heat transfer member. The heat is transmitted to the outer cylinder of the container body and radiated to the outside from the outer cylinder.

[0016]

【Example】

 Hereinafter, the details of the present invention will be described with reference to the embodiments shown in the drawings. 1 and 2 show an embodiment of the active silencer of the present invention. In the drawings, reference numeral 61 denotes a silencer body composed of an outer cylinder 62 and an end plate 64.

The muffler body 61 is divided into three parts by a pair of partition walls 63 arranged at predetermined intervals, a muffling chamber 65 is formed in the center, and speaker chambers 67 are formed on both sides of the muffling chamber 65. ing.

An exhaust pipe 69 that circulates the exhaust gas G is inserted into the muffler chamber 65, and a large number of small exhaust pipes 69 are provided throughout the exhaust pipe 69. A hole 71 is formed.

An opening 73 is formed in the pair of partition walls 63, and a speaker 75, which is a secondary sound source, such as a round speaker, is arranged in the opening 73. A protective plate 77 for protecting the speaker 75 is arranged in the opening 73 of the partition wall 63, and a large number of small holes 79 are formed in the protective plate 77.

A sound absorbing material 81 made of, for example, glass wool is housed in the muffling room 65 and the speaker room 67. A microphone 83 is arranged in the muffling room 65.

In this embodiment, however, the outer cylinder 62 of the muffler body 61 is connected to the speaker body 41 of the speaker 75 by a heat transfer member 85 made of, for example, metal such as iron or aluminum that has good heat conduction. Are being contacted through.

That is, as shown in FIG. 3, the heat transfer member 85 has a bottomed circular tubular shape, and a circular edge portion 85b is formed on one side of the tubular portion 85a. . Further, the bottom surface portion 85c is formed with a protruding portion 85d which is linearly extended outward.

On the other hand, a circular hole portion 62a is formed in the outer cylinder 62 of the silencer body 61, and an edge portion 85b of the heat transfer member 85 is fixed to the outer side thereof by welding W, for example. Then, the bottom surface portion 85c of the heat transfer member 85 is brought into contact with the bottom portion 41b of the speaker body 41 and joined by welding or the like.

Since the speaker 75 has the same configuration as the speaker shown in FIG. 5, the same parts are designated by the same reference numerals, and detailed description thereof will be omitted. In the above-described active silencer, the noise of the exhaust gas G is detected by the microphone 83, and the erasing sound having a phase opposite to the noise is emitted from the speaker 75, so that the so-called active muffling is performed.

In the above-described active silencer, however, since the outer cylinder 62 of the silencer body 61 is brought into contact with the speaker body 41 of the speaker 75 via the heat transfer member 85, the heat of the speaker body 41 is reduced. Is transmitted to the outer cylinder 62 of the silencer main body 61 via the heat transfer member 85 and is radiated to the outside from the outer cylinder 62, so that it is possible to reliably prevent the permanent magnet 53 from reaching a high temperature.

Further, since the protruding portion 85d is formed on the bottom surface portion 85c of the heat transfer member 85, the air inside the speaker chamber 67 can circulate in the space inside the protruding portion 85d, and the external The air can cool the air in the speaker room 67.

Further, in the above-described active silencer, since the center pole 43 is fixed to the bottom portion 41b of the speaker body 41, the heat generated by the electric eddy loss of the center pole 41b due to the electric field is transmitted via the heat transfer member 85. It can effectively dissipate heat to the outside.

In the above-described embodiment, an example in which the outer cylinder 62 of the silencer body 61 and the heat transfer member 85 are separately configured has been described, but the present invention is not limited to this embodiment. Instead, the heat transfer member may be integrally formed on the outer cylinder, and the heat transfer member may be directly contacted with the speaker body.

Further, in the embodiment described above, an example in which the heat transfer member 85 is fixed to the outer cylinder 62 of the muffler body 61 by welding or the like has been described, but the present invention is not limited to this embodiment. Instead, for example, the heat transfer member 85 is detachably fixed to the outer cylinder 62 of the silencer body 61 with a bolt or the like, so that the speaker 75 can be easily attached to and removed from the silencer body 61 together with the heat transfer member 85. Therefore, the speaker 75 can be assembled or maintained very easily.

[0030]

As described above, in the active silencer of the present invention, the outer cylinder of the silencer body is brought into contact with the speaker body of the speaker either directly or through the heat transfer member. The heat is transferred to the outer cylinder of the silencer body directly or through the heat transfer member, and is radiated to the outside from the outer cylinder, which has the advantage of reliably preventing the permanent magnet from becoming hot. is there.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of an active silencer of the present invention.

FIG. 2 is a top view of FIG.

FIG. 3 is a sectional view taken along line III-III in FIG.

FIG. 4 is a sectional view showing an example of a conventional active silencer.

5 is a cross-sectional view showing the speaker of FIG.

[Explanation of symbols]

 41 speaker main body 61 silencer main body 62 outer cylinder 63 partition wall 65 silencer room 67 speaker room 69 exhaust pipe 85 heat transfer member

Claims (1)

[Scope of utility model registration request] 1. A silencer body (61) made of metal is attached to a partition wall (6).
Partitioned by 3), muffling room (65) and speaker room (6)
7), an exhaust pipe (69) is connected to the muffler chamber (65), and a speaker (75) is housed in the speaker chamber (67). An active silencer characterized in that the outer cylinder (62) of (61) is in contact with the speaker body (41) of the speaker (75) either directly or via a heat transfer member (85).