JPH0662691U - Speaker - Google Patents

Abstract

(57) [Summary] [Object] The present invention relates to a speaker, and particularly to a speaker having high heat resistance that can be used in a high temperature atmosphere, and an object thereof is to reliably prevent a permanent magnet from reaching a high temperature. To do. In a speaker having a permanent magnet 73 for generating a magnetic field, thermoelectric heat pumps 75, 77 for cooling the permanent magnet 73 by a Peltier effect cooling function are arranged outside the permanent magnet 73. To do.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a speaker, and more particularly to a speaker having high heat resistance that can be used in a high temperature atmosphere.

[0002]

[Prior art]

 Conventionally, as an active silencer that positively silences the noise of exhaust gas by a secondary sound source, for example, the one disclosed in Japanese Patent Publication No. 58-501292 is known.

FIG. 2 and FIG. 3 show an active silencer of this type. In the drawings, reference numeral 11 indicates a silencer body having a rectangular cross section. 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. 4 shows the details of the above-mentioned speaker 25. 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 located near the speaker 25 reaches the speaker 25 in a relatively short distance, so that the speaker 25 is greatly affected. There is a problem that a heat load is applied, and in particular, the function of the permanent magnet 53 may deteriorate.

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 the above conventional problems, and an object of the present invention is to provide a speaker capable of reliably preventing the permanent magnet from reaching a high temperature.

[0014]

[Means for Solving the Problems]

 The speaker of the present invention is a speaker having a permanent magnet for generating a magnetic field, in which a thermoelectric heat pump for cooling the permanent magnet by a Peltier effect cooling function is arranged outside the permanent magnet. Is.

[0015]

[Action]

 In the speaker of the present invention, by energizing the thermoelectric heat pump, the temperature of the permanent magnet of the thermoelectric heat pump becomes lower than the ambient temperature due to the Peltier effect, which cools the permanent magnet.

[0016]

【Example】

 The present invention will now be described in detail with reference to an embodiment shown in the drawings. FIG. 1 shows an embodiment of a speaker of the present invention. In the figure, reference numeral 61 denotes a speaker body composed of a frame portion 61a and a bottom portion 61b.

A center pole 63 is arranged at the center of the speaker body 61, and one end thereof is fixed to the bottom portion 61 b of the speaker body 61. A voice coil 65 is arranged outside the center pole 63, and one side of a diaphragm 67 made of, for example, aluminum is connected to the voice coil 65.

A cap 69 is arranged in the center of the vibration plate 67, and the other side of the vibration plate 67 is connected to the tip of the frame portion 61 a via an edge 71. An annular permanent magnet 73 is arranged outside the center pole 63 at a predetermined distance from the center pole 63.

In this embodiment, however, an annular plate-shaped thermoelectric heat pump 75 is arranged inside the bottom portion 61b of the speaker body 61, and the side surface of the permanent magnet 73 contacts the thermoelectric heat pump 75. Has been done.

A cylindrical thermoelectric heat pump 77 is arranged inside the frame portion 61 a, and the outer peripheral surface of the permanent magnet 73 is in contact with the thermoelectric heat pump 77. A power supply circuit 81 having a power supply 79 is connected to the thermoelectric heat pumps 75 and 77, and a control unit 83 and a relay 85 are arranged in the power supply circuit 81.

A thermocouple 87 for measuring the temperature of the permanent magnet 73 is connected to the control unit 83. In the above-mentioned speaker, when the temperature of the permanent magnet 73 measured by the thermocouple 87 exceeds a predetermined temperature, the control unit 83 turns on the relay 85, and the power source 79 turns the thermoelectric heat pumps 75 and 77. When electricity is supplied, the Peltier effect causes the temperature of the thermoelectric heat pumps 75 and 77 on the permanent magnet 73 side to become lower than the ambient temperature, and the permanent magnet 73 is cooled.

When the temperature of the permanent magnet 73 decreases due to cooling and the temperature of the permanent magnet 73 becomes lower than a predetermined temperature, the relay 85 is turned off by the control unit 83, and the heat from the power source 79 is generated. The supply of electricity to the electric heat pumps 75 and 77 is stopped.

In the above-described speaker, however, the thermoelectric heat pumps 75 and 77 for cooling the permanent magnet 73 by the cooling function by the Peltier effect are arranged outside the permanent magnet 73. By energizing, the permanent magnet 73 side of the thermoelectric heat pumps 75 and 77 becomes lower than the ambient temperature due to the Peltier effect, and the permanent magnet 73 is cooled by this, so that it is ensured that the permanent magnet 73 becomes high in temperature. Can be prevented.

Therefore, even if the ambient temperature rises, the permanent magnet 73 does not lose its function as a magnet, and it can be used as a speaker for an active silencer used in the exhaust system of an internal combustion engine. Will be possible.

Further, particularly when applied to a speaker of an active silencer for an exhaust system of an automobile, this active silencer can be directly installed in an exhaust pipe, so that a trunk room or the like can be installed conventionally. It is not necessary to install in a limited number of places, there is no restriction on the place of installation, and productivity can be improved.

Further, since the speaker can be brought close to the exhaust pipe, it is possible to reduce the size of the active silencer, and even if the installation location is limited due to the unique structure of the automobile, the installation location is limited. It is possible to increase the degree of freedom in design.

Furthermore, since the shape of the active silencer is small, the active silencer is light in weight and the fuel consumption of the automobile can be improved. In addition, in the above-described embodiments, an example in which the present invention is applied to a cone type speaker has been described, but the present invention is not limited to such an embodiment, and a speaker using a permanent magnet may be used. Of course, this is applicable.

[0028]

[Effect of device]

 As described above, in the speaker of the present invention, the thermoelectric heat pump that cools the permanent magnet by the cooling function by the Peltier effect is arranged outside the permanent magnet. On the permanent magnet side, the temperature becomes lower than the ambient temperature due to the Peltier effect, and the permanent magnet is cooled by this, so that there is an advantage that it is possible to reliably prevent the permanent magnet from becoming high temperature.

[Brief description of drawings]

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

FIG. 2 is a sectional view showing an example of an active silencer.

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

FIG. 4 is a cross-sectional view showing a conventional speaker.

[Explanation of symbols]

 73 Permanent magnet 75,77 Thermoelectric heat pump

Claims (1)

[Scope of utility model registration request] 1. A permanent magnet (7) for generating a magnetic field.
3) In a speaker comprising: the permanent magnet (73)
A thermoelectric heat pump (75, 7) for cooling the permanent magnet (73) by a Peltier effect cooling function on the outside of the
A speaker characterized in that 7) is arranged.