JP4214899B2 - Speaker - Google Patents

Description

  The present invention relates to a speaker provided with a detachable front grill.

  FIG. 7 is a diagram illustrating an example of a conventional speaker. As shown in FIG. 7, a diaphragm 3 is fixed to a baffle plate 2 on the front surface of the housing 1 in the speaker. A front grill 4 holding a protection net is attached to the baffle plate 2 in order to protect the diaphragm 3 from dust in the air. In order to attach the front grille 4, four hold pins 5 are erected on the baffle plate 2. FIG. 8 is a cross-sectional view showing the grill frame 4 a of the front grill 4 attached to the hold pin 5. As shown in FIG. 8, a hole is formed at a position corresponding to the hold pin 5 on the back surface of the grill frame 4a, and a rubber bush 6 is provided in the hole. The front grill 4 is fixed to the baffle plate 2 by inserting a hold pin 5 into the rubber bush 6.

  By the way, the speaker is exhibited not only in a state where the front grille is mounted but also in a state where the front grille is removed. For this reason, the aesthetic feeling given to the user with the front grill removed is important for the speaker. However, the speaker shown in FIG. 7 has a problem in the ability to cause this aesthetic feeling because the hold pin protrudes on the baffle plate with the front grill removed. Further, the speaker shown in FIG. 7 has a problem that the hold pin adversely affects the sound field.

Patent Document 1 discloses a technique for solving this problem. In the speaker disclosed in Patent Document 1, a hole is formed in the back surface (inner wall surface of the housing) of the baffle plate which is a part of the housing, and a permanent magnet is embedded therein, while the front decorative plate is provided. A magnetic material is affixed to the back surface of the plate, and the front decorative plate is fixed to the baffle plate by adsorbing the magnetic material to a permanent magnet. If the technique disclosed in Patent Document 1 is used, the front grille can be fixed to the front surface of the speaker housing without using a hold pin.
Japanese Utility Model Publication No. 60-14586

  However, when using the technique disclosed in Patent Document 1, in order to attach the front grille, a special process such as opening a hole or embedding a permanent magnet must be applied to the housing. There is a problem that it takes time and labor and increases the manufacturing cost.

  The present invention has been made in view of the circumstances described above. The front grill can be attached and detached, and a simple configuration that can be manufactured without applying special processing to the housing for attaching the front grill. An object of the present invention is to provide a speaker.

The present invention includes a casing having an opening on the front surface, a speaker unit having a diaphragm, and a magnetic body, and the diaphragm is exposed from the opening to surround the diaphragm in the speaker unit. A plurality of fasteners for fixing the portion to the peripheral portion of the opening in the housing, a protective net, a grille frame for holding the protective net, and a plurality of permanent magnets respectively fixed to the back surface of the grille frame And the plurality of permanent magnets in the front grille are opposed to the plurality of fasteners in a state where the protective net covers the diaphragm, and each fastener is attracted by a magnetic force. Thus, the speaker is characterized in that the front grill is fixed to the front surface of the casing.
In this invention, means for fixing the front grille to the front surface of the casing only by using a fastener provided to fix the speaker unit to the casing and providing a permanent magnet for attracting the speaker unit on the front grille side. Is configured. According to this invention, when the front grill is fixed to the front surface of the casing, no special processing is required for the casing.
In a preferred aspect, the speaker unit has an electromagnetic drive unit having a permanent magnet as means for driving the diaphragm, and the magnetic axes of the plurality of permanent magnets in the front grille are permanent magnets of the drive unit. Is parallel to the magnetic axis and facing in the opposite direction.
According to this aspect, the magnetic flux generated by the permanent magnet fixed to the front grille cancels out the leakage magnetic flux that passes through the outside of the casing among the magnetic flux generated by the permanent magnet of the drive unit. Therefore, leakage magnetic flux to the outside of the housing can be reduced, and adverse effects on electronic devices around the speaker can be reduced.

  FIG. 1 is a front view showing a configuration of a speaker according to an embodiment of the present invention, and FIG. 2 is a sectional view taken along line Ia-Ia ′ in FIG. FIG. 1 shows the speaker with the front grille removed. As shown in FIG. 1, a frame 21 of the speaker unit 20 is fixed to the front surface of the speaker housing 10. The frame 21 is a non-magnetic aluminum frame, and the diaphragm 22 held in the center of the frame 21 is exposed from the front surface of the housing 10.

  As shown in FIG. 2, the housing 10 is a hollow housing having an opening 11 on the front surface. In the speaker unit 20, the frame 21 is left outside the housing 10, and the other part is accommodated in the housing 10 through the opening 11. The frame 21 is fixed to a portion around the opening 11 in the housing 10 by four screws 23a, 23b, 23c, and 23d shown in FIG. These screws 23a, 23b, 23c, and 23d are iron screws that are ferromagnetic materials.

  Two terminals to which audio signals are input are provided on the rear surface of the housing 10. FIG. 2 shows one of these terminals 12 and two lead wires 13 and 14 for supplying an audio signal supplied via the two terminals to the speaker unit 20. The speaker unit 20 incorporates an electromagnetic drive unit having a permanent magnet. The drive unit vibrates the diaphragm 22 in accordance with the audio signal supplied via the lead wires 13 and 14. Note that 15 is a sound absorbing material for adjusting the acoustic characteristics of the speaker, and 16 is a leg that supports the housing 10.

  As shown in FIG. 2, a front grill 30 is held on the front surface of the housing 10. 3 is a front view of the front grill 30, FIG. 4 is a sectional view taken along line Ib-Ib ′ of FIG. 3, and FIG. 5 is a rear view of the front grill 30. As shown in these drawings, the front grill 30 has a grill frame 31, and a protective net 32 is stretched over a circular opening formed in the grill frame 31. In addition, permanent magnets 33 a, 33 b, 33 c, and 33 d are fixed to the four corners of the rear surface of the grill frame 31 with their magnetic poles protruding from the rear surface of the front grill 30. These four permanent magnets 33a, 33b, 33c, and 33d are screws 23a that fix the speaker unit 20 when the grill frame 31 is positioned so that the protective net 32 covers the front surface of the diaphragm 22. The heads 23b, 23c, and 23d face each other. In this state, the screws 23a, 23b, 23c, and 23d are attracted by the four permanent magnets 33a, 33b, 33c, and 33d, whereby the front grill 30 is fixed to the front surface of the housing 10.

  As described above, in the present embodiment, focusing on the fact that the fastener for fixing the speaker unit 20 to the housing 10 is an iron screw that is a ferromagnetic material, A means for fixing the front grill 30 to the housing 10 is configured by an extremely simple configuration in which a permanent magnet for attracting the screw is provided at an opposing position. Therefore, it is not necessary to apply special processing to the housing 10 when attaching the front grill 30.

  In the present embodiment, the frame 21 of the speaker unit 20 is made of aluminum which is a non-magnetic material, and screws 23a, 23b, 23c and 23d which are ferromagnetic materials are driven into the frame 21. Therefore, the user can easily guide the permanent magnets 33a, 33b, 33c, and 33d to the screws 23a, 23b, 23c, and 23d.

  FIG. 6 is a diagram showing a configuration of a speaker obtained by further improving the embodiment described above. Similar to the above-described embodiment, this speaker is also provided with four permanent magnets 33a, 33b, 33c, and 33d on the front grille. Fixed to. In FIG. 6, only the permanent magnets 33a and 33b among the four permanent magnets 33a, 33b, 33c and 33d are shown. In the configuration shown in FIG. 6, the magnetic axis of the permanent magnet 24 of the drive unit faces the front-rear direction of the housing 10, and the front side of the housing 10 is an N pole and the rear side is an S pole. On the other hand, the permanent magnets 33a, 33b, 33c, and 33d for fixing the front grill 30 to the front surface of the housing 10 have their respective magnetic axes parallel to the magnetic axis of the permanent magnet 24, but their polarities are permanent magnets. 24, each N pole is directed to the front surface of the housing 10. For this reason, the magnetic flux generated by the permanent magnets 33a, 33b, 33c, and 33d cancels out the leakage magnetic flux that passes through the outside of the housing 10 among the magnetic flux generated by the permanent magnet 24 of the drive unit, as shown in the figure.

  In general, it has been difficult to configure the speaker so that the magnetic flux generated by the drive unit does not leak to the outside of the housing as the size of the speaker decreases. However, according to the present embodiment, the front grille is fixed. This leakage magnetic flux can be reduced by using a permanent magnet. Therefore, it is possible to realize a speaker that is small in size and has a so-called antimagnetic effect with a simple configuration.

As mentioned above, although embodiment of this invention was described, various aspects other than the above can be considered for this invention.
For example, in each of the above embodiments, the frame 21 is fixed to the housing 10 with the screws 23 a to 23 d in a state where the frame 21 is disposed outside the housing 10. However, instead of doing so, in a state in which the frame 21 is disposed inside the housing 10, screws 23 a to 23 d are passed through the housing 10 and the frame 21 from the outside of the housing 10, so that the housing 10 and the frame 21 are inserted. And may be fixed. Also in this configuration, the diaphragm 22 is exposed from the opening 11, and the heads of the screws 23a to 23d are exposed from the surface of the housing 10, so that the permanent magnets on the front grille side are connected to the screws 23a to 23d. And the front grille can be fixed to the front surface of the housing 10.
The number of screws may be any number, and the necessary number of permanent magnets on the front grille side may be provided.
The number of screws for fixing the speaker unit to the housing may not be the same as the number of permanent magnets on the front grille side. The number of screws required for fixing the speaker unit to the housing is sufficient, and the number of permanent magnets required for obtaining the desired magnetic-shielding effect may be arranged at an appropriate position on the front grille. For example, six screws are used to fix the speaker unit to the housing, and permanent magnets are provided only at four of the six locations facing the screws on the back of the front grill in order to obtain the necessary magnetic shielding effect. There may be a mode of arranging. Conversely, for example, four screws are used to fix the speaker unit to the housing, and permanent magnets are arranged at four locations facing the screws on the rear surface of the front grill, and further necessary magnetic shielding effects are obtained. Therefore, there may be an aspect in which an additional permanent magnet is disposed.

It is a front view which shows the structure of the speaker which is one Embodiment of this invention. FIG. 2 is a sectional view taken along line Ia-Ia ′ of FIG. 1. It is a front view which shows the structure of the front grille in the same embodiment. FIG. 4 is a sectional view taken along line Ib-Ib ′ in FIG. 3. It is a rear view of the front grill. It is a figure which shows the structure of the speaker which is other embodiment of this invention. It is a perspective view which shows the structure of the conventional speaker. It is sectional drawing which shows the attachment structure of the front grille in the same speaker.

Explanation of symbols

10 ... Case, 20 ... Speaker unit, 21 ... Frame, 23a, 23b, 23c, 23d ... Screw, 31 ... Grill frame, 32 ... Protective net, 33a, 33b, 33c, 33d ... Permanent magnet.

Claims (2)

A housing having an opening on the front surface;
A speaker unit having a diaphragm;
A plurality of fasteners each configured of a magnetic body, exposing the diaphragm from the opening, and fixing a portion around the diaphragm in the speaker unit to a portion around the opening in the housing;
A protective net, a grille frame holding the protective net, and a front grille having a plurality of permanent magnets each fixed to the back surface of the grille frame,
The plurality of permanent magnets in the front grill face each of the plurality of fasteners in a state where the protective net covers the diaphragm, and attract the fasteners by magnetic force to thereby attach the front grill to the casing. A speaker characterized by being fixed to the front of the speaker.   The speaker unit has an electromagnetic drive unit having a permanent magnet as means for driving the diaphragm, and the magnetic axes of the plurality of permanent magnets in the front grill are the magnetic axes of the permanent magnets of the drive unit. The speaker according to claim 1, wherein the speakers are parallel and face in opposite directions.

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