JP3829712B2 - Manufacturing method of electric horn - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing an electric horn (alarm) that is used in a vehicle or the like and vibrates a diaphragm with an electromagnet, and particularly relates to an adjustment of an off-gap that determines an energization period of an electromagnet coil.
[0002]
[Prior art]
In a conventional electric horn, a pressing part of a movable contact support plate made of a metal spring material is provided on a movable iron core, and when the movable iron core is attracted to the fixed iron core by the electromagnetic force of the electromagnet, it can be moved by the pressing part of the movable iron core. The movable contact is separated from the fixed contact by pressing the contact support plate.
[0003]
By the way, in order to satisfactorily demonstrate the performance of the electric horn, it is necessary to appropriately set an off-gap described below and to set the current flowing in the electromagnet within an appropriate range. Here, the off-gap is the distance between the pressing portion of the movable iron core and the movable contact support plate when the electromagnet is not energized, and more specifically, the pressing portion of the movable iron core when the electromagnet is not energized The distance from the movable contact support plate when the movable contact support plate is pressed by the pressing portion of the movable iron core when the electromagnet is energized and the movable contact is separated from the fixed contact.
[0004]
When this off-gap is small, the movable contact is quickly separated from the fixed contact, so the energization time of the electromagnet is shortened, and the current value (effective current value) flowing through the coil of the electromagnet is small. When this current value decreases, the time for generating the attractive force of the movable iron core decreases, the amplitude of the diaphragm integrated with the movable iron core decreases, and the sound pressure (volume) of the horn sound is reduced.
[0005]
Conversely, if the off-gap is large, the amount of pressing of the movable contact support plate by the pressing part of the movable core decreases, so the distance between the two contacts when the movable contact is separated from the fixed contact is reduced, and the coil current The blocking effect is worsened. As a result, the balance between the attracting action of the movable iron core and the restoring action of the movable iron core due to intermittent coil current is lost, the amplitude of the diaphragm becomes unstable, and the timbre deteriorates.
[0006]
In order to avoid the above problems, it is necessary to strictly manage the off-gap within an appropriate range. Therefore, conventionally, an adjustment screw is provided on the bottom surface portion of the horn housing, and the position of the fixed contact support plate is moved up and down depending on the screwing position of the adjustment screw, thereby adjusting the off gap to an appropriate range.
[0007]
However, such an off-gap adjustment method requires a dedicated adjustment member (adjustment screw) and increases the number of parts. Moreover, since it is necessary to process the screwing part of an adjustment screw also in the horn housing side, a cost increase is caused. Furthermore, since the adjustment screw is required to be screwed in, the number of adjustment work steps increases.
[0008]
Therefore, in Japanese Utility Model Laid-Open No. 2-85499, the off-gap is adjusted by rotating a vibrating body composed of a movable iron core, a diaphragm and a spiral body. Is wound on the outer peripheral end of the diaphragm over the entire circumference, and the outer peripheral end of the diaphragm is fixed to the outer peripheral end of the horn housing 10.
[0009]
[Problems to be solved by the invention]
According to this adjustment method, adjustment screws, etc. can be eliminated, but on the other hand, after the adjustment work for the off-gap is completed, the outer peripheral end of the horn housing is bent to the outer peripheral end of the diaphragm, and the diaphragm is fixed to the horn housing. Therefore, the bending load causes deformation of the horn housing. When this deformation occurs, the axial position of the movable iron core changes, which causes a problem that the folding angle and the adjusted off-gap deviate from the appropriate range.
[0010]
In view of the above, the present invention can adjust the off-gap by a simple method that does not require the screwing operation of the adjusting screw and the like, and a method for manufacturing an electric horn that can reliably maintain the adjusted proper off-gap. The purpose is to provide.
[0011]
[Means for Solving the Problems]
In order to achieve the above object, according to the first aspect of the present invention, a horn housing (10), a diaphragm (11) having an outer peripheral end fixed to the horn housing (10), and the center of the diaphragm (11) A movable iron core (15) fixed to the part, a fixed iron core (21) disposed opposite to the movable iron core (15), a coil (14) for sucking the movable iron core (15) into the fixed iron core (21), and a coil The fixed contact (18a) provided in the energizing circuit (14), the fixed contact support plate (18) for supporting the fixed contact (18a), and a normally closed type that normally closes to the fixed contact (18a). A movable contact (17a), a movable contact support plate (17) that supports the movable contact (17a), and an inclined surface (15d) that is provided on the movable iron core (15) and presses the movable contact support plate (17). A pressing portion (15c),
When the movable iron core (15) is attracted to the fixed iron core (21) by the electromagnetic force of the coil (14), the movable contact support plate (17) is pressed by the inclined surface (15d), thereby moving the movable contact (17a). A method of manufacturing an electric horn that is separated from a fixed contact (18a),
A diaphragm fixing step of fixing the outer peripheral end of the diaphragm (11) to the horn housing (10), and an inclined surface (15d) and a movable contact support plate when the coil (14) is not energized after the diaphragm fixing step. An adjustment step of adjusting the off-gap, which is a distance from (17), according to the rotational position of the movable iron core (15), and a movable iron core that fixes the movable iron core (15) to the center portion of the diaphragm (11) after the adjustment step. And a fixing step.
[0012]
According to this, the movable contact support plate facing part of the inclined surface (15d) changes depending on the rotational position of the movable iron core (15), and the off-gap can be adjusted, so that it is a simple method that does not require the screwing operation of the adjusting screw. Off-gap can be adjusted. Therefore, the number of parts can be reduced by eliminating the adjustment screw, and the screwing operation of the adjustment screw is not necessary, so that the cost of the electric horn can be reduced.
[0013]
Moreover, since the off-gap is adjusted after the outer peripheral end of the diaphragm (11) is fixed to the horn housing (10), the deformation of the horn housing (10) that occurs in the fixing process of the diaphragm (11) is turned off. Does not affect gap adjustment. As a result, an appropriate adjusted off-gap can be reliably maintained at the time of product shipment.
[0014]
According to a second aspect of the present invention, in the first aspect, the movable iron core (15) is temporarily fixed to the central portion of the diaphragm (11) in advance, and then the diaphragm fixing step is performed. A fixing step is performed, and the movable iron core (15) is caulked and fixed to the center of the diaphragm (11).
[0015]
As described above, the movable iron core (15) and the diaphragm (11) can be combined into one assembly by temporarily fixing the movable iron core (15) to the central portion of the diaphragm (11) in advance. Therefore, the diaphragm (11) fixing step and the off-gap adjusting step performed after the temporary fixing do not become complicated.
[0016]
According to a third aspect of the present invention, in the second aspect, the center hole (11a) of the diaphragm (11) is fitted into the small diameter part (15b) of the movable iron core (15), and the diaphragm (11) is mounted on the diaphragm (11). The cylindrical portion (16a) at the center of the resonance plate (16) laminated on the core is pressed into the small diameter portion (15b) of the movable core (15), thereby moving the movable core (15) to the center of the diaphragm (11). In the movable iron core fixing step, the small diameter portion (15b) is caulked, and the diaphragm is formed between the caulking deformed portion (15g) of the small diameter portion (15b) and the stepped surface (15f) of the small diameter portion (15b). The peripheral portion of the central hole (11a) of (11) and the cylindrical portion (16a) of the resonance plate (16) are sandwiched.
[0017]
Thereby, temporary fixation of the movable iron core (15) can be performed easily and reliably using the cylindrical part (16a) formed in the center part of the resonance plate (16). After adjusting the off-gap, the movable iron core (15) is firmly attached to the central portion of the diaphragm (11) through the cylindrical portion (16a) of the resonance plate (16) by caulking the small diameter portion (15b). Can be fixed.
[0018]
According to a fourth aspect of the present invention, in the third aspect, a non-circular tool locking hole (15e) is provided in the small diameter portion (15b) of the movable iron core (15), and the tool locking hole (15e) is provided in the adjusting step. The movable iron core (15) is rotated by engaging the tool with the tool.
[0019]
Thereby, the rotation operation of the movable iron core (15) can be easily performed in the off-gap adjustment step.
[0020]
In addition, the code | symbol in the bracket | parenthesis of each said means shows the correspondence with the specific means as described in embodiment mentioned later.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
(First embodiment)
The present embodiment relates to a method for manufacturing an electric horn for a vehicle, FIG. 1 is a sectional view of the overall structure of the electric horn for a vehicle manufactured according to the present embodiment, and FIG. 2 is an enlarged view of the main part of FIG. It is sectional drawing. 3A and 3B show examples of the shape of the inclined surface provided on the movable iron core.
[0022]
Before describing the manufacturing method of the present embodiment, the overall structure of the electric horn will be described first. A horn housing 10 accommodates an electromagnet 12 that vibrates the diaphragm 11 and the like. In order to form part of the magnetic circuit of the electromagnet 12, the horn housing 10 and the diaphragm 11 are formed by pressing an iron-based magnetic material plate into a concave shape.
[0023]
The electromagnet 12 includes a coil 14 wound around a resin bobbin 13, and a cylindrical part 15 a below the movable iron core 15 formed in a cylindrical shape is disposed in the central hole part of the bobbin 13. Has been. A center hole portion 11a of the diaphragm 11 and a cylindrical portion (burring processing portion) 16a at the center portion of the resonance plate 16 are fitted and fixed to the small diameter portion 15b of the upper portion of the movable core 15. The outer peripheral end portion 11b of the diaphragm 11 is fastened and fixed to the flange portion 10a at the outer peripheral end portion of the horn housing 10 over the entire periphery.
[0024]
The concave intermediate flat portion 10b of the horn housing 10 includes a protruding portion 13b protruding radially outward from the upper flange portion 13a of the bobbin 13, a movable contact support plate 17 made of a metal spring material, a fixed contact support plate 18, Insulating members 19 interposed between the two contact support plates 17 and 18 are laminated, and these members are caulked and fixed on the intermediate flat portion 10b by metal rivets 20.
[0025]
Here, the insulating member 19 is formed of a resin plate material, and is laminated on the upper surface of the movable contact support plate 17 over substantially the entire length of the movable contact support plate 17. The fixed contact support plate 18 is formed of a ferrous conductor metal that is relatively easily deformed, for example, a cold rolled steel plate (low carbon steel) plate material.
[0026]
A movable contact 17a is fixed to the movable contact support plate 17, and a fixed contact 18a is fixed to the fixed contact support plate 18, respectively. The movable contact 17a is a normally-closed contact that is crimped to the fixed contact 18a by a spring force generated by elastic deformation of the movable contact support plate 17 at normal times (when the coil 14 is not energized).
[0027]
A ring-shaped flange portion 15c projecting radially outward is integrally formed on the outer peripheral surface of the intermediate portion in the axial direction of the movable iron core 15 by cold forging or the like. The pressing part which presses the site | part near the horn center part among the movable contact support plates 17 is comprised.
[0028]
Here, the lower surface of the flange portion 15c forms an inclined surface 15d that is inclined with respect to the axial direction of the movable iron core 15. The inclined surface 15d is specifically a spiral shape shown in FIG. Any of the taper shapes shown in FIG. The spiral shape of FIG. 3A is formed on the entire circumference of the 360 ° rotation range where the inclined surface 15d starts at the start point a and ends at the end point b. On the other hand, in the tapered shape of FIG. 3B, the inclined surface 15d is formed so as to go in one direction from the start point c at the 180 ° symmetrical position to the end point d.
[0029]
Further, a tool locking hole 15e is formed in the small diameter portion 15b of the upper portion of the movable iron core 15. As the tool locking hole 15e, for example, a hexagonal cross section is suitable, but any other noncircular hole shape such as a polygonal shape, a cross shape, or a minus shape may be used.
[0030]
A fixed iron core 21 is disposed in the center hole of the bobbin 13 of the electromagnet 12 so as to face the lower end surface of the movable iron core 15 with a predetermined suction gap. The fixed iron core 21 is fixed to the center portion of the bottom surface portion 10c of the horn housing 10 by means such as caulking. The fixed iron core 21 is integrally formed with a male screw portion 21a that protrudes to the outside of the bottom surface portion 10c of the horn housing 10, and a mounting stay 22 to the vehicle body is fastened and fixed to the male screw portion 21a by a nut 23.
[0031]
One end portion of the coil 14 is electrically connected to a terminal piece of a connector portion (not shown) disposed outside the horn housing 10, and the other end portion of the coil 14 is electrically connected to the movable contact support plate 17. . The fixed contact support plate 18 is electrically connected to the horn housing 10 via a metal rivet 20, and is further grounded to the vehicle body of the vehicle via a fixed iron core 21 and a mounting stay 22 fixed to the horn housing 10. It has become.
[0032]
Next, the manufacturing method of the electric horn according to the present embodiment will be described. In the manufacturing method of this embodiment, the process of incorporating the coil 14 wound around the resin bobbin 13, the movable contact support plate 17, the fixed contact support plate 18, the fixed iron core 21 and the like into the horn housing 10 is the same as the conventional method. Therefore, the description of these steps is omitted, and the assembly process of the diaphragm 11 portion including the movable iron core 15 and the resonance plate 16 will be described in detail.
[0033]
In the assembling step of the diaphragm 11 portion, first, the small diameter portion 15 b at the top of the movable iron core 15 is temporarily fixed to the diaphragm 11. Specifically, the center hole portion 11a of the diaphragm 11 is fitted into the small-diameter portion 15b at the top of the movable iron core 15, and the stepped surface 15f of the root portion of the small-diameter portion 15b of the movable iron core 15 is fitted to the center portion of the diaphragm 11. Abut. Next, the cylindrical portion 16 a at the center of the resonance plate 16 is press-fitted and fixed to the small diameter portion 15 b of the movable iron core 15.
[0034]
At this time, the resonance plate 16 is press-fitted until the peripheral edge of the cylindrical portion 16 a of the resonance plate 16 abuts against the center portion of the vibration plate 11, and therefore, between the resonance plate 16 and the stepped surface 15 f of the movable iron core 15. The diaphragm 11 is sandwiched. Thereby, the movable iron core 15 can be temporarily fixed to the diaphragm 11.
[0035]
Next, the diaphragm 11 is incorporated into the horn housing 10, and the outer peripheral end 11 b of the diaphragm 11 is wound on the flange 10 a at the outer peripheral end of the horn housing 10, whereby the outer peripheral end 11 b of the diaphragm 11 is horned. Fix to the housing 10.
[0036]
Next, an adjustment process of the off gap G is performed. Here, the off-gap G can be defined as shown in FIG. That is, FIG. 2 shows the position of the movable core 15 when the coil 14 is not energized. When the coil 14 is not energized, the lower inclined surface 15d of the flange portion 15c that forms the pressing portion of the movable core 15 and the movable contact support are shown. The distance from the insulating member 19 located on the plate 17 is the off gap G.
[0037]
In FIG. 2, the movable contact support plate 17, the fixed contact support plate 18, the insulating member 19 and the like are fixed to the horn housing 10 before adjusting the off-gap.
[0038]
In the adjustment process of the off-gap G, an appropriate tool (not shown) is inserted into the tool locking hole 15e provided on the end surface of the small diameter portion 15b of the movable iron core 15, and the movable iron core 15 is rotated by operating this tool. Rotate. Here, the lower surface of the flange portion 15c of the movable iron core 15 is formed with an inclined surface 15d having a spiral shape shown in FIG. 3A or a tapered shape shown in FIG. 3B, so that when the movable iron core 15 rotates, The part of the inclined surface 15d facing the insulating member 19 on the movable contact support plate 17 changes. Thereby, the distance between the inclined surface 15d and the insulating member 19 changes, and the off-gap G can be adjusted to a value within an appropriate range.
[0039]
Next, the movable iron core 15 is firmly fixed to the center portion of the diaphragm 11. Specifically, the upper end portion of the small diameter portion 15b of the movable iron core 15 is caulked so as to expand to the outer peripheral side as shown in FIG. 1, thereby forming the caulking deformation portion 15g. Accordingly, the cylindrical portion 16a of the resonance plate 16 and the peripheral edge portion of the center hole portion 11a of the diaphragm 11 can be firmly sandwiched between the caulking deformed portion 15g and the stepped surface 15f, and the movable iron core 15 can be attached to the diaphragm. 11 can be firmly fixed to the central portion.
[0040]
By the way, according to the above manufacturing method, since the off-gap G is adjusted after the outer peripheral end portion 11b of the diaphragm 11 is tightened and fixed to the horn housing 10, when the outer peripheral end portion 10a of the horn housing 10 is tightened. Even if the horn housing 10 is deformed, the deformation does not affect the adjustment of the off-gap G.
[0041]
Further, the caulking step of the small diameter portion 15b of the movable iron core 15 performed after the adjustment of the off gap G is a caulking deformation process for expanding the small diameter portion 15b portion to the outer peripheral side, and the deforming portion 15g of the caulking step is the movable iron core 15. However, the adjusted off-gap G does not change because it does not affect the axial position of the movable iron core 15.
[0042]
Next, the operation of the electric horn according to the present embodiment will be described. When a horn switch (not shown) is turned on, an electric current from a vehicle-mounted power source is supplied from an electromagnetic coil 14 → movable contact support plate 17 → movable contact from a connector portion (not shown). It flows in the route of 17a → fixed contact 18a → fixed contact support plate 18 → rivet 20 → horn housing 10 → fixed iron core 21 → mounting stay 22 → vehicle body (grounding).
[0043]
Thus, the electromagnetic force of the electromagnetic coil 14 acts on the suction gap between the movable iron core 15 and the fixed iron core 21, and the movable iron core 15 is attracted to the fixed iron core 21. Due to the displacement of the movable iron core 15, the inclined surface 15d of the flange portion 15c of the movable iron core 15 presses the insulating member 19 on the movable contact support plate 17, and the movable contact 17a is separated from the fixed contact 18a. As a result, the energization of the electromagnetic coil 14 is interrupted and the electromagnetic force is lost, so that the movable iron core 15 returns to the original position by the elastic reaction force of the diaphragm 11, and thereby the movable contact 17a and the fixed contact 18a The closed state is restored. In this way, when the energization of the electromagnetic coil 14 is interrupted, the vibration plate 11 and the resonance plate 16 vibrate at a high frequency and emit a warning sound.
(Other embodiments)
In the above-described embodiment, the cylindrical portion 16a is formed in the center portion of the resonance plate 16, and the cylindrical portion 16a is press-fitted into the small diameter portion 15b of the movable iron core 15 with the diaphragm 11 interposed therebetween. The movable iron core 15 is temporarily fixed to the center portion of the diaphragm 11 in advance, but the cylindrical portion 16a at the center portion of the resonance plate 16 is eliminated, and only the center hole portion is provided in the plate material of the resonance plate 16, and this resonance The movable iron core 15 may be temporarily fixed to the central portion of the diaphragm 11 by press-fitting the central hole portion of the plate 16 into the small diameter portion 15 b of the movable iron core 15.
[0044]
Further, in the above-described embodiment, the insulating member 19 on the movable contact support plate 17 is extended to a portion facing the inclined surface 15d of the flange portion 15c of the movable iron core 15, and the movable contact support plate 17 is formed on the movable contact support plate 17 by the inclined surface 15d. Although the insulating member 19 is pressed, an insulating member is provided below the inclined surface 15d, and the metal surface of the movable contact support plate 17 is directly pressed via the insulating member by the inclined surface 15d. Also good.
[Brief description of the drawings]
FIG. 1 is a sectional view of an entire electric horn according to an embodiment of the present invention.
FIG. 2 is an enlarged cross-sectional view of a main part of FIG.
3 is an explanatory view of an inclined surface of the movable iron core shown in FIGS. 1 and 2. FIG.
[Explanation of symbols]
10 ... Horn housing, 11 ... Diaphragm, 12 ... Electromagnet, 14 ... Coil,
15 ... movable iron core, 15c ... flange part (pressing part), 15d ... inclined surface,
15e ... Tool locking hole, 17 ... Movable contact support plate, 17a ... Movable contact,
18 ... fixed contact support plate, 18a ... fixed contact, 21 ... fixed iron core.

Claims (4)

A horn housing (10);
A diaphragm (11) having an outer peripheral end fixed to the horn housing (10);
A movable iron core (15) fixed to the center of the diaphragm (11);
A fixed iron core (21) disposed opposite to the movable iron core (15);
A coil (14) for attracting the movable iron core (15) to the fixed iron core (21);
A fixed contact (18a) provided in the energization circuit of the coil (14);
A fixed contact support plate (18) for supporting the fixed contact (18a);
A normally closed movable contact (17a) that normally closes to the fixed contact (18a);
A movable contact support plate (17) for supporting the movable contact (17a);
A pressing portion (15c) provided on the movable iron core (15) and having an inclined surface (15d) for pressing the movable contact support plate (17);
When the movable iron core (15) is attracted to the fixed iron core (21) by the electromagnetic force of the coil (14), the movable contact support plate (17) is pressed by the inclined surface (15d), A method for manufacturing an electric horn, wherein a movable contact (17a) is separated from the fixed contact (18a),
A diaphragm fixing step of fixing an outer peripheral end of the diaphragm (11) to the horn housing (10);
After the diaphragm fixing step, an off gap, which is a distance between the inclined surface (15d) and the movable contact support plate (17) when the coil (14) is not energized, is rotated by the movable iron core (15). An adjustment process to adjust according to the position;
A method of manufacturing an electric horn, comprising: a movable iron core fixing step of fixing the movable iron core (15) to a central portion of the diaphragm (11) after the adjusting step. The movable iron core (15) is temporarily fixed to the central portion of the diaphragm (11) in advance, and then the diaphragm fixing step is performed.
After said adjusting step, the electrical horn according to claim 1, characterized in that the caulked to the movable iron core to implement the movable iron core fixing step (15) in the center of the diaphragm (11) Production method. The center hole (11a) of the diaphragm (11) is fitted into the small diameter part (15b) of the movable iron core (15) and the center of the resonance plate (16) stacked on the diaphragm (11). The cylindrical portion (16a) of the portion is press-fitted into the small diameter portion (15b) of the movable core (15) to temporarily fix the movable core (15) to the center portion of the diaphragm (11),
In the movable core fixing step, the small diameter portion (15b) is caulked, and the diaphragm is between the caulking deformed portion (15g) of the small diameter portion (15b) and the stepped surface (15f) of the small diameter portion (15b). The method for manufacturing an electric horn according to claim 2, wherein the peripheral portion of the central hole portion (11a) of (11) and the cylindrical portion (16a) of the resonance plate (16) are sandwiched. A non-circular tool locking hole (15e) is provided in the small diameter portion (15b) of the movable iron core (15),
The method of manufacturing an electric horn according to claim 3, wherein a tool is locked in the tool locking hole (15e) and the movable iron core (15) is rotated in the adjusting step.

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