阅读说明：本技术 车辆用报警器 (Alarm for vehicle ) 是由 铃木真悟 前桥祐哉 渡边干夫 泉勇希 于 2019-07-04 设计创作，主要内容包括：车辆用报警器(1)包括：可动铁芯(4),其通过磁吸引力而朝向固定铁芯(22)沿轴向位移；以及共鸣板(9),其与可动铁芯结合,从而使在可动铁芯与固定铁芯碰撞时产生的声音扩大。车辆用报警器还包括表面硬化层(4h、22h),该表面硬化层(4h、22h)形成在固定铁芯和可动铁芯各自的整个表面上,并且硬度比母材硬度更硬。固定铁芯和可动铁芯中的至少一个在固定铁芯与可动铁芯的碰撞部分(4a、22a)处,设置有弯曲凸面。(The vehicle alarm (1) comprises: a movable iron core (4) which is displaced in the axial direction toward the fixed iron core (22) by a magnetic attractive force; and a soundboard (9) coupled to the movable core so as to amplify sound generated when the movable core collides with the fixed core. The alarm for a vehicle further includes surface hardening layers (4h, 22h) that are formed on the entire surfaces of the fixed iron core and the movable iron core, respectively, and that have a hardness harder than the hardness of the base material. At least one of the fixed iron core and the movable iron core is provided with a curved convex surface at a collision portion (4a, 22a) of the fixed iron core and the movable iron core.)

1. An alarm for a vehicle, comprising:

a housing (11) having an opening (112 a);

a coil (20) which is housed in the case and generates a magnetic force when energized;

a fixed core (21; 122; 222) received in the housing;

a vibration plate (3) provided so as to cover the opening;

a movable iron core (4; 104) coupled to the diaphragm and axially displaced toward the fixed iron core by a magnetic attraction force generated by energizing the coil;

a soundboard (9) coupled to the movable core to amplify sound generated when the movable core collides with the fixed core; and

surface hardening layers (4h, 22h) formed on the entire surfaces of the fixed iron core and the movable iron core, respectively, and having a hardness harder than that of the base material,

at least one of the fixed iron core and the movable iron core is provided with a curved convex surface at a collision portion (4a, 22a) of the fixed iron core and the movable iron core.

2. The alarm for a vehicle according to claim 1, wherein the movable iron core is provided with the curved convex surface that protrudes toward the fixed iron core side.

3. The alarm for a vehicle according to claim 2, wherein the fixed iron core is provided with a flat surface orthogonal to the axial direction at a collision portion with the curved convex surface of the movable iron core.

4. The alarm for a vehicle according to claim 1, wherein the fixed core is provided with the curved convex surface that protrudes toward the movable core side.

5. The alarm for a vehicle according to claim 4, wherein the movable iron core is provided with a flat surface orthogonal to the axial direction at a collision portion with the fixed iron core.

6. The alarm for a vehicle according to claim 1, wherein the fixed iron core is provided with the curved convex surface at a collision portion with the movable iron core, and the movable iron core is provided with the curved convex surface at a collision portion with the fixed iron core.

7. The alarm for a vehicle according to any one of claims 1 to 6, wherein the surface hardened layer is a plated layer formed by electroless nickel plating containing nickel as a main component.

8. The alarm for a vehicle according to any one of claims 1 to 6, wherein the surface hardened layer is a plated layer formed by electroplating nickel having nickel as a main component.

9. The alarm for a vehicle according to any one of claims 1 to 6, wherein the surface hardened layer is a plated layer formed by hard chromium plating containing chromium as a main component.

10. The alarm for a vehicle according to any one of claims 1 to 6, wherein the surface hardening layer is a thin film formed by diamond-like carbon coating, and is an amorphous carbon hard film containing carbon and hydrogen.

11. The alarm for a vehicle according to any one of claims 1 to 6, wherein the surface hardened layer is a layer formed by coating molybdenum as a main component.

12. The alarm for a vehicle according to any one of claims 1 to 11, wherein the surface hardened layer has a hardness of 400 vickers or more.

13. The alarm for a vehicle according to any one of claims 1 to 12,

the stationary core has a contact surface (222c) that comes into contact with a pillar (5) for mounting to a vehicle-side member in a state of being fixed to the pillar;

a friction force increasing portion (222d) is provided on the surface hardening layer of the contact surface, the friction force increasing portion being a plurality of concave and convex portions each formed within a predetermined range.

14. The alarm device for a vehicle according to claim 13, wherein the plurality of concave-convex portions are arranged at intervals in a circumferential direction on the contact surface that is an annular surface, and are provided radially and annularly as a whole.

Technical Field

The present disclosure relates to a vehicle alarm device that generates an alarm sound.

Background

Patent document 1 discloses a vehicle alarm device. In the vehicle alarm, the movable core is attracted to the fixed core side by the magnetic attraction force and the vibrating plate is depressed in a state where the contact portions are closed, and a vibration sound generated when the movable core collides with the fixed core is transmitted to the resonating plate, and the vibration sound is resonated and amplified by the resonating plate to generate a sound. When the movable core is attracted to the fixed core while the horn switch is on, the contact portion is opened, the current is cut off, and the diaphragm returns.

Documents of the prior art

Patent document

Patent document 1: japanese unexamined patent publication No. 2003-189386

Disclosure of Invention

In the conventional alarm for a vehicle, since the movable core and the fixed core repeatedly collide with each other in a state where the horn switch is turned on, abrasion between the movable core and the fixed core increases with an increase in the number of collisions, and the amplitude amount of the vibration plate increases. If the amplitude of the vibrating plate is increased, the life of the vehicle alarm may be shortened due to breakage of the vibrating plate or the like.

An object of the present disclosure is to provide an alarm for a vehicle capable of improving a product life.

An aspect of the present disclosure provides an alarm for a vehicle, including: a housing having an opening; a coil housed in the case and generating a magnetic force by energization; a fixed iron core accommodated in the housing; a vibration plate provided so as to cover the opening; a movable iron core coupled to the diaphragm and axially displaced toward the fixed iron core by a magnetic attraction force generated by energizing the coil; a soundboard combined with the movable core to amplify a sound generated when the movable core collides with the fixed core; and a surface hardening layer formed on the entire surface of each of the fixed iron core and the movable iron core and having hardness harder than that of the base material, wherein at least one of the fixed iron core and the movable iron core has a curved convex surface at a collision portion between the fixed iron core and the movable iron core.

According to this alarm for a vehicle, the surface hardened layer is formed on the entire surface of each of the fixed iron core and the movable iron core, and at least one of the fixed iron core and the movable iron core has a curved convex surface formed at a collision portion of the fixed iron core and the movable iron core. With this structure, the surface area of the portion where the movable iron core collides with the fixed iron core can be reduced. Further, since the opposing surface-hardened layer collides with the surface-hardened layer, abrasion of the surface of the collision portion can be suppressed, and exposure of the base material can be delayed.

Since the curved convex surface is provided at the collision portion of at least one of the fixed iron core and the movable iron core, the collision portion of the surface hardened layer and the surface hardened layer can be formed around the base material even after the base material is exposed. The collision portion can suppress abrasion of the base material exposed inside. Such a wear suppression effect can suppress an increase in the moving distance of the movable core with respect to the fixed core, and can suppress an increase in the amplitude amount of the diaphragm. Therefore, the alarm for a vehicle can be provided, which can improve the product life.

Drawings

The foregoing and other objects, features, and advantages of the present disclosure will become more apparent from the following detailed description, which proceeds with reference to the accompanying drawings. In the drawings, there is shown in the drawings,

fig. 1 is a sectional view showing the structure of a vehicle alarm device of a first embodiment.

Fig. 2 is a plan view showing a state after the movable iron core, the vibration plate, the shell type horn, and the like are removed from the alarm for a vehicle of the first embodiment.

Fig. 3 is a partial sectional view showing sectional shapes of the fixed iron core and the movable iron core in an unworn state of the first embodiment.

Fig. 4 is a partial sectional view showing a state where wear is increased at a collision portion of the fixed iron core and the movable iron core of the first embodiment.

Fig. 5 is a plan view showing a state where the base material of the collision portion with the movable iron core is exposed and the wear is increased.

Fig. 6 is a partial sectional view showing sectional shapes of the fixed iron core and the movable iron core in an unworn state of the second embodiment.

Fig. 7 is a partial sectional view showing a state where wear is increased at a collision portion of the fixed iron core and the movable iron core provided by the second embodiment.

Fig. 8 is a plan view showing a state where the base material of the collision portion with the movable iron core is exposed and the wear is increased.

Fig. 9 is a partial sectional view showing sectional shapes of the fixed iron core and the movable iron core in an unworn state of the third embodiment.

Fig. 10 is a partial sectional view showing a state where wear is increased at a collision portion of the fixed iron core and the movable iron core provided by the third embodiment.

Fig. 11 is a plan view showing a state where the base material of the collision portion with the movable iron core is exposed and the wear is increased.

Fig. 12 is a sectional view showing a fixing structure of a warning sound and a stand (bay) for a vehicle of a fourth embodiment.

Fig. 13 is a front view showing a contact surface with a bracket in the fixed core of the fourth embodiment.

Fig. 14 is a partial sectional view of the stationary core.

Fig. 15 is a sectional view showing a contact state of the stationary core with the bracket.

Detailed Description

Hereinafter, a plurality of embodiments for implementing the present disclosure will be described with reference to the drawings. In each of the embodiments, the same reference numerals are used for portions corresponding to the matters described in the previous embodiment, and redundant description may be omitted. In the case where only a part of the structure is described in each embodiment, other embodiments described above may be employed for other parts of the structure. In each embodiment, combinations of parts that can be combined are not specifically specified, and combinations of parts between embodiments can be combined even if not specified, as long as the combinations are not particularly hindered.

(first embodiment)

A vehicle alarm device 1 according to a first embodiment will be described with reference to fig. 1 to 5. The vehicle alarm 1 is mounted on a vehicle such as an automobile or a motorcycle, for example, and generates a warning sound to the outside, and is also called an electromagnetic horn. The vehicle alarm device 1 emits a warning sound to the outside of the vehicle when a predetermined operation unit in the vehicle is operated. The predetermined operation portion is a horn switch provided on, for example, a steering device or a steering wheel, which is operated by the driver. The vehicle alarm 1 is an electromagnetic alarm device that generates an alarm sound corresponding to an operating voltage.

As shown in fig. 1, the vehicle alarm 1 is mounted on a front portion of a vehicle, for example, a vehicle-side member such as a front portion of a radiator, via a bracket 5. As shown in fig. 1, the vehicle alarm device 1 is mounted on a vehicle in a state in which the movable iron core 4 is positioned further forward than the fixed iron core 22 and the axial directions of the movable iron core 4 and the fixed iron core 22 are aligned in the front-rear direction. The vehicle alarm 1 includes: a bottomed cylindrical case 11, and an electromagnetic coil unit 2 housed and fixed in the vicinity of the center in the case 11. The alarm device 1 for a vehicle is a plate-shaped member having a vibrating plate 3 fixed to a housing 11 so as to cover an opening 112a of the housing 11 constituting an outer contour. The vibration plate 3 is also referred to as a diaphragm. The diaphragm 3 vibrates in accordance with the axial displacement of the movable iron core 4, and the air is vibrated by the vibration. The electromagnetic coil unit 2 includes a coil 20, a bobbin 21, and a fixed core 22. The coil 20 is formed by winding a coil wire around a bobbin 21 made of resin.

The alarm 1 for a vehicle includes: a movable iron core 4 fixed near the center of the diaphragm 3 and disposed opposite to the fixed iron core 22; and a bracket 5 fixed to the bottom of the housing 11 so as to be mounted to a vehicle or the like. The solenoid section 2 is disposed around the axis of the case 11. The case 11 and the diaphragm 3 are members formed by press-molding a plate material of an iron-based magnetic material into a concave shape in order to constitute a part of a magnetic circuit of the electromagnetic coil unit 2. The center hole 30 of the diaphragm 3 is fitted into the center hole 9a of the resonance plate 9 in the small diameter portion 41 located in the front portion of the movable core 4, and the movable core 4 is formed integrally with the diaphragm 3 and the resonance plate 9 in a state of being caulked and fixed. The small diameter portion 41 constitutes a coupling portion to couple the diaphragm 3 and the resonator plate 9. The small diameter portion 41 is a joint portion with the diaphragm 3 and the resonance plate 9, which is caulked to join the diaphragm 3 and the resonance plate 9 as other members to the movable core 4.

The small diameter portion 41 of the front portion of the movable iron core 4 is caulked in a state of being inserted into the center portion of the diaphragm 3, whereby the movable iron core 4 is fixed to the diaphragm 3. The contact portion 43 of the movable core 4 is closer to the fixed core 22 than the small diameter portion 41, and the contact portion 43 is a portion connecting the small diameter portion 41 and the large diameter portion 42. The contact portion 43 contacts the peripheral portion of the central hole portion 30 of the diaphragm 3.

The fixed core 22 is fixed to the bracket 5 for mounting to the vehicle together with the center portion of the bottom portion 110 of the housing 11 by a fixing method such as caulking. A rear side end portion 22b provided in the fixed core 22 is a coupling portion with the bracket 5, and the rear side end portion 22b is caulked to couple the fixed core 22 to the bracket 5 as another member. The fixed core 22 may be fixed to the bracket 5 together with the center portion of the bottom portion 110 of the housing 11 by nut fastening or the like.

The housing 11 has: a disk-shaped bottom portion 110 located at the rear end, an intermediate flat portion 111 formed by cylindrically rising from the periphery of the bottom portion 110 and having a disk-shaped protruding front end portion, and an outer peripheral edge portion 112 located at the front end are integrally formed. The outer peripheral edge 112 forms an opening 112a of the housing 11, and is formed to protrude from a front end portion formed by rising from the peripheral edge of the intermediate flat portion 111 toward the front cylinder. The outer peripheral portion of the diaphragm 3 is crimped so as to be crimped to the outer peripheral edge portion 112, and is fixed to the housing 11. The diaphragm 3 covers the opening 112 a.

The bobbin 21 is an insulating member integrally formed with a cylindrical portion 210, a flange portion 211 protruding from an end of the cylindrical portion 210 on the diaphragm 3 side in a disc shape, a first fixed portion 212 protruding outward from the flange portion 211, a second fixed portion 213, and the like. The coil 20 formed by winding a winding wire is provided on the outer peripheral surface of the cylindrical portion 210. A fixed core 22 is provided inside the cylindrical portion 210 concentrically with the bobbin 21 and the coil 20. In the bobbin 21, the flange portion 211 forms an end surface extending from the distal end of the cylindrical portion 210 to the periphery. The flange 211 covers the tip of the coil 20 and the end of the diaphragm 3.

A bobbin 21 having a fixed core 22 and a coil 20 is provided on the front side of the bottom portion 110 of the housing 11. An end face 22a including the axial front end of the fixed iron core 22 faces an end face 4a including the axial front end of the movable iron core 4, and the end face 22a is a collision portion with the movable iron core 4. In the vehicle alarm 1, when the coil 20 is not energized, a gap of a predetermined distance, that is, a so-called air gap, is formed between the end face 4a of the movable iron core 22 and the end face 22a of the fixed iron core 22. The fixed core 22 is present inside the cylindrical portion 210 of the bobbin 21. In other words, the side surface of the fixed core 22 is surrounded by the cylindrical portion 210.

The fixed iron core 22 has a surface hardened layer 22h formed on the entire surface and having a hardness harder than that of the base material. The movable iron core 4 has a surface-hardened layer 4h formed on the entire surface and having a hardness harder than that of the base material. The surface hardened layer 4h is a thin layer formed by surface treatment of the movable iron core 4. The surface hardened layer 22h is a thin layer formed by surface treatment of the fixed core 22. The surface hardened layers 4h and 22h are formed by a predetermined plating process and a predetermined coating process, and have a hardness of 400 vickers or higher. The hardness of the surface hardened layer 4h and the surface hardened layer 22h can be measured in accordance with JISZ2244 which gives vickers hardness test method.

The alarm for a vehicle capable of achieving the object of the present disclosure has a curved convex surface that is provided at a collision portion between the fixed core 22 and the movable core 4 and protrudes toward the movable core 4 side, in at least one of the fixed core 22 and the movable core 4. In the vehicle alarm 1 of the first embodiment, the movable iron core 4 is provided with a curved convex surface at a collision portion with the fixed iron core 22. The curved convex surface provided on the movable iron core 4 is a curved surface that is convex toward the fixed iron core 22 side. A curved convex surface is provided on the entire or a part of an end surface 4a of the movable iron core 4 facing the fixed iron core 22. The curved convex surface is provided at least on a center portion 4ac of the end surface 4a passing through the center axis of the movable iron core 4. The curved convex surface is provided at least at a central portion of the end surface 4a of the movable iron core 4, which is axially opposed to the fixed iron core 22. Since the surface hardened layer 4h is formed on the entire surface of the movable iron core 4, the surface hardened layer 4h is also formed on the curved convex surface. When the coil 20 is not energized, the curved convex surface of the movable iron core 4 is separated from the end surface 22a of the fixed iron core 22.

With this structure, when the horn switch is turned on, the surface hardened layer 4h formed on the end surface 4a of the movable iron core 4 repeatedly collides with the surface hardened layer 22h formed on the surface of the curved convex surface. At this time, since the surface hardened layer 4h of the portion where the curved convex surface is formed contacts the surface hardened layer 22h at a point or a small area, the contact area of the collision portion between the movable core 4 and the fixed core 22 is small, and the portions having higher hardness than the base material repeatedly collide with each other. The collision between the surface hardened layer 4h and the surface hardened layer 22h contributes to suppressing the wear of the collision portion between the base material of the movable core 4 and the base material of the fixed core 22, and can delay the increase in the amplitude of the diaphragm 3 as the wear increases.

The surface hardened layers 4h, 22h can be formed on the surfaces of the fixed iron core 22 and the movable iron core 4 by, for example, electrolytic nickel plating, electroless nickel plating, hard chrome plating, DLC (Diamond-Like Carbon) coating, DLC-UM coating, molybdenum coating, or the Like.

The nickel electroplating is a technique of dissolving nickel used in an anode by applying current, obtaining electrons from nickel ions in the solution, and depositing nickel on a cathode (iron or the like) to perform electroplating. Since electrolytic nickel plating has a higher plating deposition rate than electroless nickel plating, the manufacturing cost can be reduced.

Electroless nickel plating is a technique in which hypophosphite, which is a reducing agent, is oxidized to form phosphite, and at this time, electrons are released to reduce nickel ions, thereby forming a nickel plating film. As described above, electroless nickel plating and electrolytic nickel plating are greatly different in the mechanism of reduction reaction of precipitated metal. Compared with hard chrome plating and nickel plating, electroless nickel plating is not affected by current distribution, and therefore a hardened layer having a uniform thickness can be formed on the surfaces of the fixed iron core 22 and the movable iron core 4. As described above, the surface hardened layers 4h and 22h are preferably layers containing nickel as a main component.

Hard chromium plating is a technique in which chromium is electrodeposited on the surface of a cathode by immersing an object to be plated as the cathode in a solution containing chromium trioxide as a main component and chromium ions. The surface hardened layer formed by hard chrome plating also has high hardness and excellent wear resistance in the surface hardened layer formed by plating. The surface hardened layer formed by hard chrome plating has a hardness of, for example, 800 vickers or higher. As described above, the surface hardened layers 4h and 22h are preferably layers having chromium as a main component.

DLC coating is a technique for coating a thin film mainly composed of carbon and hydrogen on a metal surface. Diamond-like carbon is an amorphous (noncrystalline) hard film composed mainly of hydrocarbons or carbon allotropes. Since the coating is very thin and hard, it has high hardness and low abrasion. The surface hardened layer formed by DLC coating has a hardness of, for example, vickers hardness 1500 or more. As described above, the surface hardened layers 4h and 22h are preferably thin films mainly composed of carbon and hydrogen.

DLC-UM coating is a technique for removing foreign particles on a metal surface and forming a thin film using solid graphite as a raw material. The surface hardened layer formed by DLC-UM coating has a hardness twice or more and a higher heat resistance temperature than the surface hardened layer formed by DLC coating. As described above, the surface hardened layers 4h and 22h are preferably thin films containing solid graphite as a main component.

Molybdenum coating is a technique for coating a metal surface with a layer containing molybdenum disulfide as a main component, and can form a coating film having low wear resistance and high lubricity. The surface hardened layer formed by molybdenum coating can provide smooth sliding for members requiring sliding properties such as the movable iron core 4, in addition to forming a hardened layer capable of suppressing surface wear. As described above, the surface hardened layers 4h and 22h are preferably thin films containing molybdenum as a main component.

As shown in fig. 2, the first fixed part 212, the movable contact support plate 7 made of a metal spring material having elasticity, and the fixed contact support plate 8 made of a metal having conductivity are laminated on the intermediate flat part 111 of the housing 11. An insulating member is interposed between the movable contact support plate 7 and the fixed contact support plate 8. The stacked members are integrally fixed by a first metal rivet 90 fixed to the intermediate flat portion 111 by caulking. One end portion of the winding wire extending from the coil 20 is provided between the movable contact supporting plate 7 and the first fixed part 212 in a state where an insulating film covering the conductor is peeled off, and is pressed against the head of the first rivet 90 in accordance with the caulking fixation of the first rivet 90. Thus, one end portion of the winding wire is conducted to the movable contact support plate 7.

The second fixed portion 213 is laminated on the other part of the intermediate flat portion 111. The second fixed portion 213 is fixed to the housing 11 by a second metal rivet 91 that is fixed to the intermediate flat portion 111 by caulking. The other end portion of the winding wire extending from the coil 20 in the solenoid part 2 is provided along the periphery of the shaft portion of the second rivet 91 with the insulating film covering the conductor peeled off, and is pressed against the head portion of the second rivet 91 in accordance with the caulking fixation of the second rivet 91. In this way, by the other end portion of the coil being pressed against the head of the second rivet 91, the conductor at the end portion of the coil is conducted to the second rivet 91. Here, the conductor of the winding is made of a copper wire, a conductive material other than a copper wire, or a material in which different conductive materials are combined. The bobbin 21 is fixed to the housing 11 at two positions, i.e., a first rivet 90 and a second rivet 91.

Also, the second rivet 91 is insulated from the housing 11 by an insulating member. The second rivet 91 is in conduction with a connector terminal inside the connector 13. The positive potential of the battery is directed to the connector terminal via the horn switch. Therefore, the second rivet 91 is a rivet located on the current-carrying side in the solenoid portion 2. The vehicle alarm 1 may further include a connector terminal that is electrically connected to a terminal end portion of the winding wire pressed against the movable contact support plate 7 by caulking of the first rivet 90.

The movable contact support plate 7 is provided with a movable contact portion 70 protruding toward the fixed contact support plate 8. The fixed contact support plate 8 is provided with a fixed contact portion 80 protruding toward the movable contact support plate 7 at a position corresponding to the movable contact portion 70. The movable contact portion 70 and the fixed contact portion 80 are disposed to be opposed to each other in the axial direction. When the coil 20 is not energized, the movable contact portion 70 is pressed toward the fixed contact support plate 8 by the spring force of the movable contact support plate 7, and forms a normally closed contact which is in contact with the fixed contact portion 80.

A large diameter portion 42 protruding radially outward from the other portions is formed on the entire outer peripheral surface of the movable core 4. The large diameter portion 42 has a pressing portion 42a, and the pressing portion 42a is in contact with the pressed portion 7a of the movable contact support plate 7 near the horn center and presses the pressed portion rearward, that is, toward the fixed core 22. The pressing portion 42a is made of an insulating material. The pressing portion 42a can be formed integrally with the movable core 4 by caulking the rear side of the pressing portion 42a to the movable core 4. The caulking portion 44 is a plastically deformed processing portion that is caulked to couple the movable iron core 4 to the pressing portion 42 a. The fixed core 22 magnetized when the coil 20 is energized attracts the movable core 4, and the large diameter portion 42 is displaced rearward, that is, toward the fixed core 22. Then, the pressed portion 7a of the movable contact support plate 7 is pressed toward the fixed core 22 by the pressing portion 42a of the large diameter portion 42, and the fixed contact portion 80 and the movable contact portion 70 are separated, and the contact portions are opened.

Next, the operation of the vehicle alarm 1 will be described. When the horn switch is turned on, the current from the in-vehicle power supply flows through the second rivet 91, the other end portion of the winding, and the coil 20 in this order from the connection terminal. Further, the current flows through the one end portion of the winding, the movable contact support plate 7, the movable contact portion 70, the fixed contact portion 80, the fixed contact support plate 8, the first rivet 90, the housing 11, the fixed core 22, the bracket 5, and the vehicle body (ground) in this order.

In the vehicle alarm 1, the other end portion of the wire is electrically connected to the second rivet 91, and the one end portion of the wire is electrically connected to the movable contact support plate 7. Thereby, the electromagnetic force of the electromagnetic coil unit 2 acts on the gap between the movable iron core 4 and the fixed iron core 22, and the movable iron core 4 is attracted to the fixed iron core 22. When the movable core 4 moves in the axial direction due to the magnetic attraction force generated by the fixed core 22, the central portion of the diaphragm 3 moves integrally with the movable core 4 and deforms in a state where the peripheral edge portion is fixed. By such displacement of the movable iron core 4, the large diameter portion 42 of the movable iron core 4 presses the pressed portion of the movable contact support plate 7, and the movable contact portion 70 is separated from the fixed contact portion 80. As a result, the energization to the solenoid portion 2 is cut off and the electromagnetic force disappears, so that the movable iron core 4 is returned to the original position by the elastic force of the diaphragm 3, and the closed state of the movable contact portion 70 and the fixed contact portion 80 is restored. When the voltage applied to the coil 20 increases, the movable iron core 4 approaches the fixed iron core 22 due to the magnetic attraction force from the fixed iron core 22. By repeating these operations, the end face 4a of the movable iron core 4 repeatedly collides with the end face 22a of the fixed iron core 22, and the diaphragm 3 and the soundboard 9 vibrate at high frequency, whereby sound waves are emitted forward.

Fig. 3 is a diagram showing the sectional shapes of the fixed iron core 22 and the movable iron core 4 in an unworn state. Fig. 4 is a sectional view showing a state where abrasion of a collision portion between the fixed iron core 22 and the movable iron core 4 is increased and the base material is exposed at the center portion. Fig. 5 is a plan view of end faces of the fixed iron core 22 and the movable iron core 4 in the state of fig. 4 as viewed from the axial direction. For the sake of easy understanding, fig. 3 and 4 exaggeratedly show the thickness of the surface hardened layer 4h and the surface hardened layer 22h and the state of the progress of wear. When the horn switch is turned on, the end face 4a of the movable iron core 4 repeatedly collides with the end face 22a of the fixed iron core 22 at the center portion 4ac through which the center axis shown by the one-dot chain line passes. At this time, the top of the curved convex surface of the end surface 4a continues to collide with the end surface 22a in a state of approximate point contact. Therefore, as the number of times of collision increases, the surface hardened layer 4h formed on the top of the curved convex surface wears, and the surface hardened layer 22h formed on the portion including the center of the end surface 22a wears. The top of the curved convex surface is arranged to contain the central portion 4 ac.

Since the surface hardened layer 4h and the surface hardened layer 22h are provided at the collision portion, the wear of the surface can be delayed as compared with the case where the fixed iron core and the movable iron core, which are not provided with the surface hardened layer, collide. Since the collision portion is constituted by the end face 4a having the curved convex surface and the end face 22a being the flat surface, only the top portion of the curved convex surface wears and the center portion 22ac of the flat surface in contact with the top portion slightly wears concavely in the case where the number of collisions is small. As the number of impacts increases, wear increases, and as shown in fig. 4, a flat portion of a substantially circular shape is generated at the top of the curved convex surface, which continues to collide with the central portion 22ac of the end surface 22 a. As the number of times of collision further increases, the harder surface hardened layer wears little by little at the wear rate until the thickness of the surface hardened layer 4h and the surface hardened layer 22h becomes thinner and disappears at the flat portion of the curved convex surface and the central portion 22ac of the end surface 22 a. When the wear increases until the surface hardened layer disappears, the base materials of the fixed core 22 and the movable core 4 are exposed. In the alarm device 1 for a vehicle, since the surface hardened layer 4h collides with the surface hardened layer 22h until the base material is exposed, the wear of the end surface 4a and the end surface 22a can be suppressed.

When the number of collisions is accumulated from the state where the base material is exposed to the end surfaces 4a and 22a, the collision surface expands annularly around the exposed portion of the base material, thereby increasing wear around the center portion 22ac of the end surface 22 a. The collision surface at this time is an annular portion hatched with diagonal lines inside the two-dot chain line in fig. 5. The portion surrounded by the annular portion is a portion where the base material is exposed. Since the annular surface of the end surface 4a repeatedly collides with the annular surface of the end surface 22a, the surface hardened layer 4h continuously collides with the surface hardened layer 22 h. This can delay the radial expansion of the base material exposed in the state of being surrounded by the annular surface.

As described above, the movable iron core 4 and the fixed iron core 22 gradually wear away from the first collision stage of point contact, through the second collision stage in which the circular portion contacts the surface of the circular portion, to the third collision stage in which the annular portion of the surface-hardened layer 4h contacts the surface of the annular portion of the surface-hardened layer 22 h. By passing through such a stage, the movable core 4 and the fixed core 22 can be made to wear the surfaces later than when the fixed core and the movable core, which are not provided with the surface hardening layer, collide with each other.

The operation and effect of the vehicle alarm device 1 according to the first embodiment will be described. The vehicle alarm 1 includes: a housing 11 having an opening 112 a; a coil 20 which is accommodated in the case 11 and generates a magnetic force by being energized; and a fixed core 22 accommodated in the case 11 and the diaphragm 3 and provided to cover the opening 112 a. The vehicle alarm 1 includes: a movable iron core 4 coupled to the diaphragm 3 and axially displaced toward the fixed iron core 22 by a magnetic attractive force; and a soundboard 9 which is combined with the movable iron core 4 and amplifies a sound generated when the movable iron core 4 collides with the fixed iron core 22. The alarm 1 for a vehicle includes surface hardened layers 4h, 22h, and the surface hardened layers 4h, 22h are formed on the entire surfaces of each of the fixed iron core 22 and the movable iron core 4 and have hardness harder than that of the base material. At least one of the fixed iron core 22 and the movable iron core 4 has a curved convex surface formed at a collision portion of the fixed iron core 22 and the movable iron core 4.

According to the alarm 1 for a vehicle, the surface hardened layer 22h is formed on the entire surface of the fixed iron core 22, and the surface hardened layer 4h is formed on the entire surface of the movable iron core 4. At least one of the fixed iron core 22 and the movable iron core 4 has a curved convex surface formed at a collision portion between the fixed iron core 22 and the movable iron core 4. According to this structure, the surface area of the portion where the movable iron core 4 collides with the fixed iron core 22 can be reduced. Further, since the surface hardened layer 4h collides with the surface hardened layer 22h, it is possible to suppress wear of the surface of the collision portion between the fixed iron core 22 and the movable iron core 4 when the base materials collide with each other.

Since the curved convex surface is formed at the collision portion of at least one of the fixed iron core 22 and the movable iron core 4, the surface hardened layer collides with the surface hardened layer around the exposed base material even after the base material is exposed. Since such a collision surface can be formed, increase in abrasion of the base material and increase in exposed area can be suppressed. Such a surface wear suppression effect can suppress an increase in the moving distance of the movable iron core 4 with respect to the fixed iron core 22 with an increase in the number of collisions, and can therefore suppress an increase in the amplitude amount of the diaphragm 3, for example. Therefore, the vehicle alarm 1 can improve the product life.

The movable iron core 4 is provided with a curved convex surface projecting toward the fixed iron core 22 side. According to this structure, the surface hardened layer 4h of the curved convex surface of the movable iron core 4 collides with the surface hardened layer 22h of the fixed iron core 22 to suppress the collision area, and thus contributes to suppressing the wear of the surface of the collision portion.

Further, the fixed core 22 is provided with a flat surface orthogonal to the axial direction at a collision portion with the curved convex surface of the movable core 4. According to this structure, the surface hardened layer 4h of the movable iron core 4 and the surface hardened layer 22h of the fixed iron core 22 collide with each other at point contact while the total number of collisions is small. Therefore, the collision area between the fixed iron core 22 and the movable iron core 4 is small, and therefore the alarm 1 for a vehicle can be provided in which the exposure time of the base materials of the fixed iron core 22 and the movable iron core 4 can be greatly delayed.

The surface hardened layers 4h and 22h may be plating layers formed by electroplating nickel having nickel as a main component. According to this structure, the plating deposition rate can be increased while suppressing the manufacturing cost, and the surface hardened layer 4h and the surface hardened layer 22h having the surface hardness that can reduce the wear rate of the end face 4a and the end face 22a can be provided.

The surface hardened layers 4h and 22h may be plating layers formed by electroless nickel plating containing nickel as a main component. According to this structure, a hardened layer having a uniform thickness can be formed on the surface of the fixed iron core 22 or the movable iron core 4, and the surface hardened layer 4h and the surface hardened layer 22h having a surface hardness that can reduce the wear rate of the end face 4a and the end face 22a can be provided.

The surface hardened layers 4h and 22h may be plating layers formed by hard chromium plating containing chromium as a main component. According to this structure, the surface hardened layer 4h and the surface hardened layer 22h having high hardness and excellent wear resistance and capable of reducing the wear rate of the end surface 4a and the end surface 22a can be provided.

The surface hardened layers 4h and 22h may be thin films formed by diamond-like carbon coating, and amorphous carbon hard films containing carbon and hydrogen. According to this structure, the surface hardened layer 4h and the surface hardened layer 22h which are very thin, have high hardness, low abrasion, and can reduce the abrasion speed of the end face 4a and the end face 22a can be provided.

The surface hardened layers 4h and 22h may be layers formed by coating molybdenum, with molybdenum as a main component. According to this structure, since a coating film having low wear properties and high lubricity can be formed, it is possible to provide the surface hardened layer 4h and the surface hardened layer 22h having surface hardness that can improve the slidability of the movable iron core 4 and reduce the wear rate of the end face 4a and the end face 22 a.

The surface hardened layers 4h and 22h may have a hardness of 400 vickers or more. According to this configuration, it is possible to provide the alarm device 1 for a vehicle, which can reduce the wear rate of the surface hardened layer 4h of the end surface 4a and the surface hardened layer 22h of the end surface 22a, and which does not significantly reduce the wear life with respect to the product life.

(second embodiment)

In a second embodiment, a movable iron core 104 and a fixed iron core 122 in another embodiment of the first embodiment will be described with reference to fig. 6 to 8. In the second embodiment, the same configurations as those of the first embodiment are denoted by the same reference numerals in the drawings, and the same operational effects are obtained. Hereinafter, only the differences from the first embodiment will be described

Fig. 6 is a diagram showing the sectional shapes of the fixed iron core 122 and the movable iron core 104 in an unworn state. Fig. 7 is a sectional view showing a state in which the abrasion of the collision portion between the fixed iron core 122 and the movable iron core 104 is increased and the base material is exposed at the center portion. Fig. 8 is a plan view of the end faces of the fixed iron core 122 and the movable iron core 104 in the state of fig. 7 as viewed from the axial direction. For the sake of easy understanding, fig. 6 and 7 show the surface hardened layer 4h and the surface hardened layer 22h in an exaggerated manner in terms of thickness and wear. The movable iron core 104 has an end face 4a forming a flat surface. The fixed core 122 has an end face 22a, and a curved convex surface protruding toward the movable core 104 is formed on the end face 22 a. A curved convex surface formed on the whole or a part of the end surface 22a of the fixed core 122. The curved convex surface is formed at least at the center portion 22ac of the end surface 22a passing through the center axis of the fixed core 122. A curved convex surface formed at least in the center of the end surface 22 a. Since the surface hardened layer 22h is formed on the entire surface of the fixed core 122, the surface hardened layer 22h is also formed on the curved convex surface. When the coil 20 is not energized, the curved convex surface of the fixed core 122 is separated from the end surface 4a of the movable core 104.

When the horn switch is turned on, the end face 4a of the movable iron core 104 repeatedly collides with the end face 22a of the fixed iron core 122 at the center portion 4ac through which the center axis shown by the one-dot chain line passes. At this time, the top of the curved convex surface of the end surface 22a continues to collide with the end surface 4a in a state of approximate point contact. Therefore, as the number of times of collision increases, the surface hardened layer 22h formed on the top of the curved convex surface wears, and the surface hardened layer 4h formed on the portion including the center of the end surface 4a also wears.

Since the surface hardened layer 4h collides with the surface hardened layer 22h, the wear of the surface can be delayed as compared with the case where the fixed iron core and the movable iron core, which are not provided with the surface hardened layer, collide. Since the collision portion is constituted by the end surface 22a having the curved convex surface and the end surface 4a being the flat surface, only the top portion of the curved convex surface wears and the center portion 4ac of the flat surface in contact with the top portion slightly wears concavely when the number of collisions is small. As the number of impacts increases, wear increases, and a flat portion of a substantially circular shape is generated at the top of the curved convex surface, as shown in fig. 7, and this flat portion continues to collide with the central portion 4ac of the end surface 4 a. As the number of times of collision further increases, the harder surface hardened layer wears little by little at the wear rate until the thickness of the surface hardened layer 22h and the surface hardened layer 4h becomes thinner and disappears in the flat portion of the curved convex surface and the central portion 4ac of the end surface 4 a. When the wear increases until the surface hardened layer disappears, the base materials of the fixed core 122 and the movable core 104 are exposed.

When the number of collisions is accumulated from the state where the base material is exposed to the end surface 4a and the end surface 22a, the collision surface expands annularly around the exposed portion of the base material, and further wear around the center portion 4ac of the end surface 4a increases. The collision surface in this case is an annular portion hatched with diagonal lines inside the two-dot chain line in fig. 8. The portion surrounded by the annular portion is exposed outside the base material. In the second embodiment, since the annular surface of the end surface 4a repeatedly collides with the annular surface of the end surface 22a and the surface hardened layer 4h continuously collides with the surface hardened layer 22h, the radial expansion of the exposed base material in a state of being surrounded by the annular surface can be delayed.

In this way, the movable iron core 104 and the fixed iron core 122 gradually wear away from the first collision stage of point contact through the second collision stage of surface contact between the circular portions to the third collision stage of surface contact between the annular portion of the surface hardened layer 4h and the annular portion of the surface hardened layer 22 h. By passing through such a stage, the movable core 104 and the fixed core 122 can be made to wear out the surfaces later than when the fixed core and the movable core, which are not provided with the surface hardening layer, collide.

According to the second embodiment, the fixed core 122 is provided with a curved convex surface protruding toward the movable core 104 side. According to this structure, the surface hardened layer 22h of the curved convex surface of the fixed iron core 122 collides with the surface hardened layer 4h of the movable iron core 104 to suppress the collision area, and thus contributes to suppressing the wear of the surface of the collision portion.

In the fixed iron core 122, a curved convex surface is provided at a collision portion with the movable iron core 104. Therefore, even after the base material is exposed, the surface hardened layer and the surface hardened layer collide with each other around the exposed base material. According to the second embodiment, since such a collision surface can be formed, it is possible to suppress increase in abrasion of the base material and increase in the exposed area.

According to the alarm 1 for a vehicle, the surface hardened layer 22h is formed on the entire surface of the fixed iron core 122, and the surface hardened layer 4h is formed on the entire surface of the movable iron core 104. At least one of the fixed core 122 and the movable core 104 has a curved convex surface formed at a collision portion between the fixed core 122 and the movable core 104. According to this structure, the surface area of the collision portion of the movable iron core 104 and the fixed iron core 122 can be reduced. Further, since the surface hardened layer 4h collides with the surface hardened layer 22h, abrasion of the surface of the collision portion between the fixed iron core 122 and the movable iron core 104 can be suppressed compared to the case where the base materials collide with each other.

(third embodiment)

In a third embodiment, a movable iron core 4 and a fixed iron core 122 in another embodiment of the first embodiment will be described with reference to fig. 9 to 11. In the third embodiment, the same configurations as those of the above-described embodiments are denoted by the same reference numerals in the drawings, and the same effects are obtained. Hereinafter, only the differences from the above embodiments will be described

Fig. 9 is a schematic diagram of the sectional shapes of the fixed iron core 122 and the movable iron core 4 in an unworn state. Fig. 10 is a sectional view showing a state in which the abrasion of the collision portion between the fixed iron core 122 and the movable iron core 4 is increased and the base material is exposed to the center portion. Fig. 11 is a plan view of the end faces of the fixed iron core 122 and the movable iron core 104 in the state of fig. 9 as viewed from the axial direction. For the sake of easy understanding, fig. 9 and 10 show the surface hardened layer 4h and the surface hardened layer 22h in an exaggerated manner in terms of thickness and wear. The movable iron core 4 has the same structure as that of the first embodiment. The fixed core 122 has the same structure as that of the second embodiment. The top of the curved convex surface of the end surface 4a and the top of the curved convex surface of the end surface 22a are disposed at positions where they collide with each other. When the coil 20 is not energized, the curved convex surface of the fixed core 122 is separated from the curved convex surface of the movable core 4.

During the horn switch on period, the end face 4a of the movable iron core 4 repeatedly collides with the end face 22a of the fixed iron core 122 at the center portion 4ac through which the center axis shown by the one-dot chain line passes. At this time, since the curved convex surface of the end surface 4a continues to collide with the curved convex surface of the end surface 22a in a state of approximate point contact, the surface hardened layer 22h formed on the end surface 4a wears and the surface hardened layer 4h formed on the end surface 22a also wears as the number of collisions increases.

In this case, since the surface hardened layer 4h and the surface hardened layer 22h collide with each other, wear of the surface can be delayed as compared with the case where the fixed iron core and the movable iron core, which are not provided with the surface hardened layer, collide with each other. Since the collision portion is formed of the end face 22a having the curved convex surface and the end face 4a having the curved convex surface, only the top portions of the curved convex surfaces of both the cores are worn out when the number of collisions is small. As the number of times of collision increases and wear increases, a flat portion having a substantially circular shape is generated at the top of the curved convex surface of the end surface 4a, and a flat portion having a similar substantially circular shape is generated at the top of the curved convex surface of the end surface 22 a.

Further, as the number of times of collision further increases, in each of the movable iron core 4 and the fixed iron core 122, the harder surface hardened layer wears little by little at the wear rate until the thickness of the surface hardened layer 22h and the surface hardened layer 4h becomes thinner and disappears. When the wear increases until the surface hardened layer disappears, the base materials of the fixed core 122 and the movable core 4 are exposed.

When the number of collisions is accumulated from the state where the base material is exposed to the end surfaces 4a and 22a, the collision surface is expanded annularly around the exposed portion of the base material, thereby increasing the wear around the exposed base material. The collision surface in this case is an annular portion hatched with diagonal lines inside the two-dot chain line in fig. 11. In the third embodiment, since the annular surface of the end surface 4a and the annular surface of the end surface 22a repeatedly collide with each other and the surface hardened layer 4h and the surface hardened layer 22h continue to collide with each other, expansion of the exposed base material in a state surrounded by the annular surface can be delayed.

In this way, the movable core 4 and the fixed core 122 gradually wear down from the first collision stage of point contact through the second collision stage in which the circular portion comes into contact with the surface of the circular portion to the third collision stage in which the annular portion of the surface-hardened layer 4h comes into contact with the surface of the annular portion of the surface-hardened layer 22 h. By passing through such a stage, the movable core 4 and the fixed core 122 can be made to have a surface wear delayed as compared with a case where a fixed core and a movable core having no surface hardened layer collide.

According to the third embodiment, the fixed iron core 122 is provided with a curved convex surface at the collision portion with the movable iron core 4. The movable iron core 4 is provided with a curved convex surface at a collision portion with the fixed iron core 122. According to this structure, the surface hardened layer 4h of the movable iron core 4 and the surface hardened layer 22h of the fixed iron core 122 collide with each other at point contact while the total number of collisions is small, and therefore the collision area therebetween can be reduced. Further, since the surface hardened layer 4h collides with the surface hardened layer 22h, the time for exposing the base materials can be delayed with respect to the case where the base materials collide with each other.

Since the curved convexities that collide with each other are provided in both the fixed core 122 and the movable core 4, the surface hardened layer and the surface hardened layer collide with each other around the exposed base material even after the base material is exposed. According to the third embodiment, since such a collision surface can be formed, it is possible to suppress increase in abrasion of the base material and increase in the exposed area.

(fourth embodiment)

In a fourth embodiment, a fixed core 222 according to another embodiment of the first embodiment will be described with reference to fig. 12 to 15. In the fourth embodiment, the same configurations as those of the above-described embodiments are denoted by the same reference numerals in the drawings, and the same effects are obtained. Only the differences from the foregoing embodiments will be described

The fixed core 222 has a friction force increasing portion 222d provided on a contact surface 222c which is a portion in contact with the bracket 5. As shown in fig. 12 and 13, the contact surface 222c is an annular surface surrounding the base of the rear side end 222b provided on the fixed core 222. The contact surface 222c is formed as a surface orthogonal to the axial center of the columnar rear-side end 222 b.

In the fourth embodiment, the fixed core 222 is fixed to the bracket 5 together with the center portion of the bottom portion 110 of the housing 11 by a fastening method such as a nut 6. An external thread portion screwed with the internal thread portion of the nut is formed at the rear side end portion 222b of the fixed core 222.

The friction force increasing part 222d serves to increase a force that hinders the relative movement of the bracket 5 and the stationary core 222. The friction increasing portion 222d provides a resistance force that suppresses the movement of the holder 5 fixed on the contact face 222c relative to the movement of the fixed core 222. The friction force increasing portions 222d can be formed by processing the surface hardened layer 22h of the contact surface 222c by laser irradiation or punching.

As shown in fig. 14 and 15, the friction force increasing portion 222d includes a plurality of concave and convex portions provided in a predetermined range of the surface hardening layer 22h of the contact surface 222 c. The predetermined range of the uneven portion is formed by, for example, a plurality of minute ridges and valleys adjacent to the ridges. The peak portions and the trough portions included in the uneven portions of a predetermined range extend in the same direction. In order to achieve the biting state into the surface of the strut 5 as shown in fig. 15, the peaks are preferably in the shape of sharp protrusions. Since the harder surface hardened layer 22h is a sharp pointed object, the mountain portion easily bites into the surface of the strut 5. In this regard, the processing treatment is preferably performed by laser irradiation.

As shown in fig. 13, the plurality of concave-convex portions are dispersed at intervals over the entire circumference of the contact surface 222c to form a ring shape. The concave-convex portion is formed in the rectangular shape. The concave-convex portion is formed in a predetermined range longer in the radial direction than in the circumferential direction. The friction force increasing portion 222d can function to increase the friction force against the stent 5 in both the circumferential direction and the radial direction.

The fixed core 222 of the fourth embodiment has a contact surface 222c that is in contact with the pillar 5 in a state of being fixed to the pillar 5, the pillar 5 being used for attachment to a vehicle-side member. The surface hardening layer 22h of the contact surface 222c is provided with a friction force increasing portion 222 d. The friction force increasing part 222d is a plurality of concave and convex parts respectively formed in a predetermined range. According to this configuration, since the flat surface and the concave-convex portion are alternately provided on the contact surface 222c, a portion having a small friction force and a portion having a large friction force can be alternately distributed. With this distribution arrangement, the anti-slip effect of the bracket 5 with respect to the stationary core 222 is not biased to one place but is directed to a wider range, and therefore a stable fixing force can be provided.

The friction force increasing portion 222d is formed by arranging a plurality of concave and convex portions in a predetermined range in the circumferential direction on the contact surface 222c which is an annular surface. A flat surface is provided between adjacent concave and convex portions. The plurality of concave-convex portions are provided radially and annularly on the entire contact surface 222 c. According to this configuration, the friction force can be provided uniformly to the holder 5 over the entire circumference. The friction force increasing portion 222d effectively reduces the rotational force of the holder 5 rotating with respect to the contact surface 222c by dispersing the generated friction force over the entire circumference. According to this friction-force increasing portion 222d, the friction force provided by one of the concave-convex portions in the predetermined range can be set small, and the friction force required as a whole can be provided by the dispersed arrangement.

(other embodiments)

The present invention is not limited to the illustrated embodiments. This summary includes the embodiments listed and variations thereof that would be made by one skilled in the art based thereon. For example, the present disclosure is not limited to the combinations of the components and elements disclosed in the embodiments, and may be implemented by various modifications. The present disclosure may be implemented in various combinations. The present disclosure may also have an additional portion that can be added to the embodiments. The present disclosure also includes embodiments in which components and elements are omitted from the embodiments. The present disclosure also includes substitutions and combinations of parts and elements between one embodiment and another embodiment. The technical scope of the disclosure is not limited to the description of the embodiments. The technical scope of the present disclosure is defined by the description of the claims, and all changes that come within the meaning and range of equivalency of the claims are to be embraced therein.

The surface hardening layer provided in the vehicle alarm device that can achieve the object of the present disclosure is not limited to the surface treatment described in the foregoing embodiment.

The vehicle alarm device capable of achieving the object of the present disclosure also includes a mode in which the end surface 22a of the fixed core and the end surface 4a of the movable core provided in the above embodiments are not entirely but partially provided with a curved convex surface.

The friction force increasing portion 222d of the fourth embodiment can also be applied to a device in which the fixed core is fixed to the bracket 5 by a fixing method such as caulking as in the first embodiment, and has the same effect.