GB2345785A

GB2345785A - An alarm case with liquid buffering means and drainage device

Info

Publication number: GB2345785A
Application number: GB0000087A
Authority: GB
Inventors: Tatsuya Kitanaka; Toshio Hayashi
Original assignee: Denso Corp
Current assignee: Denso Corp
Priority date: 1999-01-12
Filing date: 2000-01-05
Publication date: 2000-07-19
Anticipated expiration: 2020-01-05
Also published as: GB2345785B; JP2000209686A; GB0000087D0

Abstract

An alarm apparatus capable of preventing water from entering into a case. An alarm apparatus 1 includes a sounding body 2 and a case 5 for containing sounding body. The case is made up of a lower case 5A, an upper case (5B) and a cover case 5C. The upper case forms a sound passage for externally emitting sound generated from the sounding body with the cover case. The sound passage includes a central sound passage portion 16 opening to a substantially center portion of the sounding body and a peripheral sound passage portion 17 meanderingly provided in an S-shape from the central sound passage portion to a periphery. Abufferwall 18 extending to inside of the peripheral sound passage portion is provided in an outlet side opening portion 17a of the peripheral sound passage portion. A first depression portion 19 and a second depression portion 20 are provided on the way in the peripheral sound passage portion. Here, entered water collides with the buffer wall to reduce its speed and to weaken its momentum, and tends to be temporally accumulated in the first or second depression portion and immediately drained externally, even if the water enters from an outlet of the peripheral sound passage portion. As a result, it can prevent the water from further entering into a casing body through the peripheral sound passage portion and the central sound passage portion.

Description

ALARM APPARATUS The present invention relates to alarm apparatuses, and particularly to an alarm apparatus used for a security system (anti-theft system) of, for example, vehicle and so on.

An alarm apparatus 100 as shown in FIG. 4 as a related art is provided with a case (described later) including a sounding body 110 as a sound source, and a sound passage (described later) for emitting sound generated by the sounding body 110.

The case is provided with a lower case 120 and an upper case 130, both of which constitute a casing body, and a cover case 140 constitutes the sound passage by being combined with the upper case 130.

The sound passage includes a central sound passage portion 150, which opens at a substantially center portion against the sounding body, and a peripheral sound passage portion 160, which is meanderingly provided in an S-shape fromthe central sound passage portion 150 to external. The peripheral sound passage portion 160 is concentricity arranged with the central sound passage portion 150, and its outlet is opened to a case surface (right side surface of FIG. 4).

However, in the conventional alarm apparatus 100, the outlet of the peripheral sound passage portion 160 is externally opened for its function. Therefore, when water is splashed from, for example, the case surface (right side of FIG. 4), there is a high possibility for water to flood into the case from the outlet of the peripheral sound passage portion 160. Particularly, a problem, in which water entered from the peripheral sound passage portion 160 may easily flood into the sounding body 110 or a signal processing circuit portion 170 contained in the case through the central sound passage portion 150, may occur, when it is difficult to form the peripheral sound passage portion 160 meandered several times due to a downsizing of the apparatus, or when it is impossible to secure a large difference in height between an outlet opening surface of the peripheral sound passage portion 160 and an opening surface of the central sound passage portion 150.

The present invention has been conceived in view of the background thus far described and its object is to provide an alarm apparatus capable of preventing liquid from entering into a case.

According to the present invention, a buffer member capable of buffering momentum of liquid is provided in an outlet side opening portion of the sound passage. According to this structure, even if liquidenters fromtheoutlet side opening portion of the sound passage when the liquid is splashed over the surface side of the case, the entered liquid collides with the buffer member to reduce its speed and to weaken its momentum. As a result, even if the liquid enters into the inside of the sound passage due to splashing, it can prevent the liquid from further entering into the case through the sound passage.

According to another aspect of the present invention, a case has drain means for facilitating drain liquid causing in the sound passage. In this case, the liquid entered into the sound passage tends to be temporally accumulated in the drain means and immediately drained externally. As a result, even if the liquid enters into the inside of the sound passage due to splashing, it can prevent the liquid from further entering into the case through the sound passage.

According to still another aspect of the present invention, a buffer wall extending to inside of the sound passage is provided in an outlet side opening portion of the sound passage which is opened to a surface of the case, a depression portion formed by depressing a bottom surface of the sound passage is provided on the way in the sound passage, and the depression portion provided along an extending direction of the buffer wall. According to this structure, even if water enters from the outlet side opening portion of the sound passage when the water is splashed over the surface side of the case, the entered water collides with the buffer wall to reduce its speed and to weaken its momentum. Furthermore, the depression portion is provided along the extending direction of the buffer wall on the way in the sound. Therefore, since the entered water collides with the buffer wall to weaken its momentum, the water entered into the sound passage tends to be temporally accumulated in the depression portion and immediately drained externally. As a result, even if the water enters into the inside of the sound passage due to splashing, it can prevent the water from further entering into the case than the sound passage.

Furthermore, volume of the outlet side opening portion decreases as a result of providing the buffer wall in the outlet side opening portion of the sound passage, however, influence to the alarm sound such as sound pressure decreasing can be prevented to as small as possible, because a decreased volume can be compensated by providing the depression portion on the way in the sound passage.

These and another objects, features and characteristics of the present invention will be appreciated from a study of the following detailed description, the appended claims, and drawings, all of which form parts of this application. In the drawings, same portions or corresponding portions are put the same numerals each other to eliminate redundant explanation. In the drawings: FIG. 1A is a plan view for illustrating inside of an alarm apparatus; FIG. 1B is a sectional view of the alarm apparatus taken along a line IB-IB in FIG. 1A ; FIG. 2 is a plan view of the alarm apparatus seen from a main surface side of a case (with case); FIG. 3 is a plan view of the alarm apparatus seen from the main surface side of the case (without case); and FIG. 4 is a sectional view of a conventional alarm apparatus according to a related art.

EMBODIMENT Next, an embodiment of the present invention will be explained with reference to the drawings.

FIG. 1A is a plan view for illustrating inside of an alarm apparatus, and FIG. 1B is a sectional view of the alarm apparatus (sectional view taken along a line IB-IB).

An alarm apparatus 1 of this embodiment is constructed by a sounding body 2 as a sound source, a signal processing circuit portion 3 for performing a signal processing to have the sounding body 2 generate alarm sound, a backup battery 4 as a power when the alarm sound is generated, a case 5 (described later) for containing these components, and so on.

The sounding body 2 is f abricated by enclos ing peripheries of a piezoelectric element (PZT) with a vibration plate made of brass or the like. The peripheral portion of the vibration plate of the sounding body 2 is pressed into an outer frame 5a provided in the case 5. The sounding body 2 is fixed by being pressed by a supporting member 6, which is inserted into the outer frame 5a of the case 5, from a back of the sounding body 2.

In the signal processing circuit portion 3, a connector 8 provided on a substrate 7 is electrically connected with the sounding body 2 via a lead wire 9, and the substrate is fixed to the case 5 side by screw 10.

As shown in FIG. 1B, the backup battery 4 is covered with a division member 11, and is divided into one portion where the sounding body 2 is located and another portion corresponding to the signal processing circuit portion 3 by the division member 11 in the case 5.

The division member 11 is fixed by inserting a plurality of hook portions l la provided at periphery into hole portions opened at the substrate 7 of the signal processing circuit portion 3.

It should be noted that a predetermined gap is secured between the divisional member 11 covering the backup battery 4 and the supporting member 6 so as to eliminate an influence (change of timbre) of the signal processing circuit portion 3 to the sounding body 2 when the alarm is needed.

The case 5 is made up of a lower case 5A, an upper case 5B and a cover case 5C, each of which is made of thermosetting resin such as PBT, PPS, or the like.

As shown in FIG. 1B, the lower case 5A forms a bottom surface of the alarm apparatus, which contacts with a mounting surface of the vehicle side, and constitutes a casing body for containing the above-described sounding body 2, the signal processing circuit portion 3, backup battery 4, or the like, by being combined with the upper case 5B.

The upper case 5B covers a main surface side of the alarm apparatus 1, and forms a sound passage (described later) for externally emitting sound generated by the sounding body 2 with the cover case 5C. A cylindrical wall portion 12 positioned at substantially center portion of the sounding body 2 and a circular concave 13 (see FIG. 1B) provided so as to surround an outer periphery of the cylindrical wall portion 12 are provided at a main surface side of the upper case 5B.

As shown in FIG. 1A, a connector portion 14 for communicating electric signals between the alarm apparatus 1 and an external ECU (computer) controlling a not-shown security system (anti-theft system), and a mounting portion 15 for mounting the alarm apparatus 1 on a bracket (not-shown) of the vehicle side by being inserted thereto, are integrally constructed at a peripheral portion of the upper case 5B.

The cover case 5C has a circular shape (see FIG. 2) in a flat plane and a concavo-convex shape in section in a radial direction (see FIG. 1B), and arranged so as to secure gap that defines the sound passage at the concave 13 circularly provided to the upper case 5B.

As shown in FIG. 1B, the sound passage includes a central sound passage portion 16, which opens at a substantially center portion against the sounding body 2, and a peripheral sound passage portion 17, which is meanderingly provided in an S-shape from the central sound passage portion 16 to external. An outlet of the peripheral sound passage portion 17 is opened to a surface of the case 5 (see FIG. 2).

The central sound passage portion 16 is made up of the cylindrical wall provided to the upper case 5B, and gradually enlarged from the sounding body 2 side to the main surface side of the case 5.

The peripheral sound passage portion 17 is fabricated bycombiningtheuppercase5Bandthecovercase 5C, andconcentricity arranged with respect to the central sound passage portion 16.

Furthermore, the peripheral sound passage portion 17 has two meandering portions (turning-back portions) having substantially U-shape between an inlet leading to the central sound passage portion 16 and the outlet opening to the surface of the case 5. In addition, the peripheral sound passage portion 17 has a shape so that its passage section area gradually increases from the inlet to the outlet. Particularly, an outlet side opening portion thereof is enlarged in a funnel-shape.

A buffer wall 18 extending to inside of the peripheral sound passage portion 17 is provided in the outlet side opening portion 17a of the peripheral sound passage portion 17 opening to the surface of the case 5. Furthermore, a first depression portion 19 and a second depression portion 20, each of which is formed by depressing a bottom surface of the peripheral sound passage portion 17, are provided on the way in the peripheral sound passage portion 17.

In other words, the buffer wall 18 obliquely arranged in the peripheral sound passage portion 17 with respect to an extending direction of the peripheral sound passage portion 17 at an outlet side opening portion 17a. The buffer wall 18 is for buffering momentum of fluid such as water.

Thebufferwall 18 is formed inaring-shape, andpositions at substantially center portion between an outer surface of the cover case 5C forming the outlet side opening portion 17a of the peripheral sound passage portion 17 and an inner surface of the upper case 5B, and is integrally formed with the cover case 5C via a plurality of ribs 21 as shown in FIG. 2. Each of the rib 21 connects the cover case 5C and the buffer wall 18 in the radial direction, and has an outer edge portion extending to outer side of the buffer wall 18, and is hooked to a hooking groove 22 (see FIG. 3) provided at the inner surface of the upper case 5B.

As shown in FIG. 3, the first depression portion 19 and the second depression portion 20 are individually provided at both outer side and inner side of the circular concave 13 of the upper case 5B so as to be concentrically formed with respect to the cylindrical wall portion 12. Concretely, the first depression portion 19 is provided along an extending direction of the buffer wall 18, and the second depression portion 20 is provided along the outer surface of the cylindrical wall portion 12. Furthermore, the first depression portion 19 and the second depression portion 20 are communicated with each other through a plurality of communication passages 23 in a radial direction.

Next, operations and effects of this embodiment will be explained.

In the alarm apparatus 1 to be mounted on the vehicle, because the outlet of the peripheral sound passage portion 17 is opened to the surface of the case 5, if water is splashed over the alarm apparatus 1 due to rain or car-washing, there is a possibility that the water enters into inside of the peripheral sound passage portion 17 through the outlet of the peripheral sound passage portion 17. On the contrary, according to the alarm apparatus of this embodiment, the buffer wall 18 is provided in the outlet side opening portion 17a of the peripheral sound passage portion 17. Therefore, the entered water collides with the buffer wall 18 to reduce its speed and to weaken its momentum, even if the water enters from the outlet of the peripheral sound passage portion 17.

Furthermore, the first depression portion 19 is provided along the extending direction of the buffer wall 18 on the way in the peripheral sound passageportion 17, and the second depress ion portion 20 is provided at inner side with respect to the first depression portion 19. Therefore, since the entered water collides with the buffer wall 18 to weaken its momentum, the water entered into the peripheral sound passage portion 17 tends to be temporally accumulated in the first depression portion 19 or the second depression portion 20 and immediately drained externally. As a result, it can prevent the water from entering into inside of the casing body through the peripheral sound passage portion 17 and further the central sound passage portion 16, even if the water enters into the inside of the peripheral sound passage portion 17 due to splashing.

Furthermore, volume of the outlet side opening portion 17a decreases as a result of providing the buffer wall 18 in the outlet side opening portion 17a of the peripheral sound passage portion 17, however, influence to the alarm sound such as sound pressure decreasing can be prevented to as small as possible, because a decreased volume can be compensated by providing the first depression portion 19 on the way in the peripheral sound passage portion 17.

Particularly, whenthealarmapparatus 1 ismoredownsized and thinned, a pas sage length of the peripheral sound pas sage port ion 17 becomes necessarily short and the number of turning-back also necessarily reduces. Therefore, there is a high possibility that the water entering from the peripheral sound passage portion 17 further enters into the inside of the casing body through the central sound passage portion 16 when the water is splashed over the alarm apparatus 1. Therefore, in the case where the number of the turning-back of the peripheral sound passage portion 17 becomes to or less than two (two in this embodiment) as a result of downsizing and thinning of the alarm apparatus 1, it is sufficiently effective to prevent water from entering into inside of the casing body by providing the buffer wall 18 in the outlet side opening portion 17a of the peripheral sound passage portion 17 and by forming the first depression portion 19 and the second depression portion 20 by depressing the bottom surface of the peripheral sound passage portion 17.

In this embodiment, the peripheral sound passage portion 17 is concentricity provided with respect to the central sound passage portion 16, and the buffer wall 18 and the depression portion 20 are circularly formed along entire surrounding portion of the peripheral sound passage portion 17. As a result, it can prevent the water from entering into the case independent of direction of splashing.

(Modification) In the above-described embodiment, a buffer member is exemplified by the buffer wall 18, however, a mesh provided at inside of the peripheral sound passage portion 17 or at outlet side opening portion 17a may be applied as the buffer member, so that the water collides with the mesh to reduce its speed and to weaken its momentum.

In the above-described embodiment, the second depression portion 20 is provided at inner side than the first depression portion 19. However, it is not necessary to provide the second depression portion 20, and it can be expected to achieve an effect that it can prevent the water from entering into inside of the casing body by only the buffer wall 18 and the first depression portion 19. However, it can enhance the effect of which it can prevent the water from entering into the case, by providing this second depression portion 20.

According to this embodiment, it is preferable to provide the depression portion 20 at the upper case so as to receive the water entered from the sound passage. Furthermore, it is preferable to provide the buffer wall 18 at least one of the upper case and the cover case. Furthermore, the buffer wall 18 may be integrally formed with the upper case 5B instead of the cover case 5C.

Claims

1. An alarm apparatus comprising: a sounding body for generating sound; a case for containing the sounding body, and for defining a sound passage for emitting sound generated by the sounding body; and a buffer member provided in an outlet s ide opening portion of the sound passage, and being capable of buffering momentum of liquid.

2. An alarm apparatus according to claim 1, wherein: the buffer member includes a buffer wall extending to inside of the sound passage provided in an outlet side opening portion of the sound passage which is opened to a surface of the case.

3. An alarm apparatus according to claim 1, wherein: the buffer member includes a buffer wall obliquely arranged in the sound passage with respect to an extending direction of sound passage at an outlet side opening portion of the sound passage which is opened to a surface of the case.

4. An alarm apparatus according to claim 1, wherein: the buffer member includes a mesh member arranged in the sound passage.

5. An alarm apparatus according to any one of claims 1 to 4, wherein: the sound passage includes a central sound passage portion opening to substantially center portion with respect to the sounding body and a peripheral sound passage portion meanderingly provided in an S-shape from the central sound passage portion to a periphery, the peripheral sound passage portion includes one or more turning-back portions having a substantially U-shape between the central sound passage portion and the outlet side opening portion which opens to the surface of the case, and the number of the turning-back portion is to or less than two.

6. An alarm apparatus according to any one of claims 1 to 5, wherein: the case includes a depression portion formed by depressing a bottom surface of the sound passage provided on the way in the sound passage, and the depression portion provided along an extending direction of the buffer member.

7. An alarm apparatus according to claim 6, wherein: the peripheral sound passage portion is concentricity provided with respect to the central sound passage portion, and the buffer member and the depression portion are circularly formed along entire surrounding portion of the peripheral sound passage portion.

8. An alarm apparatus according to any one of claims 1 to 7, wherein: the case includes an upper case for containing therein the sounding body, and a cover case assembled at outer side of the upper case and for defining the sound passage with the upper case, and the depression portion is provided at the upper case, and the buffer member is provided at one of the upper case and the cover case.

9. An alarm apparatus according to claim 8, wherein: the upper case is provided with a second depres sion portion, which is formed by depressing a bottom surface of the peripheral sound passage portion, is provided at inside of the depression portion where is outside of the central sound passage portion.

10. An alarm apparatus comprising: a sounding body as a sound source; and a case for containing the sounding body, for defining a sound passage for emitting sound generated by the sounding body, and having drain means for facilitating drain liquid causing in the sound passage.

11. An alarm apparatus according to claim 10, wherein: the drain means includes a depression portion formed by depressing a bottom surface of the sound passage provided on the way in the sound passage, and the depression portion is provided along an extending direction of the buffer wall.

12. An alarm apparatus according to claim 11, wherein: the case includes a buffer wall extending to inside of the sound passage is provided in an outlet side opening portion of the sound passage which is opened to a surface of the case.

13. An alarm apparatus according to claim 12, wherein: the sound passage includes a central sound passage portion opening to substantially center portion with respect to the sounding body and a peripheral sound passage portion meanderingly provided in an S-shape from the central sound passage portion to a periphery, the peripheral sound passage portion includes one or more turning-back portions having a substantially U-shape between the central sound passage portion and the outlet side opening portion which opens to the surface of the case, and the number of the turning-back portion is to or less than two.

14. An alarm apparatus according to claim 13, wherein: the peripheral sound passage portion is concentricity provided with respect to the central sound passage portion, and the buffer wall and the depression portion are circularly formed along entire surrounding portion of the peripheral sound passage portion.

15. An alarm apparatus according to any one of claims 12 to 14, wherein: the case includes an upper case for containing therein the sounding body, and a cover case assembled at outer side of the upper case and for defining the sound passage with the upper case, and the depression portion is provided at the upper case, and the buffer wall is provided at one of the upper case and the cover case.

16. An alarm apparatus according to claim 15, wherein: the upper case is provided with a second depression portion, which is formed by depressing a bottom surface of the peripheral sound passage portion, is provided at inside of the depression portion where is outside of the central sound passage portion.

17. An alarm apparatus comprising: a sounding body as a sound source; and a case for containing the sounding body, and for defining a sound passage for emitting sound generated by the sounding body, wherein: a buffer wall extending to inside of the sound passage is provided in an outlet side opening portion of the sound passage which is opened to a surface of the case, a depression portion formed by depressing a bottom surface of the sound passage is provided on the way in the sound passage, and the depression portion provided along an extending direction of the buffer wall.

18. An alarm apparatus substantially as described herein with reference to Figs 1 to 3 of the accompanying drawings.