JP3258619B2 - Acceleration detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an acceleration detecting device for detecting acceleration generated by an impact at the time of a vehicle collision or the like, and is used as a switch for starting a collision safety device such as an airbag of a vehicle.

[0002]

2. Description of the Related Art Conventionally, as this kind of acceleration detecting device, there has been known an acceleration detecting device disclosed in Japanese Patent Application Laid-Open No. H8-264088.

[0003] This is a first case in which a housing, a weight which is swingably supported by the housing and swings in response to the input acceleration, and which are brought into contact with each other by the swinging operation of the weight and held in the housing, are brought into a conductive state. It has first and second contact terminals, and terminal terminals that are insert-molded in the housing and connected to the first and second contact terminals.

In this conventional apparatus, the weight and the first
And the third contact terminal is disposed in a sealed interior space covered with a cover press-fitted and fixed to the housing, and the housing thus configured is fixed to a member to be mounted by a mounting bracket. It has become.

[0005]

However, in the above-mentioned conventional apparatus, since the terminal terminal penetrates the housing, the internal space sealed by the housing and the cover communicates with the outside through a gap around the terminal terminal. Might be. For this reason, external moisture or the like may enter through the gap, and in some cases, the entered moisture may cause corrosion of the first and second contact terminals.

Therefore, an object of the present invention is to improve the sealing performance of an internal space.

[0007]

The technical means taken in the present invention to solve the above-mentioned technical problems includes a through hole formed in a housing and opening around a terminal terminal;
A resin layer that is injected into the mounting bracket while the housing is housed in the mounting bracket, covers the periphery of the housing, flows into the through hole, and seals between the housing and the mounting bracket and seals the through hole; That is, it was.

[0008] According to this technical means, not only around the housing by the resin layer, but also around the terminal terminals by the resin layer flowing into the through hole. Therefore, the inside of the housing in which the first and second contact terminals and the weight are disposed is reliably shut off from the outside, and the sealing performance can be improved as compared with the related art.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIGS.
The housing 1 made of resin has a bottom wall 1a and a peripheral wall 1b, has a box shape in which one end side of the peripheral wall 1b is open, and integrally includes a connector 1d formed from the bottom wall 1b. The housing 1 has an opening 1 formed by a cover 2 welded to one end of a peripheral wall 1b by ultrasonic welding or the like.
c is closed to form the internal space 12. The weight 3 and the contact assembly 4 are disposed in the internal space 12. The corner between the upper part (the wall shown in FIG. 1) of the peripheral wall 1b of the housing 1 and the bottom wall 1a is bent toward the internal space 12 to form the mounting part 1e of the contact assembly 4. are doing.

The weight 3 has a fan shape, and the bottom wall of the housing 1 is provided by pins 5 whose both ends are supported on the sides (left and right walls in FIG. 2) of the peripheral wall 1b of the housing 1 at the apexes. It is swingably supported at a corner between the lower portion 1a and the lower portion of the peripheral wall 1b (the lower wall in FIG. 1). In addition, a resin layer 31 is integrally fixed to the weight 3 by molding, and the resin layer 31 forms an arc outer peripheral surface 3 a centered on the swing center of the weight 3. Both ends in the circumferential direction of the resin layer 31 protrude from both end surfaces in the circumferential direction of the weight 3 to form stopper portions 3a and 3b that can contact the lower portions of the bottom wall 1a and the peripheral wall 1b. Around pin 5
A spring 7 is wound via a collar 6. One end 7 a of the spring 7 is connected to the stopper 3 of the weight 3.
The other end 7 b extends along the lower wall of the housing 1 and is locked to the cover 2. Accordingly, the weight 3 is constantly urged to swing in the counterclockwise direction shown in FIG. 1 so as to be in the initial position where the stopper portion 3a and the bottom wall come into contact with each other under the urging force of the spring 7.

The contact assembly 4 includes a resin main body 41 and first and second contact terminals 42 and 43. The resin main body 41 includes a pair of upper portions of the peripheral wall 1b of the housing 1 and the housing 1. Attachment portion 1 press-fitted between locking projection 13
e, it is held by the housing 1. The locking projection 13 is formed to extend from the bottom wall 1c so as to face the upper part of the peripheral wall 1b. The first and second contact terminals 42 and 43 are integrally fixed to the resin body 41 by insert molding, respectively. The first and second contact terminals 42 and 43 have a first arm 42a, 43a and a second arm 42, one of which is bent to form a fork.
b, 43b are formed. First arms 42a, 43
a protrudes from the resin main body 41 so as to face the arc outer peripheral surface 32 of the weight 3, and the first arm portions 42 a,
First and second contacts 44 and 45 are electrically fixed to 43a so as to face each other. The first and second contact points 44 and 45 can come into contact with each other, and can slide on the arc outer peripheral surface 32 of the weight 3. The first and second contact terminals 42 and 43 enter a conductive state when the first and second contacts 44 and 45 come into contact, and enter a non-conductive state when the contact is released. The first and second contacts 44, 45
Respectively, by extending the first arm portions 42a and 43a,
It may be formed integrally with the first and second contact terminals 42 and 43. The second arms 42b and 43b protrude from the resin body 41 so as to face the cover 2, and a resistor 46 is electrically connected between the second arms 42b and 43b. Thereby, the first and second contact terminals 42, 43
Are in a conductive state via the resistor 46, and the presence or absence of a disconnection can be monitored by the presence or absence of the resistance of the resistor 46.

As shown in FIGS. 3 to 5, the first and second contact terminals 42, 43 protrude from the resin body 41 and extend outside the housing 1 through the mounting portion 1e of the housing 1. Leg portions 42c and 43c are formed. Further, the first and second terminal terminals 14 and 15 of the connector 1d are integrally fixed to the housing 1 by in-situ molding. The first and second terminal terminals 14 and 15 are formed with arms 14a and 15a extending outside the housing 1. The arms 14a, 1
5a is arranged perpendicular to the legs 42c and 43c, and the arms 14a and 15a are bent to
c and 43c are electrically connected by various weldings such as laser welding and resistance welding having relatively high mechanical strength. Thus, the conductive and non-conductive states of the first and second contact terminals 42 and 43 can be taken out from the first and second terminal terminals 14 and 15.

As shown in FIGS. 1 and 2, the resin layer 31 constituting the circular arc outer peripheral surface 3a of the weight 3 has an outer peripheral surface which is the circular arc outer peripheral surface 3a. An engaging groove 31c extending in the width direction (the left-right direction in FIG. 2) is formed. A first contact 44 can be engaged with the engagement groove 31c. In a state where the first contact 44 is engaged with the engagement groove 31c, the first contact 44 and the second contact 45 are engaged. With the first contact terminal 4
2 and the second contact terminal 43 are in a non-conductive state.

As shown in FIGS. 1 and 5, a connecting portion (connector 1) between the bottom wall 1a of the housing and the connector 1d is provided.
(a root portion of d), a through-hole 16 is formed extending in the direction of both sides of the peripheral wall 1 a of the housing 1. The through-hole 16 traverses the first and second terminal terminals 14 and 15 and exposes the first and second terminal terminals 14 and 15 outside the housing 1. 14 and 15 are opened. A pair of insertion grooves 17 extending in the same direction as the through-hole 16 is formed on the outer peripheral surface of the connection portion.

As shown in FIG. 1 and FIG.
Has a box-like shape provided with a bottom wall 8a and a peripheral wall 8b similarly to the housing 1 and having one end opened. The bottom wall 8a has a mounting flange fixed to a member to be mounted such as a body of a vehicle. 81 are provided. A notch 82 is formed in a lower portion (the lower wall in FIG. 1) of the peripheral wall 8b.

The housing 1 is accommodated in the case 8 so that the insertion groove 17 is inserted into the notch 82 of the case 8 and the connector 1 d projects outside the case 8. The housing 1 housed in the case 8 is covered with a sealing material 9 injected into the case 8. The sealing material 9 fills the space between the housing 1 and the case 8 and also flows into the through hole 16 of the housing 1 to fill around the first and second terminal terminals 14 and 15. This allows
The housing 1 is held in a case 8 and the housing 8
Internal space 12 is completely sealed. As described above, since the housing 1 is sealed with the sealing material 9 and the periphery of the terminal terminals 14 and 15 are also sealed with the sealing material 9, necessary and sufficient airtightness of the internal space 12 of the housing 1 can be secured. . The connection portions of the first and second contact terminals 42 and 43 exposed outside the housing 1 and the first and second terminal terminals 14 and 15 are set before the housing 1 is housed in the case 8. Cover with adhesive 10,
It is good to protect.

Next, the operation will be described with reference to FIGS.

FIG. 6 shows a state when no acceleration is input. The weight 3 receives the urging force of the spring 7 and
Is held at the initial position by contact of the stopper portion 3a with the bottom wall of the housing 1. The first contact 44 is engaged with the engaging groove 31b of the weight 3 and the second contact 4
Numeral 5 is in sliding contact with the circular arc outer peripheral surface 3a of the weight 3 while being deflected away from the first contact point 44. As a result, the first contact 44 and the second contact 45 are in a state where the contact is released, and the first contact terminal 42 and the second contact terminal 43 are in a non-conductive state.

In this state, when an acceleration in the direction A exceeding a predetermined value occurs, for example, at the time of a vehicle collision, the weight 3 receives this acceleration and resists the urging force of the spring 7 and the inertial force due to the mass of the weight 3. The stopper 3b of the weight 3 swings clockwise as shown in FIG. 6 until the stopper 3b of the weight 3 contacts the lower wall of the housing 1. During the swinging operation of the weight 3, as shown in FIG. 7, the first contact 44 is disengaged from the engagement groove 31c of the weight 3, and the first contact 44 is moved to the outer peripheral surface 3a of the arc of the weight 3. Start riding up. As a result, the first contact 44 is deflected so as to contact the second contact 45, the first contact 44 contacts the second contact 45, and the first contact terminal 42 and the second contact 45 come into contact with each other. The contact terminal 43 is brought into conduction. Such first and second contact terminals 4
The input of the acceleration is detected by switching from the non-conductive state to the conductive state of 2, 43.

During the swinging operation of the weight 3 from the state in which the first contact 44 and the second contact 45 are in contact with each other as shown in FIG. 7 until the weight 3 is in the state as shown in FIG. 9, FIG. As described above, the first contact point 45 completely rides on the arc outer peripheral surface 3a of the weight 3, and then slides on the arc outer peripheral surface 3a. As described above, when the first contact point 44 completely rides on the arc outer peripheral surface 3a of the weight 3, the second contact point 45 is pressed through the contact with the first contact point 44, and the arc outer peripheral surface 3a is pressed. , And the first contact point 44 thereafter comes into sliding contact with the arc outer peripheral surface 3a, so that the first contact point 44 is slid.
The contact state between the second contact point 44 and the second contact point 45 is maintained by the bending force of the second contact point 45. At this time, since the arc outer peripheral surface 3a is centered on the swing center of the weight 3, the first and second contact points are formed during the sliding contact of the first contact point 44 with the arc outer peripheral surface 3a of the weight 3. 44 and 45 are not flexed more than necessary. As described above, the contact state of the first and second contacts 44 and 45 is reliably maintained during the clockwise swinging operation of the weight 3 shown in FIG. Forty-five instant non-contact so-called chattering can be reliably prevented. or,
The arc-shaped outer peripheral surface 3a with which the first contact point 44 slides is formed by the resin layer 31.
Therefore, the resistance in the sliding contact is reduced, and the smooth operation of the weight 3 can be obtained.

Thereafter, when the acceleration in the direction A is lost, the weight 3 receives the urging force of the spring 7 and swings in the opposite direction to the above, and the stopper 3a of the weight 3 and the bottom wall of the housing 1 are moved. It returns to the initial position where it touched. As a result, the first contact point 44 is again connected to the engagement groove 31 of the weight 3.
c, the contact with the second contact 45 is released, and the first contact terminal 42 and the second contact terminal 43 become non-conductive.

[0022]

According to the present invention, a housing is provided with a through-hole opening around a terminal terminal in a housing, and a resin layer flowing into the through-hole and covering the housing is injected into a mounting bracket in which the housing is accommodated. Is held on the mounting bracket, so that the internal space of the housing in which the weight and the first and second contact terminals are disposed is completely sealed, so that the sealing performance can be improved as compared with the related art.

[Brief description of the drawings]

FIG. 1 is a sectional view of an acceleration detecting device according to the present invention.

FIG. 2 is a sectional view taken along line BB of FIG.

FIG. 3 is a front view showing a housing of the acceleration detecting device according to the present invention.

FIG. 4 is a top view of FIG. 3;

FIG. 5 is a sectional view of FIG. 3;

FIG. 6 is a diagram showing the operation of the acceleration detection device according to the present invention.

FIG. 7 is a diagram showing the operation of the acceleration detection device according to the present invention.

FIG. 8 is a diagram showing the operation of the acceleration detection device according to the present invention.

FIG. 9 is a diagram showing the operation of the acceleration detection device according to the present invention.

[Explanation of symbols]

 Reference Signs List 1 housing 3 weight 8 case 9 sealing material (resin layer) 14 first terminal terminal 15 second terminal terminal 16 through hole 42 first contact terminal 43 second contact terminal

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Koichi Fujita 1st Toyota Town, Toyota City, Aichi Pref. JP-A-6-135297 (JP, A) JP-A-9-306311 (JP, A) JP-A-8-235980 (JP, A) JP-A-8-264088 (JP, A) JP-A-3-55567 (JP, U) JP-A-2-92631 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01P 15/135 B60R 21/32 G01P 15/00 H01H 35/14

Claims (1)

(57) [Claims] 1. A housing, a weight supported in a swingable manner in the housing and swinging in response to an input acceleration, and contacted with each other by the swinging movement of the weight held in the housing to conduct. First and second contact terminals in a state, terminal terminals insert-molded in the housing and connected to the first and second contact terminals, and mounting fixed to the member to be mounted by housing the housing. In an acceleration sensing device having a bracket, a through hole formed in the housing and opening around the terminal terminal, and the housing is housed in the mounting bracket and injected into the mounting bracket to cover around the housing. A resin that flows into the through hole and seals between the housing and the mounting bracket and seals the through hole. And an acceleration detecting device having a layer.