JP2006335234A - Impact sensing type current shutting off device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an impact sensing type current shutting off device with high sensitivity in which a structure is extremely simple and dusts are hardly deposited. <P>SOLUTION: The impact sensing type current shutting off device comprises an impact sensing part (10) of an axial symmetric structure in which first and second terminal parts (11, 12) having relatively small mass and an inertia motion element (10A) having relatively large mass are integrally molded on an axis through two indentation parts (breaking part P and bending fulcrum Q) having different thickness; and a body vessel (20) covering the impact sensing part (10). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a safety device for effectively preventing a vehicle fire caused by an ignition caused by a short circuit of an electric system or the like in a car collision accident.

  In automobiles, electrical wiring using a battery (storage battery) and a generator as a power source is stretched around the interior of the vehicle, so impact caused by a collision of the automobile causes a short circuit in the electrical wiring. And most of the causes of vehicle fires due to automobile collision accidents are thought to be due to ignition due to this wire short circuit. Ignition may occur in a short time after a collision or it may occur after several hours and is case by case.

  For example, it is said that when a car accident occurs and an accident vehicle has to be towed, an accident handler must first remove the battery from the accident vehicle. This is because there has been reported an accident in which a vehicle fire occurs after a few hours if this is neglected. In addition, when looking at actual car crash cases, the driver may lose consciousness due to the impact of the accident. If the accelerator is pressed for some reason, the accident vehicle will run away and cause a secondary disaster. It becomes.

  On the other hand, automobile manufacturers currently use many non-combustible materials in various parts of the vehicle to prevent vehicle fire accidents, but it cannot be said to be a fundamental solution. The electric system of automobiles is equipped with a fuse that senses overcurrent and cuts off the continuity. However, in many cases, it takes several seconds to several tens of seconds until the fuse is blown. When a sudden current load due to an accident occurs, the fuel or the like may be ignited earlier than the time until the fuse is blown, and as a result, the fire cannot be stopped.

  Therefore, a technical idea that a current interrupting device that operates by an impact is attached to a terminal of an in-vehicle battery or the vicinity thereof is disclosed (for example, refer to Patent Document 1, fifth paragraph). According to this document, the inertial force of a semi-fixed steel ball or disk-like inertial mover is used to detect an impact from the horizontal direction, and an electromagnetic circuit breaker or the like is interlocked by a switch or piezoelectric element signal. The current is cut off (see the fifth to eighth paragraphs of the same document).

JP-A-6-227335

  However, as in the structure described in Patent Document 1, the method of interrupting the current by the signal of the switch or the piezoelectric element has a complicated structure, and further, dust (dust) or the like is formed in the gap between the semi-fixed inertial motion element and the conductive wire. This is a problem in that the current interruption device itself may cause ignition in some cases when dust is easily accumulated and ignites dust.

  Further, according to the same document, it is proposed that the device is mounted at or near the battery terminal, but the battery is installed by being fixed with bolts and nuts etc. at a position independent from the vehicle body (chassis). The impact force against is not sufficiently transmitted and is easily attenuated. Therefore, it is considered that the method of attaching to the battery is disadvantageous in terms of sensitivity of impact detection.

  The present invention has been made in view of the above, and its main technical problem is to provide an impact-sensitive current interrupting device that has a very simple structure, is difficult to collect dust, and is highly sensitive.

  In order to solve the above-described problem, the impact sensing type current interrupting device according to the present invention includes a relatively small first and second terminal portions 11 and 12, and a relatively large mass inertial mover 10A. It comprises an axisymmetric impact sensing unit 10 integrally formed on one axis via two constricted portions (a tearing portion P and a bent fulcrum Q) having different thicknesses, and a main body container 20 covering the impact sensing unit 10. Features. Axisymmetric means a rotating structure obtained by rotating around one coordinate axis (for example, the z axis).

  The inertial vibrator 10A preferably has a shape in which the center of gravity is unevenly distributed closer to the constricted portion (Q) having a relatively large thickness. For example, it has a dome shape or a hemispherical structure in which a constricted portion with a small thickness (fracture portion P) is arranged at the top, and a constricted portion with a large thickness (folded fulcrum Q) is arranged on the bottom side. When an impact is applied, a relatively large inertial force is exerted on the inertial moving element 10A. However, if the center of gravity is unevenly distributed in this way, a large force tends to concentrate on a thin constricted portion (rupture portion P). This is because the response sensitivity is improved.

  The impact sensing unit 10 is preferably made of a metal having high rigidity and high conductivity, such as a copper alloy containing tungsten. This is because as the rigidity increases, the fracture portion P is surely ruptured by a certain impact or more, and as the conductivity increases, unnecessary power loss can be prevented.

  Note that the impact sensing type current interrupting device according to the present invention is used by installing the main body container 20 directly on a portion having high rigidity that forms a skeleton of the vehicle, such as a chassis portion of an automobile body. This is because the chassis part is effective to transmit the impact force applied to the car body without being attenuated. In recent years, the frame structure of the vehicle body has also diversified, and the names thereof vary from manufacturer to manufacturer, but in any case, the impact sensing type current interrupting device according to the present invention has a vehicle skeleton in the sense of increasing the sensitivity of impact sensing. It is very important that it can be directly attached to the rigid part.

  When the shape of the inertial motion part and the wall thickness of the constriction part are appropriately designed, the inertial motion element of the inertial motion part 10 is applied when a sudden external pressure is applied to the vehicle, for example, when a wall collision occurs at a speed of 20 km or more per hour. The tearing portion P of 10A is broken by the inertial force.

  According to the impact-sensing current interrupting device of the present invention, in the event of a collision, the current supply from the battery is interrupted almost simultaneously and irreversibly, preventing ignition due to a short circuit in the vehicle and stopping the engine. Therefore, the vehicle does not burn after an automobile collision.

  Embodiments of an impact sensing type current interrupting device (hereinafter simply referred to as “current interrupting device”) according to the present invention will be described below with reference to the drawings.

(Device configuration)
1 to 3 show an embodiment of a current interrupting device according to the present invention. FIG. 1 (a) is a plan view thereof, and FIG. 1 (b) is a cross-sectional view taken along line AA in FIG. 1 (a). FIG. 2 is a sectional view taken along line BB in FIG. 1A, and FIG. 3 is an overall perspective view of the apparatus.

  The current interrupting device according to the present invention is roughly composed of an inertial motion unit 10 and a main body container 20. The inertial motion unit 10 includes an inertial motion element 10 </ b> A, an upper terminal portion 11, and a lower terminal portion 12, and is attached to the chassis with bolts 21 and the like in a state of being housed in the main body container 20.

The main body container 20 is composed of a member separated into two parts, upper and lower, and is a sealed container joined by bolts or hot melt, etc., and a sealing packing such as an O-ring is provided at the joining part so that foreign matters such as moisture and dust are present. It has a structure that is difficult to invade.
FIG. 4 shows an exploded view of the main body container (a view in which the upper side of the main body container is removed). The material of the main body container is made of hard resin such as hard plastic or metal.

  FIG. 5 is a front view of the inertial motion unit 10. As shown in this figure, the inertial mover 10A is formed of a hemispherical or dome-like rigid metal body, and terminal portions 11 and 12 are integrally formed at the upper and lower portions.

  As shown in this figure, a narrowed portion P (boundary portion between the inertial moving element 10A and the upper terminal part 11) and Q point (inertia moving element 10A and lower) are located at the boundary between the inertial mover and the upper and lower terminal portions. Boundary portion with the terminal portion 12 on the side). The points P and Q are important components of the apparatus. For convenience of explanation, the point P is named “tearing part”, and the point Q is named “folded fulcrum”. The tearing part is not actually torn until an impact is sensed, and the upper terminal part 20 and the inertial moving element 10A are connected physically and electrically, but the impact is sensed. Sometimes this part is designed to tear.

  For this reason, the bending fulcrum Q is configured to be thicker than the tearing portion P. When the inertial mover 10A receives an impact from the outside, a large inertial force is exerted on the inertial mover 10A having a relatively larger mass than the surrounding members. Therefore, the upper fracture portion P is torn off with the thick bent fulcrum Q as a fulcrum. It has a structure to do. It is necessary to provide a space large enough to move the inertial vibrator 10A when the tearing portion P is torn between the main body container and the inertial moving element.

  Since the tearing portion P of the inertial moving element 10A must be broken by an impact, a member having high rigidity is preferable. In the experiment, a copper-tungsten alloy was used as the material of the inertial mover 10A. Any member may be used as long as the member has high rigidity and high conductivity. This is because if the rigidity is low, the boundary portion P is not easily torn even if an impact is applied, and if the conductivity is low, the inertial motion element itself generates heat as Joule heat, causing power loss. In addition, the magnitude | size of rigidity and the value of electrical conductivity should just be in the design tolerance. Generally, alloys containing copper and other impurities such as trace amounts of refractory metals are considered to have high rigidity and relatively low resistivity (that is, relatively high conductivity), so they can be replaced with these. Will.

  The center of gravity of the inertial mover 10A is preferably as close to the bent fulcrum Q as possible. Furthermore, since the same impact sensing force (threshold value of impact force to break) can be obtained regardless of the impact force from any direction of the entire circumference (360 degrees), the structure is preferably axisymmetric. Since the impact of an automobile accident is mostly from the horizontal direction, it is preferable to have a structure that is symmetrical in the vertical axial direction (z-axis).

  For the reasons described above, the inertial mover 10A shown in the present embodiment has a hemispherical or dome-shaped outer shape, but the inside does not necessarily have to be completely clogged, and is partially hollowed for mass adjustment. May be. Of course, it is preferable that the rotating body structure be symmetric with respect to the z-axis.

  Since this apparatus has a simple configuration in which an inertial moving element provided with a tearing portion and a bent fulcrum is covered with a main body container, the manufacturing cost is low and assembly is easy.

(installation method)
This device is connected between the positive circuit of the battery and the wiring circuit between the fuse box. That is, the connection order is (battery positive electrode) − (lower terminal portion) − (inertia mover) − (upper terminal portion) − (fuse box). In addition, even if this device is installed upside down, the operation is not affected.

  The mounting position of the device is preferably a chassis portion with high rigidity of the vehicle body. The chassis part and the main body container are connected with bolts 21. At this time, the inertial mover 10A must be connected so that the central axis connecting the upper and lower terminal portions 11 and 12 is vertical. This is because if it is attached to a portion other than the chassis, the impact will not easily propagate, and the sensing force will differ depending on the direction of impact.

  Regarding the adjustment of the impact sensing force, for example, since the airbag is designed to operate with an impact of 20 km / h or more, the inertial rupture portion (boundary portion P) and the bending fulcrum (boundary portion Q). In accordance with this, the wall thickness may be adjusted so as to be broken by an impact of 20 km / h or more. By the way, since the electric power necessary for the airbag to operate is stored in the dedicated capacitor at the time of starting the engine, the function of the airbag is not affected even if the battery current is interrupted by the operation of the impact sensing type current interrupting device of the present invention. Does not stop.

When this device is designed and mounted on a car with the above guidelines, and this device operates effectively, the impact force of a certain speed or more is detected regardless of the direction of external impact from any direction in the horizontal direction. Part P) is disconnected and the current is interrupted.
Thus, immediately after the collision accident occurs, the power supply from the battery is cut off, and even if incomplete connection of the electric wires occurs in any part of the vehicle, no short circuit occurs and no fire occurs.

  In addition, since the current supply to the engine is also cut off, even if the accelerator pedal is pressed after the occurrence of a collision accident, the engine is stopped, so that a secondary disaster due to runaway or the like can be prevented.

  If it is confirmed that there is no risk of ignition or runaway of the accident vehicle, and if self-running is necessary, the inertial mover of this device is skipped as an emergency measure (ie, the upper terminal portion 11 and the lower terminal) The part 12 may be directly connected by a relay wire. The connection at this time is expressed as (battery positive electrode) − (lower terminal portion) == emergency relay wire == (upper terminal portion) − (fuse box).

  In addition, even after the impact detection type current interrupting device of the present invention is activated, a weak current may remain in the sound-related equipment and computer-related equipment in the car, but these currents cause ignition even if they are short-circuited. However, there is no problem because a reverse current does not occur due to the action of a diode or the like.

  The impact sensing type current interrupting device according to the present invention has a simple structure and is reliable, and the safety of the automobile can be further improved by effectively preventing the ignition of the electric system in the event of an automobile collision. In addition, it can be applied not only to conventional fuel vehicles such as gasoline vehicles or diesel vehicles, but also to electric vehicles or hybrid vehicles that have become widespread in recent years. Therefore, the industrial applicability of the present invention is extremely large.

Fig.1 (a) is a top view of the electric current interruption apparatus which concerns on this invention, FIG.1 (b) is the sectional view on the AA line in (a). FIG. 2 is a cross-sectional view taken along line BB in FIG. FIG. 3 is an overall perspective view of the current interrupting device according to the present invention. FIG. 4 is an exploded perspective view showing a state where the upper side of the main body container of the current interrupting device according to the present invention is removed. FIG. 5 is a front view of the inertial motion unit of the current interrupt device according to the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Inertial motion part 10A Inertial motion element 11 Upper terminal part 12 Lower terminal part 20 Main body container P Rupture part (1st constriction part)
Q Folding fulcrum (second constriction)

Claims (4)

Two constricted portions (a tearing portion P and a bending fulcrum) having different thicknesses of the first and second terminal portions (11, 12) having a relatively small mass and the inertial mover (10A) having a relatively large mass. A shock-sensing current interrupter comprising: an axisymmetric impact sensing part (10) integrally formed on one axis via Q) and a main body container (20) covering the impact sensing part (10). apparatus. The impact sensing type current interrupting device according to claim 1, wherein the inertial vibrator (10A) has a shape in which a center of gravity is unevenly distributed closer to a constricted portion (Q) having a relatively large thickness. The impact sensing type current interrupting device according to claim 1, wherein the impact sensing unit (10) is made of a copper alloy containing tungsten. The impact-sensing current interrupting device according to claim 1, wherein the main body container (20) is directly installed in a highly rigid portion forming a skeleton of the vehicle.

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