JPS6119939B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an accelerometer for recording acceleration when an object collides with an object, and in particular, an accelerometer that is fixed to a part of a vehicle such as an automobile so as to record acceleration when the vehicle encounters a collision. This invention relates to an accelerometer suitable for recording whether a collision has occurred.

Conventionally, as this type of acceleration recorder, for example, there is a "recorder for acceleration at the time of collision" disclosed in Utility Model Application Publication No. 1079 of 1972, but this recorder does not have a weight that senses acceleration. It is configured to record acceleration at the time of a collision on a recording paint layer by means of a recording needle attached to a linear spring that supports a weight in a cantilever manner. In a recorder configured in this way, the detected acceleration varies greatly depending on the error in the fixed position of the weight with respect to the linear spring, so if there is an error in the fixed position of the weight during manufacturing, the desired recording characteristics may not be achieved. I can't get it. This means that
When mass-producing this type of accelerometer, it tends to be difficult to find a reliable method of fixing the weight and the wire spring and the accuracy of the fixing position, which means that it is not suitable for mass production.

In order to deal with such problems, the present invention has been developed to assemble a weight that senses acceleration to a cantilevered linear spring so that it can move without being fixed to it, and to simplify the manufacturing process in terms of relative assembly accuracy between the two. It is an object of this invention to provide an accelerometer that can be uniformly increased with a unique configuration.

An embodiment thereof will be described below with reference to the drawings. As shown in FIGS. 1 and 2, a case 10 constituting the accelerometer of the present invention has a toothed washer 12 on its male threaded portion 11. It is fixed to part B of the vehicle body by a hexagonal nut 13 tightened through the hexagonal nut 13.
A bush 21 to which one end of a wire spring 20 made of a steel wire such as a piano wire is fixed is press-fitted to the center of the bottom of the case 10, and a circular weight 30 moves in the radial direction inside the case 10. It is stored freely. The weight 30 has a tapered hole 31 at its center that expands downward.
The linear spring 20 penetrates through the smallest inner diameter portion 32 of the spring 1 and projects upward. Note that there is a small amount of play between the wire spring 20 and the minimum inner diameter portion 32 of the tapered hole 31, and due to this play, when the weight 30 moves due to inertia during the impact applied thereto, the wire spring 20 can be smoothly curved using its lower end as a fulcrum. The annular guide plate 40 is molded from synthetic resin, and is assembled by positioning and fixing its outer circumferential edge at a step 14 formed on the inner circumferential wall of the case 10. It guides you freely.

The hemispherical foil membrane member 50 is formed of a thin metal plate such as aluminum foil or copper foil, and is assembled so as to cover the linear spring 20 with its outer peripheral edge fixed to the upper surface of the guide plate 40. A recess 51 for accommodating the protruding end of the wire spring 20 is formed in the center of the foil membrane member 50, and around this recess 51, the wire spring 20 absorbs inertia at the time of impact applied to the weight 30. A hemispherical inner surface 52 is provided which is scratched by the protruding end of the filament spring 20 when bent. Also,
On the upper surface of the foil film member 50, as shown in FIG. 2, there are three scales G ₁ ,
G ₂ and G ₃ are displayed concentrically, preferably in different colors. The lid body 60 is formed into a dome shape from transparent synthetic resin, and its outer periphery is attached to the outer periphery of the foil film member 50, and the upper edge of the case 10 is caulked inward to be fixed irremovably. There is. In this way, the lid 60 covers the foil membrane member 50 through the gap, allowing the foil membrane member 50 to be deformed by being scratched by the protruding end of the linear spring 20. In addition, the lid body 6
Marks F and R are displayed on the top surface of 0 to specify the mounting direction.

A plurality of accelerometers configured as described above are used by fixing them at appropriate locations on the vehicle body (for example, locations that are relatively unlikely to be destroyed in the event of a vehicle collision), and if a collision occurs during use, Inertia corresponding to the partial acceleration of the vehicle body at the time of the collision is applied to the weight 30, and as a result, the weight 30 moves in the opposite direction to the direction in which the impact was received, causing the linear spring 20 to curve, and the surface of the foil membrane member 50 to bend. A scratch mark is obtained on the top by the projecting end of the wire spring 20. As a result, as shown in FIG.
After an accident, the degree and direction of acceleration received by the vehicle at the time of the collision can be read through the lid 60. By the way, during the above recording, the movement of the weight 30 causes the linear spring 20 to
When curved, the radius of curvature of the arc drawn by the protruding end of the linear spring 20 changes in accordance with the curved state, but in this embodiment, the hemispherical inner surface 52 of the foil membrane member 50 is approximated accordingly. Therefore, the above-mentioned scratch marks are reliably marked on the foil film member 50, and the records can be read. Also,
In this embodiment, since the protruding end of the linear spring 20 is housed in the recess 51 of the foil film member 50, the linear spring 20 is The protruding end is the foil membrane member 50
It simply swings within the recess 51 without scratching the inner surface of the holder. Furthermore, in carrying out this embodiment, the lid body 60 may be constructed as a magnifying lens, and in this case, the recorder can be made smaller and the recording scale can be made smaller and the recording can be easily performed. Can be read. In this embodiment, an example in which the bundle degree scale is displayed on the outer surface of the foil membrane member 50 has been described, but instead of this, an acceleration scale may be displayed on the outer surface or the inner surface of the lid 60.

3 and 4 show another embodiment of the present invention, in which a recording paint layer 150 is formed on the inner surface of the lid body 60 in place of the foil film member 50 of the above embodiment. There are certain characteristics. in this case,
A recess 61 corresponding to the recess 51 of the foil film member described above is provided at the center of the inner surface of the lid body 60, and the recording paint layer 150 is formed from the center part in consideration of the curvature of the linear spring 20 described above. It is applied thickly to the surrounding area. In addition, the acceleration scale G ₁ , G ₂ , G ₃ is
As shown in FIG. 4, three concentric circles are displayed on the top surface of the lid 60. Other configurations and functions are substantially the same as the above embodiments, so
Identical members are given the same reference numerals and their explanations will be omitted.

In summary, in the present invention, case 10
A weight 30 is housed inside the body so as to be movable in the radial direction.
is guided by a guide plate 40 and the linear spring 20 fixed to the center of the bottom of the case 10 passes through the center hole of the weight 30 with a gap to allow relative movement between the two. The main feature is that it curves smoothly in response to the movement of the weight 30, and its protruding end marks a scratch mark indicating the acceleration at the time of collision. It is possible to accurately record the acceleration at the time of a collision via the linear spring by assembling it in the case with a simple structure with high precision.This reduces assembly errors during manufacturing and makes it possible to record acceleration suitable for mass production. We can provide a meter.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view showing one embodiment of an acceleration recorder according to the present invention, FIG. 2 is a plan view of the foil membrane member shown in FIG. 1, and FIG. 3 is a longitudinal cross-sectional view showing another embodiment. , FIG. 4 is a plan view of the lid shown in FIG. 3. Explanation of symbols, 10... Case, 20... Linear spring, 30... Weight, 40... Guide plate, 50... Foil film member, 60... Lid, 150... Recording paint layer, G ₁ , G ₂ , G ₃ ... Acceleration scale.

Claims (1)

[Scope of Claims] 1. A weight of a predetermined weight stored in a case so as to be movable in the radial direction, one end fixed to the center of the bottom of the case, and the other end fixed to the center hole of the weight with a clearance. a linear spring that penetrates and protrudes; an annular guide plate whose outer peripheral edge is fixed to the inner circumferential wall of the case and whose lower surface slidably guides the upper surface of the weight; A recording device having a hemispherical inner surface that leaves a mark by being scratched by the protruding end of the linear spring when bent due to inertia during an impact applied to the weight, and having its outer peripheral edge fixed to the upper surface of the guide plate. It comprises a foil film member, and a transparent lid that covers the foil film member through a gap and has its outer peripheral edge fixed to the inner peripheral wall of the case, and the outer surface of the foil film member, the inner surface of the lid, or An accelerometer configured to read the amount of acceleration recorded on the foil or membrane member using an acceleration scale displayed on the outer surface. 2. A weight of a predetermined weight stored in a self-made material that moves in the radial direction within a case, one end of which is fixed to the center of the bottom of the case, and the other end of which penetrates and protrudes through the center hole of the weight with a gap. a linear spring, an annular guide plate whose outer peripheral edge is fixed to the inner circumferential wall of the case and whose lower surface guides the upper surface of the weight in a slidable manner; A hemispherical recording paint layer is formed on the inner surface of the housing and leaves traces when it is scratched by the protruding end of the linear spring when bent due to the inertia of the case, and its outer peripheral edge is fixed to the inner peripheral wall of the case. and a transparent lid body that covers the guide plate, and the acceleration amount recorded in the paint layer is read by an acceleration scale displayed on the inner or outer surface of the lid body. 3. The acceleration recorder according to item 1, wherein a recess for accommodating the protruding end of the linear spring is provided in the center of the inner surface of the foil film member. 4. The accelerometer according to item 2, wherein a recess for accommodating the protruding end of the linear spring is provided in the center of the inner surface of the lid. 5. The center hole of the weight is formed as a tapered hole that expands downward, and the linear spring passes through the minimum inner diameter portion with a clearance. Accelerometer.