JPH03246842A - Collision sensor - Google Patents

Abstract

PURPOSE:To obtain the proper sensor performance for a non-crush section in a crew room by specifying the relation of an electric contact closed against the magnetic force by a ball flyably inserted in a cylinder filled with air. CONSTITUTION:A magnet 2 with the initial magnetic force 4-10 G absorbing a ball 3 with the diameter 4-20mm flyably inserted at a gap (Hmum) in a cylinder 4 filled with air to one end of the cylinder 4 and an electric contact 5 closed at the flying distance (Lmm) 0.5-10mm against the magnetic force by the ball 3 are provided. H and L are set to H>=10+(11/1000)XL or H>=20+(11/2000)XL, H<=10+(1/10)XL, and H<=300. A collision sensor adequate for a crush section and a non-crush section can be obtained, and this type of the collision sensor can be used for the crush section at the front section of a vehicle or the non- crush section in a crew room.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a collision sensor, and in particular to a collision sensor that detects street occupancy and is used in trigger systems such as air hangs, which are vehicle occupant protection devices. related.

[Conventional technology]

Conventionally, as this type of collision sensor, the one shown in FIG. 3 and FIG. 4, which is a sectional view taken along the line A--A in FIG. 3, is known (see Japanese Patent Laid-Open No. 57-813).

This collision sensor 1 includes a ball 3 inserted into a cylinder 4 filled with air with a gap (HIIIll) so as to be able to fly freely, a magnet 2 that attracts the ball 3 to one end of the cylinder 4, and a magnet 2 that attracts the ball 3 to one end of the cylinder 4. The ball 3 is provided with an electric contact 5 that closes at a flight distance (L tm ) that overcomes the magnetic force of the magnet 2, and these are integrated with a resin body 6 and a holding plate 7. The cylinder 4 made of non-magnetic material forms a guide space that guides the flight of the ball 3 in the direction of the arrow. When the ball 3 flies in the direction of the arrow, it is subjected to a viscous damping effect due to the air flow passing through the gap between the cylinder 4 and the ball 3 (HuIll, the difference between the cylinder inner diameter and the ball diameter). A seal 8 is therefore provided to prevent air from bypassing between the cylinder 4 and the body 6, so that one end of the cylinder 4 is completely closed.

The magnet 2 is inserted into and fixed to the shaft 9 of the body 6. The magnetic force of the magnet 2 attracts the ball 3 of magnetic material to the closed end 10. The electrical contact 5 consists of two sets of opposing cantilevered inclined pieces 5a and 5b, and the battery 11
A voltage is applied by. When the ball 3 overcomes the magnetic force of the magnet 2 due to the speed change of the collision and flies while receiving the viscous damping effect of the air flow, the ball 3 contacts both the cantilevered inclined pieces 5a and 5b, and the electric contact 5 closes. However, the above-described conventional collision sensor 1 in which a current flows to activate the electric detonator 12 of the airbag safety device operates as follows.

The ball 3 flies in the direction of the arrow depending on the degree of speed change of the collision and reaches the electrical contact 5 to sense the collision. The sensitivity of how much speed change is detected depends on the magnetic force of the magnet 2 that attracts the ball 3, the flight distance L (mm: millimeter) between the magnet 2 and the electric contact 5, and the gap between the ball 3 and the cylinder 4. H (μm = Mira 0) is affected.

Incidentally, the collision sensor 1 in the above-mentioned Japanese Patent Application Laid-Open No. 57-813 is premised on being attached to a crushed portion at the front of a vehicle, and preferred examples of the above three elements are proposed as follows. The magnetic force of the magnet 2 is 5G or less (approximately 2G) at the attraction position of the ball 3, and I at the contact position of the ball 3 and the electric contact 5.
It should be about G.

Further, the gap H provides viscous damping to the movement of the ball 3, and is set to such an extent that the ball 3 can maintain contact with the electrical contact 5 for a considerable period of time.

Then, the flight distance is changed depending on the degree of speed change to be detected (a long flight distance is used for sensing a large speed change, and a short flight path ML is used for sensing a small speed change). I take it as a thing.

[Problem to be solved by the invention]

Collision sensors are not limited to those installed on the crushed part of the front of the car, for example, collision sensors installed on the steering wheel, etc.
There is also a collision sensor that is installed in the non-collapsible part of the passenger compartment.
The collision sensor in the above-mentioned Japanese Patent Application Laid-Open No. 57-813 is intended to be installed in the collapsed part of the front of the vehicle, and there is a problem in that the sensitivity is too low to be used in the non-collapsed part of the passenger compartment. . Furthermore, even with the collision sensor disclosed in Japanese Patent Application Laid-Open No. 5-7-8-13, which is installed on the crushed part of the front of the vehicle, if the flight distance and clearance are not appropriate, it will not be able to respond appropriately to the speed changes that should be detected. The problem was that it did not work.

The present invention has been made in view of the problems of the conventional technology, and its purpose is to apply it not only to the collapsed part at the front of the vehicle, but also to the non-collapsed part in the passenger compartment. The present invention aims to provide a collision sensor that can perform various types of collisions and has appropriate sensor performance for each type of collision.

[Means to solve the problem]

In order to achieve the above object, the collision sensor of the present invention has a gap (Hun) in the cylinder filled with air in the collision sensor installed in the non-collapsible part in the passenger compartment.
A ball with a diameter of 4 to 20 m inserted so that it can fly freely, a magnet with an initial magnetic force of 4 to 10 G that attracts the ball to one end of the cylinder, and a ball that overcomes the magnetic force and has a diameter of 0.5 to 10 mm. and an electrical contact that closes at the flight path a (Lmm), and H and L are H≧io+ (11/1000
) x L or H≧20+(11/2000) xL,
H≦lo+(1/10) X L and 1-1≦300
It is.

In the case of a collision sensor attached to the collapsed part at the front of the car, there is a gap (Hun) in the cylinder filled with air.
A ball with a diameter of 4 to 20 medullary diameter inserted so that it can fly, a magnet with an initial +M magnetic force of 2 to 4 G that attracts this ball to one end of the cylinder, and a ball that overcomes the magnetic force and has a diameter of 1 to 15 It is equipped with an electric contact that closes at the flying distance of the penguin (LM), and H and L are H≧1o+ (2/1000)
x L , H≦10+(11/1000)×L and H≦20+ (11/2000) X L.

[Effect]

As shown in FIG. 2, the required performance (change in operating speed) of the collision sensor is different between the collision sensor for the passenger compartment (non-collapsed part) and the one for the front of the vehicle (collapsed part). The operating speed change for the non-collapsible part is required to be small where the time is short and to increase with time.

Further, the operating speed change for the crushing part is required to be constant and large regardless of time. Especially pulse time 25+ms
The amount of change in operating speed at is important, and for non-collapsible parts, 2.
It is said that 5 to 3.5 mph is appropriate, and 6 to 10 mph for crushed parts. Furthermore, the degree to which the change in operating speed for the non-collapsible portion increases over time is determined by the average acceleration of collisions that require non-collapsing. Appropriate performance required for such non-collapsible parts and for crushable parts can only be achieved by applying appropriate ranges of magnetic force, gap, and flight distance to each. The present invention provides this proper range so that proper performance of the crash sensor can be obtained.

First, a description will be given of the non-collapsible part. Ball diameter is 4-2
If it exceeds 20mm, the collision sensor itself becomes large and becomes inappropriate, and if it is less than 4InI11, the gap (I
(μm) becomes difficult to set to an appropriate value. next,
The initial magnetic force of the magnet is determined by the average G of the collision required to be inoperative, and generally the average C is 4 to IOC. Next, according to Figure 1, the gap (HIIll) and the flight path # (L
M) will be explained. Gap H is 300 μm or less (■ in Figure 1)
If it exceeds 300 μm, the viscosity damping effect of air cannot be expected. Flight distance is 0.5-10mm
(■ line and ■ line in Figure 1). Since the manufacturing accuracy is about 0°1M, 0.5 mm is necessary even for non-collapsible parts where the gap accuracy does not significantly affect performance. In addition, the magnetic force of a magnet decreases as the flying distance increases, but even at the maximum flying distance, it is necessary to ensure a force to resist the G of about 0.5 G that occurs during braking, and sensitivity depends on the magnetic force. For non-collapsible parts with a large proportion, the thickness must be 10 mm or less. Furthermore, between the gap (Hus) and the flight distance (L picture), H≧10+(11/1000x L
)...(■ line in Figure 1) or H≧20+ (11/2
000) x L... (■ line in Figure 1), and if it is less than this, the sensitivity becomes too insensitive and cannot be used. Also, H
≦10+ (1/10)×L... (■ line in Figure 1), and if this is exceeded, the sensitivity is too sensitive to be used.

Next, the part for crushing part will be explained. The ball diameter is 4 to 20 mm, which is the same as that for the non-collapsible part, and if it exceeds 20 m, the collision sensor itself will become large and inappropriate, and if it is less than 4 ium, it will be difficult to set the clearance (Hus) to an appropriate value. Next, it is basically better for the initial magnetic force of the magnet to be small in order to achieve the characteristics for crushing parts, but even at the maximum flight distance, which will be explained next, the G force of about 0.5 G that occurs when braking is In order to ensure magnetic force to resist, it is 2 to 4G.

Next, in Figure 1, the flight distance is 1.0 to 15M.
(■ line and @ line in Figure 1). Manufacturing accuracy is O.1II
Since it is about II11, 1.0 mm is necessary for crushing parts where the gap accuracy greatly affects performance. Also, the magnetic force of the magnet decreases as the flight path ML increases,
0.5CJ that occurs during braking even with the maximum flight path ML
It is necessary to secure a force that can resist a certain amount of G, and for a crushing part where the proportion of sensitivity that depends on magnetic force is small, it is necessary to set the force to 15 M or less. Furthermore, between the gap (Hus) and the flight distance (L mm), H≦10+(11/1000
×L) -...([Phase] line in Figure 1) and H≦20+(
11/2000) X L... ([Phase] line in Figure 1)
If this value is exceeded, the sensitivity is too sensitive and cannot be used. Also, H≧10+ (2/1000) x L...(first
If the value is less than this, the sensitivity becomes too insensitive and cannot be used.

〔Example〕

The present invention will be explained in detail below. The basic configuration of the collision sensor is the same as that explained in FIGS. 3 and 4, and the cylinder 4 is made of austenitic stainless steel, which is a non-magnetic material, and the ball 3 is made of martensitic stainless steel, which is an I-type material. It is used. Examples 1 and 2 for the non-collapsible portion and Examples 3 and 4 for the crush portion will be described below.

Real J! dLL As a collision sensor for non-crushing parts, the diameter of the ball 3 is the maximum of 20mm, and the operating limit speed change is the minimum of 2.5mph.
When the initial magnetic force of the magnet was set to the maximum of 10 G, the relationship between the flight distance and the gap was as shown by line A in Figure 1.

The tip plate is also used as a collision sensor for non-crushable parts, with the diameter of the ball 3 being the minimum of 4 pins, and the operating limit speed change being the maximum of 3.5 m.
ph, and the initial magnetic force of the magnet was set to the minimum 4G, the relationship between the flight distance and the gap was as shown by line B in FIG.

As a collision sensor for actual F-ray crushing parts, the diameter of the ball 3 is the maximum of 20 mm, the operating limit speed change is the minimum of 6 mph, and the initial magnetic force of the magnet is the maximum of 4 G.
The relationship between flight distance and gap is shown by line C in Figure 1.

The diameter of the ball 3 is set to the minimum diameter of 4.5 mm as a collision sensor for the crushing part. mm, and the operating limit speed change is the maximum of 10 m.
ph, and the initial magnetic force of the magnet was set to the minimum 2G, the relationship between the flight distance and the gap was as shown by line D in FIG.

In FIG. 1, the A line of Example 1 is near the ■ line, and the B line of Example 2 is near the ■ cotton. Therefore, as a collision sensor for a non-collapsible part, a ball with a diameter of 4 to 20 mm and an initial magnetic force of 4 to attract this ball to one end of the cylinder are used.
- Appropriate sensor performance can be obtained if the gap and flying distance of the IOC magnet are in region A in FIG.

Moreover, the C line of Example 3 is near the ■ line, and the D line of Example 3 is
The line is near the [phase] line. Therefore, as a collision sensor for a crushed part, a ball with a diameter of 4 to 20 mm and a magnet with an initial magnetic force of 2 to 4 G that attracts the ball to one end of the cylinder are used, even if the gap and flight distance are in the area B in Figure 1. appropriate sensor performance can be obtained.

〔Effect of the invention〕

The collision sensor according to the present invention is a collision sensor installed in a non-collapsible part in the passenger compartment, and is a 4 to 20 mm diameter cylinder inserted in a cylinder filled with air with a gap (Hμm) so as to be able to fly. A ball, a magnet with an initial magnetic force of 4 to IOC that attracts the ball to one end of the cylinder, and an electric contact where the ball overcomes the magnetic force and closes with a flight path of 0.5 to 10 mm*It (Lmm). and H and L
However, H≧10+(11/1000) ×L or)I≧2
0+(11/2000) ×L, H≦10+ (1/
10) If X L and H≦300, appropriate sensor performance can be obtained.

In the case of a collision sensor attached to the crushed part at the front of the car, there is a gap (Hμm) in the cylinder filled with air.
A ball with a diameter of 4 to 20 mm is inserted so that it can fly, and a magnet with an initial magnetic force of 2 to 4 G attracts the ball to one end of the cylinder.
〜15+nn+ flight path M (La111), and H and L are H≧10 + (2/10
00) x L, H≦10+ (11/1000)
If ×L and H≦20+ (11/2000) x L, appropriate sensor performance can be obtained.

Furthermore, since it is possible to use an appropriate collision sensor for the crushing part and for the non-collapsing part, this kind of collision sensor can be used for either the crushing part in the front of the vehicle or the non-collapsing part in the passenger compartment. I can do it.

[Brief explanation of drawings]

Fig. 1 is a graph showing the relationship between the gap and flight distance of the collision sensor of the present invention, Fig. 2 is a graph showing the characteristics required of the collision sensor, Fig. 3 is a cross-sectional view of the collision sensor, and Fig. 4. 3 is a sectional view taken along line A-A in FIG. 3. 2...Magnet, 3...Ball, 4...Cylinder, 5
...Electric contact, 11...Gap, L...Flight distance.

Claims (2)

[Claims] (1) A ball with a diameter of 4 to 20 mm is inserted into a cylinder filled with air with a gap (Hμm) so that it can fly freely, and the initial magnetic force of 4 to 10 G to attract this ball to one end of the cylinder is comprising a magnet and an electric contact where the ball overcomes magnetic force and closes at a flying distance (Lmm) of 0.5 to 10 mm, and H and L are H≧10+(11/1000)
×L or H≧20+(11/2000)×L, H≦10
+(1/10)×L and H≦300, a collision sensor attached to a non-collapsible part in the passenger compartment. (2) A ball with a diameter of 4 to 20 mm is inserted into a cylinder filled with air with a gap (H μm) so that it can fly freely, and the initial magnetic force of 2 to 4 G to attract this ball to one end of the cylinder is The magnet and the ball overcome the magnetic force and
Equipped with an electrical contact that closes at a flight distance (Lmm) of ~15mm, H and L are H≧10+(2/1000)×L, H
≦10+(11/1000)×L and H≦20+(11
/2000)×L A collision sensor is attached to the crushed part at the front of the vehicle.