JP2016151477A - Pressure sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pressure sensor for detecting collisions at a plurality of places of an automobile separately.SOLUTION: A pressure sensor according to the present invention has an enclosure 7, a pressure detection element 8 disposed inside the enclosure 7, and pressure wave propagation paths 11a, 11b for propagating pressure waves Va and Vb produced as an automobile is subjected to pressure, and further includes a plurality of introduction parts for introducing the pressure waves Va and Vb into the enclosure 7 via the pressure wave propagation paths 11a, 11b, and a divided path formation unit 12 for dividing the pressure wave propagation path 11b formed in all or other than one of the plurality of introduction parts and forming a plurality of divided paths 13 and 14 differing in the propagation distance of the pressure wave Vb, a difference in the propagation distance of pressure waves between the plurality of introduction parts being mutually different.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a pressure sensor, and more particularly to a pressure sensor that detects a pressure wave generated when a vehicle is compressed.

  Conventionally, pressure sensors have been used to detect automobile collisions. Generally, a pressure sensor is configured by disposing a pressure detection element in a housing. For example, a pressure wave generated by a car colliding and being compressed is guided into the housing, and the pressure wave is detected by pressure. Detect with element. By arranging such a pressure sensor in the vicinity of the outer surface of the vehicle, it is possible to detect the collision of the vehicle in advance, for example, by quickly deploying the airbag in the vehicle by detecting the collision, It can be surely protected.

  Here, since collisions occur in various parts of the automobile, it is necessary to arrange pressure sensors at the respective parts in order to cope with these collisions, which increases the number of pressure sensors, complicates the apparatus and reduces the cost. May increase. For this reason, it is required to detect a collision at a plurality of locations of an automobile with a single pressure sensor.

  Therefore, as a technique for detecting a collision at a plurality of locations with a single pressure sensor, for example, Patent Document 1 discloses that the interior of a plurality of doors is connected to a tube integrated container via a plurality of tubes, and the internal air in the plurality of doors. A vehicle collision detection system that propagates the pressure change to the tube integrated container has been proposed. In this vehicle collision detection system, the pressure change of the internal air occurs in the tube integrated container due to the pressure change of the internal air at the plurality of doors, and this pressure change is detected by the pressure detection sensor. It is possible to detect the occurrence of a collision at a plurality of doors.

JP 2007-127537 A

  However, the vehicle collision detection system disclosed in Patent Document 1 distinguishes and detects collisions at a plurality of locations in an automobile because the internal air of the tube integrated container shows the same pressure change regardless of which door has a collision. Was difficult.

  The present invention has been made to solve such a conventional problem, and an object thereof is to provide a pressure sensor that distinguishes and detects a collision at a plurality of locations of an automobile.

  The pressure sensor according to the present invention includes a housing, a pressure detection element disposed in the housing, and a pressure wave propagation path for propagating a pressure wave generated by the automobile being compressed. A plurality of introduction portions for introducing pressure waves into the housing via a plurality, and a plurality of division passages having different propagation distances of pressure waves by dividing pressure wave propagation passages formed in all or other than the plurality of introduction portions And a difference in pressure wave propagation distance between the plurality of introduction portions.

  Here, it is preferable to provide the dividing path forming portion other than one of the plurality of introducing portions.

  Moreover, it is preferable that a division path formation part deform | transforms so that the propagation distance of a pressure wave may become long except for one of several division paths.

In addition, the plurality of introduction portions protrude from the housing to connect a plurality of propagation tubes that propagate from a plurality of locations of the automobile and propagate pressure waves, and a plurality of connections in which pressure wave propagation paths are formed inside It is preferable to provide in the part.
Further, the plurality of introduction portions can be provided in a propagation tube that extends from a plurality of locations of the automobile and is connected to the housing and has a pressure wave propagation path formed therein.

  Moreover, it is preferable to further have a valve which is disposed in the housing and allows the pressure wave to pass only from the pressure wave propagation path into the housing.

  In addition, the plurality of introduction parts are composed of a first introduction part and a second introduction part in which pressure wave propagation paths are respectively formed, and the division path formation part is a pressure wave propagation path formed in the first introduction part. Only one of the two dividing paths can be deformed so that the propagation distance of the pressure wave propagating through the two dividing paths is different.

  According to the present invention, the pressure wave propagation path formed in all or one of the plurality of introduction parts is divided to form a plurality of division paths having different propagation distances of pressure waves and between the introduction parts. Since the difference in the propagation distance of the pressure wave is different, it is possible to provide a pressure sensor that distinguishes and detects collisions at a plurality of locations of the automobile.

It is a figure which shows the structure of the collision detection apparatus provided with the pressure sensor which concerns on Embodiment 1 of this invention. It is a figure which shows the airbag apparatus arrange | positioned at the motor vehicle. It is a graph which shows intensity distribution of a pressure wave detected with a pressure sensing element. It is sectional drawing which shows the structure of the pressure sensor which concerns on Embodiment 2 of this invention. 6 is a graph showing an intensity distribution of a pressure wave detected by a pressure detection element in the second embodiment. FIG. 10 is a cross-sectional view illustrating a configuration of a pressure sensor according to a modification of the second embodiment. 6 is a graph showing an intensity distribution of a pressure wave detected by a pressure detection element in a modification of the second embodiment. It is sectional drawing which shows the structure of the pressure sensor which concerns on Embodiment 3 of this invention. It is sectional drawing which shows the structure of the pressure sensor which concerns on Embodiment 4 of this invention. It is sectional drawing which shows the structure of the pressure sensor which concerns on the modification of Embodiment 1-4.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
Embodiment 1
FIG. 1 shows the configuration of a collision detection apparatus including a pressure sensor according to Embodiment 1 of the present invention. This collision detection device has a pressure sensor 1 for detecting a pressure wave, and this pressure sensor 1 is connected to two pressure generation chambers Ra and Rb provided at different locations of an automobile via a propagation tube 2. . The pressure sensor 1 is connected to the collision calculation unit 3, and the collision calculation unit 3 is connected to the airbag control unit 4. Further, the airbag control unit 4 is connected to the two airbag devices 5a and 5b.
The pressure generating chambers Ra and Rb generate pressure waves Va and Vb when the automobile collides and is compressed, and can be provided, for example, inside the center pillar and the rear door of the automobile.

  The propagation tube 2 has a cylindrical shape, one end of which is connected to the pressure generating chambers R1 and R2 and the other end is connected to the pressure sensor 1, and the inside thereof is a hollow extending from one end to the other end. A pressure wave propagation path 6 is formed. The pressure wave propagation path 6 propagates the pressure waves Va and Vb generated when the pressure generating chambers Ra and Rb are compressed to the pressure sensor 1, and a propagation fluid that propagates the pressure waves Va and Vb, for example, air Is filled with.

The pressure sensor 1 includes a housing 7 in which a pressure detection chamber D is formed, and a pressure detection element 8 disposed in the pressure detection chamber D of the housing 7.
The housing 7 is provided with two connecting portions 9a and 9b that protrude outward from the side walls facing each other. The connecting portions 9a and 9b are for connecting the propagation tube 2 to the housing 7 and have a cylindrical shape, and a helical uneven portion 10 is formed on the outer peripheral portion thereof. By inserting the connecting portions 9a and 9b into the propagation tube 2, the uneven portion 10 is press-fitted into the inner wall of the propagation tube 2, and the propagation tube 2 is connected to the connecting portions 9a and 9b.
In addition, the connection parts 9a and 9b comprise the introduction part in this invention.

  Pressure wave propagation paths 11a and 11b communicating with the pressure wave propagation path 6 of the propagation tube 2 and extending linearly to the pressure detection chamber D are formed inside the connection portions 9a and 9b. The pressure wave propagation path 11a formed in the connection portion 9a is formed to extend to the pressure detection chamber D with the same diameter. On the other hand, the pressure wave propagation path 11b formed in the connection part 9b divides the pressure wave propagation path 11b to form two division paths 13 and 14 having different propagation distances of the pressure wave Vb. Is provided.

  Specifically, the dividing path forming unit 12 projects a dividing wall 15 that divides the pressure wave propagation path 11b into two dividing paths 13 and 14, and a protrusion that projects into the dividing path 14 and changes the propagation direction of the pressure wave Vb. Part 16. The dividing wall 15 extends in a direction along the pressure wave propagation path 11b and is formed so as to divide the pressure wave propagation path 11b in half. The protrusions 16 are provided so as to alternately protrude from the inner walls facing each other in the direction in which the pressure wave propagation path 11b extends so that the pressure wave Vb meanders and propagates. As a result, the pressure wave Vb propagating through the division path 13 propagates linearly along the pressure wave propagation path 11b, whereas the pressure wave Vb propagating through the division path 14 propagates while meandering. The pressure wave Vb propagating through the pressure propagates a longer distance than the pressure wave Vb propagating through the dividing path 13.

  As described above, the difference in the propagation distance of the pressure wave Vb propagating through the pressure wave propagation path 11b is caused by the division paths 13 and 14, whereas the propagation of the pressure wave Va propagating through the pressure wave propagation path 11a. There is no difference in distance because no dividing path is formed. That is, by forming the dividing paths 13 and 14, the difference in the propagation distance of the pressure wave Vb propagating through the pressure wave propagation path 11b becomes the difference in the propagation distance of the pressure wave Va propagating through the pressure wave propagation path 11a (zero). And will be different.

The pressure detection element 8 detects the intensity of the pressure waves Va and Vb propagated through the pressure wave propagation paths 11a and 11b of the connecting portions 9a and 9b. For example, an element using a diaphragm can be used.
The collision calculation unit 3 is connected to the pressure detection element 8, and based on the intensity distribution of the pressure wave detected by the pressure detection element 8, the pressure wave is generated in either of the pressure generation chambers Ra and Rb of the automobile. Calculate whether it occurred, and identify the collision position of the car.

The airbag control unit 4 performs drive control of the airbag devices 5 a and 5 b based on the vehicle collision position calculated by the collision calculation unit 3.
The airbag apparatuses 5a and 5b are arranged at different locations in the automobile. For example, as shown in FIG. 2, the airbag apparatus 5a is arranged corresponding to the front seat of the automobile M and the rear seat of the automobile M. The airbag device 5b can be arranged corresponding to the above. Airbag devices 5a and 5b have inflators 17a and 17b, and curtain airbags 18a and 18b that are deployed in a curtain shape between a door and a passenger by injecting deployment gas from inflators 17a and 17b.

  The pressure generating chambers Ra and Rb are arranged corresponding to the locations where the airbag devices 5a and 5b are arranged. For example, the pressure generating chamber Ra is arranged in the center pillar P adjacent to the front door S1. The pressure generation chamber Rb can be disposed in the rear door S2. Thus, the airbag control unit 4 drives the airbag device 5a when the pressure wave Va is generated in the pressure generation chamber Ra, and the airbag device 5b when the pressure wave Vb is generated in the pressure generation chamber Rb. By driving the occupant, the passenger can be reliably protected according to the collision location of the automobile M.

Next, the pressure waves Va and Vb detected by the pressure detection element 8 will be described in detail.
The pressure wave Va is generated when the pressure generation chamber Ra is compressed by the collision of the automobile M, and the pressure wave Vb is generated by the pressure generation chamber Rb being compressed by the collision of the automobile M. The pressure wave Va generated in the pressure generating chamber Ra is propagated to the connecting portion 9a through the pressure wave propagation path 6 of the propagation tube 2, and propagates linearly through the pressure wave propagation path 11a of the connecting portion 9a to detect pressure. It is introduced into the chamber D and is sequentially detected by the pressure detection element 8. For this reason, as shown in FIG. 3A, the intensity distribution of the pressure wave Va detected by the pressure detecting element 8 gradually increases from the detection start time T0, and the maximum value is obtained at the detection time T1. Thereafter, the shape gradually decreases in strength.

On the other hand, the pressure wave Vb generated in the pressure generating chamber Rb is propagated to the connection portion 9b via the pressure wave propagation path 6 of the propagation tube 2, and the pressure wave propagation path 11b of the connection portion 9b is divided into the division path 13 and the division path. 14 is separated and introduced into the pressure detection chamber D. At this time, similarly to the pressure wave Va, the pressure wave Vb passing through the dividing path 13 propagates linearly through the dividing path 13 and is introduced into the pressure detection chamber D. On the other hand, the propagation direction of the pressure wave Vb passing through the dividing path 14 is changed by the protrusion 16, propagates while meandering toward the pressure detection chamber D, and is introduced into the pressure detection chamber D.
Thus, since the pressure wave Vb propagated through the dividing path 14 propagates a longer distance than the pressure wave Vb propagated through the dividing path 13, the pressure detecting element is delayed from the pressure wave Vb propagated through the dividing path 13. 8 is detected. Therefore, as shown in FIG. 3B, the intensity distribution of the pressure wave Vb detected by the pressure detection element 8 is the first maximum value at the detection time T1 due to the pressure wave Vb propagated through the dividing path 13. Then, the second maximum value is obtained at the detection time T2 due to the pressure wave Vb propagated through the dividing path 14.

Next, the operation of the first embodiment will be described.
First, for example, when a colliding body collides with the rear door S2 of the automobile M, the pressure generating chamber Rb provided in the rear door S2 is compressed to generate a pressure wave Vb. The pressure wave Vb generated in the pressure generation chamber Rb is propagated to the connection portion 9b via the propagation tube 2, and propagates separately through the pressure wave propagation path 11b of the connection portion 9b into the division path 13 and the division path 14 to form a housing. It is introduced into the pressure detection chamber D in the body 7.

  At this time, the pressure wave Vb passing through the dividing path 13 is linearly propagated toward the pressure detection chamber D, whereas the propagation direction of the pressure wave Vb passing through the dividing path 14 is changed by the dividing path forming unit 12. And propagated so as to meander toward the pressure detection chamber D. As described above, since there is a difference in the propagation distance of the pressure wave Vb propagating through the pressure wave propagation path 11b, the pressure wave Vb detected by the pressure detection element 8 is detected as shown in FIG. It will show an intensity distribution with two maxima at times T1 and T2.

The intensity of the pressure wave Vb detected by the pressure detection element 8 is sequentially output to the collision calculation unit 3, and the collision calculation unit 3 calculates the collision location of the automobile M based on the intensity distribution of the pressure wave Vb.
Here, when a collision object collides with the center pillar P of the automobile M and a pressure wave Va is generated in the pressure generation chamber Ra, the pressure wave Va is uniform along the pressure wave propagation path 11a to the pressure detection chamber D. Therefore, there is no difference in the propagation distance of the pressure wave Va. For this reason, the pressure wave Va reaches the pressure detecting element 8 at once, and an intensity distribution having one maximum value is obtained as shown in FIG. Thus, the difference in the propagation distance of the pressure wave Vb propagating through the pressure wave propagation path 11b of the connection portion 9b is different from the difference in the propagation distance of the pressure wave Va propagating through the pressure wave propagation path 11a of the connection portion 9a. The intensity distribution of the pressure wave Vb is different from the intensity distribution of the pressure wave Va.
Thus, the collision calculation unit 3 can calculate the collision location of the automobile M based on, for example, the number of local maximum values of the intensity distribution. As described above, the pressure sensor 1 distinguishes and detects a collision at a plurality of locations of the automobile M, so that the collision can be easily specified at the rear door S2.

  The collision location of the automobile M identified by the collision calculation unit 3 is output to the airbag control unit 4, and the airbag control unit 4 drives the airbag device 5b corresponding to the rear door S2 at the collision location. As a result, the deployment gas is discharged from the inflator 17b, the curtain airbag 18b is deployed between the rear door S2 and the rear seat passenger along the inner surface of the rear door S2, and the passenger is protected from the impact that collides with the rear door S2. can do.

  According to the present embodiment, by providing the pressure wave propagation paths 11a and 11b so that the difference in the propagation distance of the pressure wave between the connection portion 9a and the connection portion 9b is different from each other, the pressure detection element 8 detects the pressure wave propagation paths. The intensity distribution of the pressure wave Va and the pressure wave Vb can be obtained in different shapes, and collisions at a plurality of locations of the automobile can be distinguished and detected.

Embodiment 2
In the first embodiment, the two connection portions 9a and 9b protruding from the housing 7 are provided. However, a plurality of connection portions may be provided, and the number of connection portions is not limited to two.
For example, as shown in FIG. 4, a connection portion 9c can be newly provided in the housing 7 of the first embodiment. The connecting portion 9c is connected to a pressure generating chamber provided at a location different from the pressure generating chambers Ra and Rb in the automobile M via a propagation tube, and has a helical concavo-convex portion 10 on its outer peripheral portion. Is formed.

  A pressure wave propagation path 11c extending to the pressure detection chamber D is formed inside the connection portion 9c. The pressure wave propagation path 11c is provided with a division path forming unit 24 that divides the pressure wave propagation path 11c and forms three division paths 21, 22, and 23 having different propagation distances of the pressure wave Vc.

  Specifically, the dividing path forming unit 24 projects into the dividing walls 25 that divide the pressure wave propagation path 11c into three dividing paths 21, 22, and 23, and the propagation directions of the pressure waves Vc protruding into the dividing paths 22 and 23. And a projecting portion 26 for changing. The protrusions 26 are provided so as to alternately protrude from the inner walls facing each other in the direction in which the pressure wave propagation path 11c extends so that the pressure waves Vc meander and propagate through the division paths 22 and 23, respectively. Here, the protrusions 26 provided in the dividing path 22 are configured with a smaller number than the protrusions 26 provided in the dividing path 23, and thereby the propagation of the pressure wave Vc propagating through the dividing path 22. The distance can be shortened compared to the propagation distance of the dividing path 23.

  In this way, by forming the dividing paths 21, 22, and 23 so that the propagation distance of the pressure wave Vc becomes longer sequentially, the pressure wave Vc generated in the pressure generation chamber of the automobile separates the dividing paths 21, 22, and 23. The pressure waves Vc propagated through the divided paths 22 and 23 with respect to the pressure wave Vc propagated through the divided path 21 are sequentially introduced into the pressure detection chamber D with a delay. For this reason, as shown in FIG. 5, the intensity distribution of the pressure wave Vc detected by the pressure detection element 8 has the first maximum value at the detection time T1 due to the pressure wave Vc propagated through the dividing path 21. Subsequently, the second maximum value is obtained at the detection time T3 due to the pressure wave Vc propagating through the dividing path 22, and finally at the detection time T2 due to the pressure wave Vc propagating through the dividing path 23. The first maximum value will be obtained.

Here, the dividing path forming unit 24 is configured such that the difference in the propagation distance of the pressure wave Vc propagating through the pressure wave propagation path 11c is different from the difference (zero) in the propagation distance of the pressure wave Va propagating through the pressure wave propagation path 11a. The dividing paths 21, 22, and 23 are formed to be different from the difference in propagation distance of the pressure wave Vb propagating through the pressure wave propagation path 11b. For example, the difference in the propagation distance of the pressure wave Vc between the dividing path 21 and the dividing path 22 is different from the difference in the propagation distance of the pressure wave Vb between the dividing path 13 and the dividing path 14. Thereby, in the intensity distribution of the pressure wave Vc, the maximum value can be obtained at the detection time T3 that deviates from the detection times T1 and T2 of the maximum value in the intensity distribution of the pressure waves Va and Vb.
Thus, since the intensity distributions of the pressure wave Va, the pressure wave Vb, and the pressure wave Vc are obtained in different shapes, the collision calculation unit 3 calculates the collision location of the automobile M based on the number of local maximum values, for example. Can do.

  According to the present embodiment, pressure detection is performed by providing the pressure wave propagation paths 11a, 11b, and 11c so that the difference in the propagation distance of the pressure wave is different between the connection part 9a, the connection part 9b, and the connection part 9c. The intensity distributions of the pressure waves Va, Vb, and Vc detected by the element 8 can be obtained in different shapes, and collisions at a plurality of locations of the automobile can be distinguished and detected.

The dividing path forming unit 24 divides the pressure wave propagation path 11c into three dividing paths 21, 22, and 23. However, the difference in the propagation distance of the pressure wave between the connecting part 9a, the connecting part 9b, and the connecting part 9c. However, they are not limited to this as long as they are different from each other.
For example, as shown in FIG. 6, it is possible to provide a dividing path forming portion 29 that divides the pressure wave propagation path 11c to form two dividing paths 27 and 28 having different propagation distances of the pressure wave Vc.

At this time, the dividing path forming unit 29 has a difference in propagation distance of the pressure wave Vc between the dividing path 27 and the dividing path 28 smaller than a difference in propagation distance of the pressure wave Vb between the dividing path 13 and the dividing path 14. Dividing paths 27 and 28 are formed so that Thereby, as shown in FIG. 7, the intensity distribution of the pressure wave Vc detected by the pressure detection element 8 is caused by the pressure wave Vc propagated through the dividing paths 27 and 28 at the detection time T1 and the detection time T3. It has two local maximum values, and its shape is different from the intensity distribution of the pressure wave Vb propagated through the pressure wave propagation path 11b. Therefore, for example, the collision calculation unit 3 can calculate the collision location of the automobile M based on the difference between the detection time T1 at which the first maximum value appears and the detection time T3 at which the second maximum value appears.
Thus, by providing the pressure wave propagation paths 11a, 11b, and 11c so that the difference in the propagation distance of the pressure wave is different between the connecting portion 9a, the connecting portion 9b, and the connecting portion 9c, the pressure waves Va, Vb, Vc intensity distributions can be obtained in different shapes, and collisions at a plurality of locations in an automobile can be distinguished and detected.

Embodiment 3
In the first and second embodiments, the dividing path forming portion is provided in the connection portion protruding from the housing 7, but the introduction of introducing the pressure wave into the pressure detection chamber D of the housing 7 through the pressure wave propagation path. As long as it is provided in the part, it is not limited to the connection part.
For example, as shown in FIG. 8, connection portions 31 a and 31 b are provided instead of the connection portions 9 a and 9 b of the first embodiment, and the propagation tube 2 that connects the pressure generation chamber Rb of the automobile M and the connection portion 9 b is replaced. A propagation tube 32 that connects the pressure generating chamber Rb and the connecting portion 31b can be provided. Here, the propagation tubes 2 and 32 constitute the introduction part in the present invention.

The connecting portion 31a is for connecting the propagation tube 2 extending from the pressure generating chamber Ra to the housing 7, has a cylindrical shape, and an uneven portion (not shown) is formed on the outer peripheral portion thereof. A pressure wave propagation path 33a that extends from the pressure wave propagation path 6 of the propagation tube 2 and extends linearly to the pressure detection chamber D of the housing 7 is formed inside the connection portion 31a.
The connection portion 31b is for connecting the propagation tube 32 extending from the pressure generating chamber Rb, has the same shape as the connection portion 31a, and communicates with the inside of the propagation tube 32 to reach the pressure detection chamber D. A pressure wave propagation path 33b extending in a straight line is formed.

  The propagation tube 32 has a cylindrical shape, and a pressure wave propagation path 34 extending from one end to the other end is formed therein. The propagation tube 32 is provided with a division path forming portion 37 that divides a part of the pressure wave propagation path 34 to form two division paths 35 and 36 having different propagation distances of the pressure wave Vb.

Thereby, the intensity distribution when the pressure wave Va generated in the pressure generating chamber Ra is detected by the pressure detecting element 8 is obtained in substantially the same shape as the intensity distribution shown in FIG. The intensity distribution when the generated pressure wave Vb is detected by the pressure detection element 8 is obtained in substantially the same shape as the intensity distribution shown in FIG.
According to the present embodiment, by providing the dividing path forming part 37 in the pressure wave propagation path 34 of the propagation tube 32, the intensity distributions of the pressure wave Va and the pressure wave Vb detected by the pressure detection element 8 are different in shape. Thus, it is possible to distinguish and detect collisions at a plurality of locations of the automobile.

Embodiment 4
In the first to third embodiments, the pressure detection chamber D in the housing 7 is always in communication with the pressure wave propagation path of the connecting portion, but a pressure wave passes between the pressure detection chamber D and the pressure wave propagation path. Possible valves can also be arranged.
For example, as shown in FIG. 9, in the casing 7 of the first embodiment, a sheet-like valve is provided between the pressure detection chamber D and the pressure wave propagation path 11a and between the pressure detection chamber D and the pressure wave propagation path 11b. 41 can be arranged. This valve 41 allows the propagation of the pressure waves Va and Vb only from the pressure wave propagation paths 11a and 11b to the pressure detection chamber D, and the pressure waves Va and Vb from the pressure detection chamber D to the pressure wave propagation paths 11a and 11b. It has the function of a so-called check valve that blocks propagation.
Accordingly, for example, the pressure wave Va introduced from the pressure wave propagation path 11a into the pressure detection chamber D is prevented from entering the pressure wave propagation path 11b, and the pressure waves Va and Vb are accurately determined by the pressure detection element 8. Can be detected.

  In the first to fourth embodiments described above, the dividing path forming section is not provided in the pressure wave propagation path for propagating the pressure wave Va generated in the pressure generating chamber Ra of the automobile M, that is, the dividing path forming section is Although it provided in other than one of several introduction parts, the difference of the propagation distance of a pressure wave should just differ among several introduction parts, and a division path formation part can also be provided in all the introduction parts. However, since the detection time of the pressure wave may be delayed by providing the dividing path forming portion, it is preferable to provide the dividing path forming portion other than one of the plurality of introducing portions.

  Moreover, in said Embodiment 1-4, the protrusion part is not provided in one division path among the some division paths formed in the pressure wave propagation path, ie, a protrusion part is among several division paths. However, it is only necessary that the difference in the propagation distance of the pressure wave is different between the plurality of introducing portions, and the protruding portions can be provided in all the dividing paths. However, since there is a possibility that the detection time of the pressure wave may be delayed by providing the protrusion, it is preferable that the propagation distance of the pressure wave is increased for other than one of the plurality of division paths.

Further, the pressure wave propagation path for propagating the pressure wave Va generated in the pressure generation chamber Ra of the automobile M can be divided into a plurality of division paths having the same propagation distance. For example, as shown in FIG. 10, the dividing wall 51 is provided in the pressure wave propagation path 11a formed in the connection part 9a of Embodiment 1, and the two division paths 52 and 53 which have the same propagation distance are formed. be able to.
At this time, the dividing paths 52 and 53 are formed to have the same path width as the two dividing paths 13 and 14 formed in the pressure wave propagation path 11b, whereby the pressure wave Va and the pressure wave Vb When detected by the detection element 8, the distortion of the intensity distribution can be matched to some extent, and the intensity distribution can be accurately compared.

  DESCRIPTION OF SYMBOLS 1 Pressure sensor, 2, 32 Propagation tube, 3 Collision calculating part, 4 Air bag control part, 5a, 5b Air bag apparatus, 6, 11a, 11b, 11c, 33a, 33b, 34 Pressure wave propagation path, 7 housing | casing, 8 Pressure detecting element, 9a, 9b, 9c, 31a, 31b Connection part, 10 Concavity and convexity part, 12, 24, 37 Dividing path forming part, 13, 14, 21, 22, 23, 35, 36, 52, 53 Dividing path 15, 25, 51 Split wall, 16, 26 Projection, 17a, 17b Inflator, 18a, 18b Curtain airbag, 41 Valve, Ra, Rb Pressure generation chamber, Va, Vb, Vc Pressure wave, D Pressure detection chamber, M car, S1 front door, P center pillar, S2 rear door, T0 detection start time, T1, T2, T3 local maximum detection time.

Claims (7)

A housing,
A pressure detecting element disposed in the housing;
A pressure wave propagation path for propagating a pressure wave generated by the automobile being compressed, and a plurality of introduction parts for introducing the pressure wave into the housing through the pressure wave propagation path;
A dividing path forming section that divides the pressure wave propagation path formed in all or other than the plurality of introduction sections to form a plurality of dividing paths having different propagation distances of the pressure wave, and
A pressure sensor having a difference in propagation distance of the pressure wave between the plurality of introduction portions.   The pressure sensor according to claim 1, wherein the dividing path forming portion is provided in addition to one of the plurality of introducing portions.   3. The pressure sensor according to claim 1, wherein the dividing path forming unit is deformed so that a propagation distance of the pressure wave becomes long except for one of the plurality of dividing paths.   The plurality of introduction portions protrude from the housing to the outside and connect the plurality of propagation tubes that propagate the pressure wave extending from a plurality of locations of the automobile, and the pressure wave propagation path is formed therein. The pressure sensor as described in any one of Claims 1-3 provided in a some connection part.   The plurality of introduction portions are provided in a propagation tube that extends from a plurality of locations of the automobile and is connected to the housing and has the pressure wave propagation path formed therein. The described pressure sensor.   The pressure sensor according to any one of claims 1 to 5, further comprising a valve that is disposed in the casing and allows the pressure wave to pass only from the pressure wave propagation path into the casing. The plurality of introduction parts are composed of a first introduction part and a second introduction part in which the pressure wave propagation paths are respectively formed,
The dividing path forming section forms two dividing paths only in the pressure wave propagation path formed in the first introduction section, and the propagation distance of the pressure wave propagating through the two dividing paths is different. The pressure sensor according to claim 1, wherein one of the dividing paths is deformed.

Images