Enclosed volume pressure sensor with insect protection features

Abstract

This disclosure relates to a collision sensor for a vehicle. The collision sensor includes: a housing defining an internal volume; a pressure sensor element disposed within the internal volume of the housing; and a membrane configured to isolate the internal volume of the housing from ambient air. The membrane is deformable for transmitting pressure pulses, indicative of a collision, for detection by the pressure sensor element.

Description

Technical Field

[0001] This disclosure generally relates to sensors for vehicles, and more specifically to a pressure sensor for detecting collisions. Background Technology

[0002] Currently, pressure-based collision sensors are placed in vehicle doors to detect collisions early by monitoring deformation of the door cavity. Door deformation generates rapid pressure changes, and the pressure sensor monitors this pressure divided by the change in ambient pressure. Typically, a pressure sensor assembly includes a mechanical housing, a pressure port cover, an internal gasket, and a pressure sensor with or without a printed circuit board (PCB).

[0003] Typically, pressure sensor assemblies used in pressure-based impact sensors are configured as open volumes, meaning that air pressure has a direct path to the pressure sensor assembly. Pressure sensor assemblies usually have a cover with a restrictive opening ranging from 0.3 to 2.5 mm. The openings in pressure sensor assemblies can be even smaller. The cover is designed to prevent contaminants, debris, and insects from entering the device. Insects (such as ants in some parts of the world) can enter the pressure device and damage the sensor. Some ant species can enter through gaps as small as 0.2 mm. Restricting the opening in the pressure sensor to 0.2 mm or less can present manufacturing difficulties and increase the risk of frost, dust, and other contaminants clogging the opening on the sensor. Summary of the Invention

[0004] This disclosure provides a collision sensor for a vehicle. The collision sensor includes: a housing defining an internal volume; a pressure sensor element disposed within the internal volume of the housing; and a diaphragm configured to isolate the internal volume of the housing from ambient air. The diaphragm is deformable for transmitting pressure pulses, indicative of a collision, to be detected by the pressure sensor element.

[0005] This disclosure also provides a pressure sensor assembly. The pressure sensor assembly includes: a housing defining an internal volume; a pressure sensor element disposed within the internal volume of the housing; and a diaphragm configured to isolate the internal volume of the housing from ambient air, wherein the diaphragm is deformable for transmitting pressure pulses, indicating impact, for detection by the pressure sensor element.

[0006] This disclosure also provides a sensor assembly for a vehicle. The sensor assembly includes: a housing defining an internal volume; a sensor element disposed within the internal volume of the housing; a membrane configured to isolate the internal volume of the housing from ambient air, wherein the membrane is deformable for transmitting pressure pulses for detection by the sensor element; a balancing channel located between the internal volume of the housing and the ambient air; and a breathable membrane made of a waterproof material covering the balancing channel.

[0007] These and other aspects of this disclosure are disclosed in the following detailed description of the embodiments, the appended claims, and the accompanying drawings. Attached Figure Description

[0008] Further details, features, and advantages of this disclosure are available from the following description of embodiments with reference to the accompanying drawings.

[0009] Figure 1 A side view of a motor vehicle according to this disclosure is shown; Figure 2 A cross-section of a door panel of a motor vehicle is shown, in which a first pressure sensor assembly is disposed; Figure 3 A cross-section of the first pressure sensor assembly used to detect a collision in the vehicle is shown. Figure 4 The first pressure sensor element used in a pressure sensor for detecting a collision in a vehicle is shown. Figure 5 Show Figure 3 A partial cross-section of the first pressure sensor assembly is shown. Figure 6 A partial cross-section of a second pressure sensor assembly according to this disclosure is shown; Figure 7 Show Figure 6 A perspective view of the internal seal of the second pressure sensor assembly shown; Figure 8 A perspective view of a second pressure sensor element according to this disclosure is shown; Figure 9 A partial cross-section of a third pressure sensor assembly according to this disclosure is shown; Figure 10 A partial cross-section of the fourth pressure sensor assembly according to this disclosure is shown; Figure 11 A partial perspective view of the fifth pressure sensor assembly according to this disclosure is shown; Figure 12 Show Figure 11 The image shows a partial cross-section of the fifth pressure sensor assembly. Detailed Implementation

[0010] This disclosure will be described in detail with reference to the accompanying drawings and the following embodiments.

[0011] This disclosure provides a pressure sensor assembly having a design feature designed to prevent ants or other insects from interfering with the operation of the pressure sensor element therein.

[0012] This disclosure includes a pressure sensor designed as a closed-loop volumetric sensor solution by molding an internal gasket together with a thin film, wherein the film deforms with large pressure changes. The internal gasket can be made of a silicon-based material, which minimizes the effects of temperature and aging. The film prevents or blocks insects from accessing the inside of the electronic components. The film can be easily integrated into existing internal gasket designs as part of a pressure sensor assembly by simple tooling modifications or by directly overmolding the film onto a plastic cap port. The film can also be integrated into the sensor device at the component device level and is supplied by a supplier of pressure sensor components. The thickness and stiffness of the film can be easily varied to ensure that the transfer function of the pressure pulse is not attenuated for detecting impact pulses, and can be increased to enhance robustness against insects. The film creates a closed volume whose pressure will vary with temperature and atmospheric pressure. The sensor device already has existing filters that can compensate for slow environmental pressure changes caused by the closed volume.

[0013] A second membrane, made of a waterproof and breathable material, can be added to the enclosed volume to help the sensor compensate for variable environmental pressure changes. This second membrane can be manufactured, for example, from Gore-Tex.

[0014] like Figure 1 As shown, the motor vehicle 10 (e.g., a passenger car or a truck) includes a body 12 with side doors 14, 16. The side doors 14, 16 include a front door 14 and a rear door 16. Figure 2 A cross-section of one of the side doors 14, 16 is shown, defining a door cavity 18 in which a first pressure sensor assembly 20 is disposed. The door cavity 18 may be a generally closed volume with limited openings, such as gaskets for windows and one or more drain holes for liquid drainage.

[0015] When a collision occurs with either of the side doors 14 or 16, the door cavity 18 may deform, causing a sudden pressure pulse, which can be detected by the first pressure sensor assembly 20. Pressure-based collision detection may offer several advantages over other types of collision detection, such as acceleration-based detection. For example, pressure-based collision detection can provide a faster signal than acceleration-based detectors, which can improve the performance of side protection devices such as side curtain airbags.

[0016] Figure 3 A cross-section of a first pressure sensor assembly 20 for detecting a vehicle collision is shown. The first pressure sensor assembly 20 may have a conventional design and includes a housing 22 defining an internal volume 24 containing a printed circuit board (PCB) 26 and a first pressure sensor element 28. The first pressure sensor element 28 may be, for example, a surface-mount microelectromechanical system (MEMS) device configured to measure air pressure. The housing 22 defines an electrical socket 30 having pins 32 for receiving a corresponding plug for electrical connection to the first pressure sensor element 28 and / or other components on the PCB 26.

[0017] The first pressure sensor assembly 20 also includes a cover 40 defining a plate 42 that covers the housing 22 to at least partially enclose the internal volume 24. The cover 40 can be attached to the housing 22 using snap-fit ​​and gaskets. Alternatively, the cover 40 can be permanently sealed to the housing 22. For example, the cover 40 can be attached to the housing 22 by laser welding, ultrasonic welding, using adhesives, and / or other methods of adhesion. The cover 40 includes a protruding structure 43 on the plate 42 opposite the internal volume 24. The protruding structure 43 defines a channel 44 having an opening 45 opposite the first pressure sensor element 28. Thus, the channel 44 can conduct ambient air to the first pressure sensor element 28. In some embodiments, and as... Figure 3 As shown, channel 44 defines a 90-degree bend. In some embodiments, and also as... Figure 3 As shown, the opening 45 of the channel 44 is positioned below the first pressure sensor element 28. This arrangement functions similarly to an inverted cup, trapping air and preventing water intrusion should the first pressure component be submerged. A first internal seal 50 is disposed between the cover 40 and the first pressure sensor element 28. The first internal seal 50 may be made of an elastic material (e.g., silicone) and provides a direct path between the channel 44 and the first pressure sensor element 28. Alternatively, the first internal seal 50 may be made of another material (e.g., a rubber-based material or a thermoplastic elastomer (TPE)). In some embodiments, the first internal seal 50 may be directly molded into the cover 40 using a two-stage injection molding process.

[0018] Figure 4A first pressure sensor element 28 of a first pressure sensor assembly 20 is shown. The first pressure sensor element 28 includes a body 70 having four sidewalls 72 and a top 74 defining a port aperture 76. The first pressure sensor element 28 also includes a sensor device 80 mounted within the body 70, which is connected to external circuitry via a plurality of conductors 82 extending through two or more of the four sidewalls 72. The port aperture 77 may have a diameter of approximately 2.5 mm. In an alternative design (not shown), the top 74 may instead have a plurality of smaller apertures, such as four apertures, each having a diameter of 0.2 mm. These smaller apertures can prevent debris and insects from entering the body 70 of the first pressure sensor element 28. However, such restrictive openings may be difficult to manufacture and may increase the risk of frost, dust, and other contaminants clogging the apertures on the sensor.

[0019] Figure 5 A partial cross-section of the first pressure sensor assembly 20 is shown. As shown, plate 42 includes an inner surface 52 facing the internal volume 24. A square wall 54 protrudes from the inner surface 52 toward the PCB 26 and surrounds a first internal seal 50 for positioning the first internal seal 50 in a direct fluid path having a channel 44. The inner surface 52 of plate 42 also defines a triangular protrusion 56 that contacts the first internal seal 50 to deform the first internal seal 50 between the triangular protrusion 56 and the first pressure sensor element 28 and form an hermetically tight seal. Also as shown, the first internal seal 50 has a generally annular shape with a through-hole 58 for passing ambient air through the channel 44 to the first pressure sensor element 28. The generally annular shape of the first internal seal 50 may have a rounded rectangular cross-section, as shown. However, the first internal seal 50 may have different cross-sectional shapes, such as rectangular, circular, elliptical, etc. The through-hole 58 may have a generally rectangular cross-sectional shape, as shown. However, the through hole 58 can have another shape, such as a circular or elliptical cross-section.

[0020] Figure 6A partial cross-section of a second pressure sensor assembly 120 according to this disclosure is shown. Except for the differences described herein, the second pressure sensor assembly 120 may be identical or similar to the first pressure sensor assembly 20. The second pressure sensor assembly 120 includes a second internal seal 150 in place of the first internal seal 50. The second internal seal 150 includes a first membrane 160 that spans the center of the through-hole 58 and prevents fluid communication through the second internal seal 150. Thus, the second internal seal 150 serves to block fluid communication between the ambient space and the internal volume 24 of the housing 22. The first membrane 160 is flexible and deforms in response to pressure pulses, thus not impeding the first pressure sensor element 28 from detecting pressure pulses indicating an impact. In some embodiments, the first membrane 160 may be integrally formed with the second internal seal 150, for example, formed as a single molded part. However, the first membrane 160 may be formed separately and / or made of a material different from other portions of the second internal seal 150.

[0021] Figure 7 A perspective view of the second internal seal 150 is shown. As shown, the second internal seal 150 includes a tubular portion 152 having a generally cuboid annular shape and defining a through-hole 58, and a first membrane 160 disposed at the center of the through-hole 58. The second internal seal 150 also includes dome-shaped protrusions 156 at each outer corner. The dome-shaped protrusions 156 may engage with corresponding structures on the inner surface 52 of the plate 42 and / or the top 74 of the first pressure sensor element 28.

[0022] Figure 8 A perspective view of a second pressure sensor element 128 according to this disclosure is shown. Except for the differences described herein, the second pressure sensor element 128 may be identical or similar to the first pressure sensor element 28. The second pressure sensor element 128 includes a second membrane 170 made of an elastic material (e.g., a silicone film) and is directly attached to the top 74 of the first pressure sensor element 28 and covers the port opening. Figure 8 (Not shown in the image). The second pressure sensor element 128 can be used in place of the first pressure sensor element 28 to prevent insects or debris from contacting the sensor device 80. The second membrane 170 can be made of a flexible material and deform in response to pressure pulses, so as not to prevent the second pressure sensor element 128 from detecting pressure pulses indicating an impact.

[0023] Figure 9A partial cross-section of a third pressure sensor assembly 220 according to this disclosure is shown. Except for the differences described herein, the third pressure sensor assembly 220 may be identical or similar to the first pressure sensor assembly 20. The third pressure sensor assembly 220 includes a third membrane 222 within a channel 44 and adjacent to an opening 45. The third membrane 222 may span the channel 44 to block direct air communication between ambient air and the first pressure sensor element 28. The third membrane 222 may be made of a flexible material and deform in response to pressure pulses, thus not hindering the first pressure sensor element 28 from detecting pressure pulses indicating an impact.

[0024] Figure 10 A partial cross-section of a fourth pressure sensor assembly 320 according to this disclosure is shown. Except for the differences described herein, the fourth pressure sensor assembly 320 may be identical or similar to the first pressure sensor assembly 20. The fourth pressure sensor assembly 320 includes a fourth membrane 322 within a channel 44 and spaced apart from an opening 45. The fourth membrane 322 may span the channel 44 to block direct air communication between ambient air and the first pressure sensor element 28. The fourth membrane 322 may be made of a flexible material to deform in response to a pressure pulse, thus not hindering the first pressure sensor element 28 from detecting pressure pulses indicating an impact.

[0025] Figure 11-12 Each is shown as a fifth pressure sensor assembly 420 according to this disclosure. Except for the differences described herein, the fifth pressure sensor assembly 420 may be identical or similar to the third pressure sensor assembly 220. A protruding structure 43 of the cover 40 defines a balancing channel 422 located between the internal volume 24 of the housing 22 and ambient air. The balancing channel 422 allows the internal volume 24 of the housing 22 to slowly balance the pressure with the ambient air, for example, in response to changes in ambient air pressure due to temperature or atmospheric pressure variations, or when the vehicle 10 is driven up or down elevation changes. The balancing channel 422 may restrict airflow so as not to impede the first pressure sensor element 28 from detecting sudden changes in ambient air pressure indicative of a collision. A breathable membrane 424 made of a waterproof material (e.g., Gore-Tex) covers the balancing channel 422. The breathable membrane 424 allows air to pass relatively unobstructed while preventing the passage of water and / or other contaminants. The balancing channel 422 is shown passing through the protruding structure 43 and into the channel 44. However, the balance channel 422 and the breathable membrane 424 can be located in other positions on the cover 40 and / or in other positions on the housing 22.

[0026] The foregoing description is not intended to be exhaustive or limiting of this disclosure. Various elements or features of a particular embodiment are generally not limited to that particular embodiment, but are interchangeable where applicable and can be used in selected embodiments even if not specifically shown or described. Similarly, they can be varied in many ways. Such variations should not be considered as departing from this disclosure, and all such modifications are intended to be included within the scope of this disclosure.

Claims

1. A collision sensor for a vehicle, comprising: The outer shell, which limits the internal volume; A pressure sensor element is disposed within the internal volume of the housing; and A membrane, configured to isolate the internal volume of the housing from ambient air. The membrane is deformable to transmit pressure pulses that indicate collisions and are detected by the pressure sensor element.

2. The collision sensor for a vehicle according to claim 1, further comprising: A cover that covers the housing to at least partially close the internal volume, the cover defining a channel having an opening opposite the pressure sensor element; and An internal seal is disposed between the cover and the pressure sensor element.

3. The collision sensor for a vehicle according to claim 2, wherein, The internal seal has a generally annular shape defining a through-hole, and wherein the membrane is disposed within the through-hole of the internal seal.

4. The collision sensor for a vehicle according to claim 2, wherein, The membrane is integrally formed with the internal seal.

5. The collision sensor for a vehicle according to claim 2, wherein, The internal seal is made of at least one of the following materials: silicone resin, rubber-based materials, and thermoplastic elastomers (TPE).

6. The collision sensor for a vehicle according to claim 1, wherein, The pressure sensor element includes a body having a top defining a port orifice, wherein the membrane is directly attached to the top of the pressure sensor element and covers the port orifice.

7. The collision sensor for a vehicle according to claim 1, further comprising a cover covering the housing to at least partially enclose the internal volume, the cover defining a channel having an opening opposite the pressure sensor element, and in, The membrane is disposed in the channel and adjacent to the opening.

8. The collision sensor for a vehicle according to claim 1, further comprising a cover covering the housing to at least partially enclose the internal volume, the cover defining a channel having an opening opposite the pressure sensor element, and in, The membrane is disposed in the channel and spaced apart from the opening.

9. The collision sensor for a vehicle according to claim 1, further comprising: A balancing channel is located between the internal volume of the housing and the ambient air; and A breathable membrane made of waterproof material covers the balance channel.

10. A pressure sensor assembly, comprising: The outer shell, which limits the internal volume; A pressure sensor element is disposed within the internal volume of the housing; and A membrane, configured to isolate the internal volume of the housing from ambient air. The membrane is deformable to transmit pressure pulses that indicate collisions and are detected by the pressure sensor element.

11. The pressure sensor assembly of claim 10, further comprising: A cover that covers the housing to at least partially close the internal volume, the cover defining a channel having an opening opposite the pressure sensor element; and An internal seal is disposed between the cover and the pressure sensor element.

12. The pressure sensor assembly of claim 11, wherein, The internal seal has a generally annular shape defining a through-hole, and wherein the membrane is disposed within the through-hole of the internal seal.

13. The pressure sensor assembly of claim 11, wherein, The membrane is integrally formed with the internal seal.

14. The pressure sensor assembly of claim 11, wherein, The internal seal is made of at least one of the following materials: silicone resin, rubber-based materials, and thermoplastic elastomers (TPE).

15. The pressure sensor assembly of claim 10, wherein, The pressure sensor element includes a body having a top defining a port orifice, wherein the membrane is directly attached to the top of the pressure sensor element and covers the port orifice.

16. The pressure sensor assembly of claim 10, further comprising a cover that covers the housing to at least partially close the internal volume, the cover defining a channel having an opening opposite the pressure sensor element, and in, The membrane is disposed in the channel and adjacent to the opening.

17. The pressure sensor assembly of claim 10, further comprising a cover that covers the housing to at least partially close the internal volume, the cover defining a channel having an opening opposite the pressure sensor element, and in, The membrane is disposed in the channel and spaced apart from the opening.

18. The pressure sensor assembly of claim 10, further comprising: A balancing channel is located between the internal volume of the housing and the ambient air; and A breathable membrane made of waterproof material covers the balance channel.

19. A sensor assembly for a vehicle, comprising: The outer shell, which limits the internal volume; A sensor element disposed within the internal volume of the housing; A membrane, configured to isolate the internal volume of the housing from ambient air, wherein the membrane is deformable for transmitting pressure pulses to be detected by the sensor element; A balancing channel located between the internal volume of the housing and the ambient air; and A breathable membrane made of waterproof material covers the balance channel.

20. The sensor assembly of claim 19, further comprising: A cover that covers the housing to at least partially close the internal volume, the cover defining a channel having an opening opposite the sensor element; and An internal seal is disposed between the cover and the sensor element, wherein the internal seal has a generally annular shape defining a through-hole, and wherein the membrane is disposed within the through-hole of the internal seal.

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