WO2001046666A1

WO2001046666A1 - Pressure detector device, particularly for an air conditioning unit

Info

Publication number: WO2001046666A1
Application number: PCT/EP2000/013063
Authority: WO
Inventors: Ugo Sortilli; Pietro Orsero
Original assignee: Bitron S.P.A.
Priority date: 1999-12-22
Filing date: 2000-12-21
Publication date: 2001-06-28
Also published as: ITTO991140A0; ITTO991140A1; IT1311270B1; AU3365101A

Abstract

The device (1) comprises a rigid support structure (1-4) in which is defined a chamber (9) which has an aperture (8, 12) for the introduction of a fluid the pressure of which is to be measured, and in which is mounted a support plate (16) of electrically insulating material provided with electrically conductive tracks (17), and a pressure sensor device (20) including a casing (21) in which is mounted a pressure transducer (22) facing an aperture or window (23) in the casing (21). The pressure sensor device (20) is supported by the plate (16) by means of the mechanical and electrical connection of its electrical terminals (24) to conductive tracks (17) of the plate (16) in such a way that the casing (21) of the pressure sensor device (20) extends in spaced relationship with respect to the support plate (16) and in use is entirely immersed in the fluid introduced into the said chamber (9).

Description

Pressure detector device, particularly for an air conditioning unit

The present invention relates to a pressure detector device used, in particular, but not exclusively, in an air conditioning unit.

The pressure detector device according to the invention comprises : a rigid support structure in which is defined a chamber which has an aperture for the introduction of a fluid the pressure of which it is intended to measure, and in which is mounted a support plate of electrically insulating material provided with electrically conductive tracks; and a pressure sensor device including a casing in which is mounted an electrical or electronic pressure transducer facing an aperture or window of the casing; the pressure sensor device having a plurality of electrical terminals which extend out from the said casing; the said pressure sensor device being supported by the said plate by means of the mechanical and electrical connection of the said electrical terminals to the conductive tracks of the support plate, in such a way that the casing of the pressure sensor device extends in spaced relationship from the plate and in use is entirely immersed in the fluid introduced into the chamber.

The pressure detector device has a rather simple structure and its assembly is extremely easy. The pressure sensor device of this detector device is uniformly stressed in operation over its entire surface by the pressure of the fluid introduced into the chamber, and the connections (typically soldered) of its feet or terminals are not mechanically stressed by the effect of this pressure.

Further characteristics and advantages of the invention will become apparent from the following detailed description given purely by way of non-limitative example, with reference to the attached drawings , in which :

Figure 1 is an axial sectional view of a pressure detector device according to the invention; and

Figure 2 is a perspective view of a pressure sensor device usable in the detector of the invention.

In Figure 1 a pressure detector device according to the invention is generally indicated with the reference 1.

This device comprises a support structure which in the exemplary embodiment illustrated comprises a lower, essentially tubular, body 2 made, for example, from a metal material such as aluminium, and by an upper, essentially bell-shape body 3, made for example of a moulded plastics material such as polybutyleneterephthalate (PBT) . Between the lower body 2 and the upper body 3 is interposed a sheet 4 made for example of a moulded plastics material such as a polyphenylsulphate (PPS) .

Between the upper body 3 and the intermediate plate 4 there is a sealing ring 5.

In the illustrated embodiment the lower tubular body 2 has an upper angular edge 2a in contact with the lower face of the intermediate plate 4. Inwards of this edge 2a, between the intermediate plate 4 and the tubular lower body 2 is interposed and compressed a sealing flange 6 of elastomeric material .

The bodies 2 and 3 are clamped axially towards one another against the intermediate plate 4 by means of a metal gripping band 7.

The tubular lower body 2 defines an inlet passage 8 for the introduction of a fluid the pressure of which is to be measured, into a chamber 9 defined between the upper end portion of the body 2 and the sheet 4. This sheet therefore acts as an upper delimitation wall of the measurement chamber 9.

Between the inlet passage 8 and the measurement chamber 9 in the body 2 there is defined a constriction 10 in which is snap-engaged an apertured member 11 having a plurality of apertures or passages 12 for the introduction of fluid into the measurement chamber.

Through the intermediate plate 4 pass a plurality of electrically conductive connector members, indicated 13. These members pass beyond a wall or upper partition 14 of the bell-shape body 3 and protrude into an open cavity 15 formed in the upper part of the bell-shape body 3 in the form of connectors .

The connection members 13 have respective lower terminal portions 13a which pass through the intermediate plate 4 and protrude into the measurement chamber 9.

In the measurement chamber there is mounted a support plate 16 of electrically insulating material provided on at least one face with electrically conductive tracks 17 formed for example using printed circuit techniques.

This support plate 16 is mechanically and electrically connected to the lower end portions 13a of the connection members 13.

Conveniently, the said connection members 13 are embedded in the intermediate plate 4 upon moulding of this latter. For the purpose of improving the seal of the chamber 9 and preventing the escape of fluid under pressure through possible interstices between the connection members 13 and the surrounding material of the plate 4 , the face of this plate diverted towards the measurement chamber 9 has sealing formations 18 of elastomeric material moulded and vulcanised in situ around the terminal portions 13a of the members 13.

Conveniently, these sealing formations 18 are formed integrally with the sealing flange 6 which is "pinched" between the lower tubular body 2 and the intermediate body 4.

Advantageously the general formation of elastomeric material moulded over and vulcanised in situ onto the intermediate plate 4 can also form integral spacer appendices such as those indicated 19 in Figure 1 for damped support of the support plate 16.

Preferably, the peripheral edge or outline of the plate 16 is at least partially spaced from the surface of the surrounding wall of the measurement chamber 9.

In the embodiment illustrated in Figure 1 the face of the support plate 16 which faces away from the intermediate plate 4 is mechanically and electrically connected to a pressure sensor device generally indicated 20.

This device is better visible in Figure 2.

The pressure sensor device 20 in the embodiment shown comprises a casing 21 on which is mounted an electrical or electronic pressure transducer 22 facing an aperture or window 23 in this casing.

Outside the casing 21 extends a plurality of electrical terminals or feet 24 the ends of which are soldered to conductive tracks 17 of the support plate 16 (Figure 1) .

The pressure sensor device 20 can, for example, be the device made and sold by the company SensoNor ASA of Horton, Norway under the identification SP 18 MAP/BAP or other equivalent. The device SP 18 MAP/BAP encloses a silicone membrane piezoelectric transducer and associated integrated circuit (ASIC) processor.

In any case, the pressure sensor device 20 is connected to the support plate 16 in such a way that its casing 21 extends in spaced relationship from this plate and in use is entirely emersed in the fluid introduced into the measurement chamber 9.

Conveniently, although not necessarily, an aperture, indicated 25 in Figure 1, is formed in the region of the support plate 16 facing the window 23 in the pressure sensor device 20, to improve the exposure of the pressure transduser to the fluid. The complete exposure of the surface of the casing 21 of the sensor 20 to the pressure of the fluid contained in the chamber 9 makes it possible to avoid stresses on the soldered connections between the feet of this device and the conductive tracks of the support plate 16.

Numerous variants are possible with respect to the simplified embodiment described and illustrated in the drawings .

Thus, for example, the intermediate plate 4 may be formed integrally with the upper body 3.

Moreover, the support plate 16 may be disposed in a widely spaced relationship from the intermediate plate 4 and the pressure sensor device 20 may be connected to the face of the plate 16 which faces the plate 4.

In another variant embodiment, the support plate 16 can be interconnected with further sensor devices such as, for example, a temperature sensor, and in this case at least one further connection member 13 must be provided to make it possible to carry the signal generated by such additional sensor to external processing circuits .

Naturally, the principle of the invention remaining the same, the embodiments and the details of construction can be further varied with respect to what has been described and illustrated purely by way of non-limitative example, without by this departing from the ambit of the invention as defined in the attached Claims .

Claims

1. A pressure detector device (1), particularly for an air conditioning unit comprising a rigid support structure (1-4) in which is defined a chamber (9) which has an aperture (8, 12) for the ingress of a fluid the pressure of which is to be measured, and in which is mounted a support plate (16) of electrically insulating material provided with electrically conductive tracks (17) ; and a pressure sensor device (20) including a casing (21) in which is mounted an electrical or electronic pressure transduser (22) facing an aperture or window (23) in the casing (21) ; the pressure sensor device (20) having a plurality of electrical terminals (24) which extend out from the said casing (21) ; the said pressure sensor device (20) being supported by the said plate (16) by means of mechanical and electrical connection of the said electrical terminals (24) to conductive tracks (17) of the said plate (16) in such a way that the casing (21) of the pressure sensor device (20) extends in spaced relationship with respect to the support plate (16) and in use is entirely immersed in the fluid introduced into the said chamber (9) .

2. A device according to Claim 1, in which the said support plate (16) is connected to conductive connections members

(13) which project into the said chamber (9) through a delimiting wall (4) of plastics material moulded over the said members (13) and which traverse the support structure

(3) in such a way as to be accessible outside it to allow connection of the pressure sensor device (20) to external circuits .

3. A device according to Claim 2 , in which sealing formations (18) of fluid-tight type elastomeric material moulded and vulcanised in situ extend around the portions

(13a) of the said connection members (13) which project into the chamber (9) on the face of the said delimiting wall (4) .

4. A device according to Claim 2 or 3 , in which the said support structure (1-4) comprises an essentially tubular element (2) one end of which is coupled to a closure element (3) , and the said delimiting wall is a plate (4) of electrically insulating material which is interposed between the tubular element (2) and the closure element (3) and which, together with the tubular element (2), defines the said chamber (9) .

5. A device according to Claim 2 or Claim 3 , in which the said support structure (1-4) comprises an essentially tubular element (2) one end of which is coupled to a closure element (3, 4), which forms the said delimiting wall (4) .

6. A device according to Claim 4 or Claim 5 , in which between the tubular element (2) and the said delimiting wall

(4) are interposed fluid tight sealing means (6) .

7. A device according to Claims 3 and 6 in which the said sealing means comprise a flange (6) of elastomeric material clamped between the tubular element (2) and the said delimiting wall (4) , the said flange (6) being formed of an elastomeric material moulded and vulcanised in situ on the said delimiting wall (4) integrally with the said sealing formations (18) associated with the connection members (13) .

8. A device according to any preceding Claim, in which the said pressure sensor device (20) is connected to the face of the support plate (16) facing away from the said delimiting wall.

9. A device according to any of Claims 1 to 7 , in which the said pressure sensor device (20) is connected to the face of the support plate (16) which faces the said delimiting wall (4) .

10. A device according to any preceding Claim, in which there is formed an aperture (25) in the portion of the said support plate (16) which faces the said window (23) of the casing (21) of the pressure sensor device (20) .

11. A pressure detector device according to any preceding Claim, in which at least one further sensor, such as a temperature sensor, is connected to the said support plate

(16) in such away as to be, in use, totally immersed in the said fluid.