FR3120701A1 - Process for manufacturing an electronic box with a fluid sensor and electronic box obtained. - Google Patents

Abstract

Method for manufacturing an electronic box with a fluid sensor and electronic box obtained The invention relates to a method for manufacturing an electronic box (1A, 1B) with a fluid sensor (15, 35), said box comprising walls ( 2, 3, 22, 23) defining an interior housing (L), one of the walls (3, 23) being removable and closing a main access (17) to the housing; an integrated circuit board (4), placed in said housing and carrying said fluid sensor (15, 35) having a fluid inlet (25, 45); a fluid supply conduit (6, 16, 26, 36) comprising a first end (E1) connected to the sensor and a second end (E2) emerging or connected to the outside of the housing. The method is characterized in that it comprises a step of arranging said first end (E1) of the supply duct on one of said walls (2, 23) of the casing. The invention also relates to the electronic unit corresponding to the method. Figure to be published with abstract: figure 3

Description

Process for manufacturing an electronic box with a fluid sensor and electronic box obtained.

Technical field of the invention

The invention relates to a method of manufacturing an electronic unit with a fluid sensor. In particular, the case comprises an interior housing with a wall which closes access to the housing, an integrated circuit board, placed in said housing and carrying a fluid sensor; a fluid supply conduit comprising a first end connected to the sensor and a second end opening outside the housing.

The invention preferably relates to housings comprising in particular MAP (English acronym for Manifold Absolute Pressure) sensors. These sensors make it possible to measure air intake pressure values in the engine. These values transmitted to the engine computer, can make it possible to refine the quantity of fuel to be injected into the engine.

The fluid sensors concerned by the invention can be of different types, gaseous or liquid. The sensor can be a simple pressure sensor (piezoelectric or other) or a gas or liquid analysis sensor, in particular an atmospheric sensor, a pollution sensor, an alcohol level sensor conditioning or not the starting of a motor of vehicle.

Current automotive engine management (MAP) sensor electronics units have various drawbacks. Their design requires a flexible conduit connecting the fluid sensor of a printed circuit to a fluid connector fixed on a wall (or partition) of the case. This fluid connector is also generally metallic and arranged across or straddling a wall of the casing.

The assembly of the box and the connection of the flexible conduit are relatively complex and not easy. Dismantling is also complex.

In addition, the flexible conduit can be pinched when mounting the plate in the housing or when closing the housing, especially when the integrated circuit plate visually masks the flexible conduit during assembly.

The current design of these boxes can therefore be improved to facilitate assembly, disassembly and their cost of manufacture and assembly.

Objective / technical problem

The present invention aims to solve the problems mentioned above.

The invention aims in particular to avoid the problems of duct pinching during assembly.

More specifically, the present invention aims to design an electronic unit with a fluid sensor which is simpler and more economical to manufacture, to assemble and to dismantle if necessary.

A principle of the invention may be to fix the fluid supply duct (or at least the mouth of the duct or the first end of the duct intended to be connected to the sensor) inside the housing. Preferably, the duct attachment can be designed so that when the printed circuit board (or integrated) carrying the sensor is mounted (or introduced into its housing, the fluid inlet of the sensor connects to the duct or is placed in connection position to the duct before the housing is closed by one of the walls or a cover For example, the fluid supply duct can be formed in one of the walls (or partitions: support base, cover or side) of the housing .

The invention firstly relates to a method for manufacturing an electronic box with a fluid sensor, said box comprising walls (partitions or a support base) defining an interior housing, one of the walls being removable and closing a main access to housing; an integrated circuit board, placed in said housing and carrying said fluid sensor having a fluid inlet; a fluid supply conduit comprising a first end connected to the sensor and a second end opening outside the housing;
The box is distinguished in that it comprises a step of arranging the first end of the supply duct on one of the walls of the box.

Thus, pinching of a flexible conduit of the prior art during assembly or mounting of the housing is avoided.

According to other characteristics:

- The method comprises a step of configuring the housing of the housing so that the sensor is placed in the position of connection to the conduit, via the first end, during the insertion of said plate into the housing, which facilitates the assembly of the sensor to the duct, especially in assembly and blind fluid connection;

- The fluid supply duct can be formed in or fixed to one of said walls of the housing or of the support base;

- A sealed connection of the sensor to the duct can be maintained thanks to a compressed seal, for example using a housing closing wall (or cover);

- The sealed connection of the sensor can be made via a seal chosen from an O-ring, a flat point;

- The seal can advantageously be kept compressed by tightening the cover on the support base; The lid may include a wedge pressing against the plate during tightening;

- The support base can advantageously have a surface for centering (or receiving) the gasket;

- The seal centering surface can be substantially conical or with a radius of curvature to center the seal and/or to improve sealing.

The invention also relates to an electronic unit with a fluid sensor corresponding to the above method.
The casing includes walls (or a support base) defining a housing inside the casing; an integrated circuit board placed in said housing and carrying a fluid sensor having a fluid inlet; a fluid supply conduit comprising a first end connected to the sensor and a second end opening outside the housing; The box is characterized in that said first end of the supply duct is arranged on or in one of said walls of the box.

Thus, the method makes it possible to facilitate the connection of the sensor to the pipe without the drawbacks mentioned.

According to other characteristics:

- The housing can be configured in such a way that the sensor is placed in the position of connection to the duct when said plate is inserted into the housing, which facilitates assembly;

- The connection can be maintained by means of a closing wall of the housing, which facilitates in particular the dismantling of the connection by removing the wall;

- the duct can emerge on the bottom of the base-support and/or on one of the sides of the base-support, thus offering various possibilities of connection location;

- The plate can be inserted by sliding into a slot accessing the housing and in that the cover is arranged on the side of the housing so as to close the slot and come to press on the edge of the plate after assembly;

- A duct, among two possible ducts, can be configured with an external cap (or a lid) or a pre-cut membrane to close it by default.

illustrates a top view of the walls (or receiving base-support) of a printed circuit housing of an electronic box, according to a first embodiment of the invention;

illustrates an assembly of the printed circuit 4 with its fluid sensor in the housing (or in the receiving base-support 2 seen in section along AA of the previous figure), as well as the assembly of the cover 3 for closing the housing;

illustrates a sectional view of the electronic box once assembled according to Figure 2;

shows a sectional view of the an electronic box in the form of a case with a printed circuit housing in the case, according to a second embodiment of the invention.

illustrates a top view of an electronic box in the form of a case with a printed circuit in a housing of the case;

illustrates a sectional view, (similar to the ), of the printed circuit alone in the connection position with a side wall of the case-shaped case.

detailed description

In the drawings, the same references indicate identical or similar elements.

In Figures 1 to 3 is illustrated an electronic unit 1A with fluid sensor 15, obtained according to a first mode of implementation of the manufacturing method of the invention.

In FIGS. 1 and 2, the box comprises walls (base-support or receiving body 2), (or partitions separating the inside and the outside of the box) defining an interior housing (L). This housing (L) is configured to receive a printed circuit (or integrated circuit) board 4.

One of the walls 3 of the casing is removable (or removable) and closes a main access 17 (or a main opening) to the housing. This access 17 makes it possible to introduce or place the plate 4 inside the housing in the position of connection to the sensor.

The box 1A also includes the printed or integrated circuit board 4 mentioned above. The electronic plate 4 is placed in the housing (L) and carries the fluid sensor 15. The sensor 15 has an inlet 25 of fluid;

The housing also comprises a fluid supply conduit 6, 16 which is connected to the sensor 15 by a first end E1 and extends from the inlet 25 of the sensor towards or to the outside of the housing by at least one second end. opposite (E2, E3) to the first.

According to a characteristic of the first mode of implementation of the invention, the method comprises the step consisting in arranging said first end E1 of the supply duct on one of said walls 2, 23 of the casing.

In the example, the housing comprises a fluid supply conduit 6, 16 comprising a first end E1 which is connected directly to the sensor and a second end E2 (opposite to the first) which opens outside the base- support. This second end E2 is connected to an external fluid supply connector, known to those skilled in the art. The duct extends from the inlet of the sensor or from the first end E1 towards or until it emerges on an external face F1, F2 of the casing, where the second end E2 is located.

In fact, this mode includes a mouth 7, 16 for receiving the sensor (or a connection terminal to the sensor), formed here with the conduit 16 in a material of one of said walls of the housing. Alternatively, this reception or connection terminal 7 and its conduit 16 can be attached to the box by having been attached or glued to one of the walls of the box.

In the example , the duct is formed in a bottom wall of the support base 2 (or bottom of a box or support base 2 for receiving the printed circuit board or integrated circuits 4).

The duct can emerge at a second end (E2) on a face F1 of the bottom wall of the base-support and/or at a third end E3 on an external face F3 of one of the walls perpendicular to the bottom wall.

Alternatively, according to a second mode of implementation described later, the conduit (16, 36) and (16, 26) can be formed in a lid 23 or closing wall of the housing L ( ), with a first end E1 arranged facing the sensor, a second end E2 opening onto an edge F4 of the closing wall (and/or a third end E3 on a main external face F3 of the closing wall).

The first mode can include the connection terminal (G, 24, 53) of the second mode and vice versa. The second mode Figures 6-8 may include the connection terminal (5, 7, 14).

The support base 2 and the duct 6 can preferably be formed in one piece, in particular by plastic, metal, natural or synthetic rubber molding, machining or by 3D plastic printing.

In all the examples, the conduit connection terminal (G, 24, 53) or (5, 7, 14) and the support base 2 or 22 can also be manufactured in two separate parts, then the connection terminal can be fixed, in particular by gluing, to the bottom of the support base in order to be secured to the support base.

Alternatively, a connection terminal, connection termination and/or docking 7 for the seal can be formed on an internal side of a fluid connector fixed to a wall. An internal side of the connector has the sensor's docking end, while the other opposite end leads to the outside and is configured to receive an external fluid supply hose.

Thus, the housing can be free of fluid supply hose. The connector is preferably arranged in the housing so as to have its reception end (G, 24, 53) or (5, 7, 14) centered on the input axis of the sensor 25 or the position of the sensor in housing. The connection terminal 5, 7, 14, 16 integrated or fixed firmly on a wall of the box, here connects the sensor 15 directly.

In the example, it is preferred to form the duct 16 and the receiving end 5, 7, 14, 16 of the seal and of the sensor, in the same material as the wall of the case, for example molding or 3D printing, or stream of material.

Thus, once the duct 6, 16 has been made integral with a wall of the box before connection to the sensor, the invention makes it possible to facilitate the connection of the sensor to the duct or the subsequent mounting of the plate 4 in its housing L, without risking pinching or bending a flexible conduit used in the prior art.

It is also possible not to have a predefined position of the plate in the box, the main thing being to connect the sensor and to house the plate in the box. Thus, for example, the plate can be much smaller than its available reception space or have several positions, possible random angular rotations in the plane (P) of its housing. The sensor can be guided in the duct by its protruding supply tube to facilitate connection. Alternatively, there may be centering marks for the supply tube in the mouth of the duct.

The integration of the duct 6, 16 in a wall of the casing facilitates the manufacture of the casing and reduces the number of separate parts to be handled during subsequent final assembly.

According to another characteristic, the method comprises a step of configuring the housing L so that the sensor 15 is placed in the position of connection to the conduit 6, 16, when said plate 4 is inserted into the housing (L) .

In the example figures 1 to 3, the housing can include shims H1 – H4 defining a plane P (or lateral grooves), to position the plate 4 in height in the support base and subsequently the height of the sensor as well.

Plate 4 can also be substantially positioned in the housing by side walls of the support base guiding the plate via its peripheral edge. Thus, thanks to this configuration, the plate can be positioned in height and laterally in its support base 2, so as to place the sensor in the position of connection to the conduit 6, 16. The sensor 15 is here leaned against the plate and its inlet 25 is oriented towards the bottom and external face F1 of the base-support 2.

The duct 6, 16 is fixed and secured to the bottom of the base-support 2. The duct is made in a tubular portion 5 which is formed as an extra thickness of the bottom wall of the base-support (or of the reception box 2 of the electronic plate 4). This tubular extra thickness 5 also reinforces the box at its support base and allows an internal thread at the end E2 (not shown) for screwing an external connector.

The invention has the advantage of facilitating the centering or placement of the inlet 25 of the sensor on the first end E1 of the conduit 16, simply by introducing the plate 4 into its housing (L) via the main inlet of the housing, ( even if the connection of the sensor 15 to the conduit 6, 16 is carried out substantially blind, the introduction of the plate into the housing hiding the sensor placed on the back of the plate).

According to a characteristic of the first mode, the connection is made via a seal 14. It can be chosen from an O-ring, a flat point or any other seal known to those skilled in the art. In the example (figures 2 and 3) it is an O-ring which is placed around the pipe on a receiving and sealing surface 7.

Preferably, the support base 2 may have a surface 7 for centering the seal 14. The surface 7 may be a substantially conical seal centering surface or one with a radius of curvature. The receiving surface 7 may be annular, concave, with an inclined profile or having a radius of curvature substantially conforming to the profile section of the O-ring.

Thus, it is easy to position the O-ring in the reception surface before connecting the sensor. The recessed receiving surface 7 corresponding to the seal, makes it possible to center the seal and to hold it in place during the operation of connecting the sensor to the conduit 16, 6.

Sealing is well ensured, the shape of the O-ring perfectly matching the shape of the reception surface 7.

To the , is shown a printed circuit board 4. The board comprises a pressure sensor, here backed and connected to electrical tracks (not shown) of the printed circuit. In another mode of implementation or embodiment, the sensor can be configured otherwise. It can be with a 45 entry parallel to the plate ( ).

The sensor can be any gaseous or liquid fluid pressure sensor. It can be an atmospheric, pollution, breathalyzer (or alcohol level) sensor, breath measurement sensor for the driver or passengers, allowing the vehicle to be started or not. The sensor may be a carbon or carbon dioxide sensor.

The sensor can be connected to a dedicated 4P microprocessor or microcontroller responsible for measuring and/or controlling an electrical or electronic element of a fixed or mobile device. It may be, for example, a smart portable object or device, such as a mobile phone, a tablet, a laptop computer, an engine sensor, in particular a motor vehicle engine MAP sensor. The 4P component can also control an alarm or perform any action depending on the measured or detected value.

The microcontroller may include a program memory and a data memory for storing values, in particular reference or threshold values.

Plate 4 may include other 4N electrical and/or electronic components. It may include an external 4A power supply connector, a 4C USB, serial and/or parallel communication connector, a touchscreen display or not, an alphanumeric input keyboard, a man-machine interface, a power supply battery or connection to an internal or external battery.

The plate may include a 2G to 5G or Bluetooth TM or WIFI radio frequency communication module in particular to communicate the fluid values measured or detected or to trigger any action. It may include a radiofrequency antenna, for example according to ISO 14443, NFC (Near Field Communication) or RFID.

Other electrical and/or electronic plates can be associated with plate 4 in the box to manage other vehicle elements or devices.

According to a characteristic of this first mode, the gasket 14 is kept compressed by tightening the cover on the support base 2, the cover comprising a wedge 13 resting on the plate 4 during tightening.

To the , is illustrated an example of cover 3 (or wall for closing access to the housing). It has holes 8 on the edge or periphery of the cover to receive assembly screws 18 from the cover to the support base. Along an axis 9, the cover here comprises a peripheral rim intended to partially cover the walls of the base-support 2. It preferably comprises a boss (or wedge) 13, arranged plumb with the area of the sensor or the joint, so as to exert a pressure of compression of the joint between the sensor and a receiving surface 7 of the joint on the base-support 2, by means of a pressure on the plate. The wedge is substantially in the center of the lid but could be off-center.

The example housing assembly is shown in Figures 2 through 3.

Following the installation of the seal 14 in its conical receiving surface 7 and of the plate in its housing (L) (according to the arrows), it suffices to maintain a compression pressure on the seal to ensure a seal. Maintaining the compression of the seal and the leaktight connection of the sensor to the duct is carried out by means of a closing wall of the housing, assembled according to the third arrow (between elements 3 and 4).

The closure wall is in the example a lid 3 ( ) which closes the housing and which presses against the plate 4 via a boss or a wedge 13, in extra thickness of the cover.

The shim is preferably centered directly above the sensor area and the O-ring.

The base-support 2 can be assembled to the lid 3 by screws 18 placed at the periphery of the lid.

The shim, the thickness of the housing and the thickness of the seal can be calibrated and arranged (or configured) together so that a (full) screwing in of the cover, using the screws 18, compresses the seal sufficiently 14.

The invention has the advantage of using an existing sensor on the market. It can for example use the absolute pressure sensor, MPXH6115AC6U or MPXH6115AC6U from NXP.

The sensor may include a tubular inlet 25. This inlet 25 is normally intended to receive a tube or flexible conduit which slips over the tube. In the example, the tube 25 may not be tight inside the duct 16, 6. This tube may or may not be used to guide the plate and the sensor in the duct 16 and in the O-ring 14.

The sensor has a bearing surface against the seal, located at the base of the inlet tube, and which makes it possible to apply a compression pressure on the seal 14 for sealing the connection of the sensor to the conduit 6, 16 .

Alternatively, the invention can dispense with the sensor inlet tube 25, the inlet can be materialized simply by an orifice at the level of the sensor body or of the bearing surface of the seal on the sensor.

The gasket here is fitted loosely around tube 25, however it can be fitted with a tight fit around tube 25 to effect assembly of the plate into the housing by placing the gasket first around the tube rather than into the surface reception 7.

On the , there are openings 11, 12 corresponding respectively to a location of the power supply 4A and communication 4C connectors of the printed circuit board 4.

To the , the case is completely assembled. One observes the possible presence of a cover 20 of conduit 16 (closing the conduit), divisible around a peripheral pre-cut C. This cover 20 closes temporarily or definitively (according to the use of the box) an access of the conduit 16 by the rear face F1 of the case, opposite the front face located on the side of cover 3.

If the user wishes to access conduit 16 from the rear face, the cover can be removed. A plug B can block the duct 26 opening out on a lateral side of the case.

Alternatively, the lid may not be necessary, the two ducts opening out both on the rear face F1 (end E3) and on one side F2 (end E2), the user can place the plug B on the duct 6 or 16 not used (or E1 or E2 end).

However, in the case where by default, conduit 6 and end E2 are used via side F2 of the box, the user has nothing to do if cover 20 is in conduit 16 leading to rear face F1.

The invention has the advantage of using existing sensors and existing electronic plates 4, without the disadvantages of assembly, in particular pinching of a flexible conduit. The sensors can tightly connect each integrated conduit to the box without the addition of flexible conduit.

The layout of the may be different if done in reverse. For example, the sensor can be mounted on the opposite side of the plate (tube 25 to the cover) and the conduit 6, 16 and the gasket receiving surface, made in the connection terminal of the cover instead of the base -bracket 2.

In Figures 4 and 5, the invention illustrates a second embodiment of the housing 1B. The box 1B comprises a support base 22 in the form of a case and a side wall 23 for closing the case (substantially equivalent to the cover 3 of the previous mode).

The electronic plate 4 differs from the previous one by a sensor 35, different from the previous one and which, moreover, is fixed at one end of the plate instead of a substantially central zone of the plate. This sensor 35 is leaned against the plate but it has an inlet tube 45 with an axis parallel to the main plane of the plate (rather than an inlet 25 perpendicular to the plate in the previous mode). In addition, this sensor here does not have a support surface around the inlet tube 45. Such sensors, with an inlet parallel to the plane of the plate, can include the absolute pressure sensor, MPX2200AP from the company NXP.

This sensor can also be intended in the prior art exclusively to receive a flexible conduit pushed onto the inlet tube 45. No other use without a flexible conduit is known.

The wall (or cover) 23 comprises, as before, at least one duct 26, 36 intended to connect the sensor 35 and opening out either on a narrow face F3 of the box (in the extension of the plate), or on a main rear face F4 perpendicular to the main plane of the plate.

The wall also has an internal groove or groove (G) around the conduit 36 to receive an O-ring 24. A protrusion 53 of material from the cover 23 may be necessary to accommodate the internal groove (G).

The entrance to conduit 36 may include a chamfered mouth to facilitate placement of the seal in the groove and to guide tube 45 of sensor 35 during assembly of the assembly. The tube 45 of the sensor 35 can be slightly tapered to facilitate its introduction and sealing in the conduit 26.

Assembly is carried out as follows. The seal 24 is previously inserted into its groove or groove (G). Then, the electronic plate 4 is introduced into its housing in the base-support (or case) 22, up to the stop at the bottom of the case, by a side access 17 of the case (arranged on the right side on the or 5). The housing (L) is also configured (in particular with the height wedges H5-H8 or side slides) so that the sensor 35 is placed in the position of connection to the conduit 26 (and/or 36), during the insertion of said plate 4 in the housing (L).

The connection to at least one of the ducts (or both) is made by bringing the cover 23 towards the case so that the tube 45 of the sensor penetrates inside the duct 36 and threads the seal 24. The joint is dimensioned so as to ensure sealing simply by the contact and tight assembly on the tube 45 and the internal groove (G).

The tightness of the duct, with respect to the fluid brought to the sensor via the duct, is ensured as long as the cover (or the wall) 23 for closing the housing is held in place. Screws (similar to that 18 of the previous mode) can be used in holes (illustrated here by their axis 9) to fix the cover.

To the , is shown a partial view of the electronic plate corresponding to the in the assembly position with the cover already having the seal in place in its groove.

An assembly procedure may be as follows. The sensor (on the plate) can be introduced into the duct fitted with the gasket and made in the cover 23. Then the plate 4, held together with the cover, is slid into the housing of the case 22 until it stops.

Thus the invention makes it possible to avoid, also in this mode, any pinching of a flexible conduit of the prior art.

Assembly is easy as well as disassembly, for example to test a component or replace it.

As before, a lid (not shown) can temporarily block one of the ducts 26, 36. The boxes can provide a single duct or both for mounting configurations of the fluid feeds.

In each mode, the ducts 6, 16, 26, 36 may include at their external inlet E2, E3 in the housing, a junction configuration allowing an inlet (or supply of fluid). For example, the fluid inlet junction configuration may include internal (or even external) threading or other fluid junction means. The fluid inlet may be an end piece protruding outside the casing to make it possible to fix a threaded end piece, in particular metal, for supplying fluid.

Claims (10)

Method of manufacturing an electronic housing (1A, 1B) with a fluid sensor (15, 35), said housing comprising walls (2, 3, 22, 23) defining an interior housing (L), one of the walls (3, 23) being removable and closing a main access (17) to the housing; an integrated circuit board (4), placed in said housing and carrying said fluid sensor (15, 35) having a fluid inlet (25, 45); a fluid supply conduit (6, 16, 26, 36) comprising a first end (E1) connected to the sensor and a second end (E2, E3) opening outside the housing; characterized in that it comprises a step of arranging said first end of the supply duct on one of the walls (2, 23) of the casing. Method according to the preceding claim, characterized in that it comprises a step of configuring the housing (H1-H8) so that the sensor (15, 35) is placed in the connection position during the insertion of the said plate (4) in the housing (L). Method according to one of the preceding claims, characterized in that the said conduit (6, 16, 26, 36) for supplying fluid is formed in or fixed to one of the said walls (23) of the casing. Method according to one of the preceding claims, characterized in that a connection of the sensor to the pipe is kept tight by means of a compression of a seal (16, 24) carried out with the aid of a wall (3, 23) closing the housing. Method according to the preceding claim, characterized in that the seal (14) is kept compressed by tightening the lid on the support base (2), the lid comprising a wedge (13) resting on the plate (4) during Tightening. Electronic housing (1A, 1B) with fluid sensor (15, 35) comprising walls (2, 22) defining a housing (L) inside the housing; an integrated circuit board (4), placed in said housing and carrying a fluid sensor (15, 35) having a fluid inlet (25, 45); a fluid supply conduit (6, 16, 26, 36) comprising a first end (E1) connected to the sensor and a second end (E2, E3) opening outside the housing; characterized in that said first end (E1) of the supply duct is arranged on one of said walls (2, 23) of the casing. Electronic box (1A, 1B) according to the preceding claim, characterized in that the said housing (H1-H8) is configured so that the sensor (15, 35) is placed in the connection position when the said plate (4) in the housing (L). Housing according to one of Claims 6 to 7, characterized in that the said conduit (6, 16, 26, 36) for supplying fluid is formed in or fixed to one of the said walls (23) of the housing. Box according to one of Claims 6 to 8, characterized in that it comprises a leaktight connection of the sensor to the duct maintained by means of a compression of a seal (14, 24) carried out by the intermediate a wall (3, 23) closing the housing. Electronic box according to one of Claims 6 to 9, characterized in that the duct (6, 16, 26, 36) is configured to emerge on the bottom (F1) of the box (2) and/or on one of the sides ( F2) of the housing.