阅读说明：本技术 用于车辆温度传感器的保护外壳 (Protective housing for a vehicle temperature sensor ) 是由 G.科普 A.塞尔韦塔兹 D.普拉迪耶 P.库亚塞 于 2020-03-25 设计创作，主要内容包括：本发明涉及用于车辆的发动机的温度传感器(1),包括：-外壳(1),包含电路板(14)并由设置有端子(8)的至少一对(2)导线(3)穿过,所述端子(8)由压接在布置在外壳(1)中的导体(5)上的部分构成,-连接器(101),包括至少一个金属插入件(10),以确保与电路板(14)的电连接,其特征在于,外壳包括用于保持端子(8)的至少一个凸缘(9),端子(8)被折叠。(The invention relates to a temperature sensor (1) for an engine of a vehicle, comprising: -a housing (1) containing a circuit board (14) and crossed by at least one pair (2) of wires (3) provided with terminals (8), said terminals (8) being constituted by portions crimped on conductors (5) arranged in the housing (1), -a connector (101) comprising at least one metal insert (10) to ensure electrical connection with the circuit board (14), characterized in that the housing comprises at least one flange (9) for retaining the terminals (8), the terminals (8) being folded.)

1. A temperature sensor (1) for an engine of a vehicle, comprising:

-a housing (1) containing a circuit board (14) and crossed by at least one pair (2) of wires (3) provided with terminals (8), said terminals (8) being constituted by portions (804) crimped on conductors (5) arranged in said housing (1); connector (101) comprising at least one metal insert (10) ensuring an electrical connection with said circuit board (14),

characterized in that the housing comprises at least one flange (9) for holding the terminal (8), the terminal (8) being folded.

2. The temperature sensor (1) of claim 1, wherein the flange (9) is fixed to the housing (1) via plastic deformation of at least one support column (106) arranged in the housing (1).

3. The temperature sensor (1) of claim 1 or 2, wherein the diameter of the pillar (106) is greater than or equal to 1.5 mm.

4. A temperature sensor (1) according to any of claims 1-3, wherein the flange is made of a fibre-containing material, for example in a content of 45%, the fibre content of the flange being greater than the fibre content of the housing (1).

5. The temperature sensor (1) of any of claims 1 to 4, wherein the flange (9) comprises:

a first portion (801) formed by folding a copper alloy sheet, the first portion of the terminal being folded after insertion into the housing (1),

an axial stopper (803) formed by double folding of a sheet constituting the axial stopper,

a second portion (804) crimped onto the conductor (5),

a third portion (805) crimped to the wire sleeve (6).

6. The temperature sensor (1) of any of claims 1 to 5, wherein the housing (1) comprises a housing (110) for the terminal (8), the cross-section (114) of which is reduced to ensure the stop and guide of the terminal (8).

7. The temperature sensor (1) of any one of claims 1 to 6, wherein a guiding play (J2) having a height (h) is left between the terminal (8) and the flange (9), wherein preferably (J2) equals 0.05mm and (h) equals 3 mm.

8. The temperature sensor (1) of any of claims 1 to 7, wherein the terminal is folded at an angle a selected such that the terminal (8) is always in contact with one side of the flange (9), preferably between 1 and 3 °.

9. A temperature sensor (1) according to any of claims 1 to 8, wherein the support area of the flange (9) is located on the housing (1) such that it remains flat without pivoting.

10. A method for manufacturing a temperature sensor (1) for the engine of a vehicle according to any one of claims 1 to 9, wherein during assembly of the sensor, the terminal (8) is inserted straight into the housing (1) and then folded directly inside using a folding tool.

Technical Field

The present invention relates to a temperature sensor for an engine of a vehicle and a manufacturing method thereof. In particular, the present invention relates to thermocouple sensors.

Background

Temperature sensors comprising thermocouples for measuring high temperatures are widely used in the field of exhaust systems of internal combustion engines. Thermocouples provide relatively high measurement accuracy. That is why they are used in this field where there are high demands on the control of pollutant emissions.

The measurement principle of thermocouples is based on the Seebeck effect (Seebeck effect), which is reflected in the potential difference when two different metal wires are subjected to a temperature difference. The two wires are welded together at a first end to form a hot junction (or hot spot) for measuring the temperature T1 of an environment to be measured, such as the exhaust gas temperature of an exhaust system. The two wires of the thermocouple also each have a second end, each connected to a voltmeter through a cold junction (or cold spot) at a reference temperature T0.

Temperature sensors of this type are known to comprise a Printed Circuit Board (PCB) with an integrated circuit containing a voltmeter. The integrated circuit is an Application Specific Integrated Circuit (ASIC) that is capable of processing the voltage signal to convert it to temperature. It can provide analog or digital output signals and use digital protocols of the SENT (Single Edge Nibbel Transmission) or PWM (pulsed Width modulation) or PSI (peripheral Sensor interface) type.

These prior art temperature sensors typically include a housing containing a printed circuit board to which several terminals are soldered. The terminal is crimped-and possibly welded-onto the metal core of the stranded wire. In the case of thermocouple sensors, this connection is referred to as a cold junction. The metal core of each wire is coated with an insulator. The silicone seal, which is also crimped onto the terminal, ensures a seal between the insulator and the frame, which includes ribs that are re-fused by plastic injection molding during the production process of the housing. The fusion of these ribs with the plastic material of the housing ensures a seal between the frame and the housing.

This type of sensor has several disadvantages. One of the drawbacks is the insufficient tightness of the casing due to incomplete fusion of the ribs in the plastic material of the casing. Another disadvantage is related to the complexity of such sensors, which require complex production and long installation times.

The object of the present invention is therefore to remedy this drawback of the prior art by proposing a temperature sensor that improves the tightness of the housing and the complexity of the sensor.

Disclosure of Invention

To this end, the invention proposes a temperature sensor for an engine of a vehicle, comprising:

a housing containing a circuit board and penetrated by at least one pair of wires provided with terminals constituted by portions crimped on conductors arranged in the housing,

a connector including at least one metal insert to ensure electrical connection with a circuit board,

characterized in that the housing comprises at least one flange for holding the terminal, which is folded.

According to an embodiment of the invention, the flange is fixed to the housing via plastic deformation of at least one support column arranged in the housing.

According to an embodiment of the invention, the diameter of the column is greater than or equal to 1.5 mm.

According to an embodiment of the invention, the flange is made of a fibre-containing material, for example in a content of 45%, the fibre content of the flange being greater than the fibre content of the shell.

According to an embodiment of the invention, the flange comprises:

the first portion of the terminal is folded after being inserted into the housing by folding a portion formed by the copper alloy sheet.

An axial stop formed by double folding of the sheet material constituting it,

a second portion crimped onto the conductor,

a third portion crimped to the wire guide sleeve,

according to an embodiment of the invention, the housing comprises a housing for the terminal, the cross section of which is reduced to ensure the stop and the guidance of the terminal.

According to an embodiment of the invention, a guiding play with a high height is left between the terminal and the flange, which is preferably equal to 0.05mm and equal to 3 mm.

According to an embodiment of the invention, the terminal is folded at an angle α selected so that the terminal is always in contact with one side of the flange, preferably between 1 and 3 °.

According to an embodiment of the invention, the support area of the flange is located on the housing such that it remains flat and does not pivot.

The invention also relates to a method for manufacturing a temperature sensor for an engine of a vehicle according to any one of claims 1 to 10, wherein during assembly of the sensor, the terminals are inserted straight into the housing and then folded directly inside using a folding tool.

Drawings

Further objects, features and advantages of the present invention will be better understood and will become clearer from the following description, given by way of example, with reference to the accompanying drawings, in which:

figure 1 is a depiction of a front view of a temperature sensor according to an embodiment of the present invention with a PCB mounted,

figure 2 is a depiction of a front view of a temperature sensor according to an embodiment of the present invention without a PCB installed,

figure 3 is a schematic diagram of a longitudinal cross-sectional view of a temperature sensor according to an embodiment of the invention,

figure 4 is a front view of a portion of a temperature sensor according to an embodiment of the present invention,

figure 5 is a schematic diagram of a cross-sectional view of a temperature sensor according to an embodiment of the invention,

figure 6 is a schematic diagram of a cross-sectional view of a temperature sensor according to an embodiment of the invention,

figure 7 is a depiction of a front view of a temperature sensor according to an embodiment of the present invention without a PCB installed,

figure 8 is a schematic illustration of a cross-sectional view of a temperature sensor according to an embodiment of the invention without a side cover,

figure 9 is a schematic diagram of a cross-sectional view of a temperature sensor according to an embodiment of the invention having a side cover,

figure 10 is a depiction of a front view of a temperature sensor according to another embodiment of the present invention with a PCB mounted,

figure 11 is a depiction of a front view of a portion of a temperature sensor according to another embodiment of the present invention without a PCB installed,

figure 12 is a schematic illustration of a cross-sectional view of a temperature sensor according to an embodiment of the invention without a side cover,

figure 13 is a schematic view from below of a temperature sensor according to an embodiment of the invention,

FIG. 14 is a complete diagram of a temperature sensor according to an embodiment of the present invention.

Detailed Description

Fig. 1 shows the interior of a temperature sensor 1 for an engine of a vehicle according to the invention.

A vehicle in the context of the present invention means any type of ground vehicle, such as cars and trucks, or aircraft.

The sensor according to the invention shown in fig. 1, 2 and 3 comprises a housing 1 containing a circuit board 14, also called PCB (printed circuit board). The housing 1 is penetrated by at least one pair 2 of wires 3, the wires 3 being fitted with a terminal 8 and a wire sleeve seal 6, both crimped. According to an embodiment of the invention, the material of the housing 1 is a thermoplastic, such as PA66, PA6, PBT, PPS or PPA. The housing 1 is made of a material having a fiber content, for example 30% fibers.

The circuit board 14 is arranged in the housing 1 and rests on several support areas 105. These support regions are formed around the pillars 104, 106. The posts 104, 106 are heat deformed, such as by rivet heads, to ultimately secure the plates. The location of the posts and their diameter are selected to ensure robustness of the support of the plate 14, particularly under vibration. The posts 104, 106, for example, each have a diameter greater than or equal to 2.5 mm. According to an embodiment of the invention, the posts 104, 106 are located between the front third and the middle of the plate in order to limit vibration.

The housing 1 comprises a connector 101 and at least one flange 102 for holding the terminals, with an over-molded insert 11. The connector 101 comprises at least one metal insert 10, for example supported by bronze or brass, ensuring an electrical connection with the circuit board 14.

As shown in fig. 9, 12 and 14, the housing 1 includes a main cover 13. The cover encloses the housing 1, thereby protecting the circuit board 14 from the external environment (moisture, contamination, liquid). The cover 13 is tightly fixed to the housing 1 by bonding, vibration or laser welding.

In the context of the present invention shown in fig. 2, 3 and 12, the flange 9 is fixed to the housing 1 via plastic deformation of at least one support column 106 arranged in the housing 1. According to an embodiment of the invention, the flange is fixed by two support posts 106. According to an embodiment of the invention, the diameter of the post 106 is greater than or equal to 1.5 mm. This ensures sufficient mechanical strength for a tensile load F of 80N on each wire 3.

According to an embodiment of the invention, the post is deformed by changing the plastic material of the post by heating, which is referred to as a rivet head.

According to another embodiment of the invention, the post is deformed by ultrasonic welding, for example between 20 and 30 kHz. The advantage of deformation by ultrasonic welding is a short cycle time, no risk of fouling and no residual play remaining after operation due to shrinkage of the plastic after cooling. To achieve ultrasonic welding, ribs 115 are provided in the housing 1. The ribs 115 shown in fig. 8 are arranged parallel to the support posts 106 to avoid the material of the housing 1 collapsing.

According to an embodiment of the invention, the rim is supported by the fibre-containing material, for example in an amount of 45%. According to an embodiment of the invention, the fibre content of the flange is greater than the fibre content of the shell, thus avoiding collapse of the flange and formation of residual play after operation. The material of the flange may be a thermoplastic material, such as PA66, PA6, PBT or PPA.

As shown in fig. 6 and 7, two support regions 901 receive the molten material of the support columns 106. An empty space 905 is provided between the two support areas 901. This empty space 905 allows the insertion of a tool for pressing the terminal into the base of the housing before the flange 9 is inserted. This ensures repeatable positioning of the terminals 8.

According to an embodiment of the invention, the seal is arranged in the empty space 905 formed by the flange 9 and the housing 1. The sealing element is a one-component or two-component epoxy resin, or a one-component or two-component gel. The seal ensures a complete seal between the conductor 5 and the insulator. Thus, moisture cannot pass through the wire 3 to the measurement probe 15 by capillary action between the strands of the conductor and the insulation. This improves the accuracy and robustness of the product.

According to an embodiment of the invention, the play J3 is provided between the rib 115 and the base 902 of the support 901. The play J3 is, for example, greater than or equal to 0.1 mm.

The flange 9 according to the invention performs two basic functions. First is the precise and repeatable positioning of the ends of the folded terminals 802 in the metallized holes provided in the circuit board 14. Secondly, the tensile strength of the terminal 8 when the wire 3 is subjected to the force F is ensured.

As shown in fig. 4, the terminal 8 includes a first portion 801 formed by folding a copper alloy sheet. This first part of the terminal is folded after insertion into the housing 1. The terminal also includes a chamfered end 802, optionally with a few millimeters of coating deposited. The coating may be a 0.5 to 5 μm sub-layer of nickel (Ni) and 0.5 to 5 μm layer of tin (Sn) to facilitate soldering to the circuit board 14. The folded region of the terminal 8 is free of coating to limit the risk of incipient fracture and to allow the material of the substrate of the terminal 8 to compensate for the low temperature if the terminal 8 forms a thermocouple. The nickel layer (or other conductive metal) on the surface balances the electrical load generated by the thermocouple forming the terminal (CuFe2P/CUNi10), thus offsetting the compensation required. The purpose of the chamfer is to facilitate insertion of the flange 9 after folding.

As shown in fig. 4 and 5, the terminal 8 includes an axial stopper (803) formed by double folding of the sheet constituting it. Which is designed to fix the insertion position of the terminal in its housing 110 in the housing 1. The clear section 114 of the housing 110 is reduced to ensure such a stop on the terminal 8, while facilitating its guidance in a folding tool (not shown).

As shown in fig. 4, 5 and 14, the terminal 8 includes a second portion 804 crimped onto the conductor 5. According to an embodiment of the invention, in the case of a thermocouple sensor, laser welding is performed in order to reduce the risk of electrical contact shrinkage. The second portion 804 has, for example, a nickel coating (Ni) of about 0.5 to 5 μm thick to facilitate laser welding. This second part is also called the cold junction of the thermocouple.

The terminal further comprises a third portion 805 crimped onto the wire guide sleeve 6 for mechanical support thereof. After sleeving, the wires 3 are arranged in pairs 2 and protected by a sheath 7, the sheath 7 being made of, for example, glass fibers and silicone. At the other end of the wire pair is a temperature sensor. The temperature sensor is fixed to a boss 16 of the device or pipe to be measured.

According to an embodiment of the present invention, in the case of a thermocouple sensor, the positive electrode of the terminal is made of low alloy copper such as CuFe2P, and the negative electrode is made of cupronickel such as CuNi 10. This copper alloy in its raw form takes the form of a sheet having a thickness of 0.2 to 0.4 mm.

According to the embodiment of the invention shown in fig. 3 to 5, the housing comprises a chamfer 112 to facilitate insertion of the cannula 6.

In the context of the present invention, when assembling the sensor, the terminal 8 is inserted straight into the housing 1 and then folded directly inside using a folding tool, so that no overmolding is required.

The housing 1 comprises an open space 107 so that a tool for folding the terminal 8 can be introduced into the housing 1. After folding, the tool is retracted and leaves room for the flanges, which will eventually secure the terminals.

In order to ensure both functions of the above-described terminals (end positioning and tensile strength on the circuit board), several geometric parameters and materials are required.

In the context of the present invention, a guiding play J2 having a height h is left between the terminal 8 and the flange 9. According to an embodiment of the present invention, the ratio J2/h is minimized. For example, J2 equals 0.05mm and the height equals 3 mm. Minimizing this ratio facilitates two desired functions.

In the context of the present invention, the terminal is folded at a selected angle α so that the terminal 8 is always in contact with one side of the flange. This angle is for example between 1 and 3 °. The spread of the positioning of the ends of terminals 802 in the metallized holes of circuit board 1401 is minimized due to the preferential contact (privileged contact) that is always on the same side of the flange.

In the context of the present invention, the support area of the flange 9 is located on the housing 1 below the area 901 so that it remains flat without pivoting. For this reason, the play J1 between the flange 9 and the terminal 8 is not zero, for example equal to 0.05 mm.

In the context of the present invention, the area for inserting the terminal 8 into the flange 9 is facilitated at 904 by a chamfer on one side of the flange and a radius on the other side of the flange. In order not to damage the terminal 8, the terminal radius R is chosen large enough, for example 0.9mm for a fold thickness of 0.6 mm. The radius R' on the flange is within the radius of curvature of the terminal 8 in order not to damage it.

In the case of a thermocouple sensor, the air flow is supplied, for example, by the outside air of the vehicle when the housing is not placed in the hood or in the isolation area. In this configuration, one face of the casing is in contact with the engine between 50 ℃ and 150 ℃, and the opposite face is seen to be a flow of cold air between-40 ℃ and 10 ℃. This gradient between the outside of the housing 1 creates a gradient in the housing between the cold junction of the thermocouple 804 and the circuit board 14 containing the elements that measure low temperatures.

To limit this gradient, at least one air chamber 108 is provided between the cold junction 804 and the underside and sides of the housing 1.

According to an embodiment of the invention, a second air chamber 109 is provided between the cold junction and the upper and side faces.

These cavities 108, 109 act as thermal insulation and allow a gain of about 10 ° of the temperature difference for an external gradient of 100 ℃.

As shown in fig. 3, 4 and 5, the first cavity 108 is closed by the side cover 12 to prevent air from flowing into this area. According to an embodiment, the cover 12 is tightly fixed to the housing 1. The side cover 12 is fixed, for example, by ultrasonic welding (20 to 30kHz) with a fast cycle time. For this purpose, energy vectors 1201 are provided on the inner face of the side cover 12 and are fused and mixed with the material of the housing 1.

According to an embodiment of the present invention, the side cover 12 is formed of the same material as the housing 1. The casing 1 comprises internal ribs 117 and support zones 116 formed at the ends of the walls of the casing 1, which allow a balanced welding over the entire periphery of the cover. The internal ribs 117 are arranged in the lower part of the housing 1 below the cold junction 804. The housing comprises at least two holes 118 formed below the housing 1 for draining water that may remain in the first chamber 108.

According to an embodiment of the invention, the housing comprises additional ribs 111, which provide a better rigidity of the housing 1. These additional ribs 111 are arranged in the upper part of the housing 1.

In the context of the present invention, the upper and lower parts of the housing, and generally all references to orientation directions, are defined with respect to the face of the housing 1 including the main cover 13, which is considered to be the upper face of the sensor.

According to another embodiment of the present invention, shown in fig. 6, 7, 8 and 9, the first chamber 108 and the second chamber 109 are coupled to form a single chamber 120. The cavity 120 surrounds the cold junction 804. In this configuration, the housing 1 also includes internal ribs 117 and additional ribs 111, the purpose of which is to strengthen the cold junction and also to balance the welding of the side cover 12.

The scope of the invention is not limited to the details given above, and is susceptible of embodiment in many other specific forms without departing from the field of application of the invention. The present embodiments are therefore to be considered as illustrative and can be modified without departing from the scope defined by the claims.