Temperature sensor with anti-rotation stop

Abstract

The present invention relates to a temperature sensor (1) for a motor vehicle, comprising: a thermistor, two wires (3) connecting the thermistor to an electrical connector, an insulating sheath (5) surrounding the two wires (3), a protective end piece including a closed end in which the thermistor is accommodated, and a fixing device (6) for the insulating sheath (5) to pass through, the fixing device (6) comprising a threaded element (8) and a stopper (10) fixed to the insulating sheath (5), the threaded element (8) being used to be screwed into a threaded hole (7) provided in a vehicle engine interface element (9) to fix the temperature sensor (1) to the engine interface element (9), the stopper (10) surrounding the insulating sheath (5) and being used to provide a seal between the interior and the exterior of the engine interface element (9), the threaded element (8) being rotatable relative to the stopper (10). According to the invention, the stopper (10) comprises at least one lug (11) for being inserted into a slot (12) provided in the engine interface element (9) to prevent the temperature sensor (1) from rotating relative to the engine interface element (9).

Description

Technical Field

[0001] The present invention relates to a temperature sensor, in particular to a temperature sensor for measuring temperatures between -40°C and 1100°C.

[0002] The invention applies in particular to a temperature sensor suitable for measuring the exhaust gas temperature of a motor vehicle.

[0003] The present invention is also applicable to a temperature sensor used in an on-board fuel (ethanol, methane) heating and reforming device of a fuel cell vehicle. Background Art

[0004] These sensors typically include a temperature-sensitive element, such as a thermistor or thermocouple, which is connected by wires to an external electrical / electronic measurement signal utilizing circuitry.

[0005] Such prior art temperature sensors include a thermal component at one end thereof that is exposed to very high temperatures.

[0006] The thermal components include:

[0007] - In the case of a resistive sensor, a sensitive element of thermistor type (PTC (positive temperature coefficient) / NTC (negative temperature coefficient)),

[0008] - In the case of a thermocouple sensor, the hot junction of the thermocouple wires.

[0009] Two wires connect the thermistor to the electrical connector.

[0010] An insulating sheath surrounds the two wires.

[0011] The wires are routed along the protective terminal piece and the insulating sheath so that they can be accessed and powered from outside thereof.

[0012] - In the case of a resistive sensor, the voltage represents the resistance of the thermistor,

[0013] -Or, in the case of a thermocouple sensor, the voltage is a function of the temperature difference between its two ends.

[0014] To this end, the electrical wires are connected to an electrical connector which itself is connected to the vehicle's electrical / electronic circuits.

[0015] The temperature sensor includes a fixture through which an insulating sheath passes. The insulating sheath may be surrounded by a protective metal packaging material.

[0016] The fixing device includes a threaded element for being screwed into a threaded hole provided in the vehicle engine interface element so as to fix the temperature sensor thereto.

[0017] The fixing device also includes a stopper fixed on the insulating sheath.

[0018] A stopper surrounds the insulating jacket and is used to provide a seal between the interior and exterior of the engine interface component.

[0019] Particular difficulties arise when the temperature sensor has a curved sheath that requires a set orientation relative to the vehicle engine interface component.

[0020] Furthermore, during assembly of this type of bent temperature sensor with the engine interface component, the temperature sensor is not always properly oriented and there may be electrical connection problems if the temperature sensor connector is not in the correct position or is far away from the vehicle connector to which it is connected. Furthermore, during assembly and tightening of the sensor on the vehicle, the sensor has a tendency to rotate.

[0021] Difficulty finding the correct orientation of the temperature sensor can result in difficult and time-consuming installation. Summary of the invention

[0022] It is therefore an object of the present invention to alleviate these disadvantages of the prior art by providing a temperature sensor which is easier to install and which is prevented from rotating once the temperature sensor is secured to the engine.

[0023] The present invention relates to a temperature sensor for a motor vehicle, comprising:

[0024] - Thermistor,

[0025] - Two wires to connect the thermistor to the electrical connector,

[0026] - an insulating sheath, surrounding the two wires,

[0027] - a protective end piece comprising a closed end in which the temperature-sensitive element is housed, and

[0028] - A fixing device through which the insulating sheath passes, the fixing device comprising a threaded element and a stopper, the threaded element being used to be screwed into a threaded hole provided in the vehicle interface element so as to fix the temperature sensor to the engine interface element, and the stopper being fixed to the insulating sheath. The stopper surrounds the insulating sheath and is used to provide a seal between the interior and the exterior of the engine interface element. The threaded element is rotatable relative to the stopper.

[0029] According to the present invention, the stopper comprises at least one lug for being inserted into a slot provided in the engine interface component to prevent the temperature sensor from rotating relative to the engine interface component.

[0030] The lug is formed in one piece with the stopper. This allows the two functions of sealing and preventing rotation to be achieved with a single component, unlike the prior art which uses two components: one for sealing and one for preventing rotation.

[0031] The lug is positioned laterally on the stopper so as to protrude relative to the insulating sheath.

[0032] The stopper comprises a tubular portion which is fixed to and surrounds the insulating sheath. The tubular portion of the stopper of the fixture is inserted into the threaded element of the fixture. Thus, the threaded element of the fixture surrounds the tubular portion of the stopper.

[0033] The tubular portion of the stopper is extended by a ring at the lower end. The ring extends radially and perpendicularly relative to the tubular portion and is used to provide a seal between the threaded hole of the engine interface component and the exterior. The ring includes an inner surface and an outer surface, the inner surface being used to abut against the inner edge of the threaded hole surrounding the engine interface component, and the outer surface being used to form a stopper for the threaded element of the fixture.

[0034] The lugs form tabs extending from the ring of the stopper in a direction perpendicular to the tubular portion.

[0035] The lugs may be curved. The lugs are curved in order to induce a change in plane in a single identical part obtained by pressing.

[0036] According to another embodiment, the stopper comprises two lugs.

[0037] The two lugs abut and form an angle with each other.

[0038] The present invention also provides a temperature sensor that is easier to install, thereby reducing installation time.

[0039] The temperature sensor is prevented from rotational movement relative to the engine interface element.

[0040] When the temperature sensor includes a bent insulating sheath, the indexed stop allows the temperature sensor to be mounted on the engine interface component in a constant orientation, simplifying installation.

[0041] Thus, the stopper provides the functions of sealing, indexing and preventing rotation. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The features of the present invention will be described in more detail with reference to the accompanying drawings, in which:

[0043] Figure 1 depicts a perspective view of a temperature sensor according to one embodiment of the present invention prior to installation on an engine interface component;

[0044] Figure 2is a perspective view of a temperature sensor mounted on an engine interface component;

[0045] Figure 3 is a perspective view of the temperature sensor alone without the threaded element;

[0046] Figure 4 A longitudinal section through the stop is depicted;

[0047] Figure 5 is a perspective view of a temperature sensor according to another embodiment of the present invention;

[0048] Figure 6 is a perspective view of the temperature sensor alone without the threaded element. DETAILED DESCRIPTION

[0049] Figure 1 A perspective view of a temperature sensor 1 according to one embodiment of the present invention is depicted before being mounted on an engine interface component 9 .

[0050] Temperature sensors are used to measure the temperature of motor vehicle exhaust gases. The sensor is also used to measure the temperature of onboard fuel (ethanol, methane) heating and reforming devices in fuel cell vehicles.

[0051] Temperature sensors are mainly used to measure the so-called average temperature between -40°C and 1100°C.

[0052] The temperature sensor 1 comprises at one end a thermal component which is exposed to very high temperatures.

[0053] The thermal component contains:

[0054] - In the case of a resistive sensor, a sensitive element of thermistor type (PTC (positive temperature coefficient) / NTC (negative temperature coefficient)),

[0055] - In the case of a sensor, the hot junction of the thermocouple wire.

[0056] The sensor also comprises two wires 3 connecting the thermistor or thermal junction to an electrical connector (not shown), an insulating sheath 5 surrounding the two wires 3, and a protective end piece 4 comprising a closed end 2 in which the thermistor or thermal junction is housed.

[0057] The electrical connector is connected to an electronic control unit (not shown) of the vehicle.

[0058] The insulating sheath 5 may be partially or completely surrounded by a protective metal packaging material.

[0059] The protective packaging material has a longitudinally extending tubular overall shape.

[0060] Protective packaging materials such as Inconel , Inconel or Inconel Made of super alloy.

[0061] The temperature sensor 1 comprises a fixing device 6 through which the insulating sheath 5 passes.

[0062] The fixing device 6 includes a threaded element 8 and a stopper 10 . The threaded element 8 is used to be screwed into a threaded hole 7 provided in a vehicle engine interface element 9 so as to fix the temperature sensor 1 thereto. The stopper 10 is fixed to the insulating sheath 5 .

[0063] The engine interface element 9 is mounted on a wall 23 of the vehicle duct.

[0064] The wall 23 defines the environment in which the temperature is to be detected. For example, the wall 23 may be the wall of a duct of a combustion exhaust gas emission system.

[0065] The threaded element 8 comprises a nut 19 at its upper portion 20 to allow the threaded element 8 to be screwed into or out of the threaded hole 7 of the engine interface element 9 using a tool such as a wrench.

[0066] The threaded element 8 comprises, at its lower end 21 , a lower surface which abuts against the stop 10 .

[0067] The stopper 10 surrounds the insulating sheath 5 and serves to provide a seal between the interior and exterior of the engine interface component 9 .

[0068] The threaded element 8 is rotatable relative to the stop 10 in order to allow a threaded connection.

[0069] The threaded element 8 includes a central passage through which the insulating sheath 5 can pass. Figure 4 As shown, the stopper 10 further comprises a central passage 22 through which the insulating sheath 5 can pass.

[0070] The fixture 6 may be made of stainless steel, such as 304, 316L or 316Ti.

[0071] The thermal element may be, for example, a thermistor, which is a passive element made of semiconductor material whose resistance varies with temperature.

[0072] Thermistors can be of the negative temperature coefficient (or NTC) type, when the resistance decreases with increasing temperature, or in the opposite case, of the positive temperature coefficient (or PTC) type, such as thermistors made of platinum.

[0073] Alternatively, the thermal element may be a thermocouple hot junction.

[0074] According to the present invention, the stopper 10 comprises at least one lug 11, which is used to be inserted into a slot 12 provided in the engine interface element 9 to prevent the temperature sensor 1 from rotating relative to the engine interface element 9. Figures 1 to 4 shown.

[0075] Figures 1 to 4 An embodiment is shown in which the stop 10 comprises a single lug 11 .

[0076] In order to simplify the figures, the threaded element 8 is not Figures 2 to 6 Shown in.

[0077] The lug is created as a lug with a stop. That is, the lug and the stop are a single piece. The lug 11 and the stop 10 are continuous material, i.e. made of the same material.

[0078] The lug 11 is positioned laterally on the stopper 10 so that the lug protrudes relative to the insulating sheath 5, as shown in FIG. Figure 3 shown.

[0079] The stopper 10 comprises a tubular portion 18 of circular cross section, which is fixed to the insulating sheath 5 and surrounds the insulating sheath 5. The stopper 10 is prevented from rotating relative to the insulating sheath 5.

[0080] like Figure 1 As shown, the threaded element 8 of the fixing device 6 surrounds the tubular portion 18 of the stopper 10 of the fixing device 6 when the threaded element 8 is screwed into the threaded hole 7 of the engine interface element 9 and when not screwed in.

[0081] The threaded element 8 is rotatable relative to the stopper 10 .

[0082] The tubular portion 18 of the stopper 10 extends through the ring 13 at the lower end 14. The tubular portion 18 of the stopper 10 and the ring are made in one piece.

[0083] The ring 13 extends radially and substantially perpendicularly relative to the tubular portion 18 and in a plane different from the sealing plane and is intended to provide a seal between the threaded hole 7 of the engine interface element 9 and the outside of the engine wall 23 .

[0084] The ring 13 comprises an inner surface 15 for abutting or contacting an edge 17 surrounding the threaded hole 7 of the engine interface component 9 .

[0085] The ring 13 comprises an outer surface 16 intended to form a stop for the threaded element 8 of the fixing device 6 .

[0086] In other words, the tubular portion 18 of the stopper 10 is inserted into the hole of the threaded element 8 held by the ring 13 .

[0087] The lower surface at the lower end 21 of the threaded element 8 abuts against the outer surface 16 of the ring 13 of the stopper 10 .

[0088] The lugs 11 form tabs extending from the ring 13 of the stop 10 in a direction perpendicular to the tubular portion 18 .

[0089] The width of the lug 11 is slightly smaller than the width of the slot 12 of the engine interface component 9 so as to allow the lug to enter the slot.

[0090] The lug 11 is curved. The lug 11 extends from the ring 13 and a first portion 24 turns upwards towards the tubular portion 18 and extends through a second portion 25 extending perpendicularly to the tubular portion 18. A hollow 26 is formed between the tubular portion 18 and the second portion 25 of the lug 11.

[0091] The lower surface of the lower end 21 of the threaded element 8 is received in the hollow portion 26 .

[0092] The insulating sheath 5 is curved. The insulating sheath 5 comprises a first portion 27 comprising the thermal element and the protection terminal 4 and a second portion 28 connected to the connector.

[0093] In this example, the second portion 28 is perpendicular to the first portion 27 .

[0094] The second portion 28 and the first portion 27 are separated by a bend 29 .

[0095] The fixing device 6 is located between the thermal element and the bent portion 29 .

[0096] The slot 12 of the engine interface component 9 extends parallel to the first portion 27 and extends from an outer edge 30 of the engine interface component 9 to an inner edge 17 of the engine interface component 9 .

[0097] When the temperature sensor 1 is inserted into the threaded hole 7 of the engine interface element 9 , the lug 11 of the stopper is inserted into the slot 12 of the engine interface element 9 and slides along the slot until the inner edge 17 .

[0098] The lug 11 has a predetermined orientation relative to the second portion 28 of the temperature sensor 1 .

[0099] exist Figure 2 In the example shown in FIG. 5 , the lug 11 and the second portion 28 of the temperature sensor 1 are oriented substantially in parallel and in opposite directions.

[0100] This orientation always remains constant when the temperature sensor 1 is mounted on the engine interface element 9. It is not possible to orient the temperature sensor 1 differently. Therefore, the operator cannot make mistakes during the installation process.

[0101] Furthermore, the lug 11 is prevented from rotating in the slot 12 of the engine interface element 9 , thereby preventing the temperature sensor 1 from rotating when the vehicle is in use.

[0102] The threaded element 8 is screwed into the threaded hole 7 of the engine interface element 9 and tightened therein, so that the stopper 10 is tightened onto the inner edge 17 of the engine interface element 9 .

[0103] The ring 13 of the stopper 10 is compressed between the lower end 21 of the threaded element 8 and the inner edge 17 of the engine interface element 9 , thereby forming a seal between the threaded hole 7 and the outside of the engine wall 23 .

[0104] Figure 5 and 6 A temperature sensor 1 according to another embodiment of the invention is depicted, the stopper 10 of which comprises two lugs 11 .

[0105] The two lugs 11 are adjacent and form an angle with each other. The two lugs 11 form a "V" shape and extend from the ring 13.

[0106] At the same time, the engine interface element 9 includes two adjacent slots 12 which form an angle with respect to each other, and the two lugs 11 of the stopper 10 can be inserted into the corresponding slots 12 .

[0107] The angle between the two lugs serves to prevent mistakes when several sensors of the same type are assembled very close to each other.

[0108] For example:

[0109] - The angle of the first sensor is 30°,

[0110] - The angle of the second sensor is 60°,

[0111] - The angle of the third sensor is 90°,

[0112] -etc.

[0113] Therefore, during installation, it is not possible to mount the second sensor on the interface of the first sensor, and so on.

[0114] The angle within the gap can be defined to be any angle between 0° and 180°.

[0115] -0° corresponds to a single lug,

[0116] -180° corresponds to no poka-yoke.

[0117] In the range of 180° to 360°, the range of 0° to 180° is repeated by symmetry.

[0118] Taking into account the angular width of the lug (15° to 20°), and the spread when assembled (5°), a range of positions in 30° increments can be considered, providing 5 possible positions: 30°, 60°, 90°, 120° and 150°.

Claims

1. A temperature sensor (1) for a motor vehicle, comprising: Thermal element, Two wires (3) connecting the thermistor to an electrical connector, an insulating sheath (5) surrounding the two wires (3) and the thermal element, and A fixing device (6) for the insulating sheath (5) to pass through, the fixing device (6) comprising a threaded element (8) and a stopper (10), the threaded element (8) being used to be screwed into a threaded hole (7) provided in an engine interface element (9) of the vehicle so as to fix the temperature sensor (1) to the engine interface element (9), the stopper being fixed to the insulating sheath (5), and the stopper (10) surrounding the insulating sheath (5) and being used to provide a seal between the interior of the engine interface element (9) and the exterior of the engine interface element, the threaded element (8) being rotatable relative to the stopper (10), Features: The stopper (10) comprises: at least one lug (11) for being inserted into a slot (12) provided in the engine interface element (9) to prevent the temperature sensor (1) from rotating relative to the engine interface element (9); and a tubular portion (18) fixed to the insulating sheath (5) and surrounding the insulating sheath (5), the tubular portion (18) of the stopper (10) of the fixture (6) being inserted into a threaded element (8) of the fixture (6), The tubular portion (18) of the stopper (10) extends through a ring (13) at the lower end (14), the ring (13) extending radially relative to the tubular portion (18) and used to provide a seal between the threaded hole (7) of the engine interface element (9) and the exterior of the engine interface element, the ring (13) comprising an inner surface (15) and an outer surface (16), the inner surface (15) being used to abut against an inner edge (17) surrounding the threaded hole (7) of the engine interface element (9), the outer surface (16) being used to form a stopper for the threaded element (8) of the fixing device (6).

2. The temperature sensor (1) according to claim 1, characterized in that The lug (11) is formed integrally with the stopper.

3. The temperature sensor (1) according to claim 1 or 2, characterized in that The lug (11) is positioned laterally on the stopper (10) so as to protrude relative to the insulating sheath (5).

4. The temperature sensor (1) according to claim 1, characterized in that The lugs (11) form tabs extending from the ring (13) of the stop (10) in a direction perpendicular to the tubular portion (18).

5. The temperature sensor (1) according to claim 4, characterized in that The lug (11) is curved.

6. The temperature sensor (1) according to any one of claims 1 to 5, characterized in that The stopper (10) comprises two lugs (11).

7. The temperature sensor (1) according to claim 6, characterized in that The two lugs (11) are adjacent and form an angle with each other.

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