Claims:We claim,
1. A cost-effective compact temperature sensor (100) comprising of temperature sensor module (102) with NTC thermistor leads (116) and temperature sensor bulb (118), an outer brass body (104), a hexagonal part (106) and an integrated coupler (108);
characterized in that
the temperature sensor (100) has the said integrated coupler (108) and the said hexagonal part (106) are made of plastic outer body (110);
and the leads of the NTC thermistor (116) are welded with terminals (112) of the coupler (108) through resistance welding and the terminal holder (114) holds the welded terminal part together;
and a plastic tube (120) covers and holds the NTC thermistor leads (116) together and protects from external pressure and damage during assembly process;
and the outer brass body (104) with a thread (122) covers the said plastic tube (120) and the NTC thermistor leads (116).

2. The sensor as claimed in claim 1, wherein terminals (112) are held together by the terminal holder (114) to form the terminal subassembly (124) and the terminal holder (114) also acts as a partition to keep the terminals (112) and leads of the thermistor (116) separate from each other to prevent short circuit issues.

3. The sensor as claimed in claim 1, wherein the leads of the NTC thermistor (116) are welded to the terminals (112) to form the temperature sensor with terminal subassembly (126).

4. The sensor as claimed in claim 1, wherein the plastic tube (120) is then inserted on the NTC Thermistor leads (116) to protect the leads (116) from external pressure and damage to form the plastic tube subassembly (128).

5. The sensor as claimed in claim 1, wherein the outer brass body (104) having the thread portion (122) is insert moulded to the tube (120) to form the outer brass body sub assembly (130).

6. The sensor as claimed in claim 1, wherein the brass body subassembly (130) is insert moulded with plastic material to cover the terminals (112) such that the plastic material covers the terminal holder (114) uniformly with moulded plastic and is merged with the Brass body (104) to create the hexagonal part (106) and coupler part (108) that together form the plastic body (110).

7. The sensor as claimed in claim 1, wherein the hexagonal part (106) incorporated with the plastic body has the required specifications of tightening torque similar to the conventional temperature sensor.

8. The sensor as claimed in claim 1, wherein the terminals (112) are placed at an offset from the center in the plastic body (110) to optimize the use of plastic during moulding. (It Is not offset it is in center)

9. The sensor as claimed in claim 1, wherein there are two slots on the outer surface of the brass outer body (104) to prevent rotation of the Plastic body (110) along with the hexagonal part (106) and brass outer body (104) and to achieve the tightening specification.
, Description:FIELD OF INVENTION
The present invention in general relates to a temperature sensor and more particularly it relates to a compact, lightweight and cost-effective temperature assembly to detect and measure the temperature at various locations in a vehicle.
BACKGROUND OF THE INVENTION

Modern automotive engines typically rely on numerous engine parameters for correct engine operation. Optimum engine parameters are generally stored in the memory of an engine controller. Sensors on the engine are used to sense actual engine parameters while the controller compares these sensed values to the stored optimum valves. As a result, it is important that a reliable, repeatable sensor be installed in the engine having little engine-to-engine variation, such that a correct engine operating parameter is sensed.
Various sensors for sensing the temperature of a rigid body, such as a cylinder head of an internal combustion engine, have been developed. The sensor must be in intimate thermal contact with the rigid body to sense the proper temperature. To provide good thermal conductivity, some sensor designs utilize a spring such that, when installed, the spring provides a force to bias the sensor into contact with the rigid body to establish adequate thermal conductivity. Still other sensor designs rely on the mounting threads to provide the conductive path between the rigid body and the sensor. However, the previous temperature sensors have not provided an accurate reading of the temperature parameters in the cylinder head of an engine.
The conventional temperature sensors are heavy and difficult to manufacture. Further they use materials which increases the cost of production. There is therefore felt a need to provide a compact yet effective temperature sensor that overcomes these drawbacks.

OBJECTIVES OF THE INVENTION
Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows:
It is an object of the present disclosure to ameliorate one or more problems of the prior art or to at least provide a useful alternative.
An object of the present invention is to provide a compact temperature sensor for the engine of a vehicle.
Another object of the present invention is to provide the compact temperature sensor that has reduced weight and is easy to manufacture.
Another object of the present invention is to provide the compact temperature sensor that is cost effective.
Another object of the present invention is to provide the compact temperature sensor with hexagonal part incorporated with the plastic body that has the required specifications of tightening torque similar to the conventional temperature sensor.
Another object of the present invention is to provide the compact temperature sensor that eliminated the harness wires and integrates the coupler along with the hexagonal part with the moulding.
Other objects and advantages of the present disclosure will be more apparent from the following description, which is not intended to limit the scope of the present disclosure.
SUMMARY OF THE INVENTION
Before the present invention is described, it is to be understood that present invention is not limited to particular methodologies and materials described, as these may vary as per the person skilled in the art. It is also to be understood that the terminology used in the description is for the purpose of describing the particular embodiments only, and is not intended to limit the scope of the present invention.
The present invention describes a compact temperature sensor for detecting and measuring the temperature at various locations in a vehicle. Typically, the temperature sensor assembly is used to detect the temperature at the cylinder head of the vehicle engine and the engine oil temperature. The temperature sensor generally includes an NTC (Negative Thermistor Coefficient) type Thermistor which detect temperature of its surrounding and gives readings in the form of resistance to the ECU.
According to an aspect of the present invention, the temperature sensor has the integrated coupler and the hexagonal part made of plastic body. The leads of the NTC thermistor are welded with the terminals of the coupler and the terminal holder holds the welded terminal part together. The terminals are joined to the NTC thermistor leads through resistance welding. A plastic tube covers and holds the NTC thermistor leads together and protects from external pressure and damage during assembly process. An outer brass body with the thread portion covers the tube which protects the NTC Thermistor.
According to the embodiment of the invention, the brass body subassembly is insert moulded with plastic material to cover the terminals. The plastic material covers the terminal holder uniformly with molded plastic and is merged with the Brass body to create the hexagonal part and coupler part that together form the plastic body. The brass body has anti-rotation slot to achieve the tightening specification. In the insert moulding process, the hexagonal part is incorporated in the plastic body. The hexagonal part incorporated with the plastic body has the required specifications of tightening torque similar to the conventional temperature sensor. Some part of the plastic tube portion is merged with the plastic body during moulding.

BRIEF DESCRIPTION OF THE DRAWINGS
A complete understanding of the present invention may be made by reference to the following detailed description which is to be taken in conjugation with the accompanying drawing. The accompanying drawing, which is incorporated into and constitutes a part of the specification, illustrates one or more embodiments of the present invention and, together with the detailed description, it serves to explain the principles and implementations of the invention.
FIG.1 is the front perspective view of the temperature sensor according to an embodiment of the invention;
FIG.2 is the exploded view of the temperature sensor as shown in FIG.1 according to the embodiment of the invention;
FIG.3 is the cross-sectional view of the temperature sensor as shown in FIG.1 according to the embodiment of the invention;
FIG.4 is the alternate cross-sectional view of the temperature sensor as shown in FIG.1 according to the embodiment of the invention;
FIG. 5(A-E) are the perspective views of the assembly process of the temperature sensor as shown in FIG.1 according to the embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

Before the present invention is described, it is to be understood that this invention is not limited to particular methodologies described, as these may vary as per the person skilled in the art. It is also to be understood that the terminology used in the description is for the purpose of describing the particular embodiments only, and is not intended to limit the scope of the present invention. Throughout this specification, the word “comprises”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps. The use of the expression “at least” or “at least one” suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the invention to achieve one or more of the desired objects or results.

LIST OF REFERENCE NUMERALS:

Sr. No. Description of the part
100 Temperature sensor
102 Temperature sensor module
104 Brass outer body
106 Hexagonal part
108 Coupler
110 Plastic body
112 Terminals
114 Terminal holder
116 NTC Thermistor
118 Temperature sensor bulb
120 Plastic tube
122 Thread (outer body)
124 Terminals sub- assembly
126 Temperature sensor with terminal Sub-assembly
128 Plastic tube sub-assembly
130 Brass outer body sub-assembly

The present invention describes a compact temperature sensor (100) for detecting and measuring the temperature at various locations in a vehicle. Typically, the temperature sensor assembly is used to detect the temperature at the cylinder head of the vehicle engine and the engine oil temperature. The temperature sensor (100) generally includes an NTC (Negative Thermistor Coefficient) type Thermistor which detect temperature of its surrounding and gives readings in the form of resistance to the ECU. The Operating & Storage Temp. Range of the thermistor is -55 ºC TO 250 ºC, its response Time : 60~80 sec with accuracy of ±5 %, and its body Material is Brass. Alternatively, other thermistor types can also be used, however for automotive purposes, generally NTC type thermistor is used.

According to an embodiment of the invention, FIG.1 is the front perspective view of the temperature sensor. The temperature sensor(100) comprises of a temperature sensor module (102), an outer brass body (104) covering the thread (outer body) (122) and temperature sensor module (102), a hexagonal part (106) and a coupler (108).
According to the embodiment of the invention, FIG.2 is the exploded view of the temperature sensor as shown in FIG.1. The temperature sensor (100) has the integrated coupler (108) and the hexagonal part (106) made of plastic body (110), specifically nylon 66 30% glass field plastics. The leads of the NTC thermistor (116) are welded with the terminals (112) of the coupler (108) and the terminal holder (114) holds the welded terminal part together. The terminals (112) are joined to the NTC thermistor leads (116) through resistance welding. A plastic tube (120) covers and holds the NTC thermistor leads (116) together and protects from external pressure and damage during assembly process. An outer brass body (104) comprising of the temperature sensor module (102) and the thread (122) covers the tube (120) which protects the NTC Thermistor (116).
According to the embodiment of the invention, FIG.3 is the horizontal cross-sectional view of the temperature sensor as shown in FIG.1. As can be seen, the integrated coupler (108) and the hexagonal part (106) are made of plastic outer body (110). The terminals (112) of the coupler (108) are welded to the leads of the NTC Thermistor (116). The temperature sensor module (102) comprising of the leads of the NTC thermistor (116) and the temperature sensor bulb (118) are protected by a tube (120) which is further covered by the outer brass body (104). The thread (122) is also made of the outer brass body (104).

According to the embodiment of the invention, FIG.4 is the vertical cross-sectional view of the temperature sensor as shown in FIG.1. As can be seen, the integrated coupler (108) and the hexagonal part (106) are made of plastic outer body (110). The terminals (112) of the coupler (108) are welded to the leads of the NTC Thermistor (116). The temperature sensor module (102) comprising of the NTC thermistor (116) and the temperature sensor bulb (118) are protected by a tube (120) which is further covered by the outer brass body (104). The thread (122) is also made of the outer brass body (104). The terminals (112) are placed at an offset from the center in the plastic body (110). This is to optimize the use of plastic during moulding. To prevent rotation of the plastic outer body (110), there are two slots on the outer surface of the Brass Outer Body (104). The temperature sensor module (102) is covered by brass material as it has good heat conductivity and the thread (122) is also made of brass to sustain the frequent wear and tear.

According to the embodiment of the invention, FIG. 5(A-E) are the perspective views of the assembly process of the temperature sensor as shown in FIG.1. The assembly process begins with terminal subassembly (124) (FIG. 5A). The terminals (112) are held together by the terminal holder (114) and the terminal holder (114) also acts as a partition to keep the terminals (112) and leads of the thermistor (116) separate from each other to prevent short circuit issues. After this step, the temperature sensor with terminal subassembly (126) is formed (FIG. 5B). The leads of the NTC thermistor (116) are welded to the terminals (112) and the temperature sensor bulb (118) along with the leads of the NTC thermistor (116) are joined to the terminals (112).

According to FIG. 5C, the plastic tube (120) is then inserted on the temperature sensor module (102) to protect the leads (116) from external pressure and damage. The temperature sensor bulb (118) is exposed to detect the temperature. This is the plastic tube subassembly (128) After this step, the outer brass body subassembly (130) is assembled as shown in FIG. 5D. The outer brass body (104) having the thread portion (122) is insert moulded to cover the temperature sensor module (102) with the tube (120). The terminals (112) and the terminal holder (114) are not covered by the brass outer body (104).
Finally, according to FIG. 5E, the brass body subassembly (130) is insert moulded with plastic material to cover the terminals (112). The plastic material covers the terminal holder (114) uniformly with molded plastic and is merged with the Brass body (104) to create the hexagonal part (106) and coupler part (108) that together form the plastic body (110). The brass body (104) has anti-rotation slot to achieve the tightening specification. In the insert moulding process, the hexagonal part (106) is incorporated in the plastic body (110). The hexagonal part (106) incorporated with the plastic body has the required specifications of tightening torque similar to the conventional temperature sensor. Some part of the plastic tube (120) portion is merged with the plastic body (110) during moulding.

According to the embodiment of the present invention, the temperature sensor has the following advantages:
? The cost of brass material is reduced as brass is not needed in the hexagonal part of the temperature sensor while maintaining the performance of the sensor to the optimum level.
? Terminal holder also acts as a partition to keep the terminals separate and no additional partition is required.
? Overall weight of the assembly reduces because of less brass material used in the temperature sensor.

While considerable emphasis has been placed herein on the components and component parts of the preferred embodiments, it will be appreciated that many embodiments can be made and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. These and other changes in the preferred embodiment as well as other embodiments of the disclosure will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.