Water temperature sensor with integrated injection molding shell

Abstract

The utility model discloses a water temperature sensor with an integrated injection molding shell. The water temperature sensor comprises a thermistor, a terminal and a shell, wherein the thermistor comprises an extraction electrode, the terminal is electrically connected with the extraction electrode, the shell is of an integrated injection molding structure and wraps the thermistor and the terminal, but the end, away from the thermistor, of the terminal is exposed. The shell is made of an insulating heat-conducting material and completely covers the thermistor, so that the problem of short circuit possibly occurring when the metal shell is in contact with the thermistor is avoided. In addition, the shell is integrally formed, dispensing heat conduction can be omitted, and therefore the installation angle of the thermistor does not need to be limited in the manufacturing process, the process can be effectively simplified, the operation difficulty can be effectively lowered, and the manufacturing efficiency can be effectively improved.

Description

Technical Field

[0001] The utility model relates to the technical field of temperature sensors, in particular to a water temperature sensor with an integral injection-molded shell. Background Art

[0002] The water temperature sensor is typically installed at the engine's water outlet, primarily used to monitor the temperature. Most water temperature sensors are thermistors with negative temperature systems. As the water temperature rises, the sensor's resistance decreases. Based on this change, the electronic control unit measures the engine's cooling water temperature and uses it as a correction factor for fuel injection and ignition timing.

[0003] Existing water temperature sensors such as Figure 1a and Figure 1b As shown, it includes a metal shell 001, a thermistor 002 and a connector 003, wherein the connector is provided at one end of the metal shell and includes a terminal 031. The metal shell has an inner cavity with an open tail end, and the thermistor is encapsulated in the inner cavity by an insulating heat-conductive material. The thermistor has an extraction electrode, which is electrically connected to a temperature sensing signal lead. The temperature sensing signal lead extends out of the inner cavity and is connected to the terminal of the connector. The metal shell is connected, for example, by a threaded connection ( Figure 1a ) or snap( Figure 1b The thermistor of this type of water temperature sensor is coated in an insulating thermally conductive material, which is generally an epoxy potting compound.

[0004] In order to prevent the thermal conductive adhesive from remaining on the head of the thermistor, the installation angle requirements are relatively strict. On the other hand, after the water temperature sensor is used in alternating heat for a long time, the epoxy potting adhesive is easily peeled off from the inner cavity of the metal shell, affecting the temperature sensing performance. Utility Model Content

[0005] In order to solve some or all of the problems in the prior art, the present invention provides a water temperature sensor with an integral injection-molded housing, comprising:

[0006] a thermistor including an extraction electrode;

[0007] a terminal electrically connected to the lead-out electrode; and

[0008] The housing is an integrally formed structure, and the housing covers the thermistor and the terminal, but exposes one end of the terminal away from the thermistor.

[0009] Furthermore, there are two lead-out electrodes.

[0010] Furthermore, there are more than two lead-out electrodes.

[0011] Furthermore, the first end of the shell is in a stepped frustum shape, wherein the first end refers to the end where the thermistor is located.

[0012] Furthermore, the diameter of the shell covering the thermistor body is smaller than the diameter of other parts of the shell.

[0013] Furthermore, the middle portion of the shell includes a protrusion.

[0014] Furthermore, a slot is provided on the protrusion.

[0015] Furthermore, the second end of the housing relative to the first end includes a cavity with an open upper end, and the second end of the terminal is located in the cavity.

[0016] Furthermore, a card interface is provided on the outer surface of the second end of the shell.

[0017] Furthermore, a sealing structure is provided on the outer surface of the first end of the shell.

[0018] Based on the water temperature sensor as described above, the second aspect of the present invention provides a liquid temperature control circulation system, which includes the water temperature sensor as described above, and the water temperature sensor is used to monitor and feedback water temperature information in real time.

[0019] This utility model provides a water temperature sensor with an integrally injection-molded housing. The housing is formed using a one-piece injection molding process, completely enclosing the thermistor, thereby preventing potential short circuits that may occur when the metal housing and the thermistor come into contact. The one-piece injection-molded housing also eliminates the need for glue dispensing for heat conduction, eliminating the need to restrict the thermistor's mounting angle during manufacturing. This effectively simplifies the process, reduces operational complexity, and improves manufacturing efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] To further illustrate the above and other advantages and features of various embodiments of the present invention, a more detailed description of various embodiments of the present invention will be presented with reference to the accompanying drawings. It will be understood that these drawings depict only typical embodiments of the present invention and are not to be considered as limiting the scope thereof. In the drawings, for clarity, identical or corresponding components will be represented by the same or similar reference numerals.

[0021] Figure 1a and 1b The schematic diagrams of the structures of water temperature sensors in the prior art are shown respectively;

[0022] Figure 2 A schematic flow chart showing a method for manufacturing a water temperature sensor according to an embodiment of the present invention;

[0023] Figure 3A schematic structural diagram showing a water temperature sensor according to an embodiment of the present invention; and

[0024] Figure 4 A schematic diagram showing a water temperature sensor installed on a water pipe according to an embodiment of the present invention. DETAILED DESCRIPTION

[0025] In the following description, the present invention is described with reference to various embodiments. However, those skilled in the art will recognize that the various embodiments can be implemented without one or more specific details or with other alternative and / or additional methods, materials or components. In other cases, well-known structures, materials or operations are not shown or described in detail to avoid obscuring the practical points of the present invention. Similarly, for the purpose of explanation, specific quantities, materials and configurations are described in order to provide a comprehensive understanding of the embodiments of the present invention. However, the present invention is not limited to these specific details. In addition, it should be understood that the various embodiments shown in the drawings are illustrative representations and are not necessarily drawn to the correct scale.

[0026] In this specification, reference to "one embodiment" or "the embodiment" means that a particular feature, structure, or characteristic described in conjunction with the embodiment is included in at least one embodiment of the present invention. The phrase "in one embodiment" appearing in various places in this specification does not necessarily refer to the same embodiment.

[0027] It should be noted that the embodiments of the present invention describe the process steps in a specific order. However, this is only for the purpose of illustrating the specific embodiment and does not limit the order of the steps. On the contrary, in different embodiments of the present invention, the order of the steps can be adjusted according to the process.

[0028] A water temperature sensor typically consists of a front connector and a rear metal housing. A thermistor is housed within the metal housing and electrically connected to the connector. To prevent short circuits caused by contact between the thermistor and the metal housing, during the manufacturing process, a thermally conductive insulating material, such as a heat-conducting material, is placed inside the metal housing before the thermistor is inserted into the insulating material at a predetermined angle. This method places high demands on the installation angle. On the one hand, it is necessary to prevent the thermistor from penetrating the insulating material and coming into contact with the metal housing; on the other hand, it is also necessary to prevent the insulating material from flowing back, ensuring that the insulating material remains at the top of the thermistor, thereby preventing excessive response time. To address these issues and simplify the manufacturing process and improve manufacturing efficiency while ensuring performance, the present utility model provides a method for manufacturing a water temperature sensor that eliminates the need for connecting the connector to the conventional metal housing. Specifically, the method involves welding the thermistor to the terminals and then integrally injection molding the thermistor through a mold. The plastic particles completely encapsulate the thermistor, leaving no gaps, thereby meeting insulation requirements while also ensuring waterproof and dustproof performance. At the same time, it adopts one-piece injection molding and can be installed at any angle, effectively reducing the difficulty of installation.

[0029] The technical solution of the present invention is further described below in conjunction with the accompanying drawings of the embodiments.

[0030] Figure 2 The following is a flow chart showing a method for manufacturing a water temperature sensor according to an embodiment of the present invention. Figure 2 As shown, a method for manufacturing a water temperature sensor includes:

[0031] First, in step 201, the thermistor and terminals are connected. The thermistor is electrically connected to the terminals. One end of the water temperature sensor includes a connector, which is used to transmit electricity and / or signals between the water temperature sensor and an external circuit. The connector typically consists of three parts: a contact, an insulator, and a housing. The contact, also known as the terminal, is typically made of a conductive metal material and is the core component of the connector that completes the electrical connection function. The insulator isolates and secures the contact, ensuring stable current transmission, and the housing provides physical protection and fixation. Generally, the connector is manufactured by placing the terminal in the cavity of an injection mold, then injecting plastic into the cavity, cooling the mold, and removing it after molding to form the insulator and / or housing. However, since the entire housing of the water temperature sensor in the present invention is molded in an integrated process, it is necessary to first electrically connect the internal structures of the water temperature sensor, that is, the thermistor to the connector. Therefore, in one embodiment of the present invention, the lead electrodes of the thermistor are first welded to the terminals in a one-to-one correspondence. The terminals are then combined with the housing to form the connector. In one embodiment of the present invention, the thermistor may have two or more lead electrodes, and accordingly, the terminals may also have two or more terminals. In one embodiment of the present invention, the terminals are made by stamping metal sheets; and

[0032] Next, in step 202, a shell is formed. As previously mentioned, in an embodiment of the present invention, the shell is made using an integrated molding process, that is, an insulating thermally conductive material is used to cover the thermistor and at least part of the terminals to form the shell. As previously mentioned, one end of the shell needs to serve as a connector to achieve electrical connection with an external circuit, so the insulating thermally conductive material does not completely cover the terminals, but exposes at least a portion of the terminals. Specifically, in one embodiment of the present invention, the insulating thermally conductive material can cover one end of each terminal close to the thermistor, thereby forming an insulator between the terminals for isolating and fixing the terminals. In another embodiment of the present invention, the insulating thermally conductive material can also form a cavity with an open upper end at the first end, so that the terminal is located in the cavity, thereby serving as a shell of a connector to protect the terminal, wherein the first end is to the end away from the thermistor.

[0033] In one embodiment of the present invention, the shell is made by an integrated injection molding process, which can be achieved by an injection molding machine based on a mold of a specified shape. Based on this, the material of the shell is a thermoplastic resin, for example, polyhexamethylene adipamide (PA66) can be used. In one embodiment of the present invention, the shell is manufactured by an integrated injection molding process. First, the terminals and thermistor that have been electrically connected need to be placed in the mold. In this process, in order to avoid the terminals and thermistor being distorted under the subsequent injection molding pressure, a pin or other positioning member can be set in the mold to fix the terminals and thermistor. Next, the insulating thermally conductive material that has been heated and melted is injected into the mold with a certain pressure so that the liquid insulating thermally conductive material completely covers the thermistor and the terminal is close to one end of the thermistor. Finally, the insulating thermally conductive material is waited for to cool and solidify, and it is removed from the mold to complete the manufacture of the water temperature sensor. In some embodiments of the present invention, further processes such as deburring and polishing can be performed.

[0034] In order to achieve better performance, the shell shape of the water temperature sensor needs to be limited. For example, in order to improve sensitivity, the thickness of the insulating thermal conductive material covering the thermistor body should not be too large, and the thickness of the insulating thermal conductive material of the remaining parts can be increased accordingly to provide better protection. For another example, the water temperature sensor is usually installed on a water pipe. In order to adapt to the pipe interface, the shell of the water temperature sensor also needs to be provided with a certain fixed structure, such as a threaded structure, a slot, etc. For another example, in order to improve the waterproof and dustproof level, the shell should also be provided with a corresponding sealing structure. The characteristics of the shell can be defined by the shape of the mold. In one embodiment of the present invention, a mold for manufacturing a water temperature sensor includes a first part, a middle part and a second part, wherein the first part refers to the part where the thermistor is placed, the second part refers to the part where the terminal is placed, and the middle part is located between the first and second parts. In one embodiment of the present invention, the first part is a stepped frustum. Specifically, the diameter of the top end, that is, the part where the thermistor body is placed, is smaller than that of the remaining parts. In one embodiment of the present invention, in order to adapt to the structure of the water pipe, the first end may also be a three-step stepped cone, and the diameter of the mold increases successively from the end. In order to facilitate fixation, in one embodiment of the present invention, a first protrusion is provided at the middle part and / or the first part of the mold, so that a card slot can be formed in the middle part of the shell made based on the mold to facilitate the installation of snaps, etc. There is no restriction on the diameter of the second part of the mold. For example, it can be smaller than the diameter of the third stage of the three-step stepped cone, and / or equal to the diameter of the second stage of the three-step stepped cone, etc., but its end is in the form of a connector. Specifically, it includes, for example, a component covering the terminal, so that there is a certain gap between the terminals after the final molding, and / or it has a connector of a specified shape, etc.

[0035] In one embodiment of the present invention, in order to further improve the waterproof and dustproof performance, a sealing structure may be provided on the outside of the housing, for example, a sealing ring may be provided on the outside of the first end of the housing.

[0036] Based on the manufacturing method described above, Figure 3 The following is a schematic diagram showing the structure of a water temperature sensor according to an embodiment of the present invention. Figure 3 As shown, a water temperature sensor includes a thermistor 301, a terminal 302 and a shell 303, wherein the lead electrode 311 of the thermistor 301 is electrically connected to the first end of the terminal 302, and the shell 303 is made by an integrated molding process, completely covering the thermistor while exposing the second end of the terminal to form a connector.

[0037] like Figure 3As shown, the first end of the shell, that is, the end where the thermistor is located, is in a stepped truncated cone shape. Specifically, the diameter of the shell covering the thermistor body is smaller than the diameter of the other parts of the shell. Figure 3 As shown, the middle part of the housing includes a protrusion 331 to facilitate snapping onto the water pipe interface. At the same time, a card slot 332 is provided on the protrusion. When the water temperature sensor is installed on the water pipe interface, a buckle 401 can be provided at the card slot to better fix the water temperature sensor. Figure 4 As shown. Figure 3 As shown, the second end of the housing is in the form of a socket. Specifically, the second end includes a cavity 333 with an upper end opening. The second end of the terminal 302 is located in the cavity and can be electrically connected to an external circuit by plugging or welding. Figure 3 As shown, in one embodiment of the present invention, the outer surface of the second end of the housing is provided with a card interface 334. In one embodiment of the present invention, the outer surface of the first end of the housing is further provided with a sealing structure, such as a sealing ring 402.

[0038] The water temperature sensor can be applied to a liquid temperature control circulation system, for example, to monitor and feedback water temperature information in real time.

[0039] This utility model provides a method for manufacturing a water temperature sensor. The housing of the water temperature sensor is formed through an integral injection molding process, completely enclosing the thermistor. This prevents short circuits that may occur when the metal housing and the thermistor come into contact. The integrally molded housing also eliminates the need for glue dispensing for heat conduction, eliminating the need to restrict the thermistor's mounting angle during manufacturing. This effectively simplifies the process, reduces operational complexity, and improves manufacturing efficiency.

[0040] Although various embodiments of the present invention have been described above, it should be understood that they are presented by way of example only and not limitation. It will be apparent to those skilled in the relevant art that various combinations, modifications, and variations may be made thereto without departing from the spirit and scope of the present invention. Therefore, the breadth and scope of the present invention as disclosed herein should not be limited by the exemplary embodiments disclosed above, but should be defined solely in accordance with the appended claims and their equivalents.

Claims

1. A water temperature sensor with an integral injection molded housing, characterized in that: include: a thermistor including an extraction electrode; a terminal electrically connected to the lead-out electrode; as well as The housing is an integral injection-molded structure, and the housing covers the thermistor and the terminal, but exposes one end of the terminal away from the thermistor.

2. The water temperature sensor according to claim 1, wherein: There are two or more extraction electrodes.

3. The water temperature sensor according to claim 1, wherein: The first end of the shell is in a stepped frustum shape, wherein the first end refers to the end where the thermistor is located.

4. The water temperature sensor according to claim 1, wherein: The diameter of the shell covering the thermistor body is smaller than the diameter of the shell of other parts.

5. The water temperature sensor according to claim 1, wherein: The middle portion of the housing includes a protrusion.

6. The water temperature sensor according to claim 5, characterized in that: The protrusion is provided with a card slot.

7. The water temperature sensor according to claim 1, wherein: The second end of the housing includes a cavity with an open upper end, and the second end of the terminal is located in the cavity.

8. The water temperature sensor according to claim 1, wherein: A card interface is provided on the outer surface of the second end of the shell.

9. The water temperature sensor according to claim 1, wherein: A sealing structure is provided on the outer surface of the first end of the shell.

10. A liquid temperature control circulation system, characterized in that: It comprises the water temperature sensor according to any one of claims 1 to 9, wherein the water temperature sensor is configured to monitor and feedback water temperature information in real time.

Images