A sealing structure of a magnet in an impeller and a flowmeter

Abstract

The utility model discloses a sealing structure of impeller inner magnet and flowmeter, including impeller casing, magnet, cover, be equipped with the accommodation cavity with the opening in the impeller casing, the magnet is located in the accommodation cavity, is equipped with the clamping groove on the impeller casing, the cover has the reverse buckling rib cooperation with clamping groove, the cover is attached on the impeller casing through injection molding and then seals the magnet in the accommodation cavity, the utility model discloses the injection molding mode compares the coating or welding mode of prior art, and the sealing reliability improves significantly, simplifies the production process, reduces the packaging cost, and through the cooperation structure of reverse buckling rib and clamping groove, forms the additional mechanical interlock after injection molding, avoids the hidden danger that the cover is easy to fall off from the impeller casing from structure, makes the cover and the combination of impeller casing better.

Description

Technical Field

[0001] This utility model relates to the field of impeller technology, and more specifically to a sealing structure for an internal magnet of an impeller and its flow meter. Background Technology

[0002] The impeller of the flow meter needs to be equipped with a magnet for sensing. However, the magnet will rust when it is in water for a long time, which will affect its magnetism and cause the flow meter to fail. At the same time, the rust will pollute the water quality. Especially in some products with high water quality requirements, the flow meter cannot be widely used in these products because the magnet rusts.

[0003] Therefore, some existing technologies have emerged to solve the above problems. For example, the magnet is coated to meet waterproof requirements before being mounted onto the impeller, or the magnet is first mounted onto the impeller and then sealed by welding. However, the waterproof coating may peel off, and once it does, the aforementioned problems will still occur. Welding to seal the magnet can also lead to water leakage if the weld is not strong, and it is also inefficient and costly. Therefore, to better seal the magnet, a secondary injection molding process is also used to install it into the impeller.

[0004] However, in the prior art, due to poor insert structure design, inserts that are injection molded twice are prone to separation between the first injection molded product (such as impeller housing) and the second injection molded product (such as cap) after long-term use or in environments with alternating hot and cold temperatures. This can lead to the magnet being exposed to water or other usage environments, resulting in seal failure, which in turn causes the magnet to rust and affects the normal use of the product. Utility Model Content

[0005] The purpose of this invention is to provide a snap-fit ​​groove on the impeller housing and a snap-fit ​​rib on the cover that engages with the snap-fit ​​groove, thereby more effectively sealing the magnet in the impeller, greatly improving the sealing performance, making it less prone to falling off, and providing strong stability.

[0006] To achieve the above objectives, this utility model provides the following technical solution: a sealing structure for an impeller magnet, comprising an impeller housing, a magnet, and a cover, wherein the impeller housing has an open receiving cavity, the magnet is located in the receiving cavity, the impeller housing has a snap-fit ​​groove, and the cover has a snap-fit ​​rib that cooperates with the snap-fit ​​groove. The cover is injection molded onto the impeller housing to seal the magnet in the receiving cavity.

[0007] The present invention is further configured such that: a sealed cavity communicating with the opening is formed inside the impeller housing; the accommodating cavity is integrally formed inside the sealed cavity; there is a space gap between the outer wall of the accommodating cavity and the inner wall of the sealed cavity; the snap-fit ​​groove is provided on the bottom wall of the space gap; and the cover is sealed to the sealed cavity to seal the magnet inside the accommodating cavity.

[0008] The present invention is further configured such that: one end of the sealed cavity has an opening, the receiving cavity is connected to the opening, and the opening of the receiving cavity faces the same direction as the opening of the opening.

[0009] The present invention is further configured such that: the impeller housing is integrally injection molded, the cover is formed on the impeller housing by secondary injection molding, and the reverse buckling rib is formed at the snap-fit ​​groove during the secondary injection molding.

[0010] The present invention is further configured such that: the cover has an annular platform, and the side wall of the annular platform is provided with a plurality of columns extending along the bottom wall direction of the partition gap; the reverse buckle is integrally formed at the bottom of the column, and the reverse buckle is connected to the snap-fit ​​groove in a one-to-one sealing fit.

[0011] The present invention is further configured such that the sealing fit between the column and the space gap, as well as the sealing fit between the reverse buckle and the snap-fit ​​groove, completely seals and covers the magnet, thereby sealing the magnet inside the impeller housing.

[0012] The present invention is further configured such that: a guide hole is provided in the center of the impeller housing, and a number of blades are arranged at intervals around the outer periphery of the impeller housing around the guide hole, and the magnet is located between the guide hole and the blades.

[0013] The present invention is further configured such that: at least two magnets are provided, and the magnets are arranged in a centrally symmetrical manner on the outer periphery of the guide hole.

[0014] The present invention is further configured such that both the impeller housing and the cover are made of plastic.

[0015] In addition, this utility model also proposes a flow meter, including the above-mentioned sealing structure, and also including an upper cover, a lower cover and a detection plate, with an impeller located between the upper cover and the lower cover. The lower cover is provided with an inlet and an outlet, or the inlet and outlet are respectively provided on the upper cover and the lower cover.

[0016] Compared with the prior art, the present invention has at least the following advantages:

[0017] 1. The cap adopts an injection molding assembly method to seal the opening. Compared with the existing coating or welding methods, the sealing reliability is significantly improved, the production process is simplified, the packaging cost is reduced, and the risk of water leakage caused by weak welding is avoided. Through the cooperation structure of the reverse buckle and the snap-fit ​​groove, an additional mechanical interlock is formed after injection molding, which structurally avoids the risk of the cap falling off the impeller housing, and makes the fit between the cap and the impeller housing better.

[0018] 2. The magnet is precisely positioned by the accommodating cavity, which prevents the magnet from shifting during the secondary injection molding process. At the same time, it prevents the magnet from shifting position when the impeller rotates (due to centrifugal force and water flow impact), ensuring that the magnet is always in the preset position for sensing and guaranteeing the metering accuracy of the flow meter. Attached Figure Description

[0019] Figure 1 This is an overall schematic diagram of this embodiment;

[0020] Figure 2 This is a cross-sectional view of this embodiment;

[0021] Figure 3 This is a frontal view of the impeller casing;

[0022] Figure 4 This is a view of the back of the impeller casing;

[0023] Figure 5 This is an exploded view of this embodiment.

[0024] Explanation of reference numerals in the attached figures:

[0025] 1. Impeller housing; 2. Magnet; 3. Cover; 4. Sealing cavity; 5. Snap-fit ​​groove; 501. First groove; 502. Second groove; 503. Third groove; 504. Fourth groove; 6. Reverse rib; 601. First rib; 602. Second rib; 603. Third rib; 604. Fourth rib; 7. Receiving cavity; 8. Injection channel; 9. Guide hole; 10. Blade. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can typically be arranged and designed in various different configurations.

[0027] like Figure 1 and Figure 2As shown, a sealing structure for a magnet inside an impeller includes an impeller housing 1, a magnet 2, and a cover 3. The impeller housing 1 has an open receiving cavity 7, and the magnet 2 is located within the receiving cavity 7. The impeller housing 1 has a snap-fit ​​groove 5, and the cover 3 has a snap-fit ​​rib 6 that mates with the snap-fit ​​groove 5. The cover 3 is injection molded onto the impeller housing 1, thereby sealing the magnet 2 within the receiving cavity 7 of the impeller housing 1 and providing a sealed protective space for the magnet 2. The snap-fit ​​rib 6 and the snap-fit ​​groove 5 form an additional mechanical interlock, solving the defect in the prior art where products injected for the first time and products injected for the second time are easily separated.

[0028] like Figures 3 to 5 As shown, a sealed cavity 4 communicating with an opening is formed inside the impeller housing 1. A receiving cavity 7 is integrally formed within the sealed cavity 4. The magnet 2 is installed within the receiving cavity 7. The cover 3 is sealed to the sealed cavity 4, thereby sealing the magnet 2 within the receiving cavity 7. The receiving cavity 7 is used to position the magnet 2, preventing positional shifts during the injection molding process of the cover 3 and during impeller rotation, ensuring that the magnet 2 is always in the preset position for sensing, and guaranteeing the flow meter's measurement accuracy.

[0029] A space gap exists between the outer wall of the receiving cavity 7 and the inner wall of the sealing cavity 4. A snap-fit ​​groove 5 is located on the bottom wall of the space gap. The cover 3 is sealed to the sealing cavity 4, thereby sealing the magnet 2 inside the receiving cavity 7. One end of the sealing cavity 4 has an opening, and the receiving cavity 7 communicates with the opening. The opening of the receiving cavity 7 faces the same direction as the opening of the opening, and is located on the front side of the impeller housing 1. The snap-fit ​​groove 5 is located on the back side of the impeller housing 1.

[0030] The cover 3 has an annular platform. Several pillars extending along the bottom wall of the partition space are spaced apart on the sidewalls of the annular platform. Reverse ribs 6 are integrally formed at the bottom of the pillars, and the reverse ribs 6 correspond one-to-one with the locking grooves 5 in a sealed fit. The impeller housing 1 has an injection channel 8 communicating with the locking grooves 5. During injection molding, the pillars and reverse ribs 6 are formed through the injection channel 8. The sealed fit between the pillars and the partition space, and the sealed fit between the reverse ribs 6 and the locking grooves 5, completely seals the magnet 2 within the impeller housing 1, thus sealing the magnet 2 inside the impeller housing 1. The size of the injection channel 8 is smaller than the size of the locking groove 5, thereby limiting the upper and lower positions of the cover 3 after the reverse ribs 6 are formed, achieving mechanical interlocking.

[0031] In this embodiment, the card slot 5 is provided with multiple slots, such as... Figure 4 The diagram shows a first groove 501, a second groove 502, a third groove 503, and a fourth groove 504. The side walls of the cover 3 are also provided with first ribs 601, second ribs 602, third ribs 603, and fourth ribs 604, which correspond to the multiple snap-fit ​​grooves 5 respectively. Through multi-point snap-fit ​​cooperation, the connection strength is further improved.

[0032] The impeller housing 1 is integrally injection molded, and the receiving cavity 7 is also formed simultaneously during the first injection molding of the impeller housing 1. After the impeller housing 1 is formed, the magnet is installed in the receiving cavity 7. The cover 3 is then formed onto the impeller housing 1 through a second injection molding process. The snap-fit ​​rib 6 is formed at the snap-fit ​​groove 5 during the second injection molding process. In this embodiment, both the impeller housing 1 and the cover 3 are made of plastic, ensuring good integration with the housing during the second injection molding process to form a solid overall structure.

[0033] The impeller housing 1 has a guide hole 9 in the center, and a number of blades 10 are arranged at intervals around the outer periphery of the impeller housing 1 around the guide hole 9. The magnet 2 is located between the guide hole 9 and the blades 10. At least two magnets 2 are provided, and the magnets 2 are arranged in a centrally symmetrical manner around the outer periphery of the guide hole 9 to enhance the magnetic field signal strength and make the magnetic field generated by the magnets 2 more uniform. In this embodiment, two sealed cavities 4 are formed on the impeller housing 1, each sealed cavity has an opening, and a receiving cavity 7 is formed in each of the two openings. The two magnets 2 are respectively installed in the two receiving cavities 7.

[0034] In addition, this embodiment also proposes a flow meter, including the above-mentioned sealing structure of the impeller internal magnet, and also includes an upper cover, a lower cover and a detection plate. The impeller is located between the upper cover and the lower cover. The lower cover is provided with an inlet and an outlet. Alternatively, the inlet and outlet are respectively provided on the upper cover and the lower cover.

[0035] The assembly process in this embodiment is as follows:

[0036] First, the impeller housing 1 is formed by a single injection molding process. Then, the magnet 2 is installed into the receiving cavity 7. Next, the cover 3 is formed onto the impeller housing 1 by a second injection molding process. The cover 3 seals the sealing cavity 4, thereby sealing the magnet 2. Structurally, the cover 3 is formed onto the impeller housing 1 by a second injection molding process, with no seam between the two, fundamentally eliminating the possibility of water leakage. The mechanical interlocking provided by the reverse-locking ribs 6 ensures the reliability of the connection under long-term use, and it is not easy to separate even in alternating hot and cold environments.

[0037] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the design concept of the present utility model should be included within the protection scope of the present utility model.

[0038] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

Claims

1. A sealing structure for an impeller internal magnet, comprising an impeller housing, a magnet, and a cover, characterized in that: The impeller housing has an open receiving cavity, the magnet is located in the receiving cavity, the impeller housing has a snap-fit ​​groove, and the cover has a snap-fit ​​rib that cooperates with the snap-fit ​​groove. The cover is injection molded onto the impeller housing to seal the magnet in the receiving cavity.

2. The sealing structure for an internal magnet of an impeller according to claim 1, characterized in that: A sealed cavity communicating with the opening is formed inside the impeller housing. The receiving cavity is integrally formed inside the sealed cavity. There is a space gap between the outer wall of the receiving cavity and the inner wall of the sealed cavity. The snap-fit ​​groove is provided on the bottom wall of the space gap. The cover is sealed to the sealed cavity to seal the magnet inside the receiving cavity.

3. The sealing structure for an internal magnet of an impeller according to claim 2, characterized in that: The sealed cavity has an opening at one end, and the receiving cavity is connected to the opening. The opening of the receiving cavity faces the same direction as the opening of the opening.

4. The sealing structure for an internal magnet of an impeller according to claim 1, characterized in that: The impeller housing is integrally injection molded, and the cover is formed on the impeller housing by secondary injection molding. The reverse buckle rib is formed at the snap-fit ​​groove during the secondary injection molding.

5. A sealing structure for an internal magnet of an impeller according to claim 2 or 3, characterized in that: The cover has an annular platform, and the sidewall of the annular platform is provided with a plurality of columns extending along the bottom wall direction of the space gap. The reverse buckle is integrally formed at the bottom of the column, and the reverse buckle is connected to the snap-fit ​​groove in a one-to-one sealing fit.

6. The sealing structure for an internal magnet of an impeller according to claim 5, characterized in that: The sealing fit between the column and the space gap, as well as the sealing fit between the reverse rib and the snap-fit ​​groove, ensures that the cover completely seals and covers the magnet, thereby sealing the magnet inside the impeller housing.

7. The sealing structure for an internal magnet of an impeller according to claim 1, characterized in that: The impeller housing has a guide hole in the center, and several blades are arranged at intervals around the outer periphery of the impeller housing around the guide hole. The magnet is located between the guide hole and the blades.

8. The sealing structure for an internal magnet of an impeller according to claim 7, characterized in that: At least two magnets are provided, and the magnets are arranged in a centrally symmetrical manner around the outer periphery of the guide hole.

9. The sealing structure for an internal magnet of an impeller according to claim 1, characterized in that: Both the impeller housing and the cover are made of plastic.

10. A flow meter, characterized in that: The sealing structure includes any one of claims 1-9, and further includes an upper cover, a lower cover, and a detection plate. The impeller is located between the upper cover and the lower cover. The lower cover is provided with an inlet and an outlet, or the inlet and outlet are respectively provided on the upper cover and the lower cover.

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