Sensor

Abstract

The utility model relates to a sensor. The sensor comprises a shell, a PCB and a cable assembly. The shell defines a containing cavity, and the containing cavity is provided with an opening; the PCB is accommodated in the accommodating cavity; the cable assembly comprises at least one cable main body, and the end part of the cable main body extends into the accommodating cavity through the opening so as to be electrically connected with the PCB; wherein in the accommodating cavity, a sealing element formed by glue is only arranged at the position of a connecting part of the end part of the cable main body and the PCB, and the sealing element is used for wrapping the connecting part and the end part of the cable main body and blocking the opening. According to the sensor provided by the utility model, the usage amount of glue is reduced, the contact area between the sealing element and the internal structure of the sensor, such as a PCB, is reduced, and elements on the PCB are convenient to maintain during use.

Description

Technical Field

[0001] The utility model relates to the technical field of sensors, in particular to a position sensor used for detecting the position of a motor shaft. Background Art

[0002] If a motor, such as an ordinary DC motor (with brushes for commutation), needs to collect speed for speed control, it may be necessary to install a sensor, such as a position sensor, on the motor shaft. Some motors also require a position sensor to accurately obtain the position of the motor's rotor for high-precision control. For example, a BLDC (brushless DC motor) uses a sensor to obtain the position of the rotor to achieve commutation. For another example, a PMSM (permanent magnet synchronous motor) uses a photoelectric angular position sensor to obtain the angle of the rotor.

[0003] The working environment of the sensor in the motor is relatively harsh. For example, there is a large amount of water vapor and oil gas in the environment. In order to prevent water and oil from entering the interior of the sensor and corroding the precision components such as the PCB board therein, the sensors in the prior art usually fill the inner cavity of the position sensor with colloid to achieve the purpose of sealing the position sensor and isolating water vapor. However, such operation often results in a huge consumption of sealant. In addition, due to its fluidity, the sealant is difficult to fill the gap of the entire sensor cavity, thereby generating bubbles during the high-temperature curing process of the colloid, resulting in failure to meet the sealing requirements. In addition, when the colloid is completely filled in the inner cavity, it is not convenient to repair the components inside the sensor. Utility Model Content

[0004] The purpose of the present invention is to solve at least one of the above problems and / or other problems existing in the prior art.

[0005] To achieve the above object, according to one aspect of the utility model, a sensor is provided, the sensor comprising a housing, a PCB board and a cable assembly. The housing defines a housing cavity having an opening; the PCB board is accommodated in the housing cavity; the cable assembly comprises at least one cable body, the end of the cable body extends into the housing cavity through the opening to establish an electrical connection with the PCB board; wherein, in the housing cavity, a sealing member formed of glue is provided only at the position of the connection portion between the end of the cable body and the PCB board, so as to wrap the connection portion and the end of the cable body and seal the opening.

[0006] The sensor of the utility model is only provided with a sealant at the position of the end of the cable body extending into the accommodating cavity and the connection part of the PCB board, which means that the material (such as glue) used to form the sealant is only provided at a local part of the accommodating cavity of the housing (i.e., the part where the PCB board is connected to the cable body), and does not need to fill the entire accommodating cavity. Such a design not only provides protection for the connection part between the PCB board and the cable body and blocks the opening of the housing, completely prevents water vapor and oil gas from entering the accommodating cavity from between the sealant and the housing, and between the sealant and the end of the cable body, but also significantly reduces the amount of sealant material used, and reduces the contact area between the sealant and the internal structure of the sensor, such as the PCB board, which facilitates the maintenance of the components on the PCB board during use.

[0007] According to an embodiment of the utility model, the housing includes a bottom wall, a circumferential wall and a top plate, the opening is formed between the circumferential wall and the top plate, and the seal has an inclined surface facing away from the opening and extending toward the bottom wall, so that the seal has a generally trapezoidal cross section. This structure can ensure that the end of the cable body and the connection part of the PCB board are completely covered while minimizing the amount of sealant used, thereby reducing electromagnetic interference to the sensor during detection.

[0008] According to an embodiment of the present invention, the vertical distance between the end of the end portion of the cable body and the inclined surface of the sealing member is greater than 1 mm. This structure can further reduce electromagnetic interference during sensor detection.

[0009] According to an embodiment of the utility model, the housing further comprises two separated baffles extending in parallel with the two ends of the circumferential wall corresponding to the opening, the two baffles having an outer shape matching the cross section of the seal, thereby defining a glue injection cavity for receiving the seal between the two baffles. This structure can form a glue injection cavity at the opening, limit the injection of the sealant to a predetermined space, and further reduce the amount of colloid used as the material of the sealant.

[0010] According to an embodiment of the utility model, the top plate, the circumferential wall, the bottom wall and the two baffles of the housing are integrally formed into a whole. This structure can increase the sealing performance of the connection between the sensor and the housing parts.

[0011] According to one embodiment of the utility model, the cable assembly includes a cable rack and a plurality of cable bodies, wherein the cable rack is configured to be detachably mounted in the opening of the housing in a form-fitting manner and has rows of through holes for the ends of the plurality of cable bodies to pass through. The structure can provide strong support for the plurality of cable bodies through the cable rack, preventing the formation of a gap between the cable body and the seal during use due to the elasticity of the glue and the loss of sufficient support and deformation of the cable body, thereby preventing oil, gas and water vapor from entering the accommodating cavity through the gap.

[0012] According to an embodiment of the present invention, the cable rack includes a main body portion, and the main body portion is configured to be partially embedded in the opening.

[0013] According to an embodiment of the utility model, the top edge and the bottom edge of the main body are respectively provided with a plurality of protruding and spaced first teeth, and the end edges of the top plate and the bottom wall are respectively provided with a plurality of spaced second teeth, and the first teeth and the second teeth can be engaged in a clamping manner in an interference fit. This structure is conducive to directly clamping the cable rack on the top plate and the bottom wall, and is easy to disassemble.

[0014] According to an embodiment of the utility model, the bottom wall includes an annular wall portion and an extended wall portion radially extending from a predetermined sector of the annular wall portion, the circumferential wall includes an inner circumferential wall portion extending perpendicularly relative to the inner circumference of the annular wall portion and an outer circumferential wall portion extending perpendicularly relative to the outer circumference of the bottom wall, and the opening is formed at the extended wall portion. This structure can be advantageously applied to specific applications such as motor shafts.

[0015] According to an embodiment of the present invention, the housing further comprises a cover plate having a shape matching the bottom wall for closing the accommodating cavity. This structure is conducive to providing good protection for important components such as a PCB board in the accommodating cavity of the housing. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The features and advantages of the present invention will be clearly understood through the detailed description provided below with reference to the accompanying drawings. It should be understood that the following drawings are merely schematic and not necessarily drawn to scale, and thus cannot be regarded as limiting the present invention, wherein:

[0017] Figure 1 A perspective view of a sensor according to an exemplary embodiment of the present invention is shown.

[0018] Figure 2 Show Figure 1 Exploded view of the sensor shown.

[0019] Figure 3 Show Figure 1The sensor is shown in a top view with the cover and seal removed.

[0020] Figure 4 Show Figure 3 A cross-sectional view of the sensor along line AA is shown.

[0021] Figure 5 Show Figure 1 A top view of the sensor is shown.

[0022] Figure 6 Show Figure 5 A cross-sectional view of the sensor along line BB is shown.

[0023] Description of reference numerals:

[0024] 1. Shell; 11. Bottom wall; 111. Annular wall portion; 112. Extended wall portion; 12. Circumferential wall; 121. Inner circumferential wall portion; 122. Outer circumferential wall portion; 13. Top plate; 14. Opening; 15. Accommodating cavity; 16. Baffle plate; 17. Second tooth; 18. Cover plate; 181. Annular plate; 182. Extended plate; 2. PCB board; 21. Connecting portion; 3. Cable assembly; 31. Cable body; 32. Cable rack; 321. Through hole; 322. Main body; 323. First tooth; 4. Sealing member; 41. Inclined surface; 5. Glue injection cavity. DETAILED DESCRIPTION

[0025] Embodiments of the present invention are described below with reference to the accompanying drawings. In the following description, many specific details are set forth so that those skilled in the art can more fully understand and implement the present invention. However, it is obvious to those skilled in the art that the implementation of the present invention may not have some of these specific details. In addition, it should be understood that the present invention is not limited to the specific embodiments described. On the contrary, any combination of the features and elements described below may be considered to implement the present invention, regardless of whether they relate to different embodiments. Therefore, the following aspects, features, embodiments and advantages are for illustrative purposes only and should not be regarded as elements or limitations of the claims unless clearly stated in the claims.

[0026] In the following, terms such as "first", "second", etc. are used to describe the elements of the present application. These terms are only used to distinguish the various elements, and are not used to limit the nature, order or number of these elements. The terms "including" and "having" are used to express an open-ended inclusive meaning, and mean that there may be additional elements / components in addition to the listed elements / components.

[0027] The motor usually includes a motor shaft, a rotor connected to the motor shaft, and a stator arranged on the outer periphery of the rotor. A vector magnetic field is generated by passing three-phase alternating current through the stator, and the magnetic field drives the rotor to rotate an angle, so that a pair of magnetic field directions of the rotor are consistent with the magnetic field directions of the stator. When the vector magnetic field of the stator rotates an angle, the rotor also rotates an angle with the magnetic field. As mentioned in the background technology, the motor needs to obtain the speed, position, etc. of the rotor through a sensor mounted on the motor shaft. It can be understood that the novel sensor used in the present invention can also be used in other components mounted on the shaft and capable of moving relative to the shaft to obtain the motion trajectory, position, speed, etc. of the component or the shaft.

[0028] Figure 1 and Figure 2 A sensor according to an embodiment of the present invention is shown, in particular, a position sensor for installation on a motor shaft of a motor. Figure 1 and Figure 2 As shown, the sensor according to this embodiment may include a housing 1 , a PCB board 2 , a cable assembly 3 and a seal 4 .

[0029] According to an exemplary embodiment of the housing 1, Figure 2 As shown in FIG. 1 , the housing 1 may include a bottom wall 11, a circumferential wall 12 and a top plate 13. The circumferential wall 12 surrounds the outer periphery of the bottom wall 11 and extends perpendicularly to the bottom wall 11, thereby defining a top plate 13 on the top (with a circumferential wall 12). Figure 1-2 The circumferential wall 12 is configured to be disconnected at a portion of the outer circumference of the bottom wall 11, thereby forming an opening 14. At the opening 14, a top plate 13 can be provided on the edge of the circumferential wall 12 facing away from the bottom wall 11 to cover the opening 14 from above and thereby make the opening 14 only in the lateral direction ( Figure 1-2 The PCB board 2 is accommodated in the accommodation cavity 15, and its shape can be substantially the same as the shape of the accommodation cavity 15 and thus the shape of the bottom wall 11. Here, the bottom wall 11 can be a plate-like structure of any shape, and the circumferential wall 12 can include a peripheral wall portion 122 that matches the shape of the outer peripheral edge of the bottom wall 11.

[0030] In order to be able to sleeve the position sensor on a shaft (e.g., a motor shaft), in the embodiment shown in the figure, the bottom wall 11 can be composed of an annular plate, and can include an annular wall portion 111 as a main body and an extended wall portion 112 for constructing the opening 14. The annular wall portion 111 has a circular central through hole for the shaft to pass through, and the extended wall portion 112 is formed by extending a predetermined sector of the annular wall portion 111 radially outward. It can be understood that the extended wall portion 112 is a roughly rectangular plate-shaped portion formed by extending the outer periphery of the predetermined sector of the annular wall portion 111 radially outward.

[0031] In the illustrated embodiment, the circumferential wall 12 may include an inner circumferential wall portion 121 and an outer circumferential wall portion 122. The inner circumferential wall portion 121 surrounds the inner circumference of the annular wall portion 111 and extends perpendicularly to the annular wall portion 111, thereby forming the inner side wall of the accommodating cavity 15. The outer circumferential wall portion 122 surrounds part of the outer circumference of the bottom wall 11, especially around the outer circumference of the annular wall portion 111 and part of the outer circumference of the extended wall portion 112, and extends perpendicularly to the bottom wall 11, thereby forming the outer side wall of the accommodating cavity 15. In this way, the portion of the extended wall portion 112 of the bottom wall 11 that is not surrounded by the circumferential wall 12, and specifically not surrounded by the outer circumferential wall portion 122, can leave a space for forming the opening 14.

[0032] Advantageously, reference Figures 2 to 4 The housing 1 may further include two baffles 16 disposed at intervals. The two baffles 16 may be disposed at positions corresponding to the openings 14 of the bottom wall 11, wherein one baffle 16 is parallel to the circumferential wall 12 and in particular one end of the peripheral wall portion 122 thereof and is spaced a certain distance therefrom, and the other baffle 16 is parallel to the circumferential wall 12 and in particular the other end of the peripheral wall portion 122 thereof and is spaced a certain distance therefrom. The two baffles 16 may have the same shape. For example, Figure 4 and 6 As shown, the baffle 16 has a slope, which extends in a direction away from the opening 14 (i.e., in a direction toward the left in the figure) and is inclined toward the bottom wall 11. Thus, a relatively small glue injection cavity 5 is defined between the two baffles 16, the bottom wall 11, and the top plate 13. This is conducive to further limiting the amount of glue material used to form the sealing member 4, thereby advantageously reducing material costs and shortening manufacturing time.

[0033] Preferably, the bottom wall 11, the circumferential wall 12, the top plate 13 and the two baffles 16 are formed as a whole. For example, these parts can be injection molded into an integral housing 1 by injection molding.

[0034] Furthermore, the housing 1 may further include a cover plate 18. The cover plate 18 has an outer shape matching the bottom wall 11 to close the accommodating cavity 15. For example, when the sensor is used for a shaft structure and its housing 1 has the structure shown in the drawings, the cover plate 18 may include an annular plate 181 and an extension plate 182 extending from one side of the annular plate 181. The shape of the annular plate 181 corresponds to the shape of the annular wall portion 111, and the shape of the extension plate 182 corresponds to at least a part of the shape of the extension wall portion 112. The cover plate 18 may be mounted on the housing 1, especially connected to the circumferential wall 12 and the top plate 13, by laser welding or bolt connection.

[0035] According to an exemplary embodiment of the cable assembly 3, Figures 2 to 4As shown, the cable assembly 3 may include at least one cable body 31. The cable body 31 may be one or more. The end of each cable body 31 extends into the accommodating cavity 15 through the opening 14 to establish an electrical connection with the PCB board 2. When there are multiple cable bodies 31, in order to support each cable body 31 and prevent the cable body 31 from twisting, stretching, etc. caused by the disconnection problem, the cable assembly 3 of this embodiment may also include a cable rack 32. The cable rack 32 includes a main body 322 that can be partially embedded in the opening 14, and the main body 322 is provided with rows of through holes 321 for the ends of each cable body 31 to pass through. The cable rack 32 is configured to be detachably mounted in the opening 14 of the housing 1 in a shape-fitting manner.

[0036] Specifically, a portion of the main body 322 is embedded in the opening 14, and the other portion extends out of the opening 14 and has a plurality of first teeth 323 disposed at intervals on the top edge and the bottom edge thereof. Figure 4 As shown, the multiple first teeth 323 at the top are perpendicular to the extension direction of the main body 322 and face the top plate 13, and the multiple first teeth 323 at the bottom are perpendicular to the extension direction of the main body 322 and face the bottom wall 11. The end edges of the bottom wall 11 and the top plate 13 close to the part of the main body 322 extending out of the opening 14 are respectively provided with multiple spaced second teeth 17. The first teeth 323 and the second teeth 17 are engaged in a clamping manner in an interference fit, so that the cable rack 32 can be fixed on the housing 1.

[0037] According to the utility model, reference Figure 5 , the seal 4 is only arranged at the position where the end of the cable body 31 extending into the accommodating cavity 15 and the connecting portion 21 of the PCB board 2 are located, and it is only necessary to completely wrap the connecting portion 21 of the PCB board 2 and the end of the cable body 31. The seal 4 completely blocks the opening 14 and fills the gap between the seal 4 and the housing 1, which can prevent water vapor and oil gas from entering the accommodating cavity 15 from the gap. It can be understood that the seal 4 can be a rubber block formed by an elastic material through injection molding or the like, and it is installed at the opening 14 in an interference fit. In particular, the seal 4 can be a rubber block directly formed in the accommodating cavity 15 by glue injection at the opening 14, which can wrap or cover the connection between the cable body 31 and the PCB board 2 during the slow glue injection process.

[0038] In a further embodiment, the end of the cable body 31 is fixed at a position approximately in the middle height of the cable rack 32 when entering the accommodating cavity 15, and gradually tilts toward the PCB board 2 close to the bottom wall 11 after entering the accommodating cavity 15, so as to be fixed with the connecting portion 21 of the PCB board 2 to establish an electrical connection. In order to completely cover the end of the cable body 31 and the connecting portion 21 of the PCB board 2 during the glue injection process, the sealing member 4 has the following Figure 6The inclined surface 41 shown. The inclined surface 41 gradually inclines toward the bottom wall 11 as it gradually moves away from the opening 14. Thus, the seal 4 formed during the injection process can have a generally trapezoidal cross section. In order to meet the sealing requirements and further reduce the impact of electromagnetic interference on the detection process of the sensor, the vertical distance between the end of the end of the cable body 31 and the inclined surface 41 of the seal 4 is greater than 1 mm. In other words, the minimum thickness of the seal 4 covering the connection between the cable body 31 and the PCB board 2 is greater than 1 mm.

[0039] In order to avoid the formation of bubbles in the corners of the housing 1, a colloid with good fluidity can be used. In the process of directly injecting glue into the opening 14 of the housing 1, the housing 1 can be tiltedly clamped on, for example, a clamping device or placed on an inclined work surface so that the slope of the baffle 16 can be parallel to the horizontal plane. The slope of the baffle 16 is used as a reference plane for injection. When the top surface of the colloid is flush with the slope of the baffle 16, it means that the colloid has completely filled the injection cavity 5 and the injection is stopped.

[0040] In order to prevent water vapor and oil gas from entering the interior of the sensor in the prior art, the inner cavity is often filled with colloid to achieve the purpose of isolating water vapor and oil gas from corroding the internal precision components. However, this will result in a huge consumption of sealant. It is also difficult to fill the inner cavity of the sensor, especially in the corners closer to the shell, which will produce a large number of bubbles, thus failing to meet the sealing requirements. The sealant almost completely covers the outer surface of the internal precision components, which is also not conducive to later maintenance. Compared with the prior art, the sensor of the embodiment of the utility model is only provided with a sealant 4 formed by glue at the end of the cable body 31 extending into the accommodating cavity 15 and the position of the connecting portion 21 of the PCB board 2, and the sealant 4 is completely wrapped around the end of the connecting portion 21 and the cable body 31, and the opening 14 is blocked at the same time. Thus, the sealant 4 completely prevents water vapor and oil gas from entering the accommodating cavity 15 between the sealant 4 and the shell 1, and between the sealant 4 and the end of the cable body 31. The utility model reduces the amount of glue used and reduces the contact area between the seal 4 and the internal structure of the sensor, such as the PCB board 2, so that it is convenient to maintain the components on the PCB board during use.

[0041] For those skilled in the art, various modifications and variations may be made to the embodiments disclosed above without departing from the scope or spirit of the utility model. Other embodiments of the utility model will be apparent to those skilled in the art from the practice of the utility model disclosed in this specification. This specification and the examples disclosed therein should be considered to be illustrative only, and the true scope of the utility model is specified by the appended claims and their equivalents.

Claims

1. A sensor, characterized in that: The sensor includes: A housing (1), wherein the housing (1) defines a receiving chamber (15), wherein the receiving chamber (15) has an opening (14); A PCB board (2), the PCB board (2) being accommodated in the accommodation cavity (15); and A cable assembly (3), the cable assembly (3) comprising at least one cable body (31), an end of the cable body (31) extending into the accommodating cavity (15) via the opening (14) so ​​as to establish an electrical connection with the PCB board (2); Wherein, in the accommodating cavity (15), a sealing member (4) formed of glue is provided only at the position of the end of the cable body (31) and the connecting portion (21) of the PCB board (2), so as to wrap the connecting portion (21) and the end of the cable body (31) and to seal the opening (14).

2. The sensor according to claim 1, characterized in that The housing (1) comprises a bottom wall (11), a circumferential wall (12) and a top plate (13); the opening (14) is formed between the circumferential wall (12) and the top plate (13); the sealing member (4) has an inclined surface (41) facing away from the opening (14) and extending toward the bottom wall (11), so that the sealing member (4) has a generally trapezoidal cross section.

3. The sensor according to claim 2, characterized in that The vertical distance between the end of the end portion of the cable body (31) and the inclined surface (41) of the sealing member (4) is greater than 1 mm.

4. The sensor according to claim 2, characterized in that The housing (1) further comprises two spaced-apart baffles (16) extending in parallel with two ends of the circumferential wall (12) corresponding to the opening (14), the two baffles (16) having an outer shape matching the cross-section of the seal (4), thereby defining a glue injection cavity (5) for receiving the seal (4) between the two baffles (16).

5. The sensor according to claim 4, characterized in that The top plate (13), the circumferential wall (12), the bottom wall (11) and the two baffles (16) of the housing (1) are integrally formed into a whole.

6. The sensor according to claim 2, characterized in that The cable assembly (3) comprises a cable rack (32) and a plurality of cable bodies (31); the cable rack (32) is configured to be detachably mounted in an opening (14) of the housing (1) in a form-fitting manner, and has rows of through holes (321) for allowing the ends of the plurality of cable bodies (31) to pass through.

7. The sensor according to claim 6, characterized in that The cable rack (32) includes a main body (322) configured to be partially embedded in the opening (14).

8. The sensor according to claim 7, characterized in that The top edge and the bottom edge of the main body (322) are respectively provided with a plurality of protruding and spaced-apart first teeth (323), and the end edges of the top plate (13) and the bottom wall (11) are respectively provided with a plurality of spaced-apart second teeth (17), and the first teeth (323) and the second teeth (17) can be snap-engaged in an interference fit manner.

9. The sensor according to any one of claims 2 to 8, characterized in that The bottom wall (11) comprises an annular wall portion (111) and an extended wall portion (112) radially extending from a predetermined sector of the annular wall portion (111), the circumferential wall (12) comprises an inner circumferential wall portion (121) extending perpendicularly relative to an inner circumferential edge of the annular wall portion (111) and an outer circumferential wall portion (122) extending perpendicularly relative to an outer circumferential edge of the bottom wall (11), and the opening (14) is formed at the extended wall portion (112).

10. The sensor according to claim 9, characterized in that The housing (1) further comprises a cover plate (18) having an outer shape matching the bottom wall (11) and used for closing the accommodating cavity (15).

Images