Acceleration sensor

Abstract

An acceleration sensor comprises a device base and a cover plate which are arranged on the outermost layer, a sealing ring arranged between the device base and the cover plate, a circuit board enclosed in the device base and the cover plate, and a waterproof joint arranged at one end of the device base, and a cable connected with the circuit board penetrates through the waterproof joint and then is connected with the outside. The upper shell is arranged on the upper surface of the circuit board and surrounds a circuit on the upper surface of the circuit board, the lower shell is arranged on the lower surface of the circuit board and surrounds a circuit on the lower surface of the circuit board, the silica gel is filled inside the upper shell and the lower shell, and the resin adhesive is filled outside the upper shell and the lower shell and inside the cover plate and the device base. According to the utility model, the upper shell and the lower shell are respectively arranged on the upper surface and the lower surface of the circuit board, and the silica gel is poured into the upper shell and the lower shell, so that stress can be eliminated, welding spots are prevented from being damaged, and the resin adhesive with better bonding performance is poured outside the upper shell and the lower shell, so that the stability of the circuit board after bonding is ensured.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of sensors, specifically to a kind of acceleration sensor used on rail vehicle. BACKGROUND

[0002] In the running process of rail vehicle, a variety of sensors are needed to monitor the vehicle running condition in real time, and acceleration sensor is one of the important sensors, which is used to measure the acceleration of train, to ensure that the train runs in normal state or best state. For example, the invention patent with application number CN202211198090.0 and the name of "a transverse acceleration sensor for motor train unit and its glue pouring method" described in the above patent, the structure of the acceleration sensor includes a circuit board and a shell encapsulated outside the circuit board. The shell is filled with glue to fix the circuit board. The glue used at present is generally hard glue which is hard after solidification, and has stronger adhesion. However, the problem is that in this structure, the stress of the hard glue is large, which can easily damage the solder joints, leading to poor contact of the circuit board, and further causing the acceleration sensor to malfunction. The above patent file adopts the method of pouring glue in multiple times to eliminate bubbles, thereby prolonging the service life of the sensor. However, this method requires high operation requirements and has low efficiency. SUMMARY

[0003] The utility model proposes an acceleration sensor to solve the problem that the solder joints of the current acceleration sensor are easily damaged, leading to the failure of the sensor. The acceleration sensor uses stress-free silicone gel for adhesion around the circuit board, and uses conventional hard glue for adhesion in other parts. This design ensures the overall adhesion performance while avoiding stress damage to the solder joints.

[0004] The utility model adopts the following technical means to solve the above problems: an acceleration sensor includes an outermost base and a cover plate, a sealing ring between the base and the cover plate, and a circuit board enclosed in the base and the cover plate. A waterproof connector is provided at one end of the base. The cable connected to the circuit board passes through the waterproof connector and is connected to the outside. The utility model also includes an upper shell that encloses the circuit on the upper surface of the circuit board and a lower shell that encloses the circuit on the lower surface of the circuit board. Silicone gel is filled in the upper shell and the lower shell, and resin glue is filled in the outer part of the upper shell and the lower shell, the inner part of the cover plate and the base. Silicone gel is used in the inner part of the upper shell and the lower shell to eliminate stress, and resin glue is used in the outer part to ensure adhesion strength.

[0005] Further, the wall of the upper shell and the lower shell is provided with a glue injection hole.

[0006] Further, the upper shell and the lower shell are each provided with a fixing plate at one end. The bolt passes through the fixing plate to fix the upper shell and the lower shell to the circuit board. The upper shell, the lower shell and the circuit board can form a whole.

[0007] Further, the internal width of the upper shell and the lower shell at the opening is equal, and is equal to or greater than the width of the circuit board.

[0008] Further, the end of the upper shell and the lower shell is provided with an elongated notch. The gas inside the upper shell or the lower shell escapes from the notch when injecting glue.

[0009] Further, the injection hole is arranged at one end close to the waterproof joint, and the notch is arranged at the end away from the waterproof joint.

[0010] Further, the cable passes through the injection hole of the upper shell.

[0011] Further, the end of the upper shell close to the waterproof joint is provided with a through hole, and the cable passes through the through hole.

[0012] Further, the end of the upper shell close to the waterproof joint is provided with a through hole, and the cable passes through the through hole.

[0013] Further, the fixed plate is located at one end close to the waterproof joint, and the support block is further arranged in the base, and the bolt is connected to the support block after passing through the fixed plate and the circuit board. The support block provides support and fixation for one end of the circuit board.

[0014] The beneficial effects of the present application are:

[0015] 1. The utility model discloses a circuit board waterproof structure, which comprises an upper shell and a lower shell arranged on the upper surface and the lower surface of the circuit board respectively, and a base arranged on the upper shell and the lower shell.

[0016] 2. The upper shell, the lower shell and the circuit board of the utility model can be connected by bolts to form a whole with an internal cavity, so that the silicon gel can be injected into the internal cavity after being assembled into the base, and twice glue injection operations can be realized. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 It is an internal structure schematic view of the first embodiment.

[0018] Figure 2 It is a schematic view of the upper shell and the lower shell arranged on the circuit board of the first embodiment.

[0019] Figure 3 It is a schematic view of the lower shell structure of the first embodiment.

[0020] Figure 4 It is a schematic view of the support block of the second embodiment.

[0021] In the diagram: 1. Base, 2. Cover plate, 21. Support block, 22. Step, 3. Sealing ring, 4. Resin glue, 5. Upper shell, 51. Injection hole, 52. Fixing plate, 53. Raised strip, 54. Notch, 6. Lower shell, 7. Silicone gel, 8. Cable, 9. Circuit board, 10. Waterproof connector. Detailed Implementation

[0022] The present invention will be further described below with reference to the accompanying drawings. The drawings are for illustrative purposes only, representing schematic diagrams only, not actual physical objects, and should not be construed as limiting the scope of this patent. To better illustrate the embodiments of the present invention, some components in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings. Example 1

[0023] An acceleration sensor, such as Figure 1 As shown, the external structure includes a base 1, a cover plate 2, and a waterproof connector 10. The base 1 is hollow, and the cover plate 2 is positioned over the opening of the base 1, with a sealing ring 3 between the cover plate 2 and the base 1. The waterproof connector 10 is located at one end of the base 1, creating a sealed space inside. The internal structure includes a circuit board 9, an upper housing 5 positioned on the upper surface of the circuit board 9, and a lower housing 6 positioned on the lower surface of the circuit board 9. Cables 8 soldered onto the circuit board 9 pass through the upper housing 5 and exit through the waterproof connector 10 to connect to the outside. Silicone gel 7 is poured into the space enclosed by the upper housing 5 and the lower housing 6, while resin glue 4 is poured into other spaces within the base 1. A step 22 is provided at the end of the base 1 furthest from the waterproof connector 10. A bolt passes through one end of the circuit board 9 and is locked onto the step 22, securing the circuit board 9, the upper housing 5, the lower housing 6, and the silicone gel 7 together. In this way, during manufacturing, silicone gel 7 can be first poured into the space enclosed by the upper shell 5, the lower shell 6, and the circuit board 9 to form a whole. Then, this whole is locked and fixed into the base 1. Next, resin 4 is poured into the base 1 so that the resin 4 can fill the periphery of the upper shell 5 and the outer shell 6, completely encasing the upper shell 5, the lower shell 6, and the circuit board. This ensures both the fixed position of the circuit board 9 and its sealing. At the same time, the upper shell 5 and the lower shell 6, which are respectively located on the upper and lower surfaces of the circuit board 9, also serve as shielding, reducing electromagnetic interference to the circuit board 9.

[0024] like Figure 2 and Figure 3As shown, a fixing plate 52 is provided at one end of the upper housing 5 and the lower housing 6 near the waterproof connector 10, and the fixing plate 52 is located at the edge of the opening. Bolts pass through the fixing plate 52 of the upper housing 5, the circuit board 9, and the fixing plate 52 of the lower housing 6 in sequence to connect the upper housing 5, the circuit board 9, and the lower housing 6 into a whole. An injection hole 51 is provided on the side wall of the upper housing 5 and the lower housing 6 near the waterproof connector 10. Silicone gel 7 is injected into the upper housing 5 and the lower housing 6 through the injection hole 51, filling the space between the upper housing 5 and the circuit board 9 and the space between the lower housing 6 and the circuit board 9, so that the upper housing 5, the circuit board 9, and the lower housing 6 form a tight whole, and the circuit board 9 will not shake between the upper housing 5 and the lower housing 6. Meanwhile, a thin strip-shaped notch 54 is provided at the end of the upper housing 5 and the lower housing 6 away from the waterproof connector 10. When silicone gel 7 is injected, gas can escape from the notch 54. However, due to the high viscosity of silicone gel 7, it is difficult for silicone gel 7 to flow out when the notch 54 is not large. Moreover, even if there are gaps between the upper housing 5 and the circuit board 9, and between the lower housing 6 and the circuit board 9, a small amount of silicone gel 7 leaking out from the gaps will not affect the performance of the accelerometer.

[0025] Since the circuit board 9 has a cable 8 soldered on it, the cable 8 can be passed through the glue injection hole 51 of the upper housing 5, or a through hole can be provided at one end of the upper housing 5 near the waterproof connector 10 so that the cable 8 can pass through the dedicated through hole.

[0026] like Figure 2 and Figure 3 As shown, the upper housing 5 has a downward protruding rib 53 along the edge of the opening along the length direction, and the lower housing 6 has an upward protruding rib 53 along the edge of the opening along the length direction. The width of the interior of the opening of the upper housing 5 and the lower housing 6 is equal to or slightly greater than the width of the circuit board 9. When the upper housing 6 and the lower housing 6 are respectively assembled onto the upper and lower surfaces of the circuit board 9, the rib 53 of the upper housing 5 contacts the rib 53 of the lower housing 6, surrounding the circuit board 9, while also preventing the upper housing 5 and the lower housing 6 from tilting to one side. Example 2

[0027] In this embodiment, as Figure 4 As shown, a support block 21 with screw holes can be provided. Bolts pass sequentially through the fixing plate 52 of the upper housing 5, the circuit board 9, and the fixing plate 52 of the lower housing 6, and are then locked to the support block 21. This way, when the circuit board 9 and its entire assembly, after being infused with silicone gel 7, are placed in the base 1, the support block 21 provides support for the circuit board 9. Combined with the step 22 at the other end, this prevents the circuit board 9 from being suspended in mid-air, ensuring that the end of the circuit board 9 furthest from the step 22 will not tilt downwards during the infusion of resin 4. Of course, other methods can also be used to house the circuit board 9 and its entire assembly within the base 1, such as creating a groove in the inner wall of the base 1 so that the end of the circuit board 9 closest to the waterproof connector 10 is inserted into the groove, etc.

[0028] The above embodiments are only used for illustrating the present application, but not limiting the present application. Those skilled in the art can make various changes or transformations without departing from the spirit and scope of the present application. Therefore, all equivalent technical solutions should belong to the protection scope of the present application, and the protection scope of the present application should be defined by the claims.

Claims

1. An acceleration sensor comprising an outermost housing and cover, a seal ring between the housing and cover, and a circuit board enclosed within the housing and cover, a waterproof joint provided at one end of the housing, and a cable connected to the circuit board, the cable passing through the waterproof joint and connected to the outside, characterized in that: The upper shell and the lower shell are arranged at the upper surface and the lower surface of the circuit board to enclose the circuit of the upper surface and the lower surface of the circuit board, and the silica gel is filled in the upper shell and the lower shell, and the resin glue is filled in the inside of the upper shell, the lower shell, the cover plate and the base.

2. The acceleration sensor of claim 1, wherein: The wall of the upper shell and the lower shell is provided with glue injection holes.

3. The acceleration sensor of claim 1, wherein: The upper shell and the lower shell are provided with fixing plates at one end, and the bolts pass through the fixing plates to fix the upper shell and the lower shell to the circuit board.

4. The acceleration sensor of claim 1, wherein: The internal width of the upper shell and the lower shell at the opening is equal, and is equal to or greater than the width of the circuit board.

5. The acceleration sensor of claim 2, wherein: The end of the upper shell and the lower shell is provided with an elongated notch.

6. The acceleration sensor of claim 5, wherein: The glue injection hole is arranged at one end close to the waterproof joint, and the notch is arranged at the end away from the waterproof joint.

7. The acceleration sensor of claim 2, wherein: The cable passes through the glue injection hole of the upper shell.

8. The acceleration sensor of claim 1, wherein: The end of the upper shell close to the waterproof joint is provided with a through hole, and the cable passes through the through hole.

9. The acceleration sensor of claim 1, wherein: The base is provided with a step at the end away from the waterproof joint, and the bolt is locked and fixed to the step at one end of the circuit board.

10. The acceleration sensor of claim 3, wherein: The fixing plate is located at one end close to the waterproof joint, and the base is further provided with a support block, and the bolt is connected to the support block after passing through the fixing plate and the circuit board.

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