Pressure sensor

Abstract

The utility model provides a pressure sensor, and relates to the technical field of sensors, the pressure sensor comprises a housing having a cavity; one end of the supporting piece is fixedly connected with the shell, the supporting piece comprises a base, a through hole is formed in the base, a positioning ring is arranged on the periphery of the through hole, and a boss is arranged between the positioning ring and the through hole; one end of the connecting piece is fixedly connected with the other end of the shell; the pressure sensing unit is provided with a pressure sensing channel, one end of the pressure sensing unit is arranged in the through hole, and the other end of the pressure sensing unit is fixedly connected with the base; the circuit board is electrically connected with the pressure sensing unit and the connecting piece, and the pressure sensor is simple in assembly, low in manufacturing cost and good in installation torque resistance.

Description

Technical Field

[0001] The utility model relates to the technical field of sensors, in particular to a pressure sensor. Background Art

[0002] In the high-pressure rail pressure sensor of gasoline direct injection or diesel common rail, gasoline direct injection system and diesel common rail system are common fuel supply systems for internal combustion engines. In order to improve the combustion efficiency of fuel and reduce emissions, it is usually necessary to pressurize the fuel molecules to hundreds or even thousands of atmospheres, so that the injection system can atomize the fuel as much as possible and enter the cylinder in the form of fine droplets for combustion. In order to accurately control the fuel supply pressure under different working conditions, a pressure sensor is required to provide a pressure signal to the ECU (electronic control unit) in real time, so that the ECU can control the fuel pressure more accurately and adjust the control strategy in time under different working conditions.

[0003] The current fuel high-pressure pressure sensor uses a separate stamped circuit board support and ground bracket. During the assembly process, the bracket needs to be fixed to the pressure port through laser welding. At the same time, an additional separate hexagonal shell is required. This hexagonal shell can be integrated on the pressure port or fixed to the pressure port with a separate hexagonal flange through welding. Regardless of which solution is used, there are a series of problems such as many parts, complex assembly process, and difficult tolerance control. Utility Model Content

[0004] The utility model aims to overcome the defects of the prior art and provides a pressure sensor to simplify the assembly process and increase the reliability of the sensor.

[0005] In order to achieve the above purpose and other purposes, the utility model is implemented by including the following technical solutions: The utility model provides a pressure sensor, which includes: a shell having a cavity; a support member, one end of the support member is fixedly connected to one end of the shell, the support member includes a base, a through hole is provided on the base, a positioning ring is provided on the periphery of the through hole, and a boss is provided between the positioning ring and the through hole; a connecting member, one end of the connecting member is fixedly connected to the other end of the shell, the connecting member, the base and the shell are surrounded to form a receiving cavity, the positioning ring and the convex The platform is located in the accommodating cavity; the pressure-sensing unit has a pressure-sensing channel, one end of the pressure-sensing unit is arranged in the through hole, and the other end of the pressure-sensing unit is fixedly connected to the base; and the circuit board is located in the accommodating cavity and arranged on the boss, the circuit board is electrically connected to the pressure-sensing unit and the connecting member, the height of the boss is higher than the height of the positioning ring, the pressure-sensing unit includes a pressure-sensing cavity and a pressure-sensing chip located at the top of the pressure-sensing cavity, the pressure-sensing chip is electrically connected to the circuit board, the outer side wall of the pressure-sensing cavity is provided with a positioning step, and the base is fixedly connected to the positioning step.

[0006] In one embodiment, the outer side wall of the positioning ring is in contact with the bottom of the side wall of the housing cavity.

[0007] In one embodiment, the pressure sensor includes an elastic member, the elastic member is located in the accommodating cavity, and two ends of the elastic member are electrically connected to the connecting member and the circuit board respectively.

[0008] In one embodiment, the housing is a hollow cylinder.

[0009] In one embodiment, the connecting member includes a plastic member and a conductive member located inside the plastic member, and the conductive member is in contact with the elastic member.

[0010] In one embodiment, the support member is integrally formed, and the base has a hexagonal structure.

[0011] In one embodiment, an electrical connection is formed between the boss and the circuit board.

[0012] The utility model provides a pressure sensor. Compared with the prior art, the utility model has the following beneficial effects: by optimizing the internal design, a traditional hexagonal shell and a circuit board bracket are made into an integrated hexagonal support member, and a boss for supporting the circuit board is provided, and the support member and the PCB circuit board are connected by SMT or conductive adhesive, so as to achieve a stable mechanical and grounding electrical connection.

[0013] A positioning ring is provided on the support member. During the assembly process, the support member and the pressure-sensing unit are assembled together in a certain orientation through laser welding. Subsequently, only conventional wire bonding, gluing, elastic parts and shell assembly are required to complete the overall assembly of the sensor. This solution is more friendly to applying installation torque to the sensor during installation because it is designed by combining the hexagonal shell, flange and circuit board support frame in the prior art. The risk of failure during installation is reduced, and the shell thickness requirement is also reduced because it does not need to bear the installation torque. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 Shown is a schematic structural diagram of the pressure sensor of the utility model.

[0015] Figure 2 Shown is a cross-sectional view of the pressure sensor of the present invention.

[0016] Figure 3 Shown is the electrical connection diagram of the pressure sensor of the utility model.

[0017] Figure 4 Shown is a schematic structural diagram of the support member of the utility model.

[0018] Numbers in the figure:

[0019] 1-shell, 11-cavity;

[0020] 2-support member, 21-base, 21a-through hole, 22-positioning ring, 23-boss;

[0021] 3-connecting part, 31-plastic part, 32-conducting part, C-accommodating cavity;

[0022] 4-pressure sensing unit, 41-pressure sensing cavity, 42-pressure sensing chip, 41a-pressure sensing channel, A-pressure sensing entrance, 41c-top platform, 41b-positioning step;

[0023] 5- Circuit board;

[0024] 6-Elastic parts. DETAILED DESCRIPTION

[0025] See also Figures 1 to 4 The following describes the implementation of the present invention through specific examples. Those skilled in the art can easily understand other advantages and functions of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific implementations, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0026] like Figure 1 and Figure 3 As shown, the utility model provides a pressure sensor, the pressure sensor comprises a housing 1, the housing 1 is a thin-walled hollow cylinder, the housing 1 has a cavity 11, the thickness of the housing 1 is 0.2-0.3 mm, and the housing 1 can be a metal housing 1.

[0027] like Figure 2 and Figure 4 As shown, the pressure sensor includes a support member 2, one end of which is fixedly connected to one end of the shell 1, and the support member 2 includes a base 21, which can be a hexagonal structure. A through hole 21a is provided on the base 21, and the through hole 21a can be provided at the center position of the base 21. The support member 2 includes a positioning ring 22, and the positioning ring 22 can be located on the upper surface of the base 21 and arranged on the periphery of the through hole 21a. A boss 23 is provided between the positioning ring 22 and the through hole 21a, and the outer side of the boss 23 can be abutted against the inner side wall of the positioning ring 22. The boss 23 is provided on the base 21, and the height of the boss 23 is higher than the height of the positioning ring 22. The boss 23 can be 4 bosses 23 evenly distributed along the circumference of the positioning ring 22, and the support member 2 can be integrally formed.

[0028] like Figure 2 As shown, the pressure sensor includes a connector 3, one end of which is fixedly connected to the top of the housing 1, and can be, for example, integrally formed by injection molding, and the connector 3 includes a plastic part 31 and a conductive part 32. One end of the conductive part 32 is located in the top plug-in interface of the plastic part 31, and the plastic part 31 and the top of the housing 1 are connected together.

[0029] like Figure 2 As shown, specifically, the housing 1 , the base 21 and the connecting member 3 together form an accommodating cavity C, and the positioning ring 22 and the boss 23 may be located in the accommodating cavity C.

[0030] like Figure 2 As shown, the pressure sensor includes a pressure sensing unit 4, and the pressure sensing unit 4 includes a pressure sensing cavity 41. A pressure sensing channel 41a is arranged in the pressure sensing cavity 41. The bottom of the pressure sensing channel 41a has a pressure sensing entrance A, and the outer side wall of the pressure sensing cavity 41 has a positioning step 41b.

[0031] like Figure 1 , Figure 2 as well as Figure 4As shown, the bottom of the base 21 can be fixedly connected to the pressure sensing unit 4. One end of the shell 1 is fixedly connected to the support member 2. Further, the bottom side wall of the cavity 11 of the shell 1 is abutted against the outer side wall of the positioning ring 22, and the bottom end of the shell 1 is located on the base 21 of the support member 2. The bottom of the base 21 is fixedly connected to the positioning step 41b.

[0032] like Figure 2 As shown, the pressure sensor includes a circuit board 5, the circuit board 5 is located in the accommodating cavity C, the circuit board 5 is arranged on the boss 23, the pressure sensing cavity 41 is provided with a top platform 41c at the top of the pressure sensing channel 41a, the top platform 41c can be located above the through hole 21a and arranged below the circuit board 5, the top platform 41c is located inside the boss 23, and the positioning step 41b is located below the top platform 41c. The other end of the conductive member 32 is electrically connected to the circuit board 5.

[0033] like Figure 2 As shown, in some embodiments, the pressure sensor includes an elastic member 6, which may be located in the accommodating cavity C, one end of the elastic member 6 is electrically connected to the connecting member 3, further the elastic member 6 is in abutment contact with the conductive member 32, and the other end of the elastic member 6 is electrically connected to the circuit board 5. The elastic member 6 may be a spring.

[0034] like Figure 3 As shown, the pressure sensing unit 4 also includes a pressure sensing chip 42, which is located on the top platform 41c of the pressure sensing cavity 41. The pressure sensing chip 42 can be electrically connected to the circuit board 5, and the electrical connection can be wire bonding. The pressure sensing chip 42 is a semiconductor chip that can form a piezoresistive full-bridge Wheatstone bridge.

[0035] like Figure 2 As shown, the boss 23 and the circuit board 5 can form an electrical connection. Specifically, the boss 23 and the circuit board 5 are connected by soldering or conductive adhesive bonding. In some embodiments, the upper surface of the boss 23 can be electroplated to form an electroplating layer to improve the firmness and ease of soldering.

[0036] When assembling the utility model, the bottom of the support member 2 and the positioning step 41b on the pressure sensing cavity 41 can be welded together, the base 21 and the positioning ring 22 of the support member 2 and the bottom of the shell 1 can be welded together, and the top of the shell 1 and the connecting member 3 can be integrally formed by injection molding.

[0037] When the utility model is working, the pressure-sensitive medium enters the pressure-sensitive channel 41a from the pressure-sensitive inlet A and acts on the top of the pressure-sensitive channel 41a to generate displacement deformation. The displacement deformation signal change is transmitted to the pressure-sensitive chip 42. The resistance change of the pressure-sensitive chip 42 can be collected by the ASIC chip on the circuit board 5, and corresponding signal processing is performed, converted into an electrical signal, and finally output to the client from the elastic member 6 and the conductive member 32.

[0038] Therefore, the utility model effectively overcomes various shortcomings in the prior art and has a high industrial utilization value. The above embodiments are only illustrative of the principles and effects of the utility model, and are not used to limit the utility model. Anyone familiar with this technology can modify or change the above embodiments without violating the spirit and scope of the utility model. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the relevant technical field without departing from the spirit and technical ideas disclosed by the utility model should still be covered by the claims of the utility model.

Claims

1. A pressure sensor, characterized in that: The pressure sensor comprises: a housing having a cavity; A support member, one end of which is fixedly connected to one end of the shell, the support member comprises a base, a through hole is provided on the base, a positioning ring is provided on the periphery of the through hole, and a boss is provided between the positioning ring and the through hole; A connecting member, one end of which is fixedly connected to the other end of the shell, the connecting member, the base and the shell together form an accommodating cavity, and the positioning ring and the boss are located in the accommodating cavity; A pressure-sensing unit having a pressure-sensing channel, one end of the pressure-sensing unit being arranged in the through hole, and the other end of the pressure-sensing unit being fixedly connected to the base; And a circuit board is located in the accommodating cavity and arranged on the boss, the circuit board is electrically connected to the pressure sensing unit and the connecting piece, the height of the boss is higher than the height of the positioning ring, the pressure sensing unit includes a pressure sensing cavity and a pressure sensing chip located at the top of the pressure sensing cavity, the pressure sensing chip is electrically connected to the circuit board, the outer side wall of the pressure sensing cavity is provided with a positioning step, and the base is fixedly connected to the positioning step.

2. The pressure sensor according to claim 1, characterized in that: The outer side wall of the positioning ring is in contact with the bottom of the side wall of the housing cavity.

3. The pressure sensor according to claim 1, characterized in that: The pressure sensor includes an elastic member, the elastic member is located in the accommodating cavity, and two ends of the elastic member are electrically connected to the connecting member and the circuit board respectively.

4. The pressure sensor according to claim 1, characterized in that: The shell is a hollow cylinder.

5. The pressure sensor according to claim 3, characterized in that: The connecting member includes a plastic member and a conductive member located inside the plastic member, and the conductive member is in contact with the elastic member.

6. The pressure sensor according to claim 1, characterized in that: The support member is integrally formed, and the base has a hexagonal structure.

7. The pressure sensor according to claim 1, characterized in that: An electrical connection is formed between the boss and the circuit board.

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