Pressure sensor

Abstract

The invention provides a pressure sensor, and relates to the technical field of sensors, the pressure sensor comprises a shell, the shell comprises a first shell and a second shell, and one end of the second shell is fixedly connected with the first shell; the pressure sensing unit is provided with a pressure sensing channel, the pressure sensing unit comprises a pressure sensing port, a pressure sensing base and a pressure sensing chip which are fixedly connected together, a containing cavity is defined by the shell and the pressure sensing base, and the pressure sensing port and the pressure sensing chip are located in the containing cavity; the support is located in the containing cavity, one end of the support is fixedly connected to the pressure sensing base, and the pressure sensing port is located in the support; the circuit board is positioned in the accommodating cavity and is arranged on the bracket; the pressure sensor comprises a first shell and a second shell, the first shell is provided with an inner side wall, the plugging assembly comprises a plastic part and a conduction part located in the plastic part, at least part of the plastic part is attached to the inner side wall of the first shell, and the pressure sensor is convenient to assemble and has good stability.

Description

Technical Field

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

[0002] In the hydraulic control systems of industrial and engineering machinery, pressure sensors are needed to monitor the system pressure in real time and feed it back to the control unit. The hydraulic pressure sensors currently used in the market are complex in design and high in cost. Usually the sensor requires two PCB circuit boards, upper and lower, and terminals connecting the two PCB circuit boards. In addition, since there is no reliable electrical grounding between the PCB circuit board and the sensor housing, a separate design is required for the PCB circuit board grounding. Since the hydraulic control system requires multiple sensors, the high cost of sensors has become one of the pain points of concern in the industry. Summary of the invention

[0003] The purpose of the present invention is to overcome the defects of the prior art and provide a pressure sensor which can solve the problems of complex structural design and high cost of pressure sensors used in hydraulic control systems in the prior art.

[0004] In order to achieve the above purpose and other purposes, the present invention is implemented by including the following technical solutions: The present invention provides a pressure sensor, which includes: a shell, the shell includes a first shell and a second shell, one end of the second shell is fixedly connected to the first shell; a pressure sensing unit, having a pressure sensing channel, one end of the pressure sensing unit is fixedly connected to the other end of the second shell, the pressure sensing unit includes a pressure sensing port, a pressure sensing base and a pressure sensing chip fixed together, the shell and the pressure sensing port enclose a receiving cavity, the pressure sensing base and the pressure sensing chip are located in the receiving cavity; a bracket, located in the receiving cavity, one end of the bracket is fixedly connected to the pressure sensing port, and the pressure sensing base is located in the bracket; a circuit board, located in the receiving cavity and arranged on the bracket; and a connector assembly, arranged in the receiving cavity and located above the circuit board, the connector assembly includes a plastic part and a conductive part located inside the plastic part, the plastic part is at least partially in contact with the inner side wall of the first shell, and the circuit board is electrically connected to the conductive part and the pressure sensing chip.

[0005] The present invention designs a pressure sensor, which greatly simplifies the number of sensor components and the assembly process. The sensor is composed of a pressure sensing unit, an electrical conditioning module, a connector assembly, an elastic member, a housing and other main components. The pressure sensing unit is composed of a split pressure sensing end and a pressure sensing chip.

[0006] The split pressure-sensing end can ensure the uniform design and materials of the pressure-sensing base, and the pressure-sensing port can be customized, which has greater cost advantages. In addition to the pressure-sensing feature, the pressure-sensing port also integrates the installation thread interface, sealing interface, and installation hexagonal features. At the same time, an integrated throttle valve can be optionally equipped, making the sensor more resistant to the system's rapid pressure pulses.

[0007] The electrical conditioning module is mainly composed of electronic components such as a metal bracket, a circuit board, and a conditioning chip. The small flange contact piece on the bracket has a grounding function. In addition, it can overcome the elastic force to fix the shell during assembly. The metal bracket supports the PCB and provides an interface for welding with the pressure-sensing unit. At the same time, the metal bracket welded with the pressure-sensing unit can meet the grounding problem of the PCB, and there is no need to design a separate feature for grounding.

[0008] There is a small window on the PCB to provide space for the electrical connection between the pressure-sensing chip and the PCB. At the same time, there are several circular copper leaks on the PCB for electrical connection with the elastic parts. In order to meet the mechanical strength of the PCB under the condition of maximum compression of the elastic parts, the support surface of the support frame is usually arranged near the bottom of the copper leak. This support interface for the PCB can not only support the PCB well, but also leave enough space for electrical components on both sides of the PCB, so that the sensor only needs one PCB, which greatly simplifies the design and saves costs.

[0009] The connector assembly is formed by bonding a metal shell and a plastic part. There are boss features on the plastic part to ensure the relative position of the plastic part and the metal shell. The plastic part also has several boss inner holes, and the conductive parts (pins) are exposed at the bottom of the holes. The plastic part also plays a role in stabilizing the elastic part, ensuring the installation position of the elastic part and maintaining a stable state during operation. The metal shell uses a split shell. In comparison, the cost of the split shell is more advantageous. The circular second shell can be used as a mold part and formed by deep drawing. The first shell with threads is machined, and the first shell and the second shell are fixed and sealed by welding. The second shell and the pressure-sensing unit are also fixed and sealed by welding, while the one-piece solution is formed by overall machining, and the cost per piece is higher. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 Shown is a schematic structural diagram of the pressure sensor of the present invention.

[0011] Figure 2 Shown is a cross-sectional view of a pressure sensor of the present invention.

[0012] Figure 3 Shown is a schematic structural diagram of the pressure sensing unit of the present invention.

[0013] Figure 4Shown is an exploded view of the pressure sensing unit of the present invention.

[0014] Figure 5 Shown is a schematic structural diagram of the pressure-sensitive base of the present invention.

[0015] Figure 6 Shown is a schematic diagram of the partial structure of the pressure sensor of the present invention.

[0016] Figure 7 Shown is an electrical connection diagram of the pressure sensor of the present invention.

[0017] Numbers in the figure: 1-housing, 11-first housing, 12-second housing, 11a-first thread; 2-pressure sensing unit, 21-pressure sensing port, 21a-second thread, 21b-outer edge positioning step, 21b1-third ring, 21b2-fourth ring, 21b3-fifth ring, 21c-positioning column, 21d-annular groove, 21e-center positioning step, 21e1-first ring, 21e2-second ring, 22-pressure sensing base, 221-step notch, 23-pressure sensing chip; 3- bracket, 31- bracket body, 32- support plate, 33- baffle, 34- through hole, 35- contact sheet, 36- positioning port; 4-circuit board, 41-opening, 42-copper leakage opening; 5-connector assembly, 51-plastic part, 52-conducting part, 53-boss, 54-inner hole, 55-limiting column; 6- elastic member; C-accommodating chamber, T-pressure sensing channel, V-throttle port. DETAILED DESCRIPTION

[0018] See also Figures 1 to 7 The following describes the embodiments of the present invention through specific examples. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, 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.

[0019] like Figure 1 and Figure 2As shown, the present invention discloses a pressure sensor, which includes a shell 1, which is a hollow shell with an inner cavity. The shell 1 includes a first shell 11 and a second shell 12. The bottom of the first shell 11 and the top of the second shell 12 are fixedly connected. The first shell 11 includes a plug end 112 and a main body end 111. The outer diameter of the main body end 111 can be equal to the outer diameter of the second shell 12, and the outer diameter of the plug end 112 can be smaller than the outer diameter of the second shell 12. A first thread 11a is provided on the outer peripheral wall of the plug end 112, and the first thread 11a can facilitate the interface connection with the signal output end.

[0020] like Figures 2 to 4 The pressure sensor includes a pressure sensing unit 2, in which a pressure sensing channel T is arranged. The pressure sensing unit 2 includes a pressure sensing port 21, a pressure sensing base 22 and a pressure sensing chip 23 connected together. The bottom outer wall of the pressure sensing port 21 is provided with a second thread 21a, and the second thread 21a is convenient for connecting with the input interface of the pressure medium. The pressure sensing port 21 is provided with an annular groove 21d above the second thread 21a, and a sealing ring can be arranged in the annular groove 21d. The top of the pressure sensing port 21 is provided with a positioning step, and the positioning step includes a center positioning step 21e and an outer edge positioning step 21b. The center positioning step 21e includes a first ring 21e1 and a second ring 21e2 whose outer diameters increase from top to bottom, and the first ring 21e1 is located above the second ring 21e2. The outer edge positioning step 21b includes a third ring 21b1, a fourth ring 21b2 and a fifth ring 21b3 whose outer diameters increase from top to bottom, and a positioning column 21c is provided at the outer edge positioning step 21b, and the positioning column 21c is provided between the third ring 21b1 and the fourth ring 21b2.

[0021] like Figure 3 and Figure 5 As shown, the bottom of the pressure-sensing base 22 has a stepped notch 221 , and the stepped notch 221 and the center positioning step 21 e are matched, positioned, and fixedly connected, such as by laser welding, and the top of the pressure-sensing base 22 is provided with the pressure-sensing chip 23 .

[0022] like Figure 2 As shown, the housing 1 and the pressure sensing port 21 together form a containing chamber C, and the bottom of the pressure sensing channel T may be provided with a throttle port V with a reduced inner diameter.

[0023] like Figure 2 and Figure 4As shown, the bottom of the second shell 12 can be fixedly connected to the outer edge positioning step 21b. Specifically, the second shell 12 is located between the fourth ring 21b2 and the fifth ring 21b3. Furthermore, the bottom of the second shell 12 is located on the fifth ring 21b3, and the bottom end of the inner cavity side wall of the second shell 12 is positioned against the fourth ring 21b2.

[0024] like Figure 2 and Figure 4 As shown, the pressure sensor includes a bracket 3, and the bracket 3 can be a cylindrical structure with a cavity. The bracket 3 is located in the accommodating cavity C, and the bottom of the bracket 3 can be fixedly connected to the outer edge positioning step 21b. Specifically, the bracket 3 is located between the third ring 21b1 and the fourth ring 21b2. For example, the bottom of the bracket 3 is located on the fourth ring 21b2, and the side wall of the bottom cavity of the bracket 3 is attached to the third ring 21b1. The pressure sensing base 22 can be located in the cavity of the bracket 3.

[0025] like Figure 6 and Figure 7 As shown, the bottom of the bracket 3 is provided with a positioning hole 36 matching the positioning column 21c, the bracket 3 includes a bracket body 31, the top of the bracket body 31 is provided with a plurality of support plates 32 bent toward the center of the inner cavity, a baffle 33 is provided between the support plates 32, and a plurality of through holes 34 are provided on the side wall of the bracket body 31, and a plurality of protruding contact pieces 35 are provided at the through holes 34, and the contact pieces 35 are in contact with the inner side wall of the second shell 12 to achieve grounding. The contact piece 35 and the shell 1 are interference fit, which can avoid the problem of installation inconvenience caused by the resistance of the elastic member 6 during installation.

[0026] like Figure 2 and Figure 7 As shown, the pressure sensor includes a circuit board 4, which is located in the accommodating cavity C and is arranged on the bracket 3. Specifically, the circuit board 4 can be arranged on the support plate 32 and located in the baffle 33. An opening 41 can be arranged in the middle of the circuit board 4, and the opening 41 can facilitate the electrical connection between the circuit board 4 and the pressure sensing chip 23. The circuit board 4 is also provided with a plurality of copper leakage openings 42.

[0027] like Figure 2 and Figure 6As shown, the pressure sensor includes a connector assembly 5, the connector assembly 5 includes a plastic part 51, the plastic part 51 can be made of polymer plastic material, the plastic part 51 can be at least partially attached to the inner wall of the first shell 11, the attachment can include bonding, the connector assembly 5 includes a conductive part 52 arranged inside the plastic part 51, further, the connector assembly 5 can be integrally injection molded, the conductive part 52 can be electrically connected to the circuit board 4, and a limiting column 55 is provided at the bottom of the plastic part 51, the limiting column 5 5 can be provided with an elastic member 6, and the elastic member 6 can be a spring, a spring, a conductive foam, etc., one end of the elastic member 6 contacts the circuit board 4, and the other end of the elastic member 6 contacts the conductive member 52, and the elastic member 6 is in a compressed state. The support plate 32 can be provided at the bottom surface of the copper leakage opening 42. The support structure provided in this way can not only support the circuit board 4 well, but also leave enough space for electrical components on both sides of the circuit board 4, so that the sensor only needs one PCB circuit board 4, which greatly simplifies the design and saves costs.

[0028] like Figure 6 As shown, the upper surface of the plastic part 51 located on the inner top wall of the main body end 111 of the first shell 11 has a boss 53 and an inner hole 54. The boss 53 and the inner hole 54 can facilitate stabilizing the relative position of the plastic part 51 and the conductive part 52 during injection molding, and the conductive part 52 is exposed at the bottom of the inner hole 54. The plastic part 51 can also stabilize the elastic part 6, ensuring the installation position of the elastic part 6 and maintaining a stable state during operation. The boss 53 is also conducive to ensuring the bonding thickness when the first shell 11 and the plastic part 51 are bonded, ensuring that the first shell 11 and the plastic part 51 have a stable bonding force.

[0029] The assembly process of the present invention can first weld the pressure-sensing base 22 and the pressure-sensing port 21, then weld the bracket 3 to the pressure-sensing port 21, then assemble the circuit board 4, and electrically connect the circuit board 4 and the pressure-sensing chip 23 by wire bonding, press the integrally injection-molded first shell 11 and the connector assembly 5 with the elastic part 6 installed on the circuit board 4, and finally weld the first shell 11 and the second shell 12.

[0030] Therefore, the present invention 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 present invention, and are not intended to limit the present invention. Anyone familiar with the technology can modify or change the above embodiments without violating the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A pressure sensor, characterized in that: The pressure sensor comprises: A housing, the housing comprising a first housing and a second housing, one end of the second housing being fixedly connected to the first housing; A pressure-sensing unit having a pressure-sensing channel, one end of the pressure-sensing unit being fixedly connected to the other end of the second shell, the pressure-sensing unit comprising a pressure-sensing port, a pressure-sensing base and a pressure-sensing chip fixedly connected together, the shell and the pressure-sensing port forming a receiving cavity, the pressure-sensing base and the pressure-sensing chip being located in the receiving cavity; A bracket is located in the accommodating cavity, one end of the bracket is fixedly connected to the pressure sensing port, and the pressure sensing base is located in the bracket; A circuit board is located in the accommodating cavity and is arranged on the bracket; A connector assembly is arranged in the accommodating cavity and located above the circuit board. The connector assembly includes a plastic part and a conductive part located inside the plastic part. The plastic part is at least partially attached to the inner wall of the first shell. The circuit board, the conductive part and the pressure-sensitive chip are electrically connected.

2. The pressure sensor according to claim 1, characterized in that: The top of the pressure sensing port includes a central positioning step and an outer edge positioning step, the pressure sensing base is fixedly connected to the central positioning step, and the second shell and the bracket are fixedly connected to the outer edge positioning step.

3. The pressure sensor according to claim 2, characterized in that: The center positioning step includes a first ring and a second ring. The bottom of the pressure-sensing base is provided with a step notch, and the step notch matches the first ring and the second ring.

4. The pressure sensor according to claim 2, characterized in that: The outer edge positioning step includes a third ring, a fourth ring and a fifth ring. The bottom of the bracket is arranged between the third ring and the fourth ring. The bottom of the second shell is arranged between the fourth ring and the fifth ring.

5. The pressure sensor according to claim 1, characterized in that: The bracket includes a bracket body, the top of the bracket body is bent toward the center to form a support plate, a baffle is arranged between the support plates, a through hole is opened on the side wall of the bracket body, a contact sheet is arranged on the through hole, and the contact sheet is in contact with the second shell.

6. The pressure sensor according to claim 1, characterized in that: The first shell includes a plug end and a main body end, the main body end is connected to the second shell, and the plastic part has a boss and an inner hole on the surface close to the inner top wall of the main body end.

7. The pressure sensor according to claim 1, characterized in that: The pressure sensor includes an elastic member, and two ends of the elastic member are in contact with the conductive member and the circuit board respectively.

8. The pressure sensor according to claim 7, characterized in that: The bottom of the plastic part is provided with a limiting column, and the elastic part is located in the limiting column.

9. The pressure sensor according to claim 1, characterized in that: A throttle port with a reduced inner diameter is arranged in the pressure sensing channel.

10. The pressure sensor according to claim 6, characterized in that: The conductive member is in communication with the bottom of the inner hole.

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