Compact pressure sensor

Abstract

The utility model relates to a compact pressure sensor, which is provided with an elastic body, a metal support ring and a plastic shell, the upper half part of the elastic body extends into the metal support ring, the middle part of the elastic body is annularly fixed with the bottom of the metal support ring, and a metal strain gauge is bonded on the top surface of the elastic body. A PCB electrically connected with the metal strain gauge is arranged in the upper end of the metal supporting ring, the bottom end of the plastic shell is annularly connected with the upper end of the metal supporting ring in a clamped mode, and three terminal jacks distributed in the circumferential direction are formed in the upper end face of the plastic shell. According to the utility model, a metal shell adopted in a conventional pressure sensor is eliminated, the number of parts is reduced, only one-time welding processing is needed, and the yield of products is improved; the full-bridge strain gauges are adopted, so that the utilization space of the PCB is increased, the selection types of chips are increased, the plastic shell and the metal supporting ring are connected in a buckling mode, and the assembly process is simplified.

Description

Technical Field

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

[0002] Pressure sensors are usually composed of pressure sensitive elements and signal processing units. Currently, the electrical connection methods of most pressure sensors generally include connectors, springs, and cables, but these connection methods sometimes cannot meet the needs of product applications with specific special requirements.

[0003] In the structure of the existing pressure sensor, the support ring is arranged in the inner cavity of the shell, the PCB circuit board is fixed to the upper end of the support ring, the pressure-sensitive element is installed in the support ring, the upper end of the pressure-sensitive element is electrically connected to the PCB circuit board, a fixed frame is installed in the inner cavity of the shell, a plug hole is opened on the fixed frame, a connecting terminal is inserted into the plug hole, and the lower end of the connecting terminal is electrically connected to the PCB circuit board. The pressure sensor with such a structure has a large number of parts, a complicated assembly process, a high product height, and a large overall size. During the assembly process, the shell and the pressure-sensitive element, the support ring and the pressure-sensitive element all need to be welded and fixed. Multiple welding can easily increase the probability of product defects, and the strain gauge used is generally a double half-bridge strain gauge, which leads to a large PCB opening, insufficient space, and a small number of chip options. Utility Model Content

[0004] The technical problem to be solved by the utility model is: in order to overcome the deficiencies in the prior art, the utility model provides a compact pressure sensor with compact overall size and simplified assembly process.

[0005] The utility model solves the technical problem by adopting the following technical solution: a compact pressure sensor, comprising an elastomer, a metal support ring and a plastic shell, wherein the upper half of the elastomer extends into the metal support ring, the middle part of the elastomer is annularly fixed to the bottom of the metal support ring, a metal strain gauge is bonded to the top surface of the elastomer, a PCB circuit board electrically connected to the metal strain gauge is arranged in the upper end of the metal support ring, the bottom end of the plastic shell is annularly clamped to the upper end of the metal support ring, and three circumferentially distributed terminal jacks are arranged on the upper end surface of the plastic shell.

[0006] In order to facilitate the positioning of the metal support ring during fixation, the middle part of the elastic body has an annular boss protruding outward from the peripheral wall of the metal support ring, and the bottom of the metal support ring is welded and fixed to the upper surface of the annular boss.

[0007] Preferably, in order to facilitate the selection of a variety of chip types used in the PCB circuit board, the metal strain gauge is a full-bridge strain gauge.

[0008] Furthermore, in order to improve the utilization space of the PCB circuit board, a rectangular hole located directly above the metal strain gauge is opened on the PCB circuit board, and the PCB circuit board is electrically connected to the metal strain gauge through five aluminum wires.

[0009] The outer bottom of the plastic shell has three buckles that are evenly distributed and folded outward. The upper peripheral wall of the metal support ring has three holes corresponding to the buckles. The assembly process of the sensor is simplified by snapping the buckles into the holes.

[0010] Furthermore, the upper part of the metal support ring has three support plates which are evenly distributed in the circumference and folded inwards, and the outer periphery of the PCB circuit board is fixedly connected to the support plates.

[0011] Preferably, in order to facilitate the smooth clamping of the external terminal, the cross-sectional area of ​​the terminal insertion hole gradually decreases from top to bottom.

[0012] The beneficial effects of the utility model are as follows: the utility model cancels the metal shell used in the conventional pressure sensor, the number of parts is reduced, only one welding process is required, and the product quality rate is improved; the full-bridge strain gauge is adopted, so that the utilization space of the PCB circuit board is increased, the types of chip selection are increased, the plastic shell and the metal support ring are connected by a snap-fit ​​method, and the assembly process is simple. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The utility model is further described below in conjunction with the accompanying drawings and implementation modes.

[0014] Figure 1 It is a three-dimensional structural schematic diagram of the utility model.

[0015] Figure 2 It is a cross-sectional structural schematic diagram of the utility model.

[0016] Figure 3 It is a schematic diagram of the connection structure between the PCB circuit board and the metal strain gauge described in the utility model.

[0017] In the figure: 1. elastic body, 1-1. annular boss, 2. metal support ring, 3. plastic housing, 4. metal strain gauge, 5. PCB circuit board, 5-1. rectangular hole, 6. terminal jack, 7. buckle, 8. clamping hole, 9. support plate, 10. aluminum wire. DETAILED DESCRIPTION

[0018] Now the utility model is further described in detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, which only illustrate the basic structure of the utility model in a schematic manner, and therefore only show the components related to the utility model.

[0019] like Figure 1 , Figure 2A compact pressure sensor is shown, comprising an elastomer 1, a metal support ring 2, a PCB circuit board 5 and a plastic shell 3. The upper end of the elastomer 1 has a disc body, and the outer periphery of the middle part of the elastomer 1 has an annular boss 1-1 protruding outward from the peripheral wall of the metal support ring 2. The upper half of the elastomer 1 extends into the metal support ring 2, and the bottom of the metal support ring 2 is welded and fixed to the upper surface of the annular boss 1-1 in the circumferential direction.

[0020] The outer bottom of the plastic shell 3 has three circumferentially evenly distributed and outwardly folded buckles 7, and the upper circumferential wall of the metal support ring 2 has three clip holes 8 corresponding to the buckles 7; the upper end surface of the plastic shell 3 is provided with three circumferentially distributed terminal sockets 6, and the cross-section of the terminal sockets 6 along the axial direction is in the shape of a conical hole, and the cross-sectional areas of the three terminal sockets 6 gradually decrease from top to bottom.

[0021] like Figure 2 , Figure 3 As shown, a metal strain gauge 4 is provided on the surface of the disk body at the upper end of the elastic body 1, and the metal strain gauge 4 adopts a full-bridge strain gauge. Three circumferentially evenly distributed notches are opened on the upper part of the metal support ring 2, and an inwardly folded support plate 9 is provided in each notch. The outer periphery of the PCB circuit board 5 containing the chip is fixedly connected to the support plate 9; a rectangular hole 5-1 located directly above the metal strain gauge 4 is opened on the PCB circuit board 5, and the PCB circuit board 5 is electrically connected to the metal strain gauge 4 through five aluminum wires 10.

[0022] During assembly, first, glass glue is pasted on the surface of the disc at the upper end of the elastomer 1 through a silk screen process, and the metal strain gauge 4 is pasted on the melted glass glue. The glass glue is then sintered through a high-temperature tunnel furnace to sinter the metal strain gauge 4 and the elastomer 1 into one body; then the metal support ring 2 is welded and fixed to the elastomer 1; the metal strain gauge 4 is connected to the PCB circuit board 5 through an aluminum wire 10, and the buckle 7 on the plastic shell 3 is inserted into the clamping hole 8 on the metal support ring 2, and the plastic shell 3 is clamped to the upper end of the metal support ring 2.

[0023] The utility model eliminates the metal shell used in conventional pressure sensors, thereby reducing the number of parts and components, requiring only one welding process, and improving the quality rate of the product; compared with the double half-bridge strain gauge used in the existing pressure sensor, the metal strain gauge 4 adopts a full-bridge strain gauge, which increases the utilization space of the PCB circuit board 5 and expands the selectivity of chip types; the plastic shell 3 is connected to the metal support ring 2 by a snap-fit ​​method, which simplifies the assembly process and improves work efficiency.

[0024] Based on the above ideal embodiments of the utility model, the relevant staff can make various changes and modifications without departing from the technical concept of the utility model through the above description. The technical scope of the utility model is not limited to the content of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A compact pressure sensor comprising an elastic body (1), a metal support ring (2) and a plastic housing (3), wherein: The upper half of the elastic body (1) extends into the metal support ring (2), the middle part of the elastic body (1) is circumferentially fixed to the bottom of the metal support ring (2), a metal strain gauge (4) is bonded to the top surface of the elastic body (1), a PCB circuit board (5) electrically connected to the metal strain gauge (4) is provided in the upper end of the metal support ring (2), the bottom end of the plastic housing (3) is circumferentially clamped to the upper end of the metal support ring (2), and three circumferentially distributed terminal jacks (6) are provided on the upper end surface of the plastic housing (3).

2. The compact pressure sensor according to claim 1, characterized in that: The middle part of the elastic body (1) has an annular boss (1-1) protruding outward from the peripheral wall of the metal support ring (2), and the bottom of the metal support ring (2) is welded and fixed to the upper surface of the annular boss (1-1).

3. The compact pressure sensor according to claim 1, characterized in that: The metal strain gauge (4) is a full-bridge strain gauge.

4. The compact pressure sensor according to claim 3, characterized in that: The PCB circuit board (5) is provided with a rectangular hole (5-1) located directly above the metal strain gauge (4), and the PCB circuit board (5) is electrically connected to the metal strain gauge (4) via five aluminum wires (10).

5. The compact pressure sensor according to claim 1, characterized in that: The outer bottom of the plastic shell (3) has three buckles (7) that are evenly distributed in the circumference and folded outwards, and the upper peripheral wall of the metal support ring (2) has three buckle holes (8) corresponding to the buckles (7).

6. The compact pressure sensor according to claim 5, characterized in that: The upper part of the metal support ring (2) has three support plates (9) that are evenly distributed in the circumference and folded inwards, and the outer periphery of the PCB circuit board (5) is fixedly connected to the support plates (9).

7. The compact pressure sensor according to claim 1, characterized in that: The cross-sectional area of ​​the terminal insertion hole (6) gradually decreases from top to bottom.

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