Pressure Sensor with Inner Shield and Its Assembly Method

Abstract

The present invention discloses a pressure sensor with an inner shielding cover and an assembly method thereof. The pressure sensor includes a housing and an end cover; a pressure sensing element is disposed in the inner cavity of the housing, and a shielding cover is provided outside the pressure sensing element; the shielding cover includes a surrounding ring portion and a pressing edge portion, the surrounding ring portion is correspondingly surrounded and attached to the peripheral side of the pressure sensing element, and the pressing edge portion is correspondingly pressed and attached to the top edge of the pressure sensing element; the top of the inner cavity is an opening, and there is a pressure measuring port at the bottom of the inner cavity; the bottom of the pressure sensing element has a pressure sensing surface, the pressure sensing surface is pressed against the bottom of the inner cavity through a sealing ring, and the pressure sensing surface is opposite to the pressure measuring port; the end cover seals the opening at the top of the inner cavity, and the end cover is correspondingly pressed on the pressing edge portion of the shielding cover. The present invention enables the shielding cover in the pressure sensor not to be subjected to riveting, so as to improve the production efficiency of the pressure sensor.

Description

Technical Field

[0001] The present invention relates to the technical field of sensors, and particularly to a pressure sensor with an inner shielding cover and an assembly method thereof. Background Art

[0002] During the operation of a pressure sensor, an instantaneous overvoltage higher than the normal operating voltage may be generated. Therefore, a metal shielding cover structure is usually provided on the ceramic core inside the pressure sensor to protect the ceramic core and prevent the ceramic core from being broken down and failing due to the instantaneous overvoltage. Most of the existing metal shielding covers are wrapped around the ceramic core and form a riveted and bent edge after riveting, and are fixed to the end cover of the pressure sensor through the riveted and bent edge. In addition, the housing of the pressure sensor also needs to be fixed to the end cover by riveting. Therefore, during the production process of the pressure sensor, two riveting operations are required, resulting in low production efficiency and room for improvement.

[0003] Refer to the attached Figure 5 As shown in the figure, the pressure sensor further includes a circuit board, on which there are two sub-boards connected by a strip. The two sub-boards are respectively welded to the ceramic core and the end cover. If the entire shielding cover is a whole, the shielding cover must be installed on the ceramic core in advance before the ceramic core, the end cover, and the circuit board are welded. However, corresponding welding jigs are required during the welding process of the ceramic core, the end cover, and the circuit board. Therefore, installing the shielding cover in advance will cause the original welding jigs to become inapplicable under the interference of the shielding cover, resulting in the need to modify the welding jigs and even the entire welding system, with a relatively high modification cost. Summary of the Invention

[0004] Object of the Invention: In order to overcome the deficiencies in the prior art, the present invention provides a pressure sensor with an inner shielding cover and an assembly method thereof, enabling the shielding cover inside the pressure sensor not to require riveting, thereby improving the production efficiency of the pressure sensor and eliminating the need to modify the welding system.

[0005] Technical solution: To achieve the above object, the pressure sensor with an inner shielding cover of the present invention includes a housing and an end cap; there is a pressure sensing element in the inner cavity of the housing, and a shielding cover is provided outside the pressure sensing element; the shielding cover includes a surrounding ring portion and a pressing edge portion, the surrounding ring portion is correspondingly surrounded and attached to the peripheral side of the pressure sensing element, and the pressing edge portion is correspondingly pressed and attached to the top edge of the pressure sensing element; the top of the inner cavity is an opening, and there is a pressure measurement port at the bottom of the inner cavity; the bottom of the pressure sensing element has a pressure sensing surface, the pressure sensing surface is pressed against the bottom of the inner cavity through a sealing ring, and the pressure sensing surface is opposite to the pressure measurement port; the end cap seals the opening at the top of the inner cavity, and the end cap is correspondingly pressed on the pressing edge portion of the shielding cover; the shielding cover is formed by splicing two or more than two splicing blocks, at least one splicing block is made of insulating plastic and is called a plastic splicing block; at least one splicing block is made of metal and is called a metal splicing block; the plastic splicing block is separated between the housing and the metal splicing block; both the metal splicing block and the plastic splicing block are arc-shaped; after each splicing block is spliced into a shielding cover, the metal splicing blocks are connected end to end to form a metal shielding ring; the metal shielding ring is correspondingly surrounded outside the pressure sensing element; the plastic splicing blocks are connected end to end to form a plastic shielding ring; the pressure sensing element is a ceramic core body, the metal shielding ring is located inside the shielding cover, and the metal shielding ring is tightly attached to the outer contour surface of the ceramic core body; the plastic shielding ring is located outside the shielding cover, and the plastic shielding ring is tightly attached to the inner wall of the inner cavity; a circular card slot is formed on the inner side of the plastic shielding ring, the metal shielding ring is embedded in the circular card slot, and the metal shielding ring is attached to the outer contour surface of the ceramic core body through the slot opening of the circular card slot; and the metal shielding ring can rotate in the circular card slot so that the splicing seams of the plastic splicing blocks and the splicing seams of the metal splicing blocks are staggered from each other.

[0006] Furthermore, the present invention also provides an assembly method for the pressure sensor with an inner shielding cover. The pressure sensor further includes a circuit board. There are two sub-boards connected by a board strip on the circuit board. After the two sub-boards are respectively welded to the ceramic core body and the end cap, each metal splicing block is respectively inserted into the circular card slot of each plastic splicing block, and then the plastic splicing blocks and the metal splicing blocks are spliced around the board strip. After the splicing is completed, the metal shielding ring is rotated to stagger the splicing seams of the metal splicing blocks and the splicing seams of the plastic splicing blocks to prevent the shielding cover from falling apart; then a sealing ring is installed on the housing, the housing is sleeved outside the ceramic core body, and the housing is riveted so that a riveted bending portion is formed on the housing, and the riveted bending portion is correspondingly pressed on the end cap.

[0007] Beneficial effects: The pressure sensor with an inner shielding cover of the present invention and its assembly method have the following beneficial effects:

[0008] 1) The shielding cover is composed of a surrounding ring portion and a pressing edge portion. The surrounding ring portion surrounds the ceramic core body, and the end cap presses the pressing edge portion on the ceramic core body. Therefore, the shielding cover does not need to be riveted, thereby improving the production efficiency of the pressure sensor;

[0009] 2) The shielding cover is composed of several assembled pieces, so it can be assembled on the ceramic core after the end cap, ceramic core and circuit board are welded; in this way, the influence of installing the shielding cover in advance on the welding process can be avoided, thus preserving the original welding method;

[0010] 3) The inner side of the shielding cover is a metal assembled piece, and the outer side is a plastic assembled piece; the metal assembled piece has a better shielding effect, and the plastic assembled piece is separated between the metal assembled piece and the metal shell to prevent the metal assembled piece from directly conducting with the metal shell;

[0011] 4) The metal assembled pieces form a metal shielding ring, and the plastic assembled pieces form a plastic shielding ring; the metal shielding ring can rotate in the annular card slot inside the plastic shielding ring, so that the seams of the metal assembled pieces and the seams of the plastic assembled pieces are staggered from each other, making the assembled shielding cover not easy to fall apart and having good structural stability. Description of the Drawings

[0012] Attached Figure 1 is a schematic diagram of the internal structure of the pressure sensor;

[0013] Attached Figure 2 is a schematic diagram of the shielding cover composed of a single component;

[0014] Attached Figure 3 is a schematic diagram of the shielding cover assembled by assembled pieces;

[0015] Attached Figure 4 is a schematic diagram of the structure of the plastic assembled piece and the metal assembled piece;

[0016] Attached Figure 5 is a schematic diagram after the end cap, ceramic core and circuit board are welded;

[0017] Attached Figure 6 is a schematic diagram of the assembly of the shielding cover. Detailed Embodiment

[0018] The present invention will be further described below with reference to the drawings.

[0019] As described in the attached Figures 1 to 6 pressure sensor with an internal shielding cover, the pressure sensor includes a housing 1 and an end cap 2. The housing 1 has an inner cavity 8, and a pressure sensing element 3 is arranged in the inner cavity 8 of the housing 1. A shielding cover 4 is arranged outside the pressure sensing element 3. Specifically, the pressure sensing element 3 is a ceramic core. As shown in the attached Figure 1 figure, the shielding cover 4 includes a surrounding ring part 6 and a pressing edge part 7. The surrounding ring part 6 is correspondingly pasted around the circumference of the ceramic core, and the pressing edge part 7 is correspondingly pasted on the top edge of the ceramic core.

[0020] The top of the inner cavity 8 is open, and there is a pressure measuring port 9 at the bottom of the inner cavity 8. The bottom of the ceramic core has a pressure sensing surface, which is pressed against the bottom of the inner cavity 8 through a sealing ring 10, and the pressure sensing surface is opposite to the pressure measuring port 9. The sealing ring 10 correspondingly surrounds the pressure measuring port 9. The fluid comes to the pressure sensing surface of the ceramic core through the pressure measuring port 9, enabling the ceramic core to measure the pressure of the fluid. The end cap 2 seals the top opening of the inner cavity 8, and the end cap 2 is correspondingly pressed on the crimping part 7 of the shielding cover 4. There is a riveting and bending part 18 on the housing 1, and the riveting and bending part 18 is correspondingly pressed on the end cap 2, thereby fixing the end cap 2 to the housing 1.

[0021] The existing metal shielding cover 4 is wrapped around the bottom of the ceramic core. Therefore, this metal shielding cover 4 needs to be riveted to form a flange, and then fixed to the end cap 2 through the flange. Due to the need for riveting, the production efficiency is relatively low. In the present invention, the shielding cover 4 is only composed of a surrounding ring part 6 and a crimping part 7, and is not wrapped around the bottom of the ceramic core. Therefore, the shielding cover 4 in the present invention does not need to be riveted and can be directly assembled on the ceramic core, simplifying the assembly process and improving the production efficiency.

[0022] An embodiment is as shown in the appendix Figure 2 As shown, the shielding cover 4 is composed of a single element, and the entire shielding cover 4 is an integral body. Since the housing 1 is made of metal, when the shielding cover 4 is an integral body, if the shielding cover 4 is made of metal, a layer of insulating paper needs to be provided between the shielding cover 4 and the housing 1 to prevent the metal shielding cover 4 from directly conducting with the metal housing 1. If the material of the shielding cover 4 is insulating plastic, the shielding cover 4 can be in direct contact with the housing 1.

[0023] An embodiment is as shown in the appendix Figure 3 As shown, the shielding cover 4 is formed by splicing two or more split blocks. Referring to the appendix Figure 5 As shown, the pressure sensor further includes a circuit board 5. There are two sub-boards 16 connected by a strip 17 on the circuit board 5, and the two sub-boards 16 are respectively welded to the ceramic core and the end cap 2. If the entire shielding cover 4 is an integral body, the shielding cover 4 must be installed on the ceramic core in advance before the ceramic core, the end cap 2, and the circuit board 5 are welded. However, corresponding welding fixtures are required during the welding process of the ceramic core, the end cap 2, and the circuit board 5. Therefore, installing the shielding cover 4 in advance will cause the original welding fixtures to no longer be applicable due to the interference of the shielding cover 4, resulting in the need to modify the welding fixtures and even the entire welding system, with a relatively high modification cost. In this embodiment, the shielding cover 4 is formed by splicing several split blocks. Therefore, as shown in the appendix Figure 6 As shown, the installation timing of the shielding cover 4 can be changed to after the ceramic core, the end cap 2, and the circuit board 5 are welded, eliminating the need to modify the welding system.

[0024] In the shielding cover 4, at least one of the patches is made of insulating plastic, and it is called the plastic patch 11. At least one of the patches is made of metal, and it is called the metal patch 12. The plastic patch 11 is interposed between the housing 1 and the metal patch 12. The metal patch 12 can enable the shielding cover 4 to obtain a better shielding effect, while the plastic patch 11 can prevent the metal patch 12 from directly contacting and conducting with the metal housing 1. If the shielding cover 4 is entirely composed of plastic patches 11, the shielding effect is weak; if the shielding cover 4 is entirely composed of metal patches 12, an additional layer of insulating paper is required between the shielding cover 4 and the housing 1, and adding the insulating paper will not only increase the material cost but also increase the process of installing the insulating paper, reducing the production efficiency.

[0025] After each patch is assembled into the shielding cover 4, the metal patches 12 are spliced into a metal shielding ring 13, and the metal shielding ring 13 correspondingly surrounds the outside of the pressure-sensitive element 3. As shown in the attached Figure 3 and 4 As shown, the metal shielding ring 13 also has a corresponding surrounding ring structure and a crimping structure. The surrounding ring structure surrounds the circumferential side of the pressure-sensitive element 3, and the crimping structure presses on the pressure-sensitive element 3. Specifically, the cross-section of the metal shielding ring 13 is an inverted L shape.

[0026] After each patch is assembled into the shielding cover 4, the plastic patches 11 are spliced into a plastic shielding ring 14. The pressure-sensitive element 3 is a ceramic core. The metal shielding ring 13 is located inside the shielding cover 4 and is in close contact with the outer contour surface of the ceramic core. The plastic shielding ring 14 is located outside the shielding cover 4 and is in close contact with the inner wall of the inner cavity 8. The plastic shielding ring 14 is also in close contact with the metal shielding ring 13. Thus, the shielding cover 4 also has the function of limiting the ceramic core, preventing the ceramic core from displacing in the housing 1 and making the stability of the ceramic core in the housing 1 better.

[0027] As shown in the attached Figure 3 and 4 As shown, the plastic patch 11 is arc-shaped, and after the plastic patches 11 are connected end to end, they are spliced into a plastic shielding ring 14. The metal patch 12 is arc-shaped, and after the metal patches 12 are connected end to end, they are spliced into a metal shielding ring 13. An annular card slot 15 is formed on the inner side of the plastic shielding ring 14. The cross-sectional shape of the annular card slot 15 is the same as the cross-sectional shape of the metal shielding ring 13, and the side of the annular card slot 15 facing the ceramic core is open. The metal shielding ring 13 is correspondingly embedded in the annular card slot 15, and the metal shielding ring 13 is in contact with the outer contour surface of the ceramic core through the notch of the annular card slot 15. As shown in the attached Figure 3 As shown, the metal shielding ring 13 can rotate in the annular card slot 15, so that the seams of the plastic patches 11 and the seams of the metal patches 12 are staggered from each other. After the seams are staggered from each other, the shielding cover 4 can form a stable assembled body and will not fall apart.

[0028] Based on the shielding cover 4 being formed by splicing a plurality of patches, the present invention further provides an assembly method of a pressure sensor with an inner shielding cover. The pressure sensor further includes a circuit board 5, and there are two sub-boards 16 connected by a strip 17 on the circuit board 5. As shown in the appendix Figure 5 As shown, after the two sub-boards 16 are respectively welded to the ceramic core and the end cap 2, each metal patch 12 is respectively inserted into the annular slot 15 of each plastic patch 11, and then the plastic patch 11 and the metal patch 12 are spliced around the strip 17. After the splicing is completed, the metal shielding ring 13 is rotated from the notch of the annular slot 15 to stagger the seams of the metal patches 12 and the seams of the plastic patches 11, so that the shielding cover 4 forms a stable splicing body to prevent the shielding cover 4 from falling apart; then a sealing ring 10 is installed on the housing 1, and the housing 1 is sleeved on the ceramic core, and then the housing 1 is riveted, so that a riveted bending part 18 is formed on the housing 1, and the riveted bending part 18 is correspondingly pressed on the end cap 2.

[0029] The above is only the preferred embodiment of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and retouches can be made, and these improvements and retouches should also be regarded as the protection scope of the present invention.

Claims

1. A pressure sensor with an internal shielding cover, characterized in that: The pressure sensor includes a housing (1) and an end cover (2); there is a pressure sensing element (3) in the inner cavity (8) of the housing (1), and a shielding cover (4) is provided outside the pressure sensing element (3); the shielding cover (4) includes a surrounding ring part (6) and a crimping part (7), the surrounding ring part (6) is correspondingly surrounded and attached to the peripheral side of the pressure sensing element (3), and the crimping part (7) is correspondingly pressed and attached to the top edge of the pressure sensing element (3); The top of the inner cavity (8) is an opening, and there is a pressure measuring port (9) at the bottom of the inner cavity (8); the bottom of the pressure sensing element (3) has a pressure sensing surface, and the pressure sensing surface is pressed against the bottom of the inner cavity (8) through a sealing ring (10), and the pressure sensing surface is opposite to the pressure measuring port (9); the end cover (2) seals the top opening of the inner cavity (8), and the end cover (2) is correspondingly pressed on the crimping part (7) of the shielding cover (4); The shielding cover (4) is formed by splicing a plurality of pieces, at least one piece is made of insulating plastic and is called a plastic piece (11); at least one piece is made of metal and is called a metal piece (12); the plastic piece (11) is separated between the housing (1) and the metal piece (12); Both the metal piece (12) and the plastic piece (11) are arc-shaped; after each piece is spliced into the shielding cover (4), the metal pieces (12) among them are connected end to end to form a metal shielding ring (13); the metal shielding ring (13) is correspondingly surrounded outside the pressure sensing element (3); the plastic pieces (11) among them are connected end to end to form a plastic shielding ring (14); the pressure sensing element (3) is a ceramic core body, the metal shielding ring (13) is located inside the shielding cover (4), and the metal shielding ring (13) is tightly attached to the outer contour surface of the ceramic core body; the plastic shielding ring (14) is located outside the shielding cover (4), and the plastic shielding ring (14) is tightly attached to the inner wall of the inner cavity (8); An annular card slot (15) is formed on the inner side of the plastic shielding ring (14), the metal shielding ring (13) is embedded in the annular card slot (15), and the metal shielding ring (13) is attached to the outer contour surface of the ceramic core body through the notch of the annular card slot (15); and the metal shielding ring (13) can rotate in the annular card slot (15) so that the seams of the plastic pieces (11) are staggered from the seams of the metal pieces (12).

2. The assembling method of the pressure sensor with an inner shield according to claim 1, characterized in that: The pressure sensor further includes a circuit board (5). There are two sub-boards (16) connected by a board strip (17) on the circuit board (5). After the two sub-boards (16) are respectively welded to the ceramic core body and the end cap (2), each metal block (12) is respectively inserted into the annular slot (15) of each plastic block (11). Then, the plastic blocks (11) and the metal blocks (12) are spliced around the board strip (17). After the splicing is completed, the metal shielding ring (13) is rotated to stagger the seams of the metal blocks (12) from the seams of the plastic blocks (11) to prevent the shielding cover (4) from falling apart. Then, an O-ring (10) is installed on the housing (1), the housing (1) is sleeved outside the ceramic core body, and the housing (1) is riveted so that a riveted bending portion (18) is formed on the housing (1), and the riveted bending portion (18) is correspondingly pressed on the end cap (2).

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