Diesel engine pressure sensor

Abstract

The utility model relates to the technical field of mechanical pressure-sensitive elements, in particular to a diesel engine pressure sensor, which comprises a PCB (printed circuit board) shell and an external adapter, the external adapter is mounted at the lower end of the PCB shell, a connecting part is in threaded connection in the PCB shell, an annular boss is formed between the connecting part and the external adapter, and the annular boss is in threaded connection with the PCB shell. The PCB shell is provided with an annular boss, the diameter of the annular boss is larger than that of the connecting part, the annular boss is further sleeved with a first O-shaped ring, the first O-shaped ring is arranged between the PCB shell and the annular boss, the periphery of the connecting part is provided with an annular groove capable of containing the first O-shaped ring, the annular groove is connected with the annular boss, and an adjusting piece capable of pushing the first O-shaped ring to move longitudinally is arranged in the annular boss. According to the diesel engine pressure sensor, the adjusting piece is arranged on the external adapter, and after the external adapter and the PCB shell are in threaded connection, the adjusting piece is used for pushing and abutting against the first O-shaped ring for sealing, so that deformation or abrasion of the sealing ring is reduced, and the sealing performance is guaranteed.

Description

Technical Field

[0001] The utility model relates to the technical field of mechanical pressure-sensitive elements, and particularly relates to a diesel engine pressure sensor. Background Art

[0002] Diesel engine pressure sensors play a key role in the automotive industry and are used to monitor and regulate the pressure conditions of diesel engines. However, existing diesel engine pressure sensors face some technical challenges when it comes to requirements for sealing performance and waterproof effects.

[0003] The housing of traditional diesel engine pressure sensors usually consists of multiple parts. O-rings or similar sealing elements are used between multiple parts to ensure sealing performance. However, when installing an O-ring between two components connected by threads, the rotating component will exert a rotational thrust on the O-ring, which will not only cause significant deformation of the O-ring but also easily wear the O-ring, thereby affecting its sealing effect. Summary of the Utility Model

[0004] To solve the problem that existing components will cause extrusion deformation to the O-ring during the process of rotary screw connection, thereby affecting the sealing effect, the utility model provides a diesel engine pressure sensor. By providing an adjusting member on the external conversion head, after the external conversion head and the PCB housing are screwed together, the first O-ring is pushed and abutted by the adjusting member for sealing, reducing the deformation or wear caused to the sealing ring and ensuring the sealing performance.

[0005] The utility model provides a diesel engine pressure sensor, which includes a PCB housing and an external conversion head. The PCB housing is a hollow structure that penetrates up and down. An external conversion head is installed at the lower end of the PCB housing. The external conversion head has a connecting portion extending into the hollow structure of the PCB housing. The connecting portion is threadedly connected inside the PCB housing. An annular boss is formed between the connecting portion and the external conversion head. The diameter of the annular boss is larger than that of the connecting portion. A first O-ring is also sleeved on the annular boss. The first O-ring is placed between the PCB housing and the annular boss. An annular groove for accommodating the first O-ring is formed on the periphery of the connecting portion. The annular groove is connected to the annular boss. An adjusting member for pushing the first O-ring to move longitudinally is arranged inside the annular boss. The PCB housing and the external conversion head are connected by a threaded method. After the screwing is completed, the first O-ring is pushed upward into the joint surface by the adjusting member for sealing, avoiding extrusion of the O-ring during the rotary screw connection process and ensuring the sealing performance.

[0006] Further, the adjusting member includes an annular pressing block and a screw rod. The screw rod is threadedly connected to the annular boss. An annular pressing block that can abut against the first O-ring is arranged at the top end of the screw rod. The annular pressing block is driven to move longitudinally by the screw rod screwed on the annular boss.

[0007] Further, a copper washer is sleeved on the annular boss, and the copper washer is placed between the first O-ring and the annular pressing block. The first O-ring is pressed tightly to further improve the sealing performance.

[0008] Further, a step groove is formed on the outer side wall of the annular pressing block, the copper washer is clamped around the step groove, an arc groove is formed along the inner side wall of the copper washer, and the first O-ring is placed between the arc groove and the annular groove. The copper washer and the first O-ring are pushed upward together by the annular pressing block, and the sealing performance is good.

[0009] Further, a ceramic capacitance sensor core is arranged in the external adapter, a signal conditioning board is arranged above the ceramic capacitance sensor core, and the ceramic capacitance sensor core and the signal conditioning board are arranged in the external adapter through a fastening nut. The ceramic capacitance sensor core is used to replace the diffused silicon piezoresistive core, improving the performance of the sensor.

[0010] Further, a plastic pressing ring and a power supply filter board arranged above the plastic pressing ring are arranged in the PCB housing, and the power supply filter board and the plastic pressing ring are arranged in the PCB housing through a metal pressing ring. The power supply filter board is fixed by the metal pressing ring.

[0011] Further, it further includes an outlet housing, a stuffing box is connected to the side of the outlet housing, the outlet housing is fixedly connected to the PCB housing through a fixing bolt, a cover is further arranged above the outlet housing, and the cover is fixedly connected to the outlet housing and the PCB housing through a screw body adapted to the fixing bolt. Through the cooperation of the fixing bolt and the screw body, the outlet housing, the PCB housing and the cover are fixed into a whole.

[0012] Further, the screw body has a cap head, an embedding hole for accommodating the cap head is formed on the cover, and a waterproof gasket is arranged between the cap head and the embedding hole. The sealing performance of the connection part is improved through the waterproof gasket.

[0013] Further, a second O-ring is arranged on the connection surface between the cover and the outlet housing, a third O-ring is arranged between the outlet housing and the PCB housing, and a fourth O-ring is arranged below the ceramic capacitance sensor core in the external adapter. The waterproof and sealing effect is good.

[0014] The beneficial effects of the present utility model are as follows:

[0015] The present utility model provides a diesel engine pressure sensor. By providing an adjusting member that can push the sealing ring, after the connection part of the external adapter is screwed to the PCB housing, the sealing ring between the external adapter and the PCB housing is pushed upward to the connection surface gap for sealing by using the adjusting member, avoiding the extrusion deformation of the sealing ring during the rotary screwing process, and having a good sealing effect. Description of the Drawings

[0016] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0017] Figure 1 is a schematic structural diagram of a diesel engine pressure sensor;

[0018] Figure 2 is Figure 1 an enlarged view of part A in

[0019] In the figure, 1. cover, 2. wire outlet housing, 3. PCB housing, 4. copper washer, 5. external adapter, 6. screw body, 7. waterproof gasket, 8. first O-ring, 9. fixing bolt, 10. metal pressing ring, 11. second O-ring, 12. plastic pressing ring, 13. fastening nut, 14. third O-ring, 15. annular boss, 16. fourth O-ring, 17. stuffing box, 18. power supply filter board, 19. signal conditioning board, 20. ceramic capacitive sensor core, 21. stepped groove, 22. annular groove, 23. annular pressing block, 24. screw rod, 25. arc groove. Specific Embodiments

[0020] The following will clearly and completely describe the technical solutions of the present invention in conjunction with the drawings. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention.

[0021] Currently, the diesel engine pressure sensor includes a PCB housing 3 and an external adapter 5. The PCB housing 3 is a hollow structure that penetrates up and down. The external adapter 5 is installed at the lower end of the PCB housing 3. The external adapter 5 has a connecting portion that extends into the hollow structure of the PCB housing 3, and the connecting portion is threadedly connected inside the PCB housing 3. In order to ensure the sealing between the PCB housing 3 and the external adapter 5, an annular boss 15 is formed between the connecting portion and the external adapter 5. The diameter of the annular boss 15 is larger than the diameter of the connecting portion. A first O-ring 8 is also sleeved on the annular boss 15, and the first O-ring 8 is placed between the PCB housing 3 and the annular boss 15.

[0022] In order to prevent the first O-ring 8 from being squeezed and deformed during the process of rotatably screwing the PCB housing 3 and the external adapter 5, thereby affecting the sealing effect, a diesel engine pressure sensor is designed. As Figure 1 shown, an annular groove 22 for accommodating the first O-ring 8 is formed around the connecting portion. The annular groove 22 is connected to the annular boss 15, and an adjusting member for pushing the first O-ring 8 to longitudinally displace is provided inside the annular boss 15.

[0023] Specifically, the adjusting member includes an annular pressing block 23 and a screw rod 24. The screw rod 24 is threadedly connected to the annular boss 15, and an annular pressing block 23 that can abut against the first O-ring 8 is provided at the top end of the screw rod 24. By rotating the screw rod 24, the position of the annular pressing block 23 can be adjusted, and after the adjustment is completed, the position of the annular pressing block 23 can be automatically locked.

[0024] A copper washer 4 is also sleeved on the annular boss 15. The copper washer 4 is placed between the first O-ring 8 and the annular pressing block 23. Through the copper washer 4, the gap between the external adapter 5 and the PCB housing 3 can be filled, improving the sealing performance of the pressure sensor and enhancing its waterproof effect.

[0025] A stepped groove 21 is formed on the outer side wall of the annular pressing block 23. The copper washer 4 is clamped around the stepped groove 21. An arc-shaped groove 25 is formed along the inner side wall of the copper washer 4. The first O-ring 8 is placed between the arc-shaped groove 25 and the annular groove 22. This enables both the annular pressing block 23 and the arc-shaped groove 25 to contact the first O-ring 8, increasing the area of the first O-ring 8 being squeezed and allowing it to better fill the gap between the PCB housing 3 and the external adapter 5 when being squeezed. The arc-shaped groove 25 is arranged in imitation of the first O-ring 8. The first O-ring 8 can be squeezed by the copper washer 4 and pushed to the position of the gap between the PCB housing 3 and the connecting part, thereby further improving its sealing performance.

[0026] During use, first threadedly connect the connecting part of the external adapter 5 and the PCB housing 3, and then drive the annular pressing block 23 to move towards the PCB housing 3 through the adjusting member, so that the annular pressing block 23 squeezes the copper washer 4 and the first O-ring 8. Then, the gap between the PCB housing 3 and the external adapter 5 can be filled through the first O-ring 8 to ensure the sealing effect. Since the annular pressing block 23 only linearly pushes the first O-ring 8 when moving and does not perform rotational pushing, it can effectively reduce the deformation amplitude of the first O-ring 8 and the wear between the first O-ring 8 and the PCB housing 3 and the external adapter 5, ensuring the sealing performance of the first O-ring 8. Then, install the third O-ring 14 on the outer side of the upper end of the PCB housing 3, install the wire outlet housing 2 on the upper end of the PCB housing 3, install the second O-ring 11 on the upper end of the wire outlet housing 2, install the cover 1 on the upper end of the wire outlet housing 2, and then limit the cover 1 and the wire outlet housing 2 through the screw body 6.

[0027] A ceramic capacitive sensor core 20 is arranged inside the external adapter 5. A signal conditioning board 19 is provided above the ceramic capacitive sensor core 20. The ceramic capacitive sensor core 20 and the signal conditioning board 19 are arranged inside the external adapter 5 through a fastening nut 13. The signal conditioning board 19 can be limited through the fastening nut 13 screwed inside the external adapter 5.

[0028] The ceramic capacitive sensor core 20 is adopted to replace the traditional diffused silicon piezoresistive core. While ensuring the same interface size, the performance of the sensor is improved. The ceramic capacitive sensor core 20 has excellent characteristics such as strong corrosion resistance, impact resistance, and high elasticity. At the same time, the extremely high thermal stability of the ceramic enables its operating temperature range to be -40°C to 135°C. During the operation of the ceramic capacitive sensor core 20, there is no need to transmit pressure through other media. The monitored pressure acts directly on the ceramic diaphragm, and the change in capacitance between the base electrode and the diaphragm electrode is proportional to the pressure. When overloaded, the diaphragm abuts against the base without being damaged, and when the pressure is restored, its performance will not be affected at all, completely solving the shortcoming of low-range overload failure.

[0029] A plastic compression ring 12 and a power supply filter board 18 placed above the plastic compression ring 12 are arranged in the PCB housing 3. The power supply filter board 18 and the plastic compression ring 12 are arranged in the PCB housing 3 through a metal compression ring 10.

[0030] It also includes an outlet housing 2. A stuffing box 17 is connected to the side of the outlet housing 2. The outlet housing 2 is fixedly connected to the PCB housing 3 through a fixing bolt 9. A cover 1 is also provided above the outlet housing 2. The cover 1 is fixedly connected to the outlet housing 2 and the PCB housing 3 through a screw body 6 adapted to the fixing bolt 9. Through the cooperation of the fixing bolt 9 and the screw body 6, the cover 1, the outlet housing 2, the PCB housing 3, the copper washer 4, and the stuffing box 17 are connected to form an integral whole, and the installation and disassembly are convenient and fast.

[0031] The screw body 6 has a cap head. An embedding hole for accommodating the cap head is provided on the cover 1. A waterproof gasket 7 is provided between the cap head and the embedding hole. By providing the waterproof gasket 7, the sealing performance between the screw body 6 and the cover 1 can be improved, and further its waterproof performance can be enhanced.

[0032] In order to ensure the sealing performance of the housing, a second O-ring 11 is provided on the connection surface between the cover 1 and the outlet housing 2, and a third O-ring 14 is provided between the outlet housing 2 and the PCB housing 3. The gap between the cover 1 and the outlet housing 2 can be filled through the second O-ring 11, and the gap between the outlet housing 2 and the PCB housing 3 can be filled through the third O-ring 14, thereby enhancing the sealing performance of the housing.

[0033] In order to protect the ceramic capacitive sensor core 20, a fourth O-ring 16 is provided inside the external adapter 5 and below the ceramic capacitive sensor core 20.

[0034] By setting the cooperation of the first O-ring 8, the second O-ring 11 and the third O-ring 14 with the threaded connection between the PCB housing 3 and the external adapter 5, the diesel engine pressure sensor can have better sealing performance and waterproof effect. When installing the external adapter 5 and the first O-ring 8, the installation method of first installing the external adapter 5 and then squeezing the first O-ring 8 can effectively reduce the deformation amplitude of the first O-ring 8 and the wear between the first O-ring 8, the PCB housing 3 and the external adapter 5, ensure the sealing performance of the first O-ring 8, and reduce the phenomenon that the waterproof effect and sealing performance of the diesel engine pressure sensor decrease due to large deformation or large wear of the first O-ring 8 during installation.

[0035] The above description is illustrative rather than restrictive to the present utility model. Those of ordinary skill in the art understand that without departing from the spirit and scope defined by the appended claims, many modifications, variations or equivalents can be made, but all will fall within the protection scope of the present utility model.

Claims

1. A diesel engine pressure sensor, comprising a PCB housing (3) and an external conversion head (5), wherein the PCB housing (3) is a hollow structure extending vertically through the PCB housing, the external conversion head (5) is mounted at the lower end of the PCB housing (3), the external conversion head (5) having a connecting portion extending into the hollow structure of the PCB housing (3), the connecting portion being threadedly connected in the PCB housing (3), An annular boss (15) is formed between the connecting portion and the external conversion head (5); the diameter of the annular boss (15) is greater than the diameter of the connecting portion; a first O-ring (8) is sleeved on the annular boss (15); the first O-ring (8) is placed between the PCB housing (3) and the annular boss (15); Features: An annular groove (22) capable of accommodating a first O-ring (8) is provided on the periphery of the connecting portion, the annular groove (22) being connected to the annular boss (15), and an adjusting member capable of pushing the first O-ring (8) to move longitudinally is provided inside the annular boss (15).

2. A diesel engine pressure sensor according to claim 1, characterized in that: The adjusting member comprises an annular pressing block (23) and a screw rod (24); the screw rod (24) is threadedly connected to the annular boss (15); and the top end of the screw rod (24) is provided with an annular pressing block (23) capable of abutting against the first O-ring (8).

3. A diesel engine pressure sensor according to claim 2, characterized in that: A copper washer (4) is also sleeved on the annular boss (15), and the copper washer (4) is placed between the first O-ring (8) and the annular pressing block (23).

4. A diesel engine pressure sensor according to claim 3, characterized in that: The outer wall of the annular pressing block (23) is provided with a step groove (21), and the copper washer (4) is clamped on the outer periphery of the step groove (21). An arc-shaped groove (25) is provided on the upper edge of the inner side wall of the copper gasket (4), and the first O-ring (8) is placed between the arc-shaped groove (25) and the annular groove (22).

5. A diesel engine pressure sensor according to claim 1, characterized in that: A ceramic capacitor sensor core (20) is arranged in the external conversion head (5), a signal conditioning board (19) is arranged above the ceramic capacitor sensor core (20), and the ceramic capacitor sensor core (20) and the signal conditioning board (19) are arranged in the external conversion head (5) via a fastening nut (13).

6. A diesel engine pressure sensor according to claim 1, characterized in that: A plastic pressure ring (12) and a power filter board (18) placed above the plastic pressure ring (12) are arranged in the PCB housing (3); the power filter board (18) and the plastic pressure ring (12) are arranged in the PCB housing (3) via a metal pressure ring (10).

7. A diesel engine pressure sensor according to claim 1, characterized in that: It also comprises an outlet casing (2), a stuffing box (17) being connected to the side of the outlet casing (2), the outlet casing (2) being fixedly connected to the PCB casing (3) via a fixing bolt (9), a cover (1) being provided above the outlet casing (2), the cover (1) being fixedly connected to the outlet casing (2) and the PCB casing (3) via a screw body (6) matching the fixing bolt (9).

8. A diesel engine pressure sensor according to claim 7, characterized in that: The screw body (6) has a cap head, the cover (1) is provided with an embedding hole capable of accommodating the cap head, and a waterproof gasket (7) is provided between the cap head and the embedding hole.

9. A diesel engine pressure sensor according to claim 7, characterized in that: A second O-ring (11) is provided on the connection surface between the cover (1) and the outlet housing (2), and a third O-ring (14) is provided between the outlet housing (2) and the PCB housing (3).

10. A diesel engine pressure sensor according to claim 5, characterized in that: A fourth O-ring (16) is provided inside the external conversion head (5) and below the ceramic capacitance sensor core (20).

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