Miniaturized high-sealing gearbox pressure sensor

Abstract

The utility model belongs to the technical field of sensors, and particularly relates to a miniaturized high-sealing gearbox pressure sensor, which comprises an elastic base, a strain gauge, a shell and a connecting element, the shell comprises an upper shell and a lower shell, the lower shell and the upper shell are clamped and fixed, and a first sealing part and a second sealing part are arranged at the connecting part of the lower shell and the upper shell; one end of the connecting element is connected with the circuit board, and the other end of the connecting element extends out of the shell; according to the utility model, the bottom of the housing is plugged by welding and fixing the lower housing and the elastic base, the top of the housing is plugged by the third sealing part between the connecting element and the housing, and the upper housing and the lower housing are sealed and fixed by the second sealing part and the third sealing part; the first sealing part, the second sealing part and the third sealing part form a triple sealing protection system, so that the upper shell, the lower shell and the elastic base are enclosed to form a sealing cavity, and the sealing requirement of the gearbox sensor in an oil immersion environment for a long time is met.

Description

Technical Field

[0001] This utility model belongs to the field of sensor technology, specifically relating to a miniaturized, highly sealed gearbox pressure sensor. Background Technology

[0002] As automotive transmission systems rapidly evolve towards greater integration and intelligence, transmission pressure sensors, as key sensing components in hydraulic control systems, directly impact shift smoothness, clutch control precision, and system reliability. While current mainstream pressure sensors can meet basic pressure monitoring needs, they still have significant shortcomings when facing the increasingly stringent technical requirements of modern transmissions.

[0003] Traditional pressure sensors typically employ multi-layered stacking or split architectures, resulting in a large overall size that struggles to meet the compact installation space requirements of next-generation transmissions. This structural complexity not only increases manufacturing costs but also introduces more potential failure points, such as leakage risks due to increased sealing interfaces and fatigue fracture at weld points. In terms of performance parameters, existing sensor solutions often struggle to simultaneously meet various key performance indicators. Simplified designs adopted in pursuit of miniaturization typically sacrifice measurement accuracy or temperature stability. From an application perspective, the widespread adoption of new technologies such as 48V mild hybrid systems and multi-gear transmissions places more stringent demands on pressure sensors. On the one hand, they need to further reduce their size to fit into more compact installation spaces; on the other hand, they must maintain high measurement accuracy over a wide temperature range while possessing excellent vibration resistance, shock resistance, and sealing performance. Ensuring stable performance while simplifying the structure has become a key technological challenge. Utility Model Content

[0004] The technical problem to be solved by this utility model is: in order to solve the problem that the overall size of the transmission pressure sensor in the prior art is too large, which cannot meet the installation space requirements of the compact transmission, and the poor sealing performance cannot meet the requirements of its long-term oil immersion environment, a miniaturized high-sealing transmission pressure sensor and its pressure sensor are provided.

[0005] To solve the above-mentioned technical problems, this utility model adopts the following technical solution: a miniaturized, high-sealing gearbox pressure sensor, comprising:

[0006] The elastic base has internal channels for fluid to enter;

[0007] Strain gauges are attached to the elastic base;

[0008] The outer shell includes an upper shell and a lower shell connected between the upper shell and the elastic base. The lower shell is snapped and fixed to the upper shell, and the outer wall surface of the connection between the two is provided with a first sealing part, and the inner wall surface is provided with a second sealing part. The lower shell and the elastic base are welded and fixed together.

[0009] A circuit board, which is electrically connected to the strain gauge;

[0010] And connecting elements, one end of which is connected to the circuit board, and the other end extends out of the housing and is provided with a third sealing part between it and the housing.

[0011] Furthermore, the connecting element includes a terminal and a spring connecting the terminal and the circuit board, the terminal being elongated.

[0012] Furthermore, the lower housing is bent inward at one end near the upper housing to form a snap-fit ​​portion, and the upper housing is recessed to form a snap-fit ​​groove for the snap-fit ​​portion to snap into. The first sealing portion, the second sealing portion, and the third sealing portion are all adhesive seals.

[0013] Furthermore, the sensor also includes a frame, the frame having a lower mounting cavity, and the upper housing having an upper mounting cavity. The lower mounting cavity and the upper mounting cavity together form a spring mounting cavity for mounting the spring and confining it within the cavity.

[0014] Furthermore, the sensor also includes a support ring for supporting the circuit board to separate it from the elastic base.

[0015] Furthermore, one end of the support ring near the circuit board is bent to form a support portion, and the other end is bent to form a fixing portion that is welded and fixed to the elastic base.

[0016] Furthermore, the flow channel extends axially along the elastic base and has an open end through one end face, while the other end is a closed end, and the strain gauge is attached to the closed end.

[0017] Furthermore, the outer peripheral wall of the elastic base is recessed to form a blocking portion for blocking installation stress from the mounting surface.

[0018] Furthermore, the spring and the terminal are both of several and are circumferentially spaced, and each terminal has a bent portion for connecting with the spring by bending the end of the terminal close to its corresponding spring away from the other terminals.

[0019] Furthermore, the frame and the outer shell are interference-fitted, and the outer peripheral wall of the frame and the inner peripheral wall of the outer shell respectively have protruding positioning parts and recessed positioning grooves for the positioning parts to be engaged.

[0020] The beneficial effects of this utility model are as follows: This utility model uses welding and fixing between the lower housing and the elastic base to seal the bottom of the outer shell, and the third sealing part between the connecting element and the outer shell to seal the top of the outer shell. At the same time, the second sealing part and the third sealing part seal and fix the upper housing and the lower housing. The first sealing part, the second sealing part and the third sealing part form a triple sealing protection system, so that the upper housing, the lower housing and the elastic base form a sealed cavity to seal the circuit board, connecting wires, etc. in the sealed cavity, which meets the sealing requirements of the gearbox sensor that is in an oil immersion environment for a long time. In addition, this application uses the cooperation of the elastic base and the strain gauge to simplify the structure while improving the sealing performance and realizing the miniaturization of the sensor. Attached Figure Description

[0021] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0022] Figure 1 This is the outline drawing of this utility model;

[0023] Figure 2 This is a cross-sectional view of the present invention;

[0024] Figure 3 This is a schematic diagram of the structure in which the connecting element mates with the frame;

[0025] Figure 4 This is a schematic diagram of the lower shell structure;

[0026] Figure 5 This is a first-view structural schematic diagram of the upper shell;

[0027] Figure 6 This is a structural schematic diagram of the upper shell from a second perspective;

[0028] Figure 7 This is a schematic diagram of the structure of the elastic base;

[0029] In the picture:

[0030] 1. Elastic base; 101. Flow channel; 102. Open end; 103. Closed end; 104. Blocking part; 105. First stepped surface; 106. Second stepped surface; 107. Threaded part;

[0031] 2. Strain gauge;

[0032] 3. Upper housing; 301. Snap-fit ​​groove; 302. Upper mounting cavity;

[0033] 4. Lower housing; 401. Snap-fit ​​part; 402. Connecting part; 403. Positioning groove;

[0034] 5. First sealing part;

[0035] 6. Second sealing part;

[0036] 7. Circuit board;

[0037] 8. Third sealing part;

[0038] 9. Terminal; 901. Bending section; 902. Main body section;

[0039] 10. Spring;

[0040] 11. Frame; 1101. Lower mounting cavity; 1102. Positioning part;

[0041] 12. Support ring; 1201. Support part; 1202. Fixing part;

[0042] 13. Protective adhesive. Detailed Implementation

[0043] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, illustrating only the basic structure of the present invention, and therefore only show the components relevant to the present invention.

[0044] like Figures 1-7 As shown, this utility model is a miniaturized, high-sealing gearbox pressure sensor, comprising:

[0045] The elastic base 1 has a flow channel 101 inside for fluid to enter. After the fluid enters the flow channel 101, it exerts pressure on the elastic base 1, causing the elastic base 1 to undergo slight deformation.

[0046] Strain gauge 2 is attached to the elastic base 1. The strain gauge 2 is directly bonded to the surface of the elastic base 1 using MSG glass micro-fusion technology. When the elastic base 1 deforms, the resistance of the strain gauge 2 changes. This eliminates the need for the sealing diaphragm structure of traditional pressure sensors, simplifying the structure while improving the sealing performance.

[0047] The outer shell includes an upper shell 3 and a lower shell 4 connected between the upper shell 3 and the elastic base 1. A portion of the elastic base 1 is located inside the lower shell 4. The lower shell 4 and the elastic base 1 are welded and fixed to seal the bottom of the outer shell. The outer peripheral wall of the elastic base 1 protrudes to form a first stepped surface 105. The bottom of the lower shell 4 is bent to form a connecting part 402 that is welded and fixed to the first stepped surface 105. The lower shell 4 and the upper shell 3 are snapped and fixed together, and the outer wall surface of the connection part is provided with a first sealing part 5 and the inner wall surface is provided with a second sealing part 6. The first sealing part 5 and the second sealing part 6 seal and fix the upper shell 3 and the lower shell 4.

[0048] The circuit board 7 is electrically connected to the strain gauge 2 via a connecting wire, which can be, but is not limited to, aluminum wire, etc. The connection part between the connecting wire and the strain gauge 2 and the circuit board 7 is provided with protective adhesive 13, which can prevent the connection from loosening, thereby improving the connection strength.

[0049] And a connecting element, one end of which is connected to the circuit board 7, and the other end extends out of the housing and is provided with a third sealing part 8 between it and the housing, the third sealing part 8 sealing the top of the housing;

[0050] In this application, the lower housing 4 is welded and fixed to the elastic base 1 to seal the bottom of the outer shell. The third sealing part 8 between the connecting element and the outer shell seals the top of the outer shell. At the same time, the second sealing part 6 and the third sealing part 8 seal and fix the upper housing 3 and the lower housing 4. The first sealing part 5, the second sealing part 6 and the third sealing part 8 form a triple sealing protection system, so that the upper housing 3, the lower housing 4 and the elastic base 1 enclose a sealed cavity to seal the circuit board 7, connecting wires, etc. in the sealed cavity, which meets the sealing requirements of the gearbox sensor that is in an oil immersion environment for a long time. In addition, this application uses the cooperation between the elastic base 1 and the strain gauge 2 to simplify the structure while improving the sealing performance and realize the miniaturization of the sensor.

[0051] In some examples, the connecting element includes a terminal 9 and a spring 10 connected between the terminal 9 and the circuit board 7. The terminal 9 is elongated and has a more regular structure, making it easier to achieve a seal compared to the spring 10.

[0052] In some examples, the lower housing 4 is bent inward at one end near the upper housing 3 to form a snap-fit ​​portion 401, and the upper housing 3 is recessed to form a snap-fit ​​groove 301 into which the snap-fit ​​portion 401 is snapped. Both the snap-fit ​​portion 401 and the snap-fit ​​groove 301 are annular structures, and the first sealing portion 5, the second sealing portion 6 and the third sealing portion 8 are all adhesive seals.

[0053] In some examples, the sensor further includes a frame 11 having a lower mounting cavity 1101 and an upper housing 3 having an upper mounting cavity 302. The lower mounting cavity 1101 and the upper mounting cavity 302 together form a spring mounting cavity for mounting and confining the spring 10 inside. The top of the upper mounting cavity 302 contracts to form an upper limit portion, and the bottom of the lower mounting cavity 1101 contracts to form a lower limit portion. The upper limit portion and the lower limit portion confine the spring 10 within the spring mounting cavity and provide a connection port for connecting the spring 10 to an external system.

[0054] In some examples, the sensor also includes a support ring 12 for supporting the circuit board 7 to separate it from the elastic base 1, such that the circuit board 7 and the elastic base 1 are distributed vertically at intervals to reduce the impact of fluid on the circuit board 7. By physically isolating the high-frequency vibration sensing unit from the analog signal processing circuit, and eliminating the interference of the gearbox PWM signal on pressure detection through digital filtering algorithms, the signal-to-noise ratio is improved to over 80dB, thereby improving the detection accuracy.

[0055] In some examples, the support ring 12 is bent at one end near the circuit board 7 to form a support portion 1201 with a notch to facilitate bending, and the other end is bent to form a fixing portion 1202 that is welded and fixed to the elastic base 1. The outer peripheral wall of the elastic base 1 protrudes to form a second stepped surface 106 that cooperates with the fixing portion 1202.

[0056] In some examples, the flow channel 101 extends axially along the elastic base 1 and forms an open end 102 through one end face, while the other end is a closed end 103. The strain gauge 2 is attached to the closed end 103, which is a thin-walled structure. When fluid enters the flow channel 101 and exerts pressure on the elastic base 1, the thin-walled structure is more likely to deform so that it can be sensed by the strain gauge 2.

[0057] In some examples, the outer peripheral wall of the elastic base 1 is recessed to form a blocking portion 104 for blocking installation stress from the mounting surface. The blocking portion 104 is an annular groove. Installation stress is generated when the outer shell mates with the first stepped surface 105 and when the support ring 12 mates with the second stepped surface 106. The blocking portion 104 can block most of the installation stress, thereby significantly reducing the installation stress reaching the closed end 103 and improving the accuracy of the sensor.

[0058] In some examples, the springs 10 and terminals 9 are multiple and circumferentially spaced, and each terminal 9 includes a main body 902. The end of the main body 902 near its corresponding spring 10 is bent away from the other terminals 9 to form a bent portion 901 for connection with the spring 10. The housing has an opening for the main body 902 to extend out. During installation, the main body 902 extends upward through the opening, and the bent portion 901 is located inside the housing, thereby limiting the degree of freedom of the terminal 9 to move upward. Furthermore, the bent portion 901 bends outward from the bottom end of the main body 902. Therefore, the multiple main bodies 902 are closer together than the bent portion 901, and the multiple openings for the multiple main bodies 902 to extend out are also closer together, which is more conducive to the implementation of the third sealing part 8, and reduces the sealing area and improves the sealing performance.

[0059] In some examples, the frame 11 is interference-fitted with the outer shell, and the outer peripheral wall of the frame 11 and the inner peripheral wall of the outer shell respectively have a protruding positioning part 1102 and a recessed positioning groove 403 for the positioning part 1102 to be engaged. The positioning part 1102 and the positioning groove 403 cooperate to position the frame 11, thereby positioning the lower mounting cavity 1101 formed inside it. In this embodiment, the positioning part 1102 is located on the frame 11, and the positioning groove 403 is located on the lower shell 4 and the positioning groove 403 penetrates one end face of the lower shell 4 axially for the positioning part 1102 to be engaged.

[0060] Working principle:

[0061] During testing, the sensor is directly connected to the transmission oil circuit through the threaded part 107 at the lower end, and communicates with the transmission control unit (TCU) at the upper end through a connecting element. Fluid (oil) enters the flow channel 101 from the open end 102 and generates pressure on the elastic base 1. The elastic base 1 deforms, and the resistance value of the strain gauge 2 attached to the closed end 103 of the elastic base 1 changes. The signal is conditioned by the circuit board 7 and then led out through the spring 10 and the terminal 9 to detect the change in transmission pressure, thus completing high-precision pressure monitoring.

[0062] In this application, the lower housing 4 is welded and fixed to the elastic base 1 to seal the bottom of the outer shell. The third sealing part 8 between the connecting element and the outer shell seals the top of the outer shell. At the same time, the second sealing part 6 and the third sealing part 8 seal and fix the upper housing 3 and the lower housing 4. The first sealing part 5, the second sealing part 6 and the third sealing part 8 form a triple sealing protection system, so that the upper housing 3, the lower housing 4 and the elastic base 1 form a sealed cavity to seal the circuit board 7, connecting wires, etc. in the sealed cavity, which meets the sealing reliability of the gearbox sensor that is in an oil immersion environment for a long time. In addition, this application uses the cooperation of the elastic base 1 and the strain gauge 2 to simplify the structure while improving the sealing performance and realize the miniaturization of the sensor.

[0063] Based on the above-described preferred embodiments of this utility model, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the technical concept of this utility model. The technical scope of this utility model is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A miniaturized, highly sealed gearbox pressure sensor, characterized in that: include: The elastic base (1) has a flow channel (101) inside for fluid to enter. Strain gauge (2), which is attached to the elastic base (1); The outer shell includes an upper shell (3) and a lower shell (4) connected between the upper shell (3) and the elastic base (1). The lower shell (4) is snapped and fixed to the upper shell (3), and the outer wall surface of the connection between the two is provided with a first sealing part (5) and the inner wall surface is provided with a second sealing part (6). The lower shell (4) and the elastic base (1) are welded and fixed together. Circuit board (7), which is electrically connected to the strain gauge (2); The connecting element has one end connected to the circuit board (7) and the other end extends out of the housing and is provided with a third sealing part (8) between it and the housing.

2. The miniaturized, high-sealing gearbox pressure sensor according to claim 1, characterized in that: The connecting element includes a terminal (9) and a spring (10) connecting the terminal (9) and the circuit board (7), the terminal (9) being elongated.

3. The miniaturized, high-sealing gearbox pressure sensor according to claim 1, characterized in that: The lower housing (4) is bent inward at one end near the upper housing (3) to form a snap-fit ​​part (401), and the upper housing (3) is recessed to form a snap-fit ​​groove (301) for the snap-fit ​​part (401) to be snapped into. The first sealing part (5), the second sealing part (6) and the third sealing part (8) are all adhesive seals.

4. The miniaturized, high-sealing gearbox pressure sensor according to claim 2, characterized in that: The sensor also includes a frame (11) having a lower mounting cavity (1101) and an upper housing (3) having an upper mounting cavity (302). The lower mounting cavity (1101) and the upper mounting cavity (302) together form a spring mounting cavity for mounting the spring (10) and confining it inside.

5. The miniaturized, high-sealing gearbox pressure sensor according to claim 1, characterized in that: The sensor also includes a support ring (12) for supporting the circuit board (7) to separate it from the elastic base (1).

6. A miniaturized, high-sealing gearbox pressure sensor according to claim 5, characterized in that: The support ring (12) is bent at one end near the circuit board (7) to form a support part (1201), and the other end is bent to form a fixing part (1202) for welding and fixing to the elastic base (1).

7. The miniaturized, high-sealing gearbox pressure sensor according to claim 1, characterized in that: The flow channel (101) extends axially along the elastic base (1) and has an open end (102) through one end face, and a closed end (103) at the other end. The strain gauge (2) is attached to the closed end (103).

8. The miniaturized, high-sealing gearbox pressure sensor according to claim 1, characterized in that: The outer peripheral wall of the elastic base (1) is recessed to form a blocking part (104) for blocking the installation stress from the mounting surface.

9. A miniaturized, high-sealing gearbox pressure sensor according to claim 2, characterized in that: The spring (10) and the terminal (9) are both of several and are circumferentially spaced. Each terminal (9) is bent in the direction away from the other terminals (9) at one end near its corresponding spring (10) to form a bent portion (901) for connecting with the spring (10).

10. A miniaturized, high-sealing gearbox pressure sensor according to claim 4, characterized in that: The frame (11) is press-fitted to the outer shell, and the outer peripheral wall of the frame (11) and the inner peripheral wall of the outer shell respectively have a protruding positioning part (1102) and a recessed positioning groove (403) for the positioning part (1102) to be inserted.

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