Pressure switch

Abstract

The utility model discloses a pressure switch, which comprises a plug and a lower seat, the plug and the lower seat are spliced to form a closed movable cavity, the inner wall of the movable cavity is provided with a first ring groove, the first ring groove is covered with a sealing diaphragm, one side of the sealing diaphragm is provided with a pushing piece, the other side of the sealing diaphragm is provided with a switch assembly, and the inner wall of a sliding cavity is provided with a second ring groove. A limiting ring covers the interior of the second annular groove and is made of a hard material, and the side, facing the pushing piece, of the limiting ring abuts against the sealing diaphragm; a third ring groove is formed in the inner wall of the movable cavity, when the third ring groove is subjected to cold extrusion forming, the side, facing the limiting ring and back on to the sealing diaphragm, of the third ring groove is wrapped to form a ring edge, the ring edge abuts against and fixes the limiting ring, and the heat shrinkage rate of the limiting ring is obviously lower than that of a traditional plastic plug. The ring edge wraps and fixes the limiting ring, it is ensured that the limiting ring exerts stable pressing force on the sealing diaphragm, and the sealing performance of the sealing diaphragm is improved.

Description

Technical Field

[0001] This application relates to the technical field of pressure switches, and in particular to a pressure switch. Background Technology

[0002] In the field of automotive transmissions, pressure switches are widely used to monitor pressure changes inside the transmission, thereby ensuring the normal operation of the transmission under different working conditions. In the transmission oil circuit system, oil pressure changes are crucial to the transmission's working state. Excessive or insufficient oil pressure will affect the efficiency and lifespan of the gear transmission inside the transmission. Pressure switches can monitor oil pressure changes in real time and convert pressure signals into electrical signals in a timely manner, thereby ensuring that the transmission is always in the best working condition.

[0003] However, in existing pressure switch designs, pressure switches typically include a plug and a lower socket. The front end of the lower socket has an opening, and the rear end has a push chamber. A sealing diaphragm is also installed inside the lower socket, separating the opening and the push chamber. A switch assembly is installed inside the opening, and a push rod is slidably installed inside the push chamber. The other end of the push rod is connected to the hydraulic system of the automotive transmission. When the pressure in the hydraulic system changes, the push rod will move under the pressure in the hydraulic system. If oil in the hydraulic system flows into the push chamber, the sealing diaphragm can prevent oil from flowing into the opening, thus achieving a sealing effect between the push chamber and the opening.

[0004] However, in actual use, the sealing diaphragm is usually secured by a plug directly pressed against it. The plug exerts pressure on the diaphragm to fix it in place. The plug is usually made of plastic. Due to the large temperature fluctuations in the gearbox's operating environment, the plastic material is prone to brittle shrinkage at low temperatures and softening and expanding at high temperatures. This reduces the pressure of the plug on the sealing diaphragm, causing a gap between the diaphragm and the plug. This leads to problems such as inadequate sealing, loosening, or even detachment of the sealing diaphragm. A loose sealing diaphragm not only reduces the accuracy of oil pressure detection but may also contaminate the switching components due to oil leakage, affecting the reliability and service life of the pressure switch. Summary of the Invention

[0005] To ensure that the sealing diaphragm maintains good sealing performance under different operating conditions, a pressure switch is provided.

[0006] The above-mentioned objective of this application is achieved through the following technical solution:

[0007] A pressure switch includes a plug and a lower seat. The plug is inserted into the lower seat, and the two are joined to form a sealed movable cavity. The inner wall of the movable cavity is provided with a first annular groove, and a sealing diaphragm is covered in the first annular groove. A pusher is provided on one side of the sealing diaphragm along the direction in which the plug is inserted into the lower seat, and a switch assembly is provided on the other side of the sealing diaphragm. The inner wall of the sliding cavity is provided with a second annular groove on the side of the first annular groove opposite to the pusher. A limit ring is covered in the second annular groove. The limit ring is made of a rigid material and abuts against the sealing diaphragm on the side of the limit ring facing the pusher.

[0008] The inner wall of the active cavity is provided with a third annular groove on the side of the second annular groove facing away from the first annular groove. When the third annular groove is cold extruded, the third annular groove covers the side of the limiting ring facing away from the sealing diaphragm to form an annular edge, and the annular edge abuts against and fixes the limiting ring.

[0009] By adopting the above technical solution, the limiting ring is made of a rigid material with a significantly lower thermal shrinkage rate than traditional plastic plugs. It can apply continuous clamping force to the sealing diaphragm in the high and low temperature alternating environment of the gearbox, effectively offsetting the displacement of the diaphragm caused by thermal expansion and contraction, reducing the risk of loosening. At the same time, the ring formed during the cold extrusion molding of the third ring groove covers and fixes the side of the limiting ring facing away from the sealing diaphragm. Mechanical locking is achieved through metal plastic deformation, preventing the limiting ring from loosening in the moving cavity. This ensures that the limiting ring applies a stable clamping force to the sealing diaphragm, improves the fixing effect and sealing performance of the sealing diaphragm, and enhances the stability of the pressure switch under different temperature changes.

[0010] Preferably, the sealing diaphragm includes an annular sealing end, a limiting end is fixed on the circumferential sidewall of the sealing end, and a first annular protrusion is fixed on the inner circumferential sidewall of the limiting ring facing the sealing diaphragm, and the first annular protrusion is distributed opposite to the limiting end.

[0011] By adopting the above technical solution, the limiting end of the sealing diaphragm and the first annular protrusion on the inner circumferential sidewall of the limiting ring are distributed in opposite directions to form a mechanical interlocking structure. The physical limiting prevents the sealing diaphragm from radially displacing when the oil pressure or temperature changes. At the same time, the annular sealing end is tightly fitted with the inner wall of the moving cavity to form multiple sealing barriers, which significantly improves the oil sealing performance and avoids leakage and contamination of the switch components.

[0012] Preferably, the inner wall of the movable cavity is provided with a fourth annular groove on the side of the third annular groove facing away from the second annular groove, and a connecting ring is fixed on the outer wall of the plug, covering the fourth annular groove. The lower seat is provided with a pressing end that presses against the outer wall of the plug at one end facing away from the plug insertion direction, and an elastic pad is provided between the pressing end and the connecting ring.

[0013] By adopting the above technical solution, the plug will shrink in the environment of alternating high temperature and low temperature. The connecting ring in the fourth ring groove and the lower seat pressing end are pressed together by the elastic pad. The elastic pad can absorb the assembly stress when the plug and the lower seat are assembled, compensate for the difference in thermal expansion and contraction of the material, and prevent the connecting ring from loosening. At the same time, the pressing end abuts against the outer wall of the plug to further enhance the structural rigidity.

[0014] Preferably, the movable cavity is provided with an adjustment plate covering the third annular groove, and the adjustment plate is connected to the plug.

[0015] By adopting the above technical solution, and by setting the thickness of the adjusting plate to an adjustable structure, the pressure switch can be adapted to lower seats of different sizes. When the plug is inserted into the lower seat, the gap between the bottom of the third ring groove and the end of the plug can be compensated by increasing or decreasing the thickness of the adjusting plate or replacing it with an adjusting plate of different specifications, ensuring a tight fit between the two. This improves the versatility of the pressure switch, avoids problems such as loose assembly, oil leakage, or detection failure caused by deviations in the dimensions of the lower seat, reduces the development cost of multi-specification molds, enhances the product's tolerance to machining errors in the gearbox housing, and ensures long-term sealing stability and measurement accuracy under extreme working conditions.

[0016] Preferably, a locking post is fixed to the side of the plug facing the adjustment plate, and the adjustment plate has a slot for inserting the locking post.

[0017] By adopting the above technical solution, the mechanical limiting effect of the locking pin and the locking slot is used to improve the connection stability between the adjusting plate and the plug, limit the axial and radial displacement of the adjusting plate, and prevent the adjusting plate from loosening or shifting due to vibration, hydraulic pressure impact or temperature change, thereby ensuring the long-term reliable fixed state of the adjusting plate after thickness adjustment.

[0018] Preferably, a second annular protrusion is fixed on the inner peripheral sidewall of the limiting ring facing away from the sealing diaphragm, and the second annular protrusion abuts against the side of the adjusting plate facing away from the plug.

[0019] By adopting the above technical solution, the adjusting plate can apply axial pressure to the limiting ring through the second annular protrusion, effectively limiting the axial and radial displacement of the limiting ring under oil pressure impact, vibration or temperature change. By utilizing the synergistic effect of mechanical limiting and elastic support, it ensures that the limiting ring always maintains a stable clamping force on the sealing diaphragm under extreme working conditions, avoiding sealing failure or detection error caused by loosening of the limiting ring, and significantly improving the reliability and durability of the pressure switch in complex gearbox environments.

[0020] Preferably, a gap is left between the outer wall of the limiting ring and the groove wall of the second ring groove.

[0021] By adopting the above technical solution, a gap is reserved between the outer wall of the limiting ring and the wall of the second ring groove, which facilitates the installation of the limiting ring in the second ring groove and provides space for the thermal expansion of the limiting ring, preventing deformation or jamming caused by interference fit at high temperature.

[0022] Preferably, a retaining ring is fixed to the bottom of the first annular groove near the sealing end, and the retaining ring abuts against the limiting end.

[0023] By adopting the above technical solution, the retaining ring at the bottom of the first annular groove abuts against the limiting end of the sealing diaphragm. The mechanical limiting prevents the sealing diaphragm from detaching from the moving cavity under oil pressure, ensuring that the limiting end is always tightly fitted to the groove wall of the first annular groove, thus avoiding the risk of leakage caused by the displacement of the sealing diaphragm.

[0024] In summary, this application includes at least one of the following beneficial technical effects:

[0025] 1. The retaining ring is made of a rigid material with low thermal shrinkage, and its coefficient of linear expansion is much lower than that of the plastic plug. When the temperature changes, the retaining ring can apply a continuous clamping force to the sealing diaphragm, counteracting the displacement of the diaphragm caused by thermal expansion and contraction, effectively avoiding the risk of loosening.

[0026] 2. By setting a third annular groove on the inner wall of the active cavity, and during the cold extrusion molding process, the third annular groove is made to cover the side of the limiting ring opposite to the sealing diaphragm to form an annular edge. The mechanical locking of the limiting ring is achieved by the plastic deformation of the metal. This structure does not require additional fasteners, which simplifies the assembly process and ensures that the axial position of the limiting ring is fixed by the ring edge abutting against it, thereby enhancing the limiting stability. Attached image description:

[0027] Figure 1 This is a schematic diagram of the structure of a pressure switch;

[0028] Figure 2 for Figure 1 A sectional view;

[0029] Figure 3 An exploded view of the parts between the lower seat and the plug;

[0030] Figure 4 This is a sectional view of the parts between the lower seat and the plug;

[0031] Figure 5 This is a cross-sectional view of the third annular groove after cold extrusion.

[0032] Reference numerals: 1. Plug; 11. Locking pin; 12. Connecting ring; 2. Lower seat; 21. Movable cavity; 22. First annular groove; 221. Locking ring; 23. Second annular groove; 24. Third annular groove; 241. Ring edge; 25. Fourth annular groove; 26. Pressing end; 3. Sealing diaphragm; 31. Sealing end; 32. Limiting end; 4. Pushing component; 5. Switch assembly; 51. Push rod; 52. Moving contact; 53. Moving contact; 54. Connecting component; 55. Stationary contact; 56. Return spring; 6. Limiting ring; 61. First annular protrusion; 62. Second annular protrusion; 7. Adjusting plate; 71. Locking groove; 72. Fixing hole; 8. Elastic pad. Detailed implementation method:

[0033] The following section provides a more detailed description, in conjunction with the accompanying diagrams:

[0034] As attached Figure 1 and attached Figure 2 As shown, a pressure switch includes a plug 1 and a lower seat 2. The plug 1 is made of plastic, and the lower seat 2 is made of metal. The plug 1 is inserted into the lower seat 2, and the two are interference-fitted to form a sealed movable cavity 21. The inner wall of the movable cavity 21 is provided with a multi-ring groove structure. A first ring groove 22 is provided on the inner wall of the movable cavity 21. A rubber sealing diaphragm 3 is covered in the first ring groove 22. The central area of ​​the sealing diaphragm 3 is arched in the direction opposite to the direction in which the plug 1 is inserted into the lower seat 2.

[0035] The sealing diaphragm 3 includes a sealing end 31 and a limiting end 32. The sealing end 31 is annular in shape, and the limiting end 32 is fixed on the outer peripheral sidewall of the sealing end 31. A retaining ring 221 is fixed on the bottom of the first annular groove 22 near the sealing end 31, and the retaining ring 221 abuts against the limiting end 32. The mechanical limiting prevents the sealing diaphragm 3 from detaching from the movable cavity 21 under the action of oil pressure, ensuring that the limiting end 32 is always tightly fitted with the groove wall of the first annular groove 22, and avoiding the risk of leakage caused by the displacement of the sealing diaphragm 3.

[0036] A pusher 4 is provided on one side of the sealing diaphragm 3 along the direction of the plug 1 being inserted into the lower seat 2. The pusher 4 is slidably connected inside the lower seat 2. One end of the pusher 4 is sealed to the diaphragm 3, and the other end of the pusher 4 extends through the lower seat 2 and is connected to the automotive transmission oil circuit system. When the pressure in the oil circuit changes, the pusher 4 will reciprocate towards or away from the sealing diaphragm 3.

[0037] As attached Figure 2 and attached Figure 3 As shown, a switch assembly 5 is provided on the side of the sealing diaphragm 3 facing away from the pusher 4. The switch assembly 5 includes a push rod 51. One end of the push rod 51 is perpendicularly abutted against the sealing diaphragm 3, and the other end of the push rod 51 is provided with a moving contact 52. The moving contact 52 is parallel to the plug 1, and two symmetrically distributed moving contacts 53 are provided on the side of the moving contact 52 facing the plug 1.

[0038] A power connector 54 is provided through the plug 1. One end of the power connector 54 extends out of the plug 1 and is electrically connected to the gearbox electrical system for outputting electrical signals. The other end of the power connector 54 is positioned towards the moving contact 52 and is provided with a stationary contact 55. There are two stationary contacts 55 and two power connectors 54. The two stationary contacts 55 and the two power connectors 54 are symmetrically distributed. The stationary contacts 55 are parallel to the moving contacts 53, and the two stationary contacts 55 correspond one-to-one with the two moving contacts 53.

[0039] The switch assembly 5 also includes a reset spring 56 located between the plug 1 and the moving contact 52. There are two reset springs 56, which are symmetrically distributed and perpendicular to the two moving contacts 53 respectively. The reset springs 56 can provide a stable and reliable reset force for the moving contact 52, ensuring that the moving contact 52 quickly returns to the initial position after the trigger electrical signal is completed.

[0040] When the oil pressure of the transmission oil circuit system drives the pusher 4 towards the low pressure of the sealing diaphragm 3, the pusher 4 will simultaneously drive the push rod 51 towards the plug 1, thereby causing the moving contact 53 and the stationary contact 55 to come into contact with each other and form an electrical signal. When the oil pressure of the transmission oil circuit system returns to normal, the pusher 4 is no longer in the low pressure push rod 51, and the elastic potential energy stored in the return spring 56 will press the moving contact 52 to move towards the side of the pusher 4, and the moving contact 53 and the stationary contact 55 will no longer come into contact, disconnecting the electrical signal connection.

[0041] A limiting ring 6 is also provided on the side of the sealing diaphragm 3 facing away from the pusher 4. The inner wall of the movable cavity 21 is provided with a second annular groove 23 on the side of the first annular groove 22 facing away from the pusher 4. The limiting ring 6 covers the second annular groove 23. The limiting ring 6 is made of hard material, and here it is made of zinc alloy. The side of the limiting ring 6 facing the pusher 4 abuts against the sealing diaphragm 3, and there is a gap between the outer wall of the limiting ring 6 and the groove wall of the second annular groove 23, so as to facilitate the installation of the limiting ring 6 in the second annular groove 23, and at the same time provide space for the thermal expansion of the limiting ring 6, preventing deformation or jamming caused by interference fit at high temperature.

[0042] As attached Figure 4 and attached Figure 5 As shown, a first annular protrusion 61 is fixed on the inner circumferential sidewall of the limiting ring 6 facing the sealing diaphragm 3, and the first annular protrusion 61 and the limiting end 32 are distributed in opposite directions to form a mechanical interlocking structure, which prevents the sealing diaphragm 3 from radially displacing when the oil pressure or temperature changes through physical limiting.

[0043] The movable cavity 21 is provided with a third annular groove 24 on the side of the second annular groove 23 facing away from the first annular groove 22. During cold extrusion molding, the third annular groove 24 will cover and fix the side of the limiting ring 6 facing away from the sealing diaphragm 3, forming an annular edge 241. The annular edge 241 abuts against the side of the limiting ring 6 facing away from the sealing diaphragm 3, and achieves mechanical locking through metal plastic deformation, so as to prevent the limiting ring 6 from loosening in the movable cavity 21 and ensure that the limiting ring 6 applies a stable clamping force to the sealing diaphragm 3.

[0044] The third annular groove 24 is covered with an adjusting plate 7. The adjusting plate 7 is made of metal or high-strength plastic and is annular in shape. The side of the adjusting plate 7 facing the plug 1 is connected to the plug 1. The thickness of the adjusting plate 7 is adjustable. By making the thickness of the adjusting plate 7 adjustable, the pressure switch can be adapted to lower seats 2 of different sizes. When the plug 1 is inserted into the lower seat 2, the gap between the bottom of the third annular groove 24 and the end of the plug 1 can be compensated by increasing or decreasing the thickness of the adjusting plate 7 or replacing it with an adjusting plate of different specifications, ensuring a tight fit between the two and improving the versatility of the pressure switch.

[0045] A locking post 11 is fixed on the side of the plug 1 facing the adjustment plate 7. The adjustment plate 7 has a slot 71 for the locking post 11 to be inserted into, and a fixing hole 72 for the top rod 51 to pass through. The mechanical limiting effect of the locking post 11 and the slot 71 improves the connection stability between the adjustment plate 7 and the plug 1 and limits the axial and radial displacement of the adjustment plate 7.

[0046] A second annular protrusion 62 is fixed on the inner circumferential side wall of the limiting ring 6 facing away from the sealing diaphragm 3, and the second annular protrusion 62 abuts against the side of the adjusting plate 7 facing away from the plug 1. The adjusting plate 7 can apply axial pressure to the limiting ring 6 through the second annular protrusion 62, effectively limiting the axial and radial displacement of the limiting ring 6 under oil pressure impact, vibration or temperature change, and ensuring that the limiting ring 6 always maintains a stable clamping force on the sealing diaphragm 3 under different working conditions.

[0047] A fourth annular groove 25 is provided in the movable cavity 21 on the side of the third annular groove 24 facing away from the second annular groove 23. A connecting ring 12 is fixed on the outer wall of the plug 1 and covers the fourth annular groove 25. The lower seat 2 is provided with a pressing end 26 at the end facing away from the insertion direction of the plug 1. The pressing end 26 is bent and presses against the outer wall of the contact. A rubber annular elastic pad 8 is provided between the pressing end 26 and the connecting ring 12. The plug 1 will shrink in the environment of alternating high temperature and low temperature. The connecting ring 12 in the fourth annular groove 25 and the pressing end 26 of the lower seat 2 are pressed together by the elastic pad 8. The elastic pad 8 can absorb the assembly stress when the plug 1 and the lower seat 2 are assembled, compensate for the difference in thermal expansion and contraction of the material, and prevent the plug 1 from loosening in the movable cavity 21.

[0048] Working principle

[0049] When the pressure in the transmission oil circuit system presses against the pusher 4, the pusher 4 will move toward the sealing diaphragm 3. The pusher 4 will simultaneously drive the push rod 51 to move toward the plug 1. The return spring 56 will be compressed and store elastic potential energy by the pressure of the moving contact piece. The moving contact head and the stationary contact head will abut against each other, and then the stationary contact head will output an electrical signal through the electrical connector 54.

[0050] Simultaneously, the pusher 4 compresses and deforms the sealing diaphragm 3. The limiting ring 6, through the fixing and limiting effect of the rigid material, always applies a clamping force to the sealing diaphragm 3 to prevent it from loosening due to thermal expansion and contraction. The ring edge 241 also covers and fixes the limiting ring 6. Mechanical locking is achieved through the plastic deformation of the metal to prevent the limiting ring 6 from loosening in the movable cavity 21. This ensures that the limiting ring 6 applies a stable clamping force to the sealing diaphragm 3, thereby improving the fixing effect and sealing performance of the sealing diaphragm 3.

[0051] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of protection claimed in this application.

Claims

1. A pressure switch, comprising a plug (1) and a lower socket (2), characterized in that, The plug (1) is inserted into the lower seat (2), and the two are joined together to form a sealed movable cavity (21). The inner wall of the movable cavity (21) is provided with a first annular groove (22), and a sealing diaphragm (3) is covered in the first annular groove (22). A pusher (4) is provided on one side of the sealing diaphragm (3) along the direction of the plug (1) being inserted into the lower seat (2), and a switch assembly (5) is provided on the other side of the sealing diaphragm (3). A second annular groove (23) is provided on the side of the sliding cavity located on the side of the first annular groove (22) facing away from the pusher (4). A limiting ring (6) is covered in the second annular groove (23). The limiting ring (6) is made of hard material, and the side of the limiting ring (6) facing the pusher (4) abuts against the sealing diaphragm (3). The inner wall of the active cavity (21) is provided with a third annular groove (24) on the side of the second annular groove (23) facing away from the first annular groove (22). When the third annular groove (24) is cold extruded, the third annular groove (24) covers the side of the limiting ring (6) facing away from the sealing diaphragm (3) to form an annular edge (241), and the annular edge (241) abuts against the fixed limiting ring (6).

2. A pressure switch according to claim 1, characterized in that, The sealing diaphragm (3) includes an annular sealing end (31), and a limiting end (32) is fixed on the circumferential sidewall of the sealing end (31). A first annular protrusion (61) is fixed on the inner circumferential sidewall of the limiting ring (6) facing the sealing diaphragm (3), and the first annular protrusion (61) and the limiting end (32) are distributed opposite to each other.

3. A pressure switch according to claim 1, characterized in that, The inner wall of the active cavity (21) is provided with a fourth annular groove (25) on the side of the third annular groove (24) facing away from the second annular groove (23). A connecting ring (12) is fixed on the outer wall of the plug (1) and covers the fourth annular groove (25). The lower seat (2) is provided with a pressing end (26) that presses against the outer wall of the plug (1) at one end facing away from the insertion direction of the plug (1), and an elastic pad (8) is provided between the pressing end (26) and the connecting ring (12).

4. A pressure switch according to claim 1, characterized in that, The active cavity (21) is provided with an adjustment plate (7) covering the third annular groove (24), and the adjustment plate (7) is connected to the plug (1).

5. A pressure switch according to claim 4, characterized in that, The plug (1) is fixed with a locking post (11) on the side facing the adjustment plate (7), and the adjustment plate (7) has a slot (71) for the locking post (11) to be inserted.

6. A pressure switch according to claim 4, characterized in that, The limiting ring (6) has a second annular protrusion (62) fixed on the inner circumferential sidewall of the side facing away from the sealing diaphragm (3), and the second annular protrusion (62) abuts against the side of the adjusting plate (7) facing away from the plug (1).

7. A pressure switch according to claim 1, characterized in that, A gap is left between the outer wall of the limiting ring (6) and the groove wall of the second ring groove (23).

8. A pressure switch according to claim 1, characterized in that, A retaining ring (221) is fixed on the bottom of the first annular groove (22) near the sealing end (31), and the retaining ring (221) abuts against the limiting end (32).

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