Filter differential pressure indicator with temperature lock

Abstract

The application relates to a filter differential pressure indicator with a temperature locking function in the technical field of filters, which comprises a shell, an inner cavity is divided into an indicating cavity, a high-pressure cavity and a low-pressure cavity by a fixed partition plate and a lower piston in the shell, an elastic element is arranged in the low-pressure cavity, the lower piston is in sliding sealing with the low-pressure cavity, a first protruding column is fixed at the central upper end surface of the lower piston, the central plate surface of the fixed partition plate is upwardly protruded to form a protruding cover part, a first sliding sleeve is arranged in the indicating cavity and is sleeved on the outer wall of the protruding cover part, ring magnetic steel is embedded in the first sliding sleeve, an indicating part is arranged above the first sliding sleeve, the upper part and the lower part of the high-pressure cavity are respectively provided with a movable plate and a temperature locking metal sheet, the central upper plate surface of the movable plate is fixed with a second protruding column which is adaptively inserted into a groove of the protruding cover part, column magnetic steel is embedded in the second protruding column, and the lower plate surface of the movable plate is correspondingly connected with the upper end of the first protruding column; the differential pressure indicator can directly sense the oil temperature for locking, and the accuracy and flexibility of the differential pressure indicator are improved.

Description

Technical Field

[0001] This invention relates to the field of filter technology, and in particular to a filter differential pressure indicator with a temperature lock-in function. Background Technology

[0002] As is well known, filters are key components in fluid contamination control. Some systems require filters to monitor filter element clogging and issue alarm signals when clogging occurs. Therefore, differential pressure indicators are often installed on these filters to detect clogging. Filter element alarm methods include mechanical alarms, electrical signal alarms, and electromechanical alarms. Due to the higher viscosity of the oil under low-temperature start-up conditions, the filter element flow resistance is higher, which can easily cause false alarms. Therefore, differential pressure indicators generally need to specify a lock-in temperature. Above a certain temperature range, the lock-in device unlocks, and the differential pressure indicator can then activate its alarm function. Below a certain temperature, under the limiting action of the lock-in device, even if the filter element flow resistance reaches the specified alarm value, the differential pressure indicator alarm will not activate.

[0003] Most existing locking devices have complex structures and are located outside the differential pressure indicator, in an area completely isolated from the working medium. They cannot directly sense the oil temperature and are only affected by the ambient air temperature and the heat conduction of the metal to lock or unlock. Because the temperature rise of the ambient air is delayed, under some operating conditions, the locking and unlocking actions of the differential pressure indicator are not synchronized with the oil temperature, which can cause the differential pressure indicator to malfunction. Summary of the Invention

[0004] In order to overcome the shortcomings of the prior art and solve the existing technical problems, the present invention discloses a filter differential pressure indicator with temperature lock-up function, which can directly sense the oil temperature to lock up, thereby improving the accuracy and flexibility of the differential pressure indicator.

[0005] To achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0006] A filter differential pressure indicator with temperature lock-up function includes a housing with a vertical inner cavity. The housing is divided into an indicator chamber and a high-pressure chamber and a low-pressure chamber, respectively connected to the high-pressure and low-pressure sides of the filter element, by a fixed partition and a lower piston arranged vertically. The low-pressure chamber contains an elastic element that abuts against the lower end of the lower piston, causing it to move upwards. The outer wall of the lower piston is slidably sealed to the wall of the low-pressure chamber. A first protrusion is fixed at the center of the upper end face of the lower piston. The fixed partition has a raised, grooved cover portion at its center. A first... The sliding sleeve has an embedded annular magnet and an indicator that can pop up to trigger an alarm. The upper and lower parts of the high-pressure chamber are respectively provided with a movable plate and a temperature-locking metal plate. The upper plate of the movable plate has a second protruding post that is adapted to be inserted into the groove of the convex cover. The second protruding post has a column magnet that can be inserted into the annular magnet in an attractive state and detached from the annular magnet in a repulsive state. The lower plate of the movable plate is connected to the upper end of the first protruding post. The temperature-locking metal plate can resist and block the downward movement of the movable plate in the low-temperature locked state, and allow the movable plate to move downward in the high-temperature unlocked state.

[0007] Furthermore, the first protrusion is embedded with a ferromagnetic body that can be magnetically connected to the column magnet, and a second sliding sleeve is fixed in the center of the lower plate surface of the movable plate and slidably sleeved on the outer wall of the first protrusion. The outer diameter of the second sliding sleeve is smaller than the outer diameter of the lower piston.

[0008] Furthermore, the movable plate surface is provided with a vent hole that connects the inner cavity of the second sliding sleeve and the high-pressure cavity.

[0009] Furthermore, the housing includes an upper sleeve and a lower sleeve threaded to the lower port of the upper sleeve. The fixed partition is fixed inside the upper sleeve, the lower piston is slidably fitted inside the middle of the lower sleeve, and a plug is threaded to the lower port of the lower sleeve.

[0010] Furthermore, a limiting groove is provided at the center of the lower end face of the lower piston and at the center of the upper end face of the plug. The elastic element is a spring, and the two ends of the spring are respectively fitted into the two limiting grooves. A low-pressure through hole is provided at the bottom of the limiting groove of the plug.

[0011] Furthermore, the upper part of the inner cavity of the lower sleeve is expanded outward to form a stepped surface with the middle part, the temperature-locking metal sheet is disposed on the stepped surface, and the upper cavity wall of the inner cavity of the lower sleeve is provided with a high-pressure through hole.

[0012] Furthermore, the outer wall of the lower piston is provided with a sealing ring groove with a sealing ring.

[0013] Furthermore, the temperature-locking metal sheet is configured as a bimetallic sheet structure or a shape memory alloy sheet structure that can expand upon heating.

[0014] Furthermore, the required locking temperature of the temperature-locking metal sheet is ≤0℃, and the required unlocking temperature is ≥30℃.

[0015] Furthermore, the alarm differential pressure value of the indicator popping up is 0.5±0.07MPa.

[0016] By employing the technical solution described above, the present invention has the following beneficial effects:

[0017] This invention discloses a filter differential pressure indicator with a temperature-locking function. The temperature-locking metal strip is placed in the high-pressure chamber, directly contacting the working medium to sense temperature changes. If the temperature is too low, the temperature-locking metal strip structure contracts and locks, creating high-viscosity oil flow resistance and high pressure. This causes the lower piston to move a movable plate downwards, using the temperature-locking metal strip to block the movable plate, thus preventing the column magnet from detaching from the ring magnet. While maintaining the attraction, the ring magnet cannot move upwards to trigger the indicator alarm. Only when the temperature rises and the temperature-locking metal strip structure unfolds and unlocks can the false alarm caused by the low-temperature, high-viscosity oil flow resistance and high pressure be eliminated. This allows the movable plate to move smoothly downwards, causing the column magnet to detach from the ring magnet, resulting in end-to-end repulsion, which causes the column magnet to push the indicator upwards to trigger the alarm. The entire indicator structure of this invention is simple to control, and the temperature-locking action can be synchronized with oil temperature changes, greatly improving the accuracy and flexibility of the differential pressure indicator. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the in-situ state of the embodiment structure of the present invention;

[0019] Figure 2 This is a schematic diagram showing that the differential pressure indicator does not trigger an alarm under low-temperature lockout conditions;

[0020] Figure 3 This is a top view of the locked state of the temperature-locking metal sheet;

[0021] Figure 4 This is a schematic diagram showing the differential pressure indicator triggering an alarm under high temperature unlocking conditions;

[0022] Figure 5 This is a top-view diagram showing the unlocked state of the temperature-locking metal plate;

[0023] Figure 6 This is a schematic diagram of the reset state of the movable plate under low-temperature lockout conditions.

[0024] In the diagram: 1. Indicator; 2. Indicator cavity; 3. Fixed partition; 301. Protruding cover; 4. First sliding sleeve; 5. Ring magnet; 6. Second protruding post; 7. Column magnet; 8. Movable plate; 9. High-pressure chamber; 10. Second sliding sleeve; 11. Vent hole; 12. High-pressure through hole; 13. First protruding post; 14. Ferromagnetic body; 15. Lower piston; 16. Temperature-locking metal sheet; 17. Sealing ring; 18. Low-pressure chamber; 19. Elastic element; 20. Plug; 21. Low-pressure through hole; 22. Upper sleeve; 23. Lower sleeve. Detailed Implementation

[0025] The technical solution of the present invention will now be described with reference to the accompanying drawings of the embodiments of the present invention. In the description, it should be understood that the terms "upper," "lower," "front," "rear," "left," and "right," etc., indicating directions or positional relationships, are only used to correspond to the accompanying drawings of the present invention for the purpose of facilitating the description of the present invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation.

[0026] Example 1:

[0027] Combined with appendix Figure 1-5 The filter differential pressure indicator with temperature lock-up function includes a housing with a vertical inner cavity. The housing is divided into an indicator chamber 2 and a high-pressure chamber 9 and a low-pressure chamber 18, respectively connected to the high-pressure and low-pressure sides of the filter element, by a fixed partition 3 and a lower piston 15 arranged vertically. The size of the indicator chamber 2 remains constant, while the high-pressure chamber 9 and low-pressure chamber 18 experience a pressure difference as high-pressure and low-pressure oil flows in, pushing the lower piston 15 towards the low-pressure side, thereby changing the pressure difference between the high-pressure chamber 9 and low-pressure chamber 18. The size of 8; the low-pressure chamber 18 is provided with an elastic element 19, such as a spring sheet, that abuts against the lower end of the lower piston 15 to give it an upward tendency. The elastic element 19 can maintain the low-pressure chamber 18 and reset the lower piston 15. The outer wall of the lower piston 15 slides and seals with the cavity wall of the low-pressure chamber 18 to ensure that the high-pressure chamber 9 and the low-pressure chamber 18 will never be connected during the movement of the lower piston 15. If necessary, the outer wall of the lower piston 15 is provided with a sealing ring groove with a sealing ring 17 to isolate the high-pressure chamber 9 and the low-pressure chamber 18 through the sealing ring 17.

[0028] A first protrusion 13 is fixed at the center of the upper end face of the lower piston 15. The first protrusion 13 can be integrally connected with the lower piston 15. The center of the fixed partition plate 3 protrudes upward to form a convex cover 301 with a groove. The indicator cavity 2 is provided with a first sliding sleeve 4 that is slidably sleeved on the outer wall of the convex cover 301. The first sliding sleeve 4 is embedded with a ring magnet 5, which is also a ring magnet, and is coaxially fixed with the first sliding sleeve 4. Above the first sliding sleeve 4 is an indicator 1 that can pop up to alarm. The indicator 1 is popped up by the first sliding sleeve 4 moving upward. The alarm pressure difference force when the indicator 1 pops up to alarm is 0.5±0.07MPa. That is, when the pressure difference between the high pressure cavity 9 and the low pressure cavity 18 reaches 0.5±0.07MPa, an alarm is triggered. This pressure value can be adjusted by adjusting the elastic force of the elastic element 19.

[0029] The upper and lower parts of the high-pressure chamber 9 are respectively equipped with a movable plate 8 and a temperature-locking metal sheet 16. One end of the temperature-locking metal sheet 16 can be welded to the wall of the high-pressure chamber 9 for fixation. The temperature-locking metal sheet 16 is designed as a bimetallic sheet structure or a shape memory alloy sheet structure that can expand under heat. The bimetallic sheet structure is made by bonding two metal sheets with different thermal expansion rates together, so that it can achieve contraction and expansion at different temperatures. Like the shape memory alloy sheet, it is a common structure. The upper plate of the movable plate 8 is fixed with a second protruding post 6 that fits into the groove of the protruding cover 301. The second protruding post 6 is embedded with a columnar magnet 7 that can be inserted into the ring magnet 5 in an attractive state and detached from the ring magnet 5 in a repulsive state. Specifically, the maximum magnetic attraction force of the ring magnet 5 and the columnar magnet 7 is 2.16N. The columnar magnet 7 is also a columnar magnet. When it is detached from the ring magnet 5 and corresponds to its end face, it can push the ring magnet 5 upward through repulsion. Specifically, the maximum stroke of the columnar magnet 7 is 7mm. When the stroke is greater than When the diameter is 6mm, the force between the ring magnet 5 and the column magnet 7 changes from attraction to repulsion. The lower surface of the movable plate 8 is fixedly connected to the upper end of the first protruding column 13. The temperature-locking metal sheet 16 can be in a contracted state in the low-temperature locking state, resisting and blocking the downward movement of the movable plate 8, and in the high-temperature unlocking state, it is in an expanded state, allowing the movable plate 8 to move downward and pass through, thereby driving the column magnet 7 to disengage from the ring magnet 5. Specifically, the guaranteed locking temperature of the temperature-locking metal sheet 16 is ≤0℃, and the guaranteed unlocking temperature is ≥30℃. Since the structural change of the temperature-locking metal sheet 16 affected by temperature is a gradual process, and the viscosity change of the oil in the range of 0 to 30℃ is not significant, the impact on flow resistance is low. In actual operation, the heating process of the oil from 0 to 30℃ is relatively short. When the oil is in the range of 0 to 30℃, the temperature-locking metal sheet 16 can also be unlocked. However, when the temperature is below 0℃, the temperature-locking metal sheet 16 must be fully contracted to prevent false alarms.

[0030] In the filter differential pressure indicator with temperature lock-up function of the present invention, during normal operation, the working medium pressure on the outer and inner sides of the filter element is transmitted to the high-pressure chamber 9 and the low-pressure chamber 18, respectively. As the pressure difference between the inside and outside of the filter element increases, the lower piston 15 drives the movable plate 8 and the column magnet 7 to move downward together against the elastic force of the elastic element 19. When the oil temperature is not lower than 30°C, the temperature lock-up metal plate 16 is in the extended unlocked state, and the movable plate 8 is not blocked by the temperature lock-up metal plate 16. Instead, it continues to move downward as the pressure difference between the high-pressure chamber 9 and the low-pressure chamber 18 increases, until the column magnet 7 disengages from the ring magnet 5 and generates force on the ring magnet 5. The repulsive force causes the pressure difference at this point to be the alarm pressure value. The ring magnet 5 is driven by the repulsive force to move the first sliding sleeve 4 upward, which pushes the indicator 1 to pop up and trigger the alarm. When the oil temperature does not exceed 0°C, the temperature locking metal plate 16 is in a contracted and locked state. Even if the alarm pressure value is reached, the movable plate 8 will be blocked by the temperature locking metal plate 16, and its downward movement will be blocked. It cannot drive the column magnet 7 to disengage from the ring magnet 5, so the indicator 1 will not be triggered to pop up and trigger the alarm. When the pressure difference between the high pressure chamber 9 and the low pressure chamber 18 continues to decrease and is lower than the rebound force of the elastic element 19, the lower piston 15, the movable plate 8 and the column magnet 7 will move upward and reset.

[0031] Example 2:

[0032] When the alarm pressure is reached, but the temperature does not meet the requirements, if the movable plate 8 is continuously pressed against the temperature-locking metal sheet 16 which is in a contracted and locked state, it may damage the temperature-locking metal sheet 16. Therefore, the difference from Embodiment 1 is that the first protrusion 13 is designed to have a ferromagnetic body 14 embedded inside, which can be magnetically connected to the column magnet 7. A second sliding sleeve 10 is fixed in the center of the lower plate surface of the movable plate 8 and slidably sleeved on the outer wall of the first protrusion 13. The outer diameter of the second sliding sleeve 10 is smaller than the outer diameter of the lower piston 15. Firstly, when the temperature-locking metal plate 16 is in the expanded unlocked state, the movable plate 8 and the lower piston 15 can still connect and move synchronously due to the attraction of the cylindrical magnet 7 and the ferromagnetic body 14. However, when the temperature-locking metal plate 16 is in the contracted locked state, after the movable plate 8 moves down and touches the temperature-locking metal plate 16, even if the pressure difference continues to increase, the movable plate 8 cannot move. Meanwhile, the lower piston 15, along with the first protrusion 13, will continue to overcome the attraction and move downward under pressure, thereby increasing the distance between the ferromagnetic body 14 and the cylindrical magnet 7, as shown in the attached figure. Figure 6As shown, once the distance is increased, the attraction between the ferromagnet 14 and the cylindrical magnet 7 will decrease. At this time, the cylindrical magnet 7 has not completely detached from the ring magnet 5 because the movable plate 8 is blocked. The attraction above is still there, while the attraction below is weakened. This causes the movable plate 8 to move upward and detach from the temperature-locking metal sheet 16, thereby avoiding damage to the temperature-locking metal sheet 16. As needed, the surface of the movable plate 8 is provided with a vent hole 11 that connects the inner cavity of the second sliding sleeve 10 and the high-pressure chamber 9, so that the inner cavity of the second sliding sleeve 10 and the high-pressure chamber 9 are connected, preventing the formation of a vacuum cavity in the inner cavity of the second sliding sleeve 10, which would hinder the detachment of the second sliding sleeve 10 and the first protrusion 13.

[0033] Example 3:

[0034] The difference from Embodiment 1 is that the housing includes an upper sleeve 22 and a lower sleeve 23 threadedly connected to the lower port of the upper sleeve 22. A fixing partition 3 is fixed inside the upper sleeve 22. The lower piston 15 is slidably fitted into the middle of the lower sleeve 23. A plug 20 is threadedly connected to the lower port of the lower sleeve 23. The split structure facilitates disassembly, installation, and maintenance. As needed, a limiting groove is provided at the center of the lower end face of the lower piston 15 and the center of the upper end face of the plug 20. The elastic element 19 is a spring with a specific installation length of 13mm and a corresponding spring force of [missing information]. 10.3±1N, the two ends of the spring are respectively clamped in two limiting grooves, the bottom of the limiting groove of the plug 20 is provided with a low pressure through hole 21, the low pressure through hole 21 is used to connect to the low pressure side of the filter element, the spring force can be adjusted by turning the plug 20, and thus the alarm pressure can be adjusted; in addition, the upper diameter of the inner cavity of the lower sleeve 23 is expanded outward and forms a stepped surface with the middle part, the temperature locking metal plate 16 is provided on the stepped surface, and the step surface is used for support and limitation, the upper cavity wall of the inner cavity of the lower sleeve 23 is provided with a high pressure through hole 12, the high pressure through hole 21 is used to connect to the high pressure side of the filter element.

[0035] The parts of this invention not described in detail are prior art. It will be apparent to those skilled in the art that this invention is not limited to the details of the above exemplary embodiments, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the above embodiments should be regarded as exemplary and non-limiting in all respects. The scope of this invention is defined by the appended claims rather than the foregoing description. Therefore, it is intended to include all changes that fall within the meaning and scope of the equivalents of the claims within this invention, and no reference numerals in the claims should be regarded as limiting the content of the claims.

Claims

1. A filter differential pressure indicator with temperature lockout function, characterized in that: The housing includes a shell with a vertical inner cavity. The inner cavity is divided into an indicator chamber (2) and a high-pressure chamber (9) and a low-pressure chamber (18) respectively connected to the high-pressure and low-pressure sides of the filter element by a fixed partition (3) and a lower piston (15) arranged vertically. The low-pressure chamber (18) contains an elastic element (19) that abuts against the lower end of the lower piston (15), causing it to have an upward tendency. The outer wall of the lower piston (15) is slidably sealed to the wall of the low-pressure chamber (18). A first protruding post (13) is fixed at the center of the upper end face of the lower piston (15). The center of the fixed partition (3) protrudes upward to form a convex cover (301) with a groove. The indicator chamber (2) contains a first sliding sleeve (4) that slides onto the outer wall of the convex cover (301). A ring magnet (5) is embedded in the first sliding sleeve (4). An indicator (1) that can pop up to trigger an alarm is located above the first sliding sleeve (4). The high-pressure chamber (9) contains… The upper and lower parts are respectively provided with a movable plate (8) and a temperature-locking metal sheet (16). The upper plate of the movable plate (8) is fixed with a second protruding post (6) adapted to be inserted into the groove of the protruding cover (301). The second protruding post (6) is embedded with a column magnet (7) that can be inserted into the ring magnet (5) in an attractive state and detached from the ring magnet (5) in a repulsive state. The lower plate of the movable plate (8) is connected to the upper end of the first protruding post (13). The first protruding post (13) is embedded with a ferromagnetic body (14) that can be magnetically connected with the column magnet (7). The lower plate of the movable plate (8) is fixed with a second sliding sleeve (10) that is slidably sleeved on the outer wall of the first protruding post (13). The outer diameter of the second sliding sleeve (10) is smaller than the outer diameter of the lower piston (15). The temperature-locking metal sheet (16) can resist and block the downward movement of the movable plate (8) in the low-temperature locked state, and allow the movable plate (8) to move downward through in the high-temperature unlocked state.

2. The filter differential pressure indicator with temperature lockout function according to claim 1, characterized in that: The movable plate (8) has a vent (11) on its surface that connects the inner cavity of the second sliding sleeve (10) and the high-pressure cavity (9).

3. The filter differential pressure indicator with temperature lockout function according to claim 1, characterized in that: The housing includes an upper sleeve (22) and a lower sleeve (23) threaded to the lower port of the upper sleeve (22). The fixed partition (3) is fixed inside the upper sleeve (22). The lower piston (15) is slidably fitted in the middle of the lower sleeve (23). The lower port of the lower sleeve (23) is threaded with a plug (20).

4. The filter differential pressure indicator with temperature lockout function according to claim 3, characterized in that: The lower end face of the lower piston (15) and the upper end face of the plug (20) are both provided with limiting grooves. The elastic element (19) is a spring, and the two ends of the spring are respectively fitted into the two limiting grooves. The bottom of the limiting groove of the plug (20) is provided with a low-pressure through hole (21).

5. The filter differential pressure indicator with temperature lockout function according to claim 3, characterized in that: The upper part of the inner cavity of the lower sleeve (23) is expanded outward to form a stepped surface with the middle part. The temperature-locking metal sheet (16) is provided on the stepped surface. The upper cavity wall of the inner cavity of the lower sleeve (23) is provided with a high-pressure through hole (12).

6. The filter differential pressure indicator with temperature lockout function according to claim 1, characterized in that: The outer wall of the lower piston (15) is provided with a sealing ring groove with a sealing ring (17).

7. The filter differential pressure indicator with temperature lockout function according to claim 1, characterized in that: The temperature-locking metal sheet (16) is configured as a bimetallic sheet structure or a shape memory alloy sheet structure that can be expanded by heat.

8. The filter differential pressure indicator with temperature lockout function according to claim 1, characterized in that: The temperature locking metal sheet (16) has a locking temperature of ≤0℃ and a unlocking temperature of ≥30℃.

9. The filter differential pressure indicator with temperature lockout function according to claim 1, characterized in that: The alarm differential pressure value of the indicator (1) is 0.5±0.07MPa.

Images