Differential pressure measurement transmitter
By incorporating a lever-based displacement amplification design, along with linked pressure relief and alarm components, the temperature drift and overpressure damage issues of traditional differential pressure transmitters have been resolved. This enables high-precision measurement, automatic pressure relief, and real-time alarms, thereby improving the safety and lifespan of the equipment.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-04
- Publication Date
- 2026-03-27
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
Traditional differential pressure transmitters are prone to temperature drift when the ambient temperature changes or the equipment is damaged, and they lack automatic pressure relief function in case of accidental overpressure and overload, making them easy to damage.
It adopts a lever-amplified displacement design, a linkage pressure relief component, and a linkage alarm component. By amplifying the minute displacement of the measuring rod through the lever, a mechanical dial display is achieved. The linkage pressure relief component automatically releases pressure when there is overpressure, and the linkage alarm component emits an audible alarm when pressure is released.
It achieves long-term accuracy and stability in differential pressure measurement, protects core components from damage, enhances safety and service life, and provides immediate alarms in case of overpressure.
Smart Images
Figure CN121740324A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of transmitter, in particular to a differential pressure measurement transmitter. BACKGROUND
[0002] The differential pressure transmitter is a device for measuring the pressure difference between two different points, and converting the pressure difference into a standardized, remotely transmitted electrical signal, which is one of the most widely used and most important measuring instruments in the field of industrial process control. The core of the differential pressure transmitter is a pressure sensor, usually capacitive, silicon resonant or piezoresistive, and the high and low pressures are introduced into the two pressure interfaces respectively.
[0003] The displacement amount of the two measuring diaphragms of the traditional differential pressure transmitter is small, which is difficult to observe with the naked eye, and in the case of environmental temperature or instrument damage, it is easy to cause temperature drift, affecting the measurement accuracy, and in the case of accidental overpressure overload, the differential pressure transmitter itself does not have an automatic pressure relief function, which is easy to damage. SUMMARY
[0004] The purpose of the present application is to solve the problem of the traditional differential pressure transmitter in the prior art, which is easy to cause temperature drift in the case of environmental temperature or instrument damage, and in the case of accidental overpressure overload, the differential pressure transmitter itself does not have an automatic pressure relief function, which is easy to damage.
[0005] In order to achieve the above purpose, the present application adopts the following technical scheme: a differential pressure measurement transmitter, comprising a transmitter body and two diaphragm boxes, the transmitter body is provided with a high pressure cavity and a low pressure cavity, and the high pressure cavity and the low pressure cavity are separated by a displaceable pressure sensing element, the transmitter body is provided with a high pressure port and a low pressure port in communication with the internal high pressure cavity and low pressure cavity, one end of the diaphragm box is provided with a pressure transmission pipe, the two diaphragm boxes are fixedly communicated with the high pressure port and the low pressure port of the transmitter body through the pressure transmission pipe, the bottom of the diaphragm box is provided with a pressure introduction pipe for introducing high and low pressure, the side end of the diaphragm box is provided with a pressure relief pipe, the diaphragm box is movably inserted with a measuring rod with the same center as the pressure transmission pipe, one end of the measuring rod is fixedly installed with a piston movably inserted into the high pressure cavity and the low pressure cavity of the transmitter body, the piston and the pressure sensing element in the transmitter body are filled with an incompressible filling liquid, the top of the diaphragm box is fixedly installed with an indicating seat, further comprising: An amplification assembly is installed on the diaphragm box for amplifying the displacement amount of the measuring rod and cooperating with the indicating seat to display the displacement conversion amount; A pressure relief assembly is installed on the pressure relief pipe for automatically relieving pressure when the transmitter body is overloaded; An alarm assembly is installed on the pressure relief pipe for issuing an alarm when the transmitter body is overloaded.
[0006] In at least some embodiments, the amplification assembly comprises an adjusting sleeve and an indicating lever, the measuring rod is provided with a threaded segment at one end away from the piston, a plurality of guide rods are fixedly installed on the diaphragm box, and the adjusting sleeve is slidingly installed on the guide rods, the indicating lever is rotatably installed on the top of the diaphragm box, and a connecting rod is rotatably connected between the adjusting sleeve and the short force arm of the indicating lever.
[0007] In at least some embodiments, a threaded sleeve is rotatably installed on the diaphragm box and threadedly connected with the threaded segment of the measuring rod, one end of the indicating seat is provided with an arc surface with the same center as the shaft of the indicating lever, and the end of the indicating lever is marked with a pointer line, and the two side segments of the indicating seat are provided with scale lines.
[0008] In at least some embodiments, a first wedge block is movably inserted on the arc surface of the indicating seat, a second wedge block is movably inserted on the side end of the indicating seat, a third wedge block is fixedly installed on the inner side end of the first wedge block, a fourth wedge block is fixedly installed on the inner side end of the second wedge block and cooperates with the third wedge block, a spring is fixedly connected between the fourth wedge block and the inner wall of the indicating seat, and the fourth wedge block abuts against the third wedge block under the elastic force of the spring.
[0009] In at least some embodiments, the pressure relief assembly comprises a ball valve core and a lifting rod, the pressure relief pipe is provided with a valve seat and a mounting bracket, the ball valve core is located in the pressure relief pipe and is rotatably installed on the valve seat, one end of the shaft of the ball valve core penetrates through the valve seat and is fixedly installed with a plug-in seat, a torsional spring is fixedly installed between the shaft of the ball valve core and the valve seat, the lifting rod is longitudinally movably inserted into the mounting bracket of the pressure relief pipe, a plug-in head is fixedly installed on the bottom of the lifting rod, the plug-in head is designed with double plug-in rods, four plug-in holes are formed on the top of the plug-in seat and are adapted to the plug-in of the plug-in head, and a roller is rotatably installed on one end of the lifting rod away from the plug-in head and is in contact with the inclined surface of the second wedge block.
[0010] In at least some embodiments, two shielding plates are symmetrically fixedly welded at the top edge of the valve seat, four indicating pieces are fixedly and annularly pasted on the outer circular surface of the plug-in seat, and the colors of adjacent two indicating pieces are different.
[0011] In at least some embodiments, the alarm assembly comprises a cyclone head, a driven gear, an elastic piece, and a knocking seat, the outer end of the cyclone head is fixedly installed with a driving gear, the driven gear is rotatably installed on the side end of the diaphragm box and is in meshing connection with the driving gear, a wave wheel is fixedly installed on the shaft of the driven gear, the elastic piece is fixedly installed on the side end of the diaphragm box and is fixedly installed with a knocking needle at one end, the tip of the knocking needle is in contact with the wave wheel under the action of gravity, the knocking head is fixedly installed on the top of the knocking needle, the knocking seat is fixedly installed on the side end of the diaphragm box and is located directly above the knocking head, the wave wheel intermittently lifts the knocking needle in rotation and knocks the knocking seat through the knocking head to issue an alarm.
[0012] In at least some embodiments, the cyclone head is rotatably mounted at one end of the pressure relief pipe away from the diaphragm chamber, and an outer circular surface of the cyclone head is provided with a plurality of pressure relief holes arranged in an annular array and tangent to each other, and a plurality of guide vanes are fixedly welded in an annular array inside the cyclone head to guide the pressure to the pressure relief holes to drive the cyclone head to rotate during the pressure relief process.
[0013] Compared with the prior art, the application has the advantages and positive effects that: 1、In the application, the lever amplification displacement design is adopted, the linkage composed of the measuring rod, the screw sleeve, the adjusting sleeve, the connecting rod and the indicating lever is used to convert the small linear displacement of the measuring rod into the large angular displacement of the end of the indicating lever, and the pointer line at the end of the indicating lever is matched with the scale lines on both sides of the indicating seat to form a clear mechanical dial, thereby providing a direct visual reference of the differential pressure value for the operator, and the relative position of the rotating screw sleeve and the threaded section of the measuring rod can be changed to finely adjust the initial position of the measuring rod and the piston connected therewith, so that the convenient mechanical zero point calibration function is realized, the zero point drift caused by installation, temperature change or long-term use can be compensated, the long-term accuracy and stability of measurement are ensured, and the maintenance work is simplified.
[0014] 2、In the application, the linkage pressure relief design is adopted, when the overpressure occurs, the excessive deflection of the indicating lever is transmitted to the lifting rod through the wedge block group composed of the first wedge block, the third wedge block, the fourth wedge block, the spring and the second wedge block, so that the lifting rod is lifted and the locking on the ball valve core is released, the ball valve core is rapidly rotated by ninety degrees to be opened under the action of the torsional spring, the automatic pressure relief is realized, the indicating system and the protection system are creatively linked, and the overload self-sensing and automatic pressure relief are realized.
[0015] 3、In the application, the linkage alarm effect design is adopted, in the pressure relief process, the high-speed fluid drives the cyclone head to rotate, the meshing of the driving gear and the driven gear drives the impeller to rotate, the impeller periodically lifts the knocking needle, the knocking head continuously knocks the knocking seat, high-frequency sound is generated, the energy of the fault itself (the discharged fluid) is used, the self-driven acoustic alarm of the fault is realized, the device does not need to be wired and powered, and the sharp and harsh audible alarm can be sent at the same time of pressure relief, and the safety warning ability of the whole system is greatly enhanced. BRIEF DESCRIPTION OF DRAWINGS
[0016] Figure 1 An overall three-dimensional schematic view of the differential pressure measurement transmitter is provided for the application; Figure 2 A structural schematic view of the diaphragm chamber in the differential pressure measurement transmitter is provided for the application; Figure 3The application provides a structural schematic diagram of an amplification component in a differential pressure measurement transmitter. Figure 4 The application provides a structural schematic diagram of an internal structure of an indicating seat in a differential pressure measurement transmitter. Figure 5 The application provides a structural schematic diagram of a pressure relief component in a differential pressure measurement transmitter. Figure 6 The application provides a structural schematic diagram of a ball valve core in a differential pressure measurement transmitter. Figure 7 The application provides a structural schematic diagram of an alarm component in a differential pressure measurement transmitter. Figure 8 The application provides a structural schematic diagram of a rotational flow head in a differential pressure measurement transmitter.
[0017] Fig. 1 is a structural schematic diagram of a transmitter body. 2, a diaphragm box; 201, a pressure transmission pipe; 202, a pressure guide pipe; 203, a pressure relief pipe; 204, a measuring rod; 205, a piston; 3, an amplification component; 301, an adjusting sleeve; 302, an indicating lever; 303, a screw sleeve; 304, a connecting rod; 4, an indicating seat; 401, a first wedge block; 402, a second wedge block; 403, a third wedge block; 404, a fourth wedge block; 405, a spring; 5, a pressure relief component; 501, a ball valve core; 502, a lifting rod; 503, a plug-in seat; 504, a torsional spring; 505, an indicating sheet; 506, a plug; 507, a roller; 6, an alarm component; 601, a rotational flow head; 602, a driven gear; 603, an elastic sheet; 604, a knocking seat; 605, a driving gear; 606, a wave wheel; 607, a knocking needle; 608, a knocking head. DETAILED DESCRIPTION
[0018] In order to more clearly understand the above-mentioned purposes, features and advantages of the application, the application will be further described below in combination with the drawings and embodiments. It should be noted that the embodiments of the application and the features in the embodiments can be combined with each other without conflict.
[0019] In the following description, a lot of specific details are set forth in order to facilitate a thorough understanding of the application, however, the application can also be implemented in other ways different from the description, therefore, the application is not limited to the specific embodiments disclosed in the following description.
[0020] Embodiments, such as Figure 1As shown, the differential pressure measuring transmitter provided by the embodiment of the present application comprises a transmitter body 1 and two diaphragm chambers 2. The transmitter body 1 is internally provided with a high pressure chamber and a low pressure chamber, and the high pressure chamber and the low pressure chamber are separated by a displaceable pressure sensing element. The transmitter body 1 is provided with a high pressure port and a low pressure port which are in communication with the internal high pressure chamber and the low pressure chamber. The diaphragm chambers 2 are provided with a pressure delivery pipe 201 at one end. The two diaphragm chambers 2 are fixedly communicated with the high pressure port and the low pressure port of the transmitter body 1 through the pressure delivery pipe 201. The diaphragm chambers 2 are provided with a pressure introduction pipe 202 at the bottom for introducing high and low pressure. The diaphragm chambers 2 are provided with a pressure relief pipe 203 at the side end. The diaphragm chambers 2 are internally provided with a measuring rod 204 which is movably inserted and fitted with the pressure delivery pipe 201. One end of the measuring rod 204 is fixedly provided with a piston 205 which is movably inserted and fitted in the high pressure chamber and the low pressure chamber of the transmitter body 1. The piston 205 is filled with incompressible filling liquid between the piston 205 and the pressure sensing element in the transmitter body 1. The diaphragm chambers 2 are fixedly provided with an indicating seat 4 at the top. The differential pressure measuring transmitter further comprises an amplification assembly 3 which is mounted on the diaphragm chambers 2, for amplifying the displacement of the measuring rod 204 and cooperating with the indicating seat 4 to display the displacement conversion amount. The differential pressure measuring transmitter further comprises a pressure relief assembly 5 which is mounted on the pressure relief pipe 203, for automatically relieving pressure when the transmitter body 1 is overloaded. The differential pressure measuring transmitter further comprises an alarm assembly 6 which is mounted on the pressure relief pipe 203, for sending an alarm when the transmitter body 1 is overloaded.
[0021] As shown in Figure 2 and Figure 3 , the amplification assembly 3 comprises an adjusting sleeve 301 and an indicating lever 302. The measuring rod 204 is provided with a threaded section at the end away from the piston 205. The diaphragm chambers 2 are fixedly provided with a plurality of guide rods, and the adjusting sleeve 301 is slidably mounted on the guide rods. The indicating lever 302 is rotatably mounted on the top of the diaphragm chambers 2. A connecting rod 304 is rotatably connected between the adjusting sleeve 301 and the short force arm of the indicating lever 302. A screw sleeve 303 which is threadedly connected with the threaded section of the measuring rod 204 is rotatably mounted on the diaphragm chambers 2. One end of the indicating seat 4 is provided with an arc surface which is concentric with the shaft of the indicating lever 302. The end of the indicating lever 302 is provided with a pointer line, and the two side sections of the indicating seat 4 are provided with scale lines. Under normal differential pressure measurement state, the high pressure and low pressure media to be measured are introduced through the pressure introduction pipes 202 at the bottom of the two diaphragm chambers 2. The pressure acts on the piston 205 at one end of the measuring rod 204, and pushes the measuring rod 204 to generate an axial displacement which is proportional to the differential pressure value. The displacement is transmitted to the screw sleeve 303 through the threaded section. The movement of the measuring rod 204 drives the adjusting sleeve 301 to slide along the guide rods through the connecting rod 304. The movement of the adjusting sleeve 301 further pulls or pushes the short force arm of the indicating lever 302. By using the principle of lever, the long force arm end of the indicating lever 302 (i.e. the end with the pointer line) generates an amplified angular displacement on the arc surface of the indicating seat 4. The operator can directly read the current differential pressure measurement value and its change by observing the position of the pointer line on the scale lines of the indicating seat 4. The operator can manually rotate the screw 303 to fine tune the relative position of the screw 303 and the measuring rod 204, thereby fine tuning the initial zero point of the entire amplification mechanism, solving the temperature drift caused by the ambient temperature, and improving the measurement accuracy.
[0022] As shown in Figure 3 and Figure 4 , the first wedge block 401 is movably inserted on the arc surface of the indicating seat 4, the second wedge block 402 is movably inserted on the side end of the indicating seat 4, the third wedge block 403 is fixedly installed on the inner side end of the first wedge block 401, the fourth wedge block 404 is fixedly installed on the inner side end of the second wedge block 402 and cooperates with the third wedge block 403, and the spring 405 is fixedly connected between the fourth wedge block 404 and the inner wall of the indicating seat 4, and under the elastic force of the spring 405, the fourth wedge block 404 abuts against the third wedge block 403; When the system has an unexpected overpressure, the pressure in one side of the diaphragm box 2 is too high, and the displacement of the measuring rod 204 exceeds the safety threshold, the deflection angle of the indicating lever 302 increases, and the long force arm end of the indicating lever 302 presses the first wedge block 401 on the arc surface of the indicating seat 4 to move inward. The first wedge block 401 drives the third wedge block 403 inside it to move, overcoming the elastic force of the spring 405, pushing away the fourth wedge block 404 cooperated with it, and the movement of the fourth wedge block 404 drives the second wedge block 402 outside it to extend out of the indicating seat 4 to trigger the pressure relief assembly 5.
[0023] As shown in Figure 5 and Figure 6 , the pressure relief assembly 5 includes a ball valve core 501 and a lifting rod 502, the pressure relief pipe 203 is provided with a valve seat and a mounting bracket, the ball valve core 501 is located in the pressure relief pipe 203 and is rotatably installed on the valve seat, one end of the shaft of the ball valve core 501 penetrates through the valve seat and is fixedly installed with a plug-in seat 503, a torsional spring 504 is fixedly installed between the shaft of the ball valve core 501 and the valve seat, the lifting rod 502 is longitudinally movably inserted into the mounting bracket of the pressure relief pipe 203, a plug-in head 506 is fixedly installed at the bottom of the lifting rod 502, the plug-in head 506 adopts a double plug rod design, four insertion holes are formed at the top of the plug-in seat 503 and are adapted to the insertion of the plug-in head 506, and a roller 507 is rotatably installed at the end of the lifting rod 502 away from the plug-in head 506 and is in contact with the inclined surface of the second wedge block 402; Two blocking plates are symmetrically fixedly welded at the top edge of the valve seat, four indicating pieces 505 are fixedly and pasted on the outer circular surface of the plug-in seat 503 in a ring array, and the colors of adjacent two indicating pieces 505 are different; When the second wedge 402 extends outward toward the indicator seat 4, the inclined surface of the second wedge 402 pushes up the roller 507 at the top of the lifting rod 502 in the pressure relief assembly 5, forcing the lifting rod 502 to move upward. The plug 506 at the lower end of the lifting rod 502 rises accordingly, disengaging from the plug seat 503 and thus contacting the limit. Since the torsion spring 504 is pre-tightened, the ball valve core 501 rotates rapidly by about ninety degrees under the restoring torque of the torsion spring 504, aligning its internal flow channel with the pressure relief pipe 203. The pressure relief valve opens, and the high-pressure medium flows through the open ball valve core 501 and the pressure relief pipe 203. At the same time as the pressure is released, the indicator pieces 505 of different colors on the plug seat 503 rotate accordingly and are exposed from under the valve seat cover plate, for example, changing from a green "safety" indicator to a red "pressure relief" indicator, providing a visual warning.
[0024] like Figure 7 and Figure 8 As shown, the alarm assembly 6 includes a vortex head 601, a driven gear 602, an elastic sheet 603, and a vibrating seat 604. A driving gear 605 is fixedly installed on the outer end of the vortex head 601. The driven gear 602 is rotatably installed on the side end of the diaphragm box 2 and meshes with the driving gear 605. A pulsator 606 is fixedly installed on the shaft of the driven gear 602. The elastic sheet 603 is fixedly installed on the side end of the diaphragm box 2, and a vibrating needle 607 is fixedly installed on one end of the elastic sheet 603. The tip of the vibrating needle 607 contacts the pulsator 606 under the action of gravity. A vibrating head 608 is fixedly installed on the top of the vibrating needle 607. The vibrating seat 604 is fixedly installed on the side end of the diaphragm box 2 and located directly above the vibrating head 608. The pulsator 606 rotates intermittently, lifting the vibrating needle 607 and striking the vibrating seat 604 through the vibrating head 608 to trigger an alarm. The swirl head 601 is rotatably installed at the end of the pressure relief pipe 203 away from the diaphragm box 2. The outer circular surface of the swirl head 601 has tangent pressure relief holes in an annular array. Inside the swirl head 601, guide vanes are fixedly welded in an annular array to guide the pressure to the pressure relief holes, so as to drive the swirl head 601 to rotate during the pressure relief process. High-pressure medium is ejected from the pressure relief pipe 203 and flows through the vortex head 601 of the alarm component 6. The fluid impacts the guide vanes inside the vortex head 601, driving the vortex head 601 to rotate. The vortex head 601 drives the drive gear 605 to rotate, which in turn drives the driven gear 602 and the impeller 606 on its shaft to rotate through meshing. The wavy outer edge of the rotating impeller 606 periodically lifts the tip of the vibrating needle 607 in contact with it. The vibrating needle 607 overcomes the elastic force of the elastic plate 603 and moves upward, causing the vibrating head 608 at its top to strike the vibrating seat 604 above, producing a continuous, crisp knocking sound and emitting a strong sound. The auditory alarm alerts personnel. The entire process requires no external intervention or power, achieving automatic linkage of overpressure, pressure relief, and alarm. When the system overpressure is relieved and the pressure inside the diaphragm 2 returns to normal, the measuring rod 204 resets under the action of the internal filling liquid and pressure sensing element, the deflection angle of the indicating lever 302 decreases, the pressure on the first wedge 401 disappears, and the second wedge 402 resets inward under the action of the spring 405, no longer pushing up the lifting rod 502. The lifting rod 502 falls by its own weight, and the plug 506 at its lower end is reinserted into the corresponding socket of the plug seat 503 to prevent the pressure relief medium from causing the ball valve core 501 to rotate.
[0025] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments that can be applied to other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.
Claims
1. A differential pressure measuring transmitter, comprising a transmitter body (1) and two diaphragm capsules (2), characterized in that: The transmitter body (1) is provided with a high-pressure chamber and a low-pressure chamber, which are separated by a movable pressure-sensing element. The transmitter body (1) is provided with a high-pressure port and a low-pressure port that communicate with the internal high-pressure chamber and low-pressure chamber. One end of the diaphragm box (2) is provided with a pressure transmission pipe (201). The two diaphragm boxes (2) are fixedly connected to the high-pressure port and the low-pressure port of the transmitter body (1) respectively through the pressure transmission pipe (201). The bottom of the diaphragm box (2) is provided with a pressure-introducing pipe (202) for introducing high and low pressure. The diaphragm box (2) is provided with a pressure relief pipe (203) on its side end. A measuring rod (204) is movably inserted into the diaphragm box (2) and the pressure transmission pipe (201) in a circle. A piston (205) is fixedly installed at one end of the measuring rod (204) and is movably inserted into the high pressure chamber and the low pressure chamber of the transmitter body (1). An incompressible filling liquid is filled between the piston (205) and the pressure sensing element in the transmitter body (1). An indicator seat (4) is fixedly installed on the top of the diaphragm box (2). The diaphragm box (2) also includes: An amplification assembly (3) is installed on the diaphragm box (2) to amplify the displacement of the measuring rod (204) and to display the displacement conversion amount in conjunction with the indicator seat (4); A pressure relief assembly (5) installed on the pressure relief pipe (203) is used for automatic pressure relief when the transmitter body (1) is overloaded; An alarm assembly (6) is installed on the pressure relief pipe (203) to issue an alarm when the transmitter body (1) is under pressure overload.
2. A differential pressure measuring transmitter according to claim 1, characterized in that: The amplification component (3) includes an adjustment sleeve (301) and an indicator lever (302). The measuring rod (204) has a threaded section at the end away from the piston (205). Multiple guide rods are fixedly installed on the diaphragm box (2), and the adjustment sleeve (301) is slidably installed on the guide rods. The indicator lever (302) is rotatably installed on the top of the diaphragm box (2). A connecting rod (304) is rotatably connected between the adjustment sleeve (301) and the short lever (302).
3. A differential pressure measuring transmitter according to claim 2, characterized in that: The diaphragm box (2) is rotatably mounted with a threaded sleeve (303) that is threadedly connected to the threaded section of the measuring rod (204). One end of the indicator seat (4) is provided with an arc surface that is co-centered with the axis of the indicator lever (302). The end of the indicator lever (302) is engraved with pointer lines, and scale lines are opened on both sides of the indicator seat (4).
4. A differential pressure measuring transmitter according to claim 1, characterized in that: A first wedge (401) is movably inserted into the arc surface of the indicator seat (4), a second wedge (402) is movably inserted into the side end of the indicator seat (4), a third wedge (403) is fixedly installed on the inner end of the first wedge (401), a fourth wedge (404) that cooperates with the third wedge (403) is fixedly installed on the inner end of the second wedge (402), and a spring (405) is fixedly connected between the fourth wedge (404) and the inner wall of the indicator seat (4). Under the elastic force of the spring (405), the fourth wedge (404) abuts against the third wedge (403).
5. A differential pressure measuring transmitter according to claim 4, characterized in that: The pressure relief assembly (5) includes a ball valve core (501) and a lifting rod (502). A valve seat and mounting bracket are provided on the pressure relief pipe (203). The ball valve core (501) is located inside the pressure relief pipe (203) and rotatably mounted on the valve seat. One end of the shaft of the ball valve core (501) passes through the valve seat and is fixedly mounted with a plug-in seat (503). A torsion spring (504) is fixedly mounted between the shaft of the ball valve core (501) and the valve seat. The lifting rod (502)... 02) The lifting rod (502) is longitudinally inserted into the mounting bracket of the pressure relief pipe (203). The bottom of the lifting rod (502) is fixedly installed with a connector (506). The connector (506) adopts a double-rod design. The top of the connector seat (503) is provided with four insertion holes that are compatible with the connector (506). The end of the lifting rod (502) away from the connector (506) is rotatably installed with a roller (507) that contacts the inclined surface of the second wedge (402).
6. A differential pressure measuring transmitter according to claim 5, characterized in that: Two baffles are symmetrically welded to the top edge of the valve seat. Four indicator pieces (505) are fixedly pasted in a ring array on the outer surface of the plug-in seat (503). The colors of two adjacent indicator pieces (505) are different.
7. A differential pressure measuring transmitter according to claim 1, characterized in that: The alarm component (6) includes a vortex head (601), a driven gear (602), an elastic sheet (603), and a vibrating seat (604). A driving gear (605) is fixedly installed on the outer end of the vortex head (601). The driven gear (602) is rotatably installed on the side of the diaphragm box (2) and meshes with the driving gear (605). A pulsator (606) is fixedly installed on the shaft of the driven gear (602). The elastic sheet (603) is fixedly installed on the side of the diaphragm box (2) and springs back to the diaphragm box (2). A vibrating needle (607) is fixedly installed at one end of the diaphragm (603). The tip of the vibrating needle (607) contacts the impeller (606) under the action of gravity. A vibrating head (608) is fixedly installed on the top of the vibrating needle (607). The vibrating seat (604) is fixedly installed on the side of the diaphragm box (2) and located directly above the vibrating head (608). The impeller (606) rotates intermittently to lift the vibrating needle (607) and strike the vibrating seat (604) through the vibrating head (608) to issue an alarm.
8. A differential pressure measuring transmitter according to claim 7, characterized in that: The vortex head (601) is rotatably installed at the end of the pressure relief pipe (203) away from the diaphragm (2). The outer circular surface of the vortex head (601) is provided with tangent pressure relief holes in an annular array. Inside the vortex head (601), guide vanes are fixedly welded in an annular array to guide the pressure to the pressure relief holes, so as to drive the vortex head (601) to rotate during the pressure relief process.