A high-temperature open-circuit self-protection type pressure transmitter

Abstract

The present invention provides a high-temperature open-circuit self-protection type pressure transmitter. The case has a stepped through-hole and a stepped surface. The piston block flange is located in the large-hole section, and a spring is clamped between the flange and the stepped surface. A sealed inner cavity is formed in the large-hole section between the upper cover and the piston block. The power circuit board is fixed, and the signal circuit board is fixed to the piston block, and a spring probe is welded and fixed on the upper surface. The probe head faces the tapered hole connection point opened on the power circuit board, and the hole wall of the tapered hole connection point is copper-clad and conductive. Under normal conditions, the spring is in a semi-compressed state, and the spring probe is in a fully compressed state. Under the upward elastic force provided by the spring, the probe head of the spring probe can form conduction by abutting against the corresponding tapered hole connection point on the power circuit board. When a short-circuit heating accident occurs, the internal pressure increases with the increase of temperature, pushing the piston down to disconnect the circuit, thereby realizing high-temperature open-circuit self-protection, and it can be restored for use after the fault is removed.

Description

Technical Field

[0001] The present invention relates to the technical field of pressure transmitters, and particularly to a high-temperature open-circuit self-protection type pressure transmitter. Background Art

[0002] As a key sensing device in the field of industrial process control, pressure transmitters are widely used in pressure monitoring systems in industries such as petrochemical, electric power, and metallurgical manufacturing. Its core function is to convert physical pressure signals into standard electrical signals for output, providing real-time data support for the automatic control of industrial equipment. However, due to uncontrollable factors such as the aging of electronic devices, the aging of insulation layers, or even incorrect wiring by users during the use of its internal integrated circuit, it may cause a large amount of heat generation due to a short circuit in the circuit, and even lead to fires and explosions. Most of the existing pressure transmitters use the method of adding fuses or fuses in the circuit for overcurrent protection. However, since fuses or fuses themselves are also electronic components, they have certain limitations. Either they cannot automatically recover, or their performance may decline or even fail in a specific environment, resulting in abnormal situations such as misjudgment or slow response. Summary of the Invention

[0003] In view of the problems existing in the prior art, the present invention provides a technical solution for a high-temperature open-circuit self-protection type pressure transmitter, which realizes overcurrent open circuit in a pure mechanical mechanism manner to solve the above technical pain points and more effectively and reliably prevent accidents from occurring.

[0004] The technical solution of the present invention is specifically as follows:

[0005] A high-temperature open-circuit self-protection type pressure transmitter includes a case, an upper cover, and a lower cover. The case has a stepped through-hole with a large-hole section and a small-hole section from top to bottom in sequence, and the connection between the large-hole section and the small-hole section is a circular step surface; it also includes a piston block, a flange is formed above the main body of the block, the flange is located in the large-hole section, and a spring is clamped between the flange and the step surface; the main body of the piston block is slidably and sealingly connected to the small-hole section, and the upper cover is fixed to the upper hole of the large-hole section and seals it, so as to form a sealed inner cavity between the upper cover and the piston block in the large-hole section;

[0006] The power circuit board is fixed to the upper end of the sealed inner cavity, the signal circuit board is located in the lower part of the sealed inner cavity and is fixed to the upper surface of the piston block, the upper surface of the signal circuit board is welded with a probe seat for fixing the spring probe, the probe head is vertically facing the tapered hole connection point opened on the power circuit board and matching the probe head one by one, and the hole wall of the tapered hole connection point is covered with copper for conductivity; in a normal state, the spring is in a semi-compressed state and the spring probe is in a fully compressed state, and under the upward elastic force provided by the spring, the probe head of the spring probe can form an electrical connection by abutting with the corresponding tapered hole connection point on the power circuit board, thereby making the circuit structure in the sealed inner cavity conductive, and when the pressure in the sealed inner cavity increases to the point where the piston block is forced to move downward to enable the probe head to disengage from the tapered hole connection point and disconnect the electrical connection, the circuit structure in the sealed inner cavity is formed into an open circuit state.

[0007] Furthermore, the lower cover is axially divided into two half-cover bodies, left and right, each half-cover body retains half of the barrel body and the flange body, and the two half-cover bodies can be screwed and fixed to the lower end of the case through the flange body and combined into a complete barrel body and flange body. The barrel cavity in the barrel body of the lower cover is coaxial with the small hole section of the case, thereby providing a cavity accommodating space for the lower part of the piston block to move downward; a limiting groove is formed on the side wall of the barrel body of the lower cover, and correspondingly, an arc-shaped protrusion is formed on the lower part of the piston block body. When the piston block moves down to the extreme position, the limiting groove on the side wall of the barrel body of the lower cover can embed and lock the arc-shaped protrusion on the piston block.

[0008] Furthermore, the wall thickness of the barrel body of the lower cover is relatively thin, and can be slightly deformed when squeezed by the piston.

[0009] Furthermore, a piston positioning key is formed on the step surface to assist in fool-proof positioning of the piston when installing the piston.

[0010] Furthermore, two springs are sandwiched between the flange and the step surface to provide elastic force for the piston block to rise toward the upper cover.

[0011] Furthermore, the bottoms of the two springs are respectively placed in corresponding spring placement holes opened on the step surface of the case.

[0012] Furthermore, the power circuit board is fixedly installed below the upper cover.

[0013] Furthermore, a second pin socket is welded on the power circuit board, and an electrical plug welded with a second flexible circuit board passes through the electrical plug mounting hole of the watch case and is locked on the watch case by an electrical plug locking nut. A fourth O-ring is compressed between the electrical plug locking nut and the watch case to ensure sealing, and the second flexible circuit board is soldered to the second pin socket to realize electrical connection between the electrical plug and the power circuit board.

[0014] Further, a first pin socket is also welded on the upper surface of the signal circuit board; the pressure sensing element with the first flexible circuit board welded thereon passes through the pressure sensing element mounting hole and is locked on the watch case by a pressure sensing element locking nut. A third O-ring is compressed between the pressure sensing element locking nut and the watch case to ensure sealing. The first flexible circuit board is soldered to the first pin socket to complete the connection between the pressure sensing element and the signal circuit board.

[0015] The signal circuit and the power supply circuit inside the present invention are elastically connected. When a short-circuit heating accident occurs, the internal pressure increases with the increase of temperature, and the generated pressure pushes the power supply circuit and the signal circuit to separate, thus realizing high-temperature open-circuit self-protection. Moreover, it can be restored for use after the fault is eliminated, improving the service life of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments and descriptions thereof of the present invention are used to explain the present invention and do not constitute an improper limitation to the present invention. For those of ordinary skill in the art, other related drawings can also be obtained based on these drawings without creative efforts.

[0017] Figure 1 is an exploded schematic view of an embodiment of the present invention;

[0018] Figure 2 is a top view schematic of the watch case;

[0019] Figure 3 is a top view schematic of the overall pressure transmitter;

[0020] Figure 4 is Figure 3 a sectional view taken along the line B-B in

[0021] Figure 5 is Figure 3 a sectional view taken along the line A-A and in the working state in

[0022] Figure 6 is Figure 3 a sectional view taken along the line A-A and in the open-circuit protection state in

[0023] Figure 7 is a three-dimensional schematic of the overall pressure transmitter.

[0024] Reference numerals in the drawings:

[0025] Lower watch case 1;

[0026] Watch case 2; Spring placement hole 2-1; Piston positioning key 2-2; Pressure sensing element mounting hole 2-3; Electrical plug mounting hole 2-4; First O-ring groove 2-5; Lower watch case mounting threaded hole 2-6; Upper watch case mounting threaded hole 2-7; Step surface 2-8;

[0027] Piston block 3; flange 3-1;

[0028] Signal circuit board 4;

[0029] Power supply circuit board 5; display screen 5-1; taper hole connection point 5-2;

[0030] Upper table cover 6; mask 7; spring 8; first O-ring 9; second O-ring 10; first pin socket 11; spring probe 12;

[0031] Pressure sensing element 13; pressure sensing element locking nut 13-1;

[0032] First flexible circuit board 14; third O-ring 15; electrical plug 16; electrical plug locking nut 16-1; second flexible circuit board 17; fourth O-ring 18; second pin socket 19. Detailed implementation manners

[0033] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other.

[0034] In the description of the embodiments of the present invention, it should be noted that the orientation or positional relationship indicated is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of this application is usually placed during use, or the orientation or positional relationship commonly understood by those skilled in the art. It is only for the convenience of describing the present invention or simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed or operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0035] "Multiple" as used in the present invention means two or more (including two). The terms "first", "second", etc. are only used for distinguishing descriptions and should not be construed as indicating or implying relative importance.

[0036] Unless otherwise clearly defined and limited, the terms "set", "installed", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium.

[0037] The present invention will be described in detail below with reference to the drawings and in combination with embodiments.

[0038] As shown in the figure, the watch case 2 has a stepped through-hole with a large-hole section and a small-hole section from top to bottom in sequence. The connection between the large-hole section and the small-hole section is an annular stepped surface 2-8. A flange 3-1 is formed above the main body of the piston block 3. The main body of the piston block 3 is sleeved into the small-hole section of the through-hole of the watch case 2, and a second O-ring 10 is used to form a seal between the main body of the piston block 3 and the inner wall of the small-hole section. The second O-ring is installed on the main body of the piston block 3 and moves up and down with the piston block 3, which is convenient for installation and ensures reliable sealing. This also means that the main body of the piston block 3 seals the small-hole section of the through-hole of the watch case 2, that is, the lower orifice.

[0039] The upper watch cover 6 is fixedly installed on the upper orifice of the through-hole of the watch case 2, that is, at the upper orifice of the large-hole section, by screws. A first O-ring 9 is clamped between the upper watch cover 6 and the watch case 2 to ensure sealing, and the face mask 7 and the upper watch cover 6 are bonded with sealant to ensure the sealing of the upper watch cover 6 itself. Therefore, the upper watch cover 6 seals and plugs the upper orifice of the through-hole of the watch case 2, that is, the upper orifice of the large-hole section.

[0040] Therefore, a sealed inner cavity is formed in the large-hole section between the upper watch cover 6 and the flange 3-1 of the piston block 3. Since the piston block 3 can move up and down relative to the upper watch cover 6 above, the volume of the sealed inner cavity can change with the internal pressure.

[0041] The flange 3-1 of the piston block 3 is placed in the large-hole section of the stepped through-hole of the watch case 2 and is located above the stepped surface 2-8. Two springs 8 are clamped between the flange 3-1 and the stepped surface 2-8 to provide an upward elastic force for the piston block 3 towards the upper watch cover 6. Specifically, the bottoms of the two springs 8 are respectively placed in the corresponding spring placement holes 2-1 opened on the stepped surface 2-8 of the watch case 2.

[0042] Combined Figure 2 As shown, a piston positioning key 2-2 is formed on the stepped surface 2-8, which plays a role in preventing misassembly to assist in positioning the piston during installation.

[0043] An electrical plug installation hole 2-4 and a pressure sensing element installation hole 2-3 that are always connected to the sealed inner cavity are opened on the inner wall of the large-hole section of the watch case 2.

[0044] The power supply circuit board 5 is installed below the upper watch cover 6 by 4 screws. A second pin socket 19 is welded on the power supply circuit board 5. The electrical plug 16 welded with the second flexible circuit board 17 passes through the electrical plug installation hole 2-4 of the watch case 2 and is locked on the watch case 2 by the electrical plug locking nut 16-1. A fourth O-ring 18 is compressed between the electrical plug locking nut 16-1 and the watch case 2 to ensure sealing. The second flexible circuit board 17 is soldered to the second pin socket 19 to realize the electrical connection between the electrical plug 16 and the power supply circuit board 5.

[0045] The signal circuit board 4 is fixedly installed on the upper surface of the piston block 3 by four screws, and the probe seat of the first pin seat 11 and four spring probes 12 are welded on the upper surface of the signal circuit board 4; the pressure-sensitive element 13 welded with the first flexible circuit board 14 passes through the pressure-sensitive element mounting hole 2-3, and is locked on the watch case 2 by the pressure-sensitive element locking nut 13-1, and the third O-ring 15 is compressed between the pressure-sensitive element locking nut 13-1 and the watch case 2 to ensure the seal, and the first flexible circuit board 14 is connected to the first pin seat 11 with soldering to complete the connection between the pressure-sensitive element 13 and the signal circuit board 4.

[0046] The probe head of the spring probe 12 of the signal circuit board 4 is vertically facing upward, and a tapered hole connection point 5-2 that matches the probe head of the spring probe 12 one by one is provided on the power circuit board 5, and the hole wall of the tapered hole connection point 5-2 is covered with copper for conductivity; under the normal state, under the upward elastic force provided by the spring 8, the probe head of the spring probe 12 can abut against the corresponding tapered hole connection point 5-2 on the power circuit board 5 to form conduction, so that the circuit structure in the sealed inner cavity maintains a passage state, and if the piston block 3 moves downward to enable the probe head of the spring probe 12 to detach from the tapered hole connection point 5-2 to form a short circuit, the circuit structure in the sealed inner cavity will be in a short circuit state.

[0047] Working principle:

[0048] The pressure medium reaches the pressure-sensitive element 13, and the pressure-sensitive element 13 can obtain an electrical signal through the physical deformation of the resistor on its pressure-sensitive diaphragm and circuit calculation. The signal is then processed by the signal circuit board 4, transmitted to the power circuit board 5 for processing, and then displayed on the display screen 5-1 thereon, providing the user with pressure collection and monitoring. The electrical plug 16 supplies power to the signal circuit board 4 through the power circuit board 5 and the spring probe 12.

[0049] The power circuit board 5 is fixed, while the signal circuit board 4 can move up and down within a certain range. After the product is assembled, the spring 8 is in a semi-compressed state, and the spring probe 12 is in a fully compressed state. Figure 5 As shown (working state), there are four tapered hole connection points 5-2 on the power circuit board 5 with the same tapered angle as the probe head. The hole wall of the tapered hole connection point 5-2 is covered with copper for conductivity. Under the action of the spring 8, the spring probe 12 is completely compressed to the tapered hole connection point 5-2 of the power circuit board to form conduction. At this time, power is supplied from the electrical plug, the entire product circuit is turned on, and it works normally; when uncontrollable factors occur and cause short circuit heating, the temperature of the sealed inner cavity of the pressure transmitter rises rapidly. According to the PV=nRT principle, the pressure in the inner cavity increases with the temperature, and a pressure difference appears above and below the piston block 3. The generated pressure pushes the piston block 3 to compress the spring 8 and move downward. When the piston block 3 moves to the point where the spring probe 12 leaves the power circuit board, the signal circuit board 4 cannot receive power and a circuit break occurs, and no longer continues to heat up, thereby achieving circuit break self-protection.

[0050] During normal operation, the heat generated by the circuit board will also cause the temperature to rise, which in turn drives the piston block 3 to compress the spring 8. However, since the spring probe 12 was in a fully compressed state before, that is, there is a certain amount of compression in the spring inside the probe, the small displacement of the probe holder following the piston block 3 will not cause the probe head to leave the power circuit board 5. In other words, the spring probe 12 has a certain built-in safety margin to ensure that the normal heat generation of the circuit board will not cause an open circuit effect.

[0051] As Figure 6 and in combination with Figure 1 As shown, the lower watch case 1 is axially cut into left and right half-cases. Each half-case retains half of the barrel part and the flange part. The two half-cases can be respectively screwed and fixed to the lower end of the watch case 2 through the flange part and combined into a complete barrel and flange. The barrel cavity in the barrel of the lower watch case is coaxial with the small hole section of the watch case 2, thus providing a cavity accommodation space for the downward movement of the lower part of the piston block 3.

[0052] The wall thickness of the lower watch case 1 is relatively thin and can undergo slight deformation under stress. Limited grooves are formed on the side wall of the barrel of the lower watch case. Correspondingly, an arc-shaped protrusion is formed at the lower part of the main body of the piston block 3. An inward avoidance is made at the arc-shaped protrusion (i.e., the maximum outer diameter of the arc-shaped protrusion is not greater than the maximum outer diameter of the main body of the block), so that the arc-shaped protrusion does not interfere during the movement in the small hole section of the watch case 2 and does not affect the movement of the piston block 3. When the piston block 3 moves to the limit position, the limited groove on the side wall of the barrel of the lower watch case 1 can embed and lock the arc-shaped protrusion on the piston block 3, so that after the temperature recovers, the piston block 3 cannot move upward to start a short circuit connection again (the elastic force of the spring 8 cannot push the piston block 3 out of the groove). In addition, the lower watch case 1 is divided into two parts left and right and is detachable. If a short circuit is caused by the user connecting the wires wrongly, the lower watch case 1 can be directly disassembled. The piston block 3 moves upward under the action of the spring 8 to resume normal operation. If a short circuit is caused by problems such as aging of internal electronic components or aging of the insulation layer of the circuit board, the upper watch case 6 can be first disassembled, the circuit board can be taken out, repaired and reinstalled after passing the inspection, and then the lower watch case 1 can be disassembled to restore the working state, flexibly dealing with faults and improving the service life of the product.

[0053] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A high-temperature open-circuit self-protection type pressure transmitter, comprising a meter housing, an upper meter cover and a lower meter cover, characterized in that, The watch case has a stepped through-hole with a large-hole section and a small-hole section from top to bottom in sequence. The connection between the large-hole section and the small-hole section is an annular step surface. It also includes a piston block. A flange is formed above the block body of the piston block. The flange is located in the large-hole section, and a spring is clamped between the flange and the step surface. The block body of the piston block is slidably and sealingly connected to the small-hole section. The upper watch cover is fixed to the upper orifice of the large-hole section and seals it, so that a sealed inner cavity is formed in the large-hole section between the upper watch cover and the piston block. The power circuit board is fixed to the upper end of the sealed inner cavity. The signal circuit board is located in the lower part of the sealed inner cavity and is fixed to the upper surface of the piston block. The probe seat of the spring probe is welded and fixed to the upper surface of the signal circuit board. The probe head is vertically oriented towards the tapered hole connection points opened on the power circuit board and matching with the probe head one by one. The hole wall of the tapered hole connection point is copper-clad and conductive. In the normal state, the spring is in a semi-compressed state, and the spring probe is in a fully compressed state. Under the upward elastic force provided by the spring, the probe head of the spring probe can form an electrical connection by abutting against the corresponding tapered hole connection points on the power circuit board, so that the circuit structure in the sealed inner cavity is conducted. When the pressure in the sealed inner cavity increases to a point where the piston block is forced to move downward until the probe head disengages from the tapered hole connection point and disconnects the electrical connection, the circuit structure in the sealed inner cavity is in an open state.

2. The high-temperature open-circuit self-protection type pressure transmitter according to claim 1, wherein The lower watch cover is axially cut into left and right half cover bodies. Each half cover body retains half of the barrel part and the flange part respectively. The two half cover bodies can be respectively screwed and fixed to the lower end of the watch case through the flange part and combined into a complete barrel and flange. The barrel cavity in the barrel of the lower watch cover is coaxial with the small-hole section of the watch case, thus providing a cavity accommodation space for the lower part of the piston block to move downward. A limiting groove is formed on the side wall of the barrel of the lower watch cover. Correspondingly, an arc-shaped protrusion is formed on the lower part of the block body of the piston block. When the piston block moves downward to the limit position, the limiting groove on the side wall of the barrel of the lower watch cover can embed and lock the arc-shaped protrusion on the piston block.

3. The high-temperature open-circuit self-protection type pressure transmitter according to claim 2, characterized in that, The wall thickness of the barrel of the lower watch cover is relatively thin and can undergo slight deformation when squeezed by the piston.

4. The high-temperature open-circuit self-protection type pressure transmitter according to claim 1, characterized in that, A piston positioning key is formed on the step surface to assist in anti-fool positioning of the piston during installation.

5. The high-temperature open-circuit self-protection type pressure transmitter according to claim 1, characterized in that, Two springs are clamped between the flange and the step surface to provide an upward elastic force for the piston block to rise towards the upper watch cover.

6. The high-temperature open-circuit self-protection type pressure transmitter according to claim 5, characterized in that, The bottom parts of the two springs are respectively placed in the corresponding spring placement holes opened on the step surface of the watch case.

7. The high-temperature open-circuit self-protection type pressure transmitter according to claim 1, characterized in that, The power circuit board is fixedly installed below the upper watch cover.

8. The high-temperature open-circuit self-protection type pressure transmitter according to claim 1, characterized in that, A second pin socket is welded on the power circuit board. The electrical plug welded with the second flexible circuit board passes through the electrical plug mounting hole of the watch case and is locked on the watch case by the electrical plug locking nut. A fourth O-ring is compressed between the electrical plug locking nut and the watch case to ensure sealing. The second flexible circuit board is soldered to the second pin socket to realize the electrical connection between the electrical plug and the power circuit board.

9. The high-temperature open-circuit self-protection type pressure transmitter according to claim 1, characterized in that, A first pin socket is also welded on the upper surface of the signal circuit board. The pressure-sensitive element welded with the first flexible circuit board passes through the pressure-sensitive element mounting hole and is locked on the watch case by the pressure-sensitive element locking nut. A third O-ring is compressed between the pressure-sensitive element locking nut and the watch case to ensure sealing. The first flexible circuit board is soldered to the first pin socket to complete the connection between the pressure-sensitive element and the signal circuit board.

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