High-temperature open-circuit self-protection type pressure transmitter

Abstract

The invention provides a high-temperature open-circuit self-protection type pressure transmitter. A meter shell is provided with a step-shaped through hole and a step surface; a piston block flange plate is located in the large hole section, and a spring is clamped between the flange plate and the step surface; a large hole section between the upper meter cover and the piston block forms a sealed inner cavity; the power supply circuit board is fixed, the signal circuit board is fixed with the piston block, a spring probe is welded and fixed on the upper surface of the signal circuit board, a probe head faces a taper hole connecting point arranged on the power supply circuit board, and the hole wall of the taper hole connecting point is coated with copper for conduction; in a normal state, the spring is in a half-compressed state, the spring probe is in a full-compressed state, and under the action of upward elastic force provided by the spring, a probe head of the spring probe can be connected through abutting against a corresponding taper hole connecting point on the power supply circuit board; when a short-circuit heating accident occurs, the internal pressure is increased along with temperature rise, and the piston is pushed to move downwards to disconnect the circuit, so that high-temperature open-circuit self-protection is realized, and the device can be recovered to use after a fault is removed.

Description

Technical Field

[0001] The present invention relates to the technical field of pressure transmitters, and in particular 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 energy, 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 the insulation layer, or even the wrong 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 cause 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 the fuse or fuse itself is also an electronic component, it has certain limitations. Either it cannot automatically recover, or its 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] Aiming at 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.

[0004] The technical solution of the present invention is specifically as follows: A high-temperature open-circuit self-protection type pressure transmitter includes a case, an upper case cover and a lower case cover. The 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 a circular 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 case cover is fixed to the upper orifice of the large hole section and seals it, so as to form a sealed inner cavity between the upper case cover and the piston block in the large hole section. The power supply circuit board is fixed to the upper end of the sealed inner cavity. The signal circuit board is located at 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, and the probe head is vertically oriented towards the tapered hole connection points opened on the power supply circuit board that are in one-to-one correspondence with the probe head. The inner 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 through abutting against the corresponding tapered hole connection points on the power supply circuit board, thereby making the circuit structure in the sealed inner cavity conductive. When the pressure in the sealed inner cavity increases and the piston block is forced to move downward to a position where the probe head can be disengaged from the tapered hole connection point to disconnect the electrical connection, the circuit structure in the sealed inner cavity will be in an open circuit state.

[0005] Further, 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, thereby providing a downward moving cavity accommodation space for the lower part of the piston block. 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 main 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.

[0006] Further, the wall thickness of the barrel of the lower watch cover is relatively thin and can undergo slight deformation when being squeezed by the piston.

[0007] Further, a piston positioning key is formed on the step surface to assist in anti-fool positioning of the piston during installation.

[0008] Further, 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.

[0009] Further, the bottoms of the two springs are respectively placed in the corresponding spring placement holes opened on the step surface of the watch case.

[0010] Further, the power supply circuit board is fixedly installed below the upper watch cover.

[0011] Further, a second pin socket is welded on the power supply 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 supply circuit board.

[0012] Further, a first pin socket is also soldered on the upper surface of the signal circuit board; the pressure-sensitive element with the first flexible circuit board welded thereto 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.

[0013] 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 rise of temperature, and the generated pressure pushes the power supply circuit and the signal circuit to separate, thereby 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

[0014] The drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions 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.

[0015] Figure 1 is an exploded schematic view of an embodiment of the present invention; Figure 2 is a top view schematic of the watch case; Figure 3 is a top view schematic of the overall pressure transmitter; Figure 4 is Figure 3 the sectional view taken along the line B-B in Figure 5 is Figure 3 the sectional view taken along the line A-A and in the working state in Figure 6 is Figure 3 the sectional view taken along the line A-A and in the open-circuit protection state in Figure 7 is a three-dimensional schematic of the overall pressure transmitter.

[0016] Reference numerals in the drawings: Lower watch case 1; Watch case 2; Spring placement hole 2-1; Piston positioning key 2-2; Pressure-sensitive 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; Piston block 3; Flange 3-1; Signal circuit board 4; Power supply circuit board 5; Display screen 5-1; Tapered hole connection point 5-2; The upper watch case 6; the facial mask 7; the spring 8; the first O-ring 9; the second O-ring 10; the first pin socket 11; the spring probe 12; The pressure-sensitive element 13; the pressure-sensitive element locking nut 13-1; The first flexible circuit board 14; the third O-ring 15; the electrical plug 16; the electrical plug locking nut 16-1; the second flexible circuit board 17; the fourth O-ring 18; the second pin socket 19. Specific embodiments

[0017] 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.

[0018] 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.

[0019] The "multiple" mentioned in the present invention refers to 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.

[0020] 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.

[0021] The present invention will be described in detail below with reference to the drawings and in combination with the embodiments.

[0022] 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 step surface 2-8; a flange 3-1 is formed above the block body of the piston block 3. The block body of the piston block 3 is sleeved into the small-hole section of the through-hole of the watch case 2, and a seal is formed between the block body and the hole wall of the small-hole section through the second O-ring 10. And the second O-ring is installed on the block 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 block body of the piston block 3 realizes the sealing of the small-hole section, that is, the lower hole opening, of the through-hole of the watch case 2.

[0023] The upper watch cover 6 is fixedly installed on the upper orifice of the through hole of the watch case 2 by screws, that is, at the upper orifice of the large hole section. 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.

[0024] 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.

[0025] 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 step surface 2-8. Two springs 8 are clamped between the flange 3-1 and the step 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 step surface 2-8 of the watch case 2.

[0026] Combined Figure 2 As shown, a piston positioning key 2-2 is formed on the step surface 2-8, which plays a role in preventing mistakes in assisting the positioning of the piston during installation.

[0027] 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 hole wall of the large hole section of the watch case 2.

[0028] The power supply circuit board 5 is installed under 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.

[0029] The signal circuit board 4 is fixedly installed on the upper surface of the piston block 3 by four screws. A first pin socket 11 and a probe socket of four spring probes 12 are welded on the upper surface of the signal circuit board 4. The pressure sensing element 13 welded with the first flexible circuit board 14 passes through the pressure sensing element installation hole 2-3 and is locked on the watch case 2 by the pressure sensing element locking nut 13-1. A third O-ring 15 is compressed between the pressure sensing element locking nut 13-1 and the watch case 2 to ensure sealing. The first flexible circuit board 14 is soldered to the first pin socket 11 to complete the connection between the pressure sensing element 13 and the signal circuit board 4.

[0030] The probe heads of the spring probes 12 on the signal circuit board 4 face vertically upward. On the power supply circuit board 5, there are tapered hole connection points 5-2 that match the probe heads of the spring probes 12 one by one. The inner walls of the tapered hole connection points 5-2 are copper-coated and conductive. Under normal conditions, under the upward elastic force provided by the spring 8, the probe heads of the spring probes 12 can abut against the corresponding tapered hole connection points 5-2 on the power supply circuit board 5 to form conduction, so that the circuit structure in the sealed inner cavity remains in a conductive state. If the piston block 3 moves downward to a position where the probe heads of the spring probes 12 are separated from the tapered hole connection points 5-2 to form an open circuit, the circuit structure in the sealed inner cavity will be in an open circuit state.

[0031] Working principle: The pressure medium reaches the pressure-sensing element 13. The pressure-sensing element 13 can obtain an electrical signal through the physical deformation of the resistance on its pressure-sensing diaphragm and circuit calculation. After being processed by the signal circuit board 4, it is transmitted to the power supply circuit board 5 for processing and then displayed on the display screen 5-1 thereon, providing pressure acquisition and monitoring for the user. The electrical plug 16 supplies power to the signal circuit board 4 through the power supply circuit board 5 and the spring probes 12.

[0032] The power supply 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 probes 12 are in a fully compressed state. As Figure 5 shown (working state), there are 4 tapered hole connection points 5-2 with the same taper angle as the probe heads on the power supply circuit board 5. The inner walls of the tapered hole connection points 5-2 are copper-coated and conductive. Under the action of the spring 8, the spring probes 12 are fully compressed to form conduction with the tapered hole connection points 5-2 on the power supply circuit board. At this time, power is supplied from the electrical plug, and the entire product circuit is conductive and works normally. When an uncontrollable factor causes a short circuit and heat generation, the temperature in the sealed inner cavity of the pressure transmitter rises rapidly. According to the PV=nRT principle, the internal pressure increases with the increase in temperature, and there is a pressure difference up and down 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 a position where the spring probes 12 leave the power supply circuit board, the signal circuit board 4 cannot receive power and an open circuit occurs, and it no longer continues to heat, achieving open circuit self-protection.

[0033] During normal operation, the heat generated by the circuit board will also cause the temperature to rise and push the piston block 3 to compress the spring 8. However, because the spring probes 12 were in a fully compressed state before, that is, there is a certain compression amount in the springs inside the probes, and the small displacement of the probe seat following the piston block 3 will not cause the probe heads to leave the power supply circuit board 5. That is to say, the spring probes 12 have a certain safety distance to ensure that the heat generated by the circuit board during normal operation will not cause an open circuit effect.

[0034] As Figure 6 and combined with Figure 1As shown, the lower watch cover 1 is axially cut into left and right semi-cover bodies. Each semi-cover body retains half of the barrel body part and the flange body part. The two semi-cover bodies can be respectively screwed and fixed to the lower end of the watch case 2 through the flange body part and combined into a complete barrel body and flange body. The barrel cavity in the barrel of the lower watch cover 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.

[0035] The wall thickness of the lower watch cover 1 is relatively thin and can undergo slight deformation under force. 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 main body of the piston block 3. An avoidance is made inward at the arc-shaped protrusion (that is, 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 limiting groove on the side wall of the barrel of the lower watch cover 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 cover 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 cover 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 devices or aging of the circuit board insulation layer, the upper watch cover 6 can be first disassembled, the circuit board can be taken out, repaired and reinstalled after passing the inspection, and then the lower watch cover 1 can be disassembled to restore the working state, flexibly coping with the failure and improving the service life of the product.

[0036] 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 principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A high temperature circuit breaker self-protection pressure transmitter, comprising a case, an upper cover and a lower cover, characterized in that: The case has a stepped through hole which is a large hole section and a small hole section from top to bottom, and 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 on the block body, the flange is located in the large hole section, and a spring is sandwiched between the flange and the step surface; the piston block body is slidably sealed with the small hole section, and the upper cover is fixed to the upper hole opening of the large hole section and seals it, so that the large hole section between the upper cover and the piston block forms a sealed inner cavity; 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.

2. A high temperature circuit breaker self-protection pressure transmitter as claimed in claim 1, characterized in that: The lower cover is divided into two half-cover bodies, left and right, by the axis, and each half-cover body retains half of the barrel body and the flange body. 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 an arc-shaped protrusion is correspondingly 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.

3. A high temperature circuit breaker self-protection pressure transmitter as claimed in claim 2, characterized in that: The wall thickness of the barrel of the lower cover is relatively thin, and can be slightly deformed when squeezed by the piston.

4. A high temperature circuit breaker self-protection pressure transmitter as claimed in claim 1, characterized in that: A piston positioning key is formed on the step surface to assist in fool-proof positioning of the piston when installing the piston.

5. A high temperature circuit breaker self-protection pressure transmitter as claimed in claim 1, characterized in that: 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.

6. A high temperature circuit breaker self-protection pressure transmitter as claimed in claim 5, characterized in that: The bottoms of the two springs are respectively placed in corresponding spring placement holes opened on the step surface of the case.

7. A high temperature circuit breaker self-protection pressure transmitter as claimed in claim 1, characterized in that: The power circuit board is fixedly installed below the upper table cover.

8. A high temperature circuit breaker self-protection pressure transmitter as claimed in claim 1, characterized in that: 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. The second flexible circuit board is soldered to the second pin socket to achieve electrical connection between the electrical plug and the power circuit board.

9. A high temperature circuit breaker self-protection pressure transmitter as claimed in 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, and a third O-ring is compressed between the pressure-sensitive element locking nut and the watch case to ensure sealing, and the first flexible circuit board is connected to the first pin socket with soldering to complete the connection between the pressure-sensitive element and the signal circuit board.

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