Explosion-proof box with multifunctional magnetic control keys

Abstract

The utility model relates to the technical field of explosion-proof boxes, in particular to an explosion-proof box with a multifunctional magnetic control key, which comprises an explosion-proof box body, an explosion-proof box upper cover connected to the explosion-proof box body, a magnetic induction chip located in the explosion-proof box body, and a button assembly arranged in the explosion-proof box body. The button assembly is arranged on the explosion-proof box upper cover, the button assembly comprises a magnet which is arranged corresponding to the magnetic induction chip and is in magnetic induction fit with the magnetic induction chip, and the magnet can move towards or away from the magnetic induction chip; and the differential pressure shaping circuit is connected with the magnetic induction chip and is used for shaping the waveform delay of the output voltage of the driving circuit caused by hysteresis. The magnetic induction button structure is arranged outside the explosion-proof box, so that holes are prevented from being formed in the box body of the explosion-proof box, and the safety of the explosion-proof box is improved.

Description

Technical Field

[0001] This application relates to the field of explosion-proof box technology, and in particular to an explosion-proof box with a multi-functional magnetic control button. Background Technology

[0002] Due to the special safety requirements of explosion-proof enclosures, they must be certified separately for explosion protection. Existing explosion-proof enclosures have buttons installed on them, which require drilling holes in the enclosure lid. This inevitably creates gaps at the joint between the buttons and the lid, affecting the explosion-proof sealing performance and increasing the difficulty of overall explosion-proof certification.

[0003] With the development of the intelligent manufacturing industry, many devices have complex functions, requiring a large number of buttons. However, this increased number of buttons also increases the number of openings in the explosion-proof enclosure, further affecting the explosion-proof sealing performance. For high-level gas and dust explosion protection, certification may not meet the requirements. Traditional explosion-proof buttons are relatively large and unsuitable for operating intelligent weighing instruments. Using small mechanical buttons will not pass explosion-proof certification. Utility Model Content

[0004] The technical problem this invention aims to solve is that existing multi-button explosion-proof boxes have many gaps, making it difficult to meet explosion-proof standards.

[0005] Therefore, this utility model provides an explosion-proof box with a multi-functional magnetic control button.

[0006] The technical solution adopted by this utility model to solve its technical problem is:

[0007] A multi-functional magnetic control button explosion-proof box, comprising,

[0008] The explosion-proof box itself, and,

[0009] The explosion-proof box cover is connected to the explosion-proof box body.

[0010] A magnetic induction chip is located inside the explosion-proof enclosure.

[0011] A button assembly is disposed on the top cover of the explosion-proof box. The button assembly includes a magnet that is correspondingly disposed and magnetically engaged with the magnetic induction chip. The magnet is capable of moving toward or away from the magnetic induction chip.

[0012] A differential pressure shaping circuit, which is connected to a magnetic induction chip, is used to shape the delay in the output voltage waveform of the drive circuit caused by hysteresis.

[0013] Furthermore, the explosion-proof box cover has a mounting groove on the side wall away from the explosion-proof box body, and the button assembly has a mounting groove on the mounting plate.

[0014] Furthermore, the explosion-proof box contains a magnetic control PCB board for mounting a magnetic induction chip, which is connected by studs.

[0015] Furthermore, it also includes a magnetic shielding component, which enables the magnetic induction chip to receive only the magnetic field of its corresponding magnet.

[0016] Furthermore, the magnetic shielding assembly includes a magnetic shielding sleeve, which is fitted onto the magnet. The magnetic shielding sleeve is tubular and shields the magnetic field emitted from around the magnet while retaining the magnetic field emitted by the magnet toward the magnetic induction chip.

[0017] Furthermore, the magnetic shielding assembly also includes a magnetic shielding cover, which is placed on the magnetic induction chip. The magnetic shielding cover is used to shield the magnetic field from the surrounding magnetic field of the magnetic induction chip, so that the magnetic induction chip only receives the magnetic field from the direction of the magnet.

[0018] Furthermore, the button assembly also includes a seat, a spring, and a push rod. The seat is fixedly connected to the outside of the explosion-proof box via a mounting plate. The push rod passes through the seat. The spring is sleeved on the push rod and positioned between the seat and the push rod for the push rod to reset. The magnet is positioned on the end of the push rod facing the explosion-proof box.

[0019] Furthermore, multiple button assemblies and magnetic induction chips are provided, with one button assembly corresponding to one magnetic induction chip, and multiple differential pressure shaping circuits corresponding to each magnetic induction chip are provided on the magnetic control PCB board.

[0020] Furthermore, the magnetic control PCB board is also equipped with an amplifier, a low-pass filter, and a driver, and the magnetic induction chip, amplifier, low-pass filter, driver, and differential pressure shaping circuit are connected in sequence.

[0021] The beneficial effects of this utility model are as follows: By setting a magnetic induction button structure on the outside of the explosion-proof box, this application avoids opening holes in the explosion-proof box body, thereby improving the safety of the explosion-proof box; on this basis, due to the setting of multiple buttons, a magnetic shielding sleeve, a magnetic shielding cover, and a differential pressure shaping circuit are added. The magnetic shielding sleeve and the magnetic shielding cover provide bidirectional magnetic shielding from the transmitting end and the receiving end, respectively, improving the directionality of magnetic field transmission, thereby avoiding mutual interference between the magnetic fields of the magnetic control buttons in the multi-button structure and improving the operating accuracy of the magnetic control buttons; the delay in the output voltage waveform of the drive circuit caused by hysteresis is reduced to the nanosecond level after differential pressure shaping, which can meet the requirements of real-time button control and greatly improve the reliability of real-time button control. Attached Figure Description

[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0023] Figure 1This is a structural schematic diagram of the explosion-proof box with multi-functional magnetic control buttons in this utility model.

[0024] Figure 2 This is a schematic diagram of the installation structure of the button assembly in this utility model.

[0025] Figure 3 This is a structural schematic diagram showing the positional relationship between the magnet and the magnetic induction chip in this utility model.

[0026] Figure 4 This is a schematic diagram showing the connection relationship between the magnetic induction chip and the differential pressure shaping circuit in this utility model.

[0027] Figure 5 This is a schematic diagram of the differential pressure shaping circuit in this utility model.

[0028] In the diagram: 1. Explosion-proof box body; 11. Explosion-proof box top cover; 12. Mounting slot; 13. Mounting plate; 2. Button assembly; 21. Seat sleeve; 22. Limiting plate; 23. Nut; 24. Spring; 25. Top rod; 26. Magnet; 27. Screw; 28. Snap ring; 3. Magnetic induction chip; 4. Magnetic control PCB board; 41. Amplifier; 42. Low-pass filter; 43. Drive circuit; 44. Differential pressure shaping circuit; 5. Stud; 6. Magnetic shielding assembly; 61. Magnetic shielding sleeve; 62. Magnetic shielding cover. Detailed Implementation

[0029] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, illustrating only the basic structure of the present invention, and therefore only show the components relevant to the present invention.

[0030] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "transverse," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., indicating the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, features defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0031] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0032] An explosion-proof box with a multi-functional magnetic control button includes an explosion-proof box body 1, an explosion-proof box cover 11, and a button assembly 2. The explosion-proof box cover 11 is seamlessly connected to the explosion-proof box body 1. The explosion-proof box cover 11 is provided with a mounting groove 12, and a mounting plate 13 for covering the mounting groove 12 and mounting the button assembly 2 is bolted to the explosion-proof box cover 11.

[0033] The button assembly 2 includes a seat 21, a push rod 25, a spring 24, a magnet 26, and a nut 23. One end of the seat 21 is connected to a limit ring. The outer side wall of the seat 21 is threaded. The seat 21 extends through the mounting plate 13 into the mounting groove 12. The limit ring abuts against the side wall of the mounting plate 13 away from the bottom of the mounting groove 12. The nut 23 is threadedly connected to the end of the seat 21 located in the mounting groove 12. The nut 23 engages with the thread on the outer side wall of the seat 21 until the nut 23 abuts against the mounting plate 13. The limit ring and the nut 23 fix the seat 21 to the mounting plate 13.

[0034] Spring 24 is installed inside seat sleeve 21. Push rod 25 passes through spring 24. One end of spring 24 near the bottom of mounting groove 12 is fixedly connected to the inner side wall of seat sleeve 21, and the other end abuts against the head of push rod 25. Push rod 25 protrudes from one end of seat sleeve 21 located in mounting groove 12. Magnet 26 is threadedly fastened to one end of push rod 25 located in mounting groove 12 by screw 27. Magnet 26 is provided with a through hole for screw 27 to pass through. Snap ring 28 is provided between magnet 26 and end of seat sleeve 21.

[0035] Inside the explosion-proof box, a magnetic control PCB board 4 is installed by studs 5. A magnetic induction chip 3 corresponding to the magnet 26 is provided on the magnetic control PCB board 4. In this embodiment, the magnetic induction chip 3 is arranged directly below the corresponding magnet 26 along the axial direction of the seat sleeve 21.

[0036] It should be noted that, in order to accommodate the control of intelligent devices, and given the numerous functions required by these devices, the corresponding mounting plate 13 is equipped with multiple button assemblies 2. The magnet 26 in each button assembly 2 is positioned opposite to the corresponding magnetic induction chip 3. Due to the large number of button assemblies 2, the distance between them is reduced. To avoid opening holes in the explosion-proof box, a non-contact button is designed based on the magnetic field interaction between the magnet 26 and the magnetic induction chip 3. The magnet 26 forms an arc-shaped magnetic field radiating outwards and backwards with the axial direction of the base sleeve 21 as its centerline. For adjacent button assemblies 2 with limited installation distance, there is cross-magnetic field interference. During normal button operation, this may lead to button malfunction or misoperation. Therefore, to avoid magnetic induction interference between adjacent button assemblies 2, the explosion-proof box for the multi-functional magnetic control button in this application also includes a magnetic shielding assembly 6.

[0037] The magnetic shielding assembly 6 includes a magnetic shielding sleeve 61 and a magnetic shielding cover 62. Both the magnetic shielding sleeve 61 and the magnetic shielding cover 62 are made of tin-plated tinplate. The magnetic shielding sleeve 61 is tubular and fits onto the base sleeve 21, with the magnet 26 located inside the magnetic shielding sleeve 61. The magnetic shielding cover 62 is an open fence-like structure that covers the magnetic induction chip 3. The magnetic shielding sleeve 61 shields the scattered magnetic field around the magnet 26, retaining a unidirectional downward magnetic field at the bottom of the button, thereby achieving directional magnetic induction between the magnet 26 and the corresponding magnetic induction chip 3, and solving the problem of cross-magnetic field interference between adjacent buttons. The practicality and reliability of the magnetic control button operation are improved.

[0038] Furthermore, the magnetic induction chip 3 exhibits hysteresis characteristics. When a button is pressed and a strong magnetic field is sensed, there is a delay in the output level changing from high to low before the button can enter the "on" state. When the button is released and the magnetic field disappears, again due to the chip's hysteresis, there is a delay before the button can enter the "off" state. This could potentially cause the control instrument to unreliably execute its control functions.

[0039] To avoid this reliability issue, a differential pressure shaping circuit 44 is added to the magnetic control PCB board 4. This circuit shapes the output voltage waveform delay caused by hysteresis in the drive circuit 43. The output signal delay time is in the nanosecond (NS) range, which meets the requirements of real-time button control and further improves the reliability of button operation. The magnetic control PCB board 4 also includes an amplifier 41, a low-pass filter 42, and a drive circuit 43. The magnetic induction chip 3, amplifier 41, low-pass filter 42, drive circuit 43, and differential pressure shaping circuit 44 are connected sequentially.

[0040] The differential voltage shaping circuit 44 in this embodiment includes a first transistor Q1, a second transistor Q2, and a third transistor Q3. The emitter of the first transistor Q1 is connected to a resistor R5, the other end of which is grounded. The collector and base of the second transistor Q2 are both connected to the collector of the first transistor Q1, and the emitter of the second transistor Q2 is connected to the emitter of the first transistor Q1. The collector and base of the third transistor Q3 are both connected to the collector of the second transistor Q2, and the emitter of the third transistor Q3 is grounded. Therefore, the hysteresis causes a delay in the output voltage waveform of the drive circuit 43. After differential voltage shaping, the output signal delay time is on the nanosecond level, which can meet the requirements of real-time button control and greatly improve the reliability of real-time button control.

[0041] Specifically, using integrated chips (e.g., operational amplifiers, comparators) for large differential pressure adjustment is quite difficult; using operational amplifiers with a single power supply results in an output signal level of 0 at 1 / 2VCC, and the shaped waveform is ±1 / 2VCC, which is not suitable for control instrument buttons; using comparators, large differential pressure cannot be adjusted; this differential pressure adjustment uses a discrete transistor circuit. For the output voltage of driver 7, it rises from OL to V+ (opening threshold) to achieve V+>2V, which can adjust the collector current of the first transistor Q1 (3.3V-VR5 / R2) and the first transistor... The base current of transistor Q1 (2V-0.6V / R1) decreases from VOH to V- (off threshold) for the output voltage of driver 7, achieving V- < 1.5V. This allows adjustment of the collector current of transistor Q2 (3.3V-VR5 / R3) and the base current of transistor Q2 (2V-0.6V / R8). Adjusting the resistance of R5 in the circuit adjusts V+ (on threshold), and adjusting the resistance of R3 in the circuit adjusts V- (off threshold). This delay shaping circuit allows for flexible and convenient adjustment of the differential voltage required by the system.

[0042] In this embodiment, the delay shaping circuit further includes resistors R1, R3, R7, R10, R4, R6, R8, and R9. The base of the first transistor Q1 is connected to one end of resistor R1, one end of resistor R3 is connected to the collector of the first transistor Q1, one end of resistor R7 is connected to the collector of the second transistor Q2, one end of resistor R10 is connected to the collector of the third transistor Q3, and the other ends of resistors R3, R7, and R10 are all connected to resistor R9. The transistors are connected to a 0.3V power supply. Resistor R4 is connected to the collector of transistor Q1 and the base of transistor Q2, respectively. One end of resistor R6 is connected to the base of transistor Q2, and the other end is grounded. Resistor R8 is connected to the collector of transistor Q2 and the base of transistor Q3, respectively. One end of resistor R9 is connected to the base of transistor Q3, and the other end is grounded. Transistors Q1, Q2, and Q3 are all model 2N3904.

[0043] The differential pressure shaping circuit 44 works as follows: The magnetic hysteresis loop of the magnetic induction chip 3 causes a differential pressure between the driver output: V+ and V-. When the output of the magnetic induction chip 3 is within the time interval t0-t1, the input signal < V+, the first transistor Q1 is cut off, and the output is high-level. The second transistor Q2 is turned on, and the current at the collector (c) of the second transistor Q2 flows into the resistor R5, generating a voltage drop. This causes the emitter (e) of the first transistor Q1 to be reverse-biased, resulting in positive feedback, which further turns off the first transistor Q1. The collector (c) of the second transistor Q2 outputs a low-level voltage, and the base of the third transistor Q3... When there is no current at electrode b, the third transistor Q3 is cut off, and its collector c outputs a high level. When the input signal > V+, the first transistor Q1 is turned on, and its collector c outputs a low level. The voltage drop generated by the collector current of the first transistor Q1 through resistor R5 reverses the emitter e of the second transistor Q2, causing positive feedback and further cutting off the second transistor Q2. The collector c of the second transistor Q2 outputs a high level, resulting in a bias current at the base of the third transistor Q3, and the collector c of the third transistor Q3 outputs a low level. Based on the above-described ideal embodiment of this utility model, and through the above description, those skilled in the art can make various changes and modifications without departing from the technical concept of this utility model. The technical scope of this utility model is not limited to the contents of the specification, but must be determined by the scope of the claims.

Claims

1. An explosion-proof box with a multi-functional magnetic control button, characterized in that, include, The explosion-proof box body (1), and, The explosion-proof box cover (11) is connected to the explosion-proof box body (1); Magnetic induction chip (3), the magnetic induction chip (3) is located inside the explosion-proof box body (1); Button assembly (2), the button assembly (2) is disposed on the explosion-proof box cover (11), the button assembly (2) includes a magnet (26) corresponding to and magnetically cooperating with the magnetic induction chip (3), the magnet (26) can move toward or away from the magnetic induction chip (3); Differential pressure shaping circuit (44), which is connected to magnetic induction chip (3), is used to shape the delay of the output voltage waveform of drive circuit (43) caused by hysteresis.

2. The explosion-proof box with multi-functional magnetic control buttons according to claim 1, characterized in that, The explosion-proof box cover (11) has an installation groove (12) on the side wall away from the explosion-proof box body (1), and the button assembly (2) has an installation groove (12) on the mounting plate (13).

3. The explosion-proof box with multi-functional magnetic control buttons according to claim 1, characterized in that, The explosion-proof box contains a magnetic control PCB board (4) for mounting a magnetic induction chip (3) connected by studs (5).

4. The explosion-proof box with multi-functional magnetic control buttons according to claim 1, characterized in that, It also includes a magnetic shielding component (6), which enables the magnetic induction chip (3) to receive only the magnetic field of its corresponding magnet (26).

5. The explosion-proof box with multi-functional magnetic control buttons according to claim 4, characterized in that, The magnetic shielding assembly (6) includes a magnetic shielding sleeve (61), which is fitted onto the magnet (26). The magnetic shielding sleeve (61) is tubular and shields the magnetic field emitted around the magnet (26) while retaining the magnetic field emitted by the magnet (26) toward the magnetic induction chip (3).

6. The explosion-proof box with multi-functional magnetic control buttons according to claim 4, characterized in that, The magnetic shielding assembly (6) further includes a magnetic shielding cover (62), which covers the magnetic induction chip (3). The magnetic shielding cover (62) is used to shield the magnetic field from the surrounding area of ​​the magnetic induction chip (3), so that the magnetic induction chip (3) only receives the magnetic field from the direction of the magnet (26).

7. The explosion-proof box with multi-functional magnetic control buttons according to claim 3, characterized in that, The button assembly (2) also includes a seat (21), a spring (24) and a push rod (25). The seat (21) is fixedly connected to the outside of the explosion-proof box by a mounting plate (13). The push rod (25) passes through the seat (21). The spring (24) is sleeved on the push rod (25) and is set between the seat (21) and the push rod (25) for the reset of the push rod (25). The magnet (26) is set on the end of the push rod (25) facing the explosion-proof box.

8. The explosion-proof box with multi-functional magnetic control buttons according to claim 7, characterized in that, Multiple button components (2) and magnetic induction chips (3) are provided. One button component (2) corresponds to one magnetic induction chip (3). Multiple differential pressure shaping circuits (44) corresponding to each magnetic induction chip (3) are provided on the magnetic control PCB board (4).

9. The explosion-proof box with multi-functional magnetic control buttons according to claim 3, characterized in that, The magnetic control PCB board (4) is also provided with an amplifier (41), a low-pass filter (42) and a driver. The magnetic induction chip (3), amplifier (41), low-pass filter (42), driver and differential pressure shaping circuit (44) are connected in sequence.

Images