Explosion-proof intrinsically-safe frequency conversion speed regulation control box for conveyor

Abstract

The invention discloses an explosion-proof intrinsically-safe variable-frequency speed regulation control box for a conveyor, and relates to the technical field of conveyor control boxes, the explosion-proof intrinsically-safe variable-frequency speed regulation control box comprises a control chip U1 and a variable-frequency driving unit Drive, an output pin of the control chip U1 is coupled with an input end of the variable-frequency driving unit Drive, a signal input end of the control chip U1 is respectively coupled with resistors R1, R3 and R5, the resistor R1 is grounded through a capacitor C2, and the resistor R2 is grounded through a capacitor C2. The resistor R3 is grounded through a capacitor C3, the resistor R5 is grounded through a capacitor C4, and the resistor R1 is coupled with a bidirectional diode D1 after being connected with a resistor R2 in series. The variable-frequency speed regulation circuit has the advantages that six paths of driving signals are output to the variable-frequency driving unit Drive through output pins 33-38 of the control chip, the variable-frequency driving unit Drive drives the direct-current motor M to work, the rotating speed of the direct-current motor M is changed, and variable-frequency speed regulation is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of control boxes, in particular to an explosion-proof intrinsically safe variable frequency speed regulation control box for a conveyor. Background Art

[0002] The flameproof intrinsically safe variable frequency speed control box of the conveyor is an electrical device used to control the speed of the conveyor motor. It is mainly used in dangerous environments with explosive gases and dust such as underground coal mines. The existing variable frequency speed control box for conveyors has an overload protection function during use. However, in some special cases, such as when the conveyor suddenly encounters a large accumulation of materials, the control box cannot adjust the speed of the DC motor of the conveyor in time, and thus needs to withstand the overload current for a long time. If the overload lasts too long, the control box may be damaged and even cause a safety accident. Therefore, we propose an explosion-proof intrinsically safe variable frequency speed control box for conveyors to solve the above problems. Summary of the invention

[0003] The object of the present invention is to provide a flameproof intrinsically safe variable frequency speed control box for a conveyor.

[0004] To achieve the above object, the present invention provides the following technical solution: an explosion-proof intrinsically safe variable frequency speed control box for a conveyor, comprising a control chip U1 and a variable frequency drive unit Drive, wherein the output pin of the control chip U1 is coupled to the input end of the variable frequency drive unit Drive, the signal input end of the control chip U1 is respectively coupled to resistors R1, R3 and R5, the resistor R1 is grounded via a capacitor C2, the resistor R3 is grounded via a capacitor C3, and the resistor R5 is grounded via a capacitor C4; The resistor R1 is connected in series with the resistor R2 and then coupled with a bidirectional diode D1; the resistor R3 is connected in series with the resistor R4 and then coupled with a bidirectional diode D2; the resistor R5 is connected in series with the resistor R6 and then coupled with a bidirectional diode D3; The resistors R2, R4 and R6 are commonly coupled to the connector CN1, the resistor R2 is coupled to the first terminal of the connector CN1, the resistor R4 is coupled to the second terminal of the connector CN1, the resistor R6 is coupled to the third terminal of the connector CN1, and the signal input ends of the first terminal, the second terminal and the third terminal of the connector CN1 are coupled to the DC motor M; The signal input end of the DC motor M is coupled to a connector CN2, and the signal input end of the connector CN2 is coupled to the signal output end of the variable frequency drive unit; As a further solution of the present invention: the variable frequency drive unit includes a transistor M1 and a control module U2, and a pin No. 1 of the control module U2 is coupled to the base terminal of the transistor M1 via a resistor R10; As a further solution of the present invention: a diode D6 is connected in parallel between the emitter and collector of the transistor M1, the anode of the diode D6 is coupled to a capacitor C5, the capacitor C5 is coupled to the cathode of the diode D6 via a resistor R8, both ends of the resistor R8 are connected in parallel to the diode D5, the emitter of the transistor M1 is coupled to a resistor R7, and the collector of the transistor M1 is coupled to a load resistor R9; As a further solution of the present invention: a capacitor C8 is commonly coupled between the pin No. 2 and the pin No. 4 of the control module U2; As a further solution of the present invention: the pin 12 of the control module U2 is coupled to a capacitor C9 via a resistor R13, the two ends of the resistor R13 are connected in parallel to a capacitor C6, and the pin 12 of the control module U2 is also coupled to a resistor R14; As a further solution of the present invention: the thirteenth pin of the control module U2 is coupled to the collector end of the transistor M1 via the diode D4; As a further solution of the present invention: the 15th pin of the control module U2 is coupled between the resistor R13 and the capacitor C9 via the resistor R12; As a further solution of the present invention: the eighth pin of the control module U2 is coupled to a capacitor C7, and the seventh pin of the control module U2 is coupled to a resistor R11.

[0005] By adopting the above technical solution, compared with the prior art, the beneficial effects of the present invention are: 1. The present invention outputs six-way driving signals to the variable frequency drive unit Drive through the output pins 33-38 of the control chip, and the variable frequency drive unit Drive drives the DC motor M to work. In addition to adopting the three-star structure and bridge drive, the DC motor M is also provided with three Hall sensor components H1-H3 inside, so that there are six combinations of the output states of the three Hall sensor components, as shown in Table 1. In the process of transmitting the output state signals of the three Hall sensor components to the control chip U1 through the connector CN1, the signals are subjected to upper and lower bidirectional amplitude limiting by the dual diodes D1-D3, current limiting by R1-R6 and high-frequency filtering by C2-C7, and then added to the input pins 40-42 of the control chip U1 of the control chip. After being recognized and processed by the control chip U1, the driving signals are output in pairs in turn according to the pre-stored working program in the order of U+ / V-→U+ / W-V+ / W-→V+ / U-→W+ / U-→W+ / V-, and then a conduction loop is formed through the winding of the DC motor M, and a rotating magnetic field is generated at the same time, and the motor rotor rotates under the action of the magnetic field; 2. When the duty cycle of the PWM drive signal output by the 33-38 pins of the control chip U1 of the present invention changes, the fourth pin of the variable control module U2 is connected to a low level to select the pulse control mode, and the pulse from the pulse transformer is added to the control end of the fifth pin, which is adjusted by the internal logic processor through the input interface, and the corresponding positive drive current is output by the sixteenth pin. This current flows into the base circuit of the transistor M1, and the transistor M1 is turned on, and the corresponding adjustment signal is output to the DC motor M through the emitter, so that the speed of the DC motor M can be changed to realize variable frequency speed regulation.

[0006] Other advantages, objectives and features of the present invention will be set forth in part in the following description and, in part, will be apparent to those skilled in the art based on an examination of the following or may be taught from the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 It is a schematic diagram of the circuit structure of the present invention; Figure 2 It is a circuit diagram of the variable frequency drive unit Drive in the present invention. DETAILED DESCRIPTION

[0008] The specific embodiments of the present invention will be further described below in conjunction with the accompanying drawings. It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention.

[0009] In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0010] Example

[0011] Please refer to the attached Figure 1 -Attached Figure 2The present invention discloses an explosion-proof intrinsically safe variable frequency speed control box for a conveyor, which solves the problem that "although the existing variable frequency speed control box for conveyors has an overload protection function during use, in some special cases, such as when the conveyor suddenly encounters a large accumulation of materials, the control box cannot adjust the speed of the DC motor of the conveyor in time, and thus needs to withstand the overload current for a long time. If the overload lasts too long, the control box may be damaged or even cause a safety accident." The invention comprises a control chip U1 and a variable frequency drive unit Drive, wherein the output pin of the control chip U1 is coupled to the input end of the variable frequency drive unit Drive, and the signal input end of the control chip U1 is coupled to resistors R1, R3 and R5 respectively, and the resistor R1 is connected to the capacitor C2 via the capacitor C3. grounded, resistor R3 is grounded via capacitor C3, resistor R5 is grounded via capacitor C4, resistor R1 is connected in series with resistor R2 and then coupled with bidirectional diode D1, resistor R3 is connected in series with resistor R4 and then coupled with bidirectional diode D2, resistor R5 is connected in series with resistor R6 and then coupled with bidirectional diode D3, resistors R2, R4 and R6 are commonly coupled with connector CN1, resistor R2 is coupled to terminal No. 1 of connector CN1, resistor R4 is coupled to terminal No. 2 of connector CN1, resistor R6 is coupled to terminal No. 3 of connector CN1, signal input ends of terminal No. 1, terminal No. 2 and terminal No. 3 of connector CN1 are coupled with DC motor M, signal input end of DC motor M is coupled with connector CN2, signal input end of connector CN2 is coupled to signal output end of variable frequency drive unit; For details, please refer to the attached Figure 1The output pins 33-38 of the control chip output six drive signals to the variable frequency drive unit Drive. The variable frequency drive unit Drive drives the DC motor M to work. In addition to the Samsung structure and bridge drive, the DC motor M also has three Hall sensor components H1-H3 inside. Their spatial angle is 120° electrical angle. When the rotor rotates, it outputs PG phase detection signals separated by 120° in sequence. When the detection signal is 0, it is disconnected, and when the detection signal is 1, it is turned on. Each component is turned on for 180° at a time. Therefore, the output state of a component changes every 60°. In this way, there are 6 combinations of the output states of the three Hall sensor components, as shown in Table 1. In the process of transmitting the output state signals of the three Hall sensor components to the control chip U1 through the connector CN1, the signals are bidirectionally connected up and down by the dual diodes D1-D3. After amplitude limiting, current limiting by R1-R6 and high-frequency filtering by C2-C7, the signals are added to the input pins 40-42 of the control chip U1 of the control chip. After being identified and processed by the control chip U1, the drive signals are output in pairs in the order of U+ / V-→U+ / W-V+ / W-→V+ / U-→W+ / U-→W+ / V- according to the pre-stored working procedure. Then, a conduction loop is formed through the DC motor M winding, and a rotating magnetic field is generated at the same time. Under the action of the magnetic field, the motor rotor rotates. When the duty cycle of the PWM drive signal output by the 33-38 pins of the control chip U1 changes, the speed of the DC motor M can be changed to realize variable frequency speed regulation. Once the PG pulse signal output by the 40-42 input pins of the control chip U1 is missing, that is, 0, the output pins 33-38 of the control chip U1 will have no PWM drive signal output, and the variable frequency drive unit will no longer work. Table 1

[0012] Specifically, the variable frequency drive unit includes a transistor M1 and a control module U2, and a pin No. 1 of the control module U2 is coupled to the base terminal of the transistor M1 via a resistor R10; The model of the control module U2 is UAA4002, which is a 16-pin double-row plug-in integrated circuit. It can realize the optimal base drive of the transistor M1 and realize the centralized protection of the transistor M1. Specifically, it converts the electric energy information received as a logic signal input into the base current added to the transistor M1. This base current can be automatically adjusted to ensure that the transistor M1 is always in a quasi-saturation state. The maximum current output by the control module U2 is 0.5A, and the maximum reverse base current is 3A, which ensures that the transistor M1 is quickly turned off; Among them, pin 1 is the output base driving negative current, pin 2 is the negative power supply, pin 3 is the output blocking, pin 4 is the control method selection, pin 5 is the control terminal, pin 6 is the negative power supply monitoring time resistor, pin 7 is the minimum on-time resistor to determine the minimum on-time resistor R11, pin 8 is to determine the minimum on-time capacitor C7, pin 9 is the ground terminal GND, pin 10 is the input and output leading edge delay resistor, pin 11 is the voltage monitoring terminal, pin 12 is the collector current monitoring terminal, pin 13 is the voltage detection terminal, pins 14 and 15 are the power stage positive power supplies, and pin 16 is the output base driving positive current; A diode D6 is connected in parallel between the emitter and collector of the transistor M1, the anode of the diode D6 is coupled to a capacitor C5, the capacitor C5 is coupled to the cathode of the diode D6 via a resistor R8, both ends of the resistor R8 are connected in parallel to the diode D5, the emitter of the transistor M1 is coupled to a resistor R7, and the collector of the transistor M1 is coupled to a load resistor R9; A capacitor C8 is commonly coupled between the pin No. 2 and the pin No. 4 of the control module U2, a capacitor C9 is coupled to the pin No. 12 of the control module U2 via a resistor R13, a capacitor C6 is connected to both ends of the resistor R13, a resistor R14 is also coupled to the pin No. 12 of the control module U2, a collector terminal of the transistor M1 is coupled to the pin No. 13 of the control module U2 via a diode D4, a capacitor C7 is coupled to the pin No. 8 of the control module U2, and a resistor R11 is coupled to the pin No. 7 of the control module U2; Specifically, when the duty cycle of the PWM drive signal output by the 33-38 pins of the control chip U1 changes, the fourth pin of the variable control module U2 is connected to a low level to select the pulse control mode, and the pulse from the pulse transformer is added to the control end of the fifth pin, and is adjusted by the internal logic processor through the input interface, and the corresponding positive drive current is output by the sixteenth pin. This current flows into the base circuit of the transistor M1, and the transistor M1 is turned on, and the corresponding adjustment signal is output to the DC motor M through the emitter; When the negative power supply voltage V of the second pin of the control module U2 is added to the base of the transistor M1, a high negative base current is generated, causing the transistor M1 to be quickly turned off.

[0013] The above-mentioned front, back, left, right, top and bottom are all based on the figures in the specification. Figure 1 As a benchmark.

[0014] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the scope of protection of the present invention.

[0015] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the described embodiments.

[0016] It is apparent to those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the invention, and the changes still fall within the protection scope of the invention.

Claims

1. The explosion-proof intrinsically safe variable frequency speed control box for conveyors includes a control chip U1 and a variable frequency drive unit Drive, and is characterized by: The output pin of the control chip U1 is coupled to the input end of the variable frequency drive unit Drive, and the signal input end of the control chip U1 is respectively coupled to resistors R1, R3 and R5, the resistor R1 is grounded via the capacitor C2, the resistor R3 is grounded via the capacitor C3, and the resistor R5 is grounded via the capacitor C4; The resistor R1 is connected in series with the resistor R2 and then coupled with a bidirectional diode D1; the resistor R3 is connected in series with the resistor R4 and then coupled with a bidirectional diode D2; the resistor R5 is connected in series with the resistor R6 and then coupled with a bidirectional diode D3; The resistors R2, R4 and R6 are commonly coupled to the connector CN1, the resistor R2 is coupled to the first terminal of the connector CN1, the resistor R4 is coupled to the second terminal of the connector CN1, the resistor R6 is coupled to the third terminal of the connector CN1, and the signal input ends of the first terminal, the second terminal and the third terminal of the connector CN1 are coupled to the DC motor M; The signal input end of the DC motor M is coupled to a connector CN2, and the signal input end of the connector CN2 is coupled to a signal output end of the variable frequency drive unit.

2. The flameproof intrinsically safe variable frequency speed control box for conveyors according to claim 1 is characterized in that: The variable frequency drive unit includes a transistor M1 and a control module U2 , and a pin No. 1 of the control module U2 is coupled to the base terminal of the transistor M1 via a resistor R10 .

3. The flameproof intrinsically safe variable frequency speed control box for conveyors according to claim 2 is characterized in that: A diode D6 is connected in parallel between the emitter and collector of the transistor M1, the anode of the diode D6 is coupled to a capacitor C5, the capacitor C5 is coupled to the cathode of the diode D6 via a resistor R8, both ends of the resistor R8 are connected in parallel with a diode D5, the emitter of the transistor M1 is coupled to a resistor R7, and the collector of the transistor M1 is coupled to a load resistor R9.

4. The flameproof intrinsically safe variable frequency speed control box for conveyors according to claim 3 is characterized in that: A capacitor C8 is commonly coupled between the second pin and the fourth pin of the control module U2 .

5. The flameproof intrinsically safe variable frequency speed control box for conveyors according to claim 4 is characterized in that: The twelfth pin of the control module U2 is coupled to the capacitor C9 via the resistor R13. The two ends of the resistor R13 are connected in parallel to the capacitor C6. The twelfth pin of the control module U2 is also coupled to the resistor R14.

6. The flameproof intrinsically safe variable frequency speed control box for conveyors according to claim 5 is characterized in that: The thirteenth pin of the control module U2 is coupled to the collector terminal of the transistor M1 via the diode D4.

7. The flameproof intrinsically safe variable frequency speed control box for conveyors according to claim 6 is characterized in that: The fifteenth pin of the control module U2 is coupled between the resistor R13 and the capacitor C9 via the resistor R12 .

8. The flameproof intrinsically safe variable frequency speed control box for conveyors according to claim 7 is characterized in that: The eighth pin of the control module U2 is coupled to a capacitor C7 , and the seventh pin of the control module U2 is coupled to a resistor R11 .

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