Digital display type overspeed switch

Abstract

A digital display type overspeed switch relates to the field of motor rotating speed detection and structurally comprises a rotating shaft, a main circuit board, a nixie tube, a shell and a base. The shell and the base are fixedly connected to form a cavity; the rotating shaft is arranged at the central axis position of the base, and one end of the rotating shaft extends into the cavity; the magnetic ring is fixed on the end part of one end, arranged in the cavity, of the rotating shaft; and the main circuit board is provided with a magnetic coding chip, and the magnetic coding chip is arranged right below the magnetic ring. According to the utility model, the built-in magnetic ring is adopted, so that the installation process is quicker and more convenient, and the accuracy of rotating speed detection is improved. Meanwhile, the detection circuit comprising the high-speed magnetic coding chip is adopted, compared with a traditional overspeed switch, the signal delay is lower, and the rotating speed condition of the motor can be reflected more accurately and timely.

Description

TECHNICAL FIELD

[0001] The utility model relates to motor rotating speed detection field, concretely relates to a digital display type overspeed switch. BACKGROUND

[0002] Overspeed switch, generally for motor rotating speed detection, for heavy machinery speed limiting, can stop the work of motor in time after the motor exceeds the set rotating speed, its to overspeed limit function. Early overspeed switch mostly adopts mechanical setting, overspeed switch rotates with motor, when the rotating speed of motor reaches the action value of overspeed switch, bolt cap is under the action of self centrifugal force, and radial movement through compression spring hits its arc elastic contact, thereby making overspeed switch disconnect.

[0003] And with the development of the times, the existing overspeed switch starts to adopt the cooperation of hall switch and magnetic disk, utilizes the rotation of magnetic disk driven by motor, and then judges whether overspeed through hall switch to detect the rotating speed of magnetic disk. But the existing overspeed switch is mostly set separately with magnetic disk, and the magnetic disk is exposed to external environment when working, which not only makes the installation of overspeed switch troublesome, but also brings interference to the detection of motor rotating speed. UTILITARIAN CONTENT

[0004] The utility model discloses a built-in magnetic ring and sets up the rotating speed detection circuit including high-speed magnetic encoding chip, integrates the magnetic ring and detection loop in the overspeed switch of one shell closure, solves the problem that traditional overspeed switch needs to set up magnetic ring separately when checking motor rotating speed.

[0005] The technical scheme adopted by the utility model is:

[0006] A digital display type overspeed switch, the structure thereof comprises:

[0007] The shell and the base are fixedly connected to form a cavity;

[0008] A rotating shaft is arranged at the central axis position of the base, and one end of the rotating shaft extends into the cavity; the rotating shaft is used to be connected with the rotating shaft of a target motor;

[0009] A magnetic ring is fixed to the end portion of the end in the cavity of the rotating shaft;

[0010] A main circuit board is arranged in the cavity; the main circuit board is provided with a magnetic encoding chip, and the magnetic encoding chip is arranged directly below the magnetic ring.

[0011] The back surface of the shell is provided with an operation plate; the operation plate comprises a digital display screen, a safety indicator lamp, an alarm indicator lamp and an operation button.

[0012] The operation plate is fixedly arranged above the main circuit board, and the operation plate and the main circuit board are electrically connected through connectors.

[0013] The main circuit board comprises a main control chip, a key input circuit and a display circuit connected with the main control chip, and the main control chip is electrically connected with the magnetic encoding chip.

[0014] The operation key is electrically connected with the key input circuit, and the digital display screen, the safety indicator lamp and the alarm indicator lamp are electrically connected with the display circuit.

[0015] The cavity is also provided with a second circuit board, and the second circuit board comprises a power conversion circuit for converting external power into working power of internal circuits.

[0016] The distance between the magnetic ring and the magnetic encoding chip is between 1mm and 3mm.

[0017] The intersection between the rotating shaft and the base is provided with a bearing.

[0018] One side of the shell is provided with a wire outlet hole.

[0019] The base is provided with a mounting hole for mounting and connecting the digital display type overspeed switch with an external motor.

[0020] The beneficial effects of the utility model are as follows: by adopting the built-in magnetic ring, the utility model can be directly connected with a target motor for use without separately arranging a magnetic ring, and the step of adjusting the position of the overspeed switch is omitted during installation, so that the installation process is more rapid and convenient, the built-in structure of the magnetic ring also avoids the interference of external magnetic dust and other factors during operation, and the accuracy of the rotational speed detection is improved. Meanwhile, the utility model adopts a detection circuit comprising a high-speed magnetic encoding chip, and the signal delay of the traditional overspeed switch is lower, so that the rotational speed condition of the motor can be more accurately and timely reflected. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 It is a whole structure view of the utility model.

[0022] Figure 2 It is a front view of the utility model.

[0023] Figure 3 It is a back view of the utility model.

[0024] Figure 4 It is a split structure view of the utility model.

[0025] Figure 5 It is a cross-sectional structure view of the utility model.

[0026] Figure 6 The utility model discloses a circuit diagram of detection circuit.

[0027] Figure 7 The utility model discloses a circuit diagram of main control circuit.

[0028] Figure 8 The utility model discloses a circuit diagram of button input circuit and display circuit.

[0029] Figure 9 The utility model discloses a circuit diagram of power conversion circuit.

[0030] In the drawing: 1, shell, 11, outgoing line hole, 2, base, 21, mounting hole, 3, rotating shaft, 4, bearing, 5, magnetic ring, 6, operation plate, 61, digital display screen, 62, safety indicating lamp, 63, alarm indicating lamp, 64, operation button, 7, main circuit board, 8, second circuit board. DETAILED DESCRIPTION

[0031] The utility model will be described in detail below in combination with the drawings.

[0032] As Figures 1 to 5 A digital display type overspeed switch, including shell 1, base 2, rotating shaft 3 etc. Shell 1 and base 2 are fixedly connected by bolt, and the inside of both is equipped with cavity. Rotating shaft 3 is arranged on the axis of the center of base 2, and its inside extends to the cavity between shell 1 and base 2. Rotating shaft 3 is used to be connected with the rotating shaft of external motor. In order to make rotating shaft 3 can accurately reflect the rotating speed of the motor connected, the intersection of rotating shaft 3 and base 2 is equipped with bearing 4, and bearing 4 makes rotating shaft 3 can rotate smoothly. The end of rotating shaft 3 in the cavity is equipped with magnetic ring 5, and the midpoint of magnetic ring 5 is on the same central axis with the center of shell 1 and base 2. The other side of shell 1 is equipped with operation plate 6, and operation plate 6 is connected with main circuit board 7 in the cavity through connector.

[0033] The utility model places magnetic ring 5 in the same cavity with detection circuit, avoids the step of installing magnet when installing overspeed switch, makes the installation process more quick and convenient. The built-in structure of magnetic ring 5 also avoids the interference of external magnetic dust and other factors when running compared with external structure, improves the accuracy of rotating speed detection.

[0034] Main circuit board 7 is equipped with magnetic encoding chip for detecting the change of magnetic field, and the magnetic encoding chip is located directly below magnetic ring 5, and the spacing between the magnetic encoding chip and magnetic ring 5 is 1mm to 3mm. As the preferred embodiment of the utility model, the spacing between the magnetic encoding chip and magnetic ring 5 is 2mm.

[0035] As the preferred of the utility model, the utility model adopts the magnetic encoding chip of MT6501 type. The magnetic encoding chip MT6501 is integrated with two pairs of anisotropic magnetoresistance (AMR) sensitive elements. When the motor is running, the rotating shaft 3 connected with the motor rotating shaft also rotates at the same speed, and the magnetic ring 5 arranged at the end of the rotating shaft 3 also rotates at the same speed. When the magnetic ring 5 rotates, the magnetic field direction changes periodically, and the sensitive element is sensitive to the change of the magnetic field direction parallel to the chip surface, which generates a sine wave signal by detecting the magnetic field angle offset, and then converts the digital angle signal output through the internal signal processing circuit. Combined with the inherent pulse frequency of the chip, the number of pulses generated per rotation is divided by time to obtain the real-time rotating speed. Compared with the traditional Hall sensor chip, the magnetic encoding chip has the advantages of low error and short delay. Its signal transmission delay is as low as 2us or less, effectively improving the speed and accuracy of detection.

[0036] The operation plate 6 is provided with a digital display screen 61, an indicating lamp and an operation button 64. The digital display screen 61 is used to display the real-time rotating speed of the motor. The operation button 64 is used to adjust and set the limit speed of the overspeed switch. The indicating lamp includes a safety indicating lamp 62 and an alarm indicating lamp 63. When the motor works normally, and the rotating speed is lower than the limit speed, the safety indicating lamp 62 is on. When the motor works at overspeed, the alarm indicating lamp 63 will be on, at this time, the overspeed switch will send an overspeed signal to the actuator, and the alarm indicating lamp 63 will be off only after the motor stops rotating.

[0037] The lower end of the shell 1 is provided with a wire outlet hole 11, which is used to connect the lead wire with the external power supply assembly.

[0038] The surface of the base 2 is provided with a mounting hole 21, and the overspeed switch is fixedly arranged on the motor to be tested through the mounting hole 21, so that the position deviation of the overspeed switch relative to the motor during the rotation of the motor is avoided, and the deviation of the test result of the rotating speed is avoided.

[0039] As Figures 6 to 8The main circuit board 7 comprises a main control circuit, a detection circuit, a key input circuit and a display circuit etc. The detection circuit comprises a magnetic encoding chip, and the main control circuit comprises a main control chip. After the magnetic encoding chip obtains the magnetic field offset signal generated by the rotation of the magnetic ring 5, the magnetic encoding chip outputs the signal to the main control chip through the SWDIO interface, and simultaneously outputs the clock signal of the magnetic encoding chip to the main control chip through the SWCLK interface. The main control chip can calculate the rotation speed of the magnetic ring 5 and the target motor through the sinusoidal pulse signal obtained by the SWDIO and the frequency signal obtained by the SWCLK interface. Meanwhile, when the magnetic ring 5 starts to rotate, i.e. the motor starts to rotate, the HAL1 interface of the magnetic encoding chip also outputs a signal to the main control chip and the D2 lamp group of the display circuit, at this time, the D2 lamp group is lighted up to indicate that the target motor normally operates and the detection loop of the overspeed switch normally operates. The D2 lamp group is the safety indicator lamp 62 arranged on the operation panel 6.

[0040] The main control chip is connected with the digital display screen 61 on the operation panel 6 through the SEG11-SEG88 segment selection pins and the GRID1-GRID3 bit selection pins, so as to display the rotation speed of the target motor in real time. Meanwhile, the main control chip receives the KEY1-KEY3 signals of the key input circuit to determine the limited speed of the target motor. When the real-time rotation speed is lower than the limited speed, the overspeed switch and the target motor normally operate, at this time, the safety indicator lamp 62 keeps lighted. When the real-time rotation speed exceeds the limited speed, the main control chip sends an alarm signal and a stop signal, the alarm signal is output to the alarm indicator lamp 63, i.e. the D3 lamp group, of the operation panel through the RLY interface. The stop signal is output to the communication circuit and the external control executor through the R485, E485 and D485 interfaces, so as to send a command to make the target motor stop rotating.

[0041] In the utility model, since the main circuit board 7 is limited in space, the second circuit board 8 is arranged in the cavity formed by the combination of the shell 1 and the base 2, and the second circuit board 8 comprises a power conversion circuit for converting the external power voltage into the working voltage of the elements on the circuit board. Figure 9 , Figure 9 The lower part is an AC-DC conversion circuit, which is composed of an MB10F rectifier bridge, an electrolytic capacitor, a TMI1363 power chip and an L1 inductor, and the function thereof is to convert the 24V external alternating voltage input into 12V direct current output to provide direct current power supply for the subsequent circuit. Figure 9 The upper part is a DC-DC conversion circuit, which is composed of an LM1 power chip and an electrolytic capacitor. This part converts the 12V direct current power supply into 5V direct current power supply to supply power for other components with a voltage requirement of 5V, such as the main control chip.

[0042] The above describes the specific structural features, the use method and the advantages of the present application. It should be noted that the specific implementation of the present application is not limited by the above method, as long as various non-essential improvements are made by using the technical scheme of the present application, or the concept and technical scheme of the present application are directly applied to other occasions without improvement, which are all within the protection scope of the present application. The scope of protection required by the present application is defined by the claims and their equivalents.

Claims

1. A digital display overspeed switch, characterized in that, Its structure includes: The shell (1) and the base (2) are fixedly connected to form a cavity; A rotating shaft (3) is located on the central axis of the base (2), with one end extending into the cavity. The rotating shaft (3) is used to connect with the target motor shaft. A magnetic ring (5) is fixed on the rotating shaft (3) at one end of the cavity; The main circuit board (7) is located inside the cavity. The main circuit board (7) is provided with a magnetic encoding chip, which is located directly below the magnetic ring (5).

2. The digital display overspeed switch according to claim 1, characterized in that: The back of the housing (1) is provided with an operation panel (6), which includes a digital display screen (61), a safety indicator light (62), an alarm indicator light (63), and operation buttons (64).

3. A digital display overspeed switch according to claim 2, characterized in that: The operation board (6) is fixedly installed above the main circuit board (7), and the operation board (6) and the main circuit board (7) are electrically connected through connectors.

4. A digital display overspeed switch according to claim 2, characterized in that: The main circuit board (7) includes a main control chip, as well as a key input circuit and a display circuit connected to the main control chip. The main control chip is electrically connected to the magnetic encoding chip.

5. A digital display overspeed switch according to claim 4, characterized in that: The operation button (64) is electrically connected to the button input circuit, and the digital display screen (61), safety indicator light (62), and alarm indicator light (63) are electrically connected to the display circuit.

6. A digital display overspeed switch according to claim 1, characterized in that: The cavity is also provided with a second circuit board (8), which includes a power conversion circuit for converting external power into working power for the internal circuit.

7. A digital display overspeed switch according to claim 1, characterized in that: The distance between the magnetic ring (5) and the magnetic coding chip is between 1 mm and 3 mm.

8. A digital display overspeed switch according to claim 1, characterized in that: A bearing (4) is provided at the junction of the rotating shaft (3) and the base (2).

9. A digital display overspeed switch according to claim 1, characterized in that: The housing (1) has a wire outlet hole (11) on one side.

10. A digital display overspeed switch according to claim 1, characterized in that: The base (2) is provided with mounting holes (21), which are used to install and connect the digital overspeed switch to an external motor.

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