Control signal switching circuit of explosion-proof keyboard and explosion-proof keyboard

Abstract

The utility model relates to a control signal switching circuit of an explosion-proof keyboard and the explosion-proof keyboard. The control signal switching circuit comprises a keyboard signal switching unit U2, a USB isolation chip, an optocoupler isolation control unit, a USB input end and at least two USB output ends. Wherein the USB output end, the USB isolation chip, the keyboard signal switching unit U2 and the USB input end are sequentially connected along a USB signal transmission direction. The USB input end is connected with an external explosion-proof keyboard, and the USB output ends are respectively connected with different control hosts. The keyboard signal switching unit U2 is provided with a switching signal input end S, a USB signal input end and a USB signal output end. The keyboard signal switching unit U2 can ensure intrinsic safety isolation and switch USB signals of the explosion-proof keyboard to different control hosts at the same time.

Description

Technical Field

[0001] This application relates to the technical field of mine explosion-proof cabinet equipment, and particularly to a control signal switching circuit for an explosion-proof keyboard and an explosion-proof keyboard. Background Art

[0002] In some special industrial production environments, such as coal mines, ensuring electrical safety is required when using electrical equipment.

[0003] Especially in the coal mine shafts, the air is mixed with flammable and explosive gases such as gas and coal dust. If the electrical equipment does not have explosion-proof functions, the internal circuit of the equipment may generate electric sparks, leading to the detonation of the gases near the equipment.

[0004] Therefore, different from ordinary industrial environments, explosion-proof industrial environments require the installation of flameproof intrinsically safe computers or intrinsically safe controllers, and also require the installation of mine intrinsically safe keyboards (referred to as explosion-proof keyboards) as input devices for intrinsically safe computers or intrinsically safe controllers.

[0005] The existing explosion-proof keyboard structure includes a keyboard body and a USB cable, similar to an ordinary keyboard used in daily life, except that both the keyboard body and the USB cable are designed with intrinsically safe structures. Currently, each control host in a coal mine needs to be equipped with an explosion-proof keyboard for control. On the one hand, purchasing multiple explosion-proof keyboards results in higher costs. On the other hand, the USB cables of multiple explosion-proof keyboards are messy when in use.

[0006] The application document with the patent number CN210033438U discloses a mine tunneling machine explosion-proof operation console. In the mine tunneling machine explosion-proof operation console, the explosion-proof keyboard and multiple control hosts are integrally arranged on the explosion-proof operation console, and the explosion-proof keyboard can switch to control the display screens of multiple control hosts.

[0007] Although the application document with the patent number CN210033438U can achieve the function of explosion-proof keyboard switching control, the explosion-proof keyboard, as a component of the explosion-proof operation console, is not detachable.

[0008] The existing explosion-proof cabinets are different from the integrated structure described in the patent number CN210033438U to achieve intrinsic safety isolation.

[0009] Generally, multiple control hosts are fixed inside an explosion-proof cabinet, and then external devices are connected through the intrinsic safety interfaces on the explosion-proof cabinet to achieve intrinsic safety isolation.

[0010] In order to achieve the switching of the control signal of the explosion-proof keyboard, fixing the explosion-proof keyboard inside the explosion-proof cabinet will cause the explosion-proof keyboard to be unable to be freely disassembled, which will bring inconvenience if the explosion-proof keyboard is damaged.

[0011] Therefore, this application provides a control signal switching circuit for an explosion-proof keyboard and an explosion-proof keyboard. Summary of the Invention

[0012] To overcome the problems existing in the related art, the present application provides a control signal switching circuit for an explosion-proof keyboard, including: a keyboard signal switching unit U2, a USB isolation chip, an opto-isolation control unit, a USB input terminal, and at least two USB output terminals;

[0013] The USB output terminal, the USB isolation chip, the keyboard signal switching unit U2, and the USB input terminal are connected in sequence along the USB signal transmission direction. The USB input terminal is connected to an external explosion-proof keyboard, and the USB output terminals are respectively connected to different control hosts;

[0014] The keyboard signal switching unit U2 is provided with a switching signal input terminal S, a USB signal input terminal, and a USB signal output terminal; the switching signal input terminal S is used to input a keyboard switching signal, the USB signal input terminal is connected to the output terminal of the USB isolation chip, and the USB signal output terminal is connected to the USB output terminal of the control signal switching circuit.

[0015] In one embodiment, the keyboard signal switching unit U2 is a double-pole double-throw switch.

[0016] In one embodiment, the USB isolation chip is used for electrically isolating the USB signal of the external explosion-proof keyboard.

[0017] The second aspect of the present application provides an explosion-proof keyboard, including: a keyboard body, a USB cable, and a signal switcher;

[0018] The signal switcher includes the control signal switching circuit described in the first aspect of the present application;

[0019] The signal switcher is arranged on an explosion-proof cabinet, and the USB output terminals of the signal switcher are simultaneously connected to the USB interfaces of each control host inside the explosion-proof cabinet;

[0020] One end of the USB cable is connected to the keyboard body, and the other end is connected to the USB interface of the signal switcher;

[0021] The signal switcher is used to perform intrinsically safe switching on the USB signal sent by the keyboard body and output it to one of the control hosts.

[0022] In one embodiment, a switching indicator light is further provided on the keyboard body.

[0023] In one embodiment, the keyboard body further includes: a signal switching button, which is used to trigger a keyboard switching signal; the switching indicator light and the signal switching button are integrally arranged.

[0024] In one embodiment, the USB cable is a multi-core cable, including a positive power line, a positive indicator power line, a ground power line, a positive data line, a negative data line, and a switching signal line.

[0025] In one embodiment, the signal switching button is a lit self-locking switch, with different key positions for indicating the status and sending the keyboard switching signal.

[0026] In one embodiment, the signal switcher is installed inside the explosion-proof cabinet. The signal switcher is connected to the USB cable through an interface located outside the explosion-proof cabinet, and the interface of the signal switcher inside the explosion-proof cabinet is connected to at least two control hosts.

[0027] The technical solution provided by this application may include the following beneficial effects:

[0028] In this application, when the processor receives the keyboard switching signal, it outputs the control signal of the keyboard to one of the control hosts by switching the position of the switch through the keyboard signal switching unit U2.

[0029] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit this application. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] By describing the exemplary embodiments of this application in more detail in conjunction with the drawings, the above and other objects, features, and advantages of this application will become more obvious. Among them, in the exemplary embodiments of this application, the same reference numerals generally represent the same components.

[0031] Figure 1 It is a three-dimensional structure diagram of the explosion-proof keyboard shown in the embodiment of this application;

[0032] Figure 2 It is a front view of the explosion-proof keyboard shown in the embodiment of this application;

[0033] Figure 3 is Figure 1 an enlarged view of area I shown;

[0034] Figure 4 It is a circuit structure diagram of the control signal switching circuit of the explosion-proof keyboard provided by the embodiment of this application;

[0035] Figure 5 It is a circuit schematic diagram of the keyboard signal switching unit U2 of the circuit shown in the embodiment of this application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0036] Preferred embodiments of the present application will be described in more detail below with reference to the accompanying drawings. Although the preferred embodiments of the present application are shown in the drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to make the present application more thorough and complete, and to fully convey the scope of the present application to those skilled in the art.

[0037] The terms used in this application are for the purpose of describing specific embodiments only and are not intended to limit the present application. The singular forms "a", "the", and "said" used in this application and the appended claims are also intended to include the plural forms unless the context clearly dictates otherwise. It should also be understood that the term "and / or" used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

[0038] It should be understood that although the terms "first", "second", "third", etc. may be used in this application to describe various information, such information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, the meaning of "a plurality" is two or more unless otherwise specifically defined.

[0039] Embodiment 1

[0040] An explosion-proof cabinet is a specially designed safety cabinet. The explosion-proof control cabinet needs to prevent flammable substances such as flammable gases, dust, or vapors from entering the cabinet, and installing the control host inside the explosion-proof cabinet can prevent the circuits related to the control host from detonating flammable substances.

[0041] In an explosion-proof cabinet in coal mine operations, multiple control hosts usually need to be installed, such as a PLC control host, a safety instrument control host (SIS), a control host network video recorder (NVR), and a data acquisition and processing unit, etc.

[0042] When there are more than 2 control hosts installed in the explosion-proof cabinet, two explosion-proof keyboards are required to connect to the USB interfaces of each control host for control.

[0043] The embodiment of the present application provides a control signal switching circuit for an explosion-proof keyboard. This circuit is installed inside the explosion-proof cabinet. The input end of this circuit is connected to an explosion-proof keyboard, and the output end is simultaneously connected to the USB interfaces of multiple control hosts.

[0044] As Figure 4As shown, the control signal switching circuit of the explosion-proof keyboard includes: a keyboard signal switching unit U2, a USB isolation chip, an optocoupler isolation control unit, a USB input end, and at least two USB output ends.

[0045] Specifically, the USB output end, the USB isolation chip, the keyboard signal switching unit U2, and the USB input end are connected in sequence along the USB signal transmission direction.

[0046] Among them, the USB input end is connected to the peripheral explosion-proof keyboard, and the USB output ends are respectively connected to different control hosts.

[0047] In the embodiment of the present application, the USB+ signal and the USB- signal in the USB signal of the peripheral explosion-proof keyboard are input into the USB isolation chip, and then the USB+ signal and the USB- signal are input into the keyboard signal switching unit U2, and the keyboard signal switching unit U2 inputs the USB+ signal and the USB- signal into one of the USB output ends.

[0048] Further, the optocoupler isolation control unit is electrically connected to the keyboard signal switching unit U2, and is used to receive a keyboard switching signal and instruct the keyboard signal switching unit U2 to switch the USB signal output.

[0049] Figure 5 It is a circuit schematic diagram of the keyboard signal switching unit U2 of the circuit shown in the embodiment of the present application.

[0050] As Figure 5 shown, the keyboard signal switching unit U2 in the embodiment of the present application is provided with a switching signal input end S, a USB signal input end, and a USB signal output end; the switching signal input end S is used to input a keyboard switching signal, the USB signal input end is connected to the output end of the USB isolation chip, and the USB signal output end is connected to the USB output end of the control signal switching circuit.

[0051] As Figure 5 shown, the USB signal input ends of the keyboard signal switching unit U2 are D+ and D-, and the USB signal output ends are HSD1+, HSD1-, HSD2+, and HSD2-.

[0052] Among them, D+ is respectively connected to HSD1+ and HSD2+ through a double-throw switch, and D- is respectively connected to HSD1- and HSD2- through another double-throw switch. Without limitation, if the number of control hosts is greater than 2, the keyboard switching signals are correspondingly changed to represent different switching instructions.

[0053] In an embodiment of the present application, when the processor receives the keyboard switching signal, the control signal of the keyboard is output to one of the control hosts by switching the position of the switch through the keyboard signal switching unit U2.

[0054] Embodiment 2

[0055] Based on Embodiment 1 of the present application, the present application embodiment provides an explosion-proof keyboard as Figure 1 shown.

[0056] As Figures 1 to 3 shown, the explosion-proof keyboard includes: a keyboard body 1, a USB cable 2, and a signal switcher.

[0057] Specifically, the signal switcher is equipped with a control signal switching circuit.

[0058] Furthermore, the signal switcher is arranged on the explosion-proof cabinet. The USB output end of the signal switcher is simultaneously connected to the USB interfaces of each control host inside the explosion-proof cabinet; one end of the USB cable 2 is connected to the keyboard body 1, and the other end is connected to the USB interface of the signal switcher; the signal switcher is used to perform intrinsically safe switching on the USB signal sent by the keyboard body 1 and output it to one of the control hosts.

[0059] In order to simultaneously take into account the free disassembly and intrinsically safe isolation structure of the explosion-proof keyboard, in an embodiment of the present application, the signal switcher is arranged on the side wall of the explosion-proof cabinet, and the signal switcher is connected to the USB interfaces of the control hosts inside the explosion-proof cabinet; while the input end of the signal switcher is a USB interface, which is connected to the keyboard body 1 through the USB cable 2.

[0060] It can be understood that the signal switcher is installed on the explosion-proof cabinet through an intrinsically safe isolation structure, and the intrinsically safe isolation structure can prevent external gases from entering the explosion-proof cabinet.

[0061] When it is necessary to disassemble the explosion-proof keyboard, only the USB cable 2 needs to be pulled out from the input end of the signal switcher.

[0062] Specifically, as Figure 1 shown, the keyboard body 1 is provided with keys and corresponding integrated circuits. Pressing the keys of the keyboard body 1 triggers the integrated circuit to send a control signal, and the control signal is transmitted along the USB cable 2, the signal switcher, and the USB interfaces of the control hosts. The control host decodes the received control signal to determine the corresponding key input.

[0063] Furthermore, in order to switch the transmission of the control host signal, as Figure 3As shown in the figure, the USB cable 2 of the explosion-proof keyboard described in the embodiment of the present application is a multi-core cable, including a power positive line, an indicator power positive line, a power ground line, a data positive line, a data negative line, and a switching signal line.

[0064] Further, a switching indicator light and a signal switching button 10 are also provided on the keyboard body 1, which are matched with the multi-core cable of the USB cable 2.

[0065] Specifically, the signal switching button 10 is a lighted self-locking switch, and different key positions are set to indicate the status and send the keyboard switching signal.

[0066] In the embodiment of the present application, the signal switching button 10 is used to trigger a keyboard switching signal, and the keyboard switching signal is sent to the signal switcher. The signal switcher transfers the USB signal to another control host to realize the switching of the control signal of the explosion-proof keyboard.

[0067] Exemplarily, when the switching control host switch is turned to the NVR control host key position, the corresponding keyboard switching signal of the NVR control host is sent to the signal switcher through the switching signal data line. At the same time, the switching indicator light on the signal switching button 10 emits the light color corresponding to the current keyboard switching signal.

[0068] Figure 2 It is the circuit structure diagram of the signal switcher.

[0069] In the embodiment of the present application, as Figure 2 shown, the signal switcher receives the signal sent by the keyboard body through the input end, and sends the data signal to one of the control hosts through the output end according to the keyboard switching signal.

[0070] In order to facilitate the operator to identify the control host currently controlled by the explosion-proof keyboard.

[0071] Further, a switching indicator light is also provided on the keyboard body. The switching indicator light and the signal switching button 10 are integrally arranged.

[0072] Exemplarily, if two control hosts, a control host and a video recorder, are installed in the explosion-proof cabinet. Then the USB interfaces of the control host and the video recorder are located on the interface panel of the explosion-proof cabinet. Before using the explosion-proof keyboard described in the embodiment of the present application, first connect the two output ends of the signal switcher to the USB interfaces of the control host and the video recorder respectively. One end of the USB cable 2 is inserted into the input end of the signal switcher, and the other end is inserted into the keyboard body 1.

[0073] When it is necessary to switch the explosion-proof keyboard to control another control host, the changeover switch on the keyboard body 1 is toggled to the key position corresponding to the control host. The keyboard switching signal is the electrical signal corresponding to the control host. When the signal switcher receives the electrical signal corresponding to the control host, the data positive line and the data negative line are output to the USB interface of the control host through the internal circuit.

[0074] Regarding the device in the above embodiments, the specific manners in which each module performs operations have been described in detail in the embodiments related to the method, and will not be elaborated here in detail.

[0075] The embodiments of the present application have been described above. The above description is exemplary and not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations are obvious to those of ordinary skill in the art in the technical field without departing from the scope and spirit of the described embodiments. The selection of the terms used herein is intended to best explain the principles of the embodiments, the practical application, or the improvement of the technology in the market, or to enable other ordinary skill in the art in the technical field to understand the embodiments disclosed herein.

Claims

1. A control signal switching circuit for an explosion-proof keyboard, characterized in that: include: A keyboard signal switching unit U2, a USB isolation chip, an optical coupler isolation control unit, a USB input terminal and at least two USB output terminals; The USB output end, the USB isolation chip, the keyboard signal switching unit U2 and the USB input end are connected in sequence along the USB signal transmission direction; The USB input end is connected to an external explosion-proof keyboard, and the USB output ends are connected to different control hosts respectively; The keyboard signal switching unit U2 is provided with a switching signal input terminal S, a USB signal input terminal and a USB signal output terminal; the switching signal input terminal S is used to input a keyboard switching signal, the USB signal input terminal is connected to the output terminal of the USB isolation chip, and the USB signal output terminal is connected to the USB output terminal of the control signal switching circuit.

2. The control signal switching circuit of an explosion-proof keyboard according to claim 1 is characterized in that: The keyboard signal switching unit U2 is a double-pole double-throw switch.

3. The control signal switching circuit of the explosion-proof keyboard according to claim 1 is characterized in that: The USB isolation chip is used to electrically isolate the USB signal of the external explosion-proof keyboard.

4. An explosion-proof keyboard, characterized in that: include: A keyboard body (1), a USB cable (2) and a signal switch; The signal switch comprises the signal switching circuit according to any one of claims 1 to 3; The signal switch is arranged on the explosion-proof cabinet, and the USB output end of the signal switch is simultaneously connected to the USB interfaces of each control host in the explosion-proof cabinet; One end of the USB cable (2) is connected to the keyboard body (1), and the other end is connected to the USB interface of the signal switch; The signal switch is used to perform intrinsically safe switching on the USB signal sent by the keyboard body (1) and output it to one of the control hosts.

5. The explosion-proof keyboard according to claim 4, characterized in that: The keyboard body (1) is also provided with a switching indicator light.

6. The explosion-proof keyboard according to claim 5, characterized in that: The keyboard body (1) further comprises: a signal switching button (10), wherein the signal switching button (10) is used to trigger the keyboard switching signal; the switching indicator light and the signal switching button (10) are integrally arranged.

7. The explosion-proof keyboard according to claim 4, characterized in that: The USB cable (2) is a multi-core cable, comprising a positive power line, a positive indicator power line, a power ground line, a positive data line, a negative data line, and a switching signal line.

8. The explosion-proof keyboard according to claim 6, characterized in that: The signal switching button (10) is a self-locking switch with a light and is provided with different key positions for indicating the state and sending the keyboard switching signal.

9. The explosion-proof keyboard according to claim 6, characterized in that: The signal switch is installed in the explosion-proof cabinet, the signal switch is connected to the USB cable (2) via an interface located outside the explosion-proof cabinet, and the interface of the signal switch in the explosion-proof cabinet is connected to at least two control hosts.

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