Batch running-in test equipment and method for actuating cylinders of whole aircraft

Abstract

The invention relates to the technical field of aircraft actuator cylinder running-in tests, in particular to a whole aircraft actuator cylinder batch running-in test device and a whole aircraft actuator cylinder batch running-in test method. The control cabinet can set the cycle index, the stretching time and the withdrawing time and complete automatic reversing by utilizing the stretching time and the withdrawing time, the hydraulic pump station is used for providing hydraulic pressure and flow required by running-in of the actuator cylinder, and the movable mounting vehicle is used for fixing the actuator cylinder to carry out a running-in test. The movable mounting vehicle comprises a first vehicle and a second vehicle, and a frame of the first vehicle and a frame of the second vehicle are each of an upper-lower double-layer structure. The whole aircraft actuator cylinder batch running-in test equipment and method have the advantages of being convenient to move, easy to install and fix, stable in structure, easy and convenient to operate, high in working efficiency and the like, and the working efficiency is greatly improved.

Description

Technical Field

[0001] The invention relates to the technical field of aircraft actuator running-in test, and in particular to a batch running-in test device and method for the actuators of a whole aircraft. Background Art

[0002] Aircraft actuators need to undergo a run-in test before installation. The existing aircraft actuator run-in is done by using an actuator performance test bench to run-in the actuators one by one. It takes a long time and has low work efficiency to complete the run-in of different types of actuators on the same aircraft. There are many types of actuators on the same aircraft, with large quantities and inconsistent size parameters. If the actuators are run-in at the same time, it will be difficult to design the structure and control the run-in.

[0003] Therefore, in order to meet the running-in test requirements of different types of actuators of the entire aircraft and improve work efficiency, it is necessary to design an actuator running-in test equipment to meet the batch running-in test requirements of different types of actuators of the entire aircraft and improve work efficiency. Summary of the invention

[0004] In order to solve the above technical problems, the present invention proposes a batch running-in test device and method for the actuators of the entire aircraft.

[0005] The technical problem to be solved by the present invention is achieved by adopting the following technical solutions:

[0006] A batch running-in test equipment for the entire aircraft actuator, comprising:

[0007] A control cabinet is used for data collection and control, and can complete the setting of the number of cycles, the extension time, the retraction time, and complete automatic reversing using the extension and retraction time. The control cabinet includes a cabinet, a control panel, a keyboard and a mouse, an industrial computer, a drawer, and a baffle arranged on the cabinet. The industrial computer is connected to the control panel and the keyboard and the mouse;

[0008] A hydraulic pump station, used to provide the required hydraulic pressure and flow for the running-in of the actuator cylinder, the hydraulic pump station includes an oil tank, a hydraulic power source connected to the oil tank pipeline, an oil supply P port connected to the hydraulic power source pipeline, an oil return R port connected to the oil tank pipeline, a first reversing control solenoid valve, a second reversing control solenoid valve, a third reversing control solenoid valve, and a fourth reversing control solenoid valve respectively connected to the oil supply P port and the oil return R port pipeline;

[0009] A mobile installation vehicle is used to fix an actuator cylinder for a running-in test. The mobile installation vehicle includes a vehicle 1 and a vehicle 2. Both the vehicle 1 and the vehicle 2 include a vehicle frame and wheels arranged at the bottom of the vehicle frame. The vehicle frames of the vehicle 1 and the vehicle 2 are both upper and lower double-layer structures. The first reversing control solenoid valve is connected to the actuator cylinder pipeline on the upper layer of the vehicle 1, the second reversing control solenoid valve is connected to the actuator cylinder pipeline on the lower layer of the vehicle, the third reversing control solenoid valve is connected to the actuator cylinder pipeline on the upper layer of the vehicle 2, and the fourth reversing control solenoid valve is connected to the actuator cylinder pipeline on the lower layer of the vehicle 2.

[0010] As a further improvement of the present invention, the control panel is provided with a display, a "pressure adjustment" knob, a "pump on" button, a "pump off" button, a "main power on" button, a "main power off" button, and an "emergency stop" button.

[0011] As a further improvement of the present invention, the control panel is provided with an upper working indicator light for vehicle one, a lower working indicator light for vehicle two, an upper working indicator light for vehicle two, a lower working indicator light for vehicle two, an overpressure indicator light, an oil shortage indicator light, an overtemperature indicator light, a fault alarm indicator light, and a 24VDC power supply indicator light.

[0012] As a further improvement of the present invention, the display includes automatic, manual and function interface selection, extension time setting, retraction time setting and cycle number setting.

[0013] As a further improvement of the present invention, the display has a pressure display function, a temperature display function, a current cycle number display function, a working status display function, a vehicle one extending display function, a vehicle one retracting display function, a vehicle one extending display function, a vehicle one retracting display function, a vehicle two extending display function, a vehicle two retracting display function, a vehicle two lowering display function, a vehicle two retracting display function and a cycle indication display function.

[0014] As a further improvement of the present invention, the hydraulic power source includes an oil pump connected to the oil tank pipeline, an accumulator connected to the oil pump and the oil supply P port pipeline respectively, a first one-way valve, a fine oil filter, a coarse oil filter and an electromagnetic proportional overflow valve arranged in sequence between the oil pump and the accumulator, a safety valve, a first ball valve, a second ball valve, a second one-way valve and an oil supply pressure sensor arranged in sequence between the accumulator and the oil supply P port.

[0015] As a further improvement of the present invention, a third one-way valve, a sampling valve, an oil return filter, a radiator, and an electromagnetic water valve are sequentially arranged between the oil tank and the oil return R port.

[0016] As a further improvement of the present invention, a liquid level meter and a temperature sensor are arranged in the oil tank, and an oil drain ball valve and an oil supply ball valve are externally connected.

[0017] As a further improvement of the present invention, a first product bracket is arranged on the upper layer of the vehicle one, a second product bracket is arranged on the upper layer and lower layer of the vehicle one, a first clamp is arranged on the lower layer of the vehicle one and the upper layer of the vehicle two, and a second clamp and a tail stock are arranged on the lower layer of the vehicle two.

[0018] A batch running-in test method for an entire aircraft actuator cylinder, using the above-mentioned batch running-in test equipment for an entire aircraft actuator cylinder, comprises the following steps:

[0019] Step 1: Install the twelve actuators numbered 0 to 11 on the upper and lower layers of vehicle 1 and the upper and lower layers of vehicle 2 in sequence, and connect the oil pipes;

[0020] Step 2: Press the "Main Power On" button on the control panel to start the device power, the industrial computer starts automatically, and the display enters the control interface;

[0021] Step 3: Press the "Pump On" button on the control panel to start the oil pump. Before starting the oil pump, check whether the "Pressure Adjustment" knob is in the minimum position;

[0022] Step 4: Adjust the "pressure adjustment" knob on the control panel and observe that the pressure displayed on the control interface reaches 27MPa;

[0023] Step 5: Select "Automatic" operation mode, "Lathe 1st upper layer", "Lathe 1st lower layer", "Lathe 2nd upper layer", "Lathe 2nd lower layer", set "Extend time", "Retract time", "Number of cycles", click "Cycle start", the actuators on the 1st upper layer, the 1st lower layer, the 2nd upper layer, and the 2nd lower layer will be run-in at the same time, and "Current number of cycles" will show the number of cycles that have been run-in. When the set number of cycles is reached, the cycle run-in will stop automatically;

[0024] Step 6: After the cycle running-in is completed, adjust the "pressure adjustment" knob to adjust the pressure to the minimum;

[0025] Step 7: Press the "Pump Off" button to turn off the oil pump;

[0026] Step 8: Close the control software and industrial computer in turn;

[0027] Step 9: Press the "Main Power Off" button to turn off the power of the device.

[0028] The beneficial effects of the present invention are:

[0029] The present invention provides a batch running-in test device and method for the actuators of an entire aircraft, which has the advantages of convenient movement, simple installation and fixing, stable structure, simple operation, high work efficiency, etc. The actuators of the entire aircraft are summarized and counted, and similar actuators are fixed together, and two mobile car-type actuator installation platforms are designed. Each car body is divided into an upper and lower layer, and each car body is provided with a hydraulic electromagnetic reversing valve to realize the reversing running-in of the actuators on the car layer, so that the actuators on one layer of the same car can be run-in in the same batch, and the actuators on four layers of two cars can be run-in at the same time, which greatly improves the work efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The present invention is further described below in conjunction with the accompanying drawings and embodiments:

[0031] Figure 1 It is a schematic diagram of the structure of the device in the present invention;

[0032] Figure 2 This is a schematic diagram of the control cabinet structure in the present invention;

[0033] Figure 3 This is a schematic diagram of the structure of the control panel in the present invention;

[0034] Figure 4 is a schematic diagram of a control interface on a display in the present invention;

[0035] Figure 5 is a schematic diagram of the operation interface on the display in the present invention;

[0036] Figure 6 It is a front structural schematic diagram of the hydraulic pump station in the present invention;

[0037] Figure 7 It is a schematic diagram of the top view of the structure of the hydraulic pump station in the present invention;

[0038] Figure 8 The hydraulic control principle of the present invention Figure 1 ;

[0039] Fig. 9 The hydraulic control principle of the present invention Figure 2 ;

[0040] Fig.10 It is a structural schematic diagram of the mobile installation vehicle in the present invention;

[0041] Fig.11 This is the installation layout diagram of the upper layer actuator of the vehicle in the present invention;

[0042] Fig.12 This is the installation layout diagram of the lower level actuator of the vehicle in the present invention;

[0043] Fig.13 This is the installation layout diagram of the upper actuator of the second car in the present invention;

[0044] Fig.14 This is the installation layout diagram of the lower level actuator of the second car in the present invention.

[0045] In the figure:

[0046] 101. Cabinet; 102. Control panel; 103. Keyboard and mouse; 104. Industrial computer; 105. Drawer and baffle;

[0047] 201, oil pump; 202, first non-return valve; 203, refined oil filter; 204, crude oil filter; 205, electromagnetic proportional relief valve; 206, pressure accumulator; 207, safety valve; 208, first ball valve; 209, second ball valve; 210, second non-return valve; 211, oil supply pressure sensor; 212, third non-return valve; 213, sampling valve; 214, return oil filter; 215, radiator; 216, liquid level gauge; 217, temperature sensor; 218, oil tank; 219, oil drain ball valve; 220, oil supply ball valve; 221, electromagnetic water valve; 222, first reversing control solenoid valve; 223, second reversing control solenoid valve; 224, third reversing control solenoid valve; 225, fourth reversing control solenoid valve;

[0048] 301, wheel; 302, frame; 303, first product bracket; 304, second product bracket; 305, first clamp; 306, second clamp; 307, buttstock. DETAILED DESCRIPTION

[0049] In order to make the technical means, creative features, objectives and effects achieved by the present invention easier to understand, the present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0050] like Figure 1 As shown, a batch running-in test equipment for the actuator of the entire aircraft mainly includes: a control cabinet, a hydraulic pump station and a mobile installation vehicle.

[0051] The control cabinet is used for data collection and control, and can complete the setting of cycle times, extension time, and retraction time, and use the extension and retraction time to complete automatic reversing. Figure 2 As shown, the control cabinet includes a cabinet 101 , a control panel 102 , a keyboard and mouse 103 , an industrial computer 104 , a drawer and a baffle 105 , and the industrial computer 104 is connected to the control panel 102 and the keyboard and mouse 103 .

[0052] The control system on the industrial computer 104 develops control software based on the LabView platform, and uses computer PCI acquisition boards and relays to perform data acquisition and control.

[0053] like Figure 3As shown, the control panel 102 is provided with a display, a "pressure adjustment" knob, a "pump on" button, a "pump off" button, a "main power on" button, a "main power off" button, and an "emergency stop" button; it is provided with a car one upper layer working indicator light, a car one lower layer working indicator light, a car two upper layer working indicator light, a car two lower layer working indicator light, an overpressure indicator light, an oil shortage indicator light, an overtemperature indicator light, a fault alarm indicator light, and a 24VDC power indicator light;

[0054] like Figure 4 and Figure 5 The device control interface shown on the display has automatic, manual and function interface selection, extension time setting, retraction time setting and cycle number setting; it has pressure display function, temperature display function, current cycle number display function, working status display function, vehicle one extension display function, vehicle one retraction display function, vehicle one extension display function, vehicle one retraction display function, vehicle two extension display function, vehicle two retraction display function, vehicle two extension display function, vehicle two retraction display function and cycle indication display function. It can control functions such as oil pump start and stop, cooling, unloading, cycle start and stop, number of times reset, etc.

[0055] like Figures 6 to 9 The figure shows the structure of the hydraulic pump station and the hydraulic control principle diagram, and the hydraulic pump station is used to provide the required hydraulic pressure and flow for the running-in of the actuator. The hydraulic pump station includes an oil tank 218, a hydraulic power source connected to the oil tank 218 pipeline, an oil supply P port connected to the hydraulic power source pipeline, an oil return R port connected to the oil tank 218 pipeline, a first reversing control solenoid valve 222, a second reversing control solenoid valve 223, a third reversing control solenoid valve 224, and a fourth reversing control solenoid valve 225 connected to the oil supply P port and the oil return R port pipeline respectively.

[0056] Specifically, the hydraulic power source includes an oil pump 201 connected to the oil tank 218 pipeline, an accumulator 206 connected to the oil pump 201 and the oil supply P port pipeline respectively, a first check valve 202, a fine oil filter 203, a coarse oil filter 204 and an electromagnetic proportional relief valve 205 arranged in sequence between the oil pump 201 and the accumulator 206, a safety valve 207, a first ball valve 208, a second ball valve 209, a second check valve 210 and an oil supply pressure sensor 211 arranged in sequence between the accumulator 206 and the oil supply P port. The oil pump 201 is connected to an electric motor, which is a 37kw / 1500 rpm three-phase asynchronous motor, and the oil pump is an imported variable piston pump with a flow rate of 65L and a pressure resistance of 31.5MPa. Hydraulic power is provided for the running-in of the actuator. A third one-way valve 212, a sampling valve 213, an oil return filter 214, a radiator 215, and an electromagnetic water valve 221 are sequentially arranged between the oil tank 218 and the oil return port R. A liquid level meter 216 and a temperature sensor 217 are arranged inside the oil tank 218, and an oil drain ball valve 219 and an oil supply ball valve 220 are connected to the outside.

[0057] Specifically, the oil is driven by the motor to drive the oil pump 201, sucking the oil from the oil tank 218, passing through the first check valve 202, the fine oil filter 203, the coarse oil filter 204, the electromagnetic proportional relief valve 205 for pressure regulation, and the pressure accumulator 206 for pressure storage, and then the pressure is safely controlled by the safety valve 207, and then the oil enters the oil supply P port through the second ball valve 209 and the oil supply pressure sensor 211, and then passes through the first reversing control solenoid valve 222, the second reversing control solenoid valve 223, the third reversing control solenoid valve 224, and the fourth reversing control solenoid valve 225 to control the running-in of the actuator on the parking space, and then returns to the oil tank 218 through the return oil R port, the third check valve 212, the return oil filter 214, and the radiator 215. Opening the first ball valve 208 can realize the self-circulation cleaning of the hydraulic pump station, and the oil is sampled and tested through the sampling valve 213. The temperature sensor 217 monitors the oil temperature at any time, and the level meter 216 monitors the oil tank level.

[0058] like Fig.10As shown, the mobile installation vehicle is used to fix the actuator for running-in test, and the mobile installation vehicle includes vehicle one and vehicle two, and both the vehicle one and vehicle two include a frame 302 and a wheel 301 arranged at the bottom of the frame 302, and the frames 302 of the vehicle one and vehicle two are both upper and lower double-layer structures, the first reversing control solenoid valve 222 is connected to the actuator pipeline on the upper layer of the vehicle one, the second reversing control solenoid valve 223 is connected to the actuator pipeline on the lower layer of the vehicle, the third reversing control solenoid valve 224 is connected to the actuator pipeline on the upper layer of the vehicle two, and the fourth reversing control solenoid valve 225 is connected to the actuator pipeline on the lower layer of the vehicle two. A first product support 303 is provided on the upper layer of the vehicle one, a second product support 304 is provided on the upper and lower layers of the vehicle one, a first clamp 305 is provided on the lower layer of the vehicle one and the upper layer of the vehicle two, and a second clamp 306 and a buttstock 307 are provided on the lower layer of the vehicle two.

[0059] A batch running-in test method for an entire aircraft actuator cylinder, using the above-mentioned batch running-in test equipment for an entire aircraft actuator cylinder, comprises the following steps:

[0060] Step 1: Change the twelve actuators numbered 0 to 11 to: actuator 0, actuator 1, actuator 2, actuator 3, actuator 4, actuator 5, actuator 6, actuator 7, actuator 8, actuator 9, actuator 10, actuator 11, according to the Fig.11 , Fig.12 , Fig.13 , Fig.14 The layout diagram shown is fixedly installed on the upper and lower layers of car one and the upper and lower layers of car two in sequence, and the oil pipes are connected.

[0061] Step 2: Press the "main power on" button on the control panel 102 to start the device power, the industrial computer 104 starts automatically, and the display enters the control interface.

[0062] Step 3: Press the “Pump On” button on the control panel 102 to start the oil pump 201 . Before starting the oil pump 201 , check whether the “Pressure Adjustment” knob is at the minimum position.

[0063] Step 4: Adjust the "pressure adjustment" knob on the control panel 102 and observe that the pressure displayed on the control interface reaches 27 MPa.

[0064] Step 5: Select "Automatic" operation mode, "Lathe 1 upper layer", "Lathe 1 lower layer", "Lathe 2 upper layer", "Lathe 2 lower layer", set "Extend time", "Retract time", "Number of cycles", click "Cycle start", the actuators on the 1 upper layer, 1 lower layer, 2 upper layer and 2 lower layer will be run-in at the same time, "Current number of cycles" shows the number of cycles run-in, when the set number of cycles is reached, the cycle run-in will stop automatically.

[0065] Step 6: After the cycle running-in is completed, adjust the "pressure adjustment" knob to adjust the pressure to the minimum.

[0066] Step 7: Press the “Pump Off” button to turn off the oil pump 201.

[0067] Step 8: Close the control software and industrial computer 104 in sequence.

[0068] Step 9: Press the "Main Power Off" button to turn off the power of the device.

[0069] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions only describe the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A batch running-in test equipment for the entire aircraft actuator, characterized by: include: A control cabinet is used for data collection and control, and is capable of completing the setting of cycle times, extension time, and retraction time, and completing automatic reversing using the extension and retraction time. The control cabinet comprises a cabinet (101), a control panel (102) arranged on the cabinet (101), a keyboard and mouse (103), an industrial computer (104), a drawer and a baffle (105), and the industrial computer (104) is connected to the control panel (102) and the keyboard and mouse (103); A hydraulic pump station, used for providing the required hydraulic pressure and flow for the running-in of the actuator cylinder, the hydraulic pump station comprising an oil tank (218), a hydraulic power source connected to the pipeline of the oil tank (218), an oil supply port P connected to the pipeline of the hydraulic power source, an oil return port R connected to the pipeline of the oil tank (218), a first reversing control solenoid valve (222), a second reversing control solenoid valve (223), a third reversing control solenoid valve (224), and a fourth reversing control solenoid valve (225) respectively connected to the pipelines of the oil supply port P and the oil return port R; A mobile installation vehicle is used to fix an actuator cylinder for a running-in test. The mobile installation vehicle comprises a vehicle 1 and a vehicle 2. Both the vehicle 1 and the vehicle 2 comprise a vehicle frame (302) and a wheel (301) arranged at the bottom of the vehicle frame (302). The vehicle frames (302) of the vehicle 1 and the vehicle 2 are both upper and lower double-layer structures. The first reversing control solenoid valve (222) is connected to the actuator cylinder pipeline on the upper layer of the vehicle 1, the second reversing control solenoid valve (223) is connected to the actuator cylinder pipeline on the lower layer of the vehicle, the third reversing control solenoid valve (224) is connected to the actuator cylinder pipeline on the upper layer of the vehicle 2, and the fourth reversing control solenoid valve (225) is connected to the actuator cylinder pipeline on the lower layer of the vehicle 2.

2. The batch running-in test equipment for the entire aircraft actuator according to claim 1, characterized in that: The control panel (102) is provided with a display, a "pressure adjustment" knob, a "pump on" button, a "pump off" button, a "main power on" button, a "main power off" button, and an "emergency stop" button.

3. The whole aircraft actuator batch running-in test equipment according to claim 1, characterized in that: The control panel (102) is provided with an upper working indicator light for car 1, a lower working indicator light for car 1, an upper working indicator light for car 2, a lower working indicator light for car 2, an overpressure indicator light, an oil shortage indicator light, an overtemperature indicator light, a fault alarm indicator light, and a 24VDC power supply indicator light.

4. The whole aircraft actuator batch running-in test equipment according to claim 2, characterized in that: The display includes automatic, manual and function interface selection, extension time setting, retraction time setting and cycle number setting.

5. The batch running-in test equipment for the entire aircraft actuator according to claim 2, characterized in that: The display has pressure display function, temperature display function, current cycle number display function, working status display function, vehicle one extending display function, vehicle one retracting display function, vehicle one extending display function, vehicle one retracting display function, vehicle two extending display function, vehicle two retracting display function, vehicle two lowering display function, vehicle two lowering display function and cycle indication display function.

6. The batch running-in test equipment for the entire aircraft actuator according to claim 1, characterized in that: The hydraulic power source comprises an oil pump (201) connected to the oil tank (218) pipeline, an accumulator (206) connected to the oil pump (201) and the oil supply P port pipeline respectively, a first check valve (202), a fine oil filter (203), a coarse oil filter (204) and an electromagnetic proportional relief valve (205) arranged in sequence between the oil pump (201) and the accumulator (206), a safety valve (207), a first ball valve (208), a second ball valve (209), a second check valve (210) and an oil supply pressure sensor (211) arranged in sequence between the accumulator (206) and the oil supply P port.

7. The batch running-in test equipment for the entire aircraft actuator according to claim 1, characterized in that: A third one-way valve (212), a sampling valve (213), an oil return filter (214), a radiator (215), and an electromagnetic water valve (221) are sequentially arranged between the oil tank (218) and the oil return port R.

8. The batch running-in test equipment for the entire aircraft actuator according to claim 1, characterized in that: The oil tank (218) is provided with a liquid level meter (216) and a temperature sensor (217), and is externally connected to an oil drain ball valve (219) and an oil supply ball valve (220).

9. The batch running-in test equipment for the entire aircraft actuator according to claim 1, characterized in that: A first product support (303) is arranged on the upper layer of the vehicle one, a second product support (304) is arranged on the upper layer and the lower layer of the vehicle one, a first clamp (305) is arranged on the lower layer of the vehicle one and the upper layer of the vehicle two, and a second clamp (306) and a buttstock (307) are arranged on the lower layer of the vehicle two.

10. A batch running-in test method for the entire aircraft actuator, characterized in that: A batch running-in test equipment for the entire aircraft actuator according to any one of claims 1 to 9, The following steps are involved: Step 1: Install the twelve actuators numbered 0 to 11 on the upper and lower layers of vehicle 1 and the upper and lower layers of vehicle 2 in sequence, and connect the oil pipes; Step 2: Press the "main power on" button on the control panel (102) to start the device power supply, the industrial computer (104) starts automatically, and the display enters the control interface; Step 3: Press the "Pump On" button on the control panel (102) to start the oil pump (201). Before starting the oil pump (201), check whether the "Pressure Adjustment" knob is at the minimum position; Step 4: Adjust the "pressure adjustment" knob on the control panel (102) and observe that the pressure displayed on the control interface reaches 27 MPa; Step 5: Select "Automatic" operation mode, "Lathe 1st upper layer", "Lathe 1st lower layer", "Lathe 2nd upper layer", "Lathe 2nd lower layer", set "Extend time", "Retract time", "Number of cycles", click "Cycle start", the actuators on the 1st upper layer, the 1st lower layer, the 2nd upper layer, and the 2nd lower layer will be run-in at the same time, "Current number of cycles" will show the number of cycles run-in, and the cycle run-in will stop automatically when the set number of cycles is reached; Step 6: After the cycle running-in is completed, adjust the "pressure adjustment" knob to adjust the pressure to the minimum; Step 7: Press the "Pump Off" button to turn off the oil pump (201); Step 8: shut down the control software and industrial computer (104) in sequence; Step 9: Press the "Main Power Off" button to turn off the power of the device.

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