CN217587525U

CN217587525U - Multifunctional portable engine fault detector

Info

Publication number: CN217587525U
Application number: CN202220392291.3U
Authority: CN
Inventors: 白茹; 李嘉琦; 寇传嘉
Original assignee: Hangzhou Dianzi University
Current assignee: Zhejiang Jialiang Zhidong Technology Co.,Ltd.
Priority date: 2022-02-25
Filing date: 2022-02-25
Publication date: 2022-10-14
Anticipated expiration: 2032-02-25

Abstract

The utility model relates to a multifunctional portable engine fault detector, which comprises a system fault detection and display module, a power supply control module and a portable box body; the method comprises the following steps that a built-in MCU reads data output by an engine ECM through a CAN bus and displays all parameters on an external display screen in real time, the MCU gives an alarm for the parameters exceeding a threshold value through judgment, and in addition, emergency shutdown, DPF regeneration and oil pressure regulation of the engine are controlled through an external key; storing the data, and transmitting the data to an upper computer to realize further fault analysis; the power supply control module controls the on-off of a circuit power supply of the measurement and control system and controls the ignition start of the engine; the portable box of the tester encapsulates the system measurement and control panel, the electric wire and the electronic component which are required by the detection into the box; the utility model discloses it is practical portable, can anytime and anywhere carry out the off-line measuring to the engine, each item parameter index of audio-visual reading engine on the display screen of panel, the trouble that can swiftly investigate the engine and appear.

Description

Multifunctional portable engine fault detector

Technical Field

The utility model relates to an engine test control field specifically is a multi-functional portable engine fault detector.

Background

When the engineering truck equipment such as a large excavator and the like is used, if a diesel engine fails, prompt information of the failure of the engine can be obtained on a control panel of the whole truck such as the excavator and the like, however, in the process of delivery inspection and maintenance of the transmitter, the transmitter is usually detached and separated from the whole truck for detection. Under the condition of off-line with the whole vehicle, how to obtain system related parameters of the engine and detect faults is a technical problem in the practical application process. At present, no related technical utility model is available in China. The utility model discloses the off-line engine fault detector that the technique provided carries out off-line detection's equipment after the engine breaks down, through data line connection engine and detector, utilize the ignition of detector control engine to start, the engine is with the rotational speed value after the start, the machine oil pressure value, the fuel pressure value, the water temperature value, the pressure boost temperature value, the fuel temperature value, data such as the behavior of Diesel Particulate Filter (Diesel Particulate Filter, DPF) are shown through the display screen of detector, can read the concrete numerical value of each parameter simultaneously in real time, also can see the position of concrete trouble through the malfunction alerting of display screen, the design uses the display screen more practical convenient, it is clear. The utility model discloses a Controller Area Network (CAN) bus carries out data reception and control command's transmission, safe and reliable. Additionally, the utility model relates to an use Electrically Erasable Programming Read Only Memory (EEPROM) to carry out the storage that detects data, on the one hand can realize further ground fault analysis and show on the screen through the procedure handling with the multiunit data of storage, on the other hand Memory chip can carry out the outage of data and preserve, can save the data that detect outside, reach the host computer with data transmission through serial ports or wireless transmission's mode after getting back to the repair shop, it realizes further remote engine off-line fault analysis to handle data on the host computer. The engine fault detector is manufactured into a portable box structure, and can realize primary real-time engine fault detection outside a repair shop and on the site of fault occurrence.

The utility model discloses the technique has corresponding control function, for example emergency shutdown button and DPF manual regeneration button. When the engine has serious faults and is dangerous, the emergency stop button can be pressed down to stop the engine. The working principle of the manual regeneration of the DPF is as follows: the particle catcher of the diesel engine is a large filter element for filtering particles, and collects all impurities such as black smoke generated by the engine, so that the emission of the particles is reduced, but the more and more black smoke collected in the particle catcher can slowly cause the back pressure of exhaust to be high, so that the power of the engine is influenced. In order to make the engine work normally continuously, the collected black smoke needs to be burnt by means of exhaust gas heating, and the process is called regeneration. The DPF regeneration is divided into active regeneration and passive regeneration, the active regeneration is automatically executed when the engine runs to a load of medium or above, for example, running at high speed and running at a provincial road, the engine can automatically execute running regeneration, the passive regeneration is executed after running for a period of time under low-speed and low-load working conditions such as urban working conditions and traffic jam, a driver is required to press a regeneration button on the vehicle to execute the DPF regeneration after stopping, and usually, the in-situ regeneration can be executed after a regeneration indicator lamp is lightened. The utility model discloses an engine fault tester can monitor engine DPF's behavior, blocks up when serious at DPF, and the display screen can warn, presses the manual regeneration button of DPF this moment, can realize passive regeneration. DPF regeneration not only can carry out exhaust-gas treatment, and the environmental protection, more importantly can clear up the particulate matter, prevents that the exhaust duct of engine from taking place to block up, plays certain maintenance and maintenance effect, further can improve the working property of engine, increase of service life.

There are also some cases of engine fault testers, such as the utility model patent No. CN 202021421615.9. The design is that a high engine tester shell of security does not relate to detection circuit. Patent CN 210051545U's utility model designs is an engine detection case, mainly detects the trouble that the engine appears, but its panel is done convertible be unfavorable for the protection of inside chip and circuit, and the overall design security reduces, and in addition, data reception and demonstration that its design only can be simple are compared with it, the utility model discloses the technique not only can carry out fault detection and demonstration to engine system, still has certain data analysis and control function, can make urgent processing to the trouble engine, still has DPF regeneration function, furtherly, can also revise the transmitter parameter, through the contrast, the utility model discloses a function is more perfect, satisfies the more needs of engine emergency trouble test as far as when practical convenient.

Through the contrast, can discover the utility model discloses a multi-functional portable engine fault detector has very big advantage, need not tear the engine out and can detect each item parameter of engine, shows the concrete reason of trouble. The utility model discloses can realize carrying out real-time detection, monitoring, transmission and parameter modification to high pressure confession rail engine, middling pressure confession rail engine and low pressure common rail engine's local data under the line. Additionally, the utility model discloses multi-functional portable engine fault detector of technical design not only can carry out fault detection to the engine of road vehicles such as cars, also can be applied to the engine fault detection of non-road vehicle of traveling, for example: engineering machinery such as a forklift, an excavator, a loader, and the like.

Disclosure of Invention

The utility model aims to provide a multifunctional portable engine fault detector; the utility model adopts special plastic to make a cubic box, which is convenient to carry and CAN well protect the internal measurement and control panel and circuit, the data transmission adopts CAN bus standard interface to connect the engine and the detector, the measurement and control panel adopts a display screen to display various data visually in real time, and the power control circuit adopts a button and a relay to start the button; the whole box body of the engine fault detector is portable and flexible in design, the connection of a data line is more universal and universal, the display of a test panel is concise and clear, and the control test is safer and more reliable.

The utility model discloses a system's fault detection and display module, power control module and portable box. The power supply control module and the system fault detection and display module are all arranged in the portable box body; the power supply control module is used for externally connecting a storage battery for testing power supply, starting a motor through a starting motor module connected with an engine for igniting the generator and controlling the on-off state of a power supply; the system fault detection and display Module is used for realizing a Control detection function of an Engine Control Module (ECM) and a display function of feedback data of an Engine built-in sensor.

The portable box body comprises a packaging portable box, a system measurement and control panel and a bottom layer electromagnetic relay fixing panel; the portable packaging box is used for packaging the system measurement and control panel, the electric wires and the electronic components required by detection into the cubic box body, so that the portable packaging box is convenient to carry and test; the system measurement and control panel is used for fixing a system fault detection and display module, a shutdown key for controlling the single chip microcomputer module, a DPF manual regeneration key, an accelerator adjustment key and a display screen of the display module, and fixing an engine ignition starting binding post, power supply positive and negative binding posts, a starting button, a switch button and a CAN bus interface of the power supply control module; bottom electromagnetic relay fixed panel for place power control module's electromagnetic relay and the wiring between each module, electromagnetic relay fixes on the bottom panel, and bottom panel four corners sets up four spinal branch daggers and is used for the fixed system to detect the panel.

Preferably, the portable packaging box is of a cubic structure and is made of light-weight, firm and anti-falling plastic.

Preferably, the electromagnetic relay is fixed to the electromagnetic relay fixing panel by a screw and a nut.

The system fault detection and display module comprises a single chip microcomputer module and a screen display module.

The single chip microcomputer Module is connected with an Engine Control Module (ECM) through a CAN bus and is connected with the screen display Module through a DuPont line; the screen display module comprises a display screen, and data received by the built-in MCU are displayed on the display screen in real time;

the shutdown key is pressed to send an MCU level signal, and the engine is controlled to be shut down through the CAN bus after being processed by the MCU; after the DPF breaks down during automatic regeneration, pressing a DPF manual regeneration key to enable the MCU to send an instruction to an Engine Control Module (ECM) for manual DPF regeneration; the size of an accelerator driven by an actual vehicle is simulated by pressing an upper accelerator adjusting button and a lower accelerator adjusting button, so that the pressure of the accelerator of an engine can be detected;

the single chip microcomputer module is a minimum system composed of a built-in Micro Controller Unit (MCU) and related additional components and used for receiving, processing, judging and controlling data;

the CAN bus data interface is used for direct communication between the engine and the detector, the engine ECM is connected with the data interface to transmit relevant parameters to the MCU arranged in the singlechip module and display the parameters on the display screen in real time, the MCU compares the received data with parameter threshold values set by a program, the MCU CAN display characters on the display screen to give an alarm for the parameters exceeding the threshold values, meanwhile, a stop button, a DPF manual regeneration button and an accelerator adjustment button are arranged, the corresponding buttons are pressed down, and the engine is controlled by the aid of the connection of the data interface after the processing of the MCU.

Further, the MCU is connected with an upper computer, and stored data are transmitted to the upper computer to realize further fault analysis.

The single chip microcomputer module comprises an MCU, a key reset device, an SWD interface, a USART serial port, a CAN bus driving chip and an external EEPROM and is used for receiving data and displaying the data on a screen in real time; signals can be sent to control the engine to realize related operation, and meanwhile, data can be stored in the EEPROM to realize further fault analysis; after the detection is finished, the stored data are transmitted to an upper computer in a mode of directly connecting a computer through a USART serial port or connecting a wireless module to the USART port for wireless transmission; preferably, a 51 series single chip microcomputer or an STM32 series single chip microcomputer is adopted.

And an SWD interface of the singlechip module is led out for program burning, and the program can be updated for function upgrading at the later stage. The USART serial port of the single chip microcomputer module can be directly connected with an upper computer for data transmission, and meanwhile, the serial port can be connected with the wireless module for function expansion and wireless transmission of data. And a CAN bus driving chip of the singlechip module is used for connecting a CAN bus interface with the MCU for high-speed data transceiving. The external EEPROM of the single chip microcomputer module is an electrically erasable programmable read-only memory, is a memory chip with no data loss after power failure, can store collected engine related parameters and upload the parameters to a computer for data analysis at a later period, and is complex and wide in application.

Preferably, the screen Display module is a dot matrix Liquid Crystal Display (LCD), a Thin Film Transistor Liquid Crystal Display (TFT LCD), or an Organic Light-Emitting Diode (OLED) Display. The shutdown key, the DPF manual regeneration key and the throttle adjusting key are all self-reset touch keys, and the keys can be rebounded and reset after being released by pressing the keys. The CAN bus data interface adopts a universal nine-hole CAN bus connector.

The power supply control module comprises an engine ignition starting binding post, power supply positive and negative binding posts, a starting button, a switch button and an electromagnetic relay fixed on the bottom layer panel; wherein the engine ignition starting terminal is connected to a starting motor of the engine for ignition starting; the power supply positive and negative terminals are used for being externally connected with a storage battery to supply power to the system; pressing a start button to control an electromagnetic relay to start a motor to ignite a generator; the switch button is used for controlling the on-off state of the power supply.

The engine ignition starting terminal uses a red rotary nut terminal, and a lead of an engine starting motor is fixedly connected with a screw nut. The positive and negative terminals of the power supply are respectively a red-black rotary nut terminal and can be fixedly connected with the leads connected with the positive and negative electrodes of the storage battery. The starting button is a self-reset button, can be rebounded and reset after being pressed by a loose hand, and has one end connected with the anode of the power supply and the other end connected with the control end of the electromagnetic relay. The switch button is a self-locking button, can not be bounced to be ON when being pressed down, and is OFF when being pressed again and rebounded to be in the original position.

The electromagnetic relay control end fixed on the bottom panel is connected with the starting button and the power cathode, the controlled end is connected with the power anode and the starting motor and is usually in a disconnected state, the power is supplied after the switch button is pressed, and then when the starting button is pressed, the electromagnetic relay controls the controlled end to be closed and the motor is started.

The utility model has the advantages that:

(1) The system fault detection and display module is used for designing a display screen to display various parameter indexes in real time, is clear, and CAN be clear at a glance for the position where a fault occurs.

(2) After the positive and negative wiring terminals of the power supply control module are connected with the storage battery, the on-off of the power supply can be controlled through the self-locking button, the starting button indirectly controls the ignition of the engine through the electromagnetic relay, the front part and the rear part are isolated by utilizing electromagnetism, and the whole design is simple, clear, safe and reliable.

(3) The portable box body structure has the advantages that the detection panel, the processing circuit and the power circuit are packaged in the same box body, an internal circuit can be well protected, safety and reliability are realized, the size of the box is small, and the portable box body structure is portable and flexible.

Drawings

FIG. 1 shows a box structure of the engine failure detector of the present invention;

FIG. 2 is an exploded view of the engine failure detector of the present invention;

FIG. 3 is a system measurement and control panel of the present invention;

FIG. 4 is a block diagram of the engine fault detector system of the present invention;

FIG. 5 is a circuit diagram of the connection between the single chip module and the display screen and the control keys;

fig. 6 is the utility model discloses a schematic diagram of wireless transmission module through USART port and MCU circuit.

Detailed Description

The present invention will be further described with reference to the accompanying drawings and specific embodiments.

As shown in fig. 1 and 2, a multifunctional portable engine fault detector comprises a system fault detection and display module, a power control module and a portable box body, wherein the power control module and the system fault detection and display module are arranged in the portable box body; the power supply control module is used for externally connecting a storage battery for testing power supply, starting a motor through a starting motor module connected with an engine for igniting the generator and controlling the on-off state of a power supply;

the portable box body comprises a packaging portable box 1, a system detection panel 2 and a bottom layer electromagnetic relay fixing panel 3; the detection panel, the electric wire and the electronic component of the system required for detection are all packaged in the portable packaging box 1, so that the portable packaging box is convenient to carry and test; the system detection panel is used for realizing the control function of the tester on the engine and the display function of feedback data of a sensor arranged in the engine; bottom electromagnetic relay fixed panel 3 is used for placing power control module's electromagnetic relay 4 and the wiring at detection panel back, and electromagnetic relay 4 is fixed on the bottom panel, and bottom panel four corners sets up four spinal branch daggers in this embodiment and is used for fixed system to detect the panel. Four corners of the system detection panel 2 are fixed on four supporting columns at the bottom by 4 hexagonal nuts and 4 spring vibrating sheets.

The fixed panel of the bottom layer electromagnetic relay in the implementation is 0.5 cm-1 cm away from the bottom of the box. The bottom layer electromagnetic relay fixing panel is fixed by screws at the bottom of the box, the bottom layer panel is fixed firstly, and then the bottom layer panel is extended by 10 cm-15 cm and used as four support columns for fixing the top system detection panel.

In the embodiment, the whole packaging portable box 1 is of a cubic structure, is made of light-weight, firm and anti-falling special plastics and is used for protecting an internal system detection panel 2 and an electromagnetic relay fixing bottom plate 3; the packaging portable box is of a cubic structure with the length of 20-40 cm, the width of 10-30 cm and the height of 10-30 cm. The length of box design in this embodiment is 35cm, and the width is 25cm, and the height is 15cm, and the light portable of overall design.

As shown in fig. 3, the system measurement and control panel is used for fixing a system fault detection and display module, a shutdown key 6, a DPF manual regeneration key 7, an accelerator adjustment key 8 and a display screen 5 of the display module, which are used for controlling the single chip microcomputer module, an engine ignition starting terminal 12, a power supply positive and negative terminal 10, a starting button 9 and a switch button 13 of the power supply control module, and a CAN bus interface 11;

as shown in fig. 4, the system fault detection and display module includes a single chip module and a screen display module.

The single chip microcomputer Module is connected with an Engine Control Module (ECM) through a CAN bus and is connected with a screen display Module through a DuPont line; the screen display module comprises a display screen, and data received by the built-in MCU are displayed on the display screen in real time;

the shutdown key is pressed to send an MCU level signal, and the engine is controlled to be shut down through a CAN bus after being processed by the MCU; after the DPF breaks down during automatic regeneration, pressing a DPF manual regeneration key to enable the MCU to send an instruction to an Engine Control Module (ECM) for manual DPF regeneration; the size of an accelerator driven by an actual vehicle is simulated by pressing an upper accelerator adjusting button and a lower accelerator adjusting button, so that the pressure of the accelerator of an engine can be detected;

the CAN bus data interface is used for direct communication between the engine and the detector, the engine ECM is connected with the data interface to transmit relevant parameters to the MCU built in the singlechip module and display the parameters on the display screen in real time, the MCU compares the received data with parameter threshold values set by a program, the MCU CAN display characters on the display screen to give an alarm for the parameters exceeding the threshold values, meanwhile, a stop button, a DPF manual regeneration button and an accelerator adjustment button are arranged, the corresponding buttons are pressed down, and after the processing of the MCU by means of the connection of the data interface, the engine is controlled by relevant functions.

The MCU is connected with the upper computer, and the stored data are transmitted to the upper computer to realize further fault analysis.

The connection circuit of the MCU, the display screen and the control keys arranged in the single chip microcomputer is shown in fig. 5, and real-time display of data on the screen can be realized by controlling each IO port connected with the display screen and the MCU; one end of the control key is connected with an IO port of the MCU, the other end of the control key is grounded, the key is pressed down, and the MCU makes a corresponding response after detecting a low level through the IO port; the MCU is externally connected with an EEPROM chip for data storage; in addition, the circuit reserves an SWD program burning port, so that the program updating function is convenient to upgrade, and simultaneously reserves a USART serial port which can be connected to a computer terminal to read data stored in the EEPROM to realize further fault analysis.

The electromagnetic relay control end fixed on the bottom panel is connected with the starting button and the power supply cathode, the controlled end is connected with the power supply anode and the starting motor and is normally in a disconnected state, the power supply supplies power after the switch button is pressed, and then when the starting button is pressed, the electromagnetic relay controls the controlled end to be closed and the motor is started.

As shown in fig. 6, this is a circuit diagram that BLE4.0 low-power consumption high-speed bluetooth transmission module is connected with MCU through the USART port, and through bluetooth wireless transmission, engine fault detector can pass to the host computer with the data that detects before and keep, realizes further fault analysis.

When the detector works, the positive and negative terminals of a power supply of the detector are connected to the positive and negative ends of the storage battery for power supply connection; connecting the starting binding post and the negative binding post to a starting motor of an engine to carry out ignition starting connection; a data line is used for connecting a CAN bus data interface of the detector and a data interface of the engine for data transmission; the USART serial port can be directly connected with an upper computer for data transmission, and can also be used as an interface of the wireless transmission module for data transmission in a wireless communication mode.

The utility model discloses a specific working method is: after the circuit connection is finished, a switch button is pressed, power supply is conducted, at the moment, a starting button is pressed to enable an electromagnetic relay to be closed, a starting motor of the engine is ignited and started, then the engine starts to work, then various sensors on the engine carry out data monitoring, ECM of the engine collects data of the sensors and outputs the data to an external display device through a data line, a detector connected with the engine reacts in real time according to the received data at the moment, parameters such as an engine rotating speed value, an engine oil pressure value, a fuel oil pressure value, a water temperature value, a supercharging temperature value, a fuel oil temperature value and DPF conditions are displayed on a screen in real time, after certain parameters exceed a set threshold value, corresponding positions on the screen send warnings, the data are stored in an EEPROM chip at the same time of detection, the detector is connected with a computer end in a USART serial port communication or wireless communication mode after the detection is finished, and the stored data are read to carry out more detailed analysis.

In the embodiment, an STM32F103T series single chip microcomputer is used, and the single chip microcomputer with higher selective price ratio is used as the MCU of the detector on the premise of meeting design requirements and realizing related functions; the screen can select a relatively cheap dot matrix liquid crystal display screen due to the consideration of the cost problem, and the selection size of the screen cannot be too small because a plurality of parameters need to be displayed simultaneously; the EEPROM is a power-off storage chip, a proper chip is selected according to the size of the required storage data volume, and the AT24C02 chip is selected for testing in the implementation; the CAN bus driving chip is used for connecting the CAN bus interface with the MCU for high-speed data transceiving, and only a proper chip is selected, and the TJA1050 chip is selected in the implementation. Wireless transmission module can select modes such as bluetooth transmission, WIFI transmission, ZIGBEE transmission, combines to use the function that the scene and required realization were realized, and what this embodiment chose for use is BLE4.0 low-power consumption high rate bluetooth transmission module, and transmission rate is high, the low-power consumption, transmission distance is far away, and the cost is lower. The chips used in this embodiment are only used for this test, but are not limited to these chips, and the chips that can meet the requirements can be selected as appropriate.

While the present invention has been particularly shown and described with reference to the preferred embodiments, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention.

Claims

1. The multifunctional portable engine fault detector comprises a system fault detection and display module, a power supply control module and a portable box body; the power supply control module and the system fault detection and display module are all arranged in the portable box body; the power supply control module is used for externally connecting a storage battery for testing power supply, starting a motor through a starting motor module connected with an engine for igniting the generator and controlling the on-off state of a power supply; the system fault detection and display module is used for realizing a control detection function of an engine control module ECM and a display function of feedback data of an engine built-in sensor;

the method is characterized in that: the portable box body comprises a packaging portable box, a system measurement and control panel and a bottom layer electromagnetic relay fixing panel; the portable packaging box is used for packaging a system measurement and control panel, wires and electronic components required by detection into the box body; the system measurement and control panel is used for fixing a system fault detection and display module, a shutdown key for controlling the single chip microcomputer module, a DPF manual regeneration key, an accelerator adjustment key and a display screen of the display module, and fixing an engine ignition starting binding post, a power supply positive and negative binding posts, a starting button, a switch button and a CAN bus interface of the power supply control module; the system comprises a bottom layer electromagnetic relay fixing panel, a power supply control module, a system detection panel and a power supply control module, wherein the bottom layer electromagnetic relay fixing panel is used for placing an electromagnetic relay of the power supply control module and wiring among the modules;

the system fault detection and display module comprises a singlechip module and a screen display module; the single chip microcomputer module is connected with an engine control module ECM through a CAN bus and is connected with a screen display module through a DuPont line; the screen display module comprises a display screen, and data received by the built-in MCU are displayed on the display screen in real time;

the power supply control module comprises an engine ignition starting binding post, power supply positive and negative binding posts, a starting button, a switch button and an electromagnetic relay; the engine ignition starting wiring terminal is connected to a starting motor of the engine, the positive and negative wiring terminals of the power supply are externally connected with the storage battery, the control end of the electromagnetic relay is connected with the starting button and the negative electrode of the power supply, and the controlled end of the electromagnetic relay is connected with the positive electrode of the power supply and the starting motor.

2. The multi-functional portable engine fault detector of claim 1, characterized in that: the single chip microcomputer module comprises an MCU, a key reset device, an SWD interface, a USART serial port, a CAN bus driving chip and an external electrically erasable programmable read-only memory EEPROM.

3. The multi-functional portable engine fault detector of claim 2, characterized in that: the SWD interface is led out for program burning, and the program can be updated for function upgrading at the later stage; the USART serial port is directly connected with an upper computer for data transmission, and meanwhile, the serial port can be connected with the wireless module for function expansion and used for wireless transmission of data; the CAN bus driving chip is used for connecting the CAN bus interface with the MCU for high-speed data transceiving.

4. The multi-functional portable engine fault detector of claim 1, characterized in that: the single chip microcomputer module is a 51 series single chip microcomputer or an STM32 series single chip microcomputer.

5. The multi-functional portable engine fault detector of claim 1, characterized in that: the screen display module adopts a dot matrix liquid crystal display screen, a TFT LCD display screen or an OLED display screen.

6. The multi-functional portable engine fault detector of claim 1, characterized in that: the CAN bus data interface adopts a universal nine-hole CAN bus connector.

7. The multi-functional portable engine fault detector of claim 1, characterized in that: the packaging portable box is made of light-weight, firm and anti-falling plastic.

8. The multi-functional portable engine fault detector of claim 1, characterized in that: the electromagnetic relay is fixed on the electromagnetic relay fixing panel through screws and nuts.