Intelligent diagnosis type airtight performance detection device for protective airtight door

Abstract

The invention, which relates to the technical field of protective air-tight door detection, discloses an intelligent diagnosis type protective air-tight door air-tight performance detection device comprising a base, the upper end of the base is provided with a supporting assembly, the supporting assembly is provided with a controller and a searchlight, and the upper end of the supporting assembly is provided with a limiting assembly. An auxiliary assembly is arranged on the right side of the upper end of the base, a detection assembly is arranged on the left side of the upper end of the base, a closed space is formed between the closed door body and the shell, then gas in the gas storage tank is conveyed into the closed space, and at the moment, a pressure sensor monitors pressure changes in the closed space in real time and transmits data to a controller; when leakage is detected, a proper amount of smoke is filled into the closed space through the smoke generator, after a period of time, the smoke escapes from the leakage position, a visible smoke track can be formed in cooperation with the searchlight, the leakage position can be displayed, and therefore detection and maintenance by workers are facilitated.

Description

Technical Field

[0001] This invention relates to the field of protective airtight door testing technology, specifically to an intelligent diagnostic protective airtight door airtight performance testing device. Background Technology

[0002] Protective airtight doors are special-purpose doors, mainly used in civil defense projects, underground buildings, nuclear facilities, and other places. Their airtightness is directly related to the safety of the project and is a key barrier against the intrusion of toxic and harmful gases, the spread of nuclear radiation, and the spread of fire smoke. Therefore, protective airtight doors need to be tested for airtightness after installation.

[0003] Currently, most methods for testing protective airtight doors use the pressure decay method. While this method can determine if a leak exists, it cannot accurately locate the leak, causing significant problems for subsequent maintenance. Furthermore, the lack of effective visualization methods for leak location detection not only affects the accuracy of the test results but also leads to lengthy testing times. Therefore, an intelligent diagnostic protective airtight door airtightness testing device is proposed to address the aforementioned issues. Summary of the Invention

[0004] To address the aforementioned technical problems, an intelligent diagnostic testing device for the airtightness performance of protective airtight doors is provided. This technical solution solves the problem mentioned in the background art: currently, most testing methods for protective airtight doors use the pressure decay method, which can determine whether a leak exists, but cannot accurately locate the leak, thus causing significant trouble for subsequent maintenance work. Furthermore, the lack of effective visualization methods when detecting the leak location not only affects the accuracy of the test results but also leads to a long testing time.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: An intelligent diagnostic airtight door airtightness performance testing device includes a base, a support component at the upper end of the base, a controller and a spotlight on the support component, a limiting component at the upper end of the support component, an auxiliary component on the upper right side of the base, a detection component on the upper left side of the base, a placement component at the upper end of the base and below the limiting component, and an airtight door body placed on the upper end of the placement component.

[0006] The placement assembly includes a housing, the lower end of which is fixedly connected to the upper end of the base. A support plate is installed on the upper part of the inner sidewall of the housing, and the upper end of the support plate is tightly fitted to the lower end of the airtight door body. A pressure sensor is installed inside the housing.

[0007] Preferably, the auxiliary component includes a smoke generator, which is located at the upper end of the base and the rear of the housing, and the output end of the smoke generator is connected to a pipe.

[0008] Preferably, the rear end of the housing is connected to a second pipe, and a third pipe is provided behind the second pipe. A solenoid valve is installed between the third pipe and the second pipe, and a flexible hose is connected between the third pipe and the first pipe.

[0009] Preferably, the detection component includes a gas storage tank, which is located at the upper end of the base and to the left of the smoke generator, and the output end of the gas storage tank is connected to a pipe.

[0010] Preferably, the rear end of the housing is connected to a pipe six, and a pipe five is provided behind the pipe six. A solenoid valve two is installed between the pipe five and the pipe six, and a flexible hose two is connected between the pipe five and the pipe four.

[0011] Preferably, the support assembly includes two side plates, which are respectively installed on the left and right sides of the upper end of the base. The right end of the right side plate is connected to the left end of the controller, and the left end of the right side plate is connected to the right end of the searchlight.

[0012] Preferably, a limiting groove is formed on the inner side of both side plates, a limiting rod is installed inside the limiting groove, and a contact switch is installed on the right side of the left side plate.

[0013] Preferably, the limiting component includes a top plate, the lower left and right sides of which are fixedly connected to the lower ends of two side plates respectively.

[0014] Preferably, a hydraulic cylinder is installed at the lower end of the top plate, and the output end of the hydraulic cylinder extends through to the bottom of the top plate and is connected to a lifting plate. Limiting plates are connected to both the left and right ends of the lifting plate. The limiting plates slide on the outer surface of the limiting rod, and a contact rod is installed below the left limiting plate.

[0015] Preferably, the lower left and right sides of the lifting plate are connected to connecting rods, the lower ends of the two connecting rods are connected to connecting plates, a reinforcing plate is connected between the two connecting plates, and fastening rods are installed on the front and rear sides of the lower end of the connecting plate.

[0016] The beneficial effects of this invention compared to the prior art are: A sealed space is formed between the airtight door body and the shell. Gas from the gas storage tank is then transported into this sealed space. At this time, the pressure sensor monitors the pressure changes in the sealed space in real time and transmits the data to the controller. When a leak is detected, an appropriate amount of smoke is injected into the sealed space through a smoke generator. After a period of time, the smoke will escape from the leak. With the help of a searchlight, a visible smoke trail can be formed, which can show the location of the leak, thus facilitating the detection and maintenance by the staff. Attached Figure Description

[0017] Figure 1 This is a three-dimensional structural diagram of the present invention; Figure 2 This is a three-dimensional structural schematic diagram from another perspective in this invention; Figure 3 This is a schematic diagram of the structure by which the limiting component secures the airtight door body in this invention; Figure 4 This is a schematic diagram of the structure of the limiting component fastening the airtight door body in this invention from another perspective; Figure 5 This is a schematic diagram of the structure in which the components are placed in this invention; Figure 6 This is a schematic diagram of the structure of the sealing door body in this invention; Figure 7 This is a schematic diagram of the auxiliary component in this invention; Figure 8 This is a schematic diagram of the detection component in this invention; Figure 9 This is a schematic diagram of the structure of the support component and the limiting component in this invention; Figure 10 This is a schematic diagram of the structure of the lifting plate in this invention.

[0018] The numbers on the map are: 100. Base; 200. Support assembly; 201. Side plate; 202. Limiting groove; 203. Limiting rod; 204. Contact switch; 300. Controller; 400. Limiting assembly; 401. Top plate; 402. Hydraulic cylinder; 403. Lifting plate; 404. Limiting plate; 405. Contact rod; 406. Connecting rod; 407. Connecting plate; 408. Fastening rod; 409. Reinforcing plate; 500. Auxiliary components; 501. Smoke generator; 502. Pipeline 1; 503. Pipeline 2; 504. Solenoid valve 1; 505. Pipeline 3; 506. Hose 1; 600. Detection Components; 601. Gas Storage Tank; 602. Pipeline Four; 603. Solenoid Valve Two; 604. Pipeline Five; 605. Hoses Two; 606. Pipeline Six; 700. Component placement; 701. Housing; 702. Support plate; 703. Pressure sensor; 800. Airtight door body; 900. Searchlight. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. This description is intended to disclose the present invention so that those skilled in the art can implement it. Furthermore, the embodiments described are merely examples, and the present invention can be implemented in other ways different from those described herein. Example 1

[0020] Reference Figures 1-10 As shown, the intelligent diagnostic protective airtight door airtightness performance testing device includes a base 100, a support component 200 at the upper end of the base 100, a controller 300 and a spotlight 900 on the support component 200, a limit component 400 at the upper end of the support component 200, an auxiliary component 500 at the upper right side of the base 100, a detection component 600 at the upper left side of the base 100, and a placement component 700 at the upper end of the base 100 and below the limit component 400. The airtight door body 800 is placed on the upper end of the placement component 700.

[0021] Reference Figure 1 , Figure 3 and Figure 4 As shown, the placement component 700 includes a housing 701, the lower end of which is fixedly connected to the upper end of the base 100. A support plate 702 is installed on the upper part of the inner side wall of the housing 701. The upper end of the support plate 702 is tightly fitted to the lower end of the airtight door body 800. A pressure sensor 703 is installed inside the housing 701.

[0022] Furthermore, 800 is equipped with a sealing gasket. During testing, 800 is placed on 700, with the side equipped with the sealing gasket abutting against the upper end of 702 in 700, thereby forming a closed space between 800 and 701. 702 is installed on the upper part of the inner wall of 701, but the upper end of 702 is still inside 701.

[0023] When the gas introduced causes the pressure in the enclosed space to reach a relatively stable state, the pressure value measured by the pressure sensor 703 is the initial pressure. The initial pressure value is an important benchmark for determining whether there is a leak.

[0024] The pressure in the enclosed space where a well-sealed protective airtight door is located should be relatively stable. If there is a leak, the pressure will gradually decrease as the gas escapes. If the protective airtight door has good sealing performance, the pressure will have a certain normal fluctuation range, but the overall pressure should be relatively stable. The data collected by the pressure sensor 703 fluctuates within this normal range, indicating that there is no obvious gas leakage.

[0025] The pressure sensor 703 transmits the pressure data it monitors in real time to the controller 300. The controller 300 determines whether there is a problem with the airtightness of the protective airtight door based on the preset pressure change standard and the magnitude of the pressure drop within a specific time.

[0026] Reference Figure 7 As shown, the auxiliary component 500 includes a smoke generator 501, which is located at the upper end of the base 100 and the rear of the housing 701. The output end of the smoke generator 501 is connected to a pipe 502, and the rear end of the housing 701 is connected to a pipe 503. A pipe 505 is located behind the pipe 503. A solenoid valve 504 is installed between the pipe 505 and the pipe 503. A flexible hose 506 is connected between the pipe 505 and the pipe 502.

[0027] Furthermore, after the smoke produced by 501 is transported to the enclosed space, it will escape from the leak location of 800 along with the leaking gas, forming a visible smoke trail. With the lighting of 900, the staff can intuitively observe the location of the smoke escape, thereby accurately locating the leak point of 800 and providing location information for subsequent maintenance.

[0028] The powerful light emitted by the Searchlight 900 can illuminate the escaping smoke, enhancing its visual visibility and allowing staff to more clearly observe the subtle flow and location of the smoke.

[0029] Reference Figure 8 As shown, the detection component 600 includes a gas storage tank 601, which is located at the upper end of the base 100 and to the left of the smoke generator 501. The output end of the gas storage tank 601 is connected to a pipe 602, and the rear end of the housing 701 is connected to a pipe 606. A pipe 604 is located behind the pipe 606. A solenoid valve 603 is installed between the pipe 604 and the pipe 606, and a flexible hose 605 is connected between the pipe 604 and the pipe 602.

[0030] Furthermore, both ends of the second hose 605 in the detection component 600 and the first hose 506 in the auxiliary component 500 are equipped with rotary joints. Since the smoke generator 501 and the gas storage tank 601 are not fixed to the upper end of the base 100 and can move, during the detection, the fourth pipe 602 and the fifth pipe 604 are connected through the rotary joints on the second hose 605 and the first hose 506, and the first pipe 502 and the third pipe 505 are connected.

[0031] The gas supplied by the gas storage tank 601 keeps the enclosed space under positive pressure and has a certain airflow and pressure distribution. When smoke is injected, the flow of these gases can help the smoke to spread better in the space and escape through the leak point, so that the smoke can be discharged from the leak point more quickly and obviously, forming a clearer smoke trail, which makes it easier for staff to observe and locate the leak location. Example 2

[0032] Based on the above embodiment one, referring to Figure 1 and Figure 9 As shown, the support assembly 200 includes two side plates 201, which are respectively installed on the left and right sides of the upper end of the base 100. The right end of the right side plate 201 is connected to the left end of the controller 300, and the left end of the right side plate 201 is connected to the right end of the searchlight 900. Limiting grooves 202 are provided on the inner side of both side plates 201, and limiting rods 203 are installed inside the limiting grooves 202. A contact switch 204 is installed on the right side of the left side plate 201.

[0033] Furthermore, the contact switch 204 is located directly below the contact rod 405. The two limiting plates 404 move up and down inside the limiting groove 202, and the limiting plates 404 slide on the outer surface of the limiting rod 203, so that the lifting plate 403 moves along a fixed path, so that the contact rod 405 can accurately contact the contact switch 204. When the contact rod 405 contacts the contact switch 204, the fastening rod 408 abuts against the upper end of the airtight door body 800.

[0034] Reference Figure 9 and Figure 10As shown, the limiting assembly 400 includes a top plate 401. The lower left and right sides of the top plate 401 are fixedly connected to the lower ends of two side plates 201, respectively. A hydraulic cylinder 402 is installed at the lower end of the top plate 401. The output end of the hydraulic cylinder 402 extends through to the bottom of the top plate 401 and is connected to a lifting plate 403. Limiting plates 404 are connected to both the left and right ends of the lifting plate 403. The limiting plates 404 slide on the outer surface of the limiting rod 203. A contact rod 405 is installed below the left limiting plate 404. Connecting rods 406 are connected to both the lower left and right sides of the lifting plate 403. Connecting plates 407 are connected to the lower ends of the two connecting rods 406. A reinforcing plate 409 is connected between the two connecting plates 407. Fastening rods 408 are installed on the front and rear sides of the lower end of the connecting plate 407.

[0035] Furthermore, when applying pressure to tighten the airtight door body 800, if the fastening rod 408 directly contacts the door, the concentrated pressure may cause scratches, wear, or even deformation on the surface of the airtight door body 800. Therefore, a buffer pad is installed at the lower end of the fastening rod 408, that is, at the position where the fastening rod 408 contacts the airtight door body 800. The buffer pad is made of rubber, which is soft and elastic, and can effectively disperse the pressure applied by the fastening rod 408, avoiding pressure concentration at a local point. This prevents mechanical damage such as scratches and dents from appearing on the surface of the airtight door body 800, and protects the integrity and appearance quality of the airtight door body 800.

[0036] It should be noted that the electrical equipment described above is an existing product. Based on the actual usage scenario, corresponding preset values ​​are set, etc. This design focuses on using existing electrical appliances in combination with specific structures to accurately locate the leakage location, thereby facilitating subsequent maintenance and increasing effective visualization methods.

[0037] The hardware configuration and electrical connections of the control system: The controller 300 is the central processing unit of this device, which can be a programmable logic controller (PLC), an industrial microcontroller system, or an embedded microprocessor. The controller 300 has built-in memory, input / output (I / O) interfaces, and necessary signal processing circuits.

[0038] The input signal connection of the controller 300 is electrically connected to the pressure sensor 703 and the contact switch 204. The pressure sensor 703 monitors the pressure value of the enclosed space inside the housing 701 in real time and transmits the analog or digital pressure signal to the controller 300. The contact switch 204 is triggered when the contact rod 405 is in contact, sending a switching signal to the controller 300.

[0039] The output control connection of the controller 300 is electrically connected to various actuators via corresponding drive circuits (such as relays, solid-state relays, or solenoid valve drive modules), including: Hydraulic cylinder 402: Controls its extension and retraction to drive the lifting plate 403 and fastening rod 408 to move up and down. Solenoid valve 504 and solenoid valve 603: Control their opening and closing to control the flow of smoke and detection gas respectively. Smoke generator 501: Controls its start and stop. Outlet valve of gas storage tank 601: (If electrically controlled) Controls the supply of detection gas. Searchlight 900: Controls its on and off operation.

[0040] Detailed Description of Control Logic and Workflow: The controller (300) operates according to the following preset logic program to achieve intelligent diagnosis: Automatic door fastening and sealing cavity establishment. After the operator places the airtight door body 800 on the support plate 702, the detection program is started. The controller 300 outputs a command to start the hydraulic cylinder 402 to extend, driving the lifting plate 403 to descend. During the descent, the limit plate 404 slides along the limit rod 203 to ensure the movement trajectory. When the left contact rod 405 touches and activates the contact switch 204, the contact switch 204 sends a position signal to the controller 300. After receiving the position signal, the controller 300 immediately stops the hydraulic cylinder 402. At this time, the fastening rod 408 has applied a preset and stable clamping force to the airtight door body 800 through the buffer pad, ensuring that a preliminary seal is formed between it and the support plate 702, thus forming a closed space to be tested together with the housing 701.

[0041] After the initial pressure increase and sealing performance diagnosis are completed, the controller 300 sends a command to open the outlet valve of solenoid valve 603 and gas storage tank 601, while continuously reading data from pressure sensor 703. Gas is detected filling the enclosed space, and the pressure rises. The controller 300 monitors the pressure value in real time. When the pressure reaches the preset initial stable pressure value P0 (which can be preset according to the door specifications) and remains within the allowable error range for a period of time (e.g., t1 seconds), the controller 300 determines that the pressure increase is complete, records the pressure P0 at this time as the baseline value, and closes solenoid valve 603 and the gas supply valve. The controller 300 enters the pressure holding monitoring stage, continuously collecting data from pressure sensor 703 within the preset diagnosis time t2. The sealing performance is judged using an internal algorithm (e.g., calculating the pressure drop rate ΔP / Δt per unit time): If the pressure drop value ΔP is less than or equal to the preset leakage threshold ΔP_threshold, the controller 300 determines that the sealing performance is "qualified," outputs the result through the connected display, indicator light, or communication interface, and directly enters the end process. If ΔP is greater than ΔP_threshold, the controller 300 determines that "a leak exists" and automatically triggers the next stage of the leak location process. Third stage: Leak point location. After determining that a leak exists, the controller 300 first ensures that solenoid valve 603 is in the closed state. The above are preset values ​​that can be selected according to the specific scenario.

[0042] Subsequently, the controller 300 performs the following operations in sequence: a. Activates the searchlight 900 to provide illumination for the observation area. b. Opens the solenoid valve 504. c. Activates the smoke generator 501. Driven by the pressure difference and the flowing gas, the smoke flows towards the leak point and escapes from the gap. Under the illumination of the searchlight 900, personnel can clearly observe whether there is visible smoke escaping around the sealing surface of the sealed door body 800, thereby accurately locating the leak point. After the preset smoke observation time, the controller 300 shuts off the smoke generator 501 and the solenoid valve 504, and the detection process ends.

[0043] The safety and interactive design controller 300 can integrate a human-machine interface for setting pressure thresholds, time parameters, start / stop detection, and displaying real-time pressure curves and final diagnostic results. The system may include an emergency stop button; this button signal is connected to the controller 300, allowing for an emergency stop of all actions at any stage to ensure safety. Specifically, the contact switch 204, hydraulic cylinder 402, smoke generator 501, solenoid valve one 504, solenoid valve two 603, pressure sensor 703, and searchlight 900 are all electrically connected to the controller 300.

[0044] The usage process and working principle of this invention are as follows: In use, the airtight door body 800 is placed on top of the support plate 702 in the placement assembly 700. At this time, the airtight door body 800 is embedded between the housing 701 and the support plate 702, thus forming a closed space between the airtight door body 800 and the housing 701. Then, the controller 300 controls the hydraulic cylinder 402 to move the lifting plate 403 downwards, thereby moving the four fastening rods 408 below the lifting plate 403 downwards. When the contact rod 405 at the lower end of the left limit plate 404 contacts the contact switch 204... The contact switch 204 sends a signal to the controller 300. After receiving the signal, the controller 300 closes the hydraulic cylinder 402. At this time, the lower ends of the four fastening rods 408 contact the four corners of the upper end of the airtight door body 800, thereby keeping the contact position between the airtight door body 800 and the support plate 702 tight. Then, the controller 300 controls the solenoid valve 603 and the valve on the gas storage tank 601 to open. The gas inside the gas storage tank 601 is transported to the enclosed space through the pipe 602, the hose 605, the pipe 604, and the pipe 606.

[0045] Meanwhile, the pressure sensor 703 installed inside the housing 701 monitors the pressure changes in the enclosed space in real time and transmits the data to the controller 300. The controller 300 analyzes the pressure data according to the preset pressure change threshold to determine whether there is a leak. If the pressure drops within the set time without exceeding the threshold, the sealing performance is considered good. If the pressure exceeds the threshold, a leak is determined, and the leak location search phase begins.

[0046] When a leak is detected, the controller 300 activates the searchlight 900, simultaneously closing the solenoid valve 603 and the valve on the gas storage tank 601. Then, the smoke generator 501 is activated and the solenoid valve 504 is opened. At this time, smoke enters the enclosed space through pipe 502, hose 506, pipe 505, and pipe 503. Under the illumination of the searchlight 900, the staff observes the surface of the sealed door body 800. The location where the smoke escapes is the leak point, which is then marked for subsequent handling.

[0047] After the test is completed, the smoke generator 501 and solenoid valve 504 are controlled by the controller 300 to record the test data and results. Then the device is cleaned to prepare for the next test.

[0048] The above description, in conjunction with specific embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, several simple deductions or substitutions can be made without departing from the concept of the present invention, and all such deductions or substitutions should be considered to fall within the scope of protection defined by the claims submitted herein.

Claims

1. An intelligent diagnostic airtight door airtightness performance testing device, comprising a base (100), characterized in that: The upper end of the base (100) is provided with a support component (200), the support component (200) is provided with a controller (300) and a spotlight (900), the upper end of the support component (200) is provided with a limiting component (400), the upper right side of the base (100) is provided with an auxiliary component (500), the upper left side of the base (100) is provided with a detection component (600), the upper end of the base (100) and the lower part of the limiting component (400) are provided with a placement component (700), and the upper end of the placement component (700) is provided with a sealed door body (800). The placement assembly (700) includes a housing (701), the lower end of which is fixedly connected to the upper end of the base (100). A support plate (702) is installed on the upper part of the inner side wall of the housing (701), and the upper end of the support plate (702) is tightly fitted to the lower end of the airtight door body (800). A pressure sensor (703) is installed inside the housing (701).

2. The intelligent diagnostic protective airtight door airtightness performance testing device according to claim 1, characterized in that: The auxiliary component (500) includes a smoke generator (501), which is located at the upper end of the base (100) and behind the housing (701). The output end of the smoke generator (501) is connected to a pipe (502).

3. The intelligent diagnostic protective airtight door airtightness performance testing device according to claim 1, characterized in that: The rear end of the housing (701) is connected to a second pipe (503), and a third pipe (505) is provided behind the second pipe (503). A solenoid valve (504) is installed between the third pipe (505) and the second pipe (503), and a flexible hose (506) is connected between the third pipe (505) and the first pipe (502).

4. The intelligent diagnostic protective airtight door airtightness performance testing device according to claim 1, characterized in that: The detection component (600) includes a gas storage tank (601), which is located at the upper end of the base (100) and to the left of the smoke generator (501). The output end of the gas storage tank (601) is connected to a pipe (602).

5. The intelligent diagnostic protective airtight door airtightness performance testing device according to claim 1, characterized in that: The rear end of the housing (701) is connected to a pipe six (606), and a pipe five (604) is provided behind the pipe six (606). A solenoid valve two (603) is installed between the pipe five (604) and the pipe six (606), and a flexible hose two (605) is connected between the pipe five (604) and the pipe four (602).

6. The intelligent diagnostic protective airtight door airtightness performance testing device according to claim 1, characterized in that: The support assembly (200) includes two side plates (201), which are respectively installed on the left and right sides of the upper end of the base (100). The right end of the right side plate (201) is connected to the left end of the controller (300), and the left end of the right side plate (201) is connected to the right end of the searchlight (900).

7. The intelligent diagnostic protective airtight door airtightness performance testing device according to claim 6, characterized in that: Both side plates (201) have a limiting groove (202) on their inner sides. A limiting rod (203) is installed inside the limiting groove (202). A contact switch (204) is installed on the right side of the left side plate (201).

8. The intelligent diagnostic protective airtight door airtightness performance testing device according to claim 1, characterized in that: The limiting component (400) includes a top plate (401), the lower left and right sides of which are fixedly connected to the lower ends of two side plates (201).

9. The intelligent diagnostic protective airtight door airtightness performance testing device according to claim 8, characterized in that: A hydraulic cylinder (402) is installed at the lower end of the top plate (401). The output end of the hydraulic cylinder (402) extends through to the bottom of the top plate (401) and is connected to a lifting plate (403). Limiting plates (404) are connected to both the left and right ends of the lifting plate (403). The limiting plate (404) slides on the outer surface of the limiting rod (203). A contact rod (405) is installed below the left limiting plate (404).

10. The intelligent diagnostic protective airtight door airtightness performance testing device according to claim 9, characterized in that: The lower end of the lifting plate (403) is connected to the left and right sides of the lifting plate (406), and the lower end of the two connecting rods (406) is connected to the connecting plate (407). A reinforcing plate (409) is connected between the two connecting plates (407), and fastening rods (408) are installed on the front and rear sides of the lower end of the connecting plate (407).

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