A fresh air system housing

Abstract

The present application relates to a kind of fresh air system shell, belong to fresh air system technical field.The fresh air system shell includes outer shell, inner shell and door closing mechanism;Inner shell is set in outer shell, first access door is provided on outer shell, and inner shell is formed by at least three single bodies, and second access door is rotatably provided on single body;Door closing mechanism includes reminding component and first door closing component.The fresh air system shell provided in the present application, outer shell is covered in inner shell, and inner shell is used for installing functional unit, and door closing mechanism is used for detecting the opening and closing state of first access door and second access door, after staff completes maintenance and closes first access door, if there is still not closed second access door, alarm component can alarm, to remind staff to check, and even if staff ignores alarm information, door closing component can automatically close second access door, to ensure that first access door and second access door are closed.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of fresh air systems, and particularly relates to a fresh air system shell. BACKGROUND

[0002] In a large shopping mall, a large fresh air system is usually used, which comprises an outer shell and an inner shell. A first access door is arranged on the outer shell, and the inner shell is arranged in the outer shell. Since a plurality of functional modules, such as a rough filtering unit, a fine filtering unit, a fan unit and a sterilization unit, are to be installed in the inner shell, the large fresh air system is usually long, and the space in the outer shell is relatively narrow. Please refer to the patent with the patent number CN2019214598998 and the patent name "Dehumidifier", a plurality of second access doors are arranged in the inner shell, each of which corresponds to one or more functional modules. Generally, the number of the second access doors is more than three.

[0003] After the maintenance is completed, the first access door and the second access doors need to be closed. If the second access doors are not closed, the inner shell will leak air. Since the number of the second access doors is large, the staff may miss some of the second access doors, especially those at both ends, which will affect the normal operation of the fresh air system. SUMMARY

[0004] In view of this, the purpose of the present application is to provide a fresh air system shell. After the staff completes the maintenance and closes the first access door, if there is a second access door that has not been closed, the alarm assembly can alarm, thereby reminding the staff to check. Even if the staff ignores the alarm information, the door closing assembly can automatically close the second access door, ensuring that the first access door and the second access doors are all closed.

[0005] The technical solution of the present application is as follows:

[0006] The present application provides a fresh air system shell, which comprises an outer shell, an inner shell and a door closing mechanism. The inner shell is arranged in the outer shell, the outer shell is provided with a first access door, the inner shell is composed of at least three single bodies, and a second access door is rotatably arranged on each single body. The door closing mechanism comprises a reminding assembly and a first door closing assembly. The reminding assembly is used to detect the state of the first access door and the second access doors. When the first access door is closed and any one of the second access doors is not closed, the reminding assembly alarms. The first door closing assembly is arranged on the single body and can be triggered by the second access door that is opened by a preset angle threshold. The opened second access door is locked within a preset time threshold and is unlocked when the preset time threshold is exceeded, so that the second access door is automatically closed.

[0007] As an optional solution of the above technical scheme, the second access door is rotatably provided with a third access door and a second door closing assembly, and the rotation center lines of the second access door and the third access door both extend in the vertical direction and the opening directions of the two are opposite.

[0008] As an optional solution of the above technical scheme, the reminding assembly is further configured to detect the state of the third access door, and when the first access door is closed and any one of the second access door or the third access door is not closed, the reminding assembly alarms; the second access door is provided with a second door closing assembly, the second door closing assembly can be triggered by the third access door being opened by a preset angle threshold, the third access door being opened is locked within a preset time threshold, and is unlocked when the preset time threshold is exceeded, so that the third access door is automatically closed.

[0009] As an optional solution of the above technical scheme, the reminding assembly includes a power supply, a first switch, a plurality of second switches, a plurality of third switches and a plurality of alarm lights; the power supply, the first switch and any one of the second switch or the third switch are connected in series, the plurality of second switches and the plurality of third switches are connected in parallel and each correspondingly provided with the alarm light; the first switch is matched with the first access door, when the first access door is closed, the first switch is closed, and when the first access door is opened, the first switch is opened; the second switch is matched with the second access door, when the second access door is closed, the second switch is opened, and when the second access door is opened, the second switch is closed; the third switch is matched with the third access door, when the third access door is closed, the third switch is opened, and when the third access door is opened, the third switch is closed.

[0010] As an optional solution of the above technical scheme, the plurality of alarm lights are arranged on the outer shell and divided into two rows, the upper row of alarm lights are arranged in the order of corresponding second access doors, and the lower row of alarm lights are arranged in the order of corresponding third access doors.

[0011] As an optional solution of the above technical scheme, the reminding assembly includes a power supply, a first switch, a plurality of second switches and a plurality of alarm lights; the power supply, the first switch and any one of the second switch are connected in series, the plurality of second switches are connected in parallel and correspondingly provided with the alarm light; the first switch is matched with the first access door, when the first access door is closed, the first switch is closed, and when the first access door is opened, the first switch is opened; the second switch is matched with the second access door, when the second access door is closed, the second switch is opened, and when the second access door is opened, the second switch is closed.

[0012] As an optional solution of the above technical scheme, one end of the second access door is provided with a reset member, the reset member makes the second access door have a closing trend; the first door closing assembly comprises a trigger lever, a first reset spring, a closing circuit and a telescopic cylinder, the trigger lever is rotatably arranged on the single body and can be reset under the action of the first reset spring, and when the second access door is opened to a preset angle threshold, the trigger lever can be pushed and the closing circuit is closed, so that the telescopic cylinder is timed to extend and retract and locks or unlocks the second access door.

[0013] As an optional solution of the above technical scheme, the closing circuit comprises a trigger switch and an electromagnetic valve, the electromagnetic valve is a single-electronic-control two-position five-way electromagnetic valve, the trigger lever can make the trigger switch closed and the trigger switch can be reset to be disconnected, and the telescopic cylinder is controlled through the electromagnetic valve; when the closing circuit is powered on, the telescopic cylinder can be elongated and abut against the inner side of the second access door; after the closing circuit is powered off for a preset time threshold, the telescopic cylinder is retracted and the reset member can push the second access door to be closed.

[0014] As an optional solution of the above technical scheme, the telescopic cylinder comprises a telescopic part and a manual part, the telescopic part is provided with a telescopic cavity, one end of the manual part is provided with a sliding member, and the sliding member is slidably arranged in the telescopic cavity; the telescopic cavity is divided into a first cavity and a second cavity by the sliding member, a second reset spring is arranged in the first cavity, a one-way valve allowing airflow to flow from the first cavity to the second cavity is arranged on the sliding member, a gas leakage hole is arranged on the one-way valve, the airflow passing speed of the gas leakage hole is much smaller than that of the one-way valve, and the second reset spring makes the sliding member have a trend of moving outward.

[0015] As an optional solution of the above technical scheme, a buffer interval is arranged between the trigger lever and the telescopic cylinder, and the buffer interval has a first end and a second end; when the second access door reaches the first end, the trigger lever can be triggered, the telescopic cylinder is extended and the second end is formed; when the second access door is located at the second end, the trigger lever can be reset and the closing circuit starts timing.

[0016] The beneficial effects of the present application are:

[0017] The fresh air system shell provided by the application, the outer cover is arranged outside the inner cover, the inner cover is used for installing functional units, the door closing mechanism is used for detecting the opening and closing state of the first access door and the second access door, after the staff completes the maintenance and closes the first access door, if there is a second access door that has not been closed, the alarm component can alarm, so as to remind the staff to check, and even if the staff ignores the alarm information, the door closing component can automatically close the second access door, to ensure that the first access door and the second access door are completely closed. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed in the embodiments. Obviously, the drawings in the following description only only some embodiments of the application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative labor. Through the drawings shown, the above and other purposes, features and advantages of the application will be more clear. The same reference signs in all the drawings indicate the same parts. The drawings are not necessarily drawn in proportion to the actual size, and the emphasis is on showing the main idea of the application.

[0019] Figure 1 The structure diagram of the fresh air system shell provided by the embodiment of the application Figure One ;

[0020] Figure 2 The structure diagram of the fresh air system shell provided by the embodiment of the application Figure Two ;

[0021] Figure 3 The cooperation relationship diagram of the inner cover and the door closing mechanism of the fresh air system shell provided by the embodiment of the application Figure One ;

[0022] Figure 4 The cooperation relationship diagram of the inner cover and the door closing mechanism of the fresh air system shell provided by the embodiment of the application Figure Two ;

[0023] Figure 5 The cooperation relationship diagram of the inner cover and the door closing mechanism of the fresh air system shell provided by the embodiment of the application Figure Three ;

[0024] Figure 6 The structure diagram of the single body of the fresh air system shell provided by the embodiment of the application

[0025] Figure 7 The structure diagram of the reminding component of the fresh air system shell provided by the embodiment of the application

[0026] Figure 8A structure schematic view of a first door closing assembly of a fresh air system shell provided by an embodiment of the present application is provided.

[0027] Figure 9 A structure schematic view of a closing circuit of a fresh air system shell provided by an embodiment of the present application is provided.

[0028] Figure 10 A corresponding relationship schematic view of a solenoid valve and a telescopic cylinder of a fresh air system shell provided by an embodiment of the present application is provided.

[0029] Figure 11 A Figure 10 A partial enlarged schematic view of A part of the fresh air system shell provided by an embodiment of the present application is provided.

[0030] Fig. 10 is a structure schematic view of a fresh air system shell; Fig. 11 is a structure schematic view of an outer shell; Fig. 12 is a structure schematic view of an inner shell; Fig. 13 is a structure schematic view of a door closing mechanism; Fig. 14 is a structure schematic view of a first door closing assembly; Fig. 15 is a structure schematic view of a second door closing assembly; Fig. 16 is a structure schematic view of a closing circuit; Fig. 17 is a structure schematic view of a telescopic cylinder; Fig. 18 is a structure schematic view of a solenoid valve; Fig. 19 is a structure schematic view of a telescopic part; Fig. 20 is a structure schematic view of a manual part; Fig. 21 is a structure schematic view of a sliding part; Fig. 22 is a structure schematic view of a first cavity; Fig. 23 is a structure schematic view of a second cavity; Fig. 24 is a structure schematic view of a one-way valve; Fig. 25 is a structure schematic view of a gas leakage hole; Fig. 26 is a structure schematic view of a buffer interval; Fig. 27 is a structure schematic view of a first end; Fig. 28 is a structure schematic view of a second end; Fig. 29 is a structure schematic view of a first locking unit; Fig. 30 is a structure schematic view of a second locking unit; Fig. 31 is a structure schematic view of a reminding assembly; Fig. 32 is a structure schematic view of a power supply; Fig. 33 is a structure schematic view of a first switch; Fig. 34 is a structure schematic view of a second switch; Fig. 35 is a structure schematic view of a third switch; Fig. 36 is a structure schematic view of an alarm lamp; Fig. 37 is a structure schematic view of a first cavity; Fig. 38 is a structure schematic view of a second cavity; Fig. 39 is a structure schematic view of a one-way valve; Fig. 40 is a structure schematic view of a gas leakage hole; Fig. 41 is a structure schematic view of a buffer interval; Fig. 42 is a structure schematic view of a first end; Fig. 43 is a structure schematic view of a second end; Fig. 44 is a structure schematic view of a first locking unit; Fig. 45 is a structure schematic view of a second locking unit; Fig. 46 is a structure schematic view of a reminding assembly; Fig. 47 is a structure schematic view of a power supply; Fig. 48 is a structure schematic view of a first switch; Fig. 49 is a structure schematic view of a second switch; Fig. 50 is a structure schematic view of a third switch; Fig. 51 is a structure schematic view of an alarm lamp; Fig. 52 is a structure schematic view of a first cavity; Fig. 53 is a structure schematic view of a second cavity; Fig. 54 is a structure schematic view of a one-way valve; Fig. 55 is a structure schematic view of a gas leakage hole; Fig. 56 is a structure schematic view of a buffer interval; Fig. 57 is a structure schematic view of a first end; Fig. 58 is a structure schematic view of a second end; Fig. 59 is a structure schematic view of a first locking unit; Fig. 60 is a structure schematic view of a second locking unit; Fig. 61 is a structure schematic view of a reminding assembly; Fig. 62 is a structure schematic view of a power supply; Fig. 63 is a structure schematic view of a first switch; Fig. 64 is a structure schematic view of a second switch; Fig. 65 is a structure schematic view of a third switch; and Fig. 66 is a structure schematic view of an alarm lamp. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings can be arranged and designed in various different configurations.

[0032] Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed application, but only represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor are within the scope of protection of the present application.

[0033] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0034] Furthermore, the terms "first," "second," etc., are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0035] Please refer to Figure 1 , Figure 2 As shown, an embodiment of the present invention provides a fresh air system housing 10, which is mainly used in large-scale fresh air systems, such as those found in shopping malls and underground parking lots. Large-scale fresh air systems are typically large in size, with a height generally exceeding 2m and a length exceeding 5m. However, the fresh air system housing 10 in this embodiment can also be applied to smaller-scale fresh air systems.

[0036] In this regard, please combine Figures 1-5 As shown, the fresh air system housing 10 mainly consists of an outer housing 11, an inner housing 12, and a door closing mechanism 13. The following is a detailed description of each part.

[0037] The shape of the outer shell 11 is not limited. For example, in this embodiment, the outer shell 11 is a cuboid shell with a hollow interior. The main function of the outer shell 11 is to form a closed area so that the inner shell 12 and other items are located within the closed area, avoiding the influence of dust, debris, etc., and also preventing non-staff members from damaging the internal structure.

[0038] The outer casing 11 is usually provided with an air inlet and an air outlet at both ends. The air inlet is connected to the external pipe through a pipe joint, and the air outlet is connected to the indoor pipe through a pipe joint, or the air inlet is connected to the indoor pipe through a pipe joint, and the air outlet is connected to the external pipe through a pipe joint.

[0039] The outer shell 11 comprises an outer shell body 110 and a first inspection door 111. One side of the outer shell body 110 is an inspection side, and the inspection side is provided with a first inspection opening. The first inspection door 111 is rotatably connected to the outer shell body 110, that is, the first inspection door 111 is a swing door. The first inspection door 111 and the outer shell body 110 can be connected by a pivot shaft or a hinge, and the rotation center line of the first inspection door 111 is vertically arranged. During rotation of the first inspection door 111, the first inspection opening can be opened or closed, so that the worker can enter the outer shell body 110. Generally, after the worker completes the inspection and comes out of the outer shell body 110, the worker will close the first inspection door 111, just like everyone will close the house door when going out. In addition, even if the first inspection door 111 is forgotten to be closed, other workers can easily see it.

[0040] The first inspection door 111 has a hinged end and a movable end. The hinged end is hinged to the outer shell body 110, and the movable end can be close to or away from the outer shell body 110. A corresponding locking assembly is arranged between the movable end and the outer shell body 110. The structure of the locking assembly is not limited and can be similar to a door lock in the prior art. The locking assembly is mainly used to fix the closed first inspection door 111.

[0041] The inner shell 12 is arranged in the outer shell 11. The style of the inner shell 12 is not limited, and in this embodiment, the inner shell 12 is composed of at least three single bodies 120. Each single body 120 can accommodate a functional unit, such as a coarse filter unit, a fan unit, a fine filter unit, a sterilization unit, and a reserved blank unit. Of course, other components can also be added between adjacent two single bodies 120.

[0042] Please refer to Figure 6 The single body 120 comprises an inner shell body 121 and a second inspection door 122. One side of the inner shell body 121 is an inspection side, and the inspection side is provided with a second inspection opening. The second inspection door 122 is rotatably connected to the inner shell body 121, that is, the second inspection door 122 is a swing door. The second inspection door 122 and the inner shell body 121 can be connected by a pivot shaft or a hinge, and the rotation center line of the second inspection door 122 is vertically arranged. During rotation of the second inspection door 122, the second inspection opening can be opened or closed. When the second inspection door 122 is opened, the worker can enter the inner shell body 121 and perform inspection, replacement, etc. on the internal functional components. When the second inspection door 122 is closed, the second inspection opening is closed, and a closed interval is formed in the inner shell 12, and other components can flow in the interval according to a predetermined direction.

[0043] The second access door 122 has a hinged end and a movable end, the hinged end is hinged to the inner shell 121, and the movable end can be close to or away from the inner shell 121, and a corresponding locking assembly is arranged between the movable end and the inner shell 121, the structure of the locking assembly is not limited, which can refer to the existing technology, similar to the lock of the door, etc., mainly used for fixing the closed second access door 122.

[0044] After the inner cover 12 is placed in the outer cover 11, the reserved operation interval is relatively small, generally only enough to open the second access door 122. The second access door 122 located at both ends is usually opened in opposite directions to open towards both ends, thereby minimizing the obstruction to the workers, for example, the leftmost second access door 122 needs to be opened to the left, and the rightmost second access door 122 needs to be opened to the right, if the leftmost second access door 122 needs to be opened to the right or the rightmost second access door 122 needs to be opened to the left, the worker must stand at the end inside the outer shell 110 and may need to turn sideways to open. Since the second access door 122 on both sides is close to the end of the inner side of the outer shell 110 after being opened, it is easy to be ignored and forgotten to close, of course, the second access door 122 at other positions can also be forgotten to close.

[0045] Therefore, in the embodiment, the following solution is provided: please combine Figures 7-10 As shown in the figure, the door closing mechanism 13 includes a reminding assembly 130 and a first door closing assembly 140, wherein the reminding assembly 130 is mainly used to remind the worker that there is a second access door 122 that is not closed, and the first door closing assembly 140 is used to automatically close the second access door 122 that is not closed even if the worker ignores the reminder of the reminding assembly 130. Among them, the first door closing assembly 140 is the last line of defense, generally speaking, as long as the reminding assembly 130 alarms, the worker needs to manually close the corresponding second access door 122 and lock the locking assembly.

[0046] The reminding assembly 130 is used to detect the state of the first access door 111 and the second access door 122, which is usually divided into the following cases: the first access door 111 is closed, and all the second access doors 122 are closed; the first access door 111 is closed, and part or all of the second access doors 122 are not closed. In the first case, the reminding assembly 130 does not alarm; in the second case, the reminding assembly 130 needs to alarm to prompt the worker that there is a second access door 122 that is not closed.

[0047] In the embodiment, the structure of the reminding assembly 130 can adopt but is not limited to the following technical solutions: please combine Figure 7 As shown in the figure, the reminding assembly 130 includes a power supply 131, a first switch 132, a plurality of second switches 133, and a plurality of alarm lights 135.

[0048] The first switch 132 is matched with and linked to the first access door 111. When the first access door 111 rotates, the state of the first switch 132 can be controlled, that is, when the first access door 111 is closed, the first switch 132 is closed, and when the first access door 111 is opened, the first switch 132 is opened. The first switch 132 can rotate, and the style of the first switch 132 can refer to the prior art, such as a knife switch. A first spring can be arranged on the first switch 132. The first spring can be a compression spring or a tension spring. The two ends of the first spring are respectively connected with the outer shell 110 and the first switch 132. The first spring makes the first switch 132 have a tendency to be opened. When the first access door 111 is closed, the first switch 132 can be pressed and the first spring is compressed or stretched, so that the first switch 132 is closed. When the first access door 111 is opened, the first spring pushes the first switch 132 to be opened.

[0049] The second switch 133 is matched with and linked to the second access door 122. When the second access door 122 rotates, the state of the second switch 133 can be controlled, that is, when the second access door 122 is closed, the second switch 133 is opened, and when the second access door 122 is opened, the second switch 133 is closed. The second switch 133 can rotate, and the style of the second switch 133 can refer to the prior art, such as a knife switch. A second spring can be arranged on the second switch 133. The second spring can be a compression spring or a tension spring. The two ends of the second spring are respectively connected with the inner shell 121 and the second switch 133. The second spring makes the second switch 133 have a tendency to be closed. When the second access door 122 is closed, the second switch 133 can be pressed and the second spring is compressed or stretched, so that the second switch 133 is opened. When the second access door 122 is opened, the second spring pushes the first switch 132 to be closed.

[0050] The power supply 131 can adopt an independent power supply 131 or share the power supply 131 with the fresh air system. The plurality of alarm lamps 135 correspond to the second switches 133 one by one, that is, the corresponding alarm lamps 135 are connected in series with the second switches 133. The installation positions of the alarm lamps 135 are not limited. In the embodiment, the alarm lamps 135 are arranged on the outer shell 110 or the first access door 111. The plurality of alarm lamps 135 are arranged according to the arrangement order of the corresponding second access doors 122. When the alarm lamps 135 are on, the workers only need to observe the positions of the alarm lamps 135 to know which door is not closed.

[0051] The plurality of second switches 133 are connected in parallel, and the power supply 131, the first switch 132 and any one of the second switches 133 are connected in series. The circuit after installation is as follows Figure 7As shown in the figure, only when the first switch 132 and the second switch 133 are closed, that is, the first access door 111 is opened and the second access door 122 is closed, the corresponding circuit will be connected, and this will not happen in normal operation, so the circuit is connected very few times, and the power supply 131 is less damaged. It should be noted that each second switch 133 needs to be connected in series with a load, such as a resistor, an electrical element, etc. Of course, the alarm lamp 135 can also be used as a load to prevent short circuit, which belongs to the prior art and will not be described here. In the figure, the first spring and the second spring are compression springs.

[0052] After the installation of the reminding assembly 130, when the first access door 111 is closed and part of the second access door 122 is not closed, the reminding assembly 130 can remind the staff, but the staff may still ignore it, which leads to the second access door 122 not being closed and the inner housing 12 leaking air. Therefore, in the present embodiment, the following improvement scheme is provided: the first door closing assembly 140 is arranged on the single body 120 and corresponds to the first access door 111. When the second access door 122 is opened to a certain angle, the first door closing assembly 140 starts to work and locks the opened second access door 122 within a preset time threshold, so that the second access door 122 cannot be closed, so that the staff can carry out maintenance on the functional unit within the preset time threshold; when the preset time threshold is exceeded, the first door closing assembly 140 is unlocked, and the second access door 122 can be automatically closed. Of course, the maintenance time of the staff may be greater than the preset time threshold, and during the maintenance of the staff, the second access door 122 is automatically closed or has a tendency to close, at which time the staff can reopen the second access door 122 to a preset angle threshold. In Figure 7 In the figure, the arrow at the first switch 132 represents that the first switch 132 is pressed when the first access door 111 is closed to make the first switch 132 closed, the arrow at the second switch 133 represents that the second switch 133 is pressed when the second access door 122 is closed to make the second switch 133 disconnected, the arrow at the third switch 134 represents that the third switch 134 is pressed when the third access door 124 is closed to make the third switch 134 disconnected, and only part of the second switch 133 and the third switch 134 are shown in the figure. The number of the second switch 133 and the third switch 134 can be set as needed.

[0053] Specifically, the structure of the first door closing assembly 140 can adopt but is not limited to the following scheme: please refer to Figure 8 、 Figure 9 As shown in the figure, the first door closing assembly 140 includes a trigger rod 142, a first reset spring 143, a closing circuit 144, and a telescopic cylinder 145.

[0054] The trigger lever 142 is rotatably arranged on the single body 120 and can be reset under the action of the first reset spring 143. When the second access door 122 is opened to a preset angle threshold, the trigger lever 142 can be triggered. The preset angle threshold can be set as required. In the embodiment, the preset angle threshold can be 90°, 100°, 110°, etc. After the trigger lever 142 is triggered, the closing circuit 144 can be connected. The closing circuit 144 can be timed. The telescopic cylinder 145 can be telescopic and controlled by the closing circuit 144. The telescopic cylinder 145 can lock or unlock the second access door 122.

[0055] One end of the second access door 122 is provided with a reset member 146. The reset member 146 makes the second access door 122 have a tendency to close. That is, when the telescopic cylinder 145 locks the second access door 122, the reset member 146 cannot make the second access door 122 close. After the telescopic cylinder 145 is unlocked, under the action of no external force, the reset member 146 can drive the second access door 122 to reset and close. The structure of the reset member 146 is not limited. For example, the reset member 146 adopts a torsion spring or a hydraulic hinge. The reset member 146 is arranged at the hinge joint of the second access door 122 and the inner shell 121. If the reset member 146 adopts a torsion spring, the torsion spring can be sleeved on the rotating shaft of the second access door 122 and the inner shell 121. The two ends of the torsion spring respectively abut against the second access door 122 and the inner shell 121. If the reset member 146 adopts a hydraulic hinge, the second access door 122 and the inner shell 121 can be connected through the hydraulic hinge. The hydraulic hinge has the characteristic of slow reset. In other embodiments, the reset member 146 can also adopt a compression spring, a tension spring, etc. The installation mode can refer to the prior art.

[0056] The structure of the closing circuit 144 can refer to the prior art and has the characteristics of instantaneous power-on and timed power-off. In the embodiment, the closing circuit 144 can adopt the following scheme: the closing circuit 144 includes the power supply 131, a trigger switch SB, a first resistor R1, a second resistor R2, a sliding resistor RP, a triode VT, a relay coil L, a capacitor C, and an electromagnetic valve 147, which are connected in the manner as shown in the figure. Figure 9

[0057] The trigger switch SB has a closed state and an open state. When the trigger switch SB is pressed, it can be closed. After the trigger switch SB is released, it can be opened. The specific mode can be that a spring is arranged on the trigger switch. The spring can be a tension spring or a compression spring. The spring makes the trigger switch have a tendency to open. The specifications of the first resistor R1, the second resistor R2, the sliding resistor RP, and the capacitor C can be set as required. Please refer to the figure. Figure 10 The electromagnetic valve 147 adopts a single-control two-position five-way electromagnetic valve 147. The left side of the electromagnetic valve 147 is electrically connected with the line. The right side is provided with a spring. The single-control two-position five-way electromagnetic valve 147 has the characteristics of power-on working and power-off resetting.​

[0058] When the second access door 122 presses the trigger switch SB through the trigger lever 142, the power supply 131 injects a base current to the transistor VT through the first resistor R1, the transistor VT is turned on, the collector current passes through the relay coil L, the armature is attracted to make the contact 2 closed, and the electromagnetic valve 147 is connected to the power supply 131. The electromagnetic valve 147 is powered and drives the telescopic cylinder 145 to work, and the telescopic cylinder 145 locks the second access door 122. At the same time, the power supply 131 rapidly charges the capacitor C, so that the voltage across the capacitor C is consistent with the voltage of the power supply 131.

[0059] Then, the second access door 122 releases the trigger lever 142, the trigger lever 142 no longer presses the trigger switch SB, although the trigger switch SB is disconnected, the capacitor C is discharged through a discharge circuit (another discharge circuit is composed of the second resistor R2 and the sliding resistor RP) of the E-B junction of the transistor VT and the first resistor R1, and the conduction of the transistor VT is maintained, so the electromagnetic valve 147 is still powered. The capacitor C is slowly discharged, and when the discharge current of the capacitor C is reduced to be insufficient to maintain the conduction of the transistor VT, the electromagnetic valve 147 is powered off, and the telescopic cylinder 145 is reset, and the second access door 122 is unlocked. By adjusting the sliding resistor RP, the timing time of the closing circuit 144 can be changed.

[0060] Of course, the above embodiment is only one implementation of the closing circuit 144, and in other embodiments, other circuit structures in the prior art can also be referred to.

[0061] In the embodiment, the telescopic cylinder 145 is arranged on the inner shell 121, the telescopic cylinder 145 is controlled by the electromagnetic valve 147, and the structure and working principle of the telescopic cylinder 145 and the working principle of the electromagnetic valve 147 controlling the telescopic cylinder 145 can be referred to the prior art. When the electromagnetic valve 147 is powered on, the telescopic cylinder 145 is elongated; when the electromagnetic valve 147 is powered off, the telescopic cylinder 145 is retracted. When the closing circuit 144 is closed and powered on, the telescopic cylinder 145 can be elongated and abut against the inner side of the second access door 122, the second access door 122 is blocked and cannot be closed. After the trigger lever 142 is triggered, the closing circuit 144 is powered on, then the first reset spring 143 pushes the trigger lever 142 to reset, the trigger switch SB is disconnected, and the closing circuit 144 starts timing. In this process, the electromagnetic valve 147 is always powered, and until the power is off for more than a preset time threshold, the telescopic cylinder 145 is retracted, at this time, the second access door 122 is not blocked, and the reset member 146 drives the second access door 122 to close.

[0062] In order to reset the trigger lever 142 after the second access door 122 triggers the trigger lever 142, so that the closing circuit 144 is disconnected and starts timing, in the embodiment, the following technical solutions are provided: please combine Figure 8As shown, a buffer interval 158 is arranged between the trigger lever 142 and the telescopic cylinder 145, and the buffer interval 158 has a first end 159 and a second end 160. When the second access door 122 reaches the first end 159, the trigger lever 142 can be triggered, the telescopic cylinder 145 is extended and the second end 160 is formed, at this time, the second access door 122 is released, and the reset member 146 can drive the second access door 122 to reset until the second access door 122 is blocked by the second end 160. When the second access door 122 is located at the second end 160, the trigger lever 142 can be reset, the trigger switch SB is turned off, and the closing circuit 144 starts timing. Specifically, for example, one end of the trigger lever 142 is hinged to the inner housing 121, and when the second access door 122 rotates, the trigger lever 142 can be pushed to the right, the trigger lever 142 can rotate counterclockwise, thereby pressing the trigger switch SB, the telescopic cylinder 145 is extended, and the second end 160 is formed. Then, after the second access door 122 is released, the second access door 122 is reset to abut against the second end 160 under the action of the reset member 146, and the trigger lever 142 is reset clockwise under the action of the first reset spring 143, and the trigger switch SB is turned off. Figure 8

[0063] The above technical solution makes the second access door 122 be locked within the timing time of the closing circuit 144, and after the maintenance of the staff is completed, it may not be timed out, therefore, the staff needs to manually close the second access door 122. In the embodiment, the following solutions can be used but are not limited to: the telescopic cylinder 145 includes a telescopic part 150 and a manual part 151, the telescopic part 150 can be telescopic, the telescopic part 150 has a fixed cylinder and a telescopic rod, the telescopic rod is telescopically inserted into the fixed cylinder, and the manual part 151 is movably connected with the telescopic rod. When the telescopic part 150 is extended, the manual part 151 can lock the second access door 122, and the manual part 151 can be manually controlled to unlock the second access door 122. In this way, the first door closing assembly 140 has both manual closing and automatic closing functions when the second access door 122 is forgotten to be closed. Generally, manual closing is preferred, and automatic closing is equivalent to an insurance. Of course, in other embodiments, the manual closing structure can not be provided.

[0064] When the second access door 122 is manually closed, the manual part 151 needs to be operated. If the second access door 122 is slowly closed, the staff needs to maintain the manual part 151 for a certain period of time until the second access door 122 cannot be locked even if the manual part 151 is reset. In the embodiment, the following improvement solutions are provided: please combine Figure 10 , Figure 11 ​As shown, the telescopic part 150 is provided with a telescopic cavity, one end of the manual part 151 is provided with a sliding piece 152, and the sliding piece 152 is slidably arranged in the telescopic cavity. The telescopic cavity is divided into a first cavity 153 and a second cavity 154 by the sliding piece 152. It should be noted that the total volume of the first cavity 153 and the second cavity 154 does not change when the sliding piece 152 slides, and the volumes of the first cavity 153 and the second cavity 154 can change, for example, the first cavity 153 increases and the second cavity 154 decreases, or the first cavity 153 decreases and the second cavity 154 increases.

[0065] The first cavity 153 is provided with a second reset spring 155, which can be a compression spring. The two ends of the second reset spring 155 abut against the bottom wall of the first cavity 153 and the sliding piece 152, respectively. The second reset spring 155 makes the sliding piece 152 have a tendency to move outward. Here, the outward movement of the sliding piece 152 refers to the extension of the manual part 151.

[0066] The sliding piece 152 adopts a hollow structure, and is provided with a one-way valve 156. The one-way valve 156 allows gas flow from the first cavity 153 to the second cavity 154, and is reverse blocked. The one-way valve 156 is provided with a gas leakage hole 157. The gas leakage hole 157 penetrates the one-way valve 156, and the first cavity 153 and the second cavity 154 can communicate through the gas leakage hole 157 regardless of whether the one-way valve 156 is open or not. The gas flow speed through the gas leakage hole 157 is much smaller than the gas flow speed through the one-way valve 156, for example, the gas flow speed through the gas leakage hole 157 is 1 / 5, 1 / 10, etc. of the gas flow speed through the one-way valve 156. The gas flow speed through the gas leakage hole 157 can be determined by the number and size of the gas leakage hole 157.

[0067] When the manual part 151 is pressed, the one-way valve 156 is opened, and the gas can flow from the first cavity 153 to the second cavity 154, and the first cavity 153 decreases and the second cavity 154 increases. The second reset spring 155 is compressed, the manual part 151 is retracted, and the second access door 122 can be closed. When the manual part 151 is released, the one-way valve 156 is closed, the second reset spring 155 pushes the sliding piece 152 to move outward, and the gas can only flow from the second cavity 154 to the first cavity 153 through the gas leakage hole 157. The gas can flow from the second cavity 154 to the first cavity 153 through the gas leakage hole 157, and the manual part 151 extends.

[0068] It should be noted that the size and proportion in the drawings can be adjusted according to actual needs, and the drawings only represent the cooperation relationship between them.

[0069] Furthermore, if the second access door 122 is automatically closed, the seal between the second access door 122 and the inner housing 121 may be poor. To ensure the seal after automatic closure, this embodiment provides the following improvement: The second access door 122 includes a hinged end and a movable end. The hinged end is hinged to the inner housing 121, and the movable end is magnetically attracted to the corresponding part of the inner housing 121. That is, the movable end is provided with a magnet, and the corresponding part of the inner housing 121 is provided with a magnet or metal material, or the corresponding part of the inner housing 121 is provided with a magnet, and the movable end is provided with a magnet or metal material, so that the two can attract each other. In some embodiments, a locking structure can also be provided at the corresponding part of the movable end and the inner housing 121. After the second access door 122 is manually closed, the locking structure locks the second access door 122 and the inner housing 121.

[0070] by Figure 1 , Figure 3 For example, the inner casing 12 is provided with four second inspection doors 122, which are numbered from left to right as the first door, second door, third door, and fourth door, as shown in the figure. The first door opens to the left, while the second, third, and fourth doors open to the right. When manufacturing or installing unit 120, hinge parts need to be reserved at different locations, thus limiting the opening direction of the second inspection doors 122. Different units 120 may have different opening directions, which is time-consuming and labor-intensive. Furthermore, assuming that the third door and the fourth door are to be inspected simultaneously, the corresponding doors can only be opened one by one. For example, the third door must be opened first to inspect the functional units inside the third door, and then the third door must be closed and the fourth door opened to inspect the functional units inside the fourth door.

[0071] In this embodiment, the following improvement is provided: Please refer to Figure 6 As shown, the second inspection door 122 includes a door frame 123 and a third inspection door 124.

[0072] The style of the door frame 123 is not limited. For example, the door frame 123 can adopt a rectangular frame structure. The outer dimensions of the door frame 123 match the dimensions of the second access port, and the interior of the door frame 123 forms a third access port.

[0073] The third inspection door 124 is rotatably mounted on the door frame 123. In this embodiment, the third inspection door 124 is hinged to the door frame 123, and the rotation center line of the third inspection door 124 relative to the door frame 123 is vertically arranged. During the rotation of the third inspection door 124, the third inspection opening can be opened or closed. When the third inspection door 124 is open, the third inspection opening is exposed, and the staff can inspect the internal functional units. When the third inspection door 124 is closed, the third inspection opening is sealed, making the unit 120 form a relatively closed area for gas flow and preventing gas leakage or external impurities from entering the unit 120.

[0074] Briefly speaking, as long as any one of the second access opening and the third access opening is opened, the functional units inside can be maintained. For example, if the third door and the fourth door need to be maintained at the same time, the third door can be opened to the left and the fourth door can be opened to the right, so that the functional units inside the third door and the fourth door can be maintained at the same time. Of course, the functional units inside the second door and the fourth door can also be maintained at the same time, in which case the third door only needs to be closed.

[0075] The connection position between the second access door 122 and the inner shell 121 determines the opening direction of the second access door 122, and the opening direction of the second access door 122 is opposite to the opening direction of the third access door 124. For example, the second access door 122 can be opened to the left, and the third access door 124 can be opened to the right.

[0076] Specifically, the door frame 123 is provided with a first hinged end and a first movable end. The first hinged end is hinged to the inner shell 121, and the second access door 122 can rotate around the first hinged end to open or close the second access opening. A first locking unit 125 is arranged between the first movable end and the inner shell 121. The structure of the first locking unit 125 is not limited and can refer to the prior art, as long as it can fix and unlock the first movable end and the inner shell 121. For example, the first locking unit 125 can adopt a quick lock, a mechanical lock, etc.

[0077] The third access door 124 is provided with a second hinged end and a second movable end. The second hinged end is hinged to the door frame 123, and the third access door 124 can rotate around the second hinged end to open or close the third access opening. A second locking unit 126 is arranged between the second movable end and the door frame 123. The structure of the second locking unit 126 is not limited and can refer to the prior art, as long as it can fix and unlock the second movable end and the door frame 123. For example, the second locking unit 126 can adopt a quick lock, a mechanical lock, etc.

[0078] The first hinged end is adjacent to the second movable end, and the second hinged end is adjacent to the first movable end. The hinged manner of the door frame 123 and the inner shell 121, and the third access door 124 and the door frame 123 is not limited, for example, the two are hinged through a leaf or a pivot shaft.

[0079] Generally speaking, at the same time, the second access door 122 and the third access door 124 cannot be opened at the same time, that is, the second access door 122 and the third access door 124 are closed at the same time, or the second access door 122 is opened and the third access door 124 is closed, or the second access door 122 is closed and the third access door 124 is opened.

[0080] Of course, in some embodiments, the second access door 122 can also not be provided with the third access door 124.

[0081] Correspondingly, the reminding component 130 is also used for detecting the state of the third access door 124, and when the first access door 111 is closed and any one of the second access door 122 or the third access door 124 is not closed, the reminding component 130 alarms.

[0082] Specifically, the structure of the reminding component 130 is based on the previous scheme, and a plurality of third switches 134 are added in series with the power supply 131, the first switch 132 and any one of the second switch 133 or the third switch 134, and a plurality of second switches 133 and a plurality of third switches 134 are connected in parallel and each correspondingly provided with an alarm lamp 135.

[0083] The first switch 132 is matched with the first access door 111, and when the first access door 111 is closed, the first switch 132 is closed, and when the first access door 111 is opened, the first switch 132 is opened. The second switch 133 is matched with the second access door 122, and when the second access door 122 is closed, the second switch 133 is opened, and when the second access door 122 is opened, the second switch 133 is closed. The third switch 134 is matched with the third access door 124, and when the third access door 124 is closed, the third switch 134 is opened, and when the third access door 124 is opened, the third switch 134 is closed.

[0084] In addition, the second access door 122 is provided with a second door closing component 141, and the specific structure of the second door closing component 141 can be the same as or similar to that of the first door closing component 140, except that the installation position and the controlled access door are changed. The second door closing component 141 can be triggered by the third access door 124 which is opened by a preset angle threshold, and the third access door 124 which is opened is locked within a preset time threshold, and is unlocked when the preset time threshold is exceeded, so that the third access door 124 is automatically closed.

[0085] Correspondingly, a plurality of alarm lamps 135 are arranged on the outer shell 11 and divided into upper and lower two rows, the upper alarm lamps 135 are arranged in order according to the corresponding second access door 122, and the lower alarm lamps 135 are arranged in order according to the corresponding third access door 124. If the reminding component 130 alarms, if the upper alarm lamp 135 is lit, it means that the corresponding second access door 122 is not closed, and if the lower alarm lamp 135 is lit, it means that the corresponding third access door 124 is not closed. In this way, the staff can accurately and quickly know which access door is not closed according to the position of the alarm lamp 135.

[0086] The working method of the fresh air system shell 10 provided in the embodiment is as follows:

[0087] When the first access door 111 is opened, the worker can enter the inside of the outer shell 110, at this time, the first switch 132 is disconnected. Some second access doors 122 or third access doors 124 are selectively opened, taking the opening of a certain second access door 122 as an example, the first locking unit 125 is opened, and the second access door 122 is rotated and opened, and the second access opening is exposed, at this time, the second switch 133 is closed. When the second access door 122 is rotated to a certain angle, the second access door 122 abuts against the trigger rod 142, the trigger rod 142 is triggered and pushed, the first reset spring 143 is compressed, the trigger rod 142 presses the trigger switch SB and makes the trigger switch SB closed, the power supply of the closed circuit 144 is energized, the electromagnetic valve 147 works, and the telescopic cylinder 145 is elongated to form the second end 160. The second access door 122 is released and reset to a certain angle under the action of the reset member 146 until the second access door 122 abuts against the second end 160, the second access door 122 is locked by the telescopic cylinder 145 and cannot continue to reset, at this time, the second access door 122 is maintained at a certain angle, the trigger rod 142 is reset under the action of the first reset spring 143, and the trigger switch SB is automatically disconnected; the worker can overhaul the internal functional units. If the overhaul time is less than the timing duration of the first door closing assembly 140, the second access door 122 can be manually closed or automatically closed after the overhaul is completed; if the overhaul time is greater than the timing duration of the first door closing assembly 140, the worker needs to trigger the trigger rod 142 again in the middle.

[0088] After the overhaul is completed, if the second access door 122 needs to be manually closed, the manual part 151 is manually pressed, the sliding member 152 slides in the telescopic cavity, the one-way valve 156 is opened, the gas can flow from the first cavity 153 to the second cavity 154, the first cavity 153 decreases and the second cavity 154 increases, and the second reset spring 155 is compressed. The second access door 122 is reset under the action of the reset member 146, and in this process, the second reset spring 155 pushes the sliding member 152 to slide, so that the manual part 151 extends out, at this time, the one-way valve 156 is closed, the gas can only flow from the second cavity 154 to the first cavity 153 through the air leakage hole 157, the first cavity 153 increases and the second cavity 154 decreases, even if the manual part 151 extends out, it will not block the reset of the second access door 122, because the second access door 122 has passed the blocked position. After the second access opening is closed by the second access door 122, the corresponding parts of the first movable end and the inner shell 121 are adsorbed by the magnetic adsorption effect to ensure the sealing between the second access door 122 and the second access opening. After the timing of the first door closing assembly 140 is completed, the electromagnetic valve 147 is de-energized, the telescopic cylinder 145 is automatically retracted and reset, and the next work is not affected.

[0089] After the maintenance is completed and the second access door 122 and the third access door 124 are all closed, the worker exits from the outer shell 110, and then closes the first access door 111, at this time, the first switch 132 is closed, if there is a part of the second access door 122 or the third access door 124 that is not closed, the corresponding line is powered on, and the corresponding alarm lamp 135 is lit, the worker can determine which second access door 122 or third access door 124 is not closed according to the position of the alarm lamp 135, needs to re-open the first access door 111 to enter the outer shell 110, and close the corresponding second access door 122 or third access door 124. If the worker does not notice the alarm lamp 135 information, then the first door closing assembly 140 or the second door closing assembly 141 is completed in a timely manner, the electromagnetic valve 147 is powered off, the telescopic cylinder 145 is automatically retracted to reset, and no longer blocks the second access door 122 or the third access door 124, and the second access door 122 or the third access door 124 is reset under the action of the reset member 146.

[0090] After the second access door 122 closes the second access opening or the third access door 124 closes the third access opening, the corresponding parts of the first movable end and the inner shell 121, or the corresponding parts of the second movable end and the door frame 123 are adsorbed by the magnetic adsorption effect to ensure the sealing between the second access door 122 and the second access opening.

[0091] The above steps can be increased, modified, adjusted in order, etc. according to the specific structure of the fresh air system shell 10.

[0092] The above only describes the preferred embodiments of the present application and is not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A fresh air system housing, characterized in that, The device includes an outer casing, an inner casing, and a closing mechanism. The inner casing is disposed inside the outer casing, and the outer casing has a first inspection door. The inner casing is composed of at least three individual units, each of which has a second inspection door rotatably mounted on it. The closing mechanism includes an alert component and a first closing component. The alert component detects the status of the first and second inspection doors. When the first inspection door is closed and any one of the second inspection doors is not closed, the alert component triggers an alarm. The first closing component is mounted on each individual unit and can be triggered by the second inspection door when it is opened to a preset angle threshold. It locks the opened second inspection door within a preset time threshold and unlocks it when the preset time threshold is exceeded, so that the second inspection door automatically closes. The second inspection door is rotatably equipped with a third inspection door and a second closing assembly. The rotation center lines of the second and third inspection doors extend vertically, and their opening directions are opposite. The reminder assembly includes a power supply, a first switch, several second switches, and several alarm lights. The power supply, the first switch, and any one of the second switches are connected in series, and the several second switches are connected in parallel and correspondingly equipped with the alarm lights. The first switch is matched with the first inspection door. When the first inspection door is closed, the first switch is closed; when the first inspection door is opened, the first switch is open. The second switch is matched with the second inspection door. When the second inspection door is closed, the second switch is open, and when the second inspection door is open, the second switch is closed. A reset element is provided at one end of the second inspection door, which gives the second inspection door a tendency to close. The first closing assembly includes a trigger rod, a first reset spring, a closing circuit, and a telescopic cylinder. The trigger rod is rotatably mounted on the unit and can be reset under the action of the first reset spring. When the second inspection door is opened to a preset angle threshold, it can push the trigger rod and close the closing circuit, so that the telescopic cylinder can extend and retract at regular intervals and lock or unlock the second inspection door. The telescopic cylinder includes a telescopic part and a manual part. The telescopic part is provided with a telescopic cavity. One end of the manual part is provided with a sliding member, which is slidably mounted in the telescopic cavity. The telescopic cavity is divided into a first cavity and a second cavity by the sliding member. A second reset spring is provided in the first cavity. A one-way valve is provided on the sliding member to allow airflow from the first cavity to the second cavity. The one-way valve is provided with a leakage hole. The airflow velocity through the leakage hole is much smaller than the airflow velocity through the one-way valve. The second reset spring gives the sliding member a tendency to move outward.

2. The fresh air system housing of claim 1, wherein, The reminder component is also used to detect the status of the third maintenance door. When the first maintenance door is closed and either the second maintenance door or the third maintenance door is not closed, the reminder component will sound an alarm. The second access door is provided with a second door closing assembly, the second door closing assembly can be triggered by the third access door opened by a preset angle threshold, the third access door opened within a preset time threshold is locked, and is unlocked when the preset time threshold is exceeded, so that the third access door is automatically closed.

3. The fresh air system housing of claim 2, wherein, The reminding assembly comprises a power supply, a first switch, a plurality of second switches, a plurality of third switches and a plurality of alarm lamps; the power supply, the first switch and any one of the second switch or the third switch are connected in series, the plurality of second switches and the plurality of third switches are connected in parallel and each correspondingly provided with the alarm lamp; the first switch is matched with the first access door, the first switch is closed when the first access door is closed, and the first switch is opened when the first access door is opened; The second switch is matched with the second access door, the second switch is opened when the second access door is closed, and the second switch is closed when the second access door is opened; The third switch is matched with the third access door, the third switch is opened when the third access door is closed, and the third switch is closed when the third access door is opened.

4. The fresh air system housing of claim 3, wherein, The plurality of alarm lamps are arranged on the outer shell and divided into upper and lower rows, the upper alarm lamps are arranged in the order of the corresponding second access doors, and the lower alarm lamps are arranged in the order of the corresponding third access doors.

5. The fresh air system housing of claim 1, wherein, The closing circuit comprises a trigger switch and an electromagnetic valve, the electromagnetic valve is a single-electronic-control two-position five-way electromagnetic valve, the trigger rod can make the trigger switch closed and the trigger switch can be reset to be opened, and the telescopic cylinder is controlled by the electromagnetic valve; when the closing circuit is powered on, the telescopic cylinder can be elongated and abut against the inner side of the second access door; after the closing circuit is powered off for a preset time threshold, the telescopic cylinder is retracted and the reset member can push the second access door to be closed.

6. The fresh air system housing of claim 1, wherein, A buffer interval is arranged between the trigger rod and the telescopic cylinder, the buffer interval has a first end and a second end; when the second access door reaches the first end, the trigger rod can be triggered, the telescopic cylinder is extended and the second end is formed; when the second access door is located at the second end, the trigger rod can be reset and the closing circuit starts timing.

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