CN116428259A - Blocking protection device for mechanical structure and installation method - Google Patents

Abstract

The invention discloses a protection device for blockage of a mechanical structure, which comprises a protection structure; the protection structure comprises a main body and a latch; the main body comprises a boss, a cylindrical section, and a threaded body; One end of the platform is provided with a threaded body, and the cylindrical section is provided with an accommodating hole through the boss, and the cylindrical section is provided with a connecting threaded hole passing through the threaded body, the accommodating hole is connected with the connecting threaded hole, and the diameter of the accommodating hole is larger than Connecting the diameter of the threaded hole, the cylindrical section is provided with a slot for accommodating the bolt; it also includes a mechanical body provided with a threaded hole of the body, the threaded hole of the body is stepped downward, and the cylindrical section and the threaded body are sequentially matched with the threaded hole of the body. The blocking protection device for the mechanical structure proposed by the present invention can prevent the threaded hole of the body from being damaged and prolong the service life by isolating the threaded hole of the body from external devices or blockage through the protection structure.

Description

Protection device and installation method for blockage of mechanical structure

technical field

The invention belongs to the field of mechanical structures, and in particular relates to a protection device and an installation method for blocking a mechanical structure.

Background technique

As shown in FIG. 1 , the existing mechanical structure generally has threaded holes directly on the machine body. During daily use of the machine structure, the threaded holes are used to check the inside of the machine body, or to fill/discharge liquids, etc. As shown in Figure 2, during the daily use of the mechanical structure, plugs are used to screw into the threaded holes on the body, so that a closed space is formed inside and outside the body, thereby preventing liquid leakage or sand and dust from entering the body. When it is necessary to check the inside of the body, or add/discharge liquid, unscrew the blockage to form an open space inside and outside the body, and then check the inside of the body through the threaded hole, or add/discharge liquid, etc. This structure is relatively simple and relatively easy to use. convenient.

As shown in Figure 3, the material of the general body is relatively soft. When inspecting the inside of the body, or filling/discharging liquid, the inspection device or the filling device/discharging device will inevitably touch the threaded hole of the body, which will inevitably damage the threaded hole, resulting in When screwing in/out the plug, the thread of the plug will be damaged, which will cause the plug to fail to completely block the threaded hole on the body, resulting in the leakage of liquid in the body or the entry of sand and dust into the body. And damage to the threaded hole will cause the number of times the threaded hole on the body to be used to decrease, and because the threaded hole cannot be replaced, it will eventually cause the service life of the body to decrease, thereby resulting in greater maintenance costs.

Therefore, the purpose of the present invention is to provide a protective structure that can not only protect the threaded hole of the machine body from damage, but also make the plugging use safer and more reliable.

Contents of the invention

In view of the above problems, the present invention discloses a protective device for blockage of a mechanical structure, including a protective structure;

The protective structure includes a main body and a latch; the main body includes a boss, a cylindrical section, and a threaded body. The outer diameter of the boss is provided with a cylindrical section, and the end of the cylindrical section away from the boss is provided with a threaded body. The cylindrical section is provided with an accommodating hole through the boss, the cylindrical section is provided with a connecting threaded hole passing through the threaded body, the accommodating hole communicates with the connecting threaded hole, and the diameter of the accommodating hole is larger than that of the connecting thread the diameter of the hole, the cylindrical section is provided with a slot for accommodating the bolt;

It also includes a mechanical body provided with threaded holes in the machine body. The threaded holes in the machine body are stepped downwards, and the cylindrical section and the threaded body are sequentially matched with the threaded holes in the machine body.

Furthermore, the bolt includes a force application section, a holding section, and a guide section, and the end of the force application section is provided with a holding section and a guide section in sequence;

A V-shaped groove is provided on the force applying section;

The width of the force applying section is smaller than the width of the slot;

The width of the retaining section is greater than the width of the slot;

The width of the guide segment is smaller than the width of the slot.

Furthermore, the diameter of the threaded body is smaller than the diameter AC of the cylindrical section, and the diameter of the cylindrical groove is smaller than the diameter of the threaded body.

Furthermore, the circular surface a of the boss is higher than the circular surface b of the cylinder segment.

Furthermore, the outer diameter AB of the boss is larger than the inner diameter AA of the accommodating hole, and the outer diameter AB of the boss is smaller than the outer diameter AC of the cylindrical section.

Furthermore, the threaded hole of the machine body includes a counterbore and a threaded section arranged downward in steps, and the cylindrical section and the threaded body are sequentially matched with the counterbore and the threaded section in steps.

Furthermore, the counterbore includes a first counterbore and a second counterbore arranged downward in steps, the diameters of the first counterbore, the second counterbore and the threaded section become smaller gradually, and the diameter of the cylindrical section accommodates placed in the first counterbore.

Furthermore, a cylindrical groove is provided on the part of the threaded body close to the cylindrical section, and a sealing ring is arranged in the cylindrical groove, and the section height of the sealing ring is smaller than the height of the second counterbore.

Furthermore, the circular surface b of the cylindrical section is lower than the end surface c of the threaded hole of the machine body, and the end surface d of the pin is lower than the circular surface b of the cylindrical section.

Another object of the present invention is to disclose a method for installing a blocking protection device for a mechanical structure, comprising the following steps:

Fit and press the guide section of the pin into the slot of the main body, apply force to the force application section, so that the side walls of the holding section and the side walls of the slot are squeezed, and then connect the main body in the threaded hole of the body, and continue Apply force to the force-applying section, so that the remaining part of the holding section completely enters the slot and squeezes against the two side walls of the slot, and the force-applying section squeezes against the wall of the first counterbore until the end surface d of the pin is lower than the cylindrical section End face b, complete the installation of the protection device, and then screw the plug into the main body.

Compared with prior art, the beneficial effect of the present invention is:

1) The present invention is not only easy to achieve sealing, convenient to assemble and disassemble, but also makes the use of plugging safer and more reliable.

2) The invention reduces the maintenance cost, and has simple processing and low production cost.

3) Compared with the existing threaded hole of the body and the blocking fit, the present invention can protect the threaded hole of the body from damage by isolating the inspection device, filling device, and discharge device through the protective structure when checking the inside of the body, or filling or discharging liquid, The reliability is better and the service life of the machine body is extended.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure pointed out in the written description, claims hereof as well as the appended drawings.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description These are some embodiments of the present invention. Those skilled in the art can also obtain other drawings based on these drawings without creative work.

Fig. 1 shows the structural representation of existing mechanical structure threaded hole;

Fig. 2 shows the structural representation of existing blockage;

Fig. 3 shows the connection schematic diagram of screwing the existing plug into the threaded hole of the existing mechanical structure;

FIG. 4 shows a schematic structural diagram according to Embodiment 1 of the present invention;

Figure 5 shows a perspective view of Figure 4 with the sealing ring removed;

Figure 6 shows a schematic structural view of the main body;

Fig. 7 shows the top view of Fig. 6;

Figure 8 shows a cross-sectional view of A-A in Figure 7;

FIG. 9 shows a schematic structural diagram of a plug according to Embodiment 1 of the present invention;

Fig. 10 shows a perspective view of a plug according to Embodiment 1 of the present invention;

Fig. 11 shows a schematic structural diagram of a sealing ring according to Embodiment 1 of the present invention;

Fig. 12 shows a schematic structural view of the threaded hole of the machine body according to Embodiment 1 of the present invention;

Fig. 13 shows a perspective view of the threaded hole of the machine body according to Embodiment 1 of the present invention;

Fig. 14 shows a schematic diagram of a protective structure installed in a mechanical threaded hole according to Embodiment 1 of the present invention;

Fig. 15 shows a schematic diagram of the protection structure according to Embodiment 1 of the present invention after being installed in a mechanical threaded hole;

Figure 16 shows a schematic view of the plug being screwed into the protective structure;

Figure 17 shows a schematic diagram of the state after the plug is inserted into the slot;

Reference signs: 1 main body, 11 boss, 111 accommodating hole, 112 circular surface a, 12 connecting threaded hole, 13 cylindrical section, 131 slot, 132 circular surface b, 14 threaded body, 141 cylindrical groove, 15 sealing ring , 16 pin, 161 end face d, 162 force applying section, 1621 V-shaped groove, 163 holding section, 164 guiding section, 2 machine body, 21 body threaded hole, 22 end face c, 23 first counterbore, 24 second counterbore, 25 threaded segments.

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments It is a part of embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

FIG. 4 shows a schematic structural diagram according to Embodiment 1 of the present invention. As shown in Figure 4, a protective device for plugging a mechanical structure, including a protective structure;

The protective structure includes a main body 1 and a latch 16; the main body 1 includes a boss 11, a cylindrical section 13, and a threaded body 14, the outer diameter of the boss 11 is provided with a cylindrical section 13, and the end of the cylindrical section 13 away from the boss 11 is provided with a threaded body 14 , the cylindrical section 13 is provided with a receiving hole 111 through the boss 11, the cylindrical section 13 is provided with a connecting threaded hole 12 passing through the threaded body 14, the receiving hole 111 communicates with the connecting threaded hole 12, and the receiving hole 111 The diameter is greater than the diameter of the connecting threaded hole 12, and the cylindrical section 13 is provided with a slot 131 for accommodating the pin 16;

It also includes a mechanical body 2 provided with a threaded hole 21 of the body, the threaded hole 21 of the body is stepped downward, and the cylindrical section 13 and the threaded body 14 are sequentially matched with the threaded hole 21 of the body.

FIG. 5 shows a perspective view of FIG. 4 with the sealing ring 15 removed. As shown in FIG. 5 , in some embodiments, at least one slot 131 is provided on the cylindrical section 13 , which is used to prevent the pin 16 from falling off from the protection structure when it is not fully pressed into the slot 131 .

In some embodiments, the boss 11, the cylindrical section 13, the threaded body 14, and the pin 16 are made of corrosion-resistant steel, which has high strength and good corrosion resistance, and prolongs the service life of the protective structure.

FIG. 11 shows a schematic structural diagram of a sealing ring 15 according to Embodiment 1 of the present invention. As shown in FIG. 11 , in some embodiments, the cylindrical groove 141 cooperates with the sealing ring 15 to realize the sealing connection between the protection structure and the threaded hole 21 of the machine body to prevent liquid leakage.

The blockage protection device for mechanical structure of the present invention can not only protect the threaded hole 21 of the machine body from damage and prolong its life, but also completely block the threaded hole 21 of the machine body, so that the inside and outside of the machine body 2 can be formed The space is safely closed to prevent liquid leakage or sand and dust from entering the interior of the mechanical body 2, and also makes the use of blockages safer and more reliable.

Fig. 10 shows a perspective view of the plug 16 according to Embodiment 1 of the present invention. As shown in FIG. 10 , in some embodiments, the bolt 16 includes a force applying section 162 , a holding section 163 , and a guiding section 164 , and the end of the force applying section 162 is provided with a holding section 163 and a guiding section 164 in sequence;

A V-shaped groove 1621 is provided on the force application section 162;

The width of the force application section 162 is smaller than the width of the slot 131;

The width of the holding section 163 is greater than the width of the slot 131;

The width of the guide section 164 is smaller than the width of the slot 131;

FIG. 9 shows a schematic structural diagram of the plug 16 according to Embodiment 1 of the present invention. As shown in FIG. 9 , the guide section 164 guides the pin 16 to fit and press into the slot 131 correctly, and the two side walls of the holding section 163 are pressed against the two side walls of the slot 131 , which is used when the pin 16 is not completely pressed into the slot 131 To prevent falling off from the protective structure, and the force application section 162 can facilitate construction tools to press it into the slot 131; FIG. 17 shows a schematic diagram of the state of the pin inserted into the slot. As shown in Figure 17, the V-shaped groove 1621 on the force application section 162 is not only conducive to reducing the weight of the bolt 16 itself, maintaining the rigidity of the bolt 16, but also forming a sharp edge on the bolt 16 to facilitate the pressing of the bolt 16, and Squeeze the wall surface of the threaded hole 21 of the body to prevent the protective structure from loosening after being loaded into the threaded hole 21 of the body.

FIG. 8 shows a cross-sectional view of AA in FIG. 7 . As shown in Figure 8, in some embodiments, the outer diameter of the threaded body 14 is smaller than the outer diameter AC of the cylindrical section 13, and the outer diameter of the cylindrical groove 141 is smaller than the outer diameter of the threaded body 14, which is convenient for assembling the sealing ring 15, and is used for the protection structure and the threaded hole of the body 21 The sealing connection provides a sealing condition to prevent the liquid inside the mechanical body 2 from leaking.

FIG. 6 shows a schematic structural view of the main body 11 . As shown in Figure 6, in some embodiments, the circular surface a112 of the boss 11 is higher than the circular surface b132 of the cylindrical section 13, the circular surface a112 of the boss 11 is in contact with the lower part of the plugging head, and the circular surface a112 of the boss 11 is in contact with the circular surface of the cylindrical section 13. The surface b132 is relatively independent, so as to prevent the plugged contact surface from being damaged when the plug 16 is pressed in, thereby resulting in loose plugging and leakage.

FIG. 7 shows a top view of FIG. 6 . As shown in Figure 7, in some embodiments, the outer diameter AB of the boss 11 is larger than the inner diameter AA of the accommodating hole 111, the outer diameter AB of the boss 11 is smaller than the outer diameter AC of the cylindrical section 13, and the outer diameter AC of the cylindrical section 13 is the same as that of the boss 11. A slot 131 for accommodating the pin 16 can be provided at a position between the outer diameters AB, and the accommodating hole 111 is used for contacting and connecting with the blocked sealing strip, thereby isolating the plug from the slot 131 to avoid pressing the plug 16, The plug 16 is damaged and blocked to cause leakage or sand and dust to enter the inside of the mechanical body 2, making the blocked use safer and more reliable.

Fig. 13 shows a perspective view of the threaded hole 21 of the machine body according to Embodiment 1 of the present invention. As shown in Figure 13, in some embodiments, the threaded hole 21 of the body includes a counterbore and a threaded section 25 arranged downward in steps, and the cylindrical section 13 and the threaded body 14 are sequentially matched with the counterbore and the threaded section 25 in steps; the threaded body 14 is threadedly connected with the threaded section 25, which ensures the connection between the main body 1 and the threaded hole 21 of the machine body. The cylindrical section 13 is accommodated in the counterbore, which can provide positional conditions for the pin 16 to squeeze the wall of the counterbore.

FIG. 12 shows a schematic structural view of the body threaded hole 21 according to Embodiment 1 of the present invention. As shown in FIG. 12 , in some embodiments, the counterbore includes a first counterbore 23 and a second counterbore 24 arranged downward in steps, the diameters of the first counterbore 23 , the second counterbore 24 , and the threaded section 25 gradually becomes smaller, the cylindrical section 13 is accommodated in the first counterbore 23; the sealing ring 15 is in contact with the wall of the second counterbore 24, and the sealing ring 15 can realize the sealing of the protective structure and the threaded hole 21 of the body, while the latch 16 After the cylindrical section 13 is inserted, it can be interference fit with the first counterbore 23 and prevent loosening after the protective structure is installed into the threaded hole 21 of the machine body.

In some embodiments, the diameter DA of the first counterbore 23 is greater than the diameter DB of the second counterbore 24, and the diameter DB of the second counterbore 24 is greater than the diameter DC of the threaded section 25, which is convenient for matching the cylindrical section 13, the sealing ring 15, and the threaded body 14, The protective structure is loaded into the threaded hole 21 of the body.

Fig. 15 shows a schematic view of the protection structure according to Embodiment 1 of the present invention after being installed in a mechanical threaded hole. As shown in FIG. 15 , in some embodiments, the circular surface b132 of the cylindrical section 13 is lower than the end surface c22 of the threaded hole 21 of the machine body, and the end surface d161 of the pin 16 is lower than the circular surface b132 of the cylindrical section 13 to realize reliable installation of the protective structure.

Fig. 14 shows a schematic view of the protection structure according to Embodiment 1 of the present invention being installed into a mechanically threaded hole. As shown in FIG. 14 , in some embodiments, the circular surface b132 of the cylindrical section 13 is lower than the end surface c22 of the threaded hole 21 of the machine body, which can ensure the complete connection between the threaded body 14 and the threaded section 25 .

Figure 16 shows a schematic view of an existing plug screwed into a protective structure. As shown in Figure 16, in some embodiments, the end face d161 of the pin 16 is lower than the circular surface b132 of the cylindrical section 13, so as to ensure that the pin 16 and the first counterbore 23 are extruded, causing the counterbore to undergo plastic deformation at the extruded position, preventing The protection structure rotates to prevent the protection device from loosening, and the reliability is higher.

The working principle of the blocking protection device for mechanical structure is as follows:

Fit and press the guide section 164 of the bolt 16 into the slot 131 of the main body 1, apply force to the force application section 162, so that the two side walls of the holding section 163 and the two side walls of the bolt 16 are squeezed, and then the thread of the main body 1 The body 14 is screwed into the threaded section 25. After the connection is in place, the sealing ring 15 is in close contact with the wall of the second counterbore 24. The circular surface b132 of the cylindrical section 13 is lower than the end surface c22 of the threaded hole 21 of the body, and then the force applied by the bolt 16 Continuously apply tools on the section 162 to press the bolt 16 along the slot 131. During the pressing process, the remaining part of the holding section 163 is pressed against the groove wall of the slot 131 to generate extrusion force, so as to limit the bolt 16 and prevent the bolt. 16 falls off, and the V-shaped groove 1621 on the force application section 162 can form a sharp sawtooth edge on the bolt 16, squeeze the wall surface of the first counterbore 23, make the first counterbore 23 plastically deform, prevent the main body 1 from rotating, press in The end face d161 of the last bolt 16 is lower than the circular surface b132 of the cylindrical section 13. At this time, the sharp sawtooth edge of the bolt 16 forms an interference fit with the first counterbore 23, which realizes the installation of the protective structure. After the installation is completed, the plug and the connecting thread The hole 12 is connected, and the sealing strip on the plug is in close contact with the accommodating hole 111, so that a closed space is formed inside and outside the mechanical body 2. The protection structure plays the role of isolating the inspection device, the filling device, the discharge device and protecting the threaded hole 21 of the body, prolonging the service life of the threaded hole 21 of the body.

During daily use, there is no need to check the interior, or when filling/discharging liquid, the mechanical body 2 can be closed by screwing in the plug in the protective structure. Unscrew the plug at the structure to realize the opening of the body. Because the protective structure plays an isolation role, the inspection device or filling/discharging device will not damage the threaded hole 21 of the body, prolonging the service life of the threaded hole 21 of the body.

If the protective structure is damaged and needs to be disassembled, it is only necessary to use a tool to remove the position of the cylindrical section 13 close to the slot 131, and then use the tool to pull out the latch 16, and then screw out the protective structure along the screw thread, which is convenient and convenient for disassembly. The machine body 2 is not damaged.

Specifically, the sealing strip on the blockage is in close contact with the accommodating hole 111 , which can prevent liquid from leaking from the blockage position or prevent other liquids from entering the mechanical body 2 from the blockage position.

A method of installing a blocking protection device for a mechanical structure:

Fit and press the guide section 164 of the pin 16 into the slot 131 of the main body 1, apply force to the force applying section 162, so that the two side walls of the holding section 163 and the two side walls of the slot 131 are squeezed, and then the main body 1 is connected. In the threaded hole 21 of the body, and constantly apply force to the force applying section 162, so that the remaining part of the holding section 163 enters the slot 131 completely and squeezes with the two side walls of the slot 131, and the force applying section 162 and the first sink The wall surface of the hole 23 is squeezed until the end face d161 of the bolt 16 is lower than the end face b of the cylindrical section 13, and the installation of the protection device is completed, and then the plug is screwed into the main body 1.

Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that: they can still modify the technical solutions described in the aforementioned embodiments, or perform equivalent replacements for some of the technical features; and these The modification or replacement does not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims (10)

1. A protective device for plugging a mechanical structure, characterized in that it comprises a protective structure; The protective structure includes a main body (1), a latch (16); the main body (1) includes a boss (11), a cylindrical section (13), a threaded body (14), and the outer diameter of the boss (11) A cylindrical section (13) is provided, and the end of the cylindrical section (13) away from the boss (11) is provided with a threaded body (14), and the cylindrical section (13) is provided with a housing through the boss (11). hole (111), the cylindrical section (13) is provided with a connecting threaded hole (12) through the threaded body (14), the accommodating hole (111) communicates with the connecting threaded hole (12), and the accommodating The diameter of the hole (111) is greater than the diameter of the connecting threaded hole (12), and the cylindrical section (13) is provided with a slot (131) for accommodating the pin (16); It also includes a mechanical body (2) provided with a threaded hole (21) of the body, the threaded hole (21) of the body is downward in steps, and the cylindrical section (13) and the threaded body (14) are sequentially connected with the threaded hole (21) of the body ladder fit. 2. A blocking protection device for a mechanical structure according to claim 1, characterized in that, the pin (16) comprises a force applying section (162), a holding section (163), and a guiding section (164), the The end of the force application section (162) is provided with a holding section (163) and a guiding section (164) in sequence; A V-shaped groove (1621) is provided on the force application section (162); The width of the force applying section (162) is smaller than the width of the slot (131); The width of the retaining section (163) is greater than the width of the slot (131); The width of the guide segment (164) is smaller than the width of the slot (131). 3. The protection device for blockage of a mechanical structure according to claim 1, characterized in that, the diameter of the threaded body (14) is smaller than the diameter AC of the cylindrical section (13), and the diameter of the cylindrical groove (141) is smaller than the diameter of the screw thread Body (14) diameter. 4 . The protection device for blocking a mechanical structure according to claim 1 , characterized in that, the circular surface a ( 112 ) of the boss ( 11 ) is higher than the circular surface b ( 132 ) of the cylindrical section ( 13 ). 5. A protection device for mechanical structure blockage according to claim 1, characterized in that, the outer diameter AB of the boss (11) is greater than the inner diameter AA of the accommodating hole (111), and the boss (11) The outer diameter AB is smaller than the outer diameter AC of the cylindrical section (13). 6. The protection device for blocking a mechanical structure according to claim 1, characterized in that, the threaded hole (21) of the machine body includes a counterbore and a threaded section (25) arranged downward in steps, and the cylindrical Section (13), threaded body (14) cooperate with counterbore, threaded section (25) steps successively. 7. The protective device for blocking a mechanical structure according to claim 6, characterized in that, the counterbore comprises a first counterbore (23) and a second counterbore (24) arranged downward in steps, The diameters of the first counterbore (23), the second counterbore (24) and the threaded section (25) gradually decrease, and the cylindrical section (13) is accommodated in the first counterbore (23). 8. A blocking protection device for a mechanical structure according to claim 7, characterized in that, a cylindrical groove (141) is provided on the threaded body (14) near the cylindrical section (13), and the cylindrical groove (141) is provided with a sealing ring (15), and the section height of the sealing ring (15) is smaller than the height of the second counterbore (24). 9. The protection device for blocking a mechanical structure according to claim 1, characterized in that, the circular surface b (132) of the cylindrical section (13) is lower than the end surface c (22) of the threaded hole (21) of the machine body, The end surface d (161) of the pin (16) is lower than the circular surface b (132) of the cylindrical section (13). 10. A method for installing a blocking protection device for a mechanical structure according to any one of claims 1 to 9, characterized in that it includes the following steps: Fit and press the guide section (164) of the latch (16) into the slot (131) of the main body (1), apply force to the force application section (162), so that the two side walls of the holding section (163) are in contact with the slot ( 131) The walls on both sides are squeezed, and then the main body (1) is connected in the threaded hole (21) of the machine body, and force is continuously applied to the force applying section (162), so that the remaining part of the holding section (163) completely enters the insertion The groove (131) is squeezed with the two side walls of the slot (131), and the force section (162) is squeezed with the wall of the first counterbore (23) until the end surface d (161) of the pin (16) is lower than the cylinder Section (13) end face b, complete the installation of the protective device, then screw in the plug in the main body (1).

Images