Power socket for detachably connecting to power plug and power connector consisting of such power socket and corresponding power plug

Abstract

The invention relates to a power socket (1) for detachable connection to a power plug (30), having a base body (2) made of an electrically conductive material and a device (4) for connection to a power line (40), the invention relates to a power socket (1) comprising a base body (2) having a bore (2 ') for receiving a substantially cylindrical pin (31) of a power plug (30), in which base body (2) a spiral groove (5) for the insertion of a locking nose (32) of the power plug (30) is arranged, the base body (2) of the power socket (1) comprising a sleeve (3) having the spiral groove (5) and a receptacle (3') for the sleeve (3), the invention also relates to a power connector (50) having such a power outlet (1) and a corresponding power plug (30). According to the invention, the helical groove (5) comprises at least two regions (a, c) having a positive gradient and a region (b, d) having a negative gradient is arranged at the end of each region (a, c) having a positive gradient to form a respective locking step, the receptacle (3 ') is formed from a metal or a metal alloy, the receptacle (3') having a sheath (13) of electrically insulating material, and the sleeve (3) is formed from a material that is harder than the receptacle (3 ').

Description

Technical Field

[0001] The invention relates to a power socket for detachably connecting to a power plug, the power socket having a base body made of conductive material and a device for connecting a power cord, the base body having a hole for accommodating a substantially cylindrical pin of the power plug, wherein a spiral groove for receiving a locking nose of the power plug is arranged in the base body, wherein the base body comprises a sleeve having a spiral groove and a receiving portion for the sleeve.

[0002] In addition, the present invention also relates to a power connector comprising the power socket and a corresponding power plug. Background Art

[0003] The term "substantially cylindrical" is intended to clarify that the hole in the base body of the mains socket and the pin of the matching mains plug may also deviate slightly from a rotationally symmetrical shape and, for example, be slightly non-circular.

[0004] Such a power socket, together with a suitable power plug, forms a power connector designed to transmit high currents of up to several hundred amperes. For example, this power connector is used in welding systems to conduct high welding currents from a welding power source to the welding torch and the workpiece. There is a standard DIN EN 60974-12 "Plug connections for welding cables" for these connections that are common in welding technology. However, this power socket can also be used for other applications, such as photovoltaic systems or battery chargers, as part of a corresponding power connector for transmitting direct current for solar modules or charging current for charging batteries.

[0005] In welding systems, plugs from DINSE Ges.mbH are often used as connectors for power cords and hose assembly connectors. These are known to technicians in the field of welding technology as plug, Socket or Connector. Use Connectors, a plug with a locking nose is screwed into a socket with a spiral groove with a rotation angle of about 270° and a gradient of about 4 mm per 360°. The thread-like interaction between the plug and the socket results in a certain preload force or a connected tightening torque, or a corresponding axial force, which keeps the plug connection in its connected state. Depending on the current, the plug and the socket have different cross-sections.

[0006] In shielded gas and plasma welding systems, the shielding gas or the medium capable of generating plasma is also supplied through a corresponding channel in the center of the power connector.

[0007] The relatively high gradient of the spiral groove in the power socket of the prior art together with the short preload length of the connection (the length of the plug connection extending from the current contact surface between the power plug and the power socket to the locking nose of the power plug) and the high preload surface (the surface of the power socket or the pin section of the power plug that loads the force) leads to an extremely steep preload characteristic, i.e. a high gradient of the force-displacement curve of the plug connection. This leads to very low energies required to release the connection (i.e. to separate the plug from the socket), and even temperature fluctuations or vibrations can lead to situations where the connection is unintentionally released. As soon as the connection loses its preload force, the contact resistance of the power connector increases rapidly. If high currents are transmitted, this can lead to local overheating of the connection between the power socket and the power plug and to oxidation of parts of the power cord and the power connector. The oxidized power connector in turn increases the operating temperature, which can lead to damage to the plastic parts of the power plug and the power socket, the connected power cord and the connected device (e.g. welding power supply). If the specified temperature values ​​are significantly exceeded, injuries to the operating personnel cannot be excluded. In addition, the increase in the contact resistance of the power connector can also have a negative impact on the corresponding process (e.g. welding process) and can even lead to defective production.

[0008] Power sockets have been further developed to improve the contact resistance of power connectors by significantly increasing the release energy or release torque of the connection by means of a spring-loaded locking nose of the plug. For example, such a power connector is described in WO 2016 / 128557A1, wherein a power plug of the power connector comprises a replaceably mounted locking pin, which is held in a default position by a spring device. In addition to the higher construction effort and the resulting higher manufacturing costs, a disadvantage of such a plug is that the construction in the center of the power plug means that a hole or cavity in the axial direction for guiding the gas cannot be realized or is not easily realized. Finally, the complexity of the solution is also disadvantageous in the power plug, which is usually exposed to more severe environmental conditions than the socket and is also located in a more price-sensitive part of the power connector.

[0009] DE 10 2018 007 686 A1 describes a welding power cord for connection to a welding power source, whereby the risk of unintentional separation of the power plug from the power socket due to tension is reduced by a bayonet element with a bayonet locking mechanism.

[0010] FR 2 270 695 A1 discloses an electrical socket of the aforementioned type, wherein a base body comprises a sleeve having a spiral groove and a receiving portion for the sleeve. Summary of the invention

[0011] The object of the invention is to produce a power socket as described above for a connector for transmitting high currents of up to several hundred A, such as can occur, for example, in welding systems, photovoltaic systems or battery chargers, which ensures the lowest possible contact resistance and thus enables optimal current transmission and prevents or at least minimizes the risk of local overheating of the power socket and the power plug due to inadmissibly high current densities. The power socket should be as simple and cost-effective to produce as possible and also allow central guidance of shielding gases, etc. The disadvantages of the known power sockets should be avoided or reduced.

[0012] The object according to the invention is solved by a power socket as described above, wherein the spiral groove comprises at least two areas with a positive gradient, and an area with a negative gradient arranged at the end of each area with a positive gradient to form a corresponding locking step, wherein the housing is formed of a metal or a metal alloy, the housing has a sheath of an electrically insulating material, and the sleeve is formed of a harder material than the housing. By dividing the base body into at least two parts, the sleeve with the spiral groove and the housing for the sleeve, the parts can be made of different materials and the other advantages described below can be achieved. By providing the spiral groove in the sleeve of the power socket with at least two areas with a positive gradient, and arranging an area with a negative gradient at the end of each area with a positive gradient, the operator can be given tactile feedback when the corresponding locking step is reached. In addition, this allows a release torque that is higher than the tightening torque to be achieved, which means that the power connector can no longer be released unintentionally very easily. By providing at least two locking steps, even an already worn power plug can be securely locked in the power socket by selecting the second or further locking step, i.e. after reaching the first locking step, the plug can be twisted even further relative to the power socket and then securely held in the next or following locking step. Due to the better connection of the power connector that is produced, the contact resistance can also be reduced and the risk of destruction or damage to the power socket, the power plug, the power cord or the device connected thereto, as well as the risk of injuries due to overheating and negative effects on corresponding processes (e.g. welding processes) can be reduced. The measures taken on the power socket allow connection to a conventional power plug, such as the above-mentioned Plug, and there is no need to replace the plug of conventional components (such as welding components). A further advantage of the power socket according to the invention is that the space around the central axis of the power socket can remain free of structural measures, whereby a hole or cavity can be easily arranged in the center of the power socket, for example for guiding shielding gas, a medium capable of generating plasma, a welding wire, etc. The fact that the technical features for solving the task according to the invention are arranged in the power socket means that the costs required for this can be transferred from the more cost-sensitive part of the power connector, the power plug, to the power socket. In addition, the power socket is usually located in the corresponding device, for example in the welding power supply, and is less exposed to harsh environmental conditions than the power plug. However, the necessary design measures on the power socket are also relatively simple and cost-effective to implement.

[0013] If a spring element is arranged in the receptacle of the sleeve of the base body for spring-mounted support of the sleeve in the axial direction of the receptacle of the base body, a further improvement of the connection between the power socket and the corresponding power plug and, therefore, a lower contact resistance of the power connector can be achieved. The spring force can further increase the release torque compared to the tightening torque of the plug connection and, therefore, further reduce the risk of unintentional separation of the power plug from the power socket. Thermal cycles, vibrations and shocks can no longer loosen the plug connection. By selecting the suitable spring element, the contact force of the power connection and, therefore, the contact resistance can be influenced. The spring element can be used to adjust the force effect on the contact surface in the corresponding locking step. The force action on the contact surface is preferably 5 to 50 N / mm 2 .

[0014] According to a feature of the invention, the spring element is formed by at least one wire spring washer, which can be produced very cost-effectively using corrugated flat wire and can be arranged in the power socket in a particularly space-saving manner, without requiring a central region of the socket, which can therefore be used for guiding protective gas or the like.

[0015] Advantageously, the spring element is formed by two wire spring washers and a spacer ring arranged between the wire spring washers. The spacer ring prevents the spring travel of the wire spring washers arranged on either side from being reduced by twisting the wire spring washers relative to each other, so that the full spring force of the wire spring washers can be utilized.

[0016] Ideally, the sleeve comprises a positioning element, in particular an axial locking nose, to prevent twisting of the receiving portion relative to the base body of the power socket. Such a positioning element on the sleeve is easy to implement and does not significantly increase the manufacturing costs.

[0017] The housing for the sleeve of the base body of the power socket may consist of two connectable parts. This means that the power socket can be assembled very quickly and easily and simply by placing the necessary components, the sleeve and any spring elements, at designated locations on the parts of the housing of the base body of the power socket and subsequently connecting the parts together. The two parts of the housing of the base body are preferably connected to each other by an interference fit. Alternatively, the parts of the housing of the base body may also be detachably connected to each other, for example by a threaded joint with a left-hand or right-hand thread.

[0018] In particular, the receptacle of the basic body can be produced from steel or a steel alloy or brass or a brass alloy.

[0019] The sleeve of the power socket is preferably made of steel or a steel alloy. This has the advantage that wear occurs more preferably on the softer power plug and not on the harder sleeve of the power socket.

[0020] The receiving part of the base body comprises a flat front face for the contact, in order to ensure an optimal current transmission to the power plug. Due to the flat design of the front face of the receiving part, a uniformly low contact resistance can be achieved over the entire contact surface. Thus, areas with a higher contact resistance on the contact surface, which could lead to local overheating due to particularly high current densities, are prevented. If protective gas or the like is supplied via the power socket, the area around the center axis is recessed and the front face is therefore preferably formed in a ring shape.

[0021] To improve current transmission, the front face of the receiving portion of the substrate may include a coating, for example a silver coating. Zinc or gold coatings are also possible for low contact resistance. Phosphate coatings, possibly in combination with other chemicals, protect the contact surface from corrosion.

[0022] According to a feature of the invention, the slot in the sleeve extends over a rotation angle of 90° to 270°, which is suitable for operating the power connector.

[0023] The gradient of the region of the groove with a positive gradient is ideally 1 mm to 8 mm per 360°. These values ​​are suitable for a suitable connection of the power socket with a suitable power plug with the locking nose. The gradient of the region of the spiral groove with a positive gradient does not necessarily have to be constant, but can also be gradual, i.e. for example increasing or decreasing.

[0024] The gradient of the area of ​​the groove with a negative gradient for forming the locking step is 0.1 mm to 20 mm, preferably 1 mm to 20 mm, more preferably 5 mm to 20 mm per 360°. By providing the area with a negative gradient, the release torque can be even further increased compared to the tightening torque and the tactile feedback to the user can be improved when reaching the locking step. As already mentioned above for the area with a positive gradient, the gradient of the area of ​​the spiral groove in the sleeve with a negative gradient can also be realized in a gradual manner.

[0025] According to other features of the present invention, the spiral groove may also include an area without gradient or without significant gradient after the area with negative gradient. By gradually changing between the area with negative gradient and the area without gradient, a smooth transition of these areas of the spiral groove can be achieved. This transition can have a positive impact on the user's tactile perception.

[0026] In the simplest case, the means for connecting to the power cord can be formed by a threaded joint. This constitutes a simple and cost-effective realization of the connection between the power cord and the power socket.

[0027] If the receiving part of the base body of the power socket comprises a continuous hole or the like in the axial direction for guiding a shielding gas or the like, a shielding gas or a medium capable of generating plasma can be guided through the power supply current contact. Instead of rotationally symmetrical holes, cavities of different shapes can also be provided in the axial direction of the receiving part of the base body for guiding a shielding gas or the like.

[0028] The object according to the invention is also solved by a power connector consisting of a power socket as described above and a corresponding power plug with substantially cylindrical pins. With regard to the advantages that can be achieved as a result, reference is made to the above description of the power socket.

[0029] If the sleeve of the power socket is made of a harder material than the cylindrical pin of the power plug, wear will preferably occur on the softer power plug and not on the harder sleeve of the power socket. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The invention is explained in more detail with reference to the accompanying drawings. They show:

[0031] Figure 1 A power connector consisting of a power socket and a power plug according to the prior art in a separated state;

[0032] Figure 2 A power plug and a power socket are connected to the Figure 1 A cross section of a prior art power connector;

[0033] Figure 3 An exploded view of a power socket according to the present invention;

[0034] Figures 4A to 4D A detailed view of a sleeve of an embodiment of a power socket according to the present invention;

[0035] Figure 5 A cross section of a power socket according to the invention;

[0036] Figure 6 Cross section of a power connector with a power plug that has not yet been locked into a power socket;

[0037] Figure 7 With a power plug that locks into a power socket Figure 6 A cross section of the power connector is shown;

[0038] Figure 8 A force-displacement preload diagram of a power connector having a power socket according to the present invention compared to a power connector having a conventional power socket; and

[0039] Fig. 9 The contact resistance and power loss of a power connector having a power socket according to the present invention are compared with a power connector having a conventional plug connection. DETAILED DESCRIPTION

[0040] exist Figure 1 In the figure, a power connector 50 consisting of a power socket 1 and a power plug 30 according to the prior art is shown in a separated state. In addition to a base body, corresponding insulation and means for connecting to a power cord 40, which are not described in detail, the power plug 30 comprises a substantially cylindrical pin 31 made of a conductive material, said pin 31 having a locking nose 32. The power socket 1 for detachable connection to the power plug 30 comprises a base body 2 made of a conductive material, said base body 2 having a hole 2' for accommodating the pin 31 of the power plug 30. The power socket 1 also comprises means 4 for connecting to the power cord 40, for example a threaded joint, which is not described in detail (see Figure 2). In the base body 2 of the power socket 1, there is a spiral groove 5 for the accommodation of the locking nose 32 of the power plug 30. In order to connect the power plug 30 to the power socket 1, the substantially cylindrical pin 31 of the power plug 30 is inserted into the hole 2' of the base body 2 of the power socket 1 in such a way that the locking lug 32 engages in the groove 5. The power plug 30 is then twisted relative to the power socket 1 according to the path (not shown) of the spiral groove 5 in the base body 2 of the power socket 1. However, the release torque is usually low and an unintentional separation of the power plug 30 from the power socket 1 of the power connector 50 may occur. In the event of temperature fluctuations or the presence of mechanical forces on parts of the power connector 50, the risk of loosening increases. The increase in contact resistance that occurs when the connection is loosened can lead to local overheating of the power plug 30, the power socket 1 and / or the power cord 40, as well as to damage to parts of these components. Although the situation can be improved by, for example, elastically mounted locking lugs 32, unintentional separation of the plug connection cannot be ruled out.

[0041] Figure 2 The diagram shows a power plug 30 and a power socket 1 connected to each other. Figure 1 1 is a cross-section of a prior art power connector 50. From this it can be seen how the locking nose 32 on the generally cylindrical pin 31 of the power plug 30 projects into the helical groove 5 in the base 2 of the power socket 1. Furthermore, it can be seen that the means 4 for connecting to the power cord 40 in the power socket 1 is in the form of a threaded fitting 16. The power socket 1 comprises a sheath 13 made of an electrically insulating material.

[0042] Figure 3An exploded view of an electrical socket 1 according to the invention is shown. The electrical socket 1 comprises a base body 2 made of an electrically conductive material, said base body 2 having a sleeve 3 and a housing 3' for the sleeve 3, said sleeve 3 having a spiral groove 5. In the embodiment shown, the housing 3' for the sleeve 3 comprises two connectable parts 11, 12. The parts 11, 12 of the housing 3' of the base body 2 are made, for example, of brass or a brass alloy and comprise a sheath 13 (not shown) made of an electrically insulating material. Preferably, the sleeve 3 is made of a harder material than the housing 3', for example steel or a steel alloy. The substantially cylindrical sleeve 3 is used for the insertion of a substantially cylindrical pin 31 (not shown) of a power plug 30. In order to prevent the sleeve 3 from twisting relative to the housing 3' of the base body 2, a positioning element 9 (in particular an axial locking nose 10) is arranged on the sleeve 3, said positioning element 9 (in particular an axial locking nose 10) protruding into a corresponding recess 18 in the part 11 of the housing 3' of the base body 2. The device 4 (e.g., threaded connector 16) for connecting to the power cord 40 is not shown in detail. According to the present invention, a spiral groove 5 is arranged in the sleeve 3 for accommodating the locking nose 32 of the power plug 30, wherein the spiral groove 5 comprises at least two regions a, c with positive gradients, and regions b, d with negative gradients are arranged at the end of each region a, c with positive gradients to form corresponding locking steps (see Figure 4A ).

[0043] Optionally, a spring element 6 can be arranged in the base body 2 for spring-mounted support of the sleeve 3 in the axial direction X of the housing 3 ′ of the base body 2, said spring element 6 being formed in the example shown by two wire spring washers 7 and two spacer rings 8. This can increase the holding force in the locked state and thus prevent or block an unintentional separation of the connection.

[0044] From Figure 4A A detailed view of the uncurled lateral surface of the sleeve 3 of the embodiment of the power socket 1 according to the invention is shown and Figures 4B to 4DThe three different views of the sleeve 3 shown can better understand the construction of the spiral groove 5. Therefore, the spiral groove 5 in the sleeve 3 includes at least two areas a, c with positive gradients, and the areas b, d with negative gradients are arranged at the ends of the areas a, c with positive gradients to form corresponding locking steps, and the area e without gradient or without significant gradient is also arranged at the ends of the areas a, c with positive gradients. Therefore, two locking steps are achieved by the sleeve 3 shown. By providing the spiral groove 5 in the sleeve 3 of the power socket 1, the power socket 1 has at least two areas a, c with positive gradients, and the areas b, d with negative gradients are arranged at the ends of each area a, c with positive gradients, when reaching the corresponding locking steps, the operator can be given tactile feedback. For a defined locking, there can be an area e without gradient or without significant gradient between the areas a, c with positive gradients and the areas b, d with negative gradients. However, these areas e without gradients or without significant gradients are not completely necessary. The regions a, c with positive gradients and the regions b, d with negative gradients may also be gradual, ie their gradients are not necessarily constant, and may, for example, increase or decrease.

[0045] Figure 5 Shown in assembled state Figure 3 A cross-section of an electrical socket 1 according to the invention is shown. Thus, the two parts 11, 12 of the receiving portion 3' of the base body 2 of the electrical socket 1 are connected to each other, for example by an interference fit. The sleeve 3 is arranged in the receiving portion 3' of the base body 2 and is replaceably mounted relative to the receiving portion 3' in the axial direction X by means of a spring element 6 in the form of two wire spring washers 7 and two spacer rings 8. This allows an increased force to be exerted on the front face 14 of the receiving portion 3' when the electrical socket 1 is connected to a power plug 30. A coating 15 of, for example, silver may be arranged on the front face 14 of the receiving portion 3' of the base body 2, said coating 15 further reducing the contact resistance And it can also prevent corrosion.

[0046] Figure 6 A cross section of the power connector 50 is shown, the power plug 30 not yet locked into the power socket 1. Therefore, the two wire spring washers 7 of the spring element 6 are relaxed. In the power plug 30, a continuous hole 17 for guiding protective gas or the like is arranged in the receiving portion 3 'of the base body 2, which hole 17 continues in the power socket 1 in the axial direction X.

[0047] Figure 7 It shows that Figure 6A cross section of a power connector 50 is shown, with the power plug 30 locked into the power socket 1. In this case, the wire spring washer 7 of the spring element 6 is compressed and the spring force is accordingly transmitted to the front face 14 of the receiving portion 3' of the base body 2 of the power socket 1. As a result, the contact resistance of the connection of the power connector 50 can be reduced.

[0048] Figure 8 The force-displacement preload diagram of a power connector 50 with a power socket 1 designed according to the invention having two locking steps (curve C) is shown in comparison with a power connector 50 with a conventional power socket 1 (curves A and B). The force F in N is plotted over the distance s in mm. Using a conventional plug connection, such as the common Connector (curve A), the force F varies very steeply with the distance s. The curves for closing the plug connection and opening the plug connection are essentially the same. The further development of the plug with a spring-loaded locking lug (curve B) produces a flatter curve for the force F varying with the distance s. The curve for the force F for releasing the connection is lower than the curve for the force F for closing the plug connection. Therefore, the release torque is lower than the tightening torque. Due to the above-mentioned path of the spiral groove 5 in the sleeve 3 with two areas of negative gradient, the power connector 50 with the power socket 1 according to the present invention (curve C) produces a force-displacement curve comprising two locking steps. In the locked state of the plug connection, a lower force F is generated in each case. Therefore, a certain force F must be overcome to open the connection or release the power plug 30 from the power socket 1 according to the present invention. This results in a better retention of the plug connection, which can significantly reduce the risk of unintentional separation of the plug connection.

[0049] at last, Fig. 9 The contact resistance of the power connector 50 with the power socket 1 according to the invention (bar graph I) is shown in comparison with the power connector 50 with a conventional plug connection (bar graphs II to IV). and power loss P V The bar graph according to I shows the contact resistance of the power connector 50 with the power socket 1 according to the present invention. and power loss P V . Contact resistance and power loss P V Both include low values. The bar graph according to II shows the traditional The contact resistance of the connector is fixed for optimal connection and power loss P V . Contact resistance and power loss P VThe values ​​of are comparable to those of the power socket 1 according to the invention according to I, for example, several tens of micro-ohms and several watts respectively. Connector (bar graph according to III), contact resistance and power loss P V The IV bar graph shows that the oxidized connector. Therefore, the contact resistance and power loss P V The power supply 1 according to the invention ensures that the contact resistance is minimized. and minimum power loss P V An optimal, stable and permanent connection is achieved, thereby minimizing the risk of damage to components of the power connector 50, the power cord 40 and the connected device, as well as the risk of injury to the user.

Claims

1. A power socket (1) for detachably connecting to a power plug (30), comprising a base (2) made of conductive material and a device (4) for connecting to a power cord (40), the base (2) having a hole (2') for receiving a substantially cylindrical pin (31) of the power plug (30), wherein a spiral groove (5) for receiving a locking nose (32) of the power plug (30) is arranged in the base (2), wherein the base (2) comprises a sleeve (3) having the spiral groove (5) and a receiving portion (3') for the sleeve (3), characterized in that The spiral groove (5) comprises at least two regions (a, c) with a positive gradient, and regions (b, d) with a negative gradient are arranged at the end of each region (a, c) with a positive gradient to form a corresponding locking step, the receiving portion (3') is formed of metal or a metal alloy, the receiving portion (3') has a sheath (13) of an electrically insulating material, and the sleeve (3) is formed of a material harder than the receiving portion (3').

2. The power socket (1) according to claim 1, characterized in that A spring element (6) is arranged in the receiving portion (3') of the sleeve (3) of the base body (2) for supporting the spring-mounted sleeve (3) in the axial direction (X) of the receiving portion (3').

3. The power socket (1) according to claim 2, characterized in that The spring element (6) is formed by at least one wire spring washer (7).

4. The power socket (1) according to claim 3, characterized in that The spring element (6) is formed by two wire spring washers (7) and a spacer ring (8) arranged between the wire spring washers (7).

5. The power socket (1) according to any one of claims 1 to 4, characterized in that The sleeve (3) comprises a positioning element (9), in particular an axial locking nose (10), in order to prevent a twisting of the receiving portion (3') relative to the base body (2).

6. The power socket (1) according to any one of claims 1 to 5, characterized in that The receiving portion (3') of the base body (2) consists of two parts (11, 12) that can be connected to each other. The two parts (11, 12) of the receiving portion (3') of the base body (2) can preferably be connected to each other by interference fit.

7. The power socket (1) according to any one of claims 1 to 6, characterized in that The housing (3') is formed from steel or a steel alloy, preferably brass or a brass alloy, and the sleeve (3) is formed from steel or a steel alloy.

8. The power socket (1) according to any one of claims 1 to 7, characterized in that The receiving portion (3') of the base body (2) comprises a flat front face (14) for contacting.

9. The power socket (1) according to claim 8, characterized in that The front face (14) of the receiving portion (3') comprises a coating (15), for example a silver coating.

10. The power socket (1) according to any one of claims 1 to 9, characterized in that The groove (5) in the sleeve (3) extends over a rotation angle (α) of 90° to 270°.

11. The power socket (1) according to any one of claims 1 to 10, characterized in that The gradient of the regions (a, c) of the groove (5) having a positive gradient is 1 mm to 8 mm per 360°.

12. The power socket (1) according to any one of claims 1 to 11, characterized in that The gradient of the area (b, d) of the groove (5) with negative gradient for forming the locking step is 0.1 mm to 20 mm, preferably 1 mm to 20 mm, more preferably 5 mm to 20 mm per 360°.

13. The power socket (1) according to any one of claims 1 to 12, characterized in that The spiral groove (5) comprises a region (e) without a gradient after the regions (b, d) with a negative gradient.

14. The power socket (1) according to any one of claims 1 to 13, characterized in that The means (4) for connecting to a power supply line (40) are formed by a threaded connection (16).

15. The power socket (1) according to any one of claims 1 to 14, characterized in that The receiving portion (3') of the base body (2) comprises a continuous hole (17) or the like in the axial direction (X) for guiding a protective gas (S) or the like.

16. A power connector (50) consisting of a power socket (1) and a corresponding power plug (30), the power plug (30) having a substantially cylindrical pin (31), characterized in that The power socket (1) is designed according to any one of claims 1 to 15.

17. The power connector (50) according to claim 16, characterized in that The sleeve (3) of the power socket (1) is formed of a harder material than the cylindrical pin (31) of the power plug (30).

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