Three-position switch and corresponding switch cabinet

Abstract

The embodiment of the invention relates to a three-position switch and a corresponding switch cabinet. The three-position switch generally comprises an isolating contact, a grounding contact and a moving contact. The moving contact includes a first end and a second end. The first end is connected with the base, the second end is opposite to the first end along the longitudinal extension direction of the moving contact, rotates around the first end along with the moving contact, and is switched among a switching-on station in contact with the isolating contact, a grounding station in contact with the grounding contact and a switching-off station out of contact with both the isolating contact and the grounding contact. The second end is provided with a first protrusion and an arc-resistant component. The first protrusion protrudes from the main surface of the moving contact and makes contact with the isolation contact when the second end is located at the switching-on station. An arc resistant member is disposed proximate the first protrusion and configured to withstand an arc when the first protrusion is proximate the ground contact. According to the embodiment of the invention, the moving contact is correspondingly modified, so that the consistency of the contact resistance before and after the experiment can be ensured.

Description

Technical Field

[0001] Exemplary embodiments of the present disclosure generally relate to the field of switchgear, and more particularly to a three-position switch and a corresponding switch cabinet. Background Art

[0002] A three-position switch is a switchgear with a closing position, an opening position, and a grounding position. This type of equipment is widely used in power systems. By switching between the three positions, the three-position switch can achieve the conversion of different states of the circuit. The three-position switch has the advantages of high safety and strong reliability.

[0003] However, in the existing three-position switch, the moving contact uses the same contact area when switching between the isolating contact and the grounding contact. In this case, after the grounding closing test is completed, the contact area of ​​the moving contact will be severely ablated. At this time, if the moving contact is switched to the isolating contact, the temperature rise test of the main circuit connected to the isolating contact often cannot meet the requirements of the industry standard. Therefore, an improved three-position switch is needed to improve its temperature rise characteristics. Summary of the invention

[0004] The exemplary embodiments of the present disclosure propose a solution that can at least solve the problems and / or potential problems in the prior art.

[0005] In a first aspect, a three-position switch is provided. The three-position switch comprises: an isolating contact; a grounding contact; and a moving contact, comprising: a first end connected to a base; a second end opposite to the first end along the longitudinal extension direction of the moving contact, and configured to switch between a closing position in contact with the isolating contact, a grounding position in contact with the grounding contact, and an opening position out of contact with both the isolating contact and the grounding contact as the moving contact rotates around the first end, wherein the second end is provided with: a first protrusion protruding from the main surface of the moving contact and configured to contact the isolating contact when the second end is in the closing position; and an arc-proof component provided near the first protrusion and configured to withstand an arc when the first protrusion is close to the grounding contact.

[0006] According to an exemplary embodiment of the present disclosure, by making corresponding changes to the moving contact, it can be ensured that the temperature rise test of the main circuit meets the requirements of the industry standard.

[0007] In some exemplary embodiments, the arc-proof component includes a protrusion protruding outward from the moving contact along a tangent of the moving contact in the rotation direction of the moving contact, so that the moving contact is L-shaped, and the arc-proof component is configured to contact the grounding contact when the second end is in the grounding position.

[0008] In some exemplary embodiments, the grounding contact includes a contact portion and an elastic portion arranged at the periphery of the contact portion, a gap is formed between the contact portion and the elastic portion for accommodating the protrusion of the moving contact, wherein the elastic portion is configured to press the protrusion against the contact portion when the protrusion is inserted into the gap.

[0009] In some exemplary embodiments, the arc-proof component includes a second protrusion protruding from the main surface of the moving contact and is configured to contact the ground contact when the second end is in the grounding position.

[0010] In some exemplary embodiments, the first protrusion and the second protrusion are arranged in a longitudinal extension direction of the moving contact.

[0011] In some exemplary embodiments, the grounding contact includes: a first section fixedly connected to the base; a second section adjacent to the first section and forming a gap between the first section and the second section; and a third section connecting the first section and the second section, thereby forming a U-shape with the first section and the second section, and the grounding contact is configured such that when the moving contact is in the grounding position, the first protrusion is in the gap and the second protrusion is in contact with the second section.

[0012] In some exemplary embodiments, the grounding contact includes: a contact base fixedly connected to the base; and a contact portion, which is plate-shaped and extends from the middle of the contact base, and the grounding contact is configured such that when the movable contact is in the grounding position, the first protrusion does not contact the contact portion and the second protrusion contacts the contact portion.

[0013] In some exemplary embodiments, the arc-proof component includes an extension portion fixedly disposed on the second end and extending from the moving contact, and the extension portion is configured to withstand an arc when the first protrusion approaches the ground contact.

[0014] In some exemplary embodiments, the arc-proof component includes a rotating body, the rotating body is pivoted to the body of the moving contact via an arc-proof pivot, and the rotating body is configured to withstand an arc when the first protrusion approaches the ground contact.

[0015] In some exemplary embodiments, the arc-resistant pivot also includes a torsion spring connected to the rotating body, which is configured to be compressed during the process of the moving contact and the grounding contact being out of contact, and to cause the rotating body to rotate under the action of an elastic restoring force after the moving contact and the grounding contact are out of contact.

[0016] In some exemplary embodiments, the arc-resistant component is made by embedding an ablation-resistant material into the moving contact.

[0017] In some exemplary embodiments, the three-position switch further comprises a voltage grading cover which is ellipsoidal or ring-shaped and is disposed on the second end of the moving contact and / or the isolating contact.

[0018] In a second aspect, a switch cabinet is provided, wherein the switch cabinet comprises the three-position switch according to the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The above and other objects, features and advantages of the present disclosure will become more apparent from the following detailed description of exemplary embodiments of the present disclosure with reference to the accompanying drawings, in which several embodiments of the present disclosure are explained by way of example in a non-limiting manner.

[0020] Figure 1 A perspective view of an illustrative switch cabinet according to an exemplary embodiment of the present disclosure is shown.

[0021] Figure 2 A front view of a schematic three-position switch according to a first exemplary embodiment of the present disclosure is shown.

[0022] Figure 3 Shows Figure 2 A perspective view of the moving contacts in a three-position switch.

[0023] Figure 4 Shows Figure 2 Front view of the moving contacts in a three-position switch.

[0024] Figure 5 Shows Figure 2 Perspective view of the grounding contact in a three-position switch.

[0025] Figure 6 A front view of a schematic three-position switch according to a second exemplary embodiment of the present disclosure is shown.

[0026] Figure 7 Shows Figure 6 A perspective view of the moving contacts in a three-position switch.

[0027] Figure 8 Shows Figure 6 Front view of the moving contacts in a three-position switch.

[0028] Fig. 9 Shows Figure 6 Schematic illustration of an alternative embodiment of a grounding contact in a three-position switch.

[0029] Fig.10 A front view of a schematic three-position switch according to a third exemplary embodiment of the present disclosure is shown.

[0030] Fig.11Shows Fig.10 A perspective view of the moving contacts in a three-position switch.

[0031] Fig.12 Shows Fig.10 Front view of the moving contacts in a three-position switch.

[0032] Fig.13 A front view of an illustrative three-position switch according to a fourth exemplary embodiment of the present disclosure is shown.

[0033] Fig.14 Shows Fig.13 A perspective view of the moving contacts in a three-position switch.

[0034] Fig.15 Shows Fig.13 Front view of the moving contacts in a three-position switch. DETAILED DESCRIPTION

[0035] The principles of the present disclosure will now be described with reference to the various example embodiments shown in the accompanying drawings. It should be understood that the description of these embodiments is only for the purpose of enabling those skilled in the art to better understand and further implement the exemplary embodiments disclosed herein, and is not intended to limit the scope of the disclosure in any way. It should be noted that similar or identical reference numerals may be used in the accompanying drawings, where feasible, and similar or identical reference numerals may represent similar or identical functions. Those skilled in the art can readily recognize that alternative embodiments of the structures and methods described in the present disclosure may be used from the following description without departing from the principles of the present disclosure.

[0036] The terms "including" and variations thereof as used herein should be understood as open-ended terms, meaning "including but not limited to." The term "based on" should be understood as "based at least in part on." The terms "one embodiment" and "embodiment" should be understood as "at least one embodiment." The term "another embodiment" should be understood as "at least another embodiment." The terms "first," "second," etc. may refer to the same or different objects. The following text may also include other explicit and implied definitions. Unless the context indicates otherwise, the definitions of terms are consistent throughout the specification.

[0037] As mentioned above, there is still room for improvement in the existing three-position switch. The isolating switch and the grounding switch of the existing three-position switch share a moving knife, and the isolating switch and the grounding switch share the same contact area when they are closed. After the grounding closing test of the grounding switch is completed, the contact area of ​​the moving knife is severely ablated, and then when the isolating switch is closed, the contact resistance will increase significantly, which poses a serious challenge to the temperature rise test of the main circuit.

[0038] At least to overcome the above defects, the exemplary embodiments disclosed herein provide an improved three-position switch and a corresponding switch cabinet. According to the exemplary embodiments, by optimizing the structure of the moving contact or the grounding contact, the main circuit temperature rise test of the three-position switch can meet the requirements of the industry standard.

[0039] The following will be based on Figures 1 to 15 The exemplary embodiments are described in more detail, wherein Figure 1 shows a perspective view of a switch cabinet 2 according to an exemplary embodiment of the present disclosure, Figures 2 to 5 1 shows various views of a three-position switch 1 according to a first exemplary embodiment of the present disclosure, Figures 6 to 9 1 shows various views of a three-position switch 1 ′ according to a second exemplary embodiment of the present disclosure, Figures 10 to 12 1 shows various views of a three-position switch 1 ″ according to a third exemplary embodiment of the present disclosure, Figures 13 to 15 Various views of a three-position switch 1 ″′ according to a fourth exemplary embodiment of the present disclosure are shown.

[0040] like Figure 1 As shown, the switch cabinet 2 includes a three-position switch 3. The three-position switch 3 integrates the functions of both the isolating switch and the earthing switch, and has a closing position, an opening position and an earthing position. Figure 1 The three-position switch 3 in the figure can be Figures 2 to 5 The three-position switch 1 can also be Figures 6 to 9 The three-position switch 1' can also be Figures 10 to 12 A three-position switch 1", or it can be Figures 13 to 15 Three-position switch 1”’. This will be described in detail below.

[0041] Combine the following Figures 2 to 5A three-position switch 1 according to a first exemplary embodiment of the present disclosure is described. As shown, the three-position switch 1 generally includes an isolating contact 11, a grounding contact 12, and a moving contact 30 that can be switched between the isolating contact 11 and the grounding contact 12, which are fixedly arranged in the switch cabinet 2. As shown, the moving contact 30 can be formed by connecting two copper bars and is generally rod-shaped. This means that the moving contact 30 has an elongated shape, and its size in the longitudinal extension direction is significantly larger than the sizes of the other two dimensions. As shown, the moving contact 30 has a first end 31 and a second end 32 that are arranged oppositely along its longitudinal extension direction. The first end 31 can be connected to a base 90 arranged in the switch cabinet 2. A pivot can be provided on the first end 31, so that the moving contact 30 can pivot relative to the base 90 of the switch cabinet 2 around the pivot of the first end 31. As a result of the pivoting of the moving contact 30, the second end 32 can move back and forth between the isolating contact 11 and the grounding contact 12 along the rotation direction shown by the arrow R. When the second end 32 is in contact with the isolating contact 11, the three-position switch 1 is in the closing position. When the second end 32 is in contact with the grounding contact 12, the three-position switch 1 is in the grounding position. When the second end 32 is out of contact with both the isolating contact 11 and the grounding contact 12 (i.e. Figure 2 As shown in the figure, the three-position switch 1 is in the opening position. Thus, through the back and forth movement of the moving contact 30, the three-position switch 1 can be switched back and forth between the closing position, the grounding position and the opening position, thereby realizing the function of the three-position switch 1.

[0042] like Figure 3 and Figure 4 As shown, a first protrusion 33 is provided on the second end 32. The first protrusion 33 may be a bulge protruding from the main surface 300 of the moving contact 30 in a direction substantially perpendicular to the main surface 300. The position of the first protrusion 33 may be set such that, as the moving contact 30 rotates, the first protrusion 33 can contact the isolation contact 11 when the second end 32 is in the closing position, thereby realizing the isolation closing state.

[0043] An arc-proof component 34 is also provided on the second end 32. Figure 3 and Figure 4 As shown, the arc-proof component 34 may be a protrusion 340 protruding outward from the moving contact 30. As shown, the protrusion 340 protrudes outward substantially along a tangent line of the rotation direction of the moving contact 30. Figure 4 As shown, the moving contact 30 is generally in an "L" shape. The protrusion 340 is configured to contact the grounding contact 20 when the second end 32 is in the grounding position. Figures 2 to 5In the first embodiment shown, when the closing operation is realized, the first protrusion 33 contacts the isolation contact 11; and when the grounding operation is realized, the protrusion 340 of the moving contact 30 contacts the grounding contact 12. In this way, the contact areas of the closing operation and the grounding operation are separated, so that when the grounding operation is realized, only the protrusion 340 will be ablated, and the first protrusion 33 used to realize the closing operation can be completely unaffected by the grounding operation, thereby ensuring that the contact resistance is not affected during the isolation closing, and ensuring that the temperature rise of the main circuit after the isolation closing meets the requirements of the industry standard.

[0044] like Figure 3 to Figure 4 As shown, two first protrusions 33 may be provided on the main surface 300 of the moving contact 30. It should be understood that this is merely illustrative, and other numbers of first protrusions 33 may be provided on the moving contact 30, which may be adjusted according to specific use environments and design requirements, and such embodiments fall within the scope of the present disclosure.

[0045] Figure 5 A perspective view of a grounding contact 12 of a three-position switch 1 according to a first exemplary embodiment of the present disclosure is shown. As shown, the grounding contact 12 includes a contact portion 120 and an elastic portion 122. The elastic portion 122 is generally in the shape of a "F" and is arranged adjacent to the contact portion 120. The elastic portion 122 is partially arranged at the periphery of the contact portion 120, and a gap G is formed between the elastic portion 122 and the contact portion 120 for receiving the protrusion 340 of the moving contact 30. The elastic portion 122 is made of a material having certain elastic properties. When the moving contact 30 performs a grounding operation, the moving contact 30 rotates around the first end 31, and the protrusion 340 of the moving contact 30 moves toward the grounding contact 12, and enters the gap G between the contact portion 120 and the elastic portion 122 of the grounding contact 12 and pushes the elastic portion 122 away from the contact portion 120. After the protrusion 340 of the moving contact 30 completely enters the gap G, the elastic portion 122 can firmly press the protrusion 340 of the moving contact 30 against the contact portion 120 under the action of the elastic restoring force, thereby achieving a reliable electrical connection.

[0046] like Figure 3 As shown, the moving contact 30 also includes a voltage grading cover 36 which may be arranged on the second end 33 thereof. For example, in the illustrated embodiment, the voltage grading cover 36 may be ellipsoidal, and its size in the longitudinal extension direction of the moving contact 30 may be larger than the size in other directions, so as to match the shape of the moving contact 30. In other embodiments, the voltage grading cover 36 may also be an annular shape with a recess in the middle. The voltage grading cover 36 may be installed on the moving contact 30 in any feasible manner, such as riveting, etc. By providing the voltage grading cover 36, a uniform field strength can be provided on the moving contact 30 to ensure insulation performance.

[0047] like Figure 2 As shown, a voltage grading cover 16 may also be provided on the isolation contact 11, and its shape may be similar to the voltage grading cover 36 of the moving contact 30, which will not be described in detail here. Of course, the specific shape of the voltage grading cover 16 on the isolation contact 11 can be adapted according to the actual shape of the isolation contact 11, so as to better match the appearance of the isolation contact 11 and the actual use scenario. By providing the voltage grading cover 16, a uniform field strength can be provided on the isolation contact 11 to ensure insulation performance.

[0048] Combine the following Figures 6 to 9 A three-position switch 1' according to a second exemplary embodiment of the present disclosure is described. Similar to the first exemplary embodiment described above, the three-position switch 1' generally includes an isolating contact 11', a grounding contact 12', and a moving contact 30' that can be switched between the isolating contact 11' and the grounding contact 12', which are fixedly arranged in the switch cabinet 2. A first protrusion 33' is also provided on the second end 32' of the moving contact 30', which contacts the isolating contact 11' when the second end 32' is in the closing position.

[0049] and Figures 2 to 5 The difference from the first exemplary embodiment shown is that the arc-proof component 34' provided on the second end 32' is a second protrusion 340' provided adjacent to the first protrusion 33', and when the second end 32' is in the grounding position, the second protrusion 340' contacts the grounding contact 20'. The second protrusion 340' can protrude from the main surface 300' of the moving contact 30' in a direction substantially perpendicular to the main surface 300'. That is, for Figures 6 to 9 In the second embodiment shown, when the closing operation is realized, the first protrusion 33' contacts the isolation contact 11'; and when the grounding operation is realized, the second protrusion 340' on the moving contact 30' contacts the grounding contact 12'. In this way, when the grounding operation is realized, only the second protrusion 340' will be ablated, and the first protrusion 33' used for the closing operation can be completely unaffected by the grounding operation, thereby ensuring that the temperature rise of the main circuit after the isolation closing meets the requirements of the industry standard.

[0050] like Figure 7 and Figure 8 As shown, the second protrusion 340' can be arranged opposite to the first protrusion 33' and arranged at a position closer to the first end 31'. The second protrusion 340' can adopt the same or similar shape as the first protrusion 33'. Therefore, only the second protrusion 340' can be provided without changing the basic shape of the moving contact 30'. In other words, in the second embodiment, as Figure 8As shown, the basic shape of the moving contact 30' is a simple rod shape. Therefore, only a slight modification of the moving contact 30' is required to achieve the expected temperature rise effect. In a scenario with a compact spatial layout, such a slight modification of the moving contact 30' will not cause the redesign of other associated components, and thus has a greater cost advantage.

[0051] In addition, since the moving contact 30' still maintains a relatively simple shape without too many chamfered structures, such a smooth structure can ensure good insulation performance. Especially in the air insulation scenario, this structure can have a more obvious insulation performance advantage. In addition, if Figure 8 As shown, the first protrusion 33' and the second protrusion 340' are arranged in the longitudinal extension direction of the moving contact 30'. It should be noted that, since the spacing between the two first protrusions 33' and the spacing between the two second protrusions 340' are very small compared to the longitudinal dimension of the moving contact 30', it can be considered that the distance between the two first protrusions 33' and the two second protrusions 340' and the longitudinal axis of the moving contact 30' is very small. Since the moving contact 30' adopts a rod-shaped shape, only one blade (i.e., the second end 32') is provided to achieve switching between the isolation contact 11' and the grounding contact 12'. Compared with the case of using multiple blades, the force on the moving contact 30' during the movement process will be more concentrated, so that the mechanical properties of the moving contact 30' are better and the working process is more reliable and stable.

[0052] In the second embodiment, various methods can be envisioned to implement the electrical function of the ground contact 12'. Figure 6 A schematic detailed structure of the grounding contact 12' of the second embodiment is described. As shown, the grounding contact 12' is generally "U"-shaped and specifically includes: a first section 121' fixedly connected to the base 90' ​​on the switch cabinet, a second section 122' adjacent to the first section 121', and a third section 123' connected to the first section 121' and the second section 122'. A gap S' is formed between the first section 121' and the second section 122'. When the moving contact 30' moves along Figure 6 When the direction shown is turned counterclockwise and the ground contact 12' is approached, the reference Figure 8 , the second protrusion 340' on the moving contact 30' will be connected to the second section 122' of the grounding contact 12', so as to realize the connection between the moving contact 30' and the grounding contact 12'. At the same time, the first protrusion 33' will fall into the gap S' between the first section 121' and the second section 122', and the first protrusion 33' will not contact the grounding contact 12'. In this way, when the grounding operation is realized, only the second protrusion 340' on the moving contact 30' is in contact with the grounding contact 12'.

[0053] Refer to the following Fig. 9 Another schematic detailed structure of the grounding contact 12' of the second embodiment is described. As shown, the grounding contact 12' generally includes a contact base 124' and a contact portion 125' extending from the middle portion of the contact base 124'. The contact base 124' is fixedly connected to the base 90', and the contact portion 125' is plate-shaped, and the contact portion 125' and the contact base 124' are generally T-shaped. The position of the grounding contact 12' can be appropriately set on the base 90' ​​so that the first protrusion 33' on the moving contact 30' does not contact the contact portion 125', and the second protrusion 340' on the moving contact 30' contacts the contact portion 125'. Combined with reference Figure 8 When the moving contact 30' rotates and approaches the grounding contact 12', the first protrusion 33' on the moving contact 30' can avoid the contact portion 125' of the grounding contact 12' and does not contact it, but the second protrusion 340' on the moving contact 30' can contact the contact portion 125' of the grounding contact 12'. In this way, when the grounding operation is implemented, only the second protrusion 340' on the moving contact 30' is in contact with the grounding contact 12'.

[0054] Understandably, Figure 6 and Fig. 9 What are shown are only two feasible forms of the grounding contact 12 ′. Those skilled in the art may also conceive of other forms of the grounding contact 12 ′ based on actual application scenarios.

[0055] like Figure 7 As shown, the moving contact 30' also includes a voltage-equalizing cover 36' which may be arranged on the second end 33' thereof. For example, in the illustrated embodiment, the voltage-equalizing cover 36' may be ellipsoidal in shape, and its dimension in the longitudinal extension direction of the moving contact 30' may be larger than the dimension in other directions, so as to match the shape of the moving contact 30'. In other embodiments, the voltage-equalizing cover 36' may also be an annular shape with a recess in the middle. The voltage-equalizing cover 36' may be installed on the moving contact 30' in any feasible manner, such as riveting, etc. By providing the voltage-equalizing cover 36', a uniform field strength may be provided on the moving contact 30' to ensure insulation performance.

[0056] like Figure 6 As shown, a voltage grading cover 16' may also be provided on the isolation contact 11', and its shape may be similar to the voltage grading cover 36' of the moving contact 30', which will not be described in detail here. Of course, the specific shape of the voltage grading cover 16' on the isolation contact 11' may be adapted according to the actual shape of the isolation contact 11', so as to better match the appearance of the isolation contact 11' and the actual use scenario. By providing the voltage grading cover 16', a uniform field strength can be provided on the isolation contact 11' to ensure insulation performance.

[0057] According to the first exemplary embodiment and the second exemplary embodiment of the present disclosure, an arc-proof component 34 (the protrusion 340 in the first exemplary embodiment and the second protrusion 340' in the second exemplary embodiment) independent of the first protrusions 33, 33' is provided to withstand the arc, and the corresponding arc-proof component 34 contacts the grounding contacts 12, 12' during the grounding operation, thereby distinguishing the area used for the grounding operation (i.e., the arc-proof component 34, the protrusion 340 in the first exemplary embodiment and the second protrusion 340' in the second exemplary embodiment) from the area used for the isolation operation (i.e., the first protrusions 33, 33'), so that the erosion of the contact area during the grounding operation will not lead to an increase in the contact resistance during the isolation closing.

[0058] Combine the following Figures 10 to 12 A three-position switch 1" according to a third exemplary embodiment of the present disclosure is described. Similar to the first and second exemplary embodiments described above, the three-position switch 1" generally includes an isolating contact 11" fixedly arranged in a switch cabinet 2, a grounding contact 12", and a movable contact 30" capable of switching between the isolating contact 11" and the grounding contact 12". A first protrusion 33" is also provided on the second end 32" of the movable contact 30", which contacts the isolating contact 11" when the second end 32" is in the closing position.

[0059] An arc-proof component 34" is further provided on the second end 32" of the moving contact 30". The arc-proof component 34" is fixedly provided on the second end 32". The arc-proof component 34" is used to start an arc earlier than the first protrusion 33" during the grounding operation, so as to withstand the influence of the arc, so as to reduce the ablation of the first protrusion 33" by the arc generated during the grounding operation. Different from the first exemplary embodiment and the second exemplary embodiment described above, Figures 10 to 12 In the third embodiment shown, the first protrusion 33" is used for both the closing operation with the isolating contact 11", and the grounding operation with the grounding contact 12". For the third embodiment, although the first protrusion 33" is in contact with the corresponding isolating contact 11" and the grounding contact 12" during the closing operation and the grounding operation, the presence of the arc-proof component 34" can reduce the negative effect of the arc on the first protrusion 33" during the grounding operation. The dedicated arc-proof component 34" can ensure that the temperature rise of the main circuit can meet the requirements of industry standards after the isolation closing operation is achieved.

[0060] exist Fig.11 and Fig.12In the illustrated embodiment, the arc-resistant component 34" may be an extension 340" extending from the moving contact 30". In other embodiments, the arc-resistant component 34" may be achieved by embedding an ablation-resistant material into the moving contact 30". In a further embodiment, the ablation-resistant material may be a copper-chromium alloy. Of course, the materials listed here are merely exemplary and non-restrictive. The ablation-resistant material may be other materials, and the specific material is not limited to the embodiments of the present disclosure.

[0061] like Fig.11 As shown, the moving contact 30" also includes a voltage-equalizing cover 36" arranged on the second end 33" thereof. For example, in the illustrated embodiment, the voltage-equalizing cover 36" may be ellipsoidal, and its dimension in the longitudinal extension direction of the moving contact 30" may be larger than its dimensions in other directions, so as to match the outer shape of the moving contact 30". In other embodiments, the voltage-equalizing cover 36" may also be an annular shape with a recessed portion in the middle. The voltage-equalizing cover 36" may be installed on the moving contact 30" in any feasible manner, such as riveting, etc. By providing the voltage-equalizing cover 36", a uniform field strength may be provided on the moving contact 30", thereby ensuring insulation performance.

[0062] like Fig.10 As shown, a voltage grading cover 16" may also be provided on the isolation contact 11", and its shape may be similar to the voltage grading cover 36" of the moving contact 30", which will not be described in detail here. Of course, the specific shape of the voltage grading cover 16" on the isolation contact 11" may be adapted according to the actual shape of the isolation contact 11", so as to better match the appearance of the isolation contact 11" and the actual usage scenario. By providing the voltage grading cover 16", a uniform field strength can be provided on the isolation contact 11", ensuring insulation performance.

[0063] Combine the following Figures 13 to 15 A three-position switch 1''' according to a fourth exemplary embodiment of the present disclosure is described. Similar to the first to third exemplary embodiments described above, the three-position switch 1''' generally includes an isolating contact 11''', a grounding contact 12''', and a movable contact 30''' capable of switching between the isolating contact 11''' and the grounding contact 12''', which are fixedly arranged in the switch cabinet 2. A first protrusion (not shown) that contacts the isolating contact 11''' when the second end 32''' is in the closing position is also provided on the second end 32'' of the movable contact 30'''.

[0064] like Fig.14 and Fig.15 As shown, an arc-proof component 34' is also provided on the second end 32'' of the moving contact 30''. Figures 10 to 12Similar to the third exemplary embodiment shown, the arc-proof component 34'' also functions to start the arc earlier than the first protrusion 33'' during the grounding operation, and the arc-proof component 34'' is affected by the arc, thereby reducing the ablation of the first protrusion 33'' by the arc generated during the grounding operation. Figures 10 to 12 The third embodiment shown is further similar in that for Figures 13 to 15 In the fourth embodiment shown, the first protrusion 33"' is used for both the closing operation with the isolating contact 11"' and the grounding operation with the grounding contact 12"'. For the fourth embodiment, although the first protrusion 33"' is in contact with the corresponding isolating contact 11"' and the grounding contact 12"' when implementing the closing operation and the grounding operation, the presence of the arc-proof component 34"' can reduce the negative effect of the arc on the first protrusion 33"' during the grounding operation. The special arc-proof component 34"' can ensure that the temperature rise of the main circuit can meet the requirements of the industry standards after the isolation closing operation is realized.

[0065] However, with Figures 10 to 12 The third exemplary embodiment shown differs in that Figures 13 to 15 The arc-proof component 34'' shown in the figure is a rotating body 340'' pivoted to the main body of the moving contact 30''' through an arc-proof pivot 35''. The rotating body 340'' can rotate around the arc-proof pivot 35'', and a torsion spring (not shown) can be provided on the arc-proof pivot 35'' to cooperate with the rotation of the rotating body 340''. Specifically, during the grounding operation, the moving contact 30'' rotates toward the grounding contact 12'', and the rotating body 340'' first arcs. As the moving contact 30'' continues to rotate, during the grounding closing process, the rotating body 340'' swings around the arc-proof pivot 35'' and compresses the torsion spring installed to the arc-proof pivot 35'', which does not affect the contact between the first protrusion 33'' and the grounding contact 12''. After the moving contact 30'' is out of contact with the grounding contact 12'', the torsion spring can be reset under the action of elasticity to return to its initial state.

[0066] like Fig.14 As shown, the moving contact 30"' also includes a voltage-equalizing cover 36"' arranged on the second end 33"' thereof. For example, in the illustrated embodiment, the voltage-equalizing cover 36"' may be ellipsoidal, and its dimension in the longitudinal extension direction of the moving contact 30"' may be larger than the dimensions in other directions, so as to match the outer shape of the moving contact 30"'. In other embodiments, the voltage-equalizing cover 36"' may also be an annular shape with a recessed portion in the middle. The voltage-equalizing cover 36"' may be installed on the moving contact 30"' in any feasible manner, such as riveting, etc. By providing the voltage-equalizing cover 36"', a uniform field strength may be provided on the moving contact 30"' to ensure insulation performance.

[0067] like Fig.13 As shown, a voltage grading cover 16'" may also be provided on the isolation contact 11'", and its shape may be similar to that of the voltage grading cover 36'" of the movable contact 30'" and will not be described in detail here. Of course, the specific shape of the voltage grading cover 16'" on the isolation contact 11'" may be adapted according to the actual shape of the isolation contact 11'" so as to better match the appearance of the isolation contact 11'" and the actual usage scenario. By providing the voltage grading cover 16'" it is possible to provide a uniform field strength on the isolation contact 11'" to ensure insulation performance.

[0068] According to the third exemplary embodiment and the fourth exemplary embodiment of the present disclosure, a special arc-proof component 34 (an extension portion 340" in the third exemplary embodiment and a rotating body 340"' in the second exemplary embodiment) independent of the first protrusions 33", 33"' is provided on the movable contact 30", 30"' to withstand the arc. During the grounding operation, the corresponding arc-proof component 34 first contacts the grounding contact 12", 12"', so that the starting arc-strike position appears on the corresponding arc-proof component 34 and thus the arc ablation area is also concentrated on the arc-proof component 34, thereby reducing the ablation of the first protrusions 33", 33"' during the grounding operation, so that the contact resistance will not increase during the isolation closing.

[0069] According to various embodiments of the present disclosure, by making corresponding changes to the moving contact and the grounding contact, it can be ensured that the temperature rise test of the main circuit meets the requirements of the industry standards.

[0070] Various embodiments of the present disclosure have been described above, and the above explanations are illustrative rather than exhaustive and are not limited to the disclosed embodiments. Many changes and modifications are clear to those of ordinary skill in the art without departing from the scope and spirit of each explained embodiment. The choice of terms in the text is intended to best explain the principles of each embodiment, practical applications, or technical improvements on the market, or to make each embodiment disclosed in the text understandable to those of ordinary skill in the art.

Claims

1. A three-position switch, comprising: isolating contacts; earthing contacts; and a moving contact, comprising: a first end coupled to a base; a second end opposite to the first end along a longitudinal extension direction of the moving contact and configured to switch between a closing position in contact with the isolating contacts, an earthing position in contact with the earthing contacts, and an opening position disengaged from both the isolating contacts and the earthing contacts as the moving contact rotates about the first end, wherein there is provided on the second end: a first protrusion protruding from a main surface of the moving contact and configured to contact the isolating contacts when the second end is in the closing position; and an arc-resistant member provided near the first protrusion and configured to withstand an electric arc when the first protrusion approaches the earthing contacts.

2. The three-position switch according to claim 1, wherein the arc-resistant member comprises a protrusion protruding outward from a tangent of the moving contact along a rotation direction of the moving contact, such that the moving contact is in an L shape, and the arc-resistant member is configured to contact the earthing contacts when the second end is in the earthing position.

3. The three-position switch according to claim 2, wherein the earthing contacts comprise a contact head portion and an elastic portion provided around the contact head portion, and a gap is formed between the contact head portion and the elastic portion for receiving the protrusion of the moving contact, wherein the elastic portion is configured to press the protrusion against the contact head portion when the protrusion is inserted into the gap.

4. The three-position switch according to claim 1, wherein the arc-resistant member comprises a second protrusion protruding from the main surface of the moving contact and configured to contact the earthing contacts when the second end is in the earthing position.

5. The three-position switch according to claim 4, wherein the first protrusion and the second protrusion are provided in the longitudinal extension direction of the moving contact.

6. The three-position switch according to claim 4 or 5, wherein the earthing contacts comprise: a first section fixedly connected to a base; a second section adjacent to the first section and having a gap formed between the first section and the second section; and a third section connecting the first section and the second section to form a U shape with the first section and the second section, the earthing contacts being configured such that when the moving contact is in the earthing position, the first protrusion is within the gap and the second protrusion contacts the second section.

7. The three-position switch according to claim 4 or 5, wherein the earthing contacts comprise: a contact base fixedly connected to the base; and a contact portion in a plate shape and extending from a middle of the contact base, the earthing contacts being configured such that when the moving contact is in the earthing position, the first protrusion does not contact the contact portion and the second protrusion contacts the contact portion.

8. The three-position switch according to claim 1, wherein the arc-resistant component includes an extension portion fixedly provided at the second end and extending from the moving contact, and the extension portion is configured to withstand an arc when the first protrusion approaches the grounding contact.

9. The three-position switch according to claim 1, wherein the arc-resistant component includes a rotating body pivotally connected to the body of the moving contact via an arc-resistant pivot, and the rotating body is configured to withstand an arc when the first protrusion approaches the grounding contact.

10. The three-position switch according to claim 9, wherein the arc-resistant pivot further includes a torsion spring coupled to the rotating body, the torsion spring is configured to be compressed during the process of the moving contact disengaging from the grounding contact, and to rotate the rotating body under the action of an elastic restoring force after the moving contact disengages from the grounding contact.

11. The three-position switch according to any one of claims 8 to 10, wherein the arc-resistant component is made by embedding an ablation-resistant material into the moving contact.

12. The three-position switch according to any one of claims 1-5, 8-10, further comprising a grading cover, the grading cover being ellipsoidal or annular and disposed at the second end of the moving contact and / or on the isolating contact.

13. A switchgear cabinet, comprising the three-position switch according to any one of claims 1 to 12.

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