Patent Description:
In an electrical switch, when the movable contact and the stationary contact are separated, an electric arc will be generated. In order to extinguish the arc as soon as possible, it is needed to let the arc enter an arc-extinguishing chamber composed of a plurality of grids. After the arc enters the grids, the arc is divided into a plurality of short arcs by the grids, so that the arc voltage of the total arc rises sharply to help extinguish the arc.

In the existing art, the permanent magnet arc-extinguishing method is mainly adopted, and the arc moves towards the arc-extinguishing chamber under the action of the magnetic field of the arc-extinguishing chamber. However, for the DC isolating switch with large working voltage that has appeared in the market at present, the traditional arc-extinguishing chamber structure and arc-extinguishing method have been difficult to meet its performance requirements. In addition, because many parts of the switch are made of plastic, high-temperature gas will be generated under the action of arc, so it is needed to set up airways and exhaust ports reasonably so that the gas can be discharged from the housing of the switch as soon as possible to prevent the high-temperature gas from accumulating in the housing and damaging the parts in the switch.

Document <CIT> discloses an isolating switch according to the preamble of claim <NUM>.

Therefore, the purpose of the present disclosure is to provide an improved isolating switch structure that can at least partially solve the above problems and is expected to enhance the arc extinguishing performance of the arc extinguishing chamber and prolong the electrical life of the isolating switch.

An isolating switch according to the present disclosure includes: a housing a first wall, a second wall, a third wall and a fourth wall, the first wall and the second wall being arranged opposite to each other, the third wall and the fourth wall being arranged opposite to each other and connecting the first wall to the second wall respectively; a movable contact assembly, including a movable contact bracket and a first movable contact arranged on the movable contact bracket, the movable contact bracket being pivotally arranged in the housing, and the first movable contact being able to pivot together with the movable contact bracket; a first stationary contact, fixedly arranged in the housing at a side close to the first wall and being able to contact and separate from the first movable contact; a first arc-extinguishing chamber, arranged in the housing at a side close to the third wall and including a plurality of arc-extinguishing grids, which are sequentially arranged from a position close to the first stationary contact toward a side of the second wall; the housing is provided with a first exhaust port, a second exhaust port and a third exhaust port, the first exhaust port and the second exhaust port are arranged on the first wall, the first exhaust port is closer to the first stationary contact than the second exhaust port, the second exhaust port is arranged between the first exhaust port and the third wall, and the third exhaust port is arranged on the second wall and adjacent to an arc-extinguishing grid closest to the second wall in the first arc-extinguishing chamber.

According to a preferable embodiment of the present disclosure, the isolating switch further includes a first airway wall, one end of the first airway wall is adjacent to and aligned with a third or fourth arc-extinguishing grid close to the first stationary contact in the first arc-extinguishing chamber, and the other end of the first airway wall is arranged between the first exhaust port and the second exhaust port.

According to a preferable embodiment of the present disclosure, the isolating switch further includes a second airway wall, one end of the second airway wall is arranged between the first exhaust port and the second exhaust port, and the other end of the second airway wall extends along a direction towards the third exhaust port and is connected to the third wall, wherein a depression or a through hole is arranged on the second airway wall at a position facing the second exhaust port, so that gas generated in the housing is able to be exhausted from the second exhaust port.

According to a preferable embodiment of the present disclosure, the isolating switch further includes a third airway wall, one end of the third airway wall is adjacent to an arc-extinguishing grid closest to the second wall in the first arc-extinguishing chamber, and the other end of the third airway wall is adjacent to the third exhaust port.

According to a preferable embodiment of the present disclosure, the isolating switch further includes a fourth airway wall, one end of the fourth airway wall is arranged on the third wall and adjacent to a position where the second airway wall and the third wall are connected, and the other end of the fourth airway wall is adjacent to the second exhaust port.

According to a preferable embodiment of the present disclosure, the first airway wall, the second airway wall, the third airway wall and the fourth airway wall form a smooth curve profile.

According to a preferable embodiment of the present disclosure, the first airway wall and the second airway wall are connected and form a smooth curve profile.

According to a preferable embodiment of the present disclosure, the plurality of arc-extinguishing grids in the first arc-extinguishing chamber are arranged along an arc profile.

According to a preferable embodiment of the present disclosure, an arc-extinguishing grid closest to the first stationary contact among the plurality of arc-extinguishing grids in the first arc-extinguishing chamber is in contact with the first stationary contact.

According to a preferable embodiment of the present disclosure, an angle between arc-extinguishing grid closest to the first stationary contact among the plurality of arc-extinguishing grids in the first arc-extinguishing chamber and a contact surface of the first stationary contact is in a range of <NUM>-<NUM> degrees.

According to a preferable embodiment of the present disclosure, the plurality of arc-extinguishing grids in the first arc-extinguishing chamber are divided into a first part close to the first wall and a second part close to the second wall, arc-extinguishing grids of one of the first part and the second part are arranged in a straight line, and arc-extinguishing grids of the other one of the first part and the second part are arranged in an arc profile.

According to a preferable embodiment of the present disclosure, the isolating switch further includes at least one connection plate extending along an arrangement direction of the plurality of arc-extinguishing grids in the first arc-extinguishing chamber, and the plurality of arc-extinguishing grids in the first arc-extinguishing chamber are vertically fixed to the at least one connection plate.

According to a preferable embodiment of the present disclosure, the isolating switch further includes: a second movable contact, arranged on the movable contact bracket, the second movable contact being able to pivot together with the movable contact bracket; a second stationary contact, fixedly arranged in the housing at a side close to the second wall and being able to contact and separate from the first movable contact; and a second arc-extinguishing chamber, arranged in the housing at a side close to the fourth wall and including a plurality of arc-extinguishing grids, sequentially arranged from a position close to the second stationary contact toward a side of the first wall, the housing is also provided with a fourth exhaust port, a fifth exhaust port and a sixth exhaust port, the fourth exhaust port and the fifth exhaust port are arranged on the second wall; the fourth exhaust port is closer to the second stationary contact than the fifth exhaust port; the fifth exhaust port is arranged between the fourth exhaust port and the fourth wall; and the sixth exhaust port is arranged on the first wall and adjacent to an arc-extinguishing grid closest to the first wall in the second arc-extinguishing chamber.

According to a preferable embodiment of the present disclosure, the first stationary contact and the second stationary contact are centrally symmetrical with respect to a rotation axis of the movable contact bracket, the first arc-extinguishing chamber and the second arc-extinguishing chamber are centrally symmetrical with respect to the rotation axis of the movable contact bracket, and a position of the first exhaust port and a position of the fourth exhaust port are centrally symmetrical with respect to the rotation axis of the movable contact bracket, a position of the second exhaust port and a position of the fifth exhaust port are centrally symmetrical with respect to the rotation axis of the movable contact bracket, and a position of the third exhaust port and a position of the sixth exhaust port are centrally symmetrical with respect to the rotation axis of the movable contact bracket.

In order to make the purpose, technical scheme and advantages of the technical scheme of the present disclosure more clear, the technical solution of the embodiment of the present disclosure will be described clearly and completely with the accompanying drawings of the specific embodiment of the present disclosure. Like reference numerals in the drawings represent like parts.

Unless otherwise defined, technical terms or scientific terms used here shall have their ordinary meanings as understood by people with ordinary skills in the field to which this disclosure belongs. The "first", "second" and similar words used in the description and claims of the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, similar words such as "a" or "an" do not necessarily mean quantitative restrictions. Similar words such as "including" or "containing" mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Similar words such as "connect" or "connected" are not limited to physical or mechanical connection, but can include electrical connection, whether direct or indirect. "Up", "Down", "Left" and "Right" are only used to indicate the relative positional relationship. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

Hereinafter, the present disclosure will be described in detail by describing exemplary embodiments.

<FIG> shows a schematic diagram of a first embodiment of an isolating switch according to the present disclosure. As illustrated by the figure, a housing <NUM> of an isolating switch is roughly square, including a first wall <NUM>, a second wall <NUM>, a third wall <NUM> and a fourth wall <NUM>, the first wall <NUM> and the second wall <NUM> are arranged opposite to each other, the third wall <NUM> and the fourth wall <NUM> are arranged opposite to each other and respectively connect the first wall <NUM> to the second wall <NUM>. A movable contact assembly is arranged at a center position of the housing <NUM>, and includes a movable contact bracket <NUM>, a first movable contact <NUM> and a second movable contact <NUM> arranged on the movable contact bracket <NUM>, the movable contact bracket <NUM> is able to pivot around its center, and the first movable contact <NUM> and the second movable contact <NUM> are able to pivot together with the movable contact bracket <NUM>. The isolating switch includes a first stationary contact <NUM> and a second stationary contact <NUM>, the first stationary contact <NUM> is arranged at a side of the first wall <NUM> and the second stationary contact <NUM> is arranged at a side of the second wall <NUM>. With the pivoting of the movable contact bracket <NUM>, the first movable contact <NUM> can contact and separate from the first stationary contact <NUM>, the second movable contact <NUM> can contact and separate from the second stationary contact <NUM>. The isolating switch also includes a first arc-extinguishing chamber <NUM> and a second arc-extinguishing chamber <NUM>. As can be seen from the figure, the first arc-extinguishing chamber <NUM> is arranged in the housing <NUM> at a side close to the third wall <NUM>, a plurality of arc-extinguishing grids <NUM> included in the first arc-extinguishing chamber <NUM> are sequentially arranged from a position close to the first stationary contact <NUM> towards the second wall <NUM> and arranged substantially in an arc profile. The second arc-extinguishing chamber <NUM> is arranged in the housing <NUM> at a side close to the fourth wall <NUM>, the second arc-extinguishing chamber <NUM> includes a plurality of arc-extinguishing grids <NUM> sequentially arranged from a position close to the second stationary contact <NUM> toward the first wall <NUM>, and arranged substantially in an arc profile.

As illustrated by the figure, the first stationary contact <NUM> and the second stationary contact <NUM> are centrally symmetrical with respect to a rotation axis of the movable contact bracket <NUM>, the first arc-extinguishing chamber <NUM> and the second arc-extinguishing chamber <NUM> are centrally symmetrical with respect to the rotation axis of the movable contact bracket <NUM>, and the first movable contact <NUM> and the second movable contact <NUM> are radially in a straight line with respect to the rotation axis of the movable contact bracket <NUM>. Because the first stationary contact <NUM> and the second stationary contact <NUM> are identical in structure and working principle, and the first arc-extinguishing chamber <NUM> and the second arc-extinguishing chamber <NUM> are identical in structure and working principle, only the positions in the housing are different, therefore, only the first movable contact <NUM>, the first stationary contact <NUM> and the first arc-extinguishing chamber <NUM> and their related structures in the housing <NUM> will be described in detail below.

When the movable contact bracket <NUM> pivots so that the first movable contact <NUM> and the second movable contact <NUM> are separated from the first stationary contact <NUM> and the second stationary contact <NUM>, respectively, an arc will be generated between the movable contacts and the stationary contacts. <FIG> shows the moving direction of the arc, which moves towards the arc-extinguishing chamber and is divided into a plurality of short arcs by the arc-extinguishing grids of the arc-extinguishing chamber so as to extinguish the arc.

Because many parts of the switch are made of plastic and high-temperature gas will be generated under the action of electric arc, the isolating switch according to the present disclosure is provided with a plurality of exhaust ports on the housing <NUM>, so as to facilitate the generated gas to be discharged from the housing <NUM> and prevent the high-temperature gas from accumulating in the housing and damaging the parts in the switch.

As illustrated by the first embodiment of the isolating switch according to the present disclosure in <FIG>, the housing <NUM> of the isolating switch includes a first exhaust port <NUM>, a second exhaust port <NUM> and a third exhaust port <NUM> at a side of the first arc-extinguishing chamber <NUM>. Specifically, the first exhaust port <NUM> and the second exhaust port <NUM> are arranged on the first wall <NUM>, the first exhaust port <NUM> is closer to a position of the first stationary contact <NUM>, the second exhaust port <NUM> is arranged between the first exhaust port <NUM> and the third wall <NUM>, and the third exhaust port <NUM> is arranged on the second wall <NUM> and adjacent to an arc-extinguishing grid closest to the second wall <NUM> in the first arc-extinguishing chamber <NUM>, that is, adjacent to an arc-extinguishing grid at the extreme end of the first arc-extinguishing chamber <NUM>.

In order to guide the generated high-temperature gas from the vicinity of the first arc-extinguishing chamber <NUM> to three exhaust ports to be discharged from the housing <NUM>, a plurality of airway walls are also arranged in the housing <NUM> of the isolating switch according to the present disclosure. As illustrated by <FIG>, one end of a first airway wall <NUM> is adjacent to and aligned with a third arc-extinguishing grid of the first arc-extinguishing chamber <NUM> close to the first stationary contact <NUM>, and the other end of the first airway wall <NUM> is connected to a position between the first exhaust port <NUM> and the second exhaust port <NUM> on the first wall <NUM> of the housing <NUM>. Although not shown in the figure, it is conceivable that one end of the first airway wall <NUM> may be adjacent to and aligned with a fourth arc-extinguishing grid of the first arc-extinguishing chamber <NUM>, which is close to the first stationary contact <NUM>, according to the number and arrangement of arc-extinguishing grids in different situations. As a result, the high-temperature gas generated at the first few arc-extinguishing grids in the first arc-extinguishing chamber <NUM> is discharged from the first exhaust port <NUM> under the guidance of the first airway wall <NUM>, and the high-temperature gas generated at the arc-extinguishing grids in the middle part of the first arc-extinguishing chamber <NUM> is discharged from the second exhaust port <NUM>. Because the arc-extinguishing grids <NUM> of the first arc-extinguishing chamber <NUM> is arranged along an arc, the arc generated by the separation of the first movable contact <NUM> and the second movable contact <NUM> moves along the arc profile of the arc-extinguishing grids <NUM> towards the second wall <NUM>, and the high-temperature gas generated at the arc-extinguishing grid at the end of the first arc-extinguishing chamber <NUM> is discharged from the housing <NUM> through the third exhaust port <NUM> adjacent to the last arc-extinguishing grid.

According to the second embodiment of the isolating switch of the present disclosure, as illustrated by <FIG>, a second airway wall <NUM> can also be arranged in the housing <NUM> of the isolating switch. One end of the second airway wall <NUM> is arranged on the first wall <NUM> of the housing <NUM>, between the first exhaust port <NUM> and the second exhaust port <NUM>, and the other end of the second airway wall <NUM> extends towards the third exhaust port <NUM> and is connected to the third wall <NUM>. In addition, a depression <NUM> or a through hole is arranged on the second airway wall <NUM> at a position facing the second exhaust port <NUM>, so that the gas generated in the housing <NUM> can be exhausted from the second exhaust port <NUM>. As illustrated by <FIG>, one end of the third airway wall <NUM> is adjacent to the arc-extinguishing grid closest to the second wall <NUM> in the first arc-extinguishing chamber <NUM>, and the other end of the third airway wall <NUM> is connected to the second wall <NUM> adjacent to the third exhaust port <NUM>. Under the guidance of the second airway wall <NUM> and the third airway wall <NUM>, the high-temperature gas generated at the arc-extinguishing grids at the middle part and the end part of the first arc-extinguishing chamber <NUM> can be discharged from the housing <NUM> more effectively, thus preventing the parts in the housing <NUM> from being damaged by high temperature. Preferably, the first airway wall <NUM> and the second airway wall <NUM> are integrally connected between the first exhaust port <NUM> and the second exhaust port <NUM>, so that the first airway wall <NUM> and the second airway wall <NUM> cooperate to guide gas. In addition, it can be seen that the third exhaust port <NUM> in this embodiment is closer to the third wall <NUM>, for example, at the included angle between the second wall <NUM> and the third wall <NUM>, compared with the embodiment in which the third airway wall <NUM> is not provided in <FIG>.

Optionally, as illustrated by <FIG> and <FIG>, a fourth airway wall <NUM> can be further arranged in the housing <NUM> of the isolating switch, one end of the fourth airway wall <NUM> is arranged on the third wall <NUM>, adjacent to a position where the second airway wall <NUM> and the third wall <NUM> are connected, and the other end of the fourth airway wall <NUM> is connected with the first wall <NUM> and adjacent to the second exhaust port <NUM>. The fourth airway wall <NUM> can guide the gas passing through the depression <NUM> of the second airway wall <NUM> to the second exhaust port <NUM>, and prevent the high-temperature gas from gathering at the corner between the first wall <NUM> and the third wall <NUM>.

Preferably, the first airway wall <NUM>, the second airway wall <NUM>, the third airway wall <NUM> and the fourth airway wall <NUM>, and the joint of the first airway wall <NUM> and the second airway wall <NUM> all form a smooth curved contour, so as to avoid the edges and corners on the airway wall from obstructing gas discharge.

Instead of the embodiment that all arc-extinguishing grids in the same arc-extinguishing chamber are arranged along an arc, the arc-extinguishing grids in the same arc-extinguishing chamber can be divided into two parts, one of the two parts is arranged along an arc profile and the other one of the two parts is arranged along a straight line. For example, as illustrated by the embodiment in <FIG>, the plurality of arc-extinguishing grids <NUM> of the first arc-extinguishing chamber <NUM> are divided into a first part close to the first wall <NUM> and a second part close to the second wall <NUM>, the arc-extinguishing grids of the first part are arranged in an arc shape, and the arc-extinguishing grids of the second part are arranged along a straight line substantially perpendicular to the second wall <NUM>. Of course, the opposite example can also be envisaged, in which the arc-extinguishing grids of the first part close to the first wall <NUM> are arranged in a straight line, while the arc-extinguishing grids of the second part close to the second wall <NUM> are arranged in an arc profile.

Preferably, as illustrated by <FIG> and <FIG>, the arc-extinguishing grid closest to the first stationary contact <NUM> among the arc-extinguishing grids <NUM> in the first arc-extinguishing chamber <NUM> is in contact with the first stationary contact <NUM>, so as to enhance the guiding effect on the arc generated on the stationary contact. An included angle between the arc-extinguishing grid closest to the first stationary contact <NUM> and a contact surface of the first stationary contact <NUM> is preferably in the range of <NUM> to <NUM> degrees. In this way, the first arc-extinguishing grid closest to the first stationary contact <NUM> not only works as an arc-extinguishing grid, but also acts as an arc guide grid, and the material and structure of the first arc-extinguishing grid are consistent with those of other arc-extinguishing grids, so that it is not needed to manufacture the arc guide grid separately, and the production cost of the isolating switch is reduced.

Preferably, a connection plate can also be provided for the plurality of arc-extinguishing grids of the arc-extinguishing chamber. For example, as illustrated by the close-up of the arc-extinguishing chamber in <FIG>, a plurality of arc-extinguishing grids <NUM> are connected between upper and lower connection plates <NUM> and vertically fixed to the two connection plates <NUM>. The connection plate <NUM> preferably extends along an arrangement direction of the arc-extinguishing grids <NUM>. The configuration of the connection plate enables the plurality of arc-extinguishing grids <NUM> to form a module, thereby reducing the manufacturing cost and simplifying the assembly process. Two connection plates <NUM> are not necessary, and a configuration in which only the upper connection plate or only the lower connection plate exists is conceivable.

<FIG> shows a third embodiment of an isolating switch according to the present disclosure. As can be seen from the figure, a transition piece <NUM> is also inserted into the plurality of arc-extinguishing grids <NUM> in the first arc-extinguishing chamber <NUM>, and the transition piece <NUM> divides the plurality of arc-extinguishing grids <NUM> into a first group of arc-extinguishing grids close to the first wall <NUM> and a second group of arc-extinguishing grids close to the second wall <NUM>. The perspective view of the arc-extinguishing chamber in this embodiment is shown in <FIG>, and the structure of the transition piece <NUM> is shown in <FIG>. As can be seen from the figure, the transition piece <NUM> is generally in the shape of a triangular prism, including a flat first sidewall <NUM> and a flat second sidewall <NUM>, and an acute angle is formed between the first sidewall <NUM> and the second sidewall <NUM>. Each arc-extinguishing grid in the first group of arc-extinguishing grids at a side of the first side wall <NUM> is parallel to the first side wall <NUM>, and each arc-extinguishing grid in the second group of arc-extinguishing grids at a side of the second side wall <NUM> is parallel to the second side wall <NUM>. In other words, the first group of arc-extinguishing grids and the second group of arc-extinguishing grids are all arranged along a straight line. Particularly, as illustrated by <FIG>, a gap formed between the arc-extinguishing grids in the first group and the arc-extinguishing grids in the second group faces the rotation center of the movable contact bracket <NUM>. The transition piece <NUM> actually provides steering between two groups of arc-extinguishing grids arranged in a straight line, and steers the arc moving in a straight line along the arrangement direction of the first group of arc-extinguishing grids to the arrangement direction of the second group of arc-extinguishing grids, so that the arc is more effectively guided in the direction towards the third exhaust port <NUM>.

Preferably, for the embodiment of the transition piece <NUM> with a roughly triangular cross section, a first partition wall <NUM> and a second partition wall <NUM> are also arranged in the housing <NUM> of the isolating switch. One end of the first partition wall <NUM> is adjacent to and approximately flush with a first side wall <NUM> of the transition piece <NUM>, and the other end of the first partition wall <NUM> is connected to the third wall <NUM>, and the first partition wall <NUM> forms a smooth curve profile toward the second exhaust port <NUM>. One end of the second partition wall <NUM> is adjacent to and approximately flush with a second sidewall <NUM> of the transition piece <NUM>, and the other end of the second partition wall <NUM> is connected to the third wall <NUM>, and the second partition wall <NUM> forms a smooth curve profile in the direction of the third exhaust port <NUM>. In this way, the high-temperature gas generated close to the first group of arc-extinguishing grids is discharged to the second exhaust port <NUM> under the guidance of the first airway wall <NUM> and the first partition wall <NUM>, and the high-temperature gas generated close to the second group of arc-extinguishing grids is discharged to the third exhaust port <NUM> under the guidance of the second partition wall <NUM> and the third airway wall <NUM>. It should be noted that when the first partition wall <NUM> and the second partition wall <NUM> are provided, the gas generated close to the first group of arc-extinguishing grids does not need to be guided to the third exhaust port <NUM>, so there is no need to provide a second airway wall to prevent the high-temperature gas moving to the second exhaust port <NUM> from being blocked.

Preferably, in addition to the first group and the second group of arc-extinguishing grids, two arc-extinguishing grids 80a, 80b can be arranged close to the first stationary contact <NUM>. As illustrated by <FIG>, the first arc-extinguishing grid 80a of the first arc-extinguishing chamber <NUM> is in contact with the stationary contact <NUM>, and forms an angle between <NUM> and <NUM> degrees with the contact surface of the stationary contact <NUM>. The second arc-extinguishing grid 80b is parallel to the first arc-extinguishing grid 80a, but slightly offsets towards the first wall <NUM>. The third arc-extinguishing grid 80c is the first arc-extinguishing grid of the first group of arc-extinguishing grids, is parallel to the second arc-extinguishing grid 80b, but slightly offsets with respect to the second arc-extinguishing grid 80b towards the first wall <NUM>. The arc-extinguishing grids which are offset provide an enhanced arc guiding effect for the arc generated on the stationary contact, so that the arc is guided into the arc-extinguishing chamber and moves along the arrangement direction of the arc-extinguishing grids.

Similar to the first embodiment and the second embodiment, in the third embodiment of the isolating switch according to the present disclosure, at least one connection plate can be provided for the first group of arc-extinguishing grids and the second group of arc-extinguishing grids respectively, so that the plurality of arc-extinguishing grids <NUM> form a module. Because the arc-extinguishing grids in each group of the present embodiment are arranged in a straight line, the manufacturing cost is further reduced and the assembly process is simplified.

As mentioned above, in different configurations, the second arc-extinguishing chamber <NUM> always keeps central symmetry with the first arc-extinguishing chamber <NUM> about the rotation axis of the movable contact bracket <NUM>, so the description about the structure of the first arc-extinguishing chamber <NUM> can also be applied to the second arc-extinguishing chamber <NUM>. In addition, for the second movable contact <NUM>, the second stationary contact <NUM> and the second arc-extinguishing chamber <NUM>, a fourth exhaust port <NUM>', a fifth exhaust port <NUM>' and a sixth exhaust port <NUM>' are correspondingly provided. The fourth exhaust port <NUM>' and the fifth exhaust port <NUM>' are arranged on the second wall <NUM>, the fourth exhaust port <NUM>' is closer to the second stationary contact <NUM> than the fifth exhaust port <NUM>', and the fifth exhaust port <NUM>' is arranged between the fourth exhaust port <NUM>' and the fourth wall <NUM>. The sixth exhaust port <NUM>' is arranged on the first wall <NUM> and adjacent to the arc-extinguishing grid closest to the first wall <NUM> in the second arc-extinguishing chamber <NUM>. The position of the first exhaust port <NUM> and the position of the fourth exhaust port <NUM>' are centrally symmetrical with respect to the rotation axis of the movable contact bracket <NUM>, the position of the second exhaust port <NUM> and the position of the fifth exhaust port <NUM>' are centrally symmetrical with respect to the rotation axis of the movable contact bracket <NUM>, and the position of the third exhaust port <NUM> and the position of the sixth exhaust port <NUM>' are centrally symmetrical with respect to the rotation axis of the movable contact bracket <NUM>.

Correspondingly, a fifth airway wall <NUM>', a sixth airway wall <NUM>', a seventh airway wall <NUM>' and an eighth airway wall <NUM>' are also arranged in the housing <NUM> of the isolating switch. The fifth airway wall <NUM>' and the first airway wall <NUM> are centrally symmetrical with respect to the rotation axis of the movable contact bracket <NUM>, the sixth airway wall <NUM>' and the second airway wall <NUM> are centrally symmetrical with respect to the rotation axis of the movable contact bracket <NUM>, the seventh airway wall <NUM>' and the third airway wall <NUM> are centrally symmetrical with respect to the rotation axis of the movable contact bracket <NUM>, and the eighth airway wall <NUM>' and the fourth airway wall <NUM> are centrally symmetrical with respect to the movable contact bracket <NUM>. In addition, for the embodiment provided with the transition piece <NUM>, a third partition wall <NUM>' and a fourth partition wall <NUM>' are also provided in the housing <NUM>, and the third partition wall <NUM>' and the first partition wall <NUM> are centrally symmetrical with respect to the rotation axis of the movable contact bracket <NUM>, and the fourth partition wall <NUM>' and the second partition wall <NUM> are centrally symmetrical with respect to the rotation axis of the movable contact bracket <NUM>.

Claim 1:
An isolating switch, wherein the isolating switch comprises:
a housing (<NUM>) comprising a first wall (<NUM>), a second wall (<NUM>), a third wall (<NUM>) and a fourth wall (<NUM>), the first wall (<NUM>) and the second wall (<NUM>) being arranged opposite to each other, the third wall (<NUM>) and the fourth wall (<NUM>) being arranged opposite to each other and connecting the first wall (<NUM>) to the second wall (<NUM>) respectively;
a movable contact assembly comprising a movable contact bracket (<NUM>) and a first movable contact (<NUM>) arranged on the movable contact bracket (<NUM>), the movable contact bracket (<NUM>) being pivotally arranged in the housing (<NUM>), the first movable contact (<NUM>) being able to pivot together with the movable contact bracket (<NUM>);
a first stationary contact (<NUM>) fixedly arranged in the housing (<NUM>) at a side close to the first wall (<NUM>) and being able to contact and separate from the first movable contact (<NUM>);
a first arc-extinguishing chamber (<NUM>) arranged in the housing (<NUM>) at a side close to the third wall (<NUM>) and comprising a plurality of arc-extinguishing grids (<NUM>), which are sequentially arranged from a position close to the first stationary contact (<NUM>) toward a side of the second wall (<NUM>); characterized in that the housing (<NUM>) is provided with a first exhaust port (<NUM>), a second exhaust port (<NUM>) and a third exhaust port (<NUM>), the first exhaust port (<NUM>) and the second exhaust port (<NUM>) are arranged on the first wall (<NUM>), the first exhaust port (<NUM>) is closer to the first stationary contact (<NUM>) than the second exhaust port (<NUM>), the second exhaust port (<NUM>) is arranged between the first exhaust port (<NUM>) and the third wall (<NUM>), and the third exhaust port (<NUM>) is arranged on the second wall (<NUM>) and adjacent to one of the plurality of the arc-extinguishing grids (<NUM>) closest to the second wall (<NUM>) in the first arc-extinguishing chamber (<NUM>).