CN220796568U - Arc extinguishing device, switch unit and isolating switch - Google Patents

Abstract

The application provides an arc extinguishing device, a switch unit and an isolating switch, and relates to the technical field of piezoelectric devices. The arc extinguishing device comprises a gas generating piece and a magnet group arranged in the gas generating piece, wherein the magnet group comprises at least two magnets symmetrically arranged along a first direction, magnetizing directions of a plurality of magnets are the same, and at least two magnets have a first included angle; the magnet comprises an N pole and an S pole, the N pole and the S pole are distributed on two opposite sides of the magnet along a first direction, and the magnetizing direction of the magnet is perpendicular to the moving plane of the moving contact of the switch unit. The arc extinguishing device obtained through the design can enable the arc extinguishing process to be more sufficient by perpendicularly arranging the magnetizing direction of the magnet and the moving plane of the moving contact of the switch unit, so that the effective utilization rate of the magnet is improved.

Description

Arc extinguishing device, switch unit and isolating switch

Technical Field

The application relates to the technical field of piezoelectric devices, in particular to an arc extinguishing device, a switch unit and an isolating switch.

Background

The isolating switch is a switching device which is mainly used for isolating a power supply, switching operation and switching on and off a small current circuit and has no arc extinguishing function. When the isolating switch is switched off, the internal moving contact and the fixed contact are rapidly disconnected, at the moment, the voltage between the moving contact and the fixed contact causes air medium discharge to generate high-temperature electric arc, and the electric arc causes the air temperature in the arc extinguishing device to rapidly rise in the combustion process so as to accelerate air ionization. Because of the relatively large arc energy, if left on the moving contact for a long period of time, the contact is severely ablated. In view of this, arc extinguishing devices are often provided in each switching apparatus such as a circuit breaker, a contactor, a disconnector, an automatic transfer switch, etc., in order to desirably extinguish an arc rapidly and to ensure operation safety of the electrical apparatus.

The current isolator explosion chamber adopts the mode that the N utmost point of two magnets is relative to each other to arrange from top to bottom more, and N utmost point setting direction is parallel with the contact motion plane, has led to the magnetization direction of magnet to be parallel with the contact motion plane, has reduced the effective rate of utilization of magnet. Therefore, there is a need for an arc extinguishing device capable of increasing the effective use rate of magnets to solve the above-mentioned problems.

Disclosure of Invention

The application provides an arc extinguishing device, a switch unit and an isolating switch, and aims to solve the problem that the effective utilization rate of a magnet of the arc extinguishing device is not high in the prior art.

Embodiments of the present application are implemented as follows:

in one aspect of the embodiments of the present application, an arc extinguishing device is provided, including a gas generating member and a magnet group disposed in the gas generating member, where the magnet group includes at least two magnets symmetrically disposed along a first direction, and magnetizing directions of the plurality of magnets are all consistent, and the at least two magnets have a first included angle; the magnet comprises an N pole and an S pole, the N pole and the S pole are distributed on two opposite sides of the magnet along a first direction, and the magnetizing direction of the magnet is perpendicular to the moving plane of the moving contact of the switch unit.

Optionally, a heat insulation member is attached to one side of the magnet, which is close to the moving contact or the fixed contact of the switch unit, for insulating the magnet.

Optionally, a magnet increasing sheet is arranged on one side of the magnet, which is far away from the moving contact or the fixed contact of the switch unit.

Optionally, the first included angle is a right angle or an obtuse angle.

Optionally, the gas generating member includes a housing and a receiving space disposed in the housing, and the magnet assembly is disposed in the receiving space; the opposite sides of the shell respectively comprise gas generating grooves which are arranged in opposite directions.

Optionally, the gas generating groove is provided with a connecting part and an extending part, one end of the connecting part is fixedly connected with the shell, the other end of the connecting part is fixedly connected with the extending part, and a second included angle is formed between the extending part and the connecting part.

Optionally, the second included angle is an obtuse angle.

Optionally, a containing cavity is formed between the connecting part and the extending part, and a plurality of ribs which are arranged in parallel and extend along the first direction are arranged in the containing cavity.

Optionally, a plurality of heat dissipation holes are respectively arranged on two opposite sides of the shell.

In another aspect of the present application, a switch unit is provided, including two of the arc extinguishing devices, a fixed contact, and a moving contact capable of contacting with or separating from the fixed contact; the two arc extinguishing devices are respectively arranged on two opposite sides of the separation and combination path of the moving contact and the fixed contact, and are used for extinguishing an arc generated when the moving contact and the fixed contact are separated.

In another aspect of the present application, there is further provided an isolating switch, including the above-mentioned switch unit, an operating mechanism, and an operating handle; the switch units are arranged in a stacked mode and are sequentially connected, one side of the operating mechanism is connected with the operating handle, the other side of the operating mechanism is connected with at least two sequentially connected switch units, and the operating handle is used for switching the at least two sequentially connected switch units between a switching-off state and a switching-on state through controlling the operating mechanism.

The beneficial effects of the embodiment of the application include: the arc extinguishing device comprises the gas generating part and the magnet group arranged in the gas generating part, wherein the gas generating part can rapidly blow an electric arc generated when the moving contact is separated from the fixed contact to the arc extinguishing chamber, so that the speed of the electric arc moving to the inside of the arc extinguishing device is accelerated, and the high efficiency of the arc extinguishing process is improved; the magnet group comprises at least two magnets symmetrically arranged along a first direction, magnetizing directions of the plurality of magnets are consistent, the at least two magnets have a first included angle, and the magnetic force of the magnet group can be effectively enhanced by arranging the at least two magnets to have a certain included angle, so that the magnetic driving force to an electric arc is improved, and the electric arc is extinguished finally; the magnet comprises an N pole and an S pole, the N pole and the S pole are distributed on two opposite sides of the magnet along the first direction, and the magnetizing direction of the magnet is perpendicular to the moving plane of the moving contact of the isolating switch, so that the moving plane of the moving contact is contacted with the magnetizing direction of the magnetic field to the greatest extent, the arc extinguishing process is more complete, and the effective utilization rate of the magnet is improved. The arc extinguishing device obtained through the design can enable the arc extinguishing process to be more sufficient by perpendicularly arranging the magnetizing direction of the magnet and the moving plane of the moving contact of the switch unit, so that the effective utilization rate of the magnet is improved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered limiting the scope, and that other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic structural diagram of an arc extinguishing device according to an embodiment of the present application;

fig. 2 is a second schematic structural diagram of an arc extinguishing device according to an embodiment of the present disclosure;

fig. 3 is a schematic structural diagram of a switch unit according to an embodiment of the present application;

fig. 4 is a schematic structural diagram of an isolating switch according to an embodiment of the present application.

Icon: 100-arc extinguishing device; 110-gas generating piece; 111-a housing; 112-accommodating space; 113-a gas generating tank; 1131-a connection; 1132-extension; 114-ribs; 115-heat dissipation holes; 120-magnet assembly; 121-a magnet; 1211-N poles; 1212-S pole; a-a first direction; 130-insulation; 140-adding a magnet sheet; 200-a switching unit; 210-a moving contact; 220-fixed contact; 300-isolating switch; 310-an operating mechanism; 320-operating the handle.

Detailed Description

For the purposes of making the objects, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions of the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application, and it is apparent that the described embodiments are some, but not all, embodiments of the present application. The components of the embodiments of the present application, which are generally described and illustrated in the figures herein, may be arranged and designed in a wide variety of different configurations.

In the description of the present application, it should be understood that terms indicating orientation or positional relationship are based on the orientation or positional relationship shown in the drawings, and are merely for convenience in describing the present utility model and simplifying the description, rather than indicating or implying that the apparatus or elements being referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the present utility model.

It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further definition or explanation thereof is necessary in the following figures.

In this application, unless specifically stated and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the present utility model can be understood by those of ordinary skill in the art according to the specific circumstances.

Referring to fig. 1 and 2, in one aspect of the embodiments of the present application, an arc extinguishing device 100 is provided, which includes a gas generating member 110 and a magnet assembly 120 disposed in the gas generating member 110; the magnet set 120 comprises at least two magnets 121 symmetrically arranged along a first direction a, wherein magnetizing directions of the plurality of magnets 121 are consistent, and the at least two magnets 121 have a first included angle; the magnet 121 includes an N pole 1211 and an S pole 1212, the N pole 1211 and the S pole 1212 are distributed on opposite sides of the magnet 121 along the first direction a, and the magnetizing direction of the magnet 121 is perpendicular to the moving plane of the moving contact 210 of the switch unit 200.

Specifically, the present application provides an arc extinguishing device 100. The arc-shaped gas generating device is provided with a gas generating piece 110 capable of generating gas to drive an arc to move, and symmetrically arranged magnet groups 120 are arranged in the gas generating piece 110.

Each magnet assembly 120 comprises at least two magnets 121, and in a preferred embodiment of the present application, the magnet assemblies 120 comprise two magnets 121 arranged in parallel, as shown in fig. 1; the two magnets 121 are symmetrically disposed along a first direction a, which is a width direction of the gas generating member 110. The two magnets 121 are arranged side by side and have a first included angle, which in a preferred embodiment of the present application is a right angle or an obtuse angle.

The magnet 121 includes an N pole 1211 and an S pole 1212, and the N pole 1211 is disposed in a direction perpendicular to a movement plane of the moving contact 210 of the switch unit 200, i.e., a magnetizing direction of the magnet 121 is perpendicular to the movement plane of the moving contact 210.

It should be noted that, first, in the embodiment of the present application, at least two magnets 121 are arranged in parallel, and a first included angle exists, and the first included angle is a right angle or an obtuse angle. The arrangement can increase the magnetic field between the at least two magnets 121 as much as possible, and compared with the arrangement of two magnets in parallel, the arrangement of a certain angle between the at least two magnets 121 can improve the magnetic driving force to the arc and finally extinguish the arc, so that the arc extinguishing process is more efficient.

In addition, it should be noted that, in one embodiment of the present application, as shown in fig. 1, the magnet set includes two permanent magnets arranged in parallel and symmetrically; of course, in other embodiments of the present application, the magnet set may also include three, four or more permanent magnets arranged along the opening and closing paths of the fixed contact and the moving contact of the switch unit, where the number of specific settings of the magnets is not limited in this application, so long as the magnetizing directions of the permanent magnets can be guaranteed to be consistent.

Second, in a preferred embodiment of the present application, as shown in fig. 1, the magnets 121 are each N-pole 1211 facing the moving contact 210, and s-pole 1212 facing a side facing away from the moving contact 210; of course, the S pole 1212 may be disposed toward the movable contact 210, and the n pole 1211 may be disposed toward a side away from the movable contact 210. The present application does not limit the magnetizing direction of the magnet 121 and the moving plane of the moving contact 210 as long as it can be satisfied that the magnetizing direction is perpendicular to each other so as to improve the effective utilization rate of the magnet 121.

In one embodiment of the present application, as shown in fig. 1 and 3, the magnetizing direction of the magnet is that the N pole faces the moving contact or the fixed contact, and the S pole faces away from the moving contact or the fixed contact, so as to form a structure that the N pole faces inwards and the S pole faces outwards; of course, the magnets may be provided with the N pole facing outward and the S pole facing inward, as long as the magnetization direction is uniform.

Third, in the embodiment of the present application, since the magnets 121 are arranged in parallel inside the gas generating member 110, the volume of the magnets 121 used in the present application is also smaller than that of the prior art. Such an arrangement enables a small volume of the arc extinguishing device 100, more facilitates the installation of the arc extinguishing device 100, and reduces the production cost.

The arc extinguishing device 100 provided by the embodiment of the application comprises the gas generating piece 110 and the magnet group 120 arranged in the gas generating piece 110, wherein the gas generating piece 110 can quickly blow an arc generated when the movable contact 210 is separated from the fixed contact 220 to the arc extinguishing chamber, so that the speed of the arc moving to the inside of the arc extinguishing device 100 is accelerated, and the high efficiency of the arc extinguishing process is improved; the magnet set 120 comprises at least two magnets 121 symmetrically arranged along the first direction a, magnetizing directions of the plurality of magnets 121 are consistent, the at least two magnets 121 have a first included angle, and the magnetic force of the magnet set 120 can be effectively enhanced by arranging the at least two magnets 121 to have a certain included angle, so that the magnetic driving force to an electric arc is improved, and the electric arc is extinguished finally; the magnet 121 includes an N pole 1211 and an S pole 1212, the N pole 1211 and the S pole 1212 are distributed on opposite sides of the magnet 121 along the first direction a, and the magnetizing direction of the magnetic field is perpendicular to the moving plane of the moving contact 210 of the switch unit 200, so that the moving plane of the moving contact 210 is contacted with the magnetizing direction of the magnetic field to the greatest extent, thereby enabling the arc extinguishing process to be more sufficient and improving the effective utilization rate of the magnet 121. The arc extinguishing device 100 designed in the above manner can make the arc extinguishing process more complete by setting the magnetizing direction of the magnet 121 perpendicular to the movement plane of the moving contact 210 of the switch unit 200, so as to improve the effective utilization rate of the magnet 121.

In one embodiment of the present application, as shown in fig. 1, a heat insulator 130 is attached to a side of the magnet 121 near the moving contact 210 or the fixed contact 220 of the switch unit 200, for insulating the magnet 121.

Specifically, in a preferred embodiment of the present application, as shown in fig. 1, one side of the magnet 121, which is close to the moving contact 210 or the fixed contact 220 of the switch unit 200, is an N pole 1211. A heat insulating member 130 is attached to the N pole 1211 direction of the magnet 121, and the heat insulating member 130 can insulate the magnet 121 to prevent the magnet 121 from demagnetizing due to high temperature; similarly, if the magnet 121 is such that the S-pole 1212 faces the movable contact 210 or the fixed contact 220, the position of the heat insulator 130 may not be changed, and the heat insulator 130 may be attached to the magnet 121 in the S-pole 1212 direction, so long as the heat insulator 130 can attach to the magnet 121 to insulate heat and prevent demagnetization. By providing the heat insulator 130, the magnet 121 can be prevented from being demagnetized due to high temperature, and the reliability of the arc extinguishing device 100 can be improved.

In one embodiment of the present application, as shown in fig. 1, a magnet increasing sheet 140 is disposed on a side of the magnet 121 away from the moving contact 210 or the fixed contact 220 of the switch unit 200.

Specifically, in a preferred embodiment of the present application, as shown in fig. 1, one side of the magnet 121 away from the moving contact 210 or the fixed contact 220 of the switch unit 200 is the S pole 1212 away from the moving contact 210 or the fixed contact 220. A magnet increasing sheet 140 is attached to the S pole 1212 direction of the magnet 121, and the magnet increasing sheet 140 can effectively increase the magnetic field in the arc region. Similarly, if the magnet 121 is the S-pole 1212 facing the moving contact 210 or the fixed contact 220, the position of the magnet increasing piece 140 may not be changed, and the magnet increasing piece 140 may be attached to the N-pole 1211 of the magnet 121, so long as the magnet increasing piece 140 can be attached to the magnet 121 to exert the effect of increasing the magnetic field. By providing the additional magnet pieces 140, the reliability of the arc extinguishing device 100 can be improved, and the efficiency of the arc extinguishing process can be improved.

As shown in fig. 2, the gas generating member 110 includes a housing 111 and a receiving space 112 disposed in the housing 111, and the magnet assembly 120 is disposed in the receiving space 112; the opposite sides of the housing 111 include gas generating grooves 113 disposed opposite to each other, respectively.

Specifically, the gas generating member 110 includes a housing 111. In a preferred embodiment of the present application, the housing 111 includes an upper half and a lower half that are connected, and the housing 111 of the upper half and the housing 111 of the lower half together form a receiving space 112 for placing the magnet group 120; of course, the housing 111 may be provided in a left-right two part or in a unitary structure, etc., and the specific form of the housing 111 is not limited in this application.

The opposite sides of the housing 111 include two gas generating grooves 113 disposed opposite to each other, and the two gas generating grooves 113 are disposed on the same side of the gas generating member 110 and disposed opposite to each other.

By arranging the gas generating grooves 113 in opposite directions, the arc blowing passage of the gas generating member 110 can be defined, thereby improving the efficiency of the arc extinguishing process.

Further, as shown in fig. 1, the gas generating tank 113 has a connecting portion 1131 and an extending portion 1132 that are connected to each other, one end of the connecting portion 1131 is fixedly connected to the housing 111, the other end is fixedly connected to the extending portion 1132, a second included angle is formed between the extending portion 1132 and the connecting portion 1131, and the second included angle is an obtuse angle, so that the gas generating tank 113 has a certain inclination angle.

Through the setting of the second included angle, the gas generating groove 113 has a certain inclination angle, so that an arc blowing channel of the gas generating piece 110 can be further defined, and meanwhile, the arc stretching effect can be achieved, so that the high efficiency of an arc extinguishing process is improved.

In one implementation manner of the embodiment of the present application, as shown in fig. 1 and fig. 2, a receiving cavity is formed between the connection portion 1131 and the extension portion 1132, and a plurality of ribs 114 extending along the first direction a and arranged in parallel are disposed in the receiving cavity.

Specifically, a receiving cavity is formed between the connecting portion 1131 and the extending portion 1132, and a plurality of ribs 114 are disposed in the receiving cavity, and the ribs 114 extend along the first direction a and are uniformly arranged in the receiving cavity. By arranging the ribs 114, the electric arc can be lengthened, the electric arc voltage is increased, and the electric arc extinguishing process is more efficient and reliable.

In one possible implementation of the embodiment of the present application, the opposite sides of the housing 111 are provided with a plurality of heat dissipation holes 115, respectively.

Specifically, a plurality of heat dissipation holes 115 are uniformly distributed on the housing 111, and the heat dissipation holes 115 are uniformly distributed on two opposite sides of the housing 111. By providing the heat radiation holes 115, the arc extinguishing device 100 can be better radiated, and the magnet 121 is prevented from being demagnetized due to an excessively high temperature, so that the reliability of the arc extinguishing device 100 is improved, and the arc extinguishing device 100 is safer.

In another embodiment of the present application, a switch unit 200 is provided, which includes two of the arc extinguishing devices 100, a fixed contact 220, and a movable contact 210 contacting or separating from the fixed contact 220; the two arc extinguishing devices 100 are respectively arranged at two opposite sides of the moving contact 210 and the fixed contact 220 on the separating and combining paths, and the arc extinguishing devices 100 are used for extinguishing an arc generated when the moving contact 210 and the fixed contact 220 are separated.

Specifically, as shown in fig. 3, the present application further provides a switch unit 200. The switch unit 200 includes a moving contact 210, a fixed contact 220, and two arc extinguishing devices 100 respectively disposed on two opposite sides of the moving contact 210 and the fixed contact 220 on the opening and closing paths. When the switching unit 200 is opened, the moving contact 210 rotates around its center portion and is separated from the fixed contact 220. When the moving contact 210 is separated from the fixed contact 220, an arc is generated, and the arc extinguishing device 100 positioned at two opposite ends of the separating and combining path of the moving contact 210 and the fixed contact 220 can effectively extinguish the arc, so as to ensure the operation safety of the electrical equipment. The plane in which the moving direction of the moving contact 210 is perpendicular to the magnetizing direction of the arc extinguishing device 100, so that the high efficiency and reliability of arc extinguishing of the switch unit 200 can be further improved, and meanwhile, the safety of the use process of the electrical equipment is improved. The specific structure and the beneficial effects of the arc extinguishing device 100 are described in detail above, and are not repeated here.

In another possible embodiment of the present application, there is also provided an isolating switch 300, as shown in fig. 4, including the above-mentioned switch unit 200, operating mechanism 310 and operating handle 320; the plurality of switch units 200 are stacked and connected in sequence, one side of the operating mechanism 310 is connected with the operating handle 320, the other side is connected with at least two switch units 200 connected in sequence, and the operating handle 320 switches the at least two switch units 200 connected in sequence between a switching-off state and a switching-on state by controlling the operating mechanism 310. Specifically, the isolating switch 300 is provided with at least two sequentially connected switch units 200 and an operating mechanism 310, and the switching of the opening and closing states of the at least two sequentially connected switch units 200 can be simultaneously controlled through the operating mechanism 310, so that the operation is simpler and more convenient, and the resource utilization rate is greatly improved; the isolating switch 300 can effectively extinguish the arc when the switch is opened, so as to ensure the operation safety of the electrical equipment. Because the plane in which the moving direction of the moving contact 210 in the isolating switch 300 is located is perpendicular to the magnetizing direction in the arc extinguishing device 100, the high efficiency and reliability of arc extinguishing of the isolating switch 300 can be further improved, and meanwhile, the safety of the use process of the electrical equipment is improved.

The foregoing is merely exemplary embodiments of the present application and is not intended to limit the scope of the present application, and various modifications and variations may be suggested to one skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims (10)

1. The arc extinguishing device is characterized by comprising a gas generating piece (110) and a magnet group (120) arranged in the gas generating piece (110), wherein the magnet group (120) comprises at least two magnets (121) symmetrically arranged along a first direction, magnetizing directions of a plurality of magnets (121) are the same, and at least two magnets (121) have a first included angle; the magnet (121) comprises an N pole (1211) and an S pole (1212), the N pole (1211) and the S pole (1212) are distributed on two opposite sides of the magnet (121) along the first direction, and the magnetizing direction of the magnet (121) is perpendicular to the moving plane of the moving contact (210) of the switch unit (200).

2. The arc extinguishing device according to claim 1, wherein a heat insulator (130) is attached to a side of the magnet (121) close to the moving contact (210) or the fixed contact (220) of the switch unit (200) for insulating the magnet (121).

3. The arc extinguishing device according to claim 1, characterized in that a side of the magnet (121) remote from the moving contact (210) or the stationary contact (220) of the switching unit (200) is provided with a magnet increasing sheet (140).

4. The arc suppressing apparatus according to claim 1, wherein the first included angle is a right angle or an obtuse angle.

5. The arc extinguishing device according to claim 1, characterized in that the gas generating member (110) comprises a housing (111) and a receiving space (112) provided in the housing (111), the magnet assembly (120) being placed in the receiving space (112); the two opposite sides of the shell (111) respectively comprise gas generating grooves (113) which are arranged in opposite directions.

6. The arc extinguishing device according to claim 5, characterized in that the gas generating tank (113) has a connecting portion (1131) and an extending portion (1132), one end of the connecting portion (1131) is fixedly connected with the housing (111), the other end is fixedly connected with the extending portion (1132), a second included angle is formed between the extending portion (1132) and the connecting portion (1131), and the second included angle is an obtuse angle.

7. The arc extinguishing device according to claim 6, wherein a receiving cavity is formed between the connecting portion (1131) and the extending portion (1132), and a plurality of ribs (114) extending in the first direction and arranged in parallel are provided in the receiving cavity.

8. The arc extinguishing device according to claim 5, characterized in that the opposite sides of the housing (111) are respectively provided with a plurality of heat dissipation holes (115).

9. A switching unit, characterized in that it comprises an arc extinguishing device (100) according to any of the claims 1-8, a stationary contact (220) and a moving contact (210) capable of being in contact with or separated from said stationary contact (220); the two arc extinguishing devices (100) are respectively arranged on two opposite sides of the separation and combination path of the moving contact (210) and the fixed contact (220), and the switch unit (200) is used for extinguishing an arc generated when the moving contact (210) and the fixed contact (220) are separated.

10. A disconnector, characterized by comprising a switching unit (200) according to claim 9, an operating mechanism (310) and an operating handle (320); the switch units (200) are arranged in a stacked mode and are sequentially connected, one side of the operating mechanism (310) is connected with the operating handle (320), the other side of the operating mechanism is connected with at least two sequentially connected switch units (200), and the operating handle (320) is used for switching between a switching-off state and a switching-on state of the at least two sequentially connected switch units (200) through controlling the operating mechanism (310).