Patent Application
20120169441
The present invention relates to an electromagnet device which displaces a movable core with respect to a fixed core by energization to an electromagnetic coil and relates to a switch device which opens and closes contacts by the driving force of the electromagnet device, the switch device being used for electric power transmission/distribution and reception facilities.
In some switch devices which open and close contacts by the driving force of an electromagnet device, the electromagnet device and main circuit contact sections of the switch device are coaxially arranged and a merit which can reduce transfer loss due to a connection mechanism is provided. In the thus configured switch device, the main circuit contact sections of the switch device, an insulating rod, a driving rod, a contact pressure spring which applies a contact pressure to main circuit contacts, an open spring which generates a load of an opening direction at a movable contact of the main circuit contacts, and a movable shaft of the electromagnet device are all coaxially arranged. (For example, see Patent Document 1.)
Patent Document 1: Japanese Examined Patent Publication No. 4277198
In the switch device in which the electromagnet device and the main circuit contact sections of the switch device are coaxially arranged, a problem exists in that the main circuit contact sections of the switch device, the insulating rod, the driving rod, the contact pressure spring, the open spring, and an electromagnet are all coaxially arranged; and therefore, the axial dimension of the switch device becomes large.
The present invention has been made to solve the aforementioned problem, and an object of the present invention is to obtain an electromagnet device capable of shortening the axial dimension of a switch device and a switch device using the electromagnet device.
Main circuit contact sections of a switch device, an insulating rod, a driving rod, a contact pressure spring, an open spring, and a part of an electromagnet are arranged in the same axial range. More particularly, the open spring and the electromagnet are arranged in the same axial region.
The whole length of summation of the electromagnet and the open spring can be shortened and reduction in size of the switch device can be achieved.
The movable contact 3 comes into contact with or separates from the fixed contact 2 by displacement in an axis line direction (hereinafter, merely referred to as “axis line direction”) of the switch device 1. Contacts of the switch device 1 are closed by the fact that movable contact 3 comes into contact with the fixed contact 2, and the contacts are opened by the fact that movable contact 3 separates from the fixed contact 2.
The inside of the vacuum valve 4 is kept under vacuum in order to improve arc suppression performance between the fixed contact 2 and the movable contact 3. The movable contact 3 comes into contact with or separates from the fixed contact 2 in the vacuum valve 4. When the movable contact 3 is separated from the fixed contact 2, the inside of the vacuum valve 4 is kept under vacuum and accordingly the inside becomes negative pressure; and thus, a force in which the movable contact 3 tries to close to the fixed contact 2 is exerted.
The electromagnet device 5 is supported by a plate-like support member 7. Furthermore, the electromagnet device 5 has a driving shaft 8 connected to the movable contact 3 via the connection device 6, an open spring (biasing body) 9 which biases the driving shaft 8 to a direction in which the movable contact 3 separates from the fixed contact 2, and an electromagnet 10 which displaces the driving shaft 8 to a direction in which the movable contact 3 comes into contact with the fixed contact 2 against a load of the open spring 9.
The driving shaft 8 passes through the support member 7 so as to be capable of displacing in the axis line direction. Furthermore, the driving shaft 8 is made of a material with low permeability (low magnetic material), such as stainless material. The electromagnet 10 is provided with a fixed core 19 and a movable core 20 to which the driving shaft 8 is fixed, the movable core 20 being capable of displacing in the axis line direction with respect to the fixed core 19.
The open spring 9 is compressed between the movable core 20 and the support plate 7 to generate an elastic repulsive force in the axis line direction. Therefore, the driving shaft 8 is biased to a direction in which the movable contact 3 separates from the fixed contact 2 by the elastic repulsive force of the open spring 9, the elastic repulsive force being to be exerted on the movable core 20.
The electromagnet 10 is mounted on the support member 7. The driving shaft 8 is selectively displaced by the fact that the electromagnet 10 is controlled in either direction in which the movable contact 3 comes into contact with the fixed contact 2 (contact closing direction) or direction in which the movable contact 3 separates from the fixed contact 2 (opening direction).
The connection device 6 has a movable rod 13 which is located in the axis line direction and fixed to the movable contact 3, an insulating rod 14 placed in an intermediate portion of the movable rod 13, and a contact pressure device 15 placed between the movable rod 13 and the driving shaft 8. The movable rod 13 is separated and fixed to both end sections of the insulating rod 14 placed in the intermediate portion; and accordingly, the movable rod 13 is electrically insulated. Therefore, the electromagnet device 5 is insulated by the insulating rod 14 with respect to the movable contact 3.
The contact pressure device 15 has a spring frame 16 fixed to the movable rod 13, a latch plate 17 which is fixed to an end section of the driving shaft 8 and located in the spring frame 16, and a contact pressure spring 18 shrunk and connected between the spring frame 16 and the latch plate 17.
The driving shaft 8 is capable of displacing in the axis line direction with respect to the spring frame 16 together with the latch plate 17. The contact pressure spring 18 biases the driving shaft 8 to a direction to be separated from the movable rod 13. Displacement of the driving shaft 8 to the direction to be separated from the movable rod 13 is regulated by engagement of the latch plate 17 with respect to the spring frame 16.
The movable core 20 is capable of displacing between a backward movement position separated from the fixed core 19 (
In the case where the movable contact 3 is separated from the fixed contact 2 (
When a contact closing operation is performed from a state where the movable contact 3 is separated from the fixed contact 2, the driving shaft 8 is displaced to the contact closing direction together with the connection device 6 and the movable contact 3 as the open spring 9 is shrunk. After that, when the movable contact 3 comes into contact with the fixed contact 2, the displacement of the connection device 6 and the movable contact 3 is stopped. Also, after that, the driving shaft 8 is further displaced to the contact closing direction and the contact pressure spring 18 is shrunk. Accordingly, the movable contact 3 is pressed to the fixed contact 2.
When an opening operation is performed from a state where the movable contact 3 comes into contact with the fixed contact 2, the driving shaft 8 is displaced to the opening direction as the open spring 9 and the contact pressure spring 18 are elastically restored. Accordingly, the latch plate 17 is displaced with respect to the spring frame 16 to be engaged with the spring frame 16. Also, after that, the driving shaft 8 is further displaced to the opening direction by the load of the open spring 9. Accordingly, the movable contact 3 is separated from the fixed contact 2.
The movable core 20 has major portions 23 arranged along the axis line direction; a pair of branch portions 24 which protrude in the opposite directions with each other from each side surface of the major portions 23, and a bulk material portion 101 which is connected to the driving shaft 8 and comes into contact with one seating surface of the open spring 9. Each of the major portions 23 is arranged parallel to the axis line direction on the outer position than the open spring 9 centering on the driving shaft 8. Each branch portion 24 protrudes from the major portion 23 along a direction perpendicular to the axis line direction. The driving shaft 8 is fixed to the movable core 20 by being fixed to the bulk material portion 101.
The fixed core 19 has a first fixed core portion 26 and a pair of second fixed core portions 27 which are provided on the first fixed core portion 26 and arranged avoiding a region where the movable core 20 displaces (
The first fixed core portion 26 has a lateral core portion 28 which is located parallel to each branch portion 24 and a pair of longitudinal core portions 29 which extend toward each branch portion 24 from both end sections of the lateral core portion 28. The driving shaft 8 passes through the lateral core portion 28 so as to be capable of displacing in the axis line direction. In this example, a bearing is provided on the support plate 7 and the driving shaft 8 passes through the bearing. Each of the longitudinal core portions 29 is located along the axis line direction. At least the first fixed core portion 26 is overlapped with a region of the movable core 20 within a projected surface in the axis line direction.
Each of the second fixed core portions 27 is joined to one longitudinal core portion 29 and the other longitudinal core portion 29. Furthermore, each second fixed core portion 27 sandwiches each longitudinal core portion 29 in a direction perpendicular to the axis line direction. In addition, each second fixed core portion 27 is located out of the region of the movable core 20 within the projected surface in the axis line direction. Further, each second fixed core portion 27 has a yoke core portion 30 parallel to the lateral core portion 28 and a pair of spacers 31 each intervening between the yoke core portion 30 and each longitudinal core portion 29.
Each yoke core portion 30 is located spaced apart from the major portion 23 in a direction perpendicular to the axis line direction. Therefore, the distance between the yoke core portion 30 and the major portion 23 does not change even when the movable core 20 is displaced in the axis line direction. Material of each yoke core portion 30 and the spacer 31 is magnetic material such as steel material, electromagnetic soft iron, silicon steel, ferrite, and permalloy.
A first fixed surface 32 is provided on an intermediate portion of the lateral core portion 28 and a second fixed surface 33 is provided on an end section of each longitudinal core portion 29 (
A first movable surface 34 which faces the first fixed surface 32 in the axis line direction is provided on the major portion 23; and a second movable surface 35 which faces the second fixed surface 33 in the axis line direction is provided on an end section of each branch portion 24. The first movable surface 34 and each second movable surface 35 are surfaces perpendicular to the axis line direction.
The permanent magnet 22 is provided on each yoke core portion 30; and the permanent magnet 22 is located between each yoke core portion 30 and the major portion 23. Further, each permanent magnet 22 is located out of the region of the first movable surface 34 and the second movable surface 35 within a projected surface in the axis line direction. In this example, each permanent magnet 22 is located out of the region of the movable core 20 within the projected surface in the axis line direction.
Each permanent magnet 22 has an N pole and an S pole (a pair of magnetic poles). Accordingly, the permanent magnet 22 generates holding magnetic flux which holds the movable core 20 at the forward movement position. Furthermore, in each permanent magnet 22, only either N pole or S pole is located facing the major portion 23 in a direction perpendicular to the axis line direction. That is, a direction of the holding magnetic flux generated by each permanent magnet 22 is substantially perpendicular to the axis line direction between the permanent magnet 22 and the major portion 23. In this example, the N pole of each permanent magnet 22 faces the major portion 23 and the S pole of each permanent magnet 22 is fixed to the yoke core portion 30.
The electromagnetic coil 21 is located so as to pass through between the major portion 23 and the longitudinal core portion 29. In this example, the electromagnetic coil 21 surrounds the major portion 23 within a projected surface in the axis line direction. Accordingly, when the electromagnetic coil 21 is energized, the electromagnetic coil 21 generates magnetic flux which passes through the fixed core 19 and the movable core 20. Furthermore, a direction of the magnetic flux generated by the electromagnetic coil 21 can be inverted by switching of an energization direction to the electromagnetic coil 21. Incidentally, a central axis line of the electromagnetic coil 21 substantially coincides with an axis line of the switch device 1.
The major portion 23 and the branch portion 24 of the movable core 20 are a laminated body in which a plurality of thin sheets made of magnetic material are laminated in a direction perpendicular to the axis line direction.
Incidentally, a magnetic material with high permeability may be acceptable as a material of the major portion 23 and the branch portion 24 of the movable core 20; and, for example, steel material, electromagnetic soft iron, silicon steel, ferrite, and permalloy may be included. Furthermore, for example, the movable core 20 may be made of dust core in which iron powder is compressed and hardened. The first fixed core portion 26 is a laminated body in which thin sheets of magnetic material are laminated in a direction perpendicular to the axis line direction.
Each yoke core portion 30 is a steel member formed in a rectangular parallelepiped shape. The spacer 31 is a steel member formed in a plate shape having a predetermined thickness. The yoke core portion 30 and the spacer 31 are overlapped with the first fixed core portion 26 in the order of the spacer 31 and the yoke core portion 30 in the lamination direction of the thin sheets 39 of the first fixed core portion 26.
Incidentally, a magnetic material with high permeability may be acceptable as a material of the fixed core 19; and, for example, steel material, electromagnetic soft iron, silicon steel, ferrite, and permalloy may be included. Furthermore, for example, the fixed core 19 may be made of dust core in which iron powder is compressed and hardened. Further, in this example, the first fixed core portion 26 is produced by laminating thin sheets; however, the first fixed core portion 26 may be produced by integrally forming magnetic material or the first fixed core portion 26 may be produced by combining a plurality of divided bodies. Furthermore, in this example, the yoke core portion 30 is produced by integrally forming magnetic material; however, the yoke core portion 30 may be produced by laminating thin sheets or the yoke core portion 30 may be produced by combining a plurality of divided bodies.
One seating surface of the open spring 9 comes into contact with the bulk material 101 of the movable core 20, and the other seating surface comes into contact with the support plate 7. The open spring 9 is coaxially located with the driving shaft 8 and is located so as to passes through in the electromagnetic coil 21. Furthermore, the open spring 9 is located within an axial range of the fixed core 19. A part of the major portion 23 of the movable core 20 passes through the electromagnetic coil 21. In
When the movable core 20 is located at the forward movement position, the gap between the first fixed surface 32 and the first movable surface 34 and the gap between the second fixed surface 33 and the second movable surface 35 are narrower than those when the movable core 20 is located at the backward movement position. Accordingly, magnetic resistance of the first magnetic flux path 44 and the second magnetic flux path 45 becomes small. Therefore, the sucking force F1 between the first fixed surface 32 and the second movable surface 34 and the sucking force F2 between the second fixed surface 33 and the second movable surface 35 become large; and accordingly, the movable core 20 is held at the forward movement position against loads of the open spring 9 and the contact pressure spring 18. Furthermore, a summation of the sucking force F1, the sucking force F2, and the frictional force of the movable portion becomes not lower than the loads of the open spring 9 and the contact pressure spring 19; and thus the movable core 20 is held at the forward movement position.
Next, operation will be described. In the case of an opened state where the movable contact 3 is separated from the fixed contact 2, the movable core 20 is displaced to the backward movement position by the load of the open spring 9. The movable core 20 is sucked to the first fixed core portion 26 by energization to the electromagnetic coil 21; and thus, the movable core 20 is displaced from the backward movement position toward the forward movement position against the load of the open spring 9. Accordingly, the movable contact 3 is displaced toward the fixed contact 2.
After that, when the movable contact 3 comes into contact with the fixed contact 2, the displacement of the movable contact 3 is stopped. However, the movable core 20 is further displaced and reaches the forward movement position. Accordingly, the contact pressure spring 18 is shrunk and the movable contact 3 is pressed to the fixed contact 2 to complete the contact closing operation (
When the movable core 20 reaches the forward movement position, the movable core 20 is sucked and held to the first fixed core portion 26 by the holding magnetic flux of the permanent magnets 22, the holding magnetic flux passing through the first magnetic flux path 44 and the second magnetic flux path 45 (
In the case where the holding of the movable core 20 at the forward movement position is released, energization to the electromagnetic coil 21 is performed in a direction opposite to the case of the contact closing operation. When the energization to the electromagnetic coil 21 is performed, the sucking force between the movable core 20 and the first fixed core portion 26 is lowered as the whole and displacement of the movable core 20 from the forward movement position to the backward movement position is started by each load of the open spring 9 and the contact pressure spring 18. At this time, the movable contact 3 is being pressed to the fixed contact 2.
After that, when the movable core 20 is further displaced toward the backward movement position, the latch plate 17 is engaged with the spring frame 16. Also, after that, the movable core 20 is displaced toward the backward movement position; and accordingly, the movable contact 3 is separated from the fixed contact 2. The load of the open spring 9 is larger than the force in which the movable contact 3 of the vacuum valve 4 tries to close to the fixed contact 2. After that, the movable core 20 is further displaced to reach the backward movement position. Accordingly, the opening operation is completed (
In such electromagnet device 5, in an open contact state (
On the other hand, in the close contact state (
The load of the open spring 9 is exerted on the whole range of a movable range of the movable core 20; on the other hand, the load of the contact pressure spring 18 is exerted on a part of the movable range of the movable core 20; and accordingly, the whole length of the open spring 9 is longer than that of the contact pressure spring 18. Furthermore, the open spring 9 is coaxially located with the driving shaft 8 and located so as to pass through in the electromagnetic coil 21. The open spring 9 is located within an axial range of the fixed core 19. A part of the major portion 23 of the movable core 20 passes through the electromagnetic coil 21. In
The major portion 23 and the branch portion 24 of the movable core 20 and the first fixed core portion 26 of the fixed core 19 are main portions where the magnetic flux generated by the electromagnetic coil 21 passes through. The main portions are configured by laminating thin sheets of magnetic material in a substantially direction perpendicular to a direction of the magnetic flux generated by the electromagnetic coil 21; and therefore, when the electromagnetic coil 21 is energized to operate the electromagnet 10, eddy-current generated inside the magnetic material can be suppressed, operational delay due to the occurrence of the eddy-current can be prevented, and the switch device 1 can be driven with temporally high accuracy.
Furthermore, in the magnetic flux generated by the electromagnetic coil 21, the magnetic flux going around just proximal to the electromagnetic coil 21 is the strongest according to the least action principle in physics. The major portion 23 and the branch portions 24 of the movable core 22 are directly faced to the electromagnetic coil 21 and the bulk material 101 is located in a region where the generated magnetic flux is weak; and therefore, influence on the operation of the electromagnet 10 is small and thus the switch device 1 can be driven with temporally high accuracy.
The sucking force generated by the magnetic flux of the permanent magnets of the electromagnet 10 is the strongest when the force is exerted in the axial direction. When a load of a component in a direction perpendicular to the axial direction is applied, the sucking force degrades. Therefore, when the seating surface of the open spring 9 is inclined, the load of the component in the direction perpendicular to the axial direction is generated; and therefore, the inclination of the seating surface needs to be suppressed. One seating surface of the open spring 9 comes into contact with the bulk material 101 of the movable core 20 and the other seating surface comes into contact with the support plate 7; and therefore, the inclination of the seating surface of the open spring 9 can be suppressed than the case where the seating surfaces are received by laminated surfaces of the laminated thin sheets and degradation of the sucking force of the electromagnet 10 due to the inclination of the load of the open spring 9 can be suppressed.
In the electromagnet device 5 of Embodiment 1, the support plate 7 is made of non-magnetic material; and accordingly, degradation of the sucking force of the electromagnet 10 can be suppressed. The configuration of the case where the sucking force of the electromagnet 10 degrades is shown in
In
In the electromagnet device 5 of Embodiment 1, the bulk material 101 of the movable core 20 of the electromagnet 10 is made of non-magnetic material; and accordingly, a part of the magnetic material's closed circuit in which the magnetic flux generated by the permanent magnet 22 passes through the open spring 9 is non-magnetized and thus degradation of the sucking force of the electromagnet 10 can be suppressed as in Embodiment 2.
The driving shaft 8 is made of non-magnetic material in Embodiment 1; however, in the configuration of Embodiment 2 or Embodiment 3, the driving shaft 8 can use steel material serving as magnetic material. The reason is that the support plate 7 or the bulk material 101, which is made of non-magnetic material, exists between paths of the permanent magnet 22 and the driving shaft 8 and therefore the support plate 7 or the bulk material 101 does not become the path of the magnetic flux generated by the permanent magnet 22; and thus, the sucking force of the movable core 20 and the fixed core 19 does not degraded by the fact that the driving shaft 8 is made of magnetic material. Magnetic material can be adopted for the driving shaft 8; and accordingly, a low cost and high strength steel material can be used for the driving shaft 8 and low cost and stable operation of the electromagnet device 5 can be achieved.
In the electromagnet device 5 of Embodiment 1, the open spring 9 is made of non-magnetic material; and accordingly, the open spring 9 of the magnetic material's closed circuit in which the magnetic flux generated by the permanent magnet 22 passes through the open spring 9 is non-magnetized and thus degradation of the sucking force of the electromagnet 10 can be suppressed as in Embodiment 2.
A load of the open spring 9 is exerted on the whole range of a movable range of the movable core 20. On the other hand, a load of the contact pressure spring 18 is exerted on a part of the movable range of the movable core 20; and accordingly, the whole length of the open spring 9 is longer than that of the contact pressure spring 18. Furthermore, the open spring 9 is located coaxially with the driving shaft 8 and located on a peripheral portion of the electromagnet 10. The open spring 9 is located within an axial range of the electromagnet 10. By the aforementioned arrangement, the axial length of the electromagnet device 5 can be shortened than the case where the electromagnet 10 and the open spring 9 are arranged in the axial direction. Therefore, the whole length of the switch device 1 using this electromagnet device 5 can be shortened.
The open springs 9 are divided and are symmetrically arranged with respect to the driving shaft 8. An open spring support 125 which receives a load of the open spring 9 is located coming into contact with the seating surface of the open spring 9 and a driving shaft 127 is attached to the open spring support 125. The other end of the driving shaft 127 is connected to the second connection link 129 by a pin 131. The other end of the second connection link is connected to the driving lever 119 by a pin 133.
In the electromagnet device 5 configured as shown in
Any electromagnet device 5 of the aforementioned Embodiment 1 to Embodiment 11 is applied; and accordingly, the whole length of the switch device 1 using the electromagnet device 5 can be shortened and reduction in size can be achieved.
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP2009/005745 | 10/29/2009 | WO | 00 | 3/9/2012 |
