WO2023246667A1

WO2023246667A1 - Electromagnetic mechanism

Info

Publication number: WO2023246667A1
Application number: PCT/CN2023/100908
Authority: WO
Inventors: 胡建国; 肖体锋; 李帅; 杨辉; 徐胜国
Original assignee: 浙江正泰电器股份有限公司
Priority date: 2022-06-23
Filing date: 2023-06-17
Publication date: 2023-12-28
Also published as: CN117316711A

Abstract

An electromagnetic mechanism, comprising a coil, a core arranged in the coil, an outer magnet yoke and an inner magnet yoke, wherein the inner magnet yoke is located between the coil and the outer magnet yoke; a permanent magnet is provided on the inner magnet yoke; an inner bending pin bent in the direction of the core is provided on a side face of the inner magnet yoke that is close to the core; the inner bending pin is provided with an avoidance groove for avoiding the core; and a first air gap is formed between the periphery of the core and the inner bending pin. The inner bending pin of the inner magnet yoke is provided with the avoidance groove for avoiding the core, the first air gap in contact with the inner magnet yoke is formed on the periphery of the core, a new magnetic circuit is formed on an outer side of the inner magnet yoke by means of the first air gap, and the permanent magnet attracts the new magnetic circuit, such that the characteristics of attraction and release can be guaranteed. In addition, there is no need to use a gasket, thereby solving the problems caused by a gasket of an increase in assembly difficulty, it being difficult to control the size, and serious assembly errors.

Description

Electromagnetic mechanism

Technical field

The invention relates to the field of low-voltage electrical appliances, and specifically relates to an electromagnetic mechanism.

Background technique

As a driving component, the electromagnetic mechanism is widely used in various control appliances, usually including brackets, moving parts, stationary parts, coils and elastic parts. The coil can form an electromagnetic force between the moving parts and the stationary parts, driving the moving parts to overcome the After the electromagnetic force formed by the coil disappears due to the force movement of the elastic part, the moving part can move in the opposite direction driven by the restoring force of the elastic part.

When a DC electromagnetic mechanism uses permanent magnets, in order to reduce magnetic flux leakage, a gasket is usually used to form an air gap between the moving part and the stationary part in order to achieve reliable attraction and release characteristics. However, the thickness of the gasket is usually relatively thin. , not only is the gasket itself prone to deformation, which increases the difficulty of assembling the electromagnetic mechanism, but the size of the gasket is also difficult to control and assembly errors are large, which in turn affects the stability of the electromagnetic mechanism.

Contents of the invention

The purpose of the invention is to overcome the shortcomings of the prior art and provide an electromagnetic mechanism that does not require the use of gaskets, has low precision requirements, and has reliable pull-in and release action characteristics.

In order to achieve the above objects, the present invention adopts the following technical solutions:

An electromagnetic mechanism includes a coil, an iron core arranged in the coil, an outer magnetic yoke and an inner magnetic yoke. The inner magnetic yoke is located between the coil and the outer magnetic yoke. A permanent magnet is provided on the inner magnetic yoke. The inner magnetic yoke The yoke is provided with inward bending legs on the side close to the iron core that are bent in the direction of the iron core. The inward bending legs are provided with escape grooves for avoiding the iron core. A first air gap is formed between the bent legs.

Preferably, a bushing is provided around the iron core, the distance a from the side wall of the escape groove to the iron core is greater than the thickness of the bushing, and the bushing extends into the first air gap and is connected to the first air gap. The side walls of the escape groove are arranged at intervals.

Preferably, the outer yoke is provided with an outer bending leg bent in the direction of the iron core. The outer bending leg is arranged opposite to the inner bending leg. The outer bending leg is in contact with the inner bending leg in the axial direction of the iron core. Between the inner bending legs, there is an iron For an armature connected to the core, the distance D1 from the inner bending leg to the outer bending leg of the outer yoke minus the thickness D2 of the armature is greater than the distance a from the side wall of the escape groove to the iron core in the radial direction of the iron core.

Preferably, the side wall of the escape groove is an arc-shaped escape surface, and the distance from each position on the escape surface to the corresponding surface of the iron core is equal and is a.

Preferably, the outer yoke includes a side plate and an outer bending leg, and the permanent magnet is arranged between the side plate and the inner yoke. In the axial direction of the iron core, the armature reaches the end of the outer bending leg. The farthest distance is b, the farthest distance from the armature to the inner bending leg is c, and b=c>a.

Preferably, in the axial direction of the iron core, the minimum distance between the armature and the side plate is d, and d>b=c; the length of the contact between one end of the armature and the outer bending leg is less than or equal to 6 mm. .

Preferably, the permanent magnet generates a first electromagnetic circuit, a second electromagnetic circuit and a third electromagnetic circuit respectively when the coil is energized;

The first electromagnetic circuit passes through the permanent magnet, the outer magnetic yoke, the iron core, the first air gap and the inner magnetic yoke in sequence and then returns to the permanent magnet;

The second electromagnetic circuit passes through the permanent magnet, outer yoke, armature, moving iron core and inner yoke in sequence and then returns to the permanent magnet;

The third electromagnetic circuit passes through the outer magnetic yoke, the iron core, the armature and the outer magnetic yoke in sequence.

Preferably, a second magnetic conductor is provided at one end of the iron core away from the first air gap, and a sleeve is provided between the second magnetic conductor and the iron core.

Preferably, it includes two outer magnetic yokes and two inner magnetic yokes, the two outer magnetic yokes are arranged oppositely, the two inner magnetic yokes are arranged oppositely between the two outer magnetic yokes, the outer magnetic yoke includes a side plate, and The two ends of the side plate are respectively provided with upper bending legs and outer bending legs. The permanent magnet is arranged between the side plate and the inner yoke. The outer bending legs are arranged opposite to the inner bending legs. The armature is arranged on Between the outer bending leg and the inner bending leg, one side of the armature is connected to one end of the iron core. The armature is provided with a partition on the side away from the iron core, and a supporting plate is provided on the side of the partition away from the armature. The supporting plate, partition plate and armature are connected to the iron core through screws or rivets.

Preferably, the coil is installed on the coil bobbin, which includes a cylinder and a base and a cover plate integrally formed at both ends of the cylinder. The iron core is installed inside the cylinder, and the coil is installed on the inside of the cylinder. Outside, and between the base and the cover, the base is provided with an inner mounting groove and an outer mounting groove respectively, and the inner mounting groove and the outer mounting groove cooperate with the inner yoke and the outer yoke respectively.

The electromagnetic mechanism created by the present invention is provided with an inner bending leg on the inner yoke for avoiding the iron core. The avoidance groove forms a first air gap around the iron core that is in contact with the inner magnetic yoke. A new magnetic circuit is formed on the outside of the inner magnetic yoke through the first air gap, and then the new magnetic circuit is attracted by the permanent magnet, which not only ensures the attraction and release characteristics, and does not require the use of gaskets, which can avoid the problems of increased assembly difficulty, difficult size control, and large assembly errors caused by gaskets.

In addition, the first air gap prevents the main magnetic circuit from going directly from the iron core to the inner yoke, but must pass through the armature, so that the permanent magnet generates upward attraction to the armature, ensuring the upward force of the iron core and ensuring reliable reset.

Description of the drawings

Figure 1 is an exploded view of the electromagnetic mechanism created by the present invention;

Figure 2 is a schematic structural diagram of the inner magnetic yoke 13 created by the present invention;

Figure 3 is a schematic diagram of the cooperation between the inner yoke 13 and the iron core 16 created by the present invention;

Figure 4 is a cross-sectional view of the electromagnetic mechanism created by the present invention when the power is turned off;

Figure 5 is a cross-sectional view of the electromagnetic mechanism created by the present invention when it is energized;

Figure 6 is a schematic structural diagram of the outer magnetic yoke 11 created by the present invention;

Figure 7 is another structural schematic diagram of the inner magnetic yoke 13 created by the present invention;

Figure 8 is another cross-sectional view of the electromagnetic mechanism created by the present invention;

Figure 9 is a schematic structural diagram of the coil bobbin 15 created by the present invention;

Figure 10 is a cross-sectional view of the coil bobbin 15 created by the present invention.

Detailed ways

The specific implementation of the electromagnetic mechanism created by the present invention will be further described below with reference to the embodiments given in the accompanying drawings. The electromagnetic mechanism created by the present invention is not limited to the description of the following embodiments.

As shown in Figures 1-3, the electromagnetic mechanism created by the present invention includes a coil 14, an iron core 16 arranged inside the coil 14, an outer yoke 11 and an inner yoke 13. The inner yoke 13 is located between the coil 14 and the outer yoke. 11, a permanent magnet 12 is provided on the inner yoke 13. The inner yoke 13 is provided with an inner bending leg 131 that is bent toward the iron core 16 on the side close to the iron core 16. The leg 131 is provided with an escape groove 132 for avoiding the iron core 16 , and a first air gap 100 is formed between the periphery of the iron core 16 and the side wall of the escape groove 132 .

In the electromagnetic mechanism created by the present invention, an escape groove 132 for avoiding the iron core 16 is provided on the inner bending leg 131 of the inner yoke 13, so that a first air gap is formed between the side walls of the escape groove 132 around the iron core 16. 100, The outside of the inner magnetic yoke 13 forms a new magnetic circuit through the first air gap 100, and then attracts the new magnetic circuit through the permanent magnet 12. This not only ensures the attraction and release characteristics, but also does not require the use of gaskets, which can avoid assembly difficulties caused by gaskets. Problems such as increase in size, difficulty in controlling size and large assembly errors.

As shown in Figures 1-3, the electromagnetic mechanism of this embodiment includes two outer magnetic yokes 11 and two inner magnetic yokes 13. The two outer magnetic yokes 11 are arranged oppositely, and the two inner yokes 13 are arranged oppositely at two locations. Between the outer yokes 11, permanent magnets 12 are respectively provided on the two inner yokes 13. The permanent magnets 12 are located between the outer yokes 11 and the inner yokes 13, and coils are provided between the two inner yokes 13. 14. An iron core 16 is provided inside the coil 14. The two inner yokes 13 are respectively bent with inner bending legs 131 on the sides close to the iron core 16. The plane of the inner bending legs 131 is perpendicular to the iron core 16. In the axial direction, the inner bending leg 131 is provided with an escape groove 132 for avoiding the iron core 16, and a first air gap 100 in contact with the inner yoke 13 is formed around the iron core 16, so The escape groove 132 is semicircular, with two inwardly bent legs 131 arranged at intervals. The two escape grooves 132 form an approximately circular hole surrounding one end surface of the iron core 16. The side wall of the escape groove 132 is an arc-shaped escape groove. noodle.

As shown in Figure 1-3, a bushing 8 is provided around the iron core 16. The distance a from the side wall of the escape groove 132 to the iron core 16 is greater than the thickness of the bushing 8. The bushing 8 can extend to all directions. The first air gap 100 is spaced apart from the side wall of the escape groove 132 .

As shown in Figure 3, preferably, the escape groove 132 is provided with an arc-shaped escape surface, and the distance from each position on the escape surface to the axis of the iron core 16 is equal, that is, in the direction of the plane where the inner bending leg 131 is located. The distance from each position on the escape surface to the corresponding surface of the iron core 16 is equal and is a.

Furthermore, an armature 7 connected to the iron core 16 is provided between the outer yoke 11 and the inner bending leg 131 . The outer yoke 11 is provided with an outer bending leg 111 that is bent toward the iron core 16. The outer bending leg 111 is opposite to the inner bending leg 131. The outer bending leg 111 and the inner bending leg 131 are arranged oppositely. There is an armature 7 connected to the iron core 16 between 131. There is a second air gap between the outer bending leg 111 and the inner bending leg 131. In the axial direction of the iron core 16, there is an armature 7. In the direction of movement of 16, the distance from the inner bending leg 131 to the outer bending leg 111 is D1. D1 minus the thickness D2 of the armature 7 is greater than the distance from the escape groove 132 to the iron core 16 in the radial direction of the iron core 16. The distance a, that is, D1-D2>a.

Since the magnitude of the electromagnetic force is determined by the magnitude of the magnetic flux density at the air gap on the surface of the armature 7, the direction points to the direction in which the air gap decreases. Therefore, the direction of the electromagnetic force points to the direction in which the air gap that generates the maximum electromagnetic force decreases. The first air gap 100 can prevent the main magnetic circuit from going directly from the iron core 16 to the inner yoke 13, but must pass through the armature 7, so that the permanent magnet 12 generates upward attraction to the armature 7, ensuring the upward force of the iron core 16 and ensuring that the reset can be Depend on.

Specifically, the outer yoke 11 includes a side plate 113. Upper bending legs 112 and outer bending legs 111 are respectively provided at both ends of the side plate 113. Two inner yokes 13 are provided on the two side plates 113. Inside, two side plates 113 are arranged opposite to the two inner yokes 13 respectively. The permanent magnet 12 is arranged between the side plates 113 and the inner yokes 13. The outer bending legs 111 are connected to the two inner yokes 113. The inner bending legs 131 are respectively arranged oppositely, and the armature 7 is arranged between the outer bending legs 111 and the inner bending legs 131. The distance from the inner bending legs 131 to the outer bending legs 111 is D1;

The second air gap includes an upper air gap and a lower air gap respectively located on both sides of the armature 7, that is, in the axial direction of the iron core 16, the upper air gap is located between the armature 7 and the inner bending leg 131, and the lower air gap It is located between the armature 7 and the outer bending leg 111 of the outer yoke 11. The size of the upper air gap and the lower air gap changes with the movement of the armature 7. When the armature 7 contacts the inner bending leg 131, the armature 7 bends outward. The farthest distance from the armature 7 to the outer bending leg 111 is b. When the armature 7 is in contact with the outer bending leg 111, it is the farthest distance from the armature 7 to the inner bending leg 131. The farthest distance of the bending leg 131 is c, and b=c>a.

During the suction process of the product, the magnetic force generated by the coil 14 is downward. At the beginning, the force generated by the permanent magnet 12 is maintained in the off state. As the suction force of the coil 14 increases and the downward stroke changes, the air gap changes accordingly, and the direction of the magnetic force It always points in the direction in which the air gap decreases. After reaching the equilibrium point of the air gap, the magnetic force of the permanent magnet 12 will change. When reaching the closed state, the coil 14 and the permanent magnet 12 work together to maintain the on state.

As shown in Figure 5, in the radial direction of the iron core 16, the minimum distance between the two ends of the armature 7 and the two side plates 113 of the outer yoke 11 is d respectively, and the d>b=c, the armature The length of the contact between the side surface of the armature 7 and the two outer bending legs 111 of the outer yoke 11 is e respectively, that is, the length of contact between either end of the armature 7 and the outer bending legs 111 is e, and e≤6mm.

As shown in Figure 4, after the power is turned off, there is no current in the coil 14, and the coil 14 does not produce magnetic force; the iron core 16 and the armature 7 move upward under the reaction force of the spring 1, and the armature 7 is in contact with the inner bending leg 131. At this time, only The first electromagnetic circuit 101 and the second electromagnetic circuit 102 when the permanent magnet 12 is excited:

The first electromagnetic interruption circuit 101 sequentially passes through the permanent magnet 12, the outer magnetic yoke 11, the iron core 16, the armature 7 and the inner magnetic yoke 13 and then returns to the permanent magnet 12. The first electromagnetic interruption circuit 101 is the main magnetic flux flowing through it. path of;

The second electromagnetic circuit 102 passes through the permanent magnet 12, the outer yoke 11, the second air gap and the inner yoke 13 in sequence and then returns to the permanent magnet 12. The second electromagnetic circuit 102 is the path through which the leakage flux flows. , the magnetic force is very small relative to the main magnetic circuit.

As shown in Figure 5, after the coil 14 is energized, it overcomes the force of the spring 1 and the magnetic force generated by the permanent magnet 12. The iron core 16 and the armature 7 move downward and push toward the outer yoke 11. In the process of pushing toward the outer yoke 11 , the air gap changes, the downward air gap changes from large to small, the magnetic force direction of the permanent magnet 12 points to the direction of the air gap decreasing, and becomes the joint action of the suction force generated by the coil 14 and the permanent magnet 12, pushing outward The magnetic yoke 11 is put on and held to complete the attraction.

As shown in Figure 5, after the product is attracted, the coil 14 continues to be energized, and the coil 14 generates a downward magnetic force on the armature 7, compressing the spring 1 and maintaining the stable state of electrification; at the same time, the permanent magnet 12 is excited to generate three magnetic circuits, which The armature 7 also generates a downward force to share the force of the coil 14 and save energy. The three magnetic circuits are the first electromagnetic circuit 201, the second electromagnetic circuit 202 and the third electromagnetic circuit 203 respectively;

The first electromagnetic circuit 201 passes through the permanent magnet 12, the outer yoke 11, the iron core 16, the first air gap 100 and the inner yoke 13 in sequence and then returns to the permanent magnet 12;

The second electromagnetic circuit 202 passes through the permanent magnet 12, the outer yoke 11, the armature 7, the moving iron core 16 and the inner yoke 13 in sequence and then returns to the permanent magnet 12;

The third electromagnetic circuit 203 passes through the outer magnetic yoke 11 , the iron core 16 , the armature 7 and the outer magnetic yoke 11 in sequence.

The main magnetic circuit generated by the coil 14 plays a leading role as the third electromagnetic circuit 203 in Figure 5. The second electromagnetic circuit 202 is its leakage magnetic flux, which is the same as the magnetic flux path generated by the permanent magnet 12, with opposite directions. Offset with no additional impact. The effective part of the magnetic circuit generated by the permanent magnet 12 is the second electromagnetic circuit 202 of the magnetic circuit. The magnetic circuit will be kept in a closed state to form a closed loop and activate the strengthening effect on the attraction state.

After the coil 14 is powered off, the force generated by the spring 1 resets, and starts to move against the force generated by the permanent magnet 12. During the reset process, the permanent magnet 12 changes from resistance to suction as the air gap changes, and the force generated by the spring 1 Together, the armature 7 is pushed toward the inner magnetic yoke 13, and the product is released.

As shown in Figure 1, the armature 7 is in the shape of a flat plate, and is connected to the iron core 16 through screws 3 or rivets. The armature 7 does not need to be connected to the iron core 16 through high-temperature assembly, which can significantly reduce the difficulty of assembly.

Further, the armature 7 is provided with a partition 5 on the side away from the iron core 16, and the partition 5 is provided with a supporting plate 4 on the side away from the armature 7. The supporting plate 4, partition 5 and armature 7 are connected by screws 3 or The rivets are connected to the iron core 16. The screws 3 or rivets pass through the supporting plate 4, the partition plate 5 and the armature 7 in sequence and then are connected to the iron core 16. This not only has the characteristics of convenient assembly, but also the partition plate 5 The force of spring 1 can be adjusted, and the supporting plate 4 can be used as the power source of the mechanism.

As shown in Figures 1 and 8-10, the coil bobbin 15 includes a cylinder 141 and a base 142 and a cover plate 143 integrally formed at both ends of the cylinder 141. The cover plate 143 is provided with a second spring 17. The iron core 16 is installed inside the cylinder 141, the coil 14 is installed outside the cylinder 141, and is located between the base 142 and the cover plate 143. The iron core 16 can move up and down inside the cylinder 141. In this embodiment The coil bobbin 15 does not need to be assembled from two independent parts, making it more convenient to use.

Furthermore, the base 142 is respectively provided with an inner mounting groove 154 and an outer mounting groove 155. The inner mounting groove 154 and the outer mounting groove 155 are respectively limitedly matched with the inner yoke 13 and the outer yoke 11. The base 142 is installed through the inner The groove 154 and the outer mounting groove 155 are used to install the inner yoke 13 and the outer yoke 11, which has the advantage of stability and reliability.

As shown in the specific embodiment shown in Figures 1-7, the electromagnetic mechanism of this embodiment includes an iron core 16, a coil bobbin 15 for setting the iron core 16 and defining the iron core 16, and a coil 14 wound on the coil bobbin 15. , the bracket 2 that supports the coil bobbin 15, the armature 7 connected to the iron core 16, the spring 1 arranged between the armature 7 and the bracket 2, and the position corresponding to the armature 7 and the iron core 16 and fixed on the coil bobbin 15 The yoke assembly of the spring 1 drives the armature 7 to move upward when the coil 14 is in a de-energized state.

The yoke assembly includes a pair of outer magnetic yokes 11 of the same shape and C-shaped (or U-shaped) corresponding to both sides of the aforementioned iron core 16 in a state of facing each other. A permanent magnet 12 and a pair of L-shaped inner magnetic yokes 13 are respectively provided on the inner side of 11. A working space is formed between the pair of outer magnetic yokes 11. The iron core 16, armature 7, coil 14, permanent magnet 12, inner magnetic The yoke 13 is arranged in the cavity surrounded by it. The permanent magnet 12 is located between the lower position of the cavity wall of the outer yoke 11 and the inner yoke 13 and is limited by the inner yoke 13 .

The iron core 16 is installed in the coil frame 15, and is connected to the armature 7 below, generally using screws 3, or riveting, etc. The partition 5, the supporting plate 4 and the partition 5 are installed below the armature 7 in sequence, using screws 3 is fixed on the iron core 16, and the supporting plate 4 can be used as a power source to drive other mechanisms to move along with the iron core 16 (not shown in the figure). The size and structure of the head of the support plate 4 can be designed according to needs, and the thickness can be adjusted by changing the number of partitions 5, which can then be used to adjust the reaction force of the screw 3, the position and stroke of the up and down movement of the support plate 4.

The armature 7 is installed between the outer bending legs 111 of a pair of outer yokes 11 and the inner bending legs 131 of a pair of inner yokes 13. When the coil 14 is released, it is reset by the action of the spring 1 and the permanent magnet 12, and is connected to a pair of inner bending legs 131. The inner magnetic yoke 13 is in contact; when the coil 14 is attracted, it overcomes the force of the spring 1 and attracts on the upper bending legs 112 of the pair of outer magnetic yokes 11. The attraction force of the coil 14 and the force of the permanent magnet 12 remain stable. Armature 7 and outside The contact length of the magnetic yoke 11 is e. The smaller the size e, the greater the magnetic induction intensity, the greater the holding force, and the more reliable the product is.

The iron core 16, the armature 7, a pair of inner and outer magnetic yokes 11, and a pair of inner magnetic yokes 13 are all made of magnetically conductive materials. That is to say, magnetically conductive materials are used as the iron core 16, the armature 7, a pair of inner and outer magnetic yokes 11, A pair of inner magnetic yokes 13. In this embodiment, the magnetic conductive material is electrically pure iron or iron, or steel. Silicon steel sheets can also be used.

The longitudinal cross-sectional shape of the iron core 16 is circular or square, and the iron core 16 is directly installed in the coil bobbin 15 around which the coil 14 is wound. The iron core 16 includes a lower column 161, a middle column 162 and an upper column 163. The size of the lower column 161 is smaller than that of the middle column 162. A bushing 8 is installed on the outside. The bushing 8 is made of plastic material such as PBT and is used to change the magnetic permeability and reduce the The number of passing magnetic field lines. The upper column 163 of the iron core 16 is used to connect a mechanism (not shown in the figure) that moves under the drive of the iron core. The mechanism drives other parts or contacts to move, such as contact support similar to that of a contactor, using screws or slots. The bayonet structure is connected to the iron core. The movement of the iron core drives the movement of the connected parts. The parts drive the movement of other parts or the contact points of parts installed on it to realize the movement function or the switching on and off of the contacts. The upper column of the iron core 16 163 generally has threaded holes, V-shaped or I-shaped grooves and other structures in the middle to facilitate connection and installation. The upper end of the spring 1 is supported on the armature 7 or the partition 5 below the armature 7, and the lower end is supported on the bracket 2. The bracket 2 is assembled with the coil bobbin 15 in the form of a buckle. Of course, it is also feasible to use a screw 3 structure; a pair of buffer members 6 are placed between the outer yoke 11 and the bracket 2, and the buffer parts 6 exert a force on the bracket 2. A pre-pressure ensures the stability of the bracket 2 position, ensures that the spring 1 position does not change, and improves the stability of the spring 1.

As shown in Figure 1, a pair of C-shaped outer yokes 11, the length of the upper upper bending leg 112 is greater than the length of the lower outer bending leg 111, and the upper bending leg 112 and the outer bending leg 111 are respectively installed on the coil. In the slot corresponding to the skeleton 15, the upper bending leg 112 is provided with a concave groove, which is consistent in shape with the center column 162, and has a size and a matching gap with the center column 162 to ensure reliable movement, ensuring that the up and down movement of the iron core 16 is flexible and reliable. The bending leg 111 is small in size and forms a magnetic circuit with the armature 7 in a closed state.

A pair of inner magnetic yokes 13, which is the biggest difference from conventional magnets, forms a new magnetic circuit through the inner bending legs 131. The inner bending legs 131 are provided with concave relief grooves 132, and the relief grooves 132 are An escape surface corresponding to the shape of the lower column 161 is provided to form a first air gap 100 with a constant distance a. A boss is punched out on the longitudinal plane of the inner yoke 13, with an upper limit boss 135, a lower limit boss 133, left and right bosses. The limiting boss 134 is used to limit the permanent magnet 12 .

As shown in the second specific embodiment shown in Figure 8, Figure 6 is based on Figure 2 and the iron core 16 is far away from the first A second magnetic conductor 18 is added to one end of the air gap 100, and a sleeve 19 is provided between the second magnetic conductor 18 and the iron core 16. The structure of the coil bobbin 15 and the lateral shape and structure above the outer magnetic yoke 11 are adjusted accordingly, so that the outer magnetic conductor 18 is The air gap between the magnetic yoke 11, the magnetic conductor 18 and the iron core 16 is as small as possible while ensuring flexible movement; the magnetic conductor 18 is made of magnetic material, and the use of the magnetic conductor increases the longitudinal contact direction with the iron core 16 , improving the stability of the magnetic circuit.

As shown in Figure 9-10, there is a through hole 151 in the middle of the coil bobbin 15, in which the iron core 16 can move freely; the coil bobbin 15 has two sections with different thicknesses in the middle, and the thick part can accommodate the magnet 18 inside; the coil bobbin 15 Installation slots are designed on the upper and lower sides to install the outer yoke 11 and the yoke 13; the slot 153 above the coil bobbin 15 is installed with the upper bending leg 112 above the outer yoke 11, and the outer installation slot 155 is used to install the outer yoke 11 below. The bending legs 111 and the inner mounting grooves 154 are installed with the inner bending legs 131 of the yoke 13 to realize the limiting, positioning and fixing of the yoke. The lower 156 boss is used for installation on the bracket 2.

It should be noted that in the description of the invention, the directions or positional relationships indicated by the terms "upper", "lower", "left", "right", "inner", "outer", etc. are based on those shown in the accompanying drawings. The orientation or positional relationship, or the orientation or positional relationship commonly placed during use, is only for convenience of description, and does not indicate that the device or component referred to must have a specific orientation, and therefore cannot be understood as a limitation on the invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish descriptions and cannot be understood as indicating relative importance.

The above content is a further detailed description of the present invention in combination with specific preferred embodiments. It cannot be concluded that the specific implementation of the present invention is limited to these descriptions. For those of ordinary skill in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which shall be deemed to fall within the protection scope of the present invention.

Claims

An electromagnetic mechanism includes a coil (14), an iron core (16) arranged in the coil (14), an outer magnetic yoke (11) and an inner magnetic yoke (13). The inner magnetic yoke (13) is located in the coil (14) Between the inner magnetic yoke (11) and the outer magnetic yoke (11), a permanent magnet (12) is provided on the inner magnetic yoke (13), which is characterized in that: the inner magnetic yoke (13) is provided with a directional magnet on the side close to the iron core (16). Inward bending legs (131) bent in the direction of the iron core (16). The inner bending legs (131) are provided with escape grooves (132) for avoiding the iron core (16). A first air gap (100) is formed between the four sides of (16) and the inward bending leg (131).
The electromagnetic mechanism according to claim 1, characterized in that: a bushing (8) is provided around the iron core (16), and the distance a from the side wall of the escape groove (132) to the iron core (16) is greater than The thickness of the bushing (8) extends into the first air gap (100) and is spaced apart from the side wall of the escape groove (132).
The electromagnetic mechanism according to claim 1, characterized in that: the outer magnetic yoke (11) is provided with an outer bending leg (111) bent in the direction of the iron core (16), and the outer bending leg (111) ) is arranged opposite the inner bending leg (131). An armature (7) connected to the iron core (16) is provided between the outer bending leg (111) and the inner bending leg (131). The distance D1 from the inner bending leg (131) in the axial direction of the core (16) to the outer bending leg (111) of the outer yoke (11) minus the thickness D2 of the armature (7) is greater than the distance in the core (11) 16) The distance a from the side wall of the escape groove (132) to the iron core (16) in the radial direction.
The electromagnetic mechanism according to claim 3, characterized in that: the side wall of the escape groove (132) is an arc-shaped escape surface, and the distance from each position on the escape surface to the corresponding surface of the iron core (16) is equal and All are a.
The electromagnetic mechanism according to claim 3, characterized in that: the outer yoke (11) includes a side plate (113) and an outer bending leg (111), and the permanent magnet (12) is arranged on the side plate (113) ) and the inner yoke (13), in the axial direction of the iron core (16), the farthest distance from the armature (7) to the outer bending leg (111) is b, and the armature (7) to The farthest distance of the inwardly bent leg (131) is c, and b=c>a.
The electromagnetic mechanism according to claim 5, characterized in that: in the axial direction of the iron core (16), the minimum distance from the armature (7) to the side plate (113) is d, and d>b =c; the length of the contact between one end of the armature (7) and the outer bending leg (111) is less than or equal to 6 mm.
The electromagnetic mechanism according to claim 1, characterized in that the permanent magnet (12) generates a first electromagnetic circuit (201), a second electromagnetic circuit (202) and a third electromagnetic circuit (202) respectively when the coil (14) is energized. Open the electromagnetic circuit(203);

The first electromagnetic circuit (201) passes through the permanent magnet (12), the outer yoke (11), the iron core (16), the first air gap (100) and the inner yoke (13) in sequence and then returns to its original position. The permanent magnet (12);

The second electromagnetic circuit (202) passes through the permanent magnet (12), the outer yoke (11), the armature (7), the moving iron core (16) and the inner yoke (13) in sequence and then returns to the permanent magnet (12). Magnet(12);

The third electromagnetic circuit (203) passes through the outer magnetic yoke (11), the iron core (16), the armature (7) and the outer magnetic yoke (11) in sequence.
The electromagnetic mechanism according to claim 1, characterized in that: a second magnetic conductor (18) is provided at one end of the iron core (16) away from the first air gap (100), and between the second magnetic conductor (18) and Sleeves (19) are provided between the iron cores (16).
The electromagnetic mechanism according to claim 1, characterized in that it includes two outer magnetic yokes (11) and two inner magnetic yokes (13), the two outer magnetic yokes (11) are arranged oppositely, and the two inner magnetic yokes (11) are arranged oppositely. 13) Located oppositely between two outer yokes (11), the outer yokes (11) include side plates (113), and upper bending feet (112) are respectively provided at both ends of the side plates (113). and an outer bending leg (111), the permanent magnet (12) is arranged between the side plate (113) and the inner yoke (13), the outer bending leg (111) and the inner bending leg (131) Arranged oppositely, the armature (7) is arranged between the outer bending leg (111) and the inner bending leg (131). One side of the armature (7) is connected to one end of the iron core (16). The armature (7) A partition (5) is provided on the side away from the iron core (16), and a support plate (4) is provided on the side of the partition (5) away from the armature (7). The support plate (4) and the partition (5) ) and the armature (7) are connected to the iron core (16) through screws (3) or rivets.
The electromagnetic mechanism according to claim 1, characterized in that: the coil (14) is installed on the coil bobbin (15), the coil bobbin (15) includes a cylinder (141) and two parts integrally formed on the cylinder (141). The base (142) and the cover plate (143) at both ends, the iron core (16) is installed inside the cylinder (141), the coil (14) is installed outside the cylinder (141), and is located on the Between the base (142) and the cover plate (143), the base (142) is respectively provided with an inner mounting groove (154) and an outer mounting groove (155). The inner mounting groove (154) and the outer mounting groove (155) are respectively It is limitedly matched with the inner yoke (13) and the outer yoke (11).