Electromagnetic relays

Abstract

To provide an improved electromagnetic relay.SOLUTION: An electromagnetic relay 1 includes: an electromagnet 8; multiple springs 4 each including a terminal and a contact that opens and closes according to the action of the electromagnet 8; and a base 2 supporting the springs 4. At least one of the multiple springs 4 has a locked part 29 that is locked to the base 2 utilizing the spring nature of the spring 4 and the base 2 has a locking portion 31 that locks the locked part 29.SELECTED DRAWING: Figure 5A

Description

Technical Field

[0001] The present invention relates to an electromagnetic relay.

Background Art

[0002] In a small electromagnetic relay with a rated load capacity level of about 8 to 10 A, when inserting a spring having contacts and terminals into a base, due to its small size, it is difficult to ensure sufficient press-fitting margin, resulting in problems such as insufficient press-fitting strength or various trade-offs for achieving press-fitting strength. Therefore, in electromagnetic relays, for example, the following countermeasures are often adopted, imposing burdens on manufacturing processes, product costs, etc., and then commercializing the products.

[0003] · If the spring remains thin, spring properties can be maintained, but there is a risk of deformation during the press-fitting process. Therefore, the spring is made thicker and firmly press-fitted with a short press-fitting margin. · Only the terminal portion of the spring is made thicker, and the spring portion is welded and joined to the terminal portion with a thin plate. However, in this case, the processing cost increases. · When press-fitting strength cannot be ensured, temporary adhesion of the spring is performed after the spring is inserted. However, in this case, the manufacturing cost increases, and when a load is applied to the spring terminal between inserting the spring into the base and performing temporary adhesion, there is also a risk of performing temporary adhesion with the spring remaining in a state of having moved from the correct position. Therefore, there is a need for an electromagnetic relay that prevents spring disengagement.

[0004] Also, generally, as contact methods of contacts of electromagnetic relays, point contact, sliding (where the contacts rub against each other), and rolling (where the contacts roll against each other) are known. When the contacts slide, a contact purification effect such as destruction of the oxide film on the contact surface and scraping off of wear powder occurs, improving contact reliability. Also, when the contact resistance of the contacts is low, heat generation can be suppressed. On the other hand, in the case of rolling, the contact purification effect decreases, but a large change in the contact points of the contacts can be expected, improving the anti-welding property during contact.

[0005] In the case of sliding type contacts, if contact wear causes large irregularities in the contacts, extra force is required for the contacts to overcome these irregularities during sliding. If this force exceeds the attractive force of the electromagnet pushing the spring, the card may not be able to fully push the spring. One way to suppress this phenomenon is to reduce the stiffness of the spring and allow a margin in the attractive force of the electromagnet, but in that case, the design must also take into account the current capacity of the spring.

[0006] Patent Document 1 discloses an electromagnetic relay in which the fixed portions of the movable contact spring and the fixed contact terminal plate are supported by a fixed block made of an insulator, and the fixed blocks are crimped together and inserted and fixed into an opening in an insulating base. This allows the movable contact spring and the fixed contact terminal plate to be fixed perpendicularly to the insulating base, thereby achieving stable contact pressure and contact gap.

[0007] Patent Document 2 discloses an electromagnetic relay in which a protrusion is formed on at least one of the side of the housing or the inner surface of the cover. It is described that this allows adhesive to flow into the gap between the housing and the cover even if the cover warps.

[0008] Patent Document 3 discloses a method for increasing the contact life of a movable contact and a fixed contact by bringing them into contact through rolling. [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] Japanese Utility Model Publication No. 2-145752 [Patent Document 2] Japanese Patent Publication No. 2020-21594 [Patent Document 3] Japanese Patent Publication No. 2006-59702 [Overview of the Initiative] [Problems that the invention aims to solve]

[0010] The objective of the present invention is to provide an improved electromagnetic relay in view of various problems with the conventional method. [Means for solving the problem]

[0011] One aspect of the present disclosure comprises an electromagnet, a plurality of springs having contacts and terminals that open and close in accordance with the operation of the electromagnet, and a base that supports the springs, wherein at least one of the plurality of springs has a terminal inserted into the base and a terminal In a direction perpendicular to both the opening and closing direction of the contact and the insertion direction of the terminal into the base. The base has a reference surface and a locking portion that protrudes from the reference surface, and the locking portion overcomes the locking portion when the terminal is inserted into the base. In the opening and closing direction of the aforementioned contact The present invention provides an electromagnetic relay that is elastically deformable, and the locking portion fixes the end of the locked portion on the side opposite to the insertion direction of the terminal relative to the base, thereby restricting the movement of the spring in the insertion direction. [Effects of the Invention]

[0013] According to one aspect of this disclosure, an improved spring slippage prevention technology can be provided. Specifically, the spring press-fitting strength previously required can be reduced, and spring slippage can be prevented even with thin springs. This is particularly useful for small electromagnetic relays. Furthermore, since the spring is inserted using its spring properties, it also leads to a reduction in mold abrasion and wear particles during press-fitting. In addition, since the need for temporary bonding is eliminated, the temporary bonding and drying processes can be eliminated, leading to a reduction in equipment costs, product costs, etc. According to other aspects of this disclosure, even if the cover warps inward, a sufficient adhesive layer can be obtained between the inner surface of the cover and the outer surface of the base. According to another aspect of this disclosure, adhesive flows into the notch on the reference surface side near the terminal exit of the through hole, ensuring a sufficient adhesive layer between the base and the terminal.

[0014] According to still another aspect of the present disclosure, it becomes possible to incorporate a rolling movement in addition to the sliding movement in the contact operation between the contacts. Thereby, while enjoying the merit of the contact cleaning action by sliding, the influence of the unevenness on the sliding path is dispersed, and it is also possible to realize the improvement of the anti-welding property at the time of contact of the contacts, which is the merit of rolling. According to still another aspect of the present disclosure, it is possible to hold the adhesive poured into the through hole from the outside of the electromagnetic relay near the through hole by surface tension and suppress the flow into the internal space. According to still another aspect of the present disclosure, it is possible to regulate the operation in which the fixed spring falls toward the movable spring by the reaction of being pushed in by the movable spring.

Brief Description of the Drawings

[0015] [Figure 1] [[ID=了12]]It is an exploded perspective view showing an example of an electromagnetic relay. [Figure 2] It is an exploded side view showing an example of an electromagnetic relay. [Figure 3] It is a plan view showing a part of an electromagnetic relay. [Figure 4] It is a perspective view showing an example of a movable spring. [Figure 5A] It is a V-V cross-sectional view showing an example of a spring structure. [Figure 5B] It is a V-V cross-sectional view showing an example of a spring structure. [Figure 6] It is a perspective view showing an example of a second fixed spring. [Figure 7] It is a VII-VII cross-sectional perspective view showing another example of a spring structure. [Figure 8A] It is a partial perspective view showing a modified example of the locked portion. [Figure 8B] It is a partial cross-sectional view showing a modified example of a spring structure. [Figure 9A] It is a partial perspective view showing another modified example of the locked portion. [Figure 9B] It is a cross-sectional view showing another modified example of a spring structure. [Figure 10A] It is a cross-sectional view showing the stress range when a dowel is adopted for the raised portion. [Figure 10B]This is a cross-sectional view XX showing the stress range when a cut and bent piece is used in the raised area. [Figure 11] This diagram shows the effect of internal warping of the cover. [Figure 12] This is a perspective view of a base showing an example of a step. [Figure 13] This is a schematic cross-sectional view XIII-XIII showing an example of the base-to-cover structural ratio. [Figure 14] This is a perspective view of the base showing a modified step. [Figure 15] This is a schematic cross-sectional view showing the adhesive layer between the terminal and the base. [Figure 16A] This is a bottom perspective view of an example of a base for securing an adhesive layer. [Figure 16B] This is a cross-sectional view of an example of a base for securing the adhesive layer. [Figure 17] This is a perspective view of an electromagnetic relay with the cover removed. [Figure 18] This is a disassembled perspective view of an electromagnetic relay. [Figure 19] This is a perspective view of a movable spring. [Figure 20] This is a front view of the movable spring. [Figure 21A] This is a side view showing the state in which the movable spring begins to contact the second fixed spring. [Figure 21B] This is a side view showing the movable spring fully pressed in by the card. [Figure 21C] This is a view of Figure 21B from above. [Figure 22] This diagram illustrates the contact path caused by rolling on a movable contact. [Figure 23] This is a perspective view of an electromagnetic relay with a movable spring mounted on the base. [Figure 24] This is a perspective view of the base where the first fixed spring, the movable spring, and the second fixed spring are mounted. [Figure 25] This is a partial perspective view of the base with the first fixed spring mounted. [Figure 26] This is a cross-sectional view from XXVI-XXVI in Figure 25. [Figure 27]This is a cross-sectional view of line XXVII-XXVII in Figure 24. [Figure 28] This is a perspective view showing the initial state of the first fixed spring, the movable spring, and the second fixed spring. [Figure 29] This is a front view of the second fixed spring. [Modes for carrying out the invention]

[0016] Embodiments of this disclosure will be described in detail below with reference to the attached drawings. In each drawing, identical or similar components are denoted by the same or similar reference numerals. Furthermore, the embodiments described below are not intended to limit the technical scope of the invention as described in the claims or the meaning of the terms used.

[0017] Figures 1 and 2 are exploded perspective and side views of an example electromagnetic relay 1, and Figure 3 is a plan view of a part of the electromagnetic relay 1. The electromagnetic relay 1 comprises a base 2 into which the components are assembled, and a box-shaped cover 3 that covers the base 2. For example, the base 2 and cover 3 may be molded parts made of resin. The components assembled in the base 2 include an electromagnet 8, a hinge spring 9, an armature 10, a card 11, and a spring 4 equipped with contacts and terminals that are opened and closed by the electromagnet 8.

[0018] The spring 4 includes multiple springs, each made of metal: a first fixed spring 5, a movable spring 6, and a second fixed spring 7. Hereinafter, these multiple springs will also be collectively referred to as "spring 4". The first fixed spring 5 has a first fixed contact 12, the movable spring 6 has a movable contact 13, and the second fixed spring 7 has a second fixed contact 14. Each of the springs 4 also has a spring portion 15 and a terminal 16. For example, the spring portion 15 is formed as a leaf spring. The spring portion 15 and the terminal 16 may be welded together or formed from a single thin sheet of metal.

[0019] The electromagnet 8 comprises a coil assembly 21, an iron core 22, and a yoke 23. The coil assembly 21 has two terminals 24, a coil 25 with windings connected to the terminals 24, and a bobbin 26 around which the coil 25 is wound.

[0020] In the electromagnetic relay 1, the electromagnet 8 is excited by applying a voltage between terminals 24. The excitation of the electromagnet 8 causes the abutment 10 to oscillate and be attracted to the iron core 22. The card 11 is attached to the abutment 10 and, as the abutment 10 oscillates, presses against the movable spring 6, causing the movable contact 13 to contact the second fixed contact 14 from the first fixed contact 12. The hinge spring 9 is attached to the abutment 10 and the yoke 23 and elastically biases one end of the abutment 10 away from the iron core 22.

[0021] When the voltage applied to terminal 24 is stopped, the axle 10 returns to its original position away from the iron core 22 due to the biasing force of the hinge spring 9. As the axle 10 returns to its original position, the pressing force from card 11 to the movable spring 6 is released, and the movable contact 13 separates from the second fixed contact 14.

[0022] With the above configuration, the electromagnetic relay 1 opens and closes the first fixed contact 12 and the movable contact 13, and the movable contact 13 and the second fixed contact 14. Note that the above configuration is just one example, and any components and principles may be used.

[0023] (Spring structure) Figure 4 is a perspective view of an example of a movable spring 6, and Figures 5A and 5B are VV cross-sectional views of an example of a spring structure. The movable spring 6 has a raised portion 28 that presses the movable spring 6 against the reference surface 27 of the base 2, and a locked portion 29 that is locked to the base 2. For example, the end of a U-shaped piece formed on the spring portion 15 is used as the locked portion 29, and the end of the U-shaped piece is formed to face backward in the insertion direction I of the movable spring 6. When the locked portion 29 receives an external force F, it elastically deforms due to its spring properties, and when the external force F is released, it returns to its original shape.

[0024] The base 2 has a reference surface 27 that defines the reference position of the movable spring 6 when attaching the movable spring 6 to the base 2, a press-fit surface 30 facing the reference surface 27, and a locking portion 31 that locks the movable spring 6. For example, a claw-shaped projection formed on the reference surface 27 may be used as the locking portion 31, and the claw-shaped projection may be provided in a direction different from the insertion direction I of the movable spring 6. The different direction may be any direction that can lock the locked portion 29, and may be a direction perpendicular to the insertion direction I or a direction inclined toward the front of the insertion direction I (the same applies hereinafter). Also, the claw-shaped projection may be formed on a surface perpendicular to the reference surface 27, rather than on the reference surface 27. In the initial stage of inserting the movable spring 6 into the base 2 as shown in Figure 5A, the raised portion 28 contacts the press-fit surface 30, and the locked portion 29 contacts the locking portion 31 and undergoes elastic deformation upon receiving force from the locking portion 31. As shown in Figure 5B, during the later stages of inserting the movable spring 6 into the base 2, the raised portion 28 receives force from the press-fit surface 30, pressing the movable spring 6 against the reference surface 27, while the locked portion 29, due to its restoring force, slides under the locking portion 31 and engages with the lower part of the locking portion 31. In other words, the movable spring 6 is self-locked during the insertion process. The locking portion 31 restricts the movement of the locked portion 29 in the direction opposite to the insertion direction I of the movable spring 6, thereby preventing the movable spring 6 from coming loose. Note that although the electromagnetic relay 1 described here is a type in which the movable spring 6 is inserted vertically into the base 2, a type in which the movable spring is inserted horizontally is also acceptable.

[0025] This reduces the spring press-fitting strength, preventing spring detachment even with thin springs. Therefore, the spring structure in this example is particularly useful for small electromagnetic relays. Furthermore, since the movable spring 6 is inserted using the spring properties of the locked portion 29, it also leads to a reduction in mold abrasion and wear particles during press-fitting. In addition, since temporary bonding of the movable spring is not required, the temporary bonding and drying processes can be eliminated, leading to a reduction in equipment costs and product costs. Moreover, the potential risk of spring detachment during the process from spring insertion to bonding, which occurred in the past, is eliminated.

[0026] The self-locking structure in this example may also be applied to the first fixed spring 5 and the second fixed spring 7. Figure 6 is a perspective view of an example of the second fixed spring 7, and Figure 7 is a VII-VII cross-sectional perspective view of another example of the spring structure. The second fixed spring 7 has a raised portion 28 that presses the second fixed spring 7 against the reference surface 27 of the base 2, and a locked portion 29 that is locked to the base 2. For example, the inclined end of the base 32 of the terminal 16 is made up of an inclined angle, and the inclined end is formed to face backward in the insertion direction I of the second fixed spring 7. When the locked portion 29 receives an external force F, it elastically deforms due to its spring properties, and when the external force F is released, it returns to its original shape.

[0027] The base 2 has a reference surface 27 that defines the reference position of the second fixed spring 7, a press-fit surface 30 that faces the reference surface 27, and a locking portion 31 that locks the second fixed spring 7. For example, a recessed edge formed on the press-fit surface 30 side is used as the locking portion 31, and the recessed edge extends in a direction different from the insertion direction I of the second fixed spring 7. Note that the recessed edge includes not only the recessed side wall portion but also the portion of the press-fit surface 30 (the same applies hereinafter). In the initial stages of inserting the second fixed spring 7 into the base 2, the raised portion 28 (not shown in Figure 7) contacts the press-fit surface 30, and the locked portion 29 contacts the locking portion 31 (the portion of the press-fit surface 30) and receives force from the locking portion 31 (the portion of the press-fit surface 30) and undergoes elastic deformation (not shown). In the later stages of inserting the second fixing spring 7 into the base 2, the raised portion 28 receives force from the press-fitting surface 30, pressing the second fixing spring 7 against the reference surface 27, and the locked portion 29 engages with the locking portion 31 by the restoring force. In other words, the second fixing spring 7 is self-locked during the insertion process. The locking portion 31 restricts the movement of the locked portion 29 in the direction opposite to the insertion direction I of the second fixing spring 7, thereby preventing the second fixing spring 7 from coming loose.

[0028] Figure 8A is a partial perspective view showing a modified example of the locking portion 29 of the movable spring 6, and Figure 8B is a partial cross-sectional view showing a modified example of the self-locking structure. In Figure 8A, the end of a V-shaped piece formed near the base of the terminal 16 of the movable spring 6 is used as the locking portion 29. The end of the V-shaped piece is formed to face backward in the insertion direction I of the movable spring 6. When the locking portion 29 receives an external force F, it elastically deforms due to its spring properties, and when the external force F is released, it returns to its original shape. In Figure 8B, a recessed edge formed on the press-fit surface 30 is used as the locking portion 31, and the recessed edge extends in a direction different from the insertion direction I of the movable spring 6. In the initial stages of inserting the movable spring 6 into the base 2, the locking portion 29 contacts the locking portion 31 (the part of the press-fit surface 30) and receives force from the locking portion 31 (the part of the press-fit surface 30) and elastically deforms. Towards the end of the insertion of the movable spring 6 into the base 2, the locked portion 29 is forced into the locking portion 31 by the restoring force and engages with the locking portion 31. In other words, the movable spring 6 is self-locked during the insertion process. The locking portion 31 restricts the movement of the locked portion 29 in the direction opposite to the insertion direction I of the movable spring 6, thereby preventing the movable spring 6 from coming loose.

[0029] Figure 9A is a partial perspective view showing another modified example of the locking portion 29, and Figure 9B is a cross-sectional view showing another modified example of the self-locking structure. The locking portion 29 in Figure 9A is also a projection that protrudes laterally from the terminal 16, and the projection is formed to face laterally in the insertion direction I of the movable spring 6. When the locking portion 29 receives an external force F, it elastically deforms due to its spring properties, and when the external force F is released, it returns to its original shape. In addition, the locking portion 31 in Figure 9B is a claw-shaped projection that protrudes from the reference surface 27, and the claw-shaped projection protrudes in a direction different from the insertion direction I of the movable spring 6.

[0030] (Spring reference surface pressing shape) Referring again to Figure 4, the raised portion 28 that presses the movable spring 6 against the reference surface may be a partially cut dowel (protrusion) (raised portion 28 on the right side of Figure 4), but if any of the various spring release prevention structures described above are adopted, a cut-up piece formed by cutting and bending a part of the movable spring 6 is preferable (raised portion 28 on the left side of Figure 4). Figure 10A is a cross-sectional view showing the range A of spring stress when a dowel is used for the raised portion, and Figure 10B is a cross-sectional view XX showing the range B of spring stress when a cut-up piece is used for the raised portion.

[0031] When the movable spring 6 is attached to the base, if the locked portion 29 moves over the locking portion 31, the movable spring 6 needs to elastically deform by the height of the locking portion 31 to absorb that height. If the raised portion 28 is formed with a dowel, stress concentrates in a relatively narrow area A of the movable spring 6 due to the distance between the locking portion 31 and the raised portion 28, causing the spring to plastically deform and leading to a decrease in self-locking performance. To alleviate the stress while using a dowel, the spring width can be increased or the locking portion 31 can be placed higher on the base 2 to distribute the stress, but applying this to a small electromagnetic relay would also affect the insulation distance and the width of the spring roll material.

[0032] Therefore, from the viewpoint of suppressing plastic deformation of the spring, stress can be distributed by forming the raised portion 28 with a cut and bent piece instead of a dowel. When a cut and bent piece is used as the raised portion 28, when the movable spring 6 elastically deforms by the height of the locking portion 31 and the locked portion 29 overcomes the locking portion 31 of the base 2, the distance between the locking portion 31 and the root 28a of the cut and bent piece becomes relatively large, and the stress is distributed over a relatively wide area B of the movable spring 6, thereby suppressing plastic deformation of the spring. It should also be noted that the cut and bent piece can be used not only for the movable spring 6 but also for the first fixed spring 5 and the second fixed spring 7.

[0033] (Ensuring an adhesive layer between the base and cover) The cover 3 of the electromagnetic relay 1 is thin-walled, and the cover 3 may warp inward during molding. Figure 11 shows the effect of the inward warping of the cover 3. The base 2 has an outer surface 41 that faces the inner surface 40 of the cover. If the outer surface 41 is flat, when the warped cover 3 is placed over the base 2, the design clearance between the base 2 and the cover 3 (the design size of the gap between the base 2 and the cover 3) provided as the adhesive layer 42 between the base and the cover is compressed, and a thin area C occurs in the adhesive layer 42. When the adhesive layer 42 becomes thin, the cover and the base cannot be sufficiently sealed, which can cause poor airtightness.

[0034] Therefore, a step is formed on the outer surface 41 facing the inner surface 40 to secure an adhesive layer 42. Figure 12 is a perspective view of a base 2 with an example of a step 43 formed thereon. For example, the step 43 is a recess 46 that is one step lower than the outer surface 41. As shown in Figure 11, the inward curvature of the cover 3 is greatest near the middle of the opening edge of the cover 3. Therefore, by forming a step 43 on the outer surface 41 on the cover edge 44 side and near the middle 45 (see Figures 1 and 2) of the cover 3 side, an adhesive layer with sufficient clearance between the inner surface 40 and the outer surface 41 can be obtained even if the cover 3 curves inward.

[0035] The optimal structural ratio of the thickness of the adhesive layer 42 and the height and depth of the step 43 can be determined in relation to the curvature shape and amount of curvature of the cover 3, the properties of the adhesive, and the bonding strength of the resin material (base-cover).

[0036] Figure 13 is a schematic cross-sectional view of XIII-XIII showing an example of the base-cover structural ratio. The symbol "3" indicates a cover without warping, the symbol "3'" indicates a cover with warping, and the symbol "3''" indicates a cover whose warping is restricted by a step 43 formed on the outer surface 41 of the base 2. For example, if the design clearance z between the base 2 and the cover 3 is 0.05 mm, the target adhesive layer thickness (desired adhesive layer thickness) y1 at the cover edge 44 is 0.04 mm or more, the depth y2 of the step 43 is 1.5 mm, the height a of the step 43 is 0.1 mm, the cover warping length L is 12.7 mm, and the cover warping amount d at the cover edge 44 is 0.1 mm, then the cover warping amount x (=0.057 mm) at the cover edge 44 can be calculated from the following formula.

[0037]

number

[0038] Furthermore, the adhesive layer thickness (=0.093 mm) at the position of the cover edge 44 after assembly can be determined from the following formula. Therefore, in the case of the above structural ratio, the minimum adhesive thickness is 0.093 mm, the adhesive flow depth (corresponding to the depth of the step 43) is 1.5 mm, and it can be seen that a target adhesive layer thickness y1 of 0.04 mm or more has been obtained.

[0039]

number

[0040] If a target adhesive layer thickness y1 of 0.04 mm or more cannot be obtained based on the above formula, the target adhesive layer thickness can be obtained by readjusting at least one of the height a or depth y2 of the step 43. The height and depth of the step 43 should be set in this manner.

[0041] Note that the step 43 may be a projection 47 extending from the outer surface 41 instead of a recess 46. Figure 14 is a perspective view of the base 2 showing a modified example of the step 43. The projection 47 corrects the inwardly curved cover 3 from the inside, ensuring the designed clearance between the cover and the base. In the example in Figure 14, the projection 47 is formed on the outer surface 41 on the edge 44 side of the cover and at approximately equal intervals from the middle of the side 45. The height of the projection 47 is appropriate to the design clearance between the base and cover during assembly. With the step 43 described above, even if the cover curves inward, a sufficient clearance can be secured in the adhesive layer, allowing the adhesive to flow in from the cover edge 44 and ensure the sealing performance of the electromagnetic relay 1. The step 43 may also be formed on the inner surface 40 instead of the outer surface 41.

[0042] (Adhesion between terminal and base) In small electromagnetic relays, the spring terminals are often thin, and there are height limitations, which restricts the amount of adhesive layer that can be obtained between the terminal and the base. Figure 15 is a schematic cross-sectional view showing the adhesive layer 50 between the terminal and the base. When a load is applied to such a terminal 16, stress is generated in the adhesive around the terminal 16, causing delamination of the adhesive layer 50 or cracks in the adhesive layer around the terminal 16, and in the case of sealed products, there is a risk of airtightness failure. Also, if the inner surface 52 of the insertion hole 51 through which the terminal 16 is inserted is on the same plane as the reference surface 27, the terminal 16 and the reference surface 27 are in contact, making it difficult for the adhesive to penetrate the inner surface 52, resulting in the formation of thin areas D in the adhesive layer 50 on the reference surface 27 side. As a countermeasure, one method is to lower the entire area around the terminal 16 of the base 2 by one step, but there are limitations.

[0043] Therefore, it is necessary to secure an adhesive layer 50 on the reference surface 27 side near the lower side of the insertion hole 51. Figure 16A is a bottom perspective view of an example of a base 2 that secures the adhesive layer, and Figure 16B is a cross-sectional view of the base 2 taken along line XVI-XVI. The base 2 has a notch 54 on the reference surface 27 side near the terminal exit of the insertion hole 51. For example, the notch 54 has an inclined surface that is tilted with respect to the reference surface 27. By forming an inclined surface, the adhesive can flow more easily into the notch 54. Note that the notch 54 may be a recessed area that is stepped down from the reference surface 27, rather than an inclined surface. The notch 54 can increase the adhesive layer between the terminal and the base on the reference surface side, thereby improving the airtightness of the electromagnetic relay. In addition, the resistance of the adhesive layer to crack formation when a load is applied to the terminal 16 is improved. Even if the entire area around the terminal is stepped down in addition to the notch 54, the terminal strength can be improved.

[0044] (Movable spring slit shape) The slit shape and other configurations of the movable spring will be described. Figure 17 is a perspective view of the electromagnetic relay 200 with the cover removed. Figure 18 is an exploded perspective view of the electromagnetic relay 200. As shown in Figures 17 and 18, the electromagnetic relay 200 comprises a base 204 into which the components are assembled, and a cover 206 that covers the base 204. The base 204 and the cover 206 are, for example, molded parts made of resin. The base 204 and the cover 206 constitute the housing.

[0045] The components incorporated into the base 204 include a plurality of springs (first fixed spring 260, movable spring 270, second fixed spring 280), an electromagnet 207, an armature 208, and a card 209 as a movable member. Each of the plurality of springs is a metal plate-shaped spring member. The card 209 is, for example, a molded part made of resin.

[0046] The first fixed spring 260 has a terminal 261 and a first fixed contact 262 (see Figure 26). The movable spring 270 has a terminal 271 and a movable contact 272. The second fixed spring 280 has a terminal 281 and a second fixed contact 282. The electromagnet 207 includes a coil assembly 227, an iron core 228, a yoke 229, and terminals 207a and 207b.

[0047] In the electromagnetic relay 200, the electromagnet 207 is excited by applying a voltage to terminals 207a and 207b, causing the abutment 208 to swing and be attracted to the iron core 228. Two protrusions 208a and 208b are formed on the upper end of the abutment 208, which engage with the engaging claws 209a and 209b of the card 209. As the abutment 208 swings, the two protrusions 209c and 209d formed on the tip of the card 209 press the holes 270a and 270b formed on both sides of the movable contact 272 of the movable spring 270 toward the second fixed spring 280. As a result, the movable contact 272 separates from the first fixed contact 262 and comes into contact with the second fixed contact 282. Furthermore, a hinge spring (not shown) is attached to the axle 208 and the yoke 229, elastically biasing the axle 208 away from the iron core 228.

[0048] When the voltage applied to the coil is stopped, the axle 208 returns to its original position away from the iron core 228 due to the biasing force of the hinge spring. As the axle 208 returns to its original position, the pressing force from the card 209 to the movable spring 270 is released, and the movable contact 272 moves away from the second fixed contact 282 and makes contact with the first fixed contact 262 again.

[0049] With the above configuration, the electromagnetic relay 200 opens and closes the first fixed contact 262 and the movable contact 272 as break contacts, and also opens and closes the second fixed contact 282 and the movable contact 272 as make contacts. Note that the configuration of the electromagnetic relay 200 is illustrative, and other types of moving mechanisms or moving members that press the movable spring 270 in conjunction with the operation of the electromagnet 207 may be used. The number of springs implemented in the electromagnetic relay 200 is also illustrative, and for example, the number of springs may be two, consisting of a movable spring and a fixed spring.

[0050] Figures 19 and 20 are perspective and front views, respectively, of the movable spring 270. As shown in Figures 19 and 20, the movable spring 270 has a flat base portion 273 supported by a base 204, a terminal 271 extending downward from one lateral end of the base portion 273, and a main spring portion 274 that curves in a U-shape from the center of the lower end of the base portion 273 so as to be convex downward and extends upward, with a movable contact 272 at its upper end. An extension portion 275 is formed that extends linearly from the portion of the upper end of the main spring portion 274 to which the movable contact 272 is attached, toward the position pressed by the projection 209c, and has a hole 270a formed at its tip. Furthermore, between the movable contact 272 and the base 273 of the main spring portion 274, on the side opposite to the extension portion 275 with respect to the movable contact 272, a branch portion 276 is formed that branches off from the main spring portion 274, extends to approximately the same height as the upper end of the main spring portion 274, and has a hole 270b formed at its tip. A slit 278 is formed between the branch portion 276 and the part of the main spring portion 274 to which the movable contact 272 is attached.

[0051] As described above, by shaping the upper end of the movable spring 270 so that a slit 278 is formed at one end of the movable contact 272, when the upper end of the movable spring 270 is pushed toward the second fixed spring 280 by the card 209, it becomes possible to add lateral movement in addition to vertical sliding in the contact path between the movable contact 272 and the second fixed contact 282, thereby adding rolling to the contact operation of the contacts. The effect of forming the slit 278 will be explained in more detail with reference to Figures 21A-21C and Figure 22.

[0052] Figure 21A is a side view showing the state in which the movable spring 270 is pushed toward the second fixed spring 280 by the card 209 and the movable contact 272 begins to contact the second fixed contact 282. Figure 21B shows the state in which the movable spring 270 is completely pushed in by the card 209 from the state in Figure 21A. Figure 21C is a view of Figure 21B from above. In Figure 21C, the portion of the main spring 274 where the movable contact 272 is provided receives a pressing force from the second fixed contact 282 toward the first fixed spring 260. At this time, since a slit 278 is formed on the hole 270b side of the upper end portion of the movable spring 270, the portion of the main spring 274 where the movable contact 272 is provided twists so that the side with the slit 278 is provided leans slightly toward the first fixed spring 260. As a result, as shown in Figure 21C, the portion of the main spring 274 where the movable contact 272 is provided is inclined by an angle θ toward the card 209 with respect to the direction perpendicular to the direction of movement of the card 209.

[0053] In this way, when the movable contact 272 and the second fixed contact 282 make contact, a lateral movement (a direction perpendicular to the direction of movement and vertical direction of the card 209) is applied between the movable contact 272 and the second fixed contact 282, thereby adding a rolling motion. Figure 22 shows an example of the contact path C1 of the second fixed contact 282 on the movable contact 272 when a rolling motion is applied to the contact operation between the movable contact 272 and the second fixed contact 282.

[0054] In this embodiment, by forming a slit 278 at the upper end of the movable spring 270, the stiffness of the movable spring 270 can be reduced without adopting a design that would be critical in terms of current capacity, such as reducing the spring width or thinning the spring thickness. In this embodiment, by providing a slit 278 only on one side of the movable contact 272 at the upper end portion of the movable spring 270, it is possible to incorporate a lateral rolling motion into the contact contact operation of the vertical sliding motion. This allows for a contact cleaning effect that destroys the oxide film on the contact surface and scrapes off worn particles, as well as the benefit of rolling, which is improved resistance to welding during contact. If the movable spring does not have a slit, the contacts slide against each other in the vertical direction, so if irregularities occur on the vertical sliding path, the contacts will be 100% affected. On the other hand, as in this embodiment, if a slit 278 is provided only on one side of the movable contact 272 of the movable spring 270, the upper end portion of the movable spring 270 twists in the direction of the slit 278 when the contacts come into contact with each other. Therefore, the effects of unevenness occurring on the contact surface due to sliding can be dispersed laterally by the twisting motion of the movable spring 270 and avoided.

[0055] (Movable spring U-shape) Figure 23 is a perspective view showing the base 204 with the movable spring 270 mounted, with the front portion cut off. The movable spring 270 is supported by the base 204 with its position restricted at the base portion 273, and is bonded at the portion of the terminal 271 that is inserted through the insertion hole 244 (see Figure 24) of the base 204. The main spring portion 274 of the movable spring 270 is formed to curve upward in a U-shape from the lower end of the base portion 273.

[0056] As shown in Figure 23, forming the main spring portion 274 in a U-shape makes it easy to mount the movable spring 270 longitudinally to the base 204. Furthermore, by forming the elastic deformation region of the movable spring 270 as the main spring portion 274 which is curved in a U-shape, the gap between the base portion 273 of the main spring portion 274 and the base 204 can be increased, preventing adhesive from flowing from the insertion hole 244 (see Figure 24) to the rigid point of the main spring portion 274, thereby preventing variations in stiffness. In addition, compared to the case where the main spring portion is L-shaped, a longer length can be secured for the spring to function, thereby improving the spring properties.

[0057] (Adhesive flow suppression shape) Figure 24 is a perspective view of the portion of the base 204 on which the first fixed spring 260, the movable spring 270, and the second fixed spring 280 are mounted. Figure 25 is a perspective view of the base 204 with the first fixed spring 260 mounted. Figure 26 is a cross-sectional view taken along line XXVI-XXVI of Figure 25. The first fixed spring 260 has a terminal 261, a base portion 263 supported by the base 204, and a spring portion 264 extending from the base portion 263 and having a first fixed contact 262 on its tip end.

[0058] As shown in Figure 24, the bottom surface of the base 204 has a first support portion 241 and a second support portion 242 that support the base portion 263 of the first fixed spring. The first support portion 241 has reference surfaces 241a and 241b that define the position of the base portion 263 in the direction of movement of the card 209. The second support portion 242 has reference surfaces 242a and 242b that define the position of the base portion 263 in the direction of movement of the card 209. The bottom wall of the base 204 has an insertion hole 243 for inserting the terminal 261 of the first fixed spring 260. The first fixed spring 260 is mounted on the base 204 from above so that the base portion 263 of the first fixed spring 260 is supported by the first support portion 241 and the second support portion 242 and the terminal 261 passes through the insertion hole 243 (see Figure 25). With the first fixing spring 260 assembled to the base 204, the terminal 261 is fixed to the base 204 by pouring adhesive from the outside of the insertion hole 243.

[0059] As shown in Figure 24, the area of ​​the base 204 where the terminal 261 is placed has a recess R1 formed by the outer surface 351 on the insertion hole 243 side of the second support portion 242, the side wall surface 352, the wall surface 353 on the movable spring 270 side, and the wall surface 354 on the electromagnet 207 side, with the insertion hole 243 formed at the bottom of the recess R1. The recess R1 suppresses the flow of adhesive from the outside into the terminal insertion area due to surface tension.

[0060] As shown in Figure 26, the terminal 261 has a crank-shaped bend. Specifically, the terminal 261 has a first portion 261a extending downward from the base 263, a second portion 261b bending from the lower end of the first portion 261a and extending diagonally downward, and a third portion 261c bending downward from the tip of the second portion 261b. The gap G between the surface 261f of the second portion 261b on the bottom surface 204a side of the base 204 and the bottom surface 204a is tapered, meaning it widens from the opening end 243a on the internal space side of the insertion hole 243 toward the internal space of the electromagnetic relay 200, in the cross-sectional view of Figure 26.

[0061] In this way, by forming a gap G that gradually widens from the opening end of the insertion hole 243 toward the interior space, the adhesive poured into the insertion hole 243 from the external space side can be retained near the insertion hole 243 by surface tension, and its flow into the interior space can be suppressed.

[0062] As shown in Figure 24, a through hole 244 for inserting the terminal 271 is formed in the bottom wall of the base 204. Figure 27 is a cross-sectional view of the base 204 with the movable spring 270 mounted, taken along line XXVII-XXVII of Figure 24. As shown in Figure 27, in the space of the base 204 where the terminal 271 is located, a recess R2 is defined by the wall surfaces 361 and 362 located on both sides of the card 209 in the direction of movement relative to the terminal 271, the front wall surface 363 in Figure 24, and the circumferential surface of the locking projection 364. The recess R2 has a width W2 that is larger than the width W1 of the opening end of the through hole 244 on the internal space side. By forming a recess R2 that is larger than the opening end of the through hole 244 on the internal space side of the portion where the through hole 244 is located, the adhesive poured into the through hole 244 from the outside can be retained inside the through hole 244 by surface tension and prevented from flowing into the internal space.

[0063] As shown in Figure 24, in the region of the insertion hole 245 into which the terminal 281 of the second movable spring 280 of the base 24 is inserted, a recess R3 with a spatial size larger than the width WX in the short side direction and the width WY in the long side direction of the rectangular through hole 245 is defined by the inner surfaces 371, 372 of the base 204 and the side surface 311b of the restricting portion 311 on the through hole 245 side. The formation of such a recess R3 allows adhesive poured into the insertion hole 245 from the outside to be retained inside the insertion hole 245 by surface tension, preventing it from flowing into the internal space.

[0064] (Spring recoil suppression shape) Figure 28 is a perspective view showing the initial state of the first fixed spring 260, the movable spring 270, and the second fixed spring 280 mounted on the base 204 when no pressing force from the card 209 is acting on them. Figure 29 is a front view of the second fixed spring 280 as seen from the right side of Figure 28. The second fixed spring 280 has a terminal 281 inserted through an insertion hole 245 formed in the base 204, a base portion 283 supported by the base 204, and a spring portion 284. The base 204 is formed so as to be erected from the inside of the bottom wall, having a regulating portion 311a that contacts the card 209 side surface of the spring portion 284 in the initial state shown in Figure 28. When the electromagnet 207 is activated and the second fixed spring 280 is pushed in by the movable spring 270, and then the excitation of the electromagnet is turned off and the card 209 returns to its initial position, the force with which the card 209 pushes in the second fixed spring 280 is lost, and as a reaction, the second fixed spring 280 springs back forcefully towards the card 209, causing it to tilt towards the movable contact 272 side rather than its initial position. The restricting unit 311 restricts the movement of the second fixed spring 280 as it returns to its initial state from a state where the second fixed contact 282 is pushed into the movable contact 272 and the second fixed spring 280 is bent in the opposite direction to the card 209 side, causing it to tilt towards the card 209 side as a reaction.

[0065] On the base 204, on the side opposite the regulating portion 311 with respect to the base portion 283, regulating portions 321 and 322 are formed that contact the two protrusions 283a and 283b of the base portion 283, respectively, to regulate the position of the base portion 283 (see Figure 24). With this configuration, when the second fixed spring 280 is pushed in by the movable spring 270, the second fixed spring 280 elastically deforms so that the entire spring portion 284 tilts toward the opposite side of the card 209, with the boundary position P0 between the spring portion 284 and the base portion 283 (see Figure 29) as the pivot point.

[0066] The reference surface 311a contacts the spring portion 284 up to a position P1, which is higher than the boundary position P0 in the spring portion 284, in terms of its height. That is, the height of the restricting portion on the movable spring 270 side relative to the second fixed spring 280 is higher than the height of the restricting portion on the opposite side. In Figure 29, the contact region 280s where the second fixed spring 280 and the restricting portion 311 contact is shown by a dashed diagonal line. With this configuration, when the second fixed spring 280 falls toward the card 209 side due to the reaction of being pushed by the movable spring 270, the pivot point rises from position P0 to position P1, and the elastic deformation region of the spring portion 284 is shortened, thereby increasing the stiffness of the second fixed spring 280. As a result, it is possible to suppress the second fixed spring 280 from falling too far toward the movable contact 272 side from its initial position, and the effect of arc caused by the momentary closing of the contact gap between the movable contact 272 and the second fixed contact 282 can be reduced.

[0067] Although various embodiments have been described herein, it should be noted that the present invention is not limited to the embodiments described above, and various modifications can be made within the scope of the claims. [Explanation of Symbols]

[0068] 1. 200 Electromagnetic relay; 2. 204 Base; 3. 206 Cover; 4 Spring; 5. 260 First fixed spring; 6. 270 Movable spring; 7. 280 Second fixed spring; 8. 207 Electromagnet; 9 Hinge spring; 10. 208 Affix; 11. 209 Card; 12. 262 First fixed contact; 13. 272 ​​Movable contact; 14. 282 Second fixed contact; 15. 264, 284 Spring section; 16. 207a, 207b, 261, 271, 281 Terminals; 21. 227 Coil assembly; 22. 228 Iron core; 23. 229 Yoke; 24 Coil terminal; 25 Coil; 26 Bobbin; 27, 311a Reference surface; 28 Raised portion; 28a Base; 29 Locking portion; 30 Press-fit surface; 31 Locking portion; 32 Base; 40 Inner surface; 41 Outer surface; 42 Adhesive layer; 43 Step; 44 Cover edge; 45 Mid-side; 46 Recess; 47 Projection; 50 Adhesive layer; 51 Through hole; 52 Inner surface; 54 Notch; 209a, 209b Engaging claws; 208a, 208b Projection; 209c, 209d Projection; 243, 244, 245 Through hole; 270a, 270b Hole; 274 Main spring portion; 278 Slit; 263, 273, 283 Base; 311, 321, 322; Regulating part; G; Gap; R1, R2; Recess

Claims

[Claim 1] Electromagnets and, Multiple springs equipped with contacts and terminals that open and close in accordance with the operation of the electromagnet, The system comprises a base that supports the aforementioned spring, At least one of the plurality of springs has a terminal inserted into the base and a locking portion that protrudes from the terminal in a direction perpendicular to both the opening and closing direction of the contact and the direction in which the terminal is inserted into the base, The base has a reference surface and a locking portion protruding from the reference surface, The locking portion elastically deforms in the opening and closing direction of the contact when the terminal is inserted into the base, The aforementioned locking portion fixes the end of the locked portion on the side opposite to the insertion direction of the terminal relative to the base, thereby restricting the movement of the spring in the insertion direction, in an electromagnetic relay.

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