electromagnetic relay

Abstract

To provide an electromagnetic relay capable of inexpensively fixing a contact case.SOLUTION: An electromagnetic relay includes a fixing terminal, a movable contact piece, a contact case, and a driving device. The fixing terminal includes a fixing contact. The movable contact piece includes a movable contact facing the fixing contact. The contact case accommodates the fixing contact and the movable contact piece. The driving device includes a fixing core screwed to the contact case, and a yoke sandwiched between the fixing core and the contact case.SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] Conventionally, there is known an electromagnetic relay having a contact case that houses a fixed contact and a movable contact piece (see Patent Document 1). The contact case is fixed to the yoke by means of brazing, welding, or the like. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-163761 Summary of the Invention [Problem to be solved by the invention]

[0004] When the contact case is fixed by brazing, welding or other means, high precision is required and the manufacturing cost increases.

[0005] An object of the present invention is to provide an electromagnetic relay in which the contact case can be fixed inexpensively. [Means for solving the problem]

[0006] An electromagnetic relay according to one aspect of the present invention includes a fixed terminal, a movable contact piece, a contact case, and a drive device. The fixed terminal includes a fixed contact. The movable contact piece includes a movable contact facing the fixed contact. The contact case houses the fixed contact and the movable contact piece. The drive device includes a fixed iron core screwed to the contact case and a yoke sandwiched between the fixed iron core and the contact case.

[0007] In this electromagnetic relay, the contact case is fixed to the fixed core by screw fastening, so fixing the contact case can be done more cheaply than when the contact case is fixed by means of brazing, welding, etc. The contact case can be fixed in a simple manner, which improves the production efficiency of electromagnetic relays. Also, high component precision is not required compared to when the contact case is fixed by means of welding, etc. The yoke is sandwiched between the fixed core and the contact case, so the contact case can be fixed to the yoke in a simple manner.

[0008] The drive device may further include a bottomed cylinder that accommodates a portion of the fixed core. The bottomed cylinder may be sandwiched between the fixed core and the yoke. In this case, the bottomed cylinder can be fixed with a simple configuration.

[0009] The electromagnetic relay may further include an elastic member disposed between the yoke and the contact case. In this case, the elastic member can prevent the screws from loosening and can reduce the operating noise of the electromagnetic relay.

[0010] The fixed core may include a large diameter portion, a small diameter portion smaller than the large diameter portion, and a male thread portion formed on the outer circumferential surface of the small diameter portion. The contact case may include a female thread portion that is threadably coupled to the male thread portion. In this case, the fixed core can be directly fastened to the contact case by screws.

[0011] The electromagnetic relay may further include a reinforcing member. The reinforcing member may be disposed between the male thread portion of the fixed core and the female thread portion of the contact case to reinforce the female thread portion of the contact case. In this case, the strength of the female thread portion can be increased.

[0012] The electromagnetic relay may further include a screw member that is screw-coupled to the fixed iron core. The contact case may be screw-fastened to the fixed iron core via the screw member. The contact case may be sandwiched between the fixed iron core and the screw member. In this case, for example, the contact case can be screw-fastened to the fixed iron core using a nut.

[0013] The contact case may be prevented from rotating by the yoke. In this case, the yoke can prevent the contact case from shifting when the contact case and the fixed core are fastened together with screws.

[0014] The yoke may include a plurality of protrusions for preventing the contact case from rotating. In this case, the contact case can be prevented from rotating with a simple structure.

[0015] The contact case may include a locking recess that is locked onto the plurality of protrusions. In this case, the contact case can be prevented from rotating with a simple structure.

[0016] The plurality of protrusions may penetrate the contact case, in which case the yoke can further prevent the contact case from shifting out of position.

[0017] The contact case may include a rotation prevention portion that is prevented from rotating on the side of the yoke. In this case, the contact case can be prevented from rotating with a simple structure.

[0018] According to the present invention, it is possible to provide an electromagnetic relay in which the contact case can be fixed at low cost. [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 2 is a cross-sectional schematic diagram of an electromagnetic relay. [Figure 2] FIG. 2 is a cross-sectional schematic view of the periphery of a fixed core. [Figure 3] FIG. [Figure 4] FIG. 10 is a cross-sectional schematic view of the periphery of a fixed core according to a modified example. [Figure 5] FIG. 10 is a cross-sectional schematic view of the periphery of a fixed core according to a modified example. [Figure 6] FIG. 10 is a cross-sectional schematic view of the periphery of a fixed core according to a modified example. [Figure 7] FIG. 10 is a cross-sectional schematic view of the periphery of a fixed core according to a modified example. [Figure 8] FIG. 10 is a cross-sectional schematic view of the periphery of a fixed core according to a modified example. [Figure 9]FIG. 10 is a cross-sectional schematic view of the periphery of a fixed core according to a modified example. [Figure 10] FIG. 10 is a cross-sectional schematic view of the periphery of a fixed core according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0020] An embodiment of an electromagnetic relay 100 according to one aspect of the present invention will be described below with reference to the drawings. Note that, for ease of understanding, when referring to the drawings, the upper side in FIG. 1 will be referred to as "upper," the lower side as "lower," the left side as "left," and the right side as "right." Furthermore, the direction perpendicular to the plane of the paper on which FIG. 1 is drawn will be referred to as the front-to-rear direction. These directions are defined for the sake of convenience of description and do not limit the arrangement direction of the electromagnetic relay 100.

[0021] 1 is a schematic cross-sectional view of an electromagnetic relay 100. As shown in FIG.

[0022] The contact case 2 is in the shape of a substantially rectangular box and is made of an insulating material such as resin, etc. The contact case 2 may also be made of metal.

[0023] The contact case 2 includes a top surface 2a, side walls 2b, a bottom surface 2c, a through hole 2d (see FIG. 2), and a female thread portion 2e (see FIG. 2). The top surface 2a is rectangular when viewed from above. The side walls 2b extend downward from the front, rear, left, and right ends of the top surface 2a. The bottom surface 2c is rectangular when viewed from above and faces the top surface 2a in the vertical direction. The bottom surface 2c is located below the top surface 2a and is connected to the side walls 2b. The through hole 2d is formed by passing through the center of the bottom surface 2c in the vertical direction. The female thread portion 2e is formed on the inner circumferential surface of the through hole 2d.

[0024] The contact device 3 includes a first fixed terminal 6 , a second fixed terminal 7 , a movable contact piece 10 , and a movable mechanism 11 .

[0025] The first fixed terminal 6 and the second fixed terminal 7 are plate-shaped terminals that extend in the left-right direction. The first fixed terminal 6 and the second fixed terminal 7 are arranged at a distance from each other in the left-right direction. The first fixed terminal 6 and the second fixed terminal 7 are made of a conductive material such as copper.

[0026] The first fixed terminal 6 includes a first fixed contact 6a and a first external connection portion 6b. The first fixed contact 6a is housed in the contact case 2. The first fixed contact 6a is arranged on the lower surface of the first fixed terminal 6 within the contact case 2. The first fixed contact 6a may be integral with the first fixed terminal 6. The first external connection portion 6b protrudes leftward from a side wall 2b of the contact case 2.

[0027] The second fixed terminal 7 includes a second fixed contact 7a and a second external connection portion 7b. The second fixed contact 7a is housed in the contact case 2. The second fixed contact 7a is arranged on the lower surface of the second fixed terminal 7 within the contact case 2. The second fixed contact 7a may be integral with the second fixed terminal 7. The second external connection portion 7b protrudes rightward from the side wall 2b of the contact case 2.

[0028] The movable contact piece 10 is a plate-like member that is long in one direction and is made of a conductive material such as copper. The movable contact piece 10 is housed in a contact case 2. The dimension of the movable contact piece 10 in the left-right direction is greater than the dimension of the movable contact piece 10 in the front-rear direction.

[0029] The movable contact piece 10 includes a first movable contact 10a and a second movable contact 10b. The first movable contact 10a is disposed opposite the first fixed contact 6a and is capable of contacting the first fixed contact 6a. The second movable contact 10b is spaced apart from the first movable contact 10a in the left-right direction. The second movable contact 10b is disposed opposite the second fixed contact 7a and is capable of contacting the second fixed contact 7a. The first movable contact 10a and the second movable contact 10b may be integral with the movable contact piece 10.

[0030] The movable contact piece 10 is provided so as to be movable in a direction (here, upward) in which the first movable contact 10a contacts the first fixed contact 6a, and in a direction (here, downward) in which the first movable contact 10a separates from the first fixed contact 6a.

[0031] The movable mechanism 11 includes a drive shaft 21, a first holding member 22, a second holding member 23, and a contact spring 24. The drive shaft 21 is connected to the movable contact piece 10. The drive shaft 21 extends in the vertical direction and penetrates the movable contact piece 10 in the vertical direction. The drive shaft 21 is provided so as to be movable in the vertical direction.

[0032] The first holding member 22 is fixed to the drive shaft 21 above the movable contact piece 10. The second holding member 23 is fixed to the drive shaft 21 below the movable contact piece 10. The contact spring 24 is disposed between the movable contact piece 10 and the second holding member 23. The contact spring 24 urges the movable contact piece 10 upward via the second holding member 23.

[0033] The drive device 4 is disposed below the contact device 3. The drive device 4 moves the movable contact piece 10 via the drive shaft 21 of the movable mechanism 11 by electromagnetic force. The drive device 4 includes a coil 31, a spool 32, a movable core 33, a fixed core 34, a first yoke 35, a second yoke 36, and a return spring 37.

[0034] When a voltage is applied to the coil 31 and it is excited, it generates an electromagnetic force that moves the movable iron core 33 upward. The spool 32 has a cylindrical shape, and the coil 31 is wound around the outer periphery thereof. The movable iron core 33 is disposed inside the spool 32. The movable iron core 33 is connected to the drive shaft 21 so as to be movable integrally therewith.

[0035] The fixed core 34 is disposed in a position facing the movable core 33. The fixed core 34 is disposed above the movable core 33. The fixed core 34 is fastened to the contact case 2 with screws. The drive shaft 21 passes through the fixed core 34 in the vertical direction. The drive shaft 21 is movable in the vertical direction relative to the fixed core 34.

[0036] As shown in FIG. 2, the fixed core 34 includes a large diameter portion 34a, a small diameter portion 34b, a male thread portion 34c, and a through hole 34d. The large diameter portion 34a is disposed inside the spool 32. The large diameter portion 34a is in contact with the first yoke 35 in the up-down direction. The small diameter portion 34b protrudes upward from an upper portion of the large diameter portion 34a. The outer diameter of the small diameter portion 34b is smaller than the outer diameter of the large diameter portion 34a. In other words, the dimension of the small diameter portion 34b in the left-right direction is smaller than the dimension of the large diameter portion 34a in the left-right direction. The small diameter portion 34b is disposed so as to pass through the first yoke 35 and the through hole 2d of the contact case 2 in the up-down direction.

[0037] The male thread portion 34c is formed on the outer peripheral surface of the tip of the small diameter portion 34b. The male thread portion 34c is threadedly coupled to the female thread portion 2e of the contact case 2. As a result, the contact case 2 is fixed to the fixed iron core 34 by screw fastening. The through hole 34d is formed so as to pass through the centers of the large diameter portion 34a and the small diameter portion 34b in the vertical direction. The drive shaft 21 is passed through the through hole 34d.

[0038] The first yoke 35 has a rectangular shape when viewed from above, and is disposed between the contact case 2 and the spool 32. The first yoke 35 covers the coil 31 from above. The upper surface of the first yoke 35 is in contact with the lower surface of the bottom 2c of the contact case 2. The first yoke 35 is sandwiched between the contact case 2 and the fixed iron core 34. In detail, the first yoke 35 is sandwiched between the fixed iron core 34 and the contact case 2 from above and below by the fastening force generated by the screws fastening the contact case 2 and the fixed iron core 34 together.

[0039] The first yoke 35 includes a through hole 35a formed to penetrate in the vertical direction. The through hole 35a is positioned so as to overlap in the vertical direction with the through hole 2d of the contact case 2, and the small diameter portion 34b of the fixed core 34 passes through the through hole 35a. The through hole 35a has an inner diameter smaller than the outer diameter of the large diameter portion 34a of the fixed core 34. It is preferable that the gap between the through hole 35a and the small diameter portion 34b is small.

[0040] 1, the second yoke 36 has a U-shape when viewed from the front-to-rear direction. The second yoke 36 is disposed around the coil 31 and is connected to the first yoke 35. The second yoke 36 covers the coil 31 from the left and right sides and from below.

[0041] The return spring 37 is disposed between the movable iron core 33 and the fixed iron core 34. The return spring 37 biases the movable iron core 33 downward.

[0042] FIG. 3 is a perspective view of the contact case 2. FIG. 4 is a perspective view of the first yoke 35. The contact case 2 is prevented from rotating by the first yoke 35. The rotation of the contact case 2 around the axis of the drive shaft 21 is restricted by the first yoke 35. In detail, the contact case 2 includes a locking recess 2f. The locking recess 2f is formed on the lower surface of the bottom portion 2c. The locking recess 2f has a shape that is recessed from below toward above. The locking recess 2f is rectangular when viewed from below.

[0043] The first yoke 35 includes a plurality of protrusions 35b (four in this example). The plurality of protrusions 35b are provided on the upper surface of the first yoke 35. The plurality of protrusions 35b contact the side surfaces of the locking recesses 2f within the locking recesses 2f, respectively, to prevent the contact case 2 from rotating.

[0044] The operation of the electromagnetic relay 100 is the same as that of the conventional one, and therefore a description thereof will be omitted.

[0045] In the electromagnetic relay 100 configured as described above, the contact case 2 is fixed to the fixed core 34 by screw fastening, so fixing the contact case 2 can be done more inexpensively than when fixing the contact case 2 by means of brazing, welding, etc. Because the contact case 2 can be fixed in a simple manner, the production efficiency of the electromagnetic relay 100 is improved. Also, compared to when fixing the contact case 2 by means of welding, etc., high component precision is not required. Because the first yoke 35 is sandwiched between the fixed core 34 and the contact case 2, the contact case 2 can be fixed to the first yoke 35 in a simple manner.

[0046] The above describes an embodiment of an electromagnetic relay according to one aspect of the present invention, but the present invention is not limited to the above embodiment, and various modifications are possible within the scope of the gist of the invention.

[0047] The shapes of the first fixed terminal 6 and the second fixed terminal 7 may be changed. For example, the first fixed terminal 6 and the second fixed terminal 7 may be cylindrical terminals. The electromagnetic relay 100 may further include a case that covers the contact case 2 from the outside. The contact case 2 may have the side walls 2b and the bottom 2c formed from a single member, and the top surface 2a formed from a separate member from the bottom 2c and the side walls 2b. In this case, the case may also serve as the top surface 2a. The contact case 2 may have the top surface 2a and the side walls 2b formed from a single member, and the bottom 2c formed from a separate member from the top surface 2a and the side walls 2b.

[0048] The configuration of the drive unit 4 may be changed. For example, the first yoke 35 and the second yoke 36 may be arranged upside down. In this case, the second yoke 36 is sandwiched between the fixed core 34 and the contact case 2 by fastening the contact case 2 and the fixed core 34 with screws.

[0049] As shown in FIG. 5, the drive unit 4 may further include a bottomed cylindrical body 38. The bottomed cylindrical body 38 is disposed inside the spool 32 and houses the movable iron core 33 and the large diameter portion 34a of the fixed iron core 34. The bottomed cylindrical body 38 is sandwiched and fixed between the first yoke 35 and the fixed iron core 34 by screwing the contact case 2 and the fixed iron core 34 together. Specifically, the bottomed cylindrical body 38 includes a clamped portion 38a. The clamped portion 38a extends from the upper end of the bottomed cylindrical body 38 toward the small diameter portion 34b of the fixed iron core 34. The clamped portion 38a is clamped between the first yoke 35 and the large diameter portion 34a of the fixed iron core 34 in the vertical direction. Note that the drive shaft 21 and the return spring 37 are not shown in FIG. 5 and subsequent figures.

[0050] 6, the electromagnetic relay 100 may further include an elastic member 40. The elastic member 40 is disposed between the first yoke 35 and the bottom portion 2c of the contact case 2. The elastic member 40 is an elastically deformable cushioning material such as rubber.

[0051] 7, the electromagnetic relay 100 may further include a reinforcing member 42. The reinforcing member 42 is disposed between the male thread portion 34c of the fixed core 34 and the female thread portion 2e of the contact case 2, and reinforces the female thread portion 2e of the contact case 2. The reinforcing member 42 is, for example, a helical insert. The female thread portion 2e of the contact case 2 may be formed by fitting a helical insert into the through hole 2d.

[0052] As shown in Fig. 8, the contact case 2 may be fastened to the fixed core 34 by a screw member 44 that screws into the male thread portion 34c of the fixed core 34. The screw member 44 is, for example, a nut with an internal thread. In this case, the contact case 2 is sandwiched between the fixed core 34 and the screw member 44. The screw member 44 may be fitted into the bottom portion 2c of the contact case 2. For example, the screw member 44 with an internal thread may be insert-molded into the contact case 2.

[0053] In the above embodiment, the plurality of protrusions 35b are brought into contact with the side surfaces of the locking recesses 2f to prevent rotation of the contact case 2, but the structure for preventing rotation of the contact case 2 is not limited to the above embodiment. For example, a configuration corresponding to the plurality of protrusions 35b may be provided on the contact case 2, and a configuration corresponding to the locking recesses 2f may be provided on the first yoke 35.

[0054] 9, the multiple protrusions 35b may penetrate from the bottom 2c of the contact case 2 to prevent rotation of the contact case 2. Note that the multiple protrusions 35b do not necessarily have to penetrate the bottom 2c of the contact case 2. The multiple protrusions 35b may have a shape that engages with the bottom 2c of the contact case 2 to prevent rotation of the contact case 2.

[0055] As shown in Fig. 10, the contact case 2 may include anti-rotation portions 2g that are prevented from rotating on the side portions of the first yoke 35. The anti-rotation portions 2g are arranged on the outer sides of the side portions of the first yoke 35. In the example shown in Fig. 10, a pair of anti-rotation portions 2g are provided on the left and right.

[0056] An adhesive may be applied between the male thread portion 34c of the fixed core 34 and the female thread portion 2e of the contact case 2. Similarly, an adhesive may be applied between the first yoke 35 and the fixed core 34.

[0057] In the above embodiment, the contact case 2 includes the female thread portion 2e and the fixed core 34 includes the male thread portion 34c, but the configurations of the female thread portion 2e and the male thread portion 34c may be interchanged. That is, the contact case 2 may be provided with a male thread portion and the fixed core 34 may be provided with a female thread portion. In this case, for example, a cylindrical portion connected to the through hole 2d of the contact case 2 may be made to protrude downward from the bottom portion 2c of the contact case 2, and a male thread may be provided on the outer peripheral surface of the cylindrical portion. [Explanation of symbols]

[0058] 2 Contact Case 2e Female thread 2f Locking recess 2g Anti-rotation part 4. Drive unit 6 First fixed terminal (an example of a fixed terminal) 6a First fixed contact (an example of a fixed contact) 10 Movable contact piece 10a First moving contact (an example of a moving contact) 34 Fixed core 34a Large diameter section 34b Small diameter section 34c male thread 35 First yoke (example of a yoke) 35b Multiple protrusions 38 Bottomed cylinder 40 Elastic member 42 Reinforcement member 100 Electromagnetic relay

Claims

1. a fixed terminal including a fixed contact; a movable contact piece including a movable contact facing the fixed contact; a contact case that accommodates the fixed contact and the movable contact piece; a drive device including a fixed core that is screwed to the contact case, and a yoke that is sandwiched between the fixed core and the contact case; Equipped with Electromagnetic relay.

2. the drive device further includes a bottomed cylinder that accommodates a portion of the fixed core, The bottomed cylindrical body is sandwiched between the fixed core and the yoke.

2. The electromagnetic relay according to claim 1.

3. further comprising an elastic member disposed between the yoke and the contact case.

3. An electromagnetic relay according to claim 1 or 2.

4. the fixed core includes a large diameter portion, a small diameter portion having a diameter smaller than that of the large diameter portion, and a male thread portion formed on an outer circumferential surface of the small diameter portion, The contact case includes a female thread portion that is threadably coupled to the male thread portion.

4. An electromagnetic relay according to claim 1.

5. The contact case further includes a reinforcing member disposed between the male thread portion of the fixed iron core and the female thread portion of the contact case, the reinforcing member reinforcing the female thread portion of the contact case.

5. An electromagnetic relay according to claim 4.

6. Further, a screw member is provided which is screw-coupled to the fixed iron core, the contact case is screwed to the fixed iron core via the screw member, The contact case is sandwiched between the fixed iron core and the screw member.

5. An electromagnetic relay according to claim 1.

7. The contact case is prevented from rotating by the yoke.

7. An electromagnetic relay according to claim 1.

8. The yoke and the contact case include a plurality of protrusions that prevent the contact case from rotating.

8. An electromagnetic relay according to claim 7.

9. the contact case includes a locking recess that is locked to the plurality of protrusions, 9. The electromagnetic relay according to claim 8.

10. the plurality of protrusions penetrate the contact case; 9. The electromagnetic relay according to claim 8.

11. The contact case includes a rotation prevention portion that is prevented from rotating by a side portion of the yoke.

11. An electromagnetic relay according to any one of claims 7 to 10.

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