Electromagnetic relay

Abstract

The electromagnetic relay of the present invention comprises a fixed contact, a movable contact piece, a drive shaft and a movable iron core. The movable contact piece comprises a movable contact arranged opposite to the fixed contact, and is movable in a first direction in contact with the fixed contact and in a second direction away from the fixed contact. The drive shaft extends in a direction along the first direction and the second direction, and is connected to the movable contact piece. The movable iron core is connected to the drive shaft so as to be movable as a whole on the first direction side or the second direction side of the movable contact piece. The drive shaft comprises a first contact portion in contact with the movable contact piece, a second contact portion in contact with the movable iron core, and an insulating portion made of an insulating material and insulating the movable contact piece from the movable iron core.

Description

Technical Field

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

[0002] Electromagnetic relays for opening and closing circuits are well known. For example, the electromagnetic relay described in Patent Document 1 comprises a contact device, an electromagnetic drive device, and a drive shaft. The contact device includes a fixed contact and a movable contact piece. The electromagnetic drive device includes a coil, a fixed iron core, and a movable iron core. The drive shaft is formed of a conductive material such as metal and is connected to the movable contact piece and the movable iron core in a manner that allows for integral movement.

[0003] When voltage is applied to the coil of the electromagnetic drive device, the movable iron core is attracted by the fixed iron core and moves upward together with the drive shaft. As the movable iron core and the drive shaft move, the movable contact piece moves toward the fixed contact point, thereby contacting the fixed contact point.

[0004] Patent Document 1: Japanese Patent Application Laid-Open No. 2014-017086 Summary of the Invention

[0005] If the drive shaft is conductive, insulation between the movable contact piece connected to the drive shaft and the movable iron core must be ensured. To ensure insulation between the movable contact piece and the movable iron core, it is necessary to provide a component for ensuring insulation, or to ensure an insulation distance between the movable contact piece and the movable iron core in the assembly with other components. This may increase the number of components and limit design freedom.

[0006] An object of the present invention is to ensure insulation between a movable contact piece and a movable iron core while suppressing an increase in the number of components.

[0007] (1) An electromagnetic relay according to one embodiment of the present invention comprises a fixed contact, a movable contact piece, a drive shaft and a movable iron core. The movable contact piece includes a movable contact arranged opposite to the fixed contact, and is movable in a first direction in contact with the fixed contact and in a second direction away from the fixed contact. The drive shaft extends in a direction along the first direction and the second direction and is connected to the movable contact piece. The movable iron core is connected to the drive shaft so as to be movable as a whole on the first direction side or the second direction side of the movable contact piece. The drive shaft includes a first contact portion in contact with the movable contact piece, a second contact portion in contact with the movable iron core, and an insulating portion made of an insulating material and insulating the movable contact piece from the movable iron core.

[0008] In this electromagnetic relay, the insulation between the movable contact piece and the movable iron core can be ensured by using an insulating portion formed from the insulating material of the drive shaft. This eliminates the need for a separate component to ensure insulation between the movable contact piece and the movable iron core, or for ensuring the insulation distance between the movable contact piece and the movable iron core in an assembly with other components. This reduces the number of components and assembly time, while also increasing design freedom.

[0009] (2) It is preferable that at least one of the first contact portion and the second contact portion is covered by the insulating portion. In this case, the number of components and the number of assembly steps can be reduced, and the degree of freedom in design can be increased.

[0010] (3) The drive shaft preferably further includes a metal portion extending in the first direction and the second direction and entirely covered by the insulating portion. In this case, the rigidity of the drive shaft can be increased.

[0011] (4) Preferably, the drive shaft further includes a flange portion formed of metal, and the electromagnetic relay further includes a contact spring that contacts the flange portion of the drive shaft. In this case, compared to a case where the flange portion is formed of an insulating material such as resin, the generation of resin chips due to contact between the flange portion and the contact spring can be prevented.

[0012] (5) The first contact portion and the second contact portion are preferably made of metal, and the insulating portion is disposed between the first contact portion and the second contact portion. In this case, the number of components and the number of assembly steps can be reduced, and the degree of freedom in design can be increased.

[0013] (6) It is preferable that a contact housing for housing the movable contact piece is further provided. The contact housing includes a through hole through which the drive shaft passes, and a portion of the drive shaft passing through the through hole is covered by an insulating portion.

[0014] According to the present invention, it is possible to ensure insulation between the movable contact piece and the movable iron core while suppressing an increase in the number of components. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a cross-sectional view of an electromagnetic relay according to one embodiment of the present invention.

[0016] Figure 2 This is an enlarged cross-sectional view of the contact device and its surroundings.

[0017] Figure 3 This is a cross-sectional view of an electromagnetic relay when voltage is applied to the coil.

[0018] Figure 4 It is an enlarged cross-sectional view of the periphery of a contact device according to another embodiment.

[0019] Figure 5It is an enlarged cross-sectional view of the periphery of a contact device according to another embodiment.

[0020] Figure 6 It is an enlarged cross-sectional view of the periphery of a contact device according to another embodiment.

[0021] Figure 7 It is an enlarged cross-sectional view of the periphery of a contact device according to another embodiment.

[0022] Figure 8 It is an enlarged cross-sectional view of the periphery of a contact device according to another embodiment. DETAILED DESCRIPTION

[0023] Hereinafter, an embodiment of an electromagnetic relay according to one aspect of the present invention will be described with reference to the drawings. Figure 1 1 is a cross-sectional view of the electromagnetic relay 100. Figure 1 As shown in FIG. 1 , the electromagnetic relay 100 includes a housing 2, a contact device 3, a drive shaft 4, and an electromagnetic drive device 5. In the following description, the direction in which the axis Ax of the drive shaft 4 extends is referred to as the "axial direction." In addition, when referring to the drawings, the direction in which the axis Ax of the drive shaft 4 extends is referred to as the "axial direction" for ease of understanding. Figure 1 The description will be given by setting the upper side in as “up”, the lower side as “down”, the left side as “left”, and the right side as “right”.

[0024] Housing 2 consists of a shell 2a and a cover 2b. Shell 2a is a roughly rectangular box with an open top. Cover 2b covers the top of shell 2a. Shell 2a and cover 2b are made of insulating material. Housing 2 houses contact device 3, drive shaft 4, and electromagnetic drive device 5.

[0025] A contact housing 11 housing the contact device 3 and a contact cover 12 covering the upper portion of the contact housing 11 are arranged in the housing 2. The contact housing 11 and the contact cover 12 are formed of an insulating material.

[0026] The contact housing 11 includes a bottom 11a, a cylindrical portion 11b, a first contact support portion 11c, and a second contact support portion 11d. The bottom 11a is formed in a rectangular plate shape. The length direction of the bottom 11a is the same as that of the bottom 11a. Figure 1 The left and right directions are consistent.

[0027] The barrel portion 11b extends axially in a cylindrical shape. It protrudes downward from the center of the bottom portion 11a and also protrudes upward from the center of the bottom portion 11a. The barrel portion 11b includes a through-hole 18 that axially extends through the bottom portion 11a. The through-hole 18 axially extends through the center of the bottom portion 11a. The through-hole 18 axially extends through the drive shaft 4. The barrel portion 11b does not necessarily need to be cylindrical.

[0028] The first contact support portion 11c is located to the left of the center of the bottom portion 11a in the longitudinal direction. The first contact support portion 11c is formed to protrude upward from the bottom portion 11a in a rectangular shape. The second contact support portion 11d is located to the right of the center of the bottom portion 11a in the longitudinal direction. The second contact support portion 11d is formed to protrude upward from the bottom portion 11a in a rectangular shape.

[0029] The contact cover 12 covers the upper portion of the contact housing 11. The contact cover 12 includes an arc extension wall 12a extending toward the bottom 11a. The arc extension wall 12a is formed of, for example, a resin or a ceramic material such as alumina.

[0030] Figure 2 FIG is an enlarged cross-sectional view of the periphery of the contact device 3. Figure 1 and Figure 2 As shown, the contact device 3 includes a first fixed terminal 14, a second fixed terminal 15, a movable contact piece 16, and a contact piece holding portion 17. The first fixed terminal 14, the second fixed terminal 15, and the movable contact piece 16 are formed of a conductive material.

[0031] The first fixed terminal 14 extends horizontally and is supported by the first contact support portion 11c of the contact housing 11 within the housing 2. The first fixed terminal 14 includes a first fixed contact 14a and a first external connection portion 14b. The first fixed contact 14a is positioned above the first contact support portion 11c within the contact housing 11. The first fixed contact 14a is an example of a fixed contact. The first external connection portion 14b protrudes horizontally from the housing 2a.

[0032] The second fixed terminal 15 extends in the left-right direction and is supported within the housing 2 by the second contact support portion 11d of the contact housing 11. The second fixed terminal 15 includes a second fixed contact 15a and a second external connection portion 15b. The second fixed contact 15a is spaced apart from the first fixed contact 14a in the left-right direction. The second fixed contact 15a is an example of a fixed contact.

[0033] The movable contact piece 16 extends in the left-right direction in the contact housing 11. The movable contact piece 16 is arranged to face the first fixed contact 14a and the second fixed contact 15a. The movable contact piece 16 is arranged above the first fixed contact 14a and the second fixed contact 15a.

[0034] The movable contact piece 16 includes a first movable contact 16a, a second movable contact 16b, and a through-hole 16c. The first movable contact 16a is disposed opposite the first fixed contact 14a and is capable of contacting the first fixed contact 14a. The second movable contact 16b is disposed opposite the second fixed contact 15a and is capable of contacting the second fixed contact 15a. The first movable contact 16a and the second movable contact 16b are examples of movable contacts. The through-hole 16c is an axially extending hole formed at a position that coincides with the axis Ax of the drive shaft 4.

[0035] The movable contact piece 16 is movable in a contact direction Z1 for contacting the first fixed contact 14a and the second fixed contact 15a and a separation direction Z2 for separating from the first fixed contact 14a and the second fixed contact 15a. The contact direction Z1 is an example of a first direction, and the separation direction Z2 is an example of a second direction.

[0036] The contact direction Z1 is the direction in which the first movable contact 16a and the second movable contact 16b contact the first fixed contact 14a and the second fixed contact 15a ( Figure 1 The separation direction Z2 is the direction in which the first movable contact 16a and the second movable contact 16b move away from the first fixed contact 14a and the second fixed contact 15a ( Figure 1 The contact direction Z1 and the separation direction Z2 are consistent with the axial direction.

[0037] like Figure 2 As shown, the contact piece holder 17 holds the movable contact piece 16 via the drive shaft 4. The contact piece holder 17 connects the movable contact piece 16 to the drive shaft 4. The contact piece holder 17 includes a bracket 24 and a contact spring 25. The movable contact piece 16 is axially clamped between the upper portion of the bracket 24 and a flange portion 4d (described later) of the drive shaft 4. The contact spring 25 is compressed and disposed between the bottom portion of the bracket 24 and the flange portion 4d.

[0038] The drive shaft 4 extends in a direction along the contact direction Z1 and the separation direction Z2. A first end 4a of the drive shaft 4, which faces the separation direction Z2, is disposed within the contact housing 11, while a second end 4b of the drive shaft 4, which faces the contact direction Z1, is disposed within the housing 33a of the bobbin 33, described later. The drive shaft 4 is coupled to the movable contact piece 16 via the contact piece retaining portion 17 and is movable in both the contact direction Z1 and the separation direction Z2 along with the movable contact piece 16.

[0039] The drive shaft 4 includes a metal portion 41 and an insulating portion 42 made of an insulating material. The drive shaft 4 is formed by insert molding the insulating portion 42 integrally with the metal portion 41. In this embodiment, the entire metal portion 41 is covered by the insulating portion 42. The metal portion 41 extends in a direction along the contact direction Z1 and the separation direction Z2. The metal portion 41 is rod-shaped and extends from a first end 4a to a second end 4b.

[0040] The insulating portion 42 is made of an insulating material and insulates the movable contact piece 16 from the movable iron core 34. The insulating material is, for example, a thermoplastic resin such as liquid crystal polymer (LCP) or polybutylene terephthalate (PBT) resin, or a thermosetting resin.

[0041] The drive shaft 4 includes a head portion 4c, a flange portion 4d, and a shaft portion 4e. The head portion 4c is disposed at the first end 4a and extends through the through-hole 16c of the movable contact piece 16 from the contact direction Z1 side toward the separation direction Z2 side. The head portion 4c is capable of contacting the through-hole 16c of the movable contact piece 16. The head portion 4c is composed of a metal portion 41 and an insulating portion 42. The head portion 4c is an example of a first contact portion.

[0042] The flange portion 4d is located on the contact direction Z1 side of the head portion 4c. The outer diameter of the flange portion 4d is larger than the diameter of the through-hole 16c of the movable contact piece 16. The surface of the flange portion 4d on the separation direction Z2 side contacts the movable contact piece 16. The surface of the flange portion 4d on the contact direction Z1 side contacts the contact spring 25. The flange portion 4d is formed of an insulating portion 42. The flange portion 4d is an example of a first contact portion.

[0043] The shaft portion 4e extends from the flange portion 4d toward the contact direction Z1. The shaft portion 4e passes through the through-hole 18 of the contact housing 11 and extends into the housing portion 33a of the bobbin 33. Therefore, the portion of the shaft portion 4e that passes through the through-hole 18 is covered by the insulating portion 42. The shaft portion 4e is composed of the metal portion 41 and the insulating portion 42. The shaft portion 4e is an example of a second contact portion.

[0044] The electromagnetic drive device 5 moves the drive shaft 4 in the contact direction Z1 and the separation direction Z2. The electromagnetic drive device 5 is arranged in a space different from the contact device 3 in the housing 2. In this embodiment, the electromagnetic drive device 5 is arranged below the contact housing 11.

[0045] The electromagnetic drive device 5 includes a coil 32 , a bobbin 33 , a movable iron core 34 , a fixed iron core 35 , a biasing member 36 , and a yoke 37 .

[0046] The coil 32 is mounted on the outer periphery of the bobbin 33. The bobbin 33 includes a housing portion 33a. The housing portion 33a is provided on the inner periphery of the bobbin 33. The housing portion 33a is cylindrical and extends in the axial direction.

[0047] The movable iron core 34 is arranged in the storage portion 33a. The movable iron core 34 is cylindrical, and the drive shaft 4 passes through its center in the axial direction. The movable iron core 34 can move axially together with the drive shaft 4. In this embodiment, the movable iron core 34 is connected to the movable contact piece 16 in the contact direction Z1 side so as to be able to move integrally with the drive shaft 4. In detail, as shown in FIG. Figure 2 As shown, the movable iron core 34 is connected to the shaft portion 4e of the drive shaft 4. An insulating portion 42 is interposed between the movable iron core 34 and the metal portion 41 of the drive shaft 4.

[0048] The fixed iron core 35 is disposed in the housing portion 33 a on the contact direction Z1 side of the movable iron core 34 so as to face the movable iron core 34 . The fixed iron core 35 is fixed to the yoke 37 .

[0049] The urging member 36 is, for example, a coil spring and is disposed between the movable iron core 34 and the fixed iron core 35. The urging member 36 urges the movable iron core 34 in the separation direction Z2. Therefore, the urging member 36 is disposed between the movable iron core 34 and the fixed iron core 35 in a compressed state.

[0050] The yoke 37 includes a first yoke 37a and a second yoke 37b. The first yoke 37a is plate-shaped and positioned between the bottom 11a of the contact housing 11 and the bobbin 33. The first yoke 37a overlaps the lower portion of the cylindrical portion 11b in the left-right direction. The first yoke 37a is connected to the annular core 38. The second yoke 37b is roughly U-shaped, with its bottom positioned below the bobbin 33. The upper ends of both sides of the second yoke 37b are connected to the first yoke 37a.

[0051] Next, the operation of electromagnetic relay 100 will be described. Figure 1 This indicates a state where no voltage is applied to coil 32. When no voltage is applied to coil 32, the biasing member 36 prevents the movable iron core 34 from moving in the contact direction Z1. Consequently, the first movable contact 16a and the second movable contact 16b are spaced apart from the first fixed contact 14a and the second fixed contact 15a.

[0052] Figure 3 This shows the state where voltage is applied to coil 32. When voltage is applied to coil 32, causing it to be excited, the electromagnetic force of coil 32 causes movable iron core 34 to overcome the elastic force of biasing member 36 and move in contact direction Z1. As movable iron core 34 moves, drive shaft 4 and movable contact piece 16 move in contact direction Z1, causing first movable contact 16a and second movable contact 16b to contact first fixed contact 14a and second fixed contact 15a.

[0053] When the voltage application to the coil 32 stops, the movable iron core 34 moves in the separation direction Z2 due to the elastic force of the biasing member 36 , so that the first movable contact 16 a and the second movable contact 16 b are separated from the first fixed contact 14 a and the second fixed contact 15 a .

[0054] When the first movable contact 16a and the second movable contact 16b come into contact with the first fixed contact 14a and the second fixed contact 15a, insulation between the movable contact piece 16 and the movable iron core 34 must be ensured. In this embodiment, insulation between the movable contact piece 16 and the movable iron core 34 is ensured by the insulating portion 42 of the drive shaft 4. This eliminates the need for a new component for ensuring insulation or for using a component combined with another component to ensure the insulation distance between the movable contact piece 16 and the movable iron core 34. This reduces the number of components and assembly steps of the electromagnetic relay 100, while increasing design freedom.

[0055] While an embodiment of an electromagnetic relay according to one aspect of the present invention has been described above, the present invention is not limited to the aforementioned embodiment and various modifications can be made without departing from the spirit of the invention. For example, the structure of the electromagnetic drive device 5 may be modified. The shape or arrangement of the movable contact piece 16, coil 32, bobbin 33, movable iron core 34, fixed iron core 35, biasing member 36, or yoke 37 may also be modified. The shape or arrangement of the housing 2, contact case 11, and contact cover 12 may also be modified. For example, the present invention may be applied to a structure in which the movable iron core 34 is arranged on the side of the movable contact piece 16 in the separation direction Z2.

[0056] In the above embodiment, the metal portion 41 is arranged on the drive shaft 4 to improve the rigidity of the drive shaft 4, but it is not necessary to arrange the metal portion 41. Figure 4 As shown, the entire drive shaft 4 may be formed of the insulating portion 42. That is, the drive shaft 4 may be formed only of insulating material.

[0057] In addition, the shape of the metal portion 41 is not limited to the above embodiment. Figures 5 to 7 As shown in FIG. 4 , the axial length or configuration of the metal portion 41 may also be changed. Specifically, as shown in FIG. Figure 5 As shown in FIG. 4 , the metal portion 41 may be arranged from the head portion 4 c to the front side of the movable iron core 34. Figure 6 As shown, the metal portion 41 may be disposed only on the shaft portion 4e of the drive shaft 4. Figure 7 As shown, the metal portion 41 may be arranged from the first end 4 a side of the shaft portion 4 e of the drive shaft 4 to the front side of the movable iron core 34 .

[0058] In the above embodiment, the entire metal portion 41 is covered by the insulating portion 42 , but it is not necessary to cover the entire metal portion 41 . Any structure is sufficient as long as the insulating portion 42 can insulate the movable contact piece 16 from the movable iron core 34 .

[0059] In addition, for example, Figure 8 As shown, metal parts 141a and 141b are arranged at both ends of the drive shaft 4, and an insulating part 42 may be arranged between the metal parts 141a and 141b. The metal parts 141a, 141b and the insulating part 42 are formed integrally by insert molding or press-fitting. In detail, the head 4c and the flange part 4d of the drive shaft 4 are composed of the metal part 141a. The shaft part 4e of the drive shaft 4 is composed of the insulating part 42 and the metal part 141b. The insulating part 42 extends from the flange part 4d to the near front side of the movable iron core 34. The metal part 141b extends from the end of the insulating part 42 on the contact direction Z1 side to the second end 4b, and the movable iron core 34 is connected to the metal part 141b. In this case, the movable iron core 34 can be firmly fixed to the drive shaft 4. Furthermore, compared to the case where the flange portion 4d of the drive shaft 4 is formed of the insulating portion 42, the generation of resin chips due to contact between the contact spring 25 and the flange portion 4d can be prevented.

[0060] According to the present invention, it is possible to ensure insulation between the movable contact piece and the movable iron core while suppressing an increase in the number of components.

[0061] Description of reference numerals:

[0062] 4…driving shaft; 4c…head portion (an example of the first contact portion); 4d…flange portion (an example of the first contact portion); 4e…shaft portion (an example of the second contact portion); 11…contact housing; 14a…first fixed contact (an example of a fixed contact); 15a…second fixed contact (an example of a fixed contact); 16…movable contact piece; 16a…first movable contact (an example of a movable contact); 16b…second movable contact (an example of a movable contact); 18…through hole; 25…contact spring; 34…movable iron core; 41, 141a, 141b…metal portion; 42…insulating portion; 100…electromagnetic relay; Z1…contact direction (an example of the first direction); Z2…separation direction (an example of the second direction).

Claims

1. An electromagnetic relay, characterized in that: have: Fixed contacts; A movable contact piece, comprising a movable contact arranged opposite to the fixed contact, and capable of moving in a first direction of contact with the fixed contact and in a second direction of moving away from the fixed contact; a drive shaft extending in a direction along the first direction and the second direction and connected to the movable contact piece; as well as a movable iron core connected to the driving shaft so as to be movable integrally on the first direction side or the second direction side of the movable contact piece, The drive shaft includes: a first contact portion that contacts the movable contact piece; a second contact portion that contacts the movable iron core; and an insulating portion that is made of an insulating material to insulate the movable contact piece from the movable iron core. The driving shaft further includes a metal portion extending in a direction along the first direction and the second direction and entirely covered by the insulating portion.

2. An electromagnetic relay, characterized in that: have: Fixed contacts; A movable contact piece, comprising a movable contact arranged opposite to the fixed contact, and capable of moving in a first direction of contact with the fixed contact and in a second direction of moving away from the fixed contact; a drive shaft extending in a direction along the first direction and the second direction and connected to the movable contact piece; as well as a movable iron core connected to the driving shaft so as to be movable integrally on the first direction side or the second direction side of the movable contact piece, The drive shaft includes: a first contact portion that contacts the movable contact piece; a second contact portion that contacts the movable iron core; and an insulating portion that is made of an insulating material to insulate the movable contact piece from the movable iron core. The drive shaft further includes a flange portion made of metal, A contact spring that contacts the flange portion of the drive shaft is further provided.

3. An electromagnetic relay, characterized in that: have: Fixed contacts; A movable contact piece, comprising a movable contact arranged opposite to the fixed contact, and capable of moving in a first direction of contact with the fixed contact and in a second direction of moving away from the fixed contact; a drive shaft extending in a direction along the first direction and the second direction and connected to the movable contact piece; as well as a movable iron core connected to the driving shaft so as to be movable integrally on the first direction side or the second direction side of the movable contact piece, The drive shaft includes: a first contact portion that contacts the movable contact piece; a second contact portion that contacts the movable iron core; and an insulating portion that is made of an insulating material to insulate the movable contact piece from the movable iron core. The first contact portion and the second contact portion are made of metal, The insulating portion is disposed between the first contact portion and the second contact portion.

4. The electromagnetic relay according to any one of claims 1 to 3, characterized in that: At least one of the first contact portion and the second contact portion is covered by the insulating portion.

5. The electromagnetic relay according to any one of claims 1 to 3, Also includes a contact housing for accommodating the movable contact piece, The contact housing includes a through hole through which the drive shaft passes. A portion of the drive shaft passing through the through hole is covered by the insulating portion.

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