auxiliary contact unit

Abstract

The present application has a case (21) and a case (31) which are divided in a width direction. The case (21) includes a side wall portion (22) and a partition wall portion (23) which protrudes from a wall surface of the side wall portion (22) toward the case (31). The case (31) includes a side wall portion (32) which abuts against the wall surface of the partition wall portion (23) when the case (21) is assembled. A range surrounded by the side wall portion (22), the partition wall portion (23), and the side wall portion (32) becomes a contact point housing portion (41). The side wall portion (32) includes a staggered wall portion (33) which protrudes from the wall surface toward the side wall portion (22) along the partition wall portion (23).

Description

Technical Field

[0001] This invention relates to an auxiliary contact unit installed in an electromagnetic contactor. Background Technology

[0002] An auxiliary contact unit that can be selectively installed on an electromagnetic contactor can output signals from the auxiliary contacts to an external electronic control circuit in conjunction with the opening and closing of the electromagnetic contactor. As an example, as shown in reference 1, there is a side-opening type that is installed on the side of the electromagnetic contactor body.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2012-038644 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] The side-opening auxiliary contact unit has two configurations: one where the housing is split at the center in the width direction, and the other where it is an integrally formed structure without any split in the width direction. In the configuration where the housing is split at the center in the width direction, dust can enter the interior from the split surface, potentially causing poor contact. Additionally, in the integrally formed structure, there is an insertion hole for inserting a fixed contact, but to allow the fixed contact to pass through, the height of the insertion hole is set to be greater than the thickness of the fixed contact. Therefore, in the integrally formed structure, a gap is also formed between the insertion hole and the fixed contact, allowing dust to enter the interior from this gap, potentially causing poor contact.

[0008] The purpose of this invention is to improve the dustproof performance of the contact storage section in the auxiliary contact unit installed in an electromagnetic contactor.

[0009] Technical solutions for solving the problem

[0010] An auxiliary contact unit of the present invention is mounted on the side of an electromagnetic contactor. The auxiliary contact unit includes a first housing and a second housing divided in a direction orthogonal to the side of the electromagnetic contactor. The first housing includes a first sidewall portion parallel to the side of the electromagnetic contactor and a partition wall portion protruding from the wall of the first sidewall portion toward the second housing. The second housing includes a second sidewall portion parallel to the side of the electromagnetic contactor and whose front end abuts against the wall surface when assembled with the first housing. The area surrounded by the first sidewall portion, the partition wall portion and the second sidewall portion forms a contact receiving portion. The second sidewall portion includes an interlaced wall portion protruding from the wall surface along the partition wall portion toward the first sidewall portion.

[0011] Invention Effects

[0012] According to the present invention, since the partition wall protrudes from the first side wall and the intersecting wall along the partition wall protrudes from the second side wall, dust must pass between the partition wall and the intersecting wall to enter the contact receiving part. That is, the intrusion path to the contact receiving part is lengthened, thereby making it difficult for dust to enter and improving dustproof performance. Attached Figure Description

[0013] Figure 1 This is a diagram showing an electromagnetic contactor and auxiliary contact units.

[0014] Figure 2 This is a diagram showing the disassembled shell.

[0015] Figure 3 It is a diagram showing the components unfolded.

[0016] Figure 4 This diagram shows the state of the fixed contacts assembled.

[0017] Figure 5 This is a diagram showing the cross-section of the auxiliary contact unit.

[0018] Figure 6 It is a diagram showing the intrusion path of dust.

[0019] Figure 7 This is a diagram representing Comparative Example 1.

[0020] Figure 8 This is a diagram representing comparison example 2. Detailed Implementation

[0021] The embodiments of the present invention will now be described with reference to the accompanying drawings. The drawings are merely illustrative and may vary in reality. Furthermore, the following embodiments illustrate apparatus and methods for embodying the technical concept of the present invention, and are not intended to limit the structure to those descriptions. That is, the technical concept of the present invention can be modified in various ways within the scope of the technical limitations described in the invention.

[0022] <One implementation method>

[0023] <Structure>

[0024] In the following description, for convenience, the three mutually orthogonal directions are defined as the longitudinal direction, the width direction, and the depth direction.

[0025] Figure 1 This is a diagram showing an electromagnetic contactor and auxiliary contact units.

[0026] Figure (a) shows the state before the auxiliary contact unit 12 is installed on the electromagnetic contactor 11, and Figure (b) shows the state after the auxiliary contact unit 12 is installed on the side of the electromagnetic contactor 11. Both figures are viewed from the front side in the depth direction, showing the state of the electromagnetic contactor 11 and the auxiliary contact unit 12.

[0027] The electromagnetic contactor 11 opens and closes the main circuit, and the auxiliary contact unit 12, in conjunction with the opening and closing of the electromagnetic contactor 11, outputs signals from the auxiliary contacts to external electronic control circuits, etc. The auxiliary contact unit 12 is a side-on type, installed on the side of the electromagnetic contactor 11 in the width direction. Here, the auxiliary contact unit 12 is installed on only one side of the electromagnetic contactor 11, but it can also be installed on the other side in the same way. The auxiliary contact unit 12 has a structure that allows it to be installed and removed via a snap-fit.

[0028] Figure 2 This is a diagram showing the situation after decomposition.

[0029] Here, the side furthest from the electromagnetic contactor 11 in the width direction is designated as the outer side, and the side closest to the electromagnetic contactor 11 is designated as the inner side. Figure (a) shows housing 21 (first housing), and figure (b) shows housing 31 (second housing). That is, the auxiliary contact unit 12 includes housing 21 and housing 31, which are divided in the width direction in a direction orthogonal to the side of the electromagnetic contactor 11. Both housing 21 and housing 31 are made of resin, and the inner side of housing 21 in the width direction fits into the outer side of housing 31 in the width direction.

[0030] The housing 21 includes a side wall portion 22 (first side wall portion) and a partition wall portion 23.

[0031] The sidewall portion 22 is formed as a generally flat plate parallel to the side of the electromagnetic contactor 11, that is, along the longitudinal and depth directions.

[0032] The partition wall portion 23 protrudes from the wall of the side wall portion 22 toward the housing 31, that is, toward the inside in the width direction. The partition wall portion 23 surrounds both sides in the longitudinal direction and both ends in the depth direction. In Figure (a), the front end face of the partition wall portion 23 is indicated by a shaded line. Furthermore, the range formed on both sides in the longitudinal direction along the width direction and the depth direction will be described as the main partition wall portion 23.

[0033] On the partition wall portions 23 formed on both sides in the longitudinal direction, slit-like gaps 24 are formed on the depth side in the depth direction, separating the partition wall portions 23 in the depth direction. The partition wall portions 23 separated by the gaps 24 are staggered at different heights in the longitudinal direction. Furthermore, on the partition wall portions 23 formed on both sides in the longitudinal direction, slit-like gaps 25 are formed on the front side in the depth direction, separating the partition wall portions 23 in the depth direction. The partition wall portions 23 separated by the gaps 25 are staggered at different heights in the longitudinal direction.

[0034] On the side wall portion 22, a pair of receiving wall portions 26 are formed at positions on both outer sides longitudinally beyond the pair of gaps 24. The receiving wall portions 26 receive one end of the fixed contact 43 (described later) and provide longitudinal positioning. On the side wall portion 22, a pair of receiving wall portions 27 are formed at positions on both outer sides longitudinally beyond the pair of gaps 25. The receiving wall portions 27 receive one end of the fixed contact 44 (described later) and provide longitudinal positioning.

[0035] An opening 28 that is longer in the depth direction is formed at the longitudinal center of the side wall portion 22.

[0036] The housing 31 includes a side wall portion 32 (second side wall portion) and an interlaced wall portion 33.

[0037] The sidewall portion 32 is formed as a generally flat plate parallel to the side of the electromagnetic contactor 11, that is, along the longitudinal and depth directions.

[0038] The staggered wall portion 33 protrudes from the wall surface of the side wall portion 32 along the partition wall portion 23 toward the side wall portion 22. Furthermore, the range formed on both sides in the longitudinal direction along the width direction and the depth direction will be described as the main staggered wall portion 33.

[0039] The staggered wall portions 33 formed on both sides in the longitudinal direction have slit-like gaps 34 formed on the depth side in the depth direction to separate the staggered wall portions 33 in the depth direction. In addition, the staggered wall portions 33 formed on both sides in the longitudinal direction have slit-like gaps 35 formed on the front side in the depth direction to separate the staggered wall portions 33 in the depth direction.

[0040] An opening 36 that is longer in the depth direction is formed at the longitudinal center of the side wall portion 32.

[0041] The housings 21 and 31 are fastened together by fitting their protrusions together, and when they are fitted together, the front end of the partition wall 23 abuts against the wall surface of the side wall 32. Thus, the area surrounded by the side wall 22, the partition wall 23 and the side wall 32 becomes the contact receiving part 41.

[0042] Figure 3 It is a diagram showing the components unfolded.

[0043] The auxiliary contact unit 12 includes a contact support 42, a pair of fixed contacts 43 and a pair of fixed contacts 44.

[0044] The contact support 42 is made of resin and is housed in the contact housing 41 in a state that allows it to move back and forth in the depth direction.

[0045] In the contact support 42, a movable contact 45 is provided on the depth side in the depth direction, and a movable contact 46 is provided on the front side in the depth direction. The movable contacts 45 and 46 are plate-shaped conductors extending longitudinally, protruding from the contact support 42 towards both ends in the longitudinal direction, with each end forming a double contact. The movable contact 45 has a contact point formed on its depth side surface in the depth direction, and the movable contact 46 has a contact point formed on its front side surface in the depth direction.

[0046] A connecting protrusion 47 protruding inward in the width direction is formed on the side of the contact support member 42. The connecting protrusion 47 protrudes from the side wall portion 32 through the opening portion 36 and is embedded in the connecting recess formed in the contact support member of the electromagnetic contactor 11 (not shown in the figure). Thus, when the contact support member of the electromagnetic contactor 11 moves forward and backward in the depth direction, the contact support member 42 of the auxiliary contact unit 12 moves forward and backward in the depth direction in conjunction with it.

[0047] A pair of fixed contacts 43 are plate-shaped conductors along the width and longitudinal directions, respectively inserted into the gap 24 of the partition wall 23 from the housing 31 side, with their longitudinal positions determined by the receiving wall 26. At the inner end of the fixed contact 43, which is the longitudinal direction, a contact point is formed on the face facing forward in the depth direction, and a threaded hole for a threaded terminal is formed on the outer side in the longitudinal direction. The auxiliary contact, composed of the fixed contact 43 and the movable contact 45, is a normally open type a contact. That is, when the main contacts of the electromagnetic contactor 11 are open, the contact support member 42 is located on the face facing forward in the depth direction, thereby causing the movable contact 45 to move away from the fixed contact 43, and the auxiliary contact opens. On the other hand, when the main contacts of the electromagnetic contactor 11 are closed, the contact support member 42 is located on the depth side in the depth direction, thereby causing the movable contact 45 to contact the fixed contact 43, and the auxiliary contact closes.

[0048] A pair of fixed contacts 44 are plate-shaped conductors along the width and longitudinal directions, respectively inserted into the gaps 25 of the partition wall portion 23 from the housing 31 side, with their longitudinal positions determined by the receiving wall portion 27. At the end of the fixed contact 44 that forms the inner side in the longitudinal direction, a contact point is formed on the surface on the depth side in the depth direction, and a threaded hole for a threaded terminal is formed on the outer side in the longitudinal direction. Here, the auxiliary contact formed by the fixed contact 44 and the movable contact 46 is a normally closed type b contact. That is, when the main contacts of the electromagnetic contactor 11 are open, the contact support member 42 is located on the front side in the depth direction, thereby the movable contact 46 contacts the fixed contact 44, and the auxiliary contact closes. On the other hand, when the main contacts of the electromagnetic contactor 11 are closed, the contact support member 42 is located on the depth side in the depth direction, thereby the movable contact 46 moves away from the fixed contact 44, and the auxiliary contact opens.

[0049] Figure 4 This diagram shows the state of the fixed contacts assembled.

[0050] Here, the housing 31 is omitted, indicating the state of the housing 21 as viewed from the inside in the width direction. Additionally, the front end face of the partition wall 23 is indicated by a shading line.

[0051] The fixed contact 43 is disposed longitudinally on the inner side of the contact receiving portion 41 via the partition wall portion 23, and longitudinally on the outer side of the contact receiving portion 41. The plate thickness t of the fixed contact 43 is equivalent to the depth dimension of the gap 24. Therefore, when the fixed contact 43 is inserted into the gap 24, the slits of the partition wall portion 23 abut against both sides of the fixed contact 43 in the depth direction, and the gap becomes zero. In addition, when the housing 31 is fitted, the fixed contact 43 passes through the staggered wall portion 33 via the gap 34. The depth dimension of the gap 34 is larger than the plate thickness t of the fixed contact 43.

[0052] Similarly, the fixed contact 44 is disposed longitudinally on the inner side of the contact receiving portion 41 and longitudinally on the outer side of the contact receiving portion 41 via the partition wall portion 23. The plate thickness t of the fixed contact 44 is equivalent to the depth dimension of the gap 25. Therefore, when the fixed contact 44 is inserted into the gap 25, the slits of the partition wall portion 23 abut against both sides of the fixed contact 44 in the depth direction, and the gap becomes zero. In addition, when the housing 31 is fitted, the fixed contact 44 passes through the staggered wall portion 33 via the gap 35. The depth dimension of the gap 35 is larger than the plate thickness t of the fixed contact 44.

[0053] Next, the staggered wall portion 33 will be described.

[0054] Figure 5 This is a diagram showing the cross-section of the auxiliary contact unit.

[0055] (a) in the figure represents Figure 4The AA section, in the figure (b) represents Figure 4 The BB section. Here, it represents the assembled state of the shell 31. The structure of the staggered wall portion 33 is common in any section.

[0056] The staggered wall portion 33 is disposed inside the contact receiving portion 41 in a manner that staggers with the partition wall portion 23. The thickness of the staggered wall portion 33 is less than the thickness of the partition wall portion 23. A step is provided on the front end side of the staggered wall portion 33, and the thickness of the front end portion 37 is less than that of the root end side. A protrusion 29 is formed on the side wall portion 22, protruding from the wall surface along the front end portion 37 of the staggered wall portion 33. The front end portion 37 of the staggered wall portion 33 is disposed between the partition wall portion 23 and the protrusion 29. Figure 4 As shown, the protrusion 29 is formed continuously along the depth direction.

[0057] To account for molding errors, a small gap is provided between the staggered wall portion 33 and the partition wall portion 23, ensuring they are in a non-contact state. The width dimension of the staggered wall portion 33 is smaller than that of the partition wall portion 23. Therefore, when the housing 21 and housing 31 are fitted together, the front end of the partition wall portion 23 abuts against the wall surface of the side wall portion 32, whereas the front end of the staggered wall portion 33 does not abut against the wall surface of the side wall portion 22.

[0058] To account for molding errors, a small gap is provided between the front end portion 37 of the interlaced wall portion 33 and the protrusion 29, ensuring they are in a non-contact state. The width dimension of the protrusion 29 is smaller than the width dimension of the front end portion 37. Therefore, when the housing 21 and housing 31 are fitted together, the front end of the protrusion 29 does not abut against the stepped surface of the front end portion 37 of the interlaced wall portion 33.

[0059] <Function>

[0060] Next, the main functions of one implementation method will be explained.

[0061] When dust enters the interior of the housing, particularly the contact storage section 41, the auxiliary contact unit 12 may experience poor contact. In this embodiment, the housing includes a housing 21 and a housing 31 divided in the width direction. A partition wall 23 protruding towards the housing 31 is formed on the side wall 22 of the housing 21. On the other hand, an interlaced wall 33 protruding along the partition wall 23 is formed on the side wall 32 of the housing 31. Therefore, for dust to enter the contact storage section 41, it must pass between the partition wall 23 and the interlaced wall 33. That is, the intrusion path to the contact storage section 41 is lengthened, making it less likely for dust to enter and improving dustproof performance.

[0062] Figure 6 It is a diagram showing the intrusion path of dust.

[0063] (a) in the figure represents Figure 4 The AA section, in the figure (b) represents Figure 4 The BB section. Here, it represents the assembled state of the shell 31. The structure of the staggered wall portion 33 is common in any section.

[0064] The intrusion path of dust is indicated by thick solid arrows. Dust enters the contact receiving portion 41 through the space between the front end of the partition wall 23 and the wall surface of the side wall 32, through the space between the partition wall 23 and the staggered wall 33, and through the space between the front end 37 of the staggered wall 33 and the wall surface of the side wall 22. Furthermore, it enters the contact receiving portion 41 through the space between the front end 37 of the staggered wall 33 and the protrusion 29, and through the space between the front end of the protrusion 29 and the stepped surface of the front end 37 of the staggered wall 33. This elongated intrusion path into the contact receiving portion 41 makes it less likely for dust to enter, thus improving dustproof performance.

[0065] Furthermore, the fixed contacts 43 and 44 are respectively separated by the partition wall 23 and the staggered wall 33, with gaps 24 and 25 of the same thickness t as the plate thickness of the fixed contact 43 and 44 respectively formed in the partition wall 23. The fixed contacts 43 and 44 are then inserted into the housing 31 side through gaps 24 and 25 respectively. At this time, the fixed contacts 43 and 44 abut against the slits of the partition wall 23 on both sides in the depth direction, resulting in zero gaps. Similarly, the fixed contacts 44 and 43 abut against the slits of the partition wall 23 on both sides in the depth direction, also resulting in zero gaps. Therefore, dust is less likely to enter the contact housing 41, improving dustproof performance.

[0066] Furthermore, the staggered wall portion 33 is disposed inside the contact receiving portion 41, and a protrusion 29 is formed on the side wall portion 22, protruding along the front end portion 37 of the staggered wall portion 33. That is, the front end portion 37 of the staggered wall portion 33 is disposed between the partition wall portion 23 and the protrusion 29. Warping or deflection may occur in the staggered wall portion 33, but because the protrusion 29 is close to the front end portion 37 of the staggered wall portion 33, it is possible to prevent the staggered wall portion 33 from tilting towards the movable contact 45 and movable contact 46 due to warping or deflection. Therefore, it will not cause any obstruction to the separation and contact of the contacts as the contact support member 42 moves forward and backward.

[0067] Furthermore, the thickness of the front end portion 37 of the interlaced wall portion 33 is smaller than that of the root end portion. Therefore, the thickness of the front end portion 37 can be reduced by moving the protrusion 29 closer to the partition wall portion 23. As a result, the narrowing of the space of the contact receiving portion 41 due to the protrusion 29 can be suppressed.

[0068] Furthermore, the thickness of the staggered wall portion 33 is smaller than the thickness of the partition wall portion 23. As a result, the narrowing of the space in the contact receiving portion 41 due to the staggered wall portion 33 can be prevented.

[0069] Furthermore, the width direction (protruding direction) dimension of the staggered wall portion 33 is smaller than the width direction (protruding direction) dimension of the partition wall portion 23. Therefore, when the housing 21 and housing 31 are fitted together, the front end of the partition wall portion 23 abuts against the wall surface of the side wall portion 32, unlike the staggered wall portion 33, which does not abut against the wall surface of the side wall portion 22. This is to prevent cracks or breakage in the staggered wall portion 33 when the housing 21 and housing 31 are fastened with threaded parts (e.g., screws) because the thickness of the staggered wall portion 33 is smaller than that of the partition wall portion 23, resulting in lower load-bearing capacity in the width direction. In other words, when the housing 21 and housing 31 are fastened with threaded parts, the force in the width direction that brings them into contact is borne only by the partition wall portion 23. Thus, cracks or breakage in the staggered wall portion 33 can be prevented when the housing 21 and housing 31 are fastened with threaded parts.

[0070] Next, the comparative examples will be explained.

[0071] Figure 7 This is a diagram representing Comparative Example 1.

[0072] The auxiliary contact unit 51 in Comparative Example 1 has a structure that is divided at the center in the width direction, and its dividing surface 52 is shown as a thick dashed line. In this structure, which is divided at the center in the width direction, dust can enter the interior from the dividing surface 52, potentially causing poor contact of the contacts. In contrast, in this embodiment, as described above, because staggered wall portions 33 are formed, dust is less likely to enter, and the dustproof performance is improved.

[0073] Figure 8 This is a diagram representing comparison example 2.

[0074] The auxiliary contact unit 61 in Comparative Example 2 is a one-piece molded structure that is not divided in the width direction. In this case, it has an insertion hole 63 for inserting the fixed contact 62 longitudinally, but in order to allow the fixed contact 64 in the fixed contact 62 to pass through, the height dimension of the insertion hole 63 is set to be larger than the thickness of the fixed contact 62. Therefore, in the one-piece molded structure, a gap is formed between the insertion hole 63 and the fixed contact 62, from which dust may enter the interior, potentially causing poor contact of the contacts. In contrast, in this embodiment, as described above, the fixed contact 43 and the fixed contact 44 can be inserted from the housing 31 side, and the slits of the partition wall 23 abut against both sides in the depth direction, with zero gap. Therefore, dust is less likely to enter, and the dustproof performance is improved.

[0075] <Variation Example>

[0076] In one embodiment, a partition wall portion 23 is formed on the side wall portion 22 of the housing 21, and an interlaced wall portion 33 is formed on the side wall portion 32 of the housing 31, but this is not a limitation. Alternatively, the interlaced wall portion 33 may be formed on the side wall portion 22 of the housing 21, and the partition wall portion 23 may be formed on the side wall portion 32 of the housing 31.

[0077] In one embodiment, main staggered wall portions 33 are formed on both sides of the longitudinal direction of the partition wall portion 23, relative to the range formed along the width direction and the depth direction, but it is not limited to this. That is, staggered wall portions may also be formed on both sides of the partition wall portion 23 in the depth direction, along the range formed along the width direction and the longitudinal direction.

[0078] In one embodiment, a small gap is provided between the staggered wall portion 33 and the partition wall portion 23 to account for errors during molding, but this is not a limitation; the staggered wall portion 33 and the partition wall portion 23 can also be in surface contact. As a result, dust is less likely to penetrate, and the dustproof performance is improved.

[0079] In one embodiment, the protrusions 29 are formed continuously along the depth direction, but this is not a limitation. That is, the protrusions 29 may also be formed in a manner that distributes them at predetermined intervals along the depth direction.

[0080] In one embodiment, the depth dimension of the gap 34 is larger than the plate thickness t of the fixed contact 43, but this is not a limitation. That is, the depth dimension of the gap 34 can also be equal to the plate thickness t of the fixed contact 43. The same applies to the gap 35 and the fixed contact 44. As a result, dust is less likely to enter, and the dustproof performance is improved.

[0081] In one embodiment, the partition wall portions 23 separated by the gap 24 are offset at different heights in the longitudinal direction, but this is not a limitation. That is, the partition wall portions 23 separated by the gap 24 may not be offset in the longitudinal direction. The same applies to the partition wall portions 23 separated by the gap 25.

[0082] The above description refers to a limited number of embodiments, but the scope of the present invention is not limited thereto. Those skilled in the art will be able to understand changes based on the embodiments described above.

[0083] Explanation of reference numerals in the attached figures

[0084] 11... Electromagnetic contactor

[0085] 12……Auxiliary contact unit

[0086] 21……shell

[0087] 22……Side wall portion

[0088] 23……Separation wall section

[0089] 24...gap

[0090] 25...gap

[0091] 26……Receiving wall section

[0092] 27……Receiving wall section

[0093] 28……Opening

[0094] 29……protrusions

[0095] 31……shell

[0096] 32……Side wall portion

[0097] 33……Interlaced walls

[0098] 34...gap

[0099] 35...gap

[0100] 36……Opening

[0101] 37……Front end

[0102] 41...Touchpoint Storage Department

[0103] 42……Contact support component

[0104] 43……Fixed contact

[0105] 44……Fixed contact

[0106] 45……Modible contact

[0107] 46……Modible contact

[0108] 47... Linked protrusions

[0109] 51……Auxiliary contact unit

[0110] 52……Dividing surface

[0111] 61……Auxiliary contact unit

[0112] 62……Fixed contact

[0113] 63……Insert Hole

[0114] 64……Fixed contact.

Claims

1. An auxiliary contact unit installed to a side surface of an electromagnetic contactor, the auxiliary contact unit characterized by: a first housing and a second housing divided in a direction orthogonal to a side surface of the electromagnetic contactor, the first housing including: a first side wall portion parallel to the side surface of the electromagnetic contactor; and a partition wall portion protruding from a wall surface of the first side wall portion toward the second housing, the second housing including a second side wall portion parallel to the side surface of the electromagnetic contactor, and a front end of the partition wall portion abutting against a wall surface when the first housing is fitted, a range surrounded by the first side wall portion, the partition wall portion, and the second side wall portion becomes a contact receiving portion, the second side wall portion including a stagger wall portion protruding from a wall surface toward the first side wall portion along the partition wall portion, the stagger wall portion being disposed inside the contact receiving portion, the first side wall portion including a protrusion portion protruding from a wall surface toward a front end portion of the stagger wall portion, the front end portion of the stagger wall portion being disposed between the partition wall portion and the protrusion portion.

2. The auxiliary contact unit according to claim 1, characterized by: including a fixed contact of a plate shape, one end side of which is disposed inside the contact receiving portion, and the other end side of which is disposed outside the contact receiving portion, through both the partition wall portion and the stagger wall portion, a gap of an amount of a plate thickness of the fixed contact being formed in the partition wall portion, the fixed contact being fitted into the gap from the second housing side.

3. The auxiliary contact unit according to claim 1 or 2, characterized by: a thickness of the front end portion of the stagger wall portion being smaller than a thickness of a root end side.

4. The auxiliary contact unit according to claim 1 or 2, characterized by: a thickness of the stagger wall portion being smaller than a thickness of the partition wall portion.

5. The auxiliary contact unit according to claim 4, characterized by: a dimension of a protruding direction of the stagger wall portion from the second side wall portion toward the first side wall portion along the partition wall portion being smaller than a dimension of the protruding direction of the partition wall portion.

6. An auxiliary contact unit installed to a side surface of an electromagnetic contactor, the auxiliary contact unit characterized by: a first housing and a second housing divided in a direction orthogonal to a side surface of the electromagnetic contactor, the first housing including: a first side wall portion parallel to the side surface of the electromagnetic contactor; and a partition wall portion protruding from a wall surface of the first side wall portion toward the second housing, the second housing including a second side wall portion parallel to the side surface of the electromagnetic contactor, and a front end of the partition wall portion abutting against a wall surface when the first housing is fitted by a screw member, a range surrounded by the first side wall portion, the partition wall portion, and the second side wall portion becomes a contact receiving portion, the second side wall portion including a stagger wall portion protruding from a wall surface toward the first side wall portion along the partition wall portion, a thickness of the stagger wall portion being smaller than a thickness of the partition wall portion, a dimension of a protruding direction of the stagger wall portion from the second side wall portion toward the first side wall portion along the partition wall portion being smaller than a dimension of the protruding direction of the partition wall portion. ​ ​

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