An electromagnetic relay with a compression spring

Abstract

The present invention discloses an electromagnetic relay with a compression spring, which comprises a coil bobbin, a yoke, an armature and a compression spring; the compression spring includes a fixing part and a leaf spring part, the compression spring is fixed on the coil bobbin through the fixing part, and the leaf spring part limits the armature at the knife edge of the yoke; the fixing part of the compression spring is in a U shape, a part of the coil bobbin is fitted into the U-shaped opening of the U shape of the compression spring, and first and second convex parts are respectively and outwardly protrudingly provided on opposite sides of a part of the coil bobbin; the compression spring is provided with first and second clamping parts corresponding to and cooperating with the first and second convex parts, and the first clamping part is fitted into the first convex part with a clearance fit, and the second clamping part is fitted into the second convex part with an elastic interference fit. The present invention can not only reduce the generation of plastic scraps during the assembly process of the compression spring, but also prevent the phenomena of deformation or improper assembly of the compression spring, and can better block the plastic scraps from entering the area of the contact end.

Description

Technical Field

[0001] The present invention relates to the technical field of relays, and particularly to an electromagnetic relay with a compression spring. Background Art

[0002] A relay is an electronic control device that has a control system (also known as an input circuit) and a controlled system (also known as an output circuit). It is usually applied in an automatic control circuit. In fact, it is an "automatic switch" that uses a smaller current to control a larger current. Therefore, it plays roles such as automatic regulation, safety protection, and circuit conversion in the circuit. An electromagnetic relay with a compression spring in the prior art uses the compression spring to limit the armature at the edge of the yoke, so that the armature can swing around the edge of the yoke, be attracted to the pole face of the iron core when the coil is energized, and reset and leave the pole face of the iron core when the coil is de-energized. This compression spring is usually fixed on the yoke or fixed on the base through the slot of the base, and then the elastic piece in the compression spring is used to limit the armature. The compression spring with this structure mainly brings the following disadvantages:

[0003] First, during the assembly process of the compression spring, it is easy to generate scraping debris, which affects the stability of the relay parameters. Especially when plastic debris reaches the contact end, it will cause the phenomenon that the relay does not conduct.

[0004] Second, during the assembly process of the compression spring, it is easy to cause the phenomenon of assembly deformation or improper assembly. After the compression spring is deformed, the acting point of the compression spring will shift, thus affecting the operating voltage and release voltage of the product. Summary of the Invention

[0005] The purpose of the present invention is to overcome the deficiencies of the prior art and provide an electromagnetic relay with a compression spring. Through structural improvement, it can not only reduce the generation of plastic debris during the assembly process of the compression spring, but also prevent the phenomenon of assembly deformation or improper assembly of the compression spring, and can better block the plastic debris from entering the area of the contact end.

[0006] The technical solution adopted by the present invention to solve its technical problems is as follows: An electromagnetic relay with a compression spring, comprising a coil bobbin, a yoke, an armature and a compression spring; the yoke is installed beside the coil bobbin; the armature is fitted at the knife edge of the yoke; the compression spring includes a fixing part and a spring piece part, the compression spring is fixed on the coil bobbin through the fixing part, and the spring piece part of the compression spring limits the armature at the knife edge of the yoke, so that the armature can swing around the knife edge of the yoke; the fixing part of the compression spring is in a U shape, and a part of the coil bobbin is fitted in the U-shaped opening of the U shape of the compression spring, and first convex parts and second convex parts are respectively protruded outward from the opposite two side edges of a part of the coil bobbin; first clamping parts and second clamping parts corresponding to and mating with the first convex part and the second convex part are respectively arranged at the two side walls of the U shape of the compression spring, and the first clamping part and the first convex part are fitted in a clearance fit to avoid the generation of plastic scraps, and the second clamping part and the second convex part are fitted in an elastic interference fit to ensure that the compression spring is assembled in place and prevent the compression spring from deforming.

[0007] The first clamping part of the compression spring is a first through hole arranged on one side wall of the U shape of the compression spring; the second clamping part of the compression spring is a second through hole arranged on the other side wall of the U shape of the compression spring and an elastic clamping tongue extending from the hole edge of the second through hole into the U-shaped opening.

[0008] The first through hole of the compression spring and the first convex part on one side edge of a part of the coil bobbin are in a clearance fit, the second through hole of the compression spring and the second convex part on the other side edge of a part of the coil bobbin are fitted, and the elastic clamping tongue of the compression spring abuts against the other side edge of a part of the coil bobbin and abuts against the second convex part of the coil bobbin.

[0009] The elastic clamping tongue extends upward and into the U-shaped opening from the lower hole edge of the second through hole on the other side wall of the U shape of the compression spring. When the compression spring is fitted with the coil bobbin, the elastic clamping tongue of the compression spring abuts against the lower surface of the second convex part of the coil bobbin to prevent the compression spring from disengaging from the coil bobbin upward.

[0010] The U shape of the compression spring is integrally bent from a sheet body, and the elastic clamping tongue is integrally extended from the lower hole edge of the second through hole on the other side wall of the U shape of the compression spring.

[0011] In the other side edge of a part of the coil bobbin, a groove recessed inward is further provided corresponding to the lower surface of the second convex part, and the elastic clamping tongue of the compression spring is embedded in the groove.

[0012] On one side of a part of the coil bobbin, a first convex portion is provided with a chamfer or a fillet at its outer edge on the upper surface, and on the upper surface of a second convex portion on the other side of a part of the coil bobbin, a chamfer or a fillet is also provided at its outer edge, so as to facilitate the insertion of the two side walls of the U-shaped compression spring.

[0013] The upper hole edges of the first through hole and the second through hole of the compression spring are flush with each other, and the upper contour position of the second convex portion of the coil bobbin is higher than the upper contour position of the first convex portion of the coil bobbin.

[0014] The coil bobbin is provided with an iron core hole which is vertically arranged. The yoke is L-shaped. The horizontal side of the L-shaped yoke is fitted at the bottom end of the coil bobbin, and the vertical side of the L-shaped yoke is fitted beside the winding window of the coil bobbin. The armature is L-shaped, and the bent portion of the L-shaped armature is fitted at the upper edge of the vertical side of the L-shaped yoke. A part of the coil bobbin is a part of the upper flange of the coil bobbin. The U-shaped opening of the U-shaped compression spring is sleeved from top to bottom onto a part of the upper flange of the coil bobbin, and the elastic piece portion of the compression spring abuts against the outer side of the bent portion of the L-shaped armature.

[0015] The elastic piece portion of the compression spring is formed by extending the top wall of the U-shaped part of the sheet body in one direction. The elastic piece portion includes a first section which is integrally and straightly connected to the top wall of the U-shaped part, a second section which is bent downward from the end of the first section, a third section which is bent downward again from the end of the second section, and a vertical fourth section which is bent downward again from the end of the second section. The third section of the elastic piece portion of the compression spring presses against the outer side of the bent portion of the L-shaped armature, and the included angle between the third section and the first section of the elastic piece portion of the compression spring is 45 degrees.

[0016] The relay further includes a housing, a base, a contact part and a push card. The contact part and the coil bobbin are respectively installed in the base. In the base, a first retaining wall is provided between the contact part and the coil bobbin. The push card is fitted in the first retaining wall. The two ends of the push card are respectively and correspondingly matched with the contact part and the armature on both sides of the first retaining wall. The housing is sleeved outside the base and houses the contact part and the coil bobbin therein. A second retaining wall which intersects with the first retaining wall is provided downward on the top wall inside the housing, so as to isolate the coil part from the contact part.

[0017] Compared with the prior art, the beneficial effects of the present invention are:

[0018] 1. In the present invention, the compression spring is designed to include a fixing part and a leaf spring part. The compression spring is fixed on the bobbin through the fixing part, and the leaf spring part of the compression spring limits the armature at the blade edge of the yoke, enabling the armature to swing around the blade edge of the yoke. The fixing part of the compression spring is in a U shape, and a part of the bobbin is fitted inside the U-shaped opening of the U shape of the compression spring. First convex parts and second convex parts are respectively and outwardly protrudingly provided on the opposite two side edges of a part of the bobbin. First clamping parts and second clamping parts corresponding to and mating with the first convex part and the second convex part are respectively provided at the two side walls of the U shape of the compression spring. The first clamping part and the first convex part are fitted in a clearance fit, and the second clamping part and the second convex part are fitted in an elastic interference fit. With this structure of the present invention, by using the clearance fit on one side of the compression spring, the generation of plastic chips on one side during the assembly of the compression spring can be avoided, thereby reducing the generation of plastic chips during the assembly process of the compression spring. Then, by using the elastic interference fit on the other side during the assembly of the compression spring, the phenomena of deformation or improper assembly of the compression spring can be prevented, ensuring the stability of the relay parameters.

[0019] 2. In the present invention, the first clamping part of the compression spring is set as a first through hole on one side wall of the U shape of the compression spring; the second clamping part of the compression spring is set as a second through hole on the other side wall of the U shape of the compression spring and an elastic clamping tongue extending from the hole edge of the second through hole into the U-shaped opening. The U shape of the compression spring is integrally bent from a sheet body, and the elastic clamping tongue is integrally extended from the second through hole on the other side wall of the U shape of the compression spring. With this structure of the present invention, the structure of the compression spring is simple and easy to manufacture, and can preferably prevent the deformation of the compression spring during assembly.

[0020] 3. In the present invention, a first retaining wall is provided in the base, and a second retaining wall intersecting with the first retaining wall is provided in the housing. The first retaining wall and the second retaining wall can prevent the plastic chips generated during the assembly of the compression spring from entering the area of the contact end, avoiding the occurrence of the phenomenon that the relay is not conducting.

[0021] The following further describes the present invention in detail with reference to the drawings and embodiments; however, an electromagnetic relay with a compression spring of the present invention is not limited to the embodiments. Description of the Drawings

[0022] Figure 1 is a schematic exploded perspective view of the embodiment of the present invention;

[0023] Figure 2 is a structural cross-sectional view of the embodiment of the present invention;

[0024] Figure 3 is the front view (without the housing) of the embodiment of the present invention;

[0025] Figure 4Is the rear view of the embodiment of the present invention (without the outer shell);

[0026] Figure 5 Is the schematic assembly diagram of the bobbin, compression spring, armature and yoke of the embodiment of the present invention;

[0027] Figure 6 Is the schematic assembly diagram of the bobbin and the compression spring of the embodiment of the present invention;

[0028] Figure 7 Is the schematic assembly diagram of the bobbin and the compression spring of the embodiment of the present invention (rotated by an angle);

[0029] Figure 8 Is the structural cross-sectional view of the bobbin of the embodiment of the present invention (with enameled wire installed);

[0030] Figure 9 Is the schematic structural diagram of the compression spring of the embodiment of the present invention;

[0031] Figure 10 Is the schematic structural diagram of the compression spring of the embodiment of the present invention (rotated by an angle). Detailed implementation manners

[0032] Embodiment

[0033] Refer to Figures 1 to 10 As shown, an electromagnetic relay with a compression spring of the present invention includes an armature 1, a bobbin 2, a yoke 3 and a compression spring 4; the yoke 3 is installed beside the bobbin 2; the armature 1 is fitted at the blade edge of the yoke 3; the compression spring 4 includes a fixing portion 41 and a spring piece portion 42, the compression spring 4 is fixed on the bobbin 2 through the fixing portion 41, and the spring piece portion 42 of the compression spring 4 limits the armature 1 at the blade edge of the yoke 3, so that the armature 1 can swing around the blade edge of the yoke 3; the fixing portion 41 of the compression spring 4 is in a U shape, and a part of the bobbin 2 is fitted in the U-shaped opening of the U shape of the compression spring 4, and opposite two side edges of a part of the bobbin 2 are respectively provided with a first convex portion 21 and a second convex portion 22 protruding outward; first clamping portions and second clamping portions corresponding to the first convex portion and the second convex portion are respectively provided at two side walls of the U shape of the compression spring 4, and the first clamping portion and the first convex portion 21 are fitted in a clearance fit to avoid the generation of plastic chips, and the second clamping portion and the second convex portion 22 are fitted in an elastic interference fit to ensure that the compression spring 4 is assembled in place and prevent the compression spring 4 from deforming.

[0034] In this embodiment, the first clamping portion of the compression spring 4 is a first through hole 412 provided on one side wall 411 of the U-shaped portion of the compression spring 4; the second clamping portion of the compression spring 4 is a second through hole 414 provided on the other side wall 413 of the U-shaped portion of the compression spring 4 and an elastic clamping tongue 415 extending from the edge of the second through hole 414 into the U-shaped opening.

[0035] In this embodiment, the first through hole 412 of the compression spring 4 is in clearance fit with a first convex portion 21 on one side edge of a part of the coil holder 2, and the second through hole 414 of the compression spring 4 is engaged with a second convex portion 22 on the other side edge of a part of the coil holder 2, such that the elastic clamping tongue 415 of the compression spring 4 abuts against the other side edge of a part of the coil holder 2 and abuts against the second convex portion 22 of the coil holder 2.

[0036] In this embodiment, the elastic clamping tongue 415 extends upward and into the U-shaped opening from the lower edge of the second through hole 414 on the other side wall 413 of the U-shaped portion of the compression spring 4. When the compression spring 4 is engaged with the coil holder 2, the elastic clamping tongue 415 of the compression spring 4 abuts against the lower surface of the second convex portion 22 of the coil holder 2 to prevent the compression spring 4 from disengaging upward from the coil holder 2.

[0037] In this embodiment, the U-shaped portion of the compression spring 4 is integrally formed by bending a sheet body, and the elastic clamping tongue 415 is integrally extended from the lower edge of the second through hole 414 on the other side wall 413 of the U-shaped portion of the compression spring 4.

[0038] In this embodiment, in the other side edge of a part of the coil holder 2, a groove 23 recessed inward is further provided corresponding to the lower surface of the second convex portion 22, and the elastic clamping tongue 415 of the compression spring 4 is inserted into the groove 23.

[0039] In this embodiment, a rounded corner or chamfer 211 is provided on the outer edge of the upper surface of the first convex portion 21 on one side edge of a part of the coil holder 2, and a rounded corner or chamfer 221 is also provided on the outer edge of the upper surface of the second convex portion 22 on the other side edge of a part of the coil holder 2 to facilitate the insertion of the two side walls of the compression spring 4.

[0040] In this embodiment, the upper edges of the first through hole 412 and the second through hole 414 of the compression spring 4 are flush, and the upper contour position of the second convex portion 22 of the coil holder 2 is higher than the upper contour position of the first convex portion 21 of the coil holder 2.

[0041] In this embodiment, the bobbin 2 is provided with a core hole, and a core 51 is installed in the core hole. The core hole of the bobbin 2 is vertically arranged. The yoke 3 is L-shaped. The horizontal side 31 of the L-shaped yoke 3 is fitted at the bottom end of the bobbin 2. The vertical side 32 of the L-shaped yoke 3 is fitted beside the winding window of the bobbin 2. The armature 1 is L-shaped. The bent portion 11 of the L-shaped armature 1 is fitted at the upper edge (i.e., the cutting edge) of the vertical side 32 of the L-shaped yoke 3. A part of the bobbin 2 is a part of the upper flange 24 of the bobbin. The U-shaped opening of the U-shaped spring 4 is sleeved from top to bottom on a part of the upper flange 24 of the bobbin 2. The spring piece part 42 of the spring 4 abuts against the outside of the bent portion 11 of the L-shaped armature 1.

[0042] In this embodiment, the spring piece part 42 of the spring 4 is formed by the top wall 416 of the U-shaped sheet body extending in one side direction. The spring piece part 42 includes a first section 421 that is integrally and straightly connected to the top wall 416 of the U-shaped shape, a second section 422 that is bent downward from the end of the first section, a third section 423 that is bent downward again from the end of the second section, and a vertical fourth section 424 that is bent downward again from the end of the second section. The third section 423 of the spring piece part of the spring 4 presses against the outside of the bent portion 11 of the L-shaped armature 1. The included angle between the third section 423 of the spring piece part of the spring 4 and the first section 421 of the spring piece part of the spring 4 is 45 degrees.

[0043] In this embodiment, the relay further includes a housing 52, a base 53, a contact part 54 (including a moving spring and a static spring), and a pushing card 55. The contact part 54 and the bobbin 2 are respectively installed in the base 53. In the base 53, a first retaining wall 531 is provided between the contact part 54 and the bobbin 2. The pushing card 55 is fitted in the first retaining wall. The two ends of the pushing card 55 are respectively and correspondingly matched with the contact part 54 and the armature 1 on both sides of the first retaining wall. The housing 52 is sleeved outside the base 53 and houses the contact part 54 and the bobbin 2 therein. A second retaining wall 521 that intersects with the first retaining wall is provided downward on the top wall inside the housing 52 to isolate the coil part from the contact part.

[0044] An electromagnetic relay with a compression spring according to the present invention adopts a structure in which the compression spring 4 is designed to include a fixing portion 41 and a leaf spring portion 42. The compression spring 4 is fixed to the bobbin 2 through the fixing portion 41, and the leaf spring portion 42 of the compression spring 4 limits the armature 1 at the edge of the yoke 3, so that the armature 1 can swing around the edge of the yoke 3. The fixing portion 41 of the compression spring 4 is U-shaped, and a part of the bobbin 2 is fitted into the U-shaped opening of the U-shaped portion of the compression spring 4. Opposite sides of a part of the bobbin 2 respectively protrude outwardly to form a first protrusion 21 and a second protrusion 22. First engaging portions and second engaging portions corresponding to the first protrusion and the second protrusion are respectively provided at two side walls of the U-shaped portion of the compression spring 4. The first engaging portion and the first protrusion are fitted in a clearance fit, and the second engaging portion and the second protrusion are fitted in an elastic interference fit. With this structure of the present invention, the generation of plastic chips on one side during the assembly of the compression spring 4 can be avoided by using the clearance fit on one side of the compression spring 4, thereby reducing the generation of plastic chips during the assembly of the compression spring 4. Then, by using the elastic interference fit on the other side during the assembly of the compression spring 4, the phenomenon of deformation or improper assembly of the compression spring can be prevented, ensuring the stability of the relay parameters.

[0045] An electromagnetic relay with a compression spring according to the present invention adopts a structure in which the first engaging portion of the compression spring 4 is set as a first through hole 412 on one side wall of the U-shaped portion of the compression spring; the second engaging portion of the compression spring 4 is set as a second through hole 414 on the other side wall of the U-shaped portion of the compression spring and an elastic tongue 415 extending from the edge of the second through hole into the U-shaped opening. The U-shaped portion of the compression spring 4 is integrally bent from a sheet body, and the elastic tongue 415 is integrally extended from the second through hole on the other side wall of the U-shaped portion of the compression spring 4. With this structure of the present invention, the compression spring has a simple structure and is easy to manufacture, and can better prevent the deformation of the compression spring during assembly.

[0046] An electromagnetic relay with a compression spring according to the present invention adopts a structure in which a first retaining wall 531 is provided in the base 53, and a second retaining wall 521 intersecting with the first retaining wall is provided in the housing 52. The first retaining wall 531 and the second retaining wall 521 can prevent plastic chips generated during the assembly of the compression spring 4 from entering the area of the contact end, avoiding the phenomenon of non-conduction of the relay.

[0047] The above are only the preferred embodiments of the present invention and do not impose any formal restrictions on the present invention. Although the present invention has been disclosed above in the preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can, without departing from the scope of the technical solution of the present invention, make many possible changes and modifications to the technical solution of the present invention by using the technical content disclosed above, or modify it into equivalent equivalent embodiments. Therefore, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the scope of protection of the technical solution of the present invention.

Claims

1. An electromagnetic relay with a compression spring, comprising a coil bobbin, a yoke, an armature and a compression spring; the yoke is installed beside the coil bobbin; the armature is fitted at the cutting edge of the yoke; the compression spring includes a fixing portion and a spring piece portion, the compression spring is fixed on the coil bobbin through the fixing portion, and the spring piece portion of the compression spring limits the armature at the cutting edge of the yoke, so that the armature can swing around the cutting edge of the yoke; Characterized in that: The fixing portion of the compression spring is in a U shape, a part of the coil bobbin is fitted in the U-shaped opening of the U shape of the compression spring, and first convex portions and second convex portions are respectively protruded outward from opposite sides of a part of the coil bobbin; first clamping portions and second clamping portions corresponding to the first convex portion and the second convex portion are respectively provided at two side walls of the U shape of the compression spring, and the first clamping portion and the first convex portion are fitted in a clearance fit to avoid the generation of plastic chips, and the second clamping portion and the second convex portion are fitted in an elastic interference fit to ensure that the compression spring is assembled in place and prevent the compression spring from deforming.

2. The electromagnetic relay with a compression spring according to claim 1, Characterized in that: The first clamping portion of the compression spring is a first through hole provided on one side wall of the U shape of the compression spring; the second clamping portion of the compression spring is a second through hole provided on the other side wall of the U shape of the compression spring and an elastic clamping tongue extending from the hole edge of the second through hole into the U-shaped opening.

3. The electromagnetic relay with a compression spring according to claim 2, Characterized in that: The first through hole of the compression spring and the first convex portion on one side edge of a part of the coil bobbin are in a clearance fit, the second through hole of the compression spring is fitted with the second convex portion on the other side edge of a part of the coil bobbin and the elastic clamping tongue of the compression spring abuts against the other side edge of a part of the coil bobbin and abuts against the second convex portion of the coil bobbin.

4. The electromagnetic relay with a compression spring according to claim 3, Characterized in that: The elastic clamping tongue extends upward and into the U-shaped opening from the lower hole edge of the second through hole on the other side wall of the U shape of the compression spring. When the compression spring is fitted with the coil bobbin, the elastic clamping tongue of the compression spring abuts against the lower surface of the second convex portion of the coil bobbin to prevent the compression spring from disengaging from the coil bobbin upward.

5. The electromagnetic relay with a compression spring according to claim 4, Characterized in that: The U shape of the compression spring is integrally bent from a sheet body, and the elastic clamping tongue is integrally extended from the lower hole edge of the second through hole on the other side wall of the U shape of the compression spring.

6. The electromagnetic relay with a compression spring according to claim 3, Characterized in that: In the other side edge of a part of the coil bobbin, a groove recessed inward is further provided corresponding to the lower surface of the second convex portion, and the elastic clamping tongue of the compression spring is embedded in the groove.

7. The electromagnetic relay with a compression spring according to claim 3, Characterized in that: The outer edges of the upper surfaces of the first convex portion on one side of a part of the coil holder and the second convex portion on the other side of a part of the coil holder are respectively provided with rounded corners or chamfered edges to facilitate the insertion of the two side walls of the U-shaped pressing spring.

8. The electromagnetic relay with a pressing spring according to claim 3, wherein: The upper hole edges of the first through hole and the second through hole of the pressing spring are flush, and the upper contour position of the second convex portion of the coil holder is higher than the upper contour position of the first convex portion of the coil holder.

9. The electromagnetic relay with a pressing spring according to claim 1, wherein: The coil holder is provided with an iron core hole. The iron core hole of the coil holder is arranged vertically. The yoke is L-shaped. The horizontal side of the L-shaped yoke is fitted at the bottom end of the coil holder. The vertical side of the L-shaped yoke is fitted beside the winding window of the coil holder. The armature is L-shaped. The bent part of the L-shaped armature is fitted at the upper edge of the vertical side of the L-shaped yoke. A part of the coil holder is a part of the upper flange of the coil holder. The U-shaped opening of the U-shaped pressing spring is sleeved from top to bottom on a part of the upper flange of the coil holder. The elastic piece part of the pressing spring abuts against the outside of the bent part of the L-shaped armature.

10. The electromagnetic relay with a pressing spring according to claim 9, wherein: The elastic piece part of the pressing spring is formed by the top wall of the U-shaped part of the sheet body extending in one direction. The elastic piece part includes a first section that is integrally and straightly connected to the top wall of the U-shaped part, a second section that is bent downward from the end of the first section, a third section that is bent downward from the end of the second section, and a vertical fourth section that is bent downward from the end of the second section. The third section of the elastic piece part of the pressing spring presses against the outside of the bent part of the L-shaped armature. The included angle between the third section and the first section of the elastic piece part of the pressing spring is 45 degrees.

11. The electromagnetic relay with a pressing spring according to claim 1, wherein: The relay further includes a housing, a base, a contact part, and a pushing card. The contact part and the coil holder are respectively installed in the base. In the base, a first retaining wall is provided between the contact part and the coil holder. The pushing card is fitted in the first retaining wall. The two ends of the pushing card are respectively correspondingly matched with the contact part and the armature on both sides of the first retaining wall. The housing is sleeved outside the base and houses the contact part and the coil holder therein. A second retaining wall that intersects with the first retaining wall is provided downward on the top wall inside the housing to isolate the coil part from the contact part.

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