JP2010198961A - Electromagnetic relay and control device using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable to realize stable contact operation of an electromagnetic relay. <P>SOLUTION: In the electromagnetic relay 1 realized as a so-called safety relay or the like, and equipped with the minimum 1a, 1b contacts 2, 3 to be driven by a common card 8, protrusions 75a, 76a are provided at two-forked tip parts 75, 76 in fitting a return spring 7 biasing the card 8 toward a return direction (a direction opposite to the arrow mark 82) at non-excitation of the electromagnetic block 5 between an armature block 6 and movable contact terminals 22, 32. Therefore, as one end of the card 8 is locked by protrusions formed at tongue pieces 22f, 32f of the movable contact terminals 22, 32, and the other end is locked by the protrusions 75a, 76a of the return spring 7, fall-off prevention of the card 8 can be performed even with the minimum contact structure to enhance reliability of the relay. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electromagnetic relay and a control device using the same, and more particularly to the so-called safety relay.

  The safety relay is configured to drive contacts having opposite open / close states, that is, a NO (normally open (a)) contact and an NC (normally closed (b)) contact with a common electromagnet, armature and card. When one contact is welded, the card does not move, and therefore the other contact does not open and close, and the welding of the one contact can be detected by the other contact. Therefore, such a safety relay has high safety and is used in combination with a plurality of stages in a control device for controlling a machine tool or the like, and safety measures are taken.

  Such a safety relay has been realized so far by, for example, four contacts as shown in Patent Document 1 and Patent Document 2 by the applicant, for example, 3a1b, 2a2b, or 1a3b, or shown in Patent Document 3 by the applicant. Such six contacts, for example, 5a1b and 3a3b have been realized.

  FIG. 11 is an exploded perspective view of the relay disclosed in Patent Document 3. The relay 100 has 4a2b contacts. The a contact is indicated by reference numerals 101 to 104, and the b contact is indicated by reference numerals 105 and 106. Among these contacts 101 to 106, the movable contacts 101a to 106a are driven in common by the card 107. The card 107 is formed with locking holes 101b to 106b into which the tips of the movable contacts 101a to 106a are fitted. The outermost contacts 101 and 102 are fixed to the a contact, and the remaining contact For the contacts 103 to 106, dummy locking holes are also formed so that the contacts a and b can be arbitrarily selected.

  When the electromagnet 108 is not excited, the card 107 is displaced in the direction opposite to the arrow 110 by the return spring 109, the b contacts 105 and 106 are turned on, and the a contacts 101 to 104 are turned off. On the other hand, when the electromagnet 108 is excited, the card 107 is displaced in the direction of the arrow 110 by the armature 111, the b contacts 105 and 106 are turned off, and the a contacts 101 to 104 are turned on.

  However, there are cases where many such contacts are not required. For example, as shown in Patent Document 4, an example of two contacts has been proposed.

International Publication No. 06-006557 Pamphlet JP 2000-257882 A Japanese Patent Laid-Open No. 2006-196381 JP-A-11-339624

  12 is a longitudinal sectional view of the relay 120 of Patent Document 4, FIG. 13 is a horizontal sectional view, and FIG. 14 is a longitudinal sectional view taken along section line XIV-XIV in FIGS. 12 and 13. Indicates. From FIG. 13 in which a part of the card 121 is cut out, this relay 120 seems to have a contact point 1a1b (a contact point is indicated by reference numeral 123 and a b contact point is indicated by reference numeral 124). In this relay, the card 121 is slid in the arrow 127 and in the opposite direction by an armature 126 that is oscillated and displaced by an electromagnet 125. Here, the card 101 has only one end locked by the movable contacts 103a and 104a of the contacts 103 and 104, and the engaging portion with the armature 106 on the other end has a simple hook structure. That is, as shown by the relay 100 in FIG. 11, the engaging claws 101c to 106c are formed at the tips of the movable contacts 101a to 106a, and the engaging claws 101c to 106c are the peripheral edges of the engaging holes 101b to 106b. It is locked to the part.

  Therefore, in the case of 6 poles or 4 poles as shown in FIG. 11, the cards 107 locked by the locking claws 101c to 106c are held on the surface to prevent the card 107 from being removed. When the minimum contact configuration of 1a1b is used, such as 14 relays 120, the movable contacts 123a and 124a are arranged on a substantially straight line, and the card 121 can be held only on the substantially straight line, that is, in a rectangular short direction. The card 121 may be disengaged on the side of the armature 126 as shown by reference numeral 128 in FIG. 12 due to impact or vibration during operation.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an electromagnetic relay capable of preventing a card from being removed and improving reliability even with the minimum contact configuration in a safety relay, and a control device using the same. is there.

  In the electromagnetic relay of the present invention, an armature is oscillated and displaced by an electromagnet, the oscillating displacement is converted into a slide displacement of the card by a card that engages the armature, and a movable contact that is locked to the card. The contact state is switched by contacting or separating from the fixed contact, and the set of the movable contact and the fixed contact is arranged on each side of the center line of the card extending in the sliding direction of the card, and the set In an electromagnetic relay having a normally open contact and a normally closed contact in which contact states are opposite to each other, a return spring is provided between the armature and the movable contact and is locked to the card. To do.

  According to said structure, it implement | achieves as what is called a safety relay etc., and is provided with the normally open and normally closed which will be in a mutually reverse contact state, ie, one set of a and b contacts, and each said contact is mutually opposed The movable contact is locked to a card that is composed of a fixed contact and a movable contact and is slid and displaced by an armature driven by an electromagnet, so that the movable contact is bent and deformed to contact or separate from the fixed contact. In the electromagnetic relay in which the contacts of the set are arranged on each side of the center line of the card extending in the sliding direction of the card, for example, a set of two or three rows of contacts is provided in the sliding direction like 3a1b and 5a1b. In the case where the card is held by the set of movable contacts, the card is held on the surface to prevent the card from being pulled out, whereas the minimum 1a1b contact configuration is used. Can only be held in a substantially straight line, there is a possibility that the engagement of the card is free in the armature side. Therefore, in the present invention, when a return spring is provided between the armature and the movable contact to urge the card in the return direction when the electromagnet is not excited, the return spring is locked to the card.

  Therefore, even if the safety relay has the minimum contact configuration, the card can be prevented from being detached and the reliability can be improved.

  In the electromagnetic relay of the present invention, the return spring is locked to the card by a protrusion formed at the tip of the return spring being locked to the peripheral edge of the card lock hole by sheet metal processing. It is characterized by that.

  According to said structure, it is set as the structure which provides the protrusion formed by sheet-metal processing in the card | curd fitting part of the return spring which consists of a plate-shaped body which has elasticity.

  Therefore, prevention of card removal can be realized with a simple structure.

  Furthermore, in the electromagnetic relay of the present invention, a slit is formed in the vicinity of the protrusion.

  According to said structure, by providing a slit in the vicinity of the said protrusion, the spring property is obtained for this return spring at the time of insertion in a card | curd, card | curd scraping can be suppressed and generation | occurrence | production of dust can be suppressed.

  In the electromagnetic relay of the present invention, the protrusion is a rib extending in a direction orthogonal to the insertion direction of the card into the locking hole.

  According to the above configuration, the protrusion is formed by the sheet metal processing and is a rib extending in a direction orthogonal to the insertion direction of the card into the locking hole, so that the contact with the inner peripheral surface and the surface of the locking hole is achieved. This is advantageous for card scraping. Moreover, shape formation becomes easy and a shape is stabilized.

  Furthermore, in the electromagnetic relay of the present invention, the return spring is locked to the card by dividing the tip of the return spring into a plurality of parts by sheet metal processing, and the divided parts are arranged in a staggered manner. It implement | achieves by latching to the peripheral part of a stop hole.

  According to said structure, it is set as the structure which divided the card | curd fitting part of the return spring which consists of a plate-shaped body which has elasticity into a plurality by sheet-metal processing, and the divided part was staggered.

  Therefore, prevention of card removal can be realized with a simple structure.

  Further, in the electromagnetic relay of the present invention, the plurality of divided portions realize the staggered arrangement by a straight portion and a step formed by bending, and the step is bent in a direction opposite to a mold drawing direction. It is formed.

  According to said structure, when implement | achieving the level | step difference which implement | achieves the said staggered arrangement | sequence by the said sheet metal process, the extraction direction of a metal mold | die is designated and a level | step difference is bent and formed in the direction opposite to the said extraction direction.

  Therefore, burrs generated in the sheet metal processing can be generated inside the staggered side on the bending side, and card scraping can be suppressed and generation of dust can be suppressed.

  Furthermore, the control device of the present invention uses the above-described electromagnetic relay.

  According to said structure, even if it uses a small relay for the control apparatus which controls a machine tool, a line, etc., reliability can be improved.

  As described above, the electromagnetic relay of the present invention is realized as a so-called safety relay or the like, and has a minimum number of contacts of 1a1b and is driven by a common card. When a return spring is provided between the contact and the card to bias the card in the return direction when the electromagnet is not excited, the return spring is locked to the card.

  Therefore, even with the minimum contact configuration, the card can be prevented from being detached, and the reliability can be improved.

  Furthermore, the control device of the present invention uses the electromagnetic relay as described above.

  Therefore, even if a small relay is used as a control device for controlling a machine tool or a line, the reliability can be improved.

1 is an exploded perspective view of an electromagnetic relay according to an embodiment of the present invention. It is a perspective view which shows the assembly state of FIG. FIG. 3 is a plan view of FIG. 2. It is a longitudinal cross-sectional view for demonstrating operation | movement of the said electromagnetic relay. It is a figure which expands and shows the front-end | tip part of the return spring in the electromagnetic relay of one Embodiment of this invention, and the return spring hole vicinity of the card | curd latching on it. It is a figure which expands and shows the front-end | tip part of the return spring in the electromagnetic relay of one Embodiment of this invention, and the return spring hole vicinity of the card | curd latching on it. It is a perspective view of a part of a return spring in an electromagnetic relay according to another embodiment of the present invention. It is a perspective view of a part of a return spring in an electromagnetic relay according to still another embodiment of the present invention. It is a perspective view of a part of a return spring in an electromagnetic relay according to still another embodiment of the present invention. FIG. 10 is an enlarged cross-sectional view showing the tip of the return spring of FIG. 9 and the vicinity of the return spring hole of a card locked to the return spring. 1 is a longitudinal cross-sectional view of a typical prior art relay. It is a longitudinal cross-sectional view of the relay of another prior art. FIG. 13 is a horizontal sectional view of FIG. 12. It is the longitudinal cross-sectional view seen from the cut surface line XIV-XIV of FIG. 12 and FIG.

(Embodiment 1)
Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. In the following description, the vertical direction will be described with reference to FIG. 1 is an exploded perspective view of an electromagnetic relay 1 according to an embodiment of the present invention, FIG. 2 is a perspective view showing an assembled state thereof, and FIG. 3 is a plan view of FIG. The basic structure of the electromagnetic relay 1 is similar to that of the above-described Patent Document 3, that is, the relay 100 shown in FIG. A, but FIG. A has a contact configuration of 4a2b as described above. The configuration is a safety relay with a minimum contact configuration, which includes one a (normally open: NO) contact 2 and one b (normally closed: NC) contact 3. Hereinafter, for the sake of convenience, the arrangement direction of the contacts 2 and 3 is defined as the left-right direction. The electromagnetic relay 1 generally includes a body 4, an electromagnet block 5, an armature block 6, a return spring 7, a card 8, a cover 9, and the contacts 2 and 3. .

  The body 4 is made of a molded product such as PBT having insulating properties and flame retardancy, and has a longitudinal base 41 on which one end of the electromagnet block 5 is mounted, and a pair standing upright at a substantially central portion of the base 41. Side walls 42, 43, a connecting member 44 that connects and reinforces the side walls 42, 43 to the electromagnet block 5 side, an insulating partition 45 that connects the side walls 2, 43 to the contacts 2, 3 side, and the insulating partition 45 is provided with an insulating partition wall 46 extending from the center of 45 and partitioning the contacts 2 and 3, and a terminal block 47 for holding the contacts 2 and 3 on the other end side of the base 41. The armature block 6 and the return spring 7 are accommodated in a region defined by the side walls 42 and 43 and the insulating partition wall 45, and the terminals 21 and 22; And the card 8 slides and displaces on the insulating partition wall 45.

  FIG. 4 is a longitudinal sectional view of the electromagnetic relay 1. The cover 9 is omitted. According to FIG. 4, the structures of the electromagnet block 5 and the armature block 6 are clear. According to this, the electromagnet block 5 includes a coil 51, a spool 52 around which the coil 51 is wound, an iron core 53 having a substantially L-shaped yoke 54, 55 inserted into the center hole of the spool 52, A pair of coil terminals 56 erected on a flange portion 52a on the lower side of the spool 52 are provided. Each end of the coil 51 is connected to the upper side of each coil terminal 56, and the lower side is press-fitted into the base 41 and protrudes to the outside as a terminal.

  The armature block 6 includes a sub-card 61 made of a plastic product, a movable plate 62 made of soft iron, and a permanent magnet 63 having a rectangular parallelepiped shape. The movable plate 62 is formed in a rectangular flat plate shape and bonded to the sub card 61. The permanent magnet 63 is fixed to the surface of the movable plate 62. As shown in FIG. 1 and FIG. 2, a pair of pins 64 are erected on both the left and right side surfaces of the sub card 61, and these pins 64 fit into holes 48 formed in the side walls 42 and 43 of the base 41, respectively. Thus, the armature block 6 is held so as to be swingable and displaceable in the arrow 69 and the opposite direction. When the armature block 6 is attached to the base 41, the upper end portion of the movable plate 62 faces the upper yoke 54 of the electromagnet block 5 and the lower end portion faces the lower yoke 55 of the electromagnet block 5. A tongue piece 65 extends from the upper end portion of the sub card 61, and the tongue piece 65 engages with an engagement hole 81 formed in the card 8. Displacement driving in the opposite direction is possible.

  The return spring 7 is formed in a substantially Y shape as shown in FIG. 1 by punching and bending a thin metal plate having elasticity, and a lower end 71 whose rigidity is increased by folding (overlapping) is shown in FIG. As shown in FIG. 4, the base 41 is press-fitted between the armature block 6 and the insulating partition 45, and the tip portions 75 and 76 of the bifurcated upper end portions 73 and 74 are inserted into the return spring holes 83 and 84 of the card 8. Thus, the card 8 is elastically biased in the direction opposite to the arrow 82 and so as not to cause rotation in the yaw direction indicated by the arrow 85 and the opposite direction. The lower end 71 is formed with protrusions 71 a and 71 b for preventing the base 41 from coming off.

  The contacts 2 and 3 include a pair of fixed contact terminals 21 and 31 and movable contact terminals 22 and 32. These terminals 21, 22; 31, 32 are formed by punching a thin metal plate having elasticity and bent in a crank shape in a side view, and are movable among the bent parts 21 a, 22 a; 31 a, 32 a. The contact terminals 22 and 32 are doubled by folding the metal plate in order to increase rigidity. Then, on the other end side of the base 41, the bent portions 21a, 22a; 31a, 32a are press-fitted into mounting grooves 49 formed on both sides, and further fixed with an adhesive, whereby the terminals 21, 22 are inserted. The rotation of the arrows 32 and 32 in the yaw direction opposite thereto is restrained, and they are implanted so as to face each other in parallel. The lower ends 21b, 22b; 31b, 32b of these terminals 21, 22; 31, 32 become relay terminals by projecting from the base 41, and the upper arms 21c, 22c; 31c, 32c having elasticity The contact members 21d, 22d; 31d, 32d are fixed by caulking.

  In order to give the fixed contact terminals 21 and 31 rigidity, ribs 21e and 31e are formed in the lower portions of the contact members 21d and 31d in the upper arm portions 21c and 22c. These contact members 21d, 22d; 31d, 32d are configured to be in contact with each other in a substantially parallel manner by generating a deflection due to the pressing of 32 at the base end portion on the base 41 side. On the other hand, in the upper arm portions 22c and 32c of the movable contact terminals 22 and 32, slits 22e and 32e are formed in the portion on the base 41 side so that they are easily bent. The slits 22e and 32e need not be provided. And in the storage space of the contacts 2 and 3 partitioned by the insulating partition wall 46, the contact members 21d and 22d; 31d and 32d that are in contact with each other are opened (separated), and the contact gap is 0.5 mm at the time of welding. In order to ensure the above, and in order to prevent a short circuit when the return spring 7 is broken, an insulating partition 40 for separation is provided upright from the base 41 between the terminals 21, 22;

  When the coil 51 is not energized, the card 8 is displaced in the direction of the electromagnet block 5, that is, in the direction opposite to the arrow 82 by the elastic force of the return spring 7. The fixed contact terminal 21 and the movable contact terminal 32, and the movable contact terminal 22 and the fixed contact terminal 31 are disposed on a line that is displaced and orthogonal to the sliding direction. In addition, on the b (normally closed: NC) contact 3 side, the fixed contact terminal 31 is arranged inward and the movable contact terminal 32 is arranged on the outside, and on the contrary, on the a (normally open: NO) contact 2 side, it is movable. The contact terminal 22 is disposed inward and the fixed contact terminal 21 is disposed outward, and the distal ends of the upper arm portions 22c and 32c of the movable contact terminals 22 and 32 are engaged with the engagement holes 86 and 87 of the card 8. Tongue pieces 22f and 32f. Projections 22g and 32g are formed on the tongue pieces 22f and 32f. Correspondingly, projections 86a, 86b and 86c; 87a, 87b and 87c are formed in the locking holes 86 and 87; Retaining is performed.

  The card 8 is generally formed in a U-shape, and the engagement hole 81 and the pair of left and right return spring holes 83 and 84 for the sub card 61 are connected to the U-shaped connecting portion 80 in a pair of left and right. The locking holes 86 and 87 are formed on the U-shaped arm portions 88 and 89 side. As described above, the card 8 is mounted and supported by the tongue piece 65 of the sub card 61, the tip portions 75 and 76 of the return spring 7, and the tongue pieces 22f and 32f of the movable contact terminals 22 and 32. And the height of the upper end surface 45a of the insulating partition 45 is a droop formed from the inner facing surfaces 88c, 89c of the arm portions 88, 89 so as not to come into contact with the back surfaces on the base end side of the arm portions 88, 89. The height of the step surface 46a formed on the upper end side of the insulating partition wall 46 is set so as not to contact the lower end surfaces 88b and 89b of the pieces 88a and 89a.

  Further, the following two points are performed as the guide for the slide displacement. First, the upper end portion 46b of the insulating partition wall 46 is sandwiched between the hanging pieces 88a and 89a, and is formed by hanging from the top plate 91 of the cover 9 between the inner facing surfaces 88c and 89c of the arm portions 88 and 89. The guide 91a is sandwiched. Next, the lower end surface 91b of the guide 91a fits into stepped portions 88d and 89d generated by forming the hanging pieces 88a and 89a on the inner facing surfaces 88c and 89c of the arm portions 88 and 89, respectively.

  The cover 9 is made of a resin molded product such as transparent polycarbonate, and is formed in a box shape with an open bottom so that the open / close state of the contact members 21d, 22d; 31d, 32d can be confirmed, and is shown in FIG. The parts are put on the body 4 in an assembled state from above, and the inner peripheral surface at the lower end is bonded to the base 41.

  In the electromagnetic relay 1 configured as described above, when the coil 51 is in a non-energized state, as shown in FIGS. 2, 3, and 4 (a), the contact force is generated by the elastic force of the return spring 7 through the card 8. The pole block 6 is biased in the direction of the arrow 69, whereby the card 8 is slid in the direction opposite to the direction of the arrow 82, that is, the electromagnet block 5, and the movable contact terminal that is hooked by the card 8. 22 and 32 are also bent and deformed in the direction opposite to the direction of the arrow 82, that is, the electromagnet block 5 side. As a result, the b (NC) contact 3 side is conducted and the a (NO) contact 2 side is shut off.

  In contrast, in the energized state of the coil 51, the armature block 6 is opposite to the direction of the arrow 69 against the elastic force of the return spring 7 via the card 8, as shown in FIG. The card 8 is slid in the direction of the arrow 82, that is, opposite to the electromagnet block 5, and the movable contact terminals 22 and 32 hooked by the card 8 are also in the direction of the arrow 82. That is, it is bent and deformed on the side opposite to the electromagnet block 5. As a result, the b (NC) contact 3 side is cut off and the a (NO) contact 2 side is conducted.

  It should be noted that in the electromagnetic relay 1 of the present embodiment, protrusions 75a and 76a are formed at the tip portions 75 and 76 of the return spring 7 described above, respectively, and the return spring holes 83 and 84 have the Protrusions 83a, 83b, 83c; 84a, 84b, 84c that contact the tip portions 75, 76 in the thickness direction are formed to serve as locking holes. FIG. 5 is an enlarged view of the vicinity of the tip portion 76 and the return spring hole 84, (a) is a perspective view of the tip portion 76, and (b) is a plane near the tip portion 76 and the return spring hole 84. FIG. FIG. 5 shows the vicinity of the tip 76 and the return spring hole 84, but the same applies to the other tip 75 and the return spring hole 83. As described above, the return spring 7 is formed by punching and bending a thin metal plate having elasticity, and the protrusions 75a and 76a are formed by processing the sheet metal.

  With this configuration, the card is realized as a so-called safety relay, etc., which is driven by a common card 8 and is in a normally open and normally closed state in which contact states are opposite to each other. In the electromagnetic relay disposed on each side of the center line 8x of the card 8 extending in the sliding direction 82, the contact points 2 and 3 of the a and b are set to the minimum configuration of one set. Using the return spring 7 provided between the pole 6 and the movable contacts 22 and 32, the card 8 is engaged with the return spring 7 by the projections 75a and 76a and the projections 83a, 83b and 83c; 84a, 84b and 84c. Can be stopped.

  Therefore, one end of the card 8 is locked by the tongues 22f and 32f of the upper arm portions 22c and 32c of the movable contact terminals 22 and 32, and the other end is locked by the tip 76 of the return spring 7, so that FIG. The card 8 can be prevented from coming off as indicated by reference numeral 68 in FIG. In this way, even in the safety relay, even with the minimum contact configuration of 1a1b, the card 8 can be prevented from being detached, and the reliability can be improved.

  Further, the locking of the return spring 7 to the card 8 is formed in the locking holes 83 and 84 of the card 8 by projections 75a and 76a formed at the tip portions 75 and 76 of the return spring 7 by sheet metal processing. Since this is realized by locking the protrusions 83a and 84a, the structure for preventing the card 8 from coming off can be realized with a simple structure.

  In the example described above, the number of the protrusions 75a and 76a is one, but two may be provided as shown in FIG. FIGS. 6A and 6B correspond to FIGS. 5A and 5B, respectively. That is, in the return spring 7 of FIG. 5, the protrusions 75a and 76a are locked to the protrusions 83a and 84a, but in the return spring 7a of FIG. 6, the protrusions 76b and 76c formed on the tip 76 are locked. The projections 84b and 84c formed on the other surface of the hole 84 are engaged with each other.

(Embodiment 2)
FIGS. 7A and 7B are perspective views of a part of return springs 7b and 7c in an electromagnetic relay according to another embodiment of the present invention. These return springs 7b and 7c are similar to the return spring 7 shown in FIG. 5 (a) and the return spring 7a shown in FIG. 6 (a), respectively, and corresponding portions are denoted by the same reference numerals. The description is omitted. It should be noted that in these return springs 7b and 7c, a slit 77 is formed in the vicinity of the protrusions 76a and 76b and 76.

  With such a configuration, when the end portions 75 and 76 are inserted into the locking holes 83 and 84 of the card 8, the return springs 7b and 7c are provided with spring properties, and the card 8 is prevented from being scraped and dust. Can be suppressed.

(Embodiment 3)
FIGS. 8A and 8B are perspective views of a part of return springs 7d and 7e in an electromagnetic relay according to still another embodiment of the present invention. These return springs 7d and 7e are similar to the return springs 7b and 7c shown in FIGS. 7A and 7B, respectively, and corresponding portions are denoted by the same reference numerals and description thereof is omitted. . It should be noted that in these return springs 7 d and 7 e, the protrusions 76 d and 76 e are formed of ribs extending in a direction orthogonal to the insertion direction 78 into the locking hole 84 of the card 8.

  With this configuration, the protrusions 76d and 76e come into contact with the protrusions 84a and 84b and 84c formed on the inner peripheral surface of the locking hole 84, which is advantageous for scraping the card 8. Moreover, shape formation becomes easy and a shape is stabilized.

(Embodiment 4)
FIGS. 9A and 9B are perspective views of a part of return springs 7f and 7g in an electromagnetic relay according to still another embodiment of the present invention. These return springs 7f and 7g are similar to the return springs 7d and 7e shown in FIGS. 8A and 8B, respectively. Corresponding portions are denoted by the same reference numerals, and description thereof is omitted. . It should be noted that the return springs 7f and 7g are divided into a plurality of tip portions 76 of the return springs 7f and 7g by the formation of the slits 77 by sheet metal processing, and the divided portions are staggered. Thus, one row side of the staggered pattern becomes the protrusions 76f and 76g. With this configuration, the card 8 can be prevented from coming off with a simple structure.

  It should also be noted that in these return springs 7f and 7g, the plurality of divided portions realize the staggered arrangement by linear portions 76h and 76i and steps 76j and 76k formed by bending, and the steps 76j , 76k are bent in the direction opposite to the mold drawing direction 78. In this way, by designating the die punching direction 78 and bending the steps 76j and 76k in the direction opposite to the punching direction 78, the burr generated in the sheet metal working is indicated by reference numeral 79 in FIG. And can be generated inside the zigzag on the projection 76f side to be bent. Therefore, the card 8 can be prevented from being scraped against the insertion of the projection 76f and the straight portion 76h in the direction of the arrow 78, and the generation of dust can be suppressed.

  By using such a safety relay for a control device that controls a machine tool, a line, etc., reliability can be improved even if a small relay is used.

DESCRIPTION OF SYMBOLS 1 Electromagnetic relay 2 a (normally open: NO) contact 3 b (normally closed: NC) contact 21, 31 Fixed contact terminal 22, 32 Movable contact terminal 21c, 22c; 31c, 32c Upper arm part 21d, 22d; 31d, 32d Contact Member 21e, 31e Rib 22f, 32f Tongue piece 22g, 32g Protrusion 4 Body 40, 45, 46 Insulating partition 41 Base 47 Terminal block 5 Electromagnet block 51 Coil 52 Spool 53 Iron core 54, 55 Yoke 6 Armature block 61 Sub card 62 Movable Plate 63 Permanent magnet 65 Tongue piece 7, 7a, 7b, 7c; 7d, 7e; 7f, 7g Return spring 71 Lower end 73, 74 Upper end 75, 76 End 75a, 76a, 76b, 76c; 76d, 76e; , 76g Protrusions 76h, 76i Straight portions 76j, 76k Step 77 Slit 78 Die removal direction 8 Card 80 connecting part 81 engaging hole 83, 84 return spring hole 83a, 83b, 83c; 84a, 84b, 84c protrusion 86, 87 locking hole 88, 89 arm part 88a, 89a hanging piece 9 cover 91 top plate 91a guide

Claims (7)

The armature is oscillated and displaced by the electromagnet, and the oscillating displacement is converted into a slide displacement of the card by the card that engages the armature, and the movable contact that is locked to the card contacts or separates from the fixed contact. In this manner, the contact state is switched, and one set of the movable contact and the fixed contact is arranged on each side of the center line of the card extending in the sliding direction of the card, and the set is in a contact state opposite to each other. In an electromagnetic relay with normally open and normally closed contacts
An electromagnetic relay comprising: a return spring provided between the armature and the movable contact and locked to the card.   2. The locking of the return spring to the card is realized by a protrusion formed at the tip of the return spring being locked to the peripheral edge of the locking hole of the card by sheet metal processing. Electromagnetic relay.   The electromagnetic relay according to claim 2, wherein a slit is formed in the vicinity of the protrusion.   The electromagnetic relay according to claim 2, wherein the protrusion is a rib extending in a direction orthogonal to a direction in which the card is inserted into the locking hole.   The return spring is locked to the card by cutting the return spring into a plurality of parts by sheet metal processing, and the divided parts are arranged in a staggered manner, and each divided part is locked to the peripheral edge of the card locking hole. The electromagnetic relay according to claim 1, which is realized by the following.   The plurality of divided portions realize the staggered arrangement by a straight portion and a step formed by bending, and the step is bent in a direction opposite to a mold drawing direction. The electromagnetic relay according to claim 5.   The electromagnetic relay of any one of the said Claims 1-6 is used, The control apparatus characterized by the above-mentioned.

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