Patent Description:
A certain aspect of the embodiments is related to a relay.

In a relay (electromagnetic relay), a current flows through a coil to open and close contacts. There is a hinge-shaped relay which has a yoke connected to an iron core and an armature movable relative to the yoke.

In recent years, relays are increasingly used for applications, such as mounting on electric vehicles, in which the relay is susceptible to shock and vibration. In order to prevent the amateur from being displaced relative to the yoke when a large impact or vibration is applied to the relay, a technique to make the armature rotatable relative to the yoke is well known, in which one of the yoke or the amateur is provided with a shaft, and the other is provided with a bearing which rotatably receives the shaft.

A relay is well known in which a groove for holding a contact is formed on the lateral side of a substrate, the contact is inserted into the groove so as to be engaged and held by the groove, and then the periphery of an extended portion of an external terminal is sealed with an adhesive. Further, a terminal block is well known in which a groove opened in a body for attaching a component is provided, a terminal, etc., is inserted from the opening and attached to the body, and a lid plate covering the opening is attached to the body.

Document <CIT> discloses relay comprising an electromagnet; a yoke; a movable contact part having an armature configured to operate corresponding to an activation of the electromagnet, a movable spring attached to the armature, and a movable contact attached to the movable spring; and a fixed contact part having a base to which a fixed contact opposed to the movable contact is attached, wherein the base has a leg extending in a contact/separation direction between the fixed contact and the movable contact, the leg contacts the yoke, and the leg positioned above the armature and is spaced away from an upper part of the armature.

One aspect of the present disclosure is a relay according to claim <NUM>.

In many relays, a leaf spring and/or a coil spring are used to generate an appropriate contact force and a disengagement force for opening and closing contacts. When such a relay is used for an application in which the relay is susceptible to impact or vibration, the spring may be plastically deformed by the impact, and an appropriate contact force or an appropriate opening force may not be obtained. On the other hand, if a reinforcing member, etc., for withstanding an impact is separately provided, the relay assembly work becomes complicated and may lead to an increase in cost.

Hereinafter, a description will be given of the present embodiment of the present invention with reference to the drawings.

<FIG> are assembling and exploded perspective views of a relay <NUM> according to an embodiment, respectively. For example, the relay <NUM> is a relay for in-vehicle electrical equipment used in an electric vehicle. The relay <NUM> is a hinge type relay including a fixed contact part <NUM> having a fixed contact <NUM> (<FIG>), a movable contact part <NUM> having a movable contact <NUM>, an electromagnet <NUM> configured to displace the movable contact <NUM> relative to the fixed contact <NUM> so that the movable contact <NUM> can come into contact or move away from the fixed contact <NUM>, and a case <NUM> configured to contain the movable contact part <NUM> and the electromagnet <NUM>. The relay <NUM> is mounted on a printed circuit board (not shown), etc., using a metal collar <NUM> attached to the outside of the case <NUM> by caulking, etc. The fixed contact portion <NUM> and the movable contact portion <NUM> are collectively referred to as a "contact part".

As shown in <FIG>, the movable contact part <NUM> and the electromagnet <NUM> (collectively referred to as a "main body <NUM>") may be moved relative to the case <NUM> along a contact/separation direction (a left-right direction in <FIG>) between the fixed contact <NUM> and the movable contact <NUM>, whereby the main body <NUM> is inserted and incorporated into the case <NUM>. The case <NUM> can have a structure which opens only in the contact/separation direction, and it is not necessary to combine two parts divided in the vertical direction, for example. The fixed contact part <NUM> includes a base <NUM> and the fixed contact <NUM> provided on the base <NUM>. By inserting the fixed contact part <NUM> into the case <NUM>, a back surface of the fixed contact part <NUM> constitutes a lid of the relay <NUM>. The relay <NUM> is sealed by filling a boundary between the fixed contact part <NUM> and the case <NUM> with a resin or an adhesive. The case <NUM> can be manufactured, for example, from resin molding. By forming the case <NUM> as described above, the number of components can be reduced and the manufacturing cost can be reduced.

<FIG> are perspective and front views of the inside of the case <NUM>, respectively. The case <NUM> has ribs <NUM> and <NUM> configured to guide and locate the main body <NUM> at a predetermined position in the case <NUM>. Each rib extends in the contact/separation direction of the contacts, and also in the mounting direction of the main body <NUM> to the case <NUM>.

<FIG> is a cross-sectional view showing a positional relationship between an armature <NUM>, a yoke <NUM> and each rib when the electromagnet <NUM> is positioned in the case <NUM>. The rib <NUM> formed on an inner bottom surface of the case <NUM> contacts a lower surface of the yoke <NUM> to support the movable contact part <NUM>, and contributes to the vertical positioning of the movable contact part <NUM>. The rib <NUM> formed on an inner side surface of the case <NUM> has a surface <NUM> inclined in the insertion direction of the main body <NUM>. The surface <NUM> functions as a guide in the width direction of the yoke <NUM> when the main body <NUM> is inserted into the case <NUM>. The rib <NUM> contacts the side surface of the yoke <NUM> after the main body <NUM> is inserted, and contributes to the positioning of the electromagnet <NUM> relative to the case <NUM> in the width direction.

A rib <NUM> formed on an upper surface of the case <NUM> is arranged spaced away from the armature <NUM> in the vertical direction, so that the rib does not come into contact with the armature <NUM> in normal operation. Further, even if the armature <NUM> jumps up beyond the movable range when the vehicle on which the relay <NUM> is mounted receives a strong impact, the movement of the armature <NUM> is limited by the rib <NUM>, whereby a large force is prevented from being applied to the contact and/or a return spring described later. By providing the rib <NUM>, damage to each part and/or plastic deformation of the spring can be avoided.

<FIG> shows the back side of the case <NUM> opposite to an opening into which the main body <NUM> is inserted. As shown in <FIG> and <FIG>, the electromagnet <NUM> has two coil terminals <NUM> for supplying power to a coil <NUM>. The coil terminals <NUM> are inserted into an opening <NUM> inside the case <NUM>, and are exposed to the outside of the case <NUM> through an opening <NUM> formed on the back surface of the case <NUM>. The opening <NUM> has a space for routing electric wires <NUM> and <NUM> respectively connected to the two coil terminals <NUM>. After being introduced into a pocket <NUM> formed on the outer side of the case <NUM>, the electric wires <NUM> and <NUM> are drawn out from an opening <NUM> above the pocket <NUM>, and are electrically connected to a printed circuit board, etc., on which the relay <NUM> is mounted.

<FIG> shows a state in which the electric wires <NUM> and <NUM> are drawn out from the opening <NUM> and then the opening <NUM> is filled with a resin or an adhesive <NUM> and sealed. As shown in <FIG>, the electric wires <NUM>, <NUM> or related members do not protrude from the back surface of the case <NUM>, and the size of the relay in the contact/separation direction of the contacts can be reduced. It is preferable that the case <NUM> be provided with an air hole <NUM> in order to discharge the air expanded inside the case <NUM> when a thermosetting resin or adhesive is used. It is preferable that the air hole <NUM> be sealed with a resin, etc., after the opening <NUM> is sealed.

<FIG> is an exploded perspective view of the contact part. The fixed contact part <NUM> has at least one (two in <FIG>) fixed terminals <NUM>, each provided with a fixed contact <NUM>, and a frame-shaped or box-shaped base <NUM> to which the fixed terminal <NUM> is attached. A resin or an adhesive is filled between the fixed terminal <NUM> and the base <NUM> to seal a gap therebetween. The base <NUM> is manufactured, for example, by resin molding. A permanent magnet <NUM> and a permanent magnet yoke <NUM> are attached to the outer surface of the base <NUM>, and an arc-extinguishing plate <NUM> for extinguishing an arc is inserted into the base <NUM>, which will be described later.

The movable contact part <NUM> has a conductive plate <NUM> to which the movable contact <NUM> is attached by caulking, etc., a movable spring <NUM> to which the conductive plate <NUM> is attached, and the armature <NUM> to which the movable spring <NUM> is attached by a rivet <NUM>, etc..

<FIG> is an exploded perspective view of the electromagnet <NUM>. The electromagnet <NUM> has a bobbin <NUM>, an iron core <NUM> positioned in the bobbin <NUM>, a coil <NUM> wound around the bobbin <NUM>, a substantially L-shaped yoke <NUM> to which a lower end of the iron core <NUM> is connected, and a post <NUM> attached to the yoke <NUM>. The bobbin <NUM> has a terminal port <NUM> into which the coil terminal <NUM> is inserted, and a current flows through the coil <NUM> via the electric wires <NUM>, <NUM> and the coil terminals <NUM>. The armature <NUM> is swingably supported relative to the yoke <NUM>. As will be described later, the movable spring <NUM> and the post <NUM> are connected via the return spring <NUM> so as to be elastically displaceable relative to each other.

<FIG> are a top view and a side view of the contact part, respectively, and <FIG> is a perspective view of the base <NUM>. The base <NUM> has a leg <NUM> extending in the mounting direction of the main body to the case <NUM>. <FIG> is a cross-sectional view along a B-B' line of <FIG>. As shown in a part "A" of <FIG>, an end surface of the leg <NUM> is configured to come into contact with the yoke <NUM> when the base <NUM> is incorporated into the case <NUM>. Therefore, the positional relationship of the contacts between the fixed contact part <NUM> and the electromagnet <NUM> in the contact/separation direction is uniquely determined, and thus each component in the case <NUM> can be accurately positioned.

As shown in <FIG>, the leg <NUM> is positioned above the armature <NUM> so as to be separated from the armature <NUM> by a certain distance. This distance is determined so that the upper surface of the armature <NUM> does not come into contact with the lower surface of the leg <NUM> in the normal operation of the armature <NUM>, but the upper surface of the armature <NUM> comes into contact with the lower surface of the leg <NUM> when the armature <NUM> jumps up beyond the movable range thereof due to, for example, a strong impact applied to the vehicle on which the relay <NUM> is mounted. Since a conventional relay does not include a member which suppresses a large displacement of the armature <NUM> due to the lifting thereof, etc., a large force may be applied to the return spring <NUM> in the extending direction thereof due to the displacement of the armature <NUM>, whereby the return spring <NUM> may be plastically deformed. In the embodiment, by virtue of the leg <NUM>, the movement of the armature <NUM> beyond the movable range is limited, the force applied to the contacts and the return spring <NUM> is reduced, and the plastic deformation of the return spring <NUM> is also prevented. The leg <NUM> not only improves the positioning accuracy between the fixed contact part <NUM> and the electromagnet <NUM>, but also prevents damage and plastic deformation of each component due to the impact, etc. The leg <NUM> can be integrally formed with the base <NUM> by resin molding, etc., and thus the number of components does not increase.

<FIG> is a side sectional view of the main body <NUM>, <FIG> are perspective views of examples of the post <NUM> and the movable spring <NUM>, respectively. Although the return spring <NUM> in <FIG> is a coil spring, it may be formed by a leaf spring, etc. One end of the return spring <NUM> is engaged with and held by a recess <NUM> formed at a root of a front end <NUM> of the post <NUM> fixed to the yoke <NUM>, the front end <NUM> being arranged at the center of the post <NUM> in the width direction thereof. The other end of the return spring <NUM> is engaged with and held in a recess <NUM> at a root of a protrusion <NUM> formed on the movable spring <NUM>. When the electromagnet <NUM> is off, the urging force of the return spring <NUM> causes the armature <NUM> to tilt away from the iron core <NUM>, and the movable contact <NUM> separates from the fixed contact <NUM>. On the other hand, as shown in <FIG>, when the electromagnet <NUM> is on, the armature <NUM> is displaced toward the iron core <NUM> by the magnetic force against the urging force of the return spring <NUM>, and the movable contact <NUM> comes into contact with the fixed contact <NUM>.

When a strong impact and/or external force is applied to the relay <NUM> in the contact/separation direction of the movable contact <NUM> (the left-right direction in <FIG>), the movable contact <NUM> and the conductive plate <NUM> are largely displaced toward the yoke <NUM>, whereby the movable spring <NUM> may be plastically deformed. In the embodiment, this problem can be prevented by extending the front end <NUM> closer to the movable contact than the yoke <NUM> with respect to the contact/separation direction of the contacts. Even if the movable contact <NUM> is displaced toward the yoke <NUM> due to the impact, etc., the movable spring <NUM> or the conductive plate <NUM> abuts on the front end <NUM> to limit further displacement of the movable spring <NUM>, whereby damage or plastic deformation of the movable spring <NUM> can be prevented. Since the front end <NUM> is provided on the post to which the return spring is attached, it is not necessary to provide a separate member for limiting the displacement of the movable spring, and thus the number of components can be reduced.

When one end of the return spring is directly engaged with the yoke <NUM>, no member intervenes between the conductive plate and the yoke, and thus it is not possible to prevent the conductive plate from being largely displaced toward the yoke. Since the post <NUM> according to the embodiment has the front end <NUM> which holds the return spring <NUM> and limits the displacement of the conductive plate <NUM> in the left-right direction, plastic deformation, etc., of the movable spring <NUM> due to a large external force is prevented.

When downsizing of the relay is required, it is preferable that the distance between the yoke <NUM> and the conductive plate <NUM> be short. In the embodiment, as shown in <FIG> or <FIG>, a recess or opening <NUM> is formed in the yoke <NUM> so that a portion of the post <NUM> is positioned in the opening <NUM>. As shown in <FIG>, the post <NUM> has a base portion <NUM> fixed to the yoke <NUM>, a first bent portion <NUM> which bends in a direction extending from the base portion <NUM> into the opening <NUM>, and a second bent portion <NUM> extending from the first bent portion <NUM> which bends in a direction opposite to the bending direction of the first bent portion <NUM>. The front end <NUM> is provided to the second bent portion <NUM>. By positioning the portion of the post <NUM> in the opening <NUM>, the extending distance of the post <NUM> from the yoke <NUM> to the movable contact <NUM> can be minimized, whereby the relay can be downsized. Since the post <NUM> has two bent portions <NUM> and <NUM> which bend in the opposite directions, the post <NUM> can be elastically deformed in the contact/separation direction of the contacts, whereby damage or plastic deformation of the post <NUM> is prevented.

When a vibration with a frequency equal to the natural frequency of the moving part is applied to the relay, resonance of the moving part may occur. For example, when a vibration with a frequency equal to the natural frequency of the movable contact portion <NUM> is applied to the relay <NUM>, the movable contact <NUM> and the fixed contact <NUM> resonate in the contact/separation direction, whereby and the movable contact <NUM> may unintentionally come into contact with the fixed contact <NUM>. In such a case, there is a risk of malfunction of the relay <NUM>.

In the embodiment, when the relay <NUM> is not operated and the movable contact <NUM> is in the neutral position as shown in <FIG>, a distance d1 between the front end <NUM> and the movable spring <NUM> or the conductive plate <NUM> in the contact/separation direction of the contacts is set to be smaller than a distance d2 between the fixed contact <NUM> and the movable contact <NUM>. Since d1 is smaller than d2, even if the movable contact part <NUM> vibrates due to resonance, the movable spring comes into contact with the post before the amplitude of the vibration becomes large, and thus the amplitude does not become larger any more. Therefore, it is possible to prevent the fixed contact <NUM> and the movable contact <NUM> from unintentionally contacting each other due to resonance. By virtue of the post <NUM> having the above-mentioned dimensional relationship, malfunction of the relay during the moving part resonates can be avoided.

In particular, in a DC relay to which a high voltage such as <NUM> to <NUM> V is applied, a member for extending or extinguishing an arc, specifically a permanent magnet or an arc extinguishing plate, is provided in order to protect the contacts. Since these members are attached to a component other than an arc-extinguishing chamber, etc., having an arc-extinguishing function, such members may increase costs and assembly man-hours of parts.

In the embodiment, as shown in <FIG> and <FIG>, the base <NUM> is formed into a frame shape or a box shape by resin molding, etc. The base <NUM> has a recess <NUM> into which the permanent magnet <NUM> is fitted, a slot <NUM> into which the arc extinguishing plate <NUM> is inserted, and an outer surface <NUM> to which the yoke <NUM> is attached. The base <NUM> shown in <FIG>, etc., is integrally formed.

<FIG> shows a state in which the permanent magnet <NUM> (<FIG>), the arc-extinguishing plate <NUM> and the yoke <NUM> are attached to the base <NUM>, and <FIG> shows a state in which the base <NUM> is removed from <FIG> for clarification. As shown in <FIG>, the yoke <NUM>, the permanent magnet <NUM> and the arc-extinguishing plate <NUM> can be attached to the base <NUM> to which the fixed contact <NUM> is attached. The base <NUM> also functions as an arc-extinguishing chamber having high arc-blocking property, including the permanent magnet <NUM> surrounding the fixed contact <NUM>, the yoke <NUM> and the arc-extinguishing plate <NUM>.

<FIG> is a side sectional view of the base <NUM>, showing how the arc is elongated and extinguished by the permanent magnet <NUM>, the arc-extinguishing plate <NUM> and the yoke <NUM>. The arc <NUM> generated between the fixed contact <NUM> and the movable contact <NUM> is elongated to the arc-extinguishing chamber within the base <NUM> by the magnetic flux from the permanent magnet <NUM> and the yoke <NUM>. It is preferable that the surfaces of the two permanent magnets <NUM> facing each other have the same poles, and such a homopolar facing arrangement can elongate the arcs generated between each contact in the same direction.

<FIG> shows a state of an arc in a comparative example in which the arc-extinguishing plate <NUM> is not provided. In <FIG>, the arc <NUM> is elongated by the arc-extinguishing plate <NUM> inserted into the base <NUM>. On the other hand, in <FIG> in which the arc-extinguishing plate <NUM> is not provided, the arc spreads in the base <NUM> without being elongated. In <FIG>, by attaching all of the members related to the arc-extinguishing function to the base <NUM> in which a space for extinguishing the arc is secured, the relay having a high arc-blocking property is provided without increasing the number of parts.

The embodiment is a so-called double-break type relay, and the fixed contact <NUM> is attached to the base <NUM>. Therefore, it is preferable to arrange the permanent magnet and/or the arc-extinguishing plate at a position close to each fixed contact. In the embodiment, the two permanent magnets <NUM> are attached to both sides of the base <NUM>, and the two arc-extinguishing plates <NUM> are positioned on the base <NUM> so as to extend to the immediate vicinity of the respective fixed contacts <NUM>. The yoke <NUM> is configured to be vertically divided into two parts and mounted from the vertical direction of the base <NUM> from the viewpoint of ease of assembly. However, the present disclosure is not limited as such, for example, the base may be horizontally divided into two parts, and mounted from the left-right direction of the base <NUM>.

<FIG> is an exploded perspective view of a fixed contact part <NUM>'. In the fixed contact portion <NUM>', a magnetic shield <NUM> made of a material having a high magnetic permeability, such as iron, is arranged between the two fixed contacts <NUM> on a pedestal <NUM> of the base <NUM>. With respect to the other components similar to those in <FIG>, the same reference numerals are added thereto, and the detailed explanation thereof will be omitted.

<FIG> shows a state in which the base is removed from <FIG> shows the permanent magnet <NUM>, the arc-extinguishing plate <NUM>, the yoke <NUM> and the magnetic shield <NUM>. In the embodiment, in addition to the arc-extinguishing function, the magnetic flux absorbing function described below can also be obtained.

<FIG> is a diagram for explaining the relationship between the current flowing through the fixed contact <NUM> and the magnetic flux when the magnetic shield is provided, and <FIG> shows the relationship between the current and the magnetic flux in a comparative example in which the magnetic shield <NUM> is not provided. When a DC relay is used, for example, the current, input to one of the fixed terminals <NUM> in the direction of an arrow <NUM>, passes through the fixed contact <NUM>, the movable contact <NUM>, the conductive plate <NUM> and the other fixed contact <NUM>, and then flows out from the other of the fixed terminals <NUM> in the direction of an arrow <NUM>. Due to the current flowing in this way, a magnetic flux <NUM> is generated between the two fixed contacts <NUM> and the two fixed terminals <NUM> in the direction perpendicular to the drawing sheet and from the back to the front. When a large current is applied to the closed contacts of the relay, an electromagnetic repulsive force is generated between the movable contact and the fixed contact, whereby the contacts may be separated or welded to each other.

As shown in <FIG>, when the magnetic shield <NUM> is not provided, the influence of the magnetic flux <NUM> extends to the range indicated by a broken line <NUM>, for example, so that the Lorentz force in the direction indicated by an arrow <NUM> acts on the conductive plate <NUM> within an area <NUM>. In <FIG>, a force in the contact opening direction is applied to the conductive plate <NUM>, whereby the fixed contact <NUM> and the movable contact <NUM> may be separated from each other by the Lorentz force.

On the other hand, when the magnetic shield <NUM> is provided as shown in <FIG>, the magnetic flux is absorbed by the magnetic shield <NUM>, so that it is possible to prevent the conductive plate <NUM> from generating a force in the opening direction of the contacts due to the influence of the magnetic flux. Therefore, according to the embodiment, a relay which is unlikely to malfunction even when a large current is passed is provided.

The magnetic shield <NUM> is positioned not on the movable part of the relay <NUM> but on the fixed part such as the base <NUM>. Although it is possible to locate the magnetic shield on the movable part, it is preferable to not locate the magnetic shield on the movable part, since malfunction tends to occur when an impact is applied to the relay having the relatively heavy movable part. In the embodiment, since the magnetic shield is positioned at the fixed part, the weight of the movable part is not increased by the magnetic shield, and such a defect can be prevented.

Claim 1:
A relay (<NUM>) comprising:
a case (<NUM>); and
a main body (<NUM>) comprising:
an electromagnet (<NUM>);
a yoke (<NUM>); and
a movable contact part (<NUM>) having an armature (<NUM>) configured to operate corresponding to an activation of the electromagnet, a movable spring (<NUM>) attached to the armature, and a movable contact (<NUM>) attached to the movable spring; and
a fixed contact part (<NUM>) having a base (<NUM>) to which a fixed contact (<NUM>) opposed to the movable contact is attached,
wherein the main body (<NUM>) is insertable and incorporable into the case (<NUM>) by moving the main body (<NUM>) relative to the case (<NUM>) along a contact/separation direction between the fixed contact (<NUM>) and the movable contact (<NUM>), and
wherein the fixed contact part (<NUM>) is insertable into the case (<NUM>) in the contact/separation direction, and
wherein the base (<NUM>) has a leg (<NUM>) extending in the contact/separation direction, an end surface of the leg is configured to contact the yoke (<NUM>), and the leg is positioned above the armature (<NUM>) and is spaced away from an upper part of the armature, so as to determine a positional relationship between the fixed contact part (<NUM>) and the electromagnet (<NUM>) in the contact/separation direction.