High-frequency relay

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a high-frequency relay suitable for switching a high-frequency signal.

2. Description of the Related Art

In the related art, there is disclosed a high-frequency relay in Japanese Patent Laid-Open No. 2001-345036. In this high-frequency relay, an electromagnetic block is excited and demagnetized to rotate a movable iron piece. A movable block is pushed down by a push-in spring interlocking with a rotation of the movable iron piece so as to close a contact. The movable block is pushed up by a return spring so as to open the contact. The movable block has a movable contact piece, and a support portion formed in the central portion of the movable contact piece. The support portion moves up and down through an opening portion formed in a ground plate so as to connect/disconnect the opposite end portions of the movable contact piece with/from fixed contacts under the ground plate. Thus, a transmission line is switched on/off.

However, in the related-art high-frequency relay, the return spring made from a metal material is provided integrally with the upper portion of the ground plate because the return spring affects the high-frequency characteristic about the isolation of the transmission line. Accordingly, a useless space is formed under the ground plate so that the height of the high-frequency relay increases. In addition, there is a problem that the structure of the high-frequency relay becomes complicated and the workability thereof deteriorates so that the cost increases.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide a high-frequency relay which is small in size, simple in structure and easy to work and which can be manufactured at a low price.

As means for solving the foregoing problem, the invention provides a high-frequency relay comprising:

a base block having fixed terminals insert-molded to expose fixed contacts;

an electromagnetic block having a coil wound around an iron core through a spool, and mounted on the base block; and

a movable block having movable contacts driven in accordance with excitation and demagnetization of the electromagnetic block so as to be connected with and disconnected from the fixed contacts of the base block, the movable block having a movable iron piece whose opposite end portions are to be connected with and disconnected from the fixed contacts of the fixed terminals respectively; and

a return spring for elastically supporting the movable block, the return spring being disposed to be biased to one of the fixed terminals on the base block.

With this configuration, an enough distance between the return spring and one of the fixed terminals can be secured so that desired insulation performance can be secured. In addition, the return spring can be disposed in a surplus space on the upper surface of the base block so that the height of the high-frequency relay can be suppressed.

In order to enhance the insulation performance, it is preferable that: each of the fixed terminals includes a fixed contact portion in which the fixed contact is formed, and a foot portion provided to extend from the fixed contact portion, and the base block includes a recess portion enclosed by a protruding strip portion formed in an upper surface of the base block, and a seat portion being provided in the recess portion so that the fixed contact portion can be disposed on the seat portion while a surface and side edges of the fixed contact portion are exposed.

It is preferable that the high-frequency relay further comprises a movable iron piece which rotates due to excitation and demagnetization of the electromagnetic block, the movable iron piece having s push-in spring for pushing the movable block in accordance with a rotation of the movable iron piece, wherein the movable block is connected with and disconnected from the base block due to the push-in spring, so that force acting on the movable block from the push-in spring and force acting on the movable block from the return spring cancel each other as to components other than components in a direction in which the movable block is connected with and disconnected from the base block. In this case, the moving direction of each movable block can be stabilized.

It is preferable that the return spring includes a rectangular frame portion and an elastic tongue piece extending from an inner edge of the rectangular frame portion, and the movable block is supported by a forward end portion of the elastic tongue piece so that the elastic tongue piece and the rectangular frame portion can be deformed elastically. In this case, the elastic force per displacement can be set to be weak.

It is preferable that a displacement prevention function is formed in at least one of the return spring and the movable block.

In this case, the movement of each movable block can be stabilized.

It is preferable that the return spring includes a lock portion in the rectangular frame portion, and the base block includes a lock guard portion in which the lock portion is locked. In this case, the displacement of the return spring when the return spring is elastically deformed can be prevented surely in spite of a simple structure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1

is an exploded perspective view of a high-frequency relay according to an embodiment of the invention;

FIG. 2A

is a perspective view of a base block shown in

FIG. 1

;

FIG. 2B

is a plan view of the base block shown in

FIG. 1

;

FIG. 3A

is a sectional view of the base block shown in

FIGS. 2A and 2B

;

FIG. 3B

is a partially enlarged view of

FIG. 3A

;

FIG. 3C

is a perspective view of

FIG. 3A

from the bottom surface side;

FIG. 4

is a perspective view of a return spring shown in

FIG. 1

;

FIG. 5

is a perspective view of a ground plate shown in

FIG. 1

;

FIG. 6A

is a perspective view of a movable block shown in

FIG. 1

;

FIG. 6B

is a perspective view of

FIG. 6A

from the bottom surface side;

FIG. 6C

is a sectional view of

FIG. 6A

;

FIG. 7A

is a perspective view of an electromagnetic block shown in

FIG. 1

;

FIG. 7B

is a front view of

FIG. 7A

;

FIG. 8A

is a perspective view from the bottom surface side, showing the electromagnetic block shown in

FIG. 1

;

FIG. 8B

is a perspective view from the bottom surface side, showing a movable iron piece and a push-in spring according to another embodiment of the invention;

FIG. 8C

is a perspective view from the bottom surface side, showing a movable iron piece and a push-in spring according to the embodiment of the invention;

FIG. 8D

is a perspective view from the bottom surface side, showing an electromagnetic block in which the movable iron piece and the push-in spring shown in

FIG. 8B

have been installed;

FIG. 8E

is a perspective view from the bottom surface side, showing an electromagnetic block in which the movable iron piece and the push-in spring shown in

FIG. 8C

have been installed;

FIG. 9A

is an exploded perspective view of the movable iron piece and the push-in spring;

FIG. 9B

is a perspective view from the bottom surface side, showing the state where the movable iron piece and the push-in spring have been installed;

FIG. 10A

is a perspective view showing the state where the movable blocks and the ground plate have been mounted on the base block;

FIG. 10B

is a sectional view of

FIG. 10A

;

FIG. 11

is a sectional view of the high-frequency relay according to this embodiment; and

FIG. 12

is a perspective view showing the state where a casing has not yet been installed in the high-frequency relay according to the embodiment.

DETAILED DESCRIPTION OF THE INVENTION

An embodiment of the invention will be described below with reference to the accompanying drawings.

FIG. 1

shows a high-frequency relay according to this embodiment. The high-frequency relay is mainly arranged as follows. That is, a ground plate

2

, movable blocks

3

and an electromagnetic block

4

are mounted on a base block

1

, and covered with a casing

5

.

The base block

1

has a substantially rectangular plate-like shape as shown in

FIGS. 2A-2B

and

FIGS. 3A-3C

, which is obtained by insert-molding of fixed terminals

6

a,

6

b

and

6

c.

Each of the fixed terminals

6

a,

6

b

and

6

c

is obtained by bending a conductive plate-like piece substantially at a right angle, and constituted by a fixed contact portion

7

and a foot portion

8

. Two fixed contacts

7

c

are provided in the fixed contact portion

7

of the fixed terminal

6

c

(common terminal) disposed in the central portion of the base block

1

. One fixed contact

7

a,

7

b

is provided in the fixed contact portion

7

of the fixed terminal

6

a,

6

b

(terminal a, b) disposed on either end portion of the base block

1

.

Guide walls

9

are provided erectly on the top surfaces of the opposite end portions of the base block

1

. In each of the guide walls

9

(end surface side), a substantially U-shaped retention portion

10

is formed so that an iron core

39

which will be described later can be fixed thereto by caulking narrow portions

11

on the top of the retention portion

10

. Engagement recess portions

12

are formed on the opposite sides of the retention portion

10

. Each engagement recess portion

12

has a retention recess portion

13

in its central portion. In addition, the inner and outer surfaces of each guide wall

9

(side surface side) are formed stepwise.

Recess portions

15

each surrounded by a protruding strip portion

14

are formed in the upper surface of the base block

1

. The ground plate

2

is mounted on the protruding strip portion

14

. The height of the protruding strip portion

14

is limited in a plurality of places so that air layers

16

(see

FIG. 3B

) can be formed between the protruding strip portion

14

and the ground plate

2

to be mounted thereon. In addition, projections

17

are formed at four places in the protruding strip portion

14

so as to serve to fix the ground plate

2

. In addition, a seal groove

18

is formed in the protruding strip portion

14

so as to prevent seal agent from invading the inside at the time of sealing work which will be described later. In addition, bridging portions

19

are formed in the protruding strip portion

14

so as to prevent the thin fixed terminals

6

a,

6

b

and

6

c

(the plate thickness used here is about 0.18 mm) from being deformed when the contacts are switched on/off. Each of the bridging portions

19

is made as narrow as possible but wide enough to allow resin to flow at the time of insert-molding. Thus, the bridging portions

19

are designed so that the fixed terminals

6

a,

6

b

and

6

c

are prevented from floating when the contacts are switched on/off while the exposed area of each fixed terminal

6

a,

6

b,

6

c

is made maximal. The opposite end portions and the central portion of the recess portions is project upward so as to form seat portions

20

. The fixed contact portions

7

of the fixed terminals

6

are exposed over the seat portions

20

respectively. In each seat portion

20

, not only the top surface of the fixed contact portion

7

but also its edge portion

7

d

are exposed. In addition, lock guard portions

21

for positioning a return spring

100

are formed in each recess portion

15

.

In each return spring

100

, an elastic tongue portion

23

is formed in a rectangular frame portion

22

by press working out of a plate-like spring material as shown in FIG.

4

. Lock portions

24

are provided to extend from the opposite sides at one end of the rectangular frame portion

22

. The base portion of the elastic tongue portion

23

is supported on the rectangular frame portion

22

through a bent portion

25

, while the elastic tongue portion

23

is made easy to deform elastically due to the function of a depressed portion

26

formed in the rectangular frame portion

22

. In addition, a displacement prevention stopper portion

27

is formed in the forward end of the elastic tongue piece

23

. Each return spring

100

is disposed in the recess portion

15

of the base block

1

with the lock portions

24

being locked in the lock guard portions

21

of the base block

1

. Thus, when the forward end of the elastic tongue piece

23

is pressed, the return spring

100

is elastically deformed not only in the elastic tongue piece

23

but also over a wide range from the base portion of the elastic tongue piece

23

to the lock portions

24

of the rectangular frame portion

22

. Accordingly, a desired weak elastic force can be obtained in accordance with a predetermined displacement of the return spring

100

even in a narrow space limited within the recess portion

15

of the base block

1

.

A part of each guide wall

9

extends to each side surface of the base block

1

as described above. At one side edge, the guide wall

9

sinks in all the area but the central portion and the opposite end portions thereof. At the other side edge, the guide wall

9

sinks at four places between the central portion and the opposite end portions. Then, a shield piece

33

of the ground plate

2

which will be described later is disposed in each sinking position.

In the bottom surface of the base block

1

, as shown in

FIG. 3C

, the central portion and the outer edge portion thereof is cut off to reach a predetermined depth, and through holes

1

a,

1

b

and

1

c

are formed to penetrate the centers of the seat portions

20

where the fixed contact portions

7

of the fixed terminals

6

should be placed, respectively. Thus, the fixed terminals

6

can be supported directly by a mold at the time of insert-molding, so that the fixed terminals

6

can be prevented from being displaced. Incidentally, a recess portion

1

d

is provided for a gate used for injection-molding of the base block

1

so that the mark of the gate is prevented from projecting over the bottom surface.

As shown in

FIG. 5

, the ground plate

2

is obtained by pressing working out of a conductive plate-like product and rectangular holes

28

are formed respectively on the opposite sides of the ground plate

2

. Contact portions

29

are formed on the opposite sides of each rectangular hole

28

so as to project from the lower surface of the ground plate

2

, respectively. Reinforcing ribs

30

are formed on the opposite side portions of the ground plate

2

so as to bulge upward respectively. Mounting holes

31

are formed near the opposite ends of each reinforcing rib

30

. In addition, foot portions

32

are provided to extend from four places at one side edge of the ground plate

2

and from two places at the other side edge of the ground plate

2

. A wide shield piece

33

is formed in the base portion of each foot portion

32

.

In each movable block

3

, as shown in

FIGS. 6A-6C

, a support portion

35

made of synthetic resin is integrated with a central portion of a movable contact piece

34

made of a conductive plate material. An escape groove

36

is formed in the central portion of the upper surface of the support portion

35

in the direction in which the movable contact piece

34

extends. A protruding strip

37

is formed in the central portion on each of opposite sides of the escape groove

36

. The escape groove

36

is provided to prevent the mark of a not-shown gate from projecting over the upper surface of the support portion

35

. A pair of protrusion portions

38

are formed in the lower surface of the support portion

35

so that the displacement prevention stopper portion

27

of the return spring

100

is locked. The movable block

3

moves up and down with the support portion

35

being disposed in the rectangular hole

28

of the ground plate

2

. The opposite end portions of the movable contact piece

34

are brought into contact with the contact portions

29

of the ground plate

2

in the upper motion position where the movable block

3

is urged by the return spring

100

. On the other hand, the opposite end portions of the movable contact piece

34

are closed on the fixed contacts

7

a

and

7

c

or

7

b

and

7

c

in the lower motion position.

In the electromagnetic block

4

, as shown in

FIGS. 7A and 7B

, a coil

41

is wound around an iron core

39

through a spool

40

. The iron core

39

is made from a magnetic plate material bent. The opposite end portions of the iron core

39

are positioned in the retention portions

10

of the base block

1

, and the narrow portions

11

of the retention portions

10

are thermally caulked. Thus, the electromagnetic block

4

is fixed to the base block

1

. The spool

40

is constituted by a chassis portion

42

(see

FIG. 11

) covering the intermediate portion of the iron core

39

, and guide portions

43

a,

43

b

and

43

c

formed in the opposite ends and the center of the chassis portion

42

respectively. Each of the guide portions

43

a

and

43

b

in the opposite ends is constituted by a collar portion

44

and a thick portion

45

provided to extend from the collar portion

44

. A groove portion

44

a

is formed in the collar portion

44

so as to serve to guide the coil

41

when the coil

41

is wound by an automatic winding machine. A recess portion

45

a

is formed along the collar portion

44

in the thick portion

45

, and an insulating wall

46

is formed in the vicinity of the recess portion

45

a.

A coil terminal

47

is pressed into the thick portion

45

. The recess portion

45

a

serves to reduce the usage of resin and prevent the resin from being deformed after molding, and to chuck the coil

41

when the coil

41

is wound around the chassis portion

42

. The insulating wall

46

insulates adjacent coil terminals

47

from each other (although one coil terminal

47

is pressed into each thick portion

45

in this embodiment, two coil terminals may be pressed into the thick portion

45

in another form, and on such an occasion, insulation of those coil terminals

47

from each other can be secured by the insulating wall

46

). An escape portion

48

is formed in the end surface of each thick portion

45

so as to secure a space where resin can extend when the narrow portions

11

of the base block

1

are thermally caulked. In addition, one end portion of the iron core

39

is exposed between the opposite inner surfaces of each thick portion

45

, and slopes

45

b

are formed in the upper portions of the opposite inner surfaces of the thick portion

45

so as to be estranged from each other gradually as they go upward. The slopes

45

b

are provided to increase the strength of a molding mold. Further, engagement protrusion portions

49

for engaging with the engagement recess portions

12

of the base block

1

are formed in the lower surfaces of the thick portions

45

respectively. Guide grooves

50

(0.3 mm wide here) extend vertically in the opposite side surfaces of the central guide portion

43

c.

An escape recess portion

51

is formed on the upper side of each guide groove

50

, while an adjusting recess portion

52

is formed on the lower side of each guide groove

50

. The recess portions

51

and

52

are provided for making it possible to work a mold for molding the narrow guide grooves

50

. Particularly, the adjusting recess portion

52

also has a function for elastically deforming and adjusting a foot portion

60

of a push-in spring

57

which will be described later. In addition, guide protrusion portions

53

for laying the coil

41

between the pieces of the chassis portion

42

separated by the central guide portion

43

c

are formed at four places in the upper surface of the central guide portion

43

c.

Further, a recess portion

43

d

(see

FIG. 11

) is formed in the lower surface of the central guide portion

43

c,

and a permanent magnet

101

is disposed in the recess portion

43

d.

The permanent magnet

101

has different polarities in its upper and lower surfaces, and the upper surface thereof is in contact with the iron core

39

. The coil

41

is wound on the coil terminal

47

whose one end portion is pressed into the guide portion

43

a.

The coil

41

is inserted into the groove portions

44

a

formed in the collar portions

44

so as to be oriented. After the coil

41

is wound around the chassis portion

42

, the coil

41

is wound around the coil terminal

47

pressed into the guide portion

43

b.

A movable iron piece

54

is disposed rotatably under the electromagnetic block

4

. As shown in

FIG. 9A

, the movable iron piece

54

is made from a magnetic plate material, and a protruding strip

55

is formed in the central portion of the movable iron piece

54

so as to extend widthwise. The protruding strip

55

is attracted to the lower surface of the permanent magnet

101

so as to allow the movable iron piece

54

to rotate around the protruding strip

55

. In addition, a magnetic shield plate

56

made from a non-magnetic material such as stainless steel is pasted onto the upper surface on one end side of the movable iron piece

54

. Thus, the movable iron piece

54

is off magnetic balance between its opposite end portions as the movable iron piece

54

is rotatably supported on the permanent magnet

101

of the electromagnetic block

4

. Thus, the one end side (opposite to the magnetic shield plate

56

) of the movable iron piece

54

is attracted to the iron core

39

.

The push-in spring

57

is fixed to the central portion of the lower surface of the movable iron piece

54

. As shown in

FIG. 9B

, the push-in spring

57

is obtained by press working out of a magnetic plate material. The push-in spring

57

is constituted by a fixed portion

58

fixed to the movable iron piece

54

, a drive portion

59

for driving the movable block

3

, and foot portions

60

supported in the guide grooves

50

of the electromagnetic block

4

. The fixed portion

58

has a rectangular shape to be fixed to the lower surface of the central portion of the movable iron piece

54

by spot welding or the like. The drive portion

59

has a frame-like shape extending from the central portion on each of opposite sides of the fixed portion

58

, formed around the fixed portion

58

and bent downward stepwise. Adjustment portions

61

partially protruding from the movable iron piece

54

are formed on the opposite side portions of the drive portion

59

. A pressure portion

62

for pressing the protruding strip

37

formed in the support portion

35

of the movable block

3

is provided in the central portion at the forward end of each adjustment portion

61

. Each of the foot portions

60

is bent upward from the central portion on either side of the drive portion

59

, so as to be located in the middle between the pressure portions

62

. An arcuate bent portion

63

is formed at the tip of each foot portion

60

. In addition, the foot portions

60

are guided by the guide grooves

50

formed in the central guide portion

43

c

of the electromagnetic block

4

.

Incidentally, the push-in spring

57

to be fixed to the movable iron piece

54

may be of a type having no foot portion

60

, as shown in FIG.

8

B. Even such a push-in spring

57

having no foot portion

60

can be also supported easily (see

FIG. 8D

) if a support recess portion

102

is formed as shown in

FIG. 8A

in the adjusting recess portion

52

in the electromagnetic block

4

having the aforementioned configuration.

As shown in

FIG. 1

, the casing

5

has a box-like shape whose lower surface is open, and a recess portion

64

for preventing the mark of the gate from projecting is formed in the central portion of the upper surface of the casing

5

. A vent hole

65

is formed in a corner portion of the upper surface of the casing

5

. In addition, in the edge portion of the opening in the lower surface of the casing

5

, standoffs

66

are provided in the central portions of the opposite ends so as to form a predetermined gap between the bottom surface of the base block

1

and a not-shown printed board when the high-frequency relay is mounted on the printed board after the high-frequency relay has been assembled.

Next, description will be made on the method for assembling the high-frequency relay.

The return springs

100

are disposed in the recess portions

15

of the base block

1

in which the fixed terminals

6

have been insert-molded. Each return spring

100

is disposed to be biased to one side with respect to the fixed contacts

7

a

and

7

c

or

7

b

and

7

c

located in the opposite ends of the return spring

100

in the state where the lock portions

24

are locked in the lock guard portions

21

. That is, an enough distance from the fixed contact portion

7

in the central portion is secured to guarantee the insulation performance.

Next, the movable blocks

3

and the ground plate

2

are mounted on the base block

1

sequentially. The projections

17

of the base block

1

inserted into the mounting holes

31

of the ground plate

2

are thermally caulked so that the ground plate

2

is fixed to the base block

1

. In this state, as shown in

FIGS. 10A and 10B

, the displacement prevention stopper portion

27

formed in the elastic tongue piece

23

of each return spring

100

is engaged with the protrusion portions

38

of the support portion

35

while the side surfaces of the support portion

35

are guided by the rectangular holes

28

of the ground plate

2

. Thus, each movable block

3

is urged upward in the state where the movable block

3

can be pushed in. As a result, the opposite end portions (movable contacts) of the movable contact piece

34

abut against the contact portions

29

of the ground plate

2

.

On the other hand, the coil

41

is wound around the iron core

39

through the spool

40

, and the permanent magnet

101

is disposed in the recess portion

43

d.

Thus, the electromagnetic block

4

is formed. Then, the push-in spring

57

is integrated with the central portion of the lower surface of the movable iron piece

54

and the foot portions

60

of the push-in spring

57

are inserted into the guide grooves

50

of the electromagnetic block

4

while the protruding strip

55

of the movable iron piece

54

is attracted to the lower surface of the permanent magnet

101

. Thus, the movable iron piece

54

is disposed rotatably under the electromagnetic block

4

. In this state, the movable iron piece

54

is off magnetic balance due to the magnetic shield plate

56

pasted to one end portion of the movable iron piece

54

. Accordingly, the movable iron piece

54

rotates clockwise in

FIG. 11

in accordance with the attraction of the permanent magnet

101

.

Next, the electromagnetic block

4

provided with the movable iron piece

54

and the push-in spring

57

is mounted on the base block

1

mounted with the return springs

100

, the movable blocks

3

and the ground plate

2

. The engagement protrusion portions

49

formed in the guide portions

43

a

and

43

b

of the electromagnetic block

4

respectively are engaged with the engagement recess portions

12

of the base block

1

respectively, and the narrow portions

11

are thermally caulked to retain the iron core

39

. Thus, the electromagnetic block

4

is integrated with the base block

1

. As a result, the switching between the opposite end portions (movable contacts) of the movable contact piece

34

and the fixed contacts

7

a

and

7

c

or

7

b

and

7

c

of the fixed terminals

6

is located within the recess portion

15

surrounded by the ground plate

2

. The shield pieces

33

extending downward are formed at the side edges of the ground plate

2

. In addition, the air layer

16

is formed partially between the ground plate

2

and the protruding strip portion

14

forming the recess portions

15

. Accordingly, the insulation performance in the contact on/off portion is so high that a high-frequency signal can be transmitted suitably. In addition, the sides of the area where the movable block

3

is pressed by the push-in spring

57

due to rotation of the movable iron piece

54

are opened.

In this state, a current is once applied to the coil

41

through the coil terminals

47

so as to excite and demagnetize the electromagnetic block

4

. Then, the condition of a signal conducted between the fixed terminals

6

a

and

6

c

or

6

b

and

6

c,

that is, the operating characteristic such as the on-off timing of the contacts or the contact pressure is examined. Thus, it can be judged whether the movable iron piece

54

rotates suitably or not. When the operating condition is not suitable, the push-in spring

57

is deformed for adjustment. Here, first, the adjustment portion

61

protruding widthwise relatively to the movable iron piece

54

is grasped directly from its sides, and deformed. When a desired operating condition cannot be obtained by the adjusting work using the adjustment portion

61

, another adjusting work is performed by grasping and deforming the foot portions

60

through the adjusting recess portions

52

formed in the side surfaces of the electromagnetic block

4

to thereby change an angle of the foot portion

60

with respect to the movable block

34

. Thus, desired operating properties can be obtained surely.

When the adjusting work is completed thus, the base block

1

is covered with the casing

5

, and the mating face in the bottom surface of the casing

5

is sealed. In the sealing work, seal agent may invade the inside. However, since the seal groove

18

is formed in the base block

1

, there is no fear that the seal agent reaches the drive parts of the movable blocks

3

, the fixed contact portions

7

, or the like.

Next, description will be made on the operation of the high-frequency relay.

The high-frequency relay formed as described above is in use mounted on a printed board (not-shown) having a ground pattern formed therein. As a result, the contact on-off mechanism can be placed within an area enclosed by the ground plate

2

and the ground pattern of the printed board. Thus, the insulation performance can be enhanced further.

The movable iron piece

54

is off magnetic balance due to the magnetic shield plate

56

before a voltage is applied between the coil terminals

47

. Thus, the movable iron piece

54

rotates clockwise around the protruding strip

55

in

FIG. 11

in accordance with the magnetic force of the permanent magnet

101

. Accordingly, one of the movable blocks

3

is pushed down by the pressure portion

62

of the push-in spring

57

so that the opposite end portions (movable contacts) of its movable contact piece

34

are closed on the fixed contacts

7

a

and

7

c

respectively. Thus, continuity is secured between the fixed terminals

6

a

and

6

c.

The other movable block

3

is pushed up by the return spring

100

so that the opposite end portions (movable contacts) of its movable contact piece

34

are brought into contact with the contact portions

29

of the ground plate

2

(initial position).

Here, when a voltage is applied between the coil terminals

47

so as to excite the electromagnetic block

4

, the movable iron piece

54

is attracted thereto in its end portion distant from the iron core

39

. Thus, the movable iron piece

54

rotates counterclockwise around the protruding strip

55

in FIG.

11

. When the movable iron piece

54

is rotating, the movable iron piece

54

receives only a weak elastic force caused by elastic deformation in the foot portions

60

of the push-in spring

57

fixed to the lower surface of the movable iron piece

54

, particularly in a wide range reaching the bent portions

63

at the tips of the foot portions

60

in contact with the side surfaces forming the guide grooves

50

. Thus, the movable iron piece

54

rotates smoothly. With this rotation, the push-in spring

57

pushes down the movable block

3

against the urging force of the return spring

100

. The push-in spring

57

and the return spring

100

are disposed in substantially symmetrical positions with respect to the contact on-off position so as to cancel components other than vertical components, that is, horizontal components. Thus, most of force acting on the movable block

3

works only vertically. In addition, the return spring

100

elastically deforms not only the elastic tongue piece

23

but also a part of the rectangular frame. Therefore, the return spring

100

is displaced even by push-in force not so strong. Thus, the movable block

3

moves down smoothly so as to close the opposite end portions (movable contacts) of the movable contact piece

34

with the fixed contacts

7

b

and

7

c

respectively, and thereby make continuity between the fixed terminals

6

b

and

6

c.

Not only is the upper surface of each fixed contact portion

7

exposed, but the edge portion thereof is also exposed due to the existence of the seat portion

20

. Thus, the contact area with the air increases. As a result, the insulation performance is so high that it is difficult to leak any signal.

On the other hand, the movable block

3

released from the push-in force by the rotation of the movable iron piece

54

moves up due to the elastic force of the return spring

100

so as to separate the opposite end portions (movable contacts) of the movable contact piece from the fixed contacts

7

a

and

7

c

respectively, and thereby break the continuity between the fixed terminals

6

a

and

6

c.

Then, the opposite end portions of the movable contact piece

34

of the movable block

3

moving up are brought into contact with the contact portions

29

of the ground plate

2

so as to be grounded. Thus, any high-frequency signal is surely prevented from leaking.

When the voltage applied between the coil terminals

47

is eliminated, the movable iron piece

54

rotates clockwise in

FIG. 11

in accordance with the elastic force of the push-in spring

57

, the elastic force of the return spring

100

, the magnetic force of the permanent magnet

101

weakened on only one end side of the movable iron piece

54

due to the magnetic shield plate

56

, and the like. Thus, the movable iron piece

54

returns to the initial position.

Incidentally, description in this embodiment has been made on a so-called self-reset type relay in which the magnetic shield plate

56

is provided in the movable iron piece

54

so as to change over the contact on-off position between the case where a current is applied to the coil

41

and the case where no current is applied thereto. However, the invention may be configured as follows. That is, the invention may be applied to a so-called self-holding type relay in which the magnetic shield plate

56

is not provided, but the direction in which a current is applied to the coil

41

is changed to thereby change the polarities in the end portions of the iron core

39

so as to change over the contact on-off position. Alternatively, coil terminals

47

may be provided at three places. In this case, one of the coil terminals

47

is used as a common coil terminal, and two coils different in winding direction are provided. The winding direction of a coil connecting the common coil terminal with one of the rest two coil terminals is made different from the winding direction of a coil connecting the common coil terminal with the other. Thus, a current is applied between the common coil terminal and a selected one of the coil terminals so that the movable iron piece

54

can rotate.

As is apparent from the above description, according to the invention, each of return springs for elastically supporting movable blocks is disposed to be biased to one of fixed terminals. Thus, the distance between the return spring and one fixed terminal can be secured so that desired insulation performance can be secured in spite of a simple and low-price configuration. In addition, the return springs can be disposed in a surplus space on the upper surface of a base block so that the height of the high-frequency relay can be suppressed and the high-frequency relay can be miniaturized.

High-frequency relay

Information

Patent Number

Date Filed

Date Issued

Inventors

Original Assignees

Examiners

Agents

CPC

US Classifications

International Classifications

Abstract

Description

Claims

Priority Claims (1)

Foreign Referenced Citations (1)

Non-Patent Literature Citations (1)