CN117716462A

CN117716462A - Thermal relay

Info

Publication number: CN117716462A
Application number: CN202280052965.8A
Authority: CN
Inventors: 小野木悠真; 鸭崎武雄; 三浦飒斗; 李守连
Original assignee: Fuji Electric FA Components and Systems Co Ltd
Current assignee: Fuji Electric FA Components and Systems Co Ltd
Priority date: 2022-02-04
Filing date: 2022-12-23
Publication date: 2024-03-15
Also published as: JPWO2023149129A1; WO2023149129A1; KR20240024987A

Abstract

A contact reversing mechanism for switching contacts of the present invention comprises a movable plate (23), wherein the movable plate (23) is arranged swingably on a reversing mechanism support part (20) with one end as a fulcrum and the other end side, and a movable contact (30 a) among contacts is provided on one surface. The reversing mechanism support section includes: v-shaped support grooves (36 a, 37 a) formed in a pair of first movable plate holding arms (36, 37) extending in parallel, for placing one end of the movable plate (23) as a fulcrum; and a second movable plate holding arm (38) extending from the first movable plate holding arm and supporting the movable plate in a state in which the movable plate is tilted by a fixed amount.

Description

Thermal relay

Technical Field

The present invention relates to a thermal relay that is connected to a circuit breaker for wiring, an electromagnetic contactor, or the like to protect a load (for example, a motor) from overcurrent.

Background

As a thermal relay that detects an overcurrent flowing through a main circuit and operates, for example, a device of patent document 1 is known.

The thermal relay of patent document 1 includes: a bimetal which bends and displaces when an overcurrent is detected; a release lever driven by the displacement of the displacement member linked with the bimetal; and a contact reversing mechanism for reversing the contact by rotation of the release lever. The contact reversing mechanism includes: a movable plate which is swingably arranged on the reverse mechanism supporting portion with one end serving as a fulcrum and the other end side; a movable contact provided on a contact on one surface of the movable plate; and a reversing spring which is arranged between the other end side of the movable plate which are positioned opposite to each other through the supporting point and a spring supporting part formed on the reversing mechanism supporting part.

Here, the reversing mechanism support portion of patent document 1 has a pair of movable plate holding arms extending parallel to each other, and engagement grooves are formed on the lower end sides of the pair of movable plate holding arms. One end of the movable plate is supported by the engagement grooves of the pair of movable plate holding arms as a fulcrum, and the other end of the movable plate abuts against the upper portions of the pair of movable plate holding arms, whereby the pair of movable plate holding arms support the movable plate in an inclined state.

Prior art literature

Patent literature

Patent document 1: japanese patent No. 5152102

Disclosure of Invention

Problems to be solved by the invention

However, in the thermal relay of patent document 1, it is difficult to form a pair of movable plate holding arms extending parallel to each other into the same shape, and there is a possibility that the amount of inclination of the movable plate varies. When the amount of inclination of the movable plate varies, the position of the movable contact provided on the movable plate may vary, and the opening and closing positions of the contacts may become unstable.

Accordingly, an object of the present invention is to provide a thermal relay capable of setting a position of a movable contact with high accuracy by suppressing a deviation in an inclination amount of a movable plate, and capable of finely adjusting the position of the movable contact, thereby stabilizing an opening and closing position of the contact.

Technical scheme for solving problems

To achieve the above object, a thermal relay according to an aspect of the present invention includes: a bimetal capable of bending displacement upon detection of an overcurrent; a release lever driven by the displacement of the displacement member linked with the bimetal; and a contact reversing mechanism for reversing the contact by the rotation of the release lever. The contact reversing mechanism includes: a movable plate which is swingably arranged on the reverse mechanism support portion with one end serving as a fulcrum and the other end side, and which has a movable contact among contacts provided on one surface; and a reversing spring which is arranged between the other end side of the movable plate which is positioned at the opposite sides of the movable plate through the supporting point and a spring supporting part formed on the reversing mechanism supporting part. The reversing mechanism support section includes: a pair of first movable plate holding arms having a V-shaped support groove formed thereon for placing one end of the movable plate as a fulcrum; and a second movable plate holding arm extending from one of the first movable plate holding arms to be abutted against the other end side of the movable plate, and supporting the movable plate in a state in which the movable plate is tilted by a certain amount of tilt.

Effects of the invention

According to the thermal relay of the present invention, since the movable plate is supported in a state of abutting against the second movable plate supporting portion of the reversing mechanism supporting portion, the deviation of the amount of inclination of the movable plate can be greatly suppressed, the position of the movable contact can be finely adjusted with high accuracy, and the opening and closing positions of the contacts can be stabilized.

Drawings

Fig. 1 is a perspective view showing the external appearance of a thermal relay according to the present invention.

Fig. 2 is a diagram showing an internal structure of the thermal relay according to the present invention.

Fig. 3 (a) is a diagram showing a steady state contact reversing mechanism and a state contact (a contact), and fig. 3 (b) is a diagram showing a trip state contact reversing mechanism and the like.

Fig. 4 is a perspective view showing a reversing mechanism support portion constituting the contact reversing mechanism.

Fig. 5 is a view showing a state in which the reversing mechanism support portion supports the movable plate inclined by a predetermined inclination amount.

Fig. 6 is a view showing a state in which the first hook engaging portion engages with the engaging recess portion of the movable plate, and the second hook engaging portion engages with the V-shaped engaging groove of the spring supporting portion, and the tension coil spring is attached.

Fig. 7 is a view showing a hook positioning wall formed continuously with the V-shaped engagement groove of the spring supporting portion.

Detailed Description

Next, an embodiment of the present invention will be described with reference to the drawings. In the description of the drawings below, the same or similar parts are denoted by the same or similar reference numerals. It should be noted, however, that the drawings are schematic, and the relationship of thickness to planar dimensions, the ratio of thicknesses of the respective layers, and the like are different from reality. Therefore, specific thicknesses and dimensions should be determined with reference to the following description. The drawings include, of course, portions having different dimensional relationships and ratios.

The following embodiments are examples of an apparatus and a method for embodying the technical idea of the present invention, and the technical idea of the present invention is not intended to specify the materials, shapes, structures, arrangements, and the like of constituent parts as follows. The technical idea of the present invention can be variously modified within a technical scope defined by a scope of claims described in a scope of claims.

Fig. 3 to 6 show the X-direction and the Y-direction which are orthogonal to each other, and the Z-direction which is orthogonal to a plane including the X-direction and the Y-direction, and the specific configuration of each component will be described.

Fig. 1 shows an external appearance of a thermal relay 1 according to an embodiment of the present invention. The insulating case of the thermal relay 1 is composed of a cover including an upper case 2a, a lower case 2b, and a side case 2c, and a switch cover 3 that can be opened and closed by a hinge portion 3a is disposed on the upper portion of the upper case 2a. The main terminals 4a to 4c and the auxiliary terminals 5a to 5d are arranged in the upper case 2a, and the bar terminals 6a to 6c protrude from the side case 2c to the outside.

Fig. 2 shows the interior of the thermal relay 1 with the cover formed by the lower case 2b and the side case 2c removed. The thermal relay 1 includes 3 sets of heat elements 8a to 8c corresponding to the 3 of the main circuit, a shift element 10 slidably disposed in the left-right direction of fig. 2, which is engaged with the bimetal 9 of the heat elements 8a to 8c, an adjustment mechanism 11 that is driven by the sliding of the shift element 10, and a contact reversing mechanism 12 that switches the open/close state of the contacts by the operation of the adjustment mechanism 11. The contact is provided with a normally open contact (a contact) 30 in which the movable contact 30a is disconnected from the fixed contact 30b when the adjustment mechanism 11 is not operated. Although not shown, a normally closed contact (b contact) that contacts the fixed contact and the movable contact when the adjustment mechanism 11 is not operated is disposed at a position on the rear side of the contact reversing mechanism 12. An a contact 30 is connected between the auxiliary terminals 5a and 5b, and a b contact is connected between the auxiliary terminals 5c and 5 d.

As shown in fig. 2, the adjustment mechanism 11 includes an adjustment link 14, a release lever 15 rotatably supported by the adjustment link 14, and an ambient temperature compensation bimetal 16 fixed to the release lever 15 and compensating for an ambient temperature engaged with the displacement member 10.

The adjustment link 14 is composed of a link support portion 17 that supports the release lever 15, and a leg portion 18 that extends downward from one side of the link support portion 17.

A support shaft 19 is provided to protrude into the upper case 2a on the inner wall of the lower portion side of the case, and the entire adjustment link 14 is rotatably supported by the upper case 2a around the support shaft 19 by inserting the tip end portion of the support shaft 19 into a bearing hole 18a formed in the leg portion 18.

The release lever 15 is formed with a rotation shaft 15a rotatably supported by a link support portion 17 of the adjustment link 14, a reverse spring pressing portion 15b is formed at a lower portion via the rotation shaft 15a, a cam contact portion 15c is formed at an upper portion, and a free end is fixed to one end of an ambient temperature compensation bimetal 16 located below.

As shown in fig. 3 (a), the contact reversing mechanism 12 includes a reversing mechanism support portion 20 supported in the upper case 2a, a linking plate 22 disposed in the vicinity of the reversing mechanism support portion 20 and rotatably supported by a support shaft 21 provided on the inner wall of the insulating case 2, a movable plate 23 supported by the reversing mechanism support portion 20 in a state of being inclined by a constant amount, a reversing spring 24 composed of a tension coil spring and arranged between the upper portion of the movable plate 23 and the lower portion of the reversing mechanism support portion 20, and a contact fixing portion 25.

As shown in fig. 4, the reversing mechanism support portion 20 is formed by punching a metal plate into a predetermined shape and bending the metal plate at a predetermined position. The reversing mechanism support portion 20 includes a support base 35 extending in the Z direction, the auxiliary terminal 5b described above provided extending in the Y direction from the support base 35, a pair of first movable plate holding arms 36, 37 bent from one end of the support base 35 in the Z direction and extending parallel to each other, a second movable plate holding arm 38 bent from an end of the first movable plate holding arm 36 in the Z direction separated from the support base 35, and a spring support portion 39 extending from the other end of the support base 35 in the Z direction in the X direction in which the first movable plate holding arms 36, 37 extend.

V-shaped grooves 36a, 37a are formed in the pair of first movable plate holding arms 36, 37, the lower surface of the movable plate 23 being in contact with portions of the plate thickness direction surfaces. These V-shaped grooves 36a and 37a are formed by press working in the same step, and the positions of the valleys in the X direction are identical to each other and extend straight in the Y direction. Further, a projection 40 that protrudes spherically in the X direction on the first movable plate holding arm 36 side is formed on the second movable plate holding arm 38 at a portion of the plate thickness direction surface. The protrusion 40 is formed by performing protrusion forming by a press machine.

Fig. 5 shows the movable plate 23 supported by the pair of first movable plate holding arms 36 and 37 and the second movable plate holding arm 38 in an inclined state (tilted state). A movable contact 30a of the a contact 30 is provided on the surface 23a of the movable plate 23. The position of the movable contact 30a in the X direction is determined by disposing the movable plate 23 in a state in which the lower portion 23c of the movable plate 23 is placed on the V-shaped grooves 36a, 37a of the first movable plate holding arms 36, 37 of the reversing mechanism supporting portion 20 and the rear surface 23b is abutted against the projection 40 formed on the second movable plate holding arm 38, and the movable plate 23 is supported in a state in which the movable plate is inclined by a fixed amount of inclination.

As shown in fig. 6, the movable plate 23 is notched at the upper side to form an engagement recess 41. Further, a V-shaped engagement groove 42 extending in the X direction is formed in the lower surface of the front end of the spring support portion 39. The reversing spring 24 is supported between the upper portion of the movable plate 23 and the spring supporting portion 39 of the reversing mechanism supporting portion 20 by the first hook engaging portion 24a engaging with the engaging recess 41 and the second hook engaging portion 24b engaging with the engaging groove 42.

Fig. 7 is an enlarged view of the spring support portion 39 of the reversing mechanism support portion 20, in which a hook positioning wall 43 extending downward (the other side in the Z direction) from the engagement groove 42 is formed at an end portion of the engagement groove 42 on the support base 35 side.

Returning to fig. 3 (a), the a-contact fixing portion 25 includes the auxiliary terminal 5a extending in one direction in the Y direction from the fixing base 26, and a leaf spring 27 fixed to the fixing base 26 and extending in one direction in the Z direction, and a fixed contact 30b of the a-contact 30 is provided on the free end side of the leaf spring 27. A first engagement pin 44a and a second engagement pin 44b are provided on the surface 22a side of the interlocking plate 22 so as to be engageable with the movable plate 23, and the first engagement pin 44a and the second engagement pin 44b rotate the interlocking plate 22 around the support shaft 21 in accordance with the reversing operation and the resetting operation of the movable plate 23.

Further, a movable contact and a fixed contact of a normally closed contact (b contact), not shown, are also arranged on the back surface side of the interlocking plate 22.

Next, the operation of the thermal relay 1 according to the present embodiment will be described.

As shown in fig. 2, when an overload current flows through the main circuit to heat the heaters of the heat elements 8a to 8c, the bimetal 9 is bent, and the displacement of the free end thereof displaces the displacement element 10 in the arrow direction of fig. 1. When the free end of the ambient temperature compensating bimetal 16 is pressed by the displacement element 10, the release lever 15 integrated with the temperature compensating bimetal 16 rotates clockwise about the rotation shaft 15a supported by the adjustment link 14, and the reversing spring pressing portion 15b of the release lever 15 presses the reversing spring 24.

When the release lever 15 rotates clockwise, the urging force of the reversing spring urging portion 15b exceeds the spring urging force of the reversing spring 24, and the movable plate 23 reverses with the lower portion as a fulcrum. In addition, at the time of the reversing operation of the movable plate 23, the interlocking plate 34 that transmits the reversing operation of the movable plate 23 via the first engagement pin 44a also rotates about the support shaft 21.

As a result, as shown in fig. 3 (b), the movable contact 30a and the fixed contact 30b of the a contact 30 are closed, and the fixed contact and the movable contact of the b contact, which are not shown but are in the closed state, are opened and are in the tripped state. Based on the information of the a contact 30 and the b contact in the tripped state, for example, an electromagnetic contactor (not shown) connected to the main circuit is turned on (off) to cut off the overcurrent.

Next, the effect of the thermal relay 1 according to the present embodiment will be described.

In the present embodiment, the movable plate 23 is supported in a state of abutting against the protrusion 40 formed on the second movable plate holding arm 38 of the reversing mechanism support portion 20, and the variation in the amount of inclination of the movable plate 23 can be significantly suppressed and the position of the movable contact 30a provided on the movable plate 23 can be set with high accuracy, as compared with a conventional device in which the movable plate abuts against a pair of movable plate holding arms which are difficult to form the same shape. This can stabilize the opening and closing positions of the a contacts 30.

Further, since the V-shaped grooves 36a and 37a engaged with the lower surface of the movable plate 23 as the fulcrum are formed by press working in the same step, the positions of the valleys of the V-shaped grooves 36a and 37a can be made uniform in the X direction and linearly extended in the Y direction, the position of the lower surface of the movable plate 23 in the X direction can be set with high accuracy.

Further, by forming the protrusion 40 against which the rear surface 23b of the movable plate 23 abuts by varying the protrusion amount by the boss forming performed by the press machine, the amount of inclination of the movable contact 30a in the X direction can be set with high accuracy, and fine adjustment of the position of the movable contact can be performed.

Further, since the engagement recess 41 is formed by forming a cutout in the upper side of the movable plate 23, the first hook-shaped engagement portion 24a of the reversing spring (tension coil spring) 24 can be easily engaged with the engagement recess 41 from above.

Further, the second hook-shaped engaging portion 24b of the reversing spring 24 is engaged with the engaging groove 42 of the spring supporting portion 39 of the reversing mechanism supporting portion 20, but the hook positioning wall 43 is formed continuously with the engaging groove 42, so that the second hook-shaped engaging portion 24b can be guided to the engaging groove 42 after abutting against the hook positioning wall 43. In this way, by making the first hook engaging portion 24a of the reversing spring 24 easily engage with the engaging recess 41 of the movable plate 23 from above, and making the second hook engaging portion 24b of the reversing spring 24 abut against the hook positioning wall 43 and then be guided to engage with the engaging groove 42, automatic assembly of the reversing spring 24 into the engaging recess 41 of the movable plate 23 and the engaging groove 42 of the spring supporting portion 39 can be achieved in a state where the first and second hook engaging portions 24a, 24b of the reversing spring 24 are mechanically gripped.

Description of the reference numerals

1 thermal relay

2a upper shell

2b lower shell

2c side shell

3 switch cover

4 a-4 c main terminal

5 a-5 d auxiliary terminals

End terminals of 6 a-6 c rod

8 a-8 c thermal element

9 bimetal

10 shift piece

11 adjustment mechanism

12-contact reversing mechanism

14 adjusting connecting rod

15 release lever

15a rotation shaft

15b reversing spring pressing part

15c cam contact portion

16 ambient temperature compensating bimetal

17 connecting rod supporting part

18 leg portions

18a bearing hole

19 support shaft

20 reversing mechanism support

21 support shaft

22 linkage plate

23 movable plate

24 reversing spring

24a first hook-shaped engaging portion

24b second hook-shaped engaging portion

25a contact fixing part

26 fixed base

27 leaf spring

30a contact

30a movable contact

30b fixed contact

35 support base

36. 37 first movable plate holding arm

36a, 37a V groove (V-shaped support groove)

38 second movable plate holding arm

39 spring support

40 projection (positioning projection)

41 engagement recess

42 clamping groove (V-shaped clamping groove)

43 hook positioning wall

44a first engagement pin

44b second engagement pins.

Claims

1. A thermal relay, comprising:

a bimetal capable of bending displacement upon detection of an overcurrent;

a release lever driven by the displacement of the displacement member linked with the bimetal; and

a contact reversing mechanism for reversing the contact by the rotation of the release lever,

the thermal relay is characterized in that:

the contact reversing mechanism includes:

a movable plate which is swingably arranged on the reverse mechanism support portion with one end serving as a fulcrum and the other end side, and which has a movable contact among contacts provided on one surface; and

a reversing spring which is arranged between the other end side of the movable plate which is positioned at the opposite sides of the supporting point and a spring supporting part formed on the reversing mechanism supporting part,

the reversing mechanism support portion includes:

a pair of first movable plate holding arms having a V-shaped support groove formed thereon for placing the one end of the movable plate as the fulcrum; and

and a second movable plate holding arm extending from one of the first movable plate holding arms to be abutted against the other end side of the movable plate, and supporting the movable plate in a state where the movable plate is tilted by a constant amount of tilt.

2. The thermal relay of claim 1, wherein the thermal relay comprises a plurality of relay contacts,

the support grooves formed in the pair of first movable plate holding arms are formed by press working.

3. A thermal relay according to claim 1 or 2, wherein,

the second movable plate holding arm is formed with a positioning projection against which the other surface of the movable plate abuts.

4. A thermal relay according to claim 3,

the positioning protrusion is formed by boss forming.

5. The thermal relay according to any one of claims 1 to 4, wherein,

the reversing spring is a tension coil spring provided with a first hook-shaped clamping part and a second hook-shaped clamping part at two ends,

an engagement recess is formed by forming a cutout in a side portion on the other end side of the movable plate, a V-shaped engagement groove is formed in the spring support portion formed in the reversing mechanism support portion,

the first hook engaging portion engages with the engaging recess of the movable plate, and the second hook engaging portion engages with the engaging groove of the spring supporting portion to apply a tensile force to the movable plate.

6. The thermal relay of claim 5, wherein the thermal relay comprises a plurality of relay contacts,

the spring support portion is formed with a hook positioning wall formed continuously with the engagement groove, and the hook positioning wall abuts against the second hook engagement portion at the time of mounting to guide the second hook engagement portion to the engagement groove.