CN116805563A

CN116805563A - Electronic overload relay

Info

Publication number: CN116805563A
Application number: CN202310174065.7A
Authority: CN
Inventors: 高桥志织; 石桥广脩; 小野木悠真; 东风彬生
Original assignee: Fuji Electric Co Ltd; Fuji Electric FA Components and Systems Co Ltd
Current assignee: Fuji Electric Co Ltd; Fuji Electric FA Components and Systems Co Ltd
Priority date: 2022-03-23
Filing date: 2023-02-23
Publication date: 2023-09-26
Also published as: JP2023141132A; TW202338883A; KR20230138401A

Abstract

The invention provides an electronic overload relay, which can realize low cost and miniaturization by setting the number of components used for switching a contact mechanism to be small. The electronic overload relay comprises a contact mechanism capable of switching between a stable state and a tripping state; an electromagnet having a movable shaft that moves in an axial direction when energized; a slider that moves in the axial direction in conjunction with the movable shaft when the current is supplied; and a driven member that alternately switches a stop position of the slider after the movement in the axial direction to a first stop position corresponding to the steady state and a second stop position corresponding to the trip state each time the electromagnet is energized.

Description

Electronic overload relay

Technical Field

The present invention relates to an electronic overload relay.

Background

Patent document 1 discloses an electronic overload relay configured to switch a contact mechanism between a trip position and a reset position using a permanent magnet and a coil that generate magnetic flux.

< prior art document >

< patent document >

Patent document 1 Japanese patent No. 4738530

Disclosure of Invention

< problem to be solved by the invention >

However, since the conventional electronic overload relay adopts a configuration in which one electromagnet, one permanent magnet, and four transistors are used for 2-direction control, or a configuration in which two electromagnets, one permanent magnet, and two transistors are used for 1-direction control, it is difficult to reduce the number of components used, and to reduce the cost and size.

< method for solving the problems >

An electronic overload relay of one embodiment includes a contact mechanism capable of switching to a steady state and a tripped state; an electromagnet having a movable shaft that moves in an axial direction when energized; a slider that moves in the axial direction in conjunction with the movable shaft when the current is supplied; and a driven member that alternately switches a stop position of the slider after the movement in the axial direction to a first stop position corresponding to the steady state and a second stop position corresponding to the trip state each time the electromagnet is energized.

< Effect of the invention >

According to the electronic overload relay of one embodiment, the number of components used for switching the contact mechanism can be set to be small, and therefore, cost reduction and downsizing can be achieved.

Drawings

Fig. 1 is an external perspective view of an electronic overload relay according to one embodiment.

Fig. 2 is an external perspective view of the electronic overload relay according to one embodiment, viewed from the bottom surface side.

Fig. 3 is an exploded perspective view of an electronic overload relay according to one embodiment, as seen from the bottom surface side.

Fig. 4 is a diagram showing a configuration of a contact switching mechanism included in the electronic overload relay according to one embodiment.

Fig. 5 is an external perspective view of a slider included in the contact switching mechanism according to the embodiment.

Fig. 6 is a diagram showing a structure of a heart cam mechanism included in the contact switching mechanism according to the embodiment.

Fig. 7 is a diagram for explaining an operation of the contact switching mechanism according to one embodiment.

Fig. 8 is a diagram for explaining an operation of the contact switching mechanism according to the embodiment.

Fig. 9 is a diagram for explaining an operation of the contact switching mechanism according to the embodiment.

Fig. 10 is a diagram for explaining an operation of the contact switching mechanism according to the embodiment.

Fig. 11 is an external perspective view of a position sensor included in the contact switching mechanism according to one embodiment.

Fig. 12 is a diagram for explaining a method of detecting the position of the slider by the position sensor included in the contact switching mechanism according to one embodiment.

Description of the reference numerals

10 electronic overload relay

11 shell body

12 cover

13 control circuit

13A circuit substrate

14 display

15 overcurrent detector

20 contact mechanism

20A first contact

20B second contact

21 first movable contact

22 first stationary contact

23 second movable contact

24 second stationary contact

100-contact switching mechanism

101 electromagnet

101A main body

101B movable shaft

101C spiral spring

101D plate-like member

102 sliding block

102A fitting portion

102B cam slot

102Ba first groove part

102Bb second groove part

102Bc third groove part

102C protrusion

103 driven parts

103A hook

104 position sensor

104A wall portion

104B wall portion

104C recess

120 manual reset mechanism

121 reset button

122 coil spring

123 push rod

123A pressing part (conversion unit)

AX central axis

P1 initial position

P2 first movement position

P3 second movement position

P4 third movement position

Detailed Description

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

(schematic configuration of electronic overload relay 10)

Fig. 1 is an external perspective view of an electronic overload relay 10 according to one embodiment, viewed from the front side (X-axis positive side). Fig. 2 is an external perspective view of the electronic overload relay 10 according to one embodiment, viewed from the bottom surface side (Z-axis negative side). Fig. 3 is an exploded perspective view of the electronic overload relay 10 according to one embodiment, as seen from the bottom surface side (Z-axis negative side).

In the following description, for convenience, the X-axis direction is set to the front-rear direction, the Y-axis direction is set to the left-right direction, and the Z-axis direction is set to the up-down direction. However, the positive X-axis direction is set to the front, the positive Y-axis direction is set to the right, and the positive Z-axis direction is set to the top.

For example, the electronic overload relay 10 is used by being connected to a motor (not shown) and an electromagnetic contactor (not shown) provided in a load circuit of the motor in order to prevent burnout of the motor due to the continuation of an overload state of the motor.

The electronic overload relay 10 has a trip function of switching the contact mechanism 20 (see fig. 4) to a trip state when an overcurrent flows through a load, a manual restoration function of manually restoring the contact mechanism 20 from the trip state to a steady state, and an automatic restoration function of automatically restoring the contact mechanism 20 from the trip state to the steady state when a predetermined time elapses.

For example, the electronic overload relay 10 draws in a load current of the motor through the overcurrent detector 15, and when the drawn load current exceeds a set value, a driving current flows from the overcurrent detector 15 to the electromagnet 101 to drive the electromagnet 101, thereby performing a trip operation for switching the contact mechanism 20 to a trip state. Specifically, in the electronic overload relay 10, after the overcurrent detector 15 draws in the load current of the motor, the control circuit 13 is driven by the load current, and the control circuit 13 detects, determines, and notifies the load current.

When the contact mechanism 20 is in the tripped state, the electronic overload relay 10 transmits a first state signal to the electromagnetic contactor to turn off the electromagnetic contactor, thereby cutting off the load circuit of the motor.

After a predetermined time has elapsed, the electronic overload relay 10 performs an automatic restoration operation of switching the contact mechanism 20 to a steady state by causing a driving current to flow to the electromagnet 101 through an automatic restoration function.

Alternatively, the electronic overload relay 10 performs the manual restoration operation of mechanically switching the contact mechanism 20 to the steady state by the manual restoration function before the predetermined time elapses.

When the contact mechanism 20 is in a steady state, the electronic overload relay 10 transmits a second state signal to the electromagnetic contactor to cause the electromagnetic contactor to perform a connection operation, thereby enabling connection of a load circuit of the motor.

As shown in fig. 3, the electronic overload relay 10 includes a case 11, a cover 12, a control circuit 13, an overcurrent detector 15, a contact mechanism 20, and a contact switching mechanism 100.

The housing 11 is a container-like member having a hollow structure. For example, the case 11 is formed using an insulating material such as a synthetic resin. The bottom surface portion of the case 11 has an opening shape, and is closed by attaching a resin cover 12 to the bottom surface portion.

The control circuit 13 is provided in the housing 11, and is configured by mounting a plurality of electronic components on a circuit board. The control circuit 13 is used to realize various functions (for example, an automatic restoration function and the like) of the electronic overload relay 10. Further, a position sensor 104 for detecting a stop position of the slider 102 included in the contact switching mechanism 100 is provided on the circuit board 13A of the control circuit 13.

The overcurrent detector 15 introduces a load current to the motor. The load current introduced through the overcurrent detector 15 drives the control circuit 13. When the load current to be introduced exceeds the set value, the control circuit 13 can drive the electromagnet 101 by flowing a drive current to the magnet 101.

The contact switching mechanism 100 is provided in the housing 11, and switches the contact mechanism 20 between a tripped state and a steady state.

(construction of contact switching mechanism 100)

Fig. 4 is a diagram showing a configuration of the contact switching mechanism 100 included in the electronic overload relay 10 according to one embodiment. Fig. 4 (a) shows the electronic overload relay 10 in a state in which the cover 12 and the control circuit 13 are removed from the bottom surface side (Z-axis negative side). Fig. 4 (b) shows a cross section of the electronic overload relay 10 from the bottom surface side (Z-axis negative side). Fig. 5 is an external perspective view of the slider 102 included in the contact switching mechanism 100 according to one embodiment.

As shown in fig. 4, in the electronic overload relay 10, the contact mechanism 20, the contact switching mechanism 100, and the manual reset mechanism 120 are provided in the housing 11.

Joint mechanism 20>

As shown in fig. 4 (b), the contact mechanism 20 includes a first movable contact 21, a first fixed contact 22, a second movable contact 23, and a second fixed contact 24. The first movable contact 21 and the first fixed contact 22 constitute a first contact 20A. The second movable contact 23 and the second fixed contact 24 constitute a second contact 20B.

In the contact mechanism 20, in a stable state, the first movable contact 21A of the first movable contact 21 abuts against the first fixed contact 22A of the first fixed contact 22, whereby the first contact 20A is in a closed state.

In the contact mechanism 20, in the steady state, the second movable contact 23A of the second movable contact 23 is separated from the second fixed contact 24A of the second fixed contact 24, and the second contact 20B is in the on state.

On the other hand, in the tripped state, the contact mechanism 20 is separated from the first fixed contact 22A of the first fixed contact 22 by the first movable contact 21A of the first movable contact 21, and the first contact 20A is turned on.

In the tripped state, the contact mechanism 20 is brought into contact with the second fixed contact 24A of the second fixed contact 24 by the second movable contact 23A of the second movable contact 23, and the second contact 20B is brought into a closed state.

Contact switching mechanism 100>

As shown in fig. 4 (a), the contact switching mechanism 100 includes an electromagnet 101, a slider 102, and a driven member 103.

< electromagnet 101>

The electromagnet 101 includes a main body 101A, a movable shaft 101B, a plate-like member 101D (armature), and a coil spring 101C.

The main body 101A is configured to have an electromagnetic coil or the like, and when energized, generates a magnetic force for moving the movable shaft 101B in the axial direction of the central axis AX.

The movable shaft 101B has a shaft shape, and is provided so as to penetrate the center of the body 101A on the central axis AX. The movable shaft 101B is movable on the central axis AX in the axial direction (Y-axis direction) of the central axis AX. For example, the movable shaft 101B is formed using iron. The movable shaft 101B is movable rightward (Y-axis positive direction) by a magnetic force generated by the main body 101A.

The plate-like member 101D is a flat plate-like member provided at the left end portion (end portion on the negative side of the Y axis) of the movable shaft 101B.

The coil spring 101C is provided so as to be expandable and contractible in the left-right direction (Y-axis direction) between the left end portion (Y-axis negative end portion) of the main body portion 101A and the plate-like member 101D. The coil spring 101C biases the plate-like member 101D and the movable shaft 101B to the left (Y-axis negative direction).

< slider 102>

The slider 102 is a resin member movable in the left-right direction (Y-axis direction). The slider 102 is coupled to the contact mechanism 20, and is movable in the left-right direction (Y-axis direction) to switch the contact mechanism 20 between a steady state and a tripped state. As shown in fig. 4 and 5, the slider 102 has a fitting portion 102A on the central axis AX. The slider 102 is coupled to the movable shaft 101B by fitting a tip end portion (end portion on the Y-axis positive side) of the movable shaft 101B into the fitting portion 102A. Thus, the slider 102 moves in the axial direction (Y-axis direction) of the movable shaft 101B in conjunction with the movable shaft 101B when the electromagnet 101 is energized. The slider 102 has a cam groove 102B forming a heart cam mechanism on the central axis AX. The cam groove 102B is provided for allowing the hook 103A of the follower member 103 to be driven. The slider 102 has a protrusion 102C protruding downward (in the negative Z-axis direction) between the fitting portion 102A and the cam groove 102B on the central axis AX. The protrusion 102C is provided for detecting the stop position of the slider 102 by the position sensor 104.

< driven Member 103>

The driven member 103 is provided on the central axis AX, and is a metallic rod-like member extending linearly along the central axis AX. The follower member 103 alternately switches the stop position after the movement of the slider 102 in the axial direction (Y-axis direction) to a first stop position corresponding to the steady state of the contact mechanism 20 and a second stop position corresponding to the tripped state of the contact mechanism 20 each time the electromagnet 101 is energized.

Specifically, the driven member 103 has a hook 103A formed by bending the driven member at a substantially right angle in the upward direction (Z-axis positive direction) at the tip end portion. The hook 103A constitutes a heart cam mechanism. The hook 103A of the follower member 103 follows the cam groove 102B of the slider 102 every time the electromagnet 101 is energized, and the stop position of the slider 102 after movement in the axial direction (Y-axis direction) is alternately switched to the first stop position and the second stop position.

Manual reset mechanism 120-

The manual reset mechanism 120 is provided to manually reset the contact mechanism 20 from the tripped state to the steady state. The manual reset mechanism 120 has a reset button 121, a coil spring 122, and a push rod 123. A part of the reset button 121 is provided to protrude to the outside of the housing 11, so that a pressing operation from the outside of the housing 11 becomes possible.

In the manual reset mechanism 120, the push rod 123 is moved in the X-axis negative direction together with the reset button 121 in accordance with the pressing operation of the reset button 121, and the slider 102 is moved in the Y-axis positive direction by pressing the slider 102 by a pressing portion 123A ("one example of the conversion unit") provided at the distal end portion of the push rod 123. Since the pressing portion 123A of the push rod 123 is inclined, the pressing portion 123A presses the slider 102, and thus the movement force of the reset button 121 in the X-axis negative direction can be converted into the movement force of the slider 102 in the Y-axis positive direction, and the slider 102 can be moved in the Y-axis positive direction.

In this way, the manual reset mechanism 120 can manually reset the contact mechanism 20 from the tripped state to the steady state by moving the slider 102 in the Y-axis forward direction, releasing the engagement of the hook 103A of the driven member 103 with the slider 102, and switching the stop position of the slider 102 from the second stop position to the first stop position.

The reset button 121 is biased in the X-axis positive direction by the coil spring 122. Thus, the reset button 121 can be automatically moved in the X-axis forward direction to be reset to the initial position when the self-pressing operation is released.

(construction of heart-shaped cam mechanism)

Fig. 6 is a diagram showing a structure of a heart cam mechanism included in the contact switching mechanism 100 according to one embodiment. Fig. 6 (a) is a plan view of the heart cam mechanism as viewed from the negative side of the Z axis. Fig. 6 (b) is a perspective view of the heart cam mechanism from the negative side of the Z axis.

As shown in fig. 6, a heart cam mechanism included in the contact switching mechanism 100 according to one embodiment includes a cam groove 102B of a slider 102 and a hook 103A of a follower 103. The heart cam mechanism is driven by the cam groove 102B by the hook 103A, and the stop position of the slider 102 after movement in the axial direction (Y-axis direction) is alternately switched to the first stop position and the second stop position.

As shown in fig. 6, the cam groove 102B has a heart-shaped groove shape recessed toward the Z-axis positive side. The cam groove 102B is configured to have a first groove 102Ba, a second groove 102Bb, and a third groove 102Bc.

The first groove 102Ba extends in the negative Y-axis direction while expanding the width of the entire cam groove 102B in the X-axis direction, starting from the initial position P1 and ending at the first movement position P2.

The second groove 102Bb is a portion extending in a V-shape in the X-axis negative direction starting from the first moving position P2 and ending at the third moving position P4. A second movement position P3 having a valley shape is provided at the intermediate position of the second groove 102 Bb.

The third groove 102Bc is a portion extending in the Y-axis positive direction with the third movement position P4 as a start point and the initial position P1 as an end point, while reducing the width of the entire cam groove 102B in the X-axis direction.

As shown in fig. 6, when the slider 102 is stopped at the first stop position corresponding to the steady state of the contact mechanism 20, the hook 103A of the driven member 103 is located at the initial position P1 as the start point of the first groove 102 Ba.

When the electromagnet 101 is energized for the first time, the slider 102 moves in the Y-axis positive direction, and the hook 103A of the follower 103 is driven in the Y-axis negative direction in the first groove 102Ba, and moves beyond the step S1 provided in the first groove 102Ba, and is positioned at the first movement position P2.

When the first energization of the electromagnet 101 is released, the slider 102 moves in the Y-axis negative direction by the biasing force from the coil spring 101C, and the hook 103A of the follower 103 is driven in the X-axis negative direction in the second groove 102Bb, and moves beyond the step S2 provided in the second groove 102Bb, and engages with the second movement position P3, which is the valley-shaped intermediate position of the second groove 102 Bb. Thereby, the movement of the slider 102 in the Y-axis negative direction is stopped, and the slider 102 is stopped at the second stop position corresponding to the tripped state of the contact mechanism 20.

Next, when the electromagnet 101 is energized a second time, the slider 102 moves in the Y-axis positive direction, and the hook 103A of the follower 103 is driven in the X-axis negative direction in the second groove 102Bb, and moves beyond the step S3 provided in the second groove 102Bb, and is positioned at the third movement position P4.

Then, by releasing the second energization of the electromagnet 101, the slider 102 moves in the Y-axis negative direction by the biasing force from the coil spring 101C, and the hook 103A of the follower 103 is driven in the Y-axis positive direction in the third groove 102Bc, and moves beyond the step S4 provided in the third groove 102Bc, and is positioned at the initial position P1. Thus, the slider 102 moves by the maximum amount in the Y-axis negative direction, and stops at the first stop position corresponding to the steady state of the contact mechanism 20.

As described above, in the heart cam mechanism included in the contact switching mechanism 100 according to one embodiment, each time the electromagnet 101 is energized, the stop position of the hook 103A of the driven member 103 is alternately switched to the initial position P1 and the second movement position P3, and the stop position after the movement of the slider 102 in the axial direction (Y-axis direction) can be alternately switched to the first stop position and the second stop position.

The heart-shaped cam mechanism of the contact switching mechanism 100 according to one embodiment is configured such that the hooks 103A of the follower 103 do not move in the opposite direction in the cam groove 102B by the steps S1 to S4 provided in the cam groove 102B.

(operation of contact switching mechanism 100)

Fig. 7 to 10 are diagrams for explaining the operation of the contact switching mechanism 100 according to one embodiment.

(initial state)

Fig. 7 shows the contact switching mechanism 100 and the contact mechanism 20 when the contact switching mechanism 100 is in the initial state.

As shown in fig. 7, in the initial state of the contact switching mechanism 100, the electromagnet 101 is not energized, and the slider 102 is stopped at the first stop position (position where it moves to the Y-axis negative side by the maximum amount). At this time, the hook 103A of the follower member 103 is located at the initial position P1 in the cam groove 102B of the slider 102.

As shown in fig. 7, when the contact switching mechanism 100 is in the initial state, the first movable contact 21A of the first movable contact 21 abuts against the first fixed contact 22A of the first fixed contact 22 with respect to the contact mechanism 20, and the first contact 20A is in the closed state.

As shown in fig. 7, when the contact switching mechanism 100 is in the initial state, the slider 102 is stopped at the first stop position, and therefore, with respect to the contact mechanism 20, the second movable contact 23A of the second movable contact 23 is separated from the second fixed contact 24A of the second fixed contact 24, and the second contact 20B is in the open state.

That is, when the contact switching mechanism 100 is in the initial state, the contact mechanism 20 is in the steady state.

As shown in fig. 7, when the contact switching mechanism 100 is in the initial state, the display 14 is in the display state.

(first powered state)

Fig. 8 shows the state of the contact mechanism 20 and the contact switching mechanism 100 when the contact switching mechanism 100 is in the first energized state (when the first energization of the electromagnet 101 is performed).

As shown in fig. 8, in the contact switching mechanism 100, in the first energized state, the electromagnet 101 is energized for the first time, and the movable shaft 101B of the electromagnet 101 moves in the Y-axis forward direction by the magnetic force generated by the electromagnet 101, and in conjunction with this, the slider 102 moves in the Y-axis forward direction. At this time, the hook 103A of the follower 103 moves from the initial position P1 to the first movement position P2 through the first groove 102Ba in the cam groove 102B of the slider 102.

As shown in fig. 8, when the contact switching mechanism 100 is in the first energized state, the slider 102 moves in the Y-axis forward direction from the first stop position, and the first movable contact 21A of the first movable contact 21 is separated from the first fixed contact 22A of the first fixed contact 22 with respect to the contact mechanism 20, so that the first contact 20A is in the open state.

As shown in fig. 8, when the contact switching mechanism 100 is in the first energized state, the slider 102 moves in the Y-axis forward direction from the first stop position, and therefore, with respect to the contact mechanism 20, the second movable contact 23A of the second movable contact 23 abuts against the second fixed contact 24A of the second fixed contact 24, and the second contact 20B is in the closed state.

That is, when the contact switching mechanism 100 is in the first energized state, the contact mechanism 20 is in the tripped state.

As shown in fig. 8, when the contact switching mechanism 100 is in the first energized state, the slider 102 is moved in the Y-axis forward direction, and the display 14 can be rotated, and the display 14 can be set to the non-display state.

(first energization released state)

Fig. 9 shows the state of the contact mechanism 20 and the contact switching mechanism 100 when the contact switching mechanism 100 is in the first energization released state (when the first energization of the electromagnet 101 is released).

As shown in fig. 9, in the first energization cancellation state, the contact switching mechanism 100 cancels the first energization of the electromagnet 101, so that the movable shaft 101B of the electromagnet 101 moves in the Y-axis negative direction by the biasing force from the coil spring 101C, and in conjunction with this, the slider 102 moves in the Y-axis negative direction. At this time, the hook 103A of the follower 103 moves from the first movement position P2 to the second movement position P3 through the second groove 102Bb in the cam groove 102B of the slider 102, and is locked at the second movement position P3. Thereby, the slider 102 is stopped at the second stop position slightly shifted in the Y-axis negative direction.

As shown in fig. 9, when the contact switching mechanism 100 is in the first energization released state, the slider 102 is stopped at the second stop position, so that the first contact 20A is maintained in the open state and the second contact 20B is maintained in the closed state with respect to the contact mechanism 20.

That is, when the contact switching mechanism 100 is in the first energization released state, the contact mechanism 20 maintains the tripped state.

(reset action course)

Fig. 10 shows the state of the contact mechanism 20 and the contact switching mechanism 100 when the contact switching mechanism 100 is in the course of the reset operation (when the reset operation of the reset button 121 provided in the manual reset mechanism 120 is performed).

As shown in fig. 10, in the contact switching mechanism 100, when the reset operation of the reset button 121 is performed from the first energization released state shown in fig. 9, the slider 102 is pressed by the pressing portion 123A of the push rod 123 provided in the manual reset mechanism 120, and the slider 102 is forcibly moved in the Y-axis forward direction.

Thereby, the hook 103A of the follower member 103 moves from the second movement position P3 to the third movement position P4 through the second groove 102Bb in the cam groove 102B of the slider 102.

As shown in fig. 10, when the contact switching mechanism 100 is in the reset operation, the slider 102 moves in the Y-axis forward direction from the second stop position, so that the first contact 20A is maintained in the open state and the second contact 20B is maintained in the closed state with respect to the contact mechanism 20.

That is, when the contact switching mechanism 100 is in the reset operation, the contact mechanism 20 maintains the tripped state.

(reset action released state)

When the contact switching mechanism 100 is in the reset operation released state (when the reset operation of the reset button 121 is released), the contact switching mechanism 100 is restored to the initial state shown in fig. 7.

Specifically, in the reset operation released state, the contact switching mechanism 100 releases the pressing from the push rod 123, and the movable shaft 101B of the electromagnet 101 moves in the Y-axis negative direction under the biasing force from the coil spring 101C, and in conjunction with this, the slider 102 moves in the Y-axis negative direction. At this time, the hook 103A of the follower 103 moves from the third movement position P4 to the initial position P1 through the third groove 102Bc in the cam groove 102B of the slider 102. Thus, the contact switching mechanism 100 returns to the initial state shown in fig. 7, and the slider 102 stops at the first stop position.

As shown in fig. 7, when the contact switching mechanism 100 returns to the initial state shown in fig. 7, the first movable contact 21A of the first movable contact 21 abuts against the first fixed contact 22A of the first fixed contact 22 with respect to the contact mechanism 20, and the first contact 20A is in the closed state.

As shown in fig. 7, when the contact switching mechanism 100 returns to the initial state shown in fig. 7, the second movable contact 23A of the second movable contact 23 is separated from the second fixed contact 24A of the second fixed contact 24 with respect to the contact mechanism 20, and the second contact 20B is in the open state.

That is, the contact switching mechanism 100 is in the reset operation released state, and when it is restored to the initial state, the contact mechanism 20 is restored to the stable state.

When the contact switching mechanism 100 returns to the initial state, the slider 102 moves in the Y-axis negative direction, and the display 14 can be reversely rotated, thereby setting the display 14 to the display state.

(automatic recovery function)

In addition to the reset operation state and the reset operation release state (i.e., the manual reset function), the contact switching mechanism 100 may be configured to restore the contact mechanism 20 to the stable state by being in the second energized state and the second energized and disengaged state (i.e., the automatic reset function).

Specifically, in the contact switching mechanism 100, when a predetermined time elapses from the first energization released state shown in fig. 9, the electromagnet 101 is energized a second time by the electric power stored in the capacitor 16 (see fig. 3) at the normal time, and the second energization state is set.

In the second energized state, the contact switching mechanism 100 energizes the electromagnet 101a second time, and the movable shaft 101B of the electromagnet 101 moves in the Y-axis forward direction by the magnetic force generated by the electromagnet 101, and in conjunction with this, the slider 102 moves in the Y-axis forward direction. At this time, the hook 103A of the follower member 103 moves from the second movement position P3 to the third movement position P4 through the second groove 102Bb within the cam groove 102B of the slider 102.

When the contact switching mechanism 100 is in the second energized state, the slider 102 moves in the Y-axis positive direction from the second stop position, so that the first contact 20A is maintained in the open state and the second contact 20B is maintained in the closed state with respect to the contact mechanism 20.

That is, when the contact switching mechanism 100 is in the second energized state, the contact mechanism 20 maintains the tripped state.

When the electromagnet 101 is energized for the second time, the contact switching mechanism 100 is turned off, and the second energization and removal state is set, and the initial state shown in fig. 7 is restored.

Specifically, in the second on-state, the contact switching mechanism 100 releases the second energization of the electromagnet 101, so that the movable shaft 101B of the electromagnet 101 moves in the Y-axis negative direction under the biasing force from the coil spring 101C, and the slider 102 moves in the Y-axis negative direction in conjunction with this movement. At this time, the hook 103A of the follower 103 moves from the third movement position P4 to the initial position P1 through the third groove 102Bc in the cam groove 102B of the slider 102. Thus, the contact switching mechanism 100 returns to the initial state shown in fig. 7, and the slider 102 stops at the first stop position.

That is, the contact switching mechanism 100 is in the second on-state, and when it returns to the initial state, the contact mechanism 20 returns to the steady state.

(detection Unit)

Fig. 11 is an external perspective view of the position sensor 104 included in the contact switching mechanism 100 according to one embodiment. Fig. 12 is a diagram for explaining a method of detecting the position of the slider 102 by the position sensor 104 included in the contact switching mechanism 100 according to one embodiment.

The contact switching mechanism 100 of one embodiment includes a position sensor 104 as an example of a "detection unit" for detecting the position of the slider 102. As shown in fig. 11, the position sensor 104 has a recess 104C between a wall portion 104A and a wall portion 104B that are opposed to each other.

As shown in fig. 12, the position sensor 104 is mounted on the circuit board 13A of the control circuit 13 such that the protrusion 102C of the slider 102 can pass through the recess 104C.

As shown in fig. 12 (a), when the slider 102 is stopped at the first stop position corresponding to the steady state of the contact mechanism 20, the protrusion 102C of the slider 102 is positioned in the recess 104C of the position sensor 104. Thus, in the position sensor 104, the detection medium (for example, light or the like) that propagates between the wall portion 104A and the wall portion 104B is blocked by the protrusion 102C, and thus the slider 102 can be stopped at the first stop position for detection.

On the other hand, as shown in fig. 12 b, when the slider 102 is stopped at the second stop position corresponding to the steady state of the contact mechanism 20, the protrusion 102C of the slider 102 is located outside (on the Y-axis positive side) of the recess 104C of the position sensor 104. Thus, with the position sensor 104, since the detection medium (for example, light or the like) propagating between the wall portion 104A and the wall portion 104B is no longer blocked by the protrusion portion 102C, it is possible to stop detecting the slider 102 at the second stop position.

Since the contact switching mechanism 100 according to one embodiment can detect the stop position of the slider 102 by the position sensor 104, even when the contact mechanism 20 is restored to the steady state by the manual restoring function, it is possible to detect that the contact mechanism 20 is restored to the steady state.

(Effect)

As described above, the electronic overload relay 10 according to one embodiment includes the contact mechanism 20 capable of switching between the steady state and the tripped state, the electromagnet 101 having the movable shaft 101B that moves in the axial direction when energized, the slider 102 that moves in the axial direction in conjunction with the movable shaft 101B when energized, and the follower member 103 that alternately switches the stopped position after the movement of the slider 102 in the axial direction to the first stopped position corresponding to the steady state and the second stopped position corresponding to the tripped state every time the electromagnet 101 is energized.

Thus, in the electronic overload relay 10 according to one embodiment, the contact mechanism 20 can be switched between the steady state and the tripped state by using 1 electromagnet instead of using a permanent magnet, and therefore the number of components used for switching the contact mechanism 20 can be reduced, and thus, the cost and the size can be reduced.

Further, since the electronic overload relay 10 according to one embodiment does not require a permanent magnet, occurrence of a locking failure due to a decrease in magnetic force at a low temperature can be suppressed.

In the electronic overload relay 10 according to one embodiment, the slider 102 includes the cam groove 102B that constitutes a heart-shaped cam mechanism, the follower member 103 includes the hook 103A that constitutes a heart-shaped cam mechanism at the tip end portion, and each time the electromagnet 101 is energized, the hook 103A follows the cam groove 102B, so that the stop position of the slider 102 after the movement in the axial direction is alternately switched to the first stop position and the second stop position.

As a result, in the electronic overload relay 10 according to one embodiment, the contact mechanism 20 can be switched between the steady state and the tripped state by the cam groove 102B and the hook 103A, and the number of components used for switching the contact mechanism 20 can be reduced, so that the cost and the size can be reduced.

In addition, the electronic overload relay 10 according to one embodiment includes a manual reset mechanism 120 for manually resetting the contact mechanism 20 from the tripped state to the steady state.

Thus, the electronic overload relay 10 according to one embodiment can manually restore the contact mechanism 20 from the tripped state to the steady state without energizing the electromagnet 101.

In addition, the electronic overload relay 10 of one embodiment includes a position sensor 104 that detects a stop position of the slider 102 in the axial direction.

Thus, in the contact switching mechanism 100 according to the embodiment, the position sensor 104 can detect the stop position of the slider 102, and therefore, even when the contact mechanism 20 is restored to the steady state by the manual reset mechanism 120, the contact mechanism 20 can be detected as being restored to the steady state.

In the electronic overload relay 10 according to one embodiment, the manual reset mechanism 120 includes the reset button 121, and the slider 102 is moved in the axial direction in response to the pressing operation of the reset button 121, and the stop position of the slider 102 is switched from the second stop position to the first stop position, whereby the contact mechanism 20 can be manually reset.

Thus, the electronic overload relay 10 according to one embodiment can realize the manual reset mechanism 120 by a relatively simple configuration in which the slider 102 is moved in the axial direction by using the reset button 121.

In the electronic overload relay 10 according to one embodiment, the manual reset mechanism 120 includes a pressing portion 123A that converts the axial moving force of the reset button 121 associated with the pressing operation into the axial moving force of the slider 102.

Thus, the electronic overload relay 10 according to one embodiment can dispose the reset button 121 such that the pressing operation direction of the reset button 121 is orthogonal to the moving direction of the slider 102.

Although the preferred embodiments of the present invention have been described in detail, the present invention is not limited to these embodiments, and various modifications and changes can be made within the gist of the present invention described in the claims.

Claims

1. An electronic overload relay comprising:

a contact mechanism capable of switching between a steady state and a tripped state;

an electromagnet having a movable shaft that moves in an axial direction when energized;

a slider that moves in the axial direction in conjunction with the movable shaft when the current is supplied; and

and a driven member that alternately switches a stop position of the slider after the movement in the axial direction to a first stop position corresponding to the steady state and a second stop position corresponding to the trip state each time the electromagnet is energized.

2. An electronic overload relay according to claim 1 wherein,

the slider has a cam groove constituting a heart cam mechanism,

the follower member includes a hook portion constituting the heart-shaped cam mechanism at a distal end portion thereof, and the hook portion is driven by the cam groove each time the electromagnet is energized, thereby alternately switching a stop position of the slider after movement in the axial direction to the first stop position and the second stop position.

3. An electronic overload relay according to claim 2 wherein,

and a manual reset mechanism for manually resetting the contact mechanism from the tripped state to the steady state.

4. An electronic overload relay according to claim 3 wherein,

the device includes a detection unit for detecting a stop position of the slider in the axial direction.

5. The electronic overload relay of claim 4 wherein,

the manual reset mechanism is provided with a reset button,

and a manual return unit configured to return the contact mechanism to the manual return position by moving the slider in the axial direction in response to a pressing operation of the reset button and switching a stop position of the slider from the second stop position to the first stop position.

6. The electronic overload relay of claim 5 wherein,

the manual reset mechanism includes a conversion unit that converts a force of moving the reset button in the axial direction in response to the pressing operation into a force of moving the slider in the axial direction.