Contact bistable switching control mechanism of thermal relay and thermal relay

Abstract

The invention discloses a contact bistable switching control mechanism of a thermal relay and the thermal relay, and the mechanism comprises a housing, a movable spring push rod movably disposed on the housing, a switching rod disposed corresponding to the movable spring push rod, and an action reed connected with the movable spring push rod. The movable spring push rod is provided with a bistable switching minimum action stroke corresponding to a shear dead point of an action reed of the thermal relay, the switching rod is provided with a switchable limiting action position and a switchable limiting release position relative to the shell, and the movable spring push rod and the switching rod are provided with a first limiting part and a second limiting part respectively. And when the switching rod is pushed to the limiting action position, the second limiting part moves to the motion path of the first limiting part, and when the movable spring push rod acts, the second limiting part can be in limiting fit with the first limiting part so as to limit the action stroke of the movable spring push rod to be smaller than the minimum action stroke of bistable switching. According to the invention, the switching rod can be used for manually controlling whether the contacts are switched in a bistable state or not, and the application range of the thermal relay is widened.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of thermal relay, in particular to a contact bistable switching control mechanism of a thermal relay and the thermal relay. BACKGROUND

[0002] The thermal relay is also called a relay, but it is obviously different from the existing conventional relay. Specifically, the relay refers to an electrical element whose contact acts when the input signal (current, voltage, temperature, etc.) reaches the set value, and the relay realizes the switching, control, amplification or isolation of the circuit. The thermal relay is a relay that is specially used for motor or electrical equipment overload protection only by using the principle of current thermal effect, and only provides protection for "long-term overload" to prevent damage to the equipment due to continuous overcurrent. The existing thermal relay has a moving spring push rod connected with the moving spring piece of the contact and a moving spring piece driving the moving spring push rod to act, the moving spring piece has a shear dead point, and the moving spring piece cannot be reset to the initial state by relying on its own elastic force after passing the shear dead point under external force. Based on this, the moving spring push rod can be moved by the moving spring piece under the action of external force, and then the contact is controlled by the moving spring push rod to switch between the normally open and normally closed or the normally closed and normally open bistable states. However, the existing thermal relay cannot manually control whether the contact switches between the bistable states, which limits its application. SUMMARY

[0003] In view of the deficiencies of the prior art, the present application provides a contact bistable switching control mechanism of a thermal relay, which mainly solves the technical problem that the existing thermal relay cannot manually control whether the contact switches between the bistable states, which limits its application.

[0004] To achieve the above purpose, the present application is realized by the following technical scheme: A contact bistable switching control mechanism of a thermal relay, comprising a shell, a moving spring push rod movably arranged on the shell, a switching rod correspondingly arranged with the moving spring push rod, and a moving spring piece connected with the moving spring push rod, the moving spring push rod has a bistable switching minimum action stroke corresponding to the shear dead point of the moving spring piece of the thermal relay, the switching rod has a switchable limiting position and a position where the limiting is released relative to the shell, the first limiting portion and the second limiting portion are respectively arranged on the moving spring push rod and the switching rod, and when the switching rod is pushed to the limiting position, the second limiting portion moves to the movement path of the first limiting portion, and the first limiting portion and the second limiting portion can be limited to limit the action stroke of the moving spring push rod to be less than the bistable switching minimum action stroke when the moving spring push rod acts.

[0005] Further, when the switching rod is reset to the un-limited position, the second limiting part exits the movement path of the first limiting part, and further releases the action stroke limitation of the dynamic spring push rod, so that the action stroke of the dynamic spring push rod is greater than the minimum action stroke of the bistable switching, so that the thermal relay action spring can overcome the dead point under the action of external force.

[0006] Further, the switching rod has a handle part exposed to the shell.

[0007] Further, the dynamic spring push rod is provided with a clamping groove, and the end of the thermal relay action spring is clamped in the clamping groove, so that the dynamic spring push rod and the thermal relay action spring are linked.

[0008] Further, the clamping groove is provided with a left displacement inclined surface and a right displacement inclined surface corresponding to the left and right swing directions of the thermal relay action spring during the bistable switching.

[0009] Further, the inner wall of the clamping groove is provided with a left circular arc convex part and a right circular arc convex part arranged oppositely, and the end of the thermal relay action spring is clamped in the interval gap between the left circular arc convex part and the right circular arc convex part, so that the end of the thermal relay action spring is in point contact with the inner wall of the clamping groove.

[0010] Based on the same inventive concept, the present application also provides a thermal relay comprising the contact bistable switching control mechanism of any one of the above-mentioned thermal relays, and the thermal relay further comprises a main circuit load monitoring system, an action mechanism transmission system and an auxiliary signal output system, the main circuit load monitoring system comprises a bimetallic element and a contact plate, the auxiliary signal output system comprises a dynamic spring push rod, an NC auxiliary contact and an NO auxiliary contact, the dynamic spring push rod is configured to be connected with the dynamic springs of the NC auxiliary contact and the NO auxiliary contact and drive the two dynamic springs to act synchronously, and the action mechanism transmission system comprises a guide plate structure, a compensation bimetallic element, an action push rod support, a switching action mechanism assembly, a setting current knob and an action mechanism knob.

[0011] The above technical solution has the following advantages or beneficial effects:

[0012] The contact bistable switching control mechanism of the thermal relay and the thermal relay have switchable limiting position and unlimiting position of the switch rod relative to the shell, and the first limiting part and the second limiting part are respectively arranged on the moving spring push rod and the switch rod, so that the switch rod can be manually pushed to move to the preset limiting position, at this time, the second limiting part will enter the movement path of the first limiting part, under the action of external force, the thermal relay action spring oscillates and drives the moving spring push rod to act until the first limiting part and the second limiting part form limiting cooperation, and the action stroke of the moving spring push rod is limited to be less than the minimum action stroke of the bistable switching, thereby the oscillation amplitude of the thermal relay action spring is reversely limited by the limiting cooperation of the first limiting part and the second limiting part and cannot cross the shear dead point, so that the contact structure of the thermal relay does not perform bistable switching, and when the external force disappears, the thermal relay action spring is reset under the action of its own elastic force and drives the moving spring push rod to return to the initial state position. When needed, the switch rod can be manually pushed to exit the limiting position to the unlimiting position, so that the second limiting part exits the movement path of the first limiting part, so that under the action of external force, the thermal relay action spring can drive the moving spring push rod to oscillate, and since the stroke of the moving spring push rod is limited by the second limiting part, the thermal relay action spring can oscillate to cross the shear dead point under the action of external force, and then the corresponding contact moving spring is driven by the moving spring push rod to perform bistable switching. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 It is a structure schematic diagram of the thermal relay of the embodiment of the present application.

[0014] Figure 2 It is another structure schematic diagram of the thermal relay of the embodiment of the present application.

[0015] Figure 3 It is a structure schematic diagram of the contact bistable switching control mechanism of the embodiment of the present application.

[0016] Figure 4 It is a cooperation structure schematic diagram of the moving spring push rod and the switch rod of the embodiment of the present application (unlimited cooperation state).

[0017] Figure 5 It is a cooperation structure schematic diagram of the moving spring push rod and the switch rod of the embodiment of the present application (forming limiting cooperation state).

[0018] Figure 6 It is a cooperation structure schematic diagram of the moving spring push rod and the action spring of the embodiment of the present application.

[0019] Figure 7 It is Figure 6 A local enlarged view in the A of the figure.

[0020] Figure 8is another angle cooperation structure schematic diagram of the moving spring push rod and the action spring sheet of the embodiment of the present application.

[0021] Figure 9 is still another angle cooperation structure schematic diagram of the moving spring push rod and the action spring sheet of the embodiment of the present application.

[0022] Figure 10 is a three-dimensional structure exploded schematic diagram of the thermal relay of the embodiment of the present application.

[0023] Figure 11 is another angle three-dimensional structure exploded schematic diagram of the thermal relay of the embodiment of the present application.

[0024] Figure 12 is an internal structure schematic diagram of the thermal relay of the embodiment of the present application.

[0025] Figure 13 is another internal structure schematic diagram of the thermal relay of the embodiment of the present application.

[0026] Label explanation:

[0027] 1, shell, 2, moving spring push rod, 3, switching rod, 4, action spring sheet, 5, NC auxiliary contact, 6, NO auxiliary contact, 7, main circuit load monitoring system, 8, action mechanism transmission system, 9, auxiliary signal output system, 21, first limiting part, 22, clamping groove, 31, second limiting part, 32, handle part, 41, shear dead point, 221, left displacement inclined surface, 222, right displacement inclined surface, 223, left circular arc convex part, 224, right circular arc convex part. DETAILED DESCRIPTION

[0028] The present application will be further described below in conjunction with the drawings and embodiments.

[0029] In the description of the present application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0030] Please refer to the drawings Figure 1 to the drawings Figure 13The embodiment of the present application provides a contact bistable switching control mechanism of a thermal relay (the contact bistable switching control mechanism refers to a control mechanism for switching the contact structure of the thermal relay from the normally open structure to the normally closed structure or from the normally closed structure to the normally open structure), which comprises a shell 1, a movable spring push rod 2 movably arranged on the shell 1 (in the embodiment, the movable spring push rod 2 is configured to be connected with the movable spring pieces of the NC auxiliary contact 5 and the NO auxiliary contact 6 and drive the two movable spring pieces to move synchronously), a switching rod 3 arranged correspondingly with the movable spring push rod 2, and a movable spring piece 4 connected with the movable spring push rod 2, the movable spring push rod 2 has a bistable switching minimum action stroke corresponding to the shear dead point 41 of the thermal relay movable spring piece 4, the switching rod 3 has a switchable limiting position and a position where the limiting is removed relative to the shell 1, the movable spring push rod 2 and the switching rod 3 are respectively provided with a first limiting part 21 and a second limiting part 31, and when the switching rod 3 is pushed to the limiting position, the second limiting part 31 moves to the movement path of the first limiting part 21 and can be limited with the first limiting part 21 to limit the action stroke of the movable spring push rod 2 to be less than the bistable switching minimum action stroke (the bistable switching minimum action stroke refers to the movement stroke of the movable spring push rod 2 from the starting point to the moment when the thermal relay movable spring piece 4 just swings to the shear dead point) when the movable spring push rod 2 moves. Further, when the switching rod 3 is reset to the position where the limiting is removed, the second limiting part 31 exits the movement path of the first limiting part 21, thereby removing the action stroke limitation of the movable spring push rod 2, so that the action stroke of the movable spring push rod 2 is greater than the bistable switching minimum action stroke, so that the thermal relay movable spring piece 4 can pass the shear dead point 41 under the action of external force. Further, the switching rod 3 has a handle 32 exposed to the shell 1.

[0031] It can be understood that in the embodiment, the switching rod 3 has switchable limiting position and unlimiting position relative to the shell 1, and the moving spring push rod 2 and the switching rod 3 are respectively provided with the first limiting part 21 and the second limiting part 31. Thus, the switching rod 3 can be manually pushed to move to the preset limiting position. At this time, the second limiting part 31 will enter the movement path of the first limiting part 21. Under the action of external force, the thermal relay action spring 4 swings and drives the moving spring push rod 2 to act until the first limiting part 21 and the second limiting part 31 form limiting cooperation (limiting the movement of the moving spring push rod 2 in the direction of increasing stroke but not limiting the reset of the moving spring push rod 2), and the action stroke of the moving spring push rod 2 is limited to be less than the minimum action stroke of the bistable switching. Thus, the limiting cooperation of the first limiting part 21 and the second limiting part 31 reversely limits the swing amplitude of the thermal relay action spring 4 and makes it unable to pass the switching dead point, so that the contact structure of the thermal relay does not perform bistable switching. When the external force disappears, the thermal relay action spring 4 is reset under the action of its own elastic force and drives the moving spring push rod 2 to return to the initial state position. When needed, the switching rod 3 can be manually pushed to exit the limiting position to the unlimiting position, so that the second limiting part 31 exits the movement path of the first limiting part 21. Thus, under the action of external force, the thermal relay action spring 4 can swing to drive the moving spring push rod 2. Since the stroke of the moving spring push rod 2 loses the limitation of the second limiting part 31, the thermal relay action spring 4 can swing to pass the switching dead point 41 under the action of external force, and then drive the corresponding contact spring to perform bistable switching through the moving spring push rod 2. Thus, the switching rod 3 can be used to manually control whether the contact performs bistable switching, which improves the application range of the thermal relay.

[0032] Please refer to the accompanying drawings Figure 1 to the accompanying drawings Figure 9In one preferred embodiment, the moving spring push rod 2 is provided with a clamping groove 22, and the end of the thermal relay action spring 4 is clamped in the clamping groove 22, so that the moving spring push rod 2 and the thermal relay action spring 4 are linked. Preferably, the clamping groove 22 is provided with a left displacement inclined surface 221 and a right displacement inclined surface 222 corresponding to the left and right swinging directions of the thermal relay action spring 4 in the bistable state switching. Further, the inner wall of the clamping groove 22 is provided with a left circular arc convex portion 223 and a right circular arc convex portion 224 arranged oppositely, and the end of the thermal relay action spring 4 is clamped in the interval gap between the left circular arc convex portion 223 and the right circular arc convex portion 224, so that the end of the thermal relay action spring 4 is in point contact with the inner wall of the clamping groove 22. In this embodiment, since the thermal relay action spring 4 has a certain structural elastic deformation in the two states of switching, the end of the thermal relay action spring 4 matched with the clamping groove 22 is in a certain angle inclined shape, so that the left displacement inclined surface 221 and the right displacement inclined surface 222 corresponding to the left and right swinging directions of the thermal relay action spring 4 in the bistable state switching are arranged in the clamping groove 22, which can improve the adaptability of the clamping groove 22 and the thermal relay action spring 4. At the same time, the end of the thermal relay action spring 4 is clamped in the interval gap between the left circular arc convex portion 223 and the right circular arc convex portion 224, so that the end of the thermal relay action spring 4 is in point contact with the inner wall of the clamping groove 22, which can reduce the friction between the thermal relay action spring 4 and the clamping groove 22, and improve the smoothness and displacement accuracy of the moving spring push rod 2.

[0033] Please refer to the accompanying drawings Figure 1 to the accompanying drawings Figure 9In one embodiment of the present application, a thermal relay is also provided, which comprises the bistable contact switching control mechanism of any one of the above-described thermal relays. Preferably, the thermal relay further comprises a main circuit load monitoring system 7, an action mechanism transmission system 8, and an auxiliary signal output system 9. The main circuit load monitoring system 7 comprises a bimetallic element 71 and a contact plate 72, the auxiliary signal output system 9 comprises a moving spring push rod 2, an NC auxiliary contact 5, and an NO auxiliary contact 6, and the moving spring push rod 2 is configured to be connected to the moving spring blades of the NC auxiliary contact 5 and the NO auxiliary contact 6 and drive the two moving spring blades to move synchronously. The action mechanism transmission system 8 comprises a guide plate structure 81, a compensation bimetallic element 82, an action push rod support 83, a switching action mechanism assembly 84, a setting current knob 85, and an action mechanism knob 86. Specifically, the working principle is as follows: the bimetallic element in the main circuit load monitoring system 7 is connected in series with the load circuit, and the thermal element outside the bimetallic element expands and bends under the thermal effect of the current. When the load is in an overload or open-phase abnormal condition, the bimetallic element increases the bending deflection to push the bistable action spring blades of the action mechanism transmission system 8 to move and switch. The action spring blades pull the moving spring push rod in the auxiliary signal output system 9 to switch the states of the NO auxiliary contact and the NC auxiliary contact, and output an electrical signal.

[0034] The above-described embodiments are only used to illustrate the technical solutions of the present application, but not limit the present application; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacements for part of the technical features; and these modifications or replacements do not make the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, therefore, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

Claims

1. A contact bistable switching control mechanism for a thermal relay, characterized in that: The device includes a housing (1), a spring push rod (2) movably mounted on the housing (1), a switching rod (3) corresponding to the spring push rod (2), and an action spring (4) connected to the spring push rod (2). The spring push rod (2) has a bistable switching minimum travel corresponding to the shear dead point (41) of the thermal relay action spring (4). The switching rod (3) has a switchable limiting position and a releasing position relative to the housing (1). The spring push rod (2) and the switching rod (3) are respectively provided with a first limiting part (21) and a second limiting part (31). When the switching rod (3) is pushed to the limiting position, the second limiting part (31) moves into the movement path of the first limiting part (21) and can cooperate with the first limiting part (21) when the spring push rod (2) moves to limit the travel of the spring push rod (2) to less than the bistable switching minimum travel.

2. The contact bistable switching control mechanism of the thermal relay according to claim 1, characterized in that: When the switching lever (3) is reset to the release limit position, the second limit part (31) exits the movement path of the first limit part (21), thereby releasing the travel limit on the moving spring push rod (2), so that the travel of the moving spring push rod (2) is greater than the minimum travel of the bistable switching, so that the thermal relay action spring (4) can pass its shear dead point (41) under the action of external force.

3. The contact bistable switching control mechanism of the thermal relay according to claim 1, characterized in that: The switching lever (3) has a handle (32) exposed outside the housing (1).

4. The contact bistable switching control mechanism of the thermal relay according to any one of claims 1 to 3, characterized in that: The moving spring push rod (2) is provided with a snap-fit ​​groove (22), and the end of the thermal relay actuating spring (4) is snapped into the snap-fit ​​groove (22), thereby making the moving spring push rod (2) and the thermal relay actuating spring (4) linked together.

5. The contact bistable switching control mechanism of the thermal relay according to claim 4, characterized in that: The slot (22) is provided with a left clearance slope (221) and a right clearance slope (222) that correspond to the left and right swing direction of the thermal relay action spring (4) during bistable switching.

6. The contact bistable switching control mechanism of the thermal relay according to claim 4, characterized in that: The inner wall of the snap-fit ​​groove (22) is provided with a left circular arc protrusion (223) and a right circular arc protrusion (224) arranged opposite to each other. The end of the thermal relay actuating spring (4) is adapted to snap into the gap between the left circular arc protrusion (223) and the right circular arc protrusion (224), thereby making the end of the thermal relay actuating spring (4) form a point contact with the inner wall of the snap-fit ​​groove (22).

7. A thermal relay, characterized in that: The contact bistable switching control mechanism of the thermal relay as described in any one of claims 1 to 6.

8. The thermal relay according to claim 7, characterized in that: The thermal relay also includes a main circuit load monitoring system (7), an action mechanism transmission system (8), and an auxiliary signal output system (9).

9. The thermal relay according to claim 8, characterized in that: The auxiliary signal output system (9) includes a moving spring push rod (2), an NC auxiliary contact (5) and a NO auxiliary contact (6). The moving spring push rod (2) is configured to connect with the moving springs of the NC auxiliary contact (5) and the NO auxiliary contact (6) and drive the two moving springs to move synchronously.

10. The thermal relay according to claim 8, characterized in that: The main circuit load monitoring system (7) includes a bimetallic element (71) and a contact plate (72), and the action mechanism transmission system (8) includes a guide plate structure (81), a compensating bimetallic element (82), an action push rod support (83), a switching action mechanism assembly (84), a setting current knob (85), and an action mechanism knob (86).

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