CN117612910B - Anti-impact miniature circuit breaker - Google Patents
Anti-impact miniature circuit breaker Download PDFInfo
- Publication number
- CN117612910B CN117612910B CN202311539655.1A CN202311539655A CN117612910B CN 117612910 B CN117612910 B CN 117612910B CN 202311539655 A CN202311539655 A CN 202311539655A CN 117612910 B CN117612910 B CN 117612910B
- Authority
- CN
- China
- Prior art keywords
- elastic arm
- circuit breaker
- miniature circuit
- contact
- bimetallic
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 239000010949 copper Substances 0.000 claims abstract description 23
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims abstract description 21
- 229910052802 copper Inorganic materials 0.000 claims abstract description 19
- 238000003466 welding Methods 0.000 claims description 35
- 229910045601 alloy Inorganic materials 0.000 claims description 30
- 239000000956 alloy Substances 0.000 claims description 30
- 239000002184 metal Substances 0.000 claims description 9
- 229910052751 metal Inorganic materials 0.000 claims description 9
- 229910000881 Cu alloy Inorganic materials 0.000 claims description 4
- 229910003286 Ni-Mn Inorganic materials 0.000 claims description 4
- 230000002159 abnormal effect Effects 0.000 claims description 4
- 229910000599 Cr alloy Inorganic materials 0.000 claims description 3
- 229910001030 Iron–nickel alloy Inorganic materials 0.000 claims description 3
- 229910000914 Mn alloy Inorganic materials 0.000 claims description 3
- 229910018054 Ni-Cu Inorganic materials 0.000 claims description 3
- 229910018481 Ni—Cu Inorganic materials 0.000 claims description 3
- 239000000463 material Substances 0.000 claims description 3
- 229910017518 Cu Zn Inorganic materials 0.000 claims description 2
- 229910017752 Cu-Zn Inorganic materials 0.000 claims description 2
- 229910017943 Cu—Zn Inorganic materials 0.000 claims description 2
- TVZPLCNGKSPOJA-UHFFFAOYSA-N copper zinc Chemical compound [Cu].[Zn] TVZPLCNGKSPOJA-UHFFFAOYSA-N 0.000 claims description 2
- 238000000926 separation method Methods 0.000 abstract description 7
- 238000012545 processing Methods 0.000 description 12
- 238000006073 displacement reaction Methods 0.000 description 10
- 230000006872 improvement Effects 0.000 description 9
- 230000001965 increasing effect Effects 0.000 description 9
- 238000000034 method Methods 0.000 description 9
- 238000005452 bending Methods 0.000 description 8
- 238000013461 design Methods 0.000 description 8
- 238000010586 diagram Methods 0.000 description 8
- 230000008901 benefit Effects 0.000 description 7
- 230000008569 process Effects 0.000 description 7
- 230000000052 comparative effect Effects 0.000 description 6
- 238000005516 engineering process Methods 0.000 description 5
- 239000000126 substance Substances 0.000 description 5
- 230000009471 action Effects 0.000 description 4
- 238000005381 potential energy Methods 0.000 description 4
- 125000006850 spacer group Chemical group 0.000 description 4
- 229910017873 Cu—Ni—Si—Mg Inorganic materials 0.000 description 3
- 230000003247 decreasing effect Effects 0.000 description 3
- 230000007547 defect Effects 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 230000001939 inductive effect Effects 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 229910017985 Cu—Zr Inorganic materials 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 238000003754 machining Methods 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 229910001297 Zn alloy Inorganic materials 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 230000006698 induction Effects 0.000 description 1
- 238000011031 large-scale manufacturing process Methods 0.000 description 1
- 238000010295 mobile communication Methods 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 230000002195 synergetic effect Effects 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H71/00—Details of the protective switches or relays covered by groups H01H73/00 - H01H83/00
- H01H71/02—Housings; Casings; Bases; Mountings
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H37/00—Thermally-actuated switches
- H01H37/02—Details
- H01H37/32—Thermally-sensitive members
- H01H37/52—Thermally-sensitive members actuated due to deflection of bimetallic element
- H01H37/54—Thermally-sensitive members actuated due to deflection of bimetallic element wherein the bimetallic element is inherently snap acting
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H71/00—Details of the protective switches or relays covered by groups H01H73/00 - H01H83/00
- H01H71/10—Operating or release mechanisms
Landscapes
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Thermally Actuated Switches (AREA)
Abstract
The invention belongs to the technical field of circuit breakers, and in particular relates to an anti-impact miniature circuit breaker which comprises the following components: a housing; an elastic arm, one end of which is provided with a movable contact, and the other end of which extends out from one side of the shell; a fixed arm, one end of which is provided with a fixed contact, and the other end of which extends out from the other side of the shell; the bimetallic strip assembly comprises a plurality of bimetallic strips which are arranged below the elastic arm and are stacked, and adjacent bimetallic strips are connected end to end; the heat-conducting copper plate, the elastic arm and the bimetallic strip component are connected with the heat-conducting copper plate; in the working state, the movable contact and the fixed contact form a concave-convex embedded contact structure. The concave-convex embedded structure formed when the contacts are contacted effectively prevents the separation of the movable contact and the fixed contact in the vertical direction and the horizontal direction caused by strong impact, not only can ensure good contact between the contacts when the device normally works, but also can effectively prevent the sudden cutting-off of a circuit caused by strong external force impact.
Description
Technical Field
The invention belongs to the technical field of circuit breakers, and particularly relates to an anti-impact miniature circuit breaker which can be used as a circuit protection component in portable electronic products such as mobile communication equipment, notebook computers and the like.
Background
In portable electronic devices widely used at present, circuit protection components are mainly of three types: positive temperature coefficient effect thermistors (PTC), fuses, miniature circuit breakers, and the like. For PTC, the impedance is lower at normal temperature, and when the temperature is higher than the Curie point, the impedance value is increased sharply along with the temperature rise, so that the circuit current is reduced effectively, and the circuit is protected; the fuse is fused when the temperature reaches the set temperature, so that the circuit is cut off; the miniature circuit breaker breaks the circuit by separating the movable contact from the fixed contact when the temperature reaches a set temperature.
Among them, PTC has the following disadvantages: in the state of no tripping, the impedance value is larger than the contact resistance of the contact, and when the device is applied to high-current equipment, the power loss is large; and the fuse cannot be reused after being blown. Although the miniature circuit breaker has the advantages of small contact impedance value, effective reduction of power loss during high-current operation and the like, the miniature circuit breaker has the problem that the movable contact is separated from the fixed contact due to strong impact (such as dropping or violent vibration caused by external force) so as to cause sudden circuit disconnection and the like. Therefore, the miniature circuit breaker overcomes the defects while maintaining the excellent characteristics of the miniature circuit breaker, and has a certain practical significance for improving the working stability of devices and the reliability of the devices under extremely severe conditions.
The design principle of the miniature circuit breaker is that a bimetal is arranged between a movable contact and a fixed contact, when the temperature reaches a set temperature, the bimetal is reversed, so that the movable contact is separated from the fixed contact, and the contact is switched to an off state. In the case of a miniature circuit breaker, the movable contact is usually disposed at the end of the elastic arm, and the contact pressure between the movable contact and the fixed contact is weak, so that when the structure is impacted by a strong external force, such as dropping, jolting or other mechanical external forces, the device will generate intense vibration, thereby causing the movable contact to separate from the fixed contact and interrupting the current instantaneously. One of the solutions is to provide a spacer in the housing, and to reduce the gap between the components by the spacer, thereby preventing momentary disconnection due to vibration. However, for miniature circuit breakers having an overall thickness of less than 1mm and an open contact spacing of about 100 μm, such designs are extremely difficult to manufacture in practice because of the extremely high precision required for the machining and assembly of the components. In addition, when designing the device, a space is reserved for the inversion of the bimetal and the deformation of the elastic arm, and the introduction of the spacer further increases the design and manufacturing difficulty of the device.
As described above, in the miniature circuit breaker, the weak contact pressure between the movable contact and the fixed contact is a factor of easy detachment of the two. In this type of device, the movable contact is usually located at the end of the elastic arm, and the pressure applied to the fixed contact is caused by the elastic potential energy generated by the bending deformation of the elastic arm, so that the contact pressure between the contacts can be increased by properly increasing the elastic potential energy of the elastic arm, so that the contact separation caused by vibration can be prevented more effectively, and this can be achieved by properly selecting the material of the elastic arm and properly designing and processing, such as properly increasing the thickness, width, bending degree, etc. of the elastic arm. The method has no extra requirement on the machining precision of the parts, does not need to introduce a spacer, and is suitable for low-cost large-scale production.
However, in the miniature circuit breaker, when the bimetal is small in size, the thickness thereof is generally less than 100 μm, and the lateral dimension (length, width, diameter, etc.) is less than 4mm, if the pressure applied to the fixed arm (fixed contact is disposed at the end) by the elastic arm (movable contact is disposed at the end) is too large, the thermal thrust generated when the bimetal is reversed will not be enough to push the elastic arm open, and thus the current cannot be cut off. Correspondingly increasing the thickness and lateral area of the bi-metallic strip increases the thermal thrust generated during operation, but the oversized dimensions do not meet the design requirements of the micro device.
In view of the above, the present invention provides a micro breaker capable of effectively preventing instantaneous disconnection due to strong impact and a method of manufacturing the same.
Disclosure of Invention
The invention aims at: aiming at the defects of the prior art, the miniature circuit breaker capable of effectively preventing instant disconnection caused by strong impact and the preparation method thereof are provided.
In order to achieve the above purpose, the invention adopts the following technical scheme:
An impact-resistant miniature circuit breaker comprising the following components:
A housing;
an elastic arm, wherein one end of the elastic arm is provided with a movable contact, and the other end of the elastic arm extends out from one side of the shell;
a fixed arm, one end of which is provided with a fixed contact, and the other end of which extends out from the other side of the shell;
the bimetallic strip assembly comprises a plurality of overlapped bimetallic strips arranged below the elastic arm, and the adjacent bimetallic strips are connected end to form a structure similar to a Z shape;
the lower surface of the elastic arm and the lower surface of the bimetallic strip component are connected with the heat-conducting copper plate;
in the working state, the movable contact and the fixed contact form a concave-convex embedded contact structure.
Specifically, when the invention is in a normal working state, the movable contact at the tail end of the elastic arm is contacted with the fixed contact at the tail end of the fixed arm, and the elastic arm can have a larger bending degree through a common component processing technology, so that a larger vertical pressure is applied to the fixed arm, which is helpful for preventing the separation of the movable contact and the fixed contact in the vertical direction caused by strong impact. In addition, since the movable contact applies a large pressure to the fixed contact at this time, there is a large friction force therebetween, which helps to prevent slippage of the movable contact and the fixed contact in the horizontal direction due to strong impact.
Further, in the miniature circuit breaker provided by the invention, the movable contact is arranged at the tail end of the elastic arm, the convex structure is adopted, the fixed contact is arranged at the tail end of the fixed arm, the concave structure is adopted, when the movable contact is contacted with the fixed contact, the movable contact and the fixed contact form a concave-convex embedded structure, and the structure is beneficial to preventing the movable contact and the fixed contact from sliding in the horizontal direction caused by strong impact.
As an improvement of the impact-resistant miniature circuit breaker, the elastic arm is a bent arm body. When in a normal working state, the used elastic arm has a certain bending deformation degree compared with a free state, stores a certain elastic potential energy, and can apply a certain pressure to the fixed arm. In the invention, the bending deformation degree of the elastic arm can be adjusted through a common processing technology, so that the pressure applied to the fixed arm can be easily adjusted to meet the actual requirement.
As an improvement of the impact-resistant miniature circuit breaker, the movable contact is of a convex structure, and the fixed contact is of a concave structure.
As an improvement of the impact-resistant miniature circuit breaker, the bimetallic strip comprises an active layer positioned below and a passive layer positioned above, wherein the thermal expansion coefficient of the active layer is larger than that of the passive layer.
As an improvement of the impact-resistant miniature circuit breaker, adjacent bimetallic strips are connected by welding or bonding.
As an improvement of the impact-resistant miniature circuit breaker, the lower surface of the elastic arm is connected with the heat-conducting copper plate in a welding or bonding mode; the lower surface of the bimetallic strip component is connected with the heat conducting copper plate in a welding or bonding mode.
As an improvement of the impact-resistant miniature circuit breaker, a plurality of overlapped bimetallic strips are jump-type bimetallic strips with basically consistent sizes, and each bimetallic strip has basically the same jump reversing temperature.
As an improvement of the impact-resistant miniature circuit breaker, the length and the width of the bimetallic strip are smaller than 4mm, the thickness is not larger than 100 mu m, and a plurality of bimetallic strips are tightly stacked when the circuit works normally; when the temperature is abnormal, the bimetallic strips induce each other, and at the same time, the jump is reversed, enough energy is released to jack up the elastic arm in an instant, so that the movable contact is separated from contact with the fixed contact, and the current is cut off.
As an improvement of the impact-resistant miniature circuit breaker, the active layer is made of at least one of Mn-Ni-Cr-Cu alloy, mn-Ni-Cu alloy, ni-Cr alloy, ni-Mn alloy, ni metal and Cu-Zn alloy.
As an improvement of the impact-resistant miniature circuit breaker, the material of the passive layer is Fe-Ni alloy and/or Fe-Ni-Mn alloy.
Specifically, the present invention focuses on using a bimetal composed of a plurality of high-sensitivity snap-through type bimetal pieces, wherein the bimetal piece is formed by connecting a plurality of high-sensitivity snap-through type bimetal pieces, the two bimetal pieces are connected in a Z-shaped manner, an active layer which is an alloy layer with high thermal expansion coefficient is positioned below, and a passive layer which is an alloy layer with low thermal expansion coefficient is positioned above in each bimetal piece. The bimetallic strip is attached by welding or bonding. The lower part of the bimetallic strip component is connected with the heat conducting copper plate in a welding or bonding way. The heat conducting copper plate is connected with the elastic arm at the same time, and the connection mode is welding or bonding. This configuration allows the bi-metallic strip assembly to monitor the temperature of the circuit at any time. When the circuit works normally, current flows from the external port to the fixed arm through the elastic arm and then to the external port, or from the external port to the elastic arm through the fixed arm and then to the external port; when the temperature rises sharply due to abnormal current passing through the circuit, the temperature of the bimetallic strip assembly connected with the elastic arm through the conductive copper wire plate rises along with the temperature, when the set temperature (TS 1) is reached, each bimetallic strip in the bimetallic strip assembly jumps suddenly and reverses, the superposition of thermal thrust provides enough thrust to quickly jack up the elastic arm, and the superposition of displacement travel can ensure that the elastic arm is jacked to a proper height, so that the current is cut off quickly; when the temperature is reduced to the set temperature (TS 2), each bimetallic strip in the bimetallic strip assembly is in jump reset, the elastic arm is overlapped on the fixed arm again under the action of elastic force, the movable contact is contacted with the fixed contact again, and the circuit resumes work. In addition, the bimetallic strip assembly is also sensitive to the ambient temperature, when the ambient temperature suddenly rises, the temperature of the assembly also rises, and when the set temperature (TS 1) is reached, the same process as described above occurs, so that the circuit is cut off, and the circuit is protected; when the temperature drops to the set temperature (TS 2), the same process as described above occurs and the circuit resumes operation.
The bimetallic strip assembly is composed of a plurality of jump-type bimetallic strips with the same size, in actual processing, through a proper processing technology, the dimension error can be ensured to be in a reasonable range, namely the length error and the width error are +/-0.05 mm, so that each bimetallic strip has basically the same jump reversing temperature. When these bimetallic strips are connected end to form a bimetallic strip assembly, the temperature of each bimetallic strip in the bimetallic strip assembly can be kept substantially uniform all the time due to their good thermal conductivity and small gaps (< 30 μm) therebetween. When the ambient temperature rises, the temperature of each bimetallic strip in the bimetallic strip assembly rises along with the rise of the ambient temperature, the internal energy accumulated in each bimetallic strip continuously increases, and when the temperature reaches a set temperature (TS 1), the bimetallic strip firstly goes through a high-energy critical state and then jumps and reverses suddenly, the internal energy is converted into mechanical energy, and thermal thrust and displacement travel are generated.
Another advantage of the present invention is that the number of bi-metallic strips can be flexibly increased or decreased to meet practical needs. The invention also considers the size requirement of the micro device, the length and the width of each bimetallic strip in the bimetallic strip assembly are smaller than 4mm, the thickness is not larger than 100 mu m, and when the circuit works normally, the bimetallic strips in the bimetallic strip assembly are tightly stacked, have small gaps and occupy small space as a whole. For example, a bimetal assembly consisting of 3 pieces of bimetal having an area of 3.00mm by 3.20mm and a thickness of 60 μm each has a thickness of less than 250 μm and occupies a volume of less than 3.00mm by 3.20mm by 0.25mm, which meets the size requirements of the micro device.
In summary, the invention utilizes the reasonable design processing of the elastic arm to improve the contact pressure between the movable contact and the fixed contact, and simultaneously combines the concave-convex embedded structure formed when the contacts are contacted, thereby effectively preventing the separation of the movable contact and the fixed contact in the vertical direction and the horizontal direction caused by strong impact, ensuring good contact between the contacts when the device normally works, and effectively preventing circuit interruption caused by strong impact. Further, the invention provides a bimetal assembly composed of a plurality of bimetal sheets aiming at the structure, and the design realizes the superposition effect of thermal thrust and displacement stroke generated by the plurality of bimetal sheets during the jump reverse, thereby providing enough thermal thrust and displacement stroke to quickly push the elastic arm to a proper position and effectively protecting a circuit. When the temperature is reduced to the set temperature, the bimetallic strip component is reversely reset, and the circuit is restored to normal operation. Another advantage of the present invention is that the number of the bimetal strips can be flexibly increased or decreased according to the elastic force of the elastic arm, thereby meeting different practical requirements. In addition, the invention overcomes the defect that the traditional jump type bimetal needs to increase the size thereof in order to obtain larger thermal thrust and displacement stroke, has small occupied space of the assembly and meets the size requirement of the micro device.
Compared with the prior art, the invention has at least the following advantages:
Firstly, the invention utilizes the reasonable design and processing of the elastic arm to improve the contact pressure between the movable contact and the fixed contact, and simultaneously combines the concave-convex embedded structure formed when the contacts are contacted, thereby effectively preventing the separation of the movable contact and the fixed contact in the vertical direction and the horizontal direction caused by strong impact, ensuring good contact between the contacts when the device works normally, and effectively preventing the circuit from being cut off suddenly caused by strong external force impact.
Secondly, the invention creatively provides a bimetallic strip component with a Z-shaped structure, which is not only a new structure, but also has the key that the structure enables each bimetallic strip to induce each other and act simultaneously, enough energy is released in a moment, superposition of thermal thrust and displacement stroke is realized, and the number of the bimetallic strips can be increased or reduced according to actual requirements. Moreover, the structure occupies small space and meets the size requirement of the micro device.
Drawings
Fig. 1 is a schematic structural diagram and a corresponding circuit diagram of the miniature circuit breaker provided by the invention in a normal working state and an off state.
Fig. 2 is a schematic diagram of the reversing front and rear structures of the bimetal assembly provided by the invention.
Fig. 3 is a schematic diagram of a process for inducing inversion of an adjacent upper bimetal when the lower bimetal is inverted.
Fig. 4 is a schematic diagram of a process of reversing an adjacent lower bimetal when the upper bimetal is reversed.
Fig. 5 is a schematic diagram of a process of inducing inversion of adjacent upper and lower bimetal sheets when the bimetal sheet positioned in the middle is inverted.
Fig. 6 is a schematic structural diagram of the miniature circuit breaker of embodiment 1 of the present invention in a normal operating state and an open state.
Fig. 7 is a schematic structural diagram of the miniature circuit breaker of embodiment 2 of the present invention in a normal operating state and an open state.
Fig. 8 is a schematic structural view of the miniature circuit breaker of comparative example 1 of the present invention in a normal operating state and an opened state.
Fig. 9 is a schematic structural view of the miniature circuit breaker of comparative example 2 of the present invention in a normal operating state and an opened state.
Reference numerals illustrate: 1: an elastic arm; 2: a movable contact; 3: a fixed arm; 4: fixing the contact; 5: a bi-metallic strip assembly; 6: a thermally conductive copper plate; 7: a housing; 8: welding points; 9: welding points; 10: welding points; 11: welding points; 12: welding points; t1: an external port; t2: an external port; 1-1: an elastic arm; 2-1: a movable contact; 3-1: a fixed arm; 4-1: fixing the contact; 5-1: a bi-metallic strip assembly; 6-1: a thermally conductive copper plate; 7-1: a housing; 8-1: welding points; 9-1: welding points; 10-1: welding points; 11-1: welding points; 1-2: an elastic arm; 2-2: a movable contact; 3-2: a fixed arm; 4-2: fixing the contact; 5-2: a bi-metallic strip assembly; 6-2: a thermally conductive copper plate; 7-2: a housing; 8-2: welding points; 9-2: welding points; 10-2: welding points; 11-2: welding points; 12-2: welding points; 13-2: welding points; 1-3: an elastic arm; 2-3: a movable contact; 3-3: a fixed arm; 4-3: fixing the contact; 5-3: a bi-metallic strip assembly; 6-3: a thermally conductive copper plate; 7-3: a housing; 8-3: welding points; 9-3: welding points; 1-4: an elastic arm; 2-4: a movable contact; 3-4: a fixed arm; 4-4: fixing the contact; 5-4: a bi-metallic strip assembly; 6-4: a thermally conductive copper plate; 7-4: a housing; 8-4: welding points; 9-4: welding point
Detailed Description
In order that the above objects, features and advantages of the invention will be readily understood, a more particular description of the invention will be rendered by reference to the appended drawings.
In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, but the present invention may be embodied in other forms and may be practiced by those skilled in the art without departing from the spirit of the invention, and therefore the present invention is not limited to the specific embodiments disclosed below.
For the purpose of making the objects, technical solutions and advantages of the present invention more apparent, embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.
The miniature circuit breaker of the present invention is a miniature circuit breaker for a portable device connected in series with a battery pack or other protected circuit, and as shown in fig. 1, includes: an elastic arm 1; a movable contact 2 disposed at the end of the elastic arm 1; a fixed contact plate 3; a fixed contact 4 disposed at the end of the fixed contact plate 3; a bimetal assembly 5; a thermally conductive copper plate 6, a case 7, and the like. The parts of the elastic arm 1 and the fixed arm 3 exposed out of the shell are connected with an external circuit.
When the miniature circuit breaker is in a normal working state, the movable contact 2 on the tail end of the elastic arm 1 is contacted with the fixed contact 4 on the tail end of the fixed arm 3, and the elastic arm 1 can have a large bending degree through a common part processing technology, so that a large vertical pressure is applied to the fixed arm 3, and the miniature circuit breaker is beneficial to preventing the separation of the movable contact and the fixed contact in the vertical direction caused by strong impact. In addition, since the movable contact applies a large pressure to the fixed contact at this time, there is a large friction force therebetween, which helps to prevent slippage of the movable contact and the fixed contact in the horizontal direction due to strong impact.
Further, in the miniature circuit breaker provided by the invention, the movable contact 2 is arranged at the tail end of the elastic arm 1, the fixed contact 4 is arranged at the tail end of the fixed arm 3, and when the movable contact is contacted with the fixed contact, the movable contact and the fixed contact form a concave-convex embedded structure, and the structure is favorable for preventing the movable contact and the fixed contact from sliding in the horizontal direction caused by strong impact.
When the miniature circuit breaker is in a normal working state, the elastic arm 1 has a certain bending deformation degree compared with a free state, and stores a certain elastic potential energy, so that the miniature circuit breaker can apply a certain pressure to the fixed arm 3. In the present invention, the bending deformation degree of the elastic arm 1 can be adjusted by a common processing technology, so that the pressure applied to the fixed arm 3 can be easily adjusted to meet the actual requirement.
The invention utilizes the reasonable design and processing of the elastic arm 1, improves the contact pressure between the movable contact 2 and the fixed contact 4, and simultaneously combines the concave-convex embedded structure formed when the contacts are contacted, thereby effectively preventing the separation of the movable contact and the fixed contact in the vertical direction and the horizontal direction caused by strong impact, ensuring good contact between the contacts when the device works normally, and effectively preventing the sudden cutting-off of the circuit caused by strong external force impact.
The present invention focuses on the use of a bimetal consisting of a plurality of high sensitivity snap-type bimetal pieces. As shown in fig. 2, the bimetal assembly 5 is formed by connecting a plurality of high-sensitivity jump-type bimetal sheets in a zigzag manner, and in each of the bimetal sheets, an alloy layer having a high thermal expansion coefficient, i.e., an active layer, is located below and an alloy layer having a low thermal expansion coefficient, i.e., a passive layer, is located above. The bimetallic strip is attached by welding or bonding. The lower part of the bimetallic strip component 5 is connected with the heat conducting copper plate 6 in a welding or bonding mode. The heat conducting copper plate 6 is connected with the elastic arm 1 at the same time, and the connection mode is welding or bonding. This configuration allows the bi-metallic strip assembly 5 to monitor the temperature of the circuit at any time. When the circuit works normally, the current flows from the external port T 1 to the fixed arm 3 through the elastic arm 1 and then to the external port T 2, or from the external port T 2 to the elastic arm 1 through the fixed arm 3 and then to the external port T 1; when the temperature rises sharply due to abnormal current passing through the path, the temperature of the bimetallic strip assembly 5 connected with the elastic arm 1 through the conductive copper wire plate 6 rises along with the temperature, when the set temperature (T S1) is reached, the bimetallic strips in the bimetallic strip assembly 5 jump and reverse, the superposition of thermal thrust provides enough thrust to quickly jack up the elastic arm 1, and the superposition of displacement travel can ensure that the elastic arm 1 is jacked to a proper height, so that the current is cut off quickly; when the temperature is reduced to the set temperature (T S2), each bimetallic strip in the bimetallic strip assembly 5 is suddenly reset, the elastic arm 1 is overlapped on the fixed arm 3 again under the action of elastic force, the movable contact 2 is contacted with the fixed contact 4 again, and the circuit resumes operation. In addition, the bimetal assembly 5 is also sensitive to the ambient temperature, when the ambient temperature suddenly rises, the temperature of the assembly also rises, and when the set temperature (T S1) is reached, the same process as described above occurs, so that the circuit is cut off, and the circuit is protected; when the temperature drops to the set temperature (T S2), the same process as described above occurs and the circuit resumes operation.
The bimetal assembly 5 of the present invention is composed of a plurality of snap-through type bimetal pieces having the same size, and in actual processing, a reasonable range of dimensional errors, i.e., a length and width error of + -0.05 mm, can be ensured by a proper processing technique, so that each of the bimetal pieces has substantially the same snap-through inversion temperature. When these bimetallic strips are joined end to form the bimetallic strip assembly 5, the temperature of each bimetallic strip in the bimetallic strip assembly 5 is maintained substantially uniform throughout due to their good thermal conductivity and small gaps (< 30 μm) therebetween. When the ambient temperature increases, the temperature of each bimetallic strip in the bimetallic strip assembly 5 also increases, as the temperature continues to increase, the internal energy accumulated in each bimetallic strip continuously increases, and when the temperature reaches the set temperature (T S1), the bimetallic strip firstly goes through a high-energy critical state and then jumps and reverses suddenly, the internal energy is converted into mechanical energy, and thermal thrust and displacement travel are generated. Unlike a single bi-metallic strip, each bi-metallic strip in bi-metallic strip assembly 5, as coupled to each other, may induce inversion of adjacent bi-metallic strips while reversing, or may be induced by adjacent bi-metallic strips, as shown in fig. 3-5. In fig. 3, the bimetal located below is reversed while causing the edge portion (welding area) of the bimetal located adjacent above to be bent upward in the same direction as the reversing direction of the bimetal, and this induction action triggers the reversing thereof immediately since the bimetal is in a high-energy state at this time; likewise, in fig. 4, the upper bimetal strip is inverted while immediately inducing the inversion of the adjacent lower bimetal strip; in fig. 5, the middle bimetal may induce the adjacent lower and upper bimetal and the bimetal to be rapidly reversed while being reversed. The induced and reversed bi-metal strips further induce the other bi-metal strips to reverse, thus forming a chain reaction, so that all bi-metal strips in the bi-metal strip assembly 5 can complete the reverse motion (the interval is less than 0.01 s) at almost the same time, and the synergistic effect of the bi-metal strips generates the superposition effect of the thermal thrust and the displacement stroke. Likewise, when the temperature drops to the set temperature (T S2), the bimetal assembly 5 can be reversed for an extremely short time.
Another advantage of the present invention is that the number of bi-metallic strips can be flexibly increased or decreased to meet practical needs. The invention also considers the size requirement of the micro device, the length and the width of each bimetallic strip in the bimetallic strip assembly 5 are smaller than 4mm, the thickness is not larger than 100 mu m, and when the circuit works normally, the bimetallic strips in the bimetallic strip assembly 5 are tightly stacked, have small gaps and occupy small space as a whole. For example, a bimetal assembly consisting of 3 pieces of bimetal having an area of 3.00mm by 3.20mm and a thickness of 60 μm each has a thickness of less than 250 μm and occupies a volume of less than 3.00mm by 3.20mm by 0.25mm, which meets the size requirements of the micro device.
Example 1
In fig. 6, the bimetal assembly 5-1 is formed by connecting 3 bimetal sheets;
the transverse area of the bimetallic strip is 2.50-3.00 mm multiplied by 2.80-3.40 mm, preferably 2.70-2.90 mm multiplied by 2.90-3.10 mm, more preferably 2.80mm multiplied by 3.00mm;
the thickness of the bimetallic strip is 40-70 mu m, preferably 50-60 mu m, more preferably 55 mu m;
The thickness ratio of the bimetallic strip active layer to the passive layer is 2:1-1:2, preferably 1.5:1-1:1.5, and more preferably 1.2:1;
The connection mode between the bimetallic strips is welding or bonding, preferably welding, more preferably spot welding;
The metal or alloy used in the bimetallic strip active layer is one of Mn-Ni-Cr-Cu alloy, mn-Ni-Cu alloy, ni-Cr alloy, ni-Mn alloy, ni metal, cu-Zn alloy and the like, preferably Mn-Ni-Cr-Cu alloy, and the chemical components are as follows:
Mn：66.60～73.80％
Ni：9.50～11.00％
Cr：0～3.20％
Cu：16.7～19.20
the alloy used for the passive layer of the bimetallic strip is one of Fe-Ni alloy, fe-Ni-Mn alloy and the like, preferably Fe-Ni-Mn alloy, and the chemical components are as follows:
Fe：61.80～66.2％
Ni：33.80～37.20％
Mn：0～1.00％
In FIG. 6, the alloy used for the elastic arm 1-1 is one of Cu-Ni-Si-Mg-based alloy, cu-Zr-based alloy, and the like, preferably a Cu-Ni-Si-Mg alloy, the chemical composition of which is as follows:
Cu：94.08～97.65％
Ni：2.10～4.30％
Si：0.20～1.30％
Mg：0.05～0.32％
in FIG. 6, the alloy used for the fixed arm 3-1 is one of a Cu-Zr alloy, a Cu-Ni-Si-Mg alloy, and the like, preferably a Cu-Zr alloy, and has the following chemical composition:
Cu：99.50～99.95％
Zr：0.05～0.50％
In fig. 6, the alloy used for the heat conductive copper plate 6-1 is one of a cu—zr-based alloy, a cu—ni—si—mg-based alloy, and the like, preferably a cu—zr-based alloy, and has the following chemical composition:
Cu：99.50～99.95％
Zr：0.05～0.50％
The miniature circuit breaker in this embodiment has an operating temperature of 75±2 ℃ and a reset temperature of 40 ℃.
Example 2
In fig. 7, the bimetal assembly 5-2 is formed by connecting 5 bimetal sheets; other conditions were the same as in example 1.
The miniature circuit breaker in this embodiment has an operating temperature of 75±2 ℃ and a reset temperature of 40 ℃.
Comparative example 1
In fig. 8, the bimetal assembly 5-3 employs a single bimetal sheet having a lateral area of 2.80mm×3.00mm and a thickness of 55 μm; other conditions were the same as in example 1.
In this comparative example, the operating temperature of the bimetal was 75±2℃. After the bimetal operates, the bimetal cannot jack up the elastic arm 1-3 because the elastic arm 1-3 applies a large pressure to the fixed arm 3-3, and the circuit cannot be cut off.
Comparative example 2
In fig. 9, the bimetal assembly 5-4 employs a single bimetal sheet having a lateral area of 3.00mm×3.20mm and a thickness of 60 μm; other conditions were the same as in example 1.
In this comparative example, the operating temperature of the bimetal was 80±2℃. After the bimetallic strip acts, the generated thrust and displacement stroke are smaller, the elastic arm 1-4 cannot be jacked to a proper height, at the moment, the distance between the movable contact 2-4 and the fixed contact 4-4 is smaller, and because the elastic arm 1-4 has certain elasticity, when the movable contact 2-4 and the fixed contact 4-4 shake under the action of external force, the movable contact can be contacted again, so that potential safety hazards are caused.
Variations and modifications to the above would be obvious to persons skilled in the art to which the invention pertains from the foregoing description and teachings. Therefore, the invention is not limited to the specific embodiments disclosed and described above, but some modifications and changes of the invention should be also included in the scope of the claims of the invention. In addition, although specific terms are used in the present specification, these terms are for convenience of description only and do not limit the present invention in any way.
Claims (10)
1. An impact-resistant miniature circuit breaker is characterized by comprising the following components:
A housing;
an elastic arm, wherein one end of the elastic arm is provided with a movable contact, and the other end of the elastic arm extends out from one side of the shell;
a fixed arm, one end of which is provided with a fixed contact, and the other end of which extends out from the other side of the shell;
the bimetallic strip assembly comprises a plurality of overlapped bimetallic strips arranged below the elastic arm, and the adjacent bimetallic strips are connected end to form a structure similar to a Z shape;
the lower surface of the elastic arm and the lower surface of the bimetallic strip component are connected with the heat-conducting copper plate;
in the working state, the movable contact and the fixed contact form a concave-convex embedded contact structure.
2. The impact protection miniature circuit breaker of claim 1, wherein: the elastic arm is a bent arm body.
3. The impact protection miniature circuit breaker of claim 1, wherein: the movable contact is of a convex structure, and the fixed contact is of a concave structure.
4. The impact protection miniature circuit breaker of claim 1, wherein: the bimetallic strip comprises an active layer positioned below and a passive layer positioned above, wherein the thermal expansion coefficient of the active layer is larger than that of the passive layer.
5. The impact protection miniature circuit breaker of claim 1, wherein: adjacent bimetallic strips are connected by welding or bonding.
6. The impact protection miniature circuit breaker of claim 1, wherein: the lower surface of the elastic arm is connected with the heat conduction copper plate in a welding or bonding mode; the lower surface of the bimetallic strip component is connected with the heat conducting copper plate in a welding or bonding mode.
7. The impact protection miniature circuit breaker of claim 1, wherein: the plurality of stacked bimetallic strips are kick-type bimetallic strips with substantially uniform dimensions, and each bimetallic strip has substantially the same kick-reversal temperature.
8. The impact protection miniature circuit breaker of claim 1, wherein: the length and the width of the bimetallic strip are smaller than 4mm, the thickness is not larger than 100 mu m, and when the circuit works normally, a plurality of bimetallic strips are tightly stacked; when the temperature is abnormal, the bimetallic strips induce each other, and at the same time, the jump is reversed, enough energy is released to jack up the elastic arm in an instant, so that the movable contact is separated from contact with the fixed contact, and the current is cut off.
9. The impact resistant miniature circuit breaker of claim 4, wherein: the active layer is made of at least one of Mn-Ni-Cr-Cu alloy, mn-Ni-Cu alloy, ni-Cr alloy, ni-Mn alloy, ni metal and Cu-Zn alloy.
10. The impact resistant miniature circuit breaker of claim 4, wherein: the material of the passive layer is Fe-Ni alloy and/or Fe-Ni-Mn alloy.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311539655.1A CN117612910B (en) | 2023-11-18 | 2023-11-18 | Anti-impact miniature circuit breaker |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311539655.1A CN117612910B (en) | 2023-11-18 | 2023-11-18 | Anti-impact miniature circuit breaker |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN117612910A CN117612910A (en) | 2024-02-27 |
| CN117612910B true CN117612910B (en) | 2024-05-28 |
Family
ID=89952703
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311539655.1A Active CN117612910B (en) | 2023-11-18 | 2023-11-18 | Anti-impact miniature circuit breaker |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117612910B (en) |
Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1169229A (en) * | 1966-09-01 | 1969-10-29 | Texas Instruments Italia Spa | A Thermally Actuated Device Providing a Predetermined Series of Step Displacements of a Drive Element as a Function of Temperature |
| JPH09213182A (en) * | 1996-02-05 | 1997-08-15 | Texas Instr Japan Ltd | Motor protector |
| JP2001023489A (en) * | 1999-07-08 | 2001-01-26 | Masaaki Tone | Protection switch |
| JP2002163965A (en) * | 2000-11-22 | 2002-06-07 | Texas Instr Japan Ltd | Thermal protector |
| CN1461030A (en) * | 2002-05-14 | 2003-12-10 | 阿尔卑斯电气株式会社 | Thermal sensitive switch |
| JP2005071856A (en) * | 2003-08-26 | 2005-03-17 | Alps Electric Co Ltd | Thermally-actuated switch |
| CN2862302Y (en) * | 2005-08-04 | 2007-01-24 | 张拯华 | Manual reset steam switch for electric heating water cup |
| JP2012234630A (en) * | 2011-04-28 | 2012-11-29 | Alps Electric Co Ltd | Sheet with contact spring and switch device using the same |
| CN207993769U (en) * | 2018-03-12 | 2018-10-19 | 珠海市艾格尔电器科技有限公司 | A kind of bimetal strip thermostat structure |
| TWM569064U (en) * | 2018-06-08 | 2018-10-21 | 力興精密科技有限公司 | Structure of multi-layer elastic sheets |
| CN109314013A (en) * | 2016-06-14 | 2019-02-05 | 大冢科技株式会社 | The miniature circuit breaker and its manufacturing method of portable equipment |
| CN219873355U (en) * | 2023-05-18 | 2023-10-20 | 厦门宏发电力电器有限公司 | Reed structure and magnetic latching relay |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7518482B2 (en) * | 2006-10-10 | 2009-04-14 | Dennis William Fleege | Trip unit having a plurality of stacked bimetal elements |
-
2023
- 2023-11-18 CN CN202311539655.1A patent/CN117612910B/en active Active
Patent Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1169229A (en) * | 1966-09-01 | 1969-10-29 | Texas Instruments Italia Spa | A Thermally Actuated Device Providing a Predetermined Series of Step Displacements of a Drive Element as a Function of Temperature |
| JPH09213182A (en) * | 1996-02-05 | 1997-08-15 | Texas Instr Japan Ltd | Motor protector |
| JP2001023489A (en) * | 1999-07-08 | 2001-01-26 | Masaaki Tone | Protection switch |
| JP2002163965A (en) * | 2000-11-22 | 2002-06-07 | Texas Instr Japan Ltd | Thermal protector |
| CN1461030A (en) * | 2002-05-14 | 2003-12-10 | 阿尔卑斯电气株式会社 | Thermal sensitive switch |
| JP2005071856A (en) * | 2003-08-26 | 2005-03-17 | Alps Electric Co Ltd | Thermally-actuated switch |
| CN2862302Y (en) * | 2005-08-04 | 2007-01-24 | 张拯华 | Manual reset steam switch for electric heating water cup |
| JP2012234630A (en) * | 2011-04-28 | 2012-11-29 | Alps Electric Co Ltd | Sheet with contact spring and switch device using the same |
| CN109314013A (en) * | 2016-06-14 | 2019-02-05 | 大冢科技株式会社 | The miniature circuit breaker and its manufacturing method of portable equipment |
| CN207993769U (en) * | 2018-03-12 | 2018-10-19 | 珠海市艾格尔电器科技有限公司 | A kind of bimetal strip thermostat structure |
| TWM569064U (en) * | 2018-06-08 | 2018-10-21 | 力興精密科技有限公司 | Structure of multi-layer elastic sheets |
| CN219873355U (en) * | 2023-05-18 | 2023-10-20 | 厦门宏发电力电器有限公司 | Reed structure and magnetic latching relay |
Also Published As
| Publication number | Publication date |
|---|---|
| CN117612910A (en) | 2024-02-27 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP2000311575A (en) | Fuse and fuse built-in pack battery | |
| EP1876615B1 (en) | Electrical switching apparatus contact assembly and movable contact arm therefor | |
| JP3820055B2 (en) | Thermal protector | |
| TW202109584A (en) | Protection element | |
| JP7433796B2 (en) | protection element | |
| JP6173691B2 (en) | Contact structure | |
| CN117612910B (en) | Anti-impact miniature circuit breaker | |
| CN211654935U (en) | Busbar and battery module | |
| WO2020155649A1 (en) | Surge protector | |
| CN216145603U (en) | Thermal protection type transient voltage suppressor | |
| KR100546424B1 (en) | Thermal protector | |
| KR101266807B1 (en) | Micro chip fuse | |
| JPH10162704A (en) | Thermal fuse | |
| CN106710979A (en) | Switch module internally provided with surge absorbing and circuit breaking structure | |
| CN102270552B (en) | Breaker and method for controlling heat energy in breaker | |
| CN214068677U (en) | Heavy current protector | |
| CN215069856U (en) | Double-metal component of circuit breaker | |
| CN216288275U (en) | SPD backup protector with strong impact resistance | |
| JP3344180B2 (en) | Circuit breaker | |
| CN215267635U (en) | Switch type lightning protection module with remote signaling and tripping functions | |
| TWI680605B (en) | Protective element and secondary battery pack | |
| CN217215945U (en) | Surge protection device | |
| WO2021015154A1 (en) | Protective element and protective circuit | |
| JPS6261231A (en) | Circuit breaker | |
| CN206432222U (en) | A kind of miniature circuit breaker magnetic system and miniature circuit breaker |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |