CN214956620U

CN214956620U - Large-current pressure type manual reset temperature limiter

Info

Publication number: CN214956620U
Application number: CN202120758787.3U
Authority: CN
Inventors: 吴国伟; 刘小敏; 何国炎
Original assignee: Foshan Tongbao Huasheng Heating Controller Co ltd
Current assignee: Foshan Tongbao Huasheng Heating Controller Co ltd
Priority date: 2021-04-14
Filing date: 2021-04-14
Publication date: 2021-11-30
Anticipated expiration: 2031-04-14

Abstract

The utility model provides a heavy current pressure type manual reset temperature limiter, is in the structure of current pressure type manual reset temperature limiter, and it has a slice pure copper overcurrent piece to rivet fixed at movable contact spring both ends, and this overcurrent piece interlude is equipped with 2 ~ 6 ripples and is located movable contact spring corresponding section top, does not contact with it. The large-current pressure type manual reset temperature limiter can pass through 40A rated current and is suitable for overtemperature protection of a household high-power electric heating appliance.

Description

Large-current pressure type manual reset temperature limiter

Technical Field

The utility model relates to a pressure type manual reset temperature limiter technical field, in particular to a heavy current pressure type manual reset temperature limiter for overtemperature protection of a household high-power electric heating appliance.

Background

The pressure type manual reset temperature limiter is widely applied to temperature limiting protection of household electric heating appliances such as electric water heaters, water boilers and the like, and can be used for continuously heating a heating tube by sensing the temperature of the electric heating appliances when a temperature controller fails, and enabling a switch double pole of the temperature limiter to be disconnected when the temperature is too high, so that the heating tube stops working. The switch can be turned on again only by manually pressing the reset lever after the circuit fault is eliminated and the temperature is reduced. The switch component of the pressure type manual reset temperature limiter is connected with the heating tube in series and connected into a mains supply circuit, and when the temperature of a heating source is too high, the circuit can be automatically disconnected, so that the overtemperature protection effect is achieved.

Chinese patent publication No. CN2350796Y discloses a pressure type manual reset temperature limiter. One end of a spring piece 4 is riveted with a moving contact, the other end is riveted on a spring piece riveting pin 6 (namely a terminal) through a rivet, and then the spring piece is fixed on a base 12 through the rivet. The contact is closed at ordinary times; when the temperature of the heating source rises, the capsule 14 acts to make the push rod 10 move upwards to jack the spring piece 4, and further to make the contact break. When the temperature drops, the push rod 10 needs to be pressed to reset the contact.

In the structure, the spring piece 4 is a cantilever beam bending deformation with one fixed end and the other free end, and the main loop current flows through the spring piece 4 through the spring piece riveting pin 6 and then flows through the contact and then flows to the static contact piece 5, so the spring piece 4 needs to have elasticity and conductivity, tin bronze or beryllium bronze materials are usually adopted, but the conductivity of the tin bronze is 13-20% IACS, the conductivity of the beryllium bronze is only 16-25% IACS, the elasticity is lost due to heating when the rated current is overlarge, the temperature limiter fails, even a plastic base is melted or carbonized and burned to cause serious potential safety hazards, if the internal resistance is reduced by increasing the cross-sectional area of the spring piece 4, firstly, the width is limited by space, secondly, the deformation force is sharply increased by increasing the thickness (according to the material mechanics formula, the cantilever beam bending deformation force is in a cubic ratio with the material thickness), if the deformation force is too large, the existing common diaphragm capsule is not enough to push the diaphragm capsule to deform, and if the diaphragm capsule is enlarged, the volume and the cost are increased greatly.

The maximum overload capacity of the pressure type manual reset temperature limiter with the structure on the market is only 25A rated current. With the continuous release of high-power electric heaters, the temperature limiter with the rated current of 25A can not meet the requirements, if the high-power electric heater with the rated current of 40A is forcibly connected into the pressure type manual reset temperature limiter with the rated current of 25A, the temperature rises to over 100 ℃ quickly because of the heating caused by the flowing of large current in normal work, the spring piece loses elasticity, and the moving contact and the static contact can not be conducted quickly. Therefore, a pressure type manual reset temperature limiter with the rated current of 40A needs to be developed.

SUMMERY OF THE UTILITY MODEL

The to-be-solved technical problem of the utility model is to provide a manual reset temperature limiter of heavy current pressure type, it can be applicable to the overtemperature protection to domestic high-power electric heating appliance through 40A rated current.

The utility model provides a technical solution as follows:

a large-current pressure type manual reset temperature limiter comprises a capillary tube, a diaphragm capsule, a base, a cover plate and a push rod, wherein two groups of independent electric contact switch loops which are arranged in parallel are arranged in a cavity formed by the base and the cover plate, each electric contact switch loop consists of a static terminal, a movable contact and a movable terminal, the static terminal is fixedly provided with a static contact at the right end, the movable contact is fixedly provided with a movable contact at the left end, the left end of the static terminal is fixed on the base, the movable contact is in direct contact connection with the static contact, the right end of the movable contact is fixedly connected with the base after being riveted and fixed with the movable terminal, the movable contact of the cantilever beam structure is provided with resilience in the downward direction, the middle part of the push rod is provided with a front shoulder and a rear shoulder which are respectively in contact connection with corresponding parts of the two movable contacts, the bottom end of the push rod is in contact connection with the diaphragm capsule and is provided with an overcurrent sheet made of pure copper sheet, the overcurrent sheet comprises a left side section, an intermediate section and a right side section, wherein the intermediate section of the overcurrent sheet is provided with at least 2 continuous corrugations, the left end part of the left side section of the overcurrent sheet is riveted and fixed with the left end part of the movable contact sheet and the movable contact, the right end part of the right side section of the overcurrent sheet is riveted and fixed with the right end part of the movable contact sheet and the movable terminal, and the intermediate section of the overcurrent sheet is contactless with the opposite section of the movable contact sheet.

The movable contact piece is made of beryllium bronze, and the cross-sectional area of the movable contact piece is as follows: the width is 6 to 9mm, and the thickness is 0.18 to 0.22 mm. The cross-sectional area of the overflowing sheet is as follows: the width is 6 to 9mm, and the thickness is 0.18 to 0.22 mm. The middle section of the overflowing sheet is provided with 2-6 continuous ripples.

Compared with the prior art, the utility model discloses following beneficial effect has:

the utility model discloses a there is a pure copper overcurrent piece at movable contact piece both ends riveting fixed on the structure basis of current pressure type manual reset temperature limiter, should overflow the piece interlude and be equipped with 2 ~ 6 ripples and be located movable contact piece corresponding section top, not rather than the contact, the piece that overflows that just so makes the new increase has good flexibility, can not produce an additional effort rather than the equidirectional of resilience force to the movable contact piece basically, do not change original cubical switchboard mechanism's mechanical properties promptly basically, thereby, pressure type manual reset temperature limiter accessible 25A ~ 40A's rated current has been realized. The volume of the large-current pressure type manual reset current limiter is the same as that of the existing pressure type manual reset temperature limiter with the overload capacity of 25A rated current, and the temperature control precision is also the same.

Drawings

Fig. 1 is a schematic structural view of a large-current pressure type manual reset temperature limiter of the present invention in a contact connection state.

Fig. 2 is a schematic structural diagram of the high-current pressure type manual reset temperature limiter shown in fig. 1 in a contact disconnection state.

Fig. 3 is a schematic sectional view taken along line a-a of fig. 1.

The reference numbers in the figures denote: 1. capillary tube, 2, diaphragm capsule, 2-1, diaphragm capsule sheet, 3, base, 4, 1 st movable terminal, 5, cover plate, 6, 1 st movable contact sheet, 6-1, 1 st movable contact sheet left end, 6-2, 1 st movable contact sheet right end, 7, 1 st overcurrent sheet, 7-1, 1 st overcurrent sheet left side section, 7-2, 1 st overcurrent sheet right side section, 7-3, 1 st overcurrent sheet middle section, 8 push rod, 8-1 push rod front shoulder, 8-2 push rod rear shoulder, 9, 1 st movable contact, 10, 1 st stationary terminal, 11, 1 st stationary contact, 16, 2 nd movable contact sheet, 17, 2 nd overcurrent sheet, 17-3, 2 nd overcurrent sheet middle section.

Detailed Description

The present invention is further illustrated by the following examples.

Referring to fig. 1, 2 and 3, a large current pressure type manual reset temperature limiter comprises a capillary tube 1, a diaphragm capsule 2, a base 3, a cover plate 5 and a push rod 8, wherein two groups of independent and parallel electric contact switch loops are arranged in a cavity formed by the base 3 and the cover plate 5, each electric contact switch loop consists of a fixed terminal with a fixed contact fixedly arranged at the right end part, a movable contact and a movable terminal with a movable contact fixedly arranged at the left end part, the left end part of the fixed terminal is fixed on the base 3, the movable contact is in contact connection with the fixed contact, the right end part of the movable contact is fixedly connected with the base 3 after being riveted and fixed with the movable terminal, the movable contact of the cantilever beam structure is provided with resilience in advance in the downward direction, the middle part of the push rod 8 is provided with a front shoulder 8-1 and a rear shoulder 8-2 which are respectively in contact connection with corresponding parts of the two movable contacts, the bottom end part of the push rod 8 is in contact connection with the diaphragm capsule sheet 2-1, an overcurrent sheet made of pure copper sheets is arranged, the overcurrent sheet consists of a left side section, a middle section and a right side section, the middle section of the overcurrent sheet is provided with at least 2 continuous ripples, the left end part of the left side section of the overcurrent sheet is riveted and fixed with the left end part of the movable contact sheet and the movable contact, the right end part of the right side section of the overcurrent sheet is riveted and fixed with the right end part of the movable contact sheet and the movable terminal, and the middle section of the overcurrent sheet is not in contact with the opposite section of the movable contact sheet.

The structure and the working process of the pressure type manual reset temperature limiter with the overload capacity of 40A rated current are explained in detail below. The temperature limiter mainly comprises a capillary tube 1, a diaphragm capsule 2, a base 3, a 1 st movable terminal 4, a 2 nd movable terminal, a cover plate 5, a 1 st movable contact 6, a 2 nd movable contact 16, a 1 st overcurrent sheet 7, a 2 nd overcurrent sheet 17, a push rod 8, a push rod front shoulder 8-1, a push rod rear shoulder 8-2, a 1 st movable contact 9, a 2 nd movable contact, a 1 st fixed terminal 10, a 2 nd fixed terminal, a 1 st fixed contact 11 and a 2 nd fixed contact, wherein a left side section 7-1 of the 1 st overcurrent sheet 7 and a left end part 6-1 of the 1 st movable contact are riveted on the 1 st movable contact 9 at the same time, a right side section 7-2 of the 1 st overcurrent sheet 7 and a right end part 6-2 of the 1 st movable contact are fixedly connected on the 1 st movable terminal 4 at the same time, and an intermediate section 7-3 of the 1 st overcurrent sheet 7 is provided with 5 corrugations and is not in contact with a relative section of the 1 st movable contact with the 1 st movable contact sheet 6; similarly, the left side section of the 2 nd overcurrent piece 17 and the left end part of the 2 nd movable contact piece are riveted on the 2 nd movable contact at the same time, the right side section of the 2 nd overcurrent piece 17 and the right end part of the 2 nd movable contact piece are fixedly connected on the 2 nd movable terminal at the same time, and the middle section 17-3 of the 2 nd overcurrent piece 17 is also provided with 5 ripples and is not contacted with the opposite section of the 2 nd movable contact piece 16; the capillary tube 1 is connected with the diaphragm capsule 2 in a welding way, and working medium liquid is filled and sealed. In this example, the 1 st static terminal 10 is connected to the mains phase line through its internal screw joint, the 2 nd static terminal is connected to the mains zero line through its internal screw joint, and the 1 st moving terminal 4 and the 2 nd moving terminal are connected to the load of the electric heating appliance through their internal screw joints, respectively. When the temperature of the capillary tube 1 is sensed to be high enough, the working medium liquid is locally gasified to generate pressure, the bellows sheet 2-1 of the bellows 2 is pushed to turn over, the push rod 8 is pushed to move upwards, the 1 st movable contact 6 and the 2 nd movable contact 16 are respectively pushed to bend upwards and deform through the front shoulder 8-1 and the rear shoulder 8-2 of the push rod, the 1 st overflowing sheet 7 and the 2 nd overflowing sheet 17 deform along with the push rod, so that the 1 st movable contact 9 and the 2 nd movable contact are respectively disconnected with the 1 st fixed contact 11 and the 2 nd fixed contact, namely, the phase line and the zero line of the power supply main circuit are simultaneously disconnected, and the temperature limiting protection effect is achieved. When the temperature is reduced, the push rod 8 is manually pressed to reset, the diaphragm capsule sheet 2-1 of the diaphragm capsule 2 is pressed back to the initial state, meanwhile, the push rod 8 does not jack the 1 st movable contact 6 and the 2 nd movable contact any more, and the 1 st movable contact 9 and the 2 nd movable contact are respectively driven by the resilience force of the 1 st movable contact 6 and the 2 nd movable contact to return to the state of being communicated with the 1 st fixed contact 11 and the 2 nd fixed contact by virtue of the 1 st movable contact 7 and the 2 nd overcurrent 17.

When the push rod 8 jacks up the 1 st movable contact spring 6, the 1 st movable contact spring 6 is in cantilever bending deformation, the outer side (the side far away from the center of the curvature radius of the bending deformation) is in tensile stress, the inner side (the side close to the center of the curvature radius of the bending deformation) is in compressive stress, the 1 st overcurrent sheet 7 is arranged on the 1 st movable contact spring 6, is in bending deformation and is subjected to transverse shrinkage deformation force, and as the 5 corrugated structures at the middle section 7-3 of the 1 st overcurrent sheet 7 have sufficient flexibility, the corrugations are easy to deform under transverse compression, only the wave crests are slightly higher, the wave distances are slightly shorter, and the transverse deformation rigidity is far smaller than the elastic modulus of the material, so that basically no additional reactive force is generated; the stress conditions of the 2 nd movable contact piece 16 and the 2 nd overcurrent piece 17 of the other group of electrical contact switch circuit are the same; the push rod 8 can act only by overcoming the resilience force of the movable contact piece, and the capsule 2 can still use the common capsule before without being enlarged; when the push rod 8 is reset, the resilience force of the movable contact piece can drive the corresponding overcurrent piece to return to the initial position.

In this embodiment, two movable terminals, movable contacts, overcurrent pieces, movable contacts, static terminals and static contacts with the same shape and structure are adopted, the push rod adopts a double-shoulder structure to push two switches simultaneously, and phase lines and zero lines of a power supply main circuit are disconnected simultaneously, so that the purpose of safety is achieved.

In this embodiment, the 1 st and 2 nd movable contact pieces are made of beryllium bronze sheet with thickness of 0.2mm and width of 8mm, and the 1 st and 2 nd overcurrent pieces are made of pure copper sheet with same width as the 1 st and 2 nd movable contact pieces, because the resistivity of pure copper is as small as 1.72 × 10^-8Omega m (the conductivity is 100% IACS), is about 1/4 ~ 1/5 of beryllium bronze only, so most of current flows through the overcurrent piece, through the actual measurement, the temperature rise is < 25K when passing 40A current, fully satisfies the requirement of flowing 40A rated current, can not bring any adverse effect to the resilience of movable contact piece and plastic base 3.

Claims

1. A large-current pressure type manual reset temperature limiter comprises a capillary tube (1), a diaphragm capsule (2), a base (3), a cover plate (5) and a push rod (8), wherein two groups of independent electric contact switch loops which are arranged in parallel are arranged in a cavity formed by the base (3) and the cover plate (5), each electric contact switch loop consists of a fixed terminal, a movable contact and a movable terminal, the fixed terminal is fixedly provided with a fixed contact at the right end, the movable contact is fixedly arranged at the left end, the movable contact is in contact connection with the fixed contact in a right-facing way, the movable contact is fixedly connected with the base (3) after being riveted and fixed with the movable terminal at the right end, the movable contact is pre-provided with resilience in a downward direction, a front shoulder (8-1) and a rear shoulder (8-2) are arranged in the middle of the push rod (8) and are respectively in contact connection with corresponding parts of the two movable contacts, the bottom end part of the push rod (8) is in contact connection with the membrane box sheet (2-1), and the device is characterized in that: the overcurrent piece is provided with a pure copper sheet, the overcurrent piece consists of a left side section, a middle section and a right side section, the middle section of the overcurrent piece is provided with at least 2 continuous corrugations, the left end part of the left side section of the overcurrent piece is riveted and fixed with the left end part of the movable contact piece and the movable contact, the right end part of the right side section of the overcurrent piece is riveted and fixed with the right end part of the movable contact piece and the movable terminal, and the middle section of the overcurrent piece is not in contact with the opposite section of the movable contact piece.

2. The high-current pressure type manual reset temperature limiter according to claim 1, wherein the movable contact piece is made of beryllium bronze, and the cross-sectional area of the movable contact piece is as follows: the width is 6 to 9mm, and the thickness is 0.18 to 0.22 mm.

3. The high-current pressure type manual reset temperature limiter according to claim 1, wherein the cross-sectional area of the overcurrent piece is as follows: the width is 6 to 9mm, and the thickness is 0.18 to 0.22 mm.

4. A large-current pressure type manual reset temperature limiter according to claim 1, wherein 2-6 continuous ripples are arranged at the middle section of the overcurrent piece.