Electric air door defrosting device for air-cooled refrigerator

Abstract

A defrosting device for an electric damper of an air-cooled refrigerator belongs to the technical field of air-cooled refrigerators. A defrosting module is provided on the damper frame of the electric damper. The hard conductive plastic strip of the defrosting module and its first and second connection ports are positioned and fixed in a cavity formed by the four bosses, the first boss and the air outlet surround through four bosses with umbrella-shaped barbs and a first boss and a baffle plate. At the same time, a preparation method of the defrosting device and an assembly method on the damper frame are also disclosed. The defrosting device for an electric damper of an air-cooled refrigerator has a simple structure, high production efficiency, and is easy to realize production automation; the defrosting module can be quickly, reliably and efficiently assembled on the damper frame.

Description

Technical Field

[0001] The invention relates to the technical field of air-cooled refrigerators, and in particular to an electric air door defrosting device for air-cooled refrigerators. Background Art

[0002] Air-cooled refrigerators are widely used due to their efficient cooling effect and stable temperature control. However, in low-temperature environments, the contact between the damper door plate and the air outlet surround of air-cooled refrigerators is prone to frost, which seriously affects the damper's control of the air supply volume and makes the refrigerator unable to work normally.

[0003] The Chinese Patent Gazette has published a patent with the announcement number CN203443223U and the name "A refrigerator electric damper with a heating device", which uses a heating wire to defrost the electric damper. Because the heating wire used is a very fine metal wire spirally wound on a plastic core and covered with a silicone rubber insulating sheath, it is a flexible component. In the actual production process, the heating wire and the installation slot are interference fits, and the heating wire needs to be pressed into the installation slot with force, and then fixed with glue. This assembly structure makes it difficult to accurately press all the heating wires into the installation slot, and the installation efficiency is low, it is difficult to achieve production automation, and the production cost is also high. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide an electric damper defrosting device for an air-cooled refrigerator. Since its defrost module is formed by injection molding using a hard conductive plastic material as a heating substrate, and is positioned and fixed in the outer cavity of the air outlet surround by a plurality of protruding columns and blocking plates, it has a simple structure and high production efficiency. The defrost module can be easily, quickly and efficiently assembled on the damper frame, and is easy to realize production automation.

[0005] The technical solution proposed in the present invention is as follows: an electric damper defrosting device for an air-cooled refrigerator comprises a damper frame, a rectangular air outlet is provided in the middle and lower center of the damper frame, the air outlet is provided with a surrounding edge composed of two opposite long surrounding edges and two opposite short surrounding edges, two vertical cylindrical bosses are respectively provided on the damper frame beside the outer sides of the upper and lower long surrounding edges, a blocking plate and a vertical cylindrical first boss and a first positioning pin and a second positioning pin are respectively provided on the damper frame beside the outer side of the short surrounding edge at the upper end of the air outlet; a defrost module is also provided, the hard conductive plastic strip of the defrost module and the first connection port and the second connection port thereof are positioned and fixed in a cavity formed by the four bosses, the first boss and the air outlet surrounding edge through four bosses with umbrella-shaped hooks, the first boss and the blocking plate.

[0006] The defrost module consists of a rectangular hard conductive plastic strip, a first connection port and a second connection port connected to the ends thereof, and a first metal terminal and a second metal terminal respectively embedded in the first connection port and the second connection port. The first connection port is provided with a first positioning hole, and the second connection port is provided with a second positioning hole. The defrost module is coated with a layer of insulating paint except for the first metal terminal and the second metal terminal.

[0007] The middle section of the hard conductive plastic strip located between the two protruding columns on the outer side of the long peripheral edge is curved, the hard conductive plastic strip is in the shape of a flat cube, the first connection port and the second connection port are in the shape of a flat plate, and the cross-sectional area of ​​the first connection port and the second connection port is larger than the cross-sectional area of ​​the hard conductive plastic strip.

[0008] The hard conductive plastic strip, the first connection port, the second connection port, the first metal terminal and the second metal terminal are integrally pressed and molded into a defrosting module using PA carbon fiber composite conductive material.

[0009] A method for preparing and assembling an electric air door defrosting device for an air-cooled refrigerator, the method steps are as follows: ① When the damper frame is injection molded, four bosses, a first boss, a first positioning pin and a second positioning pin are added to the outer side of the tuyere surround; ② Fill the inner cavity of the mold with PA carbon fiber composite conductive material and insert the first metal terminal and the second metal terminal at the corresponding positions, and hot-press them into a defrosting module through an injection molding machine; ③ Coat the hard conductive plastic strip, the first connection port and the second connection port of the defrost module with a layer of insulating paint with a thickness of 0.1 to 0.3 mm and dry them; ④ Place the painted defrost module in the cavity outside the air outlet surround, and position it through the first positioning pin, the first positioning hole, the second positioning pin, and the second positioning hole; ⑤ The upper parts of the four bosses are hot-pressed into umbrella-shaped hooks by a hot press, and the bottom plane of the umbrella-shaped hooks is positioned, contacted and connected with the upper plane of the corresponding hard heat-conductive plastic strip; the upper part of the first boss is hot-pressed into an umbrella-shaped hook by a hot press, and the bottom plane of the umbrella-shaped hook is fixedly connected with the upper plane of the corresponding first connection port and the upper plane of the second connection port; it becomes an electric damper of an air-cooled refrigerator with a defrosting device.

[0010] Compared with the prior art, the present invention has the following significant effects: The present invention adopts PA carbon fiber composite conductive material as the heating substrate of the hard conductive plastic strip, and makes the defrost module through injection molding, which can conveniently and efficiently obtain the hard conductive plastic strip matching the shape of the air door and air outlet surround, and the two metal terminals can also be simultaneously injection molded into the defrost module, saving the riveting process; the defrost module is a hard plastic part, and by arranging four cylindrical bosses and a first boss, a blocking plate and two positioning pins on the air door frame outside the air outlet surround, the defrost module can be quickly and accurately placed on the air door frame with a preset position, and then, the upper part of the first boss is hot-pressed into an umbrella-shaped hook through a hot pressing device and fixedly connected with the first and second connecting ports, and the upper parts of the four bosses are hot-pressed into umbrella-shaped hooks, which are respectively positioned and contacted with the corresponding hard conductive plastic strips. The operation is simple, fast, reliable and efficient, the production efficiency is high, the production cost is low, and it is easy to realize production automation. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 The invention discloses a structural schematic diagram of an electric air door defrosting device for an air-cooled refrigerator.

[0012] Figure 2 yes Figure 1 MM cross-sectional diagram.

[0013] Figure 3 yes Figure 1 FF cross-sectional diagram.

[0014] Figure 4 yes Figure 1 The structural schematic diagram of the defrost module is shown. DETAILED DESCRIPTION

[0015] The present invention is further described in detail by the following examples.

[0016] See also Figure 1 to Figure 4As shown, an electric air door defrosting device for an air-cooled refrigerator comprises an air door frame 1, wherein a rectangular air outlet 1-3 is provided in the middle and lower center of the air door frame 1, wherein the air outlet 1-3 is provided with a surrounding edge 1-4 consisting of two opposite long surrounding edges 1-4-1 and two opposite short surrounding edges 1-4-2, wherein two vertical cylindrical protrusions 1-2 are respectively provided on the air door frame 1 beside the outer sides of the upper and lower parts of the long surrounding edges 1-4-1, and a blocking plate 1-6 is provided on the air door frame 1 beside the outer sides of the short surrounding edges 1-4-2 at the upper end of the air outlet 1-3 and a vertical cylindrical first boss 1-10 and a first positioning pin 1-8 and a second positioning pin 1-8 respectively located on both sides of the baffle plate 1-6; a defrost module 2 is also provided, and the hard conductive plastic strip 2-1 of the defrost module 2 and its first connection port 2-1-1 and the second connection port 2-1-2 are positioned and fixed in the cavity formed by the four bosses 1-2, the first boss 1-10 and the air outlet surround 1-4 through the four bosses 1-2 with umbrella-shaped barbs and the first boss 1-10 and the baffle plate 1-6.

[0017] The defrost module 2 consists of a rectangular hard conductive plastic strip 2-1, a first connection port 2-1-1 connected to its ends, a second connection port 2-1-2, and a first metal terminal 2-2-1 and a second metal terminal 2-2-2 respectively connected to the first connection port 2-1-1 and the second connection port 2-1-2. The first connection port 2-1-1 is provided with a first positioning hole 2-1-1-1, and the second connection port 2-1-2 is provided with a second positioning hole 2-1-2-1. The defrost module 2 is coated with a layer of insulating paint except for the first metal terminal 2-2-1 and the second metal terminal 2-2-2.

[0018] The middle section of the hard conductive plastic strip 2-1 located between the two convex columns 1-2 on the outer side of the long surrounding edge 1-4-1 is curved, the hard conductive plastic strip 2-1 is a flat cube, the first connection port 2-1-1 and the second connection port 2-1-2 are flat plates, and the cross-sectional area of ​​the first connection port 2-1-1 and the second connection port 2-1-2 is larger than the cross-sectional area of ​​the hard conductive plastic strip 2-1.

[0019] The hard conductive plastic strip 2-1, the first connection port 2-1-1, the second connection port 2-1-2, the first metal terminal 2-2-1 and the second metal terminal 2-2-2 are integrally pressed into the defrost module 2 using PA carbon fiber composite conductive material.

[0020] A method for preparing and assembling an electric air door defrosting device for an air-cooled refrigerator, the method steps are as follows: ① When the damper frame 1 is injection molded, four bosses 1-2, a first boss 1-10, a first positioning pin 1-8 and a second positioning pin 1-9 are added to the outer side of the tuyere surround 1-4; ② Fill the inner cavity of the mold with PA carbon fiber composite conductive material and insert the first metal terminal 2-2-1 and the second metal terminal 2-2-2 at the corresponding positions, and hot-press them into a defrosting module 2 through an injection molding machine; ③ Coat the hard conductive plastic strip 2-1, the first connection port 2-1-1, and the second connection port 2-1-2 of the defrost module 2 with a layer of insulating paint with a thickness of 0.1 to 0.3 mm, and dry them; ④ Place the painted defrost module 2 in the outer cavity of the air outlet surround 1-4, and position it through the first positioning pin 1-8, the first positioning hole 2-1-1-1 and the second positioning pin 1-9 and the second positioning hole 2-1-2-1; ⑤ The upper parts of the four bosses 1-2 are hot-pressed into umbrella-shaped barbs 1-2-1 by a hot press, and the bottom plane of the umbrella-shaped barbs 1-2-1 is positioned, contacted and connected with the upper plane of the corresponding hard heat-conductive plastic strip 2-1; the upper part of the first boss 1-10 is hot-pressed into an umbrella-shaped barb 1-2-1 by a hot press, and the bottom plane of the umbrella-shaped barb 1-2-1 is fixedly connected with the upper plane of the corresponding first connection port 2-1-1 and the upper plane of the second connection port 2-1-2; it becomes an electric damper of an air-cooled refrigerator with a defrosting device.

[0021] The hard conductive plastic strip 2-1 is in the shape of a flat line, with a rectangular cross section, a length of D and a height of C; it is arranged in partial straight or curved segments along the outer side of the surrounding edge 1-4, covering the cavity beside the outer side of the surrounding edge 1-4 as much as possible, so that the defrosting effect at the air outlet 1-3 reaches an ideal state.

[0022] A blocking plate 1-6 is provided on the damper frame 1, which can ensure that a certain electrical gap is maintained between the first connection port 2-1-1 and the second connection port 2-1-2 at both ends of the hard conductive plastic strip 2-1 after installation.

[0023] A convex column 1-2 is respectively provided on the outer side of the front half and the rear half of each long surrounding edge 1-4-1; the shortest distance B between each convex column 1-2 and the corresponding long surrounding edge 1-4-1 is (1.1-1.2)D; the shortest distance A between the bottom outer circle of the umbrella-shaped barb 1-2-1 of the convex column 1-2 and the corresponding long surrounding edge 1-4-1 is (0.7-0.8)D.

[0024] In this embodiment, the number of the protruding columns 1-2 is 4, and they are all straight cylindrical at the beginning. After the defrosting module 2 is installed into the inner cavity of the air door frame 1, the upper part of the protruding column 1-2 is hot-pressed into an umbrella-shaped barb 1-2-1 by a hot press.

[0025] The cross-sectional length D of the hard conductive plastic strip 2-1 of this embodiment is 2.5mm, and the height C is 2mm. The working voltage is DC12V, and the electric power of the hard conductive plastic strip 2-1 is 1W. When the defrost module 2 is not working, when the temperature of the hard conductive plastic strip 2-1 drops from 25°C to -40°C, the length D of its cross section shrinks by about 0.03mm; when the defrost module 2 is working, the maximum temperature of the hard conductive plastic strip 2-1 can reach 70°C, and when it rises from 25°C to 70°C, the length D of its cross section expands by 0.05mm. Therefore, in order to prevent the defrost module 2 from escaping from the cavity, the shortest distance A≤0.8D from the bottom outer circle of the umbrella-shaped barb 1-2-1 of the convex column 1-2 to the corresponding long surrounding edge 1-4-1.

[0026] The first metal terminal 2-2-1, the second metal terminal 2-2-2, the hard conductive plastic strip 2-1, the first connection port 2-1-1, and the second connection port 2-1-2 of the defrost module 2 in this embodiment are assembled by insert injection molding. The first metal terminal 2-2-1 and the second metal terminal 2-2-2 are both L-shaped, and their bottoms are respectively embedded in the first connection port 2-1-1 and the second connection port 2-1-2. The embedding depth h is greater than 0.8mm, and the thickness w of the rubber coating is greater than 1mm to ensure that the embedding is firm and reliable. Based on the above purposes, the cross-sectional area of ​​the first connection port 2-1-1 and the second connection port 2-1-2 of the defrost module 2 is larger than the cross-sectional area of ​​the hard conductive plastic strip 2-1. In this embodiment, the cross-sectional length of the first connection port 2-1-1 and the second connection port 2-1-2 is 6mm, and the height is 2mm, that is, the cross-sectional area is 12mm 2 The effective length of the first and second connection ports 2-1-1 and 2-1-2 is 12 mm. The PA carbon fiber composite conductive material used in the hard conductive plastic strip 2-1 and the first and second connection ports 2-1-1 has a resistivity of 3.6×10 -3 Ω·m, calculated using the formula R=ρL / S (where L represents the effective length of the first and second connection ports 2-1-1 and 2-1-2, and S represents the cross-sectional area of ​​the first and second connection ports 2-1-1 and 2-1-2), the resistance corresponding to the effective length of the first and second connection ports 2-1-1 and 2-1-2 is 3.6Ω. The overall resistance of the defrost module 2 is 144Ω, so the resistance of the first connection port 2-1-1 and the second connection port 2-1-2 only accounts for 2.5% of the overall resistance, which has little effect on the heating and defrosting effect near the air outlet surround 1-4, and can be ignored.

[0027] In this embodiment, the defrost module 2 is arranged in the outer cavity of the long side 1-4-1, and the middle hard conductive plastic strip 2-1 between the two convex pillars 1-2 on the same side adopts a curved shape. The working voltage used by the electric damper of the defrost module 2 is DC12V, and the power of the defrost module 2 is 1W. Because the defrost module 2 is pure resistance heating, its resistance R is 144Ω. The resistivity ρ of the PA carbon fiber composite conductive plastic used in this embodiment is 3.6X10 -3 Ω·m, the cross-sectional length of the hard conductive plastic strip 2-1 is 2.5mm, the height is 2mm, that is, the cross-sectional area S is 5mm 2 , using the formula R=ρL / S, it can be calculated that L is 200mm, and the perimeter of the tuyere rim 1-4 of this embodiment is about 160mm. That is, when the resistance R, resistivity ρ, and cross-sectional area S of the hard conductive plastic strip 2-1 remain unchanged, L is designed to be longer than the perimeter of the tuyere rim 1-4 as much as possible. Because the perimeters of the tuyere rims of the electric dampers of air-cooled refrigerators with different specifications and capacities are different, when the overall length L of the hard conductive plastic strip 2-1 is about 25% longer than the median of the perimeter of the tuyere rim 1-4, it can be applied to most electric dampers of air-cooled refrigerators with different specifications and capacities. That is, when the overall length of the hard conductive plastic strip remains unchanged, the part of the tuyere rim that is shorter than the entire length of the hard conductive plastic strip is absorbed by adjusting the curved arrangement of the middle section of the hard conductive plastic strip located outside the outer edge. Such a design can greatly simplify the production process of the defrost module and greatly improve the versatility of the defrost module.

[0028] The defrost module in this embodiment uses PA carbon fiber composite conductive material as the heating substrate of the hard conductive plastic strip 2-1. After injection molding, its outer surface except the first metal terminal 2-2-1 and the second metal terminal 2-2-2 needs to be covered with a layer of insulating paint with a thickness of 0.1 to 0.3 mm. The purpose is to solve the problems that the conductive plastic will age faster in the humid environment of the refrigerator, and if the conductive plastic absorbs water, the resistivity will increase, causing the power of the defrost module to decrease. At the same time, it can also achieve the effect of enhancing insulation.

[0029] The defrost module may also use other conductive plastic materials, such as conductive ABS plastic material, as the heating substrate of the hard conductive plastic strip.

[0030] In this embodiment, the weight of the defrost module 2 is 4g. After testing, in a drop test in which the electric damper is dropped from a height of 1.2m in three directions, each in XYZ, twice, onto a cement floor, the defrost module 2 in the electric damper will not fall off. This exceeds the requirements of the drop test specified in the national standard GB / T35720-2017.

Claims

1. An electric air door defrosting device for an air-cooled refrigerator, comprising an air door frame (1), a rectangular air outlet (1-3) being provided in the middle of the lower part of the air door frame (1), the air outlet (1-3) being provided with a surrounding edge (1-4) consisting of two opposite long surrounding edges (1-4-1) and two opposite short surrounding edges (1-4-2), characterized in that: Two vertical cylindrical protrusions (1-2) are respectively provided on the wind door frame (1) beside the outer sides of the upper and lower parts of the long surrounding edge (1-4-1), and a baffle plate (1-6) and a vertical cylindrical first protrusion (1-10) are provided on the wind door frame (1) beside the outer sides of the short surrounding edge (1-4-2) at the upper end of the air outlet (1-3), as well as a first positioning pin (1-8) and a second positioning pin (1-10) respectively located on both sides of the baffle plate (1-6). 8); a defrost module (2) is also provided, wherein the hard conductive plastic strip (2-1) of the defrost module (2) and the first connection port (2-1-1) and the second connection port (2-1-2) are positioned and fixed in a cavity formed by the four protrusions (1-2) with umbrella-shaped barbs, the first protrusion (1-10) and the baffle plate (1-6) and are fixed in a cavity formed by the four protrusions (1-2), the first protrusion (1-10) and the air outlet surrounding edge (1-4).

2. The electric air door defrosting device for an air-cooled refrigerator according to claim 1, characterized in that: The defrost module (2) is composed of a rectangular hard conductive plastic strip (2-1), a first connection port (2-1-1) connected to the end thereof, a second connection port (2-1-2), and a first metal terminal (2-2-1) and a second metal terminal (2-2-2) respectively connected to the first connection port (2-1-1) and the second connection port (2-1-2); the first connection port (2-1-1) is provided with a first positioning hole (2-1-1-1), and the second connection port (2-1-2) is provided with a second positioning hole (2-1-2-1); the defrost module (2) is coated with a layer of insulating paint except for the first metal terminal (2-2-1) and the second metal terminal (2-2-2).

3. The electric air door defrosting device for an air-cooled refrigerator according to claim 2, characterized in that: The middle section of the hard conductive plastic strip (2-1) between the two convex pillars (1-2) on the outside of the long surrounding edge (1-4-1) is in a curved shape, the hard conductive plastic strip (2-1) is in a flat cubic shape, the first connection port (2-1-1) and the second connection port (2-1-2) are in a flat plate shape, and the cross-sectional areas of the first connection port (2-1-1) and the second connection port (2-1-2) are greater than the cross-sectional area of ​​the hard conductive plastic strip (2-1).

4. The electric air door defrosting device for an air-cooled refrigerator according to claim 2, characterized in that: The hard conductive plastic strip (2-1), the first connection port (2-1-1), the second connection port (2-1-2), the first metal terminal (2-2-1) and the second metal terminal (2-2-2) are integrally compression molded using PA carbon fiber composite conductive material to form a defrosting module (2).

5. The method for preparing and assembling the electric air door defrosting device for an air-cooled refrigerator according to claims 1 to 4, characterized in that: The method steps are as follows: ① When the air door frame (1) is injection molded, four bosses (1-2), a first boss (1-10), a first positioning pin (1-8) and a second positioning pin (1-9) are added to the outside of the air outlet surrounding edge (1-4); ② Inserting the first metal terminal (2-2-1) and the second metal terminal (2-2-2) into corresponding positions in the inner cavity of the mold, and then injecting the PA carbon fiber composite conductive material into the mold cavity by an injection molding machine, so that the defrosting module (2) is formed; ③ Coating a layer of insulating paint with a thickness of 0.1 to 0.3 mm on the hard conductive plastic strip (2-1), the first connection port (2-1-1) and the second connection port (2-1-2) of the defrost module (2), and drying the coating; ④ Placing the painted defrost module (2) in the outer cavity of the air outlet surround (1-4), and positioning it by means of the first positioning pin (1-8), the first positioning hole (2-1-1-1) and the second positioning pin (1-9), the second positioning hole (2-1-2-1); ⑤ Using a hot press machine to hot press the upper parts of the four convex columns (1-2) into umbrella-shaped hooks (1-2-1), the bottom planes of the umbrella-shaped hooks (1-2-1) being positioned, contacted and connected with the upper planes of the corresponding hard heat-conductive plastic strips (2-1); using a hot press machine to hot press the upper part of the first convex column (1-10) into an umbrella-shaped hook (1-2-1), the bottom planes of the umbrella-shaped hooks (1-2-1) being snap-fitted and fixedly connected with the upper planes of the corresponding first connection ports (2-1-1) and the upper planes of the second connection ports (2-1-2); thus forming an electric damper of an air-cooled refrigerator with a defrosting device.

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