Novel annular PTC heater

Abstract

The utility model provides a novel annular PTC heater, which comprises an arc-shaped shell, an annular groove arranged on an annular belt of the arc-shaped shell, an inner electrode plate and an outer electrode plate respectively arranged on two inner wall sides of the annular groove, and a plurality of cuboid PTC heating units arranged between the inner electrode plate and the outer electrode plate. The opposite sides of the inner electrode plate and the outer electrode plate are respectively provided with a plurality of elastic clamping jaws for fixing the PTC heating unit. The PTC heater has the beneficial effects that the plurality of cuboid PTC heating bodies are approximately spliced into the annular PTC heater, the process of the cuboid PTC heating bodies is simple and mature, and the sparking phenomenon caused by a gap between a circular heat dissipation strip and a cuboid PTC ceramic heating element is effectively solved; and the condition that the PTC ceramic heating element is crushed due to non-uniform stress on the surface of the PTC ceramic heating element during pressurization and fixation is effectively avoided, the use safety of the PTC heater is effectively improved, and the service life of the PTC heater is effectively prolonged.

Description

Technical Field

[0001] The utility model belongs to the technical field of PTC heaters, and particularly relates to a novel annular PTC heater. Background Art

[0002] A PTC (positive temperature coefficient) electric heater is an electric heater based on semiconductor materials. Its working principle is to use the characteristics of PTC (positive temperature coefficient) materials for heating. It can generate heat by itself in the energized state, and has the advantages of high thermal efficiency, high power, no open flame, safety, etc. It is an ideal material for heating devices. Among them, the annular PTC heater is generally installed in an axially extending air flow channel and can blow warm air 360°. Therefore, it is often applied to occasions where uniform air outlet is required, such as warm air bathroom heaters, air purifiers and other fields.

[0003] However, for the annular PTC heaters currently on the market, the conductor heat dissipation strips are first made into an arc shape, and then multiple rectangular PTC ceramic heating elements are placed between the inner and outer heat dissipation strips of the arc shape. In addition to heat dissipation, the heat dissipation strips also have a particularly important function of providing positive and negative electrodes for the PTC ceramic heating elements. This requires that the arc surface of the heat dissipation fins must be in contact with the conductive surface of the PTC ceramic heating elements. However, since the conductive surface of the PTC ceramic heating elements is rectangular, there are always gaps in the contact surface between the rectangular conductive surface and the arc shape of the heat dissipation strips. The gaps here are extremely prone to sparking, seriously affecting the safety and service life of the PTC heater. In addition, when the arc-shaped heat dissipation fins and the rectangular PTC ceramic heating elements are pressurized and solidified, the sheet-shaped PTC ceramic heating elements are prone to being crushed due to uneven stress, which will also affect the service life of the PTC heater. Summary of the Utility Model

[0004] In order to solve the above problems, the utility model provides a novel annular PTC heater, including: an arc-shaped housing, which is provided with an annular groove on its annular belt, and inner electrode sheets and outer electrode sheets are respectively provided on both inner wall sides of the annular groove. A plurality of rectangular PTC heating units are arranged between the inner electrode sheet and the outer electrode sheet, and a plurality of elastic claws are respectively provided on the opposite sides of the inner electrode sheet and the outer electrode sheet to fix the PTC heating units.

[0005] Furthermore, the general manufacturing process of the above cuboid PTC heating unit is as follows: First, apply thermal conductive adhesive to the two opposite electrode surfaces of the PTC ceramic heating element. Next, place the two heat dissipation strips on both sides of the PTC ceramic heating element with thermal conductive adhesive, or apply thermal conductive adhesive to the outer side surfaces of the opposite connection plates of the two heat dissipation strips, and arrange the PTC ceramic heating element between the two connection plates with thermal conductive adhesive. Then, apply pressure for curing to integrate the PTC ceramic heating element and the heat dissipation strips. Here, the material of the heat dissipation strip is preferably metal aluminum with a large thermal conductivity coefficient, and it has two main functions. One is to provide electrodes for the PTC ceramic heating element, and the other is to quickly dissipate the heat generated by the PTC ceramic sheet. Since the heat dissipation strip and the PTC ceramic heating element have the same shape and both adopt a cuboid structure, and the two conductors are in a relatively fitting state, after power-on, arcing between the two conductors can be effectively avoided. In addition, when applying pressure for curing, the entire plane of the PTC ceramic heating element is relatively evenly stressed, effectively avoiding the risk of crushing the PTC ceramic heating element due to uneven stress, and effectively improving the safety and service life of the PTC heater.

[0006] Furthermore, the bottom of the annular groove of the arc-shaped housing is a hollow structure, which serves as an air flow channel. Ribs are provided at the inner and outer edges of the bottom surface of the annular groove, and the width thereof is equal to the thickness of the electrode plate plus the thickness of the connection plate of the heat dissipation strip to support the electrode plate and the PTC heating unit.

[0007] Furthermore, a plurality of trapezoidal rib blocks are arranged at intervals in the upward and radial directions on the bottom surface of the annular groove, and both ends thereof are connected to the two walls of the groove. The radial planar shape of the trapezoidal rib block matches the shape of the gap formed between two PTC heater units when arranged in a circular pattern, so as to block the cold air flowing through the gap area between the two heating units and direct the air flow above the PTC heating unit, enabling the cold air flow to be fully heated. The axial thickness of the trapezoidal rib block matches the height of the slot of the electrode plate, so that the electrode plate can be inserted into the arc-shaped housing.

[0008] Furthermore, the trapezoidal rib blocks can also be respectively arranged crosswise on the upper and lower inner sides of the inner wall of the annular groove to strengthen the connection strength between the two axial inner walls of the annular groove of the arc-shaped housing. Similarly, the trapezoidal rib blocks block the cold air flowing through the gap area between the two heating units and direct the air flow above the PTC heating unit, enabling the cold air flow to be fully heated.

[0009] Furthermore, a number of buckles are provided on both sides of the two axial inner walls at the top of the annular groove to firmly clamp the electrode plate and the PTC heating unit installed in the annular groove.

[0010] Further, a plurality of elastic claws are arranged at the same intervals in the length direction of the electrode sheet. The intervals here match the length of the PTC heating unit. The middle area of the elastic claws is set to an arc shape that turns outwards to prevent scratching the surface of the PTC heating unit when it is inserted, and at the same time, it is also easy for the installation, disassembly and maintenance of the PTC heating unit. The contact points of the elastic claws and the PTC heating unit are located at the middle position in the height direction of the PTC heating unit to ensure the clamping force of the elastic claws on the PTC heating unit.

[0011] Further, a plurality of slots are arranged at the same intervals in the length direction of the electrode sheet. The width and height of the slots match the width and thickness of the trapezoidal rib blocks of the arc-shaped housing.

[0012] Further, an electrical connection point is arranged at one end of the electrode sheet to connect to an external power supply.

[0013] Further, the arc-shaped housing is made of plastic that can withstand temperatures from 80°C to 300°C.

[0014] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0015] A plurality of cuboid PTC heating bodies are approximately assembled into an annular PTC heater. The process of the cuboid PTC heater body is simple, mature, and effectively solves the problem of arcing between the circular heat dissipation strip and the cuboid PTC ceramic heating element due to the existence of a gap, and effectively avoids the situation of crushing due to uneven force on the surface of the PTC ceramic heating element during pressure fixation, effectively improving the safety and service life of the PTC heater. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present utility model, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following described drawings are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0017] Figure 1 It is a schematic diagram of the annular PTC heater assembly of this embodiment

[0018] Figure 2 It is an exploded view of the annular PTC heater of this embodiment

[0019] Figure 3 It is a schematic diagram of the PTC heating unit of this embodiment

[0020] Figure 4 It is a schematic diagram of the arc-shaped housing of this embodiment

[0021] Figure 5 It is a schematic diagram of the electrode sheet of this embodiment

[0022] Figure 6 It is a schematic diagram of another embodiment of the PTC heating unit

[0023] 1 - Arc-shaped housing; 11 - Annular groove; 12 - Rib; 13 - Trapezoidal rib block; 14 - Snap; 2 - Electrode plate; 21 - Inner electrode plate; 22 - Outer electrode plate; 201 - Elastic claw; 202 - Slotted; 203 - Electrical connection point; 3 - PTC heating unit; 31 - Heat dissipation strip; 32 - PTC ceramic heating element; 311 - Connecting plate Detailed implementation manners

[0024] The exemplary embodiments of the present application will be described in detail below with reference to the accompanying drawings. The same reference numerals in the drawings denote elements having the same or similar functions. Although various aspects of the embodiments are shown in the drawings, the drawings do not have to be drawn to scale unless otherwise specified

[0025] Among them, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present utility model or simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present utility model

[0026] The special term "exemplary" here means "serving as an example, embodiment or illustration". Any embodiment described as "exemplary" here does not have to be construed as superior to or better than other embodiments

[0027] The design will be further described below in conjunction with the structure specification drawings

[0028] As Figure 1 and Figure 2 As shown in the exemplary, a new type of annular PTC heater includes: an arc-shaped housing 1, an annular groove 11 is provided on its annular belt, inner electrode plates 21 and outer electrode plates (22) are respectively provided on both inner wall sides of the annular groove 11, and a plurality of cuboid PTC heating units (3) are provided between the inner electrode plate (21) and the outer electrode plate (22), and a plurality of elastic claws 201 are respectively provided on the opposite sides of the inner electrode plate 21 and the outer electrode plate (22) to fix the PTC heating unit 3

[0029] As Figure 3 and Figure 6The general manufacturing process of the above-mentioned cuboid PTC heating unit is as follows: First, apply thermal conductive glue to the two opposite electrode surfaces of the PTC ceramic heating element 32. Next, place the two heat dissipation strips 31 on both sides of the PTC ceramic heating element 32 with thermal conductive glue, or apply thermal conductive glue to the outer side surfaces of the opposite connection plates 311 of the two heat dissipation strips, and arrange the PTC ceramic heating element 32 between the two connection plates 311 with thermal conductive glue. Then, apply pressure for curing to solidify the PTC ceramic heating element 32 and the heat dissipation strips 31 into one body. Here, the material of the heat dissipation strips 31 is preferably metal aluminum with a large thermal conductivity coefficient, and it has two main functions. One is to provide electrodes for the PTC ceramic heating element 32, and the other is to quickly dissipate the heat generated by the PTC ceramic heating element 32. Since the heat dissipation strips 31 and the PTC ceramic heating element 32 have the same shape and both adopt a cuboid structure, and the two conductors are in a relatively close-fitting state, after power-on, arcing between the two conductors is effectively avoided, improving the safety of product use. In addition, when curing and applying pressure, the entire plane of the PTC ceramic heating element 32 is relatively evenly stressed, effectively avoiding the risk of crushing the PTC ceramic heating element 32 due to uneven stress, and effectively improving the service life of the PTC heater. Embodiment

[0030] As Figure 4 shown, the bottom of the annular groove 11 of the arc-shaped housing 1 is a hollow structure, and ribs 12 are provided at the inner and outer edges of the bottom surface of the annular groove 11. Its width is equal to the thickness of the electrode plate 2 plus the thickness of the heat dissipation strip connection plate 311 to support the electrode plate 2 and the PTC heating unit 3. A plurality of trapezoidal rib blocks 13 are arranged at intervals in the radial direction upward from the bottom surface of the annular groove 11. Both ends of the trapezoidal rib blocks 13 are connected to the two walls of the groove 11. The radial plane shape of the trapezoidal rib blocks 13 matches the shape of the gap formed between the two when the PTC heater units 3 are arranged in a ring, so as to block the cold air flowing through the gap area between the two PTC heating units 3 and direct the air flow above the PTC heating units 3 to fully heat the cold air flow. The axial thickness of the trapezoidal rib blocks 13 matches the height of the slot 202 of the electrode plate 2, and the axial thickness of the trapezoidal rib blocks 13 matches the height of the slot 202 of the electrode plate 2 so that the electrode plate 2 can be inserted into the arc-shaped housing 1.

[0031] As Figure 4 shown, a number of buckles 14 are provided oppositely on both sides of the two axial inner walls at the top of the annular groove 11 to firmly clamp the electrode plate 2 and the PTC heating unit 3 installed in the annular groove.

[0032] As Figure 5As shown, a plurality of elastic claws 201 are arranged at the same intervals in the length direction of the electrode sheet 2. The interval here matches the length of the PTC heating unit 3. The middle area of the elastic claws 201 is set to an outwardly turned arc shape to prevent scratching the surface of the PTC heating unit 3 when it is inserted, and at the same time, it is also easy for the installation, disassembly and maintenance of the PTC heating unit 3. The contact points between the elastic claws 201 and the PTC heating unit 3 are at the middle position in the height direction of the PTC heating unit 3 to ensure the clamping force of the elastic claws 201 on the PTC heating unit 3.

[0033] As Figure 5 shown, a plurality of slots 202 are arranged at the same intervals in the length direction of the electrode sheet 2. The width and height of the slots 202 match the width and thickness of the trapezoidal rib blocks 13 of the arc-shaped housing. An electrical connection point 202 is arranged at one end of the electrode sheet 2 to connect to an external power supply.

[0034] Furthermore, the material of the arc-shaped housing 1 is a plastic that can withstand temperatures from 80°C to 300°C to ensure that the arc-shaped housing does not deform at high temperatures when the PTC heater is working, and to improve the service life of the product. Embodiment

[0035] The difference between Embodiment 2 and Embodiment 1 is that: the trapezoidal rib blocks 13 can also be cross-arranged on the upper and lower inner sides of the inner wall of the annular groove 11 to strengthen the connection strength between the two axial inner walls of the annular groove 11 of the arc-shaped housing. Similarly, the trapezoidal rib blocks 13 block the cold air flowing through the gap area between the two PTC heating units 3 and direct the air flow above the PTC heating units 3, so that the cold air flow can be fully heated.

[0036] As Figure 6 Embodiment 3

[0037] The difference between Embodiment 3 and Embodiment 1 is that: a connecting plate 311 can be added at the connection between the heat dissipation strip 31 and the PTC ceramic heating element 32 to enhance the electrical connection strength between the heat dissipation strip 31 and the PTC ceramic heating element 32, and to improve the evenness of the force on the surface of the PTC ceramic heating element during pressure curing.

[0038] The embodiments of the present application have been described above. The above description is exemplary and not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes are obvious to those of ordinary skill in the art in the technical field without departing from the scope and spirit of the described embodiments. The selection of the terms used herein is intended to best explain the principles of the embodiments, the practical application or the improvement of the technology in the market, or to enable other ordinary technical personnel in the technical field to understand the embodiments disclosed herein.

Claims

1. A novel annular PTC heater, characterized by comprising: an arc-shaped housing (1), on the annular belt of the arc-shaped housing (1) there is an annular groove (11), on the two inner wall sides of the annular groove (11) there are respectively arranged an inner electrode sheet (21) and an outer electrode sheet (22), between the inner electrode sheet (21) and the outer electrode sheet (22) there are arranged a plurality of cuboid PTC heating units (3), and on the opposite sides of the inner electrode sheet (21) and the outer electrode sheet (22) there are respectively arranged a plurality of elastic claws (201) to fix the PTC heating units (3).

2. The novel annular PTC heater according to claim 1, wherein: The PTC heating unit (3) is composed of a cuboid heat dissipation strip (31) and a cuboid PTC ceramic heating element, and the two are connected by a heat-conducting adhesive.

3. The novel annular PTC heater according to claim 2, wherein: On the bottom surface of the annular groove (11), a plurality of trapezoidal rib blocks (13) are arranged at intervals in the upward and radial directions, the two ends of which are connected to the two walls of the groove (11), and the radial planar shape of the trapezoidal rib blocks (13) matches the shape of the gap formed between the PTC heating units (3) when they are arranged in an annular pattern, so as to block the cold air flowing through the gap area between the two PTC heating units (3), direct the air flow above the PTC heating units (3), and enable the cold air flow to be fully heated. The axial thickness of the trapezoidal rib blocks (13) matches the height of the slot (202) of the electrode sheet (2), so that the electrode sheet (2) can be inserted into the arc-shaped housing (1).

4. The novel annular PTC heater according to claim 3, characterized in that: On the upper and lower inner sides of the inner wall of the annular groove (11) in the axial direction, trapezoidal rib blocks (13) are arranged crosswise.

5. The novel annular PTC heater according to claim 4, wherein: The bottom of the annular groove (11) of the arc-shaped housing (1) is a hollow structure, and ribs (12) are left at the inner and outer edges of the bottom surface of the annular groove (11), and the width thereof is equal to the sum of the thickness of the electrode sheet (2) and the thickness of the heat dissipation strip connecting plate (311), so as to support the electrode sheet (2) and the PTC heating unit (3).

6. A novel annular PTC heater according to claim 5, characterized in that: On the two axial inner walls on both sides of the top of the annular groove (11), a number of buckles (14) are arranged opposite to each other, so as to firmly clamp the electrode sheet (2) and the PTC heating unit (3) installed in the annular groove.

7. A novel annular PTC heater according to claim 6, characterized in that: On the electrode sheet (2), a plurality of elastic claws (201) are arranged at the same interval in the length direction, the interval here matches the length of the PTC heating unit (3), the middle area of the elastic claws (201) is set to an outwardly turned arc shape, and the contact point of the elastic claws (201) with the PTC heating unit (3) is at the middle position in the height direction of the PTC heating unit (3).

8. A novel annular PTC heater according to claim 7, characterized in that: On the electrode sheet (2), a plurality of slots (202) are arranged at the same interval in the length direction, and the width and height of the slots (202) match the width and thickness of the trapezoidal rib blocks (13) of the arc-shaped housing.

9. The novel annular PTC heater according to claim 8, wherein: On one end of the electrode sheet (2), an electrical connection point (203) is arranged to connect to an external power supply.

10. A novel annular PTC heater according to any one of claims 1 to 9, characterized in that: The material of the arc-shaped housing (1) is a plastic that can withstand temperatures from 80°C to 300°C.

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