Novel annular PTC heater

Abstract

The utility model provides a novel annular PTC (Positive Temperature Coefficient) heater, which comprises a plurality of cuboid heating bodies which are integrally bonded by radiating strips and PTC heating units, the plurality of cuboid heating bodies are arranged into an arc-shaped ring belt according to a certain angle, outer ring radiating strips of the ring belt formed by outer electrode plates and the heating bodies are integrally connected, and the PTC heating units are arranged in the arc-shaped ring belt. And the inner electrode plate is connected with the inner ring heat dissipation strip of the ring belt formed by the heating body into a whole. 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 utilize the characteristics of PTC (positive temperature coefficient) materials for heating. It can generate heat by itself when powered on, and has the advantages of high thermal efficiency, large power, no open flame, and safety. 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 bath heaters, air purifiers and other fields.

[0003] However, for the current annular PTC heaters on the market, the conductor heat dissipation strips are first made into circular arcs, and then multiple rectangular PTC ceramic heating elements are placed between the inner and outer heat dissipation strips of the circular arc. 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 fin must be in contact with the conductive surface of the PTC ceramic heating element. However, since the conductive surface of the PTC ceramic heating element is rectangular, there is always a gap between the rectangular conductive surface and the circular arc surface of the heat dissipation strip that cannot be in contact. The gap here is extremely prone to arcing, seriously affecting the safety and service life of the PTC heater. In addition, when the circular arc heat dissipation fin and the rectangular PTC ceramic heating element are pressed and solidified, the sheet-shaped PTC ceramic heating element is 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: a rectangular heating body in which a heat dissipation strip and a PTC heating unit are bonded together; a plurality of rectangular heating bodies are arranged at a certain angle to form an arc-shaped ring belt; an outer electrode sheet is fixedly connected to the outer ring heat dissipation strip of the ring belt formed by the heating bodies as a whole; and an inner electrode sheet is fixedly connected to the inner ring heat dissipation strip of the ring belt formed by the heating bodies as a whole.

[0005] Further, the fixed connection between the inner electrode sheet, the outer electrode sheet and the PTC heating body can be laser welding, riveting, or bonding.

[0006] Furthermore, the general manufacturing process of the above cuboid PTC heating element 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 solidify the PTC ceramic heating element and the heat dissipation strips into one body. 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 is 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 heating element.

[0007] Furthermore, the above PTC heater is arranged to be used in the annular groove of an arc-shaped housing. The bottom surface of the groove is upward, and a plurality of trapezoidal rib blocks are arranged at intervals in the radial direction. The two ends of the trapezoidal rib blocks are connected to the two walls of the groove. The radial planar shape of the trapezoidal rib blocks matches the shape of the gap formed between the PTC heating elements when they are arranged in a ring, so as to block the cold air flowing through the gap area between the two PTC heating elements and direct the air flow above the PTC heating elements, enabling the cold air flow to be fully heated.

[0008] Furthermore, the bottom of the annular groove of the arc-shaped housing is a hollow structure, which is an air flow channel. Ribs are left 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 sheet plus the thickness of the connection plate of the heat dissipation strip to support the electrode sheet and the PTC heating element.

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

[0010] Furthermore, in order to control the temperature of the PTC heater, a thermostat can be provided outside the above-mentioned outer electrode sheet to control the surface temperature of the PTC. Further, in order to protect the thermostat, a thermostat box is provided outside it.

[0011] Furthermore, in order to install the thermostat, a card slot for the thermostat is provided on the outer side of the arc-shaped housing.

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

[0013] Furthermore, the material of the arc-shaped housing is plastic with a temperature resistance of 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 elements are approximately assembled into an annular PTC heater. The process of the cuboid PTC heating element 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 stress 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 description in 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 also be obtained based on these drawings.

[0017] Figure 1 It is a schematic diagram of a new type of annular PTC heater assembly

[0018] Figure 2 It is an exploded view of a new type of annular PTC heater

[0019] Figure 3 It is a schematic diagram of a PTC heating monomer

[0020] Figure 4 It is a schematic diagram of an arc-shaped housing

[0021] Figure 5 It is a schematic diagram of an electrode plate

[0022] Figure 6 It is a schematic diagram of a PTC heating element in another embodiment

[0023] 1 - PTC heating element; 11 - heat dissipation strip; 12 - PTC ceramic heating element; 111 - connecting plate; 2 - electrode plate; 21 - outer electrode plate; 22 - inner electrode plate; 201 - electrical connection point; 3 - arc-shaped housing; 31 - groove; 32 - rib; 33 - trapezoidal rib block; 34 - buckle; 35 - thermostat slot; 4 - thermostat; 5 - thermostat housing; DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] The following will describe the exemplary embodiments of the present application in detail with reference to the 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 terms such as "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 on the present utility model.

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

[0027] The following further describes the design in conjunction with the structural specification drawings.

[0028] Such as Figure 1 and Figure 2 As shown by way of example, a novel annular PTC heater includes: a cuboid PTC heating body (1) in which a heat dissipation strip (11) and a PTC heating unit (12) are bonded together; a plurality of cuboid heating bodies (1) are arranged at a certain angle to form an arc-shaped ring belt; an outer electrode sheet (21) is fixedly connected to the outer heat dissipation strip (11) of the ring belt formed by the heating body (1) as a whole; and an inner electrode sheet (22) is fixedly connected to the inner heat dissipation strip (11) of the ring belt formed by the heating body as a whole.

[0029] Furthermore, the fixing connection manner between the above-mentioned outer electrode sheet (21) and the inner electrode sheet (22) and the PTC heating body (1) can be selected as laser welding, riveting, or bonding, etc., which fixes the two together.

[0030] Such as Figure 3 and Figure 6The general manufacturing process of the above-mentioned cuboid PTC body (1) is as follows: First, apply thermal conductive glue on the two opposite electrode surfaces of the PTC ceramic heating element (12). Next, place the two heat dissipation strips (11) on both sides of the PTC ceramic heating element (12) with thermal conductive glue, or apply thermal conductive glue on the outer side surfaces of the opposite connection plates (111) of the two heat dissipation strips, and arrange the PTC ceramic heating element (12) between the two connection plates (111) with thermal conductive glue. Then, apply pressure for curing to cure the PTC ceramic heating element (12) and the heat dissipation strips (11) into one body. Here, the material of the heat dissipation strips (11) 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 (12), and the other is to quickly dissipate the heat generated by the PTC ceramic heating element (12). Since the heat dissipation strips (11) and the PTC ceramic heating element (12) have the same shape and both adopt a cuboid structure, and the two conductors are in a relatively close-fitting state, after power-on, the phenomenon of arcing is effectively avoided between the two conductors, improving the safety of product use. In addition, during curing and pressurization, the entire plane of the PTC ceramic heating element (12) is relatively evenly stressed, effectively avoiding the risk of crushing the PTC ceramic heating element (12) due to uneven stress, and effectively improving the service life of the PTC body (1).

[0031] Embodiment 1

[0032] As Figure 4 shown, the above-mentioned PTC heater is used in the annular groove (31) of an arc-shaped housing (3). The bottom surface of the groove (31) is upward, and a plurality of trapezoidal rib blocks (33) are arranged at intervals in the radial direction. Its two ends are connected to the two walls of the groove (31). The radial planar shape of the trapezoidal rib block (33) matches the shape of the gap formed between the two PTC heating bodies (1) when arranged in a ring, so as to block the cold air flowing through the gap area between the two PTC heating bodies (1) and direct the air flow above the PTC heating body (1) to fully heat the cold air flow.

[0033] As Figure 4 shown, the bottom of the groove (31) of the arc-shaped housing (3) is a hollow structure, and rib strips (32) are left at the inner and outer edges of the bottom surface of the groove (31). Its width is equal to the thickness of the electrode plate (2) plus the thickness of the heat dissipation strip connection plate (111) to support the electrode plate (2) and the PTC heating body (1).

[0034] As Figure 4 shown, a number of fasteners (34) are provided on both sides of the two axial inner walls at the top of the groove (31) to firmly clamp the annular PTC heater installed in the annular groove.

[0035] As Figure 2As shown, in order to control the temperature of the PTC heater, a thermostat (4) can be arranged outside the outer electrode sheet (21) above to control the surface temperature of the PTC heater. When the temperature reaches the preset opening threshold of the thermostat (4), the thermostat (4) trips and the circuit is cut off. When the temperature drops to the closing threshold of the thermostat (4), the thermostat (4) closes and the circuit is connected, and the PTC heater operates. Further, in order to protect the thermostat (4), a thermostat box (5) is arranged outside it.

[0036] As Figure 4 shown, in order to install the thermostat (4) and the thermostat box (5), a thermostat card slot (35) is arranged outside the arc-shaped housing (3) above.

[0037] As Figure 5 shown, an electrical connection point (201) is arranged at one end of the electrode sheet (2) to connect to an external power supply.

[0038] Furthermore, the material of the arc-shaped housing (3) is selected from different heat-resistant plastics according to the working surface temperature of the PTC heating unit, and its heat resistance is 80°C to 300°C, so as to ensure that the arc-shaped housing does not deform at high temperatures when the PTC heater operates, and to improve the service life of the product.

[0039] As Figure 6 Embodiment 2

[0040] The difference between Embodiment 2 and Embodiment 1 is that a connecting plate (111) can be added at the connection between the heat dissipation strip (11) and the PTC ceramic heating element (12) to enhance the electrical connection strength between the heat dissipation strip (11) and the PTC ceramic heating element (12), and to improve the uniformity of the force on the surface of the PTC ceramic heating element during pressure curing.

[0041] 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 variations 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, practical applications, or improvements to the technologies 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: a cuboid PTC heating body (1) in which heat dissipation strips (11) and PTC heating units (12) are bonded together; a plurality of cuboid heating bodies (1) are arranged at a certain angle to form an arc-shaped annular belt; an outer electrode sheet (21) is fixedly connected to the outer ring heat dissipation strip (11) of the annular belt formed by the heating body (1) as a whole; an inner electrode sheet (22) is fixedly connected to the inner ring heat dissipation strip (11) of the annular belt formed by the heating body as a whole.

2. The novel annular PTC heater according to claim 1, wherein: The fixing connection method of the outer electrode sheet (21), the inner electrode sheet (22) and the PTC heating body (1) is welding.

3. A novel annular PTC heater according to claim 1, characterized in that: The fixing connection method of the outer electrode sheet (21), the inner electrode sheet (22) and the PTC heating body (1) is riveting.

4. A novel annular PTC heater according to claim 1, wherein: The PTC heater is arranged in an annular groove (31) of an arc-shaped housing (3). A plurality of trapezoidal rib blocks (33) are arranged at intervals in the radial direction with the bottom surface of the groove (31) facing upward. The two ends of the trapezoidal rib blocks (33) are connected to the two walls of the groove (31). The radial planar shape of the trapezoidal rib blocks (33) matches the shape of the gap formed between the PTC heating bodies (1) when arranged in an annular shape, so as to block the cold air flowing through the gap area between the two PTC heating bodies (1) and direct the air flow above the PTC heating body (1), so that the cold air flow can be fully heated.

5. A novel annular PTC heater according to claim 4, wherein: The bottom of the groove (31) of the arc-shaped housing (3) is a hollow structure. Rib strips (32) are provided at the inner and outer edges of the bottom surface of the groove (31), 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 (111) to support the electrode sheet (2) and the PTC heating body (1).

6. The novel annular PTC heater according to claim 5, characterized in that: A number of buckles (34) are provided on both sides of the two axial inner walls at the top of the groove (31) to firmly clamp the annular PTC heater installed in the annular groove.

7. A novel annular PTC heater according to claim 6, characterized in that: A thermostat (4) and a thermostat box (5) are arranged outside the outer electrode sheet (21) to control the temperature of the PTC heater.

8. A novel annular PTC heater according to claim 7, characterized in that: A thermostat card slot (35) is provided outside the arc-shaped housing (3).

9. A novel annular PTC heater according to any one of claims 1 to 8, characterized in that: The electrode sheet (2) is provided with an electrical connection point (201) at one end to connect to an external power supply.

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