A double-layer preheating furnace for polyurethane foaming process

Abstract

This utility model discloses a double-layer preheating furnace for polyurethane foaming processes, belonging to the technical field of processing equipment. It includes two independently arranged furnace bodies for simultaneously preheating two workpieces. Each furnace body has an upper and lower air duct, and a circulating fan is located on the side of the furnace body to drive hot air from the upper and lower hot air outlets to the central area of ​​the furnace body, forming a closed-loop circulation through the upper and lower hot air return inlets. A furnace temperature sensor is located on each of the left and right sides of the central area of ​​the furnace body. Non-contact surface temperature sensors and skeleton temperature sensors are respectively located at the upper and lower rear of the furnace body. The furnace temperature sensors, surface temperature sensors, skeleton temperature sensors, and circulating fan are connected to a control module. This preheating furnace can significantly improve the uniformity of temperature within the furnace, accurately monitor and control the temperature of the plastic skeleton and surface, reduce energy waste, lower the scrap rate, and meet the production requirements of high-quality polyurethane foaming.

Description

Technical Field

[0001] This utility model belongs to the field of processing equipment technology, specifically relating to a double-layer preheating furnace for polyurethane foaming process. Background Technology

[0002] Polyurethane foaming is a commonly used technology in automotive interior manufacturing. Before foaming, the plastic skeleton and skin need to be preheated to ensure the stability of the foaming process, the adhesion of the foam, and the bonding of the skin. However, existing preheating furnaces have the following problems:

[0003] 1) Due to the simple design of the air duct, the air temperature inside the furnace is uneven, resulting in a large temperature gradient;

[0004] 2) Monitoring only the air temperature cannot accurately reflect the temperature of the plastic frame and skin, leading to energy waste and even the generation of scrap due to excessively high or low part temperatures.

[0005] Existing technology CN201720158045 provides a bidirectional heating furnace that alternately changes the direction of hot air through an air exchange mechanism, thereby solving the problem of large temperature differences in traditional heating furnaces. However, this solution has a complex mechanical structure and control program, is bulky, and difficult to maintain; furthermore, it only monitors the hot air temperature and cannot confirm the actual temperature of the components.

[0006] Existing technology CN202420182256 provides a furnace for heating automotive interior parts, equipped with a double-layer conveyor belt to heat the surface and frame separately, improving processing efficiency. It also employs a multi-point air outlet and return assembly to ensure uniform airflow within the furnace. However, it only monitors the hot air temperature and cannot confirm the actual temperature of the parts; furthermore, the frame and surface are placed directly on the conveyor belt without a bottom support, preventing the hot air from diffusing evenly from bottom to top, thus affecting the uniformity of heating. Utility Model Content

[0007] To address the problems of uneven air temperature and inaccurate monitoring of plastic skeleton and skin temperature in existing preheating equipment, this invention provides a double-layer preheating furnace for polyurethane foaming processes. This preheating furnace can significantly improve the uniformity of temperature inside the furnace, accurately monitor and control the temperature of plastic skeleton and skin, reduce energy waste, lower scrap rate, and meet the production requirements of high-quality polyurethane foaming.

[0008] This utility model is achieved through the following technical solution:

[0009] A double-layer preheating furnace for polyurethane foaming processes includes two independently arranged furnace bodies for simultaneously preheating two workpieces. A metal support 13 is located at the center of the bottom of each furnace body for placing the preheated workpieces. Each furnace body has an upper air duct and a lower air duct. The upper air duct includes multiple upper hot air outlets 16 on the upper surface of the furnace body and upper hot air return inlets 17 on the side. The lower air duct includes multiple lower hot air outlets 19 on the lower surface of the furnace body and lower hot air return inlets 18 on the side. A circulating fan is located on the side of the furnace body to drive hot air from the upper and lower hot air outlets 16 and 19 towards the center of the furnace body. The furnace body is equipped with a furnace temperature sensor 10 on each side of the middle area for real-time temperature detection. Non-contact surface temperature sensor 15 and frame temperature sensor 14 are respectively located at the upper and lower rear of the furnace body for real-time workpiece temperature detection. The furnace temperature sensor 10, surface temperature sensor 15, frame temperature sensor 14, and circulating fan are connected to the control module 4. When the detected values ​​of the surface temperature sensor 15 and frame temperature sensor 14 reach the preset upper limit, the control module 4 cuts off the heating power.

[0010] Furthermore, the circulating fan includes an upper circulating fan 2 and a lower circulating fan 3. The upper circulating fan 2 is located at the upper side of the furnace body and is used to control the heat circulation of the upper air duct; the lower circulating fan 3 is located at the lower side of the furnace body and is used to control the heat circulation of the lower air duct.

[0011] Furthermore, the height of the supporting surface of the metal bracket 13 is adjustable and it is fixed to the bottom of the furnace body by the positioning guide rail 12.

[0012] Furthermore, the bottom of the metal bracket 13 is provided with a sliding component that engages with the positioning guide rail 12.

[0013] Furthermore, a parts detection switch 9 is provided at the bottom of the furnace body. The parts detection switch 9 is connected to the control module 4. When no parts are detected in the furnace, heating is automatically stopped.

[0014] Furthermore, a transparent, foldable crystal curtain 7 is provided at the opening of the furnace body, and magnetic strips 6 are provided on the edge of the crystal curtain 7 for magnetic attraction with the furnace body to achieve a seal.

[0015] Furthermore, the crystal curtain 7 is connected to the furnace body via a slide rail 8. A crystal curtain position switch 11 is provided on the end face of the furnace body to detect whether the crystal curtain is closed in place. The crystal curtain position switch 11 is connected to the control module 4. When it is detected that the crystal curtain is not closed in place, the three-color light 1 is triggered to alarm, preventing heat dissipation during the heating process.

[0016] Furthermore, FOM casters 5 are installed at the bottom of the furnace body to facilitate the movement of the furnace body.

[0017] Compared with the prior art, the advantages of this utility model are as follows:

[0018] 1. Temperature uniformity is significantly improved;

[0019] By combining the upper and lower dual air duct design with the side circulation fan, bidirectional hot air blowing and forced circulation are achieved, effectively solving the problem of uneven temperature distribution inside the furnace.

[0020] 2. Accurate and comprehensive temperature monitoring;

[0021] The furnace temperature sensor is used to monitor the furnace environment at two points, and a non-contact skin / skeleton temperature sensor is used to detect the temperature of key parts of the workpiece in real time, so that the data is more in line with actual production needs.

[0022] 3. Intelligent energy-saving control;

[0023] The heating power supply is automatically cut off based on the actual temperature of the workpiece (skin / frame), and a workpiece detection switch is added to achieve automatic shutdown when there are no parts, thus implementing a dual energy-saving mechanism.

[0024] 4. Flexible and efficient structure;

[0025] The adjustable height metal bracket works in conjunction with the positioning rail to adapt to different products and allow for quick replacement; the transparent magnetic crystal curtain balances sealing and ease of operation, improving work efficiency. Attached Figure Description

[0026] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0027] Figure 1 This is a schematic diagram of the structure of a double-layer preheating furnace for polyurethane foaming process according to the present invention.

[0028] Figure 2 This is a partial schematic diagram of a double-layer preheating furnace for polyurethane foaming process according to the present invention.

[0029] Figure 3 This is a schematic diagram of the hot air circulation in a double-layer preheating furnace for polyurethane foaming process according to the present invention.

[0030] In the diagram: 1. Three-color light; 2. Upper circulating fan; 3. Lower circulating fan; 4. Control module; 5. Fuma caster; 6. Magnetic strip; 7. Crystal curtain; 8. Slide rail; 9. Part detection switch; 10. Furnace temperature sensor; 11. Crystal curtain position switch; 12. Positioning guide rail; 13. Bracket; 14. Frame temperature sensor; 15. Surface temperature sensor; 16. Upper hot air outlet; 17. Upper hot air return port; 18. Lower hot air return port; 19. Frame; 20. Surface. Detailed Implementation

[0031] To clearly and completely describe the technical solution and its specific working process of this utility model, the specific embodiments of this utility model are as follows, in conjunction with the accompanying drawings:

[0032] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0033] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0034] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0035] Example 1

[0036] like Figure 1 As shown, this embodiment provides a double-layer preheating furnace for polyurethane foaming process, including two furnace bodies arranged independently above and below for simultaneously preheating two workpieces; the upper and lower furnace bodies have the same structure, and the technical solution of this utility model is described below using only one furnace body as an example.

[0037] A metal support 13 is provided at the center of the bottom of the furnace body for placing preheated workpieces. The furnace body is equipped with an upper air duct and a lower air duct. The upper air duct includes multiple upper hot air outlets 16 on the upper surface of the furnace body and upper hot air return inlets 17 on the side. The lower air duct includes multiple lower hot air outlets 19 on the lower surface of the furnace body and lower hot air return inlets 18 on the side. A circulating fan is provided on the side of the furnace body to drive hot air from the upper and lower hot air outlets 16 and 19 towards the central area of ​​the furnace body, and then through the upper and lower hot air return inlets 17 and 18. The furnace body forms a closed-loop circulation system. A furnace temperature sensor 10 is provided on each of the left and right sides of the middle area of ​​the furnace body for real-time detection of the furnace temperature. Non-contact surface temperature sensor 15 and frame temperature sensor 14 are respectively provided on the upper and lower rear parts of the furnace body for real-time detection of the workpiece temperature. The furnace temperature sensor 10, surface temperature sensor 15, frame temperature sensor 14 and the circulating fan are respectively connected to the control module 4. When the detected values ​​of the surface temperature sensor 15 and frame temperature sensor 14 reach the preset upper limit, the control module 4 cuts off the heating power supply.

[0038] In this embodiment, the circulating fan includes an upper circulating fan 2 and a lower circulating fan 3. The upper circulating fan 2 is located at the upper side of the furnace body and is used to control the heat circulation of the upper air duct. The lower circulating fan 3 is located at the lower side of the furnace body and is used to control the heat circulation of the lower air duct.

[0039] In this embodiment, the height of the supporting surface of the metal bracket 13 is adjustable, and it is fixed to the bottom of the furnace body by the positioning guide rail 12.

[0040] In this embodiment, the bottom of the metal bracket 13 is provided with a sliding component that engages with the positioning guide rail 12.

[0041] In this embodiment, a part detection switch 9 is provided at the bottom of the furnace body. The part detection switch 9 is connected to the control module 4. When no part is detected in the furnace, heating is automatically stopped.

[0042] In this embodiment, a transparent and foldable crystal curtain 7 is provided at the opening of the furnace body, and magnetic strips 6 are provided on the edge of the crystal curtain 7 for magnetic attraction with the furnace body to achieve a seal.

[0043] In this embodiment, the crystal curtain 7 is connected to the furnace body via a slide rail 8. A crystal curtain position switch 11 is provided on the end face of the furnace body to detect whether the crystal curtain is closed in place. The crystal curtain position switch 11 is connected to the control module 4. When it is detected that the crystal curtain is not closed in place, the three-color light 1 is triggered to alarm, preventing heat dissipation during the heating process.

[0044] In this embodiment, Foma casters 5 are installed at the bottom of the furnace body to facilitate the movement of the furnace body.

[0045] The following is a brief description of the working process of this embodiment:

[0046] Workpiece loading:

[0047] Place the workpiece on the metal support 13, close the crystal curtain 7, the magnetic strip 6 adsorbs and seals the furnace body, and the crystal curtain position switch 11 detects the sealing status.

[0048] Circulating heating start-up:

[0049] After the workpiece detection switch 9 senses the workpiece, the control module 4 starts the heating tube and the circulating fan; the upper circulating fan drives hot air to blow downward from the upper hot air outlet 16, and the lower circulating fan 3 blows upward from the lower hot air outlet 19, forming a bidirectional heat flow.

[0050] Forced hot air circulation:

[0051] After the hot air converges in the middle area of ​​the furnace body, it is drawn back by the fan through the upper hot air return port 17 and the lower hot air return port 18 on the side.

[0052] Closed-loop airflow: hot air → upper and lower outlets → workpiece area → side return outlet → fan → re-blowing out, achieving uniform temperature distribution.

[0053] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0054] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable way without contradiction. In order to avoid unnecessary repetition, this utility model will not describe the various possible combinations separately.

[0055] Furthermore, various different embodiments of this utility model can be combined in any way, as long as they do not violate the spirit of this utility model, they should also be regarded as the content disclosed by this utility model.

Claims

1. A double deck preheating furnace for polyurethane foaming process, characterized in that, The furnace includes two independently arranged furnace bodies for simultaneously preheating two workpieces; a metal support (13) is provided at the middle of the bottom of the furnace body for placing the preheated workpieces; the furnace body is provided with an upper air duct and a lower air duct, the upper air duct including multiple upper hot air outlets (16) on the upper end face of the furnace body and upper hot air return inlets (17) on the side, and the lower air duct including multiple lower hot air outlets (19) on the lower end face of the furnace body and lower hot air return inlets (18) on the side; a circulating fan is provided on the side of the furnace body to drive hot air from the upper hot air outlets (16) and lower hot air outlets (19) to the middle area of ​​the furnace body, and through the upper hot air return inlets (17). The furnace body is equipped with a closed-loop circulation system, including the hot air return port (18). A furnace temperature sensor (10) is provided on each side of the middle area of ​​the furnace body to detect the furnace temperature in real time. Non-contact surface temperature sensor (15) and frame temperature sensor (14) are provided on the upper and lower parts of the rear of the furnace body to detect the workpiece temperature in real time. The furnace temperature sensor (10), surface temperature sensor (15), frame temperature sensor (14) and circulating fan are connected to the control module (4). When the detected values ​​of the surface temperature sensor (15) and frame temperature sensor (14) reach the preset upper limit, the control module (4) cuts off the heating power supply.

2. A double deck preheating furnace for polyurethane foaming process as claimed in claim 1 wherein, The circulating fan includes an upper circulating fan (2) and a lower circulating fan (3). The upper circulating fan (2) is located at the upper side of the furnace body and is used to control the heat circulation of the upper air duct. The lower circulating fan (3) is located at the lower side of the furnace body and is used to control the heat circulation of the lower air duct.

3. A double deck preheating furnace for polyurethane foaming process as claimed in claim 1 wherein, The height of the support surface of the metal bracket (13) is adjustable and it is fixed to the bottom of the furnace body by the positioning guide rail (12).

4. A double deck preheating furnace for polyurethane foaming process as claimed in claim 3 wherein, The bottom of the metal bracket (13) is provided with a sliding component that engages with the positioning guide rail (12).

5. A double deck preheater furnace for polyurethane foaming process as claimed in claim 1 wherein, The bottom of the furnace body is equipped with a part detection switch (9), which is connected to the control module (4). When no part is detected in the furnace, the heating is automatically stopped.

6. A double deck preheater furnace for polyurethane foaming process as claimed in claim 1 wherein, The furnace body opening is provided with a transparent and foldable crystal curtain (7), and the edge of the crystal curtain (7) is provided with a magnetic strip (6) for magnetic attraction with the furnace body to achieve a seal.

7. A double deck preheating furnace for polyurethane foaming process as claimed in claim 6 wherein, The crystal curtain (7) is connected to the furnace body via a slide rail (8). The furnace body end face is equipped with a crystal curtain position switch (11) to detect whether the crystal curtain is closed in place. The crystal curtain position switch (11) is connected to the control module (4). When the crystal curtain is detected to be not closed in place, the three-color light (1) is triggered to alarm, preventing heat dissipation during the heating process.

8. A double deck preheater furnace for polyurethane foaming process as claimed in claim 1 wherein, The bottom of the furnace body is equipped with Foma casters (5) to facilitate the movement of the furnace body.

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