Self-adaptive pressure adjusting automotive trim flanging forming die

Abstract

The invention discloses a self-adaptive pressure adjusting automobile interior flanging forming die which is characterized in that an upper die part comprises an infrared heating unit and a plurality of pressure adjusting module units; each pressure adjusting module unit comprises a mold insert, an electric cylinder and a control unit; a cylinder body of the electric air cylinder is fixed to the top of the upper die part and electrically connected with the control unit, and a cylinder rod of the electric air cylinder is connected with the die insert and drives the die insert to move up and down to achieve pressure adjustment. The lower die part comprises a plurality of pressure sensors, and each pressure sensor corresponds to the die insert of one pressure adjusting module unit in position and is electrically connected with the control unit of the pressure adjusting module unit. The multi-point pressure sensor is used for monitoring in real time and transmitting monitoring data to the control unit, the control unit adjusts control pressure of the air cylinders in different areas according to preset values, and then pressing force of the upper die part and the lower die part in different areas is adjusted.

Description

Technical Field

[0001] The present invention relates to the technical field of automotive interior product molds, and particularly to an automotive interior flanging and forming mold with adaptive pressure regulation. Background Art

[0002] Automotive interior flanging and forming is one of the key processes in interior part manufacturing, mainly used for the skin covering of components such as door panels, instrument panels, and center consoles. This process uses hot pressing and composite technology to bond the pre-sprayed hot melt adhesive skin material (such as PVC, TPO, genuine leather, etc.) to the plastic skeleton under high temperature and pressure, and complete precise flanging treatment to ensure smooth edges, no wrinkles, and no delamination. The flanging quality directly affects the assembly accuracy, aesthetics, and durability of interior parts, so high requirements are put forward for the mold structure, temperature control, and pressure regulation.

[0003] Currently, the hot pressing and forming process is commonly used in the industry, and its core challenges are as follows:

[0004] 1. Material adaptability: The ductility and shrinkage rate of different skin materials (such as soft PVC and hard TPO) vary greatly, and cracking or springback is likely to occur during flanging.

[0005] 2. Temperature control: The imbalance of the adhesive layer activation temperature, mold temperature, and ambient temperature will lead to insufficient bonding strength or local overheating and deformation.

[0006] 3. Pressure regulation: The pressure of traditional flanging molds is fixed and cannot adapt to the flanging requirements of complex curved surfaces or variable-thickness materials, easily resulting in edge warping, glue overflow, or pressing damage.

[0007] The prior art has made certain optimizations for temperature control and mold structure, but there is still a problem of insufficient flanging pressure regulation. The representative patents are as follows:

[0008] 1. Intelligent temperature control system for hot pressing and composite equipment (CN 119458923 A)

[0009] This patent proposes an intelligent temperature control method based on multivariable feedback. By establishing the functional relationship between the adhesive layer temperature, part surface temperature, mold temperature, ambient temperature, and heating time, precise temperature control is achieved. Its advantage is to reduce the problem of uneven activation of the adhesive layer caused by temperature fluctuations, but it does not involve dynamic pressure regulation during the flanging stage, resulting in uneven pressure distribution at the edges of complex curved surfaces, which affects the flanging quality.

[0010] 2. Cold and hot pressing equipment for automotive instrument panel covering (CN 112519246 A)

[0011] This patent adopts a structural design of double upper molds + single lower mold, and improves the forming efficiency by alternating cold pressing and hot pressing. Although the production rhythm is optimized, the flanging pressure still depends on static setting and cannot be adjusted in real time according to material deformation. Therefore, problems such as insufficient material stretching or excessive compression are likely to occur at the deep cavity structure or acute angle flanging.

[0012] Although the above patents have innovations in temperature control and mold structure, they have not solved the problem of dynamic pressure regulation during the flanging process, specifically manifested as follows:

[0013] Fixed pressure distribution: Traditional molds adopt equal pressure design and cannot adapt to variable curvature flanging, resulting in local stress concentration or insufficient pressure.

[0014] Lack of real-time feedback: Pressure sensors or adaptive adjustment systems are not integrated, making it difficult to cope with deviations caused by material thickness fluctuations or mold wear.

[0015] High flanging defect rate: Edge warping, exposed glue lines or damaged epidermis are likely to occur in complex geometries (such as acute angle flanging, multi-layer composite structures).

[0016] In summary, although the existing technologies have made breakthroughs in temperature control and efficiency, the precise regulation of flanging pressure is still a pain point in the industry. In the future, it is necessary to further improve the forming quality and consistency through intelligent and adaptive mold design. Summary of the Invention

[0017] The purpose of the present invention is to provide an adaptive pressure adjustment automotive interior flanging forming mold, which can monitor and adjust the pressing force of different regions in real time through multiple pressure sensors, and solves the problem that the existing molds have certain cracking defects after flanging due to differences in the skin thickness and material of different batches of materials.

[0018] In order to achieve the above purpose, the present invention provides the following technical solutions:

[0019] An adaptive pressure adjustment automotive interior flanging forming mold, including an upper mold part and a lower mold part, wherein:

[0020] The upper mold part includes an infrared heating unit and a pressure adjustment module unit, and a plurality of pressure adjustment module units are provided; each pressure adjustment module unit includes a mold insert, an electric cylinder and a control unit; the cylinder body of the electric cylinder is fixed on the top of the upper mold part and is electrically connected to the control unit, and the cylinder rod of the electric cylinder is connected to the mold insert and drives the mold insert to move up and down to achieve pressure adjustment;

[0021] The lower mold part includes pressure sensors, and a plurality of pressure sensors are provided. Each pressure sensor corresponds to the position of the mold insert of a pressure adjustment module unit and is electrically connected to the control unit of the pressure adjustment module unit;

[0022] The monitoring data is real-time monitored by a multi-point pressure sensor and transmitted to the control unit, and the control unit adjusts the control pressure of cylinders in different areas according to preset values, thereby adjusting the pressing force of the upper die part and the lower die part in different areas.

[0023] Furthermore, for the above-mentioned adaptive pressure adjustment automotive interior flanging forming die, the control pressure of the cylinder is 0.5 MPa to 3 MPa.

[0024] Furthermore, for the above-mentioned adaptive pressure adjustment automotive interior flanging forming die, the pressure adjustment module unit is set to 20.

[0025] Furthermore, for the above-mentioned adaptive pressure adjustment automotive interior flanging forming die, the lower die part further includes a positioning mechanism to ensure that the alignment tolerance between the part placed in the lower die cavity and the skin material is ≤ 0.5 mm.

[0026] Furthermore, for the above-mentioned adaptive pressure adjustment automotive interior flanging forming die, the wavelength of the infrared heating unit is 2.5 μm to 5 μm.

[0027] Furthermore, for the above-mentioned adaptive pressure adjustment automotive interior flanging forming die, the upper die part further includes a thermocouple for real-time monitoring of the temperature distribution of the infrared heating unit to ensure a temperature control accuracy of ±3°C.

[0028] Furthermore, for the above-mentioned adaptive pressure adjustment automotive interior flanging forming die, the pressure sensor adopts a piezoelectric type or a strain gauge type to collect pressure data of each area in real time, and the sampling frequency is ≥ 100 Hz.

[0029] Furthermore, for the above-mentioned adaptive pressure adjustment automotive interior flanging forming die, the control unit is based on a PLC or an embedded system, and according to the pressure feedback and the preset process curve, adjusts the output of the cylinder through a proportional valve to achieve dynamic compensation in different areas.

[0030] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0031] The adaptive pressure adjustment automotive interior flanging forming die provided by the present invention is a specialized composite processing equipment for automotive interior parts, mainly used for realizing high-precision composite forming of skin materials and skeleton structures. The die realizes an innovative hot pressing composite process through the combination of infrared heating and dynamic pressure compensation, and integrally forms the skin material pre-sprayed with hot melt adhesive and the skeleton in a high-temperature and high-pressure environment, while completing precise flanging processing at the same time.

[0032] Compared with traditional forming processes, this mold structure has significant process advantages: its multi-point pressure sub-region control system can adapt to skin materials of different materials and thicknesses, demonstrating excellent material compatibility; at the same time, the cylinder pressure can be dynamically adjusted to form a unique surface design and flanging angle, which can ensure a neat and smooth transition at the product edge, achieving excellent flanging quality and stable dimensional accuracy.

[0033] With this mold structure, this technical solution has a high tolerance for skin materials, can achieve perfect flanging quality, greatly improves the overall aesthetics and assembly reliability of interior parts, and solves the problem of flanging cracking caused by factors such as single equipment pressure and poor equipment adaptability of skin materials in traditional equipment. This mold can be widely used in the mass production of high-quality interior parts such as car door panels, instrument panels, and center consoles. Brief Description of the Drawings

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required in the embodiments. Obviously, the drawings in the following description are only some embodiments recorded in the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings.

[0035] Figure 1 It is a schematic structural diagram of an adaptive pressure adjustment automotive interior flanging forming mold provided by an embodiment of the present invention.

[0036] Description of the Reference Numerals in the Drawings

[0037] 1. Upper mold part; 2. Lower mold part; 3. Infrared heating unit; 4. Pressure adjustment module unit; 5. Pressure sensor; 6. Part. Detailed Embodiments

[0038] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the following will further introduce the present invention in detail in combination with the drawings and embodiments.

[0039] As Figure 1 shown, an adaptive pressure adjustment automotive interior flanging forming mold provided by the present invention includes an upper mold part 1 and a lower mold part 2, wherein:

[0040] The upper mold part 1 includes an infrared heating unit 3 and a pressure adjustment module unit 4. Specifically, the wavelength of the infrared heating unit 3 is 2.5 μm to 5 μm. In a preferred embodiment, the upper mold part 1 further includes a thermocouple for real-time monitoring of the temperature distribution of the infrared heating unit to ensure a temperature control accuracy of ±3°C.

[0041] For the convenience of zoning control, a plurality of said pressure adjustment module units 4 are provided. In a preferred embodiment, 20 said pressure adjustment module units 4 are provided.

[0042] Each pressure adjustment module 4 unit includes a die insert, an electric cylinder, and a control unit; the cylinder block of the electric cylinder is fixed to the top of the upper die part and electrically connected to the control unit, and the cylinder rod of the electric cylinder is connected to the die insert and drives the die insert to move up and down to achieve pressure adjustment. Specifically, the control pressure of the cylinder is 0.5 MPa to 3 MPa. The control unit is based on a PLC or an embedded system, and according to the pressure feedback and the preset process curve, adjusts the output of the cylinder through a proportional valve to achieve regional dynamic compensation.

[0043] The lower die part 2 includes a pressure sensor 5, and a plurality of said pressure sensors 5 are provided. Each pressure sensor 5 corresponds to the position of the die insert of a pressure adjustment module unit 4 and is electrically connected to the control unit of the pressure adjustment module unit 4; for example, in a preferred embodiment, 20 said pressure adjustment module units are provided, and correspondingly, 20 pressure sensors 5 are also provided. Specifically, the pressure sensor 5 adopts a piezoelectric type or a strain gauge type, and real-time collects the pressure data of each area, and the sampling frequency ≥ 100 Hz.

[0044] The multi-point pressure sensors are used for real-time monitoring and the monitoring data is transmitted to the control unit. The control unit adjusts the control pressure of the cylinders in different areas according to the preset value, and further adjusts the pressing force of the upper die part and the lower die part in different areas.

[0045] Preferably, the lower die part 2 further includes a positioning mechanism to ensure that the alignment tolerance between the part 6 placed in the lower die cavity and the skin material is ≤ 0.5 mm.

[0046] The present invention discloses an adaptive pressure-adjusting flanging forming die for automobile interior trim. This flanging forming process adopts an intelligent control strategy, and through the combination of infrared heating and dynamic pressure compensation, ensures the high-quality composite of the skin and the skeleton. The specific process is as follows:

[0047] 1. Part positioning stage

[0048] The operator precisely places the pre-treated skeleton structure into the positioning mechanism of the lower die cavity to ensure that the alignment tolerance with the skin material is ≤ 0.5 mm.

[0049] The skin material is laid on the surface of the skeleton through a vacuum chuck or a manipulator, and the initial wrinkles are eliminated through a pre-stretching mechanism.

[0050] 2. Die closing and infrared heating stage

[0051] The upper die completes die closing under the drive of the hydraulic system, and the die closing speed can be adjusted in stages to avoid material displacement.

[0052] The infrared heating unit (wavelength 2.5μm - 5μm) integrated in the upper mold radiates directionally to the adhesive layer, raising the temperature of the adhesive layer to the activation range (usually 120 - 180°C) within 10 - 30 seconds. Meanwhile, the temperature distribution is monitored in real time through a thermocouple to ensure a temperature control accuracy of ±3°C.

[0053] 3. Dynamic pressure regulation stage

[0054] Multi-point pressure sensors (such as piezoelectric or strain gauge type) distributed in the lower mold collect pressure data in each area in real time, with a sampling frequency ≥100Hz.

[0055] The control module (based on PLC or embedded system) adjusts the output of the cylinder through a proportional valve according to the pressure feedback and the preset process curve, driving the mold insert to move up or down to achieve regional dynamic pressure compensation. For example:

[0056] Maintain a constant pressure (usually 0.5 - 1.2MPa) in the flat area;

[0057] Increase the local pressure by 20% - 30% in the flanging acute angle area to inhibit springback;

[0058] Automatically reduce the pressure in the material weak area (such as the leather seam) to prevent crushing.

[0059] 4. Pressure holding and cooling and shaping

[0060] Maintain for 10 - 15 seconds under the optimized pressure to allow the adhesive layer to flow and penetrate fully.

[0061] The water cooling channel is started and cooled to below 60°C at a rate of 5 - 8°C / s. After ensuring dimensional stability, the mold is opened.

[0062] Compared with the prior art, the technical advantages of the present invention are as follows:

[0063] 1. Precise temperature control and efficient activation

[0064] The infrared heating has a 40% higher conduction efficiency compared with the traditional hot plate, and reduces the risk of skin thermal damage by matching the narrowband spectrum with the absorption characteristics of the adhesive layer.

[0065] 2. Adaptive pressure compensation

[0066] The pressure adjustment module unit can cope with the following complex working conditions:

[0067] Material thickness fluctuations (such as ±0.2mm);

[0068] Surface deviation caused by mold wear;

[0069] Differential deformation of multi-layer composite materials (such as PVC + foam + ABS).

[0070] 3. Defect suppression effect

[0071] Compared with the traditional constant pressure mode, the adaptive pressure regulating flanging forming die for automobile interior trim of the present invention can reduce more than 80% of the edge warping and 50% of the exposed defect of the glue line, and the flanging angle tolerance is controlled within ±0.5°.

[0072] The adaptive pressure regulating flanging forming die for automobile interior trim of the present invention can be applied to the following scenarios:

[0073] 1. Flanging of deep cavity door panels: Dynamically compensate for insufficient material stretching by adding lateral auxiliary pressing blocks.

[0074] 2. Wrapping of sharp corners of instrument panels: Adopt high-frequency pressure fine-tuning (±0.05 MPa) to avoid virtual adhesion at sharp corners.

[0075] 3. Forming of special-shaped center consoles: Combine 3D scan feedback to optimize the pressure distribution curve in real time..

[0076] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features, but these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An adaptive pressure-adjustable automobile interior trim flanging forming die, comprising an upper die portion and a lower die portion, characterized in that: The upper mold part includes an infrared heating unit and a pressure adjustment module unit, and the pressure adjustment module unit is provided in plurality; each pressure adjustment module unit includes a mold insert, an electric cylinder and a control unit; the cylinder body of the electric cylinder is fixed on the top of the upper mold part and is electrically connected to the control unit, and the cylinder rod of the electric cylinder is connected to the mold insert and drives the mold insert to move up and down to achieve pressure adjustment; The lower mold part includes a pressure sensor, and the pressure sensor is arranged in plurality, each pressure sensor corresponds to a mold insert position of a pressure adjustment module unit and is electrically connected to a control unit of the pressure adjustment module unit; Real-time monitoring is performed through multi-point pressure sensors and the monitoring data is transmitted to the control unit. The control unit adjusts the control pressure of the cylinders in different areas according to the preset value, thereby adjusting the pressing force of the upper and lower mold parts in different areas.

2. The self-adaptive pressure regulating automobile interior trim flanging forming die according to claim 1, characterized in that: The control pressure of the cylinder is between 0.5MPa and 3MPa.

3. The self-adaptive pressure regulating automobile interior trim flanging forming die according to claim 1, characterized in that: The number of the pressure adjustment module units is set to 20.

4. The self-adaptive pressure regulating automobile interior trim flanging forming die according to claim 1, characterized in that: The lower die part also includes a positioning mechanism to ensure that the alignment tolerance between the part and the surface material is ≤0.5mm after the part is placed in the lower die cavity.

5. The self-adaptive pressure regulating automobile interior trim flanging forming die according to claim 1, characterized in that: The wavelength of the infrared heating unit is 2.5 μm to 5 μm.

6. The self-adaptive pressure regulating automobile interior trim flanging forming die according to claim 1, characterized in that: The upper mold part also includes a thermocouple for real-time monitoring of the temperature distribution of the infrared heating unit to ensure a temperature control accuracy of ±3°C.

7. The self-adaptive pressure regulating automobile interior trim flanging forming die according to claim 1, characterized in that: The pressure sensor adopts piezoelectric or strain gauge type to collect pressure data of each area in real time, and the sampling frequency is ≥100Hz.

8. The self-adaptive pressure regulating automobile interior trim flanging forming die according to claim 1, characterized in that: The control unit is based on a PLC or an embedded system, and according to pressure feedback and a preset process curve, adjusts the cylinder output through a proportional valve to achieve dynamic compensation in different regions.

Images