Insulating panel, vehicle body, use and manufacturing process

Abstract

Insulating panel (2) for a vehicle body with at least one heat-insulating core layer (4) and at least one cover layer (10) made of a fiber-reinforced plastic material (12), characterized in that the core layer (4) has at least in some areas at least one blind-shaped needle hole (8) or at least one groove (6) and at least one blind-shaped needle hole (8), wherein the cover layer (10) engages in the at least one needle hole (6) or in the at least one groove (6) and the at least one needle hole (6) in a form-fitting and / or material-fitting manner.

Description

The invention relates to an insulating panel having the features of the preamble of claim 1. The invention further relates to a vehicle body, a use and a method for manufacturing an insulating panel. In commercial vehicle construction, metal cover plates are typically used to manufacture insulating panels, which are arranged parallel to each other with a gap between them. A liquid is introduced into this gap and foamed to form an insulating layer. The production of foamed insulating panels is complex and expensive, as the foam must displace and fill the air contained in the gap. Furthermore, there are limitations regarding the shape and size of the insulating panels produced in this way. Another option for manufacturing insulating panels is bonded panels, in which prefabricated insulating layers and cover plates are glued together. Here, too, the shape and size of the insulating panels are subject to limitations. An insulating panel of the type mentioned above, with facing layers made of fiber-reinforced plastic materials, is known, for example, from WO 99 / 50 060 A1, which originates from the applicant. Such insulating panels can be manufactured using a wet-on-wet process in which glass fiber mats are impregnated with resin and cured. This process is complex. The production of insulating panels with facing layers made of fiber-reinforced plastic materials is improved by using the so-called SMC process, in which a flowable resin mat with isotropic properties and random fiber distribution in the mat plane is used. The SMC process enables the automated production of the insulating panels. An example of the use of insulated panels in refrigerated vehicles is shown in DE 10 2013 105 819 A1, which originates from the applicant. Such refrigerated vehicles typically include fixtures, such as rail elements, used for load securing or double-deck loading. Connecting these fixtures to insulated panels is problematic because, on the one hand, the fixtures must be mechanically and firmly connected to the insulated panels, and on the other hand, they should have as little impact as possible on the thermal properties of the insulated panels. Furthermore, the automated manufacturing of the insulated panels is made more difficult. Furthermore, the insulating panels of the aforementioned type must meet increasing demands regarding durability and strength. At the same time, however, the manufacturing effort should at least remain the same and preferably be reduced. DE 19 51 310 A describes a composite building panel with a core layer made of a polymer material and a cover layer made of a fiber-reinforced plastic material. The core layer has through-holes through which wicks extend to conduct the resin used for the cover layer from one side of the core layer to the opposite side. These through-holes form a thermal bridge and reduce the thermal insulation capacity of the composite building panel. Further state of the art is represented by EP 1 689 581 B1 , GB 1 173 589 A , GB 1 177 582 A and DE 10 2018 129 602 A1 . The invention is therefore based on the objective of providing an insulating panel for a vehicle body, in particular a refrigerated vehicle body, which can be manufactured easily and has good strength. The invention is further based on the objective of providing a vehicle body, a vehicle, and a manufacturing method for insulating panels. According to the invention, the problem with regard to the insulating panel is solved by the subject matter of claim 1. With regard to the vehicle structure, the problem is solved by the subject matter of dependent claim 7, with regard to the use in a vehicle by the subject matter of dependent claim 8, and with regard to the method for manufacturing an insulating panel by the subject matter of dependent claim 9. Advantageous designs, further developments and variants are the subject of the subclaims. Specifically, the problem is solved by an insulating panel for a vehicle body, in particular a refrigerated vehicle body, comprising at least one heat-insulating core layer and at least one cover layer made of a fiber-reinforced plastic material. The core layer has, at least in some areas, at least one blind pinhole or at least one groove and at least one blind pinhole. Preferably, the core layer has several grooves and / or several pinholes. Furthermore, the cover layer engages positively and / or materially with the at least one blind pinhole or with the at least one groove and the at least one blind pinhole. For this purpose, the cover layer is preferably sprayed onto the core layer and pressed together with it.In other words, by filling at least one groove and / or at least one blind-shaped needle hole, tooth-like formations can develop within the cover layer that engage with the core layer. The term "at least partially" here means that the core layer may also have one or more areas on its surface that are not provided with at least one blind-shaped pinhole or with at least one groove and at least one blind-shaped pinhole. Preferably, however, the core layer has several grooves and / or several blind-shaped pinholes on its entire surface. The advantage here is that air inclusions can escape during spraying and / or pressing through the grooved and / or needled core layer, and any air inclusions remaining after pressing are contained within the at least one blind needle hole or the at least one groove and the at least one needle hole. This advantageously optimizes the complete pressing of the insulating panel. Furthermore, the material-bonded and / or form-fit engagement of the cover layer in the at least one blind needle hole or the at least one groove and the at least one blind needle hole results in a significant increase in strength compared to the insulating panels of the aforementioned prior art. In one embodiment, the at least one blind pinhole, or the at least one groove and the at least one blind pinhole, have a depth between 1 mm and 5 mm. This depth has proven suitable to ensure sufficient engagement of the cover layer with the core layer and to minimize the effort required to create the blind pinhole, or the groove and the at least one blind pinhole, since complex processes such as individually drilling the pinholes are unnecessary. Instead, the pinholes are created, for example, by machining the core layer with a needle roller.The needle roller can be understood as a roller that has needles on its surface which pierce the core layer to form the needle holes - when the needle roller is rolled over the core layer. According to a further embodiment, at least two blind pinholes or the at least one groove and the at least one blind pinhole are arranged in a pattern, at least in certain areas. This is particularly the case when the core layer has several grooves and / or pinholes. "Pattern-like" here means that the grooves and / or the pinholes have a uniform spacing and / or a uniform depth. That is, the at least two blind pinholes or the grooves and the blind pinholes are arranged in a uniform distribution, at least in certain areas, on the surface of the core layer. This is easily achieved by using the aforementioned needle roller.The advantage here is that the aforementioned increase in the strength of the insulating panels is significantly optimized by the patterned arrangement of at least two blind-shaped needle holes or grooves and blind-shaped needle holes, compared to a merely separated or "random" arrangement of blind-shaped needle holes or grooves and blind-shaped needle holes. The fact that the blind-shaped needle holes or the grooves and the blind-shaped needle holes are arranged in a pattern, at least in some areas, is based on the idea that some areas of the core layer and thus also of the insulating panels, as already mentioned, are not provided with the blind-shaped needle holes or grooves and the blind-shaped needle holes because, for example, fastening elements are arranged in these areas. In one embodiment, the cover layer completely fills the at least one blind pinhole or the at least one groove and the at least one blind pinhole. That is, the fiber-reinforced plastic material is preferably completely, form-fittingly, and / or materially bonded within the at least one blind pinhole or the at least one groove and the at least one blind pinhole. This is also preferably achieved by the aforementioned spraying and pressing of the cover layer with the core layer. By completely filling the at least one blind pinhole or the at least one groove and the at least one blind pinhole, the strength of the insulating panel is significantly increased once again.Therefore, due to the increased stability which extends over the entire surface of the insulating panel, almost any point on the insulating panel can be used to attach components. In the insulating panel according to the invention, the outer layer preferably has an outer surface that is flat or smooth, at least in the area of ​​the at least one blind pinhole or the at least one groove and the at least one blind pinhole. This makes it possible to create a flat or smooth structure over the entire surface of the insulating panel, including in the area of ​​the at least one blind pinhole or the at least one groove and the at least one blind pinhole. In this embodiment, areas of the outer layer are formed that are of different thicknesses, but simultaneously create an overall flat and uniform visible surface.For this purpose, the profiling takes place inside the insulating panel by means of the at least one blind-shaped needle hole or the at least one groove and the at least one blind-shaped needle hole formed in the core layer according to the invention. The outer surface of the outer layer is the side of the outer layer facing away from the core layer. Therefore, the outer surface of the outer layer can form either the inside or the outside of the insulating panel. In a refrigerated vehicle body, the inside of the insulating panel defines the interior volume of the cargo space, i.e., the cargo area. The outer surface of the insulating panel forms the visible wall or outer boundary of the body. Preferably, the cover layer outside the at least one blind pinhole or the at least one groove and the at least one blind pinhole has a uniform layer thickness, at least in sections. This creates a uniform sandwich structure of the insulating panel, which is specifically modified in the area of ​​the at least one blind pinhole or the at least one groove and the at least one blind pinhole by the increased layer thickness. The cover layer transitions continuously, i.e., monolithically, from the area of ​​the at least one blind pinhole or the at least one groove and the at least one blind pinhole to the areas outside the at least one blind pinhole or the at least one groove and the at least one blind pinhole. Within the scope of the invention, a vehicle body, in particular a refrigerated vehicle body, with at least one insulating panel according to the invention is further disclosed and claimed. It is possible that the vehicle body is partially or completely constructed from insulating panels according to the invention. The vehicle with an insulating panel according to the invention can, for example, be a refrigerated vehicle, in particular a semi-trailer designed as a refrigerated vehicle (refrigerated trailer). For the production of such insulating panels, reference is made to the manufacturing process described in this application and claimed in claim 9. The inventive method for manufacturing the insulating panel described above comprises the following steps. First, a core layer made of at least one heat-insulating, in particular foamed, material is provided. The core layer is then processed with a tool in such a way that it is provided, at least in certain areas and preferably on its entire surface, with at least one blind-shaped needle hole or at least one groove and with at least one blind-shaped needle hole, preferably with several grooves and / or with several needle holes. The core layer, including at least one blind pinhole or at least one groove and at least one blind pinhole, is sprayed with a fiber-reinforced, in particular glass fiber-reinforced, plastic material, so that a cover layer is formed on the core layer, including the blind pinhole or the groove and at least one blind pinhole. The core layer is pressed together with the cover layer to fill the blind pinhole or the groove and at least one blind pinhole with the fiber-reinforced plastic material and to form a flat or smooth outer surface of the cover layer. The inventive method has the advantage that a particularly strong insulating panel is produced in a relatively short manufacturing time. Spraying the top layer onto the core layer can be carried out robotically, similar to the painting of body parts in automotive manufacturing. The production of the insulating panels is therefore readily automatable. The inventive method is flexible because providing the core layer with at least one blind-shaped pinhole or at least one groove and at least one blind-shaped pinhole, as well as spraying on the fiber-reinforced plastic material, enables the production of insulating panels with complex geometries. For example, reinforcements, ribs, connecting elements, moldings, inserts, and the like can be produced by the sprayed-on plastic material in conjunction with a correspondingly profiled core layer.The process allows for the creation of different areas within one and the same insulating panel, so that the aforementioned local functional areas (e.g. for arranging fastening elements) or at least one local functional area can be manufactured with minimal effort. The insulating panels can be manufactured with high precision. Furthermore, it has been shown that the bond between the outer layer and the core layer is very good due to the at least one blind-shaped pinhole or the at least one groove and at least one blind-shaped pinhole. In addition, the insulating panels produced according to the invention are lighter than known panels with metal outer layers. This advantage is particularly important in commercial vehicle construction. The insulating panels produced using the inventive method are robust, impact-resistant, and exhibit very high strength, thus preventing or at least reducing hail damage, for example. Compared to known manufacturing processes, the manufacturing process according to the invention is cost-effective compared to conventionally manufactured insulating panels with comparable high strength, both in terms of the manufacturing process and material costs. The fiber-reinforced plastic materials used in the process according to the invention exhibit low linear expansion due to temperature differences, which is particularly advantageous in refrigerated vehicle construction. The plastic materials are corrosion-resistant, colorable, electrically non-conductive, acid- and alkali-resistant, and readily machinable. Furthermore, the insulating panels manufactured according to the invention are lightweight and therefore buoyant. The manufacturing process is therefore very flexible and suitable for virtually any type of installation element, or at least for those commonly used in commercial vehicle construction, such as shelf rails or hinge elements for rear doors, or other installation elements. The manufacturing process also allows for the formation of stabilizing elements within the insulated panel, as described in detail elsewhere. Preferably, the steps listed above can be repeated to form a multi-layer insulating panel. The tool is preferably a cutting or forming tool. Specifically, the tool is the aforementioned needle roller, as this allows for particularly simple processing of the core layer. For example, the needle roller is rolled over the core layer to form the needle holes, a process that can also be automated. The advantages and preferred design variants listed with regard to the insulating panels can be applied analogously to the vehicle body, the vehicle and the method, and vice versa. An embodiment of the invention is explained in more detail below with reference to the figures. These show, in a partially highly simplified representation: Fig. 1 a top view of a core layer of an insulating panel according to the invention, and Fig. 2 a partial section through the insulating panel according to the invention with the core layer and a top layer sprayed onto it. In the figures, parts that have the same effect are always represented with the same reference symbols. Figure 1 shows a top view of an insulating panel 2 for a vehicle body, in particular a refrigerated vehicle body. Specifically, Figure 1 shows only a heat-insulating core layer 4 of the insulating panel 2. The core layer 4 has, at least in some areas, at least one blind-shaped needle hole 8 or at least one groove 6 and at least one blind-shaped needle hole 8. In the embodiment according to Fig. 1, the core layer 4 has several, specifically four, grooves 6 distributed across its entire surface, as well as several patterned needle holes 8. In the context of the embodiment according to Fig. 1, "patterned" means that the needle holes 8 are arranged uniformly and, in particular, at a uniform distance from one another. The at least one groove 6 and the at least one needle hole 8 have a depth T (see Fig. 2) with a value in the range of 1 mm to 5 mm. In embodiment 1, all grooves 6 and all needle holes 8 have the same depth T. In the production of the insulating panel 2, the core layer 4 is machined with a preferably clamping tool to form at least one blind-shaped needle hole 8 or at least one groove 6 and at least one needle hole 8. Specifically with regard to the formation of the at least one needle hole 8, the core layer 4 is machined, for example, by means of a needle roller that is rolled over the core layer 4. Figure 2 shows a partial section through the insulating panel 2 according to the invention, with the core layer 4 and a cover layer 10 sprayed onto it. The cover layer 10 engages in a form-fitting and material-bonded manner with the at least one blind-shaped needle hole 8 or the at least one groove 6 and the at least one blind-shaped needle hole 8. This is achieved in particular by pressing the sprayed-on cover layer 10, which comprises or is formed from a fiber-reinforced plastic material 12, with the core layer 4 during the manufacturing process, thus completely and form-fittingly pressing the plastic material 12 into the at least one blind-shaped needle hole 8 or the at least one groove 6 and the at least one blind-shaped needle hole 8.In other words, the plastic material 12 forms teeth that engage in a form-fitting and / or material-locking manner in the at least one blind-shaped needle hole 8 or the at least one groove 6 and in the at least one blind-shaped needle hole 8. In the embodiment shown in Fig. 2, the core layer 4 is completely surrounded by the cover layer 10. For clarity, the insulating panel 2 in the embodiment shown in Fig. 2 is provided with only two grooves 6. However, the insulating panel 2 can also have several blind pinholes 8 or several grooves 6 and several blind pinholes 8 (see Fig. 1). The insulating panel 2 according to Fig. 2, and specifically the cover layer 10, has an outer surface 14 which is flat and / or smooth, at least in the area of ​​the at least one blind pinhole 8 or the at least one groove 6 and the at least one blind pinhole 8. In the embodiment according to Fig. 2, the outer surface 14 of the cover layer 10 is smooth and flat throughout, i.e., completely in all areas. Furthermore, outside of the at least one blind-shaped needle hole 8 or the at least one groove 6 and the at least one blind-shaped needle hole 8, the covering layer 10 has at least a uniform layer thickness D in sections and is in particular monolithic, i.e. formed in one piece. In the illustrated embodiment, the core layer 4 has grooves 6 and pinholes 8. However, it is explicitly pointed out that the invention also relates to insulating panels 2 that have pinholes 8 designed as blind holes. Furthermore, it is possible that insulating panels 2 according to the invention have only grooves 6 on one side and only pinholes 8 on the opposite side. Furthermore, it generally applies to all embodiments of the invention that the grooves 6 can be arranged parallel or at angles to each other, in particular intersecting each other. The needle holes 8 are designed as blind holes, i.e., they terminate within the core layer 4. The invention is not limited to the embodiment described above. Rather, other variants of the invention can also be derived by a person skilled in the art without departing from the subject matter of the invention. In particular, all individual features described in connection with the embodiment can also be combined with one another in other ways without departing from the subject matter of the invention. Reference symbol list 2 Insulating panel 4 Core layer 6 Groove 8 Needle hole 10 Cover layer 12 Plastic material 14 Outer side D Layer thickness T Depth

Claims

Insulating panel (2) for a vehicle body with at least one heat-insulating core layer (4) and at least one cover layer (10) made of a fiber-reinforced plastic material (12), characterized in that the core layer (4) has at least in some areas at least one blind-shaped needle hole (8) or at least one groove (6) and at least one blind-shaped needle hole (8), wherein the cover layer (10) engages in the at least one needle hole (6) or in the at least one groove (6) and the at least one needle hole (6) in a form-fitting and / or material-fitting manner. Insulating panel (2) according to claim 1, characterized in that the at least one needle hole (8) or the at least one groove (6) and the at least one needle hole (8) have a depth (T) with a value in the range of 1mm to 5mm. Insulating panel (2) according to claim 1 or claim 2, characterized by at least two needle holes (8) or by at least one needle hole (8) and at least one groove (6), wherein the at least two needle holes (8) or the at least one needle hole (8) and the at least one groove (6) are arranged in a pattern at least in some areas. Insulating panel (2) according to one of the preceding claims, characterized in that the cover layer (10) completely fills the at least one needle hole (8) or the at least one groove (6) and the at least one needle hole (8). Insulating panel (2) according to one of the preceding claims, characterized in that the cover layer (10) has an outer surface (14) which is flat and / or smooth at least in the area of ​​the at least one needle hole (8) or the at least one groove (6) and the at least one needle hole (8). Insulating panel (2) according to one of the preceding claims, characterized in that the cover layer (10) outside the at least one needle hole (8) or the at least one groove (6) and the at least one needle hole (8) has a uniform layer thickness (D) at least section by section. Vehicle body with at least one insulating panel (2) according to claim 1 . Use of an insulating panel (2) according to claim 1 in a vehicle. Method for manufacturing an insulating panel (2) comprising the following steps: - Providing a core layer (4) made of at least one heat-insulating material; - Machining the core layer (4) with a tool such that the core layer (4) is provided at least in certain areas with at least one blind-shaped needle hole (8) or with at least one groove (6) and at least one blind-shaped needle hole (8); - Spraying the core layer (4) and the at least one needle hole (8) or the at least one groove (6) and the at least one needle hole (8) with a fiber-reinforced plastic material (12) to form a cover layer (10); - Pressing the core layer (4) with the cover layer (10) to fill the at least one needle hole (8) or the at least one groove (6) and the at least one needle hole (8) with the fiber-reinforced plastic material (12) and to form a flat and smooth outer surface (14) of the cover layer (10). Method according to claim 9, characterized in that the heat-insulating material is a foamed material. Method according to claim 9 or 10, characterized in that the fiber-reinforced plastic material (12) is a glass fiber-reinforced plastic material (12). Method according to one of claims 9 to 11, characterized in that the tool is designed as a cutting or forming tool.

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