Pultrusion floating core mold and composite molding machine

Abstract

The present invention relates to a pultrusion floating core mold and a composite molding machine, including a mold body, etc. The axis of the core is parallel to the axis of the mold body, and the core is arranged through the mold body. The first end of the core is fixed by a core fixing mechanism. The floating core mold also includes a core suspension mechanism, which is arranged on the end of the mold body corresponding to the core to suspend the second end of the core. The radial cross-section of the core is rectangular, and the end of the second end of the core is provided with four first magnets. The core suspension mechanism includes: four second magnets, which are arranged in a first mounting seat, and the four first magnets correspond to each other one by one. The acting force between each second magnet and the corresponding first magnet is a repulsive magnetic force. The core suspension mechanism also includes a second magnet and a corresponding first magnet arranged relative to each other. Compared with the prior art, the present invention can solve the problem of uneven pultrusion resistance without changing the pultrusion process.

Description

Technical Field

[0001] The invention relates to the field of composite material pultrusion molding technology, in particular to a pultrusion molding floating core mold and a composite molding machine. Background Art

[0002] For some composite materials with hollow cavities, since the hollow cavity runs through both ends of the product along the axial direction of the product, unlike some aluminum alloy profile products, such composite products are usually formed by pultrusion. Specifically, one end of the mold core is fixed and the other end is suspended. After forming, the mold core is pulled out from the fixed end. Generally, since the overall radial cross-section of such composite products is very small, the radial cross-sectional area of ​​the hollow cavity is even smaller, and the weight of the mold core itself is small, if the product precision requirements are not very high, it can also meet the requirements.

[0003] However, some products are very long. This results in that, although the weight of the mold core is not very large, the force arm is too long due to the increase in length. At this time, the torque generated by gravity becomes larger. Based on this, the suspended end of the mold core will still have a relatively obvious droop. Or, some products have high quality control requirements, requiring that the hollow cavity in the product must be more parallel to the product axis. At this time, the length of the product is not particularly long, and there is also the problem of too large an angle between the molded hollow cavity and the axis of the product, resulting in the inability to guarantee the straightness of the mold core, and the uneven wall thickness and extrusion resistance of the profile. In order to solve this problem, technical personnel in this field usually frequently adjust the posture of the suspended end of the mold core during the molding process, but this method will affect the stability of production.

[0004] In this regard, some existing technologies that can be referenced provide ways to suspend the mold core. For example, Chinese patent CN111923295A discloses an electromagnetic device and method for eliminating bending deformation of a cylindrical core mold with a large aspect ratio, which belongs to the field of core mold manufacturing technology: the device includes: a core mold body, an electromagnet inside the mold, a tension electromagnet, a buoyancy electromagnet and a straightness sensor. The electromagnet inside the mold is placed inside the core mold body, and the outer wall of the middle part of the core mold body becomes a magnetic pole. Under the action of the attraction of the tension electromagnet directly above the core mold body and the repulsion of the buoyancy electromagnet directly below the core mold body, the electromagnet adjusts the magnetic field force in real time under the guidance of the detection signal of the straightness sensor, and adaptively corrects the bending deformation of the cylindrical core mold with a large aspect ratio. Even if the material wrapped and covered during production increases the weight of the core mold, no excess deformation will occur, thereby maximizing the accuracy of the core mold, thereby improving the quality and precision of the product.

[0005] However, the above device is not suitable for the pultrusion process of composite materials. Specifically, it is necessary to fix the core at both ends of the core and set an electromagnet in the center of the core to suspend the model. On the one hand, since both ends of the core are fixed, pultrusion cannot be performed, that is, the core cannot be pulled out from one end, which requires a complete change in the production process, resulting in a significant decrease in production efficiency. Technical personnel in this field would rather make frequent adjustments than give up the pultrusion process. On the other hand, the electromagnetic suspension method it adopts requires the magnet inside the core to rotate. This method is only applicable to round cores, not square cores, and the overall weight of the composite core is relatively small. It adopts a method of attracting on one side and repelling on the other side. If the overall weight of the core is too small, it is extremely difficult to control the force balance of the core, that is, it is almost impossible to adjust the magnetic field force through electrical signals so that the sum of the upper and lower magnetic field forces is equal to gravity. Summary of the invention

[0006] The purpose of the present invention is to provide a pultrusion floating core mold and a composite molding machine. Compared with the existing single-sided fixing method, it can solve the problem of frequent adjustment without changing the pultrusion process, and can solve the problem of low uniformity of pultrusion resistance, thereby ensuring production efficiency while improving the product yield.

[0007] The purpose of the present invention can be achieved by the following technical solutions:

[0008] A pultrusion floating core mold, comprising a mold body, a mold core and a mold core fixing mechanism, wherein the axis of the mold core is parallel to the axis of the mold body, and the mold core is arranged through the mold body, the first end of the mold core is fixed by the mold core fixing mechanism, and the floating core mold further comprises a mold core suspension mechanism, which is arranged at one end of the mold body corresponding to the mold core to suspend the second end of the mold core;

[0009] The radial cross section of the mold core is rectangular, and four first magnets are provided at the end of the second end of the mold core, wherein two first magnets are symmetrically arranged relative to a vertical plane passing through the axis of the mold core, and the other two first magnets are symmetrically arranged relative to a horizontal plane passing through the axis of the mold core, and the mold core suspension mechanism includes:

[0010] a first mounting seat;

[0011] The four second magnets are all electromagnets and are arranged in the first mounting seat. The four first magnets correspond to each other one by one, and the acting force between each second magnet and the corresponding first magnet is a repulsive magnetic force.

[0012] The core suspension mechanism also includes a second magnet and a corresponding first magnet which are arranged opposite to each other.

[0013] The first magnet is an electromagnet.

[0014] The first mounting seat is cylindrical, and a first channel is provided in the first mounting seat. The axis of the first channel is parallel to the axis of the mold core, and the second end of the mold core is located in the first channel.

[0015] The radial cross section of the first channel is in the shape of an octagon.

[0016] A heat insulation pad is provided between the first mounting seat and the mold body.

[0017] The core fixing mechanism includes a plurality of extended fixing bars and a plurality of fixing plates, wherein the extended fixing bars are parallel to the axis of the mold body, and the projection line segments on the axis of the mold body partially overlap with the projection line segments on the axis of the mold body, all fixing plates are arranged along the axis of the mold body and fixed to the extended fixing bars, the projection areas of all fixing plates on the axis of the mold body do not overlap with the projection line segments on the axis of the mold body, and the first end of the core passes through each fixing plate in turn and is fixed to each fixing plate.

[0018] All fixing plates are arranged in parallel.

[0019] The floating core mold also includes a controller, which is connected to each second magnet and is used to adjust the current of each second electromagnet.

[0020] A first container is also provided in the center of the mold core. The first container is arranged along the axis of the mold core and extends to both ends of the mold core. The first container is sealed by a transparent sealing plate and is filled with liquid, and the volume of the filled liquid is 40% to 60% of the volume of the first container.

[0021] A composite molding machine comprises the floating core mold as described above.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1. Compared with the existing unilateral fixing method, it can solve the problem of frequent adjustment without changing the pultrusion process, and can solve the problem of low uniformity of pultrusion resistance, thereby improving the product yield while ensuring production efficiency.

[0024] 2. The electromagnet method is adopted, which is not affected by temperature changes and maintains stability.

[0025] 3. All corresponding forces of the first magnet and the second magnet are repulsive forces. Therefore, when the weight of the mold core is too small, the control accuracy of the electromagnetic force can be improved by enlarging the scale of the current, thereby achieving suspension control of the small mass mold core.

[0026] 4. A heat insulating pad is provided between the first mounting seat and the mold body, thereby achieving heat insulation. In the solution where part of the first magnet is a permanent magnet, the durability of the first magnet can also be improved.

[0027] 5. By setting the first cavity, it is possible to judge whether the two ends of the mold core are flush by the liquid level inside, thereby avoiding the phenomenon that the electronic sensor is easily disturbed by the magnetic field. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a structural schematic diagram of the present invention;

[0029] Figure 2 is a schematic diagram of one end of the suspension;

[0030] Figure 3 This is a schematic diagram when there is no power;

[0031] Figure 4 This is a schematic diagram when power is turned on;

[0032] Among them: 1. thermal insulation pad, 2. first mounting seat, 3. second magnet, 4. first magnet, 5. mold core, 6. controller, 7. mold body, 8. mold core fixing mechanism, 8-1. extension fixation, 8-2. fixing plate. DETAILED DESCRIPTION

[0033] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0034] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0035] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and 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 cannot be understood as limiting the present invention. In addition, the terms "proximal", "distal", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance. Physical quantities in formulas, if not separately marked, should be understood as basic quantities of the base units of the International System of Units, or derived quantities derived from the basic quantities through mathematical operations such as multiplication, division, differentiation or integration.

[0036] In addition, the terms "horizontal", "vertical", "overhanging" and the like do not mean that the components are required to be absolutely horizontal or overhanging, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0037] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0038] In conjunction with the accompanying drawings, some embodiments of the present invention are described in detail below. In the absence of conflict, the following embodiments and features in the embodiments may be combined with each other.

[0039] A pultrusion floating core mold, such as Figure 1 and Figure 2 As shown, it includes a mold body 7, a mold core 5 and a mold core fixing mechanism 8, the axis of the mold core 5 is parallel to the axis of the mold body 7, and the mold core 5 is arranged through the mold body 7, the first end of the mold core 5 is fixed by the mold core fixing mechanism 8, and the floating core mold also includes a mold core suspension mechanism, which is arranged on one end of the mold body 7 corresponding to the mold core 5 to suspend the second end of the mold core 5;

[0040] The radial cross section of the mold core 5 is rectangular. Four first magnets 4 are provided at the end of the second end of the mold core 5, two of which are symmetrically arranged relative to a vertical plane passing through the axis of the mold core 5, and the other two first magnets 4 are symmetrically arranged relative to a horizontal plane passing through the axis of the mold core 5. The mold core suspension mechanism includes:

[0041] First mounting seat 2;

[0042] The four second magnets 3 are all electromagnets and are arranged in the first mounting seat 2 . The four first magnets 4 correspond to each other one by one. The acting force between each second magnet 3 and the corresponding first magnet 4 is a repulsive magnetic force.

[0043] As set above, compared with the existing unilateral fixing method, the problem of frequent adjustment can be solved without changing the pultrusion process, and the problem of low uniformity of pultrusion resistance can be solved, thereby improving the yield rate of products while ensuring production efficiency. Although some prior arts also disclose magnetic methods to suspend the mold core 5, these prior arts require changing the pultrusion process, which is not worth the loss, and the problem they solve is not to solve the problem of inconsistent uniformity of pultrusion resistance.

[0044] In addition, another important setting is that the forces acting on all corresponding first magnets and second magnets are repulsive forces, so that when the weight of the mold core 5 is too small, the control accuracy of the electromagnetic force can be improved by enlarging the scale of the current, thereby achieving suspension control of the small mass mold core 5.

[0045] For small-mass models, the electromagnetic force configuration scheme used in the prior art is to adsorb from above and repel from below. This scheme cannot be adjusted to a state where the mold core is suspended when facing a small-mass mold core. In the present application, by configuring both as repulsive forces, the second magnet 3 can operate in a larger current range. At this time, due to the larger current range, the relative error of the unit current is reduced while the absolute current control error remains unchanged, thereby improving the control accuracy.

[0046] Generally, the core suspension mechanism further includes a second magnet 3 and a corresponding first magnet 4 which are arranged opposite to each other.

[0047] In some embodiments, the first magnet 4 is an electromagnet, thereby preventing ordinary magnets from being demagnetized due to temperature changes.

[0048] In addition, the first mounting seat 2 is cylindrical, and a first channel is provided in the first mounting seat 2, the axis of the first channel is parallel to the axis of the mold core 5, and the second end of the mold core 5 is located in the first channel. The radial cross section of the first channel is octagonal, which can save space.

[0049] In addition, a heat insulating pad 1 is provided between the first mounting seat 2 and the mold body 7, so as to achieve heat insulation. In the solution where a part of the first magnet is a permanent magnet, the durability of the first magnet can also be improved.

[0050] like Figure 1As shown, in this embodiment, the mold core fixing mechanism 8 includes a plurality of extended fixing bars 8-1 and a plurality of fixing plates 8-2, the extended fixing bar 8-1 is parallel to the axis of the mold body 7, and the projection line segment on the axis of the mold body 7 partially overlaps with the projection line segment on the axis of the mold body 7, all the fixing plates 8-2 are arranged along the axis of the mold body 7 and fixed to the extended fixing bar 8-1, the projection area of ​​all the fixing plates 8-2 on the axis of the mold body 7 does not overlap with the projection line segment on the axis of the mold body 7, and the first end of the mold core 5 passes through each fixing plate 8-2 in sequence and is fixed on each fixing plate 8-2. And all the fixing plates 8-2 are arranged in parallel.

[0051] Generally, the floating core mold further includes a controller, which is connected to each second magnet 3 and is used to adjust the current of each second electromagnet, thereby adjusting the magnitude of the electromagnetic force.

[0052] In some embodiments, a first container is further provided in the center of the core 5. The first container is arranged along the axis of the core 5 and extends to both ends of the core 5. The first container is sealed by a transparent sealing plate, and the first container is filled with liquid. The volume of the filled liquid is 40% to 60% of the volume of the first container. By setting the first cavity, it is possible to judge whether the two ends of the core 5 are flush by the liquid level inside, thereby avoiding the phenomenon that the electronic sensor is easily disturbed by the magnetic field.

[0053] Another aspect of the present application provides a composite molding machine, comprising the above-mentioned floating center mold.

[0054] like Figure 3 and Figure 4 As shown, the suspension of the second section of the mold core is achieved by energizing. Since the overall mass of the mold core is small, the middle part of the mold core does not sag after suspension.

Claims

1. A pultrusion floating core mold, comprising a mold body (7), a mold core (5) and a mold core fixing mechanism (8), wherein the axis of the mold core (5) is parallel to the axis of the mold body (7), and the mold core (5) passes through the mold body (7), and the first end of the mold core (5) is fixed by the mold core fixing mechanism (8), characterized in that: The floating core mold further comprises a core suspension mechanism, which is arranged on an end of the mold body (7) corresponding to the core (5) so as to suspend the second end of the core (5); The radial cross section of the mold core (5) is rectangular. Four first magnets (4) are provided at the end of the second end of the mold core (5), two of which are symmetrically arranged relative to a vertical plane passing through the axis of the mold core (5), and the other two first magnets (4) are symmetrically arranged relative to a horizontal plane passing through the axis of the mold core (5). The mold core suspension mechanism comprises: A first mounting seat (2); The four second magnets (3) are all electromagnets and are arranged in the first mounting seat (2). The four first magnets (4) correspond to each other one by one. The acting force between each second magnet (3) and the corresponding first magnet (4) is a repulsive magnetic force.

2. A pultrusion floating core mold according to claim 1, characterized in that: The core suspension mechanism further comprises a second magnet (3) and a corresponding first magnet (4) arranged opposite to each other.

3. A pultrusion floating core mold according to claim 1, characterized in that: The first magnet (4) is an electromagnet.

4. The pultrusion floating core mold according to claim 1, characterized in that: The first mounting seat (2) is cylindrical, and a first channel is provided in the first mounting seat (2), the axis of the first channel is parallel to the axis of the mold core (5), and the second end of the mold core (5) is located in the first channel.

5. A pultrusion floating core mold according to claim 4, characterized in that: The radial cross section of the first channel is in the shape of an octagon.

6. The pultrusion floating core mold according to claim 1, characterized in that: A heat insulation pad (1) is provided between the first mounting seat (2) and the mold body (7).

7. The pultrusion floating core mold according to claim 1, characterized in that: The mold core fixing mechanism (8) comprises a plurality of extended fixing bars (8-1) and a plurality of fixing plates (8-2), wherein the extended fixing bar (8-1) is parallel to the axis of the mold body (7), and a projection line segment on the axis of the mold body (7) partially overlaps with a projection line segment of the mold body (7) on its own axis, and all fixing plates (8-2) are arranged along the axis of the mold body (7) and fixed to the extended fixing bar (8-1), and a projection area of ​​all fixing plates (8-2) on the axis of the mold body (7) does not overlap with a projection line segment of the mold body (7) on its own axis, and the first end of the mold core (5) passes through each fixing plate (8-2) in sequence and is fixed to each fixing plate (8-2).

8. The pultrusion floating core mold according to claim 7, characterized in that: All the fixing plates (8-2) are arranged in parallel.

9. The pultrusion floating core mold according to claim 1, characterized in that: A first container is also provided in the center of the mold core (5). The first container is arranged along the axis of the mold core (5) and extends to both ends of the mold core (5). The first container is sealed by a transparent sealing plate and is filled with liquid. The volume of the filled liquid is 40% to 60% of the volume of the first container.

10. A composite molding machine, characterized in that: It comprises a floating core mold as described in any one of claims 1-9.

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