Tank entry model

Abstract

To improve mold thickness accuracy of a slush molding die by suppressing deformation of an inlet tank model during electroforming in the inlet tank model for manufacturing a slush molding die by energization in an electrolytic solution.SOLUTION: A resin-made inlet tank model 1 is used to manufacture a slush molding die 10 by laminating an electrodeposited layer made of nickel adhered to a model molding surface 1a side by energization in an electrolytic solution in which nickel ions are dissolved. The inlet tank model has a three-layer structure in which a glass cloth 7 is sandwiched between a resin layer 3 and a resin layer 5 in a thickness direction, and a reinforcement beam 9 is provided on a side opposite to the model molding surface 1a side to increase rigidity.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an immersion model for manufacturing slush molding dies by laminating an electrodeposited layer made of metal that adheres to the molding surface of the model by passing an electric current through an electrolyte solution in which metal ions are dissolved. [Background technology]

[0002] Many vehicle interior panels, such as instrument panels, are made of a multi-layered resin material. For example, there are known interior panels in which the bottom layer is made of a hard core material manufactured by injection molding and the top layer (surface layer) is made of a highly tactile skin material (so-called slash skin).

[0003] Such slush skins are generally formed by a powder slush molding method in which a powdered resin material is melted and adhered to the inner surface of a heated slush molding die to form a resin layer, which is then cooled together with the slush molding die to harden the resin layer, which is then removed from the slush molding die.

[0004] Thus, the slush molding die used in the powder slush molding method is generally manufactured using a resin-made tank model having a model molding surface that faithfully reproduces the shape and surface pattern of the slush skin. More specifically, the tank model is placed in an electrolyte in which metal ions are dissolved, and electricity is passed through the metal as the anode and the tank model as the cathode, so that the metal is deposited on the model molding surface of the tank model to form an electrodeposition layer (hereinafter also referred to as "electrodeposition"). This type of electrodeposition is repeated multiple times (N times) (however, from the second time onwards, metal is deposited on the surface of the electrodeposition layer) to stack the electrodeposition layers, and the metal wall thickness is grown to a predetermined thickness, and then the die thickness is adjusted to manufacture the slush molding die (hereinafter also referred to as "electroforming") (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2021-030532 Summary of the Invention [Problem to be solved by the invention]

[0006] In order to improve the quality of the slush skin, particularly its thickness accuracy, it is necessary to melt and adhere the powdered resin material substantially uniformly to the inner surface of the heated slush molding die. To melt and adhere the powdered resin material substantially uniformly, it is required that the temperature of the heated slush molding die is substantially uniform, in other words, that the die thickness of the slush molding die is substantially uniform.

[0007] Therefore, in order to improve the die thickness accuracy of a slush forming die and at the same time shorten the manufacturing lead time, it is conceivable to adjust the die thickness of a slush forming die after completion of N electrodepositions by using NC (numerical control machining), in which the movement of the cutting tool's cutting edge is defined by coordinate values ​​and the tool is operated by a servo motor driven based on those coordinate values ​​to perform machining. Note that such NC machining is based on the premise that the workpiece is manufactured to a certain extent according to the design.

[0008] However, the resin tank model deforms due to stresses generated during electroforming, and the electrodeposited layer attached to the model molding surface also deforms accordingly. Therefore, simply repeating electrodeposition multiple times to stack the electrodeposited layers makes it difficult to manufacture a slush molding die with the desired (designed) mold thickness, and does not support the application of NC machining.

[0009] For this reason, the current situation is that after each electrochemical deposition, the mold thickness is adjusted manually, for example using a sander, and this task is repeated multiple times (N times), which causes the mold thickness adjustment to take an enormous amount of time.

[0010] Here, in order to suppress deformation of the tank model due to stress during electroforming, it is possible to increase the thickness of the tank model to increase its rigidity, but increasing the thickness of the tank model also increases the amount of resin, which generates a relatively large amount of heat during the curing reaction, and the tank model may sink due to shrinkage and deformation caused by the heat. In particular, if sink marks occur on the model molding surface corresponding to the design surface of the slush molding die, there is a problem that the tank model must be remade from scratch. In addition, it is possible to change the material of the tank model to a resin material that is less likely to deform, but if you want to choose a resin material that is even more difficult to deform from among those that do not react to the electrolyte, the range of choices is extremely narrow, so it is not easy to change the resin material.

[0011] The present invention has been made in consideration of the above-mentioned points, and an object of the present invention is to provide a technique for improving the mold thickness accuracy of a slush casting mold by suppressing deformation of an entry model during electroforming, in a tank model for manufacturing a slush casting mold by passing a current through an electrolyte. [Means for solving the problem]

[0012] In order to achieve the above object, in the bath immersion model according to the present invention, the resin bath immersion model is reinforced from the inside and outside without increasing the thickness of the bath immersion model.

[0013] Specifically, the present invention is directed to a resin tank-entering model for producing a slush molding die by laminating an electrodeposited layer of metal that adheres to the molding surface of the model through the passage of an electric current in an electrolyte solution in which metal ions are dissolved.

[0014] This tank model has a three-layer structure in which glass cloth is sandwiched between resin layers in the thickness direction, and a reinforcing beam is provided on the side opposite to the model molding surface to increase rigidity. The tank model has a recessed portion on a surface opposite to the model molding surface side, the recessed portion being recessed to form a space open to one side, the recessed portion including a first extending portion extending along one direction, a second extending portion extending from an edge of the first extending portion in a direction intersecting the extending direction of the first extending portion, and a third extending portion extending from an edge of the second extending portion in a direction intersecting the extending direction of the second extending portion and facing the first extending portion, and the reinforcing beam is a first extending portion and a second extending portion. a first beam connected to a first corner portion which is a boundary portion between the upper recess component and the upper recessed portion; a second beam connected to the second corner portion which is a boundary portion between the second extension component and the third extension component; a third beam connected to a first edge portion which is an edge on the open side of the first extension component; and a fourth beam connected to a second edge portion which is an edge on the open side of the third extension component, each of the first beam to the fourth beam being disposed with a space between them and each of the first beam to the fourth beam being connected to each other at a center of a space inside the upper recess component. It is characterized by the above.

[0015] According to this configuration, by adopting a three-layer structure in which glass cloth, which contributes to improving rigidity without generating heat, is sandwiched between resin layers in the thickness direction, the resin tank model can be reinforced from the inside without increasing the thickness of the tank model, thereby suppressing deformation of the tank model during electroforming.

[0016] Furthermore, since the tank-entering model has a reinforcing beam on the side opposite the model molding surface to increase rigidity, the resin tank-entering model can be reinforced from the outside without interfering with the adhesion of metal to the model molding surface, i.e., the formation of the electrochemical layer, thereby further suppressing deformation of the tank-entering model during electroforming.

[0017] The combined effect of these features is to reliably suppress deformation of the model entering the tank during electroforming, and accordingly, to suppress deformation of the electrodeposition layer laminated on the model molding surface side, enabling the desired mold thickness to be achieved for the slush molding mold.

[0018] Then, after electrodeposition is completed and the slush molding die has achieved the targeted die thickness, the die thickness precision of the slush molding die can be improved by adjusting the die thickness through NC machining, thereby improving the quality (particularly the thickness precision) of the slush skin.

[0019] Furthermore, the mold thickness of the slush molding mold is adjusted by NC machining after electrodeposition is completed. In other words, the work of manually adjusting the mold thickness after each electrodeposition is eliminated, making it possible to significantly shorten the production lead time. Effect of the Invention

[0020] As described above, according to the tank entry model of the present invention, deformation of the tank entry model during electroforming can be suppressed, and the mold thickness accuracy of the slush molding die can be improved. [Brief description of the drawings]

[0021] [Figure 1]FIG. 2 is a cross-sectional view showing a schematic diagram of a tank entry model according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a cross-sectional view illustrating a schematic diagram of an instrument panel. [Diagram 3] FIG. 2 is a diagram for explaining a powder slush molding method. [Figure 4] FIG. 2 is a diagram showing a schematic state during electroforming. [Diagram 5] FIG. 1 is a diagram for explaining a schematic diagram of the adjustment of the mold thickness of a slush molding die by NC machining. [Figure 6] FIG. 1 is a graph showing a schematic diagram of variation in mold temperature of a slush molding mold during heating. [Figure 7] FIG. 1 is a diagram showing a schematic diagram of a manufacturing process for a slush molding die, in which (a) shows a case where the tank entry model of this embodiment is used, and (b) shows a case where a conventional tank entry model is used. [Figure 8] FIG. 1 is a graph showing a schematic breakdown of the lead time for adjusting the mold thickness of a slush molding mold. [Figure 9] FIG. 1 is a diagram showing a conventional tank immersion model, in which (a) is a cross-sectional view and (b) is a diagram showing a schematic state during electroforming. [Figure 10] FIG. 1 is a diagram for explaining a schematic diagram of the adjustment of the mold thickness of a slush molding die by NC machining. [Figure 11] FIG. 13 is a diagram for explaining a schematic diagram of a problem that occurs when the thickness of the tank model is increased. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0023] Fig. 1 is a diagram that shows a schematic diagram of a tank model 1 according to this embodiment, and Fig. 2 is a cross-sectional diagram that shows a schematic diagram of an instrument panel 30. This tank model 1 is used to manufacture a slush molding die 10 for molding a slush skin 35 that is a skin material of the instrument panel 30, and includes resin layers 3 and 5, a glass cloth 7, and a reinforcing beam 9, as shown in Fig. 1.

[0024] More specifically, many vehicle interior panels such as instrument panel 30 have a multi-layer structure in which the bottom layer is made of a hard base material 31 manufactured by injection molding, the middle layer is made of urethane foam 33, and the top layer (surface layer) is made of a highly tactile slush skin 35, as shown in Fig. 2. Therefore, the texture and feel of instrument panel 30 depend on the quality of the top layer, slush skin 35. Such slush skin 35 is generally molded by a powder slush molding method.

[0025] Fig. 3 is a diagram for explaining the powder slush molding method. In the powder slush molding method, first, as shown by the black arrow in Fig. 3(a), hot air is blown onto the slush molding die 10 to heat it. Next, as shown in Fig. 3(b), the flange portion 10b of the slush molding die 10 is mated with the flange portion 20a of the resin box 20 in which the powder resin material 40 such as polyvinyl chloride resin is accommodated, and then the slush molding die 10 and the resin box 20 are turned upside down and swung, so that the powder resin material 40 is melted and adhered to the inner surface 10a of the heated slush molding die 10 to form a resin layer 41.

[0026] Next, as shown in Figure 3(c), the outer surface 10c of the slush molding die 10 on which the resin layer 41 has not been molded is immersed in water stored in a cooling tank 21, and the resin layer 41 is cooled and hardened together with the slush molding die 10. Then, as shown in Figure 3(d), an operator manually removes the slush skin 35 (hardened resin layer 41) from the inner surface 10a of the slush molding die 10, completing the molding of the slush skin 35.

[0027] The slush molding die 10 used in this powder slush molding method is manufactured as follows, using a resin tank model 1 having a model molding surface 1a that faithfully reproduces the shape and surface pattern of the slush skin 35.

[0028] FIG. 4 is a diagram showing a schematic state during electroforming. In FIG. 4, the glass cloth 7 and the reinforcing beams 9 are omitted for ease of viewing. When manufacturing the slush molding die 10 by electroforming, first, the tank model 1 is placed in the electrolytic solution 25 in which nickel ions (metal ions) are dissolved and contained in the tank body 23. Then, as shown in FIG. 4, a current is applied to the nickel anode 27 immersed in the electrolytic solution 25 and the tank model 1 as the cathode, thereby depositing nickel (metal) on the model forming surface 1a of the tank model 1 to form the electrodeposition layer 11. This electrodeposition is repeated a number of times (N times) (however, nickel is deposited on the surface of the electrodeposition layer 11 from the second time onward), and the electrodeposition layer 11 is laminated to grow the metal thickness to a predetermined thickness, thereby manufacturing the slush molding die 10.

[0029] Incidentally, in order to improve the quality of the slush skin 35, particularly its thickness accuracy (to keep thickness variations within 0.4 mm), it is necessary to melt and adhere the powdered resin material 40 approximately uniformly to the inner surface 10a of the heated slush molding die 10 during powder slush molding. To melt and adhere the powdered resin material 40 approximately uniformly, it is required that the temperature of the heated slush molding die 10 be approximately uniform (variation in die temperature within 10°C), in other words, that the die thickness of the slush molding die 10 be approximately uniform (variation in thickness within 0.8 mm).

[0030] Therefore, in order to improve the die thickness accuracy of the slush molding die 10 and also to shorten the manufacturing lead time of the slush molding die 10, it is considered to adjust the die thickness of the slush molding die 10 by NC machining using a cutting machine 50, as shown in Figure 5(a). Specifically, it is considered to make the die thickness of the slush molding die 10 approximately uniform by cutting the excess electrodeposited layer 11' laminated on the side opposite to the design surface (inner surface 10a) to which the powder resin material 40 is melted and adhered in the slush molding die 10 after N electrodepositions have been completed, up to a processing line PL defined by coordinate values, as shown in Figure 5(b).

[0031] Here, in order to facilitate understanding of the present invention, a conventional tank entry model will be described.

[0032] Fig. 9 is a diagram showing a conventional tank-entered model 101, where (a) is a cross-sectional view and (b) is a diagram showing the state during electroforming. Fig. 10 is a diagram showing the adjustment of the mold thickness of a slush molding die 110 by NC machining, and Fig. 11 is a diagram showing the problems that arise when the thickness of the tank-entered model 101 is increased.

[0033] As shown in FIG. 9(a), the conventional bath model 101 consists only of a resin layer 103, and like the bath model 1 of this embodiment, has a model molding surface 101a that faithfully reproduces the shape and surface pattern of the slush skin 35. As shown in FIG. 9(b), nickel is deposited by electrodeposition on the model molding surface 101a to form an electrodeposited layer 111.

[0034] However, since the conventional bath model 101 is composed only of the resin layer 103, it is known that it deforms due to stresses generated during electroforming, as shown by the white arrow in Figure 9(b), and as a result, the electrodeposition layer 111 attached to the model molding surface 101a also deforms.

[0035] Therefore, in a slush molding die 110 manufactured using the conventional tank-entering model 101, there is a problem in that it is difficult to make the die thickness of the slush molding die 110 approximately uniform, even if the excess electrodeposit layer 111' laminated on the side opposite the inner surface 110a is cut off up to the processing line PL using a cutting tool 51 as shown in Fig. 10. In other words, when the conventional tank-entering model 101 is used, it is difficult to manufacture a slush molding die 110 with a targeted (designed) die thickness simply by repeating electrodeposition multiple times to laminate the electrodeposit layer 111, and this lacks the premise for applying NC machining, which requires that the workpiece be manufactured to a certain extent according to design.

[0036] For this reason, in electroforming using a conventional tank-entering model 101, as shown in FIG. 7(b), the current situation is that after each preparatory process (electrode preparation, masking, etc.) and electrodeposition, the mold thickness of the electrodeposited layer 111 is adjusted by hand, for example with a sander, and this process is repeated multiple times (N times). This is the reason why adjusting the mold thickness of the slush molding die 110 takes a huge amount of time.

[0037] Here, in order to suppress deformation of tank entry model 101 due to stress during electroforming, etc., it is possible to increase the thickness of tank entry model 101 to increase its rigidity (thickened tank entry model 101 is referred to as tank entry model 101'). However, increasing the thickness of tank entry model 101 also increases the amount of resin, which generates a relatively large amount of heat during the curing reaction, and as shown by the black arrow in Fig. 11, there is a risk that tank entry model 101' will sink due to contraction deformation caused by the heat. In particular, if a sink occurs on model molding surface 101a' corresponding to the design surface of slush molding die 110, there is a problem that tank entry model 101' must be remade from scratch.

[0038] It is also possible to change the material of the tank model 101 to a resin material that is less prone to deformation, but when choosing a resin material that is even less prone to deformation from among those that do not react to the electrolyte 25, the range of choices is extremely narrow, so changing the resin material is not easy.

[0039] Therefore, in this embodiment, the resin tank model 1 is reinforced from the inside and outside without increasing the thickness of the tank model 1. Specifically, as shown in Fig. 1, the tank model 1 of this embodiment has a three-layer structure in which a glass cloth 7 is sandwiched between a resin layer 3 and a resin layer 5 in the thickness direction, and a reinforcing beam 9 for increasing rigidity is provided on the side opposite to the model molding surface 1a.

[0040] According to the tank-entered model 1 of this embodiment, a three-layer structure is adopted in which glass cloth 7, which contributes to improving rigidity without generating heat, is sandwiched between resin layer 3 and resin layer 5 in the thickness direction. This makes it possible to reinforce the resin tank-entered model 1 from the inside without increasing the thickness of the tank-entered model 1, thereby suppressing deformation of the tank-entered model 1 during electroforming.

[0041] Furthermore, since the tank model 1 has a reinforcing beam 9 on the side opposite the model molding surface 1a to increase rigidity, the resin tank model 1 can be reinforced from the outside without interfering with the adhesion of nickel to the model molding surface 1a, i.e., the formation of the electrodeposition layer 11, thereby further suppressing deformation of the tank model 1 during electroforming.

[0042] As a result of these factors combined, deformation of the tank-entered model 1 during electroforming is reduced by, for example, 70% compared to the conventional tank-entered model 101, and as a result, deformation of the electrodeposition layer 11 laminated on the model molding surface 1a side is also reduced, making it possible to achieve the desired mold thickness for the slush molding die 10.

[0043] Then, after N electrodeposition cycles have been completed and the slush molding die 10 has achieved the targeted die thickness, as shown in Figure 5 , the die thickness can be adjusted by NC machining. This reduces variation in the die thickness of the slush molding die 10 by as much as 60%, for example, compared to a slush molding die 110 manufactured using the conventional tank-entered model 101. In other words, the die thickness precision can be improved.

[0044] FIG. 6 is a graph diagram showing the variation in mold temperature of the slush molding dies 10, 110 during heating. More specifically, the graph diagram shown in FIG. 6(b) shows the measurement results of the mold temperature at six points indicated by black circles in FIG. 6(a) during heating for the slush molding dies 110 (conventional examples 1 to 5) manufactured with the conventional tank-entering model 101 and the slush molding die 10 (this embodiment) manufactured with the tank-entering model 1 of this embodiment. As shown in FIG. 6(b), in conventional example 3, which had the largest variation in mold temperature, the variation in mold temperature was 20°C, whereas in this embodiment, it was confirmed that the variation in mold temperature could be suppressed to 7°C. That is, it was confirmed that the slush molding die 10 manufactured with the tank-entering model 1 of this embodiment could reduce the variation in mold temperature by as much as 65% compared to the slush molding die 110 manufactured with the conventional tank-entering model 101.

[0045] In this way, in the slush molding die 10 manufactured using the tank-entering model 1 of this embodiment, the variation in die temperature can be suppressed to within 10°C, which makes it possible to improve the quality (particularly thickness accuracy) of the slush skin 35.

[0046] Moreover, by performing electroforming using the tank-entered model 1 of this embodiment, deformation of the electrodeposition layer 11 laminated on the model molding surface 1a side can be suppressed, and the slush molding die 10 after N electrodepositions have been completed can have a desired die thickness, making it possible to adjust the die thickness by NC machining. As a result, as shown in Fig. 7(a), die thickness adjustment is completed with one NC machining of the slush molding die 10 after N electrodepositions have been completed, or in other words, the work of manually adjusting the die thickness after each electrodeposition as shown in Fig. 7(b) can be eliminated, and therefore, as shown by the black arrow in Fig. 7(a), the production lead time can be significantly shortened compared to the manufacturing process of a slush molding die 110 manufactured using a conventional tank-entered model 101.

[0047] FIG. 8 is a graph diagram showing a schematic breakdown of the lead time for adjusting the mold thickness of the slush molding dies 10 and 110. As shown in FIG. 8, in the conventional example of manufacturing the slush molding die 110 with the conventional tank-entered model 101, it takes 12 days just to adjust the mold thickness by hand. In contrast, in this embodiment, the mold thickness can be adjusted in a total of 5.4 days, including 1.4 days for NC processing, 1.5 days for reinforcing the tank-entered model 1 (inserting the glass cloth 7 and installing the reinforcing beam 9), and 2.5 days for hand processing only for areas that are difficult to process by NC processing. Therefore, in this embodiment, the lead time for adjusting the mold thickness can be shortened by 6.6 days compared to the conventional example.

[0048] (Other embodiments) The present invention is not limited to the embodiments, and can be embodied in various other forms without departing from the spirit or main characteristics thereof.

[0049] In the above embodiment, the variation in mold temperature of the slush molding mold 10 manufactured using the tank model 1 is set to within 10°C, and the variation in mold thickness is set to within 0.8 mm, but these are merely examples, and different standards may be set.

[0050] As such, the above-described embodiment is merely illustrative in all respects and should not be construed as limiting. Furthermore, all modifications and variations within the scope of the claims are within the scope of the present invention. [Industrial Applicability]

[0051] According to the present invention, deformation of the tank model during electroforming can be suppressed and the mold thickness accuracy of the slush molding die can be improved, making it extremely useful when applied to a resin tank model for manufacturing a slush molding die by passing an electric current through an electrolyte. [Explanation of symbols]

[0052] 1. Tank model 1a Model molding surface 3 Resin layer 5 Resin layer 7 Glass Cloth 9 Reinforcement beam 10 Slush molding die 11 Electrodeposition layer 25 Electrolyte

Claims

[Claim 1] A resin-made tank model for manufacturing a slush molding die by laminating an electrodeposition layer made of a metal attached to the model molding surface side by passing an electric current through an electrolyte solution in which metal ions are dissolved, The molded article has a three-layer structure in which a glass cloth is sandwiched between resin layers in a thickness direction, and a reinforcing beam for increasing rigidity is provided on the side opposite to the model molding surface side. The tank-entering model has a recessed portion in which a surface opposite to the model molding surface side is recessed to form a space that is open to one side, and the recessed portion includes a first extending portion extending along one direction, a second extending portion extending from an edge of the first extending portion in a direction intersecting the extending direction of the first extending portion, and a third extending portion extending from an edge of the second extending portion in a direction intersecting the extending direction of the second extending portion and facing the first extending portion; The reinforcing beam includes a first beam connected to a first corner portion which is a boundary portion between the first extension portion and the second extension portion, a second beam connected to a second corner portion which is a boundary portion between the second extension portion and the third extension portion, a third beam connected to a first edge portion which is an edge on the open side of the first extension portion, and a fourth beam connected to a second edge portion which is an edge on the open side of the third extension portion, wherein each of the first beam to the fourth beam is arranged with a space between them and the other beams, and is connected to each other in the center of the space inside the recessed portion.

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