JP2007069446A - Method and apparatus for molding panel for safety device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To form a linear slit at a moment to accord with the solidification state of a molten resin in a fracture part of a panel for a safety device. <P>SOLUTION: A first mold 5 molding a resin panel 1 forming a case for the safety device in which a moving object senses an impact of at least a given value and is actuated and a second mold 6 movable relatively to it are closed. After the resin is injected and molded, a fracture forming piece 7 which is relatively movable to the first mold 5 and forms the fracture part 2 thinning the resin panel 1 partially is set in the second mold 6. The fracture forming piece 7 is a divided fracture forming piece divided into a plurality parts. A plurality of convex blades 4 provided on the side of the resin panel 1 are advanced by each independent reciprocation to form the fracture part 2. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to molding of a safety device panel having a fracture portion. More specifically, the present invention relates to an injection molding die apparatus for providing a resin safety device panel with a breaking portion for popping out the safety device, and a molding technique thereof.

  In recent years, various safety devices for securing the safety of occupants of moving objects have been used and established. For example, when a large impact is applied to a vehicle due to a collision or the like, the safety device is instantly inserted between the moving object and the occupant to prevent the occupant from being subjected to excessive impact. This is to ensure safety.

  This safety device is normally folded and stored in a storage case for moving objects in front of the occupant. In the event of an emergency, the safety device receives an impact activation signal and instantly sends gas to the safety device to break the storage case. It inflates to the passenger side. Due to this swelling, a part of the panel of the housing case is broken, and the safety device itself pops out and expands. The panel is usually a part having a certain strength as a part of the moving object part, but a part of the panel can be easily broken during operation. In addition, when the safety device is stored, it has a structure with no irregularities in appearance.

  In order to pop out the safety device, the panel is preliminarily provided with a cut at the broken portion assuming breakage. When an impact force is applied to the safety device, the fabric safety device bulges out due to the pressure of the high-pressure gas, but the breaks in the panel at the broken portion are set to be weaker than the other portions. For this reason, the panel cuts are stressed and torn along the cuts when subjected to the expansion force of the safety device. An opening is formed in the broken part due to the breakage of the cut, and the inflated safety device jumps out from the opening to the passenger side.

  The panel cut is provided when the panel is molded. When the panel breaks, the cuts must break evenly and stably, and the broken pieces must not be scattered. For this reason, panel formation for safety devices requires advanced molding technology from the viewpoint of safety. For this reason, various developments have been made in the related art. However, at present, there are many problems such as the tendency of the manufacturing process to be complicated, and there has been a demand for a further improved technology with a simpler configuration.

As a conventional safety device-related technique, for example, in a mold for molding a panel, a technique for simultaneously operating a plurality of cores in a mold to make a cut in the panel (see Patent Document 1) is known. Yes. In addition, a laser beam is used to form a rupture portion, and a groove is formed to make the cut portion of the rupture portion thin (see Patent Document 2), or the shape of the rupture groove of the panel to be formed is limited. For example, a technique (see Patent Document 3) that simultaneously and integrally molds the panel itself including the fracture portion is known.
Japanese Patent No. 3615165 JP-A-11-291069 JP 2000-108833 A

  As described above, it is known that the conventional technique is also effective and implemented. However, the safety device is a safety device for moving objects, and the degree of certainty of the certainty is severe due to the presence of passengers. Also, it must be mass-produced and can be manufactured in a short time. For this reason, advanced manufacturing techniques for the related parts are required. The panel which hits the case of the safety device is arranged at the front part on the passenger side of the moving object and is generally made of synthetic resin.

  As described above, the back surface of the synthetic resin panel is provided with a cut for popping and breaking the safety device. This break must be a break that breaks evenly and reliably when broken. When the panel is molded, the flow of the molten resin injected from the gate to the cavity is not a uniform flow in all the parts. For this reason, the solidification speed of a panel changes with parts. The process of providing a cut in the panel is performed by checking the timing during solidification.

  The panel has a wide area, and the broken resin which is a part of the panel does not necessarily have a uniform flow of the molten resin over the entire surface of the panel. Moreover, even if the panel for safety devices has a cut on the back surface, the surface must be flat and have a design without unevenness or sink marks. For such a panel, it is necessary to ensure a uniform and stable cut along the fracture line regardless of the panel molding conditions and at any site where the fracture occurs.

  Examining the prior art, in Patent Document 1, all the breaks of the fractured portion are formed simultaneously by the protruding blade in the same process, but the molten resin that is injected by placing a heating device in the mold is used. The above-mentioned problem is solved by heating to a uniform temperature. However, this method partially increases the temperature, and does not change the mold temperature by managing it. There is also a problem in that the mold structure is complicated. Patent Document 2 is a method of processing a lid with a laser beam, but it requires advanced processing control and cannot be processed in a short time, and particularly in mass-produced parts, the manufacturing efficiency is poor.

  Furthermore, the technique of Patent Document 3 is to simultaneously form a cut at the stage of injection molding of the panel body. However, the cut line depends on the groove shape, and it is necessary to set a groove shape that satisfies the optimum conditions such as the flow direction of the resin, the flow speed, and the thickness of the cut portion. In particular, the groove angle is constrained, and the above-mentioned problem cannot be cleared when the fracture length is long.

  The present invention has been developed to solve the above-described problems of the conventional technical background, and achieves the following object. The objective of this invention is providing the shaping | molding apparatus of the panel for safety devices which can form a cut | interruption with a simple structure equally to the fracture | rupture part formed in the linear form of the panel for safety devices, and its technique. Another object of the present invention is to provide a safety device panel molding apparatus and its technology which have a simplified structure and are intended to reduce costs.

The present invention adopts the following means in order to achieve the object.
The safety device panel molding apparatus according to the first aspect of the present invention includes a first mold for molding a resin panel that forms a case for a safety device that operates when a moving object senses an impact of a certain value or more, and
A second mold that moves relative to the first mold and molds the resin panel;
After the first mold and the second mold provided in the second mold are closed and resin is injected to mold the resin panel, the thickness of the resin panel is increased by relative movement with respect to the first mold. In a safety device panel molding device having a fracture forming piece for partially thinning and forming a fracture portion,
The rupture forming piece is a divided rupture forming piece divided into a plurality of pieces, and each of the divided rupture forming pieces forms the rupture portion by an independent reciprocating motion.

  The safety device panel forming apparatus according to the second aspect of the present invention is the apparatus according to the first aspect of the present invention, wherein the divided fracture forming piece has a configuration in which a plurality of convex blades for forming a fractured portion are linearly arranged at the panel side end. It is characterized by being.

  According to a third aspect of the present invention, there is provided the safety device panel molding device according to the first aspect, wherein the split fracture forming piece has a driving device for reciprocating driving arranged in the second mold. .

  According to a fourth aspect of the safety device panel forming apparatus of the present invention, in the first aspect of the present invention, the split fracture forming piece is configured such that the convex blades at both ends in the linear fracture row direction can perform different reciprocating motions. It is characterized by becoming.

The method for molding a safety device panel according to the fifth aspect of the present invention is a method for molding a safety device panel in which a moving object senses an impact of a certain value or more due to a collision or the like and operates.
After the second mold that moves relative to the first mold of the mold for molding the resin panel of the safety device panel moves and closes the two molds, the resin is injected to mold the resin panel. Process,
In a state where the two molds are closed, the plurality of split fracture forming pieces provided in the second mold are reciprocated by a set value that is independently set on the molded resin panel. And forming the fracture portion in the resin panel.

  The safety device panel molding method according to the sixth aspect of the present invention is the method of molding the resin panel according to the fifth aspect, wherein the step of molding the resin panel forcibly raises the temperature of the mold to a predetermined temperature to inject and hold the resin. It is a step of forming the mold by forcibly lowering the temperature of the mold to a predetermined temperature in a short time after pressing.

  In the safety device panel molding method of the present invention 7, in the present invention 5, the set value is a time required to reach a predetermined temperature of the mold.

  The safety device panel molding method of the present invention 8 is characterized in that, in the present invention 5, the set value is a set value of a predetermined temperature of the mold.

  As described above in detail, the present invention can be constructed in accordance with the solidified state of the resin panel at the time of molding. In other words, the breaks in the panel can be realized at a low cost by temperature control or time management of the mold. For this reason, the cuts were uniform and stable.

  Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a resin panel 1 showing an embodiment of the present invention. The resin panel 1 is made of synthetic resin, and in this example, the thickness is 2.5 to 4.5 mm. FIG. 1 is a partial external view showing a portion of a fracture portion 2 of a resin panel 1 used as a safety device for moving objects. FIG. 1 shows the appearance of the resin panel 1, but the part related to the present invention is an H-shape in which the break 3 of the fractured portion 2 is shown as a dotted line on the back surface of the resin panel 1 as a protruding area of the safety device. It is shown. The cut 3 is divided into cuts 3a, 3b, and 3c having three tear lines.

  As shown in the cross-sectional views of the resin panel 1 in FIGS. 2 and 3, the cut 3 has a shape in which the cross-section is cut into a triangular blade shape, and a part of the thickness of the resin panel 1 is partially obtained. It is thinned. 2 is a cross-sectional view taken along line XX in FIG. 1, and FIG. 3 is a cross-sectional view taken along line YY in FIG. In the figure, the blade-like portion is formed by a plurality of convex blades 4 (described later) having a small width and arranged at a constant pitch. When the convex blade 4 is cut into the resin panel 1, cuts 3a, 3b, and 3c indicated by tear lines are formed in the resin panel 1. The thickness 3d of the thick portions of the cuts 3a, 3b, and 3c is, for example, 0.3 to 1.0 mm.

  4 and 5 show a mold configuration for forming the cuts 3a and 3b indicated by tear lines. The configuration shown in the figure shows an open state of the mold. The mold is composed of a fixed mold 5 and a movable mold 6 that is movable relative to the fixed mold 5, and a mold for forming the resin panel 1 between the two molds, that is, a cavity. Is provided. When the two molds are closed, resin is injected into the cavity to mold the resin panel 1.

  The movable die 6 is provided with a piece 7 for making a cut 3 in the fractured portion 2 of the molded resin panel 1 so as to freely advance and retract. The piece 7 is provided as divided pieces 7a and 7b divided corresponding to the divided cuts 3a and 3b of the resin panel 1, respectively. Each of the divided pieces 7a and 7b can advance and retreat independently, and the rods of the hydraulic cylinders 8a and 8b for driving the divided pieces 7a and 7b are connected to the divided pieces 7a and 7b.

  That is, the hydraulic cylinder 8a is individually provided in the divided piece 7a corresponding to the cut 3a, and the hydraulic cylinder 8b is individually provided in the divided piece 7b corresponding to the cut 3b. Although not shown, a split piece 7c and a hydraulic cylinder 8c are similarly provided corresponding to the cut 3c. That is, the divided pieces 7a, 7b, and 7c are connected to the hydraulic cylinders 8a, 8b, and 8c via the support members 9a, 9b, and 9c.

  The support member 9 is also an adjustment member having a function of aligning the divided pieces 7a, 7b, 7c and the hydraulic cylinders 8a, 8b, 8c. The hydraulic cylinders 8a, 8b, and 8c are fixed by protruding piston rods 10a, 10b, and 10c into the piece chamber 11. The hydraulic cylinder 8a will be described. The support member 9a is fixed to the piston rod 10a that moves forward and backward at the end of the hydraulic cylinder 8a.

  A plurality of convex blades 4 for cutting are provided at the panel side end of the split piece 7a. The convex blade 4 is opposed to the resin panel 1 and moves forward and backward with respect to the resin panel 1 by the operation of the piston rod 10a of the hydraulic cylinder 8a. The division piece 7a is housed in the piece chamber 11a of the movable mold 6 and is configured to be guided at a fixed position. Moreover, in the operation | movement with respect to the resin panel 1, since the convex blade 4 is positioned correctly with respect to the resin panel 1, the advance / retreat position of the convex blade 4 is controlled.

  That is, an abutting step 12a is provided on the panel side of the piece chamber 11a, and when the convex blade 4 or the dividing piece 7a reaches the moving end at the step 12a, the dividing piece 7a is abutted against the step 12a. I have to. FIG. 4 shows a state in which the mold is open and the convex blade 4 is retracted to the piece chamber 11a side and is waiting at a fixed position. The adjacent divided piece 7b has the same configuration as the divided piece 7a.

  FIG. 5 is a ZZ cross-sectional view of FIG. 4, in which a plurality of convex blades 4 are linearly arranged at small intervals along the tear line of the cut 3 a shown in FIG. 1. The plurality of convex blades 4 are moved forward and backward by one hydraulic cylinder 8a. FIG. 6 shows a configuration in which two molds are closed. After the two molds are closed, resin is injected into the panel-shaped cavity to mold the resin panel 1.

  The convex blade 4 is advanced in the process of solidifying the panel-shaped resin, and is pressed against the molded resin panel 1. This pressing is performed at a delicate timing, but before the resin panel 1 is completely solidified in the molding solidification process. If the pressure is too early and the resin is still soft, there is a risk that the shape of the cut will not be stable and the cut will not have an accurate thickness. Further, if the resin is pressed after the solidification has progressed and the resin has become hard, the resin panel 1 may be bitten by an unreasonable force, and the resin panel 1 may be cracked or sag.

  Thus, it is necessary to press the convex blade 4 against the resin panel 1 when the resin panel 1 is in an optimal state in the solidifying process. When the molding process of the resin panel 1 is examined, the entire resin panel 1 is not necessarily solidified uniformly in each part. The solidified state varies depending on the position of the resin panel 1, the direction and position of the molten resin flow. In the present embodiment, the convex blade 4 is pressed against the resin panel 1 immediately after molding at different timings according to the difference in the solidification conditions.

  In this embodiment, as described above, the movable mold 6 is provided with the dividing pieces 7a, 7b, and 7c that move forward and backward independently corresponding to the three cuts 3a, 3b, and 3c of the resin panel 1. It has a configuration. For this reason, the moving operation | movement of the division | segmentation piece 7a, 7b, 7c which shifted timing according to the solidification conditions in the three cut | interruptions 3a, 3b, 3c can be performed.

  For example, if the cut 3a side solidifies faster than the cut 3b side, the divided piece 7a can be advanced and pressed at an earlier timing than the divided piece 7b. As a result, the division pieces 7a and 7b are operated with respect to the resin panel 1 under substantially the same solidification conditions. This makes the shape of the cut 3 in the same state and enables formation of the stable cut 3.

  FIG. 7 is a flowchart showing an example of operation timing of the divided pieces 7a, 7b, and 7c. Molten resin is injected into the injection mold from the nozzle of the injection molding apparatus, and molding of the resin panel 1 is started (101). When the set time has elapsed since the injection of the nozzle (102), the solenoid valve of the hydraulic cylinder 8a is opened. For this purpose, hydraulic pressure is introduced into the hydraulic cylinder 8a, and the split piece 7a is driven (103).

  After driving the divided piece 7a, similarly, after a predetermined timing (104, 106), the hydraulic cylinder 8b and the hydraulic cylinder 8c are driven, and the divided pieces 7b and 7c are sequentially driven (105, 107). The timing of driving the divided pieces 7a, 7b, and 7c varies depending on the gate position, the type of resin, the nozzle temperature, and the mold temperature, but is determined experimentally or empirically.

  As described above, the operation method of the split piece has been described on the premise that the solidified state of the molten resin at the portion of the cut 3 is different. Next, a case where the tear line is long along the flow of the molten resin at the time of molding will be described. For example, in the case of the cut line 3c, if the molten resin flows from one end side to the other end side during molding along the tear line of the cut line 3c, both ends along the tear line are formed when the resin panel 1 is molded. The solidified state of the part will be different. In this case, the above-mentioned problems can be solved by shifting the forward and backward movement of the convex blades 4 arranged at both ends.

  An example of the structure is shown in FIG. Similarly to the cut lines 3a and 3b, a split piece 7c in which a plurality of convex blades 4 are arranged in the tear line direction of the cut line 3c is provided in the piece chamber 11c of the movable mold 6. The divided piece 7c moves forward and backward by driving the hydraulic cylinder 8c with respect to the resin panel 1 immediately after being molded. A spring support 7 e is provided at one end 7 d in the arrangement direction of the divided pieces 7 c and is urged by a spring 13 installed in the movable mold 6.

  In this embodiment, the spring 13 is a tension spring that biases the split piece 7c toward the hydraulic cylinder 8c. However, the spring 13 may be a coil spring by changing the installation position. The spring 13 is not provided at the other end 7f of the split piece 7c. The mounting structure between the support member 9c and the piston rod 11c of the hydraulic cylinder 8c is a structure in which the support member 9c is supported by the piston rod 11c by a pin 14 so as to be swingable. The piece chamber wall 6a of the movable mold 6 that comes into contact with the support member 9c or the divided piece 7c constitutes a guide portion that can move straight while the divided piece 7c swings.

  For this purpose, the guide member 7g that enables the support member 9c or the split piece 7c to swing forms a curved surface. When the split piece 7 c having such a configuration enters the pressing operation against the resin panel 1, the end 7 d on the side where the spring 13 is located moves forward while being lifted by the urging force of the spring 13. For this reason, the convex blade 4 of the end portion 7 f having no spring first reaches the pressing end with respect to the resin panel 1. The other convex blades 4 are sequentially pressed against the resin panel 1, and finally the convex blade 4 on the spring side is pressed against the resin panel 1. In this way, a shift occurs in the operation of both ends.

  With this operation, the convex blade 4 on the side without the spring 13 is first pressed against the resin panel 1 portion on the fast-solidifying side, and the spring-side convex blade 4 is pressed against the resin panel 1 portion on the slow-solidifying side. To do. By doing in this way, even if it is the same hydraulic cylinder structure with the same division | segmentation piece, the shift | offset | difference of a pressing operation can be produced corresponding to the solidification conditions of the resin panel 1. FIG. This can be similarly applied to the divided pieces 7a and 7b if necessary.

  Next, another embodiment of the molding method will be described. As shown in FIG. 9, this method is an example of molding by raising or lowering the temperature of the mold in cycles. In this method, the mold temperature is forcibly raised to a temperature equal to or higher than the thermal deformation temperature before injection (201), and injection is performed to bring the panel into a pressure-holding state (202). Next, after this injection pressure holding state is completed, the mold temperature is forcibly lowered in a short time (203). In this process, when the temperature reaches a predetermined temperature, the hydraulic cylinder is operated at the timing of the lowered temperature to press the convex blade of the piece (204 to 209).

  When all the pieces are pressed by the cylinder operation in this way and the panel is solidified, the panel molded product is taken out from the mold (210). When the panel molded product is taken out, the mold temperature is forcibly raised again and the above cycle is repeated. Although not shown, the mold temperature can be raised or lowered by installing a heating device, a temperature sensor, a timer, etc., and the pressing operation of the convex blade of the piece can be controlled.

  By forcibly raising or lowering the mold temperature in this way, the molding process of the mold is accelerated, and by setting the temperature, it is possible to construct an accurate cut by temperature management by sensing the temperature sensor. . This treatment method also has an effect of improving the surface finish of the cut. If the temperature drop of the mold is constant, the pressing operation of the convex blade of the piece can be performed by looking at the timing by time management by time setting instead of temperature management as in the above example.

  In the present invention, a resin panel having a stable cut for a safety device can be formed by the mold configured as described above, but it goes without saying that the present invention is not limited to the above-described embodiments. Nor. The present invention is a panel forming apparatus and its forming technique related to a safety device applied to a moving object, and is particularly useful when applied to a vehicle such as an automobile, but is not limited thereto. For example, it is needless to say that the present invention may be applied to a moving object such as a roller coaster that is an amusement facility as a panel forming device for a passenger safety device and its forming technology.

FIG. 1 is a partial external view showing a broken portion of a resin panel for a safety device. FIG. 2 is a sectional view taken along line XX in FIG. 3 is a cross-sectional view taken along line YY of FIG. FIG. 4 is a partial cross-sectional view showing a mold configuration in an open state for forming a cut. FIG. 5 is a ZZ cross-sectional view of FIG. FIG. 6 is a partial cross-sectional view showing the mold configuration in a closed state for forming a cut. FIG. 7 is a flowchart showing an example of operation timing of the divided pieces 7a, 7b, and 7c. FIG. 8 is a partial cross-sectional view illustrating a configuration example in which pressing is performed while shifting the timing of the convex blade along the tearing direction of the cut. FIG. 9 is a flowchart showing an example of the operation timing of the divided pieces 7a, 7b, and 7c in another embodiment for changing the mold temperature.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Resin panel 2 ... Breaking part 3 ... Cut 4 ... Convex blade 5 ... Fixed metal mold 6 ... Movable metal mold 7 ... Divided piece 8 ... Hydraulic cylinder 9 ... Supporting member 13 ... Spring

Claims (8)

A first mold for molding a resin panel that forms a case for a safety device in which a moving object senses and operates an impact of a certain value or more;
A second mold that moves relative to the first mold and molds the resin panel;
After the first mold and the second mold provided in the second mold are closed and resin is injected to mold the resin panel, the thickness of the resin panel is increased by relative movement with respect to the first mold. In a safety device panel molding device having a fracture forming piece for partially thinning and forming a fracture portion,
The break-breaking piece is a divided breakage-breaking piece divided into a plurality of pieces, and each of the breakage-breaking pieces forms the breakage portion by an independent reciprocating motion. Panel molding equipment. In the molding apparatus of the panel for safety devices of Claim 1,
2. The safety device panel molding apparatus according to claim 1, wherein the split fracture forming piece has a configuration in which a plurality of convex blades for forming the fracture portion are arranged linearly at the panel side end. In the molding apparatus of the panel for safety devices of Claim 1,
In the split fracture forming piece, a driving device for a reciprocating driving operation is arranged in the second mold. A panel forming apparatus for a safety device. In the molding apparatus of the panel for safety devices of Claim 1,
2. The safety device panel forming apparatus according to claim 1, wherein the split fracture forming piece is configured such that the convex blades at both ends in the direction of the linear fracture row are capable of different reciprocating motions. In a method for forming a panel for a safety device in which a moving object senses an impact of a certain value or more due to a collision or the like,
After the second mold that moves relative to the first mold of the mold for molding the resin panel of the safety device panel moves and closes the two molds, the resin is injected to mold the resin panel. Process,
In a state where the two molds are closed, the plurality of split fracture forming pieces provided in the second mold are reciprocated by a set value that is independently set on the molded resin panel. And forming the fracture portion on the resin panel. A method for forming a panel for a safety device. In the molding method of the panel for safety devices according to claim 5,
In the step of molding the resin panel, the temperature of the mold is forcibly raised to a predetermined temperature to inject and hold the resin, and after the injection and pressure holding, the temperature of the mold is forcibly lowered to the predetermined temperature in a short time. Thus, a method for forming a panel for a safety device, which is a step of forming. In the molding method of the panel for safety devices according to claim 5,
The method for forming a panel for a safety device, wherein the set value is a time required to reach a predetermined temperature of the mold. In the molding method of the panel for safety devices according to claim 5,
The method of molding a safety device panel, wherein the set value is a set value of a predetermined temperature of a mold.

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