JP3825170B2 - Mold device for lid forming of airbag device and lid - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention mainly relates to a lid forming mold apparatus and a lid for an airbag apparatus.
[0002]
[Prior art]
Some vehicles such as automobiles have an airbag device as a safety means in an emergency. As shown in FIG. 6, the airbag device includes an inflator 1 that ejects a pressure gas, and an airbag 2 that is inflated by the pressure gas from the inflator 1. The airbag 2 is housed in a housing 3 in a folded state and covered with a lid 4. The lid 4 is formed with a cleavage groove 5 that is substantially H-shaped when viewed from above. As shown in FIG. 7, the airbag device is disposed in the opening 7 formed on the upper surface of the instrument panel 6 of the vehicle so that the lid 4 is flush with the instrument panel 6. Has been.
[0003]
In the airbag device, when an impact force of a predetermined value or more is applied to the vehicle body, the airbag 2 is inflated by the pressure gas from the inflator 1, and the cleavage groove 5 formed in the lid body 4 by the inflation pressure. And bulges into the passenger compartment, catches the head of the passenger, and protects the head from touching the instrument panel 6 and the like.
[0004]
In the figure, reference numeral 8 denotes an insert cloth embedded in a portion other than the cleavage groove 5 of the lid 4.
[0005]
The lid 4 has heretofore been formed by injecting a resin into a mold having a protrusion on the portion corresponding to the cleavage groove 5.
[0006]
However, since the protrusion portion narrows the molding space of the mold, the flow of the resin injected at the protrusion portion is hindered, causing a molding defect.
[0007]
Therefore, in order to eliminate molding defects, a lid manufacturing means as shown in JP-A-3-254919 has been proposed. As shown in FIGS. 8 and 9, the lid manufacturing means can move the movable mold 12 having the protrusions 11 in the portions corresponding to the cleavage grooves 5 of the molds 9 and 10 by the movable device 13. After the resin 15 is injected from the injection port 14 into the molding space of the molds 9 and 10, the movable mold 12 is advanced by the movable device 13 to press the resin 15, thereby forming the cleavage groove 5.
[0008]
By doing in this way, since the lid 4 can be molded without impairing the fluidity of the resin 15, molding defects are eliminated and the product yield can be improved. Further, since the cleavage groove 5 is formed by pressing the resin 15 with the movable mold 12, the density of the resin in the cleavage groove 5 portion increases, the strength of the portion increases, and the cover 4 is prevented from being sticky. Can do.
[0009]
[Problems to be solved by the invention]
In such conventional lid manufacturing means, the resin 15 is pressed by the movable mold 12 to form the cleavage groove 5, but the density of the resin in the cleavage groove 5 portion is increased uniformly. Therefore, it becomes impossible to know from which part of the cleavage groove 5 the cleavage is started, and the airbag 2 may be unevenly bulged.
[0010]
Accordingly, an object of the present invention is to provide a lid forming mold apparatus and a lid body for an airbag apparatus that can solve the above-mentioned problems and can set a cleavage start position of a cleavage groove.
[0011]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, in the invention described in claim 1, in the molding die device for injection molding the lid of the airbag device having the cleavage groove, the portion that becomes the cleavage start position of the cleavage groove is molded. The mold surface is provided with a protrusion, and a movable mold is provided in which a portion that becomes a cleavage groove other than the cleavage start position is driven forward and pressed after injection of the resin material.
[0012]
In the invention according to claim 1 configured as described above, after injecting resin into the molding space of the mold forming the lid, the movable mold is advanced by the movable device to press the resin, thereby forming the cleavage groove.
[0013]
At this time, protrusions are formed in the molding space at the portion where the cleavage groove starts to be opened, but the protrusions are small and locally scattered, which hinders resin flow. There is almost no such thing. Therefore, molding defects do not occur in this portion, and an improvement in product yield can be obtained. In addition, since the part that becomes the cleavage groove other than the cleavage start position is formed by pressing the resin with a movable mold, the density of the resin in the part of the cleavage groove is increased, and the strength of the part is increased. It is possible to make a lid with little bevel.
[0014]
Furthermore, by forming protrusions in the part of the molding space that becomes the cleavage start position of the cleavage groove, this part has the same density as the general thick part of the lid and the thickness is almost the same as other parts of the cleavage groove. Therefore, this part has the weakest strength. Therefore, this part can be reliably set as the cleavage start position. Therefore, it is possible to make a lid that can be inflated without biasing the airbag.
[0015]
According to a second aspect of the present invention, in the molding die device for injection molding the lid of the airbag device having the cleavage groove, the cleavage groove has a corner, and the cleavage groove has a cleavage start position. Protrusions are provided on the mold surface for molding the part to be formed and the part to be the corner, and a movable mold is provided to drive and press-mold the part to be the cleavage groove other than the cleavage start position and the corner after resin material injection It is characterized by that.
[0016]
In the invention according to claim 2 configured as described above, in addition to the same operation as that of claim 1, the protrusion is formed at the corner portion of the cleavage groove in the molding space. Is the same as the general thick part of the lid and the thickness is the same as the other part of the cleavage groove, so that this part also has the weakest strength as described above. Therefore, the direction of cleavage can be changed well, and a lid that can be reliably cleaved can be produced.
[0017]
Further, the invention described in claim 3 is characterized in that the movable mold is disposed at a slightly advanced position before injection molding.
[0018]
In the invention according to claim 3 configured as described above, the density of the portion to be press-molded of the cleavage groove can be slightly lowered by disposing the movable mold at the slightly advanced position before injection molding. Therefore, the cleavability can be improved accordingly.
[0019]
Further, in the invention described in claim 4, in the lid body of the airbag device having the cleavage groove, the density of the part that becomes the cleavage start position of the cleavage groove is set to the density of the part that becomes the cleavage groove other than the cleavage start position. It is characterized by being smaller than the density.
[0020]
In the invention according to claim 4 configured as described above, since the density of the part that becomes the cleavage start position is smaller than the density of the other part of the cleavage groove, it is possible to reliably perform the cleavage from the cleavage start position. it can.
[0021]
Furthermore, in the invention described in claim 5, in the lid body of the airbag device having the cleavage groove, the cleavage groove has a corner portion, and the density of the portion that becomes the cleavage start position and the corner portion of the cleavage groove is set. Further, the present invention is characterized in that it is made smaller than the density of the portion that becomes the cleavage groove other than the cleavage start position and the corner .
[0022]
In the invention according to claim 5 configured as described above, since the density of the cleavage starting position and the corner portion is smaller than the density of the other part of the cleavage groove, the cleavage is surely performed from the cleavage starting position. Thus, the direction of cleavage can be changed at the corners.
[0023]
DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1
Hereinafter, a specific first exemplary embodiment of the present invention will be described together with illustrated examples.
[0024]
1 to 3 show Embodiment 1 of the present invention.
[0025]
First, the configuration will be described. In the first embodiment, the cleavage groove H in the molding space 18 of the dies 16 and 17 for molding the lid of the airbag device having the substantially H-shaped cleavage groove is described. The protrusion 20 is provided at a position (a cleavage start position) substantially corresponding to the center of the character connecting line portion 19.
[0026]
Further, a protrusion 22 is provided at a position (corner) corresponding to the junction of the H-shaped parallel line portion 21 and the connecting line portion 19 of the cleavage groove in the molding space 18.
[0027]
Finally, a movable mold 23 for pressing and forming the cleavage groove is provided at each position corresponding to the portion other than the above of the H shape of the cleavage groove so as to be movable forward and backward by the movable device 24.
[0028]
In the figure, reference numeral 25 denotes a resin injected into the molding space 18.
[0029]
Next, the operation of the first embodiment will be described with reference to FIGS.
[0030]
After the resin 25 is injected into the molding space 18 of the molds 16 and 17 for molding the lid, the movable mold 23 is advanced by the movable device 24 to press the resin 25 to form an H-shaped cleavage groove.
[0031]
At this time, a protrusion 20 is formed in the molding space 18 at a position substantially corresponding to the center of the H-shaped connecting line portion 19 of the cleavage groove, and the H-shaped parallel line portion 21 of the cleavage groove and the connecting line. The protrusion 22 is formed at a position corresponding to the junction with the portion 19, but the protrusions 20 and 22 are small and locally scattered, so that the flow of the resin 25 is hindered. There is almost nothing. Therefore, molding defects do not occur in this portion, and an improvement in product yield can be obtained. Further, since the portion other than the above of the H shape of the cleavage groove is formed by pressing the resin 25 with the movable mold 23, the density of the resin 25 in the portion of the cleavage groove is increased and the strength of the portion is increased. It can be raised and a lid with little bevel can be made.
[0032]
Furthermore, by forming the protrusion 20 at a position corresponding to the approximate center of the H-shaped connecting line portion 19 of the cleavage groove in the molding space 18, this portion has the same density as the general thick portion of the lid. Since the thickness is almost the same as the other part of the cleavage groove (that is, smaller than the density of the other part of the cleavage groove), this part has the weakest strength. Therefore, this part can be reliably set as the cleavage start position. Therefore, it is possible to make a lid that can be inflated without biasing the airbag.
[0033]
In addition, since the protrusion 22 is formed at a position (corner portion) corresponding to the confluence of the H-shaped parallel line portion 21 and the connecting line portion 19 of the cleavage groove in the molding space 18, this portion has a density of Is the same as the general wall thickness of the lid (ie, smaller than the density of the other part of the cleavage groove), and the thickness is the same as the other part of the cleavage groove. The strength is weakened. Therefore, the direction of cleavage can be successfully changed from the H-shaped connecting line portion 19 of the cleavage groove to the parallel line portion 21, and a lid that can be reliably cleaved along the parallel line portion 21 can be made. It becomes.
[0034]
As shown in FIG. 4, when the resin 25 is injected into the molding space 18, the movable mold 23 is moved forward by a slight amount 26 so that the flow of the resin 25 is not impaired. Even if the density of the crevice groove part after pressing with the general thick part where the crevice groove is not formed is slightly higher than the general thick part, the strength is slightly weaker. Since it becomes easy to do, predetermined cracking along a cleavage groove | channel can be performed simultaneously with making a bevel small.
[0035]
Second Embodiment of the Invention
FIG. 5 shows a second embodiment of the present invention. The same or equivalent parts as those in the first embodiment will be described with the same reference numerals.
[0036]
First, the configuration will be described. In the second embodiment, the ridges 27 are formed at positions corresponding to the H-shaped parallel line portions 21 of the cleavage grooves in the molding space 18.
[0037]
Thus, by forming the protrusion 27 in the position corresponding to the H-shaped parallel line portion 21 of the cleavage groove, the parallel line portion 21 has the same density as the general thick portion of the lid (that is, Since the thickness is the same as that of the other part of the cleavage groove), the parallel line part 21 has the lowest strength. Therefore, the direction of the cleavage can be successfully changed from the H-shaped connecting line portion 19 of the cleavage groove to the parallel line portion 21, and a lid that can be reliably cleaved along the parallel line portion 21 is produced. Is possible.
[0038]
Except for the above, the configuration is the same as that of the above-described embodiment, and the same actions and effects can be obtained.
[0039]
The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and the present invention can be changed even if there is a design change or the like without departing from the gist of the present invention. included.
[0040]
For example, the cleavage groove has been described as being H-shaped, but it may be L-shaped or U-shaped.
[0041]
【The invention's effect】
As described above, according to the first aspect of the present invention, the forming space is formed with the protrusion at the portion where the cleavage groove is to be opened, but the protrusion is small and locally scattered. Therefore, there is almost no hindrance to resin flow. Therefore, molding defects do not occur in this portion, and an improvement in product yield can be obtained. In addition, since the part that becomes the cleavage groove other than the cleavage start position is formed by pressing the resin with a movable mold, the density of the resin in the part of the cleavage groove is increased, and the strength of the part is increased. It is possible to make a lid with little bevel.
[0042]
Furthermore, by forming protrusions in the part of the molding space that becomes the cleavage start position of the cleavage groove, this part has the same density as the general thick part of the lid and the thickness is almost the same as other parts of the cleavage groove. Therefore, this part has the weakest strength. Therefore, this part can be reliably set as the cleavage start position. Therefore, it is possible to make a lid that can be inflated without biasing the airbag.
[0043]
According to the second aspect of the present invention, since the protrusion is formed in the portion that becomes the corner portion of the cleavage groove in the molding space, this portion has the same density as the general thick portion of the lid body and the thickness of the cleavage groove. Since it becomes the same as the other portions, the strength of this portion is the weakest in the same manner as described above. Therefore, the direction of cleavage can be changed well, and a lid that can be reliably cleaved can be produced.
[0044]
According to the invention of claim 3, by placing the movable mold in the slightly advanced position before injection molding, it becomes possible to slightly reduce the density of the press-molded portion of the cleavage groove, and accordingly, The cleavage property of the cleavage groove can be improved.
[0045]
According to the invention of claim 4, since the density of the portion that becomes the cleavage start position is smaller than the density of the other portion of the cleavage groove, the cleavage can be reliably performed from the cleavage start position.
[0046]
According to the invention of claim 5, since the density of the portion that becomes the cleavage start position and the corner portion is smaller than the density of the other portion of the cleavage groove, the corner portion is reliably cleaved from the cleavage start position. It is possible to exert a practically beneficial effect that the direction of the cleavage can be changed by.
[Brief description of the drawings]
FIG. 1 is a plan view of a molding space according to a first embodiment of the present invention.
FIG. 2 is a side sectional view of a mold having the molding space of FIG.
FIG. 3 is an operation diagram showing a state after FIG. 2;
FIG. 4 is an operation diagram showing a molding method different from FIG. 2;
FIG. 5 is a plan view of a molding space according to the second embodiment of the present invention.
FIG. 6 is a schematic side sectional view of the airbag device.
FIG. 7 is a perspective view of an instrument panel provided with an airbag device.
FIG. 8 is a side sectional view showing a conventional example.
FIG. 9 is an operation diagram showing the state after FIG. 8;
[Explanation of symbols]
16, 17 Mold 18 Molding space 19 Connecting line part 20, 22 Protrusion 21 Parallel line part 23 Movable mold 24 Movable device 27 Projection

Claims (5)

  In a molding die device for injection molding of a lid of an airbag device having a cleavage groove, a protrusion is provided on a mold surface for molding a portion to be a cleavage start position of the cleavage groove, and a cleavage groove other than the cleavage start position is provided. A mold apparatus for forming a lid body for an airbag apparatus, wherein a movable mold is provided in which a portion to be moved forward is pressed after injection of a resin material. In a molding die device for injection-molding a lid of an airbag device having a cleavage groove, the cleavage groove has a corner portion, and a mold that molds a portion to be a cleavage start position and a corner portion of the cleavage groove A lid body for an airbag apparatus, wherein a protrusion is provided on the surface, and a movable mold is provided for forwardly driving and press-molding a portion that becomes a cleavage groove other than the cleavage start position and the corner after injection of a resin material. Mold device for molding.   3. The lid forming mold apparatus for an airbag apparatus according to claim 1, wherein the movable mold is disposed at a slightly advanced position before injection molding.   In the lid of an airbag device having a cleavage groove, the density of the portion that becomes the cleavage start position of the cleavage groove is made smaller than the density of the portion that becomes the cleavage groove other than the cleavage start position. The lid of the device. In a lid body of an airbag device having a cleavage groove, the cleavage groove has a corner portion, and the density of the cleavage start position and the portion that becomes the corner portion of the cleavage groove is determined based on the cleavage start position and the cleavage groove other than the corner portion. A lid body for an airbag device, characterized in that the density is lower than the density of the portion to be.

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