JP5134191B2 - Shoe sole injection molding method and apparatus, and footwear manufactured by the same - Google Patents

Description

  The present invention relates to an injection molding method and apparatus for injecting an injection material into the injection space after an insert is previously disposed in an injection space configured by combining a lower mold or a last mold and a plurality of molds. It relates to manufactured footwear.

Conventionally, in order to mold a shoe sole, an injection is injected into an injection space formed by combining molds at the lower part of an upper (cover) attached to a last mold as a foot mold, and then It is done by curing. From the standpoint of securing characteristics to alleviate the impact on the foot from the road surface, an insert of a material other than the shoe sole component is usually interposed in the shoe sole component. As such an example, one manufactured by an injection molding method as disclosed in Patent Documents 1 and 2 below has been proposed.
Japanese Utility Model Publication No. 7-37522 (see FIG. 4 and paragraphs 0017 and 0018) JP-A-2-224602 (see FIGS. 1 and 2 and page 3, column 3)

  The shoe sole disclosed in Patent Document 1 will be described with reference to FIG. A cavity 115 formed by a last mold 112 into which a bag-like body in which a collar 101 and an insole 102 are sewn is inserted, a bottom mold 113 disposed under the mold, and a side mold 114 around the mold. Inside, a bottom material such as polyurethane or thermoplastic rubber is injected from the gate 116. The shock absorbing member 104 is placed in the cavity 115 in a state where it is placed on the bottom mold 113 in advance. The opening direction of the space 108 between the upper member 105 and the lower member 106 of the shock absorbing member 104 and the connecting portion that connects them in the vertical direction (at a position off the paper surface in the drawing) coincides with the injection direction by the gate 116. .

  The injection molding shoe molding method disclosed in Patent Document 2 will be described with reference to FIG. As shown in FIG. 21 (A), the first bottom material is injected and filled into the outer space 208 of the bottom mold 203 by the mold combination of the last mold 201 fitted with the cover, the side mold 202, and the bottom mold 203. Then, as shown in FIG. 21B, the bottom mold 203 is lowered to form a space portion 209 corresponding to the bottom. A second bottom material is injected into the space portion 209, and the space portion 209 is filled by foaming of the second bottom material, so that an injection-molded shoe integrally formed on the inner bottom 210 surface of the cover can be obtained. .

  However, in such a conventional shoe sole or injection molding method thereof, in the case of the first conventional example, when an insert such as the impact absorbing member 104 is installed in the injection space in advance, a predetermined volume is required. In the injection space, it is inevitable that the insertion in the full direction of travel obstructs the flow of the injection during injection. Therefore, in order to smoothly fill the injection space into the injection space, it is necessary to open the space 108 that matches the injection direction by the gate 116 in the shock absorbing member 104. For this reason, the shock absorbing member 104 has a complicated structure. In addition, there is a limit to the size of the insert within a predetermined volume of the injection space, and it was impossible to install a very large insert. In particular, it has been impossible to obtain a shoe sole in which the thickness of the insert is almost equal to the thickness of the shoe sole.

  In the second conventional example, the first bottom material is injected and filled into the outer space 208 of the bottom mold 203, and then the bottom mold 203 is lowered to form the space 209 corresponding to the bottom. Since the second bottom material is injected into the space portion 209 and the shoe sole is molded, the insert is not installed, but the injection material into the space portion 209 constituting the second bottom material is injected relatively smoothly. Became. However, in this molding method, it is necessary to wait for the first bottom material to harden after injection filling of the first bottom material into the space 208, and an increase in work time is inevitable. Furthermore, in such a conventional apparatus, there is a limit to the amount of injection material filled in the injection space of a predetermined volume, and if an attempt is made to fill the injection material beyond the volume of the injection space, a considerably high pressure is required. It was necessary to supply the ejected material at, which led to enlargement of the injection device.

  Therefore, the present invention solves the problems of the conventional shoe sole injection molding method, and can install an insert in a short time without using an injection device with a special structure having a high injection pressure function. It is an object of the present invention to provide a shoe sole injection molding method and apparatus capable of smoothly injecting an injection product and filling an injection product in an amount larger than a product molding volume, and an footwear manufactured by them.

For this reason, the technical means adopted by the present invention are:
An injection molding method in which an insert is placed in an injection direction in advance in an injection space configured by combining a lower mold or a last mold and a plurality of molds, and the injection is directly injected toward the injection space. In the injection space, the volume relationship between the insert and the injection product in the entire shoe sole or the heel part is linear from the injection product supply pipe to the toe direction. In addition, the insert is disposed so as to occupy the maximum width of the injection space in one or both of the vertical and horizontal sides of the sole of the final molded product, and the injection space is made larger or smaller than the product molding volume at the time of demolding. After the injection, the final product molding volume is obtained by controlling the volume of the injection space by sliding and moving the bottom mold that fits into the side mold through the injection space before demolding. This is an extrusion molding method.
Further, with respect to the insert disposed in the injection space , the insert is caused by self-melting of the insert satisfying the following relational expressions (1) and (2) or by melting of the coating covering the insert. 2. The shoe sole injection molding method according to claim 1, wherein the method is bonded to an injection product .
(1) Melting temperature of the insert ≤ maximum temperature in the mold of the injection
(2) The melting temperature of the covering of the insert ≦ the maximum temperature in the mold of the injection ≦ the melting temperature of the insert, or a shoe sole injection molding device used in the injection molding method, wherein the device is a last mold A side mold having an injection port for directly injecting the injection material toward the injection space, and a bottom mold slidable up and down in the side mold; An actuator that moves the bottom mold up and down, and the injection port is configured to directly inject an injection toward an injection space in a side mold; and the actuator further removes the injection from the injection space. After the injection is made with a size larger or smaller than the product molding volume, the bottom space that fits into the side mold is slid and moved until the mold is removed. Controlling a shoe sole injection molding apparatus, characterized in that finally to be able to obtain a product forming volume was.

  According to the present invention, in the injection molding method of injecting an injection material into the injection space after an insert is previously disposed in an injection space configured by combining a lower mold or a last mold and a plurality of molds, the injection After injecting the space larger or smaller than the product molding volume at the time of demolding, the injection space is changed until the demolding to finally obtain the product molding volume, thereby increasing the injection space at the time of injection of the injection product. In such a case, even if an insert with a relatively large volume (an insert that satisfies the relationship of the volume of the injection ≤ the volume of the insert is established), it is sufficient to surround the insert without being obstructed by the insert. As a result, the projectile goes around and smooth injection is possible without requiring high pressure. In addition, it is possible to freely control the molding by changing the injection space until the final product molding volume at the time of demolding is obtained. In addition, it is possible to fill an injection with an amount of injection exceeding the product molding volume. Moreover, when the injection space at the time of injection of the injection product is made smaller than that at the time of demolding, it is possible to appropriately promote and control the foaming degree of the foam injection product.

  In order to change the injection space, when the side mold is expanded or contracted or the bottom mold or the upper lower part or the last mold that fits in the side mold is moved, the side mold and the bottom mold or the upper lower part or the last mold are used. The front and rear, left and right of the injection space to be formed can be adjusted freely in the front and rear, left and right by following the expansion and contraction of the top and bottom and side modes by the bottom mold or upper lower part or last mold. It becomes. Furthermore, in order to change the injection space, when the bottom mold or upper lower part or the last mold that fits in the side mold is moved up and down, the bottom mold or the upper lower part or the last mold is moved up and down with certainty. It is possible to control the change of the injection space volume, and even when the insert is installed to the full width of the shoe sole, it is expanded vertically by lowering the bottom mold or raising the lower part of the upper or the last mold. The ejected material can be sufficiently filled through the relatively large injection space. And, when obtaining the final product molding volume at the time of demolding, the injection is effectively compressed by the rise of the bottom mold, and the insert is effectively compressed depending on the degree of the rise, so the injection is densely in the injection space. And the insert will be filled.

Moreover, the injection space insert disposed within, may give occupy a maximum width in aspect both or one of the largest of the sole of the final molded article as well as arranged in straight line from the injection Direction is final molded article of footwear Even if the inserts that occupy the bottom are arranged in a straight line in the injection direction and both vertically and horizontally or at the full width of one of them, the change in the injection volume during injection molding is not hindered by these inserts. By controlling this, the injection can be filled smoothly, and a shoe sole molded product composed of an injection molded product in which an insert having a sufficiently large volume ratio is arranged can be obtained. Furthermore, for the insert placed in the injection space, a relational expression (flow temperature of the insert ≦ highest temperature in the mold of the injection, or melting temperature of the coating of the insert ≦≦ mold of the injection the melting of the inner maximum temperature ≦ insert coating that covers the self-molten or insertion of establishment to insert the melting temperature) of, when the insert is bonded to the projectile, the surface or insert the insert itself By setting the coating to cover the mold lower than the maximum temperature in the mold of the injection and melting them to function as an adhesive, the insert is securely fixed in the injection and complete blind movement is achieved. To be prevented.

  In addition, in the shoe sole of the final molded product, when the volume relationship between the insert and the injection product in the entire shoe sole or the heel portion is such that the relationship of insert ≥ injection product is satisfied, the insertion in the entire shoe sole or the heel portion is performed. Even if an insert with a large volume exceeding half the volume ratio of the product is incorporated, the injection product can be filled smoothly by controlling the change in the injection space volume during injection molding. A hindrance or the like is not generated because the flow of a smooth projectile is hindered by the insert. Furthermore, the shoe sole injection molding apparatus used in the injection molding method includes a side mold having an injection port that holds the upper lower part at the upper part and communicates with an injection product supply pipe, and upper and lower parts that fit in the side mold. Side mold having an expansion chamber or the like by means of an apparatus having a movable bottom mold or upper lower part or last mold, an actuator for expanding and contracting the side mold, and an actuator for vertically moving the bottom mold or upper lower part or last mold. The above-described unique sole of the present invention can be achieved even at a low injection pressure without using an injection device of a special structure, only by a device having a simple structure such as expansion / contraction of the bottom mold or upper / lower movement of the upper lower part or the last mold. The molding method can be realized.

  Furthermore, when the side mold is divided into a plurality of parts, an injection port can be formed on the divided surface, which makes it easy to remove and clean the injection material in the injection port after curing, and to separate the product. The mold is also easy. Moreover, when receiving the bottom mold, by adjusting the gaps between the divided surfaces of the plurality of side molds, the increase in the gap between the divided surfaces of the divided side molds during expansion / contraction can be accommodated by packing, grease, etc. The accuracy between the upper and lower sliding surfaces of the inner peripheral surface of the mold and the outer peripheral surface of the bottom mold can be finely adjusted appropriately, and volume adjustment on the front and rear sides and the left and right sides of the injection space is facilitated. Further, the shoe sole manufactured by the shoe sole injection molding method or the shoe sole injection molding apparatus and the shoe equipped with the shoe sole can significantly increase the volume of the insert with respect to the shoe sole. The properties of the insert that cannot be seen in can be extracted. By forming the insert at that time in a separate process in advance, it is less affected by the injection and increases the flexibility in designing the sole characteristics.

  Further, the shoe sole of the footwear manufactured by the shoe sole injection molding method or the shoe sole injection molding apparatus has the density of each part with respect to the average density of the injection product from the start point to the end point in the injection direction of the injection product. If there is variation, there is no variation in average density due to the fact that the injection pressure of the conventional one has to be high, there is no inconvenience that there is no difference in the elastic modulus of each part of the shoe sole, relatively A low-density injection-molded part can be obtained particularly in the collar part close to the injection part due to the low injection pressure. Furthermore, when the shoe sole of the footwear manufactured by the shoe sole injection molding method or the shoe sole injection molding apparatus has a measurement value of 29 J or more according to the JIST 8101: 1997 heel impact absorption measurement method, An insert that occupies most of the properties at a required site, such as a section, can occupy many portions of the shoe sole as having a suitable shock absorption measurement.

  The best mode for carrying out the present invention will be described below with reference to the drawings. FIGS. 1 to 4 show one embodiment of a shoe sole injection molding method and apparatus according to the present invention. FIG. 1 is a partial sectional view of the entire side of the injection molding apparatus during injection, and FIG. 2 is a product molding volume. FIG. 3 is an exploded side view of the entire mold, FIG. 4 is an exploded view of each mold, FIG. 4 is a plan view and a side view of the side mold and the bottom mold, and FIG. 6 is a cross-sectional view of an example of insertion of an insert, FIGS. 7 and 8 are perspective views of other inserts, FIG. 9 is a perspective view of a part of a covered insert, and FIGS. FIG. 17 is a cross-sectional photographic view of an example of a shoe sole formed by the injection molding method of the present invention. As shown in FIG. 1, the basic configuration of the present invention is that the inserts 9 </ b> A and 9 </ b> B are arranged in advance in an injection space 7 configured by combining a lower portion of the upper 4 and a plurality of molds 1 and 2. In an injection molding method for injecting an injection product 8 into an injection space 7, after the injection space 7 is injected with a size larger or smaller than a product molding volume at the time of demolding, the injection space 7 is changed before demolding. Finally, a product molding volume is obtained.

  Each mold (mold) is disassembled as shown in FIG. An upper (cover) is installed by being attached to the last mold 3 constituting the foot mold, and the side mold 1 is installed around the lower upper part. A space in which an injection space 7 is formed is formed inside the side mold 1, and the bottom mold 2 is inserted so as to be movable up and down in conformity with the space. An outsole 10 serving as a back surface of a shoe sole is laid on the upper surface of the bottom mold 2. Inserts 9 </ b> A and 9 </ b> B are placed in advance in the injection space 7, and an insole 30 is set at the lower portion of the upper 4 above the side mold 1.

  As understood from FIG. 4 (A), the side mold 1 of the present embodiment is divided into two parts 1A and 1B at a substantially central part. On this dividing surface, an injection port 5 for supplying the injection material from the injection material supply pipe 6 into the injection space 7 is formed. Reference numerals 12 and 13 denote first and second restraining arms that restrain the upward movement of the side mold 1. FIG. 4B is a cross-sectional view of the side mold 1 on the dividing surface, and shows an injection port 5 formed on the dividing surface. In addition to simplifying the removal and cleaning of the injection in the injection port 5 after curing, the product can be easily released. In addition, when the bottom mold 2 shown in FIG. 4C is received, the gap between the divided surfaces of the plurality of side molds 1A and 1B is adjusted to increase the gap between the divided surfaces of the divided side molds during expansion / contraction. Correspondingly with packing, grease, etc., it becomes possible to finely adjust the accuracy between the upper and lower sliding surfaces of the inner peripheral surfaces of the side molds 1A and 1B and the outer peripheral surface of the bottom mold 2 appropriately. FIG. 4D is a cross-sectional view of the bottom mold 2. Further, in order to adjust the volume of the injection space by the side mold, for example, an expansion chamber is provided outside the injection space, and a polymerization inner wall that slides relative to the injection space is provided. It is conceivable to increase / decrease the injection space in the side mold with the actuator by configuring the actuator by taking in and out.

  Returning to FIG. 1, first and second support legs 14, 15 provided on the bottom surface of the side mold 1 formed by integrating the integrated or divided side molds 1 </ b> A, 1 </ b> B at four corners of the base 11. It is mounted on and supported by. On the upper surface of the side mold 1, the upper ends of the first and second restraining arms 12 and 13 that are pivotally supported by the hinges 23 and 24 are engaged with both ends of the base 11. As a result, the vertical position of the side mold 1 is reliably restrained and regulated. A space in which an injection space 7 is formed is formed inside the side mold 1, and the bottom mold 2 is inserted so as to be movable up and down in conformity with the space. Between the lower surface of the bottom mold 2 and the pedestal 11, first and second jacks 16 and 18 constituting a hydraulic actuator are disposed. The first and second pistons 17 and 19 extend from the jacks 16 and 18 so as to freely move up and down. First and second stroke meters 21 and 22 are installed on the upper surfaces of the jacks 16 and 18, and the forward and backward strokes of the pistons 17 and 19 with appropriate scales can be measured.

  The side mold 1 is formed with an injection port 5 for supplying an injection 8 from the injection supply pipe 6. If the side mold 1 is a split type, it is preferable that the injection port 5 having a circular cross section is formed by combining a semicircular cross section passage formed on each split surface. By forming the injection port on the divided surface, it becomes easy to remove and clean the injection material in the injection port after curing, and also to release the product. A plurality of injection ports 5 may be formed. In that case, it can be confirmed whether or not the shoe sole into which the insert has been inserted is inserted from the state in which the molding volume is widened, depending on the position of the injection port. A flow meter 20 capable of measuring the flow rate of the ejected material 8 is installed in the ejected material supply pipe 6, and the supply amount of the ejected material 8 to the ejection space 7 can be controlled by feedback of the measurement result.

  In order to inject the injection 8 into the injection space 7 and start molding of the shoe sole, the pistons 17 and 19 of the jacks 16 and 18 are retracted and the bottom mold 2 is lowered, so that the injection space is sufficiently wide. 7 is secured. At this time, an outsole 10 serving as the back surface of the shoe sole is laid on the upper surface of the bottom mold 2, and inserts 9 </ b> A and 9 </ b> B that determine the shock absorption characteristics of the shoe sole are placed at appropriate positions in the injection space 7. Placed. Further, an insole 30 is placed at the top in the injection space 7. In this state, the liquid injection material 8 is supplied from the injection material supply pipe 6 through the injection port 5. The projectile 8 exiting the ejection port 5 flows smoothly around the inserts 9A and 9B as shown by arrows in a sufficiently large injection space 7 in the vertical direction. Therefore, according to the present invention, it is possible to easily mold the sole so that the volume of the insert 9 which has been impossible in the past exceeds 50% (relative to the volume of the injection 8).

  FIG. 17 is a cross-sectional photograph of an example of a shoe sole formed by the injection molding method of the present invention. It is understood that the volume of the insert 9 (white part of the photograph) occupies a considerable part in the shoe sole. It should be noted that the projecting material may enter the groove formed at the upper part of the intermediate position of the insert, and the projecting material that has entered the groove may prevent the insert from moving back and forth. Such a movement preventing structure can be easily molded according to the present invention even when the thickness of the insert is large.

  As the insert 9 that determines the impact absorption characteristics and the comfort performance of the shoe sole, various materials can be employed. For example, EVA, polyurethane (polyester polyurethane, polyether polyurethane), vinyl chloride resin, rubber, wood, TPU, pulp, metals, ceramics, various plastics, olefinic resins, non-foamed materials such as FRP, and the like (above) Such as foam. Furthermore, a woven fabric, a nonwoven fabric, leather, glass fiber, carbon fiber, aramid fiber, etc. may be sufficient. It may be a magnet or ore or a whole insert. It may be an electronic device protected in the form of a cell that does not affect the projectile, an evacuation tool such as food and feces, an air bag, an object inserted into an air bag, or a cell filled with water or oil. The insert may or may not be conductive.

  The shape of the insert may be anything as long as it can be controlled in the molding space controlled by the side mold, the bottom mold, and the last mold as shown in FIGS. There are a plurality of different materials, a structure composed of a plurality of laminated bodies, a connection of different materials, and the like. Further, the insert may be buried in the injection product in the finished product or may be partially exposed from the shoe sole. The insert may be partially exposed from the bottom of the finished product (1 in FIG. 7) or protruded. Further, as shown in 2, 3, and 4 in FIG. 7, a foreign substance such as a cavity into which the injection enters and a conductive material can be inserted.

  As shown in FIG. 8, the insert 9 may be configured to occupy the maximum width at the maximum and / or width of the sole of the final molded product. In the present invention, even if these inserts are arranged to the full width of the shoe sole, the arrangement is such that the flow of the ejected matter is obstructed by the protrusion on the side surface of the insert as shown in FIG. However, since it is possible to control the change in the volume of the injection space during injection molding, it is possible to fill the injection smoothly, and the shoe sole is made of an injection molding in which an insert having a sufficiently large volume ratio is arranged. A molded product can be obtained. In this way, in the shoe sole of the final molded product, a large insert is arranged such that the volume relationship between the insert and the injection in the entire shoe sole or the heel portion is such that the relationship of insert ≧ injection is established. In other words, even if an insert with a large volume such that the volume ratio of the insert in the entire shoe sole or heel exceeds half is filled, the injection can be filled smoothly by controlling the change in the injection space volume during injection molding. Therefore, unlike conventional ones, the insertion of a large volume is hindered and the flow of a smooth projectile is hindered, and a nest or the like is not generated.

In addition, as shown in FIG. 9, for the insert placed in the injection space, the relational expression (the melting temperature of the insert ≦ the maximum temperature in the mold of the injection, or the melting temperature of the coating of the insert) If the insert is bonded to the injection by self-melting of the insert that satisfies the following condition : the maximum temperature in the mold of the injection or the melting temperature of the insert, the insert Reliable fixing of the insert in the injection by setting the coating covering its surface or insert below the maximum temperature in the mold of the injection and melting them to function as an adhesive And blind movement can be completely prevented.

  Examples of the injection 8 include EVA, polyurethane (polyester polyurethane, polyether polyurethane), vinyl chloride resin, rubber, TPU, pulp, various elastomers and elastomers, non-foamed materials such as olefin resins, and foams thereof. Moreover, you may use what added the granular mixture by using the said injection thing as a binder component. Further, the shoe sole is a two-layer bottom provided with the outsole 10 (the outsole 10 and the insert 9 and the projectile 8 constituting the midsole), but the one-sole bottom (the insert 9 and the midsole that excludes the outsole 10). The projectile 8) constituting the sole may be used. Even if the insert is arranged in any position in the multicolor multilayer molding, a plurality of layers may be provided in which the insert is arranged in each layer having a multilayer structure.

  When the injection of the injection material into the injection space 7 is completed, the bottom mold 2 is raised by moving the pistons 17 and 19 of the jacks 16 and 18 as shown by the arrows in FIG. The ascending control is determined by a control means (not shown) based on the measured values of the stroke meters 21 and 22 that measure the travel strokes of the pistons 17 and 19. When the bottom mold 2 increases a predetermined movement amount or the side mold 1 is contracted, the injection 8 and the inserts 9A and 9B that are being cooled and hardened are compressed to have a predetermined product molding volume. Cured with.

  If the upward movement amount of the bottom mold 2 based on the measurement values obtained by the stroke meters 21 and 22 is appropriately set, it is possible to appropriately set the sole characteristics by adjusting the compression rate of the sole. Conversely, when the injection space at the time of injection of the injection product is made smaller than that at the time of demolding, that is, after the injection material is being cured in the injection space smaller than the product molding volume, By lowering the bottom mold 2 or enlarging the side mold 1 to increase the injection space, it is possible to appropriately promote and control the degree of foaming of the foam injection product.

  FIG. 18 shows the shoe soles of footwear manufactured by the shoe sole injection molding method or the shoe sole injection molding apparatus according to the present invention, with respect to the average density of the injection products from the start point to the end point in the injection direction of the injection products. It is a table of a comparison experiment result with the conventional thing which showed that the variation beyond a predetermined value could be produced in the density of a part. In the conventional Nos. 1 and 2 with no insert, there is a relatively large variation in each part. However, in Nos. 6, 7 and 8 according to the conventional method with an insert, since there is an insert, the injection is sufficiently distributed. In contrast, there is no nest, the filling pressure of the injection must be increased, and there is no variation in the average density, whereas the insert was inserted into the stepping, stepping, and buttocks In Nos. 3, 4, and 5 manufactured by the method of the present invention, the injection material was sufficiently distributed to each part without the injection pressure of the low injection material and the formation of the nest, despite the presence of the injection material. Variations of 0.37 to 0.49 are observed with respect to the densities of 0.41 to 0.42. That is, a variation of about a predetermined value ± 10 to 20% with respect to the entire average density was observed. Thereby, in the foamable injection material and the foamed injection material having the density distribution, the amount of the injection material can be molded with the minimum amount. Without changing the molding space, it is possible to mold shoes and soles in which the density required for each part varies in the same manner as the density distribution of a normal shoe sole without an insert for injection molding.

  FIG. 19 shows that the shoe sole of footwear manufactured by the shoe sole injection molding method or the shoe sole injection molding apparatus according to the present invention has a measured value of 29 J or more according to the JIST 8101: 1997 heel impact absorption measurement method. It is a table of a comparison experiment result with the conventional thing which shows being comprised. According to the method of the present invention, it is possible to insert an insert that exceeds 50% of the total volume of the sole, so that the overall shock absorption is governed by the intrinsic shock absorption characteristic value of the insert (or , The shock absorption per volume of the entire measurement site is governed by the inherent shock absorption of the insert). The factor of the measurement result of the buttocks shock absorption depends on the amount of shock absorption of the measurement object installed in the measurement system and the shock absorption. In this experiment, 7mm made of rubber as the outsole, 27mm made of EVA as the insert, foam layer hardness 64 (Asuka-C hardness meter), non-woven fabric 1.5mm as the insole, the insert has the maximum final molding height Molded. As the injection, polyester polyurethane was used, and as a conventional comparative example, the same injection was used (no insert).

  A shoe sole into which a large amount of insert has been inserted at the measurement site is not governed by the impact absorbability of the outsole or insole, but is governed by the buttocks impact absorbability of the majority of the insert. This can be understood by considering the substance between the measurement system connecting the power point and the load cell when measuring the hip impact absorption. If the three arrangements of outsole, insert and insole are in the vertical direction, in volume relation, if insert >> outsole + insole, the shock absorption characteristics of the insert will make the overall shock absorption Properties are governed. Or insert> outsole + insole. In the present invention, since it is possible to appropriately place the insert from the maximum value on the buttocks and other parts so as to obstruct the injection path, it depends on the inherent shock absorption property of the insert in the injection molding method that was impossible in the past. It is now possible to manufacture shoes.

  As described above, when the insert 9 is installed without being fixed when the injection 8 is injected into the injection space 7, as shown in FIG. 1, the last in which the bottom mold 2 and the upper 4 are mounted is provided. The insert 9 is only fixed or inserted by the mold 3. In this state, for example, even if the foamable injection 8 is injected, after the injection is performed from the position where it directly collides, if the bottom mold or the like is lowered to increase the molding volume, the foamed injection 8 is pushed. The insert 9 moves. This is an effective method when the insert 9 is sandwiched (floated) by the projectile 8 even if there is no fixed object or the like of the insert 9. In addition, the insert 9 is molded so as to be sandwiched between the injection products by changing the molding volume by lowering the bottom mold 2 after the injection product 8 is injected. If the molding volume is increased after performing the above, the insert becomes an effective method when moving forward (toe).

  10 to 16 are a plan view and a cross-sectional view showing an injection molding example of the present invention compared with a conventional one. In these figures, the left side of the drawing is based on the injection molding method according to the present invention, and the right side of the drawing is based on the conventional injection molding method. As shown in FIG. 10, the insert is placed in the injection space, and then the injection is injected from the buttock side. In the present invention, the bottom mold is lowered to ensure a large injection space. Conventionally, the bottom mold is in place. In the present invention, the injection is smoothly and sufficiently distributed even at a low filling pressure regardless of the presence of a large insert.

  In the present invention, after the injection material is injected, the injection material is sufficiently spread around the insert by raising the bottom mold as shown in FIG. As shown in FIG. 12, after the bottom mold has reached the product position, the injection and the insert are compressed and cured at a predetermined product forming volume while the injection is cooled and cured. In the conventional one, there is a possibility that the injection material does not sufficiently spread around the insert and is cooled and hardened. FIG. 13 shows a state where the injection material is foamed and molded between the side molds on both sides of the insert. FIG. 14 shows an example in which an insert of a type having a groove in the central longitudinal direction is arranged. In the conventional example, the injection product is pushed out through the groove in the central longitudinal direction, whereas in the present invention, the bottom mold is lowered. As a result, a sufficiently large injection space can be secured, and the state in which the injection product is first pushed out through the groove in the central longitudinal direction below the insert is shown.

  15 and 16 show an example in which an insert of a type having a groove in the central longitudinal direction is arranged. As shown in FIG. 15, in the present invention, since the bottom mold is lowered, a sufficiently large injection space can be secured, and the groove in the longitudinal direction of the center, not to mention the groove around the insert, can be sufficiently obtained from the front and back of the insert. You can make the projectile go around. On the other hand, in the conventional one, since the ejected material is pushed out through the groove in the central longitudinal direction, there is a possibility of forming a nest where the ejected material does not spread on both sides of the insert. As shown in FIG. 16, in the present invention, by raising the bottom mold to the product position, the injection material is sufficiently distributed around the insert, including the front and back, to form a uniform and high-quality shoe sole. be able to. In addition, at that time, an injection-molded part having a low density can be obtained particularly in the collar part close to the injection part due to the relatively low filling pressure of the injection.

  The embodiment of the present invention has been described above, but within the scope of the present invention, the shape and type of the upper, the shape and type of the last mold to which the upper is mounted, the form of mounting the upper to the last mold, and the side Mold shape and type (symmetrical two-part type, asymmetric type, one-piece type, etc. In addition to the side mold, the side mold includes an expansion chamber and a sliding inner wall. Etc.) and injection port formation form (position of injection port, for example, combination on split surfaces such as toes and side surfaces, not limited to the heel side), shape and type of bottom mold , Related configuration of side mold and bottom mold, installation form on side mold around upper lower part (appropriate form to keep tightly sealed around lower upper part can be adopted , The shape of the insert (thickening the buttock, installing it in the width direction, or extending it forward, also with different materials, etc.), type and material (EVA, Non-foamed materials such as polyurethane, vinyl chloride resin, rubber, TPU, pulp, various plastics and the like, and the like can be appropriately selected.

  In addition, the shape and type of the injection and its material (EVA, polyurethane, vinyl chloride resin, rubber, TPU, pulp, various plastomers, non-foamed materials such as elastomers and foamed materials), and the injection device up to the injection supply pipe Shape, type, shape of injection space (various shapes based on shoe sole pattern etc. are adopted), type, installation form of insert in injection space (just place it on the bottom mold upper surface or upper lower surface Fixing by appropriate means, etc.) Ratio of injection space volume to product molding volume, volume change form of injection space (preferably vertical movement of bottom mold, but in combination with vertical movement of bottom mold, The means that can reduce the diameter and the bottom mold are fixed or moved up and down, the last mold moved up and down, and the last mold fitted with the upper moved up and down. ), The shape and type of the actuator (hydraulic pressure, pneumatic pressure, electromagnetic force, mechanical jacks composed of pistons / cylinders, etc. The number of actuators such as jacks is also provided by a pair of front and rear. The thickness of the soles before and after or the degree of foaming can be finely adjusted). The specifications described in the examples are merely examples in all respects and should not be interpreted in a limited manner.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows one embodiment of a shoe sole injection molding method and apparatus of the present invention, and is a partial side sectional view of an entire injection molding apparatus during injection. FIG. 4 is a partial side sectional view of the entire injection molding apparatus with the bottom mold raised to obtain a product molding volume. It is an exploded view of each mold. It is each plane and side view of a side mold and a bottom mold. It is sectional drawing of the example of insertion of an insert same as the above. It is sectional drawing of the example of insertion of an insert same as the above. It is sectional drawing or a perspective view of other inserts same as the above. It is a perspective view or a top view of other inserts. It is a perspective view of partial cutting of the coated insert. It is the top and sectional view showing the example of injection molding of the present invention compared with the conventional one. It is the top and sectional view showing the example of injection molding of the present invention compared with the conventional one. It is the top and sectional view showing the example of injection molding of the present invention compared with the conventional one. It is the top and sectional view showing the example of injection molding of the present invention compared with the conventional one. It is the top and sectional view showing the example of injection molding of the present invention compared with the conventional one. It is the top and sectional view showing the example of injection molding of the present invention compared with the conventional one. It is the top and sectional view showing the example of injection molding of the present invention compared with the conventional one. It is a cross-sectional photograph figure of the example of a shoe sole shape | molded by the injection molding method of this invention. It is an experiment result table figure which compared the dispersion | variation in the density of each part of the shoe sole of the footwear manufactured by this invention with the conventional one. It is an experimental result table | surface figure compared with the conventional thing of the impact absorption characteristic of the shoe sole of the footwear manufactured by this invention. It is sectional drawing which shows the shaping | molding method of the shoe sole of a 1st prior art example. It is sectional drawing which shows the shaping | molding method of the injection molding shoes of a 2nd prior art example.

Explanation of symbols

1 Side mold (mold)
2 Bottom mold
3 Last mold (foot type)
4 Upper
5 Injection Port 6 Projected Product Supply Pipe 7 Injection Space 8 Projected Product 9 Insert 10 Outsole 16 First Jack 18 Second Jack 30 Middle Bottom

Claims (3)

An injection molding method in which an insert is placed in an injection direction in advance in an injection space configured by combining a lower mold or a last mold and a plurality of molds, and the injection is directly injected toward the injection space. ,
Within the injection space, there is a volume relationship between the insert and the injection in the entire shoe sole or heel.
Insert ≥ projectile
The insert satisfying the above relationship is arranged linearly in the toe direction from the injection product supply pipe and so that the insert occupies the maximum width of the injection space in both the vertical and horizontal directions of the shoe sole of the final molded product. ,
After injection with the injection space larger or smaller than the product molding volume at the time of demolding, the volume of the injection space is controlled by sliding the bottom mold that fits the injection space into the side mold before demolding. A shoe sole injection molding method characterized in that a final product molding volume is obtained. With respect to the insert disposed in the injection space , the insert is injected by self-melting of the insert satisfying the following relational expressions (1) and (2) or by melting of the coating covering the insert. The shoe sole injection molding method according to claim 1, wherein the shoe sole is injection-molded.
(1) Melting temperature of the insert ≤ maximum temperature in the mold of the injection
(2) Melting temperature of the covering of the insert ≦ maximum temperature in the mold of the injection ≦ melting temperature of the insert A shoe sole injection molding apparatus used in the injection molding method according to any one of claims 1 and 2, wherein the apparatus grasps the last mold at the upper part and communicates with the injection product supply pipe, and the injection product A side mold having an injection port that directly injects into the injection space; a bottom mold that can slide up and down within the side mold; and an actuator that moves the bottom mold up and down. The actuator is configured to be able to directly inject toward the injection space in the side mold, and the actuator further injects the injection material with the injection space being made larger or smaller than the product molding volume at the time of demolding and before demolding. The bottom mold that fits into the side mold in the injection space is slid and moved to control the volume of the injection space so that the final product molding volume can be obtained. Sole injection molding apparatus characterized by the.

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