JP6263975B2 - Blow mold for plastic bottle - Google Patents

Description

  The present invention relates to a blow molding mold for plastic bottles, and more particularly to a blow molding mold for plastic bottles that can reduce the manufacturing cost and can be easily handled.

  Recently, plastic bottles have become common as beverage bottles, and such plastic bottles are equipped with a preform in a blow mold and blow-molded against the preform. Is obtained.

  By the way, the blow mold for manufacturing the plastic bottle has a body mold corresponding to the body of the plastic bottle, a bottom mold corresponding to the bottom, and a neck mold corresponding to the neck.

  These body molds, bottom molds, and neck molds are generally formed in one piece. From the body mold, the bottom mold, and the neck mold according to the shape of the plastic bottle. As a whole, the blow mold is exchanged as a whole.

  As described above, the body part mold, the bottom part mold, and the neck part mold constituting the blow molding mold are integrally formed, and the entire blow molding mold is replaced every time the shape of the plastic bottle is changed. In reality, the manufacturing cost of blow molding dies is high. In addition, it is also required to simply store unused blow molding dies.

  The present invention has been made in view of the above points, and is a plastic that can be easily replaced when it is not used and can be easily stored when not in use. An object is to provide a blow mold for bottles.

  The present invention relates to a plastic bottle blow for blow molding a plastic bottle having a trunk, a bottom below the trunk, a mouth above the trunk, and a neck located between the trunk and the mouth. The mold includes a body mold corresponding to the body of the plastic bottle, a bottom mold corresponding to the bottom of the plastic bottle, and a neck mold corresponding to the neck of the plastic bottle. A first cooling mechanism is provided, and the body mold includes an inner body mold whose inner surface is defined corresponding to the outer surface of the body part, and an outer shell positioned outside the inner body mold, The inner body mold of the body mold can be exchanged from the outer shell corresponding to the shape of the plastic bottle, and the first cooling mechanism has a cooling flow path extending through the neck mold, and is first in plan view. The cooling flow path of the cooling mechanism should overlap the inner body mold. A plastic bottle blow molding mold according to claim.

  According to the present invention, the bottom mold includes an outer bottom mold, and an inner bottom mold that is supported by the outer bottom mold and has an inner surface defined corresponding to the outer surface of the bottom of the plastic bottle. A blow molding mold for plastic bottles, wherein a second cooling mechanism is provided in the mold and the inner bottom mold.

  The present invention is the blow molding die for plastic bottles characterized in that an enclosure is further provided outside the outer shell.

  The present invention is a blow molding mold for plastic bottles characterized in that a heating mechanism is provided in the enclosure.

  The present invention is a blow mold for plastic bottles, wherein the outer shell is engaged with the bottom mold.

  In the present invention, the first cooling mechanism has an inlet and an outlet that communicate with the cooling channel, and the cooling channel of the first cooling mechanism includes an inlet-side cooling channel that communicates with the inlet, and inlet-side cooling. An outlet side cooling channel that is continuous with the channel and communicates with the outlet, and at least one of the inlet side cooling channel and the outlet side cooling channel overlaps the inner body mold in plan view This is a blow molding mold for plastic bottles.

  The present invention is the blow molding mold for plastic bottles, wherein both the inlet side cooling flow path and the outlet side cooling flow path overlap with the inner body mold in a plan view.

  The present invention is the blow mold for plastic bottles, wherein the inlet side cooling channel and the outlet side cooling channel have a crescent shape in plan view.

  The present invention is the blow molding mold for plastic bottles, wherein each of the inlet side cooling channel and the outlet side cooling channel includes a plurality of linear portions.

  The present invention is the blow mold for plastic bottles characterized in that a branch portion is connected to a straight portion of the inlet side cooling channel or the outlet side cooling channel.

  The present invention is a blow molding mold for plastic bottles characterized in that a heat insulating space is formed between a neck mold and an inner body mold.

  According to the present invention, the body mold includes an inner body mold and an outer shell located outside the inner body mold, and the inner body mold corresponds to the shape of the plastic bottle. It can be exchanged from the outer shell. Therefore, when the shape of the plastic bottle changes, only the inner body mold of the body mold may be removed from the outer shell and replaced. Thus, it is not necessary to replace the blow molding die as a whole every time the shape of the plastic bottle changes, and the manufacturing cost of the blow molding die can be reduced.

FIG. 1 is a front view showing an embodiment of a blow molding mold for plastic bottles according to the present invention. FIG. 2A is a front view showing a trunk mold and a neck mold, and FIG. 2B is a front view showing an inner trunk mold. FIG. 3A is a view showing an outer bottom mold, and FIG. 3B is a view showing an inner bottom mold. 4 is a cross-sectional view taken along line IV-IV in FIG. FIG. 5 is a front view showing a plastic bottle obtained from a blow mold according to the present invention. FIG. 6 is a bottom view showing the plastic bottle. FIGS. 7A, 7B, and 7C are views showing an arrangement relationship among the neck mold, the first cooling mechanism, and the inner body mold. FIG. 8 is a perspective view showing an arrangement relationship between the first cooling mechanism and the inner body mold. FIG. 9A is a plan view showing the positional relationship between the first cooling mechanism and the inner body mold, and FIG. 9B is a perspective view thereof. FIG. 10A is a side sectional view showing the neck mold and the first cooling mechanism, and FIG. 10B is a sectional view showing the arrangement relationship between the neck mold, the first cooling mechanism, and the inner body mold. . FIG. 11 is a cross-sectional view showing a heat insulating space formed between the neck mold and the inner body mold.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 1 to 4 are views showing an embodiment of the present invention.

  First, the plastic bottle 10 obtained by the blow molding mold for plastic bottles according to the present invention will be described with reference to FIGS. The plastic bottle 10 is obtained by blow molding using a blow molding die 30 to be described later. The plastic bottle 10 has a mouth portion 11, a body portion 20 provided below the mouth portion 11, and a body portion 20. The bottom part 30 provided below is provided.

  Among these, the trunk | drum 20 has several, for example, four side surfaces 21 which consist of mutually the same shape, and consists of a substantially polygonal cylinder shape, for example, a square cylinder shape as a whole. Further, a flat boundary surface 22 is formed between the adjacent side surfaces 21. Further, a shoulder portion 12 constituting a part of the trunk portion 20 is formed between the side surface 21 and the boundary surface 22 and the mouth portion 11.

  Moreover, the four side surfaces 21 of the trunk | drum 20 are divided into the upper area | region 21a and the lower area | region 21b through the side surface horizontal concave rib 24a drawn inward (inward of the bottle 10). Each boundary surface 22 is also divided into an upper region 22a and a lower region 22b via a boundary surface horizontal concave rib 24b that is drawn inward (inward of the bottle 10).

  Among these, the horizontal concave rib 24 is comprised by the side surface horizontal concave rib 24a and the boundary surface horizontal concave rib 24b.

  Further, a flat panel portion 23 is provided in each of the upper region 21a and the lower region 21b of each side surface 21 of the trunk portion 20, and the panel portion 23 allows the plastic bottle 10 to be inflated and decompressed. Absorbs the applied pressure.

  Further, a neck portion 15 that is pulled inward is formed between the shoulder portion 12 and the mouth portion 11 of the trunk portion 20.

  Furthermore, the bottom portion 25 has a peripheral edge portion 26 and a central portion 27 located at the center of the peripheral edge portion 26 and lifted upward from the peripheral edge portion 26.

  Such a plastic bottle 10 can be produced by biaxially stretching blow-molding a preform produced by injection molding a synthetic resin material using a blow molding die. In addition, it is preferable to use a thermoplastic resin, especially PE (polyethylene), PP (polypropylene), PET (polyethylene terephthalate), PEN (polyethylene naphthalate) as a material of the preform, that is, the plastic bottle 10.

  The plastic bottle 10 can also be formed as a multilayer molded bottle having two or more layers. That is, by extrusion molding or injection molding, for example, the intermediate layer has gas barrier properties and light shielding properties such as MXD6, MXD6 + fatty acid salt, PGA (polyglycolic acid), EVOH (ethylene vinyl alcohol copolymer) or PEN (polyethylene naphthalate). A multilayer bottle having gas barrier properties and light shielding properties may be formed by extrusion molding a preform composed of three or more layers as the resin (intermediate layer), and then blow molding.

  Further, by mixing an inert gas (nitrogen gas, argon gas) with the thermoplastic resin melt, a foam preform having a foam cell diameter of 0.5 to 100 μm is formed, and this foam preform is blow-molded. As a result, the plastic bottle 10 may be manufactured. Since such a plastic bottle incorporates the foam cell, the light shielding property of the entire plastic bottle 10 can be improved.

  Moreover, in order to have gas barrier property and light-shielding property, you may form not only a multilayer but the blend bottle which blended thermoplastic resins.

  Next, a plastic bottle blow molding die 30 according to the present invention will be described with reference to FIGS.

  The plastic bottle blow molding die 30 corresponds to the barrel die 31 corresponding to the barrel 20 of the plastic bottle 10, the bottom die 35 corresponding to the bottom 25 of the plastic bottle 10, and the neck 15 of the plastic bottle 10. A neck mold 38 is provided.

  Among these, the body part mold 31 includes an inner body part mold 32 in which an inner surface 32 a is defined corresponding to the outer surface of the body part 20, and an outer shell 33 positioned outside the inner body part mold 32. Each of the inner body mold 32 and the outer shell 33 has a split surface that is split into two in the longitudinal direction.

  The bottom mold 35 includes an outer bottom mold 36 and an inner bottom mold 37 that is supported by the outer bottom mold 36 and has an inner surface 37a defined corresponding to the outer surface of the bottom 25 of the plastic bottle 10. ing.

  The neck mold 38 is provided with a first cooling mechanism 38A including a cooling water inlet 38a and a cooling water outlet 38b, and the inlet 38a is connected to a cooling flow path 38c provided in the neck mold 38. The neck mold 38 can be effectively cooled by flowing the cooling water from the outlet and discharging the cooling water from the outlet 38b.

  Next, the positional relationship among the neck mold 38, the first cooling mechanism 38A provided in the neck mold 38, and the inner body mold 32 will be described with reference to FIGS. 7 (a), 7 (b), and 7 (c).

  7A is a plan view showing the first cooling mechanism 38A, and FIG. 7B is a plan view showing the arrangement relationship between the neck mold 38 and the first cooling mechanism 38A. (C) is a top view which shows the arrangement | positioning relationship between 38 A of 1st cooling mechanisms and the inner side body part mold | die 32. FIG.

  As shown in FIGS. 7A, 7B, and 7C, the first cooling mechanism 38A includes a cooling water inlet 38a, an outlet 38b, and a cooling channel 38c provided in the neck mold 38. Have.

  In this case, the cooling flow path 38c of the first cooling mechanism 38A overlaps with the inner body mold 32 in plan view.

  Thus, in plan view, the cooling flow path 38c of the first cooling mechanism 38A overlaps with the inner body mold 32, so that the neck mold 38 can be reliably cooled by the first cooling mechanism 38A. That is, when the cooling flow path 38c for cooling the neck mold 38 is separated from the inner trunk mold 32 in plan view, the enclosure 40 and the outer shell 33 with water, pressurized water, or oil that has been temperature-controlled as will be described later. When the inner body mold 32 is heated, it becomes difficult to sufficiently cool the neck mold 38 by the heat from the inner body mold 32. On the other hand, according to the present embodiment, since the cooling flow path 38c overlaps with the inner body mold 32 in plan view, even if the neck mold 32 is slightly heated by the inner body mold 32, The neck mold 38 can be reliably cooled by the cooling water flowing through the cooling flow path 38c.

  Further, the outer bottom mold 36 and the inner bottom mold 37 are provided with a second cooling mechanism 36A including a cooling water outlet 36a and a cooling water outlet 36b, and the outer bottom mold 36 and the inner bottom mold 36 are provided. The cooling water (not shown) in 37 is introduced into the cooling water from the inlet 36a, and the cooling water is discharged from the outlet 36b, thereby effectively cooling the outer bottom mold 36 and the inner bottom mold 37. can do.

  Furthermore, the lower end portion of the outer shell 33 of the body mold 31 is engaged with the outer bottom mold 36.

  Furthermore, as shown in FIGS. 1 and 4, an enclosure 40 surrounding the outer shell 33 is further provided outside the outer shell 33 of the body mold 31. A temperature control medium flow path 40A into which temperature-controlled water, pressurized water, or oil flows is formed in the enclosure 40, and the temperature is adjusted from the inlet 40a into the temperature control medium flow path 40A of the enclosure 40. Water, pressurized water or oil flows in, and the temperature-controlled water, pressurized water or oil flowing into the temperature control medium flow path 40A heats the enclosure 40 and is then discharged outward from the discharge port 40b. The enclosure 40 has a dividing surface that is divided into two in the vertical direction.

  By the way, the trunk part mold 31 includes the inner trunk part mold 32 and the outer shell 33 located outside the inner trunk part mold 32, so that the inner trunk part mold 32 is separated from the outer shell 33. The new inner barrel mold 32 corresponding to the outer surface of the barrel portion 20 of the plastic bottle 10 can be assembled in the outer shell 33 according to the shape of the plastic bottle 10 that is removed.

  Similarly, since the bottom mold 35 has an outer bottom mold 36 and an inner bottom mold 37, the inner barrel mold 37 is removed from the outer bottom mold 36 to match the shape of the plastic bottle 10. Thus, a new inner bottom mold 37 corresponding to the outer surface of the bottom 25 of the plastic bottle 10 can be mounted on the outer bottom mold 36.

  Next, the operation of the present embodiment having such a configuration will be described.

  First, the inner body mold 32 of the body mold 31 is selected according to the shape of the body 20 of the plastic bottle 10 obtained by blow molding, and the inner body mold 32 is assembled into the outer shell 33. Similarly, the inner bottom mold 37 is selected according to the shape of the bottom 25 of the plastic bottle 10, and the inner bottom mold 37 is mounted on the outer bottom mold 36.

  Next, a preform is prepared, this preform is heated in advance, and then mounted in an open blow molding die 30, and the blow molding die 30 is sealed.

  Next, while the preform is stretched by the stretching rod from the mouth portion 11 of the preform, blow air is blown into the preform, and the preform is blow-molded to manufacture the plastic bottle 10.

  During this time, water, pressurized water or oil conditioned from the inlet 40a is caused to flow into the temperature control medium channel 40A of the enclosure 40, and the conditioned water, pressurized water or oil in the temperature control medium channel 40A is allowed to flow. It is discharged from the outlet 40b. As a result, the outer shell 33 and the inner body mold 32 can be heated from the enclosure 40, and the preform can be appropriately blow-molded in the blow-molding mold 30.

  Thus, the plastic bottle 10 can be obtained by blow-molding the preform in the blow-molding mold 30.

  Simultaneously with the blow molding, the neck 15 and the bottom 25 of the plastic bottle 10 are cooled in the blow mold 30. In this case, the neck mold 38 is cooled by the first cooling mechanism 38A, and the outer bottom mold 36 and the inner bottom mold 37 are cooled by the second cooling mechanism 36A.

  As a result, the neck portion 15 of the plastic bottle 10 that is unstretched and is thick and difficult to cool can be cooled by the neck mold 38, and the unstretched and thick bottom portion 25 is replaced by the outer bottom mold. 36 and the inner bottom mold 37 can cool.

  Thereafter, by opening the blow molding die 30, the plastic bottle 10 inside the blow molding die 30 can be taken out.

  Next, when the shape of the plastic bottle 10 is changed, the inner body mold 32 is removed from the outer shell 33 and a new inner body mold 32 corresponding to the shape of the body 20 of the plastic bottle 10 is selected. Assembled into the outer shell 33.

  Further, the inner bottom mold 37 can be removed from the outer bottom mold 36 and a new inner bottom mold 37 corresponding to the shape of the bottom 25 can be selected and mounted on the outer bottom mold 36.

  As described above, according to the present embodiment, when the shape of the plastic bottle 10 is changed, it is not necessary to replace the blow molding die 30 as a whole, and a new inner barrel metal according to the shape of the plastic bottle 10 is used. By replacing only the mold 32 and the new inner bottom mold 37, the blow molding mold 30 matched to the shape of the plastic bottle 10 can be configured. In this case, the inner body mold 32 to be replaced is extremely lightweight and has a small shape when viewed from the whole body mold 31 in which the inner body mold 32 and the outer shell 33 are combined. Similarly, the inner bottom mold 37 to be replaced is also extremely light in weight and small in shape when viewed from the bottom mold 35 as a whole combining the inner bottom mold 37 and the outer bottom mold 36.

  For this reason, the shape of the member to be replaced in accordance with the shape of the plastic bottle 10 can be made extremely small and lightweight. As a result, the manufacturing cost of the blow molding die 30 can be reduced as compared with the case where the entire blow molding die 30 is replaced each time according to the shape of the plastic bottle 10.

  Furthermore, since it is only necessary to replace the inner body mold 32 and the inner bottom mold 37 in accordance with the shape of the plastic bottle 10, the replacement parts can be easily stored and the replacement parts can be handled easily. Become.

  Further, it is not necessary to replace the neck mold 38 having the first cooling mechanism 38A and the outer bottom mold 36 having the second cooling mechanism 36A in accordance with the shape of the plastic bottle 10, so the blow molding mold 30 is replaced. At this time, since the first cooling mechanism 38A and the second cooling mechanism 36A do not need to be detached, it is easy to replace the blow molding die 30.

  Next, FIG. 8 shows an arrangement relationship between the first cooling mechanism 38 </ b> A and the inner body mold 32. Here, FIG. 8 is a perspective view showing the positional relationship between the first cooling mechanism 38 and the inner body mold 32.

  As described above, the first cooling mechanism includes the cooling water inflow port 38a, the outflow port 38b, and the cooling flow path 38c provided in the neck mold 38 (FIG. 7A). b) (see c)). As shown in FIG. 8, the cooling flow path 38c is connected to the inlet side cooling flow path 51 that communicates with the inlet 38a, and the outlet that is provided continuously with the inlet side cooling flow path 51 and communicates with the outlet 58b. Side cooling flow path 52. In this case, one of the cooling flow paths 38c, for example, the outlet side cooling flow path 52, overlaps with the inner body mold 32 in a plan view.

  Here, both the inlet side cooling channel 51 and the outlet side cooling channel 52 have a crescent shape in plan view.

Modified Example Next, a modified example of the present invention will be described with reference to FIGS. In the embodiment described above, it has been shown that the outlet side cooling flow path 52 of the cooling flow path 38c overlaps the inner body mold 32 in plan view, but the present invention is not limited thereto, and the cooling flow path 38c is not limited thereto. Both the inlet-side cooling channel 51 and the outlet-side cooling channel 52 may overlap the inner body mold 32 in plan view.

  In the modification shown in FIGS. 9 (a) and 9 (b), the same parts as those in the embodiment shown in FIGS.

  According to the present modification, both the inlet side cooling flow path 51 and the outlet side cooling flow path 52 of the cooling flow path 38c overlap with the inner body mold 32 in the plan view. Even if the neck mold 32 is somewhat heated by the part mold 32, the neck mold 38 can be reliably cooled by the cooling water flowing through the inlet side cooling channel 51 and the outlet side cooling channel 52.

  Next, another modification of the present invention will be described with reference to FIGS. In the embodiment and the modification described above, the cooling flow path 38c of the first cooling mechanism 38A has the inlet side cooling flow path 51 and the outlet side cooling flow path 52, and these inlet side cooling flow path 51 and the flow path. Although it has been shown that both of the outlet side cooling flow paths 52 have a crescent shape in plan view, the present invention is not limited to this, and the inlet side cooling flow path 51 may include a plurality of straight portions 51a (FIG. (B)). The outlet side cooling flow path 52 also includes a plurality of straight portions 52a.

  In the modification shown in FIGS. 10A and 10B, the same parts as those in the embodiment shown in FIGS.

  The cooling water supplied into the inlet side cooling flow path 51 reaches the straight portion 51a, and the neck mold 38 can be cooled by the cooling water entering the straight portion 51a.

  As shown in FIGS. 10A and 10B, among the inlet side cooling channel 51 and the outlet side cooling channel 52 constituting the cooling channel 38c of the first cooling mechanism 38A, the inlet side cooling channel. 51 overlaps with the inner body mold 32 in plan view.

  In the modification shown in FIG. 11, the same parts as those in the embodiment shown in FIGS.

  Next, still another modification of the present invention will be described with reference to FIG.

  FIG. 11 is a cross-sectional view showing a heat insulating space 55 formed between the neck mold 38 and the inner body mold 32. As shown in FIG. 11, the contact surface 38 s on the neck mold 38 side and the contact surface 32 s on the inner body mold 32 side abut between the neck mold 38 and the inner body mold 32. Thereby, the heat insulation space 55 is formed. Note that a heat insulating material (ceramic material) may be filled in part or all of the heat insulating space 55.

  Here, FIG. 11 schematically shows the cross section of the neck mold 38 and the outer shape of the inner body mold 32.

  As shown in FIG. 11, a heat insulating space 55 having a gap thickness of 0.5 mm to 5.0 mm is formed between the neck mold 38 and the inner body mold 32, and the heat insulating space 55 is a neck mold. It is formed over the entire circumference of the boundary between 38 and the inner body mold 32.

  As described above, the enclosure 40, the outer shell 33, and the inner body mold 32 are heated by the temperature-controlled water, pressurized water, or oil, but between the neck mold 38 and the inner body mold 32. By forming the heat insulation space 55, the heat propagation action to the neck mold 38 can be limited by the heat insulation space 55. Further, the neck mold 38 is prevented from being heated to a high temperature by the cooling action of the neck mold 38 by the first cooling mechanism 38A.

DESCRIPTION OF SYMBOLS 10 Plastic bottle 11 Mouth part 12 Shoulder part 15 Neck part 20 Body part 21 Side surface 22 Boundary surface 25 Bottom part 30 Blow molding die 31 Body part die 32 Inner trunk part mold 33 Outer shell 35 Bottom part mold 36 Outer bottom part mold 36A Second cooling mechanism 36a Inlet 36b Outlet 37 Inner bottom mold 38 Neck mold 38A First cooling mechanism 38a Inlet 38b Outlet 38c Cooling flow path 40 Enclosure 51 Inlet side cooling flow path 51a Linear portion 51b Branching portion 52 Outlet side cooling flow path 52a Linear portion 55 Thermal insulation space

Claims (11)

Blow for a plastic bottle for blow molding a plastic bottle having a trunk including a shoulder, a bottom below the trunk, a mouth above the trunk, and a neck located between the trunk and the mouth In the mold,
A body mold corresponding to the body including the shoulder of the plastic bottle;
A bottom mold corresponding to the bottom of the plastic bottle;
In addition to molding the neck corresponding to the neck of the plastic bottle, it has a neck mold provided separately from the body mold,
The body mold molds the body including the shoulder,
The neck mold is provided with a first cooling mechanism,
The trunk mold includes an inner trunk mold whose inner surface is defined corresponding to the outer surface of the trunk including the shoulder, and an outer shell positioned outside the inner trunk mold,
The inner body mold of the body mold can be exchanged from the outer shell corresponding to the shape of the plastic bottle,
The first cooling mechanism has a cooling flow path extending in the neck mold, and the cooling flow path of the first cooling mechanism overlaps at least a portion corresponding to the shoulder portion of the inner body mold in a plan view. Blow mold for plastic bottles.   The bottom mold includes an outer bottom mold and an inner bottom mold supported by the outer bottom mold and having an inner surface defined in correspondence with the outer surface of the bottom of the plastic bottle. The blow molding die for plastic bottles according to claim 1, wherein the die is provided with a second cooling mechanism.   The blow molding die for plastic bottles according to claim 1 or 2, wherein an enclosure is further provided outside the outer shell.   The blow molding die for plastic bottles according to claim 3, wherein the enclosure is provided with a heating mechanism.   The blow molding die for plastic bottles according to any one of claims 1 to 4, wherein the outer shell is engaged with the bottom die. The first cooling mechanism has an inlet and an outlet that communicate with the cooling channel,
The cooling channel of the first cooling mechanism includes an inlet-side cooling channel that communicates with the inlet, and an outlet-side cooling channel that is continuous with the inlet-side cooling channel and communicates with the outlet.
2. The blow molding for plastic bottle according to claim 1, wherein at least one of the inlet-side cooling channel and the outlet-side cooling channel overlaps a portion corresponding to a shoulder portion of the inner body mold in a plan view. Mold.   The blow molding mold for plastic bottles according to claim 6, wherein both the inlet side cooling flow path and the outlet side cooling flow path overlap with the inner body mold in a plan view.   The blow molding die for plastic bottles according to claim 6 or 7, wherein the inlet side cooling channel and the outlet side cooling channel have a crescent shape in plan view.   8. The blow molding die for plastic bottles according to claim 6, wherein each of the inlet-side cooling channel and the outlet-side cooling channel includes a plurality of linear portions.   10. The blow mold for plastic bottles according to claim 9, wherein a branch portion is connected to a straight portion of the inlet side cooling channel or the outlet side cooling channel.   The blow molding mold for plastic bottles according to any one of claims 1 to 10, wherein a heat insulating space is formed between the neck mold and the inner body mold.