JP2012224039A - Blow molding die opening and closing mechanism, and biaxially stretching blow molding machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a blow molding die opening and closing mechanism of a small and compact constitution, which can smoothly perform the die opening and closing operation.SOLUTION: In the die opening and closing mechanism 23, the rocking movement in the vertical direction of left and right, first and second rocking ends 41a and 41b of a rocking plate 41 arranged under a left and right pair of first and second blow forming dies 21 and 22 are converted into the going up-and-down motions of left and right, the first and second going up-and-down sliders 51 and 52 through the first and second connecting shafts 45 and 46 that vertically arrange. These going up-and-down motions are converted into the opening or closing movements of the first and second left and right blow molding dies 21 and 22 through left and right parallel linkage mechanisms 61 and 62. Since a complex link mechanism as the die opening and closing operation is done by bending exercises of the toggle link mechanism need not be used, the die opening and closing operation can be performed by smoothly and speedily. Since reduction of the number of components of die opening and closing mechanism can be performed, making the mechanism small and compact can be achieved.

Description

  The present invention includes a blow mold opening / closing mechanism that opens and closes a pair of left and right blow molds used for blow molding or stretch blow molding a preform that is an injection molded product of resin, and the blow mold opening / closing mechanism. The present invention relates to a biaxial stretch blow molding machine.

  A biaxial stretch blow molding machine for producing resin molded products such as PET bottles by biaxial stretch blow molding heated a primary molded product called a preform to a temperature suitable for molding while being conveyed through a heating unit. Later, the preform is subjected to biaxial stretch blow molding in a stretch blow mold.

  An open / close mechanism (clamping mechanism) that opens and closes a pair of blow molds used for biaxial stretch blow molding of a preform is supported by left and right blow molding supported so as to be slidable horizontally. Each of the molds is known to be opened and closed by an air cylinder via a toggle link mechanism. Patent Document 1 by the present applicant proposes a mold clamping mechanism having such a structure.

  In the mold clamping mechanism disclosed in Patent Document 1, a pair of toggle links for opening and closing a pair of blow molding dies using a vertical swing motion at a position symmetrical to the left and right from the swing center of the swing plate. The mechanism is moved in the opposite direction with complete synchronization. Therefore, an uneven load is not generated in each part of the mold clamping mechanism when the mold is opened and closed, and adverse effects such as generation of wear of each part and application of impact force to each part can be avoided. Therefore, a smooth and quick mold opening / closing operation can be realized, and as a result, the operation speed of the biaxial stretch blow molding machine can be increased.

JP 2008-260302 A

  In recent years, there is a high demand for downsizing and improving the processing speed of a biaxial stretch blow molding machine. In order to meet the demand for downsizing, it is effective to reduce the size and size of the biaxial stretch blow molding part that requires a large installation space, and in particular, to reduce the size and size of the mold opening / closing mechanism. In order to increase the processing speed, it is effective to further smooth the opening / closing operation of the blow molding die by the die opening / closing mechanism.

  In view of these points, the present invention has a small and compact blow molding mold opening / closing mechanism capable of smoothly performing mold opening / closing operation, and biaxial stretching provided with the blow molding mold opening / closing mechanism. It is to propose a blow molding machine.

In order to solve the above problems, the blow molding die opening and closing mechanism of the present invention is
A swing member disposed below the pair of left and right first and second blow molds;
A drive source for swinging the swing member up and down around a predetermined swing center;
A first swinging portion and a second swinging portion of the swinging member that are symmetrically positioned in the opening / closing direction of the first and second blow molds with respect to the swing center;
A pair of left and right first and second elevating sliders sandwiched between the first and second blow molds and disposed at symmetrical positions in the opening and closing direction;
A first connecting member that converts an upward and downward swing motion of the first swing portion into an upward motion and a downward motion of the first lifting slider;
A second connecting member that converts a downward and upward swing motion of the second swing portion into a downward motion and a lift motion of the second lift slider;
A third movement for converting the upward and downward movements of the first lifting slider into a mold opening movement from the closed position to the open position and a mold clamping movement from the open position to the closed position, respectively. A connecting member;
A fourth movement for converting the lowering and rising movements of the second lifting slider into a mold opening movement from the closed position to the open position and a mold clamping movement from the open position to the closed position, respectively. And a connecting member.

  In the blow mold opening / closing mechanism of the present invention, when the left and right first and second blow molds are in the mold open state, the swing member swings upward at the first swing portion, and the second swing portion. Is in a state of swinging downward. In this state, when the swinging member is swung by the drive source to swing the first swinging portion downward and the second swinging portion swings upward, these swinging motions are caused by the first and first swinging motions. It is converted into a rising motion of the first lifting slider and a lowering motion of the second lifting slider via the two connecting members. The ascending motion of the first lifting / lowering slider is changed to the clamping motion of the first blow molding die via the third connecting member, and the descending motion of the second lifting / lowering slider is changed to the die of the second blow molding die via the fourth connecting member. It is converted into a clamping motion, and the first and second blow molds can be clamped. In the case of mold opening, the swing member may be swung in the reverse direction by the drive source.

  The first and second elevating members from the upper side through the third and fourth connecting members are connected to the first and second oscillating portions that are symmetric with respect to the oscillating center of the oscillating member. Their own weight acts, and these are balanced around the center of oscillation. Therefore, the swinging member can be swung by a small driving force to perform mold clamping and mold opening operation. Further, since the first and second elevating sliders are moved up and down by the swinging member, each member can move smoothly compared to the case where the toggle link mechanism is bent and extended by the swinging member. Therefore, mold clamping and mold opening operations can be performed more smoothly than when using a toggle link mechanism.

  In the present invention, instead of oscillating the oscillating member by the drive source, one of the first and second elevating sliders can be directly driven by a linear actuator comprising, for example, a ball screw and a servo motor. In this case, the oscillating member is oscillated by the elevating motion of one of the elevating sliders, and the other elevating slider is moved up and down synchronously in the reverse direction due to this oscillation.

  Here, in the present invention, the first connecting member is arranged in the vertical direction, and the lower end portion thereof is connected to the first swinging portion via the pin node, and the second connecting member is similarly set in the vertical direction. It arrange | positions and the lower end part is connected via the pin node with respect to the 2nd rocking | swiveling site | part. The first and second connecting members move in the axial direction while maintaining the vertical posture. Therefore, only the axial compressive force and tensile force act on these members, and the vertical force also acts on the swing member and the first and second elevating sliders. Therefore, a force is applied to each portion in an oblique direction, and an undesired uneven load such as a bending load and a shear load is generated, so that the smooth movement of each portion is not hindered.

  In the present invention, the third connecting member is bridged between the first elevating slider and the first mold supporting member supporting the first blow mold, and both end portions thereof are the first elevating slider. And it is connected with the 1st type support member via a pin node, respectively. Similarly, the fourth connecting member is bridged between the second elevating slider and the second mold supporting member supporting the second blow molding die, and both end portions thereof are the second elevating slider and the second mold. Each pin is connected to the support member via a pin node. Further, the third connecting member assumes a horizontal posture when the first blow molding die moves to the closed position, and when the first blow molding die moves to the open position, the first elevating slider side assumes a high inclined posture, and the fourth connecting die The member is set so that when the second blow mold is moved to the closed position, the second lifting / lowering slider side is in a low inclined posture, and when the second blow mold is moved to the open position, it is in a horizontal posture.

  In this way, the number of parts of the link mechanism for opening and closing the mold can be reduced as compared with the case of using a link mechanism composed of a plurality of connecting members such as a toggle link mechanism. -It is advantageous for downsizing. Further, the operation of converting the swinging motion of the swinging member into the mold opening / closing motion can be performed more smoothly than in the case of performing a bending / extending motion like a toggle link mechanism.

  Here, in order to more smoothly convert the lifting movement of the first and second lifting sliders into the mold opening and closing movement without rattling, the present invention uses the third and fourth connecting members, respectively, A parallel link mechanism is configured. That is, as the third connecting member, two upper and lower connecting members constituting a four-joint parallel link mechanism are provided between the first blow molding die and the first elevating slider. Two upper and lower connecting members constituting a four-node parallel link mechanism are provided between the two-blow mold and the second elevating slider.

  Next, according to the present invention, the preform is biaxially stretched and blow-molded by transporting a preform carrier carrying the preform along a transport path passing through the heating section and the biaxial stretch blow-molded section. In a biaxial stretch blow molding machine for forming a shaped product, the biaxial stretch blow molding section has a pair of blow molds and a mold opening / closing mechanism for opening and closing these blow molds. As a mechanism, the blow molding die opening / closing mechanism having the above-described configuration is used.

(A) And (B) is the schematic plan view and schematic side view of the biaxial stretch blow molding machine to which this invention is applied. (A)-(C) are explanatory drawing which shows the shape of a preform, explanatory drawing which shows the structure of a preform carrier, and explanatory drawing which shows the shape of a molded article. (A) is the schematic side view which looked at the type | mold opening-and-closing mechanism from the direction orthogonal to a preform conveyance direction, (B) is the schematic plan view.

  A biaxial stretch blow molding machine for producing PET bottles equipped with a blow mold opening / closing mechanism to which the present invention is applied will be described below with reference to the drawings.

(Overall configuration and operation)
1A and 1B are a plan view and a side view showing the overall configuration of the biaxial stretch blow molding machine of this example. Referring to these drawings, the biaxial stretch blow molding machine 1 has a horizontally long gantry frame 2, and a preform supply unit 3 is formed on the upper surface of the gantry frame 2 along the preform conveyance path. The preform heating units 4 (1) to 4 (5), the biaxial stretch blow molding unit 5 of the preform P, and the molded product takeout unit 6 are arranged in this order.

  The preform supply unit 3 of the present example receives the preform carrier 7 conveyed in an inverted state where the molded product F is unloaded and is empty, and after the preform P is attached thereto, the preform carrier 7 is inverted. It is set in an upright state, and thereafter, it is handed over to a pair of guide rails 8 (1) that define a transport path at a position one level higher.

  The preform carrier 7 delivered to the pair of guide rails 8 (1) is sequentially pushed forward along the guide rails 8 (1) and passes through the heating units 4 (1) to 4 (5). Delivered to the transport path 8 (2). The transport path 8 (2) includes a transport belt 11 spanned between the driving pulley 9 and the driven pulley 10, and a plurality of transport belts 11 attached to the transport belt 11 at a predetermined interval and circulated together with the transport belt 11. The preform carrier transfer tool 12 is provided. One linear conveyance path portion defined by the conveyance belt 11 passes through a heating portion by the heating units 4 (1) and 4 (2), and the preform conveyed by the transfer tool 12 is passed through this portion. A drive mechanism 13 for rotating the preform P carried on the carrier 7 is provided. Similarly, the other straight conveyance path part prescribed | regulated by the conveyance belt 11 has passed the heating part by heating part 4 (3) -4 (5), and is conveyed by the transfer tool 12 to this part. A drive mechanism 14 for rotating the preform P carried on the preform carrier 7 is provided.

  The preform carrier 7 delivered from the pair of guide rails 8 (1) to each transfer tool 12 in the transport path 8 (2) is sequentially heated by the heating units 4 (1) to 4 (5) by each transfer tool 12. To pass through. Further, while passing through these heated portions, the preform P carried on the preform carrier 7 is rotated by the drive mechanisms 13 and 14, so that the outer peripheral surface of each preform P is uniformly heated.

  The preform carrier 7 carrying the preform P heated to a temperature suitable for molding via the heating units 4 (1) to 4 (5) is an upper conveyance path defined by a pair of guide rails 8 (3). To be handed over. This guide rail 8 (3) extends through the biaxial stretch blow molding portion 5. The biaxially stretched blow molding unit 5 includes a pair of left and right blow molding dies 21 and 22 centering on a preform conveyance path defined by the guide rail 8 (3). It is opened and closed by the mechanism 23.

  A feed pitch enlarging mechanism 24 is disposed on the front side of the biaxial stretch blow molding unit 5 in the preform conveyance direction. The preform carrier 7 that has been continuously conveyed toward the biaxially stretched blow-molded portion 5 along the guide rail 8 (3) has a feed pitch suitable for the molded product F by the feed pitch expanding mechanism 24. Widened to the feed pitch.

  Thereafter, the preform P carried on the preform carrier 7 is fed to the biaxial stretch blow molding position of the biaxial stretch blow molding section 5 by the transport mechanism 25 while maintaining a wide feed pitch. The preform P is biaxially stretch blow-molded in the biaxial stretch blow molding portion 5 to form a PET bottle (molded product) F having a predetermined shape. The preform carrier 7 carrying the PET bottle F, which is a molded product, is fed from the biaxial stretch blow molding section 5 along the guide rail 8 (3) by the transport mechanism 25 while maintaining a wide feed pitch. . Further, the transfer mechanism 25 delivers the molded product take-out section 6 with a wide feed pitch.

  The molded product take-out unit 6 receives the preform carrier 7 carrying the PET bottle F from the guide rail 8 (3) and reverses it. Further, the PET bottle F, which is a molded product, is extracted from the preform carrier 7 that is inverted and inverted, and thereafter, a pair of guide rails 8 that are horizontally disposed at a position one step lower than the guide rails 8 (3). The empty preform carrier 7 from which the molded product has been extracted is delivered to the lower conveyance path defined by (4) while being inverted.

  The molded product F pulled out from the preform carrier 7 is delivered to a molded product collection path 8 (6) extending in the direction opposite to the guide rail 8 (4), and collected by a collection unit (not shown).

  The guide rail 8 (4) extends to the preform supply unit 3 through a dead space below the pair of blow molding dies 21 and 22 of the biaxially stretched blow molding unit 5 and inverts an empty preform carrier 7. Delivered to the preform supply unit 3 in the state. As described above, the preform supply unit 3 supports the preform on the preform carrier 7 received in the inverted state, and then reverses the preform carrier 7 to bring it upright. After that, it is handed over to a pair of guide rails 8 (1) defining a transport path that is one step higher than the guide rails 8 (4).

  Thereafter, the above steps are repeated, the preform is conveyed by each preform carrier 7, and the biaxial stretch blow molding is repeated.

(Preform, preform carrier, molded product)
FIG. 2 is a view showing the preform P, the preform carrier 7 and the molded product F. As shown in FIG. 2 (A), the preform P is a PET primary molded product having a test tube shape with one end serving as a mouth portion P1, and the outer peripheral surface between the mouth portion P1 and the cylindrical body portion P2 is formed on the outer peripheral surface. An annular protrusion P3 is formed.

  As shown in FIG. 2B, the preform carrier 7 has a cylindrical main body 31, and a large-diameter flange 32 is formed at the upper end portion of the cylindrical main body 31. From the upper end of the flange 32, a small-diameter cylindrical insertion core portion 33 concentrically protrudes upward, and the insertion core portion 33 can be inserted into the mouth of the preform P. On the outer periphery of the cylindrical main body 31, an annular flange 34, an annular external gear 35 and an annular plate 36 are mounted in this order on the lower side of the flange 32, and are fixed so as not to come off by a retaining ring 37.

  Here, the annular flange 34 has the largest diameter, and this portion functions as a slide portion that slides horizontally along a guide rail described later. A cylindrical main body 31 inside the annular flange 34 is rotatable with respect to the annular flange 34, and an annular external gear 35 is fixed to the cylindrical main body 31 so as to rotate integrally. The drive mechanisms 13 and 14 include a timing belt that meshes with the external gear 35. When the preform carrier 7 moves while the external gear 35 meshes with the timing belt, the external gear 35 rotates and the cylindrical main body 31 also rotates. Rotates together. Therefore, the preform P conveyed while being inserted into the insertion core portion 33 formed at the tip also rotates.

  FIG. 2C shows a molded product F obtained by performing biaxial stretch blow molding in the biaxial stretch blow molding section 5. The molded product F of this example is a PET bottle, the mouth part F1 and the annular protrusion F3 are the parts where the mouth part P1 and the annular protrusion P3 of the preform P remain as they are, and the cylindrical body part F2 is the preform P. This is a biaxially stretched blow molded portion of the cylindrical body P2.

(Die opening / closing mechanism of biaxial stretch blow molding part)
FIG. 3A is a schematic side view of the mold opening / closing mechanism 23 viewed from a direction orthogonal to the preform conveying direction, and FIG. 3B is a schematic plan view thereof. Referring to these drawings, the mold opening / closing mechanism 23 includes a swing plate 41 (swing member). The swing plate 41 is a rectangular plate that is positioned right below the pair of left and right first and second blow molding dies 21 and 22 and is long in a direction perpendicular to the preform conveying direction. The oscillating plate 41 is supported by the vertical column 43 of the gantry frame 2 in a state in which the oscillating plate 41 can oscillate in the vertical direction about the oscillating center shaft 42 located at the center in the direction orthogonal to the preform conveying direction.

  The swing plate 41 has a left first swing end portion 41a (first swing portion) and a right second swing end portion 41b (first swing portion) at positions symmetrical to the swing center axis 42. 2 rocking parts) are provided. In this example, the second swing end 41b on the right side is connected to the operating rod 44a of the swinging air cylinder 44 (drive source). The swinging air cylinder 44 is vertically attached to the gantry frame 2 in an upward posture, and the upper end of the operating rod 44a that expands and contracts in the vertical direction is below the second swinging end 41b on the right side of the swinging plate 41. Pinned to the site.

  The first oscillating end 41a and the second oscillating end 41b of the oscillating plate 41 are respectively provided with a lower end 45a of the left first connecting shaft 45 (first connecting member) and a right second connecting shaft 46. The lower end portion 46a of the (second connecting member) is connected through pin nodes 47 and 48. The first and second connecting shafts 45 and 46 extend vertically, and their upper end portions 45b and 46b are respectively connected to the left first elevating slider 51 and the right second slider via pin nodes 49 and 50, respectively. The lift slider 52 is connected.

  The first and second elevating sliders 51 and 52 have the same dimensions and the same weight, sandwich the left and right first and second blow molding dies 21 and 22, and open / close directions 53 of these dies (in the preform conveying direction). It is arranged in a symmetrical state at a symmetrical position in the (perpendicular direction). The first and second elevating sliders 51 and 52 can be moved up and down along elevating slide rails 56 and 57 fixed to the left and right vertical guide frames 54 and 55 of the gantry frame 2, respectively. Therefore, when the swing plate 41 swings and the left and right first and second connecting shafts 45 and 46 connected to the left and right first and second swing end portions 41a and 41b move up and down, One of the connected left and right first and second elevating sliders 51 and 52 is raised and the other is lowered.

  Further, the first and second elevating sliders 51 and 52 are respectively connected to the left and right first and second blow molds 21 through four-node parallel link mechanisms 61 and 62 (third and fourth connecting members), respectively. 22 are connected to the left and right first and second mold support members 63 and 64 to which the left and right members 22 are attached. The left parallel link mechanism 61 includes an upper link 65 and a lower link 66 arranged in parallel at the upper and lower positions. The upper link 65 and the lower link 66 are each composed of a pair of front and rear links arranged at a constant interval in the preform conveying direction. Also, one end of the upper link 65 and the lower link 66 is connected to the first elevating slider 51 on the left side via pin nodes 67 and 68, and the other ends of these links are also connected to pin nodes 69 and 70. And is connected to the left mold support member 63. Since the right parallel link mechanism 62 has a symmetrical structure with the left parallel link mechanism 61, the same reference numerals are given to the portions corresponding to the left parallel link mechanism 61 in the figure.

  Here, the left and right first and second mold support members 63 and 64 are slidable in the mold opening and closing direction. That is, a slide rail 72 is fixed horizontally to the horizontal frame 71 of the gantry frame 2 along the mold opening / closing direction, and left and right sliders 73 and 74 slidable along the slide rail 72 have first left and right sliders. The second type support members 63 and 64 are attached. As can be seen from the figure, in this example, when the left and right first and second blow molds 21 and 22 are in the closed position, the upper link 65 and the lower link 66 in the left and right parallel link mechanisms 61 and 62 are It is set to have a horizontal posture extending horizontally in the mold opening and closing direction. In this mold clamping state, the swing plate 41 is set so that the first swing end portion 41a on the left side has a lower inclined posture. That is, the left first connecting shaft 45 is longer than the right second connecting shaft 46.

  From this state, when the swing plate 41 is swung clockwise in the drawing to a substantially horizontal posture, the left first lift slider 51 is raised and the right second lift slider 52 is lowered. These up-and-down movements are converted into mold opening movements of the left and right first and second blow molds 21 and 22 via the left and right parallel link mechanisms 61 and 62. That is, as shown by the imaginary line in the figure, the upper and lower links 65 and 66 of the left parallel link mechanism 61 have a high inclined posture on the first elevating slider 51 side, and the left first blow molding die 21 is opened. The upper and lower links 65 and 66 of the right parallel link mechanism 62 are in a low inclined posture, and the right second blow molding die 22 is horizontally placed in the mold opening direction. Pull in. In this way, the left and right lifting sliders 51 and 52 are raised and lowered in a state in which they are synchronized in opposite directions, and the first and second blow molding dies 21 and 22 are also mutually moldd in a synchronized state. Opening and clamping operations are performed.

  In the mold opening / closing mechanism 23 of this example, the first rocking end portion 41a and the second rocking end portion 41b, which are located symmetrically with respect to the rocking central axis 42 of the rocking plate 41, are rocked in the opposite directions in the vertical direction. The lift slider 51 and the parallel link mechanism 61 for opening and closing the pair of left and right blow molding dies 21 and 22 by using the dynamic motion, and the lift slider 52 and the parallel link mechanism 62 are completely synchronized in the reverse direction. To move to. Therefore, an uneven load is not generated in each part constituting the mold opening / closing mechanism 23 when the mold is opened / closed, and adverse effects such as wear of each part and application of impact force to each part can be avoided. In addition, since the lift sliders 51 and 52 and the parallel link mechanisms 61 and 62 are used, a smooth and quick mold opening / closing operation can be realized as compared with the case where the bending and stretching movement is performed as in the toggle link mechanism. Furthermore, the components of the mold opening / closing mechanism 23 can be reduced, which is advantageous for reducing the size and size of the mechanism.

(Other embodiments)
In the above example, the swing plate 41 is swung using the drive source. Instead, the elevating slider 51 or 52 may be driven directly. For example, by using a ball screw and a servo motor as a drive source, one lifting slider 51 is directly lifted and this lifting motion is transmitted to the other lifting slider 52 via the swinging motion of the swinging plate 41, and You may make it raise / lower the raising / lowering slider 52 synchronously in the reverse direction. Also in this case, since both the lift sliders 51 and 52 are moved up and down in the opposite direction, the pair of left and right blow molding dies 21 and 22 can be opened and closed in synchronization.

DESCRIPTION OF SYMBOLS 1 Biaxial stretch blow molding machine 2 Base frame 3 Preform supply part 4 (1) -4 (5) Heating part 5 Biaxial stretch blow molding part 7 Preform carrier 8 (1), 8 (3) Upper guide rail ( Upper transport path)
8 (4) Lower guide rail (lower transfer path)
21 First blow molding die 22 Second blow molding die 23 Mold opening / closing mechanism 41 Oscillating plate 41a First oscillation end portion 41b Second oscillation end portion 42 Oscillation center shaft 44 Air cylinder 45 First connection shaft 46 Second Connection shafts 47, 48 Pin node 51 First lifting slider 52 Second lifting slider 53 Mold opening / closing direction 61 First parallel link mechanism 62 Second parallel link mechanism 63 First mold support member 64 Second mold support member 65 Upper link 66 Lower Link 67-70 Pin node P Preform F Molded product

Claims (6)

A swing member (41) disposed below the pair of left and right first and second blow molds (21, 22);
A drive source (44) for swinging the swing member (41) up and down around a predetermined swing center axis (42);
The first swinging of the swinging member (41) at a symmetrical position in the opening / closing direction (53) of the first and second blow molds (21, 22) with respect to the swinging central axis (42). A portion (41a) and a second swinging portion (41b);
A pair of left and right first and second elevating sliders (51, 52) disposed at left and right symmetrical positions in the opening and closing direction (53) with the first and second blow molds (21, 22) sandwiched therebetween,
A first connecting member (45) for converting an upward and downward swinging motion of the first swinging portion (41a) into an upward motion and a downward motion of the first lifting slider (51), respectively;
A second connecting member (46) for converting a downward and upward swinging motion of the second swinging portion (41b) into a lowering motion and a lifting motion of the second lifting slider (52), respectively;
The upward movement and the downward movement of the first elevating slider (51) are respectively the mold opening movement from the closed position to the open position and the mold clamping from the open position to the closed position of the first blow molding die (21). A third connecting member (65, 66) for converting into motion;
The downward movement and the upward movement of the second lift slider (52) are respectively the mold opening movement from the closed position to the open position of the second blow mold (22) and the mold clamping from the open position to the closed position. A blow mold opening / closing mechanism (23), comprising: a fourth connecting member (65, 66) for converting into motion. A swing member (41) disposed below the pair of left and right first and second blow molds (21, 22) and swingable about a predetermined swing center axis (42);
The first swinging of the swinging member (41) at a symmetrical position in the opening / closing direction (53) of the first and second blow molds (21, 22) with respect to the swinging central axis (42). A portion (41a) and a second swinging portion (41b);
A pair of left and right first and second elevating sliders (51, 52) disposed at left and right symmetrical positions in the opening and closing direction (53) with the first and second blow molds (21, 22) sandwiched therebetween,
A drive source for raising and lowering the first elevating slider (51);
A first connecting member (45) for converting the upward and downward movements of the first elevating slider (51) into upward and downward swinging motions of the first swinging portion (41a), respectively;
A second connecting member (46) for converting a downward and upward swinging motion of the second swinging portion (41b) into a lowering motion and a lifting motion of the second lifting slider (52), respectively;
The upward movement and the downward movement of the first elevating slider (51) are respectively the mold opening movement from the closed position to the open position and the mold clamping from the open position to the closed position of the first blow molding die (21). A third connecting member (65, 66) for converting into motion;
The downward movement and the upward movement of the second lift slider (52) are respectively the mold opening movement from the closed position to the open position of the second blow mold (22) and the mold clamping from the open position to the closed position. A blow mold opening / closing mechanism (23), comprising: a fourth connecting member (65, 66) for converting into motion. In claim 1 or 2,
The first connecting member (45) extends in the vertical direction, and a lower end portion of the first connecting member (45) is connected to the first swinging part (41a) via a pin node (47).
The second connecting member (46) extends in the vertical direction, and a lower end thereof is connected to the second swinging part (41b) via a pin node (48). Mold opening / closing mechanism (23). In claim 3,
The third connecting member (65, 66) spans between the first elevating slider (51) and a first mold support member (63) supporting the first blow molding die (21). Both ends thereof are connected to the first elevating slider (51) and the first mold support member (63) via pin nodes (67, 68; 69, 70), respectively.
The fourth connecting members (65, 66) are bridged between the second elevating slider (52) and the second mold support member (64) supporting the second blow molding die (22). Both ends thereof are connected to the second elevating slider (52) and the second mold support member (64) through pin nodes (67, 68; 69, 70), respectively.
The third connecting member (65, 66) is in a horizontal posture when the first blow mold (21) is moved to the closed position, and the first connection member (65, 66) is moved to the first position when the first blow mold (21) is moved to the open position. The lift slider (51) side is in a high inclination posture,
When the second blow molding die (22) moves to the closed position, the fourth connecting member (65, 66) has a low inclined posture on the second lifting / lowering slider (52) side, and the second blow molding die ( 22) A blow mold opening / closing mechanism (23), wherein the blow molding die opening / closing mechanism (23) is in a horizontal posture when moved to an open position. In claim 4,
As the third connecting member, two upper and lower connecting members (65) constituting a four-node parallel link mechanism (61) between the first blow mold (21) and the first elevating slider (51). 66)
As the fourth connecting member, two upper and lower connecting members (65) constituting a four-node parallel link mechanism (62) between the second blow mold (22) and the second elevating slider (52). 66), a blow molding die opening and closing mechanism (23). The preform (P) is biaxially stretched by transporting the preform carrier (7) carrying the preform (P) along the transport path passing through the heating section and the biaxial stretch blow molding section (5). In the biaxial stretch blow molding machine (1), which is blow molded into a molded product (F) having a predetermined shape,
The biaxially stretched blow-molded part (5) has a pair of blow molds (21, 22) and a mold opening / closing mechanism for opening and closing these blow molds (21, 22).
A biaxial stretch blow molding machine (1), wherein the mold opening / closing mechanism is the blow molding mold opening / closing mechanism (23) according to any one of claims 1 to 5.

Images