JP2010110995A - Blow molding machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a blow molding machine which makes the clamping force of a mold be adjusted easily and surely and can correspond to the change of the kind or shape of the mold. <P>SOLUTION: As regards a mold clamping drive mechanism 30 installed in the blow molding machine, a bracket 52 in which the end of a link arm 32 cooperating with a rear support plate 8 out of a pair of first and second link arms 31 and 32 is supported rotatably through an eccentric link pin 51, a shaft 53 which keeps one end fixed to the bracket 52 and is supported movably in the axial direction by the rear support plate 8, and a plurality of belleville springs 56 which are installed to bias the shaft 53 to one end side and assist the mold clamping force of a mold 12 by their bias power are provided. In accordance with the eccentric position of the eccentric link pin 51, a load applied to each belleville spring 56 is changed through the shaft 53 to change the mold clamping force of the mold 12. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a so-called hollow molding apparatus, and more particularly, to an improvement of a mold clamping drive mechanism of a hollow molding apparatus that can effectively apply a necessary clamping force to a molding die according to the shape of the molding die. .

  In brief, a hollow molding apparatus for molding a hollow molded product introduces a parison discharged from the head of an extruder into a molding die, blows air into the parison, and engraves it on the inner surface of the molding die. A parison is swelled in the provided cavity to mold a hollow molded product, and a mold clamping device for closing or opening the mold is provided.

  For example, as shown in FIG. 8, a mold clamping device as shown in Patent Document 1 below inserts a plurality of tie bars 133, 134, and 135 so as to be movable in an appropriate movable base 132 so that these tie bars 133 are movable. , 134, 135, the front support plate 136 and the rear support plate 137 are fixed, the front platen 140 is attached to the front support plate 136, and the rear platen 145 is slidably inserted into the tie bars 133, 134. Each of the split molds 141 and 144 forming a molding die is attached to 140 and 145, and a mold clamping drive mechanism 156 is interposed between the rear platen 145 and the rear support plate 137. The mold clamping drive mechanism 156 moves the front platen 140 and the rear platen 145 relatively close to or away from each other via the tie bars 133 and 134 inserted through the slide collars 142, 143, 146, and 147, thereby opposing the split mold 141. , 144 are opened and closed and mold clamping is performed.

  In the mold clamping drive mechanism 156, a rotary disk 155 is provided on a shaft 158 rotatably supported by a slide block 157, and the shaft 158 is coupled to a drive shaft of an electric motor (not shown) to form a pair of link arms 154. One end portion of 161 is rotatably connected to a radially opposing position of the rotary disk 155. The slide block 157 is fixed upright on slide collars 159 and 160 that are inserted so that the tie bars 133 and 134 can move in the horizontal direction.

The other end of the link arm 154 is rotatably supported by a bracket 153 attached to the back surface of the rear platen 145. The other end of the link arm 161 is rotatably supported on the shaft 165 by a shaft 164a. The shaft 165 is inserted into a box-shaped disc spring arrangement portion 166 provided at the upper end portion of the rear support plate 137 so as to be movable in the axial direction. In the disc spring arrangement portion 166, a plurality of disc springs 167 fitted into the shaft 165 are accommodated and arranged with their concave surfaces facing each other so that they can be loosened and pressed against each other. A bush 168 disposed in front of the disc spring 167 presses and bends the plurality of disc springs 167 to apply a preload to the disc spring 167. Then, with the restoring force of the deflected disc spring 167, the rear platen 145 is pressed toward the front platen 140 via a pair of link arms 154 and 161 extending in a straight line in the horizontal direction, and the mold is clamped. It is like that.
JP-A-7-32366

  However, in the mold clamping device of such a hollow molding apparatus, the mold clamping force is adjusted by the hollow molded product molded by the user and the molding used at the time of designing, manufacturing, assembling, or trial operation of the hollow molding machine. Listening to the mold type and shape, molding conditions, etc., compressing the disc spring by selecting the structure of the clamping mechanism, selecting the disc spring type and shape, and adjusting the elastic force of the bracket against the disc spring The degree of restoring force based on deformation, mold clamping force and holding pressure are adjusted. Therefore, it is extremely difficult for the user to adjust the restoring force of the adjusted disc spring.

  The present invention has been devised in view of such technical problems, and the mold clamping force of the molding die can be adjusted easily and reliably, and the type and shape of the molding die can be changed. An object of the present invention is to provide a hollow molding apparatus that can be used.

  According to the first aspect of the present invention, there are provided a front support plate and a rear support plate fixed to both ends of a tie bar extending in the horizontal direction, a front platen positioned between the plates and attached to the front support plate, and the A rear platen slidably provided on a tie bar, a mold in which a pair of split molds are attached to both platens, and a pair of links disposed between the rear platen and the rear support plate A mold clamping drive mechanism that opens and closes and molds the mold by extending and bending the arm, and the mold clamping drive mechanism is provided behind the link arm on the rear support plate side of the pair of link arms. A bracket that rotatably supports the end portion by an eccentric link pin, and a tip end portion fixed to the bracket, are moved in the axial direction to the rear support plate. And rotatably supported by a shaft and fitted oppression to the shaft, it is characterized in that a plurality of disc springs to vary the clamping force by changing a load capacity by an eccentric position of the eccentric link pin.

  According to this invention, by rotating the eccentric link pin and changing the eccentric position of the eccentric link pin, the bracket and the shaft move toward the one axial end side of the shaft by the amount of eccentricity, and the shaft is biased. The load on the urging member to be changed changes. Thereby, the urging force of the urging member can be changed, and as a result, the mold clamping force of the mold can be changed.

  The invention according to claim 2 is the invention according to claim 1, wherein the bracket has a bifurcated bearing portion for rotatably supporting the eccentric link pin, and the eccentric link pin is the bifurcated bearing portion. And a supported shaft portion, and an eccentric shaft portion having an eccentric center with respect to the shaft centers.

  According to the present invention, the eccentric link pin can be switched easily and reliably by reliably supporting the supported portions at both ends of the eccentric shaft portion on the bifurcated bearing portion of the bracket.

  According to a third aspect of the invention, in the invention of the first or second aspect, the mold clamping drive mechanism includes a rotor having a long end pair and a short end pair that are rotated by an electric motor, Each pair of longitudinal end portions of the rotor is opposite to each other with respect to the rotation center of the rotor, and ends of the pair of link arms are rotatably connected.

  According to the present invention, since the electric motor is used as a means for generating the mold clamping force for the pair of link arms, the mold clamping force can be finely adjusted, and various mold clamping forces can be reliably and easily obtained. Can be generated.

  According to the present invention, the mold clamping force of the mold can be adjusted by an extremely easy operation such as rotating the eccentric link pin, and the mold clamping force of the mold is not accompanied by complicated work such as disassembly of the apparatus. Can be adjusted easily and reliably.

  Hereinafter, embodiments of a hollow molding apparatus according to the present invention will be described in detail with reference to FIGS.

  As shown in FIGS. 1 and 2, a pair of left and right guide rails 2, 2 are laid apart from each other on the upper surface of the base 1, and the movable base 3 extends in the depth direction in FIG. 1 on these guide rails 2, 2. It is slidably mounted. Then, three tie bars 4, 5 and 6 are inserted and supported in the horizontal direction in an inverted triangular arrangement on the movable base 3, and the front support plate 7 and the rear support plate 8 are fixed to both ends of these tie bars by screws. Has been. Since the tie bar 5 is hidden behind the tie bar 4 in FIG. 1, the reference numeral 5 is shown in parentheses in the figure. Similarly, members that support the tie bar 5 and the like and are hidden in the drawing are shown with parentheses attached to the reference numerals.

  A bracket 10 attached to the front platen 9 is rotatably supported by a shaft 11 at the upper end portion of the front support plate 7. The front platen 9 is attached with one split mold 12 a of a pair of split molds forming the molding die 12. Slide collars 13 and 14 are provided below the front platen 9, and the tie bar 4 and the tie bar 5 are slidably inserted into the slide collar 13 and the slide collar 14, respectively.

  A rear platen 15 is disposed at a position facing the front platen 9. The rear platen 15 is provided with the other mold clamping 12 b of the molding die 12, and slide collars 16 and 17 are provided at the lower part thereof. The tie bar 4 is the slide collar 16, and the tie bar 5 is the slide collar 17. These are slidably inserted.

  Brackets 18 and 19 are provided on the slide collars 13 and 17, respectively, and a first rack member 20 is provided on the bracket 18 so as to extend in the horizontal direction. On the other hand, the bracket 19 is provided with a second rack member 23 extending in the horizontal direction in parallel with the first rack member 20.

  As for the rack members 20 and 23, plate-like rack plates are employed in the present embodiment, but the rack members 20 and 23 are not limited to the rack plates, and may be rack rods formed in a rod shape, for example. . These rack members 20 and 23 are rotatably supported by the movable table 3 and mesh with each other so as to face a pinion (not shown). The rotation of the pinion makes the rack members 20 and 23 have the same length. 1, the front platen 9 and the rear platen 15 are moved toward the parting line PL located between the platens 9 and 15, respectively. And the parting line holding mechanism 24 is comprised by the rack member 20 and 23 and the pinion outside a figure by the structure similar to the past.

  The mold clamping drive mechanism 30 opens and closes and molds the mold 12 by extending and bending a pair of link arms 31 and 32 between the rear platen 15 and the rear support plate 8. Consists of.

  One end of the first link arm 31 is rotatably connected to a bracket 33 attached to the rear platen 15 via a shaft 34. On the other hand, the other end portion of the first link arm 31 is rotatably connected to one of the longitudinal end portions of the rotor 35 formed in a substantially rhombus shape via a shaft 36. One end of the second link arm 32 is rotatably connected to the other longitudinal end of the rotor 35 via a shaft 37.

  The rotor 35 is rotatably supported on the slide block 38 by a drive shaft 39. The slide block 38 is attached upright to slide collars 40 and 41 that are respectively inserted into the tie bars 4 and 5. As shown in FIG. 2, the output shaft 42 a of the electric motor 42 is coupled to the drive shaft 39 of the rotor 35 via a joint 43. The electric motor 42 is fixed to the slide block 38 via a speed reducer 39A. As the electric motor 42, a servo motor that can be easily controlled for rotation can be used.

  The other end of the second link arm 32 is rotatably supported by an eccentric link pin 51 on a bracket 52 having a planar U-shaped bifurcated bearing. One end of a shaft 53 is fixed to the bracket 52. The shaft 53 is inserted into a hollow cylinder 54 provided at the upper end of the rear support plate 8 via a bush 55 so as to be movable in the axial direction.

  A plurality of disc springs 56 that are biasing members of the present invention are inserted into the shaft main body of the shaft 53 while being pressed by the collar 53a of the shaft 53 by the disc spring preload adjusting nut 53b in the cylinder 54. Contained in state. Further, these disc springs 56 are arranged in a partially overlapped state and in a state in which the concave surfaces are faced and combined so that the overlapped ones can be compressed together. Further, at the rear portion of the disc spring 56, a retaining bush 57 fixed to the rear support plate 8 receives the restoring force of the disc spring 56.

  As shown in FIGS. 2 to 4, the eccentric link pin 51 has a first supported shaft portion 51 a and a second supported shaft portion 51 b having the same axis A, and these supported shaft portions. An eccentric shaft portion 51c is provided between 51a and 51b. Further, the eccentric link pin 51 is supported at the first and second supported shaft portions 51 a and 51 b by the bifurcated bearing portions 52 a and 52 b of the bracket 52. The eccentric shaft 51c of the eccentric link pin 51 has an axis B that is eccentric with respect to the axis A by a predetermined dimension. This eccentric dimension varies depending on the clamping force. For example, in the case of the clamping force of 70 kN (kilonewton, the same applies hereinafter) shown in FIG. In the case of a mold clamping force of 40 kN, it is decentered 1 mm to the left with respect to the axis A.

  The eccentric link pin 51 is configured to be rotationally driven by the electric motor 58, and the motor shaft 58 a of the electric motor 58 is connected to the bifurcated joint portion 51 d via the shaft 60. As the electric motor 58, a servo motor that can be easily controlled for rotation can be used. Further, the eccentric link pin 51 is attached with an arrow-shaped azimuth plate 59 that visually indicates whether the axis B of the eccentric shaft 51c is eccentric to the left or right of the axis A. When the arrow of the orientation plate 59 points to the right side as shown in FIG. 1, it indicates that the axis B of the eccentric shaft 51c is eccentric to the right side with respect to the axis A. When pointing to the side, it indicates that the axis B of the eccentric shaft 51c is eccentric to the left side with respect to the axis A.

  Below, operation | movement of the hollow molding apparatus which concerns on this Embodiment is demonstrated.

  First, in order to store the parison hanging from the parting line PL in the split molds 12a and 12b, the electric motor 42 is controlled to rotate in the state shown in FIG. Then, the drive shaft 39 coupled to the output shaft 42a rotates and the rotor 35 rotates. As a result, as shown in FIGS. 5 and 6, the pair of links 31 and 32 are on the same horizontal line. The front support plate 7 and the rear support plate 8 move to the left in FIG. 1, and the rear platen 15 moves to the right in FIG. 1 via the slide collar 16 (17). To do.

  A pair of first rack members is obtained by the movement of the rear platen 15 in the right direction in FIG. 1 and the movement of the front platen 9 in the left direction accompanying the movement of the front support plate 7 in the left direction in FIG. 20 and the second rack member 23 move in directions opposite to each other, and a pinion (not shown) rotates, whereby the movement of the split molds 12a and 12b is equally regulated, and the split molds 12a and 12b are moved to the parting line PL. On the other hand, they approach each other while moving at an equal distance, and become a state as shown in FIG.

  In this way, when the split molds 12a and 12b are brought into contact with each other in the parting line PL and clamped, the parison is accommodated in the cavities of the split molds 12a and 12b, and the slide block is interposed via the slide collars 40 and 41. 38 moves relative to the tie bars 4 and 5, and the second link arm 32 and the bracket 52 are pushed leftward in FIG. 1, and the nut 53 c at the end of the shaft 53 is removed from the end face of the bush 57. Separate. As shown in FIGS. 5 and 6, the collar 53 a of the shaft 53 presses each of the disc springs 56 to bend and deform, so that the restoring force of each of the bent and deformed disc springs 56 makes a straight line. Clamping is performed by pressing the rear platen 15 toward the front platen 9 through the pair of first link arms 31 and second link arms 32.

  Therefore, the split molds 12a and 12b are sandwiched between the front support plate 7 and the rear support plate 8 connected to both ends of the tie bars 4, 5 and 6, and the restoring force based on the compression deformation of each disc spring 56 is obtained. Are clamped together. Here, the elastic energy based on the bending deformation of the front support plate 7, the rear support plate 8, the tie bars 4, 5, 6, etc. when the mold clamping force is generated is balanced with the energy for bending and deforming each disc spring 56.

  Subsequently, when the rotor 35 is rotated in the opposite direction to take out the molded product molded in the split molds 12a and 12b, the first link arm 31 causes the rear platen 15 to move leftward in FIGS. On the other hand, the second link arm 32 pulls the rear support plate 8 rightward in FIGS. 5 and 6, and the split molds 12 a and 12 b are separated from each other at an equal distance by the parting holding mechanism 24. Returning to the state shown in 1, the molded product suspended in the blow pin (not shown) is removed.

  Next, the adjustment operation of the mold clamping force accompanying the change of the molding die in the hollow molding apparatus will be described.

  First, in the state where the mold clamping force generated in the rotor 35 and the pair of link arms 31 and 32 is constant, for example, when the original state is shown in FIG. As shown in FIG. 6, the shaft center B of the eccentric shaft 51c of the eccentric link pin 51 shown in the horizontal direction is eccentric to the left side with respect to the shaft center A, and the mold clamping force is 40KN. In this case, that is, when changing the arrow tip of the azimuth plate 59 so as to turn leftward in the horizontal direction, the eccentric link pin 51 is rotated from the state shown in FIG. 1 by controlling the rotation of the electric motor 58. Thus, when the arrow tip of the azimuth plate 59 is directed leftward in the horizontal direction as shown in FIG. 6, the axis B of the eccentric shaft 51c of the eccentric link pin 51 is eccentric to the left side with respect to the axis A, and the clamping force 40KN It becomes a holding state. Then, when the electric motor 42 is rotated and the pair of link arms 31 and 32 are extended and changed to be in a straight line state, a state as shown in FIG. 6 is obtained. On the other hand, when the holding force of the mold clamping force in the state shown in FIG. 6 is changed to the holding force of the mold clamping force shown in FIG. 5, it can be achieved by performing an operation reverse to the above.

  7A shows the compression state of each disc spring 56 at the rotational position of the eccentric link pin 51 shown in FIG. 5, and FIG. 7B shows the rotation of the eccentric link pin 51 shown in FIG. The compression state of the disc spring 56 in the position is shown. At this time, the end surface of the collar 53a of the shaft 53 shown in FIG. 7A and the same end surface of the collar 53a of the shaft 53 shown in FIG. 7B are separated by the dimension L in the drawing, that is, 2 mm. It is in a state.

It is the front view which showed the mold open state of the hollow molding apparatus which concerns on embodiment of this invention, and represented one part in the cross section. It is the top view which showed the mold clamping drive mechanism of the same hollow shaping | molding apparatus, and represented a part in cross section. It is a top view which shows an eccentric link pin. It is a front view which shows the eccentric link pin. It is the front view which showed the mold clamping state whose mold clamping force is 70 kN in the hollow molding apparatus which concerns on embodiment of this invention, and represented one part in the cross section. It is the front view which showed the mold clamping state whose mold clamping force is 40 kN in the hollow molding apparatus which concerns on embodiment of this invention, and represented one part in the cross section. (A) It is a principal part expanded sectional view which shows the urging | biasing means in the mold clamping state shown in FIG. (B) It is a principal part expanded sectional view which shows the urging | biasing means in the mold clamping state shown in FIG. It is a front view which shows the outline of the conventional hollow molding apparatus.

Explanation of symbols

4, 5, 6 ... tie bar 7 ... front support plate 8 ... rear support plate 9 ... front platen 12 ... molding die 15 ... rear platen 30 ... mold clamping drive mechanism 31 ... first link arm 32 ... second link arm 35 ... Rotor 42 ... Electric motor 51 ... Eccentric link pin 51c ... Eccentric shaft 52 ... Bracket 53 ... Shaft 56 ... Belleville spring

Claims (3)

A front support plate and a rear support plate fixed to both ends of the tie bar extending in the horizontal direction;
A front platen located between the plates and attached to the front support plate and a rear platen slidably provided on the tie bar;
A mold comprising a pair of split molds attached to both platens;
A mold clamping drive mechanism for opening and closing the mold and clamping the mold by extending and bending a pair of link arms disposed between the rear platen and the rear support plate;
The mold clamping drive mechanism includes: a bracket that rotatably supports a rear end portion of the link arm on the rear support plate side of the pair of link arms by an eccentric link pin;
A shaft having a tip fixed to the bracket and supported by the rear support plate so as to be movable in the axial direction;
A hollow molding apparatus comprising: a plurality of disc springs that are elastically fitted to the shaft and change a clamping force by changing a load capacity depending on an eccentric position of the eccentric link pin. The bracket has a bifurcated bearing portion that rotatably supports the eccentric link pin, the supported shaft portion that the eccentric link pin supports on the bifurcated bearing portion, and a shaft that is eccentric with respect to the shaft center. The hollow molding apparatus according to claim 1, further comprising an eccentric shaft portion having a center. The mold clamping drive mechanism includes a rotor having a pair of long end portions and a pair of short end portions that are rotated by an electric motor, and the pair of long end portions of the rotor are mutually connected with respect to the rotation center of the rotor. The hollow molding apparatus according to claim 1 or 2, wherein the ends of the pair of link arms are rotatably coupled to each other.

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