JP7096483B2 - Molding equipment - Google Patents

Description

The present invention relates to a molding apparatus.

Patent Document 1 discloses a hollow molding apparatus capable of easily and surely adjusting the mold clamping force of a molding die by using a mold clamping drive mechanism.

Japanese Unexamined Patent Publication No. 2010-110995

However, in the hollow forming apparatus disclosed in Patent Document 1, it is necessary to change the load on a plurality of disc springs via the shaft, which complicates the mechanism.

The present invention has been made in view of such circumstances, and provides a molding apparatus capable of making the mold clamping force applied to a split die uniform by a simple mechanism.

According to the present invention, it is a molding apparatus including a pair of split dies and a mold clamping device, and the mold clamping device divides a mold clamping force via a plurality of elastic members arranged in parallel. Molding equipment is provided that is configured to be added to the mold.

The molding apparatus according to the present invention includes a pair of split dies and a mold clamping device. Further, the mold clamping device is configured to apply a mold clamping force to the split mold via a plurality of elastic members arranged in parallel. As a result, the split die is pressed by the plurality of elastic members arranged in parallel, so that the force applied to the split die can be made uniform.

Hereinafter, various embodiments of the present invention will be illustrated. The embodiments shown below can be combined with each other.
Preferably, the mold clamping device comprises a plate, the plurality of elastic members are arranged between the plate and the split mold, and the mold clamping device has the split mold with respect to the plate. It is configured to apply a clamping force in the closing direction.
Preferably, the mold clamping device includes a shaft, and the shaft is configured to apply the mold clamping force to the plate.
Preferably, at least two of the plurality of elastic members are arranged point-symmetrically with respect to the axis of the shaft.
Preferably, the number of the plurality of elastic members is four or more.
Preferably, the plurality of elastic members include a first elastic member and a second elastic member, the elastic coefficient of the first elastic member is the first elastic coefficient, and the elastic coefficient of the second elastic member is the second elasticity. It is a coefficient, and the first elastic coefficient is larger than the second elastic coefficient.
Preferably, the value of (first elastic modulus / second elastic modulus) is 1.5 to 3.

It is a perspective view of the molding apparatus 1 of one Embodiment of this invention. It is a perspective view of the molding apparatus 1 of one Embodiment of this invention. It is a perspective view of the plate 21B. It is a perspective view which shows the positional relationship between a plate 21B, an elastic member 22, and a shaft 23. It is a plan view seen from the X direction of FIG. It is a perspective view of the mold 3A. It is a front view of the molding apparatus 1, and is the figure which shows the state which the parison P is hung down from the extruder 5. In addition, in order to improve visibility, the shaft AX, the nut NT, the guide shaft 24, the support column 26, and the motor 4 are omitted. Further, the split mold 3 is shown in an end view passing through the center. The same applies to FIGS. 8 and 9. It is a figure which shows the state that the mold clamping force in the direction which closes a split mold 3 is applied to the plate 21A by the mold clamping device 2. It is a figure which shows the state which the mold clamping force is further applied to the plate 21A from the state of FIG. It is a schematic diagram in the case where the molding apparatus 1 is applied to the rotary type blow molding apparatus.

Hereinafter, embodiments of the present invention will be described. The various features shown in the embodiments shown below can be combined with each other. In addition, the invention is independently established for each characteristic item.

1. 1. Molding device 1
As shown in FIGS. 1 and 2, the molding apparatus 1 according to the embodiment of the present invention includes a pair of split dies 3 and a mold clamping device 2. In the present embodiment, the split mold 3 is composed of the mold 3A and the mold 3B.

1-1. Mold clamping device 2
The mold clamping device 2 includes a plurality of elastic members 22 arranged in parallel. Further, in the present embodiment, the mold clamping device 2 includes a plate 21. Further, in the present embodiment, the mold clamping device 2 includes a shaft 23.

In this embodiment, the plate 21 includes plates 21A to 21E. These plates 21 are connected by a guide shaft 24, and the plates 21A, 21B, and 21D are configured to be relatively movable along the guide shaft. In the present embodiment, a plurality of plates 21 are connected by the support column 26 via the guide shaft 24. Of these, the plate 21A includes a nut NT for holding the shaft AX, as shown in FIG. In the present embodiment, the plate 21A is provided with holes (not shown) through which the six shafts AX are inserted, and the shafts AX inserted through the holes are held by nuts NT. As will be described later with reference to FIGS. 7 to 9, such a hole prevents the shaft AX and the plate 21A from interfering with each other during the mold clamping of the mold clamping device 2. Further, as shown in FIG. 3, the plate 21B is formed with a notch 21K, a relief hole 21H, and a recess 21O. The notch 21K is for introducing an air nozzle, a water cooling pipe, or the like (not shown) into the split mold 3. Further, the escape hole 21H is for preventing interference with the shaft 23. Therefore, the diameter of the escape hole 21H is configured to be larger than the diameter of the shaft 23. In the present embodiment, the escape hole 21H has a recessed shape formed in the plate 21B, but an escape hole 21H having a through hole shape penetrating the plate 21B may be formed. Further, the recess 21O is provided at a position corresponding to the elastic member 22. This is for stably attaching the elastic member 22 to the plate 21B, but it is not an essential configuration.

Further, as shown in FIGS. 4 and 5, the plurality of elastic members 22 include a first elastic member 22A and a second elastic member 22B. Here, the elastic coefficient of the first elastic member 22A is the first elastic coefficient, and the elastic coefficient of the second elastic member 22B is the second elastic coefficient. In this embodiment, the first elastic modulus is configured to be larger than the second elastic modulus. The value of (first elastic modulus / second elastic modulus) is preferably 1.5 to 3. It is more preferably 1.7 to 2.8, and even more preferably 1.9 to 2.6. Specifically, for example, the values of (first elastic modulus / second elastic modulus) are 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.1, 2.2. , 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3 and within the range between any two of the values exemplified here. May be good. Further, the shaft AX is inserted through the center of the elastic member 22.

Then, as shown in FIGS. 1 and 2, the plurality of elastic members 22 are arranged between the plate 21A and the split mold 3. As shown in FIGS. 4 and 5, at least two of the plurality of elastic members 22 are arranged point-symmetrically with respect to the axis of the shaft 23. In this embodiment, all elastic members 22 are arranged point-symmetrically with respect to the axis of the shaft 23. The number of the first elastic member 22A and the second elastic member 22B is not particularly limited, but it is preferable to provide four or more elastic members 22 in order to make the force applied to the split mold 3 uniform. Further, it is preferable to arrange four or more elastic members 22 at positions corresponding to the vertices of the quadrangle centered on the axis of the shaft 23. In addition, it is preferable to arrange the first elastic member 22A around the axis of the shaft 23 and arrange the second elastic member 22B between the first elastic members 22A. Here, in the present embodiment, the four first elastic members 22A and the two second elastic members 22B are arranged. Then, the two second elastic members 22B are arranged between the two first elastic members 22A, respectively. The arrangement of the second elastic member 22B is not limited to this, and may be arranged between the vertically arranged first elastic members 22A.

Further, the mold clamping device 2 is configured to apply a mold clamping force to the split mold 3 via a plurality of elastic members 22 arranged in parallel. In the present embodiment, the mold clamping device 2 is configured to apply a mold clamping force in the direction of closing the split mold 3 to the plate 21A. Further, in the present embodiment, the shaft 23 is configured to apply a mold clamping force to the plate 21A. Hereinafter, a specific description will be given. For example, the shaft 23 can be configured by a ball screw. Then, as shown in FIGS. 1 and 2, the shaft 23 can be rotated by the rotation of the motor 4, and the nut 25 attached to the shaft 23 can be moved in the axial direction of the shaft 23. Then, by moving the nut 25 toward the split mold 3, the plate 21A is pressed in the split mold 3 directions via the shaft 23, and the plate 21B is pressed in the split mold 3 directions via the plurality of elastic members 22. Is pressed against. As a result, the mold 3A moves to the right in the drawing. Similarly, the motor 4 presses the plate 21D in the three directions of the split mold via the shaft 23. As a result, the mold 3B moves to the left in the drawing.

1-2. Split mold 3
Hereinafter, the split mold 3 will be described with reference to FIG. In this embodiment, since the mold 3A and the mold 3B have the same shape, the mold 3A will be described. As shown in FIG. 6, the split mold 3A has a cavity 31 and recesses 33 above and below the cavity 31. Further, the portion between the cavity 31 and the recess 33 functions as the pinch-off portion 32. Then, by shaping the parison P into a shape along the inner surface of the cavity 31, it is possible to form a molded body.

2. 2. Operation of Molding Device 1 Hereinafter, the operation of the molding device 1 will be described with reference to FIGS. 7 to 9. First, as shown in FIG. 7, the cylindrical parison P in a molten state is extruded from the extruder 5, and the parison P is set between the split molds 3 for blow molding.

Next, as shown in FIG. 8, the mold clamping device 2 applies a mold clamping force in the direction of closing the split mold 3 to the plates 21A and the plate 21D to close the split mold 3. At this time, the parison P is cut off by the pinch-off portion 32 of the split mold 3, and the burr B is formed.

Next, as shown in FIG. 9, the elastic member 22 is compressed by further applying a mold clamping force to the plates 21A and 21D from the state of FIG. As a result, the lengths of the plurality of elastic members 22 are shortened by D as compared with the state of FIG. Here, in the present embodiment, as shown in FIGS. 4 and 5, since the plurality of elastic members 22 are arranged point-symmetrically with respect to the axis of the shaft 23, the mold clamping force is evenly applied to the plate 21B. Can be added. As a result, an even mold clamping force is applied to the entire pinch-off portion 32 of the split mold 3. Therefore, the misalignment of the split die 3 is reduced, and the cut-off performance of the parison P by the pinch-off portion 32 is improved. Then, an air nozzle (not shown) is introduced into the split mold 3 from the notch 21K of the plate 21B, and blow molding is performed by injecting air into the inside of the parison P. At this time, the parison P is pressed against the inner surface of the cavity 31 of the split mold 3.

Here, when the first elastic modulus of the first elastic member 22A is 150 (N / mm) and the second elastic modulus of the second elastic member 22B is 70 (N / mm), the elastic member 22 is compressed by 10 mm. Then, the mold clamping force of the molding apparatus 1 becomes "150 × 10 × 4 + 70 × 10 × 2 == 7,400N".

Finally, the split mold 3 is opened and the blow-molded hollow molded body is taken out. Such a molded body has a shape corresponding to the cavity 31 of the split mold 3.

As described above, in the molding apparatus 1 according to the present embodiment, since the split die 3 is pressed by the plurality of elastic members 22 arranged in parallel, the force applied to the split die 3 can be made uniform. can. Specifically, since the mold clamping force is evenly applied to the entire pinch-off portion 32 of the split mold 3, the misalignment of the split mold 3 is reduced and the parison P is cut off well. Further, unlike the molding apparatus 1 of the present embodiment, in a configuration in which a plurality of elastic members 22 are not provided in parallel, it is possible to measure the load of the motor, but it is possible to measure the mold clamping force. It was difficult. On the other hand, in the present embodiment, it has become possible to estimate the mold clamping force of the molding apparatus 1 from the compression amount of the elastic member 22. The amount of compression of the elastic member 22 can be calculated from the rotation speed or moving distance of the nut 25, the distance between the plates, the position, and the like.

3. 3. Rotary blow molding device 10
Next, an example in which the molding apparatus 1 is applied to the rotary blow molding apparatus 10 will be described with reference to FIG. FIG. 10 is a schematic view of a rotary blow molding device 10 in which a plurality of molding devices 1 viewed from the Y direction of FIG. 2 are arranged around a center of rotation. As shown in FIG. 10, a plurality of molding devices 1 are arranged around the center of rotation, and while rotating the rotary wheel, the parison P is extruded from the extruder 5, and in each of the plurality of split dies 3 provided on the rotary wheel. By blow molding the parison P, a molded product can be continuously formed.

Here, in general, when the split mold 3 is molded and opened while rotating using a rotary type blow molding device, it is compared with blow molding which is not a rotary type (the split mold is not moving). And, the mold tightening tends to vary. However, when the molding apparatus 1 according to the embodiment of the present invention is applied to the rotary blow molding apparatus 10, the elastic member 22 can press the pinch-off portion 32 as a whole, so that the mold by the pinch-off portion 32 can be pressed. It is possible to reduce the occurrence of poor adhesion and poor quality such as pinch cracking at the bottom of the molded product due to weak tightening force.

Further, in the rotary type blow molding apparatus, since molding is performed while continuously extruding the parison, it is necessary to separate the molded body at the pinch-off portion. Therefore, it is necessary to increase the mold clamping force in order to reliably separate the molded body, but if the mold clamping force is large, the load on the pinch-off portion of the split die becomes large. Therefore, it is preferable to appropriately adjust the mold clamping force according to the molding conditions (material, wall thickness, etc.). Here, when the molding apparatus 1 according to the embodiment of the present invention is applied to the rotary blow molding apparatus 10, the mold clamping force can be calculated from the compression amount of the elastic member 22, so that the mold clamping force can be easily adjusted. ..

<Others>
The present invention can also be implemented in the following aspects.
An embodiment in which elastic members having the same elastic modulus are used as a plurality of elastic members 22.
-Six first elastic members 22A are arranged sideways in a square shape of 3 rows × 2 columns, and an arbitrary number of second elastic members 22B are arranged between them.
The elastic member 22 is connected to the plate 21A and the plate 21B, or to only one of the plate 21A and the plate 21B.
-The elastic member 22 is directly pressed against the split die 3 without using the plate 21B.
-The elastic member 22 is pressed by a member having another shape instead of the plate 21A.
A plurality of elastic members 22 are also provided on the plate 21E side.
-Instead of the motor 4 and the shaft 23, a mold clamping force is applied by a cylinder mechanism. The mold 3B on the side without the elastic member 22 is interlocked with the motor 4 on the elastic member 22 side, and the mechanism is such that the motor 4 on the mold 3B side is not provided (example: rack & pinion).
-The mold 3B on the side without the elastic member 22 is fixed (immovable) (only pressed from the elastic member 22 side).

1: Molding device 2: Mold clamping device 3: Split mold 3A: Mold 3B: Mold 4: Motor 5: Extrusion device 10: Rotary blow molding device 21: Plate 21A: Plate 21B: Plate 21C: Plate 21D: Plate 21E: Plate 21H: Relief hole 21K: Notch 21O: Recess 22: Elastic member 22A: First elastic member 22B: Second elastic member 23: Shaft 24: Guide shaft 25: Nut 26: Strut 31: Cavity 32: Pinch-off portion 33: Recessed AX: Shaft NT: Nut B: Bali P: Parison

Claims (5)

A rotary blow molding device in which a plurality of molding devices including a pair of split dies and a mold clamping device are arranged around a center of rotation, and molding is performed while continuously extruding a parison .
Each molding apparatus is configured to perform mold clamping and mold opening of the pair of split dies while rotating by the mold clamping device.
The mold clamping device is configured to apply a mold clamping force to the split mold via a plurality of elastic members arranged in parallel.
The mold clamping device includes a plate, a shaft, and a guide shaft.
The plurality of elastic members are arranged between the plate and the split mold.
The shaft is configured to apply a mold clamping force in the direction of closing the split mold to the plate.
The plate is configured to be movable along the guide axis.
The guide shaft is arranged on the rotation center side of the shaft, and the pair of split dies are arranged on the side opposite to the rotation center of the shaft.
The mold clamping device performs mold clamping and mold opening by moving the pair of split dies in a direction parallel to the rotation axis of the molding apparatus .
Rotary blow molding equipment. At least two of the plurality of elastic members are arranged point-symmetrically with respect to the axis of the shaft.
The rotary blow molding apparatus according to claim 1 . The number of the plurality of elastic members is four or more.
The rotary blow molding apparatus according to claim 1 or 2 . The plate comprises a notch for introducing an air nozzle and a water cooling tube into the split mold.
The rotary blow molding apparatus according to any one of claims 1 to 3. The rotary blow molding apparatus according to any one of claims 1 to 4, wherein the plate includes a recess for stably mounting the elastic member.

Images