JPH042036Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Technical field The present invention relates to a gripping device for a parison or a hollow molded product.

(B) Prior art A gripping device for a parison or a hollow molded product is used to hold a parison or a hollow molded product during injection stretch blow molding when the parison or a hollow molded product is transported for molding, heating, removal, etc.
This is a device that grips the mouth of a parison or hollow molded product. Conventionally, a parison or hollow molded product gripping device as shown in FIG. 1 has been used. That is, three pawls 12 are jointed to the lower end of the piston 10 at equal intervals on the inner circumference, and the port 1
When compressed air is supplied from 4, the piston 10 descends, and the inclined portion 12a of the pawl 12 rides on the inclined portion 16a of the core 16, causing the pawl 12 to open. In this state, when the entire parison or hollow molded product gripping device is lowered by a lifting cylinder (not shown), the lower end of the pawl 12 comes into contact with the stationary pawl contact plate 18, and the pawl 12 It is pushed into the cylinder 20. Note that at this time, the supply of air pressure to the port 14 is stopped. Claw 1
2 is pushed into the cylinder 20, the pawl 1
The inclined portion 12b of No. 2 is the inclined portion 20 of the cylinder 20.
a, the pawl 12 is closed, and the mouth portion 22a of the parison or hollow molded product 22 is gripped. In this state, compressed air is supplied to the port 24, and the parison or hollow molded product gripping device is moved while holding the parison or the hollow molded product 22. After moving to a predetermined position, the parison or hollow molded article 22 is released by a reverse operation to that described above.

However, such conventional gripping devices for parisons or hollow molded products have the following problems.
In other words, such conventional gripping devices for parisons or hollow molded products are heavy (approximately
3.5Kg), if a large number of parisons or hollow molded products are to be taken out, the entire device becomes heavy, and the strength of the member that supports the gripping device for the parison or hollow molded product must also be increased. It is also necessary to use a large cylinder for moving the product gripping device, which increases the size and price of the entire device. Further, this conventional parison or hollow molded product gripping device itself was expensive. This is because the pawls are opened and closed by sloped surfaces, which requires highly accurate machining of the sloped surfaces. In addition, the conventional gripping device uses an inclined portion to mechanically move the claws, which generates relatively high noise. Further, conventional gripping devices can only grip parisons or hollow molded products that have an annular protrusion at the mouth, and if the gripping force is too strong, the mouth may be damaged.
In addition, when such a conventional gripping device is applied to a stretch blow molding part, the center of the guide rod is formed hollow, and the stretch rod is placed there as well as a compressed air introduction hole to introduce high pressure air into the inside of the parison. In order to prevent high-pressure air from leaking between the tip of the guide rod 26 and the inner diameter of the mouth 22a of the parison or hollow molded product 22, an O-ring is attached to the outer periphery of the tip of the guide rod 26. However, there is a problem in that this O-ring is damaged relatively early and has insufficient durability, and fragments of the damaged O-ring can enter the inside of the hollow molded product. This problem is particularly noticeable in containers such as eye drop containers and cosmetic containers where the mouth portion 22a has a small diameter.

(C) Purpose of the invention The present invention is a compact, lightweight, low-noise material that can grip parisons or hollow molded products with any mouth shape without damaging them, and which also has a very small mouth diameter. It can also be applied to molded products. The object is to obtain a gripping device for a parison or a hollow molded product.

(d) Structure of the invention The gripping device for a parison or a hollow molded product according to the present invention has an inner diameter slightly larger than the outside diameter of the mouth of the parison or hollow molded product in a free state where no compressive force is applied. an annular elastic member that deforms toward the center so that the inner diameter becomes smaller than the outer diameter of the mouth of the parison or hollow molded product when a compressive force is applied with the chisel open; and an elastic member whose outer periphery is restrained. and a pressurizing device capable of applying compressive force to.

(E) Example The following is an example of the present invention as shown in the second and third figures of the attached drawings.
This will be explained based on the diagram.

(First Embodiment) FIG. 2 shows a first embodiment of the present invention. A substantially cylindrical cylinder 34 is attached to the base plate 30 with bolts 32 and a fixing plate 33. Further, a guide rod 36 is attached to the base plate 30 in a stepped shape.
The guide rod 36 is arranged concentrically with the cylinder 34, and the piston 37 is fitted into an annular gap formed by the two. In addition,
The outer diameter of the tip 36a of the guide rod 36 is sized to fit into the inner diameter of the mouth 37a of the parison or hollow molded product 38. The inner diameter side of the piston 37 is sealed by a seal member 40. A step is formed on the outer diameter portion of the piston 37 by a large diameter portion 37a and a small diameter portion 37b.
7a and the small diameter portion 37b are each a seal member 42.
and is sealed by a seal member 44. Further, the space between the base plate 30 and the cylinder 34 is sealed by a seal member 45. Air pressure can be supplied and discharged to the upper end surface of the piston 37 via a passage 48 by a solenoid valve 46, and a passage 50 is provided between the large diameter part 37a and the small diameter part 37b of the piston 37. Air pressure can be supplied and discharged by a solenoid valve 46. Note that the joint portion of the passage 50 between the base plate 30 and the cylinder 34 is sealed by a sealing member 52. cylinder 3
4, a gripper rubber 54, which is an elastic member, is supported at the lower part in the figure. The gripper rubber 54 has its outer periphery, lower end surface, and part of its upper end surface restrained by the cylinder 34, and the lower end of the piston 37 is in contact with the remaining portion of the upper end surface. In its free state, the grip rubber 54 has an inner diameter slightly larger than the outer diameter of the mouth portion 38a of the parison or hollow molded product 38. However, when pressure is applied from the piston 37, the gripper rubber 54 is deformed toward the center as described later, and its inner diameter becomes smaller. Note that a desired number of gripping devices configured as described above can be installed on one base plate 30.

Next, the operation of this embodiment will be explained. The base plate 30 is connected to a conveyance device of an injection stretch blow molding apparatus, and is movable in the vertical direction and the horizontal direction. When the gripping device for the parison or hollow molded article is raised, air pressure is not supplied to the passage 48, but on the contrary, air pressure is supplied to the passage 50. That is, the piston 37 does not apply compressive force to the gripper rubber 54. When the base plate 30 is lowered in this state, the tip 36a of the guide rod 36 is first placed at the mouth 38a of the parison or hollow molded product 38 placed below.
It fits into the inner diameter of the The tip end 36a of the guide rod 36 is the parison or the mouth part 3 of the hollow molded product 38.
By fitting into the inner diameter of 8a, the position of the parison or hollow molded part 38 is corrected so that it is concentric with the guide rod 36. Next, when the solenoid valve 46 is switched to discharge the air pressure from the passage 50 and supply air pressure to the passage 48, a downward force in the figure acts on the piston 37, and the gripper rubber 54 is compressed by this force. Since the grip rubber 54 is subjected to compressive force from above and below while its outer peripheral portion is restrained, it can deform only toward the inner diameter, and deforms in a direction that reduces the inner diameter.
Therefore, the mouth portion 38a of the parison or hollow molded product 38 is gripped by the inner diameter portion of the gripper rubber 54. In this state, the entire gripping device for the parison or hollow molded product is raised, then moved horizontally, and lowered again, and at the next process position, the solenoid valve 4
6 is switched to the initial state again, and the air in the passage 48 is discharged and air pressure is supplied to the passage 50. Then, the compressive force by the piston 37 is applied to the gripper rubber 5.
4, the deformation of the gripper rubber 54 toward the center is eliminated, and the gripping force of the gripper rubber 54 is no longer applied. Therefore, the parison or hollow molded article 38 is released from the gripping device, and the movement of the parison or hollow molded article 38 is completed. The gripping device then rises again and moves horizontally,
Return to initial position.

As described above, the parison or hollow molded product gripping device according to the present invention has a simple structure and does not require claws or the like as in the conventional gripping device, so that the weight of the gripping device can be reduced. For example, in the case of 8 pieces, the conventional gripping device shown in FIG.
It became. In other words, the weight is less than 1/10. Furthermore, since the structure is simple and no parts with complicated shapes are required, the price can be reduced. In other words, the price can be reduced to about 50% compared to conventional ones. Further, since the gripping operation is performed by deforming the gripper rubber 54, which is an elastic member, no noise is generated. Furthermore, even if the parison or hollow molded product 38 does not have a projection on the mouth part 38a, it can be gripped securely without damaging the mouth part 38a.

(Second Embodiment) FIG. 3 shows a second embodiment of the present invention. In this embodiment, the present invention is applied to a gripping device for a stretch blow molding part. In the stretch blow molding section, the parison is stretched by a stretching rod and high pressure air is blown into the inside of the parison. For this reason, in the second embodiment shown in FIG. 3, the guide rod 60 is hollow, and the stretching rod 62 is disposed in the hollow portion. Further, high pressure air can be supplied and discharged from a solenoid valve 66 through a passage 64 to this hollow portion. Furthermore, in order to prevent the high-pressure air supplied into the parison 68 from leaking, a sealing member 72 is provided on the lower end surface of the cylinder 70, thereby sealing the gap between the hollow molding die 74 and the cylinder 70. It's meant to be sealed. Further, the piston 76 has a structure in which there is no step on the outer diameter portion. A passage 8 is connected to the upper end surface of the piston 76 by a solenoid valve 78.
Air pressure can be supplied and discharged via 0. The gripper rubber 54 is similar to that of the first embodiment shown in FIG.

When gripping the parison, the solenoid valve 78 supplies air pressure to the passage 80, while the solenoid valve 66 opens the passage 64. By doing so, a pressing force is applied to the gripper rubber 54 by the piston 76, and the parison 68 can be gripped in the same manner as in the above case. After moving the parison 68 gripped in this way to the stretch blow molding section,
The solenoid valve 78 is switched to discharge the air pressure in the passage 80, and at the same time the solenoid valve 66 is switched to discharge the air pressure from the parison 68 through the passage 64 and the hollow part of the guide rod 60.
Blow high pressure air into the inside of the. This parison 68
The high pressure air blown into the piston 76
Since an upward force is applied to the gripper rubber 54 and no pressure is applied to the gripper rubber 54, the inner diameter of the gripper rubber 54 is expanded and the parison 68 is released. The lowering of the stretching rod 62 and the high pressure air supplied to the inside of the parison 68 performs the well-known stretch blow molding. In the case of this embodiment, in addition to obtaining the same functions and effects as those of the first embodiment, an O-ring is used to connect the tip 60a of the guide rod 60 and the inner diameter of the mouth 68a of the parison 68. There is no need to seal it. Therefore, there is no problem with the durability of the O-ring, and there is no fear that fragments of the damaged O-ring will enter the inside of the hollow molded product. Further, since no space is required for arranging an O-ring, stretch blow molding can be performed even if the container has a smaller opening.

(F) Effect of the invention As explained above, the device for gripping a parison or hollow molded product according to the present invention, in a free state where no compressive force is applied, has a gripping device that is slightly smaller than the outside diameter of the mouth of the parison or hollow molded product. An annular elastic member that has a large inner diameter and deforms toward the center so that the inner diameter becomes smaller than the outer diameter of the mouth of the parison or hollow molded product when compressive force is applied with only the inner diameter open. In the embodiment, gripper rubber 54) and a pressure device (in the described embodiment, cylinders 34, 70 and piston 3) capable of applying compressive force to an elastic member whose outer periphery is restrained
7, 76), the device is lightweight, the cost is reduced, no noise is generated, and even parisons or hollow molded products that do not have protrusions at the mouth can be reliably gripped. There is no damage to the mouth part, and in addition, there is no need to provide an O-ring to seal between the guide rod tip and the parison mouth part in the stretch blow molding part, improving durability. It becomes possible to carry out stretch blow molding of smaller diameter hollow molded products.

[Brief explanation of the drawing]

Fig. 1 shows a conventional parison or hollow molded product gripping device, Fig. 2 shows a parison or hollow molded product gripping device according to the present invention, and Fig. 3 shows a second embodiment of the present invention. It is a diagram. 30...base plate, 32...bolt, 3
4,70...Cylinder, 36,60...Guide rod, 37,76...Piston, 38,68...
...Parison or hollow molded product, 46,66,78...
...Solenoid valve, 54...Gripper rubber (elastic member),
62...Stretching rod.

Claims (1)

[Scope of utility model registration request] In the free state, the inner diameter is slightly larger than the outside diameter of the mouth of the parison or hollow molded product, and when compressive force is applied with only the inside diameter open, the inside diameter is slightly larger than the outside diameter of the mouth of the parison or hollow molded product. A gripping device for a parison or a hollow molded product, which includes an annular elastic member that deforms toward the center so that the outer periphery of the elastic member is reduced, and a pressurizing device that can apply compressive force to the elastic member whose outer periphery is restrained.