JPH09169027A - Underwater granulation apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect the fastening state of a water chamber at times of fastening and operation. SOLUTION: A plurality of piezoelectric elements 13 are embedded in the attaching surface of the water chamber 4 coming into contact with the die surface 3a of a die 3 in the circumferential direction thereof and, when the water chamber 4 is fastened to the die 3 by a bolt 7, surface pressure is detected by the piezoelectric elements 13 to judge whether prescribed fastening pressure is generated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an underwater granulator, and more particularly to a water chamber of the underwater granulator.

[0002]

2. Description of the Related Art Conventionally, for example, a configuration shown in FIG. 3 has been adopted as an underwater granulating apparatus. That is, in the figure, what is indicated by reference numeral 1 is an underwater granulating apparatus, and this underwater granulating apparatus 1 is fixed to a die 3 attached to a cylinder head 2 of an extruder via a water chamber 4. ing.

That is, one side of the water chamber 4 is detachably fixed to the die 3 by the bolt 7, and the housing 15 of the cutter driving device 5 is fixed by the bolt 53 to the other side. . A cooling water inlet 8 and a cooling water outlet 9 are provided below the water chamber 4 and above the water chamber 4, so that the water chamber 4 is always filled with warm water.

A sleeve 52 is housed in the housing 15 of the cutter driving device 5 so as to be movable in the axial direction by a predetermined distance, and the cutter driving shaft 1 is housed in the sleeve 52.
2 is coaxially rotatable and is held immovable relative to the sleeve 52 in the axial direction (longitudinal direction).

A cutter holder 10 that rotates together with the cutter drive shaft 12 is held at the tip of the cutter drive shaft 12. A plurality of cutter knives 11 are radially fixed and held on the end surface of the cutter holder 10 facing the die 3, and each of the cutter knives 11 is arranged to face the die surface 3a of the die 3. There is. In recent years, in order to improve work efficiency, a tightening mechanism for the water chamber 4 using hydraulic pressure or spring pressure is being adopted instead of the manual tightening of the bolt 7.

[0006]

In the conventional underwater granulator, since the water chamber tightening mechanism is constructed as described above, the following problems exist. That is, in any tightening mechanism, it was not possible to determine whether or not the tightening was performed uniformly and above the specified value. If it is not tightened uniformly and more than the specified value, the plurality of cutter knives that are radially fixed and held at the tip of the cutter drive shaft rotate without evenly contacting the die surface, and the die nozzle There is a problem that the molten resin extruded in a string shape from the blade cannot be uniformly cut, the pellet shape cut is not uniform, and the life of the cutter knife is shortened. Further, the tightening mechanism using hydraulic pressure or spring pressure starts operation in a state where it cannot be determined whether the water chamber and the die are sufficiently tightened due to the timing of automatic start. Therefore, if the tightening pressure is insufficient or uneven, hot water (60 to 80 degrees) may enter the water chamber, and then hot water may leak from the contact surface between the water chamber and the die. further,
Similarly, if the tightening pressure drops for some reason during operation, there was a safety problem.

The present invention has been made to solve the above problems, and provides an underwater granulating apparatus capable of detecting the tightened state of a water chamber during tightening and during operation. The purpose is to do.

[0008]

An underwater granulating apparatus according to the present invention is characterized in that a plurality of piezoelectric elements for detecting a tightening surface pressure are embedded in a circumferential direction of a mounting surface on a die side of a water chamber. To do.

An O-ring is preferably provided inside the piezoelectric element.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described with reference to the drawings. It should be noted that the same or equivalent parts as those of the conventional example are designated by the same reference numerals for description. FIG. 1 is a configuration diagram of an underwater granulation apparatus according to the present invention, and FIG. 2 is an enlarged view of a main part of FIG. That is, what is indicated by reference numeral 1 in FIG. 1 is an underwater granulating device, and this cutter driving device 5 is attached to a cylinder head 2 for circumferentially distributing molten resin extruded from a cylinder of an extruder (not shown). The die 3 is fixed to the die 3 via a water chamber 4.

The die 3 is disk-shaped, and a number of nozzles 6 penetrating in the axial direction are provided in a ring-shaped region surrounding the center thereof. One end of the nozzle 6 opens into the ring-shaped resin passage 2a of the cylinder head 2, and the other end opens into the water chamber 4.

One side of the water chamber 4 is usually detachably fixed to the die 3 by four bolts 7, and the housing 15 of the cutter driving device 5 is fixed to the die 3 by bolts 53 on the other side. ing.

A plurality of piezoelectric elements 13 for detecting the tightening surface pressure are embedded in the circumferential direction of the mounting surface of the water chamber 4 on the die 3 side. The piezoelectric element 13
Is preferably the same as the number of the bolts 7. Further, an O-ring 14 is arranged inside the piezoelectric element 13. A cooling water inlet 8 and a cooling water outlet 9 are provided in the lower portion and the upper portion of the water chamber 4 so that the water chamber 4 is always filled with warm water.

In the housing 15 of the cutter driving device 1, a sleeve 52 is incorporated via an O-ring 50 and a plurality of packings 51 so as to be movable by a predetermined distance in the axial direction. A pair of shaft sealing devices 5
The cutter drive shaft 12 through the four and a pair of bearings 55,
It is coaxially rotatable and is held immovable relative to the sleeve 52 in the axial direction (longitudinal direction).

The cutter drive shaft 12 has a tip end projecting into the water chamber 4, which rotates together with the cutter drive shaft 12 via a bolt 10a and a key 10b, and detachably holds a cutter holder 10, which has a rear end portion. A drive device (not shown) is connected to the shaft via a shaft joint (not shown) slidable in the axial direction.

A plurality of cutter knives 11 are radially fixed and held on the end surface of the cutter holder 10 facing the die 3, and each cutter knife 11 is provided with a die surface 3a of the die 3, that is, a nozzle 6. It is arranged so as to face the surface of the ring-shaped region.

The sleeve 52 forms a piston cylinder together with a rear lid 63 between the sleeve 52 and the rear portion 15a of the housing 15 with the rear portion 52a as a piston. The first cavity 58 formed on both sides of the rear portion 52a of the sleeve 52 has a first hole 58, and the second cavity 57 has a second hole 58.
A hole 59 is formed so as to communicate with each other, and the holes 58 and 59 are connected to a pressure medium source 68 via various valves.

The ring-shaped rear lid 63 is attached to the rear end 15b of the housing 15 through a bolt 64, and a screwing portion 63a formed on the inner diameter portion of the rear lid 63.
A stopper 66 having an operation lever 65 is screwed into the.

By rotating the stopper 66 to move it in the axial direction, the stopper 66 comes into contact with the adapter 67 connected to the rear end 52b of the sleeve 52 at a predetermined position. In the underwater granulation apparatus 1 described above, when the cutter shaft 12 is rotated by the cutter driving device 5, the cutter knife 1
1 rotates at high speed, the molten resin discharged from the nozzle 6 of the die 3 is cut into particles by each cutter knife 11,
The cut pellets are solidified by the cooling water supplied from the cooling water inlet 8 into the water chamber 4, and are sent together with this cooling water from the cooling water outlet 9 to a processing unit (not shown) and dried to be manufactured.

When replacing or cleaning the die 3,
It is necessary to remove or attach the water chamber 4 to the die 3. A method of detecting the tightening pressure by the piezoelectric element 13 when the water chamber 4 is attached will be described. First, the O-ring 14 arranged on the attachment surface of the water chamber 4 that comes into contact with the die 3.
A plurality of piezoelectric elements 13 are embedded outside the. Next, the water chamber 4 is fastened to the die 3 with bolts 7 or the like.
At this time, the surface pressure is detected by each piezoelectric element 13 to determine whether or not the specified tightening pressure is generated. In addition, if the surface pressure detected by each piezoelectric element 13 becomes non-uniform or drops below a specified value for some reason during operation, it is determined to be abnormal, and the underwater granulator 1 is stopped manually or automatically. To do. The O-ring 14 prevents the hot water in the water chamber 4 from leaking and protects the piezoelectric element 13 from the hot water.

Although the water chamber 4 is detachably fixed to the die 3 by the bolt 7 in the above-mentioned embodiment, it may be fixed to the cylinder head 2. Also, instead of manually tightening the bolts,
A water chamber tightening mechanism utilizing hydraulic pressure or spring pressure can be similarly adopted.

[0022]

Since the present invention is configured as described above, the following effects can be obtained. In other words, the tightening pressure of the water chamber can be set to the specified value and uniform, so that the leakage of warm water from the tightening surface can be prevented, the shape of the cut pellets can be made uniform, and the life of the cutter knife can be extended. can do.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an underwater granulating apparatus according to the present invention.

FIG. 2 is an enlarged view of a main part of FIG.

FIG. 3 is a configuration diagram of a main part of a conventional underwater granulation device.

[Explanation of symbols]

 1 Underwater granulator 2 Cylinder head 2a Ring-shaped resin passage 3 Die 3a Die surface 5 Cutter drive device 6 Nozzle 7 Bolt 11 Cutter knife 12 Cutter drive shaft 13 Piezoelectric element 14 O-ring

Claims (2)

[Claims] 1. A die (3) for a water chamber (4)
An underwater granulation device, wherein a plurality of piezoelectric elements (13) for detecting a tightening surface pressure are embedded in the circumferential direction of the side mounting surface. 2. The underwater granulator according to claim 1, wherein an O-ring (14) is provided inside the piezoelectric element (13).