JPH0586885B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a resin granulator that pelletizes a resin material, and in particular, a resin granulator that pelletizes a resin material by cutting the molten resin continuously extruded from a die into small pieces using a rotating cutter knife. This invention relates to a resin granulator that processes resin into granules.

(Prior Art) Generally, synthetic resin materials are transported after kneading raw materials and processing into pellets. A granulator that pelletizes resin material in this way continuously extrudes molten resin into water from a nozzle of a die, and cuts the string-shaped molten resin into small pieces with a cutter knife that is rotated along the die surface. In many cases, an underwater cut method is used in which the material is processed into granules. In that case,
The cutter knife is radially attached to a cutter holder, and the cutter holder is rotationally driven by a cutter drive device.

By the way, in such a granulator, the molten resin may flow out of the nozzle and drip along the die surface before granulation is started. for that,
At that time, when the cutter knife is located close to the die surface, the molten resin adheres to the cutter knife and solidifies. Therefore, it is desirable to keep the cutter knife relatively far away from the die surface before starting granulation. Furthermore, in order to facilitate operations such as cleaning and replacing the cutter knife or die, it is required that the cutter knife be able to be moved further back from the die surface.

On the other hand, the size of the gap between the cutter knife and the die has a large effect on the shape of the pellets obtained and the granulation efficiency. Therefore, it has become necessary to be able to finely adjust the clearance. Such fine adjustments are difficult to perform with a mechanism that moves the katsuta knife over a large distance.

For this reason, conventionally, for example,
As shown in Publication No. 509, an air cylinder is provided at the rear end of the cutter drive device, and a fine adjustment mechanism is provided in the middle part, and the air cylinder moves the cutter knife largely relative to the die to make fine adjustments. A mechanism has been proposed in which the gap between the katsuta knife and the die is finely adjusted. In this granulator, a cutter holder and a cutter drive shaft that transmits rotational force to the cutter holder are integrally constructed, and the whole is moved in the axial direction by an air cylinder or a fine adjustment mechanism.

(Problem to be solved by the invention) However, recently, even in this type of granulator, there has been a demand for larger capacity in order to rationalize productivity, and the outer diameter of dies and cutters has become larger. This is becoming more and more common. For this reason, cutter holders and cutter drive shafts have also become larger and heavier. In that case, if you try to move the cutter holder and the cutter drive shaft as one unit as described above, it will be necessary to use an extremely large capacity moving mechanism, especially an air cylinder that moves them, and the entire device will need to be moved. becomes extremely expensive. Moreover, it is necessary to support the cutter drive shaft in a way that allows both large axial movement and rotation, which makes the support and drive mechanism complicated, making it difficult to maintain high accuracy. Become.

Furthermore, in the case of low-viscosity resin, good cutting may not be possible unless the cutter knife is pressed against the die surface with a predetermined surface pressure. However, with the above-mentioned one, the cutter knife cannot be brought into pressure contact with the die surface.

As shown in Japanese Utility Model Publication No. 51-49660, a cutter knife that can be brought into pressure contact with the die surface has a cutter holder and a cutter drive shaft that are separate, and can be slid together in the axial direction. There is a type in which a spring is provided between which the cutter holder is fitted and connected, and which presses and urges the cutter holder toward the die. However, in such a device, the pressing force is obtained only by the characteristics of the spring, and in order to adjust the pressing force, it is necessary to replace the spring. Moreover, since the cutter knife has an inclination angle with respect to its rotational surface and generates thrust in the axial direction when rotating underwater, the pressing force varies depending on the rotational speed.

The present invention has been made in view of these problems, and its purpose is to be able to sufficiently separate the cutter knife from the die surface without significantly moving the cutter drive shaft, and to keep the cutter knife away from the die surface. It is an object of the present invention to provide a cutter position adjusting device that can press the cutter into contact with the cutter and adjust the pressing force even during operation.

(Means for Solving the Problem) In order to achieve this object, in the present invention, the cutter holder and the cutter drive shaft are fitted to each other so that rotational force is transmitted but they are slidable in the axial direction. A sealed chamber is formed between the cutter holder and the end face of the cutter drive shaft.
Pressure fluid is introduced into the sealed chamber from the outside through a flow path provided in the cutter drive shaft. Further, a spring is provided between the cutter holder and the cutter drive shaft to bias the cutter holder in a direction away from the die surface.

(Function) With this configuration, when pressure fluid is introduced into the sealed chamber between the cutter holder and the end face of the cutter drive shaft, the cutter holder moves away from the end face of the cutter drive shaft due to the pressure. ,
The cutter knife is pressed against the die surface. The pressing force can be adjusted by the pressure of the fluid introduced into the sealed chamber.

Further, when the pressure inside the sealed chamber is lowered, the cutter holder is moved back by the biasing force of the spring, and the cutter knife is separated from the die surface. In this case, if the pressure in the sealed chamber is set to zero, the cutter holder will retreat until it comes into contact with the end face of the cutter drive shaft, so the cutter knife will be sufficiently separated from the die surface.

(Example) Hereinafter, an example of the present invention will be described using the drawings.

The figures show an embodiment of the cutter position adjusting device according to the present invention, and FIG. 1 is a longitudinal sectional view of the cutter device portion of a resin granulator equipped with the cutter position adjusting device. It is an enlarged longitudinal cross-sectional view of the main part.

As is clear from FIG. 1, this granulator 1 is
A manifold 2 that distributes the molten resin extruded from an extruder (not shown) in the circumferential direction, and a die 3 that is attached in close contact with the manifold 2.
, a cutter case 4 attached to the front side of the die 3, and a cutter 5 provided inside the cutter case 4.

The die 3 is disk-shaped, and a ring-shaped area surrounding the center thereof is provided with a large number of nozzles 6, 6, . . . that penetrate in the axial direction. One end of the nozzle 6 is a ring-shaped resin passage 2a of the manifold 2.
The other end is opened into the cutter case 4.

The cutter case 4 is removably fixed to the manifold 2 by bolts 7, and is liquid-tightly coupled to the surface of the die 3. The cutter case 4 is provided with a hot water inlet 8 and a hot water outlet 9, so that the cutter case 4 is always filled with hot water.

The cutter 5 has a plurality of cutter knives 11, 1 on the outer periphery of the end face facing the die 3 of the cutter holder 10.
1 are fixedly supported in a radial manner, and the cutter knife 11 is positioned opposite to the die surface 3a of the die 3, that is, the surface of the ring-shaped area where the nozzles 6, 6... are provided. . Rotational force is transmitted to the cutter holder 10 by a cutter drive shaft 12 arranged on its central axis.

The cutter drive shaft 12 has a cylindrical casing 13
It is rotatably supported via bearings 14, 14, and is supported so as not to be relatively movable in the axial direction. And the casing 13
is supported by a cutter housing 15 fixed to the back side of the cutter case 4 so as to be freely slidable in the axial direction. Therefore, the cutter drive shaft 12
is movable in the axial direction together with the casing 13. A fine adjustment mechanism 19 consisting of a worm 16, a worm wheel 17, and an adjustment screw 18 is provided between the housing 15 and the casing 13, and the rotation of the worm 16 causes the casing 13 to move minutely in the axial direction. It is becoming more and more like this. This fine adjustment mechanism 19 is similar to the conventional one shown in, for example, Japanese Utility Model Publication No. 55-32727, and therefore detailed explanation will be omitted. In addition, between the rear end of the casing 13 (the right end in FIG. 1) and the housing 15, the casing 13 and the cutter drive shaft 12 are pressed toward the die 3 side, and the gap between the bearing 14 and the The cutter drive shaft 12 due to play in the screw of the adjustment mechanism 19, etc.
A compression spring 20 is provided to keep the axial play constant.

The proximal end of the cutter drive shaft 12 is connected via a coupling ring 21 that allows minute movement in the axial direction.
It is connected to an output shaft 22 of a rotating machine (not shown) such as a motor.

The proximal end of the cutter drive shaft 12 is sealed with a housing portion 15a surrounding the proximal end by a pair of front and rear seal members 23, 23, and an oil reservoir 24 is formed therebetween. The oil reservoir 24 communicates with an oil chamber 27 on the small-diameter piston 26 side of the pressure intensifier 25 provided outside the housing 15. And the pressure intensifier 25
High pressure air is introduced into the pressure chamber 29 on the large diameter piston 28 side from a pressure air source (not shown) via a switching valve 30, a pressure reducing valve 31, and an air valve 32. The switching valve 30 opens the pressure chamber 29 of the pressure intensifier 25 to the atmosphere in the illustrated position;
When switched to the left position, the pressure chamber 29 and the pressure reducing valve 31 are electrically connected. Further, the pressure reducing valve 31 is capable of arbitrarily adjusting the pressure of the air passing therethrough.

On the other hand, an oil hole 33 is formed at the base end of the cutter drive shaft 12 and opens into the oil reservoir 24 around the base end. Furthermore, an oil passage 34 is formed in the cutter drive shaft 12, passing through its center from its front end surface, that is, the end surface on the die 3 side, to the oil hole 33 at the base end.

As shown in FIG. 2, the cutter holder 1
0 has a substantially conical cylindrical shape, and the tip of the cutter drive shaft 12 is slidably fitted inside the cutter holder 10. An O-ring 35 is provided between the inner peripheral surface of the cutter holder 10 and the outer peripheral surface of the cutter drive shaft 12. Furthermore, a blind cover 37 is attached to the end surface of the cutter holder 10 on the die 3 side via a gasket 36.
In this way, the cutter holder 10 and the cutter drive shaft 12
An oil-tight sealed chamber 38 is formed between the distal end surface of the tube and the tip surface of the tube. Pressure oil is introduced into the sealed chamber 38 through an oil passage 34 formed in the cutter drive shaft 12.

A torque transmission disk 40 having an involute spline 39 formed on its outer peripheral surface is fixed to the tip surface of the cutter drive shaft 12 . Furthermore, a torque transmission ring 42 having an involute spline 41 formed on its inner peripheral surface is fixed inside the cutter holder 10 . Therefore, by engaging these splines 39 and 41, the rotational force from the cutter drive shaft 12 is transmitted to the cutter holder 10, and the cutter holder 10 can be slidably moved relative to the cutter drive shaft 12. It is gaining support.

A compression spring 43 is disposed between the cutter holder 10 and a torque transmission disk 40 fixed to the distal end surface of the cutter drive shaft 12 . Therefore, the cutter holder 10 is always pressed backward, that is, in a direction away from the die 3.

Next, the operation of the cutter position adjusting device configured as described above will be explained.

When cleaning the die 3 or replacing the cutter knife 11, the cutter housing 15 is mounted on the cart 44 as shown by the imaginary line in FIG. 1, and the cutter case 4 and the die 3 are connected. After removing the bolts 7, the entire cutter device consisting of the cutter case 4 and the housing 15 is separated from the die 3 side by moving the cart 44.
In this way, a sufficient working space can be secured between the die 3 and the cutter 5, so that operations such as cleaning and replacement can be easily performed.

After the work is completed, the cutter case 4 is brought into close contact with the die 3 and fixed by reversing the procedure. Then, the cutter position is adjusted while the extruder remains stopped.

When making this position adjustment, first, the fine adjustment mechanism 1
9 to move the cutter drive shaft 12 back as much as possible. Next, while opening the air valve 32,
Switch the switching valve 30 to the left position. Then, the air whose pressure has been adjusted by the pressure reducing valve 31 is transferred to the pressure intensifier 25.
is introduced into the pressure chamber 29 of the pressure intensifier 25 and the oil chamber 27 of the pressure intensifier 25.
The pressure-increased hydraulic oil is sent to an oil reservoir 24 around the base end of the cutter drive shaft 12. The high-pressure hydraulic oil then flows into the closed chamber 38 on the tip side of the cutter drive shaft 12 through the oil hole 33 and oil passage 34 formed in the cutter drive shaft 12. As a result, the cutter holder 10
moves forward toward the die 3 side, and the katsuta knife 1
1 approaches the die surface 3a.

When the cutter holder 10 moves forward through the entire stroke with respect to the cutter drive shaft 12, as shown in FIG. Further advances are regulated. Therefore, in this state, the fine adjustment mechanism 19 is operated to move the cutter 5 slightly forward together with the cutter drive shaft 12 and the casing 13 to adjust the gap between the cutter knife 11 and the die surface 3a. When pressing the cutter knife 11 against the die surface 3a, the cutter knife 1
1 is brought into close contact with the die surface 3a, and the pressure inside the sealed chamber 38 is further adjusted by the pressure reducing valve 31.

When the position adjustment of the cutter 5 is completed in this way, the switching valve 30 is switched to the illustrated position. Then, the pressure chamber 29 of the pressure intensifier 25 is opened to the atmosphere, so the pistons 26 and 28 of the pressure intensifier 25 become free, and the pressure in the sealed chamber 38 decreases. The cutter holder 10 has a compression spring 43
Due to the urging force of the blind cover 37, the cutter drive shaft 1
2 until it comes into contact with the torque transmission disk 40 on the front end surface. As a result, as shown in FIG. 1, the cutter knife 11 is sufficiently separated from the die surface 3a.

When performing granulation, the switching valve 30 is switched to the left position again to supply high pressure air to the pressure chamber 29 of the pressure intensifier 25. Accordingly, Katsutaknife 11
moves forward to the originally set position. Therefore, while operating the extruder, the cutter drive shaft 1 is connected to the cutter drive shaft 1 via the coupling ring 21 by a rotating machine such as a motor.
2 to rotate. Then, the rotational force is transmitted to the cutter holder 10 via the splines 39 and 41, and the cutter knife 11 rotates along the die surface 3a. Therefore, the molten resin continuously extruded from the extruder through the nozzles 6, 6, . The thus processed resin pellets are solidified in the hot water inside the cutter case 4, and are discharged from the hot water outlet 9 together with the hot water.

When interrupting granulation, the rotation of the cutter 5 is stopped and the switching valve 30 is switched to the illustrated position. Then, as described above, the cutter holder 10 retreats,
The cutter knife 11 is sufficiently separated from the die surface 3a. Therefore, even if the molten resin flows out from the nozzle 6 and drips along the die 3 at this time, the molten resin will not adhere to the cutter knife 11.

In this way, according to this cutter position adjustment device, the cutter knife 11 can be switched between the operating position and the rest position only by operating the switching valve 30. Further, by adjusting the pressure inside the sealed chamber 38, the pressing force of the cutter knife 11 against the die surface 3a can be adjusted.Moreover, the pressure can be adjusted by a pressure reducing valve 31 provided outside the cutter device. Therefore, the pressing force can be adjusted to the optimum value even during operation.

Furthermore, since hydraulic oil is used as a pressure medium to move the cutter holder 10 relative to the cutter drive shaft 12, it is not only easy to ensure sealing performance, but also the hydraulic oil is used to prevent sliding parts, etc. It can have a lubrication function and can perform smooth operation. Moreover, since the splines 39 and 41 that transmit the rotational force from the cutter drive shaft 12 to the cutter holder 10 are arranged in the sealed chamber 38, foreign objects are not caught, and sliding in the axial direction becomes smoother. Become.

By separating the cutter case 4 from the die 3 and performing operations such as cleaning the die 3 and replacing the cutter knife 11, there is no need to move the cutter drive shaft 12 significantly in the axial direction, and only small movements are required. Since the cutter can be held in place, the cutter drive mechanism and support mechanism can be simplified.

In addition, in the above embodiment, the cutter holder 1
0, the tip of the cutter drive shaft 12 is formed into a large-diameter cylindrical shape, and the shaft of the cutter holder 10 is fitted into the inside of the cutter drive shaft 12. It is also possible to do so.

In addition, in the above embodiment, the cutter holder 1
Although the splines 39 and 41 are used as a means for connecting the cutter drive shaft 12 to the cutter drive shaft 12 so as to be able to transmit rotational force and to be slidable in the axial direction, it is also possible to use sliding keys, polygons, etc. as the splines 39 and 41.

(Effects of the Invention) As is clear from the above description, according to the present invention, a sealed chamber is formed between the cutter holder and the end face of the cutter drive shaft, and the cutter holder is cut by the pressure fluid introduced into the sealed chamber. Since the cutter knife is moved in the axial direction relative to the drive shaft, the cutter knife can be sufficiently separated from the die surface without moving the cutter drive shaft, and the resin dripping from the die can be removed when the granulator is not operating. can be prevented from adhering to the katsuta knife. Therefore, the support structure of the cutter drive shaft or the structure of the power transmission mechanism can be simplified, making it possible to reduce the weight and size of the entire granulator and the cost.

Further, since the cutter knife can be pressed against the die surface by the pressure of the fluid introduced into the sealed chamber from the outside, even low-viscosity resin can be reliably cut. Moreover, the pressing force can be adjusted even during operation.
Even if the rotation speed etc. fluctuate during operation, it can be maintained in an optimal state.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of the cutter position adjusting device according to the present invention, and FIG. FIG. 1...Resin granulator, 3...Dice, 3a...Dice surface, 4...Katsuta case, 5...Katsuta, 1
0...Katsuta holder, 11...Katsuta knife, 1
2...Cut drive shaft, 15...Cut housing, 19...Fine adjustment mechanism, 34...Oil passage (flow path),
35... O-ring, 37... Blind lid, 38... Sealed chamber, 39, 41... Spline, 43... Spring.

Claims (1)

[Scope of Claims] 1. A cutter holder that fixedly supports a cutter knife that is rotatably driven along a die surface, and a cutter drive shaft that transmits rotational force to the cutter holder, and molten resin extruded from the die is directed to the cutter knife. In a resin granulator that processes the resin into granules by cutting; The cutter holder and the cutter drive shaft are fitted and connected to each other, so that the cutter holder is slidable in the axial direction with respect to the cutter drive shaft. At the same time, a sealed chamber is formed between the cutter holder and the end face of the cutter drive shaft, and a passage for introducing pressure fluid from the outside into the sealed chamber is provided on the cutter drive shaft, and the cutter drive shaft is connected to the cutter holder and the cutter drive shaft. A cutter position adjustment device for a resin granulator, comprising a spring biased in a direction away from the cutter holder and the die surface between the cutter holder and the die surface.