JP3817048B2 - Cutter hub holder - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a die plate for an underwater pelletizer that includes a spring loaded blade holder that is motively coupled to a drive shaft and is axially pressed toward the die plate with a variably controlled pressure. The present invention relates to a cutter hub holder for a working blade. The drive connection of the cutter hub holder between the drive shaft and the blade holder includes a quick connection and a release drive coupling.
[0002]
[Prior art]
The underwater pelletizer is disclosed in the following US patent specifications. That is, U.S. Pat. Nos. 3,196,487, 3,317,957, 4,123,207, 4,179,255, 4,500,271, 4,529,370, 4,614 307, 4,782,276, 5,059,103, 5,110,523, 5,190,768, 5,435,713, 5,527,176.
[0003]
The above patents are: (a) a device for manually controlling the displacement of the cutter assembly to compensate for blade wear and maintain accurate blade pressure on the die; (b) between the cutter assembly and the die. A device that automatically propels the blade by a stepper motor activated by a sensor that detects blade wear by detecting relative distance, (c) a spring that applies pressure to the knife holder assembly, and (d) An electrical circuit for hydraulic control is disclosed for automatically displacing the drive shaft to control blade pressure on the die. However, the above-mentioned patents describe the optimum of a structure that provides variable fluid pressure to pistons and cylinders incorporated in the drive shaft and a cutter blade that is directed to the die surface by applying a force to a spring that displaces the cutter hub. Does not disclose a mediating member that maintains the correct pressure. Furthermore, the above-mentioned patents do not disclose an insertion coupling cutter hub attachment to the drive shaft of an underwater pelletizer that allows relative axial movement.
[0004]
In a cutter hub holder of the type generally disclosed in US Pat. No. 5,059,103 issued Oct. 22, 1991, the wear of the cutter blade is compensated for permanent contact with the die plate of the cutter blade. In order to ensure contact, the blade holder is pressed against the die plate by a spring. In known cutter hub holders, the spring pressure is selected to meet the needs during the pelletization process. Therefore, this pressure is always set to the highest pressure required during operation, even if a low spring pressure is sufficient. The higher the spring pressure acting on the blade holder, the greater the wear on the blade and die plate.
[0005]
Devices utilizing blade holders and manual blade adjustment methods require careful operator attention during operation of the device. As the blade wears, the pellet quality decreases and the operator must constantly monitor the process and adjust the blade. The amount of adjustment that is made depends on the operator. Often tends to be over-adjusted, leading to faster blade and die plate wear. The pressure can be set as light or heavy as required so that the operator can move one setting without further adjustments being required. A compression spring is used in the cutter head to ensure steady contact between the die and the cutter.
[0006]
Devices that use only compression springs to adjust the blade do not offer the freedom to change the pressure of the cutter blade against the die surface. The spring of the desired tension must be incorporated into the cutter head during setup. Once the device is activated, the spring pull cannot be changed even if it is heavier or lighter than the required pull. If the spring is changed, the entire cutting process must be stopped. As proposed by the present invention, with controllable fluid pressure, the pressure of the blade against the die can be adjusted to the same lightness or weight as required by a simple air pressure regulator.
[0007]
Devices that utilize hydraulic pressure to adjust the blades require the use of a dedicated hydraulic unit to control the pressure of the blade against the die. In order to control the adjustment of the blade, the use of this method involves more elements mechanically and electrically. In order to accommodate the hydraulic unit, equipment must be created on or around the device, and a fluid design incorporating an air line is required. In environments that incorporate this type of equipment, compressed air lines are generally available. In addition, for the drive motor on the hydraulic unit, a designated control circuit is required on the hydraulically adjusted unit. Furthermore, when using the hydraulic method, special care is required so that oil does not leak into the treated water even if there is a seal defect.
[0008]
[Problems to be solved by the invention]
The object of the present invention is to wear the blade and die plate while maintaining full control of all operating conditions by pressing the holder against the die plate with a controlled variable pressure, preferably using fluid pressure. It is an object of the present invention to provide a cutter hub holder for an underwater pelletizer that can reduce the above.
[0009]
[Means for Solving the Problems]
As used herein, the cutter hub holder of the present invention, the components for interconnecting the blade holder cutter blade is mounted, electric drive which rotates with the cutter blade is mounted on the blade holder A drive shaft of the motor.
[0010]
According to the present invention, the blade holder on which the blade is placed is pressed against the die plate with a variable pressure by the cutter hub holder. Therefore, the optimum pressure can always be used according to the operating state. This means that during normal operation, pelletization can occur at lower pressures, and the blade pressure can be increased higher for a short period of time in response to changes that occur during operation.
[0011]
Such a high pressure of the blade holder against the active die plate may be required when the polymer layer is formed on the cutting surface of the blade, for example as a result of smearing. Such a layer will degrade the cutting performance and the quality of the cut pellets. Thus, the plant must be shut down to remove the polymer, resulting in substantial disruptions and interruptions during operation. The cutter hub holder according to the present invention allows removal of the polymer layer formed on the cutting surface by increasing the pressure of the blade against the die plate only for a short time, and the cutting surface is cleaned. Thus, the product can remain under mild and lower blade pressure.
[0012]
In another example, it is necessary to begin pelletizing a very low viscosity material at the high pressure of the blade against the cutting surface. However, after the extrusion fixing and pelletizing process, the pressure of the blade against the cutting surface is reduced and pelletization can be performed at a lower pressure that would minimize blade and die plate wear.
[0013]
With the cutter hub holder of the present invention, the pressure of the holder and hence the pressure of the blade against the die plate is adapted to the current operating requirements, so that blade and cutting surface and / or die plate wear is minimized to the necessary amount. Can be
[0014]
According to a preferred embodiment of the invention, the holder can be hydrostatically pressurized in the direction of the die plate. Since the fluid pressure is easily controllable, the control facility can easily and quickly adjust the currently required pressure.
[0015]
Further in accordance with the present invention, a drive shaft such as an electric motor is provided with an axial hole. The axial bore has an end indicating that the cutter hub holder extends to the cylinder bore and an end connected to the compressed air source by a rotary transmission leadthrough. The cylinder hole includes a piston and a piston rod, and the piston rod is connected to the holder or acts directly on the holder.
[0016]
The cutter hub holder is preferably configured as a tubular headpiece connected to a shaft that is axially shiftable but not rotatable, or a medium connected to the shaft. The headpiece has a through hole that is stepped by at least two annular shoulders or a pocket-like hole that is stepped by at least one annular shoulder. Furthermore, the pressure spring is inserted between the annular shoulder portion outside the through-hole or the bottom portion of the pocket-shaped hole and the piston rod. The pressure applied to this pressure spring can be varied by changing the position of the piston rod, and thus becomes suitable for the currently required pressure of the blade against the die plate.
[0017]
In order to allow rapid replacement of blades and blade holders without long interruptions in operation, the present invention provides a medium in which the head piece of the cutter hub holder is connected to the shaft or shaft in a power-conducting and separable manner To each other by a coupling coupling. The plug-in coupling is preferably configured to be associated with a pressure spring. The pressure spring can maintain the plug-in coupling in the locked position.
[0018]
The plug-in coupling consists of two parallel grooves in the shaft. One groove is open at the end of the shaft. The other groove terminates toward the inside of the end of the shaft and the grooves are connected to each other by a radial circumferential groove at each inner end. The headpiece includes a key that projects into the hole. The key engages the shaft and is shiftable within the shaft groove. The headpiece can be pressed axially on the shaft until the key reaches the inner end of the open end groove and then rotates in another groove which acts to lock the headpiece against the shaft So that axial movement of the headpiece relative to the shaft is still possible. Preferably, the spring pressure is selected to roughly correspond, or is equal to or higher than the maximum pressure of the blade against the die plate. In order to remove the head piece, it is only necessary to press the head piece inward in the same axial direction against the spring and to be reversed with respect to the drive rotation direction. The key can then be pulled out of the open end groove of the plug-in coupling. It is preferable that the key and the groove attaching device are provided in pairs in regions facing each other in the diameter direction of the shaft and the head piece.
[0019]
[Preferred embodiment]
Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings, but the present invention is not limited thereto. Other embodiments may be used and can be implemented in various ways. Furthermore, in describing preferred embodiments, certain terminology is used only for the sake of clarity. It is to be understood that each specific term includes all technical equivalents that act in a similar manner to accomplish a similar purpose. Moreover, in order to show the same member in a drawing, the same reference number was attached | subjected.
[0020]
The cutter hub holder of the submerged pelletizer constructed in substantially the same manner as described in US Pat. No. 5,069,103 will be described as the cutter hub holder of the present invention. The cutter hub holder of the present invention is generally indicated by reference numeral 30 and differs from the aforementioned US patents in the features described more fully below.
[0021]
The motor shaft 1 of the electric drive motor 2 has a central hole 3 at the center. At the power extraction end of the motor shaft 1, the center hole 3 extends to the cylinder hole 4 via an annular shoulder 4A. The cylinder hole 4 includes a fluid pressure piston 5 connected to a piston rod 6.
[0022]
The power extraction end of the motor shaft 1 includes a tubular medium 7. The rear end of the tubular medium 7 extends to the sleeve 8 that overlaps the motor shaft 1 and is connected to the motor shaft 1. The mediator 7 comprises a front cylindrical part 9 having a smaller diameter than the sleeve 8. The cylindrical portion 9 includes a through hole 9A having a smaller diameter. The through hole 9 </ b> A is substantially aligned with the center hole 3 and the cylinder hole 4 and receives the sliding member 10 attached to the piston rod 6.
[0023]
As shown in FIG. 4, the cylindrical portion 9 of the mediator 7 includes an outer groove that forms a part of the insertion coupling, and includes an open end groove 12 and a parallel groove 13. The parallel groove 13 is closed at the outer end. The inner ends of the grooves 12 and 13 are connected to each other by a radial circumferential groove 14. The groove 12 is offset with respect to the groove 13 with respect to the rotational direction of the shaft, as indicated by the arrow 15 in FIG. The grooves 12 and 13 are provided by machining on the surface of the cylindrical portion 9 substantially parallel to the axis of the cylindrical portion 9.
[0024]
The cylindrical portion 9 of the medium 7 holds the head piece 16. As shown in FIG. 2, the head piece 16 forms a rotationally symmetric portion including a blind hole 16 </ b> A having an annular shoulder portion 17 at an inner end portion thereof. The headpiece 16 receives the cylindrical part 9 in a nested manner. The pressure spring 18 is inserted into a blind hole 16 </ b> A between the slide piece 10 and a substantially central recess 17 </ b> A that forms the shoulder 17.
[0025]
The blind hole 16 </ b> A of the headpiece 16 includes a diametrically opposed key 20. The key 20 projects radially into the blind hole 16A and is held in place by welding or the like. The front end portion of the head piece 16 includes an external thread groove 21. A blade holder 22 is screwed onto the external thread groove 21 as shown in FIG.
[0026]
In order to place the headpiece 16 on the cylindrical part 9, the key 20 is inserted into the opposite insertion or open end groove 12 and pushed inward to the bottom of these grooves. Thus, the pressure spring 18 is compressed and the key 20 can be locked into the groove 13 by shifting radially through the circumferential groove 14 in an arcuate manner. Furthermore, the key 20 preferably has a shorter length than the groove 13 that allows the headpiece 16 to move in the axial direction, as indicated by an arrow 31 in FIG. The axial movement of the head piece 16 against the spring 18 moves the blade holder 22 and the cutter blade 23 toward the die surface 24 as shown in FIG.
[0027]
The outer end 25 of the motor shaft 1 is provided with a fixed roller transmission leadthrough 26. At the fixed rotary transmission leadthrough 26, the compressed air line is connected through the pressure regulating valve to detect and control the fluid pressure entering the central hole 3 in the motor shaft 1. The flange 27 mounted on the motor housing, which is basically known from US Pat. No. 5,059,103, functions as a water box fitting with a water flow line and a water return line and a die plate 28. The cutter blade 23 of the blade holder 22 wipes the water across the die plate 28.
[0028]
The quick connection and release capability of the blade holder 22, the headpiece 16 and the mediator 17 is made possible by the insertion grooves 12, 14 and 13 that cooperate with the key 20. When the components are in an assembled relationship and the blade 27 is separated from the water box and the motor housing and associated structure are moved away from the die surface and then the blade holder 22 is desired to be released quickly, the blade An axial force is applied on the holder 22 to compress the spring 18 enough to align the key 20 with the groove 14 and to rotate the blade holder 22 counterclockwise as indicated by arrow 15 in FIG. It's okay. As soon as the key 20 is aligned with the groove 12, the blade holder 22 with the head piece 16 and the mediator 7 is movable in the axial direction of the cylindrical portion 9 until the key 20 exits the groove 12. This quick release capability allows for quick replacement of the blade holder and blades without interruption of the long-term operation of the underwater pelletizer.
[0029]
To assemble the blade holder 22, headpiece 16 and mediator 7 on the cylindrical portion 9, the key 20 is aligned with the open end of the groove 12 and the spring 18 is compressed until the key 20 is aligned with the groove 14. Thus, the assembly need only be moved axially inward. Next, the blade holder 22, the head piece 16 and the medium 7 are partially rotated in the clockwise direction until the key 20 moves through the groove 14 to the alignment position with the groove 13. At this time, the inward force is released from the blade holder 22 and the spring 18 maintains the key 20 in the groove 13. However, the key 20 is still axially movable in the groove 13 and is determined by the force of the spring 18 and the fluid pressure exerted against the piston 5, as determined by the blade holder 22 and The cutter blade 23 is pressed against the die surface 24. Together with this configuration, the quick connection and release capability of the cutter hub holder 30 allows the blade holder 22 to be quickly removed and replaced. Further, the displacement of the piston by the controlled fluid pressure gives the optimum spring pressure of the cutter blade 23 to the die surface 24 by moving the piston 5, the piston rod 6 and the sliding member 10 by controlling the fluid pressure. The elasticity of the spring 18 that can compress or release the spring will change the force pressing the cutter blade 23 against the die surface 24.
[0030]
As described above, the cutter hub holder 30 of the present invention includes these components that interconnect the blade holder 22 with the motor shaft 1. These components are the head piece 16, the spring 18, the sliding member 10, the medium 7, the piston rod 6, the piston 5, the cylinder hole 4 with the shoulder 4A, and the cylindrical portion 9 of the medium 7 and the head piece 16. Including plug-in coupling.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a cutter hub holder and associated drive assembly.
FIG. 2 is a cross-sectional view of a head piece.
FIG. 3 is an end view of the head piece.
FIG. 4 is a perspective view of a mediator portion of a shaft having a groove that forms a bayonet coupling.
[Explanation of symbols]
1: Motor shaft 2: Drive motor 3: Center hole 4: Cylinder hole 5: Piston 6: Piston rod 7: Medium 8: Sleeve 9: Cylindrical portion 10: Sliding members 12, 13, 14: Groove 16: Head Piece 17: annular shoulder 18: spring 20: key 22: blade holder 23: cutter blade 24: die surface 28: die plate 30: cutter hub holder

Claims (10)

A cutter hub holder ( 30 ) for a blade acting in conjunction with a die plate (28) of an underwater pelletizer,
A blade holder (22) connected in a power conductive manner to the drive shaft (1),
The blade holder (22) is pressed toward the die plate (28) in the axial direction by a spring (18) with variable control pressure, and fluid pressure is applied in the direction of the die plate (28). Being pressed,
The drive shaft (1) includes a shaft hole (3), one end of the shaft hole (3) adjacent to the holder includes a cylinder hole (4), and the other end of the shaft hole is a rotary transmission lead. The cylinder hole (4) is connected to a fluid pressure source by a through (26), and the piston (5) and the piston rod (6) act on the blade holder (22) via the spring (18). ) Is slidably received in the cutter hub holder. Cutter hub holder according to claim 1, characterized in that the drive shaft (1) is a shaft (1) of an electric motor (2). Cutter hub holder (1) according to claim 1, wherein the blade holder (22) is connected in a conductive manner with a vehicle (7) connected to the drive shaft (1). Is configured as
The mediator (7) includes a through hole (9A) extending to receive the piston rod (6), and the spring (18) is between the piston rod (6) and the headpiece (16). A cutter hub holder, wherein the head piece (16) is placed on the medium (7) so as to be movable in the axial direction. The cutter hub holder according to claim 3, wherein the head piece (16) is mounted on the medium (7) so as to be removable and movable in an axial direction, and the head piece (16) is placed on the medium. A cutter hub holder comprising an insertion coupling (20; 12-14) that is removably mounted on an object. 5. The cutter hub holder according to claim 4, wherein the insertion coupling (20; 12 to 14) includes a pair of parallel grooves (12, 13) in the medium (7), and one groove (12 ) Is open at the outer end, the other groove (13) is closed at the outer end, and the pair of grooves (12, 13) are radially connected to each other at the inner end. Connected by a circumferential groove (14),
The head piece (16) has at least one key (20) projecting radially in the hole (16A), the key (20) being in the groove (12-14) in the hole (16A). The cutter hub holder is capable of shifting the head piece (16) in the axial direction when the key (20) is engaged with the other (13) of the pair of grooves. 6. The cutter hub holder according to claim 5, wherein the medium (7) includes a pair of diametrically opposed grooves (12, 13), and the hole (16A) in the headpiece (16) Cutter hub holder comprising two keys (20). A blade cutter hub holder that acts on a die plate of an underwater pelletizer,
A blade holder (22) connected in a power conductive manner to the drive shaft (1),
The blade holder (22) is axially pressed toward the die plate (28) with variable control fluid pressure, and is pressed toward the die plate (28) by a spring (18). ,
The spring (18) is pressed by a variable control fluid pressure to apply a spring force to the blade holder (22), and the pressing force is applied to the die plate (28) via the blade holder (22). Is acting,
The drive shaft (1) comprises axial holes (3, 4) having one end connected to a fluid pressure source controlled by a pressure regulator, the axial holes (3, 4) being Piston (5) and piston rod that engage with the spring (18) that is slidable in the axial hole at opposite ends and that applies a variably controlled force to the blade holder (22) (6) The cutter hub holder characterized by including. Cutter hub holder according to claim 7, comprising a tubular headpiece (16) supporting the blade holder (22),
The tubular headpiece (16) is axially movable with respect to the drive shaft (1) and is rotatably driven by the drive shaft;
The spring (18) is positioned in a hole in the head piece (16), one end of the spring applies a force to the head piece, and the other end is the piston (5) and piston rod (6). Cutter hub holder characterized by being compressed or expanded by movement of 8. The cutter hub holder according to claim 7, wherein the drive shaft (1) and the blade holder (22) comprise a quick connect / release coupling (20; 12-14), the blade holder (22) being A cutter hub holder characterized in that it can be replaced quickly and easily. Cutter hub holder according to claim 9, wherein the quick connect / disconnect coupling (20; 12-14) is a plug-in coupling (12- 12) between the blade holder (22) and the drive shaft (1). 14) The cutter hub holder characterized by including.

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