CN113427663A

CN113427663A - Plastic underwater granulator

Info

Publication number: CN113427663A
Application number: CN202110781167.6A
Authority: CN
Inventors: 刘土法; 刘博韬; 王玲; 李祥伟
Original assignee: Nanjing Hone Machinery Electronics Co ltd
Current assignee: Nanjing Hone Machinery Electronics Co ltd
Priority date: 2021-07-10
Filing date: 2021-07-10
Publication date: 2021-09-24
Anticipated expiration: 2041-07-10
Also published as: CN113427663B

Abstract

The utility model relates to a plastics underwater granulator, relate to the field of plastic granules processing equipment, which comprises a frame, sliding connection has the slide in the frame, be equipped with the axle bed on the slide, the axle bed internal rotation is connected with the dabber, the one end of dabber is equipped with the spline, the cover is equipped with the key sleeve on the spline, the key sleeve tip is equipped with the cutter, be equipped with first solid fixed ring on the key sleeve, the axle bed lateral wall is equipped with the extension board that supplies the dabber to pass, the extension board lateral wall rotates through rotating the piece and is connected with the solid fixed ring of second, be connected with the spring between the solid fixed ring of second and first fixed ring, the one end that the cutter was kept away from to the axle bed is installed and is used for driving dabber pivoted driving motor, be equipped with the driving piece that is used for driving the slide removal in the frame, be equipped with the just right sealed cowling with the cutter in the sealed cowling, be equipped with the die head on the sealed cowling, outlet pipe and locking seal spare. The application has the effect of improving the particle forming quality.

Description

Plastic underwater granulator

Technical Field

The application relates to the field of plastic particle processing equipment, in particular to an underwater plastic granulator.

Background

For granulation of low-viscosity and high-elasticity polymer materials or granules with special requirements for granulation, an underwater pelletizer is generally used to cut molten rubber and plastic materials extruded through a die head into granules in flowing water, and for optimum cutting effect, a cutter of the underwater pelletizer needs to be in close contact with the die head surface.

In view of the above-mentioned related technologies, the inventor believes that the conventional cutter is in hard contact with the end face of the die head, which easily causes the cutter to be disturbed, thereby affecting the molding quality of the cut particles.

Disclosure of Invention

In order to improve granule shaping quality, this application provides a plastics pelleter under water.

The application provides a plastic underwater granulator adopts following technical scheme:

the utility model provides a plastics underwater granulator, includes the frame, sliding connection has the slide in the frame, be equipped with the axle bed on the slide, the axle bed internal rotation is connected with the dabber, the one end of dabber is equipped with the spline, the cover is equipped with the key sleeve on the spline, the key sleeve tip is equipped with the cutter, be equipped with first solid fixed ring on the key sleeve, the axle bed lateral wall is equipped with the extension board that supplies the dabber to pass, the extension board lateral wall rotates through rotating and is connected with the solid fixed ring of second, be connected with the spring between the solid fixed ring of second and first fixed ring, the one end that the cutter was kept away from to the axle bed is installed and is used for driving dabber pivoted driving motor, be equipped with the driving piece that is used for driving the slide removal in the frame, be equipped with the just right sealed cowling of cutter in the frame, be equipped with the die head in the sealed cowling, be equipped with inlet tube, outlet pipe and locking sealing member on the sealed cowling.

By adopting the technical scheme, when the material is cut into particles, an operator drives the sliding seat to move forward through the driving piece to drive the cutter to enter the sealing cover and abut against the die head, the sealing cover and the shaft seat are fixed and sealed through the locking sealing piece, then the water inlet pipe and the water outlet pipe are connected, the driving motor is started, the driving motor drives the mandrel to rotate, the mandrel drives the cutter to rotate, and the material strips extruded from the die head are cut; when the cutter and the die head are abutted, the spring is in a compressed state, and elastic thrust action is exerted on the cutter, so that the cutter is kept in an elastic fit state with the die head, the possibility of cutter disturbance or cutter abrasion overweight is reduced, and the particle forming quality is improved.

Optionally, the rotating member includes a center ring and an angle plate, the center ring is fixed to the support plate, an annular first groove is formed in one end, away from the support plate, of the center ring, a second groove is formed in the outer circumferential side wall of the center ring, the second groove is coaxially distributed, a plurality of first steel balls are embedded in the side wall of the second fixing ring, each first steel ball is abutted to the first groove, a plurality of angle plates are circumferentially distributed along the axis of the second fixing ring, each angle plate is connected to the side wall of the second fixing ring in a sliding mode along the radial direction of the second fixing ring, a second steel ball is embedded in one end, facing the axis of the second fixing ring, of each angle plate, each second steel ball is abutted to the second groove, and each angle plate is fixed through the limiting unit.

By adopting the technical scheme, when the key sleeve rotates, the spring drives the second fixing ring to rotate, and the second fixing ring drives the first steel ball and the second steel ball to respectively move along the first groove and the second groove, so that the second fixing ring is rotatably connected with the support plate, and the resistance on the second fixing ring is favorably reduced; an operator can remove the limiting unit to enable the angle plate to be far away from the center ring, so that the rotating piece can be detached flexibly and conveniently.

Optionally, the limiting unit includes a slider and a limit screw, the slider is connected to one side of the angle plate facing the second fixing ring, a sliding groove for sliding each slider is formed in the second fixing ring, the limit screw is connected to the angle plate in a threaded manner, and the end of the limit screw penetrates through the slider and abuts against the bottom of the sliding groove.

Through adopting above-mentioned technical scheme, stop screw supports tightly with the spout tank bottom, and the slider supports tightly with the spout cell wall under stop screw's drive for the position of slider is fixed.

Optionally, the driving part comprises a screw and a servo motor, the screw is rotatably connected to the rack, one end of the screw is in threaded connection with the sliding seat, the other end of the screw is in coaxial connection with a motor shaft of the servo motor through a coupler, and the servo motor is installed on the rack.

By adopting the technical scheme, the servo motor drives the screw rod to rotate, the screw rod drives the sliding seat to move, the transmission ratio is accurate, the position precision is high, and the control is convenient.

Optionally, two guide rods symmetrically distributed about the screw rod are arranged on the machine frame, and the two guide rods penetrate through the sliding seat.

Through adopting above-mentioned technical scheme, the guide bar has played the guide effect to the slide, utilizes the stability that improves the slide and remove.

Optionally, the locking seal spare includes buckler and adjusting collar, the buckler is the annular and fixes on the axle bed, the buckler external diameter is the same with the buckler external diameter and both openings relative distributions, the buckler open end is equipped with the intermediate ring of coaxial distribution, the parcel has first elastic sealing pad on the intermediate ring, the seal groove that supplies the intermediate ring embedding is seted up to the buckler open end, adjusting collar threaded connection is on the buckler, the inside second elastic sealing pad that is equipped with of adjusting collar, second elastic sealing pad is located the butt joint department of buckler and buckler.

Through adopting above-mentioned technical scheme, the intermediate ring drives first elastic sealing pad and inserts in the seal groove and first elastic sealing pad supports tightly with the seal groove cell wall, has realized that first sealing between sealed cowling and buckler, and second elastic sealing pad is stopped up the gap between sealed cowling and buckler, realizes that the second is sealed.

Optionally, a plurality of annular convex edges are arranged on the sealing cover, and a sinking groove matched with each convex edge is arranged on the inner side of the second elastic sealing gasket.

Through adopting above-mentioned technical scheme, the bead embedding sinks in the second elastic sealing gasket in the groove for the laminating route tortuous between the sealed cowling of second elastic sealing gasket does benefit to the sealed effect of reinforcing.

Optionally, the cutter includes blade disc and blade, be equipped with a plurality of sleeves that distribute along blade disc axis equidistance on the blade disc periphery, it has two clamp splices, two to peg graft in the sleeve the clamp splice passes through adjusting screw to be fixed, the blade is located between two clamp splices, and sets up the waist type groove that supplies the screw to pass on the blade, threaded connection has locking screw on the sleeve, locking screw tip is worn into in the sleeve and is supported tightly with the clamp splice.

Through adopting above-mentioned technical scheme, the rotatable clamp splice of operator comes the contained angle between adjustment blade and the die head, also can remove the blade and adjust its protrusion distance, has increased blade and die head cutting complex flexibility and blade to the effect of material strip cutting.

Optionally, locking screw and clamp splice one-to-one, two all set up on the clamp splice and supply locking screw male annular, the shaft hole of coaxial distribution is seted up to locking screw tip, it has first stem to peg graft in the shaft hole, the one end that shaft hole bottom was kept away from to first stem is fixed with the second stem, second stem tip is equipped with the cambered surface with annular matched with.

By adopting the technical scheme, the two locking screws respectively apply pressure to the two clamping blocks to force the two clamping blocks to clamp the blade mutually; the cambered surface increases the contact area between the second core column and the bottom of the annular groove, so that the force application uniformity of the clamping block is improved, and the possibility of slipping between the second core column and the clamping block is reduced.

Optionally, a shift lever is vertically arranged on the adjusting sleeve.

By adopting the technical scheme, the shifting rod facilitates the rotation of the adjusting sleeve by an operator, and time and labor are saved.

In summary, the present application includes at least one of the following beneficial technical effects:

1. the elastic matching of the cutter and the die head is realized, the possibility of cutter disturbance or cutter over-heavy abrasion is reduced, and the particle forming quality is improved;

2. the two seals between the sealing cover and the waterproof cover increase the sealing performance of the underwater granulator; the angle and the extending distance of the cutter can be freely adjusted, so that the cutting matching flexibility of the blade and the die head and the cutting effect of the blade on the material strips are improved.

Drawings

Fig. 1 is a schematic overall structure diagram of an embodiment of the present application.

Fig. 2 is a schematic structural diagram for embodying the shaft seat and the mandrel according to the embodiment of the present application.

Fig. 3 is an enlarged view of a in fig. 2.

Fig. 4 is a schematic structural diagram for embodying the cutter according to the embodiment of the present application.

Fig. 5 is a schematic structural diagram for embodying the first core column and the second core column in the embodiment of the present application.

Description of reference numerals: 1. a frame; 11. a slide base; 12. a shaft seat; 13. a mandrel; 131. a spline; 14. a key sleeve; 141. a first retaining ring; 15. a support plate; 16. a second retaining ring; 17. a spring; 18. a drive motor; 2. a sealing cover; 21. a die head; 22. a water inlet pipe; 23. a water outlet pipe; 3. a rotating member; 31. a center ring; 311. a first groove; 312. a second groove; 32. a gusset; 33. a first steel ball; 34. a second steel ball; 35. a slider; 36. a limit screw; 37. a chute; 4. a drive member; 41. a screw; 42. a servo motor; 421. a coupling; 43. a guide bar; 5. locking the sealing element; 51. a waterproof cover; 52. an adjusting sleeve; 521. a second resilient gasket; 522. a deflector rod; 53. an intermediate ring; 531. a first resilient gasket; 54. a sealing groove; 55. a rib; 56. sinking a groove; 6. a cutter; 61. a cutter head; 62. a blade; 621. a waist-shaped groove; 63. a sleeve; 64. a clamping block; 641. an adjusting screw; 642. a ring groove; 65. locking the screw; 651. a shaft hole; 66. a first stem; 67. a second stem; 671. and (4) cambered surface.

Detailed Description

The present application is described in further detail below with reference to figures 1-5.

The embodiment of the application discloses a plastic underwater granulator. Referring to fig. 1 and 2, the underwater plastic granulator comprises a frame 1, a sealing cover 2 and a sliding base 11 which are relatively distributed are arranged on the frame 1, a die head 21 is arranged in the sealing cover 2, the die head 21 is connected with a discharge port of a die cylinder of an extruder, a hole for extruding a molten material in the extruder is formed in the die head 21, a water inlet pipe 22 and a water outlet pipe 23 which are symmetrically distributed in the vertical direction are arranged on the sealing cover 2, and a locking sealing element 5 is arranged on the sealing cover 2.

As shown in fig. 1, the sliding base 11 is horizontally disposed on the frame 1 and slidably connected along the length direction of the frame 1, two parallel guide rods 43 are disposed on the frame 1, the two guide rods 43 are both located below the sliding base 11, a guide cylinder for the two guide rods 43 to pass through is disposed on the bottom surface of the sliding base 11, and a driving member 4 for driving the sliding base 11 to move is disposed on the frame 1.

Referring to fig. 2 and 3, a shaft seat 12 is arranged on a sliding seat 11, a mandrel 13 is rotatably connected in the shaft seat 12, the mandrel 13 and a die head 21 are coaxially distributed, two ends of the mandrel 13 penetrate out of the shaft seat 12, a coaxially distributed spline 131 is arranged at one end of the mandrel 13 facing a sealing cover 2, the spline 131 and the mandrel 13 are integrally formed, a key sleeve 14 is sleeved on the spline 131, the inner side wall of the key sleeve 14 is matched with the spline 131 to limit relative rotation between the key sleeve and the spline 131, a cutter 6 is arranged at one end of the key sleeve 14 away from the spline 131, the cutter 6 is opposite to the sealing cover 2, a first fixing ring 141 is coaxially arranged on the key sleeve 14, a spring 17 is fixed at one side of the fixing ring away from the cutter 6, the spring 17 is sleeved outside the key sleeve 14, a second fixing ring 16 is fixed at one end of the spring 17 away from the first fixing ring 141, the second fixing ring 16 is sleeved outside the mandrel 13, a support plate 15 is arranged at one end of the shaft seat 12 facing the sealing cover 2, and the support plate 15 is vertically penetrated through the mandrel 13, the fulcrum plate 15 is opposite to the second fixed ring 16 and the second fixed ring 16 is rotatably connected to the side wall of the fulcrum plate 15 by the rotating member 3. A driving motor 18 is fixedly installed at one end of the shaft seat 12 far away from the cutter 6, and a motor shaft of the driving motor 18 is coaxially fixed with the mandrel 13 through an elastic coupling 421.

When cutting the grain, the operator drives the sliding seat 11 to advance through the driving piece 4, drives the cutter 6 to insert into the sealing cover 2 and abut against the end face of the die head 21, and then fixes and seals the end parts of the sealing cover 2 and the shaft seat 12 by using the locking sealing piece 5.

As shown in fig. 4, the cutter 6 comprises a cutter disc 61 and a blade 62, the cutter disc 61 is coaxially fixed with the key sleeve 14, a plurality of sleeves 63 are arranged on the outer circumferential wall of the cutter disc 61 and are circumferentially distributed at equal intervals along the axis of the cutter disc 61, and the axis of each sleeve 63 is perpendicular to the axis of the cutter disc 61; two clamping blocks 64 are inserted into each sleeve 63, the cross section of each clamping block 64 is semicircular, the axis of each clamping block 64 is parallel to the axis of the sleeve 63, the planes of the two clamping blocks 64 are opposite, the blade 62 is clamped between the two clamping blocks 64, the blade 62 is provided with two parallel waist-shaped grooves 621, the waist-shaped grooves 621 are perpendicular to the axes of the clamping blocks 64, the two clamping blocks 64 are fixed through adjusting screws 641, the adjusting screws 641 correspond to the waist-shaped grooves 621 one to one, and the adjusting screws 641 penetrate through the corresponding waist-shaped grooves 621; the operator can move the knife 62 to adjust the relative vertical distance between the end of the knife and the end face of the knife disc 61, and then tighten the adjusting screw 641 to clamp the knife 62 by the two clamping blocks 64.

As shown in fig. 4 and 5, the peripheral wall of one end of each of the two clamping blocks 64 located in the sleeve 63 is provided with a circular groove 642 symmetrically distributed about the axis of the sleeve 63, the sleeve 63 is connected with two locking screws 65 through threads, the two locking screws 65 penetrate into the sleeve 63, and two ends penetrating into the sleeve 63 are provided with shaft holes 651 coaxially distributed, a first core column 66 is inserted into the shaft hole 651, one end of the first core column 13 close to the hole of the shaft hole 651 is coaxially provided with a second core column 67, the second core column 67 is integrally formed with the first core column 66, the diameter of the second core column 67 is the same as that of the thread section of the locking screw 65, and one end of the second core column 67 far away from the first core column 66 is provided with an arc 671 with a contour matching with the bottom of the circular groove 642. An operator can rotate the clamping block 64 to adjust the included angle between the blade 62 and the axis of the cutter disc 61, and further adjust the included angle between the blade 62 and the die head 21 when the blade 62 abuts against the die head 21, so that the favorable cutting angle of the blade 62 in the rotating process on the end face of the die head 21 is ensured, and the mechanical wear is reduced.

As shown in fig. 3 and 4, the rotating member 3 includes a central ring 31, the central ring 31 is fixed on the side wall of the support plate 15 and coaxially sleeved outside the mandrel 13, the central ring 31 is provided with an annular first groove 311 away from the support plate 15, the outer peripheral wall of the central ring 31 is provided with an annular second groove 312, the cross sections of the second groove 312 and the first groove 311 are both arc-shaped and both are coaxially distributed with the central ring 31; the side wall of the second fixing ring 16 is provided with a plurality of first steel balls 33 and angle plates 32 which are distributed along the axial direction of the second fixing ring at equal intervals, the first steel balls 33 are embedded on the second fixing ring 16 and can freely roll, and each first steel ball 33 is abutted in the first groove 311; the angle plate 32 is L-shaped, the angle plates 32 are arranged outside the first steel balls 33 and are in sliding connection with the second fixing ring 16, each angle plate 32 moves along the radial direction of the second fixing ring 16, the second steel balls 34 are embedded in one end, facing the axis of the second fixing ring 16, of each angle plate 32, a limiting unit is arranged on each angle plate 32, and after an operator moves the angle plate 32 to enable each second steel ball 34 to abut against the inside of the second groove 312, the angle plate 32 is fixed through the limiting unit, and relative rotation of the second fixing ring 16 is achieved.

The limiting unit comprises a sliding block 35 and a limiting screw 36, the sliding block 35 is in a T shape and is fixed on one side of each corner plate 32 facing the second fixing ring 16, sliding grooves 37 for sliding of the sliding blocks 35 are formed in the side wall of the second fixing ring 16, the sliding grooves 37 are matched with the sliding blocks 35, the limiting screw 36 is in threaded connection with the corner plate 32, the end portions of the limiting screw 36 vertically penetrate through the corner plate 32 and the sliding block 35 and then abut against the bottom of the sliding grooves 37, the sliding block 35 abuts against the groove wall of the sliding grooves 37 through the reverse thrust of the limiting screw 36, the sliding block 35 is limited, and therefore the corner plate 32 is fixed, and the limiting unit is simple and convenient.

As shown in fig. 3, the locking sealing member 5 includes an annular waterproof cover 51, the waterproof cover 51 is coaxially fixed on the shaft seat 12, the outer diameter of the waterproof cover 51 is the same as the outer diameter of the sealing cover 2, and the openings of the waterproof cover 51 and the sealing cover 2 are opposite, an intermediate ring 53 coaxially distributed is arranged on the end surface of the opening of the waterproof cover 51, a first elastic sealing gasket 531 is wrapped on the intermediate ring 53, an adjusting sleeve 52 is connected to the waterproof cover 51 in a threaded manner, an annular second elastic sealing gasket 521 is embedded in the inner wall of the adjusting sleeve 52, the second elastic sealing gasket 521 is positioned on one side facing the sealing cover 2, a plurality of sinking grooves 56 are arranged in the inner ring of the second elastic sealing gasket 521 at equal intervals along the axis of the second elastic sealing gasket 521, each sinking groove; the sealing cover 2 open end is seted up and is had the seal groove 54 relative with intermediate ring 53, and the seal groove 54 groove width is less than the thickness of first elastic sealing pad 531, is equipped with a plurality of annular beads 55 on the sealing cover 2, and bead 55 cross-section is the arc, and a plurality of beads 55 all are located inlet tube 22 towards one side of buckler 51.

When the cutting knife 6 abuts against the end face of the die head 21, the intermediate ring 53 drives the first elastic sealing gasket 531 to be inserted into the sealing groove 54, the waterproof cover 51 abuts against the sealing cover 2, an operator rotates the shift lever 522 to drive the adjusting sleeve 52 to rotate, so that the adjusting sleeve 52 moves towards the sealing cover 2 until the convex ribs 55 are respectively embedded into and abut against the corresponding concave grooves 56, at the moment, the second elastic sealing gasket 521 blocks the gap between the sealing cover 2 and the waterproof cover 51, two seals are constructed together with the first elastic sealing gasket 531, and the sealing performance between the sealing cover 2 and the waterproof cover 51 is improved.

As shown in fig. 2, the driving member 4 includes a screw 41 and a servo motor 42, the screw 41 is rotatably connected to the frame 1 and located between two guide rods 43, an axis of the screw 41 is parallel to a moving direction of the slide 11, one end of the screw 41 is in threaded connection with the slide 11, the servo motor 42 is fixedly installed on the frame 1, and a motor shaft of the servo motor 42 is connected to one end of the screw 41 away from the slide 11 through a coupling 421. The servo motor 42 is started to drive the screw 41 to rotate, and the screw 41 drives the slide 11 to move forward or backward.

The implementation principle of the embodiment of the application is as follows: before working, an operator firstly adjusts the inclination angle and the extension distance of the blade 62, then starts the servo motor 42, drives the sliding seat 11 to advance until the blade 62 abuts against the end face of the die head 21 and the spring 17 is in a compressed state, at the moment, the servo motor 42 is suspended, the first elastic sealing gasket 531 is inserted into the sealing groove 54 along with the intermediate ring 53, then the operator rotates the deflector rod 522 to drive the adjusting sleeve 52 to rotate, so that the adjusting sleeve 52 partially moves onto the sealing cover 2, and a gap between the sealing cover 2 and the waterproof cover 51 is blocked by the second elastic sealing gasket 521; next, an operator connects the water inlet pipe 22 with a water source, the water outlet pipe 23 is connected with the plastic particle dehydrator, and cooling water enters the sealing cover 2 and the waterproof cover 51 through the water inlet pipe 22 and is then upwards output through the water outlet pipe 23; an operator starts the driving motor 18, the driving motor 18 drives the mandrel 13 to rotate, the mandrel 13 drives the cutter 6 to rotate, molten materials in the extruder are extruded into strips through holes in the die head 21, the rotating blades 62 cut the strips, and the strips are cooled by cooling water to form particles.

In the cutting process, the first fixing ring 141 is elastically pushed by the spring 17 to enable the blade 62 to be elastically abutted against the end face of the die head 21 and keep effective fit with the die head 21, the possibility of disturbance of the cutter 6 is reduced, when the extrusion speed of the material strip, the position of the blade 62 or the cutting force fluctuates, the blade 62 can be automatically adjusted timely, the hard contact between the blade 62 and the die head 21 is reduced, the possibility of abrasion and aggravation of the blade 62 and the die head 21 is caused, and the particle forming quality is improved.

The above embodiments are preferred embodiments of the present application, and the protection scope of the present application is not limited by the above embodiments, so: all equivalent changes made according to the structure, shape and principle of the present application shall be covered by the protection scope of the present application.

Claims

1. The underwater plastic granulator is characterized in that: the cutting device comprises a rack (1), a sliding seat (11) is connected to the rack (1) in a sliding mode, a shaft seat (12) is arranged on the sliding seat (11), a mandrel (13) is connected to the shaft seat (12) in a rotating mode, a spline (131) is arranged at one end of the mandrel (13), a key sleeve (14) is sleeved on the spline (131), a cutter (6) is arranged at the end portion of the key sleeve (14), a first fixing ring (141) is arranged on the key sleeve (14), a support plate (15) for the mandrel (13) to penetrate through is arranged on the side wall of the shaft seat (12), a second fixing ring (16) is connected to the side wall of the support plate (15) in a rotating mode through a rotating piece (3), a spring (17) is connected between the second fixing ring (16) and the first fixing ring (141), and a driving motor (18) for driving the mandrel (13, the cutting machine is characterized in that a driving piece (4) used for driving the sliding seat (11) to move is arranged on the rack (1), a sealing cover (2) right opposite to the cutter (6) is arranged on the rack (1), a die head (21) is arranged in the sealing cover (2), and a water inlet pipe (22), a water outlet pipe (23) and a locking sealing piece (5) are arranged on the sealing cover (2).

2. The underwater plastic cutter of claim 1, wherein: the rotating piece (3) comprises a center ring (31) and angle plates (32), the center ring (31) is fixed with the support plate (15), one end of the center ring (31) departing from the support plate (15) is provided with an annular first groove (311), the outer circumferential side wall of the center ring (31) is provided with second grooves (312) which are coaxially distributed, the side wall of the second fixing ring (16) is embedded with a plurality of first steel balls (33), each first steel ball (33) is abutted to the first groove (311), the angle plates (32) are circumferentially distributed along the axis of the second fixing ring (16), each angle plate (32) is radially and slidably connected to the side wall of the second fixing ring (16) along the second fixing ring (16), one end of each angle plate (32) facing the axis of the second fixing ring (16) is embedded with a second steel ball (34), and each second steel ball (34) is abutted to the second groove (312), the gusset (32) is fixed by a restraining unit.

3. The underwater plastic cutter as claimed in claim 2, wherein: the limiting unit comprises sliding blocks (35) and limiting screws (36), the sliding blocks (35) are connected to one side, facing the second fixing ring (16), of the angle plate (32), sliding grooves (37) for the sliding blocks (35) to slide are formed in the second fixing ring (16), the limiting screws (36) are connected to the angle plate (32) in a threaded mode, and the end portions of the limiting screws (36) penetrate through the sliding blocks (35) and abut against the bottoms of the sliding grooves (37).

4. The underwater plastic cutter of claim 1, wherein: the driving piece (4) comprises a screw rod (41) and a servo motor (42), the screw rod (41) is rotatably connected to the rack (1), one end of the screw rod (41) is in threaded connection with the sliding seat (11), the other end of the screw rod is in coaxial connection with a motor shaft of the servo motor (42) through a coupler (421), and the servo motor (42) is installed on the rack (1).

5. The underwater plastic cutter as claimed in claim 4, wherein: the machine frame (1) is provided with two guide rods (43) which are symmetrically distributed relative to the screw rod (41), and the two guide rods (43) penetrate through the sliding seat (11).

6. The underwater plastic cutter of claim 1, wherein: locking seal spare (5) include buckler (51) and adjusting collar (52), buckler (51) are the annular and fix on axle bed (12), buckler (51) external diameter is the same with sealing boot (2) external diameter and both openings distribute relatively, buckler (51) open end is equipped with intermediate ring (53) of coaxial distribution, the parcel has first elastic sealing pad (531) on intermediate ring (53), sealing groove (54) of confession intermediate ring (53) embedding are seted up to sealing boot (2) open end, adjusting collar (52) threaded connection is on buckler (51), inside second elastic sealing pad (521) that is equipped with of adjusting collar (52), second elastic sealing pad (521) are located the butt joint department of sealing boot (2) and buckler (51).

7. The underwater plastic cutter of claim 6, wherein: a plurality of annular convex ribs (55) are arranged on the sealing cover (2), and a sinking groove (56) matched with each convex rib (55) is arranged on the inner side of the second elastic sealing gasket (521).

8. The underwater plastic cutter of claim 1, wherein: cutter (6) are including blade disc (61) and blade (62), be equipped with a plurality of sleeve (63) that distribute along blade disc (61) axis equidistance on blade disc (61) the periphery, it has two clamp splice (64), two to peg graft in sleeve (63) clamp splice (64) are fixed through adjusting screw (641), blade (62) are located between two clamp splice (64), and offer waist type groove (621) that supply the screw to pass on blade (62), threaded connection has locking screw (65) on sleeve (63), locking screw (65) tip is worn into in sleeve (63) and is supported tightly with clamp splice (64).

9. The underwater plastic cutter of claim 8, wherein: locking screw (65) and clamp splice (64) one-to-one, two all offer on clamp splice (64) and supply locking screw (65) male annular (642), coaxial distribution's shaft hole (651) have been seted up to locking screw (65) tip, it has first stem (66) to peg graft in shaft hole (651), the one end that shaft hole (651) hole bottom was kept away from in first stem (66) is fixed with second stem (67), second stem (67) tip is equipped with cambered surface (671) with annular (642) matched with.

10. The underwater plastic cutter of claim 6, wherein: and a deflector rod (522) is vertically arranged on the adjusting sleeve (52).