Plastic cavity piece forming device

Abstract

The invention relates to the field of blow molding, in particular to a plastic cavity piece forming device. According to a traditional cutting mode, it is possibly difficult to guarantee that a notch is completely flat, if the lower end of a parison is not flat, when an infrared sensor is used for triggering a clamping plate to conduct clamping, clamping is not tight, parison air leakage is caused, then the subsequent inflation forming stage fails, and the product quality and the production efficiency are affected. A plastic cavity piece forming device comprises a bottom plate and the like. A plastic extruding machine is arranged on one side of the bottom plate, an extruding machine head is arranged on the plastic extruding machine, a positioning support is fixedly connected to the bottom plate, two fixing frames are connected to the positioning support in a sliding mode, a first mold is fixedly connected to one fixing frame, a second mold is fixedly connected to the other fixing frame, and the first mold and the second mold are fixedly connected to the bottom plate. And a mold closing mechanism is arranged on the bottom plate. And the cutting knife is aligned with the lower surface of the extruder head to cut the extruded parison, so that the lower end of the parison extruded subsequently is smoother.

Description

Technical Field

[0001] This invention relates to the field of blow molding, and more particularly to a plastic cavity part molding apparatus. Background Technology

[0002] In the field of plastic extrusion molding, especially in the manufacturing of hollow products or complex cavity parts, the quality of the preform and the subsequent demolding process are crucial. Extrusion molding is widely used in the production of products such as pipes, rods, and profiles. The process involves heating and pressurizing plastic to continuously form the material through a die in a flowing state.

[0003] However, when the extruded parison is used for subsequent blow molding or die-cutting, poor flatness of the cut at the lower end of the parison can cause a series of problems. Traditional cutting methods may not be able to guarantee a completely flat cut. If the lower end of the parison is not flat, the clamping will not be tight when the clamping plate is triggered by an infrared sensor, causing air leakage in the parison. This will lead to the failure of the subsequent inflation molding stage, affecting product quality and production efficiency. Summary of the Invention

[0004] In order to overcome the shortcomings of the prior art, the present invention provides a plastic cavity part forming device that can better ensure the flatness of the preform cutting and does not affect the clamping.

[0005] The technical implementation of the present invention is as follows: a plastic cavity part forming device includes a base plate, a plastic extruder is provided on one side of the base plate, the plastic extruder is provided with an extruder head, a positioning bracket is fixedly connected to the base plate, and two fixed frames are slidably connected to the positioning bracket. One fixed frame is fixedly connected to a mold one, and the other fixed frame is fixedly connected to a mold two. The base plate is provided with a mold closing mechanism, which includes a second slide rail and two electric slides. The plastic extruder extrudes molten plastic downward into a tubular preform, and then the two electric slides respectively push the mold one and the mold two to move towards each other, clamp the preform, and close the molds to complete the blow molding of the cavity part.

[0006] Furthermore, the mold clamping mechanism includes a first slide rail, which is fixedly connected to the base plate. Two electric sliders are slidably connected to the first slide rail. Each electric slider is fixedly connected to a clamping plate. The two clamping plates are symmetrically arranged. An infrared transmitter and an infrared receiver are fixedly fixed on the side of the two electric sliders that are close to each other. The infrared transmitter and the infrared receiver are both located below the clamping plates. The infrared receiver is electrically connected to the electric slider. Four second slide rails are fixedly connected to the base plate. Two second slide rails form a group. An electric carriage is slidably connected between the two second slide rails in each group. Two connecting rods are fixedly connected to one side of each fixed frame. The two connecting rods on each fixed frame are slidably connected to the upper part of the electric carriage. A connecting spring connects the electric carriage and the connecting rods.

[0007] Furthermore, it also includes a cutting mechanism, which is located on one side of the plastic extruder. The cutting mechanism includes a support block, which is fixedly connected to one side of the plastic extruder. A swing rod is rotatably connected to the support block, and a return spring is connected to the swing rod and the support block. A cutter is rotatably connected to one side of the swing rod, and a torsion spring is connected between the cutter and the swing rod. A grinding plate is fixedly connected to one side of the support block, and the upper surface of the grinding plate contacts the cutting edge of the cutter. The upper surface of the grinding plate is fan-shaped. A baffle is fixedly connected to the rotating shaft of the cutter. A pressure rod is fixedly connected to one side of the grinding plate, and the baffle contacts the pressure rod. A positioning plate is fixedly connected to one side of the extruder head, and the lower surface of the positioning plate is flush with the lower surface of the extruder head. A one-way bearing is provided at the lower end of the swing rod, and a gear is provided on the one-way bearing. A rack is fixedly connected to one side of the second mold, and the rack meshes with the gear after the second mold moves.

[0008] Furthermore, it also includes a demolding mechanism, which is disposed on mold one and mold two. The demolding mechanism includes a support frame, which is fixedly connected to one side of the positioning bracket. Four push rods are fixedly connected to the support frame. Horizontal bars are fixedly connected to both sides of mold one. Two sliding rods are slidably connected to each horizontal bar. A return spring is connected to each sliding rod and the two sliding rods are connected together. An arc-shaped piece is connected between the two sliding rods. Fixed blocks are fixedly connected to both sides of mold two. Sliding rods are slidably connected to each fixed block. A tension spring is connected between each sliding rod and the fixed block. One side of each sliding rod contacts one end of a push rod. An arc-shaped piece is connected between the two sliding rods. Both mold one and mold two are provided with grooves corresponding to the arc-shaped pieces.

[0009] The present invention has the following advantages: 1. The cutter is aligned with the lower surface of the extruder head to cut the extruded parison, which makes the lower end of the subsequently extruded parison more flat. If the lower end of the parison is not flat, when the lower end of the parison triggers the infrared receiver to control the clamping plate to hold it, the clamping plate cannot fully hold the parison, resulting in air leakage of the parison and thus failure of molding.

[0010] 2. During mold closing and molding, after the preform is squeezed, the excess part at the edge is held by the first and second arc-shaped pieces. The first and second arc-shaped pieces move out of the groove in sequence, which allows the molded plastic cavity part to be demolded from the two molds in sequence. Since the cavity part is curved, compared with the existing synchronous demolding method, demolding in sequence can avoid the problem of uneven adhesion caused by uneven demolding force due to inconsistent cooling and shrinkage on both sides. Demolding in sequence will make the shape of the cavity part less likely to be damaged. Attached Figure Description

[0011] Figure 1 This is a three-dimensional structural diagram of the present invention.

[0012] Figure 2 This is a three-dimensional structural diagram of mold one of the present invention.

[0013] Figure 3 This is a three-dimensional structural diagram of mold two of the present invention.

[0014] Figure 4 This is a three-dimensional structural diagram of the cutting mechanism of the present invention.

[0015] Figure 5 This is a three-dimensional structural diagram of the mold closing mechanism of the present invention.

[0016] Figure 6 For the present invention Figure 5 A magnified three-dimensional structural diagram at point A in the middle.

[0017] Figure 7 This is a three-dimensional structural diagram of the demolding mechanism of the present invention.

[0018] Figure 8 This is a schematic diagram of the three-dimensional separation structure of the cutting mechanism of the present invention.

[0019] Figure 9 For the present invention Figure 7 A magnified three-dimensional structural diagram at point B.

[0020] Figure 10 For the present invention Figure 7 A magnified three-dimensional structural diagram at point C.

[0021] Figure 11 This is a three-dimensional structural diagram of sliding rod one and sliding rod two of the present invention.

[0022] The meanings of the reference numerals in the figure are as follows: 1: Base plate; 21: Plastic extruder; 22: Extruder head; 31: Positioning bracket; 32: Fixing frame; 33: Mold one; 34: Mold two; 41: First slide rail; 42: Electric slider; 43: Clamping plate; 441: Infrared transmitter; 442: Infrared receiver; 45: Second slide rail; 46: Electric carriage; 47: Connecting rod; 48: Connecting spring; 51: Support block; 52: Swing rod. 53: Return spring; 54: Cutting blade; 55: Torsion spring; 56: Sharpening plate; 57: Baffle plate; 58: Pressure rod; 59: Positioning plate; 510: One-way bearing; 511: Gear; 512: Rack; 61: Support frame; 62: Top rod; 63: Crossbar; 64: Sliding rod one; 65: Return spring; 66: Arc-shaped piece one; 67: Fixing block; 68: Sliding rod two; 69: Tension spring; 610: Arc-shaped piece two. Detailed Implementation

[0023] References to embodiments herein mean that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0024] A plastic cavity molding device, such as Figure 1-11 As shown, the device includes a base plate 1, a plastic extruder 21 on one side of the base plate 1, an extruder head 22 on the plastic extruder 21, a positioning bracket 31 fixedly connected to the base plate 1, and two fixed frames 32 slidably connected to the positioning bracket 31. One fixed frame 32 is fixedly connected to a first mold 33, and the other fixed frame 32 is fixedly connected to a second mold 34. The base plate 1 is provided with a mold closing mechanism, which includes a second slide rail 45 and two electric slides 46. The plastic extruder 21 extrudes molten plastic downwards into a tubular preform. Then, the two electric slides 46 respectively push the first mold 33 and the second mold 34 to move towards each other, clamp the preform, and close the mold to complete the blow molding of the cavity part.

[0025] The mold clamping mechanism includes a first slide rail 41, which is fixedly connected to the base plate 1. Two electric sliders 42 are slidably connected to the first slide rail 41. Each electric slider 42 is fixedly connected to a clamping plate 43. The two clamping plates 43 are symmetrically arranged. An infrared transmitter 441 and an infrared receiver 442 are fixedly fixed on the side of the two electric sliders 42 that are close to each other. The infrared transmitter 441 and the infrared receiver 442 are both located below the clamping plate 43. The infrared receiver 442 is electrically connected to the electric slider 42. Four second slide rails 45 are fixedly connected to the base plate 1. Two second slide rails 45 form a group. An electric carriage 46 is slidably connected between the two second slide rails 45 in each group. Two connecting rods 47 are fixedly connected to one side of each fixed frame 32. The two connecting rods 47 on each fixed frame 32 are slidably connected to the upper part of the electric carriage 46. A connecting spring 48 is connected between the electric carriage 46 and the connecting rods 47.

[0026] The device also includes a cutting mechanism located on one side of the plastic extruder 21. The cutting mechanism includes a support block 51 fixedly connected to one side of the plastic extruder 21. A swing rod 52 is rotatably connected to the support block 51, and a return spring 53 is connected to the swing rod 52 and the support block 51. A cutter 54 is rotatably connected to one side of the swing rod 52, and a torsion spring 55 connects the cutter 54 to the swing rod 52. A grinding plate 56 is fixedly connected to one side of the support block 51, and the upper surface of the grinding plate 56 contacts the cutting edge of the cutter 54. The upper surface of the grinding plate 56 is fan-shaped. A baffle 57 is fixedly connected to the rotating shaft of the cutter 54. A pressure rod 58 is fixedly connected to one side of the grinding plate 56. The baffle 57 contacts the pressure rod 58. A positioning plate 59 is fixedly connected to one side of the extruder head 22. The lower surface of the positioning plate 59 is flush with the lower surface of the extruder head 22. A one-way bearing 510 is provided at the lower end of the swing rod 52. A gear 511 is provided on the one-way bearing 510. A rack 512 is fixedly connected to one side of the mold 34. The rack 512 meshes with the gear 511 after the mold 34 moves.

[0027] In actual operation, the product is a symmetrical and curved hollow plastic sheet. The plastic extruder 21 extrudes a tubular preform through the extruder head 22. As the preform is continuously extruded downwards, when the lower end of the preform appears between the infrared transmitter 441 and the infrared receiver 442, blocking signal transmission, the infrared receiver 442 is triggered, thereby controlling the electric slider 42 to drive the two clamping plates 43 to clamp and seal the lower end of the preform. After clamping, the electric carriage 46 is activated to drive the two molds to close, completing the blow molding process. Mold 2 34 is in During mold closing, the rack 512 moves. After the rack 512 moves a certain distance, the two molds close and remain stationary. The rack 512 then meshes with the gear 511. The electric slide 46 continues to move a certain distance, stretching the connecting spring 48. The rack 512 drives the gear 511 to rotate at a certain angle. At this time, the rotation of the gear 511 does not drive the swing rod 52 to rotate through the one-way bearing 510. When the two electric slides 46 return to their original positions in a direction away from each other, the rack 512 will first drive the gear 511 to rotate. Then, the one-way bearing 510 drives the swing rod 52 to swing at a certain angle, the return spring 53 is twisted, which in turn drives the cutter 54 to swing. Initially, the cutter 54 is in an inclined state, and the torsion spring 55 is in a twisted state. After the cutter 54 swings at a certain angle, the baffle 57 disengages from the pressure rod 58, and the torsion spring 55 drives the cutter 54 to rotate to a horizontal state. After the cutter 54 continues to swing, the upper surface of the cutter 54 will contact the lower surface of the positioning plate 59, thereby aligning the cutter 54 with the lower surface of the extruder head 22, and thus aligning the extruded parison. Cutting is performed to make the lower end of the next extruded parison more flat. If the lower end of the next parison is not flat, when the lower end of the parison triggers the infrared receiver 442 to control the clamping plate 43 to clamp, the clamping plate 43 cannot fully clamp the parison, resulting in air leakage in the parison and failure of molding. After the rack 512 and gear 511 disengage, the return spring 53 drives the swing rod 52 and the cutter 54 to swing and reset. The cutter 54 will rotate again to the tilted state, and the blade will rub against the surface of the grinding plate 56 to achieve self-sharpening of the cutter 54.

[0028] Example 2 Based on Example 1, such as Figure 7-11As shown, it also includes a demolding mechanism, which is disposed on the first mold 33 and the second mold 34. The demolding mechanism includes a support frame 61, which is fixedly connected to one side of the positioning bracket 31. Four push rods 62 are fixedly connected to the support frame 61. Crossbars 63 are fixedly connected to both sides of the first mold 33. Two sliding rods 64 are slidably connected to each crossbar 63. A return spring 65 is connected to the sliding rods 64 and the crossbars 63. An arc-shaped piece 66 is connected between 64. Fixing blocks 67 are fixedly connected to both sides of the mold 34. A sliding rod 68 is slidably connected to the fixing block 67. A tension spring 69 is connected between the sliding rod 68 and the fixing block 67. One side of the sliding rod 68 contacts one end of the top rod 62. An arc-shaped piece 610 is connected between the two sliding rods 68. Both the mold 33 and the mold 34 are provided with grooves corresponding to the arc-shaped piece 66 and the arc-shaped piece 610.

[0029] After the two molds are closed, the first arc-shaped piece 66 and the second arc-shaped piece 610 will be squeezed into their corresponding grooves. At this time, the return spring 65 is stretched, and the tension spring 69 is in its original length. When the two molds are separated, because the return spring 65 is stretched and the tension spring 69 is in its original length, the second arc-shaped piece 610 will remain in its groove, while the first arc-shaped piece 66 will be moved out of its groove by the return spring 65. After the return spring 65 returns to its original length, the second arc-shaped piece 610 continues to move a distance with the second mold 34. The side of the sliding rod 68 contacts the push rod 62, and then the second arc-shaped piece 610 remains stationary. The second mold 34 continues to reset, thus making the arc-shaped piece 610... When piece 2 610 moves out of the groove, arc-shaped piece 1 66 moves out of the groove first, and then arc-shaped piece 2 610 moves out of the groove. During mold closing and forming, after the parison is squeezed, the excess part at the edge is held by arc-shaped piece 1 66 and arc-shaped piece 2 610. The arc-shaped piece 1 66 and arc-shaped piece 2 610 move out of the groove in sequence, which allows the molded plastic cavity part to be demolded from the two molds in sequence. Since the cavity part is curved, compared with the synchronous demolding method of the prior art, demolding in sequence can avoid the problem of uneven adhesion caused by uneven cooling and shrinkage on both sides, resulting in uneven demolding force and deformation. Demolding in sequence will make the shape of the cavity part less likely to be damaged.

[0030] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A plastic cavity molding device, characterized in that: The device includes a base plate (1), on one side of which is a plastic extruder (21). The plastic extruder (21) is equipped with an extruder head (22). A positioning bracket (31) is fixedly connected to the base plate (1). Two fixed frames (32) are slidably connected to the positioning bracket (31). One of the fixed frames (32) is fixedly connected to a mold (33), and the other fixed frame (32) is fixedly connected to a mold (34). A mold closing mechanism is provided on the base plate (1). The mold closing mechanism includes a second slide rail (45) and two electric slides (46). The plastic extruder (21) extrudes the molten plastic downward into a tubular preform. Then, the two electric slides (46) push the mold (33) and the mold (34) to move towards each other. After clamping the preform, the mold is closed to complete the blow molding of the cavity part.

2. The plastic cavity molding apparatus according to claim 1, characterized in that: The mold closing mechanism includes a first slide rail (41), which is fixedly connected to the base plate (1). Two electric sliders (42) are slidably connected to the first slide rail (41). Each electric slider (42) is fixedly connected to a clamping plate (43). The two clamping plates (43) are symmetrically arranged. An infrared transmitter (441) and an infrared receiver (442) are fixedly fixed on the side of the two electric sliders (42) that are close to each other. Four second slide rails (45) are fixedly connected to the base plate (1). Two second slide rails (45) form a group. An electric carriage (46) is slidably connected between the two second slide rails (45) in each group. Two connecting rods (47) are fixedly connected to one side of each fixed frame (32). The two connecting rods (47) on each fixed frame (32) are slidably connected to the upper part of the electric carriage (46). A connecting spring (48) is connected between the electric carriage (46) and the connecting rods (47).

3. A plastic cavity molding apparatus according to claim 2, characterized in that: The infrared transmitter (441) and the infrared receiver (442) are both located below the clamp (43), and the infrared receiver (442) is electrically connected to the electric slider (42).

4. A plastic cavity molding apparatus according to claim 1, characterized in that: It also includes a cutting mechanism, which is located on one side of the plastic extruder (21). The cutting mechanism includes a support block (51), which is fixedly connected to one side of the plastic extruder (21). A swing rod (52) is rotatably connected to the support block (51). A return spring (53) is connected to the swing rod (52) and the support block (51). A cutter (54) is rotatably connected to one side of the swing rod (52). A torsion spring (55) is connected between the cutter (54) and the swing rod (52). A grinding plate (56) is fixedly connected to one side of the support block (51). The upper surface of the grinding plate (56) is... The cutting edge of the cutter (54) is in contact with the upper surface of the grinding plate (56), which is fan-shaped. A baffle (57) is fixedly connected to the rotating shaft of the cutter (54). A pressure rod (58) is fixedly connected to one side of the grinding plate (56). The baffle (57) is in contact with the pressure rod (58). A positioning plate (59) is fixedly connected to one side of the extruder head (22). A one-way bearing (510) is provided at the lower end of the swing rod (52). A gear (511) is provided on the one-way bearing (510). A rack (512) is fixedly connected to one side of the mold (34). The rack (512) meshes with the gear (511) after the mold (34) moves.

5. A plastic cavity molding apparatus according to claim 4, characterized in that: The lower surface of the positioning plate (59) is flush with the lower surface of the extruder head (22).

6. A plastic cavity molding apparatus according to claim 3, characterized in that: It also includes a demolding mechanism, which is disposed on the first mold (33) and the second mold (34). The demolding mechanism includes a support frame (61), which is fixedly connected to one side of the positioning bracket (31). Four push rods (62) are fixedly connected to the support frame (61). Cross rods (63) are fixedly connected to both sides of the first mold (33). Two sliding rods (64) are slidably connected to each cross rod (63). The sliding rods (64) are connected to the cross rods (64). 3) A reset spring (65) is connected, and an arc-shaped piece (66) is connected between the two sliding rods (64). Fixing blocks (67) are fixedly connected to both sides of the mold (34). A sliding rod (68) is slidably connected to the fixing block (67). A tension spring (69) is connected between the sliding rod (68) and the fixing block (67). One side of the sliding rod (68) contacts one end of the top rod (62). An arc-shaped piece (610) is connected between the two sliding rods (68).

7. A plastic cavity molding apparatus according to claim 6, characterized in that: Both mold one (33) and mold two (34) are provided with grooves corresponding to arc-shaped piece one (66) and arc-shaped piece two (610).

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