Blow molding method and blow molding equipment

Abstract

The invention provides a blow molding method and blow molding equipment, the blow molding method is implemented based on the blow molding equipment, the blow molding equipment comprises a male die and a female die, and the blow molding method comprises the following steps: clamping the bottom edge of a blank between the male die and the female die and dragging the blank along a first direction, the wrinkles on the blank are unfolded; the male die and the female die are closed, so that part of the blank is located in a blow molding die cavity formed by closing the male die and the female die; and gas is conveyed into the blow molding die cavity, so that the blank located in the blow molding die cavity is attached to the inner wall of the female die. According to the blow molding method and the blow molding equipment, blow molding is not limited to molding of workpieces of hollow structures any more, and the wall thickness can be conveniently adjusted.

Description

Technical Field

[0001] The present invention relates to the technical field of blow molding, and particularly to a blow molding method and a blow molding device. Background Art

[0002] A blow molding device is a plastic processing machine that extrudes plastic particles by heating with a screw, and uses the air pressure blown out by the machine to blow the plastic body onto a cavity of a certain shape to form a product.

[0003] Blow molding has the advantages of low production cost, high efficiency, and being suitable for large-scale production. However, blow molding is usually used to form workpieces with a hollow structure inside, and its use is limited. For existing plastic shell-like or plastic plate-like workpieces, such as the plastic upper cover of a battery pack, etc., the forming process mainly relies on thermoforming, which not only has high processing costs, but also has fewer means to adjust the wall thickness, and cannot meet the requirements of large-scale batch production and application.

[0004] Therefore, there is an urgent need to perform blow molding on non-hollow structure workpieces such as plastic shell-like or plastic plate-like, and to facilitate the adjustment of the wall thickness. Summary of the Invention

[0005] The present invention provides a blow molding method and a blow molding device, so that blow molding is no longer limited to forming workpieces with a hollow structure, and the wall thickness can be conveniently adjusted.

[0006] To achieve the above object, the present invention provides a blow molding method implemented based on a blow molding device, the blow molding device including a male mold and a female mold, and the method includes:

[0007] Clamp the bottom edge of the blank located between the male mold and the female mold and drag the blank in a first direction to unfold the wrinkles on the blank;

[0008] Close the male mold and the female mold so that part of the blank is located in the blow molding cavity formed by the closing of the male mold and the female mold;

[0009] Convey gas into the blow molding cavity so that the blank located in the blow molding cavity fits against the inner wall of the female mold.

[0010] The blow molding method provided by the present invention makes it possible to blow mold plastic shell-like or plastic plate-like structures, is no longer limited to forming workpieces with a hollow structure, reduces production costs, and improves production efficiency. In addition, when forming plastic shell-like or plastic plate-like structures, the blank can be driven to move by a material tensioning assembly and / or a loading and unloading assembly, so that the blank located between the male mold and the female mold is unfolded, thereby reducing the wrinkles of the blank, facilitating the adjustment of the local wall thickness of the blow molded part to be formed, and improving the quality of the blow molded part to be formed.

[0011] In a possible implementation manner, after the punch and the die are closed so that part of the blank is located in the blow molding cavity formed by the closing of the punch and the die, and before the gas is conveyed into the blow molding cavity so that the blank located in the blow molding cavity fits against the inner wall of the die, it further includes:

[0012] Controlling the movement of the auxiliary male mold of the punch and pushing the blank clamped between the punch and the die, so that the blank moves in a direction close to the die.

[0013] In a possible implementation manner, within a preset time after the die starts to move towards the punch for closing until the die and the punch are closed, it further includes:

[0014] Clamping the top of the blank and dragging part of the blank to move in a second direction;

[0015] Clamping the bottom edge of the blank and dragging part of the blank to move in the second direction.

[0016] In a possible implementation manner, within a preset time after the die starts to move towards the punch for closing until the die and the punch are closed, it further includes:

[0017] Clamping the top of the blank and driving part of the blank to move in a third direction.

[0018] In a possible implementation manner, after the punch and the die are closed so that part of the blank is located in the blow molding cavity formed by the closing of the punch and the die, and before the gas is conveyed into the blow molding cavity so that the blank located in the blow molding cavity fits against the inner wall of the die, it further includes:

[0019] Evacuating the air between the cavity of the die and the blank, so that the blank fits against the inner wall of the cavity of the die.

[0020] The present invention further provides a blow molding device for implementing the above blow molding method. The blow molding device includes:

[0021] At least one blow molding assembly, the blow molding assembly includes a punch and a die cooperating with the punch, the punch and the die are combined to form a blow molding cavity, and the punch is configured to blow the blank located in the blow molding cavity so that the blank fits against the inner wall of the die in the blow molding cavity;

[0022] At least two blank tensioning components, which are configured to grip the edge of the blank located between the punch and the die and drive the blank to move so as to reduce wrinkles of the blank.

[0023] In a possible implementation manner, the blank tensioning component includes a mounting base, a gripper unit and a moving unit. The moving unit is connected to the die, the gripper unit is arranged on the mounting base, and the moving unit is used to drive the mounting base to move in a first direction and / or a second direction, where the first direction is the direction away from the center of the blank, and the second direction is the same as or opposite to the die closing direction of the punch and the die.

[0024] In a possible implementation manner, the gripper unit includes a first clamping jaw, a second clamping jaw and a first driving member. The first clamping jaw and the first driving member are both connected to the mounting base. The first driving member includes a rotating shaft, and the second clamping jaw is connected to the rotating shaft. The first driving member is used to drive the second clamping jaw to switch between a state of closing with the first clamping jaw and a state of separating from the first clamping jaw.

[0025] In a possible implementation manner, the moving unit includes: a second driving member and a third driving member. The third driving member is connected to the mounting base, the second driving member is connected to the die, the second driving member is used to drive the mounting base to move in a direction the same as or opposite to the first direction, and the third driving member is used to drive the mounting base to move in the second direction.

[0026] In a possible implementation manner, it further includes a loading and unloading component. The loading and unloading component includes a lifting table, at least one displacement unit and at least one clamping unit. The displacement unit is arranged between the lifting table and the clamping unit. The lifting table is configured to enable the clamping unit to move in a third direction. The clamping unit is located above the blow molding component, and the clamping unit is used to clamp the top of the blank. The displacement unit is used to drive the clamping unit to move in the second direction.

[0027] In a possible implementation manner, the clamping unit includes a first clamping rod and a second clamping rod, and a clamping cavity for clamping the blank is formed between the first clamping rod and the second clamping rod;

[0028] The length of the first clamping rod and the length of the second clamping rod are both greater than or equal to the width of the blank.

[0029] In a possible implementation manner, the male mold includes a main body portion, an auxiliary male mold, and a telescopic member. The auxiliary male mold is movably disposed on a side of the main body portion facing the female mold. The auxiliary male mold is connected to the main body portion through the telescopic member, and the auxiliary male mold is located in the blow molding cavity. At least one air hole is formed on a surface of the auxiliary male mold facing the female mold. The auxiliary male mold is configured to push the blank to move along the second direction.

[0030] In a possible implementation manner, the number of the blow molding assemblies is two. The male molds of the two blow molding assemblies are connected as a whole and are oppositely disposed.

[0031] The blow molding method and blow molding equipment provided by the present invention can form workpieces with non-hollow structures, and effectively solve the problems of material accumulation caused by blank wrinkles and wall thickness deviation caused by small blank stretching in the flanging corner area of the workpiece, as well as solve the problem of thin wall thickness caused by large blank stretching in the top surface and side corner areas of the formed workpiece, and improve the wall thickness uniformity of the workpiece.

[0032] In addition to the technical problems solved by the embodiments of the present invention described above, the technical features constituting the technical solutions, and the beneficial effects brought by the technical features of these technical solutions, other technical problems that can be solved by a blow molding method and blow molding equipment provided by the embodiments of the present invention, other technical features included in the technical solutions, and the beneficial effects brought by these technical features will be further described in detail in the specific implementation manner. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0034] Figure 1 FIG. 18 is a schematic three-dimensional structure diagram of a blow molding part formed by the blow molding method and blow molding equipment provided by the embodiments of the present invention;

[0035] Figure 2 FIG. 22 is a front view of the blow molding equipment provided by the embodiments of the present invention;

[0036] Figure 3 FIG. 26 is a schematic three-dimensional structure diagram of a partial structure of the blow molding equipment provided by the embodiments of the present invention clamping a blank;

[0037] Figure 4 FIG. 30 is a schematic structural diagram of a blank tensioning assembly of the blow molding equipment provided by the embodiments of the present invention;

[0038] Figure 5 Schematic structural diagram of the loading and unloading assembly of the blow molding device provided by the embodiment of the present invention;

[0039] Figure 6 Another schematic structural diagram of the loading and unloading assembly of the blow molding device provided by the embodiment of the present invention;

[0040] Figure 7 Another schematic structural diagram of the loading and unloading assembly of the blow molding device provided by the embodiment of the present invention;

[0041] Figure 8 Schematic structural diagram before the auxiliary male mold moves in the male mold of the blow molded part provided by the embodiment of the present invention;

[0042] Figure 9 Schematic structural diagram after the auxiliary male mold moves in the male mold of the blow molding device provided by the embodiment of the present invention;

[0043] Figure 10 Right view of the male mold of the blow molding device provided by the embodiment of the present invention;

[0044] Figure 11 Schematic structural diagram of the female mold of the blow molding device provided by the embodiment of the present invention;

[0045] Figure 12 is Figure 3 Schematic structural diagram from another perspective;

[0046] Figure 13 is Figure 3 Schematic structural diagram from another perspective;

[0047] Figure 14 is Figure 3 Schematic structural diagram from another perspective;

[0048] Figure 15 Flow chart of the blow molding method provided by the embodiment of the present invention;

[0049] Figure 16 Another flow chart of the blow molding method provided by the embodiment of the present invention;

[0050] Figure 17 Another flow chart of the blow molding method provided by the embodiment of the present invention;

[0051] Figure 18 Another flow chart of the blow molding method provided by the embodiment of the present invention;

[0052] Figure 19 Another flow chart of the blow molding method provided by the embodiment of the present invention;

[0053] Figure 20 Another flowchart of the blow molding method provided by the embodiment of the present invention.

[0054] Description of reference numerals:

[0055] 10 - Blow molding assembly;

[0056] 20 - Punch;

[0057] 21 - Main body part;

[0058] 22 - Auxiliary male mold;

[0059] 221 - Air hole;

[0060] 23 - Telescopic member;

[0061] 30 - Female mold;

[0062] 31 - Exhaust hole;

[0063] 40 - Blank tensioning assembly;

[0064] 41 - Mounting base;

[0065] 42 - Gripping unit;

[0066] 421 - First jaw;

[0067] 422 - Second jaw;

[0068] 423 - First driving member;

[0069] 424 - Gripping cavity;

[0070] 425 - Gripping surface;

[0071] 43 - Moving unit;

[0072] 431 - Second driving member;

[0073] 432 - Third driving member;

[0074] 50 - Loading and unloading assembly;

[0075] 51 - Lifting table;

[0076] 52 - Displacement unit;

[0077] 53 - Clamping unit;

[0078] 531 - First clamping rod;

[0079] 532 - Second clamping rod;

[0080] 533 - Clamping cavity;

[0081] 70 - Battery case;

[0082] 71 - Top panel;

[0083] 72 - Side wall panel;

[0084] 73 - Flange;

[0085] 80 - Blank. Detailed implementation manners

[0086] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions in the present invention will be clearly and completely described below with reference to the accompanying drawings in the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present invention without creative efforts shall fall within the protection scope of the present invention.

[0087] Plastic particles are melted and plasticized by an extruder, and are respectively extruded from the left outlet and / or the right outlet of the die to form sheet-like molten blanks. The extruded blanks are in a molten state, and there are easily wavy patterns or wrinkles on the surface of the blanks, resulting in wrinkles or blank accumulation during the blow molding process, which affects the quality of the formed blow molded parts.

[0088] In view of this, a blow molding method and a blow molding device provided by the present invention can form workpieces with non-hollow structures. By pulling the edge of the blank, the wrinkles of the blank can be smoothed out, effectively solving the problems of material accumulation caused by blank wrinkles and wall thickness deviation caused by small blank stretching in the flanging corner area of the workpiece, and can also solve the problem of wall thickness deviation caused by large blank stretching in the top and side corner areas of the formed workpiece, which helps to adjust the wall thickness of the formed workpiece and ensure that the wall thickness meets the requirements.

[0089] The following takes the battery case 70 as the workpiece for blow molding, and refers to Figure 1 As shown, the battery case 70 includes a top panel 71 and a side wall panel 72 connected to the edge of the top panel 71. The edge of the side wall panel 72 away from the top panel 71 has a flange 73, and the flange 73 surrounds the edge of the side wall panel 72 for one week. The battery case 70 is installed on the battery pack, and the battery case 70 and the lower tray of the battery pack form a sealed whole.

[0090] The following describes the blow molding method and the blow molding device provided by the embodiments of the present invention with reference to the accompanying drawings.

[0091] Refer to Figure 15 As shown, the present invention also provides a blow molding method, which is implemented based on a blow molding device. The blow molding device includes a male mold 20 and a female mold 30. The method includes:

[0092] S10. Clamp the bottom edge of the blank located between the punch and the die and pull the blank in the first direction to unfold the wrinkles on the blank.

[0093] S20. Close the punch and the die so that part of the blank is located in the blow molding cavity formed by the closing of the punch and the die.

[0094] S30. Deliver gas into the blow molding cavity so that the blank located in the blow molding cavity fits against the inner wall of the die.

[0095] A blow molding method provided by the present invention makes it possible to form plastic shell-like or plastic plate-like structures, no longer limited to forming workpieces with a hollow structure, reducing production costs and improving production efficiency. In addition, when forming plastic shell-like or plastic plate-like structures, the bottom edge of the blank located between the punch and the die can be clamped and the blank 80 can be pulled in the first direction to unfold the wrinkles on the blank 80, thereby reducing the local accumulation of the blank 80 in the blow molding cavity, facilitating the adjustment of the local wall thickness of the formed blow molded part, and improving the quality of the formed blow molded part.

[0096] In this example, the first direction is the direction away from the center of the blank 80. The blow molding device may include a blank tensioning assembly 40. By clamping the bottom edge of the blank 80 through the blank tensioning assembly 40 and driving the clamped part of the blank 80 to move in the first direction, the wrinkled blank 80 can be unfolded, reducing the wrinkles in the blank 80, thereby improving the quality of the formed blow molded part.

[0097] Among them, closing the punch 20 and the die 30 is achieved by controlling the die 30 to move in the direction close to the punch 20, that is, the die 30 moves in the second direction.

[0098] Exemplarily, air holes 221 are provided on the inner wall of the cavity of the punch 20. The air outlet nozzle of the air pressure generating device is communicated with the air holes 221, and the high-pressure gas output by the air pressure generating device is delivered into the blow molding cavity through the air holes 221. The gas delivered into the blow molding cavity can be air. The air blows the blank 80, so that the blank 80 located in the blow molding cavity fits against the inner wall of the die 30 under the action of the gas pressure, and the high-pressure gas separates the punch 20 and the blank 80.

[0099] In a possible implementation manner, with reference to Figure 16 as shown, after S20. Close the punch and the die so that part of the blank is located in the blow molding cavity formed by the closing of the punch and the die, and before S30. Deliver gas into the blow molding cavity so that the blank located in the blow molding cavity fits against the inner wall of the die, the following is further included:

[0100] S40. Control the movement of the auxiliary male die of the punch and push the blank clamped between the punch and the die so that the blank moves in the direction close to the die.

[0101] Under the action of the auxiliary male die 22 pushing the blank 80, the substantially flat blank 80 can form a concave cavity recessed into the interior of the die 30 in the blow molding cavity, improving the structural diversity of the formed blow molded part.

[0102] In a possible implementation manner, whether to operate the auxiliary male die 22 of the punch 20 is selected according to the height of the side panel 72. For example, when the height of the side panel 72 ≤ 100 mm, there is no need for the auxiliary male die 22 of the punch 20 to push the blank 80 clamped in the blow molding cavity in the direction close to the die 30. When the height of the side panel 72 > 100 mm, it is necessary for the auxiliary male die 22 of the punch 20 to push the blank 80 clamped in the blow molding cavity in the direction close to the die 30.

[0103] In a possible implementation manner, referring to Figure 17 and Figure 18 As shown, within a preset time after the die 30 starts to move towards the punch 20 for mold closing until the die 30 and the punch 20 are closed, it further includes:

[0104] S50. Clamp the top of the blank and drag a part of the blank to move in the second direction;

[0105] S60. Clamp the bottom edge of the blank and drag a part of the blank to move in the second direction.

[0106] In a possible implementation manner, the preset time can be 0 - 15 seconds.

[0107] Among them, the loading and unloading component 50 of the blow molding device can be used to clamp the top of the blank 80 and drag the blank 80 to move in the second direction. The material tensioning component 40 of the blow molding device can be used to clamp the bottom edge of the blank 80 and drag the blank 80 to move in the second direction. Through the cooperation of the loading and unloading component 50 and the material tensioning component 40 to drag the blank 80 to move, it is beneficial to solve problems such as material accumulation and insufficient wall thickness at the corner positions of the top panel 71, side panel 72, and flanging 73, and improve the quality of the formed blow molded part.

[0108] In a possible implementation manner, only the loading and unloading component 50 drives the blank 80 to move in the same or opposite direction as the second direction, and the material tensioning component 40 remains stationary; or only the material tensioning component 40 drags the edge of the blank 80 to move in the same or opposite direction as the second direction, and the loading and unloading component 50 remains stationary. This simplifies the operation steps and can ensure that the wall thickness at the corner positions of the top panel 71, side panel 72, and flanging 73 meets the requirements.

[0109] In a possible implementation manner, the loading and unloading assembly 50 drives the blank 80 to move in the same or opposite direction as the second direction; meanwhile, the blank tensioning assembly 40 pulls the edge of the blank 80 to move in the same or opposite direction as the second direction, so that the wall thickness of each surface of the formed top panel 71, side wall panel 72 and flanging 73 meets the requirements, which helps to make the quality of each surface of the top panel 71, side wall panel 72 and flanging 73 better.

[0110] In a possible implementation manner, with reference to Figure 19 As shown, after the female mold 30 starts to move towards the male mold 20 for mold closing until a preset time after the female mold 30 and the male mold 20 are closed, the following steps are further included:

[0111] S70: Clamp the top of the blank and drive part of the blank to move in the third direction.

[0112] The purpose of step S70 is to drive the blank 80 to move in the blank unloading direction, which can reduce the tensile force on the blank 80. When the auxiliary male mold 22 pushes the blank 80, it can avoid the problem that the local thickness of the blank 80 is too small due to excessive stretching of the blank 80, thereby ensuring the wall thickness of the blow molded part.

[0113] In a possible implementation manner, with reference to Figure 20 As shown, after S20: Close the male mold and the female mold so that part of the blank is located in the blow molding cavity formed by the closing of the male mold and the female mold, and before S30: Deliver gas into the blow molding cavity so that the blank located in the blow molding cavity fits against the inner wall of the female mold, the following steps are further included:

[0114] S80: Extract the air between the cavity of the female mold and the blank, so that the blank fits against the inner wall of the cavity of the female mold.

[0115] In this example, the air between the cavity of the female mold 30 and the blank 80 can be extracted by a negative pressure device, which can ensure the stable fitting of the blank 80 with the cavity of the female mold 30, prevent air residue from affecting the fitting effect of the blank 80 with the female mold 30, and thus ensure the quality of the formed blow molded part.

[0116] The present invention also provides a blow molding method. After S30: Deliver gas into the blow molding cavity so that the blank located in the blow molding cavity fits against the inner wall of the female mold, the steps of pressure holding, cooling and shaping, and opening the blow molding cavity and demolding the blow molded part are further included.

[0117] For the blow molding method provided by the present invention, the wall thickness at the corner positions of the top panel 71 and the side wall panel 72 can also be adjusted by adjusting the gas pressure in the blow molding cavity.

[0118] The opening of the blow molding cavity can be achieved by the movement of the female mold 30 away from the male mold 20, that is, the female mold 30 moves in the direction opposite to the second direction, so that the blow molding cavity opens.

[0119] Since the loading and unloading assembly 50 always holds the top of the blank 80 during the molding process, after the blow molding cavity is opened, the movement of the loading and unloading assembly 50 can drive the blow molded part to be demolded, completing the blow molding.

[0120] Reference Figure 2 and Figure 3 As shown in the reference, the present invention also provides a blow molding device for implementing the above-mentioned blow molding method. The blow molding device includes: at least one blow molding assembly 10 and at least two blank tensioning assemblies 40. The blow molding assembly 10 includes a male mold 20 and a female mold 30 that cooperates with the male mold 20. The male mold 20 and the female mold 30 cooperate to form a blow molding cavity. The male mold 20 is configured to blow the blank 80 located in the blow molding cavity so that the blank 80 fits against the inner wall of the female mold 30 in the blow molding cavity; the blank tensioning assembly 40 is configured to grip the edge of the blank 80 located between the male mold 20 and the female mold 30 and drive the blank 80 to move to reduce the wrinkles of the blank 80.

[0121] The blow molding device provided by the present invention can be used to mold workpieces with non-hollow structures such as plastic shells or plastic plates. By pulling the edge of the blank 80 by the blank tensioning assembly 40, the wrinkles of the blank 80 can be smoothed out, thereby reducing the problem of excessive wall thickness caused by the wrinkles piled up on the blank 80, which helps to adjust the wall thickness of the blow molded part during molding and is convenient to use.

[0122] The shape, depth, width, length, etc. of the blow molding cavity can be flexibly set according to the usage requirements.

[0123] Reference Figure 12 and Figure 13 As shown in the reference, when the number of the blank tensioning assemblies 40 is two, the two blank tensioning assemblies 40 can respectively grip two corner positions at the bottom of the blank 80 and move the two corner positions at the bottom of the blank 80 in directions away from each other, which is beneficial to smoothing out the wrinkles in the blank 80. As the two blank tensioning assemblies 40 move in directions away from each other, the piled-up wrinkles at the corners of the flanging 73 of the blow molded part to be formed will be eliminated, and the wall thickness at the corners of the flanging 73 will be correspondingly thinned.

[0124] In a possible implementation manner, reference Figure 3 and Figure 4As shown, the blank material component 40 includes a mounting base 41, a gripper unit 42, and a moving unit 43. The moving unit 43 is connected to the female mold 30, and the gripper unit 42 is arranged on the mounting base 41. The moving unit 43 is used to drive the mounting base 41 to move in the first direction and / or the second direction. Herein, the first direction is the direction away from the center of the blank 80, and the second direction is the same as or opposite to the mold closing direction of the male mold 20 and the female mold 30. In this example, the first direction refers to Figure 3 the direction indicated by the arrow Y in Figure 3 , and the second direction refers to

[0125] the direction indicated by the arrow X in

[0126] . There is an included angle between the first direction and the second direction. In this example, the included angle between the first direction and the second direction can be 80° - 100°, such as 80°, 85°, 90°, 95°, or 100°.

[0127] The mounting base 41 is used to mount the gripper unit 42 and the moving unit 43. When the moving unit 43 drives the mounting base 41 to move in the first direction, the gripper unit 42 arranged on the mounting base 41 holds the edge of the blank 80 and pulls the blank 80 in the direction away from the center of the blank 80, so as to make the wrinkles on the blank 80 unfold, and it can also achieve the effect of reducing the local wall thickness of the blow - molded part. After the male mold 20 and the female mold 30 are closed, for example, to form Figure 1 the battery case 70 as shown, when the moving unit 43 drives the mounting base 41 to move in the second direction, it can assist the blank in local stretching and facilitate the adjustment of the wall thickness at the corner where the side wall panel 72 and the top panel 71 are connected.

[0128] In a possible implementation manner, the gripper unit 42 includes a first jaw 421, a second jaw 422, and a first driving member 423. Both the first jaw 421 and the first driving member 423 are connected to the mounting base 41. The first driving member 423 includes a rotating shaft, and the second jaw 422 is connected to the rotating shaft. The first driving member 423 is used to drive the second jaw 422 to switch between the state of being closed with the first jaw 421 and the state of being separated from the first jaw 421.

[0129] To improve the clamping effect of the gripper unit 42 on the blank 80, a gripping cavity 424 is formed between the first jaw 421 and the second jaw 422, and a gripping surface 425 is formed on the surface of the first jaw 421 facing the gripping cavity 424, and a gripping surface 425 is also formed on the surface of the second jaw 422 facing the gripping cavity 424. The gripping surface 425 can be a wavy surface or a toothed surface. Of course, the gripping surface 425 can also be distributed with convex points and grooves, so as to improve the clamping effect on the blank 80.

[0130] In this example, the position of the first jaw 421 is fixed relative to the mounting base 41, and the second jaw 422 rotates relative to the mounting base 41 to open and close the gripping cavity 424. Among them, the second jaw 422 is in a state of being closed with the first jaw 421, that is, the state where the gripping cavity 424 is closed; the second jaw 422 is in a state of being separated from the first jaw 421, that is, the state where the gripping cavity 424 is open.

[0131] In a possible implementation manner, the first driving member 423 is a rotary cylinder or a motor. One end of the second jaw 422 far from the gripping surface 425 is connected to a rotating shaft. When the rotating shaft rotates, it drives the second jaw 422 to rotate, so that the gripping surface 425 of the second jaw 422 rotates towards the direction close to the first jaw 421 to achieve a clamping action, or the gripping surface 425 of the second jaw 422 rotates away from the first jaw 421 to achieve a releasing action.

[0132] The first jaw 421 is connected to the top surface of the mounting base 41 by, but not limited to, welding, screws, or bolts. And the gripping surface 425 of the first jaw 421 is located outside the mounting base 41 to prevent the mounting base 41 from affecting the gripping actions of the first jaw 421 and the second jaw 422.

[0133] In a possible implementation manner, the moving unit 43 includes: a second driving member 431 and a third driving member 432. The third driving member 432 is connected to the mounting base 41, and the second driving member 431 is connected to the female mold 30. The second driving member 431 is used to drive the mounting base 41 to move in the same or opposite direction as the first direction, and the third driving member 432 is used to drive the mounting base 41 to move in the second direction. The moving unit 43 makes the movement of the mounting base 41 and the gripper unit 42 more flexible and convenient, and is convenient for independently controlling the second driving member 431 and the third driving member 432.

[0134] In a possible implementation manner, the second driving member 431 can be a telescopic cylinder, and the third driving member 432 can also be a telescopic cylinder. The cylinder body of the second driving member 431 is connected to the female mold 30, and the telescopic rod of the second driving member 431 is connected to the cylinder body of the third driving member 432, so that the mounting base 41 and the third driving member 432 as a whole can move in the same or opposite direction as the first direction.

[0135] In a possible implementation manner, the telescopic rod of the third driving member 432 is connected to the mounting base 41. Under the pushing action of the third driving member 432, the mounting base 41 moves in the same or opposite direction as the second direction.

[0136] In a possible implementation manner, refer to Figure 3 , Figure 5 and Figure 6As shown, it further includes a loading and unloading assembly 50. The loading and unloading assembly 50 includes a lifting table 51, at least one displacement unit 52, and at least one clamping unit 53. The displacement unit 52 is arranged between the lifting table 51 and the clamping unit 53. The lifting table 51 is configured to move the clamping unit 53 in the third direction. The clamping unit 53 is located above the blow molding assembly 10. The clamping unit 53 is used to clamp the top of the blank 80, and the displacement unit 52 is used to drive the clamping unit 53 to move in the second direction.

[0137] Reference Figure 3 、 Figure 5 and Figure 7 As shown, the lifting table 51 can achieve the movement in the third direction through a telescopic cylinder. The third direction refers to the direction indicated by the Z-axis in Figure 7 . In this example, there is an included angle between the third direction and both the first direction and the second direction. For example, the third direction can be the blank unloading direction. In this example, through the downward movement of the lifting table 51, the local stretching of the blank 80 can be reduced, which is beneficial to ensuring the wall thickness of the formed blow molded part.

[0138] In a possible implementation manner, the displacement unit 52 includes a guide rail and a slider slidably arranged on the guide rail. The guide rail is arranged in the second direction. The slider is pushed by a telescopic cylinder to slide on the guide rail, and the clamping unit 53 is arranged on the slider. In other possible implementation manners, the displacement unit 52 can also include a lead screw and a nut. The lead screw is arranged in the second direction, and the nut moves along the lead screw, and the clamping unit 53 is arranged on the nut.

[0139] In a possible implementation manner, reference Figure 6 and Figure 7 As shown, the clamping unit 53 includes a first clamping rod 531 and a second clamping rod 532. A clamping cavity 533 for clamping the blank 80 is formed between the first clamping rod 531 and the second clamping rod 532; the lengths of both the first clamping rod 531 and the second clamping rod 532 are greater than or equal to the width of the blank 80.

[0140] The die can be located above the blow molding equipment. The sheet-shaped molten blank that is melted, plasticized by the extruder and extruded from the outlet of the die directly extends between the punch 20 and the die 30. Considering that the blank 80 is relatively soft, the clamping unit 53 clamps the blank 80 along the width direction of the blank 80. The lengths of the first clamping rod 531 and the second clamping rod 532 are relatively long, which can better clamp the blank 80 and prevent the edges of the blank 80 from piling up. The clamping unit 53 clamps the top of the blank 80, and the blank 80 sags due to its own gravity and extends between the punch 20 and the die 30.

[0141] In order to improve the stability of clamping the blank 80, convex teeth are provided on the surface of the first clamping rod 531 facing the clamping cavity 533 and on the surface of the second clamping rod 532 facing the clamping cavity 533, thereby improving the stability of clamping.

[0142] In a possible implementation manner, referring to Figure 2 , Figure 8 and Figure 9 as shown, the male mold 20 includes a main body portion 21, an auxiliary male mold 22, and a telescopic member 23. The auxiliary male mold 22 is movably arranged on the side of the main body portion 21 facing the female mold 30. The auxiliary male mold 22 is connected to the main body portion 21 through the telescopic member 23. And the auxiliary male mold 22 is located in the blow molding cavity. At least one air hole 221 is provided on the surface of the auxiliary male mold 22 facing the female mold 30. The auxiliary male mold 22 is used to push the blank 80 to move along the second direction.

[0143] In order to improve the balance of the movement of the auxiliary male mold 22, the auxiliary male mold 22 and the main body portion 21 can be connected through a plurality of telescopic members 23 arranged at intervals, which can effectively prevent the auxiliary male mold 22 from deflecting, thereby improving the quality of the formed blow molded part.

[0144] In a possible implementation manner, the telescopic member 23 can be a telescopic cylinder.

[0145] In a possible implementation manner, a guide rod is further provided on the side of the auxiliary male mold 22 facing the main body portion 21. The main body portion 21 has a guide hole adapted to the guide rod. The guide rod is inserted into the guide hole to realize the guiding function of the movement of the auxiliary male mold 22.

[0146] In a possible implementation manner, the auxiliary male mold 22 includes a plastic profiling block and a metal fixing plate. The plastic profiling block is connected to the surface of the metal fixing plate facing the female mold 30.

[0147] The auxiliary male mold 22 is used to send the blank 80 to a position close to the inner wall of the cavity of the female mold 30 before the blank 80 is blown up, reducing the excessive local stretching caused by the non-free stretching stage during the blowing process of the blank 80, ensuring the local wall thickness of the blow molded part, and improving the wall thickness uniformity. When the auxiliary male mold 22 moves in the direction close to the blank 80, high-pressure gas is used to blow the blank 80, so that the blank 80 adheres to the inner wall of the female mold 30 in the blow molding cavity.

[0148] Under the action of the auxiliary male mold 22 pushing the blank 80 or supplying gas to blow the blank 80, the blank 80 substantially in a flat plate shape can form a concave cavity recessed into the female mold 30 in the blow molding cavity, improving the structural diversity of the formed blow molded part.

[0149] Referring to Figure 10As shown, the air hole 221 includes a blowing hole which is connected to a blowing device. The blowing device can convey high-pressure air into the blow molding cavity through the air hole 221. The blowing hole includes a pre-blowing hole and a high-pressure blowing hole. The pre-blowing hole can be located near the corner of the blow molded part. The pre-blowing hole is relatively independent of the high-pressure blowing hole, and the pre-blowing hole and the high-pressure blowing hole are distributed at intervals. The air hole 221 further includes a return air hole which is used for discharging the gas in the blow molding cavity.

[0150] Reference Figure 2 As shown, the high-pressure gas output by the air pressure generating device is sent out through the high-pressure blowing hole to blow the blank 80, so that the blank 80 is pressed against the inner wall of the female mold 30. During molding, under the action of the gas, the auxiliary male mold 22 is separated from the blank 80. By adjusting the gas delivery volume, the wall thickness of the blow molded part formed can be adjusted, and it is convenient to adjust the wall thickness of the blow molded part.

[0151] Reference Figure 2 and Figure 11 As shown, the inner wall of the cavity of the female mold 30 further has an exhaust hole 31. The residual air between the blow molded part and the inner wall of the cavity of the female mold 30 can be discharged through this exhaust hole 31, preventing the residual air between the blow molded part and the inner wall of the cavity of the female mold 30, avoiding affecting the fitting effect between the blow molded part and the female mold 30, and improving the quality of the blow molded part formed.

[0152] In a possible implementation manner, there can be multiple air holes 221, and they are evenly distributed on the side of the auxiliary male mold 22 facing the female mold 30. Thus, when the blown air flow pushes the blank 80, the blank 80 can be kept balanced, which is beneficial to improving the uniformity of the wall thickness of the blow molded part formed and improving the quality of the blow molded part.

[0153] In a possible implementation manner, reference Figure 1 As shown, the number of the blow molding assemblies 10 is two, and the male molds 20 of the two blow molding assemblies 10 are connected as a whole and arranged oppositely. Such a structure makes the blow molding device provided by the present invention have a compact structure, and moreover, two blow molded parts can be formed at one time, improving the production efficiency.

[0154] The shapes of the blow molding cavities of the two blow molding assemblies 10 can be the same, so that the two blow molding assemblies 10 can form two blow molded parts with the same shape, realizing double output with one mold and improving the production efficiency. Of course, the shapes of the blow molding cavities of the two blow molding assemblies 10 can also be different, so that the two blow molding assemblies 10 can form two blow molded parts with different shapes, making the use more flexible and convenient.

[0155] In a possible implementation manner, the two blow molding components 10 can be independently controlled by two independent controllers to independently control the movement time, speed, stroke, etc. of the auxiliary male mold 22, so as to increase the means for adjusting the local wall thickness of the blow molded part. It can also be integrally controlled by one controller, and no specific limitation is made here.

[0156] During the molding process, through the cooperation of the loading and unloading component 50 and the material tensioning component 40, the local wall thickness of the blow molded part can be adjusted. Exemplarily, during the process when the male mold 20 and the female mold 30 start to close the mold but have not completely closed the mold, when the loading and unloading component 50 pulls the top of the blank 80 and pulls the blank 80 along the second direction, it can achieve adjusting the wall thickness of the local area at the corner where the side panel 72 and the top panel 71 of the upper half of the blow molded part are connected. At the same time, when the material tensioning component 40 pulls the blank 80 along the second direction, it can achieve adjusting the wall thickness of the local area at the corner where the side panel 72 and the top panel 71 of the lower half of the blow molded part are connected. Wherein, the directions in which the loading and unloading component 50 and the material tensioning component 40 pull the blank 80 to move can be the same or opposite, and no specific limitation is made here.

[0157] In a possible implementation manner, the structures of the two female molds 30 oppositely arranged on the opposite sides of the male mold 20 can be the same, so that the shapes of the two blow molded parts formed by the two female molds 30 are the same. Of course, the structures of the two female molds 30 oppositely arranged on the opposite sides of the male mold 20 can also be different, so that the two female molds 30 can form two blow molded parts with different shapes, which is more flexible and convenient to use.

[0158] In a possible implementation manner, the above-mentioned telescopic cylinder can also be replaced by a telescopic oil cylinder, and the rotary cylinder can also be replaced by a rotary oil cylinder.

[0159] There is a coolant flow inside the female mold 30, and coolant, such as water, flows inside the coolant flow, so as to dissipate heat from the blank 80 that is in contact with the inner wall of the female mold 30. After the blank 80 is cooled and shaped, it is formed into a blow molded part.

[0160] Reference Figure 12 and Figure 13 As shown, for a blow molding device provided by the present invention, by pulling the edge of the blank 80 through the material tensioning component 40, the wrinkles of the blank 80 can be smoothed out, effectively solving the problem of blank 80 accumulation caused by the wrinkles of the blank 80 at the corner position of the flanging 73, thereby preventing the problem of over-thick wall thickness and ensuring that the wall thickness meets the requirements.

[0161] A blow molding device provided by the present invention, reference Figure 14As shown, the loading and unloading assembly 50 always holds the blank 80 and realizes demolding by moving with the blow molded part after molding. In addition, the loading and unloading assembly 50 cooperates with the auxiliary male mold 22 to drive the blank 80 to move in the second direction or in the direction opposite to the second direction before the blank 80 is blown up, reducing the excessive local stretching caused by the non-free stretching stage during the blowing process of the blank 80 and ensuring the wall thickness of the side wall of the blow molded part.

[0162] The actions of the blank tensioning assembly 40 clamping the bottom edge of the blank 80, the loading and unloading assembly 50 driving the blank 80 to move, the auxiliary male mold 22 pushing the blank 80 clamped in the blow molding cavity towards the direction close to the female mold 30, as well as evacuating the gas in the blow molding cavity and conveying gas into the blow molding cavity can all be started when the male mold 20 and the female mold 30 are opened and closed and end within 15 s after the male mold 20 and the female mold 30 are closed in place.

[0163] A blow molding method and blow molding equipment provided by the present invention can achieve double output per mold, with high production efficiency, and the production cycle of a single product can be controlled within 1 minute.

[0164] A blow molding method and blow molding equipment provided by the present invention have the advantages of controllable production process and high production efficiency, and do not require pre-making plates, thus saving the relatively high plate-making cost in the middle.

[0165] The local outlet gap of the die head can be adjusted by the retraction and extension of the die core during the blanking process and the adjustment of the die head screws, so that sheet-shaped molten blanks 80 are respectively extruded from the left outlet and / or the right outlet of the die head to achieve wall thickness adjustment in the transverse / longitudinal direction.

[0166] A blow molding method and blow molding equipment provided by the present invention can optimize the local stretchability of the blank 80 and thus optimize the local wall thickness of the product by adjusting the actions of the blank tensioning assembly 40, the loading and unloading assembly 50, and the auxiliary male mold 22, as well as adjusting the vacuum pumping and high-pressure blowing actions.

[0167] In the description of the present invention, it should be understood that the terms "center", "length", "width", "thickness", "top end", "bottom end", "upper", "lower", "left", "right", "front", "rear", "vertical", "horizontal", "inner", "outer", "axial", "circumferential", etc. indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the indicated position or component must have a specific orientation, be constructed and operated in a specific manner, and thus cannot be construed as a limitation to the present invention.

[0168] In addition, the terms "first" and "second" are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0169] In the present invention, unless otherwise clearly specified and defined, the terms "mounted", "connected", "coupled", "fixed", etc. shall be construed in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection, an electrical connection, or capable of communicating with each other; it may be directly connected, or indirectly connected through an intermediate medium, and may be the internal communication of two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0170] In the present invention, unless otherwise clearly specified and defined, the first feature being "on" or "under" the second feature may include the first and second features being in direct contact, or may include the first and second features not being in direct contact but in contact through additional features therebetween. Moreover, the first feature being "above", "over" and "on top of" the second feature includes the first feature being directly above and obliquely above the second feature, or merely indicating that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature includes the first feature being directly below and obliquely below the second feature, or merely indicating that the first feature has a lower horizontal height than the second feature.

[0171] 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 them. Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features. And these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A blow molding method, characterized in that, Implemented based on a blow molding device, the blow molding device including a male mold (20) and a female mold (30), the method comprising: Clamping the bottom edge of a blank (80) located between the male mold (20) and the female mold (30) and pulling the blank (80) in a first direction so that the wrinkles on the blank (80) are smoothed out; Closing the male mold (20) and the female mold (30) so that part of the blank (80) is located in a blow molding cavity formed by the closing of the male mold (20) and the female mold (30); Conveying gas into the blow molding cavity so that the blank (80) located in the blow molding cavity adheres to the inner wall of the female mold (30).

2. The blow molding method according to claim 1, characterized in that After closing the male mold (20) and the female mold (30) so that part of the blank (80) is located in a blow molding cavity formed by the closing of the male mold (20) and the female mold (30), and before conveying gas into the blow molding cavity so that the blank (80) located in the blow molding cavity adheres to the inner wall of the female mold (30), further comprising: Controlling the movement of an auxiliary male mold (22) of the male mold (20) and pushing the blank (80) clamped between the male mold (20) and the female mold (30) so that the blank (80) moves in a direction closer to the female mold (30).

3. The blow molding method according to claim 1, characterized in that Within a preset time after the female mold (30) starts to move towards the male mold (20) for closing until the female mold (30) is closed with the male mold (20), further comprising: Clamping the top of the blank (80) and pulling part of the blank (80) to move in a second direction; Clamping the bottom edge of the blank (80) and pulling part of the blank (80) to move in the second direction.

4. The blow molding method according to claim 1, characterized in that, Within a preset time after the female mold (30) starts to move towards the male mold (20) for closing until the female mold (30) is closed with the male mold (20), further comprising: Clamping the top of the blank (80) and driving part of the blank (80) to move in a third direction.

5. The blow molding method according to claim 1, characterized in that, After closing the male mold (20) and the female mold (30) so that part of the blank (80) is located in a blow molding cavity formed by the closing of the male mold (20) and the female mold (30), and before conveying gas into the blow molding cavity so that the blank (80) located in the blow molding cavity adheres to the inner wall of the female mold (30), further comprising: Evacuating the air between the cavity of the female mold (30) and the blank (80) so that the blank (80) adheres to the inner wall of the cavity of the female mold (30).

6. A blow molding device, characterized in that, For implementing the blow molding method according to any one of claims 1-5, the blow molding device comprises: At least one blow molding assembly (10), the blow molding assembly (10) comprising a punch (20) and a die (30) cooperating with the punch (20), the punch (20) and the die (30) being combined to form a blow molding cavity, the punch (20) being configured to blow a blank (80) located within the blow molding cavity so that the blank (80) conforms to the inner wall of the die (30) within the blow molding cavity; At least two blank tensioning assemblies (40), the blank tensioning assemblies (40) being configured to grip the edge of the blank (80) located between the punch (20) and the die (30) and drive the blank (80) to move, so as to reduce wrinkles of the blank (80).

7. The blow molding apparatus according to claim 6, characterized in that The blank tensioning assembly (40) comprises a mounting base (41), a gripper unit (42) and a moving unit (43), the moving unit (43) being connected to the die (30), the gripper unit (42) being arranged on the mounting base (41), the moving unit (43) being used to drive the mounting base (41) to move along a first direction and / or a second direction, wherein the first direction is a direction away from the center of the blank (80), and the second direction is the same as or opposite to the mold closing direction of the punch (20) and the die (30).

8. The blow molding device according to claim 7, wherein, The gripper unit (42) comprises a first jaw (421), a second jaw (422) and a first driving member (423), both the first jaw (421) and the first driving member (423) being connected to the mounting base (41), the first driving member (423) comprising a rotatably arranged rotating shaft, the second jaw (422) being connected to the rotating shaft, the first driving member (423) being used to drive the second jaw (422) to switch between a state of closing with the first jaw (421) and a state of separating from the first jaw (421).

9. The blow molding apparatus according to claim 7, characterized in that, The moving unit (43) comprises: a second driving member (431) and a third driving member (432), the third driving member (432) being connected to the mounting base (41), the second driving member (431) being connected to the die (30), the second driving member (431) being used to drive the mounting base (41) to move along a direction the same as or opposite to the first direction, and the third driving member (432) being used to drive the mounting base (41) to move along the second direction.

10. The blow molding device according to any one of claims 7-9, characterized in that, It further comprises a loading and unloading assembly (50), the loading and unloading assembly (50) comprising a lifting platform (51), at least one displacement unit (52) and at least one clamping unit (53), the displacement unit (52) being arranged between the lifting platform (51) and the clamping unit (53), the lifting platform (51) being configured to enable the clamping unit (53) to move along a third direction, the clamping unit (53) being located above the blow molding assembly (10), the clamping unit (53) being used to clamp the top of the blank (80), and the displacement unit (52) being used to drive the clamping unit (53) to move along the second direction.

11. The blow molding device according to claim 10, characterized in that, The clamping unit (53) includes a first clamping rod (531) and a second clamping rod (532), and a clamping cavity (533) for clamping the blank (80) is formed between the first clamping rod (531) and the second clamping rod (532); The lengths of the first clamping rod (531) and the second clamping rod (532) are both greater than or equal to the width of the blank (80).

12. The blow molding apparatus according to any one of claims 7-9, characterized in that The male mold (20) includes a main body portion (21), an auxiliary male mold (22) and a telescopic member (23). The auxiliary male mold (22) is movably arranged on a side of the main body portion (21) facing the female mold (30). The auxiliary male mold (22) is connected to the main body portion (21) through the telescopic member (23), and the auxiliary male mold (22) is located in the blow molding cavity. At least one air hole (221) is formed on a surface of the auxiliary male mold (22) facing the female mold (30). The auxiliary male mold (22) is used to push the blank (80) to move along the second direction.

13. The blow molding device according to any one of claims 6-9, characterized in that, The number of the blow molding assemblies (10) is two, and the male molds (20) of the two blow molding assemblies (10) are connected as a whole and arranged oppositely.

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