Energy-saving heating device of injection molding machine

Abstract

The utility model relates to an energy-saving heating device of an injection molding machine, which comprises a charging barrel, a plurality of annular heating mechanisms are axially sleeved on the charging barrel at equal intervals, each heating mechanism comprises an electric heating component which is in half-and-half clamping connection, the end face of each electric heating component is axially and symmetrically provided with a shaft seal cover matched with the electric heating component in a limiting and sealing manner, and the shaft seal covers are respectively provided with a plurality of annular grooves. The two shaft seal covers are connected in a fastened mode through a plurality of long-rod bolts which are arranged at intervals in the circumferential direction. According to the utility model, the two shaft seal covers form an axially symmetrical limiting seal cover structure on the end face of the electric heating assembly, so that the exposed heat dissipation gap on the end face of the traditional heating ring is completely sealed; due to the double-end-face closed design, heat loss can be reduced, and the energy consumption index of unit yield is remarkably reduced.

Description

Technical Field

[0001] This utility model belongs to the technical field of injection molding heating materials, and specifically relates to an energy-saving heating device for injection molding machines. Background Technology

[0002] Currently, injection molding machines mainly achieve material plasticization through a combination of electric heating and frictional heating. Multiple heating coils are axially spaced around the outside of the barrel, and the temperature is raised to a set value through resistance heating, causing the internal plastic particles to melt. When the screw rotates inside the barrel, it generates auxiliary heat through friction with the material, which improves plasticization efficiency.

[0003] Existing heating coils are generally composed of an inner heating layer and an outer protective shell axially connected. However, since the end face of the heating layer is not covered, some heat is easily lost, resulting in energy loss.

[0004] Therefore, we provide an energy-saving heating device for injection molding machines to solve the above-mentioned technical problems. Utility Model Content

[0005] This utility model addresses the shortcomings of existing technologies by providing an energy-saving heating device for injection molding machines. The specific technical solution is as follows:

[0006] This utility model provides an energy-saving heating device for an injection molding machine, including a barrel. Multiple annular heating mechanisms are axially and equally spaced on the barrel. Each heating mechanism includes a half-clamped electric heating component. Each electric heating component has an axially symmetrically limited and sealed end face with a matching shaft seal cover. Two shaft seal covers are fastened together by multiple long bolts arranged circumferentially.

[0007] As a preferred embodiment of this utility model, the electric heating component includes a semi-circular arc-shaped electric heating layer, and the inner diameter of the electric heating layer is the same as the outer diameter of the barrel; a protective shell is attached to the outer wall of the electric heating layer, and a junction box electrically connected to the electric heating layer is provided on the outer wall of the protective shell.

[0008] As a preferred embodiment of this utility model, the heating layer includes heating wires arranged in a semi-circular pattern. Ceramic plates are radially attached to both sides of the heating wires. The inner diameter of the inner ceramic plate is the same as the outer diameter of the barrel. The wires in the junction box pass through the protective shell and the outer ceramic plate and are electrically connected to the heating wires.

[0009] As a preferred technical solution of this utility model, the two ceramic plate end faces of the electric heating layer are respectively radially fixed and symmetrically connected with heat-resistant adhesive plates that are adapted to them. The end faces of the heat-resistant adhesive plates are flush with the corresponding end faces of the protective shell, and the heat-resistant adhesive plates on the outer side are connected to the inner wall of the protective shell by screws.

[0010] As a preferred technical solution of this utility model, the shaft seal cover includes a cover plate with a semi-circular arc structure. The inner diameter of the cover plate is the same as the outer diameter of the material cylinder. An arc-shaped limiting block is vertically connected to the inner end face of the cover plate. The limiting block is axially inserted into a limiting groove opened on the corresponding end face of the protective shell. The outer edges of the cover plates of the two shaft seal covers are fastened together by a plurality of long bolts arranged circumferentially.

[0011] As a preferred embodiment of this utility model, the inner side of the outer edge of the cover plate is vertically connected with a matching protrusion plate, the inner diameter of the protrusion plate being the same as the outer diameter of the material cylinder; the long bolt passes through the protrusion plate.

[0012] As a preferred embodiment of the present invention, one of the protective shell end faces of the electric heating component is radially symmetrically connected with T-shaped inserts, and the other electric heating component has radially symmetrical slots on its protective shell end face, and the slots are axially inserted into the corresponding inserts.

[0013] The beneficial effects of this utility model are:

[0014] 1. This utility model completely seals the heat dissipation gap exposed on the end face of the traditional heating coil by forming an axially symmetrical limiting sealing structure with two shaft seals on the end face of the heating element; this double-end-face sealing design can reduce heat loss and significantly reduce the energy consumption index per unit output.

[0015] 2. The half-clamping design of the electric heating component in this utility model, combined with the axial positioning structure, can achieve better assembly accuracy. Compared with the traditional hinge-clamp structure of the split heating coil, this structure improves the fit between the heating surface and the barrel, effectively improving the heat transfer efficiency.

[0016] 3. The circumferentially distributed design of the long rod bolts in this utility model forms a symmetrical constraint force field, which reduces the circumferential stress generated by the heating mechanism during thermal cycling; combined with the limiting effect of the shaft seal cover, it can control the amount of thermal deformation and extend the service life of the electric heating component. Attached Figure Description

[0017] Figure 1 A schematic diagram of the overall structure of this utility model is shown;

[0018] Figure 2 A three-dimensional structural schematic diagram of the heating mechanism in this utility model is shown;

[0019] Figure 3 A partially exploded structural diagram of the heating mechanism in this utility model is shown;

[0020] Figure 4 A partial three-dimensional structural schematic diagram (I) of the heating mechanism in this utility model is shown;

[0021] Figure 5 A partial three-dimensional structural schematic diagram (II) of the heating mechanism in this utility model is shown;

[0022] Figure 6 A three-dimensional structural diagram of the heating mechanism of this utility model without the shaft seal cover is shown.

[0023] The figure shows: 1. Material cylinder; 2. Heating mechanism; 21. Electric heating component; 211. Electric heating layer; 2111. Electric heating wire; 2112. Ceramic plate; 212. Protective shell; 2121. Limiting groove; 2122. Insert block; 2123. Slot; 213. Junction box; 214. Heat-resistant rubber sheet; 22. Shaft seal cover; 221. Cover plate; 222. Protruding plate; 223. Limiting block; 23. Long bolt. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this utility model clearer, the following detailed description is provided in conjunction with embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this utility model.

[0025] Example 1

[0026] To address the technical problems in the background section, the following energy-saving heating device for injection molding machines is provided:

[0027] Combination Figure 1 and Figure 2 As shown, an energy-saving heating device for an injection molding machine includes a barrel 1. Multiple annular heating mechanisms 2 are axially spaced on the barrel 1. Each heating mechanism 2 includes a half-clamped electric heating component 21. Each end face of the electric heating component 21 is axially symmetrically limited and sealed with a matching shaft seal cover 22. Two shaft seal covers 22 are fastened together by multiple long bolts 23 arranged circumferentially.

[0028] By adopting the above technical solution, the energy-saving heating device completely seals the heat dissipation gap exposed on the end face of the traditional heating coil by forming an axially symmetrical limiting sealing structure on the end face of the electric heating component 21 through two shaft sealing covers 22; this double-end-face sealing design can reduce heat loss and significantly reduce the energy consumption index per unit output.

[0029] The split-fit design of the electric heating component 21 in this energy-saving heating device, combined with the axial positioning structure, can achieve better assembly accuracy. Compared with the traditional hinge-snap structure split heating coil, this structure improves the fit between the heating surface and the barrel 1, effectively improving the heat transfer efficiency.

[0030] The circumferentially distributed design of the long bolts 23 in this energy-saving heating device forms a symmetrical constraint force field, which reduces the circumferential stress generated by the heating mechanism 2 during thermal cycling. Combined with the limiting effect of the shaft seal cover 22, the amount of thermal deformation can be controlled, thereby extending the service life of the electric heating component 21.

[0031] Example 2

[0032] Combination Figures 3-6 As shown, based on the above embodiments, this embodiment further provides the following:

[0033] In this embodiment, as Figure 3 As shown, the electric heating assembly 21 includes a semi-circular arc-shaped electric heating layer 211, and the inner diameter of the electric heating layer 211 is the same as the outer diameter of the barrel 1; a protective shell 212 is attached to the outer wall of the electric heating layer 211, and a junction box 213 electrically connected to the electric heating layer 211 is provided on the outer wall of the protective shell 212.

[0034] like Figure 3 As shown, the heating layer 211 includes heating wires 2111 arranged in a semi-circular shape. Ceramic plates 2112 are radially attached to both sides of the heating wires 2111. The inner diameter of the ceramic plate 2112 is the same as the outer diameter of the barrel 1. The wires in the junction box 213 pass through the protective shell 212 and the outer ceramic plate 2112 and are electrically connected to the heating wires 2111.

[0035] By adopting the above technical solution, the heating layer 211 adopts a semi-circular arc structure, the inner diameter of which matches the outer diameter of the barrel 1, and the heating wire 2111 is clamped on the inner and outer sides by radially attached ceramic plates 2112. The inner ceramic plate 2112 is in direct contact with the outer wall of the barrel 1, and its thermal conductivity is higher than that of traditional mica sheets, which improves the heat conduction efficiency to the barrel 1 and effectively reduces lateral heat diffusion; the outer ceramic plate 2112 and the protective shell 212 form an insulating layer to prevent the heating wire 2111 from directly contacting the protective shell 212 (preferably, the protective shell is made of stainless steel) and causing a short circuit; the semi-circularly arranged heating wire 2111 forms a continuous annular heating surface under the constraint of the ceramic plate 2112, which effectively reduces axial temperature fluctuation and improves melting uniformity.

[0036] The protective shell 212 covers the outer wall of the heating layer 211, and the junction box 213 is integrated into the outer surface of the protective shell 212. The wires pass through the multi-layer structure and are directly connected to the heating wire 2111. When the protective shell 212 is made of stainless steel, its impact resistance is improved. When the wires pass through the protective shell 212 and the outer ceramic plate 2112, a high-temperature silicone sealing ring (temperature resistance ≥300℃) is used to avoid the risk of leakage. The external design of the junction box 213 means that the entire heating mechanism 2 does not need to be disassembled when replacing the heating wire 2111, thus shortening the maintenance time.

[0037] After the electric heating element 21 is snapped in half, the inner ceramic plate 2112 and the barrel 1 form a continuous annular contact surface. The difference in thermal expansion coefficient between the ceramic plate 2112 and the steel barrel 1 creates a gradient expansion, which increases the contact pressure at high temperatures and avoids an increase in thermal resistance. The half-spinning structure transforms the circumferential tensile stress of the traditional heating coil into compressive stress, effectively improving fatigue life.

[0038] like Figure 3 As shown, the two ceramic plates 2112 of the heating layer 211 are respectively radially fixed and symmetrically connected with heat-resistant adhesive plates 214 that are adapted to them. The end face of the heat-resistant adhesive plate 214 is flush with the corresponding end face of the protective shell 212, and the heat-resistant adhesive plate 214 on the outer side is connected to the inner wall of the protective shell 212 by screws.

[0039] By adopting the above technical solution, the heat-resistant adhesive plate 214 is radially and symmetrically fixed to both ends of the ceramic plate 2112, with its end face flush with the end face of the protective shell 212. The outer side is connected by screws (not shown in the figure). The heat-resistant adhesive plate 214 fills the axial gap between the ceramic plate 2112 and the protective shell 212, forming a continuous sealing layer. This reduces the heat flux density at the end face compared to traditional structures, minimizing heat loss. The outer heat-resistant adhesive plate 214 is connected to the protective shell 212 by screws, and pre-drilled positioning holes in the heat-resistant adhesive plate 214 allow for a detachable connection between the heating layer 211 and the protective shell 212, facilitating the replacement of damaged heating layer 211. The flush design between the end face of the heat-resistant adhesive plate 214 and the corresponding end face of the protective shell 212 allows the shaft seal cover 22 to adhere to the heat-resistant adhesive plate 214, further improving the sealing and insulation effect.

[0040] The heat-resistant rubber sheet 214 is preferably made of silicone rubber (temperature resistance ≥300℃). The difference in thermal expansion between the ceramic plate 2112 and the steel protective shell 212 is absorbed by the flexibility of the heat-resistant rubber sheet 214, reducing the peak value of the interface stress. The elastic deformation of the heat-resistant rubber sheet 214 can absorb the vibration energy caused by the screw rotation, reducing the amplitude of the heating wire 2111 and extending the life of the heating wire. The heat-resistant rubber sheet 214 has a smaller compression set at 300℃ than traditional rubber, ensuring long-term sealing stability.

[0041] like Figure 3 and Figure 6 As shown, the shaft seal cover 22 includes a cover plate 221 with a semi-circular arc structure. The inner diameter of the cover plate 221 is the same as the outer diameter of the material cylinder 1. An arc-shaped limiting block 223 is vertically connected to the inner end face of the cover plate 221. The limiting block 223 is axially inserted into the limiting groove 2121 opened on the corresponding end face of the protective shell 212. The outer edges of the cover plates 221 of the two shaft seal covers 22 are fastened together by a plurality of long bolts 23 arranged circumferentially.

[0042] By adopting the above technical solution, the arc-shaped limiting block 223 vertically connected to the inner end face of the cover plate 221 is axially inserted into the limiting groove 2121 on the end face of the protective shell 212. The cooperation between the limiting block 223 and the limiting groove 2121 ensures that the sealing surface completely covers the end face of the electric heating component 21, effectively reducing the end face heat leakage rate; the arc-shaped limiting block 223 can withstand circumferential shear force, avoiding the displacement of the sealing surface caused by the rotation vibration of the screw, thus extending the sealing life; the insertion guide structure shortens the assembly time and reduces the time spent on manual adjustment.

[0043] The outer edges of the two cover plates 221 are subjected to axial preload through multiple circumferentially distributed long bolts 23, forming a continuous annular compression sealing band. The cover plates 221 and the protective shell 212 are connected by a non-welded plug-in connection. After the long bolts 23 are removed, the cover plates 221 can be completely removed, reducing maintenance costs.

[0044] like Figures 3-5 As shown, the cover plate 221 has an integrally vertically connected protruding plate 222 on the inner side of its outer edge, and the inner diameter of the protruding plate 222 is the same as the outer diameter of the material cylinder 1; the long bolt 23 passes through the protruding plate 222.

[0045] By adopting the above technical solution, the convex plate 222 and the cover plate 221 are connected vertically in an integrated manner. The integrated structure increases the moment of inertia of the cover plate 221 section and reduces the axial bending deformation under high temperature conditions. The convex plate 222 serves as the direct bearing surface of the bolt force, which improves the uniformity of the preload distribution and reduces the pressure fluctuation range of the sealing surface.

[0046] The inner diameter of the convex plate 222 is the same as the outer diameter of the barrel 1, which can increase the radial limiting effect on the electric heating component 21; the radial cross-sectional area of ​​the convex plate 222 is increased, forming a heat flow bottleneck, which reduces the axial heat conduction loss; the structure of the convex plate 222 increases the effective clamping length of a single bolt, and improves the preload transmission efficiency.

[0047] like Figures 3-6 As shown, one of the heating components 21 has T-shaped inserts 2122 radially symmetrically connected to the end face of the protective shell 212, and the other heating component 21 has slots 2123 radially symmetrically opened on the end face of the protective shell 212, and the slots 2123 are axially inserted into the corresponding inserts 2122.

[0048] By adopting the above technical solution, the T-shaped insert 2122 and the slot 2123 are axially inserted and matched. The insertion guide makes the two halves of the electric heating component 21 radially fixed and the center deviation is reduced. The accuracy is improved compared with the traditional hinge-snap structure, ensuring that the contact area between the ceramic plate 2112 and the barrel 1 is increased.

[0049] Preferably, the inner wall of the slot 2123 is pre-set with an annular sealing groove and an embedded silicon-carbon composite sealing strip. After the insert block 2122 is inserted, a three-level seal is formed, which effectively improves the airtightness compared with the traditional snap-fit ​​connection.

[0050] Working principle and usage process of this utility model:

[0051] In use, the present invention first aligns the two semi-circular arc-shaped electric heating components 21 along the axial direction of the barrel 1, and then axially inserts the T-shaped insert 2122 on the end face of the protective shell 212 into the corresponding slot 2123 to form a complete annular structure. The insertion and engagement of the insert 2122 and the slot 2123 achieves accurate radial positioning. Subsequently, the limiting block 223 of the shaft seal cover 22 is inserted into the limiting groove 2121 of the protective shell 212, and multiple circumferentially distributed long bolts 23 penetrate the protrusion 222 to apply axial preload, forming a continuous annular sealing surface.

[0052] Then, the heating wire 2111 is energized through the junction box 213, and the current generates resistance heat through the semi-circular arrangement of the heating wire. The heat is efficiently conducted to the barrel 1 through the inner ceramic plate 2112, and the friction generated by the rotation of the screw inside the barrel 1 melts the plastic particles. The outer ceramic plate and the protective shell 212 form a heat insulation barrier. The heat-resistant rubber plate 214 is pressed onto the end face of the ceramic plate 2112 with screws to fill the gap of the protective shell 212 and block the axial heat leakage path. The outer heat-resistant rubber plate 214 is then connected to the protective shell 212 with screws, which can ensure the detachable connection between the heating layer 211 and the protective shell 212, which is convenient for later maintenance and replacement.

[0053] Finally, when the heating element 21 needs to be replaced, after removing the long rod bolt 23, the two halves of the heating mechanism 2 can be separated by pulling out the plug 2122 in the opposite direction; the modular design effectively shortens the maintenance time.

[0054] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. An energy saving heating device for an injection molding machine comprising a barrel (1), characterized in that: The material cylinder (1) is axially and equally spaced with multiple annular heating mechanisms (2). The heating mechanism (2) includes a half-clamped electric heating component (21). Each electric heating component (21) has an axially symmetrically limited and sealed end face with a matching shaft seal cover (22). The two shaft seal covers (22) are fastened together by multiple long bolts (23) arranged circumferentially.

2. The energy-saving heating device of an injection molding machine according to claim 1, characterized in that: The electric heating assembly (21) includes a semi-circular arc-shaped electric heating layer (211), and the inner diameter of the electric heating layer (211) is the same as the outer diameter of the barrel (1); a protective shell (212) is attached to the outer wall of the electric heating layer (211), and a junction box (213) electrically connected to the electric heating layer (211) is provided on the outer wall of the protective shell (212).

3. The energy-saving heating device of an injection molding machine according to claim 2, characterized in that: The heating layer (211) includes heating wires (2111) arranged in a semi-circular shape. Ceramic plates (2112) are radially attached to both sides of the heating wires (2111). The inner diameter of the ceramic plate (2112) is the same as the outer diameter of the barrel (1). The wires in the junction box (213) pass through the protective shell (212) and the ceramic plate (2112) on the outer side and are electrically connected to the heating wires (2111).

4. The energy-saving heating device of an injection molding machine according to claim 3, characterized in that: The two ceramic plates (2112) of the heating layer (211) are respectively radially fixed and symmetrically connected with heat-resistant adhesive plates (214) that are adapted to them. The end face of the heat-resistant adhesive plate (214) is flush with the corresponding end face of the protective shell (212), and the heat-resistant adhesive plate (214) on the outside is connected to the inner wall of the protective shell (212) by screws.

5. The energy saving heating device of an injection molding machine according to claim 2, wherein: The shaft seal cover (22) includes a cover plate (221) with a semi-circular arc structure. The inner diameter of the cover plate (221) is the same as the outer diameter of the material cylinder (1). An arc-shaped limiting block (223) is vertically connected to the inner end face of the cover plate (221). The limiting block (223) is axially inserted into the limiting groove (2121) opened on the corresponding end face of the protective shell (212). The outer edges of the cover plates (221) of the two shaft seal covers (22) are fastened together by a plurality of long bolts (23) arranged circumferentially.

6. The energy-saving heating device of an injection molding machine according to claim 5, characterized in that: The cover plate (221) has an integral vertical connection to the inner side of the outer edge with a corresponding protruding plate (222), the inner diameter of the protruding plate (222) being the same as the outer diameter of the material cylinder (1); the long bolt (23) passes through the protruding plate (222).

7. The energy-saving heating device of an injection molding machine according to claim 2, characterized in that: One of the heating components (21) has T-shaped inserts (2122) radially symmetrically connected to the end face of the protective shell (212) of the other heating component (21), and slots (2123) are radially symmetrically opened on the end face of the protective shell (212) of the other heating component (21), and the slots (2123) are axially inserted into the corresponding inserts (2122).

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