Self-sealing type hot runner structure

Abstract

The utility model belongs to the technical field of injection molding, and particularly relates to a self-sealing type hot runner structure which comprises a hot runner body, a hot runner is arranged in the hot runner body, one end of the hot runner is communicated with a nozzle of an injection molding machine, the other end of the hot runner is provided with a sprue gate, a spreader and an elastic piece are arranged in the hot runner, and a valve rod is arranged on the spreader in a sliding mode. A plug is arranged at one end, far away from the spreader, of the valve rod, and opens the sprue gate under the elastic action of the elastic piece during injection molding; and when injection molding is completed, the plug overcomes the elasticity of the elastic piece under the action of pressure to plug the sprue gate. The cost of parts is low, the valve rod is short, machining is convenient, and the machining cost is low; and the molten plastic cannot impact the valve rod frontally, so that the property change of the plastic cannot be caused, and the product quality is good.

Description

Technical field:

[0001] The utility model belongs to the technical field of injection molding, in particular to a self-sealing hot runner structure. Background technology:

[0002] A hot runner is a heating component system used in an injection mold to inject molten plastic particles into the mold cavity.

[0003] The Chinese utility model patent (publication number CN219667325U, application date 2023.02.09, publication date 2023.09.12) discloses a needle valve hot runner assembly, including a diverter plate, a hot nozzle, a valve needle and a valve needle sleeve, wherein the diverter plate is connected to the hot nozzle to form a hot runner located in the diverter plate and the hot nozzle, the valve needle is inserted into the diverter plate and at least partially located in the hot runner, the valve needle sleeve is sleeved on the portion of the valve needle located in the hot runner, and the valve needle can be driven to move axially so that the portion located in the hot runner protrudes out of the valve needle sleeve to close the liquid outlet of the hot runner or is received in the valve needle sleeve to open the liquid outlet. The hot runner includes a diverter channel located in the diverter plate and an injection channel located in the hot nozzle and connected to the diverter channel, and the liquid outlet is formed at one end of the injection channel away from the diverter channel. A mounting groove is provided on the side of the diverter plate facing away from the hot nozzle, corresponding to the needle sleeve opening, and the valve needle sleeve is inserted into the bottom wall of the mounting groove. The needle valve hot runner assembly also includes a cylinder connected to one end of the valve needle protruding from the diverter plate, and the cylinder is connected to the valve needle to drive the valve needle to move along its axial direction. A cylinder gasket is also connected between the cylinder and the diverter plate, and the cylinder gasket can abut on the end surface of the side wall of the mounting groove, and abut against the cylinder and the separation plate respectively, so that the reaction force of the cylinder on the cylinder gasket acts on the diverter plate, so that the separation plate and the hot nozzle fit more closely.

[0004] The shortcomings of the above-mentioned needle valve hot runner assembly are: 1. The valve needle is driven to move along its axial direction by a cylinder arranged at one end of the valve needle protruding from the diverter plate, and the cost of parts is high. In addition, the valve needle passes through the hot nozzle, the valve needle is relatively long, and it is not convenient to process, and the processing cost is high; 2. When the molten plastic enters the injection channel through the diverter channel, it directly impacts the valve needle sleeve, which will cause the properties of the plastic to change and degrade, thereby causing quality problems such as uneven product surface, affecting product quality. Summary of the invention:

[0005] The utility model aims to provide a self-sealing hot runner structure, which has low component cost and a short valve stem, is easy to process and has low processing cost; and the molten plastic will not directly impact the valve stem, thereby not causing changes in the properties of the plastic and having good product quality.

[0006] The utility model is achieved in this way:

[0007] A self-sealing hot runner structure comprises a hot runner body, wherein a hot runner is arranged in the hot runner body, one end of the hot runner is connected to the nozzle of an injection molding machine, and the other end is provided with a pouring port, a diverter shuttle and an elastic member are arranged in the hot runner, a valve stem is slidably arranged on the diverter shuttle, and a plug is arranged at one end of the valve stem away from the diverter shuttle. During injection molding, the plug opens the pouring port under the elastic force of the elastic member; when injection molding is completed, the plug overcomes the elastic force of the elastic member under the action of pressure to seal the pouring port.

[0008] In the above-mentioned self-sealing hot runner structure, the valve stem includes a sliding rod portion with one end slidably arranged in the diverter shuttle, and a connecting rod connecting the sliding rod portion and the plug. The connecting rod is slidably arranged in the pouring gate, and a gap is left between the connecting rod and the pouring gate to form a liquid outlet channel. During injection molding, one end of the connecting rod connected to the plug extends out of the pouring gate, and liquid is discharged through the liquid outlet channel; when the injection molding is completed, the plug is located in the pouring gate and blocks the pouring gate.

[0009] In the above-mentioned self-sealing hot runner structure, the sliding rod portion, the connecting rod and the plug are an integrated structure.

[0010] In the above-mentioned self-sealing hot runner structure, the setting position of the plug can also be: the plug and the elastic part are both arranged in the hot runner, and the elastic part is a spring arranged between the valve stem and the hot runner body. During injection molding, the elastic force of the spring makes the plug move away from the pouring gate; when the injection molding is completed, the plug compresses the spring under the action of pressure and moves toward the pouring gate until the pouring gate is blocked.

[0011] In the above-mentioned self-sealing hot runner structure, the pouring port is a cylindrical through hole, the sliding rod part is a cylindrical rod, and the diameter of the sliding rod part is larger than the diameter of the pouring port, and an outlet notch connected to the liquid outlet channel is provided on the outer periphery of one end of the sliding rod part close to the connecting rod.

[0012] In the above-mentioned self-sealing hot runner structure, a plurality of liquid outlet notches are evenly distributed around the circumference.

[0013] In the above-mentioned self-sealing hot runner structure, the end face of the sliding rod portion close to the connecting rod is a frustum surface one whose diameter gradually decreases toward the connecting rod side, and the hot runner includes a frustum hole one connected to the pouring port, and the taper of the frustum hole one is adapted to the taper of the frustum surface one.

[0014] In the above-mentioned self-sealing hot runner structure, the hot runner also includes cylindrical hole one, truncated cone hole two and cylindrical hole two which are connected in sequence to the truncated cone hole one, the diameter of cylindrical hole two is larger than the diameter of cylindrical hole one, cylindrical hole one is connected to the truncated cone hole one, and the diameter of cylindrical hole one is equal to the maximum diameter of the truncated cone hole one.

[0015] In the above-mentioned self-sealing hot runner structure, the plug is cylindrical, and the end surface of the plug close to the connecting rod is a frustum surface 2 whose diameter gradually decreases toward the connecting rod side.

[0016] In the above-mentioned self-sealing hot runner structure, the elastic member is a compression spring arranged between the slide rod portion and the diverter shuttle, and a spring installation cavity for installing the compression spring is formed in the diverter shuttle.

[0017] In the above-mentioned self-sealing hot runner structure, a guide column is provided at one end of the sliding rod portion away from the connecting rod, and the compression spring is sleeved on the guide column.

[0018] In the above-mentioned self-sealing hot runner structure, the sliding rod portion and the guide column are an integrated structure.

[0019] In the above-mentioned self-sealing hot runner structure, the elastic member may also be: the elastic member is a tension spring, one end of the tension spring is connected to the sliding rod part, and the other end is connected to the hot runner body.

[0020] In the above-mentioned self-sealing hot runner structure, the hot runner body includes a runner body and a heating sleeve mounted outside the runner body, the hot runner is arranged in the runner body, the runner body includes a feed sleeve, a mounting seat and a runner sleeve connected in sequence, the diverter shuttle is fixed to the mounting seat by a connecting strip, an air outlet gap is left between the feed sleeve and the runner sleeve, and an air outlet channel connecting the spring mounting cavity and the air outlet gap is arranged on the diverter shuttle, the connecting strip and the mounting seat.

[0021] In the above-mentioned self-sealing hot runner structure, the diverter shuttle, the connecting strip and the mounting seat are an integrated structure.

[0022] In the above-mentioned self-sealing hot runner structure, the feed sleeve is connected to the mounting seat by threads, the mounting seat and the runner sleeve are connected by threads, the heating sleeve is tightly sleeved outside the runner body, and the heating sleeve is provided with a vent groove connecting the air outlet gap with the outside.

[0023] In the above-mentioned self-sealing hot runner structure, a positioning boss is provided on the periphery of the mounting seat, the feed sleeve and the mounting seat are positioned by the outer peripheral surface of the positioning boss, and the runner sleeve and the mounting seat are positioned by the outer peripheral surface of the positioning boss.

[0024] In the above-mentioned self-sealing hot runner structure, the air outlet gap may be connected to the outside in the following manner: a gap connecting the air outlet gap and the outside is provided between the heating sleeve and the runner body.

[0025] In the above-mentioned self-sealing hot runner structure, the end of the diverter shuttle away from the pouring port is pointed, and the outer periphery is an arc-shaped guide surface, and the connecting strip is a shuttle shape with pointed ends and a wide middle.

[0026] The outstanding advantages of the utility model compared with the prior art are:

[0027] 1. The utility model opens the pouring port by the elasticity of the elastic part and seals the pouring port by pressure, does not require cylinder drive, has low parts cost, and has a short valve stem, which is easy to process and has low processing cost; and the molten plastic will not directly impact the valve stem, thus not causing changes in the properties of the plastic, and has good product quality;

[0028] 2. The valve stem of the utility model includes a sliding rod part with one end slidably arranged in the diverter shuttle, and a connecting rod connecting the sliding rod part and the plug. The connecting rod is slidably arranged in the pouring port, and a gap is left between the connecting rod and the pouring port to form a liquid outlet channel. During injection molding, one end of the connecting rod connected to the plug extends out of the pouring port, and liquid is discharged through the liquid outlet channel; when the injection molding is completed, the plug is located in the pouring port and blocks the pouring port. The structure is simple and easy to install. Description of the drawings:

[0029] Figure 1 It is a three-dimensional diagram of the utility model;

[0030] Figure 2 It is a cross-sectional view of the pouring port of the utility model in an open state;

[0031] Figure 3 It is a cross-sectional view of the utility model in a pouring port blocking state;

[0032] Figure 4 It is an exploded view of the utility model;

[0033] Figure 5 It is a stereoscopic diagram of the mounting seat, the connecting strip and the diverter shuttle of the utility model;

[0034] Figure 6 It is a stereoscopic diagram of the valve stem and the plug of the utility model.

[0035] Figure numerals: 1, hot runner body; 1a, runner body; 1a1, feed sleeve; 1a2, mounting seat; 1a3, runner sleeve; 1b, heating sleeve; 2, hot runner; 2a, truncated cone hole one; 2b, cylindrical hole one; 2c, truncated cone hole two; 2d, cylindrical hole two; 3, pouring gate; 4, diverter shuttle; 5, valve stem; 5a, sliding rod; 5b, connecting rod; 5c, guide column; 6, plug; 7, liquid outlet gap; 8, truncated cone surface one; 9, truncated cone surface two; 10, compression spring; 11, spring mounting cavity; 12, connecting strip; 13, air outlet gap; 14, air outlet channel. Specific implementation method:

[0036] The present invention is further described below with reference to specific embodiments. Figure 1 —6:

[0037] A self-sealing hot runner structure comprises a hot runner body 1, wherein a hot runner 2 is arranged inside the hot runner body 1, wherein one end of the hot runner 2 is connected to the nozzle of an injection molding machine and the other end is provided with a pouring port 3, wherein a diverter shuttle 4 and an elastic member are arranged inside the hot runner 2, wherein a valve stem 5 is slidably arranged on the diverter shuttle 4, and a plug 6 is arranged at one end of the valve stem 5 away from the diverter shuttle 4, during injection molding, the plug 6 opens the pouring port 3 under the elastic force of the elastic member; when injection molding is completed, the plug 6 overcomes the elastic force of the elastic member under the action of pressure to seal the pouring port 3.

[0038] The working principle of the utility model: during injection molding, Figure 1 , 2 As shown, the injection molding machine nozzle injects molten plastic into the hot runner 2, and the molten plastic flows into the cavity through the pouring gate 3. When the injection molding is completed, the cavity is full of plastic, and the molten plastic has nowhere to go. The pressure in the cavity and the hot runner 2 causes the plug 6 to overcome the elastic force of the elastic member to seal the pouring gate 3, disconnecting the pouring gate 3 from the cavity, as shown in FIG. Figure 3 As shown, injection molding is completed.

[0039] like Figure 1-6 As shown, the utility model opens the pouring port by the elasticity of the elastic member and seals the pouring port 3 by pressure, does not require cylinder drive, has low component cost, and the valve stem 5 is short, which is convenient for processing and has low processing cost; and the molten plastic will not directly impact the valve stem 5, thereby not causing changes in the properties of the plastic, and has good product quality.

[0040] During the injection molding, the utility model has fast liquid discharge and automatically blocks the pouring port 3 after the injection molding is completed, which is simple and convenient.

[0041] The structure of the valve stem 5: the valve stem 5 comprises a sliding rod portion 5a with one end slidably arranged in the diverter shuttle 4, and a connecting rod 5b connecting the sliding rod portion 5a and the plug 6. The connecting rod 5b is slidably arranged in the pouring port 3, and a gap is left between the connecting rod 5b and the pouring port 3 to form a liquid outlet channel. During injection molding, one end of the connecting rod 5b connected to the plug 6 extends out of the pouring port 3, and liquid is discharged through the liquid outlet channel; when the injection molding is completed, the plug 6 is located in the pouring port 3 and blocks the pouring port 3. The structure is simple and easy to install.

[0042] Furthermore, the sliding rod portion 5a, the connecting rod 5b and the plug 6 are an integrated structure.

[0043] In order to facilitate the discharge of liquid, the pouring port 3 is a cylindrical through hole, the sliding rod portion 5a is a cylindrical rod, and the diameter of the sliding rod portion 5a is larger than the diameter of the pouring port 3. The outer periphery of one end of the sliding rod portion 5a close to the connecting rod 5b is provided with a liquid discharge notch 7 connected to the liquid discharge channel. Figure 1-4 , as shown in Figure 6.

[0044] Furthermore, there are a plurality of liquid outlet notches 7 evenly distributed around the circumference. In this embodiment, there are four liquid outlet notches 7 evenly distributed around the circumference.

[0045] In order to guide the flow of molten plastic and facilitate the movement of the valve stem 5 away from the pouring port 3 so that the plug 6 can block the pouring port 3, the end face of the sliding rod portion 5a close to the connecting rod 5b is a frustum surface 8 whose diameter gradually decreases toward the connecting rod 5b side, and the hot runner 2 includes a frustum hole 2a connected to the pouring port 3, and the taper of the frustum hole 2a is adapted to the taper of the frustum surface 8.

[0046] The structure of the hot runner 2: The hot runner 2 also includes a cylindrical hole 2b, a truncated cone hole 2c and a cylindrical hole 2d which are connected in sequence to the truncated cone hole 2a. The diameter of the cylindrical hole 2d is greater than the diameter of the cylindrical hole 2b. The cylindrical hole 2b is connected to the truncated cone hole 2a, and the diameter of the cylindrical hole 2b is equal to the maximum diameter of the truncated cone hole 2a. The flow guiding effect is good and the material is easy to discharge.

[0047] In order to further facilitate the discharge of materials, the plug 6 is cylindrical, and the end surface of the plug 6 close to the connecting rod 5b is a frustum surface 9 whose diameter gradually decreases toward the connecting rod 5b side.

[0048] Structure of the elastic member: The elastic member is a compression spring 10 disposed between the slide rod portion 5 a and the diverter shuttle 4 , and a spring installation cavity 11 for installing the compression spring 10 is formed in the diverter shuttle 4 .

[0049] In order to guide the compression direction of the compression spring 10, a guide column 5c is provided at one end of the slide rod portion 5a away from the connecting rod 5b, and the compression spring 10 is sleeved on the guide column 5c.

[0050] Furthermore, the slide rod portion 5a and the guide column 5c are an integrated structure.

[0051] The structure of the hot runner body 1 is as follows: Figure 1-4 As shown, the hot runner body 1 includes a runner body 1a and a heating sleeve 1b sleeved on the outside of the runner body 1a, the hot runner 2 is arranged in the runner body 1a, the runner body 1a includes a feed sleeve 1a1, a mounting seat 1a2 and a runner sleeve 1a3 connected in sequence, the diverter shuttle 4 is fixed on the mounting seat 1a2 by a connecting strip 12, an air outlet gap 13 is left between the feed sleeve 1a1 and the runner sleeve 1a3, and an air outlet channel 14 connecting the spring mounting cavity 11 and the air outlet gap 13 is arranged on the diverter shuttle 4, the connecting strip 12 and the mounting seat 1a2 to prevent the pressure change in the spring mounting cavity 11 from affecting the movement of the valve stem 5.

[0052] Furthermore, the diverter shuttle 4, the connecting strip 12 and the mounting seat 1a2 are an integrated structure.

[0053] The specific connection method of the various components of the hot runner body 1 is as follows: the feed sleeve 1a1 is connected to the mounting seat 1a2 by threads, the mounting seat 1a2 and the runner sleeve 1a3 are connected by threads, the heating sleeve 1b is tightly sleeved outside the runner body 1a, and the heating sleeve 1b is provided with a ventilation groove connecting the air outlet gap 13 with the outside.

[0054] In order to position the installation of the feed sleeve 1a1 and the runner sleeve 1a3, a positioning boss is provided on the periphery of the mounting seat 1a2. The feed sleeve 1a1 and the mounting seat 1a2 are positioned by the outer peripheral surface of the positioning boss, and the runner sleeve 1a3 and the mounting seat 1a2 are positioned by the outer peripheral surface of the positioning boss.

[0055] The structure of the diverter shuttle 4 and the connecting strip 12 is as follows: Figure 2 , 6 As shown, the end of the diverter shuttle 4 away from the pouring port 3 is pointed, and the outer periphery is an arc-shaped guide surface. The connecting strip 12 is a shuttle shape with pointed ends and a wide middle, which guides the flow of the molten plastic to facilitate discharge.

[0056] The above embodiment is only one of the preferred embodiments of the present utility model, and is not intended to limit the scope of implementation of the present utility model. Therefore, any equivalent changes made based on the shape, structure, and principle of the present utility model should be included in the protection scope of the present utility model.

Claims

1. A self-sealing hot runner structure, characterized in that: The hot runner body (1) comprises a hot runner (2) arranged inside the hot runner body (1), one end of the hot runner (2) being connected to the nozzle of an injection molding machine and the other end being provided with a pouring port (3), a diverter shuttle (4) and an elastic member being arranged inside the hot runner (2), a valve stem (5) being slidably arranged on the diverter shuttle (4), and a plug (6) being arranged at one end of the valve stem (5) away from the diverter shuttle (4), during injection molding, the plug (6) opens the pouring port (3) under the elastic force of the elastic member; when injection molding is completed, the plug (6) overcomes the elastic force of the elastic member under the action of pressure to seal the pouring port (3).

2. A self-sealing hot runner structure according to claim 1, characterized in that: The valve stem (5) comprises a sliding rod portion (5a) with one end slidably arranged in the diverter shuttle (4), and a connecting rod (5b) connecting the sliding rod portion (5a) and a plug (6); the connecting rod (5b) is slidably arranged in the pouring port (3), and a gap is left between the connecting rod (5b) and the pouring port (3) to form a liquid outlet channel; during injection molding, one end of the connecting rod (5b) connected to the plug (6) extends out of the pouring port (3) and liquid is discharged through the liquid outlet channel; when the injection molding is completed, the plug (6) is located in the pouring port (3) and blocks the pouring port (3).

3. A self-sealing hot runner structure according to claim 2, characterized in that: The pouring port (3) is a cylindrical through hole, the sliding rod portion (5a) is a cylindrical rod, and the diameter of the sliding rod portion (5a) is larger than the diameter of the pouring port (3). An outlet notch (7) communicating with the outlet channel is provided on the outer periphery of one end of the sliding rod portion (5a) close to the connecting rod (5b).

4. A self-sealing hot runner structure according to claim 3, characterized in that: The end surface of the sliding rod portion (5a) close to the connecting rod (5b) is a frustum surface (8) whose diameter gradually decreases toward the side of the connecting rod (5b), and the hot runner (2) includes a frustum hole (2a) connected to the pouring port (3), and the taper of the frustum hole (2a) is adapted to the taper of the frustum surface (8).

5. The self-sealing hot runner structure according to claim 3, characterized in that: The plug (6) is cylindrical, and the end surface of the plug (6) close to the connecting rod (5b) is a second frustum surface (9) whose diameter gradually decreases toward the connecting rod (5b) side.

6. The self-sealing hot runner structure according to claim 2, characterized in that: The elastic member is a compression spring (10) arranged between the slide rod portion (5a) and the diverter shuttle (4), and a spring installation cavity (11) for installing the compression spring (10) is formed in the diverter shuttle (4).

7. A self-sealing hot runner structure according to claim 6, characterized in that: The hot runner body (1) comprises a runner body (1a) and a heating sleeve (1b) sleeved outside the runner body (1a); the hot runner (2) is arranged inside the runner body (1a); the runner body (1a) comprises a feed sleeve (1a1), a mounting seat (1a2) and a runner sleeve (1a3) connected in sequence; the diverter shuttle (4) is fixed to the mounting seat (1a2) via a connecting strip (12); an air outlet gap (13) is left between the feed sleeve (1a1) and the runner sleeve (1a3); and an air outlet channel (14) connecting the spring mounting cavity (11) and the air outlet gap (13) is arranged on the diverter shuttle (4), the connecting strip (12) and the mounting seat (1a2).

8. The self-sealing hot runner structure according to claim 7, characterized in that: The end of the diversion shuttle (4) away from the pouring port (3) is pointed, and the outer periphery is an arc-shaped flow guide surface, and the connecting strip (12) is in the shape of a shuttle with pointed ends and a wide middle.

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