Low-pressure hot cutting die

Abstract

The utility model is suitable for the technical field of injection molding, and provides a low-pressure hot cutting mold, which comprises a hot cutting mechanism arranged at a sprue, and the hot cutting mechanism comprises a cutter assembly and a pressure relief rod assembly which move in opposite directions; the gain transmission mechanism is connected with the cutter assembly and the pressure relief rod assembly, and the gain transmission mechanism is arranged to enable the cutter assembly to conduct a compression stroke and enable the pressure relief rod assembly to conduct an equivalent receding stroke at the same time under the action of the driving device. The equivalent amount means that the compression volume of the cutter assembly to the glue amount is equal to the abdicating volume of the pressure relief rod assembly to the glue amount. By means of the gain transmission mechanism with the self-locking function, the cutter assembly and the pressure relief rod assembly can synchronously and equivalently move in opposite directions and keep constant in the process that a cutter compresses rubber materials and seals a pouring gate, the pouring gate is separated from a product after the product is cooled and shaped, and therefore the technical effect of low-pressure hot cutting of the pouring gate is achieved.

Description

Technical Field

[0001] This utility model belongs to the field of injection molding technology, and in particular relates to a low-pressure hot-cutting mold. Background Technology

[0002] With the development of the injection molding and die casting industries, traditional techniques for removing runners or slag from molded products often involve manual or mechanical cutting outside the machine. However, with the maturation of in-mold hot-cutting technology in recent years, this technology has gradually gained application, enabling the automatic removal of runners or slag within the mold. Currently, this hot-cutting technology primarily uses a high-pressure micro-cylinder to drive a cutter to seal the inlet when the plastic is in a molten state after injection molding and pressure holding. After cooling and solidification, the product is separated from the runners or slag within the mold, achieving the effect of in-mold cutting.

[0003] However, if the hot-cutting blade does not close completely or retracts after reaching its position, the in-mold cutting effect will be poor, resulting in large burrs at the gate or even failure to cut. This is especially true for products with long injection molding holding times, where the material flow at the gate gradually solidifies due to the extended pause, increasing the viscosity and density of the material. This makes it difficult for the hot-cutting blade to compress the space, requiring significant power for extrusion. This high power demand necessitates the hydraulic pump to output extremely high-pressure hydraulic oil, and the hydraulic cylinders and circuits must withstand extremely high pressure, which can easily lead to damage or necessitates the design of equipment or devices with extremely high pressure resistance. Simultaneously, the hot-cutting blade, subjected to extremely high forces, may deform or break, affecting its service life.

[0004] Based on this, the present invention designs a low-pressure hot cutting mold to solve the above problems. Utility Model Content

[0005] The purpose of this utility model embodiment is to provide a low-pressure hot cutting mold, which aims to solve the technical problems existing in the prior art mentioned in the background art.

[0006] To solve the above-mentioned technical problems, this utility model provides the following technical solution: a low-pressure hot-cutting mold, comprising:

[0007] A hot cutting mechanism is provided at the gate, the hot cutting mechanism including a cutting blade assembly (2) moving in opposite directions and a pressure relief rod assembly;

[0008] A gain transmission mechanism connects the cutter assembly and the pressure relief rod assembly. The gain transmission mechanism is configured such that, under the action of the drive device, the cutter assembly performs a compression stroke while the pressure relief rod assembly performs an equal amount of yielding stroke.

[0009] Furthermore, the term "equal amount" means that the compression volume of the adhesive by the cutter assembly is equal to the clearance volume of the adhesive by the pressure relief rod assembly.

[0010] The gain transmission mechanism has a self-locking function.

[0011] Preferably, the gain transmission mechanism adopts any of the following structures:

[0012] A double-sided T-shaped wedge assembly includes a wedge block with bidirectional inclined surfaces and a corresponding slider mating surface;

[0013] A lever-type linkage assembly, comprising a lever assembly consisting of a fulcrum shaft and a lever arm;

[0014] A gear and rack assembly, comprising meshing equal-module gears and counter-rotating racks;

[0015] Cam linkage assembly, including a coaxial double cam assembly with symmetrical profile;

[0016] A parallel hinge four-bar assembly, comprising a symmetrical hinged system consisting of multiple links.

[0017] Preferably, the cutter assembly includes:

[0018] Cutter mounting plate, used to mount the cutter;

[0019] The cutter is slidably fitted inside the mold cavity and fixed on the cutter mounting plate;

[0020] A cutter connecting rod connects the bottom of the cutter mounting plate to the gain transmission mechanism.

[0021] Preferably, the pressure relief rod assembly includes:

[0022] Pressure relief bar mounting plate, used to install the pressure relief bar;

[0023] The pressure relief rod is slidably fitted inside the mold cavity and is fixed to the pressure relief rod mounting plate;

[0024] A pressure relief connecting rod connects the pressure relief rod and the gain transmission mechanism.

[0025] Preferably, it also includes a guiding mechanism, which includes at least two sets of parallel guide posts, the two sets of guide posts forming a sliding fit with the cutter mounting plate and the pressure relief rod mounting plate, respectively.

[0026] Preferably, the driving device is a hydraulic drive system or a pneumatic drive system.

[0027] Preferably, the force gain ratio of the gain transmission mechanism is at least 0.

[0028] The present invention is implemented as follows:

[0029] I. This utility model uses the injection molding machine signal output control system to drive the oil or air circuit, thereby pushing the oil or air cylinder forward. Through the synchronous equidistant opposite gain amplification effect of the gain transmission mechanism, the cutter can advance and compress the rubber material, ultimately achieving the sealing of the gate. At the same time, the retraction action of the synchronous pressure relief rod releases an equal amount of pressure relief space, ensuring that the volume of compressed rubber material is replaced by the amount of pressure relief. This process ensures that the overall volume and cavity pressure (only including the initial pressure value of the runner cavity, the pressure value after holding pressure is almost zero) remain constant during the process of the cutter compressing the rubber material and sealing the gate. After the product cools and sets, the gate separates from the product, thus achieving the technical effect of low-pressure hot-cut gate.

[0030] II. This utility model is equipped with a low-pressure hot cutting mechanism with a cutter and a pressure relief rod at the gate. During the hot cutting and retraction process, the cutter and the pressure relief rod move synchronously and equally, ensuring that the compression volume of the cutter is equal to the retraction volume of the pressure relief rod. By adopting five types of gain transmission mechanisms, including but not limited to double-sided T-shaped wedge assembly, lever linkage assembly, gear and rack combination assembly, cam linkage assembly and parallel hinge four-bar linkage assembly, synchronous equidistant opposite movement of the cutter assembly and the pressure relief rod assembly is achieved, thereby achieving pressure balance and self-locking effect. Attached Figure Description

[0031] Figure 1 A schematic diagram of the overall structure provided for an embodiment of this utility model;

[0032] Figure 2 Provided for the embodiments of this utility model Figure 1 Side view;

[0033] Figure 3 Provided for embodiments of this utility model Figure 1 Schematic diagram of the cross-sectional structure at point AA;

[0034] Figure 4 Provided for embodiments of this utility model Figure 3 Schematic diagram of the cross-sectional structure at point BB;

[0035] Figure 5 A schematic diagram of the lever-type linkage component is provided for an embodiment of this utility model;

[0036] Figure 6 A schematic diagram of the gear and rack assembly is provided for embodiments of this utility model;

[0037] Figure 7 A schematic diagram of the cam linkage assembly is provided for an embodiment of this utility model;

[0038] Figure 8 A schematic diagram of the parallel hinge four-bar linkage assembly is provided for an embodiment of this utility model.

[0039] In the diagram: 1. Hot cutting mechanism; 2. Cutting blade assembly; 201. Cutting blade mounting plate; 202. Cutting blade; 203. Cutting blade connecting rod; 3. Pressure relief rod assembly; 301. Pressure relief rod mounting plate; 302. Pressure relief rod; 303. Pressure relief connecting rod; 4. Gain transmission mechanism; 401. Double-sided T-shaped wedge assembly; 402. Lever-type linkage assembly; 403. Gear and rack combination assembly; 404. Cam linkage assembly; 405. Parallel hinge four-bar linkage assembly; 5. Guide mechanism; 501. Guide column. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0041] It is understood that the terms “first,” “second,” etc., used in this application may be used herein to describe various elements, but unless otherwise stated, these elements are not limited by these terms. These terms are used only to distinguish one element from another.

[0042] like Figure 1 - Figure 2 As shown, in one embodiment, a low-pressure hot-cutting die is provided, comprising:

[0043] A hot cutting mechanism 1 is installed at the gate. The hot cutting mechanism 1 includes a cutter assembly 2 and a pressure relief rod assembly 3 that move in opposite directions.

[0044] The gain transmission mechanism 4 connects the cutter assembly 2 and the pressure relief rod assembly 3. The gain transmission mechanism 4 is configured such that, under the action of the drive device, the cutter assembly 2 performs a compression stroke while the pressure relief rod assembly 3 performs an equal amount of yielding stroke.

[0045] Furthermore, the term "equal amount" means that the compression volume of the adhesive by the cutter assembly 2 is equal to the clearance volume of the adhesive by the pressure relief rod assembly 3.

[0046] Among them, the gain transmission mechanism 4 has a self-locking function.

[0047] In one embodiment of the present invention, the low-pressure hot-cutting mold achieves automatic removal of the in-mold gate through the hot-cutting mechanism 1. When the drive device is started, the gain transmission mechanism 4 decomposes the driving force into two equal and opposite motion components. The cutter assembly 2 generates a compression stroke S2 ​​to move upward and compress the molten material, while the pressure relief rod assembly 3 generates a relief stroke S1 to move downward and release the cavity space, satisfying the displacement balance relationship of S1=S2, ensuring that the compressed volume is equal to the pressure relief volume, and maintaining the cavity pressure constant at the initial holding pressure value. The mechanical structure of the gain transmission mechanism 4 generates a self-locking effect after the cutter is in place, preventing the injection pressure from pushing the cutter back.

[0048] In this embodiment, after the injection molding pressure holding is completed, the oil cylinder or air cylinder is pushed forward by the output of high-pressure oil or high-pressure air from the neutron oil circuit or air circuit of the injection molding machine, or by the output oil circuit of the external dedicated in-mold cutting controller, thereby driving the gain transmission mechanism 4 forward. After the product cools and solidifies, the product separates from the gate, achieving the effect of low-pressure hot cutting. Conversely, before the injection molding mold is closed, the cutter 202 is driven to retract by a distance S2, and the bottom of the cutter mounting plate 201 touches the support column to play the role of injection molding support and positioning; at the same time, the pressure relief rod 302 is driven to advance by a distance S1.

[0049] In fact, the above description describes the case where the compression stroke S2 ​​and the yield stroke S1 are the same, and the effective cross-sectional areas of the cutter assembly 2 and the pressure relief rod assembly 3 are equal to ensure equal volume. However, in another case of the present invention, the yield stroke S1 and the compression stroke S2 ​​may not be equal, and the effective cross-sectional areas may also not be equal. In this case, equal volume can also be achieved.

[0050] In one embodiment, the gate structure includes, but is not limited to, any one of side gate, disc perimeter gate, or submersible gate. The opposing self-locking gainer is suitable for thermoplastic injection molding or metal die casting.

[0051] Please see Figure 3 - Figure 5 In a preferred embodiment of this utility model, the gain transmission mechanism 4 adopts any of the following structures:

[0052] The double-sided T-shaped wedge assembly 401 includes a wedge block with bidirectional inclined surfaces and a corresponding slider mating surface;

[0053] Lever-type linkage assembly 402 includes a lever assembly consisting of a fulcrum shaft and a lever arm;

[0054] The gear and rack assembly 403 includes a set of equal-module gears and a rack that meshes with each other.

[0055] Cam linkage assembly 404 includes a coaxial double cam assembly with symmetrical profile;

[0056] Parallel hinge four-bar assembly 405, comprising a symmetrical hinge system consisting of multiple links.

[0057] In practical application, the gain transmission mechanism 4 achieves power transmission through any of the above methods. The bidirectional inclined wedge block in the double-sided T-shaped wedge assembly 401 decomposes the axial thrust F of the oil cylinder into the cutting force and the pressure relief rod force. The lever-type linkage assembly 402, with the fulcrum shaft as the center, transmits the driving force equally to the cutting force and the pressure relief rod, satisfying the torque balance. The gear rack assembly 403 and the cam linkage assembly 404, etc., simultaneously mesh with the reverse rack, converting the rotational motion into linear reverse motion.

[0058] It should be noted that, due to the function of the double-sided T-shaped wedge assembly 401 of the gain transmission mechanism 4, the angle of inclination is relatively small, which can also play the role of amplifying the output force gain. Conversely, it has the function of self-locking—the injection pressure is not easy to reverse and retreat. The structure of the gain transmission mechanism 4 can also be as exemplified in five ways, but is not limited to these five structures. All the functions of achieving equidistant opposite gain should be included in the scope of this technology. All five gain transmission mechanisms 4 output gain output rod one and gain output rod two, which are ultimately connected to the cutter 202 and the pressure relief rod 302, respectively, driving the cutter 202 and the pressure relief rod 302 to move synchronously and equally in opposite directions, while simultaneously amplifying the output force gain and self-locking to prevent retreat.

[0059] Please see Figure 1 In another preferred embodiment of this utility model, the cutter assembly 2 includes:

[0060] Cutter mounting plate 201 is used to mount cutter 202;

[0061] The cutter 202 is slidably fitted inside the mold cavity and fixed on the cutter mounting plate 201;

[0062] The cutter connecting rod 203 connects the bottom of the cutter mounting plate 201 to the gain transmission mechanism 4.

[0063] In this embodiment, the cutter mounting plate 201 is guided to move vertically by the guide post 501. The cutter connecting rod 203 contacts and positions itself with the template when it retracts, ensuring the repeatability and positioning accuracy of the cutter 202. The cutter 202 adopts a tapered cutting edge, which, together with the stepped end face of the pressure relief rod 302, achieves burr-free cutting of the gate.

[0064] Please see Figure 1 In another preferred embodiment of this utility model, the pressure relief rod assembly 3 includes:

[0065] Pressure relief rod mounting plate 301 is used to install pressure relief rod 302;

[0066] The pressure relief rod 302 is slidably fitted inside the mold cavity, and the pressure relief rod 302 is fixed on the pressure relief rod mounting plate 301;

[0067] The pressure relief connecting rod 303 connects the pressure relief rod 302 and the gain transmission mechanism 4.

[0068] Please see Figure 1 As another preferred embodiment of the present invention, it also includes a guide mechanism 5, which includes at least two sets of parallel guide posts 501, and the two sets of guide posts 501 respectively form a sliding fit with the cutter mounting plate 201 and the pressure relief rod mounting plate 301.

[0069] In this embodiment, the two sets of guide posts 501 are fitted with graphite copper sleeves to ensure the linearity of the movement of the cutter 202 / pressure relief rod assembly 3. The guide posts 501 play a guiding role in the movement of the cutter mounting plate 201 and the pressure relief rod mounting plate 301, keeping the movement smooth. After the product cools and solidifies, the product separates from the gate, achieving the effect of low-pressure hot cutting.

[0070] Please see Figure 2 In another preferred embodiment of this utility model, the driving device adopts a hydraulic drive system or a pneumatic drive system.

[0071] In this embodiment, the hydraulic drive system or the pneumatic drive system achieves precise control of the opposing self-locking gainers through the control valve group, ensuring the synchronous movement of the cutter assembly 2 and the pressure relief rod assembly 3. In the hydraulic drive system, the oil pump provides stable hydraulic pressure, which is transmitted to the gain transmission mechanism 4 through the oil circuit to realize the transmission and conversion of power. In the pneumatic drive system, the compressor provides compressed air, which is connected to the gain transmission mechanism 4 through the air pipe to realize the transmission of power. Both drive methods can be selected according to actual needs to meet the requirements of different injection molding or die casting processes.

[0072] Please see Figure 1 In another preferred embodiment of this utility model, the force gain ratio of the gain transmission mechanism 4 is at least 0, preferably 2:1 to 5:1. In fact, as long as the cutter assembly 2 and the pressure relief rod assembly 3 move in opposite directions, the desired technical effect of this embodiment can be achieved; only the degree of effect will vary with different gain ratios.

[0073] In this embodiment, the selection of the force gain ratio ensures that under the limited power provided by the drive device, the gain transmission mechanism 4 can effectively amplify the driving force and transmit it to the cutter assembly 2 and the pressure relief rod assembly 3 to achieve the required equal reverse motion. This not only improves the hot cutting efficiency but also reduces the power requirements of the drive device and extends the service life of the equipment.

[0074] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0075] The embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

[0076] 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. A low-pressure hot-cutting die, characterized in that, include: A hot cutting mechanism (1) is provided at the gate. The hot cutting mechanism (1) includes a cutting blade assembly (2) and a pressure relief rod assembly (3) that move in opposite directions. Gain transmission mechanism (4) connects the cutter assembly (2) and the pressure relief rod assembly (3). The gain transmission mechanism (4) is configured such that, under the action of the drive device, the cutter assembly (2) performs a compression stroke while the pressure relief rod assembly (3) performs an equal amount of yielding stroke. Furthermore, the equal volume refers to the compression volume of the adhesive by the cutter assembly (2) being equal to the clearance volume of the adhesive by the pressure relief rod assembly (3); The gain transmission mechanism (4) has a self-locking function.

2. The low-pressure hot-cutting die according to claim 1, characterized in that, The gain transmission mechanism (4) adopts any of the following structures: A double-sided T-shaped wedge assembly (401) includes a wedge block with bidirectional inclined surfaces and a corresponding slider mating surface; A lever-type linkage assembly (402) includes a lever assembly consisting of a fulcrum shaft and a lever arm; A gear and rack assembly (403) includes meshing equal-module gears and counter-rotating racks; The cam linkage assembly (404) includes a coaxial double cam assembly with a symmetrical profile; Parallel hinge four-bar assembly (405), comprising a symmetrical hinged system consisting of multiple links.

3. The low-pressure hot-cutting die according to claim 1, characterized in that, The cutting blade assembly (2) includes: A cutter mounting plate (201) is used to mount a cutter (202); The cutter (202) is slidably fitted inside the mold cavity and fixed on the cutter mounting plate (201); The cutter connecting rod (203) connects the bottom of the cutter mounting plate (201) to the gain transmission mechanism (4).

4. A low-pressure hot-cutting die according to claim 1, characterized in that, The pressure relief rod assembly (3) includes: Pressure relief rod mounting plate (301) for mounting pressure relief rod (302); The pressure relief rod (302) is slidably fitted inside the mold cavity, and the pressure relief rod (302) is fixed on the pressure relief rod mounting plate (301); A pressure relief connecting rod (303) connects the pressure relief rod (302) and the gain transmission mechanism (4).

5. A low-pressure hot-cutting die according to claim 1, characterized in that, It also includes a guide mechanism (5), which includes at least two sets of parallel guide posts (501), and the two sets of guide posts (501) respectively form a sliding fit with the cutter mounting plate (201) and the pressure relief rod mounting plate (301).

6. A low-pressure hot-cutting die according to claim 1, characterized in that, The drive device adopts a hydraulic drive system or a pneumatic drive system.

7. A low-pressure hot-cutting die according to claim 1, characterized in that, The force gain ratio of the gain transmission mechanism (4) is at least 0.

Images