Injection molding device and molding method for toothbrush handle

Abstract

The present invention belongs to the field of injection molding technology, and specifically relates to a toothbrush handle injection molding device and molding method, including a fixed mold frame, a mobile mold frame and a mobile component, the fixed mold frame is fixed to the injection molding frame mold, at least one mobile sub-mold is arranged on the fixed mold frame, the mobile sub-mold is telescopically installed in the fixed mold frame, a mold cavity for injection molding filling is opened on the top of the mobile sub-mold, the mobile mold frame is located on the opposite side of the fixed mold frame, and moves closer or farther away, and is arranged on one side of the fixed mold frame, and it moves forward or backward in the direction of the mobile mold frame, and a mobile mold core is inserted and fixed on the mobile component, and a flow path for passing the injection molding sol is arranged inside the mobile mold core. The invention can make the injection molding sol not be affected by the structural temperature when it flows, maintain the temperature of the components of the internal structure, increase the flow rate length and flow smoothly during high-speed filling, so that the material is more evenly distributed in the entire mold cavity, thereby improving the injection molding quality and stabilizing the product size.

Description

Technical Field

[0001] The invention belongs to the technical field of injection molding, and in particular relates to an injection molding device and a molding method for a toothbrush handle. Background Art

[0002] Injection molding machine is also known as injection molding machine or injection machine. Many factories call it beer machine and injection products are called beer parts. It is the main molding equipment that uses plastic molding molds to make plastic products of various shapes from thermoplastics or thermosetting materials. Injection molding machines can be divided into vertical, horizontal and vertical-horizontal composite types according to the arrangement of the injection device and the clamping device.

[0003] In the typical extrusion injection molding system commonly seen in the existing market, in one cycle of the injection molding machine, a certain amount of plastic is heated and plasticized within a specified time, and then injected into the mold cavity by injection at a certain pressure and speed. After the injection is completed, the molten material injected into the mold cavity is kept in a fixed shape. However, this method may also cause the following problems when applied to the handle of an electric toothbrush. Due to the axial length of the handle of an electric toothbrush, the injection molding is mostly started from the bottom during injection molding. This section is also the main section of the toothbrush formed. As a result, the sol flow is uneven due to the unstable injection pressure or the temperature of the head and tail of the axial length component during the injection process, resulting in a low yield rate of the workpiece. Summary of the invention

[0004] The object of the present invention is to provide a toothbrush handle injection molding device and molding method, which can ensure that the plastic sol to be injected will not be affected by the structural temperature during flow, maintain the component temperature of the internal structure, increase the flow rate length and make the flow stable during high-speed filling, so that the material is more evenly distributed in the entire mold cavity, thereby improving the injection molding quality and stabilizing the product size.

[0005] The technical solution adopted by the present invention is as follows:

[0006] A toothbrush handle injection molding device and molding method, comprising a fixed mold frame, a movable mold frame and a movable assembly, wherein the fixed mold frame is fixed to an injection molding frame mold, and at least one movable sub-mold is arranged on the fixed mold frame, and the movable sub-mold is telescopically installed in the fixed mold frame, and a mold cavity for injection molding filling is opened on the top of the movable sub-mold, and the movable mold frame is located on the opposite side of the fixed mold frame, and moves closer or farther, and is arranged on one side of the fixed mold frame, and moves forward or backward in the direction of the movable mold frame, and a movable mold core is inserted and fixed on the movable assembly, and a flow path for passing the injection molding sol is arranged inside the movable mold core;

[0007] When the fixed mold frame and the movable mold frame are close to each other, the movable mold core is located in the mold cavity and does not fit the cavity wall of the mold cavity. The injection sol is injected into the cavity formed between the movable mold core and the mold cavity through the flow path, and a toothbrush handle is formed through injection molding. When the fixed mold frame and the movable mold frame are separated from each other, the movable mold core withdraws from the mold cavity and moves away from the movable sub-mold, and the toothbrush handle after injection molding remains in the mold cavity.

[0008] In a preferred embodiment, the fixed mold frame is provided with the same number of telescopic slots as the movable sub-mold, one side of the telescopic slot is provided with a fixed baffle, and the other side is provided with a fixed socket;

[0009] A groove is provided on the fixed mold frame adjacent to the fixed baffle, and a slide plate is provided on the side of the fixed mold frame corresponding to the groove. The moving component slides on the slide plate to drive the moving mold core to reciprocate through the fixed baffle to complete injection molding or demoulding.

[0010] In a preferred embodiment, a corresponding mold cavity is provided on the bottom surface of the movable mold frame at a position corresponding to the movable sub-mold, so that the toothbrush handle forms a complete columnar shape.

[0011] In a preferred embodiment, the movable mold core comprises an injection cylinder, a middle cylinder and an outer tube, the injection cylinder is fixed on the movable assembly, and the injection cylinder is combined with the outer tube through the middle cylinder;

[0012] A heat transfer inner tube is arranged inside the outer tube, and the flow path is axially arranged inside the heat transfer inner tube. The plastic sol to be injected passes through the injection cylinder, the middle cylinder and the heat transfer inner tube in sequence, and flows out from the end of the heat transfer inner tube. The material used for the heat transfer inner tube is any one of aluminum alloy, copper alloy or steel alloy.

[0013] In a preferred embodiment, the flow path includes a first jet chamber, a second jet chamber, a third jet chamber, an inner valve chamber, a fourth jet chamber and an outlet, which are arranged near the moving component. The aperture of the first jet chamber gradually decreases as it moves away from the moving component. The second jet chamber is combined with the end section of the first jet chamber. The aperture direction of the second jet chamber continues the aperture direction of the first jet chamber, and the overall trend is gradually shrinking. The third jet chamber is combined with the end section of the second jet chamber, and the cross-section of the third jet chamber is flared, which gradually expands as it moves away from the moving component. The inner valve chamber is located downstream of the third jet chamber, and a nozzle structure is provided inside. The fourth jet chamber is arranged at the outlet position of the inner valve chamber, and its cross-section is also flared, and gradually expands as it moves away from the moving component. The outlet is arranged at the port of the outer tube corresponding to the position of the fourth jet chamber, and the injection sol is discharged from the outlet.

[0014] In a preferred embodiment, an expansion concave ring is opened inwardly along the inner annular surface of the second jet cavity, and the ring diameter of the expansion concave ring is enlarged to accelerate the flow rate.

[0015] In a preferred embodiment, the nozzle structure includes a plug body and a nozzle, the plug body is arranged along the axial direction of the inner valve chamber, and one end of the plug body is against the downstream outlet position of the third jet chamber, and the other end is provided with an open liquid outlet channel, the annular side of the plug body is provided with a liquid inlet communicated with the liquid outlet channel, the nozzle protrudes toward one side of the liquid outlet channel and extends into the liquid outlet channel, a first spring is provided between the nozzle and the plug body, the outer annular surface of the nozzle is tightly abutted against the cavity wall of the inner valve chamber, at least one passage is provided inside the nozzle and communicated with the outside, and outlets of multiple passages merge to form an outlet channel;

[0016] The first spring supports the plug body so that the end of the plug body abuts against and closes the outlet of the third jet cavity.

[0017] In a preferred embodiment, an air chamber is provided around the inner valve chamber in the heat transfer inner tube to prevent the liquid to be injected from losing heat too quickly at the outlet.

[0018] In a preferred embodiment, the annular side surface of the inner heat transfer tube facing the middle tube is concave, and this end does not contact the inner annular surface of the outer tube, forming a notch connected to the middle tube, and the port of the middle tube is adapted to extend from the notch to form a connecting plug, and the connecting plug is detachably coupled to the inside of the notch, so that the middle tube and the outer tube are connected through this structure.

[0019] In a preferred embodiment, the fixed socket and the movable mold core are arranged opposite to each other, and the plug of the fixed socket is a retractable end of the movable mold core. After the injection molding is completed, a cavity for plugging the toothbrush head is reserved at the end of the toothbrush handle. The specific structure of the fixed socket includes:

[0020] A fixed column is arranged on the wall of the telescopic groove, and an inner cavity is opened inside the fixed column. The second spring and a movable plug are installed in the cavity. Under normal conditions, the movable plug is supported by the second spring and extends out of the cavity mouth of the inner cavity to the outlet of the movable mold core.

[0021] A method for injection molding a toothbrush handle, comprising the following steps:

[0022] Step 1: First, close the fixed mold frame and the movable mold frame, and ensure that the parts of the two mold frames are correctly aligned to prepare for the injection of the sol;

[0023] Step 2: After the sol is injected into the injection barrel through the external connecting tube, it passes through the injection barrel, the middle barrel and the outer barrel in sequence. The sol is injected and filled into the mold cavity under the pressure of the screw or plunger. In this step, the injection process needs to maintain high pressure all the time;

[0024] Step 3: After the sol fills the mold cavity, continue to pressurize to compensate for the volume reduction during the cooling and shrinkage of the sol, ensuring the product's accurate size and stable performance. It is worth noting that during the injection process in step 3, the injection molding machine needs to keep a certain amount of plastic in a molten state for continuous supply. This process is called storage;

[0025] Step 4: The sol is cooled and hardened in the mold cavity to become the final molded product. During this process, the temperature of the chilled water is required to be less than 25 degrees and the temperature of the cooling water is required to be less than 32 degrees before entering the next step;

[0026] Step 5: After the sol is completely cooled and solidified, the fixed mold frame is separated from the movable mold frame, and the movable assembly drives the movable mold core to retreat as a whole until it exits the fixed baffle. At this time, the molded toothbrush handle remains in the mold cavity, and the movable sub-mold is moved down to make the toothbrush handle empty. Finally, the toothbrush handle is removed to complete the injection molding and removal.

[0027] The technical effects achieved by the present invention are:

[0028] In the present invention, due to the injection barrel and its internal structure, the injection molding process is affected by the structure and prolonged. By utilizing the heat exchange efficiency characteristics of the special material of the heat transfer inner tube, the temperature of the plastic sol to be injected flowing inside can be made more uniform. For example, the temperature difference between the tail and the end of the component structure is caused by the heat transfer inner tube, and the heat is quickly conducted, so that the plastic sol to be injected will not be affected by the temperature of the structure when flowing, and the temperature of the internal structure is maintained, and the influence of the temperature of the component on the plastic sol to be injected is reduced, so that the flow rate is in an overall stable high flow rate state, and the influence of the temperature on the injection speed (affected by the temperature difference between the tail and the end) can be reduced;

[0029] In the present invention, the junction of the first jet cavity and the second jet cavity is the throat at the first location. The fluid increases its flow rate through the throat at the first location. When entering the second jet cavity, the cavity shrinks as the inner cavity shape of the second jet cavity moves, and the fluid also gradually shrinks and increases its speed until it reaches the throat at the second location formed by the junction of the second jet cavity and the third jet cavity. The fluid is accelerated again in the throat. At this time, the fluid moves in the tube in the form of a larger flow rate at a narrower cross-section, thereby achieving the effect of twice increasing speed in the first jet cavity, the second jet cavity and the third jet cavity. It is worth mentioning that the fourth jet cavity is set as an expansion setting, and its ejection diameter is also a narrow throat setting. The last acceleration occurs when the sol is ejected. Combining the above two acceleration structures, the present application can increase the injection speed during the injection molding of the sol. High-speed filling increases the flow rate length and makes the flow smooth, reduces the overall flow resistance, and makes the material more evenly distributed in the entire mold cavity, thereby improving the injection molding quality and stabilizing the product size. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0031] Figure 2 It is a schematic diagram of the displacement structure of the mobile mold core on the fixed mold frame in the present invention;

[0032] Figure 3 It is a schematic diagram of the separation structure of the fixed mold frame, the movable mold frame, the movable sub-mold, and the movable mold core in the present invention;

[0033] Figure 4 Schematic diagrams of the movable mold frame of the present invention from two different perspectives;

[0034] Figure 5 It is a structural schematic diagram of the movable mold core in the present invention;

[0035] Figure 6 The present invention Figure 5 Schematic diagram of the axial separation structure of the moving mold core;

[0036] Figure 7 The present invention Figure 6 Schematic diagram of the AA section structure;

[0037] Figure 8 The present invention Figure 7 Schematic diagram of the plan structure of the section;

[0038] Fig. 9 It is a schematic diagram of the cross-sectional structure of the outer tube and the heat transfer inner tube in the present invention;

[0039] Fig.10 is a cross-sectional schematic diagram of the aperture variation structure of the second jet cavity in the present invention;

[0040] Fig.11 is a cross-sectional schematic diagram of the aperture variation structure of the second jet cavity in the present invention;

[0041] Fig.12 The present invention Figure 8 A schematic diagram of the structure enlargement at point A;

[0042] Fig.13 It is a structural schematic diagram of the fixed socket in the present invention.

[0043] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0044] 1. Fixed mold frame; 101. Telescopic slot; 102. Fixed baffle; 103. Groove; 104. Slide plate; 105. Moving assembly;

[0045] 2. Mobile mold frame;

[0046] 3. Moving sub-mold; 301. Mold cavity;

[0047] 4. Moving mold core; 401. Injection cylinder; 402. Middle cylinder; 403. Outer tube; 404. Heat transfer inner tube;

[0048] 405, flow path; 4051, first jet cavity; 4052, second jet cavity; 4053, expansion concave ring; 4054, third jet cavity; 4055, inner valve chamber; 4056, fourth jet cavity; 4057, outlet; 406, plug body; 407, liquid inlet; 408, liquid outlet channel; 409, nozzle; 410, first spring; 411, passage; 412, outlet channel; 413, air chamber; 414, notch; 415, connecting nozzle;

[0049] 5. Fixed socket; 501. Fixed column; 502. Inner cavity; 503. Second spring; 504. Active plug. DETAILED DESCRIPTION

[0050] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0051] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0052] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure or characteristic that may be included in at least one implementation of the present invention. The phrase "in a preferred embodiment" that appears in different places in this specification does not refer to the same embodiment, nor is it a separate or selective embodiment that is mutually exclusive with other embodiments.

[0053] Secondly, the present invention is described in detail with reference to the schematic diagram. When describing the embodiments of the present invention in detail, for the sake of convenience, the cross-sectional diagrams showing the device structure will not be partially enlarged according to the general scale, and the schematic diagrams are only examples, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0054] Please see attached Figure 1-Figure 3As shown, the present invention provides a toothbrush handle injection molding device and molding method, comprising a fixed mold frame 1, a mobile mold frame 2 and a mobile component 105, the fixed mold frame 1 is fixed to the injection frame mold, at least one mobile sub-mold 3 is arranged on the fixed mold frame 1, the mobile sub-mold 3 is telescopically installed in the fixed mold frame 1, and a mold cavity 301 for injection filling is opened on the top of the mobile sub-mold 3, the mobile mold frame 2 is located on the opposite side of the fixed mold frame 1, and moves closer or farther away, and is arranged on one side of the fixed mold frame 1, and moves forward or backward in the direction of the mobile mold frame 2, and a mobile mold core 4 is inserted and fixed on the mobile component 105, and a flow path 405 for passing the injection sol is arranged inside the mobile mold core 4;

[0055] When the fixed mold frame 1 and the movable mold frame 2 are close to each other, the movable mold core 4 is located in the mold cavity 301 and is not in contact with the cavity wall of the mold cavity 301. The injection sol is injected into the cavity formed between the movable mold core 4 and the mold cavity 301 through the flow path 405, and a toothbrush handle is formed through injection molding. When the fixed mold frame 1 and the movable mold frame 2 are away from each other, the movable mold core 4 withdraws from the mold cavity 301 and moves away from the movable sub-mold 3, and the toothbrush handle after injection molding remains in the mold cavity 301.

[0056] Specifically, the moving component 105 in the present application is a component that can fix the moving mold core 4 and can complete sliding. It can be a moving plate, a moving block or a combination of two or more plates / components / blocks. The end face of the moving component 105 can be provided with a cylinder or a motor screw to realize the forward or backward movement of the moving mold core 4. This step can be implemented according to the actual production situation using a variety of technical means in the prior art, and will not be elaborated here.

[0057] See also Figure 2-Figure 4 The fixed mold frame 1 is provided with the same number of telescopic slots 101 as the movable sub-mold 3, a fixed baffle 102 is provided on one side of the telescopic slot 101, and a fixed socket 5 is provided on the other side. A groove 103 is provided on the fixed mold frame 1 adjacent to the fixed baffle 102, and a slide plate 104 is provided on the side of the fixed mold frame 1 corresponding to the groove 103. The movable component 105 slides on the slide plate 104 to drive the movable mold core 4 to reciprocate through the fixed baffle 102 to complete injection molding or demolding.

[0058] Specifically, the movable sub-mold 3 is located in the telescopic groove 101 and performs a telescopic stroke.

[0059] See also Figure 2-Figure 4 A corresponding mold cavity 301 is provided on the bottom surface of the movable mold frame 2 corresponding to the position of the movable auxiliary mold 3, so that the toothbrush handle forms a complete columnar shape.

[0060] It should be specifically explained that the bottom surface of the movable mold frame 2 corresponds to the top surface structure of the fixed mold frame 1 and is provided with corresponding grooves. When the fixed mold frame 1 and the movable mold frame 2 are facing each other, the movable mold frame 2 fits with the fixed mold frame 1 according to the corresponding grooves to avoid mold flash during injection molding.

[0061] See also Figure 6 The movable mold core 4 includes an injection barrel 401, a middle barrel 402 and an outer tube 403. The injection barrel 401 is fixed on the movable assembly 105, and the injection barrel 401 is combined with the outer tube 403 through the middle barrel 402;

[0062] The outer tube 403 is provided with a heat transfer inner tube 404, and the flow path 405 is axially provided inside the heat transfer inner tube 404. The plastic sol to be injected passes through the injection cylinder 401, the middle cylinder 402 and the heat transfer inner tube 404 in sequence, and flows out from the end of the heat transfer inner tube 404.

[0063] The material used for the heat transfer inner tube 404 is any one of aluminum alloy, copper alloy or steel alloy.

[0064] Based on the above, in the present application, due to the injection barrel 401 and its internal structure, the injection molding process is affected by the structure and prolonged. By utilizing the heat exchange efficiency characteristics of the special material of the heat transfer inner tube 404, the temperature of the plastic sol to be injected flowing inside can be made more uniform. For example, the temperature difference between the tail and the end of the component structure is that the heat transfer inner tube 404 is heated and then quickly conducts heat, so that the plastic sol to be injected will not be affected by the temperature of the structure when flowing, and the component temperature of the internal structure is maintained, and the influence of the component temperature on the plastic sol to be injected is reduced, so that the flow rate is in an overall stable high flow rate state, and the influence of the temperature on the injection speed (affected by the temperature difference between the tail and the end) can be reduced.

[0065] More specifically, see Figure 6-Figure 7 The annular side surface of the heat transfer inner tube 404 facing the middle tube 402 is concave, and this end does not contact the inner annular surface of the outer tube 403, forming a slot 414 connected to the middle tube 402. The port of the middle tube 402 adapts to the slot 414 and extends to form a connecting plug 415. The connecting plug 415 is detachably combined with the inside of the slot 414, so that the middle tube 402 and the outer tube 403 are connected through this structure.

[0066] See also Figure 6-Figure 8The flow path 405 includes a first jet cavity 4051, a second jet cavity 4052, a third jet cavity 4054, an inner valve cavity 4055, a fourth jet cavity 4056 and an outlet 4057 arranged near the moving component 105. The aperture of the first jet cavity 4051 gradually decreases as it moves away from the moving component 105. The second jet cavity 4052 is combined with the end section of the first jet cavity 4051. The aperture direction of the second jet cavity 4052 continues the aperture direction of the first jet cavity 4051, and the overall trend is gradually decreasing. The aperture direction of the third jet cavity 4056 is gradually decreasing. 054 is combined with the end section of the second jet cavity 4052, and the cross-section of the third jet cavity 4054 is flared, and gradually expands as it moves away from the moving component 105. The inner valve chamber 4055 is located downstream of the third jet cavity 4054, and a nozzle structure is provided inside. The fourth jet cavity 4056 is provided at the outlet position of the inner valve chamber 4055, and its cross-section is also flared, and gradually expands as it moves away from the moving component 105. The outlet 4057 is provided at the port of the outer tube 403 corresponding to the position of the fourth jet cavity 4056, and the plastic sol to be injected is discharged from the outlet 4057.

[0067] See also Figure 9-10 An expansion concave ring 4053 is also opened inward along the inner annular surface of the second jet cavity 4052, and the ring diameter of the expansion concave ring 4053 is enlarged to accelerate the flow rate.

[0068] It should be further explained that the first jet chamber 4051, the second jet chamber 4052, and the third jet chamber 4054 in the above structure form a step-by-step pressurized flow path, which overall forms a double speed-increasing effect and creates an environment for liquid jet acceleration:

[0069] The ring diameter of the first jet cavity 4051 is set to L1, which is gradually reduced;

[0070] The second jet cavity 4052 is located at the position of the expansion concave ring 4053, and its ring diameter is set to L3. The change trend of its ring diameter is first expanded and then reduced. The first expanded part forms the first inner shoulder L2, and the reduced bending part is the second inner shoulder L4. The aperture of the first inner shoulder L2 is always larger than the aperture of the second inner shoulder L4, so as to form an inclined surface that can gradually increase the flow rate.

[0071] The ring diameter of the third jet cavity 4054 is set to L5, which is gradually expanding;

[0072] The ring diameter of the fourth jet cavity 4056 is set to L6, which is gradually enlarged;

[0073] Based on the above, the junction of the first jet cavity 4051 and the second jet cavity 4052 is the throat at the first location. The fluid increases its flow rate through the throat at the first location. When entering the second jet cavity 4052, as the inner cavity shape of the second jet cavity 4052 moves, the cavity shrinks, and the fluid also gradually shrinks and increases in speed until it reaches the second throat formed by the junction of the second jet cavity 4052 and the third jet cavity 4054. The fluid is accelerated again in the throat. At this time, the fluid moves in the tube in the manner that the flow rate increases where the cross-section is narrow, thereby achieving the effect of twice increasing speed in the cavities of the first jet cavity 4051, the second jet cavity 4052 and the third jet cavity 4054.

[0074] More specifically, and in combination with reference 10, an air chamber 413 is provided around the position of the inner valve chamber 4055 in the heat transfer inner tube 404, and the air chamber 413 has a temperature storage effect to prevent the liquid to be injected from losing heat too quickly at the outlet position.

[0075] See also Fig.11 The nozzle structure includes a plug body 406 and a nozzle 409. The plug body 406 is arranged along the axial direction of the inner valve chamber 4055, and one end of the plug body 406 is against the downstream outlet position of the third jet chamber 4054, and the other end is provided with an open liquid outlet channel 408. The annular side of the plug body 406 is provided with a liquid inlet 407 communicated with the liquid outlet channel 408. The nozzle 409 protrudes toward one side of the liquid outlet channel 408 and extends to the inside of the liquid outlet channel 408. A first spring 410 is provided between the nozzle 409 and the plug body 406. The outer annular surface of the nozzle 409 is tightly abutted against the cavity wall of the inner valve chamber 4055. At least one passage 411 communicating with the outside is provided inside the nozzle 409, and the outlets of multiple passages 411 merge to form an outlet channel 412;

[0076] The first spring 410 supports the plug body 406 , so that the end of the plug body 406 abuts against and closes the outlet of the third jet cavity 4054 .

[0077] Specifically, part of the annular surface of the plug body 406 does not contact the inner valve chamber 4055. The plastic sol to be injected flows through the liquid inlet 407 and pushes the plug body 406 to move through the injection pressure, and then enters the liquid outlet channel 408 through the liquid inlet 407. The plastic sol to be injected is ejected through the liquid outlet channel 408 and the passage 411. During this process, it is worth mentioning that the fourth jet cavity 4056 is set to a flared setting, and its ejection diameter is also a narrow throat setting. The time when the sol is ejected is the last acceleration. Combining the above two acceleration structures, the present application can realize the increase of the injection speed during the injection of the plastic sol. The high-speed filling increases the flow rate length and makes the flow smooth, reduces the overall flow resistance, and makes the material more evenly distributed in the entire mold cavity 301, thereby improving the injection quality and stabilizing the product size.

[0078] See also Fig.12 The fixed socket 5 and the movable mold core 4 are arranged opposite to each other. The plug of the fixed socket 5 is a retractable end that can be inserted into the movable mold core 4. After the injection molding is completed, a cavity for plugging in the toothbrush head is reserved at the end of the toothbrush handle. The specific structure of the fixed socket 5 includes a fixed column 501 arranged on the wall of the telescopic groove 101. An inner cavity 502 is opened inside the fixed column 501. A second spring 503 is installed in the cavity, and a movable plug 504 is also installed in the cavity. Under normal conditions, the movable plug 504 is supported by the second spring 503 to extend out of the cavity of the inner cavity 502 and extend to the outlet 4057 of the movable mold core 4.

[0079] When the movable mold core 4 is spraying glue, the movable plug 504 is pressed and retracted into the inner cavity 502 until the movable mold core 4 finishes spraying glue. The movable plug 504 is supported by the second spring 503 and inserted into the outer tube 403 to close the outlet of the fourth jet cavity 4056.

[0080] Based on the above structure, this application also provides the following steps for injection molding of the toothbrush handle:

[0081] Step 1: First, close the fixed mold frame 1 and the movable mold frame 2 to ensure that the parts of the two mold frames are correctly aligned to prepare for the injection of the sol;

[0082] Step 2: After the sol is injected into the injection barrel 401 through the external connection tube, it passes through the injection barrel 401, the middle barrel 402 and the outer barrel 403 in sequence. The sol is injected and filled into the mold cavity 301 under the pressure of the screw or plunger. In this step, the injection process needs to maintain high pressure all the time;

[0083] Step 3: After the sol fills the mold cavity 301, continue to pressurize to compensate for the volume reduction during the cooling and shrinkage of the sol, so as to ensure the product's accurate size and stable performance;

[0084] It is worth noting that during the injection process in step three, the injection molding machine needs to keep a certain amount of plastic in a molten state for continuous supply, a process called material storage;

[0085] Step 4: The sol is cooled and hardened in the mold cavity 301 to become the final molded product. During this process, the temperature of the chilled water is required to be less than 25 degrees and the temperature of the cooling water is required to be less than 32 degrees before entering the next step;

[0086] Step 5: After the sol is completely cooled and solidified, the fixed mold frame 1 is separated from the movable mold frame 2, and the movable assembly 105 drives the movable mold core 4 to retreat as a whole until it exits the fixed baffle 102. At this time, the molded toothbrush handle remains in the mold cavity 301, and the movable sub-mold 3 moves down to leave the toothbrush handle empty. Finally, the toothbrush handle is removed to complete the injection molding and removal.

[0087] The above is only a preferred embodiment of the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the principles of the present invention, and these improvements and modifications should also be considered as the protection scope of the present invention. The structures, devices and operating methods not specifically described and explained in the present invention shall be implemented according to the conventional means in the art unless otherwise specified and limited.

Claims

1. A toothbrush handle injection molding device, characterized in that: include: A fixed mold frame, the fixed mold frame is fixed to the injection molding frame mold, and at least one movable sub-mold is arranged on the fixed mold frame, the movable sub-mold is telescopically installed in the fixed mold frame, and a mold cavity for injection molding filling is opened on the top of the movable sub-mold; The movable mold frame is located on the opposite side of the fixed mold frame and moves closer or farther; The moving component is arranged on one side of the fixed mold frame, and moves forward or backward in the direction of the moving mold frame. A moving mold core is inserted and fixed on the moving component, and a flow path for the injection sol is arranged inside the moving mold core; When the fixed mold frame and the movable mold frame are close to each other, the movable mold core is located in the mold cavity and does not fit the cavity wall of the mold cavity, and the injection molding sol is injected into the cavity formed between the movable mold core and the mold cavity through the flow path, and a toothbrush handle is formed through injection molding and filling. When the fixed mold frame and the movable mold frame are separated from each other, the movable mold core withdraws from the mold cavity and moves away from the movable sub-mold, and the toothbrush handle after injection molding remains in the mold cavity; The movable mold core comprises an injection cylinder, a middle cylinder and an outer tube, the injection cylinder is fixed on the movable assembly, and the injection cylinder is combined with the outer tube through the middle cylinder; A heat transfer inner tube is arranged inside the outer tube, and a flow path is axially arranged inside the heat transfer inner tube. The plastic sol to be injected passes through the injection cylinder, the middle cylinder and the heat transfer inner tube in sequence, and flows out from the end of the heat transfer inner tube. Wherein, the material used for the heat transfer inner tube is any one of aluminum alloy, copper alloy or steel alloy; The flow path includes a first jet cavity disposed near the moving component, wherein the aperture of the first jet cavity gradually decreases as it moves away from the moving component; and A second jet cavity, the second jet cavity is combined with the end section of the first jet cavity, the aperture direction of the second jet cavity continues the aperture direction of the first jet cavity, and the overall trend is gradually reduced; The third jet cavity is combined with the end section of the second jet cavity, and the cross section of the third jet cavity is flared and gradually expands as it moves away from the moving component. An inner valve chamber, the inner valve chamber is located downstream of the third jet chamber and is provided with a nozzle structure therein; The fourth jet cavity is arranged at the outlet of the inner valve cavity, and its cross section is also in an expanded shape and gradually expands as it moves away from the moving component; An outlet, the outlet is arranged at a position of the port of the outer tube corresponding to the fourth jet cavity, and the plastic sol to be injected is discharged from the outlet; An expansion concave ring is also opened inwardly along the inner annular surface of the second jet cavity, and the ring diameter of the expansion concave ring is enlarged to accelerate the flow rate.

2. The toothbrush handle injection molding device according to claim 1, characterized in that: The fixed mold frame is provided with the same number of telescopic slots as the movable sub-mold, one side of the telescopic slot is provided with a fixed baffle, and the other side is provided with a fixed socket; A groove is provided on the fixed mold frame adjacent to the fixed baffle, and a slide plate is provided on the side of the fixed mold frame corresponding to the groove. The moving component slides on the slide plate to drive the moving mold core to reciprocate through the fixed baffle to complete injection molding or demoulding.

3. The toothbrush handle injection molding device according to claim 1, characterized in that: The bottom surface of the movable mold frame is provided with a corresponding mold cavity at a position corresponding to the movable auxiliary mold, so that the toothbrush handle forms a complete columnar shape.

4. The toothbrush handle injection molding device according to claim 1, characterized in that: The nozzle structure comprises: A plug body, wherein the plug body is arranged along the axial direction of the inner valve chamber, and one end of the plug body bears against the downstream outlet position of the third jet cavity, and the other end is provided with an open liquid outlet channel, and the ring side of the plug body is provided with a liquid inlet communicated with the liquid outlet channel; A nozzle, the nozzle protrudes toward one side of the liquid outlet channel and extends into the liquid outlet channel, a first spring is arranged between the nozzle and the plug body, an outer annular surface of the nozzle is in close contact with the cavity wall of the inner valve chamber, at least one passage is opened inside the nozzle and communicates with the outside, and outlets of a plurality of the passages converge to form an outlet channel; The first spring supports the plug body so that the end of the plug body abuts against and closes the outlet of the third jet cavity.

5. The toothbrush handle injection molding device according to claim 4, characterized in that: An air chamber is provided around the position of the inner valve chamber in the heat transfer inner tube to prevent the liquid to be injected from losing heat too quickly at the outlet position.

6. The toothbrush handle injection molding device according to claim 4, characterized in that: The annular side surface of the heat transfer inner tube facing the middle tube is concave, and this end does not contact the inner annular surface of the outer tube, forming a notch connected to the middle tube. The port of the middle tube adapts to the notch and extends to form a connecting plug, which is detachably coupled to the inside of the notch, so that the middle tube and the outer tube are connected through this structure.

7. A method for injection molding a toothbrush handle, used for operating the toothbrush handle injection molding device according to any one of claims 1 to 6, characterized in that: Step 1: First, close the fixed mold frame and the movable mold frame, and ensure that the parts of the two mold frames are correctly aligned to prepare for the injection of the sol; Step 2: After the sol is injected into the injection barrel through the external connecting tube, it passes through the injection barrel, the middle barrel and the outer barrel in sequence. The sol is injected and filled into the mold cavity under the pressure of the screw or plunger. In this step, the injection process needs to maintain high pressure all the time; Step 3: After the sol fills the mold cavity, continue to pressurize to compensate for the volume reduction during the cooling and shrinkage of the sol, ensuring the product's accurate size and stable performance; Step 4: The sol is cooled and hardened in the mold cavity to become the final molded product. During this process, the chilled water temperature is required to be less than degrees and the cooling water temperature is required to be less than degrees before entering the next step; Step 5: After the sol is completely cooled and solidified, the fixed mold frame is separated from the movable mold frame, and the movable assembly drives the movable mold core to retreat as a whole until it exits the fixed baffle. At this time, the molded toothbrush handle remains in the mold cavity, and the movable sub-mold is moved down to make the toothbrush handle empty. Finally, the toothbrush handle is removed to complete the injection molding and removal.

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